Aims: The effect of a lactic acid producing bacterial (LAB) inoculant on the elimination of Escherichia coli O157:H7 from barley forage was assessed.
Methods And Results: Triplicate mini-silos were prepared for four treatments and six sampling times (1, 3, 7, 15, 30 and 42 d post-ensiling). The treatments were (i) 10(5) cfu g(-1) Pediococcus pentosaceus and Propionibacterium jenzenii (P2); (ii) 10(5) cfu g(-1) E. coli O157:H7 strain 3081 and 10(5) cfu g(-1) E. coli Biotype 1 strains 719IE10, 719IE14 and 614ME49 (EC); (iii) P2 + EC; and (iv) the control (sterile distilled water). Triplicate mini-silos were opened at each sampling time for pH, volatile fatty acid (VFA) and lactate determinations and E. coli, E. coli O157:H7 and LAB were enumerated. On d 3 and 7, numbers of E. coli O157:H7 in P2 + EC were significantly lower than in EC (P < 0;05). Escherichia coli O157:H7 was not detected in P2 + EC and EC at 7 and 15 d post-ensiling, respectively. On d 15 through 42, E. coli Biotype 1 was not detected in P2 + EC or EC. Populations of LAB were higher in P2 and P2 + EC than in the control and EC on d 3 and 7 (P < 0.05). After 3 d of ensiling, lactate levels were higher (P < 0.05) and pH was lower (P < 0.05) in P2 and P2 + EC as compared to the control and EC. Bacteriocins of P2 were not found to be inhibitory to E. coli O157:H7 using the agar-spot procedure. Escherichia coli O157:H7 inoculated into the control silage at a level of 10(3) cfu g(-1) and exposed to aerobic conditions at 22 degrees C was not detected after 1 d and remained undetectable for the 28 d exposure period.
Conclusions: Silage inoculant P2 increased lactate levels and decreased pH more rapidly during ensiling, which appeared to hasten the elimination of E. coli O157:H7 from the silage.
Significance And Impact Of The Study: Results emphasize the importance of adequate ensiling since E. coli O157:H7 may be maintained and spread among cattle through feed.
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http://dx.doi.org/10.1046/j.1365-2672.2002.01695.x | DOI Listing |
Int J Biol Macromol
October 2024
Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Shahrekord University, Shahrekord, Iran.
Foodborne Pathog Dis
July 2024
Facultad de Medicina Veterinaria y Agronomía, Universidad de Las Américas, Concepción, Chile.
Zhonghua Liu Xing Bing Xue Za Zhi
August 2022
Department of Epidemiology, College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
To evaluate the typing and clinical application effect based on clustered regularly interspaced short palindromic repeats (CRISPRs), serotype, and Multilocus Sequence Typing (MLST). The spacers, serotype and sequence type (ST) were obtained with CRISPRsFinder, SeroTypeFinder and MLST. PCR was used to amplify the CRISPRs, and the spacers were used to predict serotype and ST, then comparing with the serotype and ST.
View Article and Find Full Text PDFRSC Adv
January 2022
College of Artificial Intelligence, Guangdong Mechanical & Electrical Polytechnic Guangzhou 510550 P. R. China +86-20-36552429 +86-20-36552429.
Rapid measurement of waterborne bacterial viability is crucial for ensuring the safety of public health. Herein, we proposed a colorimetric assay for rapid measurement of waterborne bacterial viability based on a difunctional gold nanoprobe (dGNP). This versatile dGNP is composed of bacteria recognizing parts and signal indicating parts, and can generate color signals while recognizing bacterial suspensions of different viabilities.
View Article and Find Full Text PDFCan J Microbiol
September 2021
Department of Food Engineering, Beytepe, Hacettepe University, Ankara, Turkey.
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