Herman J. Gonzalez

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Vibrio parahaemolyticus is a marine bacterium that thrives in warm climates. It is a leading cause of gastroenteritis resulting from consumption of contaminated uncooked shellfish. This bacterium harbors two putative type VI secretion systems (T6SS). T6SSs are widespread protein secretion systems found in many Gram-negative bacteria, and are often tightly(More)
The marine bacterium Vibrio parahaemolyticus causes gastroenteritis in humans and encodes the type III effector protein VPA0450, which contributes to host cell death caused by autophagy, cell rounding, and cell lysis. We found that VPA0450 is an inositol polyphosphate 5-phosphatase that hydrolyzed the D5 phosphate from the plasma membrane phospholipid(More)
Metal incorporation and possible cellular compartmentalization of nickel by Staphylococcus aureus was investigated. Cells grown on nutrient agar were removed, washed and exposed to 10, 20, 50 or 100 ppm of nickel in distilled water. The cells were air-dried on Formvar coated grids and then examined in a transmission electron microscope operating in the(More)
The quantitative analysis of laboratory grown organisms (Plectonema boryanum and Staphylococcus aureus) revealed that a typical in vivo polyphosphate body (PPB) contains O (4.3 x 10(-8) microg), C (1.2 x 10(-8) microg), P (6.7 x 10(-9) microg), Mg (1.3 x 10(-9) microg), Ca (6.7 x 10(-10) microg), K (6.7 x 10(-10) microg), Fe (6.0 x 10(-10) microg), S (5.4 x(More)
Three new tetrasaccharide glycosides, differing from one reported previously in the type of short-chain fatty acids ester-linked to the tetrasaccharide core, have been isolated and identified from an oligosaccharide fraction of Ipomea stans. Preliminary screening tests showed that the fraction containing these compounds had pronounced cytotoxicity towards(More)
The effect of five irreversible inhibitors on purified enzyme from Shigella flexneri USCF-129 and also in vitro, was investigated. The I50 was 0.091, 0.30, 0.40 and 0.87 microgram/ml for 6 beta-iodopenicillanic, clavulanic, olivanic and 6 beta-bromopenicillanic acids, respectively, and 255 micrograms/ml for sulbactam. The synergic responses of these(More)
The peptide containing the catalytic serine of beta-lactamase from Shigella flexneri was determined as V-D-E-R-F-P-M-M-S*-T-F-K. It is a local pathogenic strain which produces intestinal problems, especially in children. The highly purified enzyme was prepared by affinity chromatography in phenylboronic acid-agarose gels. The peptide was obtained by tryptic(More)