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1.
Emerg Microbes Infect ; 8(1): 1406-1415, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31544591

RESUMO

Vibrio vulnificus is a halophilic estuarine bacterium causing severe opportunistic infections. To successfully establish an infection, V. vulnificus must adapt to redox fluctuations in vivo. In the present study, we show that deletion of V. vulnificus fexA gene caused hypersensitivity to acid and reactive oxygen species. The ΔfexA mutant exhibited severe in vivo survival defects. For deeper understanding the role of fexA gene on the successful V. vulnificus infection, we analyzed differentially expressed genes in ΔfexA mutant in comparison with wild type under aerobic, anaerobic or in vivo culture conditions by genome-scale DNA microarray analyses. Twenty-two genes were downregulated in the ΔfexA mutant under all three culture conditions. Among them, cydAB appeared to dominantly contribute to the defective phenotypes of the ΔfexA mutant. The fexA deletion induced compensatory point mutations in the cydAB promoter region over subcultures, suggesting essentiality. Those point mutations (PcydSMs) restored bacterial growth, motility, cytotoxicity ATP production and mouse lethality in the ΔfexA mutant. These results indicate that the cydAB operon, being regulated by FexA, plays a crucial role in V. vulnificus survival under redox-fluctuating in vivo conditions. The FexA-CydAB axis should serve an Achilles heel in the development of therapeutic regimens against V. vulnificus infection.


Assuntos
Proteínas de Bactérias/genética , Grupo dos Citocromos d/genética , Regulação Bacteriana da Expressão Gênica , Oxirredutases/genética , Vibrio vulnificus/genética , Ácidos/farmacologia , Animais , Animais Recém-Nascidos , Regulação para Baixo , Deleção de Genes , Peróxido de Hidrogênio/farmacologia , Dose Letal Mediana , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Mutação Puntual , Ratos , Vibrioses/microbiologia , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/crescimento & desenvolvimento
2.
PLoS Negl Trop Dis ; 13(6): e0007478, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31188821

RESUMO

BACKGROUND: Combination therapy with a third-generation cephalosporin (TGC) and a tetracycline analogue is recommended for Vibrio vulnificus infection. The combination of a TGC and ciprofloxacin has synergistic in vitro bactericidal activity against V. vulnificus. No clinical study has compared the standard regimen with TGC plus ciprofloxacin therapy for V. vulnificus infection. METHODS: Patients with a confirmed V. vulnificus infection at two medical centers in Korea from 1991 to 2016 were enrolled in this study. The patients were grouped according to the type of antibiotic administered. A retrospective propensity-score-matched case-control study of patients treated with TGC plus doxycycline or TGC plus ciprofloxacin was performed. The clinical characteristics and outcomes of the patients were analyzed. RESULTS: A total of 218 patients were confirmed to have V. vulnificus septicemia during the study, and the 30-day survival rate was 39% (85/218). The patients were classified into the following six treatment groups: TGC monotherapy (n = 82), TGC plus doxycycline therapy (n = 42), TGC plus ciprofloxacin therapy (n = 39), ciprofloxacin monotherapy (n = 14), other ß-lactam monotherapy (n = 10), and other (n = 31). The survival rates of these groups were as follows: TGC monotherapy (35%), TGC plus doxycycline (38%), TGC plus ciprofloxacin (54%), ciprofloxacin monotherapy (29%), other ß-lactam (20%), and other (39%). The 30-day survival rate showed no significant difference between the TGC plus doxycycline and TGC plus ciprofloxacin groups (log-rank test, P = 0.18). Among the 81 patients treated with TGC plus doxycycline or TGC plus ciprofloxacin, 12 per treatment group were selected by propensity-score matching. There was no significant difference in the baseline characteristics or the frequency of fasciotomy between the two groups. The 30-day survival rate showed no significant difference between the TGC plus doxycycline (50%) and TGC plus ciprofloxacin (67%) groups (log-rank test, P = 0.46). CONCLUSION: Our data suggest that the outcome of TGC plus ciprofloxacin therapy was comparable to that of TGC plus doxycycline therapy in patients with V. vulnificus septicemia.


Assuntos
Antibacterianos/uso terapêutico , Cefalosporinas/uso terapêutico , Ciprofloxacino/uso terapêutico , Doxiciclina/uso terapêutico , Sepse/tratamento farmacológico , Vibrioses/tratamento farmacológico , Vibrio vulnificus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Quimioterapia Combinada/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia , Estudos Retrospectivos , Sepse/microbiologia , Resultado do Tratamento , Vibrioses/microbiologia , Vibrio vulnificus/efeitos dos fármacos , Adulto Jovem
3.
Int J Food Microbiol ; 303: 19-25, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-31112793

RESUMO

The present study aimed to investigate the presence of Vibrio vulnificus in fish captured at the Lagoa dos Patos estuary (RS, Brazil), to establish a correlation between bacterial biofilm formation and sublethal stress, and to assess the resistance of the isolates to antimicrobials and sanitizers. A total of 217 isolates characteristic of Vibrio sp. were analyzed. Isolates were identified and subsequently their ability to form biofilm, the impact of exposure to sublethal stress on their biofilm formation ability, and their resistance to antimicrobial and to sodium hypochlorite and chlorine dioxide sanitizers were evaluated. V. vulnificus was isolated from the fish Paralichthys orbignyanus and Micropogonias furnieri. The bacterial isolates examined were able to form biofilms. Biofilm formation ability of these strains was decreased or inhibited after being exposed to sublethal stress. The isolates were resistant to most antimicrobials. The sanitizer concentrations necessary to eliminate V. vulnificus were higher than those usually used in the fishing industry.


