Deciphering the Role of a SLOG Superfamily Protein YpsA in Gram-Positive Bacteria

Bacteria adapt to different environments by regulating cell division and several conditions that modulate cell division have been documented. Understanding how bacteria transduce environmental signals to control cell division is critical in understanding the global network of cell division regulation. In this article we describe a role for Bacillus subtilis YpsA, an uncharacterized protein of the SLOG superfamily of nucleotide and ligand-binding proteins, in cell division. We observed that YpsA provides protection against oxidative stress as cells lacking ypsA show increased susceptibility to hydrogen peroxide treatment. We found that the increased expression of ypsA leads to filamentation and disruption of the assembly of FtsZ, the tubulin-like essential protein that marks the sites of cell division in B. subtilis. We also showed that YpsA-mediated filamentation is linked to the growth rate. Using site-directed mutagenesis, we targeted several conserved residues and generated YpsA variants that are no longer able to inhibit cell division. Finally, we show that the role of YpsA is possibly conserved in Firmicutes, as overproduction of YpsA in Staphylococcus aureus also impairs cell division

High fluorescence lymphocyte count in dengue

Background: High fluorescence lymphocyte count (HFLC) is a research parameter indicating the presence of high fluorescence lymphocytes, which represent activated cells (antibody-secreting B- lymphocytes/plasma cells). HFLC in dengue fever is used to estimate the cellular immune response through the presence of blue plasma lymphocytes. Aims: To determine the HFLC in patients with dengue fever using hematology analyser, and to assess the severity of the disease based of the percentage of HFLC. Methods and Material: The present study was conducted in the department of Pathology in a tertiary care hospital. Eighty dengue positive cases and 20 controls were included in the study. HFLC values were obtained from the automated SYSMEX XN 1000 analyser. Statistical analysis of data was done by SPSS23 software. Results: Kruskal Wallis test showed significant difference in platelets between dengue fever, dengue hemorrhagic cases and control groups(p<0.01). Average HFLC% count in dengue fever group is 1.7 and in dengue hemorrhagic fever it is 18.85 and there exist significant difference between them with p<0.01. Conclusions: Increase in HFLC values can be related to the pathogenesis of dengue hemorrhagic fever. The immunological response can be detected by an increase in High Fluorescent Lymphocytes Count (HFLC) which can be observed in the automated Sysmex XN-1000 hematology analyzer. Thus HFLC can be used to assess the severity of the disease, at an early stage