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Skip to 0 minutes and 4 seconds Good day, everybody. We can broadly define bacterial resistance from the practical point of view in two categories. First, microbiological resistance, which can be defined as the enhanced ability of the microorganism to counteract the lethal or static effects of the antimicrobials. This is achieved through adaptation of specific biological mechanisms that may render them either absolutely resistant or even less susceptible to antimicrobials when compared to other members of the same species. The other type is clinical resistance, which is addressed by when the bacteria is exposed to properly-selected antibiotic or combinations of antibiotic, administered in adequate dose for the necessary duration with unmet clinical outcomes, which may be due to unexpected alteration in the pharmacokinetics or pharmacodynamics parameters in this case.

Skip to 1 minute and 13 seconds Our main target for this lecture is not only to identify or understand the bacterial resistance, but only how to use these findings and data into our clinical practise. We have to suppress these data in a way that can be used by the practitioners in their daily clinical practise in dealing with different infections. After we understand these modalities and identify the inducing factors and possibilities of transmission between bacteria or species, this information should be delivered into the practise through surveillance studies or comprehensive antibiograms that may serve as a guidance for the treatment of infectious disease.

Skip to 2 minutes and 8 seconds Furthermore, these data is used by research and development of antimicrobials to provide alternative or novel medications for treatment of these resistance infections caused by resistant phenotypes. In the meantime, we struggle to defeat bacterial infections. The bacteria itself become more clever to counteract our attacks. Develop many manoeuvres of resistance. This developed bacterial resistance appears through a diversity of mechanisms. Actually, it starts at the bacterial cell wall through modified permeability through down-regulation of the cell porins, which serves as the passage for the antibiotics. Minimise the availability of antibiotics intracellularly through over-expression of the efflux pumps, which is the excretion tool of the bacterial cell. And the impairment of antimicrobial fitting to its target through target alteration.

Skip to 3 minutes and 28 seconds They can also hide from the action of antibiotics and the harsh environment through the biofilm construction, which you can call the city of microbes. Enzymatic deactivation of the antimicrobials remain the most common and effective resistance tool of the bacteria. Finally, this table summarises the mechanism of resistance corresponding to each antibiotic group. The resistance may be due to a single mechanism or multiple mechanisms. But the deactivating enzymes predominates over the other resistance mechanisms, followed by altered penicillin binding proteins, and the efflux pump over-expression.

Microbiology of antimicrobial resistance

In this video, Dr Diaa Alrhamany provides a quick overview of the types of resistance, the mechanisms of resistance and briefly mentions the importance of surveillance which will be discussed further in week two of the course.

We can broadly define bacterial resistance in two categories:

  • Microbiological resistance
    • This is achieved through the adaptation of specific biological mechanisms that may render them less susceptible or even absolutely resistant to antimicrobials.
  • Clinical resistance
    • This is when the bacteria is exposed to properly-selected antibiotics, administered in adequate dose for the necessary duration with unmet clinical outcomes.

Types of resistance:

  • Down-regulation of the cell porins, which serves as the entrance passage for the antibiotics

  • Minimising the availability of antibiotics intracellularly through over-expression of the efflux pumps

  • Deactivating enzymes by altering the target

  • They can also hide from the action of antibiotics through the biofilm construction

Resistance may be due to a single mechanism or multiple mechanisms. Enzymatic deactivation of the antimicrobials remains the most common and effective resistance tool of the bacteria.

Data must be expressed in a way that can be used by the practitioners in their daily clinical practice through surveillance studies such as antibiograms. This will be discussed further in step 2.5. Furthermore, this data can then be used for the research and development of antimicrobials to provide alternative or novel medications for the treatment of these resistant infections.

The next step will discuss what AMS is and why it is important.

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This video is from the free online course:

Antimicrobial Stewardship for the Gulf, Middle East and North Africa

BSAC