Emergence of Multidrug-Resistant Salmonella enterica SerotypeTyphimurium DT104 Infections in the United States
M. Kathleen Glynn, D.V.M., M.P.V.M., Cheryl Bopp, M.S., Wallis Dewitt, M.P.H., Paul Dabney, M.S., Mohammad Mokhtar, M.D., M.P.H., and Frederick J. Angulo, D.V.M., Ph.D.
Background Strains of salmonella that are resistant to antimicrobialagents have become a worldwide health problem. A distinct strainof Salmonella enterica serotype typhimurium, known as definitivetype 104 (DT104), is resistant to ampicillin, chloramphenicol,streptomycin, sulfonamides, and tetracycline and has becomea major cause of illness in humans and animals in Europe, especiallythe United Kingdom.
Methods To characterize typhimurium DT104 infections in theUnited States, we analyzed data collected by local and statehealth departments and public health laboratories between 1979and 1996 in national surveys of the antimicrobial-drug resistanceof salmonella. Selected typhimurium isolates with the five-drugpattern of resistance were phage typed.
Results The prevalence of typhimurium isolates with the five-drugpattern of resistance increased from 0.6 percent in 1979–1980to 34 percent in 1996. In 1994–1995, such isolates wereidentified in samples from 36 of the 46 surveillance sites (78percent). Thirty-nine of 43 typhimurium isolates with the five-drugpattern of resistance identified in 1994–1995 and 1996were phage type DT104 or a closely related phage type.
Conclusions Multidrug-resistant typhimurium DT104 has becomea widespread pathogen in the United States. More prudent useof antimicrobial agents in farm animals and more effective diseaseprevention on farms are necessary to reduce the disseminationof multidrug-resistant typhimurium DT104 and to slow the emergenceof resistance to additional agents in this and other strainsof salmonella.
Each year in the United States, there are an estimated 800,000to 4 million salmonella infections, and approximately 500 arefatal.1 Approximately 40,000 of these infections are confirmedby culture; isolates are serotyped at state public health laboratoriesand reported to the Centers for Disease Control and Prevention(CDC).2 Although most salmonella infections are self-limited,bacteremia occurs in 3 to 10 percent of reported, culture-confirmedcases, particularly in cases involving patients at the extremesof age or those who are immunocompromised.3,4,5,6,7 For thesepatients, appropriate antimicrobial-drug therapy can be lifesaving.1,3
In recent years, testing of salmonella isolates in the UnitedStates8,9 and abroad10,11 has shown that an increasing proportionof isolates are resistant to several antimicrobial agents. Inthe United Kingdom, the marked increase in the incidence ofa distinct multidrug-resistant strain of Salmonella entericaserotype typhimurium (hereafter referred to as typhimurium),characterized as definitive type 104 (DT104), that is resistantto five agents — ampicillin, chloramphenicol, streptomycin,sulfonamides, and tetracycline — has been of particularconcern. A recent report from the United Kingdom suggests thatinfections caused by this five-drug–resistant typhimuriummight be associated with greater morbidity and mortality thanother salmonella infections.12 Of further concern, 14 percentof such isolates that were identified in the United Kingdomin 1996 were also resistant to ciprofloxacin, and 24 percentwere resistant to trimethoprim; in each case the level of resistancewas 0 percent in 1991.13 We report on the widespread emergenceof typhimurium DT104 in the United States.
Methods
In the United States, state public health laboratories reportculture-confirmed cases of salmonella to the CDC by means ofthe Public Health Laboratory Information System, a nationwideelectronic reporting system. Information on the antimicrobial-drugresistance of salmonella is available from several sources:the National Antimicrobial Resistance Monitoring System establishedin 1996, the 1995 National Salmonella Antimicrobial ResistanceStudy, and surveys of antimicrobial-drug resistance that wereconducted in sentinel counties in 1979–1980, 1984–1985,1989–1990, and 1994–1995. We examined data collectedby these systems and surveys to identify reports of typhimuriumDT104.
Public Health Laboratory Information System
As a part of routine public health surveillance, most clinicallaboratories in the United States routinely forward salmonellaisolates to state or territorial public health laboratoriesfor serotyping, and state public health laboratories reportculture-confirmed salmonella infections, usually after serotyping,to epidemiologists in their state and to the CDC.2,14
National Antimicrobial Resistance Monitoring System
Salmonella isolates are not usually forwarded to the CDC; theexceptions are atypical or rare isolates sent for confirmatoryserotyping and those included in special surveys of antimicrobial-drugresistance. One such survey, the recently established NationalAntimicrobial Resistance Monitoring System, was begun in January1996 in collaboration with 12 state health departments (California,Colorado, Connecticut, Florida, Georgia, Kansas, Massachusetts,Minnesota, New Jersey, Oregon, Washington, and West Virginia)and 2 local health departments (Los Angeles County and New YorkCity) to monitor prospectively the patterns of antimicrobial-drugresistance of human salmonella isolates received at participatingpublic health laboratories.15 Participants forward every 10thsalmonella isolate to the CDC for testing for susceptibilityto antimicrobial agents. Isolates are tested with a Sensititresystem (Accumed International, Westlake, Ohio), which determinesthe minimal inhibitory concentration for 15 antimicrobial agents:ampicillin, amoxicillin–clavulanic acid, apramycin, ceftiofur,ceftriaxone, cephalothin, chloramphenicol, ciprofloxacin, gentamicin,kanamycin, nalidixic acid, streptomycin, sulfamethoxazole, tetracycline,and trimethoprim–sulfamethoxazole. After testing, a randomsample of typhimurium isolates that are resistant to ampicillin,chloramphenicol, streptomycin, sulfonamides, and tetracyclineare phage typed at the CDC,16 and strains are classified asDT104, DT104 complex (other closely related definitive typesor closely related untypable strains), or unrelated to DT104.
National Salmonella Antimicrobial Resistance Study
The second source of data on the resistance of salmonella toantimicrobial agents was the National Salmonella AntimicrobialResistance Study conducted between July 1, 1994, and June 30,1995. All state and territorial public health laboratories wereasked to forward every 10th salmonella isolate to the CDC forantimicrobial-drug–susceptibility testing. Isolates weretested by the disk–diffusion method for resistance to12 antimicrobial agents: ampicillin, amoxicillin–clavulanicacid, ceftriaxone, chloramphenicol, ciprofloxacin, gentamicin,kanamycin, nalidixic acid, streptomycin, sulfisoxazole, tetracycline,and trimethoprim–sulfamethoxazole.17 A random sample oftyphimurium isolates with resistance to ampicillin, chloramphenicol,streptomycin, sulfonamides, and tetracycline was sent to theDanish Veterinary Laboratory (Copenhagen, Denmark) and the WorldHealth Organization International Center for Enteric Phage Typing(Collindale, United Kingdom) for phage typing16; strains wereclassified as DT104, DT104 complex, or unrelated to DT104.
