Abstract
BackgroundA plasmid-mediated mechanism of bacterial resistance to polymyxin is a serious threat to public health worldwide. The present study aimed to determine the occurrence of plasmid-mediated colistin resistance genes and to conduct the molecular characterization of mcr-positive Escherichia coli strains isolated from Polish poultry.MethodsIn this study, 318 E. coli strains were characterized by the prevalence of mcr1–mcr5 genes, antimicrobial susceptibility testing by minimal inhibitory concentration method, the presence of antimicrobial resistance genes was screened by PCR, and the biofilm formation ability was tested using the crystal violet staining method. Genetic relatedness of mcr-1-positive E. coli strains was evaluated by multilocus sequence typing method.ResultsAmong the 318 E. coli isolates, 17 (5.35%) harbored the mcr-1 gene. High antimicrobial resistance rates were observed for ampicillin (100%), tetracycline (88.24%), and chloramphenicol (82.35%). All mcr-1-positive E. coli strains were multidrug-resistant, and as many as 88.24% of the isolates contained the blaTEM gene, tetracycline (tetA and tetB), and sulfonamide (sul1, sul2, and sul3) resistance genes. Additionally, 41.18% of multidrug-resistant, mcr-1-positive E. coli isolates were moderate biofilm producers, while the rest of the strains showed weak biofilm production. Nine different sequence types were identified, and the dominant ST was ST93 (29.41%), followed by ST117 (17.65%), ST156 (11.76%), ST 8979 (11.76%), ST744 (5.88%), and ST10 (5.88%). Moreover, the new ST was identified in this study.ConclusionsOur results showed a low occurrence of mcr-1-positive E. coli strains isolated from Polish poultry; however, all the isolated strains were resistant to multiple antimicrobial agents and were able to form biofilms at low or medium level.
Highlights
Antimicrobial resistance (AMR) has emerged as one of the most important global threats to human health in the last few decades
Among all the tested E. coli strains (n = 318), 17 isolates (5.35%) were mcr-1 positive, whose presence was confirmed by the 100% of nucleotide identity of the amplicons when they were sequenced
Antimicrobial susceptibility of the E. coli strains carrying the detected mcr-1 gene is shown in Table 2 Occurrence of resistance genes to antimicrobial agents, resistance profiles, biofilm formation, and sequence types (STs) in mcr-1-positive Escherichia coli strains (n = 17)[Display Image Removed]White square — lack of resistance gene; black square — presence of resistance gene.GEN, gentamicin; AMP, ampicillin; CTX, cefotaxime; CAZ, ceftazidime; MEM, meropenem; NAL, nalidixic acid; CIP, ciprofloxacin; CHL, chloramphenicol, AZM, azithromycin; CST, colistin; TET, tetracycline; TGC, tigecycline; SMX, sulfamethoxazole; TMP, trimethoprim.Biofilm formation: + + + — strong biofilm former, + + — moderate biofilm former, + — weak biofilm former
Summary
Antimicrobial resistance (AMR) has emerged as one of the most important global threats to human health in the last few decades. Brazilian Journal of Microbiology (2021) 52:1597–1609 avian colibacillosis, gastroenteritis, and diarrhea to reduce high incidence and mortalities Such overuse and/or misuse of antibiotics contribute to the development and spread of AMR among poultry strains and flocks, leading to the emergence of multidrug-resistant (MDR) pathogens [5]. The present study aimed to determine the occurrence of plasmid-mediated colistin resistance genes and to conduct the molecular characterization of mcr-positive Escherichia coli strains isolated from Polish poultry. 41.18% of multidrug-resistant, mcr-1-positive E. coli isolates were moderate biofilm producers, while the rest of the strains showed weak biofilm production. Conclusions Our results showed a low occurrence of mcr-1-positive E. coli strains isolated from Polish poultry; all the isolated strains were resistant to multiple antimicrobial agents and were able to form biofilms at low or medium level
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
