|Background: Staphylococcus aureus is one of the gram positive bacteria colonizing the human body. It colonizes in approximately one third of the general population worldwide. It particularly colonizes the skin, nasal mucosa, upper respiratory tract and the genital tract. S. aureus is also a pathogen in humans where it causes local infections such as boils among others as well as systemic infections such as acute endocarditis. Newborns come in direct contact with bacterial flora in the vaginal canal and perineum during labor and delivery and this may lead to acquisition of virulent S. aureus through the mouth, the umbilicus or a crack in the skin and causing neonatal infections such as umbilical cord infections, neonatal sepsis, joint arthritis, scalded skin syndrome among others. These infections are mediated by different virulence factors generally grouped into exotoxins, binding proteins, and enzyme encoded by virulence genes such as sea, seb, sec, sed, see, eta, etb, tst, pvl, hla and hld. Aim: The aims of our study were: (i) to explore the prevalence of selected virulence genes of S. aureus isolated from the lower genital tract (LGT) of mothers in labor in Uganda. (ii) To determine the diagnostic accuracy of different S. aureus ID methods against DNAse and tube coagulase as Reference /gold standard tests. (iii) To determine the prevalence of MRSA and its association with pvl virulence factor gene.
Methods: S. aureus isolated from the LGT of mothers in labour in Uganda was studied. These isolates were collected in the parent study i.e. Chlorohexidine (CHX) clinical trial whose aim was to determine if CHX prevents umbilical infections and other illnesses in neonates. Frozen isolates were retrieved, sub cultured and re-identified using both phenotypic and genotypic methods.
Results: The prevalence of S. aureus isolates carrying selected virulence factor genes was 15.3 %. The pvl gene had a higher prevalence than other studied genes i.e. 10.6 %.
Conclusion: Staphylococcus aureus colonizing birth canal of mothers in labour in Uganda are less virulent; this implies that neonates born from those mothers are less likely to acquire virulent Staphylococcus aureus.