Microbiological Examination of the Oxygen Therapy Humidifiers in a University Hospital

Aim: Hospital infections continue to be a primary problem for which the medical world seeks a solution. One potential cause of nosocomial pneumonia in hospitalized patients is the humidification devices used in oxygen therapy. In this study, we aimed to microbiologically examine the oxygen therapy humidifiers in use in various departments of the Düzce University Research and Training Hospital, Turkey. Materials and Methods: Between 16.9.2016 and 20.3.2017, water samples from a total of 102 oxygen therapy humidifiers were collected into sterile containers for culturing in 5% sheep blood agar, eosin methylene blue agar, Sabouraud dextrose agar, and the L？wenstein–Jensen medium. The colonies grown were identified using conventional and automated methods. Results: A total of 98 microorganisms were grown in 69 (68%) of the 102 samples obtained. Of these organisms, 75 (77%) were bacteria and 23 (23%) fungi. Of the bacteria, 56 (75%) were nonfermentative gram-negative bacteria (Chryseobacterium indologenes, Pseudomonas aeruginosa, Acinetobacter lwoffii, Acinetobacter baumannii, Acinetobacter ursingii, Acinetobacter haemolyticus, Sphingomonas paucimobilis, Stenotrophomonas maltophilia, Delftia acidovorans, Brevundimonas diminuta), 13 (18%) Corynebacterium spp., 2 (3%) Rhizobium radiobacter, 1 (1%) Bacillus spp., 1 (1%) Neisseria spp. 1 (1%) Staphylococcus epidermidis, and 1 (1%) Mycobacterium gordonae. Of the fungi, 21 (91%) were molds (Fusarium spp., Aspergillus spp., Penicillium spp., Exophiala spp., Cladosporium spp., Acremonium spp., Cladophialophora spp., Alternaria spp.) and 2 (9%) yeasts (Candida krusei, Candida albicans). Discussion and Conclusion: It was seen that the regulations for use and disinfection of oxygen therapy humidifiers were not adequately observed in the hospital departments. It was concluded that health professionals should be trained and supervised for compliance with the regulations