Clinical and pathological examination of mycotoxicosis as an associated risk factor for colic in equine.

A retrospective cohort study was conducted on two Egyptian horse farms with most of horses were suffered from abdominal pain to describe the associations between the occurrence of mycotoxicosis and equine colic. The farms owner complain was an unexpected increase in number of colic cases and deaths among horses. The association between colic and risk factors (sex, type of food either dry or mixed with roughages and hematobiochemical parameters) was compared using independent sample T-test. The associations between possible prognostic indicators for colic caused by mycotoxicosis was estimated using logistic regression analysis model. The cumulative incidence, incidence rates for colic attacks, survival rate among diseased horses were additionally estimated. Our results showed that a total of 24 out of the 132 horses suffered from colic due to feeding of ration contaminated with high percent of mycotoxin including Aflatoxins, Ochratoxins and or fusarium mycotoxins. The total cumulative incidence of colic due to mycotoxicosis was 19.7%. The horses fed on dry rations had more chance of developing colic than horses fed on mixed rations (P < 0.05). The overall incidence rate of colic due to mycotoxicosis was estimated at 18 colic attack/1000 horse/month. The mortality rate of horses suffered from colic due to mycotoxicosis was estimated at 5.9% (5/85), while the case fatality rate was estimated at 25% (n = 5/20). Inconclusion, our results showed that mycotoxicosis are considered an important risks factor for colic cases development in equine practice.

Prevalence and seasonal variation of Fasciola hepatica in slaughtered cattle: the role of climate and environmental factors in Mexico.

The objective of this study is to determine the prevalence of Fasciola hepatica infection in cattle slaughterhouses, as well as its association with climatic/environmental factors (derived from satellite data), seasonality and climate regions in two states in Mexico. Condemned livers from slaughtered animals were obtained from three abattoirs in the states of Puebla and Veracruz. The overall prevalence of the parasite in cattle between January and December of 2017 was 20.6% (1407 out of 6834); the highest rate of condemnation was observed in Veracruz (26.3%; tropical climate), and the lowest rate was found in Puebla (15.5%; temperate climate). The seasonal prevalence of fluke infection was 18.6%, 14.8% and 28.4% during the wet season, and 17.1%, 12.4% and 22.8% during the dry season in the three abattoir sites, located in the districts of Zacatlán, Teziutlán and Ciudad Alemán, respectively. Liver condemnations due to bovine fasciolosis were prevalent in the Zacatlán, Teziutlán and Ciudad Alemán districts during summer, autumn and summer, respectively. Using generalized estimating equations analysis, we determined six variables - rainfall (wet/dry), land surface temperature day, land surface temperature night, normalized difference vegetation index, seasonality and climate regions (temperate/tropical) - to be significantly associated with the prevalence of condemned livers. Climate region was the variable most strongly associated with F. hepatica infection (odds ratio (OR) 266.59; 95% confidence interval (CI): 241.90-353.34), followed by wet and dry seasons (OR 25.56; 95% CI: 20.56-55.67).

New records of helminth parasites of nine species of waterfowl in Mexico, and a checklist of the helminth fauna of Anatidae occurring in Mexican wetlands.

Wild and domestic populations of waterfowl garner economic benefits, as they are hunted for human consumption or as a recreational activity. Waterfowl migrate to their wintering grounds in Mexican wetlands where habitat conditions are more favourable. In this study, we present a list of helminth species sampled from the gastrointestinal tract of 59 wild birds belonging to the family Anatidae in three localities of Mexico, and a checklist of the helminth parasite fauna of the members of the family in the whole country, built from literature records. After helminthological examination, 25 taxa were identified: eight trematodes; four cestodes; 12 nematodes; and one acanthocephalan. Obtained records dated from 1943 to 2019. Our literature search yielded 563 records corresponding to 95 parasite taxa: 38 trematodes, 24 cestodes, 23 nematodes and ten acanthocephalans. In Mexico, 17 anatid species have been studied for helminths. Records correspond to 55 locations from 20 Mexican states. An insight gained from the collated literature and recent records was that trematodes represent the most diverse parasite group in anatids in Mexico. We briefly discuss that the information about helminths parasitizing waterfowl will be useful for understanding the effect of habitat loss and pollution of wetlands where migratory birds spend the breeding season, for addressing ecological programs aimed to guarantee the health and conservation of North American migratory birds or the effect of bird migration in the composition of the helminth parasite communities, and for freshwater biologists interested in the understanding of freshwater ecosystem health.

Ixodicide activity of Eysenhardtia polystachya against Rhipicephalus (Boophilus) microplus.

The objective of this study was to evaluate the acaricidal effect of 2 compounds extracted from Eysenhardtia polystachya in vitro, namely coatlines and matlalines. Each extract was obtained by aqueous extraction in a nitrogen atmosphere. Engorged adult females of an amitraz-resistant strain of Rhipicephalus (Boophilus) microplus were used to produce larvae and to carry out the adult immersion test (AIT), while larvae were assayed using the larval packet test (LPT). After exposure to coatlines or matlalines, the mortality of larvae and engorged females, as well as the reproductive parameters of adult ticks were assessed. Coatlines were not lethal against larvae and did not decrease reproductive parameters. Conversely, matlalines showed a 90 to 100% efficacy against adults and larvae at all concentrations tested and a reduction of 76.41 to 80.64% oviposition and a 48.02 to 54.86% reduction in egg hatchability. Therefore, the acaricidal activity of matlalines was more efficient. Further studies are required to elucidate both the mode of action of matlalines as well the structure-activity relationships responsible for the observed differential efficacy between these 2 related isoflavans against the cattle tick.

