Unveiling the hidden link between oral flora and colorectal cancer: a bidirectional Mendelian randomization analysis and meta-analysis.

Objective: The impact of oral flora on intestinal micro-environment and related diseases has been widely reported, but its role in colorectal cancer (CRC) remains elusive. Methods: A Two-sample Mendelian Randomization (TSMR) analysis was conducted to explore the causal relationship between oral flora and CRC, with the Inverse-Variance Weighted (IVW) serving as the primary method for evaluating this causal relationship. Data on the oral flora were derived from human samples from the tongue and saliva, with all cohort populations originating from Asia. In addition, 2 independent external cohorts were used to validate the positive results and perform a meta-analysis of the final results. Lastly, to balance the effect of positive oral flora on CRC, a Multivariate Mendelian Randomization (MVMR) analysis was also performed. Results: The TSMR analysis revealed that 17 oral flora may have a causal relationship with CRC in the training cohort. Among them, s Haemophilus, g Fusobacterium, s Metamycoplasma salivarium, and s Mogibacterium pumilum were validated in two testing cohorts. Intriguingly, after integrating the results of the 3 cohorts for meta-analysis, 16 associations remained significant. In the training cohort, MVMR analysis demonstrated that s Capnocytophaga ochracea and s Metamycoplasma salivarium retained statistical significance. In one of the testing cohorts, s Metamycoplasma salivarium, s Streptococcus anginosus, and s Streptococcus sanguinis retained statistical significance. In the other testing cohort, s Metamycoplasma salivarium, s Haemophilus, and g Fusobacterium remained significant. Conclusion: s Haemophilus, g Fusobacterium, s Metamycoplasma salivarium, and s Mogibacterium pumilum have a solid causal relationship with the occurrence and development of CRC.

Evaluation of probiotics' efficiency on cariogenic bacteria: randomized controlled clinical study.

BACKGROUND: Probiotics are live beneficial bacteria to human health and their efficiency on oral health is still being investigated. The purpose of this study was to evaluate the level of Streptococcus mutans and Lactobacillus species with and without the use of probiotics for six-months after the treatment of all dental caries under general anesthesia. METHODS: Fifty-eight pediatric patients without any systemic diseases, whose dental treatments were completed under general anesthesia (GA), were included in the study. The patients were recruited in two-groups; Group A: Patients started using probiotics after GA and Group B: Patients did not use probiotics after GA. Saliva samples were taken from all patients on the day before GA (T0), at one-month (T1), three-month (T2) and six-month (T3) follow-up after GA. The counts of cariogenic bacteria were determined by the analysis of saliva samples using real-time polymerase chain reaction. Statistical significance level was accepted as p < 0.05. RESULTS: There was statistically significant difference between Group A and B for T0, T1, T2 and T3 regarding S. mutans (p = 0.001, p = 0.04, p = 0.04, p = 0.03; p < 0.05). However, there was no statistically significant difference between groups regarding Lactobacillus species (p ≥ 0.05). CONCLUSIONS: Probiotic use and treatment of all caries significantly reduced the level of S. mutans but not Lactobacillus species. Furthermore, S. mutans decreased after cessation of probiotics, but it was not statistically significant. TRIAL REGISTRATION: Study was registered as "Effects of Probiotics on Streptococcus mutans and Lactobacillus species" with the registration number of NCT05859646 (16/05/2023) at https://www. CLINICALTRIALS: gov Protocol Registration and Results System.

A pilot study on oral microbiome in electronic cigarettes consumers versus traditional cigarettes smokers.

