Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Microbio Block 1 > Enterobacteriaceae, Klebsiella, Pseudomonas > Flashcards

Enterobacteriaceae, Klebsiella, Pseudomonas Flashcards

(67 cards)

Start Studying
1
Q

Where are enterobacteriaceae?

A

Widely distributed Gram neg bacilli: in soil, water, plants, GI of humans and animals
Majority of urinary isolates; large portion of blood, peritoneum, and resp cavity isolates

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Morphology of enterobacter

A

Average size, non-spore-forming G- bacilli that may have motility (flagella) or not (Kleb, Shig, Yersinia)
Aerobic or facultative anaerobes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Enterobacter and Quellung reaction

A

Some positive (Kleb, Enterobacter, E. coli), some negative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Species with positive Quellung

A 
Encapsulated: SHiNSKSS
Strep pneumo
H. influenza
N. meningitidis
Salmonella
Klebsiella
group B Strep
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

GNR infections

A

Enteritis (E. coli, Salmon, Shig, Yers)
Non-enteric: UTI, cellulitis, soft-tissue abscess, intra-abd abscess, bacteremia, liver/spleen abscess, foreign body infxn, pneumonia, endocarditis
*External or from gut spillage/ transmigration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Morphology & diseases of Escherichia

A

G-, fac anaerobe; oxidase neg, lactose fermenter
Commonest bact in gut, commonest cause of UTI
Most infections E. coli; most endogenous, enteritis exogenous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

E. coli virulence factors

A

Fimbrial adhesins, secretion systems to export proteins for pathogenesis and toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

E. coli causes of enteritis

A

ETEC (enterotoxigenic), EHEC (enterohemorrhagic), EIEC, EPEC, EAggEC
*Uropathogenic E. coli (most likely to be encapsulated, produce P fimbriae, produce cytolytic hemolysin, multiple Fe-acquiring mechanisms)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

ETEC diseases, spread, tx

A

Leading cause bact diarrhea in developing world (Traveler’s diarrhea)
9% diarrheal deaths, 1% deaths in kids 1-2 days = sec diarrhea, n/v
Tx: rehydrate +/- abx (pregnant, immunocompromised)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Pathogenesis of ETEC

A

Ingestion of contaminated food, water -> attach to small intestinal epithelial cells but don’t invade -> secrete heat labile and heat stable toxins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Heat labile and heat stable toxin mechanisms

A

Labile: similar to cholera toxin, A-B toxin -> ADP ribosylation of Gs -> activate AC -> inc cAMP
Stable: stimulates GC -> inc cGMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

EHEC alternative name

A

Shiga toxin producing E. coli (STEC)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

EHEC epidemiology

A

Undercooked meats, contaminated drinking water, foods; few organisms needed for infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

E. coli O157:H7 virulence & mechanism

A

EHEC with O and H antigens, Shiga like toxins Stx-1,2 encoded by phage
A subunit internalized, stops protein synthesis; B subunit binds GB3 glycolipid-R in colon, kidney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

E. coli O157:H7 diseases

A

Common cause diarrhea/ dysentery in dev’d world

Severe abd pain, bloody diarrhea, hemorrhagic colitis, HUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

HUS

A

After 2-7% E. coli O157:H7 infections; mostly kids, 5-10% mortality
Thrombotic microangiopathy; acute renal failure, anemia, thrombocytopenia; can lead to HTN, renal impairment
*NO ABX - can worsen it; supportive care

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Characteristics of enteritis caused by EIEC, EPEC, EAggEC

A

EIEC: Shigella-like dysentery w blood, mucus
EPEC: Pediatric diarrhea, esp infants; watery or bloody diarrhea in infants, person-person spread
EAgg: childhood diarrhea, more than 14 days; watery w mucus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Non-enteritis E. coli infections

A

UTI (CA or nosocomial), blood stream infections, pneumonias (neonatal, nosocomial), meningitis (after surgery, VP shunts), peritonitis (peritoneal dialysis)
Tx based on abx-susceptibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Salmonella enterica serotypes and transmission

A

S. typhi and paratyphi are serovars - adapted to humans
2500+ serotypes based on H and O Ags
Fecal-oral spread, person-person

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Epidemiology: non-typhi Salmonella

A

Contaminated foods, fecal-oral spread at day care or food service personnel; animal reservoirs: poultry, reptiles (TUTTLES), livestock, birds, domestic animals, rodents

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Clinical syndromes of Salmonella

A

Enteritis (6-48 hr for 3-7d, n/v, diarrhea, cramps, +/- fever, constipation first, no blood or pus in stool, stools pos ww-yy post illness)
Septicemia, osteomyelitis, aortitis
*Especially in immunosuppressed (HIV+, malignancy, certain drugs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Virulence of Salmonella

A

Endotoxin, invasion genes (chromosomal, attachment and invasion)
Entry into host: ingest contam food/water, fecal-oral spread, moderate number of bacteria
*Susceptible to low pH, antacids increase susceptibility to dz

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is Salmonella infection established?

