Case report: Anaerobiospirillum prosthetic joint infection in a heart transplant recipient.

BACKGROUND: We report a case of prosthetic hip joint infection in a heart transplant recipient due to Anaerobiospirillum succiniciproducens, a genus of spiral-shaped curved anaerobic gram-negative rod which colonizes the gastrointestinal tract of cats and dogs. Invasive infections in humans are rare and typically occur in immunocompromised hosts. CASE PRESENTATION: A 65-year-old male dog breeder with a history of rheumatoid arthritis, bilateral hip arthroplasties, and non-ischemic cardiomyopathy with a heart transplant 10 years ago presented with a three month history of progressive left hip pain and frank purulence on hip aspiration. He underwent irrigation and debridement of the left hip and one-stage revision with hardware exchange. Although gram stain and culture from synovial fluid and intraoperative cultures were initially negative, anaerobic cultures from tissue specimens later grew a spiral-shaped gram-negative rod, identified as Anaerobiospirillum spp. by 16S rRNA gene sequencing. The patient was treated with ceftriaxone 2 g daily for 6 weeks with a good response to treatment. A similar organism was unable to be isolated from culture of 2 of the patient's dogs, however, they were thought to be the most likely source of his infection. CONCLUSION: Anaerobiospirillum spp. should be considered in immunocompromised patients with exposure to dogs or cats who present with bacteremia, gastrointestinal infection, pyomyositis, or prosthetic joint infections, especially in cases of culture-negative or with anaerobic culture growth.

First reported detection of biofilm formation by Campylobacter fetus during investigation of a case of prosthetic valve endocarditis.

AIMS: Campylobacter fetus subsp fetus (CFF) can cause intestinal illness, particularly in immunocompromised humans, with the potential to cause severe systemic infections. CFF is a zoonotic pathogen with a broad host range among farm animals and humans, inducing abortion in sheep and cows. The current paper describes a strain of CFF isolated from a patient with prosthetic valve endocarditis in Mercy University Hospital, Cork, Ireland, during 2017. Only five cases of C. fetus as a cause of prosthetic valve endocarditis have been reported in the literature, with no reports of biofilm formation within the species. METHODS: The aetiological strain was speciated and subspeciated by the VITEK 2 NH card and matrix-assisted laser desorption ionisation time-of-flight mass spectrometry. CFF biofilm formation was analysed using a crystal violet staining method. C. jejuni National Collection of Type Cultures (NCTC) 11168 was used as a positive control organism. Strains were incubated statically in Mueller-Hinton broth and Mueller-Hinton broth supplemented with 0.025% sodium deoxycholate for 3 and 7 days at 37°C, microaerobically. RESULTS: The CFF strain formed stronger attached biofilms on polystyrene plates on day 3 (72 hours) than the C. jejuni NCTC 11168 control strain, but were weaker than the control strain on day 7 in Mueller-Hinton broth. Monoculture of this C. fetus isolate was found to exist in three defined forms of biofilms (attached, air-liquid interface and floccules). CONCLUSIONS: This clinically significant C. fetus isolate showed considerable biofilm-forming capability, which we suggest conferred a survivalist advantage, contributing to the genesis of infective prosthetic valve endocarditis.

An unusual case of Erysipelothrix rhusiopathiae prosthetic joint infection from the Canadian Arctic: whole genome sequencing unable to identify a zoonotic source.

BACKGROUND: Erysipelothrix rhusiopathiae is a zoonotic pathogen that causes erysipeloid and is most frequently associated with exposure to domestic swine. Infection of native and prosthetic joints is a rarely reported manifestation. CASE PRESENTATION: We describe a case of E. rhusiopathiae prosthetic joint infection in a woman with a history of exposure to wild animals in the Canadian Arctic. Patient management involved a 1-stage surgical revision exchange with an antibiotic impregnated cement spacer and 6 weeks of intravenous penicillin G followed by 6 weeks of oral amoxicillin. Ten previously reported cases of E. rhusiopathiae joint infection are reviewed. Recent increases in mortality due to infection with this organism among host animal populations in the Canadian Arctic have generated concern regarding a potential increase in human infections. However, whole genome sequencing (WGS) of the organism was unable to identify a zoonotic origin for this case. CONCLUSIONS: Consideration should be given to E. rhusiopathiae as a cause of joint infections if the appropriate epidemiologic and host risk factors exist. Expanded use of WGS in other potential animal hosts and environmental sources may provide important epidemiologic information in determining the source of human infections.

Surgical Case Order Has an Effect on the Risk of Subsequent Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) after total joint arthroplasty (TJA) is a serious complication with multiple etiologies. Prior spine literature has shown that later cases in the day were more likely to develop surgical site infection. However, the effect of case order on PJI after TJA is unknown. This study aims to determine the influence of case order, prior infected case, and terminal cleaning on the risk for a subsequent PJI. METHODS: A retrospective, single-institution study was conducted on 31,499 TJAs performed from 2000 to 2014. Case order was determined by case start times per date within the same operating room. PJI was defined by the Musculoskeletal Infection Society criteria. Logistic regression was used to determine risk factors for a subsequent PJI. RESULTS: Noninfected cases followed an infected case in 92 of 31,499 cases (0.29%) and were more likely to develop PJI (adjusted odds ratio [OR], 2.43; P = .029). However, terminal cleaning after infected cases did not affect the risk for PJI in cases the following morning (OR, 1.42; P = .066). Case order had an OR of 0.98 (P = .655), implying that later cases did not have a higher likelihood of infection. CONCLUSION: Although surgical case order is not an independent risk factor for subsequent PJI, TJA cases following an infected case in the same room on the same day have a higher infection risk. Despite improved sterile technique and clean air operating rooms, the risk of contaminating a TJA with pathogens from a prior infected case appears to be high. Terminal cleaning appears to be effective in reducing the bioburden in the operating room.

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.

The use of whole-genome sequencing for molecular epidemiology and antimicrobial surveillance: identifying the role of IncX3 plasmids and the spread of blaNDM-4-like genes in the Enterobacteriaceae.

AIMS: To characterise the resistome of a multi-drug resistant Klebsiella pneumoniae (Kp0003) isolated from an Australian traveller who was repatriated to a Sydney Metropolitan Hospital from Myanmar with possible prosthetic aortic valve infective endocarditis. METHODS: Kp0003 was recovered from a blood culture of the patient and whole genome sequencing was performed. Read mapping and de novo assembly of reads facilitated in silico multi-locus sequence and plasmid replicon typing as well as the characterisation of antibiotic resistance genes and their genetic context. Conjugation experiments were also performed to assess the plasmid (and resistance gene) transferability and the effect on the antibiotic resistance phenotype. RESULTS: Importantly, and of particular concern, the carbapenem-hydrolysing ß-lactamase gene blaNDM-4 was identified on a conjugative IncX3 plasmid (pJEG027). In this respect, the blaNDM-4 genetic context is similar (at least to some extent) to what has previously been identified for blaNDM-1 and blaNDM-4-like variants. CONCLUSIONS: This study highlights the potential role that IncX3 plasmids have played in the emergence and dissemination of blaNDM-4-like variants worldwide and emphasises the importance of resistance gene surveillance.

Empathy dolls: are they a source of cross-contamination between patients?

Following a cluster of two patients with identical strains of Clostridium perfringens prosthetic joint infections on an ortho-geriatric ward in a teaching hospital in England, investigations were conducted into infection control practices. It emerged that empathy dolls were being used to help alleviate agitation in dementia patients; this had been introduced without consultation with the infection prevention and control team. Environmental testing of the doll pre and post laundry at different temperatures helped to establish the types and numbers of organisms present. This testing enabled our unit to provide guidance on the optimum strategy for decontamination and safe use of these dolls.

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.

Aortic graft infection and mycotic aneurysm with Streptococcus equi zooepidemicus: two cases with favorable outcome of antibiotic treatment.

Infections with Streptococcus equi zooepidemicus are rare and are associated with contact with animals or animal products. There are very few reports about infected vascular grafts or aneurysms with this etiology. We present two patients. The first is a 77-year-old man with an infected bifurcated graft four years after an open operation for an abdominal aortic aneurysm (AAA). The second is a 72-year-old man with a symptomatic mycotic AAA, treated with endovascular aneurysm repair. Both received prolonged treatment with bactericidal antibiotics and responded well. Follow-up time at present is 5.5 years for the first, and 4.5 years for the second, patient.

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.

[Non-tuberculous mycobacterial infections related to esthetic care in France, 2001-2010]. / Infections à mycobactéries atypiques liées à des soins esthétiques en France, 2001-2010.

Non-tuberculous mycobacteria (NTM) infections usually occur in immunocompromised patients but also in immunocompetent patients following invasive procedures, especially for esthetic purposes. Since 2001, 20 episodes (57 cases) of NTM infections, seven of which (43 cases) were related to esthetic care, have been reported to the regional infection control coordinating centers (RICCC), the local health authorities (LHA), and the national institute for public health surveillance. Four notifications (40 cases) were related to non-surgical procedures performed by general practitioners in private settings: mesotherapy, carboxytherapy, and sclerosis of microvaricosities. The three other notifications (three cases) concerned surgical procedures-lifting and mammary prosthesis. Practice evaluations performed by the RICCC and LHA for five notifications showed deficiency of standard hygiene precautions and tap water misuse for injection equipment cleaning, or skin disinfection. Microbiological investigations (national reference center for mycobacteria) demonstrated the similarity of patient and environmental strains: in one episode (16 cases after mesotherapy), M. chelonae isolated from tap water was similar to those isolated from 11 cases. Healthcare-associated NTM infections are rare but have a potentially severe outcome. These cases stress the need of healthcare-associated infection notifications in outpatient settings.

[Chronic brucellosis: a rare cause of septic loosening of arthroplasties with high risk of laboratory-acquired infections]. / Brucellose: eine seltene Ursache für Endoprothesenlockerungen, einhergehend mit einem hohen Infektionsrisiko für Labormitarbeiter.

Brucella spp. are a main contributor to morbidity in endemic countries, especially in the Near and Middle East and the Mediterranean. However, in most western industrialised countries, cases are rare. Here, we report the case of a previously unrecognised chronic brucellosis with subsequent laboratory-acquired infection. A 64-year-old female presented to the orthopaedic department with loosening of her knee prosthesis after total knee arthroplasty five years earlier. Bacterial cultures were obtained in a preoperative puncture of the affected joint. About two weeks after replacement of the prosthesis bacterial growth was detected by chance in the preoperative culture and Brucella melitensis was diagnosed, whereas the intraoperative swab was negative. Serology revealed a chronic brucellosis while blood cultures were negative. Antibiotic treatment with rifampin and doxycycline was initiated. Two months later, a 32-year-old male physician who was involved in identifying the bacterial pathogen began to suffer from night sweats, weight loss and elevated temperatures. Another 4 weeks later, he developed hip pain and synovialitis. At that time, blood cultures and urine specimens were positive for Brucella melitensis. The serological results were consistent with acute brucellosis. In many European and North American countries, especially Germany, Brucella spp. are rarely isolated from clinical microbiological specimens and present a considerable risk for laboratory-acquired infections.

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.