Seroprevalence of Angiostrongylus cantonensis in Wild Rodents from the Canary Islands

Background: Angiostrongylus cantonensis is a lungworm of rats (Muridae) that is the causative agent of human cerebral angiostrongyliasis. The life cycle of A. cantonensis involves rats and mollusks as the definitive and intermediate hosts, respectively. This study was designed to increase the knowledge about the occurrence and distribution of A. cantonensis in its definitive host in the Canary Islands, using parasitological and serological analysis in different areas and age groups.Methodology/Principal Findings: Between 2009 and 2010, 54 black rats (Rattus rattus) from Tenerife were captured from six human-inhabited areas and sera samples were obtained. The lung nematodes were identified by morphological and molecular tools as A. cantonensis. The 31-kDa glycoprotein antigen was purified from A. cantonensis adult worms by electrophoresis and electroelution. Of the 54 tested rodents, 30 showed IgG antibodies against A. cantonensis 31-kDa antigen by ELISA. Therefore, the overall seroprevalence was 55.6% (95% CI: 42.4-68). Seroprevalent rodents were found in all the 6 areas. This 31-kDa antigen was not recognized by some sera of rats infected by other helminth species (but not A. cantonensis). Seroprevalence of IgG antibodies against A. cantonensis and prevalence based on the presence of adult worms showed significant correlation (R2 = 0.954, p,0.05). Conclusions/Significance: The present results could indicate a high prevalence of A. cantonensisin Tenerife and suggest the inclusion of two new zones in the distribution area of the parasite. The commonness and wide distribution of A. cantonensis in rats implies the presence of intermediate hosts, indicating that humans may be at risk of getting infected

Efecto de la temperatura y tiempo de hidrólisis con NaOH en la obtención de péptidos solubles de harina de semillas residuales de tarwi (Lupinus mutabilis) variedad criolla.

                                                        Abstract The present investigation had as objective to evaluate the effect of the temperature and time of hydrolysis with NaOH in obtaining soluble peptides from the flour of seeds of Lupinus mutabilis, creole variety. The flour was previously deluphuptized, defatted and partially hydrolyzed with α-amylase (57º C, 208 min, pH: 5.5 and 0.01 g enzyme / kg substrate). The response surface method was used and a Rotable Central Compound Design (DCCR) was used, for two factors: Temperature and time. The initial characterization of the tarless meal showed a high content of protein (43.53 ± 0.04 g /100 g), lipids (25.41 ± 0.03 g /100 g) and ash (1.40 ± 0.07 g/100 g). The alkaline hydrolysis with NaOH was performed at pH 10, 1/25 flour: solvent ratio, time between 10 to 90 minutes and temperature between 25 ° C - 50 ° C. The quantification of the peptides was carried out by the Lowry method. The results obtained indicated that the highest concentration of soluble peptides was 7,204 mg / ml, which presented treatment at 46.3°C for 78 minutes. The mathematical model that allows predicting the concentration of soluble peptides is: Y = -7.8711 + 0.5574*X1 - 0.0084*X12 - 0.0008*X22 + 0.0032*X1*X2.; where Y is the concentration of soluble peptides in mg / mL, X1 the temperature (° C) and X2: time (minutes). Statistical analysis showed that there is a high significance value of the independent variables (time and temperature) with respect to the response variable (soluble peptides) (p <0.05).Resumen La presente investigación tuvo como objetivo evaluar el efecto de la temperatura y tiempo de hidrólisis con NaOH en la obtención de péptidos solubles de harina de semillas de Lupinus mutabilis, variedad criolla. La harina fue previamente deslupinizada, desgrasada e hidrolizada parcialmente con α-amilasa.  Se utilizó el método de superficie de respuesta y se empleó un Diseño Compuesto Central Rotable (DCCR), para dos factores: temperatura y tiempo. La caracterización inicial de la harina deslupinizada mostró un alto contenido de proteína (43.53 ± 0.04 g/ 100 g), lípidos (25.41 ± 0.03 g/100 g) y cenizas (1.40 ± 0.07 g /100 g). La hidrólisis alcalina con NaOH se realizó a pH 10, relación harina/solvente 1/25, tiempo entre 10 a 90 minutos y temperatura entre 25 °C – 50 °C. La cuantificación de los péptidos se realizó por el método de Lowry. Los resultados obtenidos indicaron que la mayor concentración de péptidos solubles fue de 7.204 mg/ml que presentó el tratamiento a 46.3 °C por 78 minutos. El modelo matemático que permite predecir la concentración de péptidos solubles es: Y = -7.8711 + 0.5574*X1 - 0.0084*X12 - 0.0008*X22 + 0.0032*X1*X2; donde Y es la concentración de péptidos solubles en mg/ml, X1 la temperatura (°C) y X2: tiempo (minutos). El análisis estadístico mostró que existe un alto valor de significancia de las variables independientes (tiempo y temperatura) con respecto a la variable respuesta (péptidos solubles) (p<0.05)

A Peculiar Distribution of the Emerging Nematode Angiostrongylus cantonensis in the Canary Islands (Spain): Recent Introduction or Isolation Effect?

Angiostrongylus cantonensis is an emerging zoonotic nematode recognized as the leading cause of eosinophilic meningitis in the word. After its discovery in China, it was recorded in 30 countries worldwide. Recently, it has expanded to new areas such as South America and it has been recently found in the Atlantic island of Tenerife (Canary Islands). In order to characterize the distribution of A. cantonensis in the Canary Islands, the lungs of 1462 rodents were sampled in eight islands of the archipelago over 13 years and were then analyzed for A. cantonensis. Remarkably, the parasite was detected only in Tenerife, in Rattus rattus (19.7%) and Rattus norvegicus (7.14%). They were concretely in the northern part of the island, which had a warmer and more humid climate than the south and main cities. The absence of this nematode in other islands with similar environmental conditions could be explained by an isolation effect or by a recent introduction of the parasite in the islands. Besides, the presence in Tenerife of the most invasive lineage of A. cantonensis reinforced the hypothesis of a recent introduction on this island. This study highlights the need to implement control measures to prevent the expansion to other areas in order to avoid the transmission to humans and other animals

Seroprevalence of Angiostrongylus cantonensis in wild rodents from the Canary Islands

Background: Angiostrongylus cantonensis is a lungworm of rats (Muridae) that is the causative agent of human cerebral angiostrongyliasis. The life cycle of A. cantonensis involves rats and mollusks as the definitive and intermediate hosts, respectively. This study was designed to increase the knowledge about the occurrence and distribution of A. cantonensis in its definitive host in the Canary Islands, using parasitological and serological analysis in different areas and age groups.Methodology/Principal Findings: Between 2009 and 2010, 54 black rats (Rattus rattus) from Tenerife were captured from six human-inhabited areas and sera samples were obtained. The lung nematodes were identified by morphological and molecular tools as A. cantonensis. The 31-kDa glycoprotein antigen was purified from A. cantonensis adult worms by electrophoresis and electroelution. Of the 54 tested rodents, 30 showed IgG antibodies against A. cantonensis 31-kDa antigen by ELISA. Therefore, the overall seroprevalence was 55.6% (95% CI: 42.4-68). Seroprevalent rodents were found in all the 6 areas. This 31-kDa antigen was not recognized by some sera of rats infected by other helminth species (but not A. cantonensis). Seroprevalence of IgG antibodies against A. cantonensis and prevalence based on the presence of adult worms showed significant correlation (R2 = 0.954, p,0.05). Conclusions/Significance: The present results could indicate a high prevalence of A. cantonensisin Tenerife and suggest the inclusion of two new zones in the distribution area of the parasite. The commonness and wide distribution of A. cantonensis in rats implies the presence of intermediate hosts, indicating that humans may be at risk of getting infected

Intermediate-Salinity Systems at High Altitudes in the Peruvian Andes Unveil a High Diversity and Abundance of Bacteria and Viruses

Intermediate-salinity environments are distributed around the world. Here, we present a snapshot characterization of two Peruvian thalassohaline environments at high altitude, Maras and Acos, which provide an excellent opportunity to increase our understanding of these ecosystems. The main goal of this study was to assess the structure and functional diversity of the communities of microorganisms in an intermediate-salinity environment, and we used a metagenomic shotgun approach for this analysis. These Andean hypersaline systems exhibited high bacterial diversity and abundance of the phyla Proteobacteria, Bacteroidetes, Balneolaeota, and Actinobacteria; in contrast, Archaea from the phyla Euryarchaeota, Thaumarchaeota, and Crenarchaeota were identified in low abundance. Acos harbored a more diverse prokaryotic community and a higher number of unique species compared with Maras. In addition, we obtained the draft genomes of two bacteria, Halomonas elongata and Idiomarina loihiensis, as well as the viral genomes of Enterobacteria lambda-like phage and Halomonas elongata-like phage and 27 partial novel viral halophilic genomes. The functional metagenome annotation showed a high abundance of sequences associated with detoxification, DNA repair, cell wall and capsule formation, and nucleotide metabolism; sequences for these functions were overexpressed mainly in bacteria and also in some archaea and viruses. Thus, their metabolic profiles afford a decrease in oxidative stress as well as the assimilation of nitrogen, a critical energy source for survival. Our work represents the first microbial characterization of a community structure in samples collected from Peruvian hypersaline systems