Characterization of bacteriophage integrase gene families in <I>Staphylococcus aureus</I> phages of the International Typing Set
| Authors | |
|---|---|
| Year of publication | 2006 |
| Type | Article in Proceedings |
| Conference | 12th International Symposium on Staphylococci & Staphylococcal Infections |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.isssi2006.org/ |
| Field | Genetics and molecular biology |
| Keywords | Staphylococcus aureus; medical microbiology; molecular diagnostics |
| Description | Temperate phages of family Siphoviridae play an important role in biology of S. aureus strains, usually changing their phenotype as a result of lysogenic conversion associated with some virulence factors. The prophage content of S. aureus strains can be determined by the multiplex PCR assay targeting structural genes of head-tail modules described previously (Pantůček et al., Arch. Virol. 2004; 149:1689). However, this approach did not occasionally cover defective prophages. Therefore, we focused on development, validation and application of a PCR-based molecular assay for identification and classification of S. aureus phages based on the sequences of their integrase genes. The integrase genes were sequenced in 23 phages of the International Typing Set by using primers derived from a conserved regulatory sequence between the integrase and excisionase genes followed by primer walking. Additional integrase gene sequences were retrieved from the GenBank database. For designation of bacteriophage integrase gene families the updated classification scheme was used which denotes the previously sequenced phage and S. aureus genomes. In this work the analyzed S. aureus phages were classified on the basis of integrase gene homology into 8 families which dictates at the same time insertion sites on the chromosome by a novel multiplex PCR strategy. Eight PCR primer pairs designed for the integrase sequences Sa1 (phiETA), Sa2 (phiPVL), Sa3 (phiN315), Sa4 (phiSa4-MSSA476), Sa5 (phi11), Sa6 (phiL54a), Sa7 (phi96) and Sa8 (phi77) shown to be very effective and capable in a single assay to identify phage integrase genes present in bacterial genomes in different combinations. This technique was verified on 100 clinical isolates and shown to be a useful tool for the identification of lysogenic variants ordinarily existing in S. aureus clones. |
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