Candida colonisation of the oral cavity increases in immunocompromised individuals which leads to the development of oral candidiasis. In addition, host factors such as xerostomia, smoking, oral prostheses, dental caries, diabetes and cancer treatment accelerate the disease process. Candida albicans is the primary causative agent of this infection, owing to its ability to form biofilm and hyphae and to produce hydrolytic enzymes and candialysin. Although mucosal immunity is activated, from the time hyphae-associated toxin is formed by the colonising C. albicans cells, an increased number and virulence of this pathogenic organism collectively leads to infection. Prevention of the development of infection can be achieved by addressing the host physiological factors and habits. For maintenance of oral health, conventional oral hygiene products containing antimicrobial compounds, essential oils and phytochemicals can be considered, these products can maintain the low number of Candida in the oral cavity and reduce their virulence. Vulnerable patients should be educated in order to increase compliance.

Purpose The aim of this study was to identify β-lactamase-producing oral anaerobic bacteria and screen them for the presence of cfxA and BlaTEM genes that are responsible for β-lactamase production and resistance to β-lactam antibiotics. Material and Methods Periodontal pocket debris samples were collected from 48 patients with chronic periodontitis and anaerobically cultured on blood agar plates with and without β-lactam antibiotics. Presumptive β-lactamase-producing isolates were evaluated for definite β-lactamase production using the nitrocefin slide method and identified using the API Rapid 32A system. Antimicrobial susceptibility was performed using disc diffusion and microbroth dilution tests as described by CLSI Methods. Isolates were screened for the presence of the β-lactamase-TEM (BlaTEM) and β-lactamase-cfxA genes using Polymerase Chain Reaction (PCR). Amplified PCR products were sequenced and the cfxA gene was characterized using Genbank databases. Results Seventy five percent of patients carried two species of β-lactamase-producing anaerobic bacteria that comprised 9.4% of the total number of cultivable bacteria. Fifty one percent of β-lactamase-producing strains mainly Prevotella, Porphyromonas, and Bacteroides carried the cfxA gene, whereas none of them carried blaTEM. Further characterization of the cfxA gene showed that 76.7% of these strains carried the cfxA2 gene, 14% carried cfxA3, and 9.3% carried cfxA6. The cfxA6 gene was present in three Prevotella spp. and in one Porphyromonas spp. Strains containing cfxA genes (56%) were resistant to the β-lactam antibiotics. Conclusion This study indicates that there is a high prevalence of the cfxA gene in β-lactamase-producing anaerobic oral bacteria, which may lead to drug resistance and treatment failure.

Dental caries, caused by Streptococcus mutans, is a common infection. Caries vaccine has been under investigation for the last 40 years. Many in vitro and in vivo studies and some human clinical trials have determined many pertinent aspects regarding vaccine development. The virulence determinants of S. mutans, such as Ag I/II, responsible for adherence to surfaces, glucosyltransferase (GTF), responsible for the production of glucan, and the glucan binding protein (GBP), responsible for the attachment of glucan to surfaces, have been known to elicit an antigen‐specific immune response. It is also known that more than one antigen or a functional part of the genome responsible for these virulence determinants provide a better host response compared with the monogenic vaccine or complete genome of a specific antigen. To enhance the host response, the use of adjuvants has been studied and the routes of antigen administration have been investigated. In recent years, some promising vaccines such as pGJA‐P/VAX, LT derivative/Pi_39‐512, KFD2‐rPAc and SBR/GBR‐CMV‐nirB have been developed and tested in animals. New virulence targets need to be explored. Multicentre collaborative studies and human clinical trials are required and some interest from funders and public health experts should be generated to overcome this hurdle.