Bacteria.txt

Card Set Information

Author:
emm64
ID:
137255
Filename:
Bacteria.txt
Updated:
2012-03-21 22:30:20
Tags:
Micro Bacteria
Folders:

Description:
Micro bacteria
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user emm64 on FreezingBlue Flashcards. What would you like to do?


  1. Staphylococci (Clusters)
    •  Grape-like clusters
    •  Normal human flora
    •  Opportunistic pathogens
    • • Skin, soft tissues, bones, and urinary tract
    •  Species:
    • Staphylococcus Aureus
    • Staphylococcus Epidermidis
    • Staphylococcus Saprophyticus
  2. Staphylococcus Aureus
    • catalase +
    • Coagulase +
    • B-hemolytic yellow colonies
    • Mannitol Fermentation
    • Novobiocin Sensitive
    • o Most frequently isolated nosocomial pathogen (hospital-acquired infection)
    • o Virulence Factors:
    •  Cytotoxins: toxic for many cell types
    •  Exfoliative Toxins: serine proteases in two forms, ETA (heat stable) and ETB (heat labile, A/B toxin)
    • • Causes Staphylococcal scaleded skin syndrome (SSSS)
    •  Enterotoxins: heat stable, superantigen
    • • Responsible for food-poisoning and sometimes toxic shock
    • Toxic Shock Syndrome Toxin-1 (TSST-1): heat stable, superantigen
    • • Causes toxic shock
    •  Enzymes:
    • • Coagulase
    • • Catalase
    • • Hyaluronidase
    • • Staphylokinase
    • • Lipase
    • Nuclease (useful in identifying S. aureus)
    • • Penicillinase
    •  Structural Components:
    • • Glycocalyx (inhibits phagocytosis)
    • • Peptidoglycan (endotoxin-like activity)
    • • Teichoic acids (promote bacterial adherence)
    • Protein A (ONLY IN S. aureus)
    • o Diseases:
    •  Cutaneous infection (most common)
    • • Impetigo
    • • Folliculitis
    • • Carbuncles
    • • Wound infection
    •  toxin-mediated syndromes
    • • Food poisoning: contaminated with heat stable enterotoxins
    • • SSSS (Riter’s): caused by exfoliative toxins
    • • Toxic-Shock: caused by TSST-1
    •  systemic diseases
    • • Bacteremia: spread of bacteria into the blood from a focus of infection
    • o Endocarditis and osteomyelitis
    • • Pneumonia
    • Staphylococci (Clusters)
    •  Grape-like clusters
    •  Normal flora on human skin and mucous surfaces
    •  Opportunistic pathogens in humans causing a wide spectrum of diseases
    • • Skin, soft tissues, bones, and urinary tract
  3. Staphylococcus Epidermidis
    • catalase +
    • Coagulase -
    • G-hemolytic white
    • o Famous biofilm former on invasive medical devices
    • o Virulence Factor: Glycocalyx
    • o Major cuase of endocarditis in valve replacement surgery
    • Staphylococci (Clusters)
    •  Grape-like clusters
    •  Normal flora on human skin and mucous surfaces
    •  Opportunistic pathogens in humans causing a wide spectrum of diseases
    • • Skin, soft tissues, bones, and urinary tract
  4. Staphylococcus Saprophyticus
    • catalase +
    • Coagulase -
    • G-hemolytic white
    • o 2nd most common cause of UTI
    • o Use direct microscopic observation for lab diagnosis
    • Staphylococci (Clusters)
    •  Grape-like clusters
    •  Normal flora on human skin and mucous surfaces
    •  Opportunistic pathogens in humans causing a wide spectrum of diseases
    • • Skin, soft tissues, bones, and urinary tract
  5. Streptoccoi (Pairs and Chains)
    • catalase -
    •  Most abundant group in oral cavity
    •  Facultative
    •  3 overlapping classification schemes:
    • • Hemolysis
    • Lancefield grouping (used only to distinguish among the B-hemolytic species)
    • • Biochemical properties
    •  Species:
    • S. pyogenes
    • S. agalactiae
    • S. pneumoniae
    • S. bovis
  6. S. agalactiae
    • GPC
    • catalase -
    • Group B Lancefield
    • o Epidemiology: Asymptomatic colonization of female genital tract and lower gastrointestinal tract
    • o Diseases: Baby Killer!
