Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
1.
Appl Environ Microbiol ; 90(5): e0234923, 2024 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-38597602

RESUMEN

Piscine lactococcosis is a significant threat to cultured and wild fish populations worldwide. The disease typically presents as a per-acute to acute hemorrhagic septicemia causing high morbidity and mortality, recalcitrant to antimicrobial treatment or management interventions. Historically, the disease was attributed to the gram-positive pathogen Lactococcus garvieae. However, recent work has revealed three distinct lactococcosis-causing bacteria (LCB)-L. garvieae, L. petauri, and L. formosensis-which are phenotypically and genetically similar, leading to widespread misidentification. An update on our understanding of lactococcosis and improved methods for identification are urgently needed. To this end, we used representative isolates from each of the three LCB species to compare currently available and recently developed molecular and phenotypic typing assays, including whole-genome sequencing (WGS), end-point and quantitative PCR (qPCR) assays, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), API 20 Strep and Biolog systems, fatty acid methyl ester analysis (FAME), and Sensititre antimicrobial profiling. Apart from WGS, sequencing of the gyrB gene was the only method capable of consistent and accurate identification to the species and strain level. A qPCR assay based on a putative glycosyltransferase gene was also able to distinguish L. petauri from L. garvieae/formosensis. Biochemical tests and MALDI-TOF MS showed some species-specific patterns in sugar and fatty acid metabolism or protein profiles but should be complemented by additional analyses. The LCB demonstrated overlap in host and geographic range, but there were relevant differences in host specificity, regional prevalence, and antimicrobial susceptibility impacting disease treatment and prevention. IMPORTANCE: Lactococcosis affects a broad range of host species, including fish from cold, temperate, and warm freshwater or marine environments, as well as several terrestrial animals, including humans. As such, lactococcosis is a disease of concern for animal and ecosystem health. The disease is endemic in European and Asian aquaculture but is rapidly encroaching on ecologically and economically important fish populations across the Americas. Piscine lactococcosis is difficult to manage, with issues of vaccine escape, ineffective antimicrobial treatment, and the development of carrier fish or biofilms leading to recurrent outbreaks. Our understanding of the disease is also widely outdated. The accepted etiologic agent of lactococcosis is Lactococcus garvieae. However, historical misidentification has masked contributions from two additional species, L. petauri and L. formosensis, which are indistinguishable from L. garvieae by common diagnostic methods. This work is the first comprehensive characterization of all three agents and provides direct recommendations for species-specific diagnosis and management.


Asunto(s)
Enfermedades de los Peces , Infecciones por Bacterias Grampositivas , Lactococcus , Lactococcus/genética , Lactococcus/aislamiento & purificación , Lactococcus/clasificación , Animales , Enfermedades de los Peces/microbiología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/veterinaria , Peces/microbiología , Secuenciación Completa del Genoma , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
2.
GM Crops Food ; 15(1): 67-84, 2024 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-38507337

RESUMEN

The agricultural sugarcane residues, bagasse and straws, can be used for second-generation ethanol (2GE) production by the cellulose conversion into glucose (saccharification). However, the lignin content negatively impacts the saccharification process. This polymer is mainly composed of guaiacyl (G), hydroxyphenyl (H), and syringyl (S) units, the latter formed in the ferulate 5-hydroxylase (F5H) branch of the lignin biosynthesis pathway. We have generated transgenic lines overexpressing ShF5H1 under the control of the C4H (cinnamate 4-hydroxylase) rice promoter, which led to a significant increase of up to 160% in the S/G ratio and 63% in the saccharification efficiency in leaves. Nevertheless, the content of lignin was unchanged in this organ. In culms, neither the S/G ratio nor sucrose accumulation was altered, suggesting that ShF5H1 overexpression would not affect first-generation ethanol production. Interestingly, the bagasse showed a significantly higher fiber content. Our results indicate that the tissue-specific manipulation of the biosynthetic branch leading to S unit formation is industrially advantageous and has established a foundation for further studies aiming at refining lignin modifications. Thus, the ShF5H1 overexpression in sugarcane emerges as an efficient strategy to improve 2GE production from straw.


Asunto(s)
Lignina , Saccharum , Lignina/química , Lignina/metabolismo , Saccharum/genética , Saccharum/química , Saccharum/metabolismo , Oxigenasas de Función Mixta/metabolismo , Transcinamato 4-Monooxigenasa/metabolismo , Etanol/metabolismo
3.
J Aquat Anim Health ; 36(1): 3-15, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37859458

