Microbiology unit 4 Vocab

Microbial Growth Control, Antimicrobial drugs, Microbial Mechanisms of Pathogenicity, & Disease & Epidemiology

Biological Safety Levels (BSL)

Rate the lab not the disease

Potential risk to lab workers and community

BSL 1

Low Risk - Standard like PPE

BSL 2

Moderate Risk - Restricted access, biosafety cabinets 

BSL 3

Potentially lethal - Special Ventilation, Respirators

BSL 4

Deadly- Full body suits, Isolated Facility 

Dry Heat Sterilization

Putting it through fire(Flaming inoculating tools)

Moist-Heat Sterilization (Autoclave)

High pressure steam 

• Gravity Displacement - remove air left with just the steam 

• PreVacuum sterilizers

Retort

Large scale industrial autoclaves

Pasteurization

uses heat to kill harmful microorganisms in food and beverages, typically involving heating to specific temperatures for a set period of time.

Controls microbes to get extended shelf life

HTST High temperature short time 

-72 degrees for 15 seconds

-Maintains food quality

UHT Ultra High Temperature 

-138 degrees for 2 seconds 

-Makes it taste different 

-Stored for several month

Desiccation (Drying)

High salt sugar concentration used to preserve food by removing moisture, reducing microbial growth but may not kill all microbes.

Lyophilization

Lyophile is a solvent loving substance (freeze dried foods)

Radiation (Ionizing and Non-Ionizing) 

Ionizing

Non-Ionizing 

Ultra violet light low energy, poorly penetrating

Filtration

Physically separating by using a porous medium.

-Commonly used in water treatment and air purification.

-HEPA Filters

Death Time (TDT)

Time needed to kill all microorganisms in a sample at a given temperature

Death Point (TDP)

Minimum temp that achieves 100% bacterial death in 10- minutes

Phenolics (Disinfectant)

Contains phenol but are less toxic.

Denatures Proteins & Disrupts Membranes 

• EX listerine, lysol, pHisoHex

Heavy Metal

Compounds that contain metals which can inhibit microbial growth by disrupting cellular functions.

SIlver

Wounds, antibiotics, cathheters/bandages

Copper

Algicide , pots for storing water

Zinc

Mouthwashes,lotions,ointments,powders,shampoos

Copper, Nickel & Zinc Coatings

Inhibit microbes from growing on that surface

Halogens

“Salt loving / generate salt”

Iodine

Oxidizes molecules:Proteins nucleotides and fatty acids

• Iodophor-

  • Povidone- 

    • Betadine- A brand for topical antisepsis before incision

• Bacteriostatic

  • Improves Calcium 

  • Fluorosis(concern) Cosmetic Issue due to excessive fluoride

Fluorine

Bacteriostatic

• Improves Calcium 

• Fluorosis(concern) Cosmetic Issue due to excessive fluoride

Chlorine Chemicals (Disinfectant)

Hypochlorous acid 

Hypochlorite

Chlorine Bleach

Alcohols

Denature proteins and disrupt membranes

Surfactants

Major ingredient in soaps and detergents

-When a fetus is viable outside of the mother it has surfactants

Soaps

-NonSynthetic

-Does not kill or inhibit microbial growth but helps to lift dirt and bacteria from surfaces.

-Salts of amphipathic long chain fatty acids  

Detergents

Synthetic

Bisbiguanides

-Lymphophilic

-Cationic Antiseptics that Disrupt microbial cell membranes

Alkylating Agents

Alkyl groups added into biological molecules, leading to cell damage and death.

EXAMPLES:

• Formaldehyde

• Glutaraldehyde

• O-phthaladehyde

• Ethylene oxide

• Beta-propionolactone

Peroxygens

-Strong oxidizing agents

-Form free radicals that are used as disinfectants and antiseptics.

