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Azhar Gangat (ASUMS) 1
Organism Characteristics
Reservoir/ Transmission (T)/Predisposing Factors (PF)
Virulence Factors (VF)/ Pathogenesis (TX)
ClinicalFindings
Diagnosis
Staphaureus
G+
cocci
β hemolytic
catalase +
coagulase +
salt tolerant
mannitol fermenter
NF: nasal mucosa,skin
T: hands, sneezing, ham/canned meat, custard pastries, potato salad
PF: surgery, break in skin, foreign body (eg. tampons, sutures), neutropenia,IV drug abuse, CGD
1
VF: protein A,surface receptors (eg. teichoic acid), microcapsule, PG layer
2TX:enterotoxin,TSST,exfoliatin,leukocidins (α toxin,P-V leukocidin),enzymes
3
PYOGENIC (abscess):skin infections (+otits externa),sepsis,endocarditis, osteomyelitis,arthritis, post-surgical wound infections, pneumonia,abscess in any organ
TOXIGENIC (superantigen):food poisoning (1-8 hrs), toxic shock syndrome, scalded skin syndrome
4the most common cause of skin infections, food poisoning, osteomyelitis, 2nd for otits externa
blood agar
mannitol-salt agar
Staph epidermidis
G+
cocci
catalase +
coagulase –
novobiocin sensitive
NF:skin,mucous membranes
PF: prosthetic heart valves and joints, intravenous catheters
nosocomial
VF:glycocalyx
endocarditis (within 2 months of surgery, after→ S. viridans)arthritis,osteomyelitis,sepsis in neonates,peritonitis in renal failure
produce β lactamase
Staph saprophytics
G+
cocci
catalase +
coagulase –
novobiocin
community acquired
urinary tract infections (especially in sexually active young women)
2nd to E. coli in causing community acquired UTI
Azhar Gangat (ASUMS) 2
resistant
Strep pyogenes
G+
cocci
catalase –
group A
β hemolytic (clear zone)
bacitracin sensitive
NF:human throat,skin
T:respiratory droplets,direct contact
Antigens:
M Protein(SPAM)Strep. Pyogenes Antibody to M Prtn,
C Carbohydrate,polysaccharide capsule
16
Enzymes:hyaluronidase,streptokinse,DNase
17TX:erythrogenic toxin,pyrogenic toxin A,exotoxin B,streptolysin O,streptolysin S
18
PYOGENIC:phrayngitis,impetigo,Invasivenecrotizing fasciitis,cellulitis,erysipelas,sepsis, puerperal fever
TOXIGENIC:scarlet fever,toxic shock
IMMUNE-MEDIATED (non-suppurative):rheumatic fever,acute glomerulonephritis
19
2nd most common cause of skin infections after S. aureus
Strep agalactiae
G+
cocci
catalase –
group B
β hemolytic(clear zone)
bacitracin resistant
hydrolyze hippurate
Colonization:human vagina
PF:prolonged (>18 hrs) rupture of membranes in women who are colonized with this bacteria,<37 wk gestation, children of mothers lacking antibody to group B strep.,diabetes
T:
neonatal septicemia
meningitis (in 1st month)
24
the most common cause of neonatal sepsis and neonatalmeningitis, E. coli is 2nd
S. pneumonia: adult meningitis
Azhar Gangat (ASUMS) 3
cAMP test + newborns infected during birth
Strep pneumoniae
(pneumococcus)
G+
cocci lacent-shaped diplococci
catalase –
polysac.capsulated
α-hemolytic(green zone, caused by pneumolysin)
optochin sensitive
bile soluble
Colonization:human respiratory tract (no animal)
T:respiratory droplets
PF:CASMIRCirculatory problemsAlcoholismaSplenia Measles infectionInfluenza infectionRespiratory problems
VF:polysac. capsule,lipoteichoic acid,pneumolysin,IgA protease
25
pneumonia(with bloody rusty sputum)jelly-like sputum in Klebsiella,
26otitis media in children,sinusitis in children,meningitis in adults
Strep. pneumoniae is the most common cause of:pneumonia,adult meningitis,otitis media in children,sinusitis in childrenpneumonia in alcoholics
S. agalactiae: nenonatal meningitis
Also:purulent bronchitis,corneal ulcer (purulent discharge in conjunctivitis),pericarditis, sepsis
quelling reaction + (test for swelling of capsule)
blood agar
Strep viridians
S. sanguisS. mutans
G+
catalase –
α-hemolytic(green zone)
optochin resistant
bile insoluble
N F:human oropharynx
PF:damaged heart valves,dental surgery,poor oral hygiene
S. mutans:dental plaque
dextran:leads to dental caries
infective endocarditis (oral route):fever, heart murmur, anemia, embolic events, malaise , fatigue , anorexia, night sweats & weight lossurological instrument route: S. faecalis
after 2 months of surgery, before→ S. epidermitidis
dental caries
blood agar
Enetrococcus faecalis
G+
catalase –
group D
NF:human colon
R:urethra,female genital tract
UTI:dysuria (painful urination),burning urine,↑fear of urination, fever,discharge of ulcer
Azhar Gangat (ASUMS) 4
γ-hemolytic (no hemolysis)
growth in 6.5% NaCl or bile, pH 9, 45˚C
PF:GI or urinary tract surgery,indwelling urinary catheters,urinary tract instruments,
mostly nosocomial
Also:endocarditis (urological instrument route): during medical procedures on GI or U tract: E. faecalis→ blood stream→ previously damaged heart valves→ endocarditisoral route: S. viridans
can cause intra-abdominal and pelvic infection with S.bovis
S. bovis G+
Catalase-
group D
γ-hemolytic (no hemolysis)
no growth in 6.5% NaCl
NF:human colon
PF:carcinoma of colon
endocarditis:especially in patients with colonic carcinoma
Neisseria meningitidis
G -
oxidase +
kidney bean shaped diplococci
capsulated
maltose fermenter
Colonization:human nasopharyngeal area
T:respiratory droplets
VF:polysac. capsule,IgA protease,LPS
32
13 different serotypes (polysac. capsule):eg. A, B, Y, W-135
meningitis,(the most common cause between the ages of 2 & 18)
meningococcemia (Waterhouse-Friderichsen syndrome)
33
chocolate agar(37˚C, 5% CO₂)
Neisseria gonorrheae
(gonococcus)
G –
oxidase +
coffee/kidney bean shaped diplococci
R:human genital tract(sensitive to dehydration and cool conditions)
T:sexual contact,Infection of
VF:pili,LOS,IgA
Other VF’s:OPAPORRMP
gonorrhea:
Male:urethritis,proctitis,epididymitis
Female:cervicitis,
Thayer-Martin medium (chocolate agar containing antibiotics)
Azhar Gangat (ASUMS) 5
pili
glucose fermenter
newborns during birth
-dissemination also possible → septic arthritis
FBPLIP
salpingitis,PID→ sterility & ectopic pregnancy
37
Newborn:(2-5 days onset)purulent conjunctivitis (opthalmia neonatorum),→ blindness
Dissemination:the most common cause of septic arthritis in sexually active adults
Moraxella catarrhalis
G –
diplococci
close relative of Neisseria
NF:upper respiratory tract
otitis media,bronchitis,bronchopneumonia (elderly with COPD-chronic obstructive pulmonary disease)
Bacillus anthracis
G +
square-ended rod
spore formation
aerobe
capsulated
nonmotile
R:spores in:soil,animal skin,animal products (eg. wool, hair),contaminated meat
T:skin,mucous membrane,respiratory tract
VF:capsule(D-glutamase, not polysac.)
