Características epidemiológicas dos microrganismos resistentes presentes em reservatórios de uma Unidade de Terapia Intensiva

Abstract

The environment placed by colonized or infected patient may become infected by pathogenicbacteria and constitute a secondary reservoir favoring the cross infection. The identification ofpotential reservoirs of epidemiological important microorganisms in the hospital environmentconstitutes an indispensable measure of prevention of its spread. This study aimed todetermine epidemiological characteristics of microorganisms of clinical importance whenpresent on surfaces, equipments and in solutions and patient blood culture from an Intensivecare Unit from Belo Horizonte. It was a cross-sectional study conducted from July to October2009. Samples were obtained from the degermant soap and by swabs of surfaces on cardiacmonitor, mechanical ventilator, bedside rail, faucet, bedside table, stethoscopes and sink.Concurrently to the environmental sample it was obtained routine culture from ICU adultpatients. Environment samples without dilution were cultured onto Brain Heart Infusion(BHI), MacConkey and Sabouraud Agar at 37º for 48h. The bacteria were identified bycolonial morphology, Gram stain, catalase and API Kit. The susceptibility test was performedby diffusion disc for imipenem, vacomycin, ceftriaxone and ciprofloxacin. The bacterialisolates from environment and routine cultures were compared by the repetitive extragenicpalindromic sequences (rep-PCR) test for similarity analysis. The analyses were performed atthe Ecology and Physiology of Microorganisms laboratory and Genetic of Microorganismslaboratory from Minas Gerais Federal University. It was verified an important contaminationof surfaces and equipment from UTI (P<0,004). The stethoscopes, mechanical ventilators andtap water showed the highest average of contamination. There wasnt contamination in thedegermant solution (PVP-I 10%). On the stethoscopes from the isolation unit were detectedVancomycin resistant Enterococcus faecalis, Staphylococcus aureus and multi-resistantAcinetobacter baumannii. Between one isolate of multi-resistant Acinetobacter baumanniidetected on the mechanical ventilator and a sample of blood culture patient there was 80% ofsimilarity. Considerable percentage of similarity (60-65% - IC: 85%) were, still, observedamong others bacterial isolates from the environment and patient blood cultures. Thesimilarities among environment bacterial isolates and samples of patients blood culturesreinforce the importance of epidemiological surveillance regarding the chance of pathogenshorizontal transference. In conclusion, inanimate surfaces frequently touched and equipmentsnear by the patients in ICU contaminated by resistant bacteria suggest clonal relatedness withbacterial isolates from patient blood culture. Thus it is necessary to reinforce measures ofcontrol, reduction and prevention of multi drug-resistant microorganisms spread. In additionto better attention to surfaces and equipment decontamination in ICU and efficacy assessment,aspects of great relevance in this context, not evaluated in this study.