15 Viruses of Diarrhea
FIGURE 15–1. Viruses of diarrhea. All are photographed at the same magnification to illustrate the size and morphologic differences. A. Rotavirus, B. Calicivirus. C. Astrovirus. (Courtesy of Claire M. Payne.)…
34 Legionella and Coxiella
BACTERIOLOGY STRUCTURE Legionella pneumophila is a thin, pleomorphic, Gram-negative rod that may show elongated, filamentous forms up to 20 μm long. In clinical specimens, the organism stains poorly or not…
3 Sterilization, Disinfection, and Infection Control
FIGURE 3–1. Kinetics of bacterial killing. A. Exponential killing is shown as a function of population size and time. B. Deviation from linearity, as with a mixed population, extends the…
38 Mycoplasma
GENERAL FEATURES Mycoplasma and Ureaplasma are taxonomically placed in the Mollicutes, a class of prokaryotes that lack a cell wall. Although their DNA does not resemble any other prokaryote, evolutionary…
52 Sarcomastigophora—The Amebas
PARASITOLOGY Entamoeba histolytica is found throughout the world and the causative agent of diarrhea and amebic dysentery. Infections may spread to extraintestinal sites and become life-threatening. Close to 500 million…
12 Enteroviruses
VIROLOGY MORPHOLOGY AND BIOLOGIC FEATURES As a group, the enteroviruses are picornaviruses that are extremely small (22-30 nm in diameter), naked capsid virions with icosahedral symmetry. They possess single-stranded, positive-sense…
11 Poxviruses
POXVIRUSES: GROUP CHARACTERISTICS Poxviruses are large, brick-shaped or ovoid, linear double-stranded DNA (130-300 kbp) containing core within a double membrane and a lipoprotein envelope carrying virions measuring approximately 350 ×…
48 Parasites—Basic Concepts
Major cause of disease and death worldwide Currently, about half of the world’s population lives in areas where malaria transmission could or does occur; of these, approximately 250 to 400…
