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.