[Creation of a molecular genetic test system for early diagnosis and evaluation of the effectiveness of treatment of inflammatory periodontal diseases.]

Inflammatory periodontal diseases represent a serious dental and general medical problem due to the high prevalence among the adult population, the presence of clinical forms leading to the destruction of the dentition and tooth loss, insufficient treatment effectiveness and the frequency of relapse, including in connection with the formation of biofilms. A molecular genetic test system has been developed to evaluate the content of periodontopathogenic microorganisms Porphyromonas gingivalis, Treponema denticola, Streptococcus oralis, Streptococcus sanguis and Streptococcus sobrinus in the contents of periodontal pockets. The analytical characteristics of the test system were determined, and testing was carried out on clinical samples of patients with chronic generalized periodontitis of moderate severity. The constructed diagnostic kit allowed us to conduct a comparative analysis of the effectiveness of various types of treatment of inflammatory periodontal diseases based on quantitative data on the content of bacteria in the contents of periodontal pockets.

Biofilm formation on polyetheretherketone and titanium surfaces

Objective

Polyetheretherketone (PEEK) is a polymer used in devices in orthopedic and dental rehabilitation. The aim of this in vitro study was to compare biofilm formation by a range of important oral bacterial species on PEEK, blasted PEEK, commercially pure titanium (cp-Ti), and titanium-6 aluminium-4 vanadium (Ti6Al4V).

Material and methods

Coin-shaped samples were manufactured, and the surfaces were characterized using optical interferometry, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and contact angle measurements. Bacterial species of Streptococcus sanguinis, Streptococcus oralis, Enterococcus faecalis, and Streptococcus gordonii were cultured on the four material surfaces for varying amounts of time. Biofilms were quantified following staining with crystal violet.

Results

Roughness and contact angle results showed blasted PEEK > PEEK > cp-Ti = Ti6Al4V. There was increased biofilm formation on blasted PEEK by S. sanguinis, S. oralis, and S. gordonii, whereas the bacterial adhesion was similar on PEEK, cp-Ti, and Ti6Al4V. The bacterial growth of E. faecalis was significantly higher on cp-Ti compared with the other three groups.

Conclusion

The results, taking into consideration the biofilm formation, suggest that PEEK should perform as well as cp-Ti or TiAl6V4 when used as a dental restorative material.

Osteomyelitis of the mandible secondary to malignant infantile osteopetrosis in an adult

Malignant infantile osteopetrosis (MIOP), an autosomal-recessive disorder, is extremely rare, presenting early in life with extreme sclerosis of the skeleton and reduced activity of osteoclasts. It was first described by Albers Schonberg in 1904. Disease manifestations include compensatory extramedullary haematopoiesis at sites such as the liver and spleen, hepatosplenomegaly, anaemia and thrombocytopaenia. Neurological manifestations can also occur due to narrowing of osseous foramina resulting in visual impairment, hearing loss, facial palsy and hydrocephalus. In addition, growth retardation and recurrent infections requiring long-term antibiotic use are common. The incidence of MIOP is 1/2 000 000 and if untreated, then it has a fatal outcome, with the majority of cases occurring within the first 5 years of life. At present, the only potentially curative option is a haematopoietic stem cell transplant. We present a 21-year-old woman, diagnosed with malignant infantile osteopetrosis, due to a mutation in the T-cell immune regulator 1 gene when aged 6 weeks, presenting with chronic osteomyelitis of her left mandible. As malignant infantile osteopetrosis has a high mortality in infancy, we felt it prudent to report this rare case in a patient surviving to adulthood.

A Descriptive Study of Chlorhexidine as a Disinfectant in Cleft Palate Surgery

OBJECTIVES

Chlorhexidine is seen as the golden standard of disinfectants. It is widely used to clean surgical sites; however, many studies indicate resistance of pathogens to chlorhexidine. One study indicated that pathogenic microorganisms were isolated from the soft palate cleft region in 57% of patients with facial clefts. The objectives of our study were to determine (1) if chlorhexidine application is effective in removing pathogens from the surgical site in these patients, and (2) if any pathogens are isolated, determine if they are resistant to other antimicrobials.

DESIGN

A descriptive observational study.

SETTINGS

A private practice that specializes in facial cleft surgery, with a country-wide patient base. All procedures were executed by one oral and maxillofacial surgeon.

PARTICIPANTS

All patients (N=50) who presented for primary repair of the soft palate cleft were included in the study.

INCLUSION CRITERIA

written consent from parent(s), and patient cleared as systemically healthy by a pediatric physician.

EXCLUSION CRITERIA

patient(s) with systemic infections (eg, flu) and/or any local infections (eg, tonsillitis). There were 25 males and 25 females with an average age of 7 months and 16 days included in the study.

METHODS

Swabs were taken from the surgical site of all 50 patients with cleft soft palate and were sent for culture, identification and antimicrobial sensitivity. The swabs were taken before disinfecting the site as well as after 2 minutes of disinfecting the surgical site with chlorhexidine. Results were compared against each other.

RESULTS

Positive cultures with 28 different pathogenic microorganisms that were identified in 47 patients before cleaning the surgical site with the chlorhexidine. The most dominant pathogens were K. pneumonia (n=22), H. influenza (n=18) and S. aureus (n=10). Of the pathogens found, 13 (46%) were still present on the swabs taken after disinfecting with chlorhexidine. K. pneumonia (n= 13), H. influenza (n=11) and S. aureus (n=9) were still the most prevalent pathogens.

CONCLUSIONS

This study demonstrated that 61 of the total of 113 pathogens isolated (54%), survived after 2 minutes of disinfecting the surgical and surrounding area with chlorhexidine, thus intensifying the chances of post-operative infection.

Isolated Left Atrial Infective Mural Endocarditis

A 52-year-old man presented with a fever and malaise. Transthoracic echocardiogram was performed because of a holosystolic murmur, which showed mitral valve prolapse and a regurgitation jet toward the posterior wall of the left atrium. There was no apparent vegetation at any valves. Blood cultures were positive for Streptococcus mitis/oralis. Transesophageal echocardiogram revealed vegetation only at the posterior wall of the left atrium exposed to the mitral regurgitant jet. We diagnosed this condition as infective mural endocarditis. This case highlighted the need for a detailed observation of the valves and the atrial wall when infective endocarditis is suspected.

