Determination of fecal indicator bacteria in shallow and deep groundwater sources of Kathmandu valley, Nepal

Groundwater is a crucial source of water for the residents of the Kathmandu valley, with an estimated 50% of total inhabitants dependent on groundwater supply for daily use. Hence, microbial evaluation of groundwater is a paramount exigency to evaluate the impact on public health of fecal contamination of the groundwater. The purpose of this study was to compare the distribution of fecal indicator bacteria in both shallow and deep groundwater sources of the Kathmandu valley as well as to evaluate their microbial quality. A total of nine groundwater sources within the Kathmandu valley including four shallow water sources and five deep-bore wells were sampled during the study period (May-July 2015) and tested for Escherichia coli and total coliforms by the most probable number (MPN) method using Colilert reagent (Idexx Laboratories). Coliform bacteria were detected in 100% (9/9) of the groundwater samples tested and E. coli was detected in 89% (8/9) of the samples tested. The occurrence of E. coli in the shallow groundwater sources was found to be 100% (4/4) and in the deep sources was 80% (4/5), with the average value ranging from 2 to 629.4 MPN/100 ml and 2419.6 MPN/100ml and 18.7 to 155.3 MPN/100ml. respectively. Deep groundwater sources were found to be comparatively less contaminated with fecal indicator bacteria compared to shallow groundwater sources. None of the groundwater samples analyzed met the drinking water quality standard recommended by World Health Organization, a finding which warrants the implementatioD. Bhandari, S. Tandukar, E. Haramoto, J.B. Sherchan

Long telomeres are associated with clonality in wild populations of the fissiparous starfish Coscinasterias tenuispina

7 páginas, 4 figuras, 3 tablasTelomeres usually shorten during an organism’s lifespan and have thus been used as an aging and health marker. When telomeres become sufficiently short, senescence is induced. The most common method of restoring telomere length is via telomerase reverse transcriptase activity, highly expressed during embryogenesis. However, although asexual reproduction from adult tissues has an important role in the life cycles of certain species, its effect on the aging and fitness of wild populations, as well as its implications for the long-term survival of populations with limited genetic variation, is largely unknown. Here we compare relative telomere length of 58 individuals from four populations of the asexually reproducing starfish Coscinasterias tenuispina. Additionally, 12 individuals were used to compare telomere lengths in regenerating and non-regenerating arms, in two different tissues (tube feet and pyloric cecum). The level of clonality was assessed by genotyping the populations based on 12 specific microsatellite loci and relative telomere length was measured via quantitative PCR. The results revealed significantly longer telomeres in Mediterranean populations than Atlantic ones as demonstrated by the Kruskal–Wallis test (K=24.17, significant value: P-valueo0.001), with the former also characterized by higher levels of clonality derived from asexual reproduction. Telomeres were furthermore significantly longer in regenerating arms than in non-regenerating arms within individuals (pyloric cecum tissue: Mann–Whitney test, V=299, P-valueo10− 6; and tube feet tissue Student's t= 2.28, P-value =0.029). Our study suggests that one of the mechanisms responsible for the long-term somatic maintenance and persistence of clonal populations is telomere elongation.This research was financially supported by a PhD fellowship FPI-MICINN (BES-2011-044154) (ACG), the European ASSEMBLY project (227799), the Swedish Royal Academy of Sciences (ACG) and the Spanish Government project CTM2010-22218-C02. The research was also supported by a ‘Juan de la Cierva’ contract from the Spanish Government (RPP) and by the Adlerbertska Research Foundation (HNS).Peer reviewe

Frecuencia de colonización por Estreptococo grupo B en embarazadas de 35 a 37 semanas en el Hospital Materno-Infantil San Pablo

La colonización del Estreptococo grupo B en la embarazada está relacionada a patologías perinatales, constituyéndose en una causa muy importante de morbi-mortalidad neonatal. De manera a reducir dicha morbi-mortalidad, el Centro de Control y Prevención de Enfermedades Infecciosas de Estados Unidos desarrolló una estrategia que consiste en realizar el cultivo de muestra tanto vaginal como ano-rectal de todas las mujeres entre 35 y 37 semanas de gestación. El objetivo de este trabajo fue determinar la frecuencia de colonización por Estreptococo β hemolítico grupo B en mujeres gestantes entre las 35-37 semanas de embarazo que concurrieron al Hospital Materno-Infantil San Pablo, Centro de Salud Nº 5, desde abril del 2010 a agosto del 2011. Se realizó un estudio con diseño observacional descriptivo de corte transverso. Las muestras fueron tomadas mediante hisopado de introito vaginal y ano-rectal, colocadas en medio de transporte Stuart y remitidas al Instituto de Investigaciones en Ciencias de la Salud para el cultivo en agar sangre, previo enriquecimiento en caldo Todd Hewitt. La identificación bacteriana se realizó mediante pruebas bioquímicas convencionales y la confirmación mediante aglutinación con látex. La frecuencia de colonización obtenida fue relativamente alta, de 23,6%. Los resultados de este estudio permiten dimensionar la problemática en nuestro país y evidenciar la necesidad de la implementación de un programa a nivel nacional para la detección del Estreptococo grupo B de forma rutinaria en las embarazadas. De esta manera, se podrá disminuir la morbi-mortalidad perinatal y materna con la administración oportuna del tratamiento profiláctico

