Microbiology Flashcards
Adenovirus
Very common cause of Rhinitis (common cold) or bronchitis
DNA group I
Most common cause of Rhinitis?
Rhinovirus #1
Adenovirus
Coronavirus
Rhinovirus
Most common cause of rhinitis (common cold) or bronchitis -RNA class IV
Coronavirus
Common cause of Rhintitis -RNA class IV
Most common cause of sinusitis?
Viral but predisposes pts for bacterial - then Strep pneumoniae or H influenza
Failed Abx Aspergillus fumigatus
Strep Pneumonae
Common cause of bacterial sinusitis. Most common cause of Pneumonia*** Gram positive cocci Catalase neg Alpha hemolytic Bile Esculin neg Optochin susceptable
Haemophilus Influenzae
Common cause of bacterial sinusitis.
Gram Neg
Streptococcus Pyogenes. Common infections. Virulence factors. Tests.
Most common cause of bacterial pharyngitis
Gram Pos cocci
Catalase Neg (will NOT bubble with H2O2 like Staph)
Peroxidase Pos
Beta hemolytic
Bacitracin sensitive
Can progress to Rheumatic fever or glomerularnephritis
Virulence: M protein, FNBP, hyaluronic acid prevents phagocytosis, to invade: protease and hyaluronidase)
Test: rapid antigen used clinically*, can send to culture which is more accurate but takes a couple days.
Strep Pyogenes if infected by bacteriophage?
Scarlet Fever
Lysogenized bacteriophage has genes that encode super antigen toxins**
Streptococcal pyogenic exotoxins: SpeA, SpeB, SpeC and Spe F.
“strawberry tongue”
Corynebacterium Diptheriae.
Bacteria that causes Diptheria
secretes A-B exotoxin (B part is binding, A part inhibits EF2 which is required for translation - cell dies)
Treat with antibiotic and anti-toxin
Gram Pos Bacilli*
Grows on potassium tellurite culture and will turn BLACK (elemental tellurium)
Most common causes of Croup?
Parainfluenza virus is most common
Influenza virus and RSV during winter and early spring.
Parainfluenza Virus
Most common cause of Croup or bronchitis in children** RNA class V
Respiratory Syncytial Virus (RSV)
Most common cause of BRONCHIOLITIS in infants less than one year***
A cause of Croup during winter and early spring.
RNA Class V
F proteins on surfae of virus cause cell membranes to FUSE causing Giant multinucleate cells in lungs of children infected with RSV
Influenza Virus
A cause of Croup in children in winter or early spring
RNA Class V
SEGMENTED
Influenza A,B,C
8 pieces of single stranded RNA - very high rates of mutation*** (RNA polymerase do not have a self check mechanism so many random mutations ensue) (antigenic drift)
The segmented portions can swap between strains of same virus if single cell is infected with both strains (antigenic shift)
Binds to host neurimidase with VIRAL neurimidase receptor - host usually mounts immune response to neurimidase receptor which is a problem because it can mutate very easily
Bordetella Pertussis
Causes Pertussis
Gram Neg Coccobacilli
Grows on Bordet-Gengou Agar
Has Pertussis AB toxin that is toxic to cilia in resperatory tract
