Evaluation of Antibiotic Resistance and Prevalence Among Gram-negative Bacteria in Fecal-derived Lactose Sugar Tinctures: An In-depth Study"

Abstract

Background and Objective: Diarrheal diseases remain a significant health concern worldwide, necessitating detailed microbial analysis to guide treatment strategies. This study aimed to identify gram-negative bacteria from stool samples of affected individuals, focusing on their ability to ferment lactose and their resistance patterns to specific antibiotics. Methodology: Conducted at Shomali General Hospital from 2023 March to 2023 December, eighty stool samples were collected and cultured on MacConkey agar to distinguish lactose fermenting from non-fermenting gram-negative bacteria. The antibiotic sensitivity of the isolates was assessed using the disk diffusion method against ten antibiotics, in accordance with the 2017 Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Of the eighty samples analyzed, 78% showed lactose fermenting bacteria. The remaining 22% comprised non-lactose fermenters, with further analysis identifying 55% as Salmonella, 22% Pseudomonas, 11.5% Proteus, and 11.5% Shigella. Antibiotic sensitivity testing revealed Ciprofloxacin as the most effective antibiotic, inhibiting 95% of the bacteria, followed by Ceftriaxone at 85%. Ampicillin was the least effective, with a lower inhibition rate. Conclusion: The high prevalence of lactose fermenting gram-negative bacteria among the diarrheal samples underscores the importance of lactose fermentation as a diagnostic marker. The varying degrees of antibiotic resistance highlight the critical need for ongoing surveillance of resistance patterns to inform effective treatment regimens. This study emphasizes the utility of the disk diffusion method for antibiotic sensitivity testing, providing essential data for managing diarrheal diseases.