Isolation of Pantoea agglomerans in two cases of septic monoarthritis after plant thorn and wood sliver injuries

Pantoea Species Bacteremia in a Child With Sickle Cell Disease: A Case Report

The Pantoea genus of bacteria is a group of Gram-negative rod-shaped bacteria in the Enterobacteriaceae family. It is an uncommon cause of infection in humans except in specific settings, including hospital-acquired infections and in immunocompromised patients. In this report, we describe the case of a 12-year-old girl with sickle cell disease who presented with a picture of sepsis and was found to have Pantoea species in her blood culture which was treated with antibiotics with a good response. From our literature review, risk factors were identified in the reported cases, for which further exploration is highly recommended.

Bloodstream Infections by Pantoea Species: Clinical and Microbiological Findings from a Retrospective Study, Italy, 2018-2023

(1) Background: The widespread use of MALDI-TOF coupled to mass spectrometry has improved diagnostic accuracy by identifying uncommon bacteria. Among Enterobacterales, Pantoea species have been seen to be implicated in several human infections, but their clinical and microbiological framework is currently based on a few anecdotal reports. (2) Methods: We conducted this five-year (2018-2023) single-center study aimed at investigating the prevalence and clinical and microbiological findings of Pantoea species bloodstream infections. (3) Results: Among the 4996 bloodstream infection Gram-negative isolates collected during the study period, Pantoea species accounted for 0.4% (n = 19) of isolates from 19 different patients, 5 of them being pediatric cases. Among Pantoea species isolates, P. agglomerans was the most frequently detected (45%; n = 9) followed by P. eucrina (30%; n = 6) and P. septica (15%; n = 3). Malignancy (35.7%) in adults and malignancy (40%) and cerebrovascular disease following meconium aspiration (40%) in pediatric patients as comorbidities and shivering and/or fever following parenteral infusion (36.8%) as a symptom/sign of Pantoea species bloodstream infection onset were the most frequently observed clinical features. Among adults, primary bloodstream infection was the most frequent (50%), whereas among pediatric patients, the most commonly identified sources of infection were catheter-related (40%) and the respiratory tract (40%). Overall, Pantoea species bloodstream infection isolates displayed high susceptibility to all the antibiotics except for ampicillin (63.2%), fosfomycin (73.7%), and piperacillin/tazobactam (84.2%). Targeted antibiotic treatment was prescribed as monotherapy for adults (71.4%) and combination therapy for pediatric patients (60%). The most prescribed antibiotic regimens were piperacillin/tazobactam (21.4%) in adults and meropenem- (40%) and aminoglycoside-containing (40%) antibiotics in pediatric patients. The overall 28-day all-cause mortality rate was 5.3% (n = 1). (4) Conclusions: The prevalence and 28-day mortality rate of Pantoea species bloodstream infections were low. The prescription of targeted therapy including broad-spectrum antibiotics could indicate an underestimation of the specific involvement of the Pantoea species in the onset of the disease, warranting further studies defining their pathogenic potential.

Pantoea abscess mimicking sarcoma in a HTLV-1-infected Indigenous Australian man: Case report and literature review

Gram-negative bacteria of the genus Pantoea are emerging bacterial causes of diverse sporadic and outbreak-linked infections. Chronic Pantoea abscesses are unusual and may give rise to a differential diagnosis of malignancy. Foreign body retention and host immune defects may be risk factors for such chronic infections.

A Thorn in a Haystack: A Rare Case of Septic Arthritis

Pantoea agglomerans is a facultative anaerobe and environmental bacterium that could be a cause of opportunistic human infections, especially in wound infection with plant material. Arthritis or synovitis secondary to penetrating plant thorn injuries is not frequently reported. We present the case of a 35-year-old otherwise healthy male with a bramble thorn penetrating injury of the left knee. P. agglomerans was isolated from the synovial fluid. The patient was treated with amoxicillin/clavulanate according to sensitivity testing. This case highlights the importance of precise and thorough medical history, especially for less common presentations, as well as source control.

A Case of Nosocomial Outbreak of Pantoea agglomerans Related to Parenteral Nutrition Procedures

Pantoea agglomerans is a Gram-negative bacterium that infrequently infects humans. Most reports involving it are about infections in soft tissues or bone/joint infections caused by contamination from soil or penetrating trauma by vegetation, such as thorns and splinters. More frequently, it is found as an opportunistic pathogen in immunocompromised patients. It is not rare to find reports of bacteremia and sepsis from contamination of intravenous fluid, parenteral nutrition, blood products and anesthetic agents-that is, through contamination of medical devices and products. We reported a bacterial infection epidemic occurred in 2011 in a hospital in middle Italy which involved different hospital wards; Pantoea agglomerans was isolated from blood cultures of all infected patients and the source of infection was identified in contaminated parenteral nutrition prepared from the local pharmacy.

Wound infection by Pantoea agglomerans after penetrating plant injury

Pantoea agglomerans is a ubiquitous gram-negative bacterium that has been linked to skin and joint infections secondary to plant injuries. Herein we report a 58-year-old woman who presented with 2 erythematous nodules with purulent discharge on the anterior aspect of the right leg that developed after a penetrating plant injury. The patient was initially treated with amoxicillin-clavulanic acid, cloxacillin and clindamycin without improvement. P. agglomerans was isolated from both exudate and skin biopsy cultures. Healing of the lesions was achieved after the spontaneous release of a retained plant fragment and treatment with cotrimoxazole. Identification of P. agglomerans in persistent exudative lesions should alert the clinician regarding a possible previous plant injury and retained vegetal fragments. Conventional antibiotic treatment and the extraction of retained foreign bodies usually lead to complete resolution.

Septic arthritis of the knee due to Pantoea agglomerans: look for the thorn

We report on a patient with septic arthritis of the knee with Pantoea agglomerans after a penetrating black locust thorn injury. Antibiotics alone or in combination with an arthroscopy may be insufficient for achieving source control. Accurate medical history and open debridement with a search for a thorn fragment are key to successful treatment.

Comprehensive genomic analysis reveals virulence factors and antibiotic resistance genes in Pantoea agglomerans KM1, a potential opportunistic pathogen

Pantoea agglomerans is a Gram-negative facultative anaerobic bacillus causing a wide range of opportunistic infections in humans including septicemia, pneumonia, septic arthritis, wound infections and meningitis. To date, the determinants of virulence, antibiotic resistance, metabolic features conferring survival and host-associated pathogenic potential of this bacterium remain largely underexplored. In this study, we sequenced and assembled the whole-genome of P. agglomerans KM1 isolated from kimchi in South Korea. The genome contained one circular chromosome of 4,039,945 bp, 3 mega plasmids, and 2 prophages. The phage-derived genes encoded integrase, lysozyme and terminase. Six CRISPR loci were identified within the bacterial chromosome. Further in-depth analysis showed that the genome contained 13 antibiotic resistance genes conferring resistance to clinically important antibiotics such as penicillin G, bacitracin, rifampicin, vancomycin, and fosfomycin. Genes involved in adaptations to environmental stress were also identified which included factors providing resistance to osmotic lysis, oxidative stress, as well as heat and cold shock. The genomic analysis of virulence factors led to identification of a type VI secretion system, hemolysin, filamentous hemagglutinin, and genes involved in iron uptake and sequestration. Finally, the data provided here show that, the KM1 isolate exerted strong immunostimulatory properties on RAW 264.7 macrophages in vitro. Stimulated cells produced Nitric Oxide (NO) and pro-inflammatory cytokines TNF-α, IL-6 and the anti-inflammatory cytokine IL-10. The upstream signaling for production of TNF-α, IL-6, IL-10, and NO depended on TLR4 and TLR1/2. While production of TNF-α, IL-6 and NO involved solely activation of the NF-κB, IL-10 secretion was largely dependent on NF-κB and to a lesser extent on MAPK Kinases. Taken together, the analysis of the whole-genome and immunostimulatory properties provided in-depth characterization of the P. agglomerans KM1 isolate shedding a new light on determinants of virulence that drive its interactions with the environment, other microorganisms and eukaryotic hosts

Culture-Proven Thorn-Associated Infections in Arizona: 10-Year Experience at Mayo Clinic

Background

Thorn injuries are common in the desert Southwest; however, the frequency and microbiology of thorn-associated infections have not been systematically described. Most information comes from case reports describing infections from atypical or environmental microorganisms. Our aim was to summarize the spectrum of thorn-associated infections.

Methods

We conducted a retrospective review of electronic health records for patients presenting to our institution from January 1, 2005 to December 31, 2014 for treatment of thorn-associated injuries and then focused on the patients with cultures.

Results

Of 2758 records reviewed, 1327 patients had thorn-associated injuries; however, only 58 (4.4%) had cultures. Of these patients, 37 (64%) had positive findings; 5 had polymicrobial infection. The most commonly identified organisms were Staphylococcus aureus (n = 22, 59.0%) and coagulase-negative Staphylococcus species (n = 8, 21.6%). Other pathogens included Nocardia species (n = 3, 8.1%), Streptococcus species (n = 2, 5.4%), Gram-negative bacteria (n = 2, 5.4%), Aspergillus species (n = 2, 5.4%), Paecilomyces lilacinus (n = 1, 2.7%), and Candida species (n = 1, 2.7%). There were no infections caused by Pantoea agglomerans, Sporothrix schenckii, or Coccidioides spp.

Conclusions

In contrast to most published case reports, we found that typical cutaneous microorganisms, such as Staphylococcus species, caused the majority of culture-positive, thorn-related infections.

Draft genome sequences of Pantoea agglomerans and Pantoea vagans isolates associated with termites

The genus Pantoea incorporates many economically and clinically important species. The plant-associated species, Pantoea agglomerans and Pantoea vagans, are closely related and are often isolated from similar environments. Plasmids conferring certain metabolic capabilities are also shared amongst these two species. The genomes of two isolates obtained from fungus-growing termites in South Africa were sequenced, assembled and annotated. A high number of orthologous genes are conserved within and between these species. The difference in genome size between P. agglomerans MP2 (4,733,829 bp) and P. vagans MP7 (4,598,703 bp) can largely be attributed to the differences in plasmid content. The genome sequences of these isolates may shed light on the common traits that enable P. agglomerans and P. vagans to co-occur in plant- and insect-associated niches.

A Novel Glycolipid Biosurfactant Confers Grazing Resistance upon Pantoea ananatis BRT175 against the Social Amoeba Dictyostelium discoideum

