Microbiological and molecular detection of Mycoplasma bovis in milk samples from bovine clinical mastitis

Point-of-care potentials of lateral flow-based field screening for Mycoplasma bovis infections: a literature review

Point-of-care (POC) field screening for tools for Mycoplasma bovis (M. bovis) is still lacking due to the requirement for a simple, robust field-applicable test that does not entail specialized laboratory equipment. In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, this review identifies the methodologies that were retrieved based on our search strategy that have been reported for the diagnosis of m. bovis infection between 2014 and diagnostics. A search criterion was generated to curate 103 articles, which were reduced in number (to 46), following the screening guidelines of PRISMA. The 43 articles included in the study present 25 different assay methods. The assay methods were grouped as microbiological culture, serological assay, PCR-based assay, LAMP-based assay, NGS-based assay, or lateral flow assay. We, however, focus our discussion on the three lateral flow-based assays relative to others, highlighting the advantages they present above the other techniques and their potential applicability as a POC diagnostic test for M. bovis infections. We therefore call for further research on developing a lateral flow-based screening tool that could revolutionize the diagnosis of M. bovis infection.

A Systematic Review of the Recent Techniques Commonly Used in the Diagnosis of Mycoplasma bovis in Dairy Cattle

Early detection of Mycoplasmal mastitis is greatly hampered by late seroconversion, slow growth of Mycoplasma organisms, intermittent shedding, and the high cost of diagnostic tests. To improve future diagnostic development, examining the available techniques is necessary. Accordingly, the present study systematically reviewed M. bovis diagnostic studies published between January 2000 and April 2023 utilizing the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) protocol. The protocol registration was performed according to the Open Science Framework (osf.io/ug79h), and the electronic search was conducted in the World Catalog, Mendeley, ProQuest, ScienceDirect, Semantic Scholar, PubMed, Google Scholar, Prime Scholar, and PubMed Central databases using a Boolean operator and inclusion and exclusion criteria. Of the 1194 pieces of literature retrieved, 67 studies were included. Four broad categories of up to 16 diagnostic approaches were reported: microbial culture, serological, DNA-based, and mass spectrometry. Overall, DNA-based techniques were the most published (48.0%), with recombinase polymerase amplification (RPA) and loop-mediated isothermal amplification (LAMP) as the most promising user-friendly, equipment-free techniques. On the other hand, mass spectrometry was reported as the least utilized (2.9%) given the high equipment cost. Though costly and laboratory-allied, DNA-based techniques, particularly PCRs, were reported as the most rapid and specific approach.

Impact of udder infections on biochemical composition of milk in context of pesticides exposure

Background and Aim:

Environmental contaminants such as pesticides have shown immunomodulatory effects that can make animals highly susceptible to pathogenic invasion. The current work aims to study the incidence of udder infections in a single dairy herd of 160 cows in Qalyoubia Governorate, in relation to the potential intoxication of dairy cattle with organochlorine (OCs) pesticides. The study also aims to investigate the impact of udder infections on milk composition.

Materials and Methods:

The dairy herd was screened for udder infections using the California mastitis test and measurement of somatic cell count (SCC), followed by bacteriological and molecular analysis. In parallel, the milk samples were also tested for residues of 15 OCs compounds using gas chromatographic analysis.

Results:

The examined herd showed a high prevalence of mastitis (37.5%) and Mycoplasma was identified as the main bacterial pathogen. OCs residues were detected in milk of 45 cows out of 160 with a higher incidence in mastitic (43.3%) than in healthy cows (19%). Further, the biochemical analysis of milk showed a significant drop in major electrolytes combined with a significant rise in blood-borne electrolytes (Na and Cl) and total protein. This was more extreme in the case of Mycoplasam mastitis compared to non-Mycoplasma mastitis. In addition, Mycoplasma mastitic milk revealed a high level of malondialdehyde associated with reduced antioxidant enzymes (glutathione peroxidase, superoxide dismutase and catalase), compared to non-Mycoplasma mastitis.

Conclusion:

Mycoplasma mastitis was shown to be associated with increased SCC and, in turn, appeared significantly correlated with increased biochemical changes in milk, indicating the serious impact of Mycoplasma mastitis on the dairy industry. Our data also show a strong correlation between increased SCC and biochemical changes in milk, suggesting that tested biochemical parameters might serve as potential biomarkers for the early detection of mastitis. The study also suggested a potential relationship between poisoning with OCs and susceptibility to bacterial udder infections. However, further studies are required to examine the immune status of a dairy herd in relation to the level of OCs in cow’s blood, as well as the water sources used, grass forage and soil.