Antimicrobial Susceptibility Patterns and Staphylococcal Cassette Chromosome mec Types of, as Well as Panton-Valentine Leukocidin Occurrence among, Methicillin-Resistant Staphylococcus aureus Isolates from Children and Adults in Middle Tennessee

• Published in: Journal of Clinical Microbiology 2006-12, Vol.44 (12), p.4436-4440
• Main Authors: Kilic, Abdullah, Li, Haijing, Stratton, Charles W, Tang, Yi-Wei
• Format: Article
• Language: English
• Subjects: Adult; Anti-Bacterial Agents - pharmacology; Bacterial Toxins - genetics; Bacteriology; Biological and medical sciences; Child; Child, Preschool; Chromosomes, Bacterial - genetics; DNA, Bacterial - genetics; Exotoxins - genetics; Female; Fundamental and applied biological sciences. Psychology; Genotype; Humans; Infectious diseases; Leukocidins - genetics; Male; Medical sciences; Methicillin Resistance - genetics; Microbial Sensitivity Tests; Microbiology; Miscellaneous; Staphylococcal Infections - microbiology; Staphylococcus aureus; Staphylococcus aureus - classification; Staphylococcus aureus - drug effects; Staphylococcus aureus - genetics; Staphylococcus aureus - isolation & purification; Tennessee; Virulence Factors - genetics
• ISSN: 0095-1137; 1098-660X; 1098-5530
• DOI: 10.1128/JCM.01546-06

Antimicrobial susceptibility patterns, Panton-Valentine leukocidin (PVL) occurrence, and staphylococcal cassette chromosome mec (SCCmec) types in methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from children and adults at Vanderbilt University Medical Center during a 12-month period were evaluated. A total of 1,315 MRSA isolates were collected, of which 748 (36.7%) were recovered from children. Among all isolates, 448 (34.1%) were SCCmec-II, and 847 (64.4%) were SCCmec-IV. More SCCmec-IV isolates were recovered from children than SCCmec-II isolates (424 [50.1%] versus 50 [11.2%]; odds ration [OR] = 7.98; P < 0.000001). The PVL gene was detected in 93.6% of SCCmec-IV isolates, in contrast to 0.2% in SCCmec-II isolates. Within SCCmec-IV isolates, a statistically higher PVL occurrence was noticed in children (98.1%) than in adults (89.1%) (OR = 6.34; P < 0.000001). Overall, SCCmec-II strains showed greater resistance than SCCmec-IV strains to clindamycin, erythromycin, levofloxacin, gentamicin, rifampin, minocycline, and trimethoprim-sulfamethoxazole. Both SCCmec-II and SCCmec-IV strains recovered from adults were more resistant to these antibiotics than those recovered from children. SCCmec-II strains were predominantly recovered from the respiratory tract, whereas SCCmec-IV strains were predominantly recovered from skin, soft tissue, abscesses, and surgical wounds. These data indicate that SCCmec-IV MRSA isolates frequently infect children in middle Tennessee and are likely to harbor the PVL gene.