Multicenter study of clinical non-ß-lactam-antibiotic susceptible MRSA strains: Genetic lineages and Panton-Valentine leukocidin (PVL) production.

INTRODUCTION: Methicillin-resistant Staphylococcus aureus (MRSA) is considered a major cause of healthcare-associated (HA) and community-acquired (CA) infections. Considering non-ß-lactam susceptibility as a potential marker for mecC-MRSA and CA-MRSA, the aim of this study was to determine the frequency and the associated genetic lineages of non-beta-lactam-antibiotic susceptible MRSA (NBLS-MRSA) strains in a multicenter study in Spain. METHODS: A collection of 45 NBLS-MRSA strains recovered in the period from January to June 2016 from 12 Spanish hospitals was analyzed. Molecular typing through spa-type characterization, agr group and multi-locus-sequence typing was performed. Methicillin-resistant genes (mecA and mecC) as well as immune evasion cluster (scn-chp-sak-sea-sep, considering scn gene as the marker of IEC system) and Panton-Valentine leukocidin (PVL) genes were determined with PCR/sequencing. RESULTS: The NBLS-MRSA phenotype was uncommon in the 12 hospitals analyzed (NBLS-MRSA/MRSA frequency: 0.3%-7.7%). All strains contained the mecA gene (and none contained mecC). Twenty-two different spa-types were detected among NBLS-MRSA strains, with spa-t008/agr-I the most prevalent (27%). The main clonal complexes were (CC/%): CC8/42.2%, CC5/33.3% and CC30/4.4%, with ST8 and ST5 as the main sequence types. The PVL toxin was present in 38% of strains (with spa-types t008, t024, t019, t044, t068, t318 and t3060). The IEC genes were detected in 78% of strains: IEC type-B (n=17), type-F (n=16), type-A (n=1) and type-E (n=1); 10 MRSA isolates were scn-negative. CONCLUSION: The NBLS-MRSA phenotype is uncommon in the analyzed hospitals; although no mecC-positive strains were detected, it could be a good marker for MRSA PVL-positive isolates (38%), frequently associated with CA-MRSA infections.

Tipos de spa no reportados en nuestro país en Staphylococcus aureus de pacientes adultos de un hospital escuela, Santa Fe, Argentina / Non reported spa types in our country in Staphylococcus aureus from adult patients of a school hospital, Santa Fe- Argentina

Staphylococcus aureus es un patógeno responsable de diversos cuadros clínicos. Los marcadores moleculares son útiles para el estudio de la epidemiología microbiana. Se estudiaron 22 aislamientos de S. aureus resistentes a meticilina (SARM) y 23 sensibles a meticilina (SASM) mediante mecA, cassette SCCmec, leucocidina de Panton Valentine (LPV) y polimorfismo spa; se analizaron datos de los pacientes. SASM predominó en muestras distintas de piel y partes blandas de internados, mientras SARM en partes blandas. Predominó el SCCmec tipo IV seguido del I. Se encontró baja presencia de LPV. En SARM hubo 11 tipos de spa diferentes, t019 fue el más frecuente y en pacientes ambulatorios. En SASM se hallaron 17 tipos con prevalencia del t189. El spa t002 estuvo presente en SASM y SARM. Se hallaron 11 tipos de spa no reportados en nuestro país.

Staphylococcus aureus is a pathogen associated a different kind of infection. Molecular markers are useful tools to study microbial epidemiology. Twenty two methicillin-resistant S. aureus (MRSA) and 23 methicillin-susceptible S. aureus (MSSA) were studied by mecA gene, SCCmec cassette, Panton Valentine leucocidin (PVL) and spa polymorphism. The clinical data patients were analyzed. MSSA was prevalent in samples different from skin and soft tissue (SST) and in hospitalized patients, whereas MRSA in SST. SCCmec type IV was predominant, followed spa; by type I. Low presence of PVL was found. In MRSA 11 different types of spa were detected, SCCmec; t019 was the most frequent and associated with outpatient, 17 types were found in MSSA and Panton Valentine t189 was prevalent. spa t002 was present in MSSA and MRSA. We found 11 types of spa not leucocidin reported in our country.

[Non reported spa types in our country in Staphylococcus aureus from adult patients of a school hospital, Santa Fe - Argentina]. / Tipos de spa no reportados en nuestro país en Staphylococcus aureus de pacientes adultos de un hospital escuela, Santa Fe, Argentina.

