Pantoea Species Research Articles

Pantoea species causing early onset neonatal sepsis: a case report

IntroductionPantoea agglomerans is a plant pathogen which very rarely causes an opportunistic infection. Human beings are usually infected by thorn prick injuries or by contaminated parenteral fluids. Pantoea agglomerans has been reported as a cause of neonatal sepsis very rarely and to the best of our knowledge this is the first reported case from India.Case presentationA 4-day-old Asian baby boy from the rural area of Odisha, India, was admitted to our neonatal intensive care unit when he presented with fever, tachypnea and chest retraction. Pantoea species were isolated from his blood culture.ConclusionsHe was treated successfully with meropenem administered intravenously and other supportive measures. Early detection and proper management may cause a favorable outcome.

Effects of postharvest onion curing parameters on bulb rot caused by Pantoea agglomerans, Pantoea ananatis and Pantoea allii in storage

Crop loss of onion bulbs during storage carries an exceptionally high economic impact because a large portion of the production expenses has been expended before storage. Because of this, it is important to define practices that can reduce onion bulb losses caused by storage rots. This study investigates the impact of various curing parameters on disease development resulting from infection by Pantoea agglomerans, P. ananatis and P. allii on onion bulb cultivars Vaquero and Redwing, during storage. Overall, both the incidence and mean rot severity were similar amongst the bulbs under comparable conditions regardless of the species of Pantoea inoculated, although a significant difference was detected between the two onion bulb cultivars. In addition, a significant reduction of storage rot was observed when curing temperatures were ≤35°C. At temperatures >35°C, a shorter curing duration (2 days vs 14 days) decreased the severity of bulb rot due to Pantoea. This increased understanding of the inter‐relationships between the parameters used for curing, and the incidence and severity of bulb rot caused by Pantoea helps provide guidance towards using the curing process as a means to reduce the level of damage resulting from post‐harvest storage rot.

Examining phylogenetic relationships of Erwinia and Pantoea species using whole genome sequence data.

The genera Erwinia and Pantoea contain species that are devastating plant pathogens, non-pathogen epiphytes, and opportunistic human pathogens. However, some controversies persist in the taxonomic classification of these two closely related genera. The phylogenomic analysis of these two genera was investigated via a comprehensive analysis of 25 Erwinia genomes and 23 Pantoea genomes. Single-copy orthologs could be extracted from the Erwinia/Pantoea core-genome to reconstruct the Erwinia/Pantoea phylogeny. This tree has strong bootstrap support for almost all branches. We also estimated the in silico DNA-DNA hybridization (isDDH) and the average nucleotide identity (ANI) values between each genome; strains from the same species showed ANI values ≥96% and isDDH values >70%. These data confirm that whole genome sequence data provides a powerful tool to resolve the complex taxonomic questions of Erwinia/Pantoea, e.g. Pantoea agglomerans 299R was not clustered into a single group with other P. agglomerans strains, and the ANI values and isDDH values between them were <91% and around 43.8%, respectively. These data indicate P. agglomerans 299R should not be classified into the P. agglomerans species. In addition, another strain (Pantoea sp. At_9b) was identified that may represent a novel Pantoea species. We also evaluated the performance of six commonly used housekeeping genes (atpD, carA, gyrB, infB, recA, and rpoB) in phylogenetic inference. A single gene was not enough to obtain a reliable species tree, and it was necessary to use the multilocus sequence analysis of the six marker genes to recover the Erwinia/Pantoea phylogeny.

Pantoea intestinalis sp. nov., isolated from the human gut.

