Lower Microbial Load Research Articles

Effect of titanium coated with 3 different types of copper nanoparticles in the oral biofilm formation

The antimicrobial activity of copper nanoparticles (CuNps) has been studied against different pathogenic microorganisms, however to our knowledge, no studies have been reported about their activity against periodontal bacteria in a biofilm. Therefore, in order to bridge this information gap, this study aims to observe and count the formation of oral biofilm on titanium alloys coated with different types of CuNps. Three different methods were used to synthetize and then apply a coating of CuNps on dental implant healing caps, by then, their antibacterial properties were investigated using an in vitro oral biofilm by plate count method and confocal laser microscopy. The result of the counts, showed that the lower microbial load is observed in the caps coated with CuNps obtained by copper electroplating, it can be concluded, within the limitations of this study, that CuNps obtained by copper electroplating showed greater bactericidal effect that PVD methods, especially in periodontal pathogenic bacteria like P.gingivalis, and P. intermedia. More studies are necessary for corroborate this observation and better understand the reason why only CuNps obtained by certain methods were more bactericidal tan others and the reason why only some bacteria were affected. The antimicrobial properties exhibited by CuNps could be useful for develop anti-infective biomaterials become a strategy to control dental biofilm.

Microbiological Changes During Storage of Extruded Snacks Produced from Yellow Cassava Substituted with Processed Sesame Seeds Flours

As the need for healthy snack consumption is rising on a daily basis, evaluating its storability is also needful. This study was done to examine the storability of extruded snacks developed from yellow cassava substituted with sesame seed flour blends. Germinated and fermented sesame seed flours were blended with yellow cassava flour differently at 0, 15 and 30% levels of substitution. The flours were appropriately mixed for the production of extruded snacks in using single screw extruder before frying in a deep fryer. The snacks were packaged in polythene and stored at room temperature. Microbial evaluation was carried out on the snacks on weekly basis for four weeks to determine their storability. The initial counts of total aerobic, fungi (yeast and mould) and coliform counts ranged from 0.48x104 to 2.55x104, 1.06x104 to 2.56x104 and 8.00x102 to 1.20x103cfu/g respectively. The samples showed significant differences (p<0.05). The values increased as the length of day increases with samples containing germinated sesame seeds flour having the highest while the extruded snacks with 0% sesame seeds flour had the lowest counts. The samples with fermented sesame seeds flours were observed to contain lower microbial loads compare to those with germinated sesame seeds flour. The results of this study nevertheless indicated that the level of contamination of the snacks were within acceptable/specified limits.

Production, Microbiological and Organoleptic Properties of Stored Cocoyam-based Products

The production, microbiological and organoleptic properties of stored cocoyam-based products were carried out. A-5 kg corms were sorted, washed and boiled for 3 hours and was cooled, peeled and cut into small sizes of average of 2.0 cm by 1.5 cm dimension with a sharp kitchen knife; dried under the sun for 5 days. The dried corms (<i>achicha</i>) were pulverized with a locally fabricated machine and stored in plastic containers for 0, 1, 2, 3 month (s) intervals. A-300 g of cocoyam leaves were plucked, sorted, washed, and sun-dried for 3 days. The <i>mpoto</i> were pulverized with a locally fabricated machine and stored in plastic containers for 0, 1, 2, 3 months. After 3 months’ storage, the total viable counts (TVC) and total fungi counts (TFC) of <i>achicha</i> were as follows: <i>edeofe</i> (2.8×10⁴ <i>cfu/g</i>), <i>cocoindia</i> (3.4×10⁴ <i>cfu/g</i>) and <i>anampu</i> (2.4×10⁴ <i>cfu/g</i>); and <i>edeofe</i> (1.4×10⁴ <i>cfu/g</i>), <i>cocoindia</i> (1.7×10⁴ <i>cfu/g</i>) and <i>anampu</i> (0.8×10⁴ <i>cfu/g</i>) respectively. The TVC and TFC of <i>mpoto</i> stored for 3 months were as follows: <i>edeofe</i> (2.7×10⁴ <i>cfu/g</i>), <i>cocoindia</i> (2.1×10⁴ <i>cfu/g</i>) and <i>anampu</i> (1.4×10⁴ <i>cfu/g</i>); and <i>edeofe</i> (1.0×10⁴ <i>cfu/g</i>), <i>cocoindia</i> (0.5×10⁴ <i>cfu/g</i>) and <i>anampu</i> (0.5×10⁴ <i>cfu/g</i>) respectively. The bacteria isolated and identified were <i>Bacillus</i> spp in <i>edeofe</i> and <i>cocoindia</i> of <i>achicha</i> and <i>mpoto</i>; <i>Staphylococcus</i> spp in <i>anampu</i> of <i>achicha</i> and <i>cocoindia</i> of <i>mpoto</i> and <i>Escherichia coli</i> in <i>anampu</i> of <i>achicha</i> and <i>edeofe</i> of <i>mpoto</i>. <i>Penicillum</i>, <i>Rhizopus</i> and <i>Aspergillus</i> spp were also identified in <i>achicha</i> and <i>mpoto</i> of all the varieties. The organoleptic properties of <i>achicha</i> and <i>mpoto</i> scored approximately 8.00 (like very much) which showed that the products were generally accepted due to low microbial loads and high preference on the desired attributes of <i>achicha</i> and <i>mpoto</i>. It is recommendable to use the tubers and the leaves in food preparations for human consumption.

