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Clinical Bacteriology Flashcards

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1
Q

Gram + cocci antibiotic tests: Streptococci

A

Optochin - Viridans is Resistant; Pneumoniae is Sensitive
OVRPS (overpass)
Bacitracin - Group B strep are resistant; group A strep are Sensitive
B-BRAS

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2
Q

Alpha hemolytic bacteria

A

Gram + cocci
Partial reduction of hemoglobin causes greenish or brownish color without clearing growth on blood agar
Strep pneumo (catalase -, optochin sensitive)
Viridans strep (catalase -, optochin resistant)

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3
Q

Beta hemolytic bacteria

A

Gram + cocci
Complete lysis of RBCs –> clear area surrounding colony on blood agar
Staph aureus (catalase & coagulate +)
Strep pyogenes - group A (catalase -, bacitracin sensitive)
Strep agalctiae - Group B (catalase -, bacitracin resistant)

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4
Q

Staphylococcus aureus

A

Gram + bacteria, beta-hemolytic, catalase +, coagulase +, cocci in clusters
VFs: protein A binds Fc-IgG inhibiting complement activation and phagocytosis
Commonly colonizes in nares

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5
Q

Staphylococcus aureus: Inflammatory disease

A

Skin infections, organ abscesses, pneumonia (often after influenza virus infection), endocarditis, septic arthritis, and osteomyelitis

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6
Q

Staphylococcus aureus: Toxin mediated disease

A

Toxic shock syndrome (TSST-1), scalded skin syndrome (exfoliative toxin), rapid onset food poisoning (enterotoxins)
TSST-1: Superantigen that binds to MHC II and TCR, resulting in polyclonal TC activation
TSS presents as fever, vomiting, rash, desquamation, shock, end-organ failure, increased AST, ALT & bilirubin. Associated with prolonged use of vaginal tampons or nasal packaging
Food poisoning due to ingested preformed toxin –> short incubation period followed by non-bloody diarrhea and emesis (enterotoxin is heat stable)

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7
Q

Staphylococcus aureus: MRSA

A

Methicillin-resistant S aureus infection - important cause of serious nosocomial and community acquired infections
Resistant to methicillin and nafcillin because of altered penicillin binding protein

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8
Q

Staphylococcus epidermidis

A

Gram +, catalase +, coagulase -, urease + cocci clusters. Novobiocin sensitive
Found in normal flora of the skin; contaminates blood cultures
Infects prosthetic devices (hip implant, heart valve) and IV catheters by producing adherent bio films

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9
Q

Staphylococcus saprophyticus

A

Gram +, catalase +, coagulase -, urease + cocci in clusters. Novobiocin resistant
Found in normal flora of female genital tract and perineum
Second most common cause (after E.coli) of uncomplicated UTI in young women

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10
Q

Streptococcus pneumoniae

A

Gram +, lancet shaped diplococci. Alpha-hemolytic Optochin sensitive (different from S.viridans)
VFs: encapsulated, IgA protease
Most common cause of: meningitis, otitis media (children), pneumonia, sinusitis
Associated with “rusty” sputum, sepsis in pts with sickle cell disease and splenectomy

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11
Q

Streptococcus Viridans group

A

Gram +, alpha hemolytic cocci. Optochin resistant (different from S.pneumo)
Found in the normal flora of the oropharynx that cause dental caries (strep mutans and strep mitis) and subacute bacterial endocarditis at damaged heart valves (S.sanguinis - makes dextran so which bind to fibrin-platelet aggregates on damaged heart valves).
live in the mouth because they are not afraid of-the-chin (op-to-chin resistant)

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12
Q

Streptococcus pyogenes (Group A)

A

Gram + cocci, beta hemolytic, bacitracin sensitive, pyrrolidonyl arylamidase (PYR) +
Cause: pyogenic (pharyngitis, cellulitis, impetigo, erysipelas), toxogenic (scarlet fever, toxic shock like syndrome, necrotizing fasciitis), immunologic (rheumatic fever, glomerulonephritis)
Abs to M protein enhance host defenses against S.pyogenes but can give rise to RF
ASO tigers detects recent S.pyogenes infection

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13
Q

S.pyogenes and rheumatic fever

A 
JONES criteria
Joints: polyarthritis
O: heart, carditis
Nodules: subcutaneous
Erythema margin atom
Sydenham chorea
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14
Q

S.pyogenes and Scarlet Fever

A

Blanching, sandpaper like body rash, strawberry tongue, and circumoral pallor in the setting of group A strep pharyngitis (erythogenic toxin +)

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15
Q

Streptococcus agalctiae (group B streptococci)

A

Gram+ cocci, bacitracin resistant, beta-hemolytic (Hippurate test +, PRY -)
Colonizes vagina; causes pneumonia, meningitis and sepsis mainly in babies (screen pregnant women at 35-37 weeks of gestation. Pts with positive culture receive intrapartum penicillin prophylaxis
Produces CAMP factor, which enlarges the are of hemolysis formed by S.aureus

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16
Q

Streptococcus bovis

A

Gram+ cocci
Colonizes the gut
S.gallalyticus can cause bacterimia and subacute endocarditis (associated with increased risk in pts with CRC) and colon cancer
Bovis in the Blood = Cancer in the Colon

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17
Q

Enterococci

A

Gram+ cocci, catalase -, PYR+, variable hemolysis
enterococci (E.faecalis and E.faeciium) are normal colonic flora that are penicillin G resistant and cause UTI, biliary tract infections and subacute endocarditis (following GI/GU procedures)
VRE (vancomycin resistant enterococci) are an important cause of nosocomial infection
Enterococci can grow in 6.5% NaCl and bile

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18
Q

Bacillus anthracis

A

Gram + spore forming rod that produces anthrax toxin

The only bacteria with a polypeptide capsule (contains D-glutamate)

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19
Q

Cutaneous anthrax

A

Painless papule surrounded by vesicles –> ulcer with black eschar (painless and necrotic) –> uncommonly progresses to bacteremia and cell death

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20
Q

Pulmonary anthrax

A

Inhalation of spores –> flu-like symptoms that rapidly progress to fever, pulmonary hemorrhage, mediastinitis and shock
Also known as woolsorter’s disease

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21
Q

Bacillus cereus

A

Gram + rod
Causes food poisoning. Spores survive cooking rice, keeping rice warm results in germination of spores and enterotoxin formation (AKA reheated rice syndrome)
Emetic type: usually seen with rice and pasta, nausea and vomiting within 1-5 hours. Caused by cereulide (preformed toxin).
Diarrheal type: water, non-bloody diarrhea and GI pain within 8-18 hours.

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22
Q

Clostridia

A

Gram + spore forming, obligate anaerobic rods

Two types of exotoxins (C.tetani, C.botulinum)

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23
Q

Clostridium tetani

A 
Produces tetanospasmin (exotoxin) causing tetanus
Tetanus toxin (and botulinum toxin) are pro teases that cleave SNARE proteins for neurotransmitters. Blocks the release of inhibitory neurotransmitters, GABA & glycine, from Renshaw cells in the spinal cord
Causes spastic paralysis, trismus (lockjaw), risks sardonicus (raised eyebrows with an open grin)
Prevent with tetanus vaccine, treat with antitoxin +/- vaccine booster, diazepam and wound debridement
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24
Q

Clostridium botulinum

A

Produces a heat-labile toxin that inhibits ACh release at the neuromuscular junction, causing botulism
In adults, disease is caused by ingestion of preformed toxin. In babies - the ingestion of spores (e.g. Honey) leading to floppy baby syndrome.
Treat with antitoxin

