Production of toxic shock syndrome toxin-1 (TSST-1) by Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria.

Abstract

The production frequency of toxic shock syndrome toxin-1 (TSST-1) amongst Staphylococcus aureus strains isolated from humans, animals and foods in Nigeria was investigated. Of 1015 strains tested, 120 (11.8%) were positive for TSST-1. Thirty one (16.0%) of 194 strains from human diarrhoea and wounds were positive compared to 47 (7.1%) of 666 isolates from eight animal species. Goat strains were most often positive for this toxin (17.0%). A total of 42 (27.1%) of 155 strains from foods were positive for TSST-1. Regardless of source, phage non-typable strains (48.3%) were most common amongst TSST-1 producers followed by strains sensitive to phages in several groups (mixed), 18.3%, and phage group III strains (17.5%). Only 6 were phage group I strains (5.0%). TSST-1 producing strains were mostly resistant to penicillin. Eighty-four (70.0%) TSST-1 producers were also enterotoxigenic with staphylococcal enterotoxin C (SEC) most frequently elaborated as 46 (38.9%) strains were positive. However, 42 (35.5%) and 39 (32.5%) strains producing TSST-1 were also positive for SEA and SEB, respectively. It was concluded that TSST-1 producing strains of S. aureus are widespread in humans, animals and foods in Nigeria and such distribution may play some role in the epidemiology of toxic shock syndrome, the prevalence of which is currently unknown in the environment.