Oral microorganisms are closely related to oral health, the occurrence of some oral diseases is associated with changes in the oral microbiota, and many studies have demonstrated that traditional smoking can affect the oral microbial community. However, due to the short time since the emergence of e-cigarettes, fewer studies are comparing oral microorganisms for users of e-cigarettes versus cigarettes. We collected saliva from 40 non-smokers (NS), 46 traditional cigarette smokers (TS), and 27 e-cigarette consumers (EC), aged between 18 and 35 years. We performed 16S rRNA gene sequencing on the saliva samples collected to study the effects of e-cigarettes versus traditional cigarettes on the oral microbiome. The results showed that compared with the NS group, the alpha diversity of oral flora in saliva was altered in the TS group, with no significant change in the e-cigarette group. Compared with the NS and EC groups, the relative abundance of Actinomyces and Prevotella was increased in the TS group. However, compared with the NS and TS groups, the relative abundance of Veillonella was increased, and the relative abundance of Porphyromonas and Peptostreptococcus was decreased in the EC group. These results showed that both e-cigarettes and traditional cigarettes could alter the structure and composition of oral microbiota. The use of traditional cigarettes promotes the growth of some anaerobic bacteria, which may contribute to dental decay and bad breath over time. E-cigarettes have a different effect on the structure and composition of the oral microbial community compared to conventional cigarettes. In order to better understand the effects of e-cigarettes and traditional cigarettes on users' mouths, future studies will investigate the relationship between diseases such as dental caries and periodontitis and changes in oral microbial species levels.

Management of a Large Cerebral Abscess in Children Caused by Campylobacter gracilis: A Case Report and Review of the Literature.

Campylobacter gracilis inhabits the gingival sulcus and has been reported to cause various periodontal diseases; it has rarely been reported to cause bacteremia. We describe a case of a two-year-old boy who presented with a consciousness disorder and was transferred to our hospital for treatment of a brain abscess. Magnetic resonance imaging (MRI) showed a 6-cm brain abscess in the right frontal lobe. Urgent drainage and antibiotic administration resulted in a favorable clinical course, and the patient was discharged on the 34th day of hospitalization. Streptococcus anginosus and C. gracilis were identified in the pus. Brain abscesses caused by C. gracilis have rarely been reported, which makes this a valuable case.

Oral microbiota transplantation for intra-oral halitosis: a feasibility analysis based on an oral microbiota colonization trial in Wistar rats.

BACKGROUND: Intra-oral halitosis (IOH) is bad breath produced locally by the mouth in addition to systemic diseases and is one of the main causes of interpersonal communication and psychological disorders in modern society. However, current treatment modalities still only alleviate IOH and do not eradicate it. Therefore, based on the differential performance of oral microecology in IOH patients, we propose a microbiota transplantation treatment aimed at restoring oral microecological balance and analyze its feasibility by oral flora colonization test in Wistar rats. OBJECTIVE: Saliva flora samples were collected from IOH patients and healthy subjects to analyze the feasibility of oral microbiota transplantation (OMT) for the treatment of IOH by the Wistar rat oral flora colonization test. METHODS: Seven patients with IOH who visited the First Affiliated Hospital of Xinjiang Medical University from June 2017 to June 2022 with the main complaint of halitosis and three healthy subjects were randomly selected. A Halimeter portable breath detector was used to record breath values and collect saliva flora samples. Sixteen SPF-grade male Wistar rats were housed in the Animal Experiment Center of Xinjiang Medical University and randomly divided into an experimental group (Group E) and a control group (Group C) for the oral flora colonization test. Species composition and associated metabolic analysis of oral flora during the Wistar rat test using 16SrRNA sequencing technology and PICRUSt metabolic analysis. Also, the changes in the breath values of the rats were recorded during the test. RESULTS: The proportion of Porphyromonas, Fusobacterium, Leptotrichia, and Peptostreptococcus was significantly higher in group E compared to group C after colonization of salivary flora of IOH patients (all P < 0.05), and the abundance with Gemella was zero before colonization, while no colonization was seen in group C after colonization compared to baseline. PICRUSt metabolic analysis also showed significantly enhanced IOH-related metabolic pathways after colonization in group E (all P < 0.05), as well as significantly higher breath values compared to baseline and group C (all P < 0.0001). After colonization by salivary flora from healthy subjects, group E rats showed a decrease in the abundance of associated odor-causing bacteria colonization, a reduction in associated metabolism, and a significant decrease in breath values. In contrast, group C also showed differential changes in flora structure and breath values compared to baseline after salivary flora colonization of IOH patients. CONCLUSIONS: OMT for IOH is a promising green treatment option, but the influence of environmental factors and individual differences still cannot be ignored.

