Susceptibility of Minocycline against Carbapenem Resistant Gram-Negative Bacilli

Abstract

Objective: Pathogens resistant to ≥3 antimicrobial agents are
 referred to multi-drug resistant (MDR) pathogens. Although several antibiotics
 are available, antibiotics with broader spectrum of activity is required. The
 present study aimed to evaluate the in vitro susceptibility of minocycline
 against Carbapenem resistant gram-negative bacilli and its concordance
 sensitivity as compared to Tigecycline. Methods:
 Non-repetitive, consecutive isolates carbapenem resistant gram-negative bacilli
 including MDR Klebsiella pneumoniae (K. pneumoniae) and Acinetobacter spp. were used for evaluation using Epsilometer test
 (E-test). The minimum inhibitory concentration (MIC) cut-off range for
 minocycline was based on Clinical and Laboratory Standards Institute (CLSI,
 2016) and the interpretation (sensitive<4, intermediate=8, resistant ≥16)
 was considered valid for both, Enterobacteriaceae
 and Acinetobacter. Concordance
 susceptibility of minocycline was compared with that of tigecycline. Results:
 Overall, 18 isolates from MDR Acinetobacter
 spp., 20 isolates from MDR Enterspp.obacter spp. (18 E. coli isolates and 2 Enterobacter, undefined), and 63 isolates of
 MDR Klebsiella spp. (58 K. pneumoniae
 isolates and 5 Klebsiella isolates) were evaluated. In vitro, sensitivity of
 minocycline was 50.0% (9/18) in Acinobacter species; 45.0% (9/20) in Enterobacter spp. and 36.5% (23/63) in
 Klebsiella spp., respectively. Of the 101 isolates used, concordance between
 tigecycline and minocycline was observed in 42 isolates (41.6%) and sensitivity
 to both minocycline and tigecycline was observed in 12 isolates (28.6%). The
 Cohen Kappa values showed that the overall concordance between tigecycline and
 minocycline was 0.11 (non-slight agreement).
 
 
 
 
 
 Conclusion: Minocycline is effective against all the three
 carbapenem resistant gram-negative bacteria included in the study. J Microbiol Infect Dis 2018; 8(4):140-146.