Enterobactérias isoladas de baratas (Periplaneta americana) capturadas em um hospital brasileiro

Abstract

Objective. To isolate and identify microorganisms from cockroaches that were captured in a public hospital and to test the antimicrobial susceptibility of these microorganisms. Methods. Cockroaches were captured in the morning and at night. They were placed in flasks rinsed with 70% alcohol, transferred to sterilized flasks, and then taken to the laboratory. Only cockroaches captured whole and live were utilized for the study. After being immobilized at 0 degrees C, each cockroach was placed in a test tube with sterile saline solution (0.8%) and then homogenized. The resulting solution was then placed in the following five culture media: MacConkey agar, nutrient broth, brain-heart infusion agar, Sabouraud agar, and mannitol. The cultures were examined using a stereomicroscope, and colony-forming units were counted. The disk diffusion test was used to determine antimicrobial susceptibility. Results. We found a 56% prevalence of enterobacteria and an 18% prevalence of coagulase-negative staphylococci. Fifteen species of enterobacteria were identified. The most frequent were Klebsiella pneumoniae (17%), Enterobacter aerogenes (14%), Serratia marcescens (13%), Hafnia alvei (12%), Enterobacter gergoviae and Enterobacter cloacae (each 9%), and Serratia spp. (6%). Both the enterobacteria and the coagulase-negative staphylococci showed significant resistance to antimicrobials, including oxacillin. Conclusions. The prevalence of enteropathogenic bacteria and coagulase-negative staphylococci isolated from Periplaneta americana cockroaches in the studied hospital reflects the weakness of the measures adopted both for vector control and for antimicrobial use. The results show the need to implement effective health-institution programs focusing on hygiene and the rational use of antimicrobials.