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Microorganisms Oct 2022Multifaceted microorganisms such as the bacterium colonize a wide range of habitats and can exhibit both beneficial and harmful behaviors, which provide new insights... (Review)
Review
Multifaceted microorganisms such as the bacterium colonize a wide range of habitats and can exhibit both beneficial and harmful behaviors, which provide new insights into microbial ecology. In the agricultural context, several strains of spp. can promote plant growth through direct or indirect mechanisms. Members of this genus contribute to plant growth mainly by increasing the supply of nitrogen, solubilizing ammonia and inorganic phosphate, and producing phytohormones (e.g., auxins). Several other studies have shown the potential of strains of spp. to induce systemic resistance and protection against pests and pathogenic microorganisms in cultivated plants. Strains of the species deserve attention as a pest and phytopathogen control agent. Several of them also possess a biotechnological potential for therapeutic purposes (e.g., immunomodulators) and are implicated in human infections. Thus, the differentiation between the harmful and beneficial strains of is mandatory to apply this bacterium safely as a biofertilizer or biocontroller. This review specifically evaluates the potential of the strain-associated features of for bioprospecting and agricultural applications through its biological versatility as well as clarifying its potential animal and human health risks from a genomic point of view.
PubMed: 36296348
DOI: 10.3390/microorganisms10102072 -
Plants (Basel, Switzerland) Oct 2022Bacteria from the genus have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected... (Review)
Review
Bacteria from the genus have been reported to be widely distributed in rice paddy environments with contradictory roles. Some strains promoted rice growth and protected rice from pathogen infection or abiotic stress, but other strain exhibited virulence to rice, even causing severe rice disease. In order to effectively utilize in rice production, this paper analyzed the mechanisms underlying beneficial and harmful effects of on rice growth. The beneficial effect of on rice plants includes growth promotion, abiotic alleviation and disease inhibition. The growth promotion may be mainly attributed to nitrogen-fixation, phosphate solubilization, plant physiological change, the biosynthesis of siderophores, exopolysaccharides, 1-aminocyclopropane-1-carboxylic acid deaminase and phytohormones, including cytokinin, indole-3-acetic acid (IAA), auxins, abscisic acid and gibberellic acid, while the disease inhibition may be mainly due to the induced resistance, nutrient and spatial competition, as well as the production of a variety of antibiotics. The pathogenic mechanism of can be mainly attributed to bacterial motility, production of phytohormones such as IAA, quorum sensing-related signal molecules and a series of cell wall-degrading enzymes, while the pathogenicity-related genes of include genes encoding plasmids, such as the pPATH plasmid, the hypersensitive response and pathogenicity system, as well as various types of secretion systems, such as T3SS and T6SS. In addition, the existing scientific problems in this field were discussed and future research prospects were proposed.
PubMed: 36235474
DOI: 10.3390/plants11192608 -
Applied and Environmental Microbiology Dec 2023Phage-derived bacteriocins (tailocins) are ribosomally synthesized structures produced by bacteria in order to provide advantages against competing strains under natural...
Phage-derived bacteriocins (tailocins) are ribosomally synthesized structures produced by bacteria in order to provide advantages against competing strains under natural conditions. Tailocins are highly specific in their target range and have proven to be effective for the prevention and/or treatment of bacterial diseases under clinical and agricultural settings. We describe the discovery and characterization of a new tailocin locus encoded within genomes of and subsp. , which may enable the development of tailocins as preventative treatments against phytopathogenic infection by these species.
Topics: Bacteriocins; Pantoea; Plant Diseases
PubMed: 37982620
DOI: 10.1128/aem.00929-23 -
Applied and Environmental Microbiology Mar 2022Pantoea ananatis is an emerging plant pathogen that causes disease in economically important crops such as rice, corn, onion, melon, and pineapple, and it also infects...
Negatively Regulated Aerobactin and Desferrioxamine E by Fur in Pantoea ananatis Are Required for Full Siderophore Production and Antibacterial Activity, but Not for Virulence.
Pantoea ananatis is an emerging plant pathogen that causes disease in economically important crops such as rice, corn, onion, melon, and pineapple, and it also infects humans and insects. In this study, we identified biosynthetic gene clusters of aerobactin and desferrioxamine E (DFO-E) siderophores by using the complete genome of PA13 isolated from rice sheath rot. PA13 exhibited the strongest antibacterial activity against Erwinia amylovora and Yersinia enterocolitica (). Mutants of aerobactin or DFO-E maintained antibacterial activity against E. amylovora and Y. enterocolitica, as well as in a siderophore activity assay. However, double aerobactin and DFO-E gene deletion mutants completely lost siderophore and antibacterial activity. These results reveal that both siderophore biosynthetic gene clusters are essential for siderophore production and antibacterial activity in PA13. A ferric uptake regulator protein (Fur) mutant exhibited a significant increase in siderophore production, and a Fur-overexpressing strain completely lost antibacterial activity. Expression of the , and genes was significantly increased in the Δ mutant background, and expression of these genes returned to wild-type levels after compensation. These results indicate that Fur negatively regulates aerobactin and DFO-E siderophores. However, siderophore production was not required for virulence in plants, but it appears to be involved in the microbial ecology surrounding the plant environment. This study is the first to report the regulation and functional characteristics of siderophore biosynthetic genes in . Pantoea ananatis is a bacterium that causes diseases in several economically important crops, as well as in insects and humans. This bacterium has been studied extensively as a potentially dangerous pathogen due to its saprophytic ability. Recently, the types, biosynthetic gene clusters, and origin of the siderophores in the genus were determined by using genome comparative analyses. However, few genetic studies have investigated the characteristics and functions of siderophores in . The results of this study revealed that the production of aerobactin and desferrioxamine E in the rice pathogen PA13 is negatively regulated by Fur and that these siderophores are essential for antibacterial activity against Erwinia amylovora and Yersinia enterocolitica (). However, siderophore production was not required for virulence in plants, but it appears to be involved in the microbial ecology surrounding the plant environment.
Topics: Anti-Bacterial Agents; Humans; Hydroxamic Acids; Lactams; Pantoea; Siderophores; Virulence
PubMed: 35108090
DOI: 10.1128/aem.02405-21 -
Cureus Feb 2021is a plant pathogen infrequently reported to cause opportunistic bloodstream infections. This gram-negative bacillus is a rare cause of hospital-acquired infections in... (Review)
Review
is a plant pathogen infrequently reported to cause opportunistic bloodstream infections. This gram-negative bacillus is a rare cause of hospital-acquired infections in newborn infants with high mortality. Since the creation of the new genus in 1989, the evidence base available to neonatal health care providers is limited. Most of the available literature consists of case reports and case series. This review aims to consolidate the current reported literature on Pantoea infections, focusing on newborn infants and the neonatal intensive care unit (NICU). Prematurity and the associated relative immunocompromised state are major risk factors for hospital-acquired infections due to in newborn infants. Recent advances in molecular biology have improved our understanding of the cross-kingdom pathogenesis exhibited by . Respiratory symptoms and association with central venous lines are the most common clinical presentation of bacteremia in newborn infants. Early institution of appropriate antibiotic therapy against this organism could be lifesaving. Therefore, it is critical for neonatologists to understand the clinical spectrum of infections in NICUs.
PubMed: 33643749
DOI: 10.7759/cureus.13103 -
Frontiers in Microbiology 2019Members of the genus are Gram-negative bacteria isolated from various environments. Taxonomic affiliation based on multilocus sequence analysis (MLSA) is used routinely...
Members of the genus are Gram-negative bacteria isolated from various environments. Taxonomic affiliation based on multilocus sequence analysis (MLSA) is used routinely for inferring accurate phylogeny and identification of bacterial species and genera. Partial sequences of five housekeeping genes (A, B, S, B, and G) were extracted from 206 draft or complete genomes of strains publicly available in databases and analyzed together with the representative sequences of the 25 validly published type strains to verify and assess their phylogenetic assignations. Of a total of 159 strains assigned to species level, 11.3% of the non-type strains were incorrectly assigned within suitable species. The highest proportion of misidentified strains was recorded in , 8 out of 15 (53.3%) inaccurate assignations at the species level. One probable reason for this incorrect classification could be the method previously used for strain identification. Forty-seven (22.8%) genome sequences were from strains identified at the genus level only ( sp.). A combination of MLSA, average nucleotide identities [ANI and MuMmer-based ANI (ANIm)], tetranucleotide usage pattern (TETRA), and genome-based DNA-DNA hybridization (gDDH) data was used to accurately assign 25 of the 47 strains to validly published species, while 17 strains could be assigned as putative novel species within the genus . Four genomes designed as sp. were identified as . Positive and significant correlation coefficients were computed between MLSA and all the indices derived from whole-genome sequences being proposed for species delimitation. gDDH exhibited the best correlation with MLSA while TETRA was the worst. Accurate species-level identification is key to a better understanding of bacterial diversity and evolution. The MLSA scheme used here could be instrumental to determine the correct taxonomic status of new whole-genome sequenced strains, especially non-type strains, before depositing into public databases.
