Transmission of Carbapenem Resistance Between Human and Animal NDM-Positive Escherichia coli Strains

Although carbapenem use is prohibited in animals in China,carbapenem-resistant Escherichia coli(CREC),especially New Delhi metallo-β-lactamase(NDM)-producing strains,are widely prevalent in foodproducing animals.At present,the impact of livestock-associated CREC strains on human populations at the national level is unknown.Here,we conduct a retrospective cross-sectional study to investigate the prevalence of CREC from clinical settings across 22 Chinese provinces or municipalities and analyze anthropogenic factors associated with their presence.We also ascertain the blaNDMand blaKPCabundance among pig and chicken farms and present a detailed genomic framework for CREC of animal and human origin.Overall,631/29799(2.1%)clinical Escherichia coli(E.coli)isolates were identified as CREC.Multivariable analysis revealed that being male,an age below 1,an age between 13 and 18,provinces with greater chicken production,and provinces with higher pig production were associated with higher odds of CREC infection.In general,73.8%(n=45/61)of pig farms and 62.2%(n=28/45)of chicken farms had a blaNDMabundance of 1×10^(-5)to 1×10^(-3)and 1×10^(-3)to 1×10^(-2),respectively.Among all the Chinese NDM-positive E.coli(n=463)available at the National Center for Biotechnology Information(NCBI),the genomic analysis revealed that blaNDM-5and Inc X3 were the predominant carbapenemase gene-plasmid combination,while a highly homogeneous relationship between NDM-positive isolates from humans and animals was demonstrated at the plasmid and core genome levels.All the findings suggest frequent CREC transmission between humans and animals,indicating that further discussions on the use of antibiotics in animals and humans are needed,both in China and across the globe.

Expert Consensus on Polymyxin Antimicrobial Susceptibility Testing and Clinical Interpretation

The polymyxins are important antimicrobial agents against antibiotic-resistant gram-negative bacilli.In 2020,the Clinical and Laboratory Standards Institute modified the clinical breakpoints for polymyxin susceptibility test by eliminating the"susceptible"interpretive category,only reporting intermediate(≤2 mg/L)and resistant(≥4 mg/L).However,the European Committee on Antimicrobial Susceptibility Testing recommended the use of clinical breakpoints of W2 mg/L as susceptible and>2 mg/L as resistant.The first-line laboratorians and clinicians in China have been perplexed by the inconsistence of international polymyxin clinical breakpoints and discouraged by the difficulty of conducting polymyxin susceptibility testing.Therefore,it is urgently needed to make it clear for the laboratorians in China to know how to accurately carry out polymyxin susceptibility testing and standardize the interpretation of susceptibility testing results.To this end,the experts from relevant fields were convened to formulate this consensus statement on the testing and clinical interpretation of polymyxin susceptibility.Relevant recommendations are proposed accordingly for laboratorians and clinicians to streamline their daily work.

Chinese consensus guidelines for therapeutic drug monitoring of polymyxin B,endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society

Polymyxin B,which is a last-line antibiotic for extensively drug-resistant Gram-negative bacterial infections,became available in China in Dec.2017.As dose adjustments are based solely on clinical experience of risk toxicity,treatment failure,and emergence of resistance,there is an urgent clinical need to perform therapeutic drug monitoring(TDM)to optimize the use of polymyxin B.It is thus necessary to standardize operating procedures to ensure the accuracy of TDM and provide evidence for their rational use.We report a consensus on TDM guidelines for polymyxin B,as endorsed by the Infection and Chemotherapy Committee of the Shanghai Medical Association and the Therapeutic Drug Monitoring Committee of the Chinese Pharmacological Society.The consensus panel was composed of clinicians,pharmacists,and microbiologists from different provinces in China and Australia who made recommendations regarding target concentrations,sample collection,reporting,and explanation of TDM results.The guidelines provide the first-ever consensus on conducting TDM of polymyxin B,and are intended to guide optimal clinical use.

