Production and evaluation of anti-salmonella typhimuruim immunoglobulin Y isolated from serum and eggs laid

The purpose of the study was to evaluate the production of antibodies in serum as well as egg yolk raised against S. typhimurium and the cross-reactivity of this antibody with other enteric bacteria. White egg-laying hens were immunized with S. typhimurium, heat-killed whole cell, in Freund's adjuvant. Immunization was done with 107 conlony forming unit [CFU] of bacteria per hen which was injected into the breast muscle of lay. Specific antibodies were detected by enzyme-linked immunosorbent assay in the serum and in eggs. The serum and eggs of two adults white Leghorn hens were not immunized with S. typhimurium used as a control. Chicken egg yolk antibodies [IgY] were raised against S. typhimuruim in the serum as well as in eggs. The production of IgY in serum was higher than IgY produced in egg yolk. Anti-S. typhimurium IgY cross-reacted 63%, 25% and 14% with S. typhimurium, Shigella dysenteriae and E. coli respectively. The findings indicate that eggs from hens immunized with S. typhimuruim have not specific antibodies for the detection of S. typhimuruim, but they may have the potential of being a useful source of passive immunity against this pathogen

Detection of salmonella typhi based on the ViaB sequence by polymerase chain reaction

Background and Purpose: Typhoid fever, a disease caused by Salmonella typhi, is still one of the most important infectious diseases across the world. Different methods such as biochemical and Elisa methods are used for detection of this bacterium, which produce false responses in addition to being time-consuming and expensive. Therefore, the present research was conducted to detect Salmonella typhi by PCR method which is rapid, inexpensive and specific

Materials and methods: In this descriptive study which was conducted via diagnostic method, polymerase chain reaction [PCR] assay was developed for detection of Salmonella typhi. This strain had formerly been confirmed by biochemical methods. For detection by PCR, one primer pair was designed, being specific to ViaB gene. The PCR product was digested by restricted enzyme. For specificity of assay, 6 different strains were used as control negative and for sensitivity of PCR reaction, serial dilution of bacteria was used

Results: The PCR product of Salmonella typhi was 530 bp which were then confirmed by digestion enzymes. In testing the specificity of the assay, Salmonella typhimorium, Shigella flexneri, E. coli, Clostridium botulinum, Staphylococcus aureus and Bacillus subtilis were used as negative control, and did not yield a PCR product. The sensitivity of this method was estimated to be about 50 CFU/ml

Conclusion: The results of this study suggest that detection of ViaB gene with PCR method can be used for diagnossis of Salmonella typhi in clinical samples as a rapid, inexpensive, specific and highly sensitive method

[Identification and antibiotic sensitivity of bacterial isolates in faeces of healthy and diarrhoeic dogs in Shiraz]

In this study 77 and 86 bacterial strains were isolated from faeces of healthy and diarrhoeic dogs respectively. All Salmonella isolates were confirmed by PCR method using specific invA genes. Antibacterial activity of 8 routine antibiotics including tylosin, gentamycin, kanamycin, neomycin, tetracycline, oxy tetracycline, chloramphenicol and sulfadiazine on the isolated bacteria was evaluated by disk diffusion method. Isolated bacteria from faeces of healthy dogs were as follow: Escherichia coli [27.27%], Proteus mirabilis [23.38%], Lactobacilli [19.48%], Pseudomonas aeruginosa [11.69%], Staphylococcus aureus [5.19%], Bacillus cereus [4.49%], Corynebacteria [3.90%], and Clostridium perfringens [2.60%]. Isolated bacteria from faeces of diarrheic dogs were as follows: Escherichia coli [25.58%], Proteus mirabilis [22.09%], Lactobacilli [13.95%], Bacillus cereus [11.63%], Staphylococcus aureus [8.14%], Salmonella [8.14%], Corynebacteria [4.65%], Pseudomonas aeruginosa [4.65%], and Clostridium perfringens [1.16%]. The results showed that all isolated bacteria from diarrheal faeces were sensitive to sulfadiazine. However this antibiotic had weak antibacterial activity against gastrointestinal normal flora