Biomedical subjects

Jianping Jiang

Publications and source records attributed to Jianping Jiang.

3 recordsLinked to original sources

PubMed2026

Genomic analysis of community-associated multidrug-resistant Klebsiella quasipneumoniae subsp. similipneumoniae and the identification of the ST2059-KL1 clone in the U.S.

UNLABELLED: Klebsiella quasipneumoniae subsp. similipneumoniae is an important member of the K. pneumoniae species complex (KpSC) and is increasingly reported as multidrug-resistant (MDR) in healthcare- and community-associated infections. Since clinical laboratories do not routinely distinguish K. quasipneumoniae subsp. similipneumoniae from K. pneumoniae, national prevalence estimates, particularly for MDR, are lacking. In this study, a total of 2,006 community-associated MDR KpSC isolates were collected from 42 U.S. states, with 30 K. quasipneumoniae subsp. similipneumoniae isolates originating from 12 states identified using whole genome sequencing. All isolates were resistant to ceftriaxone and exhibited high rates of resistance to other antimicrobial agents, including ampicillin-sulbactam (56.7%, 17/30), levofloxacin (75.9%, 22/29), and trimethoprim-sulfamethoxazole (53.3%, 16/30). Notably, five isolates were also carbapenem-resistant. Genomic analysis resolved 10 sequence types (STs), with ST2059 (n = 13) and ST414 (n = 9) predominating. Ceftriaxone resistance in most isolates (90%, 27/30) was conferred by an extended-spectrum β-lactamase gene, predominantly blaCTX-M-15 (73.3%, 22/30); the remaining isolates carried either a carbapenemase (blaKPC-3) or an AmpC β-lactamase (blaCMY-2). Nanopore sequencing identified blaCTX-M-15 harbored on two types of IncFIB(Kpn3) antimicrobial resistance (AMR) plasmids, either with or without the conjugative tra gene cluster. Interestingly, the KL1 locus, associated with canonical hypervirulent K. pneumoniae strains, was detected in all ST2059 isolates. Further analysis of public genomic data showed that the KL1 locus is widely distributed across KpSC. KL1 phylogenetic analyses indicated frequent intrasubspecies recombination but limited intersubspecies exchange of KL1. The identification of the dominant MDR K. quasipneumoniae subsp. similipneumoniae KL1-ST2059 clone in the U.S. underscores the importance of ongoing genomic surveillance. IMPORTANCE: Klebsiella quasipneumoniae subsp. similipneumoniae is an underrecognized member of the Klebsiella pneumoniae species complex that is frequently misidentified in clinical laboratories, leading to an incomplete understanding of its role in antimicrobial resistance. In this study, we used large-scale genomic surveillance of community-associated multidrug-resistant isolates across the U.S. to identify this subspecies as a reservoir of clinically relevant resistance plasmids. Notably, we detected a widely distributed ST2059 lineage carrying the K1 capsular locus, a feature traditionally associated with hypervirulent K. pneumoniae. These findings highlight the convergence of resistance and virulence-associated traits in an overlooked species and underscore the need for genomic surveillance to monitor emerging high-risk lineages in community settings.

Drug Resistance, Multiple, Bacterial↗

PubMed2026

Loss of O-antigen due to wbbL mutations is common and associated with increased mortality in Escherichia coli bloodstream infections.

Escherichia coli bloodstream infections are common and associated with high mortality. A key feature of E. coli is the lipopolysaccharide (LPS) O-antigen, which contributes to immune evasion during invasive infection. We analyzed serial isolates from patients with relapsed E. coli bacteremia and identified frequent disruption of O-antigen synthesis due to mutations in wbbL, resulting in a rough LPS phenotype. Rough LPS isolates were more serum sensitive and less pathogenic in mice. Despite this apparent attenuation, 11 of 61 (18%) E. coli sequence type 131 bloodstream isolates in our cohort harbored disruptive wbbL mutations and were associated with significantly worse clinical outcomes, including septic shock and mortality. Using a murine model of recurrent bacteremia, we show that rough LPS isolates partially evade protective immunity generated against smooth LPS E. coli, highlighting the importance of host immune context in invasive disease.

O Antigens↗

PubMed2026

Muscular fiber properties and multi-omics investigation of larval and adult locomotor muscle in Microhyla fissipes.

During metamorphosis, Microhyla fissipes undergoes a critical transition from an aquatic to a terrestrial lifestyle, accompanied by significant remodeling of skeletal muscle. Notably, larval tail muscle degenerates, while adult hindlimb muscle develops. However, the molecular mechanisms that orchestrate these muscle type-specific adaptations to the changing environment remain unclear. In this study, histological observation, transcriptomics, and metabolomics were integrated to compare locomotor muscles from two stages: larval muscle from tail versus adult muscle from hindlimb. Our results revealed that adult muscle fibers exhibited reduced diameter and shorter sarcomere length compared to those of tadpoles. Transcriptomic analysis identified 4103 differentially expressed genes (DEGs), including 2182 up-regulated and 1921 down-regulated genes. Up-regulated genes were mainly involved in energy metabolism and cellular homeostasis pathways, including PPAR signaling and oxidative phosphorylation, whereas down-regulated genes were associated with carbohydrate metabolism and cell proliferation pathways, such as glycolysis/gluconeogenesis and PI3K-Akt signaling. Metabolic profiling indicated a metabolic shift from anaerobic to aerobic energy production, with 57 differential metabolites identified, mainly involved in protein metabolism and insulin-related pathways. Integrated multi-omics analysis further highlighted the AMPK and FoxO signaling pathways play key roles in this process. In conclusion, our findings demonstrate that the metabolic and structural differences between larval and adult skeletal muscles are mediated by AMPK- and FoxO-dependent signaling pathways, providing novel insights into the molecular mechanisms underlying adaptive development and locomotor transition in anuran amphibians.

Animals↗