CORE Microbiology
43 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a characteristic change in the microbial population associated with metabolic disorders like obesity?

  • No change in microbial diversity
  • Decreased firmicutes and increased bacteroidetes
  • Increased diversity of microbial populations
  • Increased firmicutes and decreased bacteroidetes (correct)

Which of the following statements correctly describes Clostridium difficile infections?

  • They can lead to pseudomembranous colitis. (correct)
  • They are primarily Gram negative bacteria.
  • They cause infections that are harder to treat in an active state.
  • They are not associated with any gastrointestinal symptoms.

Which among the following is the treatment for Clostridium difficile infections?

  • Administration of antibiotics and nutritional supplements (correct)
  • Surgical intervention as the primary option
  • Antiviral medications
  • Increased intake of firmicutes-rich foods

What is a consequence of dysbiosis caused by Clostridium difficile?

<p>Sepsis-like symptoms and potential death (C)</p> Signup and view all the answers

What role does the gut have in relation to the brain as mentioned in the content?

<p>The gut influences brain activity and feelings. (C)</p> Signup and view all the answers

What type of bacteria was responsible for the Black Death?

<p>Gram negative bacteria (D)</p> Signup and view all the answers

Which of the following is a characteristic used for diagnosing bacteria?

<p>Morphology (A)</p> Signup and view all the answers

What defines a communicable disease?

<p>A disease that spreads through direct contact between hosts (D)</p> Signup and view all the answers

Which statement about eukaryotic and prokaryotic mRNA is correct?

<p>Prokaryotic mRNA can code for multiple proteins. (A)</p> Signup and view all the answers

Which type of disease is a result of microbial invasion or multiplication?

<p>Infectious disease (A)</p> Signup and view all the answers

What is the significance of antimicrobial resistance (AMR) in the context of infectious diseases?

<p>It complicates treatment options. (A)</p> Signup and view all the answers

Which of the following terms refers specifically to the study of the causes of disease?

<p>Disease aetiology (B)</p> Signup and view all the answers

What term describes a microbe as the cause of a disease?

<p>Microbial aetiology (C)</p> Signup and view all the answers

What type of microbiota is notably acquired at birth?

<p>Lactobacillus (B)</p> Signup and view all the answers

Which of the following bacterial types is commonly found in the oral cavity?

<p>Streptococcus (A)</p> Signup and view all the answers

What term describes the imbalance of types of organisms in the body?

<p>Dysbiosis (A)</p> Signup and view all the answers

Which condition is associated with the Mycobiome and caused by Malasezzia furfur?

<p>Pityriasis versicolor (B)</p> Signup and view all the answers

Which of the following is not associated with the GI tract?

<p>Aspergillus (A)</p> Signup and view all the answers

What is the primary environment for the growth of Candida species?

<p>Wet and moist (C)</p> Signup and view all the answers

In which location would you find Lactobacillus instead of Prevotella?

<p>Vagina (D)</p> Signup and view all the answers

What is one of the most common forms of inflammatory bowel disease (IBD)?

<p>Crohn's disease (B), Ulcerative colitis (D)</p> Signup and view all the answers

Which type of microbial is predominantly found in dry environments?

<p>Aspergillus (C), Malasezzia (A)</p> Signup and view all the answers

Which microbial balance indicates a potential health issue?

<p>Dysbiosis (B)</p> Signup and view all the answers

What is the primary function of the bacterial capsule?

<p>Providing immune resistance (D)</p> Signup and view all the answers

Which characteristic distinguishes Gram positive and Gram negative bacteria in terms of their cell wall structure?

<p>Gram positive has a thick peptidoglycan wall (A)</p> Signup and view all the answers

What role does fimbriae play in bacterial cells?

<p>Attachment to surfaces (A)</p> Signup and view all the answers

What is the defining structural component of fungi's cell wall?

<p>Chitin (A)</p> Signup and view all the answers

What is true regarding the classification of viruses?

<p>Based on disease vectors and location (A)</p> Signup and view all the answers

What common structural feature do Gram negative bacteria possess that Gram positive do not?

<p>Multiple membranes (B)</p> Signup and view all the answers

Which type of bacteria are pili specifically associated with?

<p>Only Gram negative (D)</p> Signup and view all the answers

Which statement correctly describes the life cycle of a virus?

<p>It relies on the host's cell machinery. (A)</p> Signup and view all the answers

What does the term 'virion' refer to in virology?

