Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
Ann Emerg Med ; 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38795079

RESUMO

STUDY OBJECTIVE: Boarding admitted patients in emergency departments (EDs) is a national crisis that is worsening despite potential financial disadvantages. The objective of this study was to assess costs associated with boarding. METHODS: We conducted a prospective, observational investigation of patients admitted through an ED for management of acute stroke at a large, urban, academic, comprehensive stroke center hospital. We employed time-driven activity-based costing methodology to estimate cost for patient care activities during admission and aggregated results to estimate the total cost of boarding versus inpatient care. Primary outcomes were total daily costs per patient for medical-surgical (med/surg) boarding, med/surg inpatient care, ICU boarding, and ICU inpatient care. RESULTS: The total daily cost per patient with acute stroke was US$1856, for med/surg boarding versus US$993 for med/surg inpatient care and US$2267, for ICU boarding versus US$2165, for ICU inpatient care. These differences were even greater when accounting for costs associated with traveler nurses. ED nurses spent 293 min/d (mean) caring for each med/surg boarder; inpatient nurses spent 313 min/d for each med/surg inpatient. ED nurses spent 419 min/d caring for each ICU boarder; inpatient nurses spent 787 min/d for each ICU inpatient. Neurology attendings and residents spent 25 and 52 min/d caring for each med/surg boarder versus 62 minutes and 90 minutes for each med/surg inpatient, respectively. CONCLUSION: Using advanced cost-accounting methods, our investigation provides novel evidence that boarding of admitted patients is financially costly, adding greater urgency for elimination of this practice.

2.
Infect Immun ; 91(5): e0007923, 2023 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-37092998

RESUMO

Neisseria meningitidis historically has been an infrequent and sporadic cause of urethritis and other urogenital infections. However, a nonencapsulated meningococcal clade belonging to the hyperinvasive clonal complex 11.2 lineage has recently emerged and caused clusters of urethritis cases in the United States and other countries. One of the genetic signatures of the emerging N. meningitidis urethritis clade (NmUC) is a chromosomal gene conversion event resulting in the acquisition of the Neisseria gonorrhoeae denitrification apparatus-the N. gonorrhoeae alleles encoding the nitrite reductase AniA, the nitric oxide (NO) reductase NorB, and the intergenic promoter region. The biological importance of the N. gonorrhoeae AniA-NorB for adaptation of the NmUC to a new environmental niche is investigated herein. We found that oxygen consumption, nitrite utilization, and NO production were significantly altered by the conversion event, resulting in different denitrifying aerobic and microaerobic growth of the clade. Further, transcription of aniA and norB in NmUC isolates differed from canonical N. meningitidis, and important polymorphisms within the intergenic region, which influenced aniA promoter activity of the NmUC, were identified. The contributions of three known meningococcal regulators (NsrR, FNR, and NarQP) in controlling the denitrification pathway and endogenous NO metabolism were distinct. Overall, transcription of aniA was dampened relative to canonical N. meningitidis, and this correlated with the lower NO accumulation in the clade. Denitrification and microaerobic respiration were bolstered, and protection against host-derived NO was likely enhanced. The acquisition of the N. gonorrhoeae denitrification pathway by the NmUC supports the clade's adaptation and survival in a microaerobic urogenital environment.


Assuntos
Gonorreia , Neisseria meningitidis , Uretrite , Estados Unidos , Humanos , Neisseria meningitidis/genética , Neisseria meningitidis/metabolismo , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/metabolismo , Óxido Nítrico/metabolismo , Respiração
3.
Antimicrob Agents Chemother ; 67(1): e0096822, 2023 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-36602335

RESUMO

Neisseria gonorrhoeae has developed resistance to all previous antibiotics used for treatment. This highlights a crucial need for novel antimicrobials to treat gonococcal infections. We previously showed that carbamazepine (Cz), one of the most commonly prescribed antiepileptic drugs, can block the interaction between gonococcal pili and the I-domain region of human complement receptor 3 (CR3)-an interaction that is vital for infection of the female cervix. We also show that Cz can completely clear an established N. gonorrhoeae infection of primary human cervical cells. In this study, we quantified Cz in serum, saliva, and vaginal fluid collected from 16 women who were, or were not, regularly taking Cz. We detected Cz in lower reproductive tract mucosal secretions in the test group (women taking Cz) at potentially therapeutic levels using a competitive ELISA. Furthermore, we found that Cz concentrations present in vaginal fluid from women taking this drug were sufficient to result in a greater than 99% reduction (within 24 h) in the number of viable gonococci recovered from ex vivo, human, primary cervical cell infections. These data provide strong support for the further development of Cz as a novel, host-targeted therapy to treat gonococcal cervicitis.


