Isolation of conditionally pathogenic mycobacteria from the environment of one pig farm and the effectiveness of preventive measures between 1997 and 2003

Abstract

392Tuberculosis in pigs causes high economic losses farmers from all over the world. The most consequential causative agents of tuberculosis in pigs at present are members of Mycobacterium tuberculosis (MTC) and M. avium (MAC) complexes. The losses are above all caused by restriction of animal transport from infected farms (with the exception of slaughterhouses), culling of animals positive during the tuberculin testing and the price of meat and organs from slaughtered infected animals (Alfredsen and Skjerve 1993;Dey and Parham, 1993;Morita et al., 1994;Balian et. al., 1997;Cvetnic et al., 1998; Positive skin responses were found in animals with antibodies against MAH (18; 23.7%), MAA (3; 4.0%) and MI (9; 11.8%) antigens. By serological examination of 17 sows with repeated dubious responses for tuberculin skin testing with avian tuberculin, no antibodies against MAA were detected; MAH antibodies and MI antibodies were found in eight and two animals, respectively. By post mortem examination of lymph nodes (ln) and organ samples from all 76 animals with responses to avian tuberculin, no tuberculous/tuberculoid lesions were detected. By culture examination of ln and organs from 13 animals, conditionally pathogenic mycobacteria (CPM) were isolated from only one animal (breeding boar): from mesenteric, pulmonary, hepatic ln and from spleen tissue samples. These isolates were identified as MAH and CPM by the PCR method and biochemically. By investigation of the external environment (205 samples), 33 (16.3%) CPM isolates were obtained: 13 MAH, eight M. fortuitum, one M. nonchromogenicum, one M. abscessus, one M. scrofulaceum and nine unidentified isolates, which were non-MAC according to the PCR examination. Non-specific responses obtained in the intravital tests (skin and serological tests) caused by CPM present in the environment substantially complicated diagnosis of avian tuberculosis. Based on these findings, animal hygiene measures have been adopted since 2002; resulted in a decrease of environmental contamination with CPM and a reduction in the number of animals giving positive responses to avian tuberculin.

Mycobacteria in the environment of pig farms in the Czech Republic between 2003 and 2007

“…In our study, peat was the second most contaminated material, with a predominating occurrence of MAH (Tables 1 and 2). Its application as a feed supplement often caused formation of tuberculoid lesions in the lymph nodes of pigs Pavlik et al, 2007). However, natural peat constitutes an important source of atypical mycobacteria (Kazda, 2000;Kazda et al, 2009).…”

Distribution of non-tuberculosis mycobacteria in environmental samples from a slaughterhouse and in raw and processed meats

“…The main ecological niche for NTM is the environment, where they have been commonly isolated from soil and water (Pavlik et al 2000;Falkinham 2002), from feed and animal droppings (Dvorska et al 2007;Pavlik et al 2007), from non-vertebrates (Fischer et al 2001) and small terrestrial animals (Fischer et al 2000;Pavlik et al 2007). Despite this, NTM species such as members of the MAC, M. fortuitum and M. kansasii, have also been isolated from raw milk samples (Dunn & Hodgson 1982) and M. avium subsp.…”

Mycobacterium helveticum sp. nov., a novel slowly growing mycobacterial species associated with granulomatous lesions in adult swine

“…Although numerous mycobacteria, e.g. Mycobacterium fortuitum, Mycobacterium gordonae , Mycobacterium terrae , Mycobacterium chelonae , Mycobacterium smegmatis , Mycobacterium phlei and Mycobacterium scrofulaceum , can be involved in the formation of such lesions in domestic pigs, members of the M. avium complex are without doubt the most common [ 40 ]. ‘ M. avium subsp.…”