This illustration depicts a three-dimensional (3D) computer-generated image of a number of rod-shaped, drug-resistant Shigella bacteria. The artistic recreation was based upon scanning electron microscopic (SEM) imagery. Note that the exterior of the Shigella bacterium is fimbriated, covered by numerous thin, hair-like projections, imparting a furry appearance.
Shigella usually causes diarrhea (sometimes bloody), fever, and abdominal pain. Sometimes it causes serious complications such as reactive arthritis. High-risk groups include young children, people with inadequate handwashing and hygiene habits, and men who have sex with men. See PHIL 21920, for another, closer view of these bacteria.
Resistance to traditional first-line drugs such as ampicillin and trimethoprim-sulfamethoxazole has become so high that physicians must now rely on alternative drugs like ciprofloxacin and azithromycin to treat infections, drugs to which Shigella has shown resistance. Resistant infections can last longer than infections with susceptible bacteria (bacteria that can be treated effectively with antibiotics).
Shigella causes approximately 500,000 diarrheal illnesses, 5,500 hospitalizations, and 40 deaths each year in the United States. CDC is seeing resistance to ciprofloxacin in 1.6% of the Shigella cases tested and resistance to azithromycin in approximately 3%. Because initial treatment can fail, costs are expected to be higher for resistant infections.
See the links below for more on the subject of shigellosis, an microbial drug resistance.