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A number of recent reports emphasize the risk of zoonotic diseases and the high degree of prevalence of asymptomatic animals infected with Leptospira interrogans. This report sought to assess the prevalence of antibodies to certain serovars of L. interrogans, and to describe the association between seropositivity and risk factors associated with within-flock transmission in a mountainous region of Mexico. Overall seroprevalence to L. interrogans was 54·5% (95% confidence interval 48·3-60·7); the most frequent serovar was Icterohaemorrhagiae. The accumulation of placentas and fetuses at a site close to lambing paddocks can play a significant role as a risk factor for within-flock transmission of L. interrogans in transhumant farming systems in the municipality of Xalatlaco. The high prevalence of L. interrogans antibodies supports the hypothesis that natural foci of this zoonosis are present in sheep flocks in this area. These findings emphasize the need for planning and implementation of control programmes for ovine leptospirosis in Mexico and elsewhere.

La rentabilidad de los establos lecheros está fuertemente asociada con el desempeño reproductivo. Por lo tanto, la identificación de factores de riesgo que comprometen este desempeño es primordial para implementar estrategias que mejoren la productividad. En este estudio, se probaron los efectos del uso de inseminación artificial (IA), hatos grandes y seroprevalencia alta de enfermedades infecciosas reproductivas sobre el desempeño reproductivo. Se incluyeron al estudio 52 establos (10-100 vacas; 959 lactaciones) registrando eventos reproductivos durante 18 meses (partos 2011-2012). Las seroprevalencias de neosporosis, rinotraqueitis infecciosa bovina (IBR) y diarrea viral bovina (BVD) se registraron en cada establo. Se utilizaron análisis de regresión logística múltiples para determinar el grado de asociación (razón de momios, OR) entre factores potenciales de riesgo y variables reproductivas. Establos ≥33 vacas y seroprevalencia alta de neosporosis fueron factores de riesgo para Asistencia al Parto (OR 1.5 y 2.3, respectivamente). Seroprevalencias altas de IBR y BVD fueron factores de riesgo para Días a Primer Servicio>70 Días en Leche (DPS>70, OR 1.3 y 1.9, respectivamente). La IA fue un factor de riesgo común para DPS>70 y Días Abiertos>110 Días en Leche (OR 2.4 y 1.3, respectivamente). Establos ≥33 vacas fue un factor de riesgo para Vacas No Gestantes al Primer Servicio (OR 1.7). En conclusión, la IA, establos ≥33 vacas y seroprevalencias altas de neosporosis, IBR y BVD son factores asociados al desempeño reproductivo en establos de producción de leche a pequeña escala en varias regiones geográficas de México.

Both Gram-negative and Gram-positive bacteria have recently developed antibiotic resistance to treatments for bovine mastitis, creating a serious concern for public and animal health. The objective of this study was to analyse in vitro microbicidal activity of tea tree oil, thymol and carvacrol (composed of oregano and thyme essential oils) on bacteria isolated from clinical mastitis. Field isolates and ATCC strains of the Staphylococcus spp, Streptococcus spp, Escherichia coli, Klebsiella pneumoniae, and Candida albicans genera were analysed. The agar diffusion technique was used to test bactericidal susceptibility and plate microdilution was utilized to determine the minimum inhibitory, bactericidal, and fractional inhibitory concentrations. Thymol alone and the combinations of thymol-carvacrol and thymol-TTO obtained the highest inhibition diameters for Gram-negative bacteria, while for Gram-positive bacteria and C. albicans , thymol and the combination thymol-carvacrol obtained the highest indices. TTO, thymol, and carvacrol had MIC values of 1.56–25 mg/ml, 0.05–0.4 mg/ml, and 0.02–0.2 mg/ml, respectively. CMB results for the Gram-negative and gram-positive groups were 0.39–0.78 mg/ml, and for C. albicans , 0.78–1.56 mg/ml. Results for the fractional inhibitory concentrations show that the TTO+thymol and thymol+carvacrol combinations had additive activity against groups of Gram-negative bacteria and C. albicans . These natural components, evaluated individually and in combinations, have an effectiveness above 70%.

The production of Nile tilapia (Oreochromis niloticus) has good technological development; however, today, it is still necessary to make it more efficient. One way to increase efficiency is to prevent disease and improve the food conversion factor. Since previous investigations of tilapia microbiota detected a high proportion of organisms belonging to the order Actinomycetes, this study was to isolate, identify, and describe the species of bacteria microbiota belonging to the cultured Nile tilapia. These were done with Nile tilapia grown in a warm sub-humid climate during spring and summer seasons. The biopsy of different organs was performed for bacteriological culture and 16S rRNA sequencing analysis. From the 180 tissue samples, 49 isolates of the order Actinomycetes were obtained, representing ten species from seven genera: Microbacterium, Brevibacterium, Cellulomonas, Corynebacterium, Kocuria, Actinomyces, and Micrococcus. In spring, Microbacterium dominated, accounting for 74% of the total population. In the summer, lower diversity was observed, with 39% represented by Microbacterium. 16S rRNA sequencing analysis enabled the classification of Actinomyces neuii and Microbacterium lacticum as Kocuria varians and Agromyces indicus; the classification of Microbacterium imperiale as Rhodococcus and Micrococcus luteus was confirmed. No sequences of K. varians have been reported in fish. Microbacterium dextranoliticum showed high similarity to environmental samples. Here is the first study that analyzes the bacteria population in tilapia at the genetic level with an ecosystem approach, present in healthy cultured tilapia, indicating their beneficial associations with the host, making them candidates as probiotics, among other possible functions, applicable in tilapia cultivation.

Unidentified abortion, of which leptospirosis, brucellosis and ovine enzootic abortion are important factors, is the main cause of disease spread between animals and humans in all agricultural systems in most developing countries. Although there are well-defined risk factors for these diseases, these characteristics do not represent the prevalence of the disease in different regions. This study predicts the unidentified abortion burden from multi-microorganisms in ewes based on artificial neural networks approach and GLM. Methods: A two-stage cluster survey design was conducted to estimate the seroprevalence of abortifacient microorganisms, and to identify putative factors of infectious abortion. Results: Overall seroprevalence of Brucella was 70.7%, while Leptospira spp. was 55.2%, C. abortus 21.9% and B. ovis 7.4%. Serological detection with the 4 abortion-causing microorganisms was determined only in 0.87% of sheep sampled. The best GLM is integrated by serological detection of serovar Hardjo and Brucella ovis in animals of the slopes with elevation between 2600 to 2800 meters above sea level from municipality of Xalatlaco, as well water supply, sheep pen built with materials of metal grids and untreated wood, with dirt and concrete floors, and bed of straw that remained independently associated with infectious abortion in ewes. Approximately 80% of those respondents did not wear gloves or masks to prevent the transmission of the abortifacient zoonotic microorganisms. Conclusions: Sensitizing stakeholders on good agricultural practices could improve public health surveillance. Further studies on the effect of animal-human transmission in such a setting are worthwhile to further support the One Health initiative.

SUMMARY"Mastitis" refers to inflammation of the mammary gland. Despite the economic losses that it causes in dairy goats, there is scarce information about the epidemiological status of the disease in Mexico. The aim of this study was to develop a multiplex polymerase chain reaction (PCR) test to diagnose Staphylococcus agents involved in caprine mastitis. Milk samples from animals in intensive and semi-intensive production systems were taken from two farms located at Tequisquiapan, Querétaro, Mexico. The samples were obtained from healthy goats. The multiplex PCR was developed to identify coagulase-negative Staphylococcus and S. aureus. To achieve the identification of Staphylococcus spp, primers for the 16s rRNA region were used. Another two pair of primers were used for S. aureus, the first pair corresponded to the clfA gene and the second pair corresponded to the S. aureus coa gene. Multiplex PCR was performed in 30 milk samples and it was possible to detect S. aureus and coagulase-negative Staphylococcus. Further studies are needed to evaluate the sensitivity and specificity of this technique.Key words: mastitis, coagulase-negative Staphylococci, Staphylococcus aureus, multiplex PCR. RESUMENLa mastitis se refiere a la inflamación de la glándula mamaria, a pesar de las pérdidas económicas que produce en cabras lecheras, existe poca información acerca de la situación epidemiológica de la enfermedad en México. El objetivo de este estudio fue desarrollar una reacción en cadena de la polimerasa (PCR) múltiple para el diagnóstico de Staphylococcus spp como agente involucrado en mastitis caprina. Se colectaron muestras de leche de cabras clínicamente sanas en sistemas de producción intensivo y semi-intensivo de dos granjas ubicadas en Tequisquiapan, Querétaro, México. La PCR múltiple se desarrolló para identificar a los Staphylococcus coagulasa-negativos (SCN) y a Staphylococcus aureus. Para lograr la identificación del género Staphylococcus spp se utilizó el par de iniciadores correspondientes a la región 16s RNAr, para el caso de S. aureus se utilizaron 2 pares de iniciadores, el primer par de iniciadores corresponden al gen clfA y el segundo par corresponden al gen coa de S. aureus. Se realizó la PCR múltiple a 30 muestras de leche de cabra en donde se pudo detectar a S. aureus y a SCN, sin embargo, estos estudios son preliminares por lo que se requiere de estudios posteriores para evaluar la sensibilidad y especificidad de esta técnica.

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