previous page   Pak Vet J, 2017, 37(2): 230-232   next page
Clonal Expansion of Sulfonamide Resistant Escherichia coli Isolates Recovered from Diarrheic Calves
Muhammad Adnan1, Hamayun Khan2, Jam Kashif,1 Shakoor Ahmad2, Ali Gohar3, Amjad Ali4, Muhammad Atif Khan1, Said Sajjad Ali Shah2, Mohammad Farooque Hassan7, Muhammad Irshad5, Nazir Ahmad Khan6 and Sadeeq ur Rahman3*
1Department of Pharmacology, Sindh Agriculture University Tando Jam; 2Department of Animal Health, The University of Agriculture Peshawar; 3College of Veterinary Sciences and AH, Abdul Wali Khan University, Mardan; 4Centre for​ Human Genetics​, ​Hazara, University​, Mansehra-​ Pakistan; 5Department of Preventive Dentistry, Aljouf University, Kingdom of Saudi Arabia; 6Department of Nutrition, The University of Agriculture, Peshawar; 7Shaheed Benazir Bhutto University of Veterinary and Animal Sciences, Sakrand Sindh, Pakistan; *Corresponding author:


A total of 30 Escherichia coli isolates from 50 random samples of diarrheic calves were screened against resistance to sulfonamides. Minimum inhibitory concentration (MIC) by microdilution method indicated that 25/30 (83.3%) were found resistant to sulfadimidine, 27/30 (90%) were resistant to sulfadiazine, while 22/30 (73.3%) were found resistant to sulfamethaxole. These phenotypically sulfonamide resistant isolates were then probed for the presence of Sul genes (Sul-1-3) by polymerase chain reaction (PCR) using specific primers. PCR results revealed that 23/25, 25/27 and 20/22 isolates carried Sul-1 gene, respectively. Interestingly, all these isolates were found negative for the presence of Sul-2 and Sul-3 genes. Of note, no Sul genes could be verified in 02 phenotypically resistant isolates. The abundance of Sul1 gene and absence of Sul-2 and Sul-3 genes indicating a clonal expansion of sulfonamide resistant E. coli that might be linked to excessive abuse of sulfonamides in animals.

Key words: Diarrhea, E. coli, Minimum inhibitory concentration, Sul genes, Sulfadimidine resistance


ISSN 0253-8318 (Print)
ISSN 2074-7764 (Online)