Anaerobic Bacterial Counts Research Articles

The effectiveness of glucosite gel in reducing bleeding on probing and anaerobic bacterial count pre and post intra-periodontal pocket application

The effectiveness of glucosite gel in reducing bleeding on probing and anaerobic bacterial count pre and post intra-periodontal pocket application

The efficacy of 2780 nm Er,Cr;YSGG and 940 nm Diode Laser in root canal disinfection: A randomized clinical trial

ObjectivesEffective disinfection of the root canals is the cornerstone of successful endodontic treatment. Diminishing the microbial load within the root canal system is crucial for healing in endodontically treated teeth. The aim of this study was to evaluate the effect of 2780 nm Er,Cr:YSGG and 940 nm diode lasers on the eradication of microorganisms from single-rooted teeth with asymptomatic apical periodontitis.Materials and MethodsThirty participants conforming to the inclusion criteria were randomly divided into 3 groups according to the disinfection protocol used; Conventional group: 2.5% Sodium Hypochlorite (NaOCl) and 17% EDTA solution NaOCl/EDTA, Dual laser group: 2780 nm Erbium, chromium: yttrium scandium-gallium-garnet (Er,Cr:YSGG) laser and 940 nm diode laser Er,CrYSGG/Diode, and Combined group: 17% EDTA and 940 nm diode laser EDTA/Diode. Bacterial samples were collected before and after intervention. The collected data were statistically analyzed using Friedman’s test and Kruskal–Wallis test (P ≤ 0.05).ResultsThe results of the study showed that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups showed significantly less mean Log10 CFU/ml of aerobic and anaerobic bacterial counts than the conventional NaOCl/EDTA group.ConclusionsIn this study we evaluated in vivo the bactericidal efficacy of three disinfection protocols for endodontic treatment of single-rooted teeth with apical periodontitis. The results indicated that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups provide superior bactericidal effect compared to the conventional NaOCl/EDTA group.Clinical relevanceThe integration of lasers into root canal disinfection protocols has demonstrated significant bacterial reduction which might promote healing and long-term success.

Viability of Anaerobic Bacteria in Dental Sub-Gingival Calculus and Its Minerlization – An Observational Microbiological Study

Background: Dental calculus, a mineralized product of plaque, remains ignored and is considered as a fossilized remnant of minor significance. Dental plaque is still considered as the main culprit in etiopathogenesis of periodontal disease. Several studies suggest that calculus has a porous and spongy nature because of which it may act as a reservoir for endotoxins and bacterial antibodies. However, the viability of bacteria in sub gingival calculus and its role in the pathogenesis and disease progression still remains a mystery. The present study aims to investigate the viability of bacteria within sub-gingival calculus and to assess the degree of mineralization of dental calculus and the variation of viable micro flora corresponding to the extent of mineralization. Materials and Methods: Eighteen samples of sub gingival calculus were harvested from patients with chronic inflammatory periodontal disease. The samples were divided into two groups, Group 1 (non-irradiated) and Group 2 (samples exposed to UV radiation) and Group 3 (samples assessed for mineralization). Group 1 and 2 samples were utilized for anaerobic culture to detect the presence of anaerobic bacteria. Group 3 samples were crushed in a Universal testing machine and mineralization was assessed according to the force required for crushing. Results: All study specimens showed positive bacterial growth under anaerobic conditions. The bacterial cultures revealed decrease in the bacterial count in Group 2 i.e. Irradiated group (I) when compared with Group 1 i.e. Non-irradiated group (NI). The results obtained from computerized Universal Testing Machine showcased varying values required to crush the sub-gingival calculus samples suggesting variation in mineralization of each sample. The correlation between mineralization and viable anaerobic bacterial count revealed an inverse relation. Conclusion: Sub-gingival calculus plays a key role in harbouring pathogenic anaerobic bacteria, owing to its porous ....

Chemical and Microbiological Spoilage of Canned Meat Products

Canned meats are a popular food source that provides protein and the advantage of extended shelf life. However, these products are carbohydrates, fats, vitamins to chemical and microbiological spoilage that can cause changes in their texture, flavor, and odor. Therefore, 60 random samples of locally manufactured canned food were collected from different supermarkets in Alexandria governorate, which were divided into three groups 20 each of canned beef, canned chicken, and canned fish. The obtained results revealed that the mean values of FFA, TVN, and TBA of canned beef, chicken, and fish were 1.17±0.08, 1.07±0.08 & 1.27±0.01; 0.12±0.05, 0.13±0.05 & 0.12±0.04 and 13.4±0.89, 12.75±0.44 & 14.52±0.73, respectively, while the mean of TMA in canned fish was 0.64±0.04 mg/100g. Regarding microbiological quality, the mean values of the aerobic bacterial count were 1.85×104±0.49×104, 1.1×104± 0.47×104, and 7.84×103±2.13×103 Cfu/g in examined canned beef, chicken, and fish products; the mean values of anaerobic bacterial count in the same products were 1.02×104±1.23×104, 0.52×104±0.70×104, and 6.0×103±9.01×103 Cfu/g, respectively. All chemical and bacteriological parameters compared with Egyptian and international standards. Bacillus cereus was detected in 25, 20 and 15% of examined canned beef, chicken, and fish products. On the other hand, Clostridium perfringens couldn’t be detected in any examined canned meat products. Contaminated canned meat products highlighted the need to implement food safety systems such as HACCP during the manufacturing of meat meals.

Impact of Probiotic Geotrichum candidum QAUGC01 on Health, Productivity, and Gut Microbial Diversity of Dairy Cattle.

Gut microbial diversity is a determinant of animal productivity and health. Probiotic supplementation in feed has been known to modulate the gut microbial diversity resulting in better feed utilization and resistance against diseases. The current study was designed to determine the probiotic potential of Geotrichum candidum QAUGC01 (VHDP00000000) in Sahiwal-Friesian crossbred dairy cows and its impact on gut microbial diversity, health, and productivity. To evaluate health and productivity, growth performance, determination of blood parameters, serum biochemistry, feed efficiency, milk yield & composition, and nutrients digestibility was determined and compared between control and experimental groups. Moreover, at the end of the experiment, the gut microbial diversity was evaluated through MiSeq (Illumina) sequencing of bacterial and fungal/yeast DNA in dung samples of both control and experimental cows. Inspite ofa significant reduction in dry matter intake the increase in feed efficiency and milk yield was observed in experimental cows with normal hematological and serum biochemical profile. The increase in anaerobic bacterialcount and decrease in the shredding of pathogenic flora was observed in experimental cows. Metagenomic analysis revealed Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes to be the four dominating phyla among bacteria and, Ascomycota followed by Basidiomycota and Neocallimastigomycota among the fungal population in both groups. The diversity of the core microbiome revealed high bacterial and Fungal Alpha diversity in the experimental group than in control via the Shannon index. This study provided insights into the safe use of G. candidum as a probiotic, to improve growth performance, health, productivity and gut microbial diversity of dairy cattle.

Effects of storage temperature on microbiota shifts in raw milk biofilm developed on stainless steel

This study aimed to investigate the microbiota in raw milk and the influence of storage temperature on the microbiota shift after biofilm formation. Raw milk stored at 4 °C and biofilms developed in raw milk incubated at 4 °C or 25 °C for 7 days were subjected to microbiota analysis as well as quantitative analyses of aerobic or anaerobic bacteria. The levels of aerobic bacteria increased during biofilm formation, while no significant changes were observed within anaerobic bacteria. In addition, there was a difference between aerobic and anaerobic bacterial counts in raw milk and biofilm stored for 7 days. The pattern of microbial composition differed by temperature. In addition, the genus Pseudomonas (53–71%) occupied a high proportion in raw milk, and the raw milk biofilm developed at 4 °C, while the genus Lactobacillus (75–83%) was predominant in biofilms developed at 25 °C. Intriguingly, bacterial richness was higher in raw milk on day 0 and biofilm developed at 4 °C than raw milk after 7 days of storage at 4 °C. These findings suggest that temperature critically affects the bacterial composition of both raw milk and its associated biofilm.

Application of the Hurdle Technology Concept to the Fresh Za'atar (Origanum syriacum) Preservation.

