Recurrent Pandoraea pnomenusa Catheter-Related Bloodstream Infections in an Immunosuppressed Child: A Case Report with Review of Literature

Abstract

The list of emerging pathogens is continuously expanding. Pandoraea pnomenusa is an emerging multidrug-resistant gram-negative bacterium reported in immunocompromised patients. This case report describes an 8-year-old pediatric patient with metastatic extrarenal rhabdoid tumor who developed recurrent catheter-related bloodstream infections (CRBSI) following the placement of a peripherally inserted central catheter (PICC). One month after PICC insertion, the child developed CRBSI. Blood cultures identified a gram-negative organism, which was subsequently identified as P. pnomenusa using matrix-assisted laser desorption/ionization-time of flight mass spectrometry. Initial antibiotic therapy resulted in transient improvement, but a second episode of CRBSI occurred with persistent positive cultures. The child was treated with a prolonged course of antibiotics and required PICC removal. Imipenem, tetracyclines, and co-trimoxazole are the preferred antibiotics for treating this pathogen. The awareness of P. pnomenusa as a rare but important cause of catheter-related infection is crucial for prompt identification and initiation of appropriate and effective antimicrobial therapy.

 

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Keywords

CRBSI - Pandoraea - immunocompromised - case report

Introduction

In immunosuppressed individuals, particularly those undergoing oncology treatment, unusual and opportunistic infections are increasingly being reported. Peripherally inserted central catheters (PICCs) are commonly used in oncology patients for the administration of intravenous fluids, chemotherapy, parenteral nutrition, blood sampling, and blood product transfusions. These devices offer considerable convenience for patients, allowing them to maintain the line throughout their treatment while minimizing the discomfort of repeated blood draws and intravenous insertions. However, the risk of infection remains a major concern, particularly when the catheter is kept in place for extended periods.

Catheter-related infections can lead to serious complications, necessitating early removal of the line if the infection is not controlled. Pandoraea species typically associated with conditions like cystic fibrosis and other underlying comorbidities, are rarely reported in oncology patients but have been recognized as potential pathogens in these immunosuppressed populations. Pandoraea infections are known to cause a range of severe clinical conditions, including pneumonia, sepsis, and infective endocarditis.[1] This case report describes a rare instance of Pandoraea pnomenusa as the causative agent of recurrent catheter-related bloodstream infections (CRBSI) in an immunosuppressed child, highlighting the importance of recognizing this unusual pathogen in patients with malignancy.

 

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Case Report

An 8-year-old female pediatric patient presented with progressive abdominal distension, weight loss, and loss of appetite. Examination revealed a firm, nontender mass in the left hypochondrium, iliac, and lumbar regions. A positron emission tomography-computed tomography scan showed a 10.1 × 9 × 5.7 cm ([Fig. 1]), fluorodeoxyglucose-avid mass in the mesentery with surrounding fluid, multiple omental and peritoneal lesions, and metastasis to retroperitoneal lymph nodes and the lungs. A biopsy confirmed a malignant extrarenal rhabdoid tumor. The child was started on the European rhabdoid tumor chemotherapy protocol. A 4-Fr single-lumen PICC was inserted from the right median cubital vein in the antecubital region, with the tip positioned at the distal superior vena cava ([Fig. 2]). It was a closed-ended PICC made of medical-grade silicone tubing with a three-position valve for controlled fluid flow. The child was receiving regular dressing and flushing as per the institutional PICC maintenance protocol, which included weekly dressing and flushing with 10 mL of normal saline.

Fig. 1 Positron emission tomography-chest tomography revealing the abdominal mass.

Fig. 2 Chest radiography showing the peripherally inserted central catheter.

