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1.
J Virol ; 98(1): e0135923, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38084959

RESUMO

Phage therapy has shown great promise for the treatment of multidrug-resistant bacterial infections. However, the lack of a thorough and organized understanding of phage-body interactions has limited its clinical application. Here, we administered different purified phages (Salmonella phage SE_SZW1, Acinetobacter phage AB_SZ6, and Pseudomonas phage PA_LZ7) intravenously to healthy animals (rats and monkeys) to evaluate the phage-induced host responses and phage pharmacokinetics with different intravenous (IV) doses in healthy animals. The plasma and the organs were sampled after different IV doses to determine the phage biodistribution, phage-induced cytokines, and antibodies. The potential side effects of phages on animals were assessed. A non-compartment model revealed that the plasma phage titer gradually decreased over time following a single dose. Repeated doses resulted in a 2-3 Log10 decline of the plasma phage titer at 5 min compared to the first dose, regardless of the type of phage administered in rats. Host innate immune responses were activated including splenic enlargement following repeated doses. Phage-specific neutralization antibodies in animals receiving phages were detected. Similar results were obtained from monkeys. In conclusion, the mammalian bodies were well-tolerant to the administered phages. The animal responses to the phages and the phage biodistribution profiles could have a significant impact on the efficacy of phage therapy.IMPORTANCEPhage therapy has demonstrated potential in addressing multidrug-resistant bacterial infections. However, an insufficient understanding of phage-host interactions has impeded its broader clinical application. In our study, specific phages were administered intravenously (IV) to both rats and monkeys to elucidate phage-host interactions and evaluate phage pharmacokinetics (PK). Results revealed that with successive IV administrations, there was a decrease in plasma phage concentrations. Concurrently, these administrations elicited both innate and adaptive immune responses in the subjects. Notably, the observed immune responses and PK profiles exhibited variation contingent upon the phage type and the mammalian host. Despite these variations, the tested mammals exhibited a favorable tolerance to the IV-administered phages. This underscores the significance of comprehending these interactions for the optimization of phage therapy outcomes.


Assuntos
Infecções Bacterianas , Bacteriófagos , Terapia por Fagos , Animais , Humanos , Ratos , Infecções Bacterianas/terapia , Bacteriófagos/fisiologia , Mamíferos , Fagos de Pseudomonas , Distribuição Tecidual , Farmacorresistência Bacteriana Múltipla
2.
Diabetes Obes Metab ; 26(5): 1789-1798, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38433711

RESUMO

AIM: The retina and brain share similar anatomical and physiological features. Thus, retinal imaging by optical coherence tomography angiography (OCTA) might be a potential tool for the early diagnosis of diabetic cerebral small vessel disease (CSVD). In this study, we aimed to evaluate retinal vascular density (VD) in diabetic CSVD by OCTA imaging and explore the associations between retinal VD and cerebral magnetic resonance imaging (MRI) markers and cognitive function. METHODS: In total, 131 patients were enrolled, including CSVD (n = 43) and non-CSVD groups (n = 88). The VD and foveal avascular zone of the retinal capillary plexus were measured with OCTA. A brain MRI was performed. RESULTS: MRI imaging showed that in the diabetic CSVD group, white matter hyperintensities (WMHs), particularly deep WMHs (58.82%), are the most common MRI marker, followed by cerebral microbleeds in the subtentorial and cortical areas (34.78%). The CSVD group showed increases in the prevalence of cognitive dysfunction (p = .034) and depression (p = .033) and decreases in visuospatial/executive ability and delayed recall ability. In the CSVD group, VDs of the macular superficial vascular plexus (32.93 ± 7.15% vs. 36.97 ± 6.59%, p = .002), intermediate capillary plexus (20.87 ± 4.30% vs. 23.08 ± 4.30%, p = .005) and deep capillary plexus (23.54 ± 5.00% vs. 26.05 ± 4.20%, p = .003) were lower than those of the non-CSVD group. Multiple linear regression analysis showed that VD of the macular superficial vascular plexus was independently associated with cerebral microbleeds. Meanwhile, VD of the macular intermediate capillary plexus was associated with white matter lacunar infarcts after adjustment. CONCLUSIONS: Diabetic CSVDs are characterized by MRI markers, including deep WMHs and cerebral microbleeds, and showed impaired cognition with decreased visuospatial/executive ability and delayed recall ability. OCTA imaging revealed a significant decrease in retinal microvascular perfusion in diabetic CSVD, which was related to MRI markers and cognitive function. OCTA might be a valuable potential measurement for the early diagnosis of CSVD.


Assuntos
Doenças de Pequenos Vasos Cerebrais , Diabetes Mellitus , Retinopatia Diabética , Humanos , Vasos Retinianos/diagnóstico por imagem , Angiofluoresceinografia/métodos , Densidade Microvascular , Retina , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Hemorragia Cerebral , Retinopatia Diabética/diagnóstico por imagem
3.
Cancer Immunol Immunother ; 72(4): 881-893, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36121452

RESUMO

BACKGROUND: Immunotherapy has largely improved clinical outcome of patients with esophageal squamous cell carcinoma (ESCC). However, a proportion of patients still fail to benefit. Thus, biomarkers predicting therapeutic resistance and underlying mechanism needs to be investigated. METHODS: Transcriptomic profiling was applied in FFPE tissues from 103 ESCC patients, including surgical samples from 66 treatment-naïve patients with long-term follow-up, and endoscopic biopsies from 37 local advanced ESCC cases receiving neoadjuvant immunotherapy plus chemotherapy. Unsupervised clustering indicated an aggressive phenotype with mesenchymal character in 66 treatment-naïve samples. Univariant logistic regression was applied to identify candidate biomarkers potentially predicted resistance to neoadjuvant immunotherapy within the range of mesenchymal phenotype enriched genes. These biomarkers were further validated by immunohistochemistry. Putative mechanisms mediating immunotherapy resistance, as indicated by microenvironment and immune cell infiltration, were evaluated by transcriptomic data, and validated by multiplex immunofluorescence. RESULTS: PLEK2 and IFI6, highly expressed in mesenchymal phenotype, were identified as novel biomarkers relating to non-MPR in neoadjuvant immunotherapy cohort [PLEK2high, OR (95% CI): 2.15 (1.07-4.33), P = 0.032; IFI6high, OR (95% CI): 2.21 (1.16-4.23), P = 0.016). PLEK2high and IFI6 high ESCC patients (versus low expressed patients) further exhibit higher chance of non-major pathological remissions (90%, P = 0.004) in neoadjuvant immunotherapy cohort and high mortality (78.9%, P = 0.05), poor prognosis in retrospective cohort. PLEK2high/IFI6high ESCC recapitulated mesenchymal phenotype, characterized by extracellular matrix composition and matrix remodeling. In addition, PLEK2high or IFI6high ESCC displayed an immune-unfavored microenvironment, represented by positive correlating with regulatory T cells, Helper 2 T cell as well as less infiltration of B cells, effector T cells and mast cells. CONCLUSIONS: PLEK2 and IFI6 was discovered of first time to identify a distinct ESCC subpopulation cannot be benefited from neoadjuvant immunotherapy and present a poor survival, which putatively associated with mesenchymal and immune-suppressive microenvironment.


Assuntos
Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Humanos , Carcinoma de Células Escamosas do Esôfago/terapia , Carcinoma de Células Escamosas do Esôfago/patologia , Estudos Retrospectivos , Terapia Neoadjuvante , Prognóstico , Biomarcadores Tumorais/genética , Imunoterapia , Microambiente Tumoral , Proteínas Mitocondriais/uso terapêutico , Proteínas de Membrana/uso terapêutico
4.
Appl Environ Microbiol ; 89(4): e0200422, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-36975809

RESUMO

Soft-ripened cheeses (SRCs) are at a higher risk for the growth of the foodborne pathogen Listeria monocytogenes due to favorable moisture content and pH compared to other cheeses. L. monocytogenes growth is not consistent across SRCs, however, and may be affected by physicochemical and/or microbiome characteristics of the cheeses. Therefore, the purpose of this study was to investigate how the physicochemical and microbiome profiles of SRCs may affect L. monocytogenes growth. Forty-three SRCs produced from raw (n = 12) or pasteurized (n = 31) milk were inoculated with L. monocytogenes (103 CFU/g), and the pathogen growth was monitored over 12 days at 8°C. In parallel, the pH, water activity (aw), microbial plate counts, and organic acid content of cheeses were measured, and the taxonomic profiles of the cheese microbiomes were measured using 16S rRNA gene targeted amplicon sequencing and shotgun metagenomic sequencing. L. monocytogenes growth differed significantly between cheeses (analysis of variance [ANOVA]; P < 0.001), with increases ranging from 0 to 5.4 log CFU (mean of 2.5 ± 1.2 log CFU), and was negatively correlated with aw. Raw milk cheeses showed significantly lower L. monocytogenes growth than pasteurized-milk cheeses (t test; P = 0.008), possibly due to an increase in microbial competition. L. monocytogenes growth in cheeses was positively correlated with the relative abundance of Streptococcus thermophilus (Spearman correlation; P < 0.0001) and negatively correlated with the relative abundances of Brevibacterium aurantiacum (Spearman correlation; P = 0.0002) and two Lactococcus spp. (Spearman correlation; P < 0.01). These results suggest that the cheese microbiome may influence the food safety in SRCs. IMPORTANCE Previous studies have identified differences in L. monocytogenes growth between SRCs, but no clear mechanism has yet been elucidated. To the best of our knowledge, this is the first study to collect a wide range of SRCs from retail sources and attempt to identify key factors associated with pathogen growth. A key finding in this research was the positive correlation between the relative abundance of S. thermophilus and the growth of L. monocytogenes. The inclusion of S. thermophilus as a starter culture is more common in industrialized SRC production, suggesting that industrial production of SRC may increase the risk of L. monocytogenes growth. Overall, the results of this study further our understanding of the impact of aw and the cheese microbiome on the growth of L. monocytogenes in SRCs, hopefully leading toward the development of SRC starter/ripening cultures that can prevent L. monocytogenes growth.


Assuntos
Queijo , Listeria monocytogenes , Microbiota , Microbiologia de Alimentos , Queijo/microbiologia , RNA Ribossômico 16S , Contagem de Colônia Microbiana
5.
Crit Rev Food Sci Nutr ; 63(15): 2598-2611, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34542350

RESUMO

One of the most significant challenges associated with postharvest apple deterioration is the blue mold caused by Penicillium expansum, which leads to considerable economic losses to apple production industries. Apple fruits are susceptible to mold infection owing to their high nutrient and water content, and current physical control methods can delay but cannot completely inhibit P. expansum growth. Biological control methods present promising alternatives; however, they are not always cost effective and have application restrictions. P. expansum infection not only enhances disease pathogenicity, but also inhibits the expression of host-related defense genes. The implementation of new ways to investigate and control P. expansum are expected with the advent of omics technology. Advances in these techniques, together with molecular biology approaches such as targeted gene deletion and whole genome sequencing, will lead to a better understanding of the P. expansum infectious machinery. Here, we review the progress of research on the blue mold disease caused by P. expansum in apples, including physiological and molecular infection mechanisms, as well as various methods to control this common plant pathogen.


Assuntos
Malus , Penicillium , Penicillium/metabolismo , Frutas , Plantas
6.
Food Microbiol ; 111: 104192, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36681391

RESUMO

Many niche-dependent barriers along the poultry production continuum favour the survival of certain Salmonella serovars over others. Historically, the presence of particular serovars has been determined by niche-specific genes which encode resistance to selective pressures such as host defenses and industrial antimicrobial practices. Over the past decade, Canada has witnessed unexplained shifts in the Salmonella landscape in the poultry sector. Several formerly minor Salmonella serovars, including S. Kentucky and S. Reading, have recently increased in prevalence in live chickens and turkeys, respectively, in British Columbia (BC). The purpose of this research was to investigate the genomic features of the top poultry-associated Salmonella spp. in BC, to probe for serovar-specific characteristics that could address the recently shifting balance of serovars along the poultry continuum. By examining the quantity and diversity of antimicrobial resistance (AMR) genes, virulence factors (VFs), Salmonella Pathogenicity Islands (SPIs), and plasmids across 50 poultry-associated S. enterica isolates using whole genome sequencing and antimicrobial resistance profiling, we have identified serovar-specific differences that likely influence niche survival. Specifically, isolates in our collection from predominantly human pathogenic serovars (S. I 4, [5], 12:i: , S. Typhimurium, and S. Enteritidis) were found to share the IncFIB(S) and IncFII(S) plasmids which carry important VFs known to aid in human host infection. Additionally, these strains held the lowest number of AMR genes, and the highest number of unique SPIs which also facilitate virulence. However, other serovars containing a greater diversity and abundance of resistance genes have been increasing across the poultry sector. S. Kentucky was found to carry unique AMR genes, VFs, SPIs, and plasmids that could bolster persistence in farm and processing environments. Overall, S. Kentucky also had comparatively high levels of intra-serovar genetic variability when compared to other prominent serovars from our collection. In addition, one of our two S. Reading isolates had high carriage of both AMR genes and VFs relative to other isolates in our collection. As the poultry-associated Salmonella landscape continues to evolve in Canada, future studies should monitor the genetic composition of prominent serovars across poultry production to maintain up-to-date risk assessments of these foodborne pathogens to consumers.


Assuntos
Aves Domésticas , Salmonella enterica , Humanos , Animais , Virulência/genética , Colúmbia Britânica , Kentucky , Galinhas , Salmonella , Fatores de Virulência/genética , Sorogrupo , Farmacorresistência Bacteriana Múltipla/genética , Antibacterianos/farmacologia
7.
J Adolesc ; 95(7): 1463-1477, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37455393

RESUMO

INTRODUCTION: Future self-continuity has been shown to have a protective effect against depression. This study aims to investigate the longitudinal relationship between future self-continuity and depression among college students, and to explore the mediating role of the presence of meaning and the moderating role of perceived social support. METHODS: We conducted two studies in China in 2022 and 2023. Study 1 was a longitudinal cross-lagged study that examined the relationship between future self-continuity and depression among 173 participants (49.13% females, Mage = 19.39, SD = 1.63). Study 2 was a cross-sectional study that explored the mediating role of the presence of meaning and the moderating role of perceived social support among 426 participants (48.59% females, Mage = 19.30, SD = 1.60). RESULTS: Study 1 showed that future self-continuity (T1) could significantly predict depression (T2), but depression (T1) could not predict future self-continuity (T2). Study 2 showed that after controlling for gender, the presence of meaning mediated the relationship between future self-continuity and depression, whereas perceived social support moderated the first half of the mediated model's pathway and the direct pathway. CONCLUSIONS: These findings suggest that enhancing the future self-continuity of college students and increasing the level of presence of meaning are effective measures for alleviating depression. Meanwhile, educators and families are called upon to provide more social support to college students.


Assuntos
Depressão , Apoio Social , Feminino , Humanos , Adulto Jovem , Adulto , Masculino , Depressão/epidemiologia , Estudos Transversais , Estudantes , China/epidemiologia
8.
Eur Radiol ; 32(3): 1983-1996, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34654966

RESUMO

OBJECTIVES: To develop and validate a preoperative CT-based nomogram combined with radiomic and clinical-radiological signatures to distinguish preinvasive lesions from pulmonary invasive lesions. METHODS: This was a retrospective, diagnostic study conducted from August 1, 2018, to May 1, 2020, at three centers. Patients with a solitary pulmonary nodule were enrolled in the GDPH center and were divided into two groups (7:3) randomly: development (n = 149) and internal validation (n = 54). The SYSMH center and the ZSLC Center formed an external validation cohort of 170 patients. The least absolute shrinkage and selection operator (LASSO) algorithm and logistic regression analysis were used to feature signatures and transform them into models. RESULTS: The study comprised 373 individuals from three independent centers (female: 225/373, 60.3%; median [IQR] age, 57.0 [48.0-65.0] years). The AUCs for the combined radiomic signature selected from the nodular area and the perinodular area were 0.93, 0.91, and 0.90 in the three cohorts. The nomogram combining the clinical and combined radiomic signatures could accurately predict interstitial invasion in patients with a solitary pulmonary nodule (AUC, 0.94, 0.90, 0.92) in the three cohorts, respectively. The radiomic nomogram outperformed any clinical or radiomic signature in terms of clinical predictive abilities, according to a decision curve analysis and the Akaike information criteria. CONCLUSIONS: This study demonstrated that a nomogram constructed by identified clinical-radiological signatures and combined radiomic signatures has the potential to precisely predict pathology invasiveness. KEY POINTS: • The radiomic signature from the perinodular area has the potential to predict pathology invasiveness of the solitary pulmonary nodule. • The new radiomic nomogram was useful in clinical decision-making associated with personalized surgical intervention and therapeutic regimen selection in patients with early-stage non-small-cell lung cancer.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Nódulo Pulmonar Solitário , Feminino , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Aprendizado de Máquina , Pessoa de Meia-Idade , Nomogramas , Estudos Retrospectivos , Nódulo Pulmonar Solitário/diagnóstico por imagem , Tomografia Computadorizada por Raios X
9.
Food Microbiol ; 102: 103915, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34809941

RESUMO

Listeria monocytogenes remains a threat to the food system and has led to numerous foodborne outbreaks worldwide. L. monocytogenes can establish itself in food production facilities by adhering to surfaces, resulting in increased resistance to environmental stressors. The aim of this study was to evaluate the adhesion ability of L. monocytogenes at 8 °C and to analyse associations between the observed phenotypes and genetic factors such as internalin A (inlA) genotypes, stress survival islet 1 (SSI-1) genotype, and clonal complex (CC). L. monocytogenes isolates (n = 184) were grown at 8 °C and 100% relative humidity for 15 days. The growth was measured by optical density at 600 nm every 24 h. Adherent cells were stained using crystal violet and quantified spectrophotometrically. Genotyping of inlA and SSI-1, multi-locus sequence typing, and a genome-wide association study (GWAS) were performed to elucidate the phenotype-genotype relationships in L. monocytogenes cold adhesion. Among all inlA genotypes, truncated inlA isolates had the highest mean adhered cells, ABS595nm = 0.30 ± 0.15 (Tukey HSD; P < 0.05), while three-codon deletion inlA isolates had the least mean adhered cells (Tukey HSD; P < 0.05). When SSI-1 was present, more cells adhered; less cells adhered when SSI-1 was absent (Welch's t-test; P < 0.05). Adhesion was associated with clonal complexes which have low clinical frequency, while reduced adhesion was associated with clonal complexes which have high frequency. The results of this study support that premature stop codons in the virulence gene inlA are associated with increased cold adhesion and that an invasion enhancing deletion in inlA is associated with decreased cold adhesion. This study also provides evidence to suggest that there is an evolutionary trade off between virulence and adhesion in L. monocytogenes. These results provide a greater understanding of L. monocytogenes adhesion which will aid in the development of strategies to reduce L. monocytogenes in the food system.


Assuntos
Aderência Bacteriana , Listeria monocytogenes , Poliestirenos , Proteínas de Bactérias/genética , Microbiologia de Alimentos , Estudos de Associação Genética , Genômica , Listeria monocytogenes/classificação , Listeria monocytogenes/genética , Tipagem de Sequências Multilocus , Mutação
10.
J Cell Physiol ; 236(5): 3963-3978, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33151569

RESUMO

Increasing evidence indicates that c-mesenchymal-epithelial transition factor (cMET) plays an important role in the malignant progression of colorectal cancer (CRC). However, the underlying mechanism is not fully understood. As a metastasis suppressor, raf kinase inhibitory protein (RKIP) loss has been reported in many cancer types. In this study, the expression levels of cMET and RKIP in CRC tissues and cell lines were determined, and their crosstalk and potential biological effects were explored in vitro and in vivo. Our results showed that cMET was inversely correlated with RKIP. Both cMET upregulation and RKIP downregulation indicated poor clinical outcomes. Moreover, the MAPK/ERK signaling pathway was implicated in the regulation of cMET and RKIP. Overexpression of cMET promoted tumor cell epithelial-mesenchymal transition, invasion, migration, and chemoresistance, whereas the effects could be efficiently inhibited by increased RKIP. Notably, small hairpin RNA-mediated cMET knockdown dramatically suppressed cell proliferation, although no RKIP-induced influence on cell growth was observed in CRC. Altogether, cMET overexpression may contribute to tumor progression by inhibiting the antioncogene RKIP, providing preclinical justification for targeting RKIP to treat cMET-induced metastasis of CRC.


Assuntos
Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Transição Epitelial-Mesenquimal , Proteína de Ligação a Fosfatidiletanolamina/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Idoso , Animais , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Neoplasias Colorretais/genética , Regulação para Baixo/genética , Transição Epitelial-Mesenquimal/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Estimativa de Kaplan-Meier , Neoplasias Hepáticas/secundário , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Pessoa de Meia-Idade , Invasividade Neoplásica , Metástase Neoplásica
11.
Crit Rev Food Sci Nutr ; 61(5): 777-787, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32274932

RESUMO

Foodborne pathogens possess the ability to develop adaptive responses to sublethal environmental stresses, leading to increased tolerance to homologous or heterologous stressing agents commonly applied during food manufacturing. This phenomenon may counteract the effectiveness of current intervention strategies to ensure food safety, thus increasing consumer risk. Foodborne pathogens encounter ethanol, a common food component and a widely used food processing agent, in a variety of niches during their life cycles. The present contribution provides an overview of the influence of adaptation to sublethal doses of ethanol on the stress tolerance of major foodborne pathogens (e.g. Salmonella enterica, Vibrio parahaemolyticus, Listeria monocytogenes, Bacillus cereus, and Cronobacter sakazakii). Fundamental studies on ethanol adaptation mechanisms with a focus on cell membrane properties, gene expression patterns, protein profiles, and mutagenic analyses are discussed. Furthermore, knowledge gaps on effective mitigation of ethanol adaptation in foodborne pathogens are identified and addressed.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes , Adaptação Fisiológica , Etanol , Inocuidade dos Alimentos
12.
Compr Rev Food Sci Food Saf ; 20(4): 4019-4048, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34057273

RESUMO

Listeria monocytogenes continues to pose a food safety risk in ready-to-eat foods, including fresh and soft/semisoft cheeses. Despite L. monocytogenes being detected regularly along the cheese production continuum, variations in cheese style and intrinsic/extrinsic factors throughout the production process (e.g., pH, water activity, and temperature) affect the potential for L. monocytogenes survival and growth. As novel preservation strategies against the growth of L. monocytogenes in susceptible cheeses, researchers have investigated the use of various biocontrol strategies, including bacteriocins and bacteriocin-producing cultures, bacteriophages, and competition with native microbiota. Bacteriocins produced by lactic acid bacteria (LAB) are of particular interest to the dairy industry since they are often effective against Gram-positive organisms such as L. monocytogenes, and because many LAB are granted Generally Regarded as Safe (GRAS) status by global food safety authorities. Similarly, bacteriophages are also considered a safe form of biocontrol since they have high specificity for their target bacterium. Both bacteriocins and bacteriophages have shown success in reducing L. monocytogenes populations in cheeses in the short term, but regrowth of surviving cells can commonly occur in the finished cheeses. Competition with native microbiota, not mediated by bacteriocin production, has also shown potential to inhibit the growth of L. monocytogenes in cheeses, but the mechanisms are still unclear. Here, we have reviewed the current knowledge on the growth of L. monocytogenes in fresh and surface-ripened soft and semisoft cheeses, as well as the various methods used for biocontrol of this common foodborne pathogen.


Assuntos
Bacteriocinas , Queijo , Lactobacillales , Listeria monocytogenes , Queijo/análise , Microbiologia de Alimentos
13.
Int J Mol Sci ; 21(5)2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32164202

RESUMO

Bacteriophages have shown promise as therapeutic alternatives to antibiotics for the control of infectious bacteria, including the human pathogen Salmonella. However, the development of effective phage-based applications requires the elucidation of key interactions between phages and target hosts, particularly since host resistance to phage is inevitable. Little is known about the alteration of host phenotypes following the development of resistance to phage. The aim of this study is to evaluate the antibiotic susceptibility and virulence of a Salmonella isolate following the development of resistance to bacteriophage SI1. We observed enhanced susceptibility to tetracycline and decreased invasion capacity in a differentiated Caco-2 intestinal cell line. Whole genome sequence analysis revealed an array of mutations, most notably, truncations in vgrG1_2, a core gene involved in Type VI secretion and mutations in the lipopolysaccharide, thereby indicating the plausible attachment site of phage SI1. These findings shed light on understanding the underlying mechanism for phage immunity within the host. Importantly, we reveal an associated genetic cost to the bacterial host with developing resistance to phages. Taken together, these results will aid in advancing strategies to delay or eliminate the development of host resistance when designing informed phage-based antimicrobials.


Assuntos
Proteínas de Bactérias/genética , Bacteriófagos/fisiologia , Intestinos/citologia , Salmonella enterica/patogenicidade , Tetraciclinas/farmacologia , Bacteriófagos/genética , Células CACO-2 , Diferenciação Celular , Aptidão Genética , Humanos , Intestinos/efeitos dos fármacos , Intestinos/microbiologia , Lipopolissacarídeos/genética , Testes de Sensibilidade Microbiana , Mutação , Salmonella enterica/genética , Salmonella enterica/virologia , Ligação Viral , Sequenciamento Completo do Genoma
14.
Zhongguo Dang Dai Er Ke Za Zhi ; 22(4): 316-322, 2020 Apr.
Artigo em Zh | MEDLINE | ID: mdl-32312368

RESUMO

OBJECTIVE: To study the value of procalcitonin (PCT) within 3 days after birth in the diagnosis of neonatal early-onset sepsis (EOS), as well as the thresholds of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. METHODS: A total of 109 neonates with a confirmed diagnosis of sepsis, 215 neonates with clinically diagnosed sepsis, and 367 neonates without sepsis were enrolled. Receiver operating characteristic (ROC) curves were plotted to determine the optimal cut-off values of PCT in the diagnosis of EOS in neonates with different gestational ages and different ages. The diagnostic value of PCT and blood culture was compared. RESULTS: In the confirmed diagnosis group, the neonates with a gestational age of <34 weeks had a significantly higher level of PCT than those with a gestational age of ≥34 weeks (P<0.05). For the neonates with a gestational age of ≥34 weeks, the optimal cut-off values of PCT in the diagnosis of EOS were 1.588 ng/mL (sensitivity 0.688, specificity 0.851) at age of <12 hours, 4.960 ng/mL (sensitivity 0.737, specificity 0.883) at age of 12 - <24 hours, 5.583 ng/mL (sensitivity 0.727, specificity 0.865) at age of 24 - <36 hours, 1.710 ng/mL (sensitivity 0.732, specificity 0.755) at age of 36 - <48 hours, 3.570 ng/mL (sensitivity 0.488, specificity 0.930) at age of 48 -<60 hours, and 3.574 ng/mL (sensitivity 0.333, specificity 0.900) at age of 60 - 72 hours. PCT had a larger area under the ROC curve in the diagnosis of EOS than blood culture within 36 hours after birth (P<0.05). CONCLUSIONS: The same criteria can be used for late preterm infants (with a gestational age of ≥34 weeks) and full-term infants, while early preterm infants (with a gestational age of <34 weeks) should be considered separately. PCT has different optimal cut-off values in the diagnosis of EOS in neonates with different ages, with a higher value than blood culture in the diagnosis of EOS within 36 hours after birth.


Assuntos
Sepse Neonatal , Biomarcadores , Calcitonina , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Pró-Calcitonina , Curva ROC
15.
Appl Environ Microbiol ; 85(19)2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31375481

RESUMO

Salmonella enterica subsp. enterica serovar Enteritidis is able to adapt to sublethal concentrations of ethanol, which subsequently induce tolerance of this pathogen to normally lethal ethanol challenges. This work aims to elucidate the underlying ethanol adaptation mechanisms of S Enteritidis by proteomic and mutagenic analyses. The global proteomic response of S Enteritidis to ethanol adaptation (5% ethanol for 1 h) was determined by isobaric tags for relative and absolute quantification (iTRAQ), and it was found that a total of 138 proteins were differentially expressed in ethanol-adapted cells compared to nonadapted cells. A total of 56 upregulated proteins were principally associated with purine metabolism and as transporters for glycine betaine, phosphate, d-alanine, thiamine, and heme, whereas 82 downregulated proteins were mainly involved in enterobactin biosynthesis and uptake, the ribosome, flagellar assembly, and virulence. Moreover, mutagenic analysis further revealed the functions of two highly upregulated proteins belonging to purine metabolism (HiuH, 5-hydroxyisourate hydrolase) and glycine betaine transport (ProX, glycine betaine-binding periplasmic protein) pathways. Deletion of either hiuH or proX resulted in the development of a stronger ethanol tolerance response, suggesting negative regulatory roles in ethanol adaptation. Collectively, this work suggests that S Enteritidis employs multiple strategies to coordinate ethanol adaptation.IMPORTANCE Stress adaptation in foodborne pathogens has been recognized as a food safety concern since it may compromise currently employed microbial intervention strategies. While adaptation to sublethal levels of ethanol is able to induce ethanol tolerance in foodborne pathogens, the molecular mechanism underlying this phenomenon is poorly characterized. Hence, global proteomic analysis and mutagenic analysis were conducted in the current work to understand the strategies employed by Salmonella enterica subsp. enterica serovar Enteritidis to respond to ethanol adaptation. It was revealed that coordinated regulation of multiple pathways involving metabolism, ABC transporters, regulators, enterobactin biosynthesis and uptake, the ribosome, flagellar assembly, and virulence was responsible for the development of ethanol adaptation response in this pathogen. Such knowledge will undoubtedly contribute to the development and implementation of more-effective food safety interventions.


Assuntos
Adaptação Fisiológica , Etanol/metabolismo , Salmonella enteritidis/genética , Salmonella enteritidis/metabolismo , Glicina , Mutagênese , Proteoma/metabolismo , Purinas/metabolismo , Estresse Fisiológico , Regulação para Cima
17.
Food Microbiol ; 83: 48-58, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31202418

RESUMO

The various stages of the cheese-making process harbor distinct bacterial communities which may influence the sensory characteristics of artisanal cheeses. The objective of this study was to investigate the microbiota from dairy farm to final cheeses along an artisanal cheese-making continuum. Environmental and food samples were collected from 21 sites, including the dairy farm, milk, cheese plant, and finished cheeses. The microbiota of these samples were analyzed using 16S rRNA amplicon sequencing, with sequences grouped into operational taxonomic units (OTUs) by phylotype at the genus level. Alpha diversity decreased from dairy farm to finished cheese. Firmicutes was the dominant phylum, ranging from 31% to 92% between the dairy farm and finished cheeses, respectively, with Proteobacteria, Actinobacteria, and Bacteroides also present (25%, 11%, and 9% overall relative abundance, respectively). Of the 37 core OTUs (>5 reads in >80% of site replicates) observed in cheese, 32 were shared with the dairy farm. Starter-related genera (i.e., Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc) represented between 69% and 98% relative abundance in final cheeses depending on style, with the remainder likely acquired from various environmental sources on the farm and during the cheese-making process.


Assuntos
Bactérias/classificação , Queijo/microbiologia , Fazendas , Microbiota/genética , Leite/microbiologia , Animais , Bactérias/isolamento & purificação , DNA Bacteriano/genética , Indústria de Laticínios , Sequenciamento de Nucleotídeos em Larga Escala , Filogenia , RNA Ribossômico 16S/genética
18.
Public Health Nurs ; 36(1): 70-78, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30569469

RESUMO

In China, community nurses do not have systematic training, and the nursing education curriculum focuses on clinical nursing both in vocational school and high school. Most nurses work at a hospital, and almost all community nurses lack systematic knowledge about community nursing. A training program for community nurses in Guangzhou City has been conducted since 2003. The training curriculum has evolved over the years, but is not standardized. This article describes research on improving community nurses' basic knowledge and practice skills. We modified the curriculum with a questionnaire and a modified Delphi method. First, 318 participating nurses and instructors were queried in December 2012. Then 22 experts modified the training program based on the results of the questionnaire and implementation since 2013. After 4 years, we followed up with the new participating nurses to evaluate the curriculum.


Assuntos
Currículo/normas , Educação em Enfermagem/métodos , Satisfação no Emprego , Adulto , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Adulto Jovem
20.
Can J Microbiol ; 64(10): 695-705, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29775543

RESUMO

Soil is an important reservoir for Listeria monocytogenes, a foodborne pathogen implicated in numerous produce-related outbreaks. Our objectives were to (i) compare the survival of L. monocytogenes among three soils, (ii) compare the native bacterial communities across these soils, and (iii) investigate relationships between L. monocytogenes survival, native bacterial communities, and soil properties. Listeria spp. populations were monitored on PALCAM agar in three soils inoculated with L. monocytogenes (∼5 × 106 CFU/g): conventionally farmed (CS), grassland transitioning to conventionally farmed (TS), and uncultivated grassland (GS). Bacterial diversity of the soils was analyzed using 16S rRNA targeted amplicon sequencing. A 2 log reduction of Listeria spp. was observed in all soils within 10 days, but at a significantly lower rate in GS (Fisher's least significant difference test; p < 0.05). Survival correlated with increased moisture and a neutral pH. GS showed the highest microbial diversity. Acidobacteria was the dominant phylum differentiating CS and TS from GS, and was negatively correlated with pH, carbon, nitrogen, and moisture. High moisture content and neutral pH are likely to increase the ability of L. monocytogenes to persist in soil. This study confirmed that native bacterial communities and short-term survival of L. monocytogenes varies across soils.


Assuntos
Listeria monocytogenes/crescimento & desenvolvimento , Microbiologia do Solo , Concentração de Íons de Hidrogênio , Listeria monocytogenes/isolamento & purificação , RNA Ribossômico 16S/genética
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