MRSA screening and spa gene detection in isolates from healthcare workers at ophthalmology hospital in Egypt

Abstract

Background: Staphylococcus aureus has a major role in different types of eye infections as conjunctivitis, keratitis, and endophthalmitis. Methicillin-resistant Staphylococcus aureus (MRSA) was almost restricted to hospitals, but its prevalence has been increased in people outside hospitals. The cell wall of Staphylococcus aureus has protein A which can bind to the Fc portion of IgG. This ptnA is encoded by surface protein A of Staphylococcus aureus (spa) gene that contains a highly polymorphic sequence which is composed of repeats of 24-bp. Sequence typing of the spa gene repeat region is used to study the epidemiology of MRSA. The purpose of this study was screening of MRSA strains among healthcare workers (HCWs) in the Hospital of the Research Institute of Ophthalmology (RIO), Giza, Egypt, and detecting spa gene in their DNAs by PCR. Results: In the present study, 81 samples from healthcare providers in the hospital of the Research Institute of Ophthalmology, Egypt, were screened for MRSA. Out of these 81 samples, 41 isolates (50.6%) were identified as coagulase-positive Staphylococcus aureus. Twelve staphylococcal isolates were resistant to both oxacillin and cefoxitin, and those were identified as MRSA with a percentage of 14.8% (12/81). Conventional PCR could detect spa gene in 10 out of 12 DNA MRSA with a percentage of 83.3% (10/12). Conclusion: In the present study, the prevalence of MRSA in HCWs was 14.8%. Since amplification of spa gene by PCR is a necessary preliminary step for spa typing of MRSA and since using different primers for spa gene amplification might affect PCR results, then proper selection of the primers and thermal cycling reaction conditions are recommended for PCR performance and spa typing.

An Intricate Discussion on the Conventional and Rapid Identification Methods to Identify MRSA: A Review

“…spa typing -Staphylococcus aureus encodes a number of virulence factors, that includes the staphylococcal protein A (spa), which is also known as Ig-binding protein A. spa captures the antibody IgG in an inverted orientation leading to failure of the bacterial cell lysis by preventing phagocytosis by the host immune system (Votintseva et al, 2014). It is not necessary that every MRSA isolate must have spa gene, but according to an article from Iran, approximately 83% MRSA were found to be positive for the spa gene (Haggag, Aboelnour, & Al-Kaffas, 2019). It has been seen that most of the epidemic MRSA strains contain more than seven repeats of 24bp sequence in the X region (Fc-binding region) of the protein A gene.…”

Antimicrobial Resistance and Virulence Gene Profile of Clinical Staphylococcus aureus: A Multi-Center Study from Ethiopia

“…34 In this research, the spa gene was detected in all isolates; however, other studies found that the change in primer binding sites resulted in up to 3% non-detection. 35 A similar problem was handled by Votintseva et al, in 2014 using a new primer. 36 Overall, from both MSSA and MRSA strains, virulence gene (pvl) prevalence was found to be 59.30%.…”