Azithromycin removal using pine bark, oak ash and mussel shell.

Adsorption is considered an interesting option for removing antibiotics from the environment because of its simple design, low cost, and potential efficiency. In this work we evaluated three by-products (pine bark, oak ash, and mussel shell) as bio-adsorbents for the antibiotic azithromycin (AZM). Furthermore, they were added at doses of 48 t ha-1 to four different soils, then comparing AZM removal for soils with and without bio-adsorbents. Batch-type experiments were used, adding AZM concentrations between 2.5 and 600 µmol L-1 to the different bio-adsorbents and soil + bio-adsorbent mixtures. Regarding the bio-adsorbents, oak ash showed the best adsorption scores (9600 µmol kg-1, meaning >80% retention), followed by pine bark (8280 µmol kg-1, 69%) and mussel shell (between 3000 and 6000 µmol kg-1, 25-50% retention). Adsorption data were adjusted to different models (Linear, Freundlich and Langmuir), showing that just mussel shell presented an acceptable fitting to the Freundlich equation, while pine bark and oak ash did not present a good adjustment to any of the three models. Regarding desorption, the values were always below the detection limit, indicating a rather irreversible adsorption of AZM onto these three by-products. Furthermore, the results showed that when the lowest concentrations of AZM were added to the not amended soils they adsorbed 100% of the antibiotic, whereas when the highest concentrations of AZM were spread, the adsorption decreased to 55%. However, when any of the three bio-adsorbents was added to the soils, AZM adsorption reached 100% for all the antibiotic concentrations used. Desorption was null in all cases for both soils with and without bio-adsorbents. These results, corresponding to an investigation carried out for the first time for the antibiotic AZM, can be seen as relevant in the search of low-cost alternative treatments to face environmental pollution caused by this emerging contaminant.

Experimental data and modeling of sulfadiazine adsorption onto raw and modified clays from Tunisia.

In recent years, the increasing detection of emerging pollutants (particularly antibiotics, such as sulfonamides) in agricultural soils and water bodies has raised growing concern about related environmental and health problems. In the current research, sulfadiazine (SDZ) adsorption was studied for three raw and chemically modified clays. The experiments were carried out for increasing doses of the antibiotic (0, 1, 5, 10, 20, and 40 µmol L-1) at ambient temperature and natural pH with a contact time of 24 h. The eventual fitting to Freundlich, Langmuir and Linear adsorption models, as well as residual concentrations of antibiotics after adsorption, was assessed. The results obtained showed that one of the clays (HJ1) adsorbed more SDZ (reaching 99.9 % when 40 µmol L-1 of SDZ were added) than the other clay materials, followed by the acid-activated AM clay (which reached 99.4 % for the same SDZ concentration added). The adsorption of SDZ followed a linear adsorption isotherm, suggesting that hydrophobic interactions, rather than cation exchange, played a significant role in SDZ retention. Concerning the adsorption data, the best adjustment corresponded to the Freundlich model. The highest Freundlich KF scores were obtained for the AM acid-treated and raw HJ1 clays (606.051 and 312.969 Ln µmol1-n kg-1, respectively). The Freundlich n parameter ranged between 0.047 and 1.506. Regarding desorption, the highest value corresponded to the AM clay, being generally <10 % for raw clays, <8 % for base-activated clays, and <6 % for acid-activated clays. Chemical modifications contributed to improve the adsorption capacity of the AM clay, especially when the highest concentrations of the antibiotic were added. The results of this research can be considered relevant as regard environmental and public health assessment since they estimate the feasibility of three Tunisian clays in SDZ removal from aqueous solutions.

Tetracycline adsorption/desorption by raw and activated Tunisian clays.

Clay-based adsorbents have applications in environmental remediation, particularly in the removal of emerging pollutants such as antibiotics. Taking that into account, we studied the adsorption/desorption process of tetracycline (TC) using three raw and acid- or base-activated clays (AM, HJ1 and HJ2) collected, respectively, from Aleg (Mazzouna), El Haria (Jebess, Maknessy), and Chouabine (Jebess, Maknessy) formations, located in the Maknessy-Mazzouna basin, center-western of Tunisia. The main physicochemical properties of the clays were determined using standard procedures, where the studied clays presented a basic pH (8.39-9.08) and a high electrical conductivity (446-495 dS m-1). Their organic matter contents were also high (14-20%), as well as the values of the effective cation exchange capacity (80.65-97.45 cmolckg-1). In the exchange complex, the predominant cations were Na and Ca, in the case of clays HJ1 and AM, while Mg and Ca were dominant in the HJ2 clay. The sorption experimental setup consisted in performing batch tests, using 0.5 g of each clay sample, adding the selected TC concentrations, then carrying out quantification of the antibiotic by means of HPL-UV equipment. Raw clays showed high adsorption potential for TC (close to 100%) and very low desorption (generally less than 5%). This high adsorption capacity was also present in the clays after being activated with acid or base, allowing them to adsorb TC in a rather irreversible way for a wide range of pH (3.3-10) and electrical conductivity values (3.03-495 dS m-1). Adsorption experimental data were studied as regards their fitting to the Freundlich, Langmuir, Linear and Sips isotherms, being the Sips model the most appropriate to explain the adsorption of TC in these clays (natural or activated). These results could help to improve the overall knowledge on the application of new low-cost methods, using clay based adsorbents, to reduce risks due to emerging pollutants (and specifically TC) affecting the environment.

Microbiological and physicochemical quality enhancement of treated wastewater using raw and chemically modified clays from Sidi Bouzid region, Tunisia.

Environmental discharge of wastewater represents a source of chemical and biological pollutants. This study firstly evaluates the microbiological and physicochemical quality of treated wastewaters collected from two wastewater treatment plants (WWTPs) located in two different Tunisian cities namely Sidi Bouzid (SB) and Gafsa (G). Then, the capacity of three raw and acid/base-activated local clays to enhance the quality of wastewaters was assessed. The results indicate that the quantities of enteric bacteria (oscillating from 1.381 × 103 to 1.4 × 108 CFU/100 mL), fungi (between 1.331 × 103 and 1.781 × 104 CFU/100 mL), as well as SARS-CoV-2 (between 4.25 × 103 and 5.05 × 105 CFU/100 mL) and Hepatitis A virus RNA (form 4.25 × 103 to 7.4 × 104 CFU/100 mL) detected in effluent wastewaters were not in compliance with the Tunisian standards for both studied WWTPs. Likewise for other indicators such as electrical conductivity (ranging 4.9-5.4 mS/cm), suspended matter (145-160 g l-1), chemical oxygen demand (123-160 mg l-1), biological oxygen demand 5 (172-195 mg l-1), chloride, Total Kjeldahl nitrogen (TKN) and phosphorus contents (710, 58-66 and 9.47-10.83 mg l-1 respectively), the registered values do not agree with the set standards established for wastewater treatment. On the other hand, the pH values fitted (oscillating from 6.86 (at G) to 7.24 (at SB) with the Tunisian standards for both WWTPs. After treatment, wastewaters showed better values for the microbiological parameters, especially for the clays designed as AM and HJ1, which eliminated 100% of viruses. In addition, when acid-activated AM clays were applied, a marked improvement in the quality of physicochemical parameters was obtained, especially for suspended matter (2 and 4 g l-1 for SB and G, respectively), TKN (5.2 (SB) and 6.40 (G) mg/l), phosphorus (1.01 (SB) and 0.81 (G) mg/l). Our results open perspectives for the possibility of efficiently using these specific clays in the enhancement of the quality of treated wastewaters.

Adsorption of antibiotics on bio-adsorbents derived from the forestry and agro-food industries.

Antibiotic consumption at high levels in both human and veterinary populations pose a risk to their eventual entry into the food chain and/or water bodies, which will adversely affect the health of living organisms. In this work, three materials from forestry and agro-food industries (pine bark, oak ash and mussel shell) were investigated as regards their potential use as bio-adsorbents in the retention of the antibiotics amoxicillin (AMX), ciprofloxacin (CIP) and trimethoprim (TMP). Batch adsorption/desorption tests were conducted, adding increasing concentrations of the pharmaceuticals individually (from 25 to 600 µmol L-1), reaching maximum adsorption capacities of ≈ 12000 µmol kg-1 for the three antibiotics, with removal percentages of ≈ 100% for CIP, 98-99% adsorption for TMP onto pine bark, and 98-100% adsorption for AMX onto oak ash. The presence of high calcium contents and alkaline conditions in the ash favored the formation of cationic bridges with AMX, whereas the predominance of hydrogen bonds between pine bark and TMP and CIP functional groups explain the strong affinity and retention of these antibiotics. The Freundlich's model provided the best prediction for AMX adsorption onto oak ash and mussel shell (heterogeneous adsorption), whereas the Langmuir's model described well AMX adsorption onto pine bark, as well as CIP adsorption onto oak ash (homogeneous and monolayer adsorption), while all three models provided satisfactory results for TMP. In the present study, the results obtained were crucial in terms of valorization of these adsorbents and their subsequent use to improve the retention of antibiotics of emerging concern in soils, thereby preventing contamination of waters and preserving environment quality.

New data on microorganisms in soil and other environmental compartments.

As indicated in the presentation of this Virtual Special Issue (VSI), as well as in its Call for Papers, the occurrence, fate, dynamics, effects and overall repercussions of the enormous variety of microorganisms present in soils and other environmental compartments on Earth, is of huge importance, and particularly it is fundamental to the conditioning of life and even to the time-course evolution of non-living constituents of our planet. With that in mind, shedding further light on some selected fields within this broad spectrum of research themes could be seen as an ambitious objective, but achievable when limited to progressing just a few steps forward, even if the long-term aim could be to reach a final and complete characterization and solution of all issues related to these broad lines of research and fields of knowledge. In view of this, the Editors of the Special Issue made a specific Call to receive contributions to increase the knowledge on the matter, which could stimulate future additional research. With a total number of 45 manuscripts received and 16 high-quality contributions published, we think this main objective was reached with the resulting papers now available.

Cu and As(V) Adsorption and Desorption on/from Different Soils and Bio-Adsorbents.

This research is concerned with the adsorption and desorption of Cu and As(V) on/from different soils and by-products. Both contaminants may reach soils by the spreading of manure/slurries, wastewater, sewage sludge, or pesticides, and also due to pollution caused by mining and industrial activities. Different crop soils were sampled in A Limia (AL) and Sarria (S) (Galicia, NW Spain). Three low-cost by-products were selected to evaluate their bio-adsorbent potential: pine bark, oak ash, and mussel shell. The adsorption/desorption studies were carried out by means of batch-type experiments, adding increasing and individual concentrations of Cu and As(V). The fit of the adsorption data to the Langmuir, Freundlich, and Temkin models was assessed, with good results in some cases, but with high estimation errors in others. Cu retention was higher in soils with high organic matter and/or pH, reaching almost 100%, while the desorption was less than 15%. The As(V) adsorption percentage clearly decreased for higher As doses, especially in S soils, from 60−100% to 10−40%. The As(V) desorption was closely related to soil acidity, being higher for soils with higher pH values (S soils), in which up to 66% of the As(V) previously adsorbed can be desorbed. The three by-products showed high Cu adsorption, especially oak ash, which adsorbed all the Cu added in a rather irreversible manner. Oak ash also adsorbed a high amount of As(V) (>80%) in a rather non-reversible way, while mussel shell adsorbed between 7 and 33% of the added As(V), and pine bark adsorbed less than 12%, with both by-products reaching 35% desorption. Based on the adsorption and desorption data, oak ash performed as an excellent adsorbent for both Cu and As(V), a fact favored by its high pH and the presence of non-crystalline minerals and different oxides and carbonates. Overall, the results of this research can be relevant when designing strategies to prevent Cu and As(V) pollution affecting soils, waterbodies, and plants, and therefore have repercussions on public health and the environment.

Potential of low-cost bio-adsorbents to retain amoxicillin in contaminated water.

Sewage sludge as agricultural amendment is the main route of human-medicine antibiotics to enter soils. When reaching environmental compartments, these compounds can cause significant risks to human and ecological health. Specifically, the antibiotic amoxicillin (AMX) is highly used in medicine, and the fact that more than 80% of the total ingested is excreted increases the chances of causing serious environmental and public health problems. As the use of low-cost bio-adsorbents could help to solve these issues, this research focuses on the retention of AMX onto four by-products of the forestry industry (eucalyptus leaf, pine bark, pine needles, and wood ash) and one from food industry (mussel shell). To carry out this study, batch-type tests were performed, where increasing concentrations of the antibiotic (0, 2.5, 5, 10, 20, 30, 40 and 50 µmol L-1) were added to samples of 0.5 g of each bio-adsorbent. Eucalyptus leaf, pine needle and wood ash showed adsorption scores higher than 80%, while it was up to 39% and 48% for pine bark and mussel shell, respectively. For pine bark, wood ash and mussel shell, adsorption data showed good adjustment to the Freundlich and Linear models, while pine needles and eucalyptus leaf did not fit to any model. There was not desorption when the maximum concentration of AMX (50 µmol L-1) was added. Overall, eucalyptus leaf, pine needles and wood ash can be considered good bio-adsorbents with high potential to retain AMX, which has significant implications regarding their eventual use to reduce risks of environmental pollution by this antibiotic.

Amoxicillin Retention/Release in Agricultural Soils Amended with Different Bio-Adsorbent Materials.

The antibiotic amoxicillin (AMX) may reach soils and other environmental compartments as a pollutant, with potential to affect human and environmental health. To solve/minimize these hazards, it would be clearly interesting to develop effective and low-cost methods allowing the retention/removal of this compound. With these aspects in mind, this work focuses on studying the adsorption/desorption of AMX in different agricultural soils, with and without the amendment of three bio-adsorbents, specifically, pine bark, wood ash and mussel shell. For performing the research, batch-type experiments were carried out, adding increasing concentrations of the antibiotic to soil samples with and without the amendment of these three bio-adsorbents. The results showed that the amendments increased AMX adsorption, with pine bark being the most effective. Among the adsorption models that were tested, the Freundlich equation was the one showing the best fit to the empirical adsorption results. Regarding the desorption values, there was a decrease affecting the soils to which the bio-adsorbents were added, with overall desorption not exceeding 6% in any case. In general, the results indicate that the bio-adsorbents under study contributed to retaining AMX in the soils in which they were applied, and therefore reduced the risk of contamination by this antibiotic, which can be considered useful and relevant to protect environmental quality and public health.

Relevance of sorption in bio-reduction of amoxicillin taking place in forest and crop soils.

The fate of antibiotics reaching soils is a matter of concern, given its potential repercussions on public health and the environment. In this work, the potential bio-reduction of the antibiotic amoxicillin (AMX), affected by sorption and desorption, is studied for 17 soils with clearly different characteristics. To carry out these studies, batch-type tests were performed, adding increasing concentrations of AMX (0, 2.5, 5, 10, 20, 30, 40, and 50 µmol L-1) to the soils. For the highest concentration added (50 µmol L-1), the adsorption values for forest soils ranged from 90.97 to 102.54 µmol kg-1 (74.21-82.41% of the amounts of antibiotic added), while the range was 69.96-94.87 µmol kg-1 (68.31-92.56%) for maize soils, and 52.72-85.40 µmol kg-1 (50.96-82.55%) for vineyard soils. When comparing the results for all soils, the highest adsorption corresponded to those more acidic and with high organic matter and non-crystalline minerals contents. The best adjustment to adsorption models corresponded to Freundlich's. AMX desorption was generally <10%; specifically, the maximum was 6.5% in forest soils, and 16.9% in agricultural soils. These results can be considered relevant since they cover agricultural and forest soils with a wide range of pH and organic matter contents, for an antibiotic that, reaching the environment as a contaminant, can pose a potential danger to human and environmental health.

Effect of repeated soil heating at different temperatures on microbial activity in two burned soils.

The effect of fire severity and recurrence on the recovery of enzymatic activities (ß-glucosidase, urease, acid phosphatase) and bacterial activity was monitored. Unburned and burned soil samples from soil affected by a high severity wildfire and by a low severity experimental fire were subjected in laboratory to a temperature gradient to simulate different fire severities. These samples were subjected to a second laboratory heat treatment to simulate the effect of recurrence. Soil temperature was measured and used to calculate the degree-hours reached by the soil. The results showed: a) a strong effect of repeated soil heating at different temperatures on soil microbial activity; b) a different sensitivity of enzymatic activities and bacterial activity to fire, c) the magnitude of changes in these biochemical properties was related to the extent of heat supplied to samples and the previous fire/heat history, and d) degree-hours are adequate to quantify the severity of heat treatments and to examine their effects on soil microbial activity. The relationships between degree-hours and the different biochemical properties analyzed clearly demonstrate that the usefulness of these biochemical properties to detect the soil microbial community response to the heat stress followed the order: urease activity > acid phosphatase activity > ß-glucosidase activity ≫ bacterial activity.

