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Bacterial polysaccharide is advantageous over plant, algal, and fungal polysaccharides in terms of stability, non-toxicity, and biodegradable nature. In addition, bacterial cell wall polysaccharide (CPs) is very little explored compared to exopolysaccharide. In this study, CPs have been isolated from thermotolerant Chryseobacterium geocarposphaerae DD3 (CPs3) from textile industry dye effluent. Structural characterization of the CPs was done by different techniques, viz., scanning electron microscopy-energy dispersive X-ray spectrometry (SEM–EDX), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and thermogravimetric analysis (TGA). CPs3 demonstrated compact non-porous amorphous surface composed of evenly distributed macromolecular lumps. TGA revealed a high thermostability (~ 350 °C) of the polysaccharide. FTIR and NMR confirm the polysaccharidic nature of the polymer, consisting of glucose units linked by both β-(1 → 3) and β-(1 → 4) glycosidic bonds. The functional properties of CPs3 were evaluated for industrial use as additive, especially antibacterial, emulsification, and flocculation capacities. A single-step green synthesis of silver nanoparticle (AgNP) was performed using CPs3. AgNP was characterized using ultraviolet–visible (UV–Vis) spectroscopy, transmission electron microscopy (TEM), AFM, and particle size analyses. The CPs3-stabilized AgNP exhibited potential photocatalytic activity against a broad range of azo dyes, congo red (88.33 ± 0.48%), methyl red (76.81 ± 1.03%), and malachite green (47.34 ± 0.90%) after only 3 h of reaction. According to our knowledge, this is the first report on CPs from C. geocarposphaerae. The results demonstrated multifunctionality of CPs3 in both prospective, CPs3 as additive in biotechnology industry as well as Cps3-stabilized AgNP for bioremediation of azo dye. [ABSTRACT FROM AUTHOR]

Chryseobacterium demonstrates a diverse environmental presence and a significant pathogenic potential across various ecosystems. This clinical case showcases a rare instance of bacterial infection in a 75-year-old male with untreated diabetes and recurrent urinary tract infections (UTIs). The patient presented symptoms of abdominal pain, burning urination, fever, and an elevated eosinophil count. A subsequent urine culture identified a Chryseobacterium-related bacterium as the causative agent, exhibiting sensitivity to piperacillin/tazobactam, trimethoprim/sulfamethoxazole, and nitrofurantoin, which led to successful treatment using oral nitrofurantoin. Analysis of the 16S rRNA gene sequence of APV-1T revealed a close relationship of 98.2% similarity to Chryseobacterium gambrini strain 5-1St1aT (AM232810). Furthermore, comparative genome analysis, incorporating Average Nucleotide Identity (ANI), Digital DNA–DNA Hybridization (dDDH) values, and comprehensive phylogenetic assessments utilizing 16S rRNA gene sequences, core genes, and amino acid sequences of core proteins, highlighted the unique phylogenetic positioning of APV-1T within the Chryseobacterium genus. Distinct carbon utilization and assimilation patterns, along with major fatty acid content, set APV-1T apart from C. gambrini strain 5-1St1aT. These findings, encompassing phenotypic, genotypic, and chemotaxonomic characteristics, strongly support the proposal of a novel species named Chryseobacterium urinae sp. nov., with APV-1T designated as the type strain (= MCC 50690 = JCM 36476). Despite its successful treatment, the strain displayed resistance to multiple antibiotics. Genomic analysis further unveiled core-conserved genes, strain-specific clusters, and genes associated with antibiotic resistance and virulence. This report underscores the vital importance of elucidating susceptibility patterns of rare pathogens like Chryseobacterium, particularly in immunocompromised individuals. It advocates for further analyses to understand the functional significance of identified genes and their implications in treatment and pathogenesis. [ABSTRACT FROM AUTHOR]

Flavobacterial diseases, caused by bacteria in the order Flavobacteriales, are responsible for devastating losses in farmed and wild fish populations worldwide. The genera Flavobacterium (Family Flavobacteriaceae) and Chryseobacterium (Weeksellaceae) encompass the most well-known agents of fish disease in the order, but the full extent of piscine-pathogenic species within these diverse groups is unresolved, and likely underappreciated. To identify emerging agents of flavobacterial disease in US aquaculture, 183 presumptive Flavobacterium and Chryseobacterium isolates were collected from clinically affected fish representing 19 host types, from across six western states. Isolates were characterized by 16S rRNA gene sequencing and phylogenetic analysis using the gyrB gene. Antimicrobial susceptibility profiles were compared between representatives from each major phylogenetic clade. Of the isolates, 52 were identified as Chryseobacterium species and 131 as Flavobacterium. The majority of Chryseobacterium isolates fell into six clades (A-F) consisting of ≥ 5 fish isolates with ≥ 70% bootstrap support, and Flavobacterium into nine (A-I). Phylogenetic clades showed distinct patterns in antimicrobial susceptibility. Two Chryseobacterium clades (F & G), and four Flavobacterium clades (B, G-I) had comparably high minimal inhibitory concentrations (MICs) for 11/18 antimicrobials tested. Multiple clades in both genera exhibited MICs surpassing the established F. psychrophilum breakpoints for oxytetracycline and florfenicol, indicating potential resistance to two of the three antimicrobials approved for use in finfish aquaculture. Further work to investigate the virulence and antigenic diversity of these genetic groups will improve our understanding of flavobacterial disease, with applications for treatment and vaccination strategies.

ABSTRACT: Objectives: The dissemination of antibiotic resistance genes (ARGs) from the environment, including agricultural sources, is of increasing concern. In this study, we examined the antibiotic resistance profile and genomic sequence of a strain of Chryseobacterium indoltheticum obtained from an agricultural location. Methods: The multidrug-resistant bacterial strain POL15 was isolated from the wastewater of a livestock farm in China. Whole-genome sequencing was performed followed by bioinformatics analyses to identify integrative and conjugative elements (ICEs) and ARGs. Mating assays were performed to analyse ICE transferability. Results: Whole-genome sequencing and annotation showed that the genome of POL15 encodes ARGs. Additionally, an ICE named ICECiPOL15, which carries a class C β-lactamase-encoding gene blaAQU, was identified in the POL15 genome. Genes encoding an integrase, an excisionase, a relaxase, a type IV coupling protein and conjugative transposon proteins involved in a type IV secretion system were also identified in ICECiPOL15. Sequence alignment revealed that ICECiPOL15 might have evolved from other Chryseobacterium species. The horizontal transferability of ICECiPOL15 was demonstrated by mating experiments between C. indoltheticum POL15 and Escherichia coli DL21. Conclusions: This study represents the first characterization of a mobilizable antibiotic resistance ICE in a species of C. indoltheticum and provides evidence that C. indoltheticum strains could be important reservoirs and vehicles for ARGs on livestock farms.

