Molecular typing and virulence markers of Yersinia enterocolitica strains from human, animal and food origins isolated between 1968 and 2000 in Brazil

Abstract

Molecular typing and virulence markers were used to evaluate the genetic profiles and virulence potential of 106 Yersinia enterocolitica strains. Of these strains, 71 were bio-serotype 4/O : 3, isolated from human and animal clinical material, and 35 were of biotype 1A or 2 and of diverse serotypes, isolated from food in Brazil between 1968 and 2000. Drug resistance was also investigated. All the strains were resistant to three or more drugs. The isolates showed a virulence-related phenotype in the aesculin, pyrazinamidase and salicin tests, except for the food isolates, only two of which were positive for these tests. For the other phenotypic virulence determinants (autoagglutination, Ca ++ dependence and Congo red absorption), the strains showed a diverse behaviour. The inv, ail and ystA genes were detected in all human and animal strains, while all the food isolates were positive for inv, and 3 % of them positive for ail and ystA. The presence of virF was variable in the three groups of strains. The strains were better discriminated by PFGE than by enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). A higher genomic similarity was observed among the 4/O : 3 strains, isolated from human and animal isolates, than among the food strains, with the exception of two food strains possessing the virulence genes and grouped close to the 4/O : 3 strains by ERIC-PCR. Unusually, the results revealed the virulence potential of a bio-serotype 1A/O : 10 strain, suggesting that food contaminated with Y. enterocolitica biotype 1A may cause infection. This also suggests that ERIC-PCR may be used as a tool to reveal clues about the virulence potential of Y. enterocolitica strains. Furthermore, the results also support the hypothesis that animals may act as reservoirs of Y. enterocolitica for human infections in Brazil, an epidemiological aspect that has not been investigated in this country, confirming data from other parts of the world. INTRODUCTIONYersinia enterocolitica is the most prevalent Yersinia species connected to disease in humans (Bottone, 1999; RobinsBrowne, 2001). It has also frequently been isolated from animals, food and the environment (Fredriksson-Ahomaa et al., 1999;Thoerner et al., 2003; Falcão et al., 2004).Y. enterocolitica is responsible for gastroenteritis and other syndromes in humans and animals (Bottone, 1999 biochemical and serological tests that enable the differentiation of the strains into diverse bio-serotypes (Aleksic & Bockemühl, 1999). Also, pathogenic strains are related to some phenotypic characteristics, such as pyrazinamidase production, aesculin hydrolysis, salicin fermentation, calcium dependence, autoagglutination and Congo red absorption (Bottone, 1999). Molecular genetic studies have emphasized the importance of a virulence plasmid (pYV) that encodes various virulence genes, among them virF, which is an important transcriptional regulator of other plasmid genes, as well as the role of chromosomal virulence genes that mediate cell invasion (inv and ail) and produce a therm...

Safety characterization of Yersinia enterocolitica strains isolated from raw milk in Western Algeria

“…Y. enterocolitica has been isolated from raw milk and pasteurized dairy products in several countries e.g. in the USA (Jayarao and Henning, 2001), China (Wang et al, 2010;Ye et al, 2014), Mexico (Bernardino-Varo et al, 2013), Brazil (Falcão et al, 2006), Iran (Soltan-Dallah et al, 2004;Rahimi et al, 2014;Jamali et al, 2015), India (Subha et al, 2009), Turkey (Guven et al, 2010), Nigeria (Okeke and Okwori, 2014), Egypt (Darwish et al, 2015) and other countries. In Algeria, the raw milk is still frequently consumed.…”

Phosphoglucomutase ofYersinia pestisIs Required for Autoaggregation and Polymyxin B Resistance

“…A correlation between autoaggregation and virulence has been shown for many Gram-negative bacteria such as Yersinia enterocolitica (19,38,44), Escherichia coli (67), Campylobacter jejuni (32), and Vibrio cholerae (14). In one study, autoaggregation was observed in about 70% of human and animal clinical isolates of Y. enterocolitica, whereas all environmental isolates tested were negative for autoaggregation (38).…”

“…In one study, autoaggregation was observed in about 70% of human and animal clinical isolates of Y. enterocolitica, whereas all environmental isolates tested were negative for autoaggregation (38). Thus, the autoaggregation phenotype has been used as a virulence marker for enteropathogenic Yersinia (19,38). Enteropathogenic Yersiniae species, Y. enterocolitica and Y. pseudotuberculosis, autoaggregate via a YadA-mediated hydrophobic interaction in tissue culture medium at 37°C (60).…”

Molecular typing of Yersinia pseudotuberculosis strains isolated from livestock in Brazil

“…Genomic DNA was extracted from the growing cells as described by Falcão et al (2006). The DNA concentration of each sample was determined using a NanoDrop 1000 (Thermo Scientific, San Jose, CA, USA), and the purity of the DNA was estimated as described by Sambrook and Russell (2001).…”