Insertion sequence ISEcp1-like element connected with a novel aph(2'') allele [aph(2'')-Ie] conferring high-level gentamicin resistance and a novel streptomycin adenylyltransferase gene in Enterococcus.
Enterococcus casseliflavus HZ95 is an enterococcus with high-level resistance to aminoglycosides. Nine genes responsible for high-level aminoglycoside resistance, including aac(6')-Ie-aph(2'')-Ia, aph(2'')-Ib, aph(2'')-Ic, aph(2'')-Id, aph(3')-IIIa, aac(6')-Ii, ant(3')-Ia, ant(4')-Ia and ant(6')-Ia, were not detected in HZ95. An 8 kb fragment from unconjugative plasmids of HZ95 was cloned, and expressed gentamicin resistance in Escherichia coli DH5alpha. The genetic structures ( approximately 8 kb DNA fragment) containing these aminoglycoside-modifying enzyme genes in Ent. casseliflavus HZ95 were determined. The deduced amino acid sequence of the novel aph(2'') allele, aph(2'')-Ie, had 93.7 % amino acid identity with APH(2'')-Id. The aph(2'')-Ie gene was bracketed upstream by an insertion sequence (IS)Ecp1-like element and downstream by a streptomycin adenylyltransferase gene (str). The streptomycin adenylyltransferase encoded by the str gene had 80.3 % amino acid identity with the protein encoded by aadE. The plasmid of approximately 16 kb could hybridize with a PCR-generated aph(2'')-Ie intragenic probe. The ISEcp1-like element had 91 % identity with ISEcp1. ISEcp1, which commonly acts as a key factor in the dissemination of CTX-M-type beta-lactamase genes in Gram-negative bacteria, has not been reported in Enterococcus.
Chen
Ya-Gang
YG
Infectious Disease Department, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Qu
Ting-Ting
TT
Infectious Disease Department, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Yu
Yun-Song
YS
Infectious Disease Department, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Zhou
Jian-Ying
JY
Infectious Disease Department, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
Li
Lan-Juan
LJ
Infectious Disease Department, The First Affiliated Hospital, Medical School, Zhejiang University, The Key Laboratory of Infectious Diseases of Public Health Ministry, Zhejiang, Hangzhou, China.
D000483:Alleles; D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D003428:Cross Infection / Q000382:microbiology; D004251:DNA Transposable Elements / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016983:Enterococcus / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics*; D005839:Gentamicins / Q000494:pharmacology*; D006801:Humans; D008969:Molecular Sequence Data; D009713:Nucleotidyltransferases / Q000737:chemistry / Q000235:genetics*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics*; D016133:Polymerase Chain Reaction; D013290:Streptococcal Infections / Q000382:microbiology
D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D005839:Gentamicins; D017853:Phosphotransferases (Alcohol Group Acceptor); C048564:aminoglycoside 2''-phosphotransferase; D009713:Nucleotidyltransferases; C022678:streptomycin 3''-adenylyltransferase