In vitro cytopathic effects of a cysteine protease of Tritrichomonas foetus on cultured bovine uterine epithelial cells

OBJECTIVE: To evaluate the cytopathic effects of Tritrichomonas foetus and a purified cysteine protease (ie, CP30) of T foetus on cultured bovine uterine epithelial cells (BUECs) in vitro. SAMPLE POPULATION: 10 reproductive tracts were obtained from late-term bovine fetuses at a commercial abattoir. PROCEDURE: An in vitro culture system of BUECs was developed to study the cytopathic effects of T foetus and purified CP30 of T foetus on host cells. Cytotoxicity of T foetus or CP30 on exposed BUECs was determined. Fluorescence microscopy and flow cytometry analyses were used to detect apoptosis. A fluorometric assay was used to detect BUEC caspase 3 activation. The CP inhibitor E-64 and a caspase inhibitor were used to inhibit apoptosis. RESULTS: Cytopathic effects were observed in BUECs treated with parasites or CP30 and were concentration and time dependent. The BUECs underwent apoptosis in the presence of parasites or CP30. The specific CP inhibitor E-64 abolished the induction of apoptosis in BUECs by CP30. The caspase inhibitor reduced the amount of apoptosis in BUECs. CONCLUSIONS AND CLINICAL RELEVANCE: T foetus and its CP30 induce apoptosis in cultured BUECs in vitro. Induction of apoptosis by CP30 is correlated with protease activity. Endometrial cell death as a result of a T foetus infection is likely to be more important in mediating infertility than a direct effect on the conceptus. Provoking an apoptotic reaction in the host may mitigate an inflammatory reaction or immune response and therefore favor survival of the parasite in a chronic infection.     

Influence of the Th2 immune response established by Nippostrongylus brasiliensis infection on the protection offered by different vaccines against Chlamydophila abortus infection

Chlamydophila abortus is the aetiological agent of enzootic abortion in small ruminants in which it infects the placenta to cause abortion during the last trimester of gestation. In a mouse model, a Th1 immune response involving IFN-gamma production and CD8+ T cells is necessary for the infection to be resolved. The authors previously demonstrated that infection with Nippostrongylus brasiliensis, a rodent gastrointestinal nematode extensively used in experimental models to induce Th2 responses, alters the specific immune response against C. abortus infection, increasing bacterial multiplication in liver and reducing specific IFN-gamma production. The aim of the present work was to clarify whether a Th2 immune response has any influence on the success of vaccination using both inactivated and attenuated vaccines. The results showed that the Th2 response established prior to vaccination did not influence the induction of protection offered by the vaccines. However, the effectiveness of this protective response can be altered, depending on the adjuvant employed in the inactivated vaccines, when the Th2 response is established after vaccination, just before challenge with C. abortus.     

Genotype by climate interaction in the genetic evaluation for growing traits of Braunvieh cattle in Mexico

The objective of this study was to determine the magnitude of genotype by climate interaction (GCI) in the national genetic evaluation for weaning (WW) and yearling (YW) weights of Mexican Braunvieh cattle. The numbers of performance records and animals in the pedigree were 12,364 and 25,173 for WW, and 7,991 and 18,072 for YW, respectively. Performance records were clustered based on climatological variables into: dry tropic (DT), wet tropic (WT), and temperate (TE) climates. Animal models were used to estimate genetic parameters and predict breeding values in each of the climates. Bivariate analyses were carried out for pairwise combinations of climates on each trait, considering the same trait in different climates as a different trait. Criteria to evaluate GCI were genetic correlations (r _g), correlations between predicted breeding values (r _BV), and frequencies of coincidence (FC) in the ranking of the top 25 sires. Results of comparisons between pairs of climates were variable, depending on specific cases. For WW, the r _g, r _BV, and FC ranged from ?0.36 to 0.84, ?0.60 to 0.97, and 0.16 to 0.92, respectively; whereas for YW, they fluctuated between 0.23 and 0.99, 0.33 and 1.00, and 0.60 and 1.00, respectively. For both traits, the results suggest absence of GCI between DT and TE; however, GCI was detected in the other pairs of climates, where WT was involved. To maximize genetic progress, the joint genetic evaluation should be performed only for animals with performance data in DT and TE, whereas a separated evaluation is suggested for animals with performance records generated under WT conditions.     

A retrospective study of pathologic findings in the Amazon and Orinoco river dolphin (Inia geoffrensis) in captivity.

River dolphins are especially susceptible to negative human impacts. For their conservation, attempts of relocation or procreation ex situ may become important in the future to avoid their extinction. Additional knowledge and medical experiences of river dolphin management in captivity may aid such conservation efforts. The medical records and necropsy and histopathology reports on 123 captive Amazon River dolphins (Inia geoffrensis) were re-viewed. Of these 123 animals, 105 were necropsied and 70 necropsies were supported with histopathology. Eighteen animals were not necropsied. Among wild-born animals, mortality was highest in the first 2 mo immediately postcapture and transport, accounting for 32 of 123 deaths. Pneumonia and skin lesions (cutaneous and subcutaneous ulcerations and abscesses) were the most common findings, found in 44 of 105 (42%) and 38 of 105 (36%) of gross diagnoses, respectively. At least 10 of 44 cases of pneumonia diagnosed grossly included a verminous component. Cachexia, from a variety of causes, was a major gross finding in 21 animals. Fifteen animals had histologic evidence of significant renal pathology, and this was the primary cause of death in 13 cases. Hepatic pathology was found in 18 cases, and bacterial sepsis was confirmed via histology in 16 cases. Based on these findings, it may be concluded that keys to successful maintenance of this species include 1) prophylactic anthelminthic and antibiotic therapy immediately post-capture; 2) maintenance of animals in larger enclosures than in past attempts, in compatible groups, and in facilities capable of separating aggressive animals; 3) maintenance in microbiologically hygienic water quality at all times; and 4) a proactive program of preventive medicine during the immediate postcapture, quarantine, and maintenance period of captivity.     