RESUMEN

OBJECTIVE: Columnaris disease is a leading cause of disease-related losses in the catfish industry of the southeastern United States. The term "columnaris-causing bacteria" (CCB) has been coined in reference to the four described species that cause columnaris disease: Flavobacterium columnare, F. covae, F. davisii, and F. oreochromis. Historically, F. columnare, F. covae, and F. davisii have been isolated from columnaris disease cases in the catfish industry; however, there is a lack of knowledge of which CCB species are most prevalent in farm-raised catfish. The current research objectives were to (1) sample columnaris disease cases from the U.S. catfish industry and identify the species of CCB involved and (2) determine the virulence of the four CCB species in Channel Catfish Ictalurus punctatus in controlled laboratory challenges. METHODS: Bacterial isolates or swabs of external lesions from catfish were collected from 259 columnaris disease cases in Mississippi and Alabama during 2015-2019. The DNA extracted from the samples was analyzed using a CCB-specific multiplex polymerase chain reaction to identify the CCB present in each diagnostic case. Channel Catfish were challenged by immersion with isolates belonging to each CCB species to determine virulence at ~28°C and 20°C. RESULT: Flavobacterium covae was identified as the predominant CCB species impacting the U.S. catfish industry, as it was present in 94.2% (n = 244) of diagnostic case submissions. Challenge experiments demonstrated that F. covae and F. oreochromis were highly virulent to Channel Catfish, with most isolates resulting in near 100% mortality. In contrast, F. columnare and F. davisii were less virulent, with most isolates resulting in less than 40% mortality. CONCLUSION: Collectively, these results demonstrate that F. covae is the predominant CCB in the U.S. catfish industry, and research aimed at developing new control and prevention strategies should target this bacterial species. The methods described herein can be used to continue monitoring the prevalence of CCB in the catfish industry and can be easily applied to other industries to identify which Flavobacterium species have the greatest impact.


Asunto(s)
Bagres , Enfermedades de los Peces , Infecciones por Flavobacteriaceae , Ictaluridae , Animales , Ictaluridae/microbiología , Flavobacterium/genética , Infecciones por Flavobacteriaceae/epidemiología , Infecciones por Flavobacteriaceae/veterinaria , Infecciones por Flavobacteriaceae/microbiología , Sudeste de Estados Unidos/epidemiología , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/microbiología
4.
Reproduction ; 165(2): 147-157, 2023 02 01.
Artículo en Inglés | MEDLINE | ID: mdl-36342662

RESUMEN

In brief: In the proestrus day, the neural and endocrine signals modulate ovarian function. This study shows vagus nerve plays a role in the multisynaptic pathways of communication between the suprachiasmatic nucleus and the ovaries where such neural information determines ovulation. Abstract: The suprachiasmatic nucleus (SCN) regulates the activity of several peripheral organs through a parasympathetic-sympathetic pathway. Previously, we demonstrated that atropine (ATR) microinjection in the right SCN of rats during proestrus blocks ovulation. In the present study, we analysed whether the vagus nerve is one of the neural pathways by which the SCN regulates ovulation. For this, CIIZ-V strain cyclic rats on the day of proestrus were microinjected with a saline solution (vehicle) or ATR in the right or left SCN, which was followed by ventral laparotomy or ipsilateral vagotomy to the microinjection side. Some animal groups were sacrificed (i) on the same day of the surgery to measure oestradiol, progesterone and luteinizing hormone (LH) levels or (ii) at 24 h after surgery to evaluate ovulation. The left vagotomy in rats microinjected with ATR in the left SCN did not modify ovulation. In rats with ATR microinjection in the right SCN, the right vagotomy increased the levels of steroids and LH on the proestrus and ovulatory response. The present results suggest that the right vagus nerve plays a role in the multisynaptic pathways of communication between the SCN and the ovaries and indicate that such neural information participates in the regulation of the oestradiol and progesterone surge, which triggers the preovulatory peak of LH and determines ovulation.


Asunto(s)
Hormona Luteinizante , Progesterona , Femenino , Ratas , Animales , Progesterona/metabolismo , Hormona Luteinizante/metabolismo , Núcleo Supraquiasmático/metabolismo , Ovulación/fisiología , Estradiol/metabolismo , Atropina/farmacología , Atropina/metabolismo , Nervio Vago/metabolismo
5.
Front Microbiol ; 14: 1303235, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38361579

