Infectious Aortitis with Multiple Mycotic Aneurysms Caused by Streptococcus agalactiae

Cryopreserved venous allograft in the treatment of a mycotic abdominal aortic aneurysm caused by group B Streptococcus

We report a case of a mycotic abdominal aortic aneurysm caused by invasive group B streptococcus. Given the anatomical suitability with healthy segments of aortoiliac vessels, in situ repair was performed. A cryopreserved femoral vein graft was chosen because of risks of graft reinfection and negated the need for bilateral femoral vein harvest. The patient remained clinically well and the graft patent with no concerns at 6 months of follow-up. A review of literature on group B Streptococcus aortitis was performed.

Emergency Department Diagnosis of Multiple Mycotic Aneurysms in an HIV-Positive Patient Using Point-of-Care Ultrasound

We report the case of a transgender woman with HIV (CD4 349), shortness of breath, and chest pain, who was found to have multiple mycotic aortic aneurysms by point-of-care ultrasound (PoCUS). This report highlights the utility of point-of-care ultrasonography in the diagnosis and management of this rare clinical entity.Multiple mycotic aortic aneurysms and purulent pericarditis are uncommon. They have high morbidity and mortality and are associated with immunocompromised states (e.g., HIV). Diagnosis of the mycotic aneurysm, and its precursor, infectious aortitis, can be challenging, and delays in care can lead to poor outcomes. Often, as described in this case report, making the diagnosis requires a high clinical suspicion, multiple imaging modalities, and laboratory studies.

A case of Infective Native (Abdominal) Aortic Aneurysm Caused by Streptococcus Agalactiae: An Updated Literature Review Based on New Nomenclature

The management of abdominal aortic aneurysms (AAA) has evolved significantly with the advent of endovascular strategies. Thus, there has been a decline in the number of open AAA repairs once an endovascular option is available. There have also been reports of successful endovascular management of infective native aortic aneurysms (INAA)¹, previously called mycotic aneurysms². The rarity of this condition makes its management a challenging one as there are no standard guidelines. The European Society of Vascular Surgery has suggested that the nomenclature be changed from mycotic aneurysms as this can be misleading to standardise reporting¹. The authors' present a case of a 67-year old male who presented during the peak of the Corona Virus pandemic with constitutional gastrointestinal symptoms. He was subsequently diagnosed with an INAA and successfully managed with open Neo-Aorto Iliac System reconstruction with a homograft³. The report highlights various strategies used in the surgical approach and their benefits in the management of INAA. Furthermore, a literature review of Streptococcus (Streptococcus agalactiae) species as a rare cause of INAA and how these cases were managed are also highlighted.

A strobe multicenter descriptive study of 55 infectious aortitis

Infectious aortitis (IA) is a rare and severe disease. The treatment classically associates open surgery with prolonged antibiotic therapy. This study aimed to describe clinical characteristics, medical and surgical supports in a large and current series of IA.We conducted a retrospective multicenter study of native aorta IA, between 2000 and 2019. Inclusion criteria were the presence of a microorganism on blood culture, aortic sample or any other validated technique and structural anomaly in imaging.We included 55 patients (85% men), with a median age of 65. Microbiology data substantially differed from previous studies with 12 Gram-negative rods IA, of which only 3 due to Salmonella spp., 24 Gram-positive cocci IA of which 12 Streptococcus spp., and 18 IA due to intracellular growth and/or fastidious microorganisms, of which 8 Coxiella burnetii, 3 Treponema pallidum, and 5 tuberculosis suspicious cases. Fifteen patients (27%) presented with thoracic IA, 31 (56%) with abdominal IA, and 9 (16%) with thoraco-abdominal IA. Eight patients had no surgery, 41 underwent open surgery, only 4 endovascular aneurysm repair, and 2 a combination of these 2 techniques. Nine patients died before 1-month follow-up. There was no difference in the mortality rate between the different types of germ or localization of IA.The variety of germs involved in IA increases. Positron emission tomography-computed tomography scan is a very useful tool for diagnosis. Surgery is still mainly done in open approach and a prospective multicenter study seems necessary to better determine the place of endovascular aneurysm repair versus open surgery.

Ascending Aortic Aneurysm Secondary to Isolated Noninfectious Ascending Aortitis

Isolated noninfectious ascending aortitis (I-NIAA) is increasingly diagnosed at histopathologic review after resection of an ascending aortic aneurysm. PubMed was searched using the term aortitis; publications addressing the issue were reviewed, and reference lists of selected articles were also reviewed. Eleven major studies investigated the causes of an ascending aortic aneurysm or dissection requiring surgical repair: the prevalence of noninfectious aortitis ranged from 2% to 12%. Among 4 studies of lesions limited to the ascending aorta, 47% to 81% of cases with noninfectious aortitis were I-NIAA, more frequent than Takayasu arteritis or giant cell arteritis. Because of its subclinical nature and the lack of "syndromal signs" as in Takayasu arteritis or giant cell arteritis, I-NIAA is difficult to diagnose before complications occur, such as an aortic aneurysm or dissection. Therefore, surgical specimens of dissected aortic tissue should always be submitted for pathologic review. Diagnostic certainty requires the combination of a standardized histopathologic and clinical investigation. This review summarizes the current knowledge on I-NIAA, followed by a suggested approach to diagnosis, management, and follow-up. An illustrative case of an uncommon presentation is also presented. More follow-up studies on I-NIAA are needed, and diagnosis and follow-up of I-NIAA may benefit from the development of diagnostic biomarkers.

Modification of the CpsA protein reveals a role in alteration of the Streptococcus agalactiae cell envelope

The bacterial cell envelope is a crucial first line of defense for a systemic pathogen, with production of capsular polysaccharides and maintenance of the peptidoglycan cell wall serving essential roles in survival in the host environment. The LytR-CpsA-Psr proteins are important for cell envelope maintenance in many Gram-positive species. In this study, we examined the role of the extracellular domain of the CpsA protein of the zoonotic pathogen group B Streptococcus in capsule production and cell wall integrity. CpsA has multiple functional domains, including a DNA-binding/transcriptional activation domain and a large extracellular domain. We demonstrated that episomal expression of extracellularly truncated CpsA causes a dominant-negative effect on capsule production when expressed in the wild-type strain. Regions of the extracellular domain essential to this phenotype were identified. The dominant-negative effect could be recapitulated by addition of purified CpsA protein or a short CpsA peptide to cultures of wild-type bacteria. Changes in cell wall morphology were also observed when the dominant-negative peptide was added to wild-type cultures. Fluorescently labeled CpsA peptide could be visualized bound at the mid-cell region near the division septae, suggesting a novel role for CpsA in cell division. Finally, expression of truncated CpsA also led to attenuation of virulence in zebrafish models of infection, to levels below that of a cpsA deletion strain, demonstrating the key role of the extracellular domain in virulence of GBS.