Pseudomonas are normally found in soil. However they are able to
grow in unexpected places. They have been found in areas where a
lot of pharmaceuticals are prepared. Any carbon source, such as
soap residue or cap liner adhesives is a suitable place for them to
thrive. Other unlikely places where they have been found include
antiseptics such as ammonium compounds and bottled mineral water.
Most Pseudomonas spp. are naturally resistant to penicillin and
related beta-lactam antibiotics, but will succumb to piperacillin,
imipenem, tobramycin, or ciprofloxacin, among others. This
ability to thrive in harsh conditions is a result of their hearty
cell wall that contains porins.