Detection Of Streptococcus Mutans Research Articles

Detection of Streptococcus Mutans in Saliva Using PCR Technique

The purpose of this paper was to detect Streptococcus mutans in saliva in a group of students of the Faculty of Natural Sciences through the PCR technique. The oral cavity is a dynamic environment that undergoes large and rapid fluctuations in pH, nutrient source and availability, oxygen tension, temperature, and osmolality. The ability of Streptococcus mutans to survive in such an environment is attributed to its ability to produce acids as well as glucans from carbohydrates, implicating it in the etiology and progression of dental caries. Detection of Streptococcus mutans using rapid, sensitive and specific methods is very important for early diagnosis and effective assessment of an individual's risk for dental caries. In this study, 30 students, aged 18-20, participated voluntarily, where the average age is 19.07 years, with a standard deviation of 0.57. From analyzing the saliva samples, we found that 86.7% (26/30), SE =0.033, 95%CI (83.7%-89.7%), of them were positive for S. mutans. From the analysis of the χ2 test to see the relationship between the variables taken in the study and the presence of S. mutans, we did not find reliable relationships. PCR, as a molecular biology method, proved to be quite efficient, sensitive and rapid for the detection of Streptococcus mutans from saliva.

Rapid Detection of Streptococcus mutans Using an Integrated Microfluidic System with Loop-Mediated Isothermal Amplification.

Streptococcus mutans is the primary causative agent of caries, which is one of the most common human diseases. Thus, rapid and early detection of cariogenic bacteria is critical for its prevention. This study investigated the combination of loop-mediated isothermal amplification (LAMP) and microfluid technology to quantitatively detect S. mutans. A low-cost, rapid microfluidic chip using LAMP technology was developed to amplify and detect bacteria at 2.2-2.2 × 106 colony-forming units (CFU)/ml and its detection limits were compared to those of standard polymerase chain reaction. A visualization system was established to quantitatively determine the experimental results, and a functional relationship between the bacterial concentration and quantitative results was established. The detection limit of S. mutans using this microfluidic chip was 2.2 CFU/ml, which was lower than that of the standard approach. After quantification, the experimental results showed a good linear relationship with the concentration of S. mutans, thereby confirming the effectiveness and accuracy of the custom-made integrated LAMP microfluidic system for the detection of S. mutans. The microfluidic system described herein may represent a promising simple detection method for the specific and rapid testing of individuals at risk of caries.

Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6-18-month-old Infants.

To determine the presence of Streptococcus mutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) and their association with extrinsic and intrinsic variables in 6-18-month-old infants. This was an analytical, cross-sectional study of 65 6-18-month-old infants who visited the Centers for Early Childhood in Buenos Aires City. Three groups were established according to the presence of teeth-group I (GI)-edentulous infants, group II (GII)-infants with 1-8 teeth, and group III (GIII)-infants with 9-16 teeth. Data on the variables, diet, use of artificial teats, and oral hygiene were gathered using a self-administered questionnaire. An oral examination was performed according to the International Caries Detection and Assessment System (ICDAS II) criterion. A saliva sample was taken by aspiration with a sterile plastic syringe. Cariogenic Streptococci (CS) were counted using the adherence test in modified gold broth (AT-MGB). Molecular detection and quantification were performed by quantitative polymerase chain reaction (qPCR) (gtfB, gtfT, and tuf). A total of 12% of infants received oral hygiene, 38% used bottles, 30% used pacifiers, and 55% had sugar intake. S. sobrinus and S. mutans were detected in 57.1 and 28.6% of the children with caries, respectively. Groups I, II, and III had CS counts of log 2, 3.4, and 3.7, respectively. S. sobrinus was detected in 26.7% of GI, 52.9% of GII, and 85.7% of GIII, while S. mutans was detected in 13.3%, 35.3%, and 57.7%, respectively. The prevalence of S. sobrinus was higher than S. mutans in all groups. The presence of CS was significantly associated with sugar intake. No association was found between S. mutans and S. sobrinus and the presence of caries, hygiene habits, or use of artificial teats. This study supports the role of diet in developing a cariogenic biofilm in children under 2 years of age. Cornejo CF, Soken LJ, Salgado PA, et al. Detection of Streptococcus mutans and Streptococcus sobrinus and Their Association with Oral Microbiome Stressors in 6-18-month-old Infants. Int J Clin Pediatr Dent 2023;16(1):68-73.

