Antibiotic susceptibility and genomic variations in Staphylococcus aureus associated with Skin and Soft Tissue Infection (SSTI) disease groups.
Staphylococcus aureus is associated with human skin and soft tissue infections (SSTIs); however, the involvement of virulence factors in different clinical presentations is unclear.



We 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.



We 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.



If 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.
Department of Plastic and Reconstructive Surgery, Chiayi Christian Hospital, 539 Jhongsiao Rd., Chiayi City, 60002, Taiwan, Republic of China.
Chih-Hsuan
CH
Changchien
Department of Microbiology, Immunology, and Biopharmaceuticals, National Chiayi University, No 300, University Road, Chiayi, 60004, Taiwan, Republic of China.
Shu-Wun
SW
Chen
Department of Plastic and Reconstructive Surgery, Chiayi Christian Hospital, 539 Jhongsiao Rd., Chiayi City, 60002, Taiwan, Republic of China.
Ying-Ying
YY
Chen
Department of Microbiology, Immunology, and Biopharmaceuticals, National Chiayi University, No 300, University Road, Chiayi, 60004, Taiwan, Republic of China. cschu@mail.ncyu.edu.tw.
Chishih
C
Chu
D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology; D001427:Bacterial Toxins / Q000235:genetics; D055499:Catheter-Related Infections / Q000382:microbiology; D002981:Clindamycin; D017714:Community-Acquired Infections / Q000382:microbiology; D003428:Cross Infection / Q000382:microbiology; D004917:Erythromycin; D005083:Exfoliatins / Q000235:genetics; D005098:Exotoxins / Q000235:genetics; D005260:Female; D005838:Genotype; D006801:Humans; D007956:Leukocidins / Q000235:genetics; D000069349:Linezolid; D008297:Male; D055624:Methicillin-Resistant Staphylococcus aureus / Q000235:genetics* / Q000302:isolation & purification; D008875:Middle Aged; D018461:Soft Tissue Infections / Q000382:microbiology*; D013203:Staphylococcal Infections / Q000382:microbiology; D013207:Staphylococcal Skin Infections / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000235:genetics / Q000302:isolation & purification; D018089:Superantigens / Q000235:genetics; D013624:Taiwan; D017334:Teicoplanin; D014640:Vancomycin; D037521:Virulence Factors / Q000235:genetics
D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D005083:Exfoliatins; D005098:Exotoxins; D007956:Leukocidins; C078284:Panton-Valentine leukocidin; D018089:Superantigens; D037521:Virulence Factors; D002981:Clindamycin; D017334:Teicoplanin; D004917:Erythromycin; D014640:Vancomycin; D000069349:Linezolid
MLST; MRSA; MSSA; Pulsotype; SSTI