Investigation of bacterial resistance to hatchery disinfectants

Three commercial chicken hatcheries were sampled for environmental bacteria. Isolated bacteria were tested for resistance to commercial preparations of quaternary ammonia, phenolic, and glutaraldehyde liquid disinfectants. Bacterial isolates were exposed to several disinfectant dilutions bracketing the dilutions recommended by the manufacturer for 5-, 10-, and 15-min exposure periods before subculturing to broth medium. Approximately 8% of the isolates from two of three hatcheries were resistant to disinfectant concentrations at and above the manufacturers recommended dilution and time of exposure. Resistant bacteria included Serratia marcescens, Bacillus cereus, Bacillus thuringiensis, Bacillus badius, Enterococcus faecalis, Enterococcus faecium, Pseudomonas stutzeri, and Enterobacter agglomerans.