Periodic Surveys of Antimicrobial-Drug Resistance in Sentinel Counties
The third source of data was a series of surveys conducted inselected counties in the United States. These surveys were conductedevery five years in a volunteer panel of counties, initiallychosen in 1979.18 Trends in antimicrobial-drug resistance overtime were examined with the use of data from the 23 countiesthat participated in each of the surveys, conducted over one-yearperiods from July 1 to June 30 in 1979–1980,18 1984–1985,91989–1990,8 and 1994–1995. The participating countieswere in California, Massachusetts, New Jersey, New Mexico, NewYork, North Carolina, Ohio, Pennsylvania, Rhode Island, Texas,and Vermont. These health departments were asked to send allsalmonella isolates collected in their counties during the surveyperiods to the CDC, except those associated with an outbreak.In each of the surveys, the isolates were tested with the disk-diffusionmethod for resistance to nine antimicrobial agents: ampicillin,chloramphenicol, gentamicin, kanamycin, nalidixic acid, streptomycin,sulfisoxazole, tetracycline, and trimethoprim–sulfamethoxazole.17After testing, typhimurium isolates with the five-drug patternof resistance from the 1979–1980, 1984–1985, and1989–1990 surveys were phage typed at the CDC16; strainswere classified as DT104, DT104 complex, or unrelated to DT104.
Results
Public Health Laboratory Information System
In 1996, a total of 39,032 culture-confirmed salmonella infectionswere reported to the CDC by state public health laboratories.Of the 38,218 isolates that were serotyped, 9566 (25 percent)were classified as S. enterica serotype enteritidis, the mostcommonly identified serotype, and 9501 (25 percent) as typhimurium.Although the percentage of serotyped salmonella isolates thatare identified as S. enterica serotype enteritidis increasedfrom 16 percent in 1987 to 25 percent in 1996, reflecting adecade-long problem associated with contamination of eggs, thepercentage of typhimurium isolates identified during that periodincreased only slightly, from 24 percent to 25 percent.19
National Antimicrobial Resistance Monitoring System
In 1996, 1326 salmonella isolates were received at the CDC throughthe National Antimicrobial Resistance Monitoring System, and1239 (93 percent) were serotyped (Table 1). Three hundred six(25 percent) of the serotyped isolates were classified as typhimurium;103 of the 306 (34 percent) were resistant to ampicillin, chloramphenicol,streptomycin, sulfonamides, and tetracycline. Of 13 isolateswith the five-drug pattern of resistance that were phage typedat the CDC, 9 (69 percent) were identified as DT104, 2 as DT104complex, and 2 as having unrelated phage types. The five-drugpattern of resistance was identified in isolates from 12 of13 sites that submitted typhimurium isolates; more than 50 percentof the typhimurium isolates from California and Connecticuthad this pattern. Among the five antimicrobial drugs, the mostspecific marker for this pattern of resistance was resistanceto chloramphenicol: 103 of the 122 chloramphenicol-resistanttyphimurium isolates (84 percent) were also resistant to ampicillin,streptomycin, sulfonamides, and tetracycline. None of the 306typhimurium isolates were resistant to ciprofloxacin. One isolatewas resistant to nalidixic acid, but it did not have the five-drugpattern of resistance.
Table 1. Characteristics of Typhimurium Isolates Reported in Three Surveys of Antimicrobial-Drug Resistance in Salmonella in the United States, 1979 to 1996.
National Salmonella Antimicrobial Resistance Study
Patterns of resistance to antimicrobial agents were also determinedfor 4008 salmonella isolates received from 51 states or territoriesfrom July 1, 1994, through June 30, 1995, through the NationalSalmonella Antimicrobial Resistance Study, and 3903 (97 percent)were serotyped (Table 1). Of these 3903 isolates, 976 (25 percent)were identified as typhimurium, 275 (28 percent) of which wereresistant to ampicillin, chloramphenicol, streptomycin, sulfonamides,and tetracycline. Isolates resistant to these five drugs wereidentified at 36 of the 46 sites (78 percent) that submittedtyphimurium isolates, with the highest proportional prevalencein the western United States. The states in which more than40 percent of typhimurium isolates had this pattern of resistancewere California, Kentucky, Nevada, Oregon, Utah, and Washington.Thirty of the 275 isolates with the five-drug pattern of resistancethat were submitted to the CDC were phage typed: 25 (83 percent)were identified as DT104, 3 as DT104 complex, and 2 as unrelateddefinitive types.
In this series of isolates, resistance to chloramphenicol wasagain the most specific marker for the five-drug pattern ofresistance: 275 of the 285 chloramphenicol-resistant isolates(96 percent) had this pattern of resistance. None of the 701typhimurium isolates were resistant to ciprofloxacin. Two ofthe 275 isolates with the five-drug pattern of resistance (0.7percent) were also resistant to nalidixic acid, as comparedwith 3 of the 701 isolates (0.4 percent) with other patternsof resistance or no resistance; the median diameters and distributionsof the disk-diffusion zone for nalidixic acid were similar inthe two groups.
Periodic Surveys of Antimicrobial-Drug Resistance in Sentinel Counties
The periodic surveys conducted in the 23 selected counties furtherdemonstrated the emergence of a pattern of resistance to ampicillin,chloramphenicol, streptomycin, sulfonamides, and tetracyclineamong typhimurium isolates in the United States. The prevalenceof this pattern was 0.6 percent (1 of 162 isolates) in 1979–1980,5 percent (7 of 135) in 1984–1985, 7 percent (8 of 108)in 1989–1990, and 19 percent (31 of 166) in 1994–1995(Figure 1). Among the 16 such isolates identified between 1979and 1990, 1 (14 percent) in 1984–1985 and 3 (38 percent)in 1989–1990 were typed as DT104 or DT104 complex.
Figure 1. Prevalence of Resistance to Ampicillin, Chloramphenicol, Streptomycin, Sulfonamides, and Tetracycline among Typhimurium Isolates Identified by Surveys of Antimicrobial-Drug Resistance in Sentinel Counties.
Each survey was conducted from July 1 to June 30.
Discussion
In the past five years in the United States there has been widespreademergence of a strain of typhimurium that is resistant to fivemajor antibiotics: ampicillin, chloramphenicol, streptomycin,sulfonamides, and tetracycline. Although the number of casesof typhimurium infection reported to the CDC by means of thePublic Health Laboratory Information System has remained relativelyconstant over the past 15 years (excluding a large outbreakin 1985), the proportion of isolates with the five-drug patternof resistance has increased from less than 1 percent in 1979–1980to 34 percent in 1996. The great majority of these isolatesare probably DT104; since 1995, 91 percent of such isolatesthat were phage typed were identified as DT104 or as closelyrelated phage types included in the DT104 complex. Using datafrom these surveys, we estimate that of the 40,000 salmonellaisolates reported annually, 3400 are typhimurium with the five-drugpattern of resistance. Since previous studies have shown thatthe number of reported cases of salmonella infection representsonly 1 to 5 percent of the total number of cases,20 we estimatethat between 68,000 and 340,000 cases of infection with typhimuriumwith the five-drug pattern of resistance, most of which areprobably DT104, occur annually in the United States.
