Microbiology: A Systems Approach, 2nd ed. Chapter 23: Infectious Diseases Affecting the Genitourinary System

23.1 The Genitourinary Tract and Its Defenses Urinary tract: removes substances from the blood, regulates certain body processes, and forms urine and transports it out of the body Includes the kidneys, ureters, bladder, and urethra Defenses Flushing action of urine Desquamation of the epithelial cells Acidity of urine Antibacterial proteins in urine Secretory IgA

Genital System Genital system: reproduction , aka the reproductive system Male reproductive system includes the testes, epididymis, vas deferens, prostate gland, scrotum, and penis Defenses: flushing action of urine Female reproductive system includes the uterus, fallopian tubes, ovaries, and vagina Defenses vary over the lifetime of the woman Childhood and after menopause: mucous is the major defense with secretory IgA antibodies During reproductive years: changes in pH

Figure 23.1

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23.2 Normal Biota of the Urinary Tract Outer region of the urethra harbors some normal biota Nonhemolytic streptococci, staphylocci, corynebacteria, and some lactobacilli Normal Biota of the Male Genital Tract Same as described for urethra, since the urethra is the terminal “tube” Normal Biota of the Female Genital Tract The vagina harbors a normal population of microbes Lactobacillusi species Candida albicans at low levels

23.3 Urinary Tract Diseases Caused by Microorganisms Urinary Tract Infections (UTIs) Urine is a good growth medium for many microorganisms Reduced urine flow or accidental introduction of bacteria into the bladder can result in cystitis If the infection also affects the kidneys it is called pyelonephritis An infection only in the urethra: urethritis

Cystitis Cystitis: sudden onset of symptoms Pain in the pubic area Frequent urges to urinate even when the bladder is empty Burning pain accompanying urination (dysuria) Cloudy urine Orange tinge to the urine (hematuria) Fever and nausea Back pain indicates kidneys may also be involved

Leptospirosis Zoonosis associated with wild animals and domesticated animals Can affect the kidneys, liver, brain, and eyes Major effects on the kidneys and is shed into the environment through animal urine Two phases Early (leptospiremic) phase Sudden high fever, chills, headache, muscle aches, conjunctivitis, and vomiting Second phase (immune phase) Milder fever, headache, Weil’s syndrome (kidney invasion, hepatic disease, jaundice, anemia, and neurological disturbances)

Figure 23.4

Urinary Schistosomiasis Schistosoma haematobium lodges in to the blood vessels of the bladder May or may not result in symptoms If symptoms occur: itchiness in the area where the worm enters the body, fever, chills, diarrhea, and cough Urinary tract symptoms occur later which may include blood in the urine and bladder obstruction

23.4 Reproductive Tract Diseases Caused by Microorganisms Many are transmitted through sexual contact, but not all are Three broad categories of sexually transmitted diseases Discharge diseases Ulcer diseases Wart diseases

Vaginitis and Vaginosis Inflammation of the vagina Vaginal itching to some degree Burning and sometimes a discharge occurs Symptoms depend on the etiologic agent

Candida albicans Normal biota living in low numbers If grows rapidly and causes a yeast infection, white vaginal discharge occurs

Figure 23.5

Gardnerella species Infection called vaginosis rather than vaginitis because inflammation in the vagina does not occur Vaginal discharge with a very fishy odor, especially fater sex Itching is common

Trichomonas vaginalis Asymptomatic infections in approximately 50% of females and males Some people experience long-term negative effects

Figure 23.7

Prostatitis Inflammation of the prostate gland Acute or chronic Pain in the pelvic area, lower back, or genital area; frequent urge to urinate; blood in the urine; and/or painful ejaculation

Discharge Diseases with Major Manifestation in the Genitourinary Tract Increase in fluid discharge in male and female reproductive tracts Includes trichomoniasis, HIV, gonorrhea, and Chlamydia infection

Gonorrhea N. gonorrhoeae is the etiologic agent- also known as the gonococcus Symptoms in the male Urethritis, painful urination and a yellowish discharge Can occasionally spread from the urethra to the prostate gland and epididymis Scar tissue in the spermatic ducts during healing can render a man infertile (rare)

Symptoms in the Female Likely that both urinary and genital tracts will be infected Mucopurulent or bloody vaginal discharge Painful urination if urethra is affected Major complications occur when the infection ascends from the vagina and cervix to higher reproductive structures Salpingitis Pelvic inflammatory disease

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Chlamydia Most common reportable infectious disease in the U.S. Majority of cases are asymptomatic Symptoms in males Inflammation of the urethra Symptoms mimicking gonorrhea Untreated infections may lead to epididymitis Symptoms in females Cervicitis Discharge Salpingitis May lead to PID

Certain strains can invade the lymphatic tissues, resulting in lymphogranuloma venereum Headache, fever, muscle aches Lymph nodes fill with granuloma cells and become enlarged and tender Babies born to mothers with infections can develop eye infections and pneumonia

Figure 23.12

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Genital Ulcer Diseases Three common infectious conditions resulting in lesions on a person’s genitals Syphilis, chancroid, and genital herpes Having one of these diseases increases the chances of infection with HIV because of the open lesions

Syphilis Three distinct clinical stages: primary, secondary, and tertiary Latent periods of varying duration also occur Transmissible during the primary and secondary stages, and the early latency period between secondary and tertiary Largely nontransmissible during late latent and tertiary stages

Primary Syphilis Appearance of a hard chancre at the site of entry of the pathogen (after an incubation period of 9 days to 3 months) Lymph nodes draining the affected region become enlarged and firm Chancre filled with spirochetes Chancre heals spontaneously in 3 to 6 weeks but by then the spirochete has moved into the circulation

Secondary Syphilis 3 weeks to 6 months after the chancre heals Many systems have been invaded Fever, headache, sore throat, followed by lymphadenopathy and a red or brown rash that breaks out on all skin surfaces Hair often falls out Lesions contain viable spirochetes and disappear spontaneously in a few weeks Major complications occur in bones, hair follicles, joints, liver, eyes, and brain

Figure 23.14

Latency and Tertiary Syphilis Highly varied latent period, can last for 20 years or longer Tertiary syphilis is rare because of the use of antibiotics Major complications occur by this stage Cardiovascular syphilis- weakens the arteries in the aortic wall Gummas develop in tissues such as the liver, skin, bone, and cartilage

Figure 23.15

Congenital Syphilis From a pregnant woman’s circulation into the placenta and fetal tissues Inhibits fetal growth Disrupts critical periods of development

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Chancroid No systemwide effects Infection usually begins as a soft papule at the point of contact Develops into a soft chancre (painful in men, but may be unnoticed in women) Inguinal lymph nodes can become swollen and tender

Genital Herpes Caused by herpes simplex viruses (HSVs) Multiple presentations No symptoms, or single or multiple vesicles on the genitalia, perineum, thigh, and buttocks Lesions from initial infection can be accompanied by malaise, anorexia, fever, and bilateral swelling and tenderness of the groin Occasionally meningitis or encephalitis can develojp After recovery from initial infection, may have recurrent episodes of lesions; generally less severe In the neonate and fetus, HSV infections are very destructive and can be fatal

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Wart Diseases Human papillomavirus (HPV) Molluscum Contagiosum Causative agents of genital warts An individual can be infected with HPV without having warts, however Molluscum Contagiosum Unclassified virus in the pox family Can take the form of skin lesions Wartlike growths on the mucous membranes or skin of the genital area

Group B Streptococcus “Colonization”- Neonatal Disease 10% to 40% of women in the U.S. are colonized asymptomatically by group B Streptococcus When these women become pregnant, about half of their infants become colonized by the bacterium during passage through the birth canal Small percentage of infected infants experience life-threatening bloodstream infections, meningitis, or pneumonia

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