O gênero Chryseobacterium é composto por bacilos aeróbicos gram-negativos que sobrevivem à cloração da água. Estes microrganismos são produtores de biofilme e proteases, como Beta-lactamases classe A e classe B, que os tornam resistentes a penicilinas, aminoglicosídeos, carbapenêmicos e as primeiras gerações de cefalosporinas. O relato do caso envolve uma paciente do sexo feminino, 3 meses de idade, prematura de 34 semanas, baixo peso, APGAR 8/9, que apresenta má formação congênita com mielomeningocele e hidrocefalia. Houve necessidade de correção e colocação de Derivação Ventrículo-Peritoneal (DVP) na semana seguinte ao nascimento, com quadro de enterocolite associada. Houve necessidade de ressecção de íleo distal, colón ascendente e terço proximal do colón transverso. Paciente recebe alta após término de tratamento, mas é internada novamente depois de cinco dias por apresentar perda liquórica pelo orifício de DVP, com abaulamento da região lombar, líquor turvo, sinais de desidratação, tempo de enchimento capilar aumentado, descoramento, hipoatividade, dor abdominal e vômitos; após a retirada de DVP a hidrocefalia e meningite associada se mantiveram. Foi administrado dose dobrada de meropenem associada com vancomicina de forma empírica para cobertura de sistema nervoso central em ciclo de um mês, mas paciente manteve quadro clínico febril e liquor permaneceu turvo. Na cultura bacteriana foi isolado Chryseobacterium indologens com perfil de resistência à cefalosporinas de terceira geração, piperacilina tazobactam, carbapenêmicos, aminoglicosídeos e a sulfametoxazol trimetoprim e com perfil de sensibilidade às quinolonas, a ceftazidima e ao cefepime. Devido foco em sistema nervoso central foi instituído tratamento com cefepime em dose dobrada e tempo de infusão prolongado por seis semanas. Após o tratamento, o liquor de controle evidenciou queda de lactato e ausência de crescimento bacteriano associado. Paciente teve alta hospitalar depois da recolocação do DVP e se mostrar clinicamente estável e afebril. As infecções por esse agente associadas a dispositivos de assistência vêm apresentando um aumento nos últimos anos. Seu potencial patogênico é elevado e pode possuir alta mortalidade dependendo do foco acometido, uma vez que seu perfil de resistência dificulta o tratamento e induz a falha terapêutica em muitos dos esquemas habituais empíricos quando se tratando de infecções hospitalares.

Objective: To investigate the clinical and epidemiological features and outcome of Chryseobacterium and Elizabethkingia spp. infections in children, together with antimicrobial susceptibilities. Methods: This retrospective study was conducted at a tertiary pediatric hospital in Turkey. All patients infected with Chryseobacterium/Elizabethkingia spp. among those presenting to Ankara City Hospital between March 2014 and March 2022 were included. Results: A total of 49 cases were included and 29 cases were identified as Elizabethkingia. The median age was 14 (0.2-185.0) months. The majority (89.8%) of these patients had an underlying disease, including malignancy (42.9%). Bacteremia (46.9%) and central line-associated bloodstream infection (28.6%) were the most common infections. The thirty-day all-cause mortality rate was 12.2%. The most commonly used antibiotics were ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX). Forty-five (91.8%) isolates were susceptible to ciprofloxacin, 44 (91.6%) to TMP-SMX, and 21 (87.5%) to levofloxacin. Conclusions: Chryseobacterium and Elizabethkingia spp. are emergent, nosocomial pathogens and the majority of cases were older than the neonatal period. They were mainly seen in patients with long hospital stays, indwelling devices, and those who have received antibiotics within the last month, especially carbapenems. In addition, they were associated with bloodstream infection and malignancy. The most commonly useful antibiotics according to the resistance patterns were ciprofloxacin and TMP-SMX.

Objective: To investigate the clinical and epidemiological features and outcome of Chryseobacterium and Elizabethkingia spp. infections in children, together with antimicrobial susceptibilities. Methods: This retrospective study was conducted at a tertiary pediatric hospital in Turkey. All patients infected with Chryseobacterium/Elizabethkingia spp. among those presenting to Ankara City Hospital between March 2014 and March 2022 were included. Results: A total of 49 cases were included and 29 cases were identified as Elizabethkingia. The median age was 14 (0.2-185.0) months. The majority (89.8%) of these patients had an underlying disease, including malignancy (42.9%). Bacteremia (46.9%) and central line-associated bloodstream infection (28.6%) were the most common infections. The thirty-day all-cause mortality rate was 12.2%. The most commonly used antibiotics were ciprofloxacin and trimethoprim-sulfamethoxazole (TMP-SMX). Forty-five (91.8%) isolates were susceptible to ciprofloxacin, 44 (91.6%) to TMPSMX, and 21 (87.5%) to levofloxacin. Conclusions: Chryseobacterium and Elizabethkingia spp. are emergent, nosocomial pathogens and the majority of cases were older than the neonatal period. They were mainly seen in patients with long hospital stays, indwelling devices, and those who have received antibiotics within the last month, especially carbapenems. In addition, they were associated with bloodstream infection and malignancy. The most commonly useful antibiotics according to the resistance patterns were ciprofloxacin and TMP-SMX. [ABSTRACT FROM AUTHOR]

The respiratory tract of lung transplant recipients (LTR) is likely to be colonized with non-fermentative Gram-negative rods. As a consequence of the improvements in molecular sequencing and taxonomy, an increasing number of bacterial species have been described. We performed a review of the literature of bacterial infections in LTR involving non-fermentative Gram-negative rods with exclusion of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Achromobacter spp. and Burkholderia spp. Overall, non-fermenting GNR were recovered from 17 LTR involving the following genera: Acetobacter, Bordetella, Chryseobacterium, Elizabethkinga, Inquilinus, and Pandoraea. We then discuss the issues raised by these bacteria, including detection and identification, antimicrobial resistance, pathogenesis, and cross-transmission. [ABSTRACT FROM AUTHOR]

Flavobacterial diseases, caused by bacteria in the order Flavobacteriales, are responsible for devastating losses in farmed and wild fish populations worldwide. The genera Flavobacterium (Family Flavobacteriaceae) and Chryseobacterium (Weeksellaceae) encompass the most well-known agents of fish disease in the order, but the full extent of piscine-pathogenic species within these diverse groups is unresolved, and likely underappreciated. To identify emerging agents of flavobacterial disease in US aquaculture, 183 presumptive Flavobacterium and Chryseobacterium isolates were collected from clinically affected fish representing 19 host types, from across six western states. Isolates were characterized by 16S rRNA gene sequencing and phylogenetic analysis using the gyrB gene. Antimicrobial susceptibility profiles were compared between representatives from each major phylogenetic clade. Of the isolates, 52 were identified as Chryseobacterium species and 131 as Flavobacterium. The majority of Chryseobacterium isolates fell into six clades (A-F) consisting of ≥ 5 fish isolates with ≥ 70% bootstrap support, and Flavobacterium into nine (A-I). Phylogenetic clades showed distinct patterns in antimicrobial susceptibility. Two Chryseobacterium clades (F & G), and four Flavobacterium clades (B, G-I) had comparably high minimal inhibitory concentrations (MICs) for 11/18 antimicrobials tested. Multiple clades in both genera exhibited MICs surpassing the established F. psychrophilum breakpoints for oxytetracycline and florfenicol, indicating potential resistance to two of the three antimicrobials approved for use in finfish aquaculture. Further work to investigate the virulence and antigenic diversity of these genetic groups will improve our understanding of flavobacterial disease, with applications for treatment and vaccination strategies. [ABSTRACT FROM AUTHOR]

Here, we report the first complete genome of a psychrotolerant and yellow-pigmented rhizobacteria Chryseobacterium cucumeris PCH239. It was obtained from the rhizospheric soil of the Himalayan plant Bergenia ciliata. The genome consists of a single contig (5.098 Mb), 36.3% G + C content, and 4899 genes. The cold adaptation, stress response, and DNA repair genes promote survivability in a high-altitude environment. PCH239 grows in temperature (10–37 °C), pH (6.0–8.0), and NaCl (2.0%). The genome derived plant growth-promoting activities of siderophore production (siderophore units 53 ± 0.6), phosphate metabolism (PSI 5.0 ± 0.8), protease, indole acetic acid production (17.3 ± 0.5 µg/ml), and ammonia (2.89 ± 0.4 µmoles) were experimentally validated. Interestingly, PCH239 treatment of Arabidopsis seeds significantly enhances germination, primary, and hairy root growth. In contrast, Vigna radiata and Cicer arietinum seeds had healthy radicle and plumule elongation, suggesting varied plant growth-promotion effects. Our findings suggested the potential of PCH239 as a bio-fertilizer and biocontrol agent in the challenging conditions of cold and hilly regions. [ABSTRACT FROM AUTHOR]

