High prevalence of antibiotic resistance and biofilm formation in Salmonella Gallinarum

Reza Khaltabadi Farahani; Mina  Ebrahimi-Rad; Nader Shahrokhi; Amir Hossien  Khaltabadi Farahani; Seyed Ali Ghafouri; Maryam Rezaei; Safoora Gharibzadeh; Arash Ghalyanchi Langeroudi; Parastoo Ehsani

doi:10.18502/ijm.v15i5.13869

Reza Khaltabadi Farahani Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
Mina Ebrahimi-Rad Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
Nader Shahrokhi Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
Amir Hossien Khaltabadi Farahani Department of Animal Science, Faculty of Agriculture and Natural Resources, Arak University, Arak, Iran
Seyed Ali Ghafouri Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran
Maryam Rezaei Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
Safoora Gharibzadeh Department of Epidemiology, Pasteur Institute of Iran, Tehran, Iran
Arash Ghalyanchi Langeroudi Department of Microbiology and Immunology, School of the Veterinary Medicine, University Tehran, Tehran, Iran
Parastoo Ehsani Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran

DOI: https://doi.org/10.18502/ijm.v15i5.13869

Keywords: Salmonella; Poultry disease; Antibiotic resistance

Abstract

Background and Objectives: Antibiotic resistance is an indicator of the passively acquired and circulating resistance genes. Salmonella Gallinarum significantly affects the poultry food industry. The present study is the first study of the S. Gallinarum biofilm in Iran, which is focused on the characterization of the S. Gallinarum serovars and their acquired antibiotic resistance genes circulating in poultry fields in central and northwestern Iran.

Materials and Methods: Sixty isolates of S. Gallinarum serovar were collected from feces of live poultry. The bacteria were isolated using biochemical tests and confirmed by Multiplex PCR. Biofilm formation ability and the antibacterial resistance were evaluated using both phenotypic and genotypic methods. The data were analyzed using SPSS software.

Results: According to Multiplex PCR for ratA, SteB, and rhs genes, all 60 S. Gallinarum serovars were Gallinarum biovars. In our study, the antibiotic resistance rate among isolated strains was as follows: Penicillin (100%), nitrofurantoin (80%), nalidixic acid (45%), cefoxitin (35%), neomycin sulfate (30%), chloramphenicol (20%), and ciprofloxacin (5%). All isolates were susceptible to imipenem, ertapenem, ceftriaxone, ceftazidime, and ceftazidime+clavulanic acid. All sixty isolates did not express the resistance genes IMP, VIM, NDM, DHA, bla , and qnrA. On the other hand, they expressed GES (85%), OXA48 qnrB (75%), Fox M (70%), SHV (60%), CITM (20%), KPC (15%), FOX (10%), MOXM (5%), and qnrS (5%). All S. Galli- narum isolates formed biofilm and expressed sdiA gene.

Conclusion: Considering that the presence of this bacteria is equal to the death penalty to the herd, the distribution of resis- tance genes could be a critical alarm for pathogen monitoring programs in the region. This study showed a positive correla- tion between biofilm formation and 50% of tested resistance genes. Also, it was found that the most common circulating S. gallinarum biovars are multidrug-resistant.