Typing of Panton-Valentine leukocidin-encoding phages carried by methicillin-susceptible and methicillin-resistant Staphylococcus aureus from Italy

Abstract

Panton-Valentine leukocidin (PVL) is the hallmark of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) but can also be found in methicillin-susceptible S. aureus (MSSA) sharing pathogenic and epidemiological characteristics of CA-MRSA. PVL is encoded by two co-transcribed genes that are carried by different staphylococcal bacteriophages. We applied an extended PCR-based typing scheme for the identification of two morphological groups (elongated-head group and icosahedral-head group I phages) and specific PVL phage types in S. aureus isolates recovered in Italy. We examined 48 PVL-positive isolates (25 MSSA and 23 MRSA) collected from different hospital laboratories from April 2005 to May 2011. spa typing, multilocus sequence typing and staphylococcal cassette chromosome mec typing were applied to categorize the isolates. Phage typeability was 48.0% in MSSA and 91.3% in MRSA, highlighting the limitation of the PCR typing scheme when applied to PVL-positive MSSA. Five different PVL phages and two variants of a known phage were detected, the most prevalent being ΦSa2usa, recovered in 15 out of 48 (31.2%) isolates, and carried by both MSSA and MRSA belonging to CC8 and CC5. The recently described ΦTCH60 was recovered in four isolates. A PVL phage (ΦSa119) from an ST772 MRSA, that was not detected using the previous typing scheme, was sequenced, and new primers were designed for the identification of the icosahedral-head group II PVL phages present in ST772 and ST59 MRSA. A comprehensive PVL-phage typing can contribute to the understanding of the epidemiology and evolution of PVL-positive MSSA and MRSA.

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

“…However, there is no unified pattern for this scheme. To identify as many PVL-encoding phages as possible, this article summarized a strategy by integrating and modifying the expanded PCR-based scheme described previously (Ma et al, 2008 ; Boakes et al, 2011 ; Chen et al, 2013 ; Sanchini et al, 2014 ). Subsequently, by the usage of this strategy, fifteen-reaction PCR assay was carried out to detect 10 of the PVL-encoding phages (ΦPVL, Φ108PVL, Φtp310-1, ΦSa2958, ΦSa2mw, ΦSLT, ΦSa2USA, ΦTCH60, Φ7247PVL/ ΦST5967PVL, and ΦSa119) in S. aureus from China.…”

Corrigendum to ‘Panton-Valentine Leucocidin (PVL) Staphylococcus aureus a position statement from the International Society of Chemotherapy’ [International Journal of Antimicrobial Agents 51/1 (2018) 16-25]

“…Although defence mechanisms against phage infections in S. aureus have been described, including three restriction modification systems [23] and clustered regularly interspaced short palindromic repeats (CRISPR) loci [24], the PVL-associated genes, lukS-PV and lukF-PV, have been identified in many S. aureus genetic backgrounds including clonal complex (CC)1, CC5, CC6, CC8, CC22, CC30, CC45, CC59, ST772, CC75, CC80, CC88, CC93, CC121, CC152, ST154, CC398, ST1349, CC942 and ST2563 [25][26][27][28][29][30][31][32][33][34] lukS-PV and lukF-PV, are located on several temperate Siphoviridae phages including φSa2958, φSa2MW, φPVL, φ108PVL, φSLT, φ7247PVL, φSa119, φTCH60 and φSa2USA [25,26,35]. This family of double-stranded DNA viruses shares a long noncontractile tail and capsid with an isometric or an elongated shape [35].…”

“…The PVL-associated phages belong to group 1 (isometric head type), group 2 (elongated head type) or group 3 of Sfi21-like cossite Siphoviridae [35,36]. More variation in the phages carrying the PVL-associated genes is found in MSSA than in MRSA [26]. Phages in S. aureus can be induced as a consequence of antibiotic treatment with tobramycin, ciprofloxacin, trimethoprim/sulfamethoxazole (TMP/SMX), imipenem or trimethoprim [37][38][39], which in turn may facilitate the transmission of PVL-carrying phages among the S. aureus population.…”

“…Several PCR-based typing systems have been developed to identify the different PVL+ phages [26,40]. However these systems are not on their own very useful for outbreak control and epidemiological use.…”

First report of Panton–Valentine leukocidin-positive methicillin-susceptible Staphylococcus aureus ST88 harbouring ΦSa2usa isolated from refractory breast abscesses in Japan

“…Although the reason for the refractory symptoms in the present case was unknown, it was noted that the strain NK1119 possessed ΦSa2usa, which is usually found in ST8 community-acquired MRSA clone (USA300), which is highly virulent and spreading in the USA [5] , [6] . In contrast, ST88 strains have been described as having other PVL phages with a PVL gene of haplotype group H2 [4] , [14] . In Japan, ST8 MRSA appears to have been distributed in the community gradually since the late 2000s [15] , [16] , [17] .…”