Microbiology Flashcards
Gummas can occur in various locations with syphilis infection. n what stage of the infection are gummas first found?
Gummas are the defining characteristic of tertiary syphilis. There is usually a latency period between secondary and tertiary syphilis of 2–20 years.
Which bacteria are Gram-negative aerobic rods?
The answer is pseudomonas aeruginosa.
Gram-negative aerobic rods are rare, with the exception of Pseudomonas.
Neisseria gonorhea is what kind of bacteria?
Gram-negative diplococcus.
Streptococcus pyogenes is what kind of bacteria?
pherical Gram-positive bacteria.
Treponema pallidum is what kind of bacteria?
Gram-negative spirochaetes
Haemophilus influenzae îs what kind of bacteria?
Gram-negative, pleomorphic, coccobacilli bacteria
Which organisms contain ribosomes, do not have a rigid cell wall but cannot be grown on inanimate culture?
Chlamydia
Viruses do not have ribosomes.
Name some herpes viruses:
Epstein-Barr virus, cytomegalovirus, roseolovirus, Kaposi’s sarcoma-associated herpes virus
Which organism causes lymphogranuloma venereum?
The answer is chlamydia trachomatis L1–L3.
Which organism causes causes cervicitis, pelvic inflammatory disease and urethritis.?
Chlamydia trachomatis D–K
Which organism causes ocular trachoma?
Chlamydia trachomatis A–C
What is the potential cause of small white umbilicated white papules on the labia majora?
Molluscum contagiosum
What presents with multiple painful genital ulcers and lymphadenopathy?
Haemophilus ducreyi
Which infection is known to produce an aplastic crisis in people with sickle cell disease?
Parvovirus B19 infections lead to an aplastic crisis if there is a marrow strain, and hydrops fetalis and fetal death are complications of intrauterine parvovirus B19 infection.
What is the incubation period for varicella infection?
10–20 days.
Which pathogen is commonly responsible for cellulitis?
Streptococcus pyogenes
Which organism is associated with clue cells?
Gardnerella vaginalis
Which organism is associated with koilocytes?
Human papillomavirus
A pregnant woman is diagnosed with toxoplasmosis.
What is the drug of choice for reducing the risk of fetal infection?
Spiramycin
Toxoplasmosis gondii is an obligate intracellular protozoan.
Spiramycin is a macrolide antibiotic and has been shown to reduce the risk of mother-to-child transmission in pregnant woman by up to 70%
A 30-year-old woman presents to the antenatal clinic with a history of cytomegalovirus (CMV) infection.
Which test would be the most sensitive for diagnosis of congenital infection in pregnancy?
Amniotic fluid PCR
Serological diagnosis of primary CMV infection during pregnancy can be difficult because CMV IgM, while suggestive of recent infection, can remain positive for many months and can also represent reactivation of past infection.
A 30-year-old woman presents to the antenatal clinic after a visit to her home country in Africa. She is suffering from flu-like symptoms, myalgia and her posterior cervical lymph nodes are found to be enlarged. Her temperature is 38.4°C.
Diagnosis?
The answer is toxoplasmosis.
Acute toxoplasmosis may be present with the above symptoms. The lymphadenopathy is characteristic. The white blood count, ESR and CRP are usually normal
A 29-year-old woman who is 39 weeks pregnant presents to the delivery suite in labour. Her previous child was affected by group B streptococcus (GBS) infection. She is allergic to penicillin.
Which antibiotic should be prescribed for her as a prophylaxis for GBS?
Clindamycin
Vancomycin and erythromycin can potentially be used when clindamycin is not recommended.
If meticillin-resistant Staphylococcus aureus is suspected, which antibiotics should be used?
vancomycin or teicoplanin.
What type of fungus is Candida albicans?
The answer is yeast-like fungus.
Unlike true yeasts, candida forms long-branching filaments and therefore, it is classified as a yeast-like fungus.