Klebsiella Pneumoniae in Septicemic Neonates with Special Reference to Extended Spectrum β-lactamase, AmpC, Metallo β-lactamase Production and Multiple Drug Resistance in Tertiary Care Hospital.

Background: β-lactamases viz., extended spectrum β-lactamase (ESBL), AmpC, and metallo β-lactamase (MBL) production in Klebsiella pneumoniae has led to a serious concern about septicemic neonates in Neonatal Intensive Care Units due to high resistance against commonly used antimicrobials.

Purpose: To study the prevalence of ESBL, AmpC, and MBL production in K. pneumoniae isolates in neonatal septicemia, to check antimicrobial susceptibility to various drugs including tigecycline; and to assess burden of multiple drug resistance (MDR).

Materials And Methods: Total 24 clinical isolates of K. pneumoniae isolated from 318 blood samples of suspected cases of neonatal septicemia were studied. Isolates were screened for ESBL, AmpC, and MBL production by Clinical and Laboratory Standards Institute (CLSI) disk method, AmpC cefoxitin screen, and imipenem, meropenem, ceftazidime disk screen respectively; and confirmation was done by CLSI phenotypic disk confirmatory test, AmpC sterile disk method, and imipenem ethylenediamine tetracetic acid double disk synergy test respectively. Antimicrobial susceptibility was determined by Kirby-Bauer's disk diffusion method. Efficacy of tigecycline was evaluated using United States Food and Drug Administration guidelines.

Results: Of the 24 K. pneumoniae isolates, co-production of AmpC + MBL was found in more number of isolates (67%) (P < 0.0001) compared to single enzyme production (ESBL and MBL 8% both, AmpC 12.5%). Rate of resistance for penicillins and cephalosporins was highest. Susceptibility was more for imipenem, co-trimoxazole, and meropenem. Nonsusceptibility to tigecycline was low (21%). A total of 23 (96%) isolates were MDR.

Conclusions: Routine detection of ESBL, AmpC, and MBL is required in laboratories. Carbapenems should be kept as a last resort drugs. Trend of tigecycline susceptibility has been noted in the study. Continued monitoring of susceptibility pattern is necessary to detect true burden of resistance for proper management.