Pantoea is a versatile genus of bacteria with both plant- and animal-pathogenic strains, some of which have been suggested to cause human infections. There is, however, limited knowledge on the potential determinants used for host association and pathogenesis in animal systems. In this study, we used the model host Dictyostelium discoideum to show that isolates of Pantoea ananatis exhibit differential grazing susceptibility, with some being resistant to grazing by the amoebae. We carried out a high-throughput genetic screen of one grazing-resistant isolate, P. ananatis BRT175, using the D. discoideum pathosystem to identify genes responsible for the resistance phenotype. Among the 26 candidate genes involved in grazing resistance, we identified rhlA and rhlB, which we show are involved in the biosynthesis of a biosurfactant that enables swarming motility in P. ananatis BRT175. Using liquid chromatography-mass spectrometry (LC-MS), the biosurfactant was shown to be a glycolipid with monohexose-C10-C10 as the primary congener. We show that this novel glycolipid biosurfactant is cytotoxic to the amoebae and is capable of compromising cellular integrity, leading to cell lysis. The production of this biosurfactant may be important for bacterial survival in the environment and could contribute to the establishment of opportunistic infections. IMPORTANCE The genetic factors used for host interaction by the opportunistic human pathogen Pantoea ananatis are largely unknown. We identified two genes that are important for the production of a biosurfactant that confers grazing resistance against the social amoeba Dictyostelium discoideum. We show that the biosurfactant, which exhibits cytotoxicity toward the amoebae, is a glycolipid that incorporates a hexose rather than rhamnose. The production of this biosurfactant may confer a competitive advantage in the environment and could potentially contribute to the establishment of opportunistic infections.

A Sub-acute Septic Arthritis of the Knee; a Sequelae to Thorn Prick Injury of Patella: A Case Report

INTRODUCTION

Sub-acute septic arthritis of knee following a thorn prick injury to patella is an uncommon condition and seen in active playful children. The child may be afraid to narrate the incident to their parents or examining doctor, so a high index of suspicion is must. The delayed presentation is inevitable. Early synovitis due to the organic biological foreign body may progress to septic arthritis, if untreated may result in knee stiffness or chronic osteomyelitis of patella.

CASE REPORT

We report a case of thorn prick injury to the left patella in an 8-years-old boy who neglected the incident of thorn prick while playing with his peer group 10 days ago and presented with features of sub-acute septic arthritis. He was treated by arthrotomy, double inspection of the patella, removal of foreign body, synovectomy, lavage, antibiotics, and aggressive rehabilitation with an excellent outcome.

CONCLUSION

Sub-acute synovitis in active playful children should raise the suspicion of thorn prick even though no proper history is explained. Organic foreign body from plant materials is radiolucent and easily missed. High suspicion and timely surgical intervention, double inspection during arthrotomy identifies the foreign body. Once removed, with proper antibiotic and physiotherapy protocol followed has an excellent outcome.

Successful treatment of sepsis due to Pantoea agglomerans by polymyxin B-immobilized fiber column direct hemoperfusion therapy in a small cell lung carcinoma patient

Sepsis is a life-threatening condition caused by the inflammatory response to invading organisms. Polymyxin B-immobilized fiber column direct hemoperfusion (PMX-DHP) is used to reduce blood endotoxin levels and modulate circulating inflammatory cytokine levels in sepsis patients. Here we report that severe sepsis caused by an infection of the gram-negative bacterium Pantoea agglomerans in a patient with small cell lung carcinoma was treated successfully with antibiotics and PMX-DHP. The patient, a 49-year-old Japanese male smoker whose condition was complicated with hyponatremia due to SIADH (syndrome of inappropriate secretion of antidiuretic hormone), rapidly developed sepsis and disseminated intravascular coagulation (DIC) after the administration of cisplatin and irinotecan. Despite initial antibiotics therapy, severe host responses including hypotension, high body temperature and tachycardia were noted. We initiated PMX-DHP, and the patient's Sequential Organ Failure Assessment score was greatly reduced and his DIC improved immediately. To our knowledge, this is the first reported case of PMX-DHP therapy for severe sepsis caused by P. agglomerans infection. Although the efficacy of PMX-DHP in sepsis is not well defined, PMX-DHP therapy should be considered in cases of sepsis from gram-negative infections.

Endophthalmitis caused by Pantoea agglomerans: clinical features, antibiotic sensitivities, and outcomes

Purpose

To report the clinical findings, antibiotic sensitivities, and visual outcomes associated with endophthalmitis caused by Pantoea agglomerans.

Methods

A consecutive case series of patients with vitreous culture-positive endophthalmitis caused by P. agglomerans from January 1, 1990 to December 31, 2012 at a large university referral center. Findings from the current study were compared to prior published studies.

Results

Of the three study patients that were identified, clinical settings included trauma (n=2) and post-cataract surgery (n=1). Presenting visual acuity was hand motion or worse in all three cases. All isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All isolates were resistant to ampicillin. Initial treatment strategies were vitreous tap and intravitreal antibiotic injection (n=1) and pars plana vitrectomy with intravitreal antibiotic injection (n=2). At last follow-up, one patient had no light perception vision, while the other two had best-corrected visual acuity of 20/200 and 20/400.

Conclusion

All Pantoea isolates were sensitive to ceftazidime, gentamicin, imipenem, and fluoroquinolones. All patients in the current study received at least one intravitreal antibiotic to which P. agglomerans was shown to be sensitive in vitro. In spite of this, the visual outcomes were generally poor.

Identification and antimicrobial resistance of members from the Enterobacteriaceae family isolated from canaries (Serinus canaria)

Abstract: The Enterobacteriaceae family contains potentially zoonotic bacteria, and their presence in canaries is often reported, though the current status of these in bird flocks is unknown. Therefore, this study aimed to identify the most common genera of enterobacteria from canaries (Serinus canaria) and their antimicrobial resistance profiles. From February to June of 2013, a total of 387 cloacal swab samples from eight domiciliary breeding locations of Fortaleza city, Brazil, were collected and 58 necropsies were performed in canaries, which belonged to the Laboratory of Ornithological Studies. The samples were submitted to microbiological procedure using buffered peptone water and MacConkey agar. Colonies were selected according to their morphological characteristics on selective agar and submitted for biochemical identification and antimicrobial susceptibility. A total of 61 isolates were obtained, of which 42 were from cloacal swabs and 19 from necropsies. The most isolated bacteria was Escherichia coli with twenty five strains, followed by fourteen Klebsiellaspp., twelve Enterobacterspp., seven Pantoea agglomerans, two Serratiaspp. and one Proteus mirabilis. The antimicrobial to which the strains presented most resistance was sulfonamides with 55.7%, followed by ampicillin with 54.1% and tetracycline with 39.3%. The total of multidrug-resistant bacteria (MDR) was 34 (55.7%). In conclusion, canaries harbor members of the Enterobacteriaceae family and common strains present a high antimicrobial resistance rate, with a high frequency of MDR bacteria.

[Thorn synovitis: Report of 2 cases]

INTRODUCTION

Thorn synovitis is related to plant or animal thorn punctures. We report two cases of thorn synovitis.

CASE REPORTS

The first patient was a 41-year-old-woman who presented with recurrent arthritis of the right knee after needle fish injury. The immunological tests and cultures were negative. X-rays and MRI showed the foreign bodies in the soft parts on the outer side of the knee. An arthroscopy was performed and the thorn removed. Clinical outcome was favourable with complete symptoms resolution. The second patient was a 58-year-old-man, with a family history of spondylarthritis, who was admitted with a monoarthritis of the left wrist that occurred 10 weeks after palm tree thorn injury. Patient received unsuccessfully antibiotics and anti-inflammatory drugs. Immunological tests and cultures were negative. Wrist ultrasound showed erosive synovitis. Intra-articular lesion removal by arthroscopy allowed favourable outcome.

CONCLUSION

Thorn synovitis diagnosis is based on the discovery of a foreign body. Treatment is based on their removal. Suspicion of infection with deficient pathogen, especially Pantoea agglomerans, remains difficult for the practitioner.

Multiple antibiotic-resistant bacteria on fluted pumpkin leaves, a herb of therapeutic value

Fluted pumpkin (Telfairia occidentalis) is a minimally-processed green leafy vegetable traditionally used for its antianaemic properties in the form of leaf juice without a heating or inactivation step before consumption. The aim of the study was to assess the presence of surface microbiota on T. occidentalis leaves and also to determine the antimicrobial susceptibility of isolated organisms. Bacterial contaminants on 50 samples of T. occidentalis leaves were isolated and characterized using standard biochemical methods and the antimicrobial susceptibility of isolated organisms was determined using the antibiotic disc diffusion assay. The results obtained show that the leaves of T. occidentalis is contaminated with organisms which included Enterobacter agglomerans (25.9%), Proteus vulgaris (24.9%), Klebsiella spp. (2.6%), and Serratia liquefaciens (2.1%). Other bacterial isolates recovered in order of frequency included: Staphylococcus spp. (33.7%), Bacillus spp. (8.3%), and Pseudomonas fluorescens (2.6%). Of the 193 bacterial isolates from the leaves of T. occidentalis samples tested for antimicrobial resistance, all (100%) were found to be resistant to ampicillin, cloxacillin, augmentin, erythromycin, and tetracycline while 96% of the isolates were resistant to cephalothin. Resistance to trimethoprim (93%) and gentamicin (83%) was also observed. Approximately, 22% of the isolates were resistant to ciprofloxacin; however, only 11 (5.8%) were resistant to ofloxacin. Thus, uncooked T. occidentalis is a potential source of highly-resistant epiphytic bacteria which could be opportunistic pathogens in consumers.

Quantitative evaluation of the host-colonizing capabilities of the enteric bacterium Pantoea using plant and insect hosts

The genus Pantoea is a highly diverse group comprising free-living, and both pathogenic and non-pathogenic host-associating species. Pathogenic isolates have been found to infect insects, plants and humans, yet it is unclear whether these isolates have similar pathogenic potential to the free-living environmental populations. Using MLSA of six housekeeping genes, we evaluated the phylogenetic relationships among 115 environmental and clinical (human) isolates representing 11 Pantoea species. An overlay of the location of isolation onto the resulting tree revealed that clinical and environmental isolates are interspersed, and do not form distinctive groups. We then conducted quantitative growth assays of our isolates using maize, onion and fruit flies as hosts. Notably, most clinical isolates were able to grow in both plant hosts often comparably or even better than the environmental isolates. There were no obvious growth or host colonization patterns that could distinguish those isolates with clinical potential. Growth of an isolate in one host could not be predicted based on its performance in another host, nor could host growth be predicted by phylogeny or source of isolation. This work demonstrates that the host-colonizing capabilities of all Pantoea species groups is unpredictable, indicating a broader host range and pathogenic potential than currently assumed.

Annual ryegrass-associated bacteria with potential for plant growth promotion

Annual ryegrass is a fast-growing cool-season grass broadly present in the Portuguese "montado", a typically Mediterranean agro-forestry-pastoral ecosystem. A culture-dependent approach was used to investigate natural associations of this crop with potentially beneficial bacteria, aiming to identify strains suitable for biofertilization purposes. Annual ryegrass seedlings were used to trap bacteria from three different soils in laboratory conditions. Using a nitrogen-free microaerophilic medium, 147 isolates were recovered from the rhizosphere, rhizoplane, and surface-sterilized plant tissues, which were assigned to 12 genera in classes Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Bacilli and Actinobacteria. All isolates were able to grow in the absence of nitrogen and several of them were able to perform in vitro activities related to plant growth promotion. Isolates of the genera Sphingomonas and Achromobacter were found to be the most effective stimulators of annual ryegrass growth under nitrogen limitation (47-92% biomass increases). Major enhancements were obtained with isolates G3Dc4 (Achromobacter sp.) and G2Ac10 (Sphingomonas sp.). The latest isolate was also able to increment plant growth in nitrogen-supplemented medium, as well as the phosphate solubilizer and siderophore producer, G1Dc10 (Pseudomonas sp.), and the cellulose/pectin hydrolyser, G3Ac9 (Paenibacillus sp.). This study represents the first survey of annual ryegrass-associated bacteria in the "montado" ecosystem and unveiled a set of strains with potential for use as inoculants.

Pantoea agglomerans as an indicator of a foreign body of plant origin in cases of wound infection

OBJECTIVE

To investigate the role of Pantoea agglomerans as an infectious agent that causes infection in a wound even after the wound was managed at the emergency department.

METHOD

A retrospective cohort study, reviewing the medical records of patients with traumatic wounds that were admitted to the emergency department from 2007-20 12 and had signs of wound infection for more than I 0 days after the wound was managed. Bacteriological results, clinical picture,and treatment results were obtained.

RESULTS

Nine cases were identified. Pantoea agglomerans was detected in all cases. After 1-2 months of ineffective treatment, patients were hospitalised and surgical revisions of the wounds were performed.In all cases, small foreign bodies of plant origin were detected. After surgical revision, wounds were healed in 2-3 days.

CONCLUSION

In cases of prolonged healing of post-traumatic wounds, the presence of foreign bodies of plant origin infected with Pantoea agglomerans should be taken into account. Removal of such foreign bodies leads to rapid healing of the wounds.

Pantoea agglomerans foreign body-induced septic arthritis

A 4-year-old boy was admitted because of left knee arthritis. Synovial fluid culture yielded Pantoea agglomerans identified by 16S rDNA polymerase chain reaction. Ultrasound examination revealed a foreign body in the synovial fluid. The patient underwent arthroscopy with removal of a thorn. This article highlights the need to search for a foreign body in Pantoea septic arthritis.

Sugarcane growth promotion by the endophytic bacterium Pantoea agglomerans 33.1

The promotion of sugarcane growth by the endophytic Pantoea agglomerans strain 33.1 was studied under gnotobiotic and greenhouse conditions. The green fluorescent protein (GFP)-tagged strain P. agglomerans 33.1::pNKGFP was monitored in vitro in sugarcane plants by microscopy, reisolation, and quantitative PCR (qPCR). Using qPCR and reisolation 4 and 15 days after inoculation, we observed that GFP-tagged strains reached similar density levels both in the rhizosphere and inside the roots and aerial plant tissues. Microscopic analysis was performed at 5, 10, and 18 days after inoculation. Under greenhouse conditions, P. agglomerans 33.1-inoculated sugarcane plants presented more dry mass 30 days after inoculation. Cross-colonization was confirmed by reisolation of the GFP-tagged strain. These data demonstrate that 33.1::pNKGFP is a superior colonizer of sugarcane due to its ability to colonize a number of different plant parts. The growth promotion observed in colonized plants may be related to the ability of P. agglomerans 33.1 to synthesize indoleacetic acid and solubilize phosphate. Additionally, this strain may trigger chitinase and cellulase production by plant roots, suggesting the induction of a plant defense system. However, levels of indigenous bacterial colonization did not vary between inoculated and noninoculated sugarcane plants under greenhouse conditions, suggesting that the presence of P. agglomerans 33.1 has no effect on these communities. In this study, different techniques were used to monitor 33.1::pNKGFP during sugarcane cross-colonization, and our results suggested that this plant growth promoter could be used with other crops. The interaction between sugarcane and P. agglomerans 33.1 has important benefits that promote the plant's growth and fitness.

Bacteremia caused by Pantoea agglomerans at a medical center in Taiwan, 2000-2010

BACKGROUND/PURPOSE

There are only three case reports of adult patients with spontaneous Pantoea agglomerans bacteremia in the English literature. The aim of this study was to investigate clinical and microbiologic characteristics patients of P agglomerans bacteremia.

METHODS

We studied all adult patients with P agglomerans bacteremia at a medical center from 2000 to 2010. The isolates were identified using two commercial identification systems.

RESULTS

Of the 18 patients identified, 72% (n = 13) had active gastroesophageal disease treated with antacids. Two-thirds of patients had indwelling central lines and advanced cancers. None of the removed catheter tips yielded P agglomerans and line persistence was not associated with adverse outcomes. Initial disease severity was low, hypotension was uncommon and no patient died of bacteremia. Recurrence of bacteremia occurred in one patient with deep-seated infection. 16srRNA gene sequencing identified only half of the isolates as P agglomerans. The remaining nine isolates were Enterobacter species for six, Pantoea ananatis for two, and Exiguobacterium profundum for one. There were no significant differences between the characteristics of the subgroup molecularly identified as P agglomernas and the overall group characteristics. Eleven (61%) of the 18 isolates were susceptible to cefazolin, six (33%) susceptible to fosfomycin (MIC ≤ 64 mg/ml). Two isolates had colistin MICs ≥ 4 mg/ml.

CONCLUSION

Bacteremia caused by P agglomerans is associated with gastroesophageal reflux disease and receipt of antacids. 16srRNA gene sequencing should not be used as the sole basis for its identification and we have highlighted the need for another molecular-based technique to conclusively characterize P agglomerans.

Bacterial infective arthritis following a penetrating stick injury of the stifle joint in a dog

An eight-year old, Rottweiler was presented with a chronic non-weight bearing right pelvic limb -lameness and a discharging sinus at the right stifle joint. Fifteen weeks previously a diagnosis of bacterial infective arthritis had been made, presumed attributable to haematogenous spread. Failure to respond to appropriate surgical and medical management resulted in severe joint dysfunction. The poor prognosis for restoration of limb function resulted in limb amputation. Subsequent exploration of the sinus tract and the stifle joint revealed a stick within the craniolateral aspect of the joint. This penetrating stick injury had been responsible for the persistent bacterial infective arthritis.

