Bacteria profile and antibiogram of the bacteria isolated from the exposed pulp of dog canine teeth

Antibiotic Susceptibility of Zoonotic Bacteria Isolated From Oral Cavities of Indigenous Dogs From Semi-Urban Areas in Uganda

Dog bites are a source of zoonotic infections to humans, such as pasteurellosis and meningitis. Zoonotic bacterial identification and their antibiotic susceptibility assessment are key towards the successful management of such infections. This study isolated and identified zoonotic bacterial species from the oral cavities of indigenous dogs and also determined their antibiotic susceptibility profile. Oral swab samples collected from 54 indigenous dogs (domestic [36] and stray [18]) were cultured on agar media, and then on selective-differential media. The colony morphology and conventional biochemical tests were used to identify the bacterial isolates. Antibiotic susceptibility was evaluated using the Kirby-Bauer disk diffusion method. A total of 232 bacterial isolates were obtained, from which 29 bacteria species (18 Gram-negative and 11 Gram-positive) belonging to 19 genera and 13 families were identified. Aerobic and anaerobic bacteria species constituted 69% and 31%, respectively. The most prevalent bacteria species was Staphylococcus aureus (10.8%) followed by Escherichia coli (9.5%), while Yersinia enterocolitica (0.4%) was the least common. Most bacteria species belonged to family Enterobacteriaceae (11) followed by Vibrionaceae (04). All the sampled dogs had a number of multi-drug-resistant superbugs in their oral cavities. However, all the tested bacterial isolates were only susceptible to imipenem and chloramphenicol. All the identified bacteria species were resistant to metronidazole, amoxicillin-clavulanic acid and ceftazidime. Therefore, antibiotics such as imipenem and chloramphenicol could be of better choice for managing dog bite infections compared to the antibiotics recommended by Uganda Clinical Guidelines, such as metronidazole and amoxicillin-clavulanic acid.

Oral flora of stray dogs and cats in Algeria: Pasteurella and other zoonotic bacteria

Background and Aim:

Knowledge of potentially pathogenic bacteria presents in the oral cavity of dogs and cats may be helpful in determining appropriate treatment for infected bite wounds. About 120.000 people are exposed to dog and cat bites every year in Algeria, but little is known about the dog and cat oral flora causing bite wound complications. The purpose of this study was to identify potential zoonotic bacteria from oral cavity of dogs and cats and to determine their susceptibility to antibiotics to contribute to the treatment of bite wound infection.

Materials and Methods:

Oral swabs from 100 stray dogs and 100 stray cats were collected and cultured in several media: Chocolate agar, MacConkey agar, and Mannitol Salt Agar. Bacterial isolates were identified using several commercial kits of the analytical profile index and tested for antibiotic susceptibility by disk diffusion method.

Results:

Overall, 185/200 (92.5%) dogs and cats carried zoonotic bacteria in their mouths, of which 55.13% (102/185) had at least two bacterial pathogens. 374 pathogenic strains belonging to 15 genera were isolated: Eleven were Gram-negative (Proteus, Pasteurella, Escherichia, Moraxella, Klebsiella, Acinetobacter, Enterobacter, Pseudomonas, Aeromonas, and NeisseriaHaemophilus) and four were Gram-positive (Staphylococcus, Streptococcus, and Corynebacterium, Bacillus). Fifty-one strains of Pasteurella were isolated from 44 carriers of Pasteurella (21 Pasteurella multocida, 21 Pasteurella pneumotropica, and 9 Pasteurella spp.). Pasteurella strains were tested for antibiotic resistance. Resistance to at least one drug was observed in 8 (15.68%) of Pasteurella isolates and two strains (3.92%) were found to be multidrug-resistant (to two or more drugs). Erythromycin, penicillin, and ampicillin were the antimicrobials to which the isolates showed greater resistance (7.84%, 5.88%, and 3.92%, respectively).

Conclusion:

To the best of our knowledge, this study is the first in Algeria to detect potential human pathogenic bacteria in the oral cavity of dogs and cats. It reveals that these animals have multiple zoonotic bacteria in their mouths including Pasteurella species, which may be multidrug-resistant.

Endodontic Microbiome of Fractured Non-vital Teeth in Dogs Determined by 16S rRNA Gene Sequencing

Dental fractures resulting in pulp exposure will lead to an endodontic infection with microbes from the oral cavity. However, data on the endodontic microbial composition in veterinary dentistry is lacking. The aim of this study was to examine the microbiome of naturally occurring primary endodontic infections in client-owned dogs. The endodontic microbiome of 10 non-vital teeth with exposed pulp cavities was assessed using a 16S rRNA gene sequencing approach. The results were compared to the microbiome of the subgingival plaque of the same teeth. Analysis revealed an abundant mixed microflora of a comparable richness and diversity and with mostly the same phyla obtained from sulcal and endodontic samples. However, further analysis revealed significant differences between sulcal and endodontic samples in the relative abundance of the most abundant phyla and genera, with the relative abundance of Bacteriodetes being significantly higher in endodontic samples. Although each sample presented a particular profile regarding the genera identified, Bacteroides was the most abundant genus in the endodontic samples. Snowella was also significantly more abundant in endodontic samples, while Porphyromonas and Fusobacterium were significantly more abundant in sulcal samples. We confirmed that the microbiome of the diseased endodontic system is comparably abundant with microorganisms to the healthy subgingival plaque indicating that previous culture-based studies of primary endodontic infections in dogs underestimated the richness and diversity of the endodontic microbiota.