Prevalence of Multi-drug Resistant Acinetobacter baumannii in Hospitalized Patients

Abstract

The aim of study was to determine the prevalence of multi-drug resistant Acinetobacter baumannii and various resistant mechanisms in cli nical samples of the patients, admitted in Pakistan Institute of Medical Scienes (PIMS). A. baumannii can result in a wide range of infections, including bacteremia, pneumonia, urinary tract infection, peritonitis, etc. This organism is becoming resistant to many and mostly all standard antibiotics. The reason for multi-drug resistance can be the production of extended spectrum p- lactamses(ESBLs), carbapenemases/ metallo p- lactamases or AmpC p-lactamases. A total of 91 isolates were obtained from PIMS during the period of February 2010 to December 2010. These isolates were identified to specie level by biochemical 20E kit, at Microbiology Laboratory, Pathology Department, Pakistan Institute of Medical Sciences (PIMS), Islamabad. The antibiotic susceptibility testing was performed by standard disc diffusion method as recommended by CLSI. The prevalence of MDRs was100% in A. baumannii. The antibiotic susceptibility profile showed that minocycline and tigecycline were the most effective drug against A.baumannii. Combination disc method, Modified Hodge test, EDT A disc synergy test and AmpC disc test were performed for detection of extended spectrum p-lactamases (ESBLs), Carbapenemases, Metallo p-lactamases, and AmpC p-lactamases respectvely. Carbapenemases/metallo p-lactamases production were 100% in A. baumannii isolates. AmpC prevalence was observed in 41.76%, while ESBL production was 0% in A. baumannii isolates. All p-lactamases were found to be more common in new born babies in new natal intensive care unit. All p-lactamases production represents clinical threat due to their resistance to the therapeutic inhibitors. Use of combined therapy may help in the treatment of infections due to resistant organisms. Predisposing factors that make patients susceptible to these infections include concurrent infections, prosthetic devices, surgery, administration of broad-spectrum antibiotics, and emergence of multidrug resistant pathogens most included A. baumannii. It is now recognized that Acinetobacter spp. plays a significant role in the colonization and infection of patients admitted to hospitals. Introduction of new antimicrobial agents is required to meet the challenge. Increased frequency of Multi drug resistance needs for continuous surveillance to determine prevalence and evolution of these enzymes in Pakistan.