Artículos Científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14635

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Characterization of Anaplasma spp. infection in dogs from Costa Rica
(Universidad Nacional, Costa Rica, 2017-02-09) Dolz, Gaby; Bonilla, Marta C.; Campos-Calderón, Liliana; Jiménez Rocha, Ana Eugenia; Romero-Zúñiga, Juan José; Alberti, Alberto; ZOBBA, Rosanna
A cross-sectional study combining serological and molecular techniques for detecting selected Anaplasma species was conducted between 2011 and 2012 in dogs and ticks sampled in all provinces of Costa Rica. Global Anaplasma spp. seroprevalence was 2.7% (11/408) by indirect immunofluorescence assay. The 16S rRNA PCR confirmed active A. phagocytophilum infection only in one dog (0.3%, 1/374); however, the same sample was negative to groEL PCR. Out of 122 Rhipicephalus sanguineus s.l. ticks analyzed, one (0.8%) was found positive to A. phagocytophilum 16S rRNA PCR but negative when tested by groEL PCR; this tick was collected from a seronegative and PCR negative dog. Both 16S rRNA sequences were 100% (510/510 bp) identical to A. phagocytophilum strains isolated in different countries from different hosts. The presence of A. platys was established in four dogs (1%, 4/374) by both 16SrRNA and groEL PCR. Ticks collected from the same dogs tested negative by PCR. The 16S rRNA sequences were 100% identical to the corresponding sequences of A. platys strains isolated from dogs in Croatia and Brazil, however groEL sequences showed variable similarity levels (99–100%) with different strains of A. platys isolated in Chile, Japan and Thailand, pointing out the possible presence of different variants in Central America. Collectively data indicate low prevalence of A. phagocytophilum and A. platys in dogs from Costa Rica. Furthermore, infections seem to occur without clinical signs but with some hematological changes, and seem to resolve without treatment.
Effect of neosporosis on productive and reproductive performance of dairy cattle in Costa Rica
(Elsevier B.V, 2005-12) ROMERO-ZUÑIGA, JUAN JOSÉ; Van Breda, S.; Vargas, Bernardo; Dolz, Gaby; Frankena, K.
A cross-sectional study was conducted to assess the effect of neosporosis on productive and reproductive parameters in dairy cows. Cows (n = 2743) from 94 farms located in the most important dairy areas in Costa Rica were used in the study. The size of the herds ranged from 32 to 379 females (mean = 110, median = 125). An indirect ELISA was used to determine the serostatus of the cows towards Neospora caninum. The effect of neosporosis on milk production was analysed by a mixed linear model. In addition, the effects on calving interval (days) and calving to conception interval (days) were analysed by survival analysis. The risk of abortion in relation to N. caninum serostatus was assessed by logistic regression, with herd as a random effect. Overall, 1185 of 2743 cows (43.3%) were seropositive for Neospora. Eighty-nine of 94 (94.7%) farms were classified as Neospora-seropositive. It was estimated that cows seronegative to Neospora produced an additional 84.7 L of milk (P = 0.6). Serostatus did not have a significant effect on the length of the calving interval in the Cox proportional hazard survival analysis (Hazard ratio = 1.2, 95% CI: 0.9, 1.4). The logistic regression model had a weak positive association between serostatus and abortion (OR 1.7, 95% CI: 0.8, 3.9), but did not show a strong association between serostatus and the number of services per conception (OR = 0.95, 95% CI: 0.7, 1.3). In conclusion, there were no significant effects of Neospora serostatus on production and reproductive performance in this study.
Environmental factors associated with Dictyocaulus viviparus and Fasciola hepatica prevalence in dairy herds from Costa Rica
(Universidad Nacional, Costa Rica, 2017-06-15) Dolz, Gaby; Jiménez Rocha, Ana Eugenia; Argüello-Vargas, Silvia; Romero-Zúñiga, Juan José; Sequeira-Avalos, J.A.; Montenegro Hidalgo, Víctor M.; Schnieder, T.