Assuntos
Antibacterianos/farmacologia , Biofilmes , Estuários , Estresse Fisiológico , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/fisiologia , Animais , Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Brasil , Peixes/microbiologia
4.
Nat Prod Res ; 33(23): 3445-3449, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29790361

RESUMO

Sanguisorba officinalis L. is a traditional herbal medicine, which is prevailingly applied to cure hemorrhoids, wounds and ulcers in Eastern Asian countries. The purpose of this study was to investigate the antibacterial and soluble epoxide hydrolase (sEH) inhibitory effects of the extracts and components from S. officinalis. The methanol extract was divided into ethyl acetate (EtOAc), n-butanol (n-BuOH), and water layers. In our screening procedure, the EtOAc and n-BuOH extracts and compounds (1-2) remarkably suppressed the growth of V. vulnificus in a dose-dependent manner. In addition, the EtOAc extract and compound 1 exhibited significant inhibitory effect on the V. vulnificus induced cytotoxicity on HeLa cells. Furthermore, compound 4 displayed an inhibition against sEH with an IC50 value of 7.0 ± 0.5 µM. A kinetic analysis demonstrated that the inhibitory effect of compound 4 was a mixed type, with an inhibitory constant (Ki) 0.22 ± 0.0 µM.


Assuntos
Antibacterianos/isolamento & purificação , Epóxido Hidrolases/antagonistas & inibidores , Sanguisorba/química , Vibrio vulnificus/efeitos dos fármacos , Antibacterianos/farmacologia , Ásia , Células HeLa , Humanos , Cinética , Extratos Vegetais/farmacologia , Vibrio vulnificus/patogenicidade
5.
Appl Environ Microbiol ; 84(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30030231

RESUMO

Vibrio vulnificus and Vibrio parahaemolyticus are important human pathogens that are frequently transmitted via consumption of contaminated raw oysters. A small amount of d-tryptophan (d-Trp) inhibits some foodborne pathogenic bacteria in high-salt environments. In this study, we aimed to evaluate the antibacterial effect of d-Trp on V. vulnificus and V. parahaemolyticus in culture media, artificial seawater, and shucked and live oysters. The effectiveness of d-Trp in growth inhibition of Vibrio spp. was highly dependent on environmental NaCl concentrations. Higher levels of NaCl (>4.0%) with d-Trp (>20 mM) resulted in higher and more consistent growth inhibition of both Vibrio spp. Treatment with 40 mM d-Trp significantly (P < 0.05) reduced viable V. parahaemolyticus cell counts in tryptic soy broth (TSB) with >4.0% NaCl at 25°C. In contrast, V. vulnificus was more sensitive to d-Trp (20 mM) than V. parahaemolyticus d-Trp (40 mM) treatment with NaCl (>4.5%) significantly (P < 0.05) inhibited the growth of V. parahaemolyticus and V. vulnificus in shucked oysters immersed in peptone water at 25°C throughout a 48-h incubation period. In artificial seawater, d-Trp exhibited a stronger growth-inhibitory effect on V. vulnificus and V. parahaemolyticus at 25°C than in TSB at the same level of salinity and inhibited the growth of both V. parahaemolyticus and V. vulnificus in live oysters at 25°C for 48 h. Furthermore, we tested the synergistic effect of d-Trp and salinity on the inhibition of total viable bacterial counts (TVC) at refrigeration temperature. d-Trp (40 mM) inhibited the growth of TVC in shucked oysters immersed in artificial seawater at 4°C. Therefore, these results revealed that d-Trp will serve as a novel and alternative food preservative to control Vibrio spp. in live oysters at ambient temperature and to extend the shelf-life of shucked oysters at refrigeration temperature.IMPORTANCE Oysters are the primary transmission vehicles for human Vibrio infections. Raw oyster consumption is frequently associated with gastroenteritis. The current postharvest methods, such as high-pressure processing, used to control Vibrio spp. in fresh oysters are still insufficient because of limited facilities, high cost, and potential adverse effects on production. We demonstrate that adding a small amount of d-tryptophan (d-Trp) inhibits the growths of Vibrio parahaemolyticus and Vibrio vulnificus in a high-salt environment at even ambient temperature. We further investigated the d-Trp treatment conditions and clarified the relationship between salt and d-Trp concentrations for optimal growth-inhibitory effect of Vibrio spp. The results will be useful for enhancing the effectiveness of d-Trp by increasing salinity levels. Furthermore, in a nutrientfree environment (artificial seawater), a stronger inhibitory effect could be observed at relatively lower salinity levels, indicating that d-Trp may be regarded as effective food preservation in terms of salinity reduction. Therefore, we suggest the use of exogenous d-Trp in a seawater environment as a novel and effective strategy not only for controlling Vibrio in live oysters at even ambient temperature but also for effectively retarding spoilage bacterial growth and extending the shelf life of shucked oysters at refrigeration temperature.