Assuntos
Epilepsia , Gonorreia , Humanos , Feminino , Reposicionamento de Medicamentos , Gonorreia/tratamento farmacológico , Neisseria gonorrhoeae , Carbamazepina/uso terapêutico , Carbamazepina/farmacologia
4.
Antimicrob Agents Chemother ; 66(9): e0231821, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-35980187

RESUMO

Multidrug-resistant (MDR) N. gonorrhoeae is a current public health threat. New therapies are urgently needed. PBT2 is an ionophore that disrupts metal homeostasis. PBT2 administered with zinc is shown to reverse resistance to antibiotics in several bacterial pathogens. Here we show that both N. meningitidis and MDR N. gonorrhoeae are sensitive to killing by PBT2 alone. PBT2 is, thus, a candidate therapeutic for MDR N. gonorrhoeae infections.


Assuntos
Gonorreia , Neisseria meningitidis , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Humanos , Ionóforos/farmacologia , Ionóforos/uso terapêutico , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , Zinco
5.
J Antimicrob Chemother ; 76(11): 2850-2853, 2021 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-34450628

RESUMO

BACKGROUND: Neisseria gonorrhoeae is a Gram-negative bacterial pathogen that causes gonorrhoea. No vaccine is available to prevent gonorrhoea and the emergence of MDR N. gonorrhoeae strains represents an immediate public health threat. OBJECTIVES: To evaluate whether PBT2/zinc may sensitize MDR N. gonorrhoeae to natural cationic antimicrobial peptides. METHODS: MDR strains that contain differing resistance mechanisms against numerous antibiotics were tested in MIC assays. MIC assays were performed using the broth microdilution method according to CLSI guidelines in a microtitre plate. Serially diluted LL-37 or PG-1 was tested in combination with a sub-inhibitory concentration of PBT2/zinc. Serially diluted tetracycline was also tested with sub-inhibitory concentrations of PBT2/zinc and LL-37. SWATH-MS proteomic analysis of N. gonorrhoeae treated with PBT2/zinc, LL-37 and/or tetracycline was performed to determine the mechanism(s) of N. gonorrhoeae susceptibility to antibiotics and peptides. RESULTS: Sub-inhibitory concentrations of LL-37 and PBT2/zinc synergized to render strain WHO-Z susceptible to tetracycline, whereas the killing effect of PG-1 and PBT2/zinc was additive. SWATH-MS proteomic analysis suggested that PBT2/zinc most likely leads to a loss of membrane integrity and increased protein misfolding and, in turn, results in bacterial death. CONCLUSIONS: Here we show that PBT2, a candidate Alzheimer's and Huntington's disease drug, can be repurposed to render MDR N. gonorrhoeae more susceptible to the endogenous antimicrobial peptides LL-37 and PG-1. In the presence of LL-37, PBT2/zinc can synergize with tetracycline to restore tetracycline susceptibility to gonococci resistant to this antibiotic.


Assuntos
Doença de Alzheimer , Gonorreia , Doença de Huntington , Preparações Farmacêuticas , Doença de Alzheimer/tratamento farmacológico , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos , Gonorreia/tratamento farmacológico , Humanos , Doença de Huntington/tratamento farmacológico , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , Proteômica
6.
J Infect Dis ; 221(3): 449-453, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31541571

RESUMO

L-lactate is an abundant metabolite in a number of niches in host organisms and represents an important carbon source for bacterial pathogens such as Neisseria gonorrhoeae. In this study, we describe an alternative, iron-sulfur cluster-containing L-lactate dehydrogenase (LutACB), that is distinct from the flavoprotein L-lactate dehydrogenase (LldD). Expression of lutACB was found to be positively regulated by iron, whereas lldD was more highly expressed under conditions of iron-limitation. The functional role of LutACB and LldD was reflected in in vitro studies of growth and in the survival of N gonorrhoeae in primary cervical epithelial cells.


