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1.
ScientificWorldJournal ; 2021: 3119958, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34594160

RESUMO

Fish and fish products are considered a fundamental part of the human diet due to their high nutritional value. Food-borne diseases are considered a major public health challenge worldwide due to their incidence, associated mortality, and negative economic repercussions. Food safety is the guarantee that foods will not cause harm to the health of those who consume them, and it is a fundamental property of food quality. Food safety can be at risk of being lost at any stage of the food chain if the food is contaminated by pathogenic microorganisms. Many diverse bacteria are present in the environment and as part of the microbiota of food that can be transmitted to humans during the handling and consumption of food. Plesiomonas shigelloides has been mainly associated with outbreaks of gastrointestinal diseases due to the consumption of fish. This bacterium inhabits the environment and aquatic animals and is associated with the microbiota of fish such as tilapia, a fish of importance in fishing, aquaculture, commercialization, and consumption worldwide. The purpose of this document is to provide, through a bibliographic review of databases (Scopus, Web of Science, and Google Scholar, among others), a general informative perspective on food-borne diseases and, in particular, the consumption of fish and tilapia. Diseases derived from contamination by Plesiomonas shigelloides are included, and control and prevention actions and sanitary regulations for fishery products established in several countries around the world are discussed to promote the safety of foods of aquatic origin intended for human consumption and to protect public health.


Assuntos
Doenças dos Peixes/microbiologia , Contaminação de Alimentos , Microbiologia de Alimentos , Gastroenterite/microbiologia , Infecções por Bactérias Gram-Negativas/veterinária , Plesiomonas/isolamento & purificação , Alimentos Marinhos/microbiologia , Tilápia/microbiologia , Animais , Aquicultura , Carga Bacteriana , Criopreservação , Reservatórios de Doenças , Produtos Pesqueiros/microbiologia , Manipulação de Alimentos , Conservação de Alimentos , Inocuidade dos Alimentos , Gastroenterite/epidemiologia , Gastroenterite/etiologia , Gastroenterite/prevenção & controle , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Plesiomonas/crescimento & desenvolvimento , Prevalência , Controle de Qualidade , Poluição da Água
2.
Int J Food Microbiol ; 354: 109326, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34247024

RESUMO

Serratia sp. cause food losses and waste due to spoilage; it is noteworthy that they represent a dominant population in seafood. The main spoilage associated species comprise S. liquefaciens, S. grimesii, S. proteamaculans and S. quinivorans, also known as S. liquefaciens-like strains. These species are difficult to discriminate since classical 16S rRNA gene-based sequences do not possess sufficient resolution. In this study, a phylogeny based on the short-length luxS gene was able to speciate 47 Serratia isolates from seafood, with S. proteamaculans being the main species from fresh salmon and tuna, cold-smoked salmon, and cooked shrimp while S. liquefaciens was only found in cold-smoked salmon. The genome of the first S. proteamaculans strain isolated from the seafood matrix (CD3406 strain) was sequenced. Pangenome analyses of S. proteamaculans and S. liquefaciens indicated high adaptation potential. Biosynthetic pathways involved in antimicrobial compounds production and in the main seafood spoilage compounds were also identified. The genetic equipment highlighted in this study contributed to gain further insights into the predominance of Serratia in seafood products and their capacity to spoil.


Assuntos
Microbiologia de Alimentos , Variação Genética , Genoma Bacteriano , Alimentos Marinhos , Serratia liquefaciens , Serratia , Genoma Bacteriano/genética , RNA Ribossômico 16S/genética , Alimentos Marinhos/microbiologia , Serratia/genética , Serratia liquefaciens/genética
3.
Biochem Biophys Res Commun ; 571: 125-130, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34325127

RESUMO

This study investigated the properties of Latilactobacillus curvatus MS2 isolated from Korean traditional fermented seafood as probiotics and the effect of reducing cholesterol as a synbiotic with isomalto-oligosaccharide (IMO) in BALB/c mice. The isolated strain showed high resistance to acids and bile acids and exhibited a high DPPH scavenging capacity of 72.27 ± 0.38 %. In the intestinal adhesion test using HT-29 cells, the adhesion rate of MS2 was 17.10 ± 1.78 %, which was higher than the adhesion rate of the other investigated probiotics. MS2 showed good antimicrobial activity against food-borne pathogens, especially Staphylococcus aureus, S. epidermidis, Escherichia coli, and Vibrio vulnificus. This strain had high availability for IMO among the prebiotics of fructo-oligosaccharide, inulin and IMO. Oral administration of MS2 and IMO to BALB/c mice for 5 weeks resulted in a significant reduction in blood cholesterol levels by regulating liver lipid metabolism. These results suggest that the combination of MS2 and IMO has potential for application in functional foods.


Assuntos
Colesterol/metabolismo , Fermentação , Lactobacillaceae/isolamento & purificação , Oligossacarídeos/metabolismo , Prebióticos/microbiologia , Alimentos Marinhos/microbiologia , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , República da Coreia , Simbióticos
4.
Int J Biol Macromol ; 184: 666-677, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34146561

RESUMO

The roselle anthocyanin extracts (RAE) were immobilized into polyvinyl alcohol (PVA)/hydroxypropyl methylcellulose (HPMC) film matrix, their interaction behavior and mechanism was fully understood for better shrimp freshness monitoring. Structural characterizations revealed RAE was firmly immobilized PVA/HPMC matrix by hydrogen bonds. With increasing RAE contents, dramatic increases of film thickness (from 15.90 ± 0.14 to 23.20 ± 3.35 µm), tensile strength (from 45.66 ± 1.07 to 56.98 ± 0.24 MPa), light barrier and active properties (increased by 83.18% for antioxidant and 146.91%, 59.18% for antibacterial activity against E. coli and S. aureus) were observed, while hydrophobic properties decreased significantly. Owing to great ammonia-sensitive ability, the PVA/HPMC/RAE (PHR) films were applied on shrimp freshness qualitative monitoring and greater visible color variations were identified with increasing RAE contents. Furthermore, mathematical models were established for quantitative monitoring. In conclusion, with the increasing RAE contents, the tighter interaction between RAE and PVA/HPMC matrix contributed to the better functional properties and freshness monitoring effects of PHR films.


Assuntos
Antocianinas/farmacologia , Antibacterianos/farmacologia , Antioxidantes/farmacologia , Hibiscus/química , Derivados da Hipromelose/química , Álcool de Polivinil/química , Antocianinas/química , Antibacterianos/química , Antioxidantes/química , Escherichia coli/efeitos dos fármacos , Embalagem de Alimentos , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Modelos Teóricos , Alimentos Marinhos/microbiologia , Staphylococcus aureus/efeitos dos fármacos , Resistência à Tração
5.
Int J Food Microbiol ; 358: 109285, 2021 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-34144838

RESUMO

Widespread in very diverse environments, the spores of Bacillus cereus are highly resistant to hostile conditions and can contaminate a huge variety of food products, posing a potential health hazard to consumers. Given this significant risk, the objective of this research work was to study the impacts of electro-activated solutions (EAS) made with calcium ascorbate, calcium lactate, and their equimolar mixture on Bacillus cereus ATCC 14579 spores in model conditions and food matrix, the fresh Atlantic salmon. The model conditions consisted of a direct application of the EAS to the spores, which avoided any interference with factors external to those of the solutions. Salmon was chosen as a food model because it is a product sensitive to bacterial spoilage and can be eaten raw. To achieve this, the solutions were prepared by electro-activation using an electric current with an intensity of 750 mA for 30 min, resulting in mean pH values of 1.94 ± 0.15-2.16 ± 0.01 and titratable acidity of 0.102 ± 0.001-0.109 ± 0.001 mol/L, depending on the type of solution. These conditions were chosen because of their excellent antibacterial efficacy previously demonstrated against vegetative cells of B. cereus. The results showed high sporicidal activities of the EAS against B. cereus with a 7 to 9 log reduction, using an initial spore population of 109 CFU/mL, depending on the conditions evaluated, namely: in direct contact (2-30 min), in salmon used as a food matrix (2-7 min), and in combination with moderate heat treatments from 60 to 90 °C (0.5-2 min). In addition, it was observed that the sporicidal capacity of the EAS increased with temperature and the contact time. Otherwise, analysis of the color and lipids of the salmon have not shown any major impacts of the use of EAS as a rinsing solution for this highly perishable food. Furthermore, micrographs taken by scanning and transmission electron microscopy revealed the destructive effects of the EAS used in the vital structures/components of the spores. In general, this study has demonstrated that the electro-activation technology is effective in producing EAS capable of destroying/inactivating B. cereus spores and that they can be used for the improvement of food safety and preservation.


