Extended-spectrum beta-lactamase-producing bacteria are not detected in supragingival plaque samples from human fecal carriers of ESBL-producing Enterobacteriaceae

Abstract

BackgroundThe prevalence of infections caused by Cefotaximase-Munich (CTX-M)-type extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) has rapidly increased during the past 15 years. Enterobacteriaceae are commonly found in the gastrointestinal tract and long-term intestinal carriage is considered important for the spread of ESBL and as a source of clinical infections. Oral biofilm such as supragingival plaque is known to contain numerous antibiotic resistance determinants and may also represent a poorly investigated site for ESBL carriage and further spread.ObjectiveTo investigate possible carriage of ESBL-producing bacteria in supragingival plaque of known fecal carriers of these bacteria.DesignWe screened for the presence of aerobic and anaerobic ESBL-producing bacteria and bla CTX-M in supragingival plaque samples from healthy human adults with culture-verified fecal carriage of CTX-M-producing Escherichia coli. The presence or absence of Enterobacteriaceae and ESBL-producing bacteria in plaque samples was evaluated using culture-based methods and consensus CTX-M PCR.ResultsOral samples were obtained from 17 participants with known previous carriage of ESBL-producing E. coli. No ESBL-producing bacteria or ESBL genes were detected using culture-based and molecular methods. One colony of Rahnella aquatilis harboring the class A ESBL gene blaRAHN-1/2 was identified in an oral sample from one of the participants.ConclusionThis pilot study supports the notion that the presence of CTX-M-producing bacteria is uncommon in oral plaque of healthy human adult fecal carriers. Due to the limited number of persons tested, a low prevalence of oral ESBL-carriage in healthy adults or carriage in selected groups of patients cannot be excluded. To our knowledge, this is the first description of an R. aquatilis with the RAHN-1/2 gene in the oral cavity.

Prevalence and antimicrobial susceptibility of Gram‐negative bacilli in subgingival biofilm associated with periodontal diseases

“…Only one multidrug resistant strain of K. pneumoniae isolated from periodontitis showed carbapenemase activity and resistance to carbapenem, although no carbapenemase encoding genes were detected. 42,43 Discrepant findings between phenotypic susceptibility traits and presence of corresponding resistance genes carbapenems may occur due to non-carbapenemase-mediated mechanisms. [45][46][47][48] For instance, high-level expression of chromosomal or plasmid-mediated AmpC beta-lactamases, in combination with porin loss or mutation may account for the carbapenem resistance phenotype.…”

Infektionshygiejnens rolle i forebyggelse af antibiotikaresistens

“…Flere studier har de senere år undersøgt, om der kunne findes multiresistente isolater blandt disse bakteriearter fra mundhulen (tabel 1). I fire undersøgelser fra henholdsvis Sverige, Norge og USA isoleredes i alt 223 terobacteriacea, men ingen ESBL-producerende orale bakterier(34). For Enterobacteriaceae i øvrigt har enkelte studier rapporteret om ESBL-producerende stammer i mundhulen hos aeldre og svaekkede personer, men der er så vidt vides endnu ingen rapporter om orale infektioner med disse bakterier eller overførsel på tandklinikker(35).2019 • 129 • #3Staphylococcus aureus kan af og til isoleres fra mundhulen hos både børn og voksne, men udgør typisk kun en lille andel af mikrofloraen.…”