    •  Early onset neonatal disease: Sepsis, meningitis, pneumonia
    •  Late onset neonatal disease: bacteremia with meningitis
    •  Infection in pregnant women: present as UTI
    •  Infections in other adult patients: bacteremia, pneumonia, bone and joint infections, skin and soft tissue infections
    • o Lab Diagnosis:
    • CAMP: only S. agalactiae produces the CAMP factor, will see an enhanced zone of hemolysis due to the presence of CAMP factor
    • Hippurate Hydrolysis Test: Hippuricase is produced by S. agalactiae, causes a precipitation when ferrin chloride is added
    •  Group B specific carbohydrates: polymer of rhamnose, N-acetylglucosame, and galactose
    •  Surface Protein: C protein
    • Streptoccoi (Pairs and Chains)
    • catalase -
    •  Most abundant group of bacteria in oral cavity
    •  Facultative
    •  3 overlapping classification schemes:
    • • Hemolysis
    • • Lancefield grouping (used only to distinguish among the B-hemolytic species)
    • • Biochemical properties
  7. S. pneumoniae
    • GPC
    • catalase -
    • (NO Lancefield because it is A-hemolytic)
    • o Has fastidious growth requirements
    • o Leading cause of pneumonia in adults today
    • o Virulence factors:
    •  Capsule: major virulence factor, antiphagocytic
    • • only virulent strain has capsule
    • o Epidemiology:
    •  Most infections are caused by endogenous spread (non-communicable)
    •  Person-to-person spread is extremely rare
    • o Disease:
    • Otitis Media: inflammation of the middle ear
    •  Bacterial pneumonia: inflammation of the lungs
    • Bacteremia
    • Meningitis: inflammation of the protective membranes covering the CNS (meninges)
    • o Lab Diagnosis:
    • Optochin Sensitivity Test: only pneumoniae is inhibited by Optochin
    • Bile solubility test: only pneumoniae produces amidase which lyses bile and creates a clear bacterial culture
    • Quellung: swelling of the capsule surrounding a bacterium
    • Streptoccoi (Pairs and Chains)
    • catalase -
    •  Most abundant group of bacteria in oral cavity
    •  Facultative
    •  3 overlapping classification schemes:
    • • Hemolysis
    • • Lancefield grouping (used only to distinguish among the B-hemolytic species)
    • • Biochemical properties
  8. S. bovis
    • GPC
    • catalase -
    • Group D, indicator of colon cancer
    • Streptoccoi (Pairs and Chains)
    • catalase -
    •  Most abundant group of bacteria in oral cavity
    •  Facultative
    •  3 overlapping classification schemes:
    • • Hemolysis
    • • Lancefield grouping (used only to distinguish among the B-hemolytic species)
    • • Biochemical properties
  9. Viridans Streptococci:
    • Group of about 20 members including most dental bacteria
    • o Important cause of endocarditis after dental manipulation
  10. Enterococci (diplococci)
    • Gamma Hemolytic
    •  Virulence factors:
    • Intrinsic antibiotic resistance (notorious for this genus)
    • o Resistant to many beta-lactam drugs
    • o Also vancomycin resistant
  11. Gram-Positive Bacilli
    • o Spore-Formers: Always gram positive because need the large peptidoglycan layer and cannot have outer membrane
    • o Bacillus: gram positive rods
    • • B. antracis
    • • B. cereus
  12. B. antracis
    • GPB-spore
    • spore-former
    • o Aerobic, non-motile, and G-hemolytic
    • o Causes Antrax
    • o Virulence Factors:
    •  Three exotoxins (NOT A/B toxins)
    • Protective antigen (PA)
    • • Lethal factor (LF)
    • • Edema factor (EF)
    • • NOTE: must have PA in order to be virulent
