Integrative and Conjugative Elements and Prophage DNA as Carriers of Resistance Genes inStrains from Domestic Geese in Poland.

Abstract

Goose erysipelas is a serious problem in waterfowl breeding in Poland. However, knowledge of the characteristics ofstrains causing this disease is limited. In this study, the antimicrobial susceptibility and serotypes of fourstrains from domestic geese were determined, and their whole-genome sequences (WGSs) were analyzed to detect resistance genes, integrative and conjugative elements (ICEs), and prophage DNA. Sequence type and the presence of resistance genes and transposons were compared with 363 publicly availablestrains, as well as 13 strains of otherspecies. Four strains tested represented serotypes 2 and 5 and the MLST groups ST 4, 32, 242, and 243. Their assembled circular genomes ranged from 1.8 to 1.9 kb with a GC content of 36-37%; a small plasmid was detected in strain 1023. Strains 1023 and 267 were multidrug-resistant. The resistance genes detected in the genome of strain 1023 were,, andscluster, while strain 267 contained theandgenes. Mutations in thegene were detected in both strains. Thegene was embedded in a Tn-like transposon, which in strain 1023, together with the other resistance genes, was located on a large integrative and conjugative-like element of 130 kb designated as ICEEr1023. A minor integrative element of 74 kb was identified in strain 1012 (ICEEr1012). This work contributes to knowledge about the characteristics ofbacteria and, for the first time, reveals the occurrence ofandresistance genes in strains of this species. Phage infection appears to be responsible for the introduction of thegene into the genome of strain 267, while ICEs most likely play a key role in the spread of the other resistance genes identified in