Sub-Lethal levels of Gentamicin impacts gonococcal gene expression
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ABSTRACT:
ORGANISM(S): Neisseria gonorrhoeae
PROVIDER: GSE291660 | GEO | 2025/05/22
REPOSITORIES: GEO
Similar Datasets
Project description:Sub-Lethal levels of Gentamicin impacts gonococcal gene expression
| PRJNA1234610 | ENA
Project description:Gentamicin resistance in Neisseria gonorrhoeae
| PRJEB56638 | ENA
Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates. two strains, two growth phases, three replicates each.
2012-04-03 | E-GEOD-32717 | biostudies-arrayexpress
Project description:Previous studies have shown that the MpeR transcriptional regulator produced by Neisseria gonorrhoeae represses expression of mtrF, which encodes a putative inner membrane protein that works with the MtrC-MtrD-MtrE efflux pump to allow gonococci to resist high levels of multiple hydrophobic antimicrobials. Regulation of mpeR has been reported to occur by an iron-dependent mechanism involving Fur (Ferric uptake regulator). Collectively, these observations suggest the presence of an interconnected regulatory system in gonococci that modulates expression of drug efflux pump protein-encoding genes in an iron-responsive manner. Herein, we describe this connection and report that levels of gonococcal resistance to a substrate of the mtrCDE-encoded efflux pump can be modulated by MpeR and the availability of free iron. Using microarray analysis, we found that the mtrR gene, which encodes the direct transcriptional repressor (MtrR) of mtrCDE, is an MpeR-repressed determinant in the late-logarithmic phase of growth when free iron levels would be reduced due to bacterial consumption. MpeR-mediated repression of mtrR appeared to be direct, as judged by DNA-binding analyses, and was enhanced by conditions of iron-limitation, which resulted in increased expression of the mtrCDE efflux pump operon. Taken together, our results indicate that both genetic and physiologic parameters can influence expression of the mtr efflux system and that these can modulate levels of gonococcal susceptibility to efflux pump substrates.
2012-04-04 | GSE32717 | GEO
Project description:Maintenance of an anaerobic respiratory system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobic and anaerobically grown cells. We found that the anaerobic stimulon in gonococci was large, and that 198 chromosomal genes were found to be differentially expressed. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Secondary analysis of genes found to be differentially expressed by RNA-seq using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. Several novel factors were identified to be anaerobically regulated, as well as a large number of hypothetical proteins were induced. Two biological replicates of cells grown aerobically or anaerobically with nitrite were analyzed, for a total of four samples subject to SOLiD RNA sequencing.
2011-01-26 | E-GEOD-26444 | biostudies-arrayexpress
Project description:The emergence of fully antimicrobial resistant Neisseria gonorrhoeae has led global public health agencies to identify a critical need for next generation anti-gonococcal pharmaceuticals. The development and success of these compounds will rely upon valid pre-clinical models of gonorrhoeae infection. We recently developed and reported the first model of upper genital tract gonococcal infection. During initial characterization, we observed significant reproductive cycle-based variation in infection outcome. When uterine infection occurred in the diestrus phase, there was significantly greater pathology than during estrus phase. The aim of this study was to evaluate transcriptional profiles of infected uterine tissue from mice in either estrus or diestrus phase in order to elucidate possible mechanisms for these differences. Genes and biological pathways with phase-independent induction during infection showed a chemokine dominant cytokine response to Neisseria gonorrhoeae. Despite general induction being phase-independent, this common anti-gonococcal response demonstrated greater induction during diestrus phase infection. Greater activity of granulocyte adhesion and diapedesis regulators during diestrus infection, particularly in chemokines and diapedesis regulators, was also shown. In addition to a greater induction of the common anti-gonococcal response, Gene Set Enrichment Analysis (GSEA) identified a diestrus-specific induction of type-1 interferon signaling pathways. This transcriptional analysis of murine uterine gonococcal infection during distinct points in the natural reproductive cycle provided evidence for a common anti-gonococcal response characterized by significant induction of granulocyte chemokine expression and high proinflammatory mediators. The basic biology of this host response to N. gonorrhoeae in estrus and diestrus is similar at the pathway level, but varies drastically in magnitude. Overlaying this, we observed type-1 interferon induction specifically in diestrus infection where greater pathology is observed. This supports recent work suggesting this pathway has a significant, possibly host-detrimental, function in gonococcal infection. Together these findings lay the groundwork for further examination of the role of interferons in gonococcal infection. Additionally, this work enables the implementation of the diestrus uterine infection model using the newly characterized host response as a marker of pathology and its prevention as a correlate of candidate vaccine efficacy and ability to protect against the devastating consequences of N. gonorrhoeae-associated sequelae. Murine microarrays were used to examine transcriptional differences underlying significantly different phenotypes associated with uterine N. gonorrhoeae infection in the estrus versus diestrus phases of the natural reproductive cycle.
2018-08-27 | GSE113962 | GEO
Project description:Gentamicin is a highly efficacious antibiotic against gram-negative bacteria. However, its usefulness in treating infection is compromised by its poorly understood renal toxicity. This toxic effect is seen in a variety of organisms. While the yeast Saccharomyces cerevisiae is relatively insensitive to gentamicin, mutations in any one of 20 or so genes causes a dramatic increase in sensitivity. Many of these genes encode proteins important for translation termination or specific protein trafficking complexes. Here, we demonstrate by microarray analysis that gentamicin treatment leads to dramatic decreases in genes under the control of the MADS box protein Mcm1, including genes encoding products involved in mating, nitrogen utilization, and ribosome biogenesis. Furthermore, microarray analysis also demonstrates an increase in a Rlm1-dependent set of genes involved in maintaining the structure of the cell wall that are also induced by the antifungal agents caspofungin and calcofluor white. Subsequent inspection of the physical and genetic interactions of the remaining gentamicin sensitive mutants revealed a network centered around chitin synthase and the Arf Pathway. Furthermore, conditional arf1 mutants are hypersensitive to gentamicin even under permissive conditions. These results suggest that gentamicin may act as a cell wall stress, possibly by disrupting Arf-dependent trafficking of proteins involved in forming the cell wall. Keywords: disease state analysis, comparative genomic analysis +/- gentamicin treatment
2007-10-14 | GSE7188 | GEO
Project description:Maintenance of an anaerobic respiratory system in the obligate human pathogen, Neisseria gonorrhoeae, suggests that an anaerobic lifestyle may be important during the course of infection. However, at this point there have been no studies analyzing the complete gonococcal transcriptome response to anaerobiosis. Here we performed deep sequencing to compare the gonococcal transcriptomes of aerobic and anaerobically grown cells. We found that the anaerobic stimulon in gonococci was large, and that 198 chromosomal genes were found to be differentially expressed. We also observed a large induction of genes encoded within the cryptic plasmid, pJD1. Secondary analysis of genes found to be differentially expressed by RNA-seq using translational-lacZ fusions or RT-PCR demonstrated the RNA-seq results to be very reproducible. Surprisingly, many genes of prophage origin were induced anaerobically, as well as several transcriptional regulators previously unknown to be involved in anaerobic growth. We also confirmed expression and regulation of a small RNA, likely a functional equivalent of fnrS in the Enterobacteriaceae family. Several novel factors were identified to be anaerobically regulated, as well as a large number of hypothetical proteins were induced.
2011-01-26 | GSE26444 | GEO
Project description:In chick basilar papilla, hair cells can be regenerated after gentamicin treatment. To identify genes and pathways involved in this process, we performed microarray analysis on the basilar papilla 0, 48 and 72 hours after gentamicin.
2016-12-01 | GSE79963 | GEO
Project description:Bacterial type 4 pili (T4P) are extracellular polymers that serve both as adhesins and molecular motors. Functionally, they are involved in adhesion, colony formation, twitching motility, and horizontal gene transfer. T4P of the human pathogen Neisseria gonorrhoeae have been shown to enhance survivability under treatment with antibiotics or hydrogen peroxide. However, little is known about the effect of external stresses on T4P production and motor properties. Here, we address this question by directly visualizing gonococcal T4P dynamics. We show that in the absence of stress gonococci produce T4P at a remarkably high rate of ~ 200 T4P min-1. T4P retraction succeeds elongation without detectable time delay. Treatment with azithromycin or ceftriaxone reduces the T4P production rate. RNA sequencing results suggest that reduced piliation is caused by combined downregulation of the complexes required for T4P extrusion from the cell envelope and cellular energy depletion. Various other stresses including inhibitors of cell wall synthesis and DNA replication, as well as hydrogen peroxide and lactic acid, inhibit T4P production. Moreover, hydrogen peroxide and acidic pH strongly affect pilus length and motor function. In summary, we show that gonococcal T4P are highly dynamic and diverse external stresses reduce piliation despite the protective effect of T4P against some of these stresses.
2022-02-02 | GSE195465 | GEO