Phenotypic Determination of Some Virulence Factors in Staphylococci Isolated From Faecal Samples of Children in Ile-Ife, Nigeria

Abstract

This study identified some virulence factors in staphylococci isolated from the faecal samples of children in Ile-Ife, Nigeria and also determined the relationships in the expressions of these virulent factors in the S. aureus and coagulase negative staphylococci (CoNS) isolates. Production of coagulase, haemolysin, protease, β-lactamase and formation of capsule and biofilm as well as haemaglutination characteristics were investigated on 180 staphylococci isolates using standard methods. The results showed that expression of virulence factors varied in isolates. The rate of expression was higher in S. aureus than in CoNS although this difference was not statistically significant (p>0.05). Strains of CoNS that expressed up to four virulence factors were isolated. Haemolysin was the virulence factor produced by most of the isolates while protease production was the least encountered. The results revealed that the staphylococci strains isolated from faecal samples of children expressed virulence factors and might have an important role in the pathogenesis of infections. It is also shown that those CoNS species isolated from the faecal samples of children could not be ignored or classified as mere contaminants.

Key words: Staphylococcus aureus, coagulase-negative staphylococci, virulence factors, faecal, children.