Molecular Detection of Streptococcus mutans and Streptococcus sobrinus in Dental Plaque Samples in Children Aged Six to Nine Years.

Context Dental caries is a widespread threat, usually in children, although it has been observed at other stages of life. Various pieces of literature have confirmed the prevalence of S treptococcus mutans and S treptococcus sobrinus in the progression of the disease. However, establishing procedures to detect these species remains a challenge, posing a barrier to treatment plans. Aim The aim of this study is to detect the species in dental plaque samples from children aged six to nine years by polymerase chain reaction (PCR) and correlate their prevalence in various dentitions. Material andMethods This is an observational analytical cross-sectional study conducted in a tertiary care dental hospital. After sample isolation, microbiological processing was performed, genomic DNA was isolated, and PCR run was performed using specific primers to detect the species. SPSS for Windows Version 17 (IBM Corp., Armonk, NY) and Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) were used to perform statistical analysis. A p-value of <0.05 was considered statistically significant. Results The technique could identify S. Mutans and S. Sobrinus in a short turnaround time. The frequency of S. mutans and S. sobrinus infections was higher in individuals with dental caries. Conclusions Molecular detection via PCR is a reliable, economical, and less time-consuming method for detecting S. mutans and S. sobrinus in dental plaque samples.

Detection of Streptococcus Mutans and Streptococcus sobrinus by Polymerase Chain Reaction (PCR) in Saliva Samples

Background: Dental caries has been a major problem in Bangladesh for decades. Oral diseases are the most common non-communicable diseases related to severe local and systemic disorders. Oral microorganisms can grow and spread in the oral mucosae and most commonly in biomaterials under polymicrobial biofilms, leading to several diseases such as dental caries and periodontal disorders. Aims: This study aimed to detect S. mutants and S. sobrinus by polymerase chain reaction (PCR) amplification and to relate the link between their presence and dental caries.&#x0D; Materials and Methods: Streptococcusmutans (S. mutans) and Streptococcus sobrinus (S. sobrinus) strains were isolated from individuals with no caries. However, they were isolated with high counts of those organisms in saliva samples. The saliva samples were collected from the patients who attended the outdoor Dhaka Dental College Hospital from March 2018 to December 2018. PCR was performed to detect the presence of different organisms.&#x0D; Results: Prevalence of S. mutans and S. sobrinus was, respectively, 19% and 04%. About 68% of the saliva sample was not either positive for both bacterial species, whereas 09% was positive for both bacterial species.&#x0D; Conclusion: This study demonstrated that PCR is an easy, quick, and reliable method for detecting S. mutans and S. sobrinus in epidemiological studies. It was also observed that S. mutans was the most common organism than S. sobrinus to develop caries.&#x0D; TAJ 2022; 35: No-1: 07-10

Polymorphism in Vitamin D Receptor Gene and Their Relation to Streptococcus mutans in Deciduous Teeth Decay among Egyptian Children

Background: Multiple factors play a role in the dental decay occurrence, including microorganisms, diet, oral hygiene, medical conditions, and lack of important nutrients, such as vitamin D. Objectives: correlation between VDR gene and Streptococcus mutans count in children deciduous teeth decay. Methodology: Cross sectional study from January 2018 till January 2019. One hundred and fifty children were involved and divided into two groups; group I: 75 patients with deciduous tooth decay; and group II: 75 children free from dental caries as a control group. Saliva sample for Streptococcus mutans detection and buccal cells sample for vitamin D receptor gene polymorphism (VDR) assay were taken from each patient. Results: S. mutans count was higher in cases than control group and showed statistically significant difference (p=0.0002). Frequency of GG genotype was higher in control (86.7%) than cases group (64.0%) while GT genotype was higher in cases (36.0%) than control group (13.3%). Risk ratio of GT/GG in cases vs control was significant (p=0.001). Conclusions: GT genotype supports the growth of some bacteria in the oral cavity. S. mutans count was higher in GT genotype, so people with GT genotype are more susceptible to develop dental caries by 3.65-fold and suffer from more DMFT. Susceptibility people should increase care of mouth hygiene.

