Mycobacteriosis outbreak caused by Mycobacterium avium subsp. avium detected through meat inspection in five porcine fattening farms

Abstract

AnimAl tuberculosis (TB), caused by Mycobacterium TB complex (mTBC) species, is a chronic zoonotic disease mainly affecting cattle. However, it can also cause disease in humans and a wide range of other animal species (OiE 2009). The wild boar (Sus scrofa) is the third animal species, followed by cattle and goats, in number of mTBC isolates in Spain (Rodriguez-Campos and others 2012). Thus, it is considered to be the main wild reservoir of TB (naranjo and others 2008, Garcia-Bocanegra and others 2012). The domestic pig (Sus scrofa domestica) accounts for 1 per cent of Spanish mTBC isolates from animals in the period 1996-2011 (Rodriguez-Campos and others 2012). Recent TB outbreaks in domestic pigs due to mTBC have also been reported in italy (Di marco and others 2012). There are, however, other opportunistic mycobacteria that can cause TB-like lesions in swine, indistinguishable from those caused by mTBC. Mycobacterium avium complex (mAC) comprises a number of non-zoonotic pathogenic bacterial species with various degrees of pathogenicity and host preference (Álvarez and others 2011). M avium is subdivided in four subspecies: M avium subsp. avium (mAA), M avium subsp. silvaticum, M avium subsp. paratuberculosis (mAP), and M avium subsp. hominisuis (mAH). mAA is known to cause generalised granulomatous lesions in poultry and wild birds; mAP is the causative agent of Johne's disease in ruminants, while pigs are the primary animal host for mAH (Thorel and others 2001, mijs and others 2002, Wellenberg and others 2010, Agdestein and others 2011, Álvarez and others 2011). However, pigs may also be infected by mAA, displaying lesions indistinguishable from those caused by mycobacteria belonging to the mTBC (Komijn and others 1999). Therefore, when

Epidemiology of Pig Tuberculosis in Argentina

“…MAC species were isolated in 9.1% (18/191) of TBL samples, similar to previous research in pigs in Argentina (7). In contrast, the percentage of MAC obtained from TBL samples was higher in developed countries compared to the results obtained in the present study (8,44,45). Such finding might be related to intensive farming and high biosecurity measures employed in developed countries, where MAC outbreaks are generally associated with contaminated feed or bedding, rather than interaction with domestic animals or wildlife (46).…”

“…In contrast, the percentage of MAC obtained from TBL samples was higher in developed countries compared to the results obtained in the present study ( 8 , 44 , 45 ). Such finding might be related to intensive farming and high biosecurity measures employed in developed countries, where MAC outbreaks are generally associated with contaminated feed or bedding, rather than interaction with domestic animals or wildlife ( 46 ). The number of negative samples for both MTC and MAC in this study could be associated with non-infectious causes other non-pathogenic mycobacteria, or different infectious agents ( 44 ).…”

Six-Year Follow-up of Slaughterhouse Surveillance (2008–2013)

“…A final diagnosis of mycobacteriosis due to Mycobacterium avium subsp avium was attained. 23 Interestingly, pigs are highly susceptible to M. avium complex infections, displaying lesions indistinguishable from those caused by MTBC. 6 Therefore, a rapid diagnosis becomes crucial in terms of occupational hazards.…”

Serological Follow-up of Tuberculosis in a Wild Boar Population in Contact with Infected Cattle

“…It is well known that M. avium complex spp. infection in swine can induce TBLL indistinguishable from MTBC infection (Muñoz‐Mendoza et al., ; Pérez de Val et al., ). Therefore, even though MPB83 antigen is specific of MTBC, other mycobacteria express homologous cross‐reactive antigens that may elicit humoral responses in infected hosts, compromising TB diagnosis (Waters et al., ; Marassi et al., ).…”