Evaluation of some commercial antimicrobial ointments on selected bacterial and fungal strains of clinical importance

Abstract

Background: Resistance of Klebsiella species to conventional antibiotics is often implicated in increasing nosocomial infections, and is due in part to enzymatic hydrolysis either constitutively and/or inductively. Resistance plasmid factors readily spread mostly through Gram-negative bacterial isolates through conjugative plasmids. This study investigated the presence of extended spectrum beta lactamases (ESBL), profiles of plasmids detected, and resistance to conventional antimicrobial agents among clinical isolates of Klebsiella species from three different sources. Method: Seventy Gram-negative bacterial and lactose fermenters from urine, wounds and sputum specimens from three hospitals in the South West region of Nigeria were studied after identificationwith microbial identification system. Antibiogram was determined using modified Kirby-Bauer disc diffusion method. Phenotypic detection of ESBLproduction was carried out using double-disk synergy tests (DDST). Plasmid DNA were extracted by alkaline lysis method, electrophoresed, viewed by a UV-trans-illuminator, with plasmid size and number determined, following standard protocols Results: Twenty-nine (29) or 41% of the seventy clinical isolates were confirmed as Klebsiella species distributed as: Klebsiella pneumoniae 89.66% (26/ 29); Klebsiella oxytoca 6.89% (2/29) and Klebsiella ozanae 3.45% (1/29). Among the K. pneumoniae isolates, 13 (50%) were from urine, 8 (30.77%) from wounds and 5 (19%) from sputum. Multidrugresistance was observed with the isolates; as 28 (96.5%) were resistance to at least four (4) different classes of antibiotics. Among the 29 isolates, 14 (48.3%) Klebsiella species were ESBL-producers while 15 (51.7%) were non-ESBL producers. The ESBL-producers showed higher antibiotic resistance compared to non-ESBL producers, particularly with respect to β-lactam antibiotics. Plasmid DNA, with sizes range of O.78 - 23 kbp were detected in 17 (58.62%) of the isolates.Conclusion: Multidrug resistance (MDR) phenomenon was observed with Klebsiella species particularly among the ESBL-producers harbouring high-molecular weight plasmids. There is need for routine ESBL-production surveillance and the rational choice of antibiotics for infection management, reduction and containment of spread of antibiotic resistance in clinical settings.