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

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
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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
Figure 23.2
Figure 23.3
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
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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
Figure 23.8
Figure 23.9
Figure 23.10
Figure 23.11
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
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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
Figure 23.13
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
Figure 23.16
Figure 23.17
Figure 23.18
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
Figure 23.19
Figure 23.20
Figure 23.21
Figure 23.22
Figure 23.23
Wart Diseases
• Human papillomavirus (HPV)
– 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
Figure 23.24a
Figure 23.24b