Staphylococcus aureus is a pathogen associated a different kind of infection. Molecular markers are useful tools to study microbial epidemiology. Twenty two methicillin-resistant S. aureus (MRSA) and 23 methicillin-susceptible S. aureus (MSSA) were studied by mecA gene, SCCmec cassette, Panton Valentine leucocidin (PVL) and spa polymorphism. The clinical data patients were analyzed. MSSA was prevalent in samples different from skin and soft tissue (SST) and in hospitalized patients, whereas MRSA in SST. SCCmec type IV was predominant, followed by type I. Low presence of PVL was found. In MRSA 11 different types of spa were detected, t019 was the most frequent and associated with outpatient, 17 types were found in MSSA and t189 was prevalent. spa t002 was present in MSSA and MRSA. We found 11 types of spa not reported in our country.

Neumonía adquirida en la comunidad por Staphylococcus aureus resistente a meticilina / Community-Acquired Pneumonia Due to Methicillin-Resistant Staphylococcus aureus

Los casos de infecciones causadas por Staphylococcus aureus resistente a meticilina han aumentado durante la última década. Dentro de ellas, la neumonía necrotizante (NN) adquirida en la comunidad se ha encontrado en pacientes jóvenes, sanos y sin factores de riesgo, lo que ha generado cuadros de evolución rápida y potencialmente mortales. En este artículo se discuten factores epidemiológicos, fisiopatológicos, de diagnóstico, tratamiento y pronóstico de la NN por Staphylococcus aureus resistente a meticilina adquirida en la comunidad.

The cases oí iníections caused by methicillirvresistant Stapkylococcus aureus have íncreased over the last decade, within them necrotizmg community'acquired pneumonía has been íound in healthy, young and with no risk factors patients, developing dínícal symptoms rapidly evolving and threatening. This artide discussed epidemiológica!, pathophysiological, diagnostic, treatment, and prognosis oí necrotizing pneumonía by Staphyiococcus aureus methicillin resistant communitV' acquired.

Frecuencia de staphylococcus aureus meticilino resistente y del factor de virulencia PVL en pacientes ambulatorios con infección de piel y partes blandas de Asunción, Paraguay / Frequency of methicillin-resistant staphylococcus aureusand PVL virulence factor in ambulatory patients with skinand soft tissue infections of Asuncion, Paraguay

Staphylococcus aureus (S. aureus) es actualmente el agente etiológico más frecuente en infecciones de piel y tejidos blandos. El S. aureus meticilino resistente (SAMR) aislado en infecciones de pacientes de la comunidad ha ido aumentando, constituyéndose en un problema de salud pública a nivel mundial. En Paraguay existen pocos registros sobre la meticilino resistencia y factores de virulencia a nivel comunitario, por lo que se realizó este estudio observacional descriptivo para determinar la frecuencia de SAMR y del factor de virulencia leucocidina de Panton Valentine (PVL-Panton Valentine leukocidin), así como el perfil de resistencia antimicrobiana acompañante a la meticilino resistencia en S. aureus aisladosde infecciones de piel y partes blandas de pacientes ambulatorios de dos laboratorios de Asunción, Paraguay, entre octubre de 2012 a febrero de 2014. La identificación bacteriana se realizó mediante técnicas microbiológicas convencionales y la susceptibilidad antimicrobiana por la prueba de difusión en disco. Elgen mecA y luk-PV fueron detectados por la técnica de PCR. De los 70 aislados de S. aureus estudiados, el 54,3% (38/70) fue SAMR tanto por método fenotípico como molecular. La frecuenciade PVL fue de 15,7% (11/70), siendo mayor en los SAMR (21%; 8/38) que en los SAMS (9,4%; 3/32). El 2,6% de los SAMR presentó resistencia a ciprofloxacina, no se observó multiresistencia en ningún aislado. Se encontró alta frecuencia de SAMR comparado con reportes previos en Paraguay. Se requiere fortalecer estrategias de vigilancia, prevención y control de la resistencia bacteriana en ambientes hospitalarios y de la comunidad.