Involvement of oral flora in the role of betel nut-extract-induced ulcers in rats / 中国比较医学杂志

Objective A model for studying oral ulcers induced by betel nut-extract was constructed in rats.Changes in the structure and diversity of oral flora were observed to explore the involvement of oral flora and local inflammatory factors in the pathogenesis of oral ulcers induced by betel nut-extract and to provide theoretical support for the prevention and treatment of oral ulcers in the clinic.Methods Thirty SD rats were randomly divided into normal,model and intervention groups(Guilin watermelon cream,8 mg/d for 7 days),with 10 rats/group.The oral mucosa of rats was subcutaneously injected with 10 g/mL of betel nut-extract to generate an oral ulcer model.The histomorphological changes were observed,and ulcer area and ulcer scores were assessed.Local oral tissue tumor necrosis factor-α(TNF-α),interleukin(IL)-2 and IL-8 levels were determined.Oral mucosal tissues were sampled for HE staining and analyzed for the structural distribution of oral flora and the diversity of microbial communities using high-throughput sequencing method.Results Compared with rats in the normal group,those in the model group had an increased ulcer area,significantly increased ulcer scores(P＜0.01),and significantly increased levels of TNF-α,IL-2 and IL-8 in the oral mucosal tissues(P＜0.01).The amount Streptococcus(P＜0.05)and Veillonella(P＜0.001)in the oral saliva of the model group rats was significantly reduced.The model group rats showed oral mucosal epithelial cell hyperplasia or focal necrosis,mucosal lamina propria edema,and hemorrhage accompanied by mass neutrophil and monocyte infiltration.Compared with the model group rats,the intervention group rats had significantly reduced ulcerated area(P＜0.05,P＜0.01)and ulcer scores(P＜0.05).And oral mucosal tissue levels of TNF-α(P＜0.01),IL-2(P＜0.05)and IL-8(P＜0.05),as well as significantly increased Streptococcus(P＜0.001)and Veillonella(P＜0.01)and significantly reduced Staphylococcus(P＜0.01)in the oral saliva.The degree of lesions in the oral mucosal tissues was significantly improved in the intervention group.Conclusions Betel nut-extract can be used to successfully reproduce a rat model of oral ulcer,and it is speculated that the development of oral ulcers after exposure to betel nut-extract may be related to an imbalance in the oral flora and local tissue inflammatory mediators.

Potential correlation of oral flora with pemphigus vulgaris - A case control study.

Background/purpose: Oral flora is related to various immune-related diseases. Herein we explored the characteristics of oral flora in patients with pemphigus vulgaris (PV) and analyzed the correlation between oral flora and PV. Materials and methods: Twenty-two untreated patients with PV and 12 healthy controls (HC) were included in this case-control study. The characteristics of salivary microbiome were assessed by high-throughput sequencing using the 16S rRNA Illumina MiSeq approach, and differences between the PV and HC groups were determined. The Kyoto Encyclopedia of Genes and Genomes (KEGG) database was applied to screen key metabolic pathways and preliminarily explore potential mechanisms underlying PV occurrence and development. Results: The abundance of oral flora in the PV group was significantly lower than that in the HC group, and there were characteristic changes. The relative abundance of Prevotella and Agrobacterium in the PV group was significantly higher than that in the HC group (P < 0.05) and that of Neisseria, Lautropia, and Fusobacterium was significantly lower (P < 0.05). There was a linear correlation between Prevotella and serum Dsg3 level in PV. KEGG pathway analyses indicated significant differences in nine metabolic pathways between the PV and HC groups (P < 0.05), namely carbohydrate metabolism, digestive system, neurodegenerative disease, glycan biosynthesis and metabolism, drug resistance: antimicrobial, infectious disease: viral, circulatory system, excretory system, and nervous system. Conclusion: The oral flora of patients with PV presented characteristic changes, and several metabolic pathways were affected, including N-glycan biosynthesis and metabolism. Prevotella spp. appear to require the most attention in PV. We believe that oral flora dysbacteriosis contributes to PV occurrence and development.

Semperivium Ruthenicum Koch Extract-Loaded Bio-Adhesive Formulation: A Novel Oral Antioxidant Delivery System for Oxidative Stress Reduction.

