Camino Garcia Fernandez

University of Leon | UNILEON · Department of Hygiene and Food Technology

The prevalence of Listeria monocytogenes in 30 samples of poultry was determined using culture-dependent (isolation on OCLA and confirmation by conventional polymerase chain reaction -PCR-, OCLA&PCR) and culture-independent (real-time polymerase chain reaction, q-PCR) methods. L. monocytogenes was detected in 15 samples (50.0%) by OCLA&PCR and in 2...

When selecting effective doses of antimicrobials, be they biocides or antibiotics, it is essential to know the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these substances. The present research determined the MICs and MBCs for three biocides, sodium hypochlorite (SH), benzalkonium chloride (BC), and pe...

The objective of this study was to characterize the biofilms formed by Salmonella enterica serotype Agona, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium (VRE) after 12, 48, 72, 120 and 240 h of incubation at 10 °C. Biofilms containing a single species, together with dual-spe...

Beef preparations (meatballs, minced meat, hamburgers, white sausages, and red sausages) from northwest Spain were tested. Microbial counts ranged from 0.70 ± 0.00 log10 cfu/g (enterococci) to 9.57 ± 0.37 log10 cfu/g (psychrotrophs). In 73.3% of cases, total aerobic counts were higher than the microbiological limits set for the end of the manufactu...

The susceptibility of Cronobacter sakazakii ATCC 29544 (CS) and Yersinia enterocolitica ATCC 9610 (YE) to sodium hypochlorite (10% of active chlorine; SHY), peracetic acid (39% solution of peracetic acid in acetic acid; PAA) and benzalkonium chloride (BZK) was tested. Minimum inhibitory concentration (MIC) values (planktonic cells; microdilution br...

Using agglutination techniques, 118 Listeria monocytogenes isolates from red meat and poultry were serotyped. Strains were ascribed to the serotypes 4b/4e (44.1% of the strains), 1/2 (a, b or c; 28.0%), 4c (6.8%), 4d/4e (5.9%) and 3 (a, b or c; 2.5%). Among these are the serotypes most frequently involved in cases of human listeriosis. The suscepti...

An expansion in the consumption of pigeon meat has occurred in recent years. However, little is known about microbial load and antibiotic resistance of this foodstuff. The hygiene status and the antibiotic resistance patterns (disc diffusion; Clinical and Laboratory Standards Institute, CLSI) of Escherichia coli and Enterococcus faecalis isolates f...

The susceptibility of four L. monocytogenes isolates from pork to sodium hypochlorite (SHY) and benzalkonium chloride (BZK) was tested. Minimum inhibitory concentration (MIC) values of 3500 ppm (SHY), or between 3 ppm and 13 ppm (BZK), were found. Minimum bactericidal concentration (MBC) values ranged from 3500 ppm to 4500 ppm (SHY), and from 3 ppm...

Because listeriosis is one of the deadliest foodborne diseases, controlling and eradicating Listeria monocytogenes biofilms is a serious challenge for food safety. Biofilms (24 h old) formed on polystyrene by a L. monocytogenes strain of food origin were exposed for a further 24 h to 12 different concentrations (from 100 to 1011 PFU/mL) of the bact...

The biofilms formed by Salmonella Hadar (SH174), Listeria monocytogenes (LM6), methicillin-resistant Staphylococcus aureus (MRSA125) and vancomycin-resistant Enterococcus faecium (VRE61s) on polystyrene and glass after 24 h and 72 h of incubation at 37 °C were examined by confocal laser scanning microscopy (CLSM) after staining with SYTO9 and propi...

The aim of this study was to determine and compare the antibiotic resistance profiles of Listeria monocytogenes isolates obtained from poultry in North-Western Spain in 1993 and 2006. The prevalence of Listeria spp. and L. monocytogenes was also investigated. A total of 202 samples were analysed (100 in 1993 and 102 in 2006). Samples taken in 1993...

A total of 226 chicken samples (carcasses, legs, wings, necks and breasts) were obtained (73 in 1993 and 153 in 2006) from 10 retail outlets in North-Western Spain and screened for the presence of Salmonella. Isolates were subjected to serotyping, phage typing (Salmonella Enteritidis and Salmonella Typhimurium) and antimicrobial susceptibility test...

The effectiveness of five commercial disinfectants used in the food industry was evaluated against different strains isolated from foodborne outbreaks (E. coli O157:H7, Salmonella spp. and L. monocytogenes) and a collection strain (S. aureus) in an aqueous suspension medium. The disinfectants evaluated included quaternary ammonium compounds, aldehy...