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25
Clostridium perfringes
Produces alpha toxin (lecithinase, a phospholipase) that can cause myonecrosis (gas gangrene) and hemolysis *PERFringens PERForates a gangrenous leg* Spores can survive in undercooked food; when ingested, bacteria release heat-labile enterotoxin --> food poisoning
26
Clostridium difficile
Produces two toxins: Toxin A (enterotoxin) that binds to the brush border of the gut. Toxin B (cytotoxin), causes cytoskeleton disruption via actin depolymerization --> diarrhea --> pseudomembranous colitis Often secondary to antibiotic use, especially clindamycin or ampicillin; associated with PPI use. Diagnosis: detection of one or both toxins in stool by PCR Tx: metronidazole, oral vacomycin. For recurrent cases, consider repeating prior regiment, fidaxomicin or fecal microbiota transplant
27
Corynebacterium diphtheriae
Gram + rod (club shaped), black colonies on cystine-telluride agar Causes diphtheria via Exotoxin encoded by beta-prophase. Potent Exotoxin inhibits protein synthesis via ADP-ribosylation of EF-2 Symptoms: pseudomembranous pharyngitis, lymphadenopathy, myocarditis, and arrhythmias Lab diagnosis: gram + rods with Metachromatic (blue and red) granules and + Elek test for toxin Toxoid vaccine prevents diphtheria
28
Listeria monocytogenes: characteristics
Gram + facultative intracellular rod Acquired by ingestion of unpasteurized dairy products and cold deli meats, via trans placenta transmission, or by vaginal transmission during birth Forms "rocket tails" via actin polymerization that allow intracellular movement and cell to cell spread across cell membranes, thereby avoiding AV Characteristic tumbling motility in broth
29
Listeria monocytogenes: Disease
Can cause ammionitis, septicemia, spontaneous abortion in pregnant women Granuloumatosis infantiseptica, neonatal meningitis Meningitis in immunocompromised pts Mild self-limited gastroenteritis in healthy individuals Tx: ampicillin in infants, immunocompromised and elderly as empirical treatment of meningitis
30
Nocardia
Gram +, form long branching filaments resembling fungi Aerobe Acid fast (weak) Found in soil Causes pulmonary infections in immunocompromised (can mimic TB but with - PPD); cutaneous infections after trauma in immunocompetent Treat with sulfonamides (TMP-SMX)
31
Actinomyces
Gram +, form long branching filaments resembling fungi Anaerobe Not acid fast Normal oral, reproductive and GI flora Causes oral/facial abscesses that drain through sinus tracts, forms yellow "sulfur granules" can also cause PID with IUDs Treat with penicillin
32
Mycobacteria
Mycobacterium tuberculosis (TB, often resistant to multiple drugs) -TB symptoms: fever, night sweats, weight loss, cough (non-productive or productive), hemoptysis -Cord factor creates a "serpentine cord" appearance in virulent M.tb strains; inhibits MP maturation and induces release of TNF-alpha. Sulfatides (surface glycolipids) inhibit pahgolysosomal fusion M.avium-intracellular even (causes disseminated, non-TB disease in AIDS; often resistant to multiple drugs) Prophylaxis with Azithromycin when CD4+ count
33
Leprosy (Hansen disease)
Caused by mycobacterium leprae (acid fast bacillus that likes cool temperatures) - infecting skin and superficial nerves (glove and stocking loss of sensation Cannot be grown in vitro. Reservoir in USA: armadillos Treatment: dapsone and rifampin for tuberculoid form, clofazimine is added for lepromatous form
34
Hansen disease: Lepromatous
Presents diffuse lay over the skin with leonin facies, and is communicable. Characterized by low cell-mediated immunity with a humoral Th2 response *Lepromatous form can be Lethal*
35
Hansen disease: Tuberculoid
