Evidence of Mycobacterium avium subsp. paratuberculosis infection in Dutch farmed red deer

Paratuberculosis is a chronic disease in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). Most economic losses due to MAP occur in the dairy industry. However, the infection is not restricted to cattle, but also occurs in other ruminants, such as sheep, goat, and deer. Although deer are of minimal economic importance in The Netherlands, they may constitute a source of infection for the dairy industry. This pilot study was conducted to estimate the prevalence of Johne's disease in farmed red deer in The Netherlands. Serum and faecal samples were collected from 140 animals, originating from 8 different farms. Four of the farms had animals that tested positive for Johne's disease. The within-herd MAP seroprevalence varied between 4.8% and 21.2%. In conclusion, this pilot study provides evidence of MAP infection in the Dutch farmed deer population, and thus there might be a risk of MAP transmission between farmed red deer and dairy cattle.     

Mycobacterium bovis infection in a captive herd of Sika deer.

Infection with Mycobacterium bovis was diagnosed in a small privately owned herd of Sika deer. After postmortem examination of a deer with progressive pulmonary disease, diagnosis of infection with M bovis was confirmed by bacteriologic culture. The 2 remaining deer in this herd were euthanatized, necropsied, and confirmed to be infected with M bovis. Three cats in contact with the deer were also euthanatized and necropsied. One of these cats had lesions suggestive of mycobacterial infection in the colon and mesenteric lymph nodes. Infection of this cat with M bovis was not confirmed by bacterial culture. Mycobacteriosis, infrequently encountered in clinical veterinary practice, may be confused with disease caused by other infective agents or neoplasia. The zoonotic potential of these bacteria and a recent increase in human tuberculosis warrants continued surveillance of companion and food animal populations for mycobacterial infection.     

Mycobacterium avium infection in a dog

A 5-year old, spayed, mongrel was presented with intractable diarrhoea. Histopathologic examination of biopsy specimens taken during exploratory laparotomy revealed acid-fast organisms in the spleen, caecum, and colon. The dog was subsequently destroyed. At post-mortem, lesions were also observed in the liver and lymph nodes. Mycobacterium avium was cultured from splenic tissue. Infection of dogs with this organism is rare and the clinical picture described unusual.     

Characterization by restriction endonuclease analysis and seroagglutination of strains of Mycobacterium avium and Mycobacterium intracellulare obtained from farmed deer.

Restriction endonuclease analysis and seroagglutination were used to characterize strains of Mycobacterium avium and Mycobacterium intracellulare (collectively, MAI) recovered from 1 local herd and 2 imported shipments of red deer (Cervus elaphus) that developed sensitization to bovine tuberculin during skin testing. A total of 31 MAI strains were isolated from lymph node pools (head, thorax, abdomen, and peripheral regions) of 21 of 29 local deer. Similarly, 15 MAI strains were isolated from the lymph node pools of 12 deer from the 2 imported shipments. Mycobacterial strains were isolated from more than 1 of the lymph node pools of 9 local and 2 imported deer. Most of the strains (59% from local deer, 46% from imported deer) were recovered from the lymph nodes of the head region. After restriction endonuclease analysis of these isolates using the enzymes Bcl I, BstEII, and Pvu II, 26 of the strains from the local herd were separated into 3 groups, each consisting of strains with indistinguishable or closely related patterns. Seroagglutination results indicated that the first of these groups contained strains belonging to serotype 1, the second group contained strains belonging to serotype 8; and the third group of strains belonged to serotype 3 and 9. The 5 remaining strains from the local herd had unrelated restriction patterns. One of these belonged to serotype 3, whereas the remaining 4 could not be serotyped. Restriction analysis of the 15 strains from the imported deer identified 2 groups. Seroagglutination results indicated that 1 group contained strains belonging to serotype 2 and the other group contained strains belonging to serotype 8.(ABSTRACT TRUNCATED AT 250 WORDS)     

Disseminated Mycobacterium avium infection in a cat

A domestic shorthair cat was presented for lethargy and ataxia. Clinical findings included an abdominal mass, lumbosacral pain, ataxia. Aspirates from the liver and lymph nodes revealed intracellular, negative-staining rods. Treatment for presumptive mycobacterium infection was unsuccessful and the cat was euthanized. Disseminated Mycobacterium avium was confirmed on culture.     

