Vibrio cholerae O1 associated with recent endemic cholera shows temporal changes in serotype, genotype, and drug-resistance patterns in Bangladesh.

BACKGROUND: Despite the advancement in our understanding of cholera and its etiological agent, Vibrio cholerae, the prevention and treatment of the disease are often hindered due to rapid changes in drug response pattern, serotype, and the major genomic islands namely, the CTX-prophage, and related genetic characteristics. In the present study, V. cholerae (n = 172) associated with endemic cholera in Dhaka during the years 2015-2021 were analyzed for major phenotypic and genetic characteristics, including drug resistance patterns. RESULTS: Results revealed that the V. cholerae strains belonged to serogroup O1 biotype El Tor carrying El Tor -specific genes rtxC, tcpA El Tor, and hlyA El Tor, but possessed classical-biotype cholera toxin. Serotypes of V. cholerae strains differed temporally in predominance with Inaba during 2015-2017, and again in 2020-2021, while Ogawa was the predominant serotype in 2018-2019. Also, ctxB1 was predominant in V. cholerae associated with cholera during 2015-2017, while ctxB7 was predominant in 2018, and in the subsequent years, as observed until 2021. V. cholerae strains differed in their antibiotic resistance pattern with a majority (97%) being multi-drug resistant (MDR) and belonging to six sub-groups. Notably, one of these MDR strains was resistant to eleven of the eighteen antibiotics tested, with resistance to fourth-generation cephalosporin (cefepime), and aztreonam. This extreme drug resistant (XDR) strain carried resistance-related genes namely, extended-spectrum ß-lactamases (ESBL), blaOXA-1 and blaPER-3. CONCLUSION: The observed temporal switching of serotypes, as well as the ctxB genotype, and the emergence of MDR/XDR V. cholerae and their association with endemic cholera in Dhaka underscore the need for routine monitoring of the pathogen for proper patient management.

Fecal Sampling of Soil, Food, Hand, and Surface Samples from Households in Urban Slums of Dhaka, Bangladesh: An Evidence-Based Development of Baby Water, Sanitation, and Hygiene Interventions.

The aim of this study was to identify the exposure pathways of fecal pathogens for a pediatric population living in the urban slums of Bangladesh. A total of 252 soil, food, surface, and hand rinse samples were collected from the pilot households with children less than 5 years of age. All samples were analyzed using the IDEXX Quanti-Tray System (Colilert-18) to enumerate fecal indicator bacteria Escherichia coli. Escherichia coli was detected in all soil samples collected from children play spaces (N = 46), 35% of objects and surfaces children frequently put in their mouths, and 31% of child food samples. Thirty-three percent of hand samples from the child and 46% of hand samples from the caregiver had detectable E. coli. These findings showed high fecal contamination of soil, food, and on hands and surfaces in households with young children and demonstrate the need for interventions reducing these exposure pathways for susceptible pediatric populations.

Grewialin and optivanin new constituents from the stem bark of Grewia optiva Drummond ex Burret (Tiliaceae).

Studies on the chemical constituents from the stem bark of Grewia optiva have led to the isolation of two new compounds, grewialin (1) and optivanin (2), along with three known constituents which were hitherto unreported from this species. The structures of the new constituents have been elucidated by spectral studies including 1D and 2D NMR experiments (HSQC, HMBC, COSY, NOESY and J-resolved) as well as HR EI-MS spectroscopic data analysis, as 2S*-(3-hydroxy-4-methoxyphenyl)-3R*-methyl-2H-[1,4]-dioxin [2,3]-chromen-7(3H)-one (1); a coumarinolignan and 3-hydroxy-1-(3-hydroxy-4-methoxyphenyl) propan-1-one (2). The known compounds were identified as ß-sitosterol, stigmasterol and lupeol by comparing their spectral data with those reported in the literature.

Ethnic uses, pharmacological and phytochemical profile of genus Grewia.

A number of species of genus Grewia have been used as medicinal agents to treat several diseases. This review based on 45 literary sources discusses the current knowledge of traditional uses, chemistry, biological effects, and toxicity of different species of this genus. Triterpenoids, steroids, glycosides, flavones, lignans, phenolics, alkaloids, lactones, anthocyanins, flavones, and organic acids have been isolated from various species of this genus. The extracts and preparations from the various plants, which are expectantly safe, exhibited various biological effects, e.g. anti-oxidant, anti-bacterial, hepatoprotective, anti-inflammatory, anti-emetic, anti-malarial, analgesic, and anti-pyretic activities.