TX:exotixins:edema factor,lethal factor,protective antigen
47
anthrax:cutaneous (95%),pulmonary (4%),GI (1%)
48
not communicable person-to-person (ie. through respiratory droplets)
blood agar,
mediastinal widening in x-ray
Bacillus cereus
G +
rod
spore formation
aerobic
motile
R:rice,other grains
PF:Reheated fried rice (Chinese restaurants),Held warm (not hot) for long periods
TX:enterotoxins:emetic type,diarrheal type
emetic (1-6 hrs) -fried rice -S. aureus type -vomiting -abdominal pain
diarrheal (18 hrs) -meats, sauces -E. coli/ Clostridial type -watery diarrhea
Azhar Gangat (ASUMS) 6
Affect:GI tract
may cause:eye infections
2nd most common cause of food poisoning after S. aureus
Clostridium tetani
G +
rod(tennis racket/drum stick shaped)
spore formation
anaerobic
R:soil
PF:wound,skin breakage,skin-popping,infected mother may infect the newborn
poor blood supply in the necrotic tissue helps its growth
TX:Tetanospasmin (exotoxin): -blocks inhibitory mediators (eg. glycine, GABA, glutamic acid)
tetanus: -spastic paralysis -locked jaw (trismus) -violent muscle spasms -grimace(risus sardonicus) -increased reflexes -respiratory failure →death
neonatal tetanus: -enter through contaminated umbilicus or circumcision wound
difficult to culture
Clostridium botulinum
G +
rod
spore formation
anaerobic
R:soil,dust
T:canned/vacuum packed food without sterilization,green beans,peppers,mushrooms,smoked fish,drug abuse skin-popping ,honey for infants
TX:-preformed in can-labile (ie. inactivated by heating)
-blocks release of Ach
Adult (2-3 hours):wound botulism: -toxins produced at the side of the wound-weakness, dizziness, blurry vision, flaccid paralysis
Infant (2-3 days):Infant botulism (honey):-toxins produced in the gut-diplopia,-dysphagia,-respiratory muscle failure,-flaccid paralysis
not cultured,mouse protection tests
Clostridium perfringes
G +
rod
spore formation
anaerobic
R:soil
NF:colon, vagina
T:war wounds, automobile/motor
TX:lecithinase(α-toxin):-gas production-cell membrane damage→ hemolysis
wound infections:-pain,-edema, -cellulitis,-crepitation (gas presence)
also:hemolysis, jaundice, blood-tinged exudates
blood agar: double zone of hemolysis
egg-yolk agar: lecithinase presence
Azhar Gangat (ASUMS) 7
accidents,septic abortions,
food contamination
PF:reheated food, especially meat dishes
→shock & death
Food Poisoning (8-16 hours):watery (non-inflammatory) diarrhea, little vomiting
3rd most common cause of food poisoning after S. aureus and B. cereus
Clostridium difficile
G +
rod
spore formation
anaerobic
R:human colon
T:fecal-oral route
PF:antibiotics,chemotherapy
especially nosocomial
TX:exotoxin Aexotoxin B
(add glucose to G protein involved in actin filament polymerization→ depolymerization of actin→ death of enterocyte)
pseudomembranous colitis(presence of yellow-white plaques on colonic mucosa),
bloody/nonbloody diarrhea(the most common nosocomial cause of diarrhea)
ELISA tests
Listeria monocytogenes
G +
rod
arranged in V or L shapes
tumbling motility
facultative intracellular parasite
cold growth
loves lysosomes
β hemolytic(narrow clear zone)
R:animals,plants,soil
T:unpasteurized milk,contaminated vegetables,animal contact
Cold Growth:cheese, cabbage
PF:placenta/delivery,renal transplant,↓ cell mediated immunity
TX:listerolysin O: -similar to streptolysin O -degrades cell membranes
actin rockets:cell to cell movement
sepsis (granulomatosis infantiseptica),
acute meningitis (after 1-4 weeks),
gastroenteritis: -watery diarrhea, fever, headache, abdominal pain, little vomiting -caused by contaminated dairy products & undercooked meats
sepsis & meningitis in immunosuppressed,abortion,premature delivery
the most common cause of sepsis and meningitis in renal transplant patients and adults with cancer
blood agar
Corynebacteria diphtheriae
G +
rod (beaded
R:human upper respiratory tract
TX:diphtheria toxin:-inhibits protein
diphtheria: -inflammation of throat -thick, grey
volutin granules stain
Azhar Gangat (ASUMS) 8
appearance)
aerobic
non-motile
V or L shapes
T:air-borne droplets
PF:skin lesion,poor skin hygiene
synthesis by ADP-ribosylation of EF-2 (elongation factor)this toxin is also present in Pseudomonas
pseudomembrane (bull neck) -can lead to: -tracheal/ tracheal extension→ airway obstruction -myocarditis→ arrhythmia -recurrent laryngeal nerve palsy
metachromat-ically
blood agar
potassium tellurite agar
Actinomyces israelii
G +
rod (long branching filaments)
anaerobe
sulfur granules (hard, yellow coloured)
NF:gingival crevices(oral cavity),female genital tract
PF:upper body lesions/trauma (especially face & neck),intrauterine device retention for a long period of time
non-communicable
hard, non-tender swelling drains pus through sinus tracts
actinomycosis:
cervicofaical (lumpy jaw): -dental trauma, poor oral hygiene
pelvic form: -intrauterine contraceptive device (IUCD)
thoracic: -aspiration (removal) with contagious spread
abdominal: -surgery or bowel trauma
Nocardia asteroides
G +
rod (thin branching filaments)
aerobic
weakly acid-fast
R:soil,dust
T:airborne,trauma
non-communicable
nocaridiosis (pulmonary infections):
bronchopulmonary: -cough -fever -dyspnea -begins as pulmonary infection and may spread as abscess/ sinus tracts -immunocompromized: may spread to brain, skin, kidneys
cutaneous/subcutaneous: -cellulitis -granuloma -ulcer -swelling -starts with trauma
Mycobacterium tuberculosis
acid-fast(mycolic acids)
R:human lungs
-no toxin production
TB: -any part of the body could be affected except teeth
Lowenstein- Jensen medium
Azhar Gangat (ASUMS) 9
rod
aerobic
facultative intracellular
typical mycobacteria
slow growth
UV sensitive
pathogenic for guinea pigs
T:respiratory droplets
VF:lipid content,phosphatides,cord factor,sulfatides,PPD
73PF:poverty,HIV infection,IV drug abuse
-causes infection of macrophages and other RE-cells
-exported repetitive protein→ prevents fusion of phagosome and lysosome
-transmission through lymphatics→ lymphadenopathy (matty palpation)
low grade fever (no chill),night sweat,weight loss,cough with hemoptysis,other signs depending on the organ involved (ie. pneumonia-like symptoms if the lungs are involved) also:scrofula
Auramin-Rhodamine stain
tuberculin test
Mycobacterium kansasii
Mycobacterium marinum
atypical mycobacteria
non-pathogenic guinea pigs
photochromogens (yellow-orange pigments when exposed to light)
T:soil,water
T:water (fresh/salt), swimming pool, aquarium,
PF:scuba divers,skin abrasion
lung disease
swimming-pool granuloma (fish-tank granuloma): -granulomatous, ulcerating lesion in the skin
Mycobacterium scrofulaceum
atypical mycobacteria
non-pathogenic guinea pigs
scototochromogens (pigments in dark)
T:Oropharynx
infection of draining lymph nodes
scrofula: -granulomatous cervical lymphadenitis -usually in children
Azhar Gangat (ASUMS) 10
Mycobacteriumavium
Mycobacteriumintracellulare
MAI
atypical mycobacteria
non-pathogenic guinea pigs
nonchromogens (no pigments)
T:soil,water
PF:AIDS,cancer,immuno-compromized
chronic pulmonary diseases
MAI:the most common bacterial infection in AIDS patients
Mycobacteriumfortuitum
Mycobacteriumchelonei
atypical mycobacteria
non-pathogenic guinea pigs
rapid growth
T:soil,water
