Consequences of organ choice in describing bacterial pathogen assemblages in a rodent population.

High-throughput sequencing technologies now allow for rapid cost-effective surveys of multiple pathogens in many host species including rodents, but it is currently unclear if the organ chosen for screening influences the number and identity of bacteria detected. We used 16S rRNA amplicon sequencing to identify bacterial pathogens in the heart, liver, lungs, kidneys and spleen of 13 water voles (Arvicola terrestris) collected in Franche-Comté, France. We asked if bacterial pathogen assemblages within organs are similar and if all five organs are necessary to detect all of the bacteria present in an individual animal. We identified 24 bacteria representing 17 genera; average bacterial richness for each organ ranged from 1·5 ± 0·4 (mean ± standard error) to 2·5 ± 0·4 bacteria/organ and did not differ significantly between organs. The average bacterial richness when organ assemblages were pooled within animals was 4·7 ± 0·6 bacteria/animal; Operational Taxonomic Unit accumulation analysis indicates that all five organs are required to obtain this. Organ type influences bacterial assemblage composition in a systematic way (PERMANOVA, 999 permutations, pseudo-F 4,51 = 1·37, P = 0·001). Our results demonstrate that the number of organs sampled influences the ability to detect bacterial pathogens, which can inform sampling decisions in public health and wildlife ecology.

Septic shock secondary to an acute necrotizing community-acquired pneumonia with bacteremia due to Pseudomonas aeruginosa.

Pseudomonas aeruginosa is an uncommon cause of necrotizing acute community-acquired pneumonia (CAP). Only thirteen cases have been previously reported in the literature. In this article, we describe a case of previously healthy 80-year-old male patient, who presented in septic shock caused by necrotizing CAP. Despite inadequate empiric antimicrobial treatment, the patient survived and was able to return to his home after three weeks of hospitalization. To the best of our knowledge, this is the second case of septic shock secondary to P. aeruginosa necrotizing CAP and bacteremia, with optimal clinical outcome. We highlight the evolution of this pathology remains unpredictable, despite the factors related to the host and the bacterium.

[Diffusion of amikacin into the sinuses in patients with nosocomial sinusitis. Administration of a single dose per day]. / Diffusion de l'amikacine dans les sinus chez les malades ayant une sinusite nosocomiale. Administration en dose unique journalière.

Twenty mechanically ventilated patients with nosocomial sinusitis were treated with amikacin 15 mg/kg administered either once a day (group 1 patients) or twice a day (group 2 patients). Amikacin was assayed in serum and in the liquid drained from the sinuses 8 times over a 24 hours' period (group 1) or 7 times over a 12 hours' period (group 2). The amikacin concentration peak was 10.9 mg/l in group 1 and 5.1 mg/l in group 2. It is concluded that amikacin can be used to treat patients with nosocomial sinusitis. High amikacin concentrations are reached with the once a day dosage.