Brucellosis of the common vole (Microtus arvalis).

A systemic disease occurred in a wild population of the common vole Microtus arvalis in South Moravia (Czech Republic) during the years 1999-2003. Acute infections were characterized by edema of extremities, occasionally with colliquating abscesses, arthritis, lymphadenitis, perforations of the skin resulting from colliquated abscesses, orchitis, and peritoneal granulomas. From the clinical samples, small Gram-negative coccobacilli were isolated and identified as Ochrobactrum intermedium by API 20NE and colistin sensitivity profiles. However, subsequent rrs (16S rRNA) and recA (recombinase A) gene sequencing analysis of two isolates (CCM 4915=CAPM 6434; CCM 4916=CAPM 6435) identified them as Brucella sp. with sequence identities of 100% to other Brucella spp. Analysis of the omp2a/b genes confirmed the two isolates as Brucella. In AMOS polymerase chain reaction (PCR), a 2000-bp fragment was generated that was not seen in other brucellae. Experimental infection of outbred ICR mice with these isolates resulted in a mortality rate of 50%. Based on the results of the molecular investigations and the mortality observed in experimentally infected mice we conclude that the epizootic was caused by Brucella sp. and not by Ochrobactrum intermedium. The study demonstrates the limitations of commercial biochemical test systems in accurately differentiating among Ochrobactrum and Brucella.

Emmonsiosis of rodents in an agroecosystem.

Adiaspores of Emmonsia crescens were found in the lungs of 62.1% of 87 adult rodents from 10 windbreaks compared to only 8.2% of 184 adult rodents caught in 10 adjacent arable fields in South Moravia, Czechland. A significantly higher mean weight proportion of plant remnants (predominantly small roots) was present in the soil from windbreaks (0.74%) than from fields (0.24%). In addition, mean relative abundance of rodents was significantly higher in windbreaks than in fields, and the windbreak soil was more acidic (pH 6.2 vs. 6.9, respectively). On the other hand, there was no significant difference in the water content (17.4% vs. 18.5%, respectively). The difference in the infection rate between the two habitats of the agroecosystem could be caused or affected by land use and farming technology.

A heterogeneous distribution of Emmonsia parva var. crescens in an agro-ecosystem.

The lung tissue of 1143 rodents of five species, caught at a number of sites and habitats in an agro-ecosystem (southern Moravia, Czech Republic) in 1988-1993, was examined for the presence of adiaspores of Emmonsia parva var. crescens (Emmons et Jellison) van Oorschot. The overall prevalence of adiasporomycosis was 16.6%, but its distribution varied significantly according to rodent species (Clethrionomys glareolus 37.6%, Apodemus flavicollis 33.3%, A. sylvaticus 21.1%, A microps 9.2%, Microtus arvalis 2.7%) and habitat (lucerne fields 2.8%, fields with other crops 10.6%, windbreaks 33.1%, woods 15.8%). Wooded areas have consistently higher prevalence rates of rodent adiasporomycosis than arable fields. Some windbreaks could form natural foci of adiasporomycosis in the agricultural, largely deforested landscape.