Staph Aureus Sketchy

Staph Aureus (Grape-granule golden) - Grows on blood agar, yellow appearance - Gram positive take up crystal violet stain (appear violet) - Catalase positive (catalase converts hydrogen peroxide to water) - Coagulase (enzyme for fibrinogen to fibrin) positive - Beta hemolytic - Mannitol salt agar can ferment mannitol (turns it yellow) - Main Virulence Factor - Protein A prevents opsonization and phagocytosis - Colonizes opening of nose - Causes pneumonia (patchy infiltrate) - Icosahedron shape - Post viral bacterial pneumonia - Most common cause of septic arthritis - Cellulitis, impetigo, furuncle boils, abscesses - Acute bacterial endocarditis - IV drug user, R sided tricuspid valve - Scalded skin syndrome - Toxic shock syndrome (foreign packing in too long) - Super antigen non specific binding of MHC II sand T cell receptors,s cytokine storm - Staph food poisoning, rapid onset form preformed toxin (more vomiting than diarrhea) - meats or cream based foods left out for too long. - MRSA - altered penicillin binding proteins PBP treat with vancomycin, nafsolin - Naf for staf Staph Epidermidis (Catalase positive, urease positive, coagulase negative) - Infects artificial joints and implanted hardware (prosthetic joints, indwelling catheters) - Most common cause of endocarditis affecting artificial heart valves - Sticks to metals biofilms (polysaccharides) coating protects from immune cells - Resistant to many antibiotics - Treat with endocarditis with vancomycin - Have to replace the prosthetic joints - Staph Epi is novobiocin sensitive Staph Saprophyticus (Catalase positive, urease positive, coagulase negative) - Novobiocin resistant - Common cause of UTI in sexually active females Strep Pyogenes (Group A) - Long chains or pairs - Group A Strep is encapsulated (hyaluronic acid) major virulence factor is M protein that prevents opsonization. - We produce hyaluronic acid in our connective tissue - Beta hemolytic - Infections: impetigo “honey crusted” skin infection (also caused by Staph Aureus) - - - - Pharyngitis: Strep Throat Cellulitis and erysipelas: superficial cellulitis with well demarcated borders Toxin streptococcus pyogenes exotoxin (SPE): scarlet fever, strawberry tongue, pharyngitis, widespread rash that spares the face Toxin Shock LIke Syndrome: behaves as a superantigen. Flesh eating bacteria, necrotizing fasciitis, spreads rapidly, true surgical emergency Three types of SPE: - SpeA - superantigen (TSLS) - SpeB - protease (necrotizing fasciitis) - SpeC - supernatigen (TSLS) Rheumatic Fever and PSGN Rheumatic Fever: M protein antigenic protein in cell wall main virulence factor responsible for rheumatic fever, interferes with opsonization so it is antiphagocytic (molecular mimicry) mimics myosin in heart and causes our own antibodies to attack our heart and mitral valves (Type II) JONEs Criteria: Joints (polyarthritis), Heart problems (valvular damage, myocarditis, pericarditis, subcutaneous nodules (elbows and knees), Erythema marginatum (thick red borders), Sydenhams korea rapid movements Post-Strep Glomerulonephritis: Type III Dark brown cola colored urine facial swelling puffiness from edema 2 week after onset of strep infection or impetigo Strep throat treatment can prevent RF but not PSGN Tx: penicillin for strep infection Virulence Factors: Streptolysin O lyse red blood cells and beta hemolytics, we generate ASO antibodies to prevent this Streptokinase - puts a phosphate on something converts plasminogen to plasmin (fibolynitic) DNase - depolymerize DNA Group A Strep (Pyogenes): Bacitracin Sensitive Group B Strep: Bacitracin Resistant ASO O titer can tell use if we had a recent strep infection Streptococcus Agalactiae (Group B Strep) - Infections in newborns - Hippurate positive (hydrolysis sodium hippurate) - Polysaccharide Capsule main virulence factor - CAMP test positive when GBS is plated with Staph Aureus it has an increasing zone of hemolysis - Beta hemolytic (narrow zone of complete hemolysis) - Bacitracin resistant - Causes meningitis in neonates, sepsis , and pneumoniae - Passes through vaginal canal of mother during delivery - Culture at 35 weeks of pregnancy - If the mother is colonized with Group B strep, you give mom intrapartum penicillin Strep Pneumoniae - Both are alpha hemolytic - Partial hemolysis shas a green hue (oxidation of hemoglobin) - Encapsulated Strep Pneumo - Polysaccharide capsule main virulence factor - Optochin sensitive - Lancet-shaped diplococci - Bile soluble - #1 cause of community acquired pneumonia (lower lobar pneumonia) rust