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ABSTRACT 
Background and objectives: Lactic acid bacteria (LAB) are potential candidates for the mucosal vaccine. Staphylococcal enterotoxin B (SEB), as a potent superantigen exotoxin is associated with widespread dietary poisoning and induction of toxic shock syndrome. Also, cholera toxin is the most important virulence factor in Vibrio cholera pathogenicity. CTB, a well-known immune adjuvant, enhances immunity and is mainly used to produce recombinant vaccines as antigen immunization enhancers. This study aimed to produce recombinant Lactobacillus Plantarum as a candidate vaccine against Vibrio cholera producing Cholera toxin and Staphylococcus aureus producing enterotoxin SEB. Methods:  A gene sequence encoding  SEB, devoid of superantigenic activity, and CTB were successfully designed, synthesized, cloned, and then expressed in a secreted form in the Lactobacillus Plantarum. The recombinant protein containing His-Tag was purified by Ni-NTA Agarose ion-exchange chromatography column.  The purified protein was confirmed by Western blotting. Results: The result of this study demonstrated the expression of this recombinant protein in the Lactobacillus Plantarum system by pnz7021 expression vector. The protein electrophoresis showed that the molecular weight of recombinant fusion protein was 52 kDa. Western blot analysis also confirmed the production of recombinant protein. The use of recombinant vaccines has received a great deal of attention today. LP-pnz7021–SP-rseb-ctxB can be used as a suitable candidate in recombinant vaccines against Vibrio cholera producing Cholera toxin and Staphylococcus aureus producing enterotoxin SEB.
 

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ABSTRACT
Background: The emergence of multi-drug resistant organisms has limited the choice of therapeutic options to treat infections. The lack of development of new antimicrobials paved the way for considering the reassessment of older antibiotics like fosfomycin. In this context, we assessed the in-vitro effect of fosfomycin against carbapenem- resistant Enterobacterales and methicillin-resistant Staphylococcus aureus on bloodstream isolates by agar dilution, disk diffusion and screen agar.
Material & Methods: All the 141 consecutive blood isolates which were resistant to carbapenem and 62 MRSA blood culture isolates were collected over a period of 8 months. The methods such as fosfomycin agar dilution (0.25 µg/ml to 512 µg/ml) , Kirby-Bauer disk diffusion (150μg of fosfomycin + 50μg of glucose -6-phosphate) and fosfomycin screen agar (32 µg/ml, 48µg/ml & 64µg/ml) were performed. All the three methods are interpreted using EUCAST guidelines. The agreement between the new method and the reference method was calculated.
Results: Among the tested isolates, 100 % of MRSA followed by E. coli (86.4%), K.pneumoniae (65.2%) and E.cloacae (50%) were susceptible to fosfomycin. The MIC50 and MIC90 of fosfomycin was 0.5µg/ml and 2µg/ml for MRSA, 16µg/ml and 32µg/ml for K.pneumoniae, 4µg/ml and 16µg/ml for E.coli, 8µg/ml and 32µg/ml for E.cloacae respectively.
Conclusion: In this study, we observed that fosfomycin has a good in-vitro effect on most of the carbapenem resistant Enterobacterales and MRSA isolates tested.
Key words: Fosfomycin; susceptibility testing; antibiotic resistance; MRSA; carbapenem resistant Enterobacterales; MIC
Short running title: In vitro fosfomycin susceptibility