Microbiology

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main criterion for classifying microorganisms into ACDP Categories?

The potential for genetic modification

Size of the microorganism

Growth rate of the microorganism

Severity of disease and availability of treatment (correct)

ACDP Category 2 organisms are characterized by which of the following?

There is no treatment available for infections caused by them.

They can cause severe human disease but cannot spread in the local population.

They can cause human disease and may present a hazard to the environment. (correct)

They are generally non-pathogenic and pose minimal hazards.

Which facility classification corresponds to ACDP Category 1 organisms?

BSL-0 facilities requiring no special precautions

BSL-1 facilities with general protective equipment (correct)

BSL-3 facilities requiring high-level containment

BSL-2 facilities with specific training requirements

Which of the following is NOT a characteristic of BSL-2 facilities?

Unrestricted access to laboratory areas Signup and view all the answers

Under what condition might the general rule of thumb regarding BSL and ACDP level not apply?

If effective vaccination is available Signup and view all the answers

Which of the following statements accurately describes a BSL-4 facility?

Organisms must be handled in a class 3 cabinet. Signup and view all the answers

Which of the following pathogens is classified as a Category 4 organism?

Ebola virus Signup and view all the answers

What is a key characteristic of BSL-3 facilities?

All work is done under negative air pressure. Signup and view all the answers

Which classification method involves the genetic makeup of organisms?

Genotype Signup and view all the answers

Which of the following features is NOT associated with ACDP Category 4 organisms?

Effective treatment options are readily available. Signup and view all the answers

What type of mutation involves a single nucleotide change in DNA?

Point mutation Signup and view all the answers

Which of the following best describes phylogenetics?

The study of evolutionary relationships among biological entities. Signup and view all the answers

What does MSA stand for in the context of DNA sequence analysis?

Multiple Sequence Alignment Signup and view all the answers

Which of the following statements is true regarding phylogenetic trees?

Rooted trees illustrate both how organisms are related and their ancestral lineage. Signup and view all the answers

What does a high percentage of similarity between two bacterial strains in a genetic distance analysis indicate?

They are closely related with a similar genetic makeup. Signup and view all the answers

Which of the following methods is least likely to be used for constructing phylogenetic trees?

Gene insertion and deletion tracking Signup and view all the answers

What is a potential outcome of gene mutations in bacteria?

Enhanced resistance to antibiotics. Signup and view all the answers

How are clades within phylogenetics defined?

By clusters of organisms sharing similar DNA or protein sequences. Signup and view all the answers

What is the primary focus of biological systematics?

Assessing how life changes over time Signup and view all the answers

Which of the following correctly distinguishes cellular microorganisms from acellular ones?

Cellular microorganisms can reproduce independently while acellular cannot Signup and view all the answers

Which classification system is NOT traditionally used for acellular entities?

Linnaean system Signup and view all the answers

In which of the following groups do viruses belong, according to the classification of biological entities?

Acellular organisms Signup and view all the answers

Who contributed to the classification system by proposing 5 kingdoms?

Whittaker Signup and view all the answers

What is a defining characteristic of prions?

They are misfolded proteins that do not reproduce Signup and view all the answers

Which of the following ranks comes directly before the genus in taxonomic classification?

Family Signup and view all the answers

What is the structural basis for the classification of viruses?

Their nucleic acid type and phenotype Signup and view all the answers

Which domain includes organisms that possess a nuclear membrane?

Eukaryota Signup and view all the answers

What did Woese contribute to the classification of biological entities?

The introduction of the three-domain classification system Signup and view all the answers

Which of the following best defines a species in the context of living organisms?

A group of organisms capable of interbreeding, even if geographically isolated. Signup and view all the answers

What is meant by a 'strain' in microbiology?

A genetic variant of a bacterial species differing slightly from its members. Signup and view all the answers

Which classification provides the least detailed information about an organism?

Phenotype classification Signup and view all the answers

In microbiology, serotypes are defined by what characteristic?

Distinct variations in cell surface antigens within a species. Signup and view all the answers

Which statement about vertical and horizontal gene transfer is true?

Horizontal transfer allows for the acquisition of genetic information from non-parental organisms. Signup and view all the answers

Which method is NOT typically associated with genotype classification?

Phenotype observation Signup and view all the answers

What is the primary purpose of whole genome sequencing in microbiology?

To determine the complete DNA sequence of an organism at a single time. Signup and view all the answers

What is the significance of 95% genome sequence similarity in bacterial species classification?

It is a threshold for defining bacterial species. Signup and view all the answers

Which of the following biological traits is NOT considered in phenotype classification?

