1-Microbiology Flashcards by Dominic Vanchieri

3 Mechanisms of Bacterial Meningitis?

Infect cells lining barrier
Passively transported across BBB
Carried across in infected leukocytes

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Major bugs involved in neonatal bacterial meningitis?

Strep B, Enterics (E.Coli), Listeria

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Major bugs involved in bacterial meningitis in infants and children?

Strep Pneumo, Neisseria Meningitidis, H. Influenzae B(vaccine now)

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Major Bug for Teens/Adults?

Elderly?

Teens/Adults: N. Meningitidis

Elderly: S. Pneumoniae

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What is the most important virulence factor for the bacteria that commonly cause meningitis?

Capsule

N. Menin, H. Influenzae, S. Pneumo, Group B strep, E.Coli

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Which bacteria should be suspected if there is a petechial skin rash?

Meningococcal Meningitis

Niesseria Type

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What population types are at highest risk for Pneumo Meningitis?

Pediatrics, Immunocomprimised, Elderly, Sickle Cell

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Discuss the proper dx techniques for Pneumococcal meningitis.

Culture, Gram Stain, Increased PMNs in CSF

Gram + Diplococci

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What is the proper treatment for pneumococcal meningitis?

Combo therapies are the DOC.

Ceftriaxone + Ampicillin

Ceftriaxone + Vancomycin if prevalence is >2% in community

DONT USE FLOUROQUINOLONES in children

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Discuss the dx info for niesserial meningitis?

Gram (-) diplococcus
Increased WBC
Culture

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Which serotype of N. Meningitis is not protected against with the vaccine?

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Discuss treatment options for Neisserial meningitis?

Ceftiraxone + Ampicillin

Give chloramphenicol to pts. who are allergic to penicillins

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What type of prophylaxis should be given to the family members of pts. dx with niesserial meningitis?

2d of Rifampin prophylaxis to clear the nasopharyngeal carriage of the bug.

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When is a H. Influenza B meningitis infection most likely seen?

In unvaccinated children. Will be cultured on chocolate agar with x-heme and NAD factors.

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How should a H. Influenza B meningitis infection be treated?

DOC is Cephalosporins (Ceftriaxone)

RIfampin prophylaxis for family in contact

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What is the most common way of transmitting neonatal meningitis?

Maternal vaginal tract where there is a rupture of membranes.

Group B strep = most common

Ecoli, Listeria

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What are the key dx characteristics for groub B strep meningitis in neonates?

Gram + cocci
B-Hemolytic on blood agar
Optochin/Bacitracin Resist.
CAMP positive
CSF Antigen

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Describe treatment for Group B Strep

DOC is Penicillin G

- vanco for allergic patients.

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Describe key dx information for E. Coli meningitis?

CSF culture - Gram (-) rods, MacConkey, Lactose fermenting, Indole +

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Describe proper treatment for an E. Coli meningitis infection?

DOC - Ceftriaxone

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Describe key dx information for Listeria causing meningitis?

Neonate late onset

Culture - gram (-) rods
but gram stain usually negative
COLD SELECTION!!

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Proper course of treatment for Listeria?

Ampicillin is DOC

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What are the to major neurotoxins discussed by keller?

Clostridia spp.

Botulinum/Tetani

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Describe the dx. of C. botulinum?

Based on presentation usually

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Treatment for C. Botulinum?

Antitoxin, Stomach lavage, DO NOT TREAT INFANT BOTULISM WITH ANTIBIOTICS

Describe dx of C. Tetani?

Works via blocking glycine and GABA release, causes spasm and lock-jaw. CSF usually normal

Describe Treatment for C. Tetani?

Supportive care. DOC - metronidazole Tetanus Booster

What is the meaning of Aseptic meningitis?

Caused by bacteria and viruses, but there is no evidence of bugs in the CSF

Describe proper dx of neurosyphilis (aseptic meningitis?

+ VDRL in CSF Increased WBC Decreased Glucose Increased Proteins

Describe the best treatment for neurosyphilis?

High dose Penicillin G must be attained in the CSF.

Describe proper dx of Lyme disease (b. bergdorferi)

Kernig and Brudzinski will be negative, because it is milder than typical meningitis. Ab titer followed by immunoblot History of tick bite

Describe proper course of treatment for Lyme meningitis?

Ceftriaxone is DOC maybe Penicillin G alternative Most Treatments aren't highly effective.

