Differentiation of Bacillus anthracis and other Bacillus cereus group bacterial strains using multilocus sequence typing method

The study describes the preparation of the phylogenetic differentiation of Bacillus cereus strains. The Bacillus cereus group of bacteria is very important for human and animal health. The multilocus sequence typing scheme has been used to present this group of bacteria’s phylogenetic relationship and structure. The MLST system was established using 60 isolates of B. anthracis, B. cereus sensu stricto, B. thuringiensis, and transitional environment strains of Bacillus spp. As a negative control, five strains of B. subtilis and B. megaterium were used. Primers for amplification and sequencing were designed to target highly conserved internal fragment of seven housekeeping genes: glpF, gmk, ilvD, pta, pur, pycA, and tpi. A total of 22 different sequence types (STs) were distinguished. Analysis of the sequence data showed that all of the Bacillus cereus strains are very closely related. The MLST scheme exhibited a high level of resolution that can be used as an excellent tool for studying the phylogenetic relationship, epidemiology, and population structure of the Bacillus cereus group strains. The MLST method additionally allows us to define the phylogenetic relationship between very closely related strains based on a combination of the sequences of all seven alleles fragments and each of them separately. Thus, this genetic investigation tool is very useful in epidemiological investigation of potential military/ bioterrorist use of B. anthracis

The effect of Propionibacterium acnes on maturation of dendritic cells derived from acne patients' peripherial blood mononuclear cells.

Propionibacterium acnes (P. acnes) has been implicated in the pathogenesis of acne vulgaris which is the most common cutaneous disorder. It has a proinflammatory activity and takes part in immune reactions modulating the Th1/Th2 cellular response. The exposure of dendritic cells (DCs) to whole bacteria, their components, cytokines or other inflammatory stimuli and infectious agents induces differentiation from immature DCs into antigen-presenting mature DCs. The aim of the study was to evaluate the capability of P. acnes to induce the maturation of DCs. We stimulated monocyte derived dendritic cells (Mo-DCs) from acne patients with various concetrations of heat-killed P. acnes (10(6)-10(8) bacteria/ml) cultured from acne lesions. The results showed an increase in CD80+/CD86+/DR+ and CD83+/CD1a+/DR+ cells percentage depending on the concetration of P. acnes. The expression of CD83 and CD80 (shown as the mean fluorescence intensity - MFI) increased with higher concetrations of P. acnes. There were also significant correlations between MFI of CD83, CD80, CD86 and concetration of P. acnes. The study showed that P. acnes in the concetration of 10(8) bacteria/ml is most effective in the induction of Mo-DCs maturation. Futher studies concerning the influence on the function of T cells are needed

The most common etiological factors of conjunctivitis

Conjunctivitis is one of the most common diseases of the anterior segment. It is characterized by redness of the eye, conjunctivital injection, the presence of secretions in the conjunctival sac. The most common symptoms reported by patients include: pain, redness, itching, foreign body sensation and photophobia. Intensifying severe symptoms can lead to difficulties in daily activities. The correct diagnosis of the etiological agent is essential to implement an appropriate treatment and relieve symptoms of the disease

Human infections caused by free-living amoebae

Introduction Among free-living amoebae that are widely distributed in nature only four genera/species are known as agents of human infections: Acanthamoeba spp., Naegleriafowleri, Balamuthia mandrillaris and Sappiniapedata. These amoebae are not well adapted to parasitism, and could exist in the human environment without the need for a host. Infections due to these amoebae, despite low morbidity, are characterized by relatively high mortality rate and pose serious clinical problems. Objectve This review study presents and summarizes current knowledge about infections due to pathogenic and opportunistic free-living amoebae focused on epidemiology, clinical manifestations, diagnosis and treatment based on global literature. State of knowledge All four genera have been recognized as etiologic factors of fatal central nervous system infections and other serious diseases in humans. N. fowleri causes an acute fulminating meningoencephalitis in children and young adults. Acanthamoeba spp. and B.mandrillaris are opportunistic pathogens causing granulomatous amoebic encephalitis and disseminated or localized infections which could affect the skin, sinuses, lungs, adrenals and/or bones. Acanthamoeba spp. is also the main agent of acute eye infection – Acanthamoeba keratitis, mostly in contact lens wearers. However, there is only one recognized case of encephalitis caused by S. pedata. Conclusions Amoebic diseases are difficult to diagnose which leads to delayed treatment, and result in a high mortality rate. Considering those issues, there is an urgent need to draw more attention to this type of diseases

The role of opportunistic Corynebacterium spp. in human infections

Introduction. The non-diphtherial corynebacteria (diphtheroids, “coryneform” bacteria) have been increasingly recognized as causative agents of human infections. Aim. To provide an overview of the role of non-diphtherial Corynebacterium species in human infections. Material and methods. Analysis of the literature data found in the PubMed database. Results. The role of diphtheroids - inherently low-virulent microorganisms considered members of the human microbiota – as potential pathogens has been linked to specific risk factors including immunosuppression, implantation of biomaterials and invasive medical procedures. Their pathogenic potential is primarily associated with frequent multidrug resistance, the ability to adhere to biotic and abiotic surfaces and/or to form biofilm as well as with internalization, intracellular survival and persistence within human cells. The most common infections include bacteremia, sepsis, endocarditis, meningitis, urinary tract infections, respiratory tract infections, wound and skin infections, and endophthalmitis. The leading species are C. jeikeium, C. striatum, C. urealyticum, C. amycolatum, and C. pseudodiphtheriticum. Conclusion. Opportunistic corynebacteria can be responsible for a wide range of infections which can be expected to increase in frequency in the future due to an enlarging population of patients with predisposing risk factors but also due to the increasing problem of antibiotic resistance in this group of bacteria