Antibiotic susceptibility and genomic variations in Staphylococcus aureus associated with Skin and Soft Tissue Infection (SSTI) disease groups

Abstract

BackgroundStaphylococcus aureus is associated with human skin and soft tissue infections (SSTIs); however, the involvement of virulence factors in different clinical presentations is unclear.MethodsWe analyzed methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) strains from Taiwan to determine correlations among the clinical characteristics of SSTIs, antimicrobial susceptibility and virulence factors of S. aureus with specific genetic backgrounds.ResultsWe identified 177 MRSA isolates and 130 MSSA isolates among the 307 SSTI-associated S. aureus isolates. Hospital-acquired (HA)- and community-acquired (CA)-MRSA isolates accounted for 61.6 % and 38.4 % of the isolates, respectively. Clinical presentations in SSTI patients differed significantly for the disease groups. Deep-seated MRSA infections presented with higher amputation rate than MSSA infections. MRSA isolates were all susceptible to linezolid, teicoplanin, and vancomycin, and >94 % of isolates were erythromycin- and clindamycin-resistant. Staphylococcal cassette chromosome (SCCmec) types IV, V, and VII were the most frequent in the CA-MRSA group (n = 68); types III, IV and V were the most frequent in the HA-MRSA group (n = 109). Panton-Valentine leukocidin (PVL) genes were significantly more frequent in CA-MRSA strains (75.0 %) than in HA-MRSA (33.0 %) and MSSA (24.6 %) and were found in 66.7 % (74/111) strains isolated from the abscess group. Exfoliatin A genes were more common in catheter-related exit-site MSSA infections (37.5 %) compared with other MSSA disease groups (P < 0.05). Exfoliatin B and superantigen exotoxin genes were uncommon in all SSTI disease types. Pulsotypes A (ST239), C, and D (ST59) were the predominant MRSA genotypes in deep-seated infections.ConclusionsIf not treated appropriately, deep-seated MRSA-associated infections present with higher amputation rates than deep-seated MSSA-associated infections. PVL-positive MRSA strains caused more frequently pus-forming lesions and less bacteremia and invasive diseases. Methods for discriminating CA-MRSA from HA-MRSA strains are now unreliable due to circulation of both ST 239 and ST 59 strains in the community and nosocomial settings. Initial antibiotic treatments should consider MRSA for patients with SSTIs in areas where MRSA is prevalent.

Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype

“…This pathogen is the etiological agent of several different systemic infections, affecting skin and soft tissue, as well as musculoskeletal and circulatory systems (Lowy, 1998; Changchien et al, 2016). It was reported that S. aureus can survive in human monocyte-derived macrophages (Kubica et al, 2008).…”

Typing of Methicillin-Resistant Staphylococcus aureus Isolate from Healthcare Workers in Larestan, Iran

“…S. aureus is a leading cause for wide range of mild skin infection to endocarditis or necrotizing pneumonia in the hospital and communities [1]. Methicillin, the first synthetic penicillin was used in 1961 for the treatment of S. aureus infections and methicillin resistant strains appeared from hospitals in this year.…”

Abscess cause by community acquired Methicillin Resistant Staphylococcus Aureus

“…Hastane kökenli MRSA enfeksiyonlarının aksine toplum kökenli MRSA suşlarında en önemli virulans faktörü Penton Valentine Lökosidin (PVL) sentezi kabul edilmektedir (6)(7)(8)(9) . PVL pozitif suşların doku nekrozu ve abse formasyonu ile ilişkili olduğu göz-lenmiştir (7) .…”

“…Elbette ki, trimetoprim sulfametaksazol, klindamisin ve uzun etkili tetrasiklinler kullanımı devam eden ancak yapılan çalışmalar ile tedavi başarısı tam olarak kanıtlanamamış antibiyotikler de tedavide yerini korumaktadır (1) . Klindamisin, HK-MRSA suşlarında yüksek direnç nedeniyle tercih edilmemektedir, ancak yapılan bazı çalışmalar TK-MRSA absesi olan çocuklarda etkili olduğu gös-terilmiştir (9,(14)(15)(16) . Hastamızda öncelikle ampisilin sülbaktam-klindamisin antibiyoterapileri uygulanmış olup, kültür sonucunda direnç görülmesi üzerine duyarlı olduğu teikoplanin tedavisine geçilmiştir.…”