Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 5.689
Filtrar
1.
Mater Sci Eng C Mater Biol Appl ; 128: 112292, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474843

RESUMO

The ever-growing threat of drug-resistant pathogens and their biofilms based persistent, chronic infections has created an urgent call for new strategies to deal with multidrug resistant bacteria (MDR). Near-infrared (NIR) laser-induced photothermal treatment (PTT) of gold nanorods (AuNRs) disinfects microbes by local heating with low possibility to develop resistant. However, PTT disinfection strategy of AuNRs alone shows less efficiency in killing multidrug resistant strains (i.e. Methicillin-resistant Staphylococcus aureus, MRSA) and their matured biofilms. Herein, a novel synergistic chemo-photothermal integrated antimicrobial platform (P(Cip-b-CB)-AuNRs) was fabricated which show enhanced killing efficiency against MRSA in both planktonic and biofilm phenotypes. Polymethacrylate copolymers with pendant ciprofloxacin (Cip) and the carboxyl betaine groups (P(Cip-b-CB)) were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. P(Cip-b-CB) was decorated onto AuNRs via gold-thiol bond which resulted in AuNRs with acidic-induced surface charge-switchable activities and lipase triggered Cip release properties (P(Cip-b-CB)-AuNRs). The lower pH value and overexpress of lipase are characteristics for microenvironment of microbial infections and their biofilms, which ensure the targeting on, penetration into and on-demand release of Cip from the nanocomposites in bacterial infection sites and their biofilms. The bacterial cell membrane was disrupt by photothermal therapy which could improve its permeability and sensitivity to antibiotics, meanwhile lipase-triggered release of Cip ensures a high concentration of antibiotics at the site of bacterial infection. Besides their NIR induced PTT disinfection activities, the increased local temperature generated by NIR light irradiation accelerated Cip release which further enhanced the antibacterial efficiency, leading to synergistic antibacterial activities of chemo-photothermal therapy. Taken together, the designed synergistic chemo-photothermal integrated antimicrobial platform is a promising antibacterial agent for fighting MDR bacterial infections and their biofilms.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Nanotubos , Preparações Farmacêuticas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Ciprofloxacina/farmacologia , Ouro , Concentração de Íons de Hidrogênio
2.
Molecules ; 26(15)2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34361815

RESUMO

Myristicafragrans Houtt. (Nutmeg) is a widely known folk medicine across several parts of Asia, particularly used in antimicrobial treatment. Bacterial resistance involves the expression of efflux pump systems (chromosomal norA and mepA) in methicillin-resistant Staphylococcus aureus (MRSA). Crude extract (CE) and essential oil (EO) obtained from nutmeg were applied as efflux pump inhibitors (EPIs), thereby enhancing the antimicrobial activity of the drugs they were used in. The major substances in CE and EO, which function as EPIs, in a descending order of % peak area include elemicin, myristicin, methoxyeugenol, myristicin, and asarone. Here, we investigated whether the low amount of CE and EO used as EPIs was sufficient to sensitize MRSA killing using the antibiotic ciprofloxacin, which acts as an efflux system. Interestingly, synergy between ciprofloxacin and CE or EO revealed the most significant viability of MRSA, depending on norA and mepA, the latter being responsible for EPI function of EO. Therefore, CE and EO obtained from nutmeg can act as EPIs in combination with substances that act as efflux systems, thereby ensuring that the MRSA strain is susceptible to antibiotic treatment.


Assuntos
Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Myristica/química , Óleos Voláteis/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , Derivados de Alilbenzenos/farmacologia , Ciprofloxacina/farmacologia , Dioxolanos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sementes/química , Infecções Estafilocócicas/microbiologia
3.
Mikrobiyol Bul ; 55(3): 285-299, 2021 Jul.
Artigo em Turco | MEDLINE | ID: mdl-34416797

RESUMO

The most realistic approach in recent years is researching the resistance inhibition rather than synthesizing new compounds. In this study, we aimed to determine i) the effect of phenylalanine-argininebeta-naphthylamide (PAßN), on minimum inhibition concentrations (MICs) of ciprofloxacin (CIP), ii) to obtain the CIP+PAßN concentration that inhibits CIP resistance and iii) to show that this inhibition is caused by the effect of PAßN on the expression of efflux pump (EF) system genes. Acinetobacter baumannii isolates were collected from Trakya University Hospital. In 67 isolates determined to be resistant to CIP, CIP susceptibility was investigated in presence of PAßN once again. Isolates determined to have four or more fold decrease in ciprofloxacin MIC values were included in checkerboard assay and quantitative real-time reverse transcriptase polymerase chain reaction (qrRT-PCR). Fractional inhibition concentrations (FICs) were calculated through the PAßN concentrations that inhibit ciprofloxacin resistance, by the checkerboard assay results. With the combination of CIP+PAßN, the effect of the concentrations at which inhibition occurs, to the expression levels of EF system genes (adeA, adeB, adeR, adeS, adeF, adeG, adeH, adeL) was investigated by qrRT-PCR. By the checker board assay, a synergistic effect was determined between PAßN and CIP in 11 isolates, while in other isolates the effect was determined to be additive. In some isolates resistant to CIP, CIP + PAßN combination inhibited the resistance and increased CIP susceptibility. In the presence of 25 mg/L and 100 mg/L PAßN, 22 (32.83%) and 27 (40.3%) of 67 isolates became sensitive to CIP, respectively. In seven isolates, 12.5 µg/ml PAßN concentration eliminated CIP resistance by decreasing CIP MIC value to 1 µg/ml. Also, in one isolate the MIC value was 0.5 µg/ml in the presence of 25 µg/ml PAßN and 1 µg/ml in the presence of 1.5625 µg/ml PAßN. After analyzing the expression levels of EF genes (adeA, adeB, adeC, adeF, adeG, adeH, adeL, adeR and adeS) by the qRt-PCR method, it was determined that with the addition of PAßN to media containing CIP, the expression levels of the genes decreased (p<0.05). The aim of the study has been achieved with the results obtained. These results highlighted the importance of research on the inhibition of resistance, as well as the synthesis of new antimicrobial compounds. Combined use of inhibitors and antibiotics should be considered as an alternative treatment method. Thus, existing antibiotics can be included in the treatment again, saving time and money. It will be possible to use these findings in further studies to elucidate the mechanism of action of new inhibitor candidate compounds and associate them with the expression of DAP genes, also by investigating mutations in the regulatory gene regions in isolates with over-expression levels.


Assuntos
Acinetobacter baumannii , Acinetobacter baumannii/genética , Arginina , Ciprofloxacina/farmacologia , Dipeptídeos , Humanos , Proteínas de Membrana Transportadoras , Testes de Sensibilidade Microbiana , Naftalenos , Fenilalanina
4.
J Med Microbiol ; 70(8)2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34356003

RESUMO

Introduction. Fluoroquinolone (FQ) resistant Salmonella are classified as high priority pathogens by WHO. FQ resistance among Salmonella Typhi has emerged rapidly and is predominantly mediated by mutations in the topoisomerase genes gyrA, and parC. Mutations in GyrA result in classical FQ resistance (DCS-NAR) i.e. decreased susceptibility to ciprofloxacin (MIC of 0.12 to 0.5 µg ml-1) (DCS) and resistance to nalidixic acid (NAR). Previously a nalidixic acid disc test was proposed for detection of DCS. Recently isolates with non-classical FQ resistance caused by plasmid-mediated quinolone resistance (PMQR) and mutations in GyrB have emerged. These mechanisms also result in DCS but are nalidixic acid susceptible (NAS) and thus pose diagnostic challenges. CLSI and EUCAST have recommended use of 5 µg pefloxacin discs for detection of DCS in Salmonella.Hypothesis. The CLSI and EUCAST recommendations for use of 5 µg pefloxacin for detection of DCS has not been validated on typhoidal Salmonella and resistance mediated by GyrB mutation in Salmonella species.Aim. The aim of the present study was to validate the performance of the 5 µg pefloxacin discs to detect isolates of S. Typhi with DCS with special reference to GyrB mutations.Methodology. A total of 180 clinical isolates of Salmonella Typhi (2005-2014) were investigated for genetic mechanisms of resistance. Zone diameters for nalidixic acid (30µg), ciprofloxacin (5µg) and pefloxacin (5µg) and minimum inhibitory concentration (MIC) for ciprofloxacin were determined using CLSI guidelines. Performance of the three discs was evaluated to detect FQ resistance in S. Typhi.Results. Topoisomerase mutations in GyrB +/ ParC and GyrB were detected in 112 and 34 isolates respectively. Different mutations have a varied effect on the MIC for ciprofloxacin. The current breakpoints for susceptible (≤0.06 µg ml-1) and non-susceptible (≥0.125 µg ml-1), failed to detect all isolates with a resistance mechanism. Performance of both ciprofloxacin and pefloxacin discs were excellent compared to nalidixic acid in differentiating isolates with non-classical resistance mediated by GyrB from wild-type.Conclusion. The pefloxacin disc can be used to detect FQ resistance among S. Typhi. This is the first report of validation of pefloxacin for detection of FQ resistance in S. Typhi mediated by GyrB mutation.


Assuntos
DNA Girase/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Fluoroquinolonas/farmacologia , Pefloxacina/farmacologia , Salmonella typhi/efeitos dos fármacos , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , DNA Topoisomerase IV/genética , Farmacorresistência Bacteriana/genética , Humanos , Testes de Sensibilidade Microbiana , Mutação , Ácido Nalidíxico/farmacologia , Salmonella typhi/genética , Salmonella typhi/isolamento & purificação , Inibidores da Topoisomerase II/farmacologia , Febre Tifoide/microbiologia
5.
Front Cell Infect Microbiol ; 11: 694789, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34249781

RESUMO

Pseudomonas aeruginosa is a metabolically versatile opportunistic pathogen capable of infecting distinct niches of the human body, including skin wounds and the lungs of cystic fibrosis patients. Eradication of P. aeruginosa infection is becoming increasingly difficult due to the numerous resistance mechanisms it employs. Adaptive resistance is characterized by a transient state of decreased susceptibility to antibiotic therapy that is distinct from acquired or intrinsic resistance, can be triggered by various environmental stimuli and reverted by removal of the stimulus. Further, adaptive resistance is intrinsically linked to lifestyles such as swarming motility and biofilm formation, both of which are important in infections and lead to multi-drug adaptive resistance. Here, we demonstrated that NtrBC, the master of nitrogen control, had a selective role in host colonization and a substantial role in determining intrinsic resistance to ciprofloxacin. P. aeruginosa mutant strains (ΔntrB, ΔntrC and ΔntrBC) colonized the skin but not the respiratory tract of mice as well as WT and, unlike WT, could be reduced or eradicated from the skin by ciprofloxacin. We hypothesized that nutrient availability contributed to these phenomena and found that susceptibility to ciprofloxacin was impacted by nitrogen source in laboratory media. P. aeruginosa ΔntrB, ΔntrC and ΔntrBC also exhibited distinct host interactions, including modestly increased cytotoxicity toward human bronchial epithelial cells, reduced virulence factor production and 10-fold increased uptake by macrophages. These data might explain why NtrBC mutants were less adept at colonizing the upper respiratory tract of mice. Thus, NtrBC represents a link between nitrogen metabolism, adaptation and virulence of the pathogen P. aeruginosa, and could represent a target for eradication of recalcitrant infections in situ.


Assuntos
Infecções por Pseudomonas , Pseudomonas aeruginosa , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Biofilmes , Ciprofloxacina/farmacologia , Interações Hospedeiro-Patógeno , Humanos , Camundongos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/genética , Virulência
6.
Int J Mol Sci ; 22(12)2021 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-34201173

RESUMO

Biofilms are the reason for a vast majority of chronic inflammation cases and most acute inflammation. The treatment of biofilms still is a complicated task due to the low efficiency of drug delivery and high resistivity of the involved bacteria to harmful factors. Here we describe a magnetically controlled nanocomposite with a stimuli-responsive release profile based on calcium carbonate and magnetite with an encapsulated antibiotic (ciprofloxacin) that can be used to solve this problem. The material magnetic properties allowed targeted delivery, accumulation, and penetration of the composite in the biofilm, as well as the rapid triggered release of the entrapped antibiotic. Under the influence of an RF magnetic field with a frequency of 210 kHz, the composite underwent a phase transition from vaterite into calcite and promoted the release of ciprofloxacin. The effectiveness of the composite was tested against formed biofilms of E. coli and S. aureus and showed a 71% reduction in E. coli biofilm biomass and an 85% reduction in S. aureus biofilms. The efficiency of the composite with entrapped ciprofloxacin was higher than for the free antibiotic in the same concentration, up to 72%. The developed composite is a promising material for the treatment of biofilm-associated inflammations.


Assuntos
Biofilmes/crescimento & desenvolvimento , Carbonatos/química , Ciprofloxacina/farmacologia , Escherichia coli/crescimento & desenvolvimento , Magnetismo , Nanocompostos/administração & dosagem , Staphylococcus aureus/crescimento & desenvolvimento , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Escherichia coli/efeitos dos fármacos , Nanocompostos/química , Staphylococcus aureus/efeitos dos fármacos
7.
Biomolecules ; 11(5)2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-34063146

RESUMO

Enterococcus faecium and Enterococcus faecalis are opportunistic pathogens that can cause a vast variety of nosocomial infections. Moreover, E. faecium belongs to the group of ESKAPE microbes, which are the main cause of hospital-acquired infections and are especially difficult to treat because of their resistance to many antibiotics. Antimicrobial photodynamic inactivation (aPDI) represents an alternative to overcome multidrug resistance problems. This process requires the simultaneous presence of oxygen, visible light, and photosensitizing compounds. In this work, aPDI was used to resensitize Enterococcus spp. isolates to antibiotics. Antibiotic susceptibility testing according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations was combined with synergy testing methods recommended by the American Society for Microbiology. Two clinical isolates, E. faecalis and E. faecium, were treated with a combination of aPDI utilizing rose bengal (RB) or fullerene (FL) derivative as photosensitizers, antimicrobial blue light (aBL), and 10 recommended antibiotics. aPDI appeared to significantly impact the survival rate of both isolates, while aBL had no significant effect. The synergy testing results differed between strains and utilized methods. Synergy was observed for RB aPDI in combination with gentamycin, ciprofloxacin and daptomycin against E. faecalis. For E. faecium, synergy was observed between RB aPDI and gentamycin or ciprofloxacin, while for RB aPDI with vancomycin or daptomycin, antagonism was observed. A combination of FL aPDI gives a synergistic effect against E. faecalis only with imipenem. Postantibiotic effect tests for E. faecium demonstrated that this isolate exposed to aPDI in combination with gentamycin, streptomycin, tigecycline, doxycycline, or daptomycin exhibits delayed growth in comparison to untreated bacteria. The results of synergy testing confirmed the effectiveness of aPDI in resensitization of the bacteria to antibiotics, which presents great potential in the treatment of infections caused by multidrug-resistant strains.


