Comparative resistomics analysis of multidrug-resistant Chryseobacteria.

Chryseobacteria consists of important human pathogens that can cause a myriad of nosocomial infections. We isolated four multidrug-resistant Chryseobacterium bacteria from activated sludge collected at domestic wastewater treatment facilities in the New York Metropolitan area. Their genomes were sequenced with Nanopore technology and used for a comprehensive resistomics comparison with 211 Chryseobacterium genomes available in the public databases. A majority of Chryseobacteria harbor 3 or more antibiotic resistance genes (ARGs) with the potential to confer resistance to at least two types of commonly prescribed antimicrobials. The most abundant ARGs, including ß-lactam class A (blaCGA-1 and blaCIA) and class B (blaCGB-1 and blaIND) and aminoglycoside (ranA and ranB), are considered potentially intrinsic in Chryseobacteria. Notably, we reported a new resistance cluster consisting of a chloramphenicol acetyltransferase gene catB11, a tetracycline resistance gene tetX, and two mobile genetic elements (MGEs), IS91 family transposase and XerD recombinase. Both catB11 and tetX are statistically enriched in clinical isolates as compared to those with environmental origins. In addition, two other ARGs encoding aminoglycoside adenylyltransferase (aadS) and the small multidrug resistance pump (abeS), respectively, are found co-located with MGEs encoding recombinases (e.g., RecA and XerD) or transposases, suggesting their high transmissibility among Chryseobacteria and across the Bacteroidota phylum, particularly those with high pathogenicity. High resistance to different classes of ß-lactam, as well as other commonly used antimicrobials (i.e., kanamycin, gentamicin, and chloramphenicol), was confirmed and assessed using our isolates to determine their minimum inhibitory concentrations. Collectively, though the majority of ARGs in Chryseobacteria are intrinsic, the discovery of a new resistance cluster and the co-existence of several ARGs and MGEs corroborate interspecies and intergenera transfer, which may accelerate their dissemination in clinical environments and complicate efforts to combat bacterial infections.

Chryseobacterium gotjawalense sp. nov. Isolated from Soil in the Volcanic Forest Gotjawal, Jeju Island.

Strain wdc7T, a rod-shaped bacterium, was isolated from soil in the Gotjawal Forest on Jeju Island, South Korea. Strain wdc7T was Gram stain-negative, facultatively anaerobic, catalase- and oxidase positive, yellow pigmented, and non-flagellated. It grew at 4-37 °C and pH 5.0-8.0 in 0-3% (w/v) NaCl. 16S rRNA gene sequencing analysis revealed that strain wdc7T belonged to the genus Chryseobacterium and was most closely related to Chryseobacterium salivictor NBC 122T, with a sequence similarity of 98.51%. Menaquinone 6 was the sole respiratory quinone, and C15:0 anteiso, C15:0 iso, and summed feature 9 were the major fatty acids. The genome length was 3.30 Mbp, with a 37% G + C content. Average amino acid identity, average nucleotide identity, and digital DNA-DNA relatedness between strain wdc7T and C. salivictor NBC 122T were 93.52%, 92.80%, and 49.7%, respectively. Digital genomic and polyphasic analyses showed that strain wdc7T likely represented a new species of the genus Chryseobacterium. We proposed the name Chryseobacterium gotjawalense sp. nov., with wdc7T (= KCTC 92440T = JCM 35602T) as the type strain.

Characterization and Comparative Genomic Analysis of a Highly Colistin-Resistant Chryseobacterium gallinarum: a Rare, Uncommon Pathogen.

For the first time, we describe the whole genome of a yellow-pigmented, capsule-producing, pathogenic, and colistin-resistant Chryseobacterium gallinarum strain MGC42 isolated from a patient with urinary tract infection in India. VITEK 2 automated system initially identified this isolate as C. indologenes. However, 16S rRNA gene sequencing revealed that MGC42 shared 99.67% sequence identity with C. gallinarum-type strain DSM 27622. The draft genome of the strain MGC42 was 4,455,926 bp long with 37.08% Guanine-Cytosine (GC) content and was devoid of any plasmid. Antibiotic resistance, virulence, and toxin genes were predicted by implementing a machine learning classifier. Potential homologs of 340 virulence genes including hemolysin secretion protein D, metalloprotease, catalase peroxidases and autotransporter adhesins, type VI secretion system (T6SS) spike proteins, and 27 toxin factors including a novel toxin domain Ntox23 were identified in the genome. Kyoto Encyclopedia of Genes and Genomes (KEGG) orthologs of 110 transporter proteins were predicted that were in agreement with moderate efflux activity. Twelve antibiotic resistance genes including two potentially novel putative ß-lactamase genes sharing low similarity with known ß-lactamase genes were also identified in the genome of this strain. The strain MGC42 was also resistant to several classes of antibiotics along with carbapenems and polymyxin. We also identified mutations in the orthologs of pmrB (M384T) and lpxD (I66V) that might be responsible for colistin resistance. The MGC42 strain shared 683 core genes with other environmental and clinical strains of Chryseobacterium species. Our findings suggest that the strain MGC42 is a multidrug-resistant, virulent pathogen and recommend 16S rRNA gene sequencing to identify clinical specimens of Chryseobacterium species.

Chryseobacterium lecithinasegens sp. nov., a siderophore-producing bacterium isolated from soil at the bottom of a pond.

Bacterial strain PAGU 2197T, which was isolated from soil collected from the bottom of a pond in Japan, is characterized in this study. Cells of strain PAGU 2197T were aerobic, Gram-negative, short rod-shaped, non-motile, flexirubin-producing, oxidase-positive, catalase-positive and lecithinase-negative. A phylogenetic study based on 16S rRNA gene sequences and multilocus sequence analysis (gyrB, rpoB and rpoD) indicated that strain PAGU 2197T belongs to the genus Chryseobacterium and is a member of an independent lineage including Chryseobacterium tructae CCUG 60111T (sequence similarity, 95.9 %), Chryseobacterium lactis CCUG 60566T (93.4 %) and Chryseobacterium viscerum CCUG 60103T (91.6 %). The average nucleotide identity values were 80.83-85.04 %. Because average nucleotide identity values of 95-96 % exceed the 70 % DNA-DNA hybridization cutoff value for species discrimination, strain PAGU 2197T represents a novel species in the genus Chryseobacterium. The genome of strain PAGU 2197T was 4 967 738 bp with a G+C content of 35.5 mol%. The sole respiratory quinone of strain PAGU 2197T was MK-6; the major cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3OH, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl); and the major polar lipids were phosphoglycolipids and phosphatidylethanolamine. These results indicate that strain PAGU 2197T should be classified as representing a novel species in the genus Chryseobacterium, for which the name Chryseobacterium lecithinasegens sp. nov. is proposed, with strain PAGU 2197T (=NBRC 114264T=CCUG 75150T) as the type strain.

The Integrative and Conjugative Element ICECspPOL2 Contributes to the Outbreak of Multi-Antibiotic-Resistant Bacteria for Chryseobacterium Spp. and Elizabethkingia Spp.

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 endalhagicum sp. nov., isolated from seed of leguminous plant.

A Gram-stain-negative, yellow-pigmented bacterium, designated as L7T, was isolated from seeds of Alhagi sparsifolia Shap., a leguminous plant that grows in northwest PR China. Strain L7T was found to be non-flagellated, non-spore forming rods which can grow at 10-37 °C, pH 6.0-8.5 and in 0-3 % (v/w) NaCl concentration. The 16S rRNA gene sequence analysis showed that strain L7T belongs to the genus Chryseobacterium with sequence similarities to Chryseobacterium vietnamense GIMN1.005T (98.1%), C. bernardetii NCCTC13530T (98.0%), C. vrystaatense LMG 22846T (97.9%), C. nakagawai NCTC13529T (97.7%), C. shigense DSM 17126T (97.6%) and C. rhizosphaerae RSB3-1T (97.5%). The average nucleotide identity of strain L7T to 31 reference strains were 78.6-85.6 %, lower than the species delineation threshold of 95 %. MK-6 was the only respiratory quinone of L7T and major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 1 ω7c and/or C16 : 1 ω6c, isoC17 : 1 ω9c and/or C16 : 0 10-methyl. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminophospholipids, two unidentified aminolipids, three unidentified glycolipids and two unidentified lipids. The G+C content of the genome was 38.58 mol%. On the basis of polyphasic taxonomy analyses in this study, strain L7T is considered to represent a novel species in the genus Chryseobacterium, for which the name Chryseobacterium endalhagicum sp. nov. is proposed. The type strain is L7T (=MCCC 1K05687T=JCM 34506T).

Chryseobacterium panacisoli sp. nov., isolated from ginseng-cultivation soil with ginsenoside-converting activity.

A Gram-stain-negative, non-motile, non-spore-forming, aerobic, rod-shaped and yellow-pigmented bacterium, designated strain Gsoil 183T, was isolated from ginseng-cultivation soil sampled in Pocheon Province, Republic of Korea. This bacterium was characterized to determine its taxonomic position by using a polyphasic approach. Strain Gsoil 183T grew at 10-37 °C and at pH 5.0-9.0 on tryptic soy agar. Strain Gsoil 183T had ß-glucosidase activity, which was responsible for its ability to convert ginsenoside Rb1 (one of the dominant active components of ginseng) to F2. Based on 16S rRNA gene sequencing, strain Gsoil 183T clustered with species of the genus Chryseobacterium and appeared to be closely related to Chryseobacterium sediminis LMG 28695T (99.1 % sequence similarity), Chryseobacterium lactis NCTC 11390T (98.6%), Chryseobacterium rhizoplanae LMG 28481T (98.6%), Chryseobacterium oncorhynchi CCUG 60105T (98.5%), Chryseobacterium viscerum CCUG 60103T (98.4%) and Chryseobacterium joostei DSM 16927T (98.3%). Menaquinone MK-6 was the predominant respiratory quinone and the major fatty acids were iso-C15 : 0, iso-C17 : 0-3OH and summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c). The polar lipids were phosphatidylethanolamine, six unidentified glycolipids, five unidentified aminolipids and three unidentified lipids. The G+C content of the genomic DNA was 36.6 mol%. Digital DNA-DNA hybridization between strain Gsoil 183T and the type strains of C. sediminis, C. lactis, C. rhizoplanae, C. oncorhynchi, C. viscerum and C. joostei resulted in values below 70 %. Strain Gsoil 183T could be differentiated genotypically and phenotypically from the recognized species of the genus Chryseobacterium. The isolate therefore represents a novel species, for which the name Chryseobacterium panacisoli sp. nov. is proposed, with the type strain Gsoil 183T (=KACC 15033T=LMG 23397T).

Chryseobacterium caseinilyticum sp. nov., a casein hydrolyzing bacterium isolated from rice plant and emended description of Chryseobacterium piscicola.

A novel Gram-stain-negative, aerobic, asporogenous, catalase-positive and oxidase-negative, non-motile, golden-yellow pigmented, rod-shaped bacterium with casein-degrading ability, designated strain GCR10T, was isolated from roots of rice plants collected from a paddy field near Dongguk University, Republic of Korea. The results of subsequent 16S rRNA gene sequence analysis indicated that GCR10T shares the highest sequence identity with Chryseobacterium piscicola VQ-6316sT (98.3%). Strain GCR10T grew at 2-32 °C (optimum, 25 °C), at pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0-2.0% (w/v) NaCl (optimum in the absence of NaCl). The novel strain was able to produce carotenoid and flexirubin-type pigments. The predominant menaquinone was MK-6 and the major fatty acids were identified as iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1ω9c. The polar lipids were phosphatidylethanolamine, four unidentified aminoglycolipids, two unidentified aminolipids and two unidentified glycolipids. The genome of GCR10T is 4.3 Mb in length with a DNA G+C content of 36.5 mol%. Average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between GCR10T and Chryseobacterium piscicola VQ-6316sT were 82.1, 25.2 and 84.3 %, respectively, which clearly indicates that the novel strain is distinct from its closest relative. The demand for natural biodegradable pigments isolated frominsects, plants or microorganisms is increasing day by day because of their beneficial pharmacological properties. Here, we describe a novel strain that produces two types of pigment, carotenoid and flexirubin. On the basis of the results from phenotypic, genotypic and chemotaxonomic analyses, strain GCR10T represents a novel species of the genus Chryseobacterium, and the name Chryseobacterium caseinilyticum sp. nov. is proposed. The type strain is GCR10T (=KACC 21707T=NBRC 114715T).

Chryseobacterium pennae sp. nov., isolated from poultry feather waste.

A Gram-stain-negative, rod-shaped, non-motile, non-spore-forming, aerobic, yellow-pigmented bacterium was isolated from chicken feather waste collected from an abattoir in Bloemfontein, South Africa. A polyphasic taxonomy study was used to describe and name the bacterial isolate, strain 1_F178T. The 16S rRNA gene sequence analysis and sequence comparison data indicated that strain 1_F178T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium jejuense (99.1%) and Chryseobacterium nakagawai (98.7%). Overall genome similarity metrics (average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity) revealed greatest similarity to the C. jejuense and C. nakagawai type strains but were below the threshold for species delineation. Genome sequencing revealed a genome size of 6.18 Mbp and a G+C content of 35.6 mol%. The major respiratory quinone and most abundant polar lipid of strain 1_F178T were menaquinone-6 and phosphatidylethanolamine, respectively. Strain 1_F178T had a typical fatty acid composition for Chryseobacterium species. On the basis of physiological, genotypic, phylogenetic and chemotaxonomic data, strain 1_F178T constitutes a novel species of Chryseobacterium, for which the name Chryseobacterium pennae sp. nov. is proposed. The type strain is 1_F178T (=LMG 30779T=KCTC 62759T).

Comparison of three species of Elizabethkingia genus by whole-genome sequence analysis.

Elizabethkingia are found to cause severe neonatal meningitis, nosocomial pneumonia, endocarditis and bacteremia. However, there are few studies on Elizabethkingia genus by comparative genomic analysis. In this study, three species of Elizabethkingia were found: E. meningoseptica, E. anophelis and E. miricola. Resistance genes and associated proteins of seven classes of antibiotics including beta-lactams, aminoglycosides, macrolides, tetracyclines, quinolones, sulfonamides and glycopeptides, as well as multidrug resistance efflux pumps were identified from 20 clinical isolates of Elizabethkingia by whole-genome sequence. Genotype and phenotype displayed a good consistency in beta-lactams, aminoglycosides and glycopeptides, while contradictions exhibited in tetracyclines, quinolones and sulfonamides. Virulence factors and associated genes such as hsp60 (htpB), exopolysaccharide (EPS) (galE/pgi), Mg2+ transport (mgtB/mgtE) and catalase (katA/katG) existed in all clinical and reference strains. The functional analysis of the clusters of orthologous groups indicated that 'metabolism' occupied the largest part in core genome, 'information storage and processing' was the largest group in both accessory genome and unique genome. Abundant mobile elements were identified in E. meningoseptica and E. anophelis. The most significant finding in our study was that a single clone of E. anophelis had been circulating within diversities of departments in a clinical setting for nearly 18 months.

Septic Arthritis and Osteomyelitis Caused by Chryseobacterium indologenes in a Mute Swan (Cygnus olor) and a Ring-Billed Gull (Larus delawarensis).

A 20-year-old female mute swan (Cygnus olor) originally in a flock of free-living swans on a Long Island, New York, lake, was presented for facial swelling and decreased appetite. An adult male ring-billed gull (Larus delawarensis) was also presented to the same wildlife rescue center for bilateral lameness of 1-week duration. Once referred for veterinary evaluation and care, both species were diagnosed with septic arthritis and osteomyelitis caused by Chryseobacterium indologenes and treated with orbifloxacin until complete recovery. Chryseobacterium indologenes is infrequently diagnosed as an opportunistic pathogen in human medicine, and less so in veterinary medicine. In human patients, this bacterium is the cause of various infections, including meningitis, pneumonia, and implant failure. However, in veterinary medicine its pathogenicity has only been reported in fish, and sporadically mentioned as a culture result in tree frogs and turtles, where it was generally considered insignificant. In this report a clinical presentation, diagnosis, treatment, and outcome of osteomyelitis and septic arthritis caused by C indologenes is described in 1 anseriforme and in 1 charadriiforme species.

Endoparasites infecting exotic captive amphibian pet and zoo animals (Anura, Caudata) in Germany.

