Hollow-fiber ultrafiltration for the concentration and simultaneous recovery of multiple pathogens in contaminated foods.
We investigated the possibility of using hollow-fiber ultrafiltration (HUF) for the simultaneous recovery of multiple microorganisms in food samples. MS2 bacteriophage, E. coli, Bacillus subtilis spores, and murine norovirus (MNV) were each inoculated into 5 liters of either distilled water (DW) or glycine elution buffer and then concentrated using hollow-fiber polysulfone ultrafilters. The resulting concentrates were further analyzed by either cultivation or TaqMan real-time reverse transcription PCR assay. The overall average recovery rates were 7.1% in DW and 17.1% in glycine elution buffer. When the virus, vegetative bacteria, and bacterial spores were simultaneously inoculated into DW, glycine, or Tris-HCl elution buffers, on average 16.8% of inoculated microorganisms were recovered by HUF. The addition of 3% beef extract blocking buffer to HUF increased the total recovery rate to 46.1%, with incremental recovery rates increasing sharply for B. subtilis spores and MNV. Use of HUF resulted in E. coli recovery rates of 68.0% on lettuce and 66.2% on ham and MNV recovery rates of 1.5% on lettuce and 5.8% on ham. Our study demonstrates that HUF can be effective at simultaneously recovering and concentrating diverse bacterial and viral pathogens from foods.
Kim
Hee-Yeon
HY
Department of Environmental Health and Institute of Health and Environment, School of Public Health, Seoul National University, Seoul, Korea.
Park
Hyeun-Jin
HJ
Ko
Gwangpyo
G
D000818:Animals; D001412:Bacillus subtilis / Q000302:isolation & purification*; D002417:Cattle; D003469:Culture; D004926:Escherichia coli / Q000302:isolation & purification*; D005516:Food Microbiology; D005998:Glycine; D018545:Lactuca / Q000382:microbiology; D017909:Levivirus / Q000302:isolation & purification*; D008460:Meat / Q000382:microbiology; D029322:Norovirus / Q000302:isolation & purification*; D013171:Spores, Bacterial / Q000302:isolation & purification; D013552:Swine; D014462:Ultrafiltration / Q000379:methods*; D014867:Water; D014871:Water Microbiology
D014867:Water; D005998:Glycine