The Fitness Cost of Antibiotic Resistance in Streptococcus pneumoniae: Insight from the Field

Laboratory studies have suggested that antibiotic resistance may result in decreased fitness in the bacteria that harbor it. Observational studies have supported this, but due to ethical and practical considerations, it is rare to have experimental control over antibiotic prescription rates.We analyze data from a 54-month longitudinal trial that monitored pneumococcal drug resistance during and after biannual mass distribution of azithromycin for the elimination of the blinding eye disease, trachoma. Prescription of azithromycin and antibiotics that can create cross-resistance to it is rare in this part of the world. As a result, we were able to follow trends in resistance with minimal influence from unmeasured antibiotic use. Using these data, we fit a probabilistic disease transmission model that included two resistant strains, corresponding to the two dominant modes of resistance to macrolide antibiotics. We estimated the relative fitness of these two strains to be 0.86 (95% CI 0.80 to 0.90), and 0.88 (95% CI 0.82 to 0.93), relative to antibiotic-sensitive strains. We then used these estimates to predict that, within 5 years of the last antibiotic treatment, there would be a 95% chance of elimination of macrolide resistance by intra-species competition alone.Although it is quite possible that the fitness cost of macrolide resistance is sufficient to ensure its eventual elimination in the absence of antibiotic selection, this process takes time, and prevention is likely the best policy in the fight against resistance

Robotic-assisted gastrectomy for gastric cancer: single Western center results

A robotic approach to abdominal surgery procedures may improve postoperative outcomes compared to either open or laparoscopic approaches. The role of robotics for gastric surgery, however, is still being evaluated. A retrospective review of the prospectively maintained database for robotic gastric surgery at University of Siena between 2011 and 2020 was conducted. Data regarding surgical procedures, early postoperative outcomes, and long-term follow-up were analyzed. 38 patients underwent robotic partial or total gastrectomy. Conversion to open occurred in two patients (5.2%) due to locally advanced disease as well as difficult identification of primary lesion. Postoperative morbidity was 13.1% while no postoperative mortality was registered. The mean length of operation was 358.6 (220–650) minutes and the mean number of retrieved lymph nodes was 35.8 (range: 5–73). The median OS of all population was 70.9 months. The median 5-year OS for the patients with positive nodes was worse than that of patients without metastatic lymph nodes [51.4 months (95% CI 35.5–67.4) vs. 79.5 months (95% CI 67.1–91.8); p = 0.079]. The interesting results including postoperative morbidity as well as mortality rate, the surgical outcomes, and the 5-year OS, were to be acceptable considering the data recorded by previous studies on robotic gastrectomy. This study demonstrated that robotic gastrectomy is feasible and can be safely performed. However, further follow-up and randomized clinical trials are required to confirm the role of a robotic approach in gastric cancer surgery