Main pathologies associated with "Staphylococcus aureus" infections in rabbits: a review

[EN] Staphylococcus aureus is a versatile opportunistic pathogen that causes a wide spectrum of pathologies. In rabbits, this bacterium infects dermal lesions causing suppurative dermatitis, and invades subcutaneous tissues, causing different well-known disease conditions such as mastitis, abscesses (subcutaneously or affecting internal organs) and pododermatitis. However, the lesions associated with S. aureus have rarely been described in detail in the literature. The aim of this paper is to update the knowledge on rabbit staphylococcosis by focusing mainly on the different pathologies that this organism produces in commercial rabbits.The studies on staphylococcal infections in Dr. Corpa’s group are funded by the CEU-Cardenal Herrera University (PRUCH02/25, 04/11, 05/09, B06/18, 01/08, 23/08 and the Copernicus-Santander research programme of the CEUUCH and Banco de Santander), the Valencian Regional Government - Generalitat Valenciana - (GV05/202, ARVIV/2007/007, ACOMP/2009/207) and the Spanish Ministry of Science and Innovation (AGL2008-00273/GAN). The studies in the group of K. Hermans and F. Haesebrouck have been, and continue to be funded by the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT Vlaanderen) and the Research Fund of Ghent UniversityUniversidad Cardenal Herrera CEU (UCH-CEU)Generalitat Valenciana (GV)Ministerio de Ciencia e Innovación (MICINN)Corpa, J.; Hermans, K.; Haesebrouck, F. (2009). Main pathologies associated with "Staphylococcus aureus" infections in rabbits: a review. World Rabbit Science. 17(3):115-125. https://doi.org/10.4995/wrs.2009.65111512517

Reproductive performance of rabbit females from three paternal lines with a different potential for growth rate and resilience

[EN] A total of 197 nulliparous rabbits (from three paternal lines) were used to test potential strategies to overcome the consequences on reproduction associated with the selection for high growth rate. The R line was selected for growth rate during the growing period for 37 generations, the RF line was founded through a high selection intensity of elite animals of the R line, and the RFLP line, which was obtained by backcrossing RF animals with the LP line (a long-lived productive maternal line, characterised by high resilience). Body weight, perirenal fat thickness, fertility, daily feed intake, milk yield and blood metabolites of females were controlled from 1st artificial insemination to 3rd parturition. Litter size, litter weight, individual weight and feed ingestion of kits were controlled from birth to weaning. Our results show that RF females were significantly lighter than R and RFLP females throughout the trial (-5.0%; P<0.05). Furthermore, RF animals had a higher fertility rate than RFLP females, at first cycle (+10.5 percentage points; P<0.05). However, RFLP had a higher fertility rate than RF females at second cycle (+21.5 percentage points; P<0.01). On average, RFLP females had higher perirenal fat thickness than R females at parturition (+3.0%; P<0.05) and higher daily feed intake than of R and RF females during gestation and late lactation (+9.7% and +8.7%, respectively; P<0.05). RFLP females produced more milk than R and RF females in the two first lactations (+18.5%; P<0.001). In the first three parturitions, R females delivered fewer kits born alive (-1.7 kits than RF and RFLP; P<0.05). In addition, R females¿ blood had a higher concentration of glutamine and glutamate than RFLP (+24% and +22.7%, respectively; P<0.05). RFLP litters were heavier than both R and RF litters throughout lactation. However, R kits were heavier at birth than RF and RFLP (+7.9 %). Results suggest that the foundation of a paternal line using elite animals could generate females with better early reproductive performance. In addition, backcrossing the RF line with a maternal LP line resulted in a genetic line whose females had a different resource allocation strategy to foster reproduction during the studied period.Financial support statement This study was funded by the Ministry of Science, Innovation and Universities of the Government of Spain (AGL2017-85162-C2-1-R) and the General Direction of Science and Research of the Generalitat Valenciana (AICO/2012/256)Peixoto Gonçalves, CA.; Martinez-Paredes, E.; Ródenas Martínez, L.; Larsen, T.; Corpa, J.; Blas Ferrer, E.; Cambra López, M.... (2023). Reproductive performance of rabbit females from three paternal lines with a different potential for growth rate and resilience. Animal. 17(6):1-10. https://doi.org/10.1016/j.animal.2023.10072911017

Efecto del Peso Molecular en la Formación del Polimorfo Beta en Polipropileno Isotáctico Metalocénico.

Existe un gran número de referencias relativas al efecto que la adición de agentes nucleantes, AN, en el polipropileno, iPP, supone en la generación de los distintos polimorfos, no existiendo estudios previos en el iPP metalocénico, m-iPP. Es objetivo de este trabajo llenar la laguna existente en dicha área, con el fin de mejorar la estabilidad térmica y la transparencia, acortar los ciclos de producción y optimizar las propiedades. Se han estudiado diferentes tipos de nucleantes de última generación que conllevan, en primer lugar, la formación de la celdilla monoclínica α y el aumento de la temperatura de cristalización, lo que acorta los ciclos de transformación. Para la evaluación exhaustiva5 de la forma β, objetivo de este trabajo, se ha utilizado como AN una mezcla de estearato cálcico y ácido pimélico (1:2), denominada a5. La competencia entre las formas α, β y γ en el m-iPP depende de la velocidad de cristalización y de la temperatura de cristalización isoterma5. Además, el contenido de AN β necesario para generar esta forma cristalina en el m-iPP es considerablemente superior en relación con el iPP sintetizado con catalizadores Ziegler-Natta, Z-N, debido a la coexistencia del polimorfo γ en el primero. La competencia entre las tres formas cristalinas en el m-iPP provoca que la generación de la forma β en función de la velocidad de enfriamiento sea, bajo ciertas condiciones, opuesta a la observada previamente en el iPP Z-N convencional. Estos resultados novedosos son de gran interés dado que han establecido las bases científicas sobre las que se cimenta el objetivo de la adición de AN β en los diferentes iPPs seleccionados, objeto de estudio en esta comunicación. Se han mezclado dos m-iPP con índices de fluidez, IF, de 15 y 30 g/min, suministrados por Basell, con un 0.3 % en peso de AN, en un mezclador interno a 190 ºC, 40 rpm y 10 min. Posteriormente, se han preparado filmes mediante moldeo por compresión en muestras sin y con AN. Las muestras se han enfriado desde el fundido a unos 100 ºC/min (entre platos de agua fría y presión), tratamiento Q y a 1.5 ºC/min (velocidad de enfriamiento de la prensa bajo presión), tratamiento S. La caracterización de la estructura y la competición entre las diferentes formas cristalinas se ha seguido mediante difracción de rayos X y DSC, mientras que el estudio de las propiedades mecánicas se ha realizado mediante DMTA y microdureza. En la figura se reproducen los difractogramas de RX para las muestras en estudio sin y con 0.3% de AN y tratamiento térmico S. Las muestras sin aditivar, sn, presentan polimorfismo, es decir, la coexistencia de las difracciones a 18.5 y 21.2º características de las celdillas cristalinas α y γ, respectivamente. Por otro lado, la presencia del AN a5 da lugar a una difracción adicional a 16.1º asociada a la fase trigonal β. La intensidad de dicha difracción es mayor para el polímero de menor peso molecular (mayor IF)

Comparison of immune response to lipopolysaccharide of rabbit does selected for litter size at weaning or founded for reproductive longevity

To evaluate differences in maternal lines to the immune response of reproductive rabbit does, a total of 64 animals of two different lines: (1) founded for hyper-longevity and litter size criteria (LP) and (2) selected for litter size at weaning (V) were used. Females were subjected to three different reproductive efforts: post-partum (PP) mating at first lactation and 9 kits during the second; post-weaning (PW) mating at first lactation and 9 kits during the second; and PW mating at first lactation and 5 kits during the second. At second weaning (30 days PP), an acute response was induced by intravenous infusion of lipopolysaccharide (LPS). LP females seemed to be lower affected during the hyper-acute phase than V females, showing lower plasma glucose content at 1.5 h post infusion (pi) and rectal temperature at 6 h pi; and showed higher ulterior immune response, with higher levels of C-reactive protein at 48 h pi and haptoglobin in plasma from 24 h pi. Survival test conferred a higher risk of culling for V than for LP females during the first hours after challenge. These results may suggest that, regarding immune response to LPS challenge, foundation by hyper-longevity productive criteria lead to obtain a more robust population of rabbit does, characterized by improved response ability. (C) 2013 Elsevier Ltd. All rights reserved.This study has been supported by the Interministerial Commission for Science and Technology (CICYT) from the Spanish Government. Grants Number: AGL2011-30170-C02-01; AGL2011-30170-C02-02), is gratefully acknowledged.Ferrian, S.; Blas Ferrer, E.; Larsen, T.; Sánchez Serrano, JP.; Friggens, NC.; Corpa, JM.; Baselga Izquierdo, M.... (2013). Comparison of immune response to lipopolysaccharide of rabbit does selected for litter size at weaning or founded for reproductive longevity. Research in Veterinary Science. 94(3):518-525. doi:10.1016/j.rvsc.2013.01.008S51852594

Genotypic characterization of Staphylococcus aureus strains isolated from rabbit lesions

Since staphylococcal infections are the main pathological problem in rabbit does, the objective of this study was to characterize epidemiologically Staphylococcus aureus isolates from different lesion types in rabbits. Using 3 genetic markers (coagulase, staphylococcal protein A and clumping factor B genes), 22 different genotypes were identified among 301 isolates recovered from 259 rabbit does with 10 different kinds of chronic purulent lesions. These infected rabbits were obtained from 30 herds located in the Valencia province on the Spanish Mediterranean coast. The most frequent genotype was designated A1/II1/δ (coa/spa/clfB combination genotype) and represented 70.76% of the isolates. Although most genotypes were previously identified in other countries, novel types were also documented. No specificity between genotypes and nature of the pathologic process could be identified. After genetic comparison between strains from different origins, the results may suggest that rabbit, bovine and human S. aureus isolates are not clonally related, suggesting that specific host-dependent pathogenic factors may have evolved independently in these species. These differences indicate that a rational and effective strategy to control infections caused by rabbit-specific isolates may be advantageous

Staphylococcal infections in rabbit does on two industrial farms

The main reasons for culling adult rabbit does on two Spanish rabbit farms were investigated for a year. The most important conditions were mastitis (33·3 per cent), followed by subcutaneous abscesses (9·9 per cent) and pyometra (8·7 per cent). Staphylococcus aureus infections were the most severe problem, the organism being isolated from 69·2 per cent of infected animals. Pasteurella species were more prevalent in cases of pyometra and pneumonia. Two strains of S aureus were identified by using polymorphism of the coagulase gene as the criterion. One of these strains was responsible for the majority of the staphylococcal infections and was isolated from several pathological processes