Is bacteriologic surveillance in endoscope reprocessing stringent enough?

Abstract

Endoscopes, including duodenoscopes, are medical devices that are frequently associated with outbreaks of nosocomial infections. We investigated an outbreak of multidrug-resistant PSEUDOMONAS AERUGINOSA sepsis affecting three patients after endoscopic retrograde cholangiopancreaticography (ERCP). Epidemiologic investigation supplemented by molecular typing revealed that one ERCP scope was the source of infection with P. AERUGINOSA. No contamination with this microorganism was found after screening of washer-disinfectors, connecting tubes, and environmental surfaces in the endoscopy center. PSEUDOMONAS isolates from blood and endoscope channels before gas sterilization with ethylene oxide (ETO) were characterized by molecular typing as "linked isolates". Though the current surveillance system did not prevent the infections in three patients, our microbiological surveillance protocol with routine culturing of endoscopes was helpful in detecting the source of contamination and probably avoided numerous cross-contaminations in other patients who underwent ERCP procedures with endoscopes.

Usefulness of Bacteriological Monitoring of Endoscope Reprocessing

“…Most contemporary flexible endoscopes cannot be heat-sterilized and are designed with multiple channels and ports which are exposed to body fluids and are difficult to clean and disinfect (Nelson et al, 2001). Growth of biofilms inside endoscope channels can result in failure of the endoscope reprocessing and is an important factor in the pathogenesis of endoscopy-related infections (Buss et al, 2008;Kovaleva et al, 2009). Such events should be prevented by well instructed personnel, well functioning washing, disinfection and drying equipment and observance of general hygiene guidelines in the endoscopy center.…”

“…Bacterial transmission from endoscopes to patients tends to be incidentally identified when an unusual species or a microorganism with an uncommon resistance profile is involved. The microorganisms most frequently associated with iatrogenic transmission during endoscopy are gram-negative bacteria (Pseudomonas aeruginosa, Serratia marcescens and Salmonella species), mycobacteria and yeasts (Buss et al, 2008;Kovaleva et al, 2009;Spach et www.intechopen.com Therapeutic Gastrointestinal Endoscopy 142 al., 1993). These microorganisms can be transferred from previous patients or contaminated cleaning sources (reprocessing equipment, water supply lines) by contaminated endoscopes or accessories (Srinivasan, 2003).…”

O impacto da fricção, solução de limpeza e subsequente desinfecção de alto nível na remoção de biofilme buildup-5 e de biofilme tradicional-5 em canais endoscópicos gastrointestinais flexíveis

“…Febre, calafrios e sudorese são alguns dos sinais clínicos apresentados pelos pacientes que desenvolveram processos infecciosos após realizarem endoscopia gastrointestinal com equipamento contaminado (Kovaleva et al, 2009 (Bajolet et al, 2013).…”

“…Em estudo realizado em 37 serviços de endoscopia gastrointestinal de uma capital brasileira, este foi o principal microrganismo detectado nos canais de ar/água de gastroscópios e colonoscópios após o processamento (Ribeiro;Oliveira, 2012). Ele é capaz de formar biofilmes extremamentes difíceis de serem removidos dos canais endoscópicos gastrointestinais Kovaleva et al, 2009).…”

“…A presença de células "persisters" -como os esporos, não morrem nem crescem na presença de biocidas, é um dos mecanismos de tolerância aos biocidas encontrados nos biofilmes (Stewart;Costerton, 2001;Stewart, 2003). O biofilme "buildup" formado na superfície interna dos canais endoscópios gastrointestinais, mesmo que não danificada, poderá em algumas ocasiões ser impossível de ser removido mesmo com várias tentativas de limpeza e desinfeção, sendo, assim, necessária a troca do canal endoscópico gastrointestinal (Kovaleva et al, 2009 Os principais métodos propostos de controle da formação de biofilmes são: a) limpeza mecânica e química ; b) redução do aporte de nutrientes; c) aplicação de biocidas; e d) adsorção de células em superfícies. Substâncias como prata, antissépticos e antimicrobianos para a impregnação da superfície dos substratos têm sido utilizadas para proteger a superfície dos produtos para a saúde da colonização de microrganismos (Schierholz, Beuth, 2001 …”