Article

Survival and Dormancy of Mycobacterium avium subsp. paratuberculosis in the Environment

Faculty of Veterinary Science, The University of Sydney, Sydney, Australia.
Applied and Environmental Microbiology (Impact Factor: 3.67). 06/2004; 70(5):2989-3004. DOI: 10.1128/AEM.70.5.2989-3004.2004
Source: PubMed

ABSTRACT

The survival of Mycobacterium avium subsp. paratuberculosis was studied by culture of fecal material sampled at intervals for up to 117 weeks from soil and grass in pasture plots and boxes. Survival for up to 55 weeks was observed in a dry fully shaded environment, with much shorter survival times in unshaded locations. Moisture and application of lime to soil did not affect survival. UV radiation was an unlikely factor, but infrared wavelengths leading to diurnal temperature flux may be the significant detrimental component that is correlated with lack of shade. The organism survived for up to 24 weeks on grass that germinated through infected fecal material applied to the soil surface in completely shaded boxes and for up to 9 weeks on grass in 70% shade. The observed patterns of recovery in three of four experiments and changes in viable counts were indicative of dormancy, a hitherto unreported property of this taxon. A dps-like genetic element and relA, which are involved in dormancy responses in other mycobacteria, are present in the M. avium subsp. paratuberculosis genome sequence, providing indirect evidence for the existence of physiological mechanisms enabling dormancy. However, survival of M. avium subsp. paratuberculosis in the environment is finite, consistent with its taxonomic description as an obligate parasite of animals.

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Available from: Richard J Whittington, Dec 01, 2014
    • "Microorganisms in this state failed to grow by standard bacteriological methods, but remained alive (Oliver, 2010). MAP has the ability to enter into a viable but non-cultivable (VBNC) state in the environment (Whittington et al., 2004) and under experimental cultivation conditions (Lamont et al., 2012). Further, MAP-related bacteria such as Mycobacterium smegmatis and Mycobacterium tuberculosis can enter the VBNC state, too. "
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    ABSTRACT: Although it has been known for years that Mycobacterium avium subsp. paratuberculosis (MAP) is detectable in the reproductive organs and semen of infected bulls, only few studies have been conducted on this topic worldwide. This study surveyed the MAP status of a bull, naturally infected due to close contact with its subclinically infected parents over a period of 4 years. From the age of 7 weeks to necropsy, faecal, blood and, after sexual maturity, semen samples were drawn repeatedly. Already at the first sampling day, MAP-DNA was detected in faeces by semi-nested PCR. True infection was confirmed by the detection of MAP-DNA in blood at the age of 40 weeks. In total, MAP-DNA was present in 25% faecal (34/139), 16% blood (23/140) and 5% semen (4/89) samples, including MAP-free intervals of up to 9 weeks. MAP genome equivalents (MAP-GE) of up to 6.3 × 10(6) /g faeces and 1.8 × 10(5) /ml blood were determined. Cultivation of MAP occurred only in three of 137 faecal and two of 109 blood, but never in semen samples. Over the whole period, the bull was a serological negative MAP shedder. During necropsy, 42 tissue samples were collected. Neither macroscopic nor histological lesions characteristic of a MAP infection were observed. Cultivation of MAP in tissue sections failed. However, MAP-DNA was spread widely in the host, including in tissues of the lymphatic system (7/15), digestive tract (5/14) and the urogenital tract (5/9) with concentrations of up to 3.9 × 10(6) MAP-GE/g tissue. The study highlighted the detection of MAP in male reproductive organs and semen. It supports the hypothesis that bulls may probably transmit MAP, at least under natural mating conditions. In artificial insemination, this might not be relevant, due to antibiotics included currently in semen extenders. However, the survivability of MAP in this microenvironment should be investigated in detail.
    No preview · Article · Dec 2015 · Transboundary and Emerging Diseases
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    • "This is of concern to disease control programs as M. avium subsp. paratuberculosis may persist in the environment, potentially surviving for around one year, although this is dependent on a range of environmental factors, particularly shade (Whittington et al., 2004, 2005). In Australia, the initial paratuberculosis control strategy was regulation and quarantine of infected properties, with destocking of infected sheep properties from the beginning of one summer to the end of the next advocated. "
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    ABSTRACT: Paratuberculosis is a chronic insidious, often serious, disease of the global small ruminant industries, mainly causing losses from mortalities and reduced productivity on-farm, interference in trading and, in Australia, profound socio-economic impacts that have periodically compromised harmony of rural communities. The pathogenesis, diagnosis, impacts and disease management options for ovine and caprine paratuberculosis are reviewed, comparing current controls in the extensive management system for sheep in wool flocks in Australia with the semi-intensive system of dairy flocks/herds in Greece. Improved understanding of the immune and cellular profiles of sheep with varying paratuberculosis outcomes and the recognition of the need for prolonged vaccination and biosecurity is considered of relevance to future control strategies. Paratuberculosis in goats is also of global distribution although the prevalence, economic impact and strategic control options are less well recognized, possibly due to the relatively meagre resources available for goat industry research. Although there have been some recent advances, more work is required on developing control strategies for goats, particularly in dairy situations where there is an important need for validation of improved diagnostic assays and the recognition of the potential impacts for vaccination. For all species, a research priority remains the identification of tests that can detect latent and subclinical infections to enhance removal of future sources of infectious material from flocks/herds and the food chain, plus predict the likely outcomes of animals exposed to the organism at an early age. Improving national paratuberculosis control programs should also be a priority to manage disease risk from trade. The importance of strong leadership and communication, building trust within rural communities confused by the difficulties in managing this insidious disease, reflects the importance of change management considerations for animal health authorities. Although concerns of vaccine efficacy, safety and issues with diagnosis and administration persist, vaccination is increasingly recognized as providing a robust strategy for managing paratuberculosis, having made important contributions to the health of Australian sheep and the lives of producers with affected properties, and offering a mechanism to reduce risk of infection entering the food chain in ovine and caprine products. Copyright © 2015 Elsevier B.V. All rights reserved.
    Full-text · Article · Jul 2015 · Veterinary Microbiology
    • "All livestock utilize communal pastures and ponds round the year. As described by several authors, MAP can survive in the favorable environment (contaminated pasture, soil, and water ponds) for months (Eisenberg et al. 2010; Whittington et al. 2004); these factors along with multispecies grazing at contaminated pastures may have contributed towards the maintenance and survival of "
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    ABSTRACT: Johne’s disease (JD) is an OIE (World Animal Health Organization) listed disease of ruminants including camels with serious economic impacts worldwide. A cross-sectional serological survey involves multistage simple random sampling to investigate the prevalence of JD in camels of Oman. In total, 2255 camels (254 male & 2001 female) and different ages from 553 geographically marked holdings were bled for serum. The samples were analyzed by a commercial indirect ELISA with protein ‘G’ as conjugate (LSI VET Ruminant Serum Paratuberculosis Advanced, France). Results indicated a wide spread herd and individual level seroprevalence respectively of 9.2 (0.7-50) and 2.6 percent in the Sultanate. Differences (p<0.01) were observed regarding the prevalence of JD in sampled governorates and highest prevalence was recorded in Dhofar (13.5%). Higher (p>0.05) seroprevalence was observed in females (2.8%) and their odds for testing positive were 3.69 (95%CI=0.90-15.23) times higher as compared to males (0.8%). Seropositivity increased with the age of camels and highest prevalence (4.4%) was observed in camels of more than 10 years of age (p=0.03). Large and medium size herds (OR=1.77, 95%CI=0.96-3.24) where camels were kept as single species (OR=1.54, 95%CI=0.84-2.84) and confined (OR=1.93, 95%CI=1.05-3.54) were found more likely to test positive. This is first record of seroprevalence of JD among the camels in the Sultanate which highlights their potential as an important host of the disease. The results advocate that a comprehensive control program based upon further risk analysis and molecular study should be devised in Oman.
    No preview · Article · Dec 2014 · Tropical Animal Health and Production
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