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Plant Disease Jan 2021Muskmelon ( L.) is an important economic crop in China, which is planted on more than 376, 000 hectares with over 13 million tons of annual fruit production. In February...
Muskmelon ( L.) is an important economic crop in China, which is planted on more than 376, 000 hectares with over 13 million tons of annual fruit production. In February 2020, a serious bacterial stem and leaf rot disease on muskmelon plants was observed in greenhouses in Liguo Town, Ledong County, Hainan Province, China (18.54° N, 108.87° E), with disease incidences being approximately 10 to 12%. Initially, soft rot symptoms appeared on petioles and stems, showing yellow bacterial ooze signs, which was different from the milky white ooze produced by infection. The infected tissues of petioles, stems, and leaves eventually developed into browning and withering symptoms. To isolate and identify the causal agent, the lesion tissues were sterilized by immersion in 75% ethanol for 30 s, washed three times with sterile water, and then cut and soaked in 1 ml of distilled water for 10 min. The suspension was serially diluted and spread on Luria-Bertani agar (LB) medium. After incubation at 28°C for 24 to 36 h, the resulted bacterial colonies were tiny and were streaked on LB plate for further culture. After purification, the colonies were yellow, circular, smooth-margined, and two independent representative isolates CM-11 and CM-12 were used for further validation experiments. The electron microscope analysis showed that the pathogen was rod-shaped, with a length of 1.34 ± 0.22 μm and a width of 0.54 ± 0.06 μm (N=50), and had a single terminal flagellum. The gram staining of the two isolates was negative. Moreover, the tested strains were positive for catalase but negative for oxidase and were able to utilize D-glucose, L-arabinose, and D-mannitol. Morphological, physiological, and biochemical characteristics of both isolates were consistent with those of spp. To verify the species identity of the bacterial pathogens, genomic DNA of isolates CM-11 and CM-12 was extracted and several conserved genes were amplified and sequenced, including the 16S rRNA gene with primers 27F/1492R (GenBank MW187499 and MW187500), rpoB gene with primers V4/LAPS27 (MW201910 and MW446819), and gyrB gene with primers gyrBBAUP2/APrU (MW187501 and MW187502) (Mulet et al. 2010). In the BLAST analysis, the 16S rRNA sequences showed a 99% similarity to that of strains TH19 (LC026009), AA21 (MG571765). The rpoB and gyrB sequences showed high similarity (> 98%) to strains FDAARGOS_657. The phylogenetic tree analysis of rpoB and gyrB genes further verified that the two isolates CM-11 and CM-12 were most closely related to species. Consequently, the two pathogenic isolates CM-11 and CM-12 were identified as . Both strains of CM-11 and CM-12 were tested to accomplish Koch's postulates. Young branches of muskmelons (cultivar Yugu, 10 days after pollination) were chosen as the material for inoculation. Ten healthy detached branches were placed in 15 ml tubes by submerging the cutting wound in 5 ml of the bacterial suspension (10 CFU/ml). Ten additional branches were implemented with sterilized distilled water as a negative control. The inoculated branches were placed in a plastic box containing moistened paper at 28°C. Rotting symptoms appeared within 5 days after infection, while the control samples remained healthy. Bacteria were re-isolated from diseased tissues, and the 16S rRNA gene sequences of the isolates showed the same as those from the original pathogen. Panicle blight and grain discoloration disease caused by on rice has been described in China (Hou et al. 2020). It's also recently found that caused center blackening disease on muskmelon fruit in Korea (Choi et al. 2019). This study indicated that it was a causative agent of stem and leaf rot disease during the field growth period. To the best of our knowledge, this is the first report of causing muskmelon stem rot in China.
PubMed: 33507101
DOI: 10.1094/PDIS-01-21-0100-PDN -
Journal of Experimental Botany Nov 2022Soil bacteria promote plant growth and protect against environmental stresses, but the mechanisms involved remain poorly characterized, particularly when there is no...
