Microbiology Quiz: Antibiotic Effectiveness and Staining
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Questions and Answers

What is the transmission route of cholera?

  • Vector-borne transmission
  • Airborne transmission
  • Fecal oral route (correct)
  • Direct contact

    • What is the characteristic shape of Vibrio cholerae?

  • Comma shaped with single polar flagellum (correct)
  • Rod shaped
  • Spiral shaped
  • Coccus shaped

    • What is a virulence factor of Vibrio cholerae?

  • H antigen (correct)
  • Peptidoglycan
  • Exotoxin
  • Lipopolysaccharide

    • What is a characteristic of the capsule of Vibrio cholerae?

    <p>It is a major virulence factor</p> Signup and view all the answers

    What is the typical appearance of Vibrio cholerae on TCBS agar?

    <p>Flat yellow colonies</p> Signup and view all the answers

    What is the recommended treatment for cholera?

    <p>Tetracycline or azithromycin</p> Signup and view all the answers

    What is a risk factor for cholera?

    <p>Asplenic patients</p> Signup and view all the answers

    What is the significance of the siderophores in Vibrio cholerae?

    <p>They are involved in iron uptake</p> Signup and view all the answers

    What is the typical habitat of Vibrio cholerae?

    <p>Lymph nodes and gallbladder</p> Signup and view all the answers

    What is the significance of the washer woman's hands sign?

    <p>It is a characteristic of dehydration</p> Signup and view all the answers

    What is the function of the mesosome in bacteria?

    <p>Cell division and secretion</p> Signup and view all the answers

    What is the main component of the bacterial capsule?

    <p>Polysaccharide</p> Signup and view all the answers

    What is the site of protein synthesis in bacteria?

    <p>Ribosome</p> Signup and view all the answers

    What is the function of the glycocalyx in bacteria?

    <p>Adherence to surfaces</p> Signup and view all the answers

    What is the function of the periplasm in bacteria?

    <p>Contains many hydrolytic enzymes</p> Signup and view all the answers

    What is the function of the pillus or fimbria in bacteria?

    <p>Adherence to surfaces</p> Signup and view all the answers

    What is the characteristic of the bacterial spore?

    <p>Has a keratin-like coat</p> Signup and view all the answers

    What is the function of beta-lactamase in bacteria?

    <p>Inactivates beta-lactam antibiotics</p> Signup and view all the answers

    Which type of bacteria are completely dependent on oxygen for ATP generation?

    <p>Obligate Aerobes</p> Signup and view all the answers

    Which enzyme helps microaerophiles to tolerate low amounts of oxygen?

    <p>Superoxide Dismutase (SOD)</p> Signup and view all the answers

    Which genus of bacteria is an example of an obligate anaerobe?

    <p>Clostridium</p> Signup and view all the answers

    Which type of anaerobes are insensitive to the presence of oxygen?

    <p>Aerotolerant anaerobes</p> Signup and view all the answers

    Which test is used to differentiate Gram positive cocci?

    <p>All of the above</p> Signup and view all the answers

    What is a characteristic of obligate anaerobes?

    <p>They produce gas in tissue</p> Signup and view all the answers

    What is a characteristic of the smell of obligate anaerobes?

    <p>Foul smelling</p> Signup and view all the answers

    Which Gram positive bacteria has a thicker, multilayer peptidoglycan in its cell wall?

    <p>Gram positive bacteria</p> Signup and view all the answers

    Which of the following is NOT a characteristic of Staphylococcus aureus?

    <p>Novobiocin sensitive</p> Signup and view all the answers

    What type of stain is used to visualize certain bacteria that do not take up the gram stain well?

    <p>Giemsa stain</p> Signup and view all the answers

    Why are obligate anaerobes difficult to culture?

    <p>They are susceptible to oxidative damage</p> Signup and view all the answers

    Which Gram positive bacteria has a thinner peptidoglycan in its cell wall?

    <p>Gram negative bacteria</p> Signup and view all the answers

    Which of the following is a characteristic of Streptococcus pneumoniae?

    <p>Alpha hemolytic</p> Signup and view all the answers

    What is the composition of the gas produced by obligate anaerobes in tissue?

    <p>CO2 and H2</p> Signup and view all the answers

    What is the function of hyaluronidase in Streptococcus?

    <p>Spreading factor, degrades hyaluronic acid</p> Signup and view all the answers

    What is the effect of Streptolysin O?

    <p>Reason for beta hemolysis, pharyngitis</p> Signup and view all the answers

    What is the characteristic of the cell wall of Gram negative bacteria?

    <p>Presence of lipopolysaccharide</p> Signup and view all the answers

    Which of the following is a characteristic of Streptococcus pyogenes?

    <p>Beta hemolytic</p> Signup and view all the answers

    What is a characteristic of Streptococcus agalactiae (GBS)?

    <p>Catalase negative, Bacitracin RESISTANT</p> Signup and view all the answers

    What is the reservoir of Streptococcus agalactiae (GBS)?

    <p>Vagina</p> Signup and view all the answers

    What is the effect of Erythrogenic Toxin?

    <p>Causes scarlet fever</p> Signup and view all the answers

    What is the significance of DNAse?

    <p>Degrades DNA in exudates or necrotic tissue</p> Signup and view all the answers

    What is the treatment for Streptococcal infections?

    <p>Penicillin G + Gentamicin</p> Signup and view all the answers

    What is the effect of Streptokinase?

    <p>Lyses fibrin, management in acute MI</p> Signup and view all the answers

    Which of the following is NOT a common symptom of Clostridium difficile infection?

    <p>Bloody diarrhea</p> Signup and view all the answers

    How is Listeria monocytogenes typically transmitted?

    <p>Through ingestion of contaminated raw milk or cheese</p> Signup and view all the answers

    What is the primary function of Listeriolysin O in Listeria monocytogenes?

    <p>To allow escape from phagolysosomes</p> Signup and view all the answers

    What is the primary mechanism of action of Clostridium difficile toxin A?

    <p>Inhibition of GTPases</p> Signup and view all the answers

    What is the typical arrangement of Corynebacterium diphtheriae cells?

    <p>In V or L shapes</p> Signup and view all the answers

    What is the primary virulence factor of Clostridium perfringens?

    <p>Alpha toxin</p> Signup and view all the answers

    What is the primary mechanism of action of the exotoxin of Corynebacterium diphtheriae?

    <p>Inhibition of protein synthesis</p> Signup and view all the answers

    What is the typical habitat of Clostridium difficile?

    <p>Human gut</p> Signup and view all the answers

    What is the primary virulence factor of Streptococcus pneumoniae?

    <p>Glycocalyx</p> Signup and view all the answers

    What is the effect of Streptococcus pneumoniae on heart valves?

    <p>Adheres to damaged heart valves</p> Signup and view all the answers

    What is the significance of catalase in Streptococcus pneumoniae?

    <p>Breaks down hydrogen peroxide</p> Signup and view all the answers

    What is the characteristic of Streptococcus pneumoniae on culture?

    <p>Medusa head morphology</p> Signup and view all the answers

    What is the treatment for Streptococcus pneumoniae infections?

    <p>Penicillin G and Vancomycin</p> Signup and view all the answers

    What is the transmission route of Streptococcus pneumoniae?

    <p>Enters through bloodstream during dental procedures</p> Signup and view all the answers

    What is the characteristic of Streptococcus pneumoniae regarding metabolism?

    <p>Catalase-negative</p> Signup and view all the answers

    What is the significance of the glycocalyx in Streptococcus pneumoniae?

    <p>Protects from host defenses</p> Signup and view all the answers

    What type of microorganism is Campylobacter jejuni?

    <p>Microaerophilic</p> Signup and view all the answers

    What is a characteristic of Campylobacter jejuni metabolism?

    <p>Microaerophilic</p> Signup and view all the answers

    What is a transmission route of Campylobacter jejuni?

    <p>Fecal-oral</p> Signup and view all the answers

    What is a virulence factor of Campylobacter jejuni?

    <p>Motile H antigen</p> Signup and view all the answers

    What is a diagnostic test for Campylobacter jejuni?

