Duodenal Dysbiosis and Relation to the Efficacy of Proton Pump Inhibitors in Functional Dyspepsia

Proton pump inhibitors (PPI) may improve symptoms in functional dyspepsia (FD) through duodenal eosinophil-reducing effects. However, the contribution of the microbiome to FD symptoms and its interaction with PPI remains elusive. Aseptic duodenal brushings and biopsies were performed before and after PPI intake (4 weeks Pantoprazole 40 mg daily, FD-starters and controls) or withdrawal (2 months, FD-stoppers) for 16S-rRNA sequencing. Between- and within-group changes in genera or diversity and associations with symptoms or duodenal factors were analyzed. In total, 30 controls, 28 FD-starters and 19 FD-stoppers were followed. Mucus-associated Porphyromonas was lower in FD-starters vs. controls and correlated with symptoms in FD and duodenal eosinophils in both groups, while Streptococcus correlated with eosinophils in controls. Although clinical and eosinophil-reducing effects of PPI therapy were unrelated to microbiota changes in FD-starters, increased Streptococcus was associated with duodenal PPI effects in controls and remained higher despite withdrawal of long-term PPI therapy in FD-stoppers. Thus, duodenal microbiome analysis demonstrated differential mucus-associated genera, with a potential role of Porphyromonas in FD pathophysiology. While beneficial effects of short-term PPI therapy were not associated with microbial changes in FD-starters, increased Streptococcus and its association with PPIeffects in controls suggest a role for duodenal dysbiosis after long-term PPI therapy.

Treatment of Porphyromonas gulae infection and downstream pathology in the aged dog by lysine-gingipain inhibitor COR388

COR388, a small-molecule lysine-gingipain inhibitor, is currently being investigated in a Phase 2/3 clinical trial for Alzheimer's disease (AD) with exploratory endpoints in periodontal disease. Gingipains are produced by two species of bacteria, Porphyromonas gingivalis and Porphyromonas gulae, typically associated with periodontal disease and systemic infections in humans and dogs, respectively. P. gulae infection in dogs is associated with periodontal disease, which provides a physiologically relevant model to investigate the pharmacology of COR388. In the current study, aged dogs with a natural oral infection of P. gulae and periodontal disease were treated with COR388 by oral administration for up to 90 days to assess lysine-gingipain target engagement and reduction of bacterial load and downstream pathology. In a 28-day dose-response study, COR388 inhibited the lysine-gingipain target and reduced P. gulae load in saliva, buccal cells, and gingival crevicular fluid. The lowest effective dose was continued for 90 days and was efficacious in continuous reduction of bacterial load and downstream periodontal disease pathology. In a separate histology study, dog brain tissue showed evidence of P. gulae DNA and neuronal lysine-gingipain, demonstrating that P. gulae infection is systemic and spreads beyond its oral reservoir, similar to recent observations of P. gingivalis in humans. Together, the pharmacokinetics and pharmacodynamics of COR388 lysine-gingipain inhibition, along with reduction of bacterial load and periodontal disease in naturally occurring P. gulae infection in the dog, support the use of COR388 in targeting lysine-gingipain and eliminating P. gingivalis infection in humans.

A randomised clinical study to determine the effect of a toothpaste containing enzymes and proteins on plaque oral microbiome ecology

The numerous species that make up the oral microbiome are now understood to play a key role in establishment and maintenance of oral health. The ability to taxonomically identify community members at the species level is important to elucidating its diversity and association to health and disease. We report the overall ecological effects of using a toothpaste containing enzymes and proteins compared to a control toothpaste on the plaque microbiome. The results reported here demonstrate that a toothpaste containing enzymes and proteins can augment natural salivary defences to promote an overall community shift resulting in an increase in bacteria associated with gum health and a concomitant decrease in those associated with periodontal disease. Statistical analysis shows significant increases in 12 taxa associated with gum health including Neisseria spp. and a significant decrease in 10 taxa associated with periodontal disease including Treponema spp. The results demonstrate that a toothpaste containing enzymes and proteins can significantly shift the ecology of the oral microbiome (at species level) resulting in a community with a stronger association to health.

Antimicrobial effect of linalool and α-terpineol against periodontopathic and cariogenic bacteria

Linalool and α-terpineol exhibited strong antimicrobial activity against periodontopathic and cariogenic bacteria. However, their concentration should be kept below 0.4 mg/ml if they are to be used as components of toothpaste or gargling solution. Moreover, other compounds with antimicrobial activity against periodontopathic and cariogenic bacteria should be used in combination.

Antimicrobial susceptibility of 800 anaerobic isolates from patients with dentoalveolar infection to 13 oral antibiotics

INTRODUCTION

The aim of this study was to determine the current antimicrobial susceptibility of the principle anaerobic pathogens involved in dentoalveolar infection, to 13 oral antibiotics, and to assess the value of each antibiotic in the management of the infection.

METHODS

A total of 800 isolates from patients with dentoalveolar infection (Prevotella species, Fusobacterium species, Porphyromonas species and Peptostreptococcus micros) were tested for their susceptibility to amoxicillin, amoxicillin/clavulanate, cefaclor, cefuroxime, cefcapene, cefdinir, erythromycin, azithromycin, telithromycin, minocycline, levofloxacin, clindamycin, and metronidazole using an agar dilution method.

RESULTS

Although the majority of Fusobacterium strains were resistant to erythromycin, azithromycin, and telithromycin, the remaining antibiotics demonstrated a high level of antimicrobial activity. P. micros and Porphyromonas species exhibited high susceptibility to all antibiotics tested in this study. In the case of Prevotella species, resistance to amoxicillin occurred in 34% of isolates and all of these resistant strains were found to produce beta-lactamase. Susceptibility of Prevotella strains to cefaclor, cefuroxime, cefcapene, cefdinir, erythromycin, azithromycin, and minocycline was found to correlate with amoxicillin susceptibility. Amoxicillin/clavulanate, telithromycin, clindamycin, and metronidazole exhibited high antimicrobial activity even against amoxicillin-resistant strains of Prevotella species.

CONCLUSION

Amoxicillin would still be advocated therefore as being a suitable first-line agent, while reduced susceptibility of Prevotella strains remains a matter of concern with penicillins. Amoxicillin/clavulanate, clindamycin, and metronidazole are useful alternatives in combating the anaerobic bacteria involved in dentoalveolar infection.

