Reduction In Microbial Counts Research Articles

Investigation of the impact of cold plasma pretreatments, long term storage and drying on physicochemical properties, bioactive contents and microbial quality of 'Keitt' mango

There is heightened demand for dried mango fruits with desired nutritional and physicochemical qualities, microbiologically stable and chemical residue free. This has led to the exploration of innovative preservation technologies for the extension of storability prior to processing. This study investigated the impact of cold plasma (CP) treatment on physicochemical properties and microbial stability in fresh and dried 'Keitt' mango during long term storage. Freshly harvested 'Keitt' mangoes were subjected to: CP treatment (for 5 min (CP5) and 10 min, CP10), dipping in “Chronos Prochloraz” for 30 s (industry practice), and untreated group (control). All samples were stored at 11°C for 30 days, prior to minimal processing and hot air drying at 60°C. Results after 30 days of storage demonstrated that untreated samples (control) had the highest TSS (15.06 ± 0.32 °Brix), while CP10 pretreated samples had the lowest TSS (13.80 ± 0.06 °Brix) value (p ≤ 0.05). In comparison to the fresh samples post storage, all pretreated dried mango slices retained lower total flavanols with CP5 (13.49 ± 1.64 mg GAE 100/g), CP10 (20.12 ± 1.42 mg GAE 100/g) and SMB (23.89 ± 3.35 mg GAE 100/g), but higher than the dried untreated samples (6.68 ± 0.53 mg GAE 100/g). Yellowness (b*) of the fresh pulp (38.53 ± 1.73) increased significantly (p ≤ 0.05) with the long-term storage (39.88 – 46.74) and drying (55.01 – 64.90). CP pre-treatment combined with drying resulted in ≥ 2 Log reduction in microbial count. This study shows the potential of cold plasma as a pretreatment for extending storability and maintaining the quality of 'Keitt' mangoes.

Depuration of Asian Green Mussels Using Chitooligosaccharide-Epigallocatechin Gallate Conjugate: Shelf-Life Extension, Microbial Diversity, and Quality Changes during Refrigerated Storage

The effect of chitooligosaccharide-EGCG conjugate (CEC) at different concentrations (0, 1, and 2%; w/v) and depuration times (DT; 3, and 6 h) on the total viable count and Vibrio spp. count of Asian green mussels (AGMs) was studied. Depurated samples showed a reduction in both microbial counts as compared to fresh AGMs (without depuration) and AGMs depurated using water (CON). A similar TVC was noticed at both DTs; however, a lower VC was attained at a DT of 3, irrespective of CEC concentrations (p < 0.05). AGMs were depurated for 3 h using 1 and 2% CEC (CE1 and CE2, respectively) solutions and stored for 6 days at 4 °C. The CE2 sample showed the lowest microbial counts as compared to fresh AGMs, CON, and CE1 throughout the storage (p < 0.05). CE2 extended the shelf-life of AGMs by 4 days, which was also supported by the lower peroxide value (0.48 mg cumene hydroperoxide/kg sample) and TBARS (0.94 mmol MDA eqv/kg sample) when compared with other samples. Moreover, CE2 had a lower total volatile nitrogen base (TVB; 4.72 mg N/100 g) and trimethylamine (TMA; 3.59 mg N/100 g) on day 4. Furthermore, 2% CEC was able to maintain the DHA content; however, a slightly lower EPA was noticed as compared to the CON. Next-generation sequencing suggested that the CON had a larger microbial community, especially Vibrio sp., than the CE2. All the treated samples showed similar likeness scores to the cooked CE2 and CON on day 0. However, slightly lower likeness was attained when CE2 was stored for 4 days, but the likeness score was higher than the acceptable limit (5). No difference in cooking loss was noticed between CON and CE2 samples on day 0. Nevertheless, cooking loss was increased on day 4. Thus, depuration using CEC solution enhanced the shelf-life of AGMs by 4 days without having negative impact on consumer acceptability and textural properties.

