The Detection of Salmonella Enteritidis on German Layer Farms after Cleaning and Disinfection.

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.

Survival persistence of the 3 common Salmonella enterica serotypes isolated from broilers' in different matrices.

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.

Correction to: Unexpected high frequency of neurofibroma in the celiac ganglion of German cattle.

An amendment to this paper has been published and can be accessed via the original article.

Unexpected high frequency of neurofibroma in the celiac ganglion of German cattle.

In a study originally designed to find potential risk factors for bovine spongiform encephalopathy (BSE) we examined tissues from 403 Holstein Frisian cattle in total. These included 20 BSE cattle and their 236 birth- and feeding cohort animals plus 32 offspring, 103 age, breed and district-matched control cattle and further twelve cattle with neurological signs. In addition to the obex, we examined the celiac ganglion, cervical cranial ganglion, trigeminal ganglion and proximal ganglion of the vagus nerve using histological techniques. Unexpectedly, we found a high number of neurofibroma, a benign peripheral nerve sheath tumor consisting of Schwann cells, fibroblasts and perineural cells. The neurofibroma were present only in the celiac ganglion and found during histologic examination. With a frequency of 9.91% in BSE cattle and their cohorts (case animals) and 9.09% in the age, breed and district matched control animals there seems to be no correlation between the occurrence of BSE and neurofibroma. Benign peripheral nerve sheath tumors have been described more often in cattle than in other domestic animals. Usually, they are incidental macroscopic findings in the thoracic ganglia during meat inspection. To our knowledge, there are no previous systematic histologic studies including bovine celiac ganglia at all. The high incidence of celiac ganglia neurofibroma may play a role in the frequently occurring abomasal displacements in Holstein Frisian cattle as the tumors might cause a gastrointestinal motility disorder. At present a genetic predisposition for these neoplasms cannot be ruled out.

DETECTION OF MYCOBACTERIUM AVIUM SUBSPECIES PARATUBERCULOSIS IN ROCK HYRAXES ( PROCAVIA CAPENSIS) IMPORTED FROM SOUTH AFRICA.

Mycobacterium avium subspecies paratuberculosis (MAP) causes chronic, progressive, and consecutively fatal enteritis, especially in ruminants. MAP distribution among wildlife is not yet clear. In this study, three wild-born rock hyraxes ( Procavia capensis) had been imported from South Africa to a German zoological garden. During the quarantine period, four young animals were born. The wild-born animals showed symptoms of mild diarrhea shortly after their arrival in the zoological garden, but all routine parasitological and bacteriologic tests performed were negative. Therefore, the animals were additionally tested for MAP infection. MAP DNA was detected by seminested PCR (snPCR) in a pooled fecal sample of the seven animals. Subsequent PCR analysis of the individual feces samples confirmed the excretion of MAP in two rock hyraxes (one wild-born and one born in captivity). Sequence analysis of the corresponding 278-bp amplicons revealed 100% homology to the reference MAP-K10 IS900 sequence. No antibody response against MAP was detected in the individual serum samples. MAP-specific postmortem lesions were not observed by gross pathology and histology, neither after death nor after euthanization of the animals. Nevertheless, MAP was detected by snPCR and culture in the gastrointestinal tract, urogenital tract, cardiovascular system, and/or respiratory system of three other animals of the group (one wild-born and two born in captivity). This study is the first report confirming MAP occurrence in rock hyraxes. Therefore, it is recommended that veterinarians and zoo employees consider rock hyraxes as a possible source of MAP infection for domestic livestock in South Africa and the valuable animal stock of zoological facilities.

Detection of Mycobacterium avium subspecies paratuberculosis by IS900-based PCR assays from an alpaca (Vicugna pacos) kept in a German zoological garden.

An alpaca (Vicugna pacos) bred and kept in a German zoological garden exhibited clinical signs consistent with paratuberculosis. The presence of Mycobacterium avium ssp. paratuberculosis (MAP) was confirmed in feces and in the ileocecal lymph node (ILN) by IS900-based polymerase chain reaction (PCR) assays and culture. A bacterial burden of 7.6 x 10(6) MAP/g in feces and 4.4 x 10(7) MAP/g in lymph node tissue was determined by real-time PCR. For further characterization, a conventional PCR was developed. After sequencing of the 864-bp PCR amplicon covering nucleotide positions 13 to 876 within the IS900, the alpaca isolate shared 100% nucleotide homology with the bovine MAP-K10 IS900 reference sequence (GenBank: AE16958), indicating a cattle strain. This report supports the present occurrence of MAP in German camelid populations and highlights the need to expand routine MAP surveillance to South American camelids held in European zoos.

Distribution of Mycobacterium avium ssp. paratuberculosis in a German zoological garden determined by IS900 semi-nested and quantitative real-time PCR.

Little data concerning the distribution of Mycobacterium avium ssp. paratuberculosis (MAP) in zoological gardens is available. The presence of MAP in captured wildlife might provide further information on non-ruminant hosts and expand the list of animals susceptible to MAP being potential sources of MAP transmission. Therefore, a German zoological garden with recent history of clinical paratuberculosis in Barbary sheep (Ammotragus lervia) and an alpaca (Lama pacos) was selected to estimate the distribution of MAP infections in 21 mammalian and avian species. Pooled faecal samples from individual animals of each species were tested for the presence of MAP. A previously developed IS900 semi-nested PCR (snPCR) assay, amplifying a 587 bp and a 278 bp fragment, was used for the detection of MAP-DNA. Based on this snPCR, in 14 out of the 21 pooled faecal samples MAP-DNA was detected. MAP positive snPCR results were observed in ruminants and camelids as well as in non-ruminants such as equines, primates, rodents, and birds. Moreover, a quantitative real-time PCR demonstrated that the concentration of MAP-DNA was within the range of 2.2 × 10(3)-9.6 × 10(6) MAP-DNA equivalents per gram faeces. The highest amount was shed by primates such as Black-and-white ruffed lemurs (Varecia variegata) and Cottontop tamarins (Saguinus oedipus). This is the first survey investigating the presence of MAP in a German zoo, which includes non-ruminants. The results of the present study confirm the wide host range of MAP and demonstrate that MAP occurs more frequently in zoo animals than expected. In order to restrict further spread of MAP in European zoos, additional investigations regarding the existing transmission pathways of MAP in zoos are recommended.

Detection of Mycobacterium avium ssp. paratuberculosis in ileocaecal lymph nodes collected from elderly slaughter cows using a semi-nested IS900 polymerase chain reaction.

The aim of this study was to investigate the occurrence of subclinical Mycobacterium avium spp. paratuberculosis (MAP) infections at slaughter by testing ileocaecal lymph nodes with a semi-nested IS900 PCR. Tissue samples were available within the framework of a parallel study investigating BSE-susceptibility factors in members of BSE-cohorts in the German Federal State of Lower Saxony. Ileocaecal lymph nodes were collected over a 2-year sampling period from 99 slaughter cattle of a mean age of 6.5 years (5.5-7.5 years). A recently developed IS900 semi-nested polymerase chain reaction (snPCR) assay offering a sensitivity of 1 genome equivalent was used for the detection of MAP-DNA. Based on this snPCR, 17 out of the 99 samples gave positive results, indicating a MAP occurrence of 17.17% in the random sample. All PCR products were sequenced for screening of polymorphisms. Nucleotide homologies of 98.5-100% were found with respect to the MAP K10 reference sequence IS900 (GenBank: AE16958). PCR analysis of ileocaecal lymph nodes collected from slaughter cattle proved to be a suitable technique to determine MAP occurrence in the local cattle population.