Pattrarat Chanchaithong1,2,3, Vincent Perreten1, Sybille Schwendener1. 1. Institute of Veterinary Bacteriology, Vetsuisse Faculty, University of Bern, Bern, Switzerland. 2. Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. 3. Diagnosis and Monitoring of Animal Pathogen Research Unit, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
Abstract
OBJECTIVES: To analyse the genetic context of mecB in two Macrococcus canis strains from dogs, compare the mecB-containing elements with those found in other Macrococcus and Staphylococcus species, and identify possible mobilizable mecB subunits. METHODS: Whole genomes of the M. canis strains Epi0076A and KM0218 were sequenced using next-generation sequencing technologies. Multiple PCRs and restriction analysis confirmed structures of mecB-containing elements, circularization and recombination of mecB subunits. RESULTS: Both M. canis strains contained novel composite pseudo (Ψ) staphylococcal cassette chromosome mec (SCCmec) elements. Integration site sequences for SCC flanked and subdivided composite ΨSCCmecEpi0076A (69569 bp) into ΨSCC1Epi0076A-ΨSCCmecEpi0076A-ΨSCC2Epi0076A and composite ΨSCCmecKM0218 (24554 bp) into ΨSCCKM0218-ΨSCCmecKM0218. Putative γ-haemolysin genes (hlgB and hlgC) were found at the 3' end of both composite elements. ΨSCCmecKM0218 contained a complete mecB gene complex (mecIm-mecR1m-mecB-blaZm) downstream of a new IS21-family member (ISMaca1). ΨSCCmecEpi0076A carried a blaZm-deleted mecB gene complex similar to that reported in 'Macrococcus goetzii' CCM4927T. A second mecB gene was found on the 81325 bp MDR plasmid pKM0218 in KM0218. This plasmid contained a complete Tn6045-associated mecB gene complex distinct from that of ΨSCCmecKM0218. pKM0218 was almost identical to the mecB-containing plasmid recently reported in Staphylococcus aureus (overall 99.96% nucleotide identity). Mobilization of mecB within an unconventional circularizable structure was observed in Epi0076A as well as chromosomal plasmid insertion via recombination of mecB operons in KM0218. CONCLUSIONS: Our findings provide evidence of both the continuing evolution of mecB-containing elements in macrococci and M. canis as a potential source of the mecB-containing plasmid found in staphylococci.
OBJECTIVES: To analyse the genetic context of mecB in two Macrococcus canis strains from dogs, compare the mecB-containing elements with those found in other Macrococcus and Staphylococcus species, and identify possible mobilizable mecB subunits. METHODS: Whole genomes of the M. canis strains Epi0076A and KM0218 were sequenced using next-generation sequencing technologies. Multiple PCRs and restriction analysis confirmed structures of mecB-containing elements, circularization and recombination of mecB subunits. RESULTS: Both M. canis strains contained novel composite pseudo (Ψ) staphylococcal cassette chromosome mec (SCCmec) elements. Integration site sequences for SCC flanked and subdivided composite ΨSCCmecEpi0076A (69569 bp) into ΨSCC1Epi0076A-ΨSCCmecEpi0076A-ΨSCC2Epi0076A and composite ΨSCCmecKM0218 (24554 bp) into ΨSCCKM0218-ΨSCCmecKM0218. Putative γ-haemolysin genes (hlgB and hlgC) were found at the 3' end of both composite elements. ΨSCCmecKM0218 contained a complete mecB gene complex (mecIm-mecR1m-mecB-blaZm) downstream of a new IS21-family member (ISMaca1). ΨSCCmecEpi0076A carried a blaZm-deleted mecB gene complex similar to that reported in 'Macrococcus goetzii' CCM4927T. A second mecB gene was found on the 81325 bp MDR plasmid pKM0218 in KM0218. This plasmid contained a complete Tn6045-associated mecB gene complex distinct from that of ΨSCCmecKM0218. pKM0218 was almost identical to the mecB-containing plasmid recently reported in Staphylococcus aureus (overall 99.96% nucleotide identity). Mobilization of mecB within an unconventional circularizable structure was observed in Epi0076A as well as chromosomal plasmid insertion via recombination of mecB operons in KM0218. CONCLUSIONS: Our findings provide evidence of both the continuing evolution of mecB-containing elements in macrococci and M. canis as a potential source of the mecB-containing plasmid found in staphylococci.
Authors: Janne S Schmidt; Stefan P Kuster; Aurélien Nigg; Valentina Dazio; Michael Brilhante; Helene Rohrbach; Odette J Bernasconi; Thomas Büdel; Edgar I Campos-Madueno; Stefanie Gobeli Brawand; Simone Schuller; Andrea Endimiani; Vincent Perreten; Barbara Willi Journal: Antimicrob Resist Infect Control Date: 2020-06-23 Impact factor: 4.887
Authors: Valentina Dazio; Aurélien Nigg; Janne S Schmidt; Michael Brilhante; Nico Mauri; Stephan P Kuster; Stefanie Gobeli Brawand; Gertraud Schüpbach-Regula; Barbara Willi; Andrea Endimiani; Vincent Perreten; Simone Schuller Journal: J Vet Intern Med Date: 2021-02-01 Impact factor: 3.333