Biology subjects

Bristow, L.

Publications and source records attributed to Bristow, L..

3 recordsLinked to original sources

bioRxiv2021

mRNA-1273 and BNT162b2 mRNA vaccines have reduced neutralizing activity against the SARS-CoV-2 Omicron variant

The BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (Moderna) vaccines generate potent neutralizing antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the global emergence of SARS-CoV-2 variants with mutations in the spike protein, the principal antigenic target of these vaccines, has raised concerns over the neutralizing activity of vaccine-induced antibody responses. The Omicron variant, which emerged in November 2021, consists of over 30 mutations within the spike protein. Here, we used an authentic live virus neutralization assay to examine the neutralizing activity of the SARS-CoV-2 Omicron variant against mRNA vaccine-induced antibody responses. Following the 2nd dose, we observed a 30-fold reduction in neutralizing activity against the omicron variant. Through six months after the 2nd dose, none of the sera from naive vaccinated subjects showed neutralizing activity against the Omicron variant. In contrast, recovered vaccinated individuals showed a 22-fold reduction with more than half of the subjects retaining neutralizing antibody responses. Following a booster shot (3rd dose), we observed a 14-fold reduction in neutralizing activity against the omicron variant and over 90% of boosted subjects showed neutralizing activity against the omicron variant. These findings show that a 3rd dose is required to provide robust neutralizing antibody responses against the Omicron variant.

immunology↗

bioRxiv2021

Rates of primary production in groundwater rival those in oligotrophic marine systems

The terrestrial subsurface contains nearly all of Earths freshwater reserves1 and harbors upwards of 60% of our planets total prokaryotic biomass2,3. While genetic surveys suggest these organisms rely on in situ carbon fixation, rather than the translocation of photosynthetically derived organic carbon4-6, corroborating measurements of carbon fixation in the subsurface are absent. Using a novel ultra-low level 14C-labeling technique, we show that in situ carbon fixation rates in a carbonate aquifer reached 10% of the median rates measured in oligotrophic marine surface waters, and were up to six-fold greater than those observed in lower euphotic zone waters where deep chlorophyll levels peak. Empirical carbon fixation rates were substantiated by both nitrification and anammox rate data. Metagenomic analyses revealed a remarkable abundance of putative chemolithoautotrophic members of an uncharacterized order of Nitrospiria - the first representatives of this class expected to fix carbon via the Wood-Ljungdahl pathway. Based on these fixation rates, we extrapolate global primary production in carbonate groundwaters to be 0.11 Pg of carbon per year.

microbiology↗

bioRxiv2021

Oxygen production by an ammonia-oxidizing archaeon

Ammonia-oxidizing archaea (AOA) are one of the most abundant groups of microbes in the worlds oceans and are key players in the nitrogen cycle. Their energy metabolism, the oxidation of ammonia to nitrite, requires oxygen. Nevertheless, AOA are abundant in environments where oxygen is undetectable. In incubation experiments, where oxygen concentrations were resolved to the nanomolar range, we show that Nitrosopumilus maritimus produces oxygen (O2) and dinitrogen (N2). The pathway is not completely resolved, but it has nitric oxide as a key intermediate. Part of the oxygen produced is directly used for ammonia oxidation, while some accumulates in the surrounding environment. N. maritimus joins a small handful of organisms known to produce oxygen in the dark, and based on this ability, we re-evaluate their role in oxygen-depleted marine environments.

microbiology↗