Presentation on theme: "Ch 26 Microbial Diseases of the Urinary and Reproductive Systems."— Presentation transcript:
1 Ch 26Microbial Diseases of the Urinary and Reproductive Systems
2 LEARNING OBJECTIVESDescribe the normal microbiota of the upper urinary tract, the male urethra, and the female urethra and vagina.Describe modes of transmission for urinary and reproductive system infections.List the microorganisms that cause cystitis and pyelonephritis. Name the predisposing factors for these diseases.List the causative agents, symptoms, methods of diagnosis, and treatments for gonorrhea, chlamydia, PID, and syphilis.List reproductive system diseases that can cause congenital and neonatal infections, and explain how these infections can be prevented.Discuss genital herpes, genital warts, candidiasis, and trichomoniasis.
3 Normal Microbiota Urinary bladder and upper urinary tract are sterile Women: Flora influenced by estrogen. Lactobacilli dominate vaginal microbiota during reproductive yearsMen: urethra normally sterile>1,000 bacteria/ml or 100 coliforms/ml of urine indicates infectionWomen – flora influenced by estrogen. Estrogen causes glycogen production converted to lactic acid by Lactobacillus Lower pH inhibits growth of potential pathogens (normal flora is acid tolerant)
4 Cystitis Common in females. (Symptoms?) Contributing factors: Microorganisms at the opening of the urethra and along the length of the urethracareless personal hygienesexual intercourseMost common etiologiesE. coliS. saprophyticusMay also be caused by Proteus, Klebsiella, Enterococcus, PseudomonasAntibiotic-sensitivity tests may be required before treatment.Many nosocomial cases (how?)Bacteria can ascend to the kidney ureteritis pyelonephritis. (75% caused by E. coli)
6 Sexually Transmitted Diseases (STDs) Most diseases of reproductive system are STDs (15 million new cases each year)8 billion dollars a year to control STDs> 30 different types of STDs (bacterial, viral, parasitic)Highly effective prevention (?)
7 Gonorrhea (“Clap”) N. gonorrhoeae (G, dipplococci), reportable Attaches to mucosal cells of oral-pharyngeal area, genitals, eyes, and rectum by means of fimbriae.Males usually symptomatic (painful urination and pus discharge). Blockage of the urethra and sterility are complications of untreated cases.Females may be asymptomatic unless the infection spreads to the uterus and uterine tubes (PID).If left untreated, may result in endocarditis, meningitis, arthritis, ophthalmia neonatorumDiagnosed by ELISA or PCR.Antibiotic resistance increasing (R-plasmids)~ 350’000 cases / year in US – only human reservoirNo immunity build up / no vaccination
9 Nongonococcal Urethritis (NGU) - Chlamydia Chlamydia trachomatis, obligate intracellular bacteriumMost common STD in US, ~ 4 mio cases / year50% of males asymptomatic75% of females asymptomatic – however, PID possible!Chlamydial ophthalmia and/or pneumonia in newbornDiagnosis is based on the detection of chlamydial DNA in urineAnnual screening tests recommended for sexually active women < 25 yTo help prevent the serious consequences of chlamydia, screening at least annually for chlamydia is recommended for all sexually active women age 25 years and younger. An annual screening test also is recommended for older women with risk factors for chlamydia (a new sex partner or multiple sex partners). All pregnant women should have a screening test for chlamydia.
10 Syphilis Treponema pallidum (spirochete) Has not been cultured in vitro – can be grown in cell culturesTransmitted by direct contact – can invade intact mucous membranes or penetrate through breaks in the skinNo animal reservoirThe Great ImitatorThree stagesPrimary: hard chancre (painless) at site of infectionSecondary: flu-like symptoms, rashesLatent (possible symptoms of 2nd stage)Tertiary: gummas in skin and internal organsCongenital: Neurological damagePrimary and secondary stages treated with penicillin
11 Secondary syphilis: + wide spread rash Lesions can mimic almost anything. Often patient feels poorly and has flu like symptoms+ wide spread rashLesion fluid still highly infectious!Can last weeks to months.
12 Tertiary Syphilis Latent for up to 30 years, then Neurosyphilis Cardiovascular syphilisAortic aneurysmsGummatous syphilis“Gumma”becomes apparent after years of untreated infection (can appear anywhere)
13 Treatment successful in all stages, but damage done is irreversible Congenital syphilis – T. pallidum crosses placenta Hutchinson's triad in 63% of cases: Hutchinson's teeth (notched incisors), keratitis and deafnessDiagnosis: T. pallidum cannot be cultured Darkfield microscopy and serological assaysTreatment successful in all stages, but damage done is irreversibleHutchinson's triad, which consists of Hutchinson's teeth (notched incisors), keratitis and deafness and occurs in 63% of cases
14 Genital HerpesHerpes simplex viruses (HSV-1 and HSV-2) cause genital herpesSymptoms: painful urination, genital irritation, and fluid-filled vesiclesNeonatal herpes:contracted during fetal development or birth. Can result in neurological damage or infant fatalitiesVirus might enter latent stage in nerve cells (Life-long infection). Vesicle recurrences following trauma, stress, and hormonal changesHighly transmittable – subclinical shedding rate can be as high as in symptomatic infection - also neonatal herpesSuppression: Acyclovir or valacyclovirNo animal reservoirs
16 Genital Warts Human papillomaviruses cause warts Some human papillomaviruses that cause genital warts have been associated with cancer of the cervix or penis (HPV 16 and 18)DNA test is needed to detect cancer-causing strains.Fomite transmission possibleTreatment: Imiquimod to stimulate interferonImportance of pap smearVaccination against HPV strainsDr. PapanicolaouExfoliative cytology of the vagina and cervix
17 In a pap smear, a vaginal speculum is used In a pap smear, a vaginal speculum is used. A sample of cells is removed with a cotton-tipped swab or tiny wooden spatula and smeared onto a glass slide for examination under a microscope
19 CandidiasisCandida albicans grows on mucosa of mouth, intestinal tract, and genitourinary tract (NGU in males and vulvovaginal candidiasis, or yeast infection, in females)Vulvovaginal candidiasis characterized by lesions that produce itching and irritationPredisposing factors are pregnancy, diabetes, tumors, and broad-spectrum antibacterial chemotherapyDiagnosis is based on observation of the fungus and its isolation from lesionsTreatment: Clotrimazole or miconazole.
20 TrichomoniasisTrichomonas vaginalis causes trichomoniasis when the pH of the vagina increasesFrequently part of normal biota – men usually asymptomatic carriers (reservoir). T. vaginalis found in semen or urine of male carriersDiagnosis is based on observation of the protozoa in purulent discharges from the site of infection.Vaginal infection causes irritation and profuse greenish-yellow discharge with foul odorDiagnosis is by microscopic identification of protozoanNo animal reservoirs – no fomite transmissionTreatment: Metronidazole.