Background: This study aimed to clarify factors associated with antimicrobial use in the patients with enteritis due to Campylobacter jejuni.

Methods: This retrospective cohort study was conducted at the Jikei University School of Medicine, Tokyo, Japan. This study included adult patients from whom C. jejuni was isolated in stool cultures between April 1, 2019 to March 31, 2023.

Results: Among 129 patients included in this study, 71 (55.0％) were male, median age was 26 years (IQR; 23-35), and 26 (20.2％) had underlying diseases. The most common symptom was diarrhea (121 patients, 93.8％), followed by fever (99 patients, 76.7％). Sixty (46.5％) of 129 patients were treated with antimicrobial agents. The most common administered antimicrobial agent was quinolones (22 patients), followed by fosfomycin (18 patients) and macrolides (15 patients). There were no significant differences in age, underlying disease, or symptoms between the antimicrobial-treated and non-treated groups. Forty-eight (40.0％) and 47 (39.2％) of the 120 isolates which tested for antimicrobial susceptibility were non-sensitive to levofloxacin and fosfomycin, respectively.

Conclusion: These results suggested that appropriate use of antimicrobial agents should be encouraged in Campylobacter enteritis.

Bacterial invasion and proliferation in the endometrium of postpartum dairy cows can lead to uterine diseases, including endometritis. Antimicrobials are used to treat endometritis, however, public health concerns about antimicrobial resistance (AMR) have accelerated the exploration for alternative treatment strategies. In this study, we isolated and identified bacteria from the vagina and endometrium of postpartum dairy cows and evaluated them as potential probiotic candidates. Initially, the antimicrobial activity of B. pseudolongum against Escherichia coli and Trueperella pyogenes, known pathogens of endometritis, was assessed using a cross-streaking method. It was found that 30 out of 33 strains were identified as exhibited significant antimicrobial activity. A rapid growth rate was observed in 7 out of 33 strains. Whole-genome analysis revealed that 30 out of 33 strains did not carry transmissible drug-resistance gene and could be systematically classified into three clusters.

Apple pectin is a prebiotic that is expected to be effective against allergic diseases. At a previous conference, we presented that apple pectin affects the diversity of gut microbiome, improves the immune balance of atopic dermatitis (AD), and is effective for AD. In this study, we investigated histological analysis in AD skin and changes in the composition of gut microbiome.

To induce AD, a picryl chloride solution was applied to shaved back skin of male NC/Nga mice. Treatment groups of AD mice then received an oral apple pectin solution (0.4％ or 4％) for 35 days.

Histological evaluation showed that apple pectin treatment (0.4％, 4％) attenuated epidermal thickening and decreased the number of mast cells and CD4⁺ cells in AD-induced mice (epidermal thickening: p = 0.12, p < 0.05, mast cells: p < 0.05, p = 0.11, CD4⁺ cells: p < 0.01, p < 0.05). Apple pectin treatment reduced serum IgE concentration (p < 0.05, p = 0.09). In the gut microbiome of the apple pectin-treated groups, β-diversity analysis showed that a cluster distinct from the other groups, and Anaerostipes, Roseburia, and RF39, which are related to Treg expression, were detected.

Our finding suggest that ingestion of apple pectin increased gut microbiome related to Treg expression, normalized the immune response, and improved AD histologically.