[Reconstruction of Anterior Mitral Leaflet Using Fresh Autologous Pericardial Patch for Active Infective Endocarditis;Report of a Case]

Several reports have described that the prognosis of patients with mitral valve regurgitation due to active infective endocarditis (IE) is better after mitral valve plasty (MVP) than replacement (MVR). However, extensive destruction of valve tissue might cause difficulties with MVP. We repaired a widely-affected anterior mitral leaflet (AML) using an autologous pericardial patch. A 44-year-old woman with mitral regurgitation presented with prolonged fever and backache. We made a diagnosis of active IE accompanied by mitral valve regurgitation. We performed MVP, widely resected the infected areas of the AML, and reconstructed the defective area using the pericardial patch. She was discharged after four weeks of antibiotic therapy, when she was free of recurrence. The pericardial patch facilitated MVP and was effective for treating mitral valve regurgitation due to active IE.

An in vivo comparison of internal bacterial colonization in two dental implant systems: identification of a pathogenic reservoir

OBJECTIVES

The aim of this study was to compare internal bacterial colonization in two implant systems, one screw root form (SRF) with an external hexagon connection and one plateau root form (PRF) with a Morse taper internal connection.

MATERIALS AND METHODS

Thirty-two implants; 12 SRF and 20 PRF, were sampled in 15 patients. All implants had been in function for at least 6 months prior to sampling. The implant restoration was removed and 10 µl of sterile saline was introduced into the implant well via a sterile glass syringe. The saline was drawn back up and transferred to the laboratory for microbiological analysis. The number of aerobic and anaerobic colony forming units per millilitre was determined and the dominant micro-organism in each sample was identified by 16s rRNA gene amplicon sequencing.

RESULTS

There was a significant difference between bleeding on probing around the SRF implants (3%) and the PRF implants (28%) (p = 0.0496). Bacterial colonization was identified at 11 SRF and 19 PRF implants. The numbers of anaerobic bacteria recovered from PRF implants was significantly higher than that from SRF implants (p = 0.0002). Streptococcus species and Enterococcus faecalis were found to dominate.

CONCLUSIONS

This in vivo study demonstrated bacterial colonization in both types of implant systems, irrespective of the type of connection. Significantly greater anaerobic counts were found in the Morse taper internal connection implants.

Quantification and qualification of bacteria trapped in chewed gum

Chewing of gum contributes to the maintenance of oral health. Many oral diseases, including caries and periodontal disease, are caused by bacteria. However, it is unknown whether chewing of gum can remove bacteria from the oral cavity. Here, we hypothesize that chewing of gum can trap bacteria and remove them from the oral cavity. To test this hypothesis, we developed two methods to quantify numbers of bacteria trapped in chewed gum. In the first method, known numbers of bacteria were finger-chewed into gum and chewed gums were molded to standard dimensions, sonicated and plated to determine numbers of colony-forming-units incorporated, yielding calibration curves of colony-forming-units retrieved versus finger-chewed in. In a second method, calibration curves were created by finger-chewing known numbers of bacteria into gum and subsequently dissolving the gum in a mixture of chloroform and tris-ethylenediaminetetraacetic-acid (TE)-buffer. The TE-buffer was analyzed using quantitative Polymerase-Chain-Reaction (qPCR), yielding calibration curves of total numbers of bacteria versus finger-chewed in. Next, five volunteers were requested to chew gum up to 10 min after which numbers of colony-forming-units and total numbers of bacteria trapped in chewed gum were determined using the above methods. The qPCR method, involving both dead and live bacteria yielded higher numbers of retrieved bacteria than plating, involving only viable bacteria. Numbers of trapped bacteria were maximal during initial chewing after which a slow decrease over time up to 10 min was observed. Around 10(8) bacteria were detected per gum piece depending on the method and gum considered. The number of species trapped in chewed gum increased with chewing time. Trapped bacteria were clearly visualized in chewed gum using scanning-electron-microscopy. Summarizing, using novel methods to quantify and qualify oral bacteria trapped in chewed gum, the hypothesis is confirmed that chewing of gum can trap and remove bacteria from the oral cavity.

Association between polycystic ovary syndrome, oral microbiota and systemic antibody responses

Polycystic ovary syndrome (PCOS) is a hormonal disorder of women that not only is the leading cause of infertility but also shows a reciprocal link with oral health. This study aimed to investigate the hypothesis that the levels of putative periodontal pathogens in saliva and their antibody response in serum are elevated in PCOS, compared to systemic health. A total of 125 women were included in four groups; 45 women with PCOS and healthy periodontium, 35 women with PCOS and gingivitis, 25 systemically and periodontally healthy women, 20 systemically healthy women with gingivitis. Salivary levels of seven putative periodontal pathogens were analyzed by quantitative real-time polymerase chain reaction and serum antibody levels were analyzed by ELISA. In women with PCOS, salivary Porphyromonas gingivalis, Fusobacterium nucleatum, Streptococcus oralis and Tannerella forsythia levels were higher than matched systemically healthy women, particularly in the case of gingivitis. Aggregatibacter actinomycetemcomitans and Treponema denticola levels were similar among study groups. The presence of PCOS also enhanced P. gingivalis, Prevotella intermedia and S. oralis serum antibody levels, when gingivitis was also present. Gingival inflammation correlated positively with levels of the studied taxa in saliva, particularly in PCOS. The presence of P. gingivalis and F. nucleatum in saliva also exhibited a strong positive correlation with the corresponding serum antibody levels. In conclusion, as an underlying systemic endocrine condition, PCOS may quantitatively affect the composition of oral microbiota and the raised systemic response to selective members of this microbial community, exerting a confounding role in resultant gingival inflammation and periodontal health. The most consistent effect appeared to be exerted on P. gingivalis.

Infective endocarditis associated with mitral valve prolapse in a patient with Klinefelter syndrome

We herein report a case of infective endocarditis associated with mitral valve prolapse (MVP) in a 34-year-old man with Klinefelter syndrome. The patient was admitted with a fever and headache that had persisted for three weeks. Repeated blood cultures showed growth of Streptococcus oralis. Echocardiography demonstrated severe mitral regurgitation with a large vegetation attached to the prolapsed anterior leaflet. Surgical plasty of the mitral valve was performed because the vegetation measured over 10 mm in diameter and there was a risk of recurrence of embolic complications. This case demonstrates the link between MVP and Klinefelter syndrome and highlights the importance of performing cardiovascular screening and preventing endocarditis.

