Potentially pathogenic bacteria isolated from neglected air and surfaces in hospitals

Abstract

Hospital infections (HI) are a serious public health problem in many countries. Several studies have identified strains correlating to surgical site infections, many with multi-resistance. The goals of this study was to quantify, to identify and to verify the resistance profile of microorganisms collected at two hospitals settings, and to alert health professionals how environmental contamination can influence hospital infection rates. For air sampling in operating rooms, intensive care unit and materials sterilization center, the impaction method (Spin Air, IUL®) and passive sedimentation were used. For the isolation of bacteria on surfaces and uniforms contact plates (RODAC®) were used. Identification of the microorganisms was performed using Vitek® 2 Systems. The antibiograms were conducted according to the disk diffusion method recommended by CLSI. The surgical center of hospital B presented more than 500 CFU/m 3 in aerial microbial load. In the aerial microbiota of the sampled areas of both hospitals, M. luteus, S. haemolyticus and S. hominis spp hominis were the prevalent microorganisms, with a percentage greater than 30%. On the surfaces and uniforms there was a prevalence of M. luteus (40%) and S. hominis spp hominis (20%) among others, and some of the resistant strains were isolated from environments with microbial load within the recommended limits.

Exposure and Health Effects of Bacteria in Healthcare Units: An Overview

“…Regarding the reference values for bacteria, the median level of colony forming units (CFU) in the wards of hospital 1 was 129.87 (87.46-268.97) CFU/m 3 and, for hospital 2, was 297.97 (217.66-431.85) CFU/m 3 [32], both part of a teaching hospital in Tehran. A study conducted in a Brazilian hospital reported median bacterial loads of 345.25 CFU/m 3 in the post-surgical restroom and 566 CFU/m 3 in operating theatres [33]. Another study in a hospital from Poland reported a median bacterial load of 347.4 CFU/m 3 (257.1-436.3 CFU/m 3 ) [34].…”

“…was detected in the air from a university hospital in Greece [35], in a Ugandan operating theatre [38] and in primary healthcare units and hospital wards in Poland [37]. Micrococcus luteus was found in the female surgery and male surgery wards in an Iranian hospital [39] and in a Brazilian hospital [33]. Other bacteria were mentioned, such as H. pylori [40], Staphylococcus epidermidis, Micrococcus, Streptococcus Flavobacterium spp., Acinetobacter calcoaceticus, Pantoea agglomerans, Enterobacter spp., Klebsiella oxytoca, Branhamella catarrhalis and Neisseria flavescens, Arthrobacter spp., Brevibacterium spp [34], Clostridium difficile [42], Gram-negative bacilli (XDR-GNB) [43], Haemophilus influenzae [41], Bacillus spp.…”

“…[38], Staphylococcus epidermidis, Streptococcus spp., Diphtheroid spp., Micrococcus roseus, Bacillus subtilis. [39], mesophilic bacteria, airborne actinomycetes, S. saprophyticus, S. warneri [37], S. haemolyticus and S. hominis [33], Acinetobacter lwoffii, Salmonella typhimuriu and Klebsiella pneumonia [32].…”

“…Regarding health effects, the most prevalent bacteria-associated effects were hospitalacquired infections caused by Gram-positive bacteria and antibiotic-resistant Gram-negative bacteria [34,43], followed by nosocomial diarrhea caused by Clostridium difficile [42,44], nosocomial infections, and infections in immunocompromised people [33,37]. The other infections reported were bloodstream infections [33]; osteoarticular infections [41]; respiratory and infection diseases [36]; allergenic properties [34]; chronic active gastritis; gastric and duodenal ulcers [40]; osteomyelitis [41]; bacteremia; infections of skin, bones and joints; endocarditis; and central venous catheter infection [33]. The highest microbial load was found in the PSRR (566 CFU/m 3 , Hospital B) and the lowest in the ORT (124.5 CFU/m 3 , Hospital B).…”