In vitro antibiotic resistance patterns of Pseudomonas spp. isolated from clinical samples of a hospital in Madinah, Saudi Arabia

Abstract

Pseudomonas spp. are the leading cause of nosocomial infections. Rise in multidrug resistance among clinical isolates limit therapeutic options and hence increase mortality rate. Clinical samples (6840) from a hospital in Madinah, Saudi Arabia were collected for a duration of 14 months to study the frequency, antimicrobial sensitivity pattern and seasonal variations of Pseudomonas isolates. Conventional biochemical tests were done to identify the probable organism and antibiotic susceptibility was performed by disc diffusion method and Phoenix automated microbiology 100 ID/AST system. Pseudomonas represented 6.5% of all positive samples of which 65% were from males. Majority of the organisms (85%) were isolated from sputum and wound swabs followed by catheter tips (6.4%) and throat aspirates (3.4%). From the remaining samples, less than 1% organisms were obtained. Assessment of antimicrobial susceptibility to 11 different antibiotics revealed that imipenem was the most effective with highest sensitivity of 99.5%, and low intermediate resistance of only 0.5%. This was followed by ciprofloxacin (97.5%), ceftazidime (96.3%), cefpiramide/amikacin (94.1%), aztreonam (93.2%), gentamycin (87.7%), ampicillin (83%), and cotrimoxazole (80.1%). The most resistant drugs included augmentin (25%), cotrimoxazole (19.9%), ampicillin (17%) and gentamycin (12.3%) while the least resistant were ciprofloxacin (1.5%) and imipenem (0%). Results recommend imipenem as a promising antibiotic against Pseudomonas infections. In case of resistance to imipenem, ciprofloxacin, ceftazidime, cefpiramide, amikacin, and aztreonam may be recommended. In acute cases, Pseudomonas infections may require combined antimicrobial therapy. Frequency of these infections was the lowest (17%) during spring. It was the highest (30%) during summers and winters but reduced to 22% during autumn maybe due to better hygiene during pilgrimage season.

Isolation and Antimicrobial Susceptibility Pattern of Pseudomonas aeruginosa from Various Clinical Samples at a Tertiary Care Hospital

“…In our study maximum resistance was noted to amoxicillin+clavulinic acid 74.3% which is similar to that reported by Igbalajobi et al, 76.2%, 12 where as Walaa M. Saeed et al, reported much lower resistance to the drug 25%. 20 Next resistant drug in our study was ciprofloxacin 40.1% which is similar to the study conducted by Nishi Tiwari et al, 43%. 11 33.0% of Pseudomonas aeruginosa isolates in our study were resistant to amikacin which is similar to the studies conducted by Nishi Tiwari et al, 41%, 11 whereas Saroj Golia et al, reported only 13.3% of resistance to amikacin much lower than our study.…”