医療微生物学と診断

Prevalance Pseudomonas aeruginosa Among Libyan Patients and its Association with Hospital's Environment in Benghazi

Abstract

Jamila M.M ALshaiki and Ahmed A. Toweir

A cross sectional study was carried out which included 300 clinical specimens such as urine, pus, throat swabs, ear swabs, blood, taken from patients admitted to different departments, in addition to 300 samples from the surrounding environment in four hospitals in Benghazi. The aim is to identify the major strains of P aeruginosa isolated from various sources in different hospitals from both the patients and surrounding environment, also to determine the level of resistance to the widely used antibiotics in clinical isolates of P aeruginosa. P aeruginosa were isolated from 91 clinical specimens and 18 from environmental sources. All were Gram negative motile bacilli, oxidase positive and grew at 42ºC. All isolates were confirmed by Analytical Profile Index (API 20 NE) for their biochemical activity, all were positive for arginine dihydrogenase, citrate utilization and gelatin hydrolysis, while 37.4% were positive for aerobic glucose utilization. The antibiotic sensitivity tests were carried out according to the disc diffusion method (modified kirby bauer technique). Out of 91 strains of P aeruginosa isolated from clinical specimens and 18 strains from the environment, the most effective antibiotics were respectively Ciprofloxacin (82.2%, 83.3%), Imipenem (80.2%, 72.2%), Amikacin (72.5%, 77.8%) and Tobramycin (49.5%, 50%) Gentamicin showed lowest rate of sensitivity (42.2%, 50%). Other antibiotics tested: ampicillin, chloramphenicol, augmentin, pipemidic acid, colistin sulphate and nalidixic acid. The strains isolated were found to have high or total resistance to them. Pyocin typing was used for the characterization of 109 isolates of Pseudomonas aeruginosa isolated. The scheme of Gillies and Govan was adopted and the procedure gave 86.8% of clinical isolates were typable, while 50% of environmental isolates were typable, 12 (15%) of 79 typable strains isolates from clinical specimens were classifiable while 67 (85%) were nonclassifiable. More over all typable isolates from environment were nonclassifiable. The study concludes that Pseudomonas infection is high among our patients in Benghazi hospitals, and reflects the hospital environment as source of infection. This study also recommends that there should be a review in the current antibiotics policy.