Evidence of Antimicrobial Resistance and Presence of Pathogenicity Genes in Yersinia enterocolitica Isolate from Wild Boars

Abstract

Yersinia enterocolitica (Ye) is a very important zoonosis andwild boars play a pivotal role in its transmission. In the last decade, the wild boar population has undergone a strong increase that haspushed them towards urbanized areas, facilitating the human-wildlife interface and the spread of infectious diseases from wildlife to domestic animals and humans. Therefore, it is important to know the serotype, antimicrobial resistance and presence of pathogenicity genes of Yersinia enterocolitica (Ye) isolated in species. From 2013 to 2018, we analyzed the liver of 4890 wild boars hunted in Liguria region; we isolated and serotyped 126 Ye positive samples. A decisive role in the pathogenicity is given by the presence of virulence genes; in Ye isolated we found ystB (~70%), ymoA (45.2%), ail (43.6%) and ystA (~20%). Moreover, we evaluated the susceptibility at various antimicrobic agents (Ampicillin, Chloramphenicol, Enrofloxacin, Gentamicin, Kanamycin, Trimethoprim-Sulfamethoxazole, Sulfisoxazole, Ceftiofur and Tetracycline). The antibiotic resistance was analyzed, and we found a time-dependent increase. It is important to shed light on the role of the wild boars as a reserve of potentially dangerous diseases for humans, and also on the antibiotic resistance that represents a public health problem.

Keywords: Yersinia enterocolitica; antibiotic-resistance; biotypes; pathogenicity; wild boar.

Figure 1

Percentage of Yersinia enterocolitica (Ye) serotypes distribution. In biotypes 1A and 1B, the most frequent serotype was O:8, followed by O:5. The biotype 2 was represented by a single not-typable sample. However, in all biotypes (1A, 1B and 2) an elevated percentage of serotypes was found not-typable (31.69%, 50% and 100%, respectively).