DETECCIÓN SEROLÓGICA Y MOLECULAR DE LENTIVIRUS DE PEQUEÑOS RUMIANTES QUE CIRCULAN DE FORMA NATURAL EN OVINOS DE DOS ESTADOS DEL ALTIPLANO MEXICANO.

Los lentivirus de pequeños rumiantes (LvPR) presentan una amplia distribución mundial, provocan enfermedades multisistémicas, crónicas degenerativas e incurables en ovinos y caprinos. En 2010, se realiza la primera secuenciación del genoma completo de LvPR en México y se clasificó dentro del subgrupo B1. Para el 2016, las infecciones por lentivirus en los ovinos fueron incluidas en el Diario Oficial de la Federación. Por lo que los reportes sobre la infección natural por LvPR en ovinos son pocos, el objetivo de este trabajo fue detectar serológica y molecularmente la infección por lentivirus en ovinos y caprinos de dos estados de la región del altiplano mexicano y la evaluación de la capacidad antigénica de una proteína recombinante CAp25. Se encontró la presencia de anticuerpos de ovinos y caprinos contra la proteína SU, gp135, y solo de caprinos contra la CA, p25, el análisis de los epitopes antigénicos se encontraron diferencias antigénicas en las regiones inmunodominantes de la proteína CA, p25 en aislamientos ovinos previamente reportados por otros autores. Aunado a esto, en el presente trabajo, se logró determinar la presencia de provirus tanto en ovinos como en caprinos. Con lo que se podemos concluir que la combinación entre métodos moleculares y serológicos, representa una estrategia importante para la identificación de infecciones por LvPR en los ovinos y caprinos.El estudio fue financiado por el proyecto de investigación: “Desarrollo de una prueba de ELISA indirecta basada en la proteína recombinante de la cápside (CAp25) expresada en E. coli, para el diagnóstico en lentivirus en caprinos”. Recursos Fiscales INIFAP No. SIGI. 1115534018

First identification and characterization of Streptococcus iniae obtained from tilapia (Oreochromis aureus) farmed in Mexico

Estudio de cuadros septicémicos por Streptococcus iniae en tilapias de cultivo de México.This is the first study to isolate, identify and characterize Streptococcus iniae as the causative disease agent in two tilapia (Oreochromis aureus) populations. The populations were geographically isolated, of distinct origins, and did not share water sources. Affected fish showed various external (e.g., exophthalmia and cachexia, among others) and internal (e.g., granulomatous septicaemia and interstitial nephritis, among others) signs. All internal organ samples produced pure cultures, two of which (one from each farm, termed S-1 and S-2) were subjected to biochemical, PCR and 16S rRNA sequencing (99.5% similarity) analyses, confirming S. iniae identification. The two isolates presented genetic homogeneity regardless of technique (i.e., RAPD, REP-PCR and ERIC-PCR analyses). Pathogenic potentials were assessed through intraperitoneal injection challenges in rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio). Rainbow trout mortalities were respectively 40% and 70% at 104 and 106 CFU per fish with the S-1 isolate, while 100% mortality rates were recorded in zebrafish at 102 and 104 CFU per fish with the S-2 isolate. The obtained data clearly indicate a relationship between intensified aquaculture activities in Mexico and new disease appearances. Future studies should establish clinical significances for the tilapia industry.Universidad Autónoma del Estado de México, Grant/Award Number: 3675/2014/CID and 4489/2018/CI. Comisión Nacional de Investigación Científica y Tecnológica, Grant/Award Number: FONDAP 15110027, FONDECYT 115069

Phenotypic and genotypic profile of clinical and animal multidrug-resistant Salmonella enterica isolates from Mexico

Descripción de Salmonella enterica multirresistenteAims: The objective of this study was to obtain a phenotypic and genotypic profile of Salmonella enterica including multidrug-resistant (MDR) isolates from food-producing animals and clinical isolates, as well as their genetic relatedness in two different States of Mexico (Jalisco and State of Mexico). Methods and Results: A total of 243 isolates were evaluated in terms of antimicrobial resistance (AMR) and related genes through a disk diffusion method and PCR respectively; we found 16 MDR isolates, all of them harbouring the blaCMY gene but not qnr genes, these isolates represent less than 10% of the collection. The pulsed-field gel electrophoresis revealed a higher genotypic similitude within isolates of State of Mexico than Jalisco. Conclusions: A low percentage of Salmonella isolates were resistant to relevant antibiotics in human health, nevertheless, the AMR and involved genes were similar despite the different serovars and origin of the isolates. Significance and Impact of the Study: This investigation rovided an insight of the current status of AMR of Salmonella isolates in two States of Mexico and pinpoint the genes involved in AMR and their epidemiological relationship, the information could help to determine an adequate therapy in human and eterinary medicine

Serotypes, virulence genes profiles and antimicrobial resistance patterns of Escherichia coli recovered from feces of healthy lambs in Mexico

Articulo que habla de la resistencia a los antibióticos en corderosHealthy lambs are one of the major reservoirs of Shiga toxin-producing Escherichia coli (STEC) and it is known as the cause of foodborne diseases (FBD). The work objective is to characterize (STEC) isolates obtained from rectal swabs of healthy lambs herds, a total of 183 samples were obtained from sheep production units of the State of Mexico. E. coli isolates were confirmed through the amplification of the uid A gene. antimicrobial sensitivity pattern was determined through Kirby-Bauer (CLSI, 2012) test and the presence stx1, stx2 and eae genes from isolates by multiplex PCR. Serotyping was performed using specific anti-O and anti-H sera (SERUNAM, Mexico) for 185 Somatic and 56 flagellar antigens. 126 isolates biochemically and molecularly identified as E. coli were obtained, of which 80 did not express any virulence factor and 46 expressed at least some (STEC) virulence factor. The highest percentage of E. coli resistance was for tetracycline 48.7% (39/80), followed by nalidixic acid 13.7% (11/80), gentamicin 6.2% (5/80) and Ciprofloxacin 3.7% (3/80). Resistance to amikacin, cefotaxime and ceftazidime were not detected. A frequency of 46 STEC isolates (36.2%) were obtained, of which 28/46 (22.0%) expressed stx1, stx2 3/46 (6.5%), stx1, stx2 13/46 (10.2%) and eae 2/46 (1.6%). Thirty different serotypes were obtained. The three serotypes with the highest number of isolates (four each) were: O76:H19, O118:H27 and O146:H21 which have been identified as a cause of diarrhea in human population. An isolate of serogroup O104 was obtained, with a significant importance for European public health. In virtue of the discovered serotypes and the virulence factors distribution, we can affirm that the obtained isolates from lambs in the State of Mexico are classifiable as atypical STEC of low virulence

Effects of dietary chromium-yeast level on growth performance, blood metabolites, meat traits and muscle fatty acids profile, and microminerals content in liver and bone of lambs

To assess the effect of dietary supplement levels of chromium-yeast (Cr-yeast) on growth performance, blood glucose and triglycerides, fatty acid (FA) profile in intramuscular fat, carcase and meat traits, iron, copper, chromium and zinc concentrations in liver and bone, 24 Rambouillet male lambs (29.2 ± 0.17 kg body weight) were randomly assigned to four diets with 0, 0.2, 0.4 and 0.6mg Cr/kg DM. The growth performance trial lasted 49 d. Supplemental Cryeast did not affect growth performance and carcase characteristics (p>.05), but reduced (p<.05) perirenal and intramuscular fat, as well as 3 h post-feeding blood glucose and triglycerides concentration. In liver, Fe and Cu concentration decreased (p<.05), while Cr concentrations in liver increased with increasing Cr-yeast dietary levels. In bone, Fe decreased (p<.05) as Cryeast dietary levels increasing, and Cr-yeast supplementation increased Cr concentrations (p<.05). As Cr-yeast dietary level increased, palmitic (C16:0) and stearic (C18:0) SFA decreased linearly (p<.05), while palmitoleic (C16:1n-7), vaccenic (C18:1n-7), linoleic (C18:2n-6) and arachidic (C20:4) unsaturated fatty acids (UFA) increased linearly (p<.01). In conclusion, Cr-yeast did not affect growth performance and carcase quality, but decreased the perirenal and intramuscular fat, blood glucose and triglyceride content, and Fe and Cu concentrations in liver as increased Cr-yeast levels in the diet. Because supplemental Cr-yeast improved index of atherogenicity and unsaturated to saturated FA ratio in muscle of lambs, it could be of human nutritional interest