    •  Capsule: consists of D-glutamate polypeptide
    •  Spore
    • o Epidemiology: No evidence of person-to-person transmission of antrax
    • True Zoonotic Pathogen
    • o Diseases
    •  Cutaneous Anthrax (most common form)
    • • Malignant pustules form on the surface of skin after minor scratch or abrasion with bacteria
    •  Gastrointestinal Anthrax (forms ulcers)
    •  Inhaled Anthrax
    • • Most lethal
    • o Lab Diagnosis
    •  Colonies are non-hemolytic and form a Medusa-head colony
    •  Colonies are sticky
  13. B. cereus
    • GPB-spore
    • o Beta-hemolytic, motile, no capsule
    • o Major cause of food poisoning (especially refried rice, rice loving bacteria) via enterotoxins
    • o Two types of food poisoning:
    • Emetic formSuperantigen, heat stable enterotoxin
    • Diarrheal formA/B toxin, heat-labile enterotoxin
  14. Clostridium:
    • GPB gram-positive rods
    •  Most are motile, strictly anaerobic
    •  Species
    • C. perfringens (Types A-E)
    • C. tetani
    • C. botulinum
    • C. difficile
    • C. septicum
  15. C. perfringens
    • (Types A-E)
    • GPB-spore
    • o Virulence Factors:
    •  Alpha-toxin (PLC, lecithinase) (Type A contains just this toxin)
    •  Beta-toxin
    •  Epsilon-toxin
    •  Iota-toxin
    •  Enterotoxin (heatl labile)
    • o Epidemiology: Type A is responsible for most human infections in the US
    • o Diseases:
    •  Soft-Tissue infections
    • Cellulitis with gas formation
    • • Suppurtive myositis
    • • Myonecrosis (gas gangrene)
    •  Gastroenteritis
    • • Food Poisoning: caused by enterotoxin-producing Type A
    • • Necrotizing enteritis (pig-bel): caused by Type C strain
    • o Lab Diagnosis:
    •  culture on agar plate with egg yolk
    • • Alpha-toxin interacts with egg yolk to produce characteristic precipitate around colonies
    • Double Zone of Hemolysis: small area of beta hemoysis surrounded by large area of alpha hemolysis
    • Clostridium: gram-positive rods
    • GPB
    •  Most are motile, strictly anaerobic
  16. C. tetani
    • GPB-spore
    • o Form spore at end like a drumstick or tennis racket
    • o Causes Tetanus
    • o Virulence Factors:
    •  Tetanospasmin (Tetanus toxin)
    • • A/B toxin
    • o A domain blocks the release of inhibitory neurotransmitters GABA and glycine
    • o B domain binds to nerve membrane
    • o Epidemiology: Spores are found most places and exposure is often, but disease is uncommon due to vaccine
    • o Diseases:
    •  Generalized Tetanus (most common)
    • Trismus: lockjaw
    • • Sardonic Smile: risus sardonicus
    • • Back spasms: opisthotonos
    • • Muscles Spasms
    • • Systemic symptoms
    •  Localized tetanus
    •  Neonatal tetanus
    • o Lab Diagnosis
    •  Appears as a film on agar plate, not colonies
    • Clostridium: gram-positive rods
    • GPB
    •  Most are motile, strictly anaerobic
  17. C. botulinum
    • GPB-spore
    • o Etiologic agent of Botulism
    • o Virulence Factors
    •  Botulinum toxin
    • • Neurotoxin, A/B toxin
    • o A domain inhibits release of acetylcholine leading to muscle contraction
    • o Epidemiology:
    •  Home-canned foods, usually in asparagus, beets, and corn
    •  Honey
    • o Diseases:
    •  Infant Botulism: muscle weakness and breathing problems
    •  Foodborne botulism: neither emetic nor diarrheal form of food poisoning (NO enterotoxin)
    • • Drooping eyelids, slurred speech, difficulty swallowing
    •  Wound botulism
    •  Inhalation botulism
    • o Therapeutic uses of botulism toxin
    •  BOTOX!
