Toxicological Study and Antibacterial Activities of Effectively Validated Medicinal Plants against Enteric Bacteria Isolated from Chicken Feeds

Abstract

This study focused on the toxicological study and antibacterial activities of effectively validated medicinal plants against enteric bacteria isolated from chicken feeds sold in Anambra State. A total of 1,536 different chicken feed samples (starter, growers, finisher and layers) were collected from open markets and shops and screened for the presence of enteric bacteria using pour plate technique. The isolates were characterized and identified using their colony descriptions, biochemical and molecular characteristics. The toxicological study of the plant extracts was investigated by exposing the chicks to various concentrations of the extracts for a period of 4 weeks.  The isolates were screened for their in vitro susceptibility to medicinal plant extracts (Gongronema latifolium, Piper guineense, Xylopia aethiopica and Zingiber officinale) at 500mg/ml using agar well-diffusion method. The result of this study revealed that Escherichia coli O157:H7 SS52 (EC), Salmonella serovar Typhimurium U288 (ST), Escherichia coli SEC470 (ES), Salmonella serovar Enteritidis YU39 (SY) and Salmonella serovar Enteritidis FM366 (SE) were isolated from the feed samples. The toxicological study revealed that 0.5 ml of the plant extracts increased the white blood cell indices, and there was no toxic effect on the haematological indices and body organs. The in vitro activity showed that the test extracts significantly (P<0.05) inhibited the test organisms and Zingiber officinale (ZO) extract proved to be most significant (P<0.05) against the tested organisms. This study has revealed that EC, ST, ES, SY and SE were the enteric bacteria detected from the studied feed samples. The tested plant extracts have proved to be safe and effective against the isolates, of which Zingiber officinale (ZO) extract showed the most pronounced activity.

Keywords: Toxicological study, Medicinal plants, Enteric bacteria, Chicken Feeds.