Assuntos
Bacillus cereus , Contaminação de Alimentos/prevenção & controle , Microbiologia de Alimentos , Salmo salar , Alimentos Marinhos/microbiologia , Animais , Ácido Ascórbico , Compostos de Cálcio , Contagem de Colônia Microbiana , Temperatura Alta , Lactatos , Esporos Bacterianos
6.
Folia Microbiol (Praha) ; 66(5): 787-795, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34128186

RESUMO

Bacillus licheniformis HJ4 showing strong fibrinolytic activity was isolated from Hwangseokae jeotgal. aprEHJ4, a major fibrinolytic gene, was cloned by PCR, and an ORF consisting of 379 amino acids was located. The mature enzyme was expected to be 27 kDa in size after processing, but a 24-kDa protein was observed by SDS-PAGE and fibrin zymography, indicating additional processing. RT-qPCR showed that expression level of aprEHJ4 in culture with 0% salt (control) was the highest followed by culture with 8% salt (89.7% of control) and 5% salt (74.2%) at 84 h. The expression level in culture with 15% salt was 46.9%. The results matched with the fibrinolytic activity measurements of cultures and indicated that AprEHJ4 maintained significant activity in the presence of salt up to 15% (w/v). AprEHJ4 was overproduced in Escherichia coli, and mature 27 kDa protein was purified after in vitro renaturation. The optimum pH and temperature of AprEHJ4 were pH 8 and 40 ℃, respectively.


Assuntos
Bacillus licheniformis , Alimentos e Bebidas Fermentados , Alimentos Marinhos , Bacillus licheniformis/enzimologia , Ativação Enzimática/efeitos dos fármacos , Alimentos e Bebidas Fermentados/microbiologia , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/metabolismo , República da Coreia , Alimentos Marinhos/microbiologia , Cloreto de Sódio/farmacologia
7.
Mol Immunol ; 135: 373-387, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34020083

RESUMO

Vibrio parahaemolyticus causes vibriosis in wide range of marine organisms, and is responsible for food borne illnesses in humans through consumption of contaminated uncooked/partially cooked seafood. Continued and widespread antibiotics usage to increase the productivity has led to antibiotics resistance development. This has necessitated the need to develop alternative methods to control its infection. Use of safe and effective vaccines against the virulence factors not only protects from infection, it also minimizes antibiotic usage. The colonization of V. parahaemolyticus in the host and disease development requires several adhesins present on the cell surface, and thereby make them attractive vaccine candidates. V. parahaemolyticus produces extracellular type 1 fimbriae that have been shown to play a role in adhesion, biofilm formation and virulence. FimH is one of the minor components of the type 1 fimbriae occurring on its very tip. Being present on the cell surface, it is highly immunogenic, and can be targeted as a potential vaccine candidate. The present study describes the immunogenic and vaccine potential of recombinant V. parahaemolyticus FimH (rVpFimH) expressed in E. coli. Immunization of BALB/c mice with the rVpFimH elicited a strong mixed immune response, T-cell memory (evidenced by antibody isotyping, cytokine profiling and T-cell proliferation assay), and agglutination positive antibodies. FACS analysis and immunogold labeling showed that the polyclonal anti-rVpFimH antibodies were able to recognize the FimH on V. parahaemolyticus cells. In vivo challenge of the rVpFimH-immunized mice with 2×LD50 dose of live bacteria showed one hundred percent survival. Thus, our findings clearly demonstrate the potential of FimH as an effective vaccine candidate against V. parahaemolyticus.


Assuntos
Adesinas Bacterianas/imunologia , Vacinas Bacterianas/imunologia , Proteínas de Fímbrias/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Vibrioses/prevenção & controle , Vibrio parahaemolyticus/imunologia , Adesinas Bacterianas/genética , Animais , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/imunologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Biofilmes/crescimento & desenvolvimento , Modelos Animais de Doenças , Proteínas de Fímbrias/genética , Doenças Transmitidas por Alimentos/microbiologia , Imunização , Camundongos , Camundongos Endogâmicos BALB C , Alimentos Crus/microbiologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Alimentos Marinhos/microbiologia , Vibrioses/imunologia , Vibrio parahaemolyticus/genética , Virulência , Fatores de Virulência/genética , Fatores de Virulência/imunologia
8.
Int J Food Microbiol ; 349: 109227, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34022613