Prevalence of Arcobacter and other pathogenic bacteria in river water in Nepal

Published: 10 July 2019This study aims to determine the diversity of pathogenic bacteria in the Bagmati River, Nepal, during a one-year period. A total of 18 river water samples were collected from three sites (n = 6 per site) along the river. Bacterial DNA, which were extracted from the water samples, were analyzed for bacterial 16S rRNA genes by next-generation sequencing for 13 of 18 samples, and by quantitative PCR targeting Arcobacter for all 18 samples. The 16S rRNA sequencing identified an average of 97,412 ± 35,909 sequences/sample, which were then categorized into 28 phyla, 61 classes, and 709 bacterial genera. Eighteen (16%) genera of 111 potential pathogenic bacteria were detected with abundance ratios of >1%; Arcobacter, Acinetobacter, and Prevotella were the dominant genera. The Arcobacter abundance ratios were 28.6% (n = 1), 31.3 ± 15.8% (n = 6), and 31.8 ± 17.2% (n = 6) at the upstream, midstream, and downstream sites, respectively. Arcobacter was detected in 14 (78%) of 18 samples tested, with concentrations ranging from 6.7 to 10.7 log10 copies/100 mL, based on quantitative PCR. Our results demonstrate the poor bacterial quality of the Bagmati River water, suggesting a need for implementing more measures to reduce fecal contamination in the river water.Rajani Ghaju Shrestha, Sarmila Tandukar, Dinesh Bhandari, Samendra P. Sherchan, Yasuhiro Tanaka, Jeevan B. Sherchand and Eiji Haramot

Detection of Cryptosporidium, Giardia, fecal indicator bacteria, and total bacteria in commercial jar water in Kathmandu Valley, Nepal

Introduction: Jar water is a convenient and common source of drinking water in the Kathmandu Valley. However, studies including detailed microbial analyses of this source of potable water are lacking. In this study, jar water samples were examined for the occurrence of Cryptosporidium, Giardia, fecal indicator bacteria, and total bacteria. Methods: Thirty different brands of jars were collected in September 2014. Escherichia coli and total coliforms w ere determined using a Colilert reagent. Ten of the 30 brands w ere selected to test for Cryptosporidium, Giardia, and total bacteria. Bacterial DNA extraction from water samples w as performed using the Cica Geneus DNA Extraction Kit, follow ed by quantitative polymerase chain reaction (qPCR) targeting the 16S rRNA gene of bacterial DNA. Protozoan detection was accomplished by concentrating the samples using the electronegative membrane vortex method, followed by immunomagnetic separation and fluorescent staining. Results: E. coli w as detected in 10% of the samples, with a maximum concentration of 2 most probable number (MPN)/100 mL, whereas total coliforms were detected in 97% of the samples, with a maximum and mean concentration of 7.3 × 10 2 and 3.8 × 10 1 MPN/100 mL, respectively. Total coliforms concentrations in 40% of the samples ranged from 10 2 to 10 3 MPN/100 mL. Cryptosporidium and Giardia w ere not detected in any of the tested samples. Concentrations of total bacteria in the samples ranged from 10 4 to 10 6 cells/100 mL. Conclusions: Ninety-seven percent of the jar water brands were unsuitable for drinking without proper treatment based on the guideline values of the National Drinking Water Quality Standards (NDW Q S) of Nepal. There is no guideline value for total bacteria in NDW Q S however, high concentrations can be indicative of poor control on regrowth of bacteria and recontamination or inefficient water treatment methods.Malla B, Ghaju Shrestha R, Bhandari D, Tandukar S, Shrestha S, Yoshinaga H, Inoue D, Sei K, Nishida K, Tanaka Y, Sherchand JB, Haramoto

Alelopatia de plantas de cobertura na superfície ou incorporadas ao solo no controle de Digitaria spp.

Os aleloquímicos podem sofrer modificações em diversos tipos de substrato, tanto incorporados quanto na superfície do solo. O objetivo deste estudo foi investigar os efeitos de diferentes níveis de palha de culturas de cobertura, quando incorporadas ou mantidas na superfície do solo, sobre a emergência e o desenvolvimento inicial de Digitaria spp. (milhã, capim-colchão e capim-de-roça). O delineamento experimental utilizado foi em bloco ao acaso, com quatro repetições. Os tratamentos foram arranjados em esquema fatorial com os seguintes fatores: (A) - manejo das coberturas (incorporado e na superfície do solo); (B) culturas de cobertura de solo (canola, nabo forrageiro, trevo-vesiculoso e azevém); e (C) níveis de palha (0, 1, 2, 4, 6 e 10 t ha-1). Com o aumento dos níveis de palha de canola e nabo forrageiro incorporados ao solo, há em geral aumento na redução das variáveis IVE e porcentagem de emergência de milhã. A presença de palha de azevém na superfície do solo reduz o crescimento de milhã, comparativamente à incorporação, sendo necessário ao menos 6 t ha-1 de palha.Allelochemicals can undergo changes in cover crops maintained on the soil surface or incorporated into soil. The objective of this study was to investigate the effect of different levels of cover crop straw, incorporated or not into soil, on the emergence and initial development of crabgrass (Digitaria spp.). The experiment was arranged in a randomized complete block design with 4 replications and treatments were arranged in a factorial scheme where: A)- management of cover crops (incorporated or not into the soil); B) - cover crops (Brassica napus, Raphanus sativus, Trifolium vesiculosum and Lolium multiflorum) and C) - straw levels (0, 1, 2, 4, 6 and 10 t ha-1). Increased straw levels of Brassica napus and Raphanus sativus incorporated into the soil leads to an increase in the reduction of the variables IVE and percentage of Digitaria spp. emergence. The presence of Lolium multiflorum straw on the soil surface reduces the growth of Digitaria spp., compared to incorporation into the soil, with at least 6 t ha-1 of straw being necessary