GRAM NEGATIVE Flashcards
Infection may result in hemorrhagic colitis progressing to the hemolytic uremic syndrome (HUS)
EHEC (E. coli 0157:H7)
-HUS is characterized by ACUTE RENAL FAILURE, microangiopathic HEMOLYTIC ANEMIA, and THROMBOCYTOPENIA in children
Leading cause of UTI’s
Escherichia coli
-other causes of UTIs include PROTEUS, SERRATIA, KLEBSIELLA, PSEUDOMONAS, and STAPHYLOCOCCUS SAPROPHYTICUS
Causes “Traveler’s diarrhea” and is also a major cause of death in children of developing nations
Escherichia coli
-the enterotoxigenic strain produces a HEAT STABLE and HEAT LABILE TOXIN that causes an EXPLOSIVE WATERY DIARRHEA with cramping, abdominal discomfort, and dehydration
This zoonotic organism can be transmitted by the bite of a deerfly or tick or through handling or consuming rabbit products, which are the reservoir
Francisella tularensis
-infection can result in NECROTIC ULCERS at the site of entry; conjunctiva (OCULOGLANDULAR), mouth (TYPHOIDAL), or lungs (PNEUMONIC TULAREMIA) with disseminated granulomatous lesions of the lung, spleen, and liver
Organism closely associated with chronic gastritis and peptic ulcer disease
Helicobacter pylori
-also associated with an increase in the development of GASTRIC CARCINOMA and MALToma
Formerly a leading cause of infection in children, the incidence of infection has dramatically decreased with introduction of a vaccine
Haemophilus influenzae
-vaccine is composed of the capsular material, POLYRIBITIOL PHOSPHATE [PRP] , conjugated to diphtheria toxin
Major cause of aspiration pneumonia in alcoholics
Klebisella pneumoniae
-organism produces a large antiphagocytic capsule, giving it a MUCOID appearance and producing a thick, bloody, “CURRANT-JELLY” sputum
Paired, kidney bean-shaped diplococci within leukocytes in a urethral discharge
Neisseria gonorrhoeae
-differentiated from N. meningitidis based on its ability to ferment GLUCOSE AND MALTOSE, whereas N. gonorrhoeae ferments GLUCOSE ONLY
Leading cause of septic arthritis
Neisseria gonorrhoeae
-typically presents as MONOARTICULAR ARTHRITIS of the knee, ankle, or wrist after a bout of URETHRITIS
Infection of a neonate passing through an infected birth canal results in ophthalmia neonatorum and purulent conjunctivitis
Neisseria gonorrhoeae
-babies born in the US receive a required administration of tetracycline, erythromycin, or SILVER NITRATE DROPS to prevent this
STD that can lead to PID that the predisposes to ectopic pregnancy
Neisseria gonorrhoeae
-2nd most common NOTIFIABLE DISEASE in the US
Leading cause of meningitis among military recruits and dormitory settings
Neisseria meningitidis
-patients with DEFICIENCIES IN THE COMPLEMENT COMPONENTS C6-9, “THE MEMBRANE ATTACK COMPLEX” are particularly SUSCEPTIBLE TO INFECTION
Septicemia resulting from this organism can result in progressive hypotension, DIC, widespread vascular purpura, and bilateral adrenal hemorrhage
Neisseria meningitidis
-the shock and ADRENOCORTICAL INSUFFICIENCY of WATERHOUSE-FRIDERICHSEN SYNDROME is RAPIDLY FATAL without Abx treatment
Causes a self-limiting enterocolitis associated with the consumption of contaminated eggs and poultry
Salmonella enteritidis
-this HIGHLY MOTILE organism requires a LARGE INFECTIOUS DOSE, which distinguishes it from Shigella spp.