A

Attach to epi cells, uptake, replication in endosome, penetrate into subepi tissue, inflam response contained -> spreads to blood = sepsis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Treating, preventing, controlling Salmonella

A

Sx: fluid replacement
Abx not for uncomplicated GI -> may prolong carrier state; abx for septicemia
Prev/control: sanitation, water and sewage treatment, proper food prep and storage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
S. typhi epidemiology
Contaminated food or water; humans are only reservoir, but passive carriage by flies from feces to food Chronic carriers: GB colonization, endemic reservoirs
26
Symptoms of S. typhi
Enteric fever; incubate 7-21 d, starts as diarrhea, bacteremia -> fever (3-4 w), malaise, anorexia, myalgia, HA, rose spots, relative bradycardia, hepatosplenomegaly, lymphocytosis Complications: infxn of bone, heart valves, brain, Peyer's patches bleeding (longitudinal ulcer)
27
Virulence factors & mechanisms of disease of S. typhi
Vi PS capsule, endotoxin Invade M cells in PPatches, replicate and transport to subepi tissue, survive in MFs, enter blood and lymph -> replicate in liver, spleen with prolonged release of endotoxin -> GB colonization, shed in bile
28
Treating, preventing, controlling S. typhi
Tx: abx if complicated and susceptible | Sanitation, carriers shouldn't handle food, vaccines against Vi capsular PS (oral or IM)
29
Epidemiology of Shigella
Fecal-oral spread, primarily dz of kids Contaminated food or water FEW organisms for infection (vs. Salmonella)
30
Clinical symptoms of Shigella
Watery diarrhea -> in 1-3 days: abd cramps, fever, blood/ pus in stools, tenesmus *Identical to EIEC Can cause HUS (toxin)
31
Morphology of Shigella
G- bacillus, non-motile, species classified by O Ag, n H Ag | Not a lactose fermenter, relatively biochemically inactive
32
Virulence factors of Shigella
Shigatoxin (some spp), virulence plasmid (attachment, invasion, intracellular replication)
33
Tx, prevention, control of Shigella
Tx: fluid replacement, abx to shorten duration and fecal excretion (cipro, TMP) Prevent: wash hands, chlorinate water, sanitation
34
Yersinia reservoirs
Y. enterocolitica: pigs, rodents, livestock | Y. pestis: rodents
35
Y. entercolitica physiology, structure, epidemiology
G- bacillus, motile, flagella at low temp (22*), growth at 4* C (inc metabolic activity at low temp) Fecal-oral spread; milk, food, water Common in Scandinavia, cold areas of N. America
36
Clinical syndromes of Y. entercolitica
Diarrhea, fever, abd pain ("appendicitis"); similar to Salmonella, mesenteric lymphadenitis Complications: septicemia, hepatic abscesses Post-infxn: reactive arthritis (HLA B27)
37
Pathogenesis and tx for Y. entercolitica
Invasive; heat-stable enterotoxin similar to E. coli ST | Tx: supportive care for non-complicated cases; FQs, ceph, tetras, etc. based on sensitivity
38
Y. pestis epidemiology
Rat fleas from rat to human; common in Africa, Asia, SW USA 1000-2000 cases in world per year Used as biological weapon
39
Morphology of Y. pestis
Non-motile, non-spore forming, not lactose fermenter Bipolar staining with Giemsa or Wright stain Aerobic on most media, optimal at 28*
40
Clinical symptoms of Y. pestis
Bubonic plague: fevers, chills, HA, firm buboes (groin) w edema; 50% fatal wo tx Pneumonic plague: 1' or 2', pneumonia w watery or purulent sputum w bacteria; 50% mortality (100% wo tx) Septicemic plague: bacteremia, no buboes, fever, sepsis, 33% fatal (100% wo tx)
41
Tx of Y. pestis
Streptomycin, gentamicin, tetracyclines, chloramphenicol | *Many side effects
42
Klebsiella pneumoniae infections
Aspiration pneumonia Abscesses in lung, liver especially in Alcoholics, diabetics Can get MD-ResistAnce
43
Klebsiella virulence & symptoms
PS capsule -> mucoid colonies Currant jelly sputum in pneumonia (esp alcoholics) MDR strains: ESBL, KPC
44
Proteus morphology & clinical syndromes
P. mirabilis most common pathogen G- bacillus, very motile Causes UTIs, kidney stones (alkaline urine bc urease pos -> precipitation of Mg and Ca)
