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43 Cards in this Set
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Bacillus anthracis (G+)
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Spore forming, G+ rod, aerobic
Common in livestock (cattle, horses, sheep) First bacteria proven to cause disease 2001 bioterrorism attack Not spread human-human Disease from contact with infected herbivores or indirectly via their products 1. Cutaneous anthrax Handling infected material 95% cases 2-3 day incubation Initial skin papule (small, hard raised area developing into thick, dry, black necrotic tissue (in few days) 20% untreated cases progress to fatal septicemia (meningitis) 2. Intestinal anthrax Eating infected meat Same as cutaneous, but on intestinal mucosa 60% fatal (untreated) 3. Pulmonary anthrax Inhaling spore-laden dust Spores – macrophage – lymph system – germination - systemic Nearly 100% fatal (untreated) For both intestinal and pulmonary, symptoms usually mild at first (low fever, malaise, GI problems). Followed by sudden onset of high fever, disorientation, cyanosis (blue discoloration of skin due to loss of oxygen), shortness of breath and coma/death within few hours Virulence Capsule (prevents phagocytosis) Toxin: organ destruction esp spleen Penicillin very effective |
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B. Cereus (G+)
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B. cereus – known mainly for food poisoning (2-5%)
Diarrheal 8-16 hours after consumption (spore germinating in body) Or Nausea and vomiting 1-5 hours after consumption (toxin in food) Common in rice (cooked – stored at room temp – spore germinates and releases toxin – ingested toxin) May be associated with abscesses, wound infections, burn infections, ear infections, endocarditis, meningitis – all esp in immunocompromised Variety of foods |
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C. Botulinum (G+)
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G+ rod anaerobic, spore forming
Food poisoning (canned foods, sensitive to high acid or high sugar, heating) Preformed toxin Incubation typically 18-36 hours Early GI problems (nausea, vomiting, abdominal pain) – toxin enters blood – attacks peripheral nerves – Flaccid musle paralysis (blocks acetylcholine release) – blurred vision, dilated pupils, slurred speech, dry mouth, overall weakness – death due to respiratory failure Treat with stomach lavage and enemas, antitoxin 15% fatal Wound botulism (rare) Contamination of wound incubation days-weeks No GI distress Infant botulism (2-6 month old) Germination of spores in GI tract (undeveloped) Raw honey is the most frequent cause Constipation – lethargic – drooling – loss of head control, flaccid, respiratory arrest 4-15% cases of sudden infant death Antibiotics/antitoxin Medical use Migraine headaches Involuntary contraction of eye muscles Excessive sweating Neuromuscular disorders Cosmetic Lasts about 6 weeks |
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C. Tetani (G+)
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Common soil organism
Enters through wound, secretes toxin causes muscle spasms Cramping and twitching of muscles around wound – sweating – pain around wound and neck/jaw(Lockjaw) – portions of body become rigid (muscle contraction) –pulmonary/cardiac failure 40-90% fatal if untreated 1 million cases/yr world (a leading cause of death in developing countries) Vaccine available (treatment as well), penicillin Boost every 10 years |
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C. Dificile (G+)
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Normal flora in 3% adults
Severe infection of colon (often after antibiotic therapy) Nosocomial 13% patients in two weeks 50% patients in 4 weeks Symptoms vary (mild diarrhea to severe abdominal pain with fever and weakness due to toxin) 5-10% patients have bloody diarrhea Distinctive foul stool odor May have pseudomembranous colitis (white/gray patches on colon mucosa filled with leukocytes and mucus) Can be lethal Detection by bacterium/toxin in stool (ELISA) Symptoms often resolve after use of antibiotic (1-14 days) Can use vancomycin to treat Supplements of lactobacillus |
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C. Perfringens (G+)
