PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples

Use of saliva-based qPCR diagnostics for the accurate, rapid, and inexpensive detection of strep throat

OBJECTIVES

Outpatient health care facilities are essential for quickly diagnosing common infectious diseases such as bacterial and viral pharyngitis. The only form of pharyngitis requiring antibiotics is strep throat (ST); however, antibiotic prescription rates are much higher than ST prevalence, suggesting antibiotics are being inappropriately prescribed. Current rapid ST diagnostics may be contributing to this problem due to the low sensitivity and variable specificity of these tests. It is best practice to verify a negative ST diagnosis with a group A Streptococcus (GAS) culture, but many clinics do not perform this test due to the additional cost and 24-72 h required to obtain results. This indicates there is great need for more accurate rapid diagnostic tools in outpatient facilities. We hypothesized that next generation qPCR technology could be adapted to detect GAS DNA from saliva samples (instead of the traditional throat swab) by creating a simple, fast, and inexpensive protocol.

METHODS

Saliva specimens collected from patients at James Madison University Health Center were used to test the effectiveness of our Chelex 100-based rapid DNA extraction method, followed by a fast protocol developed for the Open qPCR machine to accurately detect ST.

RESULTS

Our final saliva processing and qPCR protocol required no specialized training to perform and was able to detect ST with 100 % sensitivity and 100 % specificity (n=102) in 22-26 min, costing only $1.12 per sample.

CONCLUSIONS

Saliva can be rapidly analyzed via qPCR for the accurate and inexpensive detection of ST.

Accuracy of upper respiratory tract samples to diagnose Mycobacterium tuberculosis: a systematic review and meta-analysis

BACKGROUND

Pulmonary tuberculosis due to Mycobacterium tuberculosis can be challenging to diagnose when sputum samples cannot be obtained, which is especially problematic in children and older people. We systematically appraised the performance characteristics and diagnostic accuracy of upper respiratory tract sampling for diagnosing active pulmonary tuberculosis.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Cinahl, Web of Science, Global Health, and Global Health Archive databases for studies published between database inception and Dec 6, 2022 that reported on the accuracy of upper respiratory tract sampling for tuberculosis diagnosis compared with microbiological testing of sputum or gastric aspirate reference standard. We included studies that evaluated the accuracy of upper respiratory tract sampling (laryngeal swabs, nasopharyngeal aspirate, oral swabs, saliva, mouth wash, nasal swabs, plaque samples, and nasopharyngeal swabs) to be tested for microbiological diagnosis of tuberculous (by culture and nucleic acid amplification tests) compared with a reference standard using either sputum or gastric lavage for a microbiological test. We included cohort, case-control, cross-sectional, and randomised controlled studies that recruited participants from any community or clinical setting. We excluded post-mortem studies. We used a random-effects meta-analysis with a bivariate hierarchical model to estimate pooled sensitivity, specificity, and diagnostics odds ratio (DOR; odds of a positive test with disease relative to without), stratified by sampling method. We assessed bias using QUADAS-2 criteria. This study is registered with PROSPERO (CRD42021262392).

FINDINGS

We screened 10 159 titles for inclusion, reviewed 274 full texts, and included 71, comprising 119 test comparisons published between May 13, 1933, and Dec 19, 2022, in the systematic review (53 in the meta-analysis). For laryngeal swabs, pooled sensitivity was 57·8% (95% CI 50·5-65·0), specificity was 93·8% (88·4-96·8), and DOR was 20·7 (11·1-38·8). Nasopharyngeal aspirate sensitivity was 65·2% (52·0-76·4), specificity was 97·9% (96·0-99·0), and DOR was 91·0 (37·8-218·8). Oral swabs sensitivity was 56·7% (44·3-68·2), specificity was 91·3% (CI 81·0-96·3), and DOR was 13·8 (5·6-34·0). Substantial heterogeneity in diagnostic accuracy was found, probably due to differences in reference and index standards.

INTERPRETATION

Upper respiratory tract sampling holds promise to expand access to tuberculosis diagnosis. Exploring historical methods using modern microbiological techniques might further increase options for alternative sample types. Prospective studies are needed to optimise accuracy and utility of sampling methods in clinical practice.

