sp. nov., a marine bacterium isolated from surface seawater of the Yellow Sea, and proposal of gen. nov., comb. nov. and comb. nov.

A bacterial strain designated RZ02 was isolated from surface seawater collected from the Yellow Sea in PR China and characterized by polyphasic taxonomy. Cells of strain RZ02 were Gram-stain-negative, aerobic, non-motile, catalase- and oxidase-positive rods forming ochre-pigmented colonies. Growth occurred at 7-36 °C (optimum, 30 °C), at pH 6.

[Experimental study on cross-resistance of Culex pipiens pallens to 3 kinds of chemical pesticides].

Objective: To understand the cross-resistance of Culex pipiens pallens to common pesticides, so as to provide the evidence for improving the application of chemical pesticides.

Methods: The IV instar larvae of DDVP-resistant, propoxur-resistant and cypermethrin-resistant strains as well as the sensitive strain of Culex pipiens pallens were collected to detect the resistance to DDVP, propoxur and cypermethrin based on the WHO bioassay method.

Results: The resistance coefficients of DDVP-resistant strain to DDVP, propoxur and cypermethrin were 14.

[Drug resistance evolution of dichlorvos-resistant and cypermethrin-resistant strains of Culex pipiens pallens].

Susceptible strain of Culex pipiens pallens was selected with dichlorvos and cypermethrin for 42 generations in the laboratory. At generation 42, the resistance level to dichlorvos and cypermethrin was 12.2-fold and 534.

[Differences of acetylcholinesterase level in variety classes and strains of Culex pipiens pallens].

Objective: To investigate the diversity of acetylcholinesterase (AChE) activity in variety classes and strains of Culex pipiens pallens and provide a basis for the insecticide-resistance detection of mosquito by biochemical method.

Methods: AChE insensitivity of single mosquito was determined, using acetythiocholine iodide (ATch) as the substrate, 5,5'-dithio-bis (2-nitrobenzoic acid) (DTNB) as the developer, and propoxur as the inhibitor.

Result: There were significant differences in AChE activity among the four types of IV instar larvae and 3-day-old adult female of sensitive strain mosquito (P<0.