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Clostridium perfringens
Food poisoning Third most common food borne illness (usually meat) Toxin reasonably heat resistant Incubation 8-16 hours, lasts 24 hours Abdominal pain, diarrhea (not lethal) Most people have antibody to toxin (exposed during life) Gas gangrene 1000 cases/yr US Often fatal Wound – impairs blood supply (lack of oxygen) – bacterial growth – fever and pain at site – spread and necrosis of tissue – muscle discoloration (purple mottling) and foul smelling due to anaerobic fermentation (gas bubbles form) Incubation 1-6 days May cause death within hours after incubation period Penicillin and often removal of infected tissues |
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L. Monocytogenes (G+)
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G+ rod
Listeriosis 2500 cases/yr US Eating contaminated food Soft cheeses, pates, raw milk, uncooked or meat stored for long time in fridge Primarily a problem in pregnant women, newborns and immunocompromised Usually asymptomatic in all others Mild flu initially (fever, muscle aches) – Meningitis (stiff neck, headache, confusion, loss of balance) (Pregnant women – mild symptoms, but to fetus – abortion, stillbirth) Present in raw contaminated food Can grow at low temps (in refrigerator) Virulence factors: Secretes toxin (invasion) to penetrate epithelial lining - can replicate intracellularly in macrophages after phagocytosis Toxin (listerolysin) – escape phagolysosome inside macrophage Produce catalase (to block phagocytic digestive activity) Produce Act A (form actin inside infected cell pushing bacteria into a new cell) Ampicillin, vanocomycin FDA approved bacteriophage treatment |
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Corynebacterium diphtheriae (G+)
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Corynebacterium diphtheriae
G+ rod, grouped into “Chinese letter” shapes Toxin released Infects nasopharynx – sore throat, malaise, fever, swelling of neck (Bull neck) – difficult breathing/swallowing Thick gray membrane (pseudomembrane) often forms in upper resp tract – can obstruct breathing Spread by droplets, secretions and direct contact (highly contagious) Can become severe/life threatening – loss of motor function and congestive heart failure Human-human only Vaccine available To toxin (not bacteria), 97% effective Prevaccine: 200,000cases/yr, 15,000 deaths US 5 cases since 2000 Treatment Vaccine or penicillin |
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Staphylococcus Aureus (G+)
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G+ cocci, grape-like clusters
Catalase positive (Strep – catalase negative) Coagulase positive (most other Staph is negative) Growth on high salt Beta hemolysis Entry: wounds or nasal/mucosal 25% pop carrriers *Superficial skin lesions and deep infections *Common cause of food poisoning (abrupt/violet onset Severe nausea, vomiting, diarrhea 1-2 days) *Pneumonia, deep abscesses, endocarditis, meningitis, osteomyelitis (infection of bone marrow) Often associated with indwelling devices (joint prosthesis, heart valves) Virulence factors Proteins for attachment Factors to block phagocytosis Capsule Protein A - to bind IgG Toxins Alpha toxin – septic shock Decreased oxygen delivery, vasodilation Leukocidin Destroy leukocytes Toxic shock syndrome toxin (TSST) Superantigen (stimulate dramatic T-cell response) 1980s – some tampons allowed rapid growth of S. aureus Enterotoxin Diarrhea and vomiting (food poisoning) Common nosocomial and environmental Many antibiotic resistant MRSA – methicillin resistant and multiple resistance 80,000 nosocomial infections/yr 20,000 deaths, ½ nosocomial - worse than AIDS = 17,000 deaths/ yr US Treatment: vancomycin |
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Staphylococcus epidermidis (G+)
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Usually apathogenic
Can form biofilm (catheter problems and indwelling devices) |
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Staphylococcus saprophyticus (G+)
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UTIs
Esp in females 17-27 years old Burning urinations, urge to urinate often |
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Streptococcus Pyogenes (G+)