Photodynamic coatings kill bacteria on near-patient surfaces in intensive care units with low light intensities

Surfaces in close proximity to patients within hospitals may cause healthcare-associated infections. These surfaces are repositories for pathogens facilitating their transmission among staff and patients. Regular cleaning and disinfection of these surfaces provides only a temporary elimination of pathogens with inevitable recontamination. Antimicrobial coatings (AMCs) of such surfaces may additionally reduce the risk of pathogen transmissions. To evaluate the efficacy of a standard and a novel photodynamic AMC, even at very low light intensities, in a field study conducted in two ICUs at our university hospital. The microbial burden was determined on three coatings: standard photodynamic AMC (A), a novel photodynamic AMC (B), and an inactive AMC as control (C). The control coating C was identical to standard coating A, but it contained no photosensitizer. During a three-month period, 699 samples were collected from identical surfaces using eSwab and were analysed (cfu/cm2). Mean values of all surfaces covered with control coating (C) showed a microbial burden of 5.5 ± 14.8cfu/cm2. Photodynamic AMC showed significantly lower mean value of 1.6 ± 4.6cfu/cm2 (coating A; P < 0.001) and 2.7 ± 9.6 (coating B; P < 0.001). When considering a benchmark of 2.5cfu/cm2, the relative risk for higher microbial counts was reduced by 52% (coating A) or 40% (coating B), respectively. Both photodynamic AMCs offer a substantial, permanent risk reduction of microbial counts on near-patient surfaces in ICUs with low light intensities.

Efficacy of Rose Bengal-Mediated Antimicrobial Photodynamic Therapy as an Adjunct to Scaling and Root Planing on Clinical and Microbiological Parameters in the Management of Chronic Periodontitis: A Single-Blinded, Randomized Controlled Clinical Trial.

Aim: The study aims to assess the efficacy of rose bengal (RB)-mediated antimicrobial photodynamic therapy (a-PDT) as an adjunct to scaling and root planing in the management of chronic periodontitis patients in terms of clinical parameters like gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), and microbiological parameters like total microbial count, total red complex organism count, Porphyromonas gingivalis count, Treponema denticola count, and Tannerella forsythia count. Materials and Methods: In this randomized controlled clinical trial, a total of 30 patients were recruited who met the inclusion criteria. The participants were randomly allocated into group A with scaling and root planning (SRP) alone and group B with SRP + a-PDT. The clinical and microbiological parameters were measured at baseline and at 3-month follow-up. Intergroup and intragroup comparisons were performed using independent t test and paired t test, respectively. Value of p < 0.05 was considered as statistically significant. Results: At 3-month follow-up, group B treated with SRP + a-PDT showed statistically significant reduction in GI (0.58 ± 0.20) and PPD (1.81 ± 0.32 mm), gain in CAL (0.73 ± 0.04 mm), and reduction in total microbial count [2.80 ± 0.08 × 104 colony forming unit (CFU)], total red complex count (0.29 ± 0.14 × 102 CFU), P. gingivalis count (0.43 ± 0.13 × 102 CFU), T. denticola count (0.61 ± 0.04 × 102 CFU), and T. forsythia count (0.59 ± 0.04 × 102 CFU) as compared with group A (p < 0.05). Conclusion: RB-mediated a-PDT as an adjunct to SRP was significantly more effective in improving GI, PPD, and CAL and in reducing microbial count as compared with SRP alone in the management of chronic periodontitis.

Slaughtering processes impact microbial communities and antimicrobial resistance genes of pig carcasses

Several steps in the abattoir can influence the presence of microbes and associated resistance genes (ARGs) on the animal carcasses used for further meat processing. We investigated how these processes influence the resistome-microbiome of groups of pigs with different on-farm antimicrobial exposure status, from the moment they entered the abattoir until the end of carcass processing. Using a targeted enrichment metagenomic approach, we identified 672 unique ARGs conferring resistance to 43 distinct AMR classes from pooled skin (N = 42) and carcass swabs (N = 63) collected sequentially before, during, and after the slaughter process and food safety interventions. We observed significant variations in the resistome and microbial profiles of pigs before and after slaughter, as well as a significant decline in ARG counts, diversity, and microbial DNA load during slaughter and carcass processing, irrespective of prior antimicrobial treatments on the farm. These results suggest that existing interventions in the abattoir are effective in reducing not only the pathogen load but also the overall bacterial burden, including ARGs on pork carcasses. Concomitant with reductions in microbial and ARG counts, we observed an increase in the relative abundance of non-drug-specific ARGs, such as those conferring resistance to metals and biocides, and in particular mercury. Using a strict colocalization procedure, we found that most mercury ARGs were associated with genomes from the Pseudomonadaceae and Enterobacteriaceae families. Collectively, these findings demonstrate that slaughter and processing practices within the abattoir can shape the microbial and ARG profiles of pork carcasses during the transition from living muscle to meat.

