-
Plant Disease Jul 2022Tobacco (Nicotiana tabacum) is an economically important crop, and its productivity is challenged due to pathogen infection. In 2020 and 2021, a previously...
Tobacco (Nicotiana tabacum) is an economically important crop, and its productivity is challenged due to pathogen infection. In 2020 and 2021, a previously uncharacterized disease was observed on field grown tobacco (Variety NC102) in Zhucheng City, Shandong Province, China (119°7'14" E, 36°0'58" N), where tobacco has been grown for decades. The disease can be found throughout the growth period of tobacco and mainly occurred from fast growing period (about 13-16 leaves) to leaf maturity stage. In severely diseased areas, the incidence rate can reach 100%. The symptoms first began as chlorotic water stain like small spots, then the spots merged into larger irregular necrotic maculae around the chlorotic halos. Small pieces of symptomatic leaves from 10 different infected plants were collected for pathogen isolation. The small pieces of discolored leaves were surface sterilized with 75% ethanol for 40s and washed with sterile water for three times. The sterilized leaves were ground with a glass rod with 1mL sterile water, and 100 μL suspensions were spread on nutrient agar medium then incubated at 28oC for 48 hours. Yellow round colonies with undulating edges were showed up on nutrient agar medium 48 hours later. Three isolates were randomly picked up from each of the 10 plates for subsequent analysis. After purification and culture on nutrient agar plate, the 16S rRNA gene of the 30 isolates were amplified with primers 27F and 1492R and the amplicons were sequenced and analyzed by sequence alignment. The sequence alignment results showed that the 16S rRNA nucleotide identity of the 30 isolates were 100%. One typical isolate named ZC5 was selected for subsequent analysis, and the resulting 16S rRNA sequence was deposited at GenBank, NCBI under accession OK092624. The 16S rRNA sequence identity with those of P. psychrotolerans strain K3-2 (KY882083) and M3-1 (KY882120) were 100%, respectively. The phenotypic analysis by Biolog Gen Ⅲ indicated that the bacterial isolate (ZC5) showed highest similarity (98.3%) with strain Pseudomonas oryzihabitans. P. oryzihabitans and P. psychrotolerans have a high degree of homology in the phylogenetic relationship based on the phylogenetic analysis of three concatenated sequences of gyrB, rpoB and rpoD genes (Mulet et al. 2010). The gyrB (ON462356), rpoB (ON462355), rpoD (ON462357) gene of isolate ZC5were also amplified and sequenced by using primers gyrB-For/gyrB-Rev, rpoB-For/rpoB-Rev and rpoD-For/rpoD-Rev (Hauser et al. 2004), respectively. While P. psychrotolerans and P. oryzihabitans form the same clade in phylogenies, strains of P. psychrotolerans do form a unique sub-clade. Isolate ZC5 clustered more closely with the type strain of P. psychrotolerans LMG 21977 in the phylogenetic tree. Therefore, based on the concatenated sequences of three genes (gyrB, rpoB and rpoD), the isolate ZC5 was confirmed as P. psychrotolerans. Based on morphological, Biolog characteristics and phylogenetic analysis, the isolate was identified as P. psychrotolerans. The tobacco plants at fast growing stage were selected for pathogenicity tests. Pathogenicity tests were conducted by injecting 10 μL bacterial suspension (108cfu/mL) of ZC5 into tobacco leaves with a syringe. Sterile water was inoculated into the tobacco leaves in the same way as the control. Six plants were selected for pathogenicity tests each time and five leaves of each tobacco plant were inoculated, and the tests were repeated three times. To simulate disease conditions in the natural environment, the inoculated plants were moved outdoors. The average temperature was 32°C during the day and 20°C at night. To maintain humidity, the tobacco leaves were sprayed with water every two days. Symptoms appeared on the pathogen inoculated leaves seven days after inoculation, whereas the control treatment remained symptomless. The pathogens were reisolated from diseased leaves and identified as P. psychrotolerans based on morphological, molecular and phylogenetic analysis, which fulfilled Koch's postulates. To our knowledge, this is the first report of tobacco bacterial leaf spot caused by P. psychrotolerans.
PubMed: 35852908
DOI: 10.1094/PDIS-05-22-1069-PDN -
Microorganisms Apr 2023The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a...
The aim of this work was to assess the natural microbiota of packed fresh-cut apples during refrigerated storage. Two different films were tested for the package, a biodegradable (PLA) film and a conventional and commercial one (OPP). Two antioxidant additives were applied, a natural olive pomace extract and the commercial ascorbic acid used by the industries. The results revealed lower bacteria counts in samples with olive pomace extract and PLA films than in those with ascorbic acid and OPP films after 5 and 12 days of storage. These findings suggest that the use of such natural extracts as additives in fruits could delay the growth of mesophilic bacteria. The characterization and identification of the bacterial isolates from fresh-cut apple samples showed that the most prevalent species were , , , , , spp., and spp. Furthermore, an increase in the microbial diversity during the storage time at refrigerated temperatures was observed, except for the sample treated with olive pomace extract and packaged in OPP film. The highest microbial diversity was found for samples with ascorbic acid as an additive. This could indicate a negative effect of ascorbic acid on the microbial inhibition of apple slices. The natural olive pomace extract demonstrated potential as an antimicrobial additive for fresh-cut apples.
PubMed: 37317130
DOI: 10.3390/microorganisms11051157 -
Infection & Chemotherapy Mar 2014Pseudomonas oryzihabitans is frequently found in various sites within hospital settings, including sink drains and respiratory therapy equipment. Although it rarely...
Pseudomonas oryzihabitans is frequently found in various sites within hospital settings, including sink drains and respiratory therapy equipment. Although it rarely causes human infections, P. oryzihabitans has recently been considered a potential nosocomial pathogen, especially in immunocompromised hosts. We report our experience of an outbreak of P. oryzihabitans pseudobacteremia, presumably due to faulty aseptic preparation of a saline gauze canister.
PubMed: 24693469
DOI: 10.3947/ic.2014.46.1.42 -
Standards in Genomic Sciences 2017We report here the draft genome sequences of eight bacterial strains of the genera , and . These isolates were obtained from aerosol sampling of bathrooms of five...
Draft genome sequences of eight bacteria isolated from the indoor environment: strain H36, strain H65, strain H62, strain H69, sp. strain H83, strain H39, sp. strain H53, and strain H72.
We report here the draft genome sequences of eight bacterial strains of the genera , and . These isolates were obtained from aerosol sampling of bathrooms of five residences in the San Francisco Bay area. Taxonomic classifications as well as the genome sequence and gene annotation of the isolates are described. As part of the "Built Environment Reference Genome" project, these isolates and associated genome data provide valuable resources for studying the microbiology of the built environment.
PubMed: 28163826
DOI: 10.1186/s40793-017-0223-9 -
Molecular Plant-microbe Interactions :... Feb 2020In endophytes, the abundance of genes coding for enzymes processing reactive oxygen species (ROS), including hydrogen peroxide (HO), argues for a crucial role of ROS...
In endophytes, the abundance of genes coding for enzymes processing reactive oxygen species (ROS), including hydrogen peroxide (HO), argues for a crucial role of ROS metabolism in plant-microbe interaction for plant colonization. Here, we studied HO metabolism of bread wheat ( L.) seeds and their microbiota during germination and early seedling growth, the most vulnerable stages in the plant life cycle. Treatment with hot steam diminished the seed microbiota, and these seeds produced less extracellular HO than untreated seeds. Using a culture-dependent approach, and genera were the most abundant epiphytes of dry untreated seeds. Incubating intact seedlings from hot steam-treated seeds with strains triggered HO production, whereas strains dampened HO levels, attributable to higher catalase activities. The genus was much less represented among seedling endophytes than genus , with other endophytic genera, including and , also possessing high catalase activities. Overall, our results show that certain bacteria of the seed microbiota are able to modulate the extracellular redox environment during germination and early seedling growth, and high catalase activity is proposed as a key trait of seed endophytes.
Topics: Germination; Hydrogen Peroxide; Oxidation-Reduction; Seedlings; Seeds; Triticum
PubMed: 31631769
DOI: 10.1094/MPMI-09-19-0248-R -
Environmental Health Insights 2020The 21st century has seen a wide range of diseases resulting from zoonotic infections, of which bacterial infections have led to outbreaks of food-borne diseases.
BACKGROUND
The 21st century has seen a wide range of diseases resulting from zoonotic infections, of which bacterial infections have led to outbreaks of food-borne diseases.
