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

Pantoea agglomerans: A rare infectious outbreak affecting maintenance hemodialysis patients in a tertiary care hospital

BACKGROUND

Pantoea agglomerans is an environmental pathogen known to cause infection in immunocompromised individuals, particularly after thorn injuries. However, previous data showed few cases of human disease caused by contaminated medical products such as parenteral nutrition, anesthetic agents, blood, and peritoneal dialysis solutions. Infection in hemodialysis patients is rare. In this study, we presented a detailed account of several hemodialysis patients infected with this contagious pathogen and compared them with noninfected dialysis patients.

METHODS

We retrospectively reviewed the hospital records of 105 hemodialysis patients. Seventeen of 105 patients were diagnosed with P. agglomerans infection. We carefully analyzed their entire in-hospital course.

RESULTS

Among infected patients, 52.9% were male with a median age of 49 (IQR: 32-66) years. Compared to the noninfected patients, age below 50 years, prior kidney transplantation, prior immunosuppression and antibiotics use, and dialysis via a tunneled vascular catheter were the significant epidemiological features. Despite negative microbiological investigations, we suspect the possible infectious spread via infected central venous catheter was the likely infectious source. Most importantly, all patients responded well to intravenous antibiotics. Only two patients required the removal of the tunneled catheter. Their mortality rate was 0%.

CONCLUSION

P. agglomerans infection, although considered rare, is becoming increasingly prevalent among dialysis patients. Its occurrence must be appraised as an infectious outbreak rather than mere contamination. Prompt treatment, source identification, and early implementation of preventive strategies should always be the goal to curtail this infection at an early stage.

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.

Physiological and transcriptomic analyses of response of walnuts (Juglans regia) to Pantoea agglomerans infection

Introduction

Walnut blight is a serious bacterial disease that affects the yield and quality of walnuts. Pantoea agglomerans is one of the main causative agents of walnut blight. However, there have been few studies on the response of walnuts to P. agglomerans infection.

Methods

In this study, the soluble sugar, photosynthesis, antioxidant enzyme activities, and secondary metabolites were measured, and the transcriptomic analysis was performed to determine the response of walnut tissue cultures to P. agglomerans infection.

Results

After pathogen inoculation, the soluble sugar content decreased, and photosynthesis was inhibited. Antioxidant enzyme (superoxide dismutase and peroxidase) activities and secondary metabolites (phenol and flavonoid) contents increased, especially in the early stages of inoculation. Transcriptomic analysis revealed that the phenylpropanoid biosynthesis pathway is induced after infection, and pathogen infection promotes ABA and ethylene signal transduction and inhibits auxin signaling. In addition, SA and JA-related gene expression was altered after inoculation with P. agglomerans, and the FLS- and calcium-mediated disease resistance signaling pathways were activated. Furthermore, our results suggested an involvement of the R-protein RPM-mediated disease resistance pathway in the response of walnuts to bacterial infections.

Discussion

Our findings indicated that phenylpropanoid biosynthesis, hormone signal transduction, and plant-pathogen interaction have key roles in pathogenic inoculation, which provide insights into the molecular mechanisms in the response of walnuts to P. agglomerans infection.

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.

Antimicrobial Susceptibility Profile of Pathogenic and Commensal Bacteria Recovered from Cattle and Goat Farms

