Volume 21, Issue 3, Pages 219-229 (September 2014) Development of microbiological field methodology for water and food-chain hygiene analysis of Campylobacter spp. and Yersinia spp. in Burkina Faso, West Africa  Elias Hakalehto, Outi Nyholm, Isidore J.O. Bonkoungou, Assèta Kagambega, Kari Rissanen, Anneli Heitto, Nicolas Barro, Kaisa Haukka  Pathophysiology  Volume 21, Issue 3, Pages 219-229 (September 2014) DOI: 10.1016/j.pathophys.2014.07.004 Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 1 (a and b) Specifically designed enrichment syringes are used in the PMEU Spectrion® (Samplion Oy, Siilinjärvi, Finland). The incoming and outgoing gases are sterile filtered. Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 2 (a) 30 pieces of 3.5l CampyGen gas sachets (for 3.5l of gas mixture) were added into the sack (110l). The sack was closed air-tightly with tape. (b) Air was pumped into the sack through the valve. (c) The sack was connected to the PMEU and gas flow adjusted. (d) In the sack there was enough gas–air mixture for 24h of microaerobic cultivation in ten enrichment syringes of the PMEU Spectrion®. Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 3 Changes in the relative density in PMEU syringes 3 (a) and 4 (b). Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 4 Changes in the relative density in PMEU syringes 7 (a) and 8 (b). Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 5 Changes in the relative density in PMEU syringe 9. Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 6 Yersinia enterocolitica grew about 10 times higher numbers in selective conditions in the PMEU Spectrion® at +25°C than E. coli and Klebsiella sp. in these same conditions. The onset of growth was recorded in equal time (18h) with the pure culture (compare Fig. 7). It can, therefore, be deduced that the PMEU method allowed the undisturbed selective growth of the Yersinia strain among enterobacterial intestinal strains. Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions

Fig. 7 Pure Yersinia enterocolitica laboratory strain cultivated from an inocula of about 400cfu/ml in the PMEU Spectrion® at +25°C. The onset of growth was recorded after 18h of cultivation. Pathophysiology 2014 21, 219-229DOI: (10.1016/j.pathophys.2014.07.004) Copyright © 2014 Elsevier Ireland Ltd Terms and Conditions