Multicenter Antimicrobial Resistance Surveillance of Clinical Isolates from Major Hospitals—China,2022

What is already known about this topic?Bacterial resistance surveillance is crucial for monitoring and understanding the trends and spread of drug-resistant bacteria.What is added by this report?The number of strains collected in 2022 increased compared to 2021.The top five bacteria,including Escherichia coli,Klebsiella pneumoniae,Staphylococcus aureus,Pseudomonas aeruginosa,and Acinetobacter baumannii,remained largely unchanged.The detection rate of methicillin-resistant strains continued to decrease.Among clinical Enterobacterales isolates,the resistance rate to carbapenems was generally below 13%,except for Klebsiella spp.,which had a resistance range of 20.4%to 21.9%.Most clinical Enterobacterales isolates were highly susceptible to tigecycline,colistin,and polymyxin B,with resistance rates ranging from 0.1%to 12.6%.The detection rate of meropenem-resistant P.aeruginosa and meropenemresistant Acinetobacter baumannii showed a decreasing trend for the fourth consecutive year.What are the implications for public health practice?Multidrug-resistant bacteria remain a significant public health challenge in clinical antimicrobial treatment.To effectively address bacterial resistance,it is essential to enhance both bacterial resistance surveillance and the prudent use of antimicrobial agents.

Current status and trends of antimicrobial resistance among clinical isolates in China:a retrospective study of CHINET from 2018 to 2022

Antimicrobial resistance(AMR)is a pressing issue in China,with antibiotic therapy becoming less effective against bacterial infections.To address this challenge,the China Antimicrobial Surveillance Network(CHINET)was established in 2005 to monitor antimicrobial resistance in the country.This study analyzed the CHINET data from teaching hospi-tals and evaluated the trends of AMR in China from 2018 to 2022.A range of 163,636 to 301,917 isolates was obtained per year,with the majority being Gram-negative bacilli(69.0%to 71.8%).The proportion of important multidrug-resistant pathogens remained stable over the years.While the analysis showed diverse AMR profiles for different bac-terial species.Over the five years,generally decreased resistance rates were observed from the majority of the tested species.For example,resistance to ceftriaxone decreased in Escherichia coli and Klebsiella pneumoniae,while resistance to imipenem and meropenem decreased in Pseudomonas aeruginosa.Moreover,resistance to methicillin,gentamicin,fosfomycin,and clindamycin also decreased in clinical Staphylococcus aureus isolates.On the other hand,resistance levels of Acinetobacter baumannii remained stable.Our study provides a comprehensive overview of the AMR profiles of common bacterial species in China and highlights the ongoing efforts to address this challenge.

China antimicrobial resistance surveillance network for pets(CARPet),2018 to 2021

China Antimicrobial Resistance Surveillance Network for Pets(CARPet)was established in 2021 to monitor the resist-ance profiles of clinical bacterial pathogens from companion animals.From 2018 to 2021,we recovered and tested 4,541 isolates from dogs and cats across 25 Chinese provinces,with Escherichia coli(18.5%)and Staphylococcus pseudintermedius(17.8%)being the most predominant bacterial species.The Enterobacterales were highly susceptible to tigecycline,meropenem,colistin,and amikacin(70.3%-100.0%),but showed moderate resistance to ampicillin,ceftriaxone,doxycycline,florfenicol,levofloxacin,enrofloxacin,and trimethoprim-sulfamethoxazole(29.3%-56.7%).About 66.3%of Acinetobacter spp.were resistant to florfenicol,with relatively low resistance to another 11 antibiot-ics(1.2%-23.3%).The Pseudomonas spp.showed high susceptibility to colistin(91.7%)and meropenem(88.3%).The coagulase-positive Staphylococcus spp.showed higher resistance rates to most antimicrobial agents than coagulase-negative Staphylococcus isolates.However,over 90.0%of Staphylococcus spp.were susceptible to linezolid,dapto-mycin and rifampin,and no vancomycin-resistant isolates were detected.E.faecium isolates demonstrated higher resistance rates to most antimicrobial agents than E.faecalis isolates.Streptococcus spp.isolates showed low resistance to most antimicrobial agents except for doxycycline(78.2%)and azithromycin(68.8%).Overall,the tested clinical isolates showed high rates of resistance to commonly used antimicrobial agents in companion animals.Therefore,it is crucial to strengthen the monitoring of bacterial resistance in pets.By timely and effectively collecting,analyzing,and reporting antimicrobial resistance dynamics in pets,the CARPet network will become a powerful platform to provide scientific guidance for both pet medical care and public health.