Extraintestinal pathogenic Escherichia coli (ExPEC) O-serotype distribution and antibiotic resistance profiles among the aging population in China: A longitudinal, multi-center study.

Extraintestinal pathogenic Escherichia coli (ExPEC) is a leading cause of community-acquired bacteremia and sepsis, which contributes to the substantial burden of invasive E. coli disease (IED) in older adults. This study aimed to estimate the O-serotype distribution of blood and sterile site ExPEC among older adults in China and the characteristics of antimicrobial resistance, O-serotypes, and O genotypes.

Antimicrobial activity of lefamulin against pathogens most commonly causing community-acquired pneumonia: results from the China antimicrobial surveillance network in 2020-2022.

Objectives: Lefamulin is a novel pleuromutilin antibiotic used for the treatment of community-acquired pneumonia (CAP). This study aimed to evaluate the in vitro antimicrobial activity of lefamulin against clinical isolates obtained from China.

Methods: 1,052 non-duplicate isolates included the following isolates: Streptococcus pneumoniae (n = 529), Staphylococcus aureus (n = 306), Haemophilus influenzae (n = 121), Moraxella catarrhalis (n = 81), and Mycoplasma pneumoniae (n = 15), were collected from 70 hospitals participating in the China Antimicrobial Surveillance Network (CHINET) between October 1, 2020, and November 30, 2022.

Epidemiology and resistance mechanisms of tigecycline- and carbapenem-resistant in China: a multicentre genome-based study.

Objectives: To elucidate the molecular epidemiology of tigecycline and carbapenem-resistant isolates and mechanisms of tigecycline resistance.

Methods: We gathered 31 unduplicated strains of tigecycline-resistant from six hospitals nationwide. Antimicrobial susceptibility testing, phenotypic detection, and PCR identification were performed first, followed by homology analysis using MLST and PFGE.

Complex evolutionary trajectories in vivo of two novel KPC variants conferring ceftazidime-avibactam resistance.

More and more ceftazidime-avibactam-resistant KPC-producing Klebsiella pneumoniae have been reported with its widespread use, and the detection rate of KPC variants has increased dramatically. However, the evolutionary mechanism and fitness effects during KPC mutation remained unknown. Here, we report the complex in vivo evolutionary trajectories of two novel KPC variants, KPC-155 (L169P/GT242A) and KPC-185 (D179Y/GT242A), from K.

Dynamic evolution of ceftazidime-avibactam resistance from a single patient through the IncX3_NDM-5 plasmid transfer and bla mutation.

The rapid dissemination of carbapenem-resistant Enterobacterales (CRE) especially carbapenem-resistant Klebsiella pneumoniae (CRKP) poses a great threat to global public health. Ceftazidime-avibactam, a novel β-lactam/β-lactamase inhibitor combination, has been widely used due to its excellent antibacterial activity against KPC-producing K. pneumoniae.

Comparison of three colloidal gold immunoassays and GeneXpert Carba-R for the detection of variants.

The increasing use of ceftazidime-avibactam has led to the emergence of a wide range of ceftazidime-avibactam-resistant variants. Particularly, the conventional carbapenemase phenotypic assay exhibited a high false-negative rate for KPC-2 variants. In this study, three colloidal gold immunoassays, including the Gold Mountainriver CGI test, Dynamiker CGI test and NG-Test CARBA5, and GeneXpert Carba-R, were used to detect the presence of KPC-2 carbapenemase and its various variants in 42 strains.

Molecular mechanisms responsible KPC-135-mediated resistance to ceftazidime-avibactam in ST11-K47 hypervirulent .

Ceftazidime-avibactam resistance attributable to the gene mutation is increasingly documented in clinical settings. In this study, we characterized the mechanisms leading to the development of ceftazidime-avibactam resistance in ST11-K47 hypervirulent that harboured the gene. This strain possessed fimbriae and biofilm, demonstrating pathogenicity.

In vitro mimicry of in vivo KPC mutations by ceftazidime-avibactam: phenotypes, mechanisms, genetic structure and kinetics of enzymatic hydrolysis.

Ceftazidime-avibactam (CZA) is employed for the treatment of infections caused by carbapenemase-producing (KPC-KP). Resistance to CZA is frequently linked to point mutations in the . We conducted simulations of mutations using CZA.