The use of antibiotics in food animals results to antimicrobial resistant bacteria that complicates the ability to treat infections. The purpose of this study was to investigate the prevalence of pathogenic and commensal bacteria in soil, water, manure, and milk from cattle and goat farms. A total of 285 environmental and 81 milk samples were analyzed for Enterobacteriaceae by using biochemical and PCR techniques. Susceptibility to antibiotics was determined by the Kirby-Bauer disk diffusion technique. A total of 15 different Enterobacteriaceae species were identified from goat and cattle farms. Manure had significantly higher (p < 0.05) Enterobacteriaceae (52.0%) than soil (37.2%), trough water (5.4%), and runoff water (5.4%). There was a significant difference (p < 0.05) in Enterobacteriaceae in goat milk (53.9%) and cow milk (46.2%). Enterobacteriaceae from environment showed 100% resistance to novobiocin, erythromycin, and vancomycin E. coli O157:H7, Salmonella spp., Enterococcus spp., and Listeria monocytogenes displayed three, five, six, and ten. AMR patterns, respectively. NOV-TET-ERY-VAN was the most common phenotype observed in all isolates. Our study suggest that cattle and goat farms are reservoirs of multidrug-resistant bacteria. Food animal producers should be informed on the prudent use of antimicrobials, good agricultural practices, and biosecurity measures.

Cross-Over Pathogenic Bacteria Detected in Infected Tomatoes (Solanum lycopersicum L.) and Peppers (Capsicum annuum L.) in Bulgaria

The ability of certain human pathogens to adapt to plants without losing their virulence toward people is a major concern today. Thus, the aim of the present work was the investigation of the presence of cross-over pathogenic bacteria in infected tomato and pepper plants. The objects of the study were 21 samples from seven different parts of the plants and three from tomato rhizosphere. In total, 26 strains were isolated, identified by MALDI-TOF, and phenotypically characterized. The PCR amplification of the rpoB gene was applied as an approach for the rapid detection of cross-over pathogens in plant samples. A great bacterial diversity was revealed from tomato samples as nine species were identified (Leclercia adecarboxylata, Pseudesherichia vulneris, Enterobacter cancerogenus, Enterobacter cloacae, Enterobacter bugandensis, Acinetobacter calcoaceticus, Pantoea agglomerans, Pantoea ananatis, and Pectobacterium carotovorum). Polymicrobial contaminations were observed in samples T2 (tomato flower) and T10 (tomato fruit). Five species were identified from pepper samples (P. agglomerans, L. adecarboxylata, Pseudomonas sp., Pseudomonas putida, and Enterococcus sp.). Antibiotic resistance patterns were assigned in accordance with EFSA recommendations. All isolates showed varying resistance to the tested antibiotics. The genetic basis for the phenotypic antibiotic resistance was not revealed. No genes for the virulence factors were found among the population. To our knowledge, this is the first overall investigation of tomato and pepper cross-over pathogenic bacterial populations in Bulgaria.

Pantoea agglomerans Bacteremia: A Rare Case of Bacteremia in an Immunocompetent Four-Year-Old Child

Pantoea agglomerans is primarily an environmental and agricultural organism that rarely causes disease in healthy individuals. We present a case of P. agglomerans bacteremia in an immunocompetent four-year old boy without comorbidities who presented with fever and increased inflammatory markers. As the exact source of bacteremia could not be established, our case was considered to be an event of primary blood stream infection.

Successful Treatment of Pantoea agglomerans Bacteremia Using Oral Antibiotics

A 30-year-old female with a medical history of gastrointestinal reflux and intravenous methamphetamine use was admitted to the hospital with complaints of fever and chills. Pantoae agglomerans was isolated in one out of two blood cultures. Although information was limited about the duration and efficacy of oral antibiotics to treat this type of infection, the patient recovered with oral antibiotic treatment following a short course of intravenous antibiotics.

Carbapenem-resistant IMP-1-producing Pseudocitrobacter vendiensis emerging in a hemodialysis unit

