This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Thompson, H L Articles by Wilton, J M Search for Related Content PubMed PubMed Citation Articles by Thompson, H L Articles by Wilton, J M

 Previous Article  |  Next Article 

Infect Immun. 1991 March; 59(3): 932-940

Effects of anaerobiosis and aerobiosis on interactions of human polymorphonuclear leukocytes with the dental plaque bacteria Streptococcus mutans, Capnocytophaga ochracea, and Bacteroides gingivalis.

Medical Research Council Dental Research Unit, London Hospital Medical College, United Kingdom.

ABSTRACT

Human polymorphonuclear leukocytes (PMN) were able to generate and release superoxide anions upon stimulation of Streptococcus mutans, Bacteroides gingivalis, and Capnocytophaga ochracea when incubated aerobically but not when incubated anaerobically. Lysozyme release and phagocytosis by PMN were independent of oxygen, and no difference between PMN incubated aerobically or anaerobically was observed (PMN stimulated by B. gingivalis released 7.6% total lysozyme when aerobic and 6.9% when anaerobic). There were variations in lysozyme release and phagocytosis for the three organisms, particularly for phagocytosis. B. gingivalis and C. ochracea yielded lower phagocytosis values than those for S. mutans, e.g., at 1 h 67% of the initial inoculum of S. mutans was phagocytosed (versus only 40% for B. gingivalis). Transmission electron microscopy showed that both S. mutans and B. gingivalis were internalized into classical phagolysosomes. In contrast, C. ochracea showed two forms of internalization; C. ochracea either formed a classical phagolysosome or was tightly bound in the cytoplasm with no surrounding cell membrane. Intracellular killing of S. mutans and C. ochracea was unaffected by anaerobiosis, but killing of C. ochracea was much lower than that of S. mutans (1 x 10(7) to 2 x 10(7) bacteria killed compared with 5.1 x 10(7) bacteria killed at 6 h). In contrast, a greater number of B. gingivalis was killed in the presence of oxygen (5.3 x 10(7) bacteria were killed when aerobically incubated and 1.9 x 10(7) bacteria were killed when anaerobically incubated). These results suggest that the ability to survive anaerobically may enable some bacteria to evade PMN killing; however, abnormal phagocytosis may represent a more efficient way to evade both oxygen-dependent and -independent killing mechanisms, leading to enhanced virulence of the organism.