Tuberculous lesions in pig lymph nodes caused by kaolin fed as a supplement

Abstract

An increased incidence of tuberculous lesions in head and mesenteric lymph nodes from slaughtered pigs weighing about 115 kg was recorded in a herd of pigs kept in two farms A and B in the Czech Republic. Tuberculous lesions were more frequently (P < 0.01) diagnosed in pigs from Farm A (10.4%) than from Farm B (1.1%). The follow-up investigation of potential sources of infection on Farm A revealed that the piglets were fed kaolin from a nearby mine as a supplement. Among 20 samples from the pigs' environment, atypical conditionally pathogenic mycobacteria (ACPM) were detected in four samples as follows: dust (n = 2), pig faeces (n = 1) and kaolin fed as a supplement (n = 1). Mycobacterium avium subsp. hominissuis of genotype IS901-and IS1245+ and serotype 8 was isolated from kaolin and pig lymph nodes, M. fortuitum from stable dust and pig faeces and other ACPM from stable dust. When kaolin feeding to piglets ceased, the incidence of tuberculous lesions in these pigs at slaughter 5-6 months later decreased from 16.1% to 3.4%. No ACPM was detected on Farm B in 27 samples from the environment. An investigation of surface kaolin mines did not detect mycobacteria in non-extracted kaolin. However, surface water (three isolates among 13 samples) from the pond used for kaolin levigation and 23 batches of the final product of kaolin (10 samples from each batch, i.e. a total of 230 samples were examined) were contaminated with ACPM. Among the la�er, ACPM were isolated from three samples originating from three different batches. ACPM were likely to survive during transport of the kaolin, as a suspension through the pipeline, and during its further processing to the final product (sedimentation, addition of colloid substances, drying and other procedures).

Detection of bovine and human tuberculosis in cattle and other animals in six Central European countries during the years 2000-2004

“…External environments, particularly those contaminated with the members of M. avium complex (Horvathova et al, 1997;Matlova et al, 2003), peat and kaolin used as feed supplements (Trckova et al, 2004;Matlova et al, 2004aMatlova et al, , 2005 and deep litter containing enzymatically digested sawdust (Matlova et al, 2004b) were shown to pose a high risk to animals. After the replacement of sawdust with bran, it was found that bran was also susceptible to contamination with M. avium complex members as feeding bran to pigs caused tuberculous lesions in their lymph nodes (Fischer et al, 2003).…”

Mycobacterial infections in cattle and pigs caused by Mycobacterium aviumcomplex members and atypical mycobacteria in theCzech Republicduring 2000-2004

“…Detection of M. avium complex members prevailed in both animal species: M. a. avium was most commonly isolated from cattle; the sources of this pathogen are particularly free living birds. M. a. hominissuis was mostly isolated from pigs; the source of this pathogen is particularly contaminated external and stable environment: drinking water, feeds, and feed supplements such as peat and kaolin (Engel et al, 1977;Songer et al, 1980;Windsor et al, 1984;Gardner and Hird, 1989;Horvathova et al, 1997;Dürrling et al, 1998;Matlova et al, 2003Matlova et al, , 2004aMatlova et al, , 2005Trckova et al, 2004). Various small terrestrial mammals and invertebrate species are further reservoirs of M. avium complex associated with cattle and pig infections (Fischer et al, 2000(Fischer et al, , 2001(Fischer et al, , 2003a(Fischer et al, ,b, 2004a.…”

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

“…In the first half of the 1990's, the source of MAH was deep bedding, usually composed of sawdust or other wood by-products, fermented by, e.g., ENVISTIM Matlova et al, 2003aMatlova et al, , 2004a. Results from the late 1990's, showed that increased tuberculous lesion formation in pigs was primarily elicited by MAH present in various feed supplements, of which the most important was peat and kaolin ).…”