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The Korean Journal of Internal Medicine Jun 2024Recent research has increasingly focused on the role of the gastric microbiome in the development of gastric cancer. We aimed to investigate the changes in the...
BACKGROUND/AIMS
Recent research has increasingly focused on the role of the gastric microbiome in the development of gastric cancer. We aimed to investigate the changes in the microbiome during gastric carcinogenesis in structural and functional aspects, with a specific focus on the association between oral and gastric microbiomes.
METHODS
We collected saliva, gastric juice, and gastric tissue samples from 141 patients at different stages of gastric carcinogenesis and processed them for microbiome analysis using 16S rRNA gene profiling. The alpha and beta diversities were analyzed, and the differences in microbiome composition and function profiles were analyzed among the groups, as well as the correlation between changes in the oral and gastric microbiomes during carcinogenesis.
RESULTS
We observed significant differences in microbial diversity and composition between the disease and control groups, primarily in the gastric juice. Specific bacterial strains, including Schaalia odontolytica, Streptococcus cristatus, and Peptostreptococcus stomatis, showed a significant increase in abundance in the gastric juice in the low-grade dysplasia and gastric cancer groups. Notably, the correlation between the oral and gastric microbiota compositions, increased as the disease progressed. Predictive analysis of the metagenomic functional profiles revealed changes in functional pathways that may be associated with carcinogenesis (ABC transport and two-component systems).
CONCLUSIONS
During gastric carcinogenesis, the abundance of oral commensals associated with cancer increased in the stomach. The similarity in microbial composition between the stomach and oral cavity also increased, implying a potential role of oral-gastric bacterial interactions in gastric cancer development.
PubMed: 38910513
DOI: 10.3904/kjim.2023.490 -
IDCases 2024Common organisms associated with community-acquired pneumonia include , , and . Pneumonia can rarely be caused by an organism such as , as in our case. This organism...
Common organisms associated with community-acquired pneumonia include , , and . Pneumonia can rarely be caused by an organism such as , as in our case. This organism belongs to the Mitis group within the and typically coexists with humans in the oral cavity. We present a case of bacteremia and community acquired pneumonia in a previously healthy 40-year-old male, for whom infective endocarditis has been ruled out, and who was successfully treated with ceftriaxone. While most reported cases of involve infective endocarditis, our case is the first identified instance of community acquired pneumonia caused by . This case highlights that pneumonia with , typically considered a commensal in the oral mucosa microbiota of humans, is possible, as seen in our case. Unlike previous cases in the literature, our patient did not have infective endocarditis, which is the common presentation of this bacterium. Instead, he solely presented with pneumonia, marking the first reported case in the literature of causing pneumonia.
PubMed: 38854926
DOI: 10.1016/j.idcr.2024.e02004 -
Cureus Apr 2024We report here a rare case of spondylodiscitis due to in a healthy 66-year-old male. Due to an abscess causing neurological deficit, which required immediate surgical...
A Rare Case of Streptococcus cristatus Spondylodiscitis Identified by Bacterial 16S rRNA Polymerase Chain Reaction Sequencing: A Case Report and a Review of the Literature.
We report here a rare case of spondylodiscitis due to in a healthy 66-year-old male. Due to an abscess causing neurological deficit, which required immediate surgical intervention, a PCR targeting 16S rRNA was performed on the surgical samples as all blood and tissue cultures remained negative. This molecular assay allowed for the identification of this rare , a member of the mitis group and commensal of the oral cavity, whose pathogenicity remains uncertain although it has been seldom reported in cases of human infections, mostly bacteremia and endocarditis. Notably, our case is distinguished by the absence of comorbidities, although the patient's history was compatible with a dental portal of entry. This case illustrates once more that 16S rRNA PCR can be of great help for documenting the causative pathogen in osteoarticular infections when cultures remain inconclusive. We reviewed in this article the data regarding osteoarticular infections due to and discussed the role of molecular technique in the diagnosis of spondylodiscitis.
PubMed: 38803776
DOI: 10.7759/cureus.59127 -
Biotechnology For Biofuels and... Mar 20242,5-Dimethylpyrazine (2,5-DMP) is important pharmaceutical raw material and food flavoring agent. Recently, engineering microbes to produce 2,5-DMP has become an...
2,5-Dimethylpyrazine (2,5-DMP) is important pharmaceutical raw material and food flavoring agent. Recently, engineering microbes to produce 2,5-DMP has become an attractive alternative to chemical synthesis approach. In this study, metabolic engineering strategies were used to optimize the modified Escherichia coli BL21 (DE3) strain for efficient synthesis of 2,5-DMP using L-threonine dehydrogenase (EcTDH) from Escherichia coli BL21, NADH oxidase (EhNOX) from Enterococcus hirae, aminoacetone oxidase (ScAAO) from Streptococcus cristatus and L-threonine transporter protein (EcSstT) from Escherichia coli BL21, respectively. We further optimized the reaction conditions for synthesizing 2,5-DMP. In optimized conditions, the modified strain can convert L-threonine to obtain 2,5-DMP with a yield of 2897.30 mg/L. Therefore, the strategies used in this study contribute to the development of high-level cell factories for 2,5-DMP.
