By amplicon sequencing of bacterial integrons from polluted Indian river sediments, CARe researchers have identified novel, mobile resistance genes to several classes of antibiotics. The most striking finding was the discovery of the fourth mobile sulfonamide resistance gene ever found, given the name sul4. The protein has only 34% amino acid similarity to previously described resistance factors. Analyses of its genetic context suggest that has been decontextualized from the folate synthesis pathway in its original host, likely within the phylum Chloroflexi. Screening of 6489 metagenomic datasets revealed that sul4 is already widespread in seven countries across Asia and Europe.
Reference to the study:
Razavi M, Marathe NP, Gillings MR, Flach CF, Kristiansson E, Larsson DGJ. (2017). Discovery of the fourth mobile sulfonamide resistance gene. Microbiome. 5:160.