Ciencia y Salud, Vol. 10, No. 2, mayo-agosto, 2026 • ISSN (impreso): 2613-8816 • ISSN (en línea): 2613-8824

PEDIATRIC INFECTIVE ENDOCARDITIS CAUSED BY ACHROMOBACTER XYLOSOXIDANS: A CASE REPORT

Endocarditis infecciosa pediátrica causada por Achromobacter xylosoxidans: reporte de caso

DOI: https://doi.org/10.22206/cisa.2026.v10i2.3227

Received: 09/07/2024 • Accepted: 03/08/2025

How to cite: Capestany, C., Ferreira, N., Vasquez, L., Matos Imbert, A., Ortiz Hernandez, I. (2026). Pediatric infective endocarditis caused by achromobacter xylosoxidans: a case report. Ciencia y Salud, 10(2), 93-99. https://doi.org/10.22206/cisa.2026.v10i2.3227

Introduction

Infective endocarditis in pediatric patients is a rare entity with a complex diagnosis, characterized by its potential complications and high morbidity and mortality. The low incidence in children makes it challenging to extrapolate results, given that the medical literature primarily relies on studies conducted in adults. This context poses challenges in recognizing the disease, given its unique presentation in the pediatric setting The most affected individuals are often those with a history of congenital heart disease, including those who have undergone corrective surgeries¹.

Achromobacter xylosoxidans, a gram-negative bacterium uncommon in cases of endocarditis, has been previously documented in older adults and people with cystic fibrosis. Its primary manifestation usually presents as pneumonia, with endocarditis being a rare occurrence. It is crucial to highlight that clinical manifestations vary widely among patients; however, fever occurs consistently in all cases. The individuals most susceptible to this bacterium are those hospitalized, with catheters or prosthetic devices. The clinical significance of Achromobacter xylosoxidans lies in its pronounced resistance to multiple antibiotics, particularly first-line antibiotics, and its tendency to coexist with other microorganisms, such as Pseudomonas aeruginosa. The limited evidence available on Achromobacter xylosoxidans restricts treatment to a more individualized one, adapted to the unique presentation of each patient. This emphasizes the pressing need for more comprehensive research to enhance the understanding and clinical approach to this pathology^{2, 3}.

Case description

We present the case of a 9-year-old male patient with a relevant medical history of type I truncus arteriosus is described. The surgical history includes three interventions: pulmonary artery cerclage in 2014, repair of the common truncus arteriosus with closure of the ventricular septal defect, and placement of a valved conduit between the right and left atria in 2016. Additionally, there are plans to place an integrated valved conduit to replace the natural right ventricular outflow tract due to an aneurysm in 2023. Postoperatively after the last surgery performed at hospital A, the patient experienced hypotension and fever (39°C). This episode was initially managed with acetaminophen and rest, leading to the resolution of the condition and subsequent discharge from the hospital. However, one week later, the child returned to Hospital A with a fever (39°C) and persistent hypotension, despite treatment with acetaminophen. At this hospital, he received a diagnosis of otitis media and was treated with amoxicillin, clavulanic acid, and ibuprofen. It is important to note that the patient was not initiated on treatment containing steroids at any point. Given the persistence of the fever, the family members decided to go to hospital B, where their primary cardiologist referred him to the hematology and infectious disease department. Various studies were conducted, and their details are provided in Tables 1, 2 and 3.

During the physical examination, the following positive findings were identified:

Given the persistence of the fever, the infectious disease department recommended the patient's admission and a transthoracic echocardiogram, which did not reveal the presence of vegetation at that time. Despite the negative results, a transesophageal echocardiogram was conducted to definitively rule out the presence of vegetation, reaffirming the absence of suggestive findings. Although both studies did not show vegetation, the possibility of infective endocarditis was not ruled out. The infectious disease department performed a blood culture and, while waiting for the results, they decided to start prophylactic antibiotic therapy with Cefepime. In addition, the decision was made to keep the patient in the isolation room of the hospital. The suspicion of infective endocarditis was based on the prolonged febrile symptoms, the laboratory results, and the recent placement of the valved conduit, performed two months previously, as clinical and associated risk factors. On the fifth day after admission, abnormal blood culture results were reported, showing the growth of Achromobacter Xylosoxidans. Achromobacter Xylosoxidans exhibited resistance to Cefepime, Amikacin, and Gentamicin but was sensitive to Imipenem, Piperacillin-Tazobactam, and Trimethoprim-Sulfamethoxazole. These findings led to the suspension of treatment with Cefepime and the establishment of a therapeutic regimen with Imipenem and Amikacin. As part of the comprehensive management, a central venous catheter was placed through surgery. It is important to highlight that constant communication was maintained with the cardiology and nutrition departments for a multidisciplinary approach to the case. The patient remained hospitalized for 22 days under the treatment, showing a favorable evolution that culminated in his discharge, outpatient management, and continuous monitoring by the infectious disease department.

In the four weeks following discharge, the patient attended a follow-up appointment with no infectious findings during the physical examination, and blood cultures indicated the absence of microorganism growth. In one of the follow-ups, the mother reported the appearance of mild pulmonary symptoms and two isolated episodes of fever during outpatient management. To date, almost a full year since discharge, medical reports and evaluations indicate that the patient has not experienced significant adverse events and has shown an adequate response and tolerance to treatment. This positive outcome is attributed to the prompt identification of the infectious agent, the selection of specific treatment based on sensitivity tests, and multidisciplinary coordination among specialists. This collaboration allowed timely adjustments and established continuous and systematic comprehensive follow-up for therapy.

Discussion

To date, the medical literature has recorded only 22 cases of infective endocarditis caused by Achromobacter xylosoxidans, with only one case previously documented in a pediatric patient. The patient presented in this report would constitute the second notable case of a child diagnosed with endocarditis attributed to A. xylosoxidans. Among the 22 previously documented cases, it is noteworthy that 36% of the patients had a prosthetic valve, and 65% presented with some form of valve anomaly. These data underline the significant association of A. xylosoxidans with pre-existing cardiac conditions, highlighting the importance of considering these factors in the diagnosis and management of infective endocarditis due to this bacterium. Although some studies suggest that antibiotic treatment can improve the patient's clinical condition, it is crucial to recognize that this does not guarantee the absence of recurrence without the incorporation of valve replacement surgery. The need for surgical interventions in specific cases is highlighted to achieve successful results. However, a small percentage of patients do manage to survive without undergoing surgery. This emphasizes the severity of A. xylosoxidans endocarditis and underscores the importance of timely surgical intervention in improving survival rates⁴.

The only pediatric case recorded to date in the literature involves a six-month-old male patient with a history of generalized arterial calcification since childhood. This patient was not suitable for surgery and developed antibiotic resistance during the progression of his disease. However, he achieved a successful recovery by receiving treatment with colistin as part of his antibiotic regimen, which led to the complete resolution of his clinical condition⁵. The case underscores the significance of alternative approaches in treating A. xylosoxidans endocarditis, particularly in situations where surgical intervention is not a viable option for the patient. It is worth noting that several previous reports document outbreaks of Achromobacter xylosoxidans in neonatal intensive care units, hemodialysis units, and burn units. These outbreaks suggest the possibility of significant transmission in specific hospital settings⁶.

In general, infective endocarditis in the pediatric population predominantly manifests in those with congenital heart disease, accounting for approximately 50-70% of cases. It is crucial to note that a younger age of the patient correlates with a less favorable prognosis for the disease. Additionally, the specific type of congenital heart disease is associated with a higher or lower risk of developing infective endocarditis. Reconstructive cardiac surgery performed in patients less than 6 months of age, especially those with congenital heart disease, is presented as a relevant predisposing factor. While the incidence of endocarditis is low in the first postoperative month, it increases with time after the intervention, except in cases involving the use of prosthetic valves or conduits. The clinical presentation of infective endocarditis in children varies depending on the age of the patient. However, the presence of a history of congenital heart disease or previous cardiac defects that have required surgical correction can significantly increase clinical suspicion. Detection of a new murmur or changes in a previous murmur may also be indicative. In the specific case of children with cardiac devices or a history of corrective surgeries, conventional transthoracic and transesophageal echocardiography may have limitations in its diagnostic performance. Therefore, considering more advanced and specific imaging methods for the evaluation of these patient populations is essential^{7, 8}.

Infections caused by Achromobacter xylosoxidans are more prevalent in patients with cystic fibrosis, especially those undergoing lung transplantation. For patients without cystic fibrosis, the medical literature is mainly based on case reports or case series. In this population, the predominant manifestation is pneumonia and bacteremia, with endocarditis and bone infections being the less common presentations. These infections pose significant public health challenges as they tend to occur more frequently in medical settings, during or after hospitalization. Individuals with medical devices (catheters, endotracheal tubes) and/or comorbidities (such as diabetes mellitus, heart conditions, kidney failure, among others) face a higher risk of contracting this bacterium. An additional challenge associated with this infection is the presence of strains that show resistance to a variety of antibiotics, including narrow-spectrum penicillins, first- and second-generation cephalosporins, ceftriaxone, cefotaxime, aztreonam, tetracycline, and aminoglycosides. While some strains may still be susceptible to ceftazidime, cefepime, piperacillin, carbapenems, sulfonamides, fluoroquinolones, doxycycline, tigecycline, and colistin, there is an increasing number of reports indicating acquired resistance to the latter. The most effective antibiotics with the best results include trimethoprim-sulfamethoxazole, ceftazidime, piperacillin, and carbapenems; however, the need for continuous monitoring is highlighted due to the increase in reports of acquired resistance to these agents⁹. In a retrospective study based on data collected over 10 years, it was observed that Meropenem showed the best in vitro activity against Achromobacter xylosoxidans. It is followed in effectiveness by Imipenem and Piperacillin/Tazobactam¹⁰. It is important to highlight that in vitro activity does not always translate directly into clinical efficacy, and the choice of antimicrobial agent should be based on the specific susceptibility of the strain involved and the clinical response of the patient. Additionally, antibiotic resistance can vary, and continuous monitoring of antimicrobial resistance is essential for guiding therapeutic decisions. This underscores the importance of conducting specific susceptibility testing to determine the optimal choice of antibiotics in individual cases of Achromobacter xylosoxidans infections.

One of the main limitations of this case is that the patient was not treated from the beginning in the hospital where he was admitted, which could have resulted in the omission of some relevant details in the evolution of his condition, considering that this had been ongoing for approximately a month. However, the potential contribution of this case to the medical literature is appreciated, given that it represents an unusual situation of infective endocarditis in a pediatric patient caused by a rare pathogen, for which extensive knowledge about the best option is not available. therapy. Resistance to multiple antibiotics and variability in the response to different agents make treatment a critical aspect in the care of these cases. Furthermore, the importance of continuous epidemiological surveillance and the adoption of preventive measures to mitigate the spread of Achromobacter xylosoxidans in hospital environments is highlighted, especially in critical units where the vulnerability of patients is high.

Conclusion

The uniqueness of this case opens the possibility of enhancing both the clinical and therapeutic understanding of Achromobacter xylosoxidans infections. By documenting the favorable response to treatment and successful multidisciplinary management, this report not only contributes to the understanding of this type of atypical infection but also establishes itself as a valuable reference point for health professionals.

Funding

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Authors’ contributions

All authors participated equally in the collection of clinical information, literature review, and drafting of the preliminary manuscript for this case report. They also reviewed and discussed the findings described and approved the final version of the manuscript for publication.

Ethical statement

This case report was conducted in accordance with the ethical principles of the Declaration of Helsinki. Approval from the ethics committee was not required due to the descriptive nature of the case. Written informed consent was obtained from the patient’s mother for the publication of the case.

Informed consent

The patient's mother provided consent for the preparation of this case report by signing an informed consent form.

Conflicto of interest

The authors declare no conflicts of interest.

Disclaimer / Editor’s note

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References

1. Vicent L, Luna R, Martínez-Sellés M. Pediatric Infective Endocarditis: A Literature Review. J Clin Med. 2022 Jun 5;11(11):3217.

2. Derber C, Elam K, Forbes BA, Bearman G. Achromobacter species endocarditis: A Case Report and Literature Review. Canadian Journal of Infectious Diseases and Medical Microbiology. 2011;22(3):17–20.

3. Isler B, Kidd TJ, Stewart AG, Harris P, Paterson DL. Achromobacter Infections and Treatment Options. Antimicrob Agents Chemother. 2020 Oct 20;64(11).

4. Kengni Tameze J, Korpak K, Compagnie M, Levie H, Cherifi S, Lali SE. Mitral endocarditis caused by Achromobacter xylosoxidans in an older patient: Case report and literature review. IDCases. 2022;27. e01421.

5. Levoy CS, Hall DJ, Berman D. Achromobacter xylosoxidans endocarditis and septic arthritis in an infant affected by generalized arterial calcification of infancy. JMM Case Rep. 2015 Dec 13;2(6).

6. Molina-Cabrillana J, Santana-Reyes C, González-García A, Bordes-Benítez A, Horcajada I. Outbreak of Achromobacter xylosoxidans pseudobacteremia in a neonatal care unit related to contaminated chlorhexidine solution. European Journal of Clinical Microbiology & Infectious Diseases. 2007 Jun 22;26(6):435.

7. Vicent L, Luna R, Martínez-Sellés M. Pediatric Infective Endocarditis: A Literature Review. J Clin Med. 2022 Jun 5;11(11):3217.

8. Baltimore RS, Gewitz M, Baddour LM, Beerman LB, Jackson MA, Lockhart PB, et al. Infective Endocarditis in Childhood: 2015 Update. Circulation. 2015 Oct 13;132(15):1487–515.

9. Isler B, Kidd TJ, Stewart AG, Harris P, Paterson DL. Achromobacter Infections and Treatment Options. Antimicrob Agents Chemother. 2020 Oct 20;64(11).

10. Pérez Barragán E, Sandino Pérez J, Corbella L, Orellana MA, Fernández-Ruiz M. Achromobacter xylosoxidans bacteremia: clinical and microbiological features in a 10-year case series. Rev Esp Quimioter. 2018 Jun;31(3):268–73.

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¹ School of Medicine, Pontificia Universidad Católica Madre y Maestra, Santiago, Dominican Republic. ORCID: https://orcid.org/0000-0003-4592-1594, email: c_capestany@hotmail.com

² School of Medicine, Pontificia Universidad Católica Madre y Maestra, Santiago, Dominican Republic. ORCID: https://orcid.org/0009-0002-5687-675X, email: natalysarita@hotmail.com

³ School of Medicine, Pontificia Universidad Católica Madre y Maestra, Santiago, Dominican Republic. ORCID: https://orcid.org/0009-0002-0649-5932, email: luisamariavr17@gmail.com

⁴ Hospital Infantil Regional Universitario Dr. Arturo Grullón, Santiago, Dominican Republic. ORCID: https://orcid.org/0000-0003-4009-6118, email: am.matos@ce.pucmm.edu.do

⁵ Hospital Infantil Regional Universitario Dr. Arturo Grullón, Santiago, Dominican Republic. ORCID: https://orcid.org/0000-0002-6906-4016, email: y.ortiz@ce.pucmm.edu.do