Exam 23: Microbial Interactions With Humans

Animals that lack CXCR4 and CCR5 proteins are immune to HIV infection.

A loose network of polymers extending outward from a cell is called a(n)

ALL microorganisms that live in the human body are harmful.

Streptococcus mutans can produce dextran when sucrose is present in the absence of the enzyme dextransucrase.

Invasion is the ability of a pathogen to enter into host cells or tissues,spread,and cause disease.

Virulence refers to the ability of an organism to cause disease.

Design an experiment to determine whether a potential pathogen produces hemolysins.

Which of the following does NOT affect pathogen growth?

Only particles smaller than ________ µm in diameter reach the lungs.

Extensive growth of the streptococci in a thick bacterial layer on acidic glycoproteins on the teeth is called

Cholera begins following a bite from a mosquito.

The collective term for the organisms living on or in the human body is

Following antibiotic therapy,patients are often administered ________ to facilitate recolonizaton of normal flora.

Staphylococcus aureus produces ________,leading to fibrin clots that protect them from attack by host cells.

The dose of an antigen that kills 50% of animals in a test group and is used to estimate the virulence of a pathogen is known as

Bacteria found in the mouth in the first years of life are well-adapted to biofilm formation.

________ in saliva cleaves glycosidic linkages in peptidoglycan present in bacterial cell walls,weakening the wall and causing cell lysis.

The Limulus amebocyte lysate assay is used to detect endotoxin in clinical samples such as serum or cerebrospinal fluid.

Pathogenic strains of Escherichia coli usually express

Explain how diet plays a role in host susceptibility to infection.