Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Foggia, Italy.
PLoS One. 2022 Jul 13;17(7):e0268706. doi: 10.1371/journal.pone.0268706. eCollection 2022.
Yersiniosis is the third most reported food-borne zoonosis in Europe. The aim of the present study was to perform the search for Yersinia enterocolitica in food samples collected from Apulia and Basilicata regions (Southern Italy) and to characterize any isolates by classical and modern analytical methods. A total of 130 samples were analyzed between July 2018 and July 2019: most of them were raw milk and dairy products made from it. Furthermore, 8 out of 130 samples were individual milk samples collected from bovines reared in a Brucella-free farm which showed false positive serological reaction for brucellosis due to the presence of pathogenic Y. enterocolitica O:9 biotype 2 in faeces. The Real Time PCR targeting the ail gene and the culture method were performed to detect pathogenic Y. enterocolitica. Isolates were subjected to API 20E (Biomerieux) and MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization Time-of-Flight) for species identification. All samples were negative for the ail gene. The culture method allowed to isolate suspicious colonies from 28 samples. The API 20E system and the MALDI-TOF MS technique identified 20 Y. enterocolitica and 1 Y. intermedia in a concordant way. The remaining 7 strains were all identified as Y. enterocolitica by the API 20E system, while the MALDI-TOF MS recognized 4 Y. intermedia, 1 Y. bercovieri and 2 Y. massiliensis. Genotypic characterization of the discordant strains was performed by rMLST and it confirmed the MALDI-TOF MS' results. Only non-pathogenic Y. enterocolitica biotype 1A strains were found, although with a non-negligible prevalence (P = 0.15 with CI 95% = ± 0.06). This study indicates a poor circulation of pathogenic Y. enterocolitica in food products made and marketed in the investigated areas. However, the small number of samples, insufficient for some food categories such as meat and vegetable, does not allow to exclude the presence of pathogenic strains at all.
耶尔森菌病是欧洲报告第三多的食源性病原体。本研究的目的是在意大利南部普利亚大区和巴西利卡塔大区收集的食品样本中寻找肠结肠炎耶尔森菌，并通过经典和现代分析方法对任何分离株进行特征描述。2018 年 7 月至 2019 年 7 月期间共分析了 130 个样本，其中大部分为原料奶和以其为原料制成的乳制品。此外，在 130 个样本中有 8 个是从无布鲁氏菌的农场中饲养的奶牛中采集的个体牛奶样本，由于粪便中存在致病性肠结肠炎耶尔森菌 O:9 生物型 2，这些样本的布鲁氏菌血清学反应呈假阳性。使用针对 ail 基因的实时 PCR 和培养方法检测致病性肠结肠炎耶尔森菌。对分离株进行 API 20E（生物梅里埃）和 MALDI-TOF MS（基质辅助激光解吸电离飞行时间）鉴定。所有样本均未检测到 ail 基因。培养方法从 28 个样本中分离出可疑菌落。API 20E 系统和 MALDI-TOF MS 技术以一致的方式鉴定出 20 株肠结肠炎耶尔森菌和 1 株中间耶尔森菌。剩余的 7 株菌均被 API 20E 系统鉴定为肠结肠炎耶尔森菌，而 MALDI-TOF MS 则鉴定出 4 株中间耶尔森菌、1 株伯氏耶尔森菌和 2 株马西利亚耶尔森菌。通过 rMLST 对不相符菌株进行基因分型鉴定，结果证实了 MALDI-TOF MS 的结果。仅发现非致病性肠结肠炎耶尔森菌生物型 1A 株，尽管其流行率不容忽视（P = 0.15，95%置信区间为±0.06）。本研究表明，在调查地区生产和销售的食品中，致病性肠结肠炎耶尔森菌的传播情况较差。然而，由于某些食品类别（如肉类和蔬菜）的样本数量较少，不足以排除所有致病性菌株的存在。
