Chicken Salmonella enterica serovars are enteric bacteria associated with massive public health risks and economic losses. There is a widespread antimicrobial resistance among S. enterica serotypes, and innovative solutions to antibiotic resistance are needed. We aimed to use probiotics to reduce antibiotic resistance and identify the major probiotic players that modify the early interactions between S. enterica and host cells. One-day-old cobb broiler chicks were challenged with S. typhimurium after oral inoculation with different probiotic strains for 3 days. The adherence of different probiotic strains to Caco-2 intestinal epithelial cells was studied in vitro. Lactobacillus (Lacticaseibacillus) casei ATTC334 and Bifidobacterium breve JCM1192 strains attached to Caco-2 cells stronger than B. infantis BL2416. L. casei ATTC334 and B. breve JCM1192 reduced S. typhimurium recovery from the cecal tonsils by competitive exclusion mechanism. Although B. infantis BL2416 bound poorly to Caco-2 epithelial cells, it reduced S. typhimurium recovery and increased IFN-γ and TNF-α production. L. casei ATTC334, B. breve JCM1192 and B. infantis BL2416 improved body weight gain and the food conversion rate in S. typhimurium-infected broilers. B. longum Ncc2785 neither attached to epithelial cells nor induced IFN-γ and TNF-α release and consequently did not prevent S. typhimurium colonization in broiler chickens. In conclusion, probiotics prevented the intestinal colonization of S. typhimurium in infected chickens by competitive exclusion or cytokine production mechanisms.

BackgroundAspergillus sojae has been an important filamentous fungus in Biotechnology due to its use in diverse fermentative processes for the production of various food products. Furthermore, this fungus is a common expression system for the production of enzymes and other metabolites. The availability of molecular genetic tools to explore its biology is thus of big interest. In this study, an Agrobacterium tumefaciens-mediated transformation (ATMT) system for A. sojae was developed and its applicability evaluated.ResultsThe donor plasmid named pRM-eGFP was constructed for ATMT of A. sojae. This plasmid contains the ble and egfp genes in its transfer DNA element (T-DNA) to confer phleomycin resistance and express the enhanced green fluorescent protein (EGFP) in A. sojae, respectively. Agrobacterium tumefaciens (LBA4404) harboring the donor plasmid and A. sojae (ATCC 20235) were co-cultured under diverse conditions to achieve ATMT. The maximum number of transformed fungi was obtained after three days of co-culturing at 28°C, and selection with 50 μg/ml phleomycin. Polymerase chain reaction (PCR), fluorescence microscopy and Western Blot analysis for EGFP expression confirmed successful genomic integration of the T-DNA element in A. sojae. The T-DNA was mitotically stable in approximately 40% of the fungal transformants after four generations of sub-culturing under phleomycin pressure.ConclusionWe successfully established a new ATMT protocol for A. sojae. This transformation system should enable further protein expression studies on this filamentous fungus.

A total of (236 swabs) fecal samples from El-Menofiya and El-Kalubia Governorates, as sporadic cases of were subjected to bacteriological, biochemical, serotyping, sensitivity testing and PCR detection of resistance genes for β-Lactames and Quinolones. Ten isolates of Salmonella species were identified, as 7 isolates (4.7%) from calves (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella saintpaul, Salmonella Langeveld and Salmonella Havana), 2 isolates (3.6%) from lambs (Salmonella Typhimurium, Salmonella Bardo) and one isolate (3.3%) from goat-kids (Salmonella Enteritidis) Salmonella isolates sensitivity to β-lacatmes was 0.00% for ampicillin, penicillin G, piperacillin, cephalexin, cefoxitin, ampicillin-sulbactam, ceftazidime, 10% for ceftriaxone and 20% for amoxicillinclavulanic acid, increased to 60% and 100% for aztreonam, imipenem respectively. Susceptibility of isolates to quinolones were 10% for ciprofluxacin, 20% to nalidixic acid, and 100% for each of norfloxacin and levofloxacin. PCR study showed beta-lactamase encoding gene, bla (TEM-1), was identified in 90% and the extended-spectrum beta-lactamase, (CIT) in 20% while bla (SHV) and acc in 80% of isolates. The detection was 50%, 40%, and 0.00% for FOX, MOX, and bla (OXA-1) genes, respectively. Plasmid-mediated quinolone resistance, qnrB, qnrS were detected in 80% while aac(6')-Ib-cr, was only in 50% of the isolates. Results showed a high incidence of β-lacatmase than quinolones resistance genes and higher isolate susceptibility to quinolone than to β-lacatmes which indicates higher efficacy and validity of quinolones. Results indicates quinolones LEV and NOR in addition to βlacatmes imipenem are the drugs of choice for suspected salmonella cases.

Ten isolates of Salmonella species were obtained from sporadic cases of profuse diarrhea in new born ruminants from El-Menofiya and El-Kalubia Governorates in Egypt. These isolates were as follow 7 isolates from calves (Salmonella Typhimurium, Salmonella Enteritidis,two were Salmonella Saintpaul, two were Salmonella Langeveld and Salmonella Havana) ,two isolates from lambs (Salmonella Typhimurium, Salmonella Bardo) and one isolate from goat-kids(Salmonella Enteritidis). Salmonella isolates resistance to aminoglycosoides was 0.00% for Amikacin, 30% for tobramycin and 50% for streptomycin. Susceptibility of isolates to tetracycline was 50% for doxycycline. Results showed a high incidence of aminoglycosoides resistance gene aadB in 100% of the isolates while aadA2 genes in 40% of the isolates. Incidence of tetracycline resistance genes was 0.00% for tetA(B) and 80% for tetA(A). The difference between the results of this study and those from other regions in Egypt necessitate a complete survey overall the country to make a complete and clear map of salmonella servoars, their antibiotics susceptibility and in molecular characterization of resistance determinants in each region.

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