PubMed: 31736906
DOI: 10.3389/fmicb.2019.02463 -
Plant Disease Nov 2023Nearly 5,400 hectares of long-day onions () are cultivated in the Central Zone of Chile (UTM 33°3´S to 37°24´S). During summer 2021-22 and 2022-23 (December to...
Nearly 5,400 hectares of long-day onions () are cultivated in the Central Zone of Chile (UTM 33°3´S to 37°24´S). During summer 2021-22 and 2022-23 (December to February), followed by high temperatures (around 35°C) and high humidity conditions, symptoms showing yellowing, soft rot, blight on old leaves, necrotic tips, and soft bulbs were observed. The affected plants were observed in "spots" into the fields, and the incidence reached 5-10%. The severity was high, and 70-80% of the affected plants died. Symptomatic plants from different fields from the Coquimbo, Metropolitan, O´Higgins and Maule regions were sampled. Isolations were made using casamino-acid peptone glucose (CPG) agar medium (Schaad, 2001). Yellow-pigmented, circular to irregular shaped colonies were observed. Molecular identification was carried out by partial 16S rRNA gene sequencing, resulting in the identification of 18 isolates of spp. from twelve different fields. Selected strains were biochemically analyzed using the GEN III BIOLOG microtest system (Hayward, CA) and were identified as spp. BLAST analyses of the 16S rRNA sequences (602 nt) of selected strains (GenBank Accession No. OR527817 to OR527819) against the NCBI Database resulted in the identification of species with 100% coverage and 100% identity. To determine the species of each strain, housekeeping gene (Delétoile et al. 2009) was amplified and sequenced (GenBank Accessions No. OR544061 to OR544063). BLAST analysis (802 nt) of selected strains resulted in 100% coverage and 100% identity, identifying three different species: , , and . species were isolated from both leaves and bulbs and no more than one species was observed per field. Pathogenicity assays in onion plants and bulbs were performed based on the methodology described by Asselin et al. (2018). Five onion plants cv. Cimarron of thirteen-week-old were inoculated by wounding an external leave with a sterile toothpick previously immersed in a bacterial suspension at ~ 108 CFU/mL and maintained at 26-28°C for 30 days in high humidity conditions. Control plants were inoculated with sterile water. Plants inoculated with spp. showed chlorosis, soft rot, and necrosis mainly in older leaves, as observed in the field, while negative control plants remained healthy. Pantoea spp. were re-isolated from the inoculated onion plants. Toothpicks dipped in the inoculum were stuck 4 cm into the shoulders of onion bulbs and incubated at 26°C for 20 days. Water was inoculated as a negative control. At the end of the incubation period, the bulbs were opened longitudinally across their inoculation sites and shrunken, brownish, watery scales were observed. species have been previously described as causing leaf blight of onions in Georgia and Michigan in the USA and South Africa, Brazil, and Uruguay (Hattingh and Walters 1981; Gitaitis and Gay 1997; Edens et al. 2006; Tho et al. 2015; De Armas et al. 2022; Rosende et al. 2022). was recently reported in Chile (Sepúlveda et al. 2023), but this is the first report of and affecting onions in central Chile. This detection is an alert call for the onion's growers and exporters in Chile for upcoming seasons, where conditions predisposing to disease may continue to occur. It is crucial to continue analyzing the factors that caused the appearance of this new disease in onions.