RESUMO

The present work mainly investigated the effects of prepared chitosan­sodium alginate-nisin (CS-SA-N) preservatives on the quality and bacterial phase of Penaeus vannamei shrimp during cold storage. Results showed that CS-SA-N preservatives treated samples had the lower pH, total volatile basic nitrogen (TVB-N), total viable count (TVC), and freeness (K) values than those of untreated ones during cold storage. The sensory evaluation results indicated that CS-SA-N preservatives treated shrimps had the higher comprehensive scores than those of untreated ones during whole storage. Microbial community of all samples was dominated by Proteobacteria. The initial predominant bacteria of fresh shrimps were Sphingomonas, Carnobacterium and Psychrobacter. Psychrobacter, Pseudomonas, and Shewanella, Acinetobacter and Vibrio were the predominant bacteria of untreated samples. CS-SA-N preservatives significantly decreased predominant microbial numbers by inhibiting the growth of Psychrobacter, Vibrio, Acinetobacter and Carnobacterium during cold storage. Therefore, the CS-SA-N preservatives could be used to prolong the shelf life of shrimp and guarantee its quality.


Assuntos
Conservantes de Alimentos/farmacologia , Armazenamento de Alimentos/métodos , Microbiota/efeitos dos fármacos , Penaeidae/microbiologia , Alimentos Marinhos/microbiologia , Alginatos/farmacologia , Animais , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Quitosana/farmacologia , Nisina/farmacologia , Nitrogênio/análise , Alimentos Marinhos/análise
9.
Int J Biol Macromol ; 183: 2199-2204, 2021 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-34058208

RESUMO

Effects of the eugenol-chitosan nanoemulsion as an edible coating on the quality of hairtail (Trichiurus haumela) during storage at 4 °C were evaluated. For all samples, such parameters as pH, thiobarbituric acid (TBA), total volatile basic nitrogen (TVB-N), water holding capacity (WHC), electrical conductivity (EC), total bacteria count (TVC) and sensory were examined periodically. The results demonstrated that eugenol-chitosan nanoemulsion coating showed better preservative effects than chitosan nanoemulsion alone. Therefore, a coating based on eugenol-chitosan nanoemulsion could be regarded as an effective food-grade biopreservative to maintain the quality of hairtail fish and prolong its shelf life during chilled storage.


Assuntos
Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Quitosana/farmacologia , Filmes Comestíveis , Eugenol/farmacologia , Microbiologia de Alimentos , Embalagem de Alimentos , Conservação de Alimentos , Armazenamento de Alimentos , Perciformes , Refrigeração , Alimentos Marinhos/análise , Animais , Anti-Infecciosos/química , Antioxidantes/química , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Quitosana/análogos & derivados , Quitosana/química , Condutividade Elétrica , Emulsões , Eugenol/química , Qualidade dos Alimentos , Peroxidação de Lipídeos/efeitos dos fármacos , Nanopartículas , Perciformes/microbiologia , Alimentos Marinhos/microbiologia , Fatores de Tempo , Água/análise
10.
Arch Microbiol ; 203(6): 3317-3330, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33864113

RESUMO

The continual increase in resistance to antibacterial drugs has become a major public health problem, and their indiscriminate use in agriculture, aquaculture, and the treatment of human and animal diseases has severely contributed to the occurrence and spread of multidrug resistance genes. This study phylogenetically characterized multidrug-resistant bacteria isolated from seafood cocktails. Seafood cocktail dishes from 20 establishments on public roads were sampled. Samples were grown on TCBS agar and blood agar. Forty colonies with different macro- and microscopic characteristics were isolated. The 16S rRNA gene V4 and V6 hypervariable regions were amplified, sequenced and phylogenetically analyzed. Antibacterial drug resistance was determined by disk diffusion assay. Isolated bacteria were identical to species of the genera Enterococcus, Proteus, Vibrio, Staphylococcus, Lactococcus, Vagococcus, Micrococcus, Acinetobacter, Enterobacter, and Brevibacterium, with 75-100% presenting resistance or intermediate resistance to dicloxacillin, ampicillin, and penicillin; 50-70% to cephalosporins; 30-67.5% to amikacin, netilmicin and gentamicin; 40% to nitrofurantoin and other antibacterial drugs; 25% to chloramphenicol; and 2.5% to trimethoprim with sulfamethoxazole. In general, 80% of the bacteria showed resistance to multiple antibiotics. The high degree of bacterial resistance to antibacterial drugs indicates that their use in producing raw material for marine foods requires established guidelines and the implementation of good practices.


