Plasmid pWW115, a cloning vector for use with Moraxella catarrhalis

Area of Science:

• Microbiology
• Molecular Biology
• Genetics

Background:

• The plasmid shuttle vector pWW102B exhibits limited replication in Moraxella catarrhalis strains.
• Genetic manipulation of M. catarrhalis has been challenging due to vector limitations.

Purpose of the Study:

• To develop a novel plasmid vector for efficient replication in diverse Moraxella catarrhalis strains.
• To demonstrate the utility of the new vector for gene cloning and functional studies in M. catarrhalis.

Main Methods:

• Construction of pWW115 as a deletion mutant of pWW102B, removing the pACYC184 origin and chloramphenicol-resistance gene.
• Testing replication efficiency of pWW115 across various M. catarrhalis strains.
• Cloning the M. catarrhalis UspA2 gene into pWW115 and assessing its function in a mutant strain.

Main Results:

• Plasmid pWW115 demonstrated replication in all tested M. catarrhalis strains, including previously refractory ones.
• The UspA2 serum-resistance factor gene was successfully cloned into pWW115.
• The recombinant plasmid conferred serum resistance to a serum-sensitive M. catarrhalis uspA2 mutant.

Conclusions:

• The novel plasmid pWW115 is a versatile tool for genetic studies in Moraxella catarrhalis.
• pWW115 facilitates the functional analysis of M. catarrhalis genes, such as UspA2.
• This advancement improves genetic manipulation capabilities for this important bacterial pathogen.