The sources of typhimurium DT104 with the five-drug patternof resistance remain to be determined. As early as 1985 andcoincident with its appearance in the United Kingdom, five-drug–resistanttyphimurium DT104 emerged in the United States, particularlyin western states. In contrast to the emergence of S. entericaserotype enteritidis,which was heralded by a dramatic increasein the number of related foodborne outbreaks,21 few outbreaksof typhimurium DT104 have been recognized in the United Statessince the first in 1996.22 In the United Kingdom, DT104 nowappears to be widely distributed in food animals, particularlycattle, and investigations have associated infections in humanswith eating pork sausages, chicken, and meat paste and withcontact with sick animals.12,23 Investigations in the UnitedStates have found associations between typhimurium DT104 infectionsin humans and the consumption of unpasteurized dairy productsand direct contact with livestock.24,25,26
The emergence of antimicrobial-drug resistance in salmonellaisolates is associated with the therapeutic and nontherapeuticuse of antimicrobial agents in food animals.27,28,29 In theface of the rapid emergence of DT104 and other resistant strainsof salmonella, in 1997 a World Health Organization group ofexperts reaffirmed recommendations to minimize the further emergenceof resistance to antimicrobial agents by, among other things,promoting the prudent use of antimicrobial agents in food animalsand ending the use as growth-promoting agents in food animalsof agents used in human medicine, such as penicillin and tetracycline,to which five-drug–resistant typhimuriumDT104 is resistant.30Although 14 percent of the five-drug–resistant typhimuriumDT104 isolates in the United Kingdom in 1996 were also resistantto ciprofloxacin,13 we did not identify any ciprofloxacin-resistantDT104 isolates in the United States. This difference may berelated to the fact that veterinary use of fluoroquinolones,approved in the United States in late 1995, is allowed onlyin poultry, and typhimurium DT104 might not yet be present inpoultry in the United States.
This study has some limitations. Data in the National AntimicrobialResistance Monitoring System and the periodic surveys of antimicrobial-drugresistance were collected from populations that may not be geographicallyrepresentative. Since these data were not, however, collectedspecifically for the study of typhimurium and since the isolatesforwarded to the CDC were randomly selected, any major biasis unlikely from this approach. Also, the appropriateness ofincluding multiple phage lysis patterns as a part of a largerDT104 complex and the epidemiologic importance of the DT104complex are not entirely clear.
Since data on clinical illness were not collected in the antimicrobialsurveys, there remains much to be learned about the spectrumof illness caused by typhimurium DT104. As with most salmonellainfections, treatment of these infections depends on the severityof illness. Antimicrobial-drug therapy is usually not essentialin cases of uncomplicated salmonella gastroenteritis; a fluoroquinolone,such as ciprofloxacin, or an extended-spectrum cephalosporin,such as ceftriaxone, remains the recommended treatment for invasivetyphimurium infections with the five-drug pattern of resistance.30
Typhimurium infections are common in the United States; it isthe second most commonly identified salmonella serotype andaccounted for 25 percent of culture-confirmed, serotyped casesof salmonella in 1996. Because typhimurium is common and fewlaboratories routinely subtype isolates, it is difficult todetect increases in specific strains. Continued and specificsurveillance, including a uniform method of subtyping isolates,is necessary to identify the extent to which DT104 might becontributing to the incidence of typhimurium infection in theUnited States. Currently used methods of subtyping typhimuriumisolates include phage typing, pulsed-field gel electrophoresis,and testing for susceptibility to antimicrobial agents; no onemethod, however, is capable of identifying five-drug–resistanttyphimurium DT104. Phage typing, which requires maintenanceof phage stocks and careful quality control, is available inonly a few public health laboratories in the world and providesno information about the antimicrobial-drug resistance of theorganism. The most common five-drug–resistant DT104 strainin the United States can be identified on the basis of its uniquepattern on pulsed-field gel electrophoresis, but other patternshave been reported, and the various patterns identified in differentlaboratories cannot be compared unless the technique has beencarefully standardized (Barrett T, CDC: personal communication).Testing for susceptibility to antimicrobial agents, particularlyscreening for resistance to chloramphenicol, appears to be agood screening procedure for identifying isolates with the five-drugpattern of resistance, but it is not routinely performed andmay not always be done according to the approved methods ofthe National Committee for Clinical Laboratory Standards.
Further epidemiologic studies are essential to devise a meansof preventing the transmission of five-drug–resistanttyphimurium DT104, a rapidly emerging pathogen in the UnitedStates. Until standardized laboratory procedures have been developed,state and local health departments and other interested personscan use resistance to chloramphenicol as a highly specific markerfor DT104 in order to prioritize the investigation of clustersof typhimurium infections. The sources of typhimurium with afive-drug pattern of resistance and the risk factors for infectionwith the organism must be identified, and the association betweenthe use of antimicrobial agents in food animals and the incidenceand continued emergence of these infections must be addressed.Prudent use of antimicrobial agents in farm animals and moreeffective disease prevention on farms are necessary to reducethe dissemination of five-drug–resistant typhimurium DT104and to slow the evolution of resistance to additional agentsin this and other strains of salmonella.
We are indebted to the participating local and state healthdepartments and public health laboratories in the Sentinel Countysurveys, the National Salmonella Antimicrobial Resistance Study,and the National Antimicrobial Resistance Monitoring System,and to Patricia Griffin, M.D., Laurence Slutsker, M.D., M.P.H.,Balasubr Swaminathan, Ph.D., and Robert Tauxe, M.D., M.P.H.,from the Foodborne and Diarrheal Diseases Branch, Division ofBacterial and Mycotic Diseases, National Center for InfectiousDiseases, Centers for Disease Control and Prevention, for theirassistance and comments in reviewing this article.
Source Information
From the Foodborne and Diarrheal Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta (M.K.G., C.B., W.D., M.M., F.J.A.), and the Food and Drug Administration, Rockville, Md. (P.D.).
Address reprint requests to Dr. Glynn at the Foodborne and Diarrheal Diseases Branch, Centers for Disease Control and Prevention, 1600 Clifton Rd., MS A-38, Atlanta, GA 30333.
References
Helmick CG, Griffin PM, Addiss DG, Tauxe RV, Juranek DD. Infectious diarrheas. In: Everhart JE, ed. Digestive diseases in the United States: epidemiology and impact. Washington, D.C.: Government Printing Office, 1994:85-123. (NIH publication no. 94-1447.)