A novel bacterial strain, 29Y89BT, was isolated from a faecal sample of a healthy human subject. Cells were Gram-stain-negative, motile, non-spore-forming and rod-shaped. Strain 29Y89BT formed cream-coloured colonies 2 mm in diameter on trypticase soy agar and showed optimum growth at 35 °C. Strain 29Y89BT showed highest 16S rRNA gene sequence similarity to Pantoea gaviniae A18/07T (98.4 %) followed by Pantoea calida 1400/07T (97.2 %). Multi-locus sequence analysis using atpD (ATP synthase β subunit), gyrB (DNA gyrase), infB (initiation translation factor 2) and rpoB (RNA polymerase β subunit) genes also supported the result of 16S rRNA gene sequence based phylogeny. Strain 29Y89BT showed 62 and 40.7 % DNA-DNA relatedness with P. calida DSM 22759T and P. gaviniae DSM 22758T. Strain 29Y89BT contained C17 : 0 cyclo, C19 : 0 cyclo ω8c, C16 : 0, C14 : 0 and C12 : 0 as predominant fatty acids. In addition, strain 29Y89BT showed physiological and phenotypic differences from its closest relatives P. gaviniae DSM 22758T and P. calida DSM 22759T. The polar lipid profile mainly comprised phospholipids. The DNA G+C content was 59.1 mol%. Thus, based on the findings of the current study, strain 29Y89BT showed clear delineations from its closest relatives P. gaviniae DSM 22758T and P. calida DSM 22759T, and is thus considered to represent a novel species of the genus Pantoea, for which the name Pantoea intestinalis sp. nov. is proposed. The type strain is 29Y89BT ( = DSM 28113T = MCC 2554T).

Characterization of Plant Growth Promoting Rhizobacteria Isolated from Chickpea (Cicer arietinum)

Aims: To isolate bacterial strains from chickpea rhizospheric soil and nodules, to characterize and identify potential bacterial strains by using 16S rRNA gene sequencing. Place and Duration of Study: Department of Soil Science & SWC, PMAS, Arid Agriculture University, Rawalpindi Pakistan between July 2010 and July 2011. Background: Plant growth promoting rhizobacteria are being preferred nowadays as inoculants for influencing crops via multiple direct or indirect mechanisms but screening to find out the effective PGPR strains is one of the crucial steps. This research is aimed at keeping in view their potential for phosphate solubilization, indole acetic acid and ammonia production. Methodology: Extensive survey was carried out in Pothwar (District, Rawalpindi, Attock and Original Research Article Ali et al.; BMRJ, 6(1): 32-40, 2015; Article no.BMRJ.2015.056 33 Chakwal) for collection of chickpea rhizospheric soil and root nodules. The isolation of rhizospheric soil bacteria was performed by using dilution plate technique while the root nodules bacteria were isolated on yeast extract mannitol agar supplemented with congo red. Ten bacterial strains designated as AM-1 to AM10 were isolated, purified and characterized for phosphate solubilization, indole acetic acid (IAA) and ammonia production. These bacterial strains were identified as belonging to species of Bacillus, Enterobacter, Pseudomonas, Rhizobium, Sphingobacterium, Pantoea and Chryseobacterium. All bacterial strains solubilized phosphate and produced IAA. Two bacterial strains AM-5 (Sphingobacterium canadense) and AM-4 (Rhizobium pusense) solubilized the maximum amount of phosphate i.e. 273.84 μg ml -1 and 262.83 μg ml -1 respectively with a significant pH drop from 7 to 2.67. These strains proved positive for ammonia production. Six most potential and identified strains were selected on the basis of plant growth promoting activities. Conclusion: AM-4 (Rhizobium pusense) and AM-5 (Sphingobacterium canadense) are efficient strains and there is a need of inoculation experiments under control and field conditions to use these stains as biofertilizer to enhance the growth and productivity of the chickpea.

Endophytic bacteria in cacti native to a Brazilian semi-arid region

To identify endophytic bacteria in Brazilian cacti, and to evaluate the effects of those bacteria on the growth of Cereus jamacaru seedlings and phosphate solubilization in vitro. Samples of roots and stems of C. jamacaru and Melocactus zehntneri were collected from the Aiuaba ecological Station in Brazilian semi-arid region. Bacterial isolates were cultured in semi-solid N-free media and grown in Pikoskaya’s and GL media phosphate solubilizing. In seedling assays, strains of Rhizobium (CAC 01), Enterobacter (CAC 02 and CAC 11), Pseudomonas (CAC 03) and Burkholderia (CAC 07 and CAC 10) were tested. Culturable endophytic bacteria were observed in all samples from cacti, but the populations were low. Representatives of eight groups were identified based on partial sequences of 16S rDNA and were related to Rhizobium, Burkholderia, Enterobacter, Pseudomonas, and Pantoea species. The colonization of seedlings with endophytic bacteria was observed, but biomass accumulation did not show a significant increase. All strains were able to grow on solid Pikoskaya’s medium. The bacterial strains didn’t increase significantly the cactus biomass during 6 months of cultivation, but showing potential phosphate solubilizing activity.

