Microbiological hazard for patients caused by bacteria present on synantropic arthropods in hospital environment

In the years 2000-2002 German cockroaches were recorded in about 79.2% of hospitals in Poland. In the years 2003-2006 these insects were captured in selected hospitals, in Poland and bacteria present on the surface of the body of cockroaches were isolated. From cockroaches bodies were isolated many strains of bacteria, e.g. Enterobacter cloacae, Klebsiella pneumoniae, Citrobacter freundii, Serratia marcescens, Pseudomonas aeruginosa, Staphylococcus epidermidis, Enterococcus faecalis, E. faecium; and strains of fungi: Trichosporon beigelii, Fusarium moniliforme i Scopulariopsis brevicaulis. Many strains of them showed resistance to antibiotics and disinfectants. Several of isolated strains demonstrated important mechanisms of antimicrobial resistance: Gram-negative bacilli - AmpC (+), ESBL (+), some strains of Gram-positive cocci - MLSb and MRCNS. It was found that some strains S. marcescens, P. aeruginosa, S. epidermidis formed a biofilm. The possibility of biofilm formation could explain a resistance to some disinfectants, such as: glucoprotamine, monopotassium persulfate, sodium dichloroisocyjanurate. Presence of such strains in hospital ward could cause risk for patients; they could be reservoirs of resistance genes which can be transmitted into other bacteria. The obtained results showed that German cockroaches present in hospital environment should be considered not only as nuisance insects but also as a real source of pathogenic bacteria. Therefore, Pest Management should be an integrated part of nosocomial infection preventive system.