AUTHOR=Katkowska Marta , Garbacz Katarzyna , Kwapisz Ewa , Suligowska Klaudia , Kusiak Aida , Cichońska Dominika , Świetlik Dariusz 

TITLE=High oral carriage of multidrug resistant Gram-negative bacilli in adolescents: the SOPKARD-Junior study

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=13

YEAR=2023

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2023.1265777

DOI=10.3389/fcimb.2023.1265777

ISSN=2235-2988

ABSTRACT=<sec><title>Introduction</title><p>The colonization of the oral cavity by potentially pathogenic antimicrobial-resistant bacteria in adolescents and its consequences is very poorly understood. The present study focused on the occurrence of oral colonization by Gram-negative bacilli (GNB) and their multidrug resistance, including the production of extended-spectrum β-lactamases (ESBLs) and carbapenemases, among healthy adolescents and risk factors associated with GNB colonization.</p></sec><sec><title>Materials and methods</title><p>This study was conducted as part of “A program for the early detection of risk factors for lifestyle diseases SOPKARD-Junior” (SOPKARD-Junior). Oral samples were collected from 182 adolescents from four public elementary schools in Sopot, Poland, aged 13-14 years. Bacterial strains were identified by the MALDI-TOF MS method. Screening of antimicrobial resistance was performed using a disk diffusion method. The NG-Test<sup>®</sup> CARBA-5 was used to detect and differentiate the five most widely distributed carbapenemases. Demographic and clinical data were collected and statistical analysis of risk factors was performed.</p></sec><sec><title>Results</title><p>A total of 68 out of 182 (37.4%) healthy adolescents was documented oral colonization with Gram-negative bacilli, including 50/182 (27.5%) multidrug resistant (MDR-GNB) strains. Over 60% of oral carriage concerned three main genera <italic>Enterobacter</italic> spp., <italic>Pseudomonas</italic> spp., and <italic>Serratia</italic> spp., which were detected in 22.1%, 19.1%, and 19.1% of participants, respectively. <italic>Citrobacter</italic> spp., <italic>Escherichia coli</italic>, <italic>Klebsiella</italic> spp., <italic>Hafnia</italic> spp., <italic>Aeromonas</italic> spp., <italic>Acinetobacter</italic> spp., and <italic>Stenotrophomonas</italic> spp. were also isolated. The antimicrobial resistance to ampicillin (100%), ceftazidime (69.1%), meropenem (60.3%), gentamycin (60.3%), piperacillin/tazobactam (52.9%), and piperacillin (45.6%) were the most common. Among 73.5% GNB strains multidrug resistance was observed, including all <italic>Pseudomonas</italic> spp. strains. Among MDR-GNB, 30.4% were resistant to four groups of antibiotics, half of the MDR <italic>Pseudomonas</italic> spp. strains were resistant to 10 groups of antibiotics. Extended-spectrum β-lactamases were produced by <italic>Enterobacter cloacae</italic>, <italic>Klebsiella</italic> spp., and <italic>Serratia</italic> spp. (7.4%). Colonization by ESBLs-positive GNB strains was significantly associated with recurrent respiratory infections, nasal congestion, and bronchitis (p&lt;0.05).</p></sec><sec><title>Conclusion</title><p>Our study revealed high oral carriage of multi-drug resistant Gram-negative bacilli in healthy adolescents and the association of ESBL-producing strains with respiratory infections. Further studies on oral colonization with GNB are necessary due to the possibility of distinct infections and the acquisition of antibiotic resistance by resident microbiota.</p></sec>