Dynamics of indicator bacteria and the presence of foodborne pathogenic bacteria in sediments of Conococheague creek, Pennsylvania

Authors: BOOMER, ASHLEY - Oak Ridge Institute For Science And Education (ORISE); Yin, Hsin Bai; CHEN, CHI-HUNG - Oak Ridge Institute For Science And Education (ORISE); PANKO GRAFF, CHRISTINA - Wilson College; HARRINGER, DANA - Wilson College; Patel, Jitu

Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 3/21/2022
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Introduction: Bacterial pathogens in sediment beds may re-suspend into water body upon disturbance of sediment microbial reservoirs. Prevalence pattern of microbial contamination in sediments represent valuable inputs in predicting the microbial quality of water for irrigation. Methods: The objective of this study was to determine the populations of fecal indicator bacteria and the prevalence of pathogenic bacteria including Salmonella, E. coli O157:H7, and Listeria monocytogenes in sediments of Conococheague creek, PA. Sediment samples (N=416) were collected every week from 3 different sites along the creek during January-December 2021. The samples (10 g) were mixed with buffer peptone water (30 ml), hand massaged for 1 min and then sonicated for 2 min, followed by plating on VRB, mFC, and TBX agar plates for enumerations of total coliforms, fecal coliforms, and generic E. coli, respectively, or enriched to detect the presence of Salmonella, E. coli O157:H7, and L. monocytogenes by real-time quantitative PCR. Moisture content of sediment samples was measured, and the bacterial populations were expressed as log CFU/g dry weight. Results: An average of 3.93 log, 2.37 log, and 1.53 log CFU/g of total coliforms, fecal coliforms, and generic E. coli was recovered from the sediment samples collected during this period. Populations of total coliforms were stable throughout the entire collection period, whereas populations of fecal coliforms and generic E. coli in sediment samples were lower during winter (2.2 and 1.3 log CFU/g) than in fall season (2.8 and 1.9 log CFU/g), respectively. Salmonella, E. coli O157:H7, and L. monocytogenes were isolated from 15, 1, and 155 samples, representing the prevalence of these pathogens at 6%, 0.5%, and 73%, respectively. More than 70% of Salmonella and L. monocytogenes isolates were obtained from the sediment samples collected during summer/fall season. Significance: The information about the microbial dynamics in the sediments of Conococheague creek, PA and is helpful to farmers using the creek water for irrigation. The data can be used in modeling to predict microbial quality of creek water.