Salmonellosis is a significant public health concern around the world. The injudicious use of antimicrobial agents in poultry production for treatment, growth promotion and prophylaxis has resulted in the emergence of drug resistant strains of Salmonella. The current study was conducted to investigate the prevalence of virulence and antimicrobial resistance genes from Salmonella isolated from South African and Brazilian broiler chickens as well as human clinical isolates. Out of a total of 200 chicken samples that were collected from South Africa 102 (51%) tested positive for Salmonella using the InvA gene. Of the overall 146 Salmonella positive samples that were screened for the iroB gene most of them were confirmed to be Salmonella enterica with the following prevalence rates: 85% of human clinical samples, 68.6% of South African chicken isolates and 70.8% of Brazilian chicken samples. All Salmonella isolates obtained were subjected to antimicrobial susceptibility testing with 10 antibiotics. Salmonella isolates from South African chickens exhibited resistance to almost all antimicrobial agents used, such as tetracycline (93%), trimethoprim-sulfamthoxazole (84%), trimethoprim (78.4%), kanamycin (74%), gentamicin (48%), ampicillin (47%), amoxicillin (31%), chloramphenicol (31%), erythromycin (18%) and streptomycin (12%). All samples were further subjected to PCR in order to screen some common antimicrobial and virulence genes of interest namely spiC, pipD, misL, orfL, pse-1, tet A, tet B, ant (3")-la, sul 1 and sul. All Salmonella positive isolates exhibited resistance to at least one antimicrobial agent; however, antimicrobial resistance patterns demonstrated that multiple drug resistance was prevalent. The findings provide evidence that broiler chickens are colonised by pathogenic Salmonella harbouring antimicrobial resistance genes. Therefore, it is evident that there is a need for prudent use of antimicrobial agents in poultry production systems in order to mitigate the proliferation of multiple drug resistance across species. Keywords: Salmonella; antimicrobial resistance; chicken; human; susceptibility; virulence gene

In this study, the prevalence of Theileria and Babesia species in sheep was assessed with Giemsastained blood smear examination and polymerase chain reaction to identify the different piroplasms in 270 sheep from three Tunisian bioclimatic zones (north, centre, and south). The overall infection prevalence by Babesia spp. and Theileria spp. in Giemsa-stained blood smears was 2.9% (8/270) and 4.8% (13/270) respectively. The molecular results showed that sheep were more often infected by Theileria ovis than Babesia ovis with an overall prevalence of 16.3% (44/270) and 7.8% (21/270) respectively (p = 0.01). The molecular prevalence by Babesia ovis was significantly higher in females than in males (p < 0.05). According to localities B. ovis was found exclusively in sheep from the centre of Tunisia (Kairouan) whereas Theileria ovis was found in all regions. Infections with T. ovis and B. ovis were confirmed by sequencing. The sequence of T. ovis in this study (accession numbers KM924442) falls into the same clade as T. ovis deposited in GenBank. The T. ovis amplicons (KM924442) showed 99%–100% identities with GenBank sequences. Moreover, comparison of the partial sequences of 18S rRNA gene of B. ovis described in this study (KP670199) revealed 99.4% similarity with B. ovis recently reported in northern Tunisia from sheep and goats. Three nucleotides were different at positions 73 (A/T), 417 (A/T), and 420 (G/T). It also had 99% identity with B. ovis from Spain, Turkey and Iraq. The results suggest a high T. ovis prevalence in Tunisia with a decreasing north-south gradient. This could be correlated to the vector tick distribution.

Corynebacterium pseudotuberculosis vaccine was prepared from a local field isolate. Vaccination of sheep with 50g PLD toxoid and 10 mg bacterin adjuvanted with Montanide oil improved the levels of immune responses of sheep. In many countries, inactivated C. pseudotuberculosis adjuvant vaccines have been used for prevention and control of caseous lymphadenitis in sheep. However, the efficacy was variable. The aim of the present study was directed to prepare and evaluate the potency of an inactivated C. pseudotuberculosis vaccine using Montanide ISA206. Sheep were vaccinated with 1st dose of 2ml containing 10 mg bacterin and 50g toxoid and Montanide ISA 206 oil adjuvant and boostered with the same dose 15 days Apart. Evaluation of post vaccinal cellular immune response with lymphocyte proliferation assay and humoral immune response using ELISA was carried out. Cell mediated immune response of vaccinated sheep reached its peak 0.445 by 1st week post the second vaccination. The level of humoral immune response showed optical density of 1.005 by 1st week post the second vaccination. Challenge test was done in all sheep four weeks after the second dose of vaccination. Three sheep from vaccinated and three sheep from non-vaccinated groups were slaughtered and necropsied 150 days post challenge. The results revealed 75% protection percentage against challenge while unvaccinated challenged sheep showed 9% protection. Statistical analysis indicated that the vaccine assessed a significant level of cellular and humoral immunity.