FUNDING

UK Medical Research Council, Wellcome, and UK Foreign, Commonwealth and Development Office.

Young people awareness about possibility of transmitting microorganisms by kissing

Relevance. Currently, many ideas about the manifestation of emotions between people are changing, but kissing remains one of the most important forms of social interaction. There is a lot of information about the multitude of pathogens transmitted with kisses, however, most people are not aware of it. This topic is not paid enough attention to, both in society as a whole and among the youth audience. The aim of the study . This research aims to identify the degree of awareness among young people about the possibility of transmission of various microorganisms during kissing, as well as to determine the relevance of this problem . Materials and Methods. Analysis of scientific literature on microorganisms transmitted by contact of the mucous membranes of the oral cavity. The empirical method consisted of testing, which involved 140 people aged 16 to 25 years. The survey included six questions to assess the level of knowledge about infectious agents transmitted with kisses, as well as the relevance of this topic among young people. Results and Discussion. The survey reveals that 97 % of respondents know that the transmission of bacterial infection is possible with a kiss, while 57 % have heard about the danger of transmission of only some microorganisms or do not know about them at all. Every sixth participant of the survey (18 %) has personally encountered or knows from acquaintances that they have suffered from infectious diseases caused by kissing. 88 % of respondents believe that this topic is poorly covered in the media. It should be emphasized that 91.4 % of the respondents would like to learn more about this topic. An average of 65 % of respondents are interested in protectеtive factors of the oral cavity and potential pathogens of diseases of the upper respiratory tract’s mucous membranes, 56.4 % of young people would like to learn more the functioning of the oral immune system. Conclusion. The study has shown that the topic of infections’ transmission during kissing is relevant among young people. Since not enough attention is paid to this issue in the society, the amount of available information on this topic is rather little. The majority of respondents would like to learn more about the possible transmission of infectious diseases’ pathogens during kissing.

Feasibility and Sensitivity of Saliva GeneXpert MTB/RIF Ultra for Tuberculosis Diagnosis in Adults in Uganda

The objective of this prospective observational study carried out at China-Uganda Friendship Hospital-Naguru in Kampala, Uganda, was to determine the performance of GeneXpert MTB/RIF Ultra (Xpert Ultra) molecular testing on saliva for active tuberculosis (TB) disease among consecutive adults undergoing TB diagnostic evaluation who were Xpert Ultra positive on sputum. We calculated sensitivity to determine TB diagnostic performance in comparison to a composite reference standard of Mycobacterium tuberculosis liquid and solid cultures on two spot sputum specimens. Xpert Ultra on a single saliva sample had a sensitivity of 90% (95% confidence interval [CI], 81 to 95%) relative to the composite sputum culture-based reference standard, similar to the composite sensitivity of 87% (95% CI, 77 to 94%) for fluorescence microscopy (FM) for acid-fast bacilli on two sputum smears. The sensitivity of salivary Xpert Ultra was 24% lower (95% CI for difference, 2 to 48%; P = 0.003) among persons living with HIV (71%; 95% CI, 44 to 90%) than among persons living without HIV (95%; 95% CI, 86 to 99%) and 46% higher (95% CI, 14 to 77%; P < 0.0001) among FM-positive (96%; 95% CI, 87 to 99%) than among FM-negative (50%; 95% CI, 19 to 81%) patients. The semiquantitative Xpert Ultra grade was systematically higher in sputum than in a paired saliva sample from the same patient. In conclusion, molecular testing of saliva for active TB diagnosis was feasible and almost as sensitive as molecular testing of sputum in a high TB burden setting. IMPORTANCE Tuberculosis is among the leading causes of morbidity and mortality worldwide, in large part because >3 million people go undiagnosed and untreated each year. Sputum has been the mainstay for TB diagnosis for over a century but can be difficult for patients to produce. In addition, the vigorous coughing required during sputum collection can lead to infection of nearby individuals and health workers. In this case-only study, applying the ultra-sensitive GeneXpert MTB/RIF Ultra molecular diagnostic assay to saliva detected 90% of culture-confirmed TB cases among 81 adults who were undergoing TB evaluation at the outpatient department of a general hospital in Uganda and tested sputum GeneXpert MTB/RIF Ultra positive. These results suggest that saliva may be a feasible and sensitive alternative to sputum for TB diagnosis, thereby meeting two key metrics proposed by the World Health Organization in its target performance profile for a nonsputum test for TB.