Dictyocaulosis and fasciolosis are parasitic diseases that cause considerable economic losses for owners of farm animals worldwide, with special relevance on fasciolosis because it is an emerging zoonosis. Indirect diagnosis of these diseases through analyses of bulk milk tank samples has allowed carrying out large-scale prevalence studies, while the use of geographical information systems has helped to visualize and determine those variables that affect distribution of these pathogens. This study is intended to describe the spatial distribution of Dictyocaulus viviparus and Fasciola hepatica in dairy herds from Costa Rica, as well as their associated environmental factors. Bulk milk tank samples from 526 dairy herds in the three most important dairy regions of Costa Rica were analyzed using enzyme immunoassays. Results from the farms were subjected to spatial analyses using Holdridge's life zones, relief and soil type environmental layers. Of the total bulk milk tank samples analyzed, 3.8% (n=20) and 3.6% (n= 19) were positive for D. viviparus and F. hepatica, respectively. Moran's I analysis revealed the existence of potential cluster (Moran's I =1.789, z =12.726 p < 0.05) for D. viviparus. Consequently, Getis-Ord General G analysis showed that the spatial distribution of positive farms in the dataset was clustered (Observed General G= 0.015, variance =0.000001, z =12.823, p < 0.05). No significant positive spatial autocorrelation (Moran's I= 0.038, z =0.286, p > 0.0.5) was observed for F. hepatica. Furthermore, a significant difference was detected in the spatial locations of both parasites (latitude p < 0.05, longitude p < 0.05), and about the spatial distribution of both D. viviparus negative and positive farms (latitude p < 0.05, longitude p < 0.05), as well as in F. hepatica negative and positive farms regarding on latitude (p < 0.05), but not on longitude (p > 0.05). In the case of environmental factors, significant differences were found for D. viviparus and F. hepatica with respect to types of soil, precipitation, altitudinal belts, life zones, biotemperature, and elevation.
First Report of Campylobacter hepaticus Isolation in Laying Hens and Broiler Breeders with Spotty Liver Disease in Costa Rica
(American Association of Avian Pathologists, 2023-04) Quesada-Vásquez, Dioney; Jimenez-Madrigal, Laura; Chaves-Hernandez, Aida Jeannette; MUNOZ VARGAS, LOHENDY; BARQUERO-CALVO, ELIAS
Poultry producers in Costa Rica have informally reported a spotty liver disease–like syndrome for more than 20 yr. However, despite many attempts, the infectious agent responsible for this syndrome had not been identified. Therefore, following current knowledge of spotty liver disease diagnosis, we invited veterinarians and poultry producers to submit samples to the diagnostic laboratories of the Veterinary Medicine School, Universidad Nacional, to identify the infectious agent of this syndrome. Veterinarians and poultry producers were instructed to collect gallbladders and livers aseptically and send them for pathology examinations and bacterial cultures in less than 24 hr after collection. Samples were processed for standard histopathologic studies and cultured under aerophilic, anaerobic, and microaerophilic conditions. Campylobacter-like colonies were isolated and identified by biochemical and PCR tests. Here we report for the first time the isolation, biochemical characterization, and molecular confirmation of Campylobacter hepaticus in laying hens and broiler breeders with spotty liver disease in Costa Rica.
Free-living hard ticks (Ixodida: Ixodidae) from three different natural environments of Costa Rica
(Elsevier, 2021) Montenegro, Víctor M.; Delgado, Mónica; Miranda, Roberto; Vargas Muñoz, Mariana; Domínguez, Lillian; Bermúdez, Sergio
This paper presents data on free-living ticks collected by flagging and using CO2 traps in three natural areas in Costa Rica: Carara National Park (CNP), Palo Verde National Park (PVNP), and a Private Forest Reserve in Sarapiquí (SPR). Data were analyzed calculating aspects of alpha diversity (species richness, entropy; dominance index, and evenness); and for beta diversity, compositional similarity between communities of ticks was also calculated. We collected 12,795 ticks belonging to 10 species: Amblyomma coelebs, Amblyomma dissimile, Amblyomma mixtum, Amblyomma naponense, Amblyomma cf. oblongoguttatum, Amblyomma cf. parvum, Amblyomma sabanerae, Amblyomma tapirellum, Haemaphysalis juxtakochi and Ixodes affinis. The number of species and individuals varied between sites: 5970 ticks were collected in CNP, 4443 in PVNP, and 2382 in SPR. Amblyomma cf. oblongoguttatum and A. cf. parvum were collected at all three sites, but A. mixtum was the most abundant species, even though it was not collected in SPR. Values of alpha diversity were calculated for CNP and SPR, while diversity in PVNP was the lowest of the three locations. Evenness was highest in SPR and lowest in CNP. The only community that presented dominance was PVNP. Beta diversity showed low similarity between the three locations with the lowest being CNP and SPR. For the three localities, estimates of the number of tick species based on presence/absence data was higher using flagging than CO2; and considering the stage of the ticks collected. More larvae were captured using CO2 traps than by flagging, while flagging was better for col- lecting adults. To our knowledge this is the first study in Costa Rica that compares these two sampling methods in three different environmental areas.
Lutzomyia longipalpis is a Species Complex: Genetic Divergence and Interspecific Hybrid Sterility among Three Populations
(American Society of Tropical Medicine and Hygiene, 1993-06) Lanzaro, Gregory; Ostrovska, Katherine; Herrero, Marco V.; Lawyer, Phillip G.; Warburg, Alon
The sand fly Lutzomyia longipalpis is the vector of Leishmania donovani chagasi in Latin America. An analysis of genetic variability at 27 enzyme coding loci among three laboratory populations of Lu. longipalpis revealed substantial genetic polymorphism. Levels of genetic distance between all pairwise comparisons of colonies were very high, and consistent with those previously reported among separate species in the genus Lutzomyia. Between 7% and 22% of the loci studied were diagnostic for any two of the colony populations. Experimental hybridization between colonies resulted in the production of sexually sterile male progeny. Our results provide strong evidence that Lu. longipalpis exists in nature as a complex of at least three distinct species. The possible effects of colonization on the genetic makeup of laboratory populations is considered in extending our results to natural populations.
Morphologic abnormalities in Amblyomma mixtum, Amblyomma naponense, Amblyomma cf. oblongoguttatum and Amblyomma tapirellum (Acari: Ixodidae) of Costa Rica.
(Systematic & Applied Acarology Society, 2021-02-20) Domínguez, Lillian G.; Montenegro, Víctor M.; Bermudez, Sergio Eduardo
In this work, we describe abnormalities in adults of Amblyomma mixtum, Amblyomma naponense, Amblyomma cf. oblongoguttatum and Amblyomma tapirellum of Costa Rica. General anomalies manifested as body asymmetry, nanism, and gigantism, while local anomalies occurred in the legs, festoons, anal pore and spiracle. These are the firsts mention of abnormalities in ticks from Costa Rica.
Seasonal variations in testicular consistency, scrotal circumference and spermiogramme parameters of extensively reared Brahman (Bos indicus) bulls in the tropics
(Elsevier, 2002-07) Pérez, E.; Rodríguez-Martínez, H.; Chacón Calderón, Jorge
Twenty-five extensively bred mature Brahman (Bos indicus) breeding bulls were clinically examined and electroejaculated at monthly intervals for 13 months to study whether testicular consistency (TC), scrotal circumference (SC), sperm motility and sperm morphology show seasonal variation under tropical conditions. Changes in SC were positively related to body condition (BC) (beta = 0.7 cm, P < 0.001) and age (P < 0.01). However, these changes were not associated with deviations in TC, sperm motility, or morphology (P > 0.05). Sperm motility was higher in samples collected during the breeding season than in samples collected at other times (62 versus 52%, LSM, P < 0.01). The frequency of folded tails with trapped cytoplasmic droplets fluctuated among monthly ejaculations(LSM range 3-21%, P < 0.05). However, there was no relationship between these fluctuations and environmental temperature, precipitation or changes in BC, TC or SC of the bulls (P > 0.05). Other sperm abnormalities did not change significantly during the study period. The absence of a relationship between any of the climatic variables studied and SC, CT and sperm motility or morphology, respectively, indicates that temperature is not a major factor influencing reproductive performance in Brahman bulls in the tropics. In contrast, the changes found in bc followed by variations in SC suggest that nutrition may be an important factor affecting seasonal variations in male reproductive parameters, especially testicular size, in these sires.
Serological Status for Chlamydophila psittaci, Newcastle Disease Virus, Avian Polyoma Virus, and Pacheco Disease Virus in Scarlet Macaws (Ara macao) Kept in Captivity in Costa Rica
(Blackwell Science, 2002-01-12) Herrera, I.; Khan, S. R.; Kaleta, E. F.; Müller, H.; Dolz, Gaby; Neumann, U.
From 1998 to 1999, a total of 128 blood samples were collected from scarlet macaws (Ara macao), kept in captivity in 11 different aviaries located in six provinces of Costa Rica. The sera were examined for antibodies directed against Chlamydophila psittaci, Newcastle disease virus (NDV), avian polyoma virus (APV), and Pacheco disease virus (PDV). Testing by enzyme-linked immunosorbent assay (ELISA), showed 16 (12.39%) of the samples (n = 129) exhibited antibodies directed against C. psittaci. Employing haemagglutination inhibition tests for NDV antibodies, all of the samples were found to be negative. The prevalence of antibodies specific for APV was tested with a blocking ELISA and serum neutralization tests (SNT) and 12 of 128 samples (9.37%) were found to be positive with both tests. In SNT, two out of 128 samples (1.56%) were positive for PDV. This is the first description of the serological status in scarlet macaws in captivity in Costa Rica. The study demonstrates the absence of NDV antibodies in the birds investigated on one hand, but also indicates a health hazard for numerous avian species due to the risk of infections with C. psittaci, APV or PDV.
Seroprevalence and factors associated with Toxoplasma gondii-, Neospora caninum- and Coxiella burnetii-infections in dairy goat flocks from Costa Rica
(Elsevier, 2018-09-19) Dolz, Gaby; Villagra-Blanco, Rodolfo; Esquivel-Suárez, Andrea; Wagner, Henrik; Romero-Zúñiga, Juan José; Taubert, Anja; Wehrend, Axel; Hermosilla, Carlos
A total of 391 goats from 13 dairy flocks from all Costa Rican regions were analyzed for Toxoplasma gondii-, Neospora caninum- and Coxiella burnetii-related seroprevalence by enzyme-linked immunosorbent assays (ELISA). Additionally, a risk factor analysis for these parasitic infections was performed based on a questionnaire considering several environmental and housing/management factors. A total of 62.1% (243/391) of individual serum samples revealed seropositive for T. gondii, 7.9% (31/391) for N. caninum, and 1.8% (7/391) for C. burnetii. At herd level, the overall seroprevalence for T. gondii was 100%, for N. caninum 69.2% and for C. burnetii 7.7%. However, no clinical signs related to toxoplasmosis, neosporosis or Q fever were apparent in these flocks. T. gondii-related risk factors were the contact with cats (OR=3.44; CI 95%; 2.0–5.91), dogs (OR=5.75; CI 95%; 2.84–11.66), and white-tailed deer (Odocoileus virginianus) (OR=0.15; CI 95%; 0.08–0.26) within or around the farms. The presence of reproductive males in each flock (OR=0.32; CI 95%; 0.14–0.74) and the coexistence of sheep (OR=0.46; CI 95%; 0.2–1.08) and cattle (OR=5.94; CI 95%; 1.70–20.78) revealed as protective and risk factors respectively for N. caninum infections. This study determined for the first time the seroprevalences of N. caninum, T. gondii and C. burnetii in Costa Rican goat flocks. Particularly, the high withinherd seroprevalences determined for T. gondii requires further surveillance to complement these findings.
