UWorld Test 5/27/2014 - Micro Flashcards
What causes lymphogranuloma venereum? What is the ppt? Tx?
Chlamydia trachomatis serotypes L1,L2, L3. initiall - small painless ulcer on gentials. After some time=>painful swollen inguinal nodes that rupture/ulcerate “buboes”. Tx: doxycycline
What is diagnosed with “scotch tape test?” Occurs frequently in? Tx?
Enterobius vermicularis (pinworm) - most common helminthic infection. Occurs frequently in school aged children. Tx: bendazole. Pyrantel pamoate for pregnant women.
PID is most commonly caused by?
Chlamydia and Neisseria G. PD => ectopic pregnancies in 50% of causes
Most common cause of E. Coli bacteriemia is?
UTI
What is the most common cause of gram negative sepsis?
E Coli
What is the most common cause of septic arthritis in sexually active young people?
N Gonorrhea
Freshwater contact with dysuria and blood in urine- think??
Schistosomiasis.
What is the host of schistosomaias? What is the treatment?
Snail host. Infectious larvae (cercariae) penetrate human skin. S japonicum and manoson =L liver and spleen granulomas, fibrosis and inflammation. Chronic infection with S haematobium => urinary problems => sq cell carcinoma of the bladder (painless hematuria). Tx: Praziquentel
What is the major virulence factor for strep pyogenes
Protein M. Inhibits phagocytosis and activation of complement. Cytotoxic for neutrophils and mediator of bacterial attachement.
What is the most important virulence factor for uropathogenic E Coli?
Fimbraie/ Pilus - especially P-1 pilus.
Recurrence of genetial herpes is prevented by?
Daily dose of acyclovir, famciclovir or valacyclovir after first episode
Anal squamous cell carcinoma is a/w which virus?
HPV 16, 18, 31 and 33. Also cervical squamous cell carcinoma. HIV positive males have higher risk for infection
What is the most common cause of viral hemorrhagic cystitis (hematuria and dysuria) outbreaks in children?
Adenovirus
Acutre rheumatic fever follows what kind of infection vs acute streptococcal glomeruloneprhitis?
ARF: streptococcal pharyngitis, ASGN: streptococcal pharyngitis and skin infection (impetigo)
What are the common organisms that cause 1) urethritis 2) cystitis 3) pyeloneprhtiis
1) C. Trachomatis and N. Gonorrhae 2) Cystitis: E Coli, s. saprophyticus (half of UTIs in sexually active young women), Proteus, Klebsiella, Enterococci. 3) same as cystitis
What are the sw of 1) urethritis 2) cystitis 3) pyelonephritis
1) pain or burning sensation with urination, urgency of frequent urination 2) asymptomatic or symptomatic. Suprapublic tenderness and pain with frequent urination 3) flank pain, CVA tenderness fever, chills, hematuria wth casts
What labwork is done to dx 1) urethrtisi 2) cystitis and 3) pyeloneprhtiis?
1) UA: +WBCs 2) UA and Micro: + leukocyte esterase, + nitrites, + bacteria, + WBC, +RBC occasionally 3) UA and Micro: same as cystitis but also WBC casts indicatd renal based pyruia. CBC: elevated WBC
What is the toxic component of LPS? What does it do?
Lipid A. Causes activation of macrophages leading to widespread release of IL-1 and TNF-alpha causing signs of sepsis and shock.