Tertiary amides of Salinomycin: A new group of antibacterial agents against Bacillus anthracis and methicillin-resistant Staphylococcus epidermidis.

For the first time, a series of tertiary amides of polyether antibiotic-Salinomycin have been obtained and screened for their antibacterial activity against different strains of bacteria, including Bacillus anthracis and clinical methicillin-resistant Staphylococcus epidermidis (MRSE). Moreover, biofilm inhibition of MRSE and genotoxicity tests against Bacillus subtilis have been performed. Our studies show that Salinomycin and its some derivatives are active against tested bacteria and exhibited definitely bacteriostatic, not bactericidal activity.

Retrospective review of the case of cutaneous anthrax-malignant pustule from 1995 in 15-year old girl.

A 15-year-old girl was admitted to our Department with cutaneous lesion resembling black eschar. Anamnesis revealed that before getting ill she was wearing pullover made of rough sheep's wool and ornaments made of leather like straps. Cutaneous anthrax was confirmed by identification of B. anthracis in specimens from weeping ulceration, culture from black eschar, thermoprecipitation test, and bioassay on guinea pig. The girl was treated with crystalline Penicillin. She responded well to the therapy and recovered after 28 days. What attracts attention in presented case is the fact that the girl didn't belong to high risk group of human anthrax, which might lead to misdiagnosis. In 1990-1999, Poland there were reported 22 cases of anthrax - it was almost exclusively cutaneous form. In the years following 1999 antrax was reported even less often - in the period 1991-2013 it was recorded a total of 26 cutaneous anthrax cases.

Characterization of a bacteriophage, isolated from a cow with mastitis, that is lytic against Staphylococcus aureus strains.

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.

Isolation and characterization of a novel bacteriophage φ4D lytic against Enterococcus faecalis strains.

In recent years, Enterococcus faecalis has emerged as an important opportunistic nosocomial pathogen capable of causing dangerous infections. Therefore, there is an urgent need to develop novel antibacterial agents to control this pathogen. Bacteriophages have very effective bactericidal activity and several advantages over other antimicrobial agents and so far, no serious or irreversible side effects of phage therapy have been described. The objective of this study was to characterize a novel virulent bacteriophage φ4D isolated from sewage. Electron microscopy revealed its resemblance to Myoviridae, with an isometric head (74 ± 4 nm) and a long contractile tail (164 ± 4 nm). The φ4D phage genome was tested using pulsed-field gel electrophoresis and estimated to be 145 ± 2 kb. It exhibited short latent period (25 min) and a relatively small burst size (36 PFU/cell). Tests were conducted on the host range, multiplicities of infection (MOI), thermal stability, digestion of DNA by restriction enzymes, and proteomic analyses of this phage. The isolated phage was capable of infecting a wide spectrum of enterococcal strains. The results of these investigations indicate that φ4D is similar to other Myoviridae bacteriophages (for example φEF24C), which have been successfully used in phagotherapy.

Lessons learned from 2001-2021 - from the bioterrorism to the pandemic era.

INTRODUCTION AND OBJECTIVE: The aim of the study was to analyze available literature on the development of biological warfare and combating the SARS CoV-2 pandemic. Against the background of contemporary threats from biological factors, the strengths and weaknesses of response in the event of a bioterrorist attack during the ongoing COVID-19 pandemic have been identified. The scope and importance of international cooperation in the fight against the pandemic is assessed. REVIEW METHODS: The more important literature on bioterrorism, biological weapons and the COVID-19 pandemic, both from earlier work and recent publications, was analyzed, emphasizing new threats and adequate defence against them. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: The bio-warfare threat and the current COVID 19 pandemic that has hit mankind on a global scale has clearly shown how dangerous biological agents are and what effects they can cause, negatively affecting every sphere of human activity with catastrophic consequences. Data on examples of bioterrorist attacks carried out and research on the development of biological weapons and methods of combating pandemic COVID-19, were reviewed. New threats related to technological development,including those resulting from genetic manipulation, biosynthesis, and modern means of delivery, are pointed out. Attention has been paid to the implications of controlling the proliferation of biological weapons and the issues of international cooperation in the fight against bioterrorism and the COVD-19 pandemic. SUMMARY: The lesson learned clearly demonstrates the weakness of states in responding to such threats. The risks of uncontrolled scientific advances are still underestimated. Appropriate international control measures must be taken urgently to prepare for new pandemics, bioterrorist attacks, and the possibility of using modern biological weapons.

