Intravascular Infections Research Articles

Subcutaneous implantable cardioverter defibrillator in cardiomyopathies and channelopathies.

: Cardiomyopathies and channelopathies are heterogeneous disorders that increase the risk of sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) therapy is safe and effective for preventing SCD in patients at risk for malignant ventricular arrhythmias. Because of the poor positive predictive value of current risk stratification tools, the majority of patients implanted with an ICD will never receive a life-saving therapy but will be exposed to the risk of complications such as device infection, lead failure and inappropriate therapy. Subcutaneous ICD (S-ICD) now constitutes a valuable alternative to conventional transvenous ICD in patients with cardiomyopathies and channelopathies as it provides protection from SCD while avoiding the risks of intravascular lead infection or failure. This may be particularly advantageous for young patients with a very long life expectancy. On the other hand, S-ICD cannot deliver antitachycardia pacing or antibradycardia pacing. The purpose of this article is to review the available evidence and the future perspectives of S-ICD therapy in patients with cardiomyopathies or channelopathies.

Heartfelt sepsis: microvascular injury due to genomic storm.

Sepsis is one of the ten leading causes of death in developed and developing countries. In the United States, sepsis mortality approaches that of acute myocardial infarction and exceeds deaths from stroke. Neonates and the elderly are the most vulner-able patients, with these groups suffering from the highest sepsis mortality. In both groups, many survivors respectively display serious developmental disabilities and cognitive decline. The National Institute of Health/National Heart, Lung, and Blood Institute Panel redefined sepsis as a "severe endothelial dysfunction syndrome in response to intravascular and extravascular infections causing reversible or irreversible injury to the microcirculation responsible for multiple organ failure." Microvas-cular endothelial injury in sepsis due to microbial inflammation encompasses small blood vessels (< 100 μm in diameter). While the lungs remain the principal organ of interest due to sepsis-associated acute respiratory distress syndrome, "septic heart" or "septic cardiomyopathy" accelerates sepsis' transition to potentially lethal septic shock. This review analyses both new advances in understanding the septic mechanism and possible resolutions of sepsis. The concept of a "genomic storm," caused by microbes triggering florid production of inflammatory mediators, is based on septic reprogramming of the human genome. This genomic storm leads to microvascular endothelial injury, persistent hypotension, and organ failure. While very early control of sepsis-causing bacterial, fungal and viral infections remains crucial for the treatment of sepsis, supportive measures are likewise necessary to maintain blood pressure, respiration, and kidney function. New evidence indicates that preadmission b-blockers may reduce sepsis-associated mortality. The fundamental role of nuclear signalling in the progres-sion and resolution of sepsis was established with a new class of cell-penetrating nuclear transport modifiers (NTMs). NTMs target the translocation of proinflammatory and metabolic transcription factors to the cell's nucleus while also enhancing bacterial clearance in experimental polymicrobial sepsis models. The result is a 700-fold reduction in the bacterial burden of the lungs and improvement of sepsis-associated thrombocytopaenia and blood markers of endothelial injury. When added to anti-microbial therapy, NTM has increased survival from 30% to 55%, when compared to antimicrobial therapy alone. Yet, the prevention of sepsis remains the most rational and beneficial path. Anti-pneumococcal vaccination has reduced the incidence of pneumonia and sepsis caused by increasingly antibiotic-resistant Streptococcus pneumoniae in all age groups. Similarly, the incidence of meningococcal sepsis known as "purpura fulminans" has been reduced by a recently approved vaccine thereby preventing hearing loss, neurologic damage, and limb amputations in young survivors of septic outbreaks. We urgently need further preventive, diagnostic, and therapeutic measures as the tide of sepsis rises in the United States and around the world.

