Granulicatella adiacens | |
---|---|
Scientific classification
![]() | |
Domain: | Bacteria |
Phylum: | Bacillota |
Class: | Bacilli |
Order: | Lactobacillales |
Family: | Carnobacteriaceae |
Genus: | Granulicatella |
Species: | G. adiacens
|
Binomial name | |
Granulicatella adiacens Collins & Lawson, 2000
[1]
|
Granulicatella adiacens is a fastidious Gram-positive cocci (pairs, chains) and is part of the nutritionally variant streptococci (NVS). [2] [3] [4] Like other constituents of the NVS, it can cause bacteremia and infective endocarditis (IE), with significant morbidity and mortality. [4] [2] NVS has less often been implicated in a variety of other infections, including those of the orbit, nasolacrimal duct and breast implants. [5] It is a commensal of the human mouth, genital, and intestinal tracts, although it is rarely implicated in infections, [5] [2] in part due to it being a fastidious organism and rarely being identified in the laboratory environment. [5] However, its identification has become more frequent with use of commercial mediums and automated identification systems. [5] Because it has been difficult to identify, it has been considered one of the causes of culture negative IE. [2] Identifying G. adiacens can allow more appropriate selection of antibiotics, especially when susceptibility testing is not available. [4]
Antibiotic | Susceptible (%) |
---|---|
Penicillin | 38.9 |
Cefotaxime | 18.9 |
Ceftriaxone | 43.3 |
Erythromycin | 52.2 |
Levofloxacin | 84.5 |
Clindamycin | 91.9 |
Meropenem | 100 |
Vancomycin | 100 |
Of human diseases caused by G. adiacens, infective endocarditis (IE) is the most common. [5] Among the members of the genus Granulicatella, G. adiacens seems to be more capable of causing IE, possibly due to its capacity to bind to the cardiac valvular tissue. [2] IE from NVS species has been described as indolent-onset, often in the setting of preexisting heart valve damage. [2] The aortic and mitral valves are most commonly affected. [2] More often than not, IE due to NVS produces detectable vegetations, although other classic IE signs (e.g., Osler nodes) are usually not present. [2] Treatment failure is frequently observed, and approximately 1/4 of cases require prosthetic valve replacement. [2]
The Granulicatella genus is more resistant to antibiotics than viridans streptococci (another common cause of IE), although it is still often susceptible to clindamycin, erythromycin, rifampicin and vancomycin. [2]
Granulicatella spp. have been associated with malodorous breath ( halitosis) in Japan. [3]
It grows best on media supplemented with thiol or pyridoxal. [5] Phenotypic identification of this genus is difficult, but feasible with automated identification systems. [5] 16S rRNA gene sequencing is confirmatory. [5]
In 1961, a new type of viridans streptococci was classified as "nutritionally variant streptococci" (NVS). [3] In 1989, NVS was subdivided into Streptococcus defectiva and Streptococcus adiacens, which in 1995 were relocated to create a new genus Abiotrophia. [3] [2] In 2000, three members of the Abiotrophia genus were reclassified into the genus Granulicatella (Granulicatella adiacens, balaenopterae and elegans). [2]
Granulicatella adiacens | |
---|---|
Scientific classification
![]() | |
Domain: | Bacteria |
Phylum: | Bacillota |
Class: | Bacilli |
Order: | Lactobacillales |
Family: | Carnobacteriaceae |
Genus: | Granulicatella |
Species: | G. adiacens
|
Binomial name | |
Granulicatella adiacens Collins & Lawson, 2000
[1]
|
Granulicatella adiacens is a fastidious Gram-positive cocci (pairs, chains) and is part of the nutritionally variant streptococci (NVS). [2] [3] [4] Like other constituents of the NVS, it can cause bacteremia and infective endocarditis (IE), with significant morbidity and mortality. [4] [2] NVS has less often been implicated in a variety of other infections, including those of the orbit, nasolacrimal duct and breast implants. [5] It is a commensal of the human mouth, genital, and intestinal tracts, although it is rarely implicated in infections, [5] [2] in part due to it being a fastidious organism and rarely being identified in the laboratory environment. [5] However, its identification has become more frequent with use of commercial mediums and automated identification systems. [5] Because it has been difficult to identify, it has been considered one of the causes of culture negative IE. [2] Identifying G. adiacens can allow more appropriate selection of antibiotics, especially when susceptibility testing is not available. [4]
Antibiotic | Susceptible (%) |
---|---|
Penicillin | 38.9 |
Cefotaxime | 18.9 |
Ceftriaxone | 43.3 |
Erythromycin | 52.2 |
Levofloxacin | 84.5 |
Clindamycin | 91.9 |
Meropenem | 100 |
Vancomycin | 100 |
Of human diseases caused by G. adiacens, infective endocarditis (IE) is the most common. [5] Among the members of the genus Granulicatella, G. adiacens seems to be more capable of causing IE, possibly due to its capacity to bind to the cardiac valvular tissue. [2] IE from NVS species has been described as indolent-onset, often in the setting of preexisting heart valve damage. [2] The aortic and mitral valves are most commonly affected. [2] More often than not, IE due to NVS produces detectable vegetations, although other classic IE signs (e.g., Osler nodes) are usually not present. [2] Treatment failure is frequently observed, and approximately 1/4 of cases require prosthetic valve replacement. [2]
The Granulicatella genus is more resistant to antibiotics than viridans streptococci (another common cause of IE), although it is still often susceptible to clindamycin, erythromycin, rifampicin and vancomycin. [2]
Granulicatella spp. have been associated with malodorous breath ( halitosis) in Japan. [3]
It grows best on media supplemented with thiol or pyridoxal. [5] Phenotypic identification of this genus is difficult, but feasible with automated identification systems. [5] 16S rRNA gene sequencing is confirmatory. [5]
In 1961, a new type of viridans streptococci was classified as "nutritionally variant streptococci" (NVS). [3] In 1989, NVS was subdivided into Streptococcus defectiva and Streptococcus adiacens, which in 1995 were relocated to create a new genus Abiotrophia. [3] [2] In 2000, three members of the Abiotrophia genus were reclassified into the genus Granulicatella (Granulicatella adiacens, balaenopterae and elegans). [2]