Direct detection of Salmonella without pre-enrichment in milk, ice-cream and fruit juice by PCR against hilA gene

Marathe, Sandhya Amol; Chowdhury, Rebecca; Bhattacharya, Rahul; Nagarajan, Arvindhan; Chakravortty, Dipshikha

doi:10.1016/j.foodcont.2011.08.005

Cited by 24 publications

(14 citation statements)

References 40 publications

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“…Two 0.45 µm filters were used; one was placed onto xylose lysine deoxycholate agar (XLD) (Biorad, South Africa) and/ or Salmonella-Shigella agar (SS) (Merck, South Africa) and incubated at a temperature of 37°C for 24 h under aerobic conditions, and the other was preserved in 1 mL of 15% glycerol at 0°C for genetic analysis. Since the desired counts required were of the actual water and sediment samples, no enrichment step was needed to enhance and multiply the initial bacterial counts, as also performed by Wolffs et al (2006) and Marathe et al (2012). The abundance of cultured Salmonella spp.…”

Section: Sample Collectionmentioning

confidence: 99%

Genetic characterization of Salmonella and Shigella spp. isolates recovered from water and riverbed sediment of the Apies River, South Africa

Ekwanzala

Abia

Keshri

et al. 2017

WSA

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Riverbed sediment is a vital component of river ecosystems and plays an important role in many geomorphological and ecological processes. However, when re-suspension occurs, pathogenic bacteria associated with sediment particles may be released into the water column, thus creating a health risk to those who use such water for drinking, household and recreational purposes. The aim of this study was to investigate the presence of bacterial pathogens Salmonella spp. and Shigella spp. in the Apies River and to ascertain whether there was any level of genetic relatedness between river water and riverbed sediment isolates of these pathogenic bacteria. A total of 124 water and sediment samples were collected from a site located on the Apies Rivers upstream of the Daspoort Wastewater Treatment Works, Pretoria, Gauteng, South Africa, between August and November 2014. In order to detect and identify the target bacteria, samples were analysed by culture-dependent and culture-independent techniques (quantitative real-time PCR). Genetic relatedness was established using Sanger sequencing of the invA gene of Salmonella spp. and ipaH of Shigella spp. Results of this study displayed the presence of the target bacteria both in the water and sediment of the river. The phylogenetic tree of Salmonella spp. revealed a ≥ 99% and 99% genetic relatedness between river water and riverbed sediment isolates for Salmonella spp. and Shigella spp., respectively. The degree of genetic relatedness between sediment and water pathogen isolates suggests that these organisms could possibly have a common origin and that there could be possible movement of microorganisms between the water column and the sediments.

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Section: Sample Collectionmentioning

confidence: 99%

Genetic characterization of Salmonella and Shigella spp. isolates recovered from water and riverbed sediment of the Apies River, South Africa

Ekwanzala

Abia

Keshri

et al. 2017

WSA

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“…Also reported is a protocol for detection without pre-enrichment using primers directed to the hilA gene that is able to detect up to 5 bacteria/ml in milk samples (18) . A sensitivity of 1-10 CFU/ml has been obtained with a pre-enrichment period of 18 h in tryptone soya broth (16) .…”

Section: Literatura Citadamentioning

confidence: 99%

“…The 12 h pre-enrichment period in 1% BPW used ensures detection of up to 1 CFU/25 ml of milk, which is already beyond the detection limits previously detected for endpoint PCR assays. Other work has used centrifugation for recovering the bacterial pellet and a treatment with EDTA and TritonX-100 for elimination of lipids and proteins that inhibit PCR (18) , a procedure that was unnecessary in this work.…”

Section: Literatura Citadamentioning

confidence: 99%

“…También se ha notificado un protocolo de detección sin enriquecimiento, en el cual es posible detectar hasta 5 bacterias/ml en muestras de leche empleando iniciadores dirigidos al gen hilA (18) . La sensibilidad de 1-10 UFC/ml se ha obtenido con un preenriquecimiento 18 h en caldo de soya y triptona (16) .…”

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“…Previously reported sensitivities for other y un tratamiento con EDTA y TritónX-100 para eliminar grasas y proteínas que inhiben la PCR (18) , lo cual no fue necesario en el presente trabajo.…”

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A multiplex PCR assay for detection of genus Salmonella, subspecies I , and serotype Typhimurium in milk

Vázquez-Garcidueñas

Meléndez-Ceja

Vázquez-Marrufo

2015

Rev. Mex. Cienc. Pecu.

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RESUMENDebido a la importancia social y económica de las enfermedades gastrointestinales causadas por alimentos contaminados con Salmonella enterica, es necesario contar con sistemas de detección rápidos, sensibles y específicos para la detección oportuna de dicho patógeno. En este trabajo se presenta un protocolo de PCR de punto final para la identificación de S. enterica en leche, que utiliza los pares de iniciadores STM3098-f2/STM3098-r2, STM4057-f/STM4057-r y STM4497-f/STM4497-r previamente validados como específicos del género Salmonella, de la subespecie I y del serotipo Typhimurium, respectivamente. El protocolo presentado permite la detección de 1 UFC/25 ml de leche contaminada artificialmente, con un periodo de pre-enriquecimiento de 12 h, en ensayos de PCR simple y multiplex con los tres pares de iniciadores. El protocolo diseñado puede ser aplicado en sistemas de vigilancia sanitaria para la detección de S. enterica en leche. PALABRAS CLAVE: Salmonella enterica, Leche, PCR multiplex. ABSTRACTGastrointestinal diseases caused by foodstuffs contaminated with Salmonella enterica implicate important social and economic issues, making it necessary to have fast, sensitive, and specific systems for opportune detection of the pathogen. An endpoint PCR protocol for identification of S. enterica in milk is presented using primer pairs previously validated as specific to the genus Salmonella (STM3098-f2/STM3098-r2), subspecies enterica (subspecies I) (STM4057-f/STM4057-r), and serotype Typhimurium (STM4497-f/ STM4497-r). This protocol allowed for detection of 1 CFU/25 mL of spiked milk after a 12 h pre-enrichment period by means of simple and multiplex PCR assay with the three used primer pairs. The designed protocol can be applied in sanitary survey programs for detection of S. enterica in milk.

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Insights into Detection and Identification of Foodborne Pathogens

Law

Letchumanan

Chan

et al. 2016

Foodborne Pathogens and Antibiotic Resistance

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Direct detection of Salmonella without pre-enrichment in milk, ice-cream and fruit juice by PCR against hilA gene

Cited by 24 publications

References 40 publications

Genetic characterization of <i>Salmonella</i> and <i>Shigella</i> spp. isolates recovered from water and riverbed sediment of the Apies River, South Africa

Genetic characterization of <i>Salmonella</i> and <i>Shigella</i> spp. isolates recovered from water and riverbed sediment of the Apies River, South Africa

A multiplex PCR assay for detection of genus Salmonella, subspecies I , and serotype Typhimurium in milk

Insights into Detection and Identification of Foodborne Pathogens

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