Neisseria

gram-negative cocci that inhabit the mucous membranes

Readings Question #1

• One of the most common communicable diseases in the United States is gonorrhea, an STD caused by Neisseria gonorrhoeae. How does it attach to the tissues? How does it spread? What is its only natural host? What is its most common symptoms? When do symptoms appear?

Gonorrhea

• leukocytes• men: single unprotected exposure- 20-35%• women: 60-90%• Men:urethra

sterilityvas deferens

Women

• insidious• cervix• abdominal pain: PID

Men and Women• Untreated gonorrhea can disseminate and

become a serious, systemic infection.

Opthalmia Neonatorum

• antibiotics/silver nitrate

Antibiotic Resistance

• penicillin• fluorquinolone antibiotics• frequent coinfection with chlamydia• include antichlamydial in treatment– tetracycline

• Diagnosis: ELISA- detects N. gonorrhoeae

Readings Question 2

• Gonorrhea is a common cause of pelvic inflammatory disease in women. What are its signs and symptoms? What is epididymitis?

PID

• 1 in 10 women• 1 in 4: serious complications• coinfection with chlamydial bacteria • barrier contraceptives with spermicides• salpingitis: most serious form– ectopic/tubal pregnancy

• Treatment: gonococcus and chlamydia

Neisseria meningitides(meningococcus)

• aerobic, gram-negative bacteria with a capsule, pili, and production of endotoxins

• endotoxins are primarily responsible for symptoms

• most distinguishing feature is the rash that does not face when pressed

Meningococcus Rash

• Spots do not blanch when pressed with the glass.

Meningococcus Rash

Septicemic Rash

Meningococcal Meningitis

• typically begins with a throat infection which leads to bacteremia, and eventually meningitis

• generally occurs in children under 2 years• residual damage• sporadic outbreaks• vaccine• penicillin and cephalosporin

Menningococcemia

Gangrene of the hand of a 4 month old.

Clostridium

• obligate anaerobes• rod-shaped cells that contain endospores

• Clostridium botulinum: botulin

Readings Question 3

• Clostridium tetani causes what bacterial infection? Describe the characteristics of this microbe. Where is it found? What are its symptoms, and what causes them?

Gas Gangrene

Gas Gangrene

Readings Question #4

Clostridium perfringens is the causative agent of a postmortem condition known as tissue gas.

List 3 things that may result in this condition in the decedent.

List 7 conditions that predispose the decedent to tissue gas formation.

Food Intoxication

• Clostridium perfringens Gastroenteritis: one of the more common forms of food poisoning in the United States

• improper handling of meat during the slaughtering of animals

• 2 main causes: 1) keeping foods warm for more than 20 minutes

2) inadequate refrigeration

Corneybacterium

• Diptheria: caused by Corneybacterium diptheria

• 2 forms:1) respiratory2) cutaneous

Respiratory Diptheria

• Begins with a sore throat, followed by general malaise and swelling of the neck.

• DTaP vaccine• antibiotics used in conjunction with antitoxin

Cutaneous Diptheria

• C. diptheria infects the skin• minimal systemic circulation of the toxin• slow-healing ulcerations covered by a gray

membrane

Reading Question #5

Tularemia/Rabbit Fever is a zoonotic disease caused by the bacterium Francisella tularensis. What are the characteristics of this parasite? How can it enter the body? What are the signs associated with this disease?

Proliferation can lead to sepsis.Streptomycin is the antibiotic of choice.

Salmonella typhi

• most virulent strain and causes typhoid fever• pathogen not found in animals• spread only in the feces of other humans• S. typhi multiply within phagocytic cells,

disseminated into multiple organs• phagocytic cells “lyse”• high fever and headache are 1st symptoms• diarrhea in 2nd or 3rd week

Typhoid Fever

• 350 – 500 annual cases in the United States• 70% foreign travel• worldwide:

16 million annual cases600,000 deaths/year

• cephalosporins

1909 newspaper illustration