Intramammary preparation of enrofloxacin hydrochloride-dihydrate for bovine mastitis (biofilm-forming Staphylococcus aureus).

BACKGROUND: Chronic bovine mastitis is linked to biofilm-producing Staphylococcus aureus (bp-Sa) or Staphylococcus coagulase-negative (bp-Scn). OBJECTIVES: Bp-Sa and bp-Scn were treated with intramammary preparations of either enrofloxacin HCl·2H2O-dimethyl-sulfoxide-chitosan (enro-C/DMSO/chitosan) or enro-C alone. Their potential to inhibit and degrade biofilm formation in vitro was also assessed. METHODS: Milk samples were obtained from the affected quarters in a herd. Phenotypical and genotypical identifications as biofilm-producing Staphylococcus species were carried out. Enro-C/DMSO/chitosan and enro-C alone were assessed to determine their in vitro efficacy in interfering with biofilm formation and their bactericidal effects. A prolonged eight-day treatment with a twice-daily intramammary insertion of 10 mL of enro-C/DMSO/chitosan or enro-C alone was set to evaluate the clinical and bacteriological cures on day 10 in 15 cows per group and the biofilm-inhibiting ability. RESULTS: Fifty-seven percent of the isolates were identified as Staphylococcus spp., of which 50% were bp-Sa, 46% bp-Scn, and 4% Staphylococcus pseudintermedius. One hundred percent of the S. aureus isolated and 77% of Staphylococcus coagulase-negative were biofilm producers. In both groups, the icaA and icaD biofilm-producing genes were identified. The experimental preparation could inhibit biofilm formation, degrade mature biofilms, and have well-defined microbicidal effects on planktonic and biofilm bacteria. The respective clinical and bacteriological cure rates were 100% and 80% for enro-C/DMSO/chitosan and 41.7% and 25% for enro-C alone. CONCLUSIONS: Enro-C/DMSO/chitosan eliminates bp-Sa and bp-Scn from cases of chronic bovine mastitis.

Functional Effects of Prebiotic Fructans in Colon Cancer and Calcium Metabolism in Animal Models.

Inulin-type fructans are polymers of fructose molecules and are known for their capacity to enhance absorption of calcium and magnesium, to modulate gut microbiota and energy metabolism, and to improve glycemia. We evaluated and compared the effects of Chicory inulin "Synergy 1®" and inulin from Mexican agave "Metlin®" in two experimental models of colon cancer and bone calcium metabolism in mice and rats. Inulins inhibited the development of dextran sulfate sodium-induced colitis and colon cancer in mice; these fructans reduced the concentration of tumor necrosis factor alpha and prevented the formation of intestinal polyps, villous atrophy, and lymphoid hyperplasia. On the other hand, inulin treatments significantly increased bone densitometry (femur and vertebra) in ovariectomized rats without altering the concentration of many serum biochemical parameters and urinary parameters. Histopathology results were compared between different experimental groups. There were no apparent histological changes in rats treated with inulins and a mixture of inulins-isoflavones. Our results showed that inulin-type fructans have health-promoting properties related to enhanced calcium absorption, potential anticancer properties, and anti-inflammatory effects. The use of inulin as a prebiotic can improve health and prevent development of chronic diseases such as cancer and osteoporosis.

Efectividad clínica de mallas de alginato de sodio para el control de la diseminación de infección con Escherichia coli y Staphylococcus epidermidis en heridas cavitadas con cierre primario en ratas / Clinical efficacy of sodium alginate meshes for the control of infectious dissemination by Escherichia coli and Staphylococcus epidermidis in cavitated wounds with primary healing

The potential wound healing ability of sodium alginate (SA) meshes was determined in cavitated rat wounds infected either with Escherichia coli or Staphylococcus epidermidis. Wound progress was evaluated macroscopically and histopathologically to assess dissemination of the induced infection through evaluation of granuloma formation and adjacent tissue irritation. Five groups of 24 female Wistar rats weighing 280 ± 34 g were formed as follows: control group with SA mesh without inoculum, control group with Escherichia coli inoculum without SA mesh, control group with Staphylococcus epidermidis inoculum without mesh, group with SA mesh + Escherichia coli inoculum and group with SA mesh + Staphylococcus epidermidis inoculum. Abdominal flank incisions were performed under anaesthesia and groups were formed. Both macroscopic and histopathological follow up were carried out and results indicated that the presence of SA meshes avoids or greatly diminishes bacteria dissemination and adjacent tissue irritation. This reaction occurs even in the presence of Escherichia coli or Staphylococcus epidermidis. In the control groups with SA mesh without inoculum and in the groups with Escherichia coli inoculum without SA mesh, and control group with Staphylococcus epidermis inoculum without mesh and group with SA mesh + Escherichia coli inoculum re-epithelialization and wound healing aspect were better than in groups inoculated with Staphylococcus epidermidis, the general odd ratios showed that the dissemination risk was 58 times greater in treatment with SA mesh and E. coli as infectious agent (IC 95% 6.2-210). These results indicate that SA mesh is capable of providing adequate conditions to allow granulation of cavitated wounds, without irritation to adjacent tissues and avoiding dissemination of the infection by E. coli and Staphylococcus epidermidis in rats. However, presence of granuloma can be a healing or esthetic disadvantage, as observed in control group with SA mesh without inoculum.

