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Summary: Since the first report of bovine digital dermatitis (DD) in 1974, there is a large body of the literature published; however, effective prevention and control of the disease remain elusive. Although many aspects of the pathogenesis of DD have been investigated, even some of the most basic questions such as the aetiology of this disease remain under debate. Treponema spp. have been strongly associated with DD lesions and occur in abundance in advanced lesions; however, efforts to induce disease with pure cultures of these organisms have been largely underwhelming and inconsistent. Furthermore, although the disease has been presented for several decades, there is limited scientific evidence regarding effective treatment of DD. Apparent discrepancies between effectiveness in vitro and in vivo have challenged the scientific community to identify new potential treatment options. With no treatment resulting in a 100% cure rate, the current expectation is manageable control, but prospects for the eradication of the disease are unlikely using current approaches. In order to develop more effective approaches to control DD on‐farm, there is a critical need for a deeper understanding regarding the causation, ecology, transmission and treatment of this disease. In this article, we attempt to provide insights into specific research needs related to DD in order to assist the industry, researchers, pharmaceutical companies and research sponsors with decision‐making and identified research gaps. [ABSTRACT FROM AUTHOR]

Fermentation reactions in the caeca of chickens, the predominant place for Salmonella colonization, result in high concentrations of short-chain fatty acids (SCFA). Thus Salmonella bacteria are in close contact with SCFA during their life cycle. A study was carried out to analyse the effects of SCFA on invasion of Salmonella enteritidis in an avian intestinal epithelial cell line. Preincubation of S. enteritidis for 4 h in growth media supplemented with various concentrations of propionate or butyrate resulted in decreased invasion compared to bacteria, preincubated in nonsupplemented media, and to bacteria, preincubated in media supplemented with formate or acetate. Incubation of the S. enteritidis bacteria in media supplemented with mixtures of SCFA mimicking the in vivo caecal concentrations resulted in increased invasion compared with butyrate-exposed bacteria, but equal invasion compared with nonexposed bacteria. Increasing the butyrate concentration in these mixtures did not modify invasion compared with the original mixtures. [Copyright &y& Elsevier]

Reports the detection of polymerase chain reaction of avian mycoplasmas from environmental swabs of poultry houses. Effects of the two pathogenic mytoplasmas on commercial poultry; Use of molecular techniques to detect mycoplasma synoviae in the environment; Importance of cellular immune reponse for the development of a protective immune response.

Johne's disease (JD; paratuberculosis) control programs have been regionally implemented across the globe, but few have successfully eradicated the pathogen (Mycobacterium avium ssp. paratuberculosis (MAP)) causing this disease. The limited success may partly be attributed to excluding young stock (calves and replacement heifers or bulls) from testing strategies aimed at identifying MAP-infected cattle. Young stock can shed MAP in feces and can have detectable MAP-specific antibodies in blood, as confirmed in experimentally and naturally infected cattle. Furthermore, MAP transmission causes new infections in young stock. Calves and heifers are often included in JD management strategies on dairy farms but excluded from conventional diagnostic tests due to a presumed lag between infection and detection of MAP shedding and/or MAP-specific serum antibodies. We summarize evidence of MAP shedding early in the course of infection and discuss promising diagnostics, testing and management strategies to support inclusion of young stock in JD control programs. Improvements in fecal Polymerase Chain Reaction, interferon-gamma release assay (IGRA), and enzyme-linked immunosorbent assay (ELISA) enable earlier detection of MAP and specific early immune responses. Studies on IGRA and ELISA have focused on evaluation of new antigens and optimal age of testing. There are new diagnostics, including phage-based tests to detect viable MAP, and gene expression patterns and metabolomics to detect MAP-infected young stock. In addition, refinements in testing and management of calves and heifers may enable reductions in MAP prevalence. We provide recommendations for dairy farmers, researchers, veterinarians, and other stakeholders that may improve JD control programs with an objective to control and potentially eradicate JD. Additionally, we have identified the most pressing gaps in knowledge that currently hamper inclusion of young stock in JD prevention and control programs. In summary, transmission among young stock may cause new MAP infections, and appropriate use of new diagnostic tests, testing and management strategies for young stock may improve the efficacy of JD control programs., (© 2025, The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Conventional Mycoplasma spp. diagnostics involve culture, often considered the gold standard in diagnostic test evaluation. However, culture protocols lack empirical derivation and primarily adhere to National Mastitis Council recommendations, tracing back to initial cultivation of Mycoplasma bovis . Despite a wide range of carbon dioxide (CO 2 ) supplementation reported in literature, specific impacts of CO 2 on Mycoplasma spp. growth remain unexplored. Our objective was to assess the effect of CO 2 concentration on growth detection rates of 24 Mycoplasma spp. isolates from dairy cows. These isolates, mainly M. bovis , were incubated at 37°C in triplicate and three dilution ranges under three CO 2 conditions: ambient air or 5% CO 2 or 10% CO 2 . Bacterial growth was evaluated on incubation days 3, 5, 7, and 10. When cultured using ambient air, log 10 cfu/mL was lower on days 3, 5, and 7 of incubation compared with isolates incubated in the recommended 5% or 10% CO 2 , with less variation observed in ambient air compared with 5% or 10% CO 2 . However, by 10 days of incubation, no differences in the detection of observable growth were noted among isolates incubated in ambient air, 5% CO 2 , or 10% CO 2 . Consequently, Mycoplasma spp. isolated from dairy cattle demonstrated growth after the recommended 7-10 days of culture, even in the absence of supplemental CO 2 . Given the expected concentration of M. bovis in (sub)clinical samples had similar concentrations to those used in our study, with the majority of isolates being M. bovis , we recommend expanding CO 2 concentration ranges in M. bovis culture from 10% CO 2 to ambient air when incubating for 10 days. However, the turnaround time could be shortened when incubating with supplemental CO 2 ., Importance: Current Mycoplasma spp. culture protocols lack empirical derivation concerning carbon dioxide (CO 2 ) supplementation and are primarily based on the initial cultivation of Mycoplasma bovis . This study indicates that the suitable range for CO 2 supplementation is broader than what is currently recommended by the National Mastitis Council for culturing within the specified 7-10 days. No differences in bacterial growth detection rates were observed among ambient air, 5% CO 2 , or 10% CO 2 supplementation during the 7- and 10-day incubation intervals. These new insights provide evidence supporting the possibility of culturing Mycoplasma spp. under ambient air conditions in a laboratory setting., Competing Interests: The authors declare no conflict of interest.