The Impact of Pulsed Electric Field Technology on Enzymes, Microbial and Nutritional Quality in Milk Processing - A Comprehensive Review

A pulsed electric field is a non-thermal technology used in the processing of foods, especially liquid foods such as milk, fruit juices, etc. The objective of this review is to provide an understanding of pulsed electric field technology and its application in milk processing, particularly in whole milk, skim milk, and UHT milk. This technology can be used as an alternative to traditional heat treatments such as pasteurizing, hot filling, blanching, and sterilization. In this technology, short high-intensity electric field is used at moderate temperatures. A pulsed electric field is an effective technology to inactivate microorganisms and enzymes with minimum changes in nutritional, functional, and organoleptic qualities compared to heat treatments. Pathogenic and spoilage bacteria can be reduced effectively when using pulsed electric field technology. However, there are variations between studies. As a recent advance, the pulsed electric field is used with mild heating. This shows a significant reduction in microbial count with less detrimental effects on the physico-chemical and organoleptic properties of food. It also has minimal impact on nutrients present in the milk such as proteins, milk fat globules, and vitamins. In this review, we describe in detail the introduction, the principle of pulsed electric field, the impact of pulsed electric field on microorganisms, enzymes, and nutrients, and the advantages and disadvantages of using PEF technology. Further studies can be conducted to investigate the combined approach of the pulsed electric field with mild heating treatment methods including pasteurization and sterilization.

Evaluation of the effect of active essential oil components added to pickled-based marinade on beef stored under vacuum packaging: Insight into physicochemical and microbiological quality

This research aimed to evaluate the effects of the addition of active essential oil components (linalool and/or eugenol) to a pickle-based marinade on controlling spoilage and extending the shelf life of fresh beef stored under vacuum packaging at 4 °C. Linalool and eugenol were used either separately at a concentration of 0.2 % (w/w) or together (1:1 ratio) to preserve marinated beef under vacuum packaging for 15 days. Samples were assessed for pH, color, texture, oxidative degradation, and microbiological parameters. All marinades exhibited significantly lower TBARS values than the control sample. The addition of linalool or eugenol to the marinate showed a significant antibacterial effect on total aerobic mesophilic bacteria (TAMB), lactic acid bacteria (LAB), Pseudomonas spp., and total coliform, and the reductions in microbial counts are as follows: TAMB: 1.563 log CFU/g and 1.46 log CFU/g; Pseudomonas spp.: 1.303 log CFU/g and 1.08 log CFU/g; LAB: 0.323 log CFU/g and 0.357 log CFU/g. Marinated beef with linalool and/or eugenol was found to be effective against the growth of yeast and mold. The use of eugenol presented the most effective inhibition activity against yeast and mold by reducing the number of yeast and molds to an uncountable level on the 12th and 15th days of storage. Physicochemical analysis also showed that the addition of active essential oils to marinade did not cause any undesirable effects on the color and texture properties of beef samples. Therefore, the findings revealed that eugenol and linalool could be suitable alternatives for beef marination.

Combined hurdle effects of pulsed electric field and ultraviolet-C irradiation on microbial load reduction and composition of hemeproteins from Asian seabass gills

The combined effects of two non-thermal technologies, namely pulsed electric field (PEF) and ultraviolet-C (UV–C) irradiation, on microbial load reduction and composition of crude hemeprotein extract (CHPE) from Asian seabass gills were investigated. PEF at two intensities (15 kV and 17.5 kV) for different times (0, 1, 2.5, 5 and 10 min) was employed to treat CHPE solution. Subsequently freeze-dried PEF treated powders were exposed to UV-C for varying durations (0, 15 and 30 min). Microbial community in gill and selected CHPE powders was also determined using next generation sequencing (NGS). PEF treatment effectively reduced the initial microbial load (8.0 log10 CFU/g) when high PEF intensity (17.5 kV) for longer treatment time (5 min) was employed, leading to microbial load reduction to 5.5 log10 CFU/g. However, prolonged PEF treatment adversely affected CHPE properties, as witnessed by the decreased heme iron content and alterations in protein patterns. Subsequent UV-C irradiation of freeze-dried PEF-treated CHPE powder for 15 min demonstrated a synergistic effect on further reduction of microbial counts to 3.0 log10 CFU/g. NGS analysis showed the dominance of Flavobacteriaceae families in the microbial community composition in gill, untreated CHPE powder and PEF-UV-C treated CHPE powder. Nevertheless, no Vibrio parahaemolyticus and other Vibrio spp. were detected in all samples. The study revealed the potential of combined non-thermal hurdle technologies, under appropriate conditions, in ensuring microbiological safety and maintaining quality of CHPE. CHPE powder could therefore be used for fortification in food products as an iron supplement to alleviate iron-deficient anemia.

Don't Rush with Your Brush: An In Vitro Study on Toothbrush Hygiene.

To evaluate the effectiveness of audiovisual (AV) aids in creating awareness of toothbrush hygiene. This randomized trial study was conducted on 40 children aged 6-11 years. Children were given soft toothbrushes and then collected after brushing for 14 days. The toothbrushes were collected and sent to the laboratory for microbial culture evaluation. A questionnaire consisting of various questions regarding daily toothbrush hygiene practices was filled by the parents at the same time. After 14 days, brushes were collected, and the parents were shown an AV aid regarding toothbrush decontamination, parental awareness, and supervision. Those children were given new sets of toothbrushes and instructed to decontaminate them with chlorhexidine solution. After 14 days, the same questionnaire was filled out by the parents and toothbrushes were collected and immediately sent to the laboratory for microbial culture evaluation. All the sampled toothbrushes had significant (p < 0.001) bacterial growth after 14 days of use. The use of disinfectant led to a 99.98% reduction in microbial colony counts. Hence, showed a significant result. Questionnaire analysis showed a positive parental approach toward maintaining toothbrush hygiene. Cleaning and disinfection of toothbrushes is crucial to stop the spread of disease since bacterial contamination cannot be 100% eliminated. AV aids can be effective tools for increasing awareness. Through this study, we want to emphasize toothbrush hygiene and create awareness for the same through AV aid because a healthy toothbrush leads to healthy oral health. Sharma S, Tandon S, Rai TS, et al. Don't Rush with Your Brush: An In Vitro Study on Toothbrush Hygiene. Int J Clin Pediatr Dent 2024;17(2):162-167.

A microbial assessment of instrumentation and noninstrumentation laser disinfection technique: An in vivo study

ABSTRACT Introduction: The present study compares the reduction in microbial count of instrumentation versus noninstrumentation laser disinfection technique. Methods: Thirty patients with periapical lesions ranging 3–5 mm in single-rooted teeth were selected for the study. The groups were divided into two main groups: Group 1 – instrumentation technique and Group 2 – noninstrumentation technique subjected to laser disinfection. Group 2 was again subdivided into two groups: Group 2A – only laser disinfection and Group 2B – laser disinfection and medicament. The groups were analyzed for the reduction in microbial count. The Kruskal-Wallis test was used to compare mean differences in colony-forming unit (CFU) counts. Post operative mean CFU between the three groups were compared using Dunn’s Post Hoc analysis. The level of significance was set at P &lt; 0.05. Results: Significant differences were noted in mean CFU counts between Group 1 and Groups 2A and 2B (P = 0.006 and P = 0.001, respectively). Among Groups 2A and 2B, the reduction in the microbial count of Group 2B is better than 2A although not significant. Discussion: The use of Er:YAG laser allows for effective use in disinfection due to its favorable properties such as antimicrobial effect, photoacoustic streaming, vapor bubbles effect, and lack of negative thermal impact on the periodontium. Conclusion: Significant shifts were observed in both the groups, but the impact of the shift was greater in the laser-assisted groups. Noninstrumentation laser disinfection technique shows promising results when compared to conventional techniques.

