Flashcards in Lecture 7 Deck (48)
Diseases of Gram negative Neisseria
Neisseria Meningitides and Neisseria Gonorrhea
What type of agar does Neisseria need?
chocolate agar (heated blood agar)
What is the shape of Neisseria Meningitides?
kidney shape arranged in pairs with wide polysaccharide capsule, strict aerobe
Does Neisseria Meningitides contain plasmids?
no plasmids since no exotoxin production
How is meningitides transmitted?
airborn droplets- colonize mucous membrane of nasopharynx and URT
Where is meningitides common?
crowded places, military camps and student camps
virulence factors of meningitides
1. polysaccharide capsule which resists phagocytosis, endotoxin present in cell wall responsible for septic shock and septicemia, and organism produces IgA protease, which helps to attach to mucous membrane
What does meningitides cause and describe it
meningitis- fever, headache, nuchal rigidity, disorientation, turbid CSF, leukocytes, organisms inside neutrophils
What causes septic shock and describe it
bacteremia- fever, shock, widespread purpura and disseminated intravascular clotting
What is the physically demonstrable symptoms of meningitis
Brudzinski's sign- severe neck stiffness causes a patients hips and knees flex when neck is flexed
define Kernig's sign
Severe stiffness of the hamstrings causes inability to straighten the leg when the hip is flexed to 90 degrees
Where do you do a lumbar puncture?
3rd or 4th lumbar spine
What does hemorrhage in adrenal cortex lead to?
adrenal insufficiency known as waterhouse=friedrichen syndrome
2 organisms causing meningitis in children
Pneumo and meningo cocci
Treatment for meningitis
penicillin G, sulphonamides are also effective
Prevention for meningitis
chemoprophylaxis- rifampicin & ciprofloxin , vaccine available- meningo coccal vaccine contains capsular polysaccharides
Who is Nis gonorrhoeae symptomatic in?
men and asymptomatic in women
Where is Ni Gonorrhoeae found?
in genital tract- less commonly in anaorectal region and oropharynx
Examples of virulence factors
pili, cell wall lip oligosachride and IgA protease
where does genetic variation occur
in pili and outer membrane proteins as a result of chromosomal rearrangement
clinical manifestations of Nis. Gonorrhoeae in men
causes urethritis, painful urination and pus in urine-- gonorrhea- disseminated infection lead to septic arthritis in sexually active men
repeated infections of the urethra can lead to what?
urethral stricture-- occluding of the urethra
define reiters syndrome
non gonococcal urethritis, arthritis and conjunctivitis which is immunological
clinical manifestations of Nis. Gonorrhea in women
mostly asymptomatic- in few it can cause purulent vaginal discharge and inner menstrual bleeding- lead to PID, ectopic pregnancy, salphingitis
Can fetuses contract nis. gonorrhoeae?
yes- when passing through the birth canal- severe purulent bilateral conjunctivitis can occur- other STDs can co-exist
Treatment for Nis. Gonorrhoeae
Penicillin G is drug of choice- nowadays ceftrioxone is given
Prevention of Nis. Gonorrhoeae
use of a condom- there is no vaccine- babies can be given erythromycin drops for eyes
List the 4 organisms in the Gram + Category
Bacillus, Clostridium, Corney bacterium diphtheriae and lysteriae momcytogens
Which gram + groups are spore forming?
Bacillus and Clostridium