Assuntos
Proteínas de Bactérias/metabolismo , Colo do Útero/citologia , Células Epiteliais/microbiologia , Gonorreia/metabolismo , L-Lactato Desidrogenase/metabolismo , Viabilidade Microbiana/genética , Neisseria gonorrhoeae/enzimologia , Proteínas de Bactérias/genética , Feminino , Deleção de Genes , Regulação Bacteriana da Expressão Gênica , Gonorreia/microbiologia , Humanos , Ferro/metabolismo , L-Lactato Desidrogenase/genética , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/crescimento & desenvolvimento , RNA Viral/genética
7.
Curr Opin Infect Dis ; 31(3): 246-250, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29601324

RESUMO

PURPOSE OF REVIEW: Neisseria gonorrhoeae is one of the most common causes of sexually transmitted infections, with an estimated more than 100 million cases of gonorrhea each year worldwide. N. gonorrhoeae has gained recent increasing attention because of the alarming rise in incidence and the widespread emergence of multidrug-resistant gonococcal strains. Vaccine development is one area of renewed interest. Herein, we review the recent advances in this area. RECENT FINDINGS: Vaccine development for N. gonorrhoeae has been problematic, but recent progress in the field has provided new hope that a gonococcal vaccine may be feasible. Several new vaccine antigens have been characterized in various models of infection. Furthermore, the first potential vaccine-induced protection against gonorrhea in humans has been reported, with decreased rates of gonorrhea described among individuals vaccinated with the Neisseria meningitidis serogroup B vaccine, MeNZB. SUMMARY: As antibiotic resistance continues to increase, vaccine development for N. gonorrhoeae becomes more urgent. The MeNZB vaccine is shown to have efficacy, albeit relatively low, against N. gonorrhoeae. This finding has the potential to reinvigorate research in the field of gonococcal vaccine development and will guide future studies of the antigens and mechanism(s) required for protection against gonococcal infection.


Assuntos
Vacinas Bacterianas/imunologia , Transmissão de Doença Infecciosa/prevenção & controle , Descoberta de Drogas/tendências , Gonorreia/prevenção & controle , Vacinas Meningocócicas/imunologia , Neisseria gonorrhoeae/imunologia , Vacinas Bacterianas/isolamento & purificação , Humanos , Vacinas Meningocócicas/administração & dosagem
8.
Crit Rev Microbiol ; 42(6): 928-41, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26805040

RESUMO

Gonorrhea is a major, global public health problem for which there is no vaccine. The continuing emergence of antibiotic-resistant strains raises concerns that untreatable Neisseria gonorrhoeae may become widespread in the near future. Consequently, there is an urgent need for increased efforts towards the development of new anti-gonococcal therapeutics and vaccines, as well as suitable models for potential pre-clinical vaccine trials. Several current issues regarding gonorrhea are discussed herein, including the global burden of disease, the emergence of antibiotic-resistance, the status of vaccine development and, in particular, a focus on the model systems available to evaluate drug and vaccine candidates. Finally, alternative approaches to evaluate vaccine candidates are presented. Such approaches may provide valuable insights into the protective mechanisms, and correlates of protection, required to prevent gonococcal transmission, local infection and disease sequelae.


Assuntos
Vacinas Bacterianas/imunologia , Gonorreia/imunologia , Gonorreia/prevenção & controle , Neisseria gonorrhoeae/imunologia , Animais , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Gonorreia/microbiologia , Humanos , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/patogenicidade , Virulência
9.
PLoS Pathog ; 9(5): e1003377, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23696740

RESUMO

Pili of pathogenic Neisseria are major virulence factors associated with adhesion, twitching motility, auto-aggregation, and DNA transformation. Pili of N. meningitidis are subject to several different post-translational modifications. Among these pilin modifications, the presence of phosphorylcholine (ChoP) and a glycan on the pilin protein are phase-variable (subject to high frequency, reversible on/off switching of expression). In this study we report the location of two ChoP modifications on the C-terminus of N. meningitidis pilin. We show that the surface accessibility of ChoP on pili is affected by phase variable changes to the structure of the pilin-linked glycan. We identify for the first time that the platelet activating factor receptor (PAFr) is a key, early event receptor for meningococcal adherence to human bronchial epithelial cells and tissue, and that synergy between the pilin-linked glycan and ChoP post-translational modifications is required for pili to optimally engage PAFr to mediate adherence to human airway cells.


