Join the 200th Anniversary Celebration

Original Article

The Isolation of Antibiotic-Resistant Salmonella from Retail Ground Meats

David G. White, Ph.D., Shaohua Zhao, D.V.M., Ph.D., Robert Sudler, M.S., Sherry Ayers, Sharon Friedman, B.A., Sheng Chen, D.V.M., Patrick F. McDermott, Ph.D., Shawn McDermott, B.S., David D. Wagner, Ph.D., and Jianghong Meng, D.V.M., Ph.D.

N Engl J Med 2001; 345:1147-1154October 18, 2001

Abstract

Background

Salmonella is a leading cause of food-borne illness. The emergence of antimicrobial-resistant salmonella is associated with the use of antibiotics in animals raised for food; resistant bacteria can be transmitted to humans through foods, particularly those of animal origin. We identified and characterized strains of salmonella isolated from ground meats purchased in the Washington, D.C., area.

Methods

Salmonella was isolated from samples of ground chicken, beef, turkey, and pork purchased at three supermarkets. The isolates were characterized by serotyping, antimicrobial-susceptibility testing, phage typing, and pulsed-field gel electrophoresis. The polymerase chain reaction and DNA sequencing were used to identify resistance integrons and extended spectrum β-lactamase genes.

Results

Of 200 meat samples, 41 (20 percent) contained salmonella, with a total of 13 serotypes. Eighty-four percent of the isolates were resistant to at least one antibiotic, and 53 percent were resistant to at least three antibiotics. Sixteen percent of the isolates were resistant to ceftriaxone, the drug of choice for treating salmonellosis in children. Bacteriophage typing identified four isolates of Salmonella enterica serotype typhimurium definitive type 104 (DT104), one of DT104b, and two of DT208. Five isolates of S. enterica serotype agona had resistance to 9 antibiotics, and the two isolates of serotype typhimurium DT208 were resistant to 12 antibiotics. Electrophoretic patterns of DNA that were indistinguishable from one another were repeatedly found in isolates from different meat samples and different stores. Eighteen isolates, representing four serotypes, had integrons with genes conferring resistance to aminoglycosides, sulfonamides, trimethoprim, and β-lactams.

Conclusions

Resistant strains of salmonella are common in retail ground meats. These findings provide support for the adoption of guidelines for the prudent use of antibiotics in food animals and for a reduction in the number of pathogens present on farms and in slaughterhouses. National surveillance for antimicrobial-resistant salmonella should be extended to include retail meats.

Media in This Article

Figure 1Dendrogram of Patterns Obtained by Pulsed-Field Gel Electrophoresis (PFGE) of Isolates of Salmonella enterica Recovered from Ground Meat from Three Supermarkets and Their Relation to the Serotype and Type and Brand of Meat.
Table 1Characteristics of Salmonella Isolated from Ground Meat from Three Supermarkets in the Greater Washington, D.C., Area, June to August 1998.
Article

Foodborne diseases caused by non-typhoid salmonella represent an important public health problem worldwide. Nearly 1.4 million cases of salmonellosis occur each year in the United States.1 Most salmonella infections in humans result from the ingestion of contaminated poultry, beef, pork, eggs, and milk.2 Intestinal salmonellosis typically resolves in five to seven days and does not require treatment with antibiotics. However, bacteremia occurs in 3 to 10 percent of reported, culture-confirmed cases and is particularly common among patients at the extremes of age and those who are immunocompromised. When infection spreads beyond the intestinal tract, appropriate antimicrobial therapy (e.g., ciprofloxacin in adults and ceftriaxone in children) can be lifesaving.3,4

The use of antimicrobial agents in any environment creates selection pressures that favor the survival of antibiotic-resistant pathogens. According to the infectious-disease report that was released by the World Health Organization in 2000, such organisms have become increasingly prevalent worldwide.5 The routine practice of giving antimicrobial agents to domestic livestock as a means of preventing and treating diseases, as well as promoting growth, is an important factor in the emergence of antibiotic-resistant bacteria that are subsequently transferred to humans through the food chain.6,7 Most infections with antimicrobial-resistant salmonella are acquired by eating contaminated foods of animal origin.8,9

There is now widespread dissemination of multidrug-resistant Salmonella enterica serotype typhimurium, particularly definitive type 104 (DT104).4 Recent studies have documented a ceftriaxone-resistant salmonella infection in a child that was acquired through exposure to cattle9 and the emergence of ceftriaxone-resistant salmonella infections in humans in the United States.10 The sources of salmonella infections are often unknown, but they most likely originate in contaminated food of animal origin. We isolated and characterized salmonella strains from ground meats obtained in retail markets in the greater Washington, D.C., area and determined the antimicrobial-resistance phenotypes of the isolates.

Methods

Collection of Retail Meat Samples and Isolation of Salmonella

Two hundred samples of ground meat (51 samples of chicken, 50 of beef, 50 of turkey, and 49 of pork) were purchased at three retail stores representing three supermarket chains in the greater Washington, D.C., area between June and September 1998: 98 at store 1, 54 at store 2, and 48 at store 3. All poultry and pork samples were processed and packaged at one of four poultry-processing plants and one pork-processing plant, respectively, whereas all samples of beef were ground in the store and then packaged. Salmonella was isolated from ground meats with the use of methods described in the Bacteriological Analytical Manual of the Food and Drug Administration.11

Serotyping, Phage Typing, and Pulsed-Field Gel Electrophoresis

Salmonella serotypes were determined with the use of commercial antiserum (Difco, Detroit), according to the manufacturer's instructions. Eight isolates of S. enterica typhimurium that were resistant to at least five antibiotics were selected for phage-typing analysis, conducted at the National Veterinary Services Laboratories of the Department of Agriculture in Ames, Iowa.

Pulsed-field gel electrophoresis was used for separation of DNA fragments resulting from digestion by restriction enzymes. The resulting genomic-DNA profiles, or “fingerprints,” were interpreted according to established guidelines.12-14 To be considered part of a cluster, the DNA patterns could not differ from each other by more than 30 percent. Patterns that were the same size and had the same numbers of bands were considered to be the same strain (e.g., type A). Patterns that differed by fewer than four bands were considered to represent subtypes within the main group (e.g., A1, A2, and A3). Patterns that differed from the main pattern by four or more bands were considered to represent different strains (e.g., type A, B, or C).

Testing for Antimicrobial Susceptibility

Salmonella isolates were assayed for susceptibility to 17 antibiotics used by the National Antimicrobial Resistance Monitoring System.15 Minimal inhibitory concentrations were determined by the broth-microdilution method with use of the Sensititre system (Trek Diagnostic Systems, Westlake, Ohio) and recommended quality-control organisms. The results were interpreted in accordance with the standards of the National Committee for Clinical Laboratory Standards, when available.16,17

Amplification

Since resistance to sulfa antimicrobial agents is characteristic of class 1 integrons, sulfamethoxazole-resistant salmonella isolates were screened for the presence of such integrons. In addition, isolates that demonstrated resistance to the extended-spectrum cephalosporins ceftiofur and ceftriaxone were examined for the presence of the extended-spectrum β-lactamase gene bla CMY-2. Class 1 integrons were amplified with the use of the polymerase chain reaction (PCR) and primers 5'-CS (5'GGCATCCAAGCACAAGC3') and 3'-CS (5'AAGCAGACTTGACTGAT3').18 The blaCMY-2 gene was amplified with the use of primers cmy-F (5'GACAGCCTCTTTCTCCACA3') and cmy-R (5'TGGAACGAAGGCTACGTA3').19 Amplifications were carried out as described previously.18,19

Nucleotide-Sequencing Analysis

PCR products of integrons and the bla CMY genes were purified with a kit (Boehringer Mannheim, Indianapolis). The DNA sequences were determined at the University of Maryland, College Park, and compared with use of the Basic Local Alignment Search Tool (National Center for Biotechnology Information, Bethesda, Md.).20

Results

Serotypes

Salmonella isolates were recovered from 41 of 200 samples of ground meat (20 percent); 4 samples each yielded two strains of salmonella. Salmonella was isolated more frequently from poultry (35 percent of chicken samples and 24 percent of turkey samples) than from pork (16 percent of samples) or beef (6 percent of samples). Thirteen serotypes were identified among the 45 salmonella isolates (Table 1Table 1Characteristics of Salmonella Isolated from Ground Meat from Three Supermarkets in the Greater Washington, D.C., Area, June to August 1998.); S. enterica serotype Istanbul (28 percent) and S. enterica serotype agona (22 percent) were isolated most frequently. All 13 isolates of S. enterica serotype Istanbul were recovered from chicken purchased from two stores on various sampling dates. In contrast, S. enterica serotype agona was isolated from all four types of ground meat, with turkey being the most frequent source (7 of 10 samples). Four of the eight isolates of S. enterica serotype typhimurium were from chicken, and four were from pork.

