Virus deals anthrax a killer blow

Bacillus telluris sp. nov. Isolated from Greenhouse Soil in Beijing, China

A novel Gram-stain-positive, rod-shaped, endospore-forming bacterium, which we designated as strain 03113T, was isolated from greenhouse soil in Beijing, China. Phylogenetic analysis based on 16S rRNA gene sequences showed strain 03113T is in the genus Bacillus and had the highest similarity to Bacillus solani CCTCC AB 2014277T (98.14%). The strain grew at 4 °C-50 °C (optimum 37 °C), with 0-10% (w/v) NaCl (optimum 5%), and in the range of pH 3.0-12.0 (optimum pH 8.0). Menaquinone was identified as MK-7, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The main major cellular fatty acids detected were anteiso-C15:0 (51.35%) and iso-C15:0 (11.06%), which are the predominant cellular fatty acids found in all recognized members of the genus Bacillus. The 16S rRNA gene sequence and core-genome analysis, the average nucleotide identity (ANI), and in silico DNA-DNA hybridization (DDH) value between strain 03113T and the most closely related species were 70.5% and 22.6%, respectively, which supported our conclusion that 03113T represented a novel species in the genus Bacillus. We demonstrated that type strain 03113T (=ACCC 03113T=JCM 33017T) was a novel species in the genus Bacillus, and the name Bacillus telluris sp. nov. was proposed. Strain 03113T secreted auxin IAA and carried the nitrogenase iron protein (nifH) gene, which indicated that strain 03113T has the potential to fix nitrogen and promote plant growth. Bacillus telluris sp. nov. 03113T is a potential candidate for the biofertilizers of organic agriculture areas.

Investigations on the interactions of λphage-derived peptides against the SrtA mechanism in Bacillus anthracis

Bacillus anthracis is a well-known bioweapon pathogen, which coordinates the expression of its virulence factors in response to a specific environmental signal by its protein architecture. Absences of sortase signal functioning may fail to assemble the surface linked proteins and so B. anthracis cannot sustain an infection with host cells. Targeting the signaling mechanism of B. anthracis can be achieved by inhibition of SrtA enzyme through λphage-derived plyG. The lysin enzyme plyG is experimentally proven as bacteriolytic agent, specifically kill's B. anthracis by inhibiting the SrtA. Here, we have screened the peptides from λphage lysin, and these peptides are having the ability as LPXTG competitive inhibitors. In comparison to the activator peptide LPXTG binding motif, λphage lysin based inhibitor peptides are having much supremacy towards binding of SrtA. Finally, peptide structures extracted from PlyG are free from toxic, allergic abilities and also have the ability to terminate the signal transduction mechanism in B. anthracis.

Sensitive Detection ofBacillus anthracisUsing a Binding Protein Originating from γ-Phage

Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great concern is the detection of Bacillus anthracis, the causative agent of anthrax. Therefore, there is a pressing need to develop novel methods for rapid, simple, and precise detection of B. anthracis. Here, we report that the C-terminal region of gamma-phage lysin protein (PlyG) binds specifically to the cell wall of B. anthracis and the recombinant protein corresponding to this region (positions, 156-233), PlyGB, is available as a bioprobe for detection of B. anthracis. Our detection method, based on a membrane direct blot assay using recombinant PlyGB, was more rapid and sensitive than the gamma-phage test and was simpler and more inexpensive than genetic methods such as PCR, or immunological methods using specific antibodies. Furthermore, its specificity was comparable to the gamma-phage test. PlyGB is applicable in conventional methods instead of antibodies and could be a potent tool for detection of B. anthracis.

Phage lysin to control the overgrowth of normal flora in processed sputum samples for the rapid and sensitive detection of Mycobacterium tuberculosis by luciferase reporter phage assay

Background

Phage lysin, extracted from three bacteriophages was used in place of antibiotics to control the overgrowth of normal flora in processed sputum samples leading to the sensitive detection of Mycobacterium tuberculosis using diagnostic luciferase reporter phage assay (DLRPA).

Methods

A total of 129 sputum samples were processed by modified Petroff’s method. Two Lowenstein Jensen slopes were inoculated from the processed sputum deposit thus obtained. The remaining deposits were transferred to 7 ml of Middlebrook 7H9 complete medium supplemented with phage lysin and incubated at 37°C. DLRPA was done using phAE129 at days 7, 9, 14 and 21. At the end of day 21, the samples were centrifuged and the pellets were inoculated on to 2 more LJ slopes to validate DLRPA results.

Results

The sensitivity and specificity of DLRPA in detecting M. tuberculosis from sputum specimens was 90% and 81% respectively compared to conventional LJ culture. The agreement between the methods was 87%. The rate of contamination for DLRPA using phage lysin was 9.3%.

Conclusion

Phage lysin can be used to decontaminate sputum samples for the detection of M. tuberculosis by DLRPA directly from processed sputum specimens.

Recombinant bacteriophage lysins as antibacterials

With the increasing worldwide prevalence of antibiotic resistant bacteria, bacteriophage endolysins (lysins) represent a very promising novel alternative class of antibacterial in the fight against infectious disease. Lysins are phage-encoded peptidoglycan hydrolases which, when applied exogenously (as purified recombinant proteins) to Gram-positive bacteria, bring about rapid lysis and death of the bacterial cell. A number of studies have recently demonstrated the strong potential of these enzymes in human and veterinary medicine to control and treat pathogens on mucosal surfaces and in systemic infections. They also have potential in diagnostics and detection, bio-defence, elimination of food pathogens and control of phytopathogens. This review discusses the extensive research on recombinant bacteriophage lysins in the context of antibacterials, and looks forward to future development and potential.

Complete Nucleotide Sequence and Molecular Characterization of Bacillus Phage TP21 and its Relatedness to Other Phages with the Same Name

Three different Bacillus bacteriophages designated TP21 are known from the literature. We have determined the sequence and structure of the TP21-L genome, and compared it to the other phages. The genome is 37.5 kb in size, possesses fixed invariable genome ends and features the typical modular organization of a temperate siphovirus. TP21-L is neither identical to TP21 isolated by Thorne (TP21-T), as shown by a PCR-based approach nor to TP21 isolated by He et al. (TP21-H), as estimated from phage dimensions. For reasons of clarity, we suggest renaming the different TP21 isolates.

Production and validation of the use of gamma phage for identification of Bacillus anthracis

Gamma phage specifically lyses vegetative cells of Bacillus anthracis and serves as part of the basis for identification of isolates from agar cultures. We report our study to standardize gamma phage production and preparation and to validate the assay for routine use. Unstable phage preparations were largely reduced through propagation of phage on blood agar cultures of the avirulent B. anthracis strain CDC684 and were adequately stable for extended storage beyond 1 to 2 years at 4 degrees C, provided that the preparation initially gave rise to clearly discernible plaques (macroplaques, 5 to 10 mm in diameter) on dilution at 1:8 or greater during potency testing with the Sterne strain or its equivalent. The primary intent of the assay was to test nonhemolytic, ground-glass-appearing bacterial B. anthracis-like colonies arising from culture of clinical or nonclinical samples on 5% sheep blood agar. Specifically, the assay was designed to show clear or primarily clear circular zones of lysis on bacterial lawns at the site of gamma phage inoculation after incubation at 35 degrees C +/- 2 degrees C for 20 h. When tested with 51 B. anthracis strains and 49 similar non-B. anthracis Bacillus species, the analytical specificity was >95%, a value that is intentionally low because our study design included two rare nonsusceptible B. anthracis strains as well as a rare susceptible non-B. anthracis strain, B. cereus ATCC 4342. Repeatability, day-to-day precision, and analyst-to-analyst precision were superior. The assay was rugged to variations among phage lots, phage concentration, amounts of bacterial inoculum, and incubation times as short as 6 to 8 h. System suitability evaluation showed improved robustness when bacterial lawns were tested with high- and low-density inoculum using the first and second quadrants of a serial four-quadrant streak on 5% sheep blood agar plates.