Comprehensive Analysis of Salmonella Species Antibiogram and Evolving Patterns in Empirical Therapy: Insights From Tertiary Care Hospitals in Peshawar, Pakistan

Abstract

Background Typhoid fever presents a significant challenge in developing nations, exacerbated by the emergence of antibiotic-resistant strains due to widespread prevalence and overuse of antibiotics. This study seeks to assess the antibiogram profiles of Salmonella species isolated from blood cultures of patients hospitalized at two prominent tertiary care hospitals in Peshawar, Pakistan: Khyber Teaching Hospital (KTH) and Hayatabad Medical Complex (HMC). By examining these profiles, the research aims to provide valuable insights into the evolving landscape of antibiotic resistance in the context of typhoid fever management. Materials and Methods This retrospective cross-sectional study utilized data gathered from two hospitals in Peshawar, KTH and HMC. Cases of enteric fever were identified based on positive blood cultures for Salmonella species. The study encompasses demographic information, seasonal prevalence, and antibiogram profiles of 3,137 cases that were presented between 2017 and 2023. Results Among the total 3,137 cases, males accounted for the majority, comprising 63% (2,044 cases). Particularly notable was the clustering of cases among children and adolescents aged one to 24 years. The incidence peaked during the months of summer and spring, from April to September. In terms of Salmonella Typhi isolates, considerable resistance was noted against first-line antibiotics such as amoxicillin/clavulanate (80.1%), co-trimoxazole/trimethoprim-sulfamethoxazole (66.6%), and chloramphenicol (86.9%), as well as against ceftriaxone (79.7%) and ciprofloxacin (51.6%). Conversely, certain antibiotics displayed higher sensitivity patterns, including meropenem (97.8%), doripenem (99.5%), imipenem (97.7%), ertapenem (96.5%), polymyxin B (99.4%), colistin (98.1%), and tigecycline (97.3%). Despite a limited sample size of 214 specimens, fosfomycin demonstrated a remarkable sensitivity of 93.4%. Sensitivities of amikacin and gentamicin were 90.7% and 81.5%, respectively. However, the sensitivity of azithromycin was concerning, standing at 66.5%. The antibiogram pattern for Salmonella exhibited significant and drastic changes. Conclusion In conclusion, this study sheds light on a higher prevalence of typhoid fever among males, with a notable seasonal peak observed during the summer and spring months. The age group most affected spans from one to 24 years. Salmonella isolates displayed significant resistance to conventional first-line antibiotics, alongside ciprofloxacin and third-generation cephalosporins. Azithromycin exhibited lower sensitivity compared to amikacin, gentamicin, and fosfomycin. The research advocates for the empirical use of amikacin, gentamicin, fosfomycin, and meropenem in the treatment of typhoid fever in Pakistan. Urgent measures, including regular Salmonella antibiogram surveillance, antibiotic stewardship, public health education, and Salmonella vaccination programs, are deemed crucial for primary disease prevention.

Keywords: amikacin; antibiogram; antibiotic resistance; antibiotic sensitivity; empirical therapy; enteric fever; fosfomycin; meropenem; pakistan peshawar; salmonella species.

Figure 1. Gender-wise prevalence of typhoid fever

Figure 2. Age-wise prevalence. The highest prevalence seen was in age group 5-14 years age group (55.10%)

Figure 3. Monthly base prevalence of typhoid fever

Figure 4. Salmonella antibiogram susceptibility pattern

AMP: Ampicillin, AMC: Amoxicillin/Clavulanic acid, TZP: Piperacillin/tazobactum, CFP: Cefoperazone, CAZ: Ceftazidime, CRO: Ceftriaxone, CTX: Cefotaxime, FEP: Cefepime, CFM: Cefixime, ATM: Aztreonam, DOR: Doripenem, ETP: Ertapenem, IPM: Imipenem, MEM: Meropenem, AMK: Amikacin, GEN: Gentamicin, CIP: Ciprofloxacin, LVX: Levofloxacin, MFX: Moxifloxacin, SXT: Trimeth0prim/sulfamethoxazole, FOS: Fosfomycin, COL: Colistin, POL: Polymyxin B, AZM: Azithromycin, CHL: Chloramphenicol, TGC: Tigecycline.

Figure 5. Salmonella antibiogram resistant pattern

AMP: Ampicillin, AMC: Amoxicillin/Clavulanic acid, TZP: Piperacillin/tazobactum, CFP: Cefoperazone, CAZ: Ceftazidime, CRO: Ceftriaxone, CTX: Cefotaxime, FEP: Cefepime, CFM: Cefixime, ATM: Aztreonam, DOR: Doripenem, ETP: Ertapenem, IPM: Imipenem, MEM: Meropenem, AMK: Amikacin, GEN: Gentamicin, CIP: Ciprofloxacin, LVX: Levofloxacin, MFX: Moxifloxacin, SXT: Trimeth0prim/sulfamethoxazole, FOS: Fosfomycin, COL: Colistin, POL: Polymyxin B, AZM: Azithromycin, CHL: Chloramphenicol, TGC: Tigecycline.

Figure 6. Year-wise susceptibility pattern of Salmonella species from 2017-2023

Figure 7. Year-wise antibiotic-resistant pattern of Salmonella species from 2017-2023