Isolation of fluconazole-tolerant micromycetes onto different cultivation media

Nutrient concentrations affect the antimicrobial resistance profiles of cattle manures

Antimicrobial resistance (AMR) in cattle is widespread because of the increased use of antibiotics to combat microbial diseases and enhance milk production. The cattle excreta released into the environment can be a potent source of contamination in spreading antibiotic resistance, especially upon its application in agriculture. However, the correlation of AMR profile of manure with other physico-chemical parameters is limited. Therefore, the study aimed to generate AMR profiles for manure samples collected from 25 different sites of two agriculturally important states in India, Madhya Pradesh and Uttar Pradesh. Samples were tested for physico-chemical parameters, viz., electrical conductivity, pH, total nitrogen (N), total phosphorus (P), and total potassium (K). Bacterial community analysis was done by culture-dependent and culture-independent methods. The influence of feeding practices, nutrient concentration, and bacterial abundance on antibiotic resistance profiles was observed in collected manure samples. Manures of intensive feeding animals harbored highly resistant profiles of bacteria as compared to natural grazing cattle.

Survival of Campylobacter jejuni in waterborne protozoa

The failure to reduce the Campylobacter contamination of intensively reared poultry may be partially due to Campylobacter resisting disinfection in water after their internalization by waterborne protozoa. Campylobacter jejuni and a variety of waterborne protozoa, including ciliates, flagellates, and alveolates, were detected in the drinking water of intensively reared poultry by a combination of culture and molecular techniques. An in vitro assay showed that C. jejuni remained viable when internalized by Tetrahymena pyriformis and Acanthamoeba castellanii for significantly longer (up to 36 h) than when they were in purely a planktonic state. The internalized Campylobacter were also significantly more resistant to disinfection than planktonic organisms. Collectively, our results strongly suggest that protozoa in broiler drinking water systems can delay the decline of Campylobacter viability and increase Campylobacter disinfection resistance, thus increasing the potential of Campylobacter to colonize broilers.