High prevalence of Enterovirus E, Bovine Kobuvirus, and Astrovirus revealed by viral metagenomics in fecal samples from cattle in Central Colombia.

Livestock plays a crucial role in ensuring food security and driving the global economy. However, viral infections can have far-reaching consequences beyond economic productivity, affecting the health of cattle, as well as posing risks to human health and other animals. Identifying viruses present in fecal samples, a primary route of pathogen transmission, is essential for developing effective prevention, control, and surveillance strategies. Viral metagenomic approaches offer a broader perspective and hold great potential for detecting previously unknown viruses or uncovering previously undescribed agents. Ubaté Province is Colombia's dairy capital and a key center for livestock production in the country. Therefore, the purpose of this study was to characterize viral communities in fecal samples from cattle in this region. A total of 42 samples were collected from three municipalities in Ubaté Province, located in central Colombia, using a convenient non-probabilistic sampling method. We utilized metagenomic sequencing with Oxford Nanopore Technologies (ONT), combined with diversity and phylogenetic analysis. The findings revealed a consistent and stable viral composition across the municipalities, primarily comprising members of the Picornaviridae family. At the species level, the most frequent viruses were Enterovirus E (EVE) and Bovine Astrovirus (BoAstV). Significantly, this study reported, for the first time in Colombia, the presence of viruses with veterinary importance occurring at notable frequencies: EVE (59%), Bovine Kobuvirus (BKV) (52%), and BoAstV (19%). Additionally, the study confirmed the existence of Circular replicase-encoding single-stranded (CRESS) Virus in animal feces. These sequences were phylogenetically grouped with samples obtained from Asia and Latin America, underscoring the importance of having adequate representation across the continent. The virome of bovine feces in Ubaté Province is characterized by the predominance of potentially pathogenic viruses such as BoAstV and EVE that have been reported with substantial frequency and quantities. Several of these viruses were identified in Colombia for the first time. This study showcases the utility of using metagenomic sequencing techniques in epidemiological surveillance. It also paves the way for further research on the influence of these agents on bovine health and their frecuency across the country.

Molecular detection and characterization of Giardia spp., Cryptosporidium spp., and Blastocystis in captive wild animals rescued from central Colombia.

Cryptosporidium, Giardia, and Blastocystis are significant causes of diarrhea worldwide. However, studies on their prevalence in wild animals are limited, compared to humans and domestic animals. In this study, we collected 23 stool samples from captive wild rescued animals in Boyacá, Colombia. Using conventional PCR, we detected Cryptosporidium spp., Giardia spp., and Blastocystis in over half of the samples (69.6%). Cryptosporidium spp. (43.5%) were the most commonly found, followed by Giardia spp. (39.1%) and Blastocystis (13.0%). Co-infections involving these parasites were also observed. Subsequent genotyping revealed Cryptosporidium canis and Cryptosporidium ryanae as the predominant species. These findings contribute valuable information about the ecoepidemiology of intestinal parasites in Colombian wild animals.

Seroprevalence and risk factors of bovine fasciolosis in the municipalities of Colombia.

