Biology:Granulicatella adiacens

From HandWiki
Short description: Bacteria


Granulicatella adiacens
Scientific classification edit
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]

Clinical relevance

Granulicatella adiacens susceptibility in California[4][5]
Antibiotic Susceptible (%)
Penicillin 38.9
Cefotaxime 18.9
Ceftriaxone 43.3
Erythromycin 52.2
Levofloxacin 84.5
Clindamycin 91.9
Meropenem 100
Vancomycin 100

Infective endocarditis

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]

Antibiotic treatment

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]

Malodorous breath

Granulicatella spp. have been associated with malodorous breath (halitosis) in Japan.[3]

Laboratory identification

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]

Classification history

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]

References

  1. Collins, MD; Lawson, PA (January 2000). "The genus Abiotrophia (Kawamura et al.) is not monophyletic: proposal of Granulicatella gen. nov., Granulicatella adiacens comb. nov., Granulicatella elegans comb. nov. and Granulicatella balaenopterae comb. nov.". International Journal of Systematic and Evolutionary Microbiology 50 Pt 1: 365–369. doi:10.1099/00207713-50-1-365. PMID 10826824. 
  2. 2.00 2.01 2.02 2.03 2.04 2.05 2.06 2.07 2.08 2.09 2.10 2.11 Shailaja, TS; Sathiavathy, KA; Unni, Unni (July 2013). "Infective endocarditis caused by Granulicatella adiacens.". Indian Heart Journal 65 (4): 447–9. doi:10.1016/j.ihj.2013.06.014. PMID 23993006. 
  3. 3.0 3.1 3.2 3.3 Gardenier, JC; Hranjec, T; Sawyer, RG; Bonatti, H (June 2011). "Granulicatella adiacens bacteremia in an elderly trauma patient.". Surgical Infections 12 (3): 251–3. doi:10.1089/sur.2010.059. PMID 21524203. 
  4. 4.0 4.1 4.2 4.3 Alberti, Michael O.; Hindler, Janet A.; Humphreys, Romeny M. (26 February 2016). "Antimicrobial Susceptibilities of Abiotrophia defectiva, Granulicatella adiacens, and Granulicatella elegans". Antimicrobial Agents and Chemotherapy 60 (3): 1411–1420. doi:10.1128/AAC.02645-15. PMID 26666926. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 Gupta, Sangita; Garg, Meenu; Misra, Sanjay; Singhal, Sanjay (Jan–Mar 2018). "Granulicatella adiacens abscess: Two rare cases and review". Journal of Laboratory Physicians 10 (1): 121–123. doi:10.4103/JLP.JLP_58_17. PMID 29403221. 

External links

Wikidata ☰ Q25859800 entry