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
ST (heat-stable)
Increases cGMP
E coli
inhibits protein synthesis by inactivating the 60S subunit of eukaryotic cells (E. coli O157:H7, STEC, EHEC)
Shiga like toxin
- releases LT and ST toxins
- traveler’s diarrhea (watery)
ETEC
- Watery diarrhea of long duration
- Mostly in infants, often in developing countries
- Flattens villi prevents absorption
EPEC (Plattens)
- Bloody diarrhea
- with pus in the stool and fever
EIEC
E coli UTI DOC
Ampicillin/ Sulfonamides
E coli meningitis and sepsis
3rd Gen cephalosporins
Typing by O and H antigens
E coli (e.g. EColi O157:H7)
Microangiopathic hemolytic anemia
HUS
Invades submucosa of intestinal tract (distal ileum and colon), but not the lamina propria
Shigella
Invasion of M cells is key to pathogenicity.
Shigella
inactivates the 60S ribosome, inhibiting protein synthesis and killing intestinal epithelial cells
Shiga toxin
Fever and abdominal cramps diarrhea (initially watery then bloody)
Bacillary dysentery
DOC Shigella
Ciprofloxacin
Culture Media for Shigella
XLD
4Fs of Shigella Transmission:
Finger Food Feces Flies
Produces H2S
Non-lactose fermenter
Salmonella
Vi Antigen
Salmonella - protects from intracellular killing
Stepwise Fever
Typhoid week 1
Rose Spots
Typhoid week 2
Bleeding ileitis
Typhoid week 3
Gold standard for the diagnosis of typhoid fever
Bone Marrow Culture
Commonly seen in patients with sickle cell anemia or cancer
S. choleraesuis
DOC Salmonella
Amoxicillin
Chloramphenicol
TMP-SMX
Widal Test
Salmonella
Predilection for invasion of the gallbladder
Typhoid Fever
Organisms enter, multiply in Peyer’s patches, and then spread to RES
Typhoid fever
Contaminated raw seafood
V. parahemolyticus
Trauma to skin, especially in shellfish handlers,
V. vulnificus
Shooting Star motility
Vibrio
digest mucous layer so V. cholerae can attach to cells
Mucinase
like LT of E. coli, acts by ADP ribosylation;
cAMP, secretion of electrolytes from the intestinal epithelium secretory diarrhea
Cholera enteroToxin
Washer woman’s hands sign
Cholera
Tetracycline or Azithromycin shortens duration
Cholera
V. parahemolyticus / Vulnificus
Minocycline plus Fluoroquinolone or Cefotaxime
Cholera Agar
TCBS
histologic damage to the mucosal surfaces of the jejunum
Campylobacter
Undercooked chicken, unpasteurized milk
Campylobacter
Most common cause of bacterial gastroenteritis
Campylobacter
Guillain Barre
Campylobacter
Reiter’s Syndrome Triad (Reactive Arthritis)
Uveitis
Urethritis
Arthritis
DOA Campylobacter
Erythromycin
Optimum temp for Campylobacter
42 C
Oxidase-positive
Catalase-positive
Urease-positive
H. pylori
Damages the goblet cells of gastric mucosa
H. pylori
most common cause of duodenal ulcers and chronic gastritis
H. pylori
second leading cause of gastric ulcer
H. pylori
Disease Associations:
GASTRIC CARCINOMA
MALT LYMPHOMA
H. pylori
Curved gram-negative rods with a tuft of polar flagella (lophotrichous)
H. pylori
Indole-negative
vs E. coli which is indole-positive
H. pylori
Friedlander’s Pneumonia
Klebsiella
Alcoholic -> Pneumonia
Klebsiella
(currant jelly sputum)
Klebsiella
Second to E. coli as the common cause of sepsis
Klebsiella
DOC Klebsiella
Cephalosporins +/- Aminoglycosides
Facultative gram-negative rods with large polysaccharide capsule
Klebsiella
UTI associated with nephrolithiasis
Proteus
staghorn calculi; composed of magnesium-ammonium-phosphate
Proteus
DOC Proteus
Ampicilin
TMP-SMX
Proteus Agar
BAP
a test that uses antibodies against certain strains of Proteus to diagnose rickettsial disease (as certain rickettsiae share similar antigens
Weil Felix Reaction
(major pathogen for nosocomial infections because of its ubiquitous presence
in the hospital environment
Pseudomonas
chronic pneumonia in cystic fibrosis patients due to biofilm formation
Pseudmonas
inhibits protein synthesis by blocking EF2
Pseudomonas Toxin A
Type III secretion system
