Micriobiology Flashcards
What is paramyxovidrae
Viruses with single stranded RNA genome
Antisense strand orientation
Measles viruses are causes by
A maculopapular rash= rubeola
Structure of the measles virus
Large virüse
Negative sense single stranded RNA GENOME
peomorphic envelope
Proteins NP- P- L -M
Envelope contains 2 glycoproteins- F an attachment p
Mumps and measles binding
HN of mumps virus binds sialic acid and has hemaglutitinin and neuramindase activaty
H of measles virus binds to protein receptors and is Also hema glutinin
Disease mechanism of measles virus
Infect the epithelial cells of respiratory tract
Spread via viremia
Replicated in eyes RT UT LS BV CNS
RASH HAS LIFELONG IMMUNUTY
CELL MEDIATED IMMNUnity is essential to control infection
Complications of measles
Posinfectious encephalitis
Measles encephalitis
Subacute sclerosing pan encephalitis SSPE
Symptoms of measles
Conjunctivitis Cory a cough
Photophobia
Koplik spots
Exanthem
High fever
Barking cough
Rash
What is mumps virus
Acute benign viral parotitis closely related to parainfluenza virus 2
Disease mechanism of mumps
Virus infest the epithelial cells of respiratory tract
Spread by viremia
Infection paramos gland
Spread to testes ovary thyroid and CNS- 50% meningitis’s
What is the vaccine for mumps and measles
MMR
1st dose in 12-15. Months
2nd şose - 4-6 years
What is a rubella virus
Little red German measles
Positive single stranded RNA virüse
Only member of rubivirus group
Has severe congenital defects
Congenital clinical syndromes of rubella
Most severe outcome
Fetus major risk
Most common manifestation cataracts growth retardation cardiac abnormalities mental retardation deafness
Difference between rubeola and rubella
RUBEOLA
- CCC
- HIGH FEVER
-KOPLIK SPOTS ON BUCAK,A MUCOSA
—RASH appears at the hairline
RUBELLA
- HEADACHE
LOW GRADE FEVER
SORE THROAT
CORYZA
FORCHHEIMER SPOTS IN SOFT PALATE
LYMPHOADENOPATHY
RASH BEGINS ON THE FACE
The Smallest of the DNA viruses are
PARVOVIRIDAE
Liner single stranded DNA genome
Noneenveloped
Which parvocirises cause human disease
B19 and bocavirus
Replication of B19
Erythroid lineage
Pathogenisis of parvovirus
Spreads by RES and oral secretions
Infect mitotically active precursor cells in bone marrow
Results in erthematius maculopaular rah arthralgia and arthritis
Cause aplastic crises in person with chronic anemia
Clinical syndromes
Mild flulike illness
In children- slapped cheek erythema infectiosum
Adults-polyarthritis
Chronic anemia- aplastic crisis
Pregnant women-hydros fetalis
Note there ks not evidence that B19 causes congenital abnormalities
What are the three types of fungal infections of the skin
1- superficial mycosis( yeast or mold
2- cutaneous mycosis
3- subcutaneous mycosis
Superficial mycosis
Fungal infection of the stratum corneum layer
No pathological changes
Do not elicit immune system
Infection of superficial mycosis
1- pityriasis= malassezia furfur
2- tinea nigra= hortaea werneckkii
3- back Piedra = piedraia hortae
4- white piedra= trichosporon beigelii
Pityriasis tinea
Common superficial fungal infection
Malassezia furfur causes lipophilic yeast
Small hypo or hyper pigmented macules
In the upper trunk arms shoulder face and neck
Malassezia furfur produces clusters and clumps of short hyphae often called as spaghetti and meatballs
Tinea Nigra
A fungal infection with dark pigmented macules with irregular,edges
Black fungus- hortea werneckki
May resemble a malignant melanoma
White piedra
Infection of hair causes by yeastlike fungi of the genus trichisporon
In microscopic examination reveals hyphal elements, arthroconidia and budding yeast cells
