Abstract
Globicatella sanguinis is an unusual pathogen causing bacteremia, meningitis, and urinary tract infection, and can be misidentified as Streptococcus pneumoniae or viridans streptococci due to its colonial morphology. A 76-year-old female patient with hypertension and degenerative arthritis was admitted to the hospital complaining of knee joint pain. Blood culture revealed the presence of Gram-positive cocci, and the isolated organism was equally identified as S. pneumoniae using the MicroScan identification system (Beckman Coulter, USA) and Vitek 2 identification system (bioMérieux, USA). However, the isolate showed optochin resistance based on the optochin disk susceptibility test. The organism was finally confirmed to be G. sanguinis based on 16S rRNA sequencing and hydrogen sulfide production testing. Accurate identification of G. sanguinis isolated from aseptic body fluids including blood is important for appropriate antibiotic selection based on accurate application of interpretative criteria of antimicrobial susceptibility test. (Ann Clin Microbiol 2018;21:40-44)
Keywords
Bacteremia Globicatella sanguinis 16SrRNA sequencing
Figures & Tables
Fig. 1. Neighbor joining phylogenetic tree showing the relationship of our case to Globicatella species. The black dotted G. sanguinis is our isolate. Species name and accession code are given as cited in the EzBioCloud database.
Figures & Tables
Table 1. Phenotypic characteristics of our isolate identified by commercial kits and
Characteristics | Our isolate* | ||||
Previous study by | Previous study by Vandamme et al. [4] | ||||
Facklam [3]† | Shewmaker et al. [2]‡ | Collins et al. [1] | |||
Leucine aminopeptidase | ND | − | − | ND | ND |
Pyrrolidonylarylamidase | ND | V | V | + | − |
Growth in 6.5% NaCl | − | + | + | ND | + |
Bile-esculin reaction | − | + | ND | ND | ND |
Esculin hydrolysis | ND | + | + | ND | + |
Voges-Proskauer reaction | − | − | ND | ND | − |
H2S production | − | ND | ND | − | + |
β-galactosidase | + | ND | ND | + | − |
β-glucuronidase | − | ND | ND | − | + |
Hippurate hydrolysis | ND | + | + | + | − |
Optochin resistance | − | ND | ND | ND | ND |
Acidification | |||||
Arginine | − | − | ND | ND | ND |
Mannitol | − | + | + | + | − |
Sorbitol | − | V | V | ND | − |
Arabinose | − | ND | V | ND | − |
Lactose | − | ND | + | ND | − |
Maltose | + | ND | + | ND | + |
Sucrose | − | ND | + | ND | + |
Inulin | − | ND | ND | − | + |
Ribose | − | ND | ND | + | − |