Vasco Azevedo

Molecular characterization of Corynebacterium pseudotuberculosis isolates using ERIC-PCR

Caseous lymphadenitis is an infectious sheep and goats disease caused by Corynebacterium pseudotuberculosis and characterized by abscesses in superficial and visceral lymph nodes. C. pseudotuberculosis strains isolated from these hosts have been shown to be very difficult to type by the existing methods. The aim of this study is evaluating the potential of the Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) as a tool for molecular typing of C. pseudotuberculosis strains isolated in sheep. One hundred and twenty seven isolates of C. pseudotuberculosis were isolated from lesions suspected to have had caseous lymphadenitis collected from sheep at the slaughterhouse. Animals were from 24 flocks in 13 municipalities of the Minas Gerais State, Brazil. Species identification of the isolates was performed by routine biochemical tests and mPCR. Fingerprint was performed by RAPD using ERIC-1R, ERIC-2 and ERIC-1R+ERIC-2 primers. Seventeen different genotypes were generated by ERIC 1-PCR, 21 genotypes by ERIC 2-PCR and 21 genotypes by ERIC 1+2-PCR. Hunter-Gaston Discrimination Index (HGDI) found for ERIC 1, ERIC 2, ERIC 1+2 PCR were 0.69, 0.87, and 0.84, respectively. For most herds evaluated observed at most three different genotypes among isolates from animals of these property, in all ERIC-PCR assays. However a few flocks observed between four and nine genotypes per flock. The W Kendall value found for correlation among the three techniques of ERIC-PCR was 0.91 (P<5.0 x 10(-6)). The results show that ERIC-PCR has good discriminatory power and advantages over other DNA-based typing methods, making it a useful tool to discriminate C. pseudotuberculosis isolates.

High sero-prevalence of caseous lymphadenitis identified in slaughterhouse samples as a consequence of deficiencies in sheep farm management in the state of Minas Gerais, Brazil

BackgroundCaseous lymphadenitis (CLA), caused by Corynebacterium pseudotuberculosis, is one of the most important diseases of sheep and goats, causing considerable economic losses for herd owners.ResultsWe assessed the seroprevalence of infection with C. pseudotuberculosis in 805 sheep from 23 sheep farms that supply slaughterhouses in the state of Minas Gerais; we also analyzed management practices that could be associated with CLA occurrence, used on these and nearby farms that also supplied animals to the slaughterhouse (n = 60). The serum samples for assaying CLA infection were taken at the slaughterhouse. Frequency of infection with C. pseudotuberculosis was estimated at 43.7%, and farm frequency was estimated at 100%. Management practices were analyzed through a questionnaire. All farmers (60/60) had extensive/semi-extensive rearing system; 70.0% (42/60) identified sheep individually; 11.7% (7/60) had periodical technical assistance; 41.7% (25/60) disinfected the facilities; 86.7% (52/60) used barbed wire fences and did not implement adequate CLA control measures; only 11.7% (7/60) of breeders reported vaccination against C. pseudotuberculosis; 13.3% (8/60) took note of animals with clinical signs of CLA; 1.7% (1/60) opened and sanitized abscesses, and isolated the infected animals; 10.0% (6/60) knew the zoonotic potential of this disease and 1.7% (1/60) of the farmers culled animals in case of recurrence of abscesses.ConclusionsIt can be concluded that C. pseudotuberculosis infection is widely spread in sheep flocks in Minas Gerais state in Brazil and that there is a lack of good management measures and vaccination, allowing transmission of this infectious agent throughout the production network.

Mechanisms Involved in the Anti-Inflammatory Properties of Native and Genetically Engineered Lactic Acid Bacteria

Fil: Leblanc, Jean Guy Joseph. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Tucuman. Centro de Referencia para Lactobacilos (i); Argentina;

Draft Genome Sequences of Two Species of "Difficult-to-Identify" Human-Pathogenic Corynebacteria: Implications for Better Identification Tests.

Non-diphtheriae Corynebacterium species have been increasingly recognized as the causative agents of infections in humans. Differential identification of these bacteria in the clinical microbiology laboratory by the most commonly used biochemical tests is challenging, and normally requires additional molecular methods. Herein, we present the annotated draft genome sequences of two isolates of “difficult-to-identify” human-pathogenic corynebacterial species: C. xerosis and C. minutissimum. The genome sequences of ca. 2.7 Mbp, with a mean number of 2,580 protein encoding genes, were also compared with the publicly available genome sequences of strains of C. amycolatum and C. striatum. These results will aid the exploration of novel biochemical reactions to improve existing identification tests as well as the development of more accurate molecular identification methods through detection of species-specific target genes for isolates identification or drug susceptibility profiling.