Susceptibilidad in vitro de bacterias anaeróbicas en infecciones pleuropulmonares

BACKGROUND

Aspirative pleuropulmonary infections are usually caused by anaerobic flora of the mouth, mainly Prevotella, Fusobacterium and Peptostreptococcus spp. Penicillin in high doses is the traditional treatment for this type of infections but the rising resistance developed in recent years has induced the empiric use of clindamycin, increasing treatment costs.

AIM

To study antimicrobial susceptibility of anaerobic bacteria isolated from pleuropulmonary infections.

MATERIAL AND METHODS

Thirty two strains obtained from bronchoalveolar lavage and 15 strains isolated from pleural effusions between 2000 and 2002, were studied. The phenotype of strains was identified using the semiautomated API 20 A method and their susceptibility to penicillin (PNC), clindamycin (CM) and chloramphenicol (CAF) was tested using the E test methods.

RESULTS

All the strains were susceptible to CAF, 95% to CM and 74.4% to PNC. The predominant genus was Prevotella, which also exhibited the higher resistance.

CONCLUSIONS

As CM and CAF are active "in vitro", high rates of clinical response should be expected. In contrast, PNC is less effective, especially against pigmented Prevotella.

Antimicrobial resistance and beta-lactamase production of clinical isolates of prevotella and porphyromonas species

BACKGROUND

This study determined the beta-lactamase production and the antimicrobial resistance of 72 Prevotella species and 48 Porphyromonas species isolated from different clinical specimens.

METHODS

All strains were identified using API 32 ID. The beta-lactamase production was determined by nitrocefin disks. E test strips of benzylpenicillin, ampicillin + sulbactam, cefoxitin, clindamycin, metronidazole and imipenem were tested for each strain.

RESULTS

Nineteen Prevotella melaninogenica, 18 Prevotella intermedia, 16 Prevotella denticola, 11 Prevotella loescheii and 8 Prevotella bivia strains were identified. Four were clindamycin resistant. The highest beta-lactamase production was found at a rate of 68.4% in P. melaninogenica species. Additionally, 33 Porphyromonas asaccharolytica and 15 Porphyromonas gingivalis strains were identified. None of them produced beta-lactamase.

CONCLUSION

In view of the emerging antibiotic resistance among anaerobes, the current local susceptibility profile of our Prevotella and Porphyromonas species will establish the basis for additional surveys tracing significant changes in the antimicrobial resistance of our clinical isolates.

Efficacy of ozone on survival and permeability of oral microorganisms

In the present study, we examined the effect of ozonated water on oral microorganisms and dental plaque. Almost no microorganisms were detected after being treated with ozonated water (4 mg/l) for 10 s. To estimate the ozonated water-treated Streptococcus mutans, bacterial cells were stained with LIVE/DEAD BacLight Bacterial Viability Kit. Fluorescence microscopic analysis revealed that S. mutans cells were killed instantaneously in ozonated water. Some breakage of ozonated water-treated S. mutans was found by electron microscopy. When the experimental dental plaque was exposed to ozonated water, the number of viable S. mutans remarkably decreased. Ozonated water strongly inhibited the accumulation of experimental dental plaque in vitro. After the dental plaque samples from human subjects were exposed to ozonated water in vitro, almost no viable bacterial cells were detected. These results suggest that ozonated water should be useful in reducing the infections caused by oral microorganisms in dental plaque.

The effects of plant extracts on microbial community structure in a rumen-simulating continuous-culture system as revealed by molecular profiling

An in vitro study in dual-flow continuous-culture fermentors was conducted with two different concentrations of monensin, cinnamaldehyde or garlic extract added to 1:1 forage-to-concentrate diet in order to determine their effects on selected rumen bacterial populations. Samples were subjected to total DNA extraction, restriction analysis of PCR amplified parts of 16S rRNA genes (ARDRA) and subsequent analysis of the restriction profiles by lab-on-chip technology with the Agilent's Bioanalyser 2100. Eub338-BacPre primer pair was used to select for the bacteria from the genera Bacteroides, Porphyromonas and Prevotella, especially the latter representing the dominant Gram-negative bacterial population in the rumen. Preliminary results of HaeIII restriction analysis show that the effects of monensin, cinnamaldehyde and garlic extract on the BacPre targeted ruminal bacteria are somewhat different in regard to targeted populations and to the nature of the effect. Garlic extract was found to trigger the most intensive changes in the structure of the BacPre targeted population. Comparison of the in silico restriction analysis of BacPre sequences deposited in different DNA databanks and of the results of performed amplified ribosomal DNA restriction analysis showed differences between the predicted and obtained HaeIII restriction profiles, and suggested the presence of novel, still unknown Prevotella populations in studied samples.

Aerotolerance of an endodontic pathogen

The purpose of this study was to determine the length of time it takes to kill obligate anaerobic bacteria in a root canal exposed to room air or 3% hydrogen peroxide. Twenty-five extracted, human, permanent teeth with single canals were used. All teeth were contaminated with the anaerobe, Porphyromonas endodontalis (ATCC #35406), and were divided into five groups of five teeth each. Group I was exposed to 5 min of atmospheric air. Group II was exposed to 3% hydrogen peroxide for 5 min. Group III was exposed to 45 min of atmospheric air. Group IV was exposed to 3% hydrogen peroxide for 45 min. Group V, the control teeth, never left the anaerobic gas chamber. The results showed that atmospheric air exposure for up to 45 min is inadequate for eliminating P. endodontalis. The groups that were exposed to hydrogen peroxide showed no growth of bacteria.

Susceptibility of oral bacteria to Melaleuca alternifolia (tea tree) oil in vitro

The in vitro activity of Melaleuca alternifolia (tea tree) oil against 161 isolates of oral bacteria from 15 genera was determined. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) ranged from 0.003 to 2.0% (v/v). MIC90 values were 1.0% (v/v) for Actinomyces spp., Lactobacillus spp., Streptococcus mitis and Streptococcus sanguis, and 0.1% (v/v) for Prevotella spp. Isolates of Porphyromonas, Prevotella and Veillonella had the lowest MICs and MBCs, and isolates of Streptococcus, Fusobacterium and Lactobacillus had the highest. Time kill studies with Streptococcus mutans and Lactobacillus rhamnosus showed that treatment with > or = 0.5% tea tree oil caused decreases in viability of >3 log colony forming units/ml after only 30 s, and viable organisms were not detected after 5 min. These studies indicate that a range of oral bacteria are susceptible to tea tree oil, suggesting that tea tree oil may be of use in oral healthcare products and in the maintenance of oral hygiene.