Soil bacteria promote plant growth and protect against environmental stresses, but the mechanisms involved remain poorly characterized, particularly when there is no direct contact between the roots and bacteria. Here, we explored the effects of Pseudomonas oryzihabitans PGP01 on the root system architecture (RSA) in Arabidopsis thaliana seedlings. Significant increases in lateral root (LR) density were observed when seedlings were grown in the presence of P. oryzihabitans, as well as an increased abundance of transcripts associated with altered nutrient transport and phytohormone responses. However, no bacterial transcripts were detected on the root samples by RNAseq analysis, demonstrating that the bacteria do not colonize the roots. Separating the agar containing bacteria from the seedlings prevented the bacteria-induced changes in RSA. Bacteria-induced changes in RSA were absent from mutants defective in ethylene response factor (ERF109), glutathione synthesis (pad2-1, cad2-1, and rax1-1) and in strigolactone synthesis (max3-9 and max4-1) or signalling (max2-3). However, the P. oryzihabitans-induced changes in RSA were similar in the low ascorbate mutants (vtc2-1and vtc2-2) to the wild-type controls. Taken together, these results demonstrate the importance of non-volatile signals and redox mechanisms in the root architecture regulation that occurs following long-distance perception of P. oryzihabitans.
Topics: Arabidopsis; Plant Roots; Pseudomonas; Seedlings; Oxidation-Reduction; Gene Expression Regulation, Plant; Transcription Factors; Arabidopsis Proteins
PubMed: 36001048
DOI: 10.1093/jxb/erac346 -
Genome Announcements Jun 2016We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa The...
We report the genome sequences of two double-stranded DNA siphoviruses, POR1 infective for Pseudomonas oryzihabitans and PAE1 infective for Pseudomonas aeruginosa The phage POR1 genome showed no nucleotide sequence homology to any other DNA phage sequence in the GenBank database, while phage PAE1 displayed synteny to P. aeruginosa phages M6, MP1412, and YuA.
PubMed: 27313312
DOI: 10.1128/genomeA.01515-15 -
Journal of Bone and Joint Infection 2016is a saprophytic gram-negative microorganism usually found in damp environments, only occasionally responsible for human pathology. Infection mainly occurs in...
is a saprophytic gram-negative microorganism usually found in damp environments, only occasionally responsible for human pathology. Infection mainly occurs in malnourished, immunocompromised individuals with indwelling catheters. There is no previous published record of infection after joint arthroplasty. To enhance the literature, in this article we report a patient with a infected total hip arthroplasty, and discuss the diagnosis and management of this unusual infection.
PubMed: 28529854
DOI: 10.7150/jbji.16967 -
Plant Disease Nov 2023China ranks first in the production and harvest area of walnut ( L.) worldwide. Currently, the poor health and low yield of walnut caused by pathogen infection is of...
China ranks first in the production and harvest area of walnut ( L.) worldwide. Currently, the poor health and low yield of walnut caused by pathogen infection is of concern. In 2022, severe walnut leaf spot disease was observed on the seedlings of four walnut nurseries (0.08 to 0.23 ha) in Liaocheng, Shandong, China, with an average incidence of 48.6% (from 34.6% to 65.3% on the cultivar Xiangling). From August to October, leaf spots mainly appeared on the edges of the leaflets, and occasionally between veins. The lesions were initially soft and rotten, and then light brown, round to semi-circular. Subsequently, the adjacent lesions fused, and the edges of the leaflets and entire leaflets showed symptoms of browning and wilting. For pathogen isolation, five leaflets with representative symptoms from one of the nurseries were collected and wiped three times with sterile absorbent cotton dipped in 75% alcohol and washed with distilled water. Leaflet pieces at the junction of the lesion and healthy tissues were removed, crushed in a sterile mortar, and soaked in a small amount of distilled water for 10 min. The diseased tissue suspension was streaked on a nutrient agar medium (NA) with a sterile inoculation ring and incubated at 28°C for 24 to 72 h. The bacterial colonies obtained were further cultured on NA. The purified colonies were uniform in shape, round, and yellow, with a raised, shiny surface and smooth margin. The isolates were Gram-negative, and the electron microscope analysis showed that the pathogens were short rods (0.35 to 0.52 × 0.90 to 1.24 μm, average = 0.44 ± 0.05 × 1.08 ± 0.11 μm, n = 25). For bacterial species identification, a single-colony culture was subjected to genomic DNA extraction and gene amplification and sequencing of 16S rRNA, D, and B. The universal primers 27F/1492R (Lane 1991) were used to amplify the 16S rRNA gene and the specific primers 70F/70R and UP-1E/APrU (Yamamoto et al. 2000) were used to amplify the D and genes, respectively. In the BLAST analysis, the 16S rRNA sequence (GenBank OR195734) of the isolate shared 99% similarity (1409/1410 bp) with strain IAM 1568T (AM262973.1), and the D (OR709708) and B (OR709707) sequences showed >98% identity to D (707/717 bp; FN554494.1) and B (787/801 bp; FN554210.1) of strain LMG 7040T. Based on the above results, the isolated bacterium was identified as . For the pathogenicity test, healthy leaflets from 10 two-year-old potted walnut seedlings (cv. Xiangling) were used as inoculation materials. The leaflets were punctured with a sterile inoculation needle of 0.4 mm, and three small holes on each leaflet at an interval of about 5 mm were covered with a piece of sterile cotton. A bacterial suspension (1 ml) at 10 CFU/ml was spread onto the cotton, and wrapped with plastic film for 24 h. Water was used as a negative control. The inoculations were performed five times. Plants were grown outdoors at a daily average temperature of 22°C with relative humidity over 45%. Two days after inoculation, the disease began to develop in the leaflets with similar symptoms to those observed in the field. In contrast, control plants remained healthy and symptomless. Bacteria were reisolated from the inoculated walnut plants, and the morphology and 16S rRNA gene sequences of the isolates were the same as those of the original strains. Since it was discovered as an opportunistic human pathogenic bacterium in the 1970s (Keikha et al. 2019), has also been shown to cause certain plant diseases, such as panicle blight and grain discoloration on rice (Hou et al. 2020), fruit black rot on prickly ash (Liu et al. 2021), and stem and leaf rot on muskmelon (Li et al. 2021). As far as we know, this is the first report of causing walnut leaf spot disease in China. Leaf spot caused by may be a threat to walnut cultivation, and this report of its occurrence is the first step in determining potential spread and effective control measures.
PubMed: 37923975
DOI: 10.1094/PDIS-08-23-1634-PDN -
The Journal of Foot and Ankle Surgery :... 2023Leclercia adecarboxylata and Pseudomonas oryzihabitans are two bacteria rarely seen in human infections. We present an unusual case of a patient who developed a... (Review)
Review
Leclercia adecarboxylata and Pseudomonas oryzihabitans are two bacteria rarely seen in human infections. We present an unusual case of a patient who developed a localized infection with these bacteria after repair of a ruptured Achilles tendon. We also present a review of the literature regarding infection with these bacteria within the lower extremity.
Topics: Humans; Enterobacteriaceae Infections; Anti-Bacterial Agents; Achilles Tendon
PubMed: 36868930
DOI: 10.1053/j.jfas.2022.11.004 -
International Journal of Systematic and... Feb 2020Two yellow-pigmented, Gram-stain-negative and rod-shaped bacterial strains, designated as RY24 and ZYY160, were isolated from rice. Results of phylogenetic analysis...
Two yellow-pigmented, Gram-stain-negative and rod-shaped bacterial strains, designated as RY24 and ZYY160, were isolated from rice. Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strains RY24 and ZYY160 belonged to the genus , and the 16S rRNA gene sequence similarity was 100 % The DNA homology between the two strains was 99.7 %. The 16S rRNA and gene sequences of the two strains showed highest similarity values to CGMCC 1.3392 and DSM 15758 (sharing 99.31 and 94.34 %, respectively). The major fatty acids of two strains were identified as summed feature 8 (Cω7 and/or Cω6), C and summed feature 3 (Cω7 and/or Cω6), and the major respiratory quinone was identified as ubiquinone Q-9, which are typical chemotaxonomic features of members of the genus . The genomic DNA G+C contents of strains RY24 and ZYY160 were determined to be 64.25 and 64.21 mol%, respectively. The DNA-DNA relatedness and average nucleotide identity values between the two strains and their closely related type strains were below 36 and 90 %, which supported that RY24 and ZYY160 represent a novel species in the genus . Phylogenetic and chemotaxonomic evidence, together with phenotypic characteristics, showed that the two isolates constitute a novel species of the genus . The type strain is RY24 (JCM 33201=ACCC 61555), for which the name sp. nov. is proposed.
