Exam 6 (STDs and UTIs)

Question 1

39 yo male presents to hospital with tender penile ulcer on foreskin present for 2 weeks accompanied by swollen tender right sided inguinal lymph nodes. Treated for presumed syphilis with high dose penicillin. 1 week later, ulcer was unchanged, but developed inguinal lymphadenopathy on left side. Serologic tests for syphilis were negative as were direct fluorescent antibody tests. HSV tests were negative. What is most likely diagnosis? Treatment?

Answer 1

• Chancroid (causative agent = H. ducreyi). Treatment = macrolide

Question 1

HPV. Describe diagnosis

Answer 1

5.) Diagnosis: - Clinical appearance sufficient for diagnosis. Hyperkeratosis and koilocytes (halo surrounding hyperchromatic nuclei) seen in histology from tissue sample. - PCR to identify HPV serotypes

Question 1

Types of UTIs

Answer 1

• Upper/ascending UTI: nephritis/pylenonephritis = kidney +/- ureter infection - Lower UTI: a.) Cystitis: bladder infection b.) Urethritis: urethra infection c.) Prostatitis: prostate infection

Question 1

What is the typical treatment of pyelonephritis?

Answer 1

• Fluoroqunionoles for gram negs - Amoxicillin for gram positives

Question 2

HIV. Describe virion structure/virus types/tropism

Answer 2

1.) Virion structure/virus types - Retroviridae virus, +ssRNA (carries polymerase with it), enveloped - HIV-1: most common worldwide, including US - HIV-2: primary in W. Africa – longer asymptomatic period with lower mortality and more gradual decline in CD4 count - Tropism: a.) R5-tropic: uses CCR5 coreceptor, predominant early in disease b.) X4-tropic: uses CXCR4 coreceptor, associated often with rapid progression to AIDS - Structure: a.) p24 nucleocapsid protein encasing diploid genome b.) p17 matrix protein c.) envelope d.) gp120 attachment protein embedded into envelope e.) gp41 fusion protein embedded into envelope

Question 2

HPV. Describe diseases caused/clinical presentation

Answer 2

2.) Diseases caused/clinical presentation: a.) Genital/cervical warts (aka condyloma acuminatum): 1mm-2cm hyperkeratotic firm exophilic papules: itching, pain, burning b.) Respiratory papillomatosis/laryngeal papillomas: nodules in larynx. Typical in babies. Symptoms = altered cry, hoarseness, stridor, resp distress c.) Cervical cancer

Question 3

Most common bacterial sexually transmitted disease

Answer 3

• Chlamydia trachomatis

Question 4

What causes alterations in normal vaginal microbiota?

Answer 4

• Age - Menstruation - Hysterectomy or cervicectomy increase in bacterioides, E. coli and/or Enterococcus

Question 5

Symptoms of pylenonephritis

Answer 5

• Flank pain - Fever - Frequency, urgency, hematuria, dysuria - Severe cases: diarrhea, vomiting, tachycardia

Question 6

24 yo female presents to clinic with painless, wart-like vaginal lesions. Recently arrived in US from brazil. Exudate from warts were stained with Giemsa and intracellular bodies were apparent. What is most likely diagnosis? Treatment?

Answer 6

• Donovanosis aka granuloma inguinale (causative agent = K. granulomatis). Treatment = tetracycline, sulfamethoxazole, gent, cipro, erythro

Question 7

Test to distinguish non-enterobacteriaceae family of enteric bacteria from enterobacteriaceae enteric bacteria

Answer 7

• Oxidase pos = non-enterobacteriaceae enteric bacteria (campylobacter, fusobacterium, helicobacter, pseudomonas, vibrio) - Oxidase neg = Enterobacteriaceae = enterobacter, Escherichia, klebsiella, proteus, salmonella, shigella, Yersinia

Question 8

27 yo woman presents with a vaginal itching, odor, and discharge for 1 week. She has one partner who is asymptomatic. Speculum exam shows a strawberry cervix. There is scant white discharge with a fishy odor. Strawberry pattern is caused by inflammation and punctate hemorrhages on the cervix. What is likely diagnosis?

Answer 8

• Trichomoniasis (causative agent = T. Vaginalis)

Question 8

Enterobacteriaceae are family of enteric bacteria that are causative agents of UTIs. How are these diagnosed in lab – what are the characteristics of these organism and what tests are they positive/negative for? What are common virulence factors associated with them?

