Study of antimicrobial resistance profile and efflux mediated drug resistance in clinical isolates of Pseudomonas aeruginosa detected by ethidium bromide-agar Cartwheel method

Background: Development of antibiotic resistance or multidrug resistance (MDR) is one of the major causes of treatment failure of bacterial infections and has rapidly evolved into a threat to global health care. Bacterial efflux pumps play a significant role in the development of antibiotic resistance. This study evaluates the prevalence of efflux pump- mediated drug resistance in clinical isolates of P. aeruginosa.Methods: Clinical isolates (n=100) of P. aeruginosa were collected from various clinical laboratories in Kerala and their efflux mediated drug resistance detected by the ethidium bromide (EB) agar Cartwheel method.Results: The EB agar cartwheel method of screening revealed efflux activity in 17% (n=17) strains. The efflux activity was revealed at a minimum concentration of EB at 0 mg/l. P. aeruginosa strains showed the highest activity up to a concentration of 2.5 mg/l.Conclusions: This study discusses the emergence of efflux pump- mediated drug resistance in P. aeruginosa from various clinical samples. Our results showed that 17% drug resistance in P. aeruginosa is attributable to efflux related mechanisms.

Estimation of Phagocytic activity by normal human peripheral blood mononuclear cells on various oral isolates of Candida species – An in-vitro study

Polymorphonuclear neutrophils (PMN) and mononuclear phagocytes represent an important first line and effector function in control of Candida infections. The aim of the study is to determine the in-vitro phagocytic activity of human peripheral blood mononuclear cells against oral isolates of Candida species and its antifungal susceptibility. The study also evaluates the degree of respiratory burst activity of PBMCs. Phagocytic and lytic indices by PBMCs were determined for Candida spp. The respiratory burst activity was evaluated by nitroblue tetrazolium test. Antifungal disc diffusion susceptibility testing was performed. A total of 100 Candida were isolated belonging to the species C.albicans, C. tropicalis, C.krusei and C.auris. Phagocytic and lytic indices of C.albicans was significant when compared to standard strain of C.albicans. For C.tropicalis and C.krusei phagocytic index was significant while lytic index was not significant when compared to standard strain. The inter species comparison of both the indices was not significant for the clinical isolates of Candida. A significant reduction in phagocytic activity was observed for clinical isolates of Candida spp. but lytic activity was variable when compared to the standard strain of C.albicans