EVALUATION OF AQUEOUS AND ETHANOLIC EXTRACTS OF SYZYGIUM CARYOPHYLLATUM FOR ANTIBACTERIAL ACTIVITIES

 Objective: It has been well documented that traditional medicinal plants confer considerable antimicrobial activity against various microorganisms.Methods: The present study was designed to evaluate the antimicrobial properties of aqueous and ethanolic extracts of the leaves of Syzygium caryophyllatum against Staphylococcus aureus, Escherichia coli, Salmonella typhi, Shigella flexneri, and Vibrio cholerae. The aqueous extract was prepared using cold percolation method, and ethanolic extract was prepared in Soxhlet apparatus using ethyl alcohol. Antimicrobial activity is being determined by time-kill assay and minimum inhibitory concentration.Results: From our study, it is found that all tested organisms were sensitive to both aqueous and ethanolic extract of leaves of S. caryophyllatum. The ethanolic extract showed better antibacterial activity against S. aureus and S. typhi when compare to aqueous extract. The phytochemical analysis confirmed the presence of flavonoids, alkaloids, glycosides, steroids, phenols, tannins, and saponins in the ethanolic and aqueous extract of S. caryophyllatum. Conclusion: We hypothesize that these active phytoconstitutents might be responsible for the antimicrobial activity of this plant

Analysis of C-reactive protein level in SARS-CoV-2 patients and its role in predicting the severity of SARS-CoV-2 infection

Introduction: Corona Virus Disease-19 (COVID-19) pandemic is a public health emergency due to the spread of 2019 novel Corona Virus (2019-nCoV), also called as Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2). Analysis of CRP along with various other haematological parameters serves as a predictor of infection and inflammation. Aims and objectives: The aim of the study was to study the CRP level in SARS-CoV-2 patients and its role in predicting the severity of infection. Materials and Methods: As many as 768 patients were included in this study. Serum samples were analysed for CRP levels by Quantitative CRP test, based on the principle of Latex turbidimetry. CRP values equal to or greater than 6mg/L were considered as abnormal. Results: Out of 768 serum samples tested, 337 (43.8%) samples showed abnormal values. Out of which 255 (75.7%) were male patients and 82(24.3%) were female patients. A total of 42.4% patients had increased CRP values that belonged to the age group 41-60 years followed by 29% patients that belonged to the age group of 61-80 years. In the age group of 61-80 years 67/98 (68%) patients deteriorated during hospitalization and required mechanical ventilation and the mortality rate was 88% among patients on mechanical ventilation. Conclusion: Our study suggested that CRP testing may be useful as an earlier indicator for severe illness and those presenting with marked increase of > 45.6 mg/L should be paid more attention. Male preponderance was detected and elderly patients revealed abnormal values of CRP as compared to young and middle-aged patients

Ecology, Virulence and Detection of Pathogenic and Pandemic Vibrio Parahaemolyticus

Vibrio parahaemolyticus is a gram negative, halophilic bacterium that occurs in the coastal and estuarine environments worldwide and is implicated in several cases of seafood-born gastroenteritis around the globe. However, not all strains of V. parahaemolyticus are pathogenic. Clinical isolates of V. parahaemolyticus most often produce either the thermostable direct haemolysin (TDH) or TDH-related haemolysin (TRH) encoded by tdh and trh genes, respectively. A pandemic clone of O3:K6 which was first detected in Kolkata (India), has been responsible for many outbreaks in Asia and the USA. With the emergence of pandemic clone of V. parahaemolyticus, this organism has assumed significance. Although most of the V. parahaemolyticus outbreaks are invariably related to seafood consumption, pathogenic strains are rarely isolated from seafood. Virulent strains producing TDH or TRH and the pandemic clone, which is responsible for most of the outbreaks (that have occurred after 1996) have been rarely isolated from seafood and other environmental samples. This could be due to the occurrence of pathogenic strains in the estuarine environment at a lower level compared to non-pathogenic strains. Another reason can be that the pathogenic stains are more sensitive to dystropic conditions in the aquatic environment and rapidly become non-culturable. Similarity in growth kinetics between virulent and non-virulent strains also made the isolation of virulent strains from the aquatic environment difficult. Several studies were done to determine the factors responsible for an increased virulence and persistance of pandemic clone. However, none of those studies were conclusive. Several researchers have proposed various genetic markers for specific detection of pandemic clone of V. parahaemolyticus. But many of those genetic markers were found to be unreliable. Recently, seven genomic islands (VPaI-1 to VPaI-7) unique to pandemic clone were identified. This Research Topic is dedicated to improve our current understanding of ecology, pathogenesis and detection of pathogenic and pandemic clone of V. parahaemolyticus, and will also strive to identify areas of future development

The cytochrome d oxidase complex regulated by fexA is an Achilles' heel in the in vivo

ABSTRACTVibrio vulnificus is a halophilic estuarine bacterium causing severe opportunistic infections. To successfully establish an infection, V. vulnificus must adapt to redox fluctuations in vivo. In the present study, we show that deletion of V. vulnificus fexA gene caused hypersensitivity to acid and reactive oxygen species. The ΔfexA mutant exhibited severe in vivo survival defects. For deeper understanding the role of fexA gene on the successful V. vulnificus infection, we analyzed differentially expressed genes in ΔfexA mutant in comparison with wild type under aerobic, anaerobic or in vivo culture conditions by genome-scale DNA microarray analyses. Twenty-two genes were downregulated in the ΔfexA mutant under all three culture conditions. Among them, cydAB appeared to dominantly contribute to the defective phenotypes of the ΔfexA mutant. The fexA deletion induced compensatory point mutations in the cydAB promoter region over subcultures, suggesting essentiality. Those point mutations (PcydSMs) restored bacterial growth, motility, cytotoxicity ATP production and mouse lethality in the ΔfexA mutant. These results indicate that the cydAB operon, being regulated by FexA, plays a crucial role in V. vulnificus survival under redox-fluctuating in vivo conditions. The FexA-CydAB axis should serve an Achilles heel in the development of therapeutic regimens against V. vulnificus infection

Association between phytoplankton and Vibrio spp. along the southwest coast of India : a mesocosm experiment

We report the results from a mesocosm study investigating the interrelationship between microalgae and vibrios. The mesocosms were inoculated with plankton, plankton + sediment, or sediment. We followed the diatom bloom and increases in the abundance of Vibrio spp. and V parahaemolyticus in conjunction with several environmental variables in all mesocosms and at a reference site. The dominating diatom genera were also identified. Temperature, salinity, and pH were nearly invariant in the mesocosms and did not contribute to the results. The principal environmental variables that correlated to vibrio abundance were total bacterial plate counts, phosphorus and ammonia (positive relationship), and oxygen and silica (negative). Nitrate, total bacterial counts and chlorophyll a (chl a) did not correlate with vibrio growth. The highest diatom abundances were followed by increases in vibrios in all mesocosms. This was also observed in field sampling. Together, these results suggest that diatom blooms could support Vibrio spp. growth. V parahaemolyticus was initially favoured by sediment. The contribution of V parahaemolyticus to the total bacterial population was low, on average 0.5 %, but constituted a rather high proportion of the vibrio population in the mesocosm systems, i.e. on average 18 %. Some of the identified diatom genera, e.g. Chaetoceros and Skeletonema, were negatively correlated to vibrios, while Coscinodiscus was positively correlated. The results indicate that phytoplankton blooms, when recorded as high levels of chl a, should be used with caution as predictors for future vibrio epidemics, since the origin of the chl a might have a significant effect on vibrio abundance