Screening of Hungarian cattle herds for seropositivity to Mycoplasma bovis.

A total of 860 serum samples collected at 86 cattle farms in different parts of Hungary were screened for the presence of antibodies to Mycoplasma bovis using an ELISA test with a recombinant M. bovis membrane protein as antigen. Antibodies to M. bovis were detected in sera collected on all farms, and no farms negative for M. bovis were found. In 88.38% of the herds more than 50% of the sampled animals were infected by M. bovis. A total of 82.91% of the animals had antibodies to M. bovis. The proportion of seropositive animals was higher in the older age groups, and a significant difference was seen in the level of seropositivity between young and older age groups. The results show that M. bovis infection is widespread on Hungarian dairy farms, and its prevalence has increased in the recent decade. The high infection rate of Hungarian cattle herds with M. bovis shows that special attention should be paid to evaluating the aetiological role of M. bovis in bovine respiratory disease complex (BRDC) cases because M. bovis has an immunosuppressive effect and can predispose cattle to other respiratory infections, too.

Vertebral osteomyelitis and meningomyelitis caused by Pasteurella canis in a dog--clinicopathological case report.

A clinicopathological case study of vertebral osteomyelitis caused by Pasteurella canis in a 2.5-year-old male Jack Russell Terrier is presented. The case was characterised by a chronic course with signs of spinal pain and acute paraplegia. The diagnosis was established by radiography, myelography, post-myelographic CT examination, and laboratory tests including routine blood work and cerebrospinal fluid (CSF) cytology, and confirmed by postmortem pathological and microbiological examinations. Diagnostic imaging showed severe osteolysis, ventral spondylosis and spinal cord compression at the 4th and 5th lumbar vertebrae. The blood tests revealed mild leukocytosis and anaemia, while CSF cytology showed lymphocytic and mononuclear pleocytosis. Necropsy demonstrated severe osteomyelitis and meningomyelitis, but the source of infection could not be established. To the authors' knowledge, this is the first description of canine vertebral osteomyelitis caused by this organism.

Susceptibility of the common hamster (Cricetus cricetus) to Francisella tularensis and its effect on the epizootiology of tularemia in an area where both are endemic.

Francisella tularensis is a highly infectious zoonotic agent causing the disease tularemia. The common hamster (Cricetus cricetus) is considered a pest in eastern Europe, and believed to be a source of human tularemia infections. We examined the role of the common hamster in the natural cycle of tularemia using serologic methods on 900 hamsters and real-time polymerase chain reaction (PCR) on 100 hamsters in an endemic agricultural area. We collected 374 Ixodes acuminatus ticks from the hamsters and tested them by real-time PCR. All tests were negative. To examine clinical signs, pathology, and histopathology of acute tularemia infection similar to the natural infection, two hamsters were infected with a large dose of a wild strain of F. tularensis ssp. holarctica. After a short period of apathy, the animals died on the eighth and ninth days postinfection. The pathologic, histopathologic, and immunohistochemical examination contributed to the diagnosis of septicemia in both cases. Our results confirmed previous findings that common hamsters are highly sensitive to F. tularensis. We conclude that although septicemic hamsters may pose substantial risk to humans during tularemia outbreaks, hamsters in interepizootic periods do not act as a main reservoir of F. tularensis.

Aerosol infection of calves with Histophilus somni.

The purpose of this study was to develop and evaluate an aerosol infection method with Histophilus somni that closely resembles the natural way of infection of calves. Another aim was to compare the virulence of two H. somni strains by collecting clinical and postmortem data of experimentally infected and control animals. Seventeen conventionally reared 3-month-old calves were divided into three groups. Two groups of six animals each were exposed to suspensions containing H. somni on three consecutive days using a vaporiser mask. The third group of five animals was used as control. The data of individual clinical examination were recorded daily. All animals were exterminated, and gross pathology of all lungs was evaluated on the 15th day after the first infection. Both H. somni strains caused an increase of rectal temperature, respiratory signs, decrease of weight gain, and severe catarrhal bronchopneumonia in both infected groups. Although some chronic lesions were detected in the lungs of the control animals as well, the histopathological findings in the infected and control groups were different. H. somni was recultured from all lungs in the challenged groups but it could not be reisolated or detected by PCR examination in the control group. This is the first paper on aerosol challenge of calves with H. somni using repeated infection and verified by detailed pathological, bacteriological and histopathological examination. The infection method proved to be successful. There was no difference in the virulence of the two H. somni strains used in the trial.

Generalized tularemia in a vervet monkey (Chlorocebus aethiops) and a patas monkey (Erythrocebus patas) in a zoo.

Generalized tularemia was diagnosed in a vervet monkey (Chlorocebus aethiops) and a patas monkey (Erythrocebus patas), both of which died suddenly in the Szeged Zoo, Szeged, Hungary. Macroscopic lesions in each animal included disseminated, grayish-white foci in the lungs, lymph nodes, spleen, liver, and kidney. All focal lesions were characterized microscopically as purulent to pyogranulomatous to granulomatous inflammation with necrosis. Francisella tularensis subsp. holarctica strains were isolated from tissue samples on modified Francis agar after mouse passage and identified by a commercial carbon-source utilization test and polymerase chain reaction-based amplification and sequencing of a portion of the 16S ribosomal RNA gene.

First isolation of Histophilus somni from goats.

Histophilus somni (former name: Haemophilus somnus) is a Gram-negative, facultative pathogen bacterium that colonises the mucous membranes of cattle and sheep, however it was also described in American bison and bighorn sheep. It can cause local or generalised diseases and asymptomatic carriers can also occur. The presence and the etiological role of this microorganism have not been confirmed in any other domesticated species yet. The purpose of this study was to prove the presence of H. somni in goats by bacterial isolation. Nasal, vaginal or praeputial swab samples were collected from 205 goats in 10 flocks. H. somni strains were isolated from 2 out of 10 flocks; in one flock 10 H. somni strains were isolated from the genital mucosa of 17 goats, while a single H. somni strain was cultured from a vagina of 26 animals in the other flock. Partial amplification and sequencing of the 16S rRNA gene of three H. somni strains verified the identification. The comparative examination of carbon source metabolism using the Biolog Microstation ID System (Biolog, Ca) showed a close relationship of the caprine strains, while they were less related to H. somni type strain CCUG-36157 of bovine origin. H. somni strains were isolated only in the oestrus season from goat flocks with sheep contact. This is the first paper on isolation of H. somni from goats.

Isolation and characterisation of Rhodococcus equi from submaxillary lymph nodes of wild boars (Sus scrofa).

Rhodococcus equi has been isolated from the submaxillary lymph nodes of domesticated pigs, but little is known about the presence of R. equi in wild boars. The aim of the study was the evaluation of the incidence of R. equi in wild boars and the characterisation of them. Of 482 submaxillary lymph nodes of wild boars shot in 39 settlements throughout Hungary, R. equi was isolated from 60 specimens, and plasmid types of 82 isolates were examined. The isolates were tested for the presence of 15-17-kDa (VapA) and 20-kDa virulence-associated protein antigen (VapB) genes by polymerase chain reaction (PCR). Plasmid DNAs were isolated and analysed by digestion with restriction endonucleases to estimate size and compare their polymorphisms. None of the 82 isolates contained vapA gene but 21 isolates (25.6%) were positive for vapB gene showing 827bp product of the expected size in the PCR amplification. Sixty-one strains (74.4%) did not contain plasmid. The 21 isolates of intermediate virulence contained virulence plasmids that were identified as types 1 (1 isolate), 5 (16 isolates), 21 (1 isolate), and three new distinct plasmid variants (1-1-1 isolate), respectively. On the basis of restriction digestion patterns of plasmid DNAs, we tentatively designated the new variants as types 25-27, respectively. The prevalence of R. equi strains of intermediate virulence among the isolates originated from the submaxillary lymph nodes of wild boars (25.6%) is very similar to those of domestic pigs (26.8%) in Hungary, and plasmid type 5 is the predominating one in both groups. This is the first report of isolation of VapB-positive R. equi from wild boars in the world.