Aims: The resistance rate of Chryseobacterium indologenes to commonly available antibiotics is very worrisome. As documented by SENTRY antimicrobial surveillance program, C. indologenes has different antibiotic resistance patterns. This study investigated the prevalence of C. indologenes in the hospital environment and their susceptibility pattern to commonly available antibiotics. Methodology and results: Chryseobacterium indologenes isolates were identified using DNA sequence-based identification method. Evaluation of resistant genes was done using specific primers. Fifty-two (52) isolates met the characteristics for the identification. Chryseobacterium indologenes' prevalence was 5.9%, 7.8% and 7.5% in hospitals 1, 2 and 3, respectively. The in vitro antibiotic susceptibility testing of C. indologenes isolates revealed that some isolates were multidrug-resistant. Some isolates were susceptible to levofloxacin (34.6%), ciprofloxacin (25%), ceftriaxone (19.2%) and gentamicin (13.5%). There was zero susceptibility to imipenem, cefuroxime, amikacin and ceftazidime. The 16s rRNA sequence of C. indologenes isolates showed 99.9% similarity compared with a highly similar sequence from the NCBI nucleotide database. Their evolutionary distances were in agreement with the phylogenetic placement of the 16S rDNA of the isolates, as all the isolates were revealed to be C. indologenes strain Sn6 with accession number KC683715. The resistant genes evaluation revealed that the isolates harbor SHV, TEM, QnrA, QnrS and APH (3')-IIIA genes, as indicated by amplification of those genes on agarose gel electrophoresis. Conclusion, significance and impact of study: The high prevalence of C. indologenes Sn6 and its high degree of resistance observed in this study represent a potential public health risk. [ABSTRACT FROM AUTHOR]

Two novel bacterial species CJ51T and CJ63T belonging to the genus Chryseobacterium were isolated from the Upo wetland and the Han River, South Korea, respectively. Cells of these strains were Gram-stain-negative, aerobic, non-motile, rod-shaped, and catalase- and oxidase-positive. Both strains were shown to grow optimally at 30 °C and pH 7 in the absence of NaCl on tryptic soy agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strains CJ51T and CJ63T belonged to the genus Chryseobacterium and were most closely related to Chryseobacterium piperi CTMT and Chryseobacterium piscicola VQ-6316sT with 98.47% and 98.46% 16S rRNA sequence similarities, respectively. The average nucleotide identity values of strains CJ51T and CJ63T with its closely related type strains Chryseobacterium piperi CTMT and Chryseobacterium piscicola VQ-6316sT were 81.9% and 82.1%, respectively. The major fatty acids of strains CJ51T and CJ63T were iso-C15:0, iso-C17:0 3-OH and summed feature 9 (C16:0 10-methyl and/or iso-C17:1ω9c). Menaquinone 6 (MK-6) was identified as the primary respiratory quinone in both strains. The major polar lipids of strains CJ51T and CJ63T were phosphatidylethanolamine and several unidentified amino lipids and lipids. Based on polyphasic taxonomy data, strains CJ51T and CJ63T represent novel species of the genus Chryseobacterium, for which names Chryseobacterium paludis sp. nov. and Chryseobacterium foetidum sp. nov. are proposed respectively. The type strains are CJ51T (= KACC 22749T = JCM 35632T) and CJ63T (= KACC 22750T = JCM 35633T). [ABSTRACT FROM AUTHOR]

Flavobacterial diseases, caused by bacteria in the order Flavobacteriales, are responsible for devastating losses in farmed and wild fish populations worldwide. The genera Flavobacterium (Family Flavobacteriaceae) and Chryseobacterium (Weeksellaceae) encompass the most well-known agents of fish disease in the order, but the full extent of piscine-pathogenic species within these diverse groups is unresolved, and likely underappreciated. To identify emerging agents of flavobacterial disease in US aquaculture, 183 presumptive Flavobacterium and Chryseobacterium isolates were collected from clinically affected fish representing 19 host types, from across six western states. Isolates were characterized by 16S rRNA gene sequencing and phylogenetic analysis using the gyrB gene. Antimicrobial susceptibility profiles were compared between representatives from each major phylogenetic clade. Of the isolates, 52 were identified as Chryseobacterium species and 131 as Flavobacterium. The majority of Chryseobacterium isolates fell into six clades (A-F) consisting of ≥ 5 fish isolates with ≥ 70% bootstrap support, and Flavobacterium into nine (A-I). Phylogenetic clades showed distinct patterns in antimicrobial susceptibility. Two Chryseobacterium clades (F & G), and four Flavobacterium clades (B, G-I) had comparably high minimal inhibitory concentrations (MICs) for 11/18 antimicrobials tested. Multiple clades in both genera exhibited MICs surpassing the established F. psychrophilum breakpoints for oxytetracycline and florfenicol, indicating potential resistance to two of the three antimicrobials approved for use in finfish aquaculture. Further work to investigate the virulence and antigenic diversity of these genetic groups will improve our understanding of flavobacterial disease, with applications for treatment and vaccination strategies.

The type strain SUR2 of the novel species Chryseobacterium limigenitum was isolated from a dehydrated sludge of the municipal sewage treatment plant in Dogoše near Maribor in Slovenia. The draft genome, with 60 contigs, 4,697,725bp, 34.4% of G+C content, was obtained using the Illumina HiSeq 2500-1 platform. Joint Genome Institute Microbial Genome Annotation Pipeline (MGAP v.4) has identified 4322 protein-coding sequences including resistance genes against arsenic and other heavy metals. In addition, a subclass B3 metallo-β-lactamase, which confers resistance to penicillins, cephalosporins and carbapenems, was also present in the genome. The genome sequence provides important information regarding bioremediation potential and pathogenic properties of this newly identified species.

ABSTRACT Chryseobacterium spp. are Gram-negative rods found ubiquitously in the environment, with certain species being reported as having unusual degrading properties. Polyvinyl alcohol (PVA) is used widely in industry but causes serious global environmental pollution. Here, we report the complete genome sequence of a novel bacterium, AC3, that efficiently degrades PVA. As the representative genome of Chryseobacterium nepalense, key genomic characteristics (e.g., mobile genetic elements, horizontal genes, genome-scale metabolic network, secondary metabolite biosynthesis gene clusters, and carbohydrate-active enzymes) were comprehensively investigated to reveal the potential genetic features of this species. Core genome phylogenetic analysis in combination with average nucleotide identity, average amino acid identity, and in silico DNA-DNA hybridization values provided an accurate taxonomic position of C. nepalense in the genus Chryseobacterium. Comparative genomic analysis of AC3 with closely related species suggested evolutionary dynamics characterized by a species-specific genetic repertoire, dramatic rearrangements, and evolutionary constraints driven by selective pressure, which facilitated the speciation and adaptative evolution of C. nepalense. Biogeographic characterization indicated that this species is ubiquitously distributed not only in soil habitats but also in a variety of other source niches. Bioinformatic analysis revealed the potential genetic basis of PVA degradation in AC3, which included six putative genes associated with the synthesis of PVA dehydrogenase, cytochrome c, oxidized PVA hydrolase, and secondary alcohol dehydrogenase. Our study reports the first complete genome of C. nepalense with PVA-degrading properties, providing comprehensive insights into the genomic characteristics of this species and increasing our understanding of the microbial degradation of PVA. IMPORTANCE Although PVA is a biodegradable polymer, the widespread use of PVA in global industrialization has resulted in serious environmental problems. To date, knowledge of effective and applicable PVA-degrading bacteria is limited, and thus, the discovery of novel PVA biodegraders is pertinent. Here, we isolated a novel bacterial strain, AC3, which efficiently degraded PVA. The complete genome of AC3 was sequenced as the first genome sequence of the species C. nepalense. Comparative genomic analysis was performed to comprehensively investigate the phylogenetic relationships, genome-scale metabolic network, key genomic characteristics associated with genomic evolution, evolutionary dynamics between AC3 and its close relatives, and biogeographic characterization of C. nepalense, particularly regarding the potential genetic basis of PVA degradation. These findings could advance our understanding of the genomic characteristics of C. nepalense and PVA bioremediation.

