Novel Rearrangements in the Staphylococcal Cassette Chromosome Mec Type V Elements of Indian ST772 and ST672 Methicillin Resistant Staphylococcus aureus Strains

• Published in: PloS one Vol. 9; no. 4; p. e94293
• Main Authors: Balakuntla, Jayanth, Prabhakara, Sushma, Arakere, Gayathri
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.04.2014; Public Library of Science (PLoS)
• Subjects: Algorithms; Analysis; Animals; Bacteria; Biology and life sciences; Cassettes; Cattle; Chromosomes; Cloning; Cluster Analysis; DNA Primers; DNA sequencing; DNA, Bacterial; Drug resistance in microorganisms; Drug Resistance, Bacterial; Gene Rearrangement; Gene sequencing; Genes; Genetic aspects; Genome, Bacterial; Genomes; Genomics; Gram-positive bacteria; Health aspects; Humans; India; Inversions; Livestock; Mec gene; Medicine and Health Sciences; Methicillin; Methicillin-Resistant Staphylococcus aureus - genetics; Models, Genetic; Nucleotide sequencing; Oligonucleotide Array Sequence Analysis; Open Reading Frames; Penicillin; Physiological aspects; Primers; Recombination, Genetic; Sequence Alignment; Sequence Analysis, DNA; Staphylococcus aureus; Staphylococcus infections; India; Taiwan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0094293

Staphylococcus aureus is a commensal gram positive bacteria which causes severe and non severe infections in humans and livestock. In India, ST772 is a dominant and ST672 is an emerging clone of Staphylococcus aureus. Both cause serious human diseases, and carry type V SCCmec elements. The objective of this study was to characterize SCCmec type V elements of ST772 and ST672 because the usual PCR methods did not amplify all primers specific to the type. Whole genome sequencing analysis of seven ST772 and one ST672 S. aureus isolates revealed that the SCCmec elements of six of the ST772 isolates were the smallest of the extant type V elements and in addition have several other novel features. Only one ST772 isolate and the ST672 isolate carried bigger SCCmec cassettes which were composites carrying multiple ccrC genes. These cassettes had some similarities to type V SCCmec element from M013 isolate (ST59) from Taiwan in certain aspects. SCCmec elements of all Indian isolates had an inversion of the mec complex, similar to the bovine SCCmec type X. This study reveals that six out of seven ST772 S. aureus isolates have a novel type V (5C2) SCCmec element while one each of ST772 and ST672 isolates have a composite SCCmec type V element (5C2&5) formed by the integration of type V SCCmec into a MSSA carrying a SCC element, in addition to the mec gene complex inversions and extensive recombinations.