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…
TOXOCARA TOXOCARA CANIS: PARASITOLOGY AND LIFE CYCLE (FIGURE 55–1) FIGURE 55–1. Life cycle of Toxocara canis. (Reproduced with permission from Roberts RL, Janovy J, Nadler S: Foundations of Parasitology, 9th…
Clinical effects depend on whether humans are definitive hosts or intermediate hosts Tissue cysts, not intestinal worms, cause serious disease PARASITOLOGY MORPHOLOGY Like all helminths, tapeworms lack vascular and respiratory…
Found in flora of vertebrates These organisms are elongated or oval and typically measure 10 to 20 μm in length. They often possess a rudimentary cytostome (mouth aperture) and organelles,…
BACTERIOLOGY STRUCTURE The mycobacteria are slim, poorly staining bacilli, which demonstrate the property of acid-fastness. They are nonmotile, obligate aerobes that do not form spores. The cell wall contains peptidoglycan…
FIGURE 30–1. Neisseria gonorrhoeae. Gram stain of urethral exudate. Note the many pairs of Gram-negative bean-shaped diplococci (arrow) collected in polymorphonuclear neutrophils (PMNs) and free in the purulent material. The…
Definitions • Antibiotics—antimicrobials of microbial origin, most of which are produced by fungi or by bacteria of the genus Streptomyces. • Antimicrobials—substances used in the treatment of infectious diseases. In…
FIGURE 4–1. Specimens for the diagnosis of infection. A. Direct specimen. The pathogen is localized in an otherwise sterile site, and a barrier such as the skin must be passed…
CRYPTOCOCCUS CRYPTOCOCCUS NEOFORMANS and CRYPTOCOCCUS GATTII Cryptococcus is a genus of yeast 4 to 6 μm in diameter that produces a characteristic capsule (Figure 47–1), extending the overall diameter to…
HEPATITIS A VIROLOGY Hepatitis A virus (HAV) belongs to the Picornaviridae (picornaviruses) family and Hepato-virus genus. It is an unenveloped (naked capsid), single-stranded, positive-sense RNA virus with a cubic (icosahedral)…
