Search Results (1,078)

Postbiotics are emerging as potential functional ingredients for companion animal diets. This study aimed to determine if a Saccharomyces cerevisiae-based postbiotic can alter cytokine and stress responses to exercise and transport stress in adult Labrador Retrievers. Dogs received 15 g ground corn germ (Control, n = 12), 7.5 g postbiotic (Low, n = 12), or 15 g postbiotic (High, n = 12), daily for 63 days. Exercise was twice weekly for 7 weeks, and a single transport per dog occurred in week 8. Fecal inflammatory biomarkers, serum chemistries, and complete blood counts were assessed at the beginning and end of the study. Serum cytokines were quantified before and 18–20 h after the first and last exercise runs. Gait analysis was assessed before and 24 h after the first and final runs. Saliva cortisol was measured before and after transportation. Treatment did not affect blood chemistries, gait, fecal biomarkers, or saliva cortisol (p ≥ 0.19). Eosinophils increased slightly in Controls (p = 0.01), though remained below 0.80 × 10⁹ cells/L. Most cytokines were unaffected by treatment (p ≥ 0.15), but there were minor changes in circulating monocyte chemoattractant protein-1 (p = 0.01) and IL-8 over time at the initial run (p = 0.03) and IL-10 in males (p = 0.02) in the Low dose dogs. The High dose decreased Blautia (p = 0.04) slightly and tended to decrease Fusobacterium abundances (p = 0.07). The Low dose tended to increase Clostridium hiranonis (p = 0.07) slightly. The tested S. cerevisiae postbiotic produced small changes in immune function and gut microbial species in dogs. Full article

This study investigated the microbiological and parasitic quality of sewage sludge treated in drying beds in Algeria, aiming to contribute to a better understanding of the factors influencing sludge safety for potential agricultural applications in the Algerian context. The research focused on various sludge types (liquid, semi-solid, and solid) and their behavior across different seasons. Standard microbiological methods were employed to quantify total coliforms, fecal streptococci, E. coli, and Clostridium. Controls were implemented to ensure accuracy, with positive controls validating detection methods using known quantities of microorganisms and parasites, while negative controls confirmed the absence of contamination in the testing environment. Parasitic contamination was assessed through microscopic examination for protozoa and helminths. Results revealed substantial variation in microbial concentrations across sludge types and seasons. Liquid sludge, particularly during summer, exhibited the highest levels of total coliforms (up to 7.021 log10) and E. coli (up to 6.049 log10), while solid sludge showed lower counts. Seasonal trends indicated increased microbial levels during warmer months. Parasitic contamination was prevalent in 81% of samples, with protozoan cysts (e.g., Giardia intestinalis and Endolimax nanus) and helminth eggs detected. Despite reducing microbial loads, drying processes alone were insufficient, leaving significant contamination. Enhanced protocols are needed, such as longer drying periods, chemical disinfectants, or advanced technologies like anaerobic digestion or composting. This highlights the need for locally adapted treatment strategies. Furthermore, this research provides specific recommendations for improving sewage sludge management practices in Algeria, taking into account the unique environmental and agricultural context of the country. Full article

This study aimed to explore the microbial communities present in aquifer groundwater at a petrochemical refinery and their relationship with groundwater quality parameters, with a focus on common contaminants such as benzene, toluene, ethylbenzene, and dichloroethane (DCA). Groundwater samples were collected from both the source and plume regions to analyze the spatial diversity of the microbial communities utilizing 16S rRNA analysis. The study demonstrated substantial variations in microbial diversity and composition across the sampled sites. The data showed that the operational taxonomic unit count, Shannon index, and Simpson index initially rose before declining with escalating contaminant concentration, suggesting that the level of contaminants significantly influences the abundance and diversity of microbial communities in the phreatic groundwater. Moreover, through SPSS analysis, the study quantitatively established the correlation between the physiochemical characteristics of the groundwater and the microbial community structure. The study disclosed that geochemical parameters, including total alkalinity, ferrous content, and DCA, play a role in shaping the abundance and diversity of microbial communities at the phylum, class, and genus levels. This research contributes to our comprehension of the intricate interplay between microbial communities, particularly those implicated in the biotransformation of benzene and DCA, and their surrounding physiochemical milieu within contaminated zones. Full article