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G+ chains
Catalase negative (all streps) 5-15% humans have as normal flora Pharyngitis (strep throat) or Tonsillitis Sore and red throat, pain on swallowing, high fever, headache, nausea, vomiting, malaise Impetigo (skin infections) Pimple-like lesions surrounded by reddened skin. Lesions fill with pus, then break down over 4–6 days and form a thick, honey-colored crust. Scarlet fever “strep throat” with rash on upper body, White coating on the surface of the tongue. The tongue itself looks like a strawberry because the normal bumps on the tongue look bigger Pyrogenic exotoxin – causes rash Invasive diseases (10,000 cases/year US, 1,000 deaths) Necrotizing fasciitis Deep infection of subcutaneous tissue Extensive destruction of muscle and fat tissue Multi-organ failure (50% fatal) Superantigen – tissue damage Severe pain and swelling, often rapidly increasing, fever, redness at wound site 25% fatal Streptococcal toxic shock syndrome (STSS) rapid drop in blood pressure and organs Fever, dizziness, Abrupt onset of severe pain, often in an arm or leg, confusion, A flat red rash over large areas of the body 35% fatal Other: Rheumatic fever (autoimmune disease) Chronic disease of heart and valves No bacteria in heart, but follows repeated attacks of strep throat Apparently similar bacterial antigen to self Virulence Capsule M-protein (attachment to mucous membrane, block complement) Toxins Streptolysins (kill leukocytes) Hyaluronidase (Digest connective tissue) Streptokinase (decrease clotting) Superantigens Usually treated with penicillin or clindamycin |
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Streptococcus Pneumoniae (G+)
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20-40% humans have as normal flora
Most common cause of community acquired pneumonia (0.5 million/yr US) Pneumonia progresses vary rapidly with a sudden onset of high fever. Infection can become invasive (bloody sputum/cough)- meningitis Most common cause of sinusitis and conjunctivitis (after childhood) - 7 million/yr US Increasing cause of meningitis (3000/yr US) Capsule important Toxin: Autolysin – lysis of own cells which are no longer dividing (stationary phase) – role to release bacterial components and cause increased human cell death (immune response and more bacterial toxins) 100,000 cases/year US pneumonia (3300 meningitis) Penicillin resistant Vaccine available (since 2000) Esp for meningitis |
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Streptococcus Mutans (G+)
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Streptococcus mutans (viridins group)
Problem in dental work Dental plaque and caries (due to lactic acid production) Can lead to transient bacterimia and heart disease |
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Enterococcus faecalis (group D) (G+)
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98% of enterococcal infections – Diverticulitis (inflammation of Lg intestine, Abdominal pain, constipation, nausea)
Normal GI flora Nosocomial infections - VRE (vancomycin resistance enterococcus) Major cause of endocarditis Also urinary tract, wound infections (high fever, sweating, dilated pupils), meningitis |
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Streptococcus agalactiae (group B) G+
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Neonatal disease (usually during birth)
Pneumonia or meningitis fever, vomiting, poor feeding, and irritability High mortality Penicillin (tetracycline resistant) |
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Bordetella pertussis G-
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Whooping cough
Acute respiratory, severe coughing episode Complications: bronchial pneumonia, acute encephalopathy (rare) Killed 5000-10000/yr US before vaccine (now less than 100) G- coccobacilli Virulence Pertussis toxin Attachment to human cilia (block cilia movement) Leads to increase in mucous secretions Adenylate cyclase toxin Inhibits phagocytic cell digestion (oxidative response) Filamentous hemagglutinin Attachment to human cilia Hemolysin Lyse RBC – obtain iron and nutrients Symptoms Initially runny nose, sneezing, mild cough, and low-grade fever - severe coughing, pneumonia -characteristic ‘whoop’ sound when inhaling Transmission by droplets (person-person) Can only colonize ciliated epithelial cells of respiratory mucosa Bacteremia does not occur Most infectious during early phase but remain infectious for 5 weeks (entire infection) Common childhood disease before vaccine Incubation 1-2 weeks Vaccine Diptheria, tetanus, pertussis (killed vaccine) – 85% US vaccinated (20% mild side effects, 0.1% convulsions) Treatment: erythromycin 2010: 10,000 cases in CA, 2012: 1,500 cases in WA |
