Rosa Guillén

Microorganisms Associated With Pneumonia in Children <5 Years of Age in Developing and Emerging Countries: The GABRIEL Pneumonia Multicenter, Prospective, Case-Control Study

Summary In a multicenter, prospective case-control study involving 1758 children aged <5 years in developing and emerging countries, the main microorganisms associated with pneumonia were Streptococcus pneumoniae, human metapneumovirus, rhinovirus, and respiratory syncytial virus.

Viral and bacterial co-infection in severe pneumonia triggers innate immune responses and specifically enhances IP-10: a translational study

Mixed viral and bacterial infections are widely described in community-acquired pneumonia; however, the clinical implications of co-infection on the associated immunopathology remain poorly studied. In this study, microRNA, mRNA and cytokine/chemokine secretion profiling were investigated for human monocyte-derived macrophages infected in-vitro with Influenza virus A/H1N1 and/or Streptococcus pneumoniae. We observed that the in-vitro co-infection synergistically increased interferon-γ-induced protein-10 (CXCL10, IP-10) expression compared to the singly-infected cells conditions. We demonstrated that endogenous miRNA-200a-3p, whose expression was synergistically induced following co-infection, indirectly regulates CXCL10 expression by targeting suppressor of cytokine signaling-6 (SOCS-6), a well-known regulator of the JAK-STAT signaling pathway. Additionally, in a subsequent clinical pilot study, immunomodulators levels were evaluated in samples from 74 children (≤5 years-old) hospitalized with viral and/or bacterial community-acquired pneumonia. Clinically, among the 74 cases of pneumonia, patients with identified mixed-detection had significantly higher (3.6-fold) serum IP-10 levels than those with a single detection (P = 0.03), and were significantly associated with severe pneumonia (P < 0.01). This study demonstrates that viral and bacterial co-infection modulates the JAK-STAT signaling pathway and leads to exacerbated IP-10 expression, which could play a major role in the pathogenesis of pneumonia.

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.

CHARACTERIZATION OF THE CRYSTALLINE TEXTURE OF TUBES MADE OF ZIRCALOY-4.

In view of the critical character of the conditions of use of Zircaloy-4 cladding tubes in the nuclear industry, it is necessary to characterize them and try to inspect them as best as possible, especially insofar as concerns the mechanical and structural characteristics as crystalline texture. We studied, for each fabrication step, the crystalline texture of the material through incomplete pole figures (00.2). We observed a clear evolution from tangential tendency, for the initial product, to radial tendency of texture for the final product. This is in concordance with mechanical reduction coefficients used for pilgering. In the same way, a texture gradient is visible through the wall; this is probably due to the rolling process which leads to strain anisotropy.

[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.

Perfil de riesgo litogénico en pacientes con urolitiasis en Paraguay

The lithogenic risk profile is a graphical representation of metabolic factors and urinary saturation involved in the stone formation with their respective critical values. Aim: To determine the lithogenic risk profile in patients with urolithiasis. Material and Methods: Personal data such as anthropometric, history of diseases and family history of urolithiasis were recorded. Different compounds acting as promoters or inhibitors of crystallization were measured in serum and urine samples, and the data obtained were used to calculate urinary saturation using Equil software. Results: We included 30 men and 43 women with a median age of 45 (34-54) years. Overweight and family history of urolithiasis was reported in 63 and 32% respectively. Crystallization risk was detected in 74% of participants. The most common urinary abnormalities were hypocitraturia in 48% and hypercalciuria in 40%. Conclusions: The lithogenic profile revealed urinary saturation compatible with crystallization risk in 74% of the studied patients