Susceptibilities of Eikenella corrodens, Prevotella intermedia, and Prevotella nigrescens clinical isolates to amoxicillin and tetracycline

Characterization and Antimicrobial Susceptibility of Pathogens Associated with Periodontal Abscess

Knowledge of microbial composition and antimicrobials' susceptibility to periodontal abscesses is vital for their successful treatment. The current study aims to provide a thorough overview of the clinical and microbial features of periodontal abscesses of the local community. The study was carried out at Rehman College of Dentistry, Peshawar, Pakistan between December 2019 to March 2020. Clinical measurements and microbial samples were collected from 45 subjects. Microbial samples were anaerobically cultured for the growth of selected bacterial species. E-test was used to assess the susceptibility of bacterial species grown from the patient samples to amoxicillin, azithromycin, metronidazole, and tetracycline. The majority of affected patients had preexisting chronic periodontitis. All abscesses clinically demonstrated bleeding on probing and suppuration. The periodontal abscess was most commonly associated with lower incisors and canines, followed by lower molars and then upper incisor and canine teeth. Fusobacterium spp. (73%) was the most frequently detected species followed by Prevotella intermedia/nigrescens (65%), Porphyromonas gingivalis (46%) and Aggregatibacter actinomycetemcomitans (24%). The detected clinical isolates of certain bacteria demonstrated resistance to all tested antibiotics except azithromycin. We conclude that Fusobacterium spp., P. intermedia/nigrescens, P. gingivalis, C. rectus, T. forsythia and A. actinomycetemcomitans are closely associated with periodontal abscess. Bacterial species associated with periodontal abscess demonstrated some level of antimicrobial resistance to amoxicillin, metronidazole and tetracycline while antibiotic resistance to azithromycin could not be demonstrated.

Antibiotic resistance of subgingival species in chronic periodontitis patients

BACKGROUND AND OBJECTIVE

The increasing rate of resistance of microorganisms to penicillin and other antibiotics has generated concern among health authorities in Latin America. The present investigation determined the in vitro susceptibility of Porphyromonas gingivalis, Fusobacterium nucleatum, black-pigmented Prevotella spp. and Aggregatibacter actinomycetemcomitans to metronidazole, amoxicillin, amoxicillin/clavulanic acid, clindamycin and moxifloxacin in patients with chronic periodontitis.

MATERIAL AND METHODS

Subgingival plaque samples from patients with periodontitis were collected and cultured on selective and nonselective culture media. The antimicrobial susceptibility of periodontopathogenic isolates was studied in chronic periodontitis patients in Colombia. Metronidazole, amoxicillin, amoxicillin/clavulanic acid, clindamycin and moxifloxacin were tested on all bacterial isolates and the percentage of resistant strains was calculated.

RESULTS

Of the 150 bacteria identified, 51 were P. gingivalis, 45 were black-pigmented Prevotella spp., 36 were F. nucleatum and 18 were A. actinomycetemcomitans. All the isolates were sensitive to amoxicillin/clavulanic acid and to moxifloxacin, but exhibited variable susceptibility patterns to the other antimicrobial agents tested.

CONCLUSION

The results of the present study suggest that periodontal microorganisms in patients with chronic periodontitis can be resistant to the antimicrobial agents commonly used in anti-infective periodontal therapy. We suggest that the indiscriminate use of antimicrobials could result in the appearance of more highly antibiotic-resistant strains of bacteria associated with periodontal diseases in our population compared with the populations of other countries.

The use of calcium hydroxide, antibiotics and biocides as antimicrobial medicaments in endodontics

Bacteria have been implicated in the pathogenesis and progression of pulp and periapical diseases. The primary aim of endodontic treatment is to remove as many bacteria as possible from the root canal system and then to create an environment in which any remaining organisms cannot survive. This can only be achieved through the use of a combination of aseptic treatment techniques, chemomechanical preparation of the root canal, antimicrobial irrigating solutions and intracanal medicaments. The choice of which intracanal medicament to use is dependent on having an accurate diagnosis of the condition being treated, as well as a thorough knowledge of the type of organisms likely to be involved and their mechanisms of growth and survival. Since the disease is likely to have been caused by the presence of bacteria within the root canal, the use of an antimicrobial agent is essential. Many medicaments have been used in an attempt to achieve the above aims but no single preparation has been found to be completely predictable or effective. Commonly used medicaments include calcium hydroxide, antibiotics, non-phenolic biocides, phenolic biocides and iodine compounds. Each has advantages and disadvantages, and further research is required to determine which is best suited for root canal infections.

