Impacts of cyclone and flood on crop and fish production in disaster prone coastal Bhola district of Bangladesh

This study assessed the impact of climate change induced disaster on crops and fisheries production at Bhola Sadar and Monpura upazila of Bhola district, Bangladesh during January to June 2018. The study was gathered primary data from primary observation (PO), questionnaire survey (QS), focus group discussion (FGD), and key informant interview (KII). Secondary data were collected from Upazila Agricultural Office and Upazila Fisheries Office of Bhola Sadar and Manpura upazila and moreover, climatic data were collected from Bangladesh Meteorological Department. Results of the study found that trend analysis indicates overall annual maximum temperature increased for Kharif-I, Kharif-II and Rabi season. Average annual minimum temperature also increased for Kharif-I season but decreased for Kharif-II and Rabi season. Study also found that for all cropping season average relative humidity was increased. Annual average rainfall exhibited decreasing trend for Kharif-I and Rabi season but increased for Kharif-II season in (1990-2019) time period. The Aus, T. Aman, Boro and Mung bean was dominant cropping pattern in Kharif-I, Kharif- II and Rabi season in Bhola district. Overall, Aus rice production in Kharif-I season increased but in 2009, 2013 production was decreased because of cyclone Aila (2009) and Cyclone Mahasen (2013). T. Aman production hampered due to Cyclone Sidr (2007) and flood (2014) in Kharif-II season. In Rabi season Boro rice production lessen because of low rainfall and salinity intrusion. Overall, Mung bean production increase but in 2008 and 2009 production become hampered due to late cultivation because of Cyclone Sidr (2007). Fish production rate increase in Bhola specially Hilsha fish because of non-climatic factor like raid in non-fishing time, banned current net but fish production in pond become diminished due to infrequent natural disaster. Practicing of salt and flood tolerant varieties, floating bed vegetable cultivation, and mixed cropping system (mainly for Rabi season), enhanced expedition activities against catching mother Ilish in prohibition period, dredging in the heart of the river which can eventually reduce vulnerabilities and increase crop and fish production in the Bhola region. Int. J. Agril. Res. Innov. Tech. 10(1): 40-55, June 202

Impacts of cyclone and flood on crop and fish production in disaster prone coastal Bhola district of Bangladesh

This study assessed the impact of climate change induced disaster on crops and fisheries production at Bhola Sadar and Monpura upazila of Bhola district, Bangladesh during January to June 2018. The study was gathered primary data from primary observation (PO), questionnaire survey (QS), focus group discussion (FGD), and key informant interview (KII). Secondary data were collected from Upazila Agricultural Office and Upazila Fisheries Office of Bhola Sadar and Manpura upazila and moreover, climatic data were collected from Bangladesh Meteorological Department. Results of the study found that trend analysis indicates overall annual maximum temperature increased for Kharif-I, Kharif-II and Rabi season. Average annual minimum temperature also increased for Kharif-I season but decreased for Kharif-II and Rabi season. Study also found that for all cropping season average relative humidity was increased. Annual average rainfall exhibited decreasing trend for Kharif-I and Rabi season but increased for Kharif-II season in (1990-2019) time period. The Aus, T. Aman, Boro and Mung bean was dominant cropping pattern in Kharif-I, Kharif-II and Rabi season in Bhola district. Overall, Aus rice production in Kharif-I season increased but in 2009, 2013 production was decreased because of cyclone Aila (2009) and Cyclone Mahasen (2013). T. Aman production hampered due to Cyclone Sidr (2007) and flood (2014) in Kharif-II season. In Rabi season Boro rice production lessen because of low rainfall and salinity intrusion. Overall, Mung bean production increase but in 2008 and 2009 production become hampered due to late cultivation because of Cyclone Sidr (2007). Fish production rate increase in Bhola specially Hilsha fish because of non-climatic factor like raid in non-fishing time, banned current net but fish production in pond become diminished due to infrequent natural disaster. Practicing of salt and flood tolerant varieties, floating bed vegetable cultivation, and mixed cropping system (mainly for Rabi season), enhanced expedition activities against catching mother Ilish in prohibition period, dredging in the heart of the river which can eventually reduce vulnerabilities and increase crop and fish production in the Bhola region

Shigella flexneri utilizes intestinal signals to control its virulence

ABSTRACTThe enteric pathogens have evolved to utilize elements from their surroundings to optimize their infection strategies. A common mechanism to achieve this is to employ intestinal compounds as signals to control the activity of a master regulator of virulence. Shigella flexneri (S. flexneri) is a highly infectious entero-invasive pathogen which requires very few organisms to cause invasion of the colonic mucosa. The invasion program is controlled by the virulence master regulator VirF. Here, we show that the fatty acids commonly found in the colon can be exploited by S. flexneri to repress its virulence, allowing it to energetically finance its proliferation, thus increasing its pathogenicity. Colonic fatty acids such as oleic, palmitoleic and cis-2-hexadecenoic acid were shown to directly bind to VirF and mediate its prompt degradation. These fatty acids also disrupted the ability of VirF to bind to its target DNA, suppressing the transcription of the downstream virulence genes and significantly reducing the invasion of S. flexneri to colonic epithelial cells. Treatment with colonic fatty acids significantly increased the growth rate of the pathogen only under invasion-inducing conditions, showing that the reduction in the burden of virulence promotes a growth advantage. These results demonstrate the process by which S. flexneri can employ intestinal compounds as signals to increase its numbers at its preferred site of invasion, highlighting the mechanism by which the full spectrum of shigellosis is achieved despite a miniscule infectious dose. This highlights an elegant model of environmental adaption by S. flexneri to maximize the pathogenic benefit