    • Clostridium: gram-positive rods
    • GPB
    •  Most are motile, strictly anaerobic
  18. C. difficile
    • GPB-spore
    • o Virulence Factors:
    •  Exotoxin A: increases permeability of intestincal cell wall=diarrhea
    •  Exotoxin B: damages mucosa and causes pseudomembrane formation
    • o Not a food-poisoning pathogen
    • o Diseases:
    •  Exposure to antibiotics is associated with overgrowth of this and other GI diseases
    •  Antibiotic Associated Diarrhea (AAD)
    • Clostridium: gram-positive rods
    • GPB
    •  Most are motile, strictly anaerobic
  19. C. septicum
    • GPB-spore
    • o Cancer associated bacteria pathogen
    • o Indication of colon cancer
    • o Non-spore formers
    • Clostridium: gram-positive rods
    • GPB
    •  Most are motile, strictly anaerobic
  20. Listeria
    •  Gram-positve rods
    •  Motile
    •  Facultative anaerobe: can live inside or outside of the host cell
    •  Beta-hemolytic
    •  Species:
    • L. monocytogenes
  21. L. monocytogenes
    • GPB, non-spore
    • o Can grow at a broad temperature range and in a high salt concentration
    • o Faculative intracellular pathogen
    • o Causes food poisoning in refergerated and preserved foods
    •  Does not use enterotoxin
    • o Virulence Factors:
    •  Ability to grow at low temps and in high salt concentrations
    •  Able to grow inside of macrophages
    •  Factors involved in intracellular growth:
    • • Entry (internalins)
    • • Escape from phagolysosome (listeriolysin O and PLC)
    • • Multiplication
    • • Assembly of actin (ActA)
    • • Extrusion
    • o Epidemiology: disease associated with consumption of contaminated food products, newborns and immunocompromised individuals are most at risk
    • o Diseases:
    •  Neonatal Disease: high mortality rate, exposure on vaginal delivery
    •  Adult Disease: normal adults are resistant, immunosupressed people might get gastroenteritis, septicemia, meningitis
    • Listeria
    •  Gram-positve rods
    •  Motile
    •  Facultative anaerobe: can live inside or outside of the host cell
    •  Beta-hemolytic
  22. Corynebacterium
    • GPB, non-spore
    •  Aerobic
    •  Non-motile
    •  Cell wall contains short chain mycolic acid (weak acid fast)
    •  Species:
    • C. diphtheria
    • o Pleomorphic bacilli (Chinese letters)
    • o Lab Diagnosis:
    •  Metachromatic granules in cytoplasm when stained with methylene blue
    •  Tellurite agar plate: will see Te precipitating out
    •  Elek Test: tests for exotoxin either in vitro or in vivo (guinea pigs)
    • o Causes diphtheria
    • o Virulence factors:
    •  Diptheria exotoxin
    • • Classic A/B toxin that binds to EF-2 to terminate translation
    • • Toxin gene is carried by lysogenic bacteriophage (specialized transduction)
    • o Epidemiology: Humans are the only reservoir for this bacteria
    • o Diseases:
    •  Respiratory diphtheria: thick pseudomembrane in pharynx and bulk neck
    •  Cutaneous diphtheria: causes nonhealing ulcers on the skin
  23. Nocardia
    • GPB, non-spore
    •  Catalase positive
    •  Strict Aerobe
    •  Forms long branching filaments called aerial hyphae
    •  Partially (weakly) acid fast
    •  Species:
    • • N. asteroids
    • o Virulence factors:
    •  Cord factor: antiphagocytic
    • o Epidemiology: acquired by inhalation (pulmonary) or traumatic introduction (cutaneous)
    • o Diseases:
    •  Brain abscesses are most common
  24. Actinomyces
    • GPB, non-spore
    •  Catalase negative, Facultative anaerobic
    •  Form aerial hyphae
    •  NOT Acid Fast
    •  Diseases:
    • • Chronic suppurative and granulomatous disease of face, thorax or abdominal areas
    •  Lab diagnosis: sulfur granules found in pus from lesions
  25. Propionibacterium
    • GPB, non-spore
    •  Anaerobic