<p>The ineffective form of the virus (A)</p> Signup and view all the answers

What factor limits the growth of fungi when comparing it to bacteria?

<p>Lower pH levels (C)</p> Signup and view all the answers

What phase of bacterial growth occurs when adaptation to the environment is complete and optimal conditions for growth are present?

<p>Log phase (A)</p> Signup and view all the answers

Which type of medium allows for the growth of a wide array of bacteria?

<p>General growth medium (B)</p> Signup and view all the answers

What is the primary role of microbiota in the human body?

<p>Contributing to immune development (A)</p> Signup and view all the answers

Which of the following statements about anaerobes is correct?

<p>Anaerobes do not require oxygen for growth. (D)</p> Signup and view all the answers

How does the microbiota contribute to the maintenance of pH in the body?

<p>By fermenting sugars (C)</p> Signup and view all the answers

What aspect of bacterial growth phases is represented by the stationary phase?

<p>Toxic product accumulation (B)</p> Signup and view all the answers

What is the estimated proportion of body weight that microbiota constitutes?

<p>1-3% (C)</p> Signup and view all the answers

Which bacteria are often found in dry areas of the human body?

<p>Staphylococcus epidermidis (C)</p> Signup and view all the answers

What characteristic distinguishes the death phase of bacterial growth?

<p>Toxin levels and nutrient depletion lead to cell death. (C)</p> Signup and view all the answers

What is a significant effect of microbiota on human health?

<p>Stimulates immune system maturation (C)</p> Signup and view all the answers

Flashcards

Pathogenesis

The origination and development of a disease. It describes how a disease begins and progresses.

Molecular pathogenesis

The study of the molecules involved in disease progression. It focuses on the specific mechanisms at the molecular level.

Microbial pathogenesis

The ability of microbes to cause infection. This refers to the mechanisms by which microbes harm their host.

Host-Pathogen Interaction

The relationship between a host and a pathogen. It explains how microbes survive and thrive within a host.

Signup and view all the flashcards

Disease Aetiology

The study of the causes of a disease. It focuses on identifying the factors that lead to a disease.

Signup and view all the flashcards

Microbial Aetiology

The microbe is the direct cause of a disease. It identifies specific microbes as the source of a disease.

Signup and view all the flashcards

Monocistronic

A gene coding for only one protein. This is characteristic of eukaryotic mRNA.

Signup and view all the flashcards

Polycistronic

A gene coding for multiple proteins. This is characteristic of prokaryotic mRNA.

Signup and view all the flashcards

Introns in prokaryotes

Prokaryotes do not have introns in their DNA. This is because introns are non-coding sequences and would be inefficient to maintain. Prokaryotes prioritize efficiency.

Signup and view all the flashcards

Bacterial Capsule

A protective outer layer of polysaccharides (sugars) found in some bacteria. It provides resistance to the immune system and helps with moisture absorption.

Signup and view all the flashcards

Bacterial Cell Wall

A rigid structure surrounding the bacterial cell membrane, primarily composed of peptidoglycan. It determines the shape of the bacteria, controls the passage of large molecules, and helps resist osmotic pressure.

Signup and view all the flashcards

Gram-Positive Bacteria

Bacteria with a thick peptidoglycan layer and a single cell membrane. They stain purple with the Gram stain.

Signup and view all the flashcards

Gram-Negative Bacteria

Bacteria with a thin peptidoglycan layer and two cell membranes. They stain pink with the Gram stain.

Signup and view all the flashcards

Flagella

Long, whip-like appendages used for bacterial movement. They are made of the protein flagellin.

Signup and view all the flashcards

Fimbriae

Short, bristle-like appendages that help bacteria attach to surfaces. They are made of the protein fimbrillin.

Signup and view all the flashcards

Pili

Hollow, filamentous appendages that help bacteria with genetic exchange and movement. They are made of the protein pilin.

Signup and view all the flashcards

Viruses

Acellular parasites that require host cells for replication. They have either a helical or icosahedral shape.

Signup and view all the flashcards

Fungi

Eukaryotic organisms that grow as hyphae and have cell walls composed of chitin. They are important decomposers and can be found in many habitats.

Signup and view all the flashcards

What is Microbiota?

The diverse community of microorganisms (mainly bacteria) that naturally reside in a particular environment, like your gut.

Signup and view all the flashcards

How does Microbiota change throughout life?

