A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.

A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.

Impact of Mixed Infections of Gut Parasites Lotmaria passim and Nosema ceranae on the Lifespan and Immune-related Biomarkers in Apis mellifera.

Lotmaria passim currently appears to be the predominant trypanosome in honey bees worldwide. Although, the specific effects of L. passim by single or mixed with other gut parasites such as Nosema ceranae on honey bees' health is still unclear. We consequently measured bees' survival, parasite loads, the expression of antimicrobial peptides (AMPs) and vitellogenin gene. Thus, (1) bees naturally infected with L. passim, (2) healthy bees inoculated with Nosema ceranae, (3) bees naturally infected with L. passim and inoculated with N. ceranae and (4) healthy bees (control) were maintained under controlled conditions. Honey bees infected with N. ceranae or with mixed infections of L. passim and N. ceranae had significantly lower survival rates than the control group at 20 days post-inoculation (dpi). A competitive suppression was also detected, provided that the L. passim load was significantly affected by the presence of N. ceranae at 15 dpi. Expressions of the AMPs defensin and hymenoptaecin rapidly (two hours post-inoculation) increased in bees infected with N. ceranae and mixed infections. However, this effect was not continuous. In fact, expressions of abaecin, defensin, hymenoptaecin and vitellogenin decreased drastically at 15 dpi in bees with both single and mixed infections. The decrease in the expression of AMPs and vitellogenin throughout this period was consistent with the reduced survivals observed in this study, indicating that mixed infections of L. passim and N. ceranae, and even into a scenario of competition between them, may have a synergic effect on the survival and immune-related gene expressions (biomarkers) of worker bees.

Agua potable como posible fuente de brote de diarrea por Microsporidium spp. en pacientes inmunocomprometidos en un hospital pediátrico / The water supply of a pediatric hospital as a possible source of an outbreak of diarrhea due to Microsporidium spp. in immunocompromised patients

Introduction: The hospital water supply is a reservoir of a variety of potentially pathogenic microorganisms that can particularly affect children and immunocompromised patients. Potentially pathogenic Microsporidium spp. have been identified in water. Microsporidiosis is an emerging parasitic and opportunistic infection in immunocompromised patients. Objective and Method: to describe an outbreak of nosocomial diarrhea due to Microsporidium, species Encephalitozoon intestinalis. Results: Seven cases of E. intestinalis associated diarrhea were reported between november 2012 and february 2013, in a unit of immunocompromised patients in L. Calvo Mackenna Children's Hospital. Microsporidium spp. was found in the hospital water supply and water reservoir tank. Secondary cases were transmitted by contact. Control measures included contact precautions, not to use faucet water for hand washing, bottled water for drinking and water reservoir tank sanitation. Conclusions: This research is about a nosocomial outbreak associated with water supply. Water quality in Chilean hospitals is an unresolved issue, especially in immunocompromised patient areas. Compliance of cleaning and disinfection of water supply systems in hospitals must be ensured.

Introducción: Los sistemas de suministro de agua potable de los hospitales constituyen un reservorio de una variedad de microorganismos potencialmente patógenos que pueden afectar especialmente a niños y pacientes inmunocomprometidos. Especies de Microsporidium spp. potencialmente patógenos para el hombre han sido identificadas en el agua potable. La microsporidiosis es una infección parasitaria oportunista en pacientes inmunocomprometidos. Objetivos y Método: Describir un brote de diarrea nosocomial por Microsporidium de la especie Encephalitozoon intestinalis. Resultados: Se registraron siete casos de diarrea por E. intestinalis, entre noviembre de 2012 y febrero de 2013, en una unidad de pacientes inmunocomprometidos del Hospital de Niños Luis Calvo Mackenna, comprobándose la presencia de Microsporidium spp. abundante en el agua potable y estanques del hospital. Los casos secundarios pudieron transmitirse por contacto. Las medidas de control fueron precauciones de contacto, no usar agua de grifos para lavado de manos, ingesta de agua envasada y desinfección de estanques. Conclusiones: Esta investigación corresponde a un brote nosocomial transmitido por agua potable. La importancia de la calidad del agua en los hospitales de nuestro país es un tema no resuelto, especialmente en áreas que atienden pacientes inmunocomprometidos. Debe asegurarse el cumplimiento de limpieza y desinfección de los sistemas de suministro de agua en los hospitales.