Supercritical Fluids

-Forms carbonic acid (sterilizes)

-Nonreactive,nontoxic,nonflammable

Organic Acid & Salt Chemical Food Preservatives

-Sorbic Acid works best at low pH

-Benzoic Acid works best at low pH

-Propionic acid works best at high pH

Sulfur Dioxide & Nitrite Chemical Food Preservatives

-Sulfur Dioxide- prevents browning by forming sulfites

-Nitrites- stop c. botulism and preserve color

Ntural Chemical Food Preservatives

-Nisin - disrupts cell wall formation

• Made by lactococcus Lactis

-Natamycin - Antifungal macrolide 

• Made by Streptomyces natalensis

-cide/-cidal Suffixes

Kills the targeted microorganism

-static/-stat Suffixes

Stop Growth, allows immune system to do the heavy lifting

Microbial Death Curves

Tracks organisms death over time and provides insight into the effectiveness of antibacterial agents.

D-values 

Time needed to kill 90% of microbes

-lower=Stronger disinfection

-higher=Deteriorating disinfection

Sterilization

Completely kill vegetative cells, endospores, viruses

Disinfection

Inactivates microbes on surface of a non-living object or tissue, reducing their viability.

-Not Sterile

Antiseptics

Safe for living tissue

Degerming

Scrubbing skin to greatly reduce germs 

• Hand Washing, alcohol swab at injection or surgical site preparation.

Sanitization

Reducing the number of microbes to a safe level as deemed safe for public health standards.

- Often through cleaning and disinfection.

Chemotherapy

The use of chemicals or drugs to treat disease

Antimicrobial Drugs

Target infectious microorganism killing or inhibiting their growth

Bacteriostatic Drugs

Cause a reversible inhibition of growth, with bacterial growth restarting after elimination of the drug

Bactericidal Drugs

Kill their target bacteria.

Narrow Spectrum Antimicrobial drugs

Effective against specific subsets/Groups of bacterial pathogens.

-Does not attack the microbiota

Broad Spectrum Antimicrobial drugs

Effective against a wide variety of bacterial pathogens

• May lead to Superinfection (infection on top of another)

Dosage Considerations

Amount of meds within a certain time period to ensure optimum therapeutic leveland minimize toxicity or resistance.

Oral Administration

Absorbed from the gastrointestinal tract into the bloodstream

IV (Parenteral)

Intravenous

-Plasma levels substantially higher 

IM (Parenteral)

Intramuscular

-

Drug Interactions

Synergistic

2 drugs administered together benefitting patient

Antagonistic

When 1 drug inhibits the other or alters its effect negatively

Vertical ransmission

Mother to Child

Horizontal Gene Transfer

Within a generation, Genetic Transfer of resistant genes

Jumping genes

Segments of DNA that can move within a genome, causing mutations or altering gene expression.

Drug Modification or Inactivation

Betalactam rings are broken down by Betalactamases (important enzymatic??)

Prevention of Cellular Uptake or Efflux

-Changes to porin (pores in microbial membranes) preventing drugs from getting in 

-Efflux Pumps- send stuff outward specific to antibiotics (reduces impact of antibiotic

Target Modification

Comes down to specificity

Target Overproduction or Enzymatic Bypass

PBP inhibits betalactamase drugs from binding 

-Low affinity PBP is a variant that has been modified

Multidrug-Resistant Microbes (MDRs) “Super Bugs”

Cross resistance=Single mechanism giving resistant to multiple antimicrobial drugs 

• ESKAPE lol know Staph Aureus

Examples

• MRSA- Methicillin resistance. Designed to resist inactivation by betalactamases. Widespread opportunistic of skin and wounds. Wash hands to reduce spread of MRSA

  • HA-MRSA- hospital acquired

  • CA-MRSA- Community acquired

• VRE, Vancomycin Resistance.

• VRSA-Vancomycin Resistance

• CRE, Carbapenem resistance. 

  • Pan resistance exists = Resistance to all known drug classes

• DR-TB, One drug resistance. 

• MDR-TB, Multidrug resistance. Caused by Incorrect microbial use 

• XDR-TB Extensive drug resistance Caused by Incorrect microbial use

• ESBLs

Extended Spectrum Betalactamase producing gram negative pathogens 

Break down everything but not carbopenams

Epidemiology

The study of Location & Timing of outbreaks (for prevention)

• About populations not individuals 

Etiology

Cause of a disease 

• Know Correlation is not causation* & causation is hard to prove. 

