Role of Streptococci as etiological agents of dental caries

Abstract

Dental plaques are notorious and lead to dental caries responsible for dental decay. Streptococci are the leading microorganisms associated with dental plaques. These are Gram-positive, normal microbial flora, nonmotile, non-spore forming, and facultative anaerobes. These include Alpha, Beta, and Gamma hemolytic species. Streptococcus sp. produces a high amount of lactic acid through the fermentation of sugars, causes lowering of the pH leading to the plaque formation around teeth, and serves as a biofilm. Microbial biofilm provides certain attachment sites for growth and colonization of other bacteria, and also causes resistance to the antimicrobial agents. These Streptococci can be transmitted to the infants through parents or caretakers' kiss. This mode of transmission is the key role for the contribution of S. mutans in dental caries. In Pakistan, a national survey was conducted in 1992 on tooth decay, which showed that two teeth per person were decayed, missing, or filled, thus becomes an alarming situation. Minimal knowledge related to tooth decay is observed in the clinical settings; however, no similar studies have been carried out in Pakistan.

Antagonistic Activity of Bacteria Isolated from the Periplaneta americana L. Gut against Some Multidrug-Resistant Human Pathogens

“…Among this multidrug-resistant (MDR) diversity, bacteria such as Enterobacter cloacae have emerged as a significant nosocomial pathogen in neonatal units, with numerous outbreaks of infection being reported [ 22 , 23 ]; Salmonella enterica , associated with typhoid and paratyphoid fever [ 24 ]; Staphylococcus aureus , a natural inhabitant of human and animal skin but sometimes able to cause infections affecting many organs and also incriminated in food poisoning [ 25 ]; Streptococcus mutans , the main contributor to tooth decay and oral infections [ 26 ]. These are all species that have become difficult to treat with conventional antibiotics [ 27 ]. On the other hand, there are pathogenic fungi that are among species that can resist a wide range of anti-fungal drugs [ 28 ]: Aspergillus flavus , which produces aflatoxin B1, the most toxic and potent hepatocarcinogenic natural compound ever found [ 29 ]; A. fumigatus , a species incriminated in a wide range of diseases including chronic pulmonary aspergillosis [ 30 ]; A. niger , known to produce mycotoxins called ochratoxins [ 31 ]; Candida albicans , which initiates a wide range of diseases such as chronic disseminated candidiasis, endocarditis, vaginitis, meningitis, and endophthalmitis [ 32 ]; Penicillium italicum , attributed to the pathogenesis of pneumonia, hypersensitivity, allergic alveoli, skin sensitivity, and emphysema [ 33 ].…”

A comparative study of the antimicrobial activity of cacao ethanol extract and chlorhexidine digluconate on salivary Streptococcus mutans

“…S. mutans activity in tooth decay is that, it mainly transform sucrose by using glucan sucrase enzyme to lactic acid (5) . Moreover, large amount of acid and extracellular polysaccharides are produced due to the bacterial colonization that benefit plaque formation (6) .…”