    •  Produces propinonic acid as a byproduct of fermentation
    •  Species:
    • • P. acnes
    • o Most prevalent organism in the follicular flora, responsible for at least 90% of acne cases
    • o Virulence factors: all invasins
    •  Lipases
    •  Proteases
    •  Neuraminidase
    •  Hyaluronidase
  26. Neisseria
    • GNC
    •  Diplococci, kidney, coffee bean shaped bacteria
    •  Aerobic
    •  Fastidious (require complex growth media)
    •  Non-motile
    •  Species:
    • N. gonorrhoeae
    • N. meningitidis (meningococcus)
  27. N. gonorrhoeae (gonococcus)
    • • Fimbriae play a major role in adherence
    • o Only fimbriated cells are virulent
    • • A variety of outer membrane proteins
    • o Opa: opacity protein, mediates firm attachment to host cells
    • o Por
    • o Rmp
    • o LOS: similar to LPS, but doesn’t have O-antigen chain
    • • Non-capsulated
    • • Epidemiology: higher risk of disease in patients with definiciences in late components of complement (C5-C9 proteins)
    • • Diseases:
    • o Gonorrhea
    •  Characterized by purulent discharge at involved site
    •  Second most commonly reported bacterial STD in the US
    • o Ophthalmia neonatorum
    • o Disseminated infections: spread of infection from genitourinary tract through blood to skin or joints
    • • Lab Diagnosis:
    • o Thayer-Martin Agar: inhibits growth of most other organisms except Neisserias
    •  Contains: Vancomycin (kills all gram positive organisms), Colistin (kills all gram negative organisms except Neisseria), Nystatin (kills all fungi)
    • Neisseria
    • GNC
    •  Diplococci, kidney, coffee bean shaped bacteria
    •  Aerobic
    •  Fastidious (require complex growth media)
    •  Non-motile
  28. N. meningitidis (meningococcus)
    • • Has a polysaccharide capsule (antiphagocytic)
    • • Epidemiology: humans are the only natural hosts
    • o Highest incidence in children younger than 5
    • • Diseases:
    • o Meningococcal meningitisBaby Killer
    •  Second most common cause of meningitis
    • o Meningococcemia: results in amputation of legs and arms
    • • Lab Diagnosis:
    • o Cerebrospinal fluid
    • o Thayer-Martin Agar
    • Neisseria
    • GNC
    •  Diplococci, kidney, coffee bean shaped bacteria
    •  Aerobic
    •  Fastidious (require complex growth media)
    •  Non-motile
  29. E. coli
    • • Motile and lactose fermentor
    • • Over 700 antigenic types recognized based on the three antigens
    • • Virulence factors:
    • o Adhesins
    • o Exotoxins:
    • Shiga toxins (A/B toxin)• Interacts with ribosomes to inhibit protein synthesis• Causes hemolytic uremic syndrome
    • Shiga-like toxins (A/B toxin)
    • Heat-labile enterotoxins (LT) (A/B toxin)
    •  Heat-stable enterotoxins (ST)superantigen
    •  Hemolysinforms pores in cell membrane of blood cells
    • • Epidemiology:
    • o Most common aerobic, gram- rods in the GI tract
    • o Important nosocomial pathogen
    • o Generally acquired exogenously in contaminated food and water, causes food poisoning
    • • Diseases:
    • o Extra-intestinal diseases:
    •  UTI
    •  Septicemia
    •  Neonatal meningitis
    • Baby killer
    • o Intestinal Diseases (diarrhea)
    •  5 different pathogenic groups cause gastroenteritis
    • • ETEC: Enterotoxigenic E. colio Non-invasive, secretes heat labile and or heat stable toxinso Causes traveler’s diarrhea
    • • EAEC: Enteroaggregative E. colio Non-invasive, secretes heat stable-like toxin and hemolysin
    • • EPEC: Enteropathogenic E. colio Moderately invasive, works by the “attaching-effacing” mechanism that results in osmotic diarrheao Symptoms result mainly from invasion rather than toxigenesis
    • • EHEC: Enterohemorrhagic E. Colio Moderately invasive, secretes shiga toxin in addition to “attaching-effacing” mechanismo May complicate pediatric diarrhea with hemolytic uremia syndromeo E. coli O157:H7most common form of E. coli in the US
