Genotypic characterization of Listeria monocytogenes isolated from milk and ready-to-eat indigenous milk products

Aurora, Ritu; Prakash, Alka; Prakash, Soam

doi:10.1016/j.foodcont.2008.10.017

Cited by 27 publications

(21 citation statements)

References 17 publications

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“…As serotypes 4d and 4e are relatively rare in food, the isolates belonging to 4b, 4d or 4e serogroup may be regarded as serotype 4b [9,45]. The present observations thus corroborate with those of others on the isolation of serogroup 4b from vegetable samples [27,29].…”

Section: Resultssupporting

confidence: 90%

Virulence and genotypic characterization of Listeria monocytogenes isolated from vegetable and soil samples

Soni

Singh

et al. 2014

BMC Microbiol

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BackgroundListeria monocytogenes, a foodborne pathogen is ubiquitous to different environments including the agroecosystem. The organism poses serious public health problem. Therefore, an attempt has been made to gain further insight to their antibiotic susceptibility, serotypes and the virulence genes.ResultsOut of the 10 vegetables selected, 6 (brinjal, cauliflower, dolichos-bean, tomato, chappan-kaddu and chilli), 20 isolates (10%) tested positive for L. monocytogenes. The prevalence of the pathogen in the respective rhizosphere soil samples was 5%. Noticeably, L. monocytogenes was absent from only cabbage, broccoli, palak and cowpea, and also the respective rhizospheric soils. The 30 isolates + ve for pathogenicity, belonged to serogroup 4b, 4d or 4e, and all were positive for inlA, inlC, inlJ, plcA, prfA, actA, hlyA and iap gene except one (VC3) among the vegetable isolates that lacked the plcA gene. ERIC- and REP-PCR collectively revealed that isolates from vegetables and their respective rhizospheric soils had distinct PCR fingerprints.ConclusionsThe study demonstrates the prevalence of pathogenic L. monocytogenes in the selected agricultural farm samples. The increase in the number of strains resistant to ciprofloxacin and/or cefoxitin seems to pose serious public health consequences.

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Section: Resultssupporting

confidence: 90%

Virulence and genotypic characterization of Listeria monocytogenes isolated from vegetable and soil samples

Soni

Singh

et al. 2014

BMC Microbiol

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“…Ribotyping and MLEE appear to have comparable discriminatory power, but ribotyping has been shown to have poor discriminatory power for strains belonging to serotypes 1/2b and 4b (Graves and others ). RAPD has been shown to be able to differentiate between strains belonging to the same serotype, but similar profiles were observed for strains belonging to serotypes 4b, 4d, and 4e (Aurora and others ). Both PFGE and AFLP involve the use of restriction enzymes, but PFGE has been shown to be capable of differentiating between strains belonging to serotype 4b (Whittam and Bergholz ).…”

Section: Methods Used For the Subtyping Of L Monocytogenes Strainsmentioning

confidence: 59%

“…A RAPD assay based on 3 random primers (PB1, PB4, and HLWL74) was used to show the similarity that existed between strains of L. monocytogenes isolated from beef sources in Korea and the U.S. and the same assay was used to show that a relationship existed between L. monocytogenes strains isolated from pork sources in Korea and Denmark, suggesting RAPD could be used for the molecular epidemiological characterization and source tracking of L. monocytogenes strains (Byun and others ). Although the RAPD method could successfully differentiate between L. monocytogenes strains that belonged to the same serotype, and also differentiate between L. monocytogenes strains isolated from the same source (milk and ready‐to‐eat milk products), the RAPD patterns obtained for strains that belonged to serotypes 4b, 4d, and 4e were analogous (Aurora and others ), suggesting that the RAPD assay might not be suitable for the epidemiological characterization of strains, because serotype 4b is the major serotype implicated in most epidemic outbreak of listeriosis. Although the RAPD method is simple to use, rapid, and less expensive than most methods that have been used to type isolates of L. monocytogenes , it has a lower discriminatory index than the PFGE method.…”

Section: Methods Used For the Subtyping Of L Monocytogenes Strainsmentioning

confidence: 99%

Listeria monocytogenes: Strain Heterogeneity, Methods, and Challenges of Subtyping

Nyarko

Donnelly

2015

Journal of Food Science

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Listeria monocytogenes is a food-borne bacterial pathogen that is associated with 20% to 30% case fatality rate. L. monocytogenes is a genetically heterogeneous species, with a small fraction of strains (serotypes 1/2a, 1/2b, 4b) implicated in human listeriosis. Monitoring and source tracking of L. monocytogenes involve the use of subtyping methods, with the performance of genetic-based methods found to be superior to phenotypic-based ones. Various methods have been used to subtype L. monocytogenes isolates, with the pulsed-field gel electrophoresis (PFGE) being the gold standard. Although PFGE has had a massive impact on food safety through the establishment of the PulseNet, there is no doubt that whole genome sequence (WGS) typing is accurate, has a discriminatory power superior to any known method, and allows genome-wide differences between strains to be quantified through the comparison of nucleotide sequences. This review focuses on the different techniques that have been used to type L. monocytogenes strains, their performance challenges, and the tremendous impact WGS typing could have on the food safety landscape.

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“…Effective surveillance of foodborne pathogens can be achieved through a combination of the conventional and several polymerase chain reactions (PCR)-based techniques (Loncarevic et al 2008; Aurora et al 2009; Adzitey and Corry 2011). The conventional or cultural standard methods appear to have been used since the inception of microbiological sampling (Adzitey and Huda 2010; Adzitey and Nurul 2011).…”

Section: Introductionmentioning

confidence: 99%

Molecular techniques for detecting and typing of bacteria, advantages and application to foodborne pathogens isolated from ducks

2012

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Genotypic characterization of Listeria monocytogenes isolated from milk and ready-to-eat indigenous milk products

Cited by 27 publications

References 17 publications

Virulence and genotypic characterization of Listeria monocytogenes isolated from vegetable and soil samples

Virulence and genotypic characterization of Listeria monocytogenes isolated from vegetable and soil samples

Listeria monocytogenes: Strain Heterogeneity, Methods, and Challenges of Subtyping

Molecular techniques for detecting and typing of bacteria, advantages and application to foodborne pathogens isolated from ducks

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