One month after the PICC insertion, the child was admitted with fever and a history of chills following PICC line flushing. Investigations revealed hemoglobin 11.4 g/dL, total leucocyte count 15.7 × 10⁹/L (with a differential count of 90% neutrophils, 4.9% lymphocytes, and 3.5% monocytes), and C-reactive protein 4 mg/dL (reference < 0.5). The child was started empirically on piperacillin–tazobactam and teicoplanin, suspecting a CRBSI. Paired blood cultures were obtained from the PICC and a peripheral line. Both cultures grew a gram-negative organism with a differential time to positivity. The time to positivity was 7 hours for the PICC and 16 hours for the peripheral line. MALDI-TOF MS confirmed the organism as P. pnomenusa. In light of the differential time to positivity and symptoms suggestive of a PICC-associated bloodstream infection, the child was diagnosed with P. pnomenusa CRBSI. The organism was found to be sensitive to cefoperazone–sulbactam, imipenem, meropenem, and co-trimoxazole. The organism was found to be resistant to aztreonam, amikacin, cefepime, ceftazidime, and ciprofloxacin. Antibiotics were switched to cefoperazone–sulbactam. The prophylactic dose of trimethoprim–sulfamethoxazole was increased to a therapeutic dose of 20 mg/kg/day of trimethoprim component orally for 14 days. Blood cultures became sterile after 10 days of appropriate antibiotic therapy.

The child was continued on chemotherapy. One month after the first episode, the child again developed a fever with symptoms suggestive of catheter-related infection. Empiric therapy with cefoperazone–sulbactam and teicoplanin was initiated, and appropriate cultures were sent. The child developed a second episode of CRBSI with the same organism isolated from both the peripheral and PICC. Blood cultures remained positive even after 1 week of antibiotic treatment and were only sensitive to imipenem and co-trimoxazole, with minimum inhibitory concentrations of 1 and ≤ 20 mcg/mL, respectively. The organism was resistant to other antibiotics including meropenem. Given the persistent positive blood cultures, the PICC was removed, and antibiotics were changed to imipenem and co-trimoxazole. After 14 days of treatment, blood cultures were sterile. The child recovered from CRBSI and continued chemotherapy for 5 months without any further episodes of CRBSI; however, she succumbed due to disease progression.

 

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Discussion

The Pandoraea genus belongs to the subclass of Proteobacteria.[2] It was first described by Coenye et al in 2000 and was differentiated from known cystic fibrosis pathogens like Pseudomonas and Burkholderia species.[3] Pandoraea species include P. apista, P. pnomenusa, P. norimbergenesis, P. pulmonicola, and P. sputorum. These organisms are isolated from water and soil.[3] A handful of cases have been reported in the literature, isolated from both cystic fibrosis and noncystic fibrosis patients, from sputum, lung tissue, wounds, and blood.[1] [2] [4] [5] Only one case has been reported of CRBSI in a child with leukemia.[6] Reported cases are summarized in [Table 1].

Table 1 Reported cases of Pandoraea pnomenusa

	First author, Year	Age	Gender	Underlying diagnosis	Infection	Culture	Sensitive antibiotics	Outcome
1	Falces-Romero et al, 2016	10 mo	NR	B-ALL	CRBSI	Blood	Imipenem, Minocycline	Recovered after 10 d of antibiotics
2	Ambrose et al, 2016	26 y	M	Cystic fibrosis	Pneumonia	Sputum	Imipenem, co-trimoxazole	Expired on D11 of admission
3	Gawalkar et al, 2020	42 y	M	Rheumatic heart disease with mechanical valve replacement	Infective endocarditis	Blood	Levofloxacin, minocycline, co-trimoxazole	Expired on D14 of admission
4	Stryjewski et al, 2020	30 y	M	Pulmonary sarcoidosis post-lung transplant	Sepsis/MODS	Blood	Imipenem	Expired on D17 of admission
5	Bodendoerfer et al, 2021	37 y	M	Intravenous drug users with native valve endocarditis require prosthetic valve replacement	Infective endocarditis	Blood	Piperacillin-tazobactam, cefepime, imipenem, levofloxacin, ciprofloxacin, co-trimoxazole	Recovered with 42 d of antibiotics
6	Cubides-Diaz et al, 2022	55 y	M	SARS COV-2 co-infection	Pneumonia	Respiratory secretion	Co-trimoxazole	Recovered after 14 d of antibiotics
7	Index case	8 y	F	Malignant rhabdoid tumor	CRBSI	Blood, 2 episodes	Imipenem, co-trimoxazole	First episode: Recovered after 14 d of antibiotics Second episode: Recovered after 21 d of antibiotics

Abbreviations: ALL, acute lymphoblastic leukemia; CRBSI, catheter-related bloodstream infection; MODS, multiple organ dysfunction syndrome; NR, not reported.

