Characterization of the unique oral microbiome of children harboring Helicobacter pylori in the oral cavity.

Objective: Helicobacter pylori infection is acquired in childhood via the oral cavity, although its relationship with the characteristics of the oral microbiome has not been elucidated. In this study, we performed comprehensive analysis of the oral microbiome in children and adults with or without H. pylori in the oral cavity. Methods: Bacterial DNA was extracted from 41 adult and 21 child saliva specimens, and H. pylori was detected using PCR. 16S rRNA gene amplification was performed for next-generation sequencing. Bioinformatic analyses were conducted using Quantitative Insights into Microbial Ecology 2 (QIIME 2). Results: Faith's phylogenetic diversity analysis showed a significant difference between H. pylori-negative adult and child specimens in terms of α-diversity (p < 0.05), while no significant difference was observed between H. pylori-positive adult and child specimens. There was also a significant difference in ß-diversity between H. pylori-positive and negative child specimens (p < 0.05). Taxonomic analysis at the genus level revealed that Porphyromonas was the only bacterium that was significantly more abundant in both H. pylori-positive adults and children than in corresponding negative specimens (p < 0.01 and p < 0.05, respectively). Conclusion: These results suggest unique oral microbiome characteristics in children with H. pylori infection in the oral cavity.

Investigation of periodontal disease development and Porphyromonas gulae FimA genotype distribution in small dogs.

In dogs, Porphyromonas gulae is a major periodontal pathogen with 41-kDa proteins polymerizing to form a filamentous structure called fimbriae or pili, termed FimA. FimA is classified into three genotypes: A, B, and C, and there are combinations of types A, B, C, A/B, A/C, B/C, and A/B/C. Periodontal disease is the most common oral disease in small dogs, but the periodontal disease status and P. gulae colonization at each dog age and breed remain unclear. In this study, we stratified 665 small dogs and analyzed the periodontal status and distribution of P. gulae with each FimA genotype. Dogs with periodontal disease and FimA genotype tended to increase with age. The dogs with at least one FimA genotype had significantly more severe periodontal disease compared with P. gulae-negative dogs (P < 0.01). Additionally, periodontal status was significantly associated with specific FimA genotype distribution in Toy Poodles and Chihuahuas (P < 0.05), whereas there was no such association in Dachshunds. These results suggest that the onset of periodontal disease and P. gulae colonization are related and progress with age. The relationship between periodontal disease and FimA genotype may differ depending on the dog breeds.

Effects of mouthwash on periodontal pathogens and glycemic control in patients with type 2 diabetes mellitus.

Periodontitis is known to be associated with type 2 diabetes mellitus (T2DM), and gargling with mouthwash is known to reduce the incidence of periodontitis by inhibiting periodontal pathogens. However, the effects of mouthwash on oral and systemic conditions in patients with T2DM remain unknown. In this study, we investigated the effects of gargling with mouthwash on the number of red complex species, including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, and HbA1c levels in patients with T2DM. Patients were instructed to gargle with water for 6 months, followed by gargling with mouthwash containing chlorhexidine gluconate for the subsequent 6 months. At each clinic visit, saliva was collected and bacterial DNA was extracted to detect red complex species using the polymerase chain reaction technique. The HbA1c level was determined using a blood sample. The number of red complex species significantly decreased in younger or male patients who gargled with mouthwash. Furthermore, HbA1c levels significantly decreased in younger patients or patients with higher HbA1c levels who gargled with mouthwash. These results suggest that gargling with mouthwash reduces the number of red complex species and improves the hyperglycemic status in patients with T2DM, especially younger patients.

Cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion: A case report.

Cerebral hyperperfusion syndrome is a rare but serious complication after revascularization procedures for cerebrovascular diseases. Cerebral hyperperfusion syndrome can develop after treatment of acute ischemic stroke, including intravenous thrombolysis and endovascular treatment of large vessel occlusion. However, to the best of our knowledge, there are no previous reports describing cerebral hyperperfusion syndrome after endovascular treatment of medium vessel occlusion (eg, anterior cerebral artery A2/3 segment). We report a case of cerebral hyperperfusion syndrome after endovascular reperfusion therapy for medium vessel occlusion. A 70-year-old woman with a history of hypertension and dyslipidemia was transferred by ambulance to our hospital because of immobility and slurred speech. She had mild right lower extremity paralysis, and her symptoms appeared improved compared with onset. She was diagnosed with cerebral infarction in the left frontal lobe. After hospitalization, her neurological symptoms worsened and she was referred to our department. We performed endovascular reperfusion therapy for left anterior cerebral artery A2 occlusion. Recanalization was achieved with residual stenosis. Despite the lack of complications associated with the procedure, the patient had prolonged disorientation, severe hemiplegia, and aphasia. Arterial spin labeling demonstrated hyperperfusion in the left anterior cerebral artery area. The symptoms gradually improved under strict blood pressure control. This report provides evidence that cerebral hyperperfusion syndrome can occur even after endovascular treatment for medium vessel occlusion. Arterial spin labeling was useful in detecting hyperperfusion.