Periodontitis is a chronic inflammatory disease that affects the oral cavity and can ultimately lead to tooth loss. Oxidative stress has been identified as a key factor in the development of periodontitis. In recent years, natural polyphenols have gained attention for their anti-inflammatory and antioxidant effects. This study aims to evaluate the potential of a bio-adhesive patch loaded with Semperivium ruthenicum Koch extract, rich in polyphenols, as a novel oral antioxidant delivery system for reducing oxidative stress in periodontitis. The plant extracts were prepared by maceration and were subjected to HPLC analysis for the identification and quantification of polyphenols. The bio-adhesive patches were prepared using a solvent-casting technique and characterized for their technical characteristics and release kinetics. The patches demonstrated satisfactory technical characteristics and followed Korsmeyer-Peppas release kinetics, with the active ingredients diffusing non-Fickian from the polymer matrix as it eroded over time. The bio-adhesive strength of the patches was comparable to other similar formulations, suggesting that the obtained patches can be tested in vivo conditions. The results suggest that treating oral periodontitis with natural polyphenols may effectively scavenge free radicals and regulate cytokine activity, leading to a reduction in oxidative stress. The non-smoking group had a mean saliva antioxidant activity of 7.86 ± 0.66% while the smoking group had a mean value of 4.53 ± 0.15%. Furthermore, treating oral oxidative stress may also contribute to overall gut health, as studies have shown a correlation between oral and gut microbiomes. Therefore, the use of bio-adhesive patches containing polyphenols may provide a promising approach for the treatment of periodontitis and its associated complications.

Commensal Streptococcal Infective Endocarditis of the Native Mitral Valve in a Transcatheter Aortic Valve Replacement (TAVR) Patient: A Heartful, a Handful, and a Mouthful.

An 88-year-old woman with an extensive medical history presented to the hospital with altered mental status, vague abdominal pain, and dysuria. A previous transcatheter aortic valve replacement (TAVR) prosthesis was known to be failing and was suspected to have acquired a vegetation. No other infective endocarditis (IE) stigmata were present. Fortunately, the work-up for replacement was allowed to proceed with a broader cardiac examination from which a mitral vegetation was identified and IE then treated.

Positive feedback loop between dietary nitrate intake and oral health.

Nitrate was once thought to be an inert end-product of endothelial-derived nitric oxide (NO) heme oxidation; however, this view has been radically revised over the past few decades. Following the clarification of the nitrate-nitrite-NO pathway, accumulated evidence has shown that nitrate derived from the diet is a supplementary source of endogenous NO generation, playing important roles in a variety of pathological and physiological conditions. However, the beneficial effects of nitrate are closely related with oral health, and oral dysfunction has an adverse effect on nitrate metabolism and further impacts overall systemic health. Moreover, an interesting positive feedback loop has been identified between dietary nitrate intake and oral health. Dietary nitrate's beneficial effect on oral health may further improve its bioavailability and promote overall systemic well-being. This review aims to provide a detailed description of the functions of dietary nitrate, with an emphasis on the key role oral health plays in nitrate bioavailability. This review also provides recommendations for a new paradigm that includes nitrate therapy in the treatment of oral diseases.

Oral flora of domestic cats in Hong Kong: Identification of antibiotic-resistant strains.

BACKGROUND: As the clinical outcome of bite-associated infection is related to the oral commensals, evaluating their composition and antibiotic susceptibility pattern can provide more information for the antibiotic treatment of wound infections and increase the awareness of the multidrug-resistant bacteria in cat oral flora. AIMS: This study was conducted to identify the various bacterial species in the oral cavity of cats. It aimed to identify the composition of cat oral flora and antibiotic resistant bacterial stains. MATERIALS AND METHODS: Twenty-two cats were sampled for bacterial evaluation. Matrix-assisted laser desorption/ionization time of flight mass spectrometry was used to provide rapid and reliable detection and identification of the bacterial species. Antibiotic susceptibility tests were performed in the identified isolates to determine the antibiotic susceptibility pattern and to detect the multidrug-resistant bacteria in the cat oral cavities. RESULTS: A total of 54 isolates were identified, Pasteurella was the genus most commonly isolated from the oral cavity of cats (19/54, 35.19%), followed by Neisseria spp. (8/54, 14.81%) and Staphylococcus spp. (7/54, 12.96%). Uncommon oral flora were isolated from the samples, including Pasteurella canis, Inquilinus limosus and the Enterobacteriaceae family of Escherichia coli, Klebsiella pneumoniae and Serratia marcescens. Fourteen different multidrug-resistant bacteria were detected, including Pasteurella species (4/14), Bacillus species (2/14), Neisseria species (3/14), Escherichia species (1/14) and Staphylococcus species (4/14). DISCUSSION AND CONCLUSIONS: This study's findings will increase the understanding of the composition of cat oral flora in Hong Kong, which can provide more evidence-based information for the prophylactic treatment of patients with cat bite infections. Moreover, the study identified and detected the antibiotic resistance pattern and multidrug-resistant bacteria in the cat oral cavity, which can help cat owners increase their awareness of maintaining regular oral hygiene for their cats to prevent the spread of pathogens from cats to humans.

