Microbiological analysis of hemodialysis water at the Douala General Hospital, Cameroon

Abstract

Rigorous control of the microbiological quality of water in hemodialysis services is important because the immune system of patients with chronic renal failure is weakened. The objective of this study was to determine the microbiological quality of water for hemodialysis in the hemodialysis department of the hemodialysis center of Douala General Hospital in order to improve the disinfection strategy. Twelve water samples were collected each month at different sites of the hemodialysis circuits A (inlet of filters), B (Outlet of filters / inlet of Reverse Osmosis (RO) device) and C (outlet of the RO device / close to the generator) between November 2015 and February 2016 to be analyzed. The bacteria were isolated after filtration of 100 ml of water at each site through nitrocellulose membrane with 0.45 µm microporosity deposited on the surface of the Tryptone Glucose Extract Agar (TGEA) and then incubated at room temperature (20 to 22ºC) for 7 days. After transplanting to different environments, pure bacterial isolates were identified by their cultural characters and marketed biochemical galleries. The colony count was well above the required international standards (˃100 CFU / ml), for the hemodialysis water with a percentage of 50% (6/12) of non-compliance. Among the bacteria identified, nine (07) were Gram-negative bacilli including Pseudomonas fluorescens and Klebsiella pneumoniae subsp ozaenae, three (03) Gram-positive bacilli all Bacillus sp and three (03) Gram-positive cocci all of coagulase-negative staphylococci. The most frequently isolated bacterial genera were Pseudomonas (38.5%), Klebsiella (15, 5%), Bacillus (23%) and Staphylococcus (23%). The detection of a variety of bacteria in the hemodialysis water in this study indicates the need for regular and appropriate monitoring of water for hemodialysis by the hemodialysis center of Douala General Hospital to ensure a better quality of life for patients undergoing this treatment.