Antibiogram of Extended-Spectrum Beta-LactamaseProducing Gram-Negative Bacteria Isolated from Patients with Periodontal Diseases Attending Dental Clinics in Enugu

Abstract

Introduction: This study was designed to determine the antibiogram and prevalence of Gram-negative bacteria (GNB) in patients with gingivitis and chronic periodontitis.

Materials and Methods: Exactly 180 gingival sulcus samples of patients’ jaws collected using paper points were placed in double strength nutrient broth and analysed using standard microbiological techniques. Identified bacteria were phenotypically screened for ESBL (Extended-Spectrum Beta-Lactamase)-production using Double Disk Synergy Test (DDST). Antimicrobial susceptibility of isolated ESBL-producing bacteria was determined using the Kirby–Bauer disk diffusion method.

Results: Results showed that age group > 36 years and above had the highest incidence of chronic periodontitis (46.5 %) and gingivitis (25 %). Pocket probing Depth ≥ 4 mm was common among chronic periodontitis patients (51.1 %) while probing depth ≤ 3 mm was prevalent amongst gingivitis patients (11.8 %). Bleeding on probing site ≥ 50 % was more predominant among chronic periodontitis patients with frequency of 41.5 %; followed by 28.2 % for patients with gingivitis. K. pneumoniae 65(19.2 %), E. coli 44(12.9 %), Salmonella spp 35(10.3 %), K. oxytoca 34(10 %), and P. aeruginosa 13(3.8 %) were the GNB isolated.

Conclusion: Out of the bacteria isolated, 106 (31.2 %) were phenotypically identified to be ESBL-producers. Isolates were generally  susceptible to gentamicin (50 %) and colistin sulphate (100 %), but completely resistant (100 %) to chloramphenicol, cefotaxime,  ceftazidime, trimethoprim-sulfamethoxazole, and tetracycline respectively. Multiple Antibiotic Resistance Index (MARI) values of the bacterial isolates ranged from 0.2-0.9. Periodontal and gingival sites of patients in this study harboured multidrug-resistant ESBL-producing GNB which may limit treatment options for periodontitis and gingivitis.

Keywords: Gram-Negative Bacteria, Antibiotic Resistance, Periodontitis, Gingivitis, ESBL.