Submitted to: Anaerobe
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/14/2007
Publication Date: 8/22/2007
Citation: Ramlachan, N., Andrews, K., Anderson, R.C., Nisbet, D.J. 2007. Characterization of an antibiotic resistant Clostridium hathewayi strain from a continuous flow exclusion chemostat culture derived from the cecal contents of a feral pig. Anaerobe. 13:153-160. Interpretive Summary: The study of intestinal bacteria of pigs and other livestock species has been aided by using a continuous flow liquid culture system as a laboratory model of the gut. Such research has resulted in several commercial products used for preventing opportunistic pathogenic bacteria taking hold in the gut. We produced a liquid culture system from a wild pig in order to make comparisons to an already established system in our lab from a farm-raised pig. We identified and characterized a strain of Clostridium hathewayi, which is a strain similar to those known to cause blood infections in both animals and humans, from the intestinal contents of the wild pig. This is important as wild pigs may be a source of transmission of antibiotic resistant strains of bacteria to other livestock species and humans.
Technical Abstract: The chemostat model has been an important tool in studying intestinal microflora. To date, several competitive exclusion products have been developed from such studies as prophylactic treatment against pathogenic bacteria. A continuous flow chemostat model of a feral pig was developed using inocula from the cecal contents of a wild boar caught in East Texas. Several strains of antibiotic-sensitive bacteria were isolated including Bacteroides, Lactobacillus, Enterococcus and Clostridium sp. This study reports on the characterization of a multidrug-resistant Clostridum hathewayi strain that was isolated from this feral pig's cecal contents maintained in a continuous flow chemostat system showing high resistance to carbapenems and macrolides (including the growth promoter tylosin) Clostridium hathewayi has been documented to be pathogenic to both humans and animals. Feral pigs may be a potential source of antibiotic resistant strains and may pose potential risk to domestic species. Characterizing the intestinal microflora and antibiotic resistant strains found in feral animals will allow us to elucidate its prevalence and pathogenicity in potential sources of resistant pools of bacteria.