Paul Anthony Gibbs

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Staphylococcus aureus represents a public health challenge worldwide. The aim of this study was the characterization of different food isolates of S. aureus on the basis of their production of enterotoxins, hemolysins and resistance to antibiotics. A total of 148 coagulase-positive staphylococcal strains isolated from different food origins were identified(More)
Campylobacter is well recognized as the leading cause of bacterial foodborne diarrheal disease worldwide. Symptoms can range from mild to serious infections of the children and the elderly and permanent neurological symptoms. The organism is a cytochrome oxidase positive, microaerophilic, curved Gram-negative rod exhibiting corkscrew motility and is carried(More)
The aim of this research effort was to investigate the role of various sugar substrates in the growth medium upon thermotolerance and upon survival during storage after freeze-drying of Lactobacillus bulgaricus. Addition of the sugars tested to the growth medium, and of these and sorbitol to the drying medium (skim milk) was investigated so as to determine(More)
AIMS Poultry meat is considered a major source of Campylobacter. This micro-aerobic bacterium is commonly responsible for foodborne illness. This work focuses on the isolation of Campylobacter coli lytic bacteriophages (phages) against target C. coli strains. METHODS AND RESULTS A method involving the enrichment of free-range chicken samples in a broth(More)
This work had as main objectives to characterize two bacteriocins produced by lactic acid bacteria (LAB) previously isolated from non-fermented seafood, in order to evaluate their potential as new food protective agents. The two bacteriocinogenic isolates were identified by Polymerase Chain Reaction (PCR) using genus- and species-specific primers, and(More)
Microbiological characterization of alheiras, traditional smoked meat sausages produced in northern Portugal, had previously shown that more than 60% of the lots analyzed were contaminated with Listeria monocytogenes at levels higher than 100 CFU/g. In order to better understand L. monocytogenes contamination patterns in alheiras, we characterized 128 L.(More)
No significant differences were observed in the viability of Lactobacillus plantarum and Lactobacillus rhamnosus cells during freeze-drying in the presence or absence of inositol, sorbitol, fructose, trehalose, monosodium glutamate and propyl gallate. However, survival was higher during storage when drying took place in the presence of these compounds.(More)
Spray-dried cells of Lactobacillus sakei CTC 494 survived ca. 60% longer in the spray dried state when cells were grown in the presence of 20 g sucrose l−1or 12.5 g monosodium glutamate l−1. No significant differences were observed in viability during storage in the freeze dried state with the addition of these compounds to the growth medium, nor in(More)
Alheiras are traditional smoked naturally fermented meat sausages produced in the north of Portugal. They have not previously been characterized as to their chemical and microbiological status. pH and salt levels are insufficient to assure microbiological safety, there is ample opportunity for post-cooking contamination; the products require chill storage(More)
Several types of food products on sale in Portugal, were examined for the presence of Listeria monocytogenes. Secondary enrichments, in Fraser broth, were analysed by the mini-Vidas LMO, enzyme-linked fluorescent immunoassay technique. Positive samples were confirmed by isolation on Oxford and PALCAM selective agars followed by biochemical characterization.(More)