Early Bacterial Infection Research Articles

Infectious Complications and Mortality after Autologous Stem Cell Transplantation for Lymphomas: A Comparison Between HIV-Infected and HIV-Negative Patients

▪Introduction: Lymphomas continue to be a leading cause of death in HIV-positive patients (HIV+ pts) in the cART era. The aim of this study was to review our 15-year single institution experience in performing Autologous Stem Cell Transplantation (ASCT) for HIV-infected and non-HIV patients with high-risk or relapsed lymphomas, focusing on infectious complications.Patients and Methods: We retrospectively evaluated our cohort of 28 HIV+ pts who underwent an ASCT between 2000-2015, and compared it with a well-matched control group of 39 HIV-negative pts.Patient and ASCT characteristics are described in Table 1. All HIV+ pts were on cART. Chemomobilization was used in 60% of the HIV cohort and 84% of the controls. BEAM conditioning regimen was the most common. All transplants were performed in the same tertiary hospital JACIE-accredited SCT unit.The primary end points were first-year cumulative incidence (CI) of infection, total infectious episodes and infection-related mortality. For the analysis, we defined 3 different time frames: 1st Pre-engraftment; 2nd from engraftment to day +100 and 3rd from day +100 until 1 year after SCT. Events occurring during the first 2 periods were considered early infections as compared to late.Results:All patients received antiviral and anti-PJP prophylaxis, but a significantly higher proportion of HIV+ pts were given antibacterial and antifungal prophylaxis (2/3 vs 1/3 approximately, Table 1). G-CSF support was initiated in all HIV recipients and 66% of controls, and the median days of use was longer for the HIV group (7 vs 4 days, p= 0.04). Median time to neutrophil engraftment was similar in both groups (13 vs 11 days, p=0.55); 93% of HIV pts and all control pts reached ANC > 500c/uL by day +30.Infectious episodes (IE) are described in Table 2, divided by pathogen subtype and time frame. Globally, all infection subtypes were more common in the HIV-infected cohort at some point.The most significant findings from the analysis are as follows. CI of early global infections: HIV 75% vs non-HIV 25% (p= 0.04), Figure 1. Median number of global infectious events: HIV 65 vs non-HIV 39 (p= 0.002; OR 1.8 [1.2-2.8]). Bacteria: CI of pre-engraftment and early bacterial infections were not different among groups (42% vs 28%, p= 0.47), but the median number of bacterial episodes was clearly different: HIV 17 vs non-HIV 12 (p= 0.08; OR 2.16 [0.96-4.8]). Fungi: CI of early fungal infections: HIV 10.7% vs non-HIV 0% (p= 0.03); minor infections were not considered. Viruses: CI of early viral infections: HIV 46% vs non-HIV 15% (p= 0.004). Median nº of early viral IE: HIV 19 vs non-HIV 6 (p= 0.007; OR 4.16 [1.43-12]). CI of late viral infections: HIV 30% vs non-HIV 11.7% (p= 0.04). CMV reactivations were by far more common in the HIV cohort (p=0,01). HIV viral load bleeps were documented in 35% of the HIV patients (most commonly in the day +30 control) and one post-transplant virological failure was diagnosed, forcing HAART substitution.Of note, 1st year CI of infection-related mortality was 14% in the HIV group vs 0% in the non-HIV group (p= 0.01), Figure 2. Three HIV+ pts suffered early fulminant septic episodes (1 E. coli + Enterococcus, 1 Rothia mucilaginosa, 1 non-clarified - possible Stenotrophomonas maltophilia) and a 29-year old woman in CR after a 1st line for a stage IVsB Burkitt-like lymphoma died due to a severe influenza A pneumonia. Length of admission was also significantly longer for the HIV+ pts (median days 34 vs 28, p=0.041).Regarding long-term outcome, median follow up as of July 2016 is 82 months for the HIV+ group and 70 months for the control group: 57% and 61% of the pts in each cohort are still alive, respectively. One HIV-infected pt and 3 controls have been lost to follow-up. EFS: 1 year 71.4% vs 81.9% (ns); 5 years: 63.9% vs 66.5% (ns). Overall Survival: 1 year 75% vs 84% (ns); 5 years 66.3% vs 74.6% (ns).Conclusion: Autologous stem cell transplantation has been proven to be feasible and effective in HIV-related lymphomas, but in our experience and despite great advances in cART and virological control, HIV+ patients are at high risk of infection and this might influence post-ASCT short-term survival. It is mandatory to focus on prophylactic and supportive measures and to choose carefully the optimal timing for transplantation. [Display omitted] [Display omitted] [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Intravital excitation increases detection sensitivity for pulmonary tuberculosis by whole-body imaging with β-lactamase reporter enzyme fluorescence.

Tuberculosis is a pulmonary disease with an especially high mortality rate in immuno-compromised populations, specifically children and HIV positive individuals. The causative agent, Mycobacterium tuberculosis (Mtb), is a very slow growing and difficult organism to work with, making both diagnosis and development of effective treatments cumbersome. We utilize a fiber-optic fluorescence microendoscope integrated with a whole-body imaging system for in vivo Mtb detection. The system exploits an endogenous enzyme of Mtb (β-lactamase, or BlaC) using a BlaC-specific NIR fluorogenic substrate. In the presence of BlaC, this substrate is cleaved and becomes fluorescent. Using intravital illumination of the lung to excite this probe, sensitivity of the optical system increases over trans- and epi-illumination methods of whole-body fluorescence imaging. We demonstrate that integration of these imaging technologies with BlaC-specific fluorescent reporter probe improves the level of detection to ∼100 colony forming units, a 100× increase in sensitivity in comparison to epi-illumination and a 10× increase in sensitivity in comparison to previous work in intravital excitation of tdTomato-expressing Mtb. This lower detection threshold enables the study of early stage bacterial infections with clinical strains of Mtb and longitudinal studies of disease pathogenesis and therapeutic efficacy with multiple time points in a single animal.

Carbapenem-Resistant Klebsiella pneumoniae influences the outcome of early infections in liver transplant recipients.

BackgroundInfections remain a leading cause of morbidity and mortality among liver transplant (LT) recipients. The aim of our study was to define the factors associated with outcome of early bacterial and fungal infections in a cohort of patients who underwent LT at the University Hospital of Ancona over a nine year period.MethodsAll consecutive patients who underwent LT in our center were considered. An early infection was defined as occurring in the first month post-transplantation.ResultsAmong 330 patients who underwent LT from August 2005 to October 2014, 88 (27 %) had at least one infection documented within 30 days after transplantation. In 54 cases only one site was involved, in 34 cases ≥2 sites. There were 43 (30 %) pneumonia, 40 (27 %) surgical site infections, 31 (22 %) blood stream infections, and 30 (21 %) urinary tract infections. Gram-negative bacteria accounted for 64 % of the culture-positive cases, followed by Gram-positive bacteria (30 %) and fungi (6 %). A high proportion of drug-resistant strains was found within either Gram-negative (79 %) or Gram-positive (81 %) bacteria. There were 27 out 88 patients (31 %) who died within 180 days from the transplant. Factors independently associated with a higher risk of mortality were: renal replacement therapy (HR 11.797 [CI95 % 3.082–45.152], p < 0.0001), multisite infections (HR 4.865 [CI95 % 1.417–16.700], p = 0.012) and being infected with carbapenem-resistant Klebsiella pneumoniae (CRKP; HR 5.562 [CI95 % 1.186–26.088], p = 0.030).ConclusionsOverall, these data indicate that early infections in LT patients are characterized by significant mortality. In particular, an early infection caused by CRKP has an adverse impact on survival in these patients suggesting an urgent need for adopting preventive measures to avoiding this complication.

Cord blood transplantation in Japan.

Cord blood transplantation (CBT) has increasingly been used in Japan and the annual number of CBT now exceeds 1,200. The cumulative number of CBT reached 12,853 in 2015, accounting for almost 1/3 of total CBT performed worldwide. It is true that smaller body size and lower costs, as compared to western countries, have been advantages for Japanese people in using CB as graft alternative. In addition, several novel findings regarding serious issues following CBT have been obtained, which further enhanced the use of CB. First, several mechanisms of engraftment failure following CBT other than cell dose have been reported, such as the presence of donor-specific anti-HLA antibodies or the development of hemophagocytic syndrome. Second, unique profiles of infectious complications following CBT have been reported, such as higher incidences of early bacterial infections and HHV-6 encephalitis, as compared to those following bone marrow (BM)/peripheral blood (PB) transplants. Third, the incidence of disease relapse was comparable to those following BM/PB transplants. Novel pre-transplant conditioning regimens using intravenous busulfan have been investigated with promising results being obtained to date. A recent analysis of Japanese transplant registry data revealed similar survival following CBT to HLA-matched unrelated BM/PB transplants.

