Emergence of Multidrug Resistant Zoonotic Salmonella from Poultry of Savar, Bangladesh

Abstract

Salmonella infection is one of the major constraints of poultry farming that hindered its development in Bangladesh. A study was conducted to investigate Salmonellae involved in poultry infection on the basis of five variable farm code, serotypes, resistotypes, and plasmid profiles. The study was extended towards the drug resistant profile against 28 common antibiotics and molecular characterization of Salmonella poultry isolates of Savar, Bangladesh. The prevalence of Salmonella was found to be 21.1%. A large number of plasmid-free Salmonella isolates were found to be resistant to 10-15 groups of antibiotics. The very high unanticipated level of multidrug resistance (MDR) of the isolated Salmonella against 28 commonly used therapeutic antibiotics is probably due to widespread use of and easy access to various antimicrobials in the poultry, veterinary, and public health sector in Bangladesh. PCR of 84 isolates using Salmonella specific primers ascertained 79, 32 and 3 isolates to be invA sefA and fliC gene positive. Amplified Ribosomal DNA Restriction Analysis (ARDRA) profile using Alu I restriction endonuclease digestion of nearly full length 16S rRNA gene of the 84 isolates gave three different restriction types indicating no single source of infection. Sequencing of representatives of each ARDRA groups detected close similarity to S. Typhimurium, S. Enteritidis and S. Paratyphi within the poultry samples indicating significant zoonotic hazard. Presence of identical restriction types in isolates of five different farms indicates the possibility of intrafarm transmission of these bacteria. Emergence of such multidrug drug resistant zoonotic Salmonella isolates is indicative of devastating situation of poultry farms in Bangladesh questioning the proper control and management of this economic sector in Bangladesh.