Data from: Recombinant production of a diffusible signal factor inhibits Salmonella invasion and animal carriage

Please cite as: Mudasir Ali Rather, Rimi Chowdhury, Paulina Pavinski Bitar, Craig Altier. (2023) Data from: Recombinant production of a diffusible signal factor inhibits Salmonella invasion and animal carriage. [dataset] Cornell University eCommons Repository. https://doi.org/10.7298/gv1c-b060These files contain data along with associated output from instrumentation supporting all results reported in Rather, et al. In Rather, et al., we found: The complex chemical environment of the intestine is defined largely by the metabolic products of the resident microbiota. Enteric pathogens, elegantly evolved to thrive in the gut, use these chemical products as signals to recognize specific niches and to promote their survival and virulence. Our previous work has shown that a specific class of quorum-sensing molecules found within the gut, termed diffusible signal factors (DSF), signals the repression of Salmonella tissue invasion, thus defining a means by which this pathogen recognizes its location and modulates virulence to optimize its survival. Here we determined whether the recombinant production of a DSF could reduce Salmonella virulence in vitro and in vivo. We found that the most potent repressor of Salmonella invasion, cis-2-hexadecenoic acid (c2-HDA), could be recombinantly produced in E. coli by the addition of a single exogenous gene encoding a fatty acid enoyl-CoA dehydratase/thioesterase, and that co-culture of the recombinant strain with Salmonella potently inhibited tissue invasion by repressing Salmonella genes required for this essential virulence function. Using the well characterized E. coli Nissle 1917 strain and a chicken infection model, we found that the recombinant DSF-producing strain could be stably maintained in the large intestine. Further, challenge studies demonstrated that this recombinant organism could significantly reduce Salmonella colonization of the cecum, the site of carriage in this animal species. These findings thus describe a plausible means by which Salmonella virulence may be affected in animals by in situ chemical manipulation of functions essential for colonization and virulence.This project was supported by Agriculture and Food Research Initiative Competitive Grant no. 2021-08162 from the USDA National Institute of Food and Agriculture, and by NIH/NIAID grant R01 AI162944-01 to C.A

Salmonella Invasion Is Controlled by Competition among Intestinal Chemical Signals

ABSTRACT The intestine is a complex, ever-changing environment replete with an array of signaling molecules. To colonize such a complex organ, pathogens have adapted to utilize specific cues from the local environment to intricately regulate the expression of their virulence determinants. Salmonella preferentially colonizes the distal ileum, a niche enriched in the metabolite formic acid. Here, we show that the relatively higher concentration of this metabolite in the distal ileum prevents other signals from repressing Salmonella invasion in that region. We show that imported and unmetabolized formic acid functions as a cytoplasmic signal that competitively binds to HilD, the master transcriptional regulator of Salmonella invasion, thus preventing repressive fatty acids from binding to the protein. This results in an increased lifetime of HilD and subsequent derepression of invasion genes. This study demonstrates an important mechanism by which Salmonella utilizes competition among signals in the gut to its advantage as a pathogen. IMPORTANCE Enteric pathogens acutely sense their environment for signals to regulate their virulence functions. We demonstrate here that the enteric pathogen Salmonella utilizes the competition among certain regional intestinal constituents to modulate its virulence determinants in that region. We show that the high concentration of formic acid in the ileum outcompetes other signals and triggers the activation of virulence genes in the ileum. This study shows a delicate spatial and temporal mechanism by which enteric pathogens may utilize the competition among environmental cues to optimize their pathogenicity

Recombinant production of a diffusible signal factor inhibits Salmonella invasion and animal carriage

ABSTRACTThe complex chemical environment of the intestine is defined largely by the metabolic products of the resident microbiota. Enteric pathogens, elegantly evolved to thrive in the gut, use these chemical products as signals to recognize specific niches and to promote their survival and virulence. Our previous work has shown that a specific class of quorum-sensing molecules found within the gut, termed diffusible signal factors (DSF), signals the repression of Salmonella tissue invasion, thus defining a means by which this pathogen recognizes its location and modulates virulence to optimize its survival. Here, we determined whether the recombinant production of a DSF could reduce Salmonella virulence in vitro and in vivo. We found that the most potent repressor of Salmonella invasion, cis-2-hexadecenoic acid (c2-HDA), could be recombinantly produced in E. coli by the addition of a single exogenous gene encoding a fatty acid enoyl-CoA dehydratase/thioesterase and that co-culture of the recombinant strain with Salmonella potently inhibited tissue invasion by repressing Salmonella genes required for this essential virulence function. Using the well characterized E. coli Nissle 1917 strain and a chicken infection model, we found that the recombinant DSF-producing strain could be stably maintained in the large intestine. Further, challenge studies demonstrated that this recombinant organism could significantly reduce Salmonella colonization of the cecum, the site of carriage in this animal species. These findings thus describe a plausible means by which Salmonella virulence may be affected in animals by in situ chemical manipulation of functions essential for colonization and virulence

A diffusible signal factor of the intestine dictates Salmonella invasion through its direct control of the virulence activator HilD.

