Alterations in the transcriptional landscape allows differential desiccation tolerance in different strains of Cronobacter sakazakii

Cronobacter sakazakii is a typical example of a xerotolerant bacterium. It is epidemiologically linked to low moisture foods like powdered infant formula (PIF) and is associated with high fatality rates among neonates. We characterized the xerotolerance in a clinically isolated strain, C. sakazakii ATCC™29544 T , and compared the desiccation tolerance with an environmental strain, C. sakazakii SP291, whose desiccation tolerance was previously characterized. We found that, although the clinical strain was desiccation-tolerant, the level of tolerance was compromised when compared to the environmental strain. RNA-seq based deep transcriptomic characterization identified a unique transcriptional profile in the clinical strain compared to what was already known for the environmental strain. As RNA-seq was also carried out in different TSB growth conditions, genes that were expressed specifically under desiccated conditions were identified and denoted as desiccation responsive genes (DRGs). Interestingly, these DRGs included transcriptomic factors like fnr , ramA, and genes associated with inositol metabolism, a phenotype as yet unreported in C. sakazakii . Further, the clinical strain did not express the proP gene, which was previously reported to be very important for desiccation survival and persistence. Interestingly, analysis of the plasmid genes showed that the iron metabolism in desiccated C. sakazakii ATCC™29544 T cells specifically involved the siderophore cronobactin encoded by the iucABCD genes. Confirmatory studies using qRT-PCR determined that, though the secondary desiccation response genes were upregulated in C. sakazakii ATCC™29544 T , the level of up-regulation was lower compared to that in C. sakazakii SP291. All these factors could collectively contribute to the compromised desiccation tolerance in the clinical strain. IMPORTANCE Cronobacter sakazakii has in past led to outbreaks, particularly associated with food that are low in moisture content. This species has adapted to survive in low water conditions and can survive in such environments for long periods. These characteristics have enabled the pathogen to contaminate powder infant formula, a food matrix with which the pathogen has been epidemiologically associated. Even though clinically adapted strains can also be isolated, there is no information on how the clinical strains adapt to low moisture environments. Our research assessed the adaptation of a clinically isolated strain to low moisture survival on sterile stainless steel coupons and compared the survival to a highly desiccation-tolerant environmental strain. We found that, even though the clinical strain is desiccation-tolerant, the rate of tolerance was compromised compared to the environmental strain. A deeper investigation using RNA-seq identified that the clinical strain used pathways different from that of the environmental strain to adapt to low moisture conditions. This shows that the adaptation to desiccation conditions, at least for C. sakazakii , is strain-specific and that different strains have used different evolutionary strategies for adaptation.

Genetic Relationship of Transcriptional Factor Genes in the Regulation of Cells Death in Arabidopsis: A Review

The leaf yellowing is the first visible sign of senescence, which starts at the margins of the leaf and progresses to the blade. Although, transcriptional factor family genes generally encode meticulous regulators which perform a range of functions in turns regulating the physiological and developmental mechanism of plant stature. However, the genetic relationship of TFs genes in regulating the cell death of Arabidopsis is well not understood to date. TFs family in a plant regulates various developmental and stress responses in underline pathways. In our review we observed the genetic relationship of TFs genes in regulations of cell death in Arabidopsis. Given that, programmed cell death (PCD) being an active process that includes the expression of hundreds of genes. It is speculated that many TFs are involved in the core elements of the regulatory network. There are only a few factors that are being demonstrated in involving the regulation of cell death, by evaluating the leaf senescence appearances of knocking of mutants and by identifying downstream target genes. In this review, we have focused on the manifold roles of TFs during genetic relationships and the regulation of cell death in Arabidopsis. We also deliberated how the transcription factors family gene regulates the cells’ death by different hormonal stress, environmental strain and their role in retrograde signaling. For deep understanding of regulatory molecular mechanisms of cell death in the plant, future research may be hypothesized to collect appropriate evidence and a detailed study may be implemented on the upstream pathway with a specific targeted gene that recognizes the stress signals involved in cell death in plants. Also, crosstalk between mitochondria and chloroplast is mainly being focused to better understand the regulations of cell death in plants. Present review concludes that regulating the cell death of Arabidopsis is very important for meeting future global food needs, crop yields. Overexpression of ERF transcription factors genes relating cell death of Arabidopsis confers broad-spectrum resistance to pathogens and other abiotic stresses and can also make transgenic plants resistant to drought, salinity and freezing.