Pharmacodynamic evaluation of a reference and a generic toltrazuril preparation in broilers experimentally infected with Eimeria tenella or E. acervulina.

Abstract 1. The aim of this study was to investigate the effects on pigmentation, faecal oocyst output, immune responsiveness and reactive oxygen species (ROS) generation following treatment with either the reference toltrazuril (Baycox) or a generic preparation (gen-TTZ), during an experimental Eimeria tenella (Et) or E. acervulina (Ea) infection of 210 Ross broiler chickens. 2. Results showed a significant difference on the anticoccidial efficacy 6 d after treating infected animals with Baycox (Et: 99.69% and Ea: 99.52%) or gen-TTZ (Et:85.71% and Ea 81.81%). 3. Gen-TTZ-treated animals were less strongly carotenoid-pigmented than Baycox-treated broilers. Mean plasma carotenoid concentrations were significantly higher in groups treated with Baycox than in broilers given gen-TTZ. 4. Treatment of animals with Baycox led to a significant decrease in ability of the peripheral blood mononuclear cells to produce ROS in contrast to gen-TTZ-treated groups. Baycox, but not generic toltrazuril, increased IL-10 and decreased tumour necrosis factor alpha (TNF-α) concentrations in chickens infected with E. tenella and E. acervulina. 5. It is suggested that differences in anticoccidial efficacy may be observed when using a generic toltrazuril product. Hence, in addition to plasma profiles of drugs, standardised clinical control tests may be necessary for generic formulations, particularly if other parameters are important to achieve a better control of coccidiosis.

Cytokine gene expression and NF-kappaB activation following infection of intestinal epithelial cells with Eimeria bovis or Eimeria alabamensis in vitro.

In cattle, Eimeria produces clinical disease with different degrees of severity, depending on the dominant species. Eimeria bovis triggers severe intestinal damage, while E. alabamensis causes minimal damage. Cytokines and other factors derived from epithelial cells play important roles in inflammatory and immune responses in intestinal tissue. This study aimed to obtain a detailed view of IFN-gamma and IL-4 mRNA expression as well as of activation of NF-kappaB p50 and p65 subunits induced by E. bovis or E. alabamensis in intestinal epithelial cells by means of a RT-PCR assay and a NF-kappaB p50/p65 ELISA-based kit, respectively. Our results demonstrate that infection by both Eimeria species enhances IL-4 mRNA expression in intestinal cells. However, IL-4 was expressed more intensely in cells incubated with E. bovis whereas IFN-gamma levels were higher and detected at an earlier time in cells infected with E. alabamensis. NF-kappaB was activated in infected cells irrespective of species, yet the activity of the p50 subunit was significantly higher in cells incubated with E. bovis. Our results suggest that the intensity of host-cell responses triggered by these two Eimeria species could be considered as potential determinants of pathogenicity.

Downregulation of the goat beta-defensin-2 gene by IL-4 in caprine intestinal epithelial cells infected with Eimeria spp.

Defensins are antimicrobial peptides that are produced by leukocytes and epithelial cells. Recent advances indicate that these peptides play an important role in innate immune responses. Nonetheless, the role of defensins in caprine eimeriosis remains unknown. Therefore, this study investigated the expression of a goat beta-defensin, named GBD-2 in caprine intestinal epithelial cells (CIEC) stimulated with recombinant bovine interferon-gamma (IFN-gamma) in the presence or absence of recombinant bovine interleukin-4 (IL-4) by a reverse transcriptase-polymerase chain reaction (RT-PCR) assay. GBD-2 mRNA was clearly expressed in IFN-gamma-stimulated CIEC. On the other hand, the direct addition of IL-4 showed no significant effect on GBD-2 expression in CIEC. However, when supernatants from peripheral blood mononuclear cells (PBMC) cultured with IL-4 were added to CIEC, the expression of GBD-2 decreased. To elucidate if IFN-gamma functions as a signaling molecule that facilitates the generation of GBD-2 against Eimeria spp. in goats, anti- IL-4 was added to PBMC from Eimeria-infected goats and levels of IFN-gamma in culture supernatants were determined by an enzyme-linked immunosorbent assay test. Results showed that IFN-gamma secretion increased when anti-IL-4 was added to PBMC. It then appears safe to suggest that IL-4 may be a further factor in the pathogenesis of goat coccidiosis and its induction may be part of an evasion strategy of the parasite to avoid pro-inflammatory responses.

Serine protease activity demonstrated in the larval stage of the pentastomid Linguatula serrata.

Linguatula serrata is a cosmopolitan parasite whose intermediate hosts are cattle, goats, sheep, and other ruminants. The adult form is found in the nasal airways, frontal sinuses, and tympanic cavity of canines and felines, and it produces hemorrhages and breathing difficulties. To elucidate if L. serrata produces enzymes that are capable of degrading tissues from the intermediate host, proteolytic activities in larval products were studied. Using the zymography technique, one major protease was detected in parasite in vitro-released products with an approximate molecular weight of 75 kDa. This enzyme was inhibited with phenylmethylsulfonyl fluoride, suggesting that it is a serine protease, which was also shown to degrade type I collagen. The serine protease exhibited maximal activity at alkaline pH and temperatures varying from 37 to 45 degrees C. To gather evidence about the physiological roles of the enzyme, further biochemical and functional studies are suggested.