Risk factors for the environmental spread of different multidrug-resistant organisms: a prospective cohort study

BACKGROUND

Substantial scientific evidence shows that contamination of environmental surfaces in hospitals plays an important role in the transmission of multidrug-resistant organisms (MDROs). To date, studies have failed to identify the risk factors associated with environmental contamination.

AIM

To evaluate, compare, and identify factors associated with environmental contamination around carriers of different MDROs.

METHODS

This was a prospective cohort study from May 2018 to February 2020. A total of 125 patients were included, having been admitted to Avicenne Hospital and Hotel Dieu de France de Beyrouth Hospital who were faecal carriers of MDROs (extended-spectrum β-lactamase-producing Enterobacterales (ESBL-PE), carbapenemase-producing Enterobacterales (CPE), vancomycin-resistant enterococci (VRE)). For each patient, quantification of MDRO in stool was undertaken, plus a qualitative evaluation of the presence of MDRO in six different environmental sites; and clinical data were collected.

FINDINGS

MDROs comprised ESBL-PE (34%), CPE (45%), and VRE (21%). The most frequent MDRO species was Escherichia coli. Contamination of at least one environmental site was observed for 22 (18%) patients. Only carriage of VanA was associated with a significantly higher risk of dissemination. Having a urinary catheter, carriage of OXA48 and E. coli were protective factors against environmental contamination. There were no significant differences in environmental contamination between E. coli and other Enterobacterales or between ESBL-PE and CPE.

CONCLUSIONS

Hospital environmental contamination rates are substantially higher for patients with VRE, compared to the low environment dissemination rates around ESBL-PE and CPE. Further studies on a larger scale are needed to confirm the validity of our findings.

Adsorption of Heavy Metal Ions on Virgin and Chemically-Modified Lignocellulosic Materials

Amidoximated wood sawdust (Am-WS) and wood flour (Am-WF) were prepared using the same procedure as described recently for amidoximated cellulose (Am-Cell). The modified supports thus obtained were characterized by IR, TGA and DSC methods. In comparison to the untreated material, such treatment led to a considerable increase in adsorption capacity towards heavy metal ions from aqueous solution. The quantity adsorbed increased with pH, initial metal ion concentration and immersion time. The formation of a 1:1 complex between the amidoxime group and Cu(II), Cr(III) and Cd(II) ions and a 2:1 complex with the Ni(II) ion was demonstrated by the adsorption limit values. Overall, Am-WS and Am-WF exhibited similar behaviour to Am-Cell and are suitable for the treatment of wastewaters containing heavy metal ions.

The Use of Eucalyptus Barks for the Adsorption of Heavy Metal Ions and Dyes

Eucalyptus barks harvested in Lebanon were used for the adsorption of pollutants such as heavy metal ions and dyes. Washing with water or pretreatment with formaldehyde was performed on the bark powder. The adsorption capacity of this material towards CuII, CrIII, CdII and NiII was evaluated in a batch process for various parameters. The results obtained showed that the retention capacity increased with contact time, pH and initial metal ion concentration but decreased with temperature. The adsorption capacities were 2.61, 0.71, 2.24 and 0.75 mmol/g adsorbent for CuII, CrIII, CdII and NiII, respectively.

Eucalyptus barks are also very efficient for the adsorption of dyes (Acid Blue 25, Erichrome Blue Black B and Calmagite) because of interaction between the hydroxy and amino groups of the dyes and the phenolic moities of bark. This adsorption was modified when metal ions had already been adsorbed on to the barks as a result of the formation of a 1:1 complex between the dye and the metal ion. Desorption was achieved by treating with the sodium salt of ethylenediamine-tetraacetic acid (EDTA) for metal ions and by heating at 75°C in aqueous medium for dyes. After desorption, the recycling of the support was tested for potential use as a means of concentrating pollutants.

Fate of the fecal indicator Escherichia coli in irrigation with partially treated wastewater

Treated wastewater reuse is increasing in semi-arid regions as a response to the effects of climate change and increased competition for natural water resources. Investigating the fate of bacterial indicators is relevant to assess their persistence in the environment and possible transfer to groundwater or to the food chain. A long-term field-scale experimental campaign and a soil column test were carried out to evaluate the fate of the fecal indicator Escherichia coli (E. coli) in a cultivated soil when contaminated water resources are used for irrigation. For field experiments, fecal contamination was simulated by dosing the indicator to the effluent of a membrane bioreactor, thus simulating a filtration system's failure, and irrigating a test field where grass was grown. The presence of E. coli on grass and topsoil samples was monitored under different scenarios. For evaluating the fate of the same indicator in the subsoil, a set of soil columns was installed next to the field, operated, and monitored for E. coli concentration over time and along depth. Real municipal wastewater was used in this case as source of fecal contamination. Results showed that short- and medium-term effects on topsoil were strongly dependent on the concentration of E. coli in the irrigation water. Limited persistence and no relevant accumulation of the indicator on the grass and in the topsoil were observed. Watering events performed after fecal contamination did not influence significantly the decay in the topsoil, which followed a log-linear model. The trend of the E. coli concentrations in the leaching of the soil columns followed a log-linear model as well, suggesting bacterial decay as the dominant mechanism affecting the underground indicator's concentration.

Outcomes of autologous bone marrow transplantation in non-Hodgkin's lymphoma patients who failed peripheral blood stem cell mobilization

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Background: Patients (pts) with relapsed/refractory non-Hodgkin's lymphoma (NHL) who fail to mobilize adequate peripheral blood stem cells (PBSC) often undergo bone marrow (BM) harvest for autologous transplantation. The outcome of these pts is not known. Methods: In this retrospective study (May 1996-September 2006), we identified 36 out of a total of 750 pts with advanced NHL, who failed to collect adequate PBSC and subsequently underwent BM harvest followed by ABMT. Decision to harvest BM was left to the treating clinician. Median age at transplant was 53 years (range 15–73). Twenty of 36 pts (55%) were male. Histology was intermediate grade in 31 (86%) patients and low grade in 5 (14%). Twelve pts (35%) had history of BM involvement with lymphoma. Median number of chemotherapy cycles received prior to mobilization was 3 (range 1–6). At the time of stem cell mobilization 18 (50%) were in complete remission (CR), 13 (37%) were in partial remission (PR) and 5 (13%) had progressive disease (PD). Twenty four (67%) pts underwent chemo-mobilization and 12 (33%) were mobilized with cytokines alone. Results: The median total nucleated cell dose and CD34+ cell dose harvested/kg were 3.72 x 108 (range 0.25–58.0) and 1.6 x 106 (range 0.03–5.8), respectively. After ABMT, 33 of 35 evaluable (94%) pts engrafted neutrophils with median time to ANC 0.5 x 109/L of 23 days (range 8–47). Median time to platelet count 20 x 109/L was 63 days (range 11–375). Two of 35 (6 %) evaluable pts failed to engraft. After ABMT, 25/36 (70%) pts achieved a CR. The incidence of NRM at 100 days was 15%. Sixteen (45%) pts relapsed at a median of 11 months (range 2–59) from ABMT. After a median follow-up of 34 months (range 0.4–100), the 3-year OS and DFS were 47% and 35%, respectively. Causes of death were: disease progression/relapse in 15 (60%), secondary malignancy in 3 (12%), multiorgan failure in 5 (20%), and unknown in 2 (8%). Conclusions: ABMT is feasible in pts who fail to mobilize adequate PBSC, however, these pts have longer time to engraftment. Although the CR rate after transplant is high, the NRM is higher than expected. Non-myeloablative allogeneic transplantation may provide better outcomes with similar toxicity and needs to be further studied.

No significant financial relationships to disclose.

Age at diagnosis does not adversely affect outcome in patients with Hodgkin's Disease (HD) after autologous transplantation

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Background: Age at diagnosis is a poor prognostic factor for overall survival after standard therapy for HD. Whether older age is a prognostic factor for outcome after autologous transplantation is not known. We sought to evaluate the effect of older age at diagnosis on transplant outcome. Patients and Methods: All patients with HD undergoing autologous transplantation with BEAM conditioning (BCNU, Etoposide, Cytarabine, and Melphalan) between January 1996 and December 2007 were included in this study. During these 12 years, 248 patients (103 males) underwent autologous transplantation. Seventy two patients (29%) were older than 40 years of age at the time of initial diagnosis. Median age at transplantation was 31 years (range 11–74). At transplantation, 63 (25%) were in complete remission (CR); 148 (60%) were in partial remission (PR); and 37 (15%) had stable (SD) or progressive disease (PD). Forty-six patients (19%) had received more than 3 courses of chemotherapy prior to transplantation. LDH was elevated in 131 (53%). Peripheral blood stem cells were used as stem cell source in 241 (97%) patients. Results: With a median follow up of 48 months (range, 1–143 months), the 48-month overall (OS) and event-free survival (EFS) were 72% (95% CI; 65%-77%) and 57% (95% CI; 50%-63%), respectively. The cumulative incidence of non-relapse mortality at 1 year was 1.6%. The cumulative incidence of secondary MDS or AML was 8%. In univariate analysis, disease status (p<0.001) and number of prior chemotherapy regimens (p=0.007) were the only factors significantly predicting OS. Disease status was the only factor significant (p<0.01) in a multivariate analysis with a hazard ratio of 2.7 (1.1–6.9) and 9.2 (3.4–25) for patients in PR, and SD/PD respectively (CR reference group). Age at diagnosis was not a significant factor (see table ). Conclusions: High-dose chemotherapy and autologous transplantation abrogate the adverse impact of age at diagnosis in patients with HD.

[Table: see text]

No significant financial relationships to disclose.

Allopurinol improves endothelial function in sleep apnoea: a randomised controlled study

Increased oxidative stress in obstructive sleep apnoea is thought to contribute to endothelial dysfunction. The objective of this study was to test the hypothesis that inhibition of xanthine oxidase by allopurinol can improve endothelial function in patients with obstructive sleep apnoea. A randomised double-blind placebo-controlled crossover study was performed on 12 patients with moderate-to-severe obstructive sleep apnoea, comparing 300 mg allopurinol daily for 2 weeks with placebo. Endothelial function was assessed using hyperaemia-induced flow-mediated vasodilation (FMD) at baseline and following treatment. Plasma malondialdehyde levels were compared in order to assess significant changes in oxidative stress. Baseline FMD correlated significantly with the severity of sleep apnoea and the time spent with an arterial oxygen saturation of <90%. Allopurinol caused a significant increase in FMD compared to placebo (10.4+/-3.2 versus 7.4+/-2.8%, respectively). Plasma malondialdehyde levels were significantly reduced with allopurinol treatment (1.5+/-0.3 versus 1.2+/-0.3 micromol.L(-1)), consistent with reduced oxidative stress. Allopurinol improves endothelial dysfunction in patients with moderate-to-severe obstructive sleep apnoea. These observations suggest that xanthine oxidase contributes significantly to vasodilatory impairment.

Application of Multi Locus Sequence Typing to the analysis of the biodiversity of indigenous Saccharomyces cerevisiae wine yeasts from Lebanon

AIMS

To assess suitability of Multi Locus Sequence Typing (MLST) for investigating the biodiversity of wine yeast strains. This method was compared with established ones like microsatellite analysis or amplification of genomic regions flanked by repeated (delta) elements.

METHODS AND RESULTS

DNA fragments were amplified and sequenced for 26 loci representing housekeeping genes, open reading frames (ORFs) of unknown functions or intergenic regions. A set of seven loci was tested on 84 Saccharomyces cerevisiae strains, including 65 strains isolated from traditional wineries in Lebanon, commercial wine strains and Asian isolates. An overall sequence diversity of 2.05% was observed, consisting of single nucleotide polymorphisms, 60% of them occurring in a heterozygous state. The number of polymorphic sites per locus varied between 4 and 14. The same set of strains was analysed by microsatellite typing on six polymorphic loci and by interdelta amplification.

