Uptake and depuration of three common antibiotics in benthic organisms: Sea cucumber (Holothuria tubulosa), snakelocks anemone (Anemonia sulcata) and beadlet anemone (Actinia equina).

Antibiotics are widely used drugs in human and veterinary medicine, which has attracted great attention in relation to the development of bacterial resistance, currently a problem of great concern for governments and states, as it is related to the resurgence of infectious diseases already eradicated. Understanding the bioaccumulation of antibiotics in aquatic organisms is an important key to understanding their risk assessment. The present study was designed to study the bioaccumulation of target antibiotics in relevant organisms inhabiting benthic marine environments. The uptake and elimination of ciprofloxacin (CIP), sulfamethoxazole (SMX) and trimethoprim (TMP) were investigated in sea cucumbers (Holothuria tubulosa), snakelock anemone (Anemonia sulcata) and beadlet anemone (Actinia equina) under controlled laboratory conditions. The results show that antibiotics have a particular trend over time during all periods of absorption and depuration. The tissue distribution of antibiotics in sea cucumber is strongly influenced by the structure of the compounds, while CIP is concentrated in the body wall; TMP is concentrated in the digestive tract. Two different approaches were used to estimate bioconcentration factors (BCFs) in different animal models, based on toxicokinetic data and measured steady-state concentrations. The BCF ranges were 456-2731 L/kg, 6-511 L/kg and 9-100 L/kg for TMP, CIP and SMX, respectively. The estimated BCF values obtained classify TMP as cumulative in A. equina and H. tubulosa, underlining the potential bioconcentration in these marine organisms. A correlation was observed between the BCFs of the target antibiotics and the octanol-water distribution coefficient (Dow) (r2 > 0.7). The animal-specific BCF followed the order of beadlet anemone > sea cucumber > snakelock anemone.

Bioconcentration of pharmaceuticals in benthic marine organisms (Holothuria tubulosa, Anemonia sulcata and Actinia equina) exposed to environmental contamination by atenolol and carbamazepine.

The present work assess the bioconcentration kinetics of atenolol (ATN) and carbamazepine (CBZ) in common marine organisms including Holothuria tubulosa, Anemonia sulcata and Actinia equina under controlled laboratory conditions. CBZ exhibited higher uptake and excretion rates resulting higher bioconcentration factor (BCF) (41-537 L/kg for CBZ vs 7-50 L/kg for ATN) although both are below the limits established by the European Union (EU). The measured BCF using kinetic data showed some differences with those predicted using the concentrations measured at the steady-state, probably explained because the steady state was not ready reached. The animal-specific BCF followed the order of Holothuria tubulosa > Actinia equina > Anemonia sulcata for ATN while was the opposite for CBZ. The study highlighted between-tissues differences in the digestive tract and the body wall of the Holothuria tubulosa. The work presented is the first to model bioconcentration of ATN and CBZ in holothurian and anemone animal models.

Accumulation and metabolization of the antidepressant venlafaxine and its main metabolite o-desmethylvenlafaxine in non-target marine organisms Holothuria tubulosa, Anemonia sulcata and Actinia equina.

The assessment of exposure to the antidepressant venlafaxine and its major metabolite o-desmethylvenlafaxine in Holothuria tubulosa, Anemonia sulcata and Actinia equina is proposed. A 28-day exposure experiment (10 µg/L day) followed by a 52-day depuration period was conducted. The accumulation shows a first-order kinetic process reaching an average concentration of 49,125/54342 ng/g dw in H. tubulosa and 64,810/93007 ng/g dw in A. sulcata. Venlafaxine is considered cumulative (BCF > 2000 L/kg dw) in H. tubulosa, A. sulcata and A. equina respectively; and o-desmethylvenlafaxine in A. sulcata. Organism-specific BCF generally followed the order A. sulcata > A. equina > H. tubulosa. The study revealed differences between tissues in metabolizing abilities in H. tubulosa this effect increases significantly with time in the digestive tract while it was negligible in the body wall. The results provide a description of venlafaxine and o-desmethylvenlafaxine accumulation in common and non-target organisms in the marine environment.

Determination of endocrine disrupting chemicals in human nails using an alkaline digestion prior to ultra-high performance liquid chromatography-tandem mass spectrometry.

Rapid industrialization has resulted in a progressive increase in human exposure to hazardous chemicals. The present work develops and validates a new method to determinate 18 endocrine disrupting chemicals (EDCs) in human nail samples. In contrast to other common biological samples, nail sampling is non-invasive and since they take several months to grow out, they are well suited for measuring and reflecting the cumulative exposure to harmful substances in the long term. A digestion of samples with a 0.04 M solution of sodium hydroxide is carried out followed by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), working in multiple-reaction-monitoring (MRM) mode. The compounds were separated in 8 min. Multivariate optimization strategies were used for the optimization of the parameters that affects the digestion procedure. The validation was developed using a matrix-matched calibration and a recovery assay with spiked samples. The limits of detection and quantification ranged from 0.3 to 1.2 ng g-1 and from 1 to 5 ng g-1, respectively. Recovery rates for spiked samples were between 88% and 113% and the relative standard deviation (% RSD) was lower than 12.7% for all studied EDCs. The method was applied for the analysis of these compounds in human nail samples from volunteers. All samples tested positive for several of the analyzed EDCs.

Assessing bioaccumulation potential of personal care, household and industrial products in a marine echinoderm (Holothuria tubulosa).

A bioaccumulation study of 16 emerging contaminants including preservatives, UV-filters, biocides, alkylphenols, anionic surfactants and plasticizers, in Holothuria tubulosa Gmelin, 1791 specimens was developed. Water and sediments from their coastal habitat were also analyzed. Sediment-water distribution coefficients (log Kd) were in the range 0.78 to 2.95. A rapid uptake and bioaccumulation of pollutants was found. Compounds were detected in intestine and gonads of H. tubulosa after only eight days of exposure. Field-based bioconcentration (BCF) and biota-sediment accumulation factors (BSAF) were calculated. Log BCF > 1 were obtained for most of the compounds studied, indicating their tendency to accumulate in tissue of H. Tubulosa. BCF values decrease as follow: Triclocarban > anionic surfactants > benzophenone 3 > non-ionic surfactants > bisphenol A > parabens. These data provide a detailed accounting of the distribution patterns of some emerging contaminants in organisms at the lower trophic level, representing a potential source of contaminants for organisms in higher levels of the food chain.

Bioaccumulation of perfluoroalkyl substances in marine echinoderms: Results of laboratory-scale experiments with Holothuria tubulosa Gmelin, 1791.

Bioaccumulation of six perfluoroalkyl substances (PFAS) was assessed using the marine echinoderm Holothuria tubulosa Gmelin, 1791. Batch experiments were conducted to establish the relationship between concentrations in water, sediment and biota over 197 days. The sample treatment for the determination of compounds involves steps of lyophilization, solvent extraction and clean-up of the extracts with dispersive sorbents. PFAS were then analysed by liquid chromatography-tandem mass spectrometry. During contaminant exposure, detectable levels of compounds were found in all samples collected. Mean concentrations of selected PFAS were higher in sediments than in water samples. This fact is explained by the strong adsorption of these compounds into sediments. Sediment-water distribution coefficients (log Kd) were in the range 0.11 (PFBuA) to 2.46 (PFOA). Beside this, PFAS accumulation was observed in Holothuria tubulosa organisms. The uptake of PFAS was very rapid, reaching the maximum between 22 and 38 days of assay. Bioaccumulation factors (mean log BAF: 1.16-4.39) and biota sediment accumulation factors (mean log BSAF: 1.37-2.89) indicated a high bioaccumulation potential for the target compounds. Both parameters increased with perfluoroalkyl chain length (R2 > 0.93; p < 0.05). In organ-specific distributions of PFAS, greater concentrations were found in intestine than in gonads. Also, male specimens showed higher concentration levels than female (student t-test: tcal = 2.788, ttab = 2.262; p < 0.05). These data provide a detailed accounting of PFAS fate and distribution in the marine environment highlighting accumulation at lower trophic levels, a potential source for contamination in higher organisms.

Valor pronóstico para pérdida ponderal excesiva en recién nacidos por cesárea en Cusco, Perú / Prognostic value of excessive weight loss in newborns delivered by caesarean section in Cusco, Peru

Introducción: La pérdida de peso en recién nacidos por cesárea es poco estudiada en Perú. Objetivo: Determinar el punto de corte de la variación de peso en las primeras 24 horas en recién nacidos a término por cesárea para desarrollar pérdida ponderal excesiva. Material y métodos: Se realizó un estudio analítico de prueba diagnóstica. La muestra estuvo conformada por 143 recién nacidos por cesárea sanos a término en Cusco-Perú. Se consideró como variable de interés a la pérdida ponderal excesiva (>10 por ciento) y como variable de exposición a la variación porcentual de peso a las 24 horas. Se establecieron puntos de corte para la pérdida ponderal excesiva por curvas ROC y validación diagnóstica. Resultados: El peso promedio al nacer fue 3262,7 gramos y la variación porcentual de peso a las 24 y 72 horas fue 4,9 por ciento y 8,6 por ciento respectivamente. El área bajo la curva en el grafico ROC fue 64,13 por ciento (IC95 por ciento; 54,03-74,22). El punto de corte para desarrollar pérdida ponderal excesiva a las 72 horas fue 5,47 por ciento (S: 51,28 por ciento; E: 69,23 por ciento; VPP: 38,46 por ciento y VPN: 79,12 por ciento). Por cada punto porcentual incrementado en la variación de peso a las 24 horas, el riesgo de tener pérdida ponderal excesiva se incrementó en 33 por ciento (OR: 1,33; IC95 por ciento 1,11-1,62; p=0,003). Conclusiones: La variación de peso en 5,47 por ciento a las 24 horas puede predecir una pérdida ponderal excesiva en recién nacidos por cesárea en Cusco-Perú(AU)

Introduction: Weight loss in newborns delivered by caesarean section is poorly studied in Peru. Objective: To determine the cut-off point for weight variation in the first 24 hours in term newborns delivered by caesarean section to develop excessive weight loss. Material and methods: An analytical study of diagnostic test was carried out. The sample was composed of 143 healthy babies born by cesarean section in Cusco, Peru. The excessive weight loss (> 10 percent was considered as a variable of interest and the percentage variation in weight at 24 hours was considered as a variable of exposure. Cut-off points were established for excessive weight loss due to ROC curves and diagnostic validation. Results: The average birth weight was 3262.7 grams and the percentage change in weight at 24 and 72 hours was 4.9 percent and 8.6 percent, respectively. The area under the ROC curve was 64.13 percent (95 percent CI; 54.03-74.22). The cut-off point to develop excessive weight loss at 72 hours was 5.47 percent (S: 51.28 percent; E: 69.23 percent; PPV: 38.46 percent and NPV: 79.12 percent). For each percentage point increase in weight change at 24 hours, the risk of having excessive weight loss increased by 33 percent (OR: 1.33; 95 percent CI; 1.11 - 1.62; p = 0.003). Conclusions: The variation in weight by 5.47 percent at 24 hours can predict excessive weight loss in newborns delivered by caesarean section in Cusco, Peru(AU)

[Antibiotic resistance of streptococcus pneumoniae among healthy nasopharyngeal carriers in seven regions of Peru]. / Resistencia antibiótica de streptococcus pneumoniae en portadores nasofaríngeos sanos de siete regiones del Perú

OBJECTIVES: To determine the pattern of antibiotic susceptibility of isolated Streptococcus pneumoniae strains of healthy nasopharyngeal carriers younger than 2 years in seven regions of Peru. MATERIALS AND METHODS: Between 2007 and 2009, nasopharyngeal swab samples were collected among 2123 healthy children aged 2-24 months in growth and development medical practices (CRED) and vaccination offices of hospitals and health centers in Lima, Piura, Cusco, Abancay, Arequipa, Huancayo, and Iquitos. The resistance to ten antibiotics through disk diffusion sensitivity testing of isolated pneumococcus strains was determined. RESULTS: 572 strains were isolated. High rates of resistance to co-trimoxazole (58%), penicillin (52.2% non-sensitive); tetracycline (29,1%); azithromycin (28,9%), and erythromycin (26,3%). Resistance to chloramphenicol was low (8.8%). Multiresistance was found at 29.5%. Resistance to azithromycin and penicillin was different in all seven regions (p<0,05), the highest percentage of non-sensitive strains being found in Arequipa (63,6%), whereas the lowest percentage was found in Cusco (23.4%). CONCLUSIONS: High levels of resistance found to penicillin, co-trimoxasole and macrolides in isolated pneumococcus strains of healthy carriers in all studied regions, and their association to a previous use of antibiotics, represent a significant public health problem in our country. This emphasizes the need to implement nationwide strategies to reduce the irrational use of antibiotics, especially among children. It is necessary to complement data of resistance to penicillin with the determination of minimal inhibitory concentration to make proper therapeutic recommendations.

[Pneumococcal serotypes in carrier children prior to the introduction of anti-pneumococcal vaccines in Peru]. / Serotipos de neumococo en niños portadores antes de la vacunación antineumocócica en el Perú.

OBJECTIVES: To determine the carriage rate and serotype distribution of Streptococcus pneumoniae in the nasopharynx of healthy children younger than 2 years prior to the universal use of the pneumococcal conjugate vaccines in Peru. MATERIALS AND METHODS: Between 2007 and 2009 we collected nasopharyngeal swab samples from 2,123 healthy children aged 2 to 24 months in the vaccination and healthy children consultation offices of pediatric hospitals and health centers in 7 cities in Peru: on the coast (Lima, Piura), highlands (Cusco, Abancay, Arequipa and Huancayo) and amazon basin (Iquitos). The pneumococcal strains were isolated and identified at the central laboratory of the project in Lima, and serotyped by Quellung reaction in the pneumococcal reference laboratory at the Center for Diseases Control and Prevention (CDC). RESULTS: We found 27% (573/2123) of pneumococcal nasopharyngeal healthy carrier children. Among the 526 analyzed strains, we found 42 serotypes; the most common were: 19F (18.1%), 6B (14.3%); 23F (8.9%) and 14 (6.5%). CONCLUSIONS: The distribution of vaccine serotypes in the analyzed strains was of 50% for the serotypes present in the seven-valent vaccine, 50.2% for the serotypes present in the ten-valent vaccine and 57.2% for those present in the thirteen-valent vaccine.