Regulation of hydrogen peroxide defenses by Fecal indicator bacteria and E. coli O157: H25
Cattle feces was collected from a commercial farm in northeast Georgia and made into a filter-sterilized extract referred to as cattle fecal extract (CFE). CFE was diluted to represent water DOM concentrations resulting from high fecal input, and exposed to artificial sunlight for 12 h. Sunlight irradiated CFE spiked water (ISW) and non-irradiated CFE spiked water (NSW) were separately inoculated with mid-logarithmic phase aliquots of individual strains of E. coli C3000 (American Type Culture Collection (ATCC) strain 15597), E. faecalis (ATCC 29212) and E. coli O157:H7 strain B6914 (~106 colony forming unit (CFU) mL-1). Microcosms were monitored periodically in the dark for FIB and pathogen growth, H2O2, whole transcriptome changes for up to 24 h. Total RNA was isolated at post-inoculation, 6, 12, and 24h and enriched for mRNA before RNA-seq. RNA-sequencing was performed on an Illumina NextSeq 500 platform, using a NextSeq (150 cycles) Mid Output Flow Cell and 75 bp paired end sequencing