Answer 8

1.) Characteristics - Gram neg rods - Ferment glucose, reduce nitrate, catalase pos, oxidase neg 2.) Virulence factors - LPS, capsule (K), flagella (H), T3SS, sequester growth factors, antimicrobial resistance is high

Question 9

HSV. Describe diagnosis

Answer 9

5.) Diagnosis: - Typical clinical diagnosis: 1-2 mm groups of vesicles-pustules-ulcers - Tzanck smear – presence of syncytia (multi-nucleated) - PCR, IHC – to distinguish HSV-1/2

Question 10

31 yo feamle with malodorous discharge for 3 weeks. No associated vaginal itching or pain. Married and monogamous. Admits to douching about once per month to prevent odor but it is not working this time. On exam, her discharge is visible. Wet prep more than 50% of epithelial cells are clue cells. The pt most likely has an overgrowth of _______ and a reduction in ______ A. Yeast, lactobacillus B. Lactobacillus, small gram variable rods C. Small gram rods, lacto D. T.vaginalis, small gram variable rods E. G.vaginalis, T. vaginalis

Answer 10

Answer = C

Question 11

Name that ulcer! How would you confirm diagnosis? A.) Painful, non-indurated, recent travel B.) Painless, indurated, no travel C.) Painless, wart-like, indurated, bleeds easily, travel

Answer 11

• A.) Chancroid (H. ducreyi): rule out syphilis, HSV, pt presents with inguinal lymphadenopathy. If positive send for culture with chocolate agar (with X and V factors) - B.) Syphilis (T. pallidum): serology (non-treponemal and treponemal), darkfield microscopy for visualization of spirochetes - C.) Donovanosis (K. granulomatis): rule of syphilis, HSV, look for Donovan bodies under microscope (intracellular bacteria)

Question 12

HSV. Describe diseases caused/clinical presentation

Answer 12

2.) Diseases caused/clinical presentation a.) Genital herpes: - Lesion on vulva, cervix, peritoneum, penis, thighs, buttocks. Progression from macules – papules – vesicles – pustules – ulcers. Lesions are painful +/- pruritus, fever, inguinal lymphadenopathy, malaise. Primary infection lasts 3 weeks. Recurrent lesions less severe than initial, multiple times per year with prodrome (tingling/pain), heal within 7-10 days. b.) Neonatal herpes infection i.) skin, eyes, mouth ii.) encephalitis iii.) disseminated infection c.) Herpetic whitlow d.) Herpes labialis e.) Herpes simplex keratitis f.) Herpes simplex encephalitis

Question 13

How to distinguish in a micro lab between staph and strep?

Answer 13

• Catalase pos = staph - Catalase neg = strep

Question 14

HIV. Describe life cycle/pathogenesis

Answer 14

2.) Life cycle/pathogenesis a.) Attachment: gp120 binds CD4 (on T, mono and MO cells) leading to conformational change and binding to chemokine co-receptors (CCR5 or CXCR4) b.) Fusion: gp41 brings virion closer to host cell and mediates fusion c.) Reverse transcription: reverse transcriptase (pol) produces linear dsDNA of genome, it is highly error prone d.) Integration: viral integrase integrates viral dsDNA into host – genome now = provirus e.) Genome replication/transcription: provirus is transcribed and replicated f.) Budding: buds through PM at lipid rafts and leaves host g.) Protein cleavage/maturation: viral protease cleaves gag and gag-pol polyproteins leading to virion maturation – essential step

Question 15

How to diagnose a UTI?

Answer 15

• Symptoms - UA: a.) Pyuria = leukocyte esterase pos b.) Typically greater than 100,000 CFU/ml of bacteria (can have UTI with less) c.) E.coli = nitrite pos

Question 16

Leading cause of preventable blindness in the world?

Answer 16

• C. Trachomatis that causes trachoma

Question 17

Name that discharge! What is the disease, causative agent? A. Thick white cottage-cheese like odorless B. Frothy, yellow-green, foul smelling C. Mucopurulent D. Thin white grey fish odor

Answer 17

• A. Vulvovaginal candidiasis = C. albicans - B. Trichomoniasis = T. vaginalis - C. Gonorrhea or chlamydia - D. Bacterial vaginosis = reduction in lactobacillus in normal flora

Question 17

HPV. Describe characteristics of virus/serotypes

Answer 17

1.) Characteristics of virus/serotypes:hpv - Papovaviridae, dsDNA, non-enveloped Serotypes: - Laryngeal papillomas: HPV 6, 11 - Anogenital warts: HPV 6, 11 + high risk = HPV 16, 18, 31, 33. HPV 16 associated with ~50% of cervical cancers

Question 18

Causes of genital ulcers. Describe ulcers in each

Answer 18

1.) Syphilis (Treponema pallidum): painless ulcerated, indurated lesion 2.) Genital herpes (HSV): see viral STD lecture 3.) Chancroid (Haemophilus ducreyi): painful, non-indurated, soft ulcer with erythematous base 4.) Donovanosis/Granuloma inguinal: wart-like, non painful lesions that bleed easily and can cause significant damage

Question 18

True/false. Lactobacillus is a cause of UTI

Answer 18

• False

Question 18

HPV. Describe transmission

Answer 18

4.) Transmission: - Sexual transmission of genital warts

Question 19

Which of the following is not a complication/symptom of infection with N. Gonorrhoeae? A.) ectopic pregnancy B.) pustular rash C.) enteritis D.) conjunctivitis E.) pharyngitis

Answer 19

• Enteritis

Question 20

Reasons HIV is thought to escape immune system destruction

Answer 20

1.) Antigenic drift of gp120 2.) Destruction of CD4 T-cells, macrophages and monocytes 3.) Causes cell-cell fusion

Question 22

How to distinguish between lesions seen from syphilis vs chancroid?