    <p>EGD with biopsy</p> Signup and view all the answers

    What is a treatment for Campylobacter jejuni infection?

    <p>Triple therapy</p> Signup and view all the answers

    What is a characteristic of Campylobacter jejuni?

    <p>Oxidase positive</p> Signup and view all the answers

    What is a complication of Campylobacter jejuni infection?

    <p>All of the above</p> Signup and view all the answers

    What type of stain is used to visualize Mycobacteria?

    <p>Carbolfuchsin</p> Signup and view all the answers

    Which of the following bacteria is an example of a facultative anaerobe?

    <p>Helicobacter pylori</p> Signup and view all the answers

    Which of the following bacteria is typically stained with a Silver Stain?

    <p>Plasmodium</p> Signup and view all the answers

    What is the characteristic of Anaerobes in terms of oxygen requirement?

    <p>They require oxygen to enter the bacterial cell</p> Signup and view all the answers

    Which of the following bacteria is an example of an obligate anaerobe?

    <p>All of the above</p> Signup and view all the answers

    Which stain is used to diagnose Whipple disease?

    <p>Periodic Acid Schiff Stain</p> Signup and view all the answers

    What is the significance of the mnemonic 'Anaerobes Cant Breath Fresh Air'?

    <p>It helps to remember the characteristics of anaerobes</p> Signup and view all the answers

    Which of the following bacteria is stained with a Periodic Acid Schiff Stain?

    <p>All of the above</p> Signup and view all the answers

    What is the primary function of mycolic acid in Mycobacterium tuberculosis?

    <p>It inhibits neutrophil migration and damages mitochondria</p> Signup and view all the answers

    Which of the following is a characteristic of Mycobacterium leprae?

    <p>It is transmitted through prolonged exposure to nasal secretions</p> Signup and view all the answers

    What is the mortality rate of inhalational anthrax if left untreated?

    <p>100%</p> Signup and view all the answers

    What is the primary mechanism of action of the cord factor in Mycobacterium tuberculosis?

    <p>It inhibits phagocytosis by macrophages</p> Signup and view all the answers

    Which of the following is a characteristic of tetanus toxin?

    <p>It is taken up at the NMJ and transported to the CNS, acting as an inhibitory neurotransmitter.</p> Signup and view all the answers

    What is the typical appearance of Mycobacterium tuberculosis in lung tissue?

    <p>Exudative and granulomatous lesions</p> Signup and view all the answers

    What is the primary habitat of Clostridium tetani?

    <p>Soil</p> Signup and view all the answers

    What is the primary treatment for Mycobacterium tuberculosis?

    <p>Isoniazid and rifampicin</p> Signup and view all the answers

    What is the characteristic of gastrointestinal anthrax?

    <p>It is caused by ingestion of spores leading to UGI ulceration, edema, and sepsis.</p> Signup and view all the answers

    Which of the following is a characteristic of Mycobacterium tuberculosis?

    <p>It is a slow-growing, acid-fast organism</p> Signup and view all the answers

    What is the primary mechanism of action of the sulfatides in Mycobacterium tuberculosis?

    <p>They inhibit phagocytosis by macrophages</p> Signup and view all the answers

    What is the virulence factor of Clostridium tetani?

    <p>Flagella, H positive</p> Signup and view all the answers

    What is the characteristic of the mass of mediastinal LN in inhalational anthrax?

    <p>It is severely enlarged and hemorrhagic.</p> Signup and view all the answers

    What is the primary site of protein synthesis in Mycobacterium tuberculosis?

    <p>Ribosomes</p> Signup and view all the answers

    What is the mortality rate of subacute bacterial endocarditis caused by S.sanguis?

    <p>20%</p> Signup and view all the answers

    What is the characteristic of brain abscess caused by S.intermedius?

    <p>It is a rare complication of bacterial meningitis.</p> Signup and view all the answers

    What is a characteristic shape of Campylobacter jejuni?

    <p>Comma shaped or S-shaped</p> Signup and view all the answers

    What is a common clinical syndrome associated with Proteus mirabilis?