Spontaneous septicaemia with multi-organ dysfunction--a new face for Pantoe agglomerans?

Pantoe agglomerans (P. agglomerans) is an unusual cause for sepsis in immunocompetent individuals, especially in the absence of characteristic risk factors. We report one such case occurring in a farmer, manifesting with severe illness. The severe nature of illness and the apparently spontaneous origin of septicemia underline the pathogenic potential of this organism. When coupled with the ubiquity of the organism, there is a definite possibility that this disease may become increasingly frequent in the near future, especially in agronomic countries like India. Further studies on the epidemiology and natural history of this disease are required.

Insights into cross-kingdom plant pathogenic bacteria

Plant and human pathogens have evolved disease factors to successfully exploit their respective hosts. Phytopathogens utilize specific determinants that help to breach reinforced cell walls and manipulate plant physiology to facilitate the disease process, while human pathogens use determinants for exploiting mammalian physiology and overcoming highly developed adaptive immune responses. Emerging research, however, has highlighted the ability of seemingly dedicated human pathogens to cause plant disease, and specialized plant pathogens to cause human disease. Such microbes represent interesting systems for studying the evolution of cross-kingdom pathogenicity, and the benefits and tradeoffs of exploiting multiple hosts with drastically different morphologies and physiologies. This review will explore cross-kingdom pathogenicity, where plants and humans are common hosts. We illustrate that while cross-kingdom pathogenicity appears to be maintained, the directionality of host association (plant to human, or human to plant) is difficult to determine. Cross-kingdom human pathogens, and their potential plant reservoirs, have important implications for the emergence of infectious diseases.

Growth inhibition of various Enterobacteriaceae species by the yeast Hansenula anomala during storage of moist cereal grain

Eleven of 13 Enterobacteriaceae species tested grew in moist stored wheat, highlighting a potential risk of this energy-saving airtight storage method. When Hansenula anomala was coinoculated, all Enterobacteriaceae species were significantly inhibited after 2 months of storage, six of them to below the detection limit.

Septic arthritis due to Cellulosimicrobium cellulans

Cellulosimicrobium cellulans has been reported as a rare cause of human pathogenesis. Infections mainly occur in immunocompromised patients and very often are associated with a foreign body. We report the first case of septic arthritis caused by C. cellulans in an immunocompetent patient. Our patient suffered a penetrating palm tree thorn injury to his left knee 8 weeks before admission. Although no foreign objects were found, they were suspected because previous reports suggest a frequent association with this microorganism, and open debridament was performed. Removal of foreign bodies related to this organism must be considered a high-priority treatment in these patients to achieve a complete recovery.

Bacteriophages LIMElight and LIMEzero of Pantoea agglomerans, belonging to the "phiKMV-like viruses"

Pantoea agglomerans is a common soil bacterium used in the biocontrol of fungi and bacteria but is also an opportunistic human pathogen. It has been described extensively in this context, but knowledge of bacteriophages infecting this species is limited. Bacteriophages LIMEzero and LIMElight of P. agglomerans are lytic phages, isolated from soil samples, belonging to the Podoviridae and are the first Pantoea phages of this family to be described. The double-stranded DNA (dsDNA) genomes (43,032 bp and 44,546 bp, respectively) encode 57 and 55 open reading frames (ORFs). Based on the presence of an RNA polymerase in their genomes and their overall genome architecture, these phages should be classified in the subfamily of the Autographivirinae, within the genus of the "phiKMV-like viruses." Phylogenetic analysis of all the sequenced members of the Autographivirinae supports the classification of phages LIMElight and LIMEzero as members of the "phiKMV-like viruses" and corroborates the subdivision into the different genera. These data expand the knowledge of Pantoea phages and illustrate the wide host diversity of phages within the "phiKMV-like viruses."

Diversity and dynamics of bacterial populations during spontaneous sorghum fermentations used to produce ting, a South African food

Ting is a spontaneously fermented sorghum food that is popular for its sour taste and unique flavour. Insight of the microbial diversity and population dynamics during sorghum fermentations is an essential component of the development of starter cultures for commercial production of ting. In this study, bacterial populations associated with spontaneous sorghum fermentations were examined using a culture-independent strategy based on denaturing gradient gel electrophoresis and sequence analysis of V3-16S rRNA gene amplicons, and a culture-dependent strategy using conventional isolation based on culturing followed by 16S rRNA and/or pheS gene sequence analysis. The entire fermentation process was monitored over a 54 h period and two phases were observed with respect to pH evolution and microbial succession. The first phase of the process (0-6h) was characterized by relatively high pH conditions and the presence of Enterococcus mundtii, albeit that this species was only detected with the culture-dependent approach. The second phase of the fermentation process (12-54 h) was characterized by increased acidity and the predominance of a broader range of lactic acid bacteria, including Lactococcus lactis, Lactobacillus fermentum, Lactobacillus plantarum, Lactobacillus rhamnosus, Weissella cibaria, Enterococcus faecalis, and a close relative of Lactobacillus curvatus, as well as some members of the Enterobacteriaceae family. The Lb. curvatus-like species was only detected with PCR-DGGE, while the majority of the other species was only detected using the culture-dependent approach. These findings highlighted the fact that a combination of both approaches was essential in revealing the microbial diversity and dynamics during spontaneous sorghum fermentations.