Spirorchiidiosis (Digenea: Spirorchiidae) and lesions associated with parasites in Caribbean green turtles (Chelonia mydas)
(British Veterinary Association, 2015) Santoro, M.; Rodríguez Ortíz, B.; Morales, Juan Alberto
Forty-seven nesting green turtles (Chelonia mydas) were examined for parasitic pathogens. Four species of cardiovascular flukes (Digenea: Spirorchiidae), Learedius learedi, Hapalotrema postorchis, Monticellius indicum and Amphiorchis solus were collected from 39 of 40 of the turtles, and Neospirorchis species were identified in seven of the 47 by histological examination. The pathological changes associated with the spirorchiids and their eggs included aneurysms, arteritis of great vessels with dark nodular thickenings, endocarditis, haemorrhagic lesions, thrombi, vasculitis, and granulomatous reactions in all the turtles. Ozobranchus branchiatus (Hirudinea: Ozobranchidae) leeches were found on the skin of 27 of the 47 turtles and were associated with traumatic purulent and ulcerative dermatitis. Oesophagitis associated with Rameshwarotrema uterocrescens (Digenea: Pronocephalidae) was recorded in 11 of 43 of the turtles. Petechial haemorrhages and unspecific crater-like ulcerated lesions on the gastric mucosa associated with Charaxicephaloides species and Charaxicephalus robustus (Digenea: Pronocephalidae) were observed in four of 40 of the turtles. Cholycystitis and ectasia of mucosal glands associated with Rhytidodoides similis (Digenea: Rhytidodidae) were observed in one of the 47 turtles. Fibropapillomas were observed on the skin of one turtle and fibromas on the skin of two of them.
Subcutaneous spirocercosis in a dog from Costa Rica and first molecular confirmation of Spirocerca lupi in Central America
(Elsevier, 2022-01-31) Porras-Silesky, Catalina; Fernandez-Trejos, Luis; Villalobos, Randall; Montenegro, Víctor M.; Rojas, Alicia
Spirocerca lupi is the etiological agent of spirocercosis in canids from tropics and subtropics in the world. This parasite can lead to life threatening complications, including the formation of fibro and osteosarcomas. A 5-year- old crossbreed Maltese dog from Costa Rica was presented to a veterinary clinic with two nodules in the sub- cutaneous tissues of the cervical region. One of the nodules resolved with intramuscular antibiotic and anti- inflammatory treatment. However, the other nodule persisted and became purulent. The content of the nodule was excised releasing two coiled 3-cm reddish worms. Identity of the specimens was confirmed by amplifying an 850 bp fragment of the 18S rDNA. The obtained sequence showed 99.96% similarities with S. lupi from Hungary. The present study highlights the need of veterinary clinicians' awareness towards nematode aberrant migrations, and the require of molecular studies to gain insight into the parasite's evolutionary history.
Tail stump sperm defect as a cause of sterility in an indobrasil (Bus indicus) bull
(Blackwell Wissenschafts-Verlag, Berlin, 1998) Rodríguez-Martínez, H.; Chacón Calderón, Jorge
The first known case of an Indobrasil (BOA indicus) bull, with a frequency of 100% of the specific sperm abnormality, known as ‘tail stump sperm defect’ is reported. A 5-year old bull was located as a breeding sire in the dry Pacific zone of the tropical Costa Rica, but no pregnancies were diagnosed after 3 months of natural mating with a group of 60 cows. A breeding sound- ness evaluation showed no major clinical abnormalities at the general sire evaluation and the specific examination of his repm- ductive organs, except for bilateral smaller size of the epi- didymal tails. The collection of three consecutive semen samples by electro-ejaculation, showed sperm akinesia in all of the semen samples, together with the presence of the tail stump sperm defect in all spermatozoa. The clinical findings and mor- phological aspects, including light and scanning electron microscopy of the defect, are presented.
