Biology & Life Sciences Chapter 24 Homework The two kidneys filter wastes from the blood

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CHAPTER

Microbial Diseases of the Urinary

and Reproductive Systems

Chapter Outline

Structures of the Urinary and Reproductive Systems (pp. 748–750)

Structures of the Urinary System

Structures of the Reproductive Systems

Microbiome of the Urinary and Reproductive Systems

Bacterial Diseases of the Urinary System (pp. 750–751)

Bacterial Urinary Tract Infection

Leptospirosis

Nonvenereal Diseases of the Reproductive Systems (pp. 751–757)

Staphylococcal Toxic Shock Syndrome

Bacterial Vaginosis

Vaginal Candidiasis

Sexually Transmitted Infections (STIs) and Diseases (STDs) (pp. 757–760)

Bacterial STDs (pp. 760–766)

Gonorrhea

Syphilis

Chlamydial Infections

Viral STDs (pp. 766–769)

Genital Herpes

Genital Warts

Protozoan STDs (pp. 769–770)

Instructor’s Manual for Microbiology with Diseases by Body System, 5e

Chapter Summary

Structures of the Urinary and Reproductive Systems

(pp. 748–750)

The urinary and reproductive systems in females are anatomically distinct. In males, the two

systems share some structures.

Structures of the Urinary System

The two kidneys filter wastes from the blood, excreting them as urine. The kidneys are connect-

ed by ureters to the urinary bladder, which stores urine until it is excreted via the urethra.

Each kidney has three distinct regions; the tough outer renal capsule, the renal cortex, and

the inner renal medulla. Renal pyramids make up most of the medulla. The pelvis collects urine

from the pyramids and empties into the ureter. Each pyramid is composed of millions of neph-

Structures of the Reproductive Systems

The female reproductive system includes two ovaries, which produce haploid ova, one of which

is released monthly. Ova are swept through either of two uterine tubes (Fallopian tubes) toward

the uterus (womb), the lining of which is thickened after ovulation in preparation for pregnancy.

The uterus ends at the cervix, which opens into the mucous-membrane-lined vagina (birth ca-

nal). The external genitalia include the clitoris, two sets of labia (lips), and the opening of the

vagina.

Fertilization occurs when a sperm cell fuses with an ovum and the resulting diploid zygote

develops into an embryo that implants in the uterine wall and forms a placenta. A fully devel-

pathogens.

Male reproductive organs include two testes (testicles) located in an external pouch called the

scrotum, a system of ducts, accessory glands, and the penis. Testes produce sperm cells that are

stored in the epididymis and pass through the ductus deferens into the urethra, which passes

Microbiome of the Urinary and Reproductive Systems

The urethra normally supports the growth of some microbiota, chiefly avirulent species of Lac-

tobacillus, Staphylococcus, and Streptococcus. In both males and females, the rest of the urinary

organs and the urine in them are sterile due to the normally acidic pH of urine and the flushing

Chapter 24 Microbial Diseases of the Urinary and Reproductive Systems

Bacterial Diseases of the Urinary System (pp. 750–751)

Both urinary tract infections (UTIs) and systemic bacterial diseases can affect the health of

the urinary system. UTIs primarily affect females.

Bacterial Urinary Tract Infections

Invading bacteria may trigger inflammation in the urethra (urethritis), urinary bladder (cystitis),

prostate (prostatitis), or kidneys (pyelonephritis). Mild UTIs may produce no symptoms or only

a slight fever, but most often UTIs involve frequent, urgent, and painful urination, called dysu-

Leptospirosis

Leptospirosis is a zoonosis, that is, a disease primarily seen in animals that spreads to humans

through contact with urine or contaminated bodies of water. The causative agent enters the body

through breaks in the skin or mucous membranes and spreads to the urinary system from the

Streptococcal Acute Glomerulonephritis

When some strains of group A Streptococcus infect adults, antibody-antigen complexes can ac-

cumulate in the glomeruli of the kidneys to trigger streptococcal acute glomerulonephritis,

Instructor’s Manual for Microbiology with Diseases by Body System, 5e

Nonvenereal Diseases of the Reproductive Systems

(pp. 751–757)

Staphylococcal Toxic Shock Syndrome

Sudden-onset fever, chills, vomiting, diarrhea, extremely low blood pressure, mental confusion,

and a severe red rash characterize staphylococcal toxic shock syndrome (TSS). Untreated TSS is

50% fatal. Certain strains of Staphylococcus aureus cause the condition, most notably in men-

Bacterial Vaginosis

Bacteria infecting the warm, moist vaginal lining cause bacterial vaginosis. The condition is

characterized by a white discharge with a “fishy” odor. Some itching or irritation may also oc-

cur. Up to half of cases are asymptomatic. Infection results when the normal lactobacilli of the

vagina are replaced with a large number of facultatively or obligate anaerobic bacteria such as

Vaginal Candidiasis

Candidiasis describes any of a variety of opportunistic yeast infections and diseases caused by

various species of the genus Candida. Vaginal candidiasis manifests as white mucoid colonies

Sexually Transmitted Infections (STIs) and Diseases (STDs) (pp.

757–760)

Sexual activity can transmit potential pathogens, resulting in sexually transmitted infections

(STIs). Disease resulting from an STI is a sexually transmitted disease (STD). STDs are con–

sidered pandemic. The WHO estimates that 333 million new cases of STDs (venereal diseases)

occur each year although a large percentage (~50%) goes unreported or undiagnosed. About half

Chapter 24 Microbial Diseases of the Urinary and Reproductive Systems

of all STDs affect people under age 25. Female adolescents are at significant risk because their

cervical lining is especially prone to bacterial invasion, and yet STDs in young women are more

Bacterial STDs (pp. 760–766)

Bacterial infections are among the more familiar STDs.

Gonorrhea

Gonorrhea is a disease that has been recognized for centuries. In men, gonorrhea causes acute

inflammation, extremely painful frequent urination, and a purulent (pus-filled) discharge. Dam-

age to internal reproductive organs may result in infertility. In women, the infection is often

asymptomatic while silently damaging the uterine tubes and resulting in sterility. It can also

cause pelvic inflammatory disease (PID). Newborns infected during vaginal birth may suffer in-

flammation of the cornea, potentially leading to blindness.

Syphilis

Syphilis has four phases:

1. In primary syphilis, a small, hard, extremely infectious chancre (lesion) fills with spirochetes

2. In about two-thirds of cases, Treponema invades the bloodstream and causes the symptoms of

4. About a third of patients advance to tertiary syphilis, a hyperimmune response characterized

by swollen lesions called gummas on the skin or other organs, destruction of cardiovascular

Instructor’s Manual for Microbiology with Diseases by Body System, 5e

or central nervous system tissue, personality changes, insanity, or blindness. Few or no spiro-

chetes may be present.

Infection with Treponema pallidum, a spirochete, causes syphilis. Virulence factors include

glycocalyx, adhesins, and the production of hyaluronidase. T. pallidum is an obligate parasite of

humans and is transmitted almost solely by sexual contact. It can also be transmitted from a

pregnant woman to her fetus and rarely through blood transfusion.

Chlamydial Infections

The most common sexually transmitted bacterium is Chlamydia trachomatis. Infection is often

asymptomatic (~85%) in females. In males, more than 75% of the infection can cause urethritis,

painful urination, purulent discharge, epididymitis (inflammation of the epididymis) or orchitis

(inflammation of a testis), and sterility. When newborns are infected at birth, an eye disease

Viral STDs (pp. 766–769)

Viruses are the most common causes of STDs, including AIDS, genital herpes, and genital

warts. (AIDS is discussed in Chapter 18.)

Genital Herpes

Genital herpes manifests as numerous small blisters on the genitals, around the rectum, or on

adjacent areas of skin. The blisters burn and itch before breaking to become painful ulcers. Pa-

tients experience fever, malaise (feeling of general discomfort or uneasiness), myalgia, and de-

creased appetite. Two enveloped dsDNA viruses called human herpesviruses (HHV) cause

Chapter 24 Microbial Diseases of the Urinary and Reproductive Systems

Genital Warts

Genital warts appear on the genitalia, skin, anus, or rectum and range in size from barely visi-

ble bumps to giant, cauliflower-like growths called condylomata acuminata. Genital warts

may be itchy or painful, and rarely they may bleed or cause increased vaginal discharge. About

30 varieties of the double-stranded DNA, icosahedral naked viruses in the genus Papilloma-

virus, cause genital warts. These viruses are called human papillomaviruses (HPVs). About half

Protozoan STDs (pp. 769–770)

Sexual activity can transmit several protozoa, including intestinal parasites such as Giardia and

Cryptosporidium; however, this is not the regular way these protozoa are infective. The proto-

zoan Trichomonas normally infects the reproductive system.

Trichomoniasis

Trichomonads are flagellated protozoan parasites of animals and humans. Trichomonas vaginal-

is is the one pathogenic species, causing an STD called trichomoniasis or trich. Infection is

usually asymptomatic in males. In females, it causes a foul-smelling, yellow-green vaginal dis-

charge and vaginal irritation. There may also be lesions of the genitalia, abdominal pain, dysu-