On three occasions, two different serotypes were isolated from the same sample (Table 1). For example, S. enterica serotype chomedey was also isolated from one of the three pork samples from which S. enterica serotype typhimurium DT104 was recovered. Serotypes typhimurium DT104b and Derby were both identified in the same pork sample from store 3, and serotypes agona and Kentucky were isolated from the same chicken sample from store 2.

Antimicrobial Resistance

Eighty-four percent of isolates (38 of 45) displayed resistance to at least one antibiotic, and 53 percent (24 of 45) displayed resistance to at least three antibiotics. Among multidrug-resistant isolates, resistance to streptomycin, sulfamethoxazole, and tetracycline was most often observed (Table 1). The 10 isolates of S. enterica serotype agona displayed three resistance phenotypes, with 5 isolates exhibiting resistance to nine antibiotics (including ceftriaxone). The 13 isolates of S. enterica serotype Istanbul were all resistant to streptomycin and tetracycline, and 6 of the 13 were also resistant to sulfamethoxazole. Seven of the eight isolates of S. enterica serotype typhimurium displayed resistance to at least five antibiotics, including ampicillin, chloramphenicol, streptomycin, sulfamethoxazole, and tetracycline — the typical resistance profile of serotype typhimurium DT104. Bacteriophage typing identified four of these isolates as DT104, one as DT104b, and two as DT208. The two DT208 isolates, which were recovered from samples of ground chicken, showed similar patterns on pulsed-field gel electrophoresis, and both displayed resistance to the same 12 antimicrobial agents, including ceftriaxone.

All strains of salmonella were susceptible to amikacin, apramycin, ciprofloxacin, and nalidixic acid (Table 2Table 2Resistance Phenotypes of Salmonella Isolated from Ground Meat.). The isolates were most likely to be resistant to tetracycline (80 percent of isolates), streptomycin (73 percent), sulfamethoxazole (60 percent), and to a lesser extent, ampicillin (27 percent). In addition, 16 percent of the isolates displayed resistance to florfenicol, chloramphenicol, amoxicillin–clavulanic acid, cephalothin, ceftiofur, and ceftriaxone (Table 2). Isolates recovered from ground turkey and beef were susceptible to chloramphenicol, florfenicol, and kanamycin, whereas the two gentamicin-resistant isolates were both recovered from ground chicken. Ceftiofur- and ceftriaxone-resistant strains were isolated from ground turkey, chicken, and beef but not from ground pork.

Antibiotic-Resistance Integrons and bla CMY Genes

Eighteen of 27 sulfamethoxazole-resistant isolates encompassing four serotypes (agona, chomedey, djugu, and typhimurium) possessed class 1 integrons (Table 1). The sizes of these integrons ranged from 0.75 to 2.7 kb. The five isolates of S. enterica serotype agona that were resistant to nine antibiotics had an integron of 1.2 kb, whereas the three isolates that were resistant to streptomycin, sulfamethoxazole, and tetracycline had an integron of 1.0 kb. The 2.0-kb integrons identified in S. enterica serotypes chomedey and djugu contained two genes: aminoglycoside adenyltransferase A2 (aadA2), which confers resistance to streptomycin and spectinomycin, and dihydrofolate reductase XII (dfrXII ), which confers resistance to trimethoprim (Table 1). It is interesting to note that these isolates were phenotypically susceptible to streptomycin, which suggests that the aadA2 gene is not being expressed. The 1.0-kb and 1.2-kb integrons characterized in isolates of S. enterica serotype agona contained the aadA1 gene, which confers resistance to streptomycin.

All eight isolates of S. enterica serotype typhimurium possessed integrons. Four DT104 isolates and one DT104b isolate possessed a 1.0-kb integron containing aadA2 and a 1.2-kb integron containing the β-lactamase gene bla PSE-1, which confers resistance to ampicillin. The largest integrons (2.7 kb) were identified in the two isolates of S. enterica serotype typhimurium DT208, which were resistant to 12 of the 17 antimicrobial agents tested. DNA-sequence analysis identified the aadA gene and three open reading frames that have yet to be characterized. In addition, the 0.75-kb integron identified in the remaining S. enterica serotype typhimurium isolate contained the dfrXIII gene, which confers resistance to trimethoprim. The five isolates of S. enterica serotype agona and the two isolates of S. enterica serotype typhimurium DT208 that were resistant to ceftiofur and ceftriaxone had a plasmid-mediated bla CMY-2 β-lactamase gene (Table 1).

Results of Pulsed-Field Gel Electrophoresis

Of the 45 isolates, 36 were differentiated with the use of pulsed-field gel electrophoresis. One isolate of S. enterica serotype agona was untypable. Overall, eight pulsed-field gel electrophoresis strain types (A through H) and six clusters were identified (Figure 1Figure 1Dendrogram of Patterns Obtained by Pulsed-Field Gel Electrophoresis (PFGE) of Isolates of Salmonella enterica Recovered from Ground Meat from Three Supermarkets and Their Relation to the Serotype and Type and Brand of Meat.). The nine typable isolates of S. enterica serotype agona were from three strains (types A, B, and C) and had five electrophoretic patterns. The five type A isolates of S. enterica serotype agona were resistant to the same nine antibiotics, whereas the three type C isolates were resistant to only three. These three isolates had identical electrophoretic patterns and were recovered from one sample of ground pork and two samples of ground turkey purchased on different sampling dates from different grocery stores. One isolate of S. enterica serotype agona was susceptible to all 17 antibiotics and was the only strain categorized as type B.

The 13 isolates of S. enterica serotype Istanbul were recovered from two brands of ground chicken and formed a single strain (type D) with three closely related patterns on pulsed-field gel electrophoresis (Figure 1). Ten of these isolates had the same pattern (type D1). The 13 isolates were recovered from two stores on five sampling dates. Four isolates of S. enterica serotype Reading were isolated from turkey from two stores on two dates and had similar electrophoretic patterns.

The four isolates of S. enterica serotype typhimurium DT104 had identical patterns (all were type F1) that differed from the pattern of serotype typhimurium DT104b (type F2) by a single band, indicating close similarity. The two isolates of serotype typhimurium DT208 were from samples of ground chicken obtained from the same store on the same date and had closely related patterns (G1 and G2) and identical resistance phenotypes. The two isolates of S. enterica serotype orion were recovered from chicken and turkey from the same store and had identical patterns on pulsed-field gel electrophoresis (type H).

