micro exam 3 arthropod

Bacillus Anthracis- aerobic, gram positive, spore forming, causes anthrax, fever, chills, headache, malaise, severe breathing and shock


Anthrax transmission- direct contact with endospores


Anthrax treatment- penicillin, ciprofloxacin


Anthrax prevention- avoid contact with infected livestock and animal products


Clostridium tetani- gram positive anaerobic rod, causes tetanus, muscle stiffness in jaw and neck, trismus forms spore


Tetanus and Gas Gangrene transmission- direct contact with spores through wound


Tetanus treatment- tetanus antitoxin, penicillin


Tetanus prevention- immunizing with toxoid vaccine

Clostridium perfringens- causes gas gangrene, foul odor and intense pain and swelling of wound site


Gas gangrene prevention- cleaning wound and debridement 


Leptospira interrogans- causes leptospirosis, acute headache, muscle ache, vomiting and fever chills, 


Leptospirosis- in human, bacteria enters through mucus membranes and skin abrasions, in animals, coloniizes in kidneys  


Leptospirosis transmission- diseased animal urine contaminates food, water, soil -50% occurs in hawaii, 40-100 cases a year


Leptospirosis treatment- penicillin, doxycycline


Inhalation Anthrax-  resembles common cold, respiratory distress, fatal without treatment 


Cutaneous Anthrax- skin most common 95% of infections, itchy bumps developed in vesicle, then painless black ulcer, 20% untreated causes death


Skin cutaneous anthrax symptoms- blackened eschar surrounded by edema, painless, start like insect bite


Anthrax lethality factors- antiphagocytic polysaccharide capsule and secretion of anthrax toxin

Antiphagocytic polysaccharide capsule- prevents cell of immune system from killing bacterium


Secretion of anthrax toxin- cytotoxin to macrophage primarily, Protective Antigen (PA), Edema Factor (EF), Lethal Factor (LF)


Apoptosis- caused by synergistic effects of anthrax


 B Anthracis germination- invades and hiijacks macrophage, destroys macrophage and inhibits cytokine response


LeTx (LT)- lethal toxin induces apoptosis of activates macrophages by destroying MAPK kinases


Trismus- clenched teeth and jaw, “fixed smile”


Opisthotonus- arched back, reduce ventilation, death


Exotoxins of tetanus- tetanospasmin and tetanolysin

Tetanospasmin-  prevents release of glycine, GABA and other neurotransmitters and block muscle relaxation 


Tetanolysin- cytotoxin,causes tissue damage and may contribute to the development of tetanus


Intestinal Anthrax- intense inflammation of GI tract, abdominal pain, vomiting, sever bloody diarrhea, 25-60% death rate 


Lethal dose of tetanus- 130 ng


I mild tetanus- mild  trismus, general spasticity, no respiratory embarrassment, no spasms, no dysphagia


II moderate tetanus- moderate tismus, rigidity, short spasm, mild dysphagia, mod respiratory involvement, res rate  > 30


III severe tetanus- severe trismus, prolonged spasms, respiratory > 40 pulse >120, dysphagia, apnoeic spells


IV very severe tetanus- grade 3 plus severe autonomic disturbances in cardiovascular system


Burkholderia Pseudomallei- gram-negative bacilli, causes Melioidosis


Melioidosis- through contaminated wounds, involeved in vietnam war, “medical time bomb” lies dormant for years fatal 100% if untreated 

Melioidosis chronic- abscess in heart, lung, liver 


Melioidosis acute- pneumonia and septicemia 


Melioidosis treatment- ceftazidime, doxycycline 


Yersinia Pestis- cause plague transmitted through infected flea bite, inhaling infection droplet from animal or person


Yersinia pestis and tularemia treatments- tetracycline and streptomycin


Bubonic plague- sudden onset, fever chills, muscle aches, buboes, mainly from prairie dogs (rodents)


Buboes- swollen lymph nodes


Xenopsylla cheopsis- plague transmitted through rat flea


Septicemia plague- bacteria and toxin in blood

Septicemia plague symptoms- abdominl pain, bleeinging under skin and from mouth nose or rectum, fever diarrhea, low BP, organ failure, shock, gangrene


Gangrene- death of tissue causing blackening of extremities, fingers, toes, nose


Francisella tularensis- tularemia, from tick bites, rabbit skinning and meat, gram negative bipolar staining rods, ulcers from infection though tick bites


Glandular Tularemia - swollen glands from tick bite


Inhalation tularemia- respiratory disease from tick bite


Pneumonic plague- respiratory system headache, lung hemorrhaging and cardiovascular collapse 


Borrelia burgdorferi- lyme disease, spirochate, most common arthropod borne disease


Lyme disease transmission- deer tick bite, ixodes scapularis, ixodes pacificus


Stage 1 lyme disease- Erythema migrans rash at tick bite site, beggins small and has circular expansion up to 15 in, bulls eye rash, no itch


Stage 2 lyme disease- if left untreated disease spreads to nervous system, skin, heart, multiple small EMs, meningitis, muscle pain


Stage 3 lyme disease- chronic arthritis, swelling of large joints including knee, encephalopathy and neuropathy


Lyme disease treatment- amoxicillin or doxycycline, immunization LYMErix 


Borrelia hermsii- spirochate, Relapsing fever, by ticks and lice 


Relapsing fever transmission- reservoir rodent ticks and lice 


Relapsing fever symptoms- fever, chills, headaches, muscle joing pain, nausea, maybe rash, appear withing 2-9 days 

Relapsing fever treatment- found in blood smear with presence of spirochaetes, uses doxycycline antibiotic


Rickettsial Arthropod borne diseases- obligate intracellular parasites, transmitted through ticks, fleas, and lice, treated with doxycycline and chloramphenicol


Rocky mountain spotted fever- begins with rash, fever nausea, emisis lack of appetite, maculopapular rash, petechial rash, abdominal pain


Rash- damage of small blood vessels 


Rickettsia prowazekii- epidemic typhus fatal illness, decimated aztec population in 1500s


Epidemic typhus transmission - body lice, pediculus


Brill-Zinsser Disease- milder epidemic typhus, spread by lice and fleas on flying squirrels

Rickettsia typhi- endemic (murine) typhus in southwest USA, from fleas


Endemic murine typhus symptoms- abdominal pain, diarrhea, backache, extremely high fever, arthragia, nausea, vomiting 


Epidemic typhus symptoms- fever, chills, maculopapular rash withing 5-9 days, photophobia, delirium 

Scrub typhus-Asia and the Pacific is carried by a chigger mite in scrublands, caused by Orientia tsutsugamushi


Rickettsialpox- like chickenpox spread by mites from mice caused by Rickettsia akari


Trench fever- Bartonella (Rochalimaea) quintana;  Vectored by head and body lice