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1.
Cell Biol Toxicol ; 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33651226

RESUMO

3-Chloro-1, 2-propanediol (3-MCPD) is a food-borne toxic substance well-known for more than 40 years that is mainly associated with nephrotoxicity. A better understanding of 3-MCPD nephrotoxicity is required to devise efficacious strategies to counteract its toxicity. In the present work, the role of endoplasmic reticulum (ER) stress along with its underlying regulatory mechanism in 3-MCPD-mediated renal cytotoxicity was investigated in vivo and in vitro. Our data indicated that 3-MCPD-stimulated ER stress response evidenced by sustained activation of PERK-ATF4-p-CHOP and IRE1 branches in Sprague Dawley (SD) rats and human embryonic kidney (HEK293) cells. Moreover, ER stress-associated specific apoptotic initiator, caspase 12, was over-expressed. Blocking ER stress with its antagonist, 4-phenylbutyric acid (4-PBA), improved the morphology and function of kidney effectively. 4-PBA also increased cell viability, relieved mitochondrial vacuolation, and inhibited cell apoptosis through regulating caspase-dependent intrinsic apoptosis pathways. Furthermore, the enhanced expressions of two mitochondrial fission proteins, DRP1/p-DRP1 and FIS1, and the relocation of DRP1 on mitochondria subjected to 3-MPCD were reversed by 4-PBA, while the expression of the fusion protein, MFN2, was restored. Moreover, cellular Ca2+ overload, the over-expression of CaMKK2, and the loss of mitochondria-associated membranes (MAM) were also relieved after 4-PBA co-treatment. Collectively, our data emphasized that ER stress plays critical role in 3-MCPD-mediated mitochondrial dysfunction and subsequent apoptosis as well as blockage of ER stress ameliorated kidney injury through improving mitochondrial fission/fusion and Ca2+ homeostasis. These findings provide a novel insight into the regulatory role of ER stress in 3-MCPD-associated nephropathy and a potential therapeutic strategy. Graphical Headlights 1. 4-PBA inhibits ER stress mainly through regulating PERK-ATF4-CHOP and IRE1-XBP1s branches. 2. Inhibition of ER stress by 4-PBA mitigates ER associated and mitochondrial apoptosis 3. Inhibition of ER stress by 4-PBA helps maintaining calcium homeostasis and mitochondrial dynamic.

2.
Food Chem Toxicol ; 150: 112055, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33577942

RESUMO

Patulin (PAT) is a kind of mycotoxins that commonly found in decayed fruits and their products. Our previous studies have shown that PAT induced cell apoptosis and the overproduction of reactive oxygen species (ROS) in human embryonic kidney (HEK293) cells. The present study aimed to further investigate the functional role of NADPH oxidase, one of the main cellular sources of ROS, in PAT-induced apoptosis and oxidative damage in HEK293 cells. We demonstrated that the protein and mRNA expression levels of NADPH oxidase catalytic subunit NOX2 and regulatory subunit p47phox were up-regulated under PAT stress. Inhibiting of NADPH oxidase with the specific antagonist diphenyleneiodonium (DPI) suppressed cytotoxicity and apoptosis induced by PAT as evidenced by the increase of cell viability, the decrease of LDH release and the inhibition of caspase activities. Furthermore, DPI re-established mitochondrial membrane potential (MMP) and enhanced cellular ATP content. Importantly, DPI supplementation elevated endogenous GSH contents as well as the ratio of GSH/GSSG. Meanwhile, the antioxidant-enzyme activities of GPx, GR, CAT and SOD were significantly promoted. Collectively, our results suggested that NADPH oxidase played a critical role in PAT-induced nephrotoxicity, and inhibition of NADPH oxidase by DPI attenuated cell injury and apoptosis via regulation of oxidative damage.

3.
Crit Rev Food Sci Nutr ; : 1-26, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33455435

RESUMO

Diets impact host health in multiple ways and an unbalanced diet could contribute to the initiation or progression of a variety of diseases. Although a wealth of information exists on the connections between diet and chronic metabolic diseases such as cardiovascular disease, diabetes mellitus, etc., how diet influences enteric infectious disease still remain underexplored. The review summarizes the current findings on the link between various dietary components and diverse enteric infectious diseases. Dietary ingredients discussed include macronutrients (carbohydrates, lipids, proteins), micronutrients (vitamins, minerals), and other dietary ingredients (phytonutrients and probiotic supplements). We first describe the importance of enteric infectious diseases and the direct and indirect relationship between diet and enteric infectious diseases. Then we discuss the effects of different dietary components on the susceptibility to or progression of enteric infectious disease. Finally, we delineate current knowledge gap and highlighted future research directions. The literature review revealed that different dietary components affect host resistance to enteric infections through a variety of mechanisms. Dietary components may directly inhibit or bind to enteric pathogens, or indirectly influence enteric infections through modulating immune function and gut microbiota. Elucidating the unique repercussions of different diets on enteric infections in this review may help provide dietary guidelines or design dietary interventions to prevent or alleviate enteric infectious diseases.

4.
Mol Nutr Food Res ; 65(4): e2001031, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33369197

RESUMO

SCOPE: Punicalagin (PU)-rich pomegranate peel extract has been shown before to exert protective effects against high fat-induced hepatic damage. The aim of this study is to explore whether and how PU antagonizes hepatic steatosis in Western diet-fed (WD) mice. METHODS AND RESULTS: Mice are fed either chow diet, WD (containing 42% fat, 15% protein, and 43% carbohydrates), or WD supplemented with PU (50 mg kg-1 body weight/day) for 13 weeks. Weight gain, hepatic fat content, and inflammation in the liver and adipose tissues are measured. Compared to the WD group, PU-treated mice have lower fat content, decreased levels of alanine transaminase, and inflammation in liver. PU also changed the transcriptional expression of important genes in fatty acid oxidation pathway and alleviated glucose intolerance. Furthermore, PU improved adiponectin signaling and lipid metabolism in visceral adipose tissue. Moreover, PU improved gut microbiota dysbiosis induced by WD and enhanced gut barrier function. CONCLUSIONS: The findings suggest that PU improves hepatic steatosis induced by WD, in part through regulating lipid homeostasis and inflammation in liver and adipose tissue and restoring microbiota shift and impaired gut barrier function. Thus, PU can be potentially developed as a potential prevention strategy in combating nonalcoholic fatty liver disease.

5.
Foodborne Pathog Dis ; 2020 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-33121277

RESUMO

Bacillus cereus spores are concerns for food spoilage and foodborne disease in food industry due to their high resistance to heat and various disinfectants. The aim of this study was to investigate the inactivation of B. cereus spores by slightly acidic electrolyzed water (SAEW) in comparison to sodium hypochlorite (NaClO) with same available chlorine content (ACC). In this study, the efficacy of SAEW with different concentrations of ACC (40, 60, 80, 100, and 120 mg/L) on the inactivation of B. cereus spores, and the effect of SAEW combined with mild heat treatment (60°C), was examined in pure culture suspensions. Heat resistance and pyridine-2,6-dicarboxylic acid (DPA) release of the spores were also determined. The results showed that the sporicidal effect of the SAEW was significantly higher compared with the NaClO with the same concentration of ACC. Furthermore, the inactivation efficacy was largely dependent on ACC and treatment time. Moreover, the sporicidal activity of the SAEW was significantly improved when combined with a mild heat treatment (60°C). The majority of the DPA was released from spores, and the spores exhibited less resistance to heat after SAEW treatment for 30 min. These findings indicate that SAEW could effectively inactivate B. cereus spores, making it a promising and environmentally friendly decontamination technology for application in the food industry.

6.
Virus Res ; 289: 198147, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32866537

RESUMO

BACKGROUND: To investigate the clinical significance, viral shedding duration and viral load dynamics of positive fecal SARS-CoV-2 signals in COVID-19. METHODS: COVID-19 patients were included. SARS-CoV-2 RNA was tested in stool and respiratory specimens until two sequential negative results were obtained. Clinical, laboratory and imaging data were recorded. RESULTS: Of the 69 COVID-19 patients, 20 (28.99 %) had positive fecal viral tests who were younger, had lower C-reactive protein (CRP) and fibrinogen (FIB) levels on admission (all P < 0.05), and showed more improvement and less progression on chest CT during recovery. The median duration of positive viral signals was significantly longer in stool samples than in respiratory samples (P < 0.05). In spite of the negative oropharyngeal swabs, eleven patients were tested positive for viral RNA in stool specimens, with their fecal SARS-CoV-2 RNA Ct (cycle threshold) values reaching 25-27. 6 of these 11 patients' Ct values rebounded. CONCLUSION: SARS-CoV-2 RNA in stool specimens was associated with a milder condition and better recovery of chest CT results while the median duration of SARS-CoV-2 RNA persistence was significantly longer in fecal samples than in oropharyngeal swabs. The fecal viral load easily reached a high level and rebounded even though respiratory signals became negative.