Background/Objectives: Waste milk harbors many bacteria and antibiotic residues. Calves fed with untreated waste milk have a higher incidence of scours and an increased risk of developing antimicrobial-resistant bacteria. This study aimed to evaluate the efficacy of treatment with copper ions on bacteria and antibiotics contained in bovine waste milk. Methods: Waste milk samples were collected from a dairy farm for seven weeks and were subjected to treatment with copper ions. Total bacterial counts, coliforms, Streptococcus, and Staphylococcus were assessed before and after treatment. Additionally, metagenomic analysis was performed to determine microbial diversity. Results: Before treatment, the total bacterial count average was 4.0 × 10⁶ CFU/mL, 1.7 × 10⁴ CFU/mL for coliforms, 2.6 × 10⁶ CFU/mL for Streptococcus, and 5.4 × 10² CFU/mL for Staphylococcus Copper treatment significantly reduced bacterial counts within 15 min. Total bacteria decreased from 4.0 × 10⁶ CFU/mL to 1.1 × 10² CFU/mL after 30 min; meanwhile, other groups were not detected. The most abundant groups were Lactococcus (29.94%), Pseudomonas (28.89%), and Enterobacteriaceae (21.19%). Beta-lactams were detected in five-sevenths samples, and in one sample they were detected before and at 15 min of treatment but not after 30 min. Conclusions: The effect of treatment with copper ions on the different bacterial groups was significantly effective but showed limited effect on the detection of antibiotics. Full article

The aim of this in vitro study was to evaluate the effect of xanthohumol and thymol on the impact of Candida albicans on the structure, size and cell viability of subgingival biofilms formed on dental implant surfaces. The structure and microbial biomass of biofilms developed after 72 h, treated and untreated with both extracts, were compared by scanning electron microscopy (SEM) and confocal laser microscopy (CLSM). Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total microorganisms of each of the biofilm-forming strains in each condition. A general linear model was used to compare and validate the CLSM and qPCR results. The presence of xanthohumol and thymol during biofilm development inhibited the filamentous growth of C. albicans. The biofilm incubated with xanthohumol had significantly lower bacterial biomass and cell viability than the biofilm not exposed to the extract (p < 0.05). In contrast, these global parameters showed no differences when the biofilm was incubated with thymol. In the presence of xanthohumol, there was a decrease in counts and cell viability of Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. Thymol treatment reduced the viability of F. nucleatum and P. gingivalis. The presence of these vegetable extracts during the development of a dynamic in vitro multispecies biofilm model inhibited the filamentous growth of C. albicans, partially reversing the effect that the fungus exerted on the structure, size and vitality of periodontopathogenic bacteria. Full article

Myoglobin (Mb) is easily oxidized, which causes the discoloration of meat. In addition, various microorganisms are responsible for meat spoilage. Chitosan and lycopene can be used to protect the color and extend the shelf life of meat. In this study, a series of coatings with different ratios (1:0, 3:1, 1:1, 1:3, 0:1) of chitosan to lycopene were prepared. Beef was treated with different coatings. The changes in color, relative content of different Mb forms, thiobarbituric acid-reactive substances (TBARS), sulfhydryl content, carbonyl content, microbial count, cooking loss, and sensory evaluation during storage were investigated. The results showed that after 8 days, compared to the control, the relative content of oxymyoglobin (OxyMb), the lightness (L*) value, the redness (a*) value, and the composite index (CI) value of beef treated with chitosan/lycopene of 1:3 (w:w, the concentration of lycopene was 0.75% (w:v)) increased by 6.34%, 34.73%, 67.25%, and 116.27%, respectively. Meanwhile, the relative content of metmyoglobin (MetMb) and the yellowness (b*) value decreased by 11.67% and 23.21%, respectively. Additionally, beef treated with chitosan/lycopene of 1:3 also performed well in protein oxidation, fat oxidation, microbial count, and cooking loss. Generally, the beef treated with chitosan/lycopene of 1:3 showed the best comprehensive quality. The coating was suitable for application in beef. These results are promising for food preservation. Full article

