High virulence of methicillin resistant Staphylococcus aureus ST30-SCCmecIVc-spat019, the dominant community-associated clone in Argentina

Fernandez, Sebastian P.; Ledo, Camila; Lattar, Santiago M.; Llana, Mariángeles Noto; Bertelli, Andrea Cristina Mendoza; Gregorio, Sabrina Noelia Di; Sordelli, Daniel O.; Gómez, M. A.; Mollerach, Marta

doi:10.1016/j.ijmm.2017.05.003

Cited by 19 publications

(20 citation statements)

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“…Lesion swabs from children in care at the infectious diseases unit ( n = 12, 80% of the samples from this operative unit) are also characterised by high prevalence of the virulent ST45 clone [ 119 , 120 ] ( n = 8, three from lesion swabs; p value = 0.04) that is known to be associated with SSTIs [ 121 – 124 ]. The expected [ 125 ] association between PVL ( n = 37) and ST121 ( n = 12, nine PVL+; p value = 0.001) and ST30 ( n = 7, five PVL+; p value = 0.003) supports once again the observed increased virulence of these STs [ 117 , 118 , 126 , 127 ], which is partially in conflict with the hypothesis of lesion colonisation by commensal strains present in the skin microbiome [ 128 , 129 ].…”

Section: Resultssupporting

confidence: 56%

Whole-genome epidemiology, characterisation, and phylogenetic reconstruction of Staphylococcus aureus strains in a paediatric hospital

et al. 2018

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BackgroundStaphylococcus aureus is an opportunistic pathogen and a leading cause of nosocomial infections. It can acquire resistance to all the antibiotics that entered the clinics to date, and the World Health Organization defined it as a high-priority pathogen for research and development of new antibiotics. A deeper understanding of the genetic variability of S. aureus in clinical settings would lead to a better comprehension of its pathogenic potential and improved strategies to contrast its virulence and resistance. However, the number of comprehensive studies addressing clinical cohorts of S. aureus infections by simultaneously looking at the epidemiology, phylogenetic reconstruction, genomic characterisation, and transmission pathways of infective clones is currently low, thus limiting global surveillance and epidemiological monitoring.MethodsWe applied whole-genome shotgun sequencing (WGS) to 184 S. aureus isolates from 135 patients treated in different operative units of an Italian paediatric hospital over a timespan of 3 years, including both methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) from different infection types. We typed known and unknown clones from their genomes by multilocus sequence typing (MLST), Staphylococcal Cassette Chromosome mec (SCCmec), Staphylococcal protein A gene (spa), and Panton-Valentine Leukocidin (PVL), and we inferred their whole-genome phylogeny. We explored the prevalence of virulence and antibiotic resistance genes in our cohort, and the conservation of genes encoding vaccine candidates. We also performed a timed phylogenetic investigation for a potential outbreak of a newly emerging nosocomial clone.ResultsThe phylogeny of the 135 single-patient S. aureus isolates showed a high level of diversity, including 80 different lineages, and co-presence of local, global, livestock-associated, and hypervirulent clones. Five of these clones do not have representative genomes in public databases. Variability in the epidemiology is mirrored by variability in the SCCmec cassettes, with some novel variants of the type IV cassette carrying extra antibiotic resistances. Virulence and resistance genes were unevenly distributed across different clones and infection types, with highly resistant and lowly virulent clones showing strong association with chronic diseases, and highly virulent strains only reported in acute infections. Antigens included in vaccine formulations undergoing clinical trials were conserved at different levels in our cohort, with only a few highly prevalent genes fully conserved, potentially explaining the difficulty of developing a vaccine against S. aureus. We also found a recently diverged ST1-SCCmecIV-t127 PVL− clone suspected to be hospital-specific, but time-resolved integrative phylogenetic analysis refuted this hypothesis and suggested that this quickly emerging lineage was acquired independently by patients.ConclusionsWhole genome sequencing allowed us to study the epidemiology and genomic repertoire of S. aureus in a clin...

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Section: Resultssupporting

confidence: 56%

Whole-genome epidemiology, characterisation, and phylogenetic reconstruction of Staphylococcus aureus strains in a paediatric hospital

et al. 2018

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“…As mentioned before, the USA1100/ST30/CC30/SCCmecIV is a prevalent community clone in Brazil and other Latin American countries [2,4]. In our study, we found that all four isolates belonging to ST30/CC30, regardless their SCCmec type, presented the H2b PVL variant.…”

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confidence: 77%

Panton-Valentine leukocidin (PVL) isoforms among Staphylococcus aureus lineages isolated from hospitals in Rio de Janeiro, Brazil

et al. 2020

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Panton-Valentine leukocidin (PVL) is a Staphylococcus aureus virulence factor codified by lukSF-PV genes. Single-nucleotide polymorphisms (SNPs) at lukSF-PV genes can lead to two PVL sequence variants (R and H) generating different PVL isoforms. This study analyzed lukSF-PV genes SNPs among four different clonal lineages (STs/CC 1, 5, 8, and 30) of nine S. aureus isolated at Brazilian hospitals. The sequenced products showed SNPs at seven sites (positions 121, 470, 527, 663, 856, 1396, and 1729), leading to non-synonymous substitutions in all isolates investigated. Our findings showed new R and H isoforms variants in S. aureus isolated in Brazil and suggest a possible relationship between H2b isoform and the ST30/CC30 lineage. Keywords Staphylococcus aureus. Panton-Valentine leukocidin (PVL) isoforms. Brazilian lineages Panton-Valentine leukocidin (PVL) is a bicomponent and pore-forming toxin that targets phagocytes, leading to membrane damage and cell death in vitro, often associated with recurrent Staphylococcus aureus skin and soft tissue infections and necrotizing pneumonia [1]. PVL can be produced by both methicillin-susceptible (MSSA) and methicillinresistant S. aureus (MRSA) isolates [1, 2]. The USA300/ ST8 MRSA is the commonly PVL-positive lineage found in the USA [3], while in Latin American countries, including Brazil, the USA1100/ST30 MRSA is frequently reported [2, 4]. PVL-codifying genes, lukS-PV and lukF-PV, are carried by a temperate prophage and may be transferred from one isolate to another via phage transduction [5]. Although the PVL genes are considered highly conserved [6], it was demonstrated at least 22 points mutations or SNPs (single-nucleotide polymorphism) in both lukS-PV and lukF-PV [6-11] (Table 1). Based on the nucleotide substitution, the PVL proteins were classified in two major sequence variants of lukSF-PV, named as H or R variants [7]. Despite the recognized role of PVL on S. aureus disease severity [12], the influence of PVL isoforms on protein toxicity and disease outcome remains unknown. Molecular modeling studies suggested that the R isoform may alter pore formation and increase PVL leukotoxicity [7]. On the other hand, some authors suggested that the protein isoform does not influence PVL toxicity, since H and R isoforms could be found at similar frequencies among S. aureus isolates recovered from invasive diseases [6, 13]. However, it is important to point that mutations at virulence-related genes, besides increasing the molecular diversity of bacterial isolates, may lead to gain or loss of protein function. Due to the importance of PVL on S. aureus disease outcome [12], the comprehension of PVL structure and diversity is crucial to understand the microbial pathogenicity and may help the improvement of specific therapeutic drug target design. Moreover, there is no study regarding PVL isoforms of PVLpositive S. aureus isolates from Brazil. Thus, the present study aimed to determine the PVL isoforms of S. aureus previously isolated from different hospitals in Rio de Janeiro [...

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“…In Paraguay, we observe a similar trend: during 2009-2010 ST30-IV-t019 (54%) was predominant over ST5-IV-t311 (17%) in the second phase of this study (2012-2013), the difference was higher (65% and 5%, respectively) suggesting the replacement of ST5-IV-t311 by ST30-IV-t019 again. This replacement could be due to the presence or increased expression of certain virulence and adhesion factors, such as fibrinogen binding proteins (FnbPs), in the ST30 clone that determine greater success in establishing in certain niches and the subsequent dissemination to other tissues [34].…”

Section: Discussionmentioning

confidence: 99%

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones from Paraguayan children

Rodríguez

Salinas

Fernandez

et al. 2020

J Infect Dev Ctries

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Introduction: Staphylococcus aureus is considered one of the most important human pathogens, and its levels of resistance to methicillin have increased even in strains isolated from people without nosocomial risk factors. Molecular analysis is essential for understanding the patterns of dissemination. The objective of this study was to identify community-acquired methicillin-resistant S. aureus (CA-MRSA) clones that infected Paraguayan children patients in two periods of time. Methodology: An observational, descriptive study was designed to determine the genetic variability of 115 isolates of CA-MRSA recovered from children who attended four reference centers in Paraguay between 2009-2010 and 2012-2013. Results: The combined use of Pulsed Field Gel Electrophoresis (PFGE), Multi-Locus Sequencing Typing, Multi-Locus Variable Analysis (MLVA) and Spa typing techniques allowed the identification of two dominant clones: ST30-IV-t019 (77%) and ST5-IV-t311 (10%), and the establishment of the former as the leading cause of CA-MRSA infections in children during the study period. Conclusions: This is the first study that provides epidemiological information as well as microbiological and molecular characteristics of CA-MRSA isolates recovered from children from Asunción and the Central Department of Paraguay.

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High virulence of methicillin resistant Staphylococcus aureus ST30-SCCmecIVc-spat019, the dominant community-associated clone in Argentina

Cited by 19 publications

References 46 publications

Whole-genome epidemiology, characterisation, and phylogenetic reconstruction of Staphylococcus aureus strains in a paediatric hospital

Whole-genome epidemiology, characterisation, and phylogenetic reconstruction of Staphylococcus aureus strains in a paediatric hospital

Panton-Valentine leukocidin (PVL) isoforms among Staphylococcus aureus lineages isolated from hospitals in Rio de Janeiro, Brazil

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones from Paraguayan children

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