We report the isolation and identification of seven bacterial strains and one fungal strain from dead and diseased Scapteriscus borellii mole crickets collected from a golf course in southern California. Using 16S and 18S rRNA gene sequence analysis we identified the microbes as Serratia marcescens (red), S. marcescens (white), S. marcescens (purple), Achromobacter xylosoxidans, Chryseobacterium sp., Ochrobactrum anthropi, Tsukamurella tryosinosolvens, and Beauveria bassiana. We performed a dose response curve for each of these cricket-associated microbial strains (except T. tryosinosolvens) and two other strains of S. marcescens (DB1140 and ATCC 13880). We found that all of these microbes except O. anthropi were highly pathogenic to D. melanogaster compared to the other strains of S. marcescens. Injecting the mole cricket associated strains of Serratia into flies killed all infected flies in ≤24h. For all other strains, the median time to death of injected flies varied in a dose-dependent manner. In vivo growth assessments of these microbes suggested that the host immune system was quickly overcome. We used disease tolerance curves to better understand the host-microbe interactions. Further studies are necessary to understand in mechanistic detail the virulence mechanisms of these mole cricket associated microbes and how this association may have influenced the evolution of mole cricket immunity.

Significant quantities of salmon are processed daily in the industry's indoor facilities. Occupational exposure contributes to an individual's exposome. The aim of this study is to obtain knowledge about potential exposure to viable airborne species of bacteria and fungi as related to workstations in the salmon processing industry. The study was conducted in nine salmon plants along the Norwegian coast over one or two days with a one-year interval. The MAS100 was used for sampling and MALDI-TOF MS for species identification. The geometric mean concentrations of bacteria and fungi were 200 CFU/m 3 and 50 CFU/m 3 , respectively, with the highest concentrations of bacteria found in slaughtering areas and fungi in trimming of fillets. In total 125 gram-negative and 90 gram-positive bacterial and 32 different fungal species were identified. Some genera were represented by several species e.g. Chryseobacterium (15 species), Flavobacterium (13 species), Microbacterium (12 species), Pseudomonas (37 species), and Psychrobacter (13 species). Risk class 2 (RC2, human pathogens) were found in all types of workstations and plants. Seventeen bacterial species belong to RC2, some were fish pathogens, food spoilage bacteria, or species causing foodborne disease. Among fungi, Aspergillus nidulans was frequently detected across different workstations and plants. In conclusion, bacterial and fungal concentrations were low. Fish and sea-related bacteria were found along the salmon processing line. Bacterial concentrations and species compositions differ between workstations. No particular bacterial or fungal species constituted a large fraction of all airborne species. Based on the presence of human pathogens, using protective gloves is important for the workers. The presence of human and fish pathogens and food spoilage bacteria reveals air as a transmission route for bacteria, potentially affecting workers, consumers, fish, and hygiene of processing equipment. To limit the spread of these bacteria an interdisciplinary cooperation with a One Health perspective may be relevant., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Berit Bang reports financial support was provided by Research Council of Norway. Berit Bang reports financial support was provided by Helse Nord health trust. Anna B.O. Nordhammer reports financial support was provided by Haukeland University Hospital. Anne Mette Madsen reports financial support was provided by Focused Research Effort on Chemicals in the Working Environment (FFIKA- Green) form the Danish Government. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Both Klebsiella pneumoniae and Chryseobacterium cause an increasing number of diseases in fish, resulting in great economic losses in aquaculture. In addition, the disease infected with Klebsiella pneumoniae or Chryseobacterium exhibited the similar clinical symptoms in aquatic animals. However, there is no effective means for the simultaneous detection of co-infection and discrimination them for these two pathogens. Here, we developed a duplex polymerase chain reaction (PCR) method based on the outer membrane protein A ( ompA ) gene of Klebsiella pneumoniae and Chryseobacterium . The specificity and validity of the designed primers were confirmed experimentally using simplex PCR. The expected amplicons for Klebsiella pneumoniae and Chryseobacterium had a size of 663 and 1404 bp, respectively. The optimal condition for duplex PCR were determined to encompass a primer concentration of 0.5 μM and annealing temperature of 57°C. This method was analytical specific with no amplification being observed from the genomic DNA of Escherichia coli , Vibrio harveyi , Pseudomonas plecoglossicida , Aeromonas hydrophila and Acinetobacter johnsonii . The limit of detection was estimated to be 20 fg of genomic DNA for Chryseobacterium and 200 fg for Klebsiella pneumoniae , or 100 colony-forming units (CFU) of bacterial cells in both cases. The duplex PCR was capable of simultaneously amplifying target fragments from genomic DNA extracted from the bacteria and fish liver. For practical validation of the method, 20 diseased fish were collected from farms, among which 4 samples were PCR-positive for Klebsiella pneumoniae and Chryseobacterium . The duplex PCR method developed here is time-saving, specific, convenient, and may prove to be an invaluable tool for molecular detection and epidemiological investigation of Klebsiella pneumoniae and Chryseobacterium in the field of aquaculture.

Background Elizabethkingia meningoseptica, formerly known as Chryseobacterium meningosepticum, is a non-motile, non-fastidious, catalase and oxidase-positive, aerobic, glucose-non-fermentative, Gram-negative bacillus that was first defined by Elizabeth O. King in 1959. It has emerged as an opportunistic pathogen that has infected patients in extreme age groups and immunocompromised individuals, especially in intensive care settings. There has been an increased interest in this pathogen due to its increasing occurrence around the world, ubiquitous nature, and inherent capacity for antimicrobial resistance. Methods We describe an observational study at a tertiary care center in Karachi, Pakistan, based on patients admitted between January 2013 and December 2018, with E. meningoseptica infections. All patients were confirmed to have a positive clinical culture specimen for E. meningoseptica along with symptoms and signs consistent with infection. Data were collected on a structured proforma from the Hospital Information Management Systems. Results Sixteen patients with E. meningoseptica that met the criteria for infection were identified, 13 of whom required admission. Eight patients had bacteremia in addition to confirmed E. meningoseptica infection. Two of the isolates were multi-drug resistant and only sensitive to minocycline. Nine out of 13 patients that were admitted required intubation and mechanical ventilation. The median length of hospital stay was 13 days, and five out of the 13 patients died during the hospital stay. Conclusion This is the largest case series to date reporting E. meningoseptica infections and highlights the importance of this organism as an emerging nosocomial pathogen.

The respiratory tract of lung transplant recipients (LTR) is likely to be colonized with non-fermentative Gram-negative rods. As a consequence of the improvements in molecular sequencing and taxonomy, an increasing number of bacterial species have been described. We performed a review of the literature of bacterial infections in LTR involving non-fermentative Gram-negative rods with exclusion of Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Achromobacter spp. and Burkholderia spp. Overall, non-fermenting GNR were recovered from 17 LTR involving the following genera: Acetobacter, Bordetella, Chryseobacterium, Elizabethkinga, Inquilinus, and Pandoraea. We then discuss the issues raised by these bacteria, including detection and identification, antimicrobial resistance, pathogenesis, and cross-transmission.

