Mutations in porin LamB contribute to ceftazidime-avibactam resistance in KPC-producing Klebsiella pneumoniae.

Ceftazidime-avibactam (CAZ-AVI) shows promising activity against carbapenem-resistant Klebsiella pneumoniae (CRKP), however, CAZ-AVI resistance have emerged recently. Mutations in KPCs, porins OmpK35 and/or OmpK36, and PBPs are known to contribute to the resistance to CAZ-AVI in CRKP. To identify novel CAZ-AVI resistance mechanism, we generated 10 CAZ-AVI-resistant strains from 14 CAZ-AVI susceptible KPC-producing K. pneumoniae (KPC-Kp) strains through in vitro multipassage resistance selection using low concentrations of CAZ-AVI. Comparative genomic analysis for the original and derived mutants identified CAZ-AVI resistance-associated mutations in KPCs, PBP3 (encoded by ftsI), and LamB, an outer membrane maltoporin. CAZ-AVI susceptible KPC-Kp strains became resistant when complemented with mutated blaKPC genes. Complementation experiments also showed that a plasmid borne copy of wild-type lamB or ftsI gene reduced the MIC value of CAZ-AVI in the induced resistant strains. In addition, blaKPC expression level increased in four of the six CAZ-AVI-resistant strains without KPC mutations, indicating a probable association between increased blaKPC expression and increased resistance in these strains. In conclusion, we here identified a novel mechanism of CAZ-AVI resistance associated with mutations in porin LamB in KPC-Kp

Global emergence of a hypervirulent carbapenem-resistant <i>Escherichia coli </i>ST410 clone

Carbapenem-resistant Escherichia coli (CREC) ST410 has recently emerged as a major global health problem. Here, we report a shift in CREC prevalence in Chinese hospitals between 2017 and 2021 with ST410 becoming the most commonly isolated sequence type. Genomic analysis identifies a hypervirulent CREC ST410 clone, B5/H24RxC, which caused two separate outbreaks in a children's hospital. It may have emerged from the previously characterised B4/H24RxC in 2006 and has been isolated in ten other countries from 2015 to 2021. Compared with B4/H24RxC, B5/H24RxC lacks the blaOXA-181-bearing X3 plasmid, but carries a F-type plasmid containing blaNDM-5. Most of B5/H24RxC also carry a high pathogenicity island and a novel O-antigen gene cluster. We find that B5/H24RxC grew faster in vitro and is more virulent in vivo. The identification of this newly emerged but already globally disseminated hypervirulent CREC clone, highlights the ongoing evolution of ST410 towards increased resistance and virulence. </p

The anti-inflammatory cytokine IL-22 exhibited a proinflammatory effect in the ovary aiding with the parturition of ovoviviparous black rockfish (Sebastes schlegelii)

IntroductionAs a unique type of immunological process, pregnancy and subsequent parturition are associated with a series of inflammatory events. As an anti-inflammatory cytokine, IL-22 has been proven to participate in the parturition process in mammals. However, less is known about ovoviviparous teleosts. To investigate the role of IL-22 in fish parturition, black rockfish, an ovoviviparous teleost, was used. This fish is unique in that it provides over 60% nutrition supply for over 50 thousand embryos at the same time though a placenta-like structure during pregnancy while delivering all fries in two hours.MethodsSequence alignment, phylogenetic tree analysis and homology modeling were performed on IL-22 and its receptor. In situ hybridization demonstrated ovarian localization of il22 and il22r1. The protein of rIL-22 was obtained through the prokaryotic expression. RNA-seq analysis was performed on black rockfish ovarian cells treated with rIL-22.ResultsIn situ hybridization results showed that both il22 and il22ra1 were localized in the perinatal follicle layer and embryonic envelope. The il22 expression level was significantly increased during parturition compared to before and after parturition (P&lt;0.05). To further understand the mechanism of IL-22 in parturition, rIL-22 was obtained. The downstream variation genes in primary cultured ovarian cells in the perinatal period were analyzed according to the transcriptomic results. A total of 168 differentially expressed genes (DEGs) were identified in the rIL-22 group compared with the PBS control group (padj &lt; 0.05 and |log2FoldChange| 1). Of those, 134 DEGs were identified in the LPS and rIL-22 treatment groups, including chemokine, cytokine, and PG synthesis. 34 DEGs were mainly identified in immune-related pathways and reorganization of the cytoskeleton responded only to rIL-22 stimulation but not LPS. KEGG pathways mainly included immune response, PG synthesis, cell death and angiogenesis (p value &lt; 0.05).DiscussionTaken together, our results indicated that IL-22 plays an important role in the parturition of black rockfish by upregulating PG synthesis and increasing chemokine, proinflammatory factor, as well as PG synthetase levels

