A mycotic aneurysm related to Salmonella Rissen infection: a case report.

BACKGROUND: Salmonella species commonly causes infection in humans and on occasion leads to serious complications, such as mycotic aneurysms. Here, we present the first case reported of a patient with a mycotic aneurysm likely secondary to Salmonella Rissen infection. CASE PRESENTATION: The patient presented with 4 weeks of lower back pain, chills and a single episode of diarrhoea 2 months prior during a 14-day trip to Hong Kong and Taiwan. Magnetic resonance imaging revealed an aneurysmal left internal iliac artery with adjacent left iliacus rim-enhancing collection. A stool culture was positive for Salmonella Rissen ST 469 EBG 66 on whole genome sequencing. The patient underwent an emergency bifurcated graft of his internal iliac aneurysm and was successfully treated with appropriate antibiotics. CONCLUSIONS: This case highlights the importance of considering the diagnosis of a mycotic aneurysm in an unusual presentation of back pain with features of infection.

Infectious aneurysm of the two primary iliac arteries: rare localization of Salmonella typhimurium infection.

Infectious aneurysm is a severe entity of the aneurysmal pathology, due essentially to a bacterial agent. The most frequently implicated organisms are salmonella and staphylococci. We report the case of an infectious aneurysm of the two primitive iliac arteries with Salmonella typhimurium in a 70-year-old man.

Characterization of roles of SpaA in Erysipelothrix rhusiopathiae adhesion to porcine endothelial cells.

Erysipelothrix rhusiopathiae is the causative agent of animal erysipelas and human erysipeloid. The major protective antigen SpaA was suggested to play important roles in E. rhusiopathiae adhesion to host cells, but there is no specific study on SpaA pathogenic roles in adhesion. In this study we characterized direct and indirect roles of SpaA in E. rhusiopathiae adhesion to porcine endothelial cells. Recombinant E. rhusiopathiae SpaA (rSpaA) successfully binded to porcine iliac arterial endothelial cells. rSpaA protein pre-incubating endothelial cells or rSpaA antiserum pre-incubating E. rhusiopathiae significantly decreased E. rhusiopathiae adhesion to endothelial cells. rSpaA successfully binded host plasminogen and fibronectin, and rSpaA antiserum significantly decreased plasminogen-recruitment activity but not fibronectin-recruitment activity of E. rhusiopathiae. In conclusion, SpaA acts as adhesin in E. rhusiopathiae adhesion to host cells, and SpaA binding activity to host plasminogen highly likely play roles in this adhesion.

Infected Iliac Pseudoaneurysm after Cardiac Catheterization Complicated by Girdlestone Pseudoarthroplasty for Recurrent Infection of Hip Prosthesis.

We report a massive infected pseudoaneurysm of the right external iliac artery in the setting of Girdlestone pseudoarthroplasty (GSA) for chronic infection. Around the time of her GSA, the patient underwent cardiac catheterization with resultant pseudoaneurysm formation. Infection was likely due to spread from her previous chronic infection. Delay in presentation occurred due to attribution of her symptoms to her GSA. The patient underwent ligation of the right external iliac artery and hip disarticulation and was discharged on antibiotics. At follow-up, she had significantly reduced pain. Although vascular complications from orthopedic procedures are well described, this case seems to have been caused by secondary infection of her iatrogenic external iliac artery pseudoaneurysm.

Antimicrobial-bonded graft patency in the setting of a polymicrobial infection in swine (Sus scrofa).