Prospective Uses of Genetically Engineered Lactic Acid Bacteria for the Prevention of Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a term used to describe a group of intestinal disorders in which inflammation is a major feature. Although rare forms of IBD exist, these diseases normally pertain to ulcerative colitis (UC) (Head & Jurenka, 2003) and Crohn’s disease (CD) (Baumgart & Sandborn, 2007). There is evidence that these do not represent distinct conditions but rather are the same disease with shared etiological factors (Price, 1992); however, clinical manifestations (such as the exact location of the pathology or the affected individual’s immunological and constitutional endowment) are distinctive between both. Despite many years of study, the exact etiology and pathogenesis of these disorders remain unclear but great advances have been made using experimental animal models and have provided insights into the complex, multi-factorial processes and mechanisms that can result in chronic intestinal inflammation (Elson & Weaver, 2003). The aim of this chapter is to present an overview of the current expanding knowledge of the mechanisms by which lactic acid bacteria and other probiotic microorganisms participate in the prevention and treatment of IBD and how genetic engineering techniques can be used to improve their effectiveness or create novel therapeutic strains. In the following sections, the mechanisms by which these beneficial microorganisms exert their therapeutic effects, which include changes in the gut microbiota, stimulation of the host immune responses, enhancement of intestinal barrier function and reduction of the oxidative stress due to their antioxidant properties will be discussed.

Microbial Omics: Applications in Biotechnology

Abstract Omics studies are the global analysis of biologic systems that are explored intensively due to the large number of known genomes that involve the knowledge of structural and functional genomics. In this chapter, the subject of omics approaches related to microbial biotechnology, which encompasses various sciences, will be addressed along with their applications in a variety of fields: medical, agricultural, industrial, and environmental applications. This chapter starts with a brief introduction concerning the theme. Section 1.2 covers genome sequencing, comparative genomics, pan-genomics, and immunogenomics. Section 1.3 deals with transcriptomics, proteomics, metabolomics, and interactomics, to understand the organism better. This also comprises isolating and characterizing the genes, proteins, and metabolites and analyzing the interaction between them. Finally, this chapter focuses on the conclusions and the perspectives about this subject.

Exfoliative Toxins of Staphylococcus aureus

Virulent strains of Staphylococcus aureus secrete exfoliative toxins (ETs) that cause the loss of cell‐cell adhesion in the superficial epidermis. S. aureus ETs are serine proteases, which exhibit exquisite substrate specificity, and their mechanisms of action are extremely complex. To date, four different serotypes of ETs have been identified and three of them (ETA,ETB and ETD) are associated with toxin‐mediated staphylococcal syndromes related tonhuman infections leading to diseases of medical and veterinary importance.

Pathogenesis of Corynebacterium diphtheriae and available vaccines: An Overview

Corynebacterium diphtheriae is Gram-positive bacteria responsible for causing diphtheria in human nand once regarded for high mortalities worldwide.

Protein-Protein Interactions: An Overview

The proteins perform their activities in a cell through their interactions, forming a complex protein-protein interaction network (PIN) that can contain tens of thousands of interactions. Knowing the interactions enables know how the organism performs its functions internally and how it interacts with the host. In Bioinformatics, by using graph theory from the computer science area, we can calculate measurements on PINs revealing relevant biological information. Knowing these measures as they are calculated, and their biological relevance is key to validating and interpreting PINs, since it is humanly impossible to analyze and extract information in complex PINs. PINs from various organisms, generated by experimental or computational methods, can be found and downloaded from the public databases for further analysis. PINs for an organism of interest can be generated by experimental methods or predicted by computational methods in both low or large scale. Knowing the biological assumptions underlying each method, whether the method is able to predict new interactions or identify previously characterized interactions, as well as advantages and disadvantages, is essential to select the method appropriate to our purpose. Regardless of the method used, biological PINs can be applied in various contexts such as hypothetical protein annotation, understanding the organism at systems biology level, identifying essential or important proteins in a biological context to be used as a target for drugs, identifying host-pathogen interactions to suggest vaccine targets, in addition to enabling research to identify a new drug class inhibiting or stabilizing interaction. PINs are generated not as the ultimate goal of a research but rather as a tool to better understand the mechanisms of action of an organism and to direct future experiments in the laboratory. In this article, we have discussed various aspects of PINs including their applications.

Draft Genome Sequences of Two Pathogenic Corynebacterial Species Isolated from Cows.

The species Corynebacterium renale, Corynebacterium pilosum, and Corynebacterium cystitidis were initially thought to be the same species C. renale, but with different immunological types. These bacteria are the causative agent of cystitis, urethritis and pyelonephritis and are found usually as constituents of the normal flora in the lower urogenital tract of cattle. Therefore, we present the draft genome sequences of two pathogenic Corynebacterium species: C. renale CIP 52.96 and C. pilosum CIP 103422. The genome sequences of these species have 2,322,762 bp with 2,218 protein encoding genes and 2,548,014 bp with 2,428 protein encoding genes, respectively. These genomes can help clarify the virulence mechanisms of these unknown bacteria and enable the development of more effective methods for control.