Below is information on the most common bacteria pathogens that cause gum disease. I know not all people have this type of bacteria, but it shows how different types of bacteria in the mouth require different treatment. The most common Antibiotic treatment is metronidazol, but some of the bacteria are resistant to it. Who knows what other kind of bacteria there are in mouth, and what it is sensitive or resistant to.

I did a quick internet search and mostly found intestinal bacteria culture tests or saliva tests for other things besides bacteria. So, please post websites to test bacteria in mouth on this thread.

The following 11 oral bacteria are the ones most often implicated in gum disease. They are the mostly gram negative, anaerobic varieties. These bacteria are capable of opening breaches in the body's barriers and suppressing defense mechanisms, leading to disease and the opening for other pathogens such as viruses and parasites to add their destructive potential.

1. Actinobacillus actinomycetemcomitans
• A small, gram negative, facutatively anaerobic, non motile rod, not considered part of normal flora but a true infectious agent
• One of the few bacteria in the mouth capable of colonizing the oral mucosa because of attachment mechanism of long arms or fimbriae on the surface
• Can be inhibited from growth in the presence of Streptococcus strains, once established very effective at inhibiting other species including Streptococcus
• Associated with Juvenile localized periodontitis
• Possesses many virulence factors: leucotoxin (kills human neutrophils and monocytes), immunosuppressive factor, bone resorption mediation factor, fibroblast proliferation Depression factor, causes release of lysosomal products from damaged immune cells, perturbs adaptive mechanisms, delays antibody sysnthesis, invasive
• Implicated in endocarditis, pericarditis, meningitis, osteomyelitis, pnemonia and sub-cutaneous abscess
• Sensitive to Amoxicillin, Claritromycin and Doxycycline, practically insensitive to Metronidazol
• Transmittable from parent to child

2. Porphyromonas gingivalis
• A gram negative, non motile small strictly anaerobic rod, has numerous fimbriae for attachment
• Not considered part of normal flora
• Virulence factors: posseses very strong proteolytic enzymes, collagenases, chemical adherence factors ( attaches to erythrocytes and causes agglutination), decomposes immunogloblins, invasive
• Implicated in coronary artery disease
• Transmissible from parent to child and to a lesser degree between partners
• Sensitive to Metronidazol

3. Bacteriodes forsythus
• A strictly anaerobic, gram negative, fusiform rod
• Associated with refractory periodontitis, considered a major periodontal pathogen, possesses strong proteolytic properties
• Sensitive to metronidazol and Clindamycin but resistant to Doxycycline

4. Treponema denticola
• An anaerobic, spiral shaped bacteria from the spirochete family, nearly impossible to culture, can support small quantities of oxygen
• Very strongly proteolytic, invasive in cooperation with other bacteria
• Antibiotic sensitivity in vivo is not evident

5. Prevotella intermedia
• Strict anaerobe, gram negative rod, can ferment complex sugars
• Highly proteolytic
• Sometimes associated with halitosis
• Sensitive to Metronidazol and Clindamycin

6. Micromonas micros
• Gram positive anaerobic cocci, part of normal flora in small numbers
• No specific virulence factor but is often found in large numbers during periodontal infections
• Sensitive to Clindamycin, but resistant to erythromycin, bacitracin, and amoxicillin contradictory sensitivity to metronidazol but insensitivity dominates
• Known to be involved in many infections outside the mouth; abdominal, peritoneal, cerebral

7. Fusobacterium nucleatum
• Gram negative rod, anaerobic,
• Unknown virulence factors but their rich adhesine production seems to be important to allow other pathogenic species to proliferate in plaque.
• Sensitive to metronidazol and amoxicillin, insensitive to erythromycin, claritromycin and tetracycline

8. Campylorbacter rectus
• Gram negative bacillus, not strictly anaerobic
• Little known about resistance or virulence factors
• Contradictory infromation as to Antibiotic sensitivity

9. Eubacterium nodatum
• Gram positive, anaerobic cocco-bacillus
• Present in most periodontal infections but no known specific virulence factors
• Sensitive to metronidazol, clindamycin, vancomycin, cefoxitin

10. Eikenella corrodens
• Gram negative bacillus that is facultatively anaerobic
• Virulence factors include inflammation reactions, cytotoxic proteins on exterior membrane
• Adhesins, toxic polysaccharides
• Resistant to metronidazol, erythyromycin, clindamycin and tetracycline, sensitive generally to amoxicillin, cefoxitin and moxifloxacin

11. Capnocytophaga species group
• Gram negative bacilli faultative anaerobes
• Nearly always present in periodontal degeneration, produces tissue degenerating enzymes
• Resistant to clindamycin, metronidazol, sensitive to claritromycin, amoxicillin and ampicillin