Detection of mycobacterial infection in non-human primates using the Xpert MTB/RIF molecular assay.

Tuberculosis is a major public health concern, and diagnostic strategies applied to animal populations are scarce. As part of ongoing efforts to control tuberculosis dissemination at our animal facility, two non-human primates (NHP, Saimiri sciureus) presenting cutaneous lesions were examined for mycobacterial infection. Both animals tested positive for acid-fast bacilli and Mycobacterium tuberculosis using a molecular assay (IS6110 PCR). Animals were euthanized and several samples were tested for M. tuberculosis using the Xpert MTB/RIF assay. Many samples were positive for M. tuberculosis and rifampicin resistance, and some produced mycobacterial growth. Oral swabs from cage mates were then tested with Xpert MTB/RIF, and the majority tested positive for M. tuberculosis and rifampicin resistance, and produced growth in culture. To our knowledge, this is the first report of multidrug-resistant mycobacterial infection in NHP. Additionally, our data shows that the Xpert MTB/RIF assay can be useful as a screening tool for tuberculosis infection in NHP.

Mycobacterial dermatitis.

Mycobacterial skin disease in cats associated with atypical mycobacteria is an uncommon disease in small animal practice, and the disease is rarely encountered in dogs. A mycobacterial etiology should be considered in cases of chronic nodular dermatitis, draining tracts, and panniculitis. Cats and dogs affected with atypical mycobacterial infections are usually otherwise healthy, and systemic illness is unusual. In most cases, a diagnosis is made based on histopathological findings and growth of a causative organism. Group IV atypical mycobacteria can usually be grown following submission of affected tissue. Treatment should be based on antibiotic sensitivity test results. Treatment is prolonged and is unsuccessful in many cases. In cases of feline leprosy and canine leproid granuloma syndrome, organisms are difficult if not impossible to grow, and clinical and histopathological findings should be used to make a diagnosis. Spontaneous resolution of disease has been reported in atypical mycobacteriosis, feline leprosy, and canine leproid granuloma syndrome.

Inflammatory pseudotumor in a cat with cutaneous mycobacteriosis.

A 5-year-old, castrated male, domestic Shorthair Cat had an ulcerated mass with fistulous tracts on the left hind paw. Homogeneous tan tissue diffusely infiltrated the dermis and subcutis of the paw and extended proximally so that, short of amputation, complete excision was not feasible. Biopsy specimens consisted of granulation tissue with marked proliferation of spindle cells. Neutrophils and histiocytic cells were scattered among the spindle cells. The histiocytic cells had abundant foamy or vacuolated cytoplasm, but features of granulomatous inflammation, such as epithelioid macrophages or granuloma formation, were not observed. The initial impression was inflammatory granulation tissue, but the degree of fibroplasia prompted inclusion of fibrosarcoma in the differential diagnosis. Cutaneous mycobacteriosis was diagnosed when numerous acid-fast bacteria were identified with Kinyoun's stain; Mycobacterium avium was subsequently cultured. The cat was euthanatized because of lack of response to enrofloxacin therapy. At necropsy, lesions were localized to the hind limb. Not only is mycobacteriosis an uncommon cause of cutaneous masses in cats, but this case was unusual because of the lack of granuloma formation and the similarity of the mass to a spindle cell tumor.

Subcutaneous granuloma caused by Mycobacterium avium complex infection in a cat.

A localised subcutaneous swelling developed on the nasal bridge of a cat receiving chemotherapy for alimentary tract lymphosarcoma. Cytological and histological examination of representative samples of the lesion demonstrated pyogranulomatous inflammation and abundant acid-fast bacilli. A Mycobacterium sp was cultured from tissue excised from the lesion. Extensive testing at three reference laboratories indicated the strain was a member of the Mycobacterium avium complex. The infection was treated successfully by cytoreductive surgery and a 6 weeks course of orally administered clofazimine.

Zoonotic dermatoses of dogs and cats.

Zoonotic dermatoses in dogs and cats are an important cause of skin disease in human beings. In addition, human dermatoses may occasionally be transmitted to dogs and cats. The veterinarian and the physician form a critical "health care team" in the proper management of these disorders.

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.

