Demodex carolliae in a colony of Seba's short-tailed bats (Carollia perspicillata): clinical, pathological and parasitological findings.

Seba's short-tailed bats (Carollia perspicillata) are a frugivorous species native to Central and South America. Despite their importance as a reservoir for zoonotic pathogens and their popularity in zoological collection and as research models, there are relatively few reports on non-zoonotic diseases of bats. Mites of the genus Demodex are obligate commensals of the skin of a range of mammals, are highly host-specific and are not associated with clinical disease when present in low numbers. However, infestation with high numbers can result in severe or even fatal disease and substantially affect the well-being of the animals. The clinical, pathological and parasitological findings in 12 Seba's short-tailed bats with demodicosis from a colony kept at Munich Zoo Hellabrunn between 1992 and 2021 are described in this report. From 2002, skin lesions became apparent on the head, especially the periocular region, nose and ears, as well as the genital area of some animals. In advanced cases, skin changes were also present on the abdomen, back and extremities. Gross findings typically included alopecia and thickening of the skin, with the formation of papules, reflecting cystically dilated hair follicles containing myriads of demodecid mites. Histologically, lesions were characterized by a paucicellular lymphocytic dermatitis and folliculitis with perifollicular fibrosis, epidermal hyperplasia, orthokeratotic hyperkeratosis and disproportionately high numbers of intrafollicular arthropods. Demodex carolliae was identified morphologically by light, phase-contrast and electron microscopy. Further characterization was achieved by extraction of parasitic DNA and partial gene sequencing of two mitochondrial genes, 16S rDNA and cox1. This is the first clinicopathological description of generalized demodicosis in Seba's short-tailed bats and includes the first molecular characterization of D. carolliae with provision of a GenBank entry.

Prevalence of spotted fever group rickettsiae in Ixodes ricinus (Acari: Ixodidae) in southern Germany.

Host-seeking Ixodes ricinus (L.) (Acari: Ixodidae) ticks were collected systematically, from May to September 2006, at selected sites in southern Germany, including a large city park in Munich. Polymerase chain reactions for amplification of genes of the rickettsial citrate synthase (gltA), the outer membrane proteins A and B (ompA and ompB), and the 16S rDNA were used to investigate 2,861 specimens (adults and nymphs). GltA sequences of spotted fever group rickettsiae were detected in 151 of all samples (5.3%; 95% CI = 4.3-6.2%). Sequencing revealed Rickettsia helvetica in 91.4% of the samples and R. monacensis in 8.6%. Amplification of ompA was not possible for R. helvetica, but in all except one of the R. monacensis. The results were analyzed statistically to test the effects of season, location, developmental stage, and gender of the tick on prevalence of Rickettsia spp. Although rickettsial DNA was detected in all investigated sites, sites in natural forest areas had significantly higher prevalences than sites in landscaped city parks. Adult female and male ticks had a similar prevalence and were significantly more often infected than nymphs. Monthly differences were not statistically significant. These results clearly show that R. helvetica is widespread throughout the study region and could result in a threat to public health in areas of high prevalence.

The equine herpesvirus 1 UL20 product interacts with glycoprotein K and promotes egress of mature particles.

The aim of the present study was to identify and functionally characterize the equine herpesvirus 1 (EHV-1) UL20 protein (UL20p). Using a specific antiserum, UL20p was shown to be associated with membranes of infected cells, as well as with envelopes of purified virions. By Western blot analysis, UL20p was detected in two main forms exhibiting M(r)s of 25,000 and 75,000. Both moieties did not enter the separating gel after heating of protein samples to 99 degrees C. The slower-migrating form of UL20p contains N-linked carbohydrates, and its presence is dependent of that of other viral proteins. Infection of cells that either constitutively express UL20p or a gK-green fluorescent protein (GFP) fusion protein with various EHV-1 deletion mutants revealed a relatively stable hetero-oligomer containing gK and UL20p with an apparent M(r) of 75,000. As demonstrated by confocal microscopy, UL20p distribution in Rk13 cells changed from a diffuse granular or netlike appearance to a pattern confined to the Golgi network when gK was coexpressed. Analysis of a UL20 deletion mutant of EHV-1 strain RacL11 indicated an involvement of UL20p in cell-to-cell spread, as well as in very late events in virus egress. Based on these and electron microscopic studies we suggest that the EHV-1 UL20 protein might be necessary to avoid fusion of mature virions with membranes of their transport vesicles.

A glycoprotein M-deleted equid herpesvirus 4 is severely impaired in virus egress and cell-to-cell spread.

To analyse the function of the equid herpesvirus 4 (EHV-4) glycoprotein M homologue (gM), two different mutated viruses (E4DeltagM-GFP and E4DeltagM-w) were generated. Both gM-negative EHV-4-mutants were characterized on complementing and on non-complementing cells and compared with E4RgM, a virus where gM-expression had been repaired. It was demonstrated in virus growth kinetics that deleting gM had a more dramatic influence on EHV-4 replication than expected. Extracellular infectivity was detected 9-12 h later than in EHV-4-infected Vero cells and titres were reduced up to 2000-fold. In addition, mean maximal diameters of plaques were less than 20 % of diameters of wild-type plaques. These results are in contrast to most other alphaherpesviruses, including the closely related equid herpesvirus type 1, where deletion of gM only marginally influences the ability of viruses to replicate in cell culture. Nevertheless, analysis of infected cells by electron microscopy did not reveal a specific defect for deleting gM. It was concluded that EHV-4 gM is important for more than one step in virus replication in cell culture, influencing both efficient virus egress and cell-to-cell spread.

The equine herpesvirus 1 UL34 gene product is involved in an early step in virus egress and can be efficiently replaced by a UL34-GFP fusion protein.

The structure and function of the equine herpesvirus type 1 (EHV-1) UL34 homologous protein were characterized. A UL34 protein-specific antiserum reacted with an M(r)28,000 protein that could not be detected in purified extracellular virions. Confocal laser scanning microscopy demonstrated that UL34 reactivity mainly concentrated at the nuclear rim, which changed into a punctuate and filamentous pattern at late times after infection. These changes in UL34 distribution were especially prominent when analyzing the distribution of a GFP-UL34 fusion protein. A UL34-negative EHV-1 was generated by mutagenesis of a recently established BAC clone of EHV-1 strain RacH (pRacH). Release of extracellular infectious virus was severely impaired after infection of Rk13 cells with HDelta34. Electron microscopy revealed a virtual absence of virus particles in the cytoplasm of infected cells, whereas nucleocapsid formation and maturation within the nucleus appeared unaffected. A UL34-GFP fusion protein with GFP linked to the C-terminus of UL34 was able to complement for the UL34 deletion in trans, while a GFP-UL34-fusion protein with GFP linked to the N-terminus of UL34 was able to only partially restore virus growth. It was concluded that the EHV-1 UL34 product is essential for an early step in virus egress, i.e., release of capsids from infected-cell nuclei.