The composition of microbiota changes from birth through adulthood. We acquire new microbes, and some die out over time.

Signup and view all the flashcards

Gram-positive cell wall

A thick layer of peptidoglycan that surrounds the cell membrane, providing structural integrity and resistance to osmotic pressure.

Signup and view all the flashcards

What is Mycobiome?

The collection of fungal microorganisms that reside in a particular environment, like your skin.

Signup and view all the flashcards

Bacterial heterotroph

Bacteria that cannot produce their own food and rely on consuming organic compounds for energy and growth.

Signup and view all the flashcards

Where do Candida, Malassezzia and Aspergillus thrive?

Candida: wet/moist areas (vagina), Malassezzia: dry areas, Aspergillus: dry and acidic environments.

Signup and view all the flashcards

Lag phase of bacterial growth

The initial phase where bacteria adapt to their new environment, preparing for rapid growth.

Signup and view all the flashcards

Log phase of bacterial growth

The phase of exponential growth, where bacteria reproduce at the fastest rate possible under optimal conditions.

Signup and view all the flashcards

What is Pityriasis Versicolor?

A skin infection caused by Malassezzia furfur fungus, characterized by scaly skin and discolored patches.

Signup and view all the flashcards

What is Co-presence and Exclusion in Microbiome?

Some microorganisms thrive together (co-presence) while others compete for space, with only one prevailing (exclusion).

Signup and view all the flashcards

Stationary phase of bacterial growth

The phase where growth slows down due to limited nutrients, oxygen, and accumulation of waste products.

Signup and view all the flashcards

Death phase of bacterial growth

The phase where bacteria die due to depleted resources and the accumulation of toxic waste products.

Signup and view all the flashcards

What are some examples of Co-presence and Exclusion?

In the mouth, Streptococcus and Tannerella can co-exist. But in the vagina, either Prevotella or Lactobacillus dominate.

Signup and view all the flashcards

General growth medium

A type of culture medium that supports the growth of a wide variety of bacteria.

Signup and view all the flashcards

What is Dysbiosis?

Imbalance or disruption in the composition of microorganisms in the body, often leading to health issues.

Signup and view all the flashcards

How is Dysbiosis linked to GI Tract Disorders?

Dysbiosis in the gut is associated with inflammatory bowel disease (IBD), like Crohn's disease and ulcerative colitis.

Signup and view all the flashcards

Selective growth medium

A type of culture medium designed to allow only specific types of bacteria to grow.

Signup and view all the flashcards

Differential growth medium

A type of culture medium that differentiates between different types of bacteria based on their growth characteristics.

Signup and view all the flashcards

Microbiota

The collection of microorganisms living in a specific ecological niche, such as the human body.

Signup and view all the flashcards

Gut Microbiome and Diseases

The composition and function of the gut microbiome can be altered in various diseases, including inflammatory bowel disease (IBD), colorectal cancer, obesity, type 2 diabetes, and some CNS disorders.

Signup and view all the flashcards

C. difficile Infection

Clostridium difficile (C. diff) is a bacterium that causes severe diarrhea and inflammation in the colon, leading to conditions like pseudomembranous colitis and sepsis.

Signup and view all the flashcards

Dysbiosis

An imbalance in the gut microbiome, often characterized by a decrease in beneficial bacteria and an increase in harmful bacteria.

Signup and view all the flashcards

C. difficile Diagnosis

Diagnosing C. difficile infection can be challenging and often involves testing like breath and blood tests, imaging scans, and stool analysis.

Signup and view all the flashcards

C. difficile Treatment

Treatment for C. difficile infection typically involves antibiotics and might involve nutritional supplements like vitamin B12 to replenish lost nutrients.

Signup and view all the flashcards

Study Notes

Microbiology

  • Microbiology is the study of microorganisms, including bacteria, archaea, viruses, fungi, and protozoa.
  • Prokaryotic pathogens include bacteria.
  • Eukaryotic pathogens include fungi, protozoa, and parasitic worms.
  • Infectious diseases are a leading cause of death, and Antimicrobial Resistance (AMR) is a critical concern.

