Granulicatella

Abstract: We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair.

Abstract: One hundred one isolates of nutritionally variant streptococci from 97 patients were phenotypically characterized and compared with the type strains of Granulicatella adiacens (formerly Abiotrophia adiacens) (ATCC 49175(T)) Abiotrophia defectiva (ATCC 49176(T)), and Granulicatella elegans (formerly Abiotrophia elegans) (DSM 11693(T)). Of the isolates, 55 and 43 resembled G. adiacens and A. defectiva, respectively, while 3 strains resembled G. elegans. Phenotypic characteristics useful in differentiating between species within the genera Granulicatella and Abiotrophia (G. adiacens, G. elegans, Granulicatella balaenopterae, and A. defectiva) were production of alpha- and beta-galactosidase; production of beta-glucuronidase; hippurate hydrolysis; arginine dihydrolase activity; and acid production from trehalose, sucrose, pullulan, and tagatose. From the reports submitted with the specimens, the clinical diagnosis was endocarditis in 58% of patients and septicemia or bacteremia in 26% of patients.

Abstract: Granulicatella species, along with the genus Abiotrophia, were originally known as ‘nutritionally variant streptococci’. They are a normal component of the oral flora, but have been associated with a variety of invasive infections in man and are most noted as a cause of bacterial endocarditis. It is often advised that Granulicatella endocarditis should be treated in the same way as enterococcal endocarditis. We review here the published data concerning diagnosis and treatment of Granulicatella infection, and include some observations from local cases, including four cases of endocarditis.

Abstract: Background Abiotrophia and Granulicatella species, previously referred to as nutritionally variant streptococci (NVS), are significant causative agents of endocarditis and bacteraemia. In this study, we reviewed the clinical manifestations of infections due to A. defectiva and Granulicatella species that occurred at our institution between 1998 and 2004.