Simultaneous detection of Streptococcus pneumoniae, S. mitis, and S. oralis by a novel multiplex PCR assay targeting the gyrB gene

A multiplex PCR (mPCR) protocol was developed for simultaneous detection of the gyrB gene in Streptococcus pneumoniae, Streptococcus mitis, and Streptococcus oralis, and the specificity was evaluated using 141 coccus strains. Genomic DNAs purified from S. pneumoniae, S. mitis, and S. oralis strains were efficiently detected with size differences, whereas no PCR products were amplified from any of the reference strains tested. A pilot study of 47 human oral swab specimens was conducted in parallel, and the mPCR assay identified S. pneumoniae in 1 sample, S. mitis in 8 samples, and S. oralis in 2 samples, providing a powerful means for characterization at the level of species compared with traditional culture analysis. Our results suggest that the mPCR protocol presented here is a sensitive and promising tool for the rapid detection and discrimination of S. pneumoniae, S. mitis, and S. oralis from clinical specimens.

An outbreak of streptococcus endophthalmitis after intravitreal injection of bevacizumab

PURPOSE

To report a series of patients with Streptococcus endophthalmitis after injection with intravitreal bevacizumab prepared by the same compounding pharmacy.

DESIGN

Noncomparative consecutive case series.

METHODS

Medical records and microbiology results of patients who presented with endophthalmitis after injection with intravitreal bevacizumab between July 5 and July 8, 2011, were reviewed.

RESULTS

Twelve patients were identified with endophthalmitis, presenting 1 to 6 days after receiving an intravitreal injection of bevacizumab. The injections occurred at 4 different locations in south Florida. All patients received bevacizumab prepared by the same compounding pharmacy. None of the infections originated at the Bascom Palmer Eye Institute, Miami, Florida, although 9 patients presented to its tertiary-care ophthalmic emergency room for treatment, and 3 additional patients were seen in consultation. All patients were treated initially with a vitreous tap and injection; 8 patients subsequently received a vitrectomy. Microbiology cultures for 10 patients were positive for Streptococcus mitis/oralis. Seven unused syringes of bevacizumab prepared by the compounding pharmacy at the same time as those prepared for the affected patients also were positive for S. mitis/oralis. After 4 months of follow-up, all but 1 patient had count fingers or worse visual acuity, and 3 required evisceration or enucleation. Local, state, and federal health department officials have been investigating the source of the contamination.

CONCLUSIONS

In this outbreak of endophthalmitis after intravitreal bevacizumab injection, Streptococcus mitis/oralis was cultured from the majority of patients and from all unused syringes. Visual outcomes were generally poor. The most likely cause of this outbreak was contamination during syringe preparation by the compounding pharmacy.

[Analysis of community composition in dental plaque of elder people with root caries]

OBJECTIVE

To analyze the community in dental plaque of elder people with root caries.

METHODS

Total DNAs were extracted from the root caries dental plaques of nine elders over 60 years of age. Polymerase chaid reaction-based denaturing gradient gel electrophoresis (PCR-DGGE) was used to analyze the microbial composition, DGGE bands were excised from the gels for sequencing and identification.

RESULTS

The dominant genus in root caries dental plaque of elder people were: Acinetobacte [0.9% (1/114)], Actinobaculum [1.8% (2/114)], Actinomyces [15.8% (18/114)], Aggregatibacter [0.9% (1/114)], Capnocytophaga [14.0% (16/114)], Corynebacterium [0.9% (1/114)], Haemophilus [0.9% (1/114)], Mobiluncus [0.9% (1/114)], Naxibacter [0.9% (1/114)], Neisseriaceae [10.5% (12/114)], Porphyromonas [0.9% (1/114)], Prevotella [12.3% (14/114)], Selenomonas [6.1% (7/114)], Staphylococcus [1.8% (2/114)], Oralis streptococcus [6.1% (7/114)], Mutans streptococcu [7.9% (9/114)], Tannerella [0.9% (1/114)], Treponema [1.8% (2/114)], Veillonella [10.5% (12/114)] and two uncultured unknown genus [1.8% (2/114)]. Uncultred genotypes accounted for 19.30% of the total. Gram-positive bacteria genotype accounted for 31.6% (36/114), and Gram-negative bacteria genotype accounted for 66.7% (76/114).

CONCLUSIONS

There were many bacteria genotypes in root caries dental plaque in the elderly, which were widely distributed. Gram-negative bacteria accounted for the majority. Genotype-specific pathogenic bacteria were not found.

A rare case of infective endocarditis complicated by Trichosporon asahii fungemia treated by surgery

The patient was a 58-year-old male. He consulted our hospital because of weight loss and fever. Computed tomography (CT) revealed renal infarction. Nine days after admission, CT showed hemorrhagic cerebral infarction in the right frontal lobe. A blood culture revealed streptococcus oralis, and echocardiography revealed vegetation in the mitral and aortic valves, suggesting infective endocarditis (IE). Fever (39 degrees C or higher) was noted 23 days after admission. A blood culture revealed Trichosporon asahii (T. asahii), suggesting T. asahii fungemia. An intravenous drip of fluconazole at 400 mg/day was initiated, and two-valve replacement was performed 34 days after admission. Following surgery, the patient became negative for beta-D glucan and was discharged 85 days after admission. We report the present case of IE complicated by T. asahii fungemia, which is rare in patients other than malignant blood disease or tumor patients, showing a poor prognosis in which survival was achieved by surgery.

Population structure of Streptococcus oralis

Streptococcus oralis is a member of the normal human oral microbiota, capable of opportunistic pathogenicity; like related oral streptococci, it exhibits appreciable phenotypic and genetic variation. A multilocus sequence typing (MLST) scheme for S. oralis was developed and the resultant data analysed to examine the population structure of the species. Analysis of 113 isolates, confirmed as belonging to the S. oralis/mitis group by 16S rRNA gene sequencing, characterized the population as highly diverse and undergoing inter- and intra-species recombination with a probable clonal complex structure. ClonalFrame analysis of these S. oralis isolates along with examples of Streptococcus pneumoniae, Streptococcus mitis and Streptococcus pseudopneumoniae grouped the named species into distinct, coherent populations and did not support the clustering of S. pseudopneumoniae with S. mitis as reported previously using distance-based methods. Analysis of the individual loci suggested that this discrepancy was due to the possible hybrid nature of S. pseudopneumoniae. The data are available on the public MLST website (http://pubmlst.org/soralis/).