Streptococcus constellatus causing concomitant extra and intracranial abscesses complicated with sagittal sinus thrombosis

ABSTRACT Streptococcus constellatus is a gram-positive coccus member of the Streptococcus anginosus group (SAG). It can be found in the oral flora, and may cause abscess more commonly in the gastrointestinal tract, lungs, and heart. Brain abscesses are severe neurological infections with high mortality rates. Streptococcus species other than S. pneumoniae are rare causes of brain abscesses. This case report highlights a severe case of extra and intracranial abscesses due to S. constellatus in an immunocompetent host

The recovery of intestinal barrier function and changes in oral microbiota after radiation therapy injury.

Introduction: Colorectal cancer (CRC) is the third most common malignant tumor, and neoadjuvant chemo-radiotherapy is usually recommended for advanced stage colorectal cancer. Radiotherapy can cause damage to intestinal mucosal barrier, which may be related to perioperative complications. Intestinal microbiota is one of the constituents of the intestinal mucosal biological barrier, and literature reports that patients with CRC have changes in corresponding oral microbiota. This study aims to analyze the levels of immunoglobulin SIgA, inflammatory factors, lymphocyte subsets quantity, and proportion in surgical specimens of intestinal mucosa at different time intervals after radiotherapy, in order to seek investigation for the optimal surgical time after radiotherapy and to provide evidence for finding probiotics or immunomodulators through high-throughput sequencing of bacterial 16s rRNA in patients' saliva microbiota. Ultimately, this may provide new ideas for reducing perioperative complications caused by radiotherapy-induced intestinal damage. Methods: We selected intestinal mucosal tissue and saliva samples from over 40 patients in our center who did not undergo radiotherapy and underwent surgery at different time intervals after radiotherapy. Detection of SIgA was performed using ELISA assay. Western Blotting was used to detect IL-1ß, IL-6, and IL-17 in the intestinal mucosal tissue. Flow cytometry was used to detect CD4 and CD8. And the microbial community changes in saliva samples were detected through 16s rRNA sequencing. Results: After radiotherapy, changes in SIgA, various cytokines, CD4CD8 lymphocyte subsets, and oral microbiota in the intestinal mucosal tissue of rectal cancer patients may occur. Over time, this change may gradually recover. Discussion: In colorectal cancer, oncological aspects often receive more attention, while studies focusing on the intestinal mucosal barrier are less common. This study aims to understand the repair mechanisms of the intestinal mucosal barrier and reduce complications arising from radiotherapy-induced damage. The relationship between oral microbiota and systemic diseases has gained interest in recent years. However, the literature on the oral microbiota after radiotherapy for rectal cancer remains scarce. This study addresses this gap by analysing changes in the salivary microbiota of rectal cancer patients before and after radiotherapy, shedding light on microbiota changes. It aims to lay the groundwork for identifying suitable probiotics or immunomodulators to alleviate perioperative complications and improve the prognosis of CRC.

Case report: Successful management of Parvimonas micra pneumonia mimicking hematogenous Staphylococcus aureus pneumonia.