Aislamiento e identificación fenotípica y genotípica de Moraxella ovis de casos clínicos de queratoconjuntivitis ovina en el Estado de México

La queratoconjuntivitis contagiosa ovina (QCO) es una enfermedad infectocontagiosa que produce ceguera temporal o permanente en ovinos y caprinos, se encuentra asociada a un conjunto de agentes infecciosos como Moraxella ovis, Mycoplasma conjunctivae y Chlamydia psittaci, el diagnóstico se realiza mediante un examen clínico y pruebas de laboratorio. De un total de 861 animales examinados, 209 presentaron algún tipo de lesión ocular resultando en una prevalencia del 24.27% de animales con lesiones compatibles con QCO. De las 209 muestras remitidas al laboratorio se lograron identificar 58 como Moraxella ovis mediante bacteriología y por la amplificación de los genes 16S rRNA y RxtA por PCR. En virtud de los resultados podemos concluir que Moraxella ovis esta involucrada en los casos de QCO en establecimientos productores de ovinos en el Estado de México

Mecanismos de defensa e inmunidad de la glándula mamaria en la vaca lechera

La respuesta inmune contra los agentes infecciosos involucra una compleja interacción entre diferentes tipos de células y sus productos, que culmina con la eliminación del agente infeccioso o la muerte del animal. La glándula mamaria está protegida por una variedad de mecanismos de defensa, que forman parte de la inmunidad innata y de la inmunidad específica. Durante las primeras etapas de la infección se activan los mecanismos inespecíficos de defensa en caso de ser sobrepasados los mecanismos de inmunidad específica se activan con el fin de controlar al patógeno y crear memoria inmunológica la que resultará en un ataque rápido en una segunda exposición al patógeno. Por otra parte la inmunidad se produce por la interacción de los agentes infecciosos y los mecanismos inmunes, durante la infección o mediante la administración de las vacunas se desarrolla la inmunidad local y sistémica. A su vez las células somáticas de la leche que representan una proporción normal de células epiteliales y leucocitos, son consideradas un indicador de la respuesta celular inducida por la inflamación de la glándula mamaria al producirse la agresión. El conocimiento de los mecanismos inmunes y la resistencia a la enfermedad, son fundamentales para el desarrollo de estrategias de prevención y control de la mastitis, para mejorar la salud de la glándula mamaria en el hato lechero. Por último se discute la implicación del estrés calórico en la ocurrencia de mastitis.UAE

The Effect of Feeding Horses a High Fiber Diet With or Without Exogenous Fibrolytic Enzymes Supplementation on Nutrient Digestion, Blood Chemistry, Fecal Coliform Count, and In Vitro Fecal Fermentation

Forage feeds have low protein content and low nutrients digestibility [3,4]. There is a need for developing new feeding strategies to meet horse nutrient requirements while maintaining gut health and integrity. In ruminant diets, exogenous fibrolytic enzymes have been shown to improve the digestion of plant fiber fractions by improving ruminal fermentation working synergetically with endogenous rumen microbial enzymes [4]. The large intestine of the horse is a fermentation system similar to the rumen [5]. Microorganisms living in the rumen of ruminant animals and in the cecum of horses give them the ability to breakdown fibers by microbial fermentation to meet energy demands [6].Sixteen Quarter Horse mares (450 to 500-kg body weight) were used in a complete randomized design to determine the effects of feeding a high fiber diet with or without exogenous fibrolytic enzymes on nutrient digestion, blood chemistry, fecal coliform count, and in vitro fecal fermentation. The treatments comprised feeding the horses (1) a basal diet without enzyme addition (control); (2) control diet plus cellulase at 10 mL/mare/ d (CELL); (3) control diet plus xylanase at 10 mL/mare/d (XYL); or (4) control diet plus a mixture of 5 mL cellulase and 5 mL xylanase/mare/d (CX). The basal concentrate diet consisted of a mixture of 50% commercial concentrate and 50% wheat bran fed at 4 kg/ horse, offered twice daily at 04:00 and 16:00 hours, and oat straw offered ad libitum at 05:00 and 17:00 hours. The enzyme allocation for each day was mixed with 1 kg of concentrate diet at 04:00 hours, and the experiment lasted for 15 days comprising 10 days of adaptation and 5 days for sample collection. The in vitro cecal fermentation with addition of 2 mL/g dry matter (DM) of each enzyme (CELL, XYL, and CX) to a basal diet of oat straw and concentrates mixture (1:1 DM) as a substrate was carried out. The mares fed enzyme-supplemented diets had greater (P .05) with enzymes addition on carbon dioxide production at different hours of incubation compared with control treatment

