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1.
Artigo em Francês | MEDLINE | ID: mdl-38874186

RESUMO

The geriatric failure to thrive, a controversial French concept not present in the international literature, was first characterized by Jean Carrié in 1956. It is described as a process of aging and physical and psychological decline associated with advanced age, manifesting as a pronounced overall deterioration. In this case report, we present the case of an 88-year-old patient, admitted to a general medicine service for geriatric failure to thrive, whose management eventually leads to the diagnosis of endocarditis with digestive cancer complicated by a characterized depressive episode. This case prompts us to consider the geriatric failure to thrive with extreme caution and challenges the legitimacy of such a diagnosis in the context of an aging population and the progress of medical sciences.

2.
Vaccine ; 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38806353

RESUMO

Small ruminants affected by brucellosis, caused mainly by Brucella melitensis and B. ovis, suffer reproductive disorders, leading to significant economic losses worldwide. Vaccination is an essential tool to prevent the disease in ovine and caprine livestock, but the only vaccine recommended to date is B. melitensis Rev1, which in sheep is only safe for use in lambs aged 3-4 months. This restriction poses considerable practical challenges for the implementation of Rev1 in countries with endemic brucellosis and/or limited resources, where there is a need for mass vaccination with a safe vaccine to control the disease in both animals and humans. We recently developed a B. melitensis strain Rev1Δwzm showing superior vaccine properties in mice and safety in pregnant ewes. Here, we report that Rev1Δwzm (i) is safe in young and adult sheep, both male and female; (ii) induces a transient serological response in the Rose Bengal test in ≤50 % of sheep, confirmed to some extent by the complement fixation test, and a stronger, more persistent anti- rough-LPS response; and (iii) protects rams against a B. ovis challenge 25 weeks after vaccination. To resolve the problem of serological interference, the use of green fluorescent protein tagging strategy allowed us to identify vaccinated sheep with only a single inoculation. These results, together with the previously reported safety in pregnant ewes, position Rev1Δwzm as a firm vaccine candidate and a promising alternative to Rev1. Further experiments are warranted to assess its efficacy against B. melitensis in pregnant ewes.

3.
Acta Haematol ; 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38359806

RESUMO

Introduction Immunocompromised patients can show prolonged shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and persistent symptoms, which is called persistent COVID-19. Case presentation We report a case of an immunocompromised patient who was treated for mantle cell lymphoma and was suffering from B-cell depletion. The patient developed persistent COVID-19, which was confirmed by real-time polymerase chain reaction (RT-PCR) tests in only sputum and bronchoalveolar fluid which remained positive for at least 112 days. The patient was successfully treated with SARS-CoV-2 convalescent plasma. Conclusion It could be of interest to investigate the RT-PCR results of SARS-CoV-2 in sputum/bronchoalveolar lavage samples from immunocompromised patients with unexplained pneumonia.

5.
Front Immunol ; 14: 1185716, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37304271

RESUMO

Background: Tocilizumab and anakinra are anti-interleukin drugs to treat severe coronavirus disease 2019 (COVID-19) refractory to corticosteroids. However, no studies compared the efficacy of tocilizumab versus anakinra to guide the choice of the therapy in clinical practice. We aimed to compare the outcomes of COVID-19 patients treated with tocilizumab or anakinra. Methods: Our retrospective study was conducted in three French university hospitals between February 2021 and February 2022 and included all the consecutive hospitalized patients with a laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection assessed by RT-PCR who were treated with tocilizumab or anakinra. A propensity score matching was performed to minimize confounding effects due to the non-random allocation. Results: Among 235 patients (mean age, 72 years; 60.9% of male patients), the 28-day mortality (29.4% vs. 31.2%, p = 0.76), the in-hospital mortality (31.7% vs. 33.0%, p = 0.83), the high-flow oxygen requirement (17.5% vs. 18.3%, p = 0.86), the intensive care unit admission rate (30.8% vs. 22.2%, p = 0.30), and the mechanical ventilation rate (15.4% vs. 11.1%, p = 0.50) were similar in patients receiving tocilizumab and those receiving anakinra. After propensity score matching, the 28-day mortality (29.1% vs. 30.4%, p = 1) and the rate of high-flow oxygen requirement (10.1% vs. 21.5%, p = 0.081) did not differ between patients receiving tocilizumab or anakinra. Secondary infection rates were similar between the tocilizumab and anakinra groups (6.3% vs. 9.2%, p = 0.44). Conclusion: Our study showed comparable efficacy and safety profiles of tocilizumab and anakinra to treat severe COVID-19.


