1. By bacteria
   "spreads bacterially"

See also: bacterial

• Pyridium
• pyridoxal
• pyridoxamine
• pyridoxine
• pyriform
• pyriform area
• pyriform lobe
• pyrilamine
• pyrimidine
• pyrite
• pyrites
• pyro-
• pyrocellulose
• Pyrocephalus
• Pyrocephalus rubinus mexicanus
• pyrochemical
• pyrochemical process
• pyrochemistry
• pyroclastic
• pyroelectric
• pyroelectrical
• pyroelectricity
• pyrogallic
• pyrogallic acid
• pyrogallol