[The analysis of the bacterial and fungal flora in maxillary sinuses in patients operated due to FESS method]

INTRODUCTION

The aim of this work was to analyse the bacterial and fungal flora in maxillary sinuses in patients operated due to the FESS method.

MATERIAL AND METHODS

Studies were conducted on 110 patients, including 47 women aged 17-78 and 63 men aged 17-66, who underwent endoscopic surgical procedures due to chronic polypoid maxillary sinusitis between 2006 and 2007. 214 cultures were prepared altogether. During the endoscopic operation on paranasal sinuses, a cannula was introduced along the natural entrance and material for the culture and antibiogram was removed by suction.

RESULTS

In the studied material of 214 cultures, 72 (33.6%) cultures obtained positive results, including 2 cases with bacterial and fungal floras present simultaneously (Aspergillus fumigatus and Aspergillus niger) in 38 operated patients. In 25 (34.5%) cultures we noted the presence of Staphylococcus epidermidis, which was sensitive to the following antibiotics: Cotrimoxazole, Rifampicin, Vankomycin, Teicoplanin and Levofloxacin. Staphylococcus epidermidis was isolated in 22 (31.0%) cultures, showing 100% sensitivity to similar antibiotics like the previous one. Another bacteria (Escherichia coli) was cultured in 10 cultures (13.8%), in 70% of the cases every second bacteria was Staphylococcus epidermidis with 100% sensitivity mainly to cephalosporins and aminoglycosides. In 3 cultures (4.17%) we found Klebsiella pneumoniae, with 100% sensitivity to cephalosporins and aminoglycosides and 100% resistance to penicillins. In three cases Pseudomonas fluorescens and Proteus mirabilis (4.17% each) were cultured with their sensitivity and resistance similar to those of Klebsiella pneumoniae. Two cases (2.8% each) in the cultures were noted: Citrobacter freundii, Streptococcus oralis and Hafnia alvei, which were 100% sensitive to some cephalosporins and aminoglycosides whereas their resistance to penicillins and Cefuroxime was as high as 100%.

CONCLUSION

In the operated patients suffering from chronic polypoid maxillary sinuses we found 33.6% of positive results in the bacterial flora. This indicates that the changes were accompanied by an acute inflammatory condition, thus surgical procedures had to be followed by a guided antibiotic. The cultured bacteria demonstrated sensitivity to some cephalosporins and aminoglycosides and resistance to penicillins, which proves the abuse of penicillins in the treatment of acute inflammatory states of upper airways.

Experimental infective endocarditis induced by human supragingival dental plaque in rats

Human dental plaque is thought to contribute to disease, not only in the oral cavity but also at other body sites. To investigate the pathogenicity of dental plaque in tissues remote from the mouth, we examined the ability of human supragingival dental plaque to induce infective endocarditis (IE) in rats. In total, 15 out of 27 catheterized rats survived after intravenous injections with human supragingival dental plaque suspensions containing 3 x 10(6) colony-forming units (CFU) of bacterial cells. In surviving rats, infected vegetations were formed in all except one rat. The microbial composition of the infected vegetations was different from that of the respective dental plaque inocula, with Streptococcus oralis comprising the majority of the isolates. In rats affected with endocarditis, the aortic sinus was filled with fibrinous vegetation containing bacteria. Inflammatory cells infiltrated the aortic valve, the aorta adjacent to the valve, and the cardiac muscles. The inoculation of catheterized rats with a cell suspension of S. oralis isolate (5 x 10(6) CFU) was not lethal but capable of inducing endocarditis in all animals. The results suggest that if dental plaque were introduced into the bloodstream, it could serve as a potent source of bacteria causing IE in humans.

Aortic Endograft Infection: Open Surgical Management with Endograft Preservation

INTRODUCTION

We report successful management of aortic endograft infection without graft explantation or extra-anatomic bypass.

REPORT

A 66 year-old male who had undergone endovascular repair of an aortic aneurysm presented with abdominal pain and raised inflammatory markers following embolisation of a type-2 'endoleak'. CT scanning revealed a left psoas fluid collection. Endograft infection was diagnosed. Following failure of CT-guided drainage and conservative management, surgical drainage with irrigation drain placement was undertaken with preservation of the endograft. There was no evidence of recurrent infection after follow-up at 30 months.

DISCUSSION

Aortic endograft infection may be managed without endograft removal and extra-anatomic bypass.

Identification of periodontopathic bacteria in gingival tissue of Japanese periodontitis patients

INTRODUCTION

The identification of invading periodontopathic bacteria in tissues is important to determine their role in the pathogenesis of periodontal disease. The objective of this study was to identify periodontopathic bacteria in diseased gingival tissue of periodontitis patients.

METHODS

Subgingival plaque and gingival tissue were collected from 32 generalized chronic periodontitis (CP), 16 generalized aggressive periodontitis (GAgP) and eight localized aggressive periodontitis (LAgP) patients. Detection frequencies and quantities of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Tannerella forsythensis were investigated by polymerase chain reaction. The prevalences of Streptococcus oralis and Streptococcus sobrinus were also examined and the distribution of A. actinomycetemcomitans serotypes was observed.

RESULTS

P. gingivalis and T. forsythensis were detected in approximately 70% of tissue samples and 50% of plaque samples in the three periodontitis groups. Prevalence of A. actinomycetemcomitans in tissue samples was higher in the LAgP (63%) group than in either the CP (16%) or the GAgP (38%) group. A. actinomycetemcomitans serotype c was detected in 50% of LAgP patients. Detection frequencies of S. oralis and S. sobrinus were markedly low in both plaque and tissue samples from all three periodontitis groups. Amounts of P. gingivalis, A. actinomycetemcomitans and T. forsythensis in the tissue samples were not different among the three periodontitis groups.

CONCLUSION

P. gingivalis, A. actinomycetemcomitans and T. forsythensis can localize in diseased gingival tissue and may be involved in periodontal tissue destruction. Serotype c is the predominant serotype of A. actinomycetemcomitans in Japanese LAgP patients.

