يرسينيا بستس
YERSINIA PESTIS
| يرسينيا بستس | |
|---|---|
| A scanning electron microscope micrograph depicting a mass of Yersinia pestis bacteria. | |
| التصنيف الفهمي | |
| Domain: | Bacteria |
| مملكة: | Eubacteria |
| Phylum: | Proteobacteria |
| Class: | Gammaproteobacteria |
| Order: | Enterobacteriales |
| Family: | Enterobacteriaceae |
| Genus: | ''Yersinia |
| Species: | ''Y. pestis'' |
| Binomial name | |
|
Yersinia pestis (Lehmann & Neumann, 1896) van Loghem 1944 | |
- أول جرثومة تصدى لها الفهماء لكونها أكثر جرثومة فتكاً بالبشر فهي تسبب سقم الطاعون pestilence (pest).
- سابقاً كان يأتي الطاعون بموجات تقتل نصف أوثلث سكان الأرض في جميع مرة. فقد كان يعتبر أخطر الأمراض على الإطلاق، وقد كان سلاح جرثومي خطير طبعاً ذلك قبل اكتشاف اللقاحات والصادات المناسبة.
- هذا السقم قد اختفى تقريباً من العالم، ولكن مازال هناك بؤر على القوارض والفئران في بعض مناطق جبال بين أفغانستان وإيران، ومنطقة بجنوب إفريقيا ومنطقة بالأمازون وهذه الجرثومة عليها مراقبة عالمية.
سقم الطاعون (pestilence (pest:
يوجد نوعين لهذا السقم: بدئي (الرئوي): خطير ينتقل عن طريق التنفس. عادي (المعوي): ينتقل عن طريق الهضم. الطاعون الرئوي هوالمسبب للجائحات العالمية الكبيرة التي كانت تحدث. والطاعون العادي (المعوي) هوالطاعون المستوطن endemic والذي ينتقل ببطء ويمكن حتى يسبب جائحة وبنفس الأعراض لكن طريقة الانتنطق تختلف وشدة الأعراض تختلف
مستضدات الجروم:
يوجد مستضدات لهذا الجرثوم وهي: مستضدات v وw.
- يمكن الكشف عن هذه المستضدات للتعهد على الجرثوم من خلال التفاعلات المصلية.
- إذا حدثت جائحة طاعون بمنطقة ما فليس من الضروري حتى يصاب بالطاعون جميع الأشخاص فهناك نسبة تستطيع مقاومة السقم (حوالي 10%) ولذا تعد زراعة الجرثوم والتعهد عليه بالمخبر مهمة وهي أسرع من التفاعلات المصلية.
- وعملياً لنقد يكون هناك صعوبة بتشخيص الطاعون كون الأعراض معروفة وتحدث بشكل جائحة..
صفات عامة
Y. pestis is a rod-shaped facultative anaerobe with bipolar staining (giving it a safety pin appearance). Similar to other Yersinia members, it tests negative for urease, lactose fermentation, and indole. The closest relative is the gastrointestinal pathogen Yersinia pseudotuberculosis, and more distantly Yersinia enterocolitica.
الامراضية والمناعة
In the urban and sylvatic (forest) cycles of Y. pestis, most of the spreading occurs between rodents and fleas. In the sylvatic cycle, the rodent is wild, but in the urban cycle, the rodent is domestic. Additionally Y. pestis can spread from the urban environment and back again. Every infected animal can transmit the infection to humans through contact with skin tissue. Humans can also spread the bacteria to other humans through sneezing, coughing or direct contact with infected tissue.
Symptoms and disease progression
- Bubonic plague
- Incubation period of 2–6 days, when the bacteria is actively replicating.