Parvimonas micra is an anaerobic Gram-positive coccus frequently found in the oral cavity and gastrointestinal tract, but rarely in the lung. Therefore, pneumonia caused by P. micra is also rare. Although there are some reports of P. micra related pneumonia due to aspiration or blood-borne infection with definite remote infection source, there are no reported cases of hematogenous P. micra pneumonia in healthy adults lacking a remote source of infection. Herein, we described the intact disease of P. micra-related pneumonia mimicking hematogenous Staphylococcus aureus pneumonia in terms of chest imagery and diagnosed via metagenomic next-generation sequencing (mNGS). Interestingly, there was no clear remote pathogenic source identified in the patient. Microbiome analysis revealed dysbiosis of the oral flora possibly related to poor oral hygiene and a long history of smoking. The patient was treated with moxifloxacin for 3 months. Ultimately, computed tomography (CT) of the chest showed total resolution of the lung lesion. Clinicians need to update the etiology of community-acquired pneumonia. When antibiotic therapy is not effective, pathogen examination becomes very important. New methods of pathogen detection such as mNGS should be employed to this end. For the treatment of P. micra pneumonia, no standardized course of treatment was reported. Imaging absorption of lung infections may provide a more objective guidance for the duration of antibiotics in P. micra pneumonia.

Safety of De-Escalating Empiric Antimicrobial Agents in Trauma Patients with Indigenous Oral Flora Ventilator-Associated Pneumonia.

Background: Ventilator-associated pneumonia (VAP) is a frequently occurring nosocomial infection in critically ill trauma patients. When bronchoalveolar lavage (BAL) returns with indigenous oral flora (IOF), de-escalating antimicrobial therapy is challenging. Patients and Methods: This is a retrospective review of trauma patients who received broad-spectrum empiric antimicrobial therapy for clinical VAP, and whose BAL culture resulted with >100,000 CFU/mL of IOF from September 1, 2017 to September 1, 2020. Patients were identified using the trauma database and microbiology reports of BALs with IOF. This review evaluated the effect of antibiotic de-escalation on recurrent or persistent pneumonia. Results: Of 51 trauma patients with clinical VAP and IOF, 18 patients (35.3%) had antimicrobial agents de-escalated. De-escalation was driven primarily by the discontinuation of vancomycin, with the continuation of a ß-lactam antibiotic as monotherapy for the remainder of the treatment course (n = 15; 86.7%). The overall rate of either persistent or recurrent VAP in the cohort was 10%, and this did not differ statistically between those who received de-escalation therapy after isolation of IOF and those who did not (16.7% vs. 6.1%; p = 0.224), however, the incidence of acute kidney injury (AKI) was higher in the non-de-escalation group (39.4% vs. 11.1%; p = 0.034). There was no statistical difference in ventilator days, intensive care unit (ICU) length of stay, or hospital length of stay between treatment groups. Conclusions: Trauma patients who develop VAP with isolated BAL cultures of IOF or mixed flora can safely have anti-methicilllin-resistant Staphylococcus aureus (MRSA) antimicrobial agents discontinued, and this may result in decreased rates of AKI.

High through-put sequencing analysis of changes in oral flora in rats before and after zoledronate administration.

The aim of this study was to compare the changes in the oral flora of Sprague-Dawley rats before intraperitoneal injection of zoledronic acid, 6 weeks and 12 weeks after injection. Clinically, some antibiotics effectively treat patients with medicine-related osteonecrosis of the jaws (MRONJ), but the effect of broad-spectrum antibiotics for osteomyelitis of the jaw is not obvious. We therefore speculated that MRONJ may have some dominant bacteria. We used 12 healthy rats for the experiment. One rat was used for haematoxylin and eosin staining, three were used for gene analysis, three for signal molecule research, and five for 16SrDNA high-pass sequencing to compare the changes of flora before intraperitoneal injection of zoledronic acid, and 6 and 12 weeks after injection once every three days. Alpha and beta analysis was used for sequencing data. Analysis of the flora showed that the alpha diversity of the bacteria of rats injected with zoledronic acid was significantly higher than it was before injection (p < 0.05). At the phylum level, Bacteroidetes at 6 and 12 weeks of injection were significantly higher than those before injection (p < 0.05). At the genus level, the proportions of Novophingobium, Dubosiella, Mannheimia, Prevotella, Brevundimonas, and Bacteroides were higher than they were before injection (p < 0.05). The proportions of Lactobacillus, Mannheimia, Brevundimonas, Bacteroides, Roseovarius, Salegentibacter, Marinobacter, and Granulicatella in rats injected for 12 weeks were higher than those before injection (p < 0.05). Zoledronic acid can change the structure of oral flora in SD rats, in which Bacteroides increased and Actinomycetes decreased.