Granulocyte and granulocyte macrophage colony-stimulating factors as therapy in human and veterinary medicine

Granulocyte colony-stimulating factors (G-CSFs) and granulocyte macrophage colony-stimulating factors (GM-CSFs) are endogenous cytokines that regulate granulocyte colonies and play a major role in the stimulation of granulopoiesis (neutrophils, basophils and eosinophils) and in the regulation of microbicidal functions. There are numerous pathological conditions in which neutrophils are decreased, the most common being neutropenia associated with cancer chemotherapy, which increases the risk of serious microbial infections developing with the potential for high morbidity and mortality. New methods in molecular biology have led to the identification and cloning of CSF genes and biopharmaceutical production. Since then, CSFs have been widely used for the prevention and treatment of neutropenia associated with cancer chemotherapy, for mobilising haematopoietic cell precursors, and for other neutropenia-related pathologies. This review focuses on the use of CSFs within both human and veterinary medicine. Clinical applications, pharmacology, tolerability and the potential role of these factors in veterinary medicine are considered.     

Quantification of mucosa-adhered microbiota of lambs and calves by the use of culture methods and fluorescent in situ hybridization coupled with flow cytometry techniques

The intestinal mucosa-associated microbiota could play important biological roles due to its close proximity with the animal host, but knowledge on its composition is still limited. The aim of this study was to characterize the microbial communities tightly associated with different parts (rumen, duodenum and colon) of the gastrointestinal tract (GIT) of healthy lambs and calves by using both cultural, and fluorescent in situ hybridization-flow cytometry (FCM-FISH) techniques. Lactic acid bacteria genera were one of the predominant bacteria detected in lambs and calves by both methodologies, possibly constituting an index of their healthy status. The levels of Lactobacillus were significantly higher (p<0.05) in the rumen and duodenum of lambs, and in the rumen of calves. The levels of Bifidobacterium were significantly higher (p<0.05) in the colon of both animal species and the rumen of lambs. Significant differences (p<0.05) were found in counts of other microbial groups (yeast, Enterococcus, Propionibacterium, Bacteroides, Clostridium and Enterobacteriaceae) at diverse GI sections depending on the animal species. In general, microbial counts follow the same trends regardless the applied technique. The most remarkable differences were found in detection levels of Bacteroides and Clostridium, which tended to be significantly higher (p<0.05) when analysed by FCM-FISH. This technique also allowed the detection of quantitatively important bacteria (sulphate-reducing bacteria, Atopobium and Coriobacterium), which are difficult to cultivate in selective medium. Therefore, FCM-FISH has been proven to be a sensitive high throughput approach that provides additional information to that obtained by traditional culture techniques about the complexity of the GI ecosystem of these animal species.     

Comparison of the agar gel immunodiffusion test and ELISA in the detection of bovine leukosis virus antibody in cattle persistently infected with bovine virus diarrhoea virus

When six cattle persistently infected with bovine virus diarrhoea virus (BVDV) were inoculated with lymphocytes infected with bovine leukosis virus (BLV), a depressed antibody response to BLV was observed by ELISA which was due to a decrease in IgG1 synthesis. The ELISA was more sensitive and more reliable than the agar gel immunodiffusion (AGID) test in detecting BLV infection in cattle persistently infected with BVDV. Decreased antibody responses were manifested in the AGID test by negative, inconclusive or weakly positive reactions: only two of the six cattle developed antibodies that generated positive AGID reactions.     

Journey length and high temperatures: effects on rabbit welfare and meat quality

The transport of domestic animals by road can increase levels of stress and decrease meat quality, especially in unfavourable climates. The purpose of this study was to investigate the effect of journey duration and vertical position on the transport truck on some physiological indicators of stress and on instrumental meat quality parameters in commercial rabbits. In the summer months (June and July, 2003), 78 rabbits were subjected to either long (7 h) (LJ) or short (1 h) (SJ) journeys (3 replicates each, n = 6) between the farm and an abattoir in northern Spain. The position (top, middle, or bottom) occupied by the rabbits on the Multi-Floor cage Rolling Stand (MFRS) of the transport truck was recorded. Blood samples were collected at sticking and meat pH was measured at 24 h post-mortem (pH24). At 48 h post-mortem, samples of the M. longissimus dorsi were used to determine water-holding capacity (WHC) and instrumental tenderness using an INSTRON machine. The levels of corticosterone, glucose, lactate, and creatine kinase were slightly higher in LJ than in SJ samples, but the difference was not statistically significant (p < or = 0.10). Independent of journey length, rabbits in the middle and bottom of the MFRS showed higher levels (p < or = 0.05) of glucose and creatine kinase (middle), and corticosterone (bottom) than the rabbits located at the top floor. The pH 24 and WHC values of the SJ and LJ rabbits did not differ significantly. Journey length had a significant effect (p < or = 0.01) on meat tenderness. The meat from rabbits subjected to LJ had higher values of maximum stress and total toughness than did the SJ rabbits (p < or = 0.05). There were similar differences (p < or = 0.05) between LJ and SJ rabbits in their stress values of compression at 20% and 40% (measures of the tenderness of raw meat). In hot weather, the position on the transport truck appeared to have a greater effect on rabbit welfare than the duration of the journey.