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The search for natural food additives makes propolis an exciting alternative due to its known antimicrobial activity. This work aims to investigate propolis' behavior as a nitrite substitute ingredient in cooked ham (a ready-to-eat product) when confronted with pathogenic microorganisms of food interest. The microbial evolution of Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, and Clostridium sporogenes inoculated at known doses was examined in different batches of cooked ham. The design of a challenge test according to their shelf life (45 days), pH values, and water activity allowed the determination of the mesophilic aerobic flora, psychotropic, and acid lactic bacteria viability. The test was completed with an organoleptic analysis of the samples, considering possible alterations in color and texture. The cooked ham formulation containing propolis instead of nitrites limited the potential growth (δ < 0.5 log10) of all the inoculated microorganisms until day 45, except for L. monocytogenes, which in turn exhibited a bacteriostatic effect between day 7 and 30 of the storage time. The sensory analysis revealed the consumer's acceptance of cooked ham batches including propolis as a natural additive. These findings suggest the functionality of propolis as a promising alternative to artificial preservatives for ensuring food safety and reducing the proliferation risk of foodborne pathogens in ready-to-eat products.
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OBJECTIVE: To estimate, in a cohort of young Portuguese adults, the environmental impact (greenhouse gas (GHG) emissions, land use, energy used, acidification and potential eutrophication) of diet according to adherence to the Mediterranean Diet (MD). METHODS: Data from 1554 participants of the Epidemiologic Health Investigation of Teenagers in Porto (EPITeen) were analysed. Food intake and MD adherence were determined using validated questionnaires. The environmental impact was evaluated with the EAT-Lancet Commission tables, and the link between MD adherence and environmental impact was calculated using adjusted multivariate linear regression models. RESULTS: Higher adherence (high vs. low) to the MD was associated with lower environmental impact in terms of land use (7.8 vs. 8.5 m2, p = 0.002), potential acidification (57.8 vs. 62.4 g SO2-eq, p = 0.001) and eutrophication (21.7 vs. 23.5 g PO4-eq, p < 0.001). Energy use decreased only in the calorie-adjusted model (9689.5 vs. 10,265.9 kJ, p < 0.001), and GHG emissions were reduced only in a complementary model where fish consumption was eliminated (3035.3 vs. 3281.2 g CO2-eq, p < 0.001). Meat products had the greatest environmental impact for all five environmental factors analysed: 35.7% in GHG emissions, 60.9% in energy use, 72.8% in land use, 70% in acidification and 61.8% in eutrophication. CONCLUSIONS: Higher adherence to the MD is associated with lower environmental impact, particularly in terms of acidification, eutrophication, and land use. Reducing meat consumption can contribute to greater environmental sustainability.
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OBJECTIVE: To estimate the environmental impact of a dietary intervention based on an energy-reduced Mediterranean diet (MedDiet) after one year of follow-up. METHODS: Baseline and 1-year follow-up data were used for 5800 participants aged 55-75 years with metabolic syndrome in the PREDIMED-Plus study. Food intake was estimated through a validated semiquantitative food consumption frequency questionnaire, and adherence to the MedDiet was estimated through the Diet Score. Using the EAT-Lancet Commission tables we assessed the influence of dietary intake on environmental impact (through five indicators: greenhouse gas emissions (GHG), land use, energy used, acidification and potential eutrophication). Using multivariable linear regression models, the association between the intervention and changes in each of the environmental factors was assessed. Mediation analyses were carried out to estimate to what extent changes in each of 2 components of the intervention, namely adherence to the MedDiet and caloric reduction, were responsible for the observed reductions in environmental impact. RESULTS: We observed a significant reduction in the intervention group compared to the control group in acidification levels (-13.3 vs. -9.9 g SO2-eq), eutrophication (-5.4 vs. -4.0 g PO4-eq) and land use (-2.7 vs. -1.8 m2). Adherence to the MedDiet partially mediated the association between intervention and reduction of acidification by 15 %, eutrophication by 10 % and land use by 10 %. Caloric reduction partially mediated the association with the same factors by 55 %, 51 % and 38 % respectively. In addition, adherence to the MedDiet fully mediated the association between intervention and reduction in GHG emissions by 56 % and energy use by 53 %. CONCLUSIONS: A nutritional intervention based on consumption of an energy-reduced MedDiet for one year was associated with an improvement in different environmental quality parameters.