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Chlamydia Trachomatis G-
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G-indeterminate cocci (hard to stain, structure G-)
C. trachomatis – - conjunctivitis Most common preventable cause of blindness in world (15% cases, just below cataracts) Spread by touching eye or birth canal - Genital infection Common STD (4 million cases/yr US) – most frequenty reported STD ½ men, ¾ women asymptomatic “Silent epidemic” -Women: pelvic inflammatory disease (infection of uterus, fallopian tubes or ovaries) - infertility Urethritis: Vaginal discharge (milky white/yellow), painful urination -Men: epididymitis (inflammation of coiled tube on back of testis); urethritis (swelling of the urethra) – penis discharge (typically white), painful urination 5X more likely to become infected with HIV Obligate INTRACELLULAR Cannot replicate on own (needs ATP from cell) Infects epithelial cells 1-3 week incubation period Virulence factor Hemagglutinin – attachment to cells Tissue damage due to cell mediated immune response Worldwide (prevalence in Africa and Asia) Antigen test available for detection Treatment Tetracycline (penicillin resistant) C. pneumoniae – atypical pneumonia By inhalation Typically mild |
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E. Coli G-
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G- rod
Common normal flora Virulent strains possess novel genetic elements (ie, plasmids) - noninflammatory diarrhea (watery) - inflammatory diarrhea (with blood, mucous, leukocytes) Transmission fecal-oral Pili allows colonization of ilium Infection common in poor sanitation, traveling to developing countries (“travelers diarrhea) Meat, milk. Water. veg Disease most serious in infants GROUPS: Enterotoxigenic (ETEC) Watery diarrhea, nausea, no-low fever Travelers diarrhea Toxin to damage mucosal cells, secretion of water and electrolytes (LT and ST toxins – shiga-like) Lasts 24-72 hours Non invasive (do not enter cells) Enteroinvasive (EIEC) Dysentary (with blood and mucous), fever Secrete invasive factors Identical symptoms to shigellosis Invade host cells (have adhesion protein) Enteropathogenic (EPEC) Profuse watery diarrhea, fever (occasional bloody) Common in newborn nurseries and nosocomial Unknown toxin Moderately invasive Enterohemorrhagic (EHEC) O157:H7 – serologic group Bloody diarrhea, NO fever, abdominal pain Mainly food borne Shiga-like toxin (A-B subunits) Can cause kidney failure Toxin causes intense immune response Moderately invasive 73,000 cases/yr; 61 deaths/yr 2011: Germany 3,800 cases, 45 deaths (from bean sprouts) Uropathogenic E. coli (UPEC) Causes 90% of urinary tract infections in normal individuals Colonize in urethra and into bladder Women 14X more likely due to shorter urethra and proximity of anus to urethra Treatment: amoxicillin Phage – approved Jan 2007 (US) to be used on meat for human consumption Called Vero toxin |
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Salmonella Enteritidis G-
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Gram – rod
Non-typhoid Gastroenteritis (diarrhea, abdominal cramps, fever) Worldwide Animals are main reservoir (turtles, fowl) Food borne usually (rare person-person) 2 million cases/yr US Salmonellosis 6-48 hour incubation after food intake Nausea, vomiting diarrhea, abdominal pain, headache, fever Lasts 2-7 days Food: 41% turkeys positive 50% chickens 21% eggs Jalapenos, peanut butter, cantelopes |
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Salmonella typhi G-
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Salmonella typhi G- Rod
