bohomolets microbiology lecture #13
DESCRIPTION
By Ms. Kostiuk from Microbiology departmentTRANSCRIPT
PicornavirusesPicornaviruses
Enteroviruses Enteroviruses
Family -Family - PicornaviridaePicornaviridae
Pico – small Pico – small , , RNA – ribonucleic acid RNA – ribonucleic acid
P – polioviruses P – polioviruses I – insensitivity to etherI – insensitivity to ether C – coxsackieC – coxsackie O – orphan O – orphan R – RNA R – RNA N – new typesN – new types A - animalA - animal
Virions of picornavirusesVirions of picornaviruses
Family Family Picornaviridae Picornaviridae (modern classification, (modern classification, 2003 р.2003 р.))
Genus:Genus:
EnterovirusEnterovirus
Rhinovirus Rhinovirus
Cardiovirus Cardiovirus
Aphthovirus Aphthovirus
HepatovirusHepatovirus
Parechovirus Parechovirus
Erbovirus Erbovirus
Cobuvirus Cobuvirus
Common hostCommon host
Human Human
Human Human
Animal Animal
Animal Animal
HumanHuman
Human Human
Animal Animal
Human Human
Picornaviruses Picornaviruses
Icosahedral
Nonenveloped viruses
Small - diameter 20-30 nm
Cubical type of symmetry
Genome – single-stranded linear RNA
RNA has positive polarity
5’ end of RNA has a protein that serves as a primer for transcription by RNA polymerase
Coxsackievirus virions Coxsackievirus virions
Structure of picornavirusesStructure of picornaviruses ((schemescheme))
60 capsomers (protomers) 5 virus proteins:
(VP1, VP2, VP3, VP4 are contained in capsomers),
VPg is bound with virus RNA
Capsomer of picornavirusCapsomer of picornavirus
Scheme of virus proteins formationScheme of virus proteins formation
Scheme of RNA replication Scheme of RNA replication
Assembly of the picornaviral virionAssembly of the picornaviral virion
Formation and assembly of capsid proteins
Procapsid
Viral RNA
Provirion
Finishing of virion proteins formation
Matured virion
Different properties of enteroviruses, Different properties of enteroviruses, hepatoviruses and rhinoviruseshepatoviruses and rhinoviruses
Property Property Entero-Entero-viruses viruses
Hepato-Hepato-virusvirus
Rhino-Rhino-virusesviruses
Primarily infected Primarily infected tissue tissue
Enteric Enteric tract tract
Enteric Enteric tract tract
Upper Upper respiratory respiratory tract tract
Optimal temperature Optimal temperature of replication of replication
3737OOCC 3737OOCC 333300CC
Stableness under acid Stableness under acid conditions (pH3-5)conditions (pH3-5)
Yes Yes Yes Yes No No
Diseases Diseases Hepatitis Hepatitis AA
Rhinitis, Rhinitis, respiratory respiratory infection infection
Modern classification of Modern classification of enteroviruses enteroviruses
Species Species Past name Past name
Polienterovirus (PEV)Polienterovirus (PEV) Polioviruses 1, 2, 3 typesPolioviruses 1, 2, 3 types
Human enterovirus A Human enterovirus A (HEV-A)(HEV-A)
CoxsackieCoxsackie А А typestypes 2-8, 10, 12, 14, 16; 2-8, 10, 12, 14, 16;
Enterovirus Enterovirus 71 71
Human enterovirus BHuman enterovirus B (HEV-B)(HEV-B)
CoxsackieCoxsackie А-9, А-9, CoxsackieCoxsackie В В typestypes 1-6, 1-6,
ЕСНО ЕСНО typestypes 1-7,9,11-21,24-27, 29-33; 1-7,9,11-21,24-27, 29-33; Enterovirus 69 Enterovirus 69
Human enterovirus CHuman enterovirus C (HEV-C)(HEV-C)
CoxsackieCoxsackie А А typestypes 1,1, 11,11, 13,13, 15,15, 17-22, 17-22, 24 24
Human enterovirus DHuman enterovirus D (HEV-D)(HEV-D)
EnterovirusEnterovirus 68,70 68,70
Polioviruses Polioviruses
Polioviruses Polioviruses
Diseases caused by enterovirusesDiseases caused by enteroviruses
Viruses Viruses Disease Disease Symptoms Symptoms
Polioviruses Polioviruses PoliomyelitisPoliomyelitis Paralysis Paralysis
Coxsackie-Coxsackie-viruses A viruses A (CAV)(CAV)
HerpanginaHerpangina Fever, sore throat and tender Fever, sore throat and tender vesicles in the oropharynxvesicles in the oropharynx
Hand-foot-and- Hand-foot-and- mouth diseasemouth disease
Vesicular rash on the hands Vesicular rash on the hands and feet and ulceration in the and feet and ulceration in the mouthmouth
Coxsackie-Coxsackie-viruses B viruses B (CBV)(CBV)
Pleurodynia Pleurodynia Fever and severe pleuritic-Fever and severe pleuritic-type chest paintype chest pain
Myocarditis, Myocarditis, pericarditispericarditis
Fever, chest pain, and signs Fever, chest pain, and signs of congestive failureof congestive failure
Both CAV and Both CAV and CBVCBV
Aseptic meningitis, mild paresis and Aseptic meningitis, mild paresis and transient paralysis. Upper respiratory transient paralysis. Upper respiratory infections and minor febrile illness with or infections and minor febrile illness with or without rash.without rash.