Causes an enteric fever with the development of characteristic “rose spots” on the abdomen
Salmonella typhi
-after recovery, a small percentage of pts may become carriers because the organisms COLONIZE THE GALLBLADDER, a state that may require CHOLECYSTECTOMY
Infection with a small dose of organisms results in dysentery that is only transmitted among humans with no animal reservoir
Shigella dysenteriae
-this cause of a BLOODY, MUCOID, LOW-VOLUME DIARRHEA can result in life-threatening dehydration and acidosis and is often associated with INSANITARY CONDITIONS
Major cause of secretory diarrhea with life-threatening dehydration, particularly in developing nations
Vibrio cholerae
-these COMMA SHAPED rods with a polar flagellum adhere to the intestinal mucosa and elaborate an exotoxin, but never invade
Rodents are the reservoir for this organism, transmitted by the bite of a flea, resulting in the plague
Yersinia pestis
-transmission is also possible between humans in the case of the PNEUMONIC PLAGUE
Infection can result in pustules and enlargement of draining lymph nodes that rupture through the skin to form buboes
Yersinia pestis
-this organism displays BIPOLAR STAINING resulting in a SAFETY PIN APPEARANCE
Transmitted by the bite, scratch, or lick of an infected cat, resulting in low-grade fever and a characteristic enlargement of lymph nodes for several weeks
Bartonella henselae
-this is the causative agent of CAT SCRATCH DISEASE; infection of an immunocompromised pt can result in BACILLARY ANGIOMATOSIS, CRANBERRY-LIKE PUSTULES resembling Kaposi sarcoma
Causes a blood diarrhea and is associated with the consumption of undercooked meat and dairy products
EHEC (E. coli 0157:H7)
-this DYSENTERY-LIKE condition is due to the elaboration of VEROTOXINS similar to Shiga toxin that causes CYTOTOXICITY to the colonic mucosa
Transmitted by contaminated livestock and unpasteurized dairy products, infection results in a fever that rises in the morning and falls at night (Undulant fever)
Brucella spp.
-this GRANULOMATOUS INFECTION invades the RETICULO-ENDOTHELIAL CELLS of the lymph nodes, liver, spleen, and bone marrow
This organism is transmitted through the bite of a domestic dog or cat and can result in an abscess, cellulitis, and osteomyelitis
Pasteurella multocida
-short, encapsulated, bipolar staining organism is part of the NASOPHARYNGEAL FLORA of domestic DOGS and CATS
Infection with this coccobacillus causes epiglottitis, otitis media in children, sinusitis, meningitis, and pneumonia in older pts with chronic respiratory disease
Haemophilus influenzae
-growth in culture of this organism requires FACTOR V [hemin] and FACTOR X[NAD], found in chocolate agar media
A common cause of bloody diarrhea, particularly in children in close contact with puppies and kittens, which serve as reservoirs
Campylobacter jejuni
-these rod-shaped organisms appear as “gull-wing”-shaped colonies with a single flagellum
Predominant organism in the human colon
Bacteroides fragilis
-most often the cause of serious ANAEROBIC infection
Endemic to tropical nations, this sexually transmitted organism results in granulomatous genital ulcers (pseudobuboes) with the potential for autoamputation of genitalia
Calymmatobacterium granulomatis
-diagnosis is based on finding intracellular organisms aggregated as “DONOVANI BODIES”
This organism is a common cause of nosocomial infections; some strains produce a red pigment
Serratia marcescens
-causes pneumonia, bacteremia, endocarditis, and is often MULTIDRUG-RESISTANT
A STD, results in painful necrotizing genital ulcers (Chanchroid)
Haemophilus ducreyi
-infection in the US is rare, most infections occur in the TROPICS; painless ulcer= T. pallidum
Infection can result in folliculitis, swimmers ear, pneumonia, and sepsis with the development of characteristic skin lesions (Ecthyma gangrenosum)
Pseudomonas aeruginosa
-the organism grows well in water, especially in inadequately chlorinated HOT TUBS; culture results in green colonies resulting from pigments PYOVERDIN and PYOCYANIN, with a characteristic FRUITY ODOR
Major cause of pneumonia in burn patients and cystic fibrosis patients
Pseudomonas aeruginosa
-this OBLIGATE AEROBE requires only TRACE ELEMENTS for growth and is a major cause of NOSOCOMIAL infections because it colonizes aspirators, water and ice dispensers, CATHETERS, IV lines, and even dilute disinfectant solutions
Urease-positive organism that causes an alkaline urine predisposing to the formation of urinary calculi
Proteus spp. (P. mirabilis and P. vulgaris)
-these HIGHLY-MOTILE organisms are often refractory to Abx treatment because they often become trapped within stones
Causes nausea, cramping, and is associated with the consumption of raw shellfish
Vibrio parahaemolyticus
-although this FREE-LIVING salt bacteria is related to V. cholerae, the symptoms are much milder
Causes a paroxysmal cough ending with an inspiratory “whoop” as air rushes over the swollen glottis
Bordetella pertusis
-the vaccine includes the purified virulence factors FILAMENTOUS HEMAGGLUTININ (FHA) and PERTUSIS TOXOID, and is administered at 2, 4, 6, and 18 months along with the vaccine for Corynebacterium diphtheriae and Clostridium tetani in the DaPT vaccine