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Dieta Mediterránea , Persona de Mediana Edad , Humanos , Anciano , Masculino , Femenino , Ambiente , Gases de Efecto Invernadero/análisis , Eutrofización , Síndrome Metabólico/prevención & controlRESUMEN
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 20 (66.7%) by q-PCR. The concentrations (log10 cfu/g) of L. monocytogenes (q-PCR) ranged from 2.40 to 5.22 (total cells) and from <2.15 to 3.93 (viable cells). The two methods, q-PCR using a viability marker (v-PCR) and OCLA&PCR (gold standard), were compared for their capacity to detect viable cells of L. monocytogenes, with the potential to cause human disease. The values for sensitivity, specificity and efficiency of the v-PCR were 100%, 66.7% and 83.3%, respectively. The agreement between the two methods (kappa coefficient) was 0.67. The presence of nine virulence genes (hlyA, actA, inlB, inlA, inlC, inlJ, prfA, plcA and iap) was studied in 45 L. monocytogenes isolates (three from each positive sample) using PCR. All the strains harbored between six and nine virulence genes. Fifteen isolates (33.3% of the total) did not show the potential to form biofilm on a polystyrene surface, as determined by a crystal violet assay. The remaining strains were classified as weak (23 isolates, 51.1% of the total), moderate (one isolate, 2.2%) or strong (six isolates, 13.3%) biofilm producers. The strains were tested for susceptibility to a panel of 15 antibiotics. An average of 5.11 ± 1.30 resistances per isolate was observed. When the values for resistance and for reduced susceptibility were taken jointly, this figure rose to 6.91 ± 1.59. There was a prevalence of resistance or reduced susceptibility of more than 50.0% for oxacillin, cefoxitin, cefotaxime, cefepime ciprofloxacin, enrofloxacin and nitrofurantoin. For the remaining antibiotics tested, the corresponding values ranged from 0.0% for chloramphenicol to 48.9% for rifampicin. The high prevalence and level of L. monocytogenes with numerous virulence factors in poultry underline how crucial it is to follow correct hygiene procedures during the processing of this foodstuff in order to reduce the risk of human listeriosis.
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The outbreaks of Listeria associated with food consumption are increasing worldwide concurrently with public concern about the need for natural growth inhibitors. In this context, propolis seems to be a promising bioactive product collected by honeybees, due to its antimicrobial activity against different food pathogens. This study aims to evaluate the efficacy of hydroalcoholic propolis extracts for controlling Listeria under several pH conditions. The physicochemical properties (wax, resins, ashes, impurities), the bioactive compounds (phenolic and flavonoid content), and the antimicrobial activity of 31 propolis samples collected from the half North of Spain were determined. Results showed similar trends in the physicochemical composition and bioactive properties, regardless of the harvesting area. Non-limiting pH conditions (7.04, 6.01, 5.01) in 11 Listeria strains (5 from collection and 6 wild strains from meat products) exhibited MICs (Minimum inhibition concentration) and MBCs (Minimum bactericidal concentration) ranging from 39.09 to 625 µg/mL. The antibacterial activity increased under acidic pH conditions, showing a synergistic effect at pH = 5.01 (p < 0.05). These findings suggest the potential of Spanish propolis as a natural antibacterial inhibitor to control Listeria growth in food products.
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The antioxidant, anti-inflammatory, and antimicrobial characteristics of propolis, a bioactive compound collected from hives, have prompted its use in the food sector in recent times. This study investigated the physicochemical characteristics, phenolic profile, and antioxidant capacity of 31 propolis extracts collected from Northern Spain. The physicochemical composition (resins, waxes, ashes mineral content, and heavy metals) was within the allowable regulatory limits. The analysis of bioactive compounds enabled the identification of 51 constituents: flavonoids (apigenin, catechin, chrysin, quercetin, and pinocembrin) and phenolic acids (caffeic, ferulic, and coumaric). The mean value of total polyphenols was 42.72 ± 13.19 Pinocembrin-Galangin Equivalents/100 g, whereas a range between 1.64 ± 0.04 and 4.95 ± 0.36 Quercetin Equivalents (QE) g/100 g was found for total flavonoids content. The determination of bioactivities revealed significant antioxidant capacity using DPPH (1114.28 ± 10.39 µM Trolox Equivalents and 3487.61 ± 318.66 µM Vitamin C Equivalents). Resin content in propolis samples was positively and significantly correlated with both polyphenols (rho = 0.365; p = 0.043) and flavonoid composition (rho = 0.615; p = 0.000) as well as the antioxidant capacity TEAC DPPH (rho = 0.415; p = 0.020). A multiple regression analysis modeled the correlation between resin composition, flavonoids, and TEAC DPPH values, yielding a significant regression equation (R2 = 0.618; F (2,28) = 22.629; p < 0.000; d = 2.299). Therefore, evaluating physicochemical parameters and biological activities provides a promising framework for predicting propolis' quality and antioxidant properties, thus suggesting its potential as a functional and bioactive compound for the food industry.
