C hair of M icrobiology, V irology, and I mmunology

1. Chair of Microbiology, Virology, and Immunology DNA-VIRUSES. ADENOVIRUSES. HERPESVIRUSES.

2. ADENOVIRUS (ADV) DNA viruses first isolated from adenoidal tissue in 1953 Family Adenoviridae Genus Mastadenovirus There names adenoid degenerationviruses adenoid-pharingeal conjunctivalviruses acute respiratory desease agents.

3. DNA-viruses

4. Adenoviruses Non-enveloped DNA virus 70-90 nm in size Linear ds DNA genome with core proteins

6. Adenovirus- Properties • Stable in the environment • Relatively resistant to disinfection (Alcohol, chlorhexidine, detergents) • Stable in GI tract- can withstand low pH, bile acids and proteolytic enzymes

7. Dodecon: Hemagglutinin made up of 12 pentons with their fibers.

8. ICOSAHEDRAL CAPSID • A polyhedron with 20 equilateral faces and 12 vertices • capsomers • ring or knob-shaped units made of 5 or 6 protomers • pentamers (pentons)– 5 subunit capsomers • hexamers (hexons)– 6 subunit capsomers

9. Adenoviral proteins • structural • non-structural • According to the time of synthesis in the cell: • early • late • They are differed according to their physical and chemical properties, antigenic specifity. There are capsid and inner proteins. 12 polypeptides (m.w. - 7 500-120 000 D) are identifyded.

12. ADENOVIRUS - Classification Subgroups- 6 subgroups (A-F), based on hemagglutination Serotypes- 1-49 (human) Common serotypes:- 1-8, 11, 21, 35, 37, 40 Enteric Adenoviruses belong to subgroup F

13. Human Adenoviruses Types

16. Adenoviruses in the cells

17. Pathogenesis and Replication Infects mucoepithelial cells of respiratory, GI and GU tracts Enter via epithelium, replicate and spread to lymphoid tissue Viremia occurs Secondary involvement of viscera

18. Pathogenesis and Replication • Fiber protein determines target cell specificity and attachment • Viral DNA enters host cell nucleus • Early and late phases of replication • Error-prone process • Inclusion bodies in nucleus

19. Adenovirus-Host Cell Interaction

20. EPIDEMIOLOGY • Endemic, epidemic and sporadic infections • Many infections are sub-clinical Outbreaks: Military recruits ( 10% basic trainees in 1st week) swimming pool users, hospitals, residential institutions, day care settings

21. TRANSMISSION Droplets Fecal-oral route Direct and through poorly chlorinated water Fomites

22. CLINICAL SYNDROMES Respiratory Eye Genitourinary Gastrointestinal Others

23. Acute Respiratory Disease • Fever • Tracheobronchitis • Pneumonia • Children and adults • Epidemics in military recruits • Types 4 and 7 most frequently

24. Adenoviral serotypes and associated diseases Remaining serotypes are infrequently isolated or not clearly associated with disease. * Association with gastroenteritis not as firmly established as with types 40 and 41.

25. Adenoviral diseases according to patient population

26. Pharyngoconjunctival fever • Headache, fever, malaise • Conjunctivitis and Pharyngitis • Cervical adenopathy, rash and diarrhea also • Main adenovirus types: 3, 4, 7, 14 • Epidemics in summer months • Contaminated water in swimming pools, • fomites

27. Adenoviral Infections of the eye • Epidemic Keratoconjunctivitis (EKC) • Acute follicular conjunctivitis • Pharyngoconjunctival fever Early conjunctivitis (left) and Bilateral conjunctivitis (right)

28. Epidemic Keratoconjunctivitis • Incidence in summer • Types 8, 19, 37 • Outbreaks- in situations of close contact (e.g., schools, hospitals, camps, nursing homes, workplaces) • Spread via droplets and contaminated water (ophthalmologic solutions and equipment, swimming pools), fomites, hands

29. SYMPTOMS Pink/red eye Irritation, tearing, foreign-body sensation Ocular pain Photophobia Fever, malaise Respiratory symptoms SIGNS Conjunctival injection, ecchymosis Corneal injection (limbus) Diffuse→focal epithelial keratitis ↓Visual acuity (subepithelial corneal opacities) Ipsilateral pre-auricular lymphadenopathy EKC-Clinical features

30. ADENOVIRAL INFECTIONS -Genitourinary system Acute hemorrhagic cystitis • fever, dysuria, hematuria • Types 11, 7, 4, 21, 1 • More common in boys Others • Orchitis, nephritis, cervicitis with ulcerated vesicular lesions, urethritis • Types 2, 8, 19, 37

31. Other Infections due to Adenovirus Myocarditis Pericarditis Meningitis Rash Arthritis

32. Adenovirus infections in Immunocompromised hosts • Disseminated, severe and often fatal infections • Due to new infection or reactivation of latent virus • Prolonged infections with prolonged viremia and viral shedding • Necrotizing pneumonia, hepatitis, rash, DIC, CNS involvement

33. DIAGNOSIS OF ADENOVIRAL INFECTIONS • Variety of clinical specimens depending on clinical syndrome-NP, conjunctival, stool, urine, tissue, etc. • Transport in viral transport media • Isolation from pharyngeal/nasal site within 3 days of symptom onset ( 3 weeks for EKC)

34. Methods for ADV diagnosis • Culture in HeLa, HEK cell lines • Shell vial cell culture • DFA/EIA insensitive except types 40, 41 • PCR, nucleic acid probes esp. myocarditis • EM and Immune EM • Histology characteristic intranuclear inclusions • Serology serum titer corresponding to culture isolate Diagnosis-Enteric adenoviruses • Isolation requires special media-Graham 293 • ELISA for rapid detection is available

