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Acinetobacter baumannii (AB) has emerged as a major pathogen in vulnerable and severely ill patients. It remains unclear whether early mortality (EM) due to AB bacteremia is because of worse clinical characteristics of the infected patients or the virulence of the pathogen. In this study, we aimed to investigate the effect of AB virulence on EM due to bacteremia. This retrospective study included 138 patients with AB bacteremia (age: ≥ 18 years) who were admitted to a tertiary care teaching hospital in South Korea between 2015 and 2019. EM was defined as death occurring within 7 days of bacteremia onset. The AB clinical isolates obtained from the patients' blood cultures were injected into 15 Galleria mellonella larvae each, which were incubated for 5 days. Clinical isolates were classified into high- and low-virulence groups based on the number of dead larvae. Patients' clinical data were combined and subjected to multivariate Cox regression analyses to identify the risk factors for EM. In total, 48/138 (34.8%) patients died within 7 days of bacteremia onset. The Pitt bacteremia score was the only risk factor associated with EM. In conclusion, AB virulence had no independent effect on EM in patients with AB bacteremia., (© 2024. The Author(s).)

Introduction: The Global Research Collaboration for Infectious Disease Preparedness (GloPID-R) is a network of funders supporting research on infectious diseases of epidemic/pandemic potential. GloPID-R is establishing regional hubs to strengthen stakeholder engagement particularly among low-income and middle-income countries. The first pilot hub, led from Republic of Korea (South Korea), has been launched in the Asia-Pacific region, a region highly prone to outbreaks of emerging infectious diseases. We present findings of mapping research undertaken in support of the hub's development., Methods: We analysed five COVID-19 research databases in September 2022 to identify research funders and intermediary funding sources supporting research in infectious diseases in the Asia-Pacific region. This was complemented with an in-depth analysis of the UK Collaborative on Development Research (UKCDR) and GloPID-R COVID-19 Research Project Tracker to assess the alignment of funded projects in the region to the WHO COVID-19 research priorities., Results: We identified 453 funders and funding sources supporting COVID-19 research in the Asia-Pacific Region including public, private and philanthropic organisations and universities. However, these organisations were clustered in few countries in the region. The in-depth analysis of the UKCDR and GloPID-R COVID-19 Research project Tracker found limited research involving Asia-Pacific countries with the 117 funders supporting these projects investing at least US$604m in COVID-19 research in the region. Social Sciences was the dominant theme on which funded projects focused whereas the priority areas with the least number of projects were research on 'animal and environmental health' and 'ethics considerations for research'., Conclusion: Our analyses show the diversity of funding sources for research on infectious diseases in the Asia-Pacific region. Engagement between multiple actors in the health research system is likely to promote enhanced coordination for greater research impact. GloPID-R's Asia-Pacific regional hub aims to support activities for the enhancement of preparedness for outbreaks of emerging infectious diseases in the region., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2023. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Acinetobacter baumannii is a highly potent nosocomial pathogen that is associated with increased in-hospital mortality. Here, we investigated the changes in molecular characteristics of carbapenem-resistant A. baumannii (CRAB) isolated from the blood samples of patients admitted to a tertiary hospital in South Korea from January 2009 to July 2015. Whole genome sequencing using the Illumina MiSeq platform and multi-locus sequence typing (MLST) were performed for 98 CRAB clinical isolates. In silico analyses for the prediction of antimicrobial resistance and virulence factor genes were performed. Plasmid sequences, including complete forms, were reconstructed from the sequence reads. Epidemiologic data were collected from the hospital database. MLST using the Oxford scheme revealed 10 sequence types of CRAB, of which ST191 was the dominant type (n = 59). Although blaOXA-23 was shared by most analysed strains, the compositions of antimicrobial resistance determinants differed among sequence types. ST447 and ST451/ST1809 with a few resistance genes were isolated during the later years of the study period. The number of virulence genes increased, while that of ST191 did not change significantly over the investigation period. Intriguingly MLST types, compositions of antimicrobial resistance genes, and virulence genes had no association with clinical outcomes of CRAB bacteraemia. In conclusion, active changes in or accumulations of antimicrobial resistance determinants and virulence genes in CRAB were not observed during the research period. Molecular characteristics of CRAB had no association with clinical outcomes of CRAB bacteraemia., Competing Interests: The authors have declared that no competing interests exist.

Yeast associates with many plant parts including the phyllosphere, where it is subject to harsh environmental conditions. Few studies have reported on biological control of foliar pathogens by yeast. Here, we newly isolated leaf-colonizing yeasts from leaves of field-grown pepper plants in a major pepper production area of South Korea. The yeast was isolated using semi-selective medium supplemented with rifampicin to inhibit bacterial growth and its disease control capacity against Xanthomonas axonopodis infection of pepper plants in the greenhouse was evaluated. Of 838 isolated yeasts, foliar spray of Pseudozyma churashimaensis strain RGJ1 at 10 8  cfu/mL conferred significant protection against X. axonopodis and unexpectedly against Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus, and Broad bean wilt virus under field conditions. Direct antagonism between strain RGJ1 and X. axonopodis was not detected from co-culture assays, suggesting that disease is suppressed via induced resistance. Additional molecular analysis of the induced resistance marker genes Capsicum annuum Pathogenesis-Related (CaPR) 4 and CaPR5 indicated that strain RGJ1 elicited plant defense priming. To our knowledge, this study is the first report of plant protection against bacterial and viral pathogens mediated by a leaf-colonizing yeast and has potential for effective disease management in the field.

Plants have developed general and specific defense mechanisms for protection against various enemies. Among the general defenses, induced resistance has distinct characteristics, such as broad-spectrum resistance and long-lasting effectiveness. This study evaluated over 500 specific chemical compounds derived from native Korean plant species to determine whether they triggered induced resistance against Pectobacterium carotovorum supsp. carotovorum (Pcc) in tobacco (Nicotiana tabacum) and Pseudomonas syringae pv. tomato (Pst) in Arabidopsis thaliana. To select target compound(s) with direct and indirect (volatile) effects, a new Petri-dish-based in vitro disease assay system with four compartments was developed. The screening assay showed that capsaicin, fisetin hydrate, jaceosidin, and farnesiferol A reduced the disease severity significantly in tobacco. Of these four compounds, capsaicin and jaceosidin induced resistance against Pcc and Pst, which depended on both salicylic acid (SA) and jasmonic acid (JA) signaling, using Arabidopsis transgenic and mutant lines, including npr1 and NahG for SA signaling and jar1 for JA signaling. The upregulation of the PR2 and PDF1.2 genes after Pst challenge with capsaicin pre-treatment indicated that SA and JA signaling were primed. These results demonstrate that capsaicin and jaceosidin can be effective triggers of strong induced resistance against both necrotrophic and biotrophic plant pathogens.

The yellow-pigmented, Gram-stain-negative, rod-shaped bacterium KJ1R5(T) was isolated from the root of a pepper plant grown in a field in Kwangju, Korea. Strain KJ1R5(T) was characterized by physiological, biochemical, and molecular genetic analyses. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain KJ1R5(T) was most closely related to members of the genus Chryseobacterium, and that the strain exhibited the highest similarities with type strains of Chryseobacterium vrystaatense (97.0 %) and Chryseobacterium rhizosphaerae (97.1 %). DNA-DNA hybridization reassociation values between strain KJ1R5(T) and type strains of C. vrystaatense KACC 11675(T) and C. rhizosphaerae KACC 14918(T) were 46.9 and 38.4 %, respectively. The DNA G+C content of KJ1R5(T) is 40.2 mol%. The predominant respiratory quinone of KJ1R5(T) was menaquinone MK-6; major cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 1ω9c, and iso-C17 : 0 3-OH. On the basis of these phenotypic and genotypic characteristics, the strain significantly differed from representative strains belonging to the genus Chryseobacterium. Thus, we propose that strain KJ1R5(T) represents a novel species of the genus Chryseobacterium, named Chryseobacterium kwangjuense sp. nov. The type strain is KJ1R5(T) (= KACC 13029(T) = JCM 15904(T)).

Plant growth promoting rhizobacteria Ochrobactrum lupini KUDC1013 and Novosphingobium pentaromativorans KUDC1065 isolated from Dokdo Island, S. Korea are capable of eliciting induced systemic resistance (ISR) in pepper against bacterial spot disease. The present study aimed to determine whether plant growth-promoting rhizobacteria (PGPR) strains including strain KUDC1013, strain KUDC1065, and Paenibacillus polymyxa E681 either singly or in combinations were evaluated to have the capacity for potential biological control and plant growth promotion effect in the field trials. Under greenhouse conditions, the induced systemic resistance (ISR) effect of treatment with strains KUDC1013 and KUDC1065 differed according to pepper growth stages. Drenching of 3-week-old pepper seedlings with the KUDC-1013 strain significantly reduced the disease symptoms. In contrast, treatment with the KUDC1065 strain significantly protected 5-week-old pepper seedlings. Under field conditions, peppers treated with PGPR mixtures containing E681 and KUDC1013, either in a two-way combination, were showed greater effect on plant growth than those treated with an individual treatment. Collectively, the application of mixtures of PGPR strains on pepper might be considered as a potential biological control under greenhouse and field conditions.

Paenibacillus polymyxa E681, a spore-forming, low-G+C, Gram-positive bacterium isolated from the rhizosphere of winter barley grown in South Korea, has great potential for agricultural applications due to its ability to promote plant growth and suppress plant diseases. Here we present the complete genome sequence of P. polymyxa E681. Its 5.4-Mb genome encodes functions specialized to the plant-associated lifestyle and characteristics that are beneficial to plants, such as the production of a plant growth hormone, antibiotics, and hydrolytic enzymes.

A Gram-negative, non-motile, pale-yellow, rod-shaped bacterial strain, DS-42(T), was isolated from a soil in Korea and its taxonomic position was investigated by a polyphasic study. Strain DS-42(T) grew optimally at 25 degrees C and pH 7.0-8.0. Strain DS-42(T) did not form nodules on three different legumes, and the nodD and nifH genes were also not detected by PCR. Strain DS-42(T) contained Q-10 as the predominant ubiquinone. The major cellular fatty acid was C(18 : 1)omega7c. The DNA G+C content was 60.8 mol%. Phylogenetic analyses based on 16S rRNA, atpD and recA gene sequences showed that strain DS-42(T) belonged to the genus Rhizobium. Strain DS-42(T) showed 16S rRNA gene sequence similarity of 94.1-97.7 % to the type strains of recognized Rhizobium species. DNA-DNA relatedness between strain DS-42(T) and the type strains of Rhizobium huautlense, R. galegae, R. loessense and R. cellulosilyticum was 13-19 %, indicating that strain DS-42(T) was distinct from them genetically. Strain DS-42(T) can also be differentiated from these four phylogenetically related Rhizobium species by various phenotypic properties. On the basis of phenotypic properties, phylogenetic distinctiveness and genetic data, strain DS-42(T) is considered to represent a novel species of the genus Rhizobium, for which the name Rhizobium soli sp. nov. is proposed. The type strain is DS-42(T) (=KCTC 12873(T) =JCM 14591(T)).