Lecture 54 to 58 UGI Infection Flashcards
UGI Sx
Acute pyelonephritis
- Signs & Sx: high-grade fever, upper back and flank pain, shaking and chills, nausea, vomiting
Cystitis
- low-grade fever, pelvic pressure, lower ab discomfort, frequent, painful urination
Urethritis
- Burning w urination
- Most of the time E. coli colonize urethra to cause infections via adhesins
- Male sx: feeling of fullness, lower back pain
- Female sx: burning pain, urge to urinate
Normal microflora: Urethra
Urethra
– Lactobacilli
– Streptococci
– Coagulase-negative Staphlococci
Normal Microflora
Vagina
– More diverse, influenced by hormones
– Newborn girls colonized w/ Lactobacilli, vaginal flora becomes more diverse over time
– Lactobacilli become more prominent at puberty
Lactobacilli
In addition to URT: – mouth, intestines, stomach
Gram + rods, non-spore forming
Facultative or strict anaerobes, produce lactic acid
Rarely cause UTIs
Gonorrhea
Pathogen: N. gonorrhoeae, Gram -ve diplococci
- Fastidious
- oxidase +
- encapsulated
- outer surface w/ multiple antigens
- facultative intracell in PMN
Etiopath:
- Attachment to columnar epithelium of distal urethra or cervix
- Pili – unusual, specialized mechanism of antigenic variation by DNA rearrangement
- Opa
- por protein
- LOS– induces TNF-alpha in some cells
- iron-binding proteins
- co-infection w chlamydia
Sx:
- purulent white urethral discharge,
- cervicitis
- lower ab pain in women,
- polyarthritis (asymmetric)
- neonatal conjunctivitis.
- maybe asx
Dx
- Growth on Chocolate agarm modified Thayer-Martin aka VPN agar which includes antibiotics to differentiate bw pathogenic Neisseria and non-path Neisseria/bacteria.
- Pt w MAC complex (C5 to C9) susceptible to infections
C&C:
- PID
- ectopic preg
- peritonitis from PID spread (Fitz-Hugh-Curtis)
- Violin string adhesions form to capsule of liver
Chlamydia
- Pathogen: C. trachomatis
- visualized thru Giemsa stain
- most commonly reported notifiable disease (US)
Divided into 3 biovars (biological variants), then subdivided into serovars (~serotypes, differ in their major outer membrane proteins, assoc. w/different diseases)
- agent of trachoma (A, B, Ba, C):
* leading cause of blindness worldwide
* hand to eye transmission
- agent of trachoma (A, B, Ba, C):
- D to K: STI
* conjunctivitis,
* infant pneumonia,
* urogenital disease -> PID -> ectopic pregnancies
- D to K: STI
- lymphogranuloma venereum (LGV1, -2, -3): tender inguinal LN
Chlamydia lifecyle
- EB Enters -> infectious
- RB replicates -> inclusion bodies seen under microscope
- Receptors for EBs: restricted to certain epithelial cells
- – mucous membranes of the urethra
- – endocervix, endometrium, fallopian tubes
- – anorectum
- – respiratory tract and conjunctivae
- Infection does not confer long-lasting immunity
Sx (similar to Gonorrhoea):
- Adults: urethral purulent watery discharge, cervicitis and lower ab pain in women
- Neonatal: conjunctivitis & pneumonia
- Extensive bilateral, tender inguinal & femoral lymphadenopathy
- Groove sign: linear fibrotic depressions parallel to theinguinal ligament, bordered above and below by enlarged and matted LN and covered by adherent, erythematous skin, seen in 10-20% of LGV–Chlamydia trachomatis
- No fever, no urethritis
Etiopath
- Primary infection
- Genital ulcer or a mucosal inflammatory reaction at the site of inoculation
- The incubation period is 3 to 12 days
- These lesions spontaneously heal within a few days.
- Secondary infection
- 2-6 weeks later and is related to local direct extension of the infection to regional
- lymph nodes (ie, inguinal and/or femoral nodes)
- Extensive painful lymphadenitis
Dx: NAAT using urine or swab specimen
C&C:
- PID in 40% of untreated women
- epididymitis & urethritis
- Reiter’s syndrome: uveitis, reactive arthritis, urethritis
Rx:
- Macroglide
- Doxycylcin
- Ceftriaxone due to co-infection w N. gonorrohea
Syphillis
Syphillis
- Pathogen: Treponema pallidum
Thin, tightly coiled spirochetes w/pointed straight ends
- 3 flagella @ each end: MOTILE
- Replication slow – no in vitro culture
- Obligate human pathogen
- Unusual outer membrane
- (no LPS, no porins)
- Transmission: sex, blood transfusions, transplacental, IV drug use
- highly infectious (transmission via direct contact with 10 or 20 lesions), genital, ulcerative disease that is easily curable in its early P&S stages
- congenital syphilis
- assoc w crack cocaine use
Etiopath: patient’s immune response to infection
- Outer membrane proteins promote adherence
- Hyaluronidase may facilitate perivascular infiltration: “spreading factor”
- Coating of fibronectin may protect against phagocytosis
- 1o enters subepithelial tissues via skin breach
- Slow replication, not a wide range of environmental conditions tolerated: Fastidious
- Endarteritis (arch or ascending aorta) and granulomas
- Lesion heals but bacteria disseminate via lymph nodes and blood stream (latency poorly understood)
- 2o: evasion of immune system, poorly understood
- 3o: diffuse chronic inflammation, CNS involvement
Sx: Hard anogenital ulcers (chancre), painless, mild erythema; inguinal swelling; generalized skin rash
- Primary: hard, painless but sensitive genital ulcer develops 9-90 days post-infection (pi)
- Lesions often have thin, greyish crust (easily removed -> crater w/ viscous fluid containing living T. pallidum cells
- Secondary: generalized maculopapular rash apparent on hands and sole of feet + multiple symptoms indicative of systemic infection.
- Condylomata Lata: cutaneous lesion, Copper penny spots
- Alopecia
- Tertiary: (15-20 yrs pi) diffuse chronic inflammation
- neurosyphilis (damage to CNS including progressive dementia, meningitis, hallucinations, etc.); affecting posterior columns -> tabes dorsalis -> ataxia & decr vibratory sensation
- cardiovascular effects such as aortic aneurysm
- Gumma formation w firm necrotic centres: granulomatous inflammation in CNS
- Argyll-Robertson pupils: non-reactive to light but accomodate
- hypersensitive granulomatous reaction
- Can be destructive to viscera or mucocutaneous areas
Dx:
- Definitive Dx: Darkfield Microscopy for early syph: examine exudate from the lesion
- PCR for T. pallidum
- Presumptive Dx: Screening consisting of Serology/immuno tests
- non-treponemal tests:
- VDRL: detects anti-cardiolipin Ab visualised by flocculation
- RPR: Rapid Plasma Reagin detecting non-specific Ab
- Note: False +ve in non-treponemal Serological Ab testing in cases of autoimmune diseases and viral infections
- Syphillis has a latent period
- Treponemal tests: CONFIRMATORY
- FT-ABS (Direct fluorescent Ab test)
- TP-PA particle agglutination
- non-treponemal tests:
- Rx: Benzathine/penicillin (IM) even if Pt is allergic (desensitize the Pt)
- Control: Syph + Pt should be tested for HIV infection
Congenital syphillis
- Sx: late-staged
- Diffuse rase all over body
- stromal haze due to syphillitc interstitial keratitis (IK)
- saddle nose
- Hutchison’s teeth & Mulberry teeth: Babies with this have teeth that are smaller and more widely spaced than normal and which have notches on their biting surfaces.
- Deafness
- Sabre shins: anterior tibial bowing
Rx for all syphillis:
- penicillin
- Jarisch-Herxheimer rxn to confirm response to penicillin rx: fever & chills
Chancroid
- Pathogen: H. ducreyi
- Fastidious
- Gram – anaerobic rods (sometimes called “coccobacilli”)
- Pleomorphic
-
Epi:
- predominant in tropics
- sporadic in N. America
- infection incr likelihood of HIV
-
Etiopath:
- Apparent extracellular pathogen that resists phagocytosis
- Virulence factors include:
– an outer membrane serum resistance protein
– two toxins: cytolethal distending toxin (CDT) and hemolysin, both of which contribute to tissue destruction
- Sx: painful SOFT genital ulcers, mildly indurated, strong erythema w inguinal swelling (bubo) in majority of cases, penis, post. vaginal wall.
-
Dx:
- Definitive dx: special culture (difficult) & direct microscopic exam (Gram stain)
- Exclude T. pallidum and HHV-1 &-2
Bacterial Vaginosis (BV)
Bacterial Vaginosis (BV)
- Normal balance of bacteria in vagina is disrupted - replaced by certain overgrowth
- Most women report no signs / symptoms
- BV: most common vaginal infection in childbearing aged women (sexual activity?)
- Having BV can increase HIV transmission
- Common pathogen: Gardnerella
- Gram variable
Sx
- sometimes accompanied by discharge unpleasant fishy odor, may be thin, white or gray
- pain, itching, or burning outside vagina
Dx
- Examining the vaginal discharge under the microscope can help distinguish BV from Candidiasis and Trichomonas
- A sign of BV: unusual vaginal cell called a Clue cell (stippled due to bacteria covering epithelial cell)
- Women with BV (polymicrobial) have fewer than normal vaginal lactobacilli
- Vaginal pH > 4.5 can be suggestive of BV
- KOH whiff test
Rx: metronidazole
Granuloma inguinate or Donovanosis
- pathogen: Klebsiella (Calymmatobacterium) granulomatis
- Sx: nodular swellings and ulcerative lesions of inguinal and anogenital areas
Klebsiella (Sketchy micro)
- encapsulated
- non-motile
- urease +
- Triple A: alcoholics, abscess, aspiration
- Sx: red currant jelly sputum
- Dx: cavitary lesion on CXR (resembes Tb)
- Side note: Painful ulcers
- chancroid
- HHV-1 or 2
- HPV
- Donovanosis/Granuloma inguinate *
Trichomoniasis
- pathogen: Trichomonas vaginalis protozoa
- parasite w 4 flagella & short undulating membrane responsible for motility
- Transmission:
Vagina: most common site of infection in women, urethra: most common site in men
Sexual intercourse is primary mode of transmission; fomite transmission possible
-
Sx: Asx mostly;
- profuse, frothy gray or yellow-green vaginal discharge
- Cervix w bubbles & strawberry appearance
Candidiasis
- pathogen: C. albicans
- Oval, yeastlike forms
- 1o site of colonization is GI tract
-
Sx:
- thick curd-like white vaginal discharge; smells like bread
- vulval itching or burning,
- pH<4.5
- 2o oral pseudomembranous candidiasis
- diaper rash
- chronic mucocutaneous candiasis
UPEC
Uropathogenic E. coli -> Primary cause of UTI
Common E. coli features (repeated from GIT)
- encapsulated
- Catalase +
- Green colonies on EMB agar
- Lactose fermenter -> pink colonies on Mac agar
- *does ferment Sorbitol *
Key virulence features:
- Type I (cystitis)
- P pili (pyelonephritis)
- Fimbriae
Additional:
• α-hemolysin
• Siderophore
• PAI
Staph saprophyticus & epidermidis
- Cause of UTIs (usually young, sexually active women)
- Infrequent asymptomatic colonizer of UT
- Staph epidermidis can cause infection in Pt w foley catheters causing fevers, chills, diffuse ab tenderness, rebound tenderness -> peritonitis
- Shows seasonality (tends to occur in summer)
- uropathogenicity due to:
- novel cell wall-anchored adhesin
- urease +
Proteus mirabilis
- Urease +
- swarming motility when plated
- fishy odour
Virulence factors:
• Proteases: induces renal stones
• Haemolysins
• Biofilmformation
• Urease production: creates alkaline env for struvite stone
Sx:
- Urine -> smells like ammonia
- UTI
- Urease -> alkaline -> urine struvite crystals -> renal stones -> staghorn calculi -> toxic to kidneys
Rx: Sulfonamides
HHV-1 &-2
Etiopath
HHV-1 and -2 can initially infect and replicate in mucoepithelial cells – lytic (most cells: Cowdry type A inclusion bodies, syncytia)
– persistent (lymphocytes and macrophages)
– latent infections (neurons); Viral re-activation due to stress, hormones, UV radiation
Virus blocks effects of interferon, prevents CD8 T-cell recognition of infected cells, escapes antibody neutralization and clearance by going into “hiding” during latent infection
Dx
Sample from ulcer -> PCR or cell culture
Serologic tests
Rx
no cure but Acyclovir used for 1st occurence (Guanosine analogue)
HPV
Sx
Condylomata acuminata (genital warts)
HPV 6 & 11 responsible >90% of anogenital warts
Complications
HPV poses a greater risk in contracting cancer than smoking or alcohol
HPV16 present in the tumors of 72% of cancer patients
- Cervical cancer
- Oral cancer
