Intracerebral hemorrhage and deep microbleeds associated with cnm-positive Streptococcus mutans; a hospital cohort study

• Published in: Scientific reports Vol. 6; no. 1; p. 20074
• Main Authors: Tonomura, Shuichi, Ihara, Masafumi, Kawano, Tomohiro, Tanaka, Tomotaka, Okuno, Yoshinori, Saito, Satoshi, Friedland, Robert P., Kuriyama, Nagato, Nomura, Ryota, Watanabe, Yoshiyuki, Nakano, Kazuhiko, Toyoda, Kazunori, Nagatsuka, Kazuyuki
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 05.02.2016; Nature Publishing Group
• Subjects: 38/22; 45/77; 631/326/41/2531; 692/617/375/380/534; Adhesins, Bacterial - chemistry; Adhesins, Bacterial - genetics; Adhesins, Bacterial - metabolism; Aged; Aged, 80 and over; Brain - diagnostic imaging; C-Reactive Protein - analysis; Carrier Proteins - chemistry; Carrier Proteins - genetics; Carrier Proteins - metabolism; Cerebral Hemorrhage - diagnostic imaging; Cerebral Hemorrhage - etiology; Cohort analysis; Cohort Studies; Collagen; Collagen (type I); Collagen - chemistry; Collagen - metabolism; DNA, Bacterial - metabolism; Female; Hemorrhage; Humanities and Social Sciences; Humans; Infectious diseases; Ischemia; Magnetic Resonance Imaging; Male; Middle Aged; multidisciplinary; Observational studies; Odds Ratio; Polymerase Chain Reaction; Population studies; Protein Binding; Saliva; Saliva - microbiology; Science; Streptococcus; Streptococcus infections; Streptococcus mutans - isolation & purification; Streptococcus mutans - metabolism; Stroke; Stroke - microbiology; Stroke - pathology; Transient ischemic attack
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep20074

Oral infectious diseases are epidemiologically associated with stroke. We previously showed that oral Streptococcus mutans with the cnm gene encoding a collagen-binding Cnm protein induced intracerebral hemorrhage (ICH) experimentally and was also associated with cerebral microbleeds (CMBs) in our population-based cohort study. We therefore investigated the roles of cnm -positive Streptococcus mutans in this single hospital-based, observational study that enrolled 100 acute stroke subjects. The cnm gene in Streptococcus mutans isolated from saliva was screened using PCR techniques and its collagen-binding activities examined. CMBs were evaluated on T2* gradient-recalled echo MRI. One subject withdrew informed consent and 99 subjects (63 males) were analyzed, consisting of 67 subjects with ischemic stroke, 5 with transient ischemic attack and 27 with ICH. Eleven cases showed Streptococcus mutans strains positive for cnm . The presence of cnm -positive Streptococcus mutans was significantly associated with ICH [OR vs. ischemic stroke, 4.5; 95% CI, 1.17–19.1] and increased number of deep CMBs [median (IQR), 3 (2–9) vs. 0 (0–1), p = 0.0002]. In subjects positive for Streptococcus mutans , collagen binding activity was positively correlated with the number of deep CMBs (R 2  = 0.405; p < 0.0001). These results provide further evidence for the key role of oral health in stroke.