Hemodialysis patients are at high risk for bloodstream infections associated with highest morbidity and mortality rates. Bacterial species not commonly related to such infections has been hardly identified by traditional methods. Pseudocitrobacter is a novel genus of the order Enterobacterales that is associated with carbapenemase genes and nosocomial infection. In this context, we have investigated nine cases of bloodstream infections by carbapenem-resistant Gram-negative bacilli in patients assisted at a hemodialysis unit in Brazil. The infections were caused by a metallo-β-lactamase (IMP-1)-producing clone (> 90% XbaI-PFGE similarity) of Pseudocitrobacter vendiensis, displaying a multidrug-resistant profile to broad-spectrum cephalosporins, carbapenems, chloramphenicol, and trimethoprim-sulfamethoxazole. S1-PFGE and Southern blot hybridization revealed that bla_IMP-1 was carried by a 200-kb IncC/ST3 plasmid. Patients were successfully treated with amikacin, and strict disinfection procedures and hand washing protocols were reinforced. We report the emergence of P. vendiensis, a recently described species of the genus, in bloodstream infections of patients undergoing hemodialysis. Considering the epidemic potential of carbapenemase-producing Enterobacterales in hospital settings, surveillance of this emerging pathogen is of utmost importance.

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.

Pantoea agglomerans: An Elusive Contributor to Chronic Obstructive Pulmonary Disease Exacerbation

The ubiquitously present gram-negative bacteria Pantoea agglomerans is not a commonly known human pathogen. Recently, increasing recognition of the species as a human pathogen has led to controversy as limited documented cases of P.agglomerans bacteremia and infections have been reported in the literature, with most cases reported among immunocompromised patients or the pediatric population. Here, we present the case of a 54-year-old female with P. agglomerans and Enterococcus faecium bacteremia along with chronic obstructive pulmonary disease.

Complete Genome Sequence of Pantoea agglomerans ASB05 Using Illumina and PacBio Sequencing

We present the complete genome sequence of Pantoea agglomerans ASB05 and three associated plasmids, generated using a combination of the Illumina and PacBio platforms. P. agglomerans ASB05 was isolated from fresh cherries purchased in Albany, CA, in 2016.

Changes in physico-chemical characteristics and viable bacterial communities during fermentation of alfalfa silages inoculated with Lactobacillus plantarum

This study investigated the effect of inoculating Lactobacillus (L.) plantarum PS-8 in fermentation of alfalfa silages. We monitored the fermentation characteristics and bacterial population dynamics during the ensiling process. PacBio single molecule real time sequencing was combined with propidium monoazide (PMA) treatment to monitor the viable microbiota dynamics. We found that inoculating L. plantarum PS-8 may improve the silage quality by accelerating acidification, reducing the amounts of clostridia, coliform bacteria, molds and yeasts, elevating the protein and organic acid contents (except butyrate), and enhancing lactic acid bacteria (LAB) while suppressing harmful microorganisms. Some significant differential abundant taxa were found between the PMA-treated and non-treated microbiota. For example, the relative abundances of L. brevis, L. plantarum, and Pediococcus pentosaceus were significantly higher in the PMA-treated group than the non-PMA-treated group, suggesting obvious differences between the viable and non-viable microbiota. It would thus be necessary to distinguish between the viable and non-viable microbial communities to further understand their physiological contribution in silage fermentation. By tracking the dynamics of viable microbiota in relation with changes in the physico-chemical parameters, our study provided novel insights into the beneficial effects of inoculating L. plantarum PS-8 in silage fermentation and the physiological function of the viable bacterial communities.

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.

Pantoea Infections in the Neonatal Intensive Care Unit

Pantoea 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 Pantoea 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 Pantoea in newborn infants. Recent advances in molecular biology have improved our understanding of the cross-kingdom pathogenesis exhibited by Pantoea. Respiratory symptoms and association with central venous lines are the most common clinical presentation of Pantoea 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 Pantoea infections in NICUs.

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

THE PURPOSE

to study the distribution of Pantoea agglomerans (P. agglomerans) statistically and the presence of bla_PER-1 type ESβL in the clinical and environmental isolates.

METHODS

During a period of 2014-2015, 895 blood specimens and 438 hospital environmental samples were collected from one children's hospital in Baghdad city. The results of statistical analysis showed there was no relationship between the infection with P. agglomerans and the sex, while there was a relationship between the infection with the P. agglomerans and the place of residence and also the age of patients.