The role of neutrophils in Brucellosis
(American Society for Microbiology, 2020-10-14) BARQUERO-CALVO, ELIAS; Moreno, Edgardo
Brucellosis is a bacterial disease of domestic animals and humans. The pathogenic ability of Brucella organisms relies on their stealthy strategy and their capacity to replicate within host cells and to induce long-lasting infections. Brucella organisms barely induce neutrophil activation and survive within these leukocytes by resisting microbicidal mechanisms. Very few Brucella-infected neutrophils are found in the target organs, except for the bone marrow, early in infection. Still, Brucella induces a mild reactive oxygen species formation and, through its lipopolysaccharide, promotes the premature death of neutrophils, which release chemokines and express “eat me” si nals. This effect drives the phagocytosis of infected neutrophils by mononuclear cells that become thoroughly susceptible to Brucella replication and vehicles for bacterial dispersion. The premature death of the infected neutrophils proceeds without NETosis, necrosis/oncosis, or classical apoptosis morphology. In the absence of neutrophils, the Th1 response exacerbates and promotes bacterial removal, indicating that Brucella-infected neutrophils dampen adaptive immunity. This modulatory effect opens a window for bacterial dispersion in host tissues before adaptive immunity becomes fully activated. However, the hyperactivation of immunity is not without a price, since neutropenic Brucella-infected animals develop cachexia in the early phases of the disease. The delay in the immunological response seems a sine qua non requirement for the development of long-lasting brucellosis. This property may be shared with other pathogenic alphaproteobacteria closely related to Brucella. We propose a model in which Brucella-infected polymorphonuclear neutrophils (PMNs) function as “Trojan horse” vehicles for bacterial dispersal and as modulators of the Th1 adaptive immunity in infection.
Transient exposure to sublethal concentrations of a pesticide mixture (chlorpyrifos–difenoconazole) caused different responses in fish species from different trophic levels of the same community
(Elsevier, 2021) Redondo, Sergei; León, Ana C.; Jiménez, Katherine; Solano, Karla; Blanco-Peña, Kinndle; Mena, Freylan
The assessment of early effects caused in biota by sublethal exposure to pesticide mixtures should enhance the realism in the ecological risk assessment for agricultural landscapes. This study aimed to evaluate sub-individual responses in fish, which can be linked with outcomes at higher levels of biological organization and affect their trophic relationships. A multilevel biomarker approach was applied to assess the effects of a 48 h exposure of two freshwater mesoamerican fish species (Parachromis dovii and Poecilia gillii) to a mixture of sublethal concentra- tions of chlorpyrifos (5 μg/L) and difenoconazole (325 μg/L). Transcriptomic induction of cyp1A and the ac- tivities of 7-ethoxy-resorufin-O-distillase (EROD) and glutathione S-transferase (GST) were measured as biotransformation-related biomarkers; cholinesterase activity (ChE) was assessed as a neurotoxicity biomarker; resting metabolic rate (RMR) was measured as a physiological biomarker; and the movement of fish in a dark–light environment as a behavior biomarker. The exposure to the mixture had evident effects on P. gillii, with significant induction of cyp1A transcription, increased EROD activity, ChE inhibition in muscle, and increased permanence in the light side of the dark–light environment. Meanwhile, P. dovii only showed significant in- duction of cyp1A, without evidence of neurotoxicity or changes in behavior. This study demonstrates that the severity of the effects caused by the exposure to a mixture of pesticides can differ among species from the same trophic chain. The potential impairment of predator-prey relationships is a relevant effect that pesticide pollution can cause and it should be considered for the risk assessment of such contaminants.

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