Recovery and clearance rates of oral microorganisms following experimental bacteraemias in dogs

Exodontia associated bacteremia in horses characterized by next generation sequencing

Bacteremia resulting from dental surgery is increasingly recognized as a health risk, especially in older and immunocompromised patients. Dentistry-associated bacteremia can lead to remote infections, as exemplified by valvular endocarditis. Emerging evidence points to a novel role played by oral cavity commensals in the pathogenesis of diabetes, respiratory disease, cardiovascular disease, and adverse pregnancy outcomes. Whether dental extraction, a commonly undertaken procedure in old horses, causes bacteremia has not been reported extensively. In a prospective clinical study using next generation sequencing (based on bacterial 16S rRNA), the circulating blood microbiome was characterized before and at 1 h following extraction of incisor, canine or cheek teeth from 29 adult horses with dental disease. 16S rRNA gene sequencing results from the blood microbiome were compared with those from gingival swab samples obtained prior to extraction at the location of the diseased tooth. Bacteremia associated with translocated gingival commensals was demonstrated in horses undergoing exodontia and was, in some cases, still evident one hour post-operatively.

Evaluation of Subgingival Bacteria in the Dog and Susceptibility to Commonly Used Antibiotics

The aim of the present investigation was to evaluate the subgingival aerobic and anaerobic flora of 13 dogs with periodontal disease and the susceptibility of these bacteria to antibiotics currently approved in Italy for treatment of canine infections. Of the anaerobic bacteria, Bacteroides fragilis was most frequently isolated, followed by Peptostreptococcus + Porphyromonas gingivalis and Prevotella intermedia. Of the aerobic bacteria, α-hemolytic Streptococcus was most frequently isolated, often associated with Escherichia coli or Pasteurella multocida. Resistance of anaerobic and aerobic bacteria to various antibiotics was generally high. Anaerobic bacteria appeared to be susceptible to amoxicillin + clavulanic acid, doxycycline, and erythromycin; aerobic bacteria appeared to be susceptible to amoxicillin + clavulanic acid, erythromycin, gentamycin, and sulfa-trimethoprim. Bacteroides fragilis was resistant to all of the antibiotics tested. The emerging worldwide problem of bacterial resistance to antibiotics resulting from overuse and misuse of antibiotics is discussed.

Bacteraemia before, during and after tooth extraction in horses in the absence of antimicrobial administration

BACKGROUND

Transient bacteraemia can occur during tooth extraction in humans, and dogs and can lead to severe infectious sequelae. Several case reports describe distant site infections following equine tooth extraction, but the occurrence of bacteraemia during dental surgery has not been evaluated in the horse.

OBJECTIVES

To determine if transient bacteraemia occurs during tooth extraction in horses, describe isolated organisms and compare these with those found in the diseased teeth.

STUDY DESIGN

Prospective, observational study.

METHODS

Blood was collected aseptically for blood culture before, during and after oral extraction of incisor, canine or cheek teeth from 20 adult horses undergoing dental extraction that had not received antimicrobial agents for at least 4 weeks prior to surgery. Bacteria found in blood cultures were compared with those found in swab samples obtained from the extracted teeth.

RESULTS

Eighteen of 20 horses had positive blood cultures at one or more time points. Streptococcus spp., Actinomyces spp., Fusobacterium spp. and Prevotella spp. were most commonly found. Bacterial genera isolated from swab samples of extracted teeth largely corresponded with those identified in blood cultures.

MAIN LIMITATIONS

This study was limited by its use of only conventional bacterial culture, the lack of statistical analysis to explore associations between gingiva score and the occurrence of bacteraemia, and the lack of an age-matched control group of horses not undergoing exodontia.

CONCLUSIONS

Transient bacteraemia of oral origin commonly occurs during dental extraction in horses. As none of the horses developed complications associated with bacteraemia during the observation period after surgery, the significance of this bacteraemia remains uncertain. The Summary is available in Chinese - see Supporting Information.

Bacteremia following scaling and root planing: A clinico-microbiological study

BACKGROUND

Bacteremia frequently occurs after treatment procedures such as extractions, scaling, root planing, periodontal surgery. There is currently significant interest in the possibility that bacteremia with oral bacteria may play role in pathogenesis of atherosclerosis. There are well-conducted studies that have determined the frequency of passage of periodontal microorganisms to the bloodstream after periodontal treatment. There is scarce information related to the incidence of periodontopathic microorganisms during bacteremia induced by this procedure.

AIM

The aim of this study was to establish the frequency of passage of periodontopathic microorganisms in peripheric blood after scaling and root planing in patients with periodontitis.

MATERIALS AND METHODS

Forty subjects with chronic periodontitis were included in the study. Blood samples were drawn from each patient at following intervals pre-treatment i.e., before SRP (P1), immediately after SRP (P2), and 30 minutes after SRP (P3). Following SRP, blood samples were analyzed for following microorganisms: Porphyromonasgingivalis, Tannerella. forysthus, Eikenellanella. corrodens, Campylobacter species, Micromonas. micros, and Prevotella. intermedia.

STATISTICAL ANALYSIS USED

Chi-square test.

RESULTS

Bacteremia was found in 70% (28/40) immediately after SRP and after 30 min, it was reduced to 25% (10/40) and 7.5% (3/40) presented bacteremia before SRP.

CONCLUSIONS

It was concluded that bacteremia frequently occurs immediately after SRP with P. gingivalis showing the highest frequency in blood.

Effect of the Diode Laser on Bacteremia Associated with Dental Ultrasonic Scaling: A Clinical and Microbiological Study

OBJECTIVE

The purpose of this study is to evaluate the potential use of diode lasers (DLs) to reduce bacteremia associated with ultrasonic scaling (US). Furthermore, the clinical efficacy of DLs as an adjunct to US in the treatment of gingivitis was investigated.

BACKGROUND DATA

Recently, lasers have found new applications in dental practice. The benefits of the use of DLs as an adjunct to US have not yet been determined.

METHODS

Twenty-two gingivitis patients were treated using a split-mouth study design in which each side was randomly treated by US alone or DL followed by US (DL + US). Blood samples were drawn just before and during US in each treatment step to detect induced bacteremia. Clinical parameters including plaque index, sulcus bleeding index, probing depth, and relative attachment level were recorded at baseline and 4 weeks postoperatively.

RESULTS

Bacteremia was detected in 15 patients (68%) after US alone, and in 8 patients following DL + US (36%). The reduction of the incidence of odontogenic bacteremia during US after the application of DL was statistically significant (p < 0.05). Clinical signs improved eventually, with no significant differences between the two treatment regimens (p > 0.05).

CONCLUSIONS

Application of DL energy can reduce bacteria in gingival crevices which may reduce bacteremia following US. The use of DL did not show additional clinical influence on gingival healing after treatment of gingivitis with US.

Chewing fails to induce oral bacteraemia in patients with periodontal disease

AIM

To investigate whether chewing in patients with untreated chronic periodontitis or plaque-induced gingivitis causes bacteraemia of oral origin.

METHOD

Twenty-one patients with untreated chronic periodontitis (32-75 years old) and 20 with plaque-induced gingivitis (26-54 years old) chewed a standard wax medium for 4 min. Blood samples were drawn before, during and 5 min. post-chewing. Aerobic and anaerobic Bactec system culturing was performed for 21 days and positive bottles were subcultured and isolates were identified to genus level. A full periodontal analysis was performed on all teeth and included probing depths, recession, attachment levels, bleeding on probing, mobility plaque index and gingival index. Radiographs were assessed for the severity of alveolar bone loss.

RESULTS

No bacteraemia of oral origin was detected in any patient. Skin contaminants (Staphylococcus epidermidis, Propionibacterium spp.) were detected in blood samples from three patients (two periodontitis; one gingivitis).

CONCLUSION

Chewing did not cause bacteraemia in chronic periodontitis or plaque-induced gingivitis patients and may not be a risk factor for infective endocarditis in at-risk individuals with periodontal disease.

Management of periodontal disease: understanding the options

Periodontal disease is the most common disease occurring in domestic dogs and cats, and local severity and the impact on the rest of the body are reasons why all companion animal patients should receive an oral examination every time they are seen. This article provides the background information on how an effective periodontal management program can be tailored for each patient.

Correlation between detection rates of periodontopathic bacterial DNA in coronary stenotic artery plaque [corrected] and in dental plaque samples

Utilizing PCR, the 16S rRNA detection rates for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Treponema denticola, and Campylobacter rectus in samples of stenotic coronary artery plaques were determined to be 21.6, 23.3, 5.9, 23.5, and 15.7%, respectively. The detection rates for P. gingivalis and C. rectus correlated with their presence in subgingival plaque.

The Short-Term Effects of Treatment of Chronic Periodontitis on Circulating Levels of Endotoxin, C-Reactive Protein, Tumor Necrosis Factor-α, and Interleukin-6

BACKGROUND

The acute-phase response involves molecules including tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and C-reactive protein (CRP). This study aimed to determine whether subgingival scaling resulted in rapid changes in plasma concentrations of these molecules.

METHODS

Twenty-three non-smoking adults with chronic periodontitis received subgingival scaling for 60 minutes. Venous blood samples were taken at 0, 15, 30, 60, and 120 minutes. TNF-alpha and IL-6 were assayed from all samples and CRP from the baseline and final samples. Lipopolysaccharide (LPS) was assayed at 0, 15, and 30 minutes using limulus lysate assay (LAL) and EndoCAb Ig assays.

RESULTS

LPS assays were suggestive of a transient low-grade bacteremia, but changes in LPS approaching significance (P=0.061) were seen with LAL only. There was a significant increase in circulating TNF-alpha (P=0.0387) and IL-6 (P<0.0001), and the degree of change in TNF-alpha was correlated with the severity of periodontal breakdown (P=0.001). There was also a significant correlation between levels of IL-6 and TNF-alpha (P<0.001).

CONCLUSIONS

Chronic periodontitis patients undergoing an episode of subgingival scaling show a significant elevation in circulating TNF-alpha and IL-6. This may account for anecdotal reports of pyrexia following treatment and may be significant in terms of the relationship between periodontal disease, bacteremia, and cardiovascular disease.

Intravenous antibiotic regimens and prophylaxis of odontogenic bacteraemia

OBJECTIVES

This study retrospectively examines the efficacy of prophylactic intravenous antibiotic regimens in the prevention of odontogenic bacteraemia in children with severe congenital heart defects receiving comprehensive dental treatment under general anaesthesia.

PATIENTS AND METHODS

Blood cultures were taken from children with congenital cardiac defects 30 seconds after completion of dental treatment under general anaesthesia. Antibiotic prophylaxis had been given intravenously immediately before dental treatment. The choice of antibiotics and the extent of dental treatment were recorded. The percentage prevalence of bacteraemia was compared with published data following multiple dental extractions using the same clinical and microbiological methodology.

RESULTS

The overall percentage prevalence of positive cultures in children receiving intravenous prophylactic antibiotics was 16%. The percentage of positive blood cultures in cardiac children who received ampicillin alone was not significantly different from that in children having a combination of amikacin and teicoplanin (16.7% v 22.2%) respectively [Chi Square = 0.385, df = 1, P= 0.535]. When compared with multiple extractions, both ampicillin alone and amikacin with teicoplanin were effective in reducing the prevalence of odontogenic bacteraemia.

CONCLUSIONS

In children with cardiac defects, bacteraemia after dental treatment is reduced by antibiotics but is still detected on 16% of occasions. In comparison with children receiving ampicillin alone, the combination of amikacin and teicoplanin is as effective in reducing bacteraemia in children who are either allergic to penicillins or who have received them within the previous month.

Bacteremia due to periodontal probing: a clinical and microbiological investigation

BACKGROUND

Infective endocarditis can occur in susceptible individuals due to bacteremia of oral origin. The aim of this study was to investigate the occurrence of bacteremia caused by full mouth periodontal probing.

METHODS

Forty patients, 20 with adult periodontitis (10 males, 10 females; mean age 43.0 years) and 20 with chronic gingivitis (11 males, 9 females; mean age 35.5 years) were investigated. Prior to and immediately following periodontal probing, 20 mL of venous blood were obtained from each patient and inoculated into aerobic and anaerobic blood culture bottles and incubated. Negative bottles were monitored continuously for 3 weeks before being discarded. Bottles which signalled positive were subcultured and isolates identified to genus level. Periodontal probing consisted of measuring pockets at 6 points around each tooth and recording the presence or absence of bleeding. A plaque index (PI) was assessed on the 6 Ramfjord teeth.

RESULTS

Probing caused bacteremia of oral origin in 8 (40%) of the periodontitis patients and 2 (10%) of the gingivitis patients. Streptococcus spp. were the most common isolates in both groups. Compared with the gingivitis group the odds ratio (OR) for bacteremia in the periodontitis group was 5.993 (95% CI 1.081 to 33.215). Bleeding on probing (OR 1.025, 95% CI 1.004 to 1.047) and mean probing depth per tooth (OR 1.444, 95% CI 1.055 to 1.977) were significantly associated with bacteremia. No significant correlations were found between bacteremia and age, number of teeth probed, smoking status, PI, or total probing depth.

CONCLUSIONS

Patients with untreated adult periodontitis are at greater risk of bacteremia due to periodontal probing than patients with chronic gingivitis. For individuals at risk of infective endocarditis, radiographic assessment prior to periodontal probing would be advisable to identify those with periodontitis so that appropriate antibiotic prophylaxis can be provided.

In vitro antimicrobial susceptibilities of three Porphyromonas spp and in vivo responses in the oral cavity of cats to selected antimicrobial agents

OBJECTIVES

To determine in vitro susceptibility of Porphyromonas gingivalis, P salivosa and P circumdentaria to seven antimicrobial agents by agar dilution and Epsilometer test methods and to assess the effectiveness of these antimicrobial agents in reducing the numbers of each Porphyromonas spp in the oral cavity of 16 domestic cats.

DESIGN

A two-part prospective study involving in vitro antimicro-bial studies using Porphyromonas spp obtained from naturally occurring feline infections and in vivo antimicrobial response studies using client-owned cats with naturally occurring periodontal disease.

PROCEDURE

Isolates (n = 25) of three feline Porphyromonas spp from the oral cavity and oral-associated disease were tested for their in vitro susceptibility to amoxycillin, amoxycillin-clavulanate, benzylpenicillin, clindamycin, doxycycline, erythromycin and metronidazole, using agar dilution and Epsilometer test methods. Digoxigenin-labelled whole chromosomal DNA probes directed against P gingivalis VPB 3492, P circumdentaria NCTC 12469T and P salivosa VPB 3313 were used to quantify organisms taken from two sample sites at the gingival margins of these cats prior to, and 5 days after, treatment with one of four commonly used antimicrobial products (amoxycillin-clavulanate, clindamycin, doxycycline or spiramycin-metronidazole). The response to treatment was assessed clinically for each cat.

RESULTS

All isolates were susceptible in vitro to all seven antimicrobial agents using both methods. The numbers of P gingivalis were not reduced at the gingival sample sites by administration of amoxycillin-clavulanate for 5 days, although this treatment reduced the numbers of P salivosa and P circumdentaria to below detection levels in six of eight and two of three of sample sites, respectively; clinical improvement was not observed in cats treated with amoxycillin-clavulanate. Treatment with clindamycin, doxycycline or spiramycin-metronidazole resulted in clinical improvement and a marked reduction of all Porphyromonas isolates at the sample sites.

CONCLUSION

The Epsilometer test is a simple and accurate method for determining the minimum inhibitory concentration for P gingivalis, P salivosa and P circumdentaria. All strains were susceptible in vitro to all the antimicrobial agents tested although clinical improvement of gingival disease was not noted with amoxycillin-clavulanate when given for 5 days at usual doses. This appears to be the first report of the disparity between the in vivo and in vitro susceptibility of oral bacterial strains to amoxycillin-clavulanate in the veterinary dental literature. This also appears to be the first report in which clinical and microbiological responses to commonly used antimicrobial agents for periodontal disease in cats has been documented and quantified. It was shown that treatment with clindamycin, spiramycin-metronidazole or doxycycline not only produced a substantial reduction in the number of Porphyromonas spp (in the majority of cases to below detection levels), but also resulted in substantial clinical improvement. This would indicate that these antimicrobial agents are useful adjunctive therapy to mechanical debridement in domestic cats.

Bacterial isolates from blood cultures of dogs undergoing dentistry

Bacteria in blood cultures in 30 dogs undergoing high-speed dental scaling and tooth extraction were examined. One or more positive blood cultures were identified in 9 of 30 (30%) dogs. Pasteurella spp. were most frequently (5 dogs) isolated and were sensitive to ampicillin, penicillin, cephalothin, chloramphenicol, tetracycline, amoxicillin with clavulanic acid, and sulfamethoxazole with trimethoprim. Two groups of 15 dogs each, anesthetized or sedated but not undergoing dental procedures, served as non-dentistry controls. There were no significant (p < .05) differences between the number of positive cultures in dentistry and non-dentistry groups. In healthy dogs undergoing high-speed dental scaling and tooth extraction, the occurrence of bacteria in blood cultures was much lower than previously reported. The clinical significance of positive blood cultures was uncertain.

Bacteremia following subgingival irrigation and scaling and root planing

The purpose of this study was to determine the incidence of bacteremia after a single professional subgingival irrigation with a 0.12% chlorhexidine gluconate mouthrinse (CHX) as well as after a subsequent scaling and root planing (S/RP) during the same visit. Thirty subjects each with at least 1 site that probed 4 mm or more and bled on probing were randomly assigned to the following groups: 1) irrigation with 0.12% CHX; 2) irrigation with sterile water; and 3) non-irrigated controls. To begin the study blood was drawn just before and 2 minutes after irrigation. Thirty minutes later, blood was drawn again just before and 2 minutes after S/RP at the same site. Specimens were cultured for anaerobic and aerobic microorganisms using standard cultural techniques. Eighteen blood cultures from 15 subjects yielded positive cultures resulting in 23 isolates. Gram-positive rods comprised 34.8% of the total isolates; Gram-positive cocci 34.8%, Gram-negative rods 21.7%, and Gram-negative cocci 8.7%. In the CHX group, bacteremia was detected in 5 subjects after irrigation and in 2 other subjects after S/RP. In the water group, bacteremia was detected in one subject after irrigation and in 4 subjects after S/RP. The control group had 3 bacteremias after S/RP. There was no significant difference between the incidence of bacteremia associated with irrigation by CHX or sterile water (P = 0.141). There was also no significant difference in the incidence of bacteremia after S/RP between the CHX and sterile water irrigation groups and in patients who did not receive irrigation (control group) (P = 0.88).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of subgingival irrigation on bacteremia following scaling and root planing

The purpose of this study was to determine the effects of professional subgingival irrigation, together with subsequent patient administered home marginal irrigation, on the incidence of bacteremia after scaling and root planing (Sc/RP). A total of 60 periodontal maintenance patients were assigned to either Group 1: subgingival irrigation, with 0.12% CHX and daily marginal irrigation with 0.04% CHX; Group 2: subgingival irrigation with 0.12% CHX and daily marginal irrigation with water; Group 3: subgingival and daily marginal irrigation with water; Group 4: Non-irrigation (control). Patients entered the study after receiving a thorough periodontal maintenance appointment including a complete examination, Sc/RP, and standard oral hygiene instruction. Blood samples were taken at the 3-month visit before and after Sc/RP. Microbiological culturing was done using the Septi-Chek system, selective and non-selective media. Results from 54 patients showed that bacteremia was detected prior to Sc/RP in 2 patients and after Sc/RP in 10 patients. No significant effect by treatment regimens on post Sc/RP bacteremia could be detected. The organisms isolated included Eubacterium lentum, Propionibacterium acnes, Streptococcus species, Neisseria species, Candida albicans, Staphylococcus species, and un-identified Gram-negative rods.

Toothbrushing and transient bacteremia in patients undergoing orthodontic treatment

A study was made to determine the extent of bacteremia experienced by patients undergoing orthodontic treatment with fixed appliances during periods of routine oral hygiene--namely, brushing the teeth. Sixteen orthodontic patients made up the population--11 who practiced good oral hygiene and five who demonstrated poor oral hygiene. Blood was drawn aseptically from the median cubital vein of the subjects before and 15 minutes after brushing the teeth. An aliquot of each blood specimen was added to separate blood culture bottles and incubated at 37 degrees C for a period of up to 5 days. Blood was also used to determine the immune status of the subjects. Anaerobic bacteria were recovered from the blood of nine of the 16 patients studied; aerobic bacteria were not recovered. A negative blood culture before brushing and positive blood culture after brushing were expected but did not occur. Some subjects showed bacteremia before brushing and a negative blood culture after brushing. Others showed bacteremia before and after brushing. The unexpected results could be attributed to the patients eating and/or brushing before starting the test. The study showed the capacity of specific anaerobic bacteria to remain in the bloodstream for a 15-minute period. It also demonstrated a presence of bacteria in the bloodstream before the test began.

Pathogenesis of periodontitis

Periodontitis is an inflammatory disease of the periodontium which is characterized by a progressive destruction of the tissues supporting the tooth. Its primary etiology is an ill-defined series of microbial infections which may be composed of only some of the more than 300 species of bacteria currently recognized in the oral cavity. The disease is currently considered to progress as periodic, relatively short episodes of rapid tissue destruction followed by some repair, and prolonged intervening periods of disease remission. Despite the apparent random distribution of episodes of disease activity, the resulting tissue breakdown exhibits a symmetrical pattern of alveolar bone loss and pocket formation which is common to several forms of periodontitis, although the distribution of the most affected teeth and surfaces may vary among diseases (e.g., juvenile periodontitis versus adult periodontitis or rapidly progressive periodontitis). Several reports have indicated that bacterial cells can be found in the pocket wall of periodontitis lesions. The translocation of bacteria into the tissues from the pocket environment is quite common, as evidenced by the common occurrence of bacteremias in patients with periodontitis following relatively minor events such as chewing and oral hygiene procedures. However, it is important to distinguish between the passive introduction of bacteria into periodontal tissues and frank invasion as might occur in an acute infection, since the pathological implications may be quite different.

Localization of blood-borne bacteria in instrumented unfilled root canals

The tissue fluid content of instrumented but unfilled root canals of five cats were analyzed for possible localization and growth of intravenously injected bacteria. Although it was possible to maintain a bacteremia for at least 120 minutes, the results showed that the test organisms were not capable of being attracted in the stagnant tissue fluid of the unfilled root canals. Even 48 hours after injection, all samples obtained from the canals were negative for the test organism. The phenomenon of "anachoresis" in unfilled root canals could not be documented under the experimental design.

Experimental transient bacteraemias in human subjects with varying degrees of plaque accumulation and gingival inflammation

Ninety-six subjects were assigned to one of four groups according to severity of gingival inflammation and bacterial plaque accumulation on the teeth. Following a standardized toothbrushing procedure, blood specimens from a vein in the antecubital fossa were cultured under aerobic and stringent anaerobic conditions. The percentage of positive cultures increased significantly with increasing severity of gingival inflammation, as did the number of species of organisms isolated. Thirty different microbial species indigenous to the oral cavity, including many strict anaerobes, were recovered. The study has implications for standards of oral health which might be considered necessary in patients with congenital or acquired endocardial defects or cardiovascular prostheses.