PF:immune- compromised,prosthetic heart valves and joints
rarely occurring infection:skin, soft tissue infections
Mycobacteriumleprae
acid-fast
rod
obligate intracellular
slow growth
optimal growth at cool temperature (30˚C)
R:human mucosal membrane,skin,superficial nerves
T:nasal discharge from untreated leprosy patients
leprosy:
tuberculoid:-fewer lesions-macular (flat)-nerve enlargement (claw hand)
lepromatous:-numerous lesions-nodular-loss of eyebrows-destruction of nasal sputum-paraesthesia (abnormal sensation)-leonine facies (ridges & furrows)
+ lepromine test
- lepromine test
Pseudomonasaeruginosa
G –
rod
aerobic
oxidase +
nonfermente
R:water
T:water aerosols,raw vegetables,flowers
PF:
LPS:exotoxin A: -tissue necrosis (especially liver) -inhibits protein synthesis by ADP-ribosylation of EF-2 (elongation factor)
in normal people:loose stool,folliculitis,eye ulcers
burnt patients:skin infections,ecthyma gangrenosum (black necrotic centre,
MacConkey’s/ EMB agar
Azhar Gangat (ASUMS) 11
r
pyocyanin -blue colour in pus
pyoverdin (fluorescein) -yellow-green colour
odour:grape-like/corn nacho
nosocomial,extensive burns,chronic respiratory disease (cystic fibrosis),catheterized,immunosuppresed,anesthesia injections/CSF sampling, swimmers,gym goers,contact lenses
-this toxin is also present in C. diphtheria
pyocyanin:-damages cilia and mucosal cells of respiratory tract
elastase, protease: -help in invasion -histotoxic
erythematous-red-margin),eschar,cellulitis (blue-green pus),septicemia (also in AIDS pt’s)
in catheterized patients:UTI
in cystic fibrosis patients:recurrent pneumonias,septicemia
after CSF sampling/ anesthesia injection: meningitis
swimmers:otitis externa (most common casue),neck down (hot tub) follicles
gym shoes:osteochondritis
contact lens users:corneal infections
sepsis caused by P. aeruginosa has >50% mortality rate
Campylobacterjejuni
G –
rod (curved: comma/S shaped)
polar flagella
microaero-cephalic
grows well at 40˚C
motile
oxidase +
R:cattle, sheep, cat, dog,intestinal tract of humans
T:fecal-oral route
PF:improperly cooked chicken,raw eggs,poultry products,meat,milk
TX:enterotoxin: -destruction of mucosal surfaces of colon → blood and pus in stool
inflammatory diarrhea: >10 stools/day -bloody -abdominal pain -malaise -fever-lasts 3-5 days
most common cause of inflammatory diarrhea,2nd most common is salmonella
predisposes to Guillain-Barré syndrome: -autoimmune disease -demyelination
blood agar
Azhar Gangat (ASUMS) 12
urease -Helicobacterpylori
G –
rod (curved)
polar flagella
microaero-cephalic
grows well at 37˚C
oxidase +
urease +
R:human stomach
T:fecal-oral route,oral-oral (communicable),clustered families
attachment to mucosa→ urease → ammonia formation + inflammation →damage to mucosa ↓this damage predisposes to peptic ulcer and gastritis
ammonia helps bacterium survive by neutralizing acid
ammonia breath
gastritis,peptic ulcers,severe upper abdominal pain
helicobacter infection: predisposing factor for gastric cancer
blood agar
Legionellapneumophila
G – (weakly)
rod (pleomorphic)
R:water: -air conditioners -water coolers -rivers -streams
PF:Renal transplantAlcoholicCancerOld ageSmokerAIDS
T:aerosol from contaminated A/C
non-communicable
LPS Legionnaire’s disease(atypical pneumonia) with: -confusion -non-bloody diarrhea -proteinuria -hematuria -cough -resolves in 7-10 days
hyponatremia (↓Na)
Pontiac fever: -flu (fever, soar throat) -no pneumonia
charcoal-yeast agar
iron & cystein required
Bordetella pertussis
G –
rod
encapsulated
R:humans -10 years after vaccination, humans serve as reservoirs
hemagglutinin (FHA)
TX:pertussin(adenylate
pertussis (whooping cough):
catarrhal stage (1-2 weeks)
paroxysmal stage (2-4 weeks)
Bordet-Gengou medium
Azhar Gangat (ASUMS) 13
T:respiratory droplets
cyclase),
tracheal cytotoxin
98
E. coli: ADP ribosylation is by Gs protein
Gi protein in B. pertussis
convalescence (>3 weeks)
Francisella tularensis
G –
rod (pleomorphic)
facultative intracellular
R:wild animals:rabbits,deer,rodents
T:tick bite,aerosols (rabbit-skinning),ingestion (contaminated water, infected meat)
non-communicable
tularemia (endemic in the US):
tick bite:ulceroglandular type: -fever -ulcer at bite site -regional lymph node enlargement
skinning rabbits:pneumonia
ingestion:typhoidal tularemia
Brucella
melitensis(goats)
abortus(cattle)
suis(pig)
G –
rod
zoonotic
R:goats,sheep,cattle,pigs
T:unpasteurized dairy products (goat milk),direct contact to animals,slaughterhouse workers
localization in reiculoendothelial system -lymph nodes -liver -spleen -bone marrow
brucellosis (undulant fever): acute (cepticemia):
chronic (in older people):
102
Escherichia coli
G –
rod (motile)
NF:colon,vagina,urethra
TX:K polysaccharide (capsule),O antigen (cell
UTI:the most common cause of UTI is E. coli, S. saprophyticus is 2nd
blood agar
EMB (green)
Azhar Gangat (ASUMS) 14
facultative anaerobe
lactose fermenter
glucose fermenter
oxidase –
nitrates to nitrites reduction
PF (UTI):strinctures, stones, abnormal urine flow,indwelling urinary catheters
PF (watery diarrhea):poor sanitization of water,fruits/ vegetables contaminated with human feces
PF (bloody diarrhea):undercooked hamburgers,raw milk,fallen apples (apple juice)
wall) -serologic typing,H antigen (flagella)
TX:heat labile toxin,heat stable toxinE. coli: ADP ribosylation is by Gs protein,Gi protein in B. pertussis
verotoxin:
104
neonatal sepsis & meningitis:2nd most common cause after S. agalactiae
Enterotoxigenic (ETEC): -traveler’s diarrhea (watery) -diarrhea in <3 years old
Enteropathogenic (EPEC): -2nd most common cause of infantile diarrhea after rotavirus
Enteroinvasive (EIEC): -actin (Jet trails) -bloody/ watery diarrhea
Enterohemorrhagic (EHEC): -bloody diarrhea -hemolytic uremic syndrome -hemorrhagic colitis -no fever (present in shigellosis)
Enteroaggressive (EaggEC): -persistent diarrhea -vomiting
105
MacConkey’s agar (pink)
Shigella
disenteriae(severe)
sonnei(common)
G –
rod
facultative anaerobe
glucose fermenter
oxidase –
nitrates to nitrites reduction
R:human colon(no animals)
T:fecal-oral route
fingersfoodfecesflies
communicable-low quantity needed to cause an infection
TX:O antigen (cell wall) -serologic typing
invasion of the cells of distal ileum and colon
dysentery: -fever (>101˚F) -lower abdominal pain -tenesmus (spasms of urogenital region) -first watery, then bloody diarrhea -shallow ulcers
shigellosis:-the most severe form of diarrhea (10-15 episodes/day)
blood agar
EMB/ MacConkey’s agar -colourless colonies
Klebsiella G – R: TX: pneumonia: blood agar
Azhar Gangat (ASUMS) 15
rod
large capsule
facultative anaerobe
lactose fermenter
glucose fermenter
oxidase –
nitrates to nitrites reduction
human colon,upper respiratory tract
T:from own flora in low immunity,respiratory droplets,catheters (nosocomial)
PF:diabetes,alcoholism,old age,chronic respiratory disease
K polysaccharide (capsule) -antiphagocytic
O antigen (cell wall) -serologic typing
LPS: -fever -inflammation -shock
-abscess -thick, bloody, jelly-like sputum
UTI: -nosocomial (catheters)
septicemia: -in immunocompromized
EMB/ MacConkey’s agar -pink colonies
Salmonella
typhi
enteritidistyphimuriumcholeraesuis
G –
rod (motile)
facultative anaerobe
