0000000000226191
AUTHOR
H. Rico
Incidence of enterotoxigenic staphylococci and their toxins in foods
Of 504 food samples collected from cafeterias, 19 (3.8%) yielded strains of enterotoxigenic staphylococci, and 10 (52.6%), 4 (21.1%), 3 (15.8%), and 2 (10.5%) of these strains produced enterotoxins C (SEC), D (SED), B (SEB), and A (SEA), respectively. Moreover, SEA, SEB, and SEC were isolated from three hamburger samples. Of 181 food samples collected from four restaurants before the implementation of the hazard analysis and critical control point (HACCP) system, 7 (3.9%) were found to contain enterotoxigenic strains, and SED, SEC, and SEA were produced by 4 (57.1%), 2 (28.6%), and 1 (14.3%) of these strains, respectively. One meatball sample with SEC was detected in a restaurant. After the…
Incidence of microbial flora in lettuce, meat and Spanish potato omelette from restaurants
A total of 370 samples including lettuce, meats (beef, pork and chicken) and Spanish potato omelette from restaurants were studied to evaluate the incidence of Escherichia coli, E. coli O157:H7,Staphylococcus aureus, Salmonella spp.,Yersinia enterocolitica, enterococci and some micro-organisms that can cause spoilage orcan be usedas indicators for food safety. Escherichia coliand enterococci were harboured with the highest incidence in lettuce, whereas incidence of Staphylococcus aureus was higherin meat than in the other foods studied. Enterobacter cloacae and Klebsiella pneumoniaewere isolated from the three food groups. Chryseomonas luteola, Enterobacter sakazakii, Klebsiella ozaenae, Mo…
Assessment of the microbiological quality and wash treatments of lettuce served in University restaurants
Abstract One hundred and forty-four samples of lettuce from 16 University restaurants were analyzed. The mesophilic aerobic counts of all samples ranged from 3.01 to 7.81 log 10 CFU g −1 . Results of total coliforms ranged from 3.38 log 10 most probable number (MPN) g −1 . Of the lettuce samples, 25.7% harbored Escherichia coli , 22.9% Staphylococcus aureus and 84% group D streptococci. Similarly, 10.4% of the samples harbored Aeromonas hydrophila , 2.8% Pseudomonas aeruginosa , and coliforms such as 14.6% Citrobacter freundii , 8.3% Klebsiella pneumoniae , 4.2% Enterobacter cloacae and 1.4% Providencia spp. Salmonella , Shigella and E. coli O157:H7 were not detected. When sodium hypochlori…
Microbial evaluation of Spanish potato omelette and cooked meat samples in University restaurants.
The focus of this study was to evaluate the microbial quality of Spanish potato omelette and cooked meat samples including pork loin, chicken croquettes, long pork sausage, chicken breast, and meatballs from University restaurants. Microbiological analyses of Spanish potato omelette and cooked meat samples resulted in aerobic plate counts from1.00 to 2.90 and from1.00 to 6.04 log10 CFU g(-1), respectively. Total coliforms ranged from3 to 43 most probable number (MPN) g(-1) and from3 to2,400 MPN g(-1) for Spanish potato omelette and meat products, respectively. Escherichia coli, coagulase-positive staphylococci, and Lancefield group-D streptococci were detected in 1.7%, 3.5%, and 12.9% of Sp…
Listeria species in raw and ready-to-eat foods from restaurants.
From September 1999 to March 2000, meat (pork, beef, and chicken), fish (salmon, hake, and sole), vegetable (lettuce and spinach), and Spanish potato omelette samples obtained at restaurants were collected and tested for the occurrence of Listeria spp. Listeria monocytogenes was isolated from 3 (2.9%) out of 103 studied samples. Other species isolated were Listeria grayi (13.6%), Listeria innocua (1.9%), Listeria ivanovii (5.8%), Listeria seeligeri (3.9%), and Listeria welshimeri (1.9%). Listeria was neither isolated from beef nor any type of fish.
Incidence of Staphylococcus aureus in meals from cafeterias
A study to determine the incidence of Staphylococccus aureus in 705 meals from several cafeterias in Valencia, Spain was undertaken. Out of the 705 studied meals, 81 samples (I I. I %) had coagulase positive staphylococci with a range of S. aureus from 100 to 53000 cfu/g. me four highest values (> l0,ooO S. aureus &/g) were obtained with Russian type salad, meatballs, chicken croquettes and salad. These products involved more handling stages. These data show that food handlers may contribute to food poisoning and that there are some handling practices that require more attention.
Characterization of aSchizosaccharomyces pombemorphological mutant altered in the galactomannan content
In a search for Schizosaccharomyces pombe mutants resistant to the antifungal agent papulacandin B, a morphological mutant was isolated. The mutant is round shaped in contrast to the rod shaped parental strain. This morphological defect segregated as a recessive Mendelian character and was not observed in other papulacandin B resistant mutants belonging to the same complementation group. The mutation mapped in the right arm of S. pombe chromosome III very close to pap1 marker. Mutant cell walls were more susceptible to alkali extraction and Novozyme degradation than those from the wild-type. A specific reduction in the cell wall galactomannan fraction was the only significant difference det…
Effect of introduction of HACCP on the microbiological quality of some restaurant meals
The microbial quality of Spanish potato omelette and pork loin before and after implementation of the HACCP system in University restaurants was used as indicator of food safety in this work. The prevalence of aerobic plate counts and incidences of Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Listeria monocytogenes, Salmonella spp. and Clostridium perfringens were analysed. Results of implementation of the HACCP system show a lower incidence of studied microorganisms. On the other hand, a documented training in personal hygiene, good manufacturing practices (GMPs), cleaning and sanitation procedures and personal safety in addition to the rearrangement in the infrastructure of t…