title: Typing of Panton-Valentine Leukocidin-Encoding Phages and lukSF-PV Gene Sequence Variation in Staphylococcus aureus from China.
abstract: Panton-Valentine leukocidin (PVL, encoded by lukSF-PV genes), a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in Staphylococcus aureus has been reported around the globe. However, the data on PVL-encoding phage types, lukSF-PV gene variation and chromosomal phage insertion sites for PVL-positive S. aureus are limited, especially in China. In order to obtain a more complete understanding of the molecular epidemiology of PVL-positive S. aureus, an integrated and modified PCR-based scheme was applied to detect the PVL-encoding phage types. Phage insertion locus and the lukSF-PV variant were determined by PCR and sequencing. Meanwhile, the genetic background was characterized by staphylococcal cassette chromosome mec (SCCmec) typing, staphylococcal protein A (spa) gene polymorphisms typing, pulsed-field gel electrophoresis (PFGE) typing, accessory gene regulator (agr) locus typing and multilocus sequence typing (MLST). Seventy eight (78/1175, 6.6%) isolates possessed the lukSF-PV genes and 59.0% (46/78) of PVL-positive strains belonged to CC59 lineage. Eight known different PVL-encoding phage types were detected, and Φ7247PVL/ΦST5967PVL (n = 13) and ΦPVL (n = 12) were the most prevalent among them. While 25 (25/78, 32.1%) isolates, belonging to ST30, and ST59 clones, were unable to be typed by the modified PCR-based scheme. Single nucleotide polymorphisms (SNPs) were identified at five locations in the lukSF-PV genes, two of which were non-synonymous. Maximum-likelihood tree analysis of attachment sites sequences detected six SNP profiles for attR and eight for attL, respectively. In conclusion, the PVL-positive S. aureus mainly harbored Φ7247PVL/ΦST5967PVL and ΦPVL in the regions studied. lukSF-PV gene sequences, PVL-encoding phages, and phage insertion locus generally varied with lineages. Moreover, PVL-positive clones that have emerged worldwide likely carry distinct phages.
authors.affiliation: Department of Clinical Laboratory, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University Shanghai, China.
authors.forename: Huanqiang
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University Shanghai, China.
authors.forename: Fupin
authors.initials: F
authors.lastname: Hu
authors.affiliation: Experimental Research Center, Shanghai People's Hospital of Putuo District Shanghai, China.
authors.forename: Shu
authors.initials: S
authors.lastname: Jin
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University Shanghai, China.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Xu
authors.affiliation: Experimental Research Center, Shanghai People's Hospital of Putuo District Shanghai, China.
authors.forename: Yuhan
authors.initials: Y
authors.lastname: Zou
authors.affiliation: Institute of Antibiotics, Huashan Hospital, Fudan University Shanghai, China.
authors.forename: Baixing
authors.initials: B
authors.lastname: Ding
authors.affiliation: Department of Clinical Laboratory, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University Shanghai, China.
authors.forename: Chunyan
authors.initials: C
authors.lastname: He
authors.affiliation: Department of Clinical Laboratory, The Third Hospital Affiliated to Nantong University Wuxi, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Gong
authors.affiliation: Department of Clinical Laboratory, Shanghai General Hospital, School of Medicine, Shanghai Jiaotong University Shanghai, China.
authors.forename: Qingzhong
authors.initials: Q
authors.lastname: Liu
keywords: Panton-Valentine leukocidin; Staphylococcus aureus; genetic background; phage typing; sequence variation