Helicobacter cholecystus bacteremia in an adult with acute cholecystitis.

We report the isolation of Helicobacter cholecystus from a positive blood culture from a 58-year-old man in China who had bacteremia and acute cholecystitis. The patient's condition improved after symptomatic support treatment and subtotal cholecystectomy. This finding suggests that H. cholecystus should be considered as potential human pathogens.

Preliminary comparative genomics analysis among Corynebacterium kroppenstedtii complex necessitates a reassessment of precise species associated with mastitis.

AIMS: This study aimed to characterize the first complete genome of Corynebacterium parakroppenstedtii and clarify the evolutionary relationship in the Corynebacterium kroppenstedtii complex (CKC) by using comparative genomics analysis. METHODS AND RESULTS: The genome of isolate yu01 from a breast specimen was sequenced, and 35 CKC genomes were collected. Analysis of 16S rRNA, rpoB, and fusA suggested ambiguous identification, whereas ANI analysis assigned isolate yu01 as Coryne. parakroppenstedtii. The fourth genospecies "Corynebacterium aliikroppenstedtii" was identified in CKC. Comparative genomics analysis suggested that the genomic arrangement in CKC was highly conserved. A total of 43 potential virulence genes and 79 species-specific genes were detected. Most genome-based phylogenetic analysis were incapable of resolving the interspecific evolutionary relationships among CKCs. A total of 20 core genes were found to be distinguishable in CKC. CONCLUSIONS: This study suggested the limited divergence and unavailability of normal single gene-based identification in CKC and questioned the precise species of strains associated with mastitis, identified as Coryne. kroppenstedtii in previous studies. The 20 genes showed potential to enhance the methods for the identification and epidemiological investigation of CKC.

Thermal loading in laser diode end-pumped Yb3+/Er3+ codoped phosphate glass laser.

We investigate, based on laser performance, the fractional thermal loadings in a Yb(3+)/Er(3+) codoped phosphate glass laser. The results indicate that fractional thermal loading increases with Er(3+) doping concentration nonlinearly. Above an Yb(3+) doping level, the increase of Yb(3+) cannot promote laser performance but induces a more serious heat effect. We investigate the main factors that simultaneously affect laser and thermal performances. The results show that the ratio of laser output power to heat is sensitive to beam overlap efficiency, the laser extraction efficiency, especially to quantum efficiency of laser material. The optimized doping concentrations of Yb(3+) and Er(3+) are deduced.