Lesions and tuberculin sensitivity in calves inoculated with group III mycobacterial isolates from swine, pen soil, and cattle feed.

FIFTEEN calves, 7 to 11 months of age, were inoculated intradermally with group III mycobacteria ---6 isolates from swine, 1 isolate from cattle feed, and 2 isolates from soil of swine farrowing pens. Calves were tuberculin tested at 50 days and killed approximately 60 days after inoculation. Only 1 of the cultures, that of porcine origin (93c-0), produced any lesions. There were a caseo-calcareous granuloma 3mm in diameter in the regional lymph node (left prescapular) and a granuloma at the skin inoculation site. None of the 5 calves inoculated with soil- or feed-origin mycobacteria had any lesions. Three of the calves inoculated with porcine origin group III mycobacteria had suspicious or positive caudal fold reactions. Two of these had granulomas at the skin-inoculation sites and one had no lesions. The calf having lymph node and skin-inoculation site granulomas was negative. The 5 calves inoculated with feed- or soil-origin mycobacteria had negative caudal fold tuberculin tests.

Comparison of the specificity of human and bovine tuberculin PPD for testing cattle. 2. South-eastern England.

A tuberculin testing trial was carried out in eight counties of south-eastern England to compare the specificity for bovine tuberculosis of Weybridge human PPD with that of Rotterdam bovine PPD. The matching of these two tuberculins for potency in naturally infected cattle had already been established, the bovine PPD being approximately one-and-a-half times more potent than the human PPD per unit of weight. In 1110 cattle in 25 herds with histories of long-standing freedom from tuberculosis and in which non-specific tuberculin sensitivity was present, cross reactions were less to the bovine PPD than to the human PPD, showing that in the environment of this trial the bovine PPD was more specific than the human PPD. Induration diameter was a satisfactory alternative to skin thickening as a measure of tuberculin reactions in cattle under field conditions. Due to the steep slope of the dose-response curves of the avian PPD in the different groups of non-tuberculous cattle, the discriminating power of the comparative test, using avian and mammalian tuberculins, was less at lower doses of tuberculin. Concentrations of 1-0 mg per ml of bovine PPD and 0-5 mg per ml of avian PPD are recommended for use in a comparative tuberculin test.

Comparison of the specificity of human and bovine tuberculin PPF for testing cattle. 3. National trial in Great Britain.

A field trial on a country-wide basis was undertaken to compare the specificity for bovine tuberculosis of single and comparative tuberculin tests in cattle using either Weybridge human or Weybridge bovine PPD. The tests were made on 10,305 cattle in 179 herds distributed throughout all regions of England, Scotland and Wales. Results showed that a comparative tuberculin test using avian PPD with either human or bovine PPD had a much higher efficiency than a single injection of mammalian tuberculin in the neck of cattle, and confirmed that a comparative test is still essential in the British environment. Weybridge bovine PPD gave significantly better discrimination between tuberculous and non-tuberculous cattle than Weybridge human PPD when used together with avian PPD in a comparative tuberculin test. The diameter of induration gave an absolute measure of the extent of oedema, if present, and induration diameter used in conjunction with skin thickening increased the sensitivity and specificity of the test. Rules of interpretation were developed and are presented for an intradermal comparative tuberculin test in cattle using Weybridge avian and bovine PPDs.

Runyon group III atypical mycobacteria as a cause of tuberculosis in a rhesus monkey.

Bilateral draining fistulas which communicated with the cheek pouches were noted in the threat region of an adult femal Macaca mulatta receiving isoniazid for tuberculosis prophylaxis. Necrospy findings included enlargedregional lymph nodes and ulceration of cheek pouch mucous membranes. Acid-fast bacilli were demonstrated in tissue section. Cultures of the regional lymph nodes and cheek pouch mucous membrane yielded Runyon Group III mycobacteria. Intrapalpebral tuberculin tests with homologous mycobacterial antigen (Battery strain PPD) and Kochs Old Tuberculin were performed in an unsuccessful attempt to identify additional infected monkeys. This case is considered significant because of the unusual manifestation of mycobacterial disease and its occurrence in an animal receiving isoniazid at levels considered sufficient for the prevention of tuberculosis.