Neisseria Flashcards
What are some general characteristics of the family Neiseriaceae ?
- gram (-) cocci in pairs
- aerobic to facultative anaerobic
- some species require increased CO2
- Capnophilic (needs increased CO2)
- Oxidase (+)
- Catalase (+)
- non motile
Where is Neisseria usually isolated on ?
Thayer-Martin agar
- agar plate that contains antibiotics and nutrients that facilitate growth of Neisseria species while inhibiting growth of contaminating bacteria and fungi
What type of Neisseria does Thayer-Martin agar prefer the growth of ?
Neisseria Gonorrhea & Neisseria Meningitidis
What type of Neisseria does Thayer-Martin have no growth on ?
Neisseria: flavescens, sicca, & subflava
- non pathogenic
How do you collect Neisseria for specimen collection ?
- swabs from mouth, anus, vagina, cervix, urethra, and eye
- urine
- sterile fluids (cerebrospinal fluid, synovial joints)
- sputum specimens
- blood cultures
How do you collect and isolate Neisseria ?
- inoculate media immediately after collection
- needs to be moist and a room temp
- don’t refrigerate (cold temps can kill fastidious organisms)
- increase amount of CO2 in container
What collection container do you use for isolation media ?
- BAP
- Chocolate agar
- Modified Thayer-Martin (MTM) for nonsterile specimens
What are the requirements for growth on BAP ?
25 C and 35 C in increased CO2 (candle jar or CO2 incubator)
What are the requirements for growth on MTM ?
35 C with CO2
What are the requirements for growth on Nutrient agar ?
35 C with CO2
In rapid fermentation tests what fermentation products are you testing ?
- dextrose (glucose)
- lactose
- sucrose
- maltose
In a rapid fermentation test what does a positive and negative result look like ?
- (+): yellow color
- (-): red color
- drop in pH= color change of phenol red indicator in the medium
What happens in a Rapid Fermentation test ?
if bacteria contains enzymes needed to metabolize the carbs, then acidic products are made
What happens in a Polymerase Chain Reaction (PCR) ?
amplifies DNA directly from the specimen submitted
- urogenital swabs, eyes, urine
What happens in a Accu-Probe diagnostic procedure ?
labeled DNA with complementary Neisseria Gonorrhoeae rRNA
- detects bacterial nucleic acid
- can be performed on the cultivated organism in about 1 hr
What is Neisseria Gonorrhoeae ?
sexually transmitted disease (almost exclusively)
Where is the primary infection of N. Gonorrhoeae found ?
Anogenital
- anus
- urethra
- cervix
Non-genital
- eye and pharynx
- neonates may acquire infection during birth
What are the characteristics of Neisseria Gonorrhoeae in males ?
visible symptoms from 1-7 days from exposure of infection
- purulent urethral discharge
- severe pain upon urination
How do you do a preliminary ID of Neisseria Gonorhoeae in males ?
gram stain of discharge
- no normal flora in urethra
- gram (-) diplococci (intracellular: inside WBCs)
- start treatment
- gram stain (-) or unclear = ID by other means
How color is urethral discharge ?
white, yellow, green
What are some characteristics of Neisseria Gonorrhoeae in females ?
- vaginal discharge will contain normal flora
- gram stain is not useful in presumptive ID
- must use other means of ID (PCR-current)
What are some symptoms of Neisseria Gonorrhoeae in females ?
- vaginal discharge
- lower abdominal pain
- abnormal bleeding (between menstraul cycles)
- symptoms may go unnoticed as the symptoms are milk
- if untreated it can lead to PID
What are some complications of PID (pelvic inflammatory disease) ?
- formation of scar tissue that blocks fallopian tubes
- ectopic pregnancy (pregnancy outside womb)
- infertility (inability to get pregnant)
- long term pelvic/abdominal pain
What can result from Neisseria Gonorrhoeae Sequelae ?
- PID (pelvic inflammatory disease)
- leading cause of sterility in females
- septicemia, prostatitis, urethritis
- disseminated arthritis (bacteria invade joints)
How is Neisseria Gonorrhoeae identified ?
- On Chocolate Agar: opaque, grey white, glistening colonies; hard to grow on blood agar
- Oxidase & Catalase (+)
- Glucose (+) & NO3 (nitrate) (-)
How does molecular detection do ?
detects bacterial nucleic acid
- more rapid than culture (hours vs days)
- more sensitive and selective than culture
- replaces culture for the most part
How do you perform a Oxidase test ?
- dip swab into reagent and then touch an isolated suspect colony
- observe for color change within 10 secs (bluish-purple= +)
What is the treatment for Neisseria Gonorrhoeae ?
- Azithromycin or Tetracycline
- (penicillin used to be the best antibiotic but resistant strains have beta-lactamase enzyme which inactivates penicillin which causes resistance)
What are some characteristics of Neisseria Meningitidis ?
- colonies are round, convex, glistening, and blue-gray color
- aerobic
- non motile
- oxidase & catalase positive
Where is Neisseria Meningitidis commonly found ?
oropharynx and nasopharynx of humans
- carriers are asymptomatic (5% to 30& carrier rate)
When is Neisseria Meningitidis most prevalent ?
higher in the winter with people living in close quarters
- dorms
- military
- homeless shelters
What is the infections steps of Neisseria Meningitidis ?
- colonize the nasopharynx initially
- invades bloodstream and CNS
- sudden onset of frontal headache followed by stiff neck and rigidity of spine
- progression of infection- vomiting, myalgia (joint pain)
What is the incubation period of Neisseria Meningitidis ?
1 to 7 days
What causes Waterhouse-Friderichsen syndrome ?
Disseminated Intravascular Coagulation (DIC)
- use up clotting factors and bleeding into organs
- DIC can cause petechial rash/purpura
What happens with Waterhouse-Friderichsen syndrome ?
- bleeding in the adrenal glands
- causes purpura (purple rash on the skin due to small blood vessels bleeding due to DIC)
- causes rapid death
How do you prevent Neisseria Meningitidis ?
vaccines, ceftriaxone, ciprofloxacin, azithromycin, rifampin
- remains susceptible to penicillin
- still do beta lactamase test
What respiratory infection can be caused by Neisseria Meningitidis ?
- pneumonia
What are some characteristics of Moraxella Cararrhalis ?
- grey to white, smooth, opaque colonies
- oxidase & catalase (+)
- nitrate & DNase (+)
- grows well on BAP and Choc
What infections are caused by Moraxella Catarrhalis ?
- acute bronchitis and pneumonia
- maxillary sinusitis, meningitis, endocarditis
- most common specimen submitted- sputum
Where is Moraxella Catarrhalis found ?
normal flora of the upper respiratory tract
What is the treatment for Moraxella Catarrhalis ?
- penicillin and ampicillin resistant
- have beta lactamase enzyme
- erythromycin, tetracycline, chloramphenicol, cephalosporins