Assuntos
COVID-19 , Humanos , Masculino , Idoso , SARS-CoV-2 , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Pontuação de Propensão , Estudos Retrospectivos , Tratamento Farmacológico da COVID-19 , Oxigênio
7.
Nat Biotechnol ; 41(8): 1089-1098, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36658340

RESUMO

Engineered live bacteria could provide a new modality for treating lung infections, a major cause of mortality worldwide. In the present study, we engineered a genome-reduced human lung bacterium, Mycoplasma pneumoniae, to treat ventilator-associated pneumonia, a disease with high hospital mortality when associated with Pseudomonas aeruginosa biofilms. After validating the biosafety of an attenuated M. pneumoniae chassis in mice, we introduced four transgenes into the chromosome by transposition to implement bactericidal and biofilm degradation activities. We show that this engineered strain has high efficacy against an acute P. aeruginosa lung infection in a mouse model. In addition, we demonstrated that the engineered strain could dissolve biofilms formed in endotracheal tubes of patients with ventilator-associated pneumonia and be combined with antibiotics targeting the peptidoglycan layer to increase efficacy against Gram-positive and Gram-negative bacteria. We expect our M. pneumoniae-engineered strain to be able to treat biofilm-associated infections in the respiratory tract.


Assuntos
Pneumonia Associada à Ventilação Mecânica , Infecções por Pseudomonas , Humanos , Camundongos , Animais , Antibacterianos/uso terapêutico , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Pneumonia Associada à Ventilação Mecânica/microbiologia , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Intubação Intratraqueal , Biofilmes , Pulmão
8.
Arch Bronconeumol ; 59(1): 27-35, 2023 Jan.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36273933

RESUMO

Pleural effusion (PE) is a common yet complex disease that requires specialized, multidisciplinary management. Recent advances, novel diagnostic techniques, and innovative patient-centered therapeutic proposals have prompted an update of the current guidelines. This document provides recommendations and protocols based on a critical review of the literature on the epidemiology, etiology, diagnosis, prognosis, and new therapeutic options in PE, and addresses some cost-effectiveness issues related to the main types of PE.


Assuntos
Derrame Pleural , Pneumologia , Cirurgia Torácica , Humanos , Derrame Pleural/diagnóstico , Derrame Pleural/etiologia , Derrame Pleural/terapia , Exsudatos e Transudatos , Toracentese/efeitos adversos , Toracentese/métodos
9.
Arch Bronconeumol ; 59(3): 178-179, 2023 03.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-36243637

Assuntos
Bronquiectasia , Humanos
10.
J Clin Med ; 13(1)2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38202089

RESUMO

High-flow nasal cannula (HFNC) is a respiratory support technique that delivers a controlled concentration of oxygen with high flow, heat, and humidity via the nasal pathway. As it has many physiological effects, its use has increased for a variety of clinical indications; however, there is limited guidance on using HFNC as a respiratory support tool during endoscopic procedures. We conducted a narrative review to evaluate the effect of HFNC as an adjuvant tool during fiberoptic bronchoscopy (FOB), upper gastrointestinal tract endoscopy, and surgical procedures in adults. A search of the PubMed and Cochrane databases were performed. Approximately 384 publications were retrieved, and 99 were selected (93 original works and 6 case reports with a literature review). In patients who underwent FOB, HFNC appears to be superior to conventional oxygen therapy (COT) in preventing hypoxaemia. In contrast, for gastrointestinal endoscopy, the current evidence is insufficient to recommend HFNC over COT in a cost-effective manner. Finally, in surgical procedures such as laryngeal microsurgery or thoracic surgery, HFNC has been shown to be a safe and effective alternative to orotracheal intubation. As the results are heterogeneous, we advocate for the need for more quality studies to understand the effectiveness of HFNC during endoscopic procedures.