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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 peracetic acid (PAA), and nine antibiotics in eight strains of Listeria monocytogenes of varying serotypes. Marked intra-species differences were observed in the resistance of L. monocytogenes to the biocides and antibiotics. The MICs (ppm) for the biocides ranged between 1750 and 4500 for SH, 0.25 and 20.00 for BC, and 1050 and 1700 for PAA. Their MBCs (ppm) ranged from 2250 to 4500 for SH, 0.50 to 20.00 for BC, and 1150 to 1800 for PAA. The MICs (ppm) for antibiotics lay between 1 and 15 for ampicillin, 8 and 150 for cephalothin, 20 and 170 for cefoxitin, 0.05 and 0.20 for erythromycin, 4 and 50 for chloramphenicol, 3 and 100 for gentamicin, 2 and 15 for tetracycline, 2 and 80 for vancomycin, and 160 and 430 for fosfomycin. The corresponding MBCs (ppm) were from 5 to 20 for ampicillin, 9 to 160 for cephalothin, 70 to 200 for cefoxitin, 4 to 5 for erythromycin, 9 to 70 for chloramphenicol, 5 to 100 for gentamicin, 3 to 30 for tetracycline, 3 to 90 for vancomycin, and 160 to 450 for fosfomycin. Notably, erythromycin showed considerable efficacy, demonstrated by the low values for both MIC and MBC. Based on EUCAST and the CLSI criteria, all strains were susceptible to erythromycin. All strains were resistant to cephalothin, cefoxitin, gentamicin, and fosfomycin. Further values for resistance were 87.50% for ampicillin and vancomycin, 75.00% for tetracycline, and 62.50% for chloramphenicol. The high prevalence of antibiotic resistance is a matter for concern. A positive correlation was found between MIC and MBC values for most of the biocides and antibiotics. The higher the hydrophobicity of the cell surface, the higher the susceptibility to biocides, suggesting that surface characteristics of bacterial cells influence resistance to these compounds.
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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-species biofilms in which S. enterica and a Gram-positive bacterium existed in combination, were formed on polystyrene and evaluated by using confocal laser scanning microscopy (CLSM). All strains were able to form biofilm. The greatest biovolume in the observation field of 14,161 µm2 was observed for mono-species biofilms after 72 h, where biovolumes of 94,409.0 µm3 ± 2131.0 µm3 (S. enterica), 58,418.3 µm3 ± 5944.9 µm3 (L. monocytogenes), 68,020.8 µm3 ± 5812.3 µm3 (MRSA) and 59,280.0 µm3 ± 4032.9 µm3 (VRE) were obtained. In comparison with single-species biofilms, the biovolume of S. enterica was higher in the presence of MRSA or VRE after 48, 72 and 120 h. In dual-species biofilms, the bacteria showed a double-layer distribution pattern, with S. enterica in the top layer and Gram-positive bacteria in the bottom layer. This spatial disposition should be taken into account when effective strategies to eliminate biofilms are being developed.
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Biopelículas , Enterococcus faecium/química , Listeria monocytogenes/química , Staphylococcus aureus Resistente a Meticilina/química , Salmonella enterica/química , Enterococcus faecium/fisiología , Listeria monocytogenes/fisiología , Staphylococcus aureus Resistente a Meticilina/fisiología , Microscopía Confocal , Salmonella enterica/fisiologíaRESUMEN
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 manufacturing process in the European Union (EU Regulation 2073/2005). Forty Escherichia coli isolates were tested against thirteen clinically important antibiotics (disk diffusion method; CLSI). Three of the strains (7.5%) were susceptible to all the antibiotics, four (10.0%) showed resistance or reduced susceptibility to one antibiotic, and 33 (82.5%) were multiresistant (with resistance or reduced susceptibility to between two and eight antibiotics), with an average of 1.85 resistances per strain. The highest rates of resistance were observed for two antimicrobials widely used on cattle farms (cefalotin and tetracycline). The findings in this research emphasize the need to correctly handle beef preparations with the aim of reducing risks to consumers.