Optimal thermoultrasound processing of jackfruit ( Artocarpus heterophyllus lam.) nectar: Physicochemical characteristics, antioxidant properties, microbial quality, and fatty acid profile comparison with pasteurized nectar

The objective of this study was to determine the optimal thermoultrasound processing conditions for jackfruit nectar by applying response surface methodology and comparing the physicochemical parameters, antioxidant properties, microbiology, and fatty acid profile with pasteurized jackfruit nectar. Optimal condition was 80% of amplitude at 45 ± 1°C for 20 ± 1 min, allowing physical stability of 68%, 60% of pectin methylesterase activity, ascorbic acid of 420 mg AA/L, total phenolic of 134 mg GAE/L, ABTS, DPPH, and chelating activity of 3,510 µmol TE/L, 75 µmol TE/L, and 96%, respectively. The thermoultrasonicated jackfruit nectar had lower microbial load and higher total soluble solids, ascorbic acid content, total phenolic content, antioxidant activity than pasteurized, and similar unsaturated fatty acids to the untreated sample. Our results demonstrated that thermoultrasound could be an option for processing jackfruit nectar as an alternative to pasteurization that allows successful inactivation of microorganisms, inactivation of enzymes, and good quality parameters. Practical applications Based on consumer demand for more natural or fresh-like products, alternative technologies have been evaluated by research works looking to reduce the effects of heat treatments in the Food Industry. Among these technologies, thermoultrasound technology have gained relevance and seems to be a good replacement to inactivate microorganisms and enzymes without affecting the quality parameters, maintaining the unsaturated fatty acids content, and even increasing bioactive compounds. For example, the thermoultrasound application in jackfruit nectar has been demonstrated as a viable preservation technique to develop an innocuous nectar without affecting their food quality. Nevertheless, in order to solve the challenges about potential applications of ultrasound technology, further research is needed to obtain optimal processing conditions according to the food matrix quality required.

Comparative Effects of Different Organic and Inorganic Fertilisers on Soil Fertility, Plant Growth, Soil Microbial Community, and Storage Ability of Lettuce

Abstract The current study was conducted to assess whether organic fertilisation could replace mineral fertilisation in lettuce production without adverse effects on yield, quality, and postharvest behaviour. The effect of either mineral or organic fertiliser on soil fertility or the microbial community was also studied. Control plots were fertilised with recommended rates of mineral fertiliser (150: 45: 65 kg/ha NPK) and the other treatments were 15 t/ha compost, 10 t/ha rabbit manure, and 10 t/ha chicken manure. Our results indicated that all sources of organic fertiliser significantly increased total nitrogen, organic carbon, total fungi, and bacteria contents of soils compared with mineral fertiliser. Rabbit and chicken manure fertilisers resulted in a significant increase in yield. Compared with conventional fertiliser and other organic treatments, plots receiving rabbit manure showed a lower weight loss and microbial load on fresh lettuce head. Moreover, rabbit manure significantly reduced polyphenol oxidase and peroxidase activity. Hence, these results suggest that rabbit manure fertiliser could be an alternative to conventional production without significant reduction in yield and with low enzymatic browning and better storability.

