title: Detection and characterization of extended-spectrum beta-lactamase (TEM-52)-producing Salmonella serotype Infantis from broilers in Japan.
abstract: During 2004 and 2006, multidrug-resistant Salmonella enterica subspecies enterica serovar Infantis (Salmonella Infantis) isolates (n = 120) were recovered from broiler cecal samples collected from a meat-processing plant, and the isolates were examined. The study was conducted to detect and characterize extended-spectrum beta-lactamase (ESBL)-producing Salmonella Infantis isolates recovered from broiler chickens and determine the mechanisms of transfer of the resistance traits. Extended-spectrum cephalosporins-resistant Salmonella Infantis isolates producing ESBL TEM-52 were detected. The mutant bla(TEM-52) gene and the wild-type bla(TEM-1) gene that mediated resistance to ampicillin (an extended-spectrum penicillin) and cephalothin (a narrow-spectrum cephalosporin) were located on approximately 50-kb conjugative plasmids among beta-lactam-resistant (n = 29) isolates. The bla(TEM) genes did not cotransfer with aadA1, sul1 (both associated with class 1 integrons), tetA, and dfrA5, signifying a chromosomal location of these non-beta-lactam resistance-encoding genes. This is the first report describing TEM-52-producing S. enterica from food-producing animals in Japan. An emergence of TEM-type ESBL is an important concern to public health because this readily transferable resistance mechanism threatens the value of the third-generation cephalosporins and may reduce the clinical utility of this class of antibiotics against pathogenic Gram-negative bacteria.
authors.affiliation: Department of Veterinary Medicine, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.
authors.forename: Francis
authors.initials: F
authors.lastname: Shahada
authors.forename: Takehisa
authors.initials: T
authors.lastname: Chuma
authors.forename: Hesham
authors.initials: H
authors.lastname: Dahshan
authors.forename: Masato
authors.initials: M
authors.lastname: Akiba
authors.forename: Masuo
authors.initials: M
authors.lastname: Sueyoshi
authors.forename: Karoku
authors.initials: K
authors.lastname: Okamoto
mesh_terms: D000668:Ampicillin Resistance / Q000235:genetics; D000818:Animals; D002432:Cecum / Q000382:microbiology; D018550:Cephalosporin Resistance / Q000235:genetics; D002645:Chickens / Q000382:microbiology*; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D004357:Drug Synergism; D005516:Food Microbiology; D022761:Gene Transfer, Horizontal; D005838:Genotype; D032023:Integrons / Q000235:genetics; D007564:Japan; D008826:Microbial Sensitivity Tests; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D019779:Salmonella enterica / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D012703:Serotyping; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
chemical_list: C445691:TEM-52 beta-lactamase; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1