Characterization of aminoglycoside resistance in gram negative bacteria isolated from human clinical samples and animal raw meat products

Abstract

Aminoglycosides are broad spectrum antibiotics active against aerobic and facultative anaerobic gram negative bacteria GNB Indiscriminative use of this class of antibiotic in clinical and food producing animals has emerged as serious threat as animal raw meat chicken mutton beef and fish has been identified as a major source of exposure and acquisition of resistance in humans The presence of these resistance genes on plasmids facilitate their dissemination Typing and characterization of resistance mechanisms is crucial for early recognition and containment of outbreaks The purpose of this study was to characterize the mechanisms mediating AG resistance in GNB from clinical and raw animal meat, to identify the diversity of plasmids involved, their occurrence with other resistance determinants and to recognize the strain types ST involved A total of 452 amikacin resistant non repetitive gram negative isolates were included in the present study Of them 386 were clinical isolates and 66 were animal meat isolates This study revealed that high level AG resistance encoding genes occurs universally in amikacin resistant clinical isolates In animal meat isolates it is uncommon AG resistance encoding genes do not occur solely They are found in association with other resistant determinants rendering the bacteria multidrug resistant Plasmid incompatible groups like IncF were the most common The bacterial strain type found in poultry is found in humans in this study and a strain type K pneumoniae ST231a common clone encountered among clinical strains worldwide has been found in a fish in this study indicating the distribution of similar strain types in humans and animal raw meat Continued surveillance measures in animals and humans are required to limit the spread of aminoglycoside resistance encoding genes to the human population and vice versa newline