Antibiotic Susceptibility and Resistance Genes in Oral Clinical Isolates of Prevotella intermedia, Prevotella nigrescens, and Prevotella melaninogenica

Abstract

The Prevotella genus is a normal constituent of the oral microbiota, and is commonly isolated from mechanically treated polymicrobial infections. However, antibiotic treatment is necessary for some patients. This study compared the antibiotic susceptibility and the presence of resistance genes in clinical oral isolates of P. intermedia, P. nigrescens, and P. melaninogenica. Antibiotic susceptibility was assessed using the agar dilution method. PCR confirmed the species and resistance gene frequency in the Prevotella species. The frequencies of species P. intermedia, P. nigrescens, and P. melaninogenica were 30.2%, 45.7%, and 24.1%, respectively. No isolates of P. intermedia were resistant to amoxicillin/clavulanic acid, tetracycline, or clindamycin. P. nigrescens and P. melaninogenica were resistant to amoxicillin/clavulanic acid and tetracycline at frequencies of 40% and 20%, respectively. P. intermedia was resistant to metronidazole at a frequency of 30%, P. nigrescens at 20%, and P. melaninogenica at 40%. P. nigrescens and P. melaninogenica were resistant to 50% and 10% clindamycin, respectively. The gene most frequently detected was tetQ, at 43.3%, followed by tetM at 36.6%, blaTEM at 26.6%, ermF at 20%, cfxA, cfxA2, and nimAB at 16.6%, and nimAEFI at 3.3%. P. nigrescens was the species with the highest resistance to antibiotics such as amoxicillin/clavulanic acid, amoxicillin, and clindamycin, in addition to being the species with the largest number of genes compared to P. intermedia and P. melaninogenica.

Polymicrobial Bacterial Meningitis in a Patient with Chronic Suppurative Otitis Media: Case Report and Literature Review

“…Although more often associated with abdominal infections (appendicitis, cholangitis, or diverticulitis), some authors recommended an appropriate evaluation of a possible abdominal or perineal source of infection in case of meningitis caused by Streptococcus anginosus [ 17 ]. In immunocompromised patients, this is frequently associated with other Gram-negative or anaerobic pathogens [ 18 ], as we have noted in our patient. In line with many other reports, the streptococcal bacteria isolated in CSF were susceptible to penicillin [ 19 ].…”

“…The strain of Prevotella involved in our case was not identified; it was sensitive to most beta–lactam antibiotics, except penicillin. Of the three most common Prevotella strains ( P. intermedia , P. melaninogenica , and P. nigrescens ), only P. intermedia was identified as susceptible to aminopenicillins, as in our case [ 18 ].…”

Case report: isolated prevotella intermedia causing intracranial infection detected using metagenomic next generation sequencing

“…Castillo et al previously reported on the antibiotic susceptibility and presence of resistance genes in clinical oral isolates of Prevotella intermedia. They found the frequency of resistance gene in Prevotella intermedia (species) to be 30.2% [ 34 ]. Furthermore, Prevotella intermedia was resistant to metronidazole at a frequency of 30%; however, no isolates of Prevotella intermedia were resistant to amoxicillin/clavulanic acid, tetracycline, or clindamycin [ 34 ].…”

“…They found the frequency of resistance gene in Prevotella intermedia (species) to be 30.2% [ 34 ]. Furthermore, Prevotella intermedia was resistant to metronidazole at a frequency of 30%; however, no isolates of Prevotella intermedia were resistant to amoxicillin/clavulanic acid, tetracycline, or clindamycin [ 34 ]. Notably, Prevotella intermedia ZT belongs to a genus marked with highly dynamic genomes.…”

Treatment of Periodontal Infections, the Possible Role of Hydrogels as Antibiotic Drug-Delivery Systems

“…In addition, more than 50% Prevotella species isolated from the clinical samples were beta lactamase-producing organisms with 17.1 to 26.3% resistance to amoxicillin; fortunately, these species were susceptible to amoxicillin-clavulanic acid [ 49 ]. Among the three Prevotella species studied for their antimicrobial resistance to first- and second-line antibiotics in PD treatment, in an in vitro study, a key aspect of the findings revealed that P. nigrescens had the highest amoxicillin, amoxicillin clavulanic acid and clindamycin [ 50 ]. In a recent retrospective study by Jepsen et al, 2021, an exponential increase in the resistance to selected antibiotics with associated with a statistically significant decline in susceptibility to prescribed antibiotics was observed [ 51 ].…”