Detection of Gene and Distribution of SCC Types in Invasive and Non-invasive Coagulase-negative Staphylococci.

Background: Coagulase-negative staphylococci, which belong to the normal microbiota of the skin and mucous membranes, are opportunistic pathogens. , a newly described protein, is thought to play an important role in nasal colonization and methicillin-resistant virulence, and it may be acquired from coagulase-negative staphylococci by horizontal gene transfer. It has been considered that understanding the function of gene may help clarify the relevance of the different adhesion mechanisms in the pathogenesis of infections associated with biofilm.

Aims: To investigate the gene presence, staphylococcal cassette chromosome types, and antimicrobial resistance patterns of invasive and noninvasive coagulase-negative staphylococci isolates.

Study Design: Cross-sectional study.

Methods: The study included a total of 180 coagulase-negative staphylococci strains. Non-invasive isolates (n=91) were obtained from the hands of healthy volunteers who do not work at the hospital (n=30), the nasal vestibule of healthy volunteer hospital workers (n=26), and central venous catheter (n=35). Invasive isolates (n=89) were isolated from peripheral blood cultures of inpatients who do not have catheters. All isolates were identified by conventional microbiological methods, automated systems, and, if needed, with matrix-assisted laser desorption/ionization-time of flight. Staphylococcal cassette chromosome typing, and gene detection, antibiotic susceptibility, and gene sequence analysis were performed.

Results: Peripheral blood, central venous catheter colonization, and nasal vestibule isolates were positive for the gene, whereas hand isolates were negative. gene was present in 17 isolates, and no statistical significance was found between invasive and noninvasive isolates (p=0.173). Sequence analysis of the genes showed high homology to related proteins of phage SPbeta-like and RP62A. staphylococcal cassette chromosome type V was the most prevalent regardless of species. staphylococcal cassette chromosome type II was more frequent in invasive isolates and found to be statistically important for invasive and noninvasive isolates (p=0.029). isolates had the overall highest resistance rates. Resistance to ciprofloxacin, trimethoprim-sulfamethoxazole, and erythromycin was found to be higher in isolates from catheter and blood culture. isolates had the highest rate for inducible clindamycin resistance. None of the isolates were resistant to vancomycin, teicoplanin, and linezolid.

Conclusion: The gene is detected in 9.44% of the isolates. There is no statistical difference between the -positive and -negative isolates in terms of antibacterial resistance and the presence of and SCC types. Further studies about the role of at virulence in coagulase-negative staphylococci, especially from clinical samples such as tracheal aspirate and abscess isolates, and distribution of staphylococcal cassette chromosome types are needed.