Spatially resolved analysis of Pseudomonas aeruginosa biofilm proteomes measured by laser ablation sample transfer.

Heterogeneity in the distribution of nutrients and oxygen gradients during biofilm growth gives rise to changes in phenotype. There has been long term interest in identifying spatial differences during biofilm development including clues that identify chemical heterogeneity. Laser ablation sample transfer (LAST) allows site-specific sampling combined with label free proteomics to distinguish radially and axially resolved proteomes for Pseudomonas aeruginosa biofilms. Specifically, differential protein abundances on oxic vs. anoxic regions of a biofilm were observed by combining LAST with bottom up proteomics. This study reveals a more active metabolism in the anoxic region of the biofilm with respect to the oxic region for this clinical strain of P. aeruginosa, despite this organism being considered an aerobe by nature. Protein abundance data related to cellular acclimations to chemical gradients include identification of glucose catabolizing proteins, high abundance of proteins from arginine and polyamine metabolism, and proteins that could also support virulence and environmental stress mediation in the anoxic region. Finally, the LAST methodology requires only a few mm2 of biofilm area to identify hundreds of proteins.

Reverse diauxie phenotype in Pseudomonas aeruginosa biofilm revealed by exometabolomics and label-free proteomics.

Microorganisms enhance fitness by prioritizing catabolism of available carbon sources using a process known as carbon catabolite repression (CCR). Planktonically grown Pseudomonas aeruginosa is known to prioritize the consumption of organic acids including lactic acid over catabolism of glucose using a CCR strategy termed "reverse diauxie." P. aeruginosa is an opportunistic pathogen with well-documented biofilm phenotypes that are distinct from its planktonic phenotypes. Reverse diauxie has been described in planktonic cultures, but it has not been documented explicitly in P. aeruginosa biofilms. Here a combination of exometabolomics and label-free proteomics was used to analyze planktonic and biofilm phenotypes for reverse diauxie. P. aeruginosa biofilm cultures preferentially consumed lactic acid over glucose, and in addition, the cultures catabolized the substrates completely and did not exhibit the acetate secreting "overflow" metabolism that is typical of many model microorganisms. The biofilm phenotype was enabled by changes in protein abundances, including lactate dehydrogenase, fumarate hydratase, GTP cyclohydrolase, L-ornithine N(5)-monooxygenase, and superoxide dismutase. These results are noteworthy because reverse diauxie-mediated catabolism of organic acids necessitates a terminal electron acceptor like O2, which is typically in low supply in biofilms due to diffusion limitation. Label-free proteomics identified dozens of proteins associated with biofilm formation including 16 that have not been previously reported, highlighting both the advantages of the methodology utilized here and the complexity of the proteomic adaptation for P. aeruginosa biofilms. Documenting the reverse diauxic phenotype in P. aeruginosa biofilms is foundational for understanding cellular nutrient and energy fluxes, which ultimately control growth and virulence.

Laser Desorption Combined with Laser Postionization for Mass Spectrometry.

Lasers with pulse lengths from nanoseconds to femtoseconds and wavelengths from the mid-infrared to extreme ultraviolet (UV) have been used for desorption or ablation in mass spectrometry. Such laser sampling can often benefit from the addition of a second laser for postionization of neutrals. The advantages offered by laser postionization include the ability to forego matrix application, high lateral resolution, decoupling of ionization from desorption, improved analysis of electrically insulating samples, and potential for high sensitivity and depth profiling while minimizing differential detection. A description of postionization by vacuum UV radiation is followed by a consideration of multiphoton, short pulse, and other postionization strategies. The impacts of laser pulse length and wavelength are considered for laser desorption or laser ablation at low pressures. Atomic and molecular analysis via direct laser desorption/ionization using near-infrared ultrashort pulses is described. Finally, the postionization of clusters, the role of gaseous collisions, sampling at ambient pressure, atmospheric pressure photoionization, and the addition of UV postionization to MALDI are considered.

Contribution of brain imaging to the diagnosis of intracranial tuberculoma and other brain lesions in patients presenting with miliary tuberculosis.