Limited to a few heypesthetic, hairless skin plaques; characterized by high cell-mediated immunity with a largely Th1-type immune response
36
Lactose fermenting enteric bacteria
Fermentation of lactose --> pink colonies on MacConkey agar E.g. Klebsiella, E.coli, Enterobacter and Serratia (weak fermenter) E.coli produces beta-galactosidase which breaks down lactose into glucose and galactose -EMB agar - lactose fermenters grow as purple/black colonies. E.coli grows with a green sheen
37
Neisseria
Gram - diplococci Metabolize glucose and produce IgA protease so N.gonorrhoeae is often intracellular (within neutrophils) *MeningiGococci ferment Maltose and Glucose, while Gonococci ferment just Glucose*
38
N.gonoccoci
No polysaccharide capsule No maltose metabolized No vaccine due to antigenic variation of pilus proteins Sexually or perinatally transmitted Causes gonorrhea, septic arthritis, neonatal conjunctivitis, pelvic inflammatory disease (PID), and Fitz-Hugh-Curtis syndrome Prevention: Condoms decrease sexual transmission, erythromycin eye ointment prevents neonatal blindness Treatment: ceftriaxone + azythromycin OR doxycycline for possible chlamydial coinfection
39
N.meningococci
Polysaccharide capsule Maltose fermentation Vaccine (type B vaccine not widely available) Transmitted via respiratory and oral secretions Causes meningococcemia with petechiae hemorrhages and gangrene of toes, meningitis, Waterhouse-Friderichsen syndrome (adrenal insufficiency, fever, DIC, shock) Prevention: rifampin, ciprofloxacin, or ceftriaxone prophylaxis in close contacts Treatment: ceftriaxone or penicillin G
40
Haemophilius influenzae
Small gram - (coccobacillary) rod, produces IgA protease. Culture on chocolate agar (factors V - NAD+ - and X - hematin) for growth (can be grown with S.aureus which provides factor V through hemolysis of RBCs) Aerosol transmission Nontypeable strains are the most common cause of mucosal infections (otitis media, conjunctivitis, bronchitis) as well as invasive infections since the vaccine for capsular type b was introduced Causes Epiglotitis (endoscopic "cherry red" or "thumbprint sign" on XR), meningitis, Otitis media, Pneumonia Treatment: amoxicillin +/- clavulante for mucosal infections; ceftriaxone for meningitis, rifampin prophylaxis for close contacts
41
H.influenzae vaccine
Contains type b capsular polysaccharide and PRP (polyribosylribitol phosphate) conjugated to diphtheria toxoid or other protein Give between 2 and 18 months of age Does not cause the flu (influenza virus)
42
Bordetella pertussis
Gram - aerobic coccobacillus VFs: pertussis toxin (disables Gi) and tracheal cytotoxin Causes whooping cough Prevented by Tdap, DTaP vaccines May be mistaken as viral infection due to lymphocytic infiltrate from immune response
43
Legionella pneumophila
Gram - rod. Gram stains poorly (use silver stain) Grown on charcoal yeast extract medium with iron and cysteine Detected by presence of Ag in urine Labs may show hyponatremia Aerosol transmission from environmental water source habitat (e.g. Air conditioning systems, hot water tanks) - no person to person Treatment: macrolide or quinolone Ligonnaires' disease and Pontiac fever (mild-flu like symptoms)
44
Legionnaires' disease
``` Severe pneumonia (often unilateral and lobar), fever, GI and CNS symptoms Common in smokers and in chronic lung disease *Think of a French legionnaire (soldier) with his silver helmet, sitting around a campfire (charcoal) with his iron dagger - he is no sissy (cysteine)* ```
45
Pseudomonas aeruginosa
Gram - rod, aerobic, motile, non-lactose fermenting, oxidase + Produces pyocyanin (blue-green pigment) Has a grape-like odor Produces exotoxin (fever, shock), exotoxin A (inactivates EF-2), phospholipase C (degrades cell membranes), and pyocyanin (generates ROS) Mucoid polysaccharide capsule may contribute to chronic pneumonia in cystic fibrosis pts due to biofilm formation Frequently found in water --> hot tub folliculitis
46
Pseudomonas aeruginosa: Infections
``` *PSEUDOMONAS* Pneumonia, Pyocyanin Sepsis Ecthyma gangrenosum - rapidly progressive, necrotic cutaneous lesion, cause by Pseudomonas bacteremia. Typically seen in immunocompromised pts UTIs Diabetes, Drug use Osteomyelitis (e.g. Puncture wounds) Mucoid polysaccharide capsule Otitis Externa (swimmers ear) Nosocomial infections (catheters, equipment exotoxin A Skin infections (hot tub folliculitis) ```
47
Pseudomonas aeruginosa: Treatments
*CAMPFIRE* drugs Carbapenems Aminoglycosides Monobactams Polyhymnia (e.g. Polymyxin B, Colistin) Fluoroquinolones (e.g. Ciprofloxacin and levofloxacin) ThIRd- and fourth generation cephalosporins (ceftazidime, cefepime) Extended-spectrum penicillins (piperacillin, ticarcillin)
48
E.coli
Gram - rod VFs: fimbriae (cystitis and pyelonephritis - P-pili); K capsule (pneumonia, neonatal meningitis); LPS endotoxin (septic shock)
49
EIEC
Toxin & MOA: Microbe invades intestinal mucosa and causes necrosis and inflammation Presentation: Invasive; dysentery. Clinical: manifestations similar to Shigella
50
ETEC
Toxin & MOA: Produces heat-labile and heat stable enteroToxins. No inflammation or invasion Presentation: Traveler's diarrhea (water)
51
EPEC
Toxin & MOA: No toxin produced. Adheres to apical surface, flattens villi, prevents absorption Presentation: diarrhea, usually in children (*Pediatrics*)
52
EHEC
Toxin & MOA: O157:H7 is most common serotype in US. Often transmitted via undercooked meat, raw leafy vegetables -Shiga-like toxin causes hemolytic-uremic syndrome (HUS): triad of anemia, thrombocytopenia, acute renal failure due to microthrombi forming on damaged endothelium --> mechanical hemolysis (schistocytes), platelet consumption, decreased renal blood flow Presentation: dysentery (toxin alone causes necrosis and inflammation) Does not ferment sorbitol (distinguishes from other strains of E.coli)
53
Klebsiella
Gram - rod. Intestinal flora that causes lobar pneumonia in alcoholics and diabetics when aspirated Very mucoid colonies caused by abundant polysaccharide capsules Dark red "currant jelly" sputum (blood/mucus) Also cause of nosocomial UTIs *4 As of klebsiellA: Aspiration pneumonia, Abscess in lungs & liver, Alcoholics, di-A-betes*
54
Campylobacter jejuni
Gram -, comma or S shaped (with polar flagella), oxidase +, grows at 42 degrees C Major cause of bloody diarrhea, esp in children Fecal-oral transmission through person to person contact or via ingestion of undercooked contaminated poultry or meat, unpasteurized milk. Contact with infected animals (dogs, cats, pigs) is also a risk factor Common antecedent to Guillain-Barré syndrome and reactive arthritis
55
Salmonella typhi
Gram - rods, non-lactose fermenters, oxidase -, and can invade the GI tract via M cells of Peyer's patches Reservoirs: humans only Spread: disseminate hematogenously H2S production: YES Flagella: Yes (salmon swim) VFs: Endotoxin, Vi capsule Infectious dose: high - large inoculum required because organism inactivated by gastric acids Effect of antibiotics on fecal excretion: prolongs duration Immune response: primarily monocytes GI manifestations: constipation followed by diarrhea Vaccine: Oral vaccine (live attenuated S.typhi), IM vaccine (Vi capsular polysaccharide) Unique properties: causes typhoid fever (rose spots on abdomen, constipation, abdominal pain, fever); treat with ceftriaxone or fluoroquinolone; carrier state with gallbladder colonization
56
Salmonella app. (Except S.typhi)
