Differential distribution patterns of ammonia-oxidizing archaea and bacteria in acidic soils of Nanling National Nature Reserve forests in subtropical China.

In addition to ammonia-oxidizing bacteria (AOB) the more recently discovered ammonia-oxidizing archaea (AOA) can also oxidize ammonia, but little is known about AOA community structure and abundance in subtropical forest soils. In this study, both AOA and AOB were investigated with molecular techniques in eight types of forests at surface soils (0-2 cm) and deep layers (18-20 cm) in Nanling National Nature Reserve in subtropical China. The results showed that the forest soils, all acidic (pH 4.

SP0454, a putative threonine dehydratase, is required for pneumococcal virulence in mice.

Increasing pressure in antibiotic resistance and the requirement for the design of new vaccines are the objectives of clarifying the putative virulence factors in pneumococcal infection. In this study, the putative threonine dehydratase sp0454 was inactivated by erythromycin-resistance cassette replacement in Streptococcus pneumoniae CMCC 31203 strain. The sp0454 mutant was tested for cell growth, adherence, colonization, and virulence in a murine model.

[Expression and distribution of Fas and Fas-L in the nasal polyps].

Objectives: To confirm the expression and distribution of Fas and Fas-L in the nasal polyps and to illustrate the role of the Fas/Fas-L system in the pathogenesis of human nasal polyps.

Methods: Investigating the transcripts of the Fas/Fas-L gene in 30 human nasal polyp tissues and 30 nasal turbinate mucosa specimens using reverse transcription-polymerase chain reaction. Localization of Fas/Fas-L was performed with immunohistochemistry.