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1.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(8): 889-894, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31484249

RESUMO

Objective: To understand the seasonality and etiological characteristics of infectious diarrhea in adults from Shanghai. Methods: Adult patients with diarrhea who had visited the enteric disease clinics in 22 hospitals that carrying on the Diarrhea Comprehensive Surveillance sentinel programs in Shanghai during 2014-2017, were surveyed. Stool specimens were collected according to the different intervals of sampling and detected for 12 bacteria and 5 viruses. Concentration ratio and circular distribution method were used for data analysis. Results: From 2014 to 2017, a total of 9 573 stool specimens were collected from the targeted diarrhea patients ≥18 years old (n=96 067), through the Shanghai Diarrhea Comprehensive Surveillance program. The positive rate of detection was 46.44%. Seasonal peaks of infectious diarrhea were both seen in summer (bacteria peak, diarrheagenic Escherichia coli and Vibrio parahaemolyticus, etc.) and in winter (virus peak, Norovirus, etc.). Both bacterial and viral infections presented seasonal concentration (Raleigh's test P<0.001) but more obvious with bacterial infection. Viral infection accounted for 60.19% of the cause of infectious diarrhea. The top five predominant pathogens appeared as Norovirus, Rotavirus, diarrheagenic Escherichia coli, Vibrio parahaemolyticus, and Salmonella spp.. Conclusions: Among the adult outpatients with infectious diarrhea in Shanghai, obvious seasonality was seen, with peaks in both summer and winter. Viral infection with Norovirus in particular, appeared as the predominant source of infection. Active, continuous and comprehensive diarrhea-related surveillance programs would be able to monitor the changing dynamic of pathogen spectrum, and lead to the adoption of targeted preventive measures.


Assuntos
Bactérias/isolamento & purificação , Diarreia/diagnóstico , Diarreia/etiologia , Disenteria/diagnóstico , Disenteria/etiologia , Fezes , Pacientes Ambulatoriais/estatística & dados numéricos , Vigilância da População/métodos , Vírus/isolamento & purificação , Adolescente , Adulto , Bactérias/classificação , Criança , Pré-Escolar , China/epidemiologia , Diarreia/epidemiologia , Disenteria/epidemiologia , Escherichia coli/isolamento & purificação , Fezes/microbiologia , Fezes/virologia , Humanos , Pessoa de Meia-Idade , Norovirus/isolamento & purificação , Rotavirus/isolamento & purificação , Salmonella/classificação , Salmonella/isolamento & purificação , Estações do Ano , Vibrio parahaemolyticus/isolamento & purificação , Vírus/classificação
2.
Niger J Clin Pract ; 22(8): 1083-1090, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31417051

RESUMO

Aims: The aim of this study was to provide epidemiological data about the presence of Salmonella spp. and Shigella spp. in raw milk samples collected from different animals. Methods: A total of 231 raw milk samples from 48 cows, 65 goats, 65 sheep, and 53 donkeys were studied. The ISO 6579:2002 and ISO 21567:2004 methods, antimicrobial susceptibility tests, and serotyping were performed. Species and subspecies discriminations were made via matrix-assisted laser desorption/ionization-time of flight mass spectrometry. After DNA isolation from all samples, Salmonella spp. and Shigella spp. were detected using real-time polymerase chain reaction (PCR) kits. Results: Five samples (2.16%) showed positivity out of 231 raw milk samples for Salmonella spp., and 2 (0.87%) samples were detected to be positive by multiplex real-time PCR design. Conclusion: We found that raw milk samples were not free of Salmonella spp. and Shigella spp. and need to be tested routinely to avoid public health problems. Rapid and reliable real-time PCR method can be developed and used for this purposes instead of slow bacterial culture processes.


Assuntos
DNA Bacteriano/análise , Contaminação de Alimentos/análise , Leite/microbiologia , Reação em Cadeia da Polimerase/métodos , Salmonella/genética , Salmonella/isolamento & purificação , Shigella/genética , Shigella/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Animais , Bovinos , Equidae , Feminino , Cabras , Humanos , Salmonella/classificação , Sensibilidade e Especificidade , Ovinos , Shigella/classificação
3.
J Agric Food Chem ; 67(33): 9390-9398, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31365249

RESUMO

Various pathogens may coexist in one sample; however, detection methods that rely on traditional selective culture media or immune agents designed specifically for a certain target are unsuitable for multiple targets. It is important to develop a simultaneous and sensitive detection method for multiple pathogens. Here, a multicolor and ultrasensitive enzyme-linked immunosorbent assay (ELISA) platform based on the fluorescence hybridization chain reaction (HCR) was developed. In the assay, multicolor fluorescence concatemers formed as signal amplifiers and signal reporters in the presence of target pathogens. When HCR occurred, Escherichia coli O157:H7, Salmonella serotype Choleraesuis, and Listeria monocytogenes were detected simultaneously with three different fluorescences. Additionally, the limits of detection for E. coli O157:H7, Salmonella Choleraesuis, and L. monocytogenes were 3.4 × 101, 6.4 × 100, and 7.0 × 101 CFU/mL, respectively. The assay achieved ultrasensitive, specific, and simultaneous detection of three pathogens and can be applied to the detection of pathogens in milk samples. Therefore, this multicolor and ultrasensitive ELISA platform has great potential in the application of simultaneous detection of pathogens.


Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Escherichia coli O157/isolamento & purificação , Listeria monocytogenes/isolamento & purificação , Leite/microbiologia , Salmonella/isolamento & purificação , Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/instrumentação , Fluorescência , Microbiologia de Alimentos , Sensibilidade e Especificidade
4.
Anal Bioanal Chem ; 411(23): 6067-6080, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31273413

RESUMO

Rapid detection of trace Salmonella is urgently needed to ensure food safety. We present an innovative pretreatment strategy, based on a two-step enrichment culture and immunomagnetic separation, combined with a chemiluminescence microparticle immunoassay to detect at least one proliferative Salmonella cell in 25 mL (25 g) food. The capture performance of immunomagnetic beads (IMBs) of sizes for Salmonella was investigated, and the IMBs of size 2.8 µm showed a high capture efficiency of 60.7% in 25 mL milk and 74.5% in 25 mL chicken culture filtrate, which ensured the successful capture of trace Salmonella after 2.5 h in situ enrichment even from only one Salmonella cell. The separated Salmonella cells, reaching an amount of 103 colony-forming units (CFU) by a secondary enrichment for 3 h, were detected by a horseradish peroxidase chemiluminescence reaction with 4-(1-imidazolyl)phenol as an enhancer, which evidenced a linear response for Salmonella concentrations ranging from 2.3 × 102 to 7.8 × 104 CFU/mL. The entire detection process was completed within 8 h, with a very low detection limit of 1 CFU/25 mL (25 g), which was verified by colony counting, and a small degree of interference of 0.17-1.06%. Trace Salmonella from five different serovars in milk and chicken was successfully detected without false negative or false positive results. Furthermore, this study provides a basis to develop a fully automated instrument based on IMBs that includes all steps from sample preparation to chemiluminescence microparticle immunoassay for high-throughput screening of foodborne pathogens. Graphical abstract.


Assuntos
Contaminação de Alimentos/análise , Medições Luminescentes/métodos , Leite/microbiologia , Aves Domésticas/microbiologia , Salmonella/isolamento & purificação , Animais , Galinhas/microbiologia , Contaminação de Alimentos/economia , Inocuidade dos Alimentos/métodos , Imunoensaio/economia , Imunoensaio/métodos , Separação Imunomagnética/economia , Separação Imunomagnética/métodos , Limite de Detecção , Medições Luminescentes/economia , Infecções por Salmonella/microbiologia , Fatores de Tempo
5.
Int J Food Microbiol ; 305: 108250, 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31226567

RESUMO

The purpose of this study was to determine the effectiveness of a commercial Salmonella bacteriophage mixture (SalmoFresh™ 6-phage strains) and to compare its effectiveness with a chlorinated water treatment to reduce Salmonella on produce and seeds at different temperatures and storage times. Two sets of experiments were designed to test phage and chlorinated water effectiveness on produce at 2, 10 and 25 °C at different storage times (1, 24, 48 and 72 h). First, SalmoFresh™ was applied to the surface of lettuce, mung bean sprouts and mung bean seeds that were spot-inoculated with a five Salmonella strain mixture (Newport, Braenderup, Typhimurium, Kentucky, and Heidelberg, 105 CFU/mL) by spraying phages onto lettuce (n = 48 pieces, 3×3 cm2 per treatment) and sprouts (n = 48 pieces per treatment). A second set of experiments (scaled-up) consisted in the application of phages by immersion to Salmonella adulterated lettuce (600 g), 300 g sprouts (300 g) or mung bean seeds (30 g) in a phage cocktail (108 PFU/mL) for 15 min (lettuce and sprouts) or 1 h (seeds). Another group of samples was washed with chlorinated water and yet another group was treated with a combination of chlorinated water followed by phage cocktail. Each experiment was repeated three times by quadruplicates. After the treatments for spot-inoculated and scaled-up experiments, lettuce and sprouts were separated into different lots (10 g/lot) and stored at 2, 10 and 25 °C; Salmonella was enumerated after 1, 24, 48 and 72 h. Adulterated phage-treated seeds were packaged and stored dry at 25 °C. Salmonella was enumerated after 72 h of storage. Groups of phage treated mung bean seeds (720 g) were germinated, and the reduction in Salmonella determined. Results of microplate virulence assays indicated that SalmoFresh™ reduced (P = 0.007) Salmonella by an average of 5.34 logs CFU/mL after 5 h at 25 °C. Spraying SalmoFresh™ onto lettuce and sprouts reduced Salmonella by 0.76 and 0.83 log10 CFU/g, respectively (P < 0.01). Immersion of produce in a phage solution was better at killing Salmonella P < 0.05) than spraying it onto the surface, reducing Salmonella by 2.43 and 2.16 log10 CFU/g on lettuce and sprouts, respectively. SalmoFresh™ was an effective biocontrol intervention to reduce Salmonella on lettuce and sprouts. On seeds, although a reduction was observed, Salmonella was able to grow exponentially during germination; therefore, the phage cocktail was not effective on mung bean seeds or sprouts obtained from adulterated seeds. The combination of hurdles, chlorination fallowed by the phage cocktail was the most effective treatment to reduce Salmonella on lettuce and sprouts.