Is oral Streptococcus mutans with collagen-binding protein a risk factor for intracranial aneurysm rupture or formation?

OBJECTIVE: Streptococcus mutans (SM) with the collagen-binding protein Cnm is a unique member of the oral resident flora because it causes hemorrhagic vascular disorders. In the multicenter study, we examined the relationship between Cnm-positive SM (CP-SM) and intracranial aneurysm (IA) rupture, which remains unknown. METHODS: Between May 2013 and June 2018, we collected whole saliva samples from 431 patients with ruptured IAs (RIAs) and 470 patients with unruptured IAs (UIAs). Data were collected on age, sex, smoking and drinking habits, family history of subarachnoid hemorrhage, aneurysm size, number of teeth, and comorbidities of lifestyle disease. RESULTS: There was no difference in the positivity rate of patients with CP-SM between the patients with RIAs (17.2%) and those with UIAs (19.4%). The rate of positivity for CP-SM was significantly higher in all IAs <5 mm than in those ≥10 mm in diameter (P=0.0304). In the entire cohort, the rate of positivity for CP-SM was lower in larger aneurysms than in smaller aneurysms (P=0.0393). CONCLUSIONS: The rate of positivity for CP-SM was lower among patients with large UIAs. These findings are consistent with the hypothesis that CP-SM plays a role in the formation of vulnerable IAs that tend to rupture before becoming larger.

Inhibitory Effects of Shikonin Dispersion, an Extract of Lithospermum erythrorhizon Encapsulated in ß-1,3-1,6 Glucan, on Streptococcus mutans and Non-Mutans Streptococci.

Shikonin is extracted from the roots of Lithospermum erythrorhizon, and shikonin extracts have been shown to have inhibitory effects on several bacteria. However, shikonin extracts are difficult to formulate because of their poor water solubility. In the present study, we prepared a shikonin dispersion, which was solubilized by the inclusion of ß-1,3-1,6 glucan, and analysed the inhibitory effects of this dispersion on Streptococcus mutans and non-mutans streptococci. The shikonin dispersion showed pronounced anti-S. mutans activity, and inhibited growth of and biofilm formation by this bacterium. The shikonin dispersion also showed antimicrobial and antiproliferative effects against non-mutans streptococci. In addition, a clinical trial was conducted in which 20 subjects were asked to brush their teeth for 1 week using either shikonin dispersion-containing or non-containing toothpaste, respectively. The shikonin-containing toothpaste decreased the number of S. mutans in the oral cavity, while no such effect was observed after the use of the shikonin-free toothpaste. These results suggest that shikonin dispersion has an inhibitory effect on S. mutans and non-mutans streptococci, and toothpaste containing shikonin dispersion may be effective in preventing dental caries.

Oral and rectal colonization of methicillin-resistant Staphylococcus aureus in long-term care facility residents and their association with clinical status.

Staphylococcus aureus is a commensal bacterium in humans, but it sometimes causes opportunistic infectious diseases such as suppurative skin disease, pneumonia, and enteritis. Therefore, it is important to determine the prevalence of S. aureus and methicillin-resistant S. aureus (MRSA) in individuals, especially older adults. In this study, we investigated the prevalence of S. aureus and MRSA in the oral cavity and feces of residents in long-term care facilities (LTCFs). S. aureus was isolated from the oral cavity of 61/178 (34.3%) participants, including 28 MRSA-positive participants (15.7%), and from the feces of 35/127 (27.6%) participants, including 16 MRSA-positive participants (12.6%). S. aureus and MRSA were isolated from both sites in 19/127 individuals (15.0%) and 10/127 individuals (7.9%), respectively. Among 19 participants with S. aureus isolation from both sites, 17 participants showed the same sequence type (ST) type. Then, we analyzed the correlation of S. aureus and MRSA in the oral cavity and rectum with the participant's condition. S. aureus and MRSA positivity in the oral cavity was significantly related to tube feeding, while there was no correlation of rectal S. aureus/MRSA with any factors. Our findings regarding the oral inhabitation of MRSA and its risk factors indicate the importance of considering countermeasures against MRSA infection in LTCFs.

