Competition for nutrient niches within the apple blossom microbiota antagonizes the initiation of fire blight infection.

Changes in the plant microbiota composition are intimately associated with the health of the plant, but factors controlling the microbial community in flowers are poorly understood. In this study, we used apple flowers and fire blight as a model system to investigate the effects of floral microbiota and microbial competition on disease development and suppression. To compare changes in microbial flora with the RNA expression patterns of plants, the flower samples were collected in three different flowering stages (Bud, Popcorn, and Full-bloom). Using advanced sequencing technology, we analyzed the data and conducted both in vitro and in vivo experiments to validate our findings. Our results show that the Erwinia amylovora use arabinogalactan, which is secreted on the flowers, for early colonization of apple flowers. Pantoea agglomerans was more competitive for arabinogalactan than E. amylovora. Additionally, P. agglomerans suppressed the expression of virulence factors of E. amylovora by using arabinose, which is a major component of arabinogalactan, which induces virulence gene expression. The present data provide new insights into developing control strategies for diverse plant diseases, including fire blight, by highlighting the importance of nutrients in disease development or suppression.

Clinical and pathological features of cerebrospinal meningitis caused by Pantoea agglomerans : a case report.

BACKGROUND: Pantoea agglomerans (P. agglomerans) is a gram-negative bacterium that is commonly isolated from plant surfaces, seeds, and the environment. As an opportunistic pathogen, it can cause blood, urinary and soft tissue infections in immunocompromised patients. In central nervous system, P. agglomerans infection has been report in children and immune-compromised patients, however, infection by such bacterium in nontraumatized immune competent adults has not been reported. Here, we report a case of P. agglomerans cerebrospinal meningitis accompanied by positive anti-myeloperoxidase (MPO) antibody in a 49-year-old female who has a history of black fungus planting. CASE PRESENTATION: The patient manifested with repeated fever, headache, generalized muscle pain, and neurological defects. Cerebrospinal fluid (CSF) tests revealed a moderately elevated number of polymorphonuclear leukocytes (50-193 × 106/L), low glucose levels (0.54-2.44 mmo1/L), and extremely high protein content (2.42-25.42 g/L). Blood tests showed positive anti-myeloperoxidase antibodies lasting for 1.5 year before turning negative. Spine MRI showed thickening and enhancement of the whole spinal meninges. CSF metagenomic next-generation sequencing (mNGS) revealed 75,189 specific DNA reads of P. agglomerans. The patient underwent spinal laminectomy due to meningeal adhesions. Pathological results revealed fibrous tissue proliferation, inflammatory infiltration with focal necrosis and calcification in the dura mater. The patient was successfully treated with sufficient antibiotics at 1-year follow-up. CONCLUSIONS: People should be alert to CNS infections caused by P. agglomerans which presented with relatively mild clinical symptoms at onset, especially for those who contucts relevant agricultural and forestry work. The CSF characterization of P. agglomerans meningitis is elevated multiple nuclei white blood cells, significantly reduced glucose content, and markedly increased protein level which may be related to the secondary spinal membrane adhesions.

An underdog under the mandible: Pantoea agglomerans abscess of the submandibular region- a case report.

BACKGROUND: Pantoea agglomerans is a gram negative, aerobic/facultative anaerobic, rod shaped bacilli commonly isolated from plants, soil, food and faeces.(1) It is a rare cause of opportunistic infections in humans acquired mainly via two major routes being, wound infection or hospital acquired. CASE REPORT: Here, we encountered a landmark, first of its kind, head and neck manifestation of a cervical soft tissue abscess with Pantoea agglomerans being the miscreant. The patient presented with complaints of a left sided neck swelling, which was radiologically suggestive of a cold abscess, however clinical suscpicion encouraged us to perform an incision and drainage, culture of which revealed this notorious phytogenic bacterium. DISCUSSION: Commonly encountered Pantoea infected cases documented in literature have shown a clinical picture of endophthalmitis, acute unilateral dacryocystitis, periostitis, endocarditis, osteomyelitis and a tumour like muscle cyst of the thigh with many of them eventually leading to septicemia while a few also resolved with targeted antibiotics.(2) Remarkably, no ENT or head and neck presentations have been reported in literature till date. History of trauma by brushing against a mango tree was confirmed retrospectively, which was found to be the missing piece of the puzzle.