    • • EIEC: Enteroinvasive E. colio Invasive, facultative intracellular pathogeno Uses Type III secretion systemo Causes dysentery-like diarrhea and is potentially fatal
  30. Enterobacteriaceae Family
    • Escherichia coli
    • Salmonella
    • Shigella
    • Yersinia
    • Klebsiella
    • Proteus
    • GNB
    • o Common Characteristics:
    •  Facultative anaerobes
    •  Catalase positive and oxidase negative
    •  Share a common antigen: enterobacterial common antigen
    •  Serologic classification of this family with three major groups of antigens
    • • Capsule (K antigen)
    • • Flagellar (H antigen)
    • • Somatic O polysaccharide (O antigen)part of LPS
    •  Ability to ferment lactose or not and ability to be motile or not further subdivide this family
  31. ETEC: Enterotoxigenic E. coli
    • gastroenteritis
    • o Non-invasive, secretes heat labile and or heat stable toxins
    • o Causes traveler’s diarrhea
  32. EAEC: Enteroaggregative E. coli
    • gastroenteritis
    • o Non-invasive, secretes heat stable-like toxin and hemolysin
  33. EPEC: Enteropathogenic E. coli
    • gastroenteritis
    • o Moderately invasive, works by the “attaching-effacing” mechanism that results in osmotic diarrhea
    • o Symptoms result mainly from invasion rather than toxigenesis
  34. EHEC: Enterohemorrhagic E. Coli
    • gastroenteritis
    • o Moderately invasive, secretes shiga toxin in addition to “attaching-effacing” mechanism
    • o May complicate pediatric diarrhea with hemolytic uremia syndrome
    • o E. coli O157:H7most common form of E. coli in the US
  35. EIEC: Enteroinvasive E. coli
    • gastroenteritis
    • o Invasive, facultative intracellular pathogen
    • o Uses Type III secretion system
    • o Causes dysentery-like diarrhea and is potentially fatal
  36. Salmonella
    • GNB
    • • Motile, non-lactose fermenter
    • • Facultative intracellular pathogens
    • • Resistant to bile acids
    • • Virulence factors:
    • o Tolerant to acids in stomach
    • o Intracellular growth ability
    • o Heat-labile enterotoxin
    • • Epidemiology: primary pathogen (always associated with disease)
    • o Carried by reptiles and contaminated food products
    • o S. typhi is strict human pathogen
    • o S. enteritidis can be found in eggs and pet reptiles
    • • Diseases: Salmonellosis
    • o Enteric Fever (Typhoid Fever)
    •  Caused by S. typhi
    •  Usually includes a high fever
    • o Enteritis (acute gastroenteritis)
    •  Caused by ingestion of infected food or the organisms
    • • Lab Diagnosis: stool specimen required
  37. Shigella
    • GNB
    • • Non-motile, non-lactose fermentor
    • • Resistant to bile acids
    • • Facultative intracellular pathogen
    • • S. Dysenteriae causes the most serious diseases
    • • Virulence factors:
    • o Intracellular growth ability
    • o Shiga toxin: A/B toxin that inhibits protein synthesis and has enterotoxin effect (blocks absorption of electrolytes)
    • • Epidemiology: transmitted via the fecal-oral route and it is highly infectious
    • • Diseases:
    • o Shigellosis (bacillary dysentery)
    •  Severe diarrhea with blood
  38. Yersinia
    • GNB
    • • Motile, non-lactose fermenter
    • • Facultative intracellular pathogen
    • • Can grow at 1-4 degrees C
    • • Virulence Factors:
    • o Type III secretion system: mediate resistance to phagocytic killing
    •  Syringe-like mechanism allows them to inject virulence factors into host cells
    • • Epidemiology: Primary pathogen
    • o Y. pestis is a zoonotic infection
    • o Y. enterocolitica is acquired by eating contaminanted food especially raw or undercooked pork
    • • Diseases:
    • o Bubonic Plaque (black death)
    •  Caused by Y. pestis