BACKGROUND: Miliary tuberculosis (miliary TB) is characterized by a hematogenous spread of Mycobacterium tuberculosis. Cerebral lesions associated with miliary TB have been reported with diverse frequencies. METHODS: We retrospectively analyzed brain imaging in 34 patients presenting with proven miliary TB hospitalized in our teaching hospital between 2008 and 2014. RESULTS: Neurological symptoms were present at admission in 15 patients, emerged during treatment in six, and were never reported in 13. Twenty-one of 34 patients had cerebral involvement, of which five patients did not present with any neurological symptoms. The most common brain lesions on MRI were tuberculomas. Cerebrospinal fluid (CSF) analysis showed elevated cell count in eight patients who all had abnormal MRI results. Nine patients with normal CSF had abnormal MRI results. CSF cultures were positive in only eight patients. Paradoxical clinical worsening during TB and corticosteroid treatment was observed in six patients. CONCLUSION: Among patients presenting with miliary TB who underwent brain imaging, more than 60% demonstrated cerebral involvement. Abnormal imaging could occur without any clinical nor CSF impairment. Systematically performing brain imaging in miliary TB patients could therefore be informative.

Solid Sampling with a Diode Laser for Portable Ambient Mass Spectrometry.

A hand-held diode laser is implemented for solid sampling in portable ambient mass spectrometry (MS). Specifically, a pseudocontinuous wave battery-powered surgical laser diode is employed for portable laser diode thermal desorption (LDTD) at 940 nm and compared with nanosecond pulsed laser ablation at 2940 nm. Postionization is achieved in both cases using atmospheric pressure photoionization (APPI). The laser ablation atmospheric pressure photoionization (LAAPPI) and LDTD-APPI mass spectra of sage leaves (Salvia officinalis) using a field-deployable quadrupole ion trap MS display many similar ion peaks, as do the mass spectra of membrane grown biofilms of Pseudomonas aeruginosa. These results indicate that LDTD-APPI method should be useful for in-field sampling of plant and microbial communities, for example, by portable ambient MS. The feasibility of many portable MS applications is facilitated by the availability of relatively low cost, portable, battery-powered diode lasers. LDTD could also be coupled with plasma- or electrospray-based ionization for the analysis of a variety of solid samples.

Determinants of macroscopic anal cancer and precancerous lesions in 1206 HIV-infected screened patients.

AIM: Anal screening is recommended in HIV-positive patients, especially men who have sex with men (MSM), due to an increased incidence of anal cancer. The optimal screening methods are not generally agreed. METHOD: Screening for anal lesions by anorectal examination, including anoscopy, was offered to HIV-positive outpatients in a tertiary care university hospital regardless of gender or sexual orientation. RESULTS: Among the 1206 screened patients (701 MSM, 247 heterosexual men, 258 women), 311 (26%) had histologically proven lesions related to human papilloma virus (HPV) (34% MSM, 14% heterosexual men, 14% women); 123 (10%) had low-grade dysplasia and 70 (6%) high-grade dysplasia. Seven anal cancers were also diagnosed. Determinants of any lesion were age < 45 years [OR = 1.56 (95% CI, 1.16-2.11)], a CD4 count of < 200/mm3 [OR = 2.54 (1.71-3.78)], receptive anal intercourse [OR =3.03 (2.06-4.47)], sub-Saharan African origin [OR = 0.53 (0.33-0.85)], and history of HPV-related lesion [OR = 1.84 (1.35-2.51)]. These determinants were similar for all different grades of dysplasia. In patient subgroup analysis, receptive anal intercourse, the CD4 cell count and a history of HPV lesions were determinants of HPV-positivity in all patients, whereas age was only a determinant in men. CONCLUSION: Anoscopy is an alternative method for anal screening in an HIV-positive population. This screening has to be compared with other tools in populations at high risk of anal cancer.

Complications following intravesical bacillus Calmette-Guerin treatment for bladder cancer: a case series of 22 patients.

BACKGROUND: Intravesical bacillus Calmette-Guerin (BCG) therapy is an effective and widely used treatment for superficial bladder carcinoma. Local complications are frequent whereas systemic complications are rare but can be serious, and their management is not well known. METHODS: We describe retrospectively the records of 22 patients treated in 3 infectious disease departments, for complications related to intravesical BCG therapy as treatment of bladder cancer. RESULTS: All the patients were male, with a median age of 68 years (range 56-88). Complications occurred after a median of 5 instillations (range 1-11) and were observed within 24 h following BCG instillation for 14 patients. Common symptoms were fever (n = 20), impaired general condition (n = 14), and shortness of breath (n = 7). Six patients had a systemic septic reaction leading to transfer into the intensive care unit for five of them. Lung infiltration was the most frequent presentation (n = 11). Mycobacterium bovis was isolated from only two patients, but histology showed the presence of a granuloma in nine patients. Antimycobacterial treatment was initialized in 17 patients; the outcome was favorable in 16 patients, with a median length of symptoms resolution of 22.5 days (range 5-425 days). Eleven patients received corticosteroids in addition to specific treatment and had a more rapid improvement. One patient died with disseminated BCGitis proved by biopsy. CONCLUSIONS: Complications following intravesical BCG therapy are rare but can be severe and fatal. Histology seems to be the method that contributes most in confirmation of the diagnosis. Antimycobacterial therapy is effective, and probably more efficient when combined with corticosteroids, but the regimen and duration of the treatment are not standardized.

[An update on measles]. / Actualité de la rougeole.

Measles is a highly contagious infectious disease, which needs more than 95% worldwide vaccination coverage of 2 doses to be eradicated. Despite an important involvement of the WHO for massive immunization, goals have not bean reached, and outbreaks can occur at any time in many countries, including Western Europe. In France, 22,000 cases were identified between 2009 and 2011, mainly in infants and young adults, which are not or not enough vaccinated (one dose). In 2012, even though the number of cases has drastically decreased, the outbreak is still going on, especially in South of France. That is why every clinician needs to be concerned about the clinical manifestations of the disease, and its complications. Besides a febrile rash, measles is often responsible of pneumonia and biologic hepatitis in adults. Hepatitis does not seem frequent in children. Clinicians need to be aware of specific complications, like encephalitis in case of cellular immunodepression, high risk of pneumonia in pregnant women. In patients previously vaccinated, incidence of complications is the same but patients are not contagious. Even if measles diagnosis is clinical, blood confirmation by serology is recommended in France when possible. Outcome is mainly favourable, but measles is not well-tolerated with high levels of hospitalisation even without any complication. Vaccination is the only way to protect against it.

French 2010-2011 measles outbreak in adults: report from a Parisian teaching hospital.

We reviewed 80 adult cases of measles seen in a Parisian hospital during the French 2010-2011 outbreak. Fifty per cent had at least one complication: pneumonia and hepatitis were the most frequent. Forty per cent of hospitalized cases did not have any complications, suggesting clinically poor tolerance of measles in adults. The outcome was always favourable. Subjects were younger, were more often French nationals and had a higher socio-economic status than the overall population. This report suggests that immunity resulting from natural disease in patients from an area where the disease is endemic is protective in the long term.

Resistance profiles of emtricitabine and lamivudine in tenofovir-containing regimens.

OBJECTIVES: To compare the frequency of the selection of the M184V/I resistance mutation in HIV-infected patients who experienced virological failure while receiving emtricitabine (FTC) or lamivudine (3TC), administered with tenofovir disoproxil fumarate (TDF) and either efavirenz (EFV) or a ritonavir-boosted protease inhibitor (PI; lopinavir or atazanavir). METHODS: Patient data held at two clinical centres in France were analysed retrospectively. Eligible patients had experienced virological suppression (plasma HIV RNA <200 copies/mL) for ≥ 6 months before experiencing their first virological failure (at least two measurements of plasma HIV RNA ≥ 200 copies/mL). RESULTS: Of the 880 patients eligible for the study, 278 patients had experienced virological failure while receiving FTC + TDF + ritonavir-boosted PI, 257 while receiving FTC + TDF + EFV, 178 while receiving 3TC + TDF + EFV and 167 while receiving 3TC + TDF + ritonavir-boosted PI. Proportions of patients harbouring the M184V/I mutation were 24% (n = 62) for those who received FTC + TDF + EFV versus 51% (n = 91) for 3TC + TDF + EFV (P < 0.0001; Fisher's exact test); proportions were 11% (n = 30) for FTC + TDF + ritonavir-boosted PI versus 22% (n = 37) for 3TC + TDF + ritonavir-boosted PI (P = 0.002; Fisher's exact test). The use of lamivudine versus emtricitabine (P = 0.001), non-nucleoside reverse transcriptase inhibitors versus ritonavir-boosted PIs (P = 0.01) and the level of viral load at the time of virological failure (P = 0.01) were associated with selection of the M184V/I mutation (logistic regression analysis). CONCLUSIONS: Emtricitabine and lamivudine showed differing resistance profiles when administered in combination with tenofovir disproxil fumarate and either efavirenz or a ritonavir-boosted PI. The prevalence of the M184V/I resistance mutation was significantly lower in patients who received emtricitabine and tenofovir disoproxil fumarate than in those who received lamivudine and tenofovir disoproxil fumarate.

