jejuni. Campylobacter fetuscauses spontaneous abortion in domestic animals.
Campylobacter jejunicauses inflammation of the digestive tract (enteritis) result-
ing in food-borne intestinal diseases. Another common aerobic/microaerophilic,
motile, helical/vibroid, gram-negative bacterium that is pathogenic is Helicobacter
pylori.Helicobacter pyloricause gastric ulcers in humans.
Gram-Negative Aerobic Rods and Cocci
Bacteria that are members of the gram-negative aerobic rods and cocci group
include many bacteria that cause disease in humans and bacteria that are impor-
tant to industry and the environment. There are 11 bacteria in this group:
- Pseudomonads. Pseudomonadsare rod-shaped bacteria with polar flagella,
which give the bacteria mobility. They need oxygen to grow and obtain
energy by decomposing organic material. Pseudomonads are found in soil,
fresh water and marine environments. - Pseudomonas aeruginosa.Pseudomonas aeruginosais a pathogenic bac-
terium that infects the urinary tract and wounds in humans. It also causes
infections in burn injuries. - Legionella pneumophilia. Legionella pneumophiliais a bacterium identi-
fied in 1976 when it infected and killed members of the American Legion
at their convention in Philadelphia. Infection caused by the Legionella
pneumophiliabacterium is commonly referred to as Legionnaire’s disease. - Legionella micdadei. Legionella micdadeiis the bacterium that infects lungs
and causes a strain of pneumonia commonly called Pittsburgh pneumonia. - Moraxella lacunata. Moraxella lacunatais an egg-shaped (coccobacilli)
bacterium that can infect the membrane that lines eyelids called the con-
juntiva, causing a condition known as conjunctivitis (pink eye). - Neisseria. Neisseriais a double-spherical (diplo-coccus) bacterium that
can live with or without oxygen (anaerobic) and is usually found on
mucous membranes of humans. One type of Neisseria called Neisseria
gonorrhoeaecauses the sexually transmitted disease gonorrhea. Another
type is Neisseria meningitidis(N. meningitis), the bacterium that infects
the mucous membranes of the nose and throat (nasopharyngeal), causing
a sore throat. Neisseria meningitidiscan cause meningitis if the bacterium
enters blood and cerebral spinal fluid where it can infect the protective
covering (meninges) of the brain and spinal cord. Meningitis is inflamma-
tion of the meninges.
CHAPTER 10 The Prokaryotes^155