35. Therapy for ADV Infections • Antiviral Cidofovir – limited data • Immunologic Pooled immunoglobulin esp. pediatric – associated serotypes Activated T cell infusion – anecdotal

36. ADENOVIRUS VACCINE • Oral live attenuated vaccine • Strains 4, 7 • Used in military recruits • Manufacture of vaccine was halted in 1996 • Lapse in immunization was associated with outbreaks in military recruits

37. Herpesvirus Family • There are about 80 herpesviruses. • Herpes simplex virus 1, • Herpes simplex virus 2, • Cytomegalovirus, • Herpes zoster virus-Varicella virus), • Epstein-Barr virus, • Herpesvirus 6, • Herpesvirus7. 8 • Viruses can be isolated from cows, pigs, hens

38. All herpesviruses have a core of double-stranded DNA surrounded by a protein coat that exhibits icosahedral symmetry and has 162 capsomeres. The nucleocapsid is surrounded by an envelope. The enveloped form measures 150-200 nm; the "naked" virion, 100 nm. The double-stranded DNA (MW 85-150xlO6) has a wide range of guanine + cytosine content in different herpesviruses, There is little DNA homology among different herpesviruses, except her­pes simplex types 1 and 2.

39. Herpesviruses

40. Classification • Three subfamily: • (Alphaherpesvirinae), • (Betaherpesvirinae), • (Gammaherpesvirinae) • Alphaherpesvirinae: a lot of hosts, short reproductive cycle, effective cells (infected ones) destroying, latent form of existence in ganglia. • Simplexvirus (HSV-1, HSV-2) і Poikilovirus.

41. Betaherpesvirinae: • Limited spectrum of hosts, reproductive cycle is long. • Infected cells increase their sizes, formation of persistence infections in cell cultures. Virus exist in latent form in limphoreticular cells, secretory glands, kidneys and so on. • Genera: • Cytomegalovirus • Muromegalovirus (mice cytomegalovirus)

42. Gammaherpesvirinae (EBV, HV-6, 7, 8 MDV): In vitro viruses replicate in liphoblast cells, cause lytic infection in epithelioid cells fibroblasts. Viruses have tropism both Т-, and В-lymphocytes, but as a rool infection process is stopped at prelytic stage, so productive cases are absent.

43. HERPES SIMPLEX (Human Herpesvirus 1 and 2) (Herpes labialis, Herpes genitalis, and many other syndromes). Infection with herpes simplex virus (herpesvirus hominis) may take several clinical forms. The infection is most often inapparent. The usual clinical man­ifestation is a vesicular eruption of the skin or mucous membranes. Infection is sometimes seen as severe keratitis, meningoencephalitis, and a disseminated illness of the newborn. Properties of the Virus. The envelope is derived from the nuclear membrane of the infected cell. It contains lipids, carbohydrate, and protein and is removed by ether treatment. The double-stranded DNA genome is linear (MW 85-106 x 106).

44. Types 1 and 2 show 50% sequence homology. Treatment with restriction endonucleases yields characteristically different cleavage patterns for type 1 and 2 viruses and even for different strains of each type. This "fingerprinting" of strains allows epidemiologic tracing of a given strain, whereas in the past, the ubiquitousness of herpes simplex virus made such investigations impossible.

45. Herpesvirus. Several proteins have been identified in the virion, The protein I is associated with the viral capsid; the glycoproteins present in bands 0, 2 -3, 8, and 9 (glycoproteins) are associated with the envelope; and a DNA-binding protein (band number 13) is associated with the internal core.

46. Chorionallantoic membrane (right) infected with Herpesvirus

47. The plaques produced by herpesvirus type 2 are larger than the tiny plaques produced by type 1 virus. The virus grows readily and produces plaques in almost any cell culture. Infected cells develop inclusion bodies and then undergo necrosis (cytopathic effect). In Chinese hamster cells, which contain 22 chromosomes, the virus causes breaks in region 7 of chromosome No. 1 and in region 3 of the X chromosome. The Y chromosome is unaffected. Viral cytopathogenic effect (right)

49. Differentiation of Types 1 and 2 Herpes simplex virus types 1 and 2 cross-react serologically but may be distinguished by a number of tests: (1) The use of type-specific antiserum prepared by adsorption of the viral antiserum with heterotypically infected cells or by inoculation of rabbits with individual type-specific proteins. (2) The greater temperature sensitivity of type 2 infectivity. (3) Preferential growth in different cell species. (4) Restriction enzyme patterns of virus DNA molecules. (5) Differences in the polypeptides produced by type 1 and type 2. Oncogenic Properties: After inactivation of their lytic capabilities by ultraviolet irradiation or other means, herpesvirus types 1 and 2 can cause transformation of cultured hamster cells, which may induce tumours when inoculated into newborn hamsters. Viral genetic information can be demonstrated in the tumour cells.

50. Herpes Simplex Virus • HSV is spread by contact, as the virus is shed in saliva, tears, genital and other secretions. • Primary infection is usually trivial or subclinical in most individuals. It is a disease mainly of very young children ie. those below 5 years. • About 10% of the population acquires HSV infection through the genital route and the risk is concentrated in young adulthood. • Following primary infection, 45% of orally infected individuals and 60% of patients with genital herpes will experience recurrences. • The actual frequency of recurrences varies widely between individuals. The mean number of episodes per year is about 1.6.