In vitro volatile organic compound profiling using GC×GC-TOFMS to differentiate bacteria associated with lung infections: a proof-of-concept study

Chronic pulmonary infections are the principal cause of morbidity and mortality in individuals with cystic fibrosis (CF). Due to the polymicrobial nature of these infections, the identification of the particular bacterial species responsible is an essential step in diagnosis and treatment. Current diagnostic procedures are time-consuming, and can also be expensive, invasive and unpleasant in the absence of spontaneously expectorated sputum. The development of a rapid, non-invasive methodology capable of diagnosing and monitoring early bacterial infection is desired. Future visions of real-time, in situ diagnosis via exhaled breath testing rely on the differentiation of bacteria based on their volatile metabolites. The objective of this proof-of-concept study was to investigate whether a range of CF-associated bacterial species (i.e. Pseudomonas aeruginosa, Burkholderia cenocepacia, Haemophilus influenzae, Stenotrophomonas maltophilia, Streptococcus pneumoniae and Streptococcus milleri) could be differentiated based on their in vitro volatile metabolomic profiles. Headspace samples were collected using solid phase microextraction (SPME), analyzed using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-TOFMS) and evaluated using principal component analysis (PCA) in order to assess the multivariate structure of the data. Although it was not possible to effectively differentiate all six bacteria using this method, the results revealed that the presence of a particular pattern of VOCs (rather than a single VOC biomarker) is necessary for bacterial species identification. The particular pattern of VOCs was found to be dependent upon the bacterial growth phase (e.g. logarithmic versus stationary) and sample storage conditions (e.g. short-term versus long-term storage at −18 °C). Future studies of CF-associated bacteria and exhaled breath condensate will benefit from the approaches presented in this study and further facilitate the production of diagnostic tools for the early detection of bacterial lung infections.

C7 genotype of the donor may predict early bacterial infection after liver transplantation.

Post-transplantation infection causes high mortality and remains a significant challenge. High clinical risk factors for bacterial infection in recipients are often found in critically ill patients. However, for some recipients, bacterial infections are inevitable. It is conceivable that this susceptibility may be related to the genetics of the donor and recipient. Using expression quantitative trait loci (eQTL) analysis, we found that the C7 rs6876739 CC genotypes and mannan-binding lectin (MBL2) gene polymorphisms of liver donors were significantly associated with bacterial infection in recipients. In an extended validation group of 113 patients, donor C7 rs6876739 genetic variation was an independent risk factor for bacterial infection. The donor C7 rs6876739 CC genotype was associated with lower levels of recipient C7 protein, soluble membrane attack complex (MAC), and IL-1β expression compared with the donor C7 rs6876739 TT genotype. In vitro, the MAC significantly triggered NLRP3 inflammasome activation and IL-1β release, suggesting that the mechanism by which C7 defends against bacteria may involve MAC formation, leading to NLRP3 inflammasome activation and IL-1β release. Our findings may be helpful in identifying transplantation recipients at risk of bacterial infection prior to surgery and may contribute to novel infection prevention strategies and the improvement of postoperative outcomes.

Temporal Progression of Pneumonic Plague in Blood of Nonhuman Primate: A Transcriptomic Analysis.

Early identification of impending illness during widespread exposure to a pathogenic agent offers a potential means to initiate treatment during a timeframe when it would be most likely to be effective and has the potential to identify novel therapeutic strategies. The latter could be critical, especially as antibiotic resistance is becoming widespread. In order to examine pre-symptomatic illness, African green monkeys were challenged intranasally with aerosolized Yersinia pestis strain CO92 and blood samples were collected in short intervals from 45 m till 42 h post-exposure. Presenting one of the first genomic investigations of a NHP model challenged by pneumonic plague, whole genome analysis was annotated in silico and validated by qPCR assay. Transcriptomic profiles of blood showed early perturbation with the number of differentially expressed genes increasing until 24 h. By then, Y. pestis had paralyzed the host defense, as suggested by the functional analyses. Early activation of the apoptotic networks possibly facilitated the pathogen to overwhelm the defense mechanisms, despite the activation of the pro-inflammatory mechanism, toll-like receptors and microtubules at the port-of-entry. The overexpressed transcripts encoding an early pro-inflammatory response particularly manifested in active lymphocytes and ubiquitin networks were a potential deviation from the rodent models, which needs further verification. In summary, the present study recognized a pattern of Y. pestis pathogenesis potentially more applicable to the human system. Independent validation using the complementary omics approach with comprehensive evaluation of the organs, such as lungs which showed early bacterial infection, is essential.

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation.

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

Bacterial profile of early versus late onset neonatal sepsis in a North Indian tertiary care centre: Heading towards a change

Traditional division of neonatal sepsis into early (EOS) and late onset sepsis (LOS) may be fallible. We analyzed the bacteriological profile of neonatal sepsis day wise to see if the organisms causing EOS and LOS are really different in the current era. This retrospective study was conducted in a tertiary care neonatal unit from 1995–2006. Neonates with proven sepsis were included. The exact age of the neonate when the blood culture was obtained was extracted. To identify the overlap between vertically and hospital acquired sepsis, a similar percentage contribution of a particular organism on a day wise analysis in the first 7 days of life was required. Day wise analysis was done by χ2 for trends. One thousand and four hundred and ninety-one neonates had blood culture proven sepsis (38.6 per 1000 live births). EOS was caused predominantly by Klebsiella pneumoniae and non-fermenting Gram-negative bacilli; whereas LOS was caused mainly by Staphylococcus aureus. All organisms were isolated on all the days of life. Thirty one percent developed culture proven sepsis in first 24 hours of life. Non-fermenting Gram-negative bacilli significantly contributed on day 1 while S. aureus sepsis was significantly higher from day 7 onward on trend analysis. The definition of EOS and LOS based on day of isolation alone may not be applicable. A prospective evaluation of the source of early bacterial infections is required.

Severe congenital neutropenia caused by the ELANE gene mutation in a Vietnamese boy with misdiagnosis of tuberculosis and autoimmune neutropenia: a case report.

BackgroundSevere congenital neutropenia (SCN) is an immunodeficiency disease characterized low blood neutrophil counts, early bacterial infections, and risk of leukaemia development. Heterozygous mutations in the ELANE gene coding neutrophil elastase are associated with SCN. Patients with SCN suffer from recurrent bacterial infections and often succumb them. To our knowledge, this is the first report of SCN from Vietnam.Case presentationA 6-year-old boy was admitted due to severe bacterial infection and severe neutropenia. He had recurrent infections from 8 months of age, and was misdiagnosed with tuberculosis and and autoimmune neutropenia in infancy at 21 and 41 months of age, respectively. His medical report has showed severe neutropenia for many times. In direct DNA sequencing analysis, we found an ELANE gene mutation (R81P), which had been confirmed to cause SCN.ConclusionThe missed and delayed diagnosis may be attributable to insufficient awareness of this rare disease on the background of frequent infections even in the immunocompetent pediatric population in Vietnam. Our results indicate further evidence for the role of ELANE in SCN.

The influence of statin exposure on inflammatory markers in patients with early bacterial infection: pilot prospective cohort study.

BackgroundIn the context of infection, progressive illness resulting in acute organ dysfunction is thought to be secondary to inflammatory response. Our aims were to determine risk factors for progressive illness following infection in a low-risk hospitalised cohort, including the impact of prior stain therapy.MethodsWe performed a prospective observational cohort study on two adult acute medical wards of a single tertiary academic hospital. We screened drug prescription charts of all adult acute medical admissions for inclusion criteria of inpatient administration of antibiotics for more than 24 hours for a microbiologically confirmed or clinically suspected infection. Patients were followed until admission to a high dependency unit (HDU) or intensive care unit (ICU), discharge from hospital, or to a maximum of 10 days. Outcomes were evolution of systemic inflammatory response syndrome (SIRS) criteria, white cell count and C-reactive protein measurements, and adverse clinical outcomes. We constructed multivariable models accounting for repeated within-patient measurements to determine associations between a priori selected predictors (days since admission, age, gender, Charlson score, prior statin exposure) and selected outcomes.ResultsWe enrolled 209 patients; 27.8% were statin users and the commonest infection was pneumonia (51.0%). Most (88.0%) had at least 1 SIRS criterion on admission, and 76 (37.3%) manifested additional SIRS criteria over time. Risks of admission to HDU/ICU (3.3%) and of 30-day mortality (5.7%) were low. The proportion of patients with at least 1 SIRS criterion, mean CRP, and mean WBC all decreased over time. Multivariable regression models identified days since hospital admission as the only variable associated with daily presence of SIRS criteria, WCC, or CRP (adjusted OR <1 and p < 0.0001 in all analyses). Statin exposure was not a significant predictor.ConclusionsThis cohort of ward patients treated for infection had a low risk of clinical deterioration, inflammatory markers improved over time, and statin exposure was not associated with any outcome. Future larger studies may identify risk factors for progression of illness in this population and plausible surrogate endpoints for evaluation in clinical trials.

Role of Interleukin-6 in Differentiating Interleukin-11 Induced Fever and Early Bacterial Infection

To evaluate the role of Th1/Th2 cytokines (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ) in differentiating interleukin 11 induced fever with C-reactive protein elevation from early bacterial infection. A total of 74 patients were enrolled in this retrospective study. Serum Th1/Th2 cytokines were determined using cytometric bead array (CBA) techniques. Whenever the patients had febrile disease or elevated CRP, systemic inflammatory signs, procalcitonin (PCT), blood culture and X-ray examination were done. The patients were assigned into infected and non-infected groups based on the clinical and laboratory findings. The CRP levels in both the groups were significantly increased, but no statistically significant difference was found (P = 0.574). IL-6 levels of the infected group were significantly elevated with simultaneously elevated IL-10 levels in a proportion of the patients. IL-6 levels of non-infected patients were normal. IL-6 and IL-10 levels of infected patients were significantly higher than those of non-infected patients (P = 0.005, 0.015, respectively). For the patients treated with recombinant human interleukin 11 (rhIL-11), IL-6 and IL-10 measurements can be a useful adjuvant tool for the differentiation of rhIL-11 induced fever with C-reactive protein elevation from early bacterial infection.

Impact of pretransplant rifaximin therapy on early post-liver transplant infections

Bacterial and fungal infections are major causes of morbidity and mortality after liver transplantation (LT). The role of intestinal decontamination in the prevention of post-LT infections is controversial. Rifaximin is widely used for the treatment of hepatic encephalopathy. The effect of rifaximin on post-LT infections is unknown. The aim of our study was to determine the effect of rifaximin therapy in the pretransplant period on early bacterial infections (EBIs) and fungal infections within the first 30 days after LT. All adult patients who underwent LT at our institution (January 2009 to July 2011) were included in this retrospective cohort study. Patients receiving antibiotics other than pretransplant protocol antibiotics were excluded. Patients were stratified into 2 groups based on the presence or absence of rifaximin therapy for at least 2 days before LT. Infections were defined by the isolation of any bacterial or fungal organisms within 30 days of LT. Multivariate regression analysis, Student t tests, and Pearson's chi-square tests were used to compare the 2 groups. Two hundred sixty-eight patients were included, and 71 of these patients (26.5%) were on rifaximin at the time of LT. The 2 groups were comparable with respect to age, sex, race, and Model for End-Stage Liver Disease score. There were no significant differences in the rates of EBIs (30% for the non-rifaximin group and 25% for the rifaximin group, P = 0.48) or fungal infections between the 2 groups. There was no increase in antimicrobial resistance among the infecting organisms. There was no difference in survival between the rifaximin and non-rifaximin groups (98% versus 97%, P = 0.36). In conclusion, the use of rifaximin in the pre-LT period was not associated with an increased risk of bacterial or fungal infections in the early post-LT period.

(812) - Factors Associated With Early Bacterial Infection After Lung Transplantation in Cystic Fibrosis Patients in Two French Centers With Different Antibiotic Prophylaxis Regimen

Early infection is frequent after lung transplantation (LT) in cystic fibrosis (CF). In order to identify factors associated with post-operative bacterial infection (POBI) a study was conducted in two french LT centers with different prophylaxis regimen (center 1 : narrow spectrum short prophylaxis; center 2 : wide spectrum extended prophylaxis).