Photodynamic Inactivation of microorganisms for agricultural applications

SignificancePlant pathogens cause severe harvest losses and bacterial food contaminations kill people worldwide. Photodynamic Inactivation (PDI) might be applicable to control pathogens in agriculture. ApproachWe here test PDI based on Sodium Magnesium Chlorophyllin and LED light or sunlight activation against relevant bacterial and fungal plant pathogens as well as Listeria on seeds and sprouts. ResultsPhotodynamic Inactivation is highly effective against Gram+ and Gram- bacterial plant pathogens in suspension and in situ on leaves with a reduction of microbial count for up to seven log steps. Seeds can be effectively decontaminated from Listeria innocua by PDI, and the effect is propagated to sprouts. ConclusionsIf based on natural photosensitizers such as Sodium Magnesium Chlorophyllin, PDI, might allow for effective, ecofriendly and economic control of plant pathogens and microbial contaminations of seeds as food.

Effects of Thermosonication on the Antioxidant Capacity and Physicochemical, Bioactive, Microbiological, and Sensory Qualities of Blackcurrant Juice.

This study investigated the effects of thermosonication (TS) on the quality of blackcurrant juice, along with its physicochemical properties, bioactive compounds, antioxidant capacity, and microbiological and sensory qualities. The treatments included raw juice (RJ), pasteurized juice (90 °C, 1 min, PJ), and thermosonicated juice (480 W, 40 kHz at 40, 50, or 60 °C, for 10, 20, 30, or 40 min, TJ). The results indicated that the effects of pasteurization and thermosonication on the pH, total soluble solids, and titratable acidity of the juice were not significant (p > 0.05). However, the cloudiness, browning index, and viscosity were significantly increased (p < 0.05), and the color properties of the blackcurrant juice were improved. The total phenolic, flavonoid, and anthocyanin contents of TJ (treated at 50 °C for 30 min) were increased by 12.6%, 20.9%, and 40.4%, respectively, and there was a notable decline in ascorbic acid content after the pasteurization treatment, while the loss was minor in all TJ samples compared with RJ. The scavenging ability of 1,1-diphenyl-2-pyridyl and hydroxyl radicals increased to 52.77% and 50.52%, respectively, which were significantly (p < 0.05) higher than those in the RJ and PJ samples. In addition, both pasteurization and thermosonication resulted in a significant (p < 0.05) reduction in microbial counts, while there were no significant (p > 0.05) differences in the sensory parameters compared with the RJ samples. In conclusion, this study suggests that TS is an effective method that can be used as an alternative to pasteurization to improve the quality of blackcurrant juice.

Effects of low-sodium bread on dietary compliance and fecal cultivable bacteria in a randomized controlled pilot trial in hypertensive subjects

High salt intake and compliance to low-sodium (LS) diets are critical in hypertension. Salt reduction in processed foods can help to achieve the target sodium intake. To verify the hypothesis that an innovative LS formulation of a traditional bread could result in a reduction of sodium intake and blood pressure, we performed a 6-month randomized controlled pilot trial on hypertensive patients. We additionally explored the effects of sodium restriction on blood pressure and fecal cultivable bacteria.Fifty-seven patients were randomized in three groups. Group A (n = 19) followed a free diet using standard bread (750 mg Na/100 g), group B (n = 18) followed a LS diet (2300 mg Na/die) using standard bread, group C (n = 20) followed a LS diet (2300 mg Na/die) using LS bread (280 mg Na/100 g). We measured 24-h urinary sodium, blood pressure, routine parameters, fecal microbial counts (26 patients).After 6 months, as compared to group A, group C showed a reduction of 24-h urinary sodium excretion (-908 mg/24 h), diastolic pressure (-9 mmHg) and microbial counts of Bacteroides, Porphyromonas, Prevotella, Enterobacteriaceae, Staphylococcus, Micrococcus. These results suggest that LS bread could increase the adherence to a LS diet, reducing sodium excretion, diastolic pressure and abundance of some fecal cultivable bacteria.Trial registration Registration nr. NCT03127553, on 25/04/2017.