Association between cattle herd Mycobacterium avium subsp. paratuberculosis (MAP) infection and infection of a hare population

Paratuberculosis has long been considered a disease of domestic and wild ruminants only. The known host range of Mycobacterium avium subsp. paratuberculosis (MAP) was recently extended to include non-ruminant wildlife species believed to be exposed to spillover of MAP from infected domestic cattle herds. The aim of the present study was to assess the association between cattle herd MAP infection pressure level and the infection level of a hare population in two dairy farms of southern Chile. Fifty hares from a herd A and 42 hares from herd B were captured and sampled for MAP culture. The results showed a statistically significant association between the cattle herds’ infection prevalence and the hare infection prevalence.     

Description of the infection status in a Norwegian cattle herd naturally infected by Mycobacterium avium subsp. paratuberculosis

The Norwegian surveillance and control programme for paratuberculosis revealed 8 seroreactors in a single dairy cattle herd that had no clinical signs of Mycobacterium avium subsp. paratuberculosis (M. a. paratuberculosis) infection. Paratuberculosis had been a clinical problem in goats several years previously in this herd. All 45 cattle were culled and a thorough investigation of the infection status was conducted by the use of interferon-gamma (IFN-gamma) immunoassay, measurement of antibodies, and pathological and bacteriological examination. In the IFN-gamma immunoassay, 9 animals gave positive results, and 13 were weakly positive, while 19 animals were negative. In the serological test, 10 animals showed positive reactions, and 5 were doubtful, while 30 animals gave negative reactions. There appeared to be a weak trend toward younger animals having raised IFN-gamma and older animals having raised serological tests. Histopathological lesions compatible with paratuberculosis were diagnosed in 4 animals aged between 4 and 9 years. Three of these animals had positive serological reaction and one animal gave also positive results in the IFN-gamma immunoassay. Infection was confirmed by isolation of M. a. paratuberculosis from 2 of these 4 animals. One single bacterial isolate examined by restriction fragment length polymorphism (RFLP) had the same profile, B-C1, as a strain that had been isolated from a goat at the same farm several years previously. Despite many animals being positive in one or both of the immunological tests, indicative of a heavily infected herd, none of the animals showed clinical signs and only one cow was shown to be shedding bacteria. A cross-reaction with other mycobacteria might have caused some of the immunoreactions in these animals. It is also possible that the Norwegian red cattle breed is resistant to clinical infection with M. a. paratuberculosis.     

Disseminated Mycobacterium avium subspecies infection in a cat

An 18-month-old neutered male domestic shorthair cat, domiciled in the southwest of France, was first presented having suffered for a few days from dysorexia and vomiting. Abdominal palpation revealed lymph node enlargement. Cytological examinations of a fine needle aspirate demonstrated granulomatous inflammation with many non-staining elements consistent with mycobacteria. Diagnosis was confirmed by culture and polymerase chain reaction and Mycobacterium avium subspecies was isolated. Treatment was initiated with marbofloxacin, rifampicin and cefoxitin. There was a rapid clinical improvement. The cat suddenly died 2 months later. The main hypothesis is the administration of an inappropriate combination therapy that leads to the development of mycobacterial resistance. A volvulus and acute peritonitis secondary to the significant enlargement of a mesenteric lymph node were present at necropsy. Histopathological analysis of mesenteric lymph node, liver and spleen revealed multicentric granulomatous and severely necrotic lesions with numerous Ziehl-Neelsen positive intracytoplasmic elements.     

Mycobacterium avium subsp. paratuberculosis infection in wildlife on three deer farms with a history of Johne's disease

Abstract

AIM: To determine the prevalence of Mycobacterium avium subsp. paratuberculosis (Map) infection in wildlife, in pastoral landscapes with a recent history of clinical Johne's disease in livestock.

METHODS: A total of 449 wild mammals and birds from three farms in the South Island of New Zealand with recent histories of clinical Johne's disease in their deer herds were trapped and examined for gross pathological changes in the gastrointestinal tract. Additionally, individual mesenteric lymph nodes from 380 mammals, and segments of gastrointestinal tract from 32 birds were excised, homogenised and cultured for viable Map bacilli. The prevalence of Map infection was then calculated for the various species. Faecal samples from those mammals which had culture-positive tissues were further cultured for the presence of Map.

