what is the ability of the pathogen to invade and multiply in the host referred to as? course hero

How do pathogens survive and multiply in hosts?

In order to survive and multiply in a host, a successful pathogenmust be able to: (1) colonize the host; (2) find a nutritionally compatible niche in the host body; (3) avoid, subvert, or circumvent the host innate and adaptive immune responses; (4) replicate, using host resources; and (5) exit and spread to a new host.

What is an introduction to pathogens?

Introduction to Pathogens. Disable Glossary Links In this Page Pathogens Have Evolved Specific Mechanisms for Interacting with Their Hosts The Signs and Symptoms of Infection May Be Caused by the Pathogen or by the Host's Responses Pathogens Are Phylogenetically Diverse

How do bacterial pathogens colonize and invade?

How bacterial pathogens colonize their hosts and invade deeper tissues Bacterial pathogens have evolved a wide range of strategies to colonize and invade human organs, despite the presence of multiple host defense mechanisms.

What is an obligate and facultative pathogen?

Some of those that do cause disease can only replicate inside the cells of the human body and are called obligate pathogens. Others replicate in an environmental reservoir such as water or soil and only cause disease if they happen to encounter a susceptible host; these are called facultative pathogens.

What is the most common form of infection?

What is rapid division?

What is ABX in microrganism?

Is microorganism replicating?

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What is the most common form of infection?

Viruses are the most common form of infection. They contain deoxyribonucleic acid (DNA) and RNA for their genetic information. They do not produce exotoxins or endotoxins.

What is rapid division?

rapid division, the ability to survive inside a host cell, coating the viral capsid with self-antigens from the host cell, antigenic variation , neutralization of immune complexes , complement evasion, immune suppression , and tissue damage .

What is ABX in microrganism?

ABX inhibit protein synthesis which is necessary for microrganism replication

Is microorganism replicating?

Microorganism is replicating, but symptoms have not yet developed.

What is the primary defense mechanism against bacteria?

Invasion is the direct confrontation with an individual's primary defense mechanisms against only bacteria, which include the complement system, antibodies, and phagocytes, such as neutrophils and macrophages.

What are the host defenses against fungal infections?

The host defense against fungal infection includes the fungistatic properties of neutrophils and macrophages. T lymphocytes are crucial in limiting the extent of infection and producing cytokines to further activate macrophages. The other options are not true of fungal infections.

What are exotoxins?

Exotoxins are proteins released during bacterial growth. The other options are not true of exotoxins.

Which pyrogens act directly on the hypothalamus?

Endogenous pyrogens acting directly on the hypothalamus.

What are the primary targets of HIV?

The primary cellular targets for HIV include CD4+ Th cells, macrophages, and NK cells. The other options are not the primary target cells of HIV.

How do cytokines raise the thermoregulatory set point?

Cytokines seem to raise the thermoregulatory set point through stimulation of prostaglandin synthesis and turnover in thermoregulatory (brain) and nonthermoregulatory (peripheral) tissues. The other options do not accurately identify the appropriate chemical mediator.

How many stages of the infectious process are there?

From the perspective of the microorganisms that cause disease, the infectious process undergoes four separate stages of progression: (1) colonization, (2) invasion, (3) multiplication, and (4) spread.

How do pathogens survive?

In order to survive and multiply in a host, a successful pathogenmust be able to: (1) colonize the host; (2) find a nutritionally compatible niche in the host body; (3) avoid, subvert, or circumvent the host innate and adaptive immune responses; (4) replicate, using host resources; and (5) exit and spread to a new host. Under severe selective pressure to induce only the correct host cell responses to accomplish this complexset of tasks, pathogens have evolved mechanisms that maximally exploit the biology of their host organisms. Many of the pathogens we discuss in this chapter are skillful and practical cell biologists. We can learn a great deal of cell biology by observing them.

How do pathogenic bacteria cause toxicity?

Some pathogenic bacteria use several independent mechanisms to cause toxicity to the cells of their host. Anthrax,for example, is an acute infectious disease of sheep, cattle, other herbivores, and occasionally humans. It is usually caused by contact with spores of the Gram-positive bacterium, Bacillus anthracis. Unlike cholera, anthrax has never been observed to spread directly from one infected person to another. Dormant spores can survive in soil for long periods of time and are highly resistant to adverse environmental conditions, including heat, ultraviolet and ionizing radiation, pressure, and chemical agents. After the spores are inhaled, ingested, or rubbed into breaks in the skin, the spores germinate, and the bacteria begin to replicate. Growing bacteria secrete two toxins, called lethal toxinand edema toxin. Either toxin alone is sufficient to cause signs of infection. Like the A and B subunits of cholera toxin, both toxins are made of two subunits. The B subunitis identical between lethal toxin and edema toxin, and it binds to a host cell-surface receptorto transfer the two different A subunits into host cells. The A subunit of edema toxin is an adenylyl cyclase that directly converts host cell ATP into cyclic AMP. This causes an ionimbalance that can lead to accumulation of extracellular fluid (edema)in the infected skin or lung. The A subunit of lethal toxin is a zinc protease that cleaves several members of the MAPkinase kinase family (discussed in Chapter 15). Injection of lethal toxin into the bloodstream of an animal causes shock and death. The molecular mechanisms and the sequence of events leading to death in anthrax remain uncertain.

Why are antibiotics used in bacteria?

Because bacteria form a kingdom distinct from the eucaryotes they infect (see Figure 25-3), much of their basicmachinery for DNAreplication, transcription, translation, and fundamental metabolismis quite different from that of their host. These differences enable us to find antibacterial drugs that specifically inhibit these processes in bacteria, without disrupting them in the host. Most of the antibioticsthat we use to treat bacterial infections are small molecules that inhibit macromolecular synthesis in bacteria by targeting bacterial enzymes that are either distinct from their eucaryotic counterparts or that are involved in pathways, such as cell wallbiosynthesis, that are absent in humans (Figure 25-8and Table 6-3).

How many chromosomes are in Vibrio cholerae?

Genetic organization of Vibrio cholerae. (A) Vibrio choleraeis unusual in having two circular chromosomes rather than one. The two chromosomes have distinct origins of replication (oriC1and oriC2). Three loci in pathogenic strains of V. choleraeare (more...)

How are bacteria classified?

Most can be classified broadly by their shape as rods, spheres, or spirals and by their cell-surface properties. Although they lack the elaborate morphological variety of eucaryotic cells, they display a surprising array of surface appendages that enable them to swim or to adhere to desirable surfaces (Figure 25-4). Their genomes are correspondingly simple, typically on the order of 1,000,000–5,000,000 nucleotidepairs in size (compared to 12,000,000 for yeastand more than 3,000,000,000 for humans).

What is a parasite in biology?

But a pathogenor a parasite, like any other organism, is simply trying to live and procreate.

What are the symptoms of infectious disease?

Some hallmarks of bacterial infection, including the swelling and redness at the site of infection and the production of pus (mainly dead white blood cells), are the direct result of immune systemcells attempting to destroy the invading microorganisms. Fever, too, is a defensive response, as the increase in body temperature can inhibit the growth of some microorganisms. Thus, understanding the biology of an infectious disease requires an appreciation of the contributions of both pathogenand host.

What is the most common form of infection?

Viruses are the most common form of infection. They contain deoxyribonucleic acid (DNA) and RNA for their genetic information. They do not produce exotoxins or endotoxins.

What is rapid division?

rapid division, the ability to survive inside a host cell, coating the viral capsid with self-antigens from the host cell, antigenic variation , neutralization of immune complexes , complement evasion, immune suppression , and tissue damage .

What is ABX in microrganism?

ABX inhibit protein synthesis which is necessary for microrganism replication

Is microorganism replicating?

Microorganism is replicating, but symptoms have not yet developed.