Identification of "Streptococcus milleri" group isolates to the species level with a commercially available rapid test system

Abstract

Clinical isolates of the ''Streptococcus milleri'' species group were examined by conventional methods and a rapid, commercially available method for the identification of these strains to the species level. The levels of agreement between the identifications obtained with the commercially available system (Fluo-Card Milleri; KEY Scientific, Round Rock, Tex.) and conventional methods were 98% for 50 Streptococcus anginosus strains, 97% for 31 Streptococcus constellatus strains, and 88% for 17 isolates identified as Streptococcus intermedius. Patient records were also studied in order to gain information on the frequency and sites of isolation of each of the three ''S. milleri'' group species.

Species belonging to the "Streptococcus milleri" group: antimicrobial susceptibility and comparative prevalence in significant clinical specimens

“…The association between S. anginosus and gastrointestinal sources has been assessed by Whiley et al with clinical isolates from different laboratories in the United Kingdom (15). However, other authors failed to clearly demonstrate such a correlation (5,6). In agreement with other reports (1,5,15,16), our study supports the evidence that S. anginosus is more frequently isolated from the genitourinary tract than the other two species.…”

“…Those authors have also proposed a biochemical scheme for the phenotypic differentiation of these three species (16). In addition, reliable test systems are now commercially available (1,5).…”

“…Although previous studies have evaluated the clinical significance and antimicrobial susceptibility of the "S. milleri" group as a whole (9,12), relatively few studies have examined either the clinical correlation (5,6,15,16) or the antimicrobial susceptibility (6) of the three individual species as currently defined.…”

“…Numerous types of infections caused by this heterogeneous complex of streptococci have been reported (9,12), including fulminant septicemia in a previously healthy adult (4) and neonatal infection (11). In addition, several authors have recently examined the association of the three species belonging to the "S. milleri" group with different sites of the body (5,6,15,16). Like these authors, we have observed that S. anginosus was the most prevalent species (64.4%) among the three species belonging to the "S. milleri" group, and it was more frequently associated with abdominal sites than either S. constellatus or S. intermedius.…”

Different frequencies of Streptococcus anginosus infection in oral cancer and esophageal cancer

“…S. anginosus infection in cancer tissues of the upper digestive tract and the concept of field cancerization led us to consider S. anginosus to be one possible risk factor for cancer development and also led us to propose that S. anginosus infection occurs in oral cancer tissues as well as other sites in the upper digestive tract. Presently, neither the biochemical criteria nor PCR methods for identification of streptococci are sufficiently specific and reliable, because various oral Streptococci that are biochemically and phylogenetically similar to S. anginosus are dominant in the oral cavity, 15,16) and these species sometimes interfere with detection of S. anginosus. Therefore, in the present study, a quantitative, real-time PCR coupled with TaqMan chemistry, a highly sensitive and specific approach, 17) was developed to assess S. anginosus status.…”