BACKGROUND: Polytetrafluoroethylene (PTFE) and Dacron are commonly used as arterial conduits in vascular trauma or infection when vein interposition graft may not be available. This study used a previously validated large animal model of polymicrobial infection to assess the patency and infectious resistance of a novel, antibiotic-impregnated graft material compared with PTFE and Dacron. METHODS: Forty-eight animals were placed into five groups for a 21-day survival period. A 6-mm PTFE, Dacron, or antimicrobial-bonded graft was used to replace the iliac artery and then inoculated with 1 × 107 colonies/mL of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. Native vessels with and without contamination served as control groups. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiologic measurements, blood cultures, laboratory data, and histopathology. RESULTS: At 21 days, 50% of PTFE, 62.5% of Dacron, and 100% of the antimicrobial-bonded grafts remained patent (P = .04). PTFE and Dacron had an equivalent number of overall infections, 87.5% and 75%, respectively (P = 1.0). There was no significant difference of infectious organisms between standard materials. The infection rate of the antimicrobial-bonded graft (25%) was significantly less than that of both PTFE and Dacron (P < .01), and all of these infections were secondary to P. aeruginosa. Clinical data did not vary significantly between groups. There were no mortalities in the protocol secondary to graft blowout or sepsis. CONCLUSIONS: The antimicrobial-bonded graft material outperformed standard PTFE and Dacron in the setting of polymicrobial infection with regard to graft patency and infection. The novel prosthetic material appears to be resistant to infection with S. aureus and to limit the growth of P. aeruginosa. Additional studies are recommended to explore the role of this antibiotic-bonded graft for use in the setting of vascular infection or trauma.

Staphylococcus aureus bacteremia with iliac artery endarteritis in a patient receiving ustekinumab.

BACKGROUND: Ustekinumab (Stelara®), a human monoclonal antibody targeting the p40-subunit of interleukin (IL)-12 and IL-23, is indicated for moderate to severe plaque psoriasis and psoriatic arthritis. In large multicenter, prospective trials assessing efficacy and safety of ustekinumab increased rates of severe infections have not been observed so far. CASE PRESENTATION: Here, we report the case of a 64-year old woman presenting with chills, pain and swelling of her right foot with dark maculae at the sole, and elevated inflammatory markers. She had received a third dose of ustekinumab due to psoriatic arthritis three days before admission. Blood cultures revealed growth of Staphylococcus aureus and imaging showed a thickening of the aortic wall ventral the bifurcation above the right internal iliac artery, resembling an acute bacterial endarteritis. Without the evidence of aneurysms and in absence of foreign bodies, the decision for conservative management was made. The patient received four weeks of antibiotic therapy with intravenous flucloxacillin, followed by an oral regime with levofloxacin and rifampicin for an additional four weeks. Inflammatory markers resolved promptly and the patient was discharged in good health. CONCLUSION: To our knowledge, this is the first report of a severe S. aureus infection in a patient receiving ustekinumab. Albeit ustekinumab is generally regarded as a safe drug, severe bacterial infections should always be included in the differential diagnosis of elevated inflammatory markers in patients receiving biologicals as these might present with nonspecific symptoms and fever might be absent. Any effort to detect deep-seated or metastatic infections should be made to prevent complications and to secure appropriate treatment. Although other risk factors for an invasive staphylococcal infection like psoriasis, recent corticosteroid injection, or prior hospitalisations were present, and therefore a directive causative link between the S. aureus bacteraemia and ustekinumab can not be drawn, we considered the reporting of this case worthwhile to alert clinicians as we believe that ongoing pharmacovigilance to detect increased risks for rare but severe infections beyond phase II and phase III trials in patients treated with biologicals is essential.

Value of 18F-FDG PET/CT in diagnosing chronic Q fever in patients with central vascular disease.

