Hygienic Studies on Biofilm in Poultry Farms: Its Role and Possible Means of Control

Abstract

The current study was conducted through two experiments. The first experiment included four-layer chicken houses receiving untreated ground water: A growing pullet house with iron water pipes and three production layer houses with Polyvinyl chloride (PVC) water pipes. Biofilm samples were collected by swabbing the inner surfaces of drinking water pipes. Then the heterotrophic bacterial counts were determined according to the standard protocols of the American Public Health Associations. Afterwards, colonies were purified and molecularly identified using the 16S rRNA. Then, the antibiotic sensitivity of the biofilm bacterial isolates was assessed using a total of 31 antimicrobials representing 14 antibiotic groups. Results were interpreted following the Clinical and Laboratory Standards Institute (CLSI) guidelines (CLSI, 2020). Multiple Antibiotic Resistance Index (MARI) was estimated. A value above 0.2 indicates that the bacteria came from a potentially contaminated water source where antibiotics are commonly applied. In the second experiment, two trials were conducted to determine the efficacy of disinfectants against biofilm-forming bacteria; the first trial was for testing the disinfectants to inhibit the growth of biofilm-forming bacteria as plankton (single species bacteria). The second trial was for assessing the effectiveness of disinfectants on biofilm consortia (multispecies bacterial