title: Distinct bacteriophages encoding Panton-Valentine leukocidin (PVL) among international methicillin-resistant Staphylococcus aureus clones harboring PVL.
abstract: Genetically diverse community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) can harbor a bacteriophage encoding Panton-Valentine leukocidin (PVL) lysogenized into its chromosome (prophage). Six PVL phages (ΦPVL, Φ108PVL, ΦSLT, ΦSa2MW, ΦSa2USA, and ΦSa2958) are known, and single-nucleotide polymorphisms (SNPs) in the PVL genes have been reported. We sought to determine the distribution of lysogenized PVL phages among MRSA strains with PVL (PVL-MRSA strains), the PVL gene sequences, and the chromosomal phage insertion sites in 114 isolates comprising nine clones of PVL-MRSA that were selected for maximal underlying genetic diversity. The six PVL phages were identified by PCR; ΦSa2USA was present in the highest number of different lineages (multilocus sequence type clonal complex 1 [CC1], CC5, CC8, and sequence type 93 [ST93]) (n = 37 isolates). Analysis of 92 isolates confirmed that PVL phages inserted into the same chromosomal insertion locus in CC22, -30, and -80 but in a different locus in isolates of CC1, -5, -8, -59, and -88 and ST93 (and CC22 in two isolates). Within the two different loci, specific attachment motifs were found in all cases, although some limited inter- and intralineage sequence variation occurred. Overall, lineage-specific relationships between the PVL phage, the genes that encode the toxin, and the position at which the phage inserts into the host chromosome were identified. These analyses provide important insights into the microepidemiology of PVL-MRSA, will prove a valuable adjunct in outbreak investigation, and may help predict the emergence of new strains.
authors.affiliation: Staphylococcus Reference Unit, Laboratory of Healthcare Associated Infections, Centre for Infections, Health Protection Agency, 61 Colindale Avenue, London NW9 5EQ, United Kingdom. eve.boakes@hpa.org.uk
authors.forename: E
authors.initials: E
authors.lastname: Boakes
authors.forename: A M
authors.initials: AM
authors.lastname: Kearns
authors.forename: M
authors.initials: M
authors.lastname: Ganner
authors.forename: C
authors.initials: C
authors.lastname: Perry
authors.forename: R L
authors.initials: RL
authors.lastname: Hill
authors.forename: M J
authors.initials: MJ
authors.lastname: Ellington
mesh_terms: D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics*; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000235:genetics; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D005098:Exotoxins / Q000096:biosynthesis / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D007956:Leukocidins / Q000096:biosynthesis / Q000235:genetics*; D008242:Lysogeny; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification / Q000821:virology*; D008969:Molecular Sequence Data; D058885:Multilocus Sequence Typing; D039002:Prophages / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D013203:Staphylococcal Infections / Q000382:microbiology*; D013204:Staphylococcus Phages / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004279:DNA, Viral; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin