<prompt> Dental caries is caused by-Streptococcus pyogenesStreptococcus mutansEnterococcusH. influenzae  <response>: Ans. is b i.e., Streptococcus mutans o Streptococcus mutans belongs to viridans streptococci and is an important cause of dental cariesMedically important streptococci and their characteristicsSpecies or common nameLancefield groupHemolysisHabitat in human hostsLaboratory testCommon diseases causedStr. PyogenesAbetaThroat, skinBacitracin sensitive; PYR test positive; Ribose not fermentedUpper respiratory tract infection; pyoderma; rheumatic fever; glomerulonephritisStr. agalactiaeBbetaFemale genital tract, rectumCAMP test, hippurate hydrolysisNeonatal menigitis, septicemiaStr. equisimilisCbetaThroatRibose and trehalose fermentationPharyngitis,endocarditisStr. cinginosusA,C,F,G untypablebeta alpha, gammaThroat colon female genital tractGroup A strains bacitracin resistant PYR negative; Minute colony variants of other groupsPyogenic infectionsEnterococcus sp. Str. faecalis and other enterococciDGamma alpha, betaColonGrowth in 6.5 NaCI; PYR positive Urinary tract infections, endocarditis, Nonenterococcal Group D species Str. bovisDGammaColonNo growth in 6.5 NaCISuppurative infections EndocarditisViridanssteptococci many speciesNo typedalphagammaMouth colon, female genital tractOptochin resistant Species classification on biochemical propertiesEndocarditis Str. saneuis; dental caries Str. mutans 