Bacteriology Flashcards
Catalase positive
Staphylococcus
Catalase negative
Streptococcus & others
Coagulase positive
S. aureus
Coagulase negative
CNSS
Grouping method for Streptococci
Lancefield grouping
Group A Strep.
Strep. pyogenes
Group B Strep.
Strep. agalactiae
Group D Strep.
Enterococci, Strep. bovis, Strep. suis
Which haemolytic pattern do group A & B streptococci demonstrate?
beta hemolytic
Which haemolytic pattern does Viridans Streptococci demonstrate?
alpha hemolytic
Which haemolytic pattern does Streptococcus pneumoniae demonstrate?
alpha hemolytic
Which haemolytic pattern does S. aureus demonstrate?
beta hemolytic
Incubation period for S. aureus gastroenteritis
1~6 hours
Abx for MSSA
Cloxacillin
Abx for MRSA
IV vancomycin
Abx for Staphylococcus saprophyticus
Penicillin
Major symptoms of rheumatic fever in Jones criteria (6)
fever, pancarditis, migratory polyarthritis, chorea, subcutaneous nodules, erythema marginatum
Which disease causes erythema marginatum?
Rheumatic fever
Post-streptococcal diseases (2)
Rheumatic fever, post-streptococcal glomerulonephritis
Which antibiotics do Enterococcus spp. resistant to? (2)
cephalosporins, vancomycin (emerging)
Which Streptocci transmits disease by zoonosis and is thus notifiable?
Streptococcus suis
Streptococcus that shows diplococci under microscope (2)
Streptococcus pneumoniae, Enterococcus
Transmission of Bacillus anthracis
cutaneous, pulmonary, GI
Pathogen for woolsorter’s disease
Bacillus anthracis
Pathogen once as bioterrorism agent, being spores in envelope
Bacillus anthracis
Pathogen secreting 2 forms of enterotoxins (pathogen + 2 enterotoxins)
Bacillus cereus. Emetic form & diarrheal form
Pathogen for fried rice syndrome
Bacillus cereus
Spore-forming gram positive bacilli (2 genus)
Bacillus spp., Clostridium spp.
Non-spore-forming gram positive bacilli (3)
Corynebacterium diphtheriae, Listeria monocytogenes, Actinomyces spp.
Bacteria that produces acid in vagina to inhibit other pathogens
Lactobacillus
Bacteria as probiotics to treat paediatric diarrhoea
Lactobacillus
Properties MacConkey plate is differentiating and the corresponding colour
lactose fermenter (red), others (yellow)
Lactose fermenters (3)
Klebsiella, Escherichia coli, Enterobacter
Agar for Escherichia coli O157:H7
Sorbital MacConkey agar
Name of XLD agar.
Properties XLD agar is differentiating and the corresponding colour.
Xylose lysine deoxycholate agar
Shigella (xylose non-fermenter, red), Salmonella (H2S producer, red with black spots), others (xylose fermenters, yellow)
Agar for Vibrio spp.
TCBS agar +/- alkaline peptone enhancement
Properties TCBS agar is differentiating and the corresponding colour
sucrose fermentation
Vibrio cholerae (yellow (F)), Vibrio parahaemolyticus (green (NF))
Kidney bean-shaped diplococci
Neisseria spp.
Which Neisseria is glucose fermenting only?
Neisseria gonorrhoeae
Which Neisseria causes neonatal conjunctivitis?
Neisseria gonorrhoeae
Agar for Neisseria species (2)
Chocolate agar, Thayer Martin agar
Which Neisseria is found in nasopharynx normally?
Neisseria meningitidis
Which Neisseria is both glucose and maltose fermenting?
