TY - JOUR

T1 - Virulence Determinants in Staphylococcus aureus Clones Causing Osteomyelitis in Italy

AU - Pimentel de Araujo, Fernanda

AU - Pirolo, Mattia

AU - Monaco, Monica

AU - Del Grosso, Maria

AU - Ambretti, Simone

AU - Lombardo, Donatella

AU - Cassetti, Tiziana

AU - Gargiulo, Raffaele

AU - Riccobono, Eleonora

AU - Visca, Paolo

AU - Pantosti, Annalisa

N1 - Publisher Copyright: Copyright © 2022 Pimentel de Araujo, Pirolo, Monaco, Del Grosso, Ambretti, Lombardo, Cassetti, Gargiulo, Riccobono, Visca and Pantosti.

PY - 2022

Y1 - 2022

N2 - Staphylococcus aureus is the most common pathogen causing osteomyelitis (OM). The aim of this study was to explore the clonal complex (CC) distribution and the pattern of virulence determinants of S. aureus isolates from OM in Italy. Whole-genome sequencing was performed on 83 S. aureus isolates from OM cases in six hospitals. Antibiotic susceptibility tests showed that 30.1% of the isolates were methicillin-resistant S. aureus (MRSA). The most frequent CCs detected were CC22, CC5, CC8, CC30, and CC15, which represent the most common lineages circulating in Italian hospitals. MRSA were limited in the number of lineages (CC22, CC5, CC8, and CC1). Phylogenetic analysis followed the sequence type-CC groupings and revealed a non-uniform distribution of the isolates from the different hospitals. No significant difference in the mean number of virulence genes carried by MRSA or MSSA isolates was observed. Some virulence genes, namely cna, fib, fnbA, coa, lukD, lukE, sak, and tst, were correlated with the CC. However, different categories of virulence factors, such as adhesins, exoenzymes, and toxins, were frequently detected and unevenly distributed among all lineages. Indeed, each lineage carried a variable combination of virulence genes, likely reflecting functional redundancy, and arguing for the importance of those traits for the pathogenicity in OM. In conclusion, no specific genetic trait in the most frequent lineages could explain their high prevalence among OM isolates. Our findings highlight that CCs detected in OM isolates follow the epidemiology of S. aureus infections in the country. It is conceivable that any of the most common S. aureus CC can cause a variety of infections, including OM.

AB - Staphylococcus aureus is the most common pathogen causing osteomyelitis (OM). The aim of this study was to explore the clonal complex (CC) distribution and the pattern of virulence determinants of S. aureus isolates from OM in Italy. Whole-genome sequencing was performed on 83 S. aureus isolates from OM cases in six hospitals. Antibiotic susceptibility tests showed that 30.1% of the isolates were methicillin-resistant S. aureus (MRSA). The most frequent CCs detected were CC22, CC5, CC8, CC30, and CC15, which represent the most common lineages circulating in Italian hospitals. MRSA were limited in the number of lineages (CC22, CC5, CC8, and CC1). Phylogenetic analysis followed the sequence type-CC groupings and revealed a non-uniform distribution of the isolates from the different hospitals. No significant difference in the mean number of virulence genes carried by MRSA or MSSA isolates was observed. Some virulence genes, namely cna, fib, fnbA, coa, lukD, lukE, sak, and tst, were correlated with the CC. However, different categories of virulence factors, such as adhesins, exoenzymes, and toxins, were frequently detected and unevenly distributed among all lineages. Indeed, each lineage carried a variable combination of virulence genes, likely reflecting functional redundancy, and arguing for the importance of those traits for the pathogenicity in OM. In conclusion, no specific genetic trait in the most frequent lineages could explain their high prevalence among OM isolates. Our findings highlight that CCs detected in OM isolates follow the epidemiology of S. aureus infections in the country. It is conceivable that any of the most common S. aureus CC can cause a variety of infections, including OM.

KW - antibiotic resistance

KW - clones

KW - osteomyelitis

KW - Staphylococcus aureus

KW - virulence genes

KW - whole genome sequencing

U2 - 10.3389/fmicb.2022.846167

DO - 10.3389/fmicb.2022.846167

M3 - Journal article

C2 - 35308345

AN - SCOPUS:85127090509

VL - 13

JO - Frontiers in Microbiology

JF - Frontiers in Microbiology

SN - 1664-302X

M1 - 846167

ER -