Oregano (Origanum syriacum) is popularly called za’atar in the Middle East region. It is widely used in the Mediterranean diet as an aromatic herb. This study aimed to evaluate the preservation effect of natural additives, vacuum packaging, and refrigeration on the quality traits of fresh oregano. In total, 132 fresh oregano samples were formulated and split into 4 groups (n = 33) labeled group A (100% fresh oregano leaves, Control), group B (fresh oregano 63.2%, 15% fresh onion, 20% oil, 1.8% salt), group C (fresh oregano 61.91%, 15% fresh Allium cepa, 20% oil, 1.8% salt, 1.29% sumac), and group D (fresh oregano 59.2%, 15% fresh Allium cepa, 20% corn oil, 1.8% salt, 4% lactic acid, ultimate pH 4.4). Different quality traits such as color index (L*a*b*), microbiological analysis (total aerobic, anaerobic, and psychrotrophic bacteria and yeasts and molds), and sensory features (taste, flavor, appearance, saltiness, and overall acceptance) were assessed during the storage period (42 days) for all groups. Our study showed that the addition of lactic acid (group D) exhibited a strong preservation effect against aerobic and anaerobic bacteria. In this context, group D had significantly lower aerobic and anaerobic bacterial counts (5.12 vs. 6.7, 6, and 6.7 log (cfu/g); p < 0.05) and (4.75 vs. 6.6, 6.1, 6.77 (cfu/g); p < 0.05) than group A, B, and C; respectively. Group D exhibited significantly (p < 0.05) lower psychrotrophic bacterial count (3.6 log (cfu/g)) during the whole period of storage compared with control. Group B had a lower redness index (a*) (−3.3 vs. −1.8, −1.65, −1.23; p < 0.05) than groups A, C, and D; respectively. In conclusion, our study showed that there is a possibility of improving the preservation of oregano (Origanum syriacum) by using lactic acid and sumac combined with vacuum packaging under refrigeration conditions.

Efficacy of Er:YAG laser for the peri-implantitis treatment and microbiological changes: a randomized controlled trial.

The aims of this study were to identify the microbiological changes in the periodontal pockets following an Er:YAG laser (ERL) irradiation and mechanical debridement to compare the effectiveness of ERL irradiation to mechanical debridement for peri-implantitis treatment through randomized controlled trials. Twenty-three patients with peri-implantitis lesions were treated in either a test group, ERL set at energy level of 100mJ/pulse, frequency of 10Hz, pulse duration was 100µs, and irradiated by three passages, or a control group, with mechanical debridement using an ultrasonic scaler. An examiner measured the following clinical parameters at different stages (a baseline and at 3- and 6-month post-treatment): probing depth (PD), bleeding on probing (BOP), marginal bone loss (MBL), and anaerobic bacteria counts. Linear regression, with generalized estimation equations, was used to compare the clinical parameters and anaerobic bacterial counts at different stages and between groups. The anaerobic bacterial counts significantly decreased within the control group during the follow-ups. At the 6-month follow-up, both groups showed a significant reduction in PD (test group: mean difference of 0.84mm; control group: mean difference of 0.41mm), and the test group showed a significantly higher PD reduction on the buccal site (1.31mm) compared to that of the control group (0.25mm). Both ERL and mechanical debridement treatments led to significant improvements in PD. When mechanical debridement therapy was used, significant anaerobic bacterial count reductions were observed. Future treatment of peri-implantitis should involve a combination of both of these therapies.

A POSSIBLE ALTERNATIVE AND SAFE ADJUNCTIVE ROLE FORLOCALLY APPLIEDMANGIFERININ PERIODONTAL THERAPY A CLINICAL AND MICROBIOLOGICAL STUDY