- Universally a general lack of energy
- Fever
- Headache and chills occur suddenly at the end of the incubation period
- Swelling of lymph nodes resulting in buboes, the classic sign of bubonic plague
- Septicemic plague
- Hypotension
- Hepatosplenomegaly
- Delirium
- Seizures in children
- Shock
- Universally a general lack of energy
- Fever
- Symptoms of bubonic or pneumonic plague are not always present
- Pneumonic plague
- Fever
- Chills
- Cough
- Chest pain
- Dyspnea
- Hemoptysis
- Lethargy
- Hypotension
- Shock
- Symptoms of bubonic or septicemic plague are not always present
If this occurs with the classic buboes, this is considered primary, while secondary occurs after symptoms of bubonic or pneumonic infection. Since the bacteria are blood-borne, several organs can be affected including the spleen and brain. The diffuse infection can cause an immunologic cascade to occur, leading to disseminated intravascular coagulation (DIC), which in turn results in bleeding and necrotic skin and tissue. Such a disseminated infection increases mortality to 22%.
With the exception of the buboes, the initial symptoms of plague are very similar to many other diseases, making diagnosis difficult.
ICD-9 codes for the diseases caused by Y. pestis:
- 020.0 Bubonic plague
- 020.2 Septicemic plague
- 020.5 Unspecified pneumonic plague
- 020.3 Primary pneumonic plague
- 020.4 Secondary pneumonic plague
المعالجة=
The traditional first line treatment for Y. pestis has been streptomycin,chloramphenicol, tetracycline, and fluoroquinolones. There is also good evidence to support the use of doxycycline or gentamicin. Resistant strains have been isolated; treatment should be guided by antibiotic sensitivities where available. Antibiotic treatment alone is insufficient for some patients, who may also require circulatory, ventilator, or renal support.
In an emergency department setting, Harrison's Principles of Internal Medicine outlines the following treatment course. Antibiotics within the first 24 hours are very beneficial, with intravenous being preferred in pulmonary or advanced cases. Streptomycin or gentamicin are the first-line drugs, with chloramphenicol for critically ill patients, or rarely for suspected neuro-involvement.
الهامش
- ^ Collins FM (1996). (4th ed.). Univ. of Texas Medical Branch. ISBN .
- ^ Stackebrandt, Erko; Dworkin, Martin; Falkow, Stanley; Rosenberg, Eugene; Karl-Heinz Schleifer (2005). The Prokaryotes: A Handbook on the Biology of Bacteria:Volume 6: Proteobacteria: Gamma Subclass. Berlin: Springer. ISBN .CS1 maint: multiple names: authors list (link)
- ^ Info taken from "Harrison's Principles of Internal Medicine 16th Edition"
- ^ Prentice MB, Rahalison L (2007). "Plague". Lancet. 369 (9568): 1196–207. doi:10.1016/S0140-6736(07)60566-2. PMID 17416264.
- ^ Wagle PM. (1948). "Recent advances in the treatment of bubonic plague". Indian J Med Sci. 2: 489–94.
- ^ Meyer KF. (1950). "Modern therapy of plague". JAMA. 144 (12): 982–5. PMID 14774219.
- ^ Kilonzo BS, Makundi RH, Mbise TJ. (1992). "A decade of plague epidemiology and control in the Western Usambara mountains, north-east Tanzania". Acta Tropica. 50 (4): 323–9. doi:10.1016/0001-706X(92)90067-8. PMID 1356303.CS1 maint: multiple names: authors list (link)
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^ Mwengee W, Butler T, Mgema S; et al. (2006). "Treatment of plague with gentamicin or doxycycline in a randomized clinical trial in Tanzania". Clin Infect Dis. 42 (5): 614–21. doi:10.1086/500137. PMID 16447105. Explicit use of et al. in:
|author=(help)CS1 maint: multiple names: authors list (link) - ^ Jameson, J. N. St C.; Dennis L. Kasper; Harrison, Tinsley Randolph; Braunwald, Eugene; Fauci, Anthony S.; Hauser, Stephen L; Longo, Dan L. (2005). Harrison's principles of internal medicine. New York: McGraw-Hill Medical Publishing Division. ISBN .CS1 maint: multiple names: authors list (link)
روابط اضافية
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مشاع الفهم فيه ميديا متعلقة بموضوع Yersinia pestis. |
- . Virtual Museum of Bacteria.
- A list of variant strains and information on synonyms (and much more) is available through the NCBI taxonomy browser.
- CDC's Home page for Plague [1]
- IDSA's resource page on Plague: Current, comprehensive information on pathogenesis, microbiology, epidemiology, diagnosis, and treatment[2]
