Description of the First Case of Catheter-Related Bloodstream Infection Due To Pantoea eucrina in a Cancer Patient
- 85 Downloads
We describe here the first case of catheter-related bloodstream infection due to Pantoea eucrina in a 23-year-old female patient with colon adenocarcinoma and congenital hypogammaglobulinemia. In May 2018, she was admitted for fever and abdominal pain. Blood cultures withdrawn from peripheral inserted central catheter and periphery revealed the presence of Pantoea eucrina, with differential time of positivity in favor of catheter-related bloodstream infection. Catheter was removed and antibiotic started, with rapid recovery. Species of genus Pantoea are mainly environmental strains and plant pathogens, rarely responsible for human infection. Patient’s comorbid conditions and gut microbiota imbalance could have been responsible for such bacteremia. Identification of Pantoea eucrina was performed using the MALDI-TOF technique. Infections due to Pantoea eucrina were probably until recently underestimated, as older methods such as Phoenix frequently lead to false identification.
KeywordsCatheter-related bloodstream infection Pantoea eucrina
Pantoea spp. are Gram-negative motile rods of the Enterobacteriaceae family. The species belonging to this genus are usually isolated from soil, fruits, and vegetables [1, 2, 3, 4], but can be ubiquitously found in host-associated microbiome such as the human gut [5, 6] and plant microbiome . Pantoea species can occasionally be involved in human infections and have been recently described as causing nosocomial outbreaks [3, 8, 9, 10]. The species Pantoea eucrina has rarely been isolated from humans. A strain isolated from a trashcan on a US university campus was sequenced and annotated for the first time by Moghadam et al. in 2016 . To our knowledge, there is no description of Pantoea eucrina bacteremia to date. We describe the first case of catheter-related bloodstream infection due to this bacterium.
To our knowledge, this is the first description of a catheter-related bloodstream infection (CLABSI) caused by P. eucrina, although a few strains have already been isolated in human samples . The P. eucrina LMG 2781T strain was isolated from a human trachea and three other strains, P. eucrina LMG 24529, 24530, and 24531 were isolated respectively from human samples: a cyst, urine, and spinal fluid . In our report, a blood-borne contamination of the PICC line by gut microbial translocation is likely. Indeed, species of the genus Pantoea are mainly environmental strains and plant pathogens and are rarely responsible for human infection [1, 2, 3, 4], but they could reflect human gut microbiota imbalance, defined as dysbiosis [5, 6, 7], which has been associated with a higher risk of microbial translocation. Indeed, the imbalance between anti-inflammatory and pro-inflammatory gut bacteria could be responsible for intestinal macrophage activation and gut barrier damage, thus increasing the risk of bacterial entry into the bloodstream, especially in immunocompromised subjects such as this patient . The presence of genes encoding for a complete flagellum assembly and a type I pilus system in the genome of P. eucrina may explain its ability to form biofilms and to colonize catheters , with a potential for causing a catheter-related bloodstream infection. Increasingly frequent identification of such previously unknown species can be accounted for by the spread of tools such as routine MALDI-TOF MS technology or 16s rDNA sequencing in bacteriology laboratories: the MALDI Biotyper-IVD 7171 database contains 408 genera and 2428 species of bacteria and is periodically incremented. Until recently, infections caused by P. eucrina were probably underestimated. Indeed, older automated methods of identification such as the Phoenix® system based on the inclusion of biochemical tests in miniaturized supports, in association with a reading and an interpretation integrated in the system, frequently lead to false identification. In our case, the Phoenix® system identified the bacterium as P. agglomerans with an identification reliability of 100%. Our report also shows the limits of the MALDI-TOF technique, which was unable to identify the species. In fact, the Brüker® database, even though it is periodically incremented, still does not contain the Pantoea eucrina species. Currently, it contains six species of Pantoea: Pantoea agglomerans, Pantoea ananatis, Pantoea calida, Pantoea dispersa, Pantoea gaviniae, and Pantoea septica. Even if the identification log score was not high enough (≤ 1.7) to lead to reliable identification, results for P. dispersa, P. spectica, P. ananatis, and P. agglomerans were provided among other Enterobacteriaceae. This observation suggests that the MALDI-TOF specters of various Pantoea species are close but, reassuringly, not enough to lead to incorrect identification, unlike methods using biochemical characteristics such as the API® gallery or phenotypical automated techniques (Phoenix®, Vitek®). Thus, 16s rDNA sequencing was used to achieve reliable identification down to the species level. Concerning AST, P. agglomerans is part of Group III Enterobacteriaceae and produces a chromosomic cephalosporinase. No AST on P. eucrina has been published yet, but considering our antibiogram results, the strain does not appear to naturally produce any resistance enzyme to β-lactams that we were able to detect using the disk diffusion test. To confirm this, whole genome sequencing of this strain would be necessary to look for antibiotic resistance genes. Moghadam et al. published a draft genome analysis of a strain of P. eucrina and showed that its genome clustered with Pantoea sp. PSNIH1 which was previously isolated from hospitalized patients and shown to carry plasmids with antibiotic resistance cassettes .