Assuntos
Antibacterianos/farmacologia , Ostreidae/microbiologia , Triptofano/farmacologia , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/crescimento & desenvolvimento , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/crescimento & desenvolvimento , Animais , Água do Mar/análise , Água do Mar/microbiologia , Cloreto de Sódio/metabolismo , Vibrio parahaemolyticus/metabolismo , Vibrio vulnificus/metabolismo
6.
Korean J Intern Med ; 33(6): 1070-1078, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29898575

RESUMO

Vibrio vulnificus is a gram-negative bacterium that can cause serious, potentially fatal infections. V. vulnificus causes three distinct syndromes: an overwhelming primary septicemia caused by consuming contaminated seafood, wound infections acquired when an open wound is exposed to contaminated warm seawater, and gastrointestinal tract-limited infections. Case-fatality rates are higher than 50% for primary septicemia, and death typically occurs within 72 hours of hospitalization. Risk factors for V. vulnificus infection include chronic liver disease, alcoholism, and hematological disorders. When V. vulnificus infection is suspected, appropriate antibiotic treatment and surgical interventions should be performed immediately. Third-generation cephalosporin with doxycycline, or quinolone with or without third-generation cephalosporin, may be potential treatment options for patients with V. vulnificus infection.


Assuntos
Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Saúde Pública , Alimentos Marinhos/microbiologia , Água do Mar/microbiologia , Sepse/microbiologia , Infecção da Ferida Cirúrgica/microbiologia , Vibrioses/microbiologia , Vibrio vulnificus/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Criança , Feminino , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/tratamento farmacológico , Doenças Transmitidas por Alimentos/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sepse/diagnóstico , Sepse/tratamento farmacológico , Sepse/mortalidade , Infecção da Ferida Cirúrgica/diagnóstico , Infecção da Ferida Cirúrgica/tratamento farmacológico , Infecção da Ferida Cirúrgica/mortalidade , Resultado do Tratamento , Vibrioses/diagnóstico , Vibrioses/tratamento farmacológico , Vibrioses/mortalidade , Vibrio vulnificus/efeitos dos fármacos , Adulto Jovem
7.
Artigo em Inglês | MEDLINE | ID: mdl-29868508

RESUMO

Antimicrobial resistance (AMR) in pathogens is the result of indiscriminate use of antibiotics and consequent metabolic/genetic modulation to evolve survival strategies and clonal-selection in AMR strains. As an alternative to antibiotic treatment, antivirulence strategies are being developed, not only to combat bacterial pathogenesis, but also to avoid emerging antibiotic resistance. Vibrio vulnificus is a foodborne pathogen that causes gastroenteritis, necrotizing wound infections, and sepsis with a high rate of mortality. Here, we developed an inhibitor-screening reporter platform to target HlyU, a master transcriptional regulator of virulence factors in V. vulnificus by assessing rtxA1 transcription under its control. The inhibitor-screening platform includes wild type and ΔhlyU mutant strains of V. vulnificus harboring the reporter construct P rtxA1::luxCDABE for desired luminescence signal detection and control background luminescence, respectively. Using the inhibitor-screening platform, we identified a small molecule, fursultiamine hydrochloride (FTH), that inhibits the transcription of the highly invasive repeat-in-toxin (rtxA1) and hemolysin (vvhA) along with other HlyU regulated virulence genes. FTH has no cytotoxic effects on either host cells or pathogen at the tested concentrations. FTH rescues host cells from the necrotic cell-death induced by RtxA1 and decreases the hemolytic activity under in vitro conditions. The most important point is that FTH treatment does not induce the antivirulence resistance. Current study validated the antivirulence strategy targeting the HlyU virulence transcription factor and toxin-network of V. vulnificus and demonstrated that FTH, exhibits a potential to inhibit the pathogenesis of deadly, opportunistic human pathogen, V. vulnificus without inducing AMR.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/efeitos dos fármacos , Fatores de Transcrição/efeitos dos fármacos , Vibrio vulnificus/efeitos dos fármacos , Proteínas de Bactérias/genética , Avaliação Pré-Clínica de Medicamentos , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Fursultiamina/farmacologia , Regulação Bacteriana da Expressão Gênica , Células HeLa , Proteínas Hemolisinas/efeitos dos fármacos , Humanos , Fatores de Transcrição/genética , Vibrio vulnificus/genética , Virulência/efeitos dos fármacos , Virulência/genética , Fatores de Virulência/genética
8.
Molecules ; 23(6)2018 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-29925801

RESUMO

The emergence of antimicrobial resistance and rapid acclimation allows Vibrio vulnificus to rapidly propagate in the host. This problematic pathological scenario can be circumvented by employing an antivirulence strategy, treating Vibrio infections without hindering the bacterial growth. We developed a genome-integrated orthogonal inhibitor screening platform in E. coli to identify antivirulence agents targeting a master virulence regulator of V. vulnificus. We identified 2',4'-dihydroxychalcone (DHC) from the natural compound library and verified that it decreases the expression of the major toxin network which is equivalent to the ∆hlyU deletion mutant. 2',4'-DHC also reduced the hemolytic activity of V. vulnificus which was tested as an example of virulence phenotype. The electrophoretic mobility shift assay confirmed that 2',4'-DHC specifically targeted HlyU and inhibited its binding to PrtxA1 promoter. Under in vivo conditions, a single dose of 2',4'-DHC protected ~50% wax-worm larvae from V. vulnificus infection at a non-toxic concentration to both V. vulnificus and wax-worm larvae. In the current study, we demonstrated that an orthogonal reporter system is suitable for the identification of antivirulence compounds with accuracy, and identified 2',4'-DHC as a potent antivirulence agent that specifically targets the HlyU virulence transcriptional regulator and significantly reduces the virulence and infection potential of V. vulnificus.


Assuntos
Antivirais/farmacologia , Proteínas de Bactérias/metabolismo , Chalconas/farmacologia , Fatores de Transcrição/metabolismo , Vibrio vulnificus/efeitos dos fármacos , Animais , Antivirais/química , Antivirais/toxicidade , Proteínas de Bactérias/genética , Produtos Biológicos/química , Sobrevivência Celular , Chalconas/química , Chalconas/toxicidade , Escherichia coli , Regulação Bacteriana da Expressão Gênica , Células HEK293 , Humanos , Larva , Mariposas/efeitos dos fármacos , Mariposas/microbiologia , Regiões Promotoras Genéticas , Bibliotecas de Moléculas Pequenas/química , Fatores de Transcrição/genética , Vibrio vulnificus/fisiologia , Virulência/efeitos dos fármacos , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Ativação Viral
9.
Int J Food Microbiol ; 279: 70-79, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-29738928

RESUMO

High salinity relay of Eastern oysters (Crassostrea virginica) was evaluated as a post-harvest processing (PHP) method for reducing Vibrio vulnificus. This approach relies on the exposure of oysters to natural high salinity waters and preserves a live product compared to previously approved PHPs. Although results of prior studies evaluating high salinity relay as a means to decrease V. vulnificus levels were promising, validation of this method as a PHP following approved guidelines is required. This study was designed to provide data for validation of this method following Food and Drug Administration (FDA) PHP validation guidelines. During each of 3 relay experiments, oysters cultured from 3 different Chesapeake Bay sites of contrasting salinities (10-21 psu) were relayed without acclimation to high salinity waters (31-33 psu) for up to 28 days. Densities of V. vulnificus and densities of total and pathogenic Vibrio parahaemolyticus (as tdh positive strains) were measured using an MPN-quantitative PCR approach. Overall, 9 lots of oysters were relayed with 6 exhibiting initial V. vulnificus >10,000/g. As recommended by the FDA PHP validation guidelines, these lots reached both the 3.52 log reduction and the <30 MPN/g densities requirements for V. vulnificus after 14 to 28 days of relay. Densities of total and pathogenic V. parahaemolyticus in relayed oysters were significantly lower than densities at the sites of origin suggesting an additional benefit associated with high salinity relay. While relay did not have a detrimental effect on oyster condition, oyster mortality levels ranged from 2 to 61% after 28 days of relay. Although the identification of the factors implicated in oyster mortality will require further examination, this study strongly supports the validation of high salinity relay as an effective PHP method to reduce levels of V. vulnificus in oysters to endpoint levels approved for human consumption.


Assuntos
Crassostrea/microbiologia , Contaminação de Alimentos/prevenção & controle , Doenças Transmitidas por Alimentos/prevenção & controle , Salinidade , Frutos do Mar/microbiologia , Cloreto de Sódio/farmacologia , Vibrio parahaemolyticus/crescimento & desenvolvimento , Vibrio vulnificus/crescimento & desenvolvimento , Animais , Baías , Contagem de Colônia Microbiana/métodos , Contaminação de Alimentos/análise , Inocuidade dos Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Alimentos Crus/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/isolamento & purificação
10.
Chem Biodivers ; 15(2)2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29168349

RESUMO

Two new pimarane diterpenes, libertellenone M (1) and libertellenone N (2), together with five known compounds were isolated from the culture extract of Eutypella sp. D-1 derived from high-latitude soil of the Arctic. The structures of these compounds were determined by spectroscopic data as well as experimental and calculated electronic circular dichroism (ECD) analysis. Antimicrobial and cytotoxic activities of the isolated compounds were evaluated. Compound 3 exhibited weak antibacterial activity against Escherichia coli, Bacillus subtilis, and Vibrio vulnificus, each with MIC values of 16 µg/mL. Compounds 2 and 3 showed moderate cytotoxic activity against K562 and MCF-7 cell lines with IC50 values of 7.67 and 9.57 µm, respectively.


Assuntos
/farmacologia , Antibacterianos/farmacologia , Antineoplásicos/farmacologia , Ascomicetos/química , /química , Antibacterianos/química , Antibacterianos/isolamento & purificação , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Regiões Árticas , Bacillus subtilis/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Escherichia coli/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Conformação Molecular , Extratos Vegetais/química , Relação Estrutura-Atividade , Vibrio vulnificus/efeitos dos fármacos
11.
Appl Environ Microbiol ; 84(3)2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29150510

RESUMO

Vibrio parahaemolyticus and Vibrio vulnificus are naturally occurring estuarine bacteria and are the leading causes of seafood-associated infections and mortality in the United States. Though multiple-antibiotic-resistant V. parahaemolyticus and V. vulnificus strains have been reported, resistance patterns in vibrios are not as well documented as those of other foodborne bacterial pathogens. Salinity relaying (SR) is a postharvest processing (PHP) treatment to reduce the abundances of these pathogens in shellfish harvested during the warmer months. The purpose of this study was to evaluate the antimicrobial susceptibility (AMS), pathogenicity, and genetic profiles of V. parahaemolyticus and V. vulnificus recovered from oysters during an oyster relay study. Isolates (V. parahaemolyticus [n = 296] and V. vulnificus [n = 94]) were recovered from oysters before and during the 21-day relaying study to detect virulence genes (tdh and trh) and genes correlated with virulence (vcgC) using multiplex quantitative PCR (qPCR). AMS to 20 different antibiotics was investigated using microbroth dilution, and pulsed-field gel electrophoresis (PFGE) was used to study the genetic profiles of the isolates. Twenty percent of V. vulnificus isolates were vcgC+, while 1 and 2% of V. parahaemolyticus were tdh+ and trh+, respectively. More than 77% of the V. vulnificus isolates and 30% of the V. parahaemolyticus isolates were resistant to at least one antimicrobial. Forty-eight percent of V. vulnificus and 8% of V. parahaemolyticus isolates were resistant to two or more antimicrobials. All isolates demonstrated a high genetic diversity, even among those isolated from the same site and having a similar AMS profile. No significant effects of the relaying process on AMS, virulence genes, or PFGE profiles of V. vulnificus and V. parahaemolyticus were observed.IMPORTANCE Analysis of the antibiotic resistance profiles of V. vulnificus and V. parahaemolyticus isolated from oysters during this study indicated that more than 48% of V. vulnificus isolates were resistant to two or more antimicrobials, including those recommended by the CDC for treating Vibrio infections. Also, the V. parahaemolyticus isolates showed high MICs for some of the Vibrio infection treatment antibiotics. Monitoring of AMS profiles of this bacterium is important to ensure optimal treatment of infections and improve food safety. Our study showed no significant differences in the AMS profiles of V. vulnificus (P = 0.26) and V. parahaemolyticus (P = 0.23) isolated from the oysters collected before versus after relaying. This suggests that the salinity of the relaying sites did not affect the AMS profiles of the Vibrio isolates, although it did reduce the numbers of these bacteria in oysters (S. Parveen et al., J Food Sci 82:484-491, 2017, https://doi.org/10.1111/1750-3841.13584).


Assuntos
Ostreidae/microbiologia , Frutos do Mar/microbiologia , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/patogenicidade , Vibrio vulnificus/genética , Vibrio vulnificus/patogenicidade , Animais , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana Múltipla/genética , Manipulação de Alimentos/métodos , Inocuidade dos Alimentos , Variação Genética , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Salinidade , Vibrioses/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio parahaemolyticus/isolamento & purificação , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/isolamento & purificação , Virulência/genética
12.
J Microbiol Immunol Infect ; 51(1): 76-81, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27260781

RESUMO

BACKGROUND/PURPOSE: The aim of this study is to investigate the role of tigecycline in Vibrio vulnificus infection. METHODS: Eight randomly selected clinical V. vulnificus isolates were studied to obtain the minimal inhibitory concentrations (MICs) of minocycline, cefotaxime, and tigecycline, and the time-kill curves of tigecycline alone or in combination with other drugs. A peritonitis mouse model was used for the evaluation of the therapeutic efficacy of tigecycline alone or cefotaxime in combination with minocycline or tigecycline. RESULTS: The MIC of minocycline, cefotaxime, and tigecycline for eight clinical V. vulnificus isolates was 0.06-0.12 µg/mL, 0.03-0.06 µg/mL, and 0.03-0.06 µg/mL, respectively. In time-killing studies, at the concentration of 1 × MIC, the inhibitory effect of tigecycline persisted for 24 hours in five of eight isolates. With 2 × MIC and trough level, the inhibitory effect was noted in all isolates for 24 hours. With the combination of minocycline plus cefotaxime and tigecycline plus cefotaxime at 1/2 × MIC, the bactericidal effect was noted in 25% and 62.5% of eight isolates and synergism in 50% and 75% of isolates. With a low (1.25 × 105 CFU/mL) inoculum, all infected mice survived with tigecycline alone, tigecycline plus cefotaxime, or minocycline plus cefotaxime on the 14th day. At the inoculum of 1.25 × 106 CFU, the survival rate was 33.3% on the 14th day in the tigecycline plus cefotaxime-treated group, but none of the mice treated by tigecycline alone or minocycline plus cefotaxime survived (33.3% vs. 0%, p = 0.01 by Fisher's exact test). CONCLUSION: Our in vitro combination and animal studies indicate that tigecycline could be an option for the treatment of invasive V. vulnificus infections.


Assuntos
Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Minociclina/análogos & derivados , Vibrioses/tratamento farmacológico , Vibrio vulnificus/efeitos dos fármacos , Animais , Cefotaxima/farmacologia , Contagem de Colônia Microbiana , Modelos Animais de Doenças , Combinação de Medicamentos , Sinergismo Farmacológico , Quimioterapia Combinada , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Minociclina/farmacologia , Minociclina/uso terapêutico , Peritonite/tratamento farmacológico , Peritonite/microbiologia , Taxa de Sobrevida , Taiwan , Tigeciclina , Fatores de Tempo , Vibrio vulnificus/isolamento & purificação
13.
Artigo em Inglês | MEDLINE | ID: mdl-28971862

RESUMO

Foodborne Vibrio vulnificus infections are associated with higher rates of sepsis and mortality than wound infections; however, antibiotic efficacy studies have not been performed in foodborne infection models. The efficacies of ceftriaxone, cefepime, doxycycline, ciprofloxacin, and combination therapy were assessed in V. vulnificus intestinal infection in mice in order to model foodborne infections. In accordance with prior studies of cefotaxime, cefepime was synergistic with doxycycline and ciprofloxacin in vitro; combination therapy significantly decreased bacterial growth, by ≥2 log10 units, from that with antibiotic monotherapy (P < 0.01). In vivo, survival rates in the ceftriaxone (50%), doxycycline (79%), and ciprofloxacin (80%) groups were significantly higher than those in the control group (0%) (P < 0.0001). Survival was significantly higher with ceftriaxone-doxycycline (91%) or ceftriaxone-ciprofloxacin (100%) therapy than with ceftriaxone (50%) (P ≤ 0.05). Survival with cefepime-doxycycline (96%) or cefepime-ciprofloxacin (90%) therapy was significantly higher than that with cefepime alone (20%) (P < 0.001). There was no difference in survival between the combination therapy groups. Thus, we conclude that combination therapy was the most effective treatment for foodborne V. vulnificus septicemia. In a septic patient with a recent ingestion of raw seafood, cefepime in combination with doxycycline or ciprofloxacin should be initiated for coverage of resistant Gram-negative organisms and V. vulnificus pending a microbiological diagnosis. Once a diagnosis of foodborne V. vulnificus septicemia is established, treatment can safely transition to ceftriaxone in combination with doxycycline or ciprofloxacin.


Assuntos
Antibacterianos/uso terapêutico , Ceftriaxona/uso terapêutico , Cefalosporinas/uso terapêutico , Ciprofloxacino/uso terapêutico , Doxiciclina/uso terapêutico , Doenças Transmitidas por Alimentos/tratamento farmacológico , Sepse/tratamento farmacológico , Vibrioses/tratamento farmacológico , Vibrio vulnificus/efeitos dos fármacos , Animais , Cefepima , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Camundongos , Alimentos Marinhos/microbiologia , Sepse/microbiologia , Vibrioses/microbiologia , Vibrioses/mortalidade
14.
Sci Rep ; 7(1): 13572, 2017 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-29051620

RESUMO

Vibrio vulnificus causes fatal infections in humans, and antibiotics are commonly used in treatment regimens against V. vulnificus infection. However, the therapeutic effects of antibiotics are limited by multidrug resistance. In this study, we demonstrated that an antimicrobial peptide (AMP), HPA3PHis, loaded onto a gold nanoparticle-DNA aptamer (AuNP-Apt) conjugate (AuNP-Apt-HPA3PHis) is an effective therapeutic tool against V. vulnificus infection in vivo in mice. HPA3PHis induced bacterial cell death through the disruption of membrane integrity of V. vulnificus. The introduction of AuNP-Apt-HPA3PHis into V. vulnificus-infected HeLa cells dramatically reduced intracellular V. vulnificus by 90%, leading to an increase in the viability of the infected cells. Moreover, when V. vulnificus-infected mice were intravenously injected with AuNP-Apt-HPA3PHis, a complete inhibition of V. vulnificus colonization was observed in the mouse organs, leading to a 100% survival rate among the treated mice, whereas all the control mice died within 40 hours of being infected. Therefore, this study demonstrated the potential of an AMP delivered by AuNP-Apt as an effective and rapid treatment option against infection caused by a major pathogen in humans and aquatic animals.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Aptâmeros de Nucleotídeos/química , Sistemas de Liberação de Medicamentos/métodos , Vibrio vulnificus/efeitos dos fármacos , Animais , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Feminino , Ouro , Células HeLa/virologia , Humanos , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Camundongos Endogâmicos ICR , Testes de Sensibilidade Microbiana , Fragmentos de Peptídeos/química , Proteínas Ribossômicas/química , Vibrioses/tratamento farmacológico , Vibrioses/mortalidade , Vibrio vulnificus/patogenicidade
15.
PLoS One ; 12(1): e0169678, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28085905

RESUMO

To address the growing concern over antibiotic-resistant microbial infections in aquatic animals, we tested several promising alternative agents that have emerged as new drug candidates. Specifically, the tilapia piscidins are a group of peptides that possess antimicrobial, wound-healing, and antitumor functions. In this study, we focused on tilapia piscidin 3 (TP3) and TP4, which are peptides derived from Oreochromis niloticus, and investigated their inhibition of acute bacterial infections by infecting hybrid tilapia (Oreochromis spp.) with Vibrio vulnificus and evaluating the protective effects of pre-treating, co-treating, and post-treating fish with TP3 and TP4. In vivo experiments showed that co-treatment with V. vulnificus and TP3 (20 µg/fish) or TP4 (20 µg/fish) achieved 95.3% and 88.9% survival rates, respectively, after seven days. When we co-injected TP3 or TP4 and V. vulnificus into tilapia and then re-challenged the fish with V. vulnificus after 28 days, the tilapia exhibited survival rates of 35.6% and 42.2%, respectively. Pre-treatment with TP3 (30 µg/fish) or TP4 (20 µg/fish) for 30 minutes prior to V. vulnificus infection resulted in high survival rates of 28.9% and 37.8%, respectively, while post-treatment with TP3 (20 µg/fish or 30 µg/fish) or TP4 (20 µg/fish) 30 minutes after V. vulnificus infection yielded high survival rates of 33.3% and 48.9%. In summary, pre-treating, co-treating, and post-treating fish with TP3 or TP4 all effectively decreased the number of V. vulnificus bacteria and promoted significantly lower mortality rates in tilapia. The minimum inhibitory concentrations (MICs) of TP3 and TP4 that were effective for treating fish infected with V. vulnificus were 7.8 and 62.5 µg/ml, respectively, whereas the MICs of kanamycin and ampicillin were 31.2 and 3.91 µg/ml. The antimicrobial activity of these peptides was confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), both of which showed that V. vulnificus disrupted the outer membranes of cells, resulting in the loss of cell shape and integrity. We examined whether TP3 and TP4 increased the membrane permeability of V. vulnificus by measuring the fluorescence resulting from the uptake of 1-N-phenyl-naphthylamine (NPN). Treating fish with TP3 and TP4 under different pH and temperature conditions did not significantly increase MIC values, suggesting that temperature and the acid-base environment do not affect AMP function. In addition, the qPCR results showed that TP3 and TP4 influence the expression of immune-responsive genes, including interleukin (IL)-1ß, IL-6, and IL-8. In this study, we demonstrate that TP3 and TP4 show potential for development as drugs to combat fish bacterial infections in aquaculture.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Ciclídeos/imunologia , Doenças dos Peixes/imunologia , Imunidade Celular/efeitos dos fármacos , Vibrioses/veterinária , Vibrio vulnificus/imunologia , Animais , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/microbiologia , Testes de Sensibilidade Microbiana , Vibrioses/tratamento farmacológico , Vibrioses/imunologia , Vibrioses/microbiologia , Vibrio vulnificus/efeitos dos fármacos
16.
PLoS One ; 11(12): e0167699, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27936080

RESUMO

Vibrio vulnificus is a causative agent of fatal septicemia and necrotic wound infection and the pathogen infection became an important public health problem in many counties. Vibrio vulnificus causes RtxA1 toxin-induced acute cell death. We tried to identify natural products that inhibit the acute cytotoxicity of V. vulnificus using a lactate hydrogenase assay. A polyphenol pyrogallol protected HeLa cells from V. vulnificus-induced cytotoxicity. Pyrogallol also decreased the growth of V. vulnificus; this inhibitory effect was more significant during log phase than stationary phase. To further elucidate the inhibitory mechanism, pyrogallol-induced toxicity was compared between a V. vulnificus catalase-peroxidase mutant (katG-) and the isogenic wild-type MO6-24/O strains. No growth was observed for the katG- mutant in the presence of pyrogallol (50 µg/mL) even after 24 h, whereas the wild-type strain demonstrated growth recovery following a prolonged lag phase. Pyrogallol-mediated growth inhibition of the katG- mutant strain was partially rescued by exogenous catalase treatment. These results indicate that the mechanism by which pyrogallol inhibits the growth and cytotoxicity of V. vulnificus likely involves polyphenol-induced prooxidant damage. Taken together, these results suggest that pyrogallol has potential for development as a new paradigm drug to treat infectious diseases.


Assuntos
Antibacterianos/farmacologia , Catalase/genética , Pirogalol/farmacologia , Vibrioses/tratamento farmacológico , Vibrioses/enzimologia , Vibrio vulnificus/efeitos dos fármacos , Antioxidantes/farmacologia , Toxinas Bacterianas/genética , Deleção de Genes , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Células HeLa , Humanos , Vibrioses/genética , Vibrio vulnificus/genética , Vibrio vulnificus/crescimento & desenvolvimento
17.
FEBS Lett ; 590(24): 4564-4572, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27859050

RESUMO

The human pathogen Vibrio vulnificus undergoes phase variation among colonial morphotypes, including a virulent opaque form which produces capsular polysaccharide (CPS) and a translucent phenotype that produces little or no CPS and is attenuated. Here, we found that a V. vulnificus mutant defective for RfaH antitermination control showed a diminished capacity to undergo phase variation and displayed significantly reduced distal gene expression within the Group I CPS operon. Moreover, the rfaH mutant produced negligible CPS and was highly sensitive to killing by normal human serum, results which indicate that RfaH is likely essential for virulence in this bacterium.


Assuntos
Cápsulas Bacterianas/metabolismo , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Fatores de Alongamento de Peptídeos/genética , Polissacarídeos Bacterianos/biossíntese , Vibrio vulnificus/metabolismo , Fatores de Virulência/genética , Cápsulas Bacterianas/efeitos dos fármacos , Cápsulas Bacterianas/genética , Proteínas de Bactérias/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Imunoglobulinas/sangue , Imunoglobulinas/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Mutação , Óperon , Fatores de Alongamento de Peptídeos/deficiência , Fenótipo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transativadores/deficiência , Transativadores/genética , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/genética , Vibrio vulnificus/patogenicidade , Fatores de Virulência/deficiência
18.
Int J Food Microbiol ; 236: 123-9, 2016 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-27485973

RESUMO

Biofilms are recalcitrant and raise safety problems in the food industry. In this study, the role of CabA, an extracellular matrix protein, in the resistance of the biofilms of Vibrio vulnificus, a foodborne pathogen, to decontamination strategies was investigated. Biofilms of the cabA mutant revealed reduced resistance to detachment by vibration and disinfection by sodium hypochlorite compared to the biofilms of the parental wild type in vitro. The reduced resistance of the cabA mutant biofilms was complemented by introducing a recombinant cabA, indicating that the reduced resistance of the cabA mutant biofilms is caused by the inactivation of cabA. The expression of cabA was induced in cells bound to oyster, the primary vehicle of the pathogen. The cabA mutant biofilms on oyster are defective in biomass and resistance to detachment and disinfection. The bacterial cells in the wild-type biofilms are clustered by filaments which are not apparent in the cabA mutant biofilms. The combined results indicated that CabA contributes to the structural integrity of V. vulnificus biofilms possibly by forming filaments in the matrix and thus rendering the biofilms robust, suggesting that CabA could be a target to control V. vulnificus biofilms on oyster.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Desinfecção/métodos , Ostreidae/microbiologia , Frutos do Mar/microbiologia , Animais , Proteínas de Bactérias/genética , Descontaminação , Desinfecção/instrumentação , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Vibrio vulnificus/efeitos dos fármacos , Vibrio vulnificus/genética , Vibrio vulnificus/fisiologia
19.
Mol Med Rep ; 14(3): 2691-6, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27431807

RESUMO

Vibrio vulnificus is known to induce severely fulminant and fatal septicemia in susceptible hosts. In the present study, the antimicrobial activity of natural marine product-derived compounds against V. vulnificus, were investigated in vitro and in vivo. Twelve pure compounds were isolated from natural marine products and their inhibitory effects on V. vulnificus-induced cytotoxicity were determined in INT­407 cells. Among the 12 pure compounds tested, treatment with psammaplin A significantly suppressed V. vulnificus­induced cytotoxicity in INT­407 cells. Notably, treatment with psammaplin A (5-50 µg) had improved survival rates compared with that in the untreated mice, when the mice were infected with V. vulnificus intraperitoneally. In addition, the bacterial load of V. vulnificus in several tissues (spleen, liver and small intestine) was significantly lower in psammaplin A­treated mice than in untreated mice. Furthermore, psammaplin A treatment significantly suppressed the growth of V. vulnificus. Taken together, these results indicate that psammaplin A may be a potential agent for the prevention and treatment of V. vulnificus infections.


Assuntos
Antibacterianos/farmacologia , Organismos Aquáticos/química , Produtos Biológicos/farmacologia , Dissulfetos/farmacologia , Tirosina/análogos & derivados , Vibrio vulnificus/efeitos dos fármacos , Animais , Linhagem Celular , Modelos Animais de Doenças , Células Epiteliais , Feminino , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Tirosina/farmacologia , Vibrioses/tratamento farmacológico , Vibrioses/microbiologia , Vibrioses/mortalidade , Vibrioses/patologia
20.
Food Microbiol ; 57: 128-34, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27052711

RESUMO

Vibrio parahaemolyticus and Vibrio vulnificus are the leading causes of seafood associated infections and mortality in the United States. The main syndromes caused by these pathogens are gastroenteritis, wound infections, and septicemia. This article reviewed the antibiotic resistance profile of V. parahaemolyticus and V. vulnificus in the United States and other countries including Italy, Brazil, Philippines, Malaysia, Thailand, China, India, Iran, South Africa and Australia. The awareness of antimicrobial resistance of these two pathogens is not as well documented as other foodborne bacterial pathogens. Vibrio spp. are usually susceptible to most antimicrobials of veterinary and human significance. However, many studies reported that V. vulnificus and V. parahaemolyticus showed multiple-antibiotic resistance due to misuse of antibiotics to control infections in aquaculture production. In addition, both environmental and clinical isolates showed similar antibiotic resistance profiles. Most frequently observed antibiotic resistance profiles involved ampicillin, penicillin and tetracycline regardless of the countries. The presence of multiple-antibiotic resistant bacteria in seafood and aquatic environments is a major concern in fish and shellfish farming and human health.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Vibrioses/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Vibrio vulnificus/efeitos dos fármacos , Animais , Contaminação de Alimentos/análise , Humanos , Alimentos Marinhos/microbiologia , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/metabolismo , Vibrio vulnificus/genética , Vibrio vulnificus/metabolismo
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