RESUMEN

Erysipelothrix spp., including E. rhusiopathiae, are zoonotic bacterial pathogens that can cause morbidity and mortality in mammals, fish, reptiles, birds, and humans. The southern sea otter (SSO; Enhydra lutris nereis) is a federally-listed threatened species for which infectious disease is a major cause of mortality. We estimated the frequency of detection of these opportunistic pathogens in dead SSOs, described pathology associated with Erysipelothrix infections in SSOs, characterized the genetic diversity and antimicrobial susceptibility of SSO isolates, and evaluated the virulence of two novel Erysipelothrix isolates from SSOs using an in vivo fish model. From 1998 to 2021 Erysipelothrix spp. were isolated from six of >500 necropsied SSOs. Erysipelothrix spp. were isolated in pure culture from three cases, while the other three were mixed cultures. Bacterial septicemia was a primary or contributing cause of death in five of the six cases. Other pathology observed included suppurative lymphadenopathy, fibrinosuppurative arteritis with thrombosis and infarction, bilateral uveitis and endophthalmitis, hypopyon, petechia and ecchymoses, mucosal infarction, and suppurative meningoencephalitis and ventriculitis. Short to long slender Gram-positive or Gram-variable bacterial rods were identified within lesions, alone or with other opportunistic bacteria. All six SSO isolates had the spaA genotype-four isolates clustered with spaA E. rhusiopathiae strains from various terrestrial and marine animal hosts. Two isolates did not cluster with any known Erysipelothrix spp.; whole genome sequencing revealed a novel Erysipelothrix species and a novel E. rhusiopathiae subspecies. We propose the names Erysipelothrix enhydrae sp. nov. and Erysipelothrix rhusiopathiae ohloneorum ssp. nov. respectively. The type strains are E. enhydrae UCD-4322-04 and E. rhusiopathiae ohloneorum UCD-4724-06, respectively. Experimental injection of tiger barbs (Puntigrus tetrazona) resulted in infection and mortality from the two novel Erysipelothrix spp. Antimicrobial susceptibility testing of Erysipelothrix isolates from SSOs shows similar susceptibility profiles to isolates from other terrestrial and aquatic animals. This is the first description of the pathology, microbial characteristics, and genetic diversity of Erysipelothrix isolates recovered from diseased SSOs. Methods presented here can facilitate case recognition, aid characterization of Erysipelothrix isolates, and illustrate assessment of virulence using fish models.

6.
Syst Appl Microbiol ; 45(2): 126293, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35026686

RESUMEN

Flavobacterium columnare is the causative agent of columnaris disease in freshwater fish and four discrete genetic groups exist within the species, suggesting that the species designation requires revision. The present study determined the taxonomic status of the four genetic groups of F. columnare using polyphasic and phylogenomic approaches and included five representative isolates from each genetic group (including type strain ATCC 23463T; genetic group 1). 16S rRNA gene sequence analysis revealed genetic group 2 isolate AL-02-36T, genetic group 3 isolate 90-106T, and genetic group 4 isolate Costa Rica 04-02-TNT shared less than <98.8 % sequence identity to F. columnare ATCC 23463T. Phylogenetic analyses of 16S rRNA and gyrB genes using different methodologies demonstrated the four genetic groups formed well-supported and distinct clades within the genus Flavobacterium. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (GGDC) values between F. columnare ATCC 23463T, genetic group 2 isolate AL-02-36T, genetic group 3 isolate 90-106T, and genetic group 4 isolate Costa Rica 04-02-TNT were less than 90.84% and 42.7%, respectively. Biochemical and physiological characteristics were similar among the four genetic groups; however, quantitative differences in fatty acid profiles were detected and MALDI-TOF analyses demonstrated numerous distinguishing peaks unique to each genetic group. Chemotaxonomic, MALDI-TOF characterization and ANI/GGDC calculations afforded differentiation between the genetic groups, indicating each group is a discrete species. Herein, the names F. covae sp. nov. (AL-02-36T), F. davisii sp. nov. (90-106T), and F. oreochromis sp. nov. (Costa Rica 04-02-TNT) are proposed to represent genetic groups 2, 3, and 4, respectively.


Asunto(s)
Ácidos Grasos , Flavobacterium , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/análisis , Hibridación de Ácido Nucleico , Filogenia , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
7.
Int J Syst Evol Microbiol ; 70(2): 857-867, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31682217

RESUMEN

A recently described emergent disease of ornamental fish has been associated with an Erysipelothrix species positive for the surface protective antigen (spa) C gene. Whole genome sequencing was performed on five spaC Erysipelothrix isolates from diseased ornamental fish. In addition, these spaC Erysipelothrix isolates were compared to spaA-, spaB- and other spaC-positive Erysipelothrix species isolated from terrestrial and marine mammals, birds and fish using multi-locus sequence analysis (MLSA). The genomes of fish pathogenic spaC isolates were genetically distinct from Erysipelothrix rhusiopathiae, sharing 86.61-86.94 % average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of 31.6-32.2 %, but 99.01-99.11 % ANI and 90.8-91.9 % dDDH values with the uncharacterized spaC-positive Erysipelothrix sp. strain 2 isolated from swine. The findings indicate the spaC-positive fish and swine isolates are conspecific and represent a previously unrecognized taxon. While phylogenies inferred from MLSA sequences confirm this conclusion, slight genetic differences between the spaC fish isolates and swine strain 2 were indicated. Bath immersion challenge trials were conducted using tiger barbs (Puntigrus tetrazona) exposed by immersion to 107 c.f.u. ml-1 of three fish pathogenic spaC Erysipelothrix species, and three spaA and two spaB E. rhusiopathiae isolates as a model of infection. Thirty days post-challenge, cumulative mean percentage survival was 37 % for the spaA, 100 % for the spaB and 13 % for the spaC isolates, revealing differences in virulence among the various spa genotypes in fish. Genetic findings and observed differences in virulence demonstrate the fish pathogenic spaC isolates represent a novel species, for which the name Erysipelothrix piscisicarius sp. nov. is proposed. The type strain is E. piscisicarius 15TAL0474T (=NRRL B-65533T=ATCC-TSD-175T=DSM 110099T).


Asunto(s)
Cyprinidae/microbiología , Infecciones por Erysipelothrix/patología , Erysipelothrix/clasificación , Filogenia , Animales , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Erysipelothrix/aislamiento & purificación , Erysipelothrix/patogenicidad , Ácidos Grasos/química , Tipificación de Secuencias Multilocus , Hibridación de Ácido Nucleico , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Porcinos , Virulencia
8.
J Fish Dis ; 42(11): 1531-1542, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31469439

RESUMEN

Recent research has identified four distinct genetic groups among isolates of Flavobacterium columnare through multilocus phylogenetic analyses; however, there are no quick methods to determine the genotype of an isolate. The objective of this research was to develop a multiplex PCR to rapidly genotype F. columnare to genetic group. Comparative bacterial genomics was used to identify regions in the genomes unique to each genetic group, and primers were designed to specifically amplify different sized amplicons for each genetic group. The optimized assay was demonstrated to be specific for each genetic group and F. columnare, and no specific amplicons were generated using gDNA from a panel of other Flavobacterium spp. and bacterial fish pathogens. The analytical sensitivity of the assay ranged from 209 to 883 genome equivalents depending on the genetic group. The multiplex PCR was evaluated by genotyping a panel of 22 unknown F. columnare isolates and performing DNA sequencing of the dnaK gene in parallel. The results demonstrated 100% accordance between multiplex PCR results and assignment to genetic group via phylogenetic analysis. The multiplex PCR provides a useful tool for assigning an unknown isolate to genetic group and may be used to determine which genetic groups of F. columnare are circulating and most predominant in different aquaculture industries.


Asunto(s)
Flavobacterium/clasificación , Genotipo , Técnicas de Genotipaje/veterinaria , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Animales , Enfermedades de los Peces/diagnóstico , Infecciones por Flavobacteriaceae/diagnóstico , Infecciones por Flavobacteriaceae/veterinaria , Flavobacterium/genética , Flavobacterium/aislamiento & purificación , Técnicas de Genotipaje/métodos , Reacción en Cadena de la Polimerasa Multiplex/métodos , Filogenia
9.
Sci Rep ; 9(1): 12390, 2019 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-31455803

RESUMEN

Relaxor ferroelectrics (RF) are outstanding materials owing to their extraordinary dielectric, electromechanical, and electro-optical properties. Although their massive applications, they remain to be one of the most puzzling solid-state materials because understanding their structural local order and relaxation dynamics is being a long-term challenge in materials science. The so-called Vogel-Fulcher-Tamman (VFT) relation has been extensively used to parameterize the relaxation dynamics in RF, although no microscopic description has been firmly established for such empirical relation. Here, we show that VFT equation is not always a proper approach for describing the dielectric relaxation in RF. Based on the Adam-Gibbs model and the Grüneisen temperature index, a more general equation to disentangle the relaxation kinetic is proposed. This approach allows to a new formulation for the configurational entropy leading to a local structural heterogeneity related order parameter for RF. A new pathway to disentangle relaxation phenomena in other relaxor ferroics could have opened.

10.
Rev Salud Publica (Bogota) ; 20(1): 67-72, 2018.
Artículo en Español | MEDLINE | ID: mdl-30183887

RESUMEN

OBJECTIVE: To evaluate the effectiveness of mobile technology in the appropriate weight gain of pregnant women. MATERIALS AND METHODS: A quasi-experimental study. The sample included 117 pregnant women attending health facilities at la Dirección Regional de Salud (Diresa), Callao. Messages were sent to 58 pregnant women who formed the experimental group to improve their lifestyles and assistance to prenatal care (APC), while 59 pregnant women received routine education provided for pregnants. Messages were sent every three days. The nutritional status of the pregnant women was evaluated using the pre gestational BMI at the first visit of the APC. The weight gain was obtained from the difference between pre-gestational weight and weight recorded during the last controls. RESULTS: The adequate weight gain was 27.6% of intervened pregnancies and 25.4% in the non-intervened. The 79.3% pregnant had six or more NPC in the group intervened and 54.2% in the non-intervened. The weight gain was excessive in 5.1% in the non-intervened pregnant and 1.7% in the intervened. The highest percentage of pregnant women with adequate weight gain (32.0%) was observed in the intervened pregnancies with pre-gestacional overwhegith. CONCLUSIONS: There was no statistic difference in the use of mobile technology for a proper weight gain between both study groups. There were greater fulfillment of APC in intervened pregnancies compared to the non-intervened (p<0.05).


OBJETIVO: Evaluar la eficacia de la tecnología móvil en la ganancia adecuada de peso de las gestantes estudiadas. MATERIALES Y MÉTODOS: Estudio cuasi-experimental. Se incluyó a 117 gestantes que acudieron a establecimientos de salud de la Dirección Regional de Salud (Diresa), Callao. Se envió mensajes a 58 gestantes que conformaban el grupo experimental para mejorar sus estilos de vida y asistencia al control prenatal (CPN), mientras que 59 gestantes recibieron la educación rutinaria durante la gestación. Los mensajes se enviaron cada tres días. En la primera visita del control pre natal se evaluó el estado nutricional de las gestantes tomando como referencia el IMC pre gestacional. La ganancia de peso se obtuvo por diferencia entre el peso pre-gestacional y peso registrado durante los últimos controles. RESULTADOS: La ganancia de peso adecuada fue 27,6% de gestantes intervenidas y 25,4% en las no intervenidas. El 79,3% de gestantes tuvieron seis o más CPN en el grupo intervenido y 54,2% en las no intervenidas. La ganancia de peso fue excesiva en 5,1% en las gestantes no intervenidas y solo 1,7% en las intervenidas. El mayor porcentaje de gestantes con ganancia de peso adecuada (32,0%) se observó en las gestantes intervenidas con sobrepeso pre gestacional. CONCLUSIONES: No hubo diferencia estadística al usar la tecnología móvil para la adecuada ganancia de peso entre los grupos de estudio. Existió mayor cumplimiento de asistencia al CPN en el grupo de gestantes intervenidas comparado con el no intervenido (p<0,05).


Asunto(s)
Teléfono Celular , Promoción de la Salud/métodos , Aplicaciones Móviles , Atención Prenatal/métodos , Telemedicina/métodos , Aumento de Peso , Adolescente , Adulto , Femenino , Conductas Relacionadas con la Salud , Estilo de Vida Saludable , Humanos , Evaluación de Resultado en la Atención de Salud , Perú , Embarazo , Adulto Joven
11.
Appl Environ Microbiol ; 84(16)2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29915103

RESUMEN

Historically, piscine francisellosis in various warm-, temperate-, and cold-water fish hosts has been attributed to Francisella noatunensis From 2015 to 2016, an undescribed Francisella sp. was recovered during mortality events in cultured spotted rose snapper (Lutjanus guttatus) off the Pacific coast of Central America. Despite high mortality and emaciation, limited gross findings were observed in affected fish. Histological examination revealed multifocal granulomatous lesions, with the presence of numerous small, pleomorphic coccobacilli, predominantly in the peritoneum, spleen, kidneys, liver, pancreas, heart, and intestine. Sequencing of an ∼1,400-bp fragment of the 16S rRNA gene demonstrated these isolates to be most similar (99.9% identity) to Francisella sp. isolate TX077308 cultured from seawater in the Gulf of Mexico, while sharing <99% similarity to other Fransicella spp. Biochemical analysis, multilocus sequence comparisons of select housekeeping genes, repetitive extragenic palindromic PCR fingerprinting, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and fatty acid methyl ester analysis revealed marked differences between these isolates and other described members of the genus. Koch's postulates were fulfilled by experimental intracoelomic injection and immersion trials using Nile (Oreochromis niloticus) and blue (Oreochromis aureus) tilapia. Based on observed phenotypic and genotypic differences from recognized Francisella spp., the name Francisellamarina sp. nov. (NRRL B-65518) is proposed to accommodate these novel strains.IMPORTANCE Finfish aquaculture is the fastest growing global food production sector. Infectious disease, particularly emergent pathogens, pose a significant threat to established and nascent aquaculture industries worldwide. Herein, we characterize a novel pathogen isolated from mortality events in cultured spotted rose snapper in Central America. The bacteria recovered from these outbreaks were genetically and phenotypically dissimilar from other known Francisella spp. from fish, representing a previously unrecognized member of the genus Francisella, for which the name Francisella marina sp. nov. is proposed.


Asunto(s)
Cíclidos/microbiología , Enfermedades de los Peces/microbiología , Francisella/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/veterinaria , Animales , Acuicultura , América Central , ADN Bacteriano/genética , Enfermedades de los Peces/mortalidad , Francisella/genética , Infecciones por Bacterias Gramnegativas/mortalidad , Filogenia , ARN Ribosómico 16S/genética
12.
Front Microbiol ; 9: 452, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29593693

