E. coli outbreak in a neonate intensive care unit in a general hospital in Mexico City

Nosocomial infections are a major cause of morbidity and mortality among neonates admitted to neonatal intensive care units (NICUs). The aim of this paper was to describe an outbreak of Escherichia coli among infants admitted to the NICU of the General Hospital “Dr. Manuel Gea Gonzalez” in May of 2008. The isolated E. coli strains were identified using standard biochemical methods. The susceptibilities of these strains were analysed by determining their minimal inhibitory concentrations. Following this, their molecular relationships to each other were assessed by pulsed field gel electrophoresis (PFGE) analysis and corroborated by serology. Twelve E. coli strains were isolated from blood, urine, or indwelling catheter samples from five cases of preterm infants within a 3-day period. Patients were admitted to the NICU of the general hospital and, during the outbreak, developed sepsis caused by E. coli. For four of the patients, the average age was 23 days, while one patient was a 3-month-old infant. Prior to sepsis, the infants had received assisted ventilation and hyperalimentation through a central venous catheter. Two profiles were observed by PFGE; profile A was identified as the outbreak’s cause and an outcome of cross-infection, while profile B showed genetic differences but serologically it was identified as part of the same serotype. We conclude that E. coli colonised the patients through horizontal transmission. A focal source of the microorganism in this outbreak was not identified, but cross-transmission through handling was the most probable route.     

A new small mammal assemblage from the M013 Terre Rosse fissure filling (Gargano,South-Eastern Italy)

The taxonomic study of the small mammal assemblage from fissure M013, sampled by a team of the University of Torino during the 2005–2009 excavations in the Dell’Erba Quarry (Apricena, Foggia) is presented. The assemblage includes the Echinosoricinae Apulogalerix cf. pusillus and the Crocidosoricinae ?Lartetium cf. dehmi; the Myomiminae species Stertomys simplex and Stertomys lyrifer; a new genus and species of Cricetodontinae and a single specimen of Hattomys cf. nazarii. Muridae include Mikrotia cf. parva, Mikrotia sp. 1 and a new genus and species of Murinae, phylogenetically related to Mikrotia. The occurrence of the new Murinae, the new Cricetodontinae, the two species of glirids and the Crocidosoricinae, as well as the absence of Apodemus and Prolagus, indicates M013 as the oldest Gargano's faunal assemblage known to date, despite the occurrence of Hattomys cf. nazarii, Mikrotia cf. parva and Mikrotia sp. 1, which most probably results from infiltrations from younger fissure fillings. The M013 assemblage is an absolute novelty for the Abruzzo-Apulian Palaeobioprovince, opening new perspectives for the timing and mode of dispersal of the forerunners of the Gargano fauna.     

Allelic Diversity and Its Implications for the Rate of Adaptation

Genetic variation is usually estimated empirically from statistics based on population gene frequencies, but alternative statistics based on allelic diversity (number of allelic types) can provide complementary information. There is a lack of knowledge, however, on the evolutionary implications attached to allelic-diversity measures, particularly in structured populations. In this article we simulated multiple scenarios of single and structured populations in which a quantitative trait subject to stabilizing selection is adapted to different fitness optima. By forcing a global change in the optima we evaluated which diversity variables are more strongly correlated with both short- and long-term adaptation to the new optima. We found that quantitative genetic variance components for the trait and gene-frequency-diversity measures are generally more strongly correlated with short-term response to selection, whereas allelic-diversity measures are more correlated with long-term and total response to selection. Thus, allelic-diversity variables are better predictors of long-term adaptation than gene-frequency variables. This observation is also extended to unlinked neutral markers as a result of the information they convey on the demographic population history. Diffusion approximations for the allelic-diversity measures in a finite island model under the infinite-allele neutral mutation model are also provided.     

Spatial variability of chlorophyll-a and abiotic variables in a river–floodplain system during different hydrological phases

Chlorophyll-a (Chl-a) and abiotic variables were measured in the main channel and floodplain waterbodies of the Middle Paraná River to analyse the system dynamics and to assess their spatial variability during different hydrological phases, including an extreme flood. We wanted to test that the flood does not always have a homogenising effect in a river–floodplain system. An explanatory model for Chl-a was performed according to Akaike’s Information Criterion (AIC), and the relation of water level with the coefficient of variation (CV) among sites for each variable was explored. The model explained 64% of Chl-a variability. Water level, depth:euphotic zone ratio (Z _d:Z _eu) (inverse correlation) and conductivity (direct correlation) were the significant explicative variables. The CV of Chl-a decreased with flood from the main channel to the floodplain, but for turbidity, Z _d:Z _eu, pH, dissolved oxygen, soluble reactive phosphorus and Chl-a:pheophytin-a ratio, it increased. However, within the floodplain, CV of turbidity, Z _d:Z _eu and pH decreased during flood. These suggest that the homogenising effect frequently observed during inundation cannot be generalised and that the floodplain may maintain its identity even during flood. The extreme flood and its overlap with the warm season and sedimentological pulse probably contributed to the heterogeneity in the spatial gradient.     

