RESUMO
Introduction: The prevalence of Staphylococcus aureus in the community has increased, being the pediatric population the most affected. This fact highlights the need for epidemiological surveillance. Aim: To characterize clinical, phenotypic and genotypic isolates of S. aureus children’s samples with community-acquired infections, collected in hospitals of Asuncion and the Central Department, between November 2009 and December 2010. Materials and Methods: Descriptive and transverse analysis with analytical component. Clinical data collected by medical records, antibiotic susceptibility according to CLSI criteria and detection of mecA (encoding methicillin resistance) and luk-PV genes (encoding Panton Valentine leucocidin) by PCR using specific oligonucleotides. Results: 123 isolates of S. aureus, 76% came from skin and soft tissue infections and 20% from sepsis. 18.7% (n = 23) were resistant to methicillin (MRSA). The presence of the mecA gene, a variant there and the PVL was detected in 12.2 and 48 isolates respectively. 43% of MRSA (n = 10) was carrying luk-PV. The clinical and demographic differences between patients infected with MRSA or MSSA were not statistically significant. Discussion: This study constitutes the first phenotypic and genotypic characterization of S. aureus associated with pediatric patients in Paraguay.
Introducción: La prevalencia de infecciones por Staphylococcus aureus en la comunidad ha aumentado, siendo la población pediátrica la más afectada; poniendo de relieve la necesidad de una vigilancia epidemiológica. Objetivo: Caracterizar clínica, fenotípica y genotípicamente aislados de S. aureus de muestras de niños con infecciones adquiridas en la comunidad, recolectadas en hospitales de Asunción y el Departamento Central, entre noviembre de 2009 y diciembre de 2010. Materiales y Métodos: Estudio descriptivo de corte trasverso. Datos clínicos fueron recabados de fichas, la susceptibilidad a antimicrobianos se hizo según criterio del CLSI y la detección de genes mecA y luk-PV se realizó por RPC empleando oligonucleótidos específicos. Resultados: De 123 aislados de S. aureus, 76% provenían de infecciones de piel y tejidos blandos y 20% de pacientes con bacteriemias. 18,7% (n: 23) fueron resistentes a meticilina (SARM). Se detectó la presencia de genes mecA, una variante del mismo y luk-PV en 9,8%, 1,6 y 39% de los aislados, respectivamente. El 43% de los SARM (n: 10) fue portador de luk-PV. Las diferencias clínicas y demográficas entre pacientes infectados por SARM o SASM no fueron estadísticamente significativas. Discusión: Este estudio constituye la primera caracterización clínica, fenotípica y genotípica de S. aureus asociados a la comunidad en población pediátrica realizada en Paraguay.
Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Lactente , Pré-Escolar , Criança , Adolescente , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/genética , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Proteínas de Ligação às Penicilinas/genética , Exotoxinas/genética , Leucocidinas/genética , Paraguai , Fenótipo , Reação em Cadeia da Polimerase , Prevalência , Estudos Transversais , Infecções Comunitárias Adquiridas/microbiologia , GenótipoRESUMO
Context: Staphylococcus aureus is one of the most devastating human pathogen. The organism has a differential ability to spread and cause outbreak of infections. Characterization of these strains is important to control the spread of infection in the hospitals as well as in the community. Aim: To identify the currently existing phage groups of Staphylococcus aureus, their prevalence and resistance to antibiotics. Materials and Methods: Study was undertaken on 252 Staphylococcus aureus strains isolated from clinical samples. Strains were phage typed and their resistance to antibiotics was determined following standard microbiological procedures. Statistical Analysis: Chi square test was used to compare the antibiotic susceptibility between methicillin resistant Staph. aureus (MRSA) and methicillin sensitive S. aureus (MSSA) strains. Results: Prevalence of MRSA and MSSA strains was found to be 29.36% and 70.65% respectively. Of these 17.56% of MRSA and 40.44% of MSSA strains were community acquired. All the MSSA strains belonging to phage type 81 from the community were sensitive to all the antibiotics tested including clindamycin and were resistant to penicillin. Forty five percent strains of phage group III and 39% of non-typable MRSA strains from the hospital were resistant to multiple antibiotics. Conclusion: The study revealed that predominant phage group amongst MRSA strains was phage group III and amongst MSSA from the community was phage group NA (phage type 81). MSSA strains isolated from the community differed significantly from hospital strains in their phage type and antibiotic susceptibility. A good correlation was observed between community acquired strains of phage type 81 and sensitivity to gentamycin and clindamycin.