Multiresistent Cupriavidus pauculus infection in an immunocompromised elderly patient
- 1 Instituto Português de Oncologia de Coimbra Francisco Gentil EPE, Coimbra, Coimbra, Portugal
- 2 Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
- Correspondence to Dr Inês Gomes; ines23gomes@gmail.com
Abstract
Cupriavidus pauculus is a gram-negative bacillus aerobic bacteria widely distributed in nature that can cause, in rare cases, serious infections both in immunocompromised and immunocompetent patients. We describe a case of an elderly patient admitted in emergency room with septic shock and diagnosed with a urinary tract infection. During his hospital stay, his clinical and analytical conditions have deteriorated. Blood cultures were positive for C. pauculus only sensitive to minocycline. Despite every effort, due to multiple comorbidities and a nosocomial pneumonia, the patient ends up dying.
Background
Cupriavidus pauculus is a proteobacteria, aerobic non-fermentative motile gram-negative bacillus, rarely isolated.1 A review identified only 32 patients worldwide, with reported infection by C. pauculus, the oldest one a 77-year-old man.2 It is widely distributed in nature, with tap and bottled water being two potential routes of transmission. It can, however, lead to serious infections in immunocompromised or immunocompetent patients. It has also been described as the main cause for some hospital outbreaks, especially in intensive care units.2 According to antibiograms, this micro-organism appears to be more sensitive to broad-spectrum beta-lactams, trimethoprim/sulfamethoxazole and quinolones, with resistance to aminoglycosides, aztreonam and ampicillin, and with variable sensitivity to other antibiotics.3 Despite the low number of reported cases, several risk factors for C. pauculus infection have been identified, such as oncological disease and chemotherapy, presence of central lines, end-stage renal failure and need of dialysis, congestive heart failure and primary immunodeficiency, among others.2
Case presentation
A 90-year-old male patient with a history of chronic kidney disease, congestive heart failure, with a pacemaker, non-characterised dementia and recent hospitalisation for pneumonia and urinary tract infection, presented in emergency room with persistent high fever (39°C–40°C), disorientated and hypotensive (blood pressure 78/50 mm Hg). Blood tests showed worsening of renal function (estimated glomerular filtration rate 36 mL/min/1.73 m2), pancytopenia (leucocytes 2.6×109/L, haemoglobin 870 g/L and platelets 74×109/L) and elevation of inflammatory parameters (C reactive protein 10.6 mg/dL and procalcitonin 4.7 mg/dL). Chest X-ray showed a bilateral basal infiltrate, and the urinalysis was positive for multiresistant Klebsiella pneumonia. He started amikacin and fosfomycin, according to urinalysis sensitivity test, later associated with cefuroxime due to radiological changes compatible with de novo pneumonia. On fifth day of hospitalisation, patient’s clinical condition got worse, with a new-onset fever, lower limbs petechiae and dispersed purpuric skin lesions. After dermatological evaluation, Staphylococcus aureus infection was suspected. Two blood cultures were collected, from two different peripheral veins and empiric flucloxacillin was started, with only discrete improvement in inflammatory parameters, and very good response to topical corticoid, with fusidic acid. Three days later, it was isolated a C. pauculus on both blood cultures, only sensitive to minocycline, which was added, with clinical and analytical improvement of patient’s status. Pancytopenia worsened with transfusion needs, and a diagnosis of myelodysplastic syndrome, exacerbated by the infection and drug iatrogenesis (antibiotics and metamizole administration), was admitted after Haematology evaluation. Treatment with granulocyte growth factors was started, without any further bone marrow study, considering his advanced age and clinical condition. On the 20th day of hospitalisation, he got clinically worst, with abundant respiratory secretions and hypotension. Piperacillin/tazobactam was initiated empirically, along with norepinephrine after nonresponse to fluid challenge.
Outcome and follow-up
Despite all efforts, the response to the antibiotic and vasopressor therapy was poor and the patient’s clinical condition gradually deteriorates with death.
Discussion
C. pauculus is an uncommonly isolated and rarely pathogenic, mainly associated with several infections in immunocompromised or immunocompetent patients.4 5 To the best of our knowledge, there are only 32 published case reports of C. pauculus infections, in which most of the positive samples were blood cultures, the majority of them associated with the presence of internal devices.2 The case we report is an example of several predisposing factors, such as the immunosuppression in a patient in its ninety decade of life, with a very probable myelodysplastic syndrome and even a hypothetical contribution of a bladder catheter, or even a possible role of the pacemaker. We assumed that micro-organism presence in blood cultures was the cause of the infective state, given the temporal association with patient’s worsening condition.
The low incidence of C. pauculus infections may also be related to under-reported cases,5 assumed by misidentification by the automatised laboratory tests.
The source of the micro-organism remains indeterminate in many cases.4 In our patient, infection source was also impossible to determine. The majority of reported C. pauculus infections recovered with antibiotic treatment.2 The sensitivity of the micro-organism has been described, with a known usual sensitivity to high spectrum beta-lactams, trimethoprim/sulfamethoxazole and quinolones.3 Our patient was already under antibiotics when C. pauculus was identified, which may have contributed to the high resistance profile, only sensitive to minocycline. Despite the ability to cause serious infectious conditions, causes of death in patients with C. pauculus infection are not usually directly associated with the pathogen, but with other concomitant comorbidities.3 Although our patient initially responded satisfactorily to directed antibiotic therapy, he suffered from several infectious complications, including a nosocomial pneumonia resulting in death a few days later.
In conclusion, we present a very rare case of a C. pauculus infection, in an immunocompromised very old man, with a probable myelodysplastic syndrome, with initial encouraging response to direct antibiotic therapy, but complicated with a nosocomial pneumonia.
Learning points
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Cupriavidus pauculus is a very rare pathogen mostly found in water.
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C. pauculus infections are usually seen in immunocompromised patients, but can also be described in immunocompetent individuals.
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It may cause a wide range of infections, sometimes very serious, but it usually responds to direct antibiotic therapy.
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Patients with C. pauculus infection do not usually die from infection itself, but of associated comorbidities
Ethics statements
Footnotes
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Contributors IG: follow-up during the patient’s hospitalisation of the patient. She drew, did the bibliographic research and wrote the articleMartins. MMF: follow-up during patient’s hospitalisation of the patient and contributed to the writing of the ‘case presentation’ section. JL: follow-up during patient’s hospitalisation of the patient and reviewed the article and corrected it. AC: reviewed the article and corrected it.
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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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Competing interests None declared.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2021. No commercial re-use. See rights and permissions. Published by BMJ.
References
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