45
Urease positive organisms
``` PUNCHK Proteus Ureoplasma Nocardia Cryptococcus Helicobacter Klebsiella ```
46
Enterobacter morphology & clinical syndromes
G-, lactose fermenter, fac anaerobe Pathogens: E. cloacae, aerogenes UTI, pneumonia, blood stream infxn, nosocomial infxn, etc.
47
Treatment of enterobacter & resistance mechanism
"Inducible AmpC" -> tx failure w use of routine abx | Consider FQs, carbapenems
48
Serratia morphology and clinical syndromes
G- enterobacteriaceae | Any infection, commonly nosocomial infections
49
Resistance mechanism of Serratia
Inducible AmpC -> tx failure w use of routine abx
50
Pseudomonas aeruginosa morphology
Aerobic, G- bacilli (single or pairs), oxidase+, non-lactose fermenter, motile with monotrichous polar flagellum, multiple cell surface pili/fimbriae Can use wide range of carbon/energy sources
51
Pigmentation and hemolysis of P. aeruginosa
Blue-green phenazine (pyocyanin), red (pyorubin), or black (pyomelanin) Colonies have metallic sheen, sometimes slimy B-hemolysis Grape-like odor
52
What is alginate?
"Mucoid exopolysaccharide", leading to mucoid appearance of strains from CF patients and occasionally other patients w chronic P. aeruginosa infxns Most strains of P. aeruginosa can produce it
53
Pseudomonas virulence factors
Adhesins, alginate, exotoxin A, exoenzyme S, elastolytic activit, phospholipase C, pyocyanin, abx resistance
54
What are exotoxin A, exoenzyme S, and pyocyanin of Pseudomonas?
A: inhibits protein synthesis, causes tissue damage (eye infxn, burn) S: inhibits protein synthesis, interferes with phagocytosis Pyo: makes ROS -> tissue damage
55
Where is Pseudomonas found?
Ubiquitous in water, soil, plants; can colonize anywhere in body and cause any infection
56
Pseudomonas infections
Wound infxn, hot tub dermatitis; chronic or malignant otitis externa; burn wound infxn, endocarditis (IVDU); bacteremia, sepsis, ecthyma gangrenosum; nosocomial, UTI, pneumonia, meningitis PSEUDO: Pneumonia, Sepsis, External otitis, UTI, Drug use/Diabetic, Osteomyelitis
57
Transmission of Pseudomonas & at risk populations
Moist reservoirs Can be normal GI flora in hospitalized pts Contact and endogenous spread Immunocompromised, drug users, burn patients
58
Pseudomonas tx and prevention
Resistant to: FQ, B-lactam, AGs; easily MDR Endocarditis: double coverage Good aseptic technique, avoid unnecessary use of broad-spectrum abx, remove indwelling lines asap Isolate pts with MDR strain
59
Campylobacter epidemiology
Most common cause bacterial gastroenteritis Transmitted by chickens, cattle, swine, cat/dog Contaminated meat, fish, milk, mushrooms, raw seafood Contaminated water (animal feces)
60
Campylobacter jejuni morphology
G- bacillus, very small, comma- or S-shaped Motile: single polar flagella or darting corkscrew Growth: reduced O2, increased CO2, elevated temp
61
Clinical syndromes Campylobacter
Gastroenteritis (1-7d post): watery diarrhea or dysentery (fever, and pain, bloody stool) for 1-2 w Septicemia rarely
62
Autoimmune responses to Campylobacter
? IBS; reactive arthritis; Guillain-Barre syndrome (may cause 20-40% GB cases; 2-3 post febrile illness) d/t Ab to core sugars of LPS cross-rx w gangliosides
63
Tx and prevention Campylobacter
Self-limiting; fluid- and electrolyte replacement; multiple abx-res plasmids Erythromycin (enteritis) or AGs (septicemia) Prevention: proper food prep, good sanitation, pasteurize milk
64
H. pylori morphology
G- spiral-shaped bacillus w corkscrew motility
65
Epidemiology and clinical syndromes H. pylori
In 70-100% pts with gastritis, gastric ulcer, duodenal ulcer Infxn increases with age ? also gastric adenocarcinoma?
66
Virulence and transmission of H. pylori
Urease, motility, mucinase, adherence factors, endotoxin, cytotoxin No animal reservoir, likely fecal-oral spread
67
Dx and tx of H. pylori
Gastric biopsy or culture; serology or urea breath test (monitor tx this way) Tx: combo abx (amox, tetra, metro); PPI, bismuth (anti-inflam)

Microbio Block 1 (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions