Enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain NTCC? EDL933

Product category產(chǎn)品種類: Bacteria
Classification分類: Enterobacteriaceae, Escherichia
菌株名稱Strain designation: EHEC EDL933
描述Discription: 標(biāo)準(zhǔn)菌株Type strain: No
提供形式Product format: Freeze-dried
保存溫度Storage conditions: 2°C to 8°C

操作方法Handling information
培養(yǎng)基Medium: BioVector? Medium 3: Nutrient agar or nutrient broth
培養(yǎng)溫度Temperature: 37°C
氣體環(huán)境Atmosphere:Aerobic

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain NTCC? EDL933 harbors multiple prophage-associated open reading frames (ORFs) in its genome which are highly homologous to the chromosomal nanS gene. The latter is part of the nanCMS operon, which is present in most E. coli strains and encodes an esterase which is responsible for the monodeacetylation of 5-N-acetyl-9-O-acetyl neuraminic acid (Neu5,9Ac2). Whereas one prophage-borne ORF (z1466) has been characterized in previous studies, the functions of the other nanS-homologous ORFs are unknown. In the current study, the nanS-homologous ORFs of EDL933 were initially studied in silico. Due to their homology to the chromosomal nanS gene and their location in prophage genomes, we designated them nanS-p and numbered the different nanS-p alleles consecutively from 1 to 10. The two alleles nanS-p2 and nanS-p4 were selected for production of recombinant proteins, their enzymatic activities were investigated, and differences in their temperature optima were found. Furthermore, a function of these enzymes in substrate utilization could be demonstrated using an E. coli C600ΔnanS mutant in a growth medium with Neu5,9Ac2 as the carbon source and supplementation with the different recombinant NanS-p proteins. Moreover, generation of sequential deletions of all nanS-p alleles in strain EDL933 and subsequent growth experiments demonstrated a gene dose effect on the utilization of Neu5,9Ac2. Since Neu5,9Ac2 is an important component of human and animal gut mucus and since the nutrient availability in the large intestine is limited, we hypothesize that the presence of multiple Neu5,9Ac2 esterases provides them a nutrient supply under certain conditions in the large intestine, even if particular prophages are lost.

操作流程Handling procedure
Open vial according to enclosed instructions.
Using a single tube of #3 broth (5 to 6 mL), withdraw approximately 0.5 to 1.0 mL with a Pasteur or 1.0 mL pipette.  Rehydrate the entire pellet.
Aseptically transfer this aliquot back into the broth tube.  Mix well.
Use several drops of the suspension to inoculate a #3 agar slant and/or plate
Incubate the tubes and plate at 37°C for 24 hours.