    <p>UTI</p> Signup and view all the answers

    What is a characteristic of Campylobacter jejuni metabolism?

    <p>Microaerophilic</p> Signup and view all the answers

    What is a virulence factor of Campylobacter jejuni?

    <p>Urease</p> Signup and view all the answers

    What is a characteristic of Proteus mirabilis?

    <p>Urease positive</p> Signup and view all the answers

    What is a common habitat of Helicobacter pylori?

    <p>Human stomach</p> Signup and view all the answers

    What is a characteristic of Proteus mirabilis metabolism?

    <p>Facultative aerobe</p> Signup and view all the answers

    What is a virulence factor of Proteus mirabilis?

    <p>Fimbriae</p> Signup and view all the answers

    What is a characteristic of Helicobacter pylori?

    <p>Urease positive</p> Signup and view all the answers

    What is a clinical syndrome associated with Campylobacter jejuni?

    <p>Reactive arthritis</p> Signup and view all the answers

    What is the characteristic shape of Campylobacter jejuni?

    <p>Comma shaped or S-shaped with single polar flagellum</p> Signup and view all the answers

    What is the diagnosis of Campylobacter jejuni?

    <p>Skirrow's agar</p> Signup and view all the answers

    What is the treatment for Campylobacter jejuni severe cases?

    <p>Erythromycin</p> Signup and view all the answers

    What is the metabolism of Helicobacter pylori?

    <p>Microaerophilic</p> Signup and view all the answers

    What is the virulence factor of Helicobacter pylori?

    <p>All of the above</p> Signup and view all the answers

    What is the transmission of Helicobacter pylori?

    <p>Ingestion</p> Signup and view all the answers

    What is the characteristic of Proteus mirabilis?

    <p>Urease positive</p> Signup and view all the answers

    What is the clinical syndrome associated with Proteus mirabilis?

    <p>Complicated UTI associated with nephrolithiasis</p> Signup and view all the answers

    What is the diagnosis of Proteus mirabilis?

    <p>Facultative with Large polysaccharide capsule</p> Signup and view all the answers

    What is the treatment of Proteus mirabilis?

    <p>Culture guided treatment</p> Signup and view all the answers

    Study Notes

    Antibiotics and Microorganisms

    • Aminoglycoside antibiotics are ineffective against anaerobes, Trypanosomes, and Plasmodium because they require oxygen to enter the bacterial cell.
    • Silver stain is used to diagnose Helicobacter pylori, Legionella, Bartonella henselae, and fungi (e.g., Coccidioides, Pneumocystis jirovecii, Aspergillus fumigatus).
    • Periodic acid Schiff stain is used to stain glycogen, mucopolysaccharides, and is used to diagnose Whipple disease (Tropheryma whipplei).

    Anaerobes and Facultative Anaerobes

    • Anaerobes can't breathe fresh air, and examples include Clostridium, Bacteroides, Fusobacterium, and Actinomyces.
    • Mnemonic: Anaerobes Cant Breath Fresh Air.
    • Facultative anaerobes utilize oxygen if it is present, but can use fermentation in its absence.
    • Examples of facultative anaerobes include Clostridium/Clostridioides perfringens, which is a gas-forming bacterium.

    Clostridium and Corynebacterium

    • Clostridium tetani has a tennis racket, drumstick, or lollipop shape.
    • Clostridium/Clostridioides perfringens causes gas gangrene.
    • Corynebacterium diphtheria has a Chinese character, curved, non-motile shape.
    • Corynebacterium diphtheria causes diphtheria, an important cause of serious healthcare-associated and community-acquired infections.

    Staphylococcus and Streptococcus

    • Staphylococcus aureus is a facultative anaerobe, catalase positive, and coagulase positive.
    • Staphylococcus aureus has a reservoir in anterior nares and skin, and is transmitted through direct contact and fomites, contaminated food.
    • Staphylococcus aureus has virulence factors, including coagulase, leukocidin, catalase, penicillinase, hyaluronidase, and protein A.
    • Staphylococcus epidermidis is a facultative anaerobe, catalase positive, and coagulase negative.
    • Staphylococcus epidermidis has a reservoir in skin, and is transmitted through direct contact, and autoinfection.

