Diversity of SCCmec elements and spa types in South African Staphylococcus aureus mecA-positive blood culture isolates

Abstract

Background The prevalence of Staphylococcus aureus varies depending on the healthcare facility, region and country. To understand its genetic diversity, transmission, dissemination, epidemiology and evolution in a particular geographical location, it is important to understand the similarities and variations in the population being studied. This can be achieved by using various molecular characterisation techniques. This study aimed to provide detailed molecular characterisation of South African mecA-positive S. aureus blood culture isolates by describing the SCCmec types, spa types and to lesser extent, the sequence types obtained from two consecutive national surveillance studies. Methods S. aureus blood culture isolates from a national laboratory-based and enhanced surveillance programme were identified and antimicrobial susceptibility testing was performed using automated systems. A real-time PCR assay confirmed the presence of the methicillin-resistance determinant, mecA. Conventional PCR assays were used to identify the SCCmec type and spa type, which was subsequently analysed using the Ridom StaphType™ software. Multilocus sequence typing was performed on selected isolates using conventional methods. MRSA clones were defined by their sequence type (ST), SCCmec type and spa type. Results A detailed description of findings is reported in this manuscript. SCCmec type III predominated overall followed by type IV. A total of 71 different spa types and 24 novel spa types were observed. Spa type t037 was the most common and predominated throughout followed by t1257. Isolates were multidrug resistant; isolates belonging to all SCCmec types were resistant to most of the antibiotics with the exception of type I; isolates with spa type t045 showed resistance to all antibiotics except vancomycin. The most diverse SCCmec-spa type complex was composed of the SCCmec type IV element and 53 different spa types. Conclusion Although ST data was limited, thereby limiting the number of clones that could be identified, the circulating clones were relatively diverse.

Diversity and Distribution of Spa types among Methicillin Resistant Staphylococcus Aureus Isolated from Humans and Livestock in Kabale District - South Western Uganda

“…The twenty spa types observed among the human in our study agrees with other reports elsewhere showing presence of multiple spa types among the MRSA isolates [25], [27]. However, differences has been observed in the spa types where we observed presence of; t1081, t701, t034, t041, t044, t037, t4677, t127, t1451, t9377, t032, t121, t922, t019, t108, t002, t030, t018, t040 and t012 in our region, while Vanessa et al reported t008, t020, t022, t104, t179, t718, t747, t910, t932, t1094, t2357, t5624, t10683 and t14933 in Portugal [24].This suggests diverse genetic backgrounds and multiple routes of their acquisition and spread.…”

Regulation of virulence and β-lactamase gene expression in Staphylococcus aureus isolates: cooperation of two-component systems in bloodstream superbugs

“…In the current study, out of 61 MRSA strains, SCCmecI and SCCmec V, SCCmecII , SCCmecIII, and SCCmecIV genes were detected in 16.3, 22.9, 36.3, and 21.3% of isolates. This finding was also reported by some researchers from South Africa [ 16 ], Saudi Arabia [ 17 ], and Venezuela [ 18 ]. Surprisingly, none of the MSSA strains carried the VF genes.…”

A 6-Year Update on the Diversity of Methicillin-Resistant Staphylococcus aureus Clones in Africa: A Systematic Review

“…ST5-VII [5C1] was recovered from a patient in the nephrology ward in Algeria ( Djoudi et al, 2014 ). Other reports include ST5-III/V/non-typeable (NT) in South Africa ( Abdulgader et al, 2020 ; Singh-Moodley et al, 2020 ). The related genotypes such as t6065-ST5/ST2629-V [5C2] in Angola ( Conceição et al, 2015a , b ), t6065-ST69-V [5C2] in Libya ( Khemiri et al, 2017 ), and t002-ST105-II [2A] in São Tomé and Príncipe ( Conceição et al, 2015b ) were also noted.…”