RESUMEN

Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the most prevalent fish diseases worldwide. An exceptionally high level of genetic diversity among isolates of F. columnare has long been recognized, whereby six established genomovars have been described to date. However, little has been done to quantify or characterize this diversity further in a systematic fashion. The objective of this research was to perform phylogenetic analyses of 16S rRNA and housekeeping gene sequences to decipher the genetic diversity of F. columnare. Fifty isolates and/or genomes of F. columnare, originating from diverse years, geographic locations, fish hosts, and representative of the six genomovars were analyzed in this study. A multilocus phylogenetic analysis (MLPA) of the 16S rRNA and six housekeeping genes supported four distinct F. columnare genetic groups. There were associations between genomovar and genetic group, but these relationships were imperfect indicating that genomovar assignment does not accurately reflect F. columnare genetic diversity. To expand the dataset, an additional 90 16S rRNA gene sequences were retrieved from GenBank and a phylogenetic analysis of this larger dataset also supported the establishment of four genetic groups. Examination of isolate historical data indicated biological relevance to the identified genetic diversity, with some genetic groups isolated preferentially from specific fish species or families. It is proposed that F. columnare isolates be assigned to the four genetic groups defined in this study rather than genomovar in order to facilitate a standard nomenclature across the scientific community. An increased understanding of which genetic groups are most prevalent in different regions and/or aquaculture industries may allow for the development of improved targeted control and treatment measures for columnaris disease.

13.
Rev. salud pública ; 20(1): 67-72, ene.-feb. 2018. tab
Artículo en Español | LILACS | ID: biblio-962094

RESUMEN

RESUMEN Objetivo Evaluar la eficacia de la tecnología móvil en la ganancia adecuada de peso de las gestantes estudiadas. Materiales y Métodos Estudio cuasi-experimental. Se incluyó a 117 gestantes que acudieron a establecimientos de salud de la Dirección Regional de Salud (Diresa), Callao. Se envió mensajes a 58 gestantes que conformaban el grupo experimental para mejorar sus estilos de vida y asistencia al control prenatal (CPN), mientras que 59 gestantes recibieron la educación rutinaria durante la gestación. Los mensajes se enviaron cada tres días. En la primera visita del control pre natal se evaluó el estado nutricional de las gestantes tomando como referencia el IMC pre gestacional. La ganancia de peso se obtuvo por diferencia entre el peso pre-gestacional y peso registrado durante los últimos controles. Resultados La ganancia de peso adecuada fue 27,6% de gestantes intervenidas y 25,4% en las no intervenidas. El 79,3% de gestantes tuvieron seis o más CPN en el grupo intervenido y 54,2% en las no intervenidas. La ganancia de peso fue excesiva en 5,1% en las gestantes no intervenidas y solo 1,7% en las intervenidas. El mayor porcentaje de gestantes con ganancia de peso adecuada (32,0%) se observó en las gestantes intervenidas con sobrepeso pre gestacional. Conclusiones No hubo diferencia estadística al usar la tecnología móvil para la adecuada ganancia de peso entre los grupos de estudio. Existió mayor cumplimiento de asistencia al CPN en el grupo de gestantes intervenidas comparado con el no intervenido (p<0,05).(AU)


ABSTRACT Objective To evaluate the effectiveness of mobile technology in the appropriate weight gain of pregnant women. Materials and Methods A quasi-experimental study. The sample included 117 pregnant women attending health facilities at la Dirección Regional de Salud (Diresa), Callao. Messages were sent to 58 pregnant women who formed the experimental group to improve their lifestyles and assistance to prenatal care (APC), while 59 pregnant women received routine education provided for pregnants. Messages were sent every three days. The nutritional status of the pregnant women was evaluated using the pre gestational BMI at the first visit of the APC. The weight gain was obtained from the difference between pre-gestational weight and weight recorded during the last controls. Results The adequate weight gain was 27.6% of intervened pregnancies and 25.4% in the non-intervened. The 79.3% pregnant had six or more NPC in the group intervened and 54.2% in the non-intervened. The weight gain was excessive in 5.1% in the non-intervened pregnant and 1.7% in the intervened. The highest percentage of pregnant women with adequate weight gain (32.0%) was observed in the intervened pregnancies with pre-gestacional overwhegith. Conclusions There was no statistic difference in the use of mobile technology for a proper weight gain between both study groups. There were greater fulfillment of APC in intervened pregnancies compared to the non-intervened (p<0.05).(AU)


Asunto(s)
Humanos , Femenino , Embarazo , Atención Prenatal/métodos , Obesidad Materna/epidemiología , Perú/epidemiología , Teléfono Celular/instrumentación , Ensayos Clínicos Controlados no Aleatorios como Asunto
14.
J Clin Microbiol ; 55(12): 3466-3491, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-28978684