Typhoid fever (Enteric fever) Person-person (via fecal oral contamination) No significant animal reservoir Carriers can be asymptomatic (“Typhoid mary”) 3% people asymptomatic may last weeks-months Incubation 10-14 days (may be preceded by gasteroenteritis) Sudden fever, anorexia, headache, myalgia (muscle pain), constipation Can be fatal Vaccine available (partially effective) 25 million cases/yr worldwide (500,000 deaths) 1% fatal if treated, 25% fatal if untreated Ciprofloxacin Cystic fibrosis patients immune (need CFTR for entry) Virulence due primarily to adherance Pathogenesis dependent on 1. ability to invade and replicate inside cells 2. LPS layer ***After ingestion, colonize ileum – invade epithelium cells – reticuloendothelial space – can infect deeper tissues of the spleen, liver, and the bone marrow |
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Shigella dysenteriae G-
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Shigellosis – abdominal pain, bloody, mucoid diarrhea
Abdominal tenderness, fever, vomiting, dehydration G- rod Fecal – oral Endemic in poor sanitation areas 50% of bloody diarrhea in small children due to Shigella 448,000 cases/yr Ampicillin, trimethoprim, ciprofloxacin Incubation 24-48 hours Mild – watery diarrhea Severe – dysentery Lasts 7 days Very similar to enteroinvasive E. coli (EIEC) Invades colon epithelium (unique- most bacteria in small intestine/ileum)– and invade subepithelial space If phagocytosed by macrophage – block degradation All lead to massive inflammation and cell death Toxin – leads to fluid accumulation Shiga-toxin (A-B toxin: A=active portion, B=binding portion) |
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Yersinia Pestis G-
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G- Bubonic plague
Transmitted by bite of infected rat flea (rat pathogen) Swollen blackened lymph nodes develop (Buboes) - septicemia and hemorrhagic pneumonia and death - Visible skin darkening Up to 90% mortality if untreated (pneumonia) Pneumonic plague Person-person (droplets) Occurs during epidemic 100% mortality Can die within 24 hours after symptoms Diagnose via bacteria in sputum Gram – coccobacilli Responsible for death of 1/3 population during Middle Ages (1300s) (25 million deaths) Produces two antiphagocytic proteins Only at 37oC F1 – blocks phagocytosis V&W – blocks lysosome Streptomycin, gentamycin (only few antibiotic resistance) |
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Yersinia enterocolitica G-
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G-
Y. enterocolitica Relatively uncommon, Severe diarrhea with abdominal pain Raw or undercooked pork products Deer/cattle pathogen (contaminated water) |
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Haemophilus Influenza G-
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Acute bacteria meningitis
Until vaccine, most common cause of meningitis in children G- coccobacilli Normal flora: 75% pop carriers Colonize nasopharynx – penetrate epithelium – bacteremia - meningitis Headache, stiff neck, epiglottitis (swelling of epiglottis (throat) to the point of choking) Infections of the blood, joints, bones, and covering of the heart Pneumonia (thought originally to be cause of flu infections) Spread via direct contact, secretions, aerosol Diagnosis via bacteria in blood or cerebrospinal fluid (growth, antigen test of PCR) *Requires hemin (factor X) and NAD+ (factor V) for growth NAD+ from blood cells Hemin from lysed blood cells (use Chocolate agar for growth – lysed RBCs in media) *Capsule needed for virulence No known exotoxins IgA protease Ampicillin or cephalosporin (increasing resistance to Amp) Treated: 10% fatal Vaccine: polysaccharide only (Hib vaccine – type b) Prevaccine: 20,000 cases/yr US Postvaccine: 100 cases/yr |
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Heliobacter pylori G-
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Associated with stomach inflammation
Peptic ulcer disease Gastric carcinoma Acute infection: vomiting, upper GI pain G- curved rod, flagella to penetrate mucous lining Sheltered from gastric acidity Only known organism known to thrive in stomach environ. “drills” into mucous layer of gut and attaches to cells Does not invade tissue Produces urease (which degrades urea from stomach producing Ammonia and CO2) - ammonia toxic to cells and leads to epithelium damage Ammonia also buffers acidity to help bacteria survive Possibly infectious (poor sanitation areas – 90% infected) Fecal-oral Normally 30% pop infected (70% assymtomatic) Serological tests are now available (antibodies in serum) Treatment: omeprazole (proton pump inhibitor) + amoxicillin, and clarithromycin for 10 days; bismuth subsalicylate (neutralize acid) + metronidazole, and tetracycline (BMT) for 14 days |
