Molecular Characterization of Listeria monocytogenes in white meat samples from Punjab, India

2017 ◽  
Author(s):  
Simranpreet Kaur ◽  
Randhir Singh ◽  
Mandeep Kaur Sran ◽  
J.P. S. Gill
Keyword(s):  
Public Health ◽  
Listeria Monocytogenes ◽  
White Meat ◽  
Selective Enrichment ◽  
Retail Outlets ◽  
Meat Samples ◽  
Pcr Targeting ◽  
University Of Vermont

A study was undertaken to assess the prevalence of Listeria monocytogenes in white meats in the Punjab, India. A total of 335 samples including 115 samples of chicken, 75 samples of pork and 145 samples of fish were collected from retail outlets. Isolation of the pathogen was done by selective enrichment in University of Vermont Medium I and II and plating onto PALCAM agar. The recovered Listeria isolates were subjected to in-vitro pathogenicity assays and multiplex PCR targeting virulence-associated genes (prfA, plcA, actA, hlyA and iap) of L. monocytogenes. A total of thirty one (31) L. monocytogenes strains were isolated from meat samples with the prevalence of L. monocytogenes as 9.2%. Maximum prevalence was seen in fish (19.3%) followed by chicken (1.7%) and pork (1.3%). All isolates recovered from the study exhibited pathogenicity in in-vitro pathogenicity assays as well as possessed all the virulence related genes. Thus, the presence of pathogenic strains of L. monocytogenes in white meats with a prevalence of 9.2% appeared to be a cause for concern with profound public health implications.

Delivery of Selective Agents via Time-Delayed Release Tablets Improves Recovery of Listeria monocytogenes Injured by Acid and Nitrite

2014 ◽  
Vol 77 (5) ◽  
pp. 772-780 ◽  
Author(s):  
ESMOND NYARKO ◽  
DENNIS D'AMICO ◽  
PATRICK MACH ◽  
WENSHENG XIA ◽  
CATHERINE DONNELLY
Keyword(s):  
Listeria Monocytogenes ◽  
Cell Populations ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Delayed Release ◽  
Selective Agents ◽  
Meat Samples ◽  
Food Sample Analysis ◽  
University Of Vermont ◽  
The U.S

Listeria selective enrichment media are designed to enhance the isolation of the organism and increase the chances of detection. Drawbacks include the requirements for prolonged sample incubation (48 to 72 h) and manual addition of selective agents, which may be a source of contamination. Modified Listeria recovery broth (mLRB) is a proprietary enrichment medium formulated to facilitate the recovery of injured cells; its selective agents are incorporated into a format that allows delayed release until 6 h of incubation. We evaluated the change in cell populations over time for acid- and nitrite-injured Listeria monocytogenes in mLRB with the selective agents added manually at 0 h (mLRBS0) and 6 h (mLRBS6). Recovery of injured cells in mLRB plus time-delayed tablets (mLRBTD) was also compared with that in enrichment media recommended by the U.S. Department of Agriculture (University of Vermont broth), the U.S. Food and Drug Administration (buffered Listeria enrichment broth), and the International Organization for Standardization (demi-Fraser broth). Nitrite- or acid-injured Listeria at approximately 10 CFU/ml were inoculated into each broth medium, and Listeria populations were enumerated at various times from 12 to 48 h of incubation at 37°C. Analysis of variance revealed that acid-injured Listeria populations in mLRBS6 at 24 h were significantly higher (P < 0.05) than those in mLRBS0; however, the differences in populations on these two media were not significant for nitrite-injured cells. Cell populations of four strains of Listeria inoculated into mLRBTD were significantly higher at 24 h than when those strains were enriched in buffered Listeria enrichment broth, demi-Fraser broth, and University of Vermont broth. Comparison between artificially contaminated milk and meat samples with a four-strain cocktail of Listeria resulted in cell populations that were significantly higher (P < 0.05) at 24 h on mLRBTD for contaminated meat than on mLRB for contaminated milk. Delivery of selective agents via time-delayed release tablets into mLRB maximizes recovery of acid- and nitrite-injured Listeria and saves analyst time during food sample analysis.

scholarly journals High Prevalence of yadA-Positive Yersinia enterocolitica in Pig Tongues and Minced Meat at the Retail Level in Finland

1999 ◽  
Vol 62 (2) ◽  
pp. 123-127 ◽  
Author(s):  
MARIA FREDRIKSSON-AHOMAA ◽  
SEBASTIAN HIELM ◽  
HANNU KORKEALA
Keyword(s):  
Yersinia Enterocolitica ◽  
Culture Method ◽  
Selective Enrichment ◽  
Conventional Culture ◽  
High Prevalence ◽  
Retail Outlets ◽  
Polymerase Chain ◽  
Meat Samples ◽  
Minced Meat ◽  
Conventional Culture Method

Polymerase chain reaction (PCR) was used to determine the prevalence of yadA-positive Yersinia enterocolitica in pig tongues and minced meat at the retail level in Finland and to confirm the yadA-positive Y. enterocolitica isolates recovered from the same samples using the conventional culture method. A total of 51 pig tongues purchased at 12 retail outlets and 255 minced meat samples purchased at 40 retail outlets in the Helsinki area were studied. The prevalence of Y. enterocolitica carrying the yadA gene was 92% in pig tongues and 25% in minced meat using PCR and 78% in tongues and 2% in minced meat with the culture method. The prevalence of yadA-positive tongues was higher (98%) when both PCR- and culture-positive results were included because Y. enterocolitica carrying the yadA gene could also be isolated in three PCR-negative tongue samples. In the minced meat samples, all PCR-negative samples were also culture-negative. With the culture method, 66 of 80 yadA-positive isolates in 38 tongues and all yadA-positive isolates (4) in four minced meat samples were recovered after selective enrichment. A total of 92 isolates of Y. enterocolitica bioserotype 4/O:3 in tongues and 5 isolates in minced meat were found, of which 13% in tongues and 20% in minced meat did not carry the yadA gene.

scholarly journals Occurrence and antimicrobial susceptibility of Salmonella isolates from grilled chicken meat sold at retail outlets in Erbil City, Kurdistan region, Iraq

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Dhary A. Almashhadany
Keyword(s):  
Public Health ◽  
Health Hazard ◽  
Public Health Problem ◽  
Chicken Meat ◽  
Major Public Health Problem ◽  
Antibiotic Resistance Profile ◽  
Retail Outlets ◽  
Disk Diffusion Assay ◽  
Antibiotics Sensitivity ◽  
Meat Samples

Food borne salmonellosis is a major public health problem worldwide. This study aimed to detect the occurrence and antibiotics sensitivity of Salmonella species in grilled chicken meat sold at retail outlets in Erbil City, Kurdistan, Iraq. Two hundred and twenty-five (225) samples were aseptically collected from central and suburb retail outlets. For isolation of salmonellae, samples were cultured on selective media and tested for their susceptibility to common antibiotics by disk diffusion assay. The results revealed that the overall prevalence of Salmonella among grilled chicken meat samples was 7.1%. The isolates belonged to eight different serotypes of Salmonella. These include S. Typhimurium, S. Tennessee, S. Newport, S. Enteritidis, S. Anatum, S. Arizona, S. Muenchen, and S. Montevideo. The antibiotic resistance profile revealed a total resistance to Levofloxacin and total sensitivity to Cefotaxime, Amoxicillin, and Cefadroxil. This resistance among Salmonella may pose a public health hazard that requires effective precautions and response.

Quantitative Evaluation of Three Selective Enrichment Broths and Agars Used in Recovering Listeria Microorganisms

1990 ◽  
Vol 53 (2) ◽  
pp. 105-110 ◽  
Author(s):  
JOSE FERNANDEZ-GARAYZABAL ◽  
CONSTANTIN GEMGEORGIS
Keyword(s):  
Brain Heart Infusion ◽  
Superior Performance ◽  
Enrichment Broth ◽  
Selective Enrichment ◽  
Naturally Occurring ◽  
Listeria Ivanovii ◽  
Soft Cheese ◽  
Meat Samples ◽  
Listeria Seeligeri ◽  
University Of Vermont

Three selective enrichment broths (FDA, University of Vermont and Dominguez Rodriguez) and lithium chloride-phenylethanol-moxolactam (LPM) agar, modified McBride (MMA) agar, Listeria selective agar (LSAM of Dominguez-Rodriguez), and Brain Heart Infusion (BHI) agar (as reference) were evaluated for their suitability to support the growth of six different species/strains of Listeria (Listeria monocytogenes Scott A, L. monocytogenes V7, L. monocytogenes VPH-1, Listeria innocua, Listeria seeligeri, and Listeria ivanovii). All Listeria strains grew faster and yielded a higher number of cells in FDA enrichment broth. Based on MPN studies, 1 to 2.1 cells of L. monocytogenes and L. innocua were needed for visible colony formation, on all three selective and BHI agars after 48 h incubation of 37°C. The LPM agar was more inhibitory for L. seeligeri and L. ivanovii requiring 9.6 and 917 cells, respectively, as compared to 1 to 2.7 cells for the other agars. The effectiveness of a particular combination among the selective enrichment broths and agars for recovering L. monocytogenes Scott A from inoculated cheese and meat samples was quantitated. Any enrichment broth combined with plating on LPM or LSAM agar gave 100% Listeria recovery as compared to 50 to 67% for plating on MMA agar. Both LPM and LSAM agars have also shown a superior performance to MMA agar in the recovery of naturally occurring Listeria from soft cheese and raw meat. The use of a secondary broth enrichment step improved the recovery of Listeria spp. from meat samples.

Selective enrichment and biochemical characterization of seven human skin fibroblasts cell types in vitro

1989 ◽  
Vol 180 (1) ◽  
pp. 84-93 ◽  
Author(s):  
H.Peter Rodemann ◽  
Klaus Bayreuther ◽  
Pal I. Francz ◽  
Klaus Dittmann ◽  
Mario Albiez
Keyword(s):  
Human Skin ◽  
Biochemical Characterization ◽  
Cell Types ◽  
Skin Fibroblasts ◽  
Human Skin Fibroblasts ◽  
Selective Enrichment

scholarly journals Bias in the Listeria monocytogenes Enrichment Procedure: Lineage 2 Strains Outcompete Lineage 1 Strains in University of Vermont Selective Enrichments

2005 ◽  
Vol 71 (2) ◽  
pp. 961-967 ◽  
Author(s):  
Jesper Bartholin Bruhn ◽  
Birte Fonnesbech Vogel ◽  
Lone Gram
Keyword(s):  
Growth Rate ◽  
Listeria Monocytogenes ◽  
Brain Heart Infusion ◽  
Selective Medium ◽  
Individual Growth ◽  
Selective Enrichment ◽  
Enrichment Procedure ◽  
True Representation ◽  
Lineage 2 ◽  
University Of Vermont

ABSTRACT Listeria monocytogenes can be isolated from a range of food products and may cause food-borne outbreaks or sporadic cases of listeriosis. L. monocytogenes is divided into three genetic lineages and 13 serotypes. Strains of three serotypes (1/2a, 1/2b, and 4b) are associated with most human cases of listeriosis. Of these, strains of serotypes 1/2b and 4b belong to lineage 1, whereas strains of serotype 1/2a and many other strains isolated from foods belong to lineage 2. L. monocytogenes is isolated from foods by selective enrichment procedures and from patients by nonselective methods. The aim of the present study was to investigate if the selective enrichment procedure results in a true representation of the subtypes of L. monocytogenes present in a sample. Eight L. monocytogenes strains (four lineage 1 strains and four lineage 2 strains) and one Listeria innocua strain grew with identical growth rates in the nonselective medium brain heart infusion (BHI), but differed in their growth rate in the selective medium University of Vermont medium I (UVM I). When coinoculated in UVM I, some strains completely outgrew other strains. This outcome was dependent on the lineage of L. monocytogenes rather than the individual growth rate of the strains. When inoculated at identical cell densities in UVM I, L. innocua outcompeted L. monocytogenes lineage 1 strains but not lineage 2 strains. In addition, lineage 2 L. monocytogenes strains outcompeted lineage 1 L. monocytogenes strains in all combinations tested, indicating a bias in strains selected by the enrichment procedures. Bias also occurred when coinoculating two lineage 2 or lineage 1 strains; however, it did not appear to correlate with origin (clinical versus food). Identical coinoculation experiments in BHI suggested that the selective compounds in UVM I and II influenced this bias. The results of the present study demonstrate that the selective procedures used for isolation of L. monocytogenes may not allow a true representation of the types present in foods. Our results could have a significant impact on epidemiological studies, as lineage 1 strains, which are often isolated from clinical cases of listeriosis, may be suppressed during enrichment by other L. monocytogenes lineages present in a food sample.

scholarly journals Human Clade 2.3.4.4 A/H5N6 Influenza Virus Lacks Mammalian Adaptation Markers and Does Not Transmit via the Airborne Route between Ferrets

mSphere ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Sander Herfst ◽  
Chris K. P. Mok ◽  
Judith M. A. van den Brand ◽  
Stefan van der Vliet ◽  
Miruna E. Rosu ◽  
...  
Keyword(s):  
Public Health ◽  
Genetic Diversity ◽  
Influenza A ◽  
Severe Disease ◽  
Risk Assessments ◽  
Influenza A Viruses ◽  
Species Barrier ◽  
Public Health Threat

Avian influenza A viruses are a threat to human health, as they cross the species barrier and infect humans occasionally, often with severe outcome. The antigenic and genetic diversity of A/H5 viruses from the A/goose/Guangdong/1/96 lineage is increasing, due to continued circulation and reassortment in poultry, posing a constant risk for public health and requiring regular risk assessments. Here we performed an in-depth characterization of the properties of the newly emerged zoonotic A/H5N6 virusin vitroand in ferrets. The lack of airborne transmission in the ferret model indicates that A/H5N6 virus does not pose a direct public health threat, despite the fact that it can replicate to high titers throughout the respiratory tracts of ferrets and cause more severe disease than other clade 2.3.4.4 viruses.

scholarly journals Detection and Molecular Characterization of Vibrio Parahaemolyticus in Shrimp Samples

2018 ◽  
Vol 12 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Daryoush Asgarpoor ◽  
Fakhri Haghi ◽  
Habib Zeighami
Keyword(s):  
Public Health ◽  
Polymerase Chain Reaction ◽  
Vibrio Parahaemolyticus ◽  
Foodborne Diseases ◽  
Chain Reaction ◽  
Biochemical Tests ◽  
Global Issue ◽  
Retail Outlets ◽  
Polymerase Chain

Background:Food safety has emerged as an important global issue with international trade and public health implications. Bacterial pathogens asVibrio parahaemolyticusrecognized as an important cause of foodborne diseases related to the consumption of raw, undercooked or mishandled seafood worldwide.Methods:A total of 70 individual wild shrimp samples were collected from shrimp retail outlets in Zanjan, Iran and investigated for the presence of potentially pathogenic strains ofV. parahaemolyticus.The shrimp samples were immediately homogenized and cultured on TCBS agarand subjected to confirmatory biochemical tests. Polymerase Chain Reaction (PCR) was performed for detection of total and pathogenicV. parahaemolyticusby amplification ofvp–toxR,tdhandtrhgenes.Results:The conventional method indicated that 16 (22.8%) of samples were positive forV. parahaemolyticus. However, PCR verified that only 12 (17.1%) shrimp samples were positive forV. parahaemolyticus.Of the 70 shrimp samples in our study, only 2 (2.8%)tdhand 1 (1.4%)trhpositive strains were identified.Conclusion:Detection oftdhand/ ortrhpositiveV. parahaemolyticusin shrimp marketed in Zanjan, Iran shows a probable risk for public health. Therefore, the reliable molecular methods for monitoring of potentially pathogenicV. parahaemolyticusare strongly recommended for the routine seafood examination.

Prediction of Persistence of Listeria monocytogenes ST451 in a Rabbit Meat Processing Plant in the Czech Republic

2019 ◽  
Vol 82 (8) ◽  
pp. 1350-1356
Author(s):  
TEREZA GELBÍČOVÁ ◽  
MARTINA FLORIANOVÁ ◽  
ZUZANA TOMÁŠTÍKOVÁ ◽  
LUCIE POSPÍŠILOVÁ ◽  
IVANA KOLÁČKOVÁ ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Core Genome ◽  
Sequence Type ◽  
Processing Plant ◽  
Meat Processing ◽  
Sequencing Method ◽  
Serotype 1 ◽  
Rabbit Meat ◽  
Meat Samples

ABSTRACT This study was focused on characterization of the genetic diversity of Listeria monocytogenes isolated from packed fresh rabbit meat obtained from one producer via retail outlets. The partial aim was to compare the characteristics of a suspect persistent strain with strains from human cases. The occurrence of L. monocytogenes in vacuum-packed rabbit meat was monitored during 2013 to 2016. All strains were characterized by serotyping, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Selected strains, which represented each year, were analyzed using the whole genome sequencing method. L. monocytogenes was detected in 21 (38%) of 56 originally packed rabbit meat samples from one food producer during the whole monitored period. All strains showed the identical serotype (1/2a), AscI/ApaI pulsotype (735/2), and sequence type (ST451). The clonal similarity of strains from rabbit meat was also confirmed on the basis of core genome MLST (on 1,701 loci). This fact suggests the occurrence of a suspect persistent strain in the meat processing plant. Results of core genome MLST enabled us to unambiguously exclude rabbit meat as a source of listeriosis in humans caused by the indistinguishable AscI/ApaI pulsotype and sequence type, although all strains carried all genes important for the virulence of L. monocytogenes. No specific genes that may be associated with its persistence in the food processing environment were detected among the tested strains of ST451. HIGHLIGHTS

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