Suitability of initial antibiotic therapy for the treatment of bloodstream infections and the potential role of antibiotic management teams in improving it.

Hospital antibiotic management teams (AMTs) have been recommended, but, in France, their concrete implementation remains scarce and their effectiveness largely unevaluated. The objective of this investigation was to evaluate the appropriateness of antibiotic therapy (AT) for bloodstream infections (BSIs) at a 950-bed university teaching hospital, and assess the role of an AMT in improving it. A prospective analysis of all significant BSIs occurring outside of the intensive care unit (ICU) during an 18-month period was carried out. AT was deemed effective if at least one prescribed antibiotic was effective in vitro, and appropriate if it was consistent with local recommendations. Out of 574 BSIs, 512 were evaluated: 231 community-acquired, 206 nosocomial, and 75 healthcare-associated. For 219 (42.8%) BSIs, the AT initiated prior to AMT intervention proved to be effective and appropriate, inappropriate but effective in 136 (26.5%), and ineffective or absent in 157 (30.7%). In the multivariate analysis, hospital-acquired and other healthcare-associated BSIs, as well as catheter-borne (CB) infections, were associated with inappropriate or absent AT. A recommendation from the AMT was given and followed in 233 (94%) out of 249 BSIs requiring intervention. Initially, two-thirds of BSIs outside the ICU did not receive appropriate AT. Healthcare-associated BSIs should, therefore, be the priority target of AMTs.

Hyperlactataemia in HIV-infected subjects initiating antiretroviral therapy in a large randomized study (a substudy of the INITIO trial).

OBJECTIVE: The aim of the study was to evaluate the predictive value of clinical and molecular risk factors, including peripheral blood mononuclear cell (PBMC) mitochondrial DNA (mtDNA) and mitochondrial RNA (mtRNA), for the development of lactic acidosis (LA) and symptomatic hyperlactataemia (SHL). METHODS: In a substudy of a large multicentre, randomized trial of three antiretroviral regimens, all containing didanosine (ddI) and stavudine (d4T), in antiretroviralnaïve, HIV-1-infected patients, patients with LA/SHL ('cases') were compared with those without LA/SHL in a univariate analysis, with significant parameters analysed in a multivariate model. In a molecular substudy, PBMC mtDNA and mtRNA from cases and matched controls at baseline and time of event were examined. RESULTS: In 911 subjects followed for a median of 192 weeks, 24 cases were identified (14 SHL and 10 LA). In univariate analysis, cases were more likely to be female (P=0.05) and to have a high body mass index (BMI) (P=0.02). In multivariate analyses, only BMI remained an independent predictor of the development of LA/SHL (P=0.03). Between cases and controls there was no significant difference in mtDNA copy number at baseline (389 vs. 411 copies/cell, respectively; P=0.60) or at time of event (329 vs. 474 copies/cell, respectively; P=0.21), in the change in mtDNA copy number from baseline to event (-65 vs. +113 copies/cell, respectively; P=0.12), in mtRNA expression at baseline or time of event, or in the change in mtRNA expression from baseline to event. CONCLUSION: The development of LA/SHL was associated with increased BMI, but PBMC mtDNA and mtRNA did not predict LA/SHL. This demonstrates the ineffectiveness of routine measurement of PBMC mtDNA in patients on ddI and d4T as a means of predicting development of LA/SHL.

[Evaluation of initial antibiotic therapy for bacteremia and role of an antibiotic management team for antibiotic stewardship]. / Évaluation de l'antibiothérapie des bactériémies et place d'une équipe mobile pour l'amélioration de la prescription antibiotique.

INTRODUCTION: Antibiotic management teams (AMTs) are recommended, but they are rarely implemented in France and their activity seldom evaluated. OBJECTIVE: The study was made to evaluate the appropriateness of antibiotic therapy (AT) for bloodstream infections (BSI) and to assess the role of an AMT for improving AT in a 950-bed teaching hospital. METHODS: A prospective analysis was made of all significant BSIs outside ICU in 2008. AT was assessed by the AMT and change was suggested if deemed necessary: effective if at least one prescribed antibiotic was effective in vitro, and appropriate if consistent with local recommendations. RESULTS: Of 875 +BCs, 560 were significant, 383 were outside ICU and 344 could be evaluated (170 community-acquired, 124 nosocomial, and 50 healthcare-associated [HCA]). The clinical ward has already initiated an effective and appropriate AT in 128 (37%), inappropriate but effective in 104 (30%), and ineffective or absent in 112 (33%) BSIs. The only independent variable associated with ineffective/absent AT was nosocomial and/or HCA BSI (aOR: 2.71; 95%CI: 1.72-4.27; p<0.001). A recommendation was given and followed in 177/190 (93%) BSIs requiring an intervention. The AMT intervened on the day of the +BC in 256 (84%) cases, the day before the +BC in 12 (4%) cases, and one day later or more in 37 (12%) BSI cases. CONCLUSION: Two third of BSIs were not initially treated by appropriate AT, more often in nosocomial BSI. Recommendation provided by the AMT was followed in 93% of cases.

Gag mutations can impact virological response to dual-boosted protease inhibitor combinations in antiretroviral-naïve HIV-infected patients.

ANRS 127 was a randomized pilot trial involving naïve patients receiving two dual-boosted protease inhibitor (PI) combinations. Virological response, defined as a plasma HIV RNA level of <50 copies/ml at week 16, occurred in only 41% patients. Low baseline plasma HIV RNA level was the only significant predictor of virological response. The purpose of this study was to investigate the impact on virological response of pretherapy mutations in cleavage sites of gag, gag-pol, and the gag-pol frameshift region. The whole gag gene and protease-coding region were amplified and sequenced at baseline and at week 16 for 48 patients still on the allocated regimen at week 16. No major PI resistance-associated mutations were detected either at baseline or in the 26 patients who did not achieve virological response at week 16. Baseline cleavage site substitutions in the product of the gag open reading frame at positions 128 (p17/p24) (P = 0.04) and 449 (p1/p6(gag)) (P = 0.01) were significantly more frequent in those patients not achieving virological response. Conversely, baseline cleavage site mutation at position 437 (TFP/p6(pol)) was associated with virological response (P = 0.04). In multivariate analysis adjusted for baseline viral load, these 3 substitutions remained independently associated with virological response. We demonstrated here, in vivo, an impact of baseline polymorphic gag mutations on virological response in naïve patients receiving a combination of two protease inhibitors. However, it was not possible to link the substitutions selected under PI selective pressure with virological failure.

Antiviral activity and safety of aplaviroc, a CCR5 antagonist, in combination with lopinavir/ritonavir in HIV-infected, therapy-naïve patients: results of the EPIC study (CCR100136).

BACKGROUND: This phase IIb study explored the antiviral activity and safety of the investigational CC chemokine receptor 5 (CCR5) antagonist aplaviroc (APL) in antiretroviral-naïve patients harbouring R5- or R5X4-tropic virus. METHODS: A total of 191 patients were randomized 2:2:2:1 to one of three APL dosing regimens or to lamivudine (3TC)/zidovudine (ZDV) twice daily (bid), each in combination with lopinavir/ritonavir (LPV/r) 400 mg/100 mg bid. Efficacy, safety and pharmacokinetic parameters were assessed. RESULTS: This study was terminated prematurely because of APL-associated idiosyncratic hepatotoxicity. A total of 141 patients initiated treatment early enough to have been able to complete 12 weeks on treatment [modified intent-to-treat (M-ITT) population]; of these, 133 completed the 12-week treatment phase. The proportion of subjects in the M-ITT population with HIV-1 RNA <400 copies/mL at week 12 was 50, 48, 54 and 75% in the APL 200 mg bid, APL 400 mg bid, APL 800 mg once a day (qd) and 3TC/ZDV arms, respectively. Similar responses were seen in the few subjects harbouring R5X4-tropic virus (n=17). Common clinical adverse events (AEs) were diarrhoea, nausea, fatigue and headache. APL demonstrated nonlinear pharmacokinetics with high interpatient variability. CONCLUSIONS: While target plasma concentrations of APL were achieved, the antiviral activity of APL+LPV/r did not appear to be comparable to that of 3TC/ZDV+LPV/r.

[Maraviroc: clinical trials results]. / Maraviroc: résultats des études cliniques.

Just over a decade after identification of chemokine receptors CCR5 and CXCR4 as coreceptors for HIV, maraviroc (Celsentri), the first CCR5 antagonist, has recently obtained its Marketing Authorization in the United States and Europe, for treatment of treatment-experienced adult patients infected with only CCR5-tropic HIV-1 detectable. CCR5 antagonists, after fusion inhibitor enfuvirtide available since 2003, also belong to entry inhibitors. These molecules, unlike previous antiretrovirals, do not target the virus but its target cell by blocking viral penetration. Maraviroc has shown its clinical efficacy in patients failing other antiretroviral classes. Its safety profile was similar to placebo in two large phase III trials. However, careful assessment of both hepatic and immunologic safety of this new therapeutic class is needed. Viral tropism testing has to be investigated before using maraviroc in the clinic, because CCR5 antagonists are not active against CXCR4 viruses. For the moment indicated for the treatment-experienced patient population, maraviroc could in the future benefit to other types of patients, depending on ongoing trials results.

[Cerebral vasculitis with aneurysms caused by varicella-zoster virus infection during AIDS: a new clinicoangiographical syndrome]. / Vascularite cérébrale avec sténoses et ectasies due au virus varicelle-zona au cours de l'infection par le VIH : une nouvelle entité compliquant le sida.

We describe three cases of cerebral angiopathy with aneurysms caused by a meningeal varicella-zoster virus infection occurring during AIDS. The clinical picture was rather stereotyped: severe immunocompromission due to HIV infection, ongoing multifocal cerebrovascular disease with territorial infarcts, lymphocytic meningitis with normal glucose content (two cases) or hypoglycorrhachia (one case), multifocal cerebral vasculopathy with narrowings and aneurysms, healing with or without neurological sequelae after intravenous aciclovir treatment. The diagnosis of varicella-zoster virus-induced angiopathy was ascertained by the positive specific PCR in the CSF in the three cases and by the results of the cerebromeningeal biopsy in one case. Although, varicella-zoster virus is already known as a cause of cerebral angiopathy both in the immunocompetent and the immunocompromised, these three cases are the first ever described of a particular angiopathy with narrowings and ectasias complicating AIDS. The infectious treatable cause and the risk of aggravation without treatment require early active oriented investigations in case of a patient with cerebrovascular disease occurring during HIV infection, including a CSF study with varicella-zoster PCR, to allow specific antiviral treatment. In our three cases, aciclovir intravenous treatment (30mg/kg per day) enabled VZ virus clearing from the CSF and stopped the course of the vasculopathy.

Human immunodeficiency virus type 1 (HIV-1) plasma load discrepancies between the Roche COBAS AMPLICOR HIV-1 MONITOR Version 1.5 and the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 assays.

We compared plasma viral load values obtained with COBAS AMPLICOR human immunodeficiency virus type 1 (HIV-1) MONITOR version 1.5 and with COBAS TaqMan HIV-1 assays. Mean values were 4.2 and 2.9 log(10) copies/ml, respectively, showing the lack of agreement between the two assays.

Multidrug-resistant tuberculous meningitis in an HIV-positive patient: a challenging disease.

We report two cases of disseminated multidrug-resistant tuberculosis with meningitis in HIV-positive patients, who were both recent emigrants from sub-Saharan Africa. Our two cases highlight new challenges in the care of HIV and tuberculosis coinfection including early diagnosis and treatment of multidrug-resistant tuberculosis that is spreading.