Department of Immunology and Molecular Biology, School of Biomedical Sciences, Makerere University College of Health Sciences, P. O Box 7072, Kampala, Uganda.
Centre for Intervention Science in Maternal and Child Health, University of Bergen, Bergen, Norway.
BMC Microbiol. 2024 Aug 19;24(1):307. doi: 10.1186/s12866-024-03460-9.
Staphylococcus aureus (S. aureus) often colonizes the human skin, upper respiratory and genital tracts. In the female genital tract, it can be passed on to the newborn during vaginal delivery leading to either ordinary colonization, or neonatal infections notably umbilical stump sepsis, scalded skin syndrome, arthritis, or bacteraemia/sepsis. These infections are mediated by staphylococcal virulence factors such as (i) Staphylococcal Enterotoxins A, B, C, D, and E encoded by the sea, seb, sec, sed, see genes, (ii) Exfoliative Toxins A and B encoded by the eta and etb genes, (iii) Toxic Shock Syndrome Toxin 1 (TSST-1) encoded by the tst gene, (iv) Panton-Valentine Leukocidin (PVL) encoded by the pvl gene, and (v) Hemolysins alpha and delta encoded by the hla and hld genes, respectively. We determined the prevalence of S. aureus possessing one or more virulence factor genes and of methicillin resistant Staphylococcus aureus (MRSA) in this population.
This was a cross-sectional study, which used 85 S. aureus isolates from the Chlorohexidine (CHX) clinical trial study in Uganda. The isolates had been obtained by culturing vaginal swabs (VS) from 1472 women in labour, frozen at minus 80C, then thawed, sub-cultured, and tested for the selected virulence genes sea, seb, sec, sed, see eta, etb, tst, pvl, hla and hld, and for the methicillin resistance determining gene (mecA). Data were analyzed using SPSS version 20.
Of the 85 S. aureus isolates 13 (15.3%) were positive for one or more virulence factor genes, as follows: pvl 9/85 (10.6%), hld 5/85 (5.9%), sea 1/85 (1.2%) and seb genes 1/85 (1.2%). The other virulence genes (sec, sed, see, eta, etb, hla and tst) were not detected in any of the isolates. MRSA was detected in 55.3% (47/85) of the isolates, but only two of these carried the pvl virulence gene.
This study demonstrated that 15% of the S. aureus colonizing the female lower genital tract of mothers in labour in central Uganda carried one or more virulence genes, mostly pvl, indicating potential for newborn infection with S. aureus acquired in the maternal birth canal. More than half of the isolates were MRSA.
金黄色葡萄球菌（S. aureus）常定植于人体皮肤、上呼吸道和生殖道。在女性生殖道中，它可在阴道分娩时传递给新生儿，导致普通定植或新生儿感染，尤其是脐部残端败血症、烫伤样皮肤综合征、关节炎或菌血症/败血症。这些感染由金黄色葡萄球菌毒力因子介导，如（i）由 sea、seb、sec、sed、see 基因编码的肠毒素 A、B、C、D 和 E，（ii）由 eta 和 etb 基因编码的剥脱毒素 A 和 B，（iii）由 tst 基因编码的毒性休克综合征毒素 1（TSST-1），（iv）由 pvl 基因编码的潘顿-瓦伦丁白细胞毒素（PVL），以及（v）分别由 hla 和 hld 基因编码的溶血性素 alpha 和 delta。我们确定了该人群中携带一种或多种毒力因子基因的金黄色葡萄球菌和耐甲氧西林金黄色葡萄球菌（MRSA）的流行情况。
这是一项横断面研究，使用了来自乌干达氯己定（CHX）临床试验的 85 株金黄色葡萄球菌分离株。这些分离株是通过培养 1472 名分娩妇女的阴道拭子（VS）获得的，在-80°C 下冷冻，然后解冻、传代培养，并检测选定的毒力基因 sea、seb、sec、sed、see eta、etb、tst、pvl、hla 和 hld，以及耐甲氧西林决定基因（mecA）。使用 SPSS 版本 20 对数据进行分析。
85 株金黄色葡萄球菌分离株中，有 13 株（15.3%）携带一种或多种毒力因子基因，如下所示：pvl 9/85（10.6%）、hld 5/85（5.9%）、sea 1/85（1.2%）和 seb 基因 1/85（1.2%）。其他毒力基因（sec、sed、see、eta、etb、hla 和 tst）在任何分离株中均未检测到。85 株分离株中检测到耐甲氧西林金黄色葡萄球菌 55.3%（47/85），但只有两株携带 pvl 毒力基因。
本研究表明，乌干达中部分娩母亲的女性下生殖道定植的金黄色葡萄球菌中有 15%携带一种或多种毒力基因，主要是 pvl，表明新生儿有通过母亲产道获得金黄色葡萄球菌感染的潜在风险。超过一半的分离株为耐甲氧西林金黄色葡萄球菌。