Accurate and efficient quantification of viable bacteria in ready-to-eat food products is crucial for food safety and public health. The rapid and accurate assessment of foodborne bacteria in complex food matrices remains a significant challenge. Herein a culture-based approach was established for easily quantifying viable bacteria in ready-to-eat sea cucumber (RSC) products. Samples of the liquid companion within the package were directly transferred into test tubes to determine bacterial growth curves and growth rate curves, utilizing the electrical microbial growth analyzer. Viable bacteria in the samples were then quantified based on the time required to attain the maximum growth rate indicated on the growth rate curve. At a concentration of 5.0 × 10³ CFU/mL of viable bacteria in the liquid companion, the recovery rates were 108.85–112.77% for Escherichia coli (E. coli) and 107.01–130.54% for Staphylococcus aureus (S. aureus), with standard deviations of 1.60 and 3.92, respectively. For the solid content in the package, the quantification was performed using the same methodology following an additional homogenization step. At a concentration of 5.0 × 10³ CFU/mL of viable bacteria in the sample, the recovery rates were 91.94–102.24% for E. coli and 81.43–104.46% for S. aureus, with standard deviations of 2.34 and 2.38, respectively. In instances where the viable bacterial concentration was 5.0 × 10³ CFU/mL in RSC products, the total time required for the quantification did not exceed 10.5 h. This method demonstrated advantages over traditional plate counting and PCR methods regarding simplicity and efficiency, representing a promising alternative for the quantification of viable bacteria in food like RSC products. Full article

Sandy soils are widespread globally and are increasingly utilized to meet the demands of a growing population and urbanization for food, fiber, energy, and other essential services. However, their poor water and nutrient retention makes crop cultivation challenging. This study evaluated the effects of integrating compost and plant growth-promoting rhizobacteria (PGPR; Azospirillum brasilense SWERI 111 and Azotobacter chroococcum OR512393) on wheat (Triticum aestivum L. var. Misr 1) grown in sandy soil under varying levels of recommended NPK (50%, 75%, and 100%) fertilization. Conducted over two growing seasons, the experiment aimed to assess soil health, nutrient uptake, microbial activity, and plant productivity in response to compost and PGPR treatments. The results demonstrated that combining compost and PGPR significantly improved soil chemical properties, such as reducing soil pH, electrical conductivity (ECe), and sodium adsorption ratio (SAR), while enhancing soil organic matter (SOM). Additionally, compost and PGPR improved soil nutrient content (N, P, K) and boosted the total bacterial and fungal counts. The combined treatment also increased urease and phosphatase enzyme activities, contributing to enhanced nutrient availability. Notably, plant productivity was enhanced with compost and PGPR, reflected by increased chlorophyll and reduced proline content, along with improved grain and straw yields. Overall, the results underscore the potential of compost and PGPR as effective, sustainable soil amendments to support wheat growth under varying NPK levels. Full article

This study investigates the effects of the Bacillus licheniformis (BL) ATCC 21424 strain, as a potential bacterial probiotic in broiler diets based on soybean meal (SBM) or cowpea seeds (CWP), on growth performance (GP), bone mineralization, and intestinal/fecal microbiota status (0 to 42 d age). A 2 × 2 factorial arrangement was employed in a completely randomized design, with four dietary treatments: SBM and CWP diets with or without BL supplementation (1.0 × 10¹¹ CFU spores g⁻¹ feed). A total of 480 one-day-old mixed-sex Ross 308 broiler chickens were randomly assigned to the treatments, with 6 pens of 20 chicks each. The results showed that broilers fed with CWP diets showed comparable body weight gain (BWG), feed intake (FI), and feed conversion rate to those fed the SBM diet (p > 0.05). The inclusion of BL improved BWG during the grower and finisher periods (p = 0.01) and overall study (p < 0.001), resulting in a numerical increase in FI (p = 0.054). In addition, BL in birds’ diets reduced abdominal fat (p = 0.032) and influenced cecum weight (p = 0.040). Additionally, BL improved tibia iron (Fe) and phosphorus (P) bone mineralization and reduced the calcium–phosphorus (Ca:P) ratio (p = 0.0001). Microbial analysis revealed that BL inclusion decreased Coliforms counts in the CWP diet (p = 0.073), reduced E. coli in the ileum (p ≤ 0.05), and lowered Clostridium spp. and Enterococcus spp. in the cecum broilers on SBM diets (p ≤ 0.05). The presence of Staphylococcus spp. in broiler feces was also reduced in both SBM and CWP groups (p < 0.05). In conclusion, the addition of BL to broiler diets enhanced growth performance and bone mineralization and positively influenced gut and excreta bacterial populations in both SBM and CWP diets. Full article