Background:Periodontal health has great impact on overall oral conditions which reflects subjects health. With the radical change that happened to human diet in the past several decades specially the wide spread of finely processed diet over the raw complex diet, it led to increase in several health problems which among them is the periodontal diseases. The periodontal therapy had been relaying on oral hygiene where a lot of researches where implied on adjunctive products which it could promote tissue healing after scaling and root planning as the prim treatment for such conditions. Many of these products showed side effects on long term use. So, apparently the search of a safe product that fulfil this rule would be a wise choice. Aim: The present study was designed to investigate the clinical and microbiological effectiveness of subgingivally delivered mango extract loaded on oxidized paper points (OPP) as an adjunct to scaling and root planing (SRP) in the treatment of periodontitis. Patients and methods:Thirty subjects with periodontal pockets were selected. For each, one site was randomly assigned to receive SRP+mangiferin, SRP+chlorhexidine and a third site received SRP only. The evaluated clinical outcomes were plaque index, gingival index, sulcus bleeding index, and PPD at baseline, two weeks and one month. Microbial analysis was done to estimate the count of aerobic and anerobic counts and also to assess antimicrobial activities of mangiferin against Porphyromonasgingivalis and Prevotella intermedia as compared to well-known antibiotics. Results: There was an intra-group significant reduction in each of the all clinical indices after 2 and 4 weeks of treatment. There were significant differences in each of PI, GI, and SBI between the negative control group and each of the study and positive control groups. There were no significant differences in these indices between the test and positive control groups. PPD showed no significant inter-group differences at any time points. There was intra-group significant reduction in each of the aerobic and anaerobic bacterial counts. There were no significant inter-group differences in these bacterial counts. Comparison in the inhibition zone of mangiferin and chlorhexidine showed that there was a significant difference favoring the mangiferin against tested organisms. There were significant differences between mangiferin when its inhibition zone was compared to tested antibiotics. Conclusion:These results suggested that mangiferin could be used as a good adjuvant in periodontal therapy and this treatment might improve the clinical parameters and reduce the bacterial count as comparable to the gold standard chlorhexidine treatment.

Controlled Bio-Fermentation by Lactobacillus and Lactococcus Probiotics for Improving Quality and Safety of Fessiekh (Fermented Grey Mullet)

ABSTRACT In the current study, fessiekh was produced using various probiotics (Lacticaseibacillus casei, Lactobacillus helveticus, and Lactococcus lactis subspecies cremoris) to explore their effect on the quality attributes of fessiekh. Application of bio-fermentation for fessiekh production using probiotics improved the sensory quality attributes and increased the lactic acid bacteria population, with a significant decrease in yellowness (b*) value and anaerobic bacterial count compared to control. The addition of L. casei and L. helveticus during the fermentation of mullet led to a significant decrease in moisture, ash, salt contents, pH, thiobarbituric acid reactive substances, redness (a*) values, S. aureus and mold counts, while protein, fat content, and lightness (L*) value increased compared to L. cremoris and control groups. On the contrary, the redness (a*) value of fessiekh was enhanced more by the application of L. cremoris than Lactobacilli. It was obvious that each probiotic used in mullet fermentation has a special unique effect on fessiekh properties; therefore, the use of probiotics can be a promising procedure to control the fermentation process during fessiekh production and improve the safety and quality of the product.

Post-operative Pain and Antibacterial Efficacy of Silver Nanoparticles Formulations Intracanal Medication: A Randomized Controlled Clinical Study

AIM: To evaluate the effect of using combined calcium hydroxide/silver nanoparticles or silver nanoparticles (AgNPs) or calcium hydroxide (Ca(OH)2) individually as intracanal medications in reducing postoperative pain and intracanal bacterial count. MATERIALS AND METHODS: Thirty patients with necrotic mandibular anterior teeth were randomly divided into 3 groups; Ca(OH)2 + AgNPs or AgNPs gel (Intervention Groups) or Ca(OH)2 (Control Group). Patients received a standard 2-visit endodontic treatment and recorded their pain levels after 4, 24, 48, 72 and 96 hours following the first and second visit on a modified visual analogue scale (VAS). Intracanal bacterial counts were assessed using culturing before and after instrumentation and intracanal medication. Outcome data were statistically analyzed using Kruskal-Wallis and Fisher’s Exact tests to compare between the groups and Friedman’s test to assess the changes by time. RESULTS: At 24 hours interappointment the incidence of pain was statistically significant (P = .005) as well as at 48 hours (P = .001). There was a statistically significant difference between the mean percentage reduction of anaerobic bacterial counts in the three groups with the highest percentage in the Ca(OH)2 + AgNPs group at 98.9% followed by AgNPs group 98.5% and Ca(OH)2 at 85.3% (P &lt;0.001). CONCLUSIONS: Combined calcium hydroxide/silver nanoparticles reduced the intracanal bacterial counts significantly, but adversely affected the interappointment pain. Based on that finding, this combination should be tested in different concentrations with different ratios to reach the most effective combination that reduce pain with high antibacterial efficacy.

