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Bacillus anthracis is a potent biowarfare agent, able to be highly lethal. The bacteria dwell in the soil of certain regions, as natural flora. Bacteriophages or their lytic enzymes, endolysins, may be an alternative for antibiotics and other antibacterials to fight this pathogen in infections and to minimize environmental contamination with anthrax endospores. Upon screening environmental samples from various regions in Poland, we isolated three new siphophages, J5a, F16Ba, and z1a, specific for B. anthracis. They represent new species related to historical anthrax phages Gamma, Cherry, and Fah, and to phage Wbeta of Wbetavirus genus. We show that the new phages and their closest relatives, phages Tavor_SA, Negev_SA, and Carmel_SA, form a separate clade of the Wbetavirus genus, designated as J5a clade. The most distinctive feature of J5a clade phages is their cell lysis module. While in the historical phages it encodes a canonical endolysin and a class III holin, in J5a clade phages it encodes an endolysin with a signal peptide and two putative holins. We present the basic characteristic of the isolated phages. Their comparative genomic analysis indicates that they encode two receptor-binding proteins, of which one may bind a sugar moiety of B. anthracis cell surface.

Protective antigen domain 4 of Bacillus anthracis as a candidate for use as vaccine for anthrax.

Despite its low virulence potential and a commensal lifestyle as a member of the human skin microbiota, Brevibacterium casei has been increasingly reported as an opportunistic pathogen, especially in immunocompromised patients. Here, we present the draft genome sequence of the S51 strain isolated from a bloodstream infection. To the best of the authors' knowledge, this is the first report of the draft genome sequence of the B. casei strain isolated from the clinical infection. The strain was identified using phenotypic and molecular methods and subsequently sequenced using the next-generation sequencing. The draft whole genome was assembled de novo, automatically annotated by Rapid Annotations using Subsystems Technology (RAST) server and scrutinized to predict the presence of virulence, resistance, and stress response proteins. The genome size of the S51 strain was 3,743,532 bp and an average G+C content was 68.3%. The predicted genes included 48 genes involved in resistance to antibiotics (including vancomycin, fluoroquinolones, and beta-lactams) and toxic compounds (heavy metals), 16 genes involved in invasion and intracellular resistance (Mycobacterium virulence operons), and 94 genes involved in stress response (osmotic, oxidative stress, cold and heat shock). ResFinder has indicated the presence of a beta-lactamase, and a phenotypic analysis showed resistance to penicillin. This whole-genome NGS project for the S51strain has been deposited at EMBL/GenBank under the accession no. QNGF00000000.

In this work, ticks were collected from the military area of the West Pomeranian Voivodeship in Poland, and the most important pathogens were detected using the real-time PCR method. The ticks were collected in mid-spring (April and May) using the flagging technique. They were collected in five places: on the shoreline of Drawa River and Konotop Lake, as well as in forest and meadow areas near Karwice, Konotop and Oleszno Villages. During the work, only one species of ticks was caught – Ixodes ricinus. All the collected specimens were assessed in terms of their species, sex and developmental stage by zoological specialists. The largest number of specimens was caught in Karwice (35%, n = 666). The highest number of ticks in each test site were nymphs (57%, n = 1106), except at Konotop. The reaction of RT-PCR was tested in 111 pools of ticks. As a result of the PCR reactions (VIASURE Tick-Borne Diseases Real-Time PCR Detection Kit), Rickettsia spp. (n = 70) and Borrelia burgdorferi s. l. (n = 35) were determined to be the most frequently identified pathogens in the tick samples. Other pathogens such as Anaplasma phagocytophilum and Ehrlichia chaffeensis were detected in a smaller number of samples. The results in this paper confirm the epidemiological data collected and analysed prior to now.

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Introduction and objectiveRecombinant vectors derived from adeno-associated viruses (rAAVs) are the leading platform in human gene therapy applications, with high-profile examples targeting diseases of the central nervous system, eye and liver. The liver, quite likely a natural host organ for wild type AAV2, is a particularly attractive target for the development of AAV-mediated gene therapies. Despite large number of AAV variants current at various stages of development as carriers of liver therapeutics, thus far no liver-directed AAV-based therapy has obtained market authorization. Strong preclinical data is the cornerstone of any translational program, and while AAV bioengineering is commonly applied to try to develop novel human-tropic vectors for clinical applications, due to species-to-species differences, dedicated vectors to support preclinical work may need to be developed. Here we applied AAV directed evolution and <i>in vitro</i> selection to identify AAV capsids that target human liver cells <i>in vitro</i>.Material and methodsUsing DNA shuffling technology, we have generated a capsid gene library based on natural parental serotypes (AAV1 through AAV12). Shuffled capsid library was selected in a preclinical model of human liver.ResultsThe AAV variants enriched based on their improved efficiency of transduction of a human hepatocyte cell line were vectorized and subsequently functionally characterized on human cell lines. This directed evolution method enabled us to select novel AAV variant, AAV-CH4.2. While the selected variant did not exceed the parental serotype in terms of transduction efficiency, it was substantially more efficient at packaging than its closest homolog, serotypes AAV6.ConclusionsBased on its strong transduction profile and manufacturability, we believe that AAV-CH4.2 is a strong candidate for further evaluation and as a potential novel gene therapy vector for preclinical studies in human liver applications.