Antibiotic susceptibility pattern of carbapenem resistant Escherichia coli and Klebsiella pneumoniae, 2019

The rise in the prevalence of carbapenem resistant bacteria worldwide has made the treatment of nosocomial infections challenging. This is because carbapenem resistant bacteria harbor multiple resistance genes aside the carbapenemase genes. This study was conducted to determine the susceptibility pattern of carbapenem resistant isolates of Escherichia coli and Klebsiella pneumoniae. Previously isolated and characterized carbapenem resistant E. coli and K. pneumoniae were screened for their susceptibility to ceftriaxone, trimethoprim-sulphamethoxazole, doxycycline, amikacin, gentamicin, nalidixic acid, chloramphenicol, colistin, tigecycline and fosfomycin by the Kirby Bauer technique. EUCAST and CLSI breakpoints were used to interpret the zones of inhibition. High level of resistance was observed among the isolates to ceftriaxone (100.00 %), trimethoprim-sulphamethoxazole (100.00 %) and doxycycline (83.33 %). Two-third of the isolates (66.67 %) were observed to be susceptible to amikacin, while 33.33 % of the isolates were gentamicin and nalidixic acid susceptible. Susceptibility to chloramphenicol and colistin was recorded in 16.67 % of the isolates while all the screened isolates (100.0 %) were susceptible to fosfomycin and tigecycline. A higher antibiotic resistance rate was observed among isolates habouring carbapenemase genes (bla_NDM, bla_OXA or both). The MAR indices of the carbapenem resistant isolates ranged between 0.46 and 0.82. So also, all the isolates screened were observed to be resistant to multiple antibiotics, hence MDR isolates. In conclusion, the carbapenem resistant isolates were resistant to multiple antibiotics but were however susceptible to tigecycline, fosfomycin and amikacin.