Transcriptome of the invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Heteroptera: Pentatomidae).

Halyomorpha halys (Stål) (Heteroptera: Pentatomidae), the brown marmorated stink bug, is an invasive agricultural and nuisance pest rapidly expanding its incidence in North America. This voracious pest poses a significant threat to rural and urban agriculture, especially to specialty crops such as apples, grapes and ornamentals, as well as staple crops including soybean and corn. The object of this study was to generate transcript sequence resources for H. halys. RNA-seq libraries derived from distinct developmental stages and sexes were sequenced and assembled into 248,569 putatively unique transcripts (PUTs). PUTs were segmented into three disjoint tiers of varying reliability, with 4,794 classified as gold tier (highest quality), 16,878 as silver, and 14,357 as bronze. The gold-tier PUTs associated with 2,580 distinct non-redundant protein sequences from the NCBI NR database—1,785 of these (69%) mapped to annotated UniProtKB database proteins, from which 1,273 unique Pfam families and 459 unique Molecular Function GO terms were encountered. Of the silver tier's 6,527 PUTs associated with unique proteins, 4,193 mapped to UniProtKB (64%), from which 1,941 and 640 unique Pfam and Molecular Function GO terms were extracted. H. halys PUTs related to important life processes like immunity, endocrinology, reproduction, development, behavior, neurotransmission, neurotoxicity, olfaction, and small RNA pathways were validated through quantitative Real-Time PCR (qRT-PCR) for differential expression during distinct life stages (eggs, 2nd instar nymphs, 4th instar nymphs, female adults, male adults). PUTs similar to hypothetical proteins identified in symbiont microbes, including Pantoea and Nosema species, were more abundantly expressed in adults versus nymphs. These comprehensive H. halys transcriptomic resources can be utilized to aid development of novel control methodologies to disrupt life processes; to conduct reverse genetic screens to determine host gene function; and to design environmentally unobtrusive means to control host populations or target specific H. halys life stages, such as molecular biopesticides.

Single-molecule sequencing to track plasmid diversity of hospital-associated carbapenemase-producing Enterobacteriaceae.

Public health officials have raised concerns that plasmid transfer between Enterobacteriaceae species may spread resistance to carbapenems, an antibiotic class of last resort, thereby rendering common health care-associated infections nearly impossible to treat. To determine the diversity of carbapenemase-encoding plasmids and assess their mobility among bacterial species, we performed comprehensive surveillance and genomic sequencing of carbapenem-resistant Enterobacteriaceae in the National Institutes of Health (NIH) Clinical Center patient population and hospital environment. We isolated a repertoire of carbapenemase-encoding Enterobacteriaceae, including multiple strains of Klebsiella pneumoniae, Klebsiella oxytoca, Escherichia coli, Enterobacter cloacae, Citrobacter freundii, and Pantoea species. Long-read genome sequencing with full end-to-end assembly revealed that these organisms carry the carbapenem resistance genes on a wide array of plasmids. K. pneumoniae and E. cloacae isolated simultaneously from a single patient harbored two different carbapenemase-encoding plasmids, indicating that plasmid transfer between organisms was unlikely within this patient. We did, however, find evidence of horizontal transfer of carbapenemase-encoding plasmids between K. pneumoniae, E. cloacae, and C. freundii in the hospital environment. Our data, including full plasmid identification, challenge assumptions about horizontal gene transfer events within patients and identify possible connections between patients and the hospital environment. In addition, we identified a new carbapenemase-encoding plasmid of potentially high clinical impact carried by K. pneumoniae, E. coli, E. cloacae, and Pantoea species, in unrelated patients and in the hospital environment.

Identification of a Pantoea biosynthetic cluster that directs the synthesis of an antimicrobial natural product.

