Clinical, histopathological, and molecular findings for Mycobacterium avium subspecies paratuberculosis (MAP) in dairy goats under semiarid conditions

The objective of this study was to report the occurrence of Mycobacterium avium subspecies paratuberculosis (MAP) in dairy goats, via description of their clinical presentation, histopathological findings, and molecular identification of the infectious agent. Screening was performed using IS900 real-time PCR (qPCR) in milk samples from 179 properties in the semiarid of Northeast region of Brazil. Pooled milk samples from all lactating goats from processing plants were submitted to molecular diagnosis. One property had a positive result at qPCR. The production unit which had the positive sample for MAP was located, and an on-site visit to this property was performed to collect individual milk samples, seven of which tested MAP positive by IS900 qPCR. With permission from the owner, two goats (Animal 1 was positive and Animal 2 was negative on first qPCR for MAP) were acquired and euthanized. Animals 1 and 2 had milk and portions of the duodenum, ileum, colon, and mesenteric lymph nodes positive at qPCR for MAP. Animal 1 also had MAP DNA detected in part of the jejunum and cecum. In animal 2, the ileocecal valve tested positive. MAP was not detected in the blood or feces of either animal; however; it was confirmed for the association of clinical findings, histopathology, and qPCR. The gene IS900 from the positive samples were sequenced and showed a 99% similarity with MAP. The MAP was identified for the first time in the goat milk and tissues in the semiarid region of Northeast Brazil.

Antibody detection and molecular analysis for Mycobacterium avium subspecies paratuberculosis (MAP) in goat milk: Systematic review and meta-analysis

Paratuberculosis is an incurable infectious disease that affects several species, including goat (Capra hircus). The etiologic agent is Mycobacterium avium subspecies paratuberculosis (MAP) that has tropism for the intestine, causing anorexia, progressive weight loss and death. In goats, the main transmission route is the ingestion of water and food contaminated by infected feces. Affected animals also eliminate the agent through milk, with a potential biological risk to public health. Thus, the aim of this study was to conduct a research of the literature available in electronic media for a systematic review, followed by a meta-analysis of the results found on prevalence and diagnostic tests adopted in the detection of MAP antibodies and DNA in goat milk. The following search parameters were used: "Mycobacterium avium subsp. paratuberculosis" AND (goat OR small ruminant) AND (milk OR pasteurized milk). Strictly obeying pre-established criteria, 437 articles were selected from the respective electronic databases of scientific content: ScienceDirect (285), PubMed (68), Web of Science (60) and Scopus (24), of which nine papers were elected to the construction of the systematic review and meta-analysis. The prevalence of MAP antibodies in milk detected by milk-ELISA ranged from 1.1 to 67.7% and the prevalence of MAP DNA in goat milk detected by MAP-specific polymerase chain reaction (PCR) ranged from 1.94 to 37.74%. A meta-analysis indicated a combined MAP infection prevalence of 8.24%, but with high heterogeneity among study findings (I² = 98.7%). The identification of the MAP in goat milk implies the need for surveillance of the agent in order to prevent economic losses and impact on public health.

Inhibition of Escherichia coli invasion into bovine mammary epithelial cells previously infected by Mycobacterium avium subsp. paratuberculosis

Background

The coinfection process of Escherichia coli, an etiological agent of clinical mastitis and Mycobacterium avium subsp. paratuberculosis (MAP), a non-mastitic etiological agent in the bovine mammary gland is not fully known.

Objective

Verify the ability of MAP to interfere with the invasion and translocation of E. coli in bovine mammary epithelial cell line (MAC-T).

Methods

For the invasion assay, MAC-T cells were challenged with MAP K10 for 2 h and then challenged with E. coli for 10, 30 and 120 min. For the translocation assay, the trans well plates were used and the challenge sequence was repeated as previously described. The amount of E. coli in the assays was determined by counting colony forming units (CFU) in Luria-Bertani medium. Quantitative real-time PCR was used to quantify MAP in MAC-T cells. To verify the viability of the MAC-T cells, the MTT assay was performed. MAP culture supernatant was also evaluated at different percentages for E. coli growth.

Results

Previous MAP infection in MAC-T cells inhibited E. coli invasion in 10, 30 and 120 min. No significant interference of MAP in the translocation of E. coli from the apical-basal direction was verified. Quantity of MAP DNA inside the MAC-T cells was statistically similar. Neither reduction in MAC-T cells viability was detected during the experiment nor MAP-released factor in the supernatant inhibited E. coli invasion.

Conclusion

These findings suggest that MAP-positive cows could be more resistant to E. coli infection, but when infected, could rapidly translocate E. coli to the subepithelial region.

Paratuberculosis in dairy goat flocks from southern Spain: risk factors associated with seroprevalence

BACKGROUND

Paratuberculosis (PTB) is a chronic, enteric wasting disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP), with a worldwide distribution. Andalusia, located in southern Spain, is one of the European regions with the highest goat census and the highest milk production; however, current data on the prevalence of MAP in this species are not available.

METHODS

A cross-sectional study was performed to determine the seroprevalence and risk factors associated with PTB in dairy goat flocks from southern Spain. A total of 3312 serum samples were collected from 48 flocks located in three different geographical areas. Health and productive parameters were surveyed during the visit to the herds.

RESULTS

A total of 511 goats were seropositive, with overall true seroprevalence of 22.54 per cent (95 per cent confidence interval (CI₉₅) 21.12-23.97). Of the goat herds, 87.50 per cent (CI₉₅78.14-96.98) were seropositive. The intraherd seroprevalence was 25.43±31.71, distributed as follows: 22 flocks with a seroprevalence under 10 per cent; 18 flocks between 10 per cent and 50 per cent; and eight flocks with a frequency over 50 per cent. Multivariate logistic regression showed significant association between PTB seropositivity and the following variables: intensive production system, lack of management by batches, inappropriate ventilation and seropositivity to c aprine a rthritis e ncephalitis v irus ( CAEV ).

CONCLUSIONS

The results indicate a widespread PTB infection in goat herds in southern Spain. Thus, control programmes must include management and sanitary measures to reduce the prevalence. Further experimental studies are necessary to determine the influence of CAEV-PTB coinfection on immune status.