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Campylobacter Jejuni G-
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Campylobacter jejuni
G- spiral rod Most common cause of human diarrhea (3-14% of all cases, worldwide 4 million/yr) Esp. in children under 2 years Fever, malaise, abdominal pain Can lead to relapsing ulcerative colitis (sores in colon, usually more short term) Incubation 2-4 days Replication in intestines ***Common in animal feces (esp birds) Self limiting (1 week) Relapsing: 10-20% cases Present in water, milk, poultry, meat (contaminated from animal feces) Treatment: erythromycin or ciprofloxacin Link to Guillain-Barre’ Syndrome Autoimmune toward peripheral nerves (ascending paralysis) Related to infection (possible mycoplasma, cytomegalovirus, Epstein-Barr virus, Varicella-Zoster virus, 1976 swine flu vaccine) Molecular mimicry |
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Legionella Pneumophilia G-
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Acute pneumonia
Rarely endocarditis Rarely flu-like illness called Pontiac fever Mild illness, self limiting (fever, muscle aches, sore throat, Cough, runny nose – upper resp, no pneumonia) G- rod Reside in drinking water and moist surfaces – “aerosol transmission” (via A/C system, cooling towers) – can invade amoeba as reservoir which protects from environment/chlorination Legionairres disease 1976 outbreak at American Legion conference in Philadelphia 221 treated, 34 deaths A/C system No person-person High fever, chills, dry cough, headache, confusion – nausea, vomiting, pneumonia After infection, engulfed by alveolar macrophage – but is intracellular parasite and multiplies inside macrophage (blocks phagocytic digestion) - release – infect other cells ***NOT obligate intracellular parasite Often nosocomial 10,000 cases / yr US Detect by antiserum to microbe Erythromycin |
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Mycobacterium Tuberculosis G-
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Obligate aerobe
Acid fast (waxy layer) Divides 20 hours – several days Can survive for weeks in dry environment G- curved rod 1/3 pop has been exposed 14.6 million active cases worldwide (rate currently dropping due to increased testing) Chronic productive BLOODY cough, low fever, night sweats, weight loss, fatigue Isolates may take 4-6 weeks to grow Airborne transmission – enter alveoli – engulfed by alveolar macrophage – replicate inside macrophage - form primary lesion – spread via lymph – reinfect lungs Accumulation of bacteria form inflammatory focus forming \granulomatous lesion (called tubercle). Can even become calcified 5-10% develop active disease (most asymptomatic, 90%) Persistant infection may reactivate due to immune deterioration Diagnosis via skin test and clinical manifiestations and chest radiograph Treatment: 6-9 months of rifampin (block dna dep RNA pol) and isoniazid (block cell wall) MDR-TB (resistant to these – 2% of isolates of TB) Elderly, malnourished, alcoholics, and poor (300x greater in homeless) In immunosuppressed – can infect CNS – meningitis and systemic |
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Mycobacterium Leprae G-
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M. leprae
Leprosy (infection of skin, peripheral nerves and mucous membranes) Leading to lesion, hypopigmentation, loss of sensation Permanent damage to skin, nerves, limbs and eyes Inflammation leads to nerve damage – numbness, paralysis, lesions, deformity Also called Hansens disease Transmission requires prolonged contact of individual infected 10 million cases worldwide (Asia and Africa) |
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Mycoplasma Pneumoniae G-
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Mycoplasma pneumoniae