PubMed: 38500189
DOI: 10.1186/s13068-024-02487-4 -
Microbiology Spectrum Feb 2024Periodontitis has recently been defined as a dysbiotic disease caused by an imbalanced oral microbiota. The transition from commensal microbial communities to...
Periodontitis has recently been defined as a dysbiotic disease caused by an imbalanced oral microbiota. The transition from commensal microbial communities to periodontitis-associated ones requires colonization by specific pathogens, including . We previously reported an antagonistic relationship between and . To determine the role of in altering the interactions of with other oral bacteria in a complex context, we collected dental plaque samples from patients with periodontitis and assigned them to two groups based on the ratios of and . We then characterized the microbial profiles of the dental plaque samples using shotgun metagenomic sequencing and compared the oral microbial composition and functional capabilities of the group with high ratios with the low ratio group. Taxonomic annotation revealed significant differences in the microbial composition at both the genus and species levels between the low and high ratio groups. Notably, a higher microbial diversity was observed in the samples with low ratios. Furthermore, the antibiotic resistance gene profiles of the two groups were also distinct, with a significantly increased abundance of the genes in the dental plaque samples with low ratios. It, therefore, indicates that the ratios influenced the virulence potential of the oral microbiome. Our work shows that enhancing the ratio in oral microbial communities can be an attractive approach for revising the dysbiotic oral microbiome.IMPORTANCEPeriodontitis, one of the most common chronic diseases, is linked to several systemic diseases, such as cardiovascular disease and diabetes. Although is a keystone pathogen that causes periodontitis, its levels, interactions with accessory bacteria and pathobionts in the oral microbiome, and its association with the pathogenic potential of the microbial communities are still not well understood. In this study, we revealed the role of and the ratios of and in modulating the oral microbiome to facilitate a deeper understanding of periodontitis and its progression. The study has important clinical implications as it laid a foundation for developing novel non-antibiotic therapies against and improving the efficiency of periodontal treatments.
Topics: Humans; Porphyromonas gingivalis; Dental Plaque; Periodontitis; Microbiota; Streptococcus
PubMed: 38230927
DOI: 10.1128/spectrum.03482-23 -
Heliyon Sep 2023A 66-year-old male with a history of low back pain was found to have discitis and osteomyelitis. Biopsy and PCR testing revealed infection. This bacteria does not...
A 66-year-old male with a history of low back pain was found to have discitis and osteomyelitis. Biopsy and PCR testing revealed infection. This bacteria does not typically cause disease, and only a few cases in the literature have reported it to cause infection in the bones or joints. This case illustrates that vertebral osteomyelitis with a rare causative agent, , is possible and can be identified with PCR. Treatment typically requires long-term antibiotics tailored to the causative agent for a minimum of 6 weeks and can sometimes include surgical management.
PubMed: 37809561
DOI: 10.1016/j.heliyon.2023.e19616 -
Research Square Aug 2023Periodontitis has been recently defined as a dysbiotic disease resulting from imbalanced oral microbiota. The transition of microbial communities from commensal to...
BACKGROUND
Periodontitis has been recently defined as a dysbiotic disease resulting from imbalanced oral microbiota. The transition of microbial communities from commensal to periodontitis-associated ones likely requires colonization by specific pathogens, including . We previously reported an antagonistic relationship between and and the role of in inhibition of the biofilm formation, invasion, and gingipain enzymatic activity of . Given the importance of as a keystone pathogen of polymicrobial communities, the determinants of levels, its interaction with the core microbiota, and association with the pathogenic potential of the microbial communities need to be addressed.
RESULTS
This present study intends to determine the role of in altering interactions of with other oral bacteria in a complex context. We collected dental plaque samples from periodontitis patients and assigned them into two groups based on their ratios of and . We then characterized microbial profiles of the dental plaque samples using shotgun metagenomic sequencing and subsequently compared oral microbial composition and functional capabilities between groups with high or low ratios. Taxonomic annotation showed significant differences in microbial compositions at both genus and species levels between the two groups. Notably, a higher microbial composition diversity was observed in the samples with low ratios. The antibiotic resistance gene profiles of the two groups are also distinct, with significantly increased diversity and abundance of antibiotic resistance genes in the dental plaque samples with low ratios, which likely lead to elevated virulence potential.
CONCLUSIONS
Overall, our work highlights the importance of ratios in influencing the virulence of the oral microbiome. Approaches to enhance ratios in oral microbial communities will be attractive for revising the dysbiotic oral microbiome.
PubMed: 37674718
DOI: 10.21203/rs.3.rs-3266326/v1 -
New Preventive Strategy against Oral Biofilm Formation in Caries-Active Children: An In Vitro Study.Antibiotics (Basel, Switzerland) Jul 2023Quorum quenching (QQ) is the inhibition of bacterial communication, i.e., quorum sensing (QS). QS is a key mechanism in regulating biofilm formation and phenotype in...
