[MICRO 20] LEC 17 - Antimicrobial Susceptibility and Resistance

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[MICRO 20] LEC 17 - Antimicrobial Susceptibility and Resistance

[MICRO 20] LEC 17 - Antimicrobial Susceptibility and Resistance

[MICRO 20] LEC 17 - Antimicrobial Susceptibility and Resistance

Superbugs

These could eventually kill more people than cancer. If left unchecked, it can result in 10 million deaths each year by 2050 more than the number of people killed by cancer

Increasing global distribution of pathogens resistant to antimicrobial drugs

One of the greatest threats to human health leading to health crises arising from infections that were once easy to treat

TRUE

TRUE or FALSE

Greater volume of antibiotics used = greater changes that antibiotic resistant population develop

1 Longer hospital stays 2 Higher medical cost 3 Increased mortality 4 No more available effective antibiotics

Enumerate the four (4) consequences of Antimicrobial resistance.

Dysbiosis

The imbalance or the maladaptation inside the body, or exposure to harmful bacteria or even an outgrowth or overgrowth of a single type of bacteria

Plasmid DNA

These are small circular fragments of extrachromosomal DNA that can exist in bacterial cells in addition to chromosomal DNA. These are also associated with virulence and antibiotic resistance.

Antibiotics

It is a type of antimicrobial substance active against BACTERIA. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections.

Salvarsan

It is an antibiotic for the treatment of syphilis

Paul Ehrlich

He developed Salvarsan.

Alexander Fleming

He developed penicillin.

Antimicrobial drugs

Generally, these are medicines that are used to prevent and treat infections in humans, animals, and plants.

FALSE

Correct statement:

Bactericidal

• Kills the bacteria and has an irreversible effect

Bacteriostatic

• Stops the growth of bacteria which are helpful when immune system is competent and has a reversible effect

TRUE or FALSE

Bacteriostatic

• Kills the bacteria and has an irreversible effect

Bactericidal

• Stops the growth of bacteria which are helpful when immune system is competent and has a reversible effect

TRUE

TRUE or FALSE

Bacteriostatic drugs should not be given to immunocompromised patients because this drug requires aid of the host defenses

1. cell wall

2. protein

3. nucleic acid synthesis

What are the three targets of antibiotics?

HAPPY DAPAT

YOU'RE DOING GREAT.

KAYA MO 'TO.

HAPPY OR SAD?

Antibiotics Can Protect the Queen's Men, Servants, and Guards

Mnemonics used for the different classes of antibiotics.

1. Inhibition or regulation of enzymes involved in cell wall biosynthesis

2. Nucleic acid metabolism repair

3. Protein synthesis

4. Disruption of the membrane structure

Four mechanisms of antibacterial action

Peptidoglycan

Bacterial cells are surrounded by a cell wall made of ___________, which consists of long sugar polymers

Transglycosidases

Peptidoglycan undergoes cross-linking of the glycan strands by the action of _____________.

FALSE

Correct statement:

Β-lactams and the glycopeptides inhibit cell wall synthesis

TRUE or FALSE

Β-lactams and the glycopeptides inhibit cell wall eliminaition.

Cytoplasmic

Protein biosynthesis is catalyzed by ribosomes and __________ factors.

50S

The bacterial 70S ribosome is composed of two ribonucleoprotein subunits, the 30S and ____ subunits

fluoroquinolones

These inhibit the enzyme bacterial DNA gyrase, which nicks the double-stranded DNA, introduces negative supercoils and then reseals the nicked ends.

TRUE

TRUE or FALSE

A combination of sulpha drugs and trimethoprim acting at distinct steps on the same biosynthetic pathway shows synergy and a reduced mutation rate for resistance

Antimicrobial resistance

It is the loss of effectivity of antimicrobial drugs to kill microorganisms and treat infection.

Antimicrobial resistance

It occurs through mutation in microorganisms or acquisition of genetic material from other bacteria which neutralize or escape the effect of the antimicrobials

TRUE

TRUE or FALSE

The innate ability of a bacterial species to resist activity of an antimicrobial agent through its inherent structural or functional characteristics which allow tolerance of a particular drug or antimicrobial class

Efflux pumps

this is used for the pumping out of the drugs or some modifications of target molecules like impermeability, modification or even inactivation.

Vertical gene transfer

Transfer of genetic information including any genetic mutations from the parent to its offsprings

Horizontal gene transfer

Movement of genetic material from a donor organism to a recipient organism that is not its offspring

Transformation

(MECHANISMS OF HORIZONTAL GENE TRANSFER)

• Uptake of short fragments of naked DNA by naturally transformable bacteria and incorporation of naked DNA

Transduction

(MECHANISMS OF HORIZONTAL GENE TRANSFER)

• Transfer of genes by bacteriophage

• Transfer of DNA material from one bacterium to another via the bacteriophages

Conjugation

(MECHANISMS OF HORIZONTAL GENE TRANSFER)

• Transfer of genetic material from a donor to a recipient strain of bacteria

• Involving the transfer of DNA via sexual pilus and requires cell to cell contact

• DNA fragments that contain resistance genes from resistant donors can make previously susceptible bacteria express resistance as coded by this newly acquired resistance genes

Restriction enzymes

(MECHANISMS OF HORIZONTAL GENE TRANSFER)

Enzymes that cut DNA at specific sequences

Extrinsic resistance mechanism

It happens when bacteria that acquire resistance genes from other bacteria which already have resistance for the harsh environmental conditions

Acquired resistance

It is said to occur when a particular microorganism obtains the ability to resist the activity of an antimicrobial agent to which it was previously susceptible.

1. Producing destructive enzymes to neutralize antibiotics by modifying antimicrobial targets by mutation so that drugs cannot recognize them

2. Removing antimicrobial agents by popping them out from the cell

3. Restricting access of the antibiotic from entering the cell by limiting or changing the size of the opening not fitted to that antibiotic into getting into or penetrating the cell wall

4. Creating bypasses that allow bacteria to function without the enzymes targeted by the antibiotics

Bacteria resist the effects of antibiotics either by:

Antimicrobial surveillance

According to Pfizer, it refers to efforts to monitor changes in populations of microbes to help understand evolving patterns of resistance to anti-infectives. It can be conducted on a global, regional, local country, or healthcare facility basis.

Penicillin

Antibacterial drug used against Streptococcus pneumoniae