Oral Cavity and Candida albicans: Colonisation to the Development of Infection.

Candida colonisation of the oral cavity increases in immunocompromised individuals which leads to the development of oral candidiasis. In addition, host factors such as xerostomia, smoking, oral prostheses, dental caries, diabetes and cancer treatment accelerate the disease process. Candida albicans is the primary causative agent of this infection, owing to its ability to form biofilm and hyphae and to produce hydrolytic enzymes and candialysin. Although mucosal immunity is activated, from the time hyphae-associated toxin is formed by the colonising C. albicans cells, an increased number and virulence of this pathogenic organism collectively leads to infection. Prevention of the development of infection can be achieved by addressing the host physiological factors and habits. For maintenance of oral health, conventional oral hygiene products containing antimicrobial compounds, essential oils and phytochemicals can be considered, these products can maintain the low number of Candida in the oral cavity and reduce their virulence. Vulnerable patients should be educated in order to increase compliance.

Dental Infections and Risk for Brain Abscess: A Literature Review.

Dental work is commonly accepted as a low-risk procedure but has been associated with serious brain abscesses. Bacteria from the oral cavity can spread to the brain and cause life-threatening infections. In this literature review, the focus was placed on the relevant causative bacteria, surgical procedures, and correlated medical conditions revolving around brain abscesses following dental work. This paper is written from a neurological surgery perspective, using information collected from several case studies, case reviews, and other related published manuscripts. Several risk factors have been identified to predispose oral cavity bacterial infection to cause brain abscess: dental work done in the upper molars; right-to-left shunts in the heart; and poor dental hygiene. If the bacterium of the abscess is correctly identified, there is a greater effectiveness of treatment, but prolonging antibiotic and/or surgical treatment increases morbidity.

Update on Antimicrobial Therapy in Management of Acute Odontogenic Infection in Oral and Maxillofacial Surgery.

This article focuses on the antimicrobial therapy of head and neck infections from odontogenic origin. Odontogenic infections are among the most common infections of the oral cavity. They are sourced primarily from dental caries and periodontal disease (gingivitis and periodontitis). Many odontogenic infections are self-limiting and may drain spontaneously. However, these infections may drain into the anatomic spaces adjacent to the oral cavity and spread along the contiguous facial planes, leading to more serious infections. Antibiotics are an important aspect of care of the patient with an acute odontogenic infection. Antibiotics are not a substitute for definitive surgical management.

Comparing blood culture contamination rates by different sampling methods in a paediatric emergency department.

AIM: Blood culture contamination (BCC) can cause unnecessary hospitalisations and inappropriate use of antibiotics. The aim of this study was to find risk factors associated with BCCs in children and to compare contamination rates between open and closed blood culture collection systems. METHODS: Data were prospectively collected regarding blood cultures obtained in the paediatric emergency department from February 26, 2020, to September 30, 2020, based on the method of drawing blood reported by the obtaining physician. A comparison between contaminated and non-contaminated blood cultures was performed. We also compared the composition of the contaminations in the study period to the same period in 2019. RESULTS: A total of 512 blood cultures were included, 33 (6.4%) of which were contaminated. The only parameter that was associated with an increased rate of contamination by 2.34 fold (95% CI 1.1-4.99, P = 0.028) was obtaining blood through an 'open' system, using a syringe connected to a needle in order to draw blood from an open ended needle. The proportion of contaminations originating from oral flora decreased in the study period by 44.7% as compared to the same period in the previous year (13% vs. 23.5%, P = 0.056). CONCLUSIONS: 'Open system' method, which is commonly used in paediatric emergency departments for blood culture obtainment, was associated with an increase in BCC. Adherence to blood cultures obtainment guidelines, even at the price of two different blood tests, is important in order to reduce BCC rates in children.