Clostridium difficile
Swabs can introduce oxygen to anaerobic specimens, which can affect the growth of anaerobic bacteria. This may result in false-negative culture results. It is recommended to use proper anaerobic collection and transport systems to maintain anaerobic conditions.
Tissue samples should be placed into a degassed bag and sealed, or into a gassed out screw top vial that may contain oxygen-free prereduced culture medium and tightly capped. The specimens should be plated as rapidly as possible onto culture media
Bacteria that do not require aerobic respiration are known as anaerobic bacteria. These bacteria can survive and grow in the absence of oxygen by using alternative electron acceptors in anaerobic pathways such as fermentation or anaerobic respiration. Examples of anaerobic bacteria include Clostridium and Methanogens.
Anaerobic bacteria or facultative anaerobic bacteria.
anaerobic
aerobic bacteria use oxygen based respiration, anaerobic bacteria use either nonoxygen based respiration (e.g. nitrogen, sulfur) or fermentation.
anaerobic.
used for growth anaerobic bacteria
Salmonella bacteria are anaerobic.
Aerobic bacteria uses oxygen for cellular respiration and anaerobic bacteria doesn't require oxygen to survive. ˇ_ˇ 
Anaerobic means without oxygen. Those are anaerobic bacteria.
Firstly, pathogenic is not the opposite of anaerobic. The vast majority of bacteria are non-pathogenic, but this doesn't mean they are anaerobic.