Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to inv...Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.展开更多
Objective:To evaluate the level of salivary Mutatis streptococci(MS) after rinsing with xylitol, fluoride,and a combination of xylitol and fluoride solutions,compared with distilled water. Methods:Eighty healthy 8-9 y...Objective:To evaluate the level of salivary Mutatis streptococci(MS) after rinsing with xylitol, fluoride,and a combination of xylitol and fluoride solutions,compared with distilled water. Methods:Eighty healthy 8-9 years old subjects with high level of MS(】 10~5 CFU/mL) were equally divided into 4 groups.Subjects rinsed their moutlis for 1 min with 10 mL of 0.05%(w/v) sodium fluoride(NaF),12.5%(w/v) xylitol or 0.05%(w/v) NoF + 12.5%(w/v) xylitol 3 times daily over 10 weeks.Distilled water rinsed group served as a control.Paraffin-stimulated whole saliva samples were collected at baseline,5 weeks,and 10 weeks after rinsing to determine the level of salivary MS by culturing on Mitis Salivarius Bacitracin agar.The statistical significance was calculated by Kruskol Wallis,Mann Whitney U,and Wilcoxon signed-rank tests at a significant level of P【 0.05.Results:Significant reductions in MS count were observed in subjects using 0.05%NaF + 12.5%xylitol over other groups within 5 weeks and after 10 weeks and 12.5%xylitol alone after 10 weeks compared with baseline.Conclusions:The present study provides evidence for the inhibitory effect of xylitol,used in combination with fluoride,delivered in the form of mouthrinse, on salivary MS in the group of schoolchildren.展开更多
Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strain...Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strains from caries-free subjects (115) and another set from caries-active subjects (165) were isolated. Each strain was characterized for three virulence determi-nants. The clinical bacteria were then cocultured by three strains exhibiting the highest levels of virulence. Isolate colonies of last filial generation bacteria were enrichment-incubated and estimated for virulence again. RAPD-PCR and MLEE analyses were processed for parental bacteria and last filial genera-tion one. Results: No difference associated with caries activity of the subjects from whom the isolates origi-nated. Virulent properties of a filial generation strains was not different in the same generation, but was very different from their parent strains. Conclu-sion: The coexist properties of virulent polyclonal strain of MS may hold in a very general conditional sense in a dental plaque ecosystem in vivo, however, one of the co-culture strains may became dominant and displa- ced the others as the result of continuous ecological succession in vitro.展开更多
Children with congenital heart diseases (CHD) are considered to be at higher risk of development of a Bacterial Endocarditic (BE) from infectious diseases of the oral cavity and following dental treatments. They repre...Children with congenital heart diseases (CHD) are considered to be at higher risk of development of a Bacterial Endocarditic (BE) from infectious diseases of the oral cavity and following dental treatments. They represent the largest group of patients with special medical needs who appear in the daily dental practice. Maintenance of oral health and oral hygiene is suitable to reduce the incidence of bacteremia. Oral hygiene is more important in reducing the risk of BE than the administration of antibiotic-prophylaxis before dental procedures. The purpose of this study was to identify the strains of streptococci viridians group from dental plaque and their amoxicillin resistance at children with congenital heart disease. The study was carried out in University Dentistry Clinical Center of Kosova, Department of Pediatric Dentistry in cooperation with the Micro-biologic Department. Participants in this study (n = 90) were children between 6 - 15 years old, divided in the control group of healthy children (n = 30), and two study groups, first group, children with CHD who have not taken antibiotics within last three months (n = 30) and second group, children with CHD who have taken antibiotics within three months (n = 30). The gram positive cocci were identified using the automated system, VITEK 2 (BioMerux), while for determining amoxicillin resistance cocci the disc diffusion method was used. By analyzing the three groups of children regarding isolated dental plaque streptococci, in general the Viridans group of streptococci (VGS) has dominated our results, with a higher percentage of streptococcus Mitis group (37.2%). The highest resistance of VGS against amoxicilin was in the group of children with CHD, which have been using antibiotics within 3 months (23.3%). In the other two groups the resistance against amoxicillin was found in a lower percentage (3.3%). Based on the results of our study we can conclude that frequent use of amoxicillin may result in an increasing antimicrobial resistance of streptococci.展开更多
Bacterial infection associated with the use of medical or dental devices is a serious concern.Although devices made of ethylene vinyl acetate（EVA） are often used in the oral cavity,there are no established standards...Bacterial infection associated with the use of medical or dental devices is a serious concern.Although devices made of ethylene vinyl acetate（EVA） are often used in the oral cavity,there are no established standards for their storage.We investigated bacterial survival on EVA sheets under various storage conditions to establish a standard for hygienic storage of such dental devices.Bacterial counts were evaluated,which showed a significant decrease after washing with sterilized water,mechanical brushing and rinsing,and using Mouthguard Cleaner as compared to untreated samples.In addition,no bacteria were detected on samples stored 2 days or longer in a ventilated environment,whereas they were detected for up to 14 days on samples without any cleaning stored in a closed environment.Bacterial counts for the untreated samples gradually declined,while surviving bacteria on samples treated with sterilized water and mechanical brushing showed a rapid decrease.Additionally,bacterial identification using polymerase chain reaction（PCR） revealed that Streptococcus oralis was dominantly detected on salivary samples after 14 days of storage among both two subjects.For effective hygienic storage of dental devices made of EVA,washing with sterilized water is important to remove absorbed salivary compounds along with storage in a ventilated environment.展开更多
