Related Experiment Video
Updated: Aug 9, 2026
12:03
Antimicrobial Synergy Testing by the Inkjet Printer-assisted Automated Checkerboard Array and the Manual Time-kill Method
Published on: April 18, 2019
Amikacin-resistant gram-negative bacilli: correlation of occurrence with amikacin use
The Journal of Infectious Diseases
|February 1, 1985
Summary
Amikacin resistance in gram-negative bacilli rose significantly, coinciding with increased amikacin usage. Enzymatic modification, specifically 6'-N-acetyltransferase, was identified as a primary mechanism for this growing resistance.
Area of Science:
- Microbiology
- Infectious Diseases
- Pharmacology
Background:
- Amikacin is a critical aminoglycoside antibiotic used against serious gram-negative bacterial infections.
- Rising antibiotic resistance poses a significant threat to public health, necessitating surveillance and understanding of resistance mechanisms.
Purpose of the Study:
- To investigate the trend of amikacin resistance in gram-negative bacilli at a specific medical center.
- To identify the common bacterial species exhibiting amikacin resistance.
- To determine the prevalence and type of amikacin resistance mechanisms.
Main Methods:
- Retrospective analysis of bacterial isolates and antibiotic susceptibility data.
- Monitoring amikacin usage patterns over an 18-month period.
- Biochemical detection of the amikacin-modifying enzyme 6 N-acetyltransferase in resistant isolates.
Main Results:
- Amikacin resistance increased from 2.0% to over 7% between January 1980 and July 1981.
- This rise correlated with a threefold increase in amikacin utilization.
- Klebsiella, Serratia, and Pseudomonas species were the most frequent amikacin-resistant (AKR) isolates.
- The 6 N-acetyltransferase enzyme was found in 67.5% of tested AKR isolates.
Conclusions:
- Amikacin resistance in this hospital setting is largely mediated by enzymatic modification.
- Increased amikacin use appears to be a driving factor for the observed rise in resistance.
- Targeted surveillance and antimicrobial stewardship are crucial to mitigate resistance development.
More Related Videos
Related Concept Videos
01:27Combined Effects of Drugs: Synergism
Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
Such synergistic combinations...
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...
01:30Development of Antibiotic Resistance
Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
01:25Mechanism of Antibiotic Resistance in MRSA
Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and acquisition...
01:25Inhibitors of Bacterial Protein Synthesis
Aminoglycosides constitute a highly potent class of bactericidal antibiotics that exert their antimicrobial effects by targeting the bacterial ribosome, specifically disrupting protein synthesis. These polycationic molecules consist of amino-modified sugars linked via glycosidic bonds to an aminocyclitol core such as 2-deoxystreptamine or streptamine. Their strong positive charges facilitate tight binding to the negatively charged phosphate backbone of ribosomal RNA (rRNA), primarily at the 16S...
01:25Clinical Significance of Antibiotic Resistance
Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within the One...