Letizia Carpinelli

Staphylococcus coagulasa-negativa clínicamente significativos: Especies más frecuentes y factores de virulencia

BACKGROUND Coagulase-negative staphylococci have emerged as responsible for a large number of infections. However, it is often difficult to assess its pathogenic role or to discard it as a contaminant. AIM The goal of this study was to identify clinically significant coagulase-negative staphylococci to the species level and their virulence factors. Isolates came from patients consulting at the San Roque Laboratory from 2009 to 2011. MATERIAL AND METHODS Species identification was performed by De Paulis et al simplified method. Production of biofilm, hemolysins, lipases, lecithinases and DNase were determined by conventional methods; methicillin-resistance by diffusion method and mecA and Panton-Valentine genes, by multiplex PCR. RESULTS Out of 64 isolates, 40.6% were S. epidermidis; 20.3%, S. haemolyticus, and 15.6%, S. lugdunensis. Biofilm production was detected in 73.1% of S. epidermidis, 53.8% of S. haemolyticus and 40% of S. lugdunensis. mecA gene was identified in 69.2% of S. epidermidis, 92.3% of S. haemolyticus and none of S. lugdunensis. 83% of mecA (+) S. epidermidis isolates were biofilm producers as compared to 50% of the mecA (-). CONCLUSION The frequency of S. lugdunensis, the most virulent coagulase-negative staphylococci species, was relatively high. The main virulence factor in S. epidermidis was biofilm production, being higher in those resistant to methicillin.

Demodex spp en pacientes con blefaritis crónica

Introduccion: La blefaritis es una enfermedad muy comun en la practica oftalmologica, generalmente de curso cronico con exacerbaciones intermitentes. Varios estudios han relacionado la presencia del Demodex folliculorum con la blefaritis cronica, por su capacidad potencial de perpetuar el proceso inflamatorio a nivel folicular. La frecuencia de D. folliculorum varia de acuerdo a la poblacion. Objetivo: Determinar la presencia de Demodex spp y, caracterizar la microbiota ocular en pacientes con blefaritis cronica y dar a conocer estos resultados. Pacientes y Metodos: Las muestras fueron obtenidas de pacientes que consultaron en la Catedra de Oftalmologia del Hospital de Clinicas de la Universidad Nacional de Asuncion (UNA). Fueron incluidos en forma consecutiva 28 pacientes con blefaritis cronica que accedieron a participar en forma voluntaria en el estudio. Se extrajeron las pestanas del parpado superior e inferior de los pacientes para la busqueda inmediata del acaro por observacion directa bajo el microscopio optico. Para el cultivo de microorganismos se tomaron muestras del parpado con espatula de Kimura, las que fueron cultivadas en agar sangre y en medios de enriquecimiento e incubadas en CO2 al 5% a 35°C durante 72 h. Resultados: El sexo femenino fue mas frecuente (64%), el rango de edad estuvo entre 17 y 87 anos con una media de 37,9 ± 13,5. Se observo la presencia de Demodex sp en 54% y aislamiento de bacterias en 92,9%; Staphylococcus coagulasa negativa fue el mas frecuente (75%). No se encontraron asociaciones entre las caracteristicas socio-demograficas o clinicas y la presencia de Demodex sp. Conclusion: La alta infestacion por Demodex spp observada en los pacientes con blefaritis cronica coincide con otros estudios.

[Community-acquired Staphylococcus aureus isolated from Paraguayan children: clinical, phenotypic and genotypic characterization].

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 childrens 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.

Estudio comparativo de la eficacia de diversas modalidades terapéuticas en pacientes con blefaritis crónica

OBJECTIVE To compare the efficacy of 3 treatment options in patients with chronic blepharitis. METHODOLOGY An experimental, randomized, controlled study was conducted on 45 patients (female 67%; Mean age: 40.5 years) diagnosed with chronic blepharitis, in order to compare the effectiveness of three treatment options. Group 1: eyelid hygiene with neutral shampoo three times/day; group 2: neutral shampoo eyelid hygiene plus topical metronidazole gel 0.75% twice/day; group 3: neutral eyelid hygiene with shampoo plus neomycin 3.5% and polymyxin 10% antibiotic ointment with 0.5% dexamethasone 3 times/day. The symptoms and signs were assessed by assigning scores from 0: no symptoms and/or signs; 1: mild symptoms and/or signs, 2: moderate symptoms and/or signs; and 3: severe symptoms and/or signs. RESULTS A significant improvement was observed in the signs and symptoms in all 3 treatment groups. While groups 1 and 2 had more improvement in all variables studied (P<.05), Group 3 showed no clinical improvement for itching (P=.16), dry eye (P=.29), eyelashes falling (P=.16), and erythema at the eyelid margin (P=.29). CONCLUSIONS Shampoo eyelid hygiene neutral and neutral shampoo combined with the use of metronidazole gel reported better hygiene results than neutral shampoo lid with antibiotic ointment and neomycin and polymyxin dexamethasone.