Quorum quenching (QQ) is the inhibition of bacterial communication, i.e., quorum sensing (QS). QS is a key mechanism in regulating biofilm formation and phenotype in complex bacterial communities, such as those found within cariogenic biofilms. Whereas QQ approaches were shown to effectively reduce biomass, knowledge of their impact on the taxonomic composition of oral polymicrobial biofilms remains scarce. Here, we investigate the effect of the QQ lactonase Aii20J on biomass production and taxonomical composition of biofilms. We collected supragingival plaque samples from 10 caries-free and 10 caries-active children and cultured them to generate in vitro biofilms. We describe significant biomass reductions upon Aii20J exposure, as assessed by crystal violet assays. Taxonomical profiling using 16S rRNA gene amplicon sequencing revealed no significant changes in bacterial composition at the genus level. Interestingly, at the species level Aii20J-treatment increased the abundance of and . Both and express pH-buffering enzymes (arginine deiminase and urease, respectively) that catalyze ammonia production, thereby potentially raising local pH and counteracting the biofilm's cariogenic potential. Within the limitations of the study, our findings provide evidence of the biofilm-modulating ability of QQ and offer novel insights into alternative strategies to restore homeostasis within dysbiotic ecosystems.
PubMed: 37627682
DOI: 10.3390/antibiotics12081263 -
Frontiers in Oral Health 2023Periodontitis disproportionately affects different racial and ethnic populations. We have previously reported the higher levels of and lower ratios of to may...
OBJECTIVES
Periodontitis disproportionately affects different racial and ethnic populations. We have previously reported the higher levels of and lower ratios of to may contribute to periodontal health disparities. This prospective cohort study was designed to investigate if ethnic/racial groups responded differently to non-surgical periodontal treatment and if the treatment outcomes correlated to the bacterial distribution in patients with periodontitis before treatment.
METHODS
This prospective cohort pilot study was carried out in an academic setting, at the School of Dentistry, University of Texas Health Science Center at Houston. Dental plaque was collected from a total of 75 African Americans, Caucasians and Hispanics periodontitis patients in a 3-year period. Quantitation of and was carried out using qPCR. Clinical parameters including probing depths and clinical attachment levels were determined before and after nonsurgical treatment. Data were analyzed using one-way ANOVA, the Kruskal-Wallis test, the paired samples -test and the chi-square test.
RESULTS
The gains in clinical attachment levels after treatment significantly differed amongst the 3 groups-Caucasians responded most favorably, followed by African-Americans, lastly Hispanics, while numbers of were highest in Hispanics, followed by African-Americans, and lowest in Caucasians (= 0.015). However, no statistical differences were found in the numbers of amongst the 3 groups.
CONCLUSION
Differential response to nonsurgical periodontal treatment and distribution of are present in different ethnic/racial groups with periodontitis.
PubMed: 37377523
DOI: 10.3389/froh.2023.1212728 -
Journal of Medical Case Reports May 2023Streptococcus cristatus is a member of the Mitis streptococcus group. Like other members of this group, it resides on mucosal surfaces of the oral cavity. However,...
BACKGROUND
Streptococcus cristatus is a member of the Mitis streptococcus group. Like other members of this group, it resides on mucosal surfaces of the oral cavity. However, little is known about its ability to cause disease as there are only a handful of cases in the literature. Two of these cases involved infective endocarditis with significant complications. However, these cases involved additional microbes, limiting the inferences about the pathogenicity of Streptococcus cristatus.
CASE PRESENTATION
A 59-year-old African American male with end-stage cryptogenic cirrhosis and ascites presented with fatigue and confusion. A paracentesis was negative for spontaneous bacterial peritonitis, but two separate blood cultures grew Streptococcus cristatus. Our patient had a history of dental caries and poor oral hygiene, which were likely the source of the infection. Echocardiograms revealed new aortic regurgitation, indicating "possible endocarditis" per the Modified Duke Criteria. However, since his clinical picture and cardiac function were reassuring, we elected against treatment for infective endocarditis. He was treated for bacteremia with a 2-week course of cephalosporins consisting of 8 days of ceftriaxone, transitioning to cefpodoxime after discharge. Despite having end-stage liver disease, our patient did not experience any significant complications from the infection.
CONCLUSION
A patient with end-stage cirrhosis and poor oral hygiene developed bacteremia with an oral bacterium called Streptococcus cristatus. Unlike previous cases in literature, our patient did not meet criteria for a definitive diagnosis of infective endocarditis, and he experienced no other complications from the infection. This suggests coinfectants may have been primarily responsible for the severe cardiac sequelae in prior cases, whereas isolated Streptococcus cristatus infection may be relatively mild.
Topics: Humans; Male; Middle Aged; Oral Hygiene; Dental Caries; Streptococcal Infections; Endocarditis, Bacterial; Endocarditis; Streptococcus pyogenes; Bacteremia
PubMed: 37194080
DOI: 10.1186/s13256-023-03818-z