[Role and related mechanisms of LiaSR two-component system in acid tolerance and biofilm formation of Streptococcus mutans].

Objective: To investigate the role and related mechanisms of the LiaSR two-component system in acid tolerance and biofilm formation abilities of Streptococcus mutans (Sm) 593. Methods: The growth curves of various Sm strains in pH=5.5 brian heart infusion (BHI) medium were analyzed. And colony forming unit (CFU) was also performed to evaluate the acid tolerance of Sm. Laurdan probe, H+-K+adenosine triphosphate (ATP)ase activity analysis kit, proton permeability assay and real-time fluorescence quantitative PCR (RT-qPCR) were conducted to detect the acid tolerant mechanisms of LiaSR two-component system in Sm. Crystal violet staining, CFU, SYTOX probe and anthrone-sulfuric method were used to analyze the properties and structures of the Sm biofilms. RT-qPCR was conducted to detect the expression levels of underlying regulated genes. Results: The growth of mutants in acidic BHI were inhibited (P<0.05). The acid tolerance of mutants significantly decreased compared to the wild-type strain (P<0.05). In mutants, the activity of H+-ATPase (917.06±59.53 and 469.53±47.65) were elevated by 7.22-folds and 3.70-folds compared to the wild-type strain (127.00±50.71) (P<0.001, P<0.001) and the encoded gene atpD (3.39±0.21 and 1.94±0.17) were also elevated by 3.39-folds and 1.94-folds compared to the wild-type strain (1.00±0.15) (P<0.001, P=0.001). The Laurdan generalized polarization of mutants (0.18±0.04 and 0.18±0.05) increased significantly compared to the wild-type strain (0.08±0.05) (P=0.006, P=0.003) and the expression levels of fabM gene were decreased in mutants (0.52±0.11 and 0.57±0.05) by 1/2 (P=0.014, P=0.022). In liaR deletion mutant, the reduced terminal pH (4.76±0.01) can also be observed (P<0.001). The total amount of the biofilms of three Sm didn't show significant differences (P>0.05). But the number of viable bacteria of mutants' biofilms were decreased [Sm 593: (12.00±2.80)×107 CFU/ml; Sm ΔliaS: (2.95±1.13)×107 CFU/ml; Sm ΔliaR: (7.25±1.60)×107 CFU/ml] (P=0.001, P=0.024). The extracellular DNA were increased by 18.00-folds and 6.50-folds in mutants' biofilms (128.73±15.65 and 46.38±5.52) compared to the wild-type strain (7.16±3.62) (P<0.001, P=0.003). Water-soluble exopolysaccharides could be found up-regulated in liaS deletion mutant [(138.73±10.12) µg/ml] (P=0.003) along with the expression level of gtfC gene (1.65±0.39) (P=0.014). The expression level of gtfD were elevated by 47.43-folds and 16.90-folds in mutants (P<0.001, P=0.010). Conclusions: The LiaSR two-component system can promote the expression of fabM gene and increase the fluidity of Sm which contributes to acid tolerance. The LiaR can also decrease the proton permeability and restrict the entrance of H+. The LiaSR two-component system can negatively regulate the production of the extracellular matrix in Sm biofilm.

Diminutive Incision Acromioplasty Assisted with Arthroscopy in the Treatment of Chinese Patients with Subacromial Impingement Syndrome / Acromioplastia de Incisión Diminuta Asistida con Artroscopia en el Tratamiento de Pacientes Chinos con Síndrome de Pinzamiento Subacromial

ABSTRACT Background: Many causes can lead to shoulder pain and subacromial impingement syndrome (SIS) is the most frequently recorded disorders. The aim of this study was to evaluate the clinical effects of diminutive incision acromioplasty assisted with arthroscopy for the treatment of Chinese patients with subacromial impingement syndrome. Subject and Methods: Twenty-two patients with 24-painful shoulders subacromial impingement syndrome were enrolled. All painful shoulders were in Grades II (8) and III (16) according to Neer's classification. Detailed physical examination was performed. Conventional radiography and subsequent magnetic resonance imaging (MRI) of the shoulder region of all patients were done. The University of California at Los Angeles Shoulder (UCLA) score system was used for all patients to evaluate their satisfaction after surgery. The preoperative recordings of the UCLA scores were collected and all enrolled cases including 24-painful shoulders were available for follow-up in 1, 3, 6, 12 months after surgery. Results: According to the UCLA scoring system, the symptom of all painful shoulders were improved after one year postoperatively. The average score before surgery from 15.4 points increased to 31.2 points postoperatively, showing a statistical difference (p < 0.05). Conclusions: A diminutive incision acromioplasty assisted with arthroscopy is a reliable approach to treat Chinese patients with subacromial impingement syndrome. All painful shoulders were obviously improved in one year after surgery.

ABSTRACT Antecedentes: Muchas causas pueden provocar dolor de hombro y síndrome de compresión subacromial (SIS) es el trastorno más frecuentemente registrado. El objetivo de este estudio fue evaluar la clínica. Efectos de la acromioplastia con incisión diminuta asistida con artroscopia para el tratamiento de Pacientes chinos con síndrome de pinzamiento subacromial. Sujeto y métodos: Se incluyeron veintidós pacientes con síndrome de afectación subacromial de 24-hombros dolorosos. Todos los hombros dolorosos estaban en Grados II (8) y III (16) de acuerdo con la clasificación de Neer. Se realizó examen físico detallado. Se realizaron radiografías convencionales y, posteriormente, imágenes de resonancia magnética (IRM) de la región del hombro de todos los pacientes. El sistema de puntuación de la Universidad de California en Los Angeles Shoulder (UCLA) se utilizó para que todos los pacientes evaluaran su satisfacción después de la cirugía. Los registros preoperatorios de las puntuaciones de UCLA se recopilaron y todos los casos incluidos, incluidos 24-hombros dolorosos, estaban disponibles para el seguimiento en 1, 3, 6 y 12 meses después de la cirugía. Resultados: De acuerdo con el sistema de puntuación de UCLA, el síntoma de todos los hombros dolorosos mejoró después de un año después de la operación. La puntuación promedio antes de la cirugía de 15.4 puntos aumentó a 31.2 puntos después de la operación, mostrando una diferencia estadística (p < 0.05) Conclusiones: Una acromioplastia de incisión diminuta asistida con artroscopia es un enfoque confiable para tratar a pacientes chinos con síndrome de pinzamiento subacromial. Todas las lesiones dolorosas se mejoraron obviamente en un año después de la cirugía.