Neisseria meningitidis
Which bacteria require rifampicin for close contacts as prophylaxis? (2)
Neisseria meningitidis, Haemophilus influenzae
Abx prophylaxis for close contact of Neisseria meningitidis
Rifampicin / ceftriaxone / ciprofloxacin
Strains of Neisseria meningitidis that are targeted by vaccination
A, C, Y, W135 (B for teens)
GN cocci shown as coccobacilli
Moraxella catarrhalis
Enterobacteriaceae (9)
Escherichia coli, Klebsiella, Enterobacter, Serratia, Citrobacter, Proteus, Shigella, Salmonella, Yersinia
Oxygen tolerance of Enterobacteriaceae
facultative anaerobes
Biochemistry of enterobacteriaceae (glucose, oxidase)
glucose fermenter, oxidase negative
3 antigens for enterobacteriaceae
O (component of LPS), K (capsule), H (flagella)
Pathogen as indicator of fecal contamination in water
Escherichia coli
Pathogen with watery capsule, giving mucoid colonies in culture
Klebsiella
Non-motile enterobacteriaceae
Klebsiella, Shigella
Pathogen showing clear orange colonies
Serratia
Pathogen fermenting citrate
Citrobacter
Pathogen swarming on agar surface
Proteus
GNR producing urease (3)
Proteus, Helicobacter pylori, Klebsiella
Pathogen for staghorn stone / struvite stone
Proteus
Pathogen for bacillary dysentery
Shigella
Most pathogenic Shigella
Shigella dysenteriae
Least pathogenic Shigella
Shigella sonnei
Enterobacteriaceae that is a xylose non-fermenter
Shigella
Enterobacteriaceae that produces H2S (2)
Salmonella, Proteus
Pathogens for typhoid fever (2)
Salmonella typhi, Salmonella paratyphi
GN bacteria family that are in comma shape and halophilic
Vibrionaceae
Serogroups of Vibrio cholerae (3)
O1 classical, O1 El Tor, O139 Bengal
Leading cause of diarrhoea in Japan
Vibrio parahaemolyticus
Seagull shaped pathogen
Campylobacter jejuni
Pathogen best grown at 42 degree Celsius and is microaeropilic
Campylobacter jejuni
Pathogen giving “tear-drop” colonies in Skirrow medium
Campylobacter jejuni
Culture medium for Campylobacter jejuni
Skirrow medium
Microaerophilic GNR (2)
Campylobacter jejuni, Helicobacter pylori
Pathogen producing pyoverdin and pyocyanin
Pseudomonas aeruginosa
Pathogen producing sweet grape-like scent
Pseudomonas aeruginosa
Coccobacillary GNB (3)
Moraxella catarrhalis, Acinetobacter baumannii, Haemophilus influenzae
Non-motile MDR GNR
Acinetobacter baumannii
Growth requirement of Haemophilus influenzae
X factor (haemin), V factor (NAD)
Culture methods for Haemophilus influenzae (2)
Chocolate agar, Satellitism (with S. aures)
Most virulent serotype of Haemophilus influenzae
b
Pathogen for pertussis
Bordetella pertussis
Agar for Bordetella pertussis
Bordet-Gengou agar
Pathogen commonly causing outbreak via air-conditioning systems
Legionella pneumophila
Agar for Legionella pneumophila
BCYE agar
Pathogen for plague
Yersinia pestis
3 types of plague
bubonic, septicaemic, pneumonic
Antigen in serology for Yersinia pestis
F1 antigen
Abx for Yersinia pestis
Streptomycin, Gentamicin, Doxycycline
(DGS)
Pathogen for undulant fever
Brucella spp.
Treatment for Brucella
doxycycline + rifampicin for 6 weeks
Pathogen in concern for cat or dog bite
Pasteurella multocida
Pathogen for cat scratch disease
Bartonella henselae
Agar for obligate anaerobes (2)
BHIA, blood agar with vitamin K1
Broth for obligate anaerobes
Thioglycolate broth
Pathogen with tennis racket / drumstick appearance
Clostridium tetani
Obligate anaerobe with terminal spores
Clostridium tetani
Toxin of Clostridium tetani and pathogensis
tetanospasmin. Retrograde axonal transport via motor neurons to CNS –> - inhibitory neurons
Pathogen for tetanus
Clostridium tetani
Obligate anaerobe with sub-terminal spores
Clostridium botulinum
Toxin of Clostridium botulinum and pathogenesis
Botulinum toxin. Irreversibly block ACh release at NMJ
Pathogen for food poisoning by preserved food
Clostridium botulinum
Pathogen showing double zone haemolysis
Clostridium perfringens (inner beta, outer alpha)
Pathogen for gas gangrene
Clostridium perfringens
Pathogen for wound infection showing crepitus
Clostridium perfringens
Pathogen for post-antibiotic pseudomembranous colitis
Clostridium difficile
Bacteria showing filamentous rods
Actinomyces israelii
Pathogen with molar tooth-like colonies
Actinomyces israelii
Pathogen giving sulphur granules as micro-colonies
Actinomyces israelii
Pathogen for genital infection associated with IUD
Actinomyces israelii
GPC being obligate anaerobe
Peptostreptococcus spp.
