Isolation of a Pantoea dispersa-like strain fron a 71-year-old woman with acute myeloid leukemia and multiple myeloma

Whole genome analysis of Pantoea species identified from sepsis patients in selected Ethiopian referral hospitals: emerging pathogens

BACKGROUND

The burden of sepsis worsens due to the continuation of emerging pathogens such as multidrug-resistant Pantoea species.

METHODS

A multicenter study was conducted between October 2019 and September 2020 at four hospitals located in central, southern, and northern parts of Ethiopia. A total of 1416 sepsis patients were recruited and blood cultures were performed. At each study site, positive cultures were characterized by their colony characteristics, gram stain, and conventional biochemical tests. All Pantoea species were identified using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI TOF) and subjected to whole genome sequencing (WGS) using Illumina HiSeq 2500. The phylogeny structure of Pantoea isolates was calculated using IQ-TREE v1.6.12 from single-nucleotide polymorphisms detected by Snippy v.4.6.0 and filtered by Gubbins v.2.3.4. Average nucleotide identity was estimated by using OrthoANI v.0.93.1 on Shovill v.1.1.0 assemblies. Antimicrobial resistance genes and plasmid replicons were detected using ARIBA v.2.14.6. Phylogenetic trees were visualized using iTOLv.6.5.2.

RESULTS

Multiple Pantoea species include: P. dispersa (n = 19), P. septica (n = 1), and a novel Pantoea spp. (n = 1), were identified among sepsis patients. All P. dispersa isolates and the novel Pantoea species were isolated at Dessie Referral Hospital and displayed phylogenetic clonality, including the ubiquity of an IncM1 plasmid and identical antimicrobial resistance (AMR) gene profiles, encoding blaCTX-M-15, blaTEM-1D, blaSCO-1, and aac(3)-lla. The novel Pantoea spp. isolate harboured blaCTX-M-9 and blaTEM-1D and carried an IncN3 plasmid replicon. The P. septica was isolated at Tikur Anbessa Specialized Hospital in Addis Ababa and carried no detectable acquired AMR genes.

CONCLUSION

The emerging Pantoea spp. carrying multiple AMR genes were identified from sepsis patients. Implementation of strong infection prevention strategies and building surveillance capacity with advanced bacteriology laboratories capable of identifying multidrug-resistant emerging pathogens is strongly recommended.

Pantoea dispersa peritoneal dialysis catheter-related infection

Enteric gram-negative bacteria-associated peritoneal dialysis (PD) peritonitis is common. These organisms are such as Escherichia coli, Klebsiella and Enterobacter species. Pantoea dispersa belongs to the order Enterobacterales, it has known benefits and a role in agricultural and environmental biotechnology. Pantoea dispersa, although still relatively rare, is being increasingly recognised to cause human infections. We are reporting a case of PD peritonitis caused by Pantoea dispersa in a kidney failure patient on continuous ambulatory peritoneal dialysis (CAPD). His peritonitis was treated well with intraperitoneal antibiotics and the patient can resume his CAPD therapy. The increasing reports of Pantoea dispersa-related human infections warrant concerns, both in immunocompromised and immunocompetent patients.

Disseminated Lodderomyces elongisporus and Pantoea dispersa: A Rare Dual Infection in an Immunocompromised Patient

With the advancement of modern medicine and the prolonged survival of critically ill patients, unusual organisms are increasingly emerging. Initially found in the environment, these rare organisms started presenting as human pathogens, causing significant morbidity and mortality. Here, we present a rare case of disseminated Lodderomyces elongisporus fungemia and Pantoea dispersa bacteremia in a patient with parapneumonic effusion and ruptured liver abscess. This yeast was identified using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF). Although this organism has no antifungal breakpoint, the isolate shows low minimum inhibitory concentration (MIC) to a wide range of antifungals. The importance of effective communication between microbiologists and clinicians and early referral to the infectious disease team was also highlighted in this case for prompt treatment.

Disruption and recovery of outdoor bioaerosols before, during, and after the COVID-19 outbreak at a campus in Central China: pathogen composition, particle size distribution, influencing factors, and exposure risk

Before (2019), during (2020), and after (2021) the COVID-19 outbreak, different response methods and measures were taken on campuses to control the spread of COVID-19 within schools. These response methods may have changed the outdoor bioaerosol characteristics, which may affect staff and student health. Therefore, we analyzed the bacterial concentrations, particle size distribution, microbial populations, exposure risks, and environmental influences of bioaerosols at a campus before, during, and after the COVID-19 outbreak. This study used eight-stage Andersen samplers to collect and analyze culturable bacteria in bioaerosols from various locations, high-throughput sequencing to analyze microbial species, principal component analysis to compare differences in samples, RDA to investigate the effects of environmental factors on bioaerosols, and hazard quotient (HQ) and BugBase to evaluate human health risks. The study findings revealed that average bacterial concentrations before, during, and after COVID-19 were 75 CFU m-3, 136 CFU m-3, and 78 CFU m-3, respectively. Moreover, the average percentage of bacteria attached to PM2.5 was 49.2%, 42.7%, and 29.9%, respectively. High-throughput sequencing revealed that species composition changed significantly during the three years of COVID-19. The proportion of Pantoea and Bacillus increased with the development of COVID-19 and these became the dominant strains after COVID-19, whereas Pseudomonas had the maximum proportion during COVID-19. Both risk assessment and BugBase phenotype prediction results indicated that the potential pathogenic risk was the highest in the outdoor environment of the campus during COVID-19 and that bioaerosol contamination was the most severe compared to the outdoor bioaerosol characteristics of the campus recovered after COVID-19.

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.

Unveiling the duality of Pantoea dispersa: A mini review

Pantoea dispersa is a Gram-negative bacterium that exists in a variety of environments and has potential in many commercial and agricultural applications, such as biotechnology, environmental protection, soil bioremediation, and plant growth stimulation. However, P. dispersa is also a harmful pathogen to both humans and plants. This "double-edged sword" phenomenon is not uncommon in nature. To ensure survival, microorganisms respond to both environmental and biological stimuli, which could be beneficial or detrimental to other species. Therefore, to harness the full potential of P. dispersa, while minimizing potential harm, it is imperative to unravel its genetic makeup, understand its ecological interactions and underlying mechanisms. This review aims to provide a comprehensive and up-to-date overview of the genetic and biological characteristics of P. dispersa, in addition to potential impacts on plants and humans, as well as to provide insights into potential applications.

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.

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

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

Nosocomial bloodstream infection pathogen Pantoea dispersa: a case report and literature review

Pantoea dispersa is a gram-negative bacterium frequently found in plants, soil, and water. The genus Pantoea is a rare pathogen in human infectious diseases. The known susceptible populations include infants and postoperative and immunocompromised patients. To date, there are no reports of nosocomial bloodstream infection due to P. dispersa following chest puncture. A 72-year-old Chinese woman suffering from chest distress was found to be blood culture positive for a gram-negative bacterium. The organism was identified as P. dispersa through VITEK 2, MALDI-TOF MS, and 16S rRNA gene sequencing. Although cefoperazone-sulbactam and imipenem were used for treatment, the patient died four days later. To the best of our knowledge, this is the first case of nosocomial bloodstream infection caused by P. dispersa in China. We hope that this article would help clinicians understand better the potential pathogenicity of this pathogen.

Characteristics and accurate identification of Pantoea dispersa with a case of spontaneous rupture of hepatocellular carcinoma in China: A case report

INTRODUCTION

Pantoea dispersa belongs to the genus Pantoea, which is isolated from Enterobacteriaceae. It has been reported to cause some kinds of infections, but there are few detailed studies on it, especially its characteristics and identification methods, which has caused a lot of trouble in clinical work.

PATIENT CONCERNS

A 51-year-old Chinese man was admitted to our hospital with a 7-hour history of progressive abdominal pain. He was previously diagnosed with liver cirrhosis secondary to chronic hepatitis B infection and hepatocellular carcinoma. An emergency hepatic artery embolization for hemostasis was performed under local anesthesia. Forty-eight hours later, the patient presented sudden onset of high fever up to 39.0 °C and chill.

DIAGNOSIS

Morphological and phenotypic profiles were performed for preliminary identification for P dispersa. The biochemical features were obtained by VITEK 2 Test Kit. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and 16S ribosomal RNA sequencing were performed to accurately identify P dispersa.

INTERVENTION

Antibiotic therapy of intravenous ceftazidime was started empirically. The antibiotic treatment was switched to intravenous cefepime at the same time because of suspected ceftazidime treatment failure and microbiological sensitivity.

OUTCOMES

The patient remained afebrile, and the second blood culture results were negative. Chest X-ray was normal as well. In order to control the progression of the hepatic lesion, transarterial chemoembolization was performed under local anesthesia. After completion of 14 days of antibiotic treatment, the patient was discharged with no signs of recurrence.