Topics: Bacterial Typing Techniques; Base Composition; China; DNA, Bacterial; Fatty Acids; Genes, Bacterial; Nucleic Acid Hybridization; Oryza; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Ubiquinone
PubMed: 31751195
DOI: 10.1099/ijsem.0.003852 -
International Journal of Women's... Jun 2022
PubMed: 35619673
DOI: 10.1097/JW9.0000000000000024 -
AMB Express May 2022Psychrotrophic Pseudomonas is one of the significant microbes that lead to putrefaction in chilled meat. One of the biggest problems in the detection of Pseudomonas is...
Psychrotrophic Pseudomonas is one of the significant microbes that lead to putrefaction in chilled meat. One of the biggest problems in the detection of Pseudomonas is that several species are seemingly identical. Currently, antibiotic resistance is one of the most significant challenges facing the world's health and food security. Therefore, this study was designed to apply an accurate technique for eliminating the identification discrepancy of Pseudomonas species and to study their resistance against various antimicrobials. A total of 320 chicken meat specimens were cultivated, and the isolated bacteria' were phenotypically recognized. Protein analysis was carried out for cultured isolates via Microflex LT. The resistance of Pseudomonas isolates was recorded through Vitek® 2 AST-GN83 cards. Overall, 69 samples were identified as Pseudomonas spp. and included 18 Pseudomonas lundensis (P. lundensis), 16 Pseudomonas fragi (P. fragi), 13 Pseudomonas oryzihabitans (P. oryzihabitans), 10 Pseudomonas stutzeri (P. stutzeri), 5 Pseudomonas fluorescens (P. fluorescens), 4 Pseudomonas putida (P. putida), and 3 Pseudomonas aeruginosa (P. aeruginosa) isolates. Microflex LT identified all Pseudomonas isolates (100%) correctly with a score value ≥ 2.00. PCA positively discriminated the identified isolates into various groups. The antimicrobial resistance levels against Pseudomonas isolates were 81.16% for nitrofurantoin, 71% for ampicillin and ampicillin/sulbactam, 65.22% for cefuroxime and ceftriaxone, 55% for aztreonam, and 49.28% for ciprofloxacin. The susceptibilities were 100% for cefotaxime, 98.55% for ceftazidime, 94.20% for each piperacillin/tazobactam and cefepime, 91.3% for cefazolin. In conclusion, chicken meat was found to be contaminated with different Pseudomonas spp., with high incidence rates of P. lundensis. Microflex LT is a potent tool for distinguishing Pseudomonads at the species level.
PubMed: 35532863
DOI: 10.1186/s13568-022-01390-1 -
International Journal of Food... Feb 2019This is the first report of bacterial center blackening in muskmelon fruit caused by Pseudomonas oryzihabitans, which is known as an opportunistic pathogen of humans and...
This is the first report of bacterial center blackening in muskmelon fruit caused by Pseudomonas oryzihabitans, which is known as an opportunistic pathogen of humans and warm-blooded animals. The aim of this study was to investigate the microbiological characteristics of this infection. Bacterial center blackening, which can cause aversion in consumers, was observed in muskmelon fruit in South Korea in the fall of 2017. Symptoms included severe black pigmentation in the pulp surrounding the seeds inside muskmelon fruit. Dark brown pigmentation and gram-negative, non-spore-forming, rod-shaped pseudomonads were consistently recovered from the black pigmented pulp tissue of muskmelons. The symptoms after artificial inoculation were the same as those of the natural infection, while the control fruit exhibited no symptoms of infection. Using pathogenicity tests, analytical profile index (API) tests, whole-cell matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene and gyrB region sequencing, the dominant species was identified as P. oryzihabitans. The recent outbreak indicates that P. oryzihabitans poses a potential threat to the global production and transportation of muskmelon as well as food safety.
Topics: DNA Gyrase; Food Microbiology; Food Safety; Fruit; Pigmentation; Pseudomonas; RNA, Ribosomal, 16S; Republic of Korea; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 30419473
DOI: 10.1016/j.ijfoodmicro.2018.11.003