Competition assays between ESBL-producing E. coli and K. pneumoniae isolates collected from Lebanese elderly: An additional cost on fitness

Abstract

The dissemination of Multi Drug Resistant Organisms (MDROs) is one of the major public health problems addressed nowadays. High fecal carriage rates of MDR Enterobacteriaceae were reported from Lebanese nursing homes. Studies have shown that the acquisition of resistance genes by bacteria might confer a fitness cost detected as a decrease in the frequency of these bacteria as compared to sensitive isolates. In this study, the competitive growth of MDR Enterobacteriaceae isolated from elderly is assessed. Sensitive and ESBL-producing Escherichia coli and Klebsiella pneumoniae isolates were identified. Inter-species in-vitro competition assays were conducted in different combinations. ESBL-producing K. pneumoniae presented a fitness cost when competing against sensitive E. coli. On the other hand, resistant E. coli only showed a fitness cost when growing in presence of two sensitive K. pneumoniae isolates. These results suggest that ESBL-production genes in E. coli and K. pneumoniae may confer a fitness cost that leads to the decrease in frequency of these bacteria in interspecies competitions. Culturing bacteria in a medium with more diverse isolates can provide better insights into bacterial competition and resistance dynamics, which can be exploited in the search for alternative therapeutic approaches towards the colonization of resistant bacteria.

Characterize carbapenem-resistant Klebsiella pneumoniae isolates for nosocomial pneumonia and their Gram-negative bacteria neighbors in the respiratory tract

“…Oppositely, the latter implied competition among bacterial species. Hafza et al [40] suggested that competition between ESBL-production genes in E. coli and K. pneumoniae confer a fitness cost may provide us a new perspective. And also, the differences in the main type of carbapenemases production among resistant bacteria should be considered.…”

Replacement of the Dominant ST191 Clone by ST369 Among Carbapenem-Resistant Acinetobacter baumannii Bloodstream Isolates at a Tertiary Care Hospital in South Korea

“…Percent recovery was evaluated by modifying a method described previously (Hafza et al, 2018). We used the gentamicinsusceptible ST369 A. baumannii strain, and randomly selected five gentamicin-resistant ST369 and five gentamicin-resistant ST191 A. baumannii isolates to create five combinations.…”

ESBL Escherichia coli Isolates Have Enhanced Gut Colonization Capacity Compared to Non-ESBL Strains in Neonatal Mice

“…ESBL-producing Enterobacterales, such as Escherichia coli strains, are identified worldwide and can colonize healthy individuals without antibiotic exposure ( 10 ). While some ESBL E. coli appear to have an associated fitness cost ( 11 , 12 ), others carry genes that may convey competitive advantage ( 13 , 14 ). One example of such genes is fimbriae, which have been implicated to be essential for adherence and invasion of gut colonization ( 15 ).…”