Usefulness of Procalcitonin in the Diagnosis of Early Neonatal Bacterial Infection

Background: The use of several biochemical markers has improved the diagnosis of neonatal bacterial infection, which remains an important cause of morbidity and mortality. Recently, serum procalcitonin (PCT) has been investigated as a new marker for the detection of bacterial infection. The aim of t...

Risk Factors for Early Bacterial Infections in Liver Transplantation

ObjectiveOur aim was to determine perioperative risk factors for early bacterial infection after liver transplantation. MethodsRetrospectively examining medical records using Centers for Disease Control and Prevention (CDC) definitions to identify nosocomial infections, we analyzed data on 367 adult patients. ResultsThe incidence of infection was 37.3% (n = 137): namely, surgical site (n = 4; 20.2%), blood stream (n = 64; 17.4%), pulmonary (n = 49; 13.4%), urinary system (n = 26; 7.1%). Significant risk factors within the first 30 days were as follows: deceased donor, Model for End-Stage Liver Disease (MELD) >20, albumin level <2.8 g/dL, intraoperative erythrocyte transfusion >6 U, intraoperative fresh frozen plasma >12 U, bilioenteric anastomosis, postoperative intensive care unit stay >6 days, and postoperative length of stay >21 days. Significant risk factors detected within the first 90 days were as follows: MELD >20, preoperative length of stay >7 days, reoperation, postoperative length of intensive care unit stay >6 days, and postoperative length of stay >21 days. Variability was observed in risk factors according to localization of infection. As a result, except for MELD, type of donor, and biliary anastomosis, the others are preventable factors for early bacterial infection. In addition, the same risk factors showed variability according to the site of infection.

Early Bacterial Bronchopulmonary Infection after Lung Transplantation: Bacterial Epidemiology and Diagnostic Value of Clinical and Biological Parameters

<h3>Purpose</h3> Postoperative infectious complications are key issues following lung transplantation (LT). Early bacterial pneumonia (EBP) worsen prognosis of LT. Assessment of bacterial epidemiology of EBP is necessary to optimize treatment of EBP, thus improving LT outcome. <h3>Methods and Materials</h3> From 2006 to 2010, all consecutive LT performed in our institution were included. Demographic and microbiologic data during the first 30 postoperative days after LT were collected. <h3>Results</h3> 102 LT (emphysema 46%, idiopathic fibrosis 38%) were performed during the study period. Among 831 bacteriological cultures of bronchial aspirate, 307 were positive. Evolution of bacterial epidemiology during the first 2 weeks is presented in figure 1. Donor colonization was associated with recipient infection with Methicilin-sensitive Staphylococcus aureus (MSSA) (OR=5,84; [1,87-18,27], p=0,0033) and Enterobacteria (0R=2,8; [1,15-6,83], p=0,037). Presence of purulent expectoration, contrary to fever, leukocyte count, chest X ray, impairment in lung function and CPIS scor, was associated with positive bacterial cultures (OR=1,99; IC [1,45-2,72] p=0,01). Interestingly, type of bacteria did not have any impact on mortality at day 30. <h3>Conclusions</h3> There is an evolution of bronchial bacterial epidemiology during the 2 weeks following LT with an increase in Pseudomonas aeruginosa proportion. Only purulent expectoration, but not other parameters currently used to diagnose post operative pneumonia, is associated with positive bacterial culture of bronchial aspiration. These findings highlight the challenging problems raised by the diagnosis of respiratory infection after LT.

Bacteremia in Blood or Marrow Transplantation Patients: Clinical Risk Factors for Infection and Emerging Antibiotic Resistance

Bacterial infections continue to be a leading cause of mortality and morbidity in patients who undergo blood and marrow transplantations (BMTs). The relative importance of different clinical features (donor type, graft cell source, and conditioning regimen) on the incidence and timing of posttransplantation bacterial infections is uncertain, but a detailed analysis could better guide prevention and therapy. We retrospectively analyzed the incidence and risk factors for early bacterial infections, as well as patterns of antibiotic resistance. We observed 613 bacteremic events among 349 of 834 patients who underwent BMT treated at the University of Minnesota from 2005 to 2010 (cumulative incidence 42%; 95% confidence interval [CI], 38-45). Donor type (allogeneic vs autologous) had the greatest impact on the incidence of bacteremia within 100 days posttransplantation. Among allogeneic transplantations, myeloablative (MA), compared to reduced-intensity conditioning (RIC) was associated with a significantly greater risk of bacteremia, as was the development of acute graft-versus-host disease (aGVHD). Additionally, patients who underwent BMT, compared to the contemporaneous hospital population, developed infections with more frequent resistance to antibiotics used in the treatment against commonly isolated bacterial organisms. These findings have important clinical implications regarding the use and selection of both prophylactic and empiric antibiotic regimens.

Incidence of severe congenital neutropenia in Sweden and risk of evolution to myelodysplastic syndrome/leukaemia

Severe congenital neutropenia (SCN) is characterized by low blood neutrophil counts, early bacterial infections, and risk of leukaemia development. As yet, no population-based incidence estimates of SCN have been reported. Children less than 16 years of age with SCN were sought in Sweden during the 20-year period 1987-2006 by a questionnaire to all Swedish Departments of Paediatrics and by reviewing the Swedish Health and Welfare Statistical Databases. Thirty-two patients were diagnosed with congenital neutropenia during this period. All received treatment with recombinant granulocyte-colony stimulating factor (G-CSF). Twenty-one patients were diagnosed as SCN or probable SCN, corresponding to 1·0 per 100,000 live births. Nine (43%) had ELANE mutations, four (19%) HAX1 mutations and eight (38%) were children with disease of unknown genetic aetiology. Four out of 21 patients (19%) developed myelodysplastic syndrome/leukaemia and three (14%) died, all with leukaemia. The cumulative incidence of myelodysplastic syndrome/leukaemia was 31%. The observed incidence of SCN in this population-based study was higher than previously estimated, possibly because genetic testing now can identify SCN cases previously thought to be idiopathic or benign neutropenia. The risk of developing myelodysplastic syndrome/leukaemia is considerable. ELANE mutations are the most commonly identified genetic defects.

Fluoroquinolones are not a blanket cover for gram-negative bacilli

We read with interest the Spanish report on selective intestinal decontamination with fluoroquinolones for the prevention of early bacterial infections after liver transplantation. Although the study was not randomized, the investigators made a significant contribution through their finding of ‘‘a higher relative incidence of infections by NFGNBs [nonfermenting gram-negative bacilli] in patients undergoing FQ-SID [fluoroquinolone selective intestinal decontamination], which probably overrode the protective effect against infections due to enteric bacteria.’’ Their conclusion that other selective intestinal decontamination strategies should be evaluated in this high-risk population is valid. The observations of this Spanish study confirm findings from earlier randomized controlled trials of critically ill patients requiring treatment in the intensive care unit and receiving fluoroquinolones. Belgian and Austrian randomized controlled trials have demonstrated that the classical selective intestinal decontamination regimen of polymyxin and tobramycin does cover nonfermenting gram-negative bacilli (apart from Enterobacteriaceae). The partial efficacy of selective intestinal decontamination with fluoroquinolones can be explained by the observation that fluoroquinolones eradicate gut overgrowth of Enterobacteriaceae after intestinal excretion via the gut mucosa but not the overgrowth of nonfermenting gram-negative bacilli, which is subsequently followed by polyclonality and resistance. In contrast, polymyxin and tobramycin have consistently been shown to achieve the successful eradication of overgrowth of gram-negative bacilli (both fermenting and nonfermenting); that is, surveillance cultures are persistently negative for these potential pathogens. We would like to contribute to the discussion by suggesting the assessment of the selective intestinal decontamination strategy of polymyxin and tobramycin rather than probiotics. Luciano Silvestri, M.D. Miguel A. de la Cal, M.D. Durk F. Zandstra, M.D. Nia Taylor, M.Phil. Hendrick K. F. van Saene, M.D., Ph.D. Anesthesia and Intensive Care Unit Emergency Department Presidio Ospedaliero Gorizia, Italy Intensive Care Unit University Hospital of Getafe Getafe, Spain Intensive Care Unit Onze Lieve Vrouwe Gasthuis Amsterdam, the Netherlands Institute of Ageing and Chronic Disease University of Liverpool Liverpool, United Kingdom