ABSTRACT
This study was conducted to detect the presence of sefA gene among Salmonella Enteritidis isolates from poultry sources by polymerase chain reaction [PCR] and evaluate its potential as diagnostic and epidemiological tools. Thirty Salmonella isolates from poultry sources: broilers, broiler breeders, layers, hatcheries, and poultry abattoirs were investigated. Upper and forward primers were constructed based on the published sequence of the sefA gene that encodes the SEF14 fimbrial subunit [fimbrin]. The size of target product was 526 bp. To confirm the specificity, the PCR products were digested with BamHI restriction enzyme that divides the product to two segments of 186 and 340 bp. The PCR reaction was set up as described in the previous literature. All Salmonella Enteritidis isolates showed the presence of 526 bp product. None of isolates belonging to serogroups B and C were positive for the 526 bp fragment. The restriction enzyme BamHl divided each 526 bp product into two fragments of 186 and 340 bp. This pattern was demonstrated for all Salmonella Enteritidis isolates. The results of the present study showed that the sefA gene carries a high potential to be used as a diagnostic and an epidemiological tool for Salmonella Enteritidis
Subject(s)
Animals , Fimbriae Proteins , Poultry , Polymerase Chain Reaction , Antigens, Bacterial , Pili, SexABSTRACT
A total of 40 NZW rabbits were selected for this study to see the effect of onion extract on immune response following antigenic challenge. These animals were randomly divided into four groups, each composed of ten rabbits. Group I and II were challenged with typhoid H (TH) antigen and groups III and IV with sheep red blood cells (SRBC). Groups I and III were considered as control and II and IV as treated groups. The latter two groups were treated with onion extract orally. The immunosuppressive effect of onion extract was evaluated by estimating antibody levels by Widal test and hemolysin titer. It was found that mean antibody titers were significantly lower in the treated groups than in controls. The weights of thymus and lymph nodes were higher and of adrenal glands were lower in the control groups than in the treated groups. It appeared from the current study that onion extract has an inhibitory effect on immune response.
Subject(s)
Administration, Oral , Adrenal Glands/pathology , Allium , Animals , Antibodies, Bacterial/biosynthesis , Antibody Formation/drug effects , Antigens/immunology , Antigens, Bacterial/immunology , Erythrocytes/immunology , Female , Immunosuppressive Agents/administration & dosage , Lymph Nodes/pathology , Male , Organ Size , Pili, Sex/immunology , Plant Extracts/administration & dosage , Rabbits , Random Allocation , Salmonella typhi/immunology , Sheep , Thymus Gland/pathologyABSTRACT
Specific antisera for colonization factor antigens (CFA/I and CFA/II) were adsorbed to Staphylococcus aureus Cowan I strain, ATCC 12598 to make coagglutination (CoA) reagents for detection of CFAs in enterotoxigenic Esch. coli (ETEC) isolates. Among 1782 strains of Esch. coli isolated from patients with acute diarrhoea, 238 (13.4%) strains exhibited CFA expression. Most prevalent CFA/I positive serogroups were 015, 0148, 0153, 020, 0128, 0114 and 078. CFA/II was detected among isolates of serogroup 080, 085, 06 and 08. Ten ETEC isolates each of serogroups 04, 07, 061, 068, 0117 and 0158 did not show presence of CFA/I or CFA/II. CoA technique proved an appropriate, rapid diagnostic tool which can be used for screening large number of Esch. coli isolates in epidemiological studies.