Evaluation of Commercial Products for Colistin and Polymyxin B Susceptibility Testing for mcr-Positive and Negative Escherichia coli and Klebsiella pneumoniae in China

Abstract

To evaluate the performance of five widespread commercial products for colistin and polymyxin B susceptibility testing in China for mcr-positive and -negative Escherichia coli and Klebsiella pneumoniae. Methods: A total of 132 E. coli and 83 K. pneumoniae strains (including 68 mcr-1-positive E. coli and 28 mcr-8-positive K. pneumoniae) were collected. We analysed the performance of colistin susceptibility (with Vitek 2 and Phoenix M50) and the performance of polymyxin B susceptibility (with DL-96II, MA120, and a Polymyxin B Susceptibility Test strip; POL E-strip). Broth microdilution was used as the gold standard. Categorical agreement (CA), essential agreement (EA), major error (ME), and very major error (VME) were calculated for comparisons. Results: For E. coli, the total CA, EA, ME, and VME to colistin were as follows: Vitek 2, 98.

Challenges in the Detection of Polymyxin Resistance: From Today to the Future

“…VITEK 2 ® COMPACT (BioMérieux, St. Louis, MO, USA) and Phoenix™ M50 (Becton Dickson Diagnostics, Franklin Lakes, NJ, USA) are the most widely used microbial identification and drug susceptibility analysis systems in the world [ 24 , 25 ]. The performance of these systems was tested against polymyxins in 132 strains of E. coli and 83 strains of K. pneumoniae , including strains positive for the mcr-1 and mcr-8 genes.…”

“…However, the systems exhibited unacceptable rates of CAs, EAs, and false-susceptible results, especially with K. pneumoniae isolates. Furthermore, the systems did not demonstrate good performance for detecting strains with the mcr-8 gene [ 24 ].…”

Prevalence of Antimicrobial Resistance in Escherichia coli and Salmonella Species Isolates from Chickens in Live Bird Markets and Boot Swabs from Layer Farms in Timor-Leste

“…For colistin, a warning on the accuracy of several commercial systems for MIC results was previously issued by EUCAST, although it did not specifically evaluate the BD Phoenix M50 [68,69]. Recent studies indicate that the BD Phoenix M50 can produce accurate MIC results for colistin [70][71][72], and this has led to its inclusion in this study. The resistance to colistin in E. coli from chickens (6.6%) in this study was higher than that reported in many European countries where resistance is usually less than 1% [73][74][75], but resistance was lower than that reported in other parts of Asia [76].…”

Chromogenic Agar Assisted Screening of Pathogenic Bacteria from Butcher shops Wastewater Effluent and their Antibiotic Susceptibility Profiling

“…By applying the Vitek 2 system, clinicians can recognize various types of bacteria, both gram-positive and gram-negative, allowing them to provide effective and targeted therapies for infections. Its effectiveness and speed make it a vital instrument in diagnosing and treating infectious ailments, which is why it is increasingly used in clinical settings globally [15,16]. Overall, the isolation and identification of pathogenic bacteria in wastewater effluent from butcher shops, and their antibiotic susceptibility profiling, are crucial for preventing the spread of antibiotic resistance and ensuring public health.…”