Anthropogenic and Environmental Strain on Beach Environments Retrieved and Monitored by Spaceborne Synthetic Aperture Radar

Environmental effects and climate change are lately representing an increasing strain of the coastal areas which topography strongly depends on these conditions. However, the processes by which weather and environmental phenomena influence the highly variable beach morphology are still unknown. A continuous monitoring of the beach environment is necessary to implement protection strategies. This paper presents the results of an innovative study performed on a coastal area using satellite remote sensing data with the aim of understanding how environmental phenomena affect beaches. Two-years of synthetic aperture radar (SAR) Sentinel-1 images are used over a test area in Noordwijk, the Netherlands. At the same time as the SAR acquisitions, information on tidal and weather conditions are collected and integrated from nearby meteorological stations. Dedicated codes are implemented in order to understand the relationship between the SAR amplitude and the considered phenomena: wind, precipitation, tidal conditions. Surface roughness is taken into account. The results indicate a strong correlation between the amplitude and the wind. No particular correlation or trend could be noticed in the relation with the precipitation. The analysis of the amplitude also shows a decreasing trend moving from the dry area of the beach towards the sea and the correlation coefficient between the amplitude and the tide level gets negative with the increase of the water content.

Oral immunization of Escherichia albertii strain DM104 induces protective immunity against Shigella dysenteriae type 4 in mouse model

The recent rise of antibiotic resistance and lack of an effective vaccine make the scenario of shigellosis alarming in developing countries like Bangladesh. In recent years, our group reported the vaccine efficacy of a non-pathogenic Escherichia albertii strain DM104 in different animal models, where an ocularly administered vaccine in the guinea pig eye model against Shigella dysenteriae type 4 challenge showed high protective efficacy and also induced a high titer of serum IgG against S. dysenteriae type 4 whole cell lysate (WCL) and LPS. In this study, we report further evaluation of the non-invasive and non-toxic environmental strain DM104 as a vaccine candidate against S. dysenteriae type 4 in mice model. Oral immunization of live DM104 bacterial strain demonstrated better protective immunity in mice model by showing 90% protection in mice against live S. dysenteriae type 4 lethal dose challenge and by inducing effective humoral and mucosal immune responses.

Fungicidal Activity of Five Disinfectants on Isolates of Candida Species

Determine fungicidal activity of five disinfectants on Candida auris of clinical and environmental origin. Assess fungicidal efficiency of each disinfectants on the microorganism. Calculate percentage of efficiency (% E) of each disinfectants on Candida strain and determine specific death rate (k) and decimal reduction time for the microorganism. An analytic and experimental research with quantitative methods. We realized a strains workbench by culturing it in corresponding culture media. Analysis was a challenge essay, performed on four surfaces and at different exposure times; 1, 5, 15 and 30 minutes of contact between disinfectant and yeast. Once disinfection process was carried out, what was expected was that after 15 minutes of contact between the yeasts and the disinfectants, a percentage of inhibition of the microorganism between 90 and 95% was presented, thus guaranteeing the duration of elimination of the infectious agent by disinfectants. Results shows that after one minute of contact between Candida auris and the disinfectant in a gloved hand, there was a removal of the yeast, when the clinical and environmental strain were analyzed. Data showing disinfectants efficiency percentages greater than 90% over strains of Candida used in the study. Decimal reduction times in seconds of the strains of Candida against the disinfectants used in the study were between 9.3 and 14.04 s. It was possible to evaluate effectiveness by means inhibition percentage of each disinfectants on the strains of Candida auris of clinical and environmental origin. Similarly, specific death rate and decimal reduction time in seconds were determined for strains under study.

Reduction of hazardous incinerated bio-medical waste ash and its environmental strain by utilizing in green concrete

Incinerated Bio-Medical Waste Ash (IBWA) is toxic waste material with broad potential (cancer, genetic risk, premature death, permanent disease) to inflict severe health damage for the atmosphere and humans. This waste is disposed of as landfills which contaminate the underground water and environment. The effective way of disposal of IBWA is by utilizing it as a building material which can reduce the hazardous toxic materials. The use of Geopolymer Concrete (GPC) combined with IBWA as a substitute for Ground Granulated Blast Furnace Slag (GGBS) has been researched for its ability to create a new type of Green Concrete. The physical and chemical properties were observed for the raw materials. IBWA was used at 0, 5, 10, 15, 20, 25, 30, 35, 40, 45 and 50% replacement by weight for GGBS. Mixing proportions were 1:2.21:3.48 respectively for GGBS, Manufacturing Sand (M-sand), and coarse aggregate. Fresh properties and Mechanical properties were examined on all specimens. The findings show an increase in the setting time and flow of concrete and a decrease in density with improved utilization of IBWA. On the other hand, IBWA replacement for GGBS enhanced the mechanical properties. These results revealed that IBWA could be partially replaced as source material for Geopolymer Concrete. This research may contribute to the reduction of dangerous IBWA as a building material.

The Virulence of S. marcescens Strains Isolated From Contaminated Blood Products Is Divergent in the C. elegans Infection Model

Bacterial contamination of platelet concentrates (PCs) can occur during blood donation or PC processing, necessitating routine screening to identify contaminated products in efforts to prevent adverse transfusion reactions in recipient patients. Serratia marcescens is a common bacterial contaminant, and its resilient nature coupled with genetic promiscuity imbue this environmental bacterium with resistance to disinfectants and antibiotics enhancing bacterial virulence. In this study, we aim to understand adaptive survival mechanisms through genetic characterization of two S. marcescens strains, CBS11 and CBS12, isolated from PCs by Canadian Blood Services. Genomic analyses of the two strains indicated that CBS11 has one chromosome and one plasmid (pAM01), whereas CBS12 has no plasmids. Phylogenetic analyses show that CBS11 and CBS12 are non-clonal strains, with CBS11 clustering closely with clinical strain CAV1492 and less so with environmental strain PWN146, and CBS12 clustering with a clinical strain AR_0027. Interestingly, pAM01 was most closely related to PWN146p1, a plasmid found in S. marcescens PWN146 strain associated with pinewood nematode Bursaphelenchus xylophilus. Lastly, the genomic diversity of CBS11 and CBS12 was not reflected in the antibiotic resistance profiles as they were remarkably similar to one another, but was reflected in the virulence phenotypes assessed in the Caenorhabditis elegans nematode infection model, with CBS11 being more virulent then CBS12. Taken together, we suggest that S. marcescens environmental isolates that feature evolutionary diverse genomics are better equipped to adapt and thrive in varied environments, such as that of PCs, and therefore is as much of a concern as multi-drug resistance for human infection potential.

RARE CAUSE OF BACTERAEMIA: MICROBACTERIUM ARBORESCENS.

Microbacterium arborescens, among coryneform bacteria are gram positive rods with orange pigmented colonies. Usually these are environmental contaminant but has shown invasive potential in immunocompromised individuals.A 56 yrs old lady presented with uncontrolled hyperglycaemia and hypertension. M. arborescens was isolated on blood culture. Identication was done based on biochemical characterictics and conrmed by Matrix assisted light desorption ionisation Time of Flight Mass Spectrometry( MALDI TOFF MS). Further amplication and sequencing was done and phylogenetic tree was contructed. Tree clearly shows clinical strain PGI 2 is different from environmental strain

Phage Biocontrol of Pseudomonas aeruginosa in Water

Bacteriophage control of harmful or pathogenic bacteria has aroused growing interest, largely due to the rise of antibiotic resistance. The objective of this study was to test phages as potential agents for the biocontrol of an opportunistic pathogen Pseudomonas aeruginosa in water. Two P. aeruginosa bacteriophages (vB_PaeM_V523 and vB_PaeM_V524) were isolated from wastewater and characterized physically and functionally. Genomic and morphological characterization showed that both were myoviruses within the Pbunavirus genus. Both had a similar latent period (50–55 min) and burst size (124–134 PFU/infected cell), whereas there was variation in the host range. In addition to these environmental phages, a commercial Pseudomonas phage, JG003 (DSM 19870), was also used in the biocontrol experiments. The biocontrol potential of the three phages in water was tested separately and together as a cocktail against two P. aeruginosa strains; PAO1 and the environmental strain 17V1507. With PAO1, all phages initially reduced the numbers of the bacterial host, with phage V523 being the most efficient (>2.4 log10 reduction). For the environmental P. aeruginosa strain (17V1507), only the phage JG003 caused a reduction (1.2 log10) compared to the control. The cocktail of three phages showed a slightly higher decrease in the level of the hosts compared to the use of individual phages. Although no synergistic effect was observed in the host reduction with the use of the phage cocktail, the cocktail-treated hosts did not appear to acquire resistance as rapidly as hosts treated with a single phage. The results of this study provide a significant step in the development of bacteriophage preparations for the control of pathogens and harmful microbes in water environments.

Has Differentiated Instruction Gone ‘Awry’ in Online Teaching and Learning?

Differentiated Instruction (DI) is a classroom strategy that helps teachers to cater their teachings to students with different abilities and learning needs. The issue here is whether DI is still relevant in the online teaching and learning amidst the COVID-19 pandemic. Thus, the aim of this paper is to explore selected ESL teachers’ practices of differentiated instructions in their online classes. It also seeks to examine challenges these teachers withstand while implementing DI in their online classrooms. A qualitative design employing the semi-structured interviews and teachers’ reflection notes are used as data collection instruments. A total of six English language teachers from three selected schools in Malaysia took part in this investigation. Thematic analysis following Braun and Clarke (2006) is applied. The findings revealed that environmental strain, resources constraint and students’ and parents’ attitudes are the main challenges in DI while teaching in an online platform.