Prevalence, Antibiotic Susceptibility Testing, Beta-Lactamase Production and mcr-1 Gene Detection in Uropathogenic Klebsiella Pneumoniae Isolated from A Tertiary Care Hospital in Bhopal: A Prospective Study

Abstract

Introduction: Klebsiella pneumoniae (K pneumoniae) is an inhabitant of the nasopharynx and gastrointestinal tract and it is capable of causing a variety of infections, including urinary tract infection (UTI), pneumonia, liver abscess and septicemia. UTI in humans can be hospital and community-acquired. UTI should initially be treated with Co-trimoxazole, Nitrofurantoin, 1st generation cephalosporins, and Ciprofloxacin. Still, in India, frequent usage of broad-spectrum antibiotics such as cephalosporins, carbapenems and colistin for getting immediate response has led to resistance to these drugs. K pneumoniae possess several different mechanisms of drug resistance for survival. ESBL, MBL and AmpC beta-lactamase production is one of the dominant mechanisms to inactivate the beta-lactam antibiotics. UTI caused by MDR K pneumoniae is often treated with carbapenems and colistin. Inappropriate doses and frequent usage of these antibiotics make bacteria resistant therefore it is important to know about the susceptibility of antibiotics against K pneumoniae before giving broad-spectrum antibiotics in the local community for the better management of UTI.

Methods: The present study is a prospective study. All clean-catch, mid-stream urine samples were collected in the sample collection centre from the patients suspecting UTI. Semi-quantitative culture method (SQCM) was used to isolate K pneumoniae. SQCM is a routinely used culture method as a diagnostic criterion for patients having a UTI. SQCM indicates the bacterial count present in the urine sample. Firstly, K pneumoniae was isolated and identified followed by Antimicrobial-susceptibility testing (AST). After the AST, double disc synergy test checked the production of ESBL, MBL and AmpC beta-lactamase. Lastly, colistin resistance in K pneumoniae was determined by the E-strip method and K pneumoniae strains positive by E-strip method were further screened for mcr-1 gene by PCR.

Results: A total of 11740 urine samples were received and processed. 2465 (21%) samples showed significant growth of uropathogens. Out of all pathogens, 332 (13%) were identified as K pneumoniae.  Other 2133 (87%) pathogens were identified as Enterobacteriaceae members, Pseudomonas aeruginosa, Burkholderia, Acinetobacter baumannii, Enterococcus, and Staphylococcus. Of all the antibiotics we tested in our study, colistin (87%), carbapenems (78-79%) were the most and penicillin (00-43%) group was the least sensitive. ESBL, AmpC and MBL were 203 (61%), 126 (38%) and 83 (25%) respectively in K pneumonia. Colistin resistance was shown by 43 (13%) K pneumonia strains and out of these 43, only 08 (19%) strains were positive for mcr-1 gene.