Describe the proper dx. of Leptospira-caused aseptic meningitis.

aerobic, ice-tonge appearance on micro animal handlers at risk spirochete in blood culture.

Discuss proper treatment for Leptospira Interrogans?

IV penicillins - G for severe - Ampicillin, amoxicillin, doxycycline for mild

Describe proper dx. of M. Tuberculosis cuased aseptic meningitis.

Acid-Fast bacilli, Gram + Pulmonary symptoms PPD+ Release of IFN-gamma by lymphocytes.

What is the proper course of treatment for aseptic meningitis caused by M. Tuberculosis? Why are these drugs all so successful?

``` RIPES Rifampin Isonazid Pyrazinamide Ethambutol Streptomycin ``` They are good because they readily enter CSF in the presence of meningeal inflammation.

What does a tzank smear test for?

Herpetic viruses (VZV, HSV, CMV)

Describe the most common CNS fungal infections/

Cryptococcus (non-invasive?) Coccidioides, Histoplasma, Blastomyces

Describe the common parasitic infections of the CNS (Protozoa and Metazoa)?

Protozoa - Amoeba, Malaria, Toxoplasma Metazoa (worms) - Trichinella Spirals, Taenia Solium

Describe the types of patients that will become infected by cryptococcus neoformans. Proper DX?

Encapsulated yeast, found mainly in HIV/AIDS patients. India Ink Staining, negative contrast. Serology Increase protein and WBCs in CSF

Discuss treatment for Crytpococcus in Aids Patients.

Amphotericin B + Fluctosine for 4-6 weeks and Fluconazole for LIFE

Describe the likely infection if a patient presents with a immunocompromised patient with meningitis symptoms. CSF has increased proteins and WBCs and low glucose. Serology KOH prep of tissue Culture on sabouraud dextrose agar

Coccidioides Immitis | Treat with Amphotericin B and Fluconazole for lifetime

Discuss dx and tx of Naegleria Fowleri?

Autopsy.. they die CSF microscopy reveals trophozoites Treat with Amphotericin B if you catch it in time...

Discuss the dx and tx for malaria

Blood Smear - trophozoite(band) or gametocyte (round) under microscope Treat with Chloroquine (DOC) IV Quinine for severe cases

Most common etiology for viral conjunctivitis?

Adenovirus

What is the most common presentation for Toxoplasmosis

Encephalitis, parasitic Most common cause of encephalitis in AIDS Patients Dx - CT scan (ring enhancing lesions (Aids Pts.), serology

Describe course of treatment for Toxoplasmosis

Sulfonamide+Primethimine

Course of treatment for T. Brucei with CNS involvement?

Melarsoprol is DOC

What is the most important eye infection worldwide?

Trachoma (adults) via Chlamydia Trachomatis.

What are the differences in presntation and treatment of C. Trachomatis eye infections in adults vs. neonates?

Adults: Trachoma (A-C) - recurrent, causes blindness! Treat with PO azithromycin + topical doxycycline. Neonates: conjunctivitis (D-K), treat with PO erythromycin

Baby with conjunctivitis, Gram - diplococci, cultured on Thayer Martin Chocolate Agar!

Mommy had Gonorrhoeae Severe neonatal conjunctivitis Tx Penicillin G or Ceftriaxone if resistant

Describe the clues for dx of HSV kerato conjunctivitis.

Multinucleated giant cells on tzank smear

Describe treatment for HSV infections?

Acyclovoir is DOC

Describe the dx clues for CMV

aids pt. or immunocomprimised Decreased acuity/loss of visual fields Histo - owl's eye inclusions

Describe tx for AIDS patient with CMV chorioretinitis?

IV foscarnet is DOC non aids - IV ganciclovir

Common fungal ocular infections in Northern states? Southern states?

Northern - Candida and Aspergillus spp. Southern - Fusarium

Which are the notable filamentous fungi causing eye issues?

Fusarium(south) - satellite lesions and Aspergillus(north)

What type of fungus is candida?

budding yeast with pseudohyphae and germ tubes

What is the dx stuff and drug of choice for a Fusarium karatitis?

Dx - KOH prep, sabourad dextrose agar Rx - Natamycin topical DOC

Dx and Rx for candida albicans endopthalmitis?

Funduscopic exam Rx- Amphotericin B then fluconazole

What is the bug that causes neurocsticercosis?

Taenia Solium causing cysts in the eye.

Treatment course for Taenia solium?

Surgical Removal of Cysts | Praziquantel or albendazole

1-Microbiology Flashcards

(62 cards)