Acinetobacter spp. are emerging as opportunistic hospital pathogens that demonstrate resistance to many classes of antibiotics. In a metropolitan hospital in Cleveland, a clinical isolate of Acinetobacter baumannii that tested resistant to cefepime and ceftazidime (MIC ؍ 32 g/ml) was identified. Herein, we sought to determine the molecular basis for the extended-spectrum-cephalosporin resistance. Using analytical isoelectric focusing, a -lactamase with a pI of >9.2 was detected. PCR amplification with specific A. baumannii cephalosporinase primers yielded a 1,152-bp product which, when sequenced, identified a novel 383-amino-acid class C enzyme. Expressed in Escherichia coli DH10B, this -lactamase demonstrated greater resistance against ceftazidime and cefotaxime than cefepime (4.0 g/ml versus 0.06 g/ml). The kinetic characteristics of this -lactamase were similar to other cephalosporinases found in Acinetobacter spp. In addition, this cephalosporinase was inhibited by meropenem, imipenem, ertapenem, and sulopenem (K i < 40 M). The amino acid compositions of this novel enzyme and other class C -lactamases thus far described for A. baumannii, Acinetobacter genomic species 3, and Oligella urethralis in Europe and South Africa suggest that this cephalosporinase defines a unique family of class C enzymes. We propose a uniform designation for this family of cephalosporinases (Acinetobacter-derived cephalosporinases [ADC]) found in Acinetobacter spp. and identify this enzyme as ADC-7 -lactamase. The coalescence of Acinetobacter ampC -lactamases into a single common ancestor and the substantial phylogenetic distance separating them from other ampC genes support the logical value of developing a system of nomenclature for these Acinetobacter cephalosporinase genes.Acinetobacter spp. are commonly associated with serious nosocomial infections (10,14,23,37,40,41). Most recently, American troops wounded in Iraq (Operation Iraqi Freedom) and Afghanistan (Operation Enduring Freedom) have suffered severe infections from antibiotic-resistant Acinetobacter baumannii, making this organism an important pathogen in military health
SummarySources for allogeneic stem cells for patients with haematological disorders lacking a histocompatible sibling donor include matched unrelated donor (MUD) and umbilical cord blood (UCB). A total of 51 patients with haematological disorders, treated with myeloablation and transplantation with either unrelated human leucocyte antigen (HLA) partially matched UCB (28 patients) or HLA-matched MUD grafts (23 patients) during 1997-2003, were evaluated for life-threatening infections, haematological reconstitution, graft versus host disease, relapse and event-free survival (EFS). The median duration of neutropenia after transplantation was longer (29 d vs. 14 d) in the UCB group. The probability of donorderived neutrophil engraftment by day 42 was 0AE86 [95% confidence interval (CI) 0AE71-1AE0] in UCB recipients versus 0AE96 (95% CI 0AE87-1AE0) in MUD recipients surviving >28 d. Overall infection rates were higher in UCB recipients, particularly at the early time points (before day +50) after transplantation. Graft failure occurred in five UCB recipients and two MUD recipients and was associated with the occurrence of bacteraemia during neutropenia. The EFS at 3-year follow-up was 0AE25 in UCB and 0AE35 in MUD recipients. UCB transplantation in adults is associated with delayed neutrophil and lymphocyte recovery compared with MUD grafting, and higher rates of bacteraemia at early time points after transplantation.
Summary:The incidence of invasive fungal infection (IFIs) in hematopoietic stem cell transplantation (HSCT) recipients ranges from 10 to 25% with an overall case fatality rate of up to 70-90%. Candida and Aspergillus genera remain the two most common pathogens. Although fluconazole prophylaxis in this population has been moderately effective in reducing mortality due to invasive candidiasis, this agent does not have activity against invasive aspergillosis (IA) and other mould. Several new agents such as voriconazole and caspofungin have enhanced potency and broad-spectrum antifungal activity and show promising results against yeasts and filamentous fungi when given as therapy and as chemoprophylaxis. Further, new diagnostic tools to detect circulating fungal antigens in biological fluids and PCR-based methods to detect species or genus-specific DNA or RNA have been developed. Incorporating these techniques along with clinical criteria appear to improve the accuracy of preclinical diagnosis of IFIs. Such approaches may alter the current treatment strategy from prophylaxis to preemptive therapy, thereby potentially decreasing cost and toxicity in high-risk patients.
We present our clinical experience with two complex cases of deep fascial space infections of the neck. The first was a case of cervical necrotizing fasciitis involving the submental space. The second was an infection beginning at the soft palate and extending to the anterior mediastinum. Both infections emanated from an oral source in patients with diabetes mellitus, and both patients required multiple surgical debridements and endotracheal intubation for airway protection. Despite the declining incidence of deep space neck infections, our cases illustrate the challenging diagnostic and treatment dilemmas for the clinician managing patients with diabetes.
Patients with COVID-19 infection may present to the Emergency Department (ED) with gastrointestinal complaints and no respiratory symptoms. We are presenting 3 patients who came to the ED with abdominal pain; and the computed tomography [CT] of the abdomen showed findings suggestive of COVID-19 pneumonia. A 65-year-old male patient presented with symptoms of urinary tract infection and left renal angle tenderness. A 42-year-old male patient presented with right flank pain postextracorporeal shock wave lithotripsy. A 71-year-old male known to have type 2 diabetes mellitus and who had had whipple surgery for a neoplasm of the head of the pancreas presented with a painful epigasteric swelling. The 3 patients had positive COVID-19 polymerase chain reaction (PCR) tests and mild-to-moderate illness, and were discharged home after 2 weeks with a good recovery. The first patient had a false negative early PCR test, which turned positive on 2 repetitions of the test. A systematic review of CT abdomen, including inspection of the lung bases using the lung window in all CT abdomen, is essential to detect findings suggestive of COVID-19 pneumonia in patients requiring a CT abdomen study. As proven in the literature, CT findings of COVID-19 pneumonia have a higher sensitivity than the PCR test.
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