Experimental infection of pregnant cows with Bacillus licheniformis bacteria

Infectious sporadic bovine abortions: retrospective analysis

Infectious sporadic abortions in cattle are mainly caused by opportunistic bacteria and fungi usually present in environmental or gastrointestinal and reproductive microbiota of healthy animals. A retrospective analysis was carried out to evaluate the main opportunistic microorganisms involved in bovine abortions recorded at INTA Balcarce (Argentina) from 1997 to 2023, accounting for 2.2% of the total diagnosed etiologies of bovine abortion. The opportunistic agents identified as the cause of abortion in 29 fetuses were bacteria (90%) and fungi (10%). Escherichia coli (n = 8), Trueperella pyogenes (n = 5), and Histophilus somni (n = 4) were the bacterial species most often identified as causing infectious abortions, whereas Aspergillus spp. (n = 3) was implicated in all fungal abortions identified. Pure culture of bacteria or fungus was achieved from abomasal content and/or lung essential. Main microscopic findings were bronchopneumonia, myo- and epicarditis, meningitis, and portal hepatitis. Herein, we highlight the importance of detecting potential infectious bacteria in cultures to improve etiological diagnosis of bovine abortions associated with compatible microscopic findings to confirm the etiology.

How platelet-rich plasma (PRP) intra-uterine injection improve endometrial receptivity of intrauterine adhesions in women: A time-series-based self-controlled study

Platelet-rich plasma (PRP) treatment proven to improve fertility outcomes in patients with a poor endometrial environment. However, the mechanism is not yet clear. In this study, we recruited 6 patients with infertility due to IUA and 6 normal control women. The subjects in the IUA group collected samples before and after PRP treatment. Endometrial receptivity was improved after PRP treatment. After PRP treatment, the endometrial NK cells, CD8 T cells and Th1 cells were significantly lower than those before treatment. Functional enrichment analysis suggested that the effects of changes in microbial composition played an important role in changes in the endometrial immune environment. Among them, the most significant difference was Bacillus. Our self-controlled cohort in this study can fully describe the detailed mechanism by which PRP treatment improves the endometrial environment.

Review of Diagnostic Procedures and Approaches to Infectious Causes of Reproductive Failures of Cattle in Australia and New Zealand

Infectious causes of reproductive failure in cattle are important in Australia and New Zealand, where strict biosecurity protocols are in place to prevent the introduction and spread of new diseases. Neospora caninum ranks highly as an important cause of reproductive wastage along with fungal and bacterial infections. Brucella, a leading cause of abortion elsewhere in the world, is foreign, following successful programs to control and eradicate the disease. Leptospirosis in cattle is largely controlled by vaccination, while Campylobacter and Tritrichomonas infections occur at low rates. In both countries, Bovine Viral Diarrhea virus (BVDV) infection rates as the second most economically important disease of cattle and one that also has an effect on reproduction. Effective disease control strategies require rapid diagnoses at diagnostic laboratories. To facilitate this process, this review will discuss the infectious causes of reproductive losses present in both countries, their clinical presentation and an effective pathway to a diagnosis.

Scientific Opinion on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA

EFSA is requested to assess the safety of a broad range of biological agents in the context of notification for market authorisation as sources of food and feed additives, food enzymes and plant protection products. The qualified presumption of safety (QPS) assessment was developed to provide a harmonised generic pre-assessment to support safety risk assessments performed by EFSA's scientific Panels. The safety of unambiguously defined biological agents (at the highest taxonomic unit appropriate for the purpose for which an application is intended), and the completeness of the body of knowledge are assessed. Identified safety concerns for a taxonomic unit are, where possible and reasonable in number, reflected as 'qualifications' in connection with a recommendation for a QPS status. The list of QPS recommended biological agents was reviewed and updated in the current opinion and therefore becomes the valid list. The 2016 update reviews previously assessed microorganisms including bacteria, yeasts and viruses used for plant protection purposes following an Extensive Literature Search strategy. The taxonomic units related to the new notifications received since the 2013 QPS opinion, were periodically evaluated for a QPS status and the results published as Statements of the BIOHAZ Panel. Carnobacterium divergens, Lactobacillus diolivorans, Microbacterium imperiale, Pasteuria nishizawae, Pediococcus parvulus, Bacillus flexus, Bacillus smithii, Xanthomonas campestris and Candida cylindracea were recommended for the QPS list. All taxonomic units previously recommended for the 2013 QPS list had their status reconfirmed as well their qualifications with the exception of Pasteuria nishizawae for which the qualification was removed. The exclusion of filamentous fungi and enterococci from the QPS evaluations was reconsidered but monitoring will be maintained and the status will be re-evaluated in the next QPS Opinion update. Evaluation of bacteriophages should remain as a case-by-case procedure and should not be considered for QPS status.

Lichenysin is produced by most Bacillus licheniformis strains

AIMS

The aim of this study was to elucidate the prevalence of lichenysin production in Bacillus licheniformis and to see whether this feature was restricted to certain genotypes. Secondly, we wanted to see whether cytotoxicity reflected the measured levels of lichenysin.

METHODS AND RESULTS

Fifty-three genotyped strains of B. licheniformis, representing a wide variety of sources, were included. lchAA gene fragments were detected in all strains by polymerase chain reaction (PCR). All 53 strains produced lichenysins with four molecular masses as confirmed by LC-MS/MS (liquid chromatography-tandem mass spectrometry) analysis. The amounts of lichenysin varied more than two orders of magnitude between strains and were irrespective of genotype. Finally, there was a strong association between lichenysin concentrations and toxicity towards boar spermatozoa, erythrocytes and Vero cells.

CONCLUSIONS

Lichenysin synthesis was universal among the 53 B. licheniformis strains examined. The quantities varied considerably between strains, but were not specifically associated with genotype. Cytotoxicity was evident at lichenysin concentrations above 10 μg ml(-1) , which is in accordance with previous studies.

SIGNIFICANCE AND IMPACT OF STUDY

This study might be of interest to those working on B. licheniformis for commercial use as well as for authorities who make risk assessments of B. licheniformis when used as a food and feed additive.

Bovine caruncular epithelial cell line (BCEC-1) isolated from the placenta forms a functional epithelial barrier in a polarised cell culture model

In the bovine synepitheliochorial placenta key sites of fetal-maternal interaction are placentomes consisting of maternal caruncles interdigitating with fetal cotyledons. The aim of this study was to establish an epithelial cell line from caruncles of pregnant cows and to develop a model to study restricted trophoblast invasion, pathogenesis of pregnancy associated diseases and pathways of infection and transport. Primary epithelial cells were isolated, successfully subcultured for 32 passages and cryopreserved at various stages. The cultures were termed bovine caruncular epithelial cell line-1 (BCEC-1). Cytokeratin, zonula occludens-1 protein and vimentin but neither alpha-smooth muscle actin nor desmin were detected by immunofluorescence performed every 5 (+/-1) passages. These results were confirmed by Western blotting. BCEC-1 were then cultured either without matrix or on fibronectin or collagen coated Transwell polyester membrane inserts, respectively, enabling separate access to the basal or apical epithelial compartments. Transmission and scanning electron microscopy of BCEC-1 revealed ultrastructural features also observed in vivo, such as apical microvilli and junctional complexes. Transepithelial electrical resistance (TEER) was measured regularly and revealed an increase with advancing confluence in all cultures. Cultures on coated inserts reached confluence and corresponding TEER-levels at an earlier stage. In addition, the cells were tested negative for bovine virus diarrhoea (BVD) virus, but were permissive for the virus. In conclusion, the BCEC-1 cell line retained characteristics of maternal caruncular epithelial cells as observed in vivo and in primary cell cultures and thus will be a highly useful tool for future studies of pathways of invasion, fetal-maternal communication, transport and infection.

Genotypic diversity among Bacillus licheniformis strains from various sources

Bacillus licheniformis is exploited industrially for the production of enzymes and has been shown to exhibit pathogenic properties. Because of these divergent characteristics, questions arise concerning intraspecies diversity. A comparative study by means of combined repetitive polymerase chain reaction, rpoB and gyrA sequencing, 16S rDNA targeted probe analysis, DNA-DNA hybridizations, gelatinase tests and antibiotic susceptibility tests was performed on a set of strains from diverse sources, including strains with pathogenic potential. B. licheniformis was found to consist of two lineages that are distinguished genotypically.

Association between postpartum pyrexia and uterine bacterial infection in dairy cattle

The temperature of 90 dairy cattle was recorded for the first 10 days after parturition and the animals were categorised as either normal (< 39.7 degreesC) or pyrexic. Swabs were collected from the uterine lumen seven, 14, 21 and 28 days after parturition for aerobic and anaerobic culture; bacteria were identified and their growth was scored semiquantitatively. Blood samples were collected three times a week for the estimation of the concentrations of acute phase proteins. The cows' temperatures were often above the accepted normal range, but it was not a good indicator of the number of bacteria in the uterus. However, pyrexia was correlated with the presence of specific uterine pathogens (P < 0.05) and in particular with Prevotella species (P < 0.01). The pyrexic animals had a higher plasma concentration of the acute phase protein (alpha1-acid glycoprotein (P < 0.05). Although pyrexia is an indicator of postpartum inflammation, additional clinical signs are necessary to identify uterine bacterial infection.