Leucaena leucocephala represents a local protein source in tropical ruminant diets. However, its full exploitation is impaired by mimosine, unless it is degraded by the rumen microbial community. Recently, the ruminal bacterial communities of newborns were persistently modified through prenatal or postnatal dietary interventions. Such early-life interventions might enhance adaptation of ruminants to Leucaena leucocephala, which was investigated using a 2 × 2 factorial design trial that tested both supplementation of L. leucocephala in the late pregnancy diet of goat does, and supplementation of live yeast to their newborns. The composition of ruminal bacteria, immune status, as well as organic matter digestibility (OMD) and performance of kids were studied during and after the intervention. Ten pregnant goats were divided into two groups: the D+ and D– groups, which either received or did not receive 30 g of L. leucocephala forage meal during the last 7 ± 0.5 weeks of gestation. Twins from each goat were divided into the K+ and K– group (supplemented with or without 0.2 g/d of live yeast from day 3 until weaning at 8 weeks). Rumen samples were collected from 4-, 8-, 14-, and 20-weeks old kids to assess the bacterial community, while immune parameters (white blood cells, immunoglobulin M and G, and chitotriosidase activity) were measured in blood and saliva sampled at 4-, 8-, and 20-weeks. We found a stimulatory effect of the prenatal exposure on the post-weaning dry matter intake of the L. leucocephala supplemented diet, resulting in a higher daily gain and final body weight at 20 weeks in the D+ vs. D– group (406 vs. 370 g DM/d, 85.4 vs. 78.6 g/d, and 15.2 vs. 13.8 kg, respectively). Moreover, Ruminococcus represented a greater proportion of the rumen bacterial community of the D+ vs. D– kids (5.1 vs. 1.6%). Differences in the immune status were relatively small and not thought to be a driving factor of differences in animal performance. Furthermore, postnatal supplementation of live yeast favored maturation of the rumen bacterial community (i.e., greater abundance of Bacteroidetes, in particular Prevotella, and reduced abundance of Firmicutes) and protozoa colonization. Concomitantly, OMD was enhanced post-weaning, suggesting effects of the early-life intervention persisted and could have affected animal performance.

Dromedary camels are an important source of food and income in many countries. However, it has been largely overlooked that they can also transmit antibiotic-resistant bacteria. The aim of this study was to identify the Staphylococcaceae bacteria composition of the nasal flora in dromedary camels and evaluate the presence of methicillin-resistant Mammaliicoccus (MRM) and methicillin-resistant Staphylococcus (MRS) in dromedary camels in Algeria. Nasal swabs were collected from 46 camels from seven farms located in two different regions of Algeria (M’sila and Ouargla). We used non-selective media to determine the nasal flora, and antibiotic-supplemented media to isolate MRS and MRM. The staphylococcal isolates were identified using an Autoflex Biotyper Mass Spectrometer (MALDI-TOF MS). The mecA and mecC genes were detected by PCR. Methicillin-resistant strains were further analysed by long-read whole genome sequencing (WGS). Thirteen known Staphylococcus and Mammaliicoccus species were identified in the nasal flora, of which half (49.2%) were coagulase-positive staphylococci. The results showed that four out of seven farms were positive for MRS and/or MRM, with a total of 16 isolates from 13 dromedary camels. The predominant species were M. lentus, S. epidermidis, and S. aureus. Three methicillin-resistant S. aureus (MRSA) were found to be ST6 and spa type t304. Among methicillin-resistant S. epidermidis (MRSE), ST61 was the predominant ST identified. Phylogenetic analysis showed clonal relatedness among M. lentus strains, while S. epidermidis strains were not closely related. Resistance genes were detected, including mecA, mecC, ermB, tet(K), and blaZ. An SCCmec type VIII element was found in a methicillin-resistant S. hominis (MRSH) belonging to the ST1 strain. An SCCmec-mecC hybrid element was detected in M. lentus, similar to what was previously detected in M. sciuri. This study highlights that dromedary camels may be a reservoir for MRS and MRM, and that they contain a specific set of SCCmec elements. This emphasizes the need for further research in this ecological niche from a One Health perspective.