Antibacterial potential of donkey’s milk disclosed by untargeted proteomics

Donkey's milk (DM) has been extensively investigated as a valuable substitute of breast milk, often suitable to manage cow's milk protein allergy in infants. DM exhibits potent inhibitory properties against numerous microbial species. Although oligosaccharides and lipids might contribute to the antimicrobial potential, the current inventory of proteins is not able to justify the low count of microorganisms generally observed in DM.The shotgun proteomic analysis of fractionated DM disclosed a set of 94 gene products, 41% of which have documented antimicrobial activity or are involved in transferring the passive immunity to the donkey offspring. The concerted action of lysozyme, lactoferrin, immunoglobulins provides the molecular basis for part of the DM antibacterial potential. The pH -4.6 insoluble fraction contained significant levels of L-amino acid oxidase, identified with 11 unique peptides matching the horse homologue gene product. This enzyme catalyses the oxidative deamination of amino acids into ketoacids, producing ammonia and H2O2. κ-casein, likely occurring as a fully O-glycosylated protein, may concur to inhibit the adhesion of pathogenic microorganisms, along with other glycoproteins.Proteomics supports the alimentary use of DM not only as a substitute of human milk in early infancy, but also for growing children, convalescent, elderly people and general population. SignificanceDonkey's milk (DM) is acquiring increasing popularity because it is a suitable substitute of the human milk, when breastfeeding is not possible and infants suffer from cow's milk allergy.DM is characterized by a much lower microbial load compared to ruminants' milk. This feature has been traditionally attributed to the high content of lysozyme. DM exhibits potent activity against a broad range of bacteria, viruses and fungi, suggesting that other protein components can be responsible of the antimicrobial potential. The gel-free proteomic analysis of pH 4.6-insoluble and soluble (whey) fractions demonstrated that DM contains a large number of gene products involved in antimicrobial mechanisms and in transferring passive immunity to the donkey offspring.DM contains relatively high levels of L-amino acid oxidase that catalyses the oxidative deamination of amino acid substrates into ketoacids, with production of ammonia and H2O2. In combination with lysozyme, lactoferrin and immunoglobulins, the presence of L-amino acid oxidase provides the molecular basis of the antibacterial potential observed for DM. Considered the low microbial load, DM can be sanitated at mild conditions, thereby preserving many of the native nutritional traits.Thus, DM can be considered a safe and nutritionally valid alimentary resource for growing children, convalescent, elderly people and general population.Data of this study represent the largest inventory of proteins identified in Equidae milk, so far.

Bacterial and oxidative control of local butter with smart/active film based on pectin/nanoclay/Carum copticum essential oils/β-carotene

In this study, Pectin/Nanoclay (montmorillonite)/Carum copticum Essential oils/β-Carotene (Pec/Clay/CCE/βC) composite film was prepared. The effect of β-Carotene (βC) and Carum copticum Essential oils (CCE) concentration on the antioxidant activity and color/mechanical properties of Pec/Clay/CCE/βC film was studied. The morphology and antibacterial activity of film were studied. The films containing maximum essential oil and β-carotene showed the best antibacterial activity, antioxidant activity, flexibility and firmness. So the Pec/Clay/CCE0.5%/BC0.03% film as the optimum film was used for packaging of local butter. Oxidative stability, microbial count, and color properties (L*, a* and b*) of butter packaged with active film (Pec/Clay/CCE/βC) were investigated. Results showed that Pec/Clay/CCE/βC film was effective against Bacillus cereus (B. cereus) more than Escherichia coli (E. coli). According to the results active packaged butter had the highest oxidative stability, lowest microbial load, and the least color change during storage. In the packaging process, Pec/Clay/CCE/βC film color was changed from orange to light yellow and this color change was used as a smart color indicator to detect the oxidation of butter and expiration time of butter.

Optimization of a Method for the Concentration of Genetic Material in Bacterial and Fungal Communities on Fresh Apple Peel Surfaces.

Apples are the most consumed fruit in the United States and have recently been shown to exhibit some vulnerability to contamination across the supply chain. It is unclear what role a fruit microbiome analysis may serve in future food safety programs interested in understanding changes in the product and the processing environment. Ultimately, sample integrity is key if any of these approaches are to be employed; low microbial loads on apple surfaces, the inability to sample the entire surface, and inefficiency of removal may act as barriers to achieving high-quality DNA. As such, the objective of this study was to identify a reproducible method to concentrate and quantify bacterial and fungal DNA from fresh apple surfaces. Five methods were evaluated: two variations of wash solutions for bath sonication, wash filtration, epidermis excision, and surface swabbing. Epidermis excision returned the highest mean DNA quantities, followed by the sonicated washes and wash filtration. Surface swabbing was consistently below the limit of detection. Based on the quantity of host DNA contamination in surface excision, the sonicated wash solution containing a surfactant presents the greatest opportunity for consistent, high-yielding DNA recovery from the entire apple surface.

Ultrasonic potential in maintaining the quality and reducing the microbial load of minimally processed pomegranate

Difficulty of Pomegranate fruit peeling and arils separation are the main motivations of progressive ready-to-eat pomegranate fresh arils industry. Also, extracted pomegranate arils are highly perishable due to water loss and microbial contamination expose. The aim of the current work was then to evaluate the effect of ultrasound for 15 and 30 min on maintenance of bioactive compounds and microbial load reduction of pomegranate arils cv. Rabbab. Treated arils were kept at 5 °C and analyzed during 15 days of storage. The most and least weight loss of arils obtained in control and 30 min treated samples, respectively. After 12 days of storage, all samples were decayed except those treated for 15 and 30 min. The ultrasound treatment significantly prevented degradation of anthocyanin and ascorbic acid compounds. Total phenol and antioxidant activity decreased during storage. At the end of storage, the most total phenol content (3898.6 mg GAE L−1) was found in arils treated for 30 min whereas the most anthocyanin (91.93 mg L−1), total antioxidant activity (82.65%), and ascorbic acid (2.53 mg L−1) were found in arils treated for 15 min. Ultrasound treated arils had lower microbial load (total mesophilic bacteria in control and 30-min treated samples) in each stage during storage. At the end of storage, the microbial load in treated and control arils was 0.7 and 0.2 Log CFU g−1, respectively). Overall, ultrasound treatment effectively reduced weight loss and preserved bioactive compounds during storage.

Geochemistry and Microbiology Predict Environmental Niches With Conditions Favoring Potential Microbial Activity in the Bakken Shale.

The Bakken Shale and underlying Three Forks Formation is an important oil and gas reservoir in the United States. The hydrocarbon resources in this region are accessible using unconventional oil and gas extraction methods, including horizontal drilling and hydraulic fracturing. However, the geochemistry and microbiology of this region are not well understood, although they are known to have major implications for productivity and water management. In this study, we analyzed the produced water from 14 unconventional wells in the Bakken Shale using geochemical measurements, quantitative PCR (qPCR), and 16S rRNA gene sequencing with the overall goal of understanding the complex dynamics present in hydraulically fractured wells. Bakken Shale produced waters from this study exhibit high measurements of total dissolved solids (TDS). These conditions inhibit microbial growth, such that all samples had low microbial loads except for one sample (well 11), which had lower TDS concentrations and higher 16S rRNA gene copies. Our produced water samples had elevated chloride concentrations typical of other Bakken waters. However, they also contained a sulfate concentration trend that suggested higher occurrence of sulfate reduction, especially in wells 11 and 18. The unique geochemistry and microbial loads recorded for wells 11 and 18 suggest that the heterogeneous nature of the producing formation can provide environmental niches with conditions conducive for microbial growth. This was supported by strong correlations between the produced water microbial community and the associated geochemical parameters including sodium, chloride, and sulfate concentrations. The produced water microbial community was dominated by 19 bacterial families, all of which have previously been associated with hydrocarbon-reservoirs. These families include Halanaerobiaceae, Pseudomonadaceae, and Desulfohalobiaceae which are often associated with thiosulfate reduction, biofilm production, and sulfate reduction, respectively. Notably, well 11 was dominated by sulfate reducers. Our findings expand the current understanding of microbial life in the Bakken region and provide new insights into how the unique produced water conditions shape microbial communities. Finally, our analysis suggests that produced water chemistry is tightly linked with microbiota in the Bakken Shale and shows that additional research efforts that incorporate coupled microbial and geochemical datasets are necessary to understand this ecosystem.

Use of Essential Oils to Increase the Safety and the Quality of Marinated Pork Loin.

This study aimed at evaluating the effects of the addition of an oil/beer/lemon marinade solution with or without the inclusion of oregano, rosemary and juniper essential oils on the quality, the technological properties as well as the shelf-life and safety of vacuum-packed pork loin meat. The results obtained suggested that, aside from the addition of essential oils, the marination process allowed to reduce meat pH, thus improving its water holding capacity. Instrumental and sensorial tests showed that the marination also enhanced the tenderness of meat samples, with those marinated with essential oils being the most positively perceived by the panelists. In addition, microbiological data indicated that the marinated samples showed a lower microbial load of the main spoiling microorganisms compared to the control samples, from the 6th to the 13th day of storage, regardless of the addition of essential oils. Marination also allowed to inhibit the pathogens Salmonella enteritidis, Listeria monocytogenes and Staphylococcus aureus, thus increasing the microbiological safety of the product. Overall outcomes suggest that the oil/beer/lemon marinade solution added with essential oils might represent a promising strategy to improve both qualitative and sensory characteristics as well as the safety of meat products.

Chemical and microbial evaluation of biscuits made from wheat flour substituted with wheat sprouts.

The aim of this work was to produce biscuits from wheat flour substituted with different amounts of wheat sprout powder (2.5-7.5%). The biscuits were subjected to chemical, phytochemical, and microbial evaluations. The crude protein, fat, and ash contents and the energy value of the biscuits increased with increasing percentage of wheat sprout powder. Adding sprouts resulted in higher values of phenolics, alpha-tocopherol, and antioxidant activity. There was no statistically significant difference in the contents of total phenolics and alpha-tocopherol between biscuits supplemented with 5% sprouts and biscuits substituted with 7.5% sprouts. The phenolic content in biscuits containing 7.5% sprouts was 245 mg gallic acid equivalents (GAE)/100 g dm compared with 110 mg GAE/100 g dm in control biscuits. Antioxidant activity was the highest in biscuits substituted with 7.5% sprouts. All levels of substitution of wheat flour with wheat sprouts had an effect on the nutritional properties of biscuits, but the substitution level of 2.5-5% is recommended for the improvement of their sensorial properties. The biscuits produced had a low microbial load and were microbiologically safe. Escherichia coli, Salmonella spp., and sulfite-reduction clostridia were not detected in any sample during the period of investigation from 2 to 60 days of storage.

Antibiotic administration reduces the rate of intraamniotic inflammation in preterm prelabor rupture of the membranes