Upregulation of Toll-like Receptor 2 in Dental Primary Afferents Following Pulp Injury

Pulpitis (toothache) is a painful inflammation of the dental pulp and is a prevalent problem throughout the world. This pulpal inflammation occurs in the cells inside the dental pulp, which have host defense mechanisms to combat oral microorganisms invading the pulp space of exposed teeth. This innate immunity has been well studied, with a focus on Toll-like receptors (TLRs). The function of TLR4, activated by Gram-negative bacteria, has been demonstrated in trigeminal ganglion (TG) neurons for dental pain. Although Gram-positive bacteria predominate in the teeth of patients with caries and pulpitis, the role of TLR2, which is activated by Gram-positive bacteria, is poorly understood in dental primary afferent (DPA) neurons that densely innervate the dental pulp. Using Fura-2 based Ca²⁺ imaging, we observed reproducible intracellular Ca²⁺ responses induced by Pam₃CSK₄ and Pam₂CSK₄ (TLR2-specific agonists) in TG neurons of adult wild-type (WT) mice. The response was completely abolished in TLR2 knock-out (KO) mice. Single-cell RT-PCR detected Tlr2 mRNA in DPA neurons labeled with fluorescent retrograde tracers from the upper molars. Using the mouse pulpitis model, real-time RT-PCR revealed that Tlr2 and inflammatory-related molecules were upregulated in injured TG, compared to non-injured TG, from WT mice, but not from TLR2 KO mice. TLR2 protein expression was also upregulated in injured DPA neurons, and the change was corresponded with a significant increase in calcitonin gene-related peptide (CGRP) expression. Our results provide a better molecular understanding of pulpitis by revealing the potential contribution of TLR2 to pulpal inflammatory pain.

Extrapulmonary Tuberculosis—An Update on the Diagnosis, Treatment and Drug Resistance

Pathogenic Mycobacterium tuberculosis complex organisms (MTBC) primarily cause pulmonary tuberculosis (PTB); however, MTBC are also capable of causing disease in extrapulmonary (EP) organs, which pose a significant threat to human health worldwide. Extrapulmonary tuberculosis (EPTB) accounts for about 20–30% of all active TB cases and affects mainly children and adults with compromised immune systems. EPTB can occur through hematogenous, lymphatic, or localized bacillary dissemination from a primary source, such as PTB, and affects the brain, eye, mouth, tongue, lymph nodes of neck, spine, bones, muscles, skin, pleura, pericardium, gastrointestinal, peritoneum, and the genitourinary system as primary and/or disseminated disease. EPTB diagnosis involves clinical, radiological, microbiological, histopathological, biochemical/immunological, and molecular methods. However, only culture and molecular techniques are considered confirmatory to differentiate MTBC from any non-tuberculous mycobacteria (NTM) species. While EPTB due to MTBC responds to first-line anti-TB drugs (ATD), drug susceptibility profiling is an essential criterion for addressing drug-resistant EPTB cases (DR-EPTB). Besides antibiotics, adjuvant therapy with corticosteroids has also been used to treat specific EPTB cases. Occasionally, surgical intervention is recommended, mainly when organ damage is debilitating to the patient. Recent epidemiological studies show a striking increase in DR-EPTB cases ranging from 10–15% across various reports. As a neglected disease, significant developments in rapid and accurate diagnosis and better therapeutic interventions are urgently needed to control the emerging EPTB situation globally. In this review, we discuss the recent advances in the clinical diagnosis, treatment, and drug resistance of EPTB.

