10.22376/ijpbs.2019.10.1.p1-12 Volume 8 Issue 2 2017 (April - June) Most species of lessThan i greaterThan Streptococcus viridians lessThan /i greaterThan group bacteria are part of normal flora that are found in different tracts such as respiratory,gastrointestinal and urogenital regions of human body.Since discrimination between species of lessThan i greaterThan Viridians Streptococci lessThan /i greaterThan group ( lessThan i greaterThan VGS lessThan /i greaterThan ) remains difficult, patient management in identifying the target bacteria was unclear. Moreover dental history is overlooked during many hospital medical evaluations, which can be a clue for diagnosing the underlying pathogen and its virulence. Transient bacteremia and subsequent hematogenous seeding of lessThan i greaterThan VGS lessThan /i greaterThan bacteria after dental procedures should be suspected on patient's immune status, medical, dental and social history. lessThan i greaterThan Viridians Streptococci lessThan /i greaterThan group of organisms has become more virulent showing increased resistance compared to last decades. lessThan i greaterThan Viridians streptococci lessThan /i greaterThan isolated from in clinical samples often is considered a contamination and therefore many seems to be present in routine diagnostic practices and therefore they have been underestimated of the clinical importance of infections caused by lessThan i greaterThan Viridians streptococci lessThan /i greaterThan . They are considered as contaminants when isolated from blood cultures in routine sampling. One of this group gained special attention, the lessThan i greaterThan Streptococcus mutants lessThan /i greaterThan for its pathogenecity of causing dental caries, various other diseases such as infective endocarditis, Bacteremia, toxic shock – like syndrome (ie., also called VSSS ( lessThan i greaterThan viridians streptococcal lessThan /i greaterThan syndrome that causes characteristic hypotension and acute respiratory disease syndrome (ARDS). lessThan i greaterThan Streptococci lessThan /i greaterThan readily colonize mucosal tissues in genitourinary, gastrointestinal, respiratory, naropharynx and skin. Most pathogens are opportunistic and part of them is colonizers that are attributed to spectrum of proteins expressed in their surfaces. These adherins interact with extracellular matrix components, host cells, other microbes, serum and saliva. This is the essential step to colonization and later invasion of host tissues. This review is given to brief the picture of lessThan i greaterThan Viridians lessThan /i greaterThan group of lessThan i greaterThan Streptococci lessThan /i greaterThan organisms. Interestingly multi-resistant lessThan i greaterThan Viridians Streptococcal lessThan /i greaterThan colonization reported neonatal sepsis, which shows increased on mechanical ventilation with increased frequency of producing nosocomial infections and ventilation associated phenomena. DR. PRIYADHARSHINI M.D.S, DR.M.MOHAMED NASSAR M.D.S AND DR. SOWMIYA MURALI Ph.D Viridans Streptococci, acute respiratory disease syndrome, Viridians Streptococci group Colonization,Oral infections 20-26