25 Streptococci and Enterococci
FIGURE 25–1. Group A streptococcus (GAS) Gram stain. Note the oval cocci chaining end to end (arrow). (Image contributed by professor Shirley Lowe, University of California, San Francisco School of…
54 Intestinal Nematodes
Impact Six intestinal nematodes commonly infect humans: Enterobius vermicularis (pinworm), Trichuris trichiura (whipworm), Ascaris lumbricoides (large roundworm), Necator america-nus and Ancylostoma duodenale (hookworms), and Strongyloides stercoralis. Together, they infect more…
21 Bacteria—Basic Concepts
FIGURE 21–1. Shapes of bacteria. A. Staphylococcus aureus, cocci arranged in clusters; scanning electron micrograph (SEM). B. Group B streptococci, cocci arranged in chains; SEM. C. Bacillus species, straight rods;…
51 Apicomplexa and Microsporidia
PARASITOLOGY DEFINITION The plasmodia are Apicomplexa in which the sexual and asexual cycles of reproduction are completed in different host species. The sexual phase occurs within the gut of mosquitoes…
33 Enterobacteriaceae
BACTERIOLOGY The Enterobacteriaceae are among the largest bacteria, measuring 2 to 4 μm in length with parallel sides and rounded ends. Forms range from large coccobacilli to elongated, filamentous rods….
29 Clostridium, Peptostreptococcus, Bacteroides, and Other Anaerobes
you can, you had better leave the profession: cast your diplomainto the fire; you are not worthy to hold it. —Jacob M. Da Costa (1833-1900): College and Clinical Record The…
6 Viruses—Basic Concepts
FIGURE 6–1. Size comparison of viruses with other microbes. (Adapted with permission from Willey JM: Prescott, Harley, & Klein’s Microbiology, 7th edition. McGraw-Hill, 2008.) Viruses range in size from 20…
14 Herpesviruses
Large, enveloped, double-stranded DNA viruses Eight HHVs cause a range of diseases HERPESVIRUSES: GROUP CHARACTERISTICS VIROLOGY All herpesviruses are morphologically similar, with an overall size of 180 to 200 nm….
37 Spirochetes
BACTERIOLOGY MORPHOLOGY AND STRUCTURE The spiral morphology of spirochetes (Figure 37–1) is produced by a flexible, peptidoglycan cell wall around which several axial fibrils are wound. The cell wall and…
16 Arthropod-Borne and Other Zoonotic Viruses
ARTHROPOD-BORNE ZOONOTIC ARBOVIRUSES VIROLOGY In most cases, the zoonotic viruses were first named after the place of initial isolation (eg, St. Louis encephalitis) or after the disease produced (eg, yellow…
