Division of Oral Medicine and Pathology, Department of Human Biology andPathophysiology, School of Dentistry, Health Sciences University ofHokkaido, Hokkaido, Japan
Prof. Dr. Yoshihiro Abiko
Division of Oral Medicine and Pathology, Department of Human Biology andPathophysiology, School of Dentistry, Health Sciences University ofHokkaido, Hokkaido, Japan
Introduction:Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) has the propensity to form biofilms, and causes significant mortality and morbidity in the patients with wounds. Our aim was to study the in vitro biofilm-forming ability of S. aureus isolated from wounds of hospitalized patients and their association with antimicrobial resistance. Materials and methods: Forty-three clinical isolates of S. aureus were obtained from 150 pus samples using standard microbiological techniques. Biofilm formation in these isolates was detected by tissue culture plate (TCP) method and tube adherence method (TM). Antimicrobial susceptibility test was performed using the modified Kirby–Bauer disk diffusion method as per Clinical and Laboratory Standards Institute guidelines. MRSA was detected using the cefoxitin disk test. Results: Biofilm formation was observed in 30 (69.8%) and 28 (65.1%) isolates of S. aureus via TCP method and TM, respectively. Biofilm-producing S. aureus exhibited a higher incidence of antimicrobial resistance when compared with the biofilm nonproducers (P<0.05). Importantly, 86.7% of biofilm-producing S. aureus were multidrug resistant (MDR), whereas all the biofilm nonproducers were non-MDR (P<0.05). Large proportions (43.3%) of biofilm producers were identified as MRSA; however, none of the biofilm nonproducers were found to be MRSA (P<0.05). Conclusion: Both the in vitro methods showed that S. aureus isolated from wound infection of hospitalized patients have high degree of biofilm-forming ability. Biofilm-producing strains have very high tendency to exhibit antimicrobial resistance, multidrug resistance and methicillin resistance. Regular surveillance of biofilm formation by S. aureus and their antimicrobial resistance profile may lead to the early treatment of the wound infection.
Psychological stress in a chronic course is implicated in various diseases, such as coronary artery disease, diabetes, ulcerative colitis, and psychosomatic pain disorders. Commensal microbiota in the host tissues interact with each other and maintain overall health. Oral and gut microbiomes are considered as the most ecologically rich and taxonomically diverse microbiota communities in humans. The effects of psychological stress on the gut microbiome have been well documented, and the interaction is commonly referred as the microbiota-gut-brain axis. Like the gut microbiome, the oral microbiome contributes to maintaining both local and systemic health. Although the effects of psychological stress on the oral microbiome have been studied, comprehensive knowledge about the oral-brain axis is lacking. The oral cavity and gut can communicate with each other through the microbiota. Three-way interactions within the oral-gut-brain microbiota might exist in patients with psychological stress and disorders. The effect of psychological stress on the gut and oral microbiomes, and the potential interactions within the oral-gut-brain axis are discussed in this review.