RESUMO
Carbonic anhydrases (CAs) from the pathogenic bacteria Nesseria gonorrhoeae and vancomycin-resistant enterococci (VRE) have recently been validated as antibacterial drug targets. Here we explored the inhibition of the α-CA from N. gonorrhoeae (α-NgCA), of α- and γ-class enzymes from Enterococcus faecium (α-EfCA and γ-EfCA) with a panel of aliphatic, heterocyclic and aryl-alkyl primary/secondary monothiocarbamates (MTCs). α-NgCA was inhibited in vitro with KIs ranging from 0.367 to 0.919 µM. The compounds inhibited the α-EfCA and γ-EfCA with KI ranges of 0.195-0.959 µM and of 0.149-1.90 µM, respectively. Some MTCs were also investigated for their inhibitory effects on the growth of clinically-relevant N. gonorrhoeae and VRE strains. No inhibitory effects on the growth of VRE were noted for all MTCs, whereas one compound (13) inhibited the growth N. gonorrhoeae strains at concentrations ranging from 16 to 64 µg/mL. This suggests that compound 13 may be a potential antibacterial agent against N. gonorrhoeae.
Assuntos
Anidrases Carbônicas , Enterococos Resistentes à Vancomicina , Bactérias , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologiaRESUMO
Gonococcal infections represent an urgent public health threat worldwide due to the increasing incidence of infections that has been accompanied by an increase in bacterial resistance to most antibiotics. This has resulted in a dwindling number of effective treatment options. Undoubtedly, there is a critical need to develop new, effective anti-gonococcal agents. In an effort to discover new anti-gonococcal therapeutics, we previously identified acetazolamide, a carbonic anhydrase inhibitor, as a novel inhibitor of Neisseria gonorrhoeae. Acetazolamide exhibited potent anti-gonococcal activity in vitro as it inhibited growth of strains of N. gonorrhoeae at concentrations that ranged from 0.5 to 4 µg/mL. The aim of this study was to investigate the in vivo efficacy of acetazolamide in a mouse model of N. gonorrhoeae genital tract infection. Compared to vehicle-treated mice, acetazolamide significantly reduced the gonococcal burden by 90% in the vagina of infected mice after three days of treatment. These results indicate that acetazolamide warrants further investigation as a promising treatment option to supplement the limited pipeline of anti-gonococcal therapeutics.
Assuntos
Gonorreia , Acetazolamida/farmacologia , Acetazolamida/uso terapêutico , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Modelos Animais de Doenças , Feminino , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Camundongos , Neisseria gonorrhoeaeRESUMO
Recently, inorganic anions and sulphonamides, two of the main classes of zinc-binding carbonic anhydrase inhibitors (CAIs), were investigated for inhibition of the α-class carbonic anhydrase (CA, EC 4.2.1.1) from Neisseria gonorrhoeae, NgCA. As an extension to our previous studies, we report that dithiocarbamates (DTCs) derived from primary or secondary amines constitute a class of efficient inhibitors of NgCA. KIs ranging between 83.7 and 827 nM were measured for a series of 31 DTCs that incorporated various aliphatic, aromatic, and heterocyclic scaffolds. A subset of DTCs were selected for antimicrobial testing against N. gonorrhoeae, and three molecules displayed minimum inhibitory concentration (MIC) values less than or equal to 8 µg/mL. As NgCA was recently validated as an antibacterial drug target, the DTCs may lead to development of novel antigonococcal agents.
Assuntos
Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Neisseria gonorrhoeae/efeitos dos fármacos , Tiocarbamatos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neisseria gonorrhoeae/enzimologia , Relação Estrutura-Atividade , Tiocarbamatos/síntese química , Tiocarbamatos/químicaRESUMO
Neisseria gonorrhoeae is a high-priority pathogen of concern due to the growing prevalence of resistance development against approved antibiotics. Herein, we report the anti-gonococcal activity of ethoxzolamide, the FDA-approved human carbonic anhydrase inhibitor. Ethoxzolamide displayed an MIC50, against a panel of N. gonorrhoeae isolates, of 0.125 µg/mL, 16-fold more potent than acetazolamide, although both molecules exhibited almost similar potency against the gonococcal carbonic anhydrase enzyme (NgCA) in vitro. Acetazolamide displayed an inhibition constant (Ki) versus NgCA of 74 nM, while Ethoxzolamide's Ki was estimated to 94 nM. Therefore, the increased anti-gonococcal potency of ethoxzolamide was attributed to its increased permeability in N. gonorrhoeae as compared to that of acetazolamide. Both drugs demonstrated bacteriostatic activity against N. gonorrhoeae, exhibited post-antibiotic effects up to 10 hours, and resistance was not observed against both. Taken together, these results indicate that acetazolamide and ethoxzolamide warrant further investigation for translation into effective anti-N. gonorrhoeae agents.
Assuntos
Acetazolamida/farmacologia , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Etoxzolamida/farmacologia , Neisseria gonorrhoeae/efeitos dos fármacos , Acetazolamida/síntese química , Acetazolamida/química , Antibacterianos/síntese química , Antibacterianos/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Etoxzolamida/síntese química , Etoxzolamida/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neisseria gonorrhoeae/enzimologia , Relação Estrutura-Atividade , Estados Unidos , United States Food and Drug AdministrationRESUMO
Vancomycin-resistant enterococci (VRE), consisting of pathogenic Enterococcus faecalis and E. faecium, is a leading cause of hospital-acquired infections (HAIs). We recently repurposed the FDA-approved human carbonic anhydrase (CA) inhibitor acetazolamide (AZM) against VRE agent with the likely mechanism of action for the molecules being inhibition of one, or both, of the bacterial CA isoforms expressed in VRE. To elucidate how inhibitor binding to the enzymes relates to MIC, we further characterised the inhibition constants (Ki) against the E. faecium α-CA (Efα-CA) and γ-CA (Efγ-CA), as well as against human CA I (hCAI) and human CA II (hCAII) to assess selectivity. We have also utilised homology modelling and molecular dynamics (MD) simulations to gain a better understanding of the potential interactions the molecules are making with the targets. In this paper, we elaborate on the SAR for the AZM analogs as it pertains to MIC and Ki for each CA.
Assuntos
Anidrases Carbônicas , Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Acetazolamida , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/química , Enterococcus faecalis , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Vancomicina/farmacologiaRESUMO
A new class of alkynyl isoquinoline antibacterial compounds, synthesized via Sonogashira coupling, with strong bactericidal activity against a plethora of Gram-positive bacteria including methicillin- and vancomycin-resistant Staphylococcus aureus (S. aureus) strains is presented. HSN584 and HSN739, representative compounds in this class, reduce methicillin-resistant S. aureus (MRSA) load in macrophages, whilst vancomycin, a drug of choice for MRSA infections, was unable to clear intracellular MRSA. Additionally, both HSN584 and HSN739 exhibited a low propensity to develop resistance. We utilized comparative global proteomics and macromolecule biosynthesis assays to gain insight into the alkynyl isoquinoline mechanism of action. Our preliminary data show that HSN584 perturb S. aureus cell wall and nucleic acid biosynthesis. The alkynyl isoquinoline moiety is a new scaffold for the development of potent antibacterial agents against fatal multidrug-resistant Gram-positive bacteria.
Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bactérias , Isoquinolinas/farmacologia , Testes de Sensibilidade Microbiana , Proteoma , Staphylococcus aureusRESUMO
Vancomycin-resistant enterococci (VRE) represent a major public health threat that requires the development of new therapeutics. In the present study, acetazolamide (AZM) was evaluated against enterococci. It inhibited different enterococcal strains tested at clinically achievable concentrations. Moreover, AZM outperformed linezolid, the drug of choice for VRE infections, in two in vivo VRE mouse models-murine colonization-reduction and VRE septicemia. Collectively, these results indicate that AZM warrants consideration as a promising treatment option for VRE infections.
Assuntos
Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Acetazolamida/farmacologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Linezolida/farmacologia , CamundongosRESUMO
The Centers for Disease Control and Prevention (CDC) recognizes Neisseria gonorrhoeae as an urgent-threat Gram-negative bacterial pathogen. Additionally, resistance to frontline treatment (dual therapy with azithromycin and ceftriaxone) has led to the emergence of multidrug-resistant N. gonorrhoeae, which has caused a global health crisis. The drug pipeline for N. gonorrhoeae has been severely lacking as new antibacterial agents have not been approved by the FDA in the last twenty years. Thus, there is a need for new chemical entities active against drug-resistant N. gonorrhoeae. Trifluoromethylsulfonyl (SO2CF3), trifluoromethylthio (SCF3), and pentafluorosulfanyl (SF5) containing N-(1,3,4-oxadiazol-2-yl)benzamides are novel compounds with potent activities against Gram-positive bacterial pathogens. Here, we report the discovery of new N-(1,3,4-oxadiazol-2-yl)benzamides (HSGN-237 and -238) with highly potent activity against N. gonorrhoeae. Additionally, these new compounds were shown to have activity against clinically important Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Listeria monocytogenes (minimum inhibitory concentrations (MICs) as low as 0.25 µg/mL). Both compounds were highly tolerable to human cell lines. Moreover, HSGN-238 showed an outstanding ability to permeate across the gastrointestinal tract, indicating it would have a high systemic absorption if used as an anti-gonococcal therapeutic.
Assuntos
Antibacterianos/farmacologia , Benzamidas/farmacologia , Neisseria gonorrhoeae/efeitos dos fármacos , Oxidiazóis/farmacologia , Antibacterianos/uso terapêutico , Benzamidas/síntese química , Benzamidas/química , Benzamidas/uso terapêutico , Linhagem Celular , Gonorreia/tratamento farmacológico , Humanos , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxidiazóis/síntese química , Oxidiazóis/química , Oxidiazóis/uso terapêuticoRESUMO
Clostridioides difficile, the leading cause of nosocomial infections, is an urgent health threat worldwide. The increased incidence and severity of disease, the high recurrence rates, and the dearth of effective anticlostridial drugs have created an urgent need for new therapeutic agents. In an effort to discover new drugs for the treatment of Clostridioides difficile infections (CDIs), we investigated a panel of FDA-approved antiparasitic drugs against C. difficile and identified diiodohydroxyquinoline (DIHQ), an FDA-approved oral antiamoebic drug. DIHQ exhibited potent activity against 39 C. difficile isolates, inhibiting growth of 50% and 90% of these isolates at concentrations of 0.5 µg/ml and 2 µg/ml, respectively. In a time-kill assay, DIHQ was superior to vancomycin and metronidazole, reducing a high bacterial inoculum by 3 log10 within 6 h. Furthermore, DIHQ reacted synergistically with vancomycin and metronidazole against C. difficilein vitro. Moreover, at subinhibitory concentrations, DIHQ was superior to vancomycin and metronidazole in inhibiting two key virulence factors of C. difficile, toxin production and spore formation. Additionally, DIHQ did not inhibit the growth of key species that compose the host intestinal microbiota, such as Bacteroides, Bifidobacterium, and Lactobacillus spp. Collectively, our results indicate that DIHQ is a promising anticlostridial drug that warrants further investigation as a new therapeutic for CDIs.
Assuntos
Clostridioides difficile , Infecções por Clostridium , Preparações Farmacêuticas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Clostridioides , Infecções por Clostridium/tratamento farmacológico , Reposicionamento de Medicamentos , Humanos , IodoquinolRESUMO
A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) synthesized via allylboration or allylindation reactions were screened against methicillin-resistant Staphylococcus aureus (MRSA) USA300. Unlike natural AMGBLs, such as parthenolide, synthetic analogs bearing aryl moieties at the ß- and γ-positions are potent against MRSA. The most potent molecules were comparable to vancomycin and linezolid, the drugs of the last resort for MRSA infections, in their effectiveness with minimum inhibitory concentrations (MICs) ranging from 3.0 to 5.2⯵M. These lactones also exhibited potent antibacterial activity against other clinically important multidrug-resistant Gram-positive bacteria (except enterococci), while also showing high tolerability to mammalian cells. Several of these molecules surpassed vancomycin in their rapid killing of the high MRSA inoculum (2â¯h vs 12â¯h) in a standard time-kill kinetics assay, with compounds 1l and 1m significantly reducing the intracellular burden of MRSA by about 98-99%, at low concentrations. Additionally, the compounds surpassed vancomycin in inhibiting staphylococcal protease production, indicating that synthetic methylene lactones warrant further investigations as promising anti-MRSA candidates.
Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/farmacologia , Inibidores Enzimáticos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , 4-Butirolactona/síntese química , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Linhagem Celular , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/microbiologia , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
The ongoing prevalence of multidrug-resistant bacterial pathogens requires the development of new effective antibacterial agents. In this study, two series of halogenated 1,3-thiazolidin-4-ones were synthesized and characterized. All the synthesized thiazolidinone derivatives were evaluated for their antimicrobial activity. Biological screening of the tested compounds revealed the antibacterial activity of the chlorinated thiazolidinones 4a, 4b and 4c against Escherichia coli TolC-mutant, with MIC values of 16 µg/mL. A combination of a sub-inhibitory concentration of colistin (0.25 × MIC) with compounds 4a, 4b or 4c showed antibacterial activity against different Gram-negative bacteria (MICs = 4-16 µg/mL). Interestingly, compounds 4a, 4b and 4c were not cytotoxic to murine fibroblasts and Caco-2 cells. The chlorinated thiazolidinone derivative 16d demonstrated a bacteriostatic activity against a panel of pathogenic Gram-positive bacteria, including clinical isolates of methicillin and vancomycin-resistant Staphylococcus aureus, Listeria monocytogenes and multidrug-resistant Staphylococcus epidermidis (MICs = 8 - 64 µg/mL), with no cytotoxicity against both Caco-2 and L929 cells. Compound 16d was superior to vancomycin in disruption of the pre-formed MRSA biofilm. Furthermore, the three fluorinated thiazolidinone derivatives 26c, 30c and 33c showed a hindrance to hemolysin activity, without cytotoxicity against L929 cells.
Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Animais , Antibacterianos/síntese química , Antibacterianos/química , Células CACO-2 , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-AtividadeRESUMO
The widespread use of antibiotics has significantly increased the number of resistant bacteria, which has also increased the urgency of rapid bacterial detection and profiling their antibiotic response. Current clinical methods for antibiotic susceptibility testing (AST) rely on culture and require at least 16 to 24 h to conduct. Therefore, there is an urgent need for a rapid method that can test the susceptibility of bacteria in a culture-free manner. Here we demonstrate a rapid AST method by monitoring the glucose metabolic activity of live bacteria at the single-cell level with hyperspectral stimulated Raman scattering (SRS) imaging. Using vancomycin-susceptible and -resistant enterococci E. faecalis as models, we demonstrate that the metabolic uptake of deuterated glucose in a single living bacterium can be quantitatively monitored via hyperspectral SRS imaging. Remarkably, the metabolic activity of susceptible bacteria responds differently to antibiotics from the resistant strain within only 0.5 h from the addition of antibiotics. Therefore, bacterial susceptibility and the minimum inhibitory concentration (MIC) of antibiotics can be determined within one cell cycle. Our metabolic imaging method is applicable to other bacteria species including E. coli, K. Pneumoniae, and S. aureus as well as different antibiotics, regardless of their mechanisms of inhibiting or killing bacteria.
Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Glucose/metabolismo , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Testes de Sensibilidade Microbiana/métodos , Análise Espectral Raman/métodos , Vancomicina/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/metabolismo , Infecções Bacterianas/tratamento farmacológico , Farmacorresistência Bacteriana , Enterococcus faecalis/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Humanos , Análise de Célula Única/métodos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/metabolismoRESUMO
Effective molecular strategies are needed to target pathogenic bacteria that thrive and proliferate within mammalian cells, a sanctuary inaccessible to many therapeutics. Herein, we present a class of cationic amphiphilic polyproline helices (CAPHs) with a rigid placement of the cationic moiety on the polyproline helix and assess the role of configuration of the unnatural proline residues making up the CAPHs. By shortening the distance between the guanidinium side chain and the proline backbone of the agents, a notable increase in cellular uptake and antibacterial activity was observed, whereas changing the configuration of the moieties on the pyrrolidine ring from cis to trans resulted in more modest increases. When the combination of these two activities was evaluated, the more rigid CAPHs were exceptionally effective at eradicating intracellular methicillin-resistant Staphylococcus aureus (MRSA) and Salmonella infections within macrophages, significantly exceeding the clearance with the parent CAPH.
Assuntos
Antibacterianos , Staphylococcus aureus Resistente à Meticilina , Peptídeos , Antibacterianos/farmacologia , Antibacterianos/química , Animais , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Peptídeos/química , Peptídeos/farmacologia , Macrófagos/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Cátions/química , Cátions/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Humanos , Infecções por Salmonella/microbiologia , Infecções por Salmonella/tratamento farmacológico , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologiaRESUMO
Drug-resistant gonorrhea is caused by the bacterial pathogen Neisseria gonorrhoeae, for which there is no recommended oral treatment. We have demonstrated that the FDA-approved human carbonic anhydrase inhibitor ethoxzolamide potently inhibits N. gonorrhoeae; however, is not effective at reducing N. gonorrhoeae bioburden in a mouse model. Thus, we sought to optimize the pharmacokinetic properties of the ethoxzolamide scaffold. These efforts resulted in analogs with improved activity against N. gonorrhoeae, increased metabolic stability in mouse liver microsomes, and improved Caco-2 permeability compared to ethoxzolamide. Improvement in these properties resulted in increased plasma exposure in vivo after oral dosing. Top compounds were investigated for in vivo efficacy in a vaginal mouse model of gonococcal genital tract infection, and they significantly decreased the gonococcal burden compared to vehicle and ethoxzolamide controls. Altogether, results from this study provide evidence that ethoxzolamide-based compounds have the potential to be effective oral therapeutics against gonococcal infection.
RESUMO
The structure-activity relationship of a new tert-butylphenylthiazole series, with a pyrimidine linker, was investigated. We wished to expand knowledge of this novel class of antibiotics by generating 21 new derivatives bearing ≥2 heteroatoms in their side chains. Their activity was examined against isolates of methicillin-resistant Staphylococcus aureus (MRSA), Clostridium difficile, Escherichia coli, Neisseria gonorrhoeae, and Candida albicans. Two compounds with 1,2-diaminocyclohexane as a nitrogenous side chain showed promising activity against the highly infectious MRSA USA300 strain, with a minimum inhibitory concentration (MIC) of 4 µg mL-1. One of these two compounds demonstrated potent activity against C. difficile, with a MIC of 4 µg mL-1. Moderate activities against a C. difficile strain with a MIC of 8 µg mL-1 were noted. Some new compounds possessed antifungal activity against a wild fluconazole-resistant C. albicans strain, with MIC values of 4-16 µg mL-1. ADME and metabolism-simulation studies were performed for the most promising compound and compared with lead compounds. Our results revealed that one compound possessed greater penetration of bacterial membranes and metabolic resistance, which aided a longer duration of action against MRSA.
RESUMO
The development of antibacterial drugs with new mechanisms of action is crucial in combating the rise of antibiotic-resistant infections. Bacterial carbonic anhydrases (CAs, EC 4.2.1.1) have been validated as promising antibacterial targets against pathogens such as Helicobacter pylori, Neisseria gonorrhoeae, and vancomycin-resistant enterococci. A multitarget strategy is proposed to design penicillin-based CA inhibitor hybrids for tackling resistance by targeting multiple bacterial pathways, thereby resensitizing drug-resistant strains to clinical antibiotics. The sulfonamide derivatives potently inhibited the CAs from N. gonorrhoeae and Escherichia coli with KI values in the range of 7.1-617.2 nM. Computational simulations with the main penicillin-binding protein (PBP) of N. gonorrhoeae indicated that these hybrid derivatives maintained the mechanism of action of the lead ß-lactams. A subset of derivatives showed potent PBP-related antigonococcal effects against multidrug-resistant N. gonorrhoeae strains, with several compounds significantly outperforming both the lead ß-lactam and CA inhibitor drugs (MIC values in the range 0.25 to 0.5 µg/mL).
Assuntos
Antibacterianos , Inibidores da Anidrase Carbônica , Anidrases Carbônicas , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/enzimologia , Inibidores da Anidrase Carbônica/farmacologia , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/síntese química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Anidrases Carbônicas/metabolismo , Penicilinas/farmacologia , Penicilinas/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Relação Estrutura-Atividade , Humanos , Sulfonamidas/farmacologia , Sulfonamidas/química , Sulfonamidas/síntese química , Estrutura Molecular , Escherichia coli/efeitos dos fármacos , Escherichia coli/enzimologiaRESUMO
The rapid occurrence of gonococcal resistance to all classes of antibiotics could lead to untreatable gonorrhea. Thus, development of novel anti-Neisseria gonorrhoeae drugs is urgently needed. Neisseria gonorrhoeae FA1090 is the most used in gonococcal infection mouse models because of its natural resistance to streptomycin. Streptomycin inhibits the urogenital commensal flora that permits gonococcal colonization. However, this strain is drug-susceptible and cannot be used to investigate the efficacy of novel agents against multidrug-resistant N. gonorrhoeae. Hence, to test the in vivo efficacy of new therapeutics against N. gonorrhoeae resistant to the frontline antibiotics, azithromycin, or ceftriaxone, we constructed streptomycin-resistant mutants of N. gonorrhoeae CDC-181 (azithromycin-resistant) and WHO-X (ceftriaxone-resistant). We identified the inoculum size needed to successfully colonize mice. Both mutants, CDC-181-rpsLA128G and WHO-X-rpsLA128G, colonized the genital tract of mice for 14 days with 100% colonization observed for at least 7 days. CDC-181-rpsLA128G demonstrated better colonization of the murine genital tract compared to WHO-X-rpsLA128G. Lower inoculum of WHO-X-rpsLA128G (105 and 106 CFU) colonized mice better than higher inoculum. Overall, our results indicate that CDC-181-rpsLA128G and WHO-X-rpsLA128G can colonize the lower genital tract of mice and are suitable to be used in mouse models to investigate the efficacy of antigonococcal agents.
Assuntos
Gonorreia , Neisseria gonorrhoeae , Animais , Camundongos , Feminino , Ceftriaxona , Azitromicina/farmacologia , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Estreptomicina , Modelos Animais de DoençasRESUMO
Vancomycin-resistant enterococci (VRE), Enterococcus faecium and Enterococcus faecalis, are high-priority drug-resistant pathogens in need of new therapeutic approaches. VRE originate in the gastrointestinal tract of carriers and can lead to more problematic downstream infections in the healthcare setting. Having a carrier of VRE admitted into a healthcare setting increases the risk to other patients for acquiring an infection. One strategy to eliminate the downstream infections is decolonization of VRE from carriers. Here, we report the activity of a set of carbonic anhydrase inhibitors in the in vivo VRE gastrointestinal decolonization mouse model. The molecules encompass a range of antimicrobial potency and intestinal permeability, and these factors were shown to influence the in vivo efficacy for VRE gut decolonization. Overall, carbonic anhydrase inhibitors exhibited superior VRE decolonization efficacy compared to the current drug of choice, linezolid.
RESUMO
INTRODUCTION AND OBJECTIVES: The emergence of Candida auris has created a global health challenge. Azole antifungals are the most affected antifungal class because of the extraordinary capability of C. auris to develop resistance against these drugs. Here, we used a combinatorial therapeutic approach to sensitize C. auris to azole antifungals. METHODS AND RESULTS: We have demonstrated the capability of the HIV protease inhibitors lopinavir and ritonavir, at clinically relevant concentrations, to be used with azole antifungals to treat C. auris infections both in vitro and in vivo. Both lopinavir and ritonavir exhibited potent synergistic interactions with the azole antifungals, particularly with itraconazole against 24/24 (100%) and 31/34 (91%) of tested C. auris isolates, respectively. Furthermore, ritonavir significantly interfered with the fungal efflux pump, resulting in a significant increase in Nile red fluorescence by 44%. In a mouse model of C. auris systemic infection, ritonavir boosted the activity of lopinavir to work synergistically with fluconazole and itraconazole and significantly reduced the kidney fungal burden by a 1.2 log (â¼94%) and 1.6 log (â¼97%) CFU, respectively. CONCLUSION: Our results urge further comprehensive assessment of azoles and HIV protease inhibitors as a novel drug regimen for the treatment of serious invasive C. auris infections.
Assuntos
Candidíase , Inibidores da Protease de HIV , Animais , Camundongos , Antifúngicos/farmacologia , Antifúngicos/uso terapêutico , Ritonavir/uso terapêutico , Azóis/farmacologia , Azóis/uso terapêutico , Itraconazol/farmacologia , Itraconazol/uso terapêutico , Lopinavir/farmacologia , Lopinavir/uso terapêutico , Candida auris , Inibidores da Protease de HIV/farmacologia , Inibidores da Protease de HIV/uso terapêutico , Candidíase/tratamento farmacológico , Candidíase/microbiologia , Testes de Sensibilidade Microbiana , Farmacorresistência FúngicaRESUMO
With the continuous and alarming threat of exhausting the current antimicrobial arsenals, efforts are urgently needed to develop new effective ones. In this study, the antibacterial efficacy of a set of structurally related acetylenic-diphenylurea derivatives carrying the aminoguanidine moiety was tested against a panel of multidrug-resistant Gram-positive clinical isolates. Compound 18 was identified with a superior bacteriological profile than the lead compound I. Compound 18 demonstrated an excellent antibacterial profile in vitro: low MIC values, extended post-antibiotic effect, refractory ability to resistance development upon extended repeated exposure, and high tolerability towards mammalian cells. Finally, when assessed in a MRSA skin infection animal model, compound 18 showed considerable healing and less inflammation, decrease in the bacterial loads in skin lesions, and it surpassed fusidic acid in controlling the systemic dissemination of S. aureus. Collectively, compound 18 represents a promising lead anti-MRSA agent that merits further investigation for the development of new anti-staphylococcal therapeutics.