Sensitivity of genera Porphyromonas and Prevotella to the bactericidal action of C-terminal domain of human CAP18 and its analogues

This paper reports the effect of the synthesized 27-amino acid sequence in the C-terminal domain of human CAP18 (hCAP18), a human cationic antibacterial protein or cathelicidin, on certain strains belonging to the genera Porophyromonas and Prevotella. The domain binds lipopolysaccharides (LPS) from Porophyromonas gingivalis and Porophyromonas circumdentaria as well as enterobacterial LPS. Two analogues of hCAP18, designated LL/CAP18 and FF/CAP18, were also tested to determine whether additional activity was obtained. The analogue peptides replaced with hydrophobic and cationic amino acid residues showed more potent bactericidal and LPS-binding activities than the original one.

Antimicrobial properties of self-etching primer-bonding systems

Self-etching primers are now considered the new generation of dentin bonding systems that modify and incorporate the bacteria-containing smear layer into their bonding mechanism. The antibacterial effects of the self-etching primers Clearfil SE Bond, Mac Bond, Imperva FL Bond, One-Up BondF and Prompt L-Pop were evaluated using the bacteria Streptococcus mutans ATCC25175, Peptostreptococcus anaerobius, Peptostreptococcus prevotii, Peptostreptococcus asaccharolyticus, Lactobacillus acidophilus, Lactobacillus catenaforme, Lactobacillus jensenii, Actinomyces odontolyticus, Porphyromonas endodontalis, Clostridium ramosum, Prevotella oris, Prevotella denticola and Fusobacterium nucleatum, with a disk diffusion method. A single-bottle total-etch dentin adhesive (Excite) was used for comparisons and chlorhexidine (0.2%) was used as the positive control. After incubation, zones of inhibited bacterial growth were observed. One-Up BondF, Prompt L-Pop and Excite showed growth inhibition for all bacterial strains. The bonding agents of Clearfil SE Bond, Mac Bond and Imperva FL Bond were unable to inhibit the growth of Lactobacillus jensenii and Actinomyces odontolyticus, while the primers of these systems produced inhibition halos to all tested microorganisms greater than that of chlorhexidine.

Antibacterial effects of resinous retrograde root filling materials

The effect of three resinous retrograde root filling materials on the growth of four obligate anaerobic bacteria associated with endodontic infections was determined by using the agar diffusion inhibitory test. Samples of the following resinous materials (resin-modified, glass-ionomer cement, Fuji II LC; compomer, Dyract; and composite resin, Spectrum) were incubated for 1 week with the following anaerobic bacteria: Fusobacterium nucleatum, Porphyromonas gingivalis, P. endodontalis, and Prevotella intermedia. The freshly mixed and set resinous materials were placed into the prepared wells of agar plates inoculated with the test microorganisms for 1 week. After the end of the incubation period, the zone of growth inhibition was observed and measured. Analysis of variance of the mean diameter of the zone of inhibition indicated no statistically significant overall differences in the response of the black-pigmented Bacteroides species (p > 0.05). For F. nucleatum, Spectrum had more antibacterial effect against this bacteria than Dyract (p < 0.05). Additionally, Fuji II LC was ineffective against F. nucleatum (p < 0.05). However, positive control plates showed bacterial growth in all cases. Our data suggest that the antibacterial potency of polymerized materials varied considerably, depending on the type and the product tested.

Microbial susceptibility to calcium hydroxide pastes and their vehicles

The aim of this study was to investigate the susceptibility of some microorganisms commonly isolated from root canals to calcium hydroxide in combination with several vehicles by the agar diffusion method. Stainless-steel cylinders were placed on each inoculated agar medium. The test medications and their controls were placed inside the cylinders. The zones of growth inhibition were measured and recorded after the incubation period for each plate, and the results were analyzed statistically. Enterococcus faecalis was most resistant, whereas the anaerobic Porphyromonas endodontalis was more susceptible to all medications, followed by P. gingivalis and Prevotella intermedial intermedia. Ca(OH)2 + CMCP + glycerin showed significantly larger mean zones of inhibition when compared with the other medications. We conclude that anaerobic Gram-negative bacteria are more susceptible to calcium hydroxide pastes than facultative Gram-positive microorganisms.

Comparison of temporal changes in components of formalin guaiacol under several storage conditions

This study examined the effects of storage conditions such as time course, temperature, fluorescent light, and darkness on the components and antibacterial activity of formalin guaiacol (FG) used in endodontic treatment. We measured the quantities of formaldehyde and guaiacol in FG and antibacterial activities against Staphylococcus aureus, Porphyromonas gingivalis, and Porphyromonas endodontalis. The components and antibacterial activity of FG in the brown or transparent tightly sealed containers were not affected by temperature or fluorescent light throughout the 4 week test. However, in the loosely sealed containers, formaldehyde and guaiacol in FG sample decreased remarkably within one week, not only in a temperature- and time-dependent manner, but also under fluorescent light at 20 degrees C. Furthermore, the antibacterial activities in the FG sample were significantly attenuated in parallel with the decrease in formaldehyde levels. Fluorescent light caused color changes and crystallization of FG samples in the transparent containers. These results suggest that it is important to replace fresh FG every 5 to 7 days for endodontic treatment and that, in the dental office, it is advisable to store fresh FG in tightly sealed containers every 2 weeks to maintain its efficacy.