Chryseobacterium species are isolated and taxonomically evaluated from a wide range of sources. While C. gleum and C. indologenes have been implicated in human disease, the potential pathogenicity of numerous other species have not been investigated. The aims were therefore to evaluate 37 Chryseobacterium species and Elizabethkingia meningoseptica from environmental, food, fish, water and clinical sources for production of haemolysis, growth at 37 °C, and production of virulence enzymes. The control of these strains were investigated by determination of antimicrobial and disinfectant resistance. All the species produced α- or β-haemolysis. In terms of growth at 37 °C and production of virulence enzymes, C. soldanellicola (environmental), C. oranimense (food) and C. koreense (natural mineral water) could be potential human pathogens. Chryseobacterium piscium might be pathogenic to fish. Trimethoprim could be the most effective antimicrobial for the treatment of a Chryseobacterium species infection, while the disinfectants that contain poly-dimethyl ammonium chloride or benzalkonium chloride could be regarded as the most effective for decontamination of surfaces contaminated with Chryseobacterium species. [ABSTRACT FROM AUTHOR]

Doxycycline (DOX) represents a second-generation tetracycline antibiotic that persists as a challenging-to-degrade contaminant in environmental compartments. Despite its ubiquity, scant literature exists on bacteria proficient in DOX degradation. This study marked a substantial advancement in this field by isolating Chryseobacterium sp. WX1 from an activated sludge enrichment culture, showcasing its unprecedented ability to completely degrade 50 mg/L of DOX within 44 h. Throughout the degradation process, seven biotransformation products were identified, revealing a complex pathway that began with the hydroxylation of DOX, followed by a series of transformations. Employing an integrated multi-omics approach alongside in vitro heterologous expression assays, our study distinctly identified the tetX gene as a critical facilitator of DOX hydroxylation. Proteomic analyses further pinpointed the enzymes postulated to mediate the downstream modifications of DOX hydroxylation derivatives. The elucidated degradation pathway encompassed several key biological processes, such as the microbial transmembrane transport of DOX and its intermediates, the orchestration of enzyme synthesis for transformation, energy metabolism, and other gene-regulated biological directives. This study provides the first insight into the adaptive biotransformation strategies of Chryseobacterium under DOX-induced stress, highlighting the potential applications of this strain to augment DOX removal in wastewater treatment systems containing high concentrations of DOX. [Display omitted] • A potent DOX-degrading bacterium Chryseobacterium sp. WX1 was isolated. • Transformation products lose antibacterial efficacy against Gram-positive bacteria. • Multi-omic was applied to profile the mechanism of DOX biodegradation. • The hydroxylation of DOX was driven by the tetX gene. [ABSTRACT FROM AUTHOR]

Strain C was isolated from chicken manure, and its phenotypic characteristics were gram-stain negative, yellow-pigmented, aerobic bacterium, heterotrophic, non-motile, chemoorganotrophic, non-gliding as well as non-spore-forming. A 16S rRNA gene sequence analysis showed that strain C occupied a distinct lineage within the family of the genus Chryseobacterium, and it shared highest sequence similarity with Chryseobacterium solincola strain 1YB-R12 (80%). The new isolate has been studied for removing ammonium-nitrogen (NH4-N) and the optimization of suitable conditions. The strain C was able to degrade over 42.8% of NH4-N during its active growth cycle. Experimental study of the effect of temperature and pH on NH4-N removal showed that the temperature and pH optima for NH4-N removal were 30–35℃ and 4–8, respectively. The results indicated that strain C shows a potential application for wastewater treatment.

ABSTRACT Antibiotic resistance genes (ARGs) and horizontal transfer of ARGs among bacterial species in the environment can have serious clinical implications as such transfers can lead to disease outbreaks from multidrug-resistant (MDR) bacteria. Infections due to antibiotic-resistant Chryseobacterium and Elizabethkingia in intensive care units have been increasing in recent years. In this study, the multi-antibiotic-resistant strain Chryseobacterium sp. POL2 was isolated from the wastewater of a livestock farm. Whole-genome sequencing and annotation revealed that the POL2 genome encodes dozens of ARGs. The integrative and conjugative element (ICE) ICECspPOL2, which encodes ARGs associated with four types of antibiotics, including carbapenem, was identified in the POL2 genome, and phylogenetic affiliation analysis suggested that ICECspPOL2 evolved from related ICEEas of Elizabethkingia spp. Conjugation assays verified that ICECspPOL2 can horizontally transfer to Elizabethkingia species, suggesting that ICECspPOL2 contributes to the dissemination of multiple ARGs among Chryseobacterium spp. and Elizabethkingia spp. Because Elizabethkingia spp. is associated with clinically significant infections and high mortality, there would be challenges to clinical treatment if these bacteria acquire ICECspPOL2 with its multiple ARGs, especially the carbapenem resistance gene. Therefore, the results of this study support the need for monitoring the dissemination of this type of ICE in Chryseobacterium and Elizabethkingia strains to prevent further outbreaks of MDR bacteria. IMPORTANCE Infections with multiple antibiotic-resistant Chryseobacterium and Elizabethkingia in intensive care units have been increasing in recent years. In this study, the mobile integrative and conjugative element ICECspPOL2, which was associated with the transmission of a carbapenem resistance gene, was identified in the genome of the multi-antibiotic-resistant strain Chryseobacterium sp. POL2. ICECspPOL2 is closely related to the ICEEas from Elizabethkingia species, and ICECspPOL2 can horizontally transfer to Elizabethkingia species with the tRNA-Glu-TTC gene as the insertion site. Because Elizabethkingia species are associated with clinically significant infections and high mortality, the ability of ICECspPOL2 to transfer carbapenem resistance from environmental strains of Chryseobacterium to Elizabethkingia is of clinical concern.

Chryseobacterium sp. MHB01, Rhodococcus qingshengii MHB02, and Agrobacterium tumefaciens MHB03 were isolated from superabsorbent polymer granules cultured with an arbuscular mycorrhizal fungus. Whole-genome sequencing of these three strains revealed genome sizes of 4.57 Mb, 7.13 Mb, and 5.49 Mb with G + C contents of 36.9%, 62.5%, and 58.2%, respectively., Competing Interests: The authors declare no conflict of interest.

In this study, a bacterial strain Chryseobacterium bernardetii WK-3 was isolated from the rhizosphere soil of a uranium tailings in Southern China. It can efficiently adsorb hexavalent uranium with an adsorption ratio of 92.3%. The influence of different environmental conditions on the adsorption ratio of Chryseobacterium bernardetii strain WK-3 was investigated, and the adsorption mechanism was preliminarily discussed by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS). The results showed that the optimal adsorption conditions for U(VI) by Chryseobacterium bernardetii strain WK-3 were pH = 5, temperature 30 ℃, NaCl concentration 1%, and inoculation volume 10%. When the initial concentration of U was 50 ~ 150 mg/L, the adsorption capacity of Chryseobacterium bernardetii strain WK-3 to U(VI) reached the maximum and maintained the equilibrium at 44 h. SEM-EDS results showed that phosphorus in cells participates in the interaction of uranyl ions, which may indicate that phosphate was produced during cell metabolism and was further combined to form U(VI)-phosphate minerals. In summary, Chryseobacterium bernardetii strain WK-3 would be a promising alternative for environmental uranium contamination remediation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

A polyphasic taxonomic study was carried out on strain ES2 T , isolated from sediment of a wetland created to remediate acid drainage from a coal mine. The rod-shaped bacterium formed yellow/orange pigmented colonies and produced the pigment flexirubin. The 16S rRNA gene sequence results assigned the strain to Chryseobacterium , with 98.9 and 98.3 % similarity to Chryseobacterium vietnamense and Chryseobacterium cucumeris , respectively. Computation of the average nucleotide identity and digital DNA-DNA hybridization values with the closest phylogenetic neighbours of ES2 T revealed genetic differences at the species level, which were further substantiated by differences in several physiological characteristics. The dominant fatty acids of strain ES2 T were iso-C 15 : 0 , iso-C 17 : 1 ω9 c , iso C 17 : 0 3-OH, and iso-C 15 : 0 2-OH. The DNA G+C content was 35.5 mol%. The major polar lipid was phosphatidylethanolamine while menaquinone-6 was the only menaquinone found. This bacterium has been previously shown to possess metallophore activity towards rare earth elements, and based on genome sequencing, possesses all required genes for siderophore production/activity, possibly identifying the source of this unique ability. On the basis of the results obtained here, this bacterium is assigned to the genus Chryseobacterium as representing a new species with the name Chryseobacterium metallicongregator sp. nov., type strain ES2 T (=NRRL B-65679 T =KCTC 102120 T ).