Hargrett-Bean NT, Pavia AT, Tauxe RV. Salmonella isolates from humans in the United States, 1984-1986. Mor Mortal Wkly Rep CDC Surveill Summ 1988;37:25-31.
Tauxe RV. Salmonella: a postmodern pathogen. J Food Prot 1991;54:563-568.
Angulo FJ, Swerdlow DL. Bacterial enteric infections in persons infected with human immunodeficiency virus. Clin Infect Dis 1995;21:Suppl 1:S84-S93.
Blaser MJ, Feldman RA. Salmonella bacteremia: reports to the Centers for Disease Control, 1968-1979. J Infect Dis 1981;143:743-746. [Medline]
Black PH, Kunz LJ, Swartz MN. Salmonellosis -- a review of some unusual aspects. N Engl J Med 1960;262:864-70, 921. [Medline]
Celum CL, Chaisson RE, Rutherford GW, Barnhart JL, Echenberg DF. Incidence of salmonellosis in patients with AIDS. J Infect Dis 1987;156:998-1002. [Medline]
Lee LA, Puhr ND, Maloney EK, Bean NH, Tauxe RV. Increase in antimicrobial-resistant Salmonella infections in the United States, 1989-1990. J Infect Dis 1994;170:128-134. [Medline]
MacDonald KL, Cohen ML, Hargrett-Bean NT, et al. Changes in antimicrobial resistance of Salmonella isolated from humans in the United States. JAMA 1987;258:1496-1499. [Free Full Text]
Threlfall EJ, Rowe B, Ward LR. A comparison of multiple drug resistance in salmonellas from humans and food animals in England and Wales, 1981 and 1990. Epidemiol Infect 1993;111:189-197. [Medline]
Ramos JM, Ales JM, Cuenca-Estrella M, Fernandez-Roblas R, Soriano F. Changes in susceptibility of Salmonella enteritidis, Salmonella typhimurium, and Salmonella virchow to six antimicrobial agents in a Spanish hospital, 1980-1994. Eur J Clin Microbiol Infect Dis 1996;15:85-88. [CrossRef][Medline]
Wall PG, Morgan D, Lamden K, et al. A case control study of infection with an epidemic strain of multiresistant Salmonella typhimurium DT104 in England and Wales. Commun Dis Rep CDR Rev 1994;4:R130-R135. [Medline]
Threlfall EJ, Ward LR, Rowe B. Increasing incidence of resistance to trimethoprim and ciprofloxacin in epidemic Salmonella typhimurium DT 104 in England and Wales. Eurosurveillance 1997;2:81-4.
Bean NH, Martin SM, Brandford H Jr. PHLIS: an electronic system for reporting public health data from remote sites. Am J Public Health 1992;82:1273-1276. [Free Full Text]
Establishment of a national surveillance program for antimicrobial resistance in Salmonella. MMWR Morb Mortal Wkly Rep 1996;45:110-111. [Medline]
Anderson ES, Ward LR, de Saxe MJ, de Sa JD. Bacteriophage-typing designations of Salmonella typhimurium. J Hyg (Lond) 1977;78:297-300. [Medline]
Barry AL, Thornsberry C. Susceptibility tests: diffusion test procedures. In: Balows A, ed. Manual of clinical microbiology. 5th ed. Washington, D.C.: American Society for Microbiology, 1991:117-25.
Riley LW, Cohen ML, Seals JE, et al. Importance of host factors in human salmonellosis caused by multiresistant strains of Salmonella. J Infect Dis 1984;149:878-883. [Medline]
Salmonella surveillance: annual tabulation summary, 1993-1995. Atlanta: Centers for Disease Control and Prevention, 1996.
Chalker RB, Blaser MJ. A review of human salmonellosis. III. Magnitude of Salmonella infection in the United States. Rev Infect Dis 1988;10:111-124. [Medline]
Mishu B, Koehler J, Lee LA, et al. Outbreaks of Salmonella enteritidis infections in the United States, 1985-1991. J Infect Dis 1994;169:547-552. [Medline]
Fone DL, Barker RM. Associations between human and farm animal infections with Salmonella typhimurium DT104 in Herefordshire. Commun Dis Rep CDR Rev 1994;4:R136-R140. [Medline]
Besser TE, Gay CC, Gay JM, et al. Salmonellosis associated with S Typhimurium DT104 in the USA. Vet Rec 1997;140:75-75. [Medline]
Cody S, Abbott S, Marfin A, et al. Outbreaks of Salmonella Typhimurium var copenhagen DT104 and Salmonella Typhimurium DT104b linked to raw milk cheese. In: Program and abstracts of the 35th Annual Meeting of the Infectious Diseases Society of America, San Francisco, September 13–16, 1997. Alexandria, Va.: Infectious Diseases Society of America, 1997:77. abstract.
Friedman CR, Brady RC, Celotti MJ, et al. An outbreak of multidrug-resistant Salmonella serotype Typhimurium definitive type 104 (DT104) infections in humans and cattle in Vermont. In: Programs and abstracts of the International Conference on Emerging Infectious Diseases, Atlanta, March 8–11, 1998. Washington, D.C.: American Society of Microbiology, 1998:68. abstract.
Cohen ML, Tauxe RV. Drug-resistant Salmonella in the United States: an epidemiologic perspective. Science 1986;234:964-969. [Free Full Text]
Levy SB, FitzGerald GB, Macone AB. Changes in intestinal flora of farm personnel after introduction of a tetracycline-supplemented feed on a farm. N Engl J Med 1976;295:583-588. [Abstract]
O'Brien TF, Hopkins JD, Gilleece ES, et al. Molecular epidemiology of antibiotic resistance in salmonella from animals and human beings in the United States. N Engl J Med 1982;307:1-6. [Abstract]
Division of Emerging and Other Communicable Disease Surveillance and Control. The medical impact of the use of antimicrobials in food animals: report of a WHO meeting, Berlin, Germany, 13–17 October 1997. Geneva: World Health Organization, 1997. (Document no. WHO/EMC/ZOO/97.4.)
Uchida, I., Ishihara, R., Tanaka, K., Hata, E., Makino, S.-i., Kanno, T., Hatama, S., Kishima, M., Akiba, M., Watanabe, A., Kubota, T.
(2009). Salmonella enterica serotype Typhimurium DT104 ArtA-dependent modification of pertussis toxin-sensitive G proteins in the presence of [32P]NAD. Microbiology
155: 3710-3718
[Abstract][Full Text]
Lindsey, R. L., Fedorka-Cray, P. J., Frye, J. G., Meinersmann, R. J.
(2009). Inc A/C Plasmids Are Prevalent in Multidrug-Resistant Salmonella enterica Isolates. Appl. Environ. Microbiol.
75: 1908-1915
[Abstract][Full Text]
Khan, A. A., Ponce, E., Nawaz, M. S., Cheng, C.-M., Khan, J. A., West, C. S.