Assuntos
Conservação de Alimentos/métodos , Alface/microbiologia , Fagos de Salmonella/fisiologia , Salmonella/isolamento & purificação , Salmonella/virologia , Sementes/microbiologia , Vigna/microbiologia , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Germinação , Salmonella/classificação , Salmonella/genética , Sementes/crescimento & desenvolvimento , Vigna/crescimento & desenvolvimento
6.
Vet Microbiol ; 233: 118-123, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31176397

RESUMO

The vast capacity for maintenance and dissemination in the environment are major challenges for the control of Salmonella spp. in poultry farms. The aim of this study was to assess environmental contamination by non-typhoidal Salmonella in successive broiler flocks in nine commercial broiler farms integrated with three companies in the south of Brazil, for a twelve-month production period. Recycled broiler litter, feed and swabs from the evaporative cooling system pads were analyzed, and the total enterobacteria count in the litter samples was ascertained. Positive broiler houses were identified in two of the three broiler companies studied, in which non-typhoidal Salmonella were detected for the first time in the first or second flock, and recurred in the recycled litter of subsequent flocks. Feed and evaporative cooling pad swab samples were also positive in at least one of the assessed flocks. The majority of the isolates (87.5%) originating from different flocks, broiler houses and companies that were sampled were identified as S. Heidelberg, with the prevalence of one single genotype. The total enterobacteria levels in the litter diminished as the flocks progressed, but the presence of Salmonella spp. was constant over the course of time, indicating that the litter management procedures were not capable of interrupting the cycle of residual contamination. The predominance of S. Heidelberg highlights its emergence and dissemination in this region, as well as its resistance and maintenance in the environment, and reinforces the need to improve prevention and recycled litter management measures.


Assuntos
Galinhas/microbiologia , Microbiologia Ambiental , Aves Domésticas/microbiologia , Salmonelose Animal/epidemiologia , Salmonella/genética , Criação de Animais Domésticos , Animais , Brasil/epidemiologia , Genótipo , Abrigo para Animais/normas , Estudos Longitudinais , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/prevenção & controle , Prevalência , Salmonella/isolamento & purificação , Sorogrupo
7.
BMC Vet Res ; 15(1): 212, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31234834

RESUMO

BACKGROUND: Multi-drug resistant bacteria are seen increasingly and there are gaps in our understanding of the complexity of antimicrobial resistance, partially due to a lack of appropriate statistical tools. This hampers efficient treatment, precludes determining appropriate intervention points and renders prevention very difficult. METHODS: We re-analysed data from a previous study using additive Bayesian networks. The data contained information on resistances against seven antimicrobials and seven potential risk factors from 86 non-typhoidal Salmonella isolates from laying hens in 46 farms in Uganda. RESULTS: The final graph contained 22 links between risk factors and antimicrobial resistances. Solely ampicillin resistance was linked to the vaccinating person and disposal of dead birds. Systematic associations between ampicillin and sulfamethoxazole/trimethoprim and chloramphenicol, which was also linked to sulfamethoxazole/trimethoprim were detected. Sulfamethoxazole/trimethoprim was also directly linked to ciprofloxacin and trimethoprim. Trimethoprim was linked to sulfonamide and ciprofloxacin, which was also linked to sulfonamide. Tetracycline was solely linked to ciprofloxacin. CONCLUSIONS: Although the results needs to be interpreted with caution due to a small data set, additive Bayesian network analysis allowed a description of a number of associations between the risk factors and antimicrobial resistances investigated.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Doenças das Aves Domésticas/microbiologia , Salmonelose Animal/microbiologia , Salmonella/efeitos dos fármacos , Animais , Teorema de Bayes , Feminino , Fatores de Risco , Salmonella/classificação , Salmonella/isolamento & purificação , Uganda
8.
Anal Chim Acta ; 1074: 80-88, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31159942

RESUMO

A rapid and sensitive electrochemical biosensor was constructed to detect Salmonella using invA gene biosensor. The biosensing was based on polyrrole-reduced graphene oxide (PPy-rGO) nanocomposite modified glassy carbon electrode (GCE) and signal amplification with horseradish peroxidase-streptavidin biofunctionalized gold nanoparticles (AuNPs-HRP-SA). PPy-rGO was prepared at 60 °C by chemical reduction of PPy-functionalized graphene oxide (PPy-GO) that was synthesized by in situ polymerization at room temperature. The detection signal was amplified via enzymatic reduction of H2O2 in the presence of hydroquinone (HQ) using AuNPs-HRP-SA as nanotag. Under optimal conditions, the differential pulse voltametric (DPV) signal from the biosensor was linearly related to the logarithm of target invA gene concentrations from 1.0 × 10-16 to 1.0 × 10-10 M, and the limit of detection (LOD) was 4.7 × 10-17 M. The biosensor can also detect Salmonella in the range of 9.6 to 9.6 × 104 CFU mL-1, with LOD of 8.07 CFU mL-1. The biosensor showed good regeneration ability, acceptable selectivity, repeatability and stability, which bode well as an alternative method for Salmonella screening.