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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 broth method) of 3,800 ppm (SHY), 1,200 ppm (PAA) and 15 ppm (BZK) for CS, and 2,500 ppm (SHY), 1,275 ppm (PAA) and 20 ppm (BZK) for YE, were found. In some instances, an increase in growth rate was observed in presence of sub-MICs (0.25MIC, 0.50MIC or 0.75MIC) of biocides relative to the samples without biocides. The cultures exhibited an acquired tolerance to biocides and an increase in antibiotic resistance after exposure to sub-MICs of such disinfectants. Strains were able to form strong biofilms on polystyrene after 48 hours (confocal laser scanning microscopy), with average biovolumes in the observation field (14,161 µm2) of 242,201.0 ± 86,570.9 µm3 (CS) and 190,184.5 ± 40,860.3 µm3 (YE). Treatment of biofilms for 10 minutes with disinfectants at 1MIC or 2MIC reduced the biovolume of live cells. PAA (YE) and BZK (CS and YE) at 1MIC did not alter the percentage of dead cells relative to non-exposed biofilms, and their effect of countering biofilm was due principally to the detachment of cells. These results suggest that doses of PAA and BZK close to MICs might lead to the dissemination of live bacteria from biofilms with consequent hazards for public health.
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Biopelículas/efectos de los fármacos , Cronobacter sakazakii/fisiología , Desinfectantes/farmacología , Yersinia enterocolitica/fisiología , Antibacterianos/farmacología , Compuestos de Benzalconio/farmacología , Cronobacter sakazakii/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Ácido Peracético/farmacología , Poliestirenos/química , Hipoclorito de Sodio/farmacología , Yersinia enterocolitica/crecimiento & desarrolloRESUMEN
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 from wild and domestic pigeon carcasses were investigated. Average microbial loads (log10 cfu/cm2) ranged from 1.40 ± 1.17 (fecal coliforms) to 3.68 ± 1.40 (psychrotrophs). The highest (p < 0.05) microbial loads were observed in domestic pigeons. No substantial differences were found between isolates from domestic and wild pigeons with regard to the prevalence of antibiotic resistance. Of the E. coli strains, 20.00% were susceptible, 25.00% showed resistance or reduced susceptibility to one antimicrobial and 55.00% were multi-resistant. Among the E. faecalis isolates, 2.22% were susceptible and 97.78% were multi-resistant. The greatest prevalence of resistance or reduced susceptibility among E. coli was observed for amoxicillin-clavulanic acid (20.00% strains), ampicillin (26.67%), streptomycin (55.00%) and tobramycin (20.00%). The prevalence of resistance or reduced susceptibility among E. faecalis ranged from 31.11% (trimethoprim/sulfamethoxazole) to 97.78% (erythromycin). Meat from pigeons is a major reservoir of antibiotic-resistant bacteria. The need for the correct handling of this foodstuff in order to reduce risks to consumers is underlined.
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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 susceptibility of 72 strains to 26 antibiotics of clinical importance was determined by disc diffusion (Clinical and Laboratory Standards Institute; CLSI). High levels of resistance were observed to cefoxitin (77.8% of the strains showed resistance), cefotaxime (62.5%), cefepime (73.6%), and nalidixic acid (97.2%), nitrofurantoin (51.4%) and oxacillin (93.1%). Less than 3% of the strains showed resistance to the antibiotic classes used in human listeriosis therapy (i.e., ampicillin, gentamicin, rifampicin, chloramphenicol, enrofloxacin, vancomycin, trimethoprim-sulfamethoxazole, erythromycin, and tetracycline). The influence of species and serotype on the growth kinetics (modified Gompertz equation) and on the adhesion ability (crystal violet staining) of nine isolates of L. monocytogenes (serotypes 1/2a, 1/2b, 1/2c, 3a, 3b, 3c, 4a, 4b, and 4d), and one strain of Listeria ivanovii were investigated. The maximum growth rate (ΔOD420-580/h) varied between 0.073 ± 0.018 (L. monocytogenes 1/2a) and 0.396 ± 0.026 (L. monocytogenes 4b). The isolates of L. monocytogenes belonging to serotypes 3a and 4a, as well as L. ivanovii, showed a greater (p < 0.05) biofilm-forming ability than did the remaining strains, including those that belong to the serotypes commonly implied in human listeriosis (1/2a, 1/2b, 1/2c and 4b). The need for training in good hygiene practices during the handling of meat and poultry is highlighted to reduce the risk of human listeriosis.