GNR family being obligate anaerobe
Bacteroidaceae
Which GNR family is found the most in GI tract?
Bacteroidaceae
GNC being obligate anaerobe
Veillonella spp.
Life cycle of Chlamydia
Elementary bodies (EB) taken up by cells –> differentiate into reticular bodies (RB) –> RBs divide and some reform into EBs –> EBs release
Which obligate intracellular parasite has tropism to columnar epithelium?
Chlamydia
Abx for Chlamydia
Doxycycline, azithromycin
MC bacterial cause of STD
Chlamydia trochomatis
3 serovars of Chlamydia trachomatis and their serotypes
Ocular serovar (A~C), Oculogenital serovar (D~K), LGV serovar (L1~3)
Pathogen for trochoma
Chlamydia trochomatis ocular serovar
Which disease does Chlamydia trachomatis serotypes L1~3 cause?
Lymphogranuloma venereum
Pathogen for atypical pneumonia transmitted from birds
Chlamydia psittaci
Pathogenesis of Rickettsia
infect endothelial cells of small blood vessels & capillaries –> vasculitis –> small haemorrhage / thrombi
Common presentations of Rickettsia diseases (3)
rash + fever + headache
Test for Ricketssia using Proteus antigens
Weil-Felix test
Weil-Felix test result for rocky mountain spotted fever
OX-2, OX-19
Weil-Felix test result for epidemic typhus or endemic typhus
OX-19
Weil-Felix test result for scrub typhus
OX-K
Serology test for Rickettsia
indirect immunofluorescence test
Abx for Rickettsia
doxycycline
Rickettsia epidemic in US
Rickettsia rickettsii
Pathogen for rocky mountain spotted fever
Rickettsia rickettsii
Which vector transmits Rickettsia rickettsii?
tick
Rash features of rocky mountain spotted fever
starting from wrists, ankles, soles & palms
Pathogen for epidemic typhus
Rickettsia prowazekii
Pathogen for Brill-Zinsser disease
Rickettsia prowazekii
Which vector transmits Rickettsia prowazekii?
louse
Rash features of epidemic typhus
starting from upper trunk, sparing soles & palms
Pathogen for endemic / murine typhus
Rickettsia typhi
Which vector transmits Rickettsia typhi?
flea
Rickettsia epidemic in Southeast Asia
Orientia tsutsugamushi
Which vector transmits Orienta tsutsugamushi?
larvae of mite
Pathogen for scrub typhus
Orientia tsutsugamushi
Pathogen for Q fever
Coxiella burnetii
Pathogen for atypical pneumonia caused by inhalation of aerosols of animal products
Coxiella burnetii
Pathogen for culture negative endocarditis
Coxiella burnetii
Treatment for Helicobacter pylori associated gastritis
Triple therapy – Amoxicillin + Clarithromycin + PPI
Pathogen with filamentous haemagglutinin (FHA)
Bordetella pertussis
Pathogen with tracheal cytotoxin
Bordetella pertussis
Virulence factors for Vibrio cholerae (4)
- H antigen (motile)
- Mucinase (digesting mucous layer)
- Fimbriae (for attachment)
- Cholera toxin
Pathogen producing mucinase
Vibrio cholerae
Pathogen with M protein (function)
Streptococcus pyogenes
Inhibit complement activation to avoid phagocytosis
Pathogen with streptolysin O (function)
Streptococcus pyogenes
Destroy red and white cells
Pathogen with listeriolysin O (function)
Listeria monocytogenus
Escape from phagolysosomes of macrophages
Pathogen with Panton-Valentine Leukocidin (PVL)
MRSA
Pathogen with elastase
Pseudomonas aeruginosa
Pathogen with pneumolysin
Streptococcus pneumoniae
Examples of bacteria with pili / fimbriae (4)
Neisseria spp., Escherichia coli, Vibrio cholerae, Bordetella pertussis…
Examples of pathogens with capsule (6)
(some killers have pretty nice capsules)
Strep. pneumoniae
Klebsiella pneumoniae
Haemophilus influenzae
Pseudomonas aeruginosa
Neisseria meningitidis
Cryptococcus neoformans
Bacteria that can form endospore (2)
Bacillus, Clostridium
Bacteria that produce biofilm
S. epidermidis
Facultative intracellular parasites (6)
GP: Listeria monocytogenes,
GN: Salmonella typhi, Yersinia, Legionella, Brucella
Atypical: Mycobacterium
What does sorbitol MacConkey agar differentiate? (Colour)
Yellow: non-fermenter => EHEC
Red: fermenter => other E. coli
Antibiotics for Legionella pneumophila
Levofloxacin + Azithromycin
(L egionell A)
Treatment for Q fever (What if there is endocarditis?)
