Isolation of a Mycobacterium microti-like organism from a rock hyrax (Procavia capensis) in a Canadian zoo

A Mycobacterium tuberculosis complex organism was isolated from a zoo resident rock hyrax (Procavia capensis) imported into Canada from South Africa. The strain was identified biochemically as Mycobacterium microti. The spoligotype pattern obtained for this isolate was found to be rare. This represents the first report of isolation and spoligotyping of M. microti in North America.     

Growth and age determination in the hyrax Procavia capensis

Growth and age determination were studied in known age captive hyrax by measuring the animals monthly for three years and killing groups at ages 12,24 and 36 months. Ten body measurements and five skull measurements were used as ageing criteria using multiple regression and a predictive equation. Age (months) = 0,0593 Length + 0,0444 Girth + 0,01117 Headlength - 20,652 was developed for both sexes. Tooth eruption and wear, dental annulli and eyelenses were also investigated and an ageing schedule was developed using tooth eruption and wear. Cementum annulli were shown to be a valid means of ageing up to 36 months and probably up to at least eight years. Eyelenses are not an effective ageing method. Growth in the hyrax is slow and Von Bertalanffy growth coefficients are similar to those in the elephant.     

Surgical castration and the effect on aggression in rock hyrax (Procavia capensis).

Lincoln Park Zoo acquired five intact, male rock hyraxes (Procavia capensis) from three separate institutions to exhibit as a group. The animals were of varying ages at the time of acquisition. During quarantine, all five were surgically castrated via a midline laparotomy technique in an attempt to reduce expected aggression within the group. Recommendations for successful castration, based on these five procedures, include performing the procedure on sexually immature hyraxes or sexually inactive adults, the use of a second surgeon during the procedure, and the use of stainless steel surgical clips for ligation of vessels and spermatic cord. Although combinations of the castrated animals coexisted for longer periods than those documented for other nonrelated male groups, aggression was significant and resulted in the death of one individual. Ultimately, all animals were housed individually.     

Disseminated tuberculosis caused by Mycobacterium avium in a cat

A 5-year-old neutered male Siamese cat was examined by a veterinarian because of a recent decrease in appetite and a large lymph node in the left mandibular area. Clinical findings included fever, icterus, leukopenia, and progressive anemia. Despite various treatments, the cat died approximately 3 weeks after initial examination. The main necropsy findings included necrotizing and granulomatous lymphadenitis of the left mandibular lymph node, multifocal necrotizing hepatitis, and interstitial pneumonia. Acid-fast bacilli were detected in lesions of the mandibular lymph node, liver, lung, spleen, and bone marrow. Mycobacterium avium was isolated from the liver. Avian tuberculosis in cats has been reported rarely.     

No effects of huddling on core body temperature in rock hyrax,Procavia capensis

Huddling is a behavioural energy conservation mechanism that is widely used by many small endotherms at low ambient temperatures. Huddling has many benefits, including decreasing the metabolic cost of maintaining body temperature (T_b), reducing the amount of heat lost to the environment, and increasing the local temperature of the nest. To test the effects of huddling on T_b, 10 rock hyrax, Procavia capensis, were housed in outside cages in four groups, varying from one to four individuals. iButtons® were surgically implanted into each rock hyrax to record their T_b every 15 min from August to November. Despite considerable variations in ambient temperatures, the rock hyrax were found to display some degree of heterothermy by varying their mean T_b from 36.70 to 37.72°C (n = 10) but not allowing it to drop below 33.60°C or rise above 39.67°C. Contrary to what was predicted, rock hyrax did not display any significant effects of huddling on T_b, irrespective of group size.     

An outbreak of tuberculosis in pigs and cattle caused by Mycobacterium africanum.

An outbreak of tuberculosis in pigs and cattle caused by Mycobacterium africanum produced lesions in the pigs similar to those caused by M tuberculosis, M bovis and M avium, with caseation in the lymph nodes of the head and in the jejunal lymph nodes. Bacteriological examination of the dysgonic mycobacteria isolated showed that they were M africanum I. The intradermal tuberculin test was very reliable in pigs, differentiating between mammalian and avian reactions, and the results of the test were in accordance with the lesions found at meat inspection. No clinical signs were observed during the outbreak, and the infection was neither serious nor progressive. There were no lesions in the tuberculin-positive cattle. The source of the infection remains unknown.     

Pancreatic islet fibrosis in rock hyrax (Procavia capensis), Part 2: Pathology, immunohistochemistry, and electron microscopy.

Pancreatic islet fibrosis with varying degrees of islet cell hyperplasia or islet effacement was diagnosed histologically in 19 rock hyraxes (Procavia capensis) from seven zoological parks. Some, but not all, affected hyraxes were from a common lineage. The condition was associated with apparent hyperglycemia in seven and diabetes mellitus in two. Immunohistochemistry revealed hyperplasia of beta, alpha, and delta cells proportional to the degree of the fibrosis. Electron microscopy revealed collagen deposition and fibroplasia within and around the islets. Special stains and electron microscopy were negative for the presence of amyloid. Beta cell depletion was never identified. The condition has morphologic features that resemble islet fibrosis of human infants born to diabetic mothers.     