CONCLUSIONS

Clustering of MLST profiles clearly differentiated the Asian group of strains from Lebanese and European commercial strains that appear closely related. The current MLST scheme appears less discriminatory (92.27%) on closely related wine yeasts than microsatellite or interdelta typing (>99%).

SIGNIFICANCE AND IMPACT OF THE STUDY

MLST is a highly reliable method for relatedness inference and promising for wine yeast typing.

Sirolimus in combination with tacrolimus and corticosteroids for the treatment of resistant chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) remains a major cause of morbidity and mortality in haematopoietic transplant recipients. Sirolimus is a macrocyclic triene antibiotic with immunosuppressive, antifungal and antitumour properties, that has activity in the prevention and treatment of acute GVHD. We conducted a phase II trial of sirolimus combined with tacrolimus and methylprednisolone in patients with steroid-resistant cGVHD. Thirty-five patients who developed GVHD after day 100 post-transplant were studied. Six patients had a complete response and 16 a partial response with an overall response rate of 63%. Major adverse events related to the combination of tacrolimus and sirolimus were hyperlipidaemia, renal dysfunction and cytopenias. Four patients had thrombotic microangiopathy (TMA) and 27 (77%) had infectious complications. The median survival for the whole group was 15 months. A significantly better outcome was observed in patients with a platelet count > or = 100 x 10(9)/l, as well as in those with true chronic manifestations of GVHD compared to those with acute GVHD beyond day 100. Controlled trials comparing this approach with alternative strategies to determine which can best achieve the goal of GVHD-free survival are warranted.

Reduced-intensity allogeneic stem cell transplantation in relapsed and refractory Hodgkin's disease: low transplant-related mortality and impact of intensity of conditioning regimen

A total of 40 patients with relapsed/refractory Hodgkin's disease (HD) underwent reduced-intensity conditioning (RIC) allogeneic stem cell transplantation (allo-SCT) from an HLA-identical sibling (n=20) or a matched unrelated donor (n=20). The median age was 31 years (range 18-58). Disease status at allo-SCT was refractory relapse (n=14) or sensitive relapse (n=26). The conditioning regimens were fludarabine-cyclophosphamide+/-antithymocyte globulin (n=14), a less intensive regimen, and fludarabine-melphalan (FM) (n=26), a more intensive one. The two groups had similar prognostic factors. The median time to neutrophil recovery (ie absolute neutrophil count >/=500/microl) was 12 days (range 10-24). The median time to platelet recovery (ie platelet count >/=20 000/microl) was 17 days (range 7-132). Day 100 and cumulative (18-month) transplant-related mortalities (TRMs) were 5 and 22%. Twenty-four patients (60%) are alive (14 in complete remission or complete remission, unconfirmed/uncertain) with a median follow-up of 13 months (4-78). In all, 16 patients expired (TRM n=8, disease progression n=8). FM patients had better overall survival (73 vs 39% at 18 months; P=0.03), and a trend towards better progression-free survival (37 vs 21% at 18 months; P=0.2). RIC allo-SCT is feasible in relapsed/refractory HD patients with a low TRM. The intensity of the preparative regimen affects survival.

Chronic graft-versus-host disease after allogeneic blood stem cell transplantation

The incidence, characteristics, risk factors for, and impact of chronic graft-vs-host disease (GVHD) were evaluated in a consecutive series of 116 evaluable HLA-identical blood stem cell transplant recipients. Minimum follow-up was 18 months. Limited chronic GVHD occurred in 6% (95% confidence interval [CI], 0%-13%), and clinical extensive chronic GVHD in 71% (95% CI, 61%-80%). The cumulative incidence was 57% (95% CI, 48%-66%). In univariate analyses, GVHD prophylaxis other than tacrolimus and methotrexate, prior grades 2 to 4 acute GVHD, use of corticosteroids on day 100, and total nucleated cell dose were significant risk factors for clinical extensive chronic GVHD. On multivariate analysis, GVHD prophylaxis with tacrolimus and methotrexate was associated with a reduced risk of chronic GVHD (hazard ratio [HR], 0.35; P =.001), whereas the risk was increased with prior acute GVHD (HR, 1.67; P =.046). When adjusted for disease status at the time of transplantation, high-risk chronic GVHD had an adverse impact on overall mortality (HR, 6.6; P <.001) and treatment failure (HR, 5.2; P <.001) at 18 months. It was concluded that there is a substantial rate of chronic GVHD after HLA-identical allogeneic blood stem cell transplantation, that clinical factors may alter the risk of chronic GVHD, and that high-risk chronic GVHD adversely affects outcome.

Tacrolimus does not abrogate the increased risk of acute graft-versus-host disease after unrelated-donor marrow transplantation with allelic mismatching at HLA-DRB1 and HLA-DQB1

One hundred patients of median age 34 years (range, 14-53) received bone marrow transplants from unrelated donors serologically matched for human leukocyte antigen HLA-A, HLA-B, and HLA-DR using tacrolimus and minimethotrexate for prevention of acute graft-versus-host disease (GVHD). Sixty-eight patient-donor pairs had allelic matches at HLA-DRB1 and HLA-DQB1, 20 pairs had a single mismatch at HLA-DRB1 or HLA-DQB1, and 12 were mismatched at both HLA-DRB1 and HLA-DQB1. Minimum follow-up time was 6 months. Grades 2 to 4 GVHD occurred in 43% of patients with matched donors, 69% with single allele-mismatched donors, and 71% with double allele-mismatched donors; grades 3 to 4 GVHD occurred in 22%, 43%, and 64%, respectively. On multivariate analysis, the relative risk of grades 2 to 4 GVHD was 2.2 (95% CI, 1.1-4.5; P = .03) with a single allele mismatch and 2.7 (95% CI, 1.2-6.0; P = .02) with a double allele mismatch. The relative risks of grades 3 to 4 GVHD were 3.0 (95% CI, 1.2-7.6; P = .02) and 5.0 (95% CI, 1.9-12.6; P = .001), respectively. Day 100 treatment-related mortality was also adversely affected by allelic mismatching, occurring in 21% of those with matched donors, 50% with single allele-mismatched donors, and 42% with double allele-mismatched donors (P = .02), but overall survival at day 180 did not differ significantly among the 3 groups. Tacrolimus does not abrogate the adverse impact of allele mismatching at HLA-DRB1 and HLA-DQB1 on the risk of moderate-to-severe acute GVHD.

[Steroid ligands of androgen binding protein. The enantiomers of trans-trans and cis-trans perhydrohexestrols and trans-trans perhydrodiketones]

In the framework of a study on nonsteroidal androgens, the authors previously observed that in perhydrohexestrol series, the (+/-)-[(cis-4 hydroxycyclohexyl)-4(trans-4 hydroxycyclohexyl)-hexane] or cis-trans perhydrohexestrol and especially the (+/-)-(3,4 bis (trans-4-oxocyclohexyl)-hexane) or trans-trans perhydrodiketone, there is no affinity for AR (androgen receptor of the prostate) but they bind with high and specific affinity to the testosterone binding sites on ABP (epididymal androgen-binding protein). In this work, we describe the preparation, the stereochemistry and biological activities of trans-trans and cis-trans perhydrohexestrols and of trans-trans perhydrodiketone as well as their corresponding enantiomers. Biologically the tests AR and ABP are negative for the trans-trans perhydrohexestrol and of trans-trans perhydrodiketone and for its enantiomers. However for the enantiomers of cis-trans perhydrohexestrol and of trans-trans perhydrodiketone, the affinity of the (+) enantiomer for ABP is superior to that of the racemic and that of the (-) enantiomer, whereas the affinity for AR are zero. Chemically, the stereochemistry of the three racemics has been established by X-ray crystallographic analysis or by 1H n.m.r. The n.m.r. spectra have been analyzed in terms of chemical shifts and coupling constants.