Assuntos
Antibacterianos/farmacologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecium/efeitos dos fármacos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Biofilmes/efeitos dos fármacos , Ciprofloxacina/farmacologia , Terapia Combinada , Daptomicina/farmacologia , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Enterococcus faecalis/crescimento & desenvolvimento , Enterococcus faecium/crescimento & desenvolvimento , Gentamicinas/farmacologia , Testes de Sensibilidade Microbiana , Plâncton/efeitos dos fármacos
8.
Appl Environ Microbiol ; 87(16): e0037321, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34085858

RESUMO

Spread of biosolids-borne antibiotic resistance is a growing public and environmental health concern. Herein, we conducted incubation experiments involving biosolids, which are byproducts of sewage treatment processes, and biosolids-amended soil. Quantitative reverse transcription-PCR (RT-qPCR) was employed to assess responses of select antibiotic resistance genes (ARGs) and mobile elements to environmentally relevant concentrations of two biosolids-borne antibiotics, azithromycin (AZ) and ciprofloxacin (CIP). Additionally, we examined sequence distribution of gyrA (encoding DNA gyrase; site of action of CIP) to assess potential shifts in genotype. Increasing antibiotic concentrations generally increased the transcriptional activities of qnrS (encoding CIP resistance) and ermB and mefE (encoding AZ resistance). The transcriptional activity of intl1, a marker of class 1 integrons, was unaffected by CIP or AZ concentrations, but biosolids amendment increased intl1 activity in the soil by 4 to 5 times, which persisted throughout incubation. While the dominant gyrA sequences found herein were unrelated to known CIP-resistant genotypes, the increasing CIP concentrations significantly decreased the diversity of genes encoding the DNA gyrase A subunit, suggesting changes in microbial community structures. This study suggests that biosolids harbor transcriptionally active ARGs and mobile elements that could survive and spread in biosolids-amended soils. However, more research is warranted to investigate these trends under field conditions. IMPORTANCE Although previous studies have indicated that biosolids may be important spreaders of antibiotics and antibiotic resistance genes (ARGs) in environments, the potential activities of ARGs or their responses to environmental parameters have been understudied. This study highlights that certain biosolids-borne antibiotics can induce transcriptional activities of ARGs and mobile genetic elements in biosolids and biosolids-amended soil, even when present at environmentally relevant concentrations. Furthermore, these antibiotics can alter the structure of microbial populations expressing ARGs. Our findings indicate the bioavailability of the antibiotics in biosolids and provide evidence that biosolids can promote the activities and dissemination of ARGs and mobile genes in biosolids and soils that receive contaminated biosolids, thus, underscoring the importance of investigating anthropogenically induced antibiotic resistance in the environment under real-world scenarios.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Bactérias/efeitos dos fármacos , Biossólidos/microbiologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sequências Repetitivas Dispersas/efeitos dos fármacos , Solo/química , Microbiologia do Solo , Poluentes do Solo/farmacologia
10.
BMJ Open ; 11(6): e042893, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172543

RESUMO

OBJECTIVE: To develop a tool predicting individualised treatment for gonorrhoea, enabling treatment with previously recommended antibiotics, to reduce use of last-line treatment ceftriaxone. DESIGN: A modelling study. SETTING: England and Wales. PARTICIPANTS: Individuals accessing sentinel health services. INTERVENTION: Developing an Excel model which uses participants' demographic, behavioural and clinical characteristics to predict susceptibility to legacy antibiotics. Model parameters were calculated using data for 2015-2017 from the Gonococcal Resistance to Antimicrobials Surveillance Programme. MAIN OUTCOME MEASURES: Estimated number of doses of ceftriaxone saved, and number of people delayed effective treatment, by model use in clinical practice. Model outputs are the predicted risk of resistance to ciprofloxacin, azithromycin, penicillin and cefixime, in groups of individuals with different combinations of characteristics (gender, sexual orientation, number of recent sexual partners, age, ethnicity), and a treatment recommendation. RESULTS: Between 2015 and 2017, 8013 isolates were collected: 64% from men who have sex with men, 18% from heterosexual men and 18% from women. Across participant subgroups, stratified by all predictors, resistance prevalence was high for ciprofloxacin (range: 11%-51%) and penicillin (range: 6%-33%). Resistance prevalence for azithromycin and cefixime ranged from 0% to 13% and for ceftriaxone it was 0%. Simulating model use, 88% of individuals could be given cefixime and 10% azithromycin, saving 97% of ceftriaxone doses, with 1% of individuals delayed effective treatment. CONCLUSIONS: Using demographic and behavioural characteristics, we could not reliably identify a participant subset in which ciprofloxacin or penicillin would be effective. Cefixime resistance was almost universally low; however, substituting ceftriaxone for near-uniform treatment with cefixime risks re-emergence of resistance to cefixime and ceftriaxone. Several subgroups had low azithromycin resistance, but widespread azithromycin monotherapy risks resistance at population level. However, this dataset had limitations; further exploration of individual characteristics to predict resistance to a wider range of legacy antibiotics may still be appropriate.


Assuntos
Gonorreia , Minorias Sexuais e de Gênero , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Ceftriaxona/uso terapêutico , Ciprofloxacina/farmacologia , Ciprofloxacina/uso terapêutico , Farmacorresistência Bacteriana , Inglaterra/epidemiologia , Feminino , Gonorreia/tratamento farmacológico , Gonorreia/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , País de Gales/epidemiologia
11.
Sci Rep ; 11(1): 9582, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953262

RESUMO

Stenotrophomonas maltophilia exhibits wide spectrum of fluoroquinolone resistance using different mechanisms as multidrug efflux pumps and Smqnr alleles. Here, the role of smeDEF, smeVWX efflux genes and contribution of Smqnr alleles in the development of fluoroquinolone resistance was assessed. Ciprofloxacin, levofloxacin and moxifloxacin resistance were found in 10.9%, 3.5%, and 1.6% of isolates, respectively. More than four-fold differences in ciprofloxacin MICs were detected in the presence of reserpine and smeD, F, V expression was significantly associated with ciprofloxacin resistance (p = 0.017 for smeD, 0.003 for smeF, and 0.001 for smeV). Smqnr gene was found in 52% of the ciprofloxacin-resistant isolates and Smqnr8 was the most common allele detected. Fluoroquinolone resistance in S. maltophilia clinical isolates was significantly associated with active efflux pumps. There was no correlation between the Smqnr alleles and ciprofloxacin resistance; however, contribution of the Smqnr genes in low-level levofloxacin resistance was revealed.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Fluoroquinolonas/farmacologia , Stenotrophomonas maltophilia/genética , Alelos , Ciprofloxacina/farmacologia , Irã (Geográfico) , Moxifloxacina/farmacologia , Stenotrophomonas maltophilia/efeitos dos fármacos , Stenotrophomonas maltophilia/isolamento & purificação
12.
J Antibiot (Tokyo) ; 74(8): 528-537, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34050325

RESUMO

Trans-translation is a unique bacterial ribosome rescue system that plays important roles in the tolerance to environmental stresses. It is composed of an ssrA-encoded tmRNA and a protein SmpB. In this study, we examined the role of trans-translation in antibiotic tolerance in Klebsiella pneumoniae and explored whether the inhibition of this mechanism could enhance the bactericidal activities of antibiotics. We found that deletion of the ssrA gene reduced the survival of K. pneumoniae after treatment with kanamycin, tobramycin, azithromycin, and ciprofloxacin, indicating an important role of the trans-translation in bacterial antibiotic tolerance. By using a modified ssrA gene with a 6×His tag we demonstrated that tobramycin suppressed the azithromycin and ciprofloxacin-elicited activation of trans-translation. The results were further confirmed with a trans-translation reporter system that is composed of a normal mCherry gene and a gfp gene without the stop codon. Compared to each individual antibiotic, combination of tobramycin with azithromycin or ciprofloxacin synergistically enhanced the killing activities against planktonic K. pneumoniae cells and improved bacterial clearance in a murine cutaneous abscess infection model. In addition, the combination of tobramycin and ciprofloxacin increased the bactericidal activities against biofilm-associated cells. Overall, our results suggest that the combination of tobramycin with azithromycin or ciprofloxacin is a promising strategy in combating K. pneumoniae infections.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Ciprofloxacina/farmacologia , Klebsiella pneumoniae/efeitos dos fármacos , Tobramicina/farmacologia , Animais , Biofilmes/efeitos dos fármacos , Códon , Cães , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Sinergismo Farmacológico , Humanos , Infecções por Klebsiella/tratamento farmacológico , Infecções por Klebsiella/microbiologia , Proteínas Luminescentes , Testes de Sensibilidade Microbiana
13.
Int Endod J ; 54(10): 1850-1860, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34033685

RESUMO

AIM: To evaluate the antimicrobial and immunomodulatory activity of double antibiotic paste (DAP) in an in vitro infection model. METHODOLOGY: The minimum inhibitory and bactericidal concentrations (MIC and MBC) and the antibiofilm activities (TTC assay) of DAP and its components (ciprofloxacin and metronidazole) were evaluated against Staphylococcus aureus and Enterococcus faecalis compared with triple antibiotic paste (TAP). The cellular viability of RAW 264.7 macrophages (24 and 72 h) and L929 fibroblasts (48 and 72 h) was evaluated by MTT. Furthermore, the production of TNF-α, IL-12, IL-6, IL-1α, IL-10 and NO (on RAW 264.7), besides IL-6, TGF-ß and NO (on L929), stimulated with DAP in baseline and associated with heat-killed microbial-antigen conditions was measured by ELISA and Griess reaction. Data were analysed using the one-way ANOVA test with Bonferroni's corrections. RESULTS: The MBC of pharmacopoeia DAP was similar to TAP for E. faecalis (0.25 µg.  mL-1 ) and lower for S. aureus (DAP 1 µg. mL-1 and TAP 2 µg. mL-1 ; p < .001). Ciprofloxacin was the most effective antibiofilm drug from the pastes (35% of reduction for E. faecalis and S. aureus; p < .0001), and both pastes had a similar antibiofilm eradication against both biofilm species (29% and 35% for S. aureus and 76% and 85% for E. faecalis; p < .0001). DAP was cytotoxic against the tested cells. DAP significantly upregulated IL-1α (p < .001), IL-6 (p < .0001), TNF-α (p < .01) and IL-12 (p < .05; in the absence of antigens) and significantly reduced IL-6 (p < .0001; in the presence of HK-S. aureus) and IL-10 (p < .05; in the presence of both antigens) on macrophages. Furthermore, DAP upregulated IL-6 (p < .001) and NO (p < .05; in the absence of antigens), IL-6 (p < .001; in the presence of HK-S. aureus) and reduced NO (p < .001; in the presence of HK-S. aureus). CONCLUSIONS: Double antibiotic paste and TAP had similar antimicrobial activity against S. aureus and E. faecalis. DAP upregulated pro-inflammatory cytokines mainly in the absence of antigens and had pro- and anti-inflammatory activity in RAW 264.7 macrophages and L929 fibroblasts in the presence of antigens involved in pulp infections.


Assuntos
Antibacterianos , Anti-Infecciosos , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Enterococcus faecalis , Staphylococcus aureus
14.
Anticancer Res ; 41(5): 2383-2395, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33952463

RESUMO

BACKGROUND/AIM: This study aimed to investigate the effect of the new ciprofloxacin chalcone [7-(4-(N-substituted carbamoyl methyl) piperazin-1 yl)] on the proliferation, migration, and metastasis of MCF-7 and MDA-MB-231 breast cancer cell lines. MATERIALS AND METHODS: Cell viability, colony formation and cell migration abilities were analysed. Cell cycle distribution and apoptosis were examined by flow cytometry. The molecular mechanism underlying chalcone's activity was investigated using qRT-PCR and western blotting. RESULTS: This new ciprofloxacin chalcone significantly inhibited proliferation, colony formation, and cell migration abilities of both cancer cell lines. Furthermore, it initiated apoptosis and caused cell cycle arrest at G2/M and S phase in MCF-7 and MDA-MB-231 cell lines, respectively. In addition, it up-regulated the expression of pro-apoptotic factors, p53, PUMA and NOXA, and down-regulated the expression of anti-apoptotic factors, MDM2 and MDM4. At the same time, it inhibited epithelial-mesenchymal transition by increasing the expression of E-cadherin and decreasing the expression of TGF-ß1, SNAI1, TWIST1, MMP2, and MMP9. CONCLUSION: This new ciprofloxacin chalcone exhibited promising apoptotic and anti-metastatic activities against MCF-7 and MDA-MB-231 breast cancer cell lines, and, therefore, is an attractive molecule for drug development in the treatment of breast cancer.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Chalcona/farmacologia , Ciprofloxacina/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Proteínas/metabolismo , Transdução de Sinais/efeitos dos fármacos , Apoptose/genética , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Caderinas/genética , Caderinas/metabolismo , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Movimento Celular/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Chalcona/química , Ciprofloxacina/química , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Estrutura Molecular , Proteínas/genética , Transdução de Sinais/genética , Fatores de Transcrição da Família Snail/genética , Fatores de Transcrição da Família Snail/metabolismo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Proteína 1 Relacionada a Twist/genética , Proteína 1 Relacionada a Twist/metabolismo
15.
Photodiagnosis Photodyn Ther ; 35: 102346, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34038764

RESUMO

BACKGROUND: Chordoma are uncommon aggressive tumors of the skeleton. Surgical resection is often subtotal and adjuvant treatment possibilities are limited as chordomas are highly chemo- and radioresistant. In the present study we examined the impact of 5-ALA PDT on different human chordoma cell lines. Furthermore, we investigated the variation of two parameters: (1.) 5-ALA incubation time and (2.) supplemental use of ciprofloxacin as iron chelator. METHODS: Experiments were realized in vitro with three different human chordoma cell lines: U-CH2, U-CH2B and U-CH14. After pre-incubation for 24 h with various concentrations of ciprofloxacin (1.5 - 5.0 µg/ml), different amounts of 5-ALA (15 - 50 µg/ml) were applied to the cells either for a brief (4 h) or a long (6 h) incubation time. Subsequently cells were exposed to photodynamic radiation. Cell viability was exploited by WST-1 assay. Thus, for each of the three cell lines, two drug combinations (ciprofloxacin plus 5-ALA and 5-ALA only) and two incubation times (short, 4 h and long, 6 h) were tested. Negative control groups were also examined. RESULTS: Supplemental use of ciprofloxacin led to increased cell death in each of the cell lines. Different 5-ALA incubation times (4 h vs. 6 h) showed no significant differences in cell viability except for U-CH2. CONCLUSION: Ciprofloxacin as an ordinary applied antibiotic, enhanced the effect of 5-ALA PDT on different human chordoma cell lines in vitro. The impact was dependent on the dose of ciprofloxacin-5-ALA. There were no notable differences for the tested 5-ALA incubation times. In human chordoma cell lines 5-ALA PDT may effectively be amended by ciprofloxacin.


Assuntos
Cordoma , Fotoquimioterapia , Ácido Aminolevulínico/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular , Cordoma/tratamento farmacológico , Ciprofloxacina/farmacologia , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia
16.
Ann Clin Microbiol Antimicrob ; 20(1): 36, 2021 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016127

RESUMO

BACKGROUND: Campylobacter resistance to antimicrobial agents is regarded as a major concern worldwide. The aim of this study was to investigate the expression of the CmeABC efflux pump and the RAPD-PCR pattern in drug-resistant Campylobacter isolates. METHODS: A total of 283 stool specimens were collected from children under the age of five with diarrhea. The minimum inhibitory concentration (MIC) of tetracycline and ciprofloxacin was determined by broth microdilution method and E-test, respectively. Detection of tetracycline and ciprofloxacin determinants was done by amplification of tetO gene and PCR-sequencing of the gyrA gene. The cmeABC transcriptional expression was analyzed by Real-time (RT)-PCR. Clonal correlation of resistant strains was determined by RAPD-PCR genotyping. RESULTS: Out of 283 fecal samples, 20 (7.02%) samples were positive for Campylobacter spp. Analysis of duplex PCR assay of the cadF gene showed that 737 and 461 bp amplicons were corresponding to Campylobacter jejuni and Campylobacter coli, respectively. All of the 17 phenotypically tetracycline-resistant Campylobacter isolates harbored the tetO gene. Also, four phenotypically ciprofloxacin-resistant Campylobacter isolates had a point mutation at codon 257 of the gyrA gene (ACA to ATA; Thr > Ile). High-level expression of the cmeA gene was observed in ciprofloxacin-resistant and high-level tetracycline-resistant Campylobacter isolates, suggesting a positive correlation between the cmeA gene expression level and tetracycline resistance level. Moreover, a statistically significant difference was observed in the cmeA gene expression between ciprofloxacin-resistant and ciprofloxacin-susceptible strains, which signifies the crucial contribution of the efflux pump in conferring multiple drug resistance phenotype among Campylobacter spp. RAPD analysis of Campylobacter isolates exhibited 16 different patterns. Simpsone`s diversity index of RAPD-PCR was calculated as 0.85, showing a high level of homogeneity among the population; however, no clear correlation was detected among tetracycline and/or ciprofloxacin resistant isolates. CONCLUSION: Significant contribution of the CmeABC efflux pump in conferring high-level resistance to tetracycline and ciprofloxacin was observed in C. jejuni and C. coli clinical isolates. The resistant phenotype is suggested to be mediated by CmeABC efflux pumps, the tetO gene, and point mutation of the gyrA gene. Genotyping revealed no clonal correlation among resistant strains, indicating distinct evolution of tetracycline and ciprofloxacin resistant genotypes among the isolates.


Assuntos
Antibacterianos/farmacologia , Campylobacter coli/efeitos dos fármacos , Campylobacter coli/fisiologia , Campylobacter jejuni/efeitos dos fármacos , Campylobacter jejuni/fisiologia , Farmacorresistência Bacteriana , Proteínas de Membrana Transportadoras/fisiologia , Proteínas de Bactérias/fisiologia , Ciprofloxacina/farmacologia , DNA Bacteriano , Diarreia/microbiologia , Fezes/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Técnica de Amplificação ao Acaso de DNA Polimórfico , Tetraciclina/farmacologia
17.
J Med Microbiol ; 70(5)2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33999797

RESUMO

Introduction. Mycobacterium avium complex (MAC) has been reported as the most common aetiology of lung disease involving nontuberculous mycobacteria.Hypothesis. Antimicrobial susceptibility and clinical characteristics may differ between Mycobacterium avium and Mycobacterium intracellulare.Aim. We aimed to evaluate the differences in antimicrobial susceptibility profiles between two major MAC species (Mycobacterium avium and Mycobacterium intracellulare) from patients with pulmonary infections and to provide epidemiologic data with minimum inhibitory concentration (MIC) distributions.Methodology. Between January 2019 and May 2020, 45 M. avium and 242 M. intracellulare isolates were obtained from Shanghai Pulmonary Hospital. The demographic and clinical characteristics of patients were obtained from their medical records. The MICs of 13 antimicrobials were determined for the MAC isolates using commercial Sensititre SLOWMYCO MIC plates and the broth microdilution method, as recommended by the Clinical and Laboratory Standards Institute (CLSI; Standards M24-A2). MIC50 and MIC90 values were derived from the MIC distributions.Results. M. intracellulare had higher resistance rates than M. avium for most tested antimicrobials except clarithromycin, ethambutol, and ciprofloxacin. Clarithromycin was the most effective antimicrobial against both the M. avium (88.89 %) and M. intracellulare (91.32 %) isolates, with no significant difference between the species (P=0.601). The MIC90 of clarithromycin was higher for M. avium (32 µg ml-1) than M. intracellulare (8 µg ml-1). The MIC50 of rifabutin was more than four times higher for M. intracellulare (1 µg ml-1) than M. avium (≤0.25 µg ml-1). The percentages of patients aged >60 years and patients with sputum, cough, and cavitary lesions were significantly higher than among patients with M. intracellulare infection than M. avium infections.Conclusions. The pulmonary disease caused by distinct MAC species had different antimicrobial susceptibility, symptoms, and radiographic findings.


Assuntos
Antibacterianos/farmacologia , Pneumopatias/microbiologia , Complexo Mycobacterium avium/efeitos dos fármacos , Infecção por Mycobacterium avium-intracellulare/microbiologia , Mycobacterium avium/efeitos dos fármacos , Adulto , Idoso , China , Ciprofloxacina/farmacologia , Claritromicina/farmacologia , Tosse , Doxiciclina/farmacologia , Farmacorresistência Bacteriana , Feminino , Humanos , Pulmão/diagnóstico por imagem , Pneumopatias/fisiopatologia , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mycobacterium avium/isolamento & purificação , Complexo Mycobacterium avium/isolamento & purificação , Infecção por Mycobacterium avium-intracellulare/diagnóstico , Infecção por Mycobacterium avium-intracellulare/fisiopatologia , Radiografia , Escarro
18.
Microb Pathog ; 157: 104973, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34029657

RESUMO

This study was designed to investigate the cooperative resistance in the mixed culture of antibiotic-sensitive and antibiotic-resistant Salmonella Typhimurium. Strains of S. Typhimurium ATCC 19585 (STS) and clinically isolated antibiotic-resistant S. Typhimurium CCARM 8009 (STR) grown in single and mixture with 1 × MIC ceftriaxone (CEF) were used to determine the viability, ß-lactamase activity, and gene expression. The MIC50 values of STR to CEF was increased by more than 5-fold with increasing inoculum densities from 102 to 107 CFU/mL. STS was resistant to 1 × MIC CEF in the mixed culture of STS and STR, showing the more than 108 CFU/mL after 20 h of incubation at 37 °C. The highest ß-lactamase activity was 18 µmol/min/mL in the mixed culture, corresponding to the highest relative expression of ß-lactamase-related genes (blaTEM). These results shed new light on the cooperative resistance of antibiotic-sensitive bacteria within a heterogeneous population including ß-lactamase-producing bacteria.


Assuntos
Ciprofloxacina , Salmonella typhimurium , Antibacterianos/farmacologia , Ciprofloxacina/farmacologia , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Salmonella typhimurium/genética , beta-Lactamases/genética
19.
Environ Res ; 199: 111321, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33989619

RESUMO

A global upsurge in emergence and spread of antibiotic resistance (ABR) in bacterial populations is a serious threat for human health. Unfortunately, ABR is no longer confined to nosocomial environments and is frequently reported from community microbes as well. The ABR is resulting in shrinking potent antibiotics pool and thus necessitating novel and alternative therapies and therapeutics. Current investigation was aimed to assess the synergistic potential of a synthesized, phytomolecule-loaded, polysaccharide-stabilized metallic nanoparticles (NPs) against Pseudomonas aeruginosa (PA) and Escherichia coli (EC) isolated from river waters. ABR profiling of these strains characterized them as multidrug resistant (MDR). Synthesized embelin (Emb, isolated from Embelia tsjeriam-cottam)-loaded, chitosan-gold (Emb-Chi-Au) NPs were assessed for their potential synergistic activity with ciprofloxacin (CIP) via checker-board assay and time-kill curve analysis. The NPs reduced the minimal inhibitory concentration (MIC) of CIP by 16- and 4-fold against MDR PA (PA-r) and EC (EC-r) strains, respectively. Fractional inhibitory concentration (FIC) indices with ≤0.5 values confirmed the synergy between the Emb-Chi-Au NPs and CIP, which was further confirmed at ½ MICs in both PA-r and EC-r via time-kill curve analysis. In order to decipher the mode of action, efflux pump inhibitory effects of Emb-Chi-Au NPs were evaluated in terms of the increase in the EtBr mediated fluorescence in control versus NP-treated MDR strains. Molecular docking based in silico simulations were used to predict the interactions between Emb and the active sites of the efflux pump related proteins in PA-r (MexA, MexB and OprM) and EC-r (AcrA, AcrB and TolC), which revealed the probable bond formation between Emb and respective amino acid residues.


Assuntos
Quitosana , Proteínas de Escherichia coli , Nanopartículas Metálicas , Antibacterianos/farmacologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Benzoquinonas , Ciprofloxacina/farmacologia , Escherichia coli , Ouro , Humanos , Proteínas de Membrana Transportadoras , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Pseudomonas aeruginosa
20.
Ann Clin Lab Sci ; 51(2): 255-257, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33941566

RESUMO

Bacterial peritonitis is a key complication of Peritoneal Dialysis (PD) and a preventable cause of withdrawal from PD treatment. Infection generally arises from contamination with skin commensals during handling of the dialysis delivery system or from translocation of gastrointestinal organisms and more rarely from an environmental organism. Herein, we report the case of a 73-year-old admitted for PD-related peritonitis due to Roseomonas gilardii with an associated environmental exposure from a domestic plumbing issue. We describe the presentation, case, and antibiotic regimen progression from empiric therapy of ceftazidime and vancomycin IP to ciprofloxacin. We acknowledge the importance of performing laboratory sensitivities given the high antibiotic resistance of the Roseomonas genus. We offer that nephrologists should consider Roseomonas as a potential causative organism of peritonitis, especially when initial or further history reveals exposure to potentially contaminated water.


Assuntos
Methylobacteriaceae/patogenicidade , Peritonite/diagnóstico , Peritonite/microbiologia , Idoso , Ciprofloxacina/farmacologia , Humanos , Masculino , Methylobacteriaceae/genética , Diálise Peritoneal/efeitos adversos , Peritonite/genética , Diálise Renal/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...