Bacterial Flora Of Oral Cavity Research Articles

Comparative study on bacterial flora of oral cavity of smokers and non-smokers

The oral cavity is a complex heterogeneous microbial habitat. The presence of nutrients, saliva and epithelial debris make the mouth favorable habitat for great variety of bacteria. Cigarette smoking is a public health problem. It decreases the commensal population of oral cavity resulting in an increase of pathogenic microbes. The study was designed to compare the bacterial flora of oral cavity of smokers and non-smokers and their antibiotic sensitivity pattern. Twelve individuals comprising of 6 smokers and 6 nonsmokers were enrolled for the study. Oral swabs were collected from the oral cavity using sterile cotton swab stick under standard aseptic methods. The specimens were subjected to microscopy and culture. Organisms were identified using standard microbiological techniques. Only Gram positive bacteria were isolated from oral cavity of both smokers and non-smokers. Higher rates of bacteria were isolated from oral cavity of non-smokers (55%) than smokers (45%). Streptococcus species were found to be prevalent in both smokers and non-smokers. Streptococcus mutans (28.57%) and Streptococcus salivarius (28.57%) was found to be the most dominant bacteria in smokers. While Staphylococcus epidermidis (33.33%) was found to be most prevalent bacteria among non-smokers. Our study suggests that smoking may have altered bacterial acquisition. The study also showed the prevalence of potential pathogens and lesser number of commensals in oral cavity of smokers. The presence of potential pathogens may lead to greater susceptibility to oral as well as respiratory infections. Antibiotic susceptibility test showed higher resistivity of bacteria isolated from oral cavity of smokers towards commonly used antibiotics in comparison to non-smokers. This study suggests that campaign against smoking should be intensified and more people should be aware about the effect of smoking on oral microbiome and related diseases.

The Effect of Nonsurgical Periodontal Therapy on HNP1-3 Level in Gingival Crevicular Fluid of Chronic Periodontitis Patients

The rich bacterial flora of oral cavity is controlled by innate immune response, including antibacterial peptides and among them human neutrophil peptides 1–3 (HNP1-3). The knowledge of the involvement of HNPs in innate and acquired immunity of the periodontium is fragmentary. The aim of the study was to assess alterations in HNP1-3 levels in the gingival crevicular fluid (GCF) of chronic periodontitis patients before and after nonsurgical periodontal therapy. Nineteen patients with chronic periodontitis were qualified to the study. After periodontal examination, one site with pocket depth (PD) ≥4 mm was selected. All the patients received periodontal treatment involving scaling and root planing with additional systemic antibiotic therapy (Amoxicillin 375 mg three times daily and Metronidazole 250 mg three times daily for 7 days). Prior to therapy, 3 and 6 months after it, clinical periodontal parameters were measured and GCF was collected from previously chosen site. The level of HNP1-3 in GCF was determined by means of a commercially available enzyme-linked immunoassay kit. The periodontal therapy caused a statistically significant (p < 0.001) decrease in all the assessed clinical parameters at the sites of sample collection except for bleeding on probing. The level of HNP1-3 per measure point showed a statistically significant increase (baseline—3 months: p = 0.05, baseline—6 months: p = 0.007). Within the limits of the study, it can be stated that nonsurgical periodontal therapy with additional systemic administration of Amoxicillin and Metronidazole increases the level of HNP1-3 in GCF.

Relationship of consequences of anastomotic insufficiency and bacterial flora of oral cavity in patients with esophageal and cardia cancer

In the course of anastomotic insufficiency following resection of esophageal cancers the bacterial compound of the esophageal substance has a remarkable, presumable role in the outcome of complications. The purpose of this study is to compare the consequences of the anastomotic leak with the bacterial flora of patients' oral cavity. In this prospective study a total of 131 patients were investigated directly before the surgical intervention taking a bacterial sample. Bacterial flora of patients' oral cavity was analysed; and the correlation between the consequences of the anastomotic leak and the content of the bacterial flora was examined. Pathogenic bacteria in the oral microflora in 50 cases (38.2%) was found. Statistically significant, moderate correlation was found between the severity of the complication and the incidence of pathogenic bacteria (rs = 0.553; p≤0.05). Pathogenic agent in the microbial flora might induce higher risk and more severe outcome in case of anastomotic leakage and it might be evaluated as a determinative factor. Consideration of the bacterial flora of the oral cavity requires more attention in the preoperative preparation than before and it demands the change of the current practice. Orv. Hetil., 2017, 158(1), 25-30.

The identification of bacterial flora in oral cavity of snakes

Snakebites are a great public health concern in tropical and subtropical countries. It cannot only cause poisoning but also yield some infections in victims. There are some pathogenic agents in snake’s oral flora. This study was carried out to determine bacterial agents existing in the oral cavity of venomous and non-venomous snakes in Kashan, Iran. Using sterile swabs, the samples were obtained in two stages from the oral cavity of 11 venomous and non-venomous snakes before feeding and 3 weeks later. Then, they were cultured on Mac Conkey blood agar mediums. Gram staining of all samples was performed. Appropriate mediums and tests were fulfilled to determine gram-positive and gram-negative bacteria. The highest rate of infection belonged to coagulase-negative Staphylococcus (34.5 %) and the lowest rate was for Pseudomonas (3.1 %). Salmonella (18.8 %); Escherichia and Providencia (each 12.5 %); and Proteus, Enterococcus, and Bacillus (each 6.2 %) were other contributing pathogens found in snakes oral cavity. The obtained findings demonstrated significant bacterial pathogens in oral cavity of venomous and non-venomous snakes. Therefore, not only anti-venom treatment but also, due the probability of infections, the diagnosis and treatment should be considered in victims.

Defining the Normal Bacterial Flora of the Oral Cavity

More than 700 bacterial species or phylotypes, of which over 50% have not been cultivated, have been detected in the oral cavity. Our purposes were (i) to utilize culture-independent molecular techniques to extend our knowledge on the breadth of bacterial diversity in the healthy human oral cavity, including not-yet-cultivated bacteria species, and (ii) to determine the site and subject specificity of bacterial colonization. Nine sites from five clinically healthy subjects were analyzed. Sites included tongue dorsum, lateral sides of tongue, buccal epithelium, hard palate, soft palate, supragingival plaque of tooth surfaces, subgingival plaque, maxillary anterior vestibule, and tonsils. 16S rRNA genes from sample DNA were amplified, cloned, and transformed into Escherichia coli. Sequences of 16S rRNA genes were used to determine species identity or closest relatives. In 2,589 clones, 141 predominant species were detected, of which over 60% have not been cultivated. Thirteen new phylotypes were identified. Species common to all sites belonged to the genera Gemella, Granulicatella, Streptococcus, and Veillonella. While some species were subject specific and detected in most sites, other species were site specific. Most sites possessed 20 to 30 different predominant species, and the number of predominant species from all nine sites per individual ranged from 34 to 72. Species typically associated with periodontitis and caries were not detected. There is a distinctive predominant bacterial flora of the healthy oral cavity that is highly diverse and site and subject specific. It is important to fully define the human microflora of the healthy oral cavity before we can understand the role of bacteria in oral disease.