Exotoxin A
Hot tub folliculitis
Pseudomonas
Green nail syndrome
Pseudomonas
Skin graft loss due to infection
Pseudomonas
Otitis Externa
Pseudomonas
- Chronic suppurative otitis media
Pseudomonas
Ventilator-associated pneumonia
Pseudomonas
Necrotizing pneumonia (fleur-de-lis pattern)
Pseudomonas
Shanghai fever
Pseudomonas
Peritonitis in peritoneal dialysis patients
Pseudomonas
Antipseudomonal penicilins
Ticarcillin
Piperacillin
Refractory cases of Pseudomonas
Rifampin
Pseudomonas Agar
Cetrimide
sweet, fruity grape-like odor
Pseudomonas
most common pathogen isolated from patients who have been hospitalized longer than 1 week, and it is a frequent cause of nosocomial infections
Pseudomonas
Predominant anaerobe of the human colon
Bacteroides fragilis
Spreads to blood or peritoneum during bowel trauma, perforation, or surgery
Bacteroides fragilis
Armadillos
M. leprae
Phenolase Positive
M. leprae
AIDS Px CD4 <50
MYCOBACTERIUM AVIUM INTRACELLULARE COMPEX (MAI, MAC)
most common cause of crippling of the hand
Leprosy
Nerves Affected in Leprosy
Ulnar, Median
Posterior tibial
Common petrosal
Tender red nodules or humps on both shins
Signals acute flare-ups of disease
Erythema Nodosum Leprosum
Erythema Nodosum Leprosum
Thalidomide
Thalidomide SE:
Phocomelia
Tuberculoid Leprosy DOC
Dapsone + Rifampin
Lepromatous DOC
Dapsone + Rifampin + Clofazimine
tiniest free-living organisms capable of self-replication
Mycoplasma pneumoniae
Requires STEROL for membrane formation
Mycoplasma pneumoniae
Toll-like receptor 2 protein
adheres to epithelial cells of the respiratory tract
causes inhibition of ciliary motion (ciliostasis) and necrosis
P1 Adhesin - Mycoplasma
An exotoxin
Major role in damage to the respiratory epithelium
ADP-ribosylating and vacuolating cytotoxin similar to pertussis toxin.
CARDS
Walking pneumoniae
Mycoplasma
most common infectious cause is M. pneumoniae
Steven Johnsons Disease
DOC mycoplasma
Macrolides
Culture Media of Mycoplasma
Eaton
Dome Shaped Colonies - Fried Egg, Mulberry
Mycoplasma
Chlamydophila psittaci
Azithromycin
TWAR
Chlamydophila pneumoniae
Chlamydophila pneumoniae DOC
Doxycycline
Chlamydia spp
Doxycycline
Chlamydia Trachomatis
A-C
Chlamydia GenitaL
D-K
LGV
Chlamydia L1-L3
Resistant to Lysozyme
Chlamdia
leading infectious cause of blindness
C. trachomatis types A-C
Chronic keratoconjunctivitis
C. trachomatis types A-C
Halberstaedter-Prowazek inclusions)
C. trachomatis types A-C
Most common cause of STDs
C. trachomatis types D-K
Reiter’s Syndrome
Chlamydia, Campylobacter
Neonatal Pneumonia
C. trachomatis types D-K
Papule or vesicular which ulcerates leads to suppurative inguinal lymphadenitis (buboes
LGV
+ Frei test
LGV Chlamydia L1-L3
Chlamydia DOC
Doxycycline
Halberstaedter-Prowazek inclusions
Chlamydia
periplasmic flagella
Leptospira
Leptospira early stage specimen
Blood, CSF
Leptospira late stage specimen
Urine
Immune complex-mediated meningitis and glomerulonephritis
Leptospira
Calf Tenderness, Conjunctival Suffusion
ACUTE LEPTOSPIREMIC PHASE:
- Snowflake lesions on CXR
IMMUNE LEPTOSPIRURIC PHASE:
Glomerulonephritis in Leptospiral inf
IMMUNE LEPTOSPIRURIC PHASE:
Aseptic meningitis
IMMUNE LEPTOSPIRURIC PHASE
most severe form of leptospirosis
Weil’s syndrome
Massive pulmonary hemorrhage
Syphillis
Anthrax
Weil’s
Jarisch-Herxheimer reaction
Syphilis
Leptosirosis
Shepherd’s crook appearance
Leptosira
Darkfield Microscopy
+ Syphillis - Lepto
gold standard / criterion standard for serologic identification of leptospires
LeptoMAT
Leptospira culture media
Ellinghausen-McCullough-Johnson-Harris (EMJH) medium or Fletcher’s medium
White-footed mouse
White-tailed deer
Boreliella burgdorferi
Largest medically important bacterium
Boreliella burgdorferi
Stage 1 Lyme
Erythema chronicum migrans
Stage 2 Lyme
Bells Palsy
AV Block
Stage 3 Lyme
Autoimmune migratory polyarthritis (onion skin lesion)
Boreliela Culture
Barbour-Stoenner-Kelly (BSK)