Preterm prelabor rupture of the membranes (PPROM) is frequently complicated by intraamniotic inflammatory processes such as intraamniotic infection and sterile intraamniotic inflammation. Antibiotic therapy is recommended to patients with PPROM to prolong the interval between this complication and delivery (latency period), reduce the risk of clinical chorioamnionitis, and improve neonatal outcome. However, there is a lack of information regarding whether the administration of antibiotics can reduce the intensity of the intraamniotic inflammatory response or eradicate microorganisms in patients with PPROM. The first aim of the study was to determine whether antimicrobial agents can reduce the magnitude of the intraamniotic inflammatory response in patients with PPROM by assessing the concentrations of interleukin-6 in amniotic fluid before and after antibiotic treatment. The second aim was to determine whether treatment with intravenous clarithromycin changes the microbial load of Ureaplasma spp DNA in amniotic fluid. A retrospective cohort study included patients who had (1) a singleton gestation, (2) PPROM between 24+0 and 33+6 weeks, (3) a transabdominal amniocentesis at the time of admission, and (4) intravenous antibiotic treatment (clarithromycin for patients with intraamniotic inflammation and benzylpenicillin/clindamycin in the cases of allergy in patients without intraamniotic inflammation) for 7 days. Follow-up amniocenteses (7th day after admission) were performed in the subset of patients with a latency period lasting longer than 7 days. Concentrations of interleukin-6 were measured in the samples of amniotic fluid with a bedside test, and the presence of microbial invasion of the amniotic cavity was assessed with culture and molecular microbiological methods. Intraamniotic inflammation was defined as a bedside interleukin-6 concentration ≥745 pg/mL in the samples of amniotic fluid. Intraamniotic infection was defined as the presence of both microbial invasion of the amniotic cavity and intraamniotic inflammation; sterile intraamniotic inflammation was defined as the presenceof intraamniotic inflammation without microbial invasion of the amniotic cavity. A total of 270 patients with PPROM were included in this study: 207 patients delivered within 7 days and 63 patients delivered after 7 days of admission. Of the 63 patients who delivered after 7 days following the initial amniocentesis, 40 underwent a follow-up amniocentesis. Patients with intraamniotic infection (n= 7) and sterile intraamniotic inflammation (n= 7) were treated with intravenous clarithromycin. Patients without either microbial invasion of the amniotic cavity or intraamniotic inflammation (n= 26) were treated with benzylpenicillin or clindamycin. Treatment with clarithromycin decreased the interleukin-6 concentration in amniotic fluid at the follow-up amniocentesis compared to the initial amniocentesis in patients with intraamniotic infection (follow-up: median, 295 pg/mL, interquartile range [IQR], 72-673 vs initial: median, 2973 pg/mL, IQR, 1750-6296; P= .02) and in those with sterile intraamniotic inflammation (follow-up: median, 221 pg/mL, IQR 118-366 pg/mL vs initial: median, 1446 pg/mL, IQR, 1300-2941; P= .02). Samples of amniotic fluid with Ureaplasma spp DNA had a lower microbial load at the time offollow-up amniocentesis compared to the initial amniocentesis (follow-up: median, 1.8× 104 copies DNA/mL, 2.9× 104 to 6.7× 108 vs initial: median, 4.7× 107 copies DNA/mL, interquartile range, 2.9× 103 to 3.6× 107; P= .03). Intravenous therapy with clarithromycin was associated with a reduction in the intensity of the intraamniotic inflammatory response in patients with PPROM with either intraamniotic infection or sterile intraamniotic inflammation. Moreover, treatment with clarithromycin was related to a reduction in the load of Ureaplasma spp DNA in the amniotic fluid of patients with PPROM <34 weeks of gestation.

Influence of Ocimum gratissimum (Scent Leaf) on the Organoleptic Acceptability and Shelf Stability of Yoghurt

Aim: To investigate the preservative efficiency of Ocimum gratissimum or its extracts on yoghurt.&#x0D; Study Design: Ten yoghurt samples were prepared, furthermore, nine (9) samples were treated with scent leaf in different forms at different concentrations.&#x0D; Place and Duration of Study: Department of Food Science and Technology, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria, between September 2015 and June 2016.&#x0D; Methodology: Yoghurt was prepared from instant filled milk while Direct Vat Inoculum (DVI) was used as the starter culture. Proximate and phytochemical analyses were carried out following standard procedures. Sensory evaluation was carried out using a 15-man panelist with a seven point hedonic scales and results were statistically analyzed using IBM® SPSS 21.0, at 0.05 probability level. pH and microbial analysis were conducted while bacterial characterization involved biochemical tests and isolation of probable microorganisms employed morphological and structural characteristics.&#x0D; Results: Result for proximate analysis indicated differences in the nutritional composition of the raw milk and yoghurt (control). Moisture content increased considerably from 10.00% to 69.75%, while a reduction in protein content was reported (8.7% - 4.95%). The lipid content classified the produced yoghurt as a low-fat yoghurt, and expectedly, the carbohydrate content reduced from 58.20% - 22.30%. Phytochemical screening of the different forms of scent leaf indicated the presence of alkaloids, flavonoids, saponins, cardiac glycosides, and steroids, in different concentrations. Sensory scores showed that the panelists preferred yoghurt formulated with 3 mL of squeezed scent leaf extract. pH values decreased with storage period, while microbial load ranged between 0.5× 104 – 2.0 × 104, where Klebsiella spp., Streptococcus spp., E. coli, Bacillus, S. aureus, Pseudomonas spp., Enterobacter, and Proteus spp. were isolated.&#x0D; Conclusion: The yoghurt samples formulated with squeezed scent leaf extracts had the best organoleptic acceptance, while the sample treated with 3 mL had the lowest microbial load, hence, it can be inferred that the squeezed scent leaf extracts had the best preservative effect.

