Causes of Periodontal Pockets?

What specific bacteria cause this kind of problem, when there is no bleeding and noticeable inflammation (only a periodontal pocket)?
There are too many and I can't figure out myself.
Maybe it's Streptococcus sanguinis and Streptococcus gordonii?
Or...
From: http://www.umm.edu/patiented/articles/what_causes_periodontal_disease_000024_...


Following are some of the bacteria most implicated in periodontal disease and bone loss:

Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. These two bacteria appear to be particularly likely to cause aggressive periodontal disease. Both P. gingivalis and A. actinomycetemcomitans, along with multiple deep pockets in the gum, are associated with resistance to standard treatments for gum disease. P. gingivalis may double the risk for serious gum disease. P. gingivalis produces enzymes, such as one called arginine-specific cysteine proteinase, that may disrupt the immune system and lead to subsequent periodontal connective tissue destruction.
Bacteroides forsythus is also strongly linked to periodontal disease.
Other bacteria associated with periodontal disease are Treponema denticola, T. socranskii, and P. intermedia. These bacteria, together with P. gingivalis, are frequently present at the same sites, and are associated with deep periodontal pockets.