Determinación de linfocitos T CD4, CD8 y Tγδ en la infección experimental con Brucella ovis

El objetivo de este estudio fue determinar la distribución sanguínea de linfocitos T CD4, CD8, LT γδ (WC1) en carneros infectados experimentalmente con Brucella ovis. Se utilizaron 18 carneros de 1 a 4 años y libres de B. ovis distribuidos en tres grupos: Control (n=6); Inoculado en las mucosas ocular y prepucial (n=6); Inoculados vía endovenosa (n=6). Se realizó el seguimiento serológico desde el día de la inoculación hasta el 189 dPI (día pos-inoculación). Se inmunotipificaron las poblaciones de linfocitos CD4 y CD8 a los 120, 150 y 189 y de WC1 (linfocitos Tγδ) a los 120 dPI por citometría de flujo. Los carneros, a partir del tercer dPI comenzaron a seroconvertir; a los 21 y 28 dPI todos los animales de los grupos inoculados por vía endovenosa y mucosa, respectivamente, resultaron positivos; asimismo, el 50% de los animales de los grupos desafiados se presentaron como positivos o sospechosos a la prueba de ELISA a los 189 dPI. Se encontraron diferencias en las Medias de Intensidad de Fluorescencia (MIF) de los linfocitos CD8 entre el grupo control (1027.4) y el grupo inoculado por vía endovenosa (499.6) a los 120 dPI (p<0.05) y en las MIF de los linfocitos CD4 entre grupos a los 189 dPI (p<0.05). Las poblaciones linfocitarias T γδ (WC1) presentaron diferencias en MIF entre el grupo control y los grupos inoculados a los 120 dPI (p<0.05). Los resultados indican que B. ovis puede modular la respuesta inmune del hospedero, que los linfocitos CD4 y CD8 son importantes para la defensa del hospedero ante esta infección, y que las poblaciones de CD4 como de CD8 pueden fluctuar durante el periodo de infección por B. ovis. Así mismo, la participación de los linfocitos T γδ podría ser un factor importante en el control de la infección causada por B. ovis

Mineral status and interrelationship in soil, forage, and blood serum of horses in the rainy and dry seasons

The feeding and nutrition of livestock becomes less of an empirical endeavor when the information necessary to scientifically balance diets is available [1]. Equine performance is influenced by genetic, nutritional, health, and management factors. Thus, optimal nutrition is essential for a foal to achieve maximal performance. Likewise, nutrition is fundamental for husbandry purposes as several reproductive problems due to nutritional deficiencies have been identified [2].The objective was to evaluate the content of P, Ca, Mg, K, Na, Cu, Fe, Zn, Se, and Mn in soil, forage, and serum of horses in several production units (PU) during rainy and dry seasons and predict their concentration in serum from their content in soil and forage. Soil and pastures were sampled in the dry (November–December) and in rainy seasons (June–July), and blood samples were collected from the jugular vein of 76 horses in both seasons at four PU. The experimental design was a completely random design within a 4 2 (PU season) factorial arrangement of treatments. Concentration of minerals in soil differed (P < .05) among PU, and contents of P, Ca, Mg, and K were low; Zn and Fe were high; and Cu and Mn were adequate. Mineral concentrations in forage differed among PU and season, and among PU within season (interaction P <.05). Contents of Ca, Mg, Na, Zn, and Cu were low; Fe was high; and P, K, Se, and Mn adequate. The mineral concentration in equine blood serum differed (P <.05) among PU and season. Overall, there were deficiencies of P, Ca, Mg, Na, Cu, and Se, but adequate amounts of K, Zn, and Fe. There are imbalances of minerals in soil and forages which effected their concentration inequine blood