Successful intestinal infection by Salmonella requires optimized invasion of the gut epithelium, a function that is energetically costly. Salmonella have therefore evolved to intricately regulate the expression of their virulence determinants by utilizing specific environmental cues. Here we show that a powerful repressor of Salmonella invasion, a cis-2 unsaturated long chain fatty acid, is present in the murine large intestine. Originally identified in Xylella fastidiosa as a diffusible signal factor for quorum sensing, this fatty acid directly interacts with HilD, the master transcriptional regulator of Salmonella, and prevents hilA activation, thus inhibiting Salmonella invasion. We further identify the fatty acid binding region of HilD and show it to be selective and biased in favour of signal factors with a cis-2 unsaturation over other intestinal fatty acids. Single mutation of specific HilD amino acids to alanine prevented fatty acid binding, thereby alleviating their repressive effect on invasion. Together, these results highlight an exceedingly sensitive mechanism used by Salmonella to colonize its host by detecting and exploiting specific molecules present within the complex intestinal environment

Hand hygiene infrastructure and behaviours in resource-limited healthcare facilities

This paper was accepted for publication in the journal Journal of Hospital Infection and the definitive published version is available at http://dx.doi.org/10.1016/j.jhin.2016.08.01

Antibacterial Nanofibrous Mat of Pullulan/Cinnamaldehyde-Cyclodextrin Inclusion Complexes as a Potential Cloth Mask Layer with Long-Term Storage Stability and Facile Disposal Property

There is an ongoing rise in global plastic waste because of the mass production and vast consumption of surgical face masks during the COVID-19 outbreak. This problem leads to a crucial need for alternative face coverings which can eliminate environmental concerns. Using cloth masks can be a sustainable solution if combined with a functional filtering layer. In this study, electrospun nanofibrous mats (NM) were generated using a renewable biopolymer; pullulan by the incorporation of cyclodextrin inclusion complexes (γCD-IC) of naturally occurring essential oil compound; trans-cinnamaldehyde (CAH). Pullulan/CAH-γCD-IC NM was readily inserted into a cloth mask due to its free-standing and foldable features and achieved higher loading efficiency (∼62%) than pullulan/CAH NM (∼10%). Here, pullulan/CAH-γCD-IC NM showed substantial and better antibacterial activity, long-term storage stability, and thermal stability due to inclusion complexation. Pullulan/CAH-γCD-IC NM was also obtained with promising properties of pore size (∼390 nm) and water vapor permeability (∼890 g/m2/day). The water solubility of pullulan/CAH-γCD-IC NM ensured fast and easy disposal without potential environmental loading, thanks to the biocompatibility of components. Briefly, pullulan/CAH-γCD-IC NM can create an attractive alternative as a functional layer that can be combined with the cloth mask

Antibacterial Nanofibrous Mat of Pullulan/Cinnamaldehyde-Cyclodextrin Inclusion Complexes as a Potential Cloth Mask Layer with Long-Term Storage Stability and Facile Disposal Property

There is an ongoing rise in global plastic waste because of the mass production and vast consumption of surgical face masks during the COVID-19 outbreak. This problem leads to a crucial need for alternative face coverings which can eliminate environmental concerns. Using cloth masks can be a sustainable solution if combined with a functional filtering layer. In this study, electrospun nanofibrous mats (NM) were generated using a renewable biopolymer; pullulan by the incorporation of cyclodextrin inclusion complexes (γCD-IC) of naturally occurring essential oil compound; trans-cinnamaldehyde (CAH). Pullulan/CAH-γCD-IC NM was readily inserted into a cloth mask due to its free-standing and foldable features and achieved higher loading efficiency (∼62%) than pullulan/CAH NM (∼10%). Here, pullulan/CAH-γCD-IC NM showed substantial and better antibacterial activity, long-term storage stability, and thermal stability due to inclusion complexation. Pullulan/CAH-γCD-IC NM was also obtained with promising properties of pore size (∼390 nm) and water vapor permeability (∼890 g/m2/day). The water solubility of pullulan/CAH-γCD-IC NM ensured fast and easy disposal without potential environmental loading, thanks to the biocompatibility of components. Briefly, pullulan/CAH-γCD-IC NM can create an attractive alternative as a functional layer that can be combined with the cloth mask