Aim: The purpose of this study was to assess chlorhexidine effects on plaque index and salivary levels of mutans streptococci (MS) when used as the immersion solution for removable orthodontic appliances and added to ...Aim: The purpose of this study was to assess chlorhexidine effects on plaque index and salivary levels of mutans streptococci (MS) when used as the immersion solution for removable orthodontic appliances and added to their acrylic resin composition. Methods: Forty-five patients (6 to 12 years old) were randomly assigned into three groups with 15 patients each. Group I (control)—without orthodontic appliances disinfection;Group II—removable orthodontic appliances which had been immersed in 0.12% chlorhexidine digluconate overnight (8 hours), and Group III—orthodontic appliances in which 0.12% chlorhexidine digluconate solution had been incorporated into their resin composition. Saliva was collected for quantification of MS and evaluation of plaque index was performed before and after installation of orthodontic appliance at 0, 2, 4, 6, 8, and 10 weeks. Data were analyzed by using analysis of variance. Results: Number of MS colonies in saliva and plaque index showed no statistically differences among groups at the different periods (p > 0.05). Conclusions: It could be concluded that chlorhexidine incorporation into the acrylic resin of removable orthodontic appliances at 0.12% concentration and immersion of the appliance into 0.12% chlorhexidine solution were not effective in reducing plaque index and the number of MS in saliva.展开更多
Granulicatella species,previously classified as nutritionally variant streptococci,have emerged as important opportunistic pathogens.Although typically part of the normal oral,gastrointestinal,and genitourinary flora,...Granulicatella species,previously classified as nutritionally variant streptococci,have emerged as important opportunistic pathogens.Although typically part of the normal oral,gastrointestinal,and genitourinary flora,these fastidious Gram-positive cocci can cause serious infections in both immunocompetent and immunocompromised individuals.Their identification often proves difficult due to slow growth and unusual nutritional requirements,which limit the reliability of conventional culture methods.This narrative review consolidates data from over 100 case reports and clinical studies to present a comprehensive overview of Granulicatella infections.Infective endocarditis appears as the most frequently reported and life-threatening condition,often affecting the aortic and mitral valves.Patients with prosthetic valves or congenital heart defects face a higher risk.Delayed diagnosis frequently results in complications such as heart failure,systemic emboli,and renal dysfunction.Granulicatella species also contribute to osteomyelitis,pulmonary infections,brain abscesses,gastrointestinal sepsis,and infections related to implanted medical devices.Effective management typically involves beta-lactam antibiotics combined with aminoglycosides,although antimicrobial resistance remains a concern.Surgical intervention often proves necessary,especially in cases with prosthetic material or severe complications.Outcomes are generally favorable when infections are identified early and managed effectively.However,delayed recognition and suboptimal therapy continue to contribute to poor prognoses in some patients.This review emphasizes the need to improve clinical awareness and establish standardized diagnostic and therapeutic approaches to address the challenges posed by Granulicatella infections.展开更多
Granulicatella adiacens (G. adiacens), formerly classified as a nutritionally variant streptococci (NVS), is a commensal organism in the mouth. It is known to be a rare cause of infective endocarditis (IE). This case ...Granulicatella adiacens (G. adiacens), formerly classified as a nutritionally variant streptococci (NVS), is a commensal organism in the mouth. It is known to be a rare cause of infective endocarditis (IE). This case report presents a case of IE caused by G. adiacens in a 63-year-old man with mitral valve prolapse (MVP), severe mitral regurgitation (MR), and dual vessel disease (DVD). G. adiacens was isolated from two of three blood cultures, and the organism was sensitive to penicillin, vancomycin, cefotaxime, and gentamicin. He was successfully treated with a combination of ceftriaxone and gentamicin. Prompt identification of the organism and determination of antibiotic sensitivity pattern led to successful treatment. This case report showcases the challenges in diagnosis, and treatment, giving insight to healthcare providers on a rare entity.展开更多
文摘Group A streptococcus （GAS） causes a wide range of diseases in the human population. GAS diseases are more common in children than in adults, with clinical manifestations ranging from pharyngitis and impetigo to invasive infections and post streptococcal sequelae, such as acute rheumatic fever and acute post-streptococcal glomerulonephritis[1]. GAS harbors a host of virulence factors that contribute to its complex pathogenicity and differences in the disease severity and frequency. M protein, one of the major virulence factors, is encoded by the emm gene induces a type of specific host immune response and confers antiphagocytic properties.