Annual reproductive pattern in the dassie Procavia capensis

Proximate factors influencing the reproductive pattern and rate in dassies are examined in an area subject to marked seasonal climatic variation. The influence of photoperiod is confirmed with no modifying influence by either temperature or rainfull during the period of the study. Testicular and ovarian activity was related, showing a peak in ovulation and fertilization between the period mid-March and mid-April. Of 49 pregnant females collected between June and December, 83% had either two or three embryos/fetuses. Growth curves for differing litter sizes have been calculated. Failure to increase litter size appears to be related more to a conservative ovulation rate than to ova not fertilized or fetal wastage, although ova loss increased with increasing ovulation rate.     

Relationship between heart rate and metabolism in the hyrax (Procavia Capensis) and guineapig (Cavia porcellus)

The relationship between heart rate and metabolism was investigated in the hyrax Procavia capensis and the guineapig Cavia porcellus. In both animals a positive linear relationship was found described by Vo₂(ml 0₂(g.h)-¹)=0,003157 (HR) + 0,3678 for the hyrax and Vo₂(ml 0₂(g.h)-¹)=0,00757 (HR) -0,4914 in the guineapig. The response to lowered ambient temperature differs between the species, the guineapig increases metabolic rate and maintains body temperature while the hyrax allows body temperature to drop while the increase in metabolic rate is relatively small. It is postulated that this response by the hyrax is an energy conserving strategy.     

Cutaneous lesion caused by Mycobacterium tuberculosis in a dog

A 5-month-old female mixed-breed dog was examined because of nonhealing wounds in the right submandibular region. Treatment with antibiotics and surgical excision was ineffective. Specimens of the right mandibular lymph node and surrounding tissues were submitted for bacteriologic culturing, and Mycobacterium tuberculosis was isolated. The dog was euthanatized. The risk of infection of human beings who associate with dogs that have cutaneous wounds caused by mycobacteria is unknown.     

Naturally occurring tuberculosis caused by Mycobacterium bovis in brushtail possums (Trichosurus vulpecula): II. Pathology

The gross and microscopic lesions due to Mycobacterium bovis infection are described in 73 brushtail possums (Trichosurus vulpeculu) from population studies and from 11 terminally ill possums. Subcutaneous lesions were suppurative in nature, often discharging through sinuses to the exterior. Histologically, the smallest lesions comprised focal aggregations of macrophages with angulated cytoplasmic boundaries occasionally containing acid-fast organisms. Larger lesions were pyogranulomatous, with extensive necrosis, caseation and large numbers of intra- and extra-cellular acid-fast organisms. Few multinucleate giant cells were seen and fibroplasia was rare. Mineralisation was recorded in tuberculous lymph nodes from only two possums. Histological evidence of haematogenous and lymphatic spread was seen in some cases.     

Outbreak of tuberculosis caused by Mycobacterium caprae in a zoological garden

In the autumn of 2004, tuberculosis caused by Mycobacterium caprae occurred in a zoo in Slovenia. A dromedary camel (Camelus dromedarius) was killed after a history of progressive emaciation. Necropsy findings indicated disseminated tuberculosis, which was confirmed by cultivation of M. caprae. Consequently, a tuberculin skin test was performed in all epidemiologically linked animals and another dromedary camel and six bison (Bison bison) were positive and killed. Mycobacterium caprae was isolated from two bison while M. scrofulaceum and Mycobacterium spp. were found in two other bison, respectively. The second dromedary camel was found to be negative for mycobacteria under both microscopic and culture tests. The isolates were investigated with commercial identification kits, IS6110 PCR, IS6110 restriction fragment length polymorphism analysis, spoligotyping and mycobacterial interspersed repetitive units typing. Genotyping results revealed that the dromedary camel and the two bison were infected by the same M. caprae.     

Antibody responses in New World camelids with tuberculosis caused by Mycobacterium microti

Antibody responses in New World camelids (NWC) infected with Mycobacterium microti were studied by two serological methods, multiantigen print immunoassay (MAPIA) and lateral-flow-based rapid test (RT). Serum samples were collected during 2004-2006 from 87 animals including 1 alpaca and 7 llamas with confirmed or suspected M. microti infection, 33 potentially exposed but clinically healthy animals from known infected herds, and 46 control NWC from herds where infection had not been previously diagnosed. The serological assays correctly identified infection status in 97% (MAPIA) or 87% (RT) cases. In three llamas with confirmed M. microti infection and one llama with gross pathology suggestive of disease, for which multiple serum samples collected over time were available, the antibody-based tests showed positive results 1-2 years prior to the onset of clinical signs or being found dead. In MAPIA, MPB83 protein was identified to be an immunodominant serological target antigen recognized in NWC infected with M. microti. With the limited number of animals tested in this study, the serological assays demonstrated the potential for convenient, rapid, and accurate diagnosis of M. microti infection in live llamas and alpacas.     

Chronic tuberculosis caused by Mycobacterium bovis in a domestic donkey in Central Europe

Bovine tuberculosis is a contagious and zoonotic disease of animals and humans. In Europe, the number of reported cases of tuberculosis has decreased. Equidae are relatively rarely infected even in endemic areas. The presented report describes a case of chronic Mycobacterium bovis tuberculosis in a 30-year-old female donkey. The donkey initially presented with persistent lymphadenopathy; however, as the disease progressed, weight loss became apparent. To the authors' knowledge, this is the second confirmed case of tuberculosis in a donkey in Europe.     

An outbreak of tuberculosis by Mycobacterium bovis in coatis (Nasua nasua)

Mycobacterium tuberculosis complex, which includes Mycobacterium bovis, infrequently causes severe or lethal disease in captive wildlife populations. A dead coati from a wildlife triage center showing pulmonary lesions compatible with tuberculosis had raised suspicion of a potential disease caused by mycobacteria species and was further investigated. Four native coatis (Nasua nasua) with suspected mycobacterial infection were sedated, and bronchoalveolar lavages and tuberculin skin tests (TSTs) were performed. All animals tested positive upon TST. Mycobacterial culturing, Ziehl-Neelsen staining, and genetic testing were performed on postmortem samples and the etiologic agent was identified as M. bovis. Molecular genetic identification using a polymerase chain reaction panel was crucial to achieving a definitive diagnosis.     

Naturally occurring tuberculosis caused by Mycobacterium bovis in brushtail possums (Trichosurus vulpecula): III. Routes of infection and excretion

Mycobacterium bovis was cultured from nine of 25 (36%) tracheal washings but not from any of 38 urine and 38 faecal samples from tuberculous possums cross-sectionally sampled from the wild. One of three tracheal washings, one of three urine samples and one of three faecal samples from terminally ill possums were culture-positive. The respiratory route is implicated as the major route of excretion of Mycobacterium bovis from naturally infected possums in horizontal transmission. Tuberculosis was observed in two young possums and was evidence of probable pseudo-vertical transmission via the respiratory route or ingestion of milk. Discharging fistulae were present in 22 of 71 (31%) cross-sectionally sampled tuberculous possums and were associated with relatively advanced disease. Although the frequent involvement of superficial lymphocentres in early stage disease could not be explained satisfactorily, the respiratory route was implicated as the main route of infection from indirect evidence.     

Disseminated Mycobacterium celatum (type 3) infection in a domestic ferret (Mustela putorius furo)

A 4-year-old male ferret (Mustela putoriusfuro) had a 6-month history of weight loss and gradual development of depression and coughing. Necropsy findings included pale gray tissue around the distal trachea, multiple nodules in the lungs, a single nodule in the stomach wall, gray foci in the liver, and enlarged lymph nodes. Histologic examination revealed multifocal to coalescing granulomatous inflammation in the trachea, lungs, stomach, liver, and lymph nodes, with acid-fast bacteria in epithelioid cells and macrophages. The acid-fast bacteria were identified as Mycobacterium celatum (type 3) using DNA sequence analysis of the 16S ribosomal DNA gene. M. celatum is a recently described mycobacterium isolated mainly from immunocompromised humans. This is the first report of M. celatum infection in an animal.     

Reproduction in the Rock Hyrax (Procavia Capensis)

Irradiation has adverse effects on reproductive aspects such as spermatogenic cell population and cell malformation, leading to reduced sperm count and non-viable spermatozoa. This has overshadowed possible effects of radiation exposure on biochemical environment throughout the epididymis and the viability of spermatozoa that appeared morphologically normal. The effects of radiation exposure on sperm quality were evaluated through mating trials and assessment of the cauda epididymal sperm motility. Sprague Dawley rats with body mass of 300–400 g were selected at random. Two experimental groups received acute ⁶°Co γ-radiation doses of 3.5 and 6.0 Gy, respectively. Data were collected 2, 7, 14, 21, 28 and 35 days post-irradiation. Each male was housed with a non-irradiated super-ovulated female during mating trials. Cauda epididymal sperm motility was assessed with the CASMA. Hormone analyses were carried through chemiluminescence diagnostic tests to determine the endocrine status. Results suggest that irradiation causes an overproduction of estrogens, which suppresses the hypothalamic-pituitary axis and inhibits LH and FSH secretions. Both LH and FSH deficiencies have negative effects on the testicular index and local reproductive hormones. Elevated estrogen levels influenced the epididymal internal milieu negatively, resulting in rigid, flagella bending sperm tail, impaired progressive movement of the spermatozoa and hence infertility