Answer 22

• Syphilis chancres are painless, ulcerated and indurated - Chancroid lesions are painful, ulcerated with erythematous base Mnemonic: “You do cry with ducreyi” – H. ducreyi = causative agent of chancroid

Question 24

Three weeks after a normal birth, infant presents with rhinitis and a widespread desquamating maculopapular rash. No other reports of rashes/illness in household; however, mother experienced flu-like symptoms and disseminated rash during second month of pregnancy. What is the most likely diagnosis? Treatment?

Answer 24

• Congenital syphilis (causative agent = T. pallidum) . Penicillin, or if allergic, azithromycin or doxy

Question 25

What is asymptomatic bacteriuria? Are these treated? If so, with what

Answer 25

• Asymptomatic UTIs from two successive urine cultures with greater than 100,000 CFU/mL - Treated in: pregnant women, if pt is receiving urologic surgery, after renal transplant - Treatment = amoxicillin, cephalexin or nitrofurantoin

Question 26

Mycoplasma genitalium. Characteristics, disease caused, treatment

Answer 26

• Characteristics: small free-living bacteria, no cell wall, not stained by gram or acid-fast or other typical methods, fried-egg appearance, plasma membrane has sterols (stolen from host), extracellular, part of normal GU tract flora - Diseases: NGU in males, cervicitis/PID in females - Treatment: nothing that targets cell wall (they don’t have cell wall), treat with azithromycin, resistant to doxycycline

Question 26

24 yo sexually active male presents to clinic c/o 48 hour history of dysuria and penile discharge. Partner recently informed him she was diagnosed with chlamydia. Specimen collected and gram stain and urine samples for NAAT (nucleic acid tests). Pt sent home with rx for doxycycline given suspicion for chlamydia. Pt returns 10 days later c/o persistent symptoms as previously seen. Has been compliant with doxy. Gram stain reviewed with no organisms detected. NAAT negative for G/C. What is most likely cause of pts urethritis? What should happen next? A. N. gonorrhoeae B. C. trachomatis C. T. pallidum D. M. genitalium E. Ureaplasma F. H. ducreyi G. K. granulomatis

Answer 26

• Answer = M. genitalium. This is resistant to doxycycline, must be given rx for azithromycin

Question 27

Populations at risk for STDs

Answer 27

• Fetuses - Adolescents - Rape victims - CSW: commercial sex workers - MSM (highest rates of STIs traditionally) - WSW (lowest rates of STIs traditionally) - Drug and IV drug users

Question 27

Enterococcus (E. faecalis, faecium). Diseases caused, Characteristics/diagnosis, risk factors

Answer 27

• Diseases: UTI (hospital associated), peritonitis, endocarditis - Gram pos cocci, catalase neg, group D strep, resistant to optochin, tolerates high salt and bile - Risks: prolonged hospitalization, including tx with broad spectrum abx

Question 28

Disease caused by mycoplasma hominis. What is the treatment?

Answer 28

• Postpartum or portabortal fever and PID - Treatment is doxycycline (which M. genitalium is resistant to). Resistant to erythromycin.

Question 29

Vulvovaginal candidiasis. Cause, symptoms, risk factors, complications, diagnosis, treatment

Answer 29

1.) Cause: fungal infection, typically from Candida species (mostly C. albicans) 2.) Symptoms: itching, discharge - Discharge = thick, white, odorless, cottage-cheese/curd-like 3.) Risk factors: abx use, immunocompromised (can get esophagitis, disseminated infection), oral contraceptive use, diabetics 4.) Complications: recurrent infections, esophagitis and dissemination in immunocompromised 5.) Diagnosis - Gram pos stain or KOH prep shows budding yeast with hyphae and pseudohyphae if C. albicans, it also forms germ tubes at 37 degrees 6.) Treatment: 1-3 day topical azole for uncomplicated, 7-14 day topical or two doses or oral fluconazole for complicated

Question 30

Treponema pallidum. Describe diagnosis, special risk factors, treatment, prevention

Answer 30

3.) Diagnosis: - No growth in free culture, difficult in cell culture, no gram stain - Detection via dark-field microscopy or direct fluorescence with antibody - Serology = most common a.) Non-treponemal tests = antibody directed to cardiolipin (RPR, VDRL tests) b.) Treponemal tests = antibody directed to T.pallidum 4.) Special risk factors: higher incidence in MSM population 5.) Treatment: penicillin, if allergic, treat with doxy or azithro 6.) Prevention: no vaccine, safe sex

