Searching for microbes Part XI. Virology – Part Two

1. Searching for microbesPart XI.Virology – Part Two Ondřej Zahradníček To practical of aVLLM0421c zahradnicek@fnusa.cz

2. Story Content of this slideshow Viruses of measles, mumps and rubella Viruses of influenza More respiratory viruses Mycoplasmas Virus of tick-borne encephalitis Some viral properties important for diagnostics Survey of virology diagnostics Microscopy in virology. Viral isolation Indirect diagnostics of viruses Check-up questions

3. Story • Mr. Lungman was already a week in a hospital because of long term respiratory problems. A group of medical students started to examinate him, but they found no pathological finding. • But then a student, Miss Diligentous spoke: „Patient has a dry cough, physical examination showed nothing. What about an atypical pneumonia?“ The teacher smiled: Excellent, I am glad that someone found it!

4. Atypical pneumoniae • The term is now considered obsolete, nevertheless we can use it for pneumoniae that • have a slow oncome, rather non-productive cough, and physical symptomatology is often absent (but x-rays show a visible finding) • are not caused by culturable bacteria (e. g. Streptococcus pneumoniae) • are mostly caused by: • respiratory viruses (see further) • atypical bacteria, (Mycoplasma pneumoniae, or Chlamydia/Chlamydophila pneumoniae, Legionella sp. • In case of bacterial agents, antibiotic therapy (doxycyklin, macrolides) is possible

5. The viruses described in this slideshow: • viruses of rubella, mumps and measles • respiratory viruses • influenzavirus A and B • parainfluenzavirus • RS viruses • adenoviruses • Mycoplasma pneumoniae – not a virus, but diagnosed using virological methods • virus of tick-borne encephalitis

6. MeaslesMumpsRubella

7. Measles, mumps and rubella • Although they are not related, one is common for them: vaccination. Living attenutated vaccines is used agaings all of them. Usually they are vaccinated together as the “MMR trivaccine“ • All of them cause childhood diseases; some people believe that they are not serious and hesitate to let their children vaccinated. Nevertheless, they might have serious complications and kill people • Rubella virus belongs to the Togaviridae family, measles and mumps viruses are members of Paramyxoviridae

8. A fresh (2017) news from media

9. Togaviridae • They are RNA enveloped viruses. They are the simpliest animal enveloped viruses. They are small (60–70 nm). Coat (toga in Latin) is made of cell lipids, viral glycoproteins are prominent • This family contains genus Alphavirus, that is arthropode borne (so they are arboviruses): american viruses of equine encephalitis, african chikungunya and o‘nyong nyong viruses • The most important for humans is Rubivirus – rubella virus

10. Rubivirus (virus of rubella/rubeola) • Virus of measles (rubeo = I am glowing red) is a purely human virus • Measles are a benign childhood disease. Transmission by air, incubation 16–18 days, virus strarts to be excreted by nasopharynx even before the rash. Dangerous is the disease in pregnant women, escpecially in the first trimester there is a risk of inborn defects – malformations of the hearth, hearing or other organs. Nevertheless, it is also possible that the child is born completely healthy

11. Diagnostics, prevention, treatment • Diagnostics is usually not needed, clinical examination is sufficient • The virus is multiplied on the cell cultures, but there is no CPE. Multiplication of the virus can be checked by an interference – if there is a rubivirus on the culture, the echovirus 11 (for example), that would perform a cytopatic effect, cannot multiply • Indirect diagnostics is possible by HIT, VNT and ELISA. Avidity of antibodies is checked • Treatment is symptomatic

12. Virus of rubella http://vietsciences.free.fr/khaocuu/nguyenlandung/virus01.htm

13. Rubella http://www.vaccineinformation.org/photos/rubeiac002.jpg http://pediatrics.about.com/library/pictures/bl_rubella.htm

14. Paramyxoviridae • This family encomprises many RNA enveloped viruses important for humans: • Subfamily Paramyxovirinae • Respirovirus – virus of parainfluenza 1 and 3 • Morbillivirus – virus of measles • Rubulavirus – virus of mumps, viruses of parainfluenza 2, 4a, 4b • Subfamily pneumovirinae • Pneumovirus – human RS virus • Metapneumovirus – human metapneumovirus

15. Mumps virus • Mumps are a generalised infection, that comes from the respiratiory mucosa to the whole organism. It does not always attact salivary glands, but is uses to do it. It may also attack pankreas, milk glan and testicles, that is why measles are dangerous in man after pubescence. They are also important for pregnant women • Diagnostics contains HIT, CFT, ELISA or viral isolation • Treatment is only symptomatic

16. Mumps virus http://vietsciences.free.fr/khaocuu/nguyenlandung/virus01.htm

17. Mumps http://toolbox.esu16.k12.ne.us/oscience/Physiology/Projects/JoshM.htm

18. Mumps http://childrensspecialists.com/body.cfm?id=1056 http://toolbox.esu16.k12.ne.us/oscience/Physiology/Projects/JoshM.htm

19. Three in one http://www.cartoonstock.com/directory/r/rubella_gifts.asp

20. Measles virus • Unlike majority of other viral diseases, there are no asymptomatic infections in measles. After 10–11 days of incubation the fever, rhinitis, cough, conjuntivitis is started, and late a characteristic rash that starts on the faces and behind the ears, after 3–4 days it disappears. In the mouth we can see Koplik spots. • Reactivation in adults may rarely have a form of a subacute sklerotising panencefalitis (SSPE) • Diagnostics ELISA, CFT, HIT

21. Measles virus http://vietsciences.free.fr/khaocuu/nguyenlandung/virus01.htm

22. Measles http://www.nytimes.com/imagepages/2006/04/30/world/20060430_MEASLES_GRAPHIC.2.html

23. Measles (Koplik spots on the right) http://www.bact.wisc.edu/themicrobialworld/ViralDisease.html

24. Measles www.lib.uiowa.edu/hardin/md/measles.html. http://z.about.com/d/pediatrics/1/0/e/2/measles.jpg

25. Measles in short www.gypsy-traveller.org/health/measles.htm.

26. The more vaccination, the less measles http://www.who.int/immunization_monitoring/diseases/measles/en/index.html

27. Viruses of influenza

28. Influenza (flu) • It is a disease of the whole body, but mostly lower respiratory ways. Neither rhinitis, nor sore throat belongs to typical course. Rather dry cough, high fever, myalgia, acute oncome. Sometimes also intestinal problem may occur. • Influenza is often dangerous in immunocomprmissed persons (mostly prolonged), pregnant, in elderly. On the other hand, some subtypes are rather dangerous for young people with very good imunity. This is because of „cytokine storms“ (the problems are related with immunity overreaction) • Influenza A, B and C exist; majority of epidemics is caused by virus of influenza A

29. Influenzavirus A http://micro.magnet.fsu.edu/cells/viruses/influenzavirus.html

30. Influenzavirus A – antigens • Among characteristics of influenzavirus, the most important is antigenic variability. In influenzavirus, we have 15 subtypes according to haemaglutinin antigen (H) and 9 subtypes according to neuraminidase (N). • An antigenic drift is a natural mutation in antigenic structure coding genes of a know type of a virus. It does not bring a completely new virus type • An antigenic exchange – shift means a reassortment of two or more types of a virus (e. g. avian + human) to a new type. Shift only exists in influenza A, as the other types are purely human • Antigenic shift is enabled by segmented genome

31. Influenza virus gustavorinaldi.blog.lastampa.it

32. Influenza pandemics • As viruses change, sometimes a new variant occurs and nobody is protected against it. Such a virus is then able to produce outbreaks, epidemics or even pandemics in large areas. Of course, it is never possible to predict the course of them. • Viruses able to perform an outbreak in human population should have not only elevated virulence, but also the ability to be transmitted person-to-person. Bird viruses rarelly have such ability. Hogs usually serve as „mixing jar“. So virulence factors from birds usually become dangerous after reassortment or recombination with parts of mammal viruses.

