Bacterium concerned with pertussis is
Initially, symptoms are usually similar to those of the common cold with a runny nose, fever, and mild cough. This is followed by weeks of severe coughing fits and a high-pitched whoop sound may occur as the person breathes in (loud crowing inspiration). A person may cough so hard that they vomit, break ribs, or become very tired from the effort.
Hence bacterium concerned with pertussis is Bordetella.
So, the correct answer is 'Bordetella'.