opportunism Flashcards
(19 cards)
What is a pathogen?
A pathogen is a microbe that can cause disease.
Pathogens include bacteria, viruses, fungi, and parasites.
What are opportunistic infections?
Infections that occur when the immune system is compromised or when normal flora is disturbed.
These infections often exploit breaches in the body’s defenses.
What makes a microbe pathogenic?
Factors include:
* Adherence and colonization
* Infectious process
* Protection against host defenses
List three methods by which microorganisms cause disease.
- Contact or enter host cells and directly cause cell death
- Release toxins that kill cells at a distance
- Release enzymes that degrade tissue components
What is the role of innate immune defense?
- Skin
- Mucus membranes
- Reflexes
- Normal commensal bacteria
- Phagocytes
- Complement system
What is the role of adaptive immunity?
- T-cells
- B-cells (Antibodies)
What are the underlying causes of opportunistic infections?
- Breaching barriers
- Failure of immune defenses (immunodeficiency)
- Disturbances in the normal flora
Define wound colonization.
The presence of replicating microorganisms adherent to the wound in the absence of injury to the host.
What characterizes chronic wounds?
Chronic wounds are characterized by their failure to heal and remain stuck in a non-healing state for many months or even years.
List the most common types of chronic wounds.
- Pressure ulcers/sores
- Diabetic ulcers
What is SCID?
Severe combined immunodeficiency, characterized by the loss of adaptive immune response.
How does HIV affect the immune system?
HIV infection leads to destruction of CD4+ T-cells, resulting in immunosuppression and acquired immunodeficiency syndrome (AIDS).
What is bacterial vaginosis (BV)?
An opportunistic infection characterized by disruption of the normal vaginal microbiota.
What factors can disturb the normal vaginal microbiota?
- Use of antibiotics
- Hormonal contraceptives
- Vaginal lubricants
- Antimicrobial hygiene products
What are the consequences of bacterial vaginosis?
- Increased vulnerability to STIs and HIV
- Increased risk of upper genital tract infection and pelvic inflammatory disease
- Poor pregnancy outcomes
What is the dominant flora in the vaginal microbiota of healthy individuals?
Lactobacillus spp.
What is the role of lactic acid in the vaginal microbiota?
Helps maintain a pH of 3.8 to 4.2, limiting the growth of pathogenic microorganisms.
What are opportunistic pathogens?
Pathogens that can cause infection when there is a breach in barrier defense, an impaired immune system, or a disturbance in normal microbiome.
Fill in the blank: The microbial flora in wounds appear to change over time, with _______ predominating in early acute wounds.
Normal skin flora
