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Saloma, C. P.

Publications and source records attributed to Saloma, C. P..

2 recordsLinked to original sources

Structural Analysis of Spike Protein Mutations in an Emergent SARS-CoV-2 Variant from the Philippines

A SARS-CoV-2 lineage designated as P.3 with multiple signature mutations in the Spike protein region was recently reported with cases from the Central Visayas Region of the Philippines. Whole genome sequencing revealed that the 33 samples under this lineage all contain the E484K, N501Y, and P681H Spike mutations previously found in variants of concern (VOC) such as the B.1.351, the P.1 and B.1.1.7 variants first reported in South Africa, Brazil, and the United Kingdom, respectively. The possible implications of the mutations found in the Spike protein of P.3 were analyzed for their potential effects on structure, stability, and molecular surface character. The analysis suggests that these mutations could significantly impact the possible interactions of the Spike protein with the ACE2 receptor and neutralizing antibodies, and warrants further clinical investigation. Some of the mutations affecting the N and C terminal domains may have effects on Spike monomer and trimer stability. This report provides insights on relevant targets for the design of future diagnostics, therapeutics and vaccines against the evolving SARS-CoV-2 variants in the Philippines.

biophysics

Identification of a chromosomally-encoded sucrose operon-like gene cluster in Vibrio parahaemolyticus strain PH05 isolated from Negros Island, Philippines

The ability of bacteria to metabolize a wide variety of carbon sources has been known to aid in their ability for efficient colonization. Vibrio parahaemolyticus, a known aquatic pathogen has been reported to have the ability to metabolize a number of carbohydrates including D-glucose, D-galactose, L-arabinose, D-mannose, and D-ribose to name a few. Classical isolation of V. parahaemolyticus from other members of the family Vibrionaceae relies on its carbon utilization pattern. Conventionally, V. parahaemolyticus lacks the ability to utilize sucrose and this has been the basis for its isolation using the Thiosulfate-citrate-bile salts-sucrose (TCBS) agar. Reports of V. parahaemolyticus having the ability to utilize sucrose have been presented yet there is paucity of information and detailed study on this phenotype. In this study, we report the V. parahaemolyticus strain PH05 that has the ability to metabolize sucrose. Phenotypic and genotypic characterization of this V. parahaemolyticus strain isolated from Negros Island, Philippines, revealed that V. parahaemolyticus strain PH05 is atypical appearing yellow on TCBS agar plates. It is capable of utilizing sucrose, unlike the majority of V. parahaemolyticus isolates. Genome analyses of this strain revealed the presence of a chromosomally encoded sucrose operon-like gene cluster encoded in chromosome 2 with the following sucrose-utilization associated genes: scrY, ccpA, treP, scrK, and scrB genes coding for sucrose porin, catabolite control protein A, PTS System sucrose-specific EIIBC component, fructokinase, and sucrose-6-phosphate hydrolase. The mode of transmission of these genes to V. parahaemolyticus strain PH05 is still unknown. However, the presence of insertion sequences (IS) and phage elements in the same chromosome suggests horizontal gene transfer events. Taken together, our results point to the possibility that acquired sucrose utilization genes may contribute to the fitness of V. parahaemolyticus strain PH05 in the environment.

microbiology