Submitted to: American Society for Microbiology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2018
Publication Date: 6/9/2018
Citation: Yeh, H., Line, J.E., Hinton Jr, A. 2018. Characterization of Proteus mirabilis isolates from broilers [abstract]. American Society for Microbiology Meeting.
Interpretive Summary: none
Technical Abstract: Background: Proteus mirabilis is ubiquitous in the environment and is regarded as a part of the normal flora in human gastrointestinal tract. However, this bacterium is also an opportunistic human pathogen that causes urinary tract infections. Recently, this microorganism has been isolated from many food producing animals, including poultry. Moreover, reports have shown P. mirabilis can also cause foodborne illness in humans. While routinely monitoring broilers for two important foodborne pathogens (Salmonella and Campylobacter) in our study on broiler immunity, we observed that one group of the broilers excreted Proteus in their fecal droppings. Our interest in food safety in poultry products prompted us to characterize the molecular, biochemical, immunological, and antimicrobial properties of the Proteus isolates. Methods: Fecal droppings and cecal contents were collected and processed according to the standard protocol for bacterial isolation. Speciation based on biochemical reactions was carried out using a Biolog Microbial ID System kit, and the antimicrobial activity of the isolates were determined using a Phenotype MicroArray kit. Immunoblot assay was used to determine the immune status of broilers against P. mirabilis soluble proteins. A total of 10 P. mirabilis isolates were randomly selected for further characterization. Results: The selected isolates could grow at pH 6.0 and in 1% NaCl. In addition, the isolates were resistant to the following reagents: sodium lactate, troleandomycin, rifamycin SV, vancomycin, but sensitive to nalidixic acid, cefotaxime and novobiocin. Moreover, the CTX, ACC, VEB, CMY-1, BIC, NDM, qnrB and qnrD genes were detected by PCR amplification in all isolates. Sera from broilers harboring this bacterium reacted to the P. mirabilis soluble proteins, but not from litter- and age-matched P. mirabilis negative and SPF chickens, indicating that this bacterium could colonize chickens with a humoral immune response against this bacterium. Conclusion: This study may provide a rationale for further monitoring P. mirabilis in poultry production to determine whether P. mirabilis poses a potential threat to public health.