Eliane Pereira Mendonça

Transfer, viability and colonisation of Campylobacter jejuni in the chicken vitellus and in embryos

1. The objective of this study was to evaluate the ability of Campylobacter jejuni to penetrate and colonise eggs from specific-pathogen-free (SPF) and heavy breeder hens, and to determine its effects on the viability of SPF embryos. 2. We detected C. jejuni in 10% of breeder hens and 20% of SPF eggs, which demonstrates the ability of the bacteria to go through the pores of eggs and contaminate the vitellus after 3 h of contact. These results indicate that there is a risk of contamination under commercial production conditions, where, after oviposition, there is contact between the egg and organic material such as faeces and blood. 3. We observed that in 80% of SPF eggs analysed, C. jejuni survived the 21-d incubation period. This positive result suggests that this microorganism was also responsible for early embryonic mortality. 4. The ability of C. jejuni to penetrate the eggs in this study suggests that serious problems may occur under natural field conditions, which may cause significant problems for producers.

Identificação sorológica e relação filogenética de Salmonella spp. de origem suína

Salmonella spp. is an important zoonotic pathogen that can spread along the production chain of swines. The objective was to evaluate the incidence of Salmonella spp. in feces of swines in termination phase in the farm, in the pre-slaughter and environmental samples, identify the serotypes and establish a phylogenetic relationship among the isolates. Three collections were done in different batches of pigs housed in the termination pen and in the same animals after transport to the slaughterhouse totaling 90 plots and 9 environmental samples. The transport does not influenced the percentage of isolation of the microorganism (p>0.05). Of the total of 99 samples, 50 (50.5%) were identified as Salmonella spp., and was identified a variety of serovars: Agona (30%), Typhimurium (26%), Minnesota (24%), Infantis (18%) and Panama (2%). Dendrograms showed homology among isolates of different serovars grouped into clusters. The similarity was independent of the local of isolation, indicating the presence of several clones. The main sources of infection were cross-contamination between animals and environment and the consumption of contaminated feed. The diversity of strains and homology among the isolates indicates a common origin, demonstrating a need for monitoring of zoonotic bacterias and the deployment of more effective control measures for Salmonella spp. in swines.

Campylobacter jejuni in commercial eggs

This study evaluated the ability of Campylobacter jejuni to penetrate through the pores of the shells of commercial eggs and colonize the interior of these eggs, which may become a risk factor for human infection. Furthermore, this study assessed the survival and viability of the bacteria in commercial eggs. The eggs were placed in contact with wood shavings infected with C. jejuni to check the passage of the bacteria. In parallel, the bacteria were inoculated directly into the air chamber to assess the viability in the egg yolk. To determine whether the albumen and egg fertility interferes with the entry and survival of bacteria, we used varying concentrations of albumen and SPF and commercial eggs. C. jejuni was recovered in SPF eggs (fertile) after three hours in contact with contaminated wood shavings but not in infertile commercial eggs. The colonies isolated in the SPF eggs were identified by multiplex PCR and the similarity between strains verified by RAPD-PCR. The bacteria grew in different concentrations of albumen in commercial and SPF eggs. We did not find C. jejuni in commercial eggs inoculated directly into the air chamber, but the bacteria were viable during all periods tested in the wood shavings. This study shows that consumption of commercial eggs infected with C. jejuni does not represent a potential risk to human health.

Biofilms of Salmonella and Campylobacter in the Poultry Industry

Biofilm is characterized by a bacterial population firmly adhered to a surface involved by a self-produced matrix of extracellular polymeric substance. These communities provide longer survival and resistance to adverse conditions such as presence of antibiotics and disinfectants. Various foodborne microorganisms are capable of forming such structures, including Salmonella and Campylobacter, which are the major contaminants at the poultry industry. This biomass can affect the water transport system and pipes, and once the agent is established at the industry, it can form biofilms in any processing area. There are intrinsic and extrinsic mechanisms, and also molecular aspects involved in the biofilm formation. The adoption of several strategies may exhibit effectiveness to prevent the cell adhesion, such as the use of surfaces resistant to biofilm formation. In case of preexisting biofilms, there are physical, chemical, and biological methods used to control and eliminate them. Nanotechnology has emerged as another effective measure as nanometals affect the essential activities of microorganisms. These findings highlight the difficulty in controlling biofilms, due to the strategies used by these agents to adapt and survive in sessile form, causing recurring contamination throughout the poultry chain production, deterioration in the final product and infections in the human host.