The Effect of Solutions Containing Extracts of Vochysia tucanorum Mart., Myrcia bellaCambess., Matricaria chamomilla L. and Malva sylvestris L. on Cariogenic Bacterial Species and Enamel Caries Development

This study evaluated the effect of experimental solutions containing plant extracts on bacterial species and enamel caries prevention. Microcosm biofilm was produced from human saliva mixed with McBain saliva (0.2% sucrose) on bovine enamel for 5 days (3 days under anaerobiosis and 2 days under aerobiosis) at 37°C. From the 2nd day, the following treatments were applied (1 × 60 s/day): Vochysia tucanorum (10 mg/mL); Myrcia bella (5 mg/mL); Matricaria chamomilla (80 mg/mL); Malva sylvestris, fluoride, and xylitol (Malvatricin Plus®); 0.12% chlorhexidine (CHX, PerioGard®); and PBS (negative control). The medium pH was measured. Quantitative polymerase chain reaction was performed for the detection of Streptococcus mutans and Lactobacillus spp. Enamel demineralization was measured by spectral-domain optical coherence tomography. The data were compared by means of the Kruskal-Wallis/Dunn, two-way ANOVA/Bonferroni, and ANOVA/Tukey tests (p < 0.05). The pH decreased after sucrose exposure; only CHX reestablished pH >5.5 by the last day. CHX also eliminated Lactobacillusspp., but the other treatments did not differ significantly from PBS. Malvatricin Plus® and CHX eliminated S. mutans, but the other treatments did not differ from PBS. Similar results were seen concerning the reduction of lesion depth and reflectivity. The experimental natural-extract solutions were ineffective against cariogenic bacteria and in preventing the development of enamel caries.

Detection of Streptococcus mutans in symptomatic and asymptomatic infected root canals.

To investigate the presence of Streptococcus mutans in root canals of symptomatic necrotic teeth (SNT) and their associated acute apical abscesses (AAA) and in the root canals of asymptomatic necrotic teeth (ANT). It also aimed to investigate the presence of the cnm and cbm genes in specimens that harbored S. mutans. DNA was extracted from samples collected from 10 patients presenting pulpal necrosis associated with radiographic evidence of apical periodontitis (ANT) and from 10 patients in need of endodontic therapy due to the presence of pulpal necrosis (SNT) and AAA. The control group consisted of 10 patients with teeth with normal vital pulp and requiring endodontic treatment for prosthetic reasons. The presence of S. mutans was detected by quantitative real-time-PCR (qPCR) using species-specific primers. Samples harboring S. mutans were further evaluated for the presence of CBP genes by qPCR as well. All studied sites showed a high prevalence of S. mutans, except the control group. Specifically, 60% of ANT and 70% of AAA/SNT paired samples were positive for S. mutans. The cnm gene was detected positive for S. mutans only in ANT samples (66.6%). The cbm gene was not detected in any of the investigated sites. S. mutans was found in high prevalence in both asymptomatic and symptomatic endodontic infections, including in abscesses, but it was not detected in the root canals of teeth with normal vital pulp. Interestingly, cnm+ S. mutans was only detected in asymptomatic/chronic primary endodontic infections associated with apical lesion. Therefore, it appears that cnm, and possibly other CBPs, may play an underestimated role in chronic endodontic infections. A high prevalence of Streptococcus mutans cnm+ gene was detected only in asymptomatic primary endodontic infections associated with apical lesion. Therefore, it appears that this collagen-binding protein gene plays an underestimated role in asymptomatic/chronic endodontic infections.

Rapid detection of the Streptococcus mutans cnm gene by loop-mediated isothermal amplification.

This study investigated a method using loop-mediated isothermal amplification (LAMP) for the rapid detection of cnm-positive Streptococcus mutans (S. mutans) associated with cerebral microhemorrhage. LAMP amplified the cnm gene plasmid vector, but not human or microbial genomic DNA. The cnm DNA of the cnm-positive S. mutans strain was detected in saliva without DNA extraction after 1 day of culture. This method resulted in a cnm-positive rate of 26.4% in 102 samples, which was higher than that obtained with conventional PCR. In conclusion, LAMP may be used for the detection of cnm-positive S. mutans in a large number of samples.

Oral Lactobacilli Related to Caries Status of Children with Primary Dentition

Oral lactobacilli are members of a group of bacteria implicated in caries progression, although information regarding their transmission, colonization, and caries-associated species is not well established. This study isolated oral lactobacilli from a group of children with primary dentition for determination of Lactobacillus prevalence, detection of Streptococcus mutans, a major pathogen of caries initiation, and dental caries status of the children. Species of Lactobacillus isolates were determined from examination of 16S rDNA sequences. Subsequently, the most prevalent species was evaluated for involvement in caries status, and binding ability to type I collagen of all Lactobacillus isolates was determined in association with caries status. Multilocus sequence typing (MLST) of eleven loci was carried out to study strains of the predominant Lactobacillus sp. The detection of oral lactobacilli together with S. mutans was significantly associated with the highest dental caries indices, but there was no involvement of collagen-binding properties of Lactobacillus isolates in caries status. Lactobacillus fermentum was the most prevalent, and its presence was related to high scores of caries indices. MLST analysis of L. fermentum population could not specify a particular clone associated with caries status, but revealed sharing of identical L. fermentum strains among children in the same classrooms. Taken together, the data contributed useful information on the role of oral lactobacilli, in particular L. fermentum in dental caries.

Engineering DNA-Nanozyme Interfaces for Rapid Detection of Dental Bacteria.

Engineering biological interfaces represents a powerful means to improve the performance of biosensors. Here, we developed a DNA-engineered nanozyme interface for rapid and sensitive detection of dental bacteria. We employed DNA aptamer as both molecular recognition keys and adhesive substrates to functionalize the nanozyme. Utilizing different immobilization strategies and DNA designs, a range of DNA nanoscale biointerfaces were constructed to modulate enzymatic and biological properties of the nanozyme systems. These functional biointerfaces improved the accessibility of bacteria to the nanozyme surface, providing large signal change range at optimal DNA probe density. The DNA-functionalized nanozymes demonstrate a rapid, label-free, and highly sensitive direct colorimetric detection of Streptococcus mutans, with a detection limit of 12 CFU mL-1, as well as excellent discrimination from other dental bacteria. We demonstrate the use of this biological nanointerface for identifying dental bacteria in salivary samples, showing its potential in clinical prevention and diagnosis of dental diseases.

Streptococcus mutans detection in saliva and colostrum samples

ABSTRACTObjective To detect Streptococcus mutans in colostrum and saliva of neonates and compare with its detection in saliva of mothers.Methods Forty-three healthy women, full-term gestations with no complications, submitted to elective Cesarean section, and their newborns were included in the study. Samples were investigated by polymerase chain reaction to detect S. mutans in genetic material from the samples.Results Approximately 16% of colostrum samples showed S. mutans , but not correlated with the presence of the bacteria in both samples of saliva. S. mutans was detected in 49 and 30% of saliva samples of mothers and neonates, respectively. There was a positive correlation in S. mutans detection between types of saliva. The number of maternal samples of saliva with detectable S. mutans was smaller in women receiving dental treatment during pregnancy. Tooth brushing, three times a day, influenced the detection of S. mutans in both the saliva and the colostrum.Conclusion Although maternal saliva may present S. mutans , few samples of colostrum present the bacteria. The presence of bacteria in neonate saliva may be related to contact before birth. Dental treatment and hygiene habits seem to influence the detection of S. mutans in samples of maternal saliva and colostrum.

The Caries Microbiome: Implications for Reversing Dysbiosis.

The oral microbiome plays a critical role in maintaining oral health. Frequent dietary carbohydrate intake can lead to dysbiosis of the microbial community from overproduction of acid with selection for increases in acidogenic, acid-tolerant bacteria. Knowledge of the caries-associated microbiome is key in planning approaches to reverse the dysbiosis to achieve health. For risk assessment and treatment studies, it would be valuable to establish whether microbial monitoring requires assay of multiple species or whether selected key species would suffice. Early investigations of the oral microbiota relied on culture-based methods to determine the major bacteria in health and disease. Microbial monitoring using gene probes facilitated study of larger populations. DNA probe methods confirmed and expanded the importance of transmission of bacteria from mother to infant and association of preselected species, including mutans streptococci and lactobacilli with caries in larger populations. 16S ribosomal RNA (rRNA) probes confirmed the wide diversity of species in oral and caries microbiomes. Open-ended techniques provide tools for discovery of new species, particularly when strain/clone identification includes gene sequence data. Anaerobic culture highlighted the caries association of Actinomyces and related species. Scardovia wiggsiae, in the Actinomyces/Bifidobacterium family, and several Actinomyces species have the cariogenic traits of acid production and acid tolerance. Next-generation sequencing combined with polymerase chain reaction methods revealed a strong association with mutans streptococci in a high caries population with poor oral hygiene and limited access to care. A population with a lower caries experience generally had lower or no Streptococcus mutans detection but harbored other acidogenic taxa in the microbiome. Study of the microbiome suggests a role for the assay of selected putative cariogenic species in more aggressive diseases. For many populations with caries progression, however, assay of multiple species will likely be warranted to determine the caries profile of the population and/or individuals under study.

Comparative study on efficacy of advanced and conventional methods used for detection of Streptococcus mutans in saliva of dental caries patients

Comparative study on efficacy of advanced and conventional methods used for detection of Streptococcus mutans in saliva of dental caries patients

Specific chemiluminescent protocol for dual-site recognition of Streptococcus mutans utilizing strong affinity between teicoplanin and Gram-positive bacteria

A novel dual-site recognition protocol was developed for chemiluminescent (CL) detection of Streptococcus mutans (S. mutans) based on a designed antibiotic-affinity strategy. Teicoplanin, a broad-spectrum antibiotic against Gram-positive bacteria, was adopted to functionalize magnetic particles and recognize S. mutans utilizing the strong affinity between this agent and D-Alanyl-D-Alanine peptide moieties in the bacterial cell wall. To achieve ideal specificity for S. mutans detection, rat immunoglobulin G2a (rat IgG2a) tagged with horseradish peroxidase (HRP) was used as the second recognition agent and signal tracer since Fab region of rat IgG2a could bind with streptococcal protein G highly expressed in the cell wall of S. mutans. Thus HRP-tagged sandwich complex of teicoplanin/S. mutans/rat IgG2a was formed on the magnetic particles, followed by a CL quantification of S. mutans based on a HRP-catalyzed luminol-H2O2-p-iodophenol CL reaction. This dual-site recognition protocol showed a linear range of 1.0 × 102–1.0 × 106 CFU mL−1 and a detection limit of 33 CFU mL−1 for S. mutans detection. The whole detection process could be completed within 70min. The recovery tests for food, environmental, pharmaceutical and biological samples showed acceptable recovery values between 83.0% and 110.0%, demonstrating its application potential for detection of bacteria in various sample matrixes.

A sandwich protocol for chemiluminescent detection of Streptococcus mutans utilizing dual-site recognition by rat IgG2a and vancomycin

A sandwich protocol was developed for chemiluminescent detection of Streptococcus mutans (S. mutans) utilizing dual-site recognition of the bacteria by rat IgG2a and vancomycin. Magnetic particles (MPs) functionalized with rat IgG2a were adopted to capture S. mutans based on the binding between Fc region of rat IgG2a and protein G in the cell wall of the bacteria. Alkaline phosphatase labeled vancomycin was applied as the signal tracer since D-Ala-d-Ala peptide moieties in the cell wall of Gram-positive bacteria could be recognized by this antibiotic agent. The protocol showed an ideal specificity for S. mutans detection because the recognition agents bound with the bacteria at two distinct sites. Furthermore, the utilization of MPs enrichment greatly improved the sensitivity. S. mutans could be detected within a linear range of 2.4×101 − 2.4×105 CFU mL−1, with a very low detection limit of 2.3×101 CFU mL−1. Some common Gram-positive bacteria and Gram-negative bacteria showed negligible interference. This proposed method for S. mutans detection possessed some attractive characteristics such as facile manipulation, short detection time, low cost, ultra-high sensitivity and ideal specificity. It was used to detect S. mutans in human saliva with acceptable recoveries ranging from 70.8% to 108.3%.

Correlation between dental caries experience and mutans streptococci counts by microbial and molecular (polymerase chain reaction) assay using saliva as microbial risk indicator.

The aim of this study was to assess the relationships of quantitative salivary levels of mutans streptococci (MS) in children, aged 3-6 years and 12-15 years, exhibiting variable patterns of caries activity, and to compare the association of MS in saliva using microbial and molecular (polymerase chain reaction [PCR]) assay. In this cross-sectional observational study, eighty children were included, forty children each in Group I (3-6 years) and Group II (12-15 years). Children were further divided into two subgroups (Group IC, INC and Group IIC, IINC) based on their dental caries status. Saliva samples were collected and plated onto Mitis Salivarius-Bacitracin agar plates. After detection of MS, DNA was isolated and purified, and MS were evaluated using the PCR and AP-PCR. Of the selected 80 children, 42 were male and 38 were female. In Group IC, the mean colony count was 2.27 ± 0.54 × 105 CFU/ml, and in Group INC, the mean colony was found to be 1.61 ± 0.54 × 105 CFU/ml. In Group II, where mean colony count of 3.31 ± 0.85 × 105 CFU/ml and 2.44 ± 0.54 × 105 CFU/ml was observed in Group IIC and Group IINC, respectively. The mean colony count increased with increasing age and was also more in children with dental caries. Based on the matrices generated by the PCR analysis using coefficient slipped-strand mispairing, wide range of genetic diversity was seen in cases of children with and without clinically detectable caries.