Genetic makeup of the organism Signup and view all the answers

Which specific antigens are utilized to classify serotypes within the Salmonella genus?

Surface oligosaccharides and flagellar proteins Signup and view all the answers

Study Notes

Microbial Classification

The MPharm programme includes a module on microbial classification
Learning outcomes include describing differences between cellular and acellular microorganisms, the main taxonomic groups and their features, and microbial classification with examples
Biological systematics studies how life changes over time and relates organisms to one another
Taxonomy defines systems using shared characteristics
Classification arranges organisms into groups
Nomenclature assigns names
Living things can be divided into cellular and acellular entities

Classification of Biological Entities

Biological entities are either cellular or acellular
Cellular entities are further subdivided into Eukarya, Archaea, and Bacteria
Acellular entities include viruses, viroids, virusoids, and prions

The Tree of Life

The tree of life illustrates evolutionary relationships among organisms
The tree displays a branching structure reflecting evolutionary lineages
Bacteria and Archaea represent distinct domains of life, separate from the Eukarya domain

Development of Classification Systems

Various scientists have contributed to the development of classification systems
Historical examples include Linnaeus, Haeckel, Chatton, Whittaker, and Woese
Their contributions led to the evolution of understanding living systems overtime

Taxonomic Ranks

Domain, Phylum, Class, Order, Family, Subfamily, Genus, and Species are used to formally identify and classify life
The example provided classifies Homo sapiens (humans) and Escherichia coli bacteria
Examples of species are the tiger and lion, which can interbreed
A species is a group of organisms that can interbreed. This also applies to organisms that do not reproduce sexually
Strains are genetic variants within a species.
The characteristics, methods, and examples for classifying organisms using phenotypes, serotypes, and genotypes are mentioned.

Phenotype Classification

Morphology: Cell shape (bacilli or cocci), cell structure (gram staining). Examples given include bacteria.
Biochemistry: Enzyme production, transport proteins. Examples given include testing various enzymes
Life cycle: Vegetative or spore formation. Examples provided may vary.
Ecological niche: Temperature (thermophile, psychrophile).
Interactions with other organisms: Susceptibility to bacteriophages.
Pathogenicity: Ability to cause disease

Serotype Classification

Serotype: Distinct variations of cell surface antigens within a species. Examples given include Salmonella and Vibrio cholerae
O and H antigens are used for identification.

Genotype Classification

Genotype: The part of the genetic makeup of a cell determining characteristics (phenotype)
Genomics, PCR, base composition, nucleic acid sequencing, 16S rRNA, whole genome sequencing. Examples shown may vary.
Some species can be classified upon their DNA, or protein sequences, or genomic makeup
Whole genome sequencing provides complete DNA sequencing at one time
Bacterial species can be defined when genomes share at least 95% identical sequences.

Vertical and Horizontal Gene Transfer

Vertical transmission: Genetic information passed from parent to offspring
Horizontal transmission: Genetic material acquired from a different organism, not a biological parent.

Whole Genome Sequencing

Determines the full DNA sequence
Shows genes present or absent
Helps identify mutations, insertions, and deletions, and potentially identify horizontal gene transfer events.

Visualising Genotypes: Phylogenetics

Phylogenetics studies evolutionary relations amongst organisms
Phylogenetic trees can be rooted or unrooted
Rooted trees infer the most recent common ancestor, whereas unrooted trees only show evolutionary relationships without inferring a common ancestor.
Multiple sequence alignments (MSAs) can be generated on DNA or protein sequences of biological entities, and these trees can be based on the genetic distance of the MSA.

Practical Application of Classification: Biosafety

Microorganisms are categorized by the Advisory committee on Dangerous Pathogens (ACDP) into 4 levels.
Organisms categorized by the level of hazard that they pose to humans or the environment.
Biosafety Levels (BSLs) determine the appropriate safety precautions and laboratory facilities.
BSL-1 facilities require only general protective equipment, hand washing, and sterilization of materials.
BSL-2 requires all of BSL-1 precautions plus highly regulated design, procedures, trained personnel, restricted access to laboratory, and work can be performed in BSL cabinets.
BSL-3 facilities require enhanced conditions for BSL-2 and additional approvals for some pathogens
BSL-4 requires highly trained personnel, specific PPE, negative air pressure, and other strict safety measures for especially dangerous pathogens.

Studying That Suits You

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

Description

This quiz tests your knowledge on the classification of microorganisms according to ACDP categories and BSL levels. Questions cover key characteristics, facility classifications, and mutation types related to various organisms. Perfect for microbiology students and professionals.

Microbiology_2

Choose a study mode