Bacterial contamination of filtered intraoral bone chips

Intraoral bony defects can be filled with bony particles that are collected in a titanium filter. The aim of this study was to determine quantitatively and qualitatively the degree of this contamination. Over a period of 3 months, bony particles were collected from 50 patients undergoing oral surgery. The bony particles were scraped off the filter, resuspended, and incubated aerobically and anaerobically on human blood agar media. Colony forming units (CFU) were determined as well as the most common species of bacteria. All samples showed anaerobic and aerobic growth. After anaerobic incubation in 44 samples the number of bacteria was higher (38) or equal (six) to that after aerobic incubation. On average, 435,000 CFU (aerobic) and 1,013,000 CFU (anaerobic) per sample were found. The most frequently identified bacteria belonged to Veillonella spp. in the anaerobic and to Streptococcus oralis in the aerobic cultures. In 43 samples black-pigmented colonies were detected. Only bacteria common in the oral cavity were identified. Prophylactic antibiotic therapy may be indicated when using filtered bony particles for intraoral augmentation procedures.

Use of the housekeeping genes, gdh (zwf) and gki, in multilocus sequence typing to differentiate Streptococcus pneumoniae from Streptococcus mitis and Streptococcus oralis

Polymerase chain reaction and sequencing of the housekeeping genes, gdh (zwf) and gki, based on the primers and alleles from multilocus sequence typing can be used to delineate and support the identity of clinical isolates of Streptococcus pneumoniae and differentiate from the closely related Streptococcus mitis and Streptococcus oralis.

Comparison of bacterial plaque samples from titanium implant and tooth surfaces by different methods

Studies have shown similarities in the microflora between titanium implants or tooth sites when samples are taken by gingival crevicular fluid (GCF) sampling methods. The purpose of the present study was to study the microflora from curette and GCF samples using the checkerboard DNA-DNA hybridization method to assess the microflora of patients who had at least one oral osseo-integrated implant and who were otherwise dentate. Plaque samples were taken from tooth/implant surfaces and from sulcular gingival surfaces with curettes, and from gingival fluid using filter papers. A total of 28 subjects (11 females) were enrolled in the study. The mean age of the subjects was 64.1 years (SD+/-4.7). On average, the implants studied had been in function for 3.7 years (SD+/-2.9). The proportion of Streptococcus oralis (P<0.02) and Fusobacterium periodonticum (P<0.02) was significantly higher at tooth sites (curette samples). The GCF samples yielded higher proportions for 28/40 species studies (P-values varying between 0.05 and 0.001). The proportions of Tannerella forsythia (T. forsythensis), and Treponema denticola were both higher in GCF samples (P<0.02 and P<0.05, respectively) than in curette samples (implant sites). The microbial composition in gingival fluid from samples taken at implant sites differed partly from that of curette samples taken from implant surfaces or from sulcular soft tissues, providing higher counts for most bacteria studied at implant surfaces, but with the exception of Porphyromonas gingivalis. A combination of GCF and curette sampling methods might be the most representative sample method.

Is pre-term labour associated with periodontitis in a Danish maternity ward?

OBJECTIVES

To reveal differences in periodontal status and presence of subgingival bacteria in a Scandinavian population of women with pre-term birth compared with women who delivered at term.

MATERIALS AND METHODS

Twenty-one women with pre-term labour (before week 35) and 33 women with term labour (between weeks 38 and 41) were included in this case-control study. Periodontal measurements included plaque index (PlI), probing pocket depth (PPD) and bleeding on probing (BOP). Inter-proximal distances from the cemento-enamel junction (CEJ) to the marginal bone crest (MBC) were measured on bitewing radiographs. In 31 patients (16 cases and 15 controls) the subgingival plaque was analysed using "checkerboard" DNA-DNA hybridization.

RESULTS

Differences between the two examined groups were found related to "Twin births" (p=0.0064) and "Smokers" (p=0.03). None of the periodontal measurements showed any association. Significant differences were found concerning presence of Tannerella forsythensis, Treponema denticola, Peptostreptococcus micros, Streptococcus intermedius, Streptococcus oralis, Streptococcus sanguis and Capnocytophaga ochracea but when defining sites with >10(5) bacteria as heavily colonized, no statistical difference was found between the two groups.

CONCLUSION

A relation between pre-term birth and periodontitis was not revealed in the present study.

Mercuric resistance genes in gram-positive oral bacteria

Mercury-resistant bacteria isolated from the oral cavities of children carried one of two types of merA gene that appear to have evolved from a common ancestor. Streptococcus oralis, Streptococcus mitis and a few other species had merA genes that were very similar to merA of Bacillus cereus strain RC607. Unlike the B. cereus RC607 merA gene, however, the streptococcal merA genes were not carried on Tn5084-like transposons. Instead, comparisons with microbial genomic sequences suggest the merA gene is located on a novel type II transposon. Coagulase-negative staphylococci and Streptococcus parasanguis had identical merA genes that represent a new merA variant.

PCR detection and identification of oral streptococci in saliva samples using GTF genes

Oral streptococci are major constituents of dental plaque, and their prevalence is implicated in various pathologies. Therefore, accurate identification of oral streptococci would be valuable for studies of cariogenic plaque and for diagnostic use in infective endocarditis. Many oral streptococci possess glucosyltransferase enzymes that synthesize glucan, which is an obligate component of dental plaque. We established a rapid and precise method to identify oral streptococci by PCR using the species-specific region from the glucosyltransferase gene. With the species-specific primers, Streptococcus mutans, S. sobrinus, S. salivarius, S. sanguinis, S. oralis, and S. gordonii could be successfully distinguished. Further, we developed a simple method to extract the bacterial DNA from saliva. Using the resultant DNA as a template, the proposed PCR detection was performed. Their distribution was in accord with results of conventional biochemical tests. These findings indicate that the present PCR method is useful for the analysis of oral streptococci and can be successfully used in clinical applications to identify pathogenic bacteria associated with oral infectious disease and/or endocarditis.

