Identification of Listeria monocytogenes in cattle meat using biochemical methods and amplification of the hemolysin gene

A total of 30 strains of Listeria monocytogenes isolated from different foods (16 of differents kinds of sausage, 14 cheese,) purchased at groceries of São Paulo City were ribotyped and analysed for the presence and expression of hemolysin gene and production of phosphatidylinositol-specific phosphalipase C - PI-PLC enzyme. The L. monocytogenes strains were differentiated into six ribotype classes. A total of 13 (43.3%) from these strains belong to the same ribotype (ribotype I), and was coincident to the ribotype of the standard L. monocytogenes prototype strain (ATCC-15313). The hemolytic activity was observed in 29 (96.7%) strains when incubated at 37oC, but not at 4oC. The direct colony hybridization method for hemolysin gene detection showed a positive reaction whit all the 30 L. monocytogenes strains, while showed negative reaction with other Listeria spp. The PI-PLC was produced by 27 (90%) of the strains analysed. There was no correlation between the six identified ribotypes and the virulence factors (hemolysin and PI-PLC) studied.

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Identification of Listeria monocytogenes on Green Mussels (Perna viridis) and Cockle Shell (Anadara granosa)

Jurnal Pengolahan Hasil Perikanan Indonesia ◽

10.17844/jphpi.v19i3.14547 ◽

2016 ◽

Vol 19 (3) ◽

pp. 329

Author(s):

Winiati Puji Rahayu ◽

Rini Riniati ◽

Siti Nurjanah ◽

Caecillia Chrismie Nurwitri

Keyword(s):

Listeria Monocytogenes ◽

Real Time ◽

Real Time Pcr ◽

Perna Viridis ◽

Listeriolysin O ◽

Biochemical Methods ◽

Many Sources ◽

Hlya Gene ◽

Anadara Granosa ◽

Cockle Shell

Green mussel (Perna viridis) and cockle shell (Anadara granosa) are one of many sources of animal protein which is many cultivated in Indonesia because their price is relatively affordable. This study was conducted to identify the presence of Listeria monocytogenes in 27 samples of green mussels and 3 samples of cockle shells using real-time Polymerase Chain Reaction (real-time PCR) and biochemical methods. The target gene for amplification in real-time PCR was an hlyA gene because this gene was a determinant of virulence genes that produce listeriolysin O. Primers used in this study were forward primer DG69 (GTG CCG GGT AAA AGA CCA TA) and reverse primer DG74 (CGC CAC TGA GAT ACT AT) and fluorescence signals indicator using SYBR Green I. The results of analysis using real-time PCR were negative Listeria monocytogenes in all samples, while using biochemical methods there was one of 30 samples contaminated by Listeria welshimeri.

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Identification of Listeria monocytogenes on Green Mussels and Cockle Shell

Jurnal Pengolahan Hasil Perikanan Indonesia ◽

10.17844/jphpi.v19i3.15110 ◽

2017 ◽

Vol 19 (3) ◽

pp. 329

Author(s):

Winiati Puji Rahayu ◽

Ristia Rinanti ◽

Siti Nurjanah ◽

Caecillia Chrismie Nurwitri

Keyword(s):

Listeria Monocytogenes ◽

Real Time ◽

Real Time Pcr ◽

Perna Viridis ◽

Listeriolysin O ◽

Biochemical Methods ◽

Reverse Primer ◽

Many Sources ◽

Hlya Gene ◽

Cockle Shell

Abstract Green mussel (Perna viridis) and cockle shell (Anadara granosa) are one of many sources of animal protein which is many cultivated in Indonesia because their price is relatively affordable. This study was conducted to identify the presence of Listeria monocytogenes in 27 samples of green mussels and 3 samples of cockle shells using real-time Polymerase Chain Reaction (real-time PCR) and biochemical methods. The target gene for amplification in real-time PCR was an hlyA gene because this gene was a determinant of virulence genes that produce listeriolysin O. Primers used in this study were forward primer DG69 (GTG CCG GGT AAA AGA CCA TA) and reverse primer DG74 (CGC CAC TGA GAT ACT AT) and fluorescence signals indicator using SYBR Green I. The results of analysis using real-time PCR were negative Listeria monocytogenes in all samples, while using biochemical methods there was one of 30 samples contaminated by Listeria welshimeri.

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