New update on molecular diversity of clinical Staphylococcus aureus isolates in Iran: antimicrobial resistance, adhesion and virulence factors, biofilm formation and SCCmec typing

• Published in: Molecular biology reports 2022-04, Vol.49 (4), p.3099-3111
• Main Authors: Tabandeh, Mahtab, Kaboosi, Hami, Taghizadeh Armaki, Mojtaba, Pournajaf, Abazar, Peyravii Ghadikolaii, Fatemeh
• Format: Article
• Language: English
• Subjects: Animal Anatomy; Animal Biochemistry; Anti-Bacterial Agents - pharmacology; Antibiotic resistance; Antibiotics; Antimicrobial agents; Antimicrobial resistance; Biofilms; Biomedical and Life Sciences; Clonal selection; Cross-Sectional Studies; Drug resistance; Drug Resistance, Bacterial - genetics; Histology; Humans; Iran - epidemiology; Life Sciences; Methicillin-Resistant Staphylococcus aureus - genetics; Microbial Sensitivity Tests; Molecular Typing; Morphology; Original Article; Pathogenicity; Phenotypes; Staphylococcal Infections - epidemiology; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - genetics; Staphylococcus infections; Tissue culture; Typing; Vancomycin; Virulence; Virulence factors; Virulence Factors - genetics
• ISSN: 0301-4851; 1573-4978
• DOI: 10.1007/s11033-022-07140-7

Background Staphylococcus aureus is often considered as a potential pathogen and resistant to a wide range of antibiotics. The pathogenicity of this bacterium is due to the presence of multiple virulence factors and the ability to form biofilm. SCC mec types I, II and III are mainly attributed to HA-MRSA, while SCCmec types IV and V have usually been reported in CA-MRSA infections. Methods and results In this study, we performed a cross-sectional study to determine the antimicrobial resistance, adhesion and virulence factors, biofilm formation and SCC mec typing of clinical S. aureus isolates in Iran. S. aureus isolates were identified using microbiological standard methods and antibiotic susceptibility tests were performed as described by the Clinical and Laboratory Standards Institute (CLSI) guidelines. Inducible resistance phenotype and biofilm formation were determined using D-test and tissue culture plate methods, respectively. Multiplex-PCRs were performed to detect adhesion and virulence factors, antibiotic resistance genes, biofilm formation and SCC mec typing by specific primers. Among 143 clinical samples, 67.8% were identified as MRSA. All isolates were susceptible to vancomycin. The prevalence of cMLS B , iMLS B and MS phenotypes were 61.1%, 22.2% and 14.8%, respectively. The TCP method revealed that 71.3% of isolates were able to form biofilm. The predominant virulence and inducible resistance genes in both MRSA and MSSA isolates were related to sea and ermC respectively. SCC mec type III was the predominant type. Conclusions Data show the high prevalence rates of virulence elements among S. aureus isolates, especially MRSA strains. This result might be attributed to antibiotic pressure, facilitating clonal selection.