RESULTS: Gross pathological changes were identified in the gastrointestinal tract of four brushtail possums, one cat, six ferrets, 12 hares, six hedgehogs, three rabbits, one stoat, and one paradise shelduck. Infection with Map in the gastrointestinal tract was confirmed in only three of these cases, one each of brushtail possums, hares and hedgehogs. In contrast, Map infection in the absence of gross pathological changes was frequently recorded in enteric tract tissues of mammals and birds. Among mammals, Map infection was recorded in 18/73 (25%) brushtail possums, 4/23 (17%) cats, 15/42 (36%) hedgehogs and 29/113 (26%) rabbits. Among birds, intestinal tract tissue Map infection was recorded in 3/17 (18%) paradise shelducks. Among 64 of the 74 mammals which had Map culture-positive tissues, 38% (n=5) of hedgehogs and 11% (n=3) of rabbits also had culture-positive faecal samples.

CONCLUSIONS: This study is the first to identify that Map infection can be prevalent in wildlife in New Zealand. There was a high prevalence of Map infection among both scavenging and grazing wild animals. Both mammals and birds are capable of harbouring viable Map organisms in their gastrointestinal tract; further, viable Map was excreted into the environment via faeces by hedgehogs and rabbits.

CLINICAL RELEVANCE: Previous studies overseas have postulated a role of wildlife as reservoirs of Map infection and possible vectors of Johne's disease to livestock. Here, brushtail possums, hedgehogs and rabbits and in particular were identified as potential wildlife hosts for Map infection in NewZealand. This suggests that several wildlife species could contribute to the persistence of Map infection within a wildlife/livestock complex, and potentially, perhaps more importantly, to the spread of infection between farms.     

Use of a polymerase chain reaction to subtype Mycobacterium avium subspecies paratuberculosis, an increasingly important pathogen from farmed deer in New Zealand

AIMS: To review the number of microbiologically-confirmed cases of Johne's disease in farmed deer since 2000, and determine the prevalence of the bovine and ovine subtypes of Mycobacterium avium subsp paratuberculosis (M. paratuberculosis), using a highly specific polymerase chain reaction (PCR) test on samples from infected herds. METHODS: The number of cases of M. paratuberculosis in farmed deer identified by culture or IS900 PCR was documented. A highly specific PCR test was applied to subtype M. paratuberculosis from BACTEC 12B cultures selected on the basis of one culture per deer herd, to give a wide coverage of herds in New Zealand. RESULTS: From January 2001 to October 2005, M. paratuberculosis was isolated from 1,141 farmed deer, and has now been identified by microbiological testing in over 600 deer herds in New Zealand. The bovine subtype of M. paratuberculosis was shown by a highly specific PCR test to be present in 91/95 herds examined; the ovine subtype was found in the remaining four herds. CONCLUSIONS: Since 2000, there has been a substantial increase in both the number of microbiologically-confirmed cases of Johne's disease in farmed deer and the number of infected herds. Johne's disease is now widespread and common in deer herds throughout New Zealand. Whilst the bovine subtype of M. paratuberculosis predominates in deer herds in New Zealand in which Johne's disease has been confirmed, the occasional finding of the ovine subtype highlights the need to consider both sheep and cattle as potential sources of infection for farmed deer.     

Disseminated Mycobacterium avium infection in a dog with chronic diarrhoea

A 3-year-old Maltese-cross dog presented with a 4-month history of chronic diarrhoea and inappetence. Poorly regenerative anaemia, leukocytosis and hypoproteinaemia were evident on several occasions. Biopsies of stomach, duodenum and colon revealed marked infiltration of mucosae by macrophages containing many acid-fast bacilli. Similar organisms were numerous in a faecal smear. Melaena, hematochezia and severe abdominal pain developed and were unresponsive to therapy. Following euthanasia and necropsy, histiocytic cells containing acid-fast bacilli were found throughout the gastrointestinal tract, mesenteric and peripheral lymph nodes, spleen, liver, kidney and lungs. The organism was identified as Mycobacterium avium by bacterial culture and polymerase chain reaction testing.     

Dictyocaulus infection in farmed red deer (Cervus elaphus)

Post mortem examination of red deer calves on a deer farm situated on hill ground in north-east Scotland revealed infection by a lungworm morphologically similar to Dictyocaulus viviparus. Trials were conducted to monitor the natural development of D viviparus infection in red deer, to investigate the value of a commercial lungworm vaccine and to evaluate methods of treating clinical cases. The findings indicate that the syndrome may be less apparent in red deer than it is in cattle, protection might be gained by vaccination and that housing and medication provide useful therapy. The extent of clinical disease is likely to depend on the general health, bodily condition and nutritional status of the animals versus the weight of infection acquired from the pasture. However, various factors can affect both sides in this confrontation.