    • o Gastroenteritis
    •  Caused by Y. enterocolitica
  39. Klebsiella
    • GNB
    • • Non-motile and non lactose fermentor
    • • K. pneumoniae is the most common cause of pneumonia especially in malnourished alcoholics
    • o Also a frequent UTI pathogen
  40. Proteus
    • GNB
    • • Motile and non-lactose fermenter
    • • Forms swarming colonies
    • • P. mirabilis: most common and causes UTI
    • o Produces large quantities of urease and causes stones in UT and/or kidneys
  41. Vibrio
    • o Common Characteristics:
    •  Facultative anaerobes
    •  Oxidase positive
    •  Broad range of ideal temperatures (14-40 degrees C)
    •  Very sensitive to acidic environments
    • o Species:
    • V. cholera
    • V. parahaemolyticus
    • V. vulnificus
  42. V. cholera
    • • Does not require salt for growth, but can tolerate it
    • • Etiology of cholera
    • • Virulence factors:
    • o Cholera enterotoxin (CtxA, CtxB)
    • identical to heat labile A/B toxin
    •  Increases cAMP
    •  Causes watery diarrhea
    • • Epidemiology: disease is rare because infectious dose is high-(most organisms are killed by stomach acids)
    • o Transmitted by contaminated food or water
    • • Disease:
    • o “rice-water stool”
    • o Death caused by dehydration
    • Vibrio
    • o Common Characteristics:
    •  Facultative anaerobes
    •  Oxidase positive
    •  Broad range of ideal temperatures (14-40 degrees C)
    •  Very sensitive to acidic environments
  43. V. parahaemolyticus
    • GNB
    • • Ingestion of undercooked shellfish or raw oysters
    • • Usually a self-limiting illness
    • Vibrio
    • o Common Characteristics:
    •  Facultative anaerobes
    •  Oxidase positive
    •  Broad range of ideal temperatures (14-40 degrees C)
    •  Very sensitive to acidic environments
  44. V. vulnificus
    • GNB
    • • Exposure of wounds to sea water=wound infections
    • • Salt-lover (halophillic)
    • Vibrio
    • o Common Characteristics:
    •  Facultative anaerobes
    •  Oxidase positive
    •  Broad range of ideal temperatures (14-40 degrees C)
    •  Very sensitive to acidic environments
  45. Campylobacter
    • GNB
    • o Species:
    •  C. jejuni
    • • Hippurase positive
    • • Grows at higher temperatures (42 degrees C)
    • Leading cause of bacterial gastroenteritis in the US
  46. Helicobacter
    • GNB
    • o Species:
    •  H. pylori
    • Dr. Marshall
    • Urease positive
    • • Microaerophilic
    • • Colonizes stomach at low pH
    • • Virulence factors:
    • o Flagella
    • o Mucinase
    • o Ureasefor pH maintenance
    • o Superoxide dismutase
    • o Catalase
    • • Epidemiology: humans are the primary reservoir
    • o Most common chronic bacterial infection of humans (present in half of world population)
    • • Diseases:
    • o Gastritis
    • o Duodenal and gastric ulcers
    • o Gastric adenocarcinomas (Cancer-associated bacteria)
    • • Lab Diagnosis:
    • o Urease test
    • o Carbon-14 Urea breath test
    • o Blood test (antibody detection)
  47. Haemophilus
    • GNB
    • o Non-motile
    • o Aerobic or facultative anaerobic
    • o Species:
    •  H. influenzae
    • • Typed by capsular polysaccharide with capsule swelling test
    • H. influenzae type B (Hib) clinically most virulent (responsible for 95% of disease)
    • • Virulence factors
    • o Polysaccharide capsule type B (major virulence factor of Hib)
    •  Contains polyribitol phosphate (PRP)
    • o Immunoglobulin (Ig) A1 proteases
    • • Epidemiology: Hib is an uncommon member of normal flora
    • o BUT, H. influenzae constitutes 10% of flora in saliva
    • • Disease:
    • o Infants and young children mostly affected by Hib if not vaccinated
    • Active immunization with conjugated PRP
    • –epiglottitis
    • –meningitis
    • baby killer!
