Crassaminicella thermophila sp. nov., a moderately thermophilic bacterium isolated from a deep-sea hydrothermal vent chimney and emended description of the genus Crassaminicella.

A novel moderately thermophilic, anaerobic, heterotrophic bacterium (strain SY095T) was isolated from a hydrothermal vent chimney located on the Southwest Indian Ridge at a depth of 2730 m. Cells were Gram-stain-positive, motile, straight to slightly curved rods forming terminal endospores. SY095T was grown at 45-60 °C (optimum 50-55 °C), pH 6.0-7.5 (optimum 7.0), and in a salinity of 1-4.5 % (w/v) NaCl (optimum 2.5 %). Substrates utilized by SY095T included fructose, glucose, maltose, N-acetyl glucosamine and tryptone. Casamino acid and amino acids (glutamate, glutamine, lysine, methionine, serine and histidine) were also utilized. The main end products from glucose fermentation were acetate, H2 and CO2. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14 : 0 (60.5%) and C16 : 0 (7.6 %). The main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five unidentified phospholipids and two unidentified aminophospholipids. No respiratory quinones were detected. The chromosomal DNA G+C content was 30.8 mol%. The results of phylogenetic analysis of the 16S rRNA gene sequences indicated that SY095T was closely related to Crassaminicella profunda Ra1766HT (95.8 % 16S rRNA gene sequence identity). SY095T exhibited 78.1 % average nucleotide identity (ANI) to C. profunda Ra1766HT. The in silico DNA-DNA hybridization (DDH) value indicated that SY095T shared 22.7 % DNA relatedness with C. profunda Ra1766HT. On the basis of its phenotypic, genotypic and phylogenetic characteristics, SY095T is suggested to represent a novel species of the genus Crassaminicella, for which the name Crassaminicella thermophila sp. nov. is proposed. The type strain is SY095T (=JCM 34213=MCCC 1K04191). An emended description of the genus Crassaminicella is also proposed.

[Prevalence of LEE and HPI pathogenicity islands of Escherichia coli isolates from weaned piglets in China].

To investigate the distribution of LEE pathogenicity island and HPI of Yersinia entercolitica in Escherichia coli isolates from weaned piglets, PCR based on intimin gene (eaeA) of LEE pathogenicity island and high molecular weight protein 2 (HMWP1) gene (irp2) of HPI was developed. A total of 240 isolates from 140 diarrheic, 76 edematous and 24 edematous/diarrheic weaned piglets from different farms were tested for the presence of the two genes. Sequence analysis of randomly selected PCR products showed that eaeA gene of 5 isolates was 100%, irp2 gene of 7 isolates was 98.2%, fyuA gene of 5 isolates was 98.3% and Asn-tRNA-intB of 5 isolates was 95.8% identical to the published sequences. Isolates with LEE + HPI gene were more frequently detected in diarrheic swine than in edematous swine and edematous/diarrheic swine, and isolates with LEE gene were more frequently detected in edematous/diarrheic piglets than in edematous and diarrheic piglets. Furthermore, isolates with LEE or HPI or LEE + HPI were more frequently detected in diarrheic swine. 72.5% of HPI + isolates were fyuA positive and linked to asn-tRNA.