Methicillin-resistant strains of Staphylococcus aureus (MRSA) are now the most commonly reported antibiotic-resistant bacterium in clinical settings. Therefore, there is an urgent need to develop novel antibacterial agents to control this pathogen. Bacteriophage therapy is a potential alternative treatment for MRSA infections. The objective of this study was characterization of a novel virulent bacteriophage (MSA6) isolated from a cow with mastitis. Electron microscopy showed its resemblance to members of the family Myoviridae, with an isometric head (66 nm) and a long contractile tail (173 nm). The genome of phage MSA6 was tested by pulsed-field gel electrophoresis and estimated to be about 143 kb. It exhibited rapid adsorption (>82% in 5 min), a short latent period (15 min) and a relatively small burst size (23 PFU/cell). Isolated phage was capable of infecting a wide spectrum of staphylococcal strains of both human and bovine origin. The results of this investigation indicate that MSA6 is similar to other bacteriophages belonging to the family Myoviridae (Twort, K, G1, 812) that have been successfully used in bacteriophage therapy.

The emergence of resistance in microorganisms on a global scale has made it necessary to search for new antimicrobial factors. Antimicrobial peptides (AMPs) seem to meet these expectations. AMPs are produced by bacteria, viruses, plants, and animals, and may be considered as a new class of drugs intended for the prophylaxis and treatment of both systemic and topical infections. The aim of this study is to review the results of studies on the use of peptides to combat infections in vivo. Antimicrobial peptides may be applied topically and systemically. Among the peptides used topically, a very important area for their application is ophthalmology. AMPs in ophthalmology may be used mainly for the protection of contact lenses from ocular pathogens. Many AMPs are in clinical trials for application in the therapy of local infections. There may be mentioned such preparations as: pexiganan (magainin analogue), MX-226 (based on indolicidin), NEUPREX (isolated from human BPI (bactericidal/permeability-increasing) protein), IB-367 (variant of porcine protegrin), P113 (based on histatin), daptomycin, polymyxins, as well as peptidomimetics. In the combat against systemic infections are used such peptides as: P113D (modified P113 peptide containing D-amino acids), colistin, peptoids, and peptides containing non-typical amino acids or non-peptide elements. AMPs are also used as antiprotozoal, antifungal, antitoxic and immunostimulatory agents. The limitations in the use of peptides in the treatment of infections, such as susceptibility to proteolysis, and resistance of microorganisms to the peptides, are also discussed. AMPs are a promising strategy in the fight against microbial infections.

Aims:  A PCR technique was developed as a reliable and rapid identification method for the Bacillus cereus group species, based on a unique conserved sequence of the motB gene (encoding flagellar motor protein) from B. cereus, Bacillus thuringiensis and Bacillus anthracis. Methods and Results:  Primer locations were identified against eight strains of the B. cereus group spp. from nucleotide sequences available in the National Centre for Biotechnology Information database. The PCR assay was applied for the identification of 117 strains of the B. cereus group spp. and 19 strains from other microbial species, with special emphasis on foodborne pathogens. Conclusion:  The designed cross‐species primers are group specific and did not react with DNA from other Bacillus and non‐Bacillus species either motile or not. The primers system enabled us to detect 103 CFU of B. cereus cells per millilitre of sample. Significance and Impact of the Study:  Bacillus cereus group spp. belongs to one of the most prevalent foodborne pathogens. Bacterial growth results in production of different toxins; therefore, consumption of food containing >106 bacteria per gram may result in emetic and diarrhoeal syndromes. A rapid and sensitive bacterial detection method is significant for food safety.

Modern threats of bioterrorism force the need to develop methods for rapid and accurate identification of dangerous biological agents. Currently, there are many types of methods used in this field of studies that are based on immunological or genetic techniques, or constitute a combination of both methods (immuno-genetic). There are also methods that have been developed on the basis of physical and chemical properties of the analytes. Each group of these analytical assays can be further divided into conventional methods (e.g. simple antigen-antibody reactions, classical PCR, real-time PCR), and modern technologies (e.g. microarray technology, aptamers, phosphors, etc.). Nanodiagnostics constitute another group of methods that utilize the objects at a nanoscale (below 100 nm). There are also integrated and automated diagnostic systems, which combine different methods and allow simultaneous sampling, extraction of genetic material and detection and identification of the analyte using genetic, as well as immunological techniques.

Coxiella burnetii is the etiologic agent of Q fever. It may occur as two different morphological forms, a large cell variant (LCV) and a small cell variant (SCV). The SCV is characterized by unique resistance to physical and chemical factors and may survive in the environment for many months. The objective of this study was to examine environmental samples for the presence of C. burnetii using real-time PCR in areas where Q fever was previously reported and in randomly selected animal farms where Q fever was not reported. The samples were collected in the following provinces in Poland: Lublin, Subcarpathian and Masovian. Monitoring was performed with real-time PCR and serological methods. Of the 727 environmental samples, 33 (4.54%) contained the multi-copy insertion sequence IS1111, which is specific for C. burnetii. Subsequently, the presence of C. burnetii antibodies was determined using serological tests in selected herds in which positive genetic results were obtained. Serological analyses of 169 serum samples using CFT and ELISA were performed on Polish black-and-white Holstein-Friesian cows and one cow imported from Denmark. Using the CFT method, 11 samples were positive for phase I antibodies and six were positive for phase II antibodies. Moreover, in two cases, the presence of antibodies specific for both phase I and phase II antigens of C. burnetii was detected. However, of the 169 examined serum samples, 20 were positive by ELISA test, of which six were also positive by CFT. Additionally, multi spacer typing (MST) of isolated C. burnetii strains was performed. The MST results identified two new genotypes in Poland, ST3 and ST6. The results indicate that continued research regarding spread of this pathogen within a country is necessary.