Background and Aim: Bovine fasciolosis is a reemerging neglected disease with a worldwide distribution caused by the trematode Fasciola spp., which parasitize various hosts. Bovine fasciolosis is responsible for large economic losses in the bovine livestock sector. This study aimed to estimate the seroprevalence and risk factors of bovine fasciolosis in the municipalities of Colombia. Materials and Methods: This was a descriptive cross-sectional study with simple random sampling conducted on 1140 cattle from the municipalities of Chiquinquirá, San Miguel de Sema, and Ubaté for a duration of 3 months. Serum samples were processed using the commercial Fasciola hepatica Antibody Test Kit IDEXX® Fasciolosis Verification (IDEXX, United States), which identified immunoglobulin G antibodies for gf2 antigen purified from Fasciola extracts. The f2 antigen is extremely immunogenic and highly specific for F. hepatica. An epidemiological survey was performed to record variables related to the sampled animals and herd management practices. Data were processed using the statistical program Epi Info® (Centers for Disease Control and Prevention; Atlanta, Georgia). The prevalence ratio was estimated to evaluate the association between fasciolosis and the hypothesized causal factors and the significance of this association using Pearson's Chi-square test. Finally, a logistic regression model was developed. Results: The overall seroprevalence was 72.3%. The seroprevalence was 83.9% (323/385) in Chiquinquirá, 68.17% (257/377) in Ubaté, and 64.55% (244/378) in San Miguel de Sema. The seroprevalence was higher in male animals in Chiquinquirá and in female animals in San Miguel de Sema and Ubaté. Similarly, sex showed a statistically significant association with disease prevalence in Ubaté. The highest prevalence was found in cattle aged >2 years. The Holstein breed showed maximum seroprevalence in Chiquinquirá (p ≤ 0.05) and San Miguel de Sema, whereas crossbreed showed higher seroprevalence in Ubaté. Similarly, in Chiquinquirá, the association between the seroprevalence of fasciolosis and the presence of other species was statistically significant (95% confidence interval [CI]: 0.9601-3.4944; p = 0.0448). In Ubaté, the disease presentation was also associated with pasture rental (95% CI: 0.4047-1.0023; p = 0.003) and attendance to livestock expositions (95% CI: 0.2313-1.0636; p = 0.044). However, in San Miguel de Sema, water from the stream showed a statistically significant association with disease presentation (95% CI: 0.5209-1.0985; p = 0.00649785). Female sex and diarrhea occurrence were considered risk factors for fasciolosis. Conclusion: A high seroprevalence of antibodies to Fasciola spp. was detected in cattle in the study municipalities, indicating a high parasite distribution in these areas. Female sex and diarrhea were established as risk factors associated with fasciolosis in Ubaté and San Miguel de Sema, respectively. Further, research is necessary to establish prevention and control programs against parasitosis.

Molecular characterization of Fasciola hepatica in endemic regions of Colombia.

Fasciola hepatica is a zoonotic trematode that affects a wide range of hosts, including cattle, sheep, and goats. The economic impact of the parasite on the cattle industry is significant, with high losses reported worldwide. While its impact on human health was previously underestimated, recent years have seen a rise in fascioliasis cases, leading to increased interest among researchers globally. To characterize the genetic diversity and intraspecific variation of this parasite in South America, specifically in Colombia, we collected 105 adult parasites from cattle bile ducts in seven Colombian departments (Antioquia, Boyacá, Santander, Cauca, Cundinamarca, Nariño, Norte de Santander, and Santander) to assess the parasite's phenotypic analyses, genetic diversity, and population structure. A computer image analysis system (CIAS) was applied based on standardized morphological measurements. Liver-fluke size was studied by principal component analysis (PCA). DNA sequences were obtained for nuclear markers such as the 28S, ß-tubulin 3, ITS1, ITS2, and the mitochondrial marker Cytochrome Oxidase I (COI). Multiple statistical tests were performed, and the parasite's population structure was analyzed. Maximum Likelihood (ML) phylogenetic reconstructions were carried out using the sequences obtained herein and sequences available in GenBank. Morphological results revealed that all the obtained individuals matched F. hepatica's morphology. There was no evidence of high genetic diversity, and the absence of genetic structure at the country-level was notable, possibly caused by a demographic expansion of this trematode in Colombia or the low resolution of the molecular markers employed. Future studies are still needed to unveil the genetic population structure of F. hepatica across the country.

Seroprevalence and risk factors associated with bovine herpesvirus 1 in dairy herds of Colombia.

Background and Aim: Infectious bovine rhinotracheitis (IBR) is an infectious disease widely distributed globally and is considered the main cause of various reproductive and respiratory tract diseases in cattle and buffaloes. This study aimed to estimate seroprevalence and determine risk factors associated with the presentation of IBR in the municipality of Sotaquirá, Boyacá (Colombia). Materials and Methods: A descriptive cross-sectional study with simple random sampling was performed, and the sample size was 1,000 cattle. Blood samples were obtained by coccygeal venipuncture and processed through indirect enzyme-linked immunosorbent assay using the Synbiotics® kit (Zoetis, New Jersey, USA) with a sensitivity and specificity of 96% and 98%, respectively. Data were processed using the statistical program EpiInfo® (Centers for Disease Control and Prevention; Atlanta, Georgia). Results: A high seroprevalence of 57.5% was established. Seroprevalence was the highest in cattle >4 years of age (65.0% apparent seroprevalence [AS]; 67% true seroprevalence [TS]) and in the Holstein breed (65.5% AS; 67.8% TS). The breed and age of the animals were significantly associated with each other. The Holstein breed, age group >4 years, uncertified semen, and fetal death were established as risk factors for IBR. In comparison, the age groups of <1 and 1-2 years and the Normande breed were established as protective factors against the bovine herpesvirus-1 virus. Conclusion: Management factors, such as livestock from other owners and animal purchases, which affect disease presentation, are evident. The implementation and development of novel prevention and control measures for IBR at the national level are necessary.

Serodiagnosis and Risk Factors Associated with Infectious Agents of Reproductive Diseases in Bovines of Chiquinquirá, District of Boyacá (Colombia).

The productivity of cattle farms is affected by infectious and noninfectious factors that generate economic losses and cause reproductive failure represented by low conception rates, embryonic mortality, abortions, and fetal mummification. The infectious agents that most impact the reproductive health of the bovine species from conception to birth are bovine herpesvirus type 1 (BoHV-1) causing infectious bovine rhinotracheitis (IBR), bovine viral diarrhea virus (BVDV), bovine parainfluenza virus type 3 (PI3), Neospora caninum and Leptospira spp. The objective of this study was to diagnose the presence of BoHV-1, bovine viral diarrhea (BVD), PI3, Neospora caninum, and Leptospira spp. by serology and identify the risk factors associated with infectious agents of reproductive interest in bovines of Boyacá (Colombia). A descriptive cross-sectional study was developed, with simple random sampling, where a sample size of 601 female cattle of Holstein, Jersey, and Normande breeds of different age groups was determined. Blood samples were taken and processed using the indirect ELISA technique (SYNBIOTICS®, SERELISA® BVD p80 Ab Mono Blocking, Ingezim R.12.NC.K, PRIMACHECK VPI-3®) and the MAT test for the diagnosis of bovine leptospirosis. The data were processed with the statistical program Epi Info™. The highest apparent seroprevalence was established for infectious bovine rhinotracheitis (61.1%), followed by BVD (37.6%), PI3 (40.9%), neosporosis (51.1%), and leptospirosis (14.8%). Variables such as age >4 years and Holstein breed for IBR and >4 years for BVD were established risk factors. Considering our results, we suggest implementing prevention and control plans that include vaccination as a prophylactic measure and biosecurity tools that reduce the probability of contagion and transmission of pathogens.

Seroprevalence and risk factors associated with the presence of bovine leptospirosis in the municipality of Sotaquirá, Colombia.

Background: Bovine leptospirosis is a zoonotic, infectious, and cosmopolitan disease of worldwide distribution, caused by the spirochete Leptospira spp., which has been diagnosed in humans; domestic mammals, such as dogs, sheep, goats, swine, horses and cattle; and wild animals. It is considered a significant cause of economic losses in livestock because it causes infertility, abortion and reduced milk production. Aim: To establish the prevalence and the main risk factors associated with Leptospira spp. in cattle in the municipality of Sotaquirá, Colombia. Methods: An observational, descriptive, cross-sectional study with simple random sampling was carried out. 1,000 cattle of Ayrshire, Holstein, Jersey, Normande, Zebu, and crossbreeds were sampled. Blood samples were taken by coccygeal venipuncture and processed by microscopic agglutination technique; animals were considered positive when titers were ≥1:100. The data obtained were processed with the statistical program EpiInfo®. Results: A general apparent prevalence (AP) of 16% (160/1,000) was established, where the crossbreeds (20.5% AP), the 2-4 years age group (17% AP), and the serovars Leptospira interrogans serogroup Pomona (5.1%) and L. interrogans serogroup Sjroe serovar Hardjo (3.4%) presented the highest seropositivity. The variables barnyard, artificial insemination, and use of certified semen were identified as protective factors against the disease, while diarrhea was considered a risk factor. Conclusion: The prevalence in this study is within the range of those reported at the national level; however, it is essential to establish plans to control and prevent the disease.