Question 31

Haemophilus ducreyi. Characteristics, epidemiology, diseases/clinical presentation, diagnosis, treatment, prevention

Answer 31

1.) Characteristics: gram-neg pleomorphic facultative anaerobe, small 2.) Epidemiology: rare in US, associated with travel to Africa, SE Asia, Caribbean 3.) Disease: - Chancroid: non-indurated and soft, tender/painful papule with erythematous base develops on genitalia/perianal area, can have multiple, presents with inguinal lymphadenopathy often 4.) Diagnosis: - Culture: requires factors X (hemin) and V (NAD) in “chocolate”/heated blood agar, catalase pos - Typically diagnosis via ruling out of syphilis (lack of pain at ulcer, no inguinal lymphadenopathy) and HSV testing 5.) Treatment: macrolide (azithro or erythro) 6.) Prevention: condoms

Question 31

When a pt presents to clinic with genital ulcers, what should you be most suspicious of?

Answer 31

• Genital herpes - Syphilis - Less commonly: chancroid or donovanosis (Granuloma inguinal) as these are rare in US, associated with travel

Question 33

Symptoms typical of urethritis and cystitis

Answer 33

a.) dysuria (painful urination) b.) frequency (multiple episodes of urination) c.) urgency (must urinate soon) d.) hematuria (blood in urine) e.) positive UA culture • no discharge typically seen

Question 34

E. coli (incl. UPEC). Characteristics, virulence factors, diagnosis,

Answer 34

• Characteristics: Gram neg rod - Virulence factors a.) Adhesins b.) Hemolysin: lyses RBCs and other cells = inflammation c.) LPS/endotoxin: inflammation d.) Type I pili: binds to mannose residues on epithelial surfaces e.) P pili (on some E. coli, for example UPEC): binds sugar residue on uroepithelial cells - Diagnosis: gram neg, glucose fermenter, lactose fermenter (pos on MacConkey’s agar = red), reduces nitrates, catalase pos, oxidase neg

Question 35

Predominant normal vaginal microbe. Describe

Answer 35

• Lactobacillus: gram pos, microaerophilic or anaerobic rod. Metabolizes glycogen to lactic acid causing pH of 4-5 - C. albicans

Question 37

Most frequent bacterial causative agents of community acquired UTIs

Answer 37

• # 1 = E.coli (UPEC) – up to 95% - #2 = Staph. Saprophyticus

Question 38

How many people are infection with syphilis in the US every year?

Answer 38

• 50,000

Question 39

HIV. Describe disease progression (including viremic load, CD4 levels, antibody production)/associated symptomatology

Answer 39

4.) Disease progress/symptomatology a.) Acute infection (3-6 weeks post infection) - Symptoms: fever, malaise, arthralgia, lymphadenopathy, sore throat, perhaps faint rash – similar to mono. - Viremia spikes during this period, CD4 relatively stable, antibody level rising (may not be detectable) b.) Chronic/latent (post acute infection, median time frame for untreated = 10 years) - Symptoms: mostly asymptomatic - Low viremia during this time, CD4 levels declining, antibody levels are still rising c.) AIDS - CD4 T-cells severely reduced to below 200/ul, although antibody levels are high initially they drop, viremic load begins increasing - Sympatomatology is d/t associated / opportunistic infections – signature infections: 1.) Oral hairy leukoplakia: EBV 2.) Pneumonia: pneumocystis carinii (previously jiroveci), MB tuberculosis 3.) Thrush: C. albicans 4.) CMV retinitis: CMV 5.) Neoplasms: Kaposi’s sarcoma (HHV-8), B-cell lymphoma 6.) Diarrhea: cryptosporidium, isospora belli

Question 40

Chalmydia trachomatis. Describe characteristics

Answer 40

1.) Characteristics: - obligate intracellular bacteria, lack peptidoglycan, gram neg like but cannot gram stain, exclusively human host, not spread on fomites - Biovars: a.) trachoma and b.) LGV - Serovars: based on MOMP (major outer membrane protein)

Question 41

Pseudomonas aeruginosa. Characteristics, diagnosis, pathogenesis, risks, treatment

Answer 41

• Characteristics: gram neg motile rod, minimalist - Diagnosis: oxidase pos, non-fermenter - Pathogenesis: a.) Toxin A: halts protein synthesis via ADP ribosylation of EF-2 b.) Leukocidin: pore forming toxin targeting leukocytes c.) PLC: membrane disruption d.) Capsule: anti-phagocytic e.) Pyocyanin: blue compound toxic to host f.) Pyoverdin: fluorescent green iron uptake protein - Risks: primarily nosocomial infection – UTI from pts with indwelling catheters and exposure to other hospital instrumentation, multiple antibioitics - Treatment: Antipseudomonal penicillins (Ticarcillin / piperacillin) + aminoglycoside (amikacin, gentamycin or tobramycin)

Question 42

HIV. Describe transmission

Answer 42

3.) Transmission: - sexual: most common route worldwide = heterosexual transmission, risk of transmission increased with other STDs esp those that breakdown mucosa - perinatal: risk = ¼ overall, highest risk at birth, can cross placenta, carried in breast milk - exposure to blood/body fluids: 0.3% skin puncture via needles, 0.09% mucosal membrane exposure

Question 43

35 yo woman presents with severe vaginal and vulvar itching. She also complains of a thick white non-odorous discharge. What is the most likely diagnosis?