Strain Ran72 T , a novel Gram-stain-negative, obligately aerobic, non-motile, and rod-shaped bacterium, was isolated from the faeces of the rhinoceros species Ceratotherium simum . The novel bacterial strain grew optimally in Reasoner's 2A medium under the following conditions: 0 % (w/v) NaCl, pH 7.5, and 30 °C. Based on phylogenetic analysis using 16S rRNA gene sequencing, strain Ran72 T was found to be most closely related to Chryseobacterium faecale F4 T (98.4 %), Kaistella soli DKR-2 T (98.0 %), and Kaistella haifensis H38 T (97.4 %). A comprehensive genome-level comparison between strain Ran72 T with C. faecale F4 T , K. soli DKR-2 T , and K. haifensis H38 T revealed average nucleotide identity, digital DNA-DNA hybridization, and average amino acid identity values of ≤74.9, ≤19.3, and ≤78.7 %, respectively. The major fatty acids were anteiso-C 15 : 0 (22.3 %), with MK-6 being the predominant respiratory quinone. The major polar lipids of strain Ran72 T were phosphatidylethanolamine, four unidentified aminolipids, and two unidentified lipids. Based on our chemotaxonomic, genotypic, and phenotype characterizations, strain Ran72 T was identified as representing a novel species in the genus Kaistella , for which the name Kaistella rhinocerotis sp. nov. is proposed, with the type strain Ran72 T (=KACC 23136 T =JCM 36038 T ). Based on the outcomes of our phylogenomic study, Chryseobacterium faecale should be reclassified under the genus Kaistella as Kaistella faecalis comb. nov.

Background: Elizabethkingia meningoseptica, formerly known as Chryseobacterium meningosepticum, is a non-motile, non-fastidious, catalase and oxidase-positive, aerobic, glucosenon-fermentative, Gram-negative bacillus that was first defined by Elizabeth O. King in 1959. It has emerged as an opportunistic pathogen that has infected patients in extreme age groups and immunocompromised individuals, especially in intensive care settings. There has been an increased interest in this pathogen due to its increasing occurrence around the world, ubiquitous nature, and inherent capacity for antimicrobial resistance. Methods: We describe an observational study at a tertiary care center in Karachi, Pakistan, based on patients admitted between January 2013 and December 2018, with E. meningoseptica infections. All patients were confirmed to have a positive clinical culture specimen for E. meningoseptica along with symptoms and signs consistent with infection. Data were collected on a structured proforma from the Hospital Information Management Systems. Results: Sixteen patients with E. meningoseptica that met the criteria for infection were identified, 13 of whom required admission. Eight patients had bacteremia in addition to confirmed E. meningoseptica infection. Two of the isolates were multi-drug resistant and only sensitive to minocycline. Nine out of 13 patients that were admitted required intubation and mechanical ventilation. The median length of hospital stay was 13 days, and five out of the 13 patients died during the hospital stay. Conclusions: This is the largest case series to date reporting E. meningoseptica infections and highlights the importance of this organism as an emerging nosocomial pathogen. [ABSTRACT FROM AUTHOR]

Uranium (U) contamination is hazardous to human health and the environment owing to its radiotoxicity and chemical toxicity and needs immediate attention. In this study, the immobilized biomass of Chryseobacterium sp. strain PMSZPI isolated from U enriched site, was investigated for U(VI) biomineralization in batch and column set-up. Under batch mode, the fresh or lyophilized cells successfully entrapped in calcium alginate beads demonstrated effectual U precipitation under acid and alkaline conditions. The maximum removal was detected at pH 7 wherein ∼98–99% of uranium was precipitated from 1 mM uranyl carbonate solution loading ∼350 mg U/g of biomass within 24 h in the presence of organic phosphate substrate. The resulting uranyl phosphate precipitates within immobilized biomass loaded beads were observed by SEM-EDX and TEM while the formation of U biomineral was confirmed by FTIR and XRD. Retention of phosphatase activity without any loss of uranium precipitation ability was observed for alginate beads with lyophilized biomass stored for 90 d at 4 °C. Continuous flow through experiment with PMSZPI biomass immobilized in polyacrylamide gel exhibited U loading of 0.8 g U/g of biomass at pH 7 using 1 l of 1 mM uranyl solution. This investigation established the feasibility for the application of immobilized PMSZPI biomass for field studies. Uranium contamination is currently a serious environmental concern owing to anthropogenic activities and needs immediate attention. We have developed here a biotechnological method for successful uranium removal using immobilized cells of a uranium tolerant environmental bacterium, Chryseobacterium sp. strain PMSZPI isolated from U ore deposit via phosphatase enzyme mediated uranium precipitation. The ability of immobilized PMSZPI cells to precipitate U(VI) as long-term stable U phosphates under environmental conditions relevant for contaminated waters containing high concentrations of U that exerts toxicity for biological systems is explored here. The long term stability of the immobilized biomass without compromising its U removal capacity shows the relevance of the bioremediation strategy for uranium contamination proposed in this work. [Display omitted] • Biomass of U tolerant Chryseobacterium PMSZPI was successfully immobilized. • Calcium alginate beads loaded with biomass showed efficient uranium precipitation. • Stable uranyl phosphate mineral after U precipitation was entrapped in the beads. • No compromise in U precipitation with biomass loaded beads stored for 90 d. • Biomass immobilized in polyacrylamide gel in the column demonstrated high U loading. [ABSTRACT FROM AUTHOR]

Abstract Background Nematodes represent important pathogens of humans and farmed animals and cause significant health and economic impacts. The control of nematodes is primarily carried out by applying a limited number of anthelmintic compounds, for which there is now widespread resistance being reported. There is a current unmet need to develop novel control measures including the identification and characterisation of natural pathogens of nematodes. Results Nematode killing bacilli were isolated from a rotten fruit in association with wild free-living nematodes. These bacteria belong to the Chryseobacterium genus (golden bacteria) and represent a new species named Chryseobacterium nematophagum. These bacilli are oxidase-positive, flexirubin-pigmented, gram-negative rods that exhibit gelatinase activity. Caenorhabditis elegans are attracted to and eat these bacteria. Within 3 h of ingestion, however, the bacilli have degraded the anterior pharyngeal chitinous lining and entered the body cavity, ultimately killing the host. Within 24 h, the internal contents of the worms are digested followed by the final digestion of the remaining cuticle over a 2–3-day period. These bacteria will also infect and kill bacterivorous free-living (L1-L3) stages of all tested parasitic nematodes including the important veterinary Trichostrongylids such as Haemonchus contortus and Ostertagia ostertagi. The bacteria exhibit potent collagen-digesting properties, and genome sequencing has identified novel metalloprotease, collagenase and chitinase enzymes representing potential virulence factors. Conclusions Chryseobacterium nematophagum is a newly discovered pathogen of nematodes that rapidly kills environmental stages of a wide range of key nematode parasites. These bacilli exhibit a unique invasion process, entering the body via the anterior pharynx through the specific degradation of extracellular matrices. This bacterial pathogen represents a prospective biological control agent for important nematode parasites.

Chryseobacterium species are isolated and taxonomically evaluated from a wide range of sources. While C. gleum and C. indologenes have been implicated in human disease, the potential pathogenicity of numerous other species have not been investigated. The aims were therefore to evaluate 37 Chryseobacterium species and Elizabethkingia meningoseptica from environmental, food, fish, water and clinical sources for production of haemolysis, growth at 37 °C, and production of virulence enzymes. The control of these strains were investigated by determination of antimicrobial and disinfectant resistance. All the species produced α- or β-haemolysis. In terms of growth at 37 °C and production of virulence enzymes, C. soldanellicola (environmental), C. oranimense (food) and C. koreense (natural mineral water) could be potential human pathogens. Chryseobacterium piscium might be pathogenic to fish. Trimethoprim could be the most effective antimicrobial for the treatment of a Chryseobacterium species infection, while the disinfectants that contain poly-dimethyl ammonium chloride or benzalkonium chloride could be regarded as the most effective for decontamination of surfaces contaminated with Chryseobacterium species.

