Metagenomic analysis of MWWTP effluent treated via solar photo-Fenton at neutral pH: Effects upon microbial community, priority pathogens, and antibiotic resistance genes.

The effectiveness of advanced technologies on eliminating antibiotic resistant bacteria (ARB) and resistance genes (ARGs) from wastewaters have been recently investigated. Solar photo-Fenton has been proven effective in combating ARB and ARGs from Municipal Wastewater Treatment Plant effluent (MWWTPE). However, most of these studies have relied solely on cultivable methods to assess ARB removal. This is the first study to investigate the effect of solar photo-Fenton upon ARB and ARGs in MWWTPE by high throughput metagenomic analysis (16S rDNA sequencing and Whole Genome Sequencing). Treatment efficiency upon priority pathogens and resistome profile were also investigated. Solar photo-Fenton (30 mg L-1 of Fe2+ intermittent additions and 50 mg L-1 of H2O2) reached 76-86% removal of main phyla present in MWWTPE. An increase in Proteobacteria abundance was observed after solar photo-Fenton and controls in which H2O2 was present as an oxidant (Fenton, H2O2 only, solar/H2O2). Hence, tolerance mechanisms presented by this group should be further assessed. Solar photo-Fenton achieved complete removal of high priority Staphylococcus and Enterococcus, as well as Klebsiella pneumoniae and Pseudomonas aeruginosa. Substantial reduction of intrinsically multi-drug resistant bacteria was detected. Solar photo-Fenton removed nearly 60% of ARGs associated with sulfonamides, macrolides, and tetracyclines, and complete removal of ARGs related to ß-lactams and fluoroquinolones. These results indicate the potential of using solar-enhanced photo-Fenton to limit the spread of antimicrobial resistance, especially in developing tropical countries.

Combat of antimicrobial resistance in municipal wastewater treatment plant effluent via solar advanced oxidation processes: Achievements and perspectives.

This review aims to gather main achievements and limitations associated to the application of solar photocatalytic processes with regard to the removal of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) from municipal wastewater treatment plant effluent (MWWTPE). Solar photocatalytic processes were chosen considering the context of developing tropical countries. Among these processes, solar photo-Fenton has been proved effective for the elimination of ARB from MWWTPE at neutral pH in bench and pilot scale and also under continuous flow. Yet, ARG removal varies as according to the gene. Irradiation intensity and matrix composition play a key role on treatment efficiency for this purpose. The use of sulfate radical in modified solar photo-Fenton is still incipient for ARB and ARG removal. Also, investigations related to ARB resistance profile and horizontal gene transfer rates after solar photo-Fenton treatment must be further analyzed. Regarding solar heterogeneous photocatalysis, TiO2 and TiO2-composites applied in suspension are the most commonly investigated for the removal of ARB and ARGs. Irradiation intensity, temperature and catalyst dosage affect treatment efficiency. However, most studies were performed in synthetic solutions using reduced sample volumes. Extended exposition times and addition of H2O2 to the system (solar/TiO2/H2O2) are required to prevent bacteria regrowth and ensure ARG abatement. In addition, enhancement of TiO2 with graphene or (semi)metals improved ARB elimination. Differences concerning irradiation intensity, matrix composition, catalyst dosage, and model ARB and ARGs used in studies analyzed in this review hinder the comparison of photocatalysts synthesized by various research groups. Finally, future research should aim at evaluating the efficiency of solar photocatalytic processes in real matrices originated from sewage treatment systems applied in developing countries; determining indicators of antimicrobial resistance in MWWTPE; and investigating ARB mutation rate as well as the removal of cell-free ARGs present in suspension in MWWTPE.

A New Synthetic Peptide with In vitro Antibacterial Potential Against Escherichia coli O157:H7 and Methicillin-Resistant Staphylococcus aureus (MRSA).

In this work, we performed the rational design of a cationic antimicrobial peptide, GIBIMPY4, using the software DEPRAMPs developed at the GIBIM research group. GIBIMPY4 has a length of 17 amino acids, it is amphipathic, its structure is α-helix and it has a net charge of (+5). Solid-phase peptide synthesis was performed using the Fmoc strategy in acid medium. The primary structure was confirmed by MALDI-TOF mass spectrometry. The antimicrobial activity of the peptide was evaluated by broth microdilution method by measuring optical density in 96-well microplates. The minimal inhibitory concentration of GIBIMPY4 to kill 50 % of the bacterial cells (MIC50) was 6.20 ± 0.02 µM for MRSA and 4.55 ± 0.02 µM for E. coli O157:H7, while also reporting a bacteriostatic effect for the later. GIBIMPY4 activity was sensitive to salt concentration in E. coli but insignificant effect in its activity against MRSA. The peptide seems to be a broad-spectrum antimicrobial agent based on the results against Gram-positive and Gram-negative bacteria and was specific for bacterial cells E. coli O157:H7 with index of specificity equal to 9.01 in vitro assays.

The influence of extreme body weight on clinical outcome of patients with venous thromboembolism: findings from a prospective registry (RIETE).

BACKGROUND: Data evaluating the safety of using weight-based dosing of low-molecular-weight heparin (LMWH) in either underweight or obese patients with venous thromboembolism (VTE) are limited. Thus, recommendations based on evidence from clinical trials might not be suitable for patients with extreme body weight. PATIENTS AND METHODS: Patients with objectively confirmed, symptomatic acute VTE are consecutively enrolled into the Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) registry. For this analysis, data from patients in the following ranges of body weight were examined: <50, 50-100, and >100 kg. Patient characteristics, underlying conditions, treatment schedules and clinical outcomes during the first 15 days of treatment were compared. RESULTS: As of August 2004, 8845 patients with acute VTE were enrolled from 94 participating centers. Of these, 169 (1.9%) weighed <50 kg, 8382 (95%) weighed 50-100 kg and 294 (3.3%) weighed >100 kg. Patients weighing <50 kg were more commonly females, were taking non-steriodal antiinflammatory drugs (NSAIDs), and had severe underlying diseases more often than patients weighing 50-100 kg. Their incidence of overall bleeding complications was significantly higher than in patients weighing 50-100 kg (odds ratio 2.2; 95% CI: 1.2-4.0). Patients weighing >100 kg were younger, most commonly males, and had cancer less often than those weighing 50-100 kg. Incidences of recurrent VTE, fatal pulmonary embolism or major bleeding complications were similar in both groups. CONCLUSIONS: Patients with VTE weighing <50 kg have a significantly higher rate of bleeding complications. The clinical outcome of patients weighing over 100 kg was not significantly different from that in patients weighing 50-100 kg.

[Fever of unknown origin in HIV positive patients]. / Fiebre de origen desconocido en pacientes VIH positivos.

OBJECTIVES: To describe the clinical presentation of FUO in patients infected with HIV and to asses the diagnostic usefulness in this population of several test usually recommended in the study of FUO. PATIENTS AND METHODS: We studied the clinical charts of all patients with HIV that required admission to our Hospital during a 23-month period. FUO was defined according to Petersdorf's modified criteria. Fifty-four patients fulfilled study criteria during the entry period. RESULTS: A cause of fever was identified for 48 patients (89%). Tuberculosis, disseminated atypical mycobacteriosis and Leishmaniasis can explain 68% of them. Examination of bone marrow aspirates, lymph node aspirates and biopsy, and culture of clinical specimens for mycobacteria were the procedures with the highest diagnostic yield. CONCLUSIONS: Mycobacterial infection should be considered as a first-line diagnosis in HIV-patients with FUO. It is possible to predict the diagnosis of tuberculosis infection with a high level of confidence (90.5%) through a logistic regression model based on easily obtainable parameters.

[Thrombopenia associated to localized scleroderma]. / Trombopenia asociada a esclerodermia localizada.

Two patients are reported with localized scleroderma who developed thrombocytopenia. One of these patients had a positive antinuclear antibody (ANA) and Anti-DNA antibodies tests. The occurrence of thrombocytopenia in localized scleroderma suggests an autoimmune mechanism, by the response to steroids and the presence of positive autoantibodies. This possible association emphasizes the need to look for hematologic disorders in patients with systemic, as well as localized scleroderma.

Fiebre de origen desconocido en pacientes HIV positivos / Fever on unknown origin in patients with HIV

Objetivos: Describir la presentación clínica y la utilidad de los de tests diagnósticos habitualmente recomendados en el estudio de la fiebre de origen desconocido (FOD) en los pacientes VIH positivos.Pacientes y métodos: Incluimos en el estudio a los 54 pacientes con infección por el VIH que ingresaron en nuestro Hospital por FOD durante un periodo de 23 meses. La FOD fue definida de acuerdo con los criterios modificados de Petersdorf´s. Resultados: La causa de la fiebre se identificó en 48 casos (89 por ciento). La tuberculosis, la micobacteriosis atípica y la leishmaniasis pueden explicar el 68 por ciento de los casos. El aspirado de médula ósea, la punción aspiración o la biopsia de los ganglios linfáticos y los cultivos para micobacterias fueron las pruebas diagnósticas más rentables. Conclusiones: La infección por micobacterias debe ser el primer diagnóstico de sospecha en los pacientes VIH positivos con FOD. Es posible precedir el diagnóstico de tuberculosis con una alta precisión (90,5 por ciento) con un modelo de regresión logística basado en datos clínicos y analíticos fácilmente obtenibles. (AU)

Trombopenia asociada a esclerodermia localizada / Thrombocytopenia associated to localized scleroderma

Presentamos dos pacientes con esclerodermia localizada que desarrollaron trombocitopenia. En uno de los casos se evidenció ANA y anticuerpos anti-DNA positivo. La aparición de trombocitopenia en esclerodermia localizada sugiere un mecanismo autoinmune, tanto por la respuesta a esteroides como por la existencia de autoanticuerpos. Esta posible asociación establece la necesidad de buscar alteraciones hematológicas, tanto en la esclerodermia sistémica, como en la localizada. (AU)