Genitourinary Tract Infections Flashcards
Normal flora of the genitourinary system
Lactobacillus
Staphylococcus
Haemophilus
Cystitis
(Bacterial agent for genitourinary tract infections)
E. coli: most often responsible
Virulence mechanism: pili
Can progress to plelonephritis
Epidemiology: short urethra, intercourse, birth control devices. enlarged prostate (benign prostatic hypertrophy), catheterization, paraplegia
Treatment: increase fluid intake, cranberries have lectin that mimics attachment site of pili to prevent attachment to lining of bladder, void after intercourse
Toxic Shock Syndrome
(Bacterial agent for genitourinary tract infections)
Caused by strains of S. aureus that encode TSST-1 toxin and exotoxins that are SUPERANTIGENS- activate T helper cells non-specifically by binding to MHC class II/TCR molecules outside the peptide binding grove. Cause toxic overproduction of cytokines.
Signs and symptoms: sudden fever, headache, vomiting, diarrhea, sunburn-like rash, confusion. Sudden drop in BP leads to death
Epidemiology: first associated with menstruating women and tampon use. also associated with surgical wound infections.
Gonorrhea
[Sexually transmitted disease]
Causative agent: Neisseria gonorrhoeae- gram negative diplococci. Found on and within leukocytes in urethral pus.
Virulence:
Outer membrane proteins responsible for binding
Porin proteins that allow for escape from phagosomes
Capsule made of human sialic acid
IgA protease
Special lipopolysaccharide- lipoOLIGOsaccharide (LOS) which looks like the surface of RBCs
Pili responsible for antigenic variation- has gene cassettes that the bacteria use to switch to a different pili/LOS structure; antigenic variation allows bacteria to outpace immune system-lack of immunity following infection (no long term antibody protection)
Increasing antibiotic resistance
Susceptible to cold and drying
Symptoms:
Asymptomatic infections occur in both sexes
Males: mainly self-limiting, urethritis, drip. Untreated disease may result in scarring that leads to UTI.
Females: Untreated infections results in pelvic inflammatory disease (PID)-infection progresses through uterus into fallopian tubes. Can attack liver or other abdominal organs.
Repeat infections cause scarring that can lead to urinary tract infections, infertility and ectopic pregnancies (in women)
May cause ophthalmia neonatorum in infants. A child is infected at birth. MAy causes blindness unless treated with antibiotic that can eliminate infection (antibiotic resistance). NOT a TORCH organism- can’t pass through the placenta.
AMC (abstinence, BLANK*, condoms)
SuperBug- strains present that are resistant to all usable antibiotics.
Chlamydia
Causative agent: Chlamyia trachomatis, gram negative, obligate intracellular organism with no peptidoglycan
Lifecycle: Infectious elementary body attaches –> Once inside the cell becomes a reticulate body (not infectious) –> cell wall inhibits formation of phagolysosome and can live in phagocytes
Signs and Symptoms: Inflammation and cell-mediated immune response creates most symptoms
In males, mimics symptoms of gonorrhea: urethritis, gray-white discharge, scarring of urethra, painful testes
In females may cause sterility and PID, but completely asymptomatic. Other symptoms may include increased vaginal discharge, painful urination
Chlamydial ophthalmia neonatorum- often developed in newborns with infected mothers during passage through birth canal
Treatment: AMC (abstinence, monogamy, condoms)
Spread in clusters with other STDs
(Can be transmitted non-sexually in swimming pools)
Syphilis
Caused by Treponema pallidum- slender motile spirochete, no gram identity
Stages of syphilis:
Primary-Chancre: resolves in 4-6 weeks, may not be more than a pimple as a lesion; lesion is infectious
Secondary: organisms spread throughout body, immune complexes form. Stage can last for weeks to months. Infectious lesions found on skin and mucous membranes.
Latent: no symptoms
Tertiary: gummas (lesions), hypersensitivity reaction. Extent of disease depends on location of persistent infections. Lesions no longer infectious. Disease depends on where the organism is localized
Congenital Syphilis (TORCH): No problem if the bacteria is detected and treated before the fourth month. Risk to fetus depends on the stage in infection in mother. May develop secondary syphilis, which is fatal in weeks, or characteristic deformities
Transmission: Low ID50, primarily sexually transmitted due to sensitivity of organism by drying and chilling, can penetrate abrasions in skin or through mucous membranes, kissing, transplacental
Treatment: PEnicillin, AMC
Targeted for eradication because there are no animal reservoirs
HSVI (Oral Herpes) & HSV11 (Genital Herpes)
(Viral agents)
Both are members of the herpesvirus family, enveloped DNA virus, spread by close contact, body fluids, and can be transmitted while asymptomatic
Oral Herpes Simplex Type I
Symptoms: Fever, throat pain and ulceration on mouth and lips but may also cause asymptomatic infections
Becomes latent in nerves
Can be spread on fomites, saliva, kissing, close contact
Genital Herpes Simplex Type II
Transmitted primarily by sexual contact
Symptoms: painful urination, genital irritation, fluid-filled vesicles
Virus hides in nerves, becomes latent, reactivation
Disseminated disease of newborn- permanent sequelae due to neurological damage (TORCH), most chance for disease if mother has primary infection near the time of delivery, prevent by cesarean section delivery
High incidence of cervical cancer associated with infection
Type I and Type II can be interchangeable
*Condoms don’t completely provide protection
Human Papaloma Virus (HPV)
Causative agent of all warts including genital warts. Over 100 different strains.
Some strains cause plantars warts, and only some strains of HPV will cause genital warts. A few of these strains that cause genital warts (16&18) are highly associated with cervical cancer (DNA virus)
Most commonly acquired sexually transmitted disease
Symptoms: may be asymptomatic, warts develop on external and internal genitalia and anus, warts may develop in mouth from oral sex, may grow large enough to block birth canal or obstruct the urethra
Transmission: sexually transmitted, a single exposure transfers disease 60% of the time, asymptomatic carriers transmit disease
Treatment: Vaccine, AMC- condoms do not completely provide protection, yearly pap test, wart removal does not cure infection, normal immune defenses eliminate infection in most within 2 years
Trichomoniasis
(Protozoan agent)
Causative agent: Trichomonas vaginalis- protozoan lacking mitochondria, has unique organelles that create energy by producing hydrogen gas
Signs and Symptoms: frothy, malodorous, yellowish-green discharge, itching of the vulva and inner thighs, itching burning of the vagina with painful urination
Males are predominantly asymptomatic carriers
Transmission: primarily sexually transmitted, may be spread by on moist towels or bathtubs
Treatment: AMC, growing resistance to anti-protozoan drugs