Fire Blight is a destructive disease of apple and pear caused by the enteric bacterial pathogen, Erwinia amylovora. E. amylovora initiates infection by colonizing the stigmata of apple and pear trees, and entering the plants through natural openings. Epiphytic populations of the related enteric bacterium, Pantoea, reduce the incidence of disease through competition and antibiotic production. In this study, we identify an antibiotic from Pantoea ananatis BRT175, which is effective against E. amylovora and select species of Pantoea. We used transposon mutagenesis to create a mutant library, screened approximately 5,000 mutants for loss of antibiotic production, and recovered 29 mutants. Sequencing of the transposon insertion sites of these mutants revealed multiple independent disruptions of an 8.2 kb cluster consisting of seven genes, which appear to be coregulated. An analysis of the distribution of this cluster revealed that it was not present in any other of our 115 Pantoea isolates, or in any of the fully sequenced Pantoea genomes, and is most closely related to antibiotic biosynthetic clusters found in three different species of Pseudomonas. This identification of this biosynthetic cluster highlights the diversity of natural products produced by Pantoea.

Detection and quantification by PCR assay of the biocontrol agent Pantoea agglomerans CPA-2 on apples

The registration of biological control agents requires the development of monitoring systems to detect and quantify the agent in the environment. Pantoea agglomerans CPA-2 is an effective biocontrol agent for postharvest diseases of citrus and pome fruits. The monitoring of CPA-2 in postharvest semi-commercial trials was evaluated by Rodac impression plates and the colonies isolated were confirmed by conventional PCR using the SCAR primers PAGA1 and PAGB1. Samples were taken from different surfaces that had contact with CPA-2, the surrounding environment and working clothes worn by handlers. Moreover, population dynamics of the strain CPA-2 were determined on apple surfaces using both the classical plating technique and real-time quantitative PCR (qPCR). A qPCR assay using a 3′-minor groove-binding (MGB) probe was developed for the specific detection and quantification of P. agglomerans strain CPA-2. Based on the nucleotide sequence of a SCAR fragment of CPA-2, one primer set and TaqMan MGB probe were designed. The primers SP2-F/SP2-R and the TaqMan MGB probe showed a specific detection of strain CPA-2 on apple surfaces, which was verified tested against purified DNA from 17 strains of P. agglomerans, 4 related Pantoea species, and 21 bacterial strains from other genera isolated from whole and also freshly-cut fruit and vegetables. The detection level was approximately 103 cells per reaction, and the standard curve was linear within a range of 5log units. Results from semi-commercial trials showed that CPA-2 had a low impact. The maximum persistence of P. agglomerans CPA-2 was not longer than 5days in plastic boxes stored at 0°C. Significant differences in CPA-2 population level dynamics were observed in results obtained by qPCR and dilution plating. These differences may indicate the presence of non-degraded DNA from non-viable cells. In conclusion, qPCR is a novel potential tool to quickly and specifically monitor recent surface colonisation by CPA-2 populations on apple surfaces during large-scale experiments that could ensure efficient and successful treatments.

Microbiota from &amp;lt;i&amp;gt;Helix aspersa&amp;lt;/i&amp;gt; M&amp;#252;ller in Barcelona Area (Spain)

In recent decades snail consumption has been increasing throughout Europe. The Heliciculture meets this need and gets snail farms, in order to get consistent production in the shortest possible time. The research provided, has a main objective to establish the microbiota of Helix aspersa Müller, both from healthy animals, and individuals with gastrointestinal processes. The samples selected for the study were feces obtained from snails collected in both breeding farms as field snails. In the case, farm animals were selected apparently form healthy individuals and others were with signs of gastrointestinal process study. Aliquots of each sample were plated on a range of culture media and incubated under different conditions of temperature and respiration. From the results we can note that the healthy snails (farmed or free-living) have been isolated and identified mostly, as strains belonging to the genera Pediococcus, Lactobacillus and Lactococcus and five strains of yeasts of the genera Candida and Cryptococcus. Individuals suffering from gastrointestinal disturbances processes have been isolated in high proportion species of Klebsiella, Pantoea, Citrobacter and Enterobacter. The results obtained indicate that the snails with health problems reduce the presence of strains of Lactobacillus and Lactococcus in favor of increasing and/or establishing colonization by strains of Enterobacteriaceae.

Microbiology of Root Crops, Edible Corms, Tubers, Bulbs, and Rhizomes: An Endobacteriological Study

A variety of root crops, corms, tubers, and rhizomes commonly eaten and available in public markets were tested for the presence and identification of bacteria in their inner flesh. Bacteria were grown on agar slants and identified by DNA sequence analysis. Among foods tested were various radishes, onions, shallots, leeks, yams, parsnips, turnips, carrots, potatoes, ginger, garlic, parsnips, beets, horse radish, kohl-rabi, and less well-known crops such as yucca/cassava, celery root/celeriac, jicama, taro, lotus, water chestnut, Chinese/Korean yam (nagaimo), edible burdock (golden gobo), batata, root parsley, and yautia (malanga). Examples of the bacterial genera identified were, among others, species of Arthrobacter, Pantoea, Bacillus, Pseudomonas, Staphylococcus, Microbacterium, Stenotrophomonas, Rahnella, Rhodococcus, Paenibacillus, Oerskovia, Gordonia, and Leclercia. While these species are probably present in harmless numbers, their presence may indicate that the inner flesh of these crops should be studied more extensively. Crops that are boiled, fried, baked or otherwise cooked may obviously not be a health hazard, but some of these vegetables are eaten raw or only lightly cooked and may possibly merit further study for possible health implications. Tubers that were very proficient in producing new shoots, such as potato and the Chinese/Korean yam (nagaimo) were found to contain inner flesh free of bacteria and seemed to be resistant to rotting; this may imply that these tubers have antimicrobial properties.

An In-depth Analysis of a Multilocus Phylogeny Identifies leuS As a Reliable Phylogenetic Marker for the Genus Pantoea.

Partial sequences of six core genes (fusA, gyrB, leuS, pyrG, rlpB, and rpoB) of 37 strains of Pantoea species were analyzed in order to obtain a comprehensive view regarding the phylogenetic relationships within the Pantoea genus and compare tree topologies to identify gene(s) for reliable species and subspecies differentiation. All genes used in this study were effective at species-level delineation, but the internal nodes represented conflicting common ancestors in fusA- and pyrG-based phylogenies. Concatenated gene phylogeny gave the expected DNA relatedness, underscoring the significance of a multilocus sequence analysis. Pairwise comparison of topological distances and percent similarities indicated a significant differential influence of individual genes on the concatenated tree topology. leuS- and fusA-inferred phylogenies exhibited, respectively, the lowest (4) and highest (52) topological distances to the concatenated tree. These correlated well with high (96.3%) and low (64.4%) percent similarities of leuS- and fusA-inferred tree topologies to the concatenated tree, respectively. We conclude that the concatenated tree topology is strongly influenced by the gene with the highest number of polymorphic and non-synonymous sites in the absence of significant recombination events.

Physiologic and metabolic characterization of a new marine isolate (BM39) of Pantoea sp. producing high levels of exopolysaccharide

BackgroundMarine environments are the widest fonts of biodiversity representing a resource of both unexploited or unknown microorganisms and new substances having potential applications. Among microbial products, exopolysaccharides (EPS) have many physiological functions and practical applications. Since EPS production by many bacteria is too scarce for practical use and only few species are known for their high levels of production, the search of new high EPS producers is of paramount importance. Many marine bacteria, that produce EPS to cope with strong environmental stress, could be potentially exploited at the industrial level.ResultsA novel bacterium, strain BM39, previously isolated from sediments collected in the Tyrrhenian Sea, was selected for its production of very high levels of EPS. BM39 was affiliated to Pantoea sp. (Enterobacteriaceae) by 16S rRNA gene sequencing and biochemical tests. According to the phylogenetic tree, this strain, being quite far from the closest known Pantoea species (96% identity with P. agglomerans and P. ananatis) could belong to a new species. EPS production was fast (maximum of ca. 21 g/L in 24 h on glucose medium) and mainly obtained during the exponential growth. Preliminary characterization, carried out by thin layer and gel filtration chromatography, showed that the EPS, being a glucose homopolymer with MW of ca. 830 kDa, appeared to be different from those of other bacteria of same genus. The bacterium showed a typical slightly halophilic behavior growing optimally at NaCl 40 ‰ (growing range 0-100 ‰). Flow cytometry studies indicated that good cell survival was maintained for 24 h at 120 ‰. Survival decreased dramatically with the increase of salinity being only 1 h at 280 ‰. The biochemical characterization, carried out with the Biolog system, showed that MB39 had a rather limited metabolic capacity. Its ability, rather lower than that of P. agglomerans, was almost only confined to the metabolization of simple sugars and their derivatives. Few alcohols, organic acids and nitrogen compounds were partially used too.ConclusionsStrain BM39, probably belonging to a new species, due to its remarkable EPS production, comparable to those of known industrial bacterial producers, could be suggested as a new microorganism for industrial applications.