We describe here a case of CLABSI due to P. eucrina in an immunocompromised patient. This bacterium, mostly known as a phytopathogen, could be responsible for severe human infections notably because of its ability to form biofilm. The rapid spread of molecular 16S-based methods or MALDI-TOF mass spectrometry in routine bacterial identification procedures will likely lead to more accurate diagnosis  and better knowledge of the epidemiology of Pantoea spp. infection.
Strategies aiming at improving the management of intravascular catheters and proper infection control measures are needed, in order to optimize diagnosis accuracy and to reduce incidence and costs of CLABSI [15, 16]. Among strategies for reducing CLABSI, the instillation of highly concentrated antimicrobials directly in the catheter lumen, defined as “lock therapy,” has been shown to reduce the incidence of CLABSI and to prolong catheter survival, especially in hemodialysis-dependent patients. Several antimicrobials but also antiseptic agents, such as taurolodin and ethanol, showed some benefits in the prevention of device infections in cancer patients, especially in those with history of multiple CLABSI, but higher quality evidence is needed for specific recommendations in this population .
This work is dedicated to all cancer patients who fight their illness day after day. We particularly wish to thank the patient described in this work.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
Research Involving Human Participants and/or Animals
Patient gave her consent for this study.
- 5.Larsen PE, Dai Y. Metabolome of human gut microbiome is predictive of host dysbiosis. GigaScience. 2015 [cité 13 août 2018];4(1). Disponible sur: https://academic.oup.com/gigascience/article-lookup/doi/10.1186/s13742-015-0084-3
- 8.Bicudo EL, Macedo VO, Carrara MA, Castro FFS, Rage RI. Nosocomial outbreak of Pantoea agglomerans in a pediatric urgent care center. Braz J Infect Dis Off Publ Braz Soc Infect Dis. 2007;11(2):281–4.Google Scholar
- 9.Boszczowski I, Nóbrega de Almeida Júnior J, Peixoto de Miranda EJ, Pinheiro Freire M, Guimarães T, Chaves CE, et al. Nosocomial outbreak of Pantoea agglomerans bacteraemia associated with contaminated anticoagulant citrate dextrose solution: new name, old bug? J Hosp Infect. 2012;80(3):255–8.CrossRefGoogle Scholar
- 12.Bonnet JP, Bru R. Comité de l’antibiogramme de la Société Française de Microbiologie-Recommandations 2017 V2.0 Mai [Internet]. 2017. Available on: www.sfm-microbiologie.org
- 13.Brady CL, Cleenwerck I, Venter SN, Engelbeen K, De Vos P, Coutinho TA. Emended description of the genus Pantoea, description of four species from human clinical samples, Pantoea septica sp. nov., Pantoea eucrina sp. nov., Pantoea brenneri sp. nov. and Pantoea conspicua sp. nov., and transfer of Pectobacterium cypripedii (Hori 1911) Brenner et al. 1973 emend. Hauben et al. 1998 to the genus as Pantoea cypripedii comb. nov. Int J Syst Evol Microbiol. 2010;60(Pt 10):2430–40.CrossRefGoogle Scholar
- 14.Mizrahi A, Amzalag J, Couzigou C, Péan De Ponfilly G, Pilmis B, Le Monnier A. Clinical impact of rapid bacterial identification by MALDI-TOF MS combined with the bêta-LACTA™ test on early antibiotic adaptation by an antimicrobial stewardship team in bloodstream infections. Infect Dis (Lond). 2018 Sep;50(9):668–77. https://doi.org/10.1080/23744235.2018.1458147.CrossRefGoogle Scholar
- 15.Garcia RA, Spitzer ED, Beaudry J, Beck C, Diblasi R, Gilleeny-Blabac M, et al. Multidisciplinary team review of best practices for collection and handling of blood cultures to determine effective interventions for increasing the yield of true-positive bacteremias, reducing contamination, and eliminating false-positive central line-associated bloodstream infections. Am J Infect Control. 2015;43(11):1222–37.CrossRefGoogle Scholar