Evolution of slime production by coagulase-negative staphylococci and enterotoxigenic characteristics of Staphylococcus aureus strains isolated from various human clinical specimens

1 Department of Microbiology, Faculty of Veterinary Medicine, University of Yuzuncu Y l, 65080 Van, Turkey 2 Department of Food Hygiene and Technology, Faculty of Veterinary Medicine, University of Yuzuncu Y l, 65080 Van, Turkey 3 Department of Biology, Faculty of Arts and Sciences, University of Yuzuncu Y l, 65080 Van, Turkey Correspondence Banur Boynukara banur61{at}hotmail.com Received 26 December 2006 Accepted 27 June 2007 The present study was designed to determine the slime production of coagulase-negative staphylococci (CoNS) and the enterotoxigenic properties of Staphylococcus aureus strains, and to evaluate the clinical importance of slime-producing CoNS and enterotoxigenic S. aureus strains isolated from various human clinical specimens. For this purpose, a total of 120 Staphylococcus strains were isolated and identified, and further characterized for their slime production and enterotoxigenicity. Of the clinical isolates, 55 (45.8 %) were found to be S. aureus , and the others (54.2 %) were identified as CoNS. Of the CoNS, 20 (16.7 %) were further identified as Staphylococcus hominis , 18 (15 %) as Staphylococcus epidermidis , six (5 %) as Staphylococcus xylosus , six (5 %) as Staphylococcus warneri , five (4.2 %) as Staphylococcus sciuri , four (3.3 %) as Staphylococcus haemolyticus , and two each (1.7 %) as Staphylococcus simulans , Staphylococcus capitis and Staphylococcus saprophyticus , respectively. Thirty-nine (60 %) of 65 CoNS were found to be slime producers. Slime production was observed in all CoNS, except S. capitis , mostly from blood (38.5 %), tracheal aspiration (20.5 %) and urine (12.8 %) specimens. In addition, of the 55 S. aureus isolates, 46 (83.6 %) were found to be enterotoxigenic, and of these S. aureus strains, 39 (84.7 %) were positive for staphylococcal enterotoxin (SE)A. The results of this study showed that the slime-producing CoNS were mostly found in clinical specimens of blood, tracheal aspirate and urine. SEA was the predominant enterotoxin type detected in S. aureus strains from human clinical specimens. Abbreviations: CoNS, coagulase-negative staphylococci; SE, staphylococcal enterotoxin.