Hemolytic phenotype analysis of Staphylococcus aureus clinical isolates

Acta Universitatis Medicinalis Anhui 2025, 07, v.60 1312-1319     font:big middle small

Fund programs: National Natural Science Foundation of China (No. 82102460)

Authors:Gao Ju; Weng Shengnan; Leng Guiyun; Li Xin; Yao Jie; Zhou Qiang; Tang Wei

Keywords:Staphylococcus aureus; clinical isolate; hemolytic phenotype; hemolysin; antibiotic resistance; virulence;

DOI:10.19405/j.cnki.issn1000-1492.2025.07.021

〔Abstract〕 Objective To investigate the hemolytic phenotypes of Staphylococcus aureus clinical isolates.Methods The hemolytic phenotypes of 105 Staphylococcus aureus isolates were analyzed and summarized using the three-point inoculation method.Real-time fluorescence quantitative PCR was used to measure the mRNA expression levels of four hemolysin genes (hla,hlb,hlc,and hld) ; The VITEK 2 GP639 antimicrobial susceptibility card was used to detect resistance to commonly used antibiotics ; DNA gel electrophoresis was performed to determine the prevalence of the mecA,sea,tst,and pvl genes ; The microtiter plate crystal violet staining method was used to assess biofilm formation ability ; The CCK-8 assay was used to evaluate cytotoxicity against macrophages.Results Seven hemo- lytic phenotypes were identified among the Staphylococcus aureus clinical isolates. Differences were found among Staphylococcus aureus clinical isolates with different hemolytic phenotypes in terms of mRNA expression levels of he- molysin genes,antibiotic resistance,virulence gene prevalence,biofilm formation ability,and cytotoxicity to mouse macrophages (P <0. 05 ) . Conclusion Staphylococcus aureus clinical isolates exhibit diverse hemolytic pheno- types,which should be a focus across multiple dimensions,including microbiological testing,clinical treatment, and nosocomial infection prevention and control.