Identification of Salmonella typhymorium and study of resistance pattern of cephalosporins and survey of prevalence of Bla-CTXM- 1 and class 1 integrase by PCR in Salmonella isolated from turkeys in Sistan

Samadi, Keyvan (2018) Identification of Salmonella typhymorium and study of resistance pattern of cephalosporins and survey of prevalence of Bla-CTXM- 1 and class 1 integrase by PCR in Salmonella isolated from turkeys in Sistan. Doctoral thesis, university of zabol.

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Salmonella is considered as an important pathogen for the poultry industry. Among salmonella, salmonella typhimurium has a special place, because both in terms of diversity of hosts and in terms of geographical diversity is high. Many researchers have concluded that using selective antibiotic can increase antibiotic resistance in human and animal bacteria such as salmonella. An antibiotic resistance transfer factor between bacteria is an integron, and the next is beta-lactam. Beta-lactams are a wide range of enzymes that, in addition to producing penicillin-resistance, interfere with the resistance to a wide range of cephalosporins. The acquired resistance of β-lactamase is mainly due to the CTX-M type broad-spectrum betalactamases. In this study, samples from 253 turkeys that were randomly selected from different regions of Zabol were obtained by colobacic swab and transferred to the Microbiology Laboratory of the Faculty of Veterinary Medicine in the TSB environment. Samples were evaluated by culture in lysine decarboxylase, salmonella - shigella agar, triple shooter agar, urea broth, macrocake agar and culture medium. The prevalence of Salmonella in Zabul's farms was 14.62% (37 salmonella from 253 samples). All specimens were evaluated and confirmed by culture and standard biochemical tests. The chromosomal DNA of all isolates was extracted by boiling method. In order to confirm the detection of Salmonella genus, an invA gene in 284 bp long was used, and a 559 bp gene fliC gene was used in PCR to detect the thyroid repellency of the typhimorium. The isolates that were negative for invA gene were removed and the remaining isolates were re-PCR for finding CTX-M-1 resistance genes of 593 bp and Integrase 1 at 160 bp. Finally, the samples were tested for antibiograms of different generations of cephalosporins and their sensitivity to each antibiotic was measured. The result of the antibiogram also showed: All samples (100%) were sensitive to cefipime antibiotic (FEP30), which is a fourth-generation cephalosporin. Antibiotic susceptibility is Cefepime > cefixime > Ceftriaxone = Cefoxitin = Cefalotin> Cefazolin. It was also found that in this study, resistance to two antibiotics cefoxitin and cefixime (15.15%) and resistance to two antibiotics ceftriaxone and cefepime were not observed. In this study, the frequency of invA and FliC genes in 37 samples of Salmonella in PCR was 89.18% (33 cases) and 51.35% (19 cases). The frequency of Int1 and Ctx-m-1 genes in 33 positive Salmonella isolates from turkey was 96.96% (32 cases) and 75.75% (25 cases), respectively. In this study, the prevalence of Integrase 1 and CTX-M-1 in salmonella isolated from turkeys in Zabol region was very high compared to other areas. Increasing the resistance to antibiotics in this study can be due to an over consumption and without antibiotics in the poultry industry. By continuously evaluating these resistances, especially at the national and regional levels, and subsequently by using specific measures for the level and type of antibiotic use on the flock level, the prevalence and diffusion of resistance can be greatly prevented.

Item Type: Thesis (Doctoral)
Uncontrolled Keywords: Salmonella typhimurium, CTX-M-1 beta-lactamases, Integrase 1, Cephalosporin, PCR, turkeys
Subjects: Q Science > QL Zoology
Depositing User: Mrs najmeh khajeh
Date Deposited: 31 Oct 2018 05:06
Last Modified: 10 Mar 2019 07:27

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