Molecular characterization of a bovine adenovirus type 7 (Bovine Atadenovirus F) strain isolated from a systemically infected calf in Germany.

Bovine adenovirus 7 (BAdV-7) is an unclassified member of the genus Atadenovirus with a worldwide distribution and has been reported to induce clinical disease of varying severity in infected cattle, ranging from asymptomatic infections to severe enteric or respiratory disease. In this study, we used next-generation sequencing to obtain the first complete genome sequence of a European strain of BadV-7, from pooled spleen and liver tissue obtained from a deceased newborn Limousin calf. Histopathological analysis and electron microscopy showing systemic lesions in multiple organs with intranuclear amphophilic inclusions observed in endothelial cells in multiple peripheral tissues. Virus isolation was readily achieved from tissue homogenate using bovine esophagus cells (KOP-R), a strategy which should facilitate future in vitro or in vivo BAdV-7 studies. Phylogenetic analysis of available genome sequences of BAdV-7 showed that the newly identified strain groups most closely with a recent BAdV-7 strain, SD18-74, from the USA, confirming that this newly identified strain is a member of the Atadenovirus genus. The fiber gene was found to be highly conserved within BAdV-7 strains but was highly divergent in comparison to Ovine adenovirus 7 (OAdV-7) (39.56% aa sequence identity). Furthermore, we report a variable region of multiple tandem repeats between the coding regions of E4.1 and RH5 genes. In summary, the presented pathological and molecular characterization of this case suggests that further research into the worldwide molecular epidemiology and disease burden of BAdV-7 is warranted.

The Canine Vaginal Flora: A Large-Cohort Retrospective Study.

Microbiological examinations are frequently performed as part of breeding management examinations in the bitch, but also in case of (suspected) reproductive tract problems. As most bacteria are opportunistic pathogens, evaluation of bacterial findings is challenging for veterinarians. Besides, breeders might request antimicrobial treatment in breeding bitches, fearing conception failure-even without medical indication. Considering the rising threat of antimicrobial resistance, gaining deeper insights into the bacterial findings from the vagina of healthy and (suspected) reproductive-diseased bitches might contribute to the knowledge of the canine aerobic vaginal flora and consequently improve the responsible use of antibiotics. We analyzed results from bacteriological cultures of 23,254 vaginal swabs sent in to three commercial laboratories in Germany between 2015 and 2021, where standard aerobic microbiological examination was carried out. We found a variety of 319 bacterial species that mostly grew in mixed cultures of two or more bacterial species. Commonly found species were Escherichia coli, beta-hemolytic Streptococci, coagulase-positive Staphylococci, Pasteurellales, and aerobic sporulators, as well as other Streptococcus spp. Our results showed a large diversity of the canine vaginal flora in healthy and (suspected) reproductive-diseased bitches. They largely support earlier findings of small studies on the physiological canine vaginal flora, emphasizing that solely the results of a bacterial evaluation should not be the base for antimicrobial treatment. Instead, bacterial findings should be evaluated with the results of a clinical gynecological examination.

Antimicrobial susceptibility profiles of Mycoplasma hyorhinis strains isolated from five European countries between 2019 and 2021.

Mycoplasma hyorhinis is an emerging swine pathogen bacterium causing polyserositis and polyarthritis in weaners and finishers. The pathogen is distributed world-wide, generating significant economic losses. No commercially available vaccine is available in Europe. Therefore, besides improving the housing conditions for prevention, antimicrobial therapy of the diseased animals is the only option to control the infection. Our aim was to determine the minimal inhibitory concentrations (MIC) of ten antimicrobials potentially used against M. hyorhinis infection. The antibiotic susceptibility of 76 M. hyorhinis isolates from Belgium, Germany, Hungary, Italy and Poland collected between 2019 and 2021 was determined by broth micro-dilution method and mismatch amplification mutation assay (MAMA). Low concentrations of tiamulin (MIC90 0.312 µg/ml), doxycycline (MIC90 0.078 µg/ml), oxytetracycline (MIC90 0.25 µg/ml), florfenicol (MIC90 2 µg/ml) and moderate concentrations of enrofloxacin (MIC90 1.25 µg/ml) inhibited the growth of the isolates. For the tested macrolides and lincomycin, a bimodal MIC pattern was observed (MIC90 >64 µg/ml for lincomycin, tulathromycin, tylosin and tilmicosin and 5 µg/ml for tylvalosin). The results of the MAMA assay were in line with the conventional method with three exceptions. Based on our statistical analyses, significant differences in MIC values of tiamulin and doxycycline were observed between certain countries. Our results show various levels of antimicrobial susceptibility among M. hyorhinis isolates to the tested antibiotics. The data underline the importance of susceptibility monitoring on pan-European level and provides essential information for proper antibiotic choice in therapy.

Yeasts in Liquid Swine Diets: Identification Methods, Growth Temperatures and Gas-Formation Potential.

Liquid feed is susceptible to microbiological growth. Yeasts are said to cause sudden death in swine due to intestinal gas formation. As not all animals given high yeast content feed fall ill, growth and gas formation potential at body temperature were investigated as possible causally required properties. The best identification method for these environmental yeasts should be tested beforehand. Yeasts derived from liquid diets without (LD - S) and liquid diets with maize silage (LD + S) were examined biochemically (ID32C-test) and with MALDI-TOF with direct smear (DS) and an extraction method (EX). Growth temperature and gas-forming potential were measured. With MALDI-EX, most yeast isolates were identified: Candida krusei most often in LD - S, and C. lambica most often in LD + S, significantly more than in LD - S. Larger colonies, 58.75% of all yeast isolates, were formed at 25 °C rather than at 37 °C; 17.5% of all isolates did not grow at 37 °C at all. Most C. krusei isolates formed high gas amounts within 24 h, whereas none of the C. lambica, C. holmii and most other isolates did. The gas pressure formed by yeast isolates varied more than tenfold. Only a minority of the yeasts were able to produce gas at temperatures common in the pig gut.

Spontaneous listeriosis in grey mouse lemurs (Microcebus murinus), but not in Goodman's mouse lemurs (Microcebus lehilahytsara) of the same colony.

Listeriosis is a zoonotic infection with the gram positive, facultative intracellular bacterium Listeria (L.) monocytogenes. Infections mainly occur in ruminants, but also in other species, including humans. Case fatality rate usually is high. The incidence of listeriosis in captive non-human primates is very low. We report the first spontaneous, fatal, and likely food-born outbreak of listeriosis in a population of captive grey mouse lemurs (Microcebus murinus). Conspicuously, none of the closely related Goodman's mouse lemurs (Microcebus lehilahytsara) in the same facility were affected.