Leclercia adecarboxylata catheter-related bacteraemia in an immunocompromised patient
- 1 University of Kansas School of Medicine, Kansas City, Kansas, USA
- 2 Internal Medicine, The University of Kansas Health System, Kansas City, Kansas, USA
- 3 Internal Medicine, Division of Infectious Disease, The University of Kansas Health System, Kansas City, Kansas, USA
- Correspondence to Haleigh Harper; hharper2@kumc.edu
Abstract
A 34-year-old man on active chemotherapy was hospitalised with fever, chills and rigours after power-washing a pig pen on a farm. His blood cultures grew Leclercia adecarboxylata, a gram-negative rod in the Enterobacteriaceae family, which has been isolated from a variety of environments including soil, surface water, as well as in the gastrointestinal flora of farm animals. The likely source of infection was his tunnelled central venous catheter exposed to water contaminated by faeces when he was washing the pig pen. While there have been several cases reported of catheter-related L. adecarboxylata bacteraemia, to our knowledge there are very few reports of infection spread in this manner.
Background
Leclercia adecarboxylata was first described by French physician Henri Leclerc in 1962 in his study of phytotherapy under the name Escherichia adecarboxylata.1 After subsequent biochemical and DNA testing it was revealed that E. adecarboxylata could be phenotypically differentiated from all other species of Enterobacteriaceae, it was reassigned to its current name of L. adecarboxylata in 1986.2 L. adecarboxylata is a motile, aerobic, oxidase-negative, gram-negative rod of the Enterobacteriaceae family that has been found in soil, surface water and animal sources, but rarely isolated as a significant pathogen in humans. Although humans are exposed to a variety of bacteria in the environment, to cause illness, the bacteria must first incubate within the host. The mode by which a pathogen is transmitted from the environment to the host can help categorise these organisms, for example between direct or indirect contact, food or water ingestion or fecal–oral–respiratory routes.3 The exact mechanism of spread of L. adecarboxylata to humans remains unclear, although destruction of the skin barrier by wounds, trauma or catheters has been implicated4 as well as associations with water environments.5 Additionally, these pathogens may be categorised by the type of illness they cause, with L. adecarboxylata reported to cause a variety of infections including cellulitis,6 endocarditis,7 cholecystitis,8 peritonitis9 10 and bacteraemia.4 11–16
Most recently, L. adecarboxylata has been described as an emerging pathogen in immunocompromised patients in multiple case reports and is considered an opportunistic organism.16 Additionally, with the recent advancements in technology for microbial identification (specifically, Matrix-Assisted Laser Desorption/Ionization-Time Of Flight (MALDI-TOF)), L. adecarboxylata is being reported more frequently due to the ability to correctly identify and differentiate it from Escherichia coli, which it resembles phenotypically.17 Although L. adecarboxylata is a rare organism, it has the potential to cause life-threatening infections, and more research is required to elucidate its exact pathogenesis in humans. We hope to add to this growing body of literature with a report on a patient with L. adecarboxylata bacteraemia due to infection of a tunnelled central venous catheter (CVC) contaminated with pig faeces.
Case presentation
A 34-year-old man with a history of Li Fraumeni syndrome and a right upper extremity soft tissue sarcoma with metastases to lungs, liver and left femur on active chemotherapy (trabectedin) presented to an outside emergency department with fever, chills, diaphoresis and rigours over the previous 12 hours. In the emergency department, he was febrile at 101°F, tachycardic with a heart rate in the low one-hundreds, and an SpO2 of 92% on room air. Blood cultures were drawn, and he was started on empiric antibiotic therapy with a loading dose of vancomycin (1250 mg intravenous) and piperacillin/tazobactam 4.5 g intravenous every 6 hours. When his blood cultures returned 1 day later growing gram-negative rods, his vancomycin was discontinued, and after developing a rash on his upper extremities, his piperacillin/tazobactam antibiotics were switched to meropenem 2 g intravenous every 8 h. He was then transferred to our hospital for further evaluation.
Investigations
On admission to our hospital, the patient’s lab results were significant for leucopaenia with a white cell count of 2.9×109/L, an absolute neutrophil count of 1.98 K/μL and elevated procalcitonin greater than 100 ng/mL. On additional interview, the patient stated that the day prior to symptoms, he had been power-washing a pig pen, including spraying areas of the surrounding barn which were covered in pig faeces. He noted that because he was sweating, the occlusive dressing covering his tunnelled internal jugular CVC had loosened, and that his central line may have been exposed to the spraying water contaminated with pig faeces. On physical examination, mild erythema was noted at the site of the CVC, but it was without purulent discharge. Two sets of blood cultures from the outside hospital grew L. adecarboxylata, which supported pig faeces as the likely source of infection since it is found in the normal gastrointestinal flora of pigs.18 The patient was thus diagnosed with Central Line-Associated Bloodstream Infection. His CVC was explanted after additional blood cultures from two peripheral sites and the CVC were obtained; there was no evidence of tunnel tract infection noted at the time of explantation.
Treatment
After 2 days, the patient reported feeling better and remained afebrile. L. adecarboxylata susceptibility testing revealed susceptibility to ampicillin, levofloxacin and trimethoprim/sulfamethoxazole. Meropenem was changed to oral levofloxacin 750 mg daily with a planned treatment of 14 days total and the patient was discharged.
