Molecular epidemiology of Types I/III strains of Mycobacterium avium subspecies paratuberculosis isolated from goats and cattle.
ABSTRACT Molecular characterization of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) isolates classifies them into three groups: cattle or Type II, sheep or Type I, and intermediate or Type III. To avoid problems associated with characterization of extremely slow growth strains, PCR-based techniques that divide the M. a. paratuberculosis strains in two main groups (cattle or Type II, and sheep or Types I/III) can be performed. The objectives of this study were to characterize the M. a. paratuberculosis isolates identified by different PCR-based tests (IS1311-PCR and restriction endonuclease analysis, PCR test based on a DNA sequence difference, and a PCR aimed at three Type I-specific loci), and to determine the clinical and epidemiological implications of Types I/III M. a. paratuberculosis strains in livestock. One hundred and fifty-eight M. a. paratuberculosis strains from domestic ruminants were analyzed. One hundred and six M. a. paratuberculosis isolates (61 from goats and 45 from cattle) were classified as Type II strains; and 52 (29 from cows, 20 from goats, and three from sheep) were included in the Types I/III. The Types I/III M. a. paratuberculosis strains were associated to Spanish native breeds. The majority of these animals had not been in direct or indirect contact with sheep flocks infected with M. a. paratuberculosis. This fact should be taken into account when implementing paratuberculosis control programs.
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ABSTRACT: A combination of representational difference analysis and comparative DNA sequencing revealed that four type I (sheep) isolates of Mycobacterium avium subsp. paratuberculosis were differentiated from nine type II (bovine) isolates by the presence of an 11-bp insertion in a novel M. avium subsp. paratuberculosis-specific region of genomic DNA. Further, our studies show that M. avium subsp. paratuberculosis type I isolates contain three type-specific loci that are missing in M. avium subsp. paratuberculosis type II but are present in M. avium subsp. avium. Taken together, the results are consistent with the hypothesis that M. avium subsp. paratuberculosis type I strains are an evolutionary intermediate between M. avium subsp. avium and M. avium subsp. paratuberculosis type II isolates or share a subset of M. avium subsp. avium type-specific loci through horizontal transfer.Journal of Clinical Microbiology 12/2003; 41(11):5215-23. · 4.07 Impact Factor
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ABSTRACT: Sixty-eight adult goats with clinical or sub-clinical paratuberculosis, from naturally infected flocks, were subjected post mortem to a pathological examination that focused on the intestinal lymphoid tissue. The lesions were divided into four categories. Focal lesions, found in 16 goats, consisted of small granulomata in the ileocaecal Peyer's patches or related lamina propria. Diffuse multibacillary lesions (34 goats) consisted of a granulomatous enteritis, affecting different intestinal sites. Numerous macrophages containing many mycobacteria were present, resulting in macroscopical changes in the normal gut morphology; in the ileum of nine of the 34 animals, however, these changes were confined to the apex of the villi and the intestinal wall was not thickened. In diffuse lymphocytic lesions (10 goats), the lymphocyte was the main inflammatory cell, with some macrophages (containing few if any mycobacteria). In diffuse mixed lesions (eight goats) the infiltrate consisted of numerous lymphocytes and macrophages, with small numbers of mycobacteria. The three types of diffuse lesion were often associated with necrosis in the lymph vessels of the mucosa, mesentery and lymph nodes, and with greater thickening of the jejunum than of the ileum. Mycobacterium avium subspecies paratuberculosis was cultured from 69% of goats with diffuse lesions and from 44.4% of those with focal lesions.Journal of Comparative Pathology 06/2000; 122(4):255-65. · 1.38 Impact Factor
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ABSTRACT: Paratuberculosis in goats occurs worldwide causing considerable economic losses mainly due to reduced milk production. Nowadays, there is still relatively little knowledge about the epidemiology of this disease in goats, and only a few epidemiological studies have been carried out in goats naturally infected with Mycobacterium avium subspecies paratuberculosis (M. a. paratuberculosis). The objective of this study was to characterize forty four clinical caprine isolates of M. a. paratuberculosis by different molecular techniques (pulsed-field gel electrophoresis [PFGE], restriction fragment length polymorphism analysis coupled with hybridization to IS900, and IS1311 polymerase chain reaction-restriction enzyme analysis) to determine the most useful technique for molecular typing of caprine isolates, as well as to disclose the genetic variation amongst caprine isolates and the relationship with strains isolated from other animal species. PFGE was found to be the most discriminative technique identifying a total of 13 'multiplex' PFGE profiles, ten of which were novel profiles found only in caprine isolates to date. All isolates were genotyped as Type II strains, except two isolates that resembled the intermediate group referred as Type III.Veterinary Microbiology 05/2005; 106(3-4):249-57. · 3.13 Impact Factor