produce H2S
glucose fermenter
oxidase –
nitrates to nitrites reduction
R:humans (no animals)
T:fecal-oral route from human carriers (gall bladder)
PF:↓ stomach acid
R:enteric tracts of humans, chickens, turtles
T:raw chicken, egg
PF:sickle cell anemia
PF:
TX:K polysaccharide (capsule)
O antigen (cell wall) -serologic typing
H antigen (flagella)
Vi antigen (typoid)
-invasion of epithelium of SI & LI(enteric fever)
typhoid fever/ enteric fever ( S . typhi/ S. paratyphi): -rose spots -constipation -gallbladder inflammation -Vi antigen:multiplication in Payer’s patches→ spread to phagocytes of liver, gall bladder, & spleen → leading to bacteremia-constipation followed by diarrhea
enterocolitis /gastroenteritis(6-8 hours): -inflammation -loose bloody stool -2nd most common cause of inflammatory diarrhea, after Campylobacter
septicemia: -in very young/ elderly
blood agar
EMB/ MacConkey’s agar -colourless colonies
widal test
Azhar Gangat (ASUMS) 16
sickle cell anemia
PF:aortic aneurysms, infarcts
osteomyelitis/ arthritis: -followed by pneumonia, meningitis -the most common cause of osteomyelitis in patients with sickle cell disease
metastatic abscess: -abscess away from primary origin
Aerobes: Negging Pests Must Breath
Nocardia
Pseudomonas aeruginosa
Mycobacterium TB
Bacillus
Anaerobes: A - B – C
Actinomyces
Bacteroides
Clostridium
Capsulated: Some Bacteria Have An Effective Paste Surrounding Membrane Yielding Pseudo Fort, Bypassing Killing
Strep. pneumonia
Bordetella, Bacteroides
H. influenza
Anthracis (Bacillus)
E. coli
Azhar Gangat (ASUMS) 17
Pasteurella
Salmonella
Meningitidis (Neisseria)
Yersinia
Pseudomonas
Francisella
Brucella
Klebsiella
Pneumonia (most common causes):
Type OrganismMost common (bloody-rusty sputum) S. pneumonia Thick, bloody, jelly-like sputum KlebsiellaIn alcoholics S. pneumoniaIn cystic fibrosis patients (recurrent) Pseudomonas aeruginosaAtypical pneumonia (Legionnaire’s disease) Legionella pneumophiliaAfter rabbit-skinning Francisella tularensisSequel to osteomyelitis non-typhoid SalmonellaPyogenic infection S. aureus
Meningitis (most common causes):
Type OrganismNeonatal S. agalactiae
E. coliAdult S. pneumoniaeBetween ages 2 & 18 Neisseria meningitidisIn renal transplant & cancer patients Listeria monocytogenesAfter CSF sampling/ anesthesia injection Pseudomonas aeruginosaSequel to osteomyelitis non-typhoid Salmonella
Gastroenteritis:
Transmission Vomiting Diarrhea OrganismMost Common:custard pastries, potato salad
more than diarrhea
watery S. aureus
Azhar Gangat (ASUMS) 18
after 1-8 hours2nd Most Common:reheated fried rice/ Chinese restaurant
after 1-6 hours wateryafter 18 hours
B. cereus
Most Common Nosocomial bloody/ non-bloody Clostridium difficileUnpasteurized, contaminated dairy products, undercooked meats
little watery Listeria monocytogenes
Most Common Inflammatory:cattle, sheep, dogsorimproperly cooked chicken, raw eggs, poultry products, meat, milk
bloody Campylobacter jejuni
2nd Most Common Inflammatory:from humansorraw chicken, egg
bloodyafter 6-8 hours
Salmonella
A/C, water cooler contaminationwith atypical pneumonia
non-bloody Legionella pneumophila
Traveler’s Diarrhea:poor sanitization of water, contaminated fruits & vegetables
watery E. coli (Enterotoxigenic)
2nd Most Common cause of Infantile diarrhea after rotavirus
watery E. coli (Enteropathogenic)
watery/ bloody E. coli (Enteroinvasive)
Undercooked hamburgers/ fallen apples (juice)
bloody E. coli (Enterohemorrhagic)
vomiting persistent E. coli (Enteroaggressive)
Most Severe Formwith fever & tenesmus (dysentery)
first watery, then bloody
Shigella