Relationship between oxygen tension and subgingival bacterial flora in untreated human periodontal pockets

Abstract

The predominance of anaerobic bacteria in subgingival plaque samples suggests that the pocket environment is anaerobic. In the present investigation, a small oxygen tension (PO2) electrode was inserted into the base of the pocket and the P02 was recorded. In addition, the plaque in these pockets was examined culturally and microscopically. The oxygen tension at the bottom of 36 pockets (5 to 10 mm in depth) ranged from S to 27 mmHg (1 mmHg = 133.3 Pa) with a mean value of 13.3 mmHg. Moderate pockets (5 and 6 mm) exhibited a mean PO2 of 15.7 mmHg, which was significantly higher than the 12.0 mmHg found in the deeper pockets. The deep pockets had higher percentages of spirochetes and Bacteroides intermedius, whereas the moderate pockets had elevated proportions of Actinomyces naeslundii and Streptococcus mutans. The sites with oxygen tensions equal to or less than 15 mmHg had significantly higher percentages of spirochetes, whereas the microaerophilic Capnocytophaga species were found in pockets with a P02 greater than 15 mmHg. The presence of bleeding in the pocket was associated with higher proportions of B. intermedius, Capnocytophaga sp., and A. naeslundii. These P02 readings of periodontal pockets indicated that there is a spectrum Of PO2 values which seem to define, in a general way, the microbiological composition of the pocket.on July 16, 2020 by guest http://iai.asm.org/ Downloaded from RESULTSThe PO2 at the bottom of the untreated pockets ranged from 5 to 27 mmHg, with a mean value of 13.3 mmHg. The 95% confidence limit for the mean P02 was between 12.3 and 14.2 INFECT. IMMUN.on July 16, 2020 by guest http://iai.asm.org/ Downloaded from

The aetiopathogenesis of equine periodontal disease – a fresh perspective

“…Significant local environmental changes occur during the development of periodontal pockets (Loesche et al 1983), which may be especially deep around equine cheek teeth (Cox et al 2012). The anaerobic or partially aerobic environment of deep human periodontal pockets encourages invasion and proliferation of microaerophilic organisms, anaerobes and spirochetes, while the environment of the general oral cavity supports a significantly different microbiota (Loesche et al 1983).…”

“…Significant local environmental changes occur during the development of periodontal pockets (Loesche et al 1983), which may be especially deep around equine cheek teeth (Cox et al 2012). The anaerobic or partially aerobic environment of deep human periodontal pockets encourages invasion and proliferation of microaerophilic organisms, anaerobes and spirochetes, while the environment of the general oral cavity supports a significantly different microbiota (Loesche et al 1983). Another hypothesis that can be applied to the diseased oral microbiome is the keystone pathogen hypothesis, which maintains that certain pathogens existing at low abundance in the oral cavity may modulate their environment, disturbing the normally symbiotic relationship between the bacteria of the oral cavity, creating a state of dysbiosis (dysregulation of commensal oral bacteria) thus contributing to the development of inflammatory disease.…”

Hemin nutritional stress inhibits bacterial invasion of radicular dentine by two endodontic anaerobes

“…Studies have demonstrated that tubule invasion is associated with specific bacterial cell wall-polypeptide interactions with unmineralized collagen (Love et al 1997) and other bacteria (Love et al 2000), and bacterial interactions with various molecules found in tissue fluid, dentinal fluid and saliva (Love 2001(Love , 2002. The presence of an appropriate nutritional supply in the environment influences bacterial growth (Loesche et al 1983, ter Steeg et al 1987 and may influence disease progression. Studies examining the bacterial flora of carious coronal dentine show that facultative species that primarily obtain energy from fermenting carbohydrates, for example Streptococcus spp., are mainly located in superficial dentine whilst fastidious obligate anaerobic bacteria that can metabolize host-derived amino acids and peptides, such as Peptostreptococcus micros and Prevotella intermedia, are located in deeper dentine (Edwardsson 1987, Ozaki et al 1994.…”

Microaerophilic growth of Wolinella recta ATCC 33238

“…The majority of the isolates from subgingival samples belong to Gram-negative, anaerobic rods [3][4][5][6], indicating that the periodontal pocket is a predominantly anaerobic environment. Yet, measurable quantities of oxygen have been demonstrated in such pockets [6,7]: oxygen tensions ranged from 7 to 36 mbar with a mean value of 18 mbar (1.8% 02). Moreover, a relationship between the actual pO 2 values and microbial communities in the pockets was observed [6].…”

“…Yet, measurable quantities of oxygen have been demonstrated in such pockets [6,7]: oxygen tensions ranged from 7 to 36 mbar with a mean value of 18 mbar (1.8% 02). Moreover, a relationship between the actual pO 2 values and microbial communities in the pockets was observed [6]. Therefore, the physiological response of subgingival anaerobic organisms to low oxygen tensions may represent one of the possible key properties to survival or predominance in the microbial community of periodontal pockets.…”