Fabrication, characterization, and application of pea protein-based edible film enhanced by oregano essential oil (OEO) micro- or nano-emulsion

Pea protein isolate (PPI)-based active films were prepared by incorporating 0.5 %, 1.0 %, or 2.0 % of oregano essential oil (OEO), either in the form of micro-emulsion (MOEO) or nano-emulsion (NOEO). The particle size and polydispersity index of OEO droplets were 2755.00 nm and 0.63 for MOEO, and 256.30 nm and 0.20 for NOEO. The surface and cross-sectional SEM results revealed the presence of holes and internal pores within the film upon the addition of OEO. The molecular interaction between PPI and OEO was confirmed by FTIR. The addition of OEO significantly increased film thickness, decreased water contact angle, and imparted a more yellow color. At a low concentration (0.5 %), the addition of OEO significantly improved the water vapor barrier and mechanical properties of the film. However, at higher concentrations, these film properties were significantly weakened. Additionally, the film antimicrobial properties were assessed after OEO addition. In vitro inhibition zone results indicated that a 2.0 % addition of OEO significantly suppressed the growth of three Salmonella strains [Salmonella Typhimurium (ATCC14028), Salmonella Infantis 94-1, and Salmonella Enteritidis PT-30]. Application of pea protein-based film with 2.0 % OEO on chicken breast demonstrated significant reduction in microbial count. Our results further showed that reducing the particle size of OEO from micrometer-scale to nanometer-scale in the PPI film matrix did not significantly alter film properties or antimicrobial activities. The study demonstrated that the antibacterial film based on pea protein and OEO is an innovative food packing material for prohibiting bacteria growth on poultry products.

Influence of Passive Ultrasonic Irrigation of the Photosensitizer Used in Photodynamic Therapy on Microbial Reduction in the Root Canal System: An in Vitro Study.

The success of endodontic treatment is based on microbial reduction promoted by the interaction of chemical and mechanical procedures. Photodynamic therapy (PDT) is used as an adjunct to conventional treatment, with significant microbial reduction. This study aimed to evaluate the influence of passive ultrasonic irrigation (PUI) of the photosensitizer (PS) used in PDT on microbial reduction in the root canal system. Forty-five mesiobuccal root canals from extracted human mandibular molars that were inoculated with standard strains of Enterococcus faecalis, Candida albicans, and Streptococcus mutans for 21 days were selected. The root canals were prepared using the ProTaper Next system and randomly divided into 3 groups (n=15): 1) PDT: PDT alone; 2) PUI+PDT: PUI followed by PDT; and 3) PUI/PS+PDT: PUI of the PS followed by PDT. Microbiological samples were collected from the canals before and after using the protocols described above. The data were analyzed by analysis of variance (Tukey's test) at a significance level of 5%. Microbial counts before PDT, PUI+PDT, and PUI/PS+PDT did not differ significantly (P>0.05), showing methodological standardization in the microbial contamination of the root canal system. There was a significant reduction in microbial counts after PDT (61.05%), PUI+PDT (65.04%), and PUI/PS+PDT (68.58%) (P<0.01), but with no statistically significant difference between the three groups (P>0.05). Based on the present findings, it was concluded that the combination of PUI with PDT or PS activation did not influence microbial reduction achieved by PDT alone.

Herbal oral care products for the prevention of ventilator-associated pneumonia: A systematic review and network meta-analysis of randomised trials.

The recommendation for Chlorhexidine (CHX) as a traditional oral care solution is decreasing, and herbal oral care products are being considered as a potential alternative. This network meta-analysis aims to determine if herbal oral care products for oral care in mechanically ventilated patients are superior to CHX and provide direction for future research by comparing the effectiveness of herbal oral care products currently available. We searched for English-language published and grey literature sources of randomized clinical trials involving herbal oral care solutions in intensive care unit (ICU) oral care (until September 2023). The primary outcome was the incidence of ventilator-associated pneumonia (VAP); the secondary outcome was the oral microbiota quantity. Data were pooled by pairwise meta-analysis and Bayesian network meta-analysis. The risk of bias was assessed using the Cochrane risk of bias tool, and the certainty of evidence was evaluated using the GRADE framework. Our network meta-analysis included 29 studies, and the results showed that Chinese herb (OR: 0.39, 95% CI: 0.2-0.75) and Miswak (OR: 0.27, 95% CI: 0.07-0.91) were more effective in reducing VAP incidence than CHX. In terms of reducing bacterial counts, Chinese herb (OR: 0.3, 95% CI: 0.19-0.48) was superior to CHX, and all herbal oral care products, including Persica® (alcoholic extract of S. persica, Achillea millefolium, and Mentha spicata), Matrica® (Chamomile extract), and Listerine® (main components include Menthol, Thymol, and Eucalyptol), were better than saline in all aspects but without significant differences. Based on our network meta-analysis, we have observed that Chinese herbal medicine and Miswak are superior to CHX in reducing the incidence of VAP. However, the safety and feasibility of traditional Chinese herbal medicine require further high-quality research for validation. Simultaneously, Matrica® demonstrates a significant reduction in microbial counts but does not exhibit a significant advantage in lowering the incidence of VAP. This observation aligns with the results of clinical double-blind trials. Therefore, we identify Miswak and Matrica® as promising herbal oral care products with the potential to replace CHX. It is essential to emphasize that our study provides guidance for future research rather than conclusive determinations. PROSPERO no. CRD42023398022.

Antibacterial Efficacy of Essential Oils from Four Spices against Salmonella typhimurium: Mathematical Modelling and Application in Enhancing Salad Cream Safety

The study was conducted to investigate the inhibitory effects of certain natural substances (finger root, clove, lemongrass, cardamom, and the combination of lemongrass with cardamom) against Salmonella typhimurium, a type of bacteria known to cause foodborne illnesses. The result showed that finger root, clove, lemongrass, cardamom, and the combination of lemongrass with cardamom exhibited strong inhibitory effects against S. typhimurium. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were evaluated. MIC values ranged from 0.049 to 0.781 µl/ml, and MBC values ranged from 0.049 to 6.250 µl/ml. Furthermore, the study aimed to develop mathematical models that accurately describe S. typhimurium survival in the presence of these essential oils. By understanding how the S. typhimurium respond to the oils over time, it was found that the mathematical models accurately described bacterial survival, with the modified Gompertz model fitting for finger root essential oil and the Weibull and modified Gompertz models suitable for the other oils. Additionally, the study sought to evaluate the practical viability of incorporating these essential oils into salad cream formulations, primarily aiming to assess their potential in reducing S. typhimurium counts and ensuring compliance with established quality standards. Specifically, the inclusion of finger root, clove, lemongrass, cardamom, and the combination of lemongrass with cardamom in salad cream formulations, maintained at a controlled temperature of 4 °C, yielded positive outcomes, meeting the required quality standards. Importantly, the presence of S. typhimurium was rendered undetectable, and an overall reduction in microbial count was observed when compared to cream formulations lacking these essential oils. This study effectively underscores the potential of the examined essential oils as natural antimicrobial agents suitable for incorporation in food products

A Quality Assessment of Strawberry Nectar Stabilized by Thermal and High-Pressure Processing Conditions

This study is aimed at evaluating the quality of strawberry nectar following high-pressure processing (HPP) at different pressure levels (400, 500, and 600 MPa for 3 minutes) and thermal pasteurization (TT) at 75°C for 15 s. Key parameters include total colour difference ( Δ E ∗ ), aparent viscosity, colour analysis via CIELAB coordinates, and pH. Additionally, residual enzymatic activity (RA%) of polyphenol oxidase (PPO) and peroxidase (POD) was measured. Strawberry nectar (12°Brix) was prepared and subjected to processing, with thermal treatment in 50 mL tubes and HPP in 40 mL polyethylene bags. Samples were stored under refrigeration during 21 days, with microbial analysis conducted to assess microbiological stability during storage. TT exhibited a more pronounced reduction in total aerobic microbial count (TAMC) compared to HPP, which showed no detectable yeast and mould. Apparent viscosity varied among samples, with HPP at 600 MPa displaying a significant increase of 52.1% compared to the control. The pseudoplastic behavior, characterized by n values lower than 1, was consistent across all treatments. TT led to a reduction in L ∗ brightness value during storage, whereas HPP-treated samples underwent colour changes over time with Δ E ∗ of 3.1 for 400 MPa, 3 minutes, at 21 days. For PPO and POD, the 600 MPa treatment exhibited the highest inhibition (44% and 4% RA, respectively). This comprehensive study provides insights into how different HPP processing conditions affect the quality attributes, enzymatic activity, and microbiological stability of strawberry nectar during production and refrigerated storage. The research’s significance lies in its holistic comparison of HPP with traditional thermal pasteurization, offering valuable information for both industry and consumers.

Diode laser targeting red-complex bacteria in periodontitis: a systematic review.

This systematic review examines the effectiveness of diode laser irradiation in reducing the levels of red complex bacteria as well as periodontal parameters of pocket depth and clinical attachment level. We conducted electronic searches across databases such as Scopus, Embase, Medline, and Web of Science databases in July 2022. Randomized controlled trials that evaluated the reduction of red-complex bacteria in patients with periodontitis using diode lasers were included. The primary focus was the reduction in the microbial count of red complex bacteria, whereas probing depth and attachment level were considered secondary outcomes. Articles in languages other than English were excluded. Study quality was assessed based on the Cochrane Handbook for Systematic Reviews of Interventions and the ROB2 tool. After searching the databases, eight independent studies were included, with a sample size of 210 subjects. The average age group of the study population was 30-60 years, and there was a lack of consensus on the antimicrobial effect of diode lasers. Out of the eight studies, four studies reported no significant difference in the levels of red complex bacteria before and after laser application. Three studies reported significantly lower levels of red complex bacteria in the intergroup comparison. One study reported that laser had no significant effect on intergroup bacterial levels. The combination of diode laser irradiation with scaling reduced the count of red complex bacteria and improved the clinical parameters, although not significantly. Based on the limited evidence available, the adjunctive use of diode laser for scaling and root planning may provide some additional benefit in terms of reduction of red complex bacterial count and clinical parameters. Further well-designed trials and the use of objective measures are necessary before outlining universal guidelines for best practice. The adjunctive use of diode laser in non-surgical periodontal therapy may provide a reduction in the red complex microbial count and improvement in clinical parameters, decreasing the need for periodontal surgery.

Antibacterial properties of metal nanoparticles–incorporated activated carbon composites produced from waste biomass precursor

Activated carbon-based composite materials, together with the well known antibacterial activity of metal nanoparticles, urged the performance of this study to prepare new antibacterial materials with antimicrobial activity, as an important step in fighting pathogenic organisms. Activated carbon derived from a waste source - almond shells - were combined with metal (Ag, Cu, Mg) nanoparticles, in order to obtain metal composite with desirable characteristics. The composites were obtained using one-step high-temperature hydro-pyrolysis and further impregnation of the metal from water solution. Investigation of the structure, chemical composition and morphology of obtained composites was carried out by scanning electron microscopy, XRD, XPS, elemental and BET analysis, before testing their antimicrobial activity. Strongest antibacterial effect against E. coli was observed when 10 % Cu Activated Carbon Composite (ACCCu) was used attaining 100 % reduction of microbial count even at the starting point. ACCAg, ACCMg and activated carbon only, demonstrated such effect after 24 h. Best results after treatment of S. aureus were achieved with ACCAg and ACCCu after 24 h.The results indicate that the antibacterial activity depends on the contact time, bacterial species, nature of the metal and metal concentration. The novel metal nanoparticles-incorporated activated carbon composites demonstrated very good antibacterial activity. The investigation provides novel materials with antibacterial properties for further development and potential application in hygiene devices.