Discussion

In this study, 20 percent of ground meat samples from supermarkets in the greater Washington, D.C., area were contaminated with 13 serotypes of salmonella. Of particular importance is the isolation of ceftriaxone-resistant salmonella as well as multidrug-resistant S. enterica serotype typhimurium definitive types DT208 and DT104. The latter can cause severe illness and is usually resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline.21 The number of cases of infection with serotype typhimurium DT104 has increased in many countries.22-25 A retrospective study of infections with S. enterica serotype typhimurium by the Centers for Disease Control and Prevention revealed that the percentage of isolates that were resistant to ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline increased from 0.6 percent during the period from 1979 to 1980 to 34 percent in 1996.4 Serotype typhimurium DT104 has been identified in numerous foods, including beef, pork, poultry, and unpasteurized dairy products, and its presence is thought to be due to the widespread clonal dissemination of multidrug-resistant isolates.4,26,27 Foodborne transmission of this serotype has been well documented, and several outbreaks have involved the consumption of contaminated meat and dairy products or contact with cattle.22,28-31 The isolation of S. enterica serotype typhimurium DT208 from ground meats sold in supermarkets is also cause for concern, given the extensive pattern of resistance of this organism.

Our finding of identical isolates of S. enterica serotype Istanbul from two brands of ground chicken samples from two grocery stores over a seven-week sampling period demonstrates the potential for the contamination of food during handling and processing. However, the contamination of retail meats with resistant salmonella mainly reflects carriage of the organism by livestock; intervention strategies should therefore focus principally on reducing the number of pathogens present on farms and in slaughterhouses.

Although S. enterica serotype agona is less commonly associated with disease in humans than is S. enterica serotype typhimurium, it has been the cause of several foodborne outbreaks in recent years.32-34 Our study identified five such isolates that were resistant to nine antibiotics, including ceftriaxone and ceftiofur. These isolates were recovered from different types of ground meat (turkey and beef) from the same store over a two-week period. These meats were ground at three different facilities, suggesting that the source of this serotype was the meat itself.

Ceftiofur is the only expanded-spectrum cephalosporin approved for use in food animals in the United States. Ceftriaxone is commonly used to treat children with salmonella infections, particularly invasive infections, because of its favorable pharmacokinetic properties and the low prevalence of resistance.10 Previous reports have described salmonella strains with the same plasmid-mediated β-lactamase resistance gene (bla CMY-2), which confers resistance to both ceftiofur and ceftriaxone, that we found in our salmonella isolates.9,10,19 Thus, it has been argued that the use of ceftiofur in livestock accelerated the rate of the development of resistance to ceftriaxone in salmonella.10,19 Though our data could not be used to attribute the presence of ceftriaxone-resistant phenotypes to the use of ceftiofur in livestock, it does support previous findings that foods of animal origin are potential sources of ceftriaxone-resistant salmonella infections in humans.9 The dissemination of salmonella that is resistant to multiple drugs, including cephalosporins, through food has important public health implications.

The ability of bacteria to acquire antibiotic-resistance genes and subsequently spread them to many different bacterial species is well known.35 Integrons, one such mobile DNA element, have been associated with the transfer of resistance and often contain one or more linked antimicrobial-resistance genes.36 Integrons are therefore particularly important, since a strong selection pressure exerted by antibiotics can potentially result in the mobilization and dissemination of linked multidrug-resistance phenotypes. The two integrons we identified in the isolates of S. enterica serotypes typhimurium DT104 and DT104b were identical to those characterized in strains of typhimurium DT104 found in many other outbreaks.18,21

We also identified integrons conferring resistance to streptomycin and trimethoprim in other serotypes of salmonella, suggesting that integrons play an important part in the transfer of resistance among these serotypes. This conclusion is supported by recent reports describing integrons in serotypes other than typhimurium.37,38 However, integrons and their associated gene cassettes did not always account for the entire observed resistance phenotype, indicating that other mechanisms were also involved.

Our findings demonstrate that multidrug-resistant strains of salmonella, including ceftriaxone-resistant isolates, are frequently present in retail ground meats in the greater Washington, D.C., area. The presence of these strains, particularly typhimurium DT104 and DT208, is of concern, considering their extremely resistant phenotypes and the association of DT104 with numerous foodborne outbreaks. Although we have no corresponding culture data from humans, our data provide support for the theory that the food supply is a major source of antimicrobial-resistant salmonella. The high prevalence of multidrug-resistant salmonella in retail ground meats reflects a reservoir of resistance in animals that can be transmitted to humans.

Efforts are needed to reduce the prevalence of resistant salmonella in food, including the adoption of guidelines for the prudent use of antimicrobial agents in animals used for food, the passage of new food-safety regulations, and a reduction in the number of pathogens present on farms and in slaughterhouses. In addition, a national surveillance program focusing on the identification and molecular subtyping of zoonotic foodborne bacterial pathogens that are present in retail foods should be established. Such measures will supplement ongoing surveillance programs such as the National Antimicrobial Resistance Monitoring System and the Foodborne Diseases Active Surveillance Network (FoodNet) and consumer-education efforts to protect public health.

Supported in part by a grant from the Maryland Agricultural Experimental Station.

We are indebted to Robert Walker, Ph.D., from the Division of Animal and Food Microbiology, Center for Veterinary Medicine, Food and Drug Administration, for his assistance and comments in the preparation of this article.

Source Information

From the Division of Animal and Food Microbiology Office of Research, Center for Veterinary Medicine, Food and Drug Administration, Laurel, Md. (D.G.W., S.Z., S.A., S.F., P.F.M., S.M., D.D.W.); and the Department of Nutrition and Food Science, University of Maryland, College Park (R.S., S.C., J.M.).

Address reprint requests to Dr. Meng at the Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, or at .

References

References

  1. 1

    Mead PS, Slutsker L, Dietz V, et al. Food-related illness and death in the United States. Emerg Infect Dis 1999;5:607-625
    CrossRef | Web of Science | Medline

  2. 2

    Gomez TM, Motarjemi Y, Miyagawa S, Kaferstein FK, Stohr K. Foodborne salmonellosis. World Health Stat Q 1997;50:81-89
    Medline

  3. 3

    Hohmann EL. Nontyphoidal salmonellosis. Clin Infect Dis 2001;32:263-269
    CrossRef | Web of Science | Medline

  4. 4

    Glynn MK, Bopp C, Dewitt W, Dabney P, Mokhtar M, Angulo FJ. Emergence of multidrug-resistant Salmonella enterica serotype typhimurium DT104 infections in the United States. N Engl J Med 1998;338:1333-1338
    Full Text | Web of Science | Medline

  5. 5

    Overcoming antimicrobial resistance. Geneva: World Health Organization, 2000. (Accessed September 27, 2001, at http://www.who.int/infectious-disease-report/2000/index.html.)

  6. 6

    Tollefson L, Altekruse SF, Potter ME. Therapeutic antibiotics in animal feeds and antibiotic resistance. Rev Sci Tech 1997;16:709-715
    Web of Science | Medline

  7. 7

    Witte W. Medical consequences of antibiotic use in agriculture. Science 1998;279:996-997
    CrossRef | Web of Science | Medline

  8. 8

    Angulo FJ, Johnson KR, Tauxe RV, Cohen ML. Origins and consequences of antimicrobial-resistant nontyphoidal Salmonella: implications for the use of fluoroquinolones in food animals. Microb Drug Resist 2000;6:77-83
    CrossRef | Web of Science | Medline

  9. 9

    Fey PD, Safranek TJ, Rupp ME, et al. Ceftriaxone-resistant Salmonella infection acquired by a child from cattle. N Engl J Med 2000;342:1242-1249
    Full Text | Web of Science | Medline

  10. 10

    Dunne EF, Fey PD, Kludt P, et al. Emergence of domestically acquired ceftriaxone-resistant Salmonella infections associated with AmpC beta-lactamase. JAMA 2000;284:3151-3156
    CrossRef | Web of Science | Medline

  11. 11

    Food and Drug Administration. Bacteriological analytical manual. 8th ed. Gaithersburg, Md.: AOAC International, 1998.

  12. 12

    Standard molecular subtyping of foodborne bacterial pathogens by pulsed-field gel electrophoresis: CDC training manual. Atlanta: Centers for Disease Control and Prevention, 1998.