Assuntos
Bactérias/isolamento & purificação , Farmacorresistência Bacteriana Múltipla , Alimentos Marinhos/microbiologia , Bactérias/classificação , Bactérias/genética , Filogenia
11.
Int J Food Microbiol ; 347: 109166, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-33838478

RESUMO

Listeria monocytogenes is a foodborne human pathogen that causes systemic infection, fetal-placental infection in pregnant women causing abortion and stillbirth and meningoencephalitis in elderly and immunocompromised individuals. This study aimed to analyse L. monocytogenes from different sources from New Zealand (NZ) and to compare them with international strains. We used pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST) and whole-genome single nucleotide polymorphisms (SNP) to study the population structure of the NZ L. monocytogenes isolates and their relationship with the international strains. The NZ isolates formed unique clusters in PFGE, MLST and whole-genome SNP comparisons compared to the international isolates for which data were available. PFGE identified 31 AscI and 29 ApaI PFGE patterns with indistinguishable pulsotypes being present in seafood, horticultural products and environmental samples. Apart from the Asc0002:Apa0002 pulsotype which was distributed across different sources, other pulsotypes were site or factory associated. Whole-genome analysis of 200 randomly selected L. monocytogenes isolates revealed that lineage II dominated the NZ L. monocytogenes populations. MLST comparison of international and NZ isolates with lineage II accounted for 89% (177 of 200) of the total L. monocytogenes population, while the international representation was 45.3% (1674 of 3473). Rarefaction analysis showed that sequence type richness was greater in NZ isolates compared to international trend, however, it should be noted that NZ isolates predominantly came from seafood, horticulture and their respective processing environments or factories, unlike international isolates where there was a good mixture of clinical, food and environmental isolates.


Assuntos
Microbiologia Ambiental , Genoma Bacteriano/genética , Listeria monocytogenes/genética , Listeria monocytogenes/isolamento & purificação , Alimentos Marinhos/microbiologia , Manipulação de Alimentos , Microbiologia de Alimentos , Variação Genética , Horticultura , Humanos , Listeria monocytogenes/classificação , Nova Zelândia
12.
Food Microbiol ; 98: 103664, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33875195

RESUMO

Vibrio vulnificus is an important foodborne pathogenic bacterium that mainly contaminates seafood. Rapid and accurate technologies that suitable for on-site detection are critical for effective control of its spreading. Conventional detection methods and polymerase chain reaction (PCR)-based and qPCR-based approaches have application limitations in on-site scenarios. Application of loop-mediated isothermal amplification (LAMP) technology was a good step towards the on-site detection. In this study, a recombinase polymerase amplification (RPA)-based detection method for V. vulnificus was developed combining with lateral flow strip (LFS) for visualized signal. The method targeted the conservative empV gene encoding the extracellular metalloproteinase, and finished detection in 35 min at a conveniently low temperature of 37 °C. It showed good specificity and an excellent sensitivity of 2 copies of the genome or 10-1 colony forming unit (CFU) per reaction, or 1 CFU/10 g in spiked food samples with enrichment. The method tolerated unpurified templates directly from sample boiling, which added the convenience of the overall procedure. Application of the RPA-LFS method for clinical samples showed accurate and consistent detection results compared to bioassay and quantitative PCR. This RPA-LFS combined method is well suited for on-site detection of V. vulnificus.


Assuntos
Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Alimentos Marinhos/microbiologia , Vibrio vulnificus/isolamento & purificação , Animais , Contaminação de Alimentos/análise , Recombinases/química , Recombinases/metabolismo , Alimentos Marinhos/análise , Sensibilidade e Especificidade , Vibrio vulnificus/classificação , Vibrio vulnificus/genética
13.
Lett Appl Microbiol ; 73(2): 176-186, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33891720

RESUMO

Aeromonas spp. are associated with seafood-related outbreaks worldwide. In seafood industry, shellfish play a major role in global seafood production. With this emerging trend of shellfish consumption, shellfish-related bacterial infections are being reported frequently. Aeromonas spp. are natural contaminants found in shellfish. Although 36 species have been identified, some species including Aeromonas hydrophila, Aeromonas caviae and Aeromonas veronii biotype sobria have dragged major attention as foodborne pathogenic bacteria. The ability to elaborate a variety of virulence factors of Aeromonas spp. contributes to the pathogenic activities. Also, emerging antimicrobial resistance in Aeromonas spp. has become a huge challenge in seafood industry. Furthermore, multidrug resistance increases the risk of consumer health. Studies have supplied pieces of evidence about the emerging health risk of Aeromonas spp. isolated from seafood. Therefore, the present review was intended to highlight the prevalence, virulence and antimicrobial resistance of Aeromonas spp. isolated from various types of shellfish.