RESULT

A total of 23 P. agglomerans were isolated during the study, out of 23 isolates, 13 (56.52%) and 10 (43.48%) were isolated from blood specimens and from hospital environment. All 23 isolates had 100% sensitivity rate to Imipenem and the highest resistant rate was (95.65%) to Ampicillin. Out of 23 P. agglomerans, 14 (60.87%) isolates were positive ESβL producing by the screening test.

CONCLUSION

The result of molecular screening of the gene bla_PER-1 showed the presence of this gene only in phenotypically ESBL producing isolates, while all negative ESβL producing isolates don't harboring bla_PER-1 gene. Out of 14 positive ESβL producing P. agglomerans isolates, 5 (35.71%) were harboring bla_PER-1 gene and 9 (64.29%) of positive ESβL producing isolates were don't harboring bla_PER-1 gene (significant difference at ≤0.05).

Prevalence of antibiotic resistant Salmonella spp. strains in shrimp farm source waters of Nagapattinam region in South India

The prevalence of antibiotic-resistant Salmonella spp. in the source waters of shrimp farms in the Nagapattinam region of South India was investigated. Water and sediment samples (188 Nos.) collected from 23 natural creeks during December 2018 to April 2019 were examined for Salmonella spp. by conventional and PCR methods. The study indicated 28.7% of water and 25.5% of sediment isolates as Salmonella spp., while PCR test gave positive for 7.44% and 5.15% of the isolates, respectively. The isolates were resistant to sulfonamide (SF), but sensitive to tetracycline (TC), chloramphenicol (CAP), and furazolidone (FZ). PCR amplification of mitochondrial 16S rRNA region identified the highly resistant Salmonella serovar as S. Montevideo, which is an emerging food-borne pathogen. The incidence of antibiotic-resistant S. Montevideo reported for the first time in the natural creeks that supply water for shrimp farms emphasizes the need for regulatory steps to control its prevalence.

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

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

Pantoea agglomerans Bacteremia: Is It Dangerous?

Introduction. Pantoea agglomerans, an anaerobic Gram-negative bacillus, is a rare cause of opportunistic infections affecting premature infants to seniors. We present a 34-year-old man who was presented for the management of diabetic ketoacidosis and developed Pantoea agglomerans bacteremia after one week of hospitalization. Case Presentation. A 34-year-old African-American male with uncontrolled diabetes mellitus type I and recurrent skin infections was admitted with diabetic ketoacidosis. He had left upper extremity abscess, preliminary wound cultures were positive for Gram-positive cocci, and an initial set of blood cultures were negative. He was started empirically on vancomycin. One week after admission, he started having chills followed by a recurrent increase in body temperature to 102 degrees Fahrenheit. The wound was healing, without active infection. Chest X-ray and CT scan of abdomen and pelvis to rule out infection were negative. Repeat blood cultures showed P. agglomerans in both the tubes. The patient was successfully treated with intravenous ceftriaxone, and he recovered fully without any complication. Discussion. Pantoea agglomerans is a bacteria associated with plants; however, it can infect humans and vertebrate animals. The outcome seems favourable with the institution of appropriate antibiotics even in immunocompromised patients.

Pantoea agglomerans as a New Etiological Agent of a Bacterial Necrotic Disease of Mango Trees

Bacterial apical necrosis of mango trees, a disease elicited by Pseudomonas syringae pv. syringae, is a primary limiting factor of mango crop production in the Mediterranean region. In this study, a collection of bacterial isolates associated with necrotic symptoms in mango trees similar to those produced by bacterial apical necrosis disease were isolated over five consecutive years in orchards from the Canary Islands. The bacterial isolates were characterized and identified as Pantoea agglomerans. Pathogenicity tests conducted on onion bulbs and mango plants confirmed that P. agglomerans strains isolated from mango trees are a new etiological agent of a bacterial necrotic disease in the Canary Islands. Pathogenicity plasmids of the pPATH family have been previously reported in P. agglomerans. The majority of putatively pathogenic (n = 23) and pathogenic (n = 4) P. agglomerans strains isolated from mango trees harbored four plasmids, one of which was close in size to the 135-kb pPATH pathogenicity plasmid. The analysis of the presence of two major genes in pPATH plasmids (repA and hrpJ) was undertaken in P. agglomerans strains isolated from mango trees. The hrpJ gene was detected in the 140-kb plasmid of pathogenic P. agglomerans strains isolated from mango trees but it showed differences in nucleotide sequences compared with other pathogenic strains. In contrast, the repA gene was not detected in any of the putatively pathogenic and pathogenic P. agglomerans strains isolated from mango trees. Finally, genetic characterization and phylogenetic analysis using the hrpJ gene and the housekeeping genes gyrB and rpoB showed that almost all P. agglomerans strains that were putatively pathogenic and pathogenic on mango trees clustered together, forming a differentiated phylogroup with respect to the other pathogenic P. agglomerans strains described from other hosts.

Molecular investigation of isolates from a multistate polymicrobial outbreak associated with contaminated total parenteral nutrition in Brazil

Background

Between November 2013 and June 2014, 56 cases of bacteremia (15 deaths) associated with the use of Total Parenteral Nutrition (TPN) and/or calcium gluconate (CG) were reported in four Brazilian states.

Methods

We analyzed 73 bacterial isolates from four states: 45 from blood, 25 from TPN and three from CG, originally identified as Acinetobacter baumannii, Rhizobium radiobacter, Pantoea sp. or Enterobacteriaceae using molecular methods.

Results

The first two bacterial species were confirmed while the third group of species could not be identified using standard identification protocols. These isolates were subsequently identified by Multi-Locus Sequence Analysis as Phytobacter diazotrophicus, a species related to strains from similar outbreaks in the United States in the 1970’s. Within each species, TPN and blood isolates proved to be clonal, whereas the R. radiobacter isolates retrieved from CG were found to be unrelated.

Conclusion

This is the first report of a three-species outbreak caused by TPN contaminated with A. baumannii, R. radiobacter and P. diazotrophicus. The concomitant presence of clonal A. baumannii and P. diazotrophicus isolates in several TPN and blood samples, as well as the case of one patient, where all three different species were isolated simultaneously, suggest that the outbreak may be ascribed to a discrete contamination of TPN. In addition, this study highlights the clinical relevance of P. diazotrophicus, which has been involved in outbreaks in the past, but was often misidentified as P. agglomerans.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3287-2) contains supplementary material, which is available to authorized users.

Infections Caused by Antimicrobial Drug-Resistant Saprophytic Gram-Negative Bacteria in the Environment

Background

Drug-resistance genes found in human bacterial pathogens are increasingly recognized in saprophytic Gram-negative bacteria (GNB) from environmental sources. The clinical implication of such environmental GNBs is unknown.

Objectives

We conducted a systematic review to determine how often such saprophytic GNBs cause human infections.

Methods

We queried PubMed for articles published in English, Spanish, and French between January 2006 and July 2014 for 20 common environmental saprophytic GNB species, using search terms “infections,” “human infections,” “hospital infection.” We analyzed 251 of 1,275 non-duplicate publications that satisfied our selection criteria. Saprophytes implicated in blood stream infection (BSI), urinary tract infection (UTI), skin and soft tissue infection (SSTI), post-surgical infection (PSI), osteomyelitis (Osteo), and pneumonia (PNA) were quantitatively assessed.

Results

Thirteen of the 20 queried GNB saprophytic species were implicated in 674 distinct infection episodes from 45 countries. The most common species included Enterobacter aerogenes, Pantoea agglomerans, and Pseudomonas putida. Of these infections, 443 (66%) had BSI, 48 (7%) had SSTI, 36 (5%) had UTI, 28 (4%) had PSI, 21 (3%) had PNA, 16 (3%) had Osteo, and 82 (12%) had other infections. Nearly all infections occurred in subjects with comorbidities. Resistant strains harbored extended-spectrum beta-lactamase (ESBL), carbapenemase, and metallo-β-lactamase genes recognized in human pathogens.

Conclusion

These observations show that saprophytic GNB organisms that harbor recognized drug-resistance genes cause a wide spectrum of infections, especially as opportunistic pathogens. Such GNB saprophytes may become increasingly more common in healthcare settings, as has already been observed with other environmental GNBs such as Acinetobacter baumannii and Pseudomonas aeruginosa.

Draft Genome Sequence of Pantoea agglomerans JM1, a Strain Isolated from Soil Polluted by Industrial Production of Beta-Lactam Antibiotics That Exhibits Valacyclovir-Like Hydrolase Activity

Strain Pantoea agglomerans JM1 was isolated from the soil of a microbiome that had been exposed to polluting pharmaceuticals. The bacterium exhibited enzymatic activities useful for the biotransformation of beta-lactams. The genome of the strain was assembled and described, and the gene encoding valacyclovir-like hydrolase was identified.

Clinical and microbiological characteristics of Pantoea agglomerans infection in children

Pantoea agglomerans is an environmental Gram-negative bacterium that rarely is responsible for the infections in humans but it is often a causative factor of a number of occupational diseases. This study evaluated the clinical and microbiological characteristics and pathogenicity of P. agglomerans in children. We retrospectively reviewed microbiological test results for all children (1 month old to 18 years old) who were admitted to our pediatric hospital between January 2000 to June 2015 and had positive clinical specimen cultures for P. agglomerans. Isolates were identified using conventional tests and the BBL Crystal E/NF ID or MALDI-TOF MS systems. Antibiotic susceptibilities were evaluated using the Kirby-Bauer disc diffusion method. We identified fifteen positive cultures from 14 patients with confirmed infections. The positive specimens included pus, urine, tracheal aspirate, blood, and central venous line samples that yielded P. agglomerans. The median patient age was 8.8 years (range: 1.5 months to 16.5 years), and all patients had underlying comorbidities. Five patients had medical devices, and two devices were removed. The most common P. agglomerans infections involved wound infections (35.7%), pneumonia (21.4%), and urinary tract infections (21.4%). Three patients had concomitant infections (Enterococcus faecium, Pseudomonas aeruginosa, and Aspergillus fumigatus). Five patients had anemia. Three patients (21.4%) died, and all three had carbapenem-resistant P. agglomerans that was detected after the first week of hospitalization; two cases involved pneumonia, which was ineffectively treated. P. agglomerans infections may be life-threatening, especially in young patients with pneumonia. Hospital-acquired P. agglomerans may have different pathogenicity and clinical features, compared to community-acquired P. agglomerans, although further studies are needed to understand the drug-resistance patterns in this bacterium.

Pantoea Species Bacteremia in a Child With Sickle Cell Disease: Looking for a Culprit

Pantoea agglomerans has been classically associated with cellulitis or synovitis secondary to penetrating trauma by vegetation. It is an infrequent cause of systemic infections. We describe the case of a 5-year-old girl with sickle cell disease with P. agglomerans bacteremia and review its potential causes.

Exiguobacterium sp. A1b/GX59 isolated from a patient with community-acquired pneumonia and bacteremia: genomic characterization and literature review

Background

Bacterial species belonging to the genus Exiguobacterium are facultative anaerobic, non-spore-forming, Gram-positive bacilli, and rarely associated with human infections. Herein, we reported the first case of community-acquired pneumonia (CAP) and bacteremia due to Exiguobacterium spp. in China.

Case presentation

An adult male with severe CAP was hospitalized. The pathogen was isolated from his bloodstream and broncho-alveolar lavage fluid. The correct identification of the micro-organism was achieved using 16S rRNA sequencing, and its antibiotic susceptibility test was performed by microdilution method. The Whole Genome Sequencing (WGS) was used to characterize its genetic features and to elucidate its potential pathogenic mechanisms. Furthermore, its genome sequence was also compared with those of 3 publicly-available Exiguobacterium strains. A PubMed search was performed for further understanding the features of Exiguobacterium infections. Phylogenetic analysis of the 16S rRNA gene sequence showed that the strain GX59 was most closely related to Exiguobacterium AT1b (99.7%). The genome of GX59 was 2,727,929 bp in size, harbouring 2855 putative protein-coding genes, 5 rRNA operons, 37 tRNA genes and 1 tmRNA. The multiple genome comparison of 4 Exiguobacterium strains demonstrated that Exiguobacterium contained 37 genes of secretion systems, including sec, tat, FEA, Type IV Pili and competence-related DNA transformation transporter (Com). Virulence factors of the micro-organism included tlyC, NprR, MCP, Dam, which might play a critical role in causing lethal infection.

Conclusions

The study highlighted the potential pathogenicity of the genus Exiguobacterium for its unique genes encoding various virulence factors and those associated with antibiotic resistance, therefore, its clinical significance should be valued.

The Potential Role of Fosfomycin in Neonatal Sepsis Caused by Multidrug-Resistant Bacteria

The broad-spectrum activity of fosfomycin, including against multidrug-resistant (MDR) strains, has led to renewed interest in its use in recent years. Neonatal sepsis remains a substantial cause of morbidity and mortality at a global level, with evidence that MDR bacteria play an increasing role. The evidence for use of fosfomycin in neonatal subjects is limited. We summarise current knowledge of the pharmacokinetics and clinical outcomes for the use of fosfomycin in neonatal sepsis and issues specific to neonatal physiology. While fosfomycin has a broad range of coverage, we evaluate the extent to which it may be effective against MDR bacteria in a neonatal setting, in light of recent evidence suggesting it to be most effective when administered in combination with other antibiotics. Given the urgency of clinical demand for treatment of MDR bacterial sepsis, we outline directions for further work, including the need for future clinical trials in this at-risk population.

Outbreak of Pantoea agglomerans Bloodstream Infections at an Oncology Clinic-Illinois, 2012-2013

OBJECTIVE To determine the source of a healthcare-associated outbreak of Pantoea agglomerans bloodstream infections. DESIGN Epidemiologic investigation of the outbreak. SETTING Oncology clinic (clinic A). METHODS Cases were defined as Pantoea isolation from blood or catheter tip cultures of clinic A patients during July 2012-May 2013. Clinic A medical charts and laboratory records were reviewed; infection prevention practices and the facility's water system were evaluated. Environmental samples were collected for culture. Clinical and environmental P. agglomerans isolates were compared using pulsed-field gel electrophoresis. RESULTS Twelve cases were identified; median (range) age was 65 (41-78) years. All patients had malignant tumors and had received infusions at clinic A. Deficiencies in parenteral medication preparation and handling were identified (eg, placing infusates near sinks with potential for splash-back contamination). Facility inspection revealed substantial dead-end water piping and inadequate chlorine residual in tap water from multiple sinks, including the pharmacy clean room sink. P. agglomerans was isolated from composite surface swabs of 7 sinks and an ice machine; the pharmacy clean room sink isolate was indistinguishable by pulsed-field gel electrophoresis from 7 of 9 available patient isolates. CONCLUSIONS Exposure of locally prepared infusates to a contaminated pharmacy sink caused the outbreak. Improvements in parenteral medication preparation, including moving chemotherapy preparation offsite, along with terminal sink cleaning and water system remediation ended the outbreak. Greater awareness of recommended medication preparation and handling practices as well as further efforts to better define the contribution of contaminated sinks and plumbing deficiencies to healthcare-associated infections are needed. Infect Control Hosp Epidemiol 2017;38:314-319.

Unusual microorganisms and antimicrobial resistances in a group of Syrian migrants: Sentinel surveillance data from an asylum seekers centre in Italy

BACKGROUND

Three years of civil war in Syria have caused death and increase of communicable diseases. The suffering population has been forced to migrate creating a fertile condition for epidemic spread of infection within the refugee camps.

METHODS

Forty-eight Syrian migrants, upon their arrival in Italy, were accommodated at the asylum seekers centre of Castelnuovo di Porto. They received a physical examination and were subjected to microbiological surveillance by blood, rectal, pharyngeal and nasal swabs collection and delivering to the Clinical Pathology and Microbiology Laboratory of the University Campus Bio-Medico of Rome.

RESULTS

All refugees resulted negative for HBV, HCV and HIV infections. In swabs a large number of unusual gram-negative bacteria species were isolated, such as Pseudomonas putida, Pseudomonas monteilii, Pseudomonas fulva, Pseudomonas moselii, Aeromonas veronii, Aeromonas caviae, Aeromonas hydrophila, Acinteobacter guilloviae, Acinteobacter lowffii; Acinetobacter johnsonii; Acinteobacter tjernbergae; Pantoea agglomerans; Pantoea calida. Among isolates, strains resistant to carbapenems, ESBL producers and methicillin resistant were found.

CONCLUSIONS

The microbiological surveillance performed represents a useful action to understand refugees health status and to trace unusual microorganisms movement even carriers of antimicrobial resistance during migrants traveling.

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.

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.

MALDI-TOF Mass Spectrometry: A Powerful Tool for Clinical Microbiology at Hôpital Principal de Dakar, Senegal (West Africa)

Our team in Europe has developed the routine clinical laboratory identification of microorganisms by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry (MS). To evaluate the utility of MALDI-TOF MS in tropical Africa in collaboration with local teams, we installed an apparatus in the Hôpital Principal de Dakar (Senegal), performed routine identification of isolates, and confirmed or completed their identification in France. In the case of discordance or a lack of identification, molecular biology was performed. Overall, 153/191 (80.1%) and 174/191 (91.1%) isolates yielded an accurate and concordant identification for the species and genus, respectively, with the 2 different MALDI-TOF MSs in Dakar and Marseille. The 10 most common bacteria, representing 94.2% of all bacteria routinely identified in the laboratory in Dakar (Escherichia coli, Klebsiella pneumoniae, Streptococcus agalactiae, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus haemolyticus, Enterobacter cloacae, Enterococcus faecalis, and Staphylococcus epidermidis) were accurately identified with the MALDI-TOF MS in Dakar. The most frequent misidentification in Dakar was at the species level for Achromobacter xylosoxidans, which was inaccurately identified as Achromobacter denitrificans, and the bacteria absent from the database, such as Exiguobacterium aurientacum or Kytococcus schroeteri, could not be identified. A few difficulties were observed with MALDI-TOF MS for Bacillus sp. or oral streptococci. 16S rRNA sequencing identified a novel bacterium, “Necropsobacter massiliensis.” The robust identification of microorganisms by MALDI-TOF MS in Dakar and Marseille demonstrates that MALDI-TOF MS can be used as a first-line tool in clinical microbiology laboratories in tropical countries.

Draft Genome Sequence of Pantoea sp. Strain MBLJ3, Isolated in a Laboratory Environmental Control Study

This report describes the draft genome sequence of a newly isolated strain, Pantoea sp. MBLJ3. The genome is 4.8 Mb in size, with a G+C content of 54.27%, and it contains 4,522 protein-coding sequences, 69 tRNA genes, and 5 rRNA genes.

Draft Genome Sequence of a Pantoea sp. Isolated from a Preterm Neonatal Blood Sepsis Patient

Herein, we report the draft genome sequence of Pantoea sp. ED-NGS-1003, cultivated from a blood sample taken from a neonatal sepsis patient at the Royal Infirmary, Edinburgh, Scotland, United Kingdom.