  13. 13

    Tenover FC, Arbeit RD, Goering RV, et al. Interpreting chromosomal DNA restriction patterns produced by pulsed-field gel electrophoresis: criteria for bacterial strain typing. J Clin Microbiol 1995;33:2233-2239
    Web of Science | Medline

  14. 14

    Bannerman TL, Hancock GA, Tenover FC, Miller JM. Pulsed-field gel electrophoresis as a replacement for bacteriophage typing of Staphylococcus aureus. J Clin Microbiol 1995;33:551-555
    Web of Science | Medline

  15. 15

    Tollefson L, Angulo FJ, Fedorka-Cray PJ. National surveillance for antibiotic resistance in zoonotic enteric pathogens. Vet Clin North Am Food Anim Pract 1998;14:141-150
    Web of Science | Medline

  16. 16

    Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; approved standard. Wayne, Pa.: National Committee for Clinical Laboratory Standards, 2000. (NCCLS document M7-A5.)

  17. 17

    Performance standards for antimicrobial disk and dilution susceptibility tests for bacteria isolated from animals; approved standard. Wayne, Pa.: National Committee for Clinical Laboratory Standards, 1999. (NCCLS document M31-A.)

  18. 18

    Sandvang D, Aarestrup FM, Jensen LB. Characterisation of integrons and antibiotic resistance genes in Danish multiresistant Salmonella enterica Typhimurium DT104. FEMS Microbiol Lett 1998;160:37-41
    CrossRef | Web of Science | Medline

  19. 19

    Winokur PL, Brueggemann A, DeSalvo DL, et al. Animal and human multidrug-resistant, cephalosporin-resistant Salmonella isolates expressing a plasmid-mediated CMY-2 AmpC beta-lactamase. Antimicrob Agents Chemother 2000;44:2777-2783
    CrossRef | Web of Science | Medline

  20. 20

    Altschul SF, Madden TL, Schaffer AA, et al. Gapped BLAST and PSI-BLAST: a new generation of protein database search programs. Nucleic Acids Res 1997;25:3389-3402
    CrossRef | Web of Science | Medline

  21. 21

    Ridley A, Threlfall EJ. Molecular epidemiology of antibiotic resistance genes in multiresistant epidemic Salmonella typhimurium DT104. Microb Drug Resist 1998;4:113-118
    CrossRef | Web of Science | Medline

  22. 22

    Calvert N, Stewart WC, Reilly WJ. Salmonella typhimurium DT104 infection in people and animals in Scotland: a collaborative epidemiological study 1993-96. Vet Rec 1998;143:351-354
    CrossRef | Web of Science | Medline

  23. 23

    Salmonella typhimurium DT104, Canada, 1997-1998. Wkly Epidemiol Rec 1999;74:345-347
    Medline

  24. 24

    Izumiya H, Tamura K, Terajima J, Watanabe H. Salmonella enterica serovar. Typhimurium phage type DT104 and other multi-drug resistant strains in Japan. Jpn J Infect Dis 1999;52:133-133
    Web of Science | Medline

  25. 25

    Markogiannakis A, Tassios PT, Lambiri M, et al. Multiple clones within multidrug-resistant Salmonella enterica serotype Typhimurium phage type DT104. J Clin Microbiol 2000;38:1269-1271
    Web of Science | Medline

  26. 26

    Baggesen DL, Sandvang D, Aarestrup FM. Characterization of Salmonella enterica serovar typhimurium DT104 isolated from Denmark and comparison with isolates from Europe and the United States. J Clin Microbiol 2000;38:1581-1586
    Web of Science | Medline

  27. 27

    Davis MA, Hancock DD, Besser TE, et al. Changes in antimicrobial resistance among Salmonella enterica Serovar typhimurium isolates from humans and cattle in the Northwestern United States, 1982-1997. Emerg Infect Dis 1999;5:802-806
    CrossRef | Web of Science | Medline

  28. 28

    Davies A, O'Neill P, Towers L, Cooke M. An outbreak of Salmonella typhimurium DT104 food poisoning associated with eating beef. Commun Dis Rep CDR Rev 1996;6:R159-R162
    Medline

  29. 29

    Grein T, O'Flanagan D, McCarthy T, Bauer D. An outbreak of multidrug-resistant Salmonella typhimurium food poisoning at a wedding reception. Ir Med J 1999;92:238-241
    Medline

  30. 30

    Villar RG, Macek MD, Simons S, et al. Investigation of multidrug-resistant Salmonella serotype typhimurium DT104 infections linked to raw-milk cheese in Washington State. JAMA 1999;281:1811-1816
    CrossRef | Web of Science | Medline

  31. 31

    Cody SH, Abbott SL, Marfin AA, et al. Two outbreaks of multidrug-resistant Salmonella serotype typhimurium DT104 infections linked to raw-milk cheese in Northern California. JAMA 1999;281:1805-1810
    CrossRef | Web of Science | Medline

  32. 32

    Synnott MB, Brindley M, Gray J, Dawson JK. An outbreak of Salmonella agona infection associated with precooked turkey meat. Commun Dis Public Health 1998;1:176-179
    Medline

  33. 33

    Taylor JP, Barnett BJ, del Rosario L, Williams K, Barth SS. Prospective investigation of cryptic outbreaks of Salmonella agona salmonellosis. J Clin Microbiol 1998;36:2861-2864
    Web of Science | Medline

  34. 34

    Multistate outbreak of Salmonella serotype Agona infections linked to toasted oats cereal -- United States, April-May, 1998. MMWR Morb Mortal Wkly Rep 1998;47:462-464
    Medline

  35. 35

    Hall RM. Mobile gene cassettes and integrons: moving antibiotic resistance genes in gram-negative bacteria. Ciba Found Symp 1997;207:192-202
    Medline

  36. 36

    Hall RM, Stokes HW. Integrons: novel DNA elements which capture genes by site-specific recombination. Genetica 1993;90:115-132
    CrossRef | Web of Science | Medline

  37. 37

    Cloeckaert A, Sidi Boumedine K, Flaujac G, Imberechts H, D'Hooghe I, Chaslus-Dancla E. Occurrence of a Salmonella enterica serovar typhimurium DT104-like antibiotic resistance gene cluster including the floR gene in S. enterica serovar agona. Antimicrob Agents Chemother 2000;44:1359-1361
    CrossRef | Web of Science | Medline

  38. 38

    Guerra B, Soto S, Cal S, Mendoza MC. Antimicrobial resistance and spread of class 1 integrons among Salmonella serotypes. Antimicrob Agents Chemother 2000;44:2166-2169
    CrossRef | Web of Science | Medline

Citing Articles (108)

Citing Articles

  1. 1

    AHMED A. TAYEL, WAEL F. EL-TRAS. (2012) PLANT EXTRACTS AS POTENT BIOPRESERVATIVES FOR SALMONELLA TYPHIMURIUM CONTROL AND QUALITY ENHANCEMENT IN GROUND BEEF. Journal of Food Safetyno-no
    CrossRef

  2. 2

    A.S. Kakatkar, L.S. Pansare, R.K. Gautam, R. Shashidhar, M. Karani, J.R. Bandekar. (2011) Molecular characterization of antibiotic resistant Salmonella isolates from Indian foods. Food Research International 44:10, 3272-3275
    CrossRef

  3. 3

    John Thomas, Sara Linton, Linda Corum, Will Slone, Tyler Okel, Steven L Percival. (2011) The affect of pH and bacterial phenotypic state on antibiotic efficacy. International Wound Journalno-no
    CrossRef

  4. 4

    Kwai Lin Thong, Shabnam Modarressi. (2011) Antimicrobial resistant genes associated with Salmonella from retail meats and street foods. Food Research International 44:9, 2641-2646
    CrossRef