Determinación de anticuerpos antidiarrea viral bovina (DVB) en vacas lecheras de un municipio de Boyacá (Colombia) / Determination of Antibodies against Bovine Viral Diarrhea (BVD) in Diry Cows in a Municipality of Boyacá (Colombia)

Resumen La diarrea viral bovina (DVB) es una patología infecciosa generada por un pestivirus de distribución mundial, causante de problemas reproductivos y pérdidas económicas. El objetivo del presente estudio fue establecer la positividad al virus de diarrea viral bovina (vDVB) en vacas del municipio de Tuta (Boyacá, Colombia), y analizar los grupos etarios, raciales y las variables reproductivas y de manejo como posibles factores de riesgo. Se tomaron 374 muestras de sangre, a las cuales se les realizó la prueba ELISA indirecta, implementando el kit Serelisa® BVD p80 Ab Mono Blocking; los datos se procesaron con EpiInfo®. Se encontró una seroprevalencia del 41,7 %. Los cruces raciales y los bovinos >4 años presentaron la seroprevalencia más alta. Los animales >4 años (p= 0,0000001922) presentaron asociación estadística con la presencia de la enfermedad, y se consideró factor de riesgo para vDVB. Se deben establecer programas de control y prevención que dificulten su diseminación en la zona.

Abstract Bovine viral diarrhea (BVD) is an infectious pathology generated by a pestivirus of worldwide distribution, which causes reproductive problems and economic losses. The objective of this study was to establish bovine viral diarrhea virus (BVDV) positivity in cows from the municipality of Tuta (Boyacá, Colombia), and to analyze age and racial groups and reproductive and management variables as possible risk factors. A total of 374 blood samples were taken and the indirect ELISA test was performed using the Serelisa® BVD p80 Ab Mono Blocking kit; the data were processed with EpiInfo®. A seroprevalence of 41.7% was found. Crossbreds and cattle >4 years had the highest seroprevalence. Animals >4 years old (p= 0.0000001922) were statistically associated with the presence of the disease and were considered a risk factor for BVDV. Control and prevention programs should be established to hinder its dissemination in the area.

Seropositivity and risk factors associated with the presentation of bovine leukosis virus in Sotaquirá, Colombia.

BACKGROUND AND AIM: Enzootic bovine leukosis is a disease economically important to the dairy farming industry worldwide. The virus is of the Deltaretrovirus genus and is primarily transmitted iatrogenically. Most bovines infected with the virus remain asymptomatic with only 5-10% of cattle having lymphomas. This study aimed to determine the seroprevalence of bovine leukosis virus (BLV) in Sotaquirá, Boyacá, Colombia. MATERIALS AND METHODS: We conducted a descriptive, observational epidemiological cross-sectional study using the simple random sampling method with a sample size of 1000. Blood samples from random bovine were processed using the SERELISA® BLV Ab Mono Blocking indirect enzyme-linked immunosorbent assay kit (Zoetis, USA). The assay had a sensitivity of 97% and a specificity of 98%. The collected data were processed using Epi Info® (Centers for Disease Control and Prevention; Atlanta, Georgia). From the study, we could determine a high seroprevalence of BLV in Sotaquirá. RESULTS: We established a high seroprevalence on BLV in the municipality, with 31.1% apparent seroprevalence and 30.6% real seroprevalence rate. We found that male cattle more than 4 years old (39.4%) and the Ayrshire breed (45.5%) had the highest prevalence rates of the virus. In this study, we could establish statistically significant associations according to breed, age, and gender of the cattle under study. Moreover, we identified the risk factors for BLV infection. We found that in cattle aged <1 year and those older than 4 years of age and those of the Holstein breed, the presentation of infectious bovine rhinotracheitis, mucosal secretions, mastitis, fetal death, the presence of a corral, and the implementation of artificial insemination practices were risk factors for BLV infection. CONCLUSION: Determining the prevalence of BLV within the herd and identifying the associated risk factors for the disease are fundamental in developing efficient programs for the control and eradication of BLV within herds.

Identification of Multiple Blastocystis Subtypes in Domestic Animals From Colombia Using Amplicon-Based Next Generation Sequencing.