Sous vide technology, which implies vacuum packaging, pasteurization and storage at a chill temperature, also implies a challenge to obtain a balance between an extended shelf life and microbiological safety of the product with a fresh-like appearance and a high nutritional value. The aim of this work was to determine the effect of fat content of t...

Aging is associated with increased risk of developing anaemia and micronutrient deficiencies. The purpose of this study was to evaluate the daily intake of micronutrient whose deficient in diet could cause anaemia (iron, folic acid, vitamin B12) and vitamin C to establish the prevalence of anaemia in a group of institutionalized of 124 elderly subj...

This study examined the incidence of Salmonella in Spanish poultry products. Samples included chicken carcasses, chicken parts (wings, legs and giblets-livers and hearts) and processed chicken products (red sausages, white sausages and hamburgers). The average detection rate was 49%, with the highest (55%) in chicken carcasses (skin) and the lowest...

Monitoring of energy distribution of the three macronutrients of diet could be beneficial in order to improve the physiological status of elderly people. The objective of this study is to analyse total daily energy intake as well as the caloric contribution of the macronutrients and alcohol, which make up basic diet of five nursing homes in León (S...

Monitoring of energy distribution of the three macronutrients of diet could be beneficial in order to improve the physiological status of elderly people. The objective of this study is to analyse total daily energy intake as well as the caloric contribution of the macronutrients and alcohol, which make up basic diet of five nursing homes in León (S...

The influence of sample type (i.e., excised versus nonexcised chicken skin) on the efficiency of trisodium phosphate (TSP) solutions in reducing Listeria monocytogenes populations and inhibiting their growth during refrigerated storage was studied. Whole chicken legs and excised chicken leg skin fragments inoculated with 10(8) CFU of L. monocytogen...

The population of the elderly people is increasing in our society, and it is very frequently affected by undernutrition problems. It is mainly due to an inadequate intake of micronutrients, as well as to a higher incidence of chronic diseases, which negatively affect the nutritional status. The aim of this study is to assess the levels, in terms of...

The microbiological quality of retail chicken parts (legs, wings and giblets) and processed chicken products (hamburgers and sausages) in Spain was investigated. Mean counts (log(10) cfu/g) ranged from 5.56 to 7.28, 5.96 to 7.87, 3.49 to 5.42, 2.60 to 4.33 and 2.47 to 3.48 for mesophiles, psychrotrophs, coliforms, Escherichia coli and Staphylococcu...

The aim of this study was to determine the influence of skin sample site on the efficacy of trisodium phosphate (TSP) solutions in reducing Listeria monocytogenes populations on chicken carcasses during refrigerated storage. Chicken skin samples from the legs, the breasts, and the dorsal area inoculated with L. monocytogenes (10(8) CFU/ml) were dip...

Ninety-six Staphylococcus aureus isolates from retail chicken carcasses in Spain were characterized using cultural and biochemical tests. The strains were phage typed with the international bacteriophage set for typing S. aureus of human origin. Eighty-eight (91.7%) strains were of the poultry ecovar. Strains of human ecovar were not found. These f...

The validity of the international phage set and 13 experimental phages for subtyping Listeria monocytogenes strains isolated from poultry in Spain was investigated. Ninety-six L. monocytogenes strains (52 from serogroup 1/2 and 44 from serogroup 4) were phage-typed using the international phage set, 10 experimental phages for typing serogroup 1/2 s...

Use of trisodium phosphate (TSP) treatment for reducing levels of bacteria in poultry is discussed with reference to: health and economic consequences of poultry contamination, causes or routes of contamination, possibilities for reduction of microbial loads, mechanisms of action of TSP, sensory properties and quality of TSP-treated poultry, antimi...

A total of 40 eviscerated and refrigerated chicken carcasses were collected from five retail outlets (three supermarkets and two poulterers' shops) in León (Spain). The level of microorganisms on chicken carcasses was assessed using the excised breast-skin technique. Mean counts (log10 CFU/g) of psychrotrophs, pseudomonads, fluorescent pseudomonads...

Chicken skin inoculated with l0(8) CFU/ml of Listeria monocytogenes was dipped for 15 min in sterile water (control) and in 8, 10, or 12% trisodium phosphate (TSP) solutions. Skin samples were stored at 2 degrees C for 5 days, with microbial monitoring on days 0, 1, 3, and 5 after treatment. Compared to the water dip, all TSP treatments significant...

