Journal of Natural Sciences Research www.iiste.org ISSN 2224-3186 (Paper) ISSN 2225-0921 (Online) Vol.8, No.6, 2018 46 Molecular Characterization and Diversity of Enteric Bacteria Isolated from Chicken Feeds Iheukwumere, Ikechukwu Harmony , 1* Olusola, Thomas Oduoye. 2 and Chude, Charles 3 1. Department of Microbiology, Faculty of Natural Sciences, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria 2. National Centre for Genetic Resources and Biotechnology (NACGRAB), PMB 5382, Moor Plantation, Ibadan, Nigeria 3 Department of Microbiology, Faculty of Natural Sciences, Chukwuemeka Odumegwu Ojukwu University, Anambra State, Nigeria Abstract This study focused on molecular characterization and diversity of enteric bacteria isolated from different brands of commercially produced chicken feeds sold in Anambra State. A total of 1,536 different chicken feed samples (starter, growers, finisher and layers) were collected from the consumers, retailers and wholesalers 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 diversity of the enteric bacteria was determined by carefully recording the number of occurrences of each identified isolate from the studied feed samples. 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 significantly (P<0.05) isolated from the feed samples. The organisms were detected most from the samples collected from the consumers while the samples from the wholesalers showed the least isolates. EC (60.49%) was the most predominant isolate, followed by SE (22.13%) and ST (16.52%). The occurrences of ES (0.66%) and SY (0.21%) were non significant (p>0.05). This study has revealed that EC, ST, ES, SY and SE were the enteric bacteria detected from the studied feed samples, of which EC was recorded most. Keywords: Molecular characterization, Enteric bacteria, Chicken Feeds, Diversity. INTRODUCTION Enteric bacteria belong to the family Enterobacteriaceae which is the largest of the medically important Gram- negative bacilli with more than 130 described species. These bacteria are found worldwide in soil, water and vegetation and are usually part of the normal flora of most animals and humans (Oguttu, et al., 2008).Many of the bacteria in this family can live in the gut without causing any health problems but some bacteria always cause infection with symptoms like vomiting, diarrhea and fever, People usually get infected with enteric bacteria as a result of poor unhygienic conditions, such as inadequate sanitation and contaminated food and drinking water, which is common in developing countries(Maciorowski et al., 2004). Infections with enteric bacteria are one of the major causes of childhood morbidity and mortality in the developing world today and acute infectious diarrhea is estimated to cause 2 million deaths each year (Maciorowski et al., 2004). Enteric pathogens can be disseminated to chicken through variety of sources. Several studies have linked contaminated feed to the occurrence of pathogens in chicken (Primm, 2008). Analysis of commercially manufactured feeds confirmed that both feed ingredients and dusts can be sources of Salmonella contamination in feed mills. Moreover, some pathogens such as Salmonella species can survive for long periods of time in feed of low water activity. Feed producers have used a variety of treatment to reduce pathogens in feed, including chemicals such as formic, hydrochloric, nitric, phosphoric, propionic, and sulphuric acids; isopropyl alcohol; formate and propionate salts; and trisodium phosphate have been evaluated. In determining their antimicrobial activity, consideration must be given to the effect of (Maciorowski et al., 2004). Despite different methods of control attributed to enteric bacterial infections, enteric bacteria mainly E. coli and Salmonella species remain the primary cause chicken diseases and death including human food poisoning worldwide. MATERIALS AND METHODS Study Area: Anambra State is a State in South-eastern Nigeria that has interstate boundaries with Delta State to the West, Imo State and Rivers State to the South, Enugu State to the East and Kogi State to the North. The State covers an area of 4,816.2 square kilometers and lies at Latitudes 6˚20' and 45.68’’ North; and Longitudes 7˚04' and 19.16’’east. It has a population of 4,177,828 (2006 census figure) with a population density of 860 per square kilometer. The temperature of the State ranges from 29˚C to 36.˚C with temperature range of 33.˚C. There are many human industrial activities within the State. The samples were collected randomly from Anam, Omor,