(2009). Identification and Characterization of Class 1 Integron Resistance Gene Cassettes among Salmonella Strains Isolated from Imported Seafood. Appl. Environ. Microbiol.
75: 1192-1196
[Abstract][Full Text]
Martins, S. A. R., Combs, J. C., Noguera, G., Camacho, W., Wittmann, P., Walther, R., Cano, M., Dick, J., Behrens, A.
(2008). Antimicrobial Efficacy of Riboflavin/UVA Combination (365 nm) In Vitro for Bacterial and Fungal Isolates: A Potential New Treatment for Infectious Keratitis. IOVS
49: 3402-3408
[Abstract][Full Text]
Foley, S. L., Lynne, A. M., Nayak, R.
(2008). Salmonella challenges: Prevalence in swine and poultry and potential pathogenicity of such isolates. J ANIM SCI
86: E149-E162
[Abstract][Full Text]
Eswarappa, S. M., Panguluri, K. K., Hensel, M., Chakravortty, D.
(2008). The yejABEF operon of Salmonella confers resistance to antimicrobial peptides and contributes to its virulence. Microbiology
154: 666-678
[Abstract][Full Text]
Buchanan, N. P., Hott, J. M., Cutlip, S. E., Rack, A. L., Asamer, A., Moritz, J. S.
(2008). The Effects of a Natural Antibiotic Alternative and a Natural Growth Promoter Feed Additive on Broiler Performance and Carcass Quality. J. Appl. Poult. Res.
17: 202-210
[Abstract][Full Text]
Nishino, K., Nikaido, E., Yamaguchi, A.
(2007). Regulation of Multidrug Efflux Systems Involved in Multidrug and Metal Resistance of Salmonella enterica Serovar Typhimurium. J. Bacteriol.
189: 9066-9075
[Abstract][Full Text]
Chen, S., Cui, S., McDermott, P. F., Zhao, S., White, D. G., Paulsen, I., Meng, J.
(2007). Contribution of Target Gene Mutations and Efflux to Decreased Susceptibility of Salmonella enterica Serovar Typhimurium to Fluoroquinolones and Other Antimicrobials. Antimicrob. Agents Chemother.
51: 535-542
[Abstract][Full Text]
Khan, A. A., Cheng, C.-M., Van, K. T., West, C. S., Nawaz, M. S., Khan, S. A.
(2006). Characterization of class 1 integron resistance gene cassettes in Salmonella enterica serovars Oslo and Bareily from imported seafood. J Antimicrob Chemother
58: 1308-1310
[Full Text]
Adkins, J. N., Mottaz, H. M., Norbeck, A. D., Gustin, J. K., Rue, J., Clauss, T. R. W., Purvine, S. O., Rodland, K. D., Heffron, F., Smith, R. D.
(2006). Analysis of the Salmonella typhimurium Proteome through Environmental Response toward Infectious Conditions. Mol. Cell. Proteomics
5: 1450-1461
[Abstract][Full Text]
Hermans, A. P. H. M., Beuling, A. M., van Hoek, A. H. A. M., Aarts, H. J. M., Abee, T., Zwietering, M. H.
(2006). Distribution of prophages and SGI-1 antibiotic-resistance genes among different Salmonella enterica serovar Typhimurium isolates. Microbiology
152: 2137-2147
[Abstract][Full Text]
Takaya, A., Watanabe, M., Yamamoto, T.
(2006). Organization of tn2610 containing two transposition modules.. Antimicrob. Agents Chemother.
50: 1143-1147
[Abstract][Full Text]
Hu, H., Lan, R., Reeves, P. R.
(2006). Adaptation of Multilocus Sequencing for Studying Variation Within a Major Clone: Evolutionary Relationships of Salmonella enterica Serovar Typhimurium. Genetics
172: 743-750
[Abstract][Full Text]
Izumiya, H., Mori, K., Kurazono, T., Yamaguchi, M., Higashide, M., Konishi, N., Kai, A., Morita, K., Terajima, J., Watanabe, H.
(2005). Characterization of Isolates of Salmonella enterica Serovar Typhimurium Displaying High-Level Fluoroquinolone Resistance in Japan. J. Clin. Microbiol.
43: 5074-5079
[Abstract][Full Text]
Hermans, A. P. H. M., Abee, T., Zwietering, M. H., Aarts, H. J. M.
(2005). Identification of Novel Salmonella enterica Serovar Typhimurium DT104-Specific Prophage and Nonprophage Chromosomal Sequences among Serovar Typhimurium Isolates by Genomic Subtractive Hybridization. Appl. Environ. Microbiol.
71: 4979-4985
[Abstract][Full Text]
Saitoh, M., Tanaka, K., Nishimori, K., Makino, S.-i., Kanno, T., Ishihara, R., Hatama, S., Kitano, R., Kishima, M., Sameshima, T., Akiba, M., Nakazawa, M., Yokomizo, Y., Uchida, I.
(2005). The artAB genes encode a putative ADP-ribosyltransferase toxin homologue associated with Salmonella enterica serovar Typhimurium DT104. Microbiology
151: 3089-3096
[Abstract][Full Text]
Hsu, R.-B., Lin, F.-Y., Chen, R. J., Hsueh, P.-R., Wang, S.-S.
(2005). Antimicrobial Drug Resistance in Salmonella-Infected Aortic Aneurysms. Ann. Thorac. Surg.
80: 530-536
[Abstract][Full Text]
Cui, S., Ge, B., Zheng, J., Meng, J.
(2005). Prevalence and Antimicrobial Resistance of Campylobacter spp. and Salmonella Serovars in Organic Chickens from Maryland Retail Stores. Appl. Environ. Microbiol.
71: 4108-4111
[Abstract][Full Text]
Ahmed, A. M., Nakano, H., Shimamoto, T.
(2005). Molecular characterization of integrons in non-typhoid Salmonella serovars isolated in Japan: description of an unusual class 2 integron. J Antimicrob Chemother
55: 371-374
[Abstract][Full Text]
Baucheron, S., Tyler, S., Boyd, D., Mulvey, M. R., Chaslus-Dancla, E., Cloeckaert, A.
(2004). AcrAB-TolC Directs Efflux-Mediated Multidrug Resistance in Salmonella enterica Serovar Typhimurium DT104. Antimicrob. Agents Chemother.
48: 3729-3735
[Abstract][Full Text]
Doublet, B., Weill, F.-X., Fabre, L., Chaslus-Dancla, E., Cloeckaert, A.
(2004). Variant Salmonella Genomic Island 1 Antibiotic Resistance Gene Cluster Containing a Novel 3'-N-Aminoglycoside Acetyltransferase Gene Cassette, aac(3)-Id, in Salmonella enterica Serovar Newport. Antimicrob. Agents Chemother.