Answer 43

• vulvovaginal candidiasis, likely d/t C. albicans

Question 44

Are enteric bacteria gram neg or positive?

Answer 44

• Neg, contain LPS

Question 46

Bacterial vaginosis. Cause, symptoms, risk factors, diagnosis, complications, treatment

Answer 46

1.) Cause: dysbiosis, overgrowth of anaerobes, reduction in lactobacillus *not considered STD 2.) Symptoms: vaginal pain, itching, burning, discharge - Discharge = thin, white/grey/milky, foul, fishy 3.) Risks: oral sex, douching, smoking, sex during menses, IUD, early age sex, new/multiple partners, WSW 4.) Diagnosis: - Amsel criteria: must meet three out of 4 a.) Discharge (see above) b.) Clue cells from wet prep c.) KOH whiff test – fishy odor d.) pH>4.5 - Nugent score: scoring from 0 to 10 looking on slides for lactobacillus dominance or absence and other cell types. 0 = lactobacillus dominant, 7-10 = lactobacillus absent, other bacteria present 5.) Complications: susceptibility to HIV and other STDs, preterm delivery, miscarriage, post delivery infection 6.) Treatment: a.) Anaerobes/parasites: oral metronidazole (inhibits NA synthesis) b.) Gram pos cocci and anaerobes: clindamycin

Question 47

15 yo hetero male to ED with 24 hour history of dysuria with pus-like drainage in his underwear and the tip of penis. Urine appeared clear and culture was negative. UA was positive for leukocyte esterase and multiple WBCS. Had 5 / 6 sexual partners in past 6 months with history of STDs. PEX indicated yellow urethral discharge with tenderness to tip of penis. Based on knowledge of symptoms and gram stain indicating gram neg intracellular diplococci, what is the likely diagnosis? What is the result of the maltose fermentation test? What is the treatment?

Answer 47

• Gonorrhea - Negative for maltose fermentation - Tx: ceftriaxone plus doxy/macrolide (for presumed chlamydia)

Question 47

Treponema pallidum. Describe characteristics

Answer 47

1.) Characteristics: spirochete, microaerophilic, has gram-neg cytology, but doesn’t gram stain, axial fibrils/endoflagella for motility, human reservoir

Question 48

HPV. Describe prevention

Answer 48

7.) Prevention: - Pap smears - Reduce high risk behavior - Vaccines (L1 capsid protein) a.) Quadrivalent = Gardasil b.) Bivalent = cervarix *only high risk 16/18 strains

Question 50

HSV. Describe transmission

Answer 50

4.) Transmission: - Direct contact with lesions, saliva, sexual transmission of genital herpes

Question 51

Neisseria gonorrhoeae (aka the clap, the drip). Describe diseases caused/complications

Answer 51

2.) Diseases caused - Gonorrhea: mucopurulent discharge (from urethra, cervix, epididymis, prostate or anus) and dysuria. Complications: PID in women leading to infertility and ectopic pregnancy. Can be asymptomatic in women, most male infections are symptomatic. - Gonococcemia = disseminated infection = septicemia, infection of skin and joints – associated with fever, migratory athralgias, suppurative arthritis, postural rash - Gonococcal opthalmia neonatorum = purulent conjunctivitis: mainly in newborn d/t exposure during vaginal delivery - Pharyngitis: mild to asymptomatic, typically accompanies genital infection - Anorectal gonorrhea

Question 53

Treponema pallidum. Describe disease caused/clinical presentation

Answer 53

2.) Disease/clinical presentation a.) Syphilis (transmission sexual or congenital) - Primary: characterized by chancre, which is painless ulcerated indurated papule at site of spirochete penetration lasting weeks to months. Pts typically don’t present at this phase d/t no pain. - Secondary: flu-like syndrome (ST, HA, fever, myalgias, anorexia, lymphadenopathy) with disseminated prominent skin lesions called condyloma lata (soft, flat, moist, pink-tan papules and nodules over body including palms, soles and skin folds). This occurs 2-8 weeks after chancre. Resolves over weeks to months. - Latent: asymptomatic lasting years to decades, transmission to others possible - Tertiary (late): diffuse chronic inflammation of virtually all organs. Gummas (granulomatous lesions) found in bone, skin and other tissues. Pts can present with blindness, dementia, arteritis – worst impacts in neurological and cardio systems. 1/3rd of pts proceed to this stage. - Congenital: infected mothers transmit to fetus, which if it doesn’t kill the fetus will cause them to have this. Symptoms included chronic rhinitis leading to destruction of nose = Saddle nose. Desquamating maculopapular rash. Condyloma lata also seen. Typically have Hutchinson’s triad: Hutchinson’s teeth, blindness and deafness.

