Essentials of Anatomy and Physiology

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Table 22–3 DISEASES CAUSED BY BACTERIA (Continued)

Bacterial Species Discussion/Disease(s) Caused

Clostridium tetani

gram () bacillus

(spore-forming)

Clostridium botulinum

gram () bacillus

(spore-forming)

Clostridium difficile

gram () bacillus

(spore-forming)

Corynebacterium

diphtheriae

gram () bacillus

Listeria monocytogenes

gram () bacillus

Salmonella typhi

gram () bacillus

Salmonella enteritidis

and other species

gram () bacillus

Shigella species

gram () bacillus

Escherichia coli, Serratia

marcescens, Proteus

vulgaris, and other

genera of gram () bacilli

Escherichia coli 0157:H7

Pseudomonas aeruginosa

gram () bacillus

Burkholderia cepacia

gram () bacillus

Yersinia pestis

gram () bacillus

Francisella tularensis

gram () bacillus

Tetanus: normal soil flora may contaminate wounds; spores require anaerobic condi-

tions. The toxin prevents muscle relaxation, resulting in muscle spasms. May be fatal

if respiratory muscles are affected. The vaccine contains the toxoid (inactivated toxin)

and has made this a rare disease in the U.S. Boosters are strongly recommended for

older adults.

Botulism: normal soil flora; spores present in anaerobic food containers germinate and

produce the toxin, which causes paralysis. Respiratory paralysis may be fatal without

assisted ventilation. May cause infant botulism in children less than 2 years of age

who have ingested spores. No vaccine. Treatment is antitoxin (antibodies).

Diarrhea: the most common identifiable cause of antibiotic-associated diarrhea

(pseudomembranous enterocolitis); has become a significant nosocomial pathogen.

No vaccine.

Diphtheria: toxin causes heart failure and paralysis; a pseudomembrane that grows in

the pharynx may cover the larynx and cause suffocation. Vaccination of infants (DTP)

has made this a very rare disease in the U.S. Older adults should receive boosters

(combined with tetanus: DT).

Listeriosis: septicemia and meningitis in the elderly, infants, and unborn; may cause mis-

carriage or stillbirth. The bacteria are found in soil and in animals such as cattle. In

the U.S., food poisoning outbreaks traced to contaminated milk or milk products.

Sporadic cases traced to undercooked hot dogs or chicken or to cold cuts from deli-

catessen counters. No vaccine.

Typhoid fever: intestinal infection with erosion and septicemia; subsequent infection of

liver, gallbladder, or kidneys. Upon recovery, the carrier state (bacteria in gallbladder)

may occur. Rare in the U.S. because of chlorination of drinking water. The vaccine is

used in endemic areas of the world such as Asia.

Salmonellosis: food poisoning following consumption of contaminated animal products

such as poultry or eggs. Diarrhea is usually self-limiting, but it may be fatal for the

elderly. In the U.S. estimates are 4 million cases per year. No vaccine.

Bacillary dysentery: mild to severe diarrhea; may be fatal because of dehydration and

circulatory shock. Usually transmitted by food prepared by people with mild cases.

No vaccine. An important cause of illness in daycare centers.

Normal colon flora; cause opportunistic infections when introduced into any other part

of the body. This group is one of the most common causes of nosocomial infections

(urinary tract, pneumonia, skin infections).

Hemorrhagic colitis and hemolytic uremic syndrome, potentially fatal. The bacteria may

survive in undercooked meat, especially ground beef. A vaccine is in the research

stage.

Normal soil and water flora; also transient in human intestines. A serious potential

pathogen for patients with severe burns, cystic fibrosis (causes pneumonia), or can-

cer. May even survive in disinfectant solutions. No vaccine.

Pneumonia: especially in people with cystic fibrosis or those with compromised immune

systems. No vaccine. (Former genus name: Pseudomonas.)

Bubonic plague: swollen lymph nodes, septicemia, and hemorrhagic pneumonia; often

fatal. Animal reservoirs are prairie dogs, ground squirrels, and other rodents. Rats and

people are infected by fleas (the vector). In the U.S., the few cases each year occur in

the Southwest. The vaccine is no longer available.

Tularemia (rabbit fever): septicemia and pneumonia; not often fatal but very debilitat-

ing. Reservoirs are wild animals and birds. People are infected by vectors (ticks, lice,

and biting flies), by ingestion of contaminated animal meat, or by inhalation. No

vaccine. Tularemia is a potential biological weapon.

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