RESUMEN

Edwardsiella spp. are responsible for significant losses in important wild and cultured fish species worldwide. Recent phylogenomic investigations have determined that bacteria historically classified as Edwardsiella tarda actually represent three genetically distinct yet phenotypically ambiguous taxa with various degrees of pathogenicity in different hosts. Previous recognition of these taxa was hampered by the lack of a distinguishing phenotypic character. Commercial test panel configurations are relatively constant over time, and as new species are defined, appropriate discriminatory tests may not be present in current test panel arrangements. While phenobiochemical tests fail to discriminate between these taxa, data presented here revealed discriminatory peaks for each Edwardsiella species using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) methodology, suggesting that MALDI-TOF can offer rapid, reliable identification in line with current systematic classifications. Furthermore, a multiplex PCR assay was validated for rapid molecular differentiation of the Edwardsiella spp. affecting fish. Moreover, the limitations of relying on partial 16S rRNA for discrimination of Edwardsiella spp. and advantages of employing alternative single-copy genes gyrB and sodB for molecular identification and classification of Edwardsiella were demonstrated. Last, sodB sequencing confirmed that isolates previously defined as typical motile fish-pathogenic E. tarda are synonymous with Edwardsiella piscicida, while atypical nonmotile fish-pathogenic E. tarda isolates are equivalent to Edwardsiella anguillarum Fish-nonpathogenic E. tarda isolates are consistent with E. tarda as it is currently defined. These analyses help deconvolute the scientific literature regarding these organisms and provide baseline information to better facilitate proper taxonomic assignment and minimize erroneous identifications of Edwardsiella isolates in clinical and research settings.


Asunto(s)
Edwardsiella tarda/clasificación , Edwardsiella tarda/aislamiento & purificación , Infecciones por Enterobacteriaceae/veterinaria , Enfermedades de los Peces/microbiología , Genotipo , Fenotipo , Animales , Proteínas Bacterianas/genética , Girasa de ADN/genética , Edwardsiella tarda/química , Edwardsiella tarda/genética , Infecciones por Enterobacteriaceae/diagnóstico , Infecciones por Enterobacteriaceae/microbiología , Enfermedades de los Peces/diagnóstico , Reacción en Cadena de la Polimerasa Multiplex/métodos , Filogeografía , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN/métodos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodos , Superóxido Dismutasa/genética
15.
Appl Environ Microbiol ; 83(23)2017 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-28939608

RESUMEN

Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes, adhesins, and proteins involved in gliding motility. The F. columnare genome has all of the genes needed to encode a T9SS. gldN, which encodes a core component of the T9SS, was deleted in wild-type strains of F. columnare The F. columnare ΔgldN mutants were deficient in the secretion of several extracellular proteins and lacked gliding motility. The ΔgldN mutants exhibited reduced virulence in zebrafish, channel catfish, and rainbow trout, and complementation restored virulence. PorV is required for the secretion of a subset of proteins targeted to the T9SS. An F. columnare ΔporV mutant retained gliding motility but exhibited reduced virulence. Cell-free spent media from exponentially growing cultures of wild-type and complemented strains caused rapid mortality, but spent media from ΔgldN and ΔporV mutants did not, suggesting that soluble toxins are secreted by the T9SS.IMPORTANCE Columnaris disease, caused by F. columnare, is a major problem for freshwater aquaculture. Little is known regarding the virulence factors produced by F. columnare, and control measures are limited. Analysis of targeted gene deletion mutants revealed the importance of the type IX protein secretion system (T9SS) and of secreted toxins in F. columnare virulence. T9SSs are common in members of the phylum Bacteroidetes and likely contribute to the virulence of other animal and human pathogens.


Asunto(s)
Proteínas Bacterianas/metabolismo , Sistemas de Secreción Bacterianos/metabolismo , Enfermedades de los Peces/microbiología , Infecciones por Flavobacteriaceae/veterinaria , Flavobacterium/metabolismo , Flavobacterium/patogenicidad , Animales , Proteínas Bacterianas/genética , Sistemas de Secreción Bacterianos/genética , Infecciones por Flavobacteriaceae/microbiología , Flavobacterium/genética , Ictaluridae/microbiología , Oncorhynchus mykiss/microbiología , Virulencia , Pez Cebra/microbiología
16.
Crit Care Med ; 44(4): e181-9, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26491864

RESUMEN

OBJECTIVES: Extracellular adenosine has tissue-protective potential in several conditions. Adenosine levels are regulated by a close interplay between nucleoside transporters and adenosine kinase. On the basis of the evidence of the role of adenosine kinase in regulating adenosine levels during hypoxia, we evaluated the effect of adenosine kinase on lung injury. Furthermore, we tested the influence of a pharmacologic approach to blocking adenosine kinase on the extent of lung injury. DESIGN: Prospective experimental animal study. SETTING: University-based research laboratory. SUBJECTS: In vitro cell lines, wild-type and adenosine kinase+/- mice. INTERVENTIONS: We tested the expression of adenosine kinase during inflammatory stimulation in vitro and in a model of lipopolysaccharide inhalation in vivo. Studies using the adenosine kinase promoter were performed in vitro. Wild-type and adenosine kinase+/- mice were subjected to lipopolysaccharide inhalation. Pharmacologic inhibition of adenosine kinase was performed in vitro, and its effect on adenosine uptake was evaluated. The pharmacologic inhibition was also performed in vivo, and the effect on lung injury was assessed. MEASUREMENTS AND MAIN RESULTS: We observed the repression of adenosine kinase by proinflammatory cytokines and found a significant influence of nuclear factor kappa-light-chain-enhancer of activated B-cells on regulation of the adenosine kinase promoter. Mice with endogenous adenosine kinase repression (adenosine kinase+/-) showed reduced infiltration of leukocytes into the alveolar space, decreased total protein and myeloperoxidase levels, and lower cytokine levels in the alveolar lavage fluid. The inhibition of adenosine kinase by 5-iodotubercidin increased the extracellular adenosine levels in vitro, diminished the transmigration of neutrophils, and improved the epithelial barrier function. The inhibition of adenosine kinase in vivo showed protective properties, reducing the extent of pulmonary inflammation during lung injury. CONCLUSIONS: Taken together, these data show that adenosine kinase is a valuable target for reducing the inflammatory changes associated with lung injury and should be pursued as a therapeutic option.


