Molecular identification and antibiogram profile of Vibrio cholerae isolates from diarrheal patients in Northwestern Pakistan

Abstract

Vibrio cholerae, the causative agent of cholera, remains a significant public health concern in Khyber Pakhtunkhwa, Pakistan. This study investigated the prevalence and antimicrobial susceptibility patterns of V. cholerae in stool samples collected from diarrheal patients from July 2022 to August 2023. A total of 361 stool samples were collected and cultured on Thiosulphate Citrate Bile Sucrose Agar (TCBS) media. Ninety-one (25.20%) samples were identified as V. cholerae through biochemical tests followed by PCR amplification of the 16S rRNA gene. The highest infection rate was observed in the age group of ≤ 18 years (59.34%), with males (60.40%) being more affected than females (39.60%). The summer season accounted for the highest proportion of V. cholerae cases (68.13%). Chi-square tests revealed significant correlations between age groups, gender, and seasonal variation with V. cholerae positivity (p<0.001, p=0.026, and p<0.001, respectively). Geographically, Peshawar had the highest number of cases (37.36%), followed by Dir and Swat (24.17% each), and Mardan (14.30%). Antibiotic susceptibility testing showed that fluoroquinolones, particularly ciprofloxacin (71.93% susceptibility) and levofloxacin (66.67% susceptibility), were the most effective antibiotics. However, high resistance levels were observed against sulfamethoxazole-trimethoprim (71.42%), azithromycin (64.92%), tetracycline (77.50%), ampicillin (81.25%), and erythromycin (94%). Multidrug-resistant and extensively drug-resistant isolates constituted 19.78% and 17.58% of the total, respectively. District-wise analysis revealed varying susceptibility patterns, suggesting differing antibiotic selection pressures and possible circulation of region-specific strains. These findings highlight the importance of targeted preventive measures during high-risk periods and among vulnerable demographic groups, as well as the need for continued surveillance of antibiotic resistance in V. cholerae.