Question 55

Examples of CoNS (coagulase neg staph). Characteristics?

Answer 55

• Examples = Staph saprophyticus and epidermidis - Characteristics = Gram pos, cocci clusters, catalase pos, coagulase neg, non-spore forming, non-motile, form biofilms - Saprophyticus = novobiocin resistant

Question 56

HPV. Describe treatments

Answer 56

6.) Treatments: a.) Laryngeal papillomas: surgical removal b.) Genital warts: cryotherapy, CO2 laser c.) Cervical neoplasias: low grade vs high grade - low grade = cauterization, cryo, CO2 laser, loop excision - high grade = hysterectomy, radiation, chemo

Question 58

What is the typical treatment of uncomplicated cystitis?

Answer 58

• TMP-SMX

Question 59

Which immunodeficiency below would result in increased susceptibility to gonococcal infection? A.) C8 deficiency B.) IgA C.) C4 D.) IgG E.) IgM

Answer 59

• C8 defiency. Any deficiency in C5b through C9

Question 60

Chlamydia trachomatis. Describe disease(s) caused and presentations/complications

Answer 60

2.) Diseases/presentation: a.) Trachoma (serovars A-C): chronic conjunctivitis that can progress to blindness - Transmitted by eye-to-eye droplets, fomites endemic in poorest countries. b.) Inclusion conjunctivitis - Acute conjunctivitis: mucopurulent discharge in sexually active adults - Neonatal conjunctivitis: infants exposed at birth, develops 1-2 weeks after birth c.) STI/urogenital infections (serovars D-K): - Men: dysuria, thin (yellow) mucopurulent urethral discharge. Complications = epididymitis, prostatis and can progress to Reiter syndrome (triad = urethritis, conjunctivitis and polyarthritis). Infection is symptomatic in men mostly - Women: (yellow) mucopurulent discharged, PID, can lead to sterility or ectopic pregnancy. Majority of infections are asymptomatic in women. d.) Lymphomagranuloma venereum/LGV (L serovars): genital infection, pt presents with painless lesion at infection site, inguinal lymphadenopathy, lymph nodes become supurative (buboes) and can rupture forming fistula. Proctitis (rectal inflammation) is commonly seen. Sporadic in US, prevalent in Africa, Asia and S. America. e.) Infant pneumonia

Question 61

HSV. Describe characteristics of virus/types

Answer 61

1.) Characteristics of virus/types: - Herpesviridae virus, enveloped, dsDNA, contains HSV polymerase - *HSV-1: oral lesions - *HSV-2: genital lesions - * not always true

Question 61

HSV. Describe treatment

Answer 61

6.) Treatment (target lytic infection, notso latent) Antiviral = a.) Acyclovir = nucleoside analogue – converted into active form via viral kinase and blocks polymerase b.) Foscarnet = non-nucleoside inhibitor – used in acyclovir-resistant infections, blocks polymerase - Oral lesions: not treated typically - Genital: primary = oral antiviral tx, recurrent = long term oral antiviral tx - Neonatal: IV antiviral tx - Ocular: topical antiviral tx

Question 62

Rank top three most prevalent STIs in the US

Answer 62

1.) Chlamydia trachomatis 2.) Neisseria gonorrhoeae 3.) Treponema pallidum

Question 64

Chlamydia trachomatis. Describe lifecycle/pathogenesis

Answer 64

3.) Lifecycle/pathogenesis: - Exists in two forms: EB (infectious) and RB (non-infectious). - Tropism for nonciliated, columnar, cuboidal and transitional epithelium - EB phagocytosed– progresses to RB (inclusion bodies in cell) – undergoes binary fission – converts back into EB form – cell is lysed and EB continues infecting other cells. Destroys epithelium and leads to inflammation through activation of cytokine response. LPS present with weak endotoxin activity. - Prolonged inflammation = fibrosis

Question 65

What are the most common causes of Non-gonococcal urethritis

Answer 65

• Chlamydia - Secondly: mycoplasma genitalium and ureaplasma urealyticum

Question 66

Neisseria gonorrhoeae (aka the clap, the drip). Describe diagnosis, special risk factors, treatment, prevention

Answer 66

4.) Diagnosis: - Culture from scrapings: gram neg aerobe diplococci in neutrophils, oxidase pos, catalase pos, non-spore forming and non-motile. Non-maltose fermenting. Requires chocolate agar/Thayer-Martin media. - Nucleic acid 5.) Special risk factors: - Deficiencies in late complement (C5b – 9 = MAC) 6.) Treatment: ceftriaxone plus doxy/macrolide to treat chlamydia, which is presumed with this infection. Neonates get prophylactic erythromycin ophthalmic ointment. 7.) Prevention: - No immunity to reinfection, patient education on safe sex practices

