Microbiological surveillance of operation theatres, intensive care units and labor room of a teaching hospital in Telangana, India

S. Kiranmai, K. Madhavi


Background: Hospital-associated infections are the major cause of patient morbidity and mortality. Environmental monitoring by the microbiological testing of surfaces and equipments is useful to detect changing trends of types and counts of microbial flora. The aims of the study were to count CFU (colony forming unit) rate of indoor air, to identify bacterial colonization of surface and equipments isolated from Operation theatres, ICUs and Labor room of a teaching hospital in Telangana, India.

Methods: Air sampling of 10 OT’s, 4 ICU’s and 1 LR were done by settle plate method. Swabs were taken from different sites and equipments and bacterial species were isolated and identified from them.

Results: Gynaecology OT-2 and 3 showed less bacterial CFU rate of air (6 CFU/m3) followed by Opthamology OT (16 CFU/m3) and highest in Orthopaedics minor OT (72 CFU/m3) and Dental OT (42 CFU/m3 with 1 fungal CFU/m3). Pediatric ICU showed less bacterial CFU rate (28 CFU/m3) followed by Surgery ICU (40 CFU/m3) and highest in Medical ICU (100 CFU/m3 and 5 fungal CFU/m3). Labor room showed 65 CFU/m3. Bacterial species were isolated from 48 (43%) out of total 111 swab samples taken from all OTs and ICUs. The most common isolate was Bacillus species 36 (75%) followed by micrococcus (54%). Pathogenic organisms isolated were 12 Gram negative bacilli and 6 gram positive cocci, the common isolate was Klebsiella spp (7 of 12).

Conclusions: The study shows that OTs were having bacterial CFU rate of air varying from 6-72 CFU/m3 and colonized by contaminants like Bacillus sp and pathogens like Klebsiella sp. ICUs were having bacterial CFU rate of air varying from 28-100 CFU/m3 and colonized with contaminant like Bacillus sp., as well as potential pathogens like Klebsiella, Pseudomonas etc. Fungal CFU were also seen both in OTs and ICUs. High level of microbial contamination indicates the needs for periodic surveillance aimed at early detection of bacterial contamination levels and prevention of hospital acquired infections.


Air sampling, Bacterial colonization, ICU, LR, OT, Settle plate method, Surveillance

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