Main Article Content
Abstract
Background: Antimicrobial resistance represents a major public health challenge, reducing the effectiveness of commonly used antibiotics and complicating the treatment of bacterial infections. Monitoring antimicrobial susceptibility patterns among clinically relevant bacterial species is essential for guiding appropriate antimicrobial therapy. Objective: This study aimed to evaluate and compare the antimicrobial susceptibility and resistance patterns of six bacterial species against different antimicrobial agents. Methods: Laboratory antimicrobial susceptibility data were analyzed for Escherichia coli, Citrobacter spp., Klebsiella spp., Nitrobacteria sp., Pseudomonas spp., and Staphylococcus aureus. Susceptibility and resistance frequencies and percentages were calculated for each species and antimicrobial agent. Overall differences in susceptibility and resistance patterns among bacterial species were assessed using the Pearson chi-square test. Pairwise comparisons were subsequently performed using Pearson chi-square tests, with Holm adjustment to account for multiple comparisons. Statistical significance was set at p < 0.05. Results: A total of 2,129 antimicrobial susceptibility test responses were analyzed, comprising 924 susceptible responses 43.4%) and 1,205 resistant responses (56.6%). The highest overall resistance rate was recorded for Staphylococcus aureus (68.2%), followed by Citrobacter spp. (59.1%), E. coli (58.1%), Pseudomonas spp. (56.2%), Klebsiella spp. (49.6%), and Nitrobacteria sp. (48.8%). Significant differences in the overall susceptibility–resistance distributions were observed among the six bacterial species (χ² = 31.11, df = 5, p < 0.001). Holm-adjusted pairwise comparisons revealed significant differences between E. coli and Nitrobacteria sp. (p = 0.0113), E. coli and S. aureus (p = 0.0346), Klebsiella spp. and S. aureus (p < 0.001), Nitrobacteria sp. and S. aureus (p < 0.001), and Pseudomonas spp. and S. aureus (p = 0.0412). Conclusion: The findings demonstrate a considerable overall level of antimicrobial resistance, with marked variation among the investigated bacterial species. Staphylococcus aureus exhibited the highest resistance proportion, whereas Nitrobacteria sp. showed the lowest. These findings highlight the importance of continuous antimicrobial susceptibility surveillance and evidence-based antibiotic selection to support effective infection management and help limit the further emergence of antimicrobial resistance.