Prokaryotic & Eukaryotic Pathogens

  • Pathogenesis is the origination and development of a disease.
  • Molecular pathogenesis studies molecules involved in disease.
  • Microbial pathogenesis is the ability of microbes to cause infection.
  • Host-pathogen interaction describes how microbes survive in hosts.
  • Disease etiology studies the causes of diseases, while microbial etiology specifically looks at microbes as causes.
  • Microbial diseases are illnesses caused by microorganisms.
  • Infectious diseases are illnesses caused by microbial invasion.
  • Communicable diseases are ones that spread among hosts.
  • Contagious diseases are easily spread between hosts.

Prokaryotes vs. Eukaryotes

  • Prokaryotes (bacteria & archaea) are simple, single-celled organisms without a nucleus or membrane-bound organelles.
  • Eukaryotes (animals, plants, fungi, and protists) are complex, single-celled or multicellular organisms with a nucleus and membrane-bound organelles.
  • Key structural differences include cell size, membrane composition, ribosome structure, DNA organization, presence of organelles, and cell wall structure.
  • Bacterial shape categories include bacilli, cocci, ovococci, spirillum, spirochaetes, and vibrio.
  • Bacterial arrangement categories include strepto, staphylo, diplococci.
  • Prokaryotes have polycistronic gene expression, meaning one mRNA molecule can code for multiple proteins, whereas eukaryotes have monocistronic gene expression, where one mRNA molecule codes for a single protein.
  • Eukaryotic mRNAs are shorter, which affects protein-coding capacities.
  • Prokaryotic genomes are usually more compact, and eukaryotes tend to have larger, more complex genomes.
  • Eukaryotes have introns in their genes (non-coding sections), not present in prokaryotes. Exons are the coding regions.

Bacterial Structures

  • Capsules are polysaccharide layers that aid in immune resistance and moisture absorption.
  • Cell walls determine bacterial shape. They are composed of sugars linked by amino acids.
  • Flagella allow movement (motility).
  • Fimbriae are short, filamentous proteins that promote bacterial attachment to surfaces.
  • Pili are longer, hollow structures involved in cell interactions and genetic exchange.

Viruses

  • Viruses are acellular entities with limited metabolic capabilities. They depend on host cells for replication.
  • Viral structure often involves an outer protein capsid surrounding genetic material (DNA/RNA).
  • Viral shapes include helical and icosahedral symmetries.

Ecological Relations

  • Microbes can form beneficial, detrimental, and commensal relationships with their hosts.
  • Beneficial relationships include mutualistic interactions.
  • Detrimental relationships include parasitic and pathogenic interactions.

Fungi

  • Fungi are eukaryotes that reproduce through binary fission and as hyphae.
  • Their cell walls are made of chitin.
  • They require a lower pH than bacteria to grow.

Protozoa

  • Protozoa are single-celled eukaryotes, often categorized by how they move (pseudopodia, flagella, cilia).
  • They are found in diverse environments and some cause infection.

The Human Microbiota

  • The human microbiota is the collection of microorganisms living in and on the human body.
  • Significant microbial communities exist in several body parts (mouth, gut, skin).
  • Microbiota are beneficial for diverse factors, influencing immune development, nutrient production, and antimicrobial production.
  • Their numbers and types vary based on factors such as diet, age, and environment.
  • Dysbiosis is an imbalance within beneficial and pathogenic communities, which can lead to disease conditions in the human body.
  • Several factors can potentially disrupt a balance or potentially predispose dysbiosis, including antibiotics, aging, changes in the nutrition, environment, or host immune status.

Bacterial Growth Phases

  • Bacterial growth is observed in four phases: lag phase, log phase, stationary phase, and death phase.
  • The optimal conditions vary across bacterial species.

Classification

  • Gram-positive bacteria are stained different colors from gram-negative bacteria depending on their cell wall structure (thick vs. thin peptidoglycan layer).
  • Bacteria are classified and identified by various methods, including their shape, arrangement, metabolic characteristics, and genetic makeup.
  • Different types of media/environments can be used for bacterial growth and differential differentiation.

Diagnostics

  • Diagnosis of bacterial, fungal, and viral infections commonly relies on observations of shape and arrangements of microbes as part of microscopy and other more highly specialized testings for diagnostics.
  • Biochemical properties.
  • Detailed genetic makeup (specific gene sequences).

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Microbiology Core Notes Year 1 PDF

Description

Test your knowledge of microbiology with this quiz focusing on prokaryotic and eukaryotic pathogens. Explore concepts such as pathogenesis, microbial diseases, and the role of microorganisms in infectious diseases. Understand the significance of antimicrobial resistance and host-pathogen interactions.

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser