Comparison of Mycobacterium avium subsp. paratuberculosis infection in cattle, sheep and goats in the Khuzestan Province of Iran: Results of a preliminary survey

First serological diagnosis of Mycobacterium avium subsp. paratuberculosis infection in sheep in the state of Pernambuco, Brazil

This study aimed to diagnose Mycobacterium avium subsp. paratuberculosis (MAP) infections in sheep in the state of Pernambuco, Brazil. A total of 276 blood samples were analyzed using the enzyme-linked immunosorbent assay IDEXX Paratuberculosis Screening kit, and 261 fecal samples were submitted for bacterial culture and polymerase chain reaction tests. An animal-level sero-frequency of 0.72% (n = 2/276) and a farm-level sero-frequency of 20% (n = 2/10) were found. All fecal sample cultures were negative, and molecular analyses were also negative. To the best of our knowledge, this is the first study of MAP infection in sheep in the state of Pernambuco and one of the pioneers in the country. It is an asymptomatic disease that is difficult to diagnose in this species because the susceptibility of sheep to the organism is lower than that of other ruminant species. However, the sero-frequency found reveals that there is MAP exposure in sheep flocks in the region. In addition, serological monitoring can contribute to the observation of the organism's behavior in herds. Our results support the potential risk of MAP infection in sheep in the state of Pernambuco, Brazil.

Prevalence of paratuberculosis in cattle in China: A systematic review and meta-analysis

Bovine paratuberculosis is a chronic infectious disease caused by Mycobacterium avium subspecies paratuberculosis (MAP). Here, a systematic literature review was conducted to investigate the bovine paratuberculosis distribution and associated risk factors in China before 2022. The databases CNKI, VIP, WanFang, PubMed, and ScienceDirect were used to search for articles. The random effect model of the "Meta" package of "R" software was used, and the Arcsine transformation was chosen for the rate conversion analysis. To reveal the factors that led to research heterogeneity, the research data were used for subgroup analysis and univariate meta-regression analysis. Among the 1238 identified articles, 54 met the eligibility criteria. Based on data obtained from the selected articles, the combined positive rate of bovine paratuberculosis was 6.95% in China. In the sampling year subgroup, the positive rate of bovine paratuberculosis before 2013 was 4.94%, which was lower than in other time periods. In the sampling season subgroup, the highest positive rate of bovine paratuberculosis in cattle was 14.60% in the autumn. Furthermore, in the detection method subgroup, the highest positive rate of bovine paratuberculosis was 7.21%, which was detected by using ELISA. In the age subgroup, the positive rate of bovine paratuberculosis was 17.47% in cattle > 12 months old, significantly higher than other age subgroups. The highest positive rate of bovine paratuberculosis was 11.35% for female cattle in the gender subgroup, while in the geographic region subgroup, the highest positive rate was 8.12% for East China, which was significantly higher than in other regions. The highest positive rate of bovine paratuberculosis was for dairy cattle (8.00%), and the highest positive rate by rearing method was 11.03% for non-scale farming. The effects of different geographical and climatic factors on the positive rate of bovine paratuberculosis were evaluated. In summary, we recommend focusing on screening cattle infected with MAP in warm and humid areas.

Analysis of long non-coding RNA expression profile of bovine monocyte-macrophage infected by Mycobacterium avium subsp. paratuberculosis

Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis. As a potential zoonotic pathogen, MAP also seriously threatens human health and social security. At present, long non-coding RNA (lncRNA) has attracted wide attention as an useful biomarker in various diseases. Therefore, our study analyzed the lncRNA expression profiles and lncRNA-mRNA regulatory network of MAP infected bovine monocytes-macrophages and uninfected bovine cells by high-throughput sequencing. A total of 4641 differentially expressed lncRNAs genes were identified, including 3111 up-regulated genes and 1530 down-regulated genes. In addition, lncRNA-mRNA interaction analysis was performed to predict the target genes of lncRNA. Among them, after MAP infection, 86 lncRNAs targeted to mRNA, of which only 6 genes were significantly different. The results of Gene Ontology (GO) enrichment analysis showed that the differentially expressed genes significantly enriched in functional groups were related to immune regulation. Multiple signal pathways including NF-κB, NOD-like receptor, Cytokine-cytokine receptor, Toll-like receptor signaling pathway, Chemokine signaling pathway, and other important biochemical, metabolic and signal transduction pathways were enriched in Kyoto Encyclopedia of Genes and Genomes (KEGG). In this study, analysis of macrophage transcriptomes in response to MAP infection is expected to provide key information to deeply understand role of the pathogen in initiating an inappropriate and persistent infection in susceptible hosts and molecular mechanisms that might underlie the early phases of paratuberculosis.

Mycobacterium avium subsp. paratuberculosis and Hashimoto’s thyroiditis: Is MAP the trigger?

Hashimoto’s thyroiditis (HT) is an autoimmune disorder of the thyroid gland that can cause hypothyroidism. As HT is a multifactorial disorder, activation of immune responses in genetically predisposed individuals exposed to some environmental factors can contribute to it. Microorganisms, as environmental factors, including Mycobacterium avium ssp. paratuberculosis (MAP) by molecular mimicry, can be important in this autoimmune disorder. This study aimed to investigate the association between MAP and HT. This case–control study included 110 participants consisting of 60 HT patients and 50 healthy controls (HCs). Blood samples were collected. Nested PCR of the IS900 gene determined the presence of MAP DNA. The enzyme-linked immunosorbent assay (ELISA) was designed to identify antibodies (Abs) against the MAP3865c epitope, which has a homologous sequence with ZnT8 in the sera. The demographic information of all participants was recorded. Anti-TG, anti-TPO, TSH, anemia, and ruminant exposure were higer in HT patients than in the HCs (p < 0.05). MAP IS900 was detected significantly more in the patients (46.6% consisting of 30, 8.3, and 8.3% in clinical, subclinical, and unknown) than in the HCs (14%). The sera showed a remarkable frequency of reactivity against MAP3865c in the patients (38.3%) in comparison to the HCs (10%) (p = 0.0001). Furthermore, a significantly higher rate of livestock contact and traditional dairy consumption was found in individuals with MAP or anti-MAP3865c Abs positive result (p < 0.05). This study suggests a possible link between MAP and HT. These findings indicated that MAP frequency was not statistically different in the severity of HT and its shift into the clinical and subclinical forms; therefore, it could be assumed that MAPs are the initiators of the process. The results imply on a possible zoonosis transmission route of MAP from livestock products to humans. Further research is needed to confirm these results in larger groups of HT patients.

Paratuberculosis: The Hidden Killer of Small Ruminants

Simple Summary

Paratuberculosis is a chronic disease of ruminants and many non-ruminant animals caused by the bacterium Mycobacterium avium subsp. paratuberculosis. Affected animals show diarrhoea, loss of weight, and decreased production performance with consequent economic losses. This bacterium has been detected in some humans suffering from a chronic intestinal disease known as Crohn’s disease (CD) and, therefore, some scientists believe that CD is the human form of paratuberculosis. The disease in small ruminants has been reported in all continents, with goats being more susceptible than sheep. The clinical signs of the disease in goats are not so obvious as often do not show signs of diarrhoea, and the animal may die before being finally diagnosed. In Africa and many developing countries, paratuberculosis is described as a “neglected disease” particularly in small ruminants, which play a vital role in the livelihood of poor communities. This overview attempts to highlight the current research and gaps on this disease in small ruminants to draw more attention for further studies on diagnosis, prevention and control.

Abstract

Paratuberculosis (PTB) is a contagious and chronic enteric disease of ruminants and many non-ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP), and is characterised by diarrhoea and progressive emaciation with consequent serious economic losses due to death, early culling, and reduced productivity. In addition, indirect economic losses may arise from trade restrictions. Besides being a production limiting disease, PTB is a potential zoonosis; MAP has been isolated from Crohn’s disease patients and was associated with other human diseases, such as rheumatoid arthritis, Hashimoto’s thyroiditis, Type 1 diabetes, and multiple sclerosis. Paratuberculosis in sheep and goats may be globally distributed though information on the prevalence and economic impact in many developing countries seem to be scanty. Goats are more susceptible to infection than sheep and both species are likely to develop the clinical disease. Ingestion of feed and water contaminated with faeces of MAP-positive animals is the common route of infection, which then spreads horizontally and vertically. In African countries, PTB has been described as a “neglected disease”, and in small ruminants, which support the livelihood of people in rural areas and poor communities, the disease was rarely reported. Prevention and control of small ruminants’ PTB is difficult because diagnostic assays demonstrate poor sensitivity early in the disease process, in addition to the difficulties in identifying subclinically infected animals. Further studies are needed to provide more insight on molecular epidemiology, transmission, and impact on other animals or humans, socio-economic aspects, prevention and control of small ruminant PTB.

A serosurvey of Mycobacterium avium subsp. paratuberculosis infection of goats in the North of Portugal

To better understand the epizootiology of caprine paratuberculosis in the North of Portugal, a cross-sectional study was conducted from 2014 to 2015. The seroprevalence and risk factors for Mycobacterium avium subsp. paratuberculosis (Map) seropositivity were evaluated. Antibodies against Map were determined by a commercial ELISA. In 936 sera tested from 56 goat herds, 120 (12.8%, 95% CI: 10.8-15.1%) goats and 34 (60.7%, 95% CI: 47.6-72.4%) herds were positive. Risk factors for seropositivity were investigated by logistic regression models. The odds of Map seropositivity were found to be higher for animals with clinical signs, OR = 5.1 (95% CI: 2.7-9.6%), animals belonging to herds with previous wasting disease, OR = 2.3 (95% CI: 1.1-4.8%), and accumulation of manure in the herd, OR = 3.1 (95% CI: 1.7-5.7%). The potential risk factors identified in this study support the current recommendations for the control of paratuberculosis in these and other animals.