  5. 5

    Hecheng Meng, Zhigang Zhang, Miaorui Chen, Yongyu Su, Lin Li, Shin-ichi Miyoshi, He Yan, Lei Shi. (2011) Characterization and horizontal transfer of class 1 integrons in Salmonella strains isolated from food products of animal origin. International Journal of Food Microbiology 149:3, 274-277
    CrossRef

  6. 6

    Xinlong He, Juhee Ahn. (2011) Survival and virulence properties of multiple antibiotic-resistant Salmonella Typhimurium under simulated gastrointestinal conditions. International Journal of Food Science & Technology 46:10, 2164-2172
    CrossRef

  7. 7

    F. LEWIS, M. J. SANCHEZ-VAZQUEZ, P. R. TORGERSON. (2011) Association between covariates and disease occurrence in the presence of diagnostic error. Epidemiology and Infection1-10
    CrossRef

  8. 8

    O. Barraud, M.-C. Ploy. (2011) Actualités sur les intégrons de résistance aux antibiotiques : mise au point. Journal des Anti-infectieux 13:3, 133-144
    CrossRef

  9. 9

    Shweta Singh, Rajesh Kumar Agarwal, Suresh C. Tiwari, Himanshu Singh. (2011) Antibiotic resistance pattern among the Salmonella isolated from human, animal and meat in India. Tropical Animal Health and Production
    CrossRef

  10. 10

    N. Taşkale, M. Akçelik. (2011) Use of RAPD-PCR, plasmid profiling, class 1 integron analysis, and antimicrobial resistance for molecular characterisation of <i>Salmonella</i> strains isolated from Turkey. Acta Alimentaria 1:-1, 1-11
    CrossRef

  11. 11

    Bwalya Lungu, Corliss A. O'Bryan, Arunachalam Muthaiyan, Sara R. Milillo, Michael G. Johnson, Philip G. Crandall, Steven C. Ricke. (2011) Listeria monocytogenes : Antibiotic Resistance in Food Production. Foodborne Pathogens and Disease 8:5, 569-578
    CrossRef

  12. 12

    Yeliz Yildirim, Zafer Gonulalan, Sebnem Pamuk, Nurhan Ertas. (2011) Incidence and antibiotic resistance of Salmonella spp. on raw chicken carcasses. Food Research International 44:3, 725-728
    CrossRef

  13. 13

    James C. Carlson, Alan B. Franklin, Doreene R. Hyatt, Susan E. Pettit, George M. Linz. (2011) The role of starlings in the spread of Salmonella within concentrated animal feeding operations. Journal of Applied Ecology 48:2, 479-486
    CrossRef

  14. 14

    Frederick Adzitey, Gulam Rusul, Nurul Huda. (2011) Prevalence and antibiotic resistance of Salmonella serovars in ducks, duck rearing and processing environments in Penang, Malaysia. Food Research International
    CrossRef

  15. 15

    Dixie F. Mollenkopf, Katie E. Kleinhenz, Julie A. Funk, Wondwossen A. Gebreyes, Thomas E. Wittum. (2011) Salmonella enterica and Escherichia coli Harboring bla CMY in Retail Beef and Pork Products. Foodborne Pathogens and Disease 8:2, 333-336
    CrossRef

  16. 16

    James C Carlson, Richard M Engeman, Doreene R Hyatt, Rickey L Gilliland, Thomas J DeLiberto, Larry Clark, Michael J Bodenchuk, George M Linz. (2011) Efficacy of European starling control to reduce Salmonella enterica contamination in a concentrated animal feeding operation in the Texas panhandle. BMC Veterinary Research 7:1, 9
    CrossRef

  17. 17

    C. C. Adley, C. Dillon. 2011. Listeriosis, salmonellosis and verocytotoxigenic Escherichia coli: significance and contamination in processed meats. , 72-108.
    CrossRef

  18. 18

    Baowei Yang, Meili Xi, Shenghui Cui, Xiuli Zhang, Jinling Shen, Min Sheng, Dong Qu, Xin Wang, Jianghong Meng. (2011) Mutations in gyrase and topoisomerase genes associated with fluoroquinolone resistance in Salmonella serovars from retail meats. Food Research International
    CrossRef

  19. 19

    S.N. Melendez, I. Hanning, J. Han, R. Nayak, A.R. Clement, A. Wooming, P. Hererra, F.T. Jones, S.L. Foley, S.C. Ricke. (2010) Salmonella enterica isolates from pasture-raised poultry exhibit antimicrobial resistance and class I integrons. Journal of Applied Microbiology 109:6, 1957-1966
    CrossRef

  20. 20

    Deirdre L. Church, Diana Emshey, Tracie Lloyd, Johann Pitout. (2010) Clinical and economic evaluation of BBL™ CHROMagar™ Salmonella (CHROMSal) versus subculture after selenite broth enrichment to CHROMSal and Hektoen enteric agars to detect enteric Salmonella in a large regional microbiology laboratory. Diagnostic Microbiology and Infectious Disease 68:1, 13-19
    CrossRef

  21. 21

    Kunihiro Nakata, Myo Myoung Koh, Tetsuaki Tsuchido, Yoshinobu Matsumura. (2010) All genomic mutations in the antimicrobial surfactant-resistant mutant, Escherichia coli OW66, are involved in cell resistance to surfactant. Applied Microbiology and Biotechnology 87:5, 1895-1905
    CrossRef

  22. 22

    A. Maripandi, Ali A. Al-Salamah. (2010) Multiple-Antibiotic Resistance and Plasmid Profiles of Salmonella enteritidis Isolated from Retail Chicken Meats. American Journal of Food Technology 5:4, 260-268
    CrossRef

  23. 23

    O. Iseri, I. Erol. (2010) Incidence and antibiotic resistance of Salmonella spp. in ground turkey meat. British Poultry Science 51:1, 60-66
    CrossRef

  24. 24

    Scientific Advisory Group on Antimi. (2009) Reflection paper on the use of third and fourth generation cephalosporins in food producing animals in the European Union: development of resistance and impact on human and animal health. Journal of Veterinary Pharmacology and Therapeutics 32:6, 515-533
    CrossRef

  25. 25

    Ashraf M. Ahmed, Hirofumi Shimabukuro, Tadashi Shimamoto. (2009) Isolation and Molecular Characterization of Multidrug-Resistant Strains of  Escherichia coli  and  Salmonella  from Retail Chicken Meat in Japan. Journal of Food Science 74:7, M405-M410
    CrossRef

  26. 26

    Kimberly A. Alexander, Lorin D. Warnick, Martin Wiedmann. (2009) Antimicrobial resistant Salmonella in dairy cattle in the United States. Veterinary Research Communications 33:3, 191-209
    CrossRef

  27. 27

    Aaron M. Lynne, Pravin Kaldhone, Donna David, David G. White, Steven L. Foley. (2009) Characterization of Antimicrobial Resistance in Salmonella enterica Serotype Heidelberg Isolated from Food Animals. Foodborne Pathogens and Disease 6:2, 207-215
    CrossRef

  28. 28

    Sheryl P. Gow, Cheryl L. Waldner. (2009) Antimicrobial Resistance and Virulence Factors stx 1, stx 2, and eae in Generic Escherichia coli Isolates from Calves in Western Canadian Cow-Calf Herds. Microbial Drug Resistance 15:1, 61-67
    CrossRef

  29. 29

    R. Elgroud, F. Zerdoumi, M. Benazzouz, C. Bouzitouna-Bentchouala, S. A. Granier, S. Frémy, A. Brisabois, B. Dufour, Y. Millemann. (2009) Characteristics of Salmonella Contamination of Broilers and Slaughterhouses in the Region of Constantine (Algeria). Zoonoses and Public Health 56:2, 84-93
    CrossRef

  30. 30

    Gwenaëlle Le Blay, Julia Rytka, Annina Zihler, Christophe Lacroix. (2009) New in vitro colonic fermentation model for Salmonella infection in the child gut. FEMS Microbiology Ecology 67:2, 198-207
    CrossRef

  31. 31

    Endrias Zewdu, Poppe Cornelius. (2009) Antimicrobial resistance pattern of Salmonella serotypes isolated from food items and personnel in Addis Ababa, Ethiopia. Tropical Animal Health and Production 41:2, 241-249
    CrossRef

  32. 32

    Patrick Boerlin, Richard J. Reid-Smith. (2008) Antimicrobial resistance: its emergence and transmission. Animal Health Research Reviews 9:02, 115
    CrossRef

  33. 33

    Howard Frumkin, Anthony J. McMichael. (2008) Climate Change and Public Health. American Journal of Preventive Medicine 35:5, 403-410
    CrossRef

  34. 34

    Lee Learn-Han, Cheah Yoke-Kqueen, Noorzaleha Awang Salleh, Sabrina Sukardi, Sim Jiun-Horng, Khoo Chai-Hoon, Son Radu. (2008) Analysis of Salmonella Agona and Salmonella Weltevreden in Malaysia by PCR fingerprinting and antibiotic resistance profiling. Antonie van Leeuwenhoek 94:3, 377-387
    CrossRef

  35. 35

    R. Finley, R. Reid-Smith, C. Ribble, M. Popa, M. Vandermeer, J. Aramini. (2008) The Occurrence and Antimicrobial Susceptibility of Salmonellae Isolated from Commercially Available Canine Raw Food Diets in Three Canadian Cities. Zoonoses and Public Health 55:8-10, 462-469
    CrossRef

  36. 36

    C. Leifert, K. Ball, N. Volakakis, J.M. Cooper. (2008) Control of enteric pathogens in ready-to-eat vegetable crops in organic and ‘low input’ production systems: a HACCP-based approach. Journal of Applied Microbiology 105:4, 931-950
    CrossRef

  37. 37

    Yifan Zhang, Jeffrey T. LeJeune. (2008) Transduction of blaCMY-2, tet(A), and tet(B) from Salmonella enterica subspecies enterica serovar Heidelberg to S. Typhimurium. Veterinary Microbiology 129:3-4, 418-425
    CrossRef

  38. 38

    Giuseppina Chiaretto, Paola Zavagnin, Francesca Bettini, Marzia Mancin, Claudio Minorello, Cristina Saccardin, Antonia Ricci. (2008) Extended spectrum β-lactamase SHV-12-producing Salmonella from poultry. Veterinary Microbiology 128:3-4, 406-413
    CrossRef

  39. 39

    Antoine Stevens, Annaelle Kerouanton, Muriel Marault, Yves Millemann, Anne Brisabois, Jean-François Cavin, Barbara Dufour. (2008) Epidemiological analysis of Salmonella enterica from beef sampled in the slaughterhouse and retailers in Dakar (Senegal) using pulsed-field gel electrophoresis and antibiotic susceptibility testing. International Journal of Food Microbiology 123:3, 191-197
    CrossRef

  40. 40

    Natsue OGASAWARA, Thi Phan TRAN, Thi Lien Khai LY, Thu Tam NGUYEN, Taketoshi IWATA, Alexandre Tomomitsu OKATANI, Maiko WATANABE, Takahide TANIGUCHI, Yoshikazu HIROTA, Hideki HAYASHIDANI. (2008) Antimicrobial Susceptibilities of Salmonella from Domestic Animals, Food and Human in the Mekong Delta, Vietnam. Journal of Veterinary Medical Science 70:11, 1159-1164
    CrossRef

  41. 41

    Caroline Compain, Laetitia Michou, Philippe Orcel, Didier Hannouche, Pascal Richette. (2008) Septic arthritis of the hip with psoas abscess caused by Non-typhi Salmonella infection in an immunocompetent patient. Joint Bone Spine 75:1, 67-69
    CrossRef

  42. 42

    Margaret L. Khaitsa, Redempta B. Kegode, Dawn K. Doetkott. (2007) Occurrence of Antimicrobial-Resistant Salmonella Species in Raw and Ready to Eat Turkey Meat Products from Retail Outlets in the Midwestern United States. Foodborne Pathogens and Disease 4:4, 517-525
    CrossRef

  43. 43

    BURTON W. BLAIS, AMALIA MARTINEZ-PEREZ, JOHANNA LEGGATE, MARTINE GAUTHIER. (2007) DETECTION OF MULTIDRUG-RESISTANT SALMONELLA TYPHIMURIUM DT104 IN POULTRY BY SELECTIVE ENRICHMENT AND CLOTH-BASED HYBRIDIZATION ARRAY SYSTEM. Journal of Rapid Methods and Automation in Microbiology 15:4, 332-344
    CrossRef

  44. 44

    Vijay K. Juneja. (2007) Thermal inactivation of Salmonella spp. in ground chicken breast or thigh meat. International Journal of Food Science & Technology 42:12, 1443-1448
    CrossRef

  45. 45

    Jeffrey M Gilbert, David G White, Patrick F McDermott. (2007) The US National Antimicrobial Resistance Monitoring System. Future Microbiology 2:5, 493-500
    CrossRef

  46. 46

    M. KIVI, A. HOFHUIS, D. W. NOTERMANS, W. J. B. WANNET, M. E. O. C. HECK, A. W. VAN DE GIESSEN, Y. T. H. P. VAN DUYNHOVEN, O. F. J. STENVERS, A. BOSMAN, W. VAN PELT. (2007) A beef-associated outbreak of Salmonella Typhimurium DT104 in The Netherlands with implications for national and international policy. Epidemiology and Infection 135:06, 890
    CrossRef

  47. 47

    Xian-Zhi Li, Manisha Mehrotra, Shiva Ghimire, Lateef Adewoye. (2007) β-Lactam resistance and β-lactamases in bacteria of animal origin. Veterinary Microbiology 121:3-4, 197-214
    CrossRef

  48. 48

    S.-H. Kim, C.-I. Wei. (2007) Invasiveness and Intracellular Growth of Multidrug-Resistant Salmonella and Other Pathogens in Caco-2 Cells. Journal of Food Science 72:2, M72-M78
    CrossRef

  49. 49

    Amy R. Sapkota, Lisa Y. Lefferts, Shawn McKenzie, Polly Walker. (2007) What Do We Feed to Food-Production Animals? A Review of Animal Feed Ingredients and Their Potential Impacts on Human Health. Environmental Health Perspectives 115:5, 663-670
    CrossRef

  50. 50

    C.A. Thorrold, M.E. Letsoalo, A.G. Dusé, E. Marais. (2007) Efflux pump activity in fluoroquinolone and tetracycline resistant Salmonella and E. coli implicated in reduced susceptibility to household antimicrobial cleaning agents. International Journal of Food Microbiology 113:3, 315-320
    CrossRef

  51. 51

    P.-L. Chen, C.-M. Chang, C.-J. Wu, N.-Y. Ko, N.-Y. Lee, H.-C. Lee, H.-I. Shih, C.-C. Lee, R.-R. Wang, W.-C. Ko. (2007) Extraintestinal focal infections in adults with nontyphoid Salmonella bacteraemia: predisposing factors and clinical outcome. Journal of Internal Medicine 261:1, 91-100
    CrossRef

  52. 52

    H. Harbottle, S. Thakur, S. Zhao, D. G. White. (2006) Genetics of Antimicrobial Resistance. Animal Biotechnology 17:2, 111-124
    CrossRef

  53. 53

    Xiuping Jiang, Hua Yang, Brittany Dettman, Michael P. Doyle. (2006) Analysis of Fecal Microbial Flora for Antibiotic Resistance in Ceftiofur-Treated Calves. Foodborne Pathogens and Disease 3:4, 355-365
    CrossRef

  54. 54

    Mohamed K. Fakhr, Julie S. Sherwood, Jessica Thorsness, Catherine M. Logue. (2006) Molecular Characterization and Antibiotic Resistance Profiling of Salmonella Isolated from Retail Turkey Meat Products. Foodborne Pathogens and Disease 3:4, 366-374
    CrossRef

  55. 55

    Mary J. Gilchrist, Christina Greko, David B. Wallinga, George W. Beran, David G. Riley, Peter S. Thorne. (2006) The Potential Role of Concentrated Animal Feeding Operations in Infectious Disease Epidemics and Antibiotic Resistance. Environmental Health Perspectives 115:2, 313-316
    CrossRef

  56. 56

    Hua Yang, Brittany Dettman, Jonathan Beam, Caroline Mix, Xiuping Jiang. (2006) Occurrence of ceftriaxone-resistant commensal bacteria on a dairy farm and a poultry farm. Canadian Journal of Microbiology 52:10, 942-950
    CrossRef

  57. 57

    M DOYLE, M ERICKSON. (2006) Emerging microbiological food safety issues related to meat. Meat Science 74:1, 98-112
    CrossRef

  58. 58

    Guillaume Arlet, Timothy J. Barrett, Patrick Butaye, Axel Cloeckaert, Michael R. Mulvey, David G. White. (2006) Salmonella resistant to extended-spectrum cephalosporins: prevalence and epidemiology. Microbes and Infection 8:7, 1945-1954
    CrossRef

  59. 59

    F. J. Angulo, E. A. Talbot, E. R. Gagnon, J. Greenblatt. (2006) Common Ground for the Control of Multidrug-Resistant Salmonella in Ground Beef. Clinical Infectious Diseases 42:10, 1455-1462
    CrossRef

  60. 60

    A. M. Dechet, E. Scallan, K. Gensheimer, R. Hoekstra, J. Gunderman-King, J. Lockett, D. Wrigley, W. Chege, J. Sobel, . (2006) Outbreak of Multidrug-Resistant Salmonella enterica Serotype Typhimurium Definitive Type 104 Infection Linked to Commercial Ground Beef, Northeastern United States, 2003-2004. Clinical Infectious Diseases 42:6, 747-752
    CrossRef

  61. 61

    Neema Mrema, Sisai Mpuchane, Berhanu A. Gashe. (2006) Prevalence of Salmonella in raw minced meat, raw fresh sausages and raw burger patties from retail outlets in Gaborone, Botswana. Food Control 17:3, 207-212
    CrossRef

  62. 62

    S. Zhao, P.F. McDermott, S. Friedman, J. Abbott, S. Ayers, A. Glenn, E. Hall-Robinson, S.K. Hubert, H. Harbottle, R.D. Walker, T.M. Chiller, D.G. White. (2006) Antimicrobial Resistance and Genetic Relatedness Among Salmonella from Retail Foods of Animal Origin: NARMS Retail Meat Surveillance. Foodborne Pathogens and Disease 3:1, 106-117
    CrossRef

  63. 63

    Christina Viola, Stephen J. DeVincent. (2006) Overview of issues pertaining to the manufacture, distribution, and use of antimicrobials in animals and other information relevant to animal antimicrobial use data collection in the United States. Preventive Veterinary Medicine 73:2-3, 111-131
    CrossRef

  64. 64

    B. Jones. 2006. Foodborne microbes' mechanisms of colonization, attachment and invasion. , 271-291.
    CrossRef

  65. 65

    D. I. Ellis, R. Goodacre. 2006. Quantitative detection and identification methods for microbial spoilage. , 3-27.
    CrossRef

  66. 66

    E. Yoko Furuya, Franklin D. Lowy. (2006) Antimicrobial-resistant bacteria in the community setting. Nature Reviews Microbiology 4:1, 36-45
    CrossRef

  67. 67

    Rose A. Devasia, Jay K. Varma, Jean Whichard, Sonya Gettner, Alicia B. Cronquist, Sharon Hurd, Suzanne Segler, Kirk Smith, Dina Hoefer, Beletshachew Shiferaw, Frederick J. Angulo, Timothy F. Jones. (2005) Antimicrobial Use and Outcomes in Patients with Multidrug-Resistant and Pansusceptible Salmonella Newport Infections, 2002–2003. Microbial Drug Resistance 11:4, 371-377
    CrossRef

  68. 68

    Stephanie D. Wedel, Jeffrey B. Bender, Fe T. Leano, David J. Boxrud, Craig Hedberg, Kirk E. Smith. (2005) Antimicrobial-drug Susceptibility of Human and Animal Salmonella Typhimurium, Minnesota, 1997–2003. Emerging Infectious Diseases 11:12, 1899-1906
    CrossRef

  69. 69

    A ALANIS. (2005) Resistance to Antibiotics: Are We in the Post-Antibiotic Era?. Archives of Medical Research 36:6, 697-705
    CrossRef

  70. 70

    Eden Ephraim, Mogessie Ashenafi. (2005) Fate of Salmonella typhimurium DT 104 during the Fermentation of ‘Siljo’, a Traditional Ethiopian Fermented Legume Condiment, and during Product Storage at Ambient and Refrigeration Temperatures. World Journal of Microbiology and Biotechnology 21:6-7, 1259-1265
    CrossRef

  71. 71

    Miranda Batchelor, E John Threlfall, Ernesto Liebana. (2005) Cephalosporin resistance among animal-associated Enterobacteria : a current perspective. Expert Review of Anti-infective Therapy 3:3, 403-417
    CrossRef

  72. 72

    S. Zhao, P.J. Fedorka-Cray, S. Friedman, P.F. McDermott, R.D. Walker, S. Qaiyumi, S.L. Foley, S.K. Hubert, S. Ayers, L. English, D.A. Dargatz, B. Salamone, D.G. White. (2005) Characterization of Salmonella Typhimurium of Animal Origin Obtained from the National Antimicrobial Resistance Monitoring System. Foodborne Pathogens and Disease 2:2, 169-181
    CrossRef

  73. 73

    S CHEN, S ZHAO, P MCDERMOTT, C SCHROEDER, D WHITE, J MENG. (2005) A DNA microarray for identification of virulence and antimicrobial resistance genes in serovars and. Molecular and Cellular Probes 19:3, 195-201
    CrossRef

  74. 74

    Karen A. Liljebjelke, Charles L. Hofacre, Tongrui Liu, David G. White, Sherry Ayers, Suzanne Young, John J. Maurer. (2005) Vertical and Horizontal Transmission of Salmonella Within Integrated Broiler Production System. Foodborne Pathogens and Disease 2:1, 90-102
    CrossRef

  75. 75

    David G. White, Shaohua Zhao, Ruby Singh, Patrick F. McDermott. (2004) Antimicrobial Resistance Among Gram-Negative Foodborne Bacterial Pathogens Associated with Foods of Animal Origin. Foodborne Pathogens and Disease 1:3, 137-152
    CrossRef

  76. 76

    V Miriagou, P.T Tassios, N.J Legakis, L.S Tzouvelekis. (2004) Expanded-spectrum cephalosporin resistance in non-typhoid Salmonella. International Journal of Antimicrobial Agents 23:6, 547-555
    CrossRef

  77. 77

    A. C. Fluit, F.-J. Schmitz. (2004) Resistance integrons and super-integrons. Clinical Microbiology and Infection 10:4, 272-288
    CrossRef

  78. 78

    Benoît Doublet, Alessandra Carattoli, Jean M Whichard, David G White, Sylvie Baucheron, Elisabeth Chaslus-Dancla, Axel Cloeckaert. (2004) Plasmid-mediated florfenicol and ceftriaxone resistance encoded by the floR and bla CMY-2 genes in Salmonella enterica serovars Typhimurium and Newport isolated in the United States. FEMS Microbiology Letters 233:2, 301-305
    CrossRef

