Prevalence ofMycobacterium aviumin Slaughter Pigs in The Netherlands and Comparison of IS1245Restriction Fragment Length Polymorphism Patterns of Porcine and Human Isolates

Abstract

A significant increase in the incidence of caseous lesions in the lymph nodes of slaughter pigs prompted a large-scale investigation in five slaughterhouses in The Netherlands. In total, 158,763 pigs from 2,899 groups underwent gross examination. At least one pig with caseous lesions in the submaxillary and/or mesenteric lymph nodes was observed in each of 154 of the 2,899 groups examined (5%). In total, 856 pigs (0.5%) were affected. As many as five pigs in each of 141 of the 154 positive groups (91.5%) had lymph node lesions. Greater numbers of pigs with affected lymph nodes were found in 13 groups (8.5%). Four pigs had lesions in the kidneys, liver, or spleen. Acid-fast bacteria were detected by microscopic examination of 121 of 292 Ziehl-Neelsen-stained smears of caseous lesions (41%). In a follow-up study, Mycobacterium avium complex (MAC) bacteria were isolated from 219 of 402 affected lymph nodes (54.2%). Ninety-one of the isolated strains were analyzed by restriction fragment length polymorphism (RFLP) typing with insertion sequence IS1245 as a probe. All but 1 of these 91 strains contained IS1245 DNA, indicating that pigs in The Netherlands carried almost exclusively M. avium bacteria and no other bacteria of MAC. Only one pig isolate exhibited the bird-type RFLP pattern. MAC isolates from 191 human patients in The Netherlands in 1996 were also typed by RFLP analysis. Computer-assisted analysis showed that the RFLP patterns of 61% of the human isolates and 59% of the porcine isolates were at least 75% similar to the RFLP patterns of the other group of strains. This indicates that pigs may be an important vehicle for M. avium infections in humans or that pigs and humans share common sources of infection.

Molecular epidemiology of tuberculosis and other mycobacterial infections: main methodologies and achievements

“…Bird isolates exhibited a specific three‐band IS 1245 RFLP pattern. In the Netherlands, examination of a broad spectrum of M. avium complex isolates from different sources confirmed this picture [263, 265]. Almost all 90 M. avium ssp.…”

“…The M. avium complex comprises a heterogeneous group of slow‐growing bacteria, ubiquitous in nature. It is still uncertain how humans contract M. avium complex infections, although some studies describe the isolation of these bacteria from tap water [257–259], soil [259], cheese [260], cigarettes [261], and animals such as birds and pigs [262–265].…”

“…Almost all 90 M. avium ssp. avium strains isolated from lymph nodes of slaughtered pigs showed multibanded IS 1245 RFLP patterns with a high degree of similarity with a large proportion of the multibanded IS 1245 RFLP patterns of isolates from humans [265, 284]. In a study in Denmark, samples of peat to be used as potting soil were also found to contain viable M. avium ssp.…”

Applying the One Health Concept to Mycobacterial Research – Overcoming Parochialism

“…Food‐producing animals and pet animals act as reservoir hosts for a variety of NTM species, many with documented zoonotic potential (Katoch, ; Bennett et al., ; Greene, ; Schrenzel, ; Woerde et al., ). Many NTM are virulent in animals, but their human disease potential is poorly understood (Bono et al., ; Komijn et al., ; Hoefsloot et al., ; Richter and Saviola, ). NTM infections in humans from tuberculosis‐endemic areas are often misdiagnosed and result in inappropriate treatment and poor clinical outcomes (Maiga et al., ).…”

Technical specifications on harmonised epidemiological indicators for public health hazards to be covered by meat inspection of swine

“…avium (MAA) is a potential zoonotic pathogen that belongs to MAC. Pigs may be a reservoir of MAA, although other sources have not been excluded (Komijn et al, 1999).…”