11.
Artigo em Inglês | MEDLINE | ID: mdl-35082492

RESUMO

PURPOSE: Home non-invasive ventilation (NIV) is recommended in patients with COPD and hypercapnic chronic respiratory failure (HCRF). The mechanism by it can improve alveolar ventilation during spontaneous breathing is not yet completely explained. Our aim is to evaluate the impact of on diaphragm muscle function in a series of patients with HCRF. PATIENTS AND METHODS: Observational, longitudinal, prospective study of a series of patients with very severe chronic obstruction to airflow treated with home high imntensity NIV (HINIV). Patients underwent a baseline and after 12 months assessment including adherence to treatment, quality of life, respiratory function tests and diaphragmatic ultrasound. SPSS v.26 software was used for statistical analysis. RESULTS: We studied 30 patients, 63% male, the mean age was 60.8 (±6.4) years old. Patients had a severe obstructive ventilatory pattern [FEV1 21.8 (±6.1)%] and hypercapnia [pCO2 56.4 (±7.2) mmHg]. After 12 months of HINIV, we observed significant increases in FVC of 9.2% (p = 0.002), FEV1 of 3.5% (p = 0.04), MIP of 9.4% (p = 0.006), and 6-minute-walking test (6MWT) of 31.9 m (p = 0.001), as well as decreases in paCO2 of 12.5 mmHg (p = 0.001), HCO3 of 4.7 mmol/L (p = 0.001) and BODE index from 7 to 6. Diaphragmatic ultrasound demonstrated an increase in the thickening fraction of 14% (p = 0.002). Respiratory symptoms (p = 0.04), physical function (p = 0.03), and sleep (p = 0.04) also improved. CONCLUSION: In patients with HCRF due to very severe chronic obstruction to airflow, long-term HINIV can improve respiratory performance by improving the function of the diaphragmatic musculature. Larger multicenter clinical trials are needed to confirm the results suggested in this study.


Assuntos
Ventilação não Invasiva , Doença Pulmonar Obstrutiva Crônica , Insuficiência Respiratória , Diafragma/diagnóstico por imagem , Feminino , Humanos , Hipercapnia/diagnóstico , Hipercapnia/etiologia , Hipercapnia/terapia , Masculino , Pessoa de Meia-Idade , Ventilação não Invasiva/efeitos adversos , Ventilação não Invasiva/métodos , Estudos Prospectivos , Doença Pulmonar Obstrutiva Crônica/complicações , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Doença Pulmonar Obstrutiva Crônica/terapia , Qualidade de Vida , Insuficiência Respiratória/diagnóstico , Insuficiência Respiratória/etiologia , Insuficiência Respiratória/terapia
12.
Mol Syst Biol ; 17(10): e10145, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34612607

RESUMO

Bacteria present a promising delivery system for treating human diseases. Here, we engineered the genome-reduced human lung pathogen Mycoplasma pneumoniae as a live biotherapeutic to treat biofilm-associated bacterial infections. This strain has a unique genetic code, which hinders gene transfer to most other bacterial genera, and it lacks a cell wall, which allows it to express proteins that target peptidoglycans of pathogenic bacteria. We first determined that removal of the pathogenic factors fully attenuated the chassis strain in vivo. We then designed synthetic promoters and identified an endogenous peptide signal sequence that, when fused to heterologous proteins, promotes efficient secretion. Based on this, we equipped the chassis strain with a genetic platform designed to secrete antibiofilm and bactericidal enzymes, resulting in a strain capable of dissolving Staphylococcus aureus biofilms preformed on catheters in vitro, ex vivo, and in vivo. To our knowledge, this is the first engineered genome-reduced bacterium that can fight against clinically relevant biofilm-associated bacterial infections.


Assuntos
Biofilmes , Staphylococcus aureus , Antibacterianos , Humanos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/genética , Fatores de Virulência
13.
Foods ; 10(6)2021 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-34207083

RESUMO

Extensive pig systems are gaining importance as quality production systems and as the standard for sustainable rural development and animal welfare. However, the effects of natural foods on Salmonella epidemiology remain unknown. Herein, we assessed the presence of Salmonella and the composition of the gut microbiota in pigs from both Salmonella-free and high Salmonella prevalence farms. In addition, risk factors associated with the presence of Salmonella were investigated. The pathogen was found in 32.2% of animals and 83.3% of farms, showing large differences in prevalence between farms. Most isolates were serovars Typhimurium monophasic (79.3%) and Bovismorbificans (10.3%), and exhibited a multi-drug resistance profile (58.6%). Risk factor analysis identified feed composition, type/variety of vegetation available, and silos' cleaning/disinfection as the main factors associated with Salmonella prevalence. Clear differences in the intestinal microbiota were found between Salmonella-positive and Salmonella-negative populations, showing the former with increasing Proteobacteria and decreasing Bacteroides populations. Butyrate and propionate producers including Clostridium, Turicibacter, Bacteroidaceae_uc, and Lactobacillus were more abundant in the Salmonella-negative group, whereas acetate producers like Sporobacter, Escherichia or Enterobacter were more abundant in the Salmonella-positive group. Overall, our results suggest that the presence of Salmonella in free-range pigs is directly related to the natural vegetation accessible, determining the composition of the intestinal microbiota.

15.
Microorganisms ; 8(12)2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-33371352

RESUMO

After Salmonella Enteritidis and S. Typhimurium, S. 4,[5],12:i:- is the most reported serovar in human clinical cases. During the past 20 years, many tools have been used for its typing and second-phase flagellar deletion characterization. Currently, whole genome sequencing (WGS) and different bioinformatic programs have shown the potential to be more accurate than earlier tools. To assess this potential, we analyzed by WGS and in silico typing a selection of 42 isolates of S. 4,[5],12:i:- and S. Typhimurium with different in vitro characteristics. Comparative analysis showed that SeqSero2 does not differentiate fljB-positive S. 4,[5],12:i:- strains from those of serovar Typhimurium. Our results proved that the strains selected for this work were non-clonal S. 4,[5],12:i:- strains circulating in Spain. Using WGS data, we identified 13 different deletion types of the second-phase flagellar genomic region. Most of the deletions were generated by IS26 insertions, showing orientation-dependent conserved deletion ends. In addition, we detected S. 4,[5],12:i:- strains of the American clonal line that would give rise to the Southern European clone in Spain. Our results suggest that new S. 4,[5],12:i:- strains are continuously emerging from different S. Typhimurium strains via different genetic events, at least in swine products.

16.
BMJ Open Respir Res ; 7(1)2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33246973

RESUMO

BACKGROUND: Recessive mutations in the thymidine kinase 2 (TK2) gene cause a rare mitochondrial myopathy, frequently with severe respiratory involvement. Deoxynucleoside therapy is currently under investigation. RESEARCH QUESTION: What is the impact of nucleosides in respiratory function in patients with TK2-deficient myopathy? STUDY DESIGN AND METHODS: Retrospective observational study of patients treated with deoxycytidine and deoxythymidine. Evaluations were performed every 3 to 4 months after treatment during approximately 30 months. Forced vital capacity (FVC), maximuminspiratory and expiratory pressures (MIP/MEP), sniff nasal inspiratory pressure (SNIP), cough peak flow (CPF), arterial blood gas and nocturnal pulse oximeter (SpO2) were collected. RESULTS: We studied six patients, five of which were women, with a median age at onset of symptoms was 35.8 (range 5 to 60) years old. Patients presented a restrictive ventilatory pattern (median FVC of 50 (26 to 71)%) and severe neuromuscular respiratory weakness (MIP 38 (12 to 47)% and SNIP 14 (8 to 19) cmH2O). Four patients required ventilatory support before starting the treatment. FVC improved by 6%, proportion of sleep time with SpO2 <90% diminished from 14% to 0%, CPF increased by 23%, MEP increased by 73%, production and management of bronchial secretions improved and respiratory infections diminished. INTERPRETATION: Early detection of respiratory involvement requires an active search, even in asymptomatic patients. The nucleosides therapy may improve respiratory function, and stabilise the loss of respiratory capacity.


Assuntos
Desoxicitidina , Miopatias Mitocondriais , Músculos Respiratórios , Timidina , Adolescente , Adulto , Criança , Pré-Escolar , Desoxicitidina/uso terapêutico , Feminino , Humanos , Pessoa de Meia-Idade , Miopatias Mitocondriais/diagnóstico , Miopatias Mitocondriais/tratamento farmacológico , Miopatias Mitocondriais/genética , Timidina/uso terapêutico , Timidina Quinase/genética , Capacidade Vital , Adulto Jovem
17.
Front Microbiol ; 11: 7, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32038593

RESUMO

Phage lytic proteins are promising antimicrobials that could complement conventional antibiotics and help to combat multi-drug resistant bacteria that cause important human and animal infections. Here, we report the characterization of endolysin LysRODI (encoded by staphylophage phiIPLA-RODI) and its application as a prophylactic mastitis treatment. The main properties of LysRODI were compared with those of endolysin LysA72 (encoded by staphylophage phiIPLA35) and the chimeric protein CHAPSH3b (derived from the virion-associated peptidoglycan hydrolase HydH5 and lysostaphin). Time-kill experiments performed with Staphylococcus aureus and Staphylococcus epidermidis demonstrated that the killing rate of LysRODI and CHAPSH3b is higher than that of LysA72 (0.1 µM protein removed 107 CFU/ml of S. aureus in 30 min). Of note, all proteins failed to select resistant mutants as bacterial exposure to sub-lethal concentrations of the proteins did not alter the MIC values. Additionally, LysRODI and CHAPSH3b were non-toxic in a zebrafish embryo model at concentrations near the MIC (0.5 and 0.7 µM, respectively). Moreover, these two proteins significantly reduced mortality in a zebrafish model of systemic infection. In contrast to LysRODI, the efficacy of CHAPSH3b was dose-dependent in zebrafish, requiring higher-dose treatments to achieve the maximum survival rate. For this reason, LysRODI was selected for further analysis in mice, demonstrating great efficacy to prevent mammary infections by S. aureus and S. epidermidis. Our findings strongly support the use of phage lytic proteins as a new strategy to prevent staphylococcal mastitis.

18.
Foodborne Pathog Dis ; 17(6): 411-417, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31809191

RESUMO

Salmonellosis is one of the main foodborne diseases worldwide. Breeding sows asymptomatically infected with Salmonella can transmit the pathogen to piglets and humans. The isolation of Salmonella from mesenteric lymph nodes (MLNs) is considered a demonstration of asymptomatic infection in swine. As previous breeding sow studies have been performed using feces, the aim of this work was to study the occurrence of Salmonella infections by sampling MLNs, in comparison to their serological status. First, Salmonella fecal shedding was studied in 12/16 large breeding farms to establish the framework of study. Then, MLN (n = 264) and blood (n = 237) samples were obtained at an abattoir from sows of 15 of these 16 breeding farms. Additionally, risk factors associated with Salmonella MLN infection were analyzed. A total of 6.1% (16/264) sows, distributed in 40% (6/15) of the farms, had the pathogen in MLN. Salmonella Typhimurium was the most frequent serovar isolated. Interestingly, 43.8% (7/16) of MLN isolates were susceptible to all the antimicrobials tested and were found distributed throughout all farms with at least one sow positive. As well, one isolate of the emerging DT195 clone was detected and found to be resistant to six antibiotic families (ASSuTNx-Cfx). The serovars and the resistance profiles of the Salmonella isolates from feces were completely different to those obtained from MLNs. The seroprevalence (41.8% of sows and 100% of farms) was higher than that of MLN infections, showing no concordance (k = 0.15) between these two diagnostic tests in sows. Strategies directed to correct two risk factors (i.e., administration of dry food and old premises) would most likely help to reduce Salmonella infections in breeding sows.


Assuntos
Fezes/microbiologia , Linfonodos/microbiologia , Mesentério/microbiologia , Salmonelose Animal/epidemiologia , Salmonelose Animal/microbiologia , Salmonella/classificação , Animais , Antibacterianos/farmacologia , Infecções Assintomáticas , Derrame de Bactérias , Feminino , Prevalência , Fatores de Risco , Salmonella/efeitos dos fármacos , Salmonella/isolamento & purificação , Estudos Soroepidemiológicos , Sorotipagem , Suínos , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/microbiologia
19.
Acta Neuropathol ; 138(2): 251-273, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31006066

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease in which the formation of extracellular aggregates of amyloid beta (Aß) peptide, fibrillary tangles of intraneuronal tau and microglial activation are major pathological hallmarks. One of the key molecules involved in microglial activation is galectin-3 (gal3), and we demonstrate here for the first time a key role of gal3 in AD pathology. Gal3 was highly upregulated in the brains of AD patients and 5xFAD (familial Alzheimer's disease) mice and found specifically expressed in microglia associated with Aß plaques. Single-nucleotide polymorphisms in the LGALS3 gene, which encodes gal3, were associated with an increased risk of AD. Gal3 deletion in 5xFAD mice attenuated microglia-associated immune responses, particularly those associated with TLR and TREM2/DAP12 signaling. In vitro data revealed that gal3 was required to fully activate microglia in response to fibrillar Aß. Gal3 deletion decreased the Aß burden in 5xFAD mice and improved cognitive behavior. Interestingly, a single intrahippocampal injection of gal3 along with Aß monomers in WT mice was sufficient to induce the formation of long-lasting (2 months) insoluble Aß aggregates, which were absent when gal3 was lacking. High-resolution microscopy (stochastic optical reconstruction microscopy) demonstrated close colocalization of gal3 and TREM2 in microglial processes, and a direct interaction was shown by a fluorescence anisotropy assay involving the gal3 carbohydrate recognition domain. Furthermore, gal3 was shown to stimulate TREM2-DAP12 signaling in a reporter cell line. Overall, our data support the view that gal3 inhibition may be a potential pharmacological approach to counteract AD.


Assuntos
Doença de Alzheimer/imunologia , Galectina 3/fisiologia , Glicoproteínas de Membrana/fisiologia , Microglia/metabolismo , Receptores Imunológicos/fisiologia , Doença de Alzheimer/genética , Doença de Alzheimer/patologia , Amiloide/imunologia , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/toxicidade , Animais , Células Cultivadas , Modelos Animais de Doenças , Feminino , Galectina 3/toxicidade , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Humanos , Inflamação , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microglia/imunologia , Terapia de Alvo Molecular , Polimorfismo de Nucleotídeo Único , Agregação Patológica de Proteínas
20.
Anal Chim Acta ; 1054: 157-166, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30712586

RESUMO

Salmonella is a leading source of bacterial foodborne illness in humans, causing gastroenteritis outbreaks with bacteraemia occurrences that can lead to clinical complications and death. Eggs, poultry and pig products are considered as the main carriers of the pathogenic Salmonella for humans. To prevent this relevant zoonosis, key changes in food safety regulations were undertaken to improve controls in the food production chain. Despite these measures, large outbreaks of salmonellosis were reported worldwide in the last decade. Thus, new strategies for Salmonella detection are a priority for both, food safety and public health authorities. Such detection systems should provide significant reduction in diagnostic time (hours) compared to the currently available methods (days). Herein, we report on the discovery and characterization of nucleic acid probes for the sensitive and specific detection of live Salmonella within less than 8 h of incubation. We are the first to postulate the nuclease activity derived from Salmonella as biomarker of infection and its utility to develop innovative detection strategies. Our results have shown the screening and identification of two oligonucleotide sequences (substrates) as the most promising probes for detecting Salmonella - Sal-3 and Sal-5. The detection limits for both probes were determined with the reference Salmonella Typhimurium (STM 1) and Salmonella Enteritidis (SE 1) cultures. Sal-3 has reported LOD values around 105 CFU mL-1 for STM 1 and 104 CFU mL-1 for SE 1, while Sal-5 proves to be a slightly better probe, with LODs of 104 CFU mL-1 for STM 1 and 104 CFU mL-1 for SE 1. Both selected probes have shown the capability to recognize 49 out of 51 different Salmonella serotypes tested in vitro and the most frequent serotypes in porcine mesenteric lymph nodes as a standard sample used in fattening-pig salmonellosis baseline studies. Notably, our results showed 100% correlation between nuclease detection and the PCR-InvA or ISO-6579 standard method, underlining the great potential of this innovative nucleic acids technology to be implemented as a rapid method for food safety testing.


Assuntos
Microbiologia de Alimentos/métodos , Sondas de Oligonucleotídeos/metabolismo , Salmonella/isolamento & purificação , Salmonella/metabolismo , Desoxirribonucleases/química , Desoxirribonucleases/metabolismo , Inocuidade dos Alimentos , Limite de Detecção , Modelos Moleculares , Conformação de Ácido Nucleico , Sondas de Oligonucleotídeos/química , Sondas de Oligonucleotídeos/genética , Conformação Proteica , Salmonella/enzimologia , Fatores de Tempo
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