A total of 120 fish samples were collected from different water sources in El Fayoum Governorate, (Bahr El Banat agricultural drainage, different fish farms and Al Rayaan Lake). and represented by Clarias gariepinus from Bahr El Banat agricultural drainage, different fish farms (15 each), Mugil cephalus from different fish farms and Al Rayaan Lake (15 each), Solea solea (30 samples) and Oreochromis niloticus from Bahr El Banat agricultural drainage, different fish farms and Al Rayaan Lake (10 each). Fourteen organochlorine compounds were analyzed by gas chromatography. Fish samples from Bahr El Banat revealed the highest mean levels of p,p'-DDD, endrin, endosulfan, γ-chlordane, heptachlor and γ-HCH, while fish samples from Al Rayaan Lake have shown the highest mean level of methoxychlor, p,p'-DDT, p,p'- DDE, dieldrin, heptachlor epoxide, δ-HCH and α-HCH. Most of the examined fish samples from different species, are within the maximum residue limits and should not pose a health risk to consumers. The public health hazards were discussed as well as recommendations were done.

The pharmacokinetic aspects of tulathromycin (2.5 mg/kg b.w.) were studied following intravenous administration alone and in combination with flunixin meglumine (2.2 mg/kg b.w) in apparently healthy goats. Tulathromycin concentrations in serum were determined by microbiological assay technique using Bacillus subtiles (ATCC 66343) as test organism. The half-lives of distribution and elimination (t0.5(a)and to.5(p)) were 0.071, 0.046 and 6.43, and 5.05 h. following intravenous injection of tulathromycin alone and in combination with flunixin, respectively. Volume of distribution at steady state (Vdss) was 0.249 and 0.96l/kg., mean residence time (MRT) was 6.27 and 5.99 h and total body clearance (ClB) was 0.046 and 0.17 l/kg/hr., respectively. It was concluded that flunixin significantly altered the pharmacokinetics of tulathromycin by increase its distribution and accelerate its elimination from body. Therefore care should be taken during use of tulathromycin in goats concurrently with flunixin.

The present study was carried out on 22 cows suffering from ruminal impaction with plastic materials as foreign bodies and ten apparently healthy cows as a control group. Clinical examination included clinical signs, temperature, pulse, respiratory rate and ruminal motility were recorded prior to treatment. Hematological parameters such as hemoglobin (Hb), packed cell volume (PCV), erythrocyte count (RBCs), total leucocytes (WBCs) count and the glutaraldehyde test were performed. Ruminal fluid was evaluated for pH and the methylene blue reduction time (MBRT). The mean pH of rumen fluid, MBRT, total leucocytes count, and PCV were increased significantly (P<0.05). Rumen motility was significantly reduced (P<0.05) preoperative in the animals suffering from rumen impaction, but the mean value of pulse rate, respiration rate, temperature, glutaraldehyde test, haemoglobin and total erythrocyte count were non-significantly changed. On the 5th postoperative day the clinical and the laboratory parameters in the study group had largely become normalized. Six months after the procedure, 18 (81.9%) cows showed complete recovery and 4 (18.9%) animals were slaughtered within 3 months following surgery. This study concluded that the clinical and laboratory findings might be of diagnostic importance. Rumen impaction with plastic materials should be differentiated from anorexia, emaciation, ruminal hypomotility, tympany and dehydration in cows. The surgical removal of foreign body demonstrated positive effects on animal health.

Little is known about latent infection and molecular characterisation of Neospora caninum in sheep (Ovis aries). In this study, 330 sheep samples (180 hearts and 150 brains) were analysed for N. caninum DNA by nested polymerase chain reaction (PCR) targeting the Nc-5 gene. Neospora caninum DNA was detected in 3.9% (13/330) of sheep samples. The parasite’s DNA was detected in 6.7% of heart samples (12/180) and 0.7% (1/150) of brain samples. No clinical signs were recorded from infected or uninfected animals. Sequencing of the genomic DNA revealed 96% – 99% similarity with each other and 95.15% – 100% similarity with N. caninum sequences deposited in GenBank. To our knowledge, this is the first report on the use of PCR to identify latent neosporosis in sheep in Iran. The results of this study have the potential to contribute to our understanding of the role of N. caninum-infected sheep in the epidemiology of neosporosis.