Impact of early valve surgery on outcome of Staphylococcus aureus prosthetic valve infective endocarditis: analysis in the International Collaboration of Endocarditis-Prospective Cohort Study.

BACKGROUND: The impact of early valve surgery (EVS) on the outcome of Staphylococcus aureus (SA) prosthetic valve infective endocarditis (PVIE) is unresolved. The objective of this study was to evaluate the association between EVS, performed within the first 60 days of hospitalization, and outcome of SA PVIE within the International Collaboration on Endocarditis-Prospective Cohort Study. METHODS: Participants were enrolled between June 2000 and December 2006. Cox proportional hazards modeling that included surgery as a time-dependent covariate and propensity adjustment for likelihood to receive cardiac surgery was used to evaluate the impact of EVS and 1-year all-cause mortality on patients with definite left-sided S. aureus PVIE and no history of injection drug use. RESULTS: EVS was performed in 74 of the 168 (44.3%) patients. One-year mortality was significantly higher among patients with S. aureus PVIE than in patients with non-S. aureus PVIE (48.2% vs 32.9%; P = .003). Staphylococcus aureus PVIE patients who underwent EVS had a significantly lower 1-year mortality rate (33.8% vs 59.1%; P = .001). In multivariate, propensity-adjusted models, EVS was not associated with 1-year mortality (risk ratio, 0.67 [95% confidence interval, .39-1.15]; P = .15). CONCLUSIONS: In this prospective, multinational cohort of patients with S. aureus PVIE, EVS was not associated with reduced 1-year mortality. The decision to pursue EVS should be individualized for each patient, based upon infection-specific characteristics rather than solely upon the microbiology of the infection causing PVIE.

The Stealthy Superbug: the Role of Asymptomatic Enteric Carriage in Maintaining a Long-Term Hospital Outbreak of ST228 Methicillin-Resistant Staphylococcus aureus.

UNLABELLED: Whole-genome sequencing (WGS) of 228 isolates was used to elucidate the origin and dynamics of a long-term outbreak of methicillin-resistant Staphylococcus aureus (MRSA) sequence type 228 (ST228) SCCmec I that involved 1,600 patients in a tertiary care hospital between 2008 and 2012. Combining of the sequence data with detailed metadata on patient admission and movement confirmed that the outbreak was due to the transmission of a single clonal variant of ST228, rather than repeated introductions of this clone into the hospital. We note that this clone is significantly more frequently recovered from groin and rectal swabs than other clones (P < 0.0001) and is also significantly more transmissible between roommates (P < 0.01). Unrecognized MRSA carriers, together with movements of patients within the hospital, also seem to have played a major role. These atypical colonization and transmission dynamics can help explain how the outbreak was maintained over the long term. This "stealthy" asymptomatic colonization of the gut, combined with heightened transmissibility (potentially reflecting a role for environmental reservoirs), means the dynamics of this outbreak share some properties with enteric pathogens such as vancomycin-resistant enterococci or Clostridium difficile. IMPORTANCE: Using whole-genome sequencing, we showed that a large and prolonged outbreak of methicillin-resistant Staphylococcus aureus was due to the clonal spread of a specific strain with genetic elements adapted to the hospital environment. Unrecognized MRSA carriers, the movement of patients within the hospital, and the low detection with clinical specimens were also factors that played a role in this occurrence. The atypical colonization of the gut means the dynamics of this outbreak may share some properties with enteric pathogens.

Coevolution of Heliconius spp. and Passiflora spp. : a phylogenetic comparison

Although a substantial amount of research has been done on all aspects ofHeliconius biology and their ecological interactions with Passiflora, there has not hitherto been a phylogenetic examination of this association for coevolution. To test the HeliconiuslPassilfora association for coevolutionary congruence, phylogenies for each group were established and compared. The phylogeny for 14 species ofHeliconiinae from Costa Rica was based on combined sequence data from rRNA ITS 2 and partial EF-1a gene regions. For the Passifloraceae, 17 host plant species were utilized to establish a phylogeny based on tRNALeucine and ITS 1/5.8S1 ITS 2 sequence data. The phylogenies for both groups were largely in agreement with current classification (for Passifloraceae) and previously established phylogenies. Associations with the large subgenera Passiflora and Decaloba correspond with the two major Advanced Radiation groups in Heliconius. Although strict congruence above subgenus level was not observed, broad scale congruence was evident. One main host shift as well as other possible explanations for lack of strict congruence are suggested.

