RESUMO
Aim: To evaluate the action of promethazine, fluoxetine and carbonyl cyanide 3-chlorophenylhydrazone as efflux pump inhibitors (EPIs) against multidrug-resistant Pseudomonas aeruginosa. Methods: The effect of the compounds was evaluated in planktonic cells and bacterial biofilms. Accumulation tests were performed with ethidium bromide to prove their action as EPIs. Then, they were associated with antimicrobials. Results: Effect on planktonic cells and biofilms was found. Assays with ethidium bromide indicate their action as EPIs. Significant reductions in the metabolic activity of biofilms were observed after the association with the antimicrobials, especially for meropenem. Conclusion: It is possible to prove the action of these compounds as EPIs for P. aeruginosa and demonstrate the relevance of efflux pumps in antimicrobial resistance.
[Box: see text].
Assuntos
Antibacterianos , Biofilmes , Reposicionamento de Medicamentos , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa , Pseudomonas aeruginosa/efeitos dos fármacos , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Prometazina/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Humanos , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/antagonistas & inibidores , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , HidrazonasRESUMO
Freshwater cetaceans play a significant role as sentinel animals, providing important data on animal species and aquatic ecosystem health. They also may serve as potential reservoirs of emerging pathogens and host virulence genes in their microbiota. In this study, we evaluated virulence factors produced by Gram-negative bacteria recovered from individuals belonging to two populations of free-ranging Amazon river dolphins (Inia geoffrensis). A total of 132 isolates recovered from the oral cavity, blowhole, genital opening and rectum of 21 river dolphins, 13 from Negro River and 8 from Tapajós River, Brazil, were evaluated for the production of virulence factors, such as biofilms and exoproducts (proteases, hemolysins and siderophores), in planktonic and biofilm forms. In planktonic form, 81.1% (107/132) of the tested bacteria of free-ranging Amazon river dolphins were able to produce virulence factors, with 44/132 (33.4%), 65/132 (49,2%) and 54/132 (40,9%) positive for protease, hemolysin and siderophore production, respectively. Overall, 57/132 (43.2%) of the isolates produced biofilms and, under this form of growth, 66/132 (50%), 88/132 (66.7%) and 80/132 (60.6%) of the isolates were positive for protease, hemolysin and siderophore production. In general, the isolates showed a higher release of exoproducts in biofilm than in planktonic form (P < 0.001). The present findings show that Amazon river dolphins harbor potentially pathogenic bacteria in their microbiota, highlighting the importance of monitoring the micro-organisms from wild animals, as they may emerge as pathogens for humans and other animals.
Assuntos
Golfinhos , Humanos , Animais , Fatores de Virulência/genética , Ecossistema , Proteínas Hemolisinas , Sideróforos , Bactérias Gram-Negativas , Peptídeo HidrolasesRESUMO
Paraquat (1,10-dimethyl-4,4-bipyridinium dichloride; PQ) is a free-radical producing herbicide that affects cell membranes and can upset the environmental balance of microorganisms present in soil, such as Cryptococcus spp. This study aimed to evaluate the in vitro activity of PQ against Cryptococcus spp. in planktonic and biofilm forms, as well as the protective effect of antioxidant agents against the antifungal effect of PQ and the kinetics of melanin production in response to PQ. Susceptibility to PQ was evaluated by microdilution. Cryptococcus sp. strains exposed to PQ were grown in media with ascorbic acid (AA) and glutathione (GSH). Melanin production was assessed in the presence of l-3,4-dihydroxyphenylalanine (l-DOPA) + PQ. The minimum inhibitory concentration of PQ against Cryptococcus spp. ranged from 8 to 256 µg/mL. Furthermore, PQ reduced biofilm formation. AA and GSH restored the fungal growth of Cryptococcus spp. exposed to PQ. In addition, l-DOPA + PQ delayed melanin production by 24 and 48 h for C. deuterogattii and C. neoformans sensu lato, respectively, suggesting that PQ induces a fitness trade-off in melanin production. Taken together, our data suggest that the antifungal effect of PQ against Cryptococcus spp. possibly exerts selective pressures interfering with biofilm formation and melanin production by these yeasts.
Assuntos
Cryptococcus gattii , Cryptococcus neoformans , Herbicidas , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Cryptococcus gattii/metabolismo , Cryptococcus neoformans/metabolismo , Herbicidas/metabolismo , Herbicidas/farmacologia , Levodopa/metabolismo , Levodopa/farmacologia , Melaninas/metabolismo , Melaninas/farmacologia , Testes de Sensibilidade Microbiana , Paraquat/metabolismo , Paraquat/farmacologiaRESUMO
Studies on the microbiota of freshwater cetaceans are scarce and may provide important data on animal and environmental health. This study aimed to evaluate the antimicrobial susceptibility of Gram-negative bacteria recovered from two populations of free-ranging Amazon river dolphins (Inia geoffrensis). Twenty-one animals were captured and released, 13 from Negro River and 8 from Tapajós River, Brazil. Swab samples were obtained from the oral cavity, blowhole, genital opening and rectum and were cultured on MacConkey agar. Isolates were biochemically identified, and antimicrobial susceptibility was assessed by disk diffusion method. Overall, 132 isolates were recovered, of which 71 were recovered from animals from Negro River and 61 from Tapajós River. The most commonly recovered bacterial species were Enterobacter cloacae, Morganella morganii, Klebsiella pneumoniae and Pseudomonas aeruginosa. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed (P < 0.001). The results indicate that free-ranging Amazon river dolphins host resistant bacteria, contributing for their maintenance in the environment. This study highlights the importance of the One Health approach to monitor the emergence of antimicrobial resistance. Summary Gram-negative bacteria recovered from 21 free-ranging Amazon river dolphins (Inia geoffrensis) from the Negro River and the Tapajós River populations were evaluated for their antimicrobial susceptibility. Overall, 51.6% (63/122) of the isolates were not-susceptible (intermediate resistance and resistance), of which 28/122 (22.9%) were resistant to at least one antimicrobial. Cephalothin, cefuroxime and cefepime were the drugs to which more resistant and intermediate results were observed. Thus, free-ranging Amazon river dolphins, never treated with antimicrobials, host resistant bacteria, contributing for their maintenance in the environment and highlighting the importance of the One Health approach to monitor the emergence of antimicrobial resistance.
Assuntos
Golfinhos , Saúde Única , Animais , Antibacterianos/farmacologia , Bactérias , Farmacorresistência Bacteriana , Testes de Sensibilidade MicrobianaRESUMO
This study aimed to evaluate the in vitro effect of aloe emodin, barbaloin and chrysophanol on growing and mature biofilms of Cryptococcus neoformans sensu stricto. The compounds were added at the moment of inducing biofilm growth or after growth for 72 h to evaluate their effects on growing and mature biofilms, respectively. Then, biofilm biomass was evaluated by crystal violet staining and metabolic activity by the XTT reduction assay. Morphological alterations were also evaluated by laser scanning confocal microscopy. Aloe emodin and barbaloin affected growing biofilms and disrupted mature biofilms, reducing metabolic activity by > 60% and biomass by > 70%. Chrysophanol only inhibited mature biofilms, but to a lesser extent. In conclusion, anthraquinones, especially aloe emodin and barbaloin, show a relevant effect against growing and mature biofilms of C. neoformans sensu stricto.
Assuntos
Aloe , Cryptococcus neoformans , Emodina , Antraquinonas/farmacologia , Biofilmes , Emodina/farmacologiaRESUMO
Abstract Mycetoma is a chronic and slow-developing granulomatous disease characterized by the triad of large painless tumour-like subcutaneous swellings, the formation of sinuses, and discharge that usually contains grains. Phellinus spp. are saprophytic wood-decaying filamentous basidiomycetes. They are an under-recognised cause of invasive fungal infections and are rarely reported worldwide. We report a 59-year-old male patient with mycetoma caused by Phellinus spp. The diagnosis was confirmed with clinical examination, magnetic resonance imaging (MRI) study, soft tissue and bone biopsy culture, and polymerase chain reaction. To the best of our knowledge, this is the first reported case of mycetoma due to Phellinus spp. without chronic granulomatous disease (CGD).
Resumen El micetoma es una enfermedad granulomatosa crónica y de lento desarrollo caracterizada por la tríada de grandes inflamaciones subcutáneas similares a tumores indoloras, la formación de los senos nasales y secreción que generalmente contiene granos. Phellinus spp. son basidiomicetos filamentosos saprofitos que descomponen la madera. Son un poco reconocido causa de infecciones fúngicas invasivas y rara vez se informan en todo el mundo. Presentamos un paciente masculino de 59 años con micetoma causado por Phellinus spp. El diagnostico se confirmó con examen clínico, estudio de resonancia magnética (RM), cultivo de biopsia de tejido blando y óseo y reacción en cadena de la polimerasa. A lo mejor que sepamos, este es el primer caso reportado de micetoma debido a Phellinus spp. sin enfermedad granulomatosa crónica (EGC).
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Basidiomycota , Phellinus , Micetoma , Brasil , Reação em Cadeia da Polimerase , Infecções Fúngicas Invasivas , MicosesRESUMO
This study proposes a microcosm biofilm (MiB) model for the study of vulvovaginal candidiasis (VVC). Different conditions that mimic the vaginal environment were tested for MiB formation. The best growth conditions were obtained with samples incubated in vaginal fluid simulator medium pH 4.5 at 35 °C under a microaerophilic atmosphere. MiBs were evaluated for growth kinetics, fluconazole susceptibility and morphology. Samples containing high numbers of bacteria were analyzed for metagenomics. At 48 h, MiBs presented a higher cell density (CFU ml-1), a higher biomass and tolerance to fluconazole than their corresponding monospecies biofilms. Morphological analysis of MiBs revealed blastoconidia preferentially adhered to epithelial cells. Abundant Lactobacillus spp. were detected in two clinical samples; their MiBs showed a lower biomass and a higher fluconazole susceptibility. The proposed model proved to be a useful tool for the study of the complex microbial relationship in the vaginal environment, and may help to find new strategies for VVC control.
Assuntos
Antifúngicos/uso terapêutico , Biofilmes , Candidíase Vulvovaginal/tratamento farmacológico , Candida albicans , Feminino , Fluconazol , Humanos , Testes de Sensibilidade MicrobianaRESUMO
Sporotrichosis, caused by Sporothrix schenckii complex species, is the most prevalent subcutaneous mycosis in many areas of Latin America. Chitosan has been used as an antifungal agent; however the effects of the molecular weight (MW) of chitosan (i.e. high (HMW), medium (MMW) and low (LMW) molecular weight chitosan) on S. brasiliensis has not been well described, particularly on biofilms. Effects on the planktonic form activity of S. brasiliensis were quantified by broth microdilution, while anti-biofilm activity was quantified by measuring metabolic activity via XTT (2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide and biomass formation (crystal violet). The molecular weight of chitosan modulated its effect on the planktonic form of S. brasiliensis, presenting lower MIC values for LMW chitosan. With regards both the adhesive and mature phases of biofilm, the LMW chitosan reduced biomass and metabolic activity most effectively. This study confirms the effects of the molecular weight and deacetylation degree of chitosan on its antifungal properties for potentially pathogenic fungi.
Assuntos
Biofilmes/efeitos dos fármacos , Quitosana/farmacologia , Sporothrix/efeitos dos fármacos , Quitosana/química , Humanos , Peso Molecular , Plâncton/efeitos dos fármacos , Sporothrix/crescimento & desenvolvimento , Esporotricose/tratamento farmacológico , Esporotricose/patologiaRESUMO
OBJECTIVES: This study aimed to assess the biofilm-forming ability of Candida spp. from the ocular conjunctiva of horses and to investigate the antifungal susceptibility of these biofilms. PROCEDURES: Initially, the biofilm-forming ability of 15 strains was assessed by crystal violet staining, which reveals the fungal biomass adhered to the polystyrene plates, and scanning electron microscopy. Then, the minimum inhibitory concentrations (MICs) of amphotericin B, fluconazole, itraconazole, and caspofungin were initially determined against strains in planktonic form. Afterward, antifungal susceptibility of mature biofilms was evaluated by exposing them to 10 × MIC and 50 × MIC of the tested drugs, followed by the assessment of their metabolic activity, using the oxidoreduction indicator XTT. Results were analyzed through ANOVA and Tukey's post-test, and P-values below 5% led to significant conclusions. RESULTS: Eight strains produced biofilms and were classified as strong (1/15), moderate (3/15) and weak (4/15) producers, according to the amount of crystal violet retained by the adhered fungal biomass. Biofilm metabolic activity of one C. tropicalis did not decrease after exposure to the tested antifungals, while biofilm metabolic activity of five strains was reduced by amphotericin B, but not the other drugs. One C. parapsilosis sensu stricto and one C. glabrata showed significant reduction in biofilm metabolic activity after exposure to fluconazole, itraconazole, and caspofungin, but not amphotericin B. CONCLUSIONS: The results demonstrate that Candida from the ocular conjunctiva of horses can pose as a risk to animal health as they are capable of forming biofilms, which are commonly involved in fungal keratitis.
Assuntos
Antifúngicos/farmacologia , Azóis/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Túnica Conjuntiva/microbiologia , Anfotericina B/farmacologia , Animais , Candida/classificação , Candida/fisiologia , Candida/ultraestrutura , Caspofungina , Equinocandinas/farmacologia , Infecções Oculares Fúngicas/microbiologia , Infecções Oculares Fúngicas/veterinária , Fluconazol/farmacologia , Doenças dos Cavalos/microbiologia , Cavalos , Itraconazol/farmacologia , Ceratite/microbiologia , Ceratite/veterinária , Lipopeptídeos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
This work aimed at evaluating the antifungal susceptibility and production of virulence factors by Candida spp. isolated from sirenians in Brazil. The isolates (n = 105) were recovered from the natural cavities of Amazonian and West Indian manatees and were tested for the susceptibility to amphotericin B, itraconazole, and fluconazole and for the production of phospholipases, proteases, and biofilm. The minimum inhibitory concentrations (MICs) for amphotericin B ranged from 0.03 to 1 µg/mL, and no resistant isolates were detected. Itraconazole and fluconazole MICs ranged from 0.03 to 16 µg/mL and from 0.125 to 64 µg/mL, respectively, and 35.2% (37/105) of the isolates were resistant to at least one of these azole drugs. Concerning the production of virulence factors, phospholipase activity was observed in 67.6% (71/105) of the isolates, while protease activity and biofilm production were detected in 50.5% (53/105) and 32.4% (34/105) of the isolates, respectively. Since the natural cavities of manatees are colonized by resistant and virulent strains of Candida spp., these animals can act as sources of resistance and virulence genes for the environment, conspecifics and other animal species, demonstrating the potential environmental impacts associated with their release back into their natural habitat.
Assuntos
Candida/patogenicidade , Trichechus manatus/parasitologia , Animais , Brasil , Saúde Ambiental , Testes de Sensibilidade Microbiana , VirulênciaRESUMO
OBJECTIVE: To investigate the in vitro antimicrobial potential of extracts of stem, leaves, flowers, pods and seeds of Moringa oleifera (M. oleifera) against Vibrio spp. from hatchery water and the prawn Macrobrachium amazonicum. METHODS: The ethanol extracts of stem, leaves, pods and seeds and chloroform extract of flowers of M. oleifera were tested against Vibrio cholerae (V. cholerae) serogroups non-O1/non-O139 (n = 4), Vibrio vulnificus (n = 1) and Vibrio mimicus (n = 1). Escherichia coli (E. coli) (ATCC(®) 25922) was used as quality control. Vibrio species were obtained from Macrobrachium amazonicum prawns and from hatchery water from prawn farming. The Minimum Inhibitory Concentration (MIC) was determined by broth microdilution method. RESULTS: The best result was obtained with the ethanol extract of pods, which inhibited three strains of the V. cholerae, Vibrio vulnificus, Vibrio mimicus and E. coli (MIC range 0.312-5.000 mg/mL). The chloroform extract of flowers was effective against all V. cholerae strains and E. coli (MIC range 0.625-1.250 mg/mL). However, the ethanol extracts of stem and seeds showed low effectiveness in inhibiting the bacterial growth. CONCLUSIONS: The extracts of pods, flowers and leaves of M. oleifera have potential for the control of Vibrio spp. Further studies are necessary to isolate the bioactive compounds responsible for this antimicrobial activity.