Atypical systemic mycobacteriosis in Hermann's tortoises (Testudo hermanni)

Background: Hermann's tortoise (Testudo hermanni) is a near threatened species found throughout southern Europe. Captive breeding of endangered species is subject to health risks, such as the stress of captivity and ambient conditions that may favor the emergence of infectious diseases. An episode of systemic atypical mycobacteriosis was investigated in six Hermann's tortoises from a captive population. The symptoms appeared in the form of anorexia, weakness, and lethargy, with inflammatory and edematous lesions of the hind limbs and tail. Four of the affected tortoises were euthanized and necropsied. Methods: Blood samples and joint aspirates were obtained for assessment. Euthanasia of four affected animals was performed. Postmortem examination included necropsy, histopathology, and mycobacterium detection by culture and polymerase chain reaction (PCR). In the other two animals, only hematology and blood biochemistry was carried out. Results: Hematological and blood biochemistry analyses gave inconsistent results. In joint aspirates, mononuclear cells with phagocytozed bacillary structures were observed. Ziehl-Neelsen stain revealed the presence of acid-fast bacteria. Granulomatous lesions were observed in liver, lungs, spleen, heart, muscle, kidney, and ovaries. Culture and identification were positive for mycobacteria and molecular sequencing led to the identification of Mycobacterium nonchromogenicum. Conclusions and clinical relevance: Although mycobacteriosis is rare in reptile collections, strict hygienic and prophylactic measures in species of high ecological value must be performed, especially if the animals are to be used for reintroduction projects.     

Atypical presentation of mycobacteriosis in a collection of frogfish (Antennarius striatus).

Severe systemic mycobacteriosis without typical granuloma formation was diagnosed in a group of six mature, captive, striated frogfish Antennarius striatus approximately 5 mo after fish originating from Brazil were purchased by Mote Marine Laboratory Aquarium. Beginning 1 mo after spawning, over a period of 9 mo, individuals began to show a variety of signs including egg retention, ocular opacity, poor buoyancy control, ascites with coelomic distension, skin lesions, and anorexia. Two fish died, and four were euthanatized. At necropsy, raised pigmented skin nodules; pale pink gills; and pale yellow or tan, fatty livers were noted. A systemic fungal infection was diagnosed histopathologically in one female, and the remaining fish had severe, systemic, histiocytic inflammation and necrosis. Although large numbers of acid-fast bacterial rods were identified in each fish, no bacteria were cultured aerobically from skin, kidney, spleen, liver, or brain. Mycobacterium marinum was cultured from the liver of the last fish that was euthanatized after it became moribund and failed to respond to symptomatic treatment.     

Metabolic test in pigs with experimental mycobacteriosis fed different amounts of nutrients

Three trials were conducted with pigs at different levels of nutrition. Seven groups of pigs were perorally infected with a suspension of M. intracellulare. Changes in 12 biochemical parameters of metabolism were studied in blood plasma or serum for 98 to 111 days. In comparison with the group of non-infected animals or with the situation prior to infection, the test pigs showed irregular and temporary changes in a number of metabolites, most frequently an increase in the concentration of urea, cholesterol, iron and vitamin A. In the majority of cases, the results are considered as non-typical of infection processes. It was also in relation to clinical and production parameters that the induced mycobacteriosis was regarded as a condition not disturbing, or just insignificantly influencing, the metabolism of slaughter pigs and the economy of their production. The changes in tocopherolaemia, reduction in alkaline phosphatase activity, increase in the total concentration of protein, albumin and cholesterol were related to the development of the pigs at the weight from 20 to 80 kg, rather than to the infection process. The limited intake of proteins or vitamin supplement allowed for verifying the possibility of using some biochemical parameters for practical diagnosis.     