• Etiology agent - causative agent = what caused the disease

Transmission

How the disease-causing agent is spread from one host to another

Defining Populations in Epidemiology

-Geographic Region

-Behavior (EX IV drug use, Pets ownership)

-Size is also important

Mortality

Death rate

Morbidity

State of being diseased

• Total Morbidity = An absolute Number

• Morbidity Rate = “per 100” or a percentage

Incidence

The number of new cases of a disease

• often expressed per 1,000 etc.

• Goes up & up

Prevalence

Total with illness in a given population at a point in time.

• Fluctuates as people die and no longer have symptoms

Patterns of Incidence

Sporadic Disease

Occurs Occasionally 

• Tetnus,rabies, plague

Endemic Disease

Constant within a region

Epidemic Disease

High incidence within short time within a region 

• Antigenic shift and drift organisms change ?

Pandemic Disease

Epidemic on a worldwide scale 

Florence Nightingale (Role in Infectious Disease)

-Proved Soldiers dying from wound infections not just the wound leading to medical reforms

-Pioneered data use in epidemiology

Joseph Lister

-Greatly reduced post surgical infections

-Used phenol as disinfectant

Types of Spread

Common Source Spread (JOHN SNOW) all cases trace back to a single course

• Point Source Spread Short Exposure 

• Continuous Common Source Spread ongoing exposure 

• Intermittent Common Source Spread cause that comes and goes 

Observational Studies

Look but don’t touch

Descriptive Epidemiology

Who what Where and when 

Analytical Epidemiology

Tests hypotheses (why, how) , Comparison groups, more complex

Retrospective Studies

Past data to find links

Prospective Studies

Track People Overtime

Experimental Studies

Done in labs or clinical settings 

Researchers assign tx groups

Sometimes very unethical 

Prove causation 

Reducing bias in Experimental Studies

-Randomized - 

-Double Blind -

-Placebo/Controls - 

Reservoirs

Where a pathogen lives

Non-Living

Soil & WATER

Living

Human & Animals

Carriers = Infected but no present symptoms

• Passive Carriers

• Active Carriers

• Asymptomatic Carriers

Direct Contact Transmission

Vertical Direct Contact Transmission

Horizontal Direct Contact Transmission

Droplet Transmission

Indirect Contact Transmission

Transmission through fomites (Contaminated objects, surfaces, or vectors) without direct physical contact.

Vehicle Transmission

Any substance that carries pathogens to humans or animals.

• Food

• Water

• Air

Vector Transmission

Insects or Animals, that carry the disease from one host to another.

Mechanical

On the body of the insect or animal

Biological

Inside the body of the insect or animal

• Spread by bites

Quarantining

Stops the spread of a disease

• Can be enforced by law or Self

• PPE used in clinical setting to protect healthcare workers and patients from infection.

Healthcare-Associated (Nosocomial) Infections

Infections acquired by patients while receiving treatment for other conditions within a healthcare setting, such as hospitals or clinics.

• Higher risk if you have a weak immune system

• Prevention includes infection control

World Health Organization (WHO)

A specialized agency of the United Nations responsible for international public health, coordinating responses to health emergencies.

• Global

• No legal control

Centers for Disease Control and Prevention (CDC)

Public health agency in the United States that focuses on disease control and prevention, providing guidance on public health practices and responding to health crises.

• Part of HHS

Disease

When body structure/function is damaged

Infection

Germs grow in body. May cause disease

Signs

Objective & measurable 

Symptoms

Subjective, Reported by patient but not able to be verified

Syndrome

Signs & Symptoms seen together that indicate a particular health condition or disorder.

Asymptomatic

No signs or symptoms of a disease or condition.

Infectious Disease

A disease caused by pathogenic microorganisms, such as bacteria, viruses, parasites, or fungi.

Communicable

Spread between People

NonCommunicable

Not Spread between People

Contagious

Easily spreads between people

NonInfectious Disease

A medical condition that is not caused by infectious agents

• often chronic

• diabetes, cancer, or heart disease.

Transient, Acute,Chronic, & Latent Diseases

• Transient one instance (example:panic attack)

• Acute being short-term

• Chronic being long-lasting

• Latent representing periods of inactivity.

Latrogenic

Caused by medical procedures

Nosocomial

Acquired in the hospital setting

Zoonotic

Transferred from animals to humans

Inherited

Acquired through genetics

Congenital

Acquired at or before birth