Effect of acidic pH on expression of surface-associated proteins of Streptococcus oralis

Streptococcus oralis, a member of the mitis group of oral streptococci, is implicated in the pathogenesis of infective endocarditis and is the predominant aciduric non-mutans-group streptococcus in dental plaque. We undertook to identify the most abundant surface-associated proteins of S. oralis and to investigate changes in protein expression when the organism was grown under acidic culture conditions. Surface-associated proteins were extracted from cells grown in batch culture, separated by two-dimensional gel electrophoresis, excised, digested with trypsin, and analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry and liquid chromatography-tandem mass spectrometry. Putative functions were assigned by homology to a translated genomic database of Streptococcus pneumoniae. A total of 27 proteins were identified; these included a lipoprotein, a ribosome recycling factor, and the glycolytic enzymes phosphoglycerate kinase, fructose bisphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, and enolase. The most abundant protein, phosphocarrier protein HPr, was present as three isoforms. Neither lactate dehydrogenase nor pyruvate oxidase, dominant intracellular proteins, were present among the proteins on the gels, demonstrating that proteins in the surface-associated pool did not arise as a result of cell lysis. Eleven of the proteins identified were differentially expressed when cells were grown at pH 5.2 versus pH 7.0, and these included superoxide dismutase, a homologue of dipeptidase V from Lactococcus lactis, and the protein translation elongation factors G, Tu, and Ts. This study has extended the range of streptococcal proteins known to be expressed at the cell surface. Further investigations are required to ascertain their functions at this extracellular location and determine how their expression is influenced by other environmental conditions.

[Chronic recurrent multifocal osteomyelitis of the mandible. A case report]

Chronic recurrent multifocal osteomyelitis (CRMO) is a disorder rarely localized to the lower jaw.

CASE REPORT

A fourteen-year-old boy complained of a swollen of his lower jaw. After a CT Scan, a bone biopsy was performed and yielded S. oralis against which an adapted intravenous antibiotherapy was administered without efficacy. The absence of malignant process and the revelation of an other focus of fixation at the Tc bone scan localized on humerus called to mind the diagnosis of CRMO.

CONCLUSION

The diagnosis of this disease is difficult and based on a number of concording arguments:clinical and radiological signs of osteomyelitis, multifocal presentation, recurrent relapses and remissions, inaction of antibiotics, elimination of the other differential diagnosis, in particular the infectious osteitis.

Varidans streptococci in the oral flora of the patients at risk for infective endocarditis: species and penicillin susceptibilities

This study examined viridans streptococci (SV) in oral flora of patients at risk of infective endocarditis (IE) by obtaining 57 isolates from gum-tooth margin swabs of 3 groups of patients. Penicillin minimal inhibitory concentrations (MICs) were determined by E test. Group 1 was from 30 patients with prosthetic heart valves who did not receive antimicrobial agents within 3 months prior to recruitment. Group 2 consisted of 21 patients with known rheumatic heart diseases who regularly received penicillin prophylaxis. Group 3 was 2 patients with IE caused by SV in whom dental swabs were performed before and on the third day of treatment. Streptococcus mitis was found most frequently (49% among 51 oral isolates of SV from patients in group 1 and 2) and in both blood cultures of IE patients. Ninety-four per cent of the isolates were penicillin-susceptible and the rest were intermediate-resistant (IR) equally distributed in both groups 1 and 2. In 2 patients with IE, oral SV obtained after 3 days of penicillin therapy had MICs rising 3 and 5 folds of the baselines. It is suggested that surveillance of susceptibilities of oral SV in patients at risk for IE should be kept up since this will affect the dose and type of antimicrobial agents in IE prophylaxis.

The effects of surface roughness and type of denture acrylic on biofilm formation by Streptococcus oralis in a constant depth film fermentor

AIMS

To investigate the effects of surface roughness and type of denture acrylic on the early development of a Streptococcus oralis biofilm in a constant depth film fermentor (CDFF).

METHODS AND RESULTS

Streptococcus oralis was incubated with acrylic of known surface roughness in the CDFF. Adherent Strep. oralis were enumerated by viable counting. Cold-cure acrylic was rougher (P < 0.01) than heat-cure acrylic after polishing with abrasive paper of any given grit-grade. Heat-cure acrylic was colonized by fewer (P < 0.001) bacteria than cold-cure acrylic at any given surface roughness. The number of bacteria adhering to heat-cure and cold-cure acrylic increased linearly with mean surface roughness after 2 h incubation, the increase being greater (P < 0.001) for the cold-cure compared with the heat-cure acrylic. However, after 4 h incubation, surface roughness appeared to have no effect on the number of adherent bacteria.

CONCLUSION

The type of acrylic used, and its roughness, affect the early stages of biofilm formation by Strep. oralis.

SIGNIFICANCE AND IMPACT OF THE STUDY

Choosing an appropriate type of smooth acrylic could lead to reduced biofilm formation in vivo.

Investigation of bacteremia after orthodontic banding and debanding following chlorhexidine mouth wash application

This study investigates the prevalence of bacteremia after orthodontic banding and debanding, following the application of a 0.2% chlorhexidine gluconate mouthwash. The banding and debanding groups were each composed of 40 young adult patients. In the banding group, patients were asked to rinse their mouth with chlorhexidine gluconate for 60 seconds just prior to fitting of the bands. In the debanding group, they were asked to use the mouthwash immediately before removal of bands and brackets. In both groups pre- and post-treatment blood samples were obtained with a strict aseptic technique. In the banding group, no bacteremia was detected in the pretreatment sample and 2.5% post-treatment bacteremia was detected in the post-treatment sample. In the debanding group, 2.5% bacteremia was found in both the pre- and post-treatment samples. The prevalence of post-treatment bacteremia found in the present study were compared with the findings of 2 preliminary studies in which the prevalence of bacteremia had been investigated after banding and debanding without a prior application of chlorhexidine mouthwash. The application of chlorhexidine mouthwash resulted in a decrease in the prevalence of bacteremia after banding and debanding, but the decrease was not statistically significant.

