Treatment of invasive IMP-4 Enterobacter cloacae infection in transplant recipients using ceftazidime/avibactam with aztreonam: A case series and literature review.

Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) are an emerging threat in both solid organ and stem cell transplant recipients. Invasive CPE infections in transplant recipients are associated with a high mortality, often due to limited therapeutic options and antibacterial toxicities. One of the most therapeutically challenging group of CPE are the metallo-ß-lactamase (MBL)-producing Gram-negative bacteria, which are now found worldwide, and often need treatment with older, highly toxic antimicrobial regimens. Newer ß-lactamase inhibitors such as avibactam have well-established activity against certain carbapenemases such as Klebsiella pneumoniae carbapenemases (KPC), but have no activity against MBL-producing organisms. Conversely, aztreonam has activity against MBL-producing organisms but is often inactivated by other co-existing ß-lactamases. Here, we report four cases of invasive MBL-CPE infections in transplant recipients caused by IMP-4-producing Enterobacter cloacae who were successfully treated with a new, mechanism-driven antimicrobial combination of ceftazidime/avibactam with aztreonam. This novel antimicrobial combination offers a useful treatment option for high-risk patients with CPE infection, with reduced drug interactions and toxicity.

Bartonella Quintana prosthetic aortitis successfully treated with doxycycline.

Bartonella quintana is a rare cause of culture-negative endovascular infection, characterised by intracellular persistence. We describe a case of ascending aortic prosthetic graft infection due to B. quintana, in a patient with past unrecognised necrotising aortitis, which was successfully treated with doxycycline monotherapy.

High prevalence of antibiotic allergies in cladribine-treated patients with hairy cell leukemia - lessons for immunopathogenesis and prescribing.

The relationship between hematological malignancy and chemotherapy on the prevalence of antibiotic allergy label (AAL) is ill-defined. We performed a multicenter retrospective case-control study comparing AAL rates among cladribine-treated hairy cell leukemia (C-HCL) cases, non-HCL cladribine-treated controls (control-1), and fludarabine-treated controls (control-2). The prevalence of AALs in C-HCL patients was 60%, compared with control-1 (14%, p < .01) and control-2 patients (25%, p < .01). The predominant phenotype was maculopapular exanthem (92%). The drugs implicated in AAL causality in C-HCL patients included beta-lactams (81%), trimethoprim-sulfamethoxazole (58%), and allopurinol (69%). C-HCL patients demonstrate high rates of AAL, potentially due to immune dysregulation, impacting beta-lactam utilization.

Mitral and tricuspid valve repair in hypereosinophilic syndrome.

Hypereosinophilic syndrome (HES) is a rare systemic condition, defined as a persistently elevated eosinophil count associated with end organ damage and the absence of a primary cause. Cardiac involvement occurs in about 50% of patients with HES. Myocardial infiltration results in endomyocardial fibrosis, valve dysfunction and mural thrombus. The atrioventricular valves are almost always involved, resulting in regurgitation due to leaflet restriction, most commonly affecting the posterior mitral valve leaflet. Surgical management remains challenging in patients with HES with limited data on the choice of valve surgery. We describe the case of a 17-year-old woman with HES complicated by congestive cardiac failure secondary to severe mitral and tricuspid regurgitation. Because of refractory heart failure despite medical therapy, surgical mitral and tricuspid valve repair was performed, and an excellent 24-month outcome was achieved. We believe this is the first report of double valve repair in this rare condition.

Chromobacterium violaceum infection in chronic granulomatous disease: a case report and review of the literature.

Introduction.Chromobacterium violaceum is an opportunistic human pathogen, associated with significant mortality, and has been reported in patients with chronic granulomatous disease (CGD), a genetic condition causing impaired phagocytosis. Case presentation. A 28-year-old man with a history of CGD presented with fever, pharyngitis, cervical lymphadenopathy and internal jugular vein thrombosis, following travel to the rural Solomon Islands. C. violaceum was recovered from his blood. The patient recovered after treatment with meropenem and trimethoprim/sulfamethoxazole. Conclusion. To the best of our knowledge, this is the first case report of internal jugular vein thrombophlebitis (Lemierre's syndrome) caused by C. violaceum in a patient with CGD. A review of the literature demonstrated that the diagnosis of C. violaceum preceded the diagnosis of CGD in the majority of cases. This case emphasizes the importance of this organism in patients with CGD who live in or visit tropical areas.

Human cardiosphere-derived cells from patients with chronic ischaemic heart disease can be routinely expanded from atrial but not epicardial ventricular biopsies.

To investigate the effects of age and disease on endogenous cardiac progenitor cells, we obtained right atrial and left ventricular epicardial biopsies from patients (n = 22) with chronic ischaemic heart disease and measured doubling time and surface marker expression in explant- and cardiosphere-derived cells (EDCs, CDCs). EDCs could be expanded from all atrial biopsy samples, but sufficient cells for cardiosphere culture were obtained from only 8 of 22 ventricular biopsies. EDCs from both atrium and ventricle contained a higher proportion of c-kit+ cells than CDCs, which contained few such cells. There was wide variation in expression of CD90 (atrial CDCs 5-92 % CD90+; ventricular CDCs 11-89 % CD90+), with atrial CDCs cultured from diabetic patients (n = 4) containing 1.6-fold more CD90+ cells than those from non-diabetic patients (n = 18). No effect of age or other co-morbidities was detected. Thus, CDCs from atrial biopsies may vary in their therapeutic potential.