Isolation, Identification And Prevalence Of Pseudomonas Aeruginosa Isolates From Clinical And Environmental Sources In Onitsha Metropolis, Anambra State

This study was aimed to isolate and identify Pseudomonas aeruginosa and to determine the prevalence rate of isolated P. aeruginosa in Hospitals in Onitsha. Isolates of P. aeruginosa were recovered from both clinical and environmental sources using Cetrimide agar, Blood agar, Mueller-Hinton agar and MacConkey agar. All the inoculated plates were incubated at 37°C for 24-48 hours and growth was evaluated on these media. Isolates were identified on the basis of standard bacteriological methods like morphology, colonial characteristics, smell in culture, haemolysis, as well as pigment production on these media. All suspected isolates were further characterized and identified by many biochemical reactions. Results revealed that only 22 (18.3%) isolates were P. aeruginosa, while other 98 (81.7%) represented other bacterial genera. The 22 isolates included 19 (86.4%) environmental isolates and 3 (13.6%) clinical isolates. Pseudomonas aeruginosa was most commonly isolated from sink (13.6%), then mops and cleaning buckets (9.1%) and least from theatre bed, nasal swab, floor, disinfectant, ear and wound swab (4.5%). The pigment varied from bluish-green to yellowish-green with a grape-like odor. All isolates were Gram negative, produced β-hemolysis on blood agar and were motile. The biochemical tests showed all the isolates to be strongly positive for catalase, oxidase, citrate, and casein hydrolysis. The prevalence rate of P. aeruginosa is relatively high and its isolation from sources like sinks and theatre bed could be suggestive of the role of this pathogen in nosocomial infections.