Pathological Evaluation of Paratuberculosis in Naturally Infected Cattle

Abstract

h ac a, N .Y . Ab stract. T hirty-two of 51 catt le infected with Mycobacterium paratub ercu los is ha dchro nic e nte riti s , chro nic lymp hangiti s o r me senter ic lym p hade no p a th y , or a ll three , at sla ug hte r. G ran ulom a tous inflammato ry le sion s were mi ld to a d va nce d a nd predominant ly invol ve d t he dista l sma ll in testi ne . Re ctal invo lveme nt wa s see n on ly in five ca tt le . Fourteen ha d microgran ulom as in the live r . There were t hree cytologica l form s o f macrop hage s : hist ioc ytic , po lygon al a nd e p it he lio id . T he la tt e r two types ha d engulfed mode rate num be rs of acid-fast b aci lli. T he h ist io cytic m acro p hages usua lly were packed with ac id-fast bacilli. Except in th e live r a nd occasiona lly its node s , remote le sio ns of para tubercu lo sis were no t found in ot her orga ns. One animal had endocardial a nd ao rt ic ca lcification s. Most catt le with sig ns of diarr hea ha d glo bule leu ko cytes in or around mye nteric ganglio n ce lls . T he thymus of 3-to 8-year-o ld catt le wit h clinical signs freq uent ly had mi ld to a d va nce d involut ion . T he th ym us of sim ila r ly aged infected a n ima ls without clin ica l signs, a nd of pa ratu be rc ulos is-nega tive animals , ha d no t involuted .Parat ube rc ulosis (Jo hne's disease ) , a chro nic infectio us disease of do mes ticated and wild rum inant s, has been recognized t hro ug ho ut the world since it first was descri bed in 1895 . Its ca usat ive agen t is Mycobacterium paratuberculosis, a faculta tive intracellul a r acid-fast bacte rium . T he macroscopic a nd hist ol ogic lesion s of pa ratubercul o sis basically remain confined to th e in tes ti ne , mesenteric and ileocaecall ymph nodes [7] . A lt ho ug h M . paratuberculosis has been cultured from a variety o f othe r orga ns , microscopic lesio ns have been found o nly in th e live r [1 2] . M . paratuberculosis is ass umed to sprea d prim a rily via circulati ng macrophages. In the liver th ese macro ph ages ma y become foca lly tra pped in sin usoi ds a nd with lymphocytes ma y give rise to micr ogr anulo mas .Early inves tiga tors of par atubercul osis e mp has ize d its similarity to leprosy [3 , 5 , 10] . Bo th diseases are ca use d by acid-fas t bacte ria th at a re diff icult to culture a nd hav e lon g gro wth periods . T he inflamm at o ry response in both d iseases is similar. Despite invo lveme nt of differe nt orga n syste ms, th e micro scopic lesion s a re dom inated by macr oph ages an d Lan gh an s' gia nt ce lls .Le prosy has bee n classified int o two po la r fo rms -tube rcul o id an d leprom at ou s 19 6

Histopathological Classification of Lesions Observed in Natural Cases of Paratuberculosis in Free-ranging Fallow Deer (Dama dama)

“…Multifocal lesions, which occur mainly in subclinically infected animals, may represent progression of the infection after failure of the immune response. The diffuse multibacillary form has been widely reported by different authors (Buergelt et al, 1978;Huda and Jensen, 2003). In the present study this type of lesion was associated with a severe thickening of the intestinal wall, as described previously in cattle and sheep (Pe´rez et al, 1996;Gonza´lez et al, 2005).…”

“…Paratuberculosis is well studied in domestic ruminants, but there are relatively few reports in free-ranging deer (Jessup and Williams, 1999;Pavlik et al, 2000;Alvarez et al, 2005), infection in such animals having been first diagnosed in five free-ranging fallow deer (Dama dama) in Spain in 1997 (Marco et al, 2002). Classification of lesions has been described in sheep (Stamp and Watt, 1954;Carrigan and Seaman, 1990;Pe´rez et al, 1996), goats (Paliwal et al, 1985;Corpa et al, 2000) and cattle (Buergelt et al, 1978;Gonza´lez et al, 2005). In ovine paratuberculosis, Pe´rez et al (1996) described small ''tuberculoid'' granulomas in the ileocaecal lymphoid tissue (Peyer's patches).…”

Paratuberculosis or avian tuberculosis in red deer with chronic diarrhea?

“…First of all, clinical signs and lesions observed in deer with the multibacillary form of the disease match the lesion descriptions for cattle and small ruminants in multibacillary cases (Buergelt et al 1978, Clarke 1997, Huda and Jensen 2003, Gonzalez et al 2005, Mackintosh et al 2007. However, lesions in the large intestine with diffuse inflammatory infiltration and AFB was observed as well as multifocal granulomas in liver, probably due to more susceptibility of the deer or may be a more pathogenic Map strain.…”

Mycobacterium Avium Subspecies Paratuberculosis and Mycobacterium Avium Subsp. Avium Infections in a Tule Elk (Cervus Elaphus Nannodes) Herd

“…The presence of macrophages and/or multinucleated giant cells in tissue sections in the absence of positive culture results may represent reactions to other infectious agents or antigens or may simply reflect the insensitivity of histopathology as a test for subclinical mycobacterial infections. Microgranulomas have been associated with MAP infections in cattle and bison (Bison bison) even in the absence of acidfast bacteria (Buergelt et al, 1978(Buergelt et al, , 2000, as well as MAA infection in clinically normal farmed red deer (De Lisle et al, 1995).…”