Porphyromonas gingivalis infection in the oral cavity is associated with elevated galactose-deficient IgA1 and increased nephritis severity in IgA nephropathy.

BACKGROUND: The relationship between the major periodontal bacteria, Porphyromonas gingivalis, and the pathogenesis of IgA nephropathy (IgAN)-particularly with respect to galactose-deficient IgA1 (Gd-IgA1)-has not been fully elucidated. METHODS: Saliva samples from 30 IgAN patients and 44 patients with chronic kidney disease (CKD) were subjected to analysis of P. gingivalis status via polymerase chain reaction using a set of P. gingivalis-specific primers. The associations between P. gingivalis presence and clinical parameters, including plasma Gd-IgA1, were analyzed in each group. RESULTS: Compared with the CKD group, the IgAN group demonstrated significantly higher plasma Gd-IgA1 levels (p < 0.05). Compared with the P. gingivalis-negative subgroup, the P. gingivalis-positive subgroup exhibited significantly higher plasma Gd-IgA1 levels in both IgAN and CKD patients (p < 0.05). Additionally, among IgAN patients, the P. gingivalis-positive subgroup displayed significantly higher plasma Gd-IgA1 and urine protein levels, compared with the P. gingivalis-negative subgroup (p < 0.05). With respect to renal biopsy findings, the frequencies of segmental glomerulosclerosis and tubular atrophy/interstitial fibrosis were significantly greater in the P. gingivalis-positive subgroup than in the P. gingivalis-negative subgroup, according to the Oxford classification of IgAN (p < 0.05). CONCLUSION: Our findings suggest an association between the presence of P. gingivalis in the oral cavity and the pathogenesis of IgAN, mediated by increased levels of Gd-IgA1.

Inhibitory Effect of Adsorption of Streptococcus mutans onto Scallop-Derived Hydroxyapatite.

Hydroxyapatite adsorbs various substances, but little is known about the effects on oral bacteria of adsorption onto hydroxyapatite derived from scallop shells. In the present study, we analyzed the effects of adsorption of Streptococcus mutans onto scallop-derived hydroxyapatite. When scallop-derived hydroxyapatite was mixed with S. mutans, a high proportion of the bacterial cells adsorbed onto the hydroxyapatite in a time-dependent manner. An RNA sequencing analysis of S. mutans adsorbed onto hydroxyapatite showed that the upregulation of genes resulted in abnormalities in pathways involved in glycogen and histidine metabolism and biosynthesis compared with cells in the absence of hydroxyapatite. S. mutans adsorbed onto hydroxyapatite was not killed, but the growth of the bacteria was inhibited. Electron microscopy showed morphological changes in S. mutans cells adsorbed onto hydroxyapatite. Our results suggest that hydroxyapatite derived from scallop shells showed a high adsorption ability for S. mutans. This hydroxyapatite also caused changes in gene expression related to the metabolic and biosynthetic processes, including the glycogen and histidine of S. mutans, which may result in a morphological change in the surface layer and the inhibition of the growth of the bacteria.

Mechanical thrombectomy for middle cerebral artery occlusion caused by intracranial internal carotid artery stenosis: A case report.

Tandem internal carotid artery (ICA)/middle cerebral artery (MCA) occlusions are occasionally observed in patients with acute ischemic stroke. Most of them are caused by lesions at the origin of the ICA. In cases of intracranial ICA stenosis, the formation of a large thrombus causing MCA occlusion is extremely rare. Herein We report a case of acute MCA occlusion caused by intracranial ICA stenosis. A 62-year-old female presented with aphasia, right-side weakness, and a National Institute of Health Stroke Scale (NIHSS) score of 5. Magnetic resonance imaging (MRI) showed early ischemic infarction at the precentral gyrus. Left ICA and M1 occlusion were suspected on magnetic resonance angiography. However, the patient had complained of right-side numbness 6 days before the onset. Hence the stroke was assumed to have progressed slowly, and acute occlusion of the left ICA was eliminated as a suspected diagnosis. After admission, the symptoms worsened. MRI showed enlargement of the cerebral infarction. Computed tomography angiography showed complete occlusion of the left M1 and recanalization of the left ICA with severe stenosis of the petrous portion. The etiology of the MCA occlusion was determined to be atherothromboembolism. Percutaneous transluminal angioplasty (PTA) was performed for ICA stenosis, followed by mechanical thrombectomy (MT) for the MCA occlusion. Recanalization of the MCA was achieved. After Seven days, the NIHSS score reduced from a pre-MT assessment of 17-2. PTA followed by MT was safe and effective for treating MCA occlusion caused by intracranial ICA stenosis.

Five-Year Follow-Up of a Child with Non-Syndromic Oligodontia from before the Primary Dentition Stage: A Case Report.

BACKGROUND: Congenital absence of teeth is a major dental abnormality in pediatric dentistry and the absence of six or more teeth is defined as oligodontia. Few reports of patients with non-syndromic oligodontia without systemic disease have continued dental follow-up from an early age. METHODS: We performed the five-year follow-up from before the eruption of the primary dentition of a Japanese child with non-syndromic oligodontia and analyzed changes in dental arch growth. RESULTS: At the oral examination at the age of 1 year and 2 months, eight primary incisors were congenitally absent. Therefore, we made dentures for the patient at the age of 3 years and 4 months. From the age of 5 years and 1 month, the child received articulation training for dysarthria from a speech therapist to improve the function and appearance of the oral cavity. Measurement of the patient's dental models revealed a particularly narrow dental arch, especially between the primary canines. CONCLUSIONS: Our findings highlight the importance of treatment for patients with non-syndromic oligodontia from an early age by multiple medical professionals, recognizing that the missing teeth affect the growth of the maxillofacial region.

Multiple-Ion Releasing Bioactive Surface Pre-Reacted Glass-Ionomer (S-PRG) Filler: Innovative Technology for Dental Treatment and Care.

Surface Pre-Reacted Glass-ionomer (S-PRG) filler, which releases strontium (Sr2+), borate (BO33-), fluoride (F-), sodium (Na+), silicate (SiO32-), and aluminum (Al3+) ions at high concentrations, is a unique glass filler that are utilized in dentistry. Because of its multiple-ion releasing characteristics, S-PRG filler exhibits several bioactivities such as tooth strengthening, acid neutralization, promotion of mineralization, inhibition of bacteria and fungi, inhibition of matrix metalloproteinases, and enhancement of cell activity. Therefore, S-PRG filler per se and S-PRG filler-containing materials have the potential to be beneficial for various dental treatments and care. Those include restorative treatment, caries prevention/management, vital pulp therapy, endodontic treatment, prevention/treatment of periodontal disease, prevention of denture stomatitis, and perforation repair/root end filling. This review summarizes bioactive functions exhibited by S-PRG filler and its possible contribution to oral health.

Bilateral vertebral artery dissection extending to the left posterior cerebral artery: A case report.

Intracranial artery dissection accounts for a small percentage (1%-2%) of all ischemic strokes. Vertebral artery dissection sometimes extends to the basilar artery but very rarely to the posterior cerebral artery. We report a case of bilateral vertebral artery dissection extending to the left posterior cerebral artery with the characteristic distribution of intramural hematoma. A 51-year-old woman presented with right hemiparesis and dysarthria 3 days after sudden neck pain. Magnetic resonance imaging on admission revealed infarcts in the left thalamus and temporo-occipital lobe and findings suggestive of bilateral vertebral artery dissection. No infarct was detected in the brainstem. The patient was treated conservatively. Initially, we suspected that infarction in the left posterior cerebral artery territory had been caused by artery-to-artery embolism from the dissected vertebral arteries. However, T1-weighted imaging on day 15 of admission revealed intramural hematoma extending from the left vertebral artery to the left posterior cerebral artery. Therefore, we diagnosed bilateral vertebral artery dissection extending to the basilar artery and the left posterior cerebral artery. The patient's symptoms subsequently improved with conservative treatment, and she was discharged with a modified Rankin Scale score of 1 on day 62 of admission. In this case, intramural hematoma of the basilar artery was found in the anterior vessel wall. Brainstem infarction is less likely when intramural hematoma is located in the anterior vessel wall of the basilar artery in vertebrobasilar artery dissection. T1-weighted imaging is useful for the diagnosis of this rare condition and can predict potentially impaired branches and possible symptoms.

cnm-positive Streptococcus mutans is associated with galactose-deficient IgA in patients with IgA nephropathy.

The presence of Streptococcus mutans expressing Cnm protein encoded by cnm (cnm-positive S. mutans) in the oral cavity is associated with immunoglobulin A (IgA) nephropathy (IgAN). However, the precise mechanism by which cnm-positive S. mutans is involved in the pathogenesis of IgAN remains unclear. The present study evaluated glomerular galactose-deficient IgA1 (Gd-IgA1) to clarify the association between the presence of cnm-positive S. mutans and glomerular Gd-IgA1 in patients with IgAN. The presence of S. mutans and cnm-positive S. mutans was evaluated by polymerase chain reaction in saliva specimens from 74 patients with IgAN or IgA vasculitis. Immunofluorescent staining of IgA and Gd-IgA1 using KM55 antibody in clinical glomerular tissues was then performed. There was no significant association between the glomerular staining intensity of IgA and the positive rate of S. mutans. However, there was a significant association between the glomerular staining intensity of IgA and the positive rate of cnm-positive S. mutans (P < 0.05). There was also a significant association between the glomerular staining intensity of Gd-IgA1 (KM55) and the positive rate of cnm-positive S. mutans (P < 0.05). The glomerular staining intensity of Gd-IgA1 (KM55) was not associated with the positive rate of S. mutans. These results suggest that cnm-positive S. mutans in the oral cavity is associated with the pathogenesis of Gd-IgA1 in patients with IgAN.

A Third Supernumerary Tooth Occurring in the Same Region: A Case Report.

The presence of a supernumerary tooth is one of the most common dental anomalies, and surgical treatment is often required to address this anomaly. Moreover, it may lead to malocclusion, and long-term follow-up is important to monitor its status. A 4-year-and-11-month-old boy was referred to our hospital for dental caries treatment. At 5 years and 5 months of age, a radiographic examination showed a supernumerary tooth (first supernumerary tooth) near the permanent maxillary left central incisor, and it was extracted 6 months later. Eighteen months after the extraction of the first supernumerary tooth, a new supernumerary tooth (second supernumerary tooth) was detected in the same region, which was extracted when the patient was aged seven years and seven months. Seven months later, another supernumerary tooth (third supernumerary tooth) was detected and extracted immediately. However, the permanent maxillary left central incisor did not erupt spontaneously even after 6 months. Therefore, surgical exposure was performed, and the central incisor erupted into the oral cavity. This report describes our experience with this patient with three metachronous supernumerary teeth and their management until the eruption of the permanent tooth. This report highlights the importance of long-term follow-up after supernumerary tooth extraction until the permanent teeth in that region have erupted completely.

Possible association of fimA genotype of Porphyromonas gulae with the severity of periodontal disease and the number of permanent teeth in dogs.

Previous research has demonstrated that Porphyromonas gulae (P. gulae) significantly contributes to the development of periodontal disease in dogs. Porphyromonas gulae is divided into three subtypes according to the 41-kDa filamentous appendage (fimA), defined as types A, B, and C. This study aimed to elucidate the association between fimA type of P. gulae with the number of permanent teeth, reflecting the severity of periodontal disease. Two hundred twenty-five dogs were categorized by P. gulae fimA type as negative, type A dominant, type B dominant, and type C dominant. The stage of periodontal disease in P. gulae-positive dogs increased with age, particularly in type C dominant dogs. Correspondingly, the number of permanent teeth in P. gulae fimA type C-dominant dogs was significantly lower than that of P. gulae-negative dogs, suggesting there is a significant association between fimA type of P. gulae and the number of permanent teeth resulting from the development of periodontal disease.

Acute reperfusion therapy via occluded vertebral artery using a guiding sheath for posterior circulation tandem occlusion: illustrative case.

BACKGROUND: Vertebral artery (VA) size, anatomy, and occlusion status should be considered when selecting endovascular access for basilar artery mechanical thrombectomy. In a patient with concomitant basilar artery and VA occlusion and a patent but hypoplastic contralateral VA, the occluded VA should be selected. The authors report a technique that utilizes advancing a guiding sheath with attached dilator via an occluded VA. OBSERVATIONS: A 65-year-old male presented with disturbed consciousness because of an acute infarction of the brainstem and cerebellum caused by a basilar artery occlusion. Cerebral angiography showed a hypoplastic right VA and occlusion of the left VA at the origin. A regular wire was easily advanced through the occlusion and a 4-Fr diagnostic catheter was advanced into the distal left VA. A 6-Fr guiding sheath with attached dilator was placed in the left VA beyond the occlusion by exchanging it over a long wire. After removing the basilar artery thrombus, balloon angioplasty was performed at the left VA origin. Complete revascularization of the posterior circulation was achieved. LESSONS: A guiding sheath with dilator can advance across and dilate a VA occlusion at the origin to provide rapid access to the basilar artery.