Carbapenem-resistant Klebsiella pneumoniae capsular types, antibiotic resistance and virulence factors in China: a longitudinal, multi-centre study.

Epidemiological knowledge of circulating carbapenem-resistant Klebsiella pneumoniae (CRKP) is needed to develop effective strategies against this public health threat. Here we present a longitudinal analysis of 1,017 CRKP isolates recovered from patients from 40 hospitals across China between 2016 and 2020. Virulence gene and capsule typing revealed expansion of CRKP capsule type KL64 (59.

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 , , , , and Acinetobacter baumannii, remained largely unchanged.

carbapenemase variants: the new threat to global public health.

carbapenemase (KPC) variants, which refer to the substitution, insertion, or deletion of amino acid sequence compared to wild type, have reduced utility of ceftazidime-avibactam (CZA), a pioneer antimicrobial agent in treating carbapenem-resistant infections. So far, more than 150 variants have been reported worldwide, and most of the new variants were discovered in the past 3 years, which calls for public alarm. The KPC variant protein enhances the affinity to ceftazidime and weakens the affinity to avibactam by changing the KPC structure, thereby mediating bacterial resistance to CZA.

Assessment of cefiderocol disk diffusion versus broth microdilution results when tested against complex clinical isolates.

Carbapenem-resistant is a major global health concern due to its high prevalence and limited treatment options. Cefiderocol is the only novel Food and Drug Administration (FDA)-approved β-lactam agent for the salvage treatment of carbapenem-resistant infection. Currently, a commercial automated susceptibility testing panel of cefiderocol is unavailable.

A modified Kirby-Bauer disc diffusion (mKB) method for accurately testing tigecycline susceptibility: a nation-wide multicenter comparative study.

Tigecycline is one of the important antibiotics available for treating infection caused by multiple-drug resistant pathogens. However, the conventional AST methods which are commonly used in clinical microbiology laboratories usually lead to false intermediate or resistant results in testing tigecycline susceptibility, and further mislead clinical antimicrobial therapies. The modified Kirby-Bauer disc diffusion (mKB) method was performed based on the traditional standard Kirby-Bauer disc diffusion (sKB) method.

Setting of the tentative epidemiological cut-off values of contezolid for Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae and Streptococcus agalactiae.

Objectives: To set the tentative epidemiological cut-off values (TECOFFs) of contezolid for Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, Streptococcus pneumoniae and Streptococcus agalactiae based on the distributions of inhibition zone diameters and MICs.

Methods: A total of 1358 non-duplicate clinical isolates of Gram-positive bacteria were collected from the patients across China from 2017 to 2020. The isolates were tested for susceptibility to contezolid and the comparator linezolid by broth microdilution and disc diffusion methods in three microbiology laboratories.

Performance of Ceftazidime-Avibactam 30/20-μg and 10/4-μg Disks for Susceptibility Testing of and Pseudomonas aeruginosa.

Ceftazidime-avibactam, a new β-lactam-β-lactamase inhibitor combination, is active against multidrug-resistant and Pseudomonas aeruginosa isolates and has became available for clinical use in China in the latter half of 2019. In this study, we evaluated the performance of the disk diffusion test with ceftazidime-avibactam 10/4-μg and 30/20-μg disks, compared with the reference broth microdilution method, with a collection of 467 and 182 P. aeruginosa nonduplicate clinical isolates.

Check the melting temperature of the FilmArray BCID panel to avoid missed detection of vanM-type enterococci.

Purpose: We aimed to evaluate whether the FilmArray blood culture identification (BCID) panel holds the ability to detect vanM-type vancomycin-resistant enterococci (VRE) clinical isolates effectively.

Methods: Twenty VRE clinical strains, including 10 vanA-type VRE and 10 vanM-type VRE, were collected from patients in five tertiary hospitals, Shanghai, China. By conventional PCR and sequencing, the strains were identified and van genotypes were confirmed.

Identification of KPC-112 from an ST15 Klebsiella pneumoniae Strain Conferring Resistance to Ceftazidime-Avibactam.