Assuntos
Betacoronavirus/isolamento & purificação , Infecções por Coronavirus/virologia , Fezes/virologia , Pneumonia Viral/virologia , RNA Viral/análise , Eliminação de Partículas Virais , Adulto , Proteína C-Reativa/análise , Infecções por Coronavirus/sangue , Infecções por Coronavirus/diagnóstico por imagem , Infecções por Coronavirus/transmissão , Diarreia/etiologia , Diarreia/virologia , Reações Falso-Negativas , Feminino , Fibrinogênio/análise , Humanos , Pulmão/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Orofaringe/virologia , Pandemias , Pneumonia Viral/sangue , Pneumonia Viral/diagnóstico por imagem , Pneumonia Viral/transmissão , Prognóstico , Estabilidade de RNA , Reação em Cadeia da Polimerase em Tempo Real , Avaliação de Sintomas , Carga Viral
7.
Food Chem Toxicol ; 145: 111740, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32910998

RESUMO

3-chlorpropane-1,2-diol (3-MCPD) is a heat-induced food process contaminant that threatens human health. As the primary target organ, the morphological and functional impairment of kidney and the related mechanism such as apoptosis and mitochondrial dysfunction were observed. However, the precise molecular mechanism remains largely unclear. This study aimed to explore the important role of mitochondrial fission and autophagy in the 3-MCPD-caused apoptosis of human embryonic kidney 293 (HEK293) cells. The results showed that blockage of dynamin-related protein-1 (Drp1) by mitochondrial division inhibitor 1 (Mdivi-1, 15 µM) apparently restored 3-MCPD-induced mitochondrial dysfunction, accompanied by prevented the collapse of mitochondrial membrane potential and ATP depletion, and suppressed the occurrence of autophagy. Induction of autophagy occurred following 2.5-10 mM 3-MCPD treatment for 24 h via AMPK mediated mTOR signaling pathway. Meanwhile, enhancement of autophagy by pretreatment with rapamycin (1 nM) alleviated the loss of cell viability and apoptosis induced by 3-MCPD whereas suppression of autophagy by 3-methyladenine (1 mM) further accelerated apoptosis, which was modulated through the mitochondria-dependent apoptotic pathway. Taking together, this study provides novel insights into the 3-MCPD-induced apoptosis in HEK293 cells and reveals that autophagy has potential as an effective intervention strategy for the treatment of 3-MCPD-induced nephrotoxicity.

8.
Fish Shellfish Immunol ; 106: 431-440, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32810530

RESUMO

The extensive use of antibiotics in aquaculture has resulted in the prevalence of antibiotic-resistant bacteria and, consequently, new antibacterial strategies or drugs with clear modes of action are urgently needed. Antimicrobial peptides (AMPs) are currently widely considered as alternatives to antibiotics in the treatment of infections in aquatic animals. In this study, we aimed to evaluate the effects of NKL-24, a truncated peptide derived from zebrafish NK-lysin, against Yesso scallop (Patinopecten yessoensis) pathogen, Vibrio parahaemolyticus. The results showed that NKL-24 had a potent antibacterial effect against V. parahaemolyticus via a membrane active cell-killing mechanism. The in vitro study showed that sub-lethal levels of NKL-24 obviously reduced bacterial swimming ability and downregulated the transcription of the selected genes associated with V. parahaemolyticus virulence. Studies on NKL-24 biosafety in hemocytes and in Yesso scallop have shown no adverse effects from this peptide. Bacteria challenge test results demonstrated that NKL-24 significantly decreased the mortality and inhibited bacterial growth in the scallop infected with V. parahaemolyticus, while further in vivo examination revealed that NKL-24 could enhance non-specific immune parameters. Moreover, NKL-24 was capable of modulating a series of V. parahaemolyticus-responsive genes in the scallop. These results suggest the protective action of NKL-24 against V. parahaemolyticus and the potential of this peptide as a promising candidate for aquaculture applications.

9.
Food Funct ; 11(9): 7456-7467, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32789347

RESUMO

Aristolochic acid I (AA-I) remains a leading cause of aristolochic acid nephropathy (AAN), however few prevention and treatment strategies exist. In this work, the nephroprotective effect of diosgenin, a steroidal saponin distributed abundantly in several plants, on AA-I-induced renal injury and its underlying mechanism were investigated. Sprague-Dawley rats were intragastrically administered with 30 mg kg-1 d-1 diosgenin two hours before exposure to 10 mg kg-1 d-1 AA-I for consecutive four weeks, and the histological change, the renal and liver function, apoptosis, autophagy and the involved pathways were investigated. The results showed that diosgenin relieved AA-I-induced renal histological damage, including mild edematous disorder of renal tubular arrangement and widening of renal tubular lumen. No obvious changes in the hepatic tissue structure were observed in all treatment groups. Moreover, diosgenin up-regulated the expression of Bcl-2 and down-regulated Bax, and subsequently inhibited AIF expression and the cleaved form of Caspase-3, thereby alleviating apoptosis triggered by AA-I. Diosgenin also mitigated AA-I-induced renal mitochondrial dynamics disorder by increasing the expression of mitochondrial dynamics-related proteins including DRP1 and MFN2. Diosgenin inhibited AA-I-evoked autophagy via ULK1-mediated inhibition of the mTOR pathway. Overall, these results suggest that diosgenin has a protective effect against AA-I-induced renal damage and it may be a potential agent for preventing AA-I-induced AAN.

10.
J Agric Food Chem ; 68(33): 8836-8846, 2020 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-32687348

RESUMO

The ingestion of excessive free fatty acid could induce lipotoxicity in tissues and then lead to the initiation of many metabolism diseases. In this work, the protective effect of apigenin on palmitate-induced lipotoxicity in human aortic endothelial cells (HAEC) was investigated. Compared with 150 µM palmitate treatment alone, pretreatment with 10 µM apigenin for 6 h significantly increased the cell viability from 71.55 ± 3.62 to 91.06 ± 4.30% and improved mitochondrial membrane potential to the normal level (101.62 ± 11.72% of control). In addition, the production of nitric oxide was markedly elevated by apigenin cotreatment from 7.10 ± 3.95 to 94.20 ± 21.86%. The data-independent acquisition-based proteomic approach was used to study the protective mechanism, and the results revealed that 242 proteins were differently expressed in cells treated with palmitate and 93 proteins were reversed after apigenin supplementation. Apigenin realized its protective function mainly via regulating pathways such as IL-17, TNF, Fox O, cell adhesion, and endoplasmic reticulum protein processing. Collectively, these data demonstrated that apigenin supplement may serve as an alternative nutritional intervention to protect HAEC against lipotoxicity.

11.
J Food Prot ; 83(12): 2102-2106, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663262

RESUMO

Salmonella, a bacterial foodborne pathogen, can contaminate meat, milk, and vegetables. While appropriate measures are available to control Salmonella, the inhibitory phytochemicals from plants are gaining increased attention. Punicalagin, a natural antimicrobial, is one of the main active tannins isolated from Punica granatum L. To obtain a broader understanding of the effect of punicalagin on the cell membranes of Salmonella Typhimurium, the growth curves, extracellular potassium concentration, release of cell constituents, intracellular pH, membrane potential, and morphological features were characterized to elucidate the mechanisms of action. Treatment with punicalagin induced an increase in the extracellular concentrations of potassium and a release of cell constituents. A higher pH gradient, an increase in the intracellular pH, and cell membrane depolarization were observed after punicalagin treatment. Electron microscopy observations showed that the cell membrane structures of Salmonella Typhimurium were damaged by punicalagin. It is concluded that punicalagin inhibits the proliferation of Salmonella Typhimurium and destroys the integrity of the cell membrane, leading to a loss of cell homeostasis. These findings indicate that punicalagin has the potential to be developed as a future alternative to control Salmonella Typhimurium contamination in foods and reduce the risk of salmonellosis.

12.
Food Funct ; 11(7): 6158-6169, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32578655

RESUMO

Recurrent obesity is rapidly emerging as a public health problem. Previous studies have confirmed that fish oil supplementation can alleviate obesity in mice; however, the effect of fish oil on recurrent obesity remains unclear. In the present study, the modulatory effects of fish oil extracted from Coregonus peled on the phenotypes and gut microbiota of recurrent obese mice were evaluated by MRI, OGTT, and bioinformatics analysis. We found that fish oil supplementation could significantly reduce the body weight gain, net weight gain, body fat distribution, and glucose tolerance. In addition, the composition and structure of gut microbiota were significantly shifted toward those of the control group by fish oil treatment. Moreover, the relative abundance of gut microbiota, such as Bacteroidetes, Bacteroidia, Lachnospiraceae, and Bifidobacterium, was markedly responding to the rapid dietary changes between fish oil and high-fat diet. Overall, our results confirmed that the alleviation of recurrent obesity using fish oil supplementation might be modulated by altering the hysteretic behavior and memory-like function of gut microbiota. We proposed that further studies are needed to elucidate the modulation mechanism.

13.
Artigo em Inglês | MEDLINE | ID: mdl-32366706

RESUMO

Florfenicol belongs to a class of phenicol antimicrobials widely used as feed additives and for the treatment of respiratory infections. In recent years, increasing resistance to florfenicol has been reported in Campylobacter spp., the leading foodborne enteric pathogens causing diarrheal diseases worldwide. Here, we reported the identification of fexA, a novel mobile florfenicol resistance gene in Campylobacter Of the 100 Campylobacter jejuni strains isolated from poultry in Zhejiang, China, 9 were shown to be fexA positive, and their whole-genome sequences were further determined by integration of Illumina short-read and MinION long-read sequencing. The fexA gene was found in the plasmid of one strain and chromosomes of eight strains, and its location was verified by S1 nuclease pulsed-field gel electrophoresis (S1-PFGE) and Southern blotting. Based on comparative analysis, the fexA gene was located within a region with the tet(L)-fexA-catA-tet(O) gene arrangement, demonstrated to be successfully transferable among C. jejuni strains. Functional cloning indicated that acquisition of the single fexA gene significantly increased resistance to florfenicol, whereas its inactivation resulted in increased susceptibility to florfenicol in Campylobacter Taken together, these results indicated that the emerging fexA resistance is horizontally transferable, which might greatly facilitate the adaptation of Campylobacter in food production environments where florfenicols are frequently used.

14.
Food Funct ; 11(4): 3432-3440, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32236173

RESUMO

Promoting cholesterol efflux from foam cells represents one of the therapeutic strategies for ameliorating atherosclerosis. Urolithin A (UA) has been shown before to attenuate ox-LDL induced endothelial dysfunction in endothelial cells with its anti-inflammatory properties. The aim of this study was to investigate whether UA could promote cholesterol efflux via modulating related microRNA (miR) and signaling pathways. RAW264.7 cells were treated with 50 µg mL-1 ox-LDL to induce foam cell formation. After treatment with UA at different concentrations, intercellular and extracellular cholesterol levels were determined. Expression of Erk1/2, AMPKα and their phosphorylation forms, and SREBP1, was analyzed by western-blotting. The effect of UA on miR-33a expression and the involvement of miR-33a in cholesterol efflux regulation were also investigated. UA reduced ox-LDL induced cholesterol accumulation in macrophage cells and promoted cholesterol efflux from cells. Compared with ox-LDL treated cells, UA treatment reduced the level of phosphorylated ERK1/2, increased the expression of phosphorylated AMPKα and decreased the SREBP1 expression. Moreover, UA decreased the miR-33a expression at the transcriptional level but increased the transcriptional expression of ATP-binding cassette transporter A1 (ABCA1) and ABCG1, two genes contributing to reverse cholesterol transport. Furthermore, pre-miR-33a attenuated cholesterol efflux induced by UA. Collectively, UA promoted the reverse cholesterol transport in macrophage-derived foam cells and interfered with cholesterol metabolism possibly through regulating the miRNA-33 expression and interaction with the ERK/AMPKα/SREBP1 signaling pathway.

15.
Adv Biosyst ; 4(3): e1900219, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32293141

RESUMO

Colistin acts as a last-resort antibiotic against lethal infections by carbapenem-resistant Enterobacterial pathogens. Enterobacteriaceae carrying mobile colistin resistance (MCR) genes are rapidly emerging and threatening human health and food safety. Despite mcr-1 being prevalent in Escherichia coli, its dissemination in Salmonella is not well characterized. Herein, two unusual serotypes of colistin-resistant Salmonella isolates are reported first, namely serotype Ngor (ST5399) and Goldcoast (ST2529). Using whole genome sequencing, it is shown that mcr-1 is located on the IncHI2-like plasmid pTB501 (188,527 bp) of strain SSDFZ54 and the IncX4-type plasmid pTB602 (33,303 bp) in strain SSDFZ69, respectively. Furthermore, the backbone, tra- and antimicrobial resistance genes relative variable regions in the mcr-1-bearing IncHI2 plasmids are systematically characterized. Phylogenetic analysis shows that all IncHI2-type plasmids from non-Chinese regions are clustered together, suggesting a possible Chinese origin. Taken together, these findings extend the understanding of Salmonella as a vehicle of mcr-1 carriage and distribution.

16.
J Food Prot ; 83(8): 1402-1410, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32294180

RESUMO

ABSTRACT: Colistin is used as one of the last-resort drugs against lethal infections caused by carbapenem-resistant pathogens of the Enterobacteriaceae family. Enterobacteriaceae bacteria carrying the mcr-1 colistin resistance gene are emerging in livestock and poultry, posing a serious threat to human health. However, there have been few reports about the prevalence and transmission of mcr-1 along the regional chicken supply chain. In this study, the complete sequences of mcr-1-positive Escherichia coli ST2705 and ST206 isolates obtained by screening 129 chilled chicken samples and 251 chicken fecal samples were investigated. Both of these isolates showed resistance to colistin, and importantly, the complete sequence of the mcr-1-positive E. coli ST2705 in China was reported for the first time. The mcr-1 gene was located on the IncHI2 plasmids pTBMCR421 (254,365 bp) and pTBMCR401 (230,964 bp) in strains ECCNB20-2 and ECZP248, respectively. Comparative analysis of mcr-1-bearing IncHI2 plasmids showed a marked similarity, indicating that these plasmids are very common and have the ability to be efficient vehicles for mcr-1 dissemination among humans, animals, and food. Furthermore, an insertion (ISKpn26) in Tn6330 (ISApl1-mcr-1-pap2-ISApl1) was identified in the plasmid pTBMCR401 and then compared; this insertion might affect the adaptability and stability of Tn6330. Taken together, these findings suggest that the IncHI2 plasmid might be a main factor affecting the transmission of mcr-1 in the chicken supply chain and that the genetic context of the mcr-1-bearing IncHI2 plasmid is constantly evolving.

17.
Microbiol Res ; 235: 126448, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32114363

RESUMO

Vibrio parahaemolyticus is a common foodborne pathogen in seafood and represents a major threat to human health worldwide. In this study, we identified that PhoR, a histidine kinase, is involved in the regulation of swarming and flagella assembly. RNA sequencing analysis showed that 1122 genes were differentially expressed in PhoR mutant, including 394 upregulated and 728 downregulated genes. KEGG enrichment and heatmap analysis demonstrated that the bacterial secretion system, flagella assembly and chemotaxis pathways were significantly downregulated in PhoR mutant, while the microbial metabolism in diverse environments and carbon metabolism pathways were upregulated in PhoR mutant. qRT-PCR further confirmed that genes responsible for the type III secretion system (T3SS), swarming and the thermostable direct hemolysin were positively regulated by PhoR. Phosphorylation assays suggested that PhoR was highly activated in BHI medium compared to LB medium. Taken together, these data suggested that activated PhoR contributes to the expression of swarming motility and secretion system genes in Vibrio parahaemolyticus.


Assuntos
Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Transcriptoma , Sistemas de Secreção Tipo III/genética , Vibrio parahaemolyticus/genética , Toxinas Bacterianas/genética , Biofilmes/crescimento & desenvolvimento , Regulação para Baixo , Perfilação da Expressão Gênica , Proteínas Hemolisinas/genética , Movimento , Regulação para Cima , Vibrio parahaemolyticus/enzimologia
18.
Appl Environ Microbiol ; 86(10)2020 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-32169938

RESUMO

Biofilm formation by Pseudomonas aeruginosa contributes to its survival on surfaces and represents a major clinical threat because of the increased tolerance of biofilms to disinfecting agents. This study aimed to investigate the efficacy of 405-nm light-emitting diode (LED) illumination in eliminating P. aeruginosa biofilms formed on stainless steel coupons under different temperatures. Time-dependent killing assays using planktonic and biofilm cells were used to determine the antimicrobial and antibiofilm activities of LED illumination. We also evaluated the effects of LED illumination on the disinfectant susceptibility, biofilm structure, extracellular polymeric substance (EPS) structure and composition, and biofilm-related gene expression of P. aeruginosa biofilm cells. Results showed that the abundance of planktonic P. aeruginosa cells was reduced by 0.88, 0.53, and 0.85 log CFU/ml following LED treatment for 2 h compared with untreated controls at 4, 10, and 25°C, respectively. For cells in biofilms, significant reductions (1.73, 1.59, and 1.68 log CFU/cm2) were observed following LED illumination for 2 h at 4, 10, and 25°C, respectively. Moreover, illuminated P. aeruginosa biofilm cells were more sensitive to benzalkonium chloride or chlorhexidine than untreated cells. Scanning electron microscopy and confocal laser scanning microscopic observation indicated that both the biofilm structure and EPS structure were disrupted by LED illumination. Further, reverse transcription-quantitative PCR revealed that LED illumination downregulated the transcription of several genes associated with biofilm formation. These findings suggest that LED illumination has the potential to be developed as an alternative method for prevention and control of P. aeruginosa biofilm contamination.IMPORTANCE Pseudomonas aeruginosa can form biofilms on medical implants, industrial equipment, and domestic surfaces, contributing to high morbidity and mortality rates. This study examined the antibiofilm activity of 405-nm light-emitting diode (LED) illumination against mature biofilms formed on stainless steel coupons. We found that the disinfectant susceptibility, biofilm structure, and extracellular polymeric substance structure and composition were disrupted by LED illumination. We then investigated the transcription of several critical P. aeruginosa biofilm-related genes and analyzed the effect of illumination temperature on the above characteristics. Our results confirmed that LED illumination could be developed into an effective and safe method to counter P. aeruginosa biofilm contamination. Further research will be focused on the efficacy and application of LED illumination for elimination of complicated biofilms in the environment.


Assuntos
Biofilmes/efeitos da radiação , Desinfecção/métodos , Luz , Pseudomonas aeruginosa/efeitos da radiação , Aço Inoxidável , Iluminação , Pseudomonas aeruginosa/fisiologia , Temperatura
19.
Microbiol Resour Announc ; 9(6)2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32029565

RESUMO

Here, we report the complete genome sequence of colistin-resistant Escherichia fergusonii strain EFCF056, isolated from chicken feces. This genome contains six plasmids, including a 204,246-bp plasmid harboring the colistin resistance gene mcr-1 These results will increase our understanding of plasmid-mediated mcr-1 gene presence and transmission in E. fergusonii.

20.
Foodborne Pathog Dis ; 17(4): 243-252, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31702399

RESUMO

Necrotizing enterocolitis (NEC) is a serious inflammatory intestinal disorder with a high mortality rate, which occurs most commonly in newborn infants. Cronobacter sakazakii, a common contaminant in infant formula, is associated with NEC. However, its role in NEC pathogenesis is unknown, and there are still no effective treatments for NEC. Currently, natural bioactive products have been investigated for their beneficial effects in preventing microbial infection. In this study, a neonatal mouse intestinal inflammation model was used to examine the protective effects of citral (a natural bioactive product) on C. sakazakii-induced intestinal inflammation and damages. It was shown that citral reduced the number of C. sakazakii cells in ileal tissues, and mice treated with citral had a significantly higher body weight than C. sakazakii-infected mice. Citral treatment also ameliorated serious ileal tissue damages, including epithelial sloughing, villous rupture, and enterocyte apoptosis. C. sakazakii infection upregulated the messenger RNA transcription levels of several inflammation-associated genes, increased production of IL-6 and TNF-α, and activated the NF-κB and MAPK signaling pathways in ileal tissues. Citral treatment mitigated these inflammatory responses. The apoptotic index and activities of caspase 3, 8, and 9 increased in murine ileum after C. sakazakii infection, but citral inhibited both enterocyte apoptosis and activations of these caspase. These findings suggest that citral has protective effects on C. sakazakii-induced intestinal inflammation in newborn mice, and it may play a future role in the management of C. sakazakii-associated infections and diseases.

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