Se determinó el efecto potencial de cicatrización de mallas de alginato de sodio (AS) en heridas cavitadas infectadas con Escherichia coli y Staphylococcus epidermidis, y se evaluó histopatológica y macroscópicamente la diseminación del proceso infeccioso, formación de granuloma e irritación de los tejidos adyacentes. Se formaron 5 grupos de 24 ratas Wistar hembras de 280 ± 34 g de la siguiente manera: grupo testigo con malla de AS sin inóculo; testigo con inóculo de Escherichia coli sin malla; otro grupo testigo con inóculo de Staphylococcus epidermidis, sin malla; grupo con malla de AS + inóculo de Escherichia coli; grupo con malla de AS + inóculo de Staphylococcus epidermidis. Bajo anestesia se realizaron las incisiones en los flancos absominales y se formaron los grupos. Se realizó un seguimiento macroscópico e histopatológico de la zona afectada y se encontró que la presencia de mallas de AS evita o disminuye drásticamente, tanto la diseminación de la infección a tejidos adyacentes como su irritación. Ello ocurre aun en presencia de Escherichia coli o de Staphylococcus epidermidis. En los grupos testigo con malla de AS sin inóculo, testigo con inóculo de Escherichia coli sin malla, otro grupo testigo con inóculo de Staphylococcus epidermidis sin malla y el grupo con malla de AS + inóculo de Escherichia coli, la reepitelización y la reducción en la herida fueron superiores a los grupos que fueron inoculados con Staphylococcus epidermidis. Los odd ratios generales mostraron que el riesgo de diseminación fue 58 veces menor con el uso de malla de AS y E. coli como organismo infectante (IC 95% 6.2-210). Los resultados encontrados indican que la malla de AS es capaz de proporcionar condiciones adecuadas para la formación de tejido de granulación, sin irritación en los tejidos adyacentes y evitando la diseminación de la infección en heridas cavitadas y contaminadas por E. coli y por Staphylococcus epidermidis en ratas. Sin embargo, la presencia de granuloma puede significar una desventaja cicatrizal o estética, como se observó en el grupo testigo con malla de AS sin inóculo.

Induction of a protective immune response to rabies virus in sheep after oral immunization with transgenic maize, expressing the rabies virus glycoprotein.

The introduction of exogenous genes into plants permits the development of a new generation of biological products, i.e., edible vaccines. Cereals, especially maize, have been the systems of choice for the expression of antigenic proteins because the proteins can be expressed at high levels in the kernel and stored for prolonged periods without excessive deterioration. The utilization of plant-derived antigens for oral delivery provides an alternative strategy for the control of pathogens in animals compared to the current vaccine administration methods, such as injection. However, there is some doubt about the efficacy of these types of vaccines in polygastric animals due to the features of their digestive system. Here, we report the efficacy of an edible vaccine against rabies evaluated in sheep. Kernels containing different doses of G protein (0.5, 1, 1.5 and 2mg) were given in a single dose by the oral route. Cumulative survival was better in groups that received 2mg of G protein and for the positive control (inactivated rabies vaccine); this observation was supported by the presence of neutralizing antibodies. Animals in the control group died after challenge. The degree of protection achieved for 2mg of G protein was comparable to that conferred by a commercial vaccine. In conclusion, this is the first study in which an orally administered edible vaccine showed efficacy in a polygastric model.

Actitudes y percepciones de consumidores en la Ciudad de México, hacia atributos de la producción sustentable de alimentos de origen animal / Consumer attitudes and perceptions towards sustainable animal production attributes in Mexico City

Animal production systems in pursuit of sustainability production, have to integrate several elements such as: environmental protection, food safety, animal welfare, and benefits to local producers. The objectives of the study were: 1) identify the attitudes of consumers in three districts of Mexico City towards sustainable attributes; 2) identify their perceptions regarding the production of animal food products; 3) determine if there is an effect of the social-demographic variables. In this sense, one thousand two hundred consumers were surveyed in markets of three districts of Mexico City with different social-economic levels. Results show that attitudes and perceptions of consumers differ mainly according to the district where they reside. In relation to the sustainable attributes, consumers considered food safety as the most important attribute of an animal product, followed by environmental protection. Regarding animal food production in Mexico, consumers perceived in first place that this benefits local producers, that they are safe products, that it improves animal welfare, and, finally, that it conserves the environment. These results revealed that consumers in Mexico City show positive attitudes towards sustainable animal food production attributes, which could represent new opportunities for the food industry in Mexico.

