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Lecture 18: Microbial diseases of the urinary and reproductive system Edith Porter, M.D. MICR 201 Microbiology for Health Related Sciences. Lecture outline. Structure & function and normal microbiota of the urinary and reproductive system Ports of entry Diseases of the urinary system
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Lecture 18: Microbial diseases of the urinary and reproductive system Edith Porter, M.D. MICR 201 Microbiology for Health Related Sciences
Lecture outline • Structure & function and normal microbiota of the urinary and reproductive system • Ports of entry • Diseases of the urinary system • Bacterial • Diseases of the reproductive system • Bacterial • Viral • Fungal • Protozoan • TORCH
Female reproductive organs Note the short urethra and proximity to anus
Normal microbiota • Urinary bladder and upper urinary and reproductive tract sterile • Urethral opening colonized with skin flora (mainly gram+ bacteria) and in men, Mycobacterium smegmatis • Lactobacilli predominant in the vagina • Urine is normally sterile but can be contaminated by the microbiota of the urethral opening
Ports of entry for microbial diseases of the urinary and reproductive systems • Microbes usually enter the urinary system through the urethra • Microbes usually enter the reproductive system through the vagina (females) or urethra (males)
Cystitis • Urinary bladder infection • Dysuria: difficult, painful and imperative urination • Usually caused by • E. coli • S. saprophyticus(in female) • May also be caused by • Associated with kidney stones: Proteus • Nosocomial: Klebsiella, Pseudomonas, Enterococcusfaecalis • Antibiotic-sensitivity tests should guide treatment
Diagnosis of cystitis • Clean catch urine (midstream urine after urethral opening had been cleansed) • Refrigerate until urine is processed, because there is typically some contaminating normal flora present (< 10,000/ml) • In general > 100,000 bacteria/ml = infection • Single organism
Pyelonephritis • If cystitis left untreated pyelonephritis may follow • Fever, flank or back pain • 75% caused by E. coli • In the elderly danger of sepsis • i.v. antibiotics Diseased kidney Normal kidney
Sexually transmitted infections (STIs) • Major public health impact • In the US ~15 Mio new cases/year (or ~30 new infections /min) • Female often without major symptoms • Major cause of infertility • Prevented by (properly used) condoms and vaccination (genital warts)
Most common causes of STI • Most common bacterial STIs • Neisseriagonorrhoeae(gonorrhoea) • Chlamydia trachomatis(non-gonococcocalurethritis, NGU) • Treponemapallidum(Syphilis) • Treated with antibiotics • Most common viral STIs • Herpes simplex 2 (genital herpes) • Papilloma virus (genital warts, cervical cancer) • Other STIs • Fungal: candidiasis • Protozoan: trichomonas
Neisseriagonorrhoeae • Gram negative diplococci • Attaches to columnar epithelial cells via pili • Oropharyngeal, eyes, rectum, urethra, opening of cervix, external genitals of pre-pubertal females • Antigenic variation of pilin and expression of opa which blocks T cells and immunological memory • Typically urethritis, cervicitis • Females may be asymptomatic; males have painful urination and pus discharge • Old disease (name coined in A.D. 150 “flow of semen”) • In rare untreated cases systemic spread and joint infection • Arthritis (one knee joint only) • Upon birth • Ophthalmianeonatorum
Gonorrhea: discharge and pus Neutrophil
Nongonococcalurethritis • Chlamydia trachomatis • May be transmitted to newborn's eyes • Painful urination and watery discharge • Mycoplasmahominis • Ureaplasmaurealyticum Watery discharge in CT
Chlamydia trachomatis • Infects epithelial cells • Special life cycle with 2 life forms • Elementary body, resistant and infectious • Reticulate body, sensitive and proliferating • Infection must be treated through 2 life cycles of CT
The two life forms of Chlamydia 48 h -72 h
Pathogenic factors of C. trachomatis • Contribute to intracellular survival and proliferation • In part secreted via Type III secretion apparatus • Effect actin rearrangement and endocytic uptake of CT • CT inserts proteins in inclusion (endosome) membrane that prevent fusion of host lysosomes • CT releases proteins into the cytoplasma that interfere with NFkB signal transduction, a key pathway of the acute inflammatory and innate immune response
Pelvic inflammatory disease • N. gonorrhoeae • C. trachomatis • Scarring can block uterine tubes • Chronic abdominal pain • Infertility and ectopic pregnancies Laparascopic image showing acute inflammation of right tube, fimbriae and ovaries
Diagnosis of gonorrhoeaandNGU • Nulceic acid amplification tests most accurate • PCR based • Antigen detection (ELISA) • Culture (gonorrhoea > NGU)
Syphilis • Treponemapallidum, gram negative spirochete • Invades mucosa or enters through skin breaks
Three stages of syphilis • 1. stage: acute ulcer (painless, hard), highly infectious • 2. stage: systemic spread into skin, highly infectious • 3. stage: gumma, immunological response in tissue, neurosyphilis,
Diagnosis of syphilis • Direct diagnosis: • Darkfield microscopic identification of bacteria • Staining with fluorescent-labeled, monoclonal antibodies • Indirect serological diagnosis • Reagins: antibodies against conserved structures on Treponema • Specific antibodies
Genital herpes • Herpes simplex virus 2 (Human herpesvirus2 or HHV2) • Burning sensation followed by development of fluid filled vesicles • Sometimes non-symptomatic • Neonatal herpes transmitted to fetus or newborn • Spontaneous abortion of severe fetal damage • Virus enters latency with recurrence
Genital herpes: recurrent, very painful vesicles “Unlike love herpes is forever”
Genital warts • Human papillomaviruses • HPV16 causes cervical cancer and cancer of the penis • DNA test to detect cancer-causing strains • Vaccination against HPV strains
Candidiasis • Candida albicans • Severe itching and thick yellow cheesy discharge • Result from opportunistic overgrowth • Increased during pregnancy and in diabetic women
Trichomoniasis • Trichomonasvaginalis • Protozoan • Found in semen or urine of male carriers • Vaginal infection causes irritation and profuse discharge (foul smelling, frothy) • Diagnosis by microscopic identification of protozoan
Intrauterine Infections: TORCH • Toxoplasma • Other • Treponemapallidum • Listeriamonocytogenes • Rubella • Cytomegalovirus • Herpes simplex
Important to remember • Urethra opening (gram+ bacteria, Mycobacterium smegmatis) and vagina (Lactobacillus spec.) are populated by normal microbiota. • The female urethra is much shorter than the male. This and close vicinity to anus makes women more prone for urinary tract infections. • Diseases of the urinary system are mainly of bacterial origin. In out patients: E. coli, S. saprophyticus; associated with kidney stones: Proteus; noscomial: Enterococcusfaecalis, Klebsiella, Enterobacter, Pseudomonas. • Females often have less symptoms than men during an STI. • Infertility is a frequent complication after STI. • Diseases of the reproductive system of bacterial origin:Neisseriagonorrhoeae, Chlamydia trachomatis, Treponemapallidum; of viral: Herpes simplex 2, Papilloma virus; of fungal: Candidaalbicans; of protozoan: Trichomonasvaginalis • Birth defects are in particular associated with TORCH (Toxoplasma, Rubella , Cytomegalovirus, Herpes simplex).
Check your understanding 1) Cystitis is most often caused by A) Escherichia coli. B) Leptospirainterrogans. C) Candida albicans. D) Neisseriagonorrhoeae. E) Pseudomonas aeruginosa. 2) Which of the following is often diagnosed by detection of antibodies against the causative agent? A) Nongonococcalurethritis B) Gonorrhea C) Syphilis D) Cystitis E) Candidiasis 3) Normal microbiota of the adult vagina consist primarily of A) Lactobacillus. B) Streptococcus. C) Mycobacterium. D) Neisseria. E) Candida.