Comparison of the structures of the medical staff and the operation situations of the departments of critical care medicine between the provincial and county level hospitals of Guizhou Province in 2017

To understand the situations of departments of intensive care units (ICUs) of different level hospitals in Guizhou Province, and to provide directions and evidences for improving quality control in critical care medicine. A county-level hospital and a provincial-level hospital's comprehensive ICU in Guizhou Province were selected to record and analyze and compare the structural indicators, patient admission and transfer, disease distribution, ventilator associated pneumonia (VAP), intravascular catheter related blood stream infection (CRBSI) and catheter-associated urinary tract infection (CAUTI) of the two hospitals' comprehensive ICU in 2017. The ICU of the People's Hospital of Suiyang County (county hospital) was found in 2012, and the ICU of the Affiliated Hospital of Guizhou Medical University (provincial hospital) was found in 1994. Until 2017, there were 10 and 46 beds, 6 (all of them hold bachelor's degree) and 18 physicians (6 of them hold PhD, 5 of them hold master's degree, 7 of them hold bachelor's degree), 17 (4 of them hold bachelor's degree, 13 of them hold college degree or graduated from secondary school) and 69 nurses (2 of them hold master's degree, 53 of them hold bachelor's degree, 14 of them hold college degree or graduated from secondary school) in the two ICUs respectively, there were significant differences in the education background of the physicians and nurses between the two ICUs (both P < 0.01). During 2017, 471 cases were admitted to the ICU of the county hospital while 1 633 cases were admitted to the ICU of the provincial hospital. Compared with the ICU of the provincial hospital, the ratio of the patients with acute physiology and chronic health evaluation II (APACHE II) ≥ 15 at admission was lower (74.8% vs. 85.1%, P < 0.01), the ratio of direct admission was higher (30.8% vs. 17.4%, P < 0.01), the ratio of the patients admitted to the ICU more than once was lower (0.8% vs. 5.0%, P < 0.01), the ratio of the patients whose the length of ICU stay less than 24 hours was higher (51.6% vs. 13.7%, P < 0.01), the ratio of the patients whose the length of ICU stay more than 28 days was lower (1.1% vs. 2.9%, P < 0.05), the ratio of the patients discharged against-advice (25.5% vs. 20.5%, P < 0.05) was higher, the ratio of the patients transferred to other hospitals was higher (5.1% vs. 0.3%, P < 0.05), and the ICU mortality was lower (4.0% vs. 13.9%, P < 0.01) in the ICU of the county hospital. The top three kinds of diseases treated in the ICU of the county hospital were brain injury (27.4%), trauma (19.1%) and toxication (6.8%); while in the ICU of the provincial hospital were brain injury (18.6%), sepsis (16.2%) and severe acute pancreatitis (4.8%). In addition, the incidences of VAP, CRBSI and CAUTI in the ICU of the county hospital were 10.0/1 000 ventilator days, 1.4/1 000 catheter days, 0.5/1 000 catheter days; while in the ICU of the provincial hospital were 5.8/1 000 ventilator days, 2.0/1 000 catheter days, 3.7/1 000 catheter days, respectively. There are short of physicians and nurses in the ICU of the provincial and county hospitals in Guizhou Province, and the educational level of the medical staff in the ICU of the county hospital is relatively low. Moreover, there were significant differences in the admissions and treatments and the outcomes of the critically ill patients between the two ICUs. The characteristics of the ICUs of county hospitals should be fully considered when the quality control of critical care medicine and continuing medical education are done.

Novel Treatment of Staphylococcus aureus Device-Related Infections Using Fibrinolytic Agents.

Staphylococcal infections involving biofilms represent a significant challenge in the treatment of patients with device-related infections. Staphylococcus aureus biofilms have been shown to be SaeRS regulated and dependent on the coagulase-catalyzed conversion of fibrinogen into fibrin on surfaces coated with human plasma. Here we investigated the treatment of staphylococcal biofilm device-related infections by digesting the fibrin biofilm matrix with and without existing antimicrobials. The fibrinolytic agents plasmin, streptokinase, and nattokinase, and TrypLE, a recombinant trypsin-like protease, were used to digest and treat S. aureus biofilms grown in vitro using in vivo-like static biofilm assays with and without antimicrobials. Cytotoxicity, the potential to induce a cytokine response in whole human blood, and the risk of induction of tolerance to fibrinolytic agents were investigated. A rat model of intravascular catheter infection was established to investigate the efficacy of selected fibrinolytic agents in vivo Under biomimetic conditions, the fibrinolytic agents effectively dispersed established S. aureus biofilms and, in combination with common antistaphylococcal antimicrobials, effectively killed bacterial cells being released from the biofilm. These fibrinolytic agents were not cytotoxic and did not affect the host immune response. The rat model of infection successfully demonstrated the activity of the selected fibrinolytic agents alone and in combination with antimicrobials on established biofilms in vivo TrypLE and nattokinase most successfully removed adherent cells from plasma-coated surfaces and significantly improved the efficacy of existing antimicrobials against S. aureus biofilms in vitro and in vivo These biofilm dispersal agents represent a viable future treatment option for S. aureus device-related infections.

Multiple-Dose Oritavancin Evaluation in a Retrospective Cohort of Patients with Complicated Infections.

Oritavancin is a lipoglycopeptide antibiotic approved for use in acute bacterial skin and skin structure infections as a single 1200-mg parenteral dose. Because of oritavancin's long half-life and broad gram-positive activity, interest in its use for other infections is high. This study is a retrospective cohort evaluation of patients receiving oritavancin at a single academic medical center. All patients receiving more than one dose of oritavancin were included. Patients were excluded if therapy was interrupted by more than 14 days. Efficacy, defined a priori as clinical success, improvement, or failure, and adverse drug effect outcomes were collected. Seventeen patients received multiple oritavancin doses (range 2-18 doses) for the treatment of complicated infections including osteomyelitis, surgical site infection, intravascular infections, and pneumonia. All patients achieved clinical success or improvement with oritavancin. Four patients (24%) had an adverse event requiring oritavancin discontinuation that reversed rapidly. Off-label oritavancin use may be a safe and effective alternative to daily antibiotic infusions to treat complicated infectious disease processes. This study is limited by small sample size and retrospective design, but it provides information on using oritavancin in these complex gram-positive infections.

Chitosan-based coatings in the prevention of intravascular catheter-associated infections.

Central venous access devices play an important role in patients with prolonged intravenous administration requirements. In the last years, the coating of these devices with bactericidal compounds has emerged as a potential tool to prevent bacterial colonization. Our study describes the modification of 3D-printed reservoirs and silicone-based catheters, mimicking central venous access devices, through different approaches including their coating with the well known biocompatible and bactericidal polymer chitosan, with the anionic polysaccharide alginate; also, plasma treated surfaces were included in the study to promote polymer adhesion. The evaluation of the antimicrobial action of those surface modifications compared to that exerted by a model antibiotic (ciprofloxacin) adsorbed on the surface of the devices was carried out. Surface characterization was developed by different methodologies and the bactericidal effects of the different coatings were assayed in an invitro model of Staphylococcus aureus infection. Our results showed a significant reduction in the reservoir roughness (≤73%) after coating though no changes were observed for coated catheters which was also confirmed by scanning electron microscopy, pointing to the importance of the surface device topography for the successful attachment of the coating and for the subsequent development of bactericidal effects. Furthermore, the single presence of chitosan on the reservoirs was enough to fully inhibit bacterial growth exerting the same efficiency as that showed by the model antibiotic. Importantly, chitosan coating showed low cytotoxicity against human keratinocytes, human lung adenocarcinoma epithelial cells, and murine colon carcinoma cells displaying viability percentages in the range of the control samples (>95%). Chitosan-based coatings are proposed as an effective and promising solution in the prevention of microbial infections associated to medical devices.

Intravascular catheter bloodstream infections: an effective and sustained hospital-wide prevention program over 18 years

Intravascular catheter bloodstream infections: an effective and sustained hospital-wide prevention program over 18 years

Impact of a rapid molecular test for positive blood cultures from neonatal intensive care patients on clinical management: a retrospective audit.

Both Staphylococcus aureus and coagulase negative Staphylococci are common causes of late-onset neonatal sepsis in the neonatal intensive care unit (NICU), usually relating to intravascular access device infections. This project aimed to review the impact on antimicrobial treatment and clinical outcome in the NICU setting, of the introduction of the Xpert MRSA/SA BC test (Cepheid, USA) for the identification of staphylococci in blood cultures. A retrospective audit was carried out of the pre- and post-intervention periods; the intervention was the introduction of the Xpert MRSA/SA BC test. In total, 88 neonates had positive blood cultures with Staphylococcus spp., comprising 42 neonates in the pre-intervention and 46 in the post-intervention groups. The pre-intervention group had a higher birth weight (1.541kg vs. 1.219kg, p=0.05) and higher platelet count (288 vs. 224×109/L, p=0.05). There was a trend towards a shorter duration of antimicrobial therapy in term infants and in the length of admission; however, this was not statistically significant (p=0.2). All of the nine infants post-intervention with significant bacteraemia (S. aureus =3, CoNS =6) were changed to the optimal antimicrobial at the time the result was available. This study shows that the introduction of the Xpert MRSA/SA BC test can lead to a reduction in the length of admission and duration of antimicrobials in term infants; however, the difference was not statistically significant. All nine infants with clinically significant bacteraemia were treated with the appropriate antimicrobial when the Xpert MRSA/SA BC test result was available.

Biodistribution and residence time of adenovector serotype 5 in normal and immunodeficient mice and rats detected with bioluminescent imaging

As concerns increase about adenovirus type 5 (Ad5) being a safe gene transfer vector, it is important to evaluate its distribution, residence time, and possible toxicity in immunodeficient populations. To characterize the potential risk associated with different Ad5 vector delivery modes, we used immunocompetent and immunodeficient Rag2−/− animals to establish mouse and rat models that could be monitored with bioluminescent imaging following intramuscular or intravascular infection with an engineered replication-incompetent Ad5 virus carrying the firefly luciferase gene (Ad5-Fluc). The Ad5 vector was less well-tolerated by Rag2−/− animals than by wildtype ones, with delayed residence time, wider virus dissemination, less weight gain, and relatively severe pathological changes. In intravascularly Ad5-Fluc-infected Rag2−/− mice, systemic virus dissemination extended from the abdomen to the limbs and head on day 9 post-infection. Additionally, significant increases in plasma TNF-α and IFN-γ, which may be important factors in the heightened immunopathology in the liver and brain, were detected in the Rag2−/− mice 30 days after intravascular delivery. The Ad5 vector was better tolerated after intramuscular delivery than after intravascular delivery. Ad5-Fluc/Rag2−/− mice and rats can be used as reliable models of an immunodeficient population in which to evaluate the safety of Ad5-vectored vaccines or gene therapy products.

Hematogenous vertebral osteomyelitis associated with intravascular device-associated infections – A retrospective cohort study

IntroductionAim of the study was to investigate the clinical, microbiological, radiological, and treatment characteristics of hematogenous vertebral osteomyelitis originating from infected intravascular devices. Patients and MethodsPatients with secondary hematogenous vertebral osteomyelitis caused by an infected intravascular device were included in this retrospective cohort study. Patients with prior spinal surgery were excluded. Categorical variables were compared using χ2 or Fisher's exact tests and continuous variables using the Mann–Whitney U test. ResultsSixty-seven patients with hematogenous vertebral osteomyelitis were included. Intravenous catheters were the source of infection in 45 patients (67%) and cardiovascular devices in 22 (33%). Fever was present in 21 patients (45%). The main pathogens were coagulase-negative staphylococci, isolated in 42 patients (63%), which grew from blood culture in 52 patients (87%), from vertebral tissue in 29 patients (56%) and from the explanted intravascular device in 18 patients (60%), where it was sampled. Infective endocarditis was diagnosed in 14 of 45 patients (31%), more common with cardiovascular devices than with intravascular catheters (56% versus 15%; P=0.008). ConclusionsIn patients with vertebral osteomyelitis, growth of coagulase-negative staphylococci in blood is highly suggestive for intravascular device-associated infection. Despite absence of systemic or local signs of inflammation at the site of the device, blood cultures should be collected and echocardiography performed in these patients.

Treatment of Staphylococcus aureus Infections.

Staphylococcus aureus, although generally identified as a commensal, is also a common cause of human bacterial infections, including of the skin and other soft tissues, bones, bloodstream, and respiratory tract. The history of S. aureus treatment is marked by the development of resistance to each new class of antistaphylococcal antimicrobial drugs, including the penicillins, sulfonamides, tetracyclines, glycopeptides, and others, complicating therapy. S. aureus isolates identified in the 1960s were sometimes resistant to methicillin, a ß-lactam antimicrobial active initially against a majority S. aureus strains. These MRSA isolates, resistant to nearly all ß-lactam antimicrobials, were first largely confined to the health care environment and the patients who attended it. However, in the mid-1990s, new strains, known as community-associated (CA-) MRSA strains, emerged. CA-MRSA organisms, compared with health care-associated (HA-) MRSA strain types, are more often susceptible to multiple classes of non ß-lactam antimicrobials. While infections caused by methicillin-susceptible S. aureus (MSSA) strains are usually treated with drugs in the ß-lactam class, such as cephalosporins, oxacillin or nafcillin, MRSA infections are treated with drugs in other antimicrobial classes. The glycopeptide drug vancomycin, and in some countries teicoplanin, is the most common drug used to treat severe MRSA infections. There are now other classes of antimicrobials available to treat staphylococcal infections, including several that have been approved after 2009. The antimicrobial management of invasive and noninvasive S. aureus infections in the ambulatory and in-patient settings is the topic of this review. Also discussed are common adverse effects of antistaphylococcal antimicrobial agents, advantages of one agent over another for specific clinical syndromes, and the use of adjunctive therapies such as surgery and intravenous immunoglobulin. We have detailed considerations in the therapy of noninvasive and invasive S. aureus infections. This is followed by sections on specific clinical infectious syndromes including skin and soft tissue infections, bacteremia, endocarditis and intravascular infections, pneumonia, osteomyelitis and vertebral discitis, epidural abscess, septic arthritis, pyomyositis, mastitis, necrotizing fasciitis, orbital infections, endophthalmitis, parotitis, staphylococcal toxinoses, urogenital infections, and central nervous system infections.

5-Hydroxyethyl-3-tetradecanoyltetramic acid represents a novel treatment for intravascular catheter infections due to Staphylococcus aureus.

Objectives: Biofilm infections of intravascular catheters caused by Staphylococcus aureus may be treated with catheter lock solutions (CLSs). Here we investigated the antibacterial activity, cytotoxicity and CLS potential of 5-hydroxyethyl-3-tetradecanoyltetramic acid (5HE-C14-TMA) compared with the related compounds 3-tetradecanoyltetronic (C14-TOA) and 3-tetradecanoylthiotetronic (C14-TTA), which are variants of quorum sensing signalling molecules produced by Pseudomonas aeruginosa. Methods: Antibacterial activity and mechanism of action of 5HE-C14-TMA, C14-TOA and C14-TTA were determined via MIC, bacterial killing, membrane potential and permeability assays. Susceptibility of S. aureus biofilms formed in the presence of plasma in vitro was investigated, MTT cytotoxicity testing was undertaken and cytokine release in human blood upon exposure to 5HE-C14-TMA and/or S. aureus biofilms was quantified. The effectiveness of 5HE-C14-TMA as CLS therapy in vivo was assessed using a rat intravascular catheter biofilm infection model. Results: MICs of 5HE-C14-TMA, C14-TOA and C14-TTA ranged from 2 to 4 mg/L. 5HE-C14-TMA and C14-TTA were bactericidal; all three compounds perturbed the staphylococcal membrane by increasing membrane permeability, depolarized the transmembrane potential and caused ATP leakage. Cytotoxicity and haemolytic activity were compound and target cell type-dependent. 5HE-C14-TMA reduced S. aureus biofilm viability in a dose-dependent manner in vitro and in vivo and did not trigger release of cytokines in human blood, but inhibited the high levels of IL-8 and TNF-α induced by S. aureus biofilms. Conclusions: 5HE-C14-TMA, C14-TOA and C14-TTA are membrane-active agents. 5HE-C14-TMA was the most potent, eradicating S. aureus biofilms at 512–1024 mg/L both in vitro and in vivo as a CLS.

Achromobacter Bacteremia in Patients With Cancer

Background Achromobacter species are Gram-negative waterborne bacteria that occasionally cause bacteremia primarily in immunocompromised hosts. Cancer patients have increased risk due to their use of intravascular catheters and immunosuppression from neoplasm, chemotherapy, and prolonged steroids. In this study, we investigated the clinical characteristics of cancer patients with Achromobacter bacteremia and identified risk factors, outcomes, and susceptibility patterns in this selective population. Methods We retrospectively reviewed all cases of Achromobacter bacteremia occurring from March 2010 to March 2015 at Moffitt Cancer Center. Data collected included age, sex, comorbidities, underlying malignancy, neutropenia status, prior bacteremia, treatment course, and patterns of susceptibilities of the isolates. We also reviewed outcomes such as discharge disposition and death. Results Eleven patients were identified with positive blood cultures for Achromobacter species. Central venous catheters were infected in 9 patients (82%), and 2 patients had recurrent bacteremia, which resolved after removal of the catheter. Eight (73%) patients had a history of prior bacteremia. Patients were treated with meropenem (n = 4), piperacillin/tazobactam (n = 3), cefepime, ceftazidime, and trimethoprim-sulfamethoxazole (TMP-SMX). The isolates were susceptible to meropenem (8 of 8 isolates), piperacillin/tazobactam (10 of 10), ceftazidime (7 of 7), and TMP-SMX (8 of 8). Most of isolates were resistant to aminoglycosides and fluoroquinolones. Conclusions The major predisposing factors for Achromobacter bacteremia were infected intravascular catheters and prior history of bacteremia. Infections can be treated with piperacillin/tazobactam, a carbapenem, or TMP-SMX. Compared with other studies, we observed similar risk factors and morbidity but with a higher rate of intravascular catheter infections.

The remarkably multifunctional fibronectin binding proteins of Staphylococcus aureus.

Staphylococcus aureus expresses two distinct but closely related multifunctional cell wall-anchored (CWA) proteins that bind to the host glycoprotein fibronectin. The fibronectin binding proteins FnBPA and FnBPB comprise two distinct domains. The C-terminal domain comprises a tandem array of repeats that bind to the N-terminal type I modules of fibronectin by the tandem β-zipper mechanism. This causes allosteric activation of a cryptic integrin binding domain, allowing fibronectin to act as a bridge between bacterial cells and the α5β1 integrin on host cells, triggering bacterial uptake by endocytosis. Variants of FnBPA with polymorphisms in fibronectin binding repeats (FnBRs) that increase affinity for the ligand are associated with strains that infect cardiac devices and cause endocarditis, suggesting that binding affinity is particularly important in intravascular infections. The N-terminal A domains of FnBPA and FnBPB have diverged into seven antigenically distinct isoforms. Each binds fibrinogen by the 'dock, lock and latch' mechanism characteristic of clumping factor A. However, FnBPs can also bind to elastin, which is probably important in adhesion to connective tissue in vivo. In addition, they can capture plasminogen from plasma, which can be activated to plasmin by host and bacterial plasminogen activators. The bacterial cells become armed with a host protease which destroys opsonins, contributing to immune evasion and promotes spreading during skin infection. Finally, some methicillin-resistant S. aureus (MRSA) strains form biofilm that depends on the elaboration of FnBPs rather than polysaccharide. The A domains of the FnBPs can interact homophilically, allowing cells to bind together as the biofilm accumulates.

Understanding biofilm formation in intravascular device-related infections.

Here we will describe the different steps of bacterial biofilm formation on intravascular catheters and strategies that can be developed to avoid or reduce their clinical consequences. Such a physiopathologic scheme can also be applied to the formation of biofilm on other intravascular devices such as cardiac prosthetic valves or pacemakers.

Infectious Complications after Major Abdominal Cancer Surgery: In Search of Improvable Risk Factors.

Major resections for esophageal, gastric, hepatic, pancreatic, and colorectal cancer continue to be associated with a high peri-operative morbidity of up to 30%-40%. To a large extent, this morbidity is caused by infectious complications that add up to a considerable burden to patients and hospital costs. The objective of this large retrospective cross-sectional study was to determine independent patient and operation-related risk factors for infectious complications after major abdominal cancer operations to elucidate how infection rates can be reduced and improve health-care quality. In 1,389 cancer patients who underwent a major resection procedure between 2009 and 2013, infectious complications and their independent determinants were analyzed by multivariable logistic regression (p < 0.05). Male gender was a risk factor for infections in general, whereas patients ≥65 y (odds ratio [OR] 1.75; p = 0.008), urinary tract infection (OR 0.51; p = 0.004), American Society of Anesthesiologists score (OR 1.55; p = 0.004), overall (OR 1.70; p = 0.037), vascular (OR 1.59; p = 0.020), and neurologic comorbidity (OR 2.22; p = 0.001) were associated significantly with pneumonia. Intra-abdominal drainage (OR 1.41; p = 0.024) and a duration of surgery of ≥180 min (OR 1.85; p = 0.001) were risk factors for surgical site infections. Total parenteral nutrition was significantly associated with intravascular catheter-induced infections (OR 18.09; p < 0.001) and sepsis (OR 6.69; p < 0.001). In this study, several independent risk factors for infectious complications in major abdominal cancer operations were identified, providing opportunities for further reducing peri-operative infections. General awareness and focus on preventing infectious complications may have a significant impact on health-care outcomes and costs.

Prevention of Hospital-Acquired Infections.

Hospital-acquired infections (HAIs) are a persistent concern and include surgical site infections, intravascular line-associated infections, pneumonia, catheter-associated urinary tract infections, and C. difficile infection. Review of the pertinent English-language literature. Hospital-acquired infections result in significant increases in morbidity, mortality rates, and cost and are a focus of efforts at reduction. I discuss efforts specific to each of the most common infections and a philosophical approach to prevention that strives to achieve zero potentially preventable hospital-acquired infections.

LMOh7858_0369, a gene encoding a putative leucine-rich repeat-containing protein, is required for virulence of Listeria monocytogenes.

Listeria monocytogenes possesses the highest number of leucine-rich repeat (LRR)-containing proteins among all Gram-positive bacteria; these LRR-containing molecules are known as the 'internalin' family. To understand the functions of largely uncharacterized LRR-containing molecules, we constructed seven deletion mutants in the L. monocytogenes H7858 strain targeting genes in this family and tested their virulence. Among the seven mutants, the ΔLMOh7858_0369 strain and the ΔLMOh7858_2546 strain showed significantly impaired invasiveness of HepG2 cells. We further tested the virulence of these two strains in the intravascular sepsis model using BALB/c mice. Interestingly, the ΔLMOh7858_0369 strain showed significant reduction in organ colonization, bacteremia and invasion of the brain compared with the parental wild-type strain. Host immune responses to listerial intravascular infection were measured at 24 and 72 h post-infection. Transcript levels of several proinflammatory cytokines and chemokines were significantly lower when induced by the ΔlmOh7858_0369 strain than when induced by the wild type. These results suggest that the putative LRR-containing protein encoded by LMOh7858_0369 might be a novel virulence factor of the L. monocytogenes H7858 strain.

Impact of definition and procedures used for absent blood culture data on the rate of intravascular catheter infection during parenteral nutrition

Diagnosis of intravascular catheter infection may be affected by the definition and procedures applied in the absence of blood culture data. To examine the extent to which different definitions of catheter infection and procedures for handling absent blood culture data can affect reported catheter infection rates. Catheter infection rates were established in a cohort of hospitalized patients administered parenteral nutrition according to three clinical and four published definitions. Paired and unpaired comparisons were made using available case analyses, sensitivity analyses and intention-to-categorize analyses. Complete data were available for each clinical definition (N=193), and there were missing data (4.1-26.9%) for the published definitions. In an available case analysis, the catheter infection rate was 13.0-36.8% for the clinical definitions and 2.1-12.4% for the published definitions. For the published definitions, the rate was 1.6-32.1% in a sensitivity analysis and 11.4-16.9% in an intention-to-categorize analysis, with suggestion of bias towards a higher catheter infection rate in those with missing data, in keeping with the analyses of the clinical definitions. For paired comparisons, the strength of agreement between definitions varied from 'poor' (Cohen's kappa <0.21) to 'very good' (Cohen's kappa ≥0.81). The use of different definitions of catheter infection and procedures applied in the absence of blood culture data produced widely different catheter infection rates, which could compromise measurements or comparisons of service quality or study outcome. As such, there is a need to establish and use a valid, consistent and practical definition.

Spectrum of Severe Sepsis in Critically Ill Adult Patients of Bangladesh: A Prospective Observational study

Background: Severe sepsis is the leading cause to Intensive Care Unit (ICU) admission. However few studies have described the primary source of the severe sepsis in Bangladesh.Objectives: General objective was to identify the clinical presentation of infection in severe sepsis patients &amp; specific objective was to determine the primary and commonest source of infection in severe sepsis.Methods: This was a prospective cross sectional study done over seven months period starting from June 1, 2012 to December 31, 2012 in the dept. of Critical Care Medicine of BIRDEM General Hospital. All ICU admissions from the emergency department, medical and surgical in patients who were screened daily for the presence of severe sepsis or septic shock using a screening tool, which included definitions of sepsis and organ dysfunctions. All consecutive patients with severe sepsis were enrolled as study subjects.Results: A total of 228 patients were admitted in ICU and among them, 95 patients of severe sepsis were included . The mean age of the patients was 59.56 years &amp; male to female ratio being 3:2. Ninety two (92% ) patients had any kind of comorbidity. Commonest comorbidity was diabetes mellitus (77%). Respiratory, renal dysfunction, and cardiovascular, were the most frequent organ dysfunctions (87% , 64%, 58%, respectively). In severesepsis patients single organ dysfunction was 30 %, double organ dysfunction was also 30% &amp; triple organ dysfunction was 35% of patients. The most common primary source of infection were the respiratory system 70%, followed by urinary tract11% , intravascular catheter related infection 7% and abdomen 5%.Conclusion: Severe sepsis is a significant &amp; common health problem in ICU Patients of Bangladesh. An understanding of the primary sources of severe sepsis is vital for treatment and these information will allow us to make preventive strategy for severe sepsis.Bangladesh Crit Care J September 2015; 3 (2): 45-48