Multidrug-resistant Acinetobacter baumannii infections in lung transplant patients in the cardiothoracic intensive care unit

BACKGROUND

Multidrug-resistant (MDR) gram-negative bacteria are a growing threat to solid organ transplantation (SOT) patients in the intensive care unit (ICU). We aimed to examine the mortality rates of gram-negative MDR bacterial infection in SOT patients compared with patient population undergoing other cardiothoracic surgeries and hospitalized under similar ICU conditions.

METHODS

A retrospective study from a single medical center, including patients with MDR Acinetobacter baumannii and carbapenem-resistant Klebsiella pneumoniae infection, hospitalized in the cardiothoracic ICU. Data were collected from computerized databases, and data were verified using the hospitalization files. Microbiological data were provided by the microbiology laboratory.

RESULTS

During the study period, 205 SOT patients and 5031 other patients were hospitalized in the cardiothoracic ICU. Active infection with gram-negative MDR bacteria was identified in 147 patients, of which 37 underwent SOT (18% of total transplant recipients) and 110 underwent another cardiothoracic surgery (2% of total patients who are not transplant recipients). Mortality rates were high among both groups of patients, with no significant difference between them.

CONCLUSIONS

Infection with resistant bacteria is more prevalent among patients following SOT compared with patients following other cardiothoracic surgeries. Mortality is high in all patients regardless of the immunocompromised condition.

Association of vancomycin serum concentrations with efficacy in patients with MRSA infections: a systematic review and meta-analysis

Recent Infectious Diseases Society of America guidelines for the treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections recommend maintaining vancomycin trough concentrations of 15-20 mg/L for serious infections. We conducted a systematic review and meta-analysis of all studies assessing the impact of low (<15 mg/L) vs. high (≥ 15 mg/L) vancomycin trough level on the efficacy of MRSA infections treatment. Four prospective and 12 retrospective studies were included (2003 participants). No significant difference was demonstrated between low and high vancomycin trough level for the outcome of all-cause mortality (odds ratio (OR) 1.07, 95% confidence interval (CI) 0.78-1.46, I(2) = 28%). In studies evaluating mainly MRSA pneumonia, there was significantly higher mortality with low vancomycin level (OR 1.78, 95% CI 1.11-2.84). No significant difference was demonstrated in treatment failure rates (OR 1.25, 95% CI 0.88-1.78, I(2) = 51%). However, excluding one outlier study from the analysis, treatment failure became significantly higher in patients with low vancomycin trough level (OR 1.46, 95% CI 1.12-1.91, I(2) = 16%). Microbiologic failure rates were significantly higher in patients with low vancomycin levels (OR 1.56, 95% CI 1.08-2.26, I(2) = 0%). Nephrotoxicity was significantly higher with vancomycin levels of ≥ 15 mg/L. However, no cases of irreversible renal damage were reported. Current data on the effectiveness of higher vancomycin trough levels in the treatment of MRSA infections are limited to few prospective and mainly retrospective studies. Our findings support the current recommendations for maintaining vancomycin trough levels of ≥ 15 mg/L in the treatment of severe MRSA infections, although no difference in all-cause mortality was observed.

Predicting Clostridium difficile infection in diabetic patients and the effect of metformin therapy: a retrospective, case-control study

Data on risk factors for Clostridium difficile infection (CDI) in diabetic patients are scarce. Recently, it has been shown that metformin increases the Bacteroidetes/Firmicutes ratio; therefore, it may yield a protective effect against CDI. We aimed to assess risk factors for CDI in diabetic patients beyond antibiotic treatment, and to determine the impact of metformin therapy on the development of CDI in these patients. In this retrospective, case-control study, all consecutive CDI diabetic patients, from January 2009 to December 2013, were included and compared to consecutive diabetic patients without CDI, hospitalized during the same period and in the same departments. Of 7,670 patients tested for C. difficile toxins, 486 were diabetics. Of them, 150 (30.8 %) were positive for C. difficile toxins and 336 (69.1 %) were negative. On multivariate analysis, metformin treatment was associated with a significant reduction in CDI [odds ratio (OR) = 0.58; 95 % confidence interval (CI), 0.37-0.93; p = 0.023], while heart failure was associated with significantly higher rates of CDI (OR = 1.654; 95 % CI, 1.007-2.716; p = 0.047), together with poor functional status, previous hospitalization, and abdominal surgery. Our findings suggest that, in diabetic patients, in addition to the well-recognized risk factors, heart failure is an additional risk factor for CDI, while metformin treatment seems to have a protective effect against the development of CDI. The exact mechanisms underlying this protective effect remain to be fully understood.

The role of FDG-PET/CT imaging in early detection of extra-cardiac complications of infective endocarditis

The exact incidence of extra-cardiac complications (ECC) in patients with infective endocarditis (IE) is unknown but presumed to be high. These patients, although mostly asymptomatic, may require a more aggressive therapeutic approach. (18)fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) is used for the diagnosis of infections, but its role in the early diagnosis of IE complications is still unclear. This study aimed to evaluate the role of FDG-PET/CT in the early diagnosis of ECC in IE and its implications for medical management. We prospectively studied 40 consecutive patients with a confirmed diagnosis of IE (according to the modified Duke criteria) who underwent a whole body FDG-PET/CT study within 14 days from diagnosis. The FDG-PET/CT demonstrated ECC in 17 (42.5%) patients, while 8 (38.1%) of them were asymptomatic. The most frequent embolic sites were musculoskeletal and splenic. Owing to the FDG-PET/CT findings, treatment planning was modified in 14 (35%) patients. This included antibiotic treatment prolongation (27.5%), referral to surgical procedures (15%) and, most substantially, prevention of unnecessary device extraction (17.7%). According to our experiences, FDG-PET/CT imaging was useful in the detection of embolic and metastatic infections in IE. This clinical information had a significant diagnostic and therapeutic impact in managing IE disease.

Monomicrobial necrotizing fasciitis in a single center: the emergence of Gram-negative bacteria as a common pathogen

BACKGROUND

Necrotizing fasciitis (NF) is a life-threatening soft tissue infection. It is usually caused by Streptococcus pyogenes and other Gram-positive bacteria. Several reports, however, emphasize the importance of Gram-negative rods in this infection.

METHODS

We retrospectively studied all cases of monomicrobial necrotizing fasciitis hospitalized in our center during the years 2002-2012. We compared clinical characteristics and outcomes of patients with Gram-negative versus Gram-positive infection.

RESULTS

Forty-five cases were reviewed, 19 caused by Gram-negative organisms, 10 of them Escherichia coli, and 26 caused by Gram-positive organisms, 10 of them S. pyogenes. Compared to Gram-positive infections, patients with Gram-negative infections were more likely to have a baseline malignancy (9/19, 47.4%) or to have undergone recent surgery (4/19, 42.3%). The 30-day mortality was higher among Gram-negative infected patients (8/19, 42.1% vs. 8/26, 30.8%). Creatine phosphokinase (CPK) was elevated in a minority of patients with Gram-negative necrotizing fasciitis, and its absolute value was lower than in Gram-positive necrotizing fasciitis.

CONCLUSIONS

In our center, 42% of monomicrobial necrotizing fasciitis cases were found to be caused by Gram-negative organisms, mostly E. coli. These infections usually appeared in immunocompromised or postoperative patients, often presented with normal CPK levels, and were associated with high mortality rates.

Effect of feeding hemp seed and hemp seed oil on laying hen performance and egg yolk fatty acid content: evidence of their safety and efficacy for laying hen diets

Forty-eight 19-wk-old Bovan White laying hens were fed 1 of 5 diets containing either hemp seed (HS) or hemp seed oil (HO). The level of HO was 4, 8, or 12%, whereas the level was 10 or 20% for the HS. A set of 8 birds fed wheat-, barley-, and corn oil-based diets served as the control. Performance was monitored over 12 wk. Average hen-day egg production was not affected upon feeding of either HS or HO diets. Egg weight was higher than that of the controls for hens consuming the 20% HS diet (P < 0.05). Feed intake was lower than that of the controls for birds consuming the 4% HO diet but similar across other treatments. Final BW were not affected by diet, with the exception of being lower than that of the controls (P < 0.05) in hens consuming the 12% HO diet. The total egg yolk n-3 fatty acid content increased linearly (P < 0.05) with increasing dietary α-linolenic acid provision with the HS- or HO-based diets. A quadratic response (P < 0.05) was observed for docosahexaenoic acid levels in egg yolk in response to increasing dietary α-linolenic acid supply. The expression of hepatic fatty acid desaturase 1 and 2, key genes for the desaturation of long-chain polyunsaturated fatty acids, was significantly decreased (50-60% of controls; P < 0.05) as a result of feeding HS or HO diets. Based on the results from the current study, the inclusion of the hemp products HS or HO in the diets of laying hens up to a maximum level of 20 and 12%, respectively, does not adversely effect the performance of laying hens and leads to the enrichment of the n-3 fatty acid content of eggs.

Organ transplantation from a donor colonized with a multidrug-resistant organism: a case report

The number of intensive care unit patients with infections caused by multidrug-resistant organisms is increasing in most developed countries. We report the case of a deceased multiorgan donor, who was an asymptomatic carrier of carbapenem-resistant Klebsiella pneumoniae (CR-KP) in the respiratory tract, a condition that was not diagnosed before organ harvesting and transplantation. The outcome of the 2 kidney recipients, the liver recipient, and 1 of the lung recipients was uneventful; in particular, no evidence of infection transmission or adverse graft outcomes was noted. The other lung recipient had a complicated postoperative course and, 4 weeks post transplantation, he developed a bacteremic pneumonia with CR-KP from which he subsequently died. These results suggest that, in well defined conditions, organs from donors who are CR-KP positive may be considered for transplantation.

Hippocampal microcircuit dynamics probed using optical imaging approaches

Mammalian cortical structures are endowed with the capacity for plasticity, which emerges from a combination of the dynamics of circuit connectivity and function, and the intrinsic function of the neurons within the circuit. However, this capacity is accompanied by a significant risk: the capability to generate seizure discharges is also a property of all mammalian cortices. How do cortical circuits reconcile the requirement to maintain plasticity, but at the same time control seizure initiation? These issues come into particular focus in the hippocampus. The hippocampus is one of the main plasticity engines in the brain, and is also a structure frequently implicated in the generation of epileptic seizures, with temporal lobe epilepsy constituting the most prevalent form of epilepsy in the adult population. One aspect of hippocampal circuitry that is particularly prominent is its intimate interconnections with the entorhinal cortex. These interconnections create a number of excitatory synaptic loops within the limbic system, which, in addition to being important in cognitive function, can support reentrant activation and seizure generation. In the present review, using optical imaging approaches to elucidate circuit processing at high temporal and spatial resolution, we examine how two targets of entorhinal cortical input within the hippocampus, the dentate gyrus and area CA1, regulate these synaptic pathways in ways that can maintain functions important in generation of normal activity patterns, but that dampen the ability of these inputs to generate seizure discharges.

[Intraarticular fractures of the proximal interphalangeal joint: dynamic early functional therapy with an external fixation system]

The results of treating fracture dislocations of the proximal interphalangeal joint are often unsatisfactory for the patient because conservative methods cannot prevent stiffness of the joint. Thus, early functional treatment with external fixation systems is increasingly favoured. This therapy combines the principles of ligamentotaxis and the possibility of early movement of the injured joint. The frequently modified pins and rubbers traction system is especially effective. It is cheap, easy to apply, and well accepted by patients due to its light weight and small size. This paper gives an overview of the therapeutic options and the clinical results of treating fractures of the proximal interphalangeal joint.

3He spin-dependent cross sections and sum rules

We present a measurement of the spin-dependent cross sections for the 3He over -->(e over -->,e')X reaction in the quasielastic and resonance regions at a four-momentum transfer 0.1< or =Q2< or =0.9 GeV2. The spin-structure functions have been extracted and used to evaluate the nuclear Burkhardt-Cottingham and extended Gerasimov-Drell-Hearn sum rules for the first time. The data are also compared to an impulse approximation calculation and an exact three-body Faddeev calculation in the quasielastic region.