A Case of Pantoea species Cholangitis with Bacteremia

Pantoea infections are rare in humans and an unusual cause for sepsis in immunocompetent patient. It is a gram-nagative bacillus of the family Enterobacteriaceae. Infections are usually associated with plant thorn injury or outbreak traced to comtaminated par enteral nutrition. We experienced a case of pantoea species cholecystitis and cholangitis with bacteremia. The patient was adminis trated intravenous antibiotics, and then patient was improved.

Detection and Molecular Diversity of Pantoea ananatis Associated with White Spot Disease in Maize, Sorghum and Crabgrass in Brazil

AbstractBacteria of the genus Pantoea have become important plant pathogens worldwide in recent years. Pantoea ananatis was reported as the cause of maize white spot, a serious maize disease in Brazil, causing significant yield losses. However, very little information is available about how to detect this pathogen, its genetic variability and the putative alternative hosts in maize‐growing areas. To address these issues, we implemented a rapid and efficient PCR‐based method to identify P. ananatis isolated from leaves showing white spot symptoms and evaluated its genetic diversity in maize, sorghum and crabgrass. Of the 29 bacteria isolated from typical water‐soaked lesions of white spot disease that produced yellow colonies, 15 isolates were identified as P. ananatis by 16S rDNA sequencing and correctly detected by the PCR reaction, amplifying a specific fragment of the ice nucleation gene (ina). These P. ananatis isolates included 13 from maize, one from sorghum and one from crabgrass, while the other 14 yellow colony isolates were from other bacterial species, including two Pantoea species (Pantoea dispersa and Pantoea agglomerans) that were not amplified by the ina primers. These results indicate that the optimized PCR assay can be used to detect P. ananatis isolated from white spot lesions and could be used as a large‐scale and cost‐effective method of detecting this pathogen in leaf lesions on maize and other grasses. All isolates were evaluated for hypersensitive response (HR) on tobacco, revealing that some P. ananatis were able to induce HR. The high genetic variability revealed by rep‐PCR did not differentiated the P. ananatis isolates based on their hosts or HR reaction. The detection, characterization and diversity of P. ananatis from maize, sorghum and crabgrass in our study can be applied in understanding epidemiology and designing control strategies for maize white spot disease in Brazil.

Characterization of the Biosynthetic Operon for the Antibacterial Peptide Herbicolin in Pantoea vagans Biocontrol Strain C9-1 and Incidence in Pantoea Species

Pantoea vagans C9-1 is a biocontrol strain that produces at least two antibiotics inhibiting the growth of Erwinia amylovora, the causal agent of fire blight disease of pear and apple. One antibiotic, herbicolin I, was purified from culture filtrates of P. vagans C9-1 and determined to be 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, also known as N(ß)-epoxysuccinamoyl-DAP-valine. A plasposon library was screened for mutants that had lost the ability to produce herbicolin I. It was shown that mutants had reduced biocontrol efficacy in immature pear assays. The biosynthetic gene cluster in P. vagans C9-1 was identified by sequencing the flanking regions of the plasposon insertion sites. The herbicolin I biosynthetic gene cluster consists of 10 coding sequences (CDS) and is located on the 166-kb plasmid pPag2. Sequence comparisons identified orthologous gene clusters in Pantoea agglomerans CU0119 and Serratia proteamaculans 568. A low incidence of detection of the biosynthetic cluster in a collection of 45 Pantoea spp. from biocontrol, environmental, and clinical origins showed that this is a rare trait among the tested strains.

