Department of Microbiology, Faculty of Natural and Agricultural Sciences, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, South Africa.
Alberta Agriculture and Forestry, Lethbridge, Alberta, Canada.
Can J Microbiol. 2020 Apr;66(4):328-336. doi: 10.1139/cjm-2019-0554. Epub 2020 Feb 4.
This study examined the biofilm-forming ability of six non-O157 Shiga-toxin-producing (STEC) strains: O116:H21, wzx-Onovel5:H19, O129:H21, O129:H23, O26:H11, and O154:H10 on stainless steel coupons after 24, 48, and 72 h of incubation at 22 °C and after 168 h at 10 °C. The results of crystal violet staining revealed that strains O129:H23 and O154:H10 were able to form biofilms on both the submerged surface and the air-liquid interface of coupons, whereas strains O116:H21, wzx-Onovel5:H19, O129:H21, and O26:H11 formed biofilm only at the air-liquid interface. Viable cell counts and scanning electron microscopy showed that biofilm formation increased ( < 0.05) over time. The biofilm-forming ability of non-O157 STEC was strongest ( < 0.05) at 22 °C after 48 h of incubation. The strongest biofilm former regardless of temperature was O129:H23. Generally, at 10 °C, weak to no biofilm was observed for isolates O154:H10, O116:H21, wzx-Onovel5:H19, O26:H11, and O129:H21 after 168 h. This study found that temperature affected the biofilm-forming ability of non-O157 STEC strains. Overall, our data indicate a high potential for biofilm formation by the isolates at 22 °C, suggesting that non-O157 STEC strains could colonize stainless steel within food-processing facilities. This could serve as a potential source of adulteration and promote the dissemination of these potential pathogens in food.
本研究检测了 6 株非 O157 型志贺毒素产生型大肠埃希氏菌(STEC):O116:H21、wzx-Onovel5:H19、O129:H21、O129:H23、O26:H11 和 O154:H10 在 22°C 孵育 24、48 和 72 小时以及在 10°C 孵育 168 小时后在不锈钢试片上形成生物膜的能力。结晶紫染色的结果表明,O129:H23 和 O154:H10 株可在试片的浸没表面和气液界面形成生物膜,而 O116:H21、wzx-Onovel5:H19、O129:H21 和 O26:H11 株仅在气液界面形成生物膜。活细胞计数和扫描电子显微镜显示,生物膜形成随时间增加(<0.05)。非 O157 STEC 的生物膜形成能力在 22°C 孵育 48 小时后最强(<0.05)。无论温度如何,最强的生物膜形成者都是 O129:H23。一般来说,在 10°C 下,168 小时后,O154:H10、O116:H21、wzx-Onovel5:H19、O26:H11 和 O129:H21 分离株几乎没有或没有形成生物膜。本研究发现,温度影响非 O157 STEC 菌株的生物膜形成能力。总体而言,我们的数据表明这些分离株在 22°C 下具有很强的生物膜形成能力,这表明非 O157 STEC 菌株可能在食品加工设施中定植于不锈钢表面。这可能成为掺假的潜在来源,并促进这些潜在病原体在食品中的传播。