JOURNAL OF AGRICULTURE & SOCIAL SCIENCES ISSN Print: 1813–2235; ISSN Online: 1814–960X 07–262/ZIP/2008/04–2–77–80 http://www.fspublishers.org Full Length Article To cite this paper: Ahmad, S., M. Ashraf, M. Siddique, F. Mehmood, M. Arshad and H.A. Khan, 2008. Biofilm formation and drinking water quality in relation to Escherichia coli at commercial poultry farms. J. Agri. Soc. Sci., 4: 77–80 Biofilm Formation and Drinking Water Quality in Relation to Escherichia coli at Commercial Poultry Farms SUJJAD AHMAD 1 , MUHAMMAD ASHRAF, MUHAMMAD SIDDIQUE, FAZAL MEHMOOD, MUHAMMAD ARSHAD AND HAIDER ALI KHAN Department of Veterinary Microbiology, University of Agriculture, Faisalabad, Pakistan Veterinary Pathology, University of Agriculture, Faisalabad, Pakistan 1 Corresponding author’s e-mail: sujjadsial@yahoo.com ABSTRACT Biofilms are dense aggregates of surface adherent micro-organisms embedded in a poly saccharide matrix. The most alarming is the presence and multiplication of opportunistic pathogens such as Eschericlia coli found in biofilms. The present study was designed to determine the presence of E. coli in biofilm and water samples at various commercial poultry farms and to analyse factors involved in the formation of biofilm. A total of 120 biofilm and water samples were collected from inside surface of water supply network from commercial broiler and layer poultry farms in and around Faisalabad and Jhang. History of the flocks was recorded on a pre-designed questionnaire. E. coli was isolated form biofilm and water samples. Out of 60 biofilms samples 58 (96.6%) and out of 60 water samples 50 (83.3%) samples was found positive for E. coli. The quantity of bacteria in the samples was determined by acridine orange direct count and viable count. Maximum acridine orange count in biofilm and water samples was recorded 2.86×0 9 and 1099×10 7 mL -1 , respectively. Maximum viable count was 1.61×10 9 and 1.05× 10 3 mL -1 in biofilm and water samples, respectively. Biofilm contributes many species of bacteria but major one is E. coli. Key Words: Escherichia coli; Biofilm; Water quality; Chlorination; Bacterial count INTRODUCTION A supply of good quality water is essential for health and performance of the chicken since it constitutes 60 to 80% of live body weight (Anjum et al., 1989). Biofilm is a serious threat to decrease the production as well as increase the onset of diseases. Biofilm is defined as dense aggregates of surface-adherent microorganisms embedded in a polysaccharide matrix (Siller et al., 1972). Biofilm development is a result of successful attachment and subsequent growth of microorganisms on a surface. Biofilm harbours colonies of pathogenic bacteria. Biofilm formation is a multi step process whereby bacteria, adhere to equipment surfaces, surround themselves with a protective layer of polysaccharides and grow into a network of microcolonies and water channels. The rate of biofilm formation and its release into a distribution system can be affected by many factors including surface characteristics, availability of nutrients and flow velocities. Biofilms appear to grow until the surface layers begin to slough off into the water (Geldreich & Rice, 1987). The factors influencing biofilm formation include microbial nutrients (e.g., the concentration of carbon, nitrogen & phosphorus) in water, temperature, pipe materials, disinfectants, bacteria in water and the hydraulic regime in drinking water supply systems (Block et al., 1995). Bacteria can be introduced into water from internal and external sources. The situation where the increase of bacteria is due to internal growth or after growth of bacteria is associated with the formation of biofilms. Several investigators have shown that the multiplication of micro- organisms in biofilms along the distribution systems results in the deterioration of the bacteriological quality of drinking water, the development of odour or colour as well as the acceleration of the phenomenon of corrosion within the pipe network (Nagy & Olson, 1985). The most alarming results of biofilm formation are the presence and multiplication of pathogenic and opportunistic pathogens such as Escherichia coli, Pseudomonas, Mycobacteria, Campylobacter, Klebesiella, Aeromonas, Legionella spp., Helicobacter pylori and Salmonella typhimurium occurring within the biofilms (Engle et al., 1980; Wadowsky et al., 1982; Burke et al., 1984; Mackey et al., 1998). Therefore, the present study was designed to determine the presence of E. coli in biofilm and water samples at various commercial poultry farms and to analyse factors involved in the formation of biofilm. MATERIALS AND METHODS Collection of samples. A total of 120 (60 biofilm, 60 water) samples were collected from inside surface of water supply