Doxycycline
[endocarditis] Doxycycline + Hydroxychloroquine for 18w
Diagnosis of Q fever
serology (IgG)
Which family of bacteria has an additional outer membrane (so is called “stealth” organisms) and has an endo-flagella / periplasmic flagella for movement?
Spirochetes
Pathogen for Lyme disease
Borrelia burgdorferi
Pathogen for erythema chronicum migrans
Borrelia burgdorferi
Diagnosis and treatment of Lyme disease
Serology (IgM)
Doxycycline, Amoxicillin
Which pathogen is commonly transmitted by urine of infected animals like rodents?
Leptospira interrogans
Which pathogen is participants of “adventure racing” and kayaking susceptible from?
Leptospira interrogans
Pathogen of Weil’s disease (What is it?)
Leptospira interrogans
(icteric leptospirosis)
2 phases of leptospirosis
- Acute / leptospiraemia phase
- Immune / leptospiuric phase
Diagnosis and treatment of leptospirosis
Dx: Leptospiral microscopic agglutination test (LMAT)
Tx: Penicillin G, doxycycline
Prevention of leptospirosis (3)
vaccination of livestocks
↓ exposure
rodent control
Pathogen with “fried egg” colonies
Mycoplasma spp.
Which non-motile bacterial family has a cell wall with high lipid content?
Mycobacterium
Ziehl & Neelsen stain preparation procedure (5)
- Heat fixation
- Add carbol-fuchsin
- Heat
- Add acid-alcohol (dissolve other bacteria)
- Add malachite green (counter stain)
Cultures for mycobacterium (time)
Solid: Lowenstein-Jensen medium
Liquid: broth
Transmission of leprosy (2)
respiratory, direct contact
Presentations of leprosy (2)
Lepromatous leprosy, Tuberculoid leprosy
Pathogen of leprosy
Mycobacterium leprae
Classificaiton of non-tuberculous mycobacterium (Name, 4 types)
Runyon classification
I. Photochromogens
II. Scotochromogens
III. Non-chromogens
IV: Rapid growers
Examples of rapid growers in mycobacteria (3)
M. fortuitum, M. abscessus, M. chelonae
Examples of slow growers in non-tuberculous mycobacteria (4)
M. avium complex, M. kansaii, M. marinum, M. ulcerans
Pathogen for fish tank granuloma
M. marinum
Pathogen for Buruli ulcer
M. ulcerans
Species of Brucella (3)
B. melitensis, B. abortus, B. suis
Pathogens transmitted by flea (2)
Yersinia pestis, Rickettsia typhi
Functions of Clostridium difficile toxins A and B
A: attract neutrophils and monocytes
B: degrade epithelial cells
Potential bioweapons (5)
anthrax, plaque, botulism, viral haemorrhagic fevers, tularemia 兔熱
Lancet-shaped diplococci
Streptococcus pneumoniae
Potassium tellurite agar / Albert stain
Corynebacterium diphtheriae
Antibiotics for Bacillus anthracis
Ciprofloxacin, Doxycycline
How to differentiate between CNSS?
S. epidermidis, S. saprophyticus
Novobiocin susceptibility: (S; R)
Mannitol fermentation: (-; +)
How to differentiate between beta-hemolytic Streptococcus?
Strep. pyogenes, Strep. agalactiae
Bacitracin susceptibility: (S; R)
How to differentiate between alpha-hemolytic Streptococcus?
Strep. pneumoniae, Strep. viridans
Optochin susceptibility: (S; R)
Which enterococcus spp. is resistant to both vancomycin and teicoplanin?
Enterococcus faecium
NTM that cause ulcers (4)
M. marinum, M. ulcerans, M. fortuitum, M. abscessus
NTM that cause pulmonary disease (3)
M. avium complex, M. kansasii, M. abscessus
NTM that cause disseminated disease in immunocompromised
M. chelonae
How to confirm Enterococcus?
Aesculin hydrolysis test (+ve: from brown to black)
Alternative of coagulase test
DNase test
Chinese character like on Gram stain
Corynebacterium diphtheriae
Special test for Corynebacterium diphtheriae
Elek test
Special test for Clostridium perfringens
Nagler test