Infection and Drug Resistance (Mar 2024)
Whole Genome Sequence Analysis of Two Oxacillin-Resistant and mecA-Positive Strains of Staphylococcus haemolyticus Isolated from Ear Swab Samples of Patients with Otitis Media
Abstract
Zhao Liu,1,* Ling Wang,2,* Jiabing Sun,1,* Qinghuan Zhang,3 Yue Peng,1 Susu Tang,1 Limei Zhang,4 Xiaobin Li,4,5 Zhijian Yu,1 Tao Zhang6 1Department of Otolaryngology, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, People’s Republic of China; 2Department of Obstetrics, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 3Department of Clinical Laboratory, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, 519000, People’s Republic of China; 4Guangdong Provincial Key Laboratory of Tumor Interventional Diagnosis and Treatment, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, People’s Republic of China; 5Zhuhai Precision Medical Center, Zhuhai Hospital Affiliated with Jinan University (Zhuhai People’s Hospital), Zhuhai, People’s Republic of China; 6Department of Otolaryngology, The First Affiliated Hospital of Jinan University, Guangzhou, People’s Republic of China*These authors contributed equally to this workCorrespondence: Tao Zhang; Zhijian Yu, Email [email protected]; [email protected]: Staphylococcus haemolyticus can cause a series of infections including otitis media (OM), and the oxacillin-resistant S. haemolyticus has become a serious health concern. This study aimed to investigate the genomic characteristics of two strains of oxacillin-resistant and mecA-positive S. haemolyticus isolated from the samples of ear swabs from patients with OM and explore their acquired antibiotic resistance genes (ARGs) and the mobile genetic elements (MGEs).Methods: Two oxacillin-resistant S. haemolyticus strains, isolated from ear swab samples of patients with OM, underwent antimicrobial susceptibility evaluation, followed by whole-genome sequencing. The acquired ARGs and the MGEs carried by the ARGs, harbored by the genomes of two strains of S. haemolyticus were identified.Results: The two strains of oxacillin-resistant S. haemolyticus (strain SH1275 and strain SH9361) both carried the genetic contexts of mecA with high similarity with the SCCmec type V(5C2& 5) subtype c. Surprisingly, the chromosomal aminoglycoside resistance gene aac(6’)-aph(2”) harbored by S. haemolyticus strain SH936 was flanked by two copies of IS 256, forming the IS 256-element (IS 256-GNAT-[aac(6’)-aph(2”)]-IS 256), which was widely present in strains of both Staphylococcus and Enterococcus genus. Furthermore, the two strains of oxacillin-resistant and MDR S. haemolyticus were found to harbor antimicrobial resistance plasmids, including one 26.9-kb plasmid (pSH1275-2) containing msr(A)–mph(C)) and qacA, one mobilizable plasmid pSH1275-3 harboring vga(A)LC, one plasmid (pSH9361-1) carrying erm(C), and one plasmid (pSH9361-2) carrying qacJ.Conclusion: The systematic analysis of whole-genome sequences provided insights into the mobile genetic elements responsible for multi-drug resistance in these two strains of oxacillin-resistant and mecA-positive S. haemolyticus, which will assist clinicians in devising precise, personalized, and clinical therapeutic strategies for treating otitis media caused by multi-drug resistant S. haemolyticus.Keywords: Staphylococcus haemolyticus, ear swabs, mecA, antimicrobial resistance plasmid, whole genome sequence