  79. 79

    M. Gauthier, B.W. Blais. (2004) Cloth-based hybridization array system for the detection of multiple antibiotic resistance genes in Salmonella enterica subsp. enterica serotype Typhimurium DT104. Letters in Applied Microbiology 38:4, 265-270
    CrossRef

  80. 80

    Manuel L. Fern??ndez Guerrero, Jos?? Maria Aguado, Ana Arribas, Carlos Lumbreras, Miguel de Gorgolas. (2004) The Spectrum of Cardiovascular Infections due to Salmonella enterica. Medicine 83:2, 123-138
    CrossRef

  81. 81

    Emanuel Goldman. (2004) Antibiotic Abuse in Animal Agriculture: Exacerbating Drug Resistance in Human Pathogens. Human and Ecological Risk Assessment: An International Journal 10:1, 121-134
    CrossRef

  82. 82

    J Ellingson. (2004) Twelve hour real-time PCR technique for the sensitive and specific detection of Salmonella in raw and ready-to-eat meat products. Molecular and Cellular Probes 18:1, 51-57
    CrossRef

  83. 83

    S. Omaye. 2004. Introduction to food toxicology. , 1-26.
    CrossRef

  84. 84

    Kathryn A DeFrancesco, Rowland N Cobbold, Daniel H Rice, Thomas E Besser, Dale D Hancock. (2004) Antimicrobial resistance of commensal Escherichia coli from dairy cattle associated with recent multi-resistant salmonellosis outbreaks. Veterinary Microbiology 98:1, 55-61
    CrossRef

  85. 85

    AD Russell. (2003) Biocide use and antibiotic resistance: the relevance of laboratory findings to clinical and environmental situations. The Lancet Infectious Diseases 3:12, 794-803
    CrossRef

  86. 86

    Linda L. Tikofsky, John W. Barlow, Carlos Santisteban, Ynte H. Schukken. (2003) A Comparison of Antimicrobial Susceptibility Patterns for Staphylococcus aureus in Organic and Conventional Dairy Herds. Microbial Drug Resistance 9:supplement 1, 39-45
    CrossRef

  87. 87

    R. B. Hsu, Y. G. Tsay, S. S. Wang, S. H. Chu. (2003) Management of aortic aneurysm infected withSalmonella. British Journal of Surgery 90:9, 1080-1084
    CrossRef

  88. 88

    Shaohua Zhao, Atin R. Datta, Sherry Ayers, Sharon Friedman, Robert D. Walker, David G. White. (2003) Antimicrobial-resistant Salmonella serovars isolated from imported foods. International Journal of Food Microbiology 84:1, 87-92
    CrossRef

  89. 89

    John A. Crump, Timothy J. Barrett, Jennifer T. Nelson, Frederick J. Angulo. (2003) Reevaluating Fluoroquinolone Breakpoints for Salmonella enterica Serotype Typhi and for Non‐Typhi Salmonellae. Clinical Infectious Diseases 37:1, 75-81
    CrossRef

  90. 90

    W. Liu, S. J. Lamont. (2003) Candidate Gene Approach: Potentional Association of Caspase‐1 , Inhibitor of Apoptosis Protein‐1 , and Prosaposin Gene Polymorphisms with Response to Salmonella enteritidis Challenge or Vaccination in Young Chicks. Animal Biotechnology 14:1, 61-76
    CrossRef

  91. 91

    P.L. Ruegg. (2003) Practical Food Safety Interventions for Dairy Production. Journal of Dairy Science 86, E1-E9
    CrossRef

  92. 92

    Ron‐Bin Hsu, Yeou‐Guang Tsay, Robert J. Chen, Shu‐Hsun Chu. (2003) Risk Factors for Primary Bacteremia and Endovascular Infection in Patients without Acquired Immunodeficiency Syndrome Who Have Nontyphoid Salmonellosis. Clinical Infectious Diseases 36:7, 829-834
    CrossRef

  93. 93

    B. Catry, H. Laevens, L.A. Devriese, G. Opsomer, A. Kruif. (2003) Antimicrobial resistance in livestock. Journal of Veterinary Pharmacology and Therapeutics 26:2, 81-93
    CrossRef

  94. 94

    Stavros Sougioultzis, Charalabos Pothoulakis. (2003) Bacterial infections: small intestine and colon. Current Opinion in Gastroenterology 19:1, 23-30
    CrossRef

  95. 95

    Ying Mao, Chengru Zhu, Edgar C. Boedeker. (2003) Foodborne enteric infections. Current Opinion in Gastroenterology 19:1, 11-22
    CrossRef

  96. 96

    Bruce A. Wagner, David A. Dargatz, M.D. Salman, Paul S. Morley, Thomas E. Wittum, Thomas J. Keefe. (2002) Comparison of sampling techniques for measuring the antimicrobial susceptibility of enteric Escherichia colirecovered from feedlot cattle. American Journal of Veterinary Research 63:12, 1662-1670
    CrossRef

  97. 97

    Linda Tollefson, William T. Flynn. (2002) Impact of antimicrobial resistance on regulatory policies in veterinary medicine: Status report. AAPS PharmSci 4:4, 150-159
    CrossRef

  98. 98

    Elena Chiappini, Luisa Galli, Patrizia Pecile, Alberto Vierucci, Maurizio de Martino. (2002) Results of a 5-year prospective surveillance study of antibiotic resistance among Salmonella enterica isolates and ceftriaxone therapy among children hospitalized for acute diarrhea. Clinical Therapeutics 24:10, 1585-1594
    CrossRef

  99. 99

    Henning Sørum, Trine Marie L'Abée-Lund. (2002) Antibiotic resistance in food-related bacteria—a result of interfering with the global web of bacterial genetics. International Journal of Food Microbiology 78:1-2, 43-56
    CrossRef

  100. 100

    Sean F. Altekruse, Francois Elvinger, Kyung-Yul Lee, Linda K. Tollefson, F. William Pierson, Joseph Eifert, Nammalwar Sriranganathan. (2002) Antimicrobial susceptibilities of Escherichia coli strains from a turkey operation. Journal of the American Veterinary Medical Association 221:3, 411-416
    CrossRef

  101. 101

    Eric J. Kasowski, Gary D. Gackstetter, Trueman W. Sharp. (2002) Foodborne illness: New developments concerning an old problem. Current Gastroenterology Reports 4:4, 308-318
    CrossRef

  102. 102

    Morton N. Swartz. (2002) Human Diseases Caused by Foodborne Pathogens of Animal Origin. Clinical Infectious Diseases 34:s3, S111-S122
    CrossRef

  103. 103

    (2002) Resistant Bacteria in Retail Meats and Antimicrobial Use in Animals. New England Journal of Medicine 346:10, 777-779
    Full Text

  104. 104

    Chiu, Cheng-Hsun, Wu, Tsu-Lan, Su, Lin-Hui, Chu, Chishih, Chia, Ju-Hsin, Kuo, An-Jing, Chien, Maw-Sheng, Lin, Tzou-Yien, . (2002) The Emergence in Taiwan of Fluoroquinolone Resistance in Salmonella enterica Serotype Choleraesuis. New England Journal of Medicine 346:6, 413-419
    Full Text

  105. 105

    David I Ellis, Royston Goodacre. (2001) Rapid and quantitative detection of the microbial spoilage of muscle foods: current status and future trends. Trends in Food Science & Technology 12:11, 414-424
    CrossRef

  106. 106

    Gorbach, Sherwood L., . (2001) Antimicrobial Use in Animal Feed — Time to Stop. New England Journal of Medicine 345:16, 1202-1203
    Full Text

  107. 107

    &NA;. (2001) Antibacterial use in animal feed must stop. Inpharma Weekly &amp;NA;:1311, 3
    CrossRef

  108. 108

    Dudley G. Anderson, John L. Clark. (1974) Neighborhood Screening in Communities Throughout the Nation for Children with Elevated Blood Lead Levels. Environmental Health Perspectives 7, 3-6
    CrossRef