A case of mycobacteriosis associated with Mycobacterium pseudoshottsii in aquarium-reared fish in Japan

In 2019, several aquarium-reared fish died at a sea life park in Japan. Necropsy revealed micronodules on the spleen in the dotted gizzard shad (Konosirus punctatus). Seven of 16 fish exhibited microscopic multifocal granulomas associated with acid-fast bacilli in the spleen, kidney, liver, alimentary tract, mesentery, gills, and/or heart. Bacterial cultures yielded isolates from the dotted gizzard shad and a Japanese sardine (Sardinops melanostictus). Microbiological and molecular biological examinations revealed the isolates as Mycobacterium pseudoshottsii. To our knowledge, this is the first isolation of M. pseudoshottsii from aquarium-reared fish.     

Brachyspira pilosicoli isolated from pigs in Japan

Two of four weak beta-hemolytic isolates of intestinal spirochetes isolated from pigs in Japan possessed a unique base alignment of TTTTTT on the 16S ribosomal DNA of Brachyspira pilosicoli and were identified as B. pilosicoli. The other two isolates were not identified by this technique. The identified isolates were 4.2 to 11 microm in length and 0.2 to 0.3 microm in diameter, 4 periplasmic flagella at each end were observed dominantly. The isolates were hippurate positive but indole negative. This is the first report on the isolation of B. pilosicoli from pigs in Japan.     

Isolation of vancomycin-resistant enterococci from pigs in Japan

Forty vancomycin‐resistant enterococci (VRE) were isolated from feces of pigs in one pig farm. Two strains were further elucidated and these were biochemically identified as Enterococcus faecium possessing the vanB gene. These isolates showed high resistance to vancomycin and nine other antibiotics. This is the first report of VRE contamination in pigs in Japan.     

Avian mycobacteriosis in three horses

The clinical, bacteriologic and pathologic findings of three adult horses suffering from avian tuberculosis are presented. Chronic weight loss and hypoproteinemia were pertinent clinical abnormalities in all three horses. Gross pathologic lesions were characterized by chronic enterocolitis with mesenteric lymphadenopathy in two horses and hepatic granulomas in the third horse. The microscopic diagnoses were chronic, non-caseating granulomatous enterocolitis, and necrotizing, non-mineralizing granulomatous hepatitis, respectively. All three horses had granulomatous lymphadenitis of mesenteric lymph nodes with varying degrees of non-mineralizing, coagulation necrosis. Various serotypes of the Mycobacterium avium-intracellulare complex were isolated from selected tissues and feces.     

Isolation and serological survey of Salmonella in pigs in Japan

A total of 267 fecal and serum samples collected from individual pigs reared on a Salmonella-positive farm were subjected to bacteriological and serological examinations of Salmonella. Salmonella was isolated from 47 pigs (17.6%) and prevalence of antibody to lipopolysaccharide (LPS) of S. Typhimurium, which was partly common to S. O4, 12: d: -, was observed in 90 pigs (33.7%). Salmonella was isolated from 26 (28.9%) of 90 antibody-positive pigs and 21 (11.9%) of 177 antibody-negative pigs. Twenty-one of 36 pigs (58.3%) positive for S. O4, 12: d: -, five of 10 pigs (50.0%) positive for S. Havana, and none for S. Anatum had antibodies. Thus, seropositive rates were higher than isolation-positive rates, and antibody prevalence was associated with serovars of the isolates. Then, we analyzed antibody prevalence among pigs on Japanese pig farms. The antibodies to LPS of S. Typhimurium were found in 195 of 1,498 pigs (13.0%) and in at least one serum sample on 35 of 52 farms (67.3%). Our results indicate that Salmonella does not seem to be so prevalent in pigs though it is widely prevalent among pig farms.     

Nationwide surveillance of salmonella in the faeces of pigs in Japan

The prevalence of faecal carriage of salmonella in 5393 pigs reared on 218 pig farms located in 31 of 47 prefectures in Japan over the period July 2003 to June 2005 was investigated. We isolated 172 strains belonging to 20 serovars and one untypable Salmonella enterica from 169 pig faecal samples (3.1%) collected from 48 farms (22.0%). The most prevalent type of S. enterica was untypable O4,12:d:- which lacks phase 2 flagellar antigen, representing 29.1% (50/172) of all isolates. Of 26 S. enterica serovar Typhimurium isolates, 16 strains appeared to be definitive phage type 104 (DT104) by polymerase chain reaction.     

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.