Ceftazidime/Avibactam Resistance in Carbapenemase-Producing Klebsiella pneumoniae.

We identified a novel ceftazidime/avibactam resistance mechanism in sequence type 11 Klebsiella pneumoniae carbapenemase 2-producing K. pneumoniae. Plasmid recombination and chromosomal integration formed a novel virulence plasmid and provided an additional promoter for bla, leading to bla overexpression and ceftazidime/avibactam resistance.

Dissecting the genotypic features of a fluoroquinolone-resistant ST316 sublineage causing ear infections in Shanghai, China.

Limited information is available regarding the genomic characteristics of causing ear infections. Our aim is to characterize the genotypic features of an emerging ST316 sublineage causing aural infections in Shanghai. A total of 199 ear swab isolates were subjected to whole genome sequencing (WGS).

Antibiotic Exposure during the Preceding Six Months Is Related to Intestinal ESBL-Producing Enterobacteriaceae Carriage in the Elderly.

Intestinal carriage of extended-spectrum β-lactamase-producing (ESBL-PE carriage) poses a health risk to the elderly. It was aimed to study the prevalence and the risk factors of intestinal ESBL-PE carriage in the elderly. An observational study of a 921-elderly cohort was examined at health checkup for intestinal ESBL-PE carriage at a tertiary medical center in Shanghai.

The Vancomycin Resistance-Associated Regulatory System VraSR Modulates Biofilm Formation of Staphylococcus epidermidis in an -Dependent Manner.

The two-component system VraSR responds to the cell wall-active antibiotic stress in Staphylococcus epidermidis. To study its regulatory function in biofilm formation, a deletion mutant (Δ) was constructed using S. epidermidis strain 1457 (SE1457) as the parent strain.

Molecular Characteristics, Antimicrobial Resistance, and Biofilm Formation of Isolated from Patients with Aural Infections in Shanghai, China.

Purpose: To investigate molecular characteristics, antimicrobial resistance, and biofilm formation ability of strains isolated from patients with aural infections.

Methods: Isolates (n = 199) were collected from ear discharges of patients with aural infections from January 2019 to December 2020. Antimicrobial susceptibility testing was performed according to the Clinical and Laboratory Standards Institute guidelines.

Microbial Spectrum and Resistance Patterns in Ocular Infections: A 15-Year Review in East China.

Purpose: To report antibiotic resistance rates and trends of common ocular isolates collected over a 15-year period.

Methods: We collected 3533 isolates from July 1, 2005 to July 31, 2020. Antibiotic sensitivity was determined according to the guidelines of the Clinical and Laboratory Standards Institute.

The Predominance of Strain Replacement Among Enterobacteriaceae Pairs With Emerging Carbapenem Resistance During Hospitalization.

Isolates of Enterobacteriaceae collected from the same patient can lose carbapenem susceptibility during antimicrobial therapy, but little attention has been given to how this conversion takes place. In the current study, we retrospectively analyzed microbiological and clinical data from patients with enterobacterial infections at a tertiary hospital in Shanghai, China. After screening 4795 patients and 7120 Enterobacteriaceae isolates over the 3-year study period, we found the change from carbapenem susceptible to carbapenem resistant in 41 pairs of isolates, of which 35 pairs (85.

The Colonization of Carbapenem-Resistant Klebsiella pneumoniae: Epidemiology, Resistance Mechanisms, and Risk Factors in Patients Admitted to Intensive Care Units in China.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) has become a threat to public health, most notably as a superbug causing nosocomial infections. Patients in the intensive care unit (ICU) are at increased risk of hospital-acquired K pneumoniae infection, especially CRKP. This study was conducted to investigate the frequency of gastrointestinal and nasopharyngeal K pneumoniae colonization and its contribution to infections in ICU patients.

Isobaric tags for relative and absolute quantitation proteomics analysis of gene regulation by SprC in Staphylococcus aureus.

Aim: To explore the complete gene networks regulated by small RNA SprC and its targets in Staphylococcus aureus.

Materials & Methods: The isobaric tags for relative and absolute quantitation and bioinformatic methods were utilized to identify and analyze the target proteins affected by SprC in S. aureus N315.

In vivo development of tigecycline resistance in Klebsiella pneumoniae owing to deletion of the ramR ribosomal binding site.

Tigecycline resistance is emerging among Klebsiella pneumoniae, but knowledge regarding in vivo development of tigecycline resistance is limited. Here we report a new mechanism of tigecycline resistance in K. pneumoniae that evolved during tigecycline therapy.

High ceftazidime hydrolysis activity and porin OmpK35 deficiency contribute to the decreased susceptibility to ceftazidime/avibactam in KPC-producing Klebsiella pneumoniae.

Objectives: To investigate mechanisms for the decreased susceptibility to ceftazidime/avibactam in KPC-producing Klebsiella pneumoniae (KPC-KP).

Methods: A total of 24 isolates, 8 each with ceftazidime/avibactam MICs of 4-8, 1-2 and ≤0.5 mg/L, were randomly selected from 214 clinical isolates of KPC-KP, and the β-lactamase hydrolysis activity and porin expression profiles were determined.

Clinical and Genomic Analysis of Liver Abscess-Causing Identifies New Liver Abscess-Associated Virulence Genes.

Hypervirulent variants of (hvKp) that cause invasive community-acquired pyogenic liver abscess (PLA) have emerged globally. Little is known about the virulence determinants associated with hvKp, except for the virulence genes and siderophores () carried by the pK2044-like large virulence plasmid. Here, we collected most recent clinical isolates of hvKp from PLA samples in China, and performed clinical, molecular, and genomic sequencing analyses.

CTX-M-190, a Novel β-Lactamase Resistant to Tazobactam and Sulbactam, Identified in an Escherichia coli Clinical Isolate.

A novel β-lactamase, CTX-M-190, derived from CTX-M-55 by a single substitution of Ser for Thr at position 133 (Ser133Thr), was identified in a natural Escherichia coli clinical isolate. CTX-M-190 exhibited potent hydrolytic activity against cefotaxime, with a k/K ratio of 14.5 μM s, and was highly resistant to inhibition by the β-lactamase inhibitors tazobactam and sulbactam, whose 50% inhibitory concentrations were 77- and 55-fold higher, respectively, for CTX-M-190 than for CTX-M-55.

Acquisition of Carbapenemase Gene in Multiple Species of through Horizontal Transfer of Insertion Sequence or Plasmid.

Current worldwide spread of carbapenem resistance in Enterobacteriaceae constitutes a critical public health threat. This study aims to investigate how carbapenem resistance is acquired in Enterobacteriaceae in patients during antimicrobial therapy. Clinical strains from the same anatomical site of the same patients that converted from carbapenem-susceptible to resistant during antimicrobial therapy and showed identical or similar PFGE patterns were identified.

Characterization of a Novel IncHI2 Plasmid Carrying Tandem Copies of blaCTX-M-2 in a fosA6-Harboring Escherichia coli Sequence Type 410 Strain.

The extended-spectrum β-lactamase gene bla is mainly associated with ISCR1 embedded in complex sul1-type integrons, but information on the genetic context of plasmids harboring the ISCR1-bla module remains limited. In this study, a bla-harboring plasmid (pYD786-1) belonging to the sequence type 2 (ST2)-IncHI2 plasmid type and isolated from an Escherichia coli ST410 clinical strain was sequenced and analyzed. pYD786-1 belongs to the APEC-O1-R-type IncHI2 plasmids, which are widely distributed in human, poultry, and livestock strains.

Typing of Panton-Valentine Leukocidin-Encoding Phages and lukSF-PV Gene Sequence Variation in Staphylococcus aureus from China.

Panton-Valentine leukocidin (PVL, encoded by lukSF-PV genes), a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in Staphylococcus aureus has been reported around the globe. However, the data on PVL-encoding phage types, lukSF-PV gene variation and chromosomal phage insertion sites for PVL-positive S.

Klebsiella pneumoniae: Development of Carbapenem Resistance due to Acquisition of bla NDM-1 During Antimicrobial Therapy in Twin Infants with Pneumonia.

Objectives: To identify the mechanism of in vivo development of carbapenem resistance in Klebsiella pneumoniae.

Methods: Seven sequential isolates of K. pneumoniae were obtained from twin infants with pneumonia.

Four carbapenem-resistant gram-negative species carrying distinct carbapenemases in a single patient.

Carbapenem-resistant Escherichia coli, Klebsiella pneumoniae, Enterobacter aerogenes, and Acinetobacter baumannii were isolated from a single patient, each producing different carbapenemases (NDM-1, KPC-2, IMP, and OXA-23, respectively). The NDM-1-producing E. coli strain was preceded by a clonally related carbapenem-susceptible strain a month earlier, suggesting in vivo acquisition of blaNDM-1.

Prevalence of fusB in Staphylococcus aureus clinical isolates.

Fusidic acid (FA) resistance in Staphylococcus aureus markedly varied among different regions. Few data for FA resistance are available in China. In this study, FA susceptibility testing was performed, and the prevalence of fusB and fusC in 116 clinical isolates of S.

Outbreak of pulmonary infection caused by Klebsiella pneumoniae isolates harbouring blaIMP-4 and blaDHA-1 in a neonatal intensive care unit in China.

Outbreaks caused by Klebsiella pneumoniae producing carbapenemases and other β-lactamases have been reported. Four neonates admitted to a neonatal intensive care unit (NICU) in a Chinese hospital developed respiratory infection while receiving intensive care. In all four cases, multidrug-resistant K.

Molecular characterization and antimicrobial susceptibility of nasal Staphylococcus aureus isolates from a Chinese medical college campus.

Staphylococcus aureus colonization and infection occur more commonly among persons living or working in crowded conditions, but characterization of S. aureus colonization within medical communities in China is lacking. A total of 144 (15.

Monoclonal antibodies against accumulation-associated protein affect EPS biosynthesis and enhance bacterial accumulation of Staphylococcus epidermidis.

Because there is no effective antibiotic to eradicate Staphylococcus epidermidis biofilm infections that lead to the failure of medical device implantations, the development of anti-biofilm vaccines is necessary. Biofilm formation by S. epidermidis requires accumulation-associated protein (Aap) that contains sequence repeats known as G5 domains, which are responsible for the Zn(2+)-dependent dimerization of Aap to mediate intercellular adhesion.

High prevalence of extended-spectrum beta lactamases among Salmonella enterica Typhimurium isolates from pediatric patients with diarrhea in China.

We investigated the extended-spectrum beta lactamases among 62 Salmonella enterica Typhimurium isolates recovered from children with diarrhea in a Chinese pediatric hospital. A large proportion of S. enterica Typhimurium isolates were resistant to multiple antimicrobial agents, including ampicillin (90.