出典(authority):フリー百科事典『ウィキペディア(Wikipedia)』「2015/05/18 13:24:36」(JST)
Enterococcus faecalis | |
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Scientific classification | |
Domain: | Bacteria |
Kingdom: | Eubacteria |
Phylum: | Firmicutes |
Class: | Bacilli |
Order: | Lactobacillales |
Family: | Enterococcaceae |
Genus: | Enterococcus |
Species: | E. faecalis |
Binomial name | |
Enterococcus faecalis |
Enterococcus faecalis – formerly classified as part of the group D Streptococcus system – is a Gram-positive, commensal bacterium inhabiting the gastrointestinal tracts of humans and other mammals.[1] Like other species in the genus Enterococcus, E. faecalis can cause life-threatening infections in humans, especially in the nosocomial (hospital) environment, where the naturally high levels of antibiotic resistance found in E. faecalis contribute to its pathogenicity.[1] E. faecalis has been frequently found in root canal-treated teeth in prevalence values ranging from 30% to 90% of the cases.[2] Root canal-treated teeth are about nine times more likely to harbor E. faecalis than cases of primary infections.[3]
E. faecalis is a nonmotile, facultatively anaerobic microbe; it ferments glucose without gas production, and does not produce a catalase reaction with hydrogen peroxide. It can produce a pseudocatalase reaction if grown on blood agar. The reaction is usually weak. It produces a reduction of litmus milk, but does not liquefy gelatin. Growth on nutrient broth is consistent with being facultatively anaerobic. They catabolize a variety of energy sources including glycerol, lactate, malate, citrate, arginine, agmatine, and many keto acids. Enterococci survive very harsh environments including extremely alkaline pH (9.6) and salt concentrations. They resist bile salts, detergents, heavy metals, ethanol, azide, and desiccation. They can grow in the range of 10 to 45°C and survive at temperatures of 60°C for 30 min.[4]
E. faecalis can cause endocarditis and bacteremia, urinary tract infections, meningitis, and other infections in humans.[5][6] Several virulence factors are thought to contribute to E. faecalis infections. A plasmid-encoded hemolysin, called the cytolysin, is important for pathogenesis in animal models of infection, and the cytolysin in combination with high-level gentamicin resistance is associated with a five-fold increase in risk of death in human bacteremia patients.[7][8][9] A plasmid-encoded factor called "aggregation substance" is also important for virulence in animal models of infection.[8][10]
E. faecalis is resistant to many commonly used antimicrobial agents (aminoglycosides, aztreonam, cephalosporins, clindamycin, the semisynthetic penicillins nafcillin and oxacillin, and trimethoprim-sulfamethoxazole).[citation needed] Resistance to vancomycin in E. faecalis is becoming more common.[11][12] Treatment options for vancomycin-resistant E. faecalis include nitrofurantoin (in the case of uncomplicated UTIs),[13] linezolid, and daptomycin, although ampicillin is preferred if the bacteria are susceptible.[14] Quinupristin/dalfopristin can be used to treat Enterococcus faecium but not E. faecalis.[14]
In root canal treatments, NaOCl and chlorhexidine(CHX) are used to fight E. faecalis before isolating the canal. However, recent studies determined that NaOCl or CHX showed low ability to eliminate E. faecalis.[15]
Prior to 1984, enterococci were members of the genus Streptococcus; thus, E. faecalis was known as Streptococcus faecalis.[17]
In 2013, a combination of cold denaturation and NMR spectroscopy was used to show detailed insights into the unfolding of the E. faecalis homodimeric repressor protein CylR2.[18]
The E. faecalis genome contains 3,22 Mbp with 3,113 protein-coding genes.[19]
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国試過去問 | 「095D057」 |
リンク元 | 「細菌」「髄膜炎」「尿路感染症」「腸球菌属」「フェカリス菌」 |
関連記事 | 「faecal」「faecalis」 |
C
※国試ナビ4※ [095D056]←[国試_095]→[095D058]
4ヶ月未満 | B群溶連菌(50%) | 大腸菌(25%) | インフルエンザ菌(20%) | リステリア菌(1%) | |
4ヶ月~6歳未満 | インフルエンザ菌(70%) | 肺炎球菌(25%) | |||
6歳~50歳未満 | 肺炎球菌(65%) | インフルエンザ菌(10%) | 髄膜炎菌 | ||
50歳以上 | 肺炎球菌(80%) | 黄色ブドウ球菌 | |||
免疫不全者 | クレブシエラ | 連鎖球菌 | 緑膿菌 | 黄色ブドウ球菌 | 真菌 |
Newborn (0–6 mos) | Children (6 mos–6 yrs) | 6–60 yrs | 60 yrs + |
Streptococcus agalactiae | Streptococcus pneumoniae | Neisseria meningitidis | Streptococcus pneumoniae |
Escherichia coli | Neisseria meningitidis | Enteroviruses | Gram-negative rods |
Listeria | Haemophilus influenzae type B | Streptococcus pneumoniae | Listeria |
Enteroviruses | HSV |
1位 | 2位 | 3位 | |
新生児 | 大腸菌 | B群溶連菌 | リステリア菌 |
小児期(6歳以下) | インフルエンザ菌 | 肺炎球菌 | |
成人 | 肺炎球菌 | 髄膜炎菌 |
年齢 | 病原体 | ||
3ヶ月未満 | B群溶連菌 | 大腸菌 | リステリア菌 |
3ヶ月以上の乳小児 | インフルエンザ菌 | 肺炎球菌 | |
成人 | 肺炎球菌 | 髄膜炎菌 | |
高齢者 | 肺炎球菌 | グラム陰性桿菌 | リステリア菌 |
細菌性髄膜炎 | ウイルス性髄膜炎 | 結核性髄膜炎 | 真菌性髄膜炎 | 癌性髄膜炎 | |
外観 | 混濁 | clear | 水様~ キサントクロミー 日光微塵 |
clear~ 日光微塵 |
clear~ キサントクロミー |
圧 70-180 (mmH2O) |
↑↑ 200~800以上 |
↑ 200~300 |
↑ 200~800 |
↑ 200~800 |
↑ 200~300 |
細胞 0-5 (/mm3) |
500~数百万 | 10~1,000 | 25~1,000 | 25~1,000 | 25~500 |
好中球 | リンパ球 | リンパ球 | リンパ球 | 好中球 | |
タンパク 15-45 mg/dl |
↑↑ 50~1,500 |
↑ 正常~100 |
↑ 50~500 |
↑ 100~500 |
↑ 50~500 |
糖 50-80 mg/dl |
↓↓ 0~40 |
→ 正常 |
↓↓ ~40 |
↓↓ ~40 |
↓ ~40 |
糞便の
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