    Helicobacter and Legionella

    • Helicobacter pylori is a curved, non-motile bacterium.
    • Helicobacter pylori is diagnosed using a silver stain.
    • Legionella pneumophila grows in chocolate yeast extract agar, and requires L-cysteine and iron.
    • Legionella pneumophila is transmitted through airconditioning systems, and has no person-to-person transmission.

    Escherichia and Shigella

    • Escherichia coli is a gram-negative rod, and is catalase positive.
    • Escherichia coli has a capsule, fimbriae, pili, and flagella, which are used for attachment, causing cystitis and pyelonephritis.
    • Escherichia coli has toxins, including endotoxin, entero toxins, and siderophores, which obtain iron from human transferrin or lactoferrin.
    • Shigella spp. has a comma-shaped with single polar flagellum, and grows as flat yellow colonies on TCBS agar.
    • Shigella spp. causes diarrhea, and has a characteristic sign, Washing Woman's Hands Sign, due to dehydration.

    Aerotolerant Anaerobes

    • Exclusively anaerobic but insensitive to the presence of oxygen
    • Cryptococcus neoformans can be stained with India ink (mucicarmine can also be used)

    Gram Positive vs. Gram Negative Bacteria Cell Walls

    • Gram positive bacteria:
      • Thicker, multilayer peptidoglycan
      • Teichoic acid present
      • Lipopolysaccharide absent
      • Periplasmic space absent
    • Gram negative bacteria:
      • Thinner peptidoglycan
      • Teichoic acid absent
      • Lipopolysaccharide present
      • Periplasmic space present

    Exotoxins and Endotoxins

    • Not mentioned in the provided text

    Gram Positive Cocci

    • In clusters: Staphylococci
      • Staphylococcus aureus: catalase positive, coagulase positive
      • Staphylococcus epidermidis: catalase positive, coagulase negative, novobiocin sensitive
      • Staphylococcus saprophyticus: catalase positive, coagulase negative, novobiocin resistant
    • In chains: Streptococci
      • Streptococcus pneumoniae: catalase negative, alpha hemolytic, bile optochin sensitive
      • Viridans streptococci: catalase negative, alpha hemolytic, bile optochin resistant
      • Streptococcus pyogenes (Group A Beta-Hemolytic Streptococci): catalase negative, beta hemolytic, bacitracin sensitive
      • Streptococcus agalactiae (Group B Beta-Hemolytic Streptococci): catalase negative, beta hemolytic, bacitracin resistant

    Gram Positive Bacilli

    • Spore-formers: living
    • Parts of a Bacteria
      • Cytoplasmic membrane: lipoprotein bilayer without sterols, site of oxidative and transport enzymes
      • Ribosome: RNA and protein in 50s and 30s subunits, protein synthesis
      • Nucleoid: DNA, genetic material
      • Mesosome: invagination of plasma membrane, participates in cell division and secretion
      • Periplasm: space between plasma membrane and outer membrane, contains many hydrolytic enzymes
      • Capsule: polysaccharide, protects against phagocytosis
      • Pillus or Fimbria: glycoprotein, for attachment and conjugation
      • Glycocalyx: polysaccharide, mediates adherence to surfaces
      • Flagellum: protein, for motility
      • Spore: keratin-like coat, dipicolinic acid, resistant to heat and chemicals
      • Plasmid: glycogen, lipids, polyphosphates, genes for antibiotic resistance and toxins
      • Granule: glycogen, lipids, polyphosphates, site of nutrients in cytoplasm

    Mechanism of Resistance: Beta-Lactamase

    • Not mentioned in the provided text

    Intracellular Organisms

    • Obligate intracellular organisms: rely on host's ATP
      • Genus Rickettsia, Chlamydia, Coxiella
    • Facultative intracellular organisms:
      • Salmonella, Neisseria, Brucella, Mycobacterium, Listeria, Francisella, Legionella, Yersinia pestis

