Heterogeneity of Staphylococcal protein A (spa) genotypes of methicillin-resistant Staphylococcus aureus strains isolated from Duhok City, Northern Iraq

Objectives

Staphylococcus aureus remains a persistent health issue in both hospitals and the community. Producing diversity of virulence factors enabled the microorganism to cause a range of infections such as Staphylococcal Protein A (SpA); an anti-phagocytic protein, is encoded by spa gene and mostly present in methicillin-resistant S. aureus (MRSA). This study aimed to genotype spa gene diversity in MRSA isolates from Duhok City, Iraq.

Methods

A total of 114 frozen isolates were previously collected from students in the host community and Syrian refugees in Duhok. Genotyping of these strains was conducted by using a polymerase chain reaction.

Results

The results showed that the most common band amplicon numbers in the host community, were one and two, 47.14% and 44.29%, respectively. However, compared to the host community (5.71%), the prevalence of spa bands with three bands was higher in Syrian refugee isolates (18.18%) (P-value = 0.05). A statistically significant correlation was found between both study groups regarding the amplicon size (P-value = 0.04). The highest number of isolates (47 and 24) in both study groups expressed bands with amplicon sizes of 1150 base pair (bp)-1200 bp, then followed by 1250 bp-1300 bp; (27 and 25), respectively. In contrast, MRSA isolates from refuges isolates showed no bands for amplicon size 1350-1400, while seven isolates from the host community were typable for the aforementioned amplicon size.

Conclusions

The heterogeneity in prevalent band numbers and amplicon size highlight that the MRSA strains in both study groups are addressed to genetic diversity that can be used for epidemiological purposes and clinical diagnosis. Thus, further genetic studies are required to study this diversity in the region such as multilocus sequence typing and Pulsed Field Gel Electrophoresis