Automated immunofluorescence for enumeration of selected taxa in supragingival dental plaque

The present study investigated a recently developed automated image analysis technique for its applicability to the enumeration of selected bacteria in supragingival dental plaque. Following initial calibration, the system is capable to count fluorescence-labeled target cells in up to 48 samples without user interference. Test samples contained a characteristic mixture of planktonic bacteria, small almost planar bacterial aggregates, and large, virtually indisruptable clumps with cells from multiple species. Due to their complex composition, these samples provided a challenging validation step for the image analysis system. Automated enumeration of target bacteria was compared with visual counting of the fluorescence-labeled bacteria. Results are shown for six taxa (Actinomyces naeslundii, Fusobacterium nucleatum, Prevotella intermedia/Prev. nigrescens, Streptococcus gordonii/Strep. oralis/Strep. sanguis, Strep. sobrinus, and Veillonella dispar/ V. parvula) with characteristic differences in abundance, cell morphology and aggregation behavior. Results revealed good correspondence between the two enumeration techniques (correlation coefficients ranging from 0.77 to 0.92) provided that the portion of target bacteria exceeded 0.05% of the total bacterial cell number. This work demonstrates the applicability and usefulness of fully automated immunofluorescence to analyze such complex ecosystems as supragingival dental plaque.

Genotypic heterogeneity of Streptococcus oralis and distinct aciduric subpopulations in human dental plaque

The genotypic heterogeneity of Streptococcus oralis isolated from the oral cavity was investigated using repetitive extragenic palindromic PCR. Unrelated subjects harbored unique genotypes, with numerous genotypes being isolated from an individual. S. oralis is the predominant aciduric bacterium isolated from noncarious tooth sites. Genotypic comparison of the aciduric populations isolated at pH 5.2 with those isolated from mitis-salivarius agar (MSA) (pH 7.0) indicated that the aciduric populations were genotypically distinct in the majority of subjects (chi(2) = 13.09; P = 0.0031). Neither the aciduric nor the MSA-isolated strains were stable, with no strains isolated at baseline being isolated 4 or 12 weeks later in the majority of subjects. The basis of this instability is unknown but is similar to that reported for Streptococcus mitis. Examination of S. oralis strains isolated from cohabiting couples demonstrated that in three of five couples, genotypically identical strains were isolated from both partners and this was confirmed by using Salmonella enteritidis repetitive element PCR and enterobacterial PCR typing. These data provide further evidence of the physiological and genotypic heterogeneity of non-mutans streptococci. The demonstration of distinct aciduric populations of S. oralis implies that the role of these and other non-mutans streptococci in the caries process requires reevaluation.

Origins of Staphylococcus epidermidis and Streptococcus oralis causing bacteraemia in a bone marrow transplant patient

Coagulase-negative staphylococcal bacteraemia in immunocompromised patients is often associated with the use of central venous catheters, while the proposed origin of viridans streptococci causing bacteraemia in this patient group is the oral cavity. This report describes an episode of polymicrobial bacteraemia caused by Staphylococcus epidermidis and Streptococcus oralis followed by several further episodes of S. epidermidis bacteraemia in a 15-year-old boy after bone marrow transplantation. Pulsed-field gel electrophoresis (PFGE) of SmaI chromosomal DNA digests was used to compare blood culture and oral isolates of S. epidermidis and Str. oralis. The results indicated that the mouth was the source of both S. epidermidis and Str. oralis causing the first episode of bacteraemia. PFGE further demonstrated that the central venous catheter was the origin of a second strain of S. epidermidis responsible for subsequent episodes of staphylococcal bacteraemia. Both the oral mucosa and central venous lines should be considered as potential sources of organisms, including coagulase-negative staphylococci, associated with bacteraemia in immunocompromised patients.

Lack of association between Streptococcus oralis and recurrent aphthous stomatitis

In the present study, the potential involvement of Streptococcus oralis in the aetiology of recurrent aphthous stomatitis (RAS) was investigated using the polymerase chain reaction (PCR). Biopsies from 28 RAS patients were analysed, in addition to 20 oral lichen planus (OLP) and 13 normal biopsies that were used as controls. PCR was carried out using a primer pair that targets the D-alanine:D-alanine ligase gene and detects DNA from both S. oralis and the closely related species Streptococcus mitis. Discrimination between these two species was achieved by digestion of PCR products with the restriction endonucleases HaeIII and HindIII, which both give distinct restriction profiles for each species. S. oralis DNA was detected in 8 of 28 (29%) RAS samples, 10 of 20 (50%) OLP samples and 6 of 13 (46%) normal samples. These results suggest that S. oralis is not of primary aetiological significance in RAS.

Molecular relationships and antimicrobial susceptibilities of viridans group streptococci isolated from blood of neutropenic cancer patients

From January 1995 to May 1998, 57 episodes of bacteremia due to viridans group streptococci were identified in 50 febrile neutropenic patients with hematologic malignancies. Four patients experienced two separate episodes of streptococcal bacteremia, and one patient had four separate episodes of streptococcal bacteremia. Strains were identified to species level as Streptococcus mitis (n = 37), Streptococcus oralis (n = 19), and Streptococcus salivarius (n = 1). Epidemiologic relatedness of these strains was studied by using PCR-based fingerprinting with M13 and ERIC-2 primers and pulsed-field gel electrophoresis with restriction enzyme SmaI. All strains that were isolated from different patients exhibited unique fingerprint patterns, thus suggesting that viridans group streptococcal bacteremia usually derives from an endogenous source. Cross-transmission of strains between patients could not be established. Four S. mitis isolates recovered during four separate bacteremic episodes in a single patient had identical fingerprint patterns. Susceptibility testing was carried out by broth microdilution technique according to National Committee for Clinical Laboratory Standards guidelines. The MICs at which 90% of the isolates are inhibited were (in milligrams per liter) as follows: 0. 5 (penicillin), 0.5 (amoxicillin), 0.25 (cefotaxime), 2 (chloramphenicol), 4 (erythromycin), 0.5 (clindamycin), >/=32 (tetracycline), >/=32 (trimethoprim-sulfamethoxazole), 4 (ciprofloxacin), 0.5 (sparfloxacin), 0.5 (vancomycin), 0.25 (teicoplanin), and 1 (quinupristin-dalfopristin). High-level penicillin resistance (MIC, >/=4 mg/liter) was found in one isolate only, but intermediate penicillin resistance was noted in 11 isolates (19%). Resistance rates to other drugs were as follows: 7% (amoxicillin), 4% (cefotaxime), 4% (chloramphenicol), 32% (erythromycin), 9% (clindamycin), 39% (tetracycline), 68% (trimethoprim-sulfamethoxazole), 23% (ciprofloxacin), 0% (sparfloxacin), 0% (vancomycin), 0% (teicoplanin), and 0% (quinupristin-dalfopristin).

[2 cases of iatrogenic oral streptococcal infection: meningitis and spondylodiscitis]

INTRODUCTION

The multiplication of invasive spine investigations for either diagnostic or therapeutical purposes increases the risk for iatrogenic infections. We report two cases of iatrogenic infections, one case of meningitidis and one case of spondylodiscitis due to Streptococcus viridans.

EXEGESIS

The two cases included a 42-year-old male patient presenting with spondylodiscitis due to Streptococcus oralis following nucleolysis for discal node and a 51-year-old female patient with purulent meningitidis due to Streptococcus salivarius following hysteroscopy with spinal anesthesia. According to the disease chronology and bacterial results, iatrogenesis was evidenced. The streptococci originate from the patient's skin or from the operators' endobuccal flora.

CONCLUSION

Simple aseptic rules, including wearing a surgical mask during any spinal tap, would definitely avoid iatrogenic infections.

Subgingival microbiota in healthy, well-maintained elder and periodontitis subjects

This investigation compared the site prevalence of 40 subgingival species in 30 periodontally healthy (mean age 36+/-9 years), 35 elders with a well-maintained periodontium (mean age 77+/-5) and 138 adult periodontitis subjects (mean age 46+/-11). Subgingival plaque samples were taken from the mesial aspect of each tooth (up to 28 samples) in the 203 subjects at baseline. The presence and levels of 40 subgingival taxa were determined in 5003 plaque samples using whole genomic DNA probes and checkerboard DNA-DNA hybridization. Clinical assessments including dichotomous measures of gingival redness, bleeding on probing, plaque accumulation and suppuration, as well as duplicate measures of pocket depth and attachment level, were made at 6 sites per tooth. The % of sites colonized by each species (prevalence) was computed for each subject. Differences in prevalence and levels among groups were sought using the Kruskal-Wallis test. Commonly detected species, such as Actinomyces naeslundii genospecies 2, Streptococcus sanguis and Streptococcus oralis did not differ significantly among subject groups. After adjusting for multiple comparisons, 4 species were significantly elevated and at greater prevalence in the periodontitis group. Mean % of sites (+/-SEM) colonized by Bacteroides forsythus was 10+/-3, 12+/-2 and 40+/-2 (p<0.001) for healthy, elder and periodontitis groups respectively. The odds ratio was 14.4:1 that a subject had periodontitis when B. forsythus was detected at > or = 5% of sampled sites. Mean prevalence for Porphyromonas gingivalis in healthy, elder and periodontitis subjects was 4+/-2, 5+/-2 and 23+/-2 respectively (p<0.001); for Treponema denticola 12+/-4, 10+/-3 and 30+/-2 (p<0.001) and for Selenomonas noxia 6+/-2, 7+/-2 and 19+/-2 (p<0.01). Similar differences among subject groups were observed when only sites with PD 0-4 mm were analyzed. The data suggest an etiologic role for B. forsythus, P. gingivalis, T. denticola and S. noxia in adult periodontitis.

[A new genus of oral bacteria in human]

A strain, No. 90-1, is isolated from the oral cavity of a patient with periodontophthy. This strain is a Gram-positive, non-endospore-forming, facultative anaerobe with spherical cells, 0.9-1.5 microns in diameter, occuring in pairs and seldom in short chains of four cells, and motile by one flagellum per cell. The optimum growing temperature is 35-37 degrees C; appreciable growth is not found below 10 degrees C, but growth at 53 degrees and tolerance to 60 degrees C for 30 min. This strain is microhalophilous and grows best, well and poorly in the medium containing 2%, 10%-15% and 25% NaCl respectively. Catalase and urease are positive and nitrate is reduced. Acid is produced from many carbohydrates, but no gas. Gelatin can be hydrolyzed, but starch, cellulose and dextrin do not. G + C content in DNA is 41.34 mol%(Tm). The strain(90-1) is considered to be a new species belonging to a new genus because its some characteristics are different from those of the known coccus genuera and designated as Stomatostreptococcus microhalophilus Ping, Zhou, Sun et Fan gen. nov. sp. nov. according to its source and microhalophilic trait.

Comparison of the indigenous oral microbiota and immunoglobulin responses of athymic (nu/nu) and euthymic (nu/+) mice

The role of the immune system in the homeostasis of indigenous oral bacterial populations is poorly understood. In this study, we compared the evolution of the indigenous oral microbiota of specific pathogen-free athymic nude (nu/nu) BALB/c mice with that of their corresponding phenotypically normal (nu/-) littermates. We also evaluated corresponding salivary and serum antibody activities (IgA and IgG) against the predominant indigenous oral bacteria. The bacterial species recovered from the two mouse strains were Lactobacillus murinus, Enterococcus faecalis, Streptococcus oralis and Staphylococcus epidermidis. From 27 days of age, nu/+ and nu/nu mice had significantly different proportions of oral bacterial populations. When the microbiota stabilized (at 40 days of age), the total cultivable microbiota of nu/+ mice was dominated by L. murinus (65-85%), while that of nu/nu mice was dominated by E. faecalis (40-60%). The precise factors that alter the oral resident microbiota in nu/nu mice are unknown. We found that total salivary IgA levels were significantly lower in nu/nu mice, but no association were observed between the level of salivary IgA antibody against indigenous bacteria and the proportion of these indigenous bacteria in the oral microbiota. The change in the microbiota of nude mice may have been caused by other factors such as defects in other immune functions or cold stress.

Bacterial adherence to the surface and isolated cell epithelium of the palatine tonsils

Bacterial adherence to the oropharyngeal epithelium is a significant factor in normal microecology, etiopathogenesis of diseases (tonsillitis, gingivitis) and possibly also induction of immune response. Bacterial adhesion to human tonsillar epithelium of whole tonsils and swabs was studied by fluorescence, scanning, and transmission electron microscopy. The epithelial cell borders were well demarcated. On the apical surface of the cells there were irregular microridges. All forms of microscopy visualized epithelial cells with attached bacteria, often forming microcolonies on the free surface. Some bacteria formed excavations on the cell surface. Most attached bacteria were coccoid, but variously sized rods were also visible. In transmission electron microscopy, epithelial cells with intracellular bacteria were regularly observed.