Smallest known bacterium No cell wall (Gram indeterminate) Lacks ability to make nucleotides Obligate parasite Invades upper and lower resp tract Cough, fever, headache for weeks Convalescence is slow 15-50% of all pneumonias (“walking pneumonia) Mycoplasma sp. : Linked with several chronic diseases, including chronic fatigue syndrome, fibromyalgia syndrome, gulf war syndrome, and rheumatoid arthritis (36-50% of all patients carry Mycoplasma) Unknown if primary cause or secondary infection Person-person May have asymptomatic reservoirs Droplet spread Incubation 2-3 weeks Binds to and infects epithelial cells (membrane fusion?) Tetracycline and macrolides (no cell wall antibiotics) |
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Neisseria Gonorrhoeae G-
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Neisseria gonorrhoeae
G- cocci, “The Clap” Human only known host Sexual contact Bind epithelial cells – penetrate cells– multiply on the basement membrane Needs pili for attachment 30-60% asymptomatic Urethra fluid discharge (often green or yellow), difficulty urinating most common symptoms If untreated, can become bacteremia fever, chills, hand/feet arthritis, skin lesions, pelvic pain Incubation 2-5 days Transmission frequency: 35-60% per sexual time 700,000 cases/yr US Cephalosporin, doxycycline |
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N. meningitidis G-
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Skin lesions (purple) and Acute bacterial meningitis
Lesions key to diagnosis Distributed over body Neck stiffness, headache, fever, purple rash (progress rapidly) *Typically in young adults (not children) Spread by inhalation - attach to nasopharyngeal mucosa – cross mucosal barrier – bloodstream – CNS Present in normal flora (5-30% people) 10% fatal with treatment Vaccine available (meningococcal) – strains A/C (50% cases) Penicillin • Neisseria is difficult to grow: • Chocolate agar (lysed RBC in media) and CO2 environment. • Thayer-Martin agar: Chocolate agar with vancomycin to kill Gram + and Polymyxin E to kill most other Gram - |
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Moraxella catarrhalis (previously Neisseria catarrhalis) G-
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Gram – diplococcus
Common infections of middle ear (otitis media) and sinusitis. 3-4 million cases per year in US. 70% of children will get infected Elderly, smokers and chronic obstructive pulmonary disease (COPD) : Lower respiratory and pneumonia (Up to 45% mortality) Immunocompromized: pneumonia, endocarditis, septicemia, and meningitis Emerging human pathogen (increase dramatically over past 20 years) Normal flora in most people Resistant to many B-lactams. Quinolones and tetracycline useful. |
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Rickettsia rickettsii:
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G- rod
Obligate intracellular parasite Bite of ticks, mites (zoonotic) Rocky mountain spotted fever Severe human disease – 25% mortality unless treated, 4% treated Mainly eastern US (Maryland to Georgia, Oklahoma, Missouri, Ohio, Tenn, Ark, Tex) Bite – bloodstream – endothelium of blood vessels and smooth muscle – invade cells – damage Damage to blood vessels leads to typical rash Fever, rash (on extremities first), headache, nausea, muscle aches. cutaneous necrosis at bite site Difficult to diagnose since cannot culture (need cell) Tetracycline, chloramphenicol |
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R. typhi
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Endemic typhus
Feces in lice and fleas – scratch –rub into wound Headache, high fever, cough, muscle pain, chills, Chest rash spreading to extremities |
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Treponema pallidum G-
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syphilis
genital tract lesion – developing into disseminated lesions 1/3 people: cardiovascular and neurological problems Pregnancy: birth defects or death G- helical/spirochete Lack LPS Also very few outer proteins (not very antigenic) Humans only reservoir Primary stage Incubation of 10-90 days Skin lesion on genitalia Enlarged lymph nodes Last 2-6 weeks Secondary stage 1-6 month post infection (asymptomatic in between) Mild fever, malaise, rash on trunk and extremities, Mucous patches on genitals and mouth Most infectious stage This stage can reoccur many times Tertiary stage 1-10+ year post infection Any tissue may be affected 80% fatalities due to cardiovascular Neurological (meningitis) Joint disease 10 bacteria can cause disease Penicillin (not yet resistant) For 10-14 days, IV |
