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Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Detection and characterization of aparmycin-resistant Escherichia coli from humans in Korea
Suk-Kyung Lim1, Hyang-Mi Nam, Aeran Kim
1National Veterinary Research and Quarantine Service, Anyang, Republic of Korea. imsk0049@korea.kr
Abstract:
To investigate apramycin resistance in humans in Korea, a total of 138 human Escherichia coli strains confirmed as gentamicin-resistant were collected from Korean Culture Collection Antimicrobial-Resistant Microbes. Apramycin resistance (minimum inhibitory concentrations ≥1,024 μg/ml) was observed in 16 (11.6%) of the 138 gentamicin-resistant E. coli (GREC) strains. Among the seven different kinds of aminoglycoside resistance genes tested, only four kinds were detected in the apramycin-resistant GREC strains: aac (3)-II, aac (3)-III, aac (3)-IV, and armA. The aac (3)-IV gene was found in all apramycin-resistant GREC strains, whereas aac(3)-II, aac(3)-III, and armA genes were detected in 8 (50.0%), 6 (37.5%), and 1 (6.3%) GREC strains resistant to apramycin, respectively. Of 16 apramycin-resistant GREC strains, transfer of apramycin resistance was observed in seven (43.8%), and co-transfer of resistance to other antimicrobials along with apramycin resistance was also found in four strains (25.0%) by broth mating. The results of this study suggest that more prudential use of apramycin in animals is needed.
Insights
Apramycin resistance is emerging in human Escherichia coli strains in Korea, with 11.6% of gentamicin-resistant strains showing resistance. The aac(3)-IV gene was most common, and resistance transfer was observed, highlighting the need for prudent apramycin use in animals.
Area of Science:
- Microbiology
- Antimicrobial Resistance
- Genetics
Background:
- Antimicrobial resistance in bacteria poses a significant global health threat.
- Escherichia coli is a common human pathogen, and its resistance to antibiotics is a growing concern.
- Apramycin is an aminoglycoside antibiotic used primarily in veterinary medicine.
Purpose of the Study:
- To investigate the prevalence and genetic basis of apramycin resistance in human Escherichia coli strains in Korea.
- To determine the mechanisms of apramycin resistance, including the presence of specific aminoglycoside resistance genes.
- To assess the potential for transfer of apramycin resistance among bacterial strains.
Main Methods:
- Collection and identification of 138 gentamicin-resistant Escherichia coli strains from the Korean Culture Collection Antimicrobial-Resistant Microbes.
- Determination of apramycin resistance using minimum inhibitory concentration (MIC) testing.
- Detection of aminoglycoside resistance genes (aac(3)-II, aac(3)-III, aac(3)-IV, and armA) using molecular methods.
- Assessment of apramycin resistance transfer via broth mating experiments.
Main Results:
- Apramycin resistance was detected in 16 (11.6%) of the 138 gentamicin-resistant E. coli strains.
- The aac(3)-IV gene was present in all apramycin-resistant strains.
- Other detected genes included aac(3)-II (50.0%), aac(3)-III (37.5%), and armA (6.3%).
- Apramycin resistance was transferable in 43.8% of resistant strains, with co-transfer of other resistances observed in 25.0%.
Conclusions:
- Apramycin resistance is present in human Escherichia coli strains in Korea, often associated with gentamicin resistance.
- The aac(3)-IV gene is a key determinant of apramycin resistance in these strains.
- The potential for horizontal gene transfer of apramycin resistance necessitates a more prudent use of this antibiotic in animal agriculture to prevent further dissemination.