The Evolutionary Innovation of Nutritional Symbioses in Leaf-Cutter Ants.

Fungus-growing ants gain access to nutrients stored in plant biomass through their association with a mutualistic fungus they grow for food. This 50 million-year-old obligate mutualism likely facilitated some of these species becoming dominant Neotropical herbivores that can achieve immense colony sizes. Recent culture-independent investigations have shed light on the conversion of plant biomass into nutrients within ant fungus gardens, revealing that this process involves both the fungal cultivar and a symbiotic community of bacteria including Enterobacter, Klebsiella, and Pantoea species. Moreover, the genome sequences of the leaf-cutter ants Atta cephalotes and Acromyrmex echinatior have provided key insights into how this symbiosis has shaped the evolution of these ants at a genetic level. Here we summarize the findings of recent research on the microbial community dynamics within fungus-growing ant fungus gardens and discuss their implications for this ancient symbiosis.

The large universal Pantoea plasmid LPP-1 plays a major role in biological and ecological diversification

BackgroundPantoea spp. are frequently isolated from a wide range of ecological niches and have various biological roles, as plant epi- or endophytes, biocontrol agents, plant-growth promoters or as pathogens of both plant and animal hosts. This suggests that members of this genus have undergone extensive genotypic diversification. One means by which this occurs among bacteria is through the acquisition and maintenance of plasmids. Here, we have analyzed and compared the sequences of a large plasmid common to all sequenced Pantoea spp.Results and discussionThe Large PantoeaPlasmids (LPP-1) of twenty strains encompassing seven different Pantoea species, including pathogens and endo-/epiphytes of a wide range of plant hosts as well as insect-associated strains, were compared. The LPP-1 plasmid sequences range in size from ~281 to 794 kb and carry between 238 and 750 protein coding sequences (CDS). A core set of 46 proteins, encompassing 2.2% of the total pan-plasmid (2,095 CDS), conserved among all LPP-1 plasmid sequences, includes those required for thiamine and pigment biosynthesis. Phylogenetic analysis reveals that these plasmids have arisen from an ancestral plasmid, which has undergone extensive diversification. Analysis of the proteins encoded on LPP-1 also showed that these plasmids contribute to a wide range of Pantoea phenotypes, including the transport and catabolism of various substrates, inorganic ion assimilation, resistance to antibiotics and heavy metals, colonization and persistence in the host and environment, pathogenesis and antibiosis.ConclusionsLPP-1 is universal to all Pantoea spp. whose genomes have been sequenced to date and is derived from an ancestral plasmid. LPP-1 encodes a large array of proteins that have played a major role in the adaptation of the different Pantoea spp. to their various ecological niches and their specialization as pathogens, biocontrol agents or benign saprophytes found in many diverse environments.

Pantoea species sepsis associated with sickle cell crisis in a pregnant woman with a history of pica

SummaryBackground:Bacteria in the Pantoea genus are plant and soil associated Gram-negative rods described as nosocomial pathogens and as rare causes of community-acquired infections. The latter have been classically associated with gardening and plant thorn injuries and immunocompromised states are additional risk factors. We report a patient with pica and geophagia, Pantoea sepsis, and sickle cell crisis, associations not previously described.Case Report:A 23-year-old pregnant female presented to the emergency department with sickle cell pain crisis. On the third day of hospitalization the patient developed fever subsequently determined to be caused by Pantoea bacteremia and sepsis. She was successfully treated with a two-week course of ceftriaxone. The patient admitted to a habit of frequently eating large amounts of soil and this geophagia had increased since she became pregnant. She had marked clinical improvement with treatment and she was counseled to stop eating soil.Conclusions:This is the first reported case of Pantoea infection possibly associated with geophagia and the first reported case of Pantoea bacteremia and sepsis related to an episode of sickle cell crisis.