AUTHOR=Zhao Huanqiang , Hu Fupin , Jin Shu , Xu Xiaogang , Zou Yuhan , Ding Baixing , He Chunyan , Gong Fang , Liu Qingzhong 

TITLE=Typing of Panton-Valentine Leukocidin-Encoding Phages and lukSF-PV Gene Sequence Variation in Staphylococcus aureus from China

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01200

DOI=10.3389/fmicb.2016.01200

ISSN=1664-302X

ABSTRACT=<p>Panton-Valentine leukocidin (PVL, encoded by <italic>lukSF-PV</italic> genes), a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in <italic>Staphylococcus aureus</italic> has been reported around the globe. However, the data on PVL-encoding phage types, <italic>lukSF-PV</italic> gene variation and chromosomal phage insertion sites for PVL-positive <italic>S. aureus</italic> are limited, especially in China. In order to obtain a more complete understanding of the molecular epidemiology of PVL-positive <italic>S. aureus</italic>, an integrated and modified PCR-based scheme was applied to detect the PVL-encoding phage types. Phage insertion locus and the <italic>lukSF-PV</italic> variant were determined by PCR and sequencing. Meanwhile, the genetic background was characterized by staphylococcal cassette chromosome <italic>mec</italic> (SCC<italic>mec</italic>) typing, staphylococcal protein A (<italic>spa</italic>) gene polymorphisms typing, pulsed-field gel electrophoresis (PFGE) typing, accessory gene regulator (<italic>agr</italic>) locus typing and multilocus sequence typing (MLST). Seventy eight (78/1175, 6.6%) isolates possessed the <italic>lukSF-PV</italic> 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 (<italic>n</italic> = 13) and ΦPVL (<italic>n</italic> = 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 <italic>lukSF-PV</italic> genes, two of which were non-synonymous. Maximum-likelihood tree analysis of attachment sites sequences detected six SNP profiles for <italic>attR</italic> and eight for <italic>attL</italic>, respectively. In conclusion, the PVL-positive <italic>S. aureus</italic> mainly harbored Φ7247PVL/ΦST5967PVL and ΦPVL in the regions studied. <italic>lukSF-PV</italic> 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.</p>