下部により溶血性、莢膜型が異なる。
直腸および腟の常在菌。新生児期および産褥期の母子感染。
出産後12-20日後に発症。新生児感染により敗血症、肺炎、髄膜炎

WordNet

a condition in which milk is not secreted in the mothers breasts after her child has been delivered (同)agalactosis

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/06 11:04:29」(JST)

wiki en

Streptococcus agalactiae (also known as Group B streptococcus or GBS) is a beta-hemolytic Gram-positive streptococcus.^[1]

Identification

This is an example of a positive CAMP test indicated by the formation of an arrowhead where the Strep group B (Streptococcus agalactiae) meets the Staphylococcus aureus (white middle streak).

The CAMP test is an important test for identification. GBS (group B Streptococcus species) are screened through this test. It is characterized by the presence of group B Lancefield antigen and by its ability to hydrolyze sodium hippurate.^[2]

It is also sensitive to bile, and will lyse in its presence.

S. agalactiae's polysaccharide antiphagocytic capsule is its main virulence factor.

Clinical significance

S. agalactiae is a member of the gastrointestinal normal flora in some humans and can spread to secondary sites - including the vagina in 10–30% of women. This is of clinical importance: S. agalactiae can be transferred to a neonate passing through the birth canal and can cause serious group B streptococcal infection.^[1] In the western world, S. agalactiae is the major cause of bacterial septicemia of the newborn, which can lead to death or long-term sequelae. S. agalactiae invades via alveolar and pulmonary epithelial cells; newborns are especially susceptible to infection because they lack alveolar macrophages to prevent invasion. Newborn GBS disease is separated into early-onset disease occurring on living days 0–7 and late-onset disease which starts on days 7–90. Early-onset septicemia is more prone to be accompanied by pneumonia, while late-onset septicimia is more often accompanied by meningitis. S. agalactiae neonatal meningitis doesn't present with the hallmark sign of adult meningitis, a stiff neck; rather, it presents with nonspecific symptoms, such as fever, vomiting and irritability, and can consequently lead to late diagnosis.^[1] Hearing loss can be a long-term sequela of GBS-meningitis. Infection with GBS is the cause of some instances of stillbirth.

S. agalactiae is present in up to one-third of women of childbearing age, and 1.8 cases per 1000 live births will be affected by group B streptococcal infection.^[1] In the elderly or persons with compromised immune systems, septicemia or other serious infections are seen. This can also occur during pregnancy or maternity.

Prevention

There is no reliable way to prevent newborn disease, currently; however, prophylactic treatment with antibiotics (typically intravenous penicillin) during delivery can prevent early-onset disease.^[1] Vaccination of adolescent women is considered an ideal solution; though research for the development of such a vaccine is underway, a good candidate vaccine has yet to surface.

Different western countries use different strategies to select which women in labor are most likely to need antibiotics.

The United States uses the most effective strategy: all pregnant women are screened for S. agalactiae^[3] and prophylactic antibiotics are given to all women testing positive . Because of this strategy, the US has seen a marked reduction in babies born with early-onset infection.^[4]
Increasingly, western countries are screening pregnant women routinely for GBS, including USA, Canada, France, Germany, Italy, Spain, Belgium, Canada, Australia, Czech Republic, Slovenia, Kenya and Argentina, with others offering a less effective risk-based strategy at time of delivery, including the UK, Denmark and Bulgaria.
Part of the neonatal care in Mexico includes undergoing a screening with culture of a cervicovaginal swab during the third trimester of pregnancy, though chemoprophylaxis based on positive results remains below 50%.^[5]

Nonhuman infections

S.agalactiae has been found in many mammals such as camels, dogs, cats, crocodiles, seals or dolphins.

Cattle

S.agalactiae was recognised as a pathogen in cattle before the Second World War. Its significance as human pathogen was not discovered before the 1950s. In cattle it causes mastitis, an infection of the udder. It can either give acute, febrile disease or sub-acute, more chronic disease. Both lead to diminishing milk production (hence its name: agalactiae meaning "no milk"). Outbreaks in herds are common. This is of major significance for the dairy industry and programs to reduce the impact of S.agalactiae disease have been enforced in many countries over at least the last 30–40 years.^[6]

Other animals

Fisheries and wildlife officers from Queensland, Australia, have been investigating the deaths of more than 50 grouper fish, between 2008 and 2010, that have washed up dead on beaches in the north of the state. The fish had been infected with S. agalactiae.^[7]

References

^ ^a ^b ^c ^d ^e Ryan KJ, Ray CG, et al, ed. (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 286–8. ISBN 0-8385-8529-9.
^ Smith JP, Durfee KK, Marymont JH (March 1979). "A review of laboratory methods for identification of group B streptococci (Streptococcus agalactiae)". Am J Med Technol 45 (3): 199–204. PMID 371403.
^ Apgar BS, Greenberg G, Yen G (March 2005). "Prevention of group B streptococcal disease in the newborn". Am Fam Physician 71 (5): 903–10. PMID 15768620.
^ Centers for Disease Control and Prevention (February 2009). "Trends in Perinatal Group B Streptococcal Disease - United States, 2000-2006". Morbidity and Mortality Weekly Report (MMWR) 58 (5): 109–112. PMID 19214159. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5805a2.htm.
^ Maternal chemoprophylaxis against group B Streptococcus colonization. The consequences of not adopting the international recommendation. Jesús Reyna-Figueroa, M en C M; Federico Javier Ortiz-Ibarra, MC; Beatriz Pérez-Antonio, MC; Sujey Navarro-Godínez, MC; Gerardo Casanova-Román, M en C BM; Laura Erika García-Carrillo, MC. Salud pública Méx v.50 n.2 Cuernavaca mar./abr. 2008
^ Keefe GP (July 1997). "Streptococcus agalactiae mastitis: a review". Can Vet J 38 (3): 199–204. PMC 1576741. PMID 9220132. //www.ncbi.nlm.nih.gov/pmc/articles/PMC1576741/.
^ Paull, Nathan (April 6, 2010). "Mystery groper deaths". Townsville Bulletin. http://www.townsvillebulletin.com.au/article/2010/04/05/127795_news.html. Retrieved April 6, 2010.

External links

Group B Strep Association
Group B Strep Support
Prevention of Perinatal Group B Streptococcal Disease August 16, 2002 MMWR 2000;49:228-232.

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UpToDate Contents

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1. 妊娠していない成人におけるB群レンサ球菌感染症 group b streptococcal infections in nonpregnant adults
2. 妊娠中の女性におけるB群レンサ球菌感染症 group b streptococcal infection in pregnant women
3. 新生児および乳児におけるB群レンサ球菌感染症 group b streptococcal infection in neonates and young infants
4. 新生児B群レンサ球菌感染症予防のための化学的予防 chemoprophylaxis for the prevention of neonatal group b streptococcal disease
5. B群レンサ球菌：病原性因子および発症機序 group b streptococcus virulence factors and pathogenic mechanisms

English Journal

Multiple-locus variant-repeat assay (MLVA) is a useful tool for molecular epidemiologic analysis of Streptococcus agalactiae strains causing bovine mastitis.

Radtke A, Bruheim T, Afset JE, Bergh K.SourceNorwegian University of Science and Technology, Department of Laboratory Medicine, Children's and Women's Health, Trondheim, Norway; St. Olavs University Hospital, Department of Medical Microbiology, Trondheim, Norway.
Veterinary microbiology.Vet Microbiol.2012 Jun 15;157(3-4):398-404. Epub 2012 Jan 8.
Group B streptococci (GBS) were considered a major cause of mastitis in cattle until preventive measures succeeded in controlling the disease in the 1970s and 1980s. During the last 5-6years an increasing number of cases have been observed in some Scandinavian countries. A total of 187 GBS isolates
PMID 22266162

Discordant Streptococcus agalactiae (Group B streptococcus) gestational infection in monochorionic/diamniotic and dichorionic/diamniotic twins.

Pimentel JD, Szymanski LJ, Samuel LP, Meier FA.SourceDepartment of Pathology and Laboratory Medicine, Henry Ford Hospital, Detroit, Michigan 48202, USA. jasondpimentel@live.com
Fetal and pediatric pathology.Fetal Pediatr Pathol.2012 Jun;31(3):176-83. Epub 2012 Mar 13.
Infection due to Streptococcus agalactiae or Group B streptococcus may be acquired during parturition or gestation. Discordant twin gestational Group B streptococcus infections are rarely reported. We describe two cases of fatal discordant gestational Group B streptococcus infection in both a monoch
PMID 22414062

L-Ficolin and Capsular Polysaccharide-Specific IgG in Cord Serum Contribute Synergistically to Opsonophagocytic Killing of Serotype III and V Group B Streptococci.

Fujieda M, Aoyagi Y, Matsubara K, Takeuchi Y, Fujimaki W, Matsushita M, Bohnsack JF, Takahashi S.SourceDivisions of Microbiology.
Infection and immunity.Infect Immun.2012 Jun;80(6):2053-60. Epub 2012 Mar 26.
Group B streptococci (GBS; Streptococcus agalactiae) are the most common cause of neonatal sepsis and meningitis. Serotype-specific IgG antibody is known to protect neonates against GBS infections by promoting opsonophagocytosis. The L-ficolin-mediated lectin pathway of the complement is also a pote
PMID 22451515

Japanese Journal

弁輪部高度破壊を伴った僧帽弁位人工弁感染の1手術例

西木慎太朗,郷田素彦,合田真海,鈴木伸一,磯松幸尚,李相憲,沖山信,岩城秀行,井元清隆,益田宗孝
日本心臓血管外科学会雑誌 44(1), 16-20, 2015
症例は79歳女性．16年前に感染性心内膜炎のため機械弁（Björk-Shiley弁）による僧帽弁置換術が施行された．2013年3月，40°Cの発熱を認め，前医で人工弁感染と診断された．僧帽弁人工弁周囲逆流による高度心不全のため人工呼吸管理となり，当院に転院搬送された．来院時，WBC 15,700/µl，CRP 7.29 mg/dlと炎症反応の上昇を認めた．また，Hb 8.1 g/dlの貧血，Plt …
NAID 130004887243

Comparative Analysis of Penicillin-Susceptible and Non-Susceptible Isolates in Group B Streptococci by Multilocus Sequence Typing

, , , , , , , , ,
Japanese Journal of Infectious Diseases advpub(0), 2015
… Since Group B Streptococcus (GBS, Streptococcus agalactiae) clinical isolates were believed to be uniformly susceptible to β-lactams, penicillin G has been the first-line agent for the prevention and treatment of GBS infections. …
NAID 130004757178

Streptococcus agalactiaeによる化膿性関節炎3例の検討

水谷哲,寺地つね子
日本骨・関節感染症学会雑誌 28, 61-67, 2014
NAID 40020387968

血液培養由来β溶血性レンサ球菌検出率と感受性の年次推移

伊藤愛美,野村秀和,森本瞳,鎌倉明美,棚村一彦,赤津義文,大塚喜人
医学検査 63(2), 236-240, 2014
… 2007・2009・2011年度の3ヶ年に5施設の血液培養から検出されたβ溶血性レンサ球菌216株を対象に，Streptococcus pyogenes（Group A Streptococcus：GAS），Streptococcus agalactiae（Group B Streptococcus：GBS）およびGAS・GBS以外のβ溶血性レンサ球菌（non-AB）の3つの菌グループに区分し，検出率と抗菌薬感受性の推移を調査した．検出率に大きな変動は無かったが，S. …
NAID 130005057057

Related Pictures

★リンクテーブル★

リンク元	「髄膜炎」「連鎖球菌属」「周産期感染症」「バシトラシン」「B群連鎖球菌」
拡張検索	「Streptococcus agalactiae感染症」「Streptococcus agalactiae infection」

「髄膜炎」

Streptococcus agalactiae
Scientific classification
Kingdom:	Bacteria
Phylum:	Firmicutes
Class:	Bacilli
Order:	Lactobacillales
Family:	Streptococcaceae
Genus:	Streptococcus
Species:	S. agalactiae
Binomial name
	Streptococcus agalactiae; Lehmann and Neumann, 1896

　　[★]

英: meningitis
同: 脳脊髄膜炎、
関: 蛋白細胞解離

病因

感染症(細菌、ウイルス、真菌など)、悪性腫瘍の浸潤　→　髄膜の炎症

分類

病原体

細菌性髄膜炎

菌血症→脳脈絡叢→髄腔
菌体成分(LPSなど)→BBB, 上衣細胞、脳細胞の障害。神経膠細胞による炎症サイトカインの分泌

無菌性髄膜炎

血行性、あるいは神経軸索によりウイルスが髄腔に波及。

細菌性髄膜炎：様々
ウイルス性髄膜炎：コクサッキーウイルス、エコーウイルス、ムンプスウイルス、単純ヘルペスウイルス、風疹ウイルス、麻疹ウイルス、水痘・帯状疱疹ウイルス
真菌性髄膜炎：クリプトコッカス髄膜炎
結核性髄膜炎：結核菌
梅毒性髄膜炎：梅毒菌

臨床経過

宿主要因と髄膜炎に関わる病原体

頻度・年齢階層が資料によって異なるため混乱しないように注意。

YN.J-137改変

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

first aid step1 2006 p.161

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

HIV: Cryptococcus, CMV, toxoplasmosis (brain abscess), JC virus (PML)

incidence of H. influenzae meningitis has ↓ greatly with introduction of H. influenzae vaccine in last 10–15 years.

CBT QB vol2 p.562

	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

IMD.1042

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

小児細菌性髄膜炎起炎菌(PED.606)

		<3か月	3か月≦
グラム陽性	球菌	Streptococcus agalactiae Streptococcus pneumoniae Staphylococcus Enterococcus faecalis	Streptococcus pneumoniae(PSSP/PISP/PRSP)
グラム陽性	桿菌	Listeria monocytogenes	Listeria monocytogenes
グラム陰性	球菌	Neisseria meningitidis	Neisseria meningitidis
グラム陰性	桿菌	Escherichia coli Enterobacter cloacae Serratia marcescens	Haemophilus influenzae type b

新生児

Streptococcus agalactiaeは産道感染
Escherichia coliもおそらく産道感染

新生児と老人

Listeria monocytogenesは産道感染するので新生児に多い。新生児と老人に多いのは通性細胞内寄生菌で細胞性免疫の弱い宿主に感染やすいため？

乳児～幼児

Haemophilus influenzae type B

乳児～大人

Enteroviruses
Neisseria meningitidis

小児～大人

Herpes simplex virus

乳児～老人

Streptococcus pneumoniae

老人

グラム陰性桿菌は老人

髄膜炎の鑑別

	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
細胞 0-5 (/mm3)	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