Antimicrobial sensitivity testing of Australian isolates of Bordetella avium and the Bordetella avium-like organism

The in vitro sensitivity of 16 Australian isolates of Bordetella avium and 15 isolates of B. avium -like organisms to 11 antimicrobial agents or combinations of agents was determined using a microtitre plate system to establish minimal inhibitory concentrations. All the B. avium isolates were sensitive to ampicillin but resistant to erythromycin, lincomycin, spectinomycin, sulfamethoxazole, trimethoprim and lincomycin with spectinomycin. Most of the B. avium isolates were sensitive to tetracycline and resistant to streptomycin and sulfadiazine. All the B. avium -like isolates were sensitive to sulfamethoxazole and trimethoprim-sulfamethoxazole

The role of the commensal gut microbial community in broiler chickens

To understand the relationship between the gastrointestinal inhabiting microbial community and broiler health, a literature review is presented. The available information on the development of gut microbial community, the relationship between commensal microflora and digestive function, the role of gut microorganisms on competitive exclusion of chickens against pathogens, and modulation of the gut microbial community by addition of prebiotics to the diet is summarized. Gut dominant microbial communities become more complex as broilers grow older. The establishment of the dominant bacterial community is affected by dietary and host-related factors. Dietary prebiotics can modulate bacterial community shift towards non-harmful bacteria, which is beneficial for the health of broiler chickens. Gut commensal microorganisms play an important role in the prevention of colonization by pathogens in the gastrointestinal tract of chickens, a process known as competitive exclusion. In conclusion, the dilemma caused by the forthcoming ban of antibiotics feed additives and need to maintain the intestinal health of broiler chickens, has produced an enormous interest in finding alternatives. Modulating the intestinal microbial community in a healthy direction, by dietary ingredients such as prebiotics, could be a good solution