Assuntos
Aeromonas/efeitos dos fármacos , Aeromonas/patogenicidade , Farmacorresistência Bacteriana , Frutos do Mar/microbiologia , Virulência , Aeromonas caviae/efeitos dos fármacos , Aeromonas caviae/patogenicidade , Aeromonas hydrophila/efeitos dos fármacos , Aeromonas hydrophila/patogenicidade , Aeromonas veronii/efeitos dos fármacos , Aeromonas veronii/patogenicidade , Animais , Antibacterianos/farmacologia , Biofilmes , Contaminação de Alimentos , Microbiologia de Alimentos , Humanos , Prevalência , Alimentos Marinhos/microbiologia , Fatores de Virulência
14.
PLoS One ; 16(4): e0250648, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33905441

RESUMO

The frequency of foodborne outbreaks epidemiologically associated with Listeria monocytogenes in fresh produce has increased in recent years. Although L. monocytogenes may be transferred from the environment to vegetables during farming, contamination of food products most commonly occurs in food processing facilities, where L. monocytogenes has the ability to establish and persist on processing equipment. The current study was undertaken to collect data on the occurrence of L. monocytogenes and the identity of the endogenous microbiota in a fresh produce processing facility, for which information has remained scarce. L. monocytogenes was not detected in the facility. Experiments simulating conditions in the processing environment were performed, including examination of bacterial growth in nutrients based on vegetables (salad juice) compared to in other types of nutrients (fish, meat). Results showed that the endogenous microbiota (dominated by Pseudomonas) grew well in iceberg lettuce and rocket salad juice at low temperatures, while growth inhibition of L. monocytogenes was observed, particularly in rocket salad juice. The anti-listerial activity in rocket salad juice was retained in a polar chromatographic fraction containing several metabolites. Characterization of this active fraction, using LC-MS/MS, led to identification of 19 compounds including nucleosides and amino acids. Further work is necessary to determine the molecular mechanism responsible for the inhibitory activity of rocket salad constituents. The study nevertheless suggests that the available nutrients, as well as a low temperature (3 °C) and the in-house bacterial flora, may influence the prevalence of L. monocytogenes in fresh produce processing facilities.


Assuntos
Brassicaceae/química , Microbiologia de Alimentos , Sucos de Frutas e Vegetais/microbiologia , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão , Temperatura Baixa , Manipulação de Alimentos/métodos , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento , Microbiota , Extratos Vegetais/farmacologia , Alimentos Marinhos/microbiologia , Espectrometria de Massas em Tandem , Verduras/microbiologia
15.
J Microbiol Biotechnol ; 31(5): 733-739, 2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-33820890

RESUMO

Acinetobacter strains are widely present in the environment. Some antimicrobial-resistant strains of this genus have been implicated in infections acquired in hospitals. Genetic similarities have been reported between Acinetobacter strains in nosocomial infections and those isolated from foods. However, the antimicrobial resistance of Acinetobacter strains in foods, such as meat, remains unclear. This study initially aimed to isolate Campylobacter strains; instead, strains of the genus Acinetobacter were isolated from meat products, and their antimicrobial resistance was investigated. In total, 58 Acinetobacter strains were isolated from 381 meat samples. Of these, 32 strains (38.6%) were from beef, 22 (26.5%) from pork, and 4 (4.8%) from duck meat. Antimicrobial susceptibility tests revealed that 12 strains were resistant to more than one antimicrobial agent, whereas two strains were multidrug-resistant; both strains were resistant to colistin. Cephalosporin antimicrobials showed high minimal inhibitory concentration against Acinetobacter strains. Resfinder analysis showed that one colistin-resistant strain carried mcr-4.3; this plasmid type was not confirmed, even when analyzed with PlasmidFinder. Analysis of the contig harboring mcr-4.3 using BLAST confirmed that this contig was related to mcr-4.3 of Acinetobacter baumannii. The increase in antimicrobial resistance in food production environments increases the resistance rate of Acinetobacter strains present in meat, inhibits the isolation of Campylobacter strains, and acts as a medium for the transmission of antimicrobial resistance in the environment. Therefore, further investigations are warranted to prevent the spread of antimicrobial resistance in food products.


Assuntos
Acinetobacter/efeitos dos fármacos , Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Carne/microbiologia , Acinetobacter/genética , Acinetobacter/isolamento & purificação , Animais , Campylobacter/isolamento & purificação , Bovinos , Colistina/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Microbiologia de Alimentos , Genes Bacterianos , Testes de Sensibilidade Microbiana , Aves Domésticas/microbiologia , Alimentos Marinhos/microbiologia , Suínos
16.
Int J Food Microbiol ; 346: 109162, 2021 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-33827003

RESUMO

A new cardinal parameter growth and growth boundary model for non-proteolytic C. botulinum was developed and validated for fresh and lightly preserved seafood and poultry products. 523 growth rates in broth were used to determine cardinal parameter values and terms for temperature, pH, NaCl/water activity, acetic, benzoic, citric, lactic and sorbic acids. The new growth and growth boundary model included the inhibiting interactive effect between these factors and it was calibrated using growth curves from 10 challenge tests with unprocessed seafood. For model evaluation, 40 challenge tests with well characterized fresh and lightly preserved seafood were performed. Comparison of these observed growth curves and growth rates (µmax-values) predicted by the new model resulted in a bias factor (Bf) of 1.12 and an accuracy factor (Af) of 1.40. Furthermore, the new model was evaluated with 94 growth rates and 432 time to toxin formation data extracted from the scientific literature for seafood, poultry, meat, pasta and prepared meals. These data included responses for 36 different toxigenic strains of non-proteolytic C. botulinum. The obtained Bf-/Af-values were 0.97/2.04 for µmax-values and 0.96/1.80 for time to toxin formation. The model correctly predicted 93.8% of the growth responses with 5.6% being fail-safe and <1% fail-dangerous. A cocktail of four non-toxin producing Clostridium spp. isolates was used to develop the new model and these isolates had more than 99.8% 16S rRNA gene similarity to non-proteolytic C. botulinum (Group II). The high number of environmental factors included in the new model makes it a flexible tool to facilitate development or reformulation of seafood and poultry products that do not support the growth of non-proteolytic C. botulinum. Further, evaluation of the new model with well characterized products is desirable particularly for meat, vegetables, pasta and prepared meals as well as for dairy products that was not included in the present study.


Assuntos
Clostridium botulinum/crescimento & desenvolvimento , Animais , Toxinas Bacterianas/genética , Toxinas Bacterianas/metabolismo , Clostridium botulinum/química , Clostridium botulinum/genética , Clostridium botulinum/metabolismo , DNA Bacteriano/genética , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Cinética , Carne/microbiologia , Modelos Biológicos , RNA Ribossômico 16S/genética , Alimentos Marinhos/microbiologia , Temperatura , Verduras/microbiologia
17.
Food Microbiol ; 97: 103723, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33653532

RESUMO

The initial handling of marine fish on board fishing vessels is crucial to retain freshness and ensure an extended shelf life of the resulting fresh products. Here the effect of onboard chitosan treatment of whole, gutted Atlantic cod (Gadus morhua) was studied by evaluating the quality and shelf life of loins processed six days post-catch and packaged in air or modified atmosphere (% CO2/O2/N2: 55/5/40) and stored superchilled for 11 and 16 days, respectively. Sensory evaluation did not reveal a clear effect of chitosan treatment on sensory characteristics, length of freshness period or shelf life of loins under either packaging conditions throughout the storage period. However, directly after loin processing, microbiological analysis of loins showed that onboard chitosan treatment led to significantly lower total viable counts as well as lower counts of specific spoilage organisms (SSO), such as H2S-producers and Pseudomonas spp., compared to the untreated group. In addition, the culture-independent approach revealed a lower bacterial diversity in the chitosan-treated groups compared to the untreated groups, independently of packaging method. Partial 16S rRNA gene sequences belonging to Photobacterium dominated all sample groups, indicating that this genus was likely the main contributor to the spoilage process.


Assuntos
Bactérias/efeitos dos fármacos , Quitosana/farmacologia , Conservação de Alimentos/métodos , Conservantes de Alimentos/farmacologia , Gadus morhua/microbiologia , Alimentos Marinhos/microbiologia , Animais , Atmosfera , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Bactérias/isolamento & purificação , Temperatura Baixa , Contagem de Colônia Microbiana , Contaminação de Alimentos/análise , Contaminação de Alimentos/prevenção & controle , Conservação de Alimentos/instrumentação , Armazenamento de Alimentos , Humanos , Alimentos Marinhos/análise , Paladar
18.
Food Chem ; 355: 129610, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-33773460

RESUMO

Fish deterioration imposes great economic losses and serious human health hazards. The objective of this work was to evaluate the effect of a sodium alginate bilayer coating incorporated to the green propolis extract in shelf-life, physical-chemical properties, microbiological properties and sensory acceptance of Colossoma macropomum fillets. Additionally, the chemical composition, along with the antioxidant and antibacterial activities of Brazilian green propolis extract (GPE) were investigated. GPE showed promising antioxidant and antibacterial activities. Twenty-seven metabolites were identified by gas chromatography (GC-MS), which mainly comprised terpenoids (52.14%). Cyclolaudenol was the major constituent of the GPE and it is described for the first time in green propolis extracts. C. macropomum fillets treated with the sodium alginate bilayer coating showed high sensory acceptance, reduced microbial deterioration and extended shelf-life (up to 11 days) during cold storage. Taken together, these results show that GPE can be a great alternative of a natural preservative for fish coating.


Assuntos
Alginatos/química , Armazenamento de Alimentos/métodos , Extratos Vegetais/química , Própole/química , Alimentos Marinhos/microbiologia , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antioxidantes/química , Caraciformes , Escherichia coli/efeitos dos fármacos , Flavonoides/análise , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Concentração de Íons de Hidrogênio , Fenóis/análise , Extratos Vegetais/análise , Extratos Vegetais/farmacologia , Análise de Componente Principal , Própole/metabolismo , Alimentos Marinhos/análise , Staphylococcus aureus/efeitos dos fármacos
19.
Int J Food Microbiol ; 345: 109152, 2021 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-33725529

RESUMO

Photodynamic inactivation (PDI) is a promising method with multiple targets to inactivate bacteria on food using visible light. Inactivation potency of the curcumin-mediated blue light-emitting diode (LED) PDI against the pathogen Vibrio parahaemolyticus on cooked oysters and its effects on the storage quality were investigated by the microbiological, physical, chemical and histological methods during storage at 4 °C, 10 °C and 25 °C. Results showed that the PDI treatment obviously inhibited the recovery of V. parahaemolyticus on oysters during storage, and the maximal difference attained >1.0 Log10 CFU/g (> 90%) compared to control stored at 10 °C and 25 °C. Meanwhile, it displayed a potent ability (p < 0.05) to restrain the decrease of pH values, reduce the production of total volatile basic nitrogen (TVB-N), suppress the lipids oxidation, as well as retard the changes of color difference of the oysters. In addition, the PDI effectively maintained the integrity and initial attachments of muscle fibers, and hence decreased the loss of water in myofibrillar space and the texture softening of oysters during storage. On this basis, this study facilitates the understanding of the potency of bacterial inactivation and food preservation of PDI, and hence pave the way for its application in food industry.


Assuntos
Curcumina/farmacologia , Desinfecção/métodos , Conservação de Alimentos/métodos , Ostreidae/microbiologia , Vibrio parahaemolyticus/efeitos dos fármacos , Animais , Contagem de Colônia Microbiana , Culinária , Microbiologia de Alimentos/métodos , Armazenamento de Alimentos/métodos , Doenças Transmitidas por Alimentos/prevenção & controle , Luz , Alimentos Marinhos/microbiologia , Temperatura
20.
Food Chem ; 354: 129581, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-33756319

RESUMO

The effect of fish gelatin (FG) and grape seed extract (GSE) on microbiota composition and moisture state of fish was unexplored. Herein, this study aimed to evaluate the single and combined (FGG) effects on seabass during storage (4 °C) with assistant of vacuum impregnation and to elucidate the underlying preservative mechanism. As suggested by low-field NMR and magnetic resonance imaging, FGG-treated seabass presented higher water holding capacity by controlling transformation from immobilised to free water. Moreover, the total viable count and spoilage bacteria were reduced by > 1 log CFU/g as compared to the control. Changes in microbial flora analysed using high throughput sequencing further indicated that GSE contributed to the notably suppressed growth of Pseudomonas. Also, the accumulation of biogenic amines especially putrescine was decreased (over 0.5-fold) under the combination treatment as compared to the control (P < 0.05). The results suggest that FGG is promising for seabass preservation.


Assuntos
Bass/microbiologia , Qualidade dos Alimentos , Armazenamento de Alimentos/métodos , Gelatina/farmacologia , Extrato de Sementes de Uva/farmacologia , Vácuo , Água/análise , Animais , Embalagem de Alimentos , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota , Alimentos Marinhos/microbiologia
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