BACKGROUND: The aim of this study is to describe the value of 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosing chronic Q fever in patients with central vascular disease and the added value of 18F-FDG PET/CT in the diagnostic combination strategy as described in the Dutch consensus guideline for diagnosing chronic Q fever. METHODS: 18F-FDG PET/CT was performed in patients with an abdominal aortic aneurysm or aorto-iliac reconstruction and chronic Q fever, diagnosed by serology and positive PCR for Coxiella burnetii DNA in blood and/or tissue (PCR-positive study group). Patients with an abdominal aortic aneurysm or aorto-iliac reconstruction without clinical and serological findings indicating Q fever infection served as a control group. Patients with a serological profile of chronic Q fever and a negative PCR in blood were included in additional analyses (PCR-negative study group). RESULTS: Thirteen patients were evaluated in the PCR-positive study group and 22 patients in the control group. 18F-FDG PET/CT indicated vascular infection in 6/13 patients in the PCR-positive study group and 2/22 patients in the control group. 18F-FDG PET/CT demonstrated a sensitivity of 46% (95% CI: 23-71%), specificity of 91% (95% CI: 71-99%), positive predictive value of 75% (95% CI:41-93%) and negative predictive value of 74% (95% CI: 55-87%). In the PCR-negative study group, 18F-FDG PET/CT was positive in 10/20 patients (50%). CONCLUSION: The combination of 18F-FDG PET/CT, as an imaging tool for identifying a focus of infection, and Q fever serology is a valid diagnostic strategy for diagnosing chronic Q fever in patients with central vascular disease.

Prosthetic Graft Patency in the Setting of a Polymicrobial Infection in Swine (Sus scrofa).

BACKGROUND: In the setting of vascular injury, vein interposition graft is the preferred conduit, but may have limited availability. This study seeks to develop a large animal model assessing the graft performance of polytetrafluoroethylene (PTFE) and Dacron in the setting of a polymicrobial infection. METHODS: Thirty-seven animals were placed into 4 groups for a 21-day survival period. Six-millimeter PTFE or Dacron interposition grafts were placed in the right iliac artery with a standardized bacterial inoculation. Native vessel with and without contamination served as control groups. The inoculant was 1 × 107 of genetically labeled Pseudomonas aeruginosa and Staphylococcus aureus. The primary end points were graft patency (determined by duplex ultrasound and necropsy) and graft infection (culture with molecular analysis). Secondary end points included physiological measurements, blood cultures, laboratory data, and histopathology. RESULTS: PTFE and Dacron had similar infection rates of 85.7% and 75%, respectively. There was no significant difference in infectious organisms between graft materials. PTFE and Dacron exhibited bacterial ingrowth and transmigration to the intraluminal portion of the conduit. Forty-five percent of the Dacron group and 40% of the PTFE group remained patent at postoperative day 21 (P = 0.98). Clinical data, including white blood cell count, percent neutrophils, and lactate, did not vary significantly between groups. CONCLUSIONS: PTFE and Dacron perform similarly in terms of infection rates and graft failure as both have a propensity toward bacterial ingrowth and occlusion when compared with controls. This is a valid animal model to assess graft performance in the setting of polymicrobial infection and provides an avenue for studying novel prosthetic conduits.

Management and Prevention of Percutaneous Iliac Stent Infection: A Case Report.

A 52-year-old man was admitted in the emergency department for deteriorating mental status and suspicion of discitis. Computed tomography and positron emission tomography scan showed evidence of localized infection of the aortic bifurcation and blood cultures were positive for Staphylococcus aureus. Ten years ago, the patient underwent placement of covered metal stents on each common iliac artery due to arteritic stenosis. The infected material was removed and aortic bifurcation repaired using an autologous femoral vein graft. This case report describes the surgical procedure, patient outcome, and review on prevention of such complications.

Infective Internal Iliac Artery Aneurysm Caused by Campylobacter fetus.

A 67-year-old man with a persistent high fever was diagnosed to have an infective aneurysm in his left internal iliac artery. A blood culture detected a gram-negative spiral rod that was first identified as Campylobacter fetus subsp. venerealis based on a matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) analysis. However, the strain was finally confirmed to be Campylobacter fetus subsp. fetus based on a genetic analysis. The infection was successfully treated with emergency resection of the aneurysm, followed by 4 weeks of antibiotic therapy. Involvement of the peripheral artery is uncommon in cases of C. fetus-infective aneurysm. To figure out the epidemiology and pathogenicity of C. fetus infection, the accurate identification of the responsible organisms is essential.