基金Supported by Faculty of Dentistry,Mahidol University,2008
文摘Objective:To evaluate the level of salivary Mutatis streptococci(MS) after rinsing with xylitol, fluoride,and a combination of xylitol and fluoride solutions,compared with distilled water. Methods:Eighty healthy 8-9 years old subjects with high level of MS(】 10~5 CFU/mL) were equally divided into 4 groups.Subjects rinsed their moutlis for 1 min with 10 mL of 0.05%(w/v) sodium fluoride(NaF),12.5%(w/v) xylitol or 0.05%(w/v) NoF + 12.5%(w/v) xylitol 3 times daily over 10 weeks.Distilled water rinsed group served as a control.Paraffin-stimulated whole saliva samples were collected at baseline,5 weeks,and 10 weeks after rinsing to determine the level of salivary MS by culturing on Mitis Salivarius Bacitracin agar.The statistical significance was calculated by Kruskol Wallis,Mann Whitney U,and Wilcoxon signed-rank tests at a significant level of P【 0.05.Results:Significant reductions in MS count were observed in subjects using 0.05%NaF + 12.5%xylitol over other groups within 5 weeks and after 10 weeks and 12.5%xylitol alone after 10 weeks compared with baseline.Conclusions:The present study provides evidence for the inhibitory effect of xylitol,used in combination with fluoride,delivered in the form of mouthrinse, on salivary MS in the group of schoolchildren.
文摘Purpose:To examine selected putative virulent prop-erties of mutans streptococci in two groups with dif-ferent caries activity and to examine co-culture hy-bridization of the strains in vitro. Methods: A set of strains from caries-free subjects (115) and another set from caries-active subjects (165) were isolated. Each strain was characterized for three virulence determi-nants. The clinical bacteria were then cocultured by three strains exhibiting the highest levels of virulence. Isolate colonies of last filial generation bacteria were enrichment-incubated and estimated for virulence again. RAPD-PCR and MLEE analyses were processed for parental bacteria and last filial genera-tion one. Results: No difference associated with caries activity of the subjects from whom the isolates origi-nated. Virulent properties of a filial generation strains was not different in the same generation, but was very different from their parent strains. Conclu-sion: The coexist properties of virulent polyclonal strain of MS may hold in a very general conditional sense in a dental plaque ecosystem in vivo, however, one of the co-culture strains may became dominant and displa- ced the others as the result of continuous ecological succession in vitro.
文摘Children with congenital heart diseases (CHD) are considered to be at higher risk of development of a Bacterial Endocarditic (BE) from infectious diseases of the oral cavity and following dental treatments. They represent the largest group of patients with special medical needs who appear in the daily dental practice. Maintenance of oral health and oral hygiene is suitable to reduce the incidence of bacteremia. Oral hygiene is more important in reducing the risk of BE than the administration of antibiotic-prophylaxis before dental procedures. The purpose of this study was to identify the strains of streptococci viridians group from dental plaque and their amoxicillin resistance at children with congenital heart disease. The study was carried out in University Dentistry Clinical Center of Kosova, Department of Pediatric Dentistry in cooperation with the Micro-biologic Department. Participants in this study (n = 90) were children between 6 - 15 years old, divided in the control group of healthy children (n = 30), and two study groups, first group, children with CHD who have not taken antibiotics within last three months (n = 30) and second group, children with CHD who have taken antibiotics within three months (n = 30). The gram positive cocci were identified using the automated system, VITEK 2 (BioMerux), while for determining amoxicillin resistance cocci the disc diffusion method was used. By analyzing the three groups of children regarding isolated dental plaque streptococci, in general the Viridans group of streptococci (VGS) has dominated our results, with a higher percentage of streptococcus Mitis group (37.2%). The highest resistance of VGS against amoxicilin was in the group of children with CHD, which have been using antibiotics within 3 months (23.3%). In the other two groups the resistance against amoxicillin was found in a lower percentage (3.3%). Based on the results of our study we can conclude that frequent use of amoxicillin may result in an increasing antimicrobial resistance of streptococci.
文摘Bacterial infection associated with the use of medical or dental devices is a serious concern.Although devices made of ethylene vinyl acetate（EVA） are often used in the oral cavity,there are no established standards for their storage.We investigated bacterial survival on EVA sheets under various storage conditions to establish a standard for hygienic storage of such dental devices.Bacterial counts were evaluated,which showed a significant decrease after washing with sterilized water,mechanical brushing and rinsing,and using Mouthguard Cleaner as compared to untreated samples.In addition,no bacteria were detected on samples stored 2 days or longer in a ventilated environment,whereas they were detected for up to 14 days on samples without any cleaning stored in a closed environment.Bacterial counts for the untreated samples gradually declined,while surviving bacteria on samples treated with sterilized water and mechanical brushing showed a rapid decrease.Additionally,bacterial identification using polymerase chain reaction（PCR） revealed that Streptococcus oralis was dominantly detected on salivary samples after 14 days of storage among both two subjects.For effective hygienic storage of dental devices made of EVA,washing with sterilized water is important to remove absorbed salivary compounds along with storage in a ventilated environment.
文摘Aim: The purpose of this study was to assess chlorhexidine effects on plaque index and salivary levels of mutans streptococci (MS) when used as the immersion solution for removable orthodontic appliances and added to their acrylic resin composition. Methods: Forty-five patients (6 to 12 years old) were randomly assigned into three groups with 15 patients each. Group I (control)—without orthodontic appliances disinfection;Group II—removable orthodontic appliances which had been immersed in 0.12% chlorhexidine digluconate overnight (8 hours), and Group III—orthodontic appliances in which 0.12% chlorhexidine digluconate solution had been incorporated into their resin composition. Saliva was collected for quantification of MS and evaluation of plaque index was performed before and after installation of orthodontic appliance at 0, 2, 4, 6, 8, and 10 weeks. Data were analyzed by using analysis of variance. Results: Number of MS colonies in saliva and plaque index showed no statistically differences among groups at the different periods (p > 0.05). Conclusions: It could be concluded that chlorhexidine incorporation into the acrylic resin of removable orthodontic appliances at 0.12% concentration and immersion of the appliance into 0.12% chlorhexidine solution were not effective in reducing plaque index and the number of MS in saliva.
文摘Granulicatella species,previously classified as nutritionally variant streptococci,have emerged as important opportunistic pathogens.Although typically part of the normal oral,gastrointestinal,and genitourinary flora,these fastidious Gram-positive cocci can cause serious infections in both immunocompetent and immunocompromised individuals.Their identification often proves difficult due to slow growth and unusual nutritional requirements,which limit the reliability of conventional culture methods.This narrative review consolidates data from over 100 case reports and clinical studies to present a comprehensive overview of Granulicatella infections.Infective endocarditis appears as the most frequently reported and life-threatening condition,often affecting the aortic and mitral valves.Patients with prosthetic valves or congenital heart defects face a higher risk.Delayed diagnosis frequently results in complications such as heart failure,systemic emboli,and renal dysfunction.Granulicatella species also contribute to osteomyelitis,pulmonary infections,brain abscesses,gastrointestinal sepsis,and infections related to implanted medical devices.Effective management typically involves beta-lactam antibiotics combined with aminoglycosides,although antimicrobial resistance remains a concern.Surgical intervention often proves necessary,especially in cases with prosthetic material or severe complications.Outcomes are generally favorable when infections are identified early and managed effectively.However,delayed recognition and suboptimal therapy continue to contribute to poor prognoses in some patients.This review emphasizes the need to improve clinical awareness and establish standardized diagnostic and therapeutic approaches to address the challenges posed by Granulicatella infections.
文摘Granulicatella adiacens (G. adiacens), formerly classified as a nutritionally variant streptococci (NVS), is a commensal organism in the mouth. It is known to be a rare cause of infective endocarditis (IE). This case report presents a case of IE caused by G. adiacens in a 63-year-old man with mitral valve prolapse (MVP), severe mitral regurgitation (MR), and dual vessel disease (DVD). G. adiacens was isolated from two of three blood cultures, and the organism was sensitive to penicillin, vancomycin, cefotaxime, and gentamicin. He was successfully treated with a combination of ceftriaxone and gentamicin. Prompt identification of the organism and determination of antibiotic sensitivity pattern led to successful treatment. This case report showcases the challenges in diagnosis, and treatment, giving insight to healthcare providers on a rare entity.
