Epidemiology and Outcome of Fungemia in a Cancer Cohort of the Infectious Diseases Group (IDG) of the European Organization for Research and Treatment of Cancer (EORTC 65031)

In a prospective cohort study of 145 030 admissions of cancer patients from 13 European Organisation for Research and Treatment of Cancer centers fungemia occurred in 0.23%. Candida albicans was the predominant pathogen. Fungemia was associated with substantial mortality. Antifungal prophylaxis and remission of cancer predicted better surviva

A Randomized, Placebo-controlled Trial of Preemptive Antifungal Therapy for the Prevention of Invasive Candidiasis Following Gastrointestinal Surgery for Intra-abdominal Infections.

BACKGROUND: Patients undergoing emergency gastrointestinal surgery for intra-abdominal infection are at risk of invasive candidiasis (IC) and candidates for preemptive antifungal therapy. METHODS: This exploratory, randomized, double-blind, placebo-controlled trial assessed a preemptive antifungal approach with micafungin (100 mg/d) in intensive care unit patients requiring surgery for intra-abdominal infection. Coprimary efficacy variables were the incidence of IC and the time from baseline to first IC in the full analysis set; an independent data review board confirmed IC. An exploratory biomarker analysis was performed using logistic regression. RESULTS: The full analysis set comprised 124 placebo- and 117 micafungin-treated patients. The incidence of IC was 8.9% for placebo and 11.1% for micafungin (difference, 2.24%; [95% confidence interval, -5.52 to 10.20]). There was no difference between the arms in median time to IC. The estimated odds ratio showed that patients with a positive (1,3)-β-d-glucan (ßDG) result were 3.66 (95% confidence interval, 1.01-13.29) times more likely to have confirmed IC than those with a negative result. CONCLUSIONS: This study was unable to provide evidence that preemptive administration of an echinocandin was effective in preventing IC in high-risk surgical intensive care unit patients with intra-abdominal infections. This may have been because the drug was administered too late to prevent IC coupled with an overall low number of IC events. It does provide some support for using ßDG to identify patients at high risk of IC. CLINICAL TRIALS REGISTRATION: NCT01122368

In vitro susceptibility of Clostridium difficile to SMT19969 and comparators, as well as the killing kinetics and post-antibiotic effects of SMT19969 and comparators against C. difficile

© The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/ 4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.OBJECTIVES: SMT19969 is a novel antimicrobial under clinical development for the treatment of Clostridium difficile infection (CDI). The objective was to determine the comparative susceptibility of 82 C. difficile clinical isolates (which included ribotype 027 isolates and isolates with reduced metronidazole susceptibility) to SMT19969, fidaxomicin, vancomycin and metronidazole and to determine the killing kinetics and post-antibiotic effects of SMT19969, fidaxomicin and vancomycin against C. difficile. METHODS: MICs were determined by agar incorporation. Killing kinetics and post-antibiotic effects were determined against C. difficile BI1, 630 and 5325 (ribotypes 027, 012 and 078, respectively). RESULTS: SMT19969 showed potent inhibition of C. difficile (MIC90=0.125 mg/L) and was markedly more active than either metronidazole (MIC90 = 8 mg/L) or vancomycin (MIC90 = 2 mg/L). There were no differences in susceptibility to SMT19969 between different ribotypes. Fidaxomicin was typically one doubling dilution more active than SMT19969 and both agents maintained activity against isolates with reduced susceptibility to metronidazole. In addition, SMT19969 was bactericidal against the C. difficile strains tested, with reductions in viable counts to below the limit of detection by 24 h post-inoculation. Vancomycin was bacteriostatic against all three strains. Fidaxomicin was bactericidal although reduced killing was observed at concentrations <20 × MIC against C. difficile BI1 (ribotype 027) compared with other strains tested. CONCLUSIONS: These data demonstrate that SMT19969 is associated with potent and bactericidal activity against the strains tested and support further investigation of SMT19969 as potential therapy for CDI.Peer reviewedFinal Published versio

Cluster M Mycobacteriophages Bongo, PegLeg, and Rey with Unusually Large Repertoires of tRNA Isotopes

Genomic analysis of a large set of phages infecting the common hostMycobacterium smegmatis mc2155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2. The cluster M mycobacteriophages have siphoviral morphologies with unusually long tails, are homoimmune, and have larger than average genomes (80.2 to 83.7 kbp). They exhibit a variety of features not previously described in other mycobacteriophages, including noncanonical genome architectures and several unusual sets of conserved repeated sequences suggesting novel regulatory systems for both transcription and translation. In addition to containing transfer-messenger RNA and RtcB-like RNA ligase genes, their genomes encode 21 to 24 tRNA genes encompassing complete or nearly complete sets of isotypes. We predict that these tRNAs are used in late lytic growth, likely compensating for the degradation or inadequacy of host tRNAs. They may represent a complete set of tRNAs necessary for late lytic growth, especially when taken together with the apparent lack of codons in the same late genes that correspond to tRNAs that the genomes of the phages do not obviously encode

Epidemiology of invasive candidiasis in a surgical intensive care unit: an observational study

Background: Invasive candidiasis (IC) is a frequent and life-threatening infection in critically ill patients. The aim of this study was to evaluate the epidemiology of IC and the antifungal susceptibility of etiological agents in patients admitted to our surgical intensive care unit (SICU) in Spain. Methods: We designed a prospective, observational, single center, population-based study in a SICU. We included all consecutive adult patients (≥18 years old) who had documented IC, either on admission or during their stay, between January 2012 and December 2013. Results: There were a total of 22 episodes of IC in the 1149 patients admitted during the 24-month study. The overall IC incidence was 19.1 cases per 1000 admissions. Thirteen cases of IC (59.1 %) were intra-abdominal candidiasis (IAC) and 9 (40.9 %) were candidemias. All cases of IAC were patients with secondary peritonitis and severe sepsis or septic shock. The overall crude mortality rate was 13.6 %; while, it was 33 % in patients with candidemia. All patients with IAC survived, including one patient with concomitant candidemia. The most common species causing IC was Candida albicans (13; 59.1 %) followed by Candida parapsilosis (5; 22.7 %), and Candida glabrata (2; 9.1 %). There was also one case each (4.5 %) of Candida krusei and Candida tropicalis. Thus, the ratio of non-C. albicans (9) to C. albicans (13) was 1:1.4. There was resistance to fluconazole and itraconazole in 13.6 % of cases. Resistance to other antifungals was uncommon. Conclusions: Candida parapsilosis was the second most common species after C. albicans, indicating the high prevalence of non-C. albicans species in the SICU. Resistance to azoles, particularly fluconazole, should be considered when starting an empirical treatment. Although IAC is a very frequent form of IC in critically ill surgical patients, prompt antifungal therapy and adequate source control appears to lead to a good outcome. However, our results are closely related to our ICU and any generalization must be taken with caution. Therefore, further investigations are needed. Keywords: Intensive care unit, Invasive candidiasis, Candidemia, Antifungal susceptibilit

The impact of the introduction of fidaxomicin on the management of Clostridium difficile infection in seven NHS secondary care hospitals in England: a series of local service evaluations.

Clostridium difficile infection (CDI) is associated with high mortality. Reducing incidence is a priority for patients, clinicians, the National Health Service (NHS) and Public Health England alike. In June 2012, fidaxomicin (FDX) was launched for the treatment of adults with CDI. The objective of this evaluation was to collect robust real-world data to understand the effectiveness of FDX in routine practice. In seven hospitals introducing FDX between July 2012 and July 2013, data were collected retrospectively from medical records on CDI episodes occurring 12 months before/after the introduction of FDX. All hospitalised patients aged ≥18 years with primary CDI (diarrhoea with presence of toxin A/B without a previous CDI in the previous 3 months) were included. Recurrence was defined as in-patient diarrhoea re-emergence requiring treatment any time within 3 months after the first episode. Each hospital had a different protocol for the use of FDX. In hospitals A and B, where FDX was used first line for all primary and recurrent episodes, the recurrence rate reduced from 10.6 % to 3.1 % and from 16.3 % to 3.1 %, with a significant difference in 28-day mortality from 18.2 % to 3.1 % (p < 0.05) and 17.3 % to 6.3 % (p < 0.05) for hospitals A and B, respectively. In hospitals using FDX in selected patients only, the changes in recurrence rates and mortality were less marked. The pattern of adoption of FDX appears to affect its impact on CDI outcome, with maximum reduction in recurrence and all-cause mortality where it is used as first-line treatment

Novel highly potent CD4bs bNAb with restricted pathway to HIV-1 escape

Purpose: Broadly HIV-1 neutralizing antibodies (bNAbs) can suppress viremia in humans and represent a novel approach for effective immunotherapy. However, bNAb monotherapy selects for antibody-resistant viral variants. Thus, we focused on the identification of new antibody combinations and/or novel bNAbs that restrict pathways of HIV-1 escape. Methods: We screened HIV-1 positive patients for their neutralizing capacities. Following, we performed single cell sorting and PCR of HIV-1 Env-reactive mature B cells of identified elite neutralizers. Found antibodies were tested for neutralization and binding capacities in vitro. Further, their antiviral activity was tested in an HIV-1 infected humanized mouse model. Results: Here we report the isolation of antibody 1–18, a VH1–46-encoded CD4 binding site (CD4bs) bNAb identified in an individual ranking among the top 1% neutralizers of 2,274 HIV-1-infected subjects. Tested on a 119-virus panel, 1–18 showed to be exceptionally broad and potent with a coverage of 97% and a mean IC50 of 0.048 lg/mL, exceeding the activity of most potent CD4bs bNAbs described to-date. A 2.4 Å cryo-EM structure of 1–18 bound to a native-like Env trimer revealed that it interacts with HIV-1 env similar to other CD4bs bNAbs, but includes additional contacts to the V3 loop of the adjacent protomer. Notably, in vitro, 1–18 maintained activity against viruses carrying mutations associated with escape from VRC01-class bNAbs. Further, its HIV-1 env wide escape profile differed critically from other CD4bs bNAbs. In humanized mice, monotherapy with 1–18 was sufficient to prevent the development of viral escape variants that rapidly emerged during treatment with other CD4bs bNAbs. Finally, 1–18 overcame classical HIV-1 mutations that are driven by VRC01-like bNAbs in vivo. Conclusion: 1–18 is a highly potent and broad bNAb that restricts escape and overcomes frequent CD4bs escape pathways, providing new options for bNAb combinations to prevent and treat HIV-1 infection

On the isoperimetric problem for the Laplacian with Robin and Wentzell boundary conditions

Doctor of PhilosophyWe consider the problem of minimising the eigenvalues of the Laplacian with Robin boundary conditions $\frac{\partial u}{\partial \nu} + \alpha u = 0$ and generalised Wentzell boundary conditions $\Delta u + \beta \frac{\partial u}{\partial \nu} + \gamma u = 0$ with respect to the domain $\Omega \subset \mathbb R^N$ on which the problem is defined. For the Robin problem, when $\alpha > 0$ we extend the Faber-Krahn inequality of Daners [Math. Ann. 335 (2006), 767--785], which states that the ball minimises the first eigenvalue, to prove that the minimiser is unique amongst domains of class $C^2$. The method of proof uses a functional of the level sets to estimate the first eigenvalue from below, together with a rearrangement of the ball's eigenfunction onto the domain $\Omega$ and the usual isoperimetric inequality. We then prove that the second eigenvalue attains its minimum only on the disjoint union of two equal balls, and set the proof up so it works for the Robin $p$-Laplacian. For the higher eigenvalues, we show that it is in general impossible for a minimiser to exist independently of $\alpha > 0$. When $\alpha < 0$, we prove that every eigenvalue behaves like $-\alpha^2$ as $\alpha \to -\infty$, provided only that $\Omega$ is bounded with $C^1$ boundary. This generalises a result of Lou and Zhu [Pacific J. Math. 214 (2004), 323--334] for the first eigenvalue. For the Wentzell problem, we (re-)prove general operator properties, including for the less-studied case $\beta 0$ establish a type of equivalence property between the Wentzell and Robin minimisers for all eigenvalues. This yields a minimiser of the second Wentzell eigenvalue. We also prove a Cheeger-type inequality for the first eigenvalue in this case

An adolescent with both Wegener's Granulomatosis and chronic blastomycosis

We report a case of Wegener's Granulomatosis (WG) associated with blastomycosis. This appears to be the first case report of WG co-existing with a tissue proven blastomycosis infection. The temporal correlation of the two conditions suggests that blastomycosis infection (and therefore possibly other fungal infections), may trigger the systemic granulomatous vasculitis in a predisposed individual; a provocative supposition warranting further study