Investigation of the oral status and microorganisms in children with phenylketonuria and type 1 diabetes.

The aim of this study was to investigate the oral parameters that influence the caries risk and risk of developing periodontal disease in children with phenylketonuria (PKU) and type 1 diabetes compared to healthy children. Two hundred and thirty-eight children between the ages of 3 and 18years were recruited in the PKU, diabetes and healthy group. The decayed, missing and filled surfaces (dmfs/DMFS) index, papillary bleeding index (PBI) and the Silness & Löe Index were assessed. Quantitative real-time polymerase chain reaction (PCR) was used for the detection of Streptococcus mutans (Sm), Lactobacillus casei (Lca), Lactobacillus species (Lac), Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg) and Tannerella forsythensis (Tf). A statistically significant difference in the dmfs index value was found between the three groups. The mean dmfs index value for the PKU children (4.18) was found to be relatively high. Comparing the three groups, diabetics showed statistically significant higher values for the Silness and Löe Index. Comparing the diabetics to just the healthy children, the diabetics revealed a small statistically significant difference in the PBI score. A statistically significant difference was found between Lac, Lca and Pg in the three groups. Counts of Lac were the lowest in the PKU children. The diabetics showed the highest counts of Lca but lowest for Pg. Comparing the three groups, children with PKU revealed a higher caries experience in their primary dentition. While the diabetic children showed a lower one in their primary dentition, they were found to possess a slightly higher risk of developing periodontal disease. It is proposed that both groups of child patients be encouraged to seek early dental advice and be incorporated in a meticulous prevention programme.

Detection of Streptococcus mutans using padlock probe based on Rolling Circle Amplification (RCA)

The aim of this study was to develop and evaluate a padlock probe based on the Rolling Circle Amplification (RCA), which targeted to 16S-23S rDNA region of S. mutans. The specificity of developed padlock probe was tested for DNA within a panel strains, including S. mutans isolated from the saliva and reference strains of the genus Streptococcus, as well as total DNA samples of biofilm and saliva. The results were positive either for DNA samples of S. mutans or DNA samples recovered from the biofilm and saliva revealing the specificity of designed padlock probe. The padlock probe based on the RCA was proved to be an effective, reproducible method for S. mutansdetection and demonstrated the possibility of a rapid detection and accurate identification of S. mutans infection.

Lack of Association between Halitosis and the Presence of Streptococcus mutans in Saliva

Background: Streptococcus mutans is a Gram-positive bacteria which plays a major role in tooth decay. S. mutans is among the bacterial agents that initiate biofilm formation on the tooth surface and other bacteria will added then to the attached bacteria to make dental plaque. Some of these secondary bacteria are important agents in halitosis Objectives: To compare the presence of Streptococcus mutans in saliva of patients with halitosis and control group, using culture method. Materials and Methods: Saliva specimens of 100 patients referring to diagnosis ward of Shiraz Original Research Article Ghapanchi et al.; BJMMR, 10(3): 1-7, 2015; Article no.BJMMR.19571 2 medical school were collected. 51 patients (34 female and 17 male) complaining of halitosis were considered as study group and 49 patients (31 female and 18 male) without halitosis as control group. All specimens were cultured on MSB agar media and isolates were identified as S. mutans by traditional tests. The number of S. mutans was determined as cfu/ml in each patient saliva. An organoleptic evaluation was carried out during the initial consultation with the distance of operator to patient (1 m =grade 3) and (30 cm =grade 2 and 10 cm =grade 1). Results: Of 51 patients with halitosis in 11 (21.61%) patients saliva S. mutans were detected. In 49 patients of control group, 14 subjects (28.6%) showed growth of S. mutans. There was no Statistical difference between halitosis group and control group in the frequency of Streptococcus mutans detection (OR= 0.69, 95% C.I: 0.28-1.71, p=0.419). Statistical analysis also did not show any significant difference between the number of S. mutans colonies per ml of saliva between halitosis and control groups (p=0.287). Conclusion: Our findings showed that there was no association exists between halitosis and the Streptococcus mutans presence in saliva.