Asunto(s)
Lesión Pulmonar Aguda/metabolismo , Adenosina Quinasa/antagonistas & inhibidores , Pulmón/metabolismo , Lesión Pulmonar Aguda/tratamiento farmacológico , Animales , Linfocitos B/metabolismo , Líquido del Lavado Bronquioalveolar/citología , Línea Celular , Citocinas/metabolismo , Lipopolisacáridos/administración & dosificación , Ratones , Neumonía/metabolismo , Estudios Prospectivos , Tubercidina/análogos & derivados , Tubercidina/farmacología
17.
Int J Clin Exp Med ; 8(7): 11260-7, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26379933

RESUMEN

The aim of this study was to investigate if anthropometric parameters are associated with both leptin and soluble leptin receptor (sLEPR) levels in newborns and their mothers. This cross-sectional study was performed in 118 mother-newborn pairs. The venous blood sample of mothers was taken before delivery and immediately after delivery an umbilical cord blood sample was collected. Levels of leptin and sLEPR in maternal and umbilical cord sera were assessed by ELISA. Maternal serum concentration of leptin and sLEPR (6.2 and 25.7 ng/ml, respectively) were higher than in umbilical cord blood (2.4 and 14.2 ng/ml, respectively). However, the newborns and their mothers had higher sLEPR levels than leptin levels. In mothers was observed that leptin levels increase with weight gain in pregnancy and decreased sLEPR levels. Cord leptin levels correlated with neonatal birth weight and length, the body circumferences, placental weight and maternal leptin levels. Cord sLEPR levels correlated with maternal sLEPR and leptin levels. Maternal serum concentration of leptin correlated with pre-pregnancy BMI, weight gain, cord sLEPR and leptin levels. Maternal sLEPR concentration correlated with cord sLEPR levels. The leptin and sLEPR levels in mother-newborn pairs are related with anthropometric parameters and an inverse correlation between leptin levels and sLEPR was observed in pairs.

18.
Food Biophys ; 10(3): 229-234, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26213520

RESUMEN

Results of broadband dielectric spectroscopy (BDS) in Saccharomyces cerevisiae (baker's yeast), in situ as the function of pressure are presented. They show a clear evidence of a threshold to the new pattern of the pressure evolution of the static dielectric permittivity and DC electric conductivity already for Pt ≈ 200MPa at T = 5 oC and Pt ≈ 300MPa at T = 25 oC. BDS monitoring versus pressure tests up to P = 400MPa revealed particularly notable changes of properties after 30 minutes of compressing. Finally, the correlation between the amount of the spectrophotometric maximum absorbance and the DC electric conductivity was found. All these indicate significance of BDS as the tool for testing of pressure properties of cells assemblies, model foods etc., in situ under high pressures.

20.
J Phys Condens Matter ; 25(24): 245105, 2013 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-23719061

RESUMEN

Results of studies of the static and dynamic dielectric properties in rod-like 4-n-octyloxy-4'-cyanobiphenyl (8OCB) with isotropic (I)-nematic (N)-smectic A (SmA)-crystal (Cr) mesomorphism, combined with measurements of the low-frequency nonlinear dielectric effect and heat capacity are presented. The analysis is supported by the derivative-based and distortion-sensitive transformation of experimental data. Evidence for the I-N and N-SmA pretransitional anomalies, indicating the influence of tricritical behavior, is shown. It has also been found that neither the N phase nor the SmA phase are uniform and hallmarks of fluid-fluid crossovers can be detected. The dynamics, tested via the evolution of the primary relaxation time, is clearly non-Arrhenius and described via τ(T) = τ(c)(T-T(C))(-φ). In the immediate vicinity of the I-N transition a novel anomaly has been found: Δτ is proportional to 1/(T - T*), where T* is the temperature of the virtual continuous transition and Δτ is the excess over the 'background behavior'. Experimental results are confronted with the comprehensive Landau-de Gennes theory based modeling.


Asunto(s)
Compuestos de Bifenilo/química , Transición de Fase , Impedancia Eléctrica , Cristales Líquidos/química , Temperatura
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA