RESUMEN
The presence of Salmonella Enteritidis in poultry houses after cleaning and disinfection can pose a potential risk to public health, as Salmonella remains one of the most important causes of foodborne diseases. This study focused on ten German layer farms (including floor-reared and free-range systems) with a recent history of Salmonella Enteritidis, and samples were collected from July 2018 to March 2021 after the cleaning and disinfection process. A total of 244 swab samples were tested for the presence of Salmonella using real-time PCR, followed by a culture of positive samples. Results revealed that 61 out of the 244 swab samples tested positive for Salmonella, indicating a prevalence of 25% in the samples examined. Among the Salmonella-positive swab samples identified with the PCR assay, 65.6% (40 out of 61) were confirmed by the culture. Of the 40 isolates obtained from the culture, 36 were identified as Salmonella Enteritidis, while 4 were categorized as rough Salmonella strains. This study emphasizes the importance of both the surrounding area of the poultry houses in terms of infection carry-over and the meticulous implementation of cleaning and disinfection procedures to eliminate any remaining infection within the houses. To mitigate the risk of further Salmonella spread on layer farms, additional investigations are recommended to focus on the existing transmission pathways of Salmonella and their genetic diversity.
RESUMEN
Broiler meat is the predominant source of Salmonella as a foodborne pathogen. Several control strategies have focused on the reduction of Salmonella spp. levels at different production stages. However, the persistence of Salmonella between consecutive flocks is still of great concern. This study was designed to understand the cause of reinfection in broiler flocks due to survival of Salmonella in feeding lines of related matrices. Salmonella (S.) Enteritidis, S. Infantis, and S. Typhimurium isolated from broiler farms in North-West Germany were used. Four types of matrices (phosphate buffer saline (PBS), dietary plant fat, fat with feed mixture, and feed) were applied to evaluate Salmonella survival (with the initial dose about 8.0 log10 CFU/mL) during a simulation of 4 production cycles. To evaluate the growth and survival status of Salmonella ISO 6579-1:2017 were performed (quantitatively by plate count method (PCM) and most probable number method (MPN)) and qualitatively) at 5 defined time points (-7, 0, 4, 7, and 35 d). In all matrices and for the 3 serovars, the Salmonella count decreased at the end of the fourth cycle in comparison to the beginning of the experimental infection, and was still cultivated except for fat matrix. The PBS matrices showed the highest survival level of Salmonella and did not decline drastically by the end of the fourth cycle (5.93 ± 0.00, 5.87 ± 0.02, 5.73 ± 0.05 log10 CFU/mL, respectively). However, the fat matrices showed the lowest survival level for the 3 isolates at d 35 since the first cycle (0 log10 CFU/mL using PCM). Regarding the fat-feed mixture, and feed matrices, there was a fluctuation in the survival rate of Salmonella (all serovars) within each cycle. For the qualitative method, the 3 serovars persisted in all matrices until the end of the fourth cycle except for fat matrices. The present study highlights the ability of Salmonella to survive for a long time in different temperatures and matrices despite efficient cleaning and disinfection processes in the feeding lines, which may influence reinfection with Salmonella in poultry houses.
Asunto(s)
Enfermedades de las Aves de Corral , Salmonelosis Animal , Salmonella enterica , Animales , Pollos , Serogrupo , Reinfección/veterinaria , Salmonella , Salmonelosis Animal/prevención & controlRESUMEN
Minimizing the clinical signs of Enterococcus cecorum infections causing enterococcal spondylitis in broiler herds is successful when initiated as metaphylaxis in the first week of life. Mechanistically, either the Enterococcus species present at that time are reduced by antibiotic treatment or antibiotic treatment might induce changes in intestinal microbiota composition with an indirect and subsequent influence. The aim of the present study was to examine the cecal microbiota of chickens after administering lincospectin or different additives to evaluate whether these additives have lincospectin-like effects on microbiota. Therefore, 157,400 broiler chickens were reared in four chicken houses (~40,000 birds each) on a broiler farm with history of enterococcal spondylitis. Each flock was treated either with lincospectin or water soluble esterified butyrins, Bacillus (B.) licheniformis or palm oil was added via drinking water during the first days of life. Ten birds per house were dissected at days 11, 20 and 33 of life and cecal microbiota were analyzed (16S rRNA gene sequencing). Lincospectin treatment elicited significant changes in the cecal microbiota composition until slaughter age. Among the tested additives, effects of B. licheniformis on cecal microbiota composition were most similar to those seen after the treatment with lincospectin at day 11.
RESUMEN
This report deals with an enzootic due to Salmonella Typhimurium in two free living Eurasian siskins (Spinus spinus Linnaeus, 1758). Other birds in the vicinity of the siskins were not affected. Clinical signs consisted of non-specific symptoms such as ruffled plumage, apathy and reduced food intake. During necropsy, gross lesions were enlarged livers with focal necrosis, pale spleens, enlarged kidneys, pneumonia and enteritis. Salmonella Typhimurium was isolated from internal organs in pure culture. Using the polymerase chain reaction, the detection of Salmonella according to EN ISO 6579:2002 was confirmed. The detailed characterisation of both isolates in the Federal Institute for Risk Assessment and in the Robert Koch Institute yielded for the first siskin Salmonella Typhimurium, 4, 5, 12: i : 1, 2, LT DT104, BT a and for the second siskin Salmonella Typhimurium, 4,12 i : 1, 2, LT DT013, BT c. These phage types were identified for the first time in siskins. The detected phage types have importance as causes of disease not only for free living siskins but also as infectious and zoonotic agents for domestic poultry and poultry products.