Assuntos
Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana/métodos , Grafite/química , Nanopartículas Metálicas/química , Polímeros/química , Pirróis/química , Salmonella/isolamento & purificação , Técnicas Biossensoriais/métodos , Carbono , DNA Bacteriano/genética , Técnicas Eletroquímicas/instrumentação , Técnicas Eletroquímicas/métodos , Eletrodos , Enzimas Imobilizadas/química , Ouro/química , Peroxidase do Rábano Silvestre/química , Peróxido de Hidrogênio/química , Hidroquinonas/química , Limite de Detecção , Nanocompostos/química , Hibridização de Ácido Nucleico , Oxirredução , Salmonella/genética , Estreptavidina/química
9.
Anal Chim Acta ; 1075: 144-151, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31196420

RESUMO

Salmonella is a widely distributed, extremely harmful bacteria, the presence of which requires confirmation via an on-site visual biosensor. In this study, we constructed a label-free, cascade amplification visualization biosensor for the sensitive and rapid detection of Salmonella enterica subsp. enterica serovar typhimurium based on the RDTG principle (recombinase polymerase amplification (RPA), duplex-specific enzyme (DSN) cleavage, terminal deoxynucleotidyl transferase (TdT) extension and G-quadruplexes output). Following DNA extraction of Salmonella spp., the first step in the construction involved the recognition and amplification of nucleic acids, carried out by RPA, to achieve the first signal amplification within 10 min. This RPA product was then specifically cleaved by DSN to produce a large number of small double-stranded DNA (dsDNA) products with 3'-OH within 15 min to achieve the second signal amplification. Thereafter, TdT was employed to empower these small 3'-OH dsDNA products to extend and produce a large number of long G-rich single-stranded DNAs (ssDNAs) within 20 min, thus realizing the third signal increase. These long G-rich ssDNA products displayed a color change that could be directly observed through the naked eye by adding H2O2/3,3',5,5'-tetramethylbenzidine (TMB). The RDTG biosensor for the detection of Salmonella spp. has several advantages, including a low limit of 6 cfu/mL. It is an isothermal-free instrument, simple to operate, with a rapid detection time of less than 1.5 h. Furthermore, it can be visually characterized and quantified by a microplate reader to detect Salmonella spp., in food and environmental samples, and it has broad application prospects.


Assuntos
Técnicas Biossensoriais/métodos , DNA Bacteriano/análise , Salmonella/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Benzidinas/química , DNA Nucleotidilexotransferase/química , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , DNA de Cadeia Simples/análise , DNA de Cadeia Simples/química , DNA de Cadeia Simples/genética , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Quadruplex G , Peróxido de Hidrogênio/química , Limite de Detecção , Técnicas de Amplificação de Ácido Nucleico/métodos , Recombinases/química , Salmonella/genética , Sensibilidade e Especificidade , Iogurte/microbiologia
10.
Environ Monit Assess ; 191(7): 456, 2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31230187

RESUMO

The objective of the study was to assess the microbiological safety of popular recreational swimming sites in Central California. Water samples were collected from eleven monitoring sites across the lower reaches of two watersheds for two consecutive swimming seasons (2012-2013), and levels of indicator and pathogenic microorganisms were determined. Data on ambient weather and water chemistry were collected for analyzing their associations with microorganisms in water. All water samples were positive for indicator E. coli with mean concentrations per site ranging from 3.07 to 216.11 MPN/100 ml in 2012 and 13.4 to 226.97 MPN/100 ml in 2013. Mean E. coli concentrations in 27% and 36% samplings sites exceeded the EPA 2012 Recreational Water Quality Criteria recommended mean concentration of ≤ 126 CFU/100 ml of E. coli, in 2012 and 2013, respectively. Cryptosporidium spp. oocysts were detected in all water samples from all sampling sites, with an overall prevalence of 50% and mean concentrations of 0.08 oocysts/l in 2012 and 0.19 oocysts/l in 2013. Giardia spp. cysts were detected at eight sites, with an overall prevalence of 28.8% and mean concentration of 0.2 cysts/l in both years. The majority of the detected Cryptosporidium spp. oocysts and Giardia spp. cysts appeared damaged under microscopy. E. coli O157:H7 was detected in 9% of water samples, with positive samples limited to three sites. Salmonella spp. were detected in all but one site across the two years, with mean concentrations of 0.94 MPN/l in 2012 and 1.85 MPN/l in 2013. Cryptosporidium spp. oocyst concentrations were negatively associated with 30-day mean wind speed and cumulative precipitation and dissolved oxygen in water. Giardia spp. cyst concentrations were positively associated with turbidity and pH of water and negatively associated with E. coli concentrations and 24-h mean air temperature. Salmonella spp. concentrations were positively associated with 30-day mean air temperature. The occurrence of E. coli O157:H7 was positively associated with previous 30-day cumulative precipitation.


Assuntos
Cryptosporidium/isolamento & purificação , Monitoramento Ambiental/métodos , Escherichia coli O157/isolamento & purificação , Giardia/isolamento & purificação , Oocistos/isolamento & purificação , Salmonella/isolamento & purificação , Qualidade da Água , Água/parasitologia , Animais , California , Parques Recreativos , Estações do Ano , Natação , Microbiologia da Água , Tempo (Meteorologia)
11.
Artigo em Inglês | MEDLINE | ID: mdl-31091403

RESUMO

Salmonella Hessarek is an uncommon serotype in Australia. We report on the investigation of a protracted outbreak of 25 cases of S. Hessarek gastroenteritis in which cases were defined as any laboratory confirmed case of Salmonella Hessarek notified to the South Australian Communicable Disease Control Branch from 1st March 2017 to 3 July 2018. We conducted a descriptive case series investigation interviewing all cases and 17 (68%) reported consuming brand X free-range eggs. Four samples of one-dozen brand X eggs were cultured for the presence of Salmonella spp. One out of the four samples returned positive for S. Hessarek in the contents of the eggs; Salmonella was not present in any of the whole egg rinses of the four samples. The high proportion of cases reporting the consumption of brand X free-range eggs and the isolation of S. Hessarek from sampling four dozen brand X eggs is an unusually strong signal implicating brand X eggs as the source of this outbreak. From a public health perspective, it is important to understand the behaviour of S. Hessarek including its ability to be present in the content of eggs and further research is recommended. The findings in this investigation into a rare Salmonella serotype highlight the need for continuous monitoring of the epidemiology of Salmonella in Australia including the epidemiology of egg-associated Salmonella outbreaks of human disease.


Assuntos
Surtos de Doenças , Ovos/microbiologia , Microbiologia de Alimentos , Gastroenterite/epidemiologia , Intoxicação Alimentar por Salmonella/epidemiologia , Salmonella/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Gastroenterite/microbiologia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Intoxicação Alimentar por Salmonella/microbiologia , Austrália do Sul/epidemiologia , Adulto Jovem
12.
Talanta ; 201: 126-133, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31122402

RESUMO

Upconversion nanoparticle-based lateral flow assays (UCNP-LFAs) have attracted significant attention in point-of-care testing (POCT) applications, due to the long-term photostability and enhanced signal-to-background noise ratio. The existing UCNP-LFAs generally require peripheral equipment for exciting fluorescent signals and reading out fluorescence results, which are generally bulky and expensive. Herein, we developed a miniaturized and portable UCNP-LFA platform, which is composed of a LFA detection system, an UCNP-LFA reader and a smartphone-assisted UCNP-LFA analyzer. The LFA detection system is based on three types of UCNPs for multiplexed detection. The reader has a dimension of 24.0 cm × 9.4 cm × 5.4 cm (L × W × H) and weight of 0.9 kg. The analyzer based on the custom-designed software of a smartphone (termed as UCNP-LFA analyzer) can get the quantitative analysis results in a real-time manner. We demonstrated the universality of this platform by highly sensitive and quantitative detections of several kinds of targets, including small molecule (ochratoxin A, OTA), heavy metal ion (Hg2+), bacteria (salmonella, SE), nucleic acid (hepatitis B virus, HBV) and protein (growth stimulation expressed gene 2, ST-2). Our developed UCNP-LFA platform holds great promise for applications in disease diagnostics, environmental pollution monitoring and food safety at the point of care.


Assuntos
Imunoensaio/métodos , Nanopartículas/química , Testes Imediatos , Anticorpos/química , Biomarcadores/sangue , DNA/análise , DNA/química , DNA/genética , Érbio/química , Fluoretos/química , Fluoretos/efeitos da radiação , Vírus da Hepatite B/genética , Humanos , Imunoensaio/instrumentação , Proteína 1 Semelhante a Receptor de Interleucina-1/sangue , Proteína 1 Semelhante a Receptor de Interleucina-1/imunologia , Limite de Detecção , Mercúrio/análise , Nanopartículas/efeitos da radiação , Hibridização de Ácido Nucleico , Salmonella/isolamento & purificação , Smartphone , Espectrometria de Fluorescência/métodos , Itérbio/química , Ítrio/química , Ítrio/efeitos da radiação
13.
Food Chem ; 294: 468-476, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126489

RESUMO

Detection of pathogenic bacteria by polymerase chain reaction (PCR) is progressively emerging, although it is still hindered by a complex matrix, long-term bacterial enrichment and low bacterial abundance. Here, we report a novel material based on boronate affinity for recognition and enrichment of bacteria using a pre-PCR method. After optimization, the material exhibited high boronate affinity toward bacteria, with adsorption capacities of S. aureus and Salmonella spp. incubated in 0.01 M PBS (pH 7.4) at 37 °C for 15 min calculated as (906.60 ±â€¯15.73) × 107 cfu/g and (582.59 ±â€¯13.19) × 107 cfu/g, respectively, without any bacterial death during the binding process. The material was then applied to enrich S. aureus and Salmonella spp. from the spiked water and 25% cow milk samples followed by mPCR, which resulted in high bacterial enrichment and demonstrated great potential for selective enrichment of bacteria in food samples.


