Use of antibiotic-fed poultry’s untreated litter as manure has emerged as a new route for drug resistance.
As if poultry pumped with antibiotics were not doing enough damage when it to came to antimicrobial resistance, the poor disposal of their waste is compounding the problem. A study by the Centre for Science and Environment has found that unsafe disposal of chicken litter and use in agricultural fields as manure has opened up a new route for the spread of drug resistance. Litter and soil samples from 12 randomly selected poultry farms in four top poultry states in north India—Uttar Pradesh, Haryana, Rajasthan and Punjab—were tested against 12 control samples of soil collected from land that was 10-20 km from the respective farms. A total of 217 isolates of E. coli, Klebsiella pneumoniae and Staphylococcus lentus were tested for resistance against 16 antibiotics—100% of the E.coli, 92% of the Klebsiella sp. and 78% of the Staphylococcus sp. were found to be multi-drug resistance with 40% of the E. coli and 30% of the Klebsiella isolates resistant to at least 10 of the antibiotics. Dangerous levels of resistance to carbapenems, a “last-resort” class of antibiotics.
A considerable degree of similarity in resistance pattern for E. coli was noticed in both the litter and the farm where the waste had been used as manure. The use as manure is especially threatening because not only does it mean farm produce becomes a channel for spread of resistance, but the mutations that are likely to be sparked off as the pathogens try to cross the species barrier—in, say, trying to make straying cattle a possible host—carry a spectrum of unknown dangers. While there is a National Action Plan on countering antibiotic resistance, the complete lack of awareness at the grassroots puts paid to any such efforts. There is a need to make farmers in these states aware of the less risky manure alternatives available, perhaps even facilitate easy access. Use of untreated chicken litter in farms and in aquaculture could lead to full-blown resistance crisis if left unchecked now.