Assuntos
Aderência Bacteriana , Membrana Celular/metabolismo , Células Epiteliais/metabolismo , Proteínas de Fímbrias/metabolismo , Fímbrias Bacterianas/metabolismo , Neisseria meningitidis/metabolismo , Processamento de Proteína Pós-Traducional , Mucosa Respiratória/metabolismo , Linhagem da Célula , Membrana Celular/microbiologia , Células Epiteliais/microbiologia , Proteínas de Fímbrias/genética , Fímbrias Bacterianas/genética , Humanos , Neisseria meningitidis/genética , Neisseria meningitidis/patogenicidade , Fosforilcolina/metabolismo , Mucosa Respiratória/microbiologia
10.
J Infect Dis ; 210(8): 1311-8, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24737798

RESUMO

Lactate is an abundant metabolite, produced by host tissues and commensal organisms, and it represents an important potential carbon source for bacterial pathogens. In the case of Neisseria spp., the importance of the lactate permease in colonization of the host has been demonstrated, but there have been few studies of lactate metabolism in pathogenic Neisseria in the postgenomic era. We describe herein the characterization of genome-annotated, respiratory, and substrate-level lactate dehydrogenases (LDHs) from the obligate human pathogen Neisseria gonorrhoeae. Biochemical assays using N. gonorrhoeae 1291 wild type and isogenic mutant strains showed that cytoplasmic LdhA (NAD(+)-dependent D-lactate dehydrogenase) and the membrane-bound respiratory enzymes, LdhD (D-lactate dehydrogenase) and LldD (L-lactate dehydrogenase) are correctly annotated. Mutants lacking LdhA and LdhD showed greatly reduced survival in neutrophils compared with wild type cells, highlighting the importance of D-lactate metabolism in gonococcal survival. Furthermore, an assay of host colonization using the well-established human primary cervical epithelial cell model revealed that the two respiratory enzymes make a significant contribution to colonization of and survival within the microaerobic environment of the host. Taken together, these data suggest that host-derived lactate is critical for the growth and survival of N. gonorrhoeae in human cells.


Assuntos
Colo do Útero/citologia , Células Epiteliais/microbiologia , Lactato Desidrogenases/metabolismo , Neisseria gonorrhoeae/enzimologia , Neutrófilos/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , Feminino , Regulação Bacteriana da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Humanos , Lactato Desidrogenases/genética , Mutação
11.
Microbiol Spectr ; 12(6): e0056024, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38647280

RESUMO

The continued emergence of Neisseria gonorrhoeae strains that express resistance to multiple antibiotics, including the last drug for empiric monotherapy (ceftriaxone), necessitates the development of new treatment options to cure gonorrheal infections. Toward this goal, we recently reported that corallopyronin A (CorA), which targets the switch region of the ß' subunit (RpoC) of bacterial DNA-dependent RNA polymerase (RNAP), has potent anti-gonococcal activity against a panel of multidrug-resistant clinical strains. Moreover, in that study, CorA could eliminate gonococcal infection of primary human epithelial cells and gonococci in a biofilm state. To determine if N. gonorrhoeae could develop high-level resistance to CorA in a single step, we sought to isolate spontaneous mutants expressing any CorA resistance phenotypes. However, no single-step mutants with high-level CorA resistance were isolated. High-level CorA resistance could only be achieved in this study through a multi-step pathway involving over-expression of the MtrCDE drug efflux pump and single amino acid changes in the ß and ß' subunits (RpoB and RpoC, respectively) of RNAP. Molecular modeling of RpoB and RpoC interacting with CorA was used to deduce how the amino acid changes in RpoB and RpoC could influence gonococcal resistance to CorA. Bioinformatic analyses of whole genome sequences of clinical gonococcal isolates indicated that the CorA resistance determining mutations in RpoB/C, identified herein, are very rare (≤ 0.0029%), suggesting that the proposed pathway for resistance is predictive of how this phenotype could potentially evolve if CorA is used therapeutically to treat gonorrhea in the future. IMPORTANCE: The continued emergence of multi-antibiotic-resistant strains of Neisseria gonorrhoeae necessitates the development of new antibiotics that are effective against this human pathogen. We previously described that the RNA polymerase-targeting antibiotic corallopyronin A (CorA) has potent activity against a large collection of clinical strains that express different antibiotic resistance phenotypes including when such gonococci are in a biofilm state. Herein, we tested whether a CorA-sensitive gonococcal strain could develop spontaneous resistance. Our finding that CorA resistance could only be achieved by a multi-step process involving over-expression of the MtrCDE efflux pump and single amino acid changes in RpoB and RpoC suggests that such resistance may be difficult for gonococci to evolve if this antibiotic is used in the future to treat gonorrheal infections that are refractory to cure by other antibiotics.


Assuntos
Antibacterianos , Proteínas de Bactérias , RNA Polimerases Dirigidas por DNA , Gonorreia , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Neisseria gonorrhoeae/enzimologia , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Antibacterianos/farmacologia , Humanos , Gonorreia/microbiologia , Gonorreia/tratamento farmacológico , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Farmacorresistência Bacteriana/genética , Mutação , Farmacorresistência Bacteriana Múltipla/genética , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Lactonas
12.
J Bacteriol ; 195(11): 2632-41, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23564168

RESUMO

NtrYX is a sensor-histidine kinase/response regulator two-component system that has had limited characterization in a small number of Alphaproteobacteria. Phylogenetic analysis of the response regulator NtrX showed that this two-component system is extensively distributed across the bacterial domain, and it is present in a variety of Betaproteobacteria, including the human pathogen Neisseria gonorrhoeae. Microarray analysis revealed that the expression of several components of the respiratory chain was reduced in an N. gonorrhoeae ntrX mutant compared to that in the isogenic wild-type (WT) strain 1291. These included the cytochrome c oxidase subunit (ccoP), nitrite reductase (aniA), and nitric oxide reductase (norB). Enzyme activity assays showed decreased cytochrome oxidase and nitrite reductase activities in the ntrX mutant, consistent with microarray data. N. gonorrhoeae ntrX mutants had reduced capacity to survive inside primary cervical cells compared to the wild type, and although they retained the ability to form a biofilm, they exhibited reduced survival within the biofilm compared to wild-type cells, as indicated by LIVE/DEAD staining. Analyses of an ntrX mutant in a representative alphaproteobacterium, Rhodobacter capsulatus, showed that cytochrome oxidase activity was also reduced compared to that in the wild-type strain SB1003. Taken together, these data provide evidence that the NtrYX two-component system may be a key regulator in the expression of respiratory enzymes and, in particular, cytochrome c oxidase, across a wide range of proteobacteria, including a variety of bacterial pathogens.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Genoma Bacteriano/genética , Neisseria gonorrhoeae/enzimologia , Nitrito Redutases/genética , Rhodobacter capsulatus/enzimologia , Proteínas de Bactérias/metabolismo , Biofilmes/crescimento & desenvolvimento , Colo do Útero/microbiologia , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Células Epiteliais/microbiologia , Feminino , Perfilação da Expressão Gênica , Regulação Enzimológica da Expressão Gênica , Gonorreia/microbiologia , Humanos , Viabilidade Microbiana , Neisseria gonorrhoeae/genética , Nitrito Redutases/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Oxirredutases/metabolismo , Oxigênio/metabolismo , Filogenia , RNA Bacteriano/genética , Rhodobacter capsulatus/genética , Deleção de Sequência
13.
J Org Chem ; 78(4): 1682-6, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23363387

RESUMO

The Pd-catalyzed TBHP-mediated Wacker-type oxidation of internal alkenes is reported. The reaction uses 2-(4,5-dihydro-2-oxazolyl)quinoline (Quinox) as ligand and TBHP(aq) as oxidant to deliver single ketone constitutional isomer products in a predictable fashion from electronically biased olefins. This methodology is showcased through its application on an advanced intermediate in the total synthesis of the antimalarial drug artemisinin.


Assuntos
Alcenos/química , Artemisininas/síntese química , Cetonas/química , Compostos Organometálicos/química , Oxazóis/química , Paládio/química , Quinolinas/química , Artemisininas/química , Catálise , Cetonas/síntese química , Ligantes , Estrutura Molecular , Oxirredução
14.
Microbiol Spectr ; 11(4): e0158323, 2023 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-37436144

RESUMO

Many bacterial surface proteins and carbohydrates are modified with phosphorylcholine (ChoP), which contributes to host mimicry and can also promote colonization and survival in the host. However, the ChoP biosynthetic pathways that are used in bacterial species that express ChoP have not been systematically studied. For example, the well-studied Lic-1 pathway is absent in some ChoP-expressing bacteria, such as Neisseria meningitidis and Neisseria gonorrhoeae. This raises a question as to the origin of the ChoP used for macromolecule biosynthesis in these species. In the current study, we used in silico analyses to identify the potential pathways involved in ChoP biosynthesis in genomes of the 26 bacterial species reported to express a ChoP-modified biomolecule. We used the four known ChoP biosynthetic pathways and a ChoP transferase as search terms to probe for their presence in these genomes. We found that the Lic-1 pathway is primarily associated with organisms producing ChoP-modified carbohydrates, such as lipooligosaccharide. Pilin phosphorylcholine transferase A (PptA) homologs were detected in all bacteria that express ChoP-modified proteins. Additionally, ChoP biosynthesis pathways, such as phospholipid N-methyltransferase (PmtA), phosphatidylcholine synthase (Pcs), or the acylation-dependent phosphatidylcholine biosynthesis pathway, which generate phosphatidylcholine, were also identified in species that produce ChoP-modified proteins. Thus, a major finding of this study is the association of a particular ChoP biosynthetic pathway with a cognate, target ChoP-modified surface factor; i.e., protein versus carbohydrate. This survey failed to identify a known biosynthetic pathway for some species that express ChoP, indicating that a novel ChoP biosynthetic pathway(s) may remain to be identified. IMPORTANCE The modification of bacterial surface virulence factors with phosphorylcholine (ChoP) plays an important role in bacterial virulence and pathogenesis. However, the ChoP biosynthetic pathways in bacteria have not been fully understood. In this study, we used in silico analysis to identify potential ChoP biosynthetic pathways in bacteria that express ChoP-modified biomolecules and found the association between a specific ChoP biosynthesis pathway and the cognate target ChoP-modified surface factor.


Assuntos
Vias Biossintéticas , Fosforilcolina , Fosforilcolina/metabolismo , Vias Biossintéticas/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Proteínas de Fímbrias/metabolismo , Transferases/metabolismo
15.
Trends Microbiol ; 31(7): 692-706, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36863982

RESUMO

Phosphorylcholine (ChoP) can be found in all life forms. Although this molecule was first thought to be uncommon in bacteria, it is now appreciated that many bacteria express ChoP on their surface. ChoP is usually attached to a glycan structure, but in some cases, it is added as a post-translational modification to proteins. Recent findings have demonstrated the role of ChoP modification and phase variation (ON/OFF switching) in bacterial pathogenesis. However, the mechanisms of ChoP synthesis are still unclear in some bacteria. Here, we review the literature and examine the recent developments in ChoP-modified proteins and glycolipids and of ChoP biosynthetic pathways. We discuss how the well-studied Lic1 pathway exclusively mediates ChoP attachment to glycans but not to proteins. Finally, we provide a review of the role of ChoP in bacterial pathobiology and the role of ChoP in modulating the immune response.


Assuntos
Bactérias , Fosforilcolina , Fosforilcolina/metabolismo , Bactérias/metabolismo , Polissacarídeos
16.
Open Forum Infect Dis ; 10(1): ofac661, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36655188

RESUMO

The US Neisseria meningitidis urethritis clade (US_NmUC) harbors gonococcal deoxyribonucleic acid alleles and causes gonorrhea-like urogenital tract disease. A large convenience sample of US_NmUC isolates (N = 122) collected between January 2015 and December 2019 in Columbus, Ohio demonstrated uniform susceptibility to antibiotics recommended for gonorrhea treatment and meningococcal chemoprophylaxis.

17.
Infect Immun ; 80(3): 1065-71, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22184419

RESUMO

NGO0579 is annotated copA in the Neisseria gonorrhoeae chromosome, suggesting that it encodes a cation-transporting ATPase specific for copper ions. Compared to wild-type cells, a copA mutant was more sensitive to killing by copper ions but not to other transition metals. The mutant also accumulated a greater amount of copper, consistent with the predicted role of CopA as a copper efflux pump. The copA mutant showed a reduced ability to invade and survive within human cervical epithelial cells, although its ability to form a biofilm on the surface of these cells was not significantly different from that of the wild type. In the presence of copper, the copA mutant exhibited increased sensitivity to killing by nitrite or nitric oxide. Therefore, we concluded that copper ion efflux catalyzed by CopA is linked to the nitrosative stress defense system of Neisseria gonorrhoeae. These observations suggest that copper may exert its effects as an antibacterial agent in the innate immune system via an interaction with reactive nitrogen species.


Assuntos
Proteínas de Bactérias/metabolismo , Cobre/toxicidade , Deleção de Genes , Neisseria gonorrhoeae/metabolismo , Estresse Fisiológico , Proteínas de Bactérias/genética , Células Cultivadas , Cobre/metabolismo , Células Epiteliais/microbiologia , Humanos , Viabilidade Microbiana/efeitos dos fármacos , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/genética , Óxido Nítrico/toxicidade , Nitritos/toxicidade , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
18.
Cell Microbiol ; 13(6): 885-96, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21371235

RESUMO

Expression of type IV pili by Neisseria gonorrhoeae plays a critical role in mediating adherence to human epithelial cells. Gonococcal pilin is modified with an O-linked glycan, which may be present as a di- or monosaccharide because of phase variation of select pilin glycosylation genes. It is accepted that bacterial proteins may be glycosylated; less clear is how the protein glycan may mediate virulence. Using primary, human, cervical epithelial (i.e. pex) cells, we now provide evidence to indicate that the pilin glycan mediates productive cervical infection. In this regard, pilin glycan-deficient mutant gonococci exhibited an early hyper-adhesive phenotype but were attenuated in their ability to invade pex cells. Our data further indicate that the pilin glycan was required for gonococci to bind to the I-domain region of complement receptor 3, which is naturally expressed by pex cells. Comparative, quantitative, infection assays revealed that mutant gonococci lacking the pilin glycan did not bind to the I-domain when it is in a closed, low-affinity conformation and cannot induce an active conformation to complement receptor 3 during pex cell challenge. To our knowledge, these are the first data to directly demonstrate how a protein-associated bacterial glycan may contribute to pathogenesis.


Assuntos
Células Epiteliais/microbiologia , Proteínas de Fímbrias/metabolismo , Antígeno de Macrófago 1/metabolismo , Neisseria gonorrhoeae/patogenicidade , Polissacarídeos/metabolismo , Aderência Bacteriana , Células Cultivadas , Endocitose , Feminino , Glicosilação , Humanos
19.
mBio ; 13(1): e0217721, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35012346

RESUMO

Transmission of HIV across the mucosal surface of the female reproductive tract to engage subepithelial CD4-positive T cells is not fully understood. Cervical epithelial cells express complement receptor 3 (CR3) (integrin αMß2 or CD11b/CD18). In women, the bacterium Neisseria gonorrhoeae uses CR3 to invade the cervical epithelia to cause cervicitis. We hypothesized that HIV may also use CR3 to transcytose across the cervical epithelia. Here, we show that HIV-1 strains bound with high affinity to recombinant CR3 in biophysical assays. HIV-1 bound CR3 via the I-domain region of the CR3 alpha subunit, CD11b, and binding was dependent on HIV-1 N-linked glycans. Mannosylated glycans on the HIV surface were a high-affinity ligand for the I-domain. Man5 pentasaccharide, representative of HIV N-glycans, could compete with HIV-1 for CR3 binding. Using cellular assays, we show that HIV bound to CHO cells by a CR3-dependent mechanism. Antibodies to the CR3 I-domain or to the HIV-1 envelope glycoprotein blocked the binding of HIV-1 to primary human cervical epithelial (Pex) cells, indicating that CR3 was necessary and sufficient for HIV-1 adherence to Pex cells. Using Pex cells in a Transwell model system, we show that, following transcytosis across an intact Pex cell monolayer, HIV-1 is able to infect TZM-bl reporter cells. Targeting the HIV-CR3 interaction using antibodies, mannose-binding lectins, or CR3-binding small-molecule drugs blocked HIV transcytosis. These studies indicate that CR3/Pex may constitute an efficient pathway for HIV-1 transmission in women and also demonstrate strategies that may prevent transmission via this pathway. IMPORTANCE In women, the lower female reproductive tract is the primary site for HIV infection. How HIV traverses the epithelium to infect CD4 T cells in the submucosa is ill-defined. Cervical epithelial cells have a protein called CR3 on their surface. We show that HIV-1 binds to CR3 with high affinity and that this interaction is necessary and sufficient for HIV adherence to, and transcytosis across, polarized, human primary cervical epithelial cells. This suggests a unique role for CR3 on epithelial cells in dually facilitating HIV-1 attachment and entry. The HIV-CR3 interaction may constitute an efficient pathway for HIV delivery to subepithelial lymphocytes following virus transmission across an intact cervical epithelial barrier. Strategies with potential to prevent transmission via this pathway are presented.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Cricetinae , Animais , Humanos , Feminino , Antígeno de Macrófago 1/metabolismo , HIV-1/metabolismo , Cricetulus , Células Epiteliais/microbiologia , Células CHO , Transcitose , Polissacarídeos/metabolismo
20.
mSphere ; 7(5): e0036222, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36094073

RESUMO

Gonorrhea remains a major global public health problem because of the high incidence of infection (estimated 82 million cases in 2020) and the emergence and spread of Neisseria gonorrhoeae strains resistant to previous and current antibiotics used to treat infections. Given the dearth of new antibiotics that are likely to enter clinical practice in the near future, there is concern that cases of untreatable gonorrhea might emerge. In response to this crisis, the World Health Organization (WHO), in partnership with the Global Antibiotic Research and Development Partnership (GARDP), has made the search for and development of new antibiotics against N. gonorrhoeae a priority. Ideally, these antibiotics should also be active against other sexually transmitted organisms, such as Chlamydia trachomatis and/or Mycoplasma genitalium, which are often found with N. gonorrhoeae as co-infections. Corallopyronin A is a potent antimicrobial that exhibits activity against Chlamydia spp. and inhibits transcription by binding to the RpoB switch region. Accordingly, we tested the effectiveness of corallopyronin A against N. gonorrhoeae. We also examined the mutation frequency and modes of potential resistance against corallopyronin A. We report that corallopyronin A has potent antimicrobial action against antibiotic-susceptible and antibiotic-resistant N. gonorrhoeae strains and could eradicate gonococcal infection of cultured, primary human cervical epithelial cells. Critically, we found that spontaneous corallopyronin A-resistant mutants of N. gonorrhoeae are exceedingly rare (≤10-10) when selected at 4× the MIC. Our results support pre-clinical studies aimed at developing corallopyronin A for gonorrheal treatment regimens. IMPORTANCE The high global incidence of gonorrhea, the lack of a protective vaccine, and the emergence of N. gonorrhoeae strains expressing resistance to currently used antibiotics demand that new treatment options be developed. Accordingly, we investigated whether corallopyronin A, an antibiotic which is effective against other pathogens, including C. trachomatis, which together with gonococci frequently cause co-infections in humans, could exert anti-gonococcal action in vitro and ex vivo, and potential resistance emergence. We propose that corallopyronin A be considered a potential future treatment option for gonorrhea because of its potent activity, low resistance development, and recent advances in scalable production.


Assuntos
Anti-Infecciosos , Coinfecção , Gonorreia , Humanos , Gonorreia/tratamento farmacológico , Gonorreia/prevenção & controle , Neisseria gonorrhoeae/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Chlamydia trachomatis , Anti-Infecciosos/farmacologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA