Coagulase-negative Staphylococcus isolated from bloodculture: Causes or contaminants?

Abstract

Introduction According to the results of different investigations, the opinion that isolate of coagulase-negative staphylococci by bloodcultures represents the blood infection in 10-12% patient. The aim of the work was to determine the number of patients with blood infection-sepsa induced coagulase-negative staphylococci isolated by bloodcultures. Material and methods: The research was done at the Institute for Public Health in Nis. The basic group consisted of 56 patients and coagulase-negative staphylococci were segregated form their bloodcultures. The growth of microorganisms was monitored by the computerized apparatus 'Bactec 9120'. Coagulase-negative staphylococci were identified by the standard microbiologic method and Vitec AMS system. Results Eight patients (14.28%) were found to have minimum two signs of blood infection. S. epidermis was isolated in four patients. S. saprophyticus was isolated in the patients on hemodialysis with implanted urinary catheter. S. capitis was isolated in the patients with infarctus miocardi. S. auricularis was isolated in child who was administered the immunosuppressive therapy before and during hospitalization due to an acute asthmatic attack. The isolate of S. simulans was cultivated from samples of the patients hospitalized due to the febrile state. Discussion A correct interpretation of coagulase-negative staphylococci findings in bloodcultures is an overriding part of medical treatment. The best laboratory indicators of the presence of coagulase-negative staphylococci in blood would be to segregate those of the same kind from two samples at the same time but from different anatomic sites in the presence of clinical signs of blood infection. Conclusion In the investigation conducted at the Public Health Institute-Nis, we determined that bloodcultures isolated coagulase-negative staphylococci represent the blood infection on 14.28% patient.