[Globalization and infectious diseases]. / Globalizacja a choroby zakazne.

Globalization is a phenomenon characteristic of present times. It can be considered in various aspects: economic, environmental changes, demographic changes, as well as the development of new technologies. All these aspects of globalization have a definite influence on the emergence and spread of infectious diseases. Economic aspects ofglobalization are mainly the trade development, including food trade, which has an impact on the spread of food-borne diseases. The environmental changes caused by intensive development of industry, as a result of globalization, which in turn affects human health. The demographic changes are mainly people migration between countries and rural and urban areas, which essentially favors the global spread of many infectious diseases. While technological advances prevents the spread of infections, for example through better access to information, it may also increase the risk, for example through to create opportunities to travel into more world regions, including the endemic regions for various diseases. The phenomenon ofglobalization is also closely associated with the threat of terrorism, including bioterrorism. It forces the governments of many countries to develop effective programs to protect and fight against this threat.

[Peptides--a new strategy for combating viral infections]. / Peptydy--nowe mozliwosci zwalczania zakazen wirusowych.

The efficiency of peptides against many species of bacteria, fungi and parasites has been widely described. Recent studies on peptides have also demonstrated their antiviral activity. Some peptides exhibit direct virucidal activity, others disturb attachment of virus particles to the cell membrane surface or interfere with intracellular replication of virus. Due to limited effectiveness of commonly used drugs and emerging resistance of viruses, antiviral peptides may have the potential to be developed as putative therapeutic agents.

Review of studies on SARS-CoV-2 infection inhibitors.

INTRODUCTION AND OBJECTIVE: COVID-19 is a human infectious disease manifested by acute respiratory syndrome. On 30 January, 2020, the Word Heath Organization (WHO) declared a COVID-19 pandemic. The purpose of this article is to review publications on the search for substances that show inhibitory activity against SARS-CoV-2 infectivity, paying particular attention to the effect on different stages of the life cycle of the virus. REVIEW METHODS: The review was based on an analysis of the latest available scientific literature and international databases. The data collected relate to the years 2020-2021. BRIEF DESCRIPTION OF THE STATE OF KNOWLEDGE: Extremely intensive research is underway to find compounds that inhibit infection with the SARS-CoV-2 virus. Promising areas of research among the many current endeavours are antiviral compounds that stimulate the immune system, counter proliferation or affect individual viral replication cycles. These include, among others, interferons, monoclonal antibodies, natural compounds, peptides, aptamers, metal salts, and anti-inflammatory agents, inhibitors of viral enzymem, such as the RNA-dependent RNA polymerase. Preparations that help the body to combat the effects of infection have also assumed much importance. CONCLUSIONS: The ongoing research is focused on the development of new antiviral agents, as well as the use of the existing drugs on the market. The results of clinical trials are promising and give hope for the development of effective therapies against SARS-CoV-2 and emerging variants of this virus.

[Real time PCR hybridization for the rapid and specific identification of Francisella tularensis]. / Identyfikacja Francisella tularensis technika real-time PCR z wykorzystaniem sond hybrydyzujacych zaprojektowanych dla fragmentów sekwencji genów fopA i tul4.

Tularemia is highly infectious and fatal zoonotic disease caused by Gram negative bacteria Francisella tularensis. The necessity to undergo medical treatment in early phase of illness in humans and possibility of making use of bacterial aerosol by terrorists in an attack create an urgent need to implement a rapid and effective method which enables to identify the agent. In our study two primers FopA F/R and hybridization probes FopA S1/S2 designed from fopA gene sequence, were tested for their potential applicability to identify F. tularensis. In this research 50 strains of F. tularensis were used and the test gave positive results. Reaction specificity was confirmed by using of non-Francisella tularensis bacterial species. The results obtained in the real-time PCR reaction with primers Tul4 F/R and hybridization probes Tul4 S1/S2, designed from tul4 gene, were comparable to the results from previous experiment with fopA - primers set. Investigation of fopA and tul4 primers and hybridization probes properties revealed characteristic Tm (melting temperature) value of the products--61 degrees C and 60 degrees C, respectively. Detection sensitivity was remarkably higher when fopA primers set was used 1 fg/microl, and for tul4 primers set, minimal detectable concentration is 10 fg/microl.

[The substances active against influenza virus. Possibilities and prospects of application]. / Substacje przeciwwirusowe aktywne dla wirusa grypy. Mozliwosci i perspektywy zastosowania.

Influenza, especially pandemic influenza, poses great threat to health and humans life of. Due to the antigenic drift and shift of the influenza virus, there is a constant requirement to accurately adjust contents of the vaccine to current subtype of the virus. As there is always a long period of time between the moment of detection of a new kind of influenza virus till a new vaccine is produced, the only protection for the people are antiviral drugs. Some examples of antiviral compounds that can be used in treatment in near future have been presented. A review of the researches on the substances that are active against influenza viruses has been carried out and their mechanism of action was described. We have taken into account the chemical compounds that seem to be active in the process of virus adsorption; hemagglutinin and neuraminidase inhibitors; M2 ion channel blockers; polymerase, endonuclease, transcriptase, proteine kinase and signaling cascade inhibitors. The potential of oligonucleotide antiviral therapeutics and the substances that are extracted from different plants were presented. The future direction of research were shown.

[Selected research problems of anthrax vaccine development]. / Wybrane kierunki badan nad szczepionkami przeciwko waglikowi.

The threat of bioterrorism with B. anthracis against civilian population is one of major concern. After successful bioterroristic attack in 2001 in US renewed research interest has prompted in the development of new and more effective vaccine against anthrax. There are two licensed vaccines against anthrax--AVA-Bio-Thrax US and UK--sterile culture filtrate prepared by alum precipitation. Both vaccines are based on PA antigen. There are several concerns regarding PA based vaccines. They require six sc injections and yearly booster, high rates of local reaction after vaccination is observed, the immunity is not long lasting, vaccination do not protect animals against different strains of B. anthracis. New strategies in the development of anthrax vaccines have been presented (recombinant PA, subunits vaccine, mutants, conjugated). Using proteomic approaches new antigens have been also identified as candidates for future vaccines. More effective and easy to perform methods of vaccination have been reviewed.

Microbiological analysis of bioaerosols collected from Hospital Emergency Departments and ambulances.

INTRODUCTION AND OBJECTIVE: The goal of the study was a microbiological, qualitative and quantitative analysis of bioaerosol at the workplace of medical personnel (Health Emergency Departments (HEDs), ambulances), and comparative administration offices with an expected neutral occupational exposure to biological agents measured with individual Button Sampler. MATERIAL AND METHODS: Personal sampling was performed with Button Sampler instrument loaded with gelatine filters in 10 HEDs, in 9 ambulances and in 9 offices to assess the occupational biological agents' exposure in air. Sampling was conducted from March until April 2016. Samples were quantitatively assessed for viable and total number of bacteria and fungi. Routine procedures for microbiological diagnostics were implemented. Data were analysed using Kruskal-Wallis and Mann-Whitney statistical tests with α=0.05. P value less than 0.05 were considered significant. RESULTS: At the workplaces assessed, the concentrations of viable microorganisms in HEDs were 1.3×102 - 4.2×103 CFU/m3 for bacteria, 3.4×100 - 8.1×101 CFU/m3 for fungi; in ambulances 1.3×102 - 1.4×103 CFU/m3 (bacteria), 6.7×100 - 6.5×102 CFU/m3 (fungi) and in offices 4.2×101 - 5.0×103 CFU/m3 (bacteria), 0 - 7.9×102 CFU/m3(fungi). In outdoor air, the number of microorganisms reached the level: 1.0×102 - 5.9×102 CFU/m3 for bacteria and 1.5×102 - 8.2×102 CFU/m3 for fungi. The predominant isolated bacteria were Gram-positive cocci. The prevalent fungi species belonged to the genus Aspergillus and Penicillium. CONCLUSIONS: The quantitative assessment of examined indoor air was similar to control outdoor air, and were relatively low. The level of microbiological contamination did not exceed 5×103 CFU/m3 which is recommended as an admissible level in public spaces in Poland.

[The structure and mechanism of action of clostridial neurotoxins]. / Struktura i mechanizm dzialania neurotoksyn bakterii rodzaju Clostridium.

Clostridium botulinum and Clostridium tetani produce highly potent neurotoxins, called botulinum toxins and tetanus toxin, respectively. The clostridial neurotoxins specifically bind to neuronal cells and disrupt neurotransmisser release by cleaving proteins involved in specific vesicle membrane fusion. Each toxin is synthesized as an inactive approximately 150 kDa single-chain protein. The protein is posttranslationally proteolyzed to form the active dichain molecule in which the chains approximately 50 and approximately 100 kDa, remain linked by a disulfide bond. The structural organization is funcionally related to the fact that CNTs intoxicate neurons via four-step mechanism consisting of 1. binding, 2. internalization, 3. membrane translocation, and 4. enzymatic target modification. The L chain is responsible for the intracellular catalitic activity. The NH2-terminal 50-kDa domain of the H chain (HN) is implicated in membrane translocation, whereas the COOH-terminal part (HC) is mainly responsible for neurospecific binding.

[Phage lytic enzymes--new hope in battle against bacterial infections]. / Fagowe enzymy lityczne--nowe nadzieje w walce z zakazeniami bakteryjnymi.

Bacteriophage lytic enzymes are produced during phage replication cycle in bacterial cells. Lysis of bacterial cell wall enables release of virus particles. Bakteriophage enzymes activity are highly specific, therefore they are able to destroy selected bacterial species, also resistant to antibiotics. This creates new possibilities in therapy of bacterial infections.

Utilisation of peptides against microbial infections - a review.

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.

[DNA microarrays--new tool in the identification of biological agents]. / Mikromacierze DNA--nowe narzedzie w wykrywaniu czynników biologicznych.

This article describes the methods of sample labelling and the principles of construction and application of microarrays. The examples of microarrays' application for identification of bioterrorism agents, as well as water and food contaminating bacteria and other selected microorganisms, and also antibiotic resistance testing were presented. Due to the fact that this method allows to identify thousands of genes in one experiment, the microarray assay opens new perspectives in epidemiological studies such as determination of sources of disease outbreaks, detection of new genotypes and subtypes, and examining of the geographical spread of the biological agents.

[Francisella tularensis--feature of pathogen, pathogenesis, diagnostics]. / Francisella tularensis--cechy zarazka, patogeneza, diagnostyka.

Francisella tularensis belongs to the Francisellaceae family. There are four known subspecies of Francisella tularensis: tularensis, holarctica, mediasiatica and novicida. Fully virulent strains possess a capsule, which protects F. tularensis from bactericidal action of serum. The main virulen factors of F. tularensis are 23-kDa cytoplasmatic protein and LPS. F tularensis mechanism of pathogenecity is very unique. F. lularensis affect macrophages using a cytochalasin B intensive pathway. Bacteria live within macrophage in a phagosome. Acidification of the phagosome and acquisition of iron is essential for growth of F. tularensis. An acid pH promotes the release of iron from host-cell transferrin. An acid phosphatase function protein, AcpA, has been identified in F. tularensis. AcpA is capable of inhibiting the respiratory burst. A laboratory diagnostics of tularemia is based on classical microbiology and molecular biology techniques: PCR, nested-PCR, PCR-ELISA, Real-Time - PCR, ALFP, ERIC-PCR, PFGE, LR-REP-PCR and microarray techniques.

[Yersinia pestis pathogenesis and diagnostics]. / Chorobotwórczosc i diagnostyka Yersinia pestis.

Plague is an acute bacterial infection caused by Gram negative organism Yersinia pestis. This bacteria is subdivided into three classical biotypes: Orientalis, Medievalis and Antiqua. Plague is transmitted via flea vectors from rodents to humans and by respiratory droplets from animals to humans or humans to humans. This agent is on the top of the CDC list of "Critical Biological Agents"--category A. It appears to be a good candidate agent for a bioterrorist attack. Type III secretion (TTS) is a mechanism by which Y. pestis communicates with eukaryotic cells by injecting bacterial proteins across cellular membranes into the cytosol of these cells. These bacterial proteins take control of the host cells by hijacking their intracellular machinery. A laboratory diagnostics of plague is based on: staining techniques, culture on media, immunochromatography, hemagglutination, immunofluorescence, ELISA, phage tests and genetical techniques including: PCR, multiplex and nested PCR, real time PCR, VNTR, PFGE, ISBF and Microarray.

Microarrays--new possibilities for detecting biological factors hazardous for humans and animals, and for use in environmental protection.

Both the known biological agents that cause infectious diseases, as well as modified (ABF-Advanced Biological Factors) or new, emerging agents pose a significant diagnostic problem using previously applied methods, both classical, as well as based on molecular biology methods. The latter, such as PCR and real-time PCR, have significant limitations, both quantitative (low capacity), and qualitative (limited number of targets). The article discusses the results of studies on using the microarray method for the identification of viruses (e.g. Orthopoxvirus group, noroviruses, influenza A and B viruses, rhino- and enteroviruses responsible for the FRI (Febrile Respiratory Illness), European bunyaviruses, and SARS-causing viruses), and bacteria (Mycobacterium spp., Yersinia spp., Campylobacter spp., Streptococcus pneumoniae, Salmonella typhi, Salmonella enterica, Staphylococcus aureus, Neisseria meningitidis, Clostridium difficile , Helicobacter pylori), including multiple antibiotic-resistant strains. The method allows for the serotyping and genotyping of bacteria, and is useful in the diagnosis of genetically modified agents. It allows the testing of thousands of genes in one experiment. In addition to diagnosis, it is applicable for gene expression studies, analysis of the function of genes, microorganisms virulence, and allows the detection of even single mutations. The possibility of its operational application in epidemiological surveillance, and in the detection of disease outbreak agents is demonstrated.

[Application of the multiplex PCR and PCR-RFLP method in the identification of the Bacillus anthracis]. / Zastosowanie metody multiplex PCR i PCR-RFLP do identyfikacji Bacillus anthracis.

The aim of this study was to apply the multiplex PCR and PCR-RFLP method for the identification of the B. anthracis strains and to distinguish those bacteria from other members of the Bacillus cereus group. The multiplex PCR method enables to detect the virulence factors, i.e. the toxin and the capsule in B. anthracis strains. To do that, the authors have used 5 primer pairs specific for the fragments of lef, cya, pag genes which are present in the pXO1 plasmid and encode the toxin, the cap gene, which is present in the pXO2 plasmid and encodes the capsule, and the Ba813 chromosomal sequence. Among the four B. anthracis strains examined, three contained two plasmids and the Ba813 chromosomal sequence, while the fourth one contained the pXO1 plasmid only, together and the Ba813 chromosomal sequence. Other bacterial species, belonging to the B. cereus group, were also examined: 6 strains of B. cereus, 4 strains of B. thuringiensis and one strain of B. mycoides. The presence of Ba813 chromosomal sequence has been detected in two B. cereus strains. Neither plasmids nor Ba813 chromosomal sequence have been discovered in other B. cereus, B. thuringiensis and B. mycoides strains. The results of the survey indicate that the Ba813 chromosomal sequence does not occur solely in B. anthracis strains. The PCR-RFLP method with the use of SG-749f and SG-749r primers enabled to demonstrate the presence of DNA sequence (SG-749) in B. anthracis, B. cereus, B. thuringiensis and B. mycoides strains. Restriction analysis with enzyme AluI of the SG-749 sequence, has shown the presence of two DNA fragments at the size of about 90 and 660 bp in all B. anthracis strains. The restriction profile obtained was characteristic for B. anthracis strains and it did not occur in other investigated bacterial species belonging to the B. cereus group. It was not observed even in such B. cereus strains in which the presence of Ba813 sequence was discovered and it enabled to differentiate between B. anthracis strains and other closely related species of the B. cereus group.