When the solution becomes the problem: a review on antimicrobial resistance in dairy cattle.

Antibiotics' action, once a 'magic bullet', is now hindered by widespread microbial resistance, creating a global antimicrobial resistance (AMR) crisis. A primary driver of AMR is the selective pressure from antimicrobial use. Between 2000 and 2015, antibiotic consumption increased by 65%, reaching 34.8 billion tons, 73% of which was used in animals. In the dairy cattle sector, antibiotics are crucial for treating diseases like mastitis, posing risks to humans, animals and potentially leading to environmental contamination. To address AMR, strategies like selective dry cow therapy, alternative treatments (nanoparticles, phages) and waste management innovations are emerging. However, most solutions are in development, emphasizing the urgent need for further research to tackle AMR in dairy farms.

Antibiotics are becoming less effective at fighting infections because of antimicrobial resistance (AMR). This phenomenon is mainly caused by the abuse and misuse of antibiotics in both human and veterinary medicine. In the dairy cow industry, the use of antibiotics to treat diseases is a big concern. Ways to tackle this include the promotion of the responsible use of antibiotics, the development of alternative treatments and the discovery of better methods to deal with animal waste. However, much of these are still in development.

Purification and crystallographic studies of a putative carbohydrate-binding module from the Ruminococcus flavefaciens FD-1 endoglucanase Cel5A.

Ruminant herbivores meet their carbon and energy requirements from a symbiotic relationship with cellulosome-producing anaerobic bacteria that efficiently degrade plant cell-wall polysaccharides. The assembly of carbohydrate-active enzymes (CAZymes) into cellulosomes enhances protein stability and enzyme synergistic interactions. Cellulosomes comprise diverse CAZymes displaying a modular architecture in which a catalytic domain is connected, via linker sequences, to one or more noncatalytic carbohydrate-binding modules (CBMs). CBMs direct the appended catalytic modules to their target substrates, thus facilitating catalysis. The genome of the ruminal cellulolytic bacterium Ruminococcus flavefaciens strain FD-1 contains over 200 modular proteins containing the cellulosomal signature dockerin module. One of these is an endoglucanase Cel5A comprising two family 5 glycoside hydrolase catalytic modules (GH5) flanking an unclassified CBM (termed CBM-Rf2) and a C-terminal dockerin. This novel CBM-Rf2 has been purified and crystallized, and data from cacodylate-derivative crystals were processed to 1.02 and 1.29 Šresolution. The crystals belonged to the orthorhombic space group P212121. The CBM-Rf2 structure was solved by a single-wavelength anomalous dispersion experiment at the As edge.