Flashcards in Gram - Bugs Deck (48)
what is one thing all gram - bugs have in common??
-all have a lipopolysaccharid outer membrane of cell wall-endotoxin
What are the medically relevant gram - cocci?
moraxella catarrhalis (resides in respiratory tract, causes tracheobronchitis and pneumonia)
What is the most prevalent human bacterial STI?
Where is a gonorrheal infection found in women and men?
-men: urethra, may extend to prostate and epididymis causing sterility
Gonorrhea, does this spread beyond the urethra and cervix? if so, where?
-yes, may become systemic disease.
--arthritis, endocarditis, meningitis
-gonorrhea neonatorum, eye infection during passage through birth canal, may lead to blindness
-natural reservoir is the human nasopharyngeal mucosa
-transferred via direct contact or droplets
-subclinical/minimal disease sx
-fulminant meningeal sepsis sx
-subclinical: short febrile flu-like sx, cleared spontaneously
-fulminant meningeal sepsis: fever**, severe HA**, vomiting**, neck/back pain, stiffness*, petechial rash*, altered mental status, shock, organ failure.
-fever, HA, vomiting, neck/back pain, skin rash, AMS
Fulminant meningeal sepsis and meningitis may progress to what?
-shock; endotoxin causes capillary leakage, poor vascular tone, intravascular microthrombi, myocardial dysfunction
-DIC; endothelial damage>>> hemorrahges, microthrombi
Meningitis rash, where is it often found on the body?
-pin point rash often on the trunk but sometimes on the hands.
Diagnosis of Fulminant meningeal sepsis and meningitis?
-FMS lesions appear 6-12 hours
-meningitis lesions appear 12-18hrs after onset, no lesions in 20% or pts
FMS: gram stain of skin lesion biopsy specimen
Meningitis: only CSF positive
How do you treat FMS and meningitis?
-always start ABX IMMEDIATELY!! even before other diagnostic procedures.
-use cefotaxime or ceftriaxone plus vanco
-patients in contac... prophylactic abc Rocephin (ceftriaxone)
-cause infections of?
-resistant to which meds?
-cause infection of upper and lower respiratory, middle ear, eye, CNS, joints
-resistant to PCN, SMX/TMP, tetracyclines
-treat w/ FQ, most 2nd, 3rd cephalosporins, macrolides, augmentin
-common inhabitant of?
-frequent contaminant of?
-most common cause of?
-gram - rod w/ single polar flagellum
-common inhabitant of soil and water
-contaminant of ventilators, IV solutions, anesthesia equipment
-most common cause of nosocomial infections
-complications include pneumonia, UTI, abcesses, otitis, corneal disease, endocarditis, meningitis, bronchopneumonia
-treat w/ cephalosporins, aminoglycosides, carbenicillin, polymixin, quinolones, and monobactams.
**Harleys go to is quinolones*
Brucella and Brucellosis
-what are the 2 species
-gram - coccobacilli
-Brucella abortus (cattle)
Brucella suis (pigs)
-sx: malta fever, undulant fever*, bang disease(zoonosis transmitted to humans from infected animals
**fluctuating patter of fever, weeks to a year.
-tx: tetracycline and rifampin or streptomycin
How do you get Brucella species?
-consumption of unpasteurized milk and soft cheeses made from milk of infected animals.
- facultative intracellular coccobacillus
-causese tularemia (zoonotic disease of mammals endemic to norther hemisphere, particularily rabbits)
-transmitted by contact with infected animals, water and dust or bites by vectors.
-Sx: HA, backkache, fever, chills, malaise, weakness
-tx: gentamycin or tetracycline
-causes what disease?
-causes pertussis or whooping cough "100 day cough"
-reservoir is healthy carreiers
-transmitted by direct contact or inhalation of aerosols
-vaccine for this?
Virulence: bind to ciliated respiratory epithelial cells, toxins destroy and dislodge ciliated cells. Loss of ciliary mechanism leads to buildup of mucus and blockage of the airways.
-treat with macrolides....AZITHROMYCIN!
Legionella pneumophilia and Legionellosis
-how did this bug get its name?
-distributed in water, organisms inhaled in aerosolized mist
-pneumonia afflicted 200 American Legion members
-sx: fever, cough, diarrhea, abdomin pain
What are the pathogenic strains of e.coli? What
-enterotoxigenic E.Coli -causes severe diarrhea d/t heat-labile toxin and heat-stable toxin- stimulate secretion and fluid loss
-enteroinvasive e.coli: causes inflammatory disease of large intestine
-enteropathogenic e. coli: linked to wasting from infantile diarrhea
-enterohemorrhagic e.coli: O157:H7 strain, causes hemorrhagic syndrome and kidney damage
What is a coliform count used for?
-indicator of fecal contamination in water
e.coli is a major causes of what?
-SMX/TMP, nitrofurantoin, FQs
Other than e.coli what are some other coliforms? Where are they found in the body? What type of infections do they cause?
-klebsiella pneumoniae-normal inhabitant of respiratory tract, has large capsule, cause of nosocomial pneumonia, meningitis, bacteremia, wound infections and UTIs
-enterobacter: UTI, surgical wounds
-serratia marcescens: produces red pigment, causes pneumonia, burn and wound infections, septicemia, and meningitis
-citrobacter: opportistic UTI and bacteremia
-how do you get this?
-gram - rod, unusual bipolar staining and capsules
-contact with wild animals or infected humans *found in rodents, flea vectors
Pathology of Bubonic plague?
-may progress into what?
bacillus multiplies in flea bite, enters lymph, causes necrosis and swelling called a bubo in groin or axilla.
-septicemic: progression to massive bacterial growth; intravascular coagulation, subcutaneous hemorrhage and purpura-black plague.
-pneumonic: infection localized to lungs, highly contagious; fatal without treatment.
Tx of plague
streptomycin, tetracycline, or chloramphenicol
-what is this?
-how does it present?
-zoonotic genus; normal flora in animals.
-animal bites/scratches cause local abscess that can spread to joints, bones, and lymph nodes
-PCN and tetracycline