Influence of Meat Spoilage Microbiota Initial Load on the Growth and Survival of Three Pathogens on a Naturally Fermented Sausage.

Meat products are potential vehicles for transmitting foodborne pathogens like Salmonella, S. aureus, and L. monocytogenes. We aimed to evaluate (1) the effect of the meat’s initial natural microbiota on Salmonella, S. aureus, and L. monocytogenes growth and survival in a batter to prepare a naturally fermented sausage, made with and without curing salts and wine (2) the effect of a lactic acid bacteria (LAB) starter culture and wine on the survival of the three pathogens during the manufacturing of a naturally fermented sausage made with meat with a low initial microbial load. The results revealed that the reduced contamination that is currently expected in raw meat is favorable for the multiplication of pathogens due to reduced competition. The inhibitory effect of nitrite and nitrate on Salmonella, S. aureus, and L. monocytogenes was confirmed, particularly when competition in meat was low. In any attempt to reduce or eliminate nitrite from naturally fermented sausages, the use of LAB starters should be considered to ensure an unfavorable competition environment for pathogens. In the experiment with naturally fermented sausage, chouriço, the reduction in aw strongly inhibited the challenged pathogens, particularly when a LAB starter culture and wine were used.

Combining whole-genome shotgun sequencing and rRNA gene amplicon analyses to improve detection of microbe\u2013microbe interaction networks in plant leaves

Microorganisms from all domains of life establish associations with plants. Although some harm the plant, others antagonize pathogens or prime the plant immune system, support the acquisition of nutrients, tune plant hormone levels, or perform additional services. Most culture-independent plant microbiome research has focused on amplicon sequencing of the 16S rRNA gene and/or the internal transcribed spacer (ITS) of rRNA genomic loci, which show the relative abundance of the microbes to each other. Here, we describe shotgun sequencing of 275 wild Arabidopsis thaliana leaf microbiomes from southwest Germany, with additional bacterial 16S and eukaryotic ITS1 rRNA amplicon data from 176 of these samples. Shotgun data, which unlike the amplicon data capture the ratio of microbe to plant DNA, enable scaling of microbial read abundances to reflect the microbial load on the host. In a more cost-effective hybrid strategy, we show they also allow a similar scaling of amplicon data to overcome compositionality problems. Our wild plants were dominated by bacterial sequences, with eukaryotes contributing only a minority of reads. Microbial membership showed weak associations with both site of origin and plant genotype, both of which were highly confounded in this dataset. There was large variation among microbiomes, with one extreme comprising samples of low complexity and a high load of microorganisms typical of infected plants, and the other extreme being samples of high complexity and a low microbial load. Critically, considering absolute microbial load led to fundamentally different conclusions about microbiome assembly and the interaction networks among major taxa.

Ensuring the best storage temperature of Egyptian pastrami based on microbiological, physico-chemical and sensory evaluation

Egyptian pastrami is among the most important and widely consumed meat products in Egypt and due to the great defects in its storage as a ready-to-eat products by retailers, distributers or even consumers, the aim of the current research is to assess the effect of storage temperatures on physico-chemical, microbiological, and sensory properties of Egyptian pastrami using autoclaved non-meat ingredients to ensure the best storage temperature of such important food. Four storage temperatures were applied including room temperature during summer (25 °C), room temperature during winter (15 °C), in fridge at 4 °C and in freezer at −18 °C for a period of 60 days using whole unsliced produced pastrami arms. The findings showed that there was no significant effect (P > 0.05) of storage temperatures on the physico-chemical and sensory properties of tested Egyptian pastrami as the four types were highly accepted based on the physico-chemical and sensory evaluation. Meanwhile, there was noticeable effect of storage temperatures on the microbiological properties of the four manufactured types of pastrami, as the samples stored at −18 °C or at 4 °C for 60 days had the lowest microbial loads and was the best from microbiological aspect.

