Gram negative bacteria have also been identified in water-damaged buildings. These bacteria produce endotoxins (also known as lipopolysaccharide or LPS) and are potentially infectious--particularly species of E. coli, Enterobacter and Pseudomonas aeuroginosa, etc.
Other gram negative bacteria are species of Agrobacterium, Caulobacter, Stenophomonas and Chryseomonas (Andersson et aI, 1997).
Gram negative bacteria are ubiquitous in the environment and have been isolated from contaminated ventilation systems, humidifiers, carpeting, drywall, etc. in large numbers in water-damaged buildings.
Pet fecal matter from dogs and cats and sewage are two sources of gram negative bacteria. They release endotoxins that can cause a variety of symptoms as well as pulmonary inflammation in building occupants (Rylander 2004; Yang 2004; Simpson et al, 2006; Martinez 2007a, b).
Finally, bioaerosols of Staphylococcus aureus, multi-antibiotic-resistant and non-resistant strains, have been isolated from healthy residential homes (Gandara et al, 2006).