P. pnomenusa is an aerobic or facultatively anaerobic, nonspore-forming, nonlactose-fermenting, nonnitrate-reducing, gram-negative bacillus. It was previously categorized in the weak oxidizer group 2 and exhibits catalase activity.[7] It closely resembles Ralstonia and Burkholderia. There are documented cases of misidentification of this species as Burkholderia.[1] Molecular methods may be required for accurate species identification. In the index case, species identification was confirmed by MALDI-TOF MS. These organisms are multidrug-resistant, typically resistant to cephalosporins, penicillins, meropenem, and exhibit variable sensitivity to fluoroquinolones. They are generally sensitive to imipenem, co-trimoxazole, and tetracyclines. Resistance is often attributed to β-lactamase production and efflux mechanisms against meropenem.

Interestingly, Pandoraea species may be resistant to meropenem but sensitive to imipenem. All Pandoraea species can produce meropenem-hydrolyzing oxacillinase, while P. pnomenusa can produce OXA-62, a unique carbapenem-hydrolyzing class D β-lactamase, which confers resistance to both meropenem and imipenem, as well as other antibiotics. This highlights the importance of Pandoraea as an emerging multi-drug-resistant pathogen.[8] In the index case, the organism was sensitive to both imipenem and meropenem in the first episode but resistant to meropenem in the second episode.

The chronicity of the disease is due to biofilm formation.[9] Even documented infections can persist for years, signifying the chronic nature of the infection. In the index case, antibiotics were administered for 21 days. This pathogen is emerging as a notable cause of morbidity and mortality, especially in immunocompromised patients. It is multidrug-resistant and often coexists with conditions such as COVID-19 and cystic fibrosis.[4] [5]

The strength of this case report is that it highlights the importance of early identification and appropriate treatment of P. pnomenusa infections in immunocompromised pediatric patients. However, the scarcity of data on the pathogen emphasizes the need for more research to develop effective treatment recommendations. The limitation of this case report is the absence of long-term follow-up, which prevents evaluation of the durability and long-term outcomes of the treatment.

Understanding the unique antibiotic susceptibility patterns of these organisms and their potential to cause serious infections in immunosuppressed individuals is crucial for guiding therapy selection. Further research is needed to gather more information about this pathogen. If more cases of recurrent infections are reported, line removal may become an essential treatment option. Prolonged antibiotic therapy may be necessary to fully eradicate the organism. Imipenem, tetracyclines, and co-trimoxazole are the preferred empirical antibiotics for treating this pathogen.

 

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Conflict of Interest

None declared.

Acknowledgments

The authors would like to acknowledge the consultants, nursing staff, and other support staff involved in patient care.

Patient's Consent

The authors confirm that all necessary patient consent forms have been obtained. The patient has provided written permission for their medical images and clinical details to be included in this publication. They have been informed that their identity will be protected by withholding their name and initials.

• References

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• 6 Falces-Romero I, Gutiérrez-Arroyo A, Romero-Gómez MP. [Catheter-associated bacteremia by Pandoraea pnomenusa in an infant with acute lymphoblastic leukemia]. Med Clin (Barc) 2016; 147 (03) 132
• 7 Daneshvar MI, Hollis DG, Steigerwalt AG. et al. Assignment of CDC weak oxidizer group 2 (WO-2) to the genus Pandoraea and characterization of three new Pandoraea genomospecies. J Clin Microbiol 2001; 39 (05) 1819-1826
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Publikationsverlauf

Artikel online veröffentlicht:
03. Juli 2025