Chapter 13 Sexually Transmitted and Contact Transmitted Bacterial

Chapter 13 Sexually Transmitted and Contact Transmitted Bacterial Diseases

Sexually transmitted diseases (STDs) remain a health problem in the United States and around the world, the seriousness of which is underscored by a number of infections. Figure 13. 01: Reported cases of notifiable diseases in the United States, 2007.

13. 1 Portions of the Female and Male Reproductive Systems Contain an Indigenous Microbiota • The male and female reproductive systems consist of primary and accessory sex organs. • The female reproductive system is prone to more infections than the male. • The male urethra has indigenous microbes Figure 13. 02 B: Female reproductive tract. Figure 13. 02 A: Male reproductive system.

Common vaginal infections come from indigenous microbes. • The female vagina, vulva and cervix have indigenous microbiota. • The vagina has Lactobacillus which produce an acid p. H. • Chemicals fluctuate with menstrual cycle providing protection. • Common vaginal microbiota cause bacterial vaginosis including Gardnerella vaginalis. Figure 13. 03: Fluctuations in Antimicrobial Chemicals in the Vagina during the Menstrual Cycle. Figure 13. 04: Gardnerella vaginalis. © Dennis Kunkel Microscopy, Inc. /Phototake/Alamy Images

13. 2 Many Sexually Transmitted Diseases Are Caused by Bacteria STDs continue to be a major public health challenge in the United States. • STDs were commonly called venereal diseases (venerea = referring to Venus, the Roman goddess of love), now called STIs. Figure 13. 05: Incidence of Chlamydia, Gonorrhea, and Syphilis—U. S. and Territories, 1995– 2006.

• Chlamydial urethritis is the most frequently reported STD globally and in the US • Chlamydial urethritis (chlamydia) is caused by Chlamydia trachomatis. • Chlamydia is one of several diseases known as a non-gonococcal urethritis (NGU). • 85– 90% of infected individuals are asymptomatic. • It has enzymes that inhibit the host inflammatory response © Dan Guravich/Photo Researchers, Inc. Figure MF 13. 01: Evolution.

• C. trachomatis cannot make its own ATP and must rely on the host cell for energy. • It has two phases: the infectious elementary body and the noninfectious reticulate body. Figure 13. 06: Chlamydial life cycle.

Figure 13. 07 : Chlamydial inclusion. © Dr. R. Dourmashkin/Photo Researchers, Inc. • Spreading to the fallopian tubes can cause salpingitis. • Left untreated, it can cause pelvic inflammatory disease (PID). • Increases the danger of infertility or ectopic pregnancies • Chlamydia can also occur in the pharynx or anus. • Males complain of painful urination and watery discharge. • It can cause infertility in males. • Can cause blindness in infants

• Gonorrhea can be an infection in any sexually active person. • Gonorrhea is caused by Neisseria gonorrhoeae, known as the gonococcus. • Gonorrhea can also affect the: • • reproductive organs. Pharynx. Rectum. Eyes. Figure 13. 08: TEM of N. gonorrhoeae cells. • Infants can contract gonococcal ophthalmia while passing through the birth canal. © Dr. David M. Phillips/Visuals Unlimited

• In females it can spread to the fallopian tubes, causing: • • pelvic inflammatory disease (PID). possible sterility. ectopic pregnancy. Salpingitis. • Many affected females are asymptomatic. • Males experience: • • • tingling of the penis. pain when urinating. penile discharge. swollen lymph nodes. painful testicles. • It can cause infertility in males. Courtesy of Joe Miller/CDC Figure 13. 09: Gonococcal urethral smear.

Syphilis is a chronic infectious disease. • Syphilis is one of the top five most reported microbial diseases in the United States. Figure 13. 11: Treaponema pallidum spirochete. Courtesy of CDC • It is caused by Treponema palladium, a Figure MF 13. 02: A victim spirochete for which humans are the only of syphilis in 1496. © Mary Evans Picture host. Library/Alamy Images

Courtesy of Dr. Gavin Hart/CDC Courtesy of M. Rein, VD/CDC • Primary syphilis is characterized by a painless lesion (chancre) where the bacteria entered the body. • Secondary syphilis involves: • fever. • skin rash. • swollen lymph nodes. • A chronic latent stage of 3– 30 years follows in which relapses of secondary syphilis occur. • It is curable in early stages by Penicillin. Figure 13. 10 A(top) & B(left): Syphilis chancre and chest rash.

Tertiary syphilis involves formation of gummas that can cause: • weakening and bursting of blood vessels. • degeneration of spinal cord tissue. • brain damage leading to personality and judgment changes and insanity. Figure 13. 10 C: Tertiary syphilis gumma. Courtesy of Susan Lindsley/CDC • Congenital syphilis can occur in the fetus of a pregnant woman, leading to: • stillbirth. • birth defects like Hutchinson’s triad.

• Other sexually transmitted diseases also exist. • Chancroid causes painful genital ulcers. • Chancroid (soft chancre) is caused by Haemophilus ducreyi. • It is common in areas with low public health standards and tropical climates. • A papule forms at the entry site that fills with pus and breaks down. • This leaves a painful, bleeding ulcer. • Lesions often form on the penis in men, labia or clitoris in females.

13. 3 Urinary Tract Infections Are the Second Most Common Body Infection • The urinary system removes waste products from the blood and helps maintain homeostasis • The distal region of the urethra is usually colonized by a variety of bacterial species. • defense mechanisms include shedding of outer cells with flow of slightly acidic urine Figure 13. 12: Female Urinary Tract.

urinary tract infections are the second most common type of infection in the body. • Occur primarily in the urethra and bladder • 50% of humans suffer a UTI at some time in their lives, women are at higher risk • Commonly caused by E. coli • UTIs have similar signs and symptoms. • • Urethritis Cystitis Prostatitis Pyelonephritis Figure 13. 13: Common Causes of UTIs.

13. 4 Contact Diseases Can Be Caused by Indigenous Bacterial Species • Skin protects underlying tissues from microbial conlonization. • Skin is protected by keratin, cells sloughing off in the epidermis, dendritic cells, sweat and sebum Figure 13. 14: Layers of the Skin.

• Indigenous microbiota in 3 skin sites • Sebaceous – forehead and back, Proprionibacterium acnes in hair follicles • Moist sites – navel, groin, foot have Corynebacterium • Dry sites – most diverse with Staphylococcus, Acinetobacter and Micrococcus Figure 13. 15: Topographical Distribution of the Skin Microbiota. Courtesy of Darryl Leja, NHGRI

• 85% of adolescents and young adults develop acne. Figure 13. 16 A: Acne Vulgaris. © Kwangshin Kim/Science Photo Library • Acne is a chronic inflammation caused by excess sebum and Proprionibacterium acnes. © Medical-on. Line/Alamy Images Acne is the most common skin condition in the developed world. • It starts when hair follicles become swollen with sebum and keratinocytes. Figure 13. 16 B: Propionibacterium acnes.

• Progression of acne • Open comedones are blackheads • Closed comedones are pimples • Treatment mild soap and benzoyl peroxide, severe cases may require antibiotics Figure 13. 18: Skin Lesions of Acne. Adapted from: Mc. Kinley, M. and O’Loughlin, V. Human Anatomy, Second edition. Mc. Graw-Hill, 2007.

Indigenous microbiota of the skin can form biofilms. • Skin wounds through surgery can introduce indigenous microbes to tissues and cause an infection. • Chronic wounds are the result of lack of blood flow. • Acute wounds are from cuts, bites or tubes inserted into patients like catheters or IVs causing bloodstream infections in hospitalized patients. © Dr. P. Marazzi/Photo Researchers, Inc. Figure MF 13. 05: Infected skin wound.

13. 5 Contact Diseases Can Also Be Caused by Exogenous Bacterial Species • Staphylococcus aureus infections can create abscesses and/or produce exotoxins. • • • Folliculitis Abscess Furuncle Carbuncle Impetigo Figure 13. 19 A: Staphylococci and Skin Abscesses. Figure 13. 19 B: Severe carbuncle on the back of the head/neck. © Medical-on-Line/Alamy

© Dr. Ken Greer/Visuals Unlimited, Inc. Toxin-generated S. aureus Contact Diseases © SPL/Photo Researchers, Inc. Figure 13. 20 A: Impetigo. Figure 13. 20 B: Scalded Skin Syndrome. Courtesy of CDC • Impetigo has highly contagious blisters • Scalded Skin Syndrome in infants and young children • Epidermis peels off • Toxic Shock Syndrome • 1980 s outbreak with ultra absorbent tampons • High fever, sunburn like rash, peeling skin Figure 13. 20 C: Toxic Shock Syndrome.

Streptococcal diseases can be mild to severe. © Dr. Gladden Willis/Visuals Unlimited/Corbis. © Medical-on-Line/Alamy Images • Group A strep (GAS) attach to cells and secrete toxins, capsule and M protein. • Streptococcus pyogenes is β hemolytic on blood agar. Figure 13. 21 A: Streptococci. Figure 13. 21 B: β hemolysis.

Group A strep causes • Strep throat or pharyngitis • Impetigo (along with Staphylococcus aureus) • Cellulitis • Erysipelas • Streptococcal toxic shock syndrome • Necrotizing fasciitis Figure 13. 22: Facial erysipelas. Courtesy of Dr. Thomas F. Sellers, Emory University/CDC Figure 13. 23: Necrotizing fasciitis. © Dr. M. A. Ansary/Photo Researchers, Inc.

Other wounds also can cause skin infections. • Traumatic wounds to the skin surface can lead to localized infections. • Cuts, compound fractures, burns • Soilborne bacteria cause gas gangrene • Pseudomonas biofilm infections Figure 13. 24: A Burn Trauma to the Leg. © Dr. M. A. Ansary/Photo Researchers, Inc.

Leprosy (Hansen Disease) is a chronic, systemic infection. • Mycobacterium leprae infects the skin and peripheral nerves, deformities due to lack of pain sensation. • Disfigures skin and bones, twisting limbs and causing claw hands. • 2600 year old disfiguring disease has finally met it’s match with multidrug therapy. Figure 13. 25 A: Boy with leprosy before treatment. Figure 13. 25 B: Boy with leprosy after treatment. Courtesy of American Leprosy Mission, 1 ALM Way Greenville, SC 29601

13. 6 Several Contact Diseases Affect the Eye Figure 13. 26: Eye Anatomy. © Medical-on-Line/Alamy Images • Blepharitis is an infection of the eyelid margin or stye • Conjunctivitis, called pink eye is a highly contagious infection of the conjunctiva. • Symptoms include pain, swelling, redness and discharge that may cause the eyelids to stick together. Figure 13. 27: Conjunctivitis.

Blindness can be caused by infection of a newborn through the birth canal. • Neisseria gonorrhoeae • Chlamydia trachomatis causes ocular trachoma, leading preventable cause of blindness • Prevention in the US is antibiotic drops at birth. Figure 13. 29: Worldwide Trachoma. Map by Silvio Mariotti/WHO Figure 13. 30: Trachoma. © Suzanne Porter/Alamy