Abstract

PREVALENCE AND ANTIBIOTIC RESISTANCE PATTERNS OF MULTIDRUG-RESISTANCE AND ESBL-PRODUCING GRAM-NEGATIVE BACTERIA ISOLATED FROM CLINICAL SAMPLES IN A TERTIARY CARE HOSPITAL

Shubham Chavan*, Mohini Mishra, Pallavi Chakor, Kajal Gupta

ABSTRACT

The problem of antimicrobial resistance (AMR) in Gram-negative bacteria has emerged as one of the major dangers to the whole world, threatening the efficacy of antibiotic treatment and raising the rates of morbidity, mortality, and expenditures connected with healthcare. It is essential to conduct continuous surveillance of the trends in the occurrence of AMR so as to ensure the proper choice of antibiotics for the empirical treatments and to be able to implement the stages of the process related to antimicrobial stewardship. The objective of the present study was to analyze the occurrence of Gram-negative bacteria in the tertiary care hospital, to study the patterns of their susceptibility to antimicrobial agents, and to estimate the prevalence of multidrug resistant organisms and those producing extended spectrum beta-lactamases (ESBL). One of the distinctive features of the study was that it was performed using both retrospective and prospective designs over a period of 24 months. 420 non-duplicate Gram-negative bacterial strains obtained from different clinical specimens were studied. Specifically, the bacterial identification was done with the help of recognized microbiological and biochemical methods and the antimicrobial sensitivity was determined with the help of the Kirby-Bauer disc diffusion technique according to the standards presented in CLSI. Multidrug resistance was determined according to the internationally recognized criteria and the confirmation of the fact that the bacteria produce ESBL was carried out with the help of the Combination Disc test. Thus, it should be stated that the urine specimens constituted the majority of clinical samples (40.5%), whereas Escherichia coli was the most widely spread bacteria (41.9%), which was followed by Klebsiella pneumoniae (24.8%). The antimicrobial susceptibility test exhibited significant resistance against fluoroquinolones and third-generation cephalosporins whereas carbapenems and amikacin were found to be highly effective against the bacteria. A significant number of isolates, 234 (representing 55.7%), were also found to be multidrug-resistant (MDR) while 138 (which is 32.9%) isolates were confirmed to produce Extended Spectrum Beta Lactamases (ESBL) with the highest MDR levels recorded in Acinetobacter baumannii. There were serious associations found between the various species of bacteria and MDR or production of ESBL. The study brings to light the increasing rate of antimicrobial resistance among various Gram-negative bacterial pathogens leading to an increased need for continuous monitoring and testing of antimicrobial susceptibility, rational use of antimicrobials and implementation of efficient programmes.

Keywords: Antimicrobial resistance; Gram-negative bacteria; Antibiotic susceptibility testing; Multidrug resistance; Extended-spectrum ?-lactamase; Kirby–Bauer method; Tertiary care hospital.