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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 3500â¯ppm (SHY), or between 3â¯ppm and 13â¯ppm (BZK), were found. Minimum bactericidal concentration (MBC) values ranged from 3500â¯ppm to 4500â¯ppm (SHY), and from 3â¯ppm to 14â¯ppm (BZK). The effect of SHY and BZK on the architecture and cellular viability of 24-h-old biofilms formed by such strains on polystyrene was determined through confocal laser scanning microscopy (CLSM) in conjunction with fluorescent dyes for live cells (SYTO 9) and dead cells (propidium iodide). Strains were able to form biofilm (biovolume values in the observation field of 14,161⯵m2 ranged between 103,928.3⯱â¯6730.2⯵m3 and 276,030.9⯱â¯42,291.9⯵m3). Treatment of biofilms for 10â¯min with SHY (1MIC or 1.5MIC) or BZK (0.5MIC, 1MIC or 1.5MIC) decreased the biovolume of live (potentially dangerous) cells. SHY reduced the cellular viability of biofilms by more than 90%. On the other hand, BZK was able to remove most biofilm mass (live and dead cells), but decreased cellular viability only to a lesser extent, this suggesting strong biofilm detachment and dissemination of live cells.
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Compuestos de Benzalconio/farmacología , Biopelículas/efectos de los fármacos , Desinfectantes/farmacología , Listeria monocytogenes/efectos de los fármacos , Hipoclorito de Sodio/farmacología , Biopelículas/crecimiento & desarrollo , Listeria monocytogenes/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Viabilidad Microbiana/efectos de los fármacos , Microscopía ConfocalRESUMEN
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 bacteriophage P100 (Listex P100). The structural parameters of biofilms were studied by using confocal laser scanning microscopy and digital image analysis. The biovolume in the observation field (14,121 µm2) of control (untreated) biofilms was 237,333.1 ± 2,692.6 µm3. The biomass of treated biofilms ranged from 164.7 ± 89.0 µm3 (biofilms exposed to 1010 PFU/mL) to 231,170.5 ± 15,142.0 µm3 (100 PFU/mL). The lowest biomass was achieved after treatment with 108 PFU/mL, with no further decrease in biovolume when higher phage concentrations were used. A strong ( P < 0.001) correlation was found between phage concentration (log units) and biovolume (-0.965), surface coverage (-0.939), roughness (0.976), maximum thickness (-0.853), and average thickness (-0.965). Findings from this research suggest that bacteriophage P100 at concentrations equal to or greater than 8 log PFU/mL successfully removes L. monocytogenes biofilms from polystyrene surfaces.
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Bacteriófagos , Biopelículas/crecimiento & desarrollo , Listeria monocytogenes , Recuento de Colonia Microbiana , Inocuidad de los Alimentos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/fisiología , Listeria monocytogenes/virologíaRESUMEN
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 24â¯h and 72â¯h of incubation at 37⯰C were examined by confocal laser scanning microscopy (CLSM) after staining with SYTO9 and propidium iodide (PI). A lower average biovolume (Pâ¯<â¯0.05) was observed for SH174 biofilms (73,073.61⯱â¯52,365.90⯵m3 in the observation field of 14,161⯵m2) than for LM6 (180,804.50⯱â¯32,554.62⯵m3), MRSA125 (208,605.34⯱â¯57,534.93⯵m3) and VRE61s (212,543.91⯱â¯39,718.62⯵m3) biofilms. SH174 showed the greatest (P < 0.05) biovolume on glass, as compared with polystyrene. Biofilms of LM6, MRSA125 and VRE61s were produced at comparable levels on both contact surfaces. After 24â¯h, SH174 formed small scattered cell clusters, and biovolume of biofilms increased (Pâ¯<â¯0.05) after 72â¯h. By contrast, LM6, MRSA125 and VRE61s formed compact biofilms quickly (24â¯h) on both contact surfaces. Seventy-two-hour-old biofilms showed the largest biovolumes of dead or damaged (PI-stained) cells, except for MRSA125 (polystyrene) and VRE61s (polystyrene and glass). Appropriate procedures for the disinfection of food processing surfaces immediately after use are required to prevent the formation of biofilm by pathogenic bacteria.