Primary Laryngeal Tuberculosis: Our Experiences at a Tertiary Care Teaching Hospital in Eastern India

INTRODUCTION

Primary laryngeal tuberculosis is a chronic bacterial infection of the larynx by Mycobacterium tuberculosis without affecting the lungs. It is a rare type of extrapulmonary tuberculosis seen in clinical practice.

OBJECTIVES

This study aimed to evaluate the clinical presentation, diagnosis, and treatment of primary laryngeal tuberculosis at a tertiary care teaching hospital in eastern India.

MATERIALS AND METHODS

This is a retrospective study of 11 cases of primary laryngeal tuberculosis managed between December 2013 and January 2018. The detailed clinical presentations, investigations, and treatment of primary laryngeal tuberculosis of the patients were studied.

RESULTS

Primary laryngeal tuberculosis is common in men with mean age of 38.63 years. Hoarseness of the voice is the most common symptom, and the most common site for primary laryngeal tuberculosis is the vocal fold with ulcerative lesion. Endoscopic examinations of the larynx in laryngeal tuberculosis are nonspecific and are to be confused with laryngeal cancer. Histopathological and bacteriological examinations are confirmatory tests for the diagnosis. After confirmation of the diagnosis, all patients had taken antitubercular therapy for 6 months, which gave excellent outcome.

CONCLUSIONS

Delayed diagnosis or untreatable laryngeal tuberculosis will lead to high morbidity and mortality of the patient. Although primary laryngeal tuberculosis has nonspecific clinical presentations, it is very important to have a high index of suspiciousness to rule out tubercular lesion in the larynx as this disease is curable.

"The dead shall be raised": Multidisciplinary analysis of human skeletons reveals complexity in 19th century immigrant socioeconomic history and identity in New Haven, Connecticut

In July 2011, renovations to Yale-New Haven Hospital inadvertently exposed the cemetery of Christ Church, New Haven, Connecticut’s first Catholic cemetery. While this cemetery was active between 1833 and 1851, both the church and its cemetery disappeared from public records, making the discovery serendipitous. Four relatively well-preserved adult skeletons were recovered with few artifacts. All four individuals show indicators of manual labor, health and disease stressors, and dental health issues. Two show indicators of trauma, with the possibility of judicial hanging in one individual. Musculoskeletal markings are consistent with physical stress, and two individuals have arthritic indicators of repetitive movement/specialized activities. Radiographic analyses show osteopenia, healed trauma, and other pathologies in several individuals. Dental calculus analysis did not identify any tuberculosis indicators, despite osteological markers. Isotopic analyses of teeth indicate that all four were likely recent immigrants to the Northeastern United States. Nuclear and mitochondrial DNA were recovered from three individuals, and these analyses identified ancestry, hair/eye color, and relatedness. Genetic and isotopic results upended our initial ancestry assessment based on burial context alone. These individuals provide biocultural evidence of New Haven’s Industrial Revolution and the plasticity of ethnic and religious identity in the immigrant experience. Their recovery and the multifaceted analyses described here illuminate a previously undescribed part of the city’s rich history. The collective expertise of biological, geochemical, archaeological, and historical researchers interprets socioeconomic and cultural identity better than any one could alone. Our combined efforts changed our initial assumptions of a poor urban Catholic cemetery’s membership, and provide a template for future discoveries and analyses.

Oral Biofluid Biomarker Research: Current Status and Emerging Frontiers

Salivary diagnostics is a rapidly advancing field that offers clinicians and patients the potential of rapid, noninvasive diagnostics with excellent accuracy. In order for the complete realization of the potential of saliva, however, extensive profiling of constituents must be conducted and diagnostic biomarkers must be thoroughly validated. This article briefly overviews the process of conducting a study of salivary biomarkers in a patient cohort and highlights the studies that have been conducted on different classes of molecules in the saliva. Emerging frontiers in salivary diagnostics research that may significantly advance the field will also be highlighted.