    Antimicrobial Drugs

    • Not mentioned in the provided text

    Bacterial Metabolism

    • Aerobic metabolism:
      • Obligate aerobes: completely dependent on oxygen for ATP generation
      • Microaerophiles: use fermentation but can tolerate low amounts of oxygen
    • Anaerobic metabolism:
      • Obligate anaerobes:
        • Genus Clostridium, Bacteroides, Fusobacterium, Actinomyces
        • Lack catalase and/or superoxide dismutase and are susceptible to oxidative damage
        • Generally foul-smelling (short-chain fatty acids)
        • Difficult to culture
        • Produce gas in tissue (CO2 and H2)

    Staining Techniques

    • Gram staining: single most important initial test in bacteriology
    • Giemsa stain: for certain bacteria that do not take up the Gram stain well

    Other Microorganisms

    • Streptococcus agalactiae (GBS):

      • Metabolism: catalase negative, bacitracin resistant
      • Transmission: vagina, transvaginal and transplacental
      • Clinical syndromes: UTI in pregnant women, neonatal pneumonia, sepsis, and meningitis

    • Causative Agents of Neonatal Meningitis:

      • Group B strep, E. coli, Listeria

    • Group D Streptococci:

      • Metabolism: catalase negative, bile optochin resistant
      • Transmission: reservoir: human, urethra and female genitalia may be colonized
      • Clinical syndromes: UTI due to indwelling urinary catheter and instrumentation, biliary tract infections### Clostridium difficile

    • Caused by Clindamycin, ampicillin, 2nd-3rd gen cephalosporins

    • Nonbloody diarrhea associated with pseudomembranes

    • Toxic megacolon

    • Diagnosis: anaerobic condition, thioglycolate agar, patient's serum injection to mice causing death

    • Treatment: antitoxin, human botulism Ig, metronidazole or penicillin, supportive Tx, Botox

    Clostridium perfringens

    • Transmission: endospores, contamination of wound with soil or feces, food poisoning
    • Toxins: alpha toxin (lecinthase), splits lecithin, cleaves cell membranes
    • Clinical syndromes: gas gangrene, d/t alpha toxin, gas by anaerobic metabolism, pain
    • Diagnosis: culture under anaerobic conditions, double hemolysis on blood agar, growth on egg yolk agar
    • Treatment: wound care, penicillin, radical surgery, supportive

    Clostridium botulinum

    • Wound botulism: similar to food botulism but without GI symptoms
    • Diagnosis: anaerobic condition, thioglycolate agar, patient's serum injection to mice causing death
    • Treatment: antitoxin, human botulism Ig, metronidazole or penicillin, supportive Tx

    Corynebacterium diphtheriae

    • Metabolism: facultative anaerobe, catalase positive
    • Transmission: reservoir - throat, transmitted by respiratory droplets
    • Virulence Factors: pseudomembrane, exotoxin (from a temperate bacteriophage)
    • Clinical syndromes: diphtheria, mild sore throat with fever initially, pseudomembranes forms on the pharynx
    • Diagnosis: club/comma-shaped rods arranged in V or L, culture: potassium tellurite, modified Elek Test
    • Treatment and Prevention: antitoxin, penicillin or Erythromycin, vaccine DPT is a formalin inactivated exotoxin

    Listeria monocytogenes

    • Transmission: ingestion of contaminated raw milk or cheese from infected cows
    • Toxins: listeriolysin O (allows escape from phagolysosomes), actin rockets (propels through bacteria through one membrane to another)
    • Clinical syndromes: early onset neonatal listeriosis, granulomatosis infanseptica, late onset neonatal listeriosis, meningitis, meningoencephalitis, adult listeriosis
    • Diagnosis: rods arranged in V or L shapes, tumbling motility, culture can grow at cold enrichment to isolate from normal flora
    • Treatment and prevention: ampicillin + Gentamicin, TMP + SMX, NOT Cephalosporins

    Neisseria meningitidis

    • Metabolism: ferments both maltose and glucose, oxidase Positive on chocolate agar, grows best in high CO2
    • Transmission: URT droplets, high carriage in close quarters, dormitories, camps
    • Virulence Factors: capsule (13 serotypes), endotoxin LPS (causes blood vessel destruction and sepsis), pili (allow attachment to human Nasopharynx and undergo antigenic variation to avoid attack by immune system)

    Helicobacter Pylori

    • Damages goblet cells
    • Facultative gram-negative with peritrichous flagella
    • Swarming pattern
    • Urease positive
    • Causes peptic ulcer disease

    Pseudomonas aeruginosa

    • Metabolism: non-lactose fermenter, oxidase positive
    • Virulence factors: motile, elastase, protease, pyocyanin
    • Toxins: endotoxin, exotoxin A (similar to diphtheria toxin)
    • Clinical syndromes: burn and wound infections, hot tub folliculitis, skin graft loss, bone and cartilage infections, ear infections, pneumonia, gastrointestinal infections, ecthyma gangrenosum
    • Treatment and prevention: antipseudomonal penicillins, cephalosporins, carbapenems, fluoroquinolones

    Chlamydia trachomatis

    • Metabolism: obligate intracellular parasite
    • Transmission: sexual, passage through birth canal, hand-to-eye contact
    • Virulence factors: resistant to lysozyme
    • Clinical syndromes: trachoma, genital tract infection, neonatal pneumonia, lymphogranuloma venereum
    • Diagnosis: cytoplasmic inclusions, PCR, NAAT
    • Treatment and prevention: doxycycline, erythromycin, azithromycin, ceftriaxone

    Mycobacterium tuberculosis

    • Metabolism: slow grower, obligate aerobe, acid-fast organism
    • Transmission: inhalation of respiratory droplet nuclei
    • Virulence factors: mycolic acid, cord factor, sulfatides, wax D
    • Clinical syndromes: exudative and granulomatous lesions, primary complex, Ghon complex, reactivation tuberculosis
    • Diagnosis: acid-fast stain, PCR, NAAT
    • Treatment and prevention: antituberculous medications, vaccination

    Bacteroides fragilis

    • Metabolism: anaerobe, capsule, pili
    • Transmission: predominant anaerobe of human colon
    • Virulence factors: lipopolysaccharide, capsule
    • Clinical syndromes: abdominal abscess, peritonitis, pericarditis, endocarditis, cerebral abscess
    • Diagnosis: anaerobic gram-negative
    • Treatment and prevention: metronidazole, chloramphenicol

    Mycobacterium leprae

    • Transmission: prolonged exposure to nasal secretions with lepromatous form
    • Clinical syndromes: leprosy, Hansen disease
    • Diagnosis: PCR, biopsy
    • Treatment and prevention: antileprotic medications, vaccination

    Neisseria meningitidis

    • Resistant to colistin, most saprophytic species of Neisseria susceptible

    Bordetella pertussis

    • Transmission: via respiratory droplets
    • Virulence Factors:
      • Capsule
      • Beta lactamase
      • Filamentous hemagglutinin mediates attachment
    • Toxins:
      • Pertussis Toxin: ADP ribosylation activates G proteins
      • Extracytoplasmic adenylate cyclase: inhibits phagocytosis
      • Tracheal cytotoxin: kills epithelial cells and paralyzes cilia
    • Clinical syndromes: whooping cough, paroxysmal pattern of hacking coughs
    • Diagnosis:
      • Nutritionally fastidious
      • Pleomorphic
      • Poorly gram-negative rods
    • Treatment and Prevention:
      • Azithromycin
      • Levofloxacin
      • Doxycycline
      • Reducing cigarette and alcohol consumption
      • High temperatures and hyperchlorination in hospital water supply

    Escherichia coli

    • Metabolism:
      • Indole Positive
      • Lactose fermenter on EMB and MacConkey agar
      • Green metallic sheen on EMB
      • Triple Sugar Iron Agar shows acid with gas and no H2S production
    • No H2S production

    Shigella

    • Biochemically inert enterobacteriaceae
    • Transmission: infection
    • Shigella is usually non-chalant since gastrectomy or use of antacids lowers infectious dose significantly
    • Symptoms: N/V, abdominal pain, and nonbloody diarrhea
    • Reactive arthritis (Reiter syndrome): triad of Uveitis, Urethritis, Arthritis
    • Diagnosis: comma-shaped or S-shaped with single polar flagellum
    • Treatment and Prevention: symptomatic treatment, Erythromycin for severe cases

    Campylobacter jejuni

    • Necrotizing Pneumonia
    • Usually nosocomial with thick bloody sputum
    • UTI
    • Sepsis

    Haemophilus influenzae

    • Facultative with large polysaccharide capsule
    • Currant jelly sputum
    • Treatment and Prevention: culture-guided treatment, Cephalosporins +/- Aminoglycosides

    Proteus mirabilis

    • Metabolism:
      • Urease positive
      • Indole negative
      • Non-lactose fermenter
    • Virulence Factors:
      • Motile
      • Fimbriae for adherence
      • LPS
      • Urease production
    • Clinical syndromes:
      • Complicated UTI associated with nephrolithiasis
      • Sepsis

    Helicobacter pylori

    • Metabolism:
      • Microaerophilic
      • Oxidase positive
      • Catalase positive
      • Urease positive
      • Triple positive
    • Transmission: ingestion, habitat: human stomach
    • Virulence Factors:
      • Urease produces ammonia makes the environment alkaline

    Neisseria meningitidis

    • Resistant to colistin, most saprophytic species of Neisseria susceptible

    Bordetella pertussis

    • Transmission: via respiratory droplets
    • Virulence Factors:
      • Capsule
      • Beta lactamase
      • Filamentous hemagglutinin mediates attachment
    • Toxins:
      • Pertussis Toxin: ADP ribosylation activates G proteins
      • Extracytoplasmic adenylate cyclase: inhibits phagocytosis
      • Tracheal cytotoxin: kills epithelial cells and paralyzes cilia
    • Clinical syndromes: whooping cough, paroxysmal pattern of hacking coughs
    • Diagnosis:
      • Nutritionally fastidious
      • Pleomorphic
      • Poorly gram-negative rods
    • Treatment and Prevention:
      • Azithromycin
      • Levofloxacin
      • Doxycycline
      • Reducing cigarette and alcohol consumption
      • High temperatures and hyperchlorination in hospital water supply

    Escherichia coli

    • Metabolism:
      • Indole Positive
      • Lactose fermenter on EMB and MacConkey agar
      • Green metallic sheen on EMB
      • Triple Sugar Iron Agar shows acid with gas and no H2S production
    • No H2S production

    Shigella

    • Biochemically inert enterobacteriaceae
    • Transmission: infection
    • Shigella is usually non-chalant since gastrectomy or use of antacids lowers infectious dose significantly
    • Symptoms: N/V, abdominal pain, and nonbloody diarrhea
    • Reactive arthritis (Reiter syndrome): triad of Uveitis, Urethritis, Arthritis
    • Diagnosis: comma-shaped or S-shaped with single polar flagellum
    • Treatment and Prevention: symptomatic treatment, Erythromycin for severe cases

    Campylobacter jejuni

    • Necrotizing Pneumonia
    • Usually nosocomial with thick bloody sputum
    • UTI
    • Sepsis

    Haemophilus influenzae

    • Facultative with large polysaccharide capsule
    • Currant jelly sputum
    • Treatment and Prevention: culture-guided treatment, Cephalosporins +/- Aminoglycosides

    Proteus mirabilis

    • Metabolism:
      • Urease positive
      • Indole negative
      • Non-lactose fermenter
    • Virulence Factors:
      • Motile
      • Fimbriae for adherence
      • LPS
      • Urease production
    • Clinical syndromes:
      • Complicated UTI associated with nephrolithiasis
      • Sepsis

    Helicobacter pylori

    • Metabolism:
      • Microaerophilic
      • Oxidase positive
      • Catalase positive
      • Urease positive
      • Triple positive
    • Transmission: ingestion, habitat: human stomach
    • Virulence Factors:
      • Urease produces ammonia makes the environment alkaline

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