Infected Thoracic Aortic Aneurysm Caused by Helicobacter cinaedi

Helicobacter cinaedi as a cause of primary aortic infections and the challenges of diagnosis and optimal treatment

Helicobacter cinaedi is primarily seen and diagnosed in immunocompromised patients. We present cases of primary mycotic aortitis in three immunocompetent and one immunocompromised patient caused by H cinaedi. Bacterial identification was made through perioperative samples using 16S rRNA gene sequencing, as routine culture techniques were negative owing to the slow turnaround time of H cinaedi. Successful management was achieved with a neoaortoiliac system and prolonged intravenous antibiotic therapy. All four patients had a history of having sex with men, highlighting the need to further investigate the transmission of H cinaedi in immunocompetent patients and its association with aortitis.

Helicobacter cinaedi Infections in Emergency Departments: A Descriptive Study

AIM

Helicobacter cinaedi, a Gram-negative spiral bacterium, is a rare cause of bacteremia in humans. Unfortunately, little is known about H. cinaedi infections in emergency departments (EDs). We aimed to describe the clinical features of H. cinaedi infections in the ED.

METHODS

We conducted a descriptive study at the ED of Kobe City General Hospital (KCGH) in Japan between November 2011 and December 2020. We included all ED patients with H. cinaedi infections. We retrospectively obtained the patient data from electronic medical records and described the patient characteristics, clinical course, and management of H. cinaedi infections.

RESULTS

A total of 22 patients in the ED were diagnosed with H. cinaedi infections, and all of them were detected through blood cultures. The chief complaints were vague: fever (18/22, 81.8%), chills (10/22, 45.5%), and localized pain or tenderness (8/22, 36.4%). Patients with complicated cases were also reported in the ED; three patients had vertebral osteomyelitis, two had infected aortic aneurysms, and another two had infected cysts (renal cyst and pancreatic cyst with concomitant empyema). Tetracycline (minocycline) was primarily prescribed and administered intravenously in five of 15 (33.3%) and orally in nine of 20 (45.0%) patients. Only one (4.5%) patient required surgical interventions. None of the patients died in the hospital.

CONCLUSIONS

We reported the clinical features of H. cinaedi infections in the ED. Although some patients developed complicated infections, the prognosis was not poor under appropriate treatment, and most of them were successfully treated with antibiotics, primarily tetracycline.

Decisive diagnostic clue for infectious abdominal aortic aneurysm caused by Arthrobacter russicus in a diabetic elderly woman with renal dysfunction: A case report and literature review

Infectious aortic aneurysm (IAA) can be a rare but potentially fatal sequela of infectious inflammatory disease of the aortic wall with a high incidence of rupture. The definitive diagnosis is based on vascular imaging of the aneurysm using contrast-enhanced computed tomography (CE-CT) and identification of the causative microorganism from positive blood cultures (BCs). However, IAA remains extremely difficult to diagnose and treat in patients with prior antimicrobial treatment or with renal dysfunction. Here we describe a case of an 85-year-old woman with IAA caused by Arthrobacter russicus presenting with abdominal pain and fever that was initially diagnosed as a presumptive urinary tract infection and treated with empiric antimicrobial therapy. However, persistent abdominal pain with increased serological inflammation necessitated further evaluation. Unenhanced multimodality imaging considering the renal dysfunction revealed infectious aortitis of the infrarenal abdominal aorta, together with the initial culture results, leading to the tentative diagnosis of Klebsiella pneumoniae aortitis. Thereafter, serial monitoring with unenhanced magnetic resonance angiography (MRA) using thin-slab maximum intensity projection (TS-MIP) revealed acute aortic expansion strongly suggestive of a pseudoaneurysm that was successfully treated with early surgical repair under adequate infection control. Despite negative Gram staining and tissue culture results for the excised aortic wall, a definitive diagnosis of IAA secondary to A. russicus rather than K. pneumoniae was finally made by confirming the histologic findings consistent with IAA and the identification of A. russicus 16S rRNA on the resected aortic wall. The patient also developed a vascular graft infection during the postoperative course that required long-term systemic antimicrobial therapy. This case highlights the value of unenhanced MRA in the early detection of IAA in patients with renal dysfunction and the importance of a molecular diagnosis for identifying the causative microorganism in cases of culture- or tissue-negative IAA.

Determining Infected Aortic Aneurysm Treatment Using Focused Detection of Helicobacter cinaedi

We detected Helicobacter cinaedi in 4 of 10 patients with infected aortic aneurysms diagnosed using blood or tissue culture in Aichi, Japan, during September 2017-January 2021. Infected aortic aneurysms caused by H. cinaedi had a higher detection rate and better results after treatment than previously reported, without recurrent infection.

Infected aortic aneurysm caused by Helicobacter cinaedi: case series and systematic review of the literature

Background

Helicobacter cinaedi is rarely identified as a cause of infected aneurysms; however, the number of reported cases has been increasing over several decades, especially in Japan. We report three cases of aortic aneurysm infected by H. cinaedi that were successfully treated using meropenem plus surgical stent graft replacement or intravascular stenting. Furthermore, we performed a systematic review of the literature regarding aortic aneurysm infected by H. cinaedi.

Case presentation

We present three rare cases of infected aneurysm caused by H. cinaedi in adults. Blood and tissue cultures and 16S rRNA gene sequencing were used for diagnosis. Two patients underwent urgent surgical stent graft replacement, and the other patient underwent intravascular stenting. All three cases were treated successfully with intravenous meropenem for 4 to 6 weeks.

Conclusions

These cases suggest that although aneurysms infected by H. cinaedi are rare, clinicians should be aware of H. cinaedi as a potential causative pathogen, even in immunocompetent patients. Prolonged incubation periods for blood cultures are necessary for the accurate detection of H. cinaedi.

An Unusual Case of Streptococcus pyogenes Causing Ruptured Aortic Mycotic Aneurysm

A 70-year-old male with a complex past medical history presents with confusion and slurred speech for 24 hours. His exam was unremarkable, and his CT head was negative. Both his C-reactive protein and white blood cell count were elevated. As part of the delirium workup, blood cultures were done which grew Streptococcus pyogenes with no obvious source. He was treated with appropriate antibiotics. To determine the source, a white blood cell scan was done, which showed increased localization within a left-sided upper mediastinum mass. Subsequently, chest CT scan with contrast showed an acute type B aortic dissection with mycotic aneurysm. Consequently, he was taken urgently for surgical management. He completed 6 weeks of penicillin G and was discharged to a rehabilitation center. This case illustrates both a rare entity, mycotic aneurysm secondary to Streptococcus pyogenes, and the importance of getting an Infectious Diseases consult in the setting of an unknown source of bacteremia.

Bacteremia Possibly Caused by Helicobacter cinaedi and Associated with Painful Erythema in Rheumatoid Arthritis with Malignant Lymphoma

We herein report the case of a 69-year-old woman with rheumatoid arthritis (RA) and malignant lymphoma who developed Helicobacter cinaedi bacteremia after starting rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) chemotherapy. She had a recurrent fever and painful erythema for 13 months before the diagnosis was made. This delayed diagnosis was attributable to the underlying RA, which typically presents with various cutaneous manifestations and elevated C-reactive protein levels. The erythema on the thighs, abdomen, and left forearm improved following treatment with intravenous aminobenzyl penicillin; she received antibiotics for six weeks. This case emphasizes the importance of recognizing this opportunistic infection in immunocompromised patients.