Changes in mechanical, structural integrity and microbiological properties following cryopreservation of human cadaveric iliac arteries.

INTRODUCTION: The study seeks to investigate how the duration of storage of cryopreserved human cadaveric iliac arteries impacts their mechanical, structural and microbiological properties as compared to their fresh sample. MATERIALS AND METHODS: Iliac arteries were harvested from 12 human cadavers and divided into 2 groups. One group underwent mechanical stress-strain assessment immediately and another was cryopreserved for a pre-determined time-period (range, 29 to 364 days). Mechanical functionality was assessed with a customised clamping mechanism. The arteries' microbiological properties were studied pre- and post-cryopreservation. The post-thawed arteries were also assessed histologically for structural integrity. RESULTS: Of the 12 pairs, only 7 (58, 119, 150, 252, 300, 332 and 364 days) iliac arteries were included in the final analysis. The other 5 pairs (29, 90, 188, 205 and 270 days) had abundant local calcification and their stress-strain curves could not be characterised. From the curves, pre- and post-cryopreserved arteries had the most similar mechanical properties when stored for 119 days. A trend of increasing relative stiffness with increased duration of storage was noted. The post-thawed arteries demonstrated minimal fragmentation except in atherosclerotic areas. Majority of the arteries were not contaminated by bacterial or fungal infection pre- and post-cryopreservation. Also, 2 arteries (364 and 332 days) which had initial bacterial colonisation showed no bacterial growth on their post-thawed sample. CONCLUSION: Mechanically, non-atherosclerotic cryopreserved arteries can be a good substitute to their corresponding fresh arterial graft. However, the length of cryopreservation has an effect on the relative stiffness of the pre- and post-cryopreserved arteries. Histological and microbiological findings suggest that cryopreservation have little impact on an artery structural integrity and may possibly have a role in maintaining sterility and sterilising the arteries.

Endovascular treatment of an iliac artery rupture caused by invasive Salmonella spondylodiscitis.

The rate of non-typhoid Salmonella infections has increased remarkably in recent years. Endovascular system infection is one of the most serious forms of extraintestinal Salmonella infection. The abdominal aorta is frequently involved, while bone and joint involvement are rarely seen. We present a rare case of successful endovascular treatment of a left iliac artery rupture and pseudoaneurysm both occurring due to the direct invasion of lumbar spondylodiscitis caused by Salmonella typhimurium.

Endovascular repair of a Streptococcus pneumonia-induced aortitis complicated by an iliacocaval fistula.

PURPOSE: To describe the successful endovascular treatment and follow-up of a patient with a Streptococcus pneumonia-induced right iliacocaval fistula. CASE REPORT: A 82-year-old man was diagnosed with a right iliacocaval fistula, as a result of Streptococcus pneumoniae infection of the distal aorta and proximal right common iliac artery. After antibiotic treatment, he was initially unsuccessfully treated with balloon expandable covered stents. Then, the fistula was excluded by an aortamonoiliac endograft to the left common iliac artery, and occluders in the distal and proximal right common iliac artery followed by a femoral-femoral crossover bypass. Postoperatively patient was treated with prolonged antibiotics. After a follow-up of 20 months, there are no signs of active infection, endoleak, or fistula, both clinically and on 2-deoxy-2-[F18]fluoro-D-glucose positron emission tomography/computed tomography. CONCLUSION: In selected patients, complicated infectious disease of the aorto-iliac tract may be treated successfully with an endograft and prolonged antibiotics.

Assessment of the antimicrobial activity of acellular vascular grafts.