Use of Appropriate Antimicrobials in Wound Management

The primary goal of wound management is to achieve a functional closure with minimal scarring. Preventing infection is important to facilitate the healing process. Most simple, uncomplicated wounds do not need systemic antibiotics but benefit from the use of topical antibiotics. Judicious use of antibiotics reduces unnecessary adverse events and helps reduce the development of resistance. Although antibiotics can help reduce infection risk and promote healing, they are not a substitute for good local wound care, in particular irrigation and surgical débridement. This article reviews the role of antibiotics in emergency department wound management.

Clinical and microbiological characterization of periodontal abscesses

BACKGROUND/AIM

The knowledge of clinical features, microbial composition and susceptibility to antimicrobials of periodontal abscesses has recently improved. This descriptive clinical and microbiological study provides more information on the characteristics of periodontal abscesses.

MATERIALS AND METHODS

Clinical parameters and subgingival samples were examined from 54 subjects presenting 60 periodontal abscesses. Samples were cultured for anaerobic and facultative bacteria, and data were expressed as frequency detection and mean proportion of isolation for microorganisms. Selected isolates of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans and Prevotella intermedia/nigrescens were used to test susceptibility to amoxicillin, azithromycin, tetracycline and metronidazole. Statistical descriptive analysis was conducted.

RESULTS

Most periodontal abscesses were present in patients with ongoing Chronic Periodontitis. Bleeding on probing, tumefaction and suppuration were present in almost all abscesses. Affected teeth were lower anterior teeth, upper anterior teeth and lower molars. The subgingival microbiota was composed of periodontal pathogens such as Fusobacterium spp. (75%), P. intermedia/nigrescens (60%), P. gingivalis (51%) and A. actinomycetemcomitans (30%). Some periodontopathogens showed antimicrobial resistance to tetracycline, metronidazole and amoxicillin, but not to azithromycin.

CONCLUSIONS

Periodontal abscesses showed typical clinical features associated with untreated periodontitis, and the organisms identified were important periodontopathic bacteria. Rationale use of antibiotic adjunctive therapy in abscess treatment should be taken into account.

Comparison of the antimicrobial activity of six irrigants on primary endodontic pathogens

The purpose of this study was to compare the antimicrobial activities of 6% and 3% sodium hypochlorite (NaOCl), 2% and 0.12% chlorhexidine gluconate (CHX), and 0.01% and 0.005% doxycycline (Doxy) on four microorganisms associated with primary endodontic infections. The agar diffusion test was used to measure antimicrobial activities of these agents against Peptostreptococcus micros, Prevotella intermedia, Streptococcus sanguis, and Lactobacillus acidophilus. Minimum inhibitory concentration analysis was performed using the macrodilution method. For three of the four microorganisms, the general order of antimicrobial effectiveness was 0.01% Doxy >0.005% Doxy >6% NaOCl >3% NaOCl >2% CHX > 0.12% CHX. For L. acidophilus, the order of effectiveness was 6% NaOCl >3% NaOCl >2% CHX > 0.01% Doxy >0.005% Doxy >0.12% CHX. The 6% NaOCl showed significantly greater zones of inhibition than 3% NaOCl for all endopathogens tested.

In vitro activities of tigecycline (GAR-936) and 12 other antimicrobial agents against 90 Eikenella corrodens clinical isolates

The activity of tigecycline was compared with those of other antimicrobials against 90 isolates of Eikenella corrodens. The MIC at which 90% of the isolates were inhibited was 2 micro g/ml for tigecycline and 1, </=0.5/0.25, 0.5, </=0.12, </=2, and 0.5 micro g/ml for ampicillin, amoxicillin-clavulanate, cefotaxime, imipenem, chloramphenicol, and ciprofloxacin, respectively.