ABSTRACT The cholesterol-dependent cytolysins (CDCs) are bacterial, β-barrel, pore-forming toxins. A central enigma of the pore-forming mechanism is how completion of the prepore is sensed to initiate its conversion to the pore. We identified a motif that is conserved between the CDCs and a diverse family of nearly 300 uncharacterized proteins present in over 220 species that span at least 10 bacterial and 2 eukaryotic phyla. Except for this motif, these proteins exhibit little similarity to the CDCs at the primary structure level. Studies herein show this motif is a critical component of the sensor that initiates the prepore-to-pore transition in the CDCs. We further show by crystallography, single particle analysis, and biochemical studies of one of these CDC-like (CDCL) proteins from Elizabethkingia anophelis, a commensal of the malarial mosquito midgut, that a high degree of structural similarity exists between the CDC and CDCL monomer structures and both form large oligomeric pore complexes. Furthermore, the conserved motif in the E. anophelis CDCL crystal structure occupies a nearly identical position and makes similar contacts to those observed in the structure of the archetype CDC, perfringolysin O (PFO). This suggests a common function in the CDCs and CDCLs and may explain why only this motif is conserved in the CDCLs. Hence, these studies identify a critical component of the sensor involved in initiating the prepore-to-pore transition in the CDCs, which is conserved in a large and diverse group of distant relatives of the CDCs. IMPORTANCE The cholesterol-dependent cytolysins’ pore-forming mechanism relies on the ability to sense the completion of the oligomeric prepore structure and initiate the insertion of the β-barrel pore from the assembled prepore structure. These studies show that a conserved motif is an important component of the sensor that triggers the prepore-to-pore transition and that it is conserved in a large family of previously unidentified CDC-like proteins, the genes for which are present in a vast array of microbial species that span most terrestrial environments, as well as most animal and human microbiomes. These studies establish the foundation for future investigations that will probe the contribution of this large family of CDC-like proteins to microbial survival and human disease.

Objectives: The dissemination of antibiotic resistance genes (ARGs) from the environment, including agricultural sources, is of increasing concern. In this study, we examined the antibiotic resistance profile and genomic sequence of a strain of Chryseobacterium indoltheticum obtained from an agricultural location., Methods: The multidrug-resistant bacterial strain POL15 was isolated from the wastewater of a livestock farm in China. Whole-genome sequencing was performed followed by bioinformatics analyses to identify integrative and conjugative elements (ICEs) and ARGs. Mating assays were performed to analyse ICE transferability., Results: Whole-genome sequencing and annotation showed that the genome of POL15 encodes ARGs. Additionally, an ICE named ICECiPOL15, which carries a class C β-lactamase-encoding gene bla AQU , was identified in the POL15 genome. Genes encoding an integrase, an excisionase, a relaxase, a type IV coupling protein and conjugative transposon proteins involved in a type IV secretion system were also identified in ICECiPOL15. Sequence alignment revealed that ICECiPOL15 might have evolved from other Chryseobacterium species. The horizontal transferability of ICECiPOL15 was demonstrated by mating experiments between C. indoltheticum POL15 and Escherichia coli DL21., Conclusions: This study represents the first characterization of a mobilizable antibiotic resistance ICE in a species of C. indoltheticum and provides evidence that C. indoltheticum strains could be important reservoirs and vehicles for ARGs on livestock farms., Competing Interests: Conflict of interest The authors declare that we have no competing interests., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Flavobacterial infection associated with diseased fish is caused by multiple bacterial species within the family Flavobacteriaceae. In the present study, the Chilean isolate FP99, from the gills of a diseased, farmed rainbow trout (Oncorhynchus mykiss), was characterized using phenotypic and genomic analyses. Additionally assessed was pathogenic activity. Phylogenetic analysis based on 16S rRNA gene sequencing confirmed that isolate FP99 belonged to the genus Epilithonimonas, an average nucleotide identity value of 100% was detected with the Chilean isolate identified as Epilithonimonas sp. FP211-J200. In silico genome analysis, mechanisms for toxins production, and superantigens, adhesion, or other genes associated with virulence were not detected. However, genes encoding proteins for antibiotic resistance were found, including the chrA gene and the nucleotide sequence that encodes for multiple antibiotic resistance MarC proteins. Furthermore, the bla ESP-1 gene (87.85% aminoacidic sequence identity), encoding an extended-spectrum subclass B3 metallo-β-lactamase and conferring carbapenem-hydrolysing activity, and the tet(X) gene, which encodes a monooxygenase that catalyses the degradation of tetracycline-class antimicrobials were carried by this isolate. Phenotyping analyses also supported assignment as E. ginsengisoli. Challenge trials against healthy rainbow trout resulted in no observed pathogenic effect. Our findings identify for the first time the species E. ginsengisoli as associated with fish farming, suggesting that this isolate may be a component of the microbiota of the freshwater system. Notwithstanding, poor environmental conditions and any stressors associated with aquaculture situations or lesions caused by other pathogenic bacteria, such as F. psychrophilum, could favour the entry of E. ginsengisoli into rainbow trout., (© 2023 John Wiley & Sons Ltd.)

A Gram-stain-negative, aerobic, rod-shaped bacterial strain, designated MMS21-Ot14 T , was isolated from a freshwater river, and shown to represent a novel species of the genus Chryseobacterium on the basis of the results from a polyphasic approach. The 16S rRNA gene sequence analysis revealed that MMS21-Ot14 T represented a member of the genus Chryseobacterium of the family Weeksellaceae and was closely related to Chryseobacterium hagamense RHA2-9 T (97.52 % sequence similarity), Chryseobacterium gwangjuense THG A18 T (97.46 %) and Chryseobacterium gregarium P 461/12 T (97.27 %). The optimal growth of MMS21-Ot14 T occurred at 25-30 °C, pH 6.0-7.0 and in the absence of NaCl. MMS21-Ot14 T was capable of hydrolysing casein, starch, DNA, Tween 20 and tyrosine. The strain also showed keratinolytic activity with keratin azure and decolourising activity with remazol brilliant blue R (RBBR), which indicated potential ability to degrade keratin and lignin. The main polar lipids of MMS21-Ot14 T were phosphatidylethanolamine, unidentified aminophospholipids, unidentified aminolipids, an unidentified phospholipid and several unidentified lipids. The predominant fatty acids of MMS21-Ot14 T were iso-C 15 : 0 and iso-C 17 : 0 3-OH, and the major isoprenoid quinone was menaquinone 6 (MK-6). The whole genome of MMS21-Ot14 T was 5 062 016 bp in length with a DNA G+C content of 37.7 %. The average nucleotide identity and digital DNA-DNA hybridisation values between MMS21-Ot14 T and phylogenetically related members of the genus Chryseobacterium were well below the threshold values for species delineation. It is evident from the results of this study that MMS21-Ot14 T should be classified as representing a novel species of the genus Chryseobacterium , for which the name Chryseobacterium fluminis sp. nov. (type strain, MMS21-Ot14 T = KCTC 92255 T = LMG 32529 T ) is proposed.

