Association of Fasciola gigantica co-infection with bovine tuberculosis infection and diagnosis in a naturally infected cattle population in Africa

Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a major livestock and public health problem in both high and low-income countries. With the current absence of an effective vaccine, control in cattle populations is reliant on regular testing and removal of positive animals. However, surveillance and control are hampered by imperfect diagnostic tests that have poorly described properties in naturally infected populations. Recent research in cattle co-infected with the temperate liver fluke, Fasciola hepatica, has raised concerns about the performance of the intradermal skin test in high fluke incidence areas. Further, recent studies of parasitic co-infections have demonstrated their impact on Th1 and Th2 responses, concurrent disease pathology and susceptibility to mycobacterial infections. Here we report for the first time the association of co-infection with the tropical liver fluke, Fasciola gigantica, with the presence of bTB-like lesions and the IFN-γ response in naturally infected African cattle. After adjusting for age and sex we observed a complex interaction between fluke status and breed. Fulani cattle had a higher risk of having bTB-like lesions than the mixed breed group. The risk of bTB-like lesions increased in the mixed breed group if they had concurrent evidence of fluke pathology but was less clear in the coinfected Fulani breed. Further, we observed a slight decline in the IFN-γ levels in fluke infected animals. Finally we explored factors associated with IFN-γ false negative results compared to the presence of bTB-like lesions. Fulani cattle had a higher risk of having a false negative result compared to the mixed breed group. Further, the mixed breed cattle had an increased risk of being false negative if also co-infected with fluke. Interesting, as with the risk of bTB-like lesions, this association was less clear in the Fulani cattle with weak evidence of a slight decrease in risk of having a false negative test result when fluke pathology positive. This interesting interaction where different breeds appear to have different responses to co-infections is intriguing but further work is needed to confirm and understand more clearly the possible confounding effects of different other co-infections not measured here, breed, management or exposure risks

The Influence of Parasite Infections on Host Immunity to Co-Infection with Other Pathogens

Parasites have evolved a wide range of mechanisms that they use to evade or manipulate the host's immune response and establish infection. The majority of the in vivo studies that have investigated these host-parasite interactions have been undertaken in experimental animals, especially rodents, which were housed and maintained to a high microbiological status. However, in the field situation it is increasingly apparent that pathogen co-infections within the same host are a common occurrence. For example, chronic infection with pathogens including malarial parasites, soil-transmitted helminths, Mycobacterium tuberculosis and viruses such as HIV may affect a third of the human population of some developing countries. Increasing evidence shows that co-infection with these pathogens may alter susceptibility to other important pathogens, and/or influence vaccine efficacy through their effects on host immune responsiveness. Co-infection with certain pathogens may also hinder accurate disease diagnosis. This review summarizes our current understanding of how the host's immune response to infection with different types of parasites can influence susceptibility to infection with other pathogenic microorganisms. A greater understanding of how infectious disease susceptibility and pathogenesis can be influenced by parasite co-infections will enhance disease diagnosis and the design of novel vaccines or therapeutics to more effectively control the spread of infectious diseases

Co-infection of cattle with Fasciola hepatica or F. gigantica and Mycobacterium bovis: A systematic review

The liver flukes, Fasciola hepatica and F. gigantica, are common trematode parasites of livestock. F. hepatica is known to modulate the immune response, including altering the response to co-infecting pathogens. Bovine tuberculosis (bTB), caused by Mycobacterium bovis, is a chronic disease which is difficult to control and is of both animal welfare and public health concern. Previous research has suggested that infection with liver fluke may affect the accuracy of the bTB skin test, but direction of the effect differs between studies. In a systematic review of the literature, all experimental and observational studies concerning co-infection with these two pathogens were sought. Data were extracted on the association between fluke infection and four measures of bTB diagnosis or pathology, namely, the bTB skin test, interferon γ test, lesion detection and culture/bacterial recovery. Of a large body of literature dating from 1950 to 2019, only thirteen studies met the inclusion criteria. These included studies of experimentally infected calves, case control studies on adult cows, cross sectional abattoir studies and a herd level study. All the studies had a medium or high risk of bias. The balance of evidence from the 13 studies included in the review suggests that liver fluke exposure was associated with either no effect or a decreased response to all of the four aspects of bTB diagnosis assessed: skin test, IFN γ, lesion detection and mycobacteria cultured or recovered. Most studies showed a small and/or non-significant effect so the clinical and practical importance of the observed effect is likely to be modest, although it could be more significant in particular groups of animals, such as dairy cattle

The immunoregulatory effects of co-infection with Fasciola hepatica: From bovine tuberculosis to Johne's disease

Fasciola hepatica (liver fluke) is a parasite prevalent in much of the world that causes the economically-important disease of fasciolosis in livestock. The threat that this disease poses extends beyond its direct effects due to the parasite's immunomodulatory effects. Research at this laboratory is focusing on whether this immunoregulation can, in animals infected with liver fluke, exert a bystander effect on concurrent infections in the host. It has already been established that F. hepatica infection reduces cell mediated immune responses to Mycobacterium bovis in cattle, and that the interaction between the two pathogens can be detected on an epidemiological scale. This review explores the immunological consequences of co-infection between F. hepatica and other bacterial infections. Arguments are presented suggesting that immunity of cattle to Mycobacterium avium subsp. paratuberculosis is also likely to be affected.European Commission Horizon 202

