Ticks are recognized as the main vectors and reservoirs of spotted fever group rickettsiae. We searched for the most prevalent Rickettsia spp. in Poland and found R. slovaca and R. helvetica bacteria in ticks in southern and central Poland; R. raoulti was found in ticks in all parts of Poland.

Q fever is a health problem affecting humans and animals worldwide. In Poland, previous studies have pointed to 2 sources of outbreaks of the disease: the importation of infected animals and their products, and natural domestic foci. In the last decade, 5 outbreaks have occurred in cattle farms in south Poland in Malopolskie, Podkarpackie, Opolskie, and Silesian provinces. The aim of this study was to characterize the Q fever foci in Poland. A total of 279 individuals were included. Levels of serum IgM and IgG antibodies to phase I and II C. burnetii antigens were assayed by indirect immunofluorescence method. Bacterial DNA from all specimens were detected with PCR with primer pairs specific to the htpAB-associated repetitive element, and amplicons were sequenced. Infection was recognized in 67 individuals out of 279 tested in all foci. Twenty-five individuals presented clinical symptoms of acute Q fever. DNA of C. burnetii was found in 8 human blood samples obtained from 3 farm workers and 5 family members. The described outbreaks demonstrate that the main source of human infections in Poland is infected cattle.

Q fever is an infectious zoonotic disease characterized by sudden fever, headache, and atypical pneumonia, caused by Coxiella burneti--an obligatory intracellular parasite. Based on phylogenetic analysis of the genes sequences, the classification was changed and C. burnetii species was included to the gamma subgroup of the proteobacteria, Legionellales order and Coxiellaceae family. This analysis showed more than 99% sequence similarity of 16SrRNA gene among the strains isolated in different regions of the world. Q fever is a widespread in the world zoonosis. Its main reservoir in the rural environment are farm animals: cows, sheep, goats, and urban pets such as dogs, cats, rabbits. In acute infection these bacteria are detected in various internal organs such as lungs, liver, spleen, and in excretion in urine, faeces and milk. During childbirth, they occur in large number in the amniotic fluid and placenta. Recently, it has been found that free-living amoeba Acanthamoeba castellani may also be a reservoir of the pathogen. The intra-amoebal location of C. burnetii cells was observed.

Borrelia burgdorferi spirochetes are an infectious agent of Lyme borreliosis. The aim of our studies was to investigate the fate of engulfed B. burgdorferi cells in L-929 mouse fibroblasts and to observe development of intracellular infection in vitro after 2 and 48 h. Electron microscopic studies reveal consecutive stages of B. burgdorferi spirochetes penetration to mouse fibroblasts in vitro. It has been observed, as a first step attachment and engulfment of spirochetes followed by formation of vacuoles. After 48 hours of infection, vacuoles of fibroblastic cells have been seen full of B. burgdorferi bacteria and latter they have been released from infected cells to extracellular space. It can be the evidence that B. burgdorferi multiply intracellulary.