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A partial-nitritation bench-scale submerged biofilter was used for the treatment of synthetic wastewater containing a high concentration of ammonium in order to study the influence of the antibiotic ciprofloxacin on the partial-nitritation process and biodiversity of the bacterial community structure. The influence of ciprofloxacin was evaluated in four partial-nitritation bioreactors working in parallel, which received sterile synthetic wastewater amended with 350 ng/L of ciprofloxacin (Experiment 1), synthetic wastewater without ciprofloxacin (Experiment 2), synthetic wastewater amended with 100 ng/L of ciprofloxacin (Experiment 3) and synthetic wastewater amended with 350 ng/L of ciprofloxacin (Experiment 4). The concentration of 100 ng/L of antibiotics demonstrated that the partial-nitritation process, microbial biomass and bacterial structure generated by tag-pyrosequencing adapted progressively to the conditions in the bioreactor. However, high concentrations of ciprofloxacin (350 ng/L) induced a decay of the partial-nitritation process, while the total microbial biomass was increased. Within the same experiment, the bacterial community experienced sequential shifts with a clear reduction of the ammonium oxidation bacteria (AOB) and an evident increase of Commamonas sp., which have been previously reported to be ciprofloxacin-resistant. Our study suggests the need for careful monitoring of the concentration of antibiotics such as ciprofloxacin in partial-nitritation bioreactors, in order to choose and maintain the most appropriate conditions for the proper operation of the system.

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OBJECTIVES: To analyze the evolution of residual lithiasis after renal extracorporeal shock wave lithotripsy (ESWL) and to show the prolonged efficacy of thiazides in the treatment of residual lithiasis in patients with calcium lithiasis. METHODS: We performed a longitudinal, analytical, 36-month study in 100 patients with residual calcium lithiasis after ESWL randomly distributed into two groups: 50 patients treated with placebo (controls, group 1) and 50 treated with hydrochlorothiazide, 50 mg/24 hr (group 2). All patients in both groups underwent imaging studies (simple radiography of the urinary tract and renal ultrasonography) and a metabolic urinary study. RESULTS: The percentage of global expulsion of lithiasis during the follow-up period was significantly greater (chi-square exponent = 19.938, P = 0.001) in the patients treated with thiazides (72%) than in the control group (36%), although a large number of patients in this group underwent new ESWL sessions. During the follow-up period, we performed ESWL on 42% of the patients in group 1 and 18% of group 2, a statistically significant difference (chi-square exponent = 6.881, P = 0.032). CONCLUSIONS: The results of our study have shown that residual lithiasis progresses in 58% of patients undergoing observation, and new ESWL sessions will be necessary in 42%. We observed a significant relationship between the presence of a urinary lithogenic pattern and the progression of the residual lithiasis. The administration of thiazides stabilizes or reduces the growth of residual lithiasis and favors its spontaneous elimination, thus reducing the need for new sessions of ESWL. This effect of thiazides is highly significant in patients presenting with hypercalciuria.

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Objetivo: Demostrar la eficacia prolongada de las tiazidas en la profilaxis y tratamiento de las recidivas en pacientes con litiasis cálcica de oxalato y fosfato cálcico. Métodos: Se realiza un estudio prospectivo aleatorizado, con un seguimiento de tres años, en 150 pacientes diagnosticados de litiasis cálcica recidivante. Los pacientes se distribuyen en tres grupos: A) 50 casos sometidos a observación sin tratamiento, B) 50 casos tratados con 50 mg/día de hidroclorotiazida y C) 50 casos tratados con 50 mg de hidroclorotiazida y 20 mlEq de citrato potásico/día. En cada grupo se realiza estudio renal con técnicas de imagen, y estudio metabólico urinario basal, 12, 24 y 36 meses. Resultados: En los pacientes tratados con tiazidas (Grupo B y C) se obtiene una reducción significativa de recidiva litiásica en relación con el grupo control (Grupo A). La alteración más frecuente encontrada en el estudio metabólico fue hipercalciuria, 52% de los casos; el 16% presentan patrón litógeno mixto. El número de recidivas y necesidad de nuevas sesiones de litotricia extracorpórea en los pacientes con hipercalciuria tratados con tiazidas disminuye significativamente con respecto al Grupo A (p=0.003) Conclusiones: Se observa una relación significativa entre patrón litógeno y recidiva litiásica. Las tiazidas nos ayudan a controlar los factores litogénicos y las recidivas en pacientes con litiasis cálcica. Este efecto es prolongado y significativo en pacientes con hipercalciuria

Objective: To show the prolonged efficacy of thiazides in the prophylaxis and treatment of recurrences in patients with calcium oxalate and phosphate lithiasis. Methods: A randomised prospective study is conducted, with a three-year follow-up, in 150 patients diagnosed with recurrent calcium lithiasis. The patients are divided into three groups: A) 50 cases subject to observation with no treatment, B) 50 cases treated with 50 mg/day of hydrochlorothiazide, and C) 50 cases treated with 50 mg of hydrochlorothiazide and 20 mlEq of potassium citrate/day. Each group is subject to a renal study with imaging techniques and a urinary metabolic study at baseline, 12, 24 and 36 months. Results: The patients treated with thiazides (Groups B and C) obtain a significant reduction in lithiasis recurrence compared with the control group (Group A). The most common abnormality found in the metabolic study was hypercalciuria, 52% of cases; 16% present a mixed lithogenic pattern. The number of recurrences and need for new sessions of extracorporeal lithotripsy in patients with hypercalciuria treated with thiazides is significantly smaller than in Group A (p=0.003) Conclusions: We observe a significant relation between lithogenic pattern and lithiasis recurrence. Thiazides help us to control lithogenic factors and recurrences in patients with calcium lithiasis. This effect is prolonged and significant in patients with hypercalciuria

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OBJECTIVE: To analyze the role of thiazide therapy in the prevention of recurrent calcium nephrolithiasis, considering the hypocalciuric action of this drug. METHODS: A prospective study before and after treatment, with a 3-year follow-up, was carried out on 150 patients with recurrent calcium renal stone. The patients were divided into three groups: (A) no treatment, (B) treatment with thiazide 50 mg/day and (C) treatment with thiazide and potassium citrate. The treated groups were randomly assigned to the treatment arms. Control analytical tests and radiological assessments were performed regularly. RESULTS: Excellent results were achieved with thiazide therapy in regard to stone recurrence and changes in residual stone in comparison to the group of untreated patients (group A). The most common metabolic disorder was absorptive hypercalciuria type I. Most of the patients showed a single metabolic disorder. The side effects were generally not relevant. CONCLUSIONS: Thiazides should be considered as the first line of treatment in absorptive and excretory hypercalciuria. We believe that in unselected patients with calcium stone, thiazide therapy can be effective in its prevention. It is important to take into account the possible side effects of the drug and supplementation with potassium citrate for thiazide-induced hypocitraturia.

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