PubMed: 37990524
DOI: 10.1094/PDIS-09-23-1884-PDN -
Annals of Agricultural and... Jun 2016Pantoea agglomerans, a bacterium associated with plants, is not an obligate infectious agent in humans. However, it could be a cause of opportunistic human infections,... (Review)
Review
Pantoea agglomerans, a bacterium associated with plants, is not an obligate infectious agent in humans. However, it could be a cause of opportunistic human infections, mostly by wound infection with plant material, or as a hospital-acquired infection, mostly in immunocompromised individuals. Wound infection with P. agglomerans usually follow piercing or laceration of skin with a plant thorn, wooden splinter or other plant material and subsequent inoculation of the plant-residing bacteria, mostly during performing of agricultural occupations and gardening, or children playing. Septic arthritis or synovitis appears as a common clinical outcome of exogenous infection with P. agglomerans, others include endophthalmitis, periostitis, endocarditis and osteomyelitis. Another major reason for clinical infection with P. agglomerans is exposure of hospitalized, often immunodeficient individuals to medical equipment or fluids contaminated with this bacterium. Epidemics of nosocomial septicemia with fatal cases have been described in several countries, both in adult and paediatric patients. In most cases, however, the clinical course of the hospital-acquired disease was mild and application of the proper antibiotic treatment led to full recovery. Compared to humans, there are only few reports on infectious diseases caused by Pantoea agglomerans in vertebrate animals. This species has been identified as a possible cause of equine abortion and placentitis and a haemorrhagic disease in dolphin fish (Coryphaena hippurus). P. agglomerans strains occur commonly, usually as symbionts, in insects and other arthropods. Pantoea agglomerans usually occurs in plants as an epi- or endophytic symbiont, often as mutualist. Nevertheless, this species has also also been identified as a cause of diseases in a range of cultivable plants, such as cotton, sweet onion, rice, maize, sorghum, bamboo, walnut, an ornamental plant called Chinese taro (Alocasia cucullata), and a grass called onion couch (Arrhenatherum elatius). Some plant-pathogenic strains of P. agglomerans are tumourigenic, inducing gall formation on table beet, an ornamental plant gypsophila (Gypsophila paniculata), wisteria, Douglas-fir and cranberry. Recently, a Pantoea species closely related to P. agglomerans has been identified as a cause of bacterial blight disease in the edible mushroom Pleurotus eryngii cultivated in China. The genetically governed determinants of plant pathogenicity in Pantoea agglomerans include such mechanisms as the hypersensitive response and pathogenicity (hrp) system, phytohormones, the quorum-sensing (QS) feedback system and type III secretion system (T3SS) injecting the effector proteins into the cytosol of a plant cell.
Topics: Animals; Animals, Domestic; Arthropods; Cross Infection; Enterobacteriaceae Infections; Humans; Pantoea; Plant Diseases
PubMed: 27294620
DOI: 10.5604/12321966.1203878 -
Frontiers in Microbiology 2023As the name of the genus ("of all sorts and sources") suggests, this genus includes bacteria with a wide range of provenances, including plants, animals, soils,...
As the name of the genus ("of all sorts and sources") suggests, this genus includes bacteria with a wide range of provenances, including plants, animals, soils, components of the water cycle, and humans. Some members of the genus are pathogenic to plants, and some are suspected to be opportunistic human pathogens; while others are used as microbial pesticides or show promise in biotechnological applications. During its taxonomic history, the genus and its species have seen many revisions. However, evolutionary and comparative genomics studies have started to provide a solid foundation for a more stable taxonomy. To move further toward this goal, we have built a 2,509-gene core genome tree of 437 public genome sequences representing the currently known diversity of the genus . Clades were evaluated for being evolutionarily and ecologically significant by determining bootstrap support, gene content differences, and recent recombination events. These results were then integrated with genome metadata, published literature, descriptions of named species with standing in nomenclature, and circumscriptions of yet-unnamed species clusters, 15 of which we assigned names under the nascent SeqCode. Finally, genome-based circumscriptions and descriptions of each species and each significant genetic lineage within species were uploaded to the LINbase Web server so that newly sequenced genomes of isolates belonging to any of these groups could be precisely and accurately identified.
PubMed: 38029109
DOI: 10.3389/fmicb.2023.1254999 -
Annals of Agricultural and... Jun 2016Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal... (Review)
Review
Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others) which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as 'Immunopotentiator from Pantoea agglomerans 1 (IP-PA1)' reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of plant resistance. Its use as a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. P. agglomerans strains associated with both rhizosphere and plant tissues (as endophytes) efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, P. agglomerans is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the Pantoea strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. P. agglomerans prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of P. agglomerans in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of Pantoea genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the Pantoea biopreparations are maintained.
Topics: Adjuvants, Immunologic; Biological Control Agents; Communicable Disease Control; Environmental Restoration and Remediation; Fertilizers; Pantoea
PubMed: 27294621
DOI: 10.5604/12321966.1203879