Maintenance of strains of Campylobacter jejuni in laboratories after use of cryoprotectors and pre-treatment of stress

Abstract

This study evaluated the feasibility and the production of transcripts of sodB, p19, ciaB and dnaJ genes in strains of Campylobacter jejuni ATCC 33291, NCTC 11351, and 2383 IAL stored in whole UHT milk and or neopepton + 12% glycerol, submitted or not to pre-treatments at 4°C or 10°C for 30 minutes. The analyzes were performed immediately after freezing in liquid nitrogen (day 0) and after maintenance for 30, 60, and 90 days at -20ºC. The viability was evaluated by the traditional culture method and the production of transcripts by the RT-PCR technique. The quantification was only possible on the first day of analysis (day 0) and presented a mean of 3.0 x 107 CFU, and in the other periods of storage the strains presented confluent growth, not allowing their enumeration. The results indicated that whole UHT milk was more adequate for cryopreservation than the use of neopepton + 12% glycerol. The use of pre-treatments combined with the use of UHT milk as a cryoprotective medium stabilized the cells in order to transcribe the ciaB, dnaJ, sodBand p19 genes in the strains maintained under -20 ° for 30 to 60 days, indicating that they are more suitable methods for the maintenance of strains in the laboratory.

Roles of viable but non-culturable state in the survival of Campylobacter jejuni

“…Both genes were selected in the transcription analysis in the VBNC form due to the previous investigation that proved the presence of genes and transcripts in the 27 strains in the VT form, associated with the relevance of both in different functions in C. jejuni – ciaB (invasion) and p19 (iron uptake) – and the importance verified in the literature. ( Lee et al., 2019 ; Melo et al., 2019a ; Melo et al., 2019b ; Askoura et al., 2020 ; Monteiro et al., 2020 ; Bravo et al., 2021 ; Quino et al., 2022 ).…”