Trading nitrogen for carbon: Nitrogen and carbon translocation in a plant/fungal (Metarhizium spp.) symbiosis

While nitrogen is critical for all plants, they are unable to utilize organically bound nitrogen in soils. Therefore, the majority of plants obtain useable nitrogen through nitrogen fixing bacteria and the microbial decomposition of organic matter. In the majority of cases, symbiotic microorganisms directly furnish plant roots with inorganic forms of nitrogen. More than 80% of all land plants form intimate symbiotic relationships with root colonizing fungi. These common plant/fungal interactions have been defined largely through nutrient exchange, where the plant receives limiting soil nutrients, such as nitrogen, in exchange for plant derived carbon. Fungal endophytes are common plant colonizers. A number of these fungal species have a dual life cycle, meaning that they are not solely plant colonizers, but also saprophytes, insect pathogens, or plant pathogens. By using 15N labeled, Metarhizium infected, wax moth larvae (Galleria mellonella) in soil microcosms, I demonstrated that the common endophytic, insect pathogenic fungi Metarhizium spp. are able to infect living soil borne insects, and subsequently colonize plant roots and furnish ts plant host with useable, insect-derived nitrogen. In addition, I showed that another ecologically important, endophytic, insect pathogenic fungi, Beauveria bassiana, is able to transfer insect-derived nitrogen to its plant host. I demonstrated that these relationships between various plant species and endophytic, insect pathogenic fungi help to improve overall plant health. By using 13C-labeled CO2, added to airtight plant growth chambers, coupled with nuclear magnetic resosnance spectroscopy, I was able to track the movement of carbon from the atmosphere, into the plant, and finally into the root colonized fungal biomass. This indicates that Metarhizium exists in a symbiotic partnership with plants, where insect nitrogen is exchanged for plant carbon. Overall these studies provide the first evidence of nutrient exchange between an insect pathogenic fungus and plants, a relationship that has potentially useful implications on plant primary production, soil health, and overall ecosystem stability.

Caracterización de cepas del hongo comestible Pleurotus spp. en medios de cultivo y su evaluación en substratos lignocelulósicos forrajeros para la producción de carpóforos.

Tesis (Maestría en Ciencias con Especialidad en Producción Agrícola) UANL

Estudio morfoanatómico y algunos aspectos ecofisiológicos - de especies silvestres de frijol (Phaseolus spp) en Nuevo León

Tesis (Maestría en Ciencias con Especialidad en Botánica). UANL

Salmonella spp. en huevo comercial de dos empresas que surten al área metropólitana de Monterrey

Tesis (Maestría en Salud Pública Especialidad en Nutrición Comunitaria) UANL

Elección de las condiciones más adecuadas para la obtención de extractos de plantas superiores con actividad sobre una cepa de Staphylococcus aureus resistente

Tesis (Maestría en Ciencias con Orientación Terminal en Química Biomédica) UANL

Obtención de enterotoxinas B y C de Staphylococcus aureus e implentación de técnicas inmunoenzimáticas para su detección en productos lácteos

Tesis (Maestría en Ciencias con Especialidad en Microbiología Médica) U.A.N.L.

Transducción generalizada en cepas Rhizobium spp [por] Rosalía Anaya Elizalde

Tesis (Maestría en Ciencias con Especialidad en Microbiología) U.A.N.L.

Bionomía de Lutzomyia spp. (Diptera: psychodidae) vectores de Leishmaniasis cutánea localizada en el área endémica del ejido La Libertad, Escárcega, Campeche, México [por] Eduardo Alfonso Rebollar Téllez

Tesis (Maestro en Ciencias con Especialidad en Entomología Médica ) U.A.N.L.

Potencial de germinación del banco de germoplasma de Eucalyptus spp., en plantaciones del estado de Michoacán, México [por] Benjamín Villa Castillo

Tesis (Maestría en Ciencias Forestales) U.A.N.L.

Caracterización, ordenación y clasificación númerica en nopal (Opuntia spp.) mediante atributos morfológicos y físico-químicos por Mariano Molina Velázquez

Tesis (Maestría en Ciencias Agrícolas) U.A.N.L.

Detección de Listeria monocytogenes y Listeria spp en puntos críticos establecidos en una planta procesadora de productos congelados para rápido consumo

Tesis ( Maestro en Ciencias con Especialidad en Microbiología) U.A.N.L.

Estudio sobre el efecto de diferentes concentraciones de alcoholes primarios sobre la viabilidad de Staphylococcus aureus y escherichia coli y la integridad de sus respectivos esferoplastos

Tesis de María Alicia Suárez Semour (Maestro en Ciencias con especialidad en Microbiología Médica) U.A.N.L.