Deletion of the Viral Thymidine Kinase in a Meq-Deleted Recombinant Marek’s Disease Virus Reduces Lymphoid Atrophy but Is Less Protective

Marek’s disease (MD) is a ubiquitous disease of domesticated chickens and its etiologic agent is the Gallid alphaherpesvirus 2 (GaHV-2), also known as Marek’s disease virus (MDV). MD is currently controlled by vaccination using live attenuated strains of MDV (e.g., CVI988/Rispens), non-pathogenic serotypes of MDV (GaHV-3), or non-pathogenic strains of the related Melagrid alphaherpesvirus 1 (MeHV-1). One attractive strategy for the production of new vaccine strains is a recombinant MDV attenuated by the deletion of the major viral oncogene meq. However, meq-deleted variants of MDV cause atrophy of the bursa and thymus in maternal antibody-negative chickens, and the resulting immunosuppression makes them unsuitable. Herein we detail our attempt to mitigate the lymphoid atrophy caused by meq-deleted MDV by further attenuation of the virus through ablation of the viral thymidine kinase (tk) gene. We demonstrate that ablation of the viral tk from the meq-deleted virus rMd5B40/Δmeq resulted in a virus attenuated for replication in vitro and which spared chickens from atrophy of the lymphoid organs in vivo. When the rMd5B40/Δmeq/Δtk/GFP was used as a vaccine it was protective against challenge with the vv+MDV strain 686, but the protection was less than that provided by the CVI988/Rispens vaccine.

Identification of Salmonella spp. strains in poultry products and their impact on Public Health

Introduction. Poultry meat and eggs represent a risk of contamination with zoonotic bacterial agents. This requires permanent laboratory monitoring throughout the production chain segment. Material and methods. The research material consisted of samples retrieved from poultry carcasses and eggs for current consumption. There were examined 80 samples of eggs and 110 samples of poultry carcasses. Results. S. Gallinarum, S. Enteritidis and S. Infantins serotypes were isolated in 12.7% of samples out of 110 examined carcasses, whereas S. Gallinarum, S. Dublin și S. Typhimurium serotypes were detected in 6.25% of 80 egg samples. Conclusions. Bacteriological research on poultry carcasses and eggs showed the presence of pathogenic serotypes of Salmonella spp., which is a major risk to public health.

Study of the activity and specifity of microseries of Yersinia Enterocolitica sera O3, O5, O6.30, O8, O9 in vitro SAT

Yersiniosis is ubiquitous and causes great damage and death. The genus Yersinia has 11 species, 3 of which are characteristic of human disease: Yersinia pestis, Yersinia enterocolitica and Yersinia pseudotuberculosis. Based on serotyping, this pathogen is classified into more than 57 serogroups. Pathogenic serotypes are O: 3 (biogroup 4), O: 5.27 (biogroup 2 and 3), O: 8 (biogroup 1B) and O: 9 (biogroup 2). The most common serogroups isolated from humans in European countries are O: 3 and then O: 9. In the United States, for example, the more common serogroup O: 8. In general, 11 serovars are most associated with human infections (O: 3, O: 4, O: 5.27, O: 8, O: 9, O: 13, O: 18, O: 20, O: 21). The publication presents data on the activity of two microseries of Yersinia Enterocolitica serovariants O3, O5, O6.30, O8, O9 by serological predictions in the samples of RA. In the process of obtaining and increasing the activity of two microseries of microseries, the methodology of obtaining components in a set, designated for serological diagnostics of tincture in the RA, was developed. The effectiveness of experimental samples of Yersinia sera was studied. Serum Yersinia enterocolitica O3 of microseries 1, O8 of microseries 2 and O9 of both microseries were determined to be highly specific. Yersinia sera of serovar O6.30 microseries 1, as well as O3, O5, O9 of both microseries are active in a titer of not less than 1: 400. It is established that according to this method of obtaining RA components allows to detect specific antibodies in the sera of animals in the titer of 1: 400–1: 800. Due to the antigenic affinity of strains of serotypes O5 and O6.30, there is a need to pay more attention to the selection of Yersinia, in particular to work with antigenically homogeneous clones, which will avoid nonspecific intraspecific cross-reactions, respectively, increase the specificity of sera.

Microbiological quality of seasoned chicken cuts using Escherichia coli and Salmonella spp. as quality indicators.

Enteropathogens such as Salmonella spp. and Escherichia coli are important health challenges in the poultry production chain, because when installed in the production chain, they impair the safety of food supply. The determination of the microbiological quality of chicken meat, especially when marketed in spiced form, is necessary, given that consumer prefer this type of processed protein. This work aims to evaluate the microbiological quality of the meat of seasoned chicken marketed in the municipality of Rio Verde, Goias, using Salmonella spp. and Escherichia coli as target microorganisms, and considering as variables the type of establishment, validity date and presence of municipal inspection seal. From 80 analyzed samples, 30% (24/80) of samples were positive for Salmonella spp. and 55% (44/80) for E. coli. Regarding the type of establishment, it was observed that 27.45% (14/51) of supermarket samples and 34.48% (10/29) of meat store samples were contaminated by Salmonella spp. Considering E. coli, 49.01% (25/51) of supermarket samples and 65.55% (19/29) of meat store samples were positive for this pathogen. 80% (64/80) of the samples had the municipal inspection seal (MIS), and 83.75% (67/80) contained the expiration date on the label. The legislation in its narrative guarantee’s protection for the consumer with regard to the presence of pathogenic serotypes of these agents, however, it is worth noting that the effective action of health surveillance, and the constant laboratory investigation of the products are necessary.