    • • Lab diagnosis: NAD+ (factor V) and hemin (factor X) required for growth
    •  H. ducreyi
    • • Causes STD, chancroid, like gonorrhea, but no discharge
  48. Legionella
    • GNB
    • o L. pneumophila
    •  Aerobic gram negative rod bacteria
    •  Non-capsulated and motile
    • Facultative intracellular pathogen
    •  Main hosts are amoeba and human macrophages
    •  Virulence Factors:
    • • Produce beta-lactamase
    •  Epidemiology:
    • • Outbreaks of the disease are often correlated with the presence of amoebas because legionella form symbiotic relationships with them
    • • No person-to-person transmission
    •  Diseases: (Legionellosis)
    • • primarily affect the lung
    • • Legionnaire’s disease: severe form of pneumonia
    • • Pontiac Fever: non-pneumonic illness, an influenza-like illness, self-limiting
    •  Lab Diagnosis:
    • BCYE agar containing L-cysteine
  49. Pasteurella Multocida
    • GNB
    • o Normal flora in oropharynx of animals
    • o True zoonotic infection
  50. Bartonella henselae
    • GNB
    • o Cat-scratch disease
    • o True zoonotic infection
  51. Bordetella, Brucella, Francisella
    • o Extremely small
    • o Bordtella
  52. B. pertussis:
    • GNB
    • Bordtella
    • causes pertussis (whooping cough)
    • • Noninvasive infection of ciliated respiratory epithelial cells
    • • Virulence Factors:
    • o Adhesins: Filamentous hemagglutinin (FHA) and Pertussis toxin (A/B toxin)
    • o Toxins: Pertussis toxin and Adenylate cyclase/hemolysin toxin (A/B toxin)
    • does NOT cause bacteremia
    •  Pertussis toxin increases [cAMP], which increases respiratory secretions and mucus production
    • • Epidemiology:
    • o Person-to-person spread
    • o Non-vaccinated individuals at greatest risk (DPT vaccine)
    • • Lab Diagnosis: Bordet and Gengou (BG) agar
    •  B. parapertussis: causes milder form of pertussis
    •  B. bronchiseptica: causes bronchopulmonary disease
  53. Brucella:
    • GNB
    •  True zoonotic disease
    •  Facultative intracellular pathogen
    •  Diseases: Brucellosis (undulant fever or Malta fever)
    • Antibiotics (tetracycline)
  54. Francisella
    • GNB
    •  F. tularensis:
    • Facultative intracellular pathogen of macrophages
    • • Diseases: Causes Rabbit Fever (Tularemia)
    • o Ulceroglandular tularemia
    • o Oculoglandular tularemia
    • o Pneumonic tularemia
    • • Virulence Factors:
    • o Antiphagocytic capsule
    • o Intracellular growth ability
    • True zoonotic infection
    • o Rabbits
    • o Hard Ticks
    • • Lab Diagnosis: BCYE agar containing L-cysteine
  55. Pseudomonas aeruginosa
    • GNB
    • o The most important opportunistic pathogen of immunocompromised individuals
    • o Obligate aerobe
    • o Virulence factors:
    •  Slime layer: mucoid exopolysaccaride or alginate coat)
    •  Antibiotic resistance (β-lacatamase)
    •  Pseudomonas Exotoxin A
    • • Binds to EF-2 (A/B toxin)like diphtheria toxin
    • o Epidemiology:
    •  Nosocomial pathogen
    •  Fatality rate is 50%
    • o Diseases:
    •  Primary skin infections
    • Burn infection
    • Hot-tub rash
    •  Ear infections: “swimmer’s ear”
    •  Eye infections: contaminated contact lens cleansing fluids
    •  Pulmonary infections
    •  Urinary tract infections
    •  Bacteremia
    • o Lab Diagnosis: Culture Characterisits
    •  Grape-like odor
    •  Produce a variety of pigments
    •  Ability to grow at 42 degrees C

What would you like to do?

Home > Flashcards > Print Preview