Tuberculosis: Occupational risk among dental healthcare workers and risk for infection among dental patients. A meta-narrative review

OBJECTIVES

Tuberculosis transmission among healthcare workers (HCWs) and patients is due to the level of Mycobacterium tuberculosis (MT) circulation in the community and in the healthcare settings where HCWs are active. In contrast, most papers about dentistry report that dental HCWs (DHCWs) and patients are at relatively high risk, mainly based on tuberculosis case series that occurred in the 80's-90's. This meta-narrative review was designed to evaluate the tuberculosis risk in dentistry accounting for the historical-geographical contexts.

DATA

All available studies reporting data on MT infection (active/latent tuberculosis, tuberculin skin test) among patients and DHCWs.

SOURCES

PubMed, Scopus, GOOGLE Scholar.

KEYWORDS

MT/tuberculosis and dentistry/dentist/dental/dent*.

RESULTS

238 of the 351 titles were excluded because did not concern dental healthcare providing, 94 papers were excluded because they did not provide original data. Thirteen studies on occupational risk, nine on transmission to patients remained. Some, often non-confirmed, cases of MT infection among patients were reported in specific historical-geographical contexts where MT was endemic. The risk of active pulmonary tuberculosis transmission from infected DHCWs to patients is minimal today, provided that the basic infection control guidelines are applied. The development of active tuberculosis among DHCWs is occasional and is associable to MT circulation rather than dental healthcare providing.

CLINICAL SIGNIFICANCE

Tuberculosis transmission in dental healthcare settings was due to the lack of basic infection control measures, while the risk is acceptable (i.e., similar to the general population) nowadays. Therefore, tuberculosis transmission can be safely prevented wearing gloves and surgical mask and providing regular air changes in the operative and non-operative dental healthcare settings. Precautionary Principle-based measures are implementable when patients with active pulmonary tuberculosis are routinely treated.

Salivary biomarkers: toward future clinical and diagnostic utilities

The pursuit of timely, cost-effective, accurate, and noninvasive diagnostic methodologies is an endeavor of urgency among clinicians and scientists alike. Detecting pathologies at their earliest stages can significantly affect patient discomfort, prognosis, therapeutic intervention, survival rates, and recurrence. Diagnosis and monitoring often require painful invasive procedures such as biopsies and repeated blood draws, adding undue stress to an already unpleasant experience. The discovery of saliva-based microbial, immunologic, and molecular biomarkers offers unique opportunities to bypass these measures by utilizing oral fluids to evaluate the condition of both healthy and diseased individuals. Here we discuss saliva and its significance as a source of indicators for local, systemic, and infectious disorders. We highlight contemporary innovations and explore recent discoveries that deem saliva a mediator of the body's physiological condition. Additionally, we examine the current state of salivary diagnostics and its associated technologies, future aspirations, and potential as the preferred route of disease detection, monitoring, and prognosis.

Salivary diagnostics: a brief review

Early detection of disease plays a crucial role for treatment planning and prognosis. Saliva has great potential as a diagnostic fluid and offers advantage over serum and other biological fluids by an economic and noninvasive collection method for monitoring of systemic health and disease progression. The plethora of components in this fluid can act as biomarkers for diagnosis of various systemic and local diseases. In this review paper, we have emphasized the role of salivary biomarkers as diagnostic tools.

Exploring alternative biomaterials for diagnosis of pulmonary tuberculosis in HIV-negative patients by use of the GeneXpert MTB/RIF assay

The utility of the GeneXpert MTB/RIF (Xpert) assay for detection of Mycobacterium tuberculosis in sputum samples has been extensively studied. However, the performance of the Xpert assay as applied to other readily accessible body fluids such as exhaled breath condensate (EBC), saliva, urine, and blood has not been established. We used the Xpert assay to test EBC, saliva, urine, and blood samples from HIV-negative, smear- and culture-positive pulmonary tuberculosis (TB) patients for the presence of M. tuberculosis. To compare the ability of the assay to perform bacterial load measurements on sputum samples with versus without sample processing, the assay was also performed on paired direct and processed sputum samples from each patient. The Xpert assay detected M. tuberculosis in none of the 26 EBC samples (sensitivity, 0.0%; 95% confidence interval [95% CI], 0.0%, 12.9%), 10 of the 26 saliva samples (sensitivity, 38.5%; 95% CI, 22.4%, 57.5%), 1 of 26 urine samples (sensitivity, 3.8%; 95% CI, 0.7%, 18.9%), and 2 of 24 blood samples (sensitivity, 8.3%; 95% CI, 2.3%, 25.8%). For bacterial load measurements in the different types of sputum samples, the cycle thresholds of the two M. tuberculosis-positive sputum types were well correlated (Spearman correlation of 0.834). This study demonstrates that the Xpert assay should not be routinely used to detect M. tuberculosis in EBC, saliva, urine, or blood samples from HIV-negative patients suspected of having pulmonary tuberculosis. As a test of bacterial load, the assay produced similar results when used to test direct versus processed sputum samples. Sputum remains the optimal sample type for diagnosing pulmonary tuberculosis in HIV-negative patients with the Xpert assay.