SHORT TERM EFFECTS OF PHOTODYNAMIC THERAPY ON CLINICAL, MICROBIAL AND BIOCHEMICAL PARAMETERS IN PATIENTS WITH CHRONIC PERIODONTITIS

Objectives: Photodynamic therapy applies to the elimination of target cells by reactive oxygen species using a photosensitizing agent and a sufcient wavelength of light. It is a new, non-invasive approach to preventing infection. It is now an upcoming alternative treatment modality for periodontitis patients as a supplement to traditional scaling and root planing. The objective of the present study was to assess and compare the effect of photodynamic therapy with conventional Scaling and Root planing in patients with chronic periodontitis. Methods: The study included a minimum of 5 non-smoking males with mild to moderate periodontitis. Clinical parameters such as plaque index, gingival index, gingival bleeding index, pocket probing depth, clinical attachment level; microbiological parameter – anaerobic bacterial CFU count in subgingival plaque samples and biochemical parameter – GCF SOD levels were evaluated at baseline and 28 days postoperatively. The obtained data were analyzed using SPSS (SYSTAT 12) statistical software. The Wilcoxon signed Rank test was used to compare the mean values of various parameters before and after treatment. Results: The results of the study show that all clinical parameters improved from baseline to day 28. Following therapy, the mean levels of the anaerobic bacterial CFU and GCF SOD have decreased dramatically. Conclusion: The results of this study suggest a signicant improvement in clinical, microbiological and Biochemical parameters with the use of PDT as an adjunct to conventional SRP in chronic periodontitis patients

Treatment with the Probiotic Product Aviguard® Alleviates Inflammatory Responses during Campylobacter jejuni-Induced Acute Enterocolitis in Mice.

Prevalences of Campylobacter (C.) jejuni infections are progressively rising globally. Given that probiotic feed additives, such as the commercial product Aviguard®, have been shown to be effective in reducing enteropathogens, such as Salmonella, in vertebrates, including livestock, we assessed potential anti-pathogenic and immune-modulatory properties of Aviguard® during acute C. jejuni-induced murine enterocolitis. Therefore, microbiota-depleted IL-10−/− mice were infected with C. jejuni strain 81-176 by gavage and orally treated with Aviguard® or placebo from day 2 to 4 post-infection. The applied probiotic bacteria could be rescued from the intestinal tract of treated mice, but with lower obligate anaerobic bacterial counts in C. jejuni-infected as compared to non-infected mice. Whereas comparable gastrointestinal pathogen loads could be detected in both groups until day 6 post-infection, Aviguard® treatment resulted in improved clinical outcome and attenuated apoptotic cell responses in infected large intestines during acute campylobacteriosis. Furthermore, less distinct pro-inflammatory immune responses could be observed not only in the intestinal tract, but also in extra-intestinal compartments on day 6 post-infection. In conclusion, we show here for the first time that Aviguard® exerts potent disease-alleviating effects in acute C. jejuni-induced murine enterocolitis and might be a promising probiotic treatment option for severe campylobacteriosis in humans.

Analyses of the Bacterial Contamination on Belgian Broiler Carcasses at Retail Level.

Broilers are not equally exposed to bacterial contamination during rearing and processing, resulting in areas with different bacterial communities on carcasses at retail. The determination of these communities is also affected by the examination methods applied. The present study aimed to assess the bacterial communities on neck, breast, and back skin on broiler carcasses at retail through classical International Organization of Standardization based isolation methods combined with identification by matrix-assisted laser desorption ionization time-of-flight mass spectrum (MALDI-TOF MS) and 16S amplicon sequencing. Twelve commercially and eight organically reared broilers slaughtered in four slaughterhouses were examined. Significantly higher anaerobic bacterial counts were observed on the neck skin than on the breast and back skin. By the combination of cultivation and amplicon sequencing, remarkable shifts in bacterial communities were determined on the breast and back skin, but not on the neck skin. Although the aerobic bacteria contamination levels were not different between the areas, different bacterial communities were observed. The impact of the slaughterhouse to the overall microbial composition was rather small. Organically reared broilers had unique bacterial communities. In conclusion, compared to the breast skin, the neck, and back skin had a larger potential for bacterial spoilage, in particular when anaerobic storage conditions are applied. The distribution of bacteria on the different areas could be related to the contamination during slaughter as well as the bird-rearing methods.