Alongside exotic reptiles, amphibians, such as toads, frogs, salamanders, and newts, are nowadays considered popular pets worldwide. As reported for other exotic pet animals, amphibians are known to harbor numerous gastrointestinal parasites. Nonetheless, very little data are available on captive amphibian parasitic diseases. In this study, we applied direct saline fecal smears (DSFS) to examine in total 161 stool samples from 41 different amphibian species belonging to the orders Anura and Caudata. In addition, carbolfuchsin-smear (CFS) staining (n = 74 samples) was used to detect amphibian Cryptosporidium oocysts. Also, complete dissections of deceased amphibians (n = 107) were performed to specify parasite infections and to address parasite-associated pathogenicity. Overall, examined amphibian fecal samples contained 12 different parasite taxa. The order Rhabditida with the species Rhabdias spp. and Strongyloides spp. were the most prevalent nematode species (19.3%), followed by flagellated protozoans (8.7%), Amphibiocapillaria spp./Neocapillaria spp. (7.5%), Oswaldocruzia spp. (4.3%), Blastocystis spp. (3.1%), Cosmocerca spp. (3.1%), oxyurids (Pharyngonoidae) (3.1%), spirurids (1.2%), un-sporulated coccidian oocysts (0.6%), Tritrichomonas spp. (0.6%), Karotomorpha spp. (0.6%), and Cryptosporidium spp. (0.6%). One CFS-stained fecal sample (1.4%) was positive for Cryptosporidium oocysts. Within dissected amphibians, 31 (48.4%) of the anurans and 11 (26.2%) of the salamanders were infected with gastrointestinal parasites. One cutaneous Pseudocapillaroides xenopi infection was diagnosed in an adult African clawed frog (Xenopus laevis). Etiologically, 17 (15.9%) of them died due to severe parasitic and/or bacterial infections (e.g., Chryseobacterium indologenes, Citrobacter freudii, Sphingobacterium multivorum, Klebsiella pneumoniae). High prevalence and pathological findings of several clinical amphibian parasitoses call for more detailed investigation on gastrointestinal parasite-derived molecular mechanisms associated with detrimental lesions or even death.

Manganese-contaminated groundwater treatment by novel bacterial isolates: kinetic study and mechanism analysis using synchrotron-based techniques.

The occurrence of manganese in groundwater causes coloured water and pipe rusting in water treatment systems. Consumption of manganese-contaminated water promotes neurotoxicity in humans and animals. Manganese-oxidizing bacteria were isolated from contaminated areas in Thailand for removing manganese from water. The selected bacterium was investigated for its removal kinetics and mechanism using synchrotron-based techniques. Among 21 isolates, Streptomyces violarus strain SBP1 (SBP1) was the best manganese-oxidizing bacterium. At a manganese concentration of 1 mg L-1, SBP1 achieved up to 46% removal. The isolate also successfully removed other metal and metalloid, such as iron (81%) and arsenic (38%). The manganese concentration played a role in manganese removal and bacterial growth. The observed self-substrate inhibition best fit with the Aiba model. Kinetic parameters estimated from the model, including a specific growth rate, half-velocity constant, and inhibitory constant, were 0.095 h-1, 0.453 mg L-1, and 37.975 mg L-1, respectively. The synchrotron-based techniques indicated that SBP1 removed manganese via combination of bio-oxidation (80%) and adsorption (20%). The study is the first report on biological manganese removal mechanism using synchrotron-based techniques. SBP1 effectively removed manganese under board range of manganese concentrations. This result showed the potential use of the isolate for treating manganese-contaminated water.

Chryseobacterium vaccae sp. nov., isolated from raw cow's milk.

Strain CA7T, a Gram-stain-negative, non-motile, non-spore-forming, aerobic and rod-shaped bacterial strain, was isolated from raw cow's milk collected from a farm affiliated with Chung-Ang University, Anseong, Korea, and characterized by a polyphasic approach. Optimal growth of strain CA7T was observed on tryptic soy agar at 30 °C and pH 7.0 with 0 % NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain CA7T belonged to the genus Chryseobacterium. The most closely related strains (16S rRNA gene sequence similarity indicated in parentheses), based on the phylogenetic analysis, were Chryseobacterium rhizosphaerae KCTC 22548T (98.08 %), Chryseobacterium nakagawai CCUG 60563T (98.61 %), Chryseobacterium jejuense KACC 12501T (97.85 %) and Chryseobacterium aurantiacum KCTC 62135T (97.78 %). Whole genome sequencing indicated that the genome size was 5 125 723 bp and had a DNA G+C content of 37.4 mol%. Average nucleotide identity values for strain CA7T with C. rhizosphaerae, C. nakagawai, C. jejuense, C. aurantiacum, and the type species of the genus Chryseobacterium, C. gleum, were 80.2, 79.8, 79.8, 79.6 and 80.4 %, respectively. The digital DNA-DNA hybridization values of CA7T compared to C. rhizosphaerae, C. nakagawai, C. jejuense, C. aurantiacum and C. gleum were 24.1, 23.9, 23.9, 23.7 and 24.3 %, respectively. The major fatty acids were iso-C15 : 0, summed feature 9 (iso-C17 : 1 ω9c and/or C16 : 0 10-methyl), iso-C17 : 0 3-OH and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1 ω7c). Menaquinone-6 was the only respiratory quinone. The major polar lipid was phosphatidylethanolamine. Based on this polyphasic taxonomic study, strain CA7T represents a novel species of the genus Chryseobacterium for which the name Chryseobacterium vaccae sp. nov. is proposed. The type strain is CA7T (=KACC 21402T=JCM 33749T).

Chryseobacterium salivictor sp. nov., a plant-growth-promoting bacterium isolated from freshwater.

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).

Chryseobacterium gleum Isolation from Respiratory Culture Following Community-Acquired Pneumonia.

BACKGROUND Chryseobacterium gleum (C. gleum) is a rare but concerning device-associated infection that can cause urinary tract infections and pneumonia. It produces a biofilm and has intrinsic resistance to a wide array of broad-spectrum agents. Risk factors include neonate or immunocompromised states, intensive care unit admission for more than 21 days, broad-spectrum antibiotic exposure, indwelling devices, and mechanical ventilation. CASE REPORT A 61-year-old cachectic man presented in the United States with community-acquired pneumonia and immediately decompensated, requiring ventilator support. Despite starting broad-spectrum antibiotics, the patient developed fever, leukocytosis, and additional desaturation episodes. The patient's respiratory culture grew numerous C. gleum and few Stenotrophomonas (Xanthomonas) maltophilia. He also had a positive urine streptococcal pneumonia antigen. Broad-spectrum agents were discontinued after prolonged treatment due to a continued worsening clinical picture, and the patient was started on trimethoprim-sulfamethoxazole to cover C. gleum. The patient showed rapid clinical improvement on trimethoprim-sulfamethoxazole, with resolution of symptoms on post-discharge follow-up. CONCLUSIONS To the best of our knowledge, this is the first case report of a documented case of a patient with C. gleum respiratory infection successfully treated solely with trimethoprim-sulfamethoxazole. The expedient identification of C. gleum is essential for proper treatment. The literature has consistently shown isolated respiratory C. gleum strains to be largely susceptible to fluoroquinolones, piperacillin-tazobactam, or trimethoprim-sulfamethoxazole.

Chryseobacterium/Elizabethkingia species infections in Saudi Arabia.

OBJECTIVES: To describe the epidemiological, clinical, and outcome data of patients infected or colonized with Chryseobacterium/Elizabethkingia spp including antibiotic susceptibility patterns. METHODS: This retrospective study was conducted at Prince Sultan Military Medical City, Riyadh,  Saudi Arabia. All patients infected or colonized by Chryseobacterium /Elizabethkingia spp who were admitted between June 2013 and May 2019 were included. Data were extracted from patient electronic medical records. RESULTS: We enrolled 27 patients (13 males and 14 females) with a mean age of 35.6 years. Chryseobacterium/Elizabethkingia spp were isolated from blood cultures (n=13, 48%) and tracheal aspirations (n=11, 41%). The most frequent species isolated was Elizabethkingia meningoseptica (n=22). Although 6 patients were considered colonized, the remaining 21 patients presented with ventilator associated pneumonia (n=9), central line associated bloodstream infection (n=4), septic shock (n=4), or isolated bacteremia (n=4). In 25 cases the infections were health-care related. Three patients (11%) died within 28 days. Twenty-six isolates (96.5%) were resistant to carbapenems. Moxifloxacin and cotrimoxazole were the most active antibiotics. CONCLUSION: Chryseobacterium/Elizabethkingia spp infection is rare, but can be responsible for severe hospital acquired infections. Cotrimoxazole and fluoroquinolone are the most effective antibiotic treatments.

Bacteria from the Midgut of Common Cockchafer (Melolontha melolontha L.) Larvae Exhibiting Antagonistic Activity Against Bacterial Symbionts of Entomopathogenic Nematodes: Isolation and Molecular Identification.

The mechanisms of action of the complex including entomopathogenic nematodes of the genera Steinernema and Heterorhabditis and their mutualistic partners, i.e., bacteria Xenorhabdus and Photorhabdus, have been well explained, and the nematodes have been commercialized as biological control agents against many soil insect pests. However, little is known regarding the nature of the relationships between these bacteria and the gut microbiota of infected insects. In the present study, 900 bacterial isolates that were obtained from the midgut samples of Melolontha melolontha larvae were screened for their antagonistic activity against the selected species of the genera Xenorhabdus and Photorhabdus. Twelve strains exhibited significant antibacterial activity in the applied tests. They were identified based on 16S rRNA and rpoB, rpoD, or recA gene sequences as Pseudomonas chlororaphis, Citrobacter murliniae, Acinetobacter calcoaceticus, Chryseobacterium lathyri, Chryseobacterium sp., Serratia liquefaciens, and Serratia sp. The culture filtrate of the isolate P. chlororaphis MMC3 L3 04 exerted the strongest inhibitory effect on the tested bacteria. The results of the preliminary study that are presented here, which focused on interactions between the insect gut microbiota and mutualistic bacteria of entomopathogenic nematodes, show that bacteria inhabiting the gut of insects might play a key role in insect resistance to entomopathogenic nematode pressure.

Chryseobacterium candidae sp. nov., isolated from a yeast (Candida tropicalis).

A Gram-stain-negative, rod shaped, non-motile, aerobic bacterium (strain JC507T) was isolated from a yeast (Candida tropicalis JY101). Strain JC507T was oxidase- and catalase-positive. Complete 16S rRNA gene sequence comparison data indicated that strain JC507T was a member of the genus Chryseobacterium and was closely related to Chryseobacterium indologenes NBRC 14944T (98.7 %), followed by Chryseobacterium arthrosphaerae CC-VM-7T (98.6 %), Chryseobacterium gleum ATCC 35910T (98.5 %) and less than 98.5 % to other species of the genus Chryseobacterium.The genomic DNA G+C content of strain JC507T was 36.0 mol%. Strain JC507T had phosphatidylethanolamine, four unidentified amino lipids and four unidentified lipids. MK-6 was the only respiratory quinone. The major fatty acids (>10 %) were anteiso-C11 : 0, iso-C15 : 0 and iso-C17 : 03OH. The average nucleotide identity and in silico DNA-DNA hybridization values between strain JC507T and C. indologenes NBRC 14944T, C. arthrosphaerae CC-VM-7T and C. gleum ATCC 35910T were 80.2, 83.0 and 87.0 % and 24, 26.7 and 32.7 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses support the inclusion of strain JC507T as a representative of a new species of the genus Chryseobacterium, for which the name Chryseobacteriumcandidae sp. nov. is proposed. The type strain is JC507T (=KCTC 52928T=MCC 4072T=NBRC 113872T).

Chryseobacterium binzhouense sp. nov., isolated from activated sludge.

A golden-pigmented, Gram-strain-negative, aerobic, rod-shaped, non-flagellated and non-gliding bacterium, designated strain lm2T, was isolated from activated sludge obtained from a wastewater treatment plant in Binzhou (Shandong province, PR China). Growth occurred at 15-45°C (optimum, 30 °C), in the presence of 0-5.0 % (w/v) NaCl (optimum, 0-2.0 %) and at pH 6.5-8.0 (optimum, pH 7.0-7.5). The chemotaxonomic, phenotypic and genomic traits were investigated. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain lm2T belonged to the genus Chryseobacterium, with highest sequence similarity to Chryseobacterium echinoideorum CC-CZW010T (97.1 %). Genome sequencing revealed a genome size of 3 611 894 bp and a G+C content of 34.9 mol%. The average nucleotide identity value and the digital DNA-DNA hybridization (dDDH) value between strain lm2T and C. echinoideorum JCM 30470T were 87.8 and 34.7 %, respectively. The major respiratory quinone was Menaquinone-6 (MK-6). The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C17 : 1 ω9c and its polar lipids consisted of phosphatidylethanolamine (PE), unidentified lipids (L1-5) and unidentified aminolipids (AL1-4). On the basis of these data, strain lm2T is considered to represent a novel species of the genus Chryseobacterium, for which the name Chryseobacterium binzhouense sp. nov. is proposed. The type strain is lm2T (=KCTC 72529T=CCTCC AB2019126T).