Nasopharyngeal tuberculosis

Today, the opportunity to see tuberculosis is decreasing. Nasopharyngeal tuberculosis is a rare entity, even in endemic tuberculosis areas. A case of nasopharyngeal tuberculosis is described. A 28-year-old woman presented with a sore throat. Irregular mucosal thickening was seen in the nasopharynx. Staining for acid-fast bacilli was positive (Gaffky 1), and the PCR test was positive for Mycobacterium tuberculosis from pharyngeal mucus. Computed tomography showed mucosal thickening in the pharynx and old pulmonary tuberculosis in the right upper lobe. Multiple anti-tuberculosis drug therapy was performed for 6 months. A few days after the initiation of therapy, the pharyngeal pain subsided. The irregular mucosal thickening was quite thin after 1 month of multidrug therapy and was no longer observed after 2 months. A case of nasopharyngeal tuberculosis is reported. A good result was obtained with multiple anti-tuberculous drug therapy for 6 months. Nasopharyngeal tuberculosis should be considered in the differential diagnosis of a white nasopharyngeal coating, especially in a patient with a history of pulmonary tuberculosis.

Saliva as a diagnostic medium

BACKGROUND

This is a review of current knowledge on the use of saliva, gingival cervical fluid and mucosal transudate in the detection of some oral and systemic diseases as well as drugs. Oral fluid is a diagnostic medium that can be easily collected and with minimal invasion but it has been neglected in the past. Today, saliva is being used more often to diagnose: HIV virus, oro-facial and systemic tumors, cardiovascular disease and in detecting addictive substances. Neutropil levels in saliva may also indicate successful bone marrow transplant. Oral fluid is now systematically being researched and oral fluid analysis is being compared with the analysis of other diagnostic media such as blood and urine. A number of recent studies have focused on oncogenic marker detection and its monitoring in saliva. The latest clinical and laboratory findings on diagnostic markers of oropharyngeal carcinoma in oral fluid could be the beginning of their wider use as a diagnostic medium. Oral fluid can also be also used to diagnose other malignancies such as breast cancer which was one of the first malignant tumors to be detected using genetic protein biomarkers. Raised levels of CA15-3 and the epidermal growth factor (EGF) receptor have been found in patients with breast cancer and elevated levels of CA 125 and the glycoprotein complex in the saliva of ovarian cancer patients.

CONCLUSION

Doubtless, the diagnostic value of saliva, aided by current technological development will increase rapidly in the near future.

Inhibition of biofilms associated with dentures and toothbrushes by tetrasodium EDTA

AIMS

We examined the efficacy of tetrasodium EDTA in eradicating biofilms derived from salivary inocula or pure cultures of Candida albicans on discs of polymethyl methacrylate (PMMA) denture base or on toothbrushes that had been used normally for 4-8 weeks. Its efficiency in virus neutralization was also determined.

METHODS AND RESULTS

Overnight (16 h) treatment with 4% (w/v) tetrasodium EDTA solution reduced salivary and C. albicans biofilm viable counts by > or =99%. Biofilm removal was confirmed using confocal laser scanning microscopy. Presence/absence of sucrose during biofilm formation had no effect on killing efficacy. Prolonged treatment of PMMA with tetrasodium EDTA did not influence subsequent formation of C. albicans biofilms or affect surface roughness of the PMMA, but it reduced subsequent biofilm formation from a salivary inoculum. Infectivities of herpes simplex virus and polio virus suspensions were reduced by >99.99% by treatment for 1 and 2 h, respectively.

