Sources and Types of Infection | Factors affecting growth of Microbes | Cycle of Transmission of Infection, Reaction of Body to Infection | Mechanism of Resistance and Collection of Specimen | Mock Test | Staff Nurse

Sources and types of infection, factors affecting growth of microbes, cycle of transmission of infection, reaction of body to infection, mechanism of resistance and collection of specimen.

Infections can originate from various sources such as humans, animals, water, food, soil, and air. Types of infection include bacterial, viral, fungal, and parasitic infections. Factors affecting microbial growth include temperature, moisture, oxygen, pH, and nutrients. The cycle of transmission involves an infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, and a susceptible host. The body's reaction to infection includes inflammation, fever, and immune responses. Mechanisms of resistance involve natural barriers (skin, mucosa), immune responses (antibodies, white blood cells), and acquired immunity. Specimen collection (like blood, urine, sputum) must be done aseptically to identify pathogens accurately and guide treatment.

Time: 15:00

An infection that develops from a patient's own normal flora that has spread to an abnormal site in the body is called:

[a] An exogenous infection

[b] A nosocomial infection

[c] An endogenous infection

[d] A systemic infection

Which environmental factor is most critical for the growth of almost all microbes?

[a] Darkness

[b] High pressure

[c] Dryness

[d] Moisture

In the cycle of transmission, the place where a microorganism normally lives and reproduces (e.g., a human, an animal, or the soil) is called the:

[a] Portal of exit

[b] Mode of transmission

[c] Susceptible host

[d] Reservoir

Which of the following is a classic sign of a localized inflammatory response to infection?

[a] A high white blood cell count (leukocytosis)

[b] Redness, swelling, and pain at the site

[c] A high fever

[d] Nausea and vomiting

A person develops lifelong immunity after recovering from chickenpox. This is an example of what type of immunity?

[a] Artificially acquired active immunity

[b] Naturally acquired passive immunity

[c] Naturally acquired active immunity

[d] Artificially acquired passive immunity

What is the most critical principle to follow when collecting any microbiological specimen to ensure accurate results?

[a] Collect the largest sample possible.

[b] Collect the specimen after starting antibiotics.

[c] Use aseptic (sterile) technique to avoid contamination.

[d] Label the specimen with only the patient's room number.

An infection that spreads throughout the body via the bloodstream is known as a:

[a] Local infection

[b] Chronic infection

[c] Systemic infection

[d] Secondary infection

Most bacteria that are pathogenic to humans grow best at normal body temperature. These microbes are classified as:

[a] Thermophiles (heat-loving)

[b] Mesophiles (moderate-temperature-loving)

[c] Psychrophiles (cold-loving)

[d] Halophiles (salt-loving)

A healthcare worker transmits a pathogen between two patients without washing their hands. The hands of the healthcare worker are acting as the:

[a] Portal of entry

[b] Reservoir

[c] Portal of exit

[d] Mode of transmission (indirect contact)

The body's first line of defense against infection, which is non-specific, includes:

[a] Antibodies

[b] T-cells and B-cells

[c] Intact skin, mucous membranes, and cilia

[d] The inflammatory response

To obtain a "clean-catch" or midstream urine specimen, the patient is instructed to:

[a] Collect the very first stream of urine in the morning.

[b] Collect a 24-hour urine sample in a large jug.

[c] Clean the perineal area, begin urinating, stop, and then collect the middle portion of the stream.

[d] Collect the very last few drops of urine.

A contaminated object such as a used needle, a toy, or a dirty doorknob that can transmit a pathogen is called a:

[a] Vector

[b] Fomite

[c] Reservoir

[d] Droplet

Bacteria that require oxygen to grow are called:

[a] Obligate anaerobes

[b] Facultative anaerobes

[c] Aerobes

[d] Microaerophiles

Which of the following is an example of a portal of entry for a pathogen?

[a] A sneeze from an infected person

[b] A break in the skin from a cut or wound

[c] An infected person's blood

[d] A mosquito

The primary purpose of a fever in response to an infection is to:

[a] Make the person feel more comfortable.

[b] Increase the person's heart rate.

[c] Inhibit the growth of pathogens and enhance the immune response.

[d] Cause dehydration to flush out the toxins.

When collecting a wound culture, the specimen should ideally be taken from:

[a] The pus that has drained onto the dressing.

[b] The intact skin surrounding the wound.

[c] A swab of the scab covering the wound.

[d] The clean, central area of the wound bed after removing surface debris.

Transmission of a pathogen via coughing or sneezing, where infectious particles travel a short distance (less than 3 feet), is known as:

[a] Airborne transmission

[b] Droplet transmission

[c] Vector-borne transmission

[d] Direct contact transmission

Which of the following would make a person a more "susceptible host"?

[a] Being fully vaccinated.

[b] Having a healthy, balanced diet.

[c] Being elderly or having a compromised immune system.

[d] Practicing good hand hygiene.

An increase in the number of white blood cells (leukocytes) in the blood in response to an infection is termed:

[a] Anemia

[b] Leukopenia

[c] Leukocytosis

[d] Thrombocytopenia

A baby receiving antibodies from its mother through breast milk is an example of:

[a] Artificially acquired active immunity

[b] Naturally acquired active immunity

[c] Artificially acquired passive immunity

[d] Naturally acquired passive immunity

Handwashing is the single most effective way to break the chain of infection, primarily by interrupting the:

[a] Infectious agent

[b] Reservoir

[c] Susceptible host

[d] Mode of transmission

For a sputum specimen to be useful for diagnosing a lower respiratory infection, it must contain:

[a] Mostly saliva from the mouth.

[b] A large amount of post-nasal drip.

[c] Secretions from deep within the lungs, obtained by a deep cough.

[d] A mix of food particles and oral flora.

An example of a source of exogenous infection is:

[a] A patient's own E. coli from their intestine causing a urinary tract infection.

[b] Inhaling influenza virus from a contaminated environment.

[c] A patient's own Staphylococcus aureus from their skin causing a wound infection.

[d] Candida albicans from the mouth overgrowing after antibiotic use.

The body's ability to produce its own antibodies in response to a vaccine is an example of:

[a] Naturally acquired active immunity

[b] Naturally acquired passive immunity

[c] Artificially acquired passive immunity

[d] Artificially acquired active immunity

Why is it important to transport a specimen to the laboratory promptly?

[a] To allow time for the patient's name to be written on the container.

[b] To give the doctor time to review the request.

[c] To prevent the overgrowth of contaminating microbes or the death of fastidious pathogens.

[d] To ensure the specimen is at room temperature.