Effect of yogurt-based marinade combined with essential oils on the behavior of Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella spp. in camel meat chunks during storage

2021 ◽  
Vol 343 ◽  
pp. 109106
Author(s):  
Tareq M. Osaili ◽  
Fayeza Hasan ◽  
Dinesh Kumar Dhanasekaran ◽  
Reyad S. Obaid ◽  
Anas A. Al-Nabulsi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Essential Oils ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Camel Meat

Microbiological Quality of Retail Imported Unprepared Whole Lettuces: A PHLS Food Working Group Study

1999 ◽  
Vol 62 (4) ◽  
pp. 325-328 ◽  
Author(s):  
C. LITTLE ◽  
D. ROBERTS ◽  
E. YOUNGS ◽  
J. de LOUVOIS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Microbiological Quality ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Shigella Spp ◽  
Natural Microflora ◽  
Production Practices ◽  
Campylobacter Spp

A study of imported unprepared whole lettuces sampled from supermarkets, greengrocers, shops, and market stalls found that all were of acceptable microbiological quality. Twenty-seven out of 151 (18%) imported lettuce samples had Enterobacteriaceae levels of 104 CFU/g or more. However, these bacteria that constitute part of the natural microflora of unprepared vegetables may also be derived from the soil and/or by poor handling. The pathogens, Salmonella spp., Shigella spp., Campylobacter spp., Escherichia coli O157:H7, Vibrio cholerae, Listeria monocytogenes, and also Escherichia coli, an indicator of fecal contamination, were not detected in any imported lettuces, indicating that hygiene, harvesting, and production practices were good. Imported lettuces with Enterobacteriaceae levels of 104 CFU/g or more varied with type of retail premises and the temperature at which the lettuces were displayed. Samples from greengrocers, shops, and market stalls were more likely to contain Enterobacteriaceae at levels in excess of 104 CFU/g than those from supermarkets.

Mechanism of Action of Spanish Oregano, Chinese Cinnamon, and Savory Essential Oils against Cell Membranes and Walls of Escherichia coli O157:H7 and Listeria monocytogenes

2006 ◽  
Vol 69 (5) ◽  
pp. 1046-1055 ◽  
Author(s):  
MOUNIA OUSSALAH ◽  
STÉPHANE CAILLET ◽  
MONIQUE LACROIX
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Essential Oils ◽  
Intracellular Ph ◽  
Cell Membranes ◽  
Escherichia Coli O157 ◽  
Electronic Microscopy ◽  
Cinnamon Oil ◽  
E Coli ◽  
Atp Concentration

The mechanism of the antimicrobial action of Spanish oregano (Corydothymus capitatus), Chinese cinnamon (Cinnamomum cassia), and savory (Satureja montana) essential oils against cell membranes and walls of bacteria was studied by the measurement of the intracellular pH and ATP concentration, the release of cell constituents, and the electronic microscopy observations of the cells when these essential oils at their MICs were in contact with Escherichia coli O157:H7 and Listeria monocytogenes. E. coli O157:H7 and L. monocytogenes, two pathogenic foodborne bacteria, were used as gram-negative and gram-positive bacterial models, respectively. Treatment with these essential oils at their MICs affected the membrane integrity of bacteria and induced depletion of the intracellular ATP concentration. Spanish oregano and savory essential oils, however, induced more depletion than Chinese cinnamon oil. An increase of the extracellular ATP concentration was observed only when Spanish oregano and savory oils were in contact with E. coli O157:H7 and L. monocytogenes. Also, a significantly higher (P ≤0.05) cell constituent release was observed in the supernatant when E. coli O157:H7 and L. monocytogenes cells were treated with Chinese cinnamon and Spanish oregano oils. Chinese cinnamon oil was more effective to reduce significantly the intracellular pH of E. coli O157:H7, whereas Chinese cinnamon and Spanish oregano decreased more significantly the intracellular pH of L. monocytogenes. Electronic microscopy observations revealed that the cell membrane of both treated bacteria was significantly damaged. These results suggest that the cytoplasmic membrane is involved in the toxic action of essential oils.

Growth of Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus on Cheese during Extended Storage at 25°C

2014 ◽  
Vol 77 (8) ◽  
pp. 1275-1288 ◽  
Author(s):  
WAN MEI LEONG ◽  
RENAE GEIER ◽  
SARAH ENGSTROM ◽  
STEVE INGHAM ◽  
BARBARA INGHAM ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Listeria Monocytogenes ◽  
Water Activity ◽  
Titratable Acidity ◽  
Study Data ◽  
Escherichia Coli O157 ◽  
Salmonella Spp ◽  
Require Time ◽  
And Staphylococcus Aureus

Potentially hazardous foods require time/temperature control for safety. According to the U.S. Food and Drug Administration Food Code, most cheeses are potentially hazardous foods based on pH and water activity, and a product assessment is required to evaluate safety of storage >6 h at 21°C. We tested the ability of 67 market cheeses to support growth of Listeria monocytogenes (LM), Salmonella spp. (SALM), Escherichia coli O157:H7 (EC), and Staphylococcus aureus (SA) over 15 days at 25°C. Hard (Asiago and Cheddar), semi-hard (Colby and Havarti), and soft cheeses (mozzarella and Mexican-style), and reduced-sodium or reduced-fat types were tested. Single-pathogen cocktails were prepared and individually inoculated onto cheese slices (~105 CFU/g). Cocktails were 10 strains of L. monocytogenes, 6 of Salmonella spp., or 5 of E. coli O157:H7 or S. aureus. Inoculated slices were vacuum packaged and stored at 25°C for ≤15 days, with surviving inocula enumerated every 3 days. Percent salt-in-the-moisture phase, percent titratable acidity, pH, water activity, and levels of indigenous/starter bacteria were measured. Pathogens did not grow on 53 cheeses, while 14 cheeses supported growth of SA, 6 of SALM, 4 of LM, and 3 of EC. Of the cheeses supporting pathogen growth, all supported growth of SA, ranging from 0.57 to 3.08 log CFU/g (average 1.70 log CFU/g). Growth of SALM, LM, and EC ranged from 1.01 to 3.02 log CFU/g (average 2.05 log CFU/g), 0.60 to 2.68 log CFU/g (average 1.60 log CFU/g), and 0.41 to 2.90 log CFU/g (average 1.69 log CFU/g), respectively. Pathogen growth varied within cheese types or lots. Pathogen growth was influenced by pH and percent salt-in-the-moisture phase, and these two factors were used to establish growth/no-growth boundary conditions for safe, extended storage (≤25°C) of pasteurized milk cheeses. Pathogen growth/no-growth could not be predicted for Swiss-style cheeses, mold-ripened or bacterial surface–ripened cheeses, and cheeses made with nonbovine milk, as insufficient data were gathered. This challenge study data can support science-based decision making in a regulatory framework.

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