Brucellosis has been an endemic disease of cattle and humans in Costa Rica since the beginning of XX century. However, brucellosis in sheep, goats, pigs, water buffaloes, horses and cetaceans, has not been reported in the country. We have performed a brucellosis survey in these host mammal species, from 1999–2016. In addition, we have documented the number of human brucellosis reported cases, from 2003–2016. The brucellosis seroprevalence in goat and sheep herds was 0.98% and 0.7% respectively, with no Brucella isolation. Antibodies against Brucella were not detected in feral or domestic pigs. Likewise, brucellosis seroprevalence in horse and water buffalo farms was estimated in 6.5% and 21.7%, respectively, with no Brucella isolation. Six cetacean species showed positive reactions against Brucella antigens, and B. ceti was isolated in 70% (n = 29) of striped dolphins (Stenella coeruleoalba). A steady increase in the diagnosis of human brucellosis cases was observed. Taking into account the prevalence of brucellosis in the various host mammals of Costa Rica, different measures are recommended.
In tropical and subtropical regions of the world, parasitic diseases are a main cause of losses in livestock productivity. The increased acquired resistence to anthelmintics by gastrointestinal nematodes, requires biological control be considered as a potential feasible and effective alternative. The most effective natural soil enemies of nematodes are nematophagous fungi. In order to collect and identify predator nematophagous fungi (PNF), samples were obtained from 51 farms distributed throughout the seven provinces of Costa Rica. The origin samples included: soil from different crops (potatoes, tomatoes, bananas, ornamental plants, squash and coffee); animal feces (cattle, sheep, goat and horse); soil and fallen leaves from forest; and plants with signs of nematode infection. Each sample was processed using three techniques for the extraction of fungi from soil: sprinkling technique, soil dilution and humidity chamber. Twenty four strains of nematophagous fungi were found in 19 farms; 83.3% of the fungi were isolated by sprinkling technique. The following fungi were idenified: Arthrobotrys oligospora (n=13); Candelabrella musiformis (n=9); and for the first time there was isolation of A. conoides (n=1) and A. dactyloides (n=1) in the country. Moreover, 16 strains from Trichoderma (n=13), Beauveria (n=1), Clonostachys (n=1) and Lecanicillium (n=1) were obtained. In addition, pH of each possible fungal isolation source was measured, and it varied from 5.2 to 9.9, however PNF isolates fell within the range of 5.6 to 7.5. The PNF strains were cultivated in four different media for the production of chhlamydospores: potato dextrose agar (PDA); corn meal agar (CMA); malt extract agar (MEA) and potato carrot agar (PCA). Out of these cultures, 95.8% of the strains formed chlamydospores primarily in the PCA. Of these strains, the profilic spore producers were subjected to ruminant artificial gastrointestinal conditions. A total of 14 fungi were tested, out of which 42.9% survived the digestive analysis. Neither A. conoides nor A. dactyloides were viable following the in vitro gastrointestinal test. The PNF isolated in this study demostrated an action against ovine and caprine gastrointestinal nematodes and are candidates for use in biological control of these organisms. Among these microorganisms, Candelabrella musiformis appears to be the most promising fungi for use as a biological control agent in
The presence of antibodies against Toxoplasma gondii and Neospora caninum were analyzed in 392 sheep sera from ten Costa Rican ovine flocks using indirect immuno-enzymatic assays. Additionally, general information about sheep management, environment, and clinical reproductive disorders was assessed through a questionnaire to inquire factors related to these apicomplexan parasites. A total of 161 (41.1%) serum samples reacted positive to T. gondii, 43 (10.9%) to N. caninum and 26 (6.63%) to both parasites. Toxoplasma gondii serorreactors were detected in all the analyzed flocks (100.0%), meanwhile N. caninum antibodies were found in nine flocks (90%), from the six Costa Rican regions. Factors associated with T. gondii were the co-presence of cattle (OR = 5.06; C.I.95%; 2.08–12.30; p: <0.001), grey foxes (Urocyon cinereoargenteus) and opossums (Didelphis marsupialis) (OR = 2.44; C.I.95%; 1.50–3.95; p: <0.001) inside or around the farms, and the presence of peccaries (Tayassu sp.) (OR = 0.35; C.I.95%; 0.16–0.74; p: 0.0058) was a variable associated with N. caninum seropositivity. The obtained results of T. gondii and N. caninum infections in sheep flocks from Costa Rica should be considered for the proper prevention and control strategies against these apicomplexan abortive parasites.
a b s t r a c tA total of 359 sheep serum samples from 15 farms were analyzed for the presence of antibodies against Maedi Visna Virus (MVV) by Enzyme-linked Immunosorbent Assay (ELISA). Additionally, a survey was applied to the sheep owners in order to determine management measures and presence of clinical symptoms of Maedi-Visna in the flocks. Logistic regression with random effects was performed to assess risk factors to seropositivity. Seven serum samples were positive to MVV belonging to six flocks, determining low flock seropositivity (0 to 7.1%). Only one of the five regions studied was negative, determining low overall prevalence (1.95%) and low positivity by region (0.0% to 0.84%). One seropositive animal with symptoms related to MVV was sacrificed for necropsy. An enlargement of mesenteric and celiac lymph nodes was determined, histopathology of lungs revealed acute interstitial pneumonia. Analysis of organs, fluids and blood of this sheep by Polymerase Chain Reaction (PCR) to detect MVV yielded negative results. In order to confirm the serological results, serum and blood samples from two remaining seropositive animals were analyzed six months later, one resulted seronegative and the other seropositive in ELISA, but both negative in PCR. No risk factors were associated to seropositivity. Since MVV produces latency, we conclude, that the positive serological results were due to false positive reactions. Even though, 52.0% of the participating farms had introduced animals, embryos, or semen from other farms or from abroad without any sanitary certification, MVV seems to be present in Costa Rica probably in a very low prevalence. Further studies are required to implement control measures and prevent the spread of the disease.
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