A longitudinal study of environmental mycobacteria on a farm in south-west England

Donoghue, Helen D.; Overend, E.; Stanford, J. L.

doi:10.1111/j.1365-2672.1997.tb03297.x

Cited by 31 publications

(33 citation statements)

References 31 publications

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“…2), corresponding to spring and early summer in Northern Ireland. This is in contrast to a number of studies on the isolation of mycobacteria that, in general, found a greater incidence during the summer and autumn months (10,22). With respect to this survey, the incidence of M. avium subsp.…”

Section: Discussioncontrasting

confidence: 51%

Occurrence of Mycobacterium avium subsp. paratuberculosis in Untreated Water in Northern Ireland

Whan

Ball²,

Grant

et al. 2005

Appl Environ Microbiol

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Mycobacterium avium subsp. paratuberculosis is the known cause of Johne's disease of both domestic and wild ruminants and has been implicated as a possible cause of Crohn's disease in humans. The organism is shed in the feces of infected animals and can survive for protracted periods in the environment and hence could be present in catchment areas receiving agricultural runoff. A limited survey was undertaken in Northern Ireland to test for M. avium subsp. paratuberculosis in untreated water entering nine water treatment works (WTWs) over a 1-year period. Three detection methods were employed, viz., immunomagnetic separation-PCR and culture on Herrold's egg yolk medium (HEYM) and BACTEC 12B medium, the latter both supplemented with mycobactins. Of the 192 untreated water samples tested, 15 (8%) tested M. avium subsp. paratuberculosis positive by one or more of the three detection methods. M. avium subsp. paratuberculosis was successfully isolated from eight untreated water samples, three by BACTEC culture and five by culture on HEYM. Although the highest incidence of M. avium subsp. paratuberculosis was found in spring, overall, there was no statistically significant difference between the seasons. No significant correlation was found between numbers of coliforms or fecal coliforms and the presence of M. avium subsp. paratuberculosis. In general, a higher incidence of M. avium subsp. paratuberculosis was found in untreated water entering those WTWs that had a high mean water pH value over the sampling period. This work indicates the need to determine the efficacy of water treatment processes to either kill or remove M. avium subsp. paratuberculosis from untreated water and the possible risks posed by contact with recreational water sources.

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Section: Discussioncontrasting

confidence: 51%

Occurrence of Mycobacterium avium subsp. paratuberculosis in Untreated Water in Northern Ireland

Whan

Ball²,

Grant

et al. 2005

Appl Environ Microbiol

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“…Even though our results do not throw light on the reason for this, we can suppose that these effects result from exposure to environmental mycobacteria, which can sensitize the animals. Indeed, other authors (9,14,15,22) have advanced the hypothesis that the contamination of feed with environmental mycobacteria, present in bird feces, and possible contact with other natural vehicles of infection, could induce a nonspecific reaction in the TB skin test. With regard to age, we noted that the risk of sensitization is higher for cows 2 to 3 and 4 to 5 years old than for cows 6 to 7 years old.…”

Section: Discussionmentioning

confidence: 99%

Analysis of Possible Factors Affecting the Specificity of the Gamma Interferon Test in Tuberculosis-Free Cattle Herds

Cagiola

Feliziani

Severi

et al. 2004

Clin Vaccine Immunol

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Bovine tuberculosis (TB) is still a zoonotic problem in the world. Despite the fact that eradication programs for bovine TB are being implemented in many countries, it remains a public health problem. These programs are mainly based on a single intradermal tuberculin test using bovine tuberculin purified protein derivative (PPD), isolation, and slaughtering of infected animals. The aim of this study was to assess the specificity of the gamma interferon (IFN-␥) test in TB-free cattle herds, by using not only Australian tuberculins but also tuberculins produced at our institute, and to correlate the response with the type of production (beef cattle, dairy cattle, and a dual-purpose breed), the housing system, and the age of the animals. We studied 800 animals selected from 20 TB-and paratuberculosis-free herds. The animals were tested in parallel, after stimulation with Australian tuberculins and tuberculins produced at our institute, by using the skin test and two IFN-␥ assays. The results of this trial showed that the specificity of the IFN-␥ test is higher than that of the skin test (96.8%) and ranges from 97.3% (using only Australian tuberculins) to 98.6% (using tuberculins produced at our institute). We found that different categories of cattle could influence the specificity of the skin test but that these differences tended to be reduced in the IFN-␥ assay, especially when Italian PPDs were used.

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“…For the enumeration of Legionella and Mycobacterium spp., aliquots of the samples were pretreated either with heat (at 50°C in a water bath for 30 min) or with acid (1 ml of sample added to 1 ml of 1 M HCl for 15 min and then neutralized with KOH [4,13]). Aliquots of untreated and treated samples were then plated onto BCYE agar for the enumeration of Legionella spp.…”

Section: Methodsmentioning

confidence: 99%

Microbial Biofilm Formation and Contamination of Dental-Unit Water Systems in General Dental Practice

Walker

Bradshaw

Bennett

et al. 2000

Appl Environ Microbiol

196

166

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Dental-unit water systems (DUWS) harbor bacterial biofilms, which may serve as a haven for pathogens. The aim of this study was to investigate the microbial load of water from DUWS in general dental practices and the biofouling of DUWS tubing. Water and tube samples were taken from 55 dental surgeries in southwestern England. Contamination was determined by viable counts on environmentally selective, clinically selective, and pathogen-selective media, and biofouling was determined by using microscopic and image analysis techniques. Microbial loading ranged from 500 to 10 5 CFU ⅐ ml ؊1; in 95% of DUWS water samples, it exceeded European Union drinking water guidelines and in 83% it exceeded American Dental Association DUWS standards. Among visible bacteria, 68% were viable by BacLight staining, but only 5% of this "viable by BacLight" fraction produced colonies on agar plates. Legionella pneumophila, Mycobacterium spp., Candida spp., and Pseudomonas spp. were detected in one, five, two, and nine different surgeries, respectively. Presumptive oral streptococci and Fusobacterium spp. were detected in four and one surgeries, respectively, suggesting back siphonage and failure of antiretraction devices. Hepatitis B virus was never detected. Decontamination strategies (5 of 55 surgeries) significantly reduced biofilm coverage but significantly increased microbial numbers in the water phase (in both cases, P < 0.05). Microbial loads were not significantly different in DUWS fed with soft, hard, deionized, or distilled water or in different DUWS (main, tank, or bottle fed). Microbiologically, no DUWS can be considered "cleaner" than others. DUWS deliver water to patients with microbial levels exceeding those considered safe for drinking water.

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A longitudinal study of environmental mycobacteria on a farm in south-west England

Cited by 31 publications

References 31 publications

Occurrence of Mycobacterium avium subsp. paratuberculosis in Untreated Water in Northern Ireland

Occurrence of Mycobacterium avium subsp. paratuberculosis in Untreated Water in Northern Ireland

Analysis of Possible Factors Affecting the Specificity of the Gamma Interferon Test in Tuberculosis-Free Cattle Herds

Microbial Biofilm Formation and Contamination of Dental-Unit Water Systems in General Dental Practice

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