Aortic Endograft Infection by Pasteurella multocida: A Rare Case.

Infection of an aortic endograft is a rare complication following endovascular aneurysm repair. These patients have been treated with explantation of the graft to obtain source control followed by an extra-anatomic bypass to restore circulation. The present case study describes an interesting case of Pasteurella infection involving an aortic endograft managed nonoperatively by percutaneous drainage and graft preservation.

Rhizobium radiobacter Endocarditis in an Intravenous Drug User: Clinical Presentation, Diagnosis, and Treatment.

Rhizobium radiobacter, a soil-based organism, is not, usually, pathogenic unless in the immunecompromised. Endocarditis, in the immunocompromised, is a typical presentation generally as a result of catheter-based infections. We describe the presentation of R. radiobacter prosthetic valve endocarditis and the inherent challenges in its presentation and diagnosis. A patient presented with acute limb ischemia secondary to R. radiobacter-mediated endocarditis and subsequent thromboembolization of the distal superior femoral and proximal popliteal arteries in the left lower limb. He underwent an uneventful thrombolectomy that restored blood flow distal to the occlusion and restored the patency of the affected arteries. Postoperatively, the patient maintained several unexplained febrile episodes. Blood cultures remained negative for infection. A cardiac work-up demonstrated the presence of vegetative growth on the prosthetic mitral and native aortic valves. Histopathologic analysis of the extracted thrombus confirmed the presence of R. radiobacter. On further history, it was elucidated that the patient was an intravenous drug user who routinely stored drug paraphernalia in plant beds. The patient recovered uneventfully after Piptazobactam was administered. R. radiobacter, and similarly other soil-based pathogens, should be considered as a potential source of endocarditic infection and thromboembolization in patients who similarly describe a history of intravenous drug use.

Is arthroplasty immediately after an infected case a risk factor for infection?

BACKGROUND: It is common practice in many centers to avoid performing a clean case in a room in which an infected procedure has just taken place. No studies of which we are aware speak to the necessity of this precaution. QUESTIONS/PURPOSES: The purposes of this study were to identify (1) the risk of infection in a group of patients who underwent arthroplasties performed immediately after a first-stage arthroplasty for joint infection; and (2) the risk of superficial and deep infections in these patients compared with a matched group of patients who underwent arthroplasties not performed after an infected surgery. METHODS: Eighty-three patients (85 arthroplasties) who underwent arthroplasties (primary or revision) immediately after patients with known infections underwent surgery in the same operating room (OR) were analyzed for 12 months after surgery to determine the incidence of infection. They were matched for demographic factors and surgery type with a control group of 321 patients (354 arthroplasties) who underwent surgery in an OR that had not just been used for surgery involving patients with infections. We compared the risk of superficial and deep infections between the groups. RESULTS: Patients in the study group were not more likely to have infections develop than those in the control group. One patient in the study group (1.17%) and three in the control group (0.84%) had deep infections develop; the infection in the patient in the study group was caused by a different organism than that of the patient with an infection whose surgery preceded in the OR. Two superficial infections (2.35%) were detected in the study group and 17 (4.8%) were detected in the control group. CONCLUSIONS: With the numbers available, we found that a deep infection was not more likely to occur in a patient without an infection after an arthroplasty that followed surgery on a patient with an infection than in one who had surgery after a clean case. Although sample size was a potential issue in this study, the results may serve as hypothesis generating for future studies. LEVEL OF EVIDENCE: Level III, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Endovascular aortic stent graft infection with Streptococcus equi: the first documented case.

Streptococcus equi is a common equine infectious disease, but transmission to man is rare and confined to those who commonly come into close contact with horses. Similarly, prosthetic stent graft infection is a rare complication of endovascular aortic aneurysm repair. We describe the first reported case of aortic stent graft with S. equi occurring in a professional racehorse trainer. Clinical presentation, investigations, imaging and management of this case are described. In conclusion, clinicians should consider infection with rare organisms in patients with prosthetic implants who regularly come into contact with horses and other ruminants.

Degradation effect of diepoxide fixation on porcine endogenous retrovirus DNA in heart valves: molecular aspects.

PURPOSE: Xenotransplantations of porcine cells, tissues, and organs involve a risk of zoonotic viral infections in recipients, including by porcine endogenous retroviruses (PERVs), which are embedded the genome of all pigs. An appropriate preparation of porcine heart valves for transplantation can prevent retroviral infection. Therefore, the present study focuses on the effect of epoxy compounds and glutaraldehyde on the PERV presence in porcine heart valves prepared for clinical use. METHODS: Porcine aortic heart valves were fixed with ethylene glycol diglycidyl ether (EDGE) at 5 °C and 25 °C as well as with glutaraldehyde (GA) for 4 weeks. Salting out was used to isolate genomic DNA from native as well as EDGE- and GA-fixed fragments of valves every week. Quantification of PERV-A, PERV-B, and PERV-C DNA was performed by real-time quantitative polymerase chain reaction (QPCR). RESULTS: All subtypes of PERVs were detected in native porcine aortic heart valves. The reduction of the PERV-A, PERV-B, and PERV-C DNA copy numbers was observed in the heart valves which were EDGE-fixed at both temperatures, and in GA-fixed ones in the following weeks. After 7 and 14 days of EDGE cross-linking, significant differences between the investigated temperatures were found for the number of PERV-A and PERV-B copies. PERV DNA was completely degraded within the first week of EDGE fixation at 25 °C. CONCLUSIONS: EDGE fixation induces complete PERV genetic material degradation in porcine aortic heart valves. This suggests that epoxy compounds may be alternatively used in the preparation of bioprosthetic heart valves in future.

Bacterial contaminants and antibiotic prophylaxis in total hip arthroplasty.

We have investigated the contaminating bacteria in primary hip arthroplasty and their sensitivity to the prophylactic antibiotics currently in use. Impressions (627) of the gloved hands of the surgical team in 50 total hip arthroplasties were obtained on blood agar. The gloves were changed after draping, at intervals of 20 minutes thereafter, and before using cement. Changes were also undertaken whenever a visible puncture was detected. The culture plates were incubated at 37 degrees C for 48 hours. Isolates were identified and tested for sensitivity to flucloxacillin, which is a recognised indicator of sensitivity to cefuroxime. They were also tested against other agents depending upon their appearance on Gram staining. We found contamination in 57 (9%) impressions and 106 bacterial isolates. Coagulase-negative staphylococci were seen most frequently (68.9%), but we also isolated Micrococcus (12.3%), diphtheroids (9.4%), Staphylococcus aureus (6.6%) and Escherichia coli (0.9%). Of the coagulase-negative staphylococci, only 52.1% were sensitive to flucloxacillin and therefore to cefuroxime. We believe that it is now appropriate to review the relevance of prophylaxis with cefuroxime and to consider the use of other agents.

Use of light handles in the laminar flow operating theatre--is it a cause of bacterial concern?

Airborne bacteria introduced during routine joint replacement surgery are known to be an important source of joint sepsis with disastrous results. Recently, Robinson et al. [Robinson AHN, Bentley G, Drew S, Anderson J, Ridgway GL. Suction tip contamination in the ultraclean air operating theatre. Ann R Coll Surg Engl 1993; 75: 254-6] have demonstrated that the conventional surgical sucker forms a focus for airborne pathogens which results in septic loosening of hip prostheses. Similarly, the potential contamination of theatre light handles, commonly used during total hip and knee replacements, gives cause for concern. To assess if there was any evidence of contamination, we cultured bacterial swabs taken from the light handles before and after 15 such procedures, all of which were held in a conventional orthopaedic operating theatre. Fortunately, our study found no reason to stop the use of light handles in joint replacement operations.

Relation between mouth and haematogenous infection in total joint replacements.

OBJECTIVE: To investigate the source of infections associated with orthopaedic prostheses. DESIGN: Analysis of four infections of prosthetic joints with case records; minimum inhibitory and minimum bactericidal concentrations and sodium dodecylsulphate polyacrylamide gel electrophoresis of the cell wall polypeptides of the Streptococcus sanguis isolates from the mouth and infected prostheses; examination of the patients' mouths for periodontal disease and caries. SUBJECTS: Four adults (three men) aged 58-83. RESULTS: For each patient the strain of S sanguis isolated from the mouth was indistinguishable from that isolated from the prosthesis. All patients had severe periodontal disease and caries. CONCLUSIONS: The mouth was probably the source of bacterial infection in the prosthetic joints of these patients; the route of infection was possibly haematogenous. Incipient oral infection should be treated before joint replacement, and oral health should be maintained indefinitely.