Fluorescent ligands for adenosine receptors

Interest is increasing in developing fluorescent ligands for characterization of adenosine receptors (ARs), which hold a promise of usefulness in the drug discovery process. The size of a strategically labeled AR ligand can be greatly increased after the attachment of a fluorophore. The choice of dye moiety (e.g. Alexa Fluor 488), attachment point and linker length can alter the selectivity and potency of the parent molecule. Fluorescent derivatives of adenosine agonists and antagonists (e.g. XAC and other heterocyclic antagonist scaffolds) have been synthesized and characterized pharmacologically. Some are useful AR probes for flow cytometry, fluorescence correlation spectroscopy, fluorescence microscopy, fluorescence polarization, fluorescence resonance energy transfer, and scanning confocal microscopy. Thus, the approach of fluorescent labeled GPCR ligands, including those for ARs, is a growing dynamic research field.     

Effects of (−)-epicatechin and derivatives on nitric oxide mediated induction of mitochondrial proteins

Impaired mitochondrial function represents an early manifestation of endothelial dysfunction and likely contributes to the development of cardiovascular diseases (CVD). The stimulation of mitochondrial function and/or biogenesis is seen as a means to improve the bioenergetic and metabolic status of cells and thus, reduce CVD. In this study we examined the capacity of the flavanol (?)-epicatechin and two novel derivatives to enhance mitochondrial function and protein levels in cultured bovine coronary artery endothelial cells. As nitric oxide production by endothelial cells is suspected in mediating mitochondria effects (including biogenesis), we also examined the dependence of responses on this molecule using an inhibitor of nitric oxide synthase. Results indicate that the flavanol (?)-epicatechin and derivatives are capable of stimulating mitochondrial function as assessed by citrate synthase activity as well as induction of structural (porin, mitofilin) and oxidative phosporylation protein levels (complex I and II). Effects were blocked by the use of the chemical inhibitor of the synthase thus, evidencing a role for nitric oxide in mediating these effects. The results observed indicate that the three agents are effective in enhancing mitochondria function and protein content. The effects noted for (?)-epicatechin may serve to explain the healthy effects on cardiometabolic risk ascribed to the consumption of cocoa products.     

Endophytic bacteria isolated from orchid and their potential to promote plant growth

Twelve endophytic bacteria were isolated from the meristem of in vitro Cymbidium eburneum orchid, and screened according to indole yield quantified by colorimetric assay, in vitro phosphate solubilization, and potential for plant growth promotion under greenhouse conditions. Eight strains with positive results were classified into the genus Paenibacillus by FAME profile, and evaluated for their ability to increase survival and promote the growth of in vitro germinated Cattleya loddigesii seedlings during the acclimatization process. The obtained results showed that all strains produced detectable indole levels and did not exhibit potential for solubilizing inorganic phosphate. Particularly, an increase of the total biomass and number of leaves was observed. Two strains of Paenibacillus macerans promoted plant growth under greenhouse conditions. None of the treatments had a deleterious effect on growth of inoculated plants. These results suggest that these bacterial effects could be potentially useful to promote plant growth during seedling acclimatization in orchid species other than the species of origin.     

Presence of osteoinductive factors in bovine colostrum

New approaches in the treatment of skeletal defects may benefit from the use of soluble biological factors. We previously standardized a derivative of bovine colostrum (SBCD), deprived of casein and fat and rich in cytokines. In the present study, we tested its possible use as an adjuvant in bone healing. SBCD contained factors involved in stromal cell stimulation and differentiation and induced cytokine production from stimulated mesenchymal stem cells (MSCs). In vitro, SBCD promoted proliferation, migration and, in association with osteogenic factors, osteogenic differentiation of osteoblastic and MSCs. In in vivo experiments of subcutaneous Matrigel injection in mice, SBCD plus hydroxyapatite, but not hydroxyapatite nor SBCD alone, induced recruitment of macrophages and stromal cells. After 60?days, plugs containing SBCD and hydroxyapatite were densely calcified and diffusely positive for osteocalcin, supporting the occurrence of an early osteogenic process. These results indicate that SBCD is a rich source of factors with osteoinductive properties.     

Identification of the infectious source of an unusual outbreak of histoplasmosis,in a hotel in Acapulco,state of Guerrero,Mexico

Three isolates of Histoplasma capsulatum were identified from mice lung, liver, and spleen inoculated with soil samples of the X hotel’s ornamental potted plants that had been fertilized with organic material known as compost. The presence of H. capsulatum in the original compost was detected using the dot-enzyme-linked immunosorbent assay. Nested-PCR, using a specific protein Hcp100 coding gene sequence, confirmed the fungal identification associated with an unusual histoplasmosis outbreak in Acapulco. Although, diversity between the H. capsulatum isolate from the hotel and some clinical isolates from Guerrero (positive controls) was observed using random amplification of polymorphic DNA based-PCR, sequence analyses of H-anti and ole fragment genes revealed a high homology (92–99%) between them.