Livestock Manure as Potential Reservoir of CTX-M Type Extended-spectrum β-lactamase Producing Escherichia coli and Klebsiella pneumoniae Associated with Carbapenemase Production

Increasing faecal carriage rate of extended-spectrum beta-lactamase (ESBL) producing Escherichia coli (ESBL-EC) and Klebsiella pneumoniae (ESBL-KP) among livestock is responsible for abundance of these bacteria in livestock manure which is being extensively used as organic fertilizer in developing countries including India. Use of this manure can be a potential source for spread of these microorganisms to the human community, posing a serious public health threat especially, to manure handlers. There is paucity of data regarding the possible contamination of environment through use of livestock manure from rural India. Analysis of a total of 1080 manure sample pools from different segments of 40 manure heaps each year during the three years period (2015 to 2017) showed a total of 491(45.5%) E. coli and 85 (7.9%) K. pneumoniae to be detected as ESBL producers by double disc synergy test and 3 (0.6%) ESBL-EC and 3 (3.5%) ESBL-KP as carbapenemase producers by CarbaNP test. Among the ESBL producers, 436 (88.8%) ESBL-EC and 59 (69.4%) ESBL-KP were found to harbour bla(CTX-M) genes by PCR. The present study showed an alarmingly high prevalence of ESBL production and emerging evidence of carbapenemase production among E. coli and K. pneumoniae isolates in the manure samples from rural North India. The antibiotic resistance pattern of the ESBL producing isolates revealed high degree of co-resistance to cephalosporin and non-cephalosporin group of antibiotics.