Project description:Neisseria gonorrhoeae is the causative agent of gonorrhea, a leading sexually transmitted disease with severe complications on reproductive health. The U.S. Centers for Disease Control and Prevention has categorized the public health threat induced by N. gonorrhoeae as “urgent”, due to the ease of transmission and the fast emergence of multi-drug resistant strains. The need for development of vaccines and understanding the underlying factors leading to antibiotic resistance is of utmost importance. The proteomic profiles of the 14 WHO N. gonorrhoeae reference strains have been compared to the WHO F reference strain using a mass spectrometry with tandem mass tags (TMT) labeling to analyze the cell envelope and the cytoplasmic fractions extracted from each strain. Identifying novel vaccine candidates and proteomic signatures for antimicrobial resistance will further our understanding of N. gonorrhoeae proteotypes, in relationship to their respective genotypes and phenotypes, and provide deep insights that will impact the development of preventive and therapeutic tools to combat gonorrhea.
Project description:Microarray comparative genome hybridization (mCGH) data was collected from one Neisseria cinerea, two Neisseria lactamica, two Neisseria gonorrhoeae, and 48 Neisseria meningitidis isolates. For N. meningitidis, these isolates are from diverse clonal complexes, invasive and carriage strains, and all major serogroups. The microarray platform represented N. meningitidis strains MC58, Z2491, and FAM18 and N. gonorrhoeae FA1090.
Project description:Comparison of transcriptional profiling between the 3 Neisseria meningitidis strains [serogroup A (Z2491), Serogroup B (MC58), and Serogroup C (FAM18)] and the 2 Neisseria gonorrhoeae strain (FA1090 and MS11).
Project description:Regulation of gene expression by small non-coding RNAs (sRNAs) plays a critical role in bacterial response to physiological stresses. NrrF, a trans-acting sRNA in Neisseria meningitidis and Neisseria gonorrhoeae, has been shown in the meningococcus to indirectly control, in response to iron (Fe) availability, the transcription of genes encoding subunits of succinate dehydrogenase, a Fe-requiring enzyme. Given that in other organisms sRNAs target multiple mRNAs to control gene expression, we used a global approach to examine the role of NrrF in controlling gonococcal transcription. Three strains, including N. gonorrhoeae FA1090, an nrrF deletion mutant and a complemented derivative were examined using a custom CombiMatrix microarray to assess the role of this sRNA in controlling gene expression in response to Fe availability. In the absence of NrrF, mRNA half-lives increased for 12 genes in Fe-depleted growth conditions, compared to FA1090. Biological functions for the 12 genes controlled by NrrF included energy metabolism, oxidative stress, antibiotic resistance, amino acid synthesis and a regulatory protein whose functions are not fully understood, in addition to hypothetical proteins.
Project description:In this study wild-type, fur mutant, and complemented fur mutant strains of the human pathogen Neisseria gonorrhoeae F62 were grown under high (100 uM iron) or low (100 uM desferal) iron conditions to identify genes whose expression was regulated by iron and/or Fur
Project description:The overall goals and objectives of this study are to investigate the transcriptomics of Neisseria gonorrhoeae using RNA-seq. This work will look at gene expression, start points of transcription, transcriptional termination, and differences between these in different conditions and between strains and growing cultures over time.
Project description:Synonymous mutations do not change the sequence of the polypeptide but they may still influence fitness. We investigated in Salmonella enterica how four synonymous mutations in the rpsT gene (encoding ribosomal protein S20) reduce fitness (i.e. growth rate) and the mechanisms by which this cost can be genetically compensated. The reduced growth rates of the synonymous mutants were correlated with reduced levels of the rpsT transcript and S20 protein. In an adaptive evolution experiment these fitness impairments could be compensated by mutations that either caused up-regulation of S20 through increased gene dosage (due to duplications), increased transcription of the rpsT gene (due to an rpoD mutation or mutations in rpsT), or increased translation from the rpsT transcript (due to rpsT mutations). We suggest that the reduced levels of S20 in the synonymous mutants result in production of a defective subpopulation of 30S subunits lacking S20 that reduce protein synthesis and bacterial growth and that the compensatory mutations restore S20 levels and the number of functional ribosomes. Our results demonstrate how specific synonymous mutations can cause substantial fitness reductions and that many different types intra- and extragenic compensatory mutations can efficiently restore fitness. Furthermore, our study highlights that also synonymous sites can be under strong selection, which may have implications for the use of dN/dS ratios as signature for selection.
Project description:Regulation of gene expression by small non-coding RNAs (sRNAs) plays a critical role in bacterial response to physiological stresses. NrrF, a trans-acting sRNA in Neisseria meningitidis and Neisseria gonorrhoeae, has been shown in the meningococcus to indirectly control, in response to iron (Fe) availability, the transcription of genes encoding subunits of succinate dehydrogenase, a Fe-requiring enzyme. Given that in other organisms sRNAs target multiple mRNAs to control gene expression, we used a global approach to examine the role of NrrF in controlling gonococcal transcription. Three strains, including N. gonorrhoeae FA1090, an nrrF deletion mutant and a complemented derivative were examined using a custom CombiMatrix microarray to assess the role of this sRNA in controlling gene expression in response to Fe availability. In the absence of NrrF, mRNA half-lives increased for 12 genes in Fe-depleted growth conditions, compared to FA1090. Biological functions for the 12 genes controlled by NrrF included energy metabolism, oxidative stress, antibiotic resistance, amino acid synthesis and a regulatory protein whose functions are not fully understood, in addition to hypothetical proteins. 18 samples. Three separate biological replicates for both growth conditions (Fe deplete and Fe replete) were done for all each isolate (6 samples per isolate); FA1090 wild type strain; NrrF_mutant strain LJ001; NrrF_complemented strain LJ002