Atypical manifestation in infection by methicillin-resistant Staphylococcus aureus carrier SCCmec IV and Panton-Valentine Leukocidin-producer in experimental sepsis model

Abstract

Staphylococcus aureus is considered an infectious agent of great clinical importance, responsible for many different types of infection. Strains of methicillin-resistant Staphylococcus aureus (MRSA), Panton-Valentine leukocidin producers, are considered more invasive, presenting clinical sequelae related to abscesses and infection in skin and soft tissues. The use of invasive techniques in hospital environment, such as the introduction of intravascular catheter in immunocompromised patients, has contributed to this microorganism spreading through the bloodstream, causing bacteremia, necrotizing pneumonia and increasing the number of septic patients in intensive care units with high mortality. In this report, atypical infections in Swiss mice using experimental model of sepsis was presented.

Pathological profiles of systemic infections by Panton‐Valentine leukocidin‐positive, methicillin‐resistant Staphylococcus aureus strains in a murine model

“…As a result of the inflammatory response, systemic infections may evolve to septic shock (Souza and Fontanetti 2006;Klevens et al 2007;Boles and Horswill 2008). Nevertheless, the most common infections occur in soft tissues (Lowy 1998;Kim et al 2014;Silva-Santana et al 2016;Silva-Santana et al 2017) presenting pathological characteristics such as purulent lesions and abscesses caused by infiltration of neutrophils in contaminated sites (Cheng et al 2009;Stearns-Kurosawa et al 2011;Kim et al 2014).…”

“…Previous studies indicated that 89% of S. aureus isolates is resistant to b-lactam antibiotics (methicillinresistant S. aureus, MRSA) (Amalaradjou and Venkitanarayanan 2014;Santana et al 2015). Nowadays, the recommended therapy includes vancomycin, linezolid and daptomycin for the treatment of infections caused by MRSA (Arbeit et al 2004;Liu et al 2011;Kim et al 2014;Silva-Santana et al 2016;Silva-Santana et al 2017).…”

“…The production of PVL has been more associated with strains classified as community-associated MRSA than nosocomial-acquired MRSA strains. The reason is that temperate bacteriophages such as PhiSLT, containing lukPV operon are most frequently observed in bacterial isolates presenting the chromosomal cassette SCCmec IV (Vandenesch et al 2003;Stearns-Kurosawa et al 2011;Silva-Santana et al 2016;Silva-Santana et al 2017). This operon is sporadically observed in bacterial isolates with the chromosomal cassette SCCmec V or VI and rarely associated with isolates containing the chromosomal cassette SCCmec types I, II or III (Diep et al 2006;Wardenburg et al 2008).…”

“…This operon is sporadically observed in bacterial isolates with the chromosomal cassette SCCmec V or VI and rarely associated with isolates containing the chromosomal cassette SCCmec types I, II or III (Diep et al 2006;Wardenburg et al 2008). PVL has been worldwide considered a major virulence determinant in MRSA isolates (Vandenesch et al 2003;Diep and Otto 2008;Silva-Santana et al 2016;Silva-Santana et al 2017), usually associated with skin abscess, soft tissues infections and necrotizing pneumonia (Lina et al 1999;Gillet et al 2002;Silva-Santana et al 2016;Silva-Santana et al 2017). Increasingly, PVL-producing MRSA have been reported in nosocomial infections, possibly initiated during invasive procedures.…”

“…Increasingly, PVL-producing MRSA have been reported in nosocomial infections, possibly initiated during invasive procedures. Severity of these infections may become intensified due to higher virulence levels of MRSA, especially in immunocompromised patients (Enright et al 2002;Maree et al 2007;Santana et al 2015;Silva-Santana et al 2016;Silva-Santana et al 2017). In hospital environment, pvl-positive S. aureus have been reported in cases of sepsis, presenting high fever, leukopenia, haemoptysis and pleural effusion, and may cause death in patients (Gillet et al 2002;Boyle-Vavra and Daum 2007;Stearns-Kurosawa et al 2011).…”