Durations of Opioid, Nonopioid Drug, and Behavioral Clinical Trials for Chronic Pain: Adequate or Inadequate?

OBJECTIVES: A recent US federal review and clinical guideline on opioids for chronic pain asserted that the literature contributes no evidence on efficacy because all trials had "inadequate duration." To explore the evidence, we examined durations of studies on opioid, nonopioid drug, and behavioral therapies for chronic pain. METHODS: We retrieved Cochrane reviews of anticonvulsants, antidepressants, NSAIDs, opioids, or behavioral interventions for chronic pain. We also examined all opioid treatment studies retrieved for the federal evidence report but excluded due to "inadequate duration." RESULTS: Of 378 Cochrane reviews retrieved, 72 evaluated one of the five therapies. Six of these 72 were excluded because they were proposals without data or investigated acute pain. Fourteen addressed multiple interventions, leaving 52 for analysis. We graphed numbers of trials vs duration for the five treatments reviewed in the Cochrane Library, compared with durations of opioid trials dropped from the federal evidence report. Most graphs were overdispersed Poisson distributions. Nearly all trials had active treatment durations of 12 weeks or less. CONCLUSIONS: No common nonopioid treatment for chronic pain has been studied in aggregate over longer intervals of active treatment than opioids. To dismiss trials as "inadequate" if their observation period is a year or less is inconsistent with current regulatory standards. The literature on major drug and nondrug treatments for chronic pain reveals similarly shaped distributions across modalities. Considering only duration of active treatment in efficacy or effectiveness trials, published evidence is no stronger for any major drug category or behavioral therapy than for opioids.

Aciduria glutárica tipo I: descripción del primer caso clínico nacional / Type I glutaric aciduria: first national case report

Presentamos el primer caso nacional de un niño portador de una aciduria glutárica tipo I. Esta afección es un error congénito del metabolismo de los aminoácidos esenciales lisina y triptofano determinado por la deficiencia de la enzima mitocondrial glutaril-coenzima A deshidrogenasa, y en nuestro paciente se presenta como la forma clásica ded la enfermedad con síntomas neurológicos de instalación aguda que involucran principalmente el sistema extrapiramidal. El diagnóstico se realiza al evidedniar la presencia del ácido 3-hidroxiglutárico, específico de esta afección. El tratamiento está dirigido a evitar el compromiso neurológico en los casos asintomáticos ya que una vez instalado el daño neurológico es irreversible.

Infección urinaria en niños internados: características clínicas, bacteriológicas e imagenológicas

La infección urinaria es la enfermedad nefrológica que más frecuentemente motiva internación en niños. El objetivo de este estudio es realizar un análisis de características clínicas, bacteriológicas e imagenológicas en niños internados por esta enfermedad en un Servicio de Pediatría. En el período setiembre de 2001-mayo de 2002 ingresaron 60 niños de 0 a 14 años con diagnóstico de infección urinaria. 85% fueron menores de dos años, con predominio en el sexo femenino (65%). La fiebre constituyó el síntoma más frecuente, las manifestaciones digestivas fueron las segundas en jerarquía, el síndrome cistítico se observó en 10% de los casos. Escherichia coli constituyó el germen predominante: 81,7%, Klebsiella 10%, Proteus 3,3%, Enterobacter 1,7%. Se constató baja sensibilidad de estos gérmenes a ampicilina y cefalotina, intermedia para TMP-SMX y alta para cefuroxime. La ecografía renal fue patológica en 19,3% de los casos, con una baja sensibilidad para detección de anomalías parenquimatosas demostradas por estudio centellográfico: 12,5%, así como de reflujo vesicoureteral: 36%. El estudio con 99Tc DMSA mostró 65% de resultados patológicos. La asociación de fiebre, leucocitosis >15.000 elementos/mm3 y proteína C positiva fue más frecuente en casos de DMSA positivos: 44% frente a los casos de DMSA negativos: 12%. En dos pacientes con resultados dudosos del urocultivo, este estudio permitió realizar el diagnóstico de pielonefritis aguda. La uretocistografía retrógrada demostró reflujo vésico-ureteral en 40,7% de los pacientes. El alto porcentaje de niños en los que no se logró la realización de este estudio (55%), alerta acerca del subdiagnóstico de esta patología y conduce a plantear diferentes estrategias para su estudio.

A IU é uma doença nefrológica que com mais freqüência motiva internação em crianças. O objetivo deste estudo é realizar uma análise de características clínicas, bacteriológicas e imagenológicas em crianças internadas devido a esta patologia num Serviço de Pediatria. No período 09/2001-05/2002 ingressaram 60 crianças de 0-14 anos com diagnóstico de IU. O 85% foram crianças como menos de 2 anos com predomínio no sexo feminino > 65%. A febre constitui o sintoma mais freqüente, as manifestações digestivas foram as segundas, a síndroma cistítico observou-se em 10% dos casos. Escheríchia coli constitui um germe predominante: 81,7%, Klebsiella Proteus 3,3%, Enterobacter 1,7%. Constatou-se baixa sensibilidade destes germes à ampicilina e cefalotina, intermédia para TMP- SMX e alta para cerufoxime. A ecografia renal foi patológica em 19,3% dos casos com a baixa sensibilidade para detectar anomalias parenquimatosas demostradas por estudo centellográfico: 12,5%, assim como de refluxo vesicoureteral: 36%. O estudo com 99Tc DMSA mostrou 65% de resultados patológicos. A associação de febre, leucocitosis > 15.000 e proteína C positiva foi mais freqüente em casos de DMSA positivos: 44% em comparação aos casos de DMSA negativos: 12%. Em dois pacientes com resultados duvidosos do urocultivo este estudo permitiu realizar o diagnóstico de pielonefritis aguda. A uretocisografía retrograda demostrou RVU em 40,7% dos pacientes. A alta percentagem de crianças nas que não se logrou a realização deste estudo: 55%, alerta referente ao subdiagnóstico desta patologia e conduz a estudar diferentes estratégias para seu estudo.

Urinary tract infection (UTI) is the nephrologic disease that most commonly determines hospital admission in children. The purpose of this prospective study is to analize the clinical, bacteriologic and imagenologic caratheristics of children with this disease in a Pediatric hospital setting. Sixty children were admitted with the diagnosis of UTI in the period 9/2001- 5/2002. 85% were less than 2 years old; 65% were females. Fever was the most frecuent symptom, gastrointestinal manifestations were second in importance, cystitis syndrome was observed in 10% of the patients. Escherichia coli was the predominant etiologic agent: 81,7%, Klebsiella in 10%, Proteus 3,3%, Enterobacter 1,7%. It was observed low sensitivity of these bacterias to ampicillin and cefalotine, intermediate to trimetroprim-sulfametoxasol and high sensitivity to cefuroxime. The renal ecography was abnormal in 19,3% with a low sensitivity to detect parenchymal anomalies observed in DMSA scintigraphy: 12,5% as well as vesicoureteral reflux(VUR): 36%. DMSA renal scans demonstrated pathological results in 65% of the patients. The association of fever, leukocytosis >15.000/mm3 and positive C reactive protein was more frecuent with positive DMSA scans (44%) than in cases of negative DMSA (12%). In two patients with equivocal urine cultures DMSA scan allowed the diagnosis of acute pyelonephritis. The voiding cystourethrography showed VUR in 40,7% of the patients. This study couldn’t be performed in a high number of children (55%) because of lack of compliance. In consequence, this important pathology must be underdiagnosed and obliges to plan different strategies to detect it.

Chromosome 6q deletion: report of a new case and review of the literature

Os autores descrevem um novo caso de monossomia parcial do braço longo do cromossomo 6[46,XY,del(6)(q22 qter)]. A ocorrência de retardo psicomotor severo é esperada em funçäo do paciente apresentar um dos maiores segmentos deletados além da banda 6q25.