Microbiologic profile of flexible endoscope disinfection in two Brazilian hospitals

Abstract

BACKGROUD: Endoscopes are routinely used in hospitals and clinics of the world and they can be potential sources of cross-infection when the decontamination process is unsuitable AIM: The routines of flexible endoscope (bronchoscopes, esophagogastroduodenoscopes and colonoscopes) disinfection procedures used in two Brazilian university hospitals were evaluated during a 3-year period METHODS: Aleatory samples from internal channels of endoscopes were collected after patient examination and after cleaning/disinfection procedures RESULTS: A contamination >3 log10 was achieved in samples recovered from endoscopes after patient examination. These samples yielded gram-negative bacilli (n = 142: 56%), gram-positive cocci (n = 43: 17%), yeast cells (n = 43: 17%), and gram-positive bacilli (n = 26: 10%). Approximately, 72 out of 149 samples (48.32%) collected after undergoing the cleaning and disinfection procedures disclosed gram-negative bacilli (n = 55: 61%), gram-positive cocci (n = 21: 23%), gram-positive bacilli (n = 8: 9%) and yeast cells (n = 6: 7%). Esophagogastroduodenoscopes and colonoscopes were the most frequently contaminated devices. Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterobacter spp, Serratia marcescens, Proteus mirabilis, Citrobacter freundii, Staphylococcus aureus, Staphylococcus coagulase negative, Micrococcus luteus, Candida albicans, C. tropicalis, C. glabrata, C. guilliermondii, Bacillus spp and Corynebacterium spp were predominantly identified CONCLUSION: Inappropriate cleaning and low times of disinfection were respectively the major factors associated with the presence of microorganisms in colonoscopes and esophagogastroduodenoscopes. By analyzing the identified germs, hospital disinfection was considered of either intermediate or poor level. After this investigation, both university centers improved their previous protocols for disinfection and conditions for reprocessing endoscopes.

Is peracetic acid suitable for the cleaning step of reprocessing flexible endoscopes?

“…It is generally acknowledged that the cleaning, rather than the disinfection or sterilization procedure, controls the success of the endoscope [42,43] or angioscopy reprocessing procedure [44] although cleaning alone does not reduce contamination to a safe level [45] . Inadequate cleaning may reduce the efficacy of the disinfection step [46,47] finally leading to contaminated flexible endoscopes after processing, mainly with gramnegative bacteria [48] . Chemical disinfectants work by direct contact between the disinfectant and the microbe, which may be prevented by residual organic material, resulting in incomplete microbial killing [49,50] .…”

Endoscope reprocessing using glutaraldehyde in endoscopy services of Goiânia, Brazil

“…Adequate disinfection is achieved when parameters such as prior cleaning of the equipment, use of germicides in appropriate concentrations and pH, and direct contact between the germicide and the endoscope according to the time period recommended by the manufacturer are strictly observed (19,22) . Studies performed in endoscopy units in Brazil have also observed contact times of glutaraldehyde and endoscopes at less than 30 minutes (7,12) . It is worth mentioning that the Brazilian legislation recommends at least 30 minutes for the disinfection (5) .…”

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

“…Múltiplos estudos demonstram a falta de adesão dos profissionais aos guidelines de limpeza e desinfeção dos endoscópios gastrointestinais (Alfa et al, 2002;Machado et al, 2006;Barbosa, 2008;Ribeiro et al, 2013). Isso tem resultado em equipamentos contaminados por microrganismos, mesmo após o processamento.…”

“…Após a realização dos exames de endoscopia gastrointestinal, os endoscópios tornam-se contaminados, interna e externamente, por bactérias, fungos e vírus das hepatites B e C (Chu, MCalister, Antonoplos, 1998;Alfa, DeGagne, Olson, 1999;Alfa et al, 2002;Ishino, Ido, Sugano, 2005;Obee et al, 2005;e Barbosa, 2008). A carga microbiana pode variar de 10 3 a 10 10 unidades formadoras de colônias por mililitro -UFC/ml (Chu, MCalister, Antonoplos, 1998;Chu, Favero, 2000;e Machado et al, 2006 (Rejchrt et al, 2004;Lee et al, 2004;Machado et al, 2006;Vergis et al, 2007;Barbosa, 2008;Ribeiro et al, 2013) e RNA do vírus da hepatite C (Bisset et al, 2006). A eliminação incompleta desses microrganismos da superfície externa e interna dos endoscópios gastrointestinais após o processamento atesta que a desinfecção de alto nível não foi atingida, pois após este processo espera-se eliminar bactérias vegetativas, fungos, micobactérias e vírus envelopados e não envelopados (Spaulding;Emmons, 1958).…”

“…Entretanto, estudos demonstraram inobservâncias aos protocolos de limpeza dos endoscópios gastrointestinais pelos profissionais responsáveis pelo processamento, por exemplo: utilização inadequada do detergente enzimático no que diz respeito ao controle da temperatura da solução e ao tempo de imersão do endoscópio; não preenchimento dos canais com a solução de limpeza ou preenchimento sem o uso de adaptadores; não fricção dos canais ou frequência indefinida da fricção; e utilização das escovas de limpeza de forma inadequada ou por tempo indefinido (Alfa et al, 2002;Machado et al, 2006;Barbosa, 2008;e Ribeiro et al, 2013).…”