Virulence genes and genetic relationship of L. monocytogenes isolated from human and food sources in Brazil

Abstract

The herein presented assay provided a bacteriological and molecular characterization of 100 samples of L. monocytogenes isolated from human (43) and food (57) sources, from several regions of Brazil, and collected between 1975 and 2013. Antigenic characterization defined 49% of serotype 4b samples, followed by 28% of serotype 1/2b, 14% of serotype 1/2c, 8% of serotype 1/2a, and 1% of serotype 3b. Both type of samples from human and food origin express the same serotype distribution. Multiplex PCR analysis showed 13 strains of type 4b with the amplification profile 4b-VI (Variant I). Virulence genes hly, inlA, inlB, inlC, inlJ, actA, plcA, and prfA were detected in all samples, highlighting a deletion of 105pb on the actA gene in 23% of serotype 4b samples. Macrorestriction profile with ApaI at PFGE showed 55 pulsotypes, with the occurrence of the same pulsotype in hospitalized patients in São Paulo in 1992 and 1997, and two other highly related pulsotypes in patients hospitalized in Rio de Janeiro in 2008. Recognized pulsotypes in listeriosis cases have also been detected in food. Thus, the prevalence of a serotype and the persistence of certain pulsotypes herald future problems.

Isolation and Characterization of Clinical Listeria monocytogenes in Beijing, China, 2014–2016

“…The predominant serogroups were also 1/2a,3a and 1/2b,3b in strains isolated from ready-to-eat foods, raw foods and edible mushrooms in China (Chen et al, 2015, 2018a; Wu et al, 2015, 2016). While, the predominant serogroups of clinical L. monocytogenes strains in our study were different from those from the other countries such as United States, Australia, Brazil, Italy and Portugal (Mammina et al, 2009; Bueno et al, 2010; Centers for Disease Control and Prevention, 2014; Magalhaes et al, 2014; Almeida et al, 2017; Jennison et al, 2017). In United States, serotype 4b (57%) was the most commonly identified serotype of L monocytogenes , followed by serotype 1/2a (26%) and serotype 1/2b (13%) (Centers for Disease Control and Prevention, 2014).…”

Epidemiology of Listeria monocytogenes prevalence in foods, animals and human origin from Iran: a systematic review and meta-analysis

“…Haley et al showed the predominance of 3 serogroups (1/2a, 1/2b, and 4b) in the isolates collected during 2004 and 2010 within a U.S. dairy herd [ 82 ]. In a study on several regions of Brazil from 1975 to 2013, with the same serotype distribution, Almeida and colleagues introduced 4b, 1/2b, and 1/2c, as the main serotypes in human and food sources [ 83 ]. Serotypes l/2a, l/2b, and 4b were the most prevalent serotypes in sows and fattening pigs in France in 2008 [ 70 ].…”

Serotyping and antibiotic resistance of Listeria monocytogenes isolated from raw water buffalo milk and milk products

“…More than 96% of human listeriosis cases were attributed to the serotypes 1/2a, 1/2b, and 4b (Tappero, Schuchat, Deaver, Mascola,& Wenger,1995),while serotype 1/2a is generally isolated from food materials (Gilot, Genicot, & Andre, 1996). hlyA, inlA, inlB, prfA, plcA, plcB, mpl, and actA are the main virulence genes of L. monocytogenes (Almeida et al, 2017;Karthikeyan, Gunasekaran, & Rajendhran, 2015). Among these, the hlyA gene encoding Listeriolysin O (LLO) considered as an important gene for L. monocytogenes virulence.…”