Public Health Research Institute

About: Public Health Research Institute is a based out in . It is known for research contribution in the topics: Population & Randomized controlled trial. The organization has 4889 authors who have published 8149 publications receiving 276945 citations.

Production of an emetic toxin, cereulide, is associated with a specific class of Bacillus cereus

Abstract: The emetic toxin (cereulide) of Bacillus cereus was quantified in several isolates of B. cereus and in various food sources. When the emetic toxin was produced, vomiting-type food poisoning was observed in humans. We also found that the H-1 serovar phenotype was strongly associated with the production of cereulide and that none of the isolates that hydrolyzed starch or expressed diarrheal enterotoxin activity produced cereulide.

Inhibition of cell surface export of group A streptococcal anchorless surface dehydrogenase affects bacterial adherence and antiphagocytic properties.

Abstract: Surface dehydrogenase (SDH) is an anchorless, multifunctional protein displayed on the surfaces of group A Streptococcus (GAS) organisms. SDH is encoded by a single gene, sdh (gap or plr) that is essential for bacterial survival. Hence, the resulting nonfeasibility of creating a knockout mutant is a major limiting factor in studying its role in GAS pathogenesis. An insertion mutagenesis strategy was devised in which a nucleotide sequence encoding a hydrophobic tail of 12 amino acids (337IVLVGLVMLLLS348) was added at the 3′ end of the sdh gene, successfully creating a viable mutant strain (M1-SDHHBtail). In this mutant strain, the SDHHBtail protein was not secreted in the medium but was retained in the cytoplasm and to some extent trapped within the cell wall. Hence, SDHHBtail was not displayed on the GAS surface. The mutant strain, M1-SDHHBtail, grew at the same rate as the wild-type strain. The SDHHBtail protein displayed the same GAPDH activity as the wild-type SDH protein. Although the whole-cell extracts of the wild-type and mutant strains showed similar GAPDH activities, cell wall extracts of the mutant strain showed 5.5-fold less GAPDH activity than the wild-type strain. The mutant strain, M1-SDHHBtail, bound significantly less human plasminogen, adhered poorly to human pharyngeal cells, and lost its innate antiphagocytic activity. These results indicate that the prevention of the cell surface export of SDH affects the virulence properties of GAS. The anchorless SDH protein, thus, is an important virulence factor.

Emergence of Ceftazidime-Avibactam Resistance and Restoration of Carbapenem Susceptibility in Klebsiella pneumoniae Carbapenemase-Producing K pneumoniae: A Case Report and Review of Literature

Abstract: We used meropenem to successfully treat a patient with bacteremia due to ceftazidime-avibactam-resistant, meropenem- susceptible Klebsiella pneumoniae that carried mutant blaKPC-3. Meropenem was bactericidal against ceftazidime-avibactam- resistant K pneumoniae isolates in vitro. Nevertheless, the role of carbapenems in treating such infections remains uncertain, because meropenem resistance is selected readily during passage experiments.