Granulomatous lesions in lymph nodes of slaughter pigs bacteriologically negative for Mycobacterium avium subsp. avium and positive for Rhodococcus equi
Loading...
Date
2007
Journal Title
Journal ISSN
Volume Title
Publisher
Veterinary microbiology
Abstract
The prevalence of granulomatous lesions in lymph nodes of pigs was studied. From January till August 2004 in two
slaughterhouses in The Netherlands 2,116,536 pigs were examined for the presence of granulomatous lesions in the submaxillary
lymph nodes. In 15,900 (0.75%) of these pigs, lesions could be detected. Nine farms with the highest incidence of
lesions were selected for a more detailed pathological and bacteriological examination. On these farms, the prevalence of lesions
in sub-maxillary lymph nodes ranged from 2.3 to 5.7% with a mean of 3.0%. From 1276 pigs that were sampled, 98 (7.7%)
displayed granulomatous lesions in the sub-maxillary lymph nodes and one (0.1%) pig showed lesions in its mesenteric lymph
node. Mycobacterium avium subsp. avium (MAA) could not be isolated from the lymph nodes of the 99 pigs with lesions and
from a selection of lymph nodes (n = 61) of pigs without lesions. Rhodococcus equi was isolated from 44 out of 98 (44.9%) of
the sub-maxillary lymph nodes with granulomatous lesions and from two mesenteric lymph nodes without lesions. A
comparison of former studies and the current results indicate that the prevalence of MAA infections in slaughter pigs has
strongly decreased over the last decade, whereas R. equi is highly prevalent. The high incidence of granulomatous lesions
associated with the bacteriological presence of R. equi could be considered as a serious cause of misdiagnosis ofMAAinfections
in cases where meat inspection is carried out by inspection for granulomatous changes of lymph nodes only.
Description
Keywords
Mycobacterium avium, Swine mycobacteriosis, Lymphadenitis, Bacteria, Diagnosis, Rhodococcus equi
Citation
Komijn, R. E., Wisselink, H. J., Rijsman, V. M., Stockhofe-Zurwieden, N., Bakker, D., van Zijderveld, F. G., ... & Urlings, B. A. (2007). Granulomatous lesions in lymph nodes of slaughter pigs bacteriologically negative for Mycobacterium avium subsp. avium and positive for Rhodococcus equi. Veterinary microbiology, 120(3-4), 352-357. doi:10.1016/j.vetmic.2006.10.031