Intrinsic and Extrinsic Aspects on Campylobacter jejuni Biofilms

Biofilm represents a way of life that allows greater survival of microorganisms in hostile habitats. Campylobacter jejuni is able to form biofilms in vitro and on surfaces at several points in the poultry production chain. Genetic determinants related to their formation are expressed differently between strains and external conditions are decisive in this respect. Our approach combines phylogenetic analysis and the presence of seven specific genes linked to biofilm formation in association with traditional microbiology techniques, using Mueller Hinton and chicken juice as substrates in order to quantify, classify, determine the composition and morphology of the biomass of simple and mixed biofilms of 30 C. jejuni strains. It also evaluates the inhibition of its formation by biocides commonly used in industry and also by zinc oxide nanoparticles. Genetic analysis showed high heterogeneity with the identification of 23 pulsotypes. Despite the diversity, the presence of flaA, cadF, luxS, dnaJ, htrA, cbrA, and sodB genes in all strains shows the high potential for biofilm formation. This ability was only expressed in chicken juice, where they presented phenotype of a strong biofilm producer, with a mean count of 7.37 log CFU/mL and an ultrastructure characteristic of mature biofilm. The composition of simple and mixed biofilms was predominantly composed by proteins. The exceptions were found in mixed biofilms with Pseudomonas aeruginosa, which includes a carbohydrate-rich matrix, lower ability to sessile form in chicken juice and compact architecture of the biofilm, this aspects are intrinsic to this species. Hypochlorite, chlorhexidine, and peracetic acid were more effective in controlling viable cells of C. jejuni in biofilm, but the existence of tolerant strains indicates exposure to sublethal concentrations and development of adaptation mechanisms. This study shows that in chicken juice C. jejuni presents greater potential in producing mature biofilms.

Transmission of Campylobacter coli in chicken embryos

Campylobacter coli is an important species involved in human cases of enteritis, and chickens are carriers of the pathogen mainly in developing country. The current study aimed to evaluate the transmission of C. coli and its pathogenic effects in chicken embryos. Breeder hens were inoculated intra-esophageally with C. coli isolated from chickens, and their eggs and embryos were analyzed for the presence of bacteria using real-time PCR and plate culture. The viability of embryos was verified. In parallel, SPF eggs were inoculated with C. coli in the air sac; after incubation, the embryos were submitted to the same analysis as the embryos from breeder hens. In embryos and fertile eggs from breeder hens, the bacterium was only identified by molecular methods; in the SPF eggs, however, the bacterium was detected by both techniques. The results showed no relationship between embryo mortality and positivity for C. coli in the embryos from breeder hens. However, the presence of bacteria is a cause of precocious mortality for SPF embryos. This study revealed that although the vertical transmission is a possible event, the bacteria can not grow in embryonic field samples.

Feed can be a source of Campylobacter jejuni infection in broilers

ABSTRACT 1. The aim was to determine the importance of a contaminated diet as a possible cause of Campylobacter jejuni infection in broilers. 2. This study evaluated the viability of C. jejuni in both starter and finisher diets and the interference from other mesophilic bacteria in this viability. 3. Starter and finisher samples of broiler diet were deliberately contaminated with 3 or 5 log CFU·g−1 of C. jejuni (NCTC 11351) and then maintained at two different storage temperatures (25°C or 37°C) for 3 or 5 d. 4. C. jejuni survived during this period and, when inoculated at 103 CFU·g−1, multiplied with greater proliferation at a storage temperature of 37°C. There was no relationship between the amount of mesophilic bacteria and C. jejuni viability. 5. This study highlights the importance of the diet in the epidemiology of C. jejuni in broilers.

Apostila ilustrada de cirurgia veterinária

This material is an illustrated textbook of surgery that has the function to offer consultation support to the learner of Veterinary Surgery, addressing the topics: Instrumentalization Surgical, Suture Materials, Surgical General Principles, Surgical Incisions of the Abdominal Wall and Sutures Used in Veterinary Medicine.

Epidemiology of Campylobacter in Farms

Chickens are recognized as natural hosts of Campylobacter and infected poultry carry a high pathogen load in their gastrointestinal tract. There are large gaps in our understanding about factors leading to colonization of Campylobacter and subsequent transmission among birds, given that the source of Campylobacter in chickens and specific mechanisms entering the flock are not fully clear yet. This chapter summarizes the epidemiology of Campylobacter in poultry flocks and considers current issues on the subject.

Campylobacter spp.: Capacity of Biofilm Formation and Other Strategies of Survival and Adaption to Remain in the Poultry Industry

By presenting the epidemiology of Campylobacter and the main challenges in its control, this chapter reviews the mechanisms used by these microorganisms to adapt and survive in the poultry industry. Despite Campylobacter’s apparent fragility to environmental conditions, this agent is flexible and can adapt its metabolism and growth levels to an industrial environment. This chapter addresses mechanisms such as genome modulation, tolerance to high and low temperatures, tolerance to oxidative and nutrition stress, quorum-sensing systems, and the capacity of biofilm formation. These abilities are discussed, with consideration of the potential of different behaviors that can explain the organism’s ability to survive and multiply in poultry, thus affecting the prevalence of Campylobacter in the final product.