CONCLUSION

P dispersa, a gram-negative bacterium rod, were facultative anaerobic, which displayed yellow pigmentation, round, raised, smooth on culture plates. Conventional analysis was difficult to complete its identification. With biochemical tests, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and 16S ribosomal RNA sequencing, P dispersa can be accurately identified. It will help physicians understand the related clinical manifestations and make timely and effective treatment for patients.

Molecular validation of clinical Pantoea isolates identified by MALDI-TOF

The Enterobacterial genus Pantoea contains both free-living and host-associating species, with considerable debate as to whether documented reports of human infections by members of this species group are accurate. MALDI-TOF-based identification methods are commonly used in clinical laboratories as a rapid means of identification, but its reliability for identification of Pantoea species is unclear. In this study, we carried out cpn60-based molecular typing of 54 clinical isolates that had been identified as Pantoea using MALDI-TOF and other clinical typing methods. We found that 24% had been misidentified, and were actually strains of Citrobacter, Enterobacter, Kosakonia, Klebsiella, Pseudocitrobacter, members of the newly described Erwinia gerundensis, and even several unclassified members of the Enterobacteriaceae. The 40 clinical strains that were confirmed to be Pantoea were identified as Pantoea agglomerans, Pantoea allii, Pantoea dispersa, Pantoea eucalypti, and Pantoea septica as well as the proposed species group, Pantoea latae. Some species groups considered largely environmental or plant-associated, such as P. allii and P. eucalypti were also among clinical specimens. Our results indicate that MALDI-TOF-based identification methods may misidentify strains of the Enterobacteriaceae as Pantoea.

Pantoea dispersa bacteremia in an immunocompetent patient: a case report and review of the literature

Background

Pantoea is a Gram-negative, non-encapsulated, non-spore-forming, ubiquitous straight rod which can be isolated from geographical and ecological sources such as plant surfaces, buckwheat seeds, human feces, and the environment. The genus Pantoea is a rare pathogen in a clinical setting, and is divided into 20 different species such as Pantoea agglomerans, Pantoea ananatis, Pantoea deleyi, Pantoea dispersa, Pantoea septica, Pantoea stewartii or Pantoea rwandensis. Pantoea dispersa has been reported to cause other infections, including respiratory infections, neonatal sepsis, and bloodstream infections. We report a case of Pantoea dispersa bacteremia caused by acute cholangitis. This is the first case report of Pantoea dispersa bacteremia caused by acute cholangitis as far as we had searched.

Case presentation

A 38-year-old Japanese woman suffered from acute cholangitis; a blood culture showed that Gram-negative rod was positive. The treatment was successful with intravenously administered meropenem, and it was switched to orally administered levofloxacin according to microbiological susceptibility. The organism was identified as Pantoea dispersa by both genetic investigation by 16S ribosomal RNA and additional biochemical tests. To the best of our knowledge, this is the first case report of Pantoea dispersa bacteremia caused by acute cholangitis.

Conclusion

The epidemiology and clinical features of Pantoea dispersa are still unknown. More cases of infections caused by Pantoea dispersa might be revealed with advancing technical methods, such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or 16S ribosomal RNA analysis. Physicians must know that a variety of infections caused by Pantoea dispersa could occur in immunocompromised as well as immunocompetent patients.

Pantoea dispersa: Is it the Next Emerging "Monster" in our Intensive Care Units? A Case Report and Review of Literature

Hospital-acquired infections and their consequences are the main cause of morbidity/mortality in critically ill and immunocompromised patients. It becomes interesting when an unusual and uncommon microorganism is found to be the causative agent, rather than the known commensals and opportunists. We present such a case, when a multiparous female, in post lower uterine segment cesarean section period presented with fulminant septic shock, hepatic failure, coagulopathy, and ventilator-associated pneumonitis. The organism grown in the tracheal secretions turned out to be an uncommon, unusual Gram-negative Coccobacillus by the name of Pantoea dispersa, resistant to almost all the conventional antimicrobial agents. In spite of all the efforts, the patient could not be saved. However, the case has opened up a virtual “Pandora's box” of questions. Are these microorganisms, known plant pathogens, really harmful to humans? Are they commensals or virulent opportunists? Are we once again on the way to a new “Acinetobacter,” like near-epidemic? This is an attempt to try and find some insight about this presently uncommon and not well known genus of Pantoea! We have tried to trace and review the related available literature in the clinical medicine.