Antimicrobial activity of four root canal sealers against endodontic pathogens

The antibacterial effects of various types of widely used endodontic sealers have not been compared systematically on facultative or obligate anaerobic endodontic pathogens. The aim of this study was to evaluate the antimicrobial properties of four commonly used endodontic sealers: two epoxy-resin-based sealers (AH26, AH plus), one zinc-oxide eugenol-based sealer (N2), and one calcium hydroxide-based sealer (Sealapex). The testing microbes were four facultative anaerobic species (Streptococcus mutans, Streptococcus sanguis, Escherichia coli, and Staphylococcus aureus) and four obligate anaerobic species (Porphyromonas gingivalis, Porphyromonas endodontalis, Fusobacterium nucleatum, and Prevotella intermedia). The freshly mixed sealers were placed into the prepared wells of agar plates inoculated with the test microorganisms. After varying periods of incubation (2 days for facultative anaerobic species and 7 days for obligate anaerobic species), the zones of growth inhibition were observed and measured. All the sealers were distinctly different from each other in their antimicrobial activity. The sealers showed different inhibitory effects depending on the types and bacterial strains. N2 containing formaldehyde and eugenol proved to be the most effective against the microorganisms. The extreme antimicrobial potency of this root canal sealer must be weighted against its pronounced tissue toxic effect.

In vitro antibacterial activity of glass-ionomer cements

The in vitro antibacterial activity of the glass-ionomer restorative cements Ketac-Cem, Ketac-Bond, Ketac-Silver and Vitrebond was studied in conjunction with 32 strains of five bacteria involved in the development of caries: Streptococcus spp., Lactobacillus spp., Actinomyces spp., Porphyromonas spp. and Clostridium spp. The agar plate diffusion method was used for the cultures, which included a chlorhexidine positive control. All the glass-ionomer cements tested inhibited bacterial growth, but with considerable differences in the scope of their action. Of the four cements, Vitrebond, a resin-modified glass-ionomer cement, was determined to be the most effective bacterial inhibitor.

Multicenter survey of the changing in vitro antimicrobial susceptibilities of clinical isolates of Bacteroides fragilis group, Prevotella, Fusobacterium, Porphyromonas, and Peptostreptococcus species

In vitro surveys of antimicrobial resistance among clinically important anaerobes are an important source of information that can be used for clinical decisions in the choice of empiric antimicrobial therapy. This study surveyed the susceptibilities of 556 clinical anaerobic isolates from four large medical centers using a broth microdilution method. Piperacillin-tazobactam was the only antimicrobial agent to which all the isolates were susceptible. Similarly, imipenem, meropenem, and metronidazole were highly active (resistance, <0.5%), whereas the lowest susceptibility rates were noted for penicillin G, ciprofloxacin, and clindamycin. For most antibiotics, blood isolates were less susceptible than isolates from intra-abdominal, obstetric-gynecologic, and other sources. All isolates of the Bacteroides fragilis group were susceptible to piperacillin-tazobactam and metronidazole, while resistance to imipenem and meropenem was low (<2%). For these same isolates, resistance rates (intermediate and resistant MICs) to ampicillin-sulbactam, cefoxitin, trovafloxacin, and clindamycin were 11, 8, 7, and 29%, respectively. Among the individual species of the B. fragilis group, the highest resistance rates were noted among the following organism-drug combinations: for clindamycin, Bacteroides distasonis and Bacteroides ovatus; for cefoxitin, Bacteroides thetaiotaomicron, B. distasonis, and Bacteroides uniformis; for ampicillin-sulbactam, B. distasonis, B. ovatus, and B. uniformis; and for trovafloxacin, Bacteroides vulgatus. For the carbapenens, imipenem resistance was noted among B. fragilis and meropenem resistance was seen among B. fragilis, B. vulgatus, and B. uniformis. With few exceptions all antimicrobial agents were highly active against isolates of Prevotella, Fusobacterium, Porphyromonas, and Peptostreptococcus. These data further establish and confirm that clinically important anaerobes can vary widely in their antimicrobial susceptibilities. Fortunately most antimicrobial agents were active against the test isolates. However, concern is warranted for what appears to be a significant increases in resistance to ampicillin-sulbactam and clindamycin.

Lethal photosensitization for decontamination of implant surfaces in the treatment of peri-implantitis

Peri-implantitis is considered to be a multifactorial process involving bacterial contamination of the implant surface. A previous study demonstrated that a combination of toluidine blue O (100 microgram/ml) and irradiation with a diode soft laser with a wavelength of 905 nm results in an elimination of Porphyromonas gingivalis (P. gingivalis), Prevotella intermedia (P. intermedia), and Actinobacillus actinomycetemcomitans (A. actinomycetemcomitans) on different implant surfaces (machined, plasma-flame-sprayed, etched, hydroxyapatite-coated). The aim of this study was to examine the laser effect in vivo. In 15 patients with IMZ implants who showed clinical and radiographic signs of peri-implantitis, toluidine blue O was applied to the implant surface for 1 min and the surface was then irradiated with a diode soft laser with a wavelength of 690 nm for 60 s. Bacterial samples were taken before and after application of the dye and after lasing. The cultures were evaluated semiquantitatively for A. actinomycetemcomitans, P. gingivalis, and P. intermedia. It was found that the combined treatment reduced the bacterial counts by 2 log steps on average. The application of TBO and laser resulted in a significant reduction (P<0.0001) of the initial values in all 3 groups of bacteria. Complete elimination of bacteria was not achieved.

Antimicrobial activity of honokiol and magnolol isolated from Magnolia officinalis

The antimicrobial activity of honokiol and magnolol, the main constituents of Magnolia officinalis was investigated. The antimicrobial activity was assayed by the agar dilution method using brain heart infusion medium and the minimum inhibitory concentration (MIC) were determined for each compound using a twofold serial dilution assay. The results showed that honokiol and magnolol have a marked antimicrobial effect (MIC = 25 microg/mL) against Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia, Micrococcus luteus and Bacillus subtilis, but did not show antimicrobial activity (MIC > or = 100 microg/mL) for Shigella flexneii, Staphylococcus epidermidis, Enterobacter aerogenes, Proteus vulgaris, Escherichia coli and Pseudomonas aeruginosa. Our results indicate that honokiol and magnolol, although less potent than tetracycline, show a significant antimicrobial activity for periodontal pathogens. Hence we suggest that honokiol and magnolol might have the potential to be an adjunct in the treatment of periodontitis.

Incidence of beta-lactamase production and antimicrobial susceptibility of anaerobic gram-negative rods isolated from pus specimens of orofacial odontogenic infections

The incidence of beta-lactamase production in anaerobic gram-negative rods isolated from 93 pus specimens of orofacial odontogenic infections and the antimicrobial susceptibility of these isolates against 11 antibiotics were determined. A total of 191 anaerobic gram-negative rods were isolated from the specimens. Beta-lactamase was detected in 35.6% of the black-pigmented Prevotella and 31.9% of the nonpigmented Prevotella. However, no strains among the other species isolated produced beta-lactamase. Ampicillin, cefazolin and cefotaxime showed decreased activity as regards beta-lactamase-positive Prevotella strains, whereas the activity of ampicillin/sulbactam, cefmetazole, and imipenem continued to be effective against such strains. All tested beta-lactam antibiotics were effective against Porphyromonas and Fusobacterium. Erythromycin showed decreased activity against nonpigmented Prevotella and Fusobacterium. Clindamycin, minocycline and metronidazole were powerful antibiotics against which anaerobic gram-negative rods could be tested. The present study showed that beta-lactamase-positive strains were found more frequently in the Prevotella strains than in any of the other species of anaerobic gram-negative rods. The effectiveness of adding sulbactam to ampicillin was demonstrated, as well as the difference in cephalosporin activity against beta-lactamase-positive strains.

[Bactericidal activity of Trovafloxacin and Moxifloxacin against Gram-negative anaerobic bacilli]

Anaerobes are often involved in human pathology, including oral infections. The therapy of anaerobic infection requires certain antibiotics such as: metronidazole, tetracycline or amoxicillin. But the incidence of resistant strains among anaerobes is continuously increasing and it is necessary to find some new agents effective against these bacteria. The aim of our study was to establish the bactericidal activity of two new quinolones against 14 strains of gram-negative anaerobic bacilli. The MIC of tested strains was first detected and then time-kill kinetics was determined by using Miles and Misra methodology. Ciprofloxacin was used as standard-quinolone. The results show that trovafloxacin and moxifloxacin have good activity against anaerobes, better than that of ciprofloxacin. Bactericidal curves suggest a rapid action of moxifloxacin (within the first 4 hours), but a prolonged cidal activity for trovafloxacin (24 hours). For both agents, the antimicrobial effect is concentration-dependent. As previous studies suggest, the new quinolones have good activity against both aerobic and anaerobic bacteria so they are useful in the treatment of mixed infections (common feature of anaerobic infections).

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.

Bacteroides, Prevotella, and Porphyromonas species: a review of antibiotic resistance and therapeutic options

Recent basic and clinical research efforts have shed more light on the taxonomy, microbiology, epidemiology, antimicrobial susceptibility and treatment of Bacteroides, Prevotella, and Porphyromonas species. Of all anaerobic bacteria, Bacteroides is the most frequently isolated pathogen from clinical specimens, including blood. Bacteroides, Prevotella and/or Porphyromonas species have been isolated from clinical specimens in cases of infection from almost all anatomic sites. Several multicentre surveys have documented an alarming gradual increase of resistance rates of Bacteroides, Prevotella and Porphyromonas species worldwide. Antimicrobial agents active against >99% of clinical isolates of Bacteroides are metronidazole, chloramphenicol and carbapenems. Agents active against 95-99% of Bacteroides fragilis isolates are the beta-lactam/beta-lactamase inhibitor combinations. B. fragilis group species other than B. fragilis are more likely to be resistant to beta-lactam/beta-lactamase inhibitor combinations than B. fragilis.

Detection of tetQ and ermF antibiotic resistance genes in Prevotella and Porphyromonas isolates from clinical specimens and resident microbiota of humans

Gram-negative anaerobes belonging to the genera Fusobacterium, Prevotella and Porphyromonas were investigated for the presence of tetQ and ermF, which have been shown to be spread by conjugal elements. One hundred isolates from either sites of infection or various body sites in healthy subjects were studied. PCR was used to detect tetQ, and DNA-DNA hybridization studies on EcoRI chromosomal digests were undertaken to detect the presence of tetQ and ermF. Antibiotic sensitivity assays were performed on selected isolates to detect tetracycline, erythromycin and penicillin resistance. Twenty Fusobacterium isolates lacked tetQ, and were tetracycline sensitive. Twenty per cent of Prevotella spp. isolates both from clinical specimens and from healthy subjects were found to possess tetQ. Of 20 Porphyromonas isolates tested, one (Porphyromonas levii) from a case of bacterial vaginosis was shown to possess tetQ in the chromosome. The presence of tetQ was always associated with tetracycline resistance. Four isolates of Prevotella melaninogenica and one isolate of Prevotella were ermF-positive, although expression of erythromycin resistance was not consistently associated with detection of this gene. Antibiotic resistance phenotypes of Prevotella isolates were shown to be related to specific chromosomal restriction patterns by hybridization studies: tetracycline resistance and tetracycline/erythromycin resistance are conferred by Bacteroides tetracycline-resistant ERL elements, whereas the tetracycline/penicillin resistance phenotype could be due to spread of elements identified in Prevotella only. Tetracycline/erythromycin-resistant and tetracycline/erythromycin/penicillin-resistant P. melaninogenica isolates were found in this study. It appeared that the presence of tetQ and ermF in Bacteroides and Prevotella contributed to the persistence of antibiotic resistance isolates within the host and to potential spread to other organisms through conjugal elements.

Review of the in vitro activity of gemifloxacin against gram-positive and gram-negative anaerobic pathogens

Published reports on the in vitro activity of gemifloxacin mesylate (SB 265805), a new fluoronaphthyridone, against anaerobic pathogens are reviewed here. The studies used a variety of media, inocula and antimicrobial agents. Using a proposed breakpoint of 0.5 mg/L, these studies showed that gemifloxacin had generally higher potency against Gram-positive anaerobes (Clostridium perfringens, all Peptostreptococcus spp.) and fusobacteria (Fusobacterium nucleatum, Fusobacterium necrophorum) and moderate but variable potency against Gram-negative anaerobes. Bacteroides stercoris, Bacteroides tectum and many Bacteroides fragilis isolates were inhibited by concentrations of < or =0.5 mg/L, while the other species of the B. fragilis group required higher concentrations for inhibition. Species variability was evident: Porphyromonas asaccharolytica, Porphyromonas canoris, Porphyromonas gingivalis, Porphyromonas macaccae, Prevotella heparinolytica and Prevotella intermedia were susceptible to 0.5 mg/L of gemifloxacin while most other Porphyromonas and Prevotella spp. were not. These data suggest that gemifloxacin may have a clinical role in the treatment of certain dental, head and neck and pleuropulmonary infections in which Gram-positive anaerobes, fusobacteria and some Prevotella and Porphyromonas spp. may predominate.

