Persistence of microbial communities including Pseudomonas aeruginosa in a hospital environment: a potential health hazard

Abstract

BackgroundThe persistence of microbial communities and how they change in indoor environments is of immense interest to public health. Moreover, hospital acquired infections are significant contributors to morbidity and mortality. Evidence suggests that, in hospital environments agent transfer between surfaces causes healthcare associated infections in humans, and that surfaces are an important transmission route and may act as a reservoir for some of the pathogens.This study aimed to evaluate the diversity of microorganisms that persist on noncritical equipment and surfaces in a main hospital in Portugal, and are able to grow in selective media for Pseudomonas, and relate them with the presence of Pseudomonas aeruginosa.ResultsDuring 2 years, a total of 290 environmental samples were analyzed, in 3 different wards. The percentage of equipment in each ward that showed low contamination level varied between 22% and 38%, and more than 50% of the equipment sampled was highly contaminated. P. aeruginosa was repeatedly isolated from sinks (10 times), from the taps’ biofilm (16 times), and from the showers and bedside tables (two times). Two ERIC clones were isolated more than once. The contamination level of the different taps analyzed showed correlation with the contamination level of the hand gels support, soaps and sinks. Ten different bacteria genera were frequently isolated in the selective media for Pseudomonas. Organisms usually associated with nosocomial infections as Stenotrophomonas maltophilia, Enterococcus feacalis, Serratia nematodiphila were also repeatedly isolated on the same equipment.ConclusionsThe environment may act as a reservoir for at least some of the pathogens implicated in nosocomial infections. The bacterial contamination level was related to the presence of humidity on the surfaces, and tap water (biofilm) was a point of dispersion of bacterial species, including potentially pathogenic organisms. The materials of the equipment sampled could not be related to the microbial contamination level. The presence of a disinfectant in the isolation medium suggests that the number of microorganism in the environment could be higher and shows the diversity of disinfectant resistant species. The statistical analysis suggests that the presence of bacteria could increase the risk of transmission by hand manipulation.

Nosocomial infection caused by multidrug resistant Enterobacteriaceae and their spread in inanimate surfaces in East-Algerian hospitals

“…Literatures have previously reported that door handles were the main source of bacteria and this is consistent with this study (De Abreu et al, 2014;Taneja et al, 2004). MALDI-TOF MS is mostly used as the main tool for species identification (Seng et al, 2010;.…”

Biofouling of reverse osmosis membranes: effects of cleaning on biofilm microbial communities, membrane performance, and adherence of extracellular polymeric substances

“…Members of the prominent genus of the Pseudomonadaceae reportedly produce large amounts of EPS (Tseng et al 2013), and have been used as models in many biofouling studies (Herzberg & Elimelech 2007. In addition, this genus is known for its strong resistance to a wide range of antimicrobial agents and antibiotics (Flores Ribeiro et al 2014), and has been found to colonize a diverse range of surfaces, including antiseptic and soap containers (de Abreu et al 2014).…”

Molecular Analysis of Pseudomonas aeruginosa Strains Isolated from Burn Patients by Repetitive Extragenic Palindromic-PCR (rep-PCR)

“…Pseudomonas aeruginosa is a major opportunistic pathogen for hospitalized patients (1). It is most harmful to individuals whose immune systems have been compromised similar to those with in AIDS, cancer, burns, cystic fibrosis, and neutropenia.…”