colored sputum - MOPS (meningitis, otitis media, pneumonia, sinusitis) - IgA protease, colonizes and invades our mucosa - Sickle cell disease susceptible - Two firsts line: Erythromycin (macrolide) or 3rd gen cephalosporin (ceftriaxone) - Children vaccine is conjugated to a protein - Adult is T cell independent response only IgM - By conjugating it to a protein, it generates a more robust T cell response to produce IgG Strep Viridans - Alpha hemolytic - Optochin resistance - Bile insoluble - Strep mutans dental caries - Singuidanse damaged heart valves (mitral) Enterococcus - Intestinal tract gram positive coccus - E Faecalis: more common - E Faecium: less often superbug more serious problems - Grow on mediums of more the 6.5 % Na.CL - Bile resistant - UTIs, Endocarditis, Biliary tree infections - Vancomycin resistant enterococcus - Tx: Linezolid (IV antibiotic) Tigecycline Gram Positive Bacillus Bacillus Anthracis - Black eschar surrounding erythematous ring (ring of fire) - Large gram + rods in chains - Encapsulated, capsules are unique - Capsule is made of protein (poly D-glutamate) - Obligate aerobe (needs O2 to survive) - 2001 Anthrax scare, ability to be weaponized. Sent in an envelope - Can forms spores and hibernates in state highly resistant to temperatures and chemicals - Spore forming - Edema factor: (adenylate cyclase increase cAMP, fluid goes into ECF causes edema inhibits host defenses - Lethal factor: exotoxin acts as protease that cleaves MAP-kinase, tissue necrosis - Pulmonary Anthrax → hemorrhagic mediastinitis widened mediastinum - Fluoroquinolones or doxycycline Bacillus Cereus - Anaerobic and spore forming - Food poisoning - Vomiting and diarrhea after eating reheated fried rice Clostridium Tetani - Gram + - Obligate anaerobe (cannot survive in the presence of oxygen) - Often found in soil, inside of a puncture wound closed off to air, rusty nails or barbed wire - Construction worker or child near construction zone - Neuromuscular symptoms: psastic paralysis, muscle contractions leading to rigidity (vs flaccid paralysis in botulism) - Lockjaw symptoms - Extension and arching of back due to spasms Opisthotonus - Travels retrograde through motor axons to the spinal cord - Acts as a protease, cleaves SNARE protein inhibits exocytosis of NT into the synapse - GABA and glycine release inhibited leading to spasticity - Rensaw: gaba and glycine release from renshaw cells is inhibited - Tetanus vaccine: toxoid vaccine conjugated to a protein, antibody response to toxin not to the organism Clostridium Botulinum - Improper canning of food, allows for survival of spores, heat stable toxins - Multiple family members developing neuro symptoms - Obligate anaerobe gas mask, struggling to keep bodies upright, flaccid paralysis - Descending paralysis, diplopia, ptosis - Only affects peripheral nervous system not CNS - Cleaves SNARE protein Attacks motor neurons that release AcH, when inhibited leads to flaccid paralysis Toxin is a protease that cleaves SNARE proteins In babies, flaccid paralysis, “floppy baby syndrome”, adults only get it in an anaerobic environment. Normal bacterial flora outcompete it. Babies lack this flora to protect themselves, commonly found in honey. Infants should avoid honey Adults = preformed toxin Babies = spores Clostridium Difficile - Spore forming - Nosocomial diarrhea (while hospitalized) - Thorough wash with soap and water - Antibiotics wipe out normal flora - Clindamycin commonly cause C.Diff infections - Improper handwashing is a common way it is transmitted - Exotoxin A and Exotoxin B - Apple workstation: binds to brush border of intestine, inflammation cell death watery diarrhea. Exotoxin A targets the brush border causing diarrhea. - Exotoxin B is for black licorice - Disrupts cytoskeleton integrity by disrupting actin, yellowish gray exudate that covers colonic mucosa. Pseudomembranous colitis. Actin depolymerization. - Tx: oral vancomycin or fidaxomicin. Metronidazole Clostridium Perfringens - Motorcycle accidents and deep penetrating wounds from military combat - Large amount of flesh exposed to dirt or dust - Spore former, found in dirt and soil - Obligate anaerobe - Two diseases - Soft tissue necrosis (gangrene): clostridial myonecrosis, gas is produced under infected tissue, crepitus, crackling sound on palpation, organism consumed carbohydrates involves an alpha toxin (lecithinase cleaves lecithin and damages cell membrane by damage lipoproteins) - When red cell membranes are affected hemolysis occurs in vivo and vitro - Double zone of hemolysis on