A wide diversity of Pantoea lineages are engaged in mutualistic symbiosis and cospeciation processes with stinkbugs

Pantoea are emerging as widespread bacteria engaged in associations with a variety of hosts, including plants, insects and humans. Recently, mutualistic Pantoea gut symbionts have also been reported in pentatomid stinkbugs. In the present study, we examine the incidence and evolutionary history of these Pantoea symbionts in pentatomid stinkbug populations from 14 species, characterising the processes that shape their diversity. We identify midgut crypts of pentatomid stinkbugs as harboring a remarkable diversity of Pantoea. Present in 10 of the 14 sampled host species, multi-locus typing revealed the presence of 10 novel Panteoa lineages, all highly differentiated from the known Panteoa species. Rearing experiments of two pentatomid stinkbug species confirmed that these novel Panteoa are maternally inherited through egg smearing and engaged in mutualistic interactions with their hosts. Phylogenetic investigations further revealed that the Pantoea evolutionary history in pentatomid stinkbugs was notably complex: it has been shaped not only by horizontal transfers with frequent host turnover but also by strict vertical transmission over long evolutionary periods, resulting in host-symbiont codiversification.

Pantoea dispersa: an unusual cause of neonatal sepsis

Neonatal septicemia is the most important cause of neonatal mortality. A wide variety of bacteria both aerobic and anaerobic can cause neonatal sepsis. Genus Pantoea is a member of Enterobacteriaceae family that inhabits plants, soil and water and rarely causes human infections, however, Pantoea dispersa has not been reported as a causative organism for neonatal sepsis. We hereby report two neonates with early onset sepsis caused by Pantoea dispersa. Early detection and appropriate antibiotic therapy can improve overall outcome of this rare infection in neonates.

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.

Nosocomial outbreak of Pantoea agglomerans bacteraemia associated with contaminated anticoagulant citrate dextrose solution: new name, old bug?

We describe an outbreak investigation of Pantoea agglomerans bacteraemia associated with anticoagulant citrate-dextrose 46% (ACD) solution prepared in-house. A healthy man presented with septic shock during plasmapheresis for granulocyte donation. The solution used for priming and blood samples were sent for culture. Identification of the isolate to species level was performed by gyrB sequencing. Typing was performed by pulsed-field gel electrophoresis (PFGE). In total, eight cases were identified during a three-week period. P. agglomerans was also cultured from six ACD solution bags. Isolates from patients and ACD bags were identical by PFGE. All isolates were susceptible to ampicillin, cephazolin, gentamicin, ciprofloxacin, cefepime and imipenem.

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.

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.

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.

Pantoea peritonitis in a patient receiving chronic ambulatory peritoneal dialysis

Pantoea agglomerans is usually the most common organism transmitted through plant thorn injuries. This report is of a female patient maintained on chronic ambulatory peritoneal dialysis (CAPD) who developed peritonitis attributed to P. agglomerans. Peritonitis is an uncommon complication of P. agglomerans and there is no previous report of peritonitis associated with this organism in a CAPD patient. The source of infection was thought to be due to rose-thorn injury. Antibiotic therapy with ceftazidime and amikacin i.p. led to a clinical improvement, with disappearance of the organism in the peritoneal fluid.

Pseudooutbreak of Pantoea species bacteremia associated with contaminated cotton pledgets

A total of 22 isolates of Pantoea strains, unusual causative agents of clinical infection, was isolated from blood cultures from 9 patients and 1 ear swab from 1 of the patients within a period of 1 month in a tertiary-care hospital. Pseudooutbreak was suspected because specimens were collected from a limited number of places and the patients did not show consistent signs or symptoms of bacterial sepsis. Enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR) and partial 16S ribosomal DNA sequencing were performed to determine the clonal relationship among the isolates. Screening environmental cultures revealed that cotton pledgets were contaminated with Pantoea species. Molecular typing suggested that 2 different clones of Pantoea strains were responsible for the pseudooutbreak. Cotton materials may be a possible source of Pantoea pseudooutbreak. Molecular typing is useful for investigating epidemics and identifying unusual clinical isolates.

Bacteremic infection with Pantoea ananatis

A 73-year-old man was hospitalized for dyspnea and bilateral ankle edema. During his hospital stay he presented anal hemorrhage and developed a high fever after colonoscopy. A set of aerobic and anaerobic blood culture bottles yielded a pure culture of gram-negative rods, susceptible to all antibiotics tested. The API20E code was 1005133, resulting in a very good identification as Pantoea sp. Subsequent sequencing of the 16S rRNA gene revealed a final identification as Pantoea ananatis. The patient was given intravenous and oral therapy with piperacillin-tazobactam and ofloxacin and recovered completely from his infection.