Detection of virulence genes and antimicrobial susceptibility profile of Listeria monocytogenes isolates recovered from artisanal cheese produced in the Southern region of Brazil

Abstract

Listeria monocytogenes is an opportunistic pathogen that causes listeriosis, a foodborne disease with low incidence but with high mortality rate in humans. This microorganism has been recovered from several dairy products, especially those produced with raw milk. The objective of this work was to investigate the presence of virulence genes, and also to defi ne the antimicrobial susceptibility profi le of L. monocytogenes isolates recovered from serrano artisanal cheese produced in Southern region of Brazil.Nine strains of L. monocytogenes (serotypes 1/2b and 4b) were evaluated through PCR to detect the presence of the virulence genes hly, inlA, inlC, inlJ, actA, plcB and iap, while antimicrobial susceptibility profi le was determined via disk diffusion method. All strains exhibited the presence of the genes hly and plcB, whereas the other genes (iap, actA, inlA, inlC and inlJ) were only detected in eight strains. We verifi ed that all strains were resistant to at least one antimicrobial agent and three of them showed multidrug resistance. These fi ndings demonstrated the serrano artisanal cheese offers risks to consumers' health and point to a need of adaptations and monitoring of manufacturing process of this food, in order to prevent the dissemination of L. monocytogenes.

Occurrence and Multidrug Resistance in Strains of Listeria monocytogenes Recovered from the Anaerobic Co-Digestion Sludge Contained in a Single Stage Steel Biodigester: Implications for Antimicrobial Stewardship

“…This can be explained by the fact that the practice increases selective pressure, favouring the development of antibiotic resistance occurring via mutations or the acquisition of mobile genetic elements. Consequently, the findings of our current study are in line with several others [ 7 , 10 ] relating to antibiotic resistance in Listeria species found in environmental samples, and are not surprising. It is apparent that the use of antibiotics at sub-therapeutic levels in the mass production of poultry, eggs, and pork has promoted the development and maintenance of MAR organisms occurring in the faecal environment of these animals [ 41 ].…”

“…monocytogenes isolates were multidrug resistant, demonstrating resistance to three or more antibiotics in the present study. Other authors have noted the varying prevalence of multidrug resistant Listeria species or monocytogenes across the globe, with 2.5% in Russia [ 10 ], 33.33% in Brazil [ 7 ], 54% in Spain [ 15 ], 73.91% in Turkey [ 14 ], and 100% in Bangladesh [ 64 ] and Malaysia [ 19 ]. These data indicate geographical differences, which could be associated with regional use of antimicrobials.…”

“…monocytogenes during storage of manure, transforming into a viable but non culturable state. Thus, humans might become contaminated with the bacterium upon consumption of dairy products, meat products and via handling or practices that occur within farms, hence leading to listeriosis infection [ 7 ].…”