Phenotypic and molecular characterization of TEM-116 extended-spectrum beta-lactamase produced by a Shigella flexneri clinical isolate from chickens.
Extended-spectrum beta-lactamases (ESBLs) produced by a clinical isolate of Shigella flexneri from chickens were detected with confirmatory phenotypic tests of the Clinical and Laboratory Standards Institute, and minimum inhibitory concentrations of several antibacterial drugs against the isolate were determined by the twofold dilution method. The genotype and subtype of the ESBL-producing S. flexneri isolate were identified by PCR amplifying of ESBL genes and DNA sequencing analysis. The results revealed that the isolate was able to produce ESBLs. They were resistant to third-generation cephalosporins such as ceftiofur and ceftriaxone and showed characteristics of multidrug resistance. The ESBL gene from the S. flexneri isolate was of the TEM type. Sequence analysis indicated that the TEM-type gene had 99.1% and 99.2% identity to TEM-1D ESBL and TEM-1 beta-lactamase, respectively, at the nucleotide level. The amino acid sequence inferred from the TEM-type gene revealed three substitutions compared with the TEM-1 and TEM-1D enzymes: Ser51Gly, Val82Ila and Ala182Val. When it was compared with TEM-116 (99.8% identity), there were only two mutations (A(151)G and T(403)C) in the TEM-type gene, resulting in the substitution of Ser to Gly at position 51 in the amino acid sequence. The TEM type was a TEM-116 derivative.
Hu
Gong-Zheng
GZ
Department of Pharmacology and Toxicology, College of Animal Husbandry and Veterinary Science, Henan Agricultural University, Zhengzhou, China. yaolilab@163.com
Chen
Hong-Ying
HY
Si
Hong-Bin
HB
Deng
Li-Xin
LX
Wei
Zhan-Yong
ZY
Yuan
Li
L
Kuang
Xiu-Hua
XH
D019943:Amino Acid Substitution; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002645:Chickens; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D004405:Dysentery, Bacillary / Q000382:microbiology* / Q000662:veterinary*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011201:Poultry Diseases / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012763:Shigella flexneri / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D001618:beta-Lactamases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases