Microbiology (Done) Flashcards
Gram (+) bacteria will stain ________ because of the thick, exposed peptidoglycan layer.
PURPLE
Gram (-) bacteria will stain _________ b/c the outer membrane prevents dye from staining the peptidoglycan cell wall.
RED
Which 4 drugs/drug classes interfere with cell wall synthesis, leading to bacterial cell lysis & death?
- Bacitracin
- Penicillins
- Cephalosporins
- Vancomycin
What form of reproduction do Bacteria undergo?
Binary fission»a form of asexual reproduction
During which phase of bacterial growth are Antibiotics the most effective?
LOG phase»cells are growing and dividing at an exponential pace during this peak period of activity
What are Facultative Anaerobes?
Bacteria that do not require oxygen for growth, but will grow BETTER in its presence.
Gram (+) _______ can form endospores.
RODS
What are 2 examples of spore-forming bacteria?
- Bacillus anthracis (anthrax)
2. Clostridium botulinum
Approximately half of all ocular infections are caused by ___________.
Staph aureus
What are the 4 main gram (+) COCCI bacteria?
- Staph aureus
- Staph epidermidis
- Staph pyogenes
- Staph pneumoniae
What do the Catalase & Coagulase test show on Staph aureus?
Catalase (+) and Coagulase (+)
What do the Catalase & Coagulase test show on Staph epidermidis?
Catalase (+) and Coagulase (-)
What does the Catalase test show on Staph pneumoniae?
Catalase (-)
What do the Catalase & Coagulase test show on Staph aureus?
Catalase (-) and Coagulase (+)
Which bacteria is responsible for Toxic Shock Syndrome?
Staphylococcus aureus
What is the most common cause of Post-operative Endophthalmitis?
Staph epidermidis
What is responsible for pediatric bacterial conjunctivitis & corneal ulcers?
Strep pneumoniae
What is the main test that should be done in order to differentiate Staph and Strep bacteria?
The Catalase test differentiates
|»_space;Staph are catalase (+) and Strep are catalase (-)
How do you differentiate Staph aureus from other forms of Staph?
Staph aureus is Coagulase (+), and ALL OTHER FORMS OF STAPH are coagulase (-)
What are the 3 main Gram (+) RODS?
- Bacillus anthracis (spore-forming)
- Clostridium
- Corynebacterium diptheriae (can penetrate an intact corneal epithelium!)
What are the 2 main Gram (-) RODS?
- Pseudomonas Aeruginosa
2. Haemophilus influenzae (culture on chocolate agar)
What are the 4 main Gram (-) COCCI?
- Neisseria gonorrhea (chocolate agar)
- Neisseria meningitidis (blood agar)
- Moraxella (angluar blepharoconjunctivitis)
- Bordatella pertussis (whooping cough)
What can E.coli cause?
Conjunctivitis, corneal ulcers, and endophthalmitis
What are 2 ocular findings from Syphilis?
- Argyll-Robertson pupil
2. Interstitial Keratitis
Chlamydial Inclusion Conjunctivitis is caused by which serotypes?
Serotypes D-K
Trachoma Conjunctivitis is caused by which serotypes?
Serotypes A-C
What is the #1 bacterial STD in the US? what are the ocular manifestations of this bacteria?
- Chlamydia
2. chronic red eye, large inferior palpebral conj follicles
What is the leading cause of Ophthalmia Neonatorum?
Chlamydia
What is the classic triad of symptoms from Rickettsia?
- Headache, Fever, and Rash
|»_space;treat with doxycycline
Why is myoplasma resistant to Penicillin?
> > Because this particular bacterium has NO cell wall, so Penicillin will do nothing since it targets cell walls
What is the most common cause of Epidemic Keratoconjunctivitis?
Adenovirus
What are the serotypes responsible for EKC?
Serotypes 8, 19, and 37
What is the difference between Herpes Simplex type 1 and type 2?
- Type 1 primarily ORAL (main cause of EKC)
2. Type 2 primarily GENITAL (sexually transmitted)
What is the most common ocular infection AND the leading cause of blindness in AIDS?
Cytomegalovirus
Cytomegalovirus is prevalent in AIDS patients with CD4 counts of _____.
CD4 counts of less than 50!
What condition can PoxVirus be responsible for?
Molluscum Contagiosum
|»_space;Multiple nodules should raise suspicion for HIV!
Treatment of Candida albicans (yeast infection) includes which 3 anti-fungals?
- Ketoconazole, Mycostatin, and Fluconazole
What is the Clinical Triad for Histoplasmosis?
- Peripapillary atrophy of optic nerve
- Punched out peripheral lesions
- Maculopathy
What is the most common cause of Fungal Corneal ulcers?
Candida Albicans
LICE (Pediculosis Capitis) can cause ______________, with symptoms of itching and burning.
Chronic follicular conjunctivitis
Toxoplasmosis infections start in the _______ and can spread to the _________.
Histoplasmosis infections start in the _______ and can spread to the _________.
- Retina, choroid
2. Choroid, Retina
How do the signs compare to the symptoms if a patient has Acanthamoeba?
Symptoms OUTWEIGH the clinical signs
|»_space;pt. in severe pain, but when you look w/ slit lamp, you see a tiny dot (ulcer).
