RESUMEN
The adverse effects of heat stress (HS) on the welfare and productivity of cattle are the result of the associated hyperthermia and the physiological and behavioral mechanisms performed by the animal to regulate body temperature. The negative effects of HS on in vitro oocyte maturation and in vitro bovine embryo production have been reported; being one of the major concerns due to economic and productive losses, and several mechanisms have been implemented to reduce its impact. These mechanisms include supplementation of the medium with hormones, adjuvants, identification of protective genes, among others. This review aims to explore the cellular and molecular mechanisms of insulin-like growth factor-1 (IGF-1) during in vitro and in vivo maturation of bovine oocytes and its thermoprotective effect under HS. Although the supplementation of the culture medium during oocyte maturation with IGF-1 has been implemented during the last years, there are still controversial results, however, supplementation with low concentration showed a positive effect on maturation and thermoprotection of oocytes exposed to higher temperatures. Additionally, IGF-1 is involved in multiple cellular pathways, and it may regulate cell apoptosis in cases of HS and protect oocyte competence under in vitro conditions.
RESUMEN
BACKGROUND AND AIM: Wildlife animals are reservoirs of a large number of microorganisms pathogenic to humans, and ticks could be responsible for the transmission of these pathogens. Rickettsia spp. are the most prevalent pathogens found in ticks. This study was conducted to detect Rickettsia spp. in ticks collected from free-living and illegally trafficked reptiles from the Department of Córdoba, Colombia. MATERIALS AND METHODS: During the period from October 2011 to July 2014, ticks belonging to the family Ixodidae were collected, preserved in 96% ethanol, identified using taxonomic keys, and pooled (between 1 and 14 ticks) according to sex, stage, host, and collected place for subsequent DNA extraction. Rickettsia detection was performed using real-time polymerase chain reaction (RT-PCR), followed by conventional PCR to amplify a larger fragment of the gltA and 16S rRNA genes. The amplicons were sequenced using the Sanger method, and the nucleotide sequences were subjected to BLAST analysis to identify homologous sequences in GenBank, after which phylogenetic analysis was performed using the MEGA X software. RESULTS: In total, 21 specimens of nine species of reptiles were sampled, from which 805 Amblyomma dissimile ticks were collected, but only 180 ticks were selected to create 34 groups. The DNA of Rickettsia spp. was detected in 30/34 (88%) groups. The sequences of the gene gltA and 16S rRNA revealed a 100% identity with Candidatus Rickettsia colombianensi (GenBank: KF905456 and GenBank: KF691750). CONCLUSION: A. dissimile was the only tick found in all the sampled reptiles. The presence of Candidatus Rickettsia colombianensi in reptile ticks could represent a public health problem due to the risk of transmission to humans and the introduction of microorganisms to other geographical areas.
RESUMEN
Introducción: La vigilancia de las enfermedades transmitidas por vectores es importante para establecer medidas de control en salud pública. Las poblaciones indígenas de Córdoba viven en condiciones geoclimáticas que favorecen la presencia de vectores que podrían permitir la diseminación y aparición de hantavirosis, rickettsiosis y fiebre por el virus Chikungunya. Objetivo: Establecer la seroprevalencia de Hantavirus, Rickettsia sp. y Chikungunya en la población indígena de Tuchín, Córdoba. Materiales y métodos: Se realizó un estudio descriptivo de corte transversal en 190 individuos del resguardo indígena del municipio de Tuchín; el muestreo fue realizado entre agosto y diciembre del 2012. La detección de anticuerpos IgG contra Hantavirus se llevó a cabo con la prueba IgG DxSelectTM (Focus Technologies, EL1600G, California, EE. UU.), anticuerpos IgG contra Rickettsia sp. se determinaron por inmunofluorescencia indirecta y se realizó detección de anticuerpos IgG contra el virus Chikungunya mediante ELISA de captura (Nova-Tec, inmunodiagnostica GmbH, CHIG0590, Alemania). Resultados: De 190 sueros analizados, el 5,2% (10/190) fueron positivos para Rickettsia sp. del grupo de la fiebre manchada, para Hantavirus 7 de 87 (8%) fueron positivos y no se encontraron positivos para Chikungunya. No se encontraron diferencias significativas (p = 0,05) entre los seropositivos de Hantavirus y Rickettsia sp. para las variables género, edad y ocupación. Conclusiones: Los hallazgos demuestran exposición previa a Rickettsia sp. y a Hantavirus en la población indígena de Tuchín. Los resultados pueden ser útiles para establecer una alerta sobre estas fiebres hemorrágicas. Aunque no se hallaron seropositivos para Chikungunya, este fue el primer trabajo de vigilancia epidemiológica realizado en Colombia sobre este virus.
Introduction: Vector-borne disease surveillance is important for establishing control measuresin public health. Indigenous populations of Cordoba live in climate conditions that favor the presence of vectors that might allow the spread and emergence of hantavirus cases, rickettsial and Chikungunya fever. Objective: To establish the prevalence of Hantavirus, Rickettsia sp. and Chikungunya in theindigenous population of Tuchín, Cordoba. Materials and methods: A cross-sectional descriptive study on 190 individuals of the indigenous reservation of the municipality of Tuchín was carried out; the serum samples were collected between August and December of 2012. The following serology tests were performed: antibody IgG against Hantavirus IgG Dx Select TM (Focus Technologies, EL1600G, California, USA); indirect immunofluorescence technique for Rickettsia spotted fever group IgG and ELISA IgG antibodies against Chikungunya virus (Nova-Tec, diagnostic GmbH, CHIG0590, Germany). Results: Out of 190 analyzed sera, 5.2% (10/190) were positive for Rickettsia sp. spotted fever group, Hantavirus 7 of 87 (8.0%) and 0% for Chikungunya. Significant differences among those positive for Hantavirus and Rickettsia sp. for the variables gender, age and occupation were not found. Conclusions: The findings reveal the prevalence of Rickettsia sp. and Hantavirus in the indigenous population of Tuchín. These results are useful to establishing an alert regarding thesehemorrhagic fevers. Although no positive result for Chikungunya virus was found, this is the first epidemiological surveillance study conducted in Colombia on this virus.
