Antimicrobial resistance is the ability of a microorganism (e.g., a bacterium, a virus, or a parasite) to resist the action of an antimicrobial agent resulting in a reduction or elimination of effectiveness of the antimicrobial agent to cure or prevent infection due to this microorganism.

Some bacteria are naturally resistant to certain antibiotics (intrinsic or inherent resistance). A more worrying problem is when some bacteria that are normally susceptible to antibiotics become resistant as a result of adaptation through genetic change (acquired resistance).

Multidrug resistance corresponds to resistance of a microorganism to multiple antimicrobials. The challenge with multidrug-resistant microorganisms lies in the limited number of remaining options (if any) for therapy of patients infected with these microorganisms.

Antimicrobial resistance is a worldwide problem. Although some countries are reporting a decrease in prevalence of some resistant bacteria, antimicrobial resistance still is high or increasing in many countries, in particular for common bacteria such as Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Additionally, cases of infections due to bacteria totally or almost totally resistant to antibiotics are currently emerging in the EU. Examples of such bacteria are carbapenemase (KPC)-producing Enterobacteriaceae (often Klebsiella pneumoniae), and multidrug-resistant Acinetobacter.

• Antibiotic-resistant bacteria cause longer illness or even death
• Antibiotic-resistant bacteria cause infections that may require more care, and often longer hospital stays
• Antibiotic-resistant bacteria require alternative and more expensive antibiotics, which also may have more severe side effects
• Antibiotic-resistant bacteria may require intravenous antibiotic therapy in hospital instead of oral antibiotics that could be taken at home
• Infection control precautions are essential to prevent spread of antibiotic resistant bacteria from infected patients or carriers to other individuals
• Even when antibiotics are used appropriately, antibiotic resistance sometimes develops as a natural adaptive reaction of bacteria
• There are very few antimicrobial therapies in the research and development pipeline that would potentially be effective against resistant bacteria

References

1. ECDC information on Antimicrobial Resistance
2. Antibiotic Guardian Campaign
3. UK 5 year Antimicrobial Resistance Strategy 2013-2018
4. ECDC database for Antimicrobial Resistance surveillance

Detection of Resistance Genes

Oxford Biosystems is able to supply a selection of products for the detection and identification of antimicrobial resistance genes in clinical samples.

The AID Diagnostika Line Probe Assays are based on the reverse hybridisation of DNA and produce reliable and reproducible results. The tests are suitable for automated systems and the results are evaluated and documented with AID scanner and software.

Kits are available for:

• MRSA

Differentiation of Staphylococcus aureus and coagulase negative staphylococci
Detection of mecA and mecC
Detection of the most frequent resistance genes of staphylococci

• ESBL

Detection of the most important mutations in TEM and SHV
Detection of CTX-M and KPC (Klebsiella pneumoniae carbapenamase)
Validated for use with bacterial cultures and clinical samples

• TB Resistance

Detection of Mycobacteria and Mycobacterium tuberculosis complex
Detection of Isoniazid and Rifampicin resistance genes
Detection of Kanamycin, Amikacin and Capreomycin resistance genes
Detection of Fluoroquinolone and Ethambutol resistance genes
Validated for use with bacterial cultures and clinical samples

• Carbapenamases

16S pan bacterial control included
Detection of 13 different carbapenamase resistance genes
Validated for use with bronchoelar lavage, sputum, wound swabs, bacterial cultures