CONCLUSIONS

Tetrasodium EDTA solution efficiently disinfected toothbrushes and PMMA discs, with the detachment of biofilms, and rapidly neutralized both nonenveloped and enveloped viruses.

SIGNIFICANCE AND IMPACT OF THE STUDY

Dentures and toothbrushes become contaminated by bacterial biofilms and by viruses. There is a need for disinfection methods that are rapidly effective, cost-effective, nontoxic and easily implemented. These studies indicate that tetrasodium EDTA solution has disinfection applications in the oral care field.

Rapid detection of the cariogenic pathogens Streptococcus mutans and Streptococcus sobrinus using loop-mediated isothermal amplification

INTRODUCTION

Streptococcus mutans and Streptococcus sobrinus are associated with the development of dental caries in humans. In this study, we developed a rapid, sensitive method for detecting these major cariogenic pathogens using loop-mediated isothermal amplification (LAMP). The assay procedure is quite simple: the amplification is carried out in a single tube under isothermal conditions at 63 degrees C, and the result can be obtained in less than 1 h.

METHODS

Initially, a set of six primers was designed by targeting S. mutans-specific and S. sobrinus-specific regions, identified using the genomic subtractive hybridization technique. We evaluated the specificities and sensitivities of these assays. Furthermore, we detected and quantified these bacteria in saliva and carious dentin from eight children.

RESULTS

The sensitivities of the S. mutans-specific and S. sobrinus-specific LAMP methods, examined using agarose gel electrophoresis, were each one cell for a 30-min reaction. The detection limits using real-time turbidimetry analysis were 1 to 10(7) cells (3.28 x 10(1) to 3.28 x 10(8) fg S. mutans template DNA) per reaction tube and 1 to 10(5) cells (2.72 x 10(3) to 2.72 x 10(8) fg S. sobrinus template DNA) per reaction tube. Using these assays, we detected and quantified these cariogenic bacteria for evaluation of the LAMP assay for clinical diagnosis.

CONCLUSIONS

Our results suggest that the LAMP-based assay in combination with subtractive hybridization is valuable for preparing species-specific primers for closely related species. Furthermore, the LAMP-based assay will be a useful tool for the rapid and sensitive prediction of dental caries.

Submandibular tuberculous lymphadenitis after endodontic treatment of the mandibular first premolar tooth: report of a case

Cervical tuberculous lymphadenitis (scrofula) is an infectious granulomatous disease that requires a precise diagnosis. The differential diagnosis involves mainly the pathologic conditions involving the regional lymph nodes and the submandibulary salivary glands. Although tuberculous lesions generally develop secondary to pulmonary disease, clinical manifestations are occasionally seen with no evidence of involvement of the lungs. In this report, a case of tuberculous submandibular lymphadenitis developing after endodontic treatment of the mandibular first premolar tooth is described.

Primary tuberculosis of the tongue: a rare nodular presentation

We report a case of a 38-year-old male who presented to us with a nodular swelling of the tongue with cervical lymphadenopathy suggestive of a malignancy. The lesion was diagnosed to be of tuberculous origin and the patient responded well to anti-tubercular chemotherapy.

Orale Manifestation einer miliaren Tuberkulose

CASE REPORT

We report on the clinical course of a 40-year-old patient with an oral manifestation of miliary tuberculosis. In addition to oral mucosa and lung, the colon and ileum were also infested. The oral lesions may resemble malignant tumors and are difficult to diagnose, especially because tuberculosis has become a rare disease in industrialized countries.

DISCUSSION

Oral lesions and concomitant pulmonary complaints can be a sign for existing tuberculosis. Patients with these problems should undergo a chest X-ray and a biopsy from the oral mucosa. In addition, tests should be conducted to determine if mycobacteria are present in the sputum, gastric fluid, and urine and cultures grown. In cases with negative results PCR may detect DNA of Mycobacterium tuberculosis.