Relative gene expression in acid-adapted Escherichia coli O157:H7 during lactoperoxidase and lactic acid challenge in Tryptone Soy Broth.

PCR detection of Escherichia coli O157:H7 directed from slaughtered cattle in Shiraz, Iran

  Escheric hia coli O157:H7 lives in the intestines of healthy cattle, and can contaminate meat during slaughtering pr actices . Detection of the low infectious dosage of bacterium requires a sensitive method. We developed polymerase chain reaction (PCR) assays to detect the gene Stx2 irrespective of the bacterial serotype. In this study, the detection limit of the PCR protocol in detecting Stx...

Thermal tolerance of acid-adapted and non-adapted Escherichia coli O157:H7 and Salmonella in ground beef during storage.

Thermal tolerance of acid-adapted Escherichia coli O157:H7 or Salmonella in ground beef was evaluated during storage at 4 degrees C or -20 degrees C. Both pathogens were adapted to acidic conditions (pH approximately 4.6) by growing in tryptic soy broth supplemented with 1% glucose. A five-strain cocktail of E. coli O157:H7 or Salmonella was grown separately in TSB (pH approximately 6.6) and TS...

Effect of Lactoperoxidase System and Escherichia Coli O157:h7 Growth on Acid-production by Single Strain and Indigenous Lactic Acid Bacteria in Goat Milk

The effect of acid adaptation conditions on heat resistance of Escherichia coli O157: H7.

The objective of this study was to determine the effect of acid adaptation conditions on heat resistance of E. coli O157: H7 932. E. coli O157: H7 was adapted to acid by exposing the cells to pH 4.5 (2h), pH 5.0 (1 h), and pH 5.5 (1 h) in tryptic soy broth. D and z values of the acid adapted and control cultures at 54 degrees C, 56 degrees C, and 58 degrees C were determined in E buffer. The he...

A Study on Selective Broths and Agar Media for the Isolation of Escherichia coli O157:H7 Serotype

Modified tryptic soy broth, lauryl sulfate tryptose broth, modified EC broth, sorbitol MacConkey agar and Fluorocult E. coli O157 agar were tested for the recovery of 3 strains of Escherichia coli O157:H7 against E. coli type 1 and Citrobacter freundii as common competitive microflora of raw meat products. Two-stepped trials showed that modified EC broth and lauryl sulfate tryptose broth were s...