Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 108 CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.

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The present study was done to investigate the wide spread resistance to some antimicrobial groups among Salmonellae isolated from replacement and layer flocks in Egypt. A total of 24 salmonellae were isolated from 200 birds (apparently healthy or diseased suffered from diarrhea, dehydration, respiratory distress and decrease of egg production) and serotyped into S. Enteritidis, S. Typhimurium, S. Kentucky and S. Newport. Twenty-one Salmonella isolates were examined for resistance genes against different antimicrobials. The resistance pattern of all Salmonella isolates was done using antibiogram, the resistant isolates were examined for the presence of resistance coding genes using PCR technique. The investigated resistance genes were (qnrS, aac (6')-ib-cr) for quinolone resistant isolates, blaTEM for β-lactam resistant isolates, aadA1 and aadA2 for aminoglycosides resistant isolates and tetA(A) and tetA(B) for tetracycline resistant isolates. Resistant genes percentages for tetA(A), tetA(B), blaTEM, aadA1, aadA2, aac (6')-ib-cr and qnrS in the examined isolates were 70%, 20%, 93.3%, 30%, 80%, 10% and 15%, respectively. In conclusion, at the study area, antimicrobial resistance genes are widely spread in Salmonella isolates. Thus, minimizing the influence of antibiotics in treatment and prevention.

In this study, we determined the prevalence and toxin types of antibiotic-resistant Clostridium perfringens in chicken, pigeons, camels, and humans. We investigated the inhibitory effects of AgNPs on biofilm formation ability of the isolates and the genetic relatedness of the isolates from various sources determined using RAPD-PCR. Fifty isolates were identified using PCR, and all the isolates were of type A. The cpe and cpb2 genes were detected in 12% and 56% of the isolates, respectively. The effect of AgNPs on biofilm production of six representative isolates indicated that at the highest concentration of AgNPs (100 µg/mL), the inhibition percentages were 80.8–82.8%. The RAPD-PCR patterns of the 50 C. perfringens isolates from various sources revealed 33 profiles and four clusters, and the discriminatory power of RAPD-PCR was high. Multidrug-resistant C. perfringens isolates are predominant in the study area. The inhibition of biofilm formation by C. perfringens isolates was dose-dependent, and RAPD-PCR is a promising method for studying the genetic relatedness between the isolates from various sources. This is the first report of AgNPs’ anti-biofilm activity against C. perfringens from chickens, pigeons, camels, and humans, to the best of our knowledge.

IBH is associated with fowl aviadenoviruses (FAdVs), which are non-enveloped double stranded DNA viruses with icosahedral symmetry (Zhao et al., 2015; Mase et al., 2009). The virus DNA is associated with many proteins (Ginsberg, 2013), the main proteins are hexon (II) and fibre (IV) with a penton base (III) non-covalently attached, and numerous minor proteins: VI, VIII, IX, IIIa and IVa2 (Russell, 2000).The existing classification scheme identifies five types of fowl aviadenoviruses A to E (FAdV-A to FAdV-E) on mo research Article Abstract | During the last 10 years, many inclusion body hepatitis (IBH) outbreaks across Egypt were reported causing high economic losses to poultry industry. The current study aimed the detection and molecular characterization of IBH in broilers at Sharkia governorate. For identification and genotyping of fowl adenoviruses related to IBH in broiler flocks, liver samples representing 40 broiler flocks were collected and tested for FAdVs based on hexon gene detection using polymerase chain reaction (PCR). We recorded most loses among broilers at 3-5 weeks of age. Only depression, ruffled feather were the observed signs with varied mortality (8-14%). On necropsy, liver was yellowish, friable, enlarged and hemorrhagic. For identification and genotyping of Fowl adenoviruses related to inclusion body hepatitis (IBH) in broiler flocks at Sharkia governorate, liver samples representing 40 broiler flocks were collected and tested for FAdVs based on hexon gene detection using polymerase chain reaction (PCR Out of the forty examined broiler flocks, three flocks (7.5%) were recorded PCR positive for Aviadenoviruses. Based on hexon loop-1 gene analysis, the nucleotide sequence identity of the three positive samples (EG101/2018, EG102/2018 and EG103/2018) was >97.7% and genetically was closer to reference strains serotype 2 (FAdV-2), the three examined strains shared a high degree of nucleotide identity (97.6-99.6%). Using neighbor joining for the phylogenetic tree construction depending on hexon gene nucleotides and amino acids sequences, our strains were clustered in the same clade with FAdV type D. This study help to extend the current knowledge about the currently circulating IBH viruses and to develop vaccination and control strategy.

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