Identification of the Multiresistance Gene <i>poxtA</i> in Oxazolidinone-Susceptible <i>Staphylococcus haemolyticus</i> and <i>Staphylococcus saprophyticus</i> of Pig and Feed Origins
Lin Chen,
Jian-Xin Hu,
Chang Liu,
Jiao Liu,
Zhen-Bao Ma,
Zi-Yun Tang,
Ya-Fei Li,
Zhen-Ling Zeng
Affiliations
Lin Chen
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Jian-Xin Hu
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Chang Liu
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Jiao Liu
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Zhen-Bao Ma
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Zi-Yun Tang
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Ya-Fei Li
Public Monitoring Center of Agro-Product of Guangdong Academy of Sciences, Guangzhou 510640, China
Zhen-Ling Zeng
College of Veterinary Medicine, Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China
Previous studies on the prevalence and transmission mechanism of oxazolidinone resistance gene poxtA in CoNS are lacking, which this study addresses. By screening 763 CoNS isolates from different sources of several livestock farms in Guangdong, China, 2018–2020, we identified that the poxtA was present in seven CoNS isolates of pig and feed origins. Species identification and multilocus sequence typing (MLST) confirmed that seven poxtA-positive CoNS isolates were composed of five ST64-Staphylococcus haemolyticus and two Staphylococcus saprophyticus isolates. All poxtA-positive Staphylococcus haemolyticus isolates shared similar pulsed-field gel electrophoresis (PFGE) patterns. Transformation assays demonstrated all poxtA-positive isolates were able to transfer poxtA gene to Staphylococcus aureus RN4220. S1-PFGE and whole-genome sequencing (WGS) revealed the presence of poxtA-carrying plasmids in size around 54.7 kb. The plasmid pY80 was 55,758 bp in size and harbored the heavy metal resistance gene czcD and antimicrobial resistance genes, poxtA, aadD, fexB and tet(L). The regions (IS1216E-poxtA-IS1216E) in plasmid pY80 were identified in Staphylococcus spp. and Enterococcus spp. with different genetic and source backgrounds. In conclusion, this was the first report about the poxtA gene in Staphylococcus haemolyticus and Staphylococcus saprophyticus, and IS1216 may play an important role in the dissemination of poxtA among different Gram-positive bacteria.
