DEVELOPMENT OF AN IN VITRO ASSAY TO EVALUATE ANTIMICROBIALS
Abstract
In vitro assays were developed using small intestinal contents from broilers fed
maltodextrin in preparation for shipping. This was done to establish an effective
bactericidal dose of allicin or lysozyme as ingredients in maltodextrin-based feed. The
antimicrobials were added to overnight cultures of gut material bacteria from
maltodextrin fed broilers and a pure culture of Salmonella. Following this, lysozyme was
incorporated into maltodextrin feed at 0, 10 and 20 g.kg-1 of feed and offered for 9 h to 4
pens of 20 birds per treatment. Bacterial numbers were analyzed using Proc Mixed of
SAS. Allicin and lysozyme inhibited Enterobacteriaceae and Clostridium perfringens,
respectively, in vitro. Lysozyme showed the most promise; it reduced bacterial numbers
in nutrient broth. Feeding lysozyme-enriched maltodextrin for 9 h inhibited bacilli growth
(P<0.05) when evaluated using next generation sequencing. Lysozyme was effective in
reducing specific bacterial numbers in the gut of market-aged broilers