Molecular characteristics of antibiotic resistance in different haemophilus influenzae serotypes

• Published in: Malaysian Journal of Biochemistry and Molecular Biology
• Main Author: Raffie A.N.M.; Palanisany N.K.; Houssaini J.; Ahmad N.; Zain Z.M.
• Format: Article
• Language: English
• Published: Malaysian Society for Biochemistry and Molecular Biology 2018
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85055277491&partnerID=40&md5=4f0710ccfe3bc5e46ca6210da7182696

Antibiotic resistance in Haemophilus influenzae is increasingly common and caused significantburden in patients' management and treatment. Factors contributing to the resistance vary insome strains and depend on genetic elements they possessed. In this study, we aim to determinethe antibiotic resistant determinants in 18 clinical strains of Haemophilus influenzae.Serological typing has identified four strains to be H. influenzae type a (Hia) while fourteenwere non-typeable H. influenzae (NTHi). Antibiotic susceptibility testing using disk diffusionmethod was carried out to determine their susceptibility patterns against three types ofantibiotics. Strains that exhibited resistance to ampicillin (AMP), tetracycline (TE) or cotrimoxazole (SXT) were selected and underwent plasmid detection by PCR. These strains alsowere tested for the presence of integrative and conjugative elements (ICEs) and antibioticresistance genes. Multiple resistances were only seen in NTHi with two strains exhibitedresistance to all three antibiotics. AMP resistant gene (blaTEM-1) was detected in 7/8 AMPresistant strains; TE resistant genes, tet(B) was detected in 2/4 TE resistant strains and tet(M) inanother 1/4 strains. Both trimethoprim and sulfamethoxazole resistant genes (dfrA1 and sul2)present in only 2/6 SXT resistant strains and the other 4/6 strains lack either gene. ICEs werenot detected in Hia strains but present in six antibiotic resistant NTHi which represented by intand ofr51 genes. In conclusion, antibiotic resistance in Haemophilus influenzae is independentto the presence of ICEs and the genetic determinants of antibiotic resistance may differ amongstrains of Haemophilus influenzae. © 2018 Malaysian Society for Biochemistry and Molecular Biology. All rights reserved.