Question 67

S. saprophyticus. Characteristics, disease, pathogenesis, diagnosis

Answer 67

• Characteristics: gram pos, cocci clusters, non-spore forming, non-motile, forms biofilm - Disease: 2nd most common cause of community acquired UTIs - Pathogenesis: enhanced capacity to adhere to uroepithelial cells possible d/t hemagglutinin/adhesion - Diagnosis: a.) Gram pos b.) Catalase pos c.) Coagulase neg d.) Novobiocin resistant

Question 68

Symptoms of prostatitis

Answer 68

• LBP - Perirectal/testicular pain - Fever, chills and symptoms of cystitis (dysuria, frequency, urgency, possibly hematuria) - Positive UA culture

Question 69

Pt presents with symptoms similar to chlamydia and is given doxycycline. Returns 2 weeks later with worsening symptoms. What do you suspect?

Answer 69

• Suspicious of M. genitalium infection, which are resistant to doxycycline. Effective treatment against M. genitalium is azithromycin.

Question 71

Ureaplasma. Characteristics, disease caused, treatment

Answer 71

• Characteristics: small free-living bacteria, no cell wall, not stained by gram or acid-fast or other typical methods, plasma membrane has sterols (stolen from host), extracellular, part of normal GU tract flora in sexually active individuals - Disease: common cause of NGU in males - Treatment: Doxycycline. For recurrent infections, tx with azithromycin or quinolones

Question 72

How to tell Neisseria meningitidis and N. gonorrhoeae apart in culture?

Answer 72

• Both gram neg aerobe diplococci, oxidase pos, catalase pos, non-spore forming, non-motile - N. meningitidis ferments maltose (mnemonic: M = meningitidis, M=maltose), while N. gonorrhoeae doesn’t

Question 73

Menstrual toxic shock syndrome. Clinical presentation/symptomatology, cause and pathogenesis, diagnosis, treatment

Answer 73

1.) Presentation: diarrhea, general ill-feeling, high fever +/- chills, nausea, vomiting, sunburn rash with peeling of hands, feet, low BP, myalgias, HA, confusion, redness of eyes, mouth, throat, seizures 2.) Cause/pathogenesis: S. Aureus - Toxin mediated: TSST-1 exotoxin - TSST-1 penetrates mucosal barrier, is superantigen and activates high number of T cells leading to cytokine storm. - TNF-alpha (and beta) is primarily what leads to sepsis and shock 3.) Diagnosis: - Culture: gram-pos, catalase/coagulase pos, cocci clusters - Major criteria (all for diagnosis): hypotension, orthostatic syncope, less 90 SBP, macular erythroderma (sunburn-like rash), fever, skin desquamation (hands, palms, soles). Minor criteria (three): GI (diarrhea, vomiting), mucous membrane (oral, pharyngeal, conjunctiva, vagina), muscular (myalgia) 4.) Treatment: remove tampons (avoid in future), supportive measures, beta-lactamase resistant penicillin or vancomycin

Question 74

Bacterial cause of kidney stones?

Answer 74

• Proteus mirabilis via urease

Question 75

Klebsiella granulomatis. Characteristics, epidemiology, diseases/clinical presentation, diagnosis, treatment

Answer 75

1.) Characteristics: gram-neg intracellular rod, encapsulated 2.) Epidemiology: endemic in subtropics, rare in US, associated with travel 3.) Disease/clinical presentation - Donovanosis (aka Granuloma inguinale): wart-like lesions that are painless, but bleed easily, can rupture causing severe damage if untreated 4.) Diagnosis: slide shows Donovan bodies (which are bacteria inside of cells infected) via Giemsa staining 5.) Treatment: tetracycline, sulfamethoxazole, gent, cipro or erythro

Question 76

Proteus (proteus mirabilis). Characteristics, disease caused, pathogenesis, treatment

Answer 76

• Characteristics: gram neg, facultative anaerobe - Disease caused: UTI, kidney stones - Pathogenesis: a.) urease converts urea to Co2 and ammonia leading to alkalization of urine b.) alkalization = precipitation of mag and calcium = production of renal calculi (kidney stones) c.) produces biofilm - Treatment: TMP-SMX (trimethoprim-sulfamethoxazole)

Question 77

What is the CD4 T-cell count that is indicative of AIDS?