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Biopelículas , Enterococcus faecalis/crecimiento & desarrollo , Manipulación de Alimentos/instrumentación , Listeria monocytogenes/crecimiento & desarrollo , Staphylococcus aureus Resistente a Meticilina/crecimiento & desarrollo , Adhesión Bacteriana , Recuento de Colonia Microbiana , Enterococcus faecalis/fisiología , Contaminación de Equipos , Vidrio/química , Listeria monocytogenes/fisiología , Staphylococcus aureus Resistente a Meticilina/fisiología , Poliestirenos/químicaRESUMEN
AIM: To determine the impact of the type of hospital kitchen on the dietary intake of patients. METHODS: A cross-sectional, two-centre study, of cooking in a traditional kitchen (TK) and in a chilled kitchen (CK). Subjective global assessment (SGA) was used for nutritional diagnosis. Before study start, a dietician performed a nutritional assessment of the menus of each hospital. All dishes were weighed upon arrival to the ward and at the end of the meal. RESULTS: 201 and 41 patients from the centres with TK and CK respectively were evaluated. Prevalence of malnutrition risk was 50.2% at the hospital with TK and 48.8% at the hospital with CK (p=0.328). Forty-eight and 56 dishes were nutritionally evaluated at the hospitals with TK and CK respectively. Intake analysis consisted of 1993 and 846 evaluations in the hospitals with TK and CK respectively. Median food consumption was 76.83% at the hospital with TK (IQR 45.76%) and 83.43% (IQR 40.49%) at the hospital with CK (p<0.001). Based on the prevalence of malnutrition, a higher protein and energy intake was seen in malnourished patients from the CK as compared to the TK hospital, but differences were not significant after adjustment for other factors. CONCLUSIONS: Cooking in a chilled kitchen, as compared to a traditional kitchen, may increase energy and protein intake in hospitalized patients, which is particularly beneficial for malnourished patients.
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Ingestión de Alimentos , Manipulación de Alimentos/métodos , Servicio de Alimentación en Hospital/organización & administración , Desnutrición/psicología , Anciano , Apetito , Índice de Masa Corporal , Estudios Transversales , Grupos Diagnósticos Relacionados , Proteínas en la Dieta , Ingestión de Energía , Femenino , Hospitales Universitarios , Humanos , Masculino , Desnutrición/epidemiología , Desnutrición/prevención & control , Evaluación Nutricional , Refrigeración , TemperaturaRESUMEN
We evaluated the effects of glucomannan or glucomannan plus spirulina-restructured pork (RP) on liver fatty acid profile, desaturase/elongase enzyme activities and oxidative status of Zucker fa/fa rats for seven weeks. Control (C), glucomannan (G) and glucomannan/spirulina (GS)-RP; HC (cholesterol-enriched control), HG and HGS (cholesterol-enriched glucomannan and glucomannan/spirulina-RP) experimental diets were tested. Increased metabolic syndrome markers were found in C, G and GS rats. Cholesterol feeding increased liver size, fat, and cholesterol and reduced antioxidant enzyme levels and expressions. Cholesterolemia was lower in HG and HGS than in HC. GS vs. G showed higher stearic but lower oleic levels. SFA and PUFA decreased while MUFA increased by cholesterol feeding. The arachidonic/linoleic and docosahexaenoic/alpha-linolenic ratios were lower in HC, HG, and HGS vs. C, G, and GS, respectively, suggesting a delta-6-elongase-desaturase system inhibition. Moreover, cholesterol feeding, mainly in HGS, decreased low-density-lipoprotein receptor expression and the delta-5-desaturase activity and increased the delta-9-desaturase activity. In conclusion, the liver production of highly unsaturated fatty acids was limited to decrease their oxidation in presence of hypercholesterolaemia. Glucomannan or glucomannan/spirulina-RP has added new attributes to their functional properties in meat, partially arresting the negative effects induced by high-fat-high-cholesterol feeding on the liver fatty acid and antioxidant statuses.
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The objective of this research was to determine the behavior of Listeria monocytogenes in three types of sliced ready-to-eat meat products packaged under vacuum or modified atmosphere conditions and stored at three temperatures. Slices of about 25 g of chorizo (a fermented dry pork sausage), jamón (cured ham), and cecina (a salted, dried beef product) were inoculated with L. monocytogenes NCTC 11994. Slices were packaged in a vacuum or in a modified atmosphere (20% CO2, 80% N2). After packaging, samples were stored for 6 months at three temperatures: 3, 11, or 20°C. Microbiological analyses were performed after 0, 1, 7, 15, 30, 45, 90, and 180 days of storage. The type of meat product, the type of packaging, the temperature, and the day of storage all influenced microbial levels (P < 0.001). L. monocytogenes counts decreased throughout the course of storage in samples of chorizo (quick decrease) and jamón (gradual decrease). In cecina samples, counts of L. monocytogenes increased from day 0 to day 1 of storage and then remained constant until day 90 of the study. These results may be of use for enhancing the safety of these ready-to-eat meat product types. Additional evaluation of the behavior of L. monocytogenes in cecina is needed.
Asunto(s)
Embalaje de Alimentos/métodos , Listeria monocytogenes/crecimiento & desarrollo , Productos de la Carne/microbiología , Animales , Recuento de Colonia Microbiana , Fermentación , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Humanos , Concentración de Iones de Hidrógeno , Listeria monocytogenes/aislamiento & purificación , Nitratos/análisis , Cloruro de Sodio/análisis , Porcinos , Temperatura , VacioRESUMEN
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 testing (15 antimicrobials; disk diffusion method). Salmonella was detected in 40 (55%) samples in 1993 and 19 (12.4%) in 2006 (P<0.001). The serotypes (S. Enteritidis, Salmonella Poona, Salmonella Infantis, Salmonella Newport and S. Typhimurium) and phage types (1, 4, 14b and 35 in the case of S. Enteritidis and 193 for S. Typhimurium) detected are among the main types responsible for human salmonellosis in Spain. All strains were multi-resistant (resistant to 3-13 antimicrobials). The average number of resistances per strain increased (P<0.05) from 3.98 in 1993 to 5.00 in 2006. An increase in the incidence of resistance was observed between 1993 and 2006 for cephalothin (P<0.01), enrofloxacin (P<0.001) and tetracycline (P<0.01). The decreases in the prevalence of Salmonella between 1993 and 2006 suggest that the mandatory measures introduced over the last decade in the European Union to reduce the incidence of Salmonella in poultry have apparently been successful. However, the increase in antibiotic resistance rates is of concern and constitutes a threat to public health. Because the data in this study demonstrated that chicken in North-Western Spain is a potential source of antibiotic-resistant Salmonella strains, the need of consumer education on good sanitary practices is highlighted.
Asunto(s)
Farmacorresistencia Bacteriana Múltiple , Contaminación de Alimentos , Carne/microbiología , Salmonella enterica/aislamiento & purificación , Salmonella enteritidis/aislamiento & purificación , Animales , Antibacterianos/farmacología , Tipificación de Bacteriófagos , Pollos , Farmacorresistencia Bacteriana/efectos de los fármacos , Unión Europea , Microbiología de Alimentos , Humanos , Enfermedades de las Aves de Corral , Prevalencia , Salud Pública , Salmonella/clasificación , Salmonella/efectos de los fármacos , Salmonella/aislamiento & purificación , Intoxicación Alimentaria por Salmonella/prevención & control , Salmonelosis Animal , Salmonella enterica/clasificación , Salmonella enterica/efectos de los fármacos , Salmonella enteritidis/clasificación , Salmonella enteritidis/efectos de los fármacos , Serotipificación , EspañaRESUMEN
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 Staphylococcus aureus, respectively. Chicken parts were generally regarded as being of unacceptable quality, since psychrotrophs, E. coli and S. aureus counts were higher than the maximum limits established in the guidelines for poultry meat. On the basis of Spanish Microbiological Standards, 80% of the samples of hamburgers and sausages were also regarded as being of unacceptable quality. The main reason for the lack of acceptability was excessive counts of mesophiles. The results in this study indicate that chicken by-products (especially those made with ground meat) could represent notable hazards to humans and are a cause of public health concern.