Outcome and follow-up
Several days after discharge, repeat blood cultures from the patient’s CVC (which had been subsequently removed) grew Stenotrophomonas acidaminiphila and Pseudomonas putida; there was no growth from the peripheral blood cultures or from his port-a-cath, which was otherwise not accessed and was not removed. It is suspected that these were also related to contamination of the CVC, as P. putida is commonly isolated from water and soil19 and Stenotrophomonas species have been isolated from effluents from pig farm wastewater.20 The patient was notified, and because the organisms were susceptible to fluoroquinolones, no change to his antibiotic regimen was indicated. The patient completed the total 14-day course of levofloxacin. To ensure clearance of the infection, the patient had repeat lab work 1 week after completion of his antibiotic course, which showed resolution of his leucopaenia. He also had surveillance blood cultures taken from his port which had no growth, indicating a full recovery from his bacteraemia.
Discussion
On review of the literature published in English in PubMed/Medline, we found 113 results related to infections of L. adecarboxylata. Of these, seven of the articles were about catheter-related L. adecarboxylata bacteraemia in human adults,4 10 11 13 14 21 22 as shown in table 1 and discussed in greater detail below.
Published Cases of Catheter-Related L. adecarboxylata Bacteraemia.
| Patient | Case | Catheter | Antibiotic resistance | Antibiotic treatment | Catheter management |
| 47-year-old woman | Breast cancer on chemotherapy4 | PICC | MDR | Cefepime (timing not specified) | Not specified |
| 48-year-old woman | ESRD on peritoneal dialysis10 | Peritoneal dialysis catheter | Susceptible to all tested | 3 weeks of Cefazolin | Catheter maintained |
| 50-year-old woman | ESRD on haemodialysis11 | Tunnelled CVC in internal jugular vein | MDR | 2 weeks of Meropenem and Gentamicin | Not specified |
| 81-year-old man | ESRD on haemodialysis13 | Tunnelled CVC in subclavian vein | Susceptible to all tested | 15 days of Ceftriaxone plus catheter lock therapy with Ciprofloxacin | Catheter maintained |
| 72-year-old man | Allograft failure of renal transplant on haemodialysis13 | Tunnelled CVC in subclavian vein | Susceptible to all tested | 15 days of Meropenem plus catheter lock therapy with Gentamicin | Catheter maintained |
| 55-year-old man | Trauma victim14 | Temporary CVC in subclavian vein | Susceptible to all tested | 10 days of Cefazolin | Catheter removed and replaced |
| 81-year-old man | ESRD on haemodialysis21 | Tunnelled CVC in internal jugular vein | Susceptible to all tested | 1 week of Gentamicin, 3 weeks of Amoxicillin-Clavulanic Acid, plus 4 weeks catheter lock therapy with Gentamicin | Catheter maintained |
| 58-year-old man | ESRD on haemodialysis22 | Tunnelled CVC in internal jugular vein | Susceptible to all tested | 2 weeks (antibiotics not specified) | Catheter removed |
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Table adapted from De Mauri et al [21].
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CVC, central venous catheter; ESRD, end-stage renal disease; MDR, multidrug resistant; PICC, peripherally inserted central catheter.
De Mauri et al performed a literature review of L. adecarboxylata catheter-related bacteraemia and reported on 15 different papers.21 Of these, nine of the patients reported were immunocompromised subjects. All reports responded to common antibiotics including aminoglycosides, ampicillin, piperacillin, carbapenems, trimethoprim-sulfamethoxazole, fluoroquinolones, ceftazidime, ceftriaxone and aztreonam.21 However, there has been documentation of L. adecarboxylata strains producing extended-spectrum β-lactamases, such as those reported by Shin et al,4 Mazzariol et al 15 and Alosaimi and Muhmmed Kaaki.11 The question of whether to remove a patient’s catheter has also been discussed in the literature. Both De Mauri and Fernandez-Ruiz provide cases and recommendations to preserve and maintain a patient’s catheter when possible, with a long-course (at least 2 weeks) of intravenous antibiotic infusion with antibiotic lock therapy.13 21 However, patients’ tunnelled catheters were removed in cases by Marina et al who reported on a patient receiving haemodialysis due to end-stage renal disease, and Forrester et al who reported on a trauma patient in septic shock.14 22
Because there have not been any controlled studies on the removal of CVCs for treatment of L. adecarboxylata bacteraemia, the decision must be considered on a case-by-case basis. Due to the severity of infection and immunocompromised status of our patient, it was deemed necessary to explant his tunnelled CVC.
We found only one case report published by Adapa et al which listed farm animals as a possible source of L. adecarboxylata infection.10 The patient in their case report, who lived on a cattle ranch, had been on peritoneal dialysis and was diagnosed with peritonitis due to L. adecarboxylata.
In conclusion, this report provides an additional case to the growing number of L. adecarboxylata bacteraemia cases in immunocompromised patients, but with a unique source of infection via water contaminated by pig faeces.
Learning points
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The present case involves an immunocompromised patient who developed a bacteraemia caused by infection of his tunnelled central venous catheter with Leclercia adecarboxylata after cleaning a pig pen.
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Because L. adecarboxylata is a normal part of the gastrointestinal flora of these animals, the pigs’ faeces that had been spread through sprayed water is the likely contamination source of our patient’s tunnelled central venous catheter.
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Infection is a concern for patients with central venous catheters, so patient education about reducing exposure risks as well as special care in protecting and cleaning the catheter site is required to reduce complications and mortality.
Ethics statements
Patient consent for publication
Footnotes
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Contributors HH was the primary author of the case report. HH, JL and MJ conceived the idea to write this report. All authors contributed to the care of the patient in the report. RK and MJ provided scientific, grammatical and stylistic revisions to the manuscript. All authors provided final approval of the version to be published.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Case reports provide a valuable learning resource for the scientific community and can indicate areas of interest for future research. They should not be used in isolation to guide treatment choices or public health policy.
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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.
References
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