Evaluation of the in vitro effects of concentrations of antibiotics on three Enterobacteriaceae isolates.

Due to the misuse and overuse of antibiotics, bacteria are now exposed to sub-minimum inhibitory concentrations (sub-MICs) of antibiotics in various environments. In recent years, exposure of bacteria to sub-MICs of antibiotics has led to the widespread emergence of antibiotic-resistant bacteria. In this study, three bacterial species from the Enterobacteriaceae family (Raoultella ornithinolytica, Pantoea agglomerans and Klebsiella quasivariicola) were isolated from water. The antibiotic susceptibility of these bacteria to 16 antibiotics was then investigated. The effects of sub-MICs of four selected antibiotics (kanamycin, chloramphenicol, meropenem, and ciprofloxacin) on the growth, biofilm formation, surface polysaccharide production, siderophore production, morphology, and expression of the translational/transcriptional regulatory transformer gene rfaH of these bacteria were analysed. The MICs of kanamycin, chloramphenicol, meropenem, and ciprofloxacin were determined to be 1, 2, 0.03 and 0.03 µg/mL for R. ornithinolytica; 0.6, 6, 0.03 and 0.05 µg/mL for P. agglomerans; and 2, 5, 0.04 and 0.2 µg/mL for K. quasivariicola. The growth kinetics and biofilm formation ability decreased for all three isolates at sub-MICs. The surface polysaccharides of R. ornithinolytica and P. agglomerans increased at sub-MICs. There was no significant change in the siderophore activities of the bacterial isolates, with the exception of MIC/2 meropenem in R. ornithinolytica and MIC/2 kanamycin in K. quasivariicola. It was observed that the sub-MICs of meropenem and ciprofloxacin caused significant changes in bacterial morphology. In addition, the expression of rfaH in R. ornithinolytica and K. quasivariicola increased with the sub-MICs of the selected antibiotics.

Complete Genome Sequence of Pantoea agglomerans CHTF15, a Walnut Pathogen.

The phytopathogen Pantoea agglomerans belongs to the Bacteria, Proteobacteria, Gammaproteobacteria, Enterobacterales, Erwiniaceae in species classification. It causes disease symptoms in many plants such as corn, banana, and walnut. This study aimed to report the complete genome of P. agglomerans CHTF15, which represents the first whole-genome sequence of an isolate from diseased walnut leaves. The total length of the assembled genome was 4,820,607 bp, with an average GC content of 55.3%, including a circular chromosome and three circular plasmids, two of which were previously unreported sequences and one was announced previously. The CHTF15 genome helps understand the pathogenic mechanism of this important plant pathogen and provides an important theoretical basis for disease epidemic and field control. [Formula: see text] The author(s) have dedicated the work to the public domain under the Creative Commons CC0 "No Rights Reserved" license by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law, 2023.

Use of Pantoea agglomerans ASB05 as a biocontrol agent to inhibit the growth of Salmonella enterica on intact cantaloupe melons.

AIMS: To identify biocontrol agents to prevent the growth of Salmonella serotype Enterica on cantaloupe melons during the pre- and postharvest periods. METHODS AND RESULTS: We created a produce-associated bacterial library containing 8736 isolates and screened it using an in-vitro fluorescence inhibition assay to identify bacteria that inhibit the growth of S. Enterica. One isolate, Pantoea agglomerans ASB05, was able to grow, persist, and inhibit the growth of S. Enterica on intact cantaloupe melons under simulated pre- and postharvest conditions. We also demonstrated that the growth inhibition of S. Enterica by P. agglomerans ASB05 was due to the production of a phenazine type antibiotic. CONCLUSIONS: Pantoea agglomerans ASB05 is an effective biocontrol agent for the prevention of S. Enterica growth on intact cantaloupe melons in both the pre- and postharvest environments.

Contribution of Native Plasmids of Pantoea vagans C9-1 to Epiphytic Fitness and Fire Blight Management on Apple and Pear Flowers and Fruits.

Pantoea vagans C9-1 (C9-1) is a biological control bacterium that is applied to apple and pear trees during bloom for suppression of fire blight, caused by Erwinia amylovora. Strain C9-1 has three megaplasmids: pPag1, pPag2, and pPag3. Prior bioinformatic studies predicted these megaplasmids have a role in environmental fitness and/or biocontrol efficacy. Plasmid pPag3 is part of the large Pantoea plasmid (LPP-1) group that is present in all Pantoea spp. and has been hypothesized to contribute to environmental colonization and persistence, while pPag2 is less common. We assessed fitness of C9-1 derivatives cured of pPag2 and/or pPag3 on pear and apple flowers and fruit in experimental orchards. We also assessed the ability of a C9-1 derivative lacking pPag3 to reduce populations of E. amylovora on flowers and disease incidence. Previously, we determined that tolerance to stresses imposed in vitro was compromised in derivatives of C9-1 lacking pPag2 and/or pPag3; however, in this study, the loss of pPag2 and/or pPag3 did not consistently reduce the fitness of C9-1 on flowers in orchards. Over the summer, pPag3 contributed to survival of C9-1 on developing apple and pear fruit in two of five trials, whereas loss of pPag2 did not significantly affect survival of C9-1. We also found that loss of pPag3 did not affect C9-1's ability to reduce E. amylovora populations or fire blight incidence on apple flowers. Our findings partially support prior hypotheses that LPP-1 in Pantoea species contributes to persistence on plant surfaces but questions whether LPP-1 facilitates host colonization.

First Report of Pantoea agglomerans Causing Leaf Blight on Schisandra chinensis in China.

Schisandra chinensis (Turcz.) Baill is a perennial liana, which is widely cultivated and used in China. In August 2022, Schisandra chinensis leaves with small light brown spots were found on plants growing in Fusong (127°28'E, 42°33'N) of China. There was 15% disease incidence and 50% disease severity of Schisandra chinensis in 2-ha fields of S. chinensis. As the disease progressed, the spots become darker and form round or irregular concentric circles. Leaves with brown spot symptoms were collected from the field. Leaf pieces (5 mm × 5 mm) were excised from lesion margins, surface disinfected with 75% ethanol for 1 min, followed by 1.5% sodium hypochlorite for 3 min, and incubated on Luria Bertani (LB) solid medium at 28°C for 24 hours. Eight cultures were isolated, and representative single colony (XWWZH) was selected from the pure cultures according to colony characteristics for observation The purified colonies were round, yellow, and slimy, cells were straight rod-shaped (0.40 to 0.52 × 1.12 to 1.69 µm) were observed. The isolate was Gram negative. It was positive for methyl red reaction, lysine decarboxylase reaction, gelatin hydrolysis reactionand sucrose utilization. It was negative for indole reaction and produced H2S. The bacterium was preliminarily identified as Pantoea agglomerans based on morphological and biochemical tests (Baird et al. 2007). The 16S rDNA and a portion of rpoB of strain XWWZH were amplified and sequenced. The sequences were submitted to GenBank. (Accession OP763753 and OQ813505, respectively). Phylogenetic trees were constructed based on the 16S rDNA and rpoB gene sequences. The sequences of strain XWWZH clustered with strains P. agglomerans deposited in GenBank. The pathogenicity was verified with non-wounded S. chinensis seedlings by punching holes with sterile needles and injecting a solution of 1 × 108 CFU/ml solution. Sterile ddH2O was injected in the control experiment. The inoculated seedlings were incubated in a greenhouse at 25°C with a relative humidity of 65 to 70%. Five to eight days after inoculation, inoculated leaves, exhibited symptoms which were morphologically identical to those of the originally infected leaves whereas control plants remained asymptomatic. The pathogenicity assays were repeated twice with the same results. The re-isolated pathogen had the same morphology and DNA sequences as the original isolate obtained from the field samples, completing Koch's postulates. Strains of P. agglomerans have been reported to severely infect many plants (Ren et al.2008; Lee et al. 2010; Yang et al. 2011; Guo et al. 2019; Gao et al, 2022), but to the best of our knowledge, this is the first report of a strain of P. agglomerans causing leaf blight on Schisandra chinensis in China. The identification of leaf blight caused by P. agglomerans will enable farmers to prevent and manage it ahead of time to reduce losses.

Three Phages One Host: Isolation and Characterization of Pantoea agglomerans Phages from a Grasshopper Specimen.

The bacterial genus Pantoea comprises species found in a variety of different environmental sources. Pantoea spp. are often recovered from plant material and are capable of both benefitting the plants and acting like phytopathogens. Some species of Pantoea (including P. agglomerans) are considered opportunistic human pathogens capable of causing various infections in immunocompromised subjects. In this study, a strain of P. agglomerans (identified by 16S rRNA gene sequencing) was isolated from a dead specimen of an unidentified Latvian grasshopper species. The retrieved strain of P. agglomerans was then used as a host for the potential retrieval of phages from the same source material. After rounds of plaque purification and propagation, three high-titer lysates corresponding to putatively distinct phages were acquired. Transmission electron microscopy revealed that one of the phages was a myophage with an unusual morphology, while the two others were typical podophages. Whole-genome sequencing (WGS) was performed for each of these isolated phages. Genome de novo assembly and subsequent functional annotation confirmed that three different strictly lytic phages were isolated. Elaborate genomic characterization of the acquired phages was performed to elucidate their place within the so-far-uncovered phage diversity.

Timber-colonizing gram-negative bacteria as potential causative agents of respiratory diseases in woodworkers.

OCCURRENCE: Gram-negative bacteria occur commonly in the inner tissues of stored coniferous and deciduous timber, showing a marked variation in numbers. The greatest maximal numbers are found in the sapwood of coniferous timber. The common constituents of the Gram-negative biota are potentially pathogenic species of Enterobacteriaceae family of the genera Rahnella, Pantoea, Enterobacter, and Klebsiella. The air of wood-processing facilities is polluted with the wood-borne Gram-negative bacteria and produced by them endotoxin, as demonstrated worldwide by numerous studies. EFFECTS: There are three potential pathways of the pathogenic impact of wood-borne Gram-negative bacteria on exposed woodworkers: allergic, immunotoxic, and infectious. Allergic impact has been underestimated for a long time with relation to Gram-negative bacteria. Hopefully, the recent demonstration of the first documented case of hypersensitivity pneumonitis (HP) in woodworkers caused by Pantoea agglomerans which developed in extremely large quantities in birch sapwood, would speed up finding of new wood-related cases of HP caused by Gram-negative bacteria. The second pathway is associated with endotoxin, exerting strong immunotoxic (excessively immunostimulative) action. It has been demonstrated that endotoxin is released into wood dust in the form of nano-sized microvesicles, by peeling off the outer membrane of bacteria. Endotoxin microvesicles are easily inhaled by humans together with dust because of small dimensions and aerodynamic shape. Afterwards, they cause a nonspecific activation of lung macrophages, which release numerous inflammatory mediators causing an inflammatory lung reaction, chest tightness, fever, gas exchange disorders, and bronchospasm, without radiographic changes. The resulting disease is known as "Organic Dust Toxic Syndrome" or "toxic pneumonitis." The potential third pathway of pathogenic impact is infection. The suspected species is Klebsiella pneumoniae that may occur commonly in wood dust; however, until now this pathway has not been confirmed. CONCLUSION: Summarizing, Gram-negative bacteria-inhabiting timber should be considered, besides filamentous fungi and actinobacteria, as important risk factors of occupational disease in woodworkers that could be either HP with allergenic background or toxic pneumonitis elicited by endotoxin.

First report of bacterial wilt disease caused by Pantoea agglomerans on the ornamental perennial Oxalis articulata in China.

Oxalis articulata is now widely cultivated in China as an ornamental species, and thus found in abundance in agricultural farms, gardens, and lawns. In December 2021, some severely infected Oxalis articulata were observed at many places at Zhejiang Normal University (29°8'4″N, 119°37'54″E) in Jinhua City, Zhejiang Province, China. Yellow was first observed on the margin of the leaves, leading to light brown and wilting at a later stage. To identify the pathogen, symptomatic leaves were collected and cut into small pieces, surface disinfected in 1% sodium hypochlorite solution for 3 min, followed by 75% alcohol for 0.5 min, then rinsed in sterile distilled water thrice. Then they were transferred onto Luria-Bertani medium and incubated at 28°C for 3 days. The colonies were round, yellow, viscous and smooth, which was consistent with the characteristics of Pantoea agglomerans (Li et al. 2020; Zhang et al. 2022). The bacteria tested gram-negative, negative for indole test and Voges-Proskauer reaction, and positive for methyl red reaction, lysine decarboxylase and ornithine decarboxylase. In addition, the bacteria can utilize D-xylose, sorbitol, adonitol, and glucose, but can't utilize raffinose, urea, and Simmons. Meanwhile the bacteria can not produce H2S, and can not produce gas from D-glucose as well. These results of physiological and biochemical characteristics were consistent with those of Pantoea agglomerans (Gavini et al. 1989). To identify the strain, the 16S rDNA gene fragment was amplified by polymerase chain reaction (PCR) using universal primers 8F and 1510R, and sequenced. The BLAST results indicated that the 16S rDNA sequence of the strain OAPB-1, deposited under GenBank accession LC709256, showed 99.93% (1376/1377) and 99.49% (1370/1377) identity to the corresponding sequence of Pantoea agglomerans FC2948 (MH532498.1) and the type strain Pantoea agglomerans DSM 3493 (AJ233423) respectively. The Neighbor-Joining phylogenetic tree generated using MEGA11 indicated that it formed a clade with the other P. agglomerans. Furthermore, the phylogenetic analysis based on sequences of housekeeping genes (atpD, rpoB and infB; GenBank accession LC722492 to LC722494) showed the same result. Based on the above results, the strain OAPB-1 from Zhejiang was identified as P.agglomerans. To test the Koch's postulates, bacterial suspensions (2×108CFU/mL) were injected into the middle of healthy leaves of mature plants with sterile water as a control. Then the plants were placed at 28°C in a light incubator with 12-h-light/12-h-dark photoperiod and approximately 60% humidity. Leaves in the inoculated group showed symptoms similar to those observed on the naturally infected leaves, while leaves in the control group showed no symptoms. The pathogen was reisolated from inoculated leaves, and its morphological characteristics and molecular identification results were consistent with those of the original isolate. P. agglomerans is a bacterium associated with plants, and also infects humans and animals (Dutkiewicz et al. 2016). In China, it has been reported to infect many kinds of plants (Fan et al. 2022; Guo et al. 2020; Han et al. 2020; Li et al. 2020; She et al. 2019; Zhang et al. 2022). As far as we know, this is the first report of P. agglomerans causing bacterial wilt on Oxalis articulata in China. These results further expand the range of plants that can be infected by P. agglomerans, and help to establish an effective control strategy against the disease.

First report of leaf blight caused by Pantoea agglomerans on wheat in China.