AIM
The study looks at bacterial pathogen carriage by farm rats and their antimicrobial susceptibility, with the view of providing insights for antimicrobial surveillance.
METHOD
Farm rats of species where randomly collected alive from farms in Al-Ahsa using food baits. They were anaesthetize with urethane within 4 h of collection and were unconscious for the collection of samples. Basic bacteriological culturing methods were used for culturing of bacterial isolates on selective media while the Vitek 2 compact automated system (BioMerieux, Marcy L'Etoile, France) was used for bacteria identification and antimicrobial susceptibility test. Obtained data were analysed using chi-square and paired -test with significant difference between sensitive and resistance to antimicrobial susceptibility taken at < .05.
RESULTS
Isolated Gramme-negative pathogenic bacteria included strains of , strains of , and For the Gramme-positive bacteria, 4 strains of were encountered. Other Gramme-positive bacteria were coagulase-negative species (CoNS) as well as . There was a 100% resistance to the penicillins and a high resistance to imipenem (71%) by the isolates. Resistance was also high against the β-lactams by the Gramme-positive bacteria isolates. For the Gramme-negative bacteria, there was a higher than 50% resistance by the isolates against the following antibiotics: ampicillin (78%), amoxicillin/clavulanic acid (67%), cefotaxime (77%), ceftazidime (67%), cefepime (78%), norfloxacin (67%), nitrofurantoin (67%), and trimethoprim/sulfamethoxazole (78%).
CONCLUSION
The results showed high antimicrobial resistance that will need monitoring for control of spread from farm rats to humans.
PubMed: 32874093
DOI: 10.1177/1178630220942240 -
Journal of Clinical Microbiology Jan 1989A case of peritonitis caused by Flavimonas oryzihabitans (Pseudomonas oryzihabitans; CDC group VE-2) in a patient on continuous ambulatory peritoneal dialysis is...
A case of peritonitis caused by Flavimonas oryzihabitans (Pseudomonas oryzihabitans; CDC group VE-2) in a patient on continuous ambulatory peritoneal dialysis is reported. This is the seventh case of infection caused by this organism reported in the English literature and the third reported case of continuous ambulatory peritoneal dialysis-related peritonitis caused by this organism; it is the first case of infection of any kind caused by this organism in England.
Topics: Aged; Humans; Male; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Pseudomonas; Pseudomonas Infections
PubMed: 2913032
DOI: 10.1128/jcm.27.1.217-218.1989 -
Hippokratia Jan 2012A Pseudomonas oryzihabitans clinical isolate was recovered from a blood sample. The patient, a 14-year-old-adolescent underwent parathyroidectomy due to secondary...
A Pseudomonas oryzihabitans clinical isolate was recovered from a blood sample. The patient, a 14-year-old-adolescent underwent parathyroidectomy due to secondary hyperparathyroidism. The patient had been going peritoneal dialysis because of chronic renal failure. According to the susceptibility testing conducted with phenotypic methods the microorganism was sensitive to the vast majority of the antibiotics. The isolation of this rare species of Pseudomonas combined with the patient's medical history stimulated as to focus on the causes of the bacteremia, which was non catheter-related.
PubMed: 23930068
DOI: No ID Found -
Journal of Clinical Microbiology Jun 1988Pseudomonas luteola (CDC group Ve-1) and Pseudomonas oryzihabitans (CDC group Ve-2) were both isolated from the same blood culture of a 5-month-old infant, 8 days after...
Pseudomonas luteola (CDC group Ve-1) and Pseudomonas oryzihabitans (CDC group Ve-2) were both isolated from the same blood culture of a 5-month-old infant, 8 days after open-heart surgery. He quickly responded to appropriate antibiotics. Carbon substrate assimilation tests and fatty acid analysis clearly differentiated these two rarely pathogenic organisms.
Topics: Humans; Infant; Male; Postoperative Complications; Pseudomonas; Pseudomonas Infections; Sepsis
PubMed: 3384937
DOI: 10.1128/jcm.26.6.1241-1243.1988 -
Clinical Microbiology and Infection :... Sep 2002
Review
Topics: Adult; Female; Glomerulonephritis, IGA; Humans; Male; Middle Aged; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Pseudomonas Infections
PubMed: 12427223
DOI: 10.1046/j.1469-0691.2002.00447.x