Gram Negative Bac Flashcards
Encapsulated
Ferments maltose and glucose
N. meningitidis
Insignificant capsule
Ferments glucose only
N. gonorrhea
culture-negative subacute bacterial endocarditis
Eikenella corrodens and Kingella kingae
Enriched chocolate agar
Polyribitol Phosphate capsule
Haemophilus
Borget-Gengou Agar
Regan-Lowe medium
Whooping cough
Bordetella pertussis
Poorly gram staining
Silver stain
Charcoal yeast agar
AIrconditioning
Legionella
Lactose fermenters - Fasy
Green sheen
E. coli
Lactose fermenters
Urease positive
ESBL
Klebsiella
Comma-shaped
Microaerophilic
Skirrow’s agar
Campylobacter
Comma-shaped
Urease positive
Microaerophilic
H. pylori
Motile
Oxidase negative
H2S producer
Salmonella
Non-motile
Oxidase negative
H2S non-producer
Shigella
Swarming
Oxidase negative
H2S producer
Proteus mirabilis
Oxidase positive
H2S non-producer
Obligate aerobe
Pseudomonas
High carriage rate in CLOSE QUARTERS:
Military recruits
Dormitories
Camps
N. meningitidis
Ferments both MALTOSE and GLUCOSE
N. meningitidis
Oxidase-positive colonies on chocolate agar
N. meningitidis
Grows best in high
CO2 environment
N. meningitidis
associated with epidemics of meningitis
N. meningitidis serotype A,B,C
causes blood vessel destruction
(hemorrhage) and sepsis
Endotoxin (LPS)
cleaves IgA
IgA protease
Have unique proteins that can extract iron from transferrin, lactoferrin and hemoglobin
N. meningitidis
allow attachment to human nasopharyngeal cells and undergo antigenic variation to avoid attack by the immune system
Pili
MENINGITIS:
most common cause among aged 2-18 yrs
N. meningitidis
dissemination of meningococci into the bloodstream
multiorgan disease
consumptive coagulopathy
petechial or purpuric rash (purpura fulminans)
Meningococcemia
most severe form of meningococcemia
Waterhouse - Friderichsen Syndrome
adrenal insufficiency bilateral hemorrhagic destruction of the adrenal glands
Waterhouse - Friderichsen Syndrome
DOC for the treatment of meningococcal meningitis and septicemia
Ceftriaxone/ Cefotaxime
prophylaxis
of close contacts of
infected persons in meningococcemia
Rifampin/ Ciprofloxacin
contains capsular polysaccharide of strains ________________ coupled to a carrier protein (diphtheria toxoid) to enhance immunogenicity
W 135, A, C,Y
bean-shaped diplococcus
N. meningitidis
Cell wall contains cytochrome oxidase which oxidizes dye tetramethylphenylene diamine from colorless to deep pink
C. meningitidis
Culture media for Neisseria Selective media:
prevents growth of
bacteria
C. meningitidis
(+) in Meningococci
(-) in Gonococci
Polysaccharide capsule and Vaccine
Facultative-anaerobe
Ferments GLUCOSE only
Oxidase-positive
Grows best in high
CO2 environment
N. gonorrhea
Adherence to epithelial cells
Antigenic variation
Antiphagocytic, binds bacteria tightly to host cell protecting it from phagocytosis
Pili
promote
invasion into epithelial cells
Outer Membrane Porins
Adherence and invasion, Opaque colonies
Opa proteins
Endotoxin: lipooligosaccharide (LOS)
N. gonorrhea
- urethritis and epididymitis in men
N. gonorrhea
- most common cause of urethritis
N. gonorrhea
- in women, which can progress to pelvic inflammatory disease (PID)
N. gonorrhea
Complication of PID: violin-string adhesions
Fitz-Hugh-Curtis Syndrome
- the most common cause of septic arthritis in sexually active individuals
N. gonorrhea
- purulent conjunctivitis in newborns (Opthalmia neonatorum)
N. gonorrhea
DOC N. gonorrhea
Ceftriaxone plus Doxycycline (to cover for Chlamydia trachomatis – usual co-infection))
to prevent ophthalmia neonatorum
Erythromycin
Kidney bean-shaped doughnut
Gram-negative diplococci
N. gonorrhea
most common cause of hyperacute
bacterial conjunctivitis
N. gonorrhea
Most common site of asymptomatic gonococcal infection in women:
Endocervix
Satellite growth around S. aureus colonies
Haemophilus influenza
requires two factors for growth (both found in blood):
X factor: Hematin
V factor: NAD+
Haemophilus influenza
Most virulent type of Influenza
HiB
Most serious manifestation of Hib infection
Encapsulated Haemophilus influenza meningitis
Complications: sensorineural hearing loss (6%), mental retardation, seizure, deafness, and death
Encapsulated Haemophilus influenza meningitis
Most common cause of acute epiglottitis
HiB
Bucal, Periorbital Cellulitis
Haemophilus influenza
DOC Haemophilus Influenza
Amoxicillin +/− clavulanate - mucosal infections
Ceftriaxone - Meningitis
Otitis Media in Children
Moraxella
DOC Moraxella
Azithromycin or Clarythromycin
High CO2
Neiserria spp, Haemophilus
Positive Quellung
Haemophilus influenza (with Strep pneumo)
pili rod that extends from the surface of B. pertussis, enabling the bacteria to bind to ciliated epithelial cells of the bronchi
mediates attachment
Filamentous Hemaglutinin
causes ADP ribosylation activates G proteins that increases cAMP resulting in: - sensitivity to histamine - insulin release - number of lymphocytes in blood
Pertussis Toxin
“weakens” neutrophils lymphocytes and monocytes
inhibits phagocytosis
Extracytoplasmic Adenylate cyclase
kills ciliated epithelial cells
paralyze cilia
causes whooping
Tracheal cytotoxin
Most contagious phase of Whooping cough
Catarrhal phase
Phase wherein antibiotics is most effective
Catarrhal Phase
Culture Media: Bordatella pertussis
Bordet gengou
Regan Lowe
Calcium alginate swab
B. pertussis
Freshwater amoebae appear to be the natural reservoir for the organisms.
Legionella
Airconditioning
Legionella
L cysteine and iron
Legionella
Charcoal Yeast Agar
Legionella
Optimal Temp 28 C - 40 C
Legionella
Facultative intracellular parasite
Legionella
Cu-Zn superoxide dismutase and catalase-peroxidase
Legionella
RNAase, phospholipase A and phospholipase C
Legionella
Endotoxin is sole virulence factor
Legionella
Pontiac River Disease
Legionella
Atypical pneumonia
Legionella
DOC Legionella
Azithromycin
Levofloxacin
Doxycycline
Silver Stain
Legionella
Urine Serotype 1
L. pneumophilia serogroup 1
Lactose-fermenting colonies on EMB or MacConkey’s agar
E. coli
Green metallic sheen on EMB agar
E coli
TSI (Triple Sugar Iron) agar shows acid slant and acid butt with gas but no H2S
E. coli
Fimbriae (pili): attachment/ colonization factor; causes cystitis and pyelonephritis
E coli
Capsule (K-antigen): causes pneumonia
E coli
Siderophore: obtains iron from human transferrin or lactoferrin
E coli
Endotoxins
Lipid A portion of lipopolysaccharide (LPS)
Causes septic shock
E coli
LT (heat-labile):
increases cAMP (same as cholera toxin)
E coli