Answer 77

• Less than 200 cells/uL

Question 79

Neisseria gonorrhoeae (aka the clap, the drip). Describe pathogenesis/virulence factors

Answer 79

3.) Pathogenesis/virulence factors: - *Pilin: attachment, antiphagocytic - *Por protein/porin: promotes intracellular survival - *Opa (opacity) protein: attaches to eukaryotic cells - *LOS (lipooligosaccharide): endotoxin (lacks O-antigen), inflammatory stimulates TNFalpha - Outer blebs: absorb antibodies and enhance toxicity - IgA protease: destroys IgA in mucosa where it infects - Beta-lactamase * Exhibit antigenic variation to avoid immune system

Question 80

Trichomonas vaginalis. Characteristics, disease caused/presentation, pathogenesis, diagnosis, treatment

Answer 80

1.) Characteristics: pear-shaped protozoa with flagella and undulating membrane for motility, anaerobe, exists only in trophozoite (ie. Non-cyst) form therefore obligate parasite, reservoir is human UG tract 2.) Disease caused/presentation: - Trichomoniasis: majority of infected women are asymptomatic. Symptoms range from discharge to vaginitis with itching, burning and dysuria. Petechial hemorrhages on cervix, characteristic “strawberry cervix” - Discharge = yellow-green, frothy, foul smelling - Men are asymptomatic carriers, can sometimes have urethritis, prostatitis or UTI 3.) Pathogenesis: contact with squamous epithelium of GU tract results in destruction, neutrophil influx 4.) Diagnosis: - T. vaginalis swimming in exudate via Pap 5.) Treatment: metronidazole

Question 81

HIV. Describe treatments including MOAs

Answer 81

6.) Treatments and MOAs (intervening during virus life cycle) – Goal = reduce viral load as low as possible for as long as possible a.) Attachment/fusion - Chemokine coreceptor antagonists: prevents co-receptor interaction with gp120 - Fusion inhibitors (FIs): binds to gp41 preventing fusion b.) Reverse transcription - Nucleoside inhibitors (NRTIs): incorporates into DNA chain during provirus synthesis causing termination - Non-nucleoside inhibitors (NNRTIs): inhibits reverse transcriptase c.) Integration - Integrase inhibitors (IIs): blocks integration d.) Protein cleavage/maturation - Protease inhibitors (PIs): inibitors of viral protease leading to production of immature defective HIV virions - Combination therapies are used in standard of care (at least three ARV drugs usually from two different classes) – always 2NRTIs plus: a.) 1 NNRTI b.) 1 PI c.) 1 II

Question 82

HIV. Describe serological markers with acute to chronic infection and the diagnostic measures / testing schemes

Answer 82

5.) Serological markers, Testing/diagnosis Serology - HIV RNA = 1st marker present in plasma (as early as 10 days) - HIV-1 p24 antigen = 2nd marker present (as early as 15 days) - HIV antibody = 3rd marker Testing/diagnosis - #1: HIV1/2 antigen/antibody combo immunoassay – antigen = p24 specifically - #2: Differentiation HIV1/2 antibody immunoassays – if indeterminant, do nucleic acid testing

Question 84

HSV. Describe pathogenesis

Answer 84

3.) Pathogenesis: - Entry and replication in peripheral epithelium - Retrograde transport of HSV into sensory neurons - Latency established in ganglia - Spontaneous reactivation (d/t stress, UV, trauma, hormonal etc.) and virion production resumes - Anterograde transport to epithelium - Replication in epithelium and HSV shedding

Question 85

Predisposing factors to UTIs

Answer 85

• Obstruction of UT (d/t prostate hyperplasia for example) - Kidney surgery - Catheterization - GU malformation - Diabetes - Pregnancy - Female

Question 86

Chlamydia trachomatis. Describe diagnosis, treatment, prevention

Answer 86

4.) Diagnosis: - Cannot culture by themselves, must be with cells. Use scrapings - Iodine identifies RBs, immunofluorescence of EBs - Choice test = nucleic acid from urine or discharge 5.) Treatment: Doxycycline or macrolide, both inhibit protein synthesis. No beta-lactam as no peptidoglycan. 6.) Prevention: education about safe sex practices, no immunity conferred with previous infection, no vaccine

Question 87

Neisseria gonorrhoeae (aka the clap, the drip). Describe characteristics

Answer 87

1.) Characteristics - Gram neg aerobe diplococci, exclusively human host

Question 88

HPV. Describe pathogenesis

Answer 88

3.) Pathogenesis: - Target for primary infection = basal surface of epithelium - Migrates towards suprabasal level and undergoes replication/differentiation along this path – key to have the levels in epidermis - In CA: genome integration is the only component that occurs – no replication. Increases in E6/E7 expression seen in virus during this time. E2 (negative regulator) is decoupled from E6/7 in genome and leads to increases in their respective levels. E6 represses p53, E7 represses Rb – both push cells into S phase and proliferative replication.

Question 89

What is the best method for diagnosis of infection with chlamydia? A. culture of urethral discharge in liquid broth followed by staining B. culture of urethral scraping in liquid broth followed by staining C. culture of urethral discharge with cells followed by staining D. culture of urethral scraping with cells followed by staining

Answer 89

• D. Obligate intracellular bacterium

Question 90

Most frequent bacterial causative agents of nosocomial acquired UTIs

Answer 90

• Klebsiella, enterobacter, serratia, p. aeruginosa, enterococcus - Proteus