Related Experiment Video
Updated: Nov 18, 2025
Isolation and Identification of Waterborne Antibiotic-Resistant Bacteria and Molecular Characterization of their Antibiotic Resistance Genes
Published on: March 3, 2023
Extended-spectrum beta-lactamase-producing enterobacterales carrying the mcr-1 gene in Lima, Peru
Katherine Yauri-Condor1, Milagros Zavaleta Apestegui1, Carlos Raúl Sevilla-Andrade1,2
1Centro de Investigaciones Tecnológicas, Biomédicas y Medioambientales - CITBM, Universidad Nacional Mayor de San Marcos, Lima, Perú.
Abstract:
We analyzed the presence of the mcr-1 gene in 165 extended-spectrum beta-lactamase-producing enterobacterales (ESBL-PE) obtained during 2017, from blood (40), urine (57), lower respiratory secretions (12) and rectal swabs (56) of patients hospitalized in the Instituto Nacional de Enfermedades Neoplásicas (Peru). Antimicrobial identification and susceptibility were determined by the Phoenix M50 automated system; colistin resistance by Colistin Agar-Spot (CAS); mrc-1 detection by colistin pre-diffusion and inhibition with EDTA test (CPD-E) and by polymerase chain reaction (PCR). We found that from the 165 ESBL-PE, 25 were positive for mcr-1 by the CPD-E method and confirmed by PCR. Colistin resistance was found in 20/165 by using the CAS method. Additionally, they showed resistance to fluoroquinolones and gentamicin, while remaining sensitive to amikacin; two isolates presented metallo-carbapenemases. Obtaining data on resistance to last-line antimicrobials (colistin) is crucial to establish measures for its control.
Insights
The mcr-1 gene, conferring colistin resistance, was detected in 25 of 165 extended-spectrum beta-lactamase-producing Enterobacterales. This finding highlights the need for surveillance of last-line antibiotic resistance in hospital settings.
Area of Science:
- Microbiology
- Infectious Diseases
- Antimicrobial Resistance
Background:
- Extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-PE) are a significant cause of hospital-acquired infections.
- The emergence of colistin resistance, mediated by the mcr-1 gene, poses a critical threat to public health.
- Surveillance of antimicrobial resistance patterns is essential for effective infection control.
Purpose of the Study:
- To investigate the prevalence of the mcr-1 gene in ESBL-PE isolates from a Peruvian hospital.
- To determine the antimicrobial resistance profiles of these isolates, focusing on colistin resistance.
- To provide data for establishing control measures against last-line antibiotic resistance.
Main Methods:
- Analysis of 165 ESBL-PE isolates from blood, urine, respiratory secretions, and rectal swabs collected in 2017.
- Antimicrobial susceptibility testing using the Phoenix M50 automated system.
- Detection of mcr-1 gene using colistin pre-diffusion and inhibition with EDTA test (CPD-E) and polymerase chain reaction (PCR); colistin resistance assessed by Colistin Agar-Spot (CAS).
Main Results:
- The mcr-1 gene was detected in 25 out of 165 (15.15%) ESBL-PE isolates, confirmed by both CPD-E and PCR.
- Colistin resistance was observed in 20 out of 165 (12.12%) isolates using the CAS method.
- Resistant isolates also showed resistance to fluoroquinolones and gentamicin, with two isolates harboring metallo-carbapenemases, while remaining sensitive to amikacin.
Conclusions:
- The presence of the mcr-1 gene in ESBL-PE highlights a significant challenge in combating multidrug-resistant infections.
- Understanding colistin resistance prevalence is crucial for implementing targeted interventions and infection control strategies.
- Continued monitoring of resistance to last-line antibiotics like colistin is vital for global antimicrobial stewardship efforts.
Related Concept Videos
01:30Development of Antibiotic Resistance
01:23Stringent Response in E. coli