48: 3806-3812
[Abstract][Full Text]
Shea, K. M., Committee on Environmental Health, , Committee on Infectious Diseases,
(2004). Nontherapeutic Use of Antimicrobial Agents in Animal Agriculture: Implications for Pediatrics. Pediatrics
114: 862-868
[Abstract][Full Text]
Doublet, B., Butaye, P., Imberechts, H., Boyd, D., Mulvey, M. R., Chaslus-Dancla, E., Cloeckaert, A.
(2004). Salmonella Genomic Island 1 Multidrug Resistance Gene Clusters in Salmonella enterica Serovar Agona Isolated in Belgium in 1992 to 2002. Antimicrob. Agents Chemother.
48: 2510-2517
[Abstract][Full Text]
Chiller, T. M., Barrett, T., Angulo, F. J.
(2004). CDC studies incorrectly summarized in 'critical review'. J Antimicrob Chemother
54: 275-276
[Full Text]
Hossain, A., Reisbig, M. D., Hanson, N. D.
(2004). Plasmid-encoded functions compensate for the biological cost of AmpC overexpression in a clinical isolate of Salmonella typhimurium. J Antimicrob Chemother
53: 964-970
[Abstract][Full Text]
Gorman, R., Adley, C. C.
(2004). Characterization of Salmonella enterica Serotype Typhimurium Isolates from Human, Food, and Animal Sources in the Republic of Ireland. J. Clin. Microbiol.
42: 2314-2316
[Abstract][Full Text]
Tanaka, K., Nishimori, K., Makino, S.-I., Nishimori, T., Kanno, T., Ishihara, R., Sameshima, T., Akiba, M., Nakazawa, M., Yokomizo, Y., Uchida, I.
(2004). Molecular Characterization of a Prophage of Salmonella enterica Serotype Typhimurium DT104. J. Clin. Microbiol.
42: 1807-1812
[Abstract][Full Text]
Chen, S., Zhao, S., White, D. G., Schroeder, C. M., Lu, R., Yang, H., McDermott, P. F., Ayers, S., Meng, J.
(2004). Characterization of Multiple-Antimicrobial-Resistant Salmonella Serovars Isolated from Retail Meats. Appl. Environ. Microbiol.
70: 1-7
[Abstract][Full Text]
Phillips, I., Casewell, M., Cox, T., De Groot, B., Friis, C., Jones, R., Nightingale, C., Preston, R., Waddell, J.
(2004). Does the use of antibiotics in food animals pose a risk to human health? A critical review of published data. J Antimicrob Chemother
53: 28-52
[Abstract][Full Text]
Zhao, S., Qaiyumi, S., Friedman, S., Singh, R., Foley, S. L., White, D. G., McDermott, P. F., Donkar, T., Bolin, C., Munro, S., Baron, E. J., Walker, R. D.
(2003). Characterization of Salmonella enterica Serotype Newport Isolated from Humans and Food Animals. J. Clin. Microbiol.
41: 5366-5371
[Abstract][Full Text]
White, D. G., Datta, A., McDermott, P., Friedman, S., Qaiyumi, S., Ayers, S., English, L., McDermott, S., Wagner, D. D., Zhao, S.
(2003). Antimicrobial susceptibility and genetic relatedness of Salmonella serovars isolated from animal-derived dog treats in the USA. J Antimicrob Chemother
52: 860-863
[Abstract][Full Text]
Meyerholz, D. K., Stabel, T. J.
(2003). Comparison of Early Ileal Invasion by Salmonella enterica Serovars Choleraesuis and Typhimurium. Vet Pathol
40: 371-375
[Abstract][Full Text]
Shea, K. M.
(2003). Antibiotic Resistance: What Is the Impact of Agricultural Uses of Antibiotics on Children's Health?. Pediatrics
112: 253-258
[Abstract][Full Text]
Lindstedt, B.-A., Heir, E., Gjernes, E., Kapperud, G.
(2003). DNA Fingerprinting of Salmonella enterica subsp. enterica Serovar Typhimurium with Emphasis on Phage Type DT104 Based on Variable Number of Tandem Repeat Loci. J. Clin. Microbiol.
41: 1469-1479
[Abstract][Full Text]
Bettelheim, K. A., Hornitzky, M. A., Djordjevic, S. P., Kuzevski, A.
(2003). Antibiotic resistance among verocytotoxigenic Escherichia coli (VTEC) and non-VTEC isolated from domestic animals and humans. J Med Microbiol
52: 155-162
[Abstract][Full Text]
Orman, B. E., Pineiro, S. A., Arduino, S., Galas, M., Melano, R., Caffer, M. I., Sordelli, D. O., Centron, D.
(2002). Evolution of Multiresistance in Nontyphoid Salmonella Serovars from 1984 to 1998 in Argentina. Antimicrob. Agents Chemother.
46: 3963-3970
[Abstract][Full Text]
Carattoli, A., Filetici, E., Villa, L., Dionisi, A. M., Ricci, A., Luzzi, I.
(2002). Antibiotic Resistance Genes and Salmonella Genomic Island 1 in Salmonella enterica Serovar Typhimurium Isolated in Italy. Antimicrob. Agents Chemother.
46: 2821-2828
[Abstract][Full Text]
Guerra, B., Soto, S., Helmuth, R., Mendoza, M. C.
(2002). Characterization of a Self-Transferable Plasmid from Salmonella enterica Serotype Typhimurium Clinical Isolates Carrying Two Integron-Borne Gene Cassettes Together with Virulence and Drug Resistance Genes. Antimicrob. Agents Chemother.
46: 2977-2981
[Abstract][Full Text]
Weinberg, G. A.
(2002). Question From the Clinician: Phages in Infections. Pediatr. Rev.
23: 329-330
[Full Text]
Gebreyes, W. A., Altier, C.
(2002). Molecular Characterization of Multidrug-Resistant Salmonella enterica subsp. enterica Serovar Typhimurium Isolates from Swine. J. Clin. Microbiol.
40: 2813-2822
[Abstract][Full Text]
Boyd, D., Cloeckaert, A., Chaslus-Dancla, E., Mulvey, M. R.
(2002). Characterization of Variant Salmonella Genomic Island 1 Multidrug Resistance Regions from Serovars Typhimurium DT104 and Agona. Antimicrob. Agents Chemother.
46: 1714-1722
[Abstract][Full Text]
Westwater, C., Schofield, D. A., Schmidt, M. G., Norris, J. S., Dolan, J. W.
(2002). Development of a P1 phagemid system for the delivery of DNA into Gram-negative bacteria. Microbiology
148: 943-950
[Abstract][Full Text]
Barber, D., Miller, G., McNamara, P., Sundberg, P., Vogel, L. P., Blackman, B. T., White, D. G., McDermott, P. F., Meng, J., McDonald, L. C., Sorensen, T. L., Wegener, H. C., Frimodt-Moller, N.
(2002). Resistant Bacteria in Retail Meats and Antimicrobial Use in Animals. NEJM
346: 777-779
[Full Text]
White, D. G., Zhao, S., Sudler, R., Ayers, S., Friedman, S., Chen, S., McDermott, P. F., McDermott, S., Wagner, D. D., Meng, J.
(2001). The Isolation of Antibiotic-Resistant Salmonella from Retail Ground Meats. NEJM
345: 1147-1154
[Abstract][Full Text]
Hanes, D. E., Robl, M. G., Schneider, C. M., Burr, D. H.
(2001). New Zealand White Rabbit as a Nonsurgical Experimental Model for Salmonella enterica Gastroenteritis. Infect. Immun.
69: 6523-6526
[Abstract][Full Text]
Boyd, D., Peters, G. A., Cloeckaert, A., Boumedine, K. S., Chaslus-Dancla, E., Imberechts, H., Mulvey, M. R.
(2001). Complete Nucleotide Sequence of a 43-Kilobase Genomic Island Associated with the Multidrug Resistance Region of Salmonella enterica Serovar Typhimurium DT104 and Its Identification in Phage Type DT120 and Serovar Agona. J. Bacteriol.
183: 5725-5732
[Abstract][Full Text]
Izumiya, H., Terajima, J., Matsushita, S., Tamura, K., Watanabe, H.
(2001). Characterization of Multidrug-Resistant Salmonella enterica Serovar Typhimurium Isolated in Japan. J. Clin. Microbiol.
39: 2700-2703
[Abstract][Full Text]
Guerra, B., Soto, S. M., Argüelles, J. M., Mendoza, M. C.
(2001). Multidrug Resistance Is Mediated by Large Plasmids Carrying a Class 1 Integron in the Emergent Salmonella enterica Serotype [4,5,12:i:{-}]. Antimicrob. Agents Chemother.
45: 1305-1308
[Abstract][Full Text]
Tamada, Y., Nakaoka, Y., Nishimori, K., Doi, A., Kumaki, T., Uemura, N., Tanaka, K., Makino, S.-I., Sameshima, T., Akiba, M., Nakazawa, M., Uchida, I.
(2001). Molecular Typing and Epidemiological Study of Salmonella enterica Serotype Typhimurium Isolates from Cattle by Fluorescent Amplified-Fragment Length Polymorphism Fingerprinting and Pulsed-Field Gel Electrophoresis. J. Clin. Microbiol.
39: 1057-1066
[Abstract][Full Text]
Koutsolioutsou, A., Martins, E. A., White, D. G., Levy, S. B., Demple, B.
(2001). A soxRS-Constitutive Mutation Contributing to Antibiotic Resistance in a Clinical Isolate of Salmonella enterica (Serovar Typhimurium). Antimicrob. Agents Chemother.
45: 38-43
[Abstract][Full Text]
Dunne, E. F., Fey, P. D., Kludt, P., Reporter, R., Mostashari, F., Shillam, P., Wicklund, J., Miller, C., Holland, B., Stamey, K., Barrett, T. J., Rasheed, J. K., Tenover, F. C., Ribot, E. M., Angulo, F. J.
(2000). Emergence of Domestically Acquired Ceftriaxone-Resistant Salmonella Infections Associated With AmpC {beta}-Lactamase. JAMA
284: 3151-3156
[Abstract][Full Text]
Daly, M., Fanning, S.
(2000). Characterization and Chromosomal Mapping of Antimicrobial Resistance Genes in Salmonella enterica Serotype Typhimurium. Appl. Environ. Microbiol.
66: 4842-4848
[Abstract][Full Text]
Mattick, K. L., Jørgensen, F., Legan, J. D., Lappin-Scott, H. M., Humphrey, T. J.
(2000). Habituation of Salmonella spp. at Reduced Water Activity and Its Effect on Heat Tolerance. Appl. Environ. Microbiol.
66: 4921-4925
[Abstract][Full Text]
Winokur, P. L., Brueggemann, A., DeSalvo, D. L., Hoffmann, L., Apley, M. D., Uhlenhopp, E. K., Pfaller, M. A., Doern, G. V.
(2000). Animal and Human Multidrug-Resistant, Cephalosporin-Resistant Salmonella Isolates Expressing a Plasmid-Mediated CMY-2 AmpC beta -Lactamase. Antimicrob. Agents Chemother.
44: 2777-2783
[Abstract][Full Text]
White, D. G., Piddock, L. J. V., Maurer, J. J., Zhao, S., Ricci, V., Thayer, S. G.
(2000). Characterization of Fluoroquinolone Resistance among Veterinary Isolates of Avian Escherichia coli. Antimicrob. Agents Chemother.
44: 2897-2899
[Abstract][Full Text]
Pritchett, L. C., Konkel, M. E., Gay, J. M., Besser, T. E.
(2000). Identification of DT104 and U302 Phage Types among Salmonella enterica Serotype Typhimurium Isolates by PCR. J. Clin. Microbiol.
38: 3484-3488
[Abstract][Full Text]
Guerra, B., Soto, S., Cal, S., Mendoza, M. C.
(2000). Antimicrobial Resistance and Spread of Class 1 Integrons among Salmonella Serotypes. Antimicrob. Agents Chemother.
44: 2166-2169
[Abstract][Full Text]
Threlfall, E. J.
(2000). Epidemic Salmonella typhimurium DT 104--a truly international multiresistant clone. J Antimicrob Chemother
46: 7-10
[Full Text]
Tsolis, R. M., Adams, L. G., Hantman, M. J., Scherer, C. A., Kimbrough, T., Kingsley, R. A., Ficht, T. A., Miller, S. I., Baumler, A. J.
(2000). SspA Is Required for Lethal Salmonella enterica Serovar Typhimurium Infections in Calves but Is Not Essential for Diarrhea. Infect. Immun.
68: 3158-3163
[Abstract][Full Text]
Prats, G., Mirelis, B., Llovet, T., Muñoz, C., Miró, E., Navarro, F.
(2000). Antibiotic Resistance Trends in Enteropathogenic Bacteria Isolated in 1985-1987 and 1995-1998 in Barcelona. Antimicrob. Agents Chemother.
44: 1140-1145
[Abstract][Full Text]
Cloeckaert, A., Sidi Boumedine, K., Flaujac, G., Imberechts, H., D'Hooghe, I., Chaslus-Dancla, E.
(2000). 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.
44: 1359-1361
[Abstract][Full Text]
Mattick, K. L., Jørgensen, F., Legan, J. D., Cole, M. B., Porter, J., Lappin-Scott, H. M., Humphrey, T. J.
(2000). Survival and Filamentation of Salmonella enterica Serovar Enteritidis PT4 and Salmonella enterica Serovar Typhimurium DT104 at Low Water Activity. Appl. Environ. Microbiol.
66: 1274-1279
[Abstract][Full Text]
Markogiannakis, A., Tassios, P. T., Lambiri, M., Ward, L. R., Kourea-Kremastinou, J., Legakis, N. J., The Greek Nontyphoidal Salmonella Study Group, , Vatopoulos, A. C.
(2000). Multiple Clones within Multidrug-Resistant Salmonella enterica Serotype Typhimurium Phage Type DT104. J. Clin. Microbiol.
38: 1269-1271
[Abstract][Full Text]
Daly, M., Buckley, J., Power, E., O'Hare, C., Cormican, M., Cryan, B., Wall, P. G., Fanning, S.
(2000). Molecular Characterization of Irish Salmonella enterica Serotype Typhimurium: Detection of Class I Integrons and Assessment of Genetic Relationships by DNA Amplification Fingerprinting. Appl. Environ. Microbiol.
66: 614-619
[Abstract][Full Text]
ARCANGIOLI, M.-A., LEROY-SETRIN, S., MARTEL, J.-L., CHASLUS-DANCLA, E.
(2000). Evolution of chloramphenicol resistance, with emergence of cross-resistance to florfenicol, in bovine Salmonella Typhimurium strains implicates definitive phage type (DT) 104. J Med Microbiol
49: 103-110
[Abstract][Full Text]
Ng, L.-K., Mulvey, M. R., Martin, I., Peters, G. A., Johnson, W.
(1999). Genetic Characterization of Antimicrobial Resistance in Canadian Isolates of Salmonella Serovar Typhimurium DT104. Antimicrob. Agents Chemother.
43: 3018-3021
[Abstract][Full Text]
Abbott, S. L., Portoni, B. A., Janda, J. M.
(1999). Urinary Tract Infections Associated with Nontyphoidal Salmonella Serogroups. J. Clin. Microbiol.
37: 4177-4178
[Abstract][Full Text]
Molbak, K., Baggesen, D. L., Aarestrup, F. M., Ebbesen, J. M., Engberg, J., Frydendahl, K., Gerner-Smidt, P., Petersen, A. M., Wegener, H. C.
(1999). An Outbreak of Multidrug-Resistant, Quinolone-Resistant Salmonella enterica Serotype Typhimurium DT104. NEJM
341: 1420-1425
[Abstract][Full Text]
Tassios, P. T., Gazouli, M., Tzelepi, E., Milch, H., Kozlova, N., Sidorenko, S., Legakis, N. J., Tzouvelekis, L. S.
(1999). Spread of a Salmonella typhimurium Clone Resistant to Expanded-Spectrum Cephalosporins in Three European Countries. J. Clin. Microbiol.
37: 3774-3777
[Abstract][Full Text]
Llanes, C., Kirchgesner, V., Plesiat, P.
(1999). Propagation of TEM- and PSE-Type beta -Lactamases among Amoxicillin-Resistant Salmonella spp. Isolated in France. Antimicrob. Agents Chemother.
43: 2430-2436
[Abstract][Full Text]
Sanders, T A B
(1999). Food production and food safety. BMJ
318: 1689-1693
[Full Text]
Smith, K. E., Besser, J. M., Hedberg, C. W., Leano, F. T., Bender, J. B., Wicklund, J. H., Johnson, B. P., Moore, K. A., Osterholm, M. T., The Investigation Team,
(1999). Quinolone-Resistant Campylobacter jejuni Infections in Minnesota, 1992-1998. NEJM
340: 1525-1532
[Abstract][Full Text]
Wegener, H. C.
(1999). The Consequences for Food Safety of the Use of Fluoroquinolones in Food Animals. NEJM
340: 1581-1582
[Full Text]
Cody, S. H., Abbott, S. L., Marfin, A. A., Schulz, B., Wagner, P., Robbins, K., Mohle-Boetani, J. C., Vugia, D. J.
(1999). Two Outbreaks of Multidrug-Resistant Salmonella Serotype Typhimurium DT104 Infections Linked to Raw-Milk Cheese in Northern California. JAMA
281: 1805-1810
[Abstract][Full Text]
Villar, R. G., Macek, M. D., Simons, S., Hayes, P. S., Goldoft, M. J., Lewis, J. H., Rowan, L. L., Hursh, D., Patnode, M., Mead, P. S.
(1999). Investigation of Multidrug-Resistant Salmonella Serotype Typhimurium DT104 Infections Linked to Raw-Milk Cheese in Washington State. JAMA
281: 1811-1816
[Abstract][Full Text]
Keene, W. E.
(1999). Lessons From Investigations of Foodborne Disease Outbreaks. JAMA
281: 1845-1847
[Full Text]
Poirel, L., Guibert, M., Bellais, S., Naas, T., Nordmann, P.
(1999). Integron- and Carbenicillinase-Mediated Reduced Susceptibility to Amoxicillin-Clavulanic Acid in Isolates of Multidrug-Resistant Salmonella enterica Serotype Typhimurium DT104 from French Patients. Antimicrob. Agents Chemother.
43: 1098-1104
[Abstract][Full Text]
Bolton, L. F., Kelley, L. C., Lee, M. D., Fedorka-Cray, P. J., Maurer, J. J.
(1999). Detection of Multidrug-Resistant Salmonella enterica Serotype typhimurium DT104 Based on a Gene Which Confers Cross-Resistance to Florfenicol and Chloramphenicol. J. Clin. Microbiol.
37: 1348-1351
[Abstract][Full Text]
Briggs, C. E., Fratamico, P. M.
(1999). Molecular Characterization of an Antibiotic Resistance Gene Cluster of Salmonella typhimurium DT104. Antimicrob. Agents Chemother.
43: 846-849
[Abstract][Full Text]
Schutze, G. E., Sikes, J. D., Stefanova, R., Cave, M. D.
(1999). The Home Environment and Salmonellosis in Children. Pediatrics
103: e1-1
[Abstract][Full Text]
Carattoli, A., Tosini, F., Visca, P., Glynn, M. K., Ribot, E. M., Barrett, T. J.
(1998). Multidrug-Resistant Salmonella enterica Serotype Typhimurium Infections. NEJM
339: 921-922
[Full Text]
Goossens, H., Sprenger, M. J W
(1998). Community acquired infections and bacterial resistance. BMJ
317: 654-657
[Full Text]
(1998). Multidrug-Resistant Salmonella on the Rise. JWatch Emergency Med.
1998: 1-1
[Full Text]
(1998). More Bad News -- Increased Prevalence of Multidrug-Resistant S. enterica in the U.S.. JWatch Infect. Diseases
1998: 9-9
[Full Text]
(1998). Antibiotic Resistance Mounts in Salmonella. JWatch General
1998: 1-1
[Full Text]
Levy, S. B.
(1998). Multidrug Resistance -- A Sign of the Times. NEJM
338: 1376-1378
[Full Text]
