Abstract Introduction and objective: This work describes the importance of adopting effective methods of sampling reprocessed endoscopes for the detection of microorganisms adhered to the internal walls of these devices. The objective of this work is to compare the rate of bacterial contamination of the channels of reprocessed endoscopes, through irrigation water culture and that obtained after brushing the channels. A secondary objective was to determine the antimicrobial susceptibility of the pathogens isolated in both methods. Method: A total of 26 endoscopes (duodenoscopes, gastroscopes, colonoscopes, bronchoscopes and echoendoscopes) were subjected to automatic cleaning and reprocessing before use in patients at Hospital Juárez de México. Cleaned and reprocessed endoscopes were simultaneously subjected to two bacteriological test methods based on no brushing (method A) and brushing (method B) of the channels. Bacterial strains isolated after carcass culture were identified to genus and species level and subjected to antimicrobial resistance testing. Results: Method A revealed zero rate of residual bacterial contamination in both channels (suction and working). The microbiological results obtained by method B revealed bacterial contamination rates of 30.7%. Bacterial strains belonging to the families Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, Micrococcaceae and Staphylococcaceae were identified. High rates of antimicrobial resistance were detected against 12 tested antibiotics from eight different families. Conclusion: Implementation of microbiological surveillance of endoscope reprocessing with modified sampling methods is necessary to prevent healthcare-associated infections from endoscopic procedures.

Resumen Introducción y objetivo: Este trabajo describe la importancia de adoptar métodos efectivos de muestreo de endoscopios reprocesados para la detección de microorganismos adheridos a las paredes internas de estos dispositivos. El objetivo de este trabajo es comparar la tasa de contaminación bacteriana de los canales de endoscopios reprocesados, mediante cultivo del agua de irrigación y la obtenida posterior a un cepillado de los canales. Un objetivo secundario fue determinar la sensibilidad antimicrobiana de los patógenos aislados en ambos métodos. Método: Un total de 26 endoscopios (duodenoscopios, gastroscopios, colonoscopios, broncoscopios y ecoendoscopios) fueron sometidos a limpieza y reprocesamiento automático antes de su uso en pacientes del Hospital Juárez de México. Los endoscopios limpios y reprocesados se sometieron simultáneamente a dos métodos de prueba bacteriológica basados en ausencia de cepillado (método A) y cepillado (método B) de los canales. Las cepas bacterianas aisladas después del cultivo de canales se identificaron a nivel de género y especie y se sometieron a pruebas de resistencia antimicrobiana. Resultados: El método A reveló cero tasa de contaminación bacteriana residual en ambos canales (succión y trabajo). Los resultados microbiológicos obtenidos por el método B revelaron tasas de contaminación bacteriana del 30.7%. Se identificaron cepas bacterianas pertenecientes a las familias Enterobacteriaceae, Bacillaceae, Pseudomonadaceae, Micrococcaceae y Staphylococcaceae. Se detectaron altas tasas de resistencia antimicrobiana contra 12 antibióticos probados de ocho familias diferentes. Conclusión: La implementación de la vigilancia microbiológica del reprocesamiento de endoscopios con métodos modificados de muestreo es necesaria para prevenir infecciones asociadas a la atención de la salud por procedimientos endoscópicos.

ABSTRACT Disposal of Umbilical Cord Blood Units due to microbial contamination is a major problem in Cord Blood Banks worldwide as it reduces the number of units available for transplantation. Additionally, economic losses are generated as result of resources and infrastructure used to obtain such units. Umbilical Cord Blood Units that showed initial microbial contamination were subject to strains isolation, identification, and characterization by sequencing the 16S rRNA gene and Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR). Moreover, tests of antimicrobial resistance/sensitivity and phenotypic activities that may play an important role in microbial infection were performed. Microbial contamination was detected in 120 Umbilical Cord Blood Units (2.31%) in the period from 2003 to 2013. The most frequently isolated strains were Enterococcus faecium, followed by Staphylococcus epidermidis, Escherichia coli, Enterococcus faecalis, Staphylococcus haemoliticus, Klebsiella pneumoniae, Enterococcus durans, Lactobacillus helveticus, Enterococcus hiriae and Roseomonas genomospecies 5. The ERIC-PCR assays revealed a wide genetic diversity in some strains although belonging to the same genus and specie, indicating different sources of contamination. Broad-spectrum penicillins, third generation cephalosporins, aminoglycosides, and fluoroquinolones showed lower inhibitory activity on the tested strains. All strains were proteolytic, 67.69% were amylase-positive, 27.6% hemolysis-positive, and 34.71% nuclease-positive. The most common sources of contamination were: vaginal flora, digestive tract, and skin flora, highlighting the need for staff training in good manufacturing practices in collection SCU since all contaminants identified are part of the microbial flora of the donors. Implications and consequences in the therapeutic use of Umbilical Cord Blood Units for transplantation contaminated by multiresistant bacteria in immunocompromised patients are discussed.