Fowl Typhoid Outbreak on a Commercial Turkey Farm in Croatia

Fowl typhoid is a septicemic disease caused by Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum. It is a host-specific disease primarily affecting chickens and turkeys, although it has been reported in various animal species and sporadically in humans. Here, we present a case of a fowl typhoid outbreak on a turkey poult farm where the source of infection was the hatchery. The birds started showing symptoms of growth retardation at 21 days of age, after which the mortality rates gradually started to increase. Post mortem examination revealed that the main lesions were granulomatous proliferations in the small intestines. The results of the histopathological examination indicate that the severity of the infection was alleviated by the application of phytogenic mixtures and probiotics as a supportive treatment, even though the affected flock was eventually culled at 60 days of age. The farmer was advised to apply more strict biosecurity measures to prevent the spread of the disease on the farm and try to eradicate the pathogen from the barn. Since the outbreak, there have been no recurrent infections.

One-Step PCR Detection of Salmonella Pullorum/Gallinarum Using a Novel Target: The Flagellar Biosynthesis Gene flhB

Salmonella enterica serovar Pullorum/Gallinarum is an important infectious pathogen that has caused widespread problems for chicken industry. Traditional Salmonella serotyping is an expensive and time-consuming process. In this study, we developed a rapid one-step polymerase chain reaction (PCR) method to identify S. Pullorum/Gallinarum. The PCR-based assay focuses on flhB, which shows a deficient region only in S. Pullorum/Gallinarum, compared with that of other serovars. The specificity and sensitivity of the PCR system were evaluated. The developed PCR method could identify S. Pullorum/Gallinarum from 27 different Salmonella serovars and eight non-Salmonella pathogens. The minimum limit of DNA and the lowest number of cells of S. Pullorum for the PCR detection were no less than 5.85 pg/μL and 10 CFU, respectively. The method was applied to the analysis of Salmonella strains isolated from the chicken farm. The PCR-based testing results of the farm isolates were in concordance with those obtained using traditional serotyping method. This newly developed PCR-based system could be used to accurately screen for the presence of S. Pullorum/Gallinarum, and support traditional serotyping methods, especially in high-throughput screening situations.