Microbiologie médicale et diagnostic

Phenotypic Screening of Aminoglycoside Resistance and their Transferability in Clinical Isolates of Klebsiella pneumoniae from India

Abstract

Nargis Alom Choudhury, Sunanda Deb, Anand Prakash Maurya, Debadatta Dhar Chanda, Atanu Chakravarty and Amitabha Bhattacharjee

Introduction: Klebsiella pneumonia is an emerging pathogen associated with multidrug resistance both in hospital and community settings. Aminoglycosides, considered to be second line drug for the treatment of such pathogens, become inactive due to acquisition of various resistance determinants by this organism.
Objective: The objective of the study was to screen the aminoglycoside resistant Klebsiella pneumonia from a tertiary referral hospital of northeast India and their transmission dynamics.
Method: A total of 177 consecutive, non-duplicate, clinical isolates of Klebsiella pneumonia were collected from patients from a period of September 2013 to February 2014. Screening for aminoglycoside resistance was performed. Transferability of aminoglycoside resistance was done by transformation assay. Genetic stability was checked by consecutive serial passage of 70 days. Incompatibility types were determined by PCR based replicon typing.
Result: Among 177 clinical isolates, 94 were screened to be resistant towards aminoglycoside group of antibiotics. The aminoglycoside resistance determinant was found to be transferable when transformants were selected in gentamicin (100 μg/ml) screen agar. Coresistance was also shown by these isolates. Gentamicin resistance was lost after 47 consecutive serial passages. F inc type (n = 17) was more predominant, followed by K/B (n = 11), Y (n = 13), I (n = 9) and P (n = 8) when plasmids were typed by PCR based replicon typing.
Conclusion: This study highlighted the transmission dynamics of aminoglycoside resistance determined which pose threat to the treatment option in hospital settings.