Gram - rod, non-lactose fermenters, oxidase -, and can invade the GI tract via M cells of Peyer patches Reservoir: humans and animals Spread: disseminate hematogenously H2S production: Yes Flagella: Yes (salmon swim) VFs: Endotoxin Infectious dose: high Effect of antibiotics on fecal excretion: prolongs duration Immune response: PMNs in disseminated disease GI manifestations: diarrhea (possibly bloody) Vaccine: none Unique properties: poultry, eggs, pets, and turtles are common sources; antibiotics not indicated; gastroenteritis is usually caused by non-typhoidal Salmonella
57
Shigella
Gram - rod, non-lactose fermenting, oxidase -, invades GI tract via M cells in Peyer patches Reservoirs: humans only Spread: cell to cell; no hematogenous spread H2S production: No Flagella: No VFs: endotoxin, Shiga toxin (enterotoxin) Infectious dose: low - very small inoculum required, resistant to gastric acids Effect of Antibiotics on fecal excretion: shortens duration Immune response: primarily PMN infiltration GI manifestations: bloody diarrhea (bacillary dysentery) Vaccine: none Unique properties: *Four F's: Fingers, Flies, Flood, Feces*, in order of decreasing severity (less toxin produced), S.dysenteriae, S.flexneri, S.boydii, S.sonnei; invasion is the key to pathogenicity - organisms that produce little toxin can cause disease due to invasion
58
Vibrio cholerae
Gram -, flagellated, comma shaped, oxidase +, grows in alkaline media Endemic to developing countries Produces profuse rice-water diarrhea via enterotoxin that permanently activates Gs --> increased cAMP Sensitive to stomach acid (acid labile); requires large inoculum (high ID) unless host has decreased gastric acidity. Prompt oral rehydration is necessary
59
Yersinia enterocolitica
Gram - rod, usually transmitted from pet feces (eg puppies), contaminated milk or pork. Cause acute diarrhea or pseudoappendicitis (right lower abdominal pain due to messenger if adenitis and/or ileitis)
60
Helicobacter pylori
Curved, terminally flagellated, gram - rod that is triple + (catalase, oxidase and urease +) - can use urea breath test or fecal Ag test for diagnosis Urease produces ammonia, creating an alkaline environment, which helps H.pylori survive in acidic mucosa Colonizes mainly the Antrum of the stomach; causes gastritis and peptic ulcers (esp duodenal) Risk factor for peptic ulcer disease, gastric adenocarcinoma, MALT lymphoma Treatment: triple therapy = Amoxicillin (metronidazole if penicillin allergy) + Clarithromycin + PPI
61
Spirochetes
Spiral shaped bacterial with axial filaments Includes borrelia (big size), Leptospira and Treponema. Only Borrelia can be visualized using aniline dyes (Wright or Giemsa stain) in light microscopy due to size Treponema is visualized by dark-field microscopy or direct fluorescent Ab (DFA) microscopy
62
Leptospira interrogans
Spirochete found in water contaminated with animal urine, causes leptospirosis Flu-like symptoms, myalgia (classically calves), jaundice, photophobia with conjunctival suffusion (erythema without exudate) - prevalent among surfers and in tropics (eg Hawaii
63
Weil disease
Icterohemorrhagic leptospirosis - severe form with jaundice and azotemia from liver and kidney dysfunction, fever, hemorrhage, anemia
64
Lyme disease
Borrelia burgodorferi (transmitted by the Ixodes deer tick - vector for Anaplasma spp. And Protozoa Babesia) Natural reservoir is the mouse. Mice are important to the tick life cycle Common in NE USA Stage 1: early localized - erythema migrans (target symbol), flu-like symptoms Stage 2: early disseminated - secondary lesions, carditis, AV block, facial nerve (Bell palsy), migratory myalgias/transient arthritis Stage 3: late disseminated - encephalopathies, chronic arthritis
65
Primary syphilis
Treponema pallidum Localized disease presenting with painless chancre If available use dark-field microscopy to visualize treponema in fluid from chancre VDRL + (80%) of the time
66
Secondary syphilis
Treponema pallidum Disseminated disease with constitutional symptoms, maculopapular rash (including palms and soles), condylomata lata (smooth, moist, painless, wart-like white lesions on genitals), lymphadenopathy, patch hairs loss, also confirmable with dark-field microscopy. Serologic testing: VDRL/RPR (nonspecific), confirm diagnosis with specific test (FTA-ABS) *Secondary syphilis = Systemic. Latent syphilis (+ serology without symptoms) may follow*
67
Tertiary Syphilis
Treponema pallidum Gummas (chronic granulomas), aortitis (vasa vasorum destruction), neurosyphilis (tabes dorsalis, general paresis), Argyll Robertson pupil (constriction with accommodation but is not reactive to light) Signs: broad-based ataxia, + Romberg, Charcot joint, stroke without HTN For neurosyphilis: test spinal fluid with VDR1, FTA-ABS, PCR
68
Congenital syphilis
Presents with facial abnormalities such as rhagades (linear scars at angle of mouth, snuffles (nasal discharge), saddle nose, notched (Hutchinson) tweet, mulberry molars, and short maxilla; saber shins; CN VIII deafness To prevent, treat mother early in pregnancy; as placental transmission typically occurs after first trimester
69
VDRL false positives
VDRL detects nonspecific Ab that reacts with beef cardio lipid Inexpensive, widely available test for syphilis, quantitative, sensitive but not specific Viral infections (eg EBV, hepatitis) Drugs Rheumatic fever Lupus and Leprosy
70
Jarisch-Herxheimer reaction
Flu-like syndrome (fever, chills, HA, myalgia) after antibiotics are started; due to killed bacteria (usually spirochetes) releasing toxins
71
Zoonotic bacteria: anaplasma spp.
Disease: Anaplasmosis | Transmission/source: Ixodes ticks (live on deer and mice)
72
Zoonotic bacteria: Bartonella spp.
Disease: Cat scratch disease, bacillary angiomatosis | Transmission/source: cat scratch
73
Zoonotic bacteria: Borrelia burgodorferi
Disease: Lyme disease | Transmission/source: Ixodes ticks (live on deer and mice)
74
Zoonotic bacteria: Borrelia recurrentis
Disease: relapsing fever | Transmission/source: Louse (recurrent due to variable surface Ag)
75
Zoonotic bacteria: Brucella spp.
Disease: Brucellosis/undulant fever | Transmission/source: Unpasteurized dairy
76
Zoonotic bacteria: Campylobacter
Disease: bloody diarrhea | Transmission/source: feces from infected pets/animals; contaminated meats/foods/hands
77
Zoonotic bacteria: Chlamydophila psittaci
Disease: Psittacosis | Transmission/source: parrots and other birds
78
Zoonotic bacteria: Coxiella burnetii
Disease: Q fever | Transmission/source: aerosols of cattle/sheep amniotic fluid
79
Zoonotic bacteria: Ehrlichia chaffeensis
Disease: Ehrlichiosis | Transmission/source: Ambylomma (lone star tick)
80
Zoonotic bacteria: Francisella tularensis
Disease: Tularemia | Transmission/source: ticks, rabbits, deer flies
81
Zoonotic bacteria: Leptospira spp.
Disease: leptospirosis | Transmission/source: animal urine in water; recreational water use
82
Zoonotic bacteria: Mycobacterium laprae
Disease: leprosy | Transmission/source: humans with lepromatous leprosy; armadillos (rare)
83
Zoonotic bacteria: Pasteurella multocida
Disease: cellulitis, osteomyelitis | Transmission/source: animal bites, cats, dogs
84
Zoonotic bacteria: Rickettsia prowazekii
Disease: epidemic typhus | Transmission/source: human to human via human body louse
85
Zoonotic bacteria: rickettsia rickettsii
Disease: Rocky Mountain spotted fever | Transmission/source: dermacentor (dog tick)
86
Zoonotic bacteria: Rickettsia typhi
Disease: Endemic typhus | Transmission/source: fleas
87
Zoonotic bacteria: Samonella spp. (Except S.typhi)
Disease: diarrhea (which may be bloody), vomiting, fever, abdominal cramps Transmission/source: reptiles and poultry
88
Gardnerella vaginalis
A pleomorphic, gram variable rod involved in bacterial vaginosis Presents as gray vaginal discharge with a fishy smell; nonpainful (vs. vaginitis) Associated with sexual activity, but not sexually transmitted Characterized by overgrowth of certain anaerobic bacteria in vagina Clue cells (vaginal epithelial cells covered with gardnerella) have stipples appearance along outer margin Treatment: metronidazole or clindamycin Amine whiff test - mixing discharge with 10% KOH enhances fishy odor
89
Rocky Mountain spotted fever
Rickettsia rickettsii (tick vector) Occurs in south Atlantic states (esp NC) Rash typically starts at wrists and ankles and spreads to trunk, palms and soles Classic triad: HA, fever, rash (vasculitis)
90
Typhus
R.typhi - endemic (fleas); R.prowazekii epidemic (human body louse) Rash starts centrally and spreads out sparing palms and soles *rickettsii on the wRist, Typhi on the Trunk*
91
Ehrlichiosis
Ehrlichia, vector is tick | Monocytes with morulae (mulberry-like inclusions) in cytoplasm
92
Anaplasmosis
Anaplasma (tick vector) Granulocytes with morulae in cytoplasm *MEGA berry - Monocytes=Ehrlichiosis; Granulocytes=Anaplasmosis*
93
Q fever
Coxiella burnetii: no arthropod vector Spores inhaled as aerosols from cattle/sheep amniotic fluid Presents as pneumonia Most common cause of culture - endocarditis *Q is for Queer because it has no rash or vector and its causative organism can survive outside in its endospore form*
94
Chalmydiae
Chlamydiae cannot make their own ATP. They are obligate intracellular organisms that cause mucosal infections -Elementary body (small, dense) is "Enfectious" and Enters cell via Endocytosis; transforms into reticulate body -Reticulate body Replicates in cell by fission; Reorganizes into elementary bodies Treatment: Azithromycin (favored because of one time treatment) or Doxycylcine Lab diagnosis: cytoplasmic inclusions seen on Giemsa or fluorescent Ab-stained smear
95
Chlamydiae: types
The chlamydial cell wall lacks Classic peptidoglycan (due to reduced muramic acid) rendering beta lactam antibiotic less effective Chlamydia trachomatis: reactive arthritis (Reiter syndrome), follicular conjunctivitis, nongonococcal urethritis and PID Chlamydophila pneumoniae and chlamydophila psittaci: atypical pneumonia (transmitted by aerosol) -psittaci: has an avian reservoir (parrot causes atypical pneumonia)
96
Chlamydia trachomatis serotypes: A,B,C
Chronic infection, blindness due to follicular conjunctivitis in Africa *Africa, Blindness, Chronic infection*
97
Chlamydia trachomatis serotypes: D-K
Urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough) with eosinophilia, neonatal conjunctivitis
98
Chlamydia trachomatis serotypes: Types L1, L2, L3
Lymphogranuloma venereum Small painless ulcers on genitals --> swollen painful inguinal lymph nodes that ulcerate (buboes). Treat with doxycycline
99
Mycoplasma pneumoniae
Classic cause of atypical "walking" pneumonia (insidious onset, HA, nonproductive cough, patchy or diffuse interstitial infiltrate, more common in pts >30 y/o, common in military recruits and prison) X-RAYS looks worse than pt. high hitter of cold agglutinins (IgM) which can agglutinate or lose RBCs Grown on Eaton agar Tx: macrolides, doxycycline, or fluoroquiniolone (penicillin ineffective since it has no cell wall on gram stain - pleomorphic) Bacterial membrane contains sterols for stability
100
Gram + cocci antibiotic tests: Staphylococci
Novobiocin - Saprophyticus is resistant; Epidermidis is Sensitive *on the office's "Staph" retreat, there was NO StRESs*

Microbiology (8 decks)

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