Aims:  To examine the influence of pH of triple sugar iron (TSI) agar medium on the detection of hydrogen sulfide (H2S) production in Campylobacter hyointestinalis ssp. hyointestinalis (CHH). Methods and Results:  TSI medium was adjusted by the addition in HCl or NaOH to cover a pH 6·0–9·0. One loopful of bacterial growth of CHH strain ATCC 35217 was inoculated into each different pH medium, and incubated at 37°C under micro‐aerobic conditions. The H2S production was not detectable even after incubation for 72 h in acidic medium pH; however, TSI with alkaline pH (8·0–9·0) allowed detection as early as 3 h of incubation. A total of 20 CHH strains from various animal sources were examined for the detection of H2S production in TSI medium with pH 9·0. The H2S was detected in all the strains examined within 12 h, and the judgment was unambiguous. Conclusion:  The results showed that the detection of H2S production by CHH was influenced by medium pH, and TSI with alkaline condition is highly sensitive. Significance and Impact of the Study:  The findings of the present study suggest that TSI medium with alkaline pH contributes to fast detection and led to unambiguous judgment of H2S production by CHH.

Objective Campylobacter upsaliensis has been recognized as an emerging pathogen. However, little is known about its survival in the environment. To evaluate its survival capability, we estimated the reduction in viable counts of C. upsaliensis after aerobic exposure to starvation in phosphate-buffered saline (PBS), acidity (pH = 4.3), high osmolarity (4% NaCl), and dryness in wet pulp disks at different temperatures. Also, survival in dog feces and dog food at variable temperate was assessed. Results Campylobacter upsaliensis remained culturable under starvation for 4 days at 25 °C and for 10 weeks at 4 °C. C. upsaliensis was also recoverable after exposure to high osmolality for 9 days, dryness for 5 days, and acidity for 2 days, respectively. Similarly, C. upsaliensis survived in dog feces and dog food for several days at 25 °C and weeks at 4 °C. The survival capability of the organism was dependent on the water content, and also temperature. Notably, the tested C. upsaliensis strain was less resilient under all tested conditions than a C. jejuni strain used as a control. The findings showed that C. upsaliensis is able to survive under various environmental stresses, suggesting that it could pose a potential threat to public health.