is emphyzema caused by bacteria?

No.  Emphysema is a destructive syndrome of the lung tissue that is one of two primary disorders (along with chronic bronchitis) that are known as Chronic Obstructive Pulmonary Disease (COPD).  The number one cause of emphysema is cigarette smoking, but it can be caused by other things - however, not by bacteria.  Persons with COPD are susceptible to infections with bacteria and viruses and often develop significant breathing problems with these pneumonias (infection of the lung).  Acute exacerbations of chronic bronchitis are caused by infections, but those infections can be caused by either bacteria or viruses - the latter most often by cold viruses or influenza.  Thus the guidance to get an influenza vaccine - it's not too late to do this.

Daniel A.