blood agar - Tx: IV penicillin G - Spores germinate in gut and then create the toxin inside, late onset of symptoms (10-12 hours after food poisoning symptoms) - Watery diarrhea, transient usually doesn't require antibiotic treatment Corynebacterium Diphtheria (Non-spore forming gram positive rod) - Gram +, club shaped in a Y or V formation - Contain metachromatic granules stained red with aniline dye - A active subunit B iss binding subunit - ADP ribosylation of EF-2 which inhibits ribosome function and inhibition of protein synthesis → cell death → pseudomembrane (grayish white membrane) - Found in throat and tonsils, transmitted by respiratory droplets - Can spread to larynx and trachea → airway obstruction - Lymphadenopathy → Bulls neck thickening of neck - Bloodstream → affect heart and nervous system - Cardiac → Arrhythmias and heart block - Local paralysis begin in posterior pharynx and lead to other CN deficits - Diphtheria affects myelin of nerve fibers - Lab Dx: culture or toxin assay, swab membrane and plate them on tellurite and loeffler's media - Toxic or noon toxic → Elek test, if it binds there is reaction, it is toxic - Often immigrants, not vaccinated child - Toxoid vaccine, inactivated exotoxin bound to protein → powerful IgG response - Administer anti-toxoid Listeria Monocytogenes - Gram positive bacillus - Narrow zone of hemolysis (beta hemolytic) - Tumbling motility - When intracellular, it rapidly polymerizes actin along the cell wall, jump from cell to cell - Actin rockets intracellularly - Catalase positive - Able to survive and multiply in near freezing temperatures - Contaminate food in refrigerator (milk, soft cheese) - Early in pregnancy early termination - Pregnant women discouraged from eating soft cheeses - Meningitis 3rd most common cause following Group B strep and E.coli - Meningitis in adults over 60 → vancomycin and ceftriaxone and ampicillin to cover listeria - Tx: for listeria → AMPICILLIN Actinomyces Israeli (gram positive branching rods) - gram + filamentosus (branching) rod - Obligate anaerobe - Normal flora of oral cavity - Infection → jaw trauma - Take advantage of tissue injury allowing it spread over head and neck - Invades surrounding structures cervical actinomyces infection - Slow coarse - non tender lump on jaw, abscess, sinus tracts drain infection site through skin, thick yellow pus (yellow sulfur granules) Penicillin G Nocardia Species - Obligate Aerobe, acid fast (weak) - Found in soil - Gram positive filamentous branching rod (similar to actinomyces) - Mycolic acid → light acid fast staining carbol fuchsin stain - Catalase positive → chronic granulomatous disease (CGD) increased risk of infection of catalase positive organism - Urease positive - Affects immunocompromised patients impaired cell mediated immunity (HIV, transplant patients, patients on glucocorticoids - More men>women - Main sites of infection: pulmonary, CNS, cutaneous - Pulmonary: pneumonia with lung abscess formation cavitary lesions in the lungs - Once in lungs t can disseminate it has a high affinity for neural tissue → brain abscesses - Cutaneous infections after trauma in immunocompetent (gardening, carpentry) → indurated lesions and inflammatory reaction - Tx: sulfonamides Gram Negative Cocci Overview Neisserias Species - Gram negative diplococci - Oxidase positive - Chocolate Agar, cannot grow in blood agar - Heated blood agar → chocolate agar - Growth on VPN (vancomycin, polymyxin and nystatin) - Thayer Martin aka VPN agar - Complement deficiency C5-C9, unable to form Membrane attack complex (MAC) leading to increased infections - Virulence Factors: Pilus (allow for attachment, also has frequent genetic rearrangement, antigenic variation, difficult for immune system to target it) - Produced IgA protease cleaves IgA at hinge point survival of mucosal surfaces - Both ferment glucose Neisseria Meningitidis - Spread by respiratory droplet - College kid in close quarters - Only meningitidis ferments maltose in addition to glucose - - Colonizes the nasopharynx first, transmitted by sneezing coughing kissing, sharing drinks Polysaccharide capsule → virulence factor inhibits phagocytosis Given before college, vaccine contains the capsule Type B capsule is not included in the vaccine Most caused by Type B strain Sickle cell and asplenic patients are at higher risk because it is encapsulated Establishes infection by spreading hematogenously, massive inflammatory response generated by lipooligosaccharides (LOs) proteins enveloped version of LPs, outgrows surface of bacteria and blebs off, the blebs cause the inflammatory response LOS envelope proteins on fire (inflammatory response) → Permeability of capillaries → leakage of fluid into extravascular space → hypovolemia Petechial rash → thrombocytopenia → can progress to DIC (bleeding gums, oozing at injection sites) Capillary leakage can lead to hypovolemia and shock → peripheral vasoconstriction increases and leads to renal insufficiency (often fatal) Waterhouse friderichsen sen syndrome, hemorrhage of adrenals 3rd gen cephalosporin → penetrate blood brian barrier ceftriaxone Close contacts → give prophylaxis (rifampin) Neisseria Gonorrhoeae - STI: genitalia of men and women - Men: urethritis → prostatitis, orchitis - Women: pelvic inflammatory disease (PID) → scarring → infertility → ectopic pregnancy - White purulent discharge (thicker than chlamydia) - Gram negative diplococci facultative intracellular PMNs - Not encapsulated - Can spread into peritoneal → adhesions → violin string adhesions - Fitx Hugh Curtis syndrome → spread of PID to peritoneum - Polyarthritis → knee asymmetric - Purulent synovial fluid that doesn't gram stain because infection in intracellular - Expecting Mother pass it onto baby during delivery - Purulent conjunctivitis first 5 days N. Gonorrhoeae - Chlamydia → delayed (1 week after birth) - Tx: Cefriaxone, assume coinfection with Chlamydia Enterobacter - Gram negative bacilli - Lactose fermenter (pink on MacConkey agar) - Multidrug resistance - Motile - Causes pneumonia and UTIs Serratia - Gram negative bacilli - Lactose fermenter (pink on MacConkey agar) Motile - Produces red pigment when cultured - Causes pneumonia and UTIs Klebsiella - Gram negative bacilli - Lactose fermenter (pink on MacConkey agar) - Polysaccharide Capsule - Non-motile - Causes pneumonia and UTIs - Three As: - Alcoholics, Abscesses, Aspiration - Cough up: “currant jelly sputum” - Cavitary lesion on right lobe, can often look like TB - Urease positive + Proteus Mirabilis - Gram negative facultative anaerobe - Demonstrates swarming motility - Staghorn calculi kidney stones take in renal pelvis - Urease positive → ability to form staghorn produces ammonia and Co2 from urea creating an alkaline environment, struvite stones. Cause pain and kidney damage also cause for recurrent infections - Cause UTIs - Fishy odor Susceptible to sulfonamides Salmonella Typhi Gallbladder of chronic carriers Typhoid Mary Rose spots red macules on abdomen #1 cause of osteomyelitis in patients with sickle cell disease Diarrhea resembles pea soup Treated with antibiotics (fluoroquinolone i.ee. cipro) Live attenuated vaccine Salmonella Enteritidis Eating undercooked chicken (main reservoir) Inflammatory diarrhea Motile, H2S positive, Encapsulated, Acid labile (easily degraded in stomach) Need a high dose to cause infection All enteric bacteria that are motile are H2S positive grow black colonies on Hektoen agar plate Passes through the stomach, small intestine, then invades sylpmhartics taken up by macrophages, and then into blood. Facultative intracellular specific in macrophages Virulence factor: Type 3 secretion system detects eukaryotic cells protein helps with infectivity Shigella Sonnei Uncomplicated watery diarrhea in developed countries Shigella Dysenteriae Infection can precipitate HUS Prodromal diarrhea, acute renal failure Glomerular damage activates platelets but drops platelet count, lyse red blood cells, schistocytes Children < 10 y/o Shiga Toxin: binds to 60s subunit of ribosomes and inhibits translation Type III secretion system (inflammatory cytokines) Escehrichia Coli Gram negative enteric gastroenteritis → bloody diarrhea Green colonies on hektoen agar Immotile Acid-stable (fewer organisms to cause infection) Peyer's patches M cells (sample things in lumen and bring back antigens on other side) Shigella induces M cells tto phagocytosis them and they escape from phagolysosome once in cytoplasm they use actin cytoskeleton to create a tail to propel itself Use of actin filaments invasion of M cells Facultative intracellular Damages tissue and releases cytokines Fecal blood and leukocytes (inflammatory diarrhea) Lactose fermenting (pink on MacConkey agar) Encapsulated K antigen: present on capsule used for serotyping Eosin methylene blue: metallic green sheen Catalase positive Fimbriae (pili): necessary for bug to cause UTIs #1 cause of UTIs Gram negative sepsis: LPS endotoxin in outer cell membrane Neonatal meningitis, only if it has the K antigen Enterohemorrhagic E. Coli (EHEC) Eating undercooked meat (hamburgers) Bloody diarrhea Unique only E. coli that does not ferment sorbitol Same toxin Shiga, Shiga-like toxin: binds to 60s subunit Can cause HUS in children <10 O157:H7 serotype outbreaks Enterotoxigenic E. Coli (ETEC) Traveler’s diarrhea Water sources Mexico Heat Labile increases cAMP (similar to cholera toxin) Heat Stable increases cGMP Yersinia Enterocolitica Gram negative coccobacillus bipolar staining (on two ends ) looks like a safety pin Encapsulated Transmitted through puppy species Kids playing with dogs, can also be transmitted through contaminated milk products (also listeria) Resistant to cold temperatures Causes bloody diarrhea Fever leukocytosis and abscess, intestinal perforation Main: mimic appendicitis (pseudoappendicitis) Yersinia Pestis Cause of the black plague (Bubonic plague) Killed 25 million people Humans are incidental host Main reservoir is rodents (prairie dogs now) Fleas that bite them and then bite Swollen tender lymph noodles (buboes) DIC and cutaneous hemorrhage caused by endotoxin necrosis of digits and or appendages Exotoxins Yersinia associated outer proteins Cause macrophage and neutrophil dysfunction Organism replicates Type III secretion mechanism Treatment: aminoglycosides (streptomycin and tetracycline) Killed vaccine used to prevent CampyloBacter Jejuni Gastroenteritis and Diarrhea Guillain-Barre Syndrome Prefers to grow in heat Lives sin intestinal tract of other animals (poultry reservoir) Fecal oral transmission Slaughter process Curved gram negative rod Oxidase positive Bacteremia Invasive Reactive arthritis (writer syndrome) camp B infection Autoimmune response demyelination of PNS → ascending paralysis Bloody Diarrhea Vibrio Cholerae Profuse watery diarrhea (high volume) Rice water diarrhea Fecal - Oral via poor sanitation Cholera does not invade the mucosa Uses fimbria to attach itself and then releases cholera toxin Increases cAMP Blinds to adenylate cyclase and activates sit (Gs pathway) Endemic to south east asia Genus Vibrio Comma shaped bacteria Tx: water rehydration Grows in Alkaline media (basic environments) Cholera is acid-labile Oxidase positive Vibrio Parahaemolyticus Contaminate seafood especially oysters Vibrio Vulnificus Helicobacter Pylori Pseudomonas Helical shape in antrum in our stomach Gram negative curved (more helical though) Motile (flagellum) Urease positive (ammonia and Co2) reduce acidity of environment Urea breath test: radioisotopes detected means urease positivity Biopsy on endoscopy Oxidase positive 95% of duodenal ulcers H.Pylori Chronic infection increased acid production by reducing somatostatin or increasing gastrin Adenocarcinoma of stomach increased risk Lymphoma of mucosa associated lymphoid tissue (maltoma) if you treat h pylori the maltoma will go away Triple Therapy or Quadruple Therapy Gram negative rod Thrives in aquatic environments (Hot tub folliculitis) Oxidase positive Catalase positive - chronic granulomatous disease Blue-Green pigment when plated Pyocyanin and Pyoverdin may turn wounds blue Fruity grape like odor Obligate aerobe #1 cause of gram negative nosocomial pneumonia Pneumonia in CF patients (resp failure) Mutation in CFTR gene (transporter that regulated Cl ions) Unable to actively pump Cl- ions Osteomyelitis → IV drug users and diabetics (ulcers) Encapsulated Burn patients → Pseudomonas often fatal and unresponsive to antibiotics Indwelling catheters - nosocomial UTIs Skin lesions → Pruritic papular pustular Tx: Antipseudomonal penicillins (piperacillin with tazobactam) (1) Proton Pump Inhibitor (2) Amoxicillin (3) Macrolide (Clarithromycin) Aminoglycosides and fluoroquinolones (UTIs) folliculitis Sepsis → toxin that causes cutaneous necrosis (ecthyma gangrenosum) Otitis Externa (very painful outer ear (swimmers ear) Pseudomonas Toxin (Exotoxin A) → Ribosylated target elongation factor 2 Inhibits protein synthesis and cell death → same as diphtheria exotoxin Bordetella Pertussis War hero after wounded Highly contagious respiratory droplets Attaches to respiratory epithelium using pili Release toxins that cause symptoms Filamentous hemagglutinin (antibodies against it help protect against infection) Pertussis toxin: increases cAMP by ADP-ribosylation of Gi (Toxin inhibits Gi) Inhibits an inhibitor → rise in cAMP Also disables chemokine receptors for lymphocytes, get stuck in bloodstream Massive lymphocytosis Adenylate cyclase toxin: same toxin as edema factor in bacillus anthracis Increase in cAMP Tracheal toxin: peptidoglycan wall of pertussis damage ciliated cells in respiratory epithelium (cleaves long cilia like grass) Symptoms: non specific symptoms first (conjunctival injection lacrimation) Paroxysmal stage: “whooping cough”usually in children intense bout of coughing post tussive emesis Convalescent stage: gradual reduction of symptoms 100 day cough Tx: macrolides treat early Protection: prevent respiratory droplets Two vaccines killed and acellular Killed is no longer available only use the cellular one (purified antigens of bacteria) usually given to children along with diphtheria toxoid and tetanus toxoid DTap Haemophilus Influenzae Gram negative bacteria Coccobacilli Special media: chocolate agar (hematin and NAD+) Factor V: NAD+ nicotinamide Factor X: hematin Aerosol transmission First respiratory track → pneumonia (1) Epiglottitis → inflamed epiglottis, inspiratory stridor, drooling (2) Otitis media Vaccine for type B capsule Increased risk for asplenic patients of sickle cell Polysac of haemophilus capsule conjugated with diphtheria toxoid → strong IgG response Between 2-18 months to vaccinate child Tx: beta lactam antibiotic Meningitis or systemic disease → ceftriaxone Rifampin used for prophylaxis in meningitis in close contacts Legionella Gram negative, oxidase positive but need to use a silver stain to see it better Buffered charcoal yeast extract in presence of cysteine and iron Legionnaires disease: occurs in smokers, atypical pneumonias CXR: patchy infiltrate with consolidation of one lobe Highly variable presentation Clinical presentation: - Associated with hyponatremia (wasting salt) - Neurologic symptoms (confusion headache) - Diarrhea - High fever (greater than 104) Testing: Rapid urine antigen test Tx: macrolides or fluoroquinolones Pontiac Fever: fever and malaise usually self limiting Bartonella Henselae Cat scratch disease, Gram negative Warthin-Starry (special silver stain) Cat scratch fever transmitted with cat scratches Involve regional lymph nodes, painful and large Lymphadenitis at axillary occurs in immunocompetent Bacillary angiomatosis also transmitted through cat bites (immunocompromised patient) Tx: Doxycycline Self-limiting Azithromycin or macrolides Brucella Cattle or farm animals (Gram negative) Cow and pig Direct contact with farm animals vet or rancher Indirect contact via recent consumption of milk or cheese products Ingestion of unpasteurized dairy products Facultative intracellular (can live intracellularly or extracellularly) Prevents phagocytosis Symptoms: fever, chills, anorexia Undulant Fever, Replicate intracellularly, Enlargement of spleen, liver and lymph nodes Osteomyelitis (chronic brucella infection) Tx: tetracyclines (doxycycline) or rifampin as adjunctive for primary treatment Francisella Tularensis Rabbit named francis Main reservoir for francisella (handling rabbits or eating rabbits) Indirect through a tick vector (Dermacentor Tick) Aerosolized (used in bioterrorism) - mandatory to report to CDC Gram negative and looks like a radish (coccobacilli) Facultative intracellular Recovery from infection depends on CMI Bacteria enters at site and develops of painful ulcer Rotting radishes → enter through the ulcer goes into macrophage and travels through the lymph systems to lymph nodes, granulomas with caseation necrosis Regional lymphadenopathy can spread systemically Tx: Streptomycin (aminoglycoside) Pasteurella Multocida Respiratory tract of small animals like cats and dogs Transmission is dog and cat bites Cellulitis may occur within 24 hours → necrotizing fasciitis Osteomyelitis Catalase positive Oxidase positive, Capsule (Virulence Factor) Grows well on 5% sheep's blood agar Demonstrates bipolar staining (at two ends) similar to yersinia Tx: penicillin or beta-lactamase (amoxicillin and clavulanic acid) Mycobacteria Mycobacterium Tuberculosis Acid fast (high conc. Of mycolic acid in cell wall) takes up carbolfuchsin stain Prevent dye from being washed out Lowstein -Jensen agar Obligate Aerobe (like nocardia) Resides in macrophages Serpentine shapes (cord factor) → protect bacteria fromm being destroyed Eliciting granuloma formation increased TNF and inflammatory cytokines to activate more macrophages Bacteria stays walled off Sulfatides (survive inside cells) prevent phagolysosome infusion (sparing them from interaction with enzymes Incompentn 2nd lysosomes) 1..Heald latent infection -- occurs hilar lymph nodes and middle lobes (Ghan complex) 2. Systemic infection - caseating granulomas with central necrosis and langerhans giant cells - Bone liver lymph nodes, multi organ failure → miliary TB 3. Reactivation TB - State of immunosuppression, HIV, cancer - Downregulation of TNF-a release - Affects upper lobes - Cough, night sweats hemoptysis - Cachexia (wasting, weight loss) *before putting patient on a TNF-alpha inhibitor (i.e. infliximab) do a PPD to check for TB* Pott's Disease → spinal deformities, abscess, loss of support, vertebral bodies cracked and damage CNS involvement, meningitis or tuberculosis in the brain Tx: resistant to multiple drugs, period is very lung Combination: (1) RIPE Rifampin Isoniazid Pyrazinamide Ethambutol Prophylaxis: rifampin and isoniazid 9 months Mycobacterium Leprae Thrives in cool temperatures (extremities of the body) Acid fast bacteria (mycolic acid carbol fuchsin stain) Reservoir (armadillo) Leprosy (Hansen’s Disease) Two presentations: Tuberculoid: Th1 response with cell mediated immunity Able to contain bacteria within macrophages Symptoms are mild: well demarcated hairless hypoesthetic skin plaque Lepromin skin test ID injection of antigens to test for immune reaction Positive test means good CMI intact Lepromatous Leprosy: Th2 cells predominant immune response → humoral response High transmission human to human (theorized respiratory droplets) Symmetric neuropathy (stock and glove pattern) Numerous poorly demarcated raised lesions mostly on extensor surfaces Biopsy skin lesions → large amount of bacteria Profound facial deformity (thickening of skin loss of eyelashes, collapses of nose, nodulary ear lobes) Look like a lion Present within a spectrum usually Tx: Multidrug therapy (long time) Th1 (tuberculoid): Dapsone and rifampin for 6 months Th2 (lepromatous): Dapsone and rifampin, add clofazimine (2-5 years) Spirochetes (spiral shaped bacteria) Borrelia Burgdorferi North Eastern US (new hampshire and connecticut) Ixodes scapularis (involved in Lyme Disease, ehrlichiosis, babisiolsis) Larvae feasts in white headed mouse (reservoir) and white tailed deer is host of adult tick, tick is the vector Incidental host Spirochetes do not gram stain Wright stain and Giemsa stain Lyme green Three stage of Borrelia: (1) Erythema chornica migrans (bulls eye rash) - Not painful or pruritic - 1 month after tick bite - Flu like symptoms (2) Heart block caused by myocarditis - Bilateral facial nerve palsy (bell's palsy) (3) Arthritis of large joints (knee), may move from joint to joint migratory polyarthritis - CNS effects: memory difficulty , cognitive slowing, lymphocytic meningitis (encephalopathy) Tx: doxycycline or ceftriaxone (more severe presentations) Leptospira Interrogans Leptospirosis Endemic in tropical regions (highest incidence is in Hawaii) Spirochete small thin and spiral shaped (question marked shape) Commonly found in rodents and dogs, excreted in their urine Transmitted to humans when they swim in the water (water sports) Flu-like symptoms fever intense headaches Conjunctival suffusion Lack of inflammatory exudate (red with no pus) Whale’s Disease: travels through bloodstream multiply in various organs (renal dysfunction and jaundice for liver damage) Hematogenous spread Kidneys: Fever and high creatinine levels and azotemia Liver dysfunction and jaundice Treponema Pallidum STD syphilis Palladium observatory Transmission: sexually transmitted Spirochete (spiral shaped bacteria) may be described as spiral shaped Dark Field microscopy needed for direct visualization of the organism Main screening test: VDRL (treponema) not specific just antibody reactivity to a particular antigen RPR: rapid plasmin reagent Many false positives due to cross reactivity with other antigens (MONO, RF, SLE, LEP, DRG) Confirmatory Test: FT A-b (treponemal test to confirm positive a screening result) Symptoms: Early stages: 1st year (primary secondary and early latent) Primary: painless genitalc chancre a few weeks after inauguration, invading small blood vessels, small areas of necrosis, takes out nerves (painless), Secondary: Macularpapular rash, on hands and soles of feet , condyloma lata (bumps on mucous membranes) Visualizes the spirochete sin condyloma lata with dark field microscopy Late: Tertiary and Late latent Tertiary: Gummas, small growths with firm necrotic center (skin bones organs). Aortitis, ascending thoracic aorta, ascending thoracic aneurysms), tree barking appearance of aorta. Destroys the small blood vessels that supply the thick part of the aorta. Microbe damages small vessels. Weakening of aortic wall and aneurysm formation. Vasa vasorum endarteritis and obliteration Damage to posterior column of spinal cord, ocular effects Neuronal damage, Argyll-Robertson pupils that accommodate but do not react to light Congenital Syphilis: developing countries Hunter has a saber near his shins, anterior bowing of tibia Saddle on pegasus to symbolize a saddle shaped nose Shivering kids (chattering) hutchinson's teeth and mulberry molars (enamel outgrowths) Congenital DEAFNESS, hepatomegaly rhinitis and rash Tx: Penicillin always the answer every stage and everyone (especially with pregnant womens) Allergy → tetracycline Jarisch-Herzhemier reaction: dying spirochetes releasing LPSS increase in cytokines fevers chills headache hours of treatment, good indicator it is working Overview Obligate intracellular bacteria Lack of staining with a gram stain (rickettsia species similarity) Cant create its own ATP Cell wall of chlamydia lack of muramic acid (make up cell wall) Elementary Bodies Reticulate Bodies 1st stage: elementary stage infectious form 2nd stage: inside the cell (clam is split into two) Reticular body → how the bacteria multiply through binary fission → actively dividing form Last stage: release of new bacteria Inclusion bodies seen under microscope Giemsa stain (borrelia species also) NAAT PCR test Tx: no muramic acid (can't use penicillins) Macrolides (azithromycin) Topical macrolides not sufficient for newborn, must give them oral form Tetracyclines doxycycline Coinfection of Chlamydia and Gonorrhea Often come together treat for both Single dose of ceftriaxone for Gonorrhea Chlamydia trachomatis A-C: Blindness → trachoma leading cause of blindness worldwide transmission by hand to eye contact D-K: STI → watery discharge, no symptoms may progress to PID Neonatal conjunctivitis and pneumonia (1-2 weeks after birth) Staccato cough L1-L3: LGV → lymphogranuloma venereum : infection of inguinal nodes lymphatics. Painless genital ulcer but weeks to months later a tender lymphadenopathy with draining lymph nodes Reactive arthritis → maladaptive antibody response cross react and attack the body sacroiliac joint and knee Reiter's syndrome: cant see, can't pee, cant bend my knee Arthritis, uveitis, and urethritis Chlamydophila pneumoniae Atypical pneumonia (walking) More common in elderly than adults Chlamydophila psittaci Transmitted by bird “parrots” → respiratory problems Coxiella Burnetii Q Fever, no rash (vs. rickettsia borrelia that does have rash) Gram negative Obligate intracellular Spore like structure in animal droppings or dirt Transmitted to humans via aerosol transmission Farm animals are reservoir or a vet exposed to placental excretions Also causes hepatitis and pneumonia symptoms Self-limiting and goes away in two weeks Rare → endocarditis ‘ Pasteurizing milk, acellular vaccine given to vets Gardnerella Vaginalis Gram variable rod, stain as gram positive or gram negative gram variable Lactobacilli Bacterial overgrowth that disrupts the normal flora Thin malodorous fish discharge from vagina Fly traps look like aa vulva (grayish-white discharge) pH 4.5 and up infection occurs 10% KOH test Whiff test Microscopic exam Wet mount preparation shows clue cells that are epithelial cells diffusely coated with bacteria Clue cells - epithelial cells coated with clue cells Tx: metronidazole Mycoplasma Pneumoniae Walking pneumoniae No cell wall → cannot appear on gram stain Cholesterol in cell membrane (sterols stabilize cell membrane and allow them to be more flexible) May not appear sick clinically X-ray appears much worse than the parents do physically “patchy infiltrate” Increased incidence in young adults close contact military recruit in close quarters Confirm Dx: IgM molecules that agglutinate erythrocytes in cold temperatures Cold agglutinins only in 50-75% of patients Eaton's Agar Treatment: Macrolides (azithromycin) TORCHES Infection Toxoplasma - transmission: cat feces, raw meat - mother: lymphadenopathy - newborn: blueberry muffin rash, retinitis, hydrocephalus, intracranial calcification Rubella - transmission: respiratory droplets - mother: rash, lymphadenopathy, arthritis - newborn: “cant see, cant hear” cataracts, sensorineural hearing loss, PDA, blueberry muffin rash CMV (herps 5) - transmission: sexual, organ transplant - mother: mononucleosis - newborn: blueberry muffin rash, hearing loss, seizures, petechiae, periventricular calcifications HIV - sexual contact and needle sticks - maternal: aids symptoms - newborn: recurrent infections (SCID), chronic diarrhea HSV-2 - skin contact Herpetic lesions Herpetic lesions encephalitis perioral rash Syphilis Transmission: Sexually Mother: Three stages for mom Newborn: Hydrops fetalis, deafness, short maxilla, rhagades around mouth, hutchinson teeth, saddle nose