Role of growth morphology in the formulation of NaCl-based selective media for injury detection of Escherichia coli , Salmonella Typhimurium and Listeria innocua

2014 ◽  
Vol 64 ◽  
pp. 402-411 ◽  
Author(s):  
Estefanía Noriega ◽  
Eirini G. Velliou ◽  
Eva Van Derlinden ◽  
Laurence Mertens ◽  
Jan F.M. Van Impe
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Listeria Innocua ◽  
Growth Morphology ◽  
Selective Media

Effectiveness of a Laboratory-Scale Vertical Tower Static Chamber Steam Pasteurization Unit against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria innocua on Prerigor Beef Tissue†

2004 ◽  
Vol 67 (8) ◽  
pp. 1630-1633 ◽  
Author(s):  
DEANNA RETZLAFF ◽  
RANDALL PHEBUS ◽  
ABBEY NUTSCH ◽  
JAMES RIEMANN ◽  
CURTIS KASTNER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Cold Water ◽  
Laboratory Scale ◽  
Listeria Innocua ◽  
Steam Treatment ◽  
Escherichia Coli O157 ◽  
Tissue Samples ◽  
Before And After ◽  
Steam Pasteurization

A laboratory-scale vertical tower steam pasteurization unit was evaluated to determine the antimicrobial effectiveness of different exposure times (0, 3, 6, 12, and 15 s) and steam chamber temperatures (82.2, 87.8, 93.3, and 98.9°C) against pathogens (Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria innocua) inoculated onto prerigor beef tissue. Samples were collected and microbiologically analyzed immediately before and after steam treatment to quantify the effectiveness of each time-temperature combination. The 0-s exposure at all chamber temperatures (cold water spray only, no steam treatment) was the experimental control and provided ≤0.3 log CFU/cm2 reductions. Chamber temperatures of 82.2 and 87.8°C were ineffective (P > 0.05) at all exposure times. At 93.3°C, significant reductions (>1.0 log CFU/cm2) were observed at exposure times of ≥6 s, with 15 s providing approximately 1 log cycle greater reductions than 12 s of exposure. The 98.9°C treatment was consistently the most effective, with exposure times of ≥9 s resulting in >3.5 log CFU/cm2 reductions for all pathogens.

MERODIPLOIDY IN ESCHERICHIA COLI-SALMONELLA TYPHIMURIUM CROSSES: THE ROLE OF UNEQUAL RECOMBINATION BETWEEN RIBOSOMAL RNA GENES

Genetics ◽  
1985 ◽  
Vol 110 (3) ◽  
pp. 365-380
Author(s):  
Andreas F Lehner ◽  
C W Hill
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
E Coli ◽  
Unequal Recombination ◽  
Oric Region ◽  
Prime Factors ◽  
Transfer Origin ◽  
Rrn Operons ◽  
Prime 2

ABSTRACT Previous workers have shown that intergeneric crosses between Salmonella typhimurium and Escherichia coli produce a high proportion of merodiploid recombinants among the viable progeny. We have examined the unequal crossover event that was responsible for a number of intergeneric merodiploids. The merodiploids that we studied were all heterozygous for the metB–argH interval and were the products of intergeneric conjugal crosses. We found that when the S. typhimurium donor had its transfer origin closely linked to metB and argH, all recombinants examined were merodiploid, and they generally arose as F-prime factors. Many of these F-prime factors had been created by recombination between flanking rrn genes in the donor. When the S. typhimurium Hfr transfer origin was more distant from the selected markers, quite different results were obtained. (1) Depending on the donor, 19–47% of the recombinants that acquired the donor argH  + or metB  + genes were merodiploid for these loci, but none of the recombinants were F-prime. (2) A majority of the merodiploids had a novel (nonparental) rrn gene, indicating that unequal recombination between nonidentical rrn genes was a prevalent mechanism for establishing the merodiploidy. (3) Both tandem and nontandem duplications were found. (4) Some of the merodiploids duplicated E. coli genes in addition to acquiring S. typhimurium genes. (5) Some merodiploids contained the oriC region from each parent. Of a total of 118 intergeneric merodiploids characterized from all donors, 48 different genotypes were observed, and 38 of the 48 had one or more nonparental rrn operons.