Activity pattern of bacteria in biodigester based on gas production and burning hour analyses

Pollution around the world continues to grow and hence there is a growing interest in devising efficient and cost effective waste management. Biogas technology has in recent times viewed as a very good source of sustainable waste management. The present study was undertaken to investigate the role of different types of mesophilic, thermophilic and anaerobic bacteria in the bio digester responsible for biogas production. The activity pattern of bacteria in the bio digester based on gas production and the burning hour analyses of the biogas were also estimated in the study. Six samples of slurry from two biodigesters; one installed at University livestock farm and other at buffalo farm in the College of Veterinary and Animal Sciences, Mannuthy were collected using a pump in to UV sterilised polythene bag and subjected to microbial analysis. The activity pattern of microorganisms in the biodigester at the buffalo farm was studied based on the gas production pattern (Sasse, 1988). When the mean total viable count were examined (Mortan, 2001) from top to bottom of biodigester it was observed that aerobic mesophilic counts decreased and anaerobic mesophilic counts increased towards bottom. While both aerobic and anaerobic thermophilic bacterial count increased towards the bottom of the biodigester. Methanogenic bacteria constituting the thermophilc organisms were found to be actively growing at the bottom of biodigester. The burning hour analysis of biogas from one of the biodigester (at the buffalo farm) was also carried out (Sasse, 1988). Burning hour analysis showed that a volume of 0.1074 m3 methane rich biogas could produce a blue flame for an hour. The study illustrates the importance of biogas technology, besides supplying energy and manure, provides an excellent opportunity for mitigation of greenhouse gas emission and reducing global warming through substituting firewood for cooking. Keywords: biogas, biodigester, activity pattern, burning hour

A randomized trial of the bactericidal effects of chlorhexidine vs povidone-iodine vaginal preparation

Precesarean vaginal preparation significantly reduces postpartum infections. Although povidone-iodine is the most commonly used vaginal antiseptic, evidence suggests that chlorhexidine gluconate may be more effective. We aimed to compare the bactericidal effect of chlorhexidine gluconate and povidone-iodine on vaginal bacterial colony counts in pregnancy. We conducted a prospective randomized controlled trial of vaginal preparation with 0.5% chlorhexidine gluconate vs 10% povidone-iodine vs saline in women undergoing cesarean delivery at ≥34 weeks' gestation. Women in labor or those with ruptured membranes, chorioamnionitis, abnormal placentation, or allergy to study agents were excluded. Vaginal specimens were collected aseptically in the operating room immediately before and 5-10 minutes after vaginal cleansing with 3 sterile sponge sticks. Our primary outcome was postintervention aerobic and anaerobic bacterial colony counts, assessed by blinded investigators. Two-way analysis of variance with simple-effects analysis and Tukey post hoc test were used for multiple group comparisons. Secondary outcomes included baseline colony counts, change in colony counts, adverse events, and maternal infections. A total of 29 women consented and underwent vaginal preparation with chlorhexidine gluconate (n=10), povidone-iodine (n=9), or saline (n=10). Groups were similar with respect to maternal age, body mass index, race, ethnicity, parity, group B streptococcus status, and gestational age. There were no differences in baseline colony counts. Vaginal preparation with povidone-iodine resulted in lower aerobic and anaerobic colony counts compared with chlorhexidine gluconate and saline (P≤.01 and P≤.0001, respectively). Povidone-iodine eliminated more than 99.9% of bacteria, whereas chlorhexidine gluconate and saline eliminated more than 99% and 95% of bacteria, respectively. Although all agents decreased aerobic and anaerobic bacterial counts, 0.5% chlorhexidine gluconate was no more effective than saline in reducing anaerobic bacteria. There were no reported adverse effects or postpartum infections. Compared with 0.5% chlorhexidine gluconate, 10% povidone-iodine was more effective in reducing vaginal bacterial colony counts before cesarean delivery.

