Detection of Colistin Resistant Enterobacteria Isolates from Human Fecal Samples in the Greater Accra Region of Ghana

Abstract

Background and Objective: Colistin resistance is a major threat to the treatment of multidrug-resistant gram-negative infections. The scarcity of alternative antibiotics and the rapid evolution of resistant bacteria make this a critical problem that needs to be addressed urgently. This study aimed at phenotypic detection of colistin resistance by enterobacteria in humans. Materials and Methods: As 135 stool samples were collected from patients presenting with diarrhea, dysentery and typhoid. Bacterial isolation was first done to identify the WHO-priority pathogens involved greatly in bacterial drug resistance. The bacterial isolates were screened against several dilutions of colistin sulfate antibiotics and the minimum inhibitory concentration was determined for each isolate. Results: Klebsiella species (62%) and Morganella morgani (16%) were the most prevalent enterobacteria isolated, with Escherichia coli (2%) being one of the least prevalent organisms isolated. As 86% of all isolates were resistant to colistin, while 14% were sensitive. There was no significant difference in the susceptibility pattern of the isolates based on age, gender, or sample collection location. Conclusion: The prevalence of colistin resistance amongst isolates from the gastrointestinal tract causing diarrheal infections is high. This study is an early warning sign highlighting the emergence of colistin resistance in Ghana.