Several studies have reported biological vascular grafts to be more resistant to microbial infection than synthetic counterparts in vivo. Indeed, small intestinal submucosa (SIS) materials have previously been reported to be antimicrobial. The aim of this study was to assess the antimicrobial activity and the ability to resist biofilm formation of a novel acellular vascular graft and compare it to commercially available alternatives using a range of organisms: MRSA, MSSA, Staphylococcus epidermidis, Enterococcus faecalis, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Candida albicans. This was achieved using a modified disk diffusion assay and extraction of the materials into solution followed by minimum inhibitory concentration assays. To assess resistance to biofilm formation a novel biofilm assay was developed which compared the total colony forming units (CFU) recovered from each material and identification of the percentage of CFU which were loosely attached, residing within the biofilm or attached to the biomaterial. The results indicated a lack of antimicrobial activity for all materials tested, including SIS. The biological materials were more resistant to the formation of a biofilm compared to Dacron.

[Complications of infected aneurysm due to Salmonella enteritidis: a case report]. / Complications d'un anévrisme infecté à Salmonella enteritidis: à propos d'un cas.

Salmonelloses are becoming more frequented. To date, very few cases of aneurisms or vascular grafts infections have been described. We report the rare case of an extradigestive manifestation, due to Salmonella enteritidis affecting a patient with Behçet disease. The biological diagnosis is based on microorganism isolation from the site of infection but also from blood cultures. The initial treatment combined antibiotherapy and surgical procedure and replacement of the arteriovenous graft.

Anastomotic pseudoaneurysm complicating renal transplantation: treatment options.

INTRODUCTION: Anastomotic pseudoaneurysm following renal transplantation is uncommon. Indications for repair, treatment options and outcomes remain controversial. REPORT: We present 6 renal transplant recipients with large anastomotic pseudoaneurysms. Five of the patients underwent open repair while one had a stent-grafting and delayed transplant nephrectomy for a ruptured pseudoaneurysm. A transplant nephrectomy was needed in all cases but one. Arterial reconstruction enabled limb salvage in all cases. One patient died of sepsis postoperatively. No patient presented late infection, failure of vascular reconstruction, nor pseudoaneurysm recurrence. CONCLUSIONS: Surgical excision of anastomotic pseudoaneurysms results in high rates of allograft loss. Less invasive techniques have a place in selected cases.

Significance of infection markers and microbiological findings during tissue processing of cryopreserved arterial homografts for the early postoperative course.

BACKGROUND: To evaluate homograft implantation for the urgent treatment of vascular infections on the basis of the course of infection using microbiological findings in perioperatively obtained specimens and during homograft processing. PATIENTS AND METHODS: 85 patients were treated with cryopreserved homografts from 2004-2007. The microbiological findings of the decontamination process of homografts in the tissue bank were evaluated. The perioperative infection profile (microorganisms, CRP, leukocytes, body temperature) of the patients was analysed. RESULTS: Complete microbiological and clinical follow-up for the postoperative course was available for 35 patients, who were treated with homografts from the same tissue bank and finally included into this study. 55 cryopreserved homografts were implanted. 35/55 (64%) homografts were positive for microorganisms before decontamination. 3/35 (9%) homografts remained positive after the decontamination. 33 patients were operated for prosthetic graft infection and 2 for an infiltration of a large vessel from neighbouring malignant disease. The most common infection agent was Staphylococcus aureus. Thirty-day mortality was 20% (7/35). Only in 4/35 (11%) patients were the microorganisms of the intraoperative swabs also detected during the postoperative course. The microorganisms were ORSA, Enterococcus faecium, Enterobacter aerogenes and Burkholderia cepacia. The patient with ORSA infection died on POD 11 from multiple organ failure and all other patients recovered. None of the postoperative swabs showed the homograft predecontamination microorganisms. Interestingly, a significant association (P = 0.003) between C-reactive protein increase two weeks after surgery and donor-recipient ABO mismatch was found. CONCLUSIONS: The implantation of homografts following the established decontamination is an alternative urgent therapeutic option in vascular infections with encouraging outcomes. The absence of the predecontamination focus in the postoperative specimens of patients, suggests that the postoperative course and outcomes show no strong relation to potential homograft contamination prior to the decontamination process.