Skip to main content
Ch. 11 - Innate Immunity
Norman-McKay- Microbiology: Basic and Clinical Principles 2nd Edition
Norman-McKay2nd EditionMicrobiology: Basic and Clinical PrinciplesISBN: 9780137661619Not the one you use?Change textbook
All textbooksNorman-McKay 2nd EditionCh. 11 - Innate ImmunityProblem 4
Chapter 11, Problem 4

Which of the following would you expect to see in acute infection by a Gram-negative bacterium? Select all that apply.
a. Pyrexia
b. Decreased lymphocytes
c. Neutrophilic lymphocytosis
d. Decreased monocytes
e. Increased release of pro-inflammatory cytokines

Verified step by step guidance
1
Step 1: Understand the nature of acute infection by a Gram-negative bacterium. Gram-negative bacteria have an outer membrane containing lipopolysaccharides (LPS), which act as endotoxins and strongly stimulate the immune response.
Step 2: Recognize that pyrexia (fever) is a common systemic response to infection, especially due to the release of pyrogenic cytokines triggered by bacterial components like LPS.
Step 3: Recall that acute bacterial infections typically cause an increase in neutrophils (neutrophilia) rather than lymphocytes, so terms like 'neutrophilic lymphocytosis' need careful interpretation; lymphocytosis refers to increased lymphocytes, which is more common in viral infections.
Step 4: Consider the behavior of lymphocytes and monocytes during acute bacterial infections. Lymphocytes usually do not decrease significantly, and monocytes often increase or remain stable as they differentiate into macrophages to fight infection.
Step 5: Understand that pro-inflammatory cytokines such as TNF-alpha, IL-1, and IL-6 are released in increased amounts during acute Gram-negative bacterial infections, driving inflammation and systemic symptoms.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
3m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Host Immune Response to Gram-Negative Bacterial Infection

During an acute Gram-negative bacterial infection, the immune system activates innate defenses, including neutrophils and monocytes, to combat pathogens. This response often leads to fever (pyrexia) and increased production of pro-inflammatory cytokines, which help coordinate immune activity and inflammation.
Recommended video:
Guided course
03:31
Inflammatory Response Can damage the Host

Role of White Blood Cells in Infection

Neutrophils are the primary responders to bacterial infections, often increasing in number (neutrophilia). Lymphocytes typically respond more to viral infections, so lymphocyte counts may decrease or remain unchanged. Monocytes can increase as they differentiate into macrophages to clear infection sites.
Recommended video:
Guided course
3:43
2) Viruses Interfere with Antigen Presentation in Infected Cells

Pro-Inflammatory Cytokines in Acute Infection

Gram-negative bacteria release endotoxins (lipopolysaccharides) that stimulate immune cells to release pro-inflammatory cytokines like TNF-alpha and IL-1. These cytokines induce fever, recruit immune cells, and amplify inflammation, playing a critical role in the symptoms and progression of acute bacterial infections.
Recommended video:
Guided course
03:29
Acute Viral Infections
Related Practice
Textbook Question

Pick which statements are true, then correct all false statements, so they are also true.

a. Redness, pain, fever, and swelling characterize inflammation.

b. Granulocytes include monocytes and lymphocytes.

c. Pyrogens induce fever.

d. Adaptive and innate immune responses are completely independent from one another.

e. The innate immune responses occur faster than adaptive responses.

f. Monocytes are highly phagocytic cells.

g. Complement cascades share the same outcomes: opsonization, cytolysis, and fever.

Textbook Question

Which of the following would you not expect to see in the first stage of inflammation?

a. Histamine

b. Kinins

c. Macrophages

d. Increased blood vessel permeability

e. Eicosanoids

3
views
Textbook Question

Which of the following would most directly reduce fever? Select all that apply.

a. Limiting the number of circulating white blood cells

b. Reducing eicosanoid production

c. Inhibiting pyrogenic cytokines

d. Stimulating the action of prostaglandins

e. Administering antihistamines

2
views
Textbook Question

Which of the following would you expect to see increased in circulation in a patient suffering from allergies? Select all that apply.

a.

b.


c.

d.

e.

2
views
Textbook Question

Classify each defense as either first-line, second-line cellular, or second-line molecular:

Inflammation

Neutrophils

Skin

Antimicrobial peptides

Lysozyme

Stomach acid

Eosinophils

Fever

Complement proteins

Mucus

Iron-binding proteins

Phagocytosis

1
views
Textbook Question

The ____________ cascade of complement activation is initiated by antibodies. In contrast, the ____________ cascade is activated by a direct interaction with complement proteins, and the ____________ cascade is activated by MBL associating with a pathogen.

3
views