Background: Elizabethkingia meningoseptica is an emerging nosocomial pathogen implicated in neonatal sepsis with high mortality and morbidities. However, there is very limited data regarding the characteristics as well as outcomes following this infection, particularly in developing countries., Methods: We conducted a retrospective observational study of all infants with culture-positive Elizabethkingia sepsis as part of an outbreak, to study their clinical and epidemiological characteristics, as well as their antimicrobial susceptibility patterns, using a structured proforma from the neonatal intensive care unit database. Analysis was done using descriptive statistics and predictors of mortality and hydrocephalus were also identified., Results: Of the 21 neonates enrolled, 9 (42.9%) were male, with a mean gestational age and birth weight of 31.7 ± 3.4 weeks and 1320 ± 364 g, respectively. The median (interquartile range) age of onset of illness was 7 (5-12) days. The overall mortality rate was 23.8%, and among survivors, 50% had neurologic complications requiring intervention. Vancomycin and ciprofloxacin were the most used antibiotics for treatment in our series, with a median duration of 26 (17-38) days. On univariate analysis, shock at presentation was significantly associated with increased mortality (P = 0.04) while, seizures (P = 0.04) and elevated cerebrospinal fluid protein levels (P = 0 .01) at onset of illness predicted progressive hydrocephalus in surviving neonates., Conclusion: E. meningoseptica sepsis is associated with high morbidity and mortality. Early diagnosis and prompt initiation of appropriate antibiotics are critical for improving survival and neurodevelopmental outcomes. Though isolation of the organism by environmental surveillance is always not possible, with proper infection control measures, the infection can be controlled., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Two Gram-stain-negative, rod-shaped, gliding, catalase-positive, and facultative anaerobic strains, YLOS41T and XH07, were isolated from surface water of Yilong Lake and West Lake of Dali in Yunnan Province, respectively. Both strains were yellow-colored under light conditions and white-colored under dark conditions. The results of physiological and chemotaxonomic characterization, sequencing and phylogenetic analysis, and draft genome sequence comparison demonstrated that the two strains represented a single novel species within the genus Chryseobacterium, for which the name Chryseobacterium lacus sp. nov. is proposed. The type strain is YLOS41T (= KCTC 62352T = MCCC 1H00300T), and the second strain is XH07 (= KCTC 62993). During the cultivation process, we found that the colony color of the two strains changed from white to yellow with illumination. The study investigated the effects of light irradiation on the strain YLOS41T. Results showed that light irradiation did not affect the growth of cells but significantly increased carotenoid synthesis, which caused the change of colony color. In-depth metabolic analysis was conducted by transcriptome. The predominant changes were found for genes involved in carotenoid synthesis as protection from light damage. Based on the genome and transcriptome, we proved that strain YLOS41T possessed a complete synthetic pathway of carotenoid and speculated that the production was zeaxanthin. This was the first report of Chryseobacterium species with light-induced carotenoid synthesis. This study enhances our present knowledge on how Chryseobacterium species isolated from surface water responds to light damage.

Stenotrophomonas maltophilia, Burkholderia cepacia complex, Elizabethkingia spp., Chryseobacterium spp., Achromobacter spp., and Alcaligenes spp. are less‐common non–lactose‐fermenting bacteria that have emerged as important opportunistic pathogens. Patients at the highest risk for these infections include the immunocompromised, those with cystic fibrosis, and the critically ill. These opportunistic pathogens are frequently drug resistant through the expression of β‐lactamases, multidrug efflux pumps, aminoglycoside‐modifying enzymes, and target site alterations discussed in detail throughout this review. As a result, treatment is extremely challenging. For each pathogen, this review will examine the epidemiology, mechanisms of resistance, and in vitro and in vivo data including that for novel β‐lactam/β‐lactamase inhibitors and cefiderocol. Treatment recommendations are provided based on the available literature. [ABSTRACT FROM AUTHOR]

A Gram-stain-negative, non-motile, rod-shaped bacterial strain, designated NBC 122T, was isolated from freshwater of the Nakdong River Republic of Korea. Growth occurred at pH 5.0–8.0 (optimum, pH 7.0), at 4–37 °C (optimum, 25 °C), and with 0–3.5% (w/v) NaCl (optimum, 1%). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain NBC 122T belongs to the genus Chryseobacterium and is most closely related to Chryseobacterium antarcticum AT1013T (97.85%). The average nucleotide identity and in silico DNA–DNA hybridization (DDH) values between strain NBC 122T and related Chryseobacterium species were 77.77–80.28 and 20.9–23.2%, respectively. The strain NBC 122T contained MK-6 as the major respiratory quinone. The major fatty acids included anteiso C15:0, iso C15:0, summed feature 9 (C17:1 iso ω9c, C16:0 10-methyl) and iso C17:0 3-OH, and the polar lipids were phosphatidylethanolamine, five unidentified aminolipids and six unidentified lipids. The DNA G + C content was 37.5 mol%. On the basis of a 16S rRNA gene phylogeny and comparative phenotypic analyses, strain NBC 122T represents a novel species in the genus Chryseobacterium, for which the name Chryseobacterium salivictor sp. nov. is proposed. The type strain is NBC122T (= KCTC 72248T = JCM 33980T). [ABSTRACT FROM AUTHOR]

Two Gram-stain-negative, rod-shaped, gliding, catalase-positive, and facultative anaerobic strains, YLOS41T and XH07, were isolated from surface water of Yilong Lake and West Lake of Dali in Yunnan Province, respectively. Both strains were yellow-colored under light conditions and white-colored under dark conditions. The results of physiological and chemotaxonomic characterization, sequencing and phylogenetic analysis, and draft genome sequence comparison demonstrated that the two strains represented a single novel species within the genus Chryseobacterium , for which the name Chryseobacterium lacus sp. nov. is proposed. The type strain is YLOS41T (= KCTC 62352T = MCCC 1H00300T), and the second strain is XH07 (= KCTC 62993). During the cultivation process, we found that the colony color of the two strains changed from white to yellow with illumination. The study investigated the effects of light irradiation on the strain YLOS41T. Results showed that light irradiation did not affect the growth of cells but significantly increased carotenoid synthesis, which caused the change of colony color. In-depth metabolic analysis was conducted by transcriptome. The predominant changes were found for genes involved in carotenoid synthesis as protection from light damage. Based on the genome and transcriptome, we proved that strain YLOS41T possessed a complete synthetic pathway of carotenoid and speculated that the production was zeaxanthin. This was the first report of Chryseobacterium species with light-induced carotenoid synthesis. This study enhances our present knowledge on how Chryseobacterium species isolated from surface water responds to light damage. [ABSTRACT FROM AUTHOR]

Climatic factors and pathogenic fungi threaten global banana production. Moreover, bananas are being cultivated using excessive amendments of nitrogen and pesticides, which shift the microbial diversity in plants and soil. Advances in high-throughput sequencing (HTS) technologies and culture-dependent methods have provided valuable information about microbial diversity and functionality of plant-associated endophytic communities. Under stressful (biotic or abiotic) conditions, plants can recruit sets of microorganisms to alleviate specific potentially detrimental effects, a phenomenon known as “cry for help”. This mechanism is likely initiated in banana plants infected by Fusarium wilt pathogen. Recently, reports demonstrated the synergistic and cumulative effects of synthetic microbial communities (SynComs) on naturally occurring plant microbiomes. Indeed, probiotic SynComs have been shown to increase plant resilience against biotic and abiotic stresses and promote growth. This review focuses on endophytic bacterial diversity and keystone taxa of banana plants. We also discuss the prospects of creating SynComs composed of endophytic bacteria that could enhance the production and sustainability of Cavendish bananas (Musa acuminata AAA), the fourth most important crop for maintaining global food security.

Importance: Elizabethkingia meningoseptica is an emerging infectious agent associated with life-threatening infections in immunocompromised individuals. However, there are limited data available on the genomic features of E. meningoseptica . This study aims to characterize the geographical distribution, phylogenetic evolution, pathogenesis, and transmission of this bacterium. A systematic analysis of the E. meningoseptica genome revealed that a common ancestor of this bacterium existed 90 years ago. The evolutionary history showed no significant relationship with the sample source, origin, or region, despite the presence of genetic diversity. Whole genome sequencing data also demonstrated that E. meningoseptica bacteria possess inherent resistance and pathogenicity, enabling them to spread within the same hospital and even across borders. This study highlights the potential for E. meningoseptica to cause severe nosocomial outbreaks and horizontal transmission between countries worldwide. The available evidence is crucial for the development of evidence-based public health policies to prevent global outbreaks caused by emerging pathogens., Competing Interests: The authors declare no conflict of interest.