Poliomyelitis in an ancient Poliomyelitis in an ancient civilizationcivilization
Poliomyelitis is an acute enteroviral infection of the spinal cord that can cause neuromuscular paralysis.
Characteristic of poliovirus Characteristic of poliovirus infectionsinfections
Inapparent (asymptomatic) infection.Inapparent (asymptomatic) infection. 99% 99% cases cases
Abortive poliomyelitis.Abortive poliomyelitis. Mild, febrile illness with Mild, febrile illness with headache, sore throat, nausea, and vomiting.headache, sore throat, nausea, and vomiting.
Nonparalytic poliomyetitis. Nonparalytic poliomyetitis. Aseptic meningitis with Aseptic meningitis with fever, headache, and a stiff neck.fever, headache, and a stiff neck.
Paralytic poliomyelitis.Paralytic poliomyelitis. Flaccid paralysis is the Flaccid paralysis is the predominant finding but brain stem involvement can lead predominant finding but brain stem involvement can lead to life-threatening respiratory paralysis. Painful muscle to life-threatening respiratory paralysis. Painful muscle spasms occurs. The motor nerve damage is permanent.spasms occurs. The motor nerve damage is permanent.
Clinical findings of poliomyelitis Clinical findings of poliomyelitis
Clinical findings of poliomyelitisClinical findings of poliomyelitis
Viruses Viruses ЕСНО ЕСНО Е – Е – entericenteric C – cytopatogenicC – cytopatogenic H – humanH – human O - orphanO - orphan
Disease:
Aseptic meningitis
Upper respiratory infection
Febrile illness with and without rash
Infantile diarrhea
Hemorrhagic conjunctivitis
Scheme of enterovirus Scheme of enterovirus pathogenesispathogenesis
Diagnosis of enteroviral infectionDiagnosis of enteroviral infection
Isolation the viruses in cell culture Isolation the viruses in cell culture and suckling mice (for Coxsackie A and suckling mice (for Coxsackie A viruses) and identification in viruses) and identification in neutralization test with specific neutralization test with specific antiserum antiserum
Testing serum samples (from Testing serum samples (from patient) for observing a rise in titer of patient) for observing a rise in titer of antiviral antibodyantiviral antibody
CPE caused by polioviruses CPE caused by polioviruses
Native Vero cells CPE – full destruction of cell monolayer after virus multiplication
Differentiation of enteroviruses Differentiation of enteroviruses
Virus Virus CPE in cell CPE in cell culture culture
Paralysis in Paralysis in newborn micenewborn mice
Polioviruses Polioviruses ++ ++
CoxsackieCoxsackie А А ++ + (+ (flaccidflaccid))
CoxsackieCoxsackie В В ++ + (+ (spastic spastic ))
ЕСНОЕСНО ++ --
Diagnosis of CoxsackievirusDiagnosis of Coxsackievirus infection infection
Native suckling mice
Mouse with flaccid paralysis of back extremities
Mice is affected by virus
Flaccid paralysis in newborn mice caused by Coxsackievirus A 10
Prevention of poliomyelitisPrevention of poliomyelitis
IPVIPV - inactivated (killed) vaccine - inactivated (killed) vaccine (made by Salk in 1954). (made by Salk in 1954).
IPV is inactivated by formalin IPV is inactivated by formalin
OPV OPV – attenuated (live), oral vaccine – attenuated (live), oral vaccine (made by Sabin in 1955-1958).(made by Sabin in 1955-1958).
OPV is made using selection technology OPV is made using selection technology
Both OPV and IPV Both OPV and IPV contain 3 serologic contain 3 serologic typestypes. .
