Colonization by multidrug-resistant microorganisms of hospitalized newborns and their mothers in the neonatal unit context.

INTRODUCTION: The mother plays a fundamental role in the constitution and regulation of her child's healthy microbiota, however, preterm newborns are separated from their mothers soon after birth and transferred to Neonatal Intensive Care Units, being exposed the constant risk for the development of multidrug-resistant microorganisms' infections. The aim of this study was to explore the multidrug-resistant microorganism colonization of hospitalized babies and their mothers in the neonatal unit context. METHODOLOGY: A prospective case study conducted with hospitalized babies and their mothers in the Neonatal Unit at a university hospital. The sample was composed of 433 binomials (mother-child). Colonization culture samples were taken at the moment of the baby's discharge, via two swabs in the oral, nasal, axillary, inguinal, and rectal regions. RESULTS: The colonization incidence among the binomials, 30 (6.9%) were both colonized by multi-resistant microorganisms. Mothers of colonized babies (24.4%) demonstrated a higher chance of colonization in comparison to mothers of non-colonized babies (11.9%) (p = 0.002). Relationships were drawn between baby colonization and prematurity, extremely low birth weight, and non-exclusive maternal breastfeeding (p<0.05). ESBL-producing Gram-negative microorganisms were more frequent in the cultures of the binomials, with 35.9% of the babies colonized with Klebsiella spp. ESBL and 42.0% of the mothers with Escherichia coli ESBL. Furthermore, 50% of the binomials were colonized with E. coli ESBL. CONCLUSION: The prematurity, extremely low birth weight, and non-exclusive breastfeeding at hospital discharge were associated with baby colonization by multidrug-resistant microorganism. Furthermore, mothers of colonized children presented higher chances of colonization.

Nasal carriage of methicillin-resistant Staphylococcus aureus in university students.

In a study of university students, the percentage nasal carriage of Staphylococcus aureus was 40.8% (102/250). Of the isolates, MIC(50) of methicillin was 0.5 µg/mL and MIC(90) was 1 µg/mL. Six (5.8%) isolates were methicillin-resistant and carried the mecA gene. These results suggest that community-associated methicillin-resistant S. aureus may be spreading in Brazil.

Nasal carriage of methicillin-resistant Staphylococcus aureus in university students

In a study of university students, the percentage nasal carriage of Staphylococcus aureus was 40.8 percent (102/250). Of the isolates, MIC50 of methicillin was 0.5 µg/mL and MIC90 was 1 µg/mL. Six (5.8 percent) isolates were methicillin-resistant and carried the mecA gene. These results suggest that community-associated methicillin-resistant S. aureus may be spreading in Brazil.

Lack of association between genotypes and virulence factors in C. albicans strains isolated from vaginal secretion

The physiopathogenesis of vulvovaginal candidiasis (VVC) is still not completely elucidated. The objective of this study was to evaluate if there is a relationship between the different genotypes of Candida albicans, their main agent and the virulence of this yeast in vaginal isolates, and to check if there are laboratorial markers that can predict the ability of each isolate to develop VVC independently of symptoms. The production of exoenzymes protease, phospholipase and haemolysin, resistance to hydrogen peroxide, and the genotype were determined. Genotype A was predominant (75 percent), protease, phospholipase and haemolytic activity were highly expressed, and the majority of the yeasts were sensitive to H2O2 in 1 and 2 hours of exposure, suggesting that these factors are important in the virulence of vaginal isolates. However they did not have any correlation with the genotypes. The different isolates expressed similar virulence potential, suggesting that other factors relating to the yeasts and the host must participate in the development of the clinical disease.

A fisiopatogenia da candidíase vulvovaginal (CVV) não está completamente elucidada até o presente momento. O objetivo deste estudo foi avaliar se exite relação entre os diferentes genótipos de Candida albicans, seu principal agente, e a virulência desta levedura em isolados vaginais, e checar se existem marcadores laboratoriais que possam predizer a habilidade de cada isolado para desenvolver CVV independentemente dos sintomas. Foram determinados a produção de exoenzimas protease, fosfolipase and hemolisina, resistência ao peróxido de hidrogêncio, e genótipo. O genótipo A foi predominante (75 por cento), protease, fosfolipase e atividade hemolítica foram alevadamente expressos, e a maioria das leveduras foram sensíveis ao H2O2 em 1 e 2 horas de exposição, sugerindo que estes fatores são importantes na virulênciae de isolados vaginais. Entretanto, não houve nenhuma correlação com os genótipos. Os diferentes isolados expressaram potencial de virulência similares, sugerindo que outros fatores relacionados às leveduras e ao hospedeiro devem participar no desenvolvimento da doença clínica.

Differential gene expression during Trypanosoma cruzi metacyclogenesis

The transformation of epimastigotes into metacyclic trypomastigotes involves changes in the pattern of expressed genes, resulting in important morphological and functional differences between these developmental forms of Trypanosoma cruzi. In order to identify and characterize genes involved in triggering the metacyclogenesis process and in conferring to metacyclic trypomastigotes their stage specific biological properties, we have developed a method allowing the isolation of genes specifically expressed when comparing two close related cell populations (representation of differential expression or RDE). The method is based on the PCR amplification of gene sequences selected by hybridizing and subtracting the populations in such a way that after some cycles of hybridization-amplification genes specific to a given population are highly enriched. The use of this method in the analysis of differential gene expression during T. cruzi metacyclogenesis (6 hr and 24 hr of differentiation and metacyclic trypomastigotes) resulted in the isolation of several clones from each time point. Northern blot analysis showed that some genes are transiently expressed (6 hr and 24 hr differentiating cells), while others are present in differentiating cells and in metacyclic trypomastigotes. Nucleotide sequencing of six clones characterized so far showed that they do not display any homology to gene sequences available in the GeneBank.