Introducción. Los mosquitos (Diptera: Culicidae) son uno de los organismos más versátiles del mundo, pues pueden reproducirse en cualquier depósito de agua, como charcos o tanques. Sin embargo, su reproducción está influenciada por variables atmosféricas que permiten predecir su densidad poblacional.Objetivo. Evaluar el impacto de la presión atmosférica en la densidad poblacional de mosquitos en la provincia de Villa Clara, Cuba, mediante el uso de modelos matemáticos basados en la metodología de regresión objetiva regresiva (ROR).Materiales y métodos. El desarrollo del modelo matemático de pronóstico de focos de reproducción se basó en el número de focos reportados en la provincia de Santa Clara entre 2000 y 2017, y en el modelo ROR. Además, se realizó un análisis de regresión mediante el programa IBM SPSS® versión 19.0, lo que permitió obtener modelos de regresión que explicaron el 100% de la varianza, con su error típico.Resultados. Respecto a la cantidad de focos, se observó una tendencia al aumento en el municipio de Cifuentes, mientras que en Ranchuelo y Caibarién la tendencia fue a la reducción. Los municipios de Santa Clara y Encrucijada tuvieron la desviación estándar más alta y más baja, respectivamente (134.32 vs. 5.968), lo que evidencia una gran variabilidad entre los datos de cada municipio.Conclusiones. Existe una estrecha relación entre la presión atmosférica y la densidad poblacional de mosquitos, ya que a medida que aumenta la presión atmosférica, aumentan las densidades larvales, tanto total como específicas.

La emergencia mundial de Salmonella multirresistente a antimicrobianos es de creciente preocupación, estudios recientes resaltan la relación entre el consumo de antibióticos por los animales y los diversos mecanismos de resistencia desarrollados por los microorganismos. En el presente estudio se investigó la circulación de Salmonella spp. asociada a procesos infecciosos en animales domésticos, así como los patrones de susceptibilidad antimicrobiana. El muestreo y el aislamiento de Salmonella spp. se llevaron a cabo en el Departamento de Bacteriología General del Laboratorio Provincial de Diagnóstico Veterinario de la provincia Villa Clara, Cuba, durante 2016. El método Kirby-Bauer se empleó para determinar la susceptibilidad antimicrobiana. Para el análisis de los resultados se empleó el paquete estadístico Statgraphics Centurion versión XV-II / 2006 aplicando procedimientos descriptivos, y pruebas de comparación múltiple de proporciones, para la evaluación de los porcentajes de resistencia de Salmonella por especie animal y por serogrupo. Se identificaron 46 aislados de Salmonella spp. pertenecientes a los serogrupos B, C1, C2 y D en el 15% de las muestras, todas provenientes de gallinas, bovinos, ovinos y cerdos. En general, los patrones de resistencia antimicrobiana fueron expresados para la ampicilina (en el 46% de los aislados), compuestos de sulfonamida (28%), ácido nalidíxico (26%) y tetraciclina (22%); no se detectó resistencia a ciprofloxacina, gentamicina y cefotaxima. Los aislados de Salmonella spp. más resistentes fueron de los serogrupos B y D, así como los provenientes de ovinos y cerdos.

In this study, the in vitro apparent rumen degradability of organic matter (ARDOM) and plant secondary metabolites (ARDPSM) of three tropical legumes (Mucuna pruriens, Canavalia ensiformis and Leucaena leucocephala) were assessed. For this, single end-point incubations (24 h) as well as kinetic assessments (0, 2, 4, 6, 8, 10, 12 and 24 h) were set up with different inocula sources, i.e. ruminal inocula from Belgian and Cuban sheep. L-mimosine, L-canavanine, Concanavaline A (Con A) and trypsin inhibitor (TI) were the plant secondary metabolites (PSM) targeted in this study. Bean and forage/bean meals of M. pruriens and C. ensiformis as well as their PSM were extensively degraded during 24 h incubation (0.70 and 0.78 g ARDOM/g of organic matter (OM), respectively and > 0.80 g/g for L-canavanine, > 0.76 TIU/TIU for TI and > 0.95 g/g for Con A, for both legumes). Forage meal of L. leucocephala was considerably less degraded, with apparent ruminal degradabilities of 0.20 and 0.35 g ARDOM/g OM after 24 h incubation with Belgian or Cuban sheep inoculum, respectively. This could -at least partially -be related to L-mimosine, present in L. leucocephala, which was hardly degraded in the Belgian incubation, while a more extensive ruminal breakdown was observed under the Cuban conditions (0.05 to 0.78 g ARDPSM/g PSM, respectively). The negative effect of L-mimosine on OM degradability was supported by in vitro incubations with straw and inoculum from Belgian sheep, as ruminal degradation of straw was 31% lower when L-mimosine was supplemented.