Activation of murine macrophages by membrane proteins from Tritrichomonas foetus grown on iron- and calcium-rich conditions.

Tritrichomonas foetus is a protozoan parasite that causes a venereal disease in cattle limiting reproduction by abortions and sterility. The immune response against this parasite is poorly understood. Since the iron and calcium ions are important regulators of the microenvironment of the urogenital tract in cattle, we decided to evaluate the role of these divalent cations on the antigenicity of membrane proteins of T. foetus on macrophage activation as one of the first inflammatory responses towards this pathogen. Colorimetric methods and ELISA were used to detect the nitric oxide and oxygen peroxide production and expression of cytokines in culture supernatant from macrophage incubated with membrane proteins from T. foetus cultured in iron- and calcium-rich conditions. qRT-PCR assays were used to evaluate the transcript expression of genes involved in the inflammatory response on the macrophages. The membrane proteins used for in vitro stimulation caused the up-regulation of the iNOS and NOX-2 genes as well as the generation of NO and H2 O2 in murine macrophages on a dependent way of the metal concentrations. Additionally, after stimulation, macrophages showed a considerable rise in pro-inflammatory cytokines and a downregulation of anti-inflammatory cytokines, as well as up-regulation in the transcription of the TLR4 and MyD88 genes. These data suggest that membrane proteins of T. foetus induced by iron and calcium can activate an inflammatory specific macrophage response via TLR4/MyD88 signalling pathway.

Exposure of Tritrichomonas foetus to sublethal doses of metronidazole induces a specific proinflammatory response in murine macrophages.

Tritrichomonas foetus is a flagellated parasite that primarily infects the reproductive tissues of livestock, causing bovine trichomoniasis. The cytoplasmic membrane of T. foetus contains various compounds that contribute to adherence, colonization, and pathogenicity. Metronidazole (MTZ) is the main treatment for trichomoniasis, but the emergence of drug-resistant strains is a concern due to improper use and dosing. T. foetus infection induces inflammation, and macrophages are key players in the immune response. However, our understanding of the host's immune response to T. foetus is limited, and the specific mechanisms underlying these responses are not well understood. This study aimed to investigate the impact of T. foetus surface proteins from trophozoites cultured under different sublethal MTZ conditions (MTZ-treated T. foetus MPs) on macrophage activation. By analyzing cytokine levels and gene expression in murine macrophages, we demonstrated that MTZ-treated T. foetus MPs induce a specific proinflammatory response. MTZ-treated T. foetus MPs-exposed macrophages exhibited a higher NO and H2 O2 production and overexpression of iNOS and NOX-2 genes in comparison to untreated T. foetus. Additionally, MTZ-treated T. foetus MPs triggered a significant induction of the proinflammatory cytokines IL-1ß, IL-6, TNF-α, and IFN-γ, as well as the overexpression of the TLR4, MyD88, and NF-κB genes on murine macrophages. The study aimed to unravel the immunological response and potential proinflammatory pathways involved in T. foetus infection and MTZ stress. Understanding the immune responses and mechanisms through which T. foetus surface proteins activate macrophages can contribute to the development of new therapeutic strategies for controlling bovine trichomoniasis.

Impacto indirecto de COVID-19 en las tasas de incidencia de enfermedades transmitidas por vector en México / Indirect impact of COVID-19 on the incidence rates of vector-borne diseases in Mexico

Resumen Introducción: La distribución espacial y temporal de la infección por SARS-CoV-2 sobrepasa las áreas endémicas de enfermedades transmitidas por vector (ETV), cuya vigilancia en México ha cambiado sustancialmente a partir del primer caso confirmado de COVID-19. Objetivos: Estimar y comparar las tasas de incidencia de las ETV antes y después de la introducción del SARS-CoV-2 en México. Métodos: Estudio retrospectivo de casos de ETV de 2014 a 2021. Las tasas de incidencia de cada ETV en el periodo previo (2014-2019) y posterior (2020-2021) a la introducción del SARS-CoV-2 en México fueron calculadas y comparadas. Resultados: Antes de la introducción del SARS-CoV-2, las tasas de incidencia de las ETV fueron altas y posterior a la introducción del coronavirus hubo un descenso en los índices epidemiológicos; sin embargo, solo se identificó diferencia estadística significativa en la tasa de incidencia de la malaria (p ≤ 0.05) y otras rickettsias (p ≤ 0.05). Conclusiones: Algunas medidas para reducir los casos de COVID-19, como el distanciamiento social, el confinamiento domiciliario, la reducción en el aforo en el transporte público y el trabajo en casa, probablemente contribuyeron a disminuir temporalmente el número de casos de las ETV; sin embargo, puede haber rebrote de las ETV en el futuro cercano.

Abstract Introduction: SARS-CoV-2 infection spatial and temporal distribution overlaps with endemic areas of vector-borne diseases (VBD), whose surveillance in Mexico has substantially changed since the first COVID-19 confirmed case. Objectives: To estimate and compare the incidence rates of VBDs before and after the introduction of SARS-CoV-2 in Mexico. Methods: Retrospective study of VBD cases from 2014 to 2021. The incidence rates of each VBD in the period before (2014-2019) and after (2020-2021) the introduction of SARS-CoV-2 in Mexico were calculated and compared. Results: Before the introduction of SARS-CoV-2, the incidence rates of VBDs were high and after the introduction of coronavirus there was a decrease in epidemiological indices; however, there was only statistically significant difference in the incidence rate of malaria (p ≤ 0.05) and other rickettsiae (p ≤ 0.05). Conclusions: Some measures to reduce COVID-19 cases, such as social distancing, home confinement, reductions in public transport and working at home (home office), probably temporarily decreased the number of VBD cases; however, there may be a resurgence of VBDs in the near future.

Presence of Toxoplasma gondii in Pork Intended for Human Consumption in Tropical Southern Mexico.

BACKGROUND: Toxoplasmosis is caused by the protozoon Toxoplasma gondii, which is one of the most widespread parasites that infect animals and humans worldwide. One of the main routes of infection for humans is through the consumption of infected meat containing bradyzoites in tissue cysts. Pork is one of the foremost meat types associated with outbreaks of acute toxoplasmosis in humans. MATERIALS AND METHODS: Sixty blood samples were collected from finished pigs at slaughter and their sera was evaluated by an indirect-IgG ELISA. Matched muscle samples were obtained from the tongue and loin. Whole blood and tissue samples were evaluated to search for T. gondii DNA using a nested-polymerase chain reaction. RESULTS: Seroprevalence of T. gondii was 96.6% (58/60) of sampled pigs. Meanwhile, T. gondii DNA was present in 23.21% of tongue tissue samples (13/56), 7% of loin tissues (4/57), and 0% in blood samples (0/44), respectively. Two pigs were serologically indeterminate. CONCLUSION: This is the first report of the presence of T. gondii DNA in tissue samples obtained from finalized pigs. Results from the present study suggest a high exposure to T. gondii in pigs intended for human consumption from the tropical region of Mexico. Thus, the consumption of some undercooked pork meat meals typical from the southern region of Mexico could represent a significant risk for acquiring infection for the human population.

Toxoplasmosis i Mexico: epidemiological situation in humans and animals / Toxoplasmosis en México: situación epidemiológica en humanos y animales

Toxoplasmosis is a parasitic disease widely distributed throughout the world, infecting a wide variety of animal species including humans. In Mexico, this parasite has been detected in different parts of the country, particularly in the tropical areas where the parasite can remain infective for long periods of time due to the environmental conditions (i.e. high temperature and humidity over the whole year). Several epidemiological studies have been conducted in both human and animal populations, but despite the wide distribution of the agent in the country, there is a significant lack of knowledge on the parasite transmission, treatment alternatives and control measures. The lack of feral cat populations and control measures in sites of meat production for human consumption are playing a role that has led to the wide spread of the disease in the country, particularly in tropical areas of Southeastern Mexico. For these reasons, this manuscript aims to review the published information on relevant epidemiological aspects of infection with T. gondii in humans and animals from Mexico.

La toxoplasmosis es una enfermedad parasitaria ampliamente distribuida en todo el mundo y puede infectar a una gran diversidad de especies animales y a los humanos. En México, esta parasitosis ha sido detectada en diferentes partes del país, en particular en las zonas tropicales en donde debido a las condiciones ambientales (ej. alta temperatura y humedad a lo largo todo el año), el parásito puede mantenerse infectante por largos períodos de tiempo en el medio ambiente. Se han realizado diversos estudios epidemiológicos tanto en poblaciones humanas como en animales y se observa que a pesar de la amplia distribución y buen establecimiento del agente en el país, existe un importante desconocimiento desde la epidemiologia, tratamientos alternativos o las medidas de control. La falta de control de las poblaciones ferales de felinos así como el establecimiento de medidas de control en unidades de producción de carne de diferentes especies para consumo humano están jugando un papel primordial que ha favorecido la amplia diseminación de la enfermedad en el país, principalmente en las zonas tropicales del sureste mexicano. Por lo que este manuscrito tiene como objetivo revisar la información publicada hasta ahora que nos describe aspectos epidemiológicos relevantes de la infección por T. gondii en humanos y animales de México.

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico

Background The American trypanosomiasis is a zoonosis caused by the protozoaTrypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.Methods A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated.Results The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p<0.05).Conclusions Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases ofT. cruzi cases were found.(AU)

American trypanosomiasis and associated risk factors in owned dogs from the major city of Yucatan, Mexico

Background The American trypanosomiasis is a zoonosis caused by the protozoaTrypanosoma cruzi (T. cruzi). The disease is widely distributed throughout the American continent, affecting a wide range of hosts, including dogs. It is present in the canine population in the State of Yucatan, Mexico. However, no significant studies in owned dogs have been performed in the metropolitan area of Merida. A transversal study was conducted in 370 owned dogs from Merida, Yucatan, Mexico.Methods A cross-sectional study including 370 dogs was performed in a major city of Yucatan, Mexico, to detect IgG antibodies against T. cruzi. A commercial ELISA test kit was used and a chi-square test used to evaluate associated risk factors; odds ratio (OR) and 95 % confidence interval (CI) were also estimated.Results The indirect ELISA and western blot (WB) tests were used to detect specific immunoglobulin G antibodies against T. cruzi in serum samples. A prevalence of 12.2 % was found; age and area of residence were statistically associated with seropositivity in dogs (p 0.05).Conclusions Results from the present study suggests the presence and abundance of the vector in urban conditions where a high number of seropositive cases ofT. cruzi cases were found.

Seroprevalence of feline leukemia virus, feline immunodeficiency virus and heartworm infection among owned cats in tropical Mexico.

Several infectious agents may be distributed within a healthy population of cats where diverse risk factors predispose them to come into contact with pathogens. Blood samples from 227 owned cats in Merida, Mexico, were collected with the objective of determining the seroprevalence and associated risk factors of feline leukemia virus (FeLV) and Dirofilaria immitis antigen, and feline immunodeficiency virus (FIV) antibody. Serological detection of FeLV and D immitis antigens, and FIV antibodies was performed using the commercial kit SNAP Feline Triple Test. The prevalence was found to be 7.5% for FeLV, 2.5% for FIV and 0% for D immitis. Adult cats were at a higher risk of coming into contact with FeLV (P <0.01) than younger cats. Owing to its low prevalence, a risk factor analysis was not performed for FIV. The prevalence of retroviral infections found in this study was low, but within the limits reported in the different geographical areas of the world. Cases of filariosis in the domestic cats of Merida, Mexico, may be absent or very low; however, the low sample size may have influenced these results.

Assessment of the anti-protozoal activity of crude Carica papaya seed extract against Trypanosoma cruzi.

In order to determine the in vivo activity against the protozoan Trypanosoma cruzi, two doses (50 and 75 mg/kg) of a chloroform extract of Carica papaya seeds were evaluated compared with a control group of allopurinol. The activity of a mixture of the three main compounds (oleic, palmitic and stearic acids in a proportion of 45.9% of oleic acid, 24.1% of palmitic and 8.52% of stearic acid previously identified in the crude extract of C. papaya was evaluated at doses of 100, 200 and 300 mg/kg. Both doses of the extracts were orally administered for 28 days. A significant reduction (p < 0.05) in the number of blood trypomastigotes was observed in animals treated with the evaluated doses of the C. papaya extract in comparison with the positive control group (allopurinol 8.5 mg/kg). Parasitemia in animals treated with the fatty acids mixture was also significantly reduced (p < 0.05), compared to negative control animals. These results demonstrate that the fatty acids identified in the seed extracts of C. papaya (from ripe fruit) are able to reduce the number of parasites from both parasite stages, blood trypomastigote and amastigote (intracellular stage).

Importancia de la caracterización de cepas de Trypanosoma cruzi / The importance of the characterisation of Trypanosoma cruzi strains

El trypanosoma cruzi (T. cruzi) es un protozoario hemoflagelado, considerado el agente causal de la enfermedad de Chagas y es transmitido a los hospederos mamíferos por medio de insectos vectores del género Triatoma. El T. cruzi presenta un pleomorfismo natural, al cual se ha atribuido a la diferencia de severidad con que se presenta la enfermedad en el hospedero humano y otros mamíferos. Considerando este aspecto han sido varios los trabajos sobre caracterización de cepas de T. cruzi, abarcando aspectos biológicos, bioquímicos y moleculares para poder establecer un método de clasificación de las diferentes cepas de dicho parásito, de manera que las cepas que pertenezcan a un mismo grupo compartan estos aspectos y así una cepa pudiera ser representativa de ese grupo, simplificando los estudios a realizar. Esta revisión pretende dar un panorama de los diferentes métodos de caracterización de la cepas T. cruzi, para tratar de agruparlas para su mejor estudio y control