Staphylococcus aureus (S. aureus) is currently the most common etiologic agentof skin and soft tissue infections. The isolation of methicillin-resistant S. aureus(MRSA) from infections of patients in the community has increased, becoming a public health problem worldwide. In Paraguay, there are few records aboutmethicillin resistance and virulence factors at community level. Therefore, this descriptive observational study was performed to determine the frequency of MRSA and factor virulence of Panton-Valentine leukocidin (PVL) as well as the antimicrobial resistance profile accompanying methicillin resistance in S. aureusisolated from skin and soft tissue infections in ambulatory patients from two laboratories of Asuncion, Paraguay from October, 2012 to February, 2014. The bacterial identification was performed using conventional microbiological techniques and the antimicrobial susceptibility was determined by disk diffusion. The mecA andluk-PV genes were detected by PCR technique. Out of the 70 S. aureus isolates studied, 54.3% (38/70) was SAMR by phenotypic and molecular methods. PVL frequency was 15.7% (11/70) being higher in MRSA (21%; 8/38) than in the SAMS (9.4%; 3/32), 2.6% of the MRSA was resistant to ciprofloxacin and multidrug resistance was not observed in any isolates. A high frequency of MRSA was found compared with previous reports in Paraguay. It is required to strengthen surveillance, prevention and control of bacterial resistance strategies in hospital and community environments.

Infección grave por Staphylococcus aureus meticilino sensible productor de leucocidina de Panton-Valentine: reportes de dos casos / Severe infection by methicillin sensitive Staphylococcus aureus producing Panton-Valentine leukocidin: reports of two cases

Staphylococcus aureus es uno de los principales agentes etiológicos de infecciones en niños provenientes de la comunidad y del ámbito hospitalario. La gravedad de estos cuadros se asocia a factores de virulencia, entre los que se encuentra la leucocidina de Panton-Valentine. Tanto Staphylococcus aureus resistente como sensible a la meticilina producen esta leucocidina, aunque con frecuencia variable. Presentamos a dos niños con infección grave por Staphylococcus aureus sensible a la meticilina productor de leucocidina de Panton-Valentine con complicaciones osteoarticulares y endovasculares. Es fundamental la sospecha diagnóstica, el tratamiento antibiótico adecuado y el manejo quirúrgico precoz para mejorar el abordaje de estas infecciones. Se debe mantener la vigilancia epidemiológica para detectar la frecuencia de las infecciones causadas por estas bacterias.

Staphylococcus aureus is a major etiologic agent of infections in children from the community and the hospital setting. The severity of these conditions is associated with virulence factors, including the Panton-Valentine leukocidin. Both methicillin resistant and sensitive Staphylococcus aureus produce this leukocidin although with varying frequency. We present two children with severe infection by sensitive Staphylococcus aureus producer of Panton-Valentine leukocidin with musculoskeletal and endovascular complications. It is essential the suspected diagnosis, appropriate antibiotic treatment and early surgical management to improve the approach of these infections. Epidemiological surveillance should be mantained to detect the frequency of infections caused by these bacteria.

Infección diseminada por Staphylococcus aureus positivo para leucocidina de Panton-Valentine en un niño / Disseminated Panton-Valentine Leukocidin-Positive Staphylococcus aureus infection in a child

La leucocidina de Panton-Valentine (LPV) es una exotoxina producida por muchas cepas de Staphylococcus aureus, y un importante factor de virulencia. Una infección por S. aureus positivo para LPV deriva en infecciones rápidas y graves de partes blandas y neumonía necrosante en adolescentes sanos, y la tasa de mortalidad es elevada. Presentamos el caso de un paciente de 12 años hospitalizado por fiebre, dificultad respiratoria y coxalgia en el que se identificó neumonía necrosante con embolia pulmonar séptica, absceso del psoas, celulitis y osteomielitis. En el hemocultivo del paciente se aisló S. aureus sensible a la meticilina (SASM) positivo para LPV.

Panton-Valentine leukocidin (PVL) is an exotoxin that is produced by many strains of Staphylococcus aureus, and an important virulence factor. A PVL-positive S. aureus infection leads to rapid and severe infections of soft tissue and necrotizing pneumonia in healthy adolescents, and has a high mortality. This case report included a 12-year-old male patient who admitted for fever, respiratory distress and hip pain and was identified with necrotizing pneumonia with septic pulmonary embolism, psoas abscess, cellulitis and osteomyelitis. The PVL positive methicillin-sensitive S. aureus (MSSA) was isolated in the patient blood culture.