33. Influenza pandemics 2 • During World War One many people died because of so called Spanish influenza • During following decades, there were many relatively smaller epidemics (Hong-Kong flu, Singapore flu) • The last epidemics („swine influenza“) was caused by a virus belonging to group A:H1N1. The mere term „A:H1N1“ does not mean anything new, but the detail structure was special, the virus contained parts that are human, avian and swine origin

34. Influenza – prevention, prophylaxis, treatment • Prevention possible by vaccination, recommended mostly to diseased persons. It protects only against subtypes actually present in population, not against new viral subtypes • For prophylaxis and treatment, we can use some antivirotics: inhibitors of protein M2 (amantadin and rimantadin, some strains became resistant already), and inhibitors of neuraminidase (zanamivir and oseltamivir – factory names TAMIFLU and RELENZA). • Antivirotics should be used for relevant reasons only. Using them „preventively“ because of panic might lead to development to resistance.

35. Influenzavirus www.ontariogenomics.ca/education/episode6.asp http://www.bio-pro.de/en/region/rhein/magazin/01112/index.html

36. Influenzavirus – life cycle http://www.accessexcellence.org/RC/VL/GG/influenza.php

37. In flew Enza  From book „A practical guide to clinical bacteriology“, Pattison JR et al., Wiley, London 1995

38. More respiratory viruses

39. Parainfluenzaviruses • They are paramyxoviruses, related with mumps virus and less related with measles • Unlike the true flu they often cause cathars of upper respiratory ways. Nevertheless, flu-like cough may be too, but mostly (especially in adults) without fever. • Diagnostics: CFT, HIT, ELISA; there are some cross-reactions. A direct diagnostics in nasopharynx using isolation on cell cultures possible, too.

40. RS virus (respiratory syncytia virus, pneumovirus) • Related (not very closely) to parainfluenza • RS-virus is an important pathogen of lower respiratory ways in first half of year • As the name says, they cause confluence of infected cells (syncytia) • Diagnostics – ELISA, direct dg. – cell cultures • Metapneumovirus is a newer virus related to pneumovirus

41. Adenoviruses – Uncoated DNA viruses • First isolated 1953 from an adenoid vegetation • They are human, animal and bird viruses • They are medium sized (80 nm), uncoated, with cubic symmetry of capsid. They have shape of a perfectly regular icosaedre. The capsid is composed of 240 hexons a 12 top pentons. • We know 47 serotypes of adenoviruses, that can be pathogenic for humans. They could differ in symptoms and diagnostic.

42. Adenovirus http://www.tulane.edu/~dmsander/Big_Virology/BVDNAadeno.html

43. Human adenoviruses • They may cause common cold, pharyngitis, conjunctivitis (light to serious) • Types 40 and 41 (different also by being unculturable) cause diarrhoea in babies • One type may cause inflammation of urinary bladder with bleeding • Diagnostics is culture (cell cultures) and serological (complementfixing test) • Target therapy is impossible

44. http://web.uct.ac.za/depts/mmi/stannard/emimages.html Adenovirus

45. Adenoviruses http://www.tulane.edu/~dmsander/Big_Virology/BVDNAadeno.html

46. Mycoplasmas

47. Mycoplasmas http://www.unmc.edu/dept/biochemistry

48. Mycoplasmas • strange group of bacteria – Mollicutes – „the ones with soft skin" • they have no cell wall • their shape might be oval, round or filamentous • in humans, genera Mycoplasma and Ureaplasma are important • smallest organisms with no need for an alien cells • several times smaller than common bacteria

49. www.invivogen.comv www.rowland.harvard.edu

50. Mycoplasma pneumoniae • causative agent of atypical pneumoniae • sometimes extrapulmonar complications (hearth, nerves etc.) • on the other hand, often only common-cold-like or asymptomatic • transmission by air