Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
1.
J Appl Microbiol ; 135(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38449342

RESUMO

Cholera, caused by Vibrio cholerae, is a severe diarrheal disease that necessitates prompt diagnosis and effective treatment. This review comprehensively examines various diagnostic methods, from traditional microscopy and culture to advanced nucleic acid testing like polymerase spiral reaction and rapid diagnostic tests, highlighting their advantages and limitations. Additionally, we explore evolving treatment strategies, with a focus on the challenges posed by antibiotic resistance due to the activation of the SOS response pathway in V. cholerae. We discuss promising alternative treatments, including low-pressure plasma sterilization, bacteriophages, and selenium nanoparticles. The paper emphasizes the importance of multidisciplinary approaches combining novel diagnostics and treatments in managing and preventing cholera, a persistent global health challenge. The current re-emergent 7th pandemic of cholera commenced in 1961 and shows no signs of abeyance. This is probably due to the changing genetic profile of V. cholerae concerning bacterial pathogenic toxins. Given this factor, we argue that the disease is effectively re-emergent, particularly in Eastern Mediterranean countries such as Lebanon, Syria, etc. This review considers the history of the current pandemic, the genetics of the causal agent, and current treatment regimes. In conclusion, cholera remains a significant global health challenge that requires prompt diagnosis and effective treatment. Understanding the history, genetics, and current treatments is crucial in effectively addressing this persistent and re-emergent disease.


Assuntos
Bacteriófagos , Cólera , Vibrio cholerae , Humanos , Cólera/diagnóstico , Cólera/epidemiologia , Cólera/prevenção & controle , Vibrio cholerae/genética , Bacteriófagos/fisiologia , Filogenia , Toxina da Cólera/genética , Toxina da Cólera/metabolismo
2.
J Appl Microbiol ; 134(2)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36724268

RESUMO

AIM: To investigate the effect of adapting Klebsiella pneumoniae clinical isolates harboring ESBL genes to cetrimide (CT) in terms of subsequent cross-resistance to other biocides and antibiotics, and to investigate changes to virulence markers, such as biofilm formation and efflux activity. The changes between phenotypic extended spectrum ß-lactamases (pESBL) expressing isolates and non-phenotypic ESBL (npESBL) isolates was compared. METHODS AND RESULTS: Kl. pneumoniae isolates (14 pESBL and 17 npESBL) were adapted to increasing concentrations of CT, until 4 × MIC was reached. The MIC of the adapted isolates was tested against chloroxylenol (CX) and chlorhexidine. Disk diffusion techniques were used to determine the susceptibility of the isolates to different antibiotics. Biofilm formation was assessed for the isolates using the crystal violet method and efflux pump activity was studied using the ethidium bromide assay. After CT adaptation, 100% of npESBL isolates and 85.7% of pESBL isolates showed increase in CT MIC after CT adaptation. While 41.2% of npESBL and 57.1% of the pESBL isolates showed a cross-resistance with chlorhexidine. CT adaptation resulted in a significant decrease in the susceptibility of npESBL isolates to aztreonam and cefotaxime compared to pESBL isolates, which could be linked to the increase in efflux activity of npESBL compared to pESBL. Biofilm formation was significantly increased after CT adaptation regardless of the type of isolate. CONCLUSIONS: The extensive use of biocides in the environment can induce cross-resistance to other biocides and antibiotics, and can increase the ability of bacteria to form biofilms. The response of bacteria to biocide adaptation differs between pESBL and npESBL isolates, although the effect is strain specific.


Assuntos
Desinfetantes , Klebsiella pneumoniae , Clorexidina/farmacologia , beta-Lactamases/genética , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Desinfetantes/farmacologia
3.
J Appl Microbiol ; 132(5): 3951-3958, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35187773

RESUMO

AIMS: Despite a decline in tobacco smoking in the developed world, the developing world has witnessed an increase in such activity over recent years. An increase in antibiotic resistance has accompanied this increase in tobacco use, and we suggest that the two may be linked. This study aims to investigate the effect of cigarette smoke exposure on bacterial virulence and susceptibility to antibiotics. METHODS AND RESULTS: Pseudomonas aeruginosa passaged in the presence of Cigarette Smoke Condensate (CSC) exhibited reduced susceptibility towards Amikacin (p = 0.02), Tobramycin (p = 0.03) and Aztreonam (p = 0.007) and was accompanied by changes in growth dynamics as exposure to CSC increased. These observed changes persisted after passaging bacteria in CSC-free medium for 10 days. The genotoxicity of CSC on P. aeruginosa was evaluated by the standard Comet assay, which demonstrated DNA damage in the P. aeruginosa genome in Passage 15 compared to the CSC-unexposed cells. Gene expression analysis on selected virulence and quorum sensing genes showed that both flagellar (fliC and fleR) and quorum sensing (lasI/R and rhII) genes were significantly up-regulated in Passage 15. CONCLUSIONS: Results confirm the genotoxic effect of cigarette smoke manifested in an increased antibiotic resistance, coupled with increased bacterial virulence SIGNIFICANCE AND IMPACT OF STUDY: This study is the first to elucidate a clear link between tobacco smoke residues and both increases in antibiotic resistance and the up-regulation of bacterial virulence markers.


Assuntos
Fumar Cigarros , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Percepção de Quorum , Nicotiana , Virulência
4.
J Appl Microbiol ; 132(1): 41-58, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34218488

RESUMO

Chitosan is an abundant organic polysaccharide, which can be relatively easily obtained by chemical modification of animal or fungal source materials. Chitosan and its derivatives have been shown to exhibit direct antiviral activity, to be useful vaccine adjuvants and to have potential anti-SARS-CoV-2 activity. This thorough and timely review looks at the recent history of investigations into the role of chitosan and its derivatives as an antiviral agent and proposes a future application in the treatment of endemic SARS-CoV-2.


Assuntos
COVID-19 , Quitosana , Adjuvantes de Vacinas , Animais , Antivirais/farmacologia , Quitosana/farmacologia , Humanos , SARS-CoV-2
5.
J Community Health ; 47(3): 416-424, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35076804

RESUMO

Asymptomatic carriage of methicillin-resistant Staphylococci (MRS) may allow for the unseen dissemination of antibiotic-resistant strains through the population. This study investigates the prevalence and epidemiological risk factors that contribute to the spread of MRS in a university setting in Amman, Jordan. A cross-sectional questionnaire-based study was performed in December 2019. Five hundred and four students enrolled in the study and provided skin and nasal swabs. Swabs were then processed to isolate MRS on Mannitol Salt Agar (MSA) + 4 µg/ml oxacillin. Isolates were tested for their antibiotic susceptibility using the disc diffusion assay. Epidemiological risk assessment was performed using the Chi-square test and univariate and multivariant analysis. The percentage carriage of MRS in the 504 students was 40.4%. The carriage rate of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) from the skin and nasal areas was 13.5% and 26.9%, respectively. The percentage of male carriers was significantly higher than females, and the only identified epidemiological risk factor related to the carriage was attendance at a fitness club. All MRS isolates were resistant to oxacillin (100%), cefoxitin (45.5%), erythromycin (35.2%), gentamycin (10.2%), ciprofloxacin (12.7%), nitrofurantoin (12.2%), linezolid (7.8%), amikacin (1.47%), and Vancomycin (0.49%). 42% of MRS expressed a multiple antibiotic resistance (MAR) index above 0.2. Three isolates expressed a MAR index of 0.8. MRS has been exhibited to be present in an otherwise healthy population of students, which may then act as a reservoir for MAR strains.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Antibacterianos/farmacologia , Estudos Transversais , Feminino , Humanos , Masculino , Resistência a Meticilina , Oxacilina , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Staphylococcus , Estudantes
6.
Artigo em Inglês | MEDLINE | ID: mdl-38700762

RESUMO

The complex relationship between probiotics and human health goes beyond their traditional function in gut health, generating considerable interest for their broad potential in disease treatment. This review explores the various functions of probiotics, highlighting their impact on the immune system, their benefits for gut and oral health, their effects on metabolic and neurological disorders, and their emerging potential in cancer therapy. We give significant importance to studying the effects of probiotics on the gut-brain axis, revealing new and non-invasive therapeutic approaches for complex neurological disorders. In addition, we expand the discussion to encompass the impact of probiotics on the gut-liver and gut-lung axes, recognizing their systemic effects and potential in treating respiratory and hepatic conditions. The use of probiotic "cocktails" to improve cancer immunotherapy outcomes indicates a revolutionary approach to oncological treatments. The review explores the specific benefits associated with various strains and the genetic mechanisms that underlie them. This study sets the stage for precision medicine, where probiotic treatments can be tailored to meet the unique needs of each patient. Recent developments in delivery technologies, including microencapsulation and nanotechnology, hold great potential for enhancing the effectiveness and accuracy of probiotic applications in therapeutic settings. This study provides a strong basis for future scientific research and clinical use, promoting the incorporation of probiotics into treatment plans for a wide range of diseases. This expands our understanding of the potential benefits of probiotics in modern medicine.

7.
Int J Occup Environ Health ; 19(3): 207-14, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23885773

RESUMO

BACKGROUND: Pharmaceutical manufacturing workers are exposed to significant amounts of product ingredients, including antibiotics. Such exposure could affect their nasal microflora. OBJECTIVE: To assess the effect of exposure to various unidentified pharmaceutical ingredients in cephalosporin-manufacturing and non-cephalosporin plants on the nasal carriage of Staphylococcus spp. and their antibiotic resistance. METHODS: Nasal swab samples were collected from 39 workers in both plants on three different occasions. Staphylococci were isolated and identified to genus level. Antibiotic resistance profiles were determined and subsequent identification to species level was performed. RESULTS: There was complete absence of S. aureus in the samples collected from workers in both facilities. Multiple drug resistant coagulase-negative staphylococci (MDR CONS) prevalence rates were higher in the non-cephalosporin plant than in the cephalosporin plant, with resistance towards six classes of antibiotics. S. epidermidis was the prevalent species in the non-cephalosporin plant and S. haemolyticus prevailed in the cephalosporin-producing plant. CONCLUSIONS: The observed prevalence of CONS in both production plants was the same. However, exposure to intermittent non-cephalosporin pharmaceuticals results in higher prevalence of MDR CONS compared to continuous exposure to cephalosporin.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Indústria Farmacêutica , Doenças Profissionais/microbiologia , Exposição Ocupacional/análise , Infecções Estafilocócicas/microbiologia , Staphylococcus/isolamento & purificação , Cefalosporinas/farmacologia , Farmacorresistência Bacteriana , Excipientes/farmacologia , Humanos , Cavidade Nasal/microbiologia , Staphylococcus/classificação , Staphylococcus/efeitos dos fármacos
8.
Antonie Van Leeuwenhoek ; 99(3): 559-66, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20967498

RESUMO

Streptococcus pneumoniae is an important human bacterial pathogen, and the increase in antibiotic resistance demands the development of new antimicrobial compounds. Several reports have suggested that yeast killer toxins show activity against bacteria and we therefore investigated the activity of K9 killer toxin from the yeast Williopsis saturnus var. mrakii NCYC 500 against S. pneumoniae. However, no inhibition of bacterial growth was observed with concentrated K9 preparations in agar diffusion assays and in liquid culture. Although cell morphology was slightly affected by K9 treatment, no effect on cellular viability was detectable, and K9 had no stimulatory effect on cell lysis induced by ß-lactams or Triton X-100. This indicated that K9 did not contribute to cell wall damage. Moreover, flow cytometry was used as a sensitive assessment of integrity of cells exposed to killer toxin. No significant damage of S. pneumoniae cells was evident, although minor changes in fluorescence suggested that K9 killer toxin may interact with bacterial surface components.


Assuntos
Anti-Infecciosos/farmacologia , Fatores Matadores de Levedura/farmacologia , Streptococcus pneumoniae/efeitos dos fármacos , Williopsis/metabolismo , Anti-Infecciosos/metabolismo , Citometria de Fluxo , Fatores Matadores de Levedura/metabolismo
9.
J Pediatr Surg ; 54(1): 189-193, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30355460

RESUMO

BACKGROUND/PURPOSE: We initiated a pediatric surgical program including a caregiver for the induction of anesthesia. We measured preoperative midazolam administration, preoperative time, induction time, and program satisfaction. METHODS: Families with children undergoing surgery during the study period were included. Preoperative midazolam administration, preoperative time, and induction time were compared between participants and controls. Satisfaction surveys were given to participating caregivers and staff. RESULTS: The rate of preoperative midazolam use decreased from 41% (392/964) to 13% (16/118) among participants vs controls (p < 0.0001). After linear regression analysis, this difference persisted as an adjusted odds ratio of 0.29 (95% CI = 0.16-0.52). Preoperative and induction times (minutes) were similar between groups (76.2 vs 82.2, 13.8 vs 16.2, p = nonsignificant). Based on 5-point Likert surveys, the program was rated as "beneficial" or "very beneficial" to the patient by caregivers (99.2%) and staff (77.5%). Caregivers stated it "reduced" or "greatly reduced" anxiety for them (87.1%) and their child (93.2%). CONCLUSIONS: Opponents of similar programs suggest familial presence slows care and is disruptive. Our program decreased utilization of preoperative anxiolytics with no effect on operating room efficiency. Both hospital staff and participants felt the program was beneficial to the patient. Perceived caregiver and child anxiety was reduced. TYPE OF STUDY: Treatment study. LEVEL OF EVIDENCE: Level III.


Assuntos
Adjuvantes Anestésicos/administração & dosagem , Anestesia/métodos , Midazolam/administração & dosagem , Assistência Centrada no Paciente/métodos , Atitude do Pessoal de Saúde , Criança , Pré-Escolar , Família , Feminino , Humanos , Lactente , Masculino , Satisfação do Paciente/estatística & dados numéricos , Estudos Retrospectivos , Inquéritos e Questionários
10.
Int J Pharm ; 454(1): 226-32, 2013 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-23830945

RESUMO

Microemulsions are physically stable oil/water clear dispersions, spontaneously formed and thermodynamically stable. They are composed in most cases of water, oil, surfactant and cosurfactant. Microemulsions are stable, self-preserving antimicrobial agents in their own right. The observed levels of antimicrobial activity associated with microemulsions may be due to the direct effect of the microemulsions themselves on the bacterial cytoplasmic membrane. The aim of this work is to study the growth behaviour of different microbes in presence of certain prepared physically stable microemulsion formulae over extended periods of time. An experiment was designed to study the kinetics of killing of a microemulsion preparation (17.3% Tween-80, 8.5% n-pentanol, 5% isopropyl myristate and 69.2% sterile distilled water) against selected test microorganisms (Candida albicans, Aspergillus niger, Schizosaccharomyces pombe and Rhodotorula spp.). Secondly, an experiment was designed to study the effects of the microemulsion preparation on the cytoplasmic membrane structure and function of selected fungal species by observation of 260 nm component leakage. Finally, the effects of the microemulsion on the fungal membrane structure and function using S. pombe were studied using transmission electron microscopy. The results showed that the prepared microemulsions are stable, effective antimicrobial systems with effective killing rates against C. albicans, A. niger, S. pombe and Rhodotorula spp. The results indicate a proposed mechanism of action of significant anti-membrane activity, resulting in the gross disturbance and dysfunction of the cytoplasmic membrane structure which is followed by cell wall modifications, cytoplasmic coagulation, disruption of intracellular metabolism and cell death.


Assuntos
Antifúngicos/farmacologia , Fungos/efeitos dos fármacos , Antifúngicos/química , Aspergillus niger/efeitos dos fármacos , Aspergillus niger/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Membrana Celular/efeitos dos fármacos , Membrana Celular/ultraestrutura , Química Farmacêutica , Emulsões , Fungos/crescimento & desenvolvimento , Fungos/ultraestrutura , Cinética , Microscopia Eletrônica de Transmissão , Miristatos/química , Miristatos/farmacologia , Pentanóis/química , Pentanóis/farmacologia , Polissorbatos/química , Polissorbatos/farmacologia , Rhodotorula/efeitos dos fármacos , Rhodotorula/crescimento & desenvolvimento , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/crescimento & desenvolvimento , Espectrofotometria , Tecnologia Farmacêutica/métodos , Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA