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1.
J Surfactants Deterg ; 26(3): 387-399, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37470058

RESUMO

The objective of this study is to demonstrate that melittin, a well-studied antimicrobial peptide (AMP), can be solubilized in an active form in bicontinuous microemulsions (BMEs) that employ biocompatible oils. The systems investigated consisted of Winsor-III and -IV BME phases composed of Water/Aerosol-OT (AOT)/Polysorbate 85/isopropyl myristate and a Winsor-IV BME employing Polysorbate 80 and limonene. We found that melittin resided in an α-helix-rich configuration and was in an apolar environment for the AOT/Polysorbate 85 Winsor-III system, suggesting that melittin interacted with the surfactant monolayer and was in an active conformation. An apolar environment was also detected for melittin in the two Winsor-IV systems, but to a lesser extent than the Winsor-III system. Small-angle X-ray scattering analysis indicated that melittin at a concentration of 1.0 g/Laq in the aqueous subphase of the Winsor-IV systems led to the greatest impact on the BME structure (e.g., decrease of quasi-periodic repeat distance and correlation length and induction of interfacial fluidity). The antimicrobial activity of the Polysorbate 80 Winsor-IV system was evaluated against several bacteria prominent in chronic wounds and surgical site infections (SSIs). Melittin-free BMEs inhibited the growth of all tested bacteria due to its oil, limonene, while the inclusion of 1.0 g/Laq of melittin in the BMEs enhanced the activity against several bacteria. A further increase of melittin concentration in the BMEs had no further enhancement. These results demonstrate the potential utility of BMEs as a delivery platform for AMPs and other hydrophilic and lipophilic drugs to inhibit antibiotic-resistant microorganisms in chronic wounds and SSIs.

2.
Foodborne Pathog Dis ; 19(6): 408-416, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35451874

RESUMO

Antimicrobials have been widely used in dairy farms to prevent and control dairy cattle diseases since 1960s. This led to the emergence of antimicrobial resistant bacteria (ARB) that, along with their antimicrobial resistance genes (ARGs), can spread from dairy farms to humans. Therefore, regular antimicrobial resistance (AMR) monitoring is important to implement proper mitigation measures. The objective of this study was to determine the prevalence of AMR and extended-spectrum beta-lactamases (ESBLs)-producing Escherichia coli in dairy cattle. A cross-sectional study was conducted in four dairy cattle farms (A-D) in East Tennessee. A total of 80 samples consisting of 20 samples each of bulk tank milk, feces, dairy cattle manure-amended soil, and prairie soil adjacent to the farms were collected and cultured for the isolation of E. coli. Tetracycline (TETr)-, third-generation cephalosporin (TGCr)- and nalidixic acid (NALr)-resistant E. coli (n = 88) were isolated and identified on agar media supplemented with TET, cefotaxime, and NAL, respectively. TGCr E. coli were tested for ESBLs and other coselected ARGs. TETr (74%, n = 88) was the most common, followed by TGCr (20%) and NALr (8%). Farms had significant (p < 0.001) differences: the highest prevalence of TGCr (55%) and TETr (100%) were observed in farm D, while all NALr isolates were from farm C. Over 83% of TGCr isolates (n = 18) harbored ESBL gene blaCTX-M. Majority (78%) of the E. coli isolates were multidrug-resistant (MDR), being positive for beta-lactams (blaCTX-M), TETs tet(A), tet(B), tet(M)), sulfonamides (sul2), aminoglycosides (strA), and phenicols (floR). This study indicated the widespread occurrence of MDR ESBLs-E. coli in dairy cattle farms. AMR surveillance of more dairy farms and identification of farm-level risk factors are important to mitigate the occurrence and spread of ARB of significant public health importance, such as ESBLs-E. coli.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Infecções por Escherichia coli , Escherichia coli , Animais , Antibacterianos/farmacologia , Bovinos/microbiologia , Estudos Transversais , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Fazendas , Prevalência , Solo , Tennessee/epidemiologia , beta-Lactamases/genética
3.
Food Microbiol ; 98: 103784, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33875212

RESUMO

Aichi virus (AiV) is an enteric virus that affects humans and is prevalent in sewage waters. Effective strategies to control its spread need to be explored. This study evaluated grape seed extract (GSE) for: a) antiviral potential towards AiV infectivity at 37 °C and room temperature (RT); b) antiviral behavior in model foods (apple juice (AJ) and 2% fat milk) and also simulated gastric environments; and c) potential application as a wash solution on stainless steel surfaces. GSE at 0.5 mg/mL decreased AiV suspensions containing ~4.75 log PFU/mL to titer levels that were not detected after 30 s at both 37 °C and RT. Infectious AiV titers were not detected after 5 min treatment with 1 mg/mL GSE at 37 °C in AJ. GSE at 2 mg/mL and 4 mg/mL in 2% fat milk decreased AiV after 24 h by 1.18 and 1.57 log PFU/mL (4.75 log PFU/mL to 2.86 and 3.25 log PFU/mL), respectively. As a surface wash, GSE at 1 mg/mL after 30 s decreased AiV to undetectable levels under clean conditions. With organic load (mimicking unclean conditions), 2 and 4 mg/mL GSE reduced AiV after 5 min by 1.13 and 1.71 log PFU/mL, respectively. Overall, GSE seems to be a promising antiviral agent against AiV at low concentrations and short contact times.


Assuntos
Antivirais/farmacologia , Extrato de Sementes de Uva/farmacologia , Kobuvirus/efeitos dos fármacos , Animais , Bovinos , Contaminação de Equipamentos/prevenção & controle , Contaminação de Equipamentos/estatística & dados numéricos , Contaminação de Alimentos/prevenção & controle , Contaminação de Alimentos/estatística & dados numéricos , Indústria de Processamento de Alimentos/instrumentação , Sucos de Frutas e Vegetais/virologia , Kobuvirus/crescimento & desenvolvimento , Leite/virologia , Modelos Biológicos , Aço Inoxidável/análise
4.
Immunol Invest ; 49(7): 711-725, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32456495

RESUMO

BACKGROUND: Exosomes are extracellular vesicles involved in intercellular communication. The objectives were to characterize bovine milk exosomes (BME) and determine its effect on RAW 264.7 macrophages. METHODS: BME were isolated using differential centrifugation and characterized by particle size and the presence of exosomal markers Alix, TSG101, and CD81. The effect of in vitro digestion and different pH on the stability of BME was investigated. The biological activity of BME in RAW 264.7 macrophages was conducted by assessing proliferation and cell cycle. Moreover, the protective effect of exosomes on cisplatin-induced cytotoxicity was evaluated. RESULTS: BME have an average particle size of 106.8 ± 3.4 nm and expressed Alix, TSG101, and CD81. TSG101 was detected after digestion and exposure to different pH values. Cell-cycle analysis showed that BME reduced the percentage of apoptotic cells while arresting the cells in G2/M phase accompanied by differential expression of proliferation markers p53, p21, cyclin D1, and ß-catenin. Exosomes protected macrophages against cisplatin-induced cytotoxicity. CONCLUSION: Our results showed for the first time the effect of BME on the proliferation of RAW 264.7 macrophages and its protective effect against chemotherapeutic drug-induced cytotoxicity. Potential effect of BME on immune system must be studied.


Assuntos
Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/imunologia , Cisplatino/farmacologia , Exossomos/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Leite , Animais , Biomarcadores , Bovinos , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Fracionamento Químico , Concentração de Íons de Hidrogênio , Camundongos , Leite/imunologia , Leite/metabolismo , Células RAW 264.7
5.
Food Microbiol ; 90: 103461, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32336357

RESUMO

Human noroviruses (HNoV) and hepatitis A virus (HAV) are predominantly linked to foodborne outbreaks worldwide. As cell-culture systems to propagate HNoV in laboratories are not easily available, Tulane virus (TV) is used as a cultivable HNoV surrogate to determine inactivation. Heat-sensitization of HAV and TV by "generally recognized as safe'' (GRAS) substances can potentially reduce their time-temperature inactivation parameters during processing to ensure food safety. Curcumin, gingerol (from ginger), and grape seed extract (GSE) reportedly have anti-inflammatory, immune-modulating and antiviral properties. The objective of this study was to determine and compare the D-values and z-values of HAV and TV at 52-68 °C with or without curcumin (0.015 mg/ml), gingerol (0.1 mg/ml), or GSE (1 mg/ml) in 2-ml glass vials. HAV at ~7 log PFU/ml and TV at ~6 log PFU/ml were diluted in phosphate buffered saline (PBS) and added to two sets of six 2-mL sterile glass vials. One set served as the control and the second set had the three extracts individually added for thermal treatments in a circulating water bath for 0-10 min. The D-values for TV in PBS ranged from 4.55 ± 0.28 to 1.08 ± 0.16 min, and for HAV in PBS ranged from to 9.21 ± 0.24 to 0.67 ± 0.19 min at 52-68 °C. Decreased D-values (52-58 °C) for TV with curcumin ranging from 4.32 ± 0.25 to 0.62 ± 0.17 min, gingerol from 4.09 ± 0.18 to 0.72 ± 0.09 min and GSE from 3.82 ± 0.18 to 0.80 ± 0.07 min, with similar trends for HAV were observed. The linear model showed significant differences (p < 0.05) between the D-values of HAV and TV with and without plant extracts for most tested temperatures. This suggests that GRAS substances can potentially lower temperature and time regimens needed to inactivate HAV and TV.


Assuntos
Antivirais/farmacologia , Microbiologia de Alimentos/métodos , Vírus da Hepatite A/efeitos dos fármacos , Temperatura Alta , Norovirus/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos , Catecóis/farmacologia , Curcumina/farmacologia , Álcoois Graxos/farmacologia , Extrato de Sementes de Uva/farmacologia , Vírus da Hepatite A/fisiologia , Norovirus/fisiologia
6.
Food Microbiol ; 82: 202-208, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31027775

RESUMO

Blueberry polyphenols are known for their high antioxidant and antimicrobial potential. Aichi virus (AiV) is an emerging human enteric virus that causes gastroenteritis outbreaks worldwide. This study aimed to (1) determine the time- and dose-dependent effects of blueberry proanthocyanidins (B-PAC) against AiV over 24 h at 37 °C; (2) gain insights on their mode of action using pre- and post-treatment of host cells and Transmission Electron Microscopy; and (3) determine their anti-AiV effects in model foods and under simulated gastric conditions. AiV at ∼5 log PFU/ml was incubated with equal volumes of commercial blueberry juice (BJ, pH 2.8), neutralized BJ (pH 7.0), B-PAC (2, 4, and 10 mg/ml) prepared either in 10% ethanol, apple juice (AJ), 2% milk, simulated gastric fluid (SGF, pH 1.5) or simulated intestinal fluid (SIF, pH 7.5), and controls (malic acid (pH 3.0), phosphate buffered saline (pH 7.2), apple juice (pH 3.6) and 2% milk) over 24 h at 37 °C, followed by standard plaque assays. Each experiment was replicated thrice and data were statistically analyzed. Differences in AiV titers with 1 mg/ml B-PAC were 2.13 ±â€¯0.06 log PFU/ml lower after 24 h and ≥3 log PFU/ml (undetectable levels) lower with 2 and 5 mg/ml B-PAC compared to AiV titers in PBS after 24 h and 3 h, respectively. BJ at 37 °C resulted in titer differences (lower titers compared to PBS) of 0.17 ±â€¯0.06, 1.27 ±â€¯0.01, and 1.73 ±â€¯0.23 log PFU/ml after 1, 3, and 6 h and ≥3 log PFU/ml after 24 h. Pre- and post-treatment of host cells with 0.5 mg/ml B-PAC caused titer decreases of 0.62 ±â€¯0.33 and 0.30 ±â€¯0.06 log PFU/ml, respectively suggesting a moderate effect on viral-host cell binding. B-PAC at 2 mg/ml in AJ caused titer differences of ≥3 log PFU/ml after 0.5 h, while differences of 0.84 ±â€¯0.03 log PFU/ml with 5 mg/ml B-PAC in milk, and ≥3 log PFU/ml with B-PAC at 5 mg/ml in SIF after 30 min were obtained. This study shows the ability of BJ and B-PAC to decrease AiV titers to potentially prevent AiV-related illness and outbreaks.


Assuntos
Antivirais/farmacologia , Mirtilos Azuis (Planta)/química , Microbiologia de Alimentos , Kobuvirus/efeitos dos fármacos , Proantocianidinas/farmacologia , Animais , Chlorocebus aethiops , Doenças Transmitidas por Alimentos/prevenção & controle , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/virologia , Gastroenterite/prevenção & controle , Leite/virologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Temperatura , Células Vero , Ligação Viral/efeitos dos fármacos , Replicação Viral/efeitos dos fármacos
7.
Food Microbiol ; 76: 346-353, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30166160

RESUMO

Plant polyphenols have shown antiviral activity against several human pathogens, but their physicochemical interactions are not well-understood. The objectives of this study were to compare the antiviral activity between monomeric catechin and dimeric procyanidin B2 (PB2) using cultivable human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)) and to understand their potential antiviral mechanism using virus-like particles (VLPs) and the P domain of human norovirus GII (HNoV GII.4). Surrogate viruses at 5 log PFU/mL were treated with 0.5-5 mg/mL monomeric catechin monohydrate, PB2 or phosphate buffered saline (PBS, pH 7.2; control) at 37 °C over 24 h. Infectivity was determined using plaque assays and data from triplicate experiments were statistically analyzed. PB2 at 0.5 mg/mL and 1 mg/mL reduced FCV-F9 to undetectable levels after 3 h and MNV-1 by 0.21 and 1.23 log PFU after 24 h, respectively. Monomeric catechins at 1 mg/mL reduced FCV-F9 to undetectable levels after 6 h and MNV-1 titers to undetectable levels after 24 h. In addition, PB2 was shown to directly bind the P domain, the main capsid structure of HNoVs in the ratio of 1:1 through spontaneous interactions. Electrostatic interactions played a dominant role between PB2 and the P domain. PB2 significantly altered tertiary but not secondary structures of VLPs. Transmission electron microscopy demonstrated that PB2 aggregated VLPs, further indicating interactions between them. These findings indicate that PB2 causes structural changes of the P domain of VLPs, mainly through direct interaction leading to HNoV inactivation.


Assuntos
Antivirais/farmacologia , Biflavonoides/farmacologia , Calicivirus Felino/efeitos dos fármacos , Catequina/farmacologia , Proantocianidinas/farmacologia , Inativação de Vírus/efeitos dos fármacos , Animais , Antivirais/metabolismo , Biflavonoides/metabolismo , Calicivirus Felino/metabolismo , Catequina/metabolismo , Gatos , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Norovirus/efeitos dos fármacos , Proantocianidinas/metabolismo , Ensaio de Placa Viral , Ligação Viral
8.
Foodborne Pathog Dis ; 15(7): 449-458, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29394099

RESUMO

Staphylococcus aureus is a frequent and major contagious mastitis bacterial pathogen. The antibiotic treatment cure rates vary considerably from 4% to 92%. Staphylococcus aureus readily becomes resistant to antibiotics, resulting in persistent noncurable intramammary infection that usually results in culling of infected animals. Because of its notorious ability to acquire resistance to the commonly used as well as last resort antimicrobials such as methicillin and vancomycin and the development of multidrug-resistant strains, antimicrobial resistance (AMR) in S. aureus is of paramount importance in human medicine. The objective of this study was to evaluate the prevalence of AMR and genetic diversity of S. aureus isolates from milk of dairy cattle. Staphylococcus aureus isolates (n = 239) from 33 dairy farms in Tennessee were tested against 10 antimicrobials by broth microdilution method using the Sensititer system. Genetic diversity of resistant isolates was evaluated by pulsed-field gel electrophoresis (PFGE). Overall, AMR of the S. aureus isolates varied from as low as 1.3% for ceftiofur to as high as 25% for sulfadimethoxine. Out of 239 S. aureus isolates, 82 (34.3%) of them were resistant to at least 1 of the 10 antimicrobials. The AMR isolates belonged to two major PFGE types, indicating the presence of dominant clonal patterns among the resistant isolates. In general, there was a variation of prevalence of AMR within and among farms over time, with an increasing trend in tetracycline resistance. Judicious use of antimicrobials in dairy cattle farms can reduce the development of antimicrobial-resistant S. aureus.


Assuntos
Anti-Infecciosos/farmacologia , Farmacorresistência Bacteriana , Variação Genética , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Animais , Bovinos , Indústria de Laticínios , Eletroforese em Gel de Campo Pulsado/veterinária , Feminino , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/isolamento & purificação , Tennessee/epidemiologia
9.
Food Microbiol ; 62: 251-255, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27889156

RESUMO

Viral foodborne illness continues to be a health-concern globally, with numerous fruit and juice outbreaks of Hepatitis A virus (HAV) reported worldwide. Aichi virus (AiV) is an emerging pathogen with limited epidemiological data. Both, HAV and AiV are resistant to low pH and can survive under adverse environmental conditions leading to transmission ease. The objective of this study was to evaluate the survival of HAV and AiV in commercially-available cranberry-based juices (Cranberry juice cocktail, CJ and a 100% juice with cranberry, MJ) over 21 days at refrigeration (4 °C). Equal volumes of juice was mixed with each virus individually (final titer of 6 log PFU/mL) and stored at refrigeration over 21 days. At each time interval, the inoculated juices were serially diluted in cell culture media and infectious virus survival was determined by standard plaque assays. Each experiment was carried out in duplicate and replicated thrice. Reductions of 0.72 ± 0.06 (after day 1) to 2.3 ± 0.18 log PFU/mL (after day 21) and 0.63 ± 0.02 (after day 1) to 1.84 ± 0.14 log PFU/mL (after day 21) were obtained for AiV with MJ and CJ, respectively. Reductions ranging from 0.67 ± 0.03 (after day 1) to 1.09 ± 0.1 log PFU/mL (after day 21) and 0.93 ± 0.27 (after day1) to 1.49 ± 0.18 log PFU/mL (after day 21) were obtained for HAV at refrigeration in MJ and CJ, respectively. HAV showed greater survival than AiV in these juices over refrigerated storage. These results provide survival data of HAV and AiV in cranberry-based juices that can be used in risk-modeling and risk assessment studies.


Assuntos
Sucos de Frutas e Vegetais/microbiologia , Vírus da Hepatite A/isolamento & purificação , Kobuvirus/isolamento & purificação , Viabilidade Microbiana , Refrigeração , Vaccinium macrocarpon , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Humanos
10.
Food Microbiol ; 63: 263-267, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28040178

RESUMO

Blueberry proanthocyanidins (B-PAC) are known to decrease titers of human norovirus surrogates in vitro. The application of B-PAC as therapeutic or preventive options against foodborne viral illness needs to be determined using model foods and simulated gastric conditions in vitro. The objective of this study was to evaluate the antiviral effect of B-PAC in model foods (apple juice (AJ) and 2% reduced fat milk) and simulated gastrointestinal fluids against cultivable human norovirus surrogates (feline calicivirus; FCV-F9 and murine norovirus; MNV-1) over 24 h at 37 °C. Equal amounts of each virus (5 log PFU/ml) was mixed with B-PAC (1, 2 and 5 mg/ml) prepared either in AJ, or 2% milk, or simulated gastric fluids and incubated over 24 h at 37 °C. Controls included phosphate buffered saline, malic acid (pH 7.2), AJ, 2% milk or simulated gastric and intestinal fluids incubated with virus over 24 h at 37 °C. The tested viruses were reduced to undetectable levels within 15 min with B-PAC (1, 2 and 5 mg/ml) in AJ (pH 3.6). However, antiviral activity of B-PAC was reduced in milk. FCV-F9 was reduced by 0.4 and 1.09 log PFU/ml with 2 and 5 mg/ml B-PAC in milk, respectively and MNV-1 titers were reduced by 0.81 log PFU/ml with 5 mg/ml B-PAC in milk after 24 h. B-PAC at 5 mg/ml in simulated intestinal fluid reduced titers of the tested viruses to undetectable levels within 30 min. Overall, these results show the potential of B-PAC as preventive and therapeutic options for foodborne viral illnesses.


Assuntos
Mirtilos Azuis (Planta)/química , Calicivirus Felino/crescimento & desenvolvimento , Norovirus/crescimento & desenvolvimento , Proantocianidinas/farmacologia , Animais , Antivirais/farmacologia , Calicivirus Felino/efeitos dos fármacos , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/prevenção & controle , Sucos de Frutas e Vegetais/análise , Sucos de Frutas e Vegetais/virologia , Ácido Gástrico/química , Trato Gastrointestinal/virologia , Humanos , Concentração de Íons de Hidrogênio , Leite/virologia , Norovirus/classificação , Norovirus/efeitos dos fármacos , Ensaio de Placa Viral , Inativação de Vírus , Vírus/efeitos dos fármacos
11.
Appl Environ Microbiol ; 81(14): 4850-9, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25956775

RESUMO

Human noroviruses (HNoV) and hepatitis A virus (HAV) have been implicated in outbreaks linked to the consumption of presliced ready-to-eat deli meats. The objectives of this research were to determine the thermal inactivation kinetics of HNoV surrogates (murine norovirus 1 [MNV-1] and feline calicivirus strain F9 [FCV-F9]) and HAV in turkey deli meat, compare first-order and Weibull models to describe the data, and calculate Arrhenius activation energy values for each model. The D (decimal reduction time) values in the temperature range of 50 to 72°C calculated from the first-order model were 0.1 ± 0.0 to 9.9 ± 3.9 min for FCV-F9, 0.2 ± 0.0 to 21.0 ± 0.8 min for MNV-1, and 1.0 ± 0.1 to 42.0 ± 5.6 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) values for FCV-F9, MNV-1, and HAV at the same temperatures ranged from 0.1 ± 0.0 to 11.9 ± 5.1 min, from 0.3 ± 0.1 to 17.8 ± 1.8 min, and from 0.6 ± 0.3 to 25.9 ± 3.7 min, respectively. The z (thermal resistance) values for FCV-F9, MNV-1, and HAV were 11.3 ± 2.1°C, 11.0 ± 1.6°C, and 13.4 ± 2.6°C, respectively, using the Weibull model. The z values using the first-order model were 11.9 ± 1.0°C, 10.9 ± 1.3°C, and 12.8 ± 1.7°C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 214 ± 28, 242 ± 36, and 154 ± 19 kJ/mole, respectively, while the calculated activation energies for the first-order model were 181 ± 16, 196 ± 5, and 167 ± 9 kJ/mole, respectively. Precise information on the thermal inactivation of HNoV surrogates and HAV in turkey deli meat was generated. This provided calculations of parameters for more-reliable thermal processes to inactivate viruses in contaminated presliced ready-to-eat deli meats and thus to reduce the risk of foodborne illness outbreaks.


Assuntos
Doenças Transmitidas por Alimentos/virologia , Vírus da Hepatite A/fisiologia , Produtos da Carne/virologia , Norovirus/fisiologia , Inativação de Vírus , Animais , Contaminação de Alimentos/análise , Vírus da Hepatite A/química , Temperatura Alta , Humanos , Cinética , Norovirus/química , Perus/virologia
12.
Food Microbiol ; 52: 1-10, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26338111

RESUMO

Grape seed extract (GSE) has antiviral activities against hepatitis A virus (HAV) and human norovirus surrogates (feline calicivirus (FCV-F9) and murine norovirus (MNV-1)). The objectives of this study were to determine (1) time and dose-dependence of GSE against FCV-F9, MNV-1, and HAV at room temperature (RT) and 37 °C over 24 h; and (2) GSE effects in model foods (apple juice (AJ) and 2% milk) and simulated gastric conditions at 37 °C. Viruses at ∼5 log PFU/ml were treated with 0.5-8 mg/ml GSE prepared in water, AJ, milk or gastric juices, or water over 24 h at RT or 37 °C. Infectivity of triplicate treatments was evaluated using plaque assays. GSE effects increased with time and concentration. GSE at 1 mg/ml in AJ reduced MNV-1 to undetectable levels after 1 h and by 1 log in milk after 24 h. GSE at 1 and 2 mg/ml in AJ reduced HAV to undetectable levels after 1 h, while 2 and 4 mg/ml GSE in milk caused ∼1 log reduction after 24 h. GSE at 2 mg/ml in intestinal fluid reduced FCV-F9, MNV-1 and HAV to undetectable levels after 6 h. GSE appears to be a suitable natural option for foodborne viral reduction.


Assuntos
Antivirais/farmacologia , Bebidas/virologia , Calicivirus Felino/efeitos dos fármacos , Extrato de Sementes de Uva/farmacologia , Vírus da Hepatite A/efeitos dos fármacos , Leite/virologia , Norovirus/efeitos dos fármacos , Animais , Infecções por Caliciviridae/virologia , Calicivirus Felino/fisiologia , Gatos , Linhagem Celular , Hepatite A/virologia , Vírus da Hepatite A/fisiologia , Humanos , Camundongos , Norovirus/fisiologia , Inativação de Vírus/efeitos dos fármacos
13.
Poult Sci ; 94(6): 1419-30, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25743421

RESUMO

The development of antibiotic resistant pathogens has resulted from the use of sub-therapeutic concentrations of antibiotics delivered in poultry feed. Furthermore, there are a number of consumer concerns regarding the use of antibiotics in food animals including residue contamination of poultry products and antibiotic resistant bacterial pathogens. These issues have resulted in recommendations to reduce the use of antibiotics as growth promoters in livestock in the United States. Unlike conventional production, organic systems are not permitted to use antibiotics. Thus, both conventional and organic poultry production need alternative methods to improve growth and performance of poultry. Herbs, spices, and various other plant extracts are being evaluated as alternatives to antibiotics and some do have growth promoting effects, antimicrobial properties, and other health-related benefits. This review aims to provide an overview of herbs, spices, and plant extracts, currently defined as phytobiotics as potential feed additives.


Assuntos
Ração Animal/análise , Criação de Animais Domésticos/métodos , Anti-Infecciosos/análise , Agricultura Orgânica/métodos , Extratos Vegetais/química , Aves Domésticas , Especiarias/análise , Animais , Anti-Infecciosos/farmacologia , Dieta/veterinária , Extratos Vegetais/farmacologia
14.
Appl Environ Microbiol ; 80(10): 3191-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24632250

RESUMO

Hepatitis A virus (HAV) is a food-borne enteric virus responsible for outbreaks of hepatitis associated with shellfish consumption. The objectives of this study were to determine the thermal inactivation behavior of HAV in blue mussels, to compare the first-order and Weibull models to describe the data, to calculate Arrhenius activation energy for each model, and to evaluate model efficiency by using selected statistical criteria. The times required to reduce the population by 1 log cycle (D-values) calculated from the first-order model (50 to 72°C) ranged from 1.07 to 54.17 min for HAV. Using the Weibull model, the times required to destroy 1 log unit (tD = 1) of HAV at the same temperatures were 1.57 to 37.91 min. At 72°C, the treatment times required to achieve a 6-log reduction were 7.49 min for the first-order model and 8.47 min for the Weibull model. The z-values (changes in temperature required for a 90% change in the log D-values) calculated for HAV were 15.88 ± 3.97°C (R(2), 0.94) with the Weibull model and 12.97 ± 0.59°C (R(2), 0.93) with the first-order model. The calculated activation energies for the first-order model and the Weibull model were 165 and 153 kJ/mol, respectively. The results revealed that the Weibull model was more appropriate for representing the thermal inactivation behavior of HAV in blue mussels. Correct understanding of the thermal inactivation behavior of HAV could allow precise determination of the thermal process conditions to prevent food-borne viral outbreaks associated with the consumption of contaminated mussels.


Assuntos
Culinária/métodos , Contaminação de Alimentos/análise , Vírus da Hepatite A/crescimento & desenvolvimento , Mytilus edulis/virologia , Frutos do Mar/virologia , Inativação de Vírus , Animais , Vírus da Hepatite A/química , Vírus da Hepatite A/fisiologia , Temperatura Alta , Cinética
15.
Food Microbiol ; 42: 212-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24929739

RESUMO

Human noroviruses and hepatitis A virus (HAV) are considered as epidemiologically significant causes of foodborne disease. Therefore, studies are needed to bridge existing data gaps and determine appropriate parameters for thermal inactivation of human noroviruses and HAV. The objectives of this research were to compare the thermal inactivation kinetics of human norovirus surrogates (murine norovirus (MNV-1), and feline calicivirus (FCV-F9)) and HAV in buffered medium (2-ml vials), compare first-order and Weibull models to describe the data, calculate Arrhenius activation energy for each model, and evaluate model efficiency using selected statistical criteria. The D-values calculated from the first-order model (50-72 °C) ranged from 0.21-19.75 min for FCV-F9, 0.25-36.28 min for MNV-1, and 0.88-56.22 min for HAV. Using the Weibull model, the tD = 1 (time to destroy 1 log) for FCV-F9, MNV-1 and HAV at the same temperatures ranged from 0.10-13.27, 0.09-26.78, and 1.03-39.91 min, respectively. The z-values for FCV-F9, MNV-1, and HAV were 9.66 °C, 9.16 °C, and 14.50 °C, respectively, using the Weibull model. For the first order model, z-values were 9.36 °C, 9.32 °C, and 12.49 °C for FCV-F9, MNV-1, and HAV, respectively. For the Weibull model, estimated activation energies for FCV-F9, MNV-1, and HAV were 225, 278, and 182 kJ/mol, respectively, while the calculated activation energies for the first order model were 195, 202, and 171 kJ/mol, respectively. Knowledge of the thermal inactivation kinetics of norovirus surrogates and HAV will allow the development of processes that produce safer food products and improve consumer safety.


Assuntos
Calicivirus Felino/crescimento & desenvolvimento , Meios de Cultura/química , Vírus da Hepatite A/crescimento & desenvolvimento , Norovirus/crescimento & desenvolvimento , Esterilização/métodos , Inativação de Vírus , Animais , Calicivirus Felino/química , Vírus da Hepatite A/química , Humanos , Cinética , Norovirus/química , Norovirus/classificação , Esterilização/instrumentação , Temperatura
16.
Food Microbiol ; 39: 127-31, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24387862

RESUMO

Blueberry juice and blueberry polyphenols reportedly have antimicrobial properties against foodborne pathogens, without much currently known on their effects against Cronobacter sakazakii. This study evaluated the antimicrobial effects of blueberry proanthocyanidins (PAC) and commercial blueberry juice (BJ) against two strains of C. sakazakii, ATCC 29004 and 29544. BJ (pH 2.8), blueberry PAC (5 mg/ml) and controls (phosphate buffered saline (PBS), pH 7.2, and malic acid pH 3.0) were mixed with equal volumes of washed overnight cultures of C. sakazakii and incubated for 30 min, 1 h, 3 h and 6 h at 37°C. Reductions of ∼1 and 1.50 log CFU/ml were obtained for strains 29004 and 29544, respectively after 30 min with BJ or blueberry PAC. Both C. sakazakii strains 29004 and 29544 were reduced to undetectable levels from 8.25 ± 0.12 log CFU/ml and 8.48 ± 0.03 log CFU/ml, respectively with BJ (pH 2.8) or blueberry PAC after 1 h, while malic acid (pH 3.0) showed ∼1.3 log CFU/ml reduction for both strains. Scanning electron microscopy studies showed differences in cell membrane morphology with clumping and formation of blebs of the treated strains compared to untreated controls. These results warrant further in vivo studies with blueberry bioactives to determine potential for preventing and treating C. sakazakii infections.


Assuntos
Antibacterianos/farmacologia , Mirtilos Azuis (Planta)/química , Cronobacter sakazakii/efeitos dos fármacos , Extratos Vegetais/farmacologia , Proantocianidinas/farmacologia , Cronobacter sakazakii/crescimento & desenvolvimento , Frutas/química
17.
Environ Geochem Health ; 36(3): 421-5, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24026572

RESUMO

Groundwater used for drinking and cooking was analysed for fluoride (F), and health surveys were conducted in Bodh Gaya, Amas and Bankebazaar blocks of the Gaya district, Bihar, India. Amas and Bankebazaar blocks were F endemic areas with mean F = 2.36 ± 0.23 mg/L (N = 27). Bodh Gaya was considered as control area with mean F = 0.59 ± 0.03 mg/L (N = 11). Health survey showed that more than 50 % of adults and more than 55 % of children had complaints of gastro-intestinal (GI) disturbances in the F endemic areas, while less than 20 % of adults and less than 10 % of children complained of GI problems in the control areas. Haematological analyses were conducted on age- and sex-matched fluorotic subjects (N = 93) of F endemic areas, and non-fluorotic subjects (N = 52) of control area showed lowered haemoglobin, haematocrit, mean corpuscular volume, mean corpuscular haemoglobin, and mean corpuscular haemoglobin concentration in the fluorotic subjects, suggesting the occurrence of anaemia in the fluorotic subjects.


Assuntos
Fluoretos/toxicidade , Gastroenteropatias/sangue , Testes Hematológicos , Adulto , Estudos de Casos e Controles , Criança , Água Potável/química , Doenças Endêmicas , Fluoretos/análise , Gastroenteropatias/epidemiologia , Inquéritos Epidemiológicos , Humanos , Índia/epidemiologia
18.
Food Microbiol ; 34(1): 1-6, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23498171

RESUMO

Grape seed extract (GSE) is reported to have antibacterial properties with few current studies on antiviral activity. Recently, we reported the effects of GSE against foodborne viral surrogates in vitro. This study evaluated the application of GSE (commercial Gravinol-S) against hepatitis A virus (HAV) and human norovirus surrogates, feline calicivirus (FCV-F9) and murine norovirus (MNV-1), on model produce. Washed and air-dried lettuce (3 × 3 cm(2)) and jalapeno peppers (25-30 g) were inoculated with FCV-F9, MNV-1, or HAV at high (∼7 log10 PFU/ml) or low (∼5 log10 PFU/ml) titers, and treated with 0.25, 0.5, 1 mg/ml GSE or water for 30 s to 5 min. Treatments were stopped/diluted with cell-culture media containing 10% heat-inactivated fetal bovine serum and evaluated using plaque assays. At high titers, FCV-F9 was reduced by 2.33, 2.58, and 2.71 log10 PFU on lettuce; and 2.20, 2.74, and 3.05 log10 PFU on peppers after 1 min using 0.25, 0.50, and 1 mg/ml GSE, respectively. Low FCV-F9 titers could not be detected after 1 min at all three GSE concentrations. Low titer MNV-1 was reduced by 0.2-0.3 log10 PFU on lettuce and 0.8 log10 PFU on peppers, without reduction of high titer. GSE at 0.25-1 mg/ml after 1 min caused 0.7-1.1 and 1-1.3 log10 PFU reduction for high and low HAV titers, respectively on both commodities. Instrumental color analysis showed no significant differences between treated and untreated produce. GSE shows potential for foodborne viral reduction on produce as part of hurdle technologies.


Assuntos
Capsicum/virologia , Extrato de Sementes de Uva/farmacologia , Lactuca/virologia , Vírus/efeitos dos fármacos , Antivirais/farmacologia , Doenças Transmitidas por Alimentos/virologia , Humanos , Inativação de Vírus/efeitos dos fármacos
19.
Sensors (Basel) ; 13(5): 5737-48, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23645110

RESUMO

Many rapid methods have been developed for screening foods for the presence of pathogenic microorganisms. Rapid methods that have the additional ability to identify microorganisms via multiplexed immunological recognition have the potential for classification or typing of microbial contaminants thus facilitating epidemiological investigations that aim to identify outbreaks and trace back the contamination to its source. This manuscript introduces a novel, high throughput typing platform that employs microarrayed multiwell plate substrates and laser-induced fluorescence of the nucleic acid intercalating dye/stain SYBR Gold for detection of antibody-captured bacteria. The aim of this study was to use this platform for comparison of different sets of antibodies raised against the same pathogens as well as demonstrate its potential effectiveness for serotyping. To that end, two sets of antibodies raised against each of the "Big Six" non-O157 Shiga toxin-producing E. coli (STEC) as well as E. coli O157:H7 were array-printed into microtiter plates, and serial dilutions of the bacteria were added and subsequently detected. Though antibody specificity was not sufficient for the development of an STEC serotyping method, the STEC antibody sets performed reasonably well exhibiting that specificity increased at lower capture antibody concentrations or, conversely, at lower bacterial target concentrations. The favorable results indicated that with sufficiently selective and ideally concentrated sets of biorecognition elements (e.g., antibodies or aptamers), this high-throughput platform can be used to rapidly type microbial isolates derived from food samples within ca. 80 min of total assay time. It can also potentially be used to detect the pathogens from food enrichments and at least serve as a platform for testing antibodies.


Assuntos
Anticorpos Antibacterianos/metabolismo , Técnicas de Tipagem Bacteriana/métodos , Escherichia coli O157/classificação , Escherichia coli O157/imunologia , Ensaios de Triagem em Larga Escala/métodos , Análise em Microsséries/métodos , Contagem de Colônia Microbiana , Escherichia coli O157/crescimento & desenvolvimento , Fluorescência , Lasers
20.
Poult Sci ; 92(2): 562-72, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23300324

RESUMO

The era of molecular biology and automation of the Sanger chain-terminator sequencing method has led to discovery and advances in diagnostics and biotechnology. The Sanger methodology dominated research for over 2 decades, leading to significant accomplishments and technological improvements in DNA sequencing. Next-generation high-throughput sequencing (HT-NGS) technologies were developed subsequently to overcome the limitations of this first generation technology that include higher speed, less labor, and lowered cost. Various platforms developed include sequencing-by-synthesis 454 Life Sciences, Illumina (Solexa) sequencing, SOLiD sequencing (among others), and the Ion Torrent semiconductor sequencing technologies that use different detection principles. As technology advances, progress made toward third generation sequencing technologies are being reported, which include Nanopore Sequencing and real-time monitoring of PCR activity through fluorescent resonant energy transfer. The advantages of these technologies include scalability, simplicity, with increasing DNA polymerase performance and yields, being less error prone, and even more economically feasible with the eventual goal of obtaining real-time results. These technologies can be directly applied to improve poultry production and enhance food safety. For example, sequence-based (determination of the gut microbial community, genes for metabolic pathways, or presence of plasmids) and function-based (screening for function such as antibiotic resistance, or vitamin production) metagenomic analysis can be carried out. Gut microbialflora/communities of poultry can be sequenced to determine the changes that affect health and disease along with efficacy of methods to control pathogenic growth. Thus, the purpose of this review is to provide an overview of the principles of these current technologies and their potential application to improve poultry production and food safety as well as public health.


Assuntos
Criação de Animais Domésticos/métodos , Inocuidade dos Alimentos/métodos , Genômica/métodos , Técnicas de Amplificação de Ácido Nucleico/veterinária , Animais , Campylobacter/genética , Campylobacter/isolamento & purificação , Campylobacter/fisiologia , Infecções por Campylobacter/microbiologia , Infecções por Campylobacter/veterinária , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/fisiologia , Genômica/economia , Técnicas de Amplificação de Ácido Nucleico/economia , Técnicas de Amplificação de Ácido Nucleico/métodos , Aves Domésticas , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Salmonella enterica/fisiologia
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