Wheat (Triticum aestivum L.) is the main grain crop in Ningxia Hui Autonomous Region, China. A new leaf blight disease of wheat was observed in many wheat fields in Yinchuan City and Wuzhong City of Ningxia during 2020-2021. The average disease incidence of the cultivar Ningchun 50 was 5 to 15%, and there appeared the evident disease symptoms from the heading stage, then the symptoms got more serious until the mature stage. The tips of the leaves were chlorotic and turned bright yellow at the early stage of the disease. Later on, the yellow leaf spots were further spread from the tip to the petiole, and the yellow-colored necrotic lesions emerged, resulted in withering and death of leaves (e-Xtra 1, a-d). To isolate and identify the pathogenic agent, diseased leaves were cut into 0.5 cm × 0.5 cm small pieces, and sterilized in 5% NaOCl solution for 5 min, and were rinsed three times in sterile water, then crushed with tweezers in 2 mL sterilized water and streaked three times onto Nutrient Agar (NA) medium. and 15 single colonies which had the same colony morphology were obtained. Of the 15 colonies, 3 (named WH1, Cx1 and HJ1) were randomly selected for further morphological, biochemical and molecular characterization. The resulting bacterial colonies were incubated at 29±1°C in the dark for 3 days, colony morphology was raised, mucoid texture, round, and smooth with entire margin; the color of these colonies was white at the beginning and turned yellow later. These bacteria were rod-shaped gram-negative cells with peritrichous flagella. Based on the physiological and biochemical assay results (e-Xtra 2), the three strains were initially identified as Pantoea agglomerans (Wang, D H., et al. 2021; Wang, J J., et al. 2021). 16S rDNA and gyrB of the three strains were amplified and sequenced by ABI3730XL sequencer in GENEWIZ (Suzhou, China). The sequences of 16S rDNA and gyrB of these strains were submitted to GenBank with the accession numbers ON428446, ON428461 and ON428462 for 16S rDNA; ON461799, ON461801, ON461803 for gyrB. 16S rDNA and gyrB sequences homology analysis showed that the three strains had the highest homology which were over 99.5% with the sequences of the reported P. agglomerans (e-Xtra 1, g) . A phylogenetic analysis based on 16S rDNA and gyrB gene sequences was performed using the MEGA6.0 proximity method, and the results of the phylogenetic tree showed that strains Cx1, WH1 and HJ1 clustered on the same clade with the reported P. agglomerans strains (e-Xtra 1, h-j). Thus, Cx1, WH1 and HJ1 were identified as P. agglomerans. Pathogenicity test was performed to complete Koch's postulates, Ningchun 50 was planted in pots, four-week-old healthy wheat seedlings were inoculated with 107 CFU/mL bacterial suspension using two inoculation methods: 1) Leaf surface was poked with disposable syringe needle, and 50 µL of suspension was injected into each of the pinholes (Suraj, S., et al. 2020); 2) Leaf was cut at 45° at the lower 2-3 cm of the leaf tip with scissors dipped in the bacterial suspension. Wheat leaves inoculated with sterile distilled water were regarded as controls. The inoculated wheat was cultivated in a greenhouse (temperature 28 ± 2°C, humidity 40 ± 2%) and covered in transparent polyethylene bags at first 96 h. Symptoms appeared at 3 days after inoculation, and after 7 days, the acupunctured wheat leaves turned chlorotic and yellow around the pinholes and some were necrotic; the leaf-cutting wheat turned yellow and necrotic from the clipping point to the leaf base; the acupunctured and cut leaves totally died after 15 days, and all of the control leaves were healthy (e-Xtra 1, e-f). Subsequently, pathogens were reisolated from inoculated leaves, and identified as P. agglomerans according to molecular identification described above. To our knowledge, this is the first report of leaf blight disease of wheat caused by Pantoea agglomerans globally as well as in China. Identifying the cause of the disease will support efforts for its future control and management.

Isolation and identification of Pantoea agglomerans from the inflated bag with dried hop pellets stored under a modified atmosphere.

AIMS: Isolation, characterization and identification of possible microbial contaminant(s) in the inflated foil bag containing hop pellets packed and stored in a modified atmosphere. METHODS AND RESULTS: Package gas of the inflated foil bag containing hop pellets was analysed by gas chromatography. Compared with the reference modified atmosphere, containing about 16 vol.% of CO2 , the inflated bag atmosphere contained 53 vol.% CO2 , suggesting possible microbial contamination. Therefore, several standard and mineral media, with added hop pellets or hop infusion, were used for cultivation at different temperatures under an anaerobic atmosphere. Cultivation in mineral medium with hop pellets yielded a bacterial isolate that was identified by MALDI-TOF mass spectrometry and verified by partial 16S rRNA gene analysis as Pantoea agglomerans, a known plant epiphyte. CONCLUSIONS: A novel strain of P. agglomerans (designed as DBM 3696) was found to be suspicious of causing inflation of the foil bag containing dried hop pellets packed in modified atmosphere. SIGNIFICANCE AND IMPACT OF THE STUDY: This study suggests that P. agglomerans, probably hop epiphyte, could cause sporadic inflation of bags with hop pellets packed in modified atmosphere causing logistical problems during bags transport.

Pantoea Bacteriophage vB_PagS_MED16-A Siphovirus Containing a 2'-Deoxy-7-amido-7-deazaguanosine-Modified DNA.

A novel siphovirus, vB_PagS_MED16 (MED16) was isolated in Lithuania using Pantoea agglomerans strain BSL for the phage propagation. The double-stranded DNA genome of MED16 (46,103 bp) contains 73 predicted open reading frames (ORFs) encoding proteins, but no tRNA. Our comparative sequence analysis revealed that 26 of these ORFs code for unique proteins that have no reliable identity when compared to database entries. Based on phylogenetic analysis, MED16 represents a new genus with siphovirus morphology. In total, 35 MED16 ORFs were given a putative functional annotation, including those coding for the proteins responsible for virion morphogenesis, phage-host interactions, and DNA metabolism. In addition, a gene encoding a preQ0 DNA deoxyribosyltransferase (DpdA) is present in the genome of MED16 and the LC-MS/MS analysis indicates 2'-deoxy-7-amido-7-deazaguanosine (dADG)-modified phage DNA, which, to our knowledge, has never been experimentally validated in genomes of Pantoea phages. Thus, the data presented in this study provide new information on Pantoea-infecting viruses and offer novel insights into the diversity of DNA modifications in bacteriophages.

Hydrogen Peroxide Metabolism in Interkingdom Interaction Between Bacteria and Wheat Seeds and Seedlings.

In endophytes, the abundance of genes coding for enzymes processing reactive oxygen species (ROS), including hydrogen peroxide (H2O2), argues for a crucial role of ROS metabolism in plant-microbe interaction for plant colonization. Here, we studied H2O2 metabolism of bread wheat (Triticum aestivum 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 H2O2 than untreated seeds. Using a culture-dependent approach, Pantoea and Pseudomonas genera were the most abundant epiphytes of dry untreated seeds. Incubating intact seedlings from hot steam-treated seeds with Pantoea strains triggered H2O2 production, whereas Pseudomonas strains dampened H2O2 levels, attributable to higher catalase activities. The genus Pantoea was much less represented among seedling endophytes than genus Pseudomonas, with other endophytic genera, including Bacillus and Paenibacillus, 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.

Distribution of Pantoea agglomerans isolates and molecular detection of blaPER-1 ESßL gene: A statistical study.

THE PURPOSE: to study the distribution of Pantoea agglomerans (P. agglomerans) statistically and the presence of blaPER-1 type ESßL in the clinical and environmental isolates. METHODS: During a period of 2014-2015, 895 blood specimens and 438 hospital environmental samples were collected from one children's hospital in Baghdad city. The results of statistical analysis showed there was no relationship between the infection with P. agglomerans and the sex, while there was a relationship between the infection with the P. agglomerans and the place of residence and also the age of patients. RESULT: A total of 23 P. agglomerans were isolated during the study, out of 23 isolates, 13 (56.52%) and 10 (43.48%) were isolated from blood specimens and from hospital environment. All 23 isolates had 100% sensitivity rate to Imipenem and the highest resistant rate was (95.65%) to Ampicillin. Out of 23 P. agglomerans, 14 (60.87%) isolates were positive ESßL producing by the screening test. CONCLUSION: The result of molecular screening of the gene blaPER-1 showed the presence of this gene only in phenotypically ESBL producing isolates, while all negative ESßL producing isolates don't harboring blaPER-1 gene. Out of 14 positive ESßL producing P. agglomerans isolates, 5 (35.71%) were harboring blaPER-1 gene and 9 (64.29%) of positive ESßL producing isolates were don't harboring blaPER-1 gene (significant difference at ≤0.05).

Subchronic (90-day) toxicity assessment of Somacy-FP100, a lipopolysaccharide-containing fermented wheat flour extract from Pantoea agglomerans.

Pantoea agglomerans is a Gram-negative bacterium that is ubiquitous in the environment, colonizing animals, humans, and numerous plants, including cotton and wheat. A lipopolysaccharide-containing fermented wheat flour extract from P. agglomerans (Somacy-FP100) is proposed for use as a food ingredient for individuals seeking foods for healthy aging. Previously published genotoxicity studies with Somacy-FP100 reported its lack of genotoxicity in vitro, but a subchronic toxicity study has not yet been performed. Therefore, to demonstrate the safety of Somacy-FP100 for use as a food ingredient, a 90-day oral (gavage) toxicity study in rats was conducted. Male and female Han Wistar rats were administered vehicle (control) or Somacy-FP100 at 500, 1500, or 4500 mg/kg body weight/day at a dose volume of 10 mL/kg body weight, for at least 90 days. No test article-related adverse clinical signs or effects on body weight, food consumption, or clinical pathology were observed, and there were no macroscopic or microscopic findings related to the test article. Therefore, 4500 mg/kg body weight/day (the highest dose tested and highest feasible dose) was established as the no-observed-adverse-effect level. This absence of subchronic toxicity, in addition to the previously reported lack of genotoxicity, demonstrates the safety of Somacy-FP100 for use as a food ingredient.

