RESUMO
Seven dairy cattle farms from eastern Antioquia were tested for mastitis in a cross-sectional study with a non-probabilistic convenience sampling procedure. Each udder quarter of 290 lactating cows was evaluated through the California Mastitis Test in order to determine the prevalence of subclinical mastitis. Milk from positive quarters underwent somatic cell count (SCC), cell culture and antibiotic sensitivity tests. The prevalence of subclinical mastitis per quarter was 19.9% (228 quarters). Only 11 quarters (0.95%) had clinical mastitis. The average SCC for all quarters was 1,105,733 cells/mL. Streptococcus dysgalactiae was the most common bacteria observed (29.5%) in the 226 cultures evaluated, followed by coagulasenegative staphylococci (CNS, 23%), and Staphylococcus aureus (10.3%). The frequency of contagiouspathogens and environmental pathogens was 37.8% and 49.3%, respectively. This study confirms that mastitis remains elevated in this region, suggesting a continuous lack of milking hygiene and education of farm personnel.
Se realizó un estudio descriptivo de corte, y se hizo un muestreo no probabilístico de conveniencia, en siete fincas de ganado de leche localizadas en el oriente antioqueño. Se evaluó cada cuarto de 290 vacas en producción láctea mediante la realización del California Mastitis Test (CMT) con el fin de determinar la prevalencia de mastitis por cuarto y por vaca. A la leche proveniente de los cuartos positivos mayores a trazas, se les realizó recuento de células somáticas (RCS), cultivo y antibiograma. La prevalencia de mastitis subclínica por cuarto fue de 19.9% (228 cuartos) y 11 cuartos (0.95%) presentaron mastitis clínica. El promedio del RCS para todos los cuartos fue de 1.105.733 céls/ml. En los 226 cultivos, Streptococcus dysgalactiae fue la bacteria más común (29.5%), le siguieron estafilococos coagulasa negativo (ECN) (23%) y Staphylococcus aureus (10.3%). La frecuencia de patógenos contagiosos fue 37.8%, entre tanto que la de ambientales fue 49.3%.
Foi realizado um estudo de corte, e se realizou uma amostragem não probabilística em sete fazendas de gado leiteiro localizado no leste da Antioquia. Foram avaliados trimestralmente 290 vacas em produção de leite mediante a implementação do California Mastitis Test (CMT) para determinar a prevalência de mastite subclínica em cada quarto da vaca. Nos quartos positivos foi realizada a contagem de células somáticas (CCS) no leite, o cultivo microbiológico e análises de sensibilidade. A prevalência de mastite subclínica por quarto foi de 19.9% (228 quartos) e 11 (0.95%) apresentaram mastite clínica. A CCS média para todas os quartos foi 1.105.733 células / ml. Em 226 cultivos, o Streptococcus dysgalactiae foi a bacteria mais comum (29.5%), seguido por estafilococus coagulase negativo (ECN) (23%) e Staphylococcus aureus (10.3%). A reqüência de agentes patogénicos contagiosos foi de 37.8% e patógenos ambientais foi de 49.3%.
RESUMO
Although vesicular stomatitis has been present for many years in the Americas, many aspects of its natural history remain undefined. In this study, we challenged five adult Virginia opossums (Didelphis marsupialis) with vesicular stomatitis New Jersey serotype virus (VSNJV). Opossums had no detectable antibodies against VSNJV prior to being inoculated with 10(6.5) median tissue culture infective doses (TCID(50)) of VSNJV by two routes; intraepithelial/subepithelial (IE/SE) inoculation and scarification in the muzzle (SM). Clinical response was monitored daily and animals were tested for viral shedding. All infected animals developed vesicles and ulcers on the tongue and inflammation of the nasal alar folds. Virus was isolated from esophagus-pharynx, nasal, and from ocular swabs and lesions samples. The failure to detect viremia in these animals indicates that a source other than blood may be required for transmission to insect vectors. Our results suggest that D. marsupialis could play a role in the maintenance of VSNJV outside of domestic animal populations and could provide a model to study vesicular stomatitis virus pathogenesis.
