A new subclass of intrinsic aminoglycoside nucleotidyltransferases, ANT(3")-II, is horizontally transferred among Acinetobacter spp. by homologous recombination.
The emergence and spread of antibiotic resistance among Acinetobacter spp. have been investigated extensively. Most studies focused on the multiple antibiotic resistance genes located on plasmids or genomic resistance islands. On the other hand, the mechanisms controlling intrinsic resistance are still not well understood. In this study, we identified the novel subclass of aminoglycoside nucleotidyltransferase ANT(3")-II in Acinetobacter spp., which comprised numerous variants distributed among three main clades. All members of this subclass can inactivate streptomycin and spectinomycin. The three ant(3")-II genes, encoding for the three ANT(3")-II clades, are widely distributed in the genus Acinetobacter and always located in the same conserved genomic region. According to their prevalence, these genes are intrinsic in Acinetobacter baumannii, Acinetobacter pittii, and Acinetobacter gyllenbergii. We also demonstrated that the ant(3")-II genes are located in a homologous recombination hotspot and were recurrently transferred among Acinetobacter species. In conclusion, our findings demonstrated a novel mechanism of natural resistance in Acinetobacter spp., identified a novel subclass of aminoglycoside nucleotidyltransferase and provided new insight into the evolutionary history of intrinsic resistance genes.
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Gang
G
Zhang
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Sébastien Olivier
SO
Leclercq
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Jingjing
J
Tian
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Chao
C
Wang
Department of Bacteriology II, National Institute of Infectious Diseases, Musashimurayama, Tokyo, Japan.
Koji
0000-0003-4289-1115
K
Yahara
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Guomin
G
Ai
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Shuangjiang
S
Liu
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
Jie
0000-0001-5172-6643
J
Feng
D000150:Acinetobacter / Q000145:classification / Q000201:enzymology / Q000235:genetics*; D000151:Acinetobacter Infections / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000201:enzymology / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004352:Drug Resistance, Microbial / Q000187:drug effects / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D022761:Gene Transfer, Horizontal; D059765:Homologous Recombination; D054884:Host-Pathogen Interactions; D006801:Humans; D008826:Microbial Sensitivity Tests; D009713:Nucleotidyltransferases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D013045:Species Specificity; D000198:Spectinomycin / Q000378:metabolism / Q000494:pharmacology; D013307:Streptomycin / Q000378:metabolism / Q000494:pharmacology
D001426:Bacterial Proteins; D000198:Spectinomycin; D009713:Nucleotidyltransferases; C022678:streptomycin 3''-adenylyltransferase; D013307:Streptomycin