Spectrum and resistance determinants of oral streptococci clinical isolates

Abstract

The profiles of oral streptococci sensitivity to antibacterial drugs may reflect information about the presence of macroorganism resistance determinants. The aim of the work was to isolate the spectrum of oral streptococci from the microbiota of the oral cavity of patients and to determine their sensitivity to a wide range of antibiotics. A total of 342 microbial streptococcal isolates were isolated from saliva samples and a periodontal pocket and tested for antibiotic sensitivity. Species identification of streptococci was carried out using biochemical API test systems. Evaluation of antibiotic resistance was performed using E-tests. Real-time PCR was used to identify the presence of tetracycline and macrolide resistance genes. The study identified six types of oral streptococci: S. oralis, S. salivarius, S. mitis, S. sanguinis, S. anginosus and S. mutans. All streptococci were sensitive to linezolid and meropenem. The proportion of penicillin-resistant streptococci in the subgroup S. oralis / mitis / mutans was 47,8% versus 23,5% in the subgroup S. salivarius / sanguinis / anginosus (p = 0.020). Significant levels of resistance were revealed to macrolides (erythromycin) - 47,9%, tetracyclines (tetracycline) - 44,4% and quinolones (ofloxacin) - 41%. Multiple drug resistance (MDR) was detected in 31,9% of oral streptococcal isolates, a combination of erythromycin, tetracycline and ofloxacin resistance was prevalent in 79 isolates (23,1%). The most common genotypes of macrolides and tetracycline resistant oral streptococci (in 127 streptococcal isolates with combined resistance) were ermB-mefE + and tetM + tetQ-, respectively. Thus, S. oralis / mitis / mutans group streptococci predominated in the structure of antibiotic-resistant oral streptococci, including MDR. So, being in one of the most densely populated biotopes of a macroorganism, oral streptococci can mediate the transfer of resistance determinants to more pathogenic and clinically significant microorganisms, which requires careful monitoring of their level of susceptibility to antimicrobial agents.

Distribution and Antibiotic Resistance of Streptococci and Enterococci Isolated from Dental Caries and Healthy People

“…Nowadays, MDR bacterial infections constitute a significant health problem and significantly burden effective therapeutic strategies [21]. Our study showed high-level MDR (> 50%) in all species, which is nearly comparable with a report from Russia [27] and disagrees with another one in Iran [28], where only 7.8% were MDR.…”

Streptococcus mitis as a New Emerging Pathogen in Pediatric Age: Case Report and Systematic Review

“…A significant reduction in the antimicrobial susceptibility of VGS has been observed over the last few years [69], especially in the pediatric population [70], where Penicillin derivates are often used in clinical practices [71] and prophylaxis [72,73]. Our patient recovered without sequelae, despite the fact that the S. mitis isolated was resistant to amoxicillin, penicillin, and cefuroxime.…”

Detection of Multidrug resistant cariogenic bacteria among Diabetic Patients attending a Tertiary Hospital in Ado Ekiti, South-Western, Nigeria

“…In addition to caries, S. mutans is responsible for cases of infective endocarditis with a subset of strains being indirectly implicated with the onset of additional extraoral pathologies. During the past 4 decades, functional studies of S. mutans have focused on understanding the molecular mechanisms the organism employs to form robust biofilms on tooth surfaces, to rapidly metabolize a wide variety of carbohydrates obtained from the host diet, and to survive numerous (and frequent who have reported multi-resistance in the oral streptococci isolated from healthy children in Greek, also Davidovich et al( 2020) S. salivarius, S. mitis, S. sanguinis, S. anginosus and S. mutans. All streptococci were sensitive to linezolid and meropenem.…”