Biological Warfare of the Spiny Plant Introducing Pathogenic Microorganisms into Herbivore's Tissues

Recently, it has been proposed that plants which have spines, thorns, and prickles use pathogenic aerobic and anaerobic bacteria, as well as pathogenic fungi, for defense against herbivores, especially vertebrates. Their sharp defensive appendages may inject various pathogenic agents into the body of the herbivores by piercing the outer defensive layer of the skin in a type of biological warfare. Here, we review data regarding the various bacterial taxa found on spines, as well as the medical literature regarding infections by bacteria and fungi related to spine injuries. We also present new evidence that, concerning the microbial flora, spines belonging to the palm tree Washingtonia filifera are probably a different habitat than the nondefensive green photosynthetic leaf surfaces. In addition, many plant species have microscopic internal and external spines (raphids and silica needles) which can also wound large herbivores as well as insects and other small invertebrate herbivores that usually attack in between large spines, prickles, and thorns. The large spines and sharp microscopic structures may inject not only the microorganisms that inhabit them into the herbivore's tissues, but also those preexisting on the skin surface or inside the digestive system of the herbivores and on the surface of nonspiny plant parts. A majority of the spiny plants visually advertise their spiny nature, a characteristic known as aposematism (warning coloration). The pathogenic microorganisms may sometimes be much more dangerous than the physical wounds inflicted by the spines. In accordance, we suggest that the possible cooperation or even just the random association of spines with pathogenic microorganisms contributed to the evolution of aposematism in spiny plants and animals. The role of these sharp defensive structures in inserting pathogenic viruses into the tissues of herbivores was never studied systematically and deserves special attention.

Application of whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry for rapid identification and clustering analysis of pantoea species

Pantoea agglomerans is an ecologically diverse taxon that includes commercially important plant-beneficial strains and opportunistic clinical isolates. Standard biochemical identification methods in diagnostic laboratories were repeatedly shown to run into false-positive identifications of P. agglomerans, a fact which is also reflected by the high number of 16S rRNA gene sequences in public databases that are incorrectly assigned to this species. More reliable methods for rapid identification are required to ascertain the prevalence of this species in clinical samples and to evaluate the biosafety of beneficial isolates. Whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) methods and reference spectra (SuperSpectrum) were developed for accurate identification of P. agglomerans and related bacteria and used to detect differences in the protein profile within variants of the same strain, including a ribosomal point mutation conferring streptomycin resistance. MALDI-TOF MS-based clustering was shown to generally agree with classification based on gyrB sequencing, allowing rapid and reliable identification at the species level.

Retained Hawthorn fragment in a child's foot complicated by infection: diagnosis and excision aided by localization with ultrasound

Puncture wounds in children are very common and often result in foreign body retention. Organic materials in the form of plant thorns present problems in identification and localization because they are not visualized with plain radiographs. A case of a 10-year-old girl with a small piece of retained hawthorn is presented. Correct diagnosis and treatment were delayed because of misinterpretation of magnetic resonance image studies. Ultrasound ultimately located the foreign body, and assisted in its excision. Plant thorns may be toxic and produce an intense local inflammatory response. In the case described in this article, deep infection caused by Enterobacter cloacae and Pantoea agglomerans was associated with the retained thorn. The small size of the foreign body, misinterpretation of diagnostic images, and the deep infection highlight the challenges that can be encountered by physicians managing puncture wounds in children.

Bacteria colonizing root nodules of wild legumes exhibit virulence-associated properties of mammalian pathogens

Bacteria not proficient in nitrogen fixing symbiosis were proven able to invade root nodules of three wild legumes of the genus Hedysarum in Algeria and to be multiplying in these in place of the natural rhizobium symbionts. The involved species featured taxa known as human pathogens including: Enterobacter cloacae, Enterobacter kobei, Escherichia vulneris, Pantoea agglomerans and Leclercia adecarboxylata. A direct screening of the phenotypic determinants of virulence using human cultured cells tested positive for the traits of cytotoxicity, vital stain exclusion and adhesion to epithelia. Antibiogram analyses revealed also a complex pattern of multiple antibiotic resistances. The data suggest that legume root nodules can be a site of survival and of active multiplication for populations of mammalian pathogens, which could thus alternate between the target animal and a number of neutral plant hosts. The worldwide distribution of as yet uninvestigated legumes raises the concern that these represent a general niche that could enhance the hazards posed by microorganisms of clinical nature.

Changes in the bacterial populations of the highly alkaline saline soil of the former lake Texcoco (Mexico) following flooding

Flooding an extreme alkaline-saline soil decreased alkalinity and salinity, which will change the bacterial populations. Bacterial 16S rDNA libraries were generated of three soils with different electrolytic conductivity (EC), i.e. soil with EC 1.7 dS m(-1) and pH 7.80 (LOW soil), with EC 56 dS m(-1) and pH 10.11 (MEDIUM soil) and with EC 159 dS m(-1) and pH 10.02 (HIGH soil), using universal bacterial oligonucleotide primers, and 463 clone 16S rDNA sequences were analyzed phylogenetically. Library proportions and clone identification of the phyla Proteobacteria, Actinobacteria, Acidobacteria, Cyanobacteria, Bacteroidetes, Firmicutes and Cloroflexi showed that the bacterial communities were different. Species and genera of the Rhizobiales, Rhodobacterales and Xanthomonadales orders of the alpha- and gamma-subdivision of Proteobacteria were found at the three sites. Species and genera of the Rhodospirillales, Sphingobacteriales, Clostridiales, Oscillatoriales and Caldilineales were found only in the HIGH soil, Sphingomonadales, Burkholderiales and Pseudomonadales in the MEDIUM soil, Myxococcales in the LOW soil, and Actinomycetales in the MEDIUM and LOW soils. It was found that the largest diversity at the order and species level was found in the MEDIUM soil as bacteria of both the HIGH and LOW soils were found in it.

Phylogeny and identification of Pantoea species and typing of Pantoea agglomerans strains by multilocus gene sequencing

Pantoea agglomerans and other Pantoea species cause infections in humans and are also pathogenic to plants, but the diversity of Pantoea strains and their possible association with hosts and disease remain poorly known, and identification of Pantoea species is difficult. We characterized 36 Pantoea strains, including 28 strains of diverse origins initially identified as P. agglomerans, by multilocus gene sequencing based on six protein-coding genes, by biochemical tests, and by antimicrobial susceptibility testing. Phylogenetic analysis and comparison with other species of Enterobacteriaceae revealed that the genus Pantoea is highly diverse. Most strains initially identified as P. agglomerans by use of API 20E strips belonged to a compact sequence cluster together with the type strain, but other strains belonged to diverse phylogenetic branches corresponding to other species of Pantoea or Enterobacteriaceae and to probable novel species. Biochemical characteristics such as fosfomycin resistance and utilization of d-tartrate could differentiate P. agglomerans from other Pantoea species. All 20 strains of P. agglomerans could be distinguished by multilocus sequence typing, revealing the very high discrimination power of this method for strain typing and population structure in this species, which is subdivided into two phylogenetic groups. PCR detection of the repA gene, associated with pathogenicity in plants, was positive in all clinical strains of P. agglomerans, suggesting that clinical and plant-associated strains do not form distinct populations. We provide a multilocus gene sequencing method that is a powerful tool for Pantoea species delineation and identification and for strain tracking.

Case report: subacute synovitis of the knee after a rose thorn injury: unusual clinical picture

Synovitis secondary to penetrating plant thorn injuries is not frequently reported. Historically, it is considered aseptic and treated with removal of the intraarticular foreign body and affected synovial lining. We report a 57-year-old healthy man who was admitted 2 weeks after being injured by a rose (Rosacea) thorn with subacute and mild synovitis with effusion of his right knee. No intraarticular foreign body was retained. Pantoea agglomerans was identified in the synovial fluid. Contrary to former teaching, effusions from joints violated by thorns should not be presumed sterile. Bacterial growth is reported infrequently, but when reported, Pantoea agglomerans is the most common organism found. We recommend removal of foreign bodies if present, arthroscopic total synovectomy, and beginning empiric antibiotic treatment with coverage against gram-negative enteric pathogens in all cases of thorn synovitis until the results of culture specimens are known. Improved physician awareness can result in more rapid diagnosis and improved clinical outcome in affected individuals.

Pantoea agglomerans bacteremia in a 65-year-old man with acute myeloid leukemia: case report and review

A 65-year-old man with a recent history of acute leukemia was admitted with complaints of chills and rigors. He had a long-standing Hickman catheter which was removed following the isolation of a gram negative rod later identified as Pantoea agglomerans. The patient recovered with antimicrobial therapy. Pantoea species are rare causes of clinically relevant infections.

Identification, antimicrobial resistance profiles, and virulence of members from the family Enterobacteriaceae from the feces of yellow-headed blackbirds (Xanthocephalus xanthocephalus) in North Dakota

Public pressure to reduce or eliminate antimicrobials as ingredients of feed for poultry and other agricultural animals is mounting, primarily due to the fear of multidrug-resistant bacteria in clinical infections in both animals and humans. Exploration of the occurrence of antibiotic resistance in the gut flora of wildlife avian flocks that presumptively do not receive antimicrobials will determine the rate of resistance in a naïve population. Fecal samples collected from a healthy population of the yellow-headed blackbirds (YHB) (Xanthocephalus xanthocephalus) in North Dakota were cultured to determine what genera and species of gram-negative facultative anaerobic bacteria these wild birds carry in their intestinal flora and to evaluate the antimicrobial susceptibility profiles. Isolates of Escherichia coli were further characterized for the presence of putative virulence factors and for pathogenic potential using the chicken embryo lethality assay (ELA). The ELA was performed in chicken embryos with challenges at both 12 days and 16 days of incubation to determine whether the 16-day-old embryos were better able to fight the infection and subsequent disease and also to determine whether the ELA could distinguish between primary and secondary avian Escherichia coli pathogens. After screening 33 isolates from the 21 fecal samples, only two E. coli isolates were identified. The predominant genus and species of bacterium identified was Pantoea agglomerans. Collectively, 12 of the 33 isolates (36%) exhibited no resistance to any antimicrobial tested. However, several multidrug-resistant isolates of varying genera were identified. Among the antimicrobial resistances observed, the most common was to ampicillin (60%), followed by cephalothin (33%). Neither E. coli isolate belonged to serogroups that are notorious for causing major outbreaks of colibacillosis in poultry, and only one E. coli isolate retained resistance to any antibiotics; nevertheless, the ELA results indicate that at least one of these E. coli may be a primary pathogen of chickens. This study demonstrates that antibiotic resistance occurs in the gut flora of natural populations of YHB despite the absence of antibiotic pressure. In addition, these results indicate that YHB will harbor E. coli isolates that are potentially pathogenic in poultry. However, these E. coli isolates are not a significant reservoir for multiple antibiotic resistances nor are they widespread in the population of YHB surveyed in North Dakota.

Pantoea agglomerans, a plant pathogen causing human disease

We present 53 pediatric cases of Pantoea agglomerans infections cultured from normally sterile sites in patients seen at a children's hospital over 6 years. Isolates included 23 from the bloodstream, 14 from abscesses, 10 from joints/bones, 4 from the urinary tract, and 1 each from the peritoneum and the thorax. P. agglomerans was most associated with penetrating trauma by vegetative material and catheter-related bacteremia.