Probiotic potential of daily consumption of homemade curd on dental plaque among schoolchildren: A randomized controlled trial

Background: Probiotics are live microorganisms having the potential to convert a dysbiotic bacterial environment into a healthy one. Aim: The aim of the study was to assess the probiotic potential of homemade curd on the quantity and quality of dental plaque among schoolchildren. Materials and Methods: This was a randomized controlled trial. A total of 30 schoolchildren were enrolled in this study, 15 participants in each group. The participants in the intervention group were provided with one cup of freshly prepared homemade curd for a period of 30 days. An evaluation was done at baseline, after 30 days, and after a washout period of 14 days which involved both quantitative and qualitative (Streptococcus mutans, Lactobacilli, and anaerobic bacterial counts in colony-forming units [CFUs]/ml) analysis of dental plaque. Results: A statistically significant difference was not observed for quantitative changes in mean plaque score among the interventional and control groups at various stages of evaluation. Qualitative analysis after 30 days yielded a significant reduction in the number of microbial CFUs of S. mutans ([208 (126.5, 268)] vs. [132 (94.5, 156.5)] P < 0.001), lactobacillus ([3 (1, 5)] vs. [2 (1, 2)] P < 0.001), and anaerobic bacteria ([232 (165, 251)] vs. [190 (127.5, 237.5)] P < 0.001) among the intervention group. Gradual recolonization of microorganism was observed following the cessation of curds. Conclusion: This study concludes that homemade curds have a probiotic effect on both aerobic and anaerobic organisms of dental plaque. However, statistically significant changes were not observed for quantitative analysis of dental plaque.

Optimizing microbiome sequencing for small intestinal aspirates: validation of novel techniques through the REIMAGINE study

BackgroundThe human small intestine plays a central role in the processes of digestion and nutrient absorption. However, characterizations of the human gut microbiome have largely relied on stool samples, and the associated methodologies are ill-suited for the viscosity and low microbial biomass of small intestine samples. As part of the REIMAGINE study to examine the specific roles of the small bowel microbiome in human health and disease, this study aimed to develop and validate methodologies to optimize microbial analysis of the small intestine.ResultsSubjects undergoing esophagogastroduodenoscopy without colon preparation for standard of care were prospectively recruited, and ~ 2 ml samples of luminal fluid were obtained from the duodenum using a custom sterile aspiration catheter. Samples of duodenal aspirates were either untreated (DA-U, N = 127) or pretreated with dithiothreitol (DA-DTT, N = 101), then cultured on MacConkey agar for quantitation of aerobic gram-negative bacteria, typically from the class Gammaproteobacteria, and on blood agar for quantitation of anaerobic microorganisms. DA-DTT exhibited 2.86-fold greater anaerobic bacterial counts compared to DA-U (P = 0.0101), but were not statistically different on MacConkey agar.DNA isolation from DA-U (N = 112) and DA-DTT (N = 43) samples and library preparation for 16S rRNA gene sequencing were also performed using modified protocols. DA-DTT samples exhibited 3.81-fold higher DNA concentrations (P = 0.0014) and 4.18-fold higher 16S library concentrations (P < 0.0001) then DA-U samples. 16S rRNA gene sequencing revealed increases in the detected relative abundances of obligate and facultative anaerobes in DA-DTT samples, including increases in the genera Clostridium (false discovery rate (FDR) P = 4.38E-6), Enterococcus (FDR P = 2.57E-8), Fusobacterium (FDR P = 0.02) and Bacteroides (FDR P = 5.43E-9). Detected levels of Gram-negative enteropathogens from the phylum Proteobacteria, such as Klebsiella (FDR P = 2.73E-6) and Providencia (FDR P < 0.0001) (family Enterobacteriaceae) and Pseudomonas (family Pseudomonadaceae) (FDR P = 0.04), were also increased in DA-DTT samples.ConclusionsThis study validates novel DTT-based methodology which optimizes microbial culture and 16S rRNA gene sequencing for the study of the small bowel microbiome. The microbial analyses indicate increased isolation of facultative and obligate anaerobes from the mucus layer using these novel techniques.

Dietary combination of chitosan nanoparticle and thymol affects feed utilization, digestive enzymes, antioxidant status, and intestinal morphology of Oreochromis niloticus

Currently, the use of phytogenic additives and nanoparticles formulation in fish diets raises great worldwide interest. However, studies on the outcomes of their combination in farmed fish feeding are scarce. Hence, an experiment was planned to examine the effect of chitosan nanoparticle (ChNP), thymol (THY) or their mixture (THY + ChNP) supplementation on growth, whole-body composition, hematological profile, biochemical parameters, intestinal bacterial count, digestive enzymes, and intestinal histomorphology of Oreochromis niloticus. Fish (4.97 ± 0.02 g) were randomly distributed into 4 different treatments. The control group was fed a basal diet, while the other three groups were fed diets supplemented with THY (0.5 g/kg diet), ChNP (5 g/kg diet), and THY + ChNP at the same levels. Results showed that interaction synergistic effect was apparent between the supplemented THY and ChNP on the enhancement of feed and protein utilization, lymphocyte count, HCT, MCV, and MCHC values together with catalase, lipase, and protease activities. The individual THYor ChNP addition to the fish diet significantly improved growth performance indicators, feed utilization, erythrogram profile, oxidative stress parameters, lipase enzyme activity, and lipid sedimentation. Intestinal villus length was significantly increased in ChNP and THY + ChNP supplemented groups. A significant drop of the total anaerobic and aerobic intestinal bacterial count was apparent in THY and ChNP supplemented groups. Conclusively, although the individual addition THY or ChNP improved growth and some health indications, a notable synergistic interaction was obvious following their co-addition in most indicators.

Impact of Pristine Graphene on Intestinal Microbiota Assessed Using a Bioreactor-Rotary Cell Culture System.

The increased use of graphene in consumer products such as food contact materials requires a thorough understanding of its effects on the gastrointestinal commensal bacterial population. During the first phase of study, three representative commensal bacterial species (L. acidophilus, B. longum, and E. coli) were exposed to different concentrations (1, 10, and 100 μg/mL) of pristine graphene for 3, 6, and 24 h in the Bioreactor Rotary Cell Culture System (BRCCS) which allowed a continuous interaction of intestinal microbiota with the pristine graphene without precipitation of test material. The results showed that pristine graphene had dose-dependent effects on the growth of selective bacteria. To study the interaction of graphene with more diverse consortia of intestinal microbiota, fresh fecal samples from laboratory rats were used. Rat fecal slurry (3%) was maintained in an anaerobic environment and treated with different concentrations (1, 10, and 100 μg/mL) of pristine graphene for 3, 6, and 24 h. Counts of viable aerobic and anaerobic bacteria were assessed and fecal slurries were also collected for microbial population shift analysis using quantitative real-time PCR, as well as 16s rRNA sequencing. The results showed a significant two-fold increase in both aerobic and anaerobic bacterial counts (expressed as colony forming unit; CFU) during the first 3 h of exposure to all pristine graphene concentrations. However, 24 h of continuous exposure resulted in a 120% decrease in the CFU of aerobic bacteria at the highest concentration and the anaerobic bacteria CFU remained unchanged. Multivariate analysis of the q-PCR data showed that the exposure time, as well as the graphene concentrations, impacted the bacterial population abundance. Community analysis of graphene-treated fecal samples by 16S sequencing revealed significant alteration of 15 taxonomic groups, including 9 species. The increased abundance of butyrate-producing bacteria (Clostridium fimetarium, Clostridium hylemona, and Sutterella wadsworthensis) was correlated with an increase of the short-chain fatty acid, butyric acid after exposure to graphene. These results clearly indicate that graphene may cause adverse effects on the intestinal microbiome at the doses equal to 100 μg/mL. Further experiments using ex vivo intestinal explants (nonanimal model) could reveal the mechanisms by which graphene could perturb the microbe-host intestinal mucosa homeostasis.