All combinations of two secondary selective enrichment broths, UVM II (University of Vermont II) and Fraser, and two selective plating media, PALCAM (polymixin B, acriflavin, lithium chloride, ceftazidime, aesculin, D-mannitol) and MOX (modified Oxford) were compared for isolating Listeria spp. from retail raw chicken meat. Percentages of samples w...

Hemolytic activity is a fundamental criterion for the differentiation of Listeria species; therefore, a simple and inexpensive procedure to clearly distinguish hemolytic strains from each other and from nonhemolytic strains would be of great aid. We compared the efficacy of several techniques, culture media, and types of blood in demonstrating the...

The present study was conducted to determine the influence of strain and trisodium phosphate (TSP) concentration in the growth of Listeria monocytogenes in vitro. Three strains (ATCC 11916, 64d, isolated from chicken meat, and M2-5b, a clinical animal isolate) were inoculated in broth with 0, 0.5, 1 and 1.5% (w/v) of TSP. The shortest lag phase and...

The prevalence of Listeria spp. on the skin of a hundred fresh chicken carcasses purchased from 20 retail stores in León was investigated using the routine test procedure recommended by the United States Department of Agriculture (USDA). PALCAM and Modified Oxford agar (MOX) were used for isolation. Listeria spp., Listeria monocytogenes, L. innocua...

The potential for using trisodium phosphate (TSP) to reduce mesophilic and psychrotrophic popula tions on the skin of chicken carcasses was explored. Skin samples were immersed in sterile tap water (control) or an 8%, 10% or 12% solution of TSP at 20 °C for 15 min. Surface pH values and mesophilic and psychrotrophic plate counts were determined aft...

The effect of trisodium phosphate (TSP) solutions treatments on the sensory evaluation of poultry meat has been explored since TSP was recently approved by USDA for its usage in poultry processing to eliminate Salmonella contamination. In the present study, fresh chicken thighs were dipped in water (control sample) and in 8, 10 and 12% TSP solution...

The effects of formulation, starter culture and fermentation temperature on growth and synthesis of toxin A (SEA) and TNase by Staphylococcus aureus during fermentation and drying of Spanish chorizo were investigated. Inhibitory factors able to inhibit SEA synthesis in culture media were unable to prevent SEA production in chorizo fermented at 20 a...

The change of bacterial counts during hanging at 8 °C of three groups of red partridges (Alectoris rufa) (wild, farmed and "mixed") was determined by sampling at 12 h, 4 and 8 d post mortem and at the spoilage time. Although mesophiles and Enterobacteriaceae multiplied rapidly on the skin and in the small intestine, respectively, of wild birds, the...

The incidence of psychrotrophic bacteria was investigated in a Spanish fresh ewes' cheese (Villalón). Counts of mesophiles and psychrotrophs were (log cfu/g) 5.72 +/- 1.10 and 3.90 +/- 1.01, respectively, for factory cheeses made from pasteurized-milk. Figures for hand-made cheeses made from raw-milk were 7.35 +/- 0.48 and 6.94 +/- 0.65, respective...

Presumptive aeromonads were detected in 8 batches of Villalón cheese produced in dairy plants from pasteurized ewe's milk, the mean count being 2.85 ± 0.24 log CFU/g. Only four isolates from 2 batches were confirmed as motile aeromonads and they fitted the description of Aeromonas hydrophila. During cheese making of 5 batches of farmhouse-made raw...

Samples of cheeses naturally contaminated with moulds (12 samples of mouldy Manchego cheese and 10 of a naturally ripened blue cheese) were analysed for the presence of mycotoxins (aflatoxins BI and MI, sterigmatocystin, patulin, penicillic acid and mycophenolic acid in Manchego cheese, and mycophenolic acid and roquefortine in blue cheese). In add...

A total of 204 psychrotrophic isolates from raw ewes' milk (hand and machine milked) were identified by conventional methods. In addition, a numerical taxonomic study was conducted on 180 of these isolates and 19 reference strains. Three of the isolates were yeasts. Using identification schemes, 54 isolates were assigned to genera of Gram-negative...

This review deals with several aspects of Aeromonas hydrophila and other motile Aeromonas species associated with foodborne illness. Although it is mainly dedicated to the factors affecting growth and survival of this species in foods of animal origin, information on other topics is also provided. This paper includes sections on: Taxonomy, diseases...