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Borrelia burgdorferi G-
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Via deer tick and black-legged tick
In certain areas, 20-60% ticks carriers Rodents are major reservoir (white footed mouse) Deer important for tick life cycle (not carriers of Borrelia) Lyme disease Expanding ring-shaped red rash (in 70% patients) G- spirochete Bite – bloodstream - systemic Incubation period 1 week Generalized infection – relapsing fever, headache, muscle pain (days, weeks, months or years) *May also have arthritis and carditis (inflammation of heart) *Persistent neurological and arthritic infections may last years (muscle pain, malaise - relapsing) – meningitis, mild encephalitis (leading to memory loss), Bell’s Palsy (loss of muscle tone in face) *Possible link to lymphoma (lymphatic cell cancer) - CHANGES antigen (allows relapsing) 30,000 cases/yr US (one of fastest growing diseases) 17,000 cases/yr in 2000 10,000 cases/yr in 1990 Often hard to diagnose (level of spirochete in blood very low), serological test typical Early: tetracycline or penicillin Late: ceftrixone (B-lactam) - (2 g/day, 4 weeks) |
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Pseudomonas aeruginosa G-
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Opportunistic
Nosocomial (burns, cancer, cystic fibrosis, post-operative infection in radial keratotomy surgery patients) 50% fatality Common in cystic fibrosis patients Infections: endocarditis, pneumonia, UTI, wounds “Blue-pus” in infections and sputum G- rod Many toxins Protease (tissue destruction) Hemolysin (kill macrophage) Leukocidin (block host defense) Pigments (anti-bacterial) Toxin A (block host defenses) Resistant to many antibiotics Gentamycin, carbenicillin |
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Klebsiella pneumoniae G-
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G- rod, ubiquitous, normal flora
Large capsule Common cause of pneumonia up to 50% mortality Esp. nosocomial, link to ALCOHOLISM, diabetes (weakened immune). Gangrene in diabetics. Common in alcoholics, immune compromised “Currant jelly” like sputum (bloody color and thick) Can cause urinary tract infection |
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Vibrio cholerae G-
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G- curved rod
Diarrhea (numorous, voluminous watery stools) And vomiting Incubation 6-48 hours Initial stool: excess of 1Liter Followed by several liters within hours Lasts 2-7 days Massive fluid and electrolyte loss 50% fatal without treatment Infects only the small intestine Toxin Increases cAMP levels – massive fluid and electrolyte efflux Human only host Fecal oral contamination Most recent epidemic in 1992 (India and Bangladesh) Treatment Replace fluids and electrolytes Tetracycline |
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Pasteurella pneumotropica G-
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Gram – coccobacilli
Opportunistic (found in commercial and research rodents) mice, hamsters, rabbits, cats, guinea pigs, dogs normal flora – oral, respiratory, genital, GI Often spread via bite of animal to human Respiratory infection (Nasal discharge, congestion, conjunctivitis) and abscesses (can be chronic requiring surgery) |
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Brucella melitensis G-
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Gram – coccobacillus
Zoonotic (various mammals – marine, horses, etc) No obvious virulence factors, lives within macrophage In US, 100-200 cases/year Spread via infected meat and unpasteurized milk products - typical infected food or inhalation via occupational exposure - no human to human Influenza-like with fever reaching 38 to 40oC. Limb and back pains severe, sweating and fatigue Chronic: chronic fatigue syndrome, depression, and arthritis Can rarely lead to systemic infection in CNS (5% cases) chronic headaches, nausea, vomiting, visual deterioration Abortions/infertility in livestock |