Canada is a leading producer of wild lowbush blueberries, most of which are mechanically harvested, washed, individually quick frozen (IQF), and bulk packaged. Still, some berries are harvested by more gentle methods and sold as fresh-packed products. These berries do not undergo a wash step, nor are subjected to antimicrobial treatments. The purpose of this study was to conduct a microbiological survey of berries harvested in the province of Nova Scotia to assess their potential for harborage of bacterial foodborne pathogens. A combination of standardized plate count methods and 3M-Petrifilm protocols were used to enumerate total aerobic mesophilic bacteria (APC), yeasts and molds (YMC), coliforms, and generic E. coli, the latter being an indicator of fecal contamination. Overall, APC and YMC levels were 1.2 and 0.5 log greater, respectively, for berries collected early in the harvest season versus those acquired late season and varied significantly (p < 0.05) between farm (location) and harvest practices used. Berries harvested by our team using sanitized hand rakes (SH) had consistently lower APC and YMC levels than those harvested by farm crews. Yet, when gentle harvesting (GH) methods (hand-raking, walk-behind or modified mechanical harvesters) were employed on farms, lower numbers were generally observed compared to berries harvested by traditional tractor-mounted mechanized harvesters (MH). The presence of coliforms (and their levels) was also impacted by the harvest method, with detection rates of ~29%, 73%, and 92% in SH, GH, and MH samples, respectively. Mean counts were < 2.5 log₁₀ CFU/g for both SH and GH berries, but significantly higher (p < 0.05) on MH berries (3.6 log₁₀ CFU/g). Although ~56% of all berry samples collected (n = 350) contained coliforms, only 12 were positive for E. coli, 9 of which were MH samples. Only the latter had numbers > 2 log₁₀ CFU/g, but none tested positive for Shiga toxin-producing serotype O157 (STEC O157) or Salmonella spp. when using internationally recognized selective enrichment and plating methods. ATP luminescence was used to assess the general hygiene of processing lines, whereby “hot spots” for microbial activity were identified, even after cleaning., Standard selective enrichment and plating methods were used for the detection of Listeria monocytogenes on 61 swab samples taken from berry totes or conveyor belts at different times during processing; 4 swabs tested positive for L. monocytogenes. However, the pathogen could not be detected by direct plating on selective agar without prior enrichment; this indicated its numbers were low. The results from this work demonstrated that alternative gentle harvest methods can reduce microbial numbers on wild blueberries. Although the frequency of fecal contamination in berry samples appeared to be low and targeted human pathogens were not detected; this represents a single study conducted over one harvest season. Therefore, it would be prudent for processors to seek effective antimicrobial technologies prior to packaging, while consumers should use caution and thoroughly wash produce before consumption. Where sporadic detection of L. monocytogenes was observed on environmental samples from the processing line, processors must ensure that effective sanitation programs are implemented to avoid potential food safety risks. Full article

This study aims to assess the capability of using a specially designed device to monitor changes in gas concentration (CO₂, NH₃, H₂S, and O₂) in the atmosphere above the minced beef meat, during storage at refrigerated temperature. With its array of sensing channels, the multi-gas detector device facilitates the detection of precise gas concentrations in sensitive environments, enabling the monitoring of various processes occurring within stored meat. To delve into the connection between microbial activity and gas emissions during storage, fluctuations in microbial populations in the meat were observed, focusing on prevalent meat microbiota such as lactic acid bacteria (LAB) and Enterobacteriaceae. A significant reduction of O₂ content in the stored samples was observed after seven days (p < 0.05), while a significant release of CO₂ was detected on the fourth day of storage. Significant changes (p < 0.05) in the gas content were tracked until the 11th day of storage followed by intensive microbial growth. NH₃ and H₂S levels remained undetectable throughout the experiment. The results showed a correlation between an increase in gas content in the headspace and an increase in the number of LAB and Enterobacteriaceae in meat. Modern multi-gas detector devices can indirectly determine microbial contamination in closed meat packaging. Full article

