Hygienic Studies on Biofilms in Drinking Water Systems in Poultry Farms: Isolation, Molecular Identification, and Antibiotic Sensitivity

Abstract

| In poultry production, drinking water must be free from pathogens that pose a risk for infection. Biofilms are significant contributors to water contamination with pathogens, and aid in the genetic exchange among bacterial populations that cause antibiotic resistance. The study included four-layer chicken houses receiving the same water source: A growing pullet house with iron water pipes and three production layer houses with polyvinyl chloride (PVC) water pipes. Biofilm samples were collected, during February 2020, by swabbing the inner surfaces of drinking water pipes. The heterotrophic bacterial counts were determined. Afterwards, colonies were purified and molecularly identified using the 16S rRNA by PCR test. A total of 31 antimicrobials were used for antibiotic sensitivity testing of the bacterial isolates. In the PVC pipes, more bacterial densities were found than in the iron pipes (2×10 19 and 2×10 12 colony forming units/ml, respectively). Pseudomonas , Enterococcus , Staphylococcus , and Sphingopyxis were identified from iron pipes, while Acinetobacter , Pseudomonas , and Bacillus were confirmed from PVC pipes. Multidrug resistance to at least three antibiotic groups was identified in 67% of the isolates. Staphylococcus , Enterococci , Sphingopyxis , Bacillus , and Acinetobacter were found to be originated from water sources highly contaminated with antibiotics overuse. While all Pseudomonas strains originated from water environments free from antibiotics contamination. In terms of bacterial density and antibiotic resistance patterns, biofilms possess a significant role in harboring and disseminating pathogenic strains leading to production problems in poultry. So, programs for the prevention and control of biofilm buildup in poultry drinking systems are required.