BACTERIA AND DISEASE

A __________ is the result of an undesirable relationship between the host and the pathogen, marked by interruption in the normal functioning of a body part or parts.

Disease

__________ is the invasion of the body by pathogenic microorganisms.

Infection

Mutualism is a form of __________ in which both organisms benefit from the relationship.

symbiosis

__________ describes the degree of pathogenicity of an organism or the degree to which an organism can produce disease.

Virulence

__________ refers to the presence of unwanted materials where they should not be or at concentrations above the normal.

Contamination

Bacteremia is the presence of __________ in the blood.

bacteria

Septicemia is the presence of __________ multiplying in the blood, usually from a source of infection.

actively multiplying bacteria

Koch’s postulates were published in __________ by Robert Koch.

1884

The first of Koch’s postulates states that the suspected organism must be absent in healthy individuals but __________ in those with the disease.

present

The chain of infection involves interaction among three components: the etiologic agent, the host, and the __________.

environment

A __________ serves as the continual source of disease producing microorganisms.

reservoir

Zoonotic infections are infectious diseases transmitted from an __________ to humans.

animal

Carriers are infected humans who may harbor the disease and __________ it.

transmit

Environmental reservoirs include organisms such as Histoplasma capsulatum found in __________.

soil

The __________ is the route by which an infectious agent exits its host.

portal of exit

Indirect contact can occur through __________ which refers to transmission of organisms through media such as food or water.

vehicle transmission

Mechanical transmission refers to the __________ transport of the organism on the insect’s feet or other body parts.

passive

The __________ is the final link in the chain of infection and is affected by various factors.

host

Infectious diseases can be classified based on how they behave within a host and the __________ of the microorganism.

source

Adhesion to mucosal surfaces is part of how organisms produce disease through __________.

invasiveness

Bacteria produce toxins that may cause damage to the cells or affect the normal physiologic function of the susceptible host; these toxins are classified into __________ and endotoxins.

exotoxins

The __________ period is characterized by early, mild symptoms of disease which are generally non-specific.

prodromal

The period of convalescence is marked by the recovery of the patient from the __________.

disease

What are bacteria?

Bacteria are single-celled microorganisms that can exist independently or as parasites.

What role do bacteria play in the human microbiome?

Bacteria help digest food, produce essential vitamins, and protect against harmful organisms.

What is the structure of a bacterial cell?

Bacterial cells have a cell wall, plasma membrane, cytoplasm, ribosomes, and genetic material (DNA).

What are the two main categories of bacteria based on their shape?

Cocci (spherical) and bacilli (rod-shaped).

What is the function of bacterial capsules?

Capsules protect bacteria from phagocytosis and help them adhere to surfaces.

What is antibiotic resistance?

Antibiotic resistance occurs when bacteria evolve and are no longer inhibited by antibiotics.

How are bacteria classified?

Bacteria are classified based on shape, staining properties, oxygen requirements, and genetic makeup.

What is a pathogenic bacterium?

A pathogenic bacterium is one that can cause disease in a host.

How do bacteria reproduce?

Bacteria reproduce asexually through a process called binary fission.

What are examples of diseases caused by bacteria?

Examples include tuberculosis, strep throat, and bacterial meningitis.

What is the function of bacterial endospores?

Endospores enable bacteria to survive harsh conditions.

What is a biofilm?

A biofilm is a collection of microorganisms that stick to a surface and each other.

What is a common method for culturing bacteria?

Bacteria are commonly cultured on nutrient agar plates.

How does the body defend itself against bacterial infections?

The immune system uses barriers, phagocytes, and antibodies to combat bacterial infections.

What is the difference between gram-positive and gram-negative bacteria?

Gram-positive bacteria have a thick cell wall, while gram-negative bacteria have a thin wall and an outer membrane.

What is bacteremia?

Bacteremia is the presence of bacteria in the blood.

What is septicemia?

Septicemia is a serious bloodstream infection caused by bacteria.

How can bacterial infections be diagnosed?

Diagnosis can be made through blood tests, cultures, and microscopic examination.

What are exotoxins?

Exotoxins are potent toxins released by bacteria into their environment.

What are endotoxins?

Endotoxins are components of the bacterial cell wall that can trigger immune responses.

What is the lag phase in bacterial growth?

The lag phase is a period of adaptation before bacteria begin to multiply.

What is the log phase in bacterial growth?

The log phase is characterized by rapid cell division.

What is the stationary phase in bacterial growth?

The stationary phase occurs when nutrient depletion and waste accumulation slow growth.

What are viruses?

Viruses are smaller infectious agents that require a host cell to replicate.

What is a parasite?

A parasite is an organism that lives on or in a host and benefits at the host's expense.

How do protozoan parasites differ from bacteria?

Protozoa are single-celled eukaryotic organisms, while bacteria are prokaryotic.

What are some common parasitic diseases?

Common parasitic diseases include malaria, giardiasis, and toxoplasmosis.

What is the role of a vector in parasitism?

A vector is an organism that transmits a parasite to its host.

What is the life cycle of a parasite?

The life cycle of a parasite includes stages such as eggs, larvae, and adult forms.

What is zoonosis?

Zoonosis refers to diseases that are transmitted from animals to humans.

What are symptoms of bacterial infections?

Symptoms may include fever, inflammation, pain, and fatigue.

How can bacterial infections be treated?

Bacterial infections are typically treated with antibiotics.

What is the significance of vaccination in preventing bacterial diseases?

Vaccination helps the immune system recognize and fight specific bacteria before they can cause disease.

What is the role of lysozyme in the body's defense against bacteria?

Lysozyme is an enzyme that breaks down bacterial cell walls, helping to kill bacteria.

How can one prevent bacterial infections?

Preventative measures include hand washing, safe food handling, and vaccination.

What is nosocomial infection?

A nosocomial infection is an infection acquired in a healthcare setting.

What is the function of phagocytes?

Phagocytes are immune cells that engulf and digest pathogens.

How do bacteria acquire genetic diversity?

Bacteria can gain genetic diversity through mutation, transformation, transduction, and conjugation.

What role do bacteria play in the ecosystem?

Bacteria recycle nutrients, decompose organic matter, and participate in nitrogen fixation.

What is a virulence factor?

A virulence factor is a molecule produced by a pathogen that contributes to its ability to cause disease.

What is the purpose of Koch's postulates?

Koch's postulates are guidelines for linking specific pathogens to specific diseases.

What is the difference between symptomatic and asymptomatic infections?

Symptomatic infections show clinical signs, while asymptomatic infections do not.

What role do probiotics play in health?

Probiotics are beneficial bacteria that help maintain gut health and assist in digestion.

What is a chronic bacterial infection?

A chronic bacterial infection persists for an extended period of time and may be less acute.

What are the implications of antibiotic overuse?

Antibiotic overuse can lead to increased antibiotic resistance, making infections harder to treat.

What is the role of antibiotic susceptibility testing?

Antibiotic susceptibility testing determines which antibiotics will be effective against specific bacteria.

How does vaccination work to prevent bacterial diseases?

Vaccination stimulates the immune system to recognize and respond to specific bacterial antigens.