Antibody recognition of cathepsin L1-derived peptides in Fasciola hepatica-infected and/or vaccinated cattle and identification of protective linear epitopes

Fasciola hepatica infection causes important economic losses in livestock and food industries around the world. In the Republic of Ireland F. hepatica infection has an 76% prevalence in cattle. Due to the increase of anti-helminthic resistance, a vaccine-based approach to control of Fasciolosis is urgently needed. A recombinant version of the cysteine protease cathepsin L1 (rmFhCL1) from F. hepatica has been a vaccine candidate for many years. We have found that vaccination of cattle with this immunodominant antigen has provided protection against infection in some experimental trials, but not in others. Differential epitope recognition between animals could be a source of variable levels of vaccine protection. Therefore, we have characterised for first time linear B-cell epitopes recognised within the FhCL1 protein using sera from F. hepatica-infected and/or vaccinated cattle from two independent trials. Results showed that all F. hepatica infected animals recognised the region 19–31 of FhCL1, which is situated in the N-terminal part of the pro-peptide. Vaccinated animals that showed fluke burden reduction elicited antibodies that bound to the regions 120–137, 145–155, 161–171 of FhCL1, which were not recognised by non-protected animals. This data, together with the high production of specific IgG2 in animals showing vaccine efficacy, suggest important targets for vaccine development.European Commission Horizon 202

Antibody recognition of cathepsin L1-derived peptides in Fasciola hepatica-infected and/or vaccinated cattle and identification of protective linear B-cell epitopes

© 2018 Elsevier Ltd Fasciola hepatica infection causes important economic losses in livestock and food industries around the world. In the Republic of Ireland F. hepatica infection has an 76% prevalence in cattle. Due to the increase of anti-helminthic resistance, a vaccine-based approach to control of Fasciolosis is urgently needed. A recombinant version of the cysteine protease cathepsin L1 (rmFhCL1) from F. hepatica has been a vaccine candidate for many years. We have found that vaccination of cattle with this immunodominant antigen has provided protection against infection in some experimental trials, but not in others. Differential epitope recognition between animals could be a source of variable levels of vaccine protection. Therefore, we have characterised for first time linear B-cell epitopes recognised within the FhCL1 protein using sera from F. hepatica-infected and/or vaccinated cattle from two independent trials. Results showed that all F. hepatica infected animals recognised the region 19–31 of FhCL1, which is situated in the N-terminal part of the pro-peptide. Vaccinated animals that showed fluke burden reduction elicited antibodies that bound to the regions 120–137, 145–155, 161–171 of FhCL1, which were not recognised by non-protected animals. This data, together with the high production of specific IgG2 in animals showing vaccine efficacy, suggest important targets for vaccine development

Fasciola hepatica infection reduces Mycobacterium bovis burden and mycobacterial uptake and suppresses the pro-inflammatory response

Bovine tuberculosis (BTB), caused by Mycobacterium bovis, has an annual incidence in cattle of 0.5% in the Republic of Ireland and 4.7% in the UK, despite long-standing eradication programmes being in place. Failure to achieve complete eradication is multifactorial, but the limitations of diagnostic tests are significant complicating factors. Previously, we have demonstrated that Fasciola hepatica infection, highly prevalent in these areas, induced reduced sensitivity of the standard diagnostic tests for BTB in animals co-infected with F. hepatica and M. bovis. This was accompanied by a reduced M. bovis-specific Th1 immune response. We hypothesized that these changes in co-infected animals would be accompanied by enhanced growth of M. bovis. However, we show here that mycobacterial burden in cattle is reduced in animals co-infected with F. hepatica. Furthermore, we demonstrate a lower mycobacterial recovery and uptake in blood monocyte-derived macrophages (MDM) from F. hepatica-infected cattle which is associated with suppression of pro-inflammatory cytokines and a switch to alternative activation of macrophages. However, the cell surface expression of TLR2 and CD14 in MDM from F. hepatica-infected cattle is increased. These findings reflecting the bystander effect of helminth-induced downregulation of pro-inflammatory responses provide insights to understand host-pathogen interactions in co-infection

Todos contamos para mejorar

Seleccionado en la convocatoria: Ayudas para desarrollar proyectos de convivencia, Gobierno de Aragón 2008-09El colegio público Domingo Jímenez Beltrán realiza una serie de actuaciones para mejorar la convivencia escolar y la interculturalidad. Se han adaptado las actividades para poder realizarlas por las diferentes etapas teniendo en cuenta la atención a la diversidad del alumnado: reunión de principio de curso para cada ciclo; entrevistas personales y tutorías; protocolo de acogida; relaciones con diferentes instituciones; refuerzo de la autoestima positiva; solución de conflictos y cooperación; semana de la paz; mes de la naturaleza; y celebraciones en las diferentes culturas. Se han elaborado diferentes materiales: cuentos y cómics individuales, juegos e instrumentos musicales elaborados con materiales de reciclaje, un calendario de convivencia, murales y banco de actividades de habilidades sociales.Gobierno de Aragón. Departamento de Educación, Cultura y DeporteAragónDirección General de Política Educativa; Avda. Gómez Laguna, 25, planta 2; 50009 Zaragoza; Tel. +34976715416; Fax +34976715496ES