Important features of poliovirus Important features of poliovirus vaccinesvaccines
Attribute Attribute Killed Killed (Salk)(Salk)
Live Live (Sabin)(Sabin)
Prevents diseasePrevents disease Yes Yes Yes Yes
Interrupts transmission Interrupts transmission No No Yes Yes
Induces humoral immunity (IgG)Induces humoral immunity (IgG) Yes Yes Yes Yes
Induces local intestinal immunity Induces local intestinal immunity (IgA)(IgA)
No No Yes Yes
Affords secondary protection by Affords secondary protection by spread to othersspread to others
No No Yes Yes
Important features of poliovirus Important features of poliovirus vaccinesvaccines
Attribute Attribute Killed Killed (Salk)(Salk)
Live Live (Sabin)(Sabin)
Interferes with replication of Interferes with replication of virulent virus in gutvirulent virus in gut
No No Yes Yes
Reverts to virulence Reverts to virulence No No Yes Yes
Can cause disease in the Can cause disease in the immunocompromisedimmunocompromised
No No Yes Yes
Route of administration Route of administration Injection Injection Oral Oral
Requires refrigerationRequires refrigeration No No Yes Yes
Duration of immunityDuration of immunity Shorter Shorter Longer Longer
Spread of virulent polioviruses in Spread of virulent polioviruses in 19881988
Spread of virulent polioviruses in Spread of virulent polioviruses in 19981998
Methods of laboratory Methods of laboratory diagnosis of infectious diagnosis of infectious
diseasedisease
Laboratory diagnosisLaboratory diagnosis. . GoalsGoals::
Diagnostics of disease – definition of Diagnostics of disease – definition of infection disease etiology infection disease etiology
Control of disease development Control of disease development Choosing of adequate individual therapy Choosing of adequate individual therapy Estimation of effectiveness of treatment Estimation of effectiveness of treatment Detection of donor blood or organ Detection of donor blood or organ
contamination contamination Control of epidemic development Control of epidemic development
Materials for laboratory Materials for laboratory diagnosisdiagnosis
Blood Blood –– influenza, AIDS influenza, AIDS
Spinal liquid Spinal liquid – – viral and bacterial viral and bacterial meningitis meningitis
UrineUrine – – genitourinary infections genitourinary infections
Feces Feces – – enteroviral infection, choleraenteroviral infection, cholera
Material from wound, pus Material from wound, pus
Sputum Sputum – – respiratory infections respiratory infections (rhinoviral infection) (rhinoviral infection)
Methods of laboratory Methods of laboratory diagnosticdiagnostic
Direct Direct – – to reveal to reveal presence of agent presence of agent (microorganism) or (microorganism) or its components in its components in patient organismpatient organism::
Microscopy Microscopy Cultivating methodCultivating method Biological method Biological method Indication of microbial Indication of microbial
antigens antigens Gen diagnosisGen diagnosis
Indirect Indirect – – to detect to detect response of human response of human organism to agent organism to agent (microorganism) (microorganism) ::
Serological diagnosis Serological diagnosis Histological assay Histological assay Allergic assay Allergic assay
Microscopy Microscopy
NegativeNegative Only presumptive Only presumptive diagnose diagnose
Non universal Non universal
Low sensibility Low sensibility
Positive:
Rapid
In early stage of disease
Simple
Based on microscopic identification the morphological and structural features of microorganisms directly in the specimen from patient
Some disease that can be Some disease that can be diagnosed by microscopydiagnosed by microscopy
Acute gonorrhea Acute gonorrhea Meningococcal meningitis Meningococcal meningitis Primery syphilis Primery syphilis Первинного сифілісуПервинного сифілісуRotaviral infectionRotaviral infectionRelapsing feverRelapsing fever
Microscopy diagnosis of Microscopy diagnosis of relapsing fever relapsing fever
Blood, stained with Romanowsky-Giemsa method
Microscopy diagnosis of Microscopy diagnosis of rotaviral infectionrotaviral infection
• Electron Electron microscopymicroscopy
Microbiologic diagnosis Microbiologic diagnosis ((cultural methodcultural method))
Method is based on obtaining a pure culture of Method is based on obtaining a pure culture of microorganisms from the patient material and microorganisms from the patient material and next identification the culture to speciesnext identification the culture to species
The most exact, permit to make final diagnosis
In early stage of disease Give possibility to choose
antimicrobial treatment
May be used different system for cultivation of microorganisms (for instance, nutrient medium for bacteria and cell culture for viruses)
Some microorganisms can not be cultivated and isolated in pure culture
Long time for examination and making the diagnosis