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

Abstract

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.

Presence, Distribution, and Molecular Epidemiology of Methicillin-ResistantStaphylococcus aureusin a Small Animal Teaching Hospital: A Year-Long Active Surveillance Targeting Dogs and Their Environment

“…Methicillinresistant status was confirmed by detection of the mecA gene and typing of the staphylococcal chromosomal cassette mec (SCCmec) simultaneously. Briefly, DNA was extracted using a boiling method, where a 100 lL bacterial suspension was heated for 7 min at 95°C (Kilic et al 2006). A multiplex PCR was performed (Milheirico et al 2007) with a few modifications.…”

Study of Community and Hospital Associated Methicillin Resistant Staphylococcus Aureus With Special Reference to Inducible Clindamycin Resistance in a Tertiary Care Hospital

“…Several authors have reported the prevalence of CA-MRSA ranging from 1 to 36 %. [21][22][23] Changing pattern of resistance of S. aureus makes its periodic surveillance mandatory. 24 We observed 34.42 % iMLSB in MRSA, which is correlates with study by P. Sreenivasulu Reddy et al who observed it in 46.2 % iMLSB in MRSA 11 and 15.78 % in CA-MRSA concoredence with Tandra Chadha , but less than Patel M et al reported 33 % CA-MRSA.…”

Staphylococcus aureus adquiridos en la comunidad: caracterización clínica, fenotípica y genotípica de aislados en niños paraguayos

“…Éste codifica una proteína de unión a penicilina, PBP2a, con actividad transpeptidasa responsable de la resistencia intrínseca a todos los b-lactámicos 2 . Además, se ha descrito que SARM-AC presenta diversos factores de virulencia, principalmente la leucocidina de Panton-Valentine (PVL-Panton Valentine leukocidin), cuyo gen codificante se ha visto asociado al SCCmec tipo IV y V, relacionados con los casos de SARM-AC 2,15,16 . Por lo general, en estos aislados, la resistencia a oxacilina no está acompañada por la resistencia a otros antimicrobianos, excepto algunas cepas donde se observa resistencia a eritromicina, clindamicina, cloranfenicol y gentamicina 15,17 .…”

“…Por lo general, en estos aislados, la resistencia a oxacilina no está acompañada por la resistencia a otros antimicrobianos, excepto algunas cepas donde se observa resistencia a eritromicina, clindamicina, cloranfenicol y gentamicina 15,17 . En la primera década del siglo veintiuno, diversas publicaciones comunicaron aislamiento de SARM-AC en población pediátrica alrededor del mundo 2,8,18 . En E.U.A., la prevalencia de SARM-AC varía dependiendo de la localización geográfica entre 26 .…”

“…taphylococcus aureus es un microorganismo pató-geno para el hombre, capaz de causar una multitud de infecciones con un amplio rango de gravedad, desde infecciones localizadas de piel e intoxicaciones alimentarias, hasta infecciones invasoras y potencialmente mortales como neumonía necrosante, osteomielitis y sepsis 1,2 . Su diversidad patogénica refleja su habilidad para colonizar exitosamente, adaptarse y sobrevivir en diferentes tejidos celulares durante la infección, lo que puede deberse a su capacidad de portar genes que le confieren resistencia a antimicrobianos, otros que codifican factores de virulencia, y su plasticidad genética; todo esto podría contribuir a una progresión más rápida y complicada de la enfermedad bajo determinados factores ambientales, ya que permiten una mejor adaptación al hospedero 3,4 .…”