The mycobacterial immunodominant ESAT-6 and CFP-10 antigens are strongly recognizable in tuberculosis-infected cattle, and they do not elicit a response in cattle without infection. In addition, they are absent in most environmental mycobacterial species, and therefore, their use can be an alternative to purified protein derivative (PPD) tuberculin in the development of a more specific skin diagnostic test in cattle. The aim of the current study was to assess the potential of an ESAT-6 and CFP-10 (E6-C10) protein cocktail in a skin test format in naturally tuberculosis-infected and paratuberculosis-infected cattle. We also included MPB83 as a third component in one of the protein cocktail preparations. The protein cocktail was tested at different dose concentrations (5, 10, and 15 μg per protein). The best skin response to the E6-C10 protein cocktail was obtained with 10 μg. Subsequently, this concentration was tested in 2 herds with high and low bovine tuberculosis prevalence, the latter with paratuberculosis coinfection. Our data show that the E6-C10 cocktail allows identification of an important proportion of animals that PPDB is not able to recognize, especially in low-prevalence herds. The protein cocktail did not induce reactions in tuberculosis-free cattle or in paratuberculosis-infected cattle. Addition of MPB83 to the protein cocktail did not make any difference in the skin reaction.

The purpose of this study was to identify relationships between spoligotypes of M. bovis from cattle in Mexico and those reported in countries with free trade of cattle with Mexico: Australia, Canada, New Zealand and the United States of America. Mexican spoligotypes were obtained from isolates collected from cattle in different parts of the country. Spoligotypes from Canada and New Zealand were obtained from different reports in the literature. Those from the United States were obtained from the database of the National Veterinary Services Laboratory in APHIS-USDA. In order to perform the analysis in a single data set, spoligotypes were all converted to binary data and classified according to www.mbovis.org or www.pasteur-guadeloupe.fr:8081. Epidemiologic information included country and species infected. From 3,198 isolates, 174 different spoligotypes were obtained, 95 were orphans. Ninety one percent of the isolates came from the Unites States (n = 1,609) and Mexico (n = 1,323). Spoligotype SB0265 is shared between Canada and the United States in cattle and wildlife. Six spoligotypes, SB0673, SB0121, SB0145, SB0971, SB0140 and SB1165, were frequent in cattle and wildlife in the United States and cattle in Mexico, suggesting wide exchange of strains. Spoligotype SB0669 was found only in Mexico. Spoligotype SB0140 was the most common in Australia and the sixth in the United States and Mexico. In a phylogenetic analysis, spoligotype SB0140 appears as the oldest spoligotype in the data set, suggesting this as the ancestral spoligotype for all spoligotypes in the five countries. Some spoligotypes are shared by animals and humans, corroborating the zoonotic importance of M. bovis.

La acumulación de gases de efecto invernadero en la atmosfera terrestre está ocasionando un cambio climático sin precedentes con graves implicaciones como, fenómenos meteorológicos extremos, cambios en la función y composición de los ecosistemas con la subsecuente diseminación o incremento de prevalencia de distintas enfermedades que afectan al hombre y a los animales. Debido a su importancia resulta relevante analizar el impacto del cambio climático en los sistemas de producción pecuarios, si se analiza la producción agropecuaria como un sistema en el que confluye lo social, ambiental y económico, los efectos del mismo tendrán un impacto directo en la organización social de las unidades de producción, en la seguridad alimentaria y en la salud animal/humana. Un área que requiere especial atención es precisamente la salud animal, la emergencia y reemergencia de enfermedades vectoriales en numerosas regiones del planeta constituye un claro ejemplo de asociación entre cambio climático y efectos sobre la interfaz de la salud humana/animal, las afectaciones a la salud animal pueden obedecer a múltiples factores sociales y medioambientales provocando las llamadas “enfermedades de la producción”, estos factores influencian la aparición de enfermedades emergentes, sin embargo, cada región y cada sistema de producción tiene sus propias vulnerabilidades, estos aspectos deben tomarse en cuenta para diseñar mapas de riesgos locales y regionales; así como diseñar, instrumentar y socializar eficientemente procesos de manejo de riesgos ante enfermedades.

Virulence, is referred as the ability of a pathogen to cause disease, and for mycobacteria it depends on their ability to reside within host cells and evade the microbicidal mechanisms of macrophages. The outcome of tuberculosis (TB) infection is highly variable and it seems that the closest relationship between the Mycobacterium genre and humans has shaped the mycobacterial genome to encode bacterial factors that reflects a highly evolved and coordinated program of immune evasion strategies that interfere with both innate and adaptive immunity causing disease even in fully immunocompetent host. Although Mycobacterium tuberculosis (MTB) does not have classical virulence factors, it has described many virulence-associated genes and virulence lifestyle genes from Mycobacterium tuberculosis complex (MTBC). In this chapter, we describe the most important gene/molecule involved in the host defense modulation response, also the plethora of strategies to evade immune mechanisms of macrophage. We review the main genes whose inactivation in the mycobacterial genome leads to a measurable loss in virulence in the different validated TB models.

Mycobacterium bovis has a wide range of hosts. Usually, it affects cattle; however, it has been detected in humans and many wildlife reservoirs such as cervids, badgers, feral pigs, brushtail possums, and buffaloes. Persistence in wildlife has made it difficult to eradicate M. bovis, even in developed countries. The main route of M. bovis transmission is by aerosol through the respiratory tract; direct contact between cattle and wildlife is the explanation for transmission between species. However, depopulated farms have experienced recontamination after cleaning and disinfecting and months of not having cattle, suggesting persistence of M. bovis in contaminated plants, soil, and water. The question remains as to whether M. bovis persists in the environment for long periods of time and is capable of causing new outbreaks. We show that M. bovis in the environment is a risk for cattle if some key environmental conditions are present: appropriate substrate, temperature, desiccation, and sunlight.

Tuberculosis (TB) is an infectious disease transmitted by aerosol droplets and characterized by forming granulomatous lesions. Although the number of people infected in the population is high, the vast majority does not exhibit symptoms of active disease and only 5-10% develop the disease after a latent period that can vary from weeks to years. The bases of the immune response for this resistance are unknown, but it depends on a complex interaction between the environment, the agent, and the host. The analysis of cellular components of M. tuberculosis shows important host-pathogen interactions, metabolic pathways, virulence mechanisms, and mechanisms of adaptation to the environment. However, the M. tuberculosis proteome still remains largely uncharacterized in terms of virulence and pathogenesis. Here, we summarize some of the major proteomic studies performed to scrutinize all the mycobacterial components.