Assuntos
Compostos de Boro/química , Microbiologia de Alimentos/métodos , Salmonella/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Adsorção , Animais , Compostos de Boro/síntese química , Bovinos , Água Potável/microbiologia , Doenças Transmitidas por Alimentos/microbiologia , Concentração de Íons de Hidrogênio , Leite/microbiologia , Polietilenoimina/química , Reação em Cadeia da Polimerase , Salmonella/genética , Sensibilidade e Especificidade , Sefarose/química , Staphylococcus aureus/genética
14.
Lett Appl Microbiol ; 69(2): 116-120, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31124146

RESUMO

The National Antimicrobial Resistance Monitoring System for Enteric Bacteria retail food surveillance programme screens retail meat samples for the presence of Salmonella spp. to track antimicrobial resistance in food. In this study, a laboratory developed real-time PCR assay that detects Salmonella spp. was evaluated as a screening method to replace the discountinued 3M TECRA kit. The 3M TECRA kit was a commercially available, visual immunoassay used to screen food samples for the presence of Salmonella spp. This kit was discontinued in September 2016 by the manufacturer and an alternative screening method was needed to replace the discontinued TECRA kit. Salmonella spp. is detected by the real-time PCR assay earlier in the screening process than by the TECRA kit. Salmonella spp. can also be reliably isolated from the enrichment broth earlier in the protocol. Additionally, cost analysis shows that the real-time PCR assay saves $2·50 per sample. New York State Department of Health currently uses this real-time PCR assay as a screening method for the presence of Salmonella spp. in retail meat samples. The assay allows for continued monitoring of antimicrobial resistance in Salmonella spp., while providing a cost savings and a decrease in turnaround time. SIGNIFICANCE AND IMPACT OF THE STUDY: The National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS) tracks antimicrobial susceptibility of enteric bacteria in people, food and animals (https://www.fda.gov/animalveterinary/safetyhealth/antimicrobialresistance/nationalantimicrobialresistancemonitoringsystem/). The New York State Department of Health (NYSDOH) became a NARMS retail food surveillance (RFS) site in 2003. The NARMS-RFS programme screens retail meat samples from grocery stores in the United States for the presence of Salmonella spp. and other enteric pathogens to monitor the prevalence of antimicrobial resistance among these pathogens. The NYSDOH developed a rapid and cost-effective real-PCR assay to screen for Salmonella spp. in retail meat products.


Assuntos
Farmacorresistência Bacteriana , Microbiologia de Alimentos , Produtos da Carne/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções por Salmonella/microbiologia , Salmonella/isolamento & purificação , Animais , Monitoramento Epidemiológico , Humanos , Saúde Pública , Reação em Cadeia da Polimerase em Tempo Real/economia , Reprodutibilidade dos Testes , Salmonella/efeitos dos fármacos , Salmonella/genética , Infecções por Salmonella/prevenção & controle , Estados Unidos/epidemiologia
16.
Arq. bras. med. vet. zootec. (Online) ; 71(2): 687-695, mar.-abr. 2019. tab, ilus
Artigo em Português | LILACS, VETINDEX | ID: biblio-1011277

RESUMO

O objetivo do presente trabalho foi desenvolver a carne de bijupirá defumada, assim como avaliar o rendimento, a qualidade bacteriológica, a composição centesimal e a aceitabilidade do produto. Análises microbiológicas de pesquisa de Salmonella sp. e contagens de Staphylococcus aureus, coliformes totais e Escherichia coli foram realizadas. Foi determinada a composição centesimal e realizado o teste de aceitação do produto. O rendimento médio da carne após a salga foi de 83,41%, com base no peso do charuto. A análise microbiológica da carne defumada apresentou-se positiva em apenas uma amostra para Staphylococcus aureus e negativa para as demais bactérias. O produto possui boa qualidade nutricional e alcançou 97% de aceitação para o aspecto global, atingindo média de 6,26 (± 0,99). A carne de bijupirá defumada obteve condições higiênico-sanitárias satisfatórias, boa qualidade nutricional, além de alto índice de aceitação sensorial, destacando-se os atributos textura e sabor. Evidenciou-se, assim, que esse tipo de processo pode ser realizado em escala artesanal ou industrial.(AU)


The objective of the study was to develop the smoked cobia meat and to evaluate the yield, the bacteriological quality, the centesimal composition, and the acceptability of the product. Microbiological analysis of Salmonella sp. and Staphylococcus aureus, total coliforms and Escherichia coli counts were performed. The centesimal composition was determined and the acceptance test was performed. The average yield of the product after salting was 83.41% based on the fish roll weight. The microbiological analysis of the smoked meat showed positive in only one sample for Staphylococcus aureus and negative for the other bacteria. The product has a good nutritional quality and was accepted obtaining 97% for the overall aspect, average of 6.26 (± 0.99). The smoked cobia meat obtained satisfactory hygienic-sanitary conditions, good nutritional quality, besides a high index of sensorial acceptance emphasizing the texture and flavor attributes. Smoked process can be easily carried out on an artisanal or industrial scale.(AU)


Assuntos
Animais , Salmonella/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Colimetria , Produtos Pesqueiros/microbiologia , Peixes , Conservação de Alimentos
17.
J Microbiol Biotechnol ; 29(3): 454-464, 2019 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-30939631

RESUMO

Salmonellosis is a highly contagious bacterial disease that threatens both human and poultry health. Tests that can detect Salmonella in the field are urgently required to facilitate disease control and for epidemiological investigations. Here, we combined loop-mediated isothermal amplification (LAMP) with a chromatographic lateral flow dipstick (LFD) to rapidly and accurately detect Salmonella. LAMP primers were designed to target the Salmonella invA gene. LAMP conditions were optimized by adjusting the ratio of inner to outer primers, MgSO4 concentration, dNTP mix concentration, amplification temperature, and amplification time. We evaluated the specificity of our novel LAMP-LFD method using six Salmonella species and six related non-Salmonella strains. All six of the Salmonella strains, but none of the non-Salmonella strains, were amplified. LAMP-LFD was sensitive enough to detect concentrations of Salmonella enterica subsp. enterica serovar Pullorum genomic DNA as low as 89 fg/µl, which is 1,000 times more sensitive than conventional PCR. When artificially contaminated feed samples were analyzed, LAMP-LFD was also more sensitive than PCR. Finally, LAMP-LFD gave no false positives across 350 chicken anal swabs. Therefore, our novel LAMP-LFD assay was highly sensitive, specific, convenient, and fast, making it a valuable tool for the early diagnosis and monitoring of Salmonella infection in chickens.


Assuntos
Galinhas/microbiologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Doenças das Aves Domésticas/diagnóstico , Salmonella/isolamento & purificação , Ração Animal/microbiologia , Animais , Proteínas de Bactérias/genética , China , Cromatografia/métodos , Primers do DNA , DNA Bacteriano/análise , DNA Bacteriano/genética , Humanos , Reação em Cadeia da Polimerase/métodos , Doenças das Aves Domésticas/microbiologia , Kit de Reagentes para Diagnóstico , Salmonella/genética , Salmonella/patogenicidade , Salmonella enterica/genética , Salmonella enterica/isolamento & purificação , Salmonella enterica/patogenicidade , Sensibilidade e Especificidade , Fatores de Tempo
18.
Int J Food Microbiol ; 299: 1-7, 2019 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-30933685

RESUMO

Salmonella is a common foodborne pathogen in the poultry production systems. Its presence in this food industry is determined by the fact that it can survive and pass throughout the different steps in the poultry production. In this study we aimed to study the occurrence, genotypes and antimicrobial resistance of Salmonella collected from the broiler production chain within an integrated poultry company. Three hundred fourteen samples were collected in the feeding plant, farms and the slaughterhouse. Samples were cultured for Salmonella isolation according to the ISO6579/Amd 1. Isolates were further typed by Kauffmann-White scheme and pulse field gel electrophoresis (PFGE). Antimicrobial resistance to 11 antimicrobials was studied by disk diffusion tests and sequencing of ESBL genes. From the collected samples 70 (22%) were found to be Salmonella positive. The lowest Salmonella rates were found in feed samples while in farm and slaughterhouse samples Salmonella presence ranged from 5% to 88%. S. Infantis was the most common serotype (94%, 66/70). PFGE demonstrated that isolates belonged to 11 genotypes. Some genotypes were continuously identified throughout the production chain. 97% of the isolates showed resistance to at least one antimicrobial. Moreover, all S. Infantis isolates and one auto-agglutinable isolate showed resistance to at least 6 antimicrobials. 30 and 8 isolates were positive to blaCTX-M-65 and blaCTX-M-14 genes respectively. No blaKPC resistance genes were identified in any isolate. This study highlights the predominance of S. Infantis in the integrated poultry company. Genotypes showed that cross-contamination between stages of poultry production can occur, stressing the importance of implementing good hygiene practices in every level of the production. Moreover, multidrug resistance patterns and the presence of important ESBL genes have public health implications that need to be deeply discussed with a one health approach.


Assuntos
Matadouros , Anti-Infecciosos/farmacologia , Fazendas , Microbiologia de Alimentos , Abrigo para Animais , Salmonella/efeitos dos fármacos , Salmonella/genética , Ração Animal/microbiologia , Animais , Genótipo , Testes de Sensibilidade Microbiana , Aves Domésticas/microbiologia , Salmonella/isolamento & purificação
19.
PLoS Negl Trop Dis ; 13(4): e0007293, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30986214

RESUMO

Non-typhoidal Salmonella (NTS) bacteremia is a significant cause of morbidity and mortality worldwide. It is considered to be an emerging and neglected tropical disease in Africa. We studied this in two tertiary hospitals-Al Farwaniya and Al Amiri-in Kuwait, a subtropical country, from April 2013-May 2016. NTS bacteremia was present in 30 of 53,860 (0.75%) and 31 of 290,36 (1.33%) blood cultures in the two hospitals respectively. In Al Farwaniya hospital, one-third of the patients were from some tropical developing countries of Asia. About 66% of all patients (40/61) had diarrhea, and of these, 65% had the corresponding blood serovar isolated from stool culture. A few patients had Salmonella cultured from urine. Patients were either young or old. Most of the patients had co-morbidities affecting the immune system. Two patients each died in both hospitals. The number of different serovars cultured in each hospital was 13, and most infections were due to S. Enteritidis (all sequence type [ST]) 11) and S. Typhimurium (all ST19) except in a subgroup of expatriate patients from tropical developing countries in Al Farwaniya hospital. About a quarter of the isolates were multidrug-resistant. Most patients were treated with a cephalosporin with or without other antibiotics. S. Enteritidis and S. Typhimurium isolates were typed by pulsed field-gel electrophoresis (PFGE) and a selected number of isolates were whole-genome sequenced. Up to four different clades were present by PFGE in either species. Whole-genome sequenced isolates showed antibiotic-resistance genes that showed phenotypic correlation, and in some cases, phenotypes showed absence of specific genes. Whole-genome sequenced isolates showed presence of genes that contributed to blood-stream infection. Phylogeny by core genome analysis showed a close relationship with S. Typhimurium and S. Enteritidis from other parts of the world. The uniqueness of our study included the finding of a low prevalence of infection, mortality and multidrug-resistance, a relatively high prevalence of gastrointestinal infection in patients, and the characterization of selected isolates of S. Typhimurium and S. Enteritidis serovars by whole-genome sequencing that shed light on phylogeny, virulence and resistance. Similarities with studies from developing countries especially Africa included infection in patients with co-morbidities affecting the immune system, predominance of S. Typhimurium and S. Enteritidis serovars and presence of drug-resistance in isolates.


Assuntos
Bacteriemia/microbiologia , Bacteriemia/patologia , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologia , Salmonella/classificação , Salmonella/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/uso terapêutico , Bacteriemia/epidemiologia , Sangue/microbiologia , Pré-Escolar , Farmacorresistência Bacteriana , Fezes/microbiologia , Feminino , Genótipo , Humanos , Lactente , Kuweit/epidemiologia , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem Molecular , Prevalência , Infecções por Salmonella/epidemiologia , Sorogrupo , Centros de Atenção Terciária , Urina/microbiologia , Sequenciamento Completo do Genoma , Adulto Jovem
20.
Zoonoses Public Health ; 66(4): 406-416, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30985994

RESUMO

The role of free-ranging wildlife in the epidemiology of enteropathogens causing clinical illness in humans and domestic animals is unclear. Salmonella enterica and anti-microbial resistant bacteria have been detected in the faeces of raccoons (Procyon lotor), but little is known about the carriage of these bacteria in other sympatric meso-mammals. Our objectives were to: (a) report the prevalence of Salmonella and associated anti-microbial resistance, Campylobacter spp, Clostridium difficile, and anti-microbial resistant Escherichia coli in the faeces of striped skunks (Mephitis mephitis) and Virginia opossums (Didelphis virginiana) in southern Ontario; and (b) compare the prevalence of these bacteria in the faeces of these meso-mammal hosts with raccoons from a previously reported study. Faecal swabs were collected from striped skunks and Virginia opossums on five swine farms and five conservation areas from 2011 to 2013. Salmonella was detected in 41% (9/22) and 5% (5/95) of faecal swabs from Virginia opossums and striped skunks, respectively. None of the Salmonella serovars carried resistance to anti-microbials. The prevalence of Campylobacter spp., C. difficile, and anti-microbial resistant E. coli ranged from 6% to 22% in striped skunk and Virginia opossums. Using exact logistic regression, Salmonella was significantly more likely to be detected in faecal swabs of Virginia opossums than skunks and significantly less likely in faecal swabs from skunks than raccoons from a previously reported study. In addition, Campylobacter spp. was significantly more likely to be detected in raccoons than opossums. Salmonella Give was detected in 8/9 (89%) of Salmonella-positive Virginia opossum faecal swabs. Our results suggest that striped skunks and Virginia opossums have the potential to carry pathogenic enteric bacteria in their faeces. The high prevalence of Salmonella Give in Virginia opossum faecal swabs in this study as well as its common occurrence in other Virginia opossum studies throughout North America suggests Virginia opossums may be reservoirs of this serovar.


Assuntos
Animais Selvagens/microbiologia , Infecções por Campylobacter/veterinária , Infecções por Clostridium/veterinária , Reservatórios de Doenças/veterinária , Infecções por Escherichia coli/veterinária , Fezes/microbiologia , Salmonelose Animal/epidemiologia , Animais , Campylobacter/isolamento & purificação , Infecções por Campylobacter/epidemiologia , Infecções por Clostridium/epidemiologia , Clostridium difficile/isolamento & purificação , Reservatórios de Doenças/microbiologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Fazendas , Feminino , Masculino , Mephitidae/microbiologia , Ontário/epidemiologia , Gambás/microbiologia , Prevalência , Guaxinins/microbiologia , Salmonella/isolamento & purificação , Salmonelose Animal/transmissão
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