Los sistemas de producción de alimentos en búsqueda de una producción sustentable, integran diversos elementos como: protección al ambiente, inocuidad de los alimentos, bienestar animal y beneficios para los productores locales. Los objetivos del estudio fueron: 1) identificar actitudes de los consumidores en tres delegaciones de la Ciudad de México hacia atributos de sustentabilidad; 2) identificar sus percepciones con respecto a la producción de alimentos de origen animal en México; 3) determinar si existe un efecto de las variables sociodemográficas. Para este fin se encuestaron a 1200 consumidores de diferentes niveles socioeconómicos, en mercados de tres delegaciones de la Ciudad de México. Los resultados muestran que las actitudes y percepciones de los consumidores difieren principalmente según la delegación donde residen. Respecto a los atributos de sustentabilidad, los consumidores consideraron la inocuidad de los alimentos como el atributo más importante de un producto de origen animal, seguido por la protección al ambiente. En relación con la producción de alimentos de origen animal en México, los consumidores percibieron en primer lugar, que ésta beneficia a los productores locales, que son alimentos seguros, que se mejora el bienestar animal, y finalmente, que se conserva el ambiente. Lo anterior muestra que los consumidores en la Ciudad de México tienen actitudes positivas hacia los atributos de la producción sustentable de alimentos de origen animal, lo cual representa nuevas oportunidades para la industria alimenticia en México.

Inheritance of resistance to flumethrin in the Mexican Aldama strain of the cattle tick Boophilus microplus (Acari: Ixodidae).

The objective of this study was to evaluate the inheritance mode of resistance to flumethrin in the Mexican Aldama Boophilus microplus strain. Two Mexican strains were used, the Chiapas susceptible (SS), and the Aldama flumethrin-resistant from Tamaulipas. Six steers weighing ca. 250 kg were randomly assigned for each of six crosses: the susceptible (SS), resistant (RR), and the F1 (RS, SR) reciprocal crosses and F2 (RS x RS and SR x SR). The reciprocal crosses were made to evaluate maternal and sex linkage effects. Bioassays tested resistant and susceptible larvae along with their hybrid F1 and F2 progeny against a series of concentrations of flumethrin (0, 0.0075, 0.00150, 0.00300, 0.00600 and 0.01200 microg/g). To test the single-gene hypothesis of resistance, a nonparametric line-cross test proposed by Collins was used. The bioassay data were subjected to probit analysis and the resistance factor and effective dominance obtained. Results of this study indicated that inheritance for flumethrin resistance in the Aldama strain was autosomal and controlled for more than one gene. The F1 and F2 larvae had similar lower resistant factor (RF 2.8-4.5) while the resistant Aldama strain was 21-fold higher (RF 81.8) than the mean of the F1 and F2. The extent of flumethrin resistance in the Aldama B. microplus strain depended upon the concentration of the pesticide used. Resistance was almost dominant at the lowest dose while almost completely recessive at the highest dose. Maternal effects were shown for egg-mass. These results shown here indicate more than one gene basis of flumethrin resistance in B. microplus ticks are present. Therefore it is necessary to locate and understand the major loci for elucidate the mechanism of resistance and improve the ability to track and delay the evolution of resistance.

Serotipos de Pasteurella multocida y Pasteurella Heamolytica aislados a partir de pulmones con lesiones inflamatorias de ovinos y caprinos / Serotypes of Pasteurella multocida and Pasteurella heamolytica isolated from ovine and caprine lungs

El presente trabajo se ralizó con el objetivo de aislar y determinar los serotipos capsulares y somáticos de Pasteurella multocida y los serotipos de Pasteurella haemolytica, a partir de pulmones con lesiones inflamatorias de ovinos y caprinos. Con tal propósito de tomaron muestras de 232 lesiones neumónicas , obteniéndose un total de 117 aislamientos positivos a Pasteurellas, de las cuales 42 cepas se identificaron como P. heamolytica y 75 como P. multocida. El 100 por ciento de los aislamientos de P. haemolytica perteneció al biotipo A. Los serotipos determinados por Hemoaglutinación Indirecta (HAI) según la especie animal fueron: En ovinos con 28 cepas el 39 por ciento para el A 8, el 32 por ciento el A , 11 por ciento A 1, 7 por ciento A 6, 4 por ciento A 5 y 7 por ciento no tipificables; en caprinos con 2 cepas, A 5 y A 8 respectivamente. En los aislamientos de P. multocida, según las técnicas de Acriflavina e Hialuronidasa, 60 por ciento perteneció al tipo A y 27 por ciento al D. Los serotipos somáticos por Inmunodifusión en gel representaron en ovinos el 72 por ciento para el serotipo 3, 9 por ciento para el 15, 4 por ciento para el 7, 2 por ciento para el 4, 10, 12 y 14 y 7 por ciento de no tificables: en caprinos con 3 cepas una perteneció al serotipo 3, otra al 15 y la restante no tipificable. Se analizan la distribución de los serotipos de Pasteurella sp encontrados en el presente estudio con otros informes al respecto.