The role of pulsed light spectral distribution in the inactivation of Escherichia coli and Listeria innocua on fresh-cut mushrooms

Food Control ◽  
2012 ◽  
Vol 24 (1-2) ◽  
pp. 206-213 ◽  
Author(s):  
Ana Y. Ramos-Villarroel ◽  
Nicoleta Aron-Maftei ◽  
Olga Martín-Belloso ◽  
Robert Soliva-Fortuny
Keyword(s):  
Escherichia Coli ◽  
Spectral Distribution ◽  
Listeria Innocua ◽  
Pulsed Light ◽  
Fresh Cut

scholarly journals Growth of Salmonella typhimurium SL5319 and Escherichia coli F-18 in mouse cecal mucus: role of peptides and iron

1990 ◽  
Vol 7 (2-3) ◽  
pp. 229-239 ◽  
Author(s):  
David P. Franklin ◽  
David C. Laux ◽  
Taffy J. Williams ◽  
Michael C. Falk ◽  
Paul S. Cohen
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium

Inactivation of Listeria innocua, Salmonella Typhimurium, and Escherichia coli O157:H7 on Surface and Stem Scar Areas of Tomatoes Using In-Package Ozonation†

2012 ◽  
Vol 75 (9) ◽  
pp. 1611-1618 ◽  
Author(s):  
XUETONG FAN ◽  
KIMBERLY J. B. SOKORAI ◽  
JÜRGEN ENGEMANN ◽  
JOSHUA B. GURTLER ◽  
YANHONG LIU
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Treatment Time ◽  
Listeria Innocua ◽  
Escherichia Coli O157 ◽  
Bacterial Reduction ◽  
Negative Effects ◽  
E Coli ◽  
Storage Study ◽  
Proportional Increase

A novel in-package ozonation device was evaluated for its efficacy in inactivating three microorganisms (viz., Listeria innocua, attenuated Salmonella Typhimurium, and Escherichia coli O157:H7) on tomatoes and for its effect on fruit quality. The device produced ozone inside sealed film bags, reaching a concentration of 1,000 ppm within 1 min of activation. The three bacterial cultures were inoculated onto either the smooth surface or the stem scar areas of the tomatoes, which were then sealed in plastic film bags and subjected to in-package ozonation. L. innocua on tomatoes was reduced to nondetectable levels within 40 s of treatment on the tomato surface, with inactivation of ca. 4 log CFU per fruit on the stem scar area. An increase in treatment time did not result in a proportional increase in bacterial reduction. For E. coli O157:H7 and Salmonella, there was little difference (<1 log) in the effectiveness of the system when comparing surface and scar-inoculated bacteria. Both bacteria were typically reduced by 2 to 3 log CFU per fruit after 2- to 3-min treatments. No negative effects on fruit color or texture were observed during a 22-day posttreatment storage study of ozone-treated tomatoes. These results suggest that the three bacteria responded differently to ozonation and that in-package ozonation may provide an alternative to chemical sanitizers commonly used by the industry.

scholarly journals Role of Lipopolysaccharide and Complement in Susceptibility of Escherichia coli and Salmonella typhimurium to Non-immune Serum

Microbiology ◽  
1988 ◽  
Vol 134 (4) ◽  
pp. 1009-1016 ◽  
Author(s):  
J. M. Tomas ◽  
B. Ciurana ◽  
V. J. Benedi ◽  
A. Juarez
Keyword(s):  
Escherichia Coli ◽  
Salmonella Typhimurium ◽  
Immune Serum
Sign in / Sign up

Export Citation Format

Share Document