STUDY OF PATHOGENIC FACTORS OF E.COLI ISOLATED FROM PATIENTS WITH PERITONITIS

The aim: To study the biological properties of museum and clinical strains of E.coli isolated from patients with peritonitis. Materials and methods: It was used 94 strains (clinical, museum and reference). The ability of E. coli to adhere was investigated by hemadhezive method to formal human erythrocytes of 0 (I) Rh-positive blood group. The study measured the ability of microorganisms to produce gelatinaze, caseinase, fibrinolysin, hemolysin. To control of the enzyme activity the positive and negative control with reference strains were used. Synchronisation of cultures activity before experiments was achieved by one-time effect of low temperature (+4 С) during 30 minutes. Results: To investigate the pathogenic factors of E. coli we carried out determining of proteolytic, gelatinous, caseinous, fibrinolytic, haemolytic and adhesion properties. Conclusions: In our investigation pathogen icspecies of Esherihies are virtually indistinguishable from representatives of normal microflora on its morphological, biochemical and cultural properties. During investigation of serological properties of selected of E. coli strains (n = 94) 65.8% of pathogenic serotypes were revealed. Moreover, all marked E. coli isolated from the abdominal cavity of children and adults, as well as museum strains related to enteropathogenic E. coli (O127: K63, O33: K-) and 1 – to enteroinvazive Escherichia coli (O144: K-).

Significance and Characteristics ofListeria monocytogenesin Poultry Products

Listeria monocytogenesis one of the most common foodborne pathogens. Poultry meat and products are of the main vehicles of pathogenic strains ofL. monocytogenesfor human. Poultry products are part of the regular diet of people and, due to nutrient content, more content of protein, and less content of fat, gain more attention. In comparison with red meat, poultry meat is more economical. So, it had a greater rate of consumption especially in barbecue form in which the growth of bacterium is favored. Subtyping ofL. monocytogenesisolates is essential for epidemiological investigation and for identification of the source of contamination. In the following review, the main facet of presence ofL. monocytogenesin poultry will be discussed. Most pathogenic serotypes ofL. monocytogeneswere detected in different products of poultry meat. Unfortunately, these isolated pathogens had sometimes resistance to commonly used antibiotics which were used for treatment of human infection.

Serotyping Isolated Strains of Salmonella for Consomption in the Eastern Logone Province in Chad

The present work was carried out in the Doba petroleum basin, Eastern Logone Province, and focused on the serotyping of strains of salmonella isolated in well water, boreholes and rivers for the consumption of the population. The sampling was carried out according to a complete randomized device with 10 samples per source of water, making a total of 30 samples. Salmonellae were detected according to the French standard ISO 6579: 2002, followed by serotyping. The results of the biochemical identification test of the API 20 E gallery led, thanks to the Apiweb Tm-API 20E V4.1 site to Salmonella spp. The serotyping results revealed, according to the White-Kauffmann-Le Minor table, serovars Anatum, Mbandaka and Idikan. S. Anatum was detected in P4 well waters and F6 wells; S. Mbandaka, in F9 and R8 river water; and finally, S. Idikan, in F5 and R4 river water. These results show a homogeneous distribution of these serotypes in the different water sources of the study area. The presence of these pathogenic serotypes in drinking water sources attests that these waters are unhealthy in accordance with WHO's guidelines for drinking quality. Corrective measures are needed to improve the quality of these water rich in germs that may cause food poisoning.

Occurrence of Salmonella on poultry farms, in flocks of pigeons and feed monitored by the Department of Veterinary Hygiene in Olsztyn in the years 2014-2015

The aim of the study was to analyze the frequency of the occurrence of Salmonella and their serotypes on poultry farms, in flocks of pigeons, and feed monitored by the Department of Veterinary Hygiene in Olsztyn in the years 2014-2015. The quantitative and qualitative analysis was conducted according to the requirements of Polish Standards. On the poultry farms 0.9% samples gave positive results and in 2015 the percentage of infected farms was 0.3% lower compared to 2014. S. Enteritidis serotypes were isolated from 0.2% samples from poultry farms and S. Typhimurium from 0.08%. These two most pathogenic serotypes were isolated three times more in 2014 (in 0.41% of cases). S. Enteritidis is the most frequently observed serotype (particularly in broiler chickens) and compared with the results of the previous years (2001-2005) in the same region, the number of cases of this serotype in broiler flocks decreased markedly. Next, there were S. Lexington, S. Kentucky, S. Typhimurium and S. Mbandaka. In 2015 the intensity of the occurrence of S. Enteritidis on farms decreased, and the percentage of positive results S. Enteritidis or S. Typhimurium was the same as in the case of S. Kentucky and S. Mbandaka. In pigeon flocks all isolates belonged to S. Typhimurium, accounting for 2.4%. In the case of feed, 1.34% of positive results were found (0.3% in blends for poultry). The implementation of EU programs to reduce Salmonella contributed to a significant reduction of infected poultry flocks and feed, but at the same time there is a greater variety of serotypes of Salmonella, which on account of their antibiotics resistance may pose a risk.