Blastocystis is frequently reported in fecal samples from animals and humans worldwide, and a variety of subtypes (STs) have been observed in wild and domestic animals. In Colombia, few studies have focused on the transmission dynamics and epidemiological importance of Blastocystis in animals. In this study, we characterized the frequency and subtypes of Blastocystis in fecal samples of domestic animals including pigs, minipigs, cows, dogs, horses, goats, sheep, and llama from three departments of Colombia. Of the 118 fecal samples included in this study 81.4% (n = 96) were positive for Blastocystis using a PCR that amplifies a fragment of the small subunit ribosomal RNA (SSU rRNA) gene. PCR positive samples were sequenced by next generation amplicon sequencing (NGS) to determine subtypes. Eleven subtypes were detected, ten previously reported, ST5 (50.7%), ST10 (47.8%), ST25 (34.3%), ST26 (29.8%), ST21 (22.4%), ST23 (22.4%), ST1 (17.9%), ST14 (16.4%), ST24 (14.9%), ST3 (7.5%), and a novel subtype, named ST32 (3.0%). Mixed infection and/or intra -subtype variations were identified in most of the samples. Novel ST32 was observed in two samples from a goat and a cow. To support novel subtype designation, a MinION based sequencing strategy was used to generate the full-length of the SSU rRNA gene. Comparison of full-length nucleotide sequences with those from current valid subtypes supported the designation of ST32. This is the first study in Colombia using NGS to molecularly characterize subtypes of Blastocystis in farm animals. A great diversity of subtypes was observed in domestic animals including subtypes previously identified in humans. Additionally, subtype overlap between the different hosts examined in this study were observed. These findings highlight the presence of Blastocystis subtypes with zoonotic potential in farm animals indicating that farm animals could play a role in transmission to humans.

Seroprevalence of bovine viral diarrhea virus (BVDV) in cattle from Sotaquirá, Colombia.

Worldwide distributed Bovine Viral Diarrhea Virus (BVDV) represents a high risk of infection in most bovine farms, in which it is associated with gastrointestinal, respiratory, and reproductive diseases. The purpose of this research was to establish the seroprevalence and the main risk factors associated with the presentation of BVDV in the municipality of Sotaquirá, Colombia. Samples were taken from 1000 cattle of Holstein, Ayrshire, Jersey, Normande Gyr and Holstein x Gyr. Epidemiological surveys were implemented, reproductive and management variables were taken into consideration. Indirect ELISA was performed to detect specific antibodies against BVDV using the commercial kit SERELISA® BVD p80 Ab Mono Blocking. The overall seroprevalence of antibodies against BVDV was 42.5% (425/1000), where the Gyr breed (59.1% apparent prevalence (AP); 60.3% real prevalence (PR)) and the age group > 4 years (53.0% PA; 54.4% PR) presented the highest seroprevalences. A significant statistical association was found for the breed, age, management practices evaluated and the presentation of PI3 (p ≤ 0.05). Age group > 4 years, Normande breed, presentation of PI3 and grazing lease were established as risk factors associated with BVDV in the herds. These infections are mainly associated with dairy cattle and herds with many animals, so it is important to consider vaccination plans as a preventive system and follow up on the most common diseases.

Describing the intestinal microbiota of Holstein Fasciola-positive and -negative cattle from a hyperendemic area of fascioliasis in central Colombia.

The ability to identify compositional changes in the intestinal microbiota of parasitized hosts is important for understanding the physiological processes that may affect animal productivity. Within the field of host-parasite interactions, many studies have suggested that helminths can influence the microbial composition of their hosts via their immunomodulatory effects. Bovine fascioliasis is a helminthiasis widely studied by immunologists, but with little information available regarding gut microbial communities. Thus, we aimed to describe the composition of the intestinal microbiota of Holstein Fasciola-positive and -negative cattle using parasitological methods and ELISA (enzyme-linked immunosorbent assay). Bovine fecal samples (n = 65) were obtained from livestock slaughter plants in the Cundi-Boyacense Colombian highlands (a hyperendemic region for bovine fascioliasis) and studied by amplicon-based next-generation 16S-rRNA and 18S-rRNA gene sequencing. From these samples, 35 were Fasciola hepatica-negative and, 30 were F. hepatica-positive in our detection analysis. Our results showed a reduction in the relative abundance of Bacteroidetes and Ascomycota in the Fasciola-positive samples, along with decreased relative abundances of the commensal taxa previously associated with fermentation and digestion processes. However, metabolomic approaches and functional analyzes of the intestinal microbiota are necessary to support these hypothesis. These findings are a small first step in the development of research aimed at understanding how microbial populations in bovines are modulated in liver helminth infections.