The purpose of the current research was to evaluate the influence of lactic acid bacteria and cellulase supplementation on the chemical composition, fermentation parameters, aerobic stability, microbial count, and in vitro nutrients digestibility of silage prepared with Pennisetum giganteum and rice straw. This study consisted of four treatments: a control group with no additive supplementation (CON), a lactic acid bacteria supplementation group (LAB), a cellulase supplementation group (CEL), and a combined supplementation group (LAC). After ensiling for 60 d, the chemical composition, fermentation parameters, microbial count, and aerobic stability were determined. Additionally, ruminal fermentation characteristics were evaluated by an in vitro incubation technique. Compared with CON silage, the quality of LAB and CEL silages was enhanced to a certain degree. Combined supplementation with lactic acid bacteria and cellulase in mixed silage of Pennisetum giganteum and rice straw noticeably increased (p < 0.05) the dry matter, crude protein, and lactic acid contents, whereas it reduced (p < 0.05) the pH and ammonia nitrogen/total nitrogen as well as the neutral detergent fiber and acid detergent fiber concentrations. The lactic acid bacteria count in LAC silage was higher (p < 0.05) than that of CON silage, whereas an opposite trend of yeast, aerobic bacteria, and mold was observed between the two groups. The aerobic stability time, in vitro crude protein, and neutral detergent fiber digestibility in LAC silage were significantly increased (p < 0.05) compared with those in CON silage. Moreover, the in vitro ruminal ammonia nitrogen content was reduced (p < 0.05), and the microbial protein and propionic acid concentrations were increased (p < 0.05) in silage after combined inoculation with additives. Taken together, the quality of Pennisetum giganteum and rice straw mixed silage can be improved by inoculation with lactic acid bacteria and cellulase, and combined supplementation shows the greatest improvement in silage quality. Full article

The application of chlorine dioxide (ClO₂) in microbial safety and quality maintenance of fresh produce has received extensive attention. Fresh-cut button mushrooms (Agaricus bisporus) are prone to spoilage, resulting in a short shelf-life. In this study, ClO₂ treatment was used to preserve fresh-cut button mushrooms, and its effect on maintaining the postharvest quality was investigated using sensory evaluation, weight loss, color, firmness, respiration rate, electronic-nose (E-nose) analysis and microbial analysis. During the 8 d storage, both the 50 and 100 mg·L⁻¹ ClO₂ treatment reduced the aerobic bacteria count on the surface of fresh-cut button mushrooms. However, the results showed that the 50 mg·L⁻¹ ClO₂ treatment but not the 100 mg·L⁻¹ ClO₂ treatment significantly inhibited the deterioration of comprehensive quality. The 50 mg·L⁻¹ ClO₂ treatment maintained the high sensory evaluation and pleasant volatile odor of fresh-cut button mushrooms as well as reduced the decreasing of fresh weight and firmness. Contrary to expectations, the application of ClO₂ treatment showed worse appearances in color (lower L^*, higher a^*, b^* and browning index) of fresh-cut button mushrooms. Significant differences were observed between CK and ClO₂-treated groups from day 0 to day 6, while there were no significant differences of a^*, b^* and browning index between CK and the 50 mg·L⁻¹ ClO₂ treatment at the end of storage (on day 8). In conclusion, the 50 mg·L⁻¹ ClO₂ can maintain the good quality of fresh-cut button mushrooms. Full article

This study investigates the efficacy of ozone treatment combined with different packaging methods on the preservation of Taiwanese domestically produced beef during refrigerated storage. The preservation of fresh beef is crucial for ensuring food safety and quality; we do not know whether changing the packaging method can mitigate the negative effects of ozone on meat and even enhance its positive impact. Beef samples were treated with ozone and packaged using the vacuum or PVDC-tray methods, then stored at 4 °C for 7 days. The results show that ozone treatment effectively inhibited microbial (total plate count, Salmonella, and Escherichia coli) growth (p < 0.05). Vacuum packaging maintained lower TBARS values (p < 0.05) and metmyoglobin percentages compared to PVDC-tray packaging (p < 0.05). The L* values of all treatments increased over storage time, with significant differences observed between days 0 and 7. Ozone treatment combined with vacuum packaging demonstrated promising results in inhibiting microbial growth and preserving beef quality during refrigerated storage. These findings contribute to enhancing the safety and shelf life of Taiwanese domestically produced beef, potentially benefiting both producers and consumers. Full article

Postharvest Agaricus bisporus is susceptible to browning, water loss, and microbial infection. In order to extend its shelf life, cold plasma technology was used to treat and evaluate A. bisporus. Firstly, according to the results of a single factor test and response surface analysis, the optimal conditions for cold plasma treatment were determined as a voltage of 95 kV, a frequency of 130 Hz, and a processing time of 10 min. Secondly, storage experiments were carried out using the optimized cold plasma treatment. The results showed that the cold plasma treatment in the packaging significantly reduced the total viable count in A. bisporus by approximately 16.5%, maintained a browning degree at 26.9% lower than that of the control group, and a hardness at 25.6% higher than that of the control group. In addition, the cold plasma treatment also helped to preserve the vitamin C and total protein content of A. bisporus. In conclusion, cold plasma treatment showed great potential in enhancing the postharvest quality of fresh A. bisporus. Full article