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The Gonococcal Transcriptome during Infection of the Lower Genital Tract in Women.

McClure R, Nudel K, Massari P, Tjaden B, Su X, Rice PA, Genco CA - PLoS ONE (2015)

Bottom Line: Gonorrhea is a highly prevalent disease resulting in significant morbidity worldwide, with an estimated 106 cases reported annually.A total of 140 genes were increased in expression during natural infection compared to growth in CDM, and 165 genes were decreased in expression.Large differences were found in gene expression profiles under each condition, particularly with genes involved in DNA and RNA processing, iron, transposase, pilin and lipoproteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, United States of America; Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America.

ABSTRACT
Gonorrhea is a highly prevalent disease resulting in significant morbidity worldwide, with an estimated 106 cases reported annually. Neisseria gonorrhoeae, the causative agent of gonorrhea, colonizes and infects the human genital tract and often evades host immune mechanisms until successful antibiotic treatment is used. The alarming increase in antibiotic-resistant strains of N. gonorrhoeae, the often asymptomatic nature of this disease in women and the lack of a vaccine directed at crucial virulence determinants have prompted us to perform transcriptome analysis to understand gonococcal gene expression patterns during natural infection. We sequenced RNA extracted from cervico-vaginal lavage samples collected from women recently exposed to infected male partners and determined the complete N. gonorrhoeae transcriptome during infection of the lower genital tract in women. On average, 3.19% of total RNA isolated from female samples aligned to the N. gonorrhoeae NCCP11945 genome and 1750 gonococcal ORFs (65% of all protein-coding genes) were transcribed. High expression in vivo was observed in genes encoding antimicrobial efflux pumps, iron response, phage production, pilin structure, outer membrane structures and hypothetical proteins. A parallel analysis was performed using the same strains grown in vitro in a chemically defined media (CDM). A total of 140 genes were increased in expression during natural infection compared to growth in CDM, and 165 genes were decreased in expression. Large differences were found in gene expression profiles under each condition, particularly with genes involved in DNA and RNA processing, iron, transposase, pilin and lipoproteins. We specifically interrogated genes encoding DNA binding regulators and iron-scavenging proteins, and identified increased expression of several iron-regulated genes, including tbpAB and fbpAB, during infection in women as compared to growth in vitro, suggesting that during infection of the genital tract in women, the gonococcus is exposed to an iron deplete environment. Collectively, we demonstrate that a large portion of the gonococcal genome is expressed and regulated during mucosal infection including genes involved in regulatory functions and iron scavenging.

No MeSH data available.


Related in: MedlinePlus

Categorization of top 100 expressed N. gonorrhoeae genes during natural mucosal infection in women.The top 100 gonococcal genes expressed in 4 infected subjects were categorized based on gene categories using NCBI information from the NCCP11945 strain. Categories are shown on the y-axis with the ratio of enrichment (percentage of genes of a given functional category in the RNA-seq dataset/percentage of genes of that functional category in the whole gonococcal genome) shown on the x-axis. Ribosomal protein, tRNA, and rRNA genes were removed for clarity.
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pone.0133982.g001: Categorization of top 100 expressed N. gonorrhoeae genes during natural mucosal infection in women.The top 100 gonococcal genes expressed in 4 infected subjects were categorized based on gene categories using NCBI information from the NCCP11945 strain. Categories are shown on the y-axis with the ratio of enrichment (percentage of genes of a given functional category in the RNA-seq dataset/percentage of genes of that functional category in the whole gonococcal genome) shown on the x-axis. Ribosomal protein, tRNA, and rRNA genes were removed for clarity.

Mentions: To gain information on general trends of gonococcal responses to infection in women, we categorized and organized the top 100 gonococcal genes that were most highly expressed when RPKM values from all subjects were averaged together. These genes were categorized based on their gene annotation according to strain NCCP11945, which was chosen because sequences aligned most closely to that strain [22]. To determine the ratio of enrichment, these highly expressed genes were first categorized by function. Then, the percentage of genes in each functional category was compared to the percentage of genes within the same functional category in the whole gonococcal genome. The resulting ratio was defined as the “ratio of enrichment”. The most commonly represented enriched categories that were highly expressed included genes associated with pilin, membrane and stress response as well as traditional housekeeping genes such as those involved in transcription, replication and energy metabolism (Fig 1). Expression of these genes showed variable levels in each of the cervico-vaginal samples, but all were expressed at high levels and, as a whole, reflected the profile of the most highly expressed gonococcal genes during natural infection. As above, several of these genes were also highly expressed in vitro. A specific analysis of genes that showed changes in expression relative to in vitro growth is presented below.


The Gonococcal Transcriptome during Infection of the Lower Genital Tract in Women.

McClure R, Nudel K, Massari P, Tjaden B, Su X, Rice PA, Genco CA - PLoS ONE (2015)

Categorization of top 100 expressed N. gonorrhoeae genes during natural mucosal infection in women.The top 100 gonococcal genes expressed in 4 infected subjects were categorized based on gene categories using NCBI information from the NCCP11945 strain. Categories are shown on the y-axis with the ratio of enrichment (percentage of genes of a given functional category in the RNA-seq dataset/percentage of genes of that functional category in the whole gonococcal genome) shown on the x-axis. Ribosomal protein, tRNA, and rRNA genes were removed for clarity.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526530&req=5

pone.0133982.g001: Categorization of top 100 expressed N. gonorrhoeae genes during natural mucosal infection in women.The top 100 gonococcal genes expressed in 4 infected subjects were categorized based on gene categories using NCBI information from the NCCP11945 strain. Categories are shown on the y-axis with the ratio of enrichment (percentage of genes of a given functional category in the RNA-seq dataset/percentage of genes of that functional category in the whole gonococcal genome) shown on the x-axis. Ribosomal protein, tRNA, and rRNA genes were removed for clarity.
Mentions: To gain information on general trends of gonococcal responses to infection in women, we categorized and organized the top 100 gonococcal genes that were most highly expressed when RPKM values from all subjects were averaged together. These genes were categorized based on their gene annotation according to strain NCCP11945, which was chosen because sequences aligned most closely to that strain [22]. To determine the ratio of enrichment, these highly expressed genes were first categorized by function. Then, the percentage of genes in each functional category was compared to the percentage of genes within the same functional category in the whole gonococcal genome. The resulting ratio was defined as the “ratio of enrichment”. The most commonly represented enriched categories that were highly expressed included genes associated with pilin, membrane and stress response as well as traditional housekeeping genes such as those involved in transcription, replication and energy metabolism (Fig 1). Expression of these genes showed variable levels in each of the cervico-vaginal samples, but all were expressed at high levels and, as a whole, reflected the profile of the most highly expressed gonococcal genes during natural infection. As above, several of these genes were also highly expressed in vitro. A specific analysis of genes that showed changes in expression relative to in vitro growth is presented below.

Bottom Line: Gonorrhea is a highly prevalent disease resulting in significant morbidity worldwide, with an estimated 106 cases reported annually.A total of 140 genes were increased in expression during natural infection compared to growth in CDM, and 165 genes were decreased in expression.Large differences were found in gene expression profiles under each condition, particularly with genes involved in DNA and RNA processing, iron, transposase, pilin and lipoproteins.

View Article: PubMed Central - PubMed

Affiliation: Department of Medicine, Section of Infectious Diseases, Boston University School of Medicine, Boston, MA, United States of America; Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America.

ABSTRACT
Gonorrhea is a highly prevalent disease resulting in significant morbidity worldwide, with an estimated 106 cases reported annually. Neisseria gonorrhoeae, the causative agent of gonorrhea, colonizes and infects the human genital tract and often evades host immune mechanisms until successful antibiotic treatment is used. The alarming increase in antibiotic-resistant strains of N. gonorrhoeae, the often asymptomatic nature of this disease in women and the lack of a vaccine directed at crucial virulence determinants have prompted us to perform transcriptome analysis to understand gonococcal gene expression patterns during natural infection. We sequenced RNA extracted from cervico-vaginal lavage samples collected from women recently exposed to infected male partners and determined the complete N. gonorrhoeae transcriptome during infection of the lower genital tract in women. On average, 3.19% of total RNA isolated from female samples aligned to the N. gonorrhoeae NCCP11945 genome and 1750 gonococcal ORFs (65% of all protein-coding genes) were transcribed. High expression in vivo was observed in genes encoding antimicrobial efflux pumps, iron response, phage production, pilin structure, outer membrane structures and hypothetical proteins. A parallel analysis was performed using the same strains grown in vitro in a chemically defined media (CDM). A total of 140 genes were increased in expression during natural infection compared to growth in CDM, and 165 genes were decreased in expression. Large differences were found in gene expression profiles under each condition, particularly with genes involved in DNA and RNA processing, iron, transposase, pilin and lipoproteins. We specifically interrogated genes encoding DNA binding regulators and iron-scavenging proteins, and identified increased expression of several iron-regulated genes, including tbpAB and fbpAB, during infection in women as compared to growth in vitro, suggesting that during infection of the genital tract in women, the gonococcus is exposed to an iron deplete environment. Collectively, we demonstrate that a large portion of the gonococcal genome is expressed and regulated during mucosal infection including genes involved in regulatory functions and iron scavenging.

No MeSH data available.


Related in: MedlinePlus