Serodiagnóstico de Paratuberculosis en bovinos del municipio de Sogamoso, Boyacá (Colombia) / Serodiagnosis of Paratuberculosis in cattle of the municipality of Sogamoso, Boyacá (Colombia) / Serodiagnóstico da paratuberculose no gado do municipio de Sogamoso, Boyacá (Colômbia)

RESUMEN La Paratuberculosis Bovina (PTB) o Enfermedad de Johne, es una infección del tracto gastrointestinal causada por Mycobacterium avium, subespecie paratuberculosis (Map), que se caracteriza por generar enteritis granulomatosa crónica y linfadenitis en rumiantes. La preocupación más relevante en relación con la importancia de la PTB es su posible vínculo con la Enfermedad de Crohn (EC) en humanos, sin embargo, esta asociación aún está bajo investigación. Se determinó la seroprevalencia de PTB en el municipio de Sogamoso (Boyacá), donde se recolectaron 604 muestras de sangre, cuyo suero fue procesado mediante la técnica de ELISA indirecta con el kit comercial PARACHEK® 2 KIT (Prionics, Suiza). La seroprevalencia fue de 10,9% (66/604), donde el grupo etario de 2 a 3 años y la raza Jersey fueron los de mayor seroprevalencia. Se encontró asociación estadística significativa (p≤0,05) entre la edad de los individuos evaluados y el suministro de concentrado. La seroprevalencia encontrada indica que se está produciendo una transmisión activa de la enfermedad y que las medidas de control disponibles no están siendo llevadas a cabo o no son lo suficientemente efectivas.

ABSTRACT Bovine Paratuberculosis (BPT), or Johne's Disease, is an infection of the gastrointestinal tract caused by Mycobacterium avium, subspecies paratuberculosis (Map), which is characterized by chronic granulomatous enteritis and lymphadenitis in ruminants. The most relevant concern regarding the importance of BPT is its possible link to Crohn's disease (CD) in humans, however this association is still under investigation. The seroprevalence of BPT was determined in the municipality of Sogamoso (Boyacá), where 604 blood samples were collected, their serum was processed by the indirect ELISA technique with the commercial PARACHEK® 2 KIT (Prionics, Switzerland), following the manufacturer's instructions. The seroprevalence was 10,9% (66/604), with the 2 to 3 years age group and the Jersey breed having the highest seroprevalence. A significant statistical association was found (p≤0,05) with the age of the individuals tested and the supply of concentrate. The seroprevalence found indicates that active transmission of the disease is taking place, and that the available control measures are not being carried out or are not effective enough.

RESUMO A Paratuberculose Bovina (PTB) ou Doença de Johne é uma infecção do trato gastrointestinal causada pela Mycobacterium avium subespécie paratuberculosis (Map), caracterizada por gerar enterite granulomatosa crónica e linfadenite em ruminantes. A preocupação mais relevante em relação à importância do PTB é seu possível vínculo com a Doença de Crohn (DC) em seres humanos, no entanto, essa associação ainda está sob investigação. A soroprevalência do PTB foi determinada no município de Sogamoso (Boyacá), onde foram coletadas 604 amostras de sangue, cujo soro foi processado pela técnica ELISA indireta com o kit comercial PARACHEK® 2 KIT (Prionics, Suíça). A soroprevalência foi de 10,9% (66/604), onde a faixa etária de 2 a 3 anos e a raça Jersey foram as que apresentaram maior soroprevalência. Foi encontrada associação estatisticamente significante (p≤0,05) com a idade dos indivíduos avaliados e o suprimento de concentrado. A soroprevalência encontrada indica que a transmissão ativa da doença está ocorrendo e que as medidas de controle disponíveis não estão sendo realizadas ou não são eficazes o suficiente.

Resistencia in vitro de la garrapata Rhipicephalus microplus a organofosforados, piretroides y amitraz en el Departamento de Boyacá, Colombia / In vitro Resistance of Rhipicephalus microplus ticks to Organophosphates, Pyrethroids and Amitraz in Boyacá Department, Colombia

El presente estudio evaluó la resistencia in vitro de la garrapata Rhipicephalus microplus a organofosforados (OF), piretroides sintéticos (PS) y amitraz (AM). Las garrapatas adultas fueron recolectadas en Boyacá, Colombia y sometidas a la prueba de inmersión para evaluar la eficacia de los fármacos, el efecto sobre la ovoposición y el porcentaje de eclosión larvaria. Se utilizó un diseño experimental completamente al azar con cinco grupos y tres repeticiones por tratamiento, con 10 garrapatas por repetición. Los resultados demostraron tasas de mortalidad a las moléculas evaluadas, encontrando 43, 56, 60 y 96% de mortalidad para el grupo control, PS, AM y OF, respectivamente, al día 21 del experimento. La inhibición de la ovoposición fue de 13,4% para el grupo control, 44,6% para AM, 45,5% para PS y 96% para OF. El porcentaje de eclosión de huevos fue de 88% para el grupo control, 16% para AM, 14% para PS y 4% para OF. El presente estudio in vitro representa el primer diagnóstico en el departamento de Boyacá, Colombia.

The present investigation evaluated the in vitro resistance of the Rhipicephalus microplus tick, to organophosphates (OP), synthetic pyretroids (SP), and amitraz. Adult ticks were collected in the Department of Boyacá, Colombia, and subjected to the immersion test, to assess the efficacy of drugs, their effect on oviposition, and the percentage of larvae eclosion. A completely randomized experimental design was used, with 5 groups and 3 replicates per group, with 10 ticks per replicate. The results showed that the mortality rates in terms of percentage (%) of the assessed molecules were: 43 for the control group; 56 for SP; 60 for AM, and 96 for OP, respectively, at day 21 of the study. The inhibition of oviposition was: 13.4% for the control group; 44.6% for AM; 45.5% for SP; and 96% for OP. The present in vitro study represents the first diagnostic of resistance in the Department of Boyacá, Colombia.

Evaluación de la eficacia de la CEPA MAF1309® de Metarhizium anisopliae en el control biológico de garrapatas adultas de Rhipicephalus microplus en Tunja, Colombia / Evaluation of efficacy of MaF1309® strain of Metarhizium anisopliae in biological control of adult ticks Rhipicephalus microplus in Tunja, Colombia

La garrapata del ganado Rhipicephalus microplus constituye el ectoparásito de mayor importancia en las ganaderías de regiones tropicales y subtropicales, al producir pérdidas directas por reducción de la producción de carne, leche y deterioro de las pieles así como a la transmisión de agentes patógenos para el ganado bovino tales como Babesia bovis, Babesia bigemina y Anaplasma marginale. El tratamiento químico ha sido efectivo para el control de las garrapatas; sin embargo,  su uso excesivo ha propiciado la selección de individuos resistentes y por tal motivo, se hace necesario el desarrollo de nuevas alternativas de control, tales como el uso de hongos entomopatógenos. El objetivo del presente estudio fue evaluar la eficacia in vitro de M. anisopliae para el control de la fase adulta de R. microplus, en Tunja, Colombia. Se usó la prueba de inmersión de adultas para evaluar la eficacia de la cepa MaF1309® de M. anisopliae a las siguientes concentraciones: 1x10(4), 1x10(6) y 1x10(8) conidias/mL. Se observó que en las garrapatas tratadas a una concentración de 1x10(8) conidias/mL se alcanzó el 100% de mortalidad a los 14 d postratamiento (PT), mientras que las concentraciones 1x10(6) y 1x10(4) conidias/mL alcanzaron el 100% de mortalidad a los días 16 y 20 PT, respectivamente. La mortalidad fue directamente proporcional a la concentración empleada del hongo, siendo las garrapatas tratadas con concentraciones mayores aquellas que alcanzaron una mortalidad en menor tiempo. Estos resultados in vitro son considerados el inicio de información de tipo local proyectados al diseño de programas de control para el departamento de Boyacá.

The livestock tick Rhipicephalus microplus is a high importance ectoparasite in cattle raised at tropical and sub-tropical regions producing direct losses since reduce meat and milk production and cause leather injury besides transmission of pathogenic agents such as Babesia bovis, Babesia bigemina y Anaplasma marginale. The chemical treatment has been effective to control tick  however the excessive use has selected resistant individuals; for that reason is important to develop new alternatives such as entomopathogen fungi to keep controlled those individuals. The objective of this research was to evaluate in vitro efficacy of M. anisopliae to control adult stage of R. microplus in Tunja, Colombia. The immersion test was used to evaluate efficacy of MaF1309® strain of M. anisopliae at concentrations of 1x10(4), 1x10(6) y 1x10(8) conidia/mL. The group of ticks treated with 1x10(8) conidia had 100% of mortality 14 post-treatment days (PT), otherwise 1x10(6) y 1x10(4) conidia/mL concentrations have 100% of mortality at 16 and 20 PT days, respectively. Mortality was directly proportional to fungus concentration used, the ticks treated with high concentrations reach high mortality in less time. Those in vitro results start in local information projected to design control programs for the department of Boyacá.

Estimación de los Valores de Hematocrito y Hemoglobina en Presencia de Haemonchus sp. en Ovinos de Oicatá, Colombia / Estimation of Hematocrit Packed Cell Volume and Hemoglobin with the Presence of Haemonchus sp. in Sheep of Oicatá, Colombia

La hemoncosis causada por el nemátodo del abomaso de rumiantes, Haemonchus contortus, representa uno de los mayores problemas en los sistemas ovinos debido a su impacto sobre la producción y el costo de los tratamientos. El objetivo del presente estudio fue determinar la prevalencia de Haemonchus sp. y la estimación de los valores de hematocrito (Hto) y hemoglobina (Hb) en ovinos pertenecientes al municipio de Oicatá, Colombia. Se realizó un muestreo aleatorio de 201 animales criollos que pertenecían a explotaciones extensivas. Se tomaron muestras de materia fecal que fueron analizadas por medio del método de concentración formol-éter y posteriormente se realizó la identificación de Haemonchus sp. En los mismos individuos se obtuvo una muestra de sangre de la vena cefálica, se estimaron y se realizaron hemogramas completos. Se escogieron cuatro parámetros hematológicos: hemoglobina (Hb), hematocrito (Hto), recuento de glóbulos rojos (RBC) y volumen corpuscular medio (VCM). Se observó una prevalencia de Haemonchus sp. del 31,3%. Solo el 6% de los animales mostró Hto por debajo de los valores normales, mientras que el 6,5% tenía valores de Hb anormal en presencia del helminto. Los valores de RBC y VCM no demostraron alteraciones en presencia de la infección. No se observó ninguna relación entre los parámetros hemáticos y la presencia de huevos de Haemonchus sp. en las heces ovinas.

Haemonchosis caused by the abomasal nematode of ruminants, Haemonchus contortus, represents one of the biggest problems in sheep farming by its impact on production losses and cost of anthelmintic treatments. The aim of the present study was to determine the prevalence of Haemonchus sp. and the estimated values of the hematocrit (Hto) and hemoglobin (Hb) of sheep from the municipality of Oicatá, Colombia. A random sampling of 201 creole animals belonging to extensive farms was carried out. Individual fecal samples were analyzed by the method of concentration formol-ether and the Haemonchus sp. infection determined. Blood samples from the same animals were obtained from the cephalic vein in EDTA containing tubes. Four hematological parameters were estimated: haemoglobin (Hb), haematocrit (Hto), red blood cells count (RBC) and mean corpuscular volume (MCV). Results were analyzed with the statistical package SPSS18 with a level of statistical significance of p<0.05. A prevalence of 31.3% was found for Haemonchus sp. Only 6% of the animals showed Hto below normal values, while 6.5% had abnormal Hb values in the presence of the helminth. RBC presented normal values in the presence of the parasite. In this study no correlation was found between the presence of the parasite and the haematological parameters determined.