Search

Lyme disease, as one of tick-borne diseases, has been a current epidemiological problem in Poland and in the world for several years. The proportion of borreliosis infections caused by B. burgdorferi spirochaetes is increasing. Difficulties diagnosing this disease with conventional methods have led to growing molecular biology research aimed at developing improved diagnostic tools. Molecular biology methods include all techniques that allow the detection and analysis of nucleic acids. Among them there are methods based on PCR reaction, molecular typing methods (MLST), new generation sequencing (NGS). The current development of this field gives great research opportunities. With regard to B. burgdorferi spirochete, molecular biology is used to: confirm Lyme borreliosis, identify and type Borreliella spirochetes, detect them in tick vectors or intermediate hosts, as well as to identify co-infections between different Borreliella species and other tick-borne pathogens. They are meant to significantly improve diagnostic analyzes. This paper reviews the current methods used for the detection and identification of B. burgdorferi. Molecular mechanisms for the survival of spirochetes in the host, infection vectors and clinical picture of Lyme disease were also discussed.

Tularemia is an acute, infectious zoonotic disease caused by a smal. aerobic, intracellular, gram-negative bacillus Francisella tularensis. Tularemia was firstly described towards the end of nineteenth century in Japan, however, the name Francisella comes from Edward Francis, an American researcher who in 1911 detected this bacterium in squirrels in Tulare County, California. In Poland tularemia in humans was recognized for the first time in 1949. In the years 1949 to 2009, over 600 tularemia cases were recorded in Poland, with one fatality in 1983. Initial work on the use of F. tularensis as a biological weapon was carried out in the 30s of the twentieth century simultaneously in the United States, Soviet Union and Japan. The natural reservoirs of the micro-organism are rodents and lagomorphs, which can be a source of infection for other animals and humans. Human infection occurs through direct contact with sick animal. inhalation of dust contaminated with feces of sick animals and it takes place mainly in the farms involved in the animal production, to a lesser extent as a result of contaminated food and water.

Human body is a complex system that is affected by a significant number of microscopic organisms called the microbiomes. The dynamic development of science has led to innovative discoveries in the field of microbiology. This in turn has extracted new field, metagenomics, thanks to which it became possible to perform detailed analysis of individual groups of bacteria and to determine their effects on preserving a good health. One of the biggest scientific projects that would investigate the influence of microbiomes on humans is HMP (Human Microbiome Project). As part of it the research is being conducted leading to characterize human microbiome at the level of nucleotide sequence of the entire genomic DNA. The microflora of the skin, oral cavity, respiratory tract, digestive tract (intestines), genitourinary system has an essential role in the homeostasis. In the last year the carried research proved that it is a vital part of the human organism in preserving a good health. Any changes in its composition may lead to systemic diseases. Pathological changes affect the outcome of the interaction within the microflora that includes species of commensal and pathogenic bacteria, as well as immunology and genetics of the host. Metagenomics research will contribute not only to the recognition of new, so far unidentified by the bacteriological methods microorganisms, but most of all they will serve as a basis to understand the relationships between the human organism and in-dwelling microorganisms. Thanks to the development of the metagenomics or the NGS (Next Generation Sequencing) it will be possible to discover new metabolic pathways and bidirectional links of bacteria with human metabolism. This will help in finding new therapeutic methods in the treatment of many noninfectious diseases so far considered as civilization diseases or genetically conditioned.