Plasmid-mediated multiple antibiotic resistance among Klebsiella pneumoniae and Escherichia coli in a tertiary hospital in Nigeria

Abstract

Introduction: About 34 and 31% respectively of Klebsiella pneumoniae and Escherichia coli from clinical samples were isolated and identified on the basis of morphology, growth and biochemical characteristics. Urinary samples had the highest occurrence of K. pneumoniae and E. coli with 50 and 64.2% incidence rate respectively. Results: Although there was no significant difference in their susceptibility to all the antibiotics (p>0.05), the results of their susceptibility profile showed that K. pneumoniae was more susceptible to augmentin (73.5%), followed by ofloxacin (64.7%) and Cefixime (61.8%). Moreover, E. coli showed highest susceptibility to nitrofuratoin (75%), followed by Cefixime (74.2%) and ceftriaxone (71). The results of their antibiotic resistance pattern revealed that both K. pneumoniae and E. coli showed multi-drug resistant (MDR) phenotype against the tested antibiotics. Both K. pneumoniae and E. coli showed highest resistance against cefuroxime (76.5 and 83.9% respectively) followed by gentamycin (67.7 and 77.4% respectively). However, both K. pneumoniae and E. coli exhibit similar resistant pattern to all the class of antibiotics under investigation (p>0.05). The MAR indexes for the antibiotics used against both K. pneumoniae and E. coli showed that nitrofurantoin has the lowest MAR index (0.018), while the highest was found for cefuroxime (0.08). Curing of resistant markers in K. pneumoniae was variable; but the highest resistant marker cured was that of cefuroxime (76.9%). In E. coli, cloxacillin resistant markers were not cured, but resistant markers to other antibiotics were cured variably. The result further revealed that the frequency of resistant markers cured in K. pneumoniae and E. coli were not significantly different (p>0.05). A total of 18 plasmids with molecular weight ranging from 0.56 to >23.13kbp were observed in the selected multi-drug resistant (MDR) isolates of K. pneumoniae and E. coli. Conclusion: Four different plasmid profile groups were detected for selected MDR isolates of K. pneumoniae with 23.13kbp as the most abundant plasmid. Only one (1) plasmid profile group for MDR E. coli was detected.