Molecular characterization and expression patterns of nuclear androgen receptors in the ovoviviparous black rockfish Sebastes schlegelii

nARs are ligand-activated transcription factors associated with gonadal development and reproductive regulation. In this study, two nuclear androgen receptor genes (ara and arb) were cloned from an ovoviviparous teleost, black rockfish (Sebastes schlegelii). The phylogenetic analysis of nARs showed that nARα and nARβ clustered into teleost nARα and nARβ, respectively, but differed from the nARs of tetrapods. Four module domains of the nuclear receptor superfamily are present in the black rockfish nARs, an N-terminal domain (NTD), a DNA-binding domain (DBD), a hinge region (HR) and a ligand-binding domain (LBD). Among the four domains, only the DBD and LBD of nARα and nARβ are relatively conserved. Tissue distribution analysis revealed that ara was mainly expressed in the gonad, muscle, intestine and kidney in males and in female, while arb was mainly detected in the gonad, followed by the intestine, kidney and head kidney. During the gonadal development process, the expression levels of ara and arb were significantly decreased from the regenerating to late stages of spermatogenesis and significantly increased in the degeneration stage in the testis (P<0.05). In the ovary, the expression levels of ara and arb were not significantly different in different stages. In situ hybridization revealed that in black rockfish, both ara and arb transcripts were localized to the Sertoli cells of the testis in black rockfish. In general, the present study is the first to characterize and analyse the expression of nuclear androgen receptors, including ara and arb, in black rockfish

Intermetallic Palladium–Zinc Nanoparticles for the Ultraselective Hydrogenative Rearrangement of Furan Compounds

The tandem hydrogenative rearrangement of furan aldehydes/ketones into cyclopentanones is crucial for synthesizing biobased fine chemicals but remains challenging because of the complexity of the tandem reaction network. Herein, intermetallic PdZn nanoparticle-supported catalysts were prepared, which showed a high catalytic efficiency for synthesizing 3-methyl cyclopentanone with a 96.3% yield from 5-methyl furfural at the hitherto lowest temperature of 120 °C. Furthermore, they exhibited catalytic generality for the synthesis of cyclopentanones with yields above 90% from other furan aldehydes (i.e., furfural, 5-hydroxymethyl furfural, and 5-ethyl furfural) and furan ketones (i.e., 2-furan methyl ketone and 2-furan ethyl ketone). Investigations into the catalytic mechanism showed that H2 was heterolytically activated on the Pd–Zn pair to form H––Pd–Zn–H3O+ via an ionic water-mediated pathway, which not only functioned as unconventional active sites for the carbonyl group hydrogenation step but also provided Brønsted acid sites for ring opening and intramolecular aldol condensation steps. This study presents an exciting strategy for the bifunctional catalysis of challenging substrates by generating transient H+–H– pairs using advanced intermetallic alloy catalysts

Adaptive Evolution Compensated for the Plasmid Fitness Costs Brought by Specific Genetic Conflicts

New Delhi metallo-β-lactamase (NDM)-carrying IncX3 plasmids is important in the transmission of carbapenem resistance in Escherichia coli. Fitness costs related to plasmid carriage are expected to limit gene exchange; however, the causes of these fitness costs are poorly understood. Compensatory mutations are believed to ameliorate plasmid fitness costs and enable the plasmid’s wide spread, suggesting that such costs are caused by specific plasmid–host genetic conflicts. By combining conjugation tests and experimental evolution with comparative genetic analysis, we showed here that the fitness costs related to ndm/IncX3 plasmids in E. coli C600 are caused by co-mutations of multiple host chromosomal genes related to sugar metabolism and cell membrane function. Adaptive evolution revealed that mutations in genes associated with oxidative stress, nucleotide and short-chain fatty acid metabolism, and cell membranes ameliorated the costs associated with plasmid carriage. Specific genetic conflicts associated with the ndm/IncX3 plasmid in E. coli C600 involve metabolism and cell-membrane-related genes, which could be ameliorated by compensatory mutations. Collectively, our findings could explain the wide spread of IncX3 plasmids in bacterial genomes, despite their potential cost

Antibiotic Prescription Patterns for Acute Respiratory Infections in Rural Primary Healthcare Settings in Guangdong, China: Analysis of 162,742 Outpatient Prescriptions

Overuse and inappropriate use of antibiotics are important contributors to bacterial antimicrobial resistance (AMR), especially in ambulatory primary healthcare (PHC) settings in low- and middle-income countries. This study aimed to investigate antibiotic prescription patterns among patients with acute respiratory infections (ARIs) in rural PHC facilities in the Guangdong Province, China. A total of 444,979 outpatient prescriptions were extracted from the electronic medical record system of 35 township health centers (THCs) and 2 community health centers (CHCs) between November 2017 and October 2018. We used the chi-square test to analyze the antibiotic prescription patterns and binary logistic regression to explore patient-related factors associated with antibiotic prescriptions. Of the 162,742 ARI prescriptions, 85.57% (n = 139,259) included at least one antibiotic. Among the 139,259 prescriptions with antibiotics, 37.82% (n = 52,666) included two or more antibiotics, 55.29% (n = 76,993) included parenteral antibiotics, and 56.62% (n = 78,852) included Watch group antibiotics. The binary logistic regression indicated that (1) female patients were slightly less likely to be prescribed antibiotics than males (adjusted odds ratio (OR) = 0.954, 95% confidence interval [CI] [0.928–0.981]; p = 0.001); and (2) compared to patients aged ≤5 years, those who were 6–15 years old (adjusted OR = 1.907, 95% CI [1.840–1.978]; p p 60 years old (adjusted OR = 1.915, 95% CI [1.810–2.026]; p < 0.001) were more likely to be prescribed antibiotics. The overuse and irrational use of antibiotics in PHC settings remain major healthcare challenges in rural Guangdong. Thus, it is imperative to implement targeted antimicrobial stewardship (AMS) policies to address this problem

Global emergence of a hypervirulent carbapenem-resistant Escherichia coli ST410 clone

Acknowledgements: This work was undertaken as part of the DETECTIVE research project funded by the National Natural Science Foundation of China (8181101332) and the Medical Research Council (MR/S013660/1). W.v.S. was also supported by a Wolfson Research Merit Award (WM160092). We thank Dr. Andries J. van Tonder for guidance on the bioinformatics analysis.Funder: National Natural Science Foundation of China (National Science Foundation of China); doi: https://doi.org/10.13039/501100001809Carbapenem-resistant Escherichia coli (CREC) ST410 has recently emerged as a major global health problem. Here, we report a shift in CREC prevalence in Chinese hospitals between 2017 and 2021 with ST410 becoming the most commonly isolated sequence type. Genomic analysis identifies a hypervirulent CREC ST410 clone, B5/H24RxC, which caused two separate outbreaks in a children’s hospital. It may have emerged from the previously characterised B4/H24RxC in 2006 and has been isolated in ten other countries from 2015 to 2021. Compared with B4/H24RxC, B5/H24RxC lacks the blaOXA-181-bearing X3 plasmid, but carries a F-type plasmid containing blaNDM-5. Most of B5/H24RxC also carry a high pathogenicity island and a novel O-antigen gene cluster. We find that B5/H24RxC grew faster in vitro and is more virulent in vivo. The identification of this newly emerged but already globally disseminated hypervirulent CREC clone, highlights the ongoing evolution of ST410 towards increased resistance and virulence

DataSheet_2_The anti-inflammatory cytokine IL-22 exhibited a proinflammatory effect in the ovary aiding with the parturition of ovoviviparous black rockfish (Sebastes schlegelii).zip

IntroductionAs a unique type of immunological process, pregnancy and subsequent parturition are associated with a series of inflammatory events. As an anti-inflammatory cytokine, IL-22 has been proven to participate in the parturition process in mammals. However, less is known about ovoviviparous teleosts. To investigate the role of IL-22 in fish parturition, black rockfish, an ovoviviparous teleost, was used. This fish is unique in that it provides over 60% nutrition supply for over 50 thousand embryos at the same time though a placenta-like structure during pregnancy while delivering all fries in two hours.MethodsSequence alignment, phylogenetic tree analysis and homology modeling were performed on IL-22 and its receptor. In situ hybridization demonstrated ovarian localization of il22 and il22r1. The protein of rIL-22 was obtained through the prokaryotic expression. RNA-seq analysis was performed on black rockfish ovarian cells treated with rIL-22.ResultsIn situ hybridization results showed that both il22 and il22ra1 were localized in the perinatal follicle layer and embryonic envelope. The il22 expression level was significantly increased during parturition compared to before and after parturition (PDiscussionTaken together, our results indicated that IL-22 plays an important role in the parturition of black rockfish by upregulating PG synthesis and increasing chemokine, proinflammatory factor, as well as PG synthetase levels.</p

Image_1_The anti-inflammatory cytokine IL-22 exhibited a proinflammatory effect in the ovary aiding with the parturition of ovoviviparous black rockfish (Sebastes schlegelii).tif

IntroductionAs a unique type of immunological process, pregnancy and subsequent parturition are associated with a series of inflammatory events. As an anti-inflammatory cytokine, IL-22 has been proven to participate in the parturition process in mammals. However, less is known about ovoviviparous teleosts. To investigate the role of IL-22 in fish parturition, black rockfish, an ovoviviparous teleost, was used. This fish is unique in that it provides over 60% nutrition supply for over 50 thousand embryos at the same time though a placenta-like structure during pregnancy while delivering all fries in two hours.MethodsSequence alignment, phylogenetic tree analysis and homology modeling were performed on IL-22 and its receptor. In situ hybridization demonstrated ovarian localization of il22 and il22r1. The protein of rIL-22 was obtained through the prokaryotic expression. RNA-seq analysis was performed on black rockfish ovarian cells treated with rIL-22.ResultsIn situ hybridization results showed that both il22 and il22ra1 were localized in the perinatal follicle layer and embryonic envelope. The il22 expression level was significantly increased during parturition compared to before and after parturition (PDiscussionTaken together, our results indicated that IL-22 plays an important role in the parturition of black rockfish by upregulating PG synthesis and increasing chemokine, proinflammatory factor, as well as PG synthetase levels.</p