title: Analysis of Staphylococcal Toxins and Clinical Outcomes of Methicillin-Resistant Staphylococcus aureus Bacteremia.
abstract: It is well known that methicillin-resistant Staphylococcus aureus (MRSA) produces many virulence factors, such as hemolysins, leukocidins, proteases, enterotoxins, exfoliative toxins, and immune-modulatory factors. The aim of study was to identify staphylococcal pathogenicity that may affect the prognosis of patients with MRSA bacteremia. We obtained 149 MRSA strains from blood cultures between January 2009 and December 2014 in our institution. We collected information on patient characteristics, laboratory data, staphylococcal toxin genes, and susceptibility of the strain toward anti-MRSA agent and analyzed them as factors contributing to 30-d mortality. The "survival" and "dead" groups consisted of 103 and 46 patients, respectively. Multiple logistic regression analysis showed a four-fold increase in the risk of mortality in patients exhibiting isolated MRSA with staphylococcal enterotoxins (SEs) genes as well as toxic shock syndrome toxin-1 (TSST-1) genes [odds ratio: 3.89; 95% confidence interval: 1.20-12.60; p=0.024]. Kaplan-Meier analysis also showed significantly higher mortality in patient with isolated MRSA with SEs and TSST-1 genes. After adjusting for confounders, the coexistence of SEs and TSST-1 were independently associated with the 30-d mortality compared with treatment and susceptibility. The coexistence of superantigenic toxin genes greatly affects the clinical course and prognosis of patients with MRSA bacteremia.
authors.affiliation: Division of Infection Control Sciences, Department of Pharmacotherapeutics, School of Pharmacy, Showa University.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Maeda
authors.forename: Hisashi
authors.initials: H
authors.lastname: Shoji
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Shirakura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Takuma
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Ugajin
authors.forename: Kunihiko
authors.initials: K
authors.lastname: Fukuchi
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Niki
authors.forename: Keiko
authors.initials: K
authors.lastname: Ishino
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology*; D001427:Bacterial Toxins / Q000235:genetics*; D005260:Female; D005798:Genes, Bacterial / Q000235:genetics; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011379:Prognosis; D013203:Staphylococcal Infections / Q000382:microbiology*; D018089:Superantigens / Q000235:genetics*; D016896:Treatment Outcome; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D018089:Superantigens; D037521:Virulence Factors