Quality Evaluation of Fresh Papaya Fruits Stored in Evaporative Coolers

A study was conducted to assess the performance of evaporative coolers for the storage of fruits and vegetables. The evaporative coolers used for this study consist of double-walled rectangular brick construction (1.29 × 2.55 × 2.56) m external and (1.13 × 1.27 × 2.08) m, internal, (length × width × height) with the inter-space filled with river bed sand saturated with water. In this study, ambient storage temperature ranged from 26.6 to 28.7oC with relative humidity which ranged from 64.7 to 85.2 percent. However, NBBEC storage recorded lower temperature within the range of 24.3 to 25.3oC and relative humidity which ranged from 88.8 to 91.2 percent while ABBEC storage recorded the least temperature which ranged from 23.0 to 24.1oC with highest relative humidity which ranged from 91.4 to 92.8 percent. The papaya fruits stored in the coolers and in ambient were evaluated for weight loss, total soluble solids, pH, total titratable acidity, ascorbic acid, beta carotene content and microbial load. TTA, ascorbic acid, beta carotene decreased; while pH and TSS increased with storage period. In ambient storage, fresh papaya fruits stored in evaporative coolers have lower microbial load compared to ambient storage with aluminum cladding of the cooler (ABBEC) further improving microbial quality and shelf life. The pawpaw fruits stored in the aluminum cladded burnt-clay-brick evaporative cooler (ABBEC) remained fresh and firm for ten days compared to three days in non-cladded burnt-clay-brick evaporative cooler (NBBEC) and four days in ambient storage.

Shelf-life of refrigerated Asian sea bass slices treated with cold plasma as affected by gas composition in packaging

Effect of in-bag dielectric barrier discharge cold plasma (IB-DBD-CP) on the keeping quality of Asian sea bass slices (ASBS) packaged under different gases during refrigerated storage at 4 °C was studied. ASBS without and with IB-DBD-CP treatment packaged under the gas combination of argon and oxygen (10:90) (gas A) or the mixtures of carbon dioxide, argon and oxygen (60:30:10) (gas B) and the control (kept in air) were monitored for quality changes up to 18 days. ASBS treated with IB-DBD-CP, regardless of gas composition, had lower microbial loads than those without treatment and the control (p < 0.05). The shelf-life of ASBS was prolonged to 9 and 12 days after being packaged under gas A and B, respectively without IB-DBD-CP treatment, while 6 days were recorded for the control. However, ASBS treated with IB-DBD-CP, packaged under gas A and B had the shelf-life of 12 and 15 days, respectively. Throughout the storage, trimethylamine content and total volatile nitrogen base content were lower in ASBS treated with IB-DBD-CP, particularly those packaged under gas B than that without treatment and the control (p < 0.05). Nevertheless, lipid oxidation as well as protein oxidation were higher in samples treated with IB-DBD-CP, regardless of gas composition used, in comparison with untreated counterpart. Therefore, IB-DBD-CP of ASBS packaged under high ratio of CO2 (60%) along with argon and oxygen was the potential method for augmenting the shelf-life of ASBS for >15 days at 4 °C.

Moringa Oleifera Leaf Extract and Its Promising Synergistic Antimicrobial Effect with Typhoid Fever Vaccine in Immunized Mice

Abstract Typhoid fever, a systemic infection caused by Salmonella typhi has maintained a high morbidity and mortality profile around the globe especially in developing countries. Though currently licensed vaccines are efficacious in prevention of the infection, their potency is ephemeral; hence, they require a boost by employing adjuvants that are safe and instrumental in achieving a better prolonged protective immune defense outfit. In this work, Moringa oleifera ethyl acetate leaf extract was evaluated for its possible adjuvant property to a heat-killed ST vaccine. Mice were vaccinated with typhoid vaccine and subsequently, daily weight of mice was measured. Also, post-vaccination microbial colony counts were enumerated after challenging the mice with Salmonella typhi cells. From the blood culture results, MO extract demonstrated an excellent synergistic antimicrobial effect as the mice group administered our formulated vaccine-MO extract combination had the lowest microbial load (12.25 ± 4.86) colony forming units following microbial challenge, when compared to the mice groups administered the vaccine alone (37.25 ± 4.5) and the MO extract alone (31.25 ± 9.43). Furthermore, assessment of the mice body weight of treated groups showed a growth pattern that did not deviate significantly from those of the control group. In conclusion, MO extract demonstrated a promising synergistic antimicrobial effect on coadministration with the typhoid fever vaccine against S. typhi and did not lead to adverse side effects in mice.