Objective: The study of Mycoplasma gallisepticum (MG) infection is needed, not only to understand the disease process but also to understand the interference with the evaluation of some live viral poultry vaccines. This study aims to investigate the titration and potency of some live attenuated poultry viral vaccines; Newcastle disease, infectious bronchitis, infectious bursal disease, and Reo in both specific pathogen-free (SPF) embryonated chicken eggs (ECEs) and chickens.Methods: Titration of live attenuated viral poultry vaccines in ECEs was carried out by dividing the inoculated eggs into four groups; the pre-, simultaneously-, post-, and non-MG contaminated. MG effect on the potency test was carried out using seventeen groups of SPF chickens (25 chicken/ group) placed into separate isolators. Each live attenuated viral poultry vaccine was inoculated into 4 groups. Results:The highest titer of these vaccines that appeared in MG pre-contaminated ECEs were 10 , and 10 6 , respectively. Although the potency of these previous vaccines indicated that the highest antibodies titer that appeared in MG pre-infected vaccinated chickens were 7.5 log 2 , 36 enzyme-linked immunosorbent assay unit (EU), and 42 EU, respectively; the lowest antibodies titer that appeared in non-MG infected vaccinated chickens were 6.5 log 2 , 12 EU, 17 EU, and 10 EU, respectively. Conclusion:The present study findings underline the importance of using Mycoplasma -free eggs or chicken for the production of virus vaccines.

Escherichia coli (E. coli) continue to be one of the major causes of food poisoning in the world. Different methods have been developed in order to reduce the time for the evaluation of the E. coli vaccines. Infectious bronchitis (IB) is a highly contagious viral disease of poultry causes economic losses. Control of IB virus has been attempted using live attenuated and inactivated vaccines. Due to the continuous emergence of E. coli and infections bronchitis, it was important to find a rapid accurate method of evaluation of the used live attenuated E. coli and IB vaccines. In this study, three assays, namely a conventional identification method including; Specific Pathogen Free eggs (SPF) eggs inoculation for IB vaccine and culture method for E. coli vaccine, conventional polymerase chain reaction (PCR) assay and SYBR Green I Real-Time PCR method were developed and evaluated on 10 fold serial dilutions of each vaccine. A comparative analysis of these three assays was then performed, and the results indicated that the SYBR Green I Real-Time PCR had the highest sensitivity and specificity.

Different methods have been developed in order to reduce the time for the evaluation of the E.coli vaccines. Infectious bronchitis (IB) is a highly contagious viral disease of poultry causes economic losses. Control of IB virus has been attempted using live attenuated and inactivated vaccines. Due to the continuous emergence of E.coli and infections bronchitis, it was important to find a rapid accurate method of evaluation of the used live attenuated E.coli and IB vaccines. In this study, three assays, namely a conventional identification methods including; Specific Pathogen Free eggs (SPF) eggs inoculation for IB vaccine and culture method for E.coli vaccine, conventional polymerase chain reaction (PCR) assay and SYBR Green I Real-Time PCR method were developed and evaluated on 10 fold serial dilutions of each vaccine. A comparative analysis of these three assays was then performed, and the results indicated that the SYBR Green I Real-Time PCR had the highest sensitivity and specificity.

I NTENSIVE usage of antibiotics in poultry sectors enabled the consequent emergence of antibiotic resistant bacteria (ARB) and the development of their corresponding antibiotic resistance genes in the environment of human and animal food chains. To determine the antibiotic resistance of MRSA in poultry, 405 different samples (205 broiler farms, 124 backyards, 60 hatchers, and 16 slaughterhouses) were collected from southern Egypt. Identification was carried out by the classical culture methods, and the disc diffusion test was used to determine the antibiotic resistance patterns. Almost, 10% (40/405) of isolated S. aureus was identified as coagulase-positive. While 23% (94/405) was coagulase-negative Staphylococci. As expected, most of S. aureus isolates were susceptible for Vancomycin (95%), sulfamethoxazole trimethoprim (80%), and chloramphenicol (75%). Contrariwise, the high resistance was shown to clindamycin (97.5%), erythromycin (95%), tetracycline (90%), and penicillin and oxacillin (82.5%). MRSA strains were identified as 95% (38/40) of all isolated S. aureus by using a conventional PCR directed to the mec-A gene. This high proportion of MRSA in poultry has a considerable risk to public health. So that, the results of this study highlight the need for control programs that encompass primary animal production and the food chain to alleviate the contamination of MRSA for the poultry industry of Egypt, and consequently for humans.