Harboring Cnm-expressing Streptococcus mutans in the oral cavity relates to both deep and lobar cerebral microbleeds.

BACKGROUND: Cerebral microbleeds (CMBs) influence long-term prognoses of stroke patients. Streptococcus mutans expressing the collagen-binding protein Cnm induces cerebrovascular inflammation, impairing blood brain barrier integrity and causing cerebral bleeding. Here, we examine the association of Cnm-positive S. mutans with CMBs. METHODS: Acute stroke patients were selected from a single-center registry database. Oral carriage of Cnm-positive or Cnm-negative S. mutans was determined using polymerase chain reaction assays. The associations of Cnm-positive S. mutans with CMB number and specifically the presence of >10 CMBs were examined using quasi-Poisson and logistic regression models, respectively. RESULTS: This study included 3154 stroke patients, of which 428 patients (median [interquartile range] age, 73.0 [63.0-81.0] years; 269 men [62.9%]) underwent oral bacterial examinations. In total, 326 patients harbored S. mutans. After excluding four patients without imaging data, we compared patients with Cnm-positive (n = 72) and Cnm-negative (n = 250) S. mutans. Harboring Cnm-positive S. mutans was independently associated with the presence of >10 CMBs (adjusted odds ratio 2.20 [1.18-4.10]) and higher numbers of deep and lobar CMBs (adjusted risk ratio 1.61 [1.14-2.27] for deep; 5.14 [2.78-9.51] for lobar), but not infratentorial CMBs, after adjusting for age, sex, hypertension, stroke type, National Institutes of Health Stroke Scale score, and cerebral amyloid angiopathy. CONCLUSIONS: Harboring Cnm-positive S. mutans was independently associated with a higher number of CMBs in deep and lobar locations. Reducing Cnm-positive S. mutans in the oral cavity may serve as a novel therapeutic approach for stroke.

Dental radiographic information of term newborn babies within the first month: Analyzing five radiographic cases along with physical attributes in Japan.

BACKGROUND: Although dental radiography is a valuable tool for age estimation in forensic anthropology and odontology, very limited radiological data are available regarding tooth development in healthy newborn babies during the first month of life. AIM: This study aimed to describe the radiological findings of tooth development in babies aged 0 days to 1 month. DESIGN: We analyzed the postmortem findings of five newborn babies with no known natural cause of death who had undergone autopsy, computed tomography (CT), and dental radiography. We estimated the gestational age for the babies aged 0 days and analyzed the condition of mandibular symphysis, existence of tooth germs, and presence or absence of calcification of the first permanent molars of all the babies. RESULTS: The calcified form of 20 deciduous teeth, tooth germs of the permanent upper and lower first molars, and non-calcified mandibular symphysis were observed in each case. However, calcification of the first permanent molar was observed in only two 1-month-old babies. CONCLUSION: The dental radiographic findings and anthropometric measurements of non-skeletonized, non-mummified term babies confirmed calcification of all the deciduous teeth and the first permanent molar at the age of 0 days and 1 month, respectively.

Distribution of periodontopathic bacterial species between saliva and tonsils.

Periodontopathic bacteria cause an inflammatory disease localized in the periodontal tissue and are associated with various conditions in other body parts. The distribution of periodontopathic bacterial species in the tonsils is unknown, even though the tonsils are located close to the oral cavity, and inflammation of the tonsils causes various systemic diseases. We detected the major periodontopathic bacterial species residing in saliva and tonsil specimens from 25 subjects undergoing tonsillectomy. Nine of the ten major periodontopathic bacterial species were detected by polymerase chain reaction of tonsil specimens, among which Campylobacter rectus was the most common (80.0%), followed by Porphyromonas gingivalis (36.0%). The other seven types of periodontopathic bacterial species were distributed with 0% to 25.0% abundance in the tonsil specimens. C. rectus had a high detection rate in tonsil specimens (> 75.0%), regardless of whether it was detected in the corresponding saliva specimens. However, the detection rate for P. gingivalis in tonsil specimens was significantly higher in subjects with P. gingivalis-positive saliva (77.8%) than in those with P. gingivalis-negative saliva (6.3%; P < 0.001). Furthermore, 75.0% of P. gingivalis in tonsil specimens did not have the known fimA gene that encodes the 41-kDa filamentous appendage protein FimA, which is expressed on the cell surface of the bacteria. Our results suggest that certain periodontopathic bacterial species are detected in the tonsils either independently of or depending on their distribution in the oral cavity and may be involved in tonsil-related diseases.