ACTINOMYCES BACTERIOLOGY Actinomyces are typically elongated Gram-positive rods that branch at acute angles (Figure 28-1). They are Gram-positive bacilli that grow slowly (4-10 days) under micro-aerophilic or strictly anaerobic conditions….
Antimalarial Quinolines Cinchona bark was used in Europe for the treatment of malaria beginning in the 1600s. Its active ingredient is a quinoline alkaloid called quinine. Synthesis of new quinolines…
FIGURE 7–1. Stages of poliovirus pathogenesis. The diagram illustrates multiple steps of poliovirus pathogenesis, starting from virus entry through oropharynx (fecal-oral transmission), virus multiplication at the site of entry (gut),…
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.)…
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…
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…
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…
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…