Ceftazidime-avibactam is an effective antibiotic combination of a β-lactam and a β-lactamase inhibitor against Klebsiella pneumoniae-carbapenemase (KPC)-producing . Despite a relatively low resistance rate, reports of resistance to ceftazidime-avibactam mainly caused by the mutations in KPC have increased in recent years. Here, we report a ceftazidime-avibactam-resistant and carbapenem-susceptible Klebsiella pneumoniae strain carrying a novel KPC variant, KPC-112, which differs from KPC-2 by 4-amino-acid deletions at Ambler positions 166L/167E and 242G/243T.

Activities of Eravacycline, Tedizolid, Norvancomycin, Nemonoxacin, Ceftaroline, and Comparators against 1,871 and 1,068 Species Isolates from China: Updated Report of the CHINET Study 2019.

To evaluate the activities of eravacycline, tedizolid, nemonoxacin, norvancomycin, and ceftaroline against Staphylococcus and species isolates were collected as part of the China Antimicrobial Surveillance Network (CHINET) in 2019 to provide susceptibility data for Staphylococcus spp. and spp. for their future development and application in clinical practice.

High Prevalence and Overexpression of Fosfomycin-Resistant Gene X in From China.

i are one of the main causes of gastrointestinal tract infections in the healthcare system and can develop resistance to fosfomycin through plasmid or chromosomally encoded fosfomycin resistance genes. To investigate the mechanisms of fosfomycin resistance, a total of 4,414 clinical isolates of non-replicated clinical enterococci collected from 62 hospitals in 26 provinces or cities in China were tested. Antibiotic susceptibility testing, detection of fosfomycin resistance genes, and cloning of the X gene were done.

First Report of , , and Carrying Showing High-Level Resistance to Carbapenems.

The prevalence of carbapenem-resistant is increasing. Although carbapenemase production is the main resistance mechanism of to carbapenems, there are still some reports of non-carbapenemase-producing showing high-level resistance to carbapenems. In this study, we had also isolated a carbapenemase-negative carbapenem-resistant L204 from a patient with an asymptomatic urinary tract infection.

Activity of New β-Lactam-β-Lactamase Inhibitor Combinations and Comparators against Clinical Isolates of Gram-Negative Bacilli: Results from the China Antimicrobial Surveillance Network (CHINET) in 2019.

Novel β-lactam-β-lactamase inhibitor combinations (BLBLIs) are in clinical development for the treatment of infections caused by carbapenem-resistant and difficult-to-treat resistant (DTR) (defined as resistance to all tested β-lactams and fluoroquinolones) Gram-negative bacilli. This study evaluated the activities of cefepime-zidebactam, ceftazidime-avibactam, cefepime-tazobactam, ceftolozane-tazobactam, and other comparators against 4,042 nonduplicate Gram-negative clinical isolates collected from different regions of China (46 hospitals) in 2019. Based on the pharmacokinetic-pharmacodynamic (PK-PD) breakpoints, cefepime-zidebactam inhibited 98.

Characterization of the First Carbapenem-Resistant Harboring in China.

With the wide use of carbapenems, carbapenem-resistant have been increasingly reported worldwide. In this study, one -positive strain was isolated from the blood culture of a patient with a bloodstream infection in China, which was its first clinical report outside Pakistan. Species identification of was initially performed using MALDI-TOF/MS and further confirmed by 16S rRNA gene and housekeeping gene sequencing.

Asp50Glu mutation in MurA results in fosfomycin resistance in Enterococcus faecium.

Objectives: Enterococcus faecium is one of the important pathogens causing nosocomial infection, which can be resistant to fosfomycin by obtaining the plasmid-encoded fosfomycin resistance genes, and the mutation of MurA protein encoded by chromosome is a newly discovered fosfomycin resistance mechanism in recent years.

Methods: In this study, we found a fosfomycin-resistant clinical isolate of E. faecium Efm_1415 with fosfomycin MIC of 512 mg/L, carrying Asp50Glu mutant of MurA protein, which was never reported before.

Ceftazidime-Avibactam in Combination with Imipenem as Salvage Therapy for ST11 KPC-33-Producing .

A 22-year-old man, after a hematopoietic stem cell transplant, suffered long-term pneumonia caused by -positive and positive alternately and finally achieved pathogenic clearance and improvement of clinical infectious conditions after using ceftazidime-avibactam in combination with imipenem as salvage therapy. This case provides a reference for treating infection caused by with a KPC variant in countries lacking new antimicrobial agents.