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1.
Mikrobiyol Bul ; 54(1): 154-162, 2020 Jan.
Artigo em Turco | MEDLINE | ID: mdl-32050886

RESUMO

Acinetobacter species lead to nosocomial infections in immunocompromised patients hospitalized in intensive care units or services. Acinetobacter baumannii is a bacterium that is difficult to treat because it is intrinsically resistant to many antibiotics and can develop resistance afterwards. This situation limits the use of existing antibiotics and directs the clinician to new agents, different treatment options and the use of various antibiotic combinations. The aim of this study was to determine the sensitivities of doripenem (DOR), tigecycline (TGC), minocycline (MIN), amikacin (AK) and a newly developed agent ceftolozane-tazobactam (CT) in multidrug resistant A.baumannii strains which were isolated from inpatients in intensive care units and to investigate the in vitro interactions of CT/DOR, CT/TGC, CT/MIN and CT/AK combinations by using antibiotic gradient test method. Thirty-five A.baumannii strains isolated from various clinical specimens (blood, urine, sputum, tracheal aspirate, wound, abscess and catheter) between January 2017 and July 2017 were included in the study. Strains isolated from inpatients in intensive care units and resistant to at least three antibiotic classes were selected. The identification of A.baumannii isolates and the determination of routine antibiotic susceptibility profile were performed according to EUCAST 2017 criteria by the use of BD Phoenix 100 (Becton Dickinson, USA) automated system. Minimum inhibitor concentration values of CT, DOR, TGC, MIN, AK and combinations of CT with four other antibiotics (CT/DOR, CT/TGC, CT/MIN and CT/AK) were determined by antibiotic gradient test method. Fractional inhibitor concentration index (FICI) was used to determine the interactions of the combinations in vitro. According to the data obtained; the FICI was evaluated as synergy if FICI ≤ 0.5, additive if 0.5 > FICI ≤ 1, indifferent (unidentified interaction) if 1

Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Cefalosporinas , Tazobactam , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/efeitos dos fármacos , Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Técnicas In Vitro , Testes de Sensibilidade Microbiana , Tazobactam/farmacologia
2.
PLoS One ; 15(1): e0220427, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32004341

RESUMO

Identifying and controlling the emergence of antimicrobial resistance (AMR) is a high priority for researchers and public health officials. One critical component of this control effort is timely detection of emerging or increasing resistance using surveillance programs. Currently, detection of temporal changes in AMR relies mainly on analysis of the proportion of resistant isolates based on the dichotomization of minimum inhibitory concentration (MIC) values. In our work, we developed a hierarchical Bayesian latent class mixture model that incorporates a linear trend for the mean log2MIC of the non-resistant population. By introducing latent variables, our model addressed the challenges associated with the AMR MIC values, compensating for the censored nature of the MIC observations as well as the mixed components indicated by the censored MIC distributions. Inclusion of linear regression with time as a covariate in the hierarchical structure allowed modelling of the linear creep of the mean log2MIC in the non-resistant population. The hierarchical Bayesian model was accurate and robust as assessed in simulation studies. The proposed approach was illustrated using Salmonella enterica I,4,[5],12:i:- treated with chloramphenicol and ceftiofur in human and veterinary samples, revealing some significant linearly increasing patterns from the applications. Implementation of our approach to the analysis of an AMR MIC dataset would provide surveillance programs with a more complete picture of the changes in AMR over years by exploring the patterns of the mean resistance level in the non-resistant population. Our model could therefore serve as a timely indicator of a need for antibiotic intervention before an outbreak of resistance, highlighting the relevance of this work for public health. Currently, however, due to extreme right censoring on the MIC data, this approach has limited utility for tracking changes in the resistant population.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Cloranfenicol/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Animais , Teorema de Bayes , Conjuntos de Dados como Assunto , Humanos , Modelos Lineares , Testes de Sensibilidade Microbiana , Saúde Pública , Infecções por Salmonella/microbiologia , Salmonella enterica/crescimento & desenvolvimento , Salmonella enterica/isolamento & purificação , Suínos , Doenças dos Suínos/microbiologia
3.
Int J Antimicrob Agents ; 55(3): 105891, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923569

RESUMO

Ceftolozane/tazobactam (C/T) is a novel ß-lactam/ß-lactamase inhibitor combination targeting Enterobacteriaceae and Pseudomonas aeruginosa (PA). It is approved in adult patients for complicated urinary tract infections (cUTIs) and complicated intra-abdominal infections (cIAIs) as well as for nosocomial pneumonia. It displays excellent activity against PA, even multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains. The aim of this systematic review (PROSPERO protocol no. CRD42019117350) was to summarise the available evidence from observational studies regarding the efficacy and safety of off-label use of C/T when administered to treat MDR- or XDR-PA infections. The MEDLINE and Embase databases were screened from inception up to 30 June 2019. Studies were deemed eligible if they described real-life use of C/T in the case of MDR- or XDR-PA infections for non-approved indications. Exclusion criteria were cIAIs, cUTIs, pneumonia (unless occurring in a paediatric population) and infections by non-MDR/XDR-PA. Thirty articles fulfilled the inclusion criteria. In total, 130 cases of MDR- or XDR-PA infections treated with C/T in 128 patients were described. The most relevant off-label uses were skin and soft-tissue infection (49/30; 37.7%), bone and joint infection (42/130; 32.3%) and bloodstream infection (23/130; 17.7%). Five cases involved paediatric patients. The overall clinical success rate was 76.2%. The most common adverse event was hypokalaemia (4.2%, in 48 evaluable cases). C/T may be a useful therapeutic option for difficult-to-treat infections by PA even outside the framework of approved indications. Further studies are necessary to better define new indications for the drug.


Assuntos
Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Infecções por Enterobacteriaceae/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Tazobactam/uso terapêutico , Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Infecções Intra-Abdominais/tratamento farmacológico , Estudos Observacionais como Assunto , Infecções dos Tecidos Moles/tratamento farmacológico , Tazobactam/farmacologia , Infecções Urinárias/tratamento farmacológico
4.
Int J Antimicrob Agents ; 55(3): 105889, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923573

RESUMO

Colistin is the last-resort antimicrobial agent against infections caused by multidrug-resistance Gram-negative bacteria (MDR-GNB). However, a differing risk of colistin-associated acute kidney injury (CA-AKI) has been demonstrated without affecting mortality, thus the association and its importance needs to be questioned. To assess the impact of this adverse effect, a meta-analysis comparing colistin with other antibiotics in treating MDR-GNB infections was conducted. The PubMed, Embase and Cochrane Library electronic databases were searched up to 31 December 2018 for cohort studies and randomised controlled trials with at least two arms with one arm containing colistin-based treatment. The primary endpoint was the incidence of AKI. The secondary endpoint was 30-day all-cause mortality. A total of 34 studies, including 26 regarding colistin-based therapy versus other antibiotics and 9 regarding colistin monotherapy versus combination therapy, were included. The incidence of CA-AKI was 32.3%. Colistin was associated with an 82% higher incidence of AKI than other antibiotics [odd ratio (OR) = 1.82, 95% confidence interval (CI) 1.13-2.92; P = 0.01]. Most CA-AKI events were mild and reversible without a higher rate of mortality or the requirement for renal replacement therapy (RRT). Only 1.0% of patients required RRT for > 4 weeks. Compared with colistin monotherapy, combination therapy was associated with a significantly lower incidence of AKI (OR = 1.46, 95% CI 1.10-1.94; P = 0.009), particularly in combination with a carbapenem (OR = 1.97, 95% CI 1.30-2.99; P = 0.001). In conclusion, CA-AKI might not be an important limitation of colistin in MDR-GNB therapy.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Antibacterianos/administração & dosagem , Colistina/efeitos adversos , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Lesão Renal Aguda/mortalidade , Lesão Renal Aguda/terapia , Adulto , Antibacterianos/uso terapêutico , Carbapenêmicos/farmacologia , Carbapenêmicos/uso terapêutico , Estudos de Coortes , Colistina/uso terapêutico , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Incidência , Terapia de Substituição Renal
5.
Int J Antimicrob Agents ; 55(3): 105887, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31926283

RESUMO

The STEP surveillance study was designed to increase knowledge about distribution of multidrug-resistant (MDR) Enterobacterales and Pseudomonas aeruginosa in Portugal, focusing on the intensive care unit (ICU). Antimicrobial susceptibility of common agents was also evaluated and compared with that of one of the latest therapeutic introductions, ceftolozane-tazobactam (C/T). Clinical isolates of Enterobacterales (n=426) and P. aeruginosa (n=396) from patients admitted in Portuguese ICUs were included. Activity of C/T and comparators was investigated using standard broth microdilution. Isolates were recovered from urinary tract (UTI, 36.9%), intra-abdominal (IAI, 24.2%) and lower respiratory tract (LRTI, 38.9%) infections. In P. aeruginosa, overall distribution of MDR/extremely-drug resistant (XDR)/pan-drug resistant (PDR) isolates accounted for 21.2%, 23.2% and 0.8%, respectively. C/T was the most potent agent tested against P. aeruginosa and MDR/XDR/PDR phenotypes. In Escherichia coli, extended-spectrum beta-lactamases (ESBL) and carbapenemase (CP) phenotypes accounted for 16.6% and 1.7%, respectively, whereas in Klebsiella spp., ESBL and CP-phenotypes represented 28.5% and 17.9%, respectively. Overall, susceptibility of C/T against Enterobacterales was 86.9%. C/T was the least affected agent in E. coli (99.4% susceptibility), whereas its activity was moderate in Klebsiella spp. (71.5%) and Enterobacter spp. (70.4%), due in part to a high rate of ESBL and CP-phenotypes. In Enterobacterales, blaKPC was the most prevalent CP gene (63.0%), followed by blaOXA-48 (33.3%) and blaVIM (3.7%). These microbiological results reinforce C/T as a therapeutic option in ICU patients with UTI, IAI or LRTI due to P. aeruginosa or Enterobacterales isolates, but not for CP producers.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Infecções por Enterobacteriaceae/tratamento farmacológico , Enterobacteriaceae/efeitos dos fármacos , Infecções Intra-Abdominais/tratamento farmacológico , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções Respiratórias/tratamento farmacológico , Tazobactam/farmacologia , Infecções Urinárias/tratamento farmacológico , Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções por Enterobacteriaceae/microbiologia , Humanos , Unidades de Terapia Intensiva , Portugal , Infecções por Pseudomonas/microbiologia , Tazobactam/uso terapêutico
6.
J Basic Microbiol ; 60(3): 216-230, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31994223

RESUMO

The aim of the present work was to investigate the antibacterial, antibiofilm, and antiquorum sensing activities of phytosynthesized silver nanoparticles (AgNPs) fabricated from Mespilus germanica extract against multidrug-resistant (MDR) Klebsiella pneumoniae strains. Fifty strains of K. pneumoniae were isolated from various clinical specimens. Biofilm-forming strains were identified using Congo red agar and polymerase chain reaction (PCR) techniques. Subsequently, the antibacterial activity of phytosynthesized AgNPs on MDR K. pneumoniae strains was investigated by broth microdilution assay and agar well-diffusion method. Finally (in the last step), the antibiofilm activity of phytosynthesized AgNPs was determined using microtiter plate assay and real-time PCR (RT-PCR) methods for the analysis of type 3 fimbriae (mrkA) and quorum-sensing system (luxS) gene expression. The results of this study showed that the phytosynthesized AgNPs had a spherical nanostructure with the mean size of 17.60 nm. The AgNPs exhibited dose-dependent antibacterial activity. The results of the microtiter plate and RT-PCR methods show that AgNPs inhibited the biofilm formation in MDR K. pneumoniae strains, and the expressions of mrkA and luxS genes were downregulated significantly in MDR strains after treatment with a subminimum inhibitory concentration of AgNPs. In conclusion, AgNPs effectively prevent the formation of biofilms and kill bacteria in established biofilms, which suggests that AgNPs might be a promising candidate for the prevention and treatment of biofilm-related infections caused by MDR K. pneumoniae strains.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Nanopartículas Metálicas/química , Rosaceae/química , Prata/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Proteínas de Bactérias/genética , Biofilmes/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Química Verde , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/fisiologia , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Percepção de Quorum/genética , Prata/química
7.
Chem Commun (Camb) ; 56(14): 2147-2150, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31970367

RESUMO

Cyclam-based antibacterial molecules (CAMs) that display potent activity against both the planktonic and stationary phase of multidrug-resistant Gram-negative bacteria were rationally designed. The optimized compound retained its activity in human plasma and eradicated preformed biofilms. It also revealed excellent potency in an ex vivo model of human corneal infections with negligible propensity of resistance development. This indicated the potential of this class of compound as a future antibacterial agent to tackle human corneal infections.


Assuntos
Antibacterianos/farmacologia , Doenças da Córnea/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Compostos Heterocíclicos/farmacologia , Antibacterianos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Compostos Heterocíclicos/química , Humanos , Testes de Sensibilidade Microbiana
8.
Chem Biodivers ; 17(1): e1900496, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31909551

RESUMO

The genus Lavandula is known for its different uses in traditional medicine. This study is interested in the chemical composition of Lavandulapedunculata subsp.atlantica (Braun-Blanq.) Romo as well as evaluating its antibacterial potential against multi-resistant strains. The analysis of Lavandulaatlantica essential oil (LAEO) allows the identification of 47 components representing 93.6 % of all identified. The main constituent of LAEO was camphor (50.4 %), followed by fenchone (14.1 %) and camphene (5.6 %). The antibacterial assays revealed that LAEO was active against all the studied bacteria. A preliminary study of the relationship between certain terpenoids and antibacterial activity was also carried out in order to note the compound(s) that are responsible for LAEO's antibacterial activity. This study showed that the activity of the essential oil may be due to the presence of certain minor compounds such as carvone, considering the presence of the synergistic effect between the essential oil.


Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Lavandula/química , Óleos Voláteis/farmacologia , Terpenos/farmacologia , Antibacterianos/análise , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Óleos Voláteis/análise , Relação Estrutura-Atividade , Terpenos/análise
9.
J Immunoassay Immunochem ; 41(1): 97-105, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31777299

RESUMO

Management of ventilator-associated pneumonia (VAP) is a puzzling issue for infectious disease specialist. The present clinical trial study was aimed to comparing the effects of injectable colistin plus nebulized colistin and injectable colistin plus nebulized tobramycin on management of patients with VAP due to multidrug-resistant Acinetobacter. VAP patients were randomly divided into two groups (n = 30/each): Group 1 - patients that received intravenous (IV) meropenem, injectable colistin plus nebulized colistin, as a routine treatment, and Group 2 - patients that received IV meropenem, injectable colistin plus nebulized tobramycin. A total of 14 days of therapeutic intervention are required for every case. Follow-up for subjects was performed at five time-points: days 1, 3, 5, 7, and 14 after intervention. Also, a mean of creatinine levels of patients was determined in five times. In the present study, the clinical pulmonary infection score (CPIS) was determined on the basis of points assigned for various clinically manifestations of VAP. Based on our statistical analysis, there was no significant difference between CPIS and creatinine level in both Groups 1 and 2 (p > .05). CPIS and other clinical investigation appeared effectiveness of the treatment with injected colistin plus nebulized tobramycin; on the other hand, the results of present clinical trial showed that aforementioned therapeutic approach can be used as an alternative treatment for the management of infection in VAP patients.


Assuntos
Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Pneumonia Associada à Ventilação Mecânica/microbiologia , Tobramicina/farmacologia , Antibacterianos/administração & dosagem , Antibacterianos/química , Colistina/administração & dosagem , Colistina/química , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Tobramicina/administração & dosagem , Tobramicina/química
10.
J Appl Microbiol ; 128(1): 15-27, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31102552

RESUMO

Acinetobacter baumannii causes several nosocomial infections and poses major threat when it is multidrug resistant. Even pan drug-resistant strains have been reported in some countries. The intensive care unit (ICU) mortality rate ranged from 45.6% to 60.9% and it is as high as 84.3% when ventilator-associated pneumonia was caused by XDR (extensively drug resistant) A. baumannii. Acinetobacter baumannii constituted 9.4% of all Gram-negative organisms throughout the hospital and 22.6% in the ICUs according to a study carried out in an Indian hospital. One of the major factors contributing to drug resistance in A. baumannii infections is biofilm development. Quorum sensing (QS) facilitates biofilm formation and therefore the search for 'quorum quenchers' has increased recently. Such compounds are expected to inhibit biofilm formation and hence reduce/prevent development of drug resistance in the bacteria. Some of these compounds also target synthesis of some virulence factors (VF). Several candidate drugs have been identified and are at various stages of drug development. Since quorum quenching, inhibition of biofilm formation and inhibition of VF synthesis do not pose any threat to the DNA replication and cell division of the bacteria, chances of resistance development to such compounds is presumably rare. Thus, these compounds ideally qualify as adjunct therapeutics and could be administered along with an antibiotic to reduce chances of resistance development and also to increase the effectiveness of antimicrobial therapy. This review describes the state-of-art in QS process in Gram-negative bacteria in general and in A. baumannii in particular. This article elaborates the nature of QS mediators, their characteristics, and the methods for their detection and quantification. Various potential sites in the QS pathway have been highlighted as drug targets and the candidate quorum quenchers which inhibit the mediator's synthesis or function are enlisted.


Assuntos
Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/fisiologia , Percepção de Quorum , Infecções por Acinetobacter/tratamento farmacológico , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/patogenicidade , Acil-Butirolactonas/metabolismo , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Desenvolvimento de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/genética , Percepção de Quorum/efeitos dos fármacos , Fatores de Virulência/metabolismo
11.
Khirurgiia (Mosk) ; (12): 74-83, 2019.
Artigo em Russo | MEDLINE | ID: mdl-31825346

RESUMO

AIM: To determine the place of new drugs with activity against multidrug resistant strains of microorganisms in the treatment of complicated intraabdominal infections. MATERIAL AND METHODS: The incidence and distribution of pathogens isolated from intra-abdominal specimens in patients with intra-abdominal infections are analyzed. RESULTS: The current situation on the growth of resistant strains among pathogens causing intra-abdominal infections is rewied. New combined drugs for the treatment of multidrug resistant infections - ceftolozane/tazobactam and ceftazidim/avibactam plus metronidazole, has been suggested. Their potential role in empiric and targeted antibacterial treatment of complicated intraabdominal infections is defined. CONCLUSION: Taking into consideration local monitoring data and risk factors of multi resistant strains Ceftolozane/tazobactam in combination with metronidazole can be used in empiric regime of treatment. Due to the high activity on carbapenem resistant strains of Klebsiella pneumonia and the lack of alternatives, it is advisable to use Ceftazidim/avibactam for the targeted therapy.


Assuntos
Antibacterianos/administração & dosagem , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções Intra-Abdominais/tratamento farmacológico , Infecções Intra-Abdominais/microbiologia , Compostos Azabicíclicos/administração & dosagem , Ceftazidima/administração & dosagem , Cefalosporinas/administração & dosagem , Combinação de Medicamentos , Humanos , Ácido Penicilânico/administração & dosagem
12.
BMC Infect Dis ; 19(1): 1049, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31829153

RESUMO

BACKGROUND: Diphtheria has been reported as an outbreak in some regions in Indonesia, most especially in East Java Province. Resistance to penicillin, erythromycin, and other antibiotics, single or multiple, has been reported in several studies. This study aims to evaluate the first-line antibiotic susceptibility pattern of toxigenic Corynebacterium diphtheriae isolates. METHODS: This descriptive observational study was performed from August to November 2018. C. diphtheriae isolates were collected from diphtheria patients and carriers in East Java from 2012 to 2017 and kept at the Balai Besar Laboratorium Kesehatan Daerah Surabaya or the Public Health Laboratory of Surabaya. Sample selection was done by random cluster sampling. The sensitivity test by E-test®of the five antibiotics (penicillin, oxacillin, erythromycin, azithromycin, and clarithromycin) was done to determine the minimum inhibitory concentration (MIC). The Clinical and Laboratory Standards Institute M45A (2015) Corynebacterium spp. for penicillin and erythromycin was used as standard. RESULTS: From 114 targeted isolates, 108 were viable and toxigenic. The E-test was performed on the viable isolates. The majority of the hosts were male (58.3%), with median (range) age of 6.5 (1-14) years. Half of the samples were from the 1 to 5-year-old age group. The isolates were acquired much more from patients (78.7%) than carriers (21.3%) and from pharyngeal swab (74.1%). Most of these isolates were from Madura Island (47.2%) and the northern and eastern parts of the province (horseshoe area). Mitis isolates were the major variant (76.9%). The susceptibility pattern of C. diphtheriae to erythromycin was better than that to penicillin. The E-test result for penicillin was 68.52% susceptible, 31.48% intermediate, and 0% resistant (MIC range, < 0.016 to 2 µg/L) and for erythromycin (MIC range, < 0.016 to > 256 µg/L) was 85.2% susceptible, 12% intermediate, and 2.8% resistant The MIC range for oxacillin was 1 to 96 µg/L, while for both azithromycin and clarithromycin were <  0.016 to > 256 µg/L. CONCLUSION: The susceptibility rate of C. diphtheriae to erythromycin is higher than that to penicillin. The regular update of antibiotic selection to the national guidelines is recommended. The MIC reference standard to azithromycin and clarithromycin is also needed.


Assuntos
Antibacterianos/uso terapêutico , Corynebacterium diphtheriae/efeitos dos fármacos , Difteria/tratamento farmacológico , Difteria/epidemiologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Eritromicina/uso terapêutico , Penicilinas/uso terapêutico , Adolescente , Criança , Pré-Escolar , Corynebacterium diphtheriae/isolamento & purificação , Feminino , Humanos , Indonésia/epidemiologia , Lactente , Masculino , Testes de Sensibilidade Microbiana
13.
Int J Nanomedicine ; 14: 9031-9046, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31819417

RESUMO

Background: The global increase in outbreaks and mortality rates associated with multi-drug-resistant (MDR) bacteria is a major health concern and calls for alternative treatments. Natural-derived products have shown potential in combating the most dreadful diseases, and therefore serve as an effective source of bioactive compounds that can be used as anti-bacterial agents. These compounds are able to reduce metal ions and cap nanoparticles to form biogenic nanoparticles (NPs) with remarkable anti-bacterial activities. This study explores the use of Terminalia mantaly (TM) extracts for the synthesis of biogenic silver NPs (TM-AgNPs) and the evaluation of their antibacterial activity. Methods: TM-AgNPs were synthetized by the reduction of AgNO3 with aqueous and methanolic TM extracts. UV-visible (UV-vis) spectrophotometry, Dynamic Light Scattering (DLS), Transmission Electron Microscopy, and Fourier Transform Infrared (FTIR) analyses were used to characterise the TM-AgNPs. Anti-bacterial activity of the TM extracts and TM-AgNPs was evaluated against eight bacterial strains using the broth microdilution assay. The growth inhibitory kinetics of the bio-active TM-AgNPs was assessed on susceptible strains for a period of 8 hrs. Results: Polycrystalline biogenic AgNPs with anisotropic shapes and diameter range of 11 to 83 nm were synthesized from the TM extracts. The biogenic TM-AgNPs showed significant antibacterial activity compared to their respective extracts. The MIC values for TM-AgNPs and extracts were 3 and 125 µg/mL, respectively. Biogenic AgNPs synthesised from the aqueous TM leaf extract at 25°C (aTML-AgNPs-25°C) showed significant antibacterial activity against all the bacterial strains tested in this study. Their bactericidal effect was particularly higher against the Streptococcus pneumoniae and Haemophilus influenzae. Conclusion: This study demonstrated the ability of TM extracts to synthesize biogenic AgNPs. The NPs synthesized from the aqueous TM extracts demonstrated higher antibacterial activity against the tested microorganisms compared to the methanolic extracts. Studies are underway to identify the phytochemicals involved in NP synthesis and their mechanism of action.


Assuntos
Antibacterianos/farmacologia , Nanopartículas Metálicas/química , Extratos Vegetais/química , Prata/farmacologia , Terminalia/química , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Difusão Dinâmica da Luz , Nanopartículas Metálicas/ultraestrutura , Testes de Sensibilidade Microbiana , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier
14.
Rev Chilena Infectol ; 36(5): 551-555, 2019 Oct.
Artigo em Espanhol | MEDLINE | ID: mdl-31859795

RESUMO

BACKGROUND: Pseudomonas aeruginosa is an opportunistic pathogen associated with high morbidity and mortality. For multidrug-resistant strains (MDR), ceftolozane/tazobactam (CTZ) has been authorized by the European Medicines Agency (EMA) for complicated urinary tract infections, acute pyelonephritis, and complicated intraabdominal infections. AIM: To determine the susceptibility to CTZ of P. aeruginosa MDR in isolated clinical samples at the University Hospital Puerto Real. METHODS: The susceptibility according to the EUCAST to CTZ criteria of strains of P. aeruginosa MDR, between January 2015 and August 2017 has been studied. The multiresistance criteria were those defined by the Centers for Disease Control and Prevention. The antibiotic susceptibility was obtained by automated MicroScan® system (Beckman Coulter). Susceptibility to CTZ was determined using gradient strips (Liofilchem®, Werfen). RESULTS: Of 1253 strains isolated, 7% presented MDR. We studied the susceptibility of a total of 78 strains of MDR P. aeruginosa, of which 5 (6.4%) were resistant to CTZ according to the EUCAST criteria. CONCLUSIONS: In our environment, the in vitro resistance to CTZ in MDR P. aeruginosa strains is approximately 6%. CTZ is an option for the treatment of infections by MDR P. aeruginosa when there is no other alternative and its in-vitro susceptibility has been proven.


Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Tazobactam/farmacologia , Espectrometria de Massas , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real , Valores de Referência , Reprodutibilidade dos Testes
15.
Artigo em Inglês | MEDLINE | ID: mdl-31685458

RESUMO

We highlight features associated with bacteriophage therapy that make it an attractive treatment option for multidrug-resistant infections and also discuss some of the challenges that need to be considered in the design and execution of clinical trials directed at evaluating the efficacy of bacteriophage therapy in humans.


Assuntos
Bacteriófagos , Terapia por Fagos , Infecções Relacionadas à Prótese , Antibacterianos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Pseudomonas aeruginosa/efeitos dos fármacos
16.
J Photochem Photobiol B ; 200: 111622, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31678034

RESUMO

Seaweeds are considered to be one of the richest bio-reserves, comprising of numerous bioactive compounds with versatile properties and multiple activities. The present study examined the antibacterial activity of two types of seaweeds, Ulva lactuca (green) and Stoechospermum marginatum (brown) collected from Oman Coastal region against five multidrug-resistant bacteria. The aqueous extracts of the seaweeds showed better antibacterial activity compared to methanol extracts. The results of the antibacterial assay revealed the excellent inhibitory effects of U.lactuca with the maximum activity against E.coli(8 mm) followed by K.pneumonia(4 mm) and S.typhi(2 mm). S.marginatum formed a clear zone of inhibition only against E.coli(3 mm).The major phytochemical constituents identified in both the types of seaweeds were Alkaloids, Terpenoids, Saponins, Flavonoids, and Steroids. Fourier transform infrared spectroscopy (FTIR) results confirmed the presence of alcoholic/phenolic groups, and amide groups in the seaweed extracts. Gas chromatography-mass spectrometry (GC-MS) results evidenced the presence of bioactive compounds such as 5-Octadecenal, 1-Tricosanol, Neophytadiene, Lactaropallidin, Phytol, Fenretinide, Lucenin, Vincadifformine in U.lactuca. Additionally, U.lactuca displayed better antioxidant activity (33.05%) in the DPPH free radical scavenging activity test compared to the S.marginatum (21.51%). Thus, the green seaweed U.lactuca could be considered as a potential source of natural antioxidant and antibacterial agents for food and pharmaceutical products.


Assuntos
Antibacterianos/química , Feófitas/química , Extratos Vegetais/química , Ulva/química , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Antioxidantes/química , Bioprospecção , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Feófitas/metabolismo , Ulva/metabolismo
17.
Nat Commun ; 10(1): 4538, 2019 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-31586049

RESUMO

Antimicrobial peptides (AMPs) are promising antimicrobials, however, the potential of bacterial resistance is a major concern. Here we systematically study the evolution of resistance to 14 chemically diverse AMPs and 12 antibiotics in Escherichia coli. Our work indicates that evolution of resistance against certain AMPs, such as tachyplesin II and cecropin P1, is limited. Resistance level provided by point mutations and gene amplification is very low and antibiotic-resistant bacteria display no cross-resistance to these AMPs. Moreover, genomic fragments derived from a wide range of soil bacteria confer no detectable resistance against these AMPs when introduced into native host bacteria on plasmids. We have found that simple physicochemical features dictate bacterial propensity to evolve resistance against AMPs. Our work could serve as a promising source for the development of new AMP-based therapeutics less prone to resistance, a feature necessary to avoid any possible interference with our innate immune system.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Genoma Bacteriano/efeitos dos fármacos , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/genética , Infecções Bacterianas/tratamento farmacológico , Evolução Molecular Direcionada , Desenvolvimento de Medicamentos/métodos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Genoma Bacteriano/genética , Humanos , Metagenômica , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Mutação Puntual , Microbiologia do Solo
18.
BMC Res Notes ; 12(1): 649, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31590691

RESUMO

OBJECTIVES: This study examines the rationale, if any, behind combining the extracts from the fruits of Alchornea cordifolia and Pterocarpus santalinoides and aerial parts of Cassytha filiformis in the traditional treatment of diarrhoegenic bacterial infections. RESULTS: Four diarrhoegenic bacterial isolates: Salmonella typhi, Shigellae dysenteriae, Escherichia coli and Staphylococcus aureus were used and their antibiotic susceptibility screening showed that they were multi-antibiotic resistant. The extracts exhibited activity against all the test isolates with minimum inhibitory concentration values ranging from 3.125 to 12.5 mg/mL. From the checkerboard assay, the fractional inhibitory concentration indices showed that C. filiformis has antagonistic and indifference activities in combination with either P. santalinoides or A. cordifolia. This showed that the combination of extracts from the fruits of A. cordifolia and P. santalinoides and aerial parts of C. filiformis is counterproductive and invalidates any claim for positive results in the management of diarrhoegenic bacterial infections.


Assuntos
Antibacterianos/farmacologia , Euphorbiaceae/química , Lauraceae/química , Extratos Vegetais/farmacologia , Pterocarpus/química , Antibacterianos/isolamento & purificação , Combinação de Medicamentos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Frutas/química , Testes de Sensibilidade Microbiana , Componentes Aéreos da Planta/química , Extratos Vegetais/isolamento & purificação , Salmonella typhi/efeitos dos fármacos , Shigella dysenteriae/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
20.
BMC Infect Dis ; 19(1): 880, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31640588

RESUMO

BACKGROUND: Antibiotic resistance is a leading cause of treatment failure in Helicobacter pylori infection. In Africa, there are very little data concerning the susceptibility of Helicobacter pylori isolates to antibiotics. The purpose of this study was to evaluate the resistance prevalence of Helicobacter pylori strains circulating in Cameroon, and to assess overexpression of efflux pump as a possible multi-drug resistance mechanisms. METHODS: A total of 140 H. pylori isolates were recovered from gastric biopsies of dyspeptic patients in two reference hospitals in Cameroon and analyzed for their antimicrobial susceptibility to amoxicillin, co-amoxiclav, ampicillin, penicillin, imipenem, metronidazole, rifabutin, erythromycin, clarithromycin, azithromycin, levofloxacin, ciprofloxacin, norfloxacin, tetracycline, doxycycline and minocycline. Antibiotic sensitivity was tested by disk diffusion method. Phe-Arg-naphthylamide (PAßN) was used as efflux pump inhibitor. INT broth microdilution method in supplemented Brain Heart Infusion broth was used to determine the MIC of ampicillin, amoxicillin, metronidazole, erythromycin, clarithromycin and doxycycline in the absence and the presence of PAßN against 32 selected MDR isolates. RESULTS: Overall H. pylori resistance rate was 100% to ampicillin, penicillin and co-amoxiclav; 97.14% to amoxicillin, 97.85% to metronidazole, 47.85% to erythromycin, 13.57% to clarithromycin; 5, 2.86 and 0.71% to doxycycline, tetracycline and minocycline respectively. No resistance to azithromycin, rifabutin, imipenem, ciprofloxacin, norfloxacin and levofloxacin was detected among H. pylori isolates. Seventy percent (70%) of the tested isolates elicited a multiple drugs resistance pattern; 42.57% double, 15.71% triple and 5.71% quadruple drugs resistance. Metronidazole and amoxicillin were more concerned with double resistance pattern (86.76%). The spectrum of activity recorded with metronidazole, doxycycline, clarithromycin and erythromycin ranged from 0 to 100% in the absence to the presence of PAßN against the tested MDR isolates. An 8 to 128-fold increase in potency was also noticed with these antibiotics in the presence of PAßN. CONCLUSION: With regard to the high resistance rate to both amoxicillin and metronidazole, these drugs should be avoided as components of triple therapy in our milieu. In contrast, ciprofloxacin, norfloxacin, levofloxacin and tetracyclines could be used to achieve a better eradication rate and to reduce the risk of selection of H. pylori resistant strains.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Dispepsia/microbiologia , Infecções por Helicobacter/microbiologia , Helicobacter pylori/efeitos dos fármacos , Adulto , Antibacterianos/uso terapêutico , Biópsia , Camarões , Estudos Transversais , Dipeptídeos/farmacologia , Feminino , Infecções por Helicobacter/tratamento farmacológico , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Testes de Sensibilidade Microbiana
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