Phenotypic and Genotypic Characterization of Atypical Listeria monocytogenes and Listeria innocua Isolated from Swine Slaughterhouses and Meat Markets

Author(s)

Moreno, Luisa Zanolli ; Paixao, Renata ; Sena de Gobbi, Debora Dirani ; Raimundo, Daniele Cristine ; Porfida Ferreira, Thais Sebastiana ; Moreno, Andrea Micke ; Hofer, Ernesto ; Falavina dos Reis, Cristhiane Moura ; Matte, Glavur Rogerio ; Matte, Maria Helena

• Document type: Journal article
• Source: BIOMED RESEARCH INTERNATIONAL; v. 2014, p. 12-pg., 2014-01-01.

Abstract

In the last decade, atypical Listeria monocytogenes and L. innocua strains have been detected in food and the environment. Because of mutations in the major virulence genes, these strains have different virulence intensities in eukaryotic cells. In this study, we performed phenotypic and genotypic characterization of atypical L. monocytogenes and L. innocua isolates obtained from swine slaughterhouses and meat markets. Forty strains were studied, including isolates of L. monocytogenes and L. innocua with low-hemolytic activity. The isolates were characterized using conventional phenotypic Listeria identification tests and by the detection and analysis of L. monocytogenes-specific genes. Analysis of 16S rRNA was used for the molecular identification of the Listeria species. The L. monocytogenes isolates were positive for all of the virulence genes studied. The atypical L. innocua strains were positive for hly, plcA, and inlC. Mutations in the InlC, InlB, InlA, PI-PLC, PC-PLC, and PrfA proteins were detected in the atypical isolates. Further in vitro and transcriptomic studies are being developed to confirm the role of these mutations in Listeria virulence. (AU)

• FAPESP's process: 10/13511-5 - Research of virulence genes in strains of Listeria monocytogenes and Listeria innocua originated from environment and food
• Grantee: Luisa Zanolli Moreno
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 10/19005-4 - Identification of virulence genes and characterization of antimicrobial resistance on strains of Listeria spp. isolated from environment, food and human infection
• Grantee: Maria Helena Matte
• Support Opportunities: Regular Research Grants