Namibian chewing stick, Diospyros lycioides, contains antibacterial compounds against oral pathogens

The twigs of Diospyros lycioides, a plant commonly known as "muthala", are frequently used as chewing sticks for the cleaning of teeth by rural and urban people in Namibia. Preliminary studies showed that a methanol extract of D. lycioides inhibited growth of selected oral pathogens. Subsequent bioassay-guided fractionation led to the isolation of four novel bioactive naphthalene glycosides, diospyrosides A, B, C, and D (1-4), and two known bioactive naphthoquinones, juglone (5) and 7-methyljuglone (6). The structures of the new compounds were elucidated using spectroscopic techniques including 1D and 2D NMR. These compounds inhibited the growth of oral cariogenic bacteria (Streptococcus mutans and Streptococcus sanguis) and periodontal pathogens (Porphyromonas gingivalis and Prevotella intermedia) at minimum inhibitory concentrations ranging from 0.019 to 1.25 mg/mL. Juglone exhibited the strongest inhibitory activity among these compounds.

In vitro antimicrobial activity of propolis and Arnica montana against oral pathogens

Arnica and propolis have been used for thousands of years in folk medicine for several purposes. They possess several biological activities such as anti-inflammatory, antifungal, antiviral and tissue regenerative, among others. Although the antibacterial activity of propolis has already been demonstrated, very few studies have been done on bacteria of clinical relevance in dentistry. Also, the antimicrobial activity of Arnica has not been extensively investigated. Therefore the aim here was to evaluate in vitro the antimicrobial activity, inhibition of adherence of mutans streptococci and inhibition of formation of water-insoluble glucan by Arnica and propolis extracts. Arnica montana (10%, w/v) and propolis (10%, w/v) extracts from Minas Gerais State were compared with controls. Fifteen microorganisms were used as follows: Candida albicans--NTCC 3736, F72; Staphylococcus aureus--ATCC 25923; Enterococcus faecalis--ATCC 29212; Streptococcus sobrinus 6715; Strep. sanguis--ATCC 10556; Strep. cricetus--HS-6; Strep. mutans--Ingbritt 1600; Strep. mutans--OMZ 175; Actinomyces naeslundii--ATCC 12104, W 1053; Act. viscosus OMZ 105; Porphyromonas gingivalis; Porph. endodontalis and Prevotella denticola (the last three were clinical isolates). Antimicrobial activity was determined by the agar diffusion method and the zones of growth inhibition were measured. To assess cell adherence to a glass surface, the organisms were grown for 18 h at 37 degrees C in test-tubes at a 30 degree angle. To assay water-insoluble glucan formation, a mixture of crude glucosyltransferase and 0.125 M sucrose was incubated for 18 h at 37 degrees C in test-tubes at a 30 degree angle. Arnica and propolis extracts (20 microl) were added to these tubes to evaluate the % of inhibition of cell adherence and water-insoluble glucan formation. The propolis extract significantly inhibited all the microorganisms tested (p < 0.05), showing the largest inhibitory zone for Actinomyces spp. The Arnica extract did not demonstrate significant antimicrobial activity. Cell adherence and water-insoluble glucan formation were almost completely inhibited by the propolis extract at a final concentration of 400 microg/ml and 500 microg/ml, respectively. The Arnica extract showed slight inhibition of the adherence of the growing cells (19% for Strep. mutans and 15% for Strep. sobrinus) and of water-insoluble glucan formation (29%) at these same concentrations. Thus, the propolis extract showed in vitro antibacterial activity, inhibition of cell adherence and inhibition of water-insoluble glucan formation, while the Arnica extract was only slightly active in those three conditions.

[Clinical efficacy of cefpirome sulfate against Bacteroides species, Prevotella species and Porphyromonas species. Society of Anaerobic Bacterial Infections in the fields of obstetrics and gynecology in Gifu]

The injectable cephalosporin cefpirome (CPR) was launched in Japan in 1993. It has widely been used in the various infectious diseases. We therefore studied the clinical and bacteriological efficacy of CPR against infections caused by Bacteroides species, Prevotella species and Porphyromonas species frequently isolated from the obstetric and gynecologic infections. Thirteen institutions were involved in this study which ran from March 1994 to January 1999. The administration dosage of CPR was 2 to 4 gram per day administered by drip infusion or intravenous infusion. The duration of treatment was from 3 to 15 days. The evaluations were performed before and after the treatment. CPR was administered to 194 patients with obstetric and gynecologic infections, and 146 of 194 cases were acceptable for the evaluation of drug efficacy. Bacteroides species were identified in 102 patients. Clinical efficacy in 146 cases was excellent in 12 patients, good in 110, fair in 9 and poor in 15 patients. The eradication rate for Bacteroides species could be in 37 cases out of 54 evaluable cases; Prevotella species in 38 out of 49; and Porphyromonas species in 5 out of 5. The overall assessment of bacteriological efficacy was "eradicated" in 91 cases out of 133 (68.4%). Adverse reactions including abnormal findings in laboratory tests were seen in 8 patients (4.76%). Based on these results, CPR promises efficacy and safety in the treatment of obstetric and gynecologic infections due to Bacteroides species.

Antibacterial activity of glass-ionomer restorative cements exposed to cavity-producing microorganisms

The antibacterial activity of the glass-ionomer restorative cements Ketac-Fil, Ketac-Silver, Fuji II LC, and Vitremer was studied in vitro, in conjunction with a total of 32 strains of five bacterial genera that may be associated with dental caries: Streptococcus spp, Lactobacillus spp, Actinomyces spp, Porphyromonas spp, and Clostridium spp. Agar plate diffusion was the method used for the bacterial cultures, which included a chlorhexidine control. All four glass-ionomer cements were found to inhibit bacterial growth, though with noteworthy differences in their spheres of action. Vitremer was the cement determined to have the greatest antibacterial effects, whereas Ketac-Silver presented the least inhibitory action.

[Investigations into the occurrence and the antibiotic susceptibility of gram negative anaerobes of the genera Bacteroides, Prevotella, Porphyromonas and Fusobacterium in specimens obtained from diseased animals]

From different samples of 247 diseased animals (cattle, sheep, goat, horse, pig, dog, cat, rodent, zoo-animals), 410 strains of gram-negative anaerobes were cultured. 297 isolates (72.4%) could be differentiated to the species level by using cultural-biochemical methods, gaschromatography and cell-wall-lipidanalysis. They belonged to 29 different species. For an additional 113 strains (27.6%) only the genus could be determined. Bacteria belonging to the genus Fusobacterium occurred with the highest isolation rates (36% of all strains) in the samples examined, followed by Bacteroides spp. (26.1%), Prevotella spp. (19.9%) and Prophyromonas spp. (17.8%). Fusobacterium necrophorum was the single species isolated most frequently. Antibiotic susceptibility tests by E-test were performed on 100 strains belonging to the the above mentioned genera. Of these strains 18% were resistant to penicillin and 20% to tetracycline. The resistant strains belonged mainly to the Bacteroides fragilis-group. Resistant rates to most other antimicrobial agents tested were Amoxicillin in combination with clavulanic acid: 1%, Chloramphenicol: 3%, Clindamycin:8%. All 100 selected strains proved to be susceptible to Metronidazol.

Influence of different vehicles on the antibacterial effects of calcium hydroxide

This study evaluated the influence of three different vehicles on the antibacterial activity of calcium hydroxide against four bacterial species commonly found in endodontic infections. For this purpose, a broth dilution test using 24-well cell culture plates was performed. Results showed that all pastes were effective in killing the bacteria tested, but at different times. The calcium hydroxide/camphorated paramonochlorophenol/glycerin paste was the most effective against the four bacterial strains tested.

Antibacterial effects of endodontic irrigants on black-pigmented gram-negative anaerobes and facultative bacteria

The antibacterial effect of endodontic irrigants was evaluated against four black-pigmented Gram-negative anaerobes and four facultative anaerobic bacteria by means of the agar diffusion test. All solutions used were inhibitory against all bacterial strains tested. A 4% NaOCl solution provided the largest average zone of bacterial inhibition of this study that was significantly superior when compared with the other solutions, except 2.5% NaOCl (p < 0.05). Based on the averages of the diameters of the zones of bacterial growth inhibition, the antibacterial effects of the solutions could be ranked from strongest to weakest as follows: 4% NaOCl; 2.5% NaOCl; 2% chlorhexidine; 0.2% chlorhexidine, EDTA, and citric acid; and 0.5% NaOCl.

Clinical and microbiological effects of controlled-release local delivery of minocycline on periodontitis in dogs

OBJECTIVE

To evaluate the clinical and microbiological efficacy of minocycline in a subgingival local delivery system as an adjunct to tooth scaling and root planing in dogs with periodontal disease.

ANIMALS

Nine 4- to 7-year-old Beagles with periodontitis.

PROCEDURE

After scaling of teeth and root planing, 2 treatment and 1 or 2 control sites were selected for each dog: treated sites (n = 18) received minocycline hydrochloride periodontal formulation and control sites (n = 12) received ointment base (no minocycline). Gingival crevicular fluid was collected at a baseline (prior to treatment) and at week 4. Clinical and microbiological effects were evaluated and compared among sites.

RESULTS

In minocycline-treated sites, clinical indices were significantly decreased at week 4, compared with those at baseline. Minocycline-treated sites were associated with a significant decrease in gingival crevicular fluid, probing depth, and bleeding on probing values, compared with those for control sites at week 4. Compared with that for control sites, total bacteria count in periodontal pockets of minocycline-treated sites had an obvious tendency to decrease by week 4. Proportions of Porphyromonas and Fusobacterium spp were significantly decreased at week 4, compared with proportions at control sites and with pretreatment (baseline) values.

CONCLUSIONS

When used as an adjunct to tooth scaling and root planing, minocycline periodontal formulation stimulated favorable clinical and antimicrobial responses.

[In vitro activity of 10 antibiotics including pristinamycin and its two components (RP 12536 and 27404) against strict anaerobes]

The activities of the pristinamycin and its two components (RP 12536 and RP 27404) were investigated using the reference agar dilution method M11A3, on 175 anaerobic strains in comparison with that of erythromycin, clindamycin, metronidazole, amoxycillin either alone or combined with clavulanic acid, piperacillin, cefoxitin, cefotetan and cefotaxime. beta-lactamase production was detected for all the 55 B. fragilis group strains and 8/12 Prevotella and 2/18 Fusobacterium strains, respectively. On the whole anaerobes, resistance rates (%) were respectively: RP 27404 (69), RP 12536 (64), pristinamycin (5) erythromycin (31), clindamycin (17), metronidazole (7) amoxycillin (24), amoxycillin-clavulanic acid (2), piperacillin (7), cefoxitin (14), cefotetan (21) and cefotaxime (27). RP 27404 and 12536 had low activities on anaerobes but acted synergistically as pristinamycin. The greatest anti-anaerobic potencies were obtained with amoxycillin-clavulanic acid combination, pristinamycin, metronidazole and piperacillin. As resistance was not found for pristinamycin among Prevotella, Fusobacterium, Gram+ rods and Peptostreptococcus, this streptogramin may be an appropriate agent for the treatment of periodontitis, pulmonary, ENT, gynecologic and soft tissue infections where these anaerobes are frequently involved.

Isolation and characterization of a nonpigmented variant of Porphyromonas endodontalis

Porphyromonas endodontalis forms dark colonies on media containing blood. We isolated, from an infected root canal, a non-black-pigmented P. endodontalis variant, KSEW01, which forms beige colonies on blood agar media. To characterize this variant, we compared its properties with those of two black-pigmented P. endodontalis strains, ATCC35406 and KSE105. Strain KSEW01 had a gelatinase activity comparable to that of the pigmented strains. Cell lysates of these three strains resolved by SDS-PAGE electrophoresis showed similar protein patterns. Quantitative DNA-DNA hybridization experiments indicated high homology between the nonpigmented strain KSEW01 and the two dark-pigmented strains. From these results, we identified strain KSEW01 as a P. endodontalis nonpigmented variant. DNA restriction endonuclease analysis indicated that the variant was closely related to a pigmented strain, KSE105. In contrast to the pigmented strains, strain KSEW01 did not degrade hemoglobin and formed no vesicles when cultured in the presence of blood. The susceptibilities of these three strains to 22 antibiotics were similar except for vancomycin. The nonpigmented variant was the most resistant to vancomycin (MIC: ATCC35406, 6.25 micrograms/ml; KSE105,12.5 micrograms/ml; KSEW01, 100 micrograms/ml). Overall, a relationship may exist between the presence of black-pigmentation and outer membrane systems of P. endodontalis.

Microbiology of the transition from acute to chronic maxillary sinusitis

Repeated aspirations of sinus secretions by endoscopy was performed in five patients over a period of 34-50 days and, ultimately, surgical drainage was done in three who presented with acute maxillary sinusitis that did not respond to antimicrobial therapy and became chronic. The aspirates were cultured for aerobic and anaerobic bacteria. Most of the bacteria isolated from the first culture were aerobic or facultative bacteria: Streptococcus pneumoniae (three isolates), Haemophilus influenzae non-type-b (two) and Moraxella catarrhalis (one). Three of these cultures yielded bacteria that were resistant to the antimicrobial agents prescribed for treatment. Failure to respond to therapy was associated with the emergence of resistant aerobic and anaerobic bacteria in subsequent aspirates. These organisms included Fusobacterium nucleatum, pigmented Prevotella and Porphyromonas spp. and Peptostreptococcus spp. Eradication of the infection was achieved in all instances following the administration of antimicrobial agents effective against these bacteria, and in three instances by surgical drainage. This study illustrates the microbial dynamics of maxillary sinusitis that did not respond to antimicrobial therapy.

Phototoxicity of argon laser irradiation on biofilms of Porphyromonas and Prevotella species

Species of Prevotella (Pr.) and Porphyromonas (Po.) and other microorganisms were cultivated as biofilms on agar medium and examined for their susceptibility to argon laser irradiation (continuous mode; wavelengths, 488-514 nm; fluences, 20-200 J cm(-2)). Fluences of 35 to 80 J cm(-2) inhibited biofilm growth in Po. endodontalis, Po. gingivalis, Pr. denticola, Pr. intermedia, Pr. melaninogenica and Pr. nigrescens. A fluence of 70 J cm(-2) did not affect biofilm growth in species of Bacillus, Candida, Enterobacter, Proteus, Pseudomonas, Staphylococcus and Streptococcus. The phototoxic effects of argon laser irradiation against Prevotella and Porphyromonas species were: (1) caused by the radiation alone; (2) modified by biofilm age; (3) dependent on the presence of atmospheric oxygen; (4) influenced by medium supplements of hemin, hemoglobin and blood; (5) greater when compared with other microbial species; (6) demonstrated without augmentation with an exogenous photosensitizer; and (7) apparently unrelated to the protoporphyrin content of the cells. Overall, these in vitro findings suggest that low doses of argon laser radiation may be effective in the treatment and/or prevention of clinical infections caused by biofilm-associated species of Prevotella or Porphyromonas.

[Antimicrobial activities of cefteram against recently clinically detected and isolated strains from patients with dental infections]

To investigate the antibiotic activity of cefteram (CFTM), the minimum inhibitory concentrations (MICs) of CFTM and of the control drugs were determined against clinically isolated strains received from November 1991 to April 1993 from 19 dental facilities throughout the country, as well as against clinically isolated strains from samples obtained at this center from patients with dental infectious diseases, and the following results were obtained. 1. 430 strains were detected in 198 cases but identified strains amounted to 425. They are comprised of 204 strains of oral streptococci (48.0%), 81 strains of Peptostreptococcus spp. (19.1%), 10 strains of Bacteroides spp. (2.4%), 23 strains of Prevotella spp. (5.4%), and 9 strains of Porphyromonas spp. (2.1%). The ratios of Gram-positive bacteria v.s. Gram-negative bacteria were 78.4% and 21.6%, respectively, and the Gram-positive bacteria were isolated at higher frequency than Gram-negative bacteria. 2. The MIC90's of CFTM against oral streptococci and Peptostreptococcus spp. were 0.10 microgram/ml and 0.05 microgram/ml, and year to year increases of incidences of resistance against CFTM were not observed. Some strains, however, appeared to have obtained resistance to CFTM. 3. Among Bacteroides spp., Prevotella spp., Porphyromonas spp. which used to belong to genus Bacteroides, there were some strains resistant to CFTM. As a whole, however, no year to year increases in the incidence of CFTM resistance among these strains also. 4. Two strains of 6 Staphylococcus aureus subsp. aureus were methicillin-resistant. 5. The above observations indicate that CFTM still shows strong antimicrobial activity against clinically isolated strains that may be involved in dental infections.

The efficacy of tinidazole in naturally occurring periodontitis in dogs: bacteriological and clinical results

The efficacy of tinidazole in addition to a single course of scaling was studied in 14 dogs with periodontitis. Three test teeth, two with periodontitis and one with healthy periodontium, were selected per dog. Subgingival bacterial samples were taken, and clinical examination was carried out at each of four visits (0, 14, 90 and 180 days). The bacterial samples were cultured anaerobically using selective and nonselective media. All teeth in the dentition, except one diseased test tooth with periodontitis were scaled at the first visit and tinidazole or placebo administered twice a day for 7 days. The mean probing depth of the diseased test pockets was significantly more reduced in tinidazole+scaling (T1S1) than scaling alone (T0S1) group at all visits compared to baseline values. The most significant decreases of bacterial counts in T1 or T0 groups were found in agar corroding Gram-negative rods in both diseased and healthy T1S1 pockets and in slimy Gram-negative rods in diseased T1S0 pockets between visits 1 and 2. The intergroup comparisons showed that Gram-positive cocci decreased significantly more in S1 pockets as well as sporeforming Gram-positive rods in diseased S0 pockets of T1 than T0 group. The highest number of isolates was found in the group of pigmented Gram-negative anaerobe rods, mainly Porphyromonas spp. The percentage of Porphyromonas gingivalis-like isolates decreased to zero and Porphyromonas endodontalis-like isolates increased in all test teeth of T1 group at 14 days. It is concluded that tinidazole has good efficacy against P. gingivalis-like bacteria which seem to be periodontal pathogens in dogs.