Photobiomodulation by dual-wavelength low-power laser effects on infected pressure ulcers.

The aim of this study was to evaluate the effects of photobiomodulation (PBM) by dual-wavelength low-power lasers on the healing and bacterial bioburden of pressure ulcer (PU) models. Twenty-five male Swiss mice were divided into five equal groups. Ischemia reperfusion cycles were employed to cause PU formation by the external application of magnetic plates. Immediately after wounding, a suspension of Pantoea agglomerans was applied at the base of all the wounds of the infected groups, using a calibrated pipette. PBM (simultaneous emission at 660 and 808 nm, 142.8 J/cm2, in continuous wave emission mode) was applied to the PUs for 14 sessions. The animals were euthanized 14 days after PU induction, and their tissues were analyzed for wound contraction and reepithelialization, epidermis thickness, bacterial survival, and IL-1ß and IL-10 mRNA level evaluations. The PU areas appeared larger in the mice from the infected groups than in those in the laser group 4 days after PU induction and presented incomplete reepithelialization 14 days after PU induction. However, the PBM accelerated the wound healing in the infected + laser group compared with the infected group 11 and 14 days following the PU induction. The infected and irradiated PUs exhibited a thinner neo-epidermis than those in the infected group, and the bacterial survival decreased in the laser group; the relative expression IL-1ß mRNA levels demonstrated an increasing tendency while the relative expression IL-10 mRNA levels demonstrated a decreasing tendency in the infected + laser and laser groups. These results suggest that PBM improves healing by killing or inhibiting bacteria in PUs as well as by accelerating the wound healing, resulting in tissue repair.

Bioreactor production of 2,3-butanediol by Pantoea agglomerans using soybean hull acid hydrolysate as substrate.

Production of 2,3-butanediol (2,3-BD) by Pantoea agglomerans strain BL1 was investigated using soybean hull hydrolysate as substrate in batch reactors. The cultivation media consisted of a mixture of xylose, arabinose, and glucose, obtained from the hemicellulosic fraction of the soybean hull biomass. We evaluated the influence of oxygen supply, pH control, and media supplementation on the growth kinetics of the microorganism and on 2,3-BD production. P. agglomerans BL1 was able to simultaneously metabolize all three monosaccharides present in the broth, with average conversions of 75% after 48 h of cultivation. The influence of aeration conditions employed demonstrated the mixed acid pathway of 2,3-BD formation by enterobacteria. Under fully aerated conditions (2 vvm of air), up to 14.02 g L-1 of 2.3-BD in 12 h of cultivation were produced, corresponding to yields of 0.53 g g-1 and a productivity of 1.17 g L-1 h-1, the best results achieved. These results suggest the production potential of 2,3-BD by P. agglomerans BL1, which has been recently isolated from an environmental consortium. The present work proposes a solution for the usage of the hemicellulosic fraction of agroindustry biomasses, carbohydrates whose utilization are not commonly addressed in bioprocess.

Molecular Profile of Phage Infection: A Novel Approach for the Characterization of Erwinia Phages through qPCR.

Due to the emergence of antibiotic resistance, phage-mediated biocontrol has become an attractive alternative for pathogen management in agriculture. While the infection characteristics of many phages can be adequately described using plaque assays and optical density, the results from phages of the apple pathogen Erwinia amylovora have low reproducibility with these techniques. Using quantitative real-time PCR (qPCR), the stage of the lytic cycle was determined through a combination of chloroform-based sampling, centrifugation, and DNase treatment. Monitoring the transition of phage genomes through the lytic cycle generates a molecular profile from which phage infection characteristics such as adsorption rate and burst size can be determined. To our knowledge, this is the first report of qPCR being used to determine these infection parameters. The characteristics of four different genera of Erwinia phages were determined. The phage ΦEa461A1 was able to adsorb at a rate up to 6.6 times faster than ΦEa35-70 and ΦEa9-2. The low enrichment titer of ΦEa92 was shown to be due to the absence of lysis. The ΦEa461A1 and ΦEa214 phages had the highest productivity, with burst sizes of 57 virions in 38 min and 185 virions in 98 min, respectively, suggesting these genera would make stronger candidates for the phage-mediated biocontrol of E. amylovora.