Age influence on hypersensitivity pneumonitis induced in mice by exposure to Pantoea agglomerans

Hypersensitivity pneumonitis (HP) represents the immunologically mediated lung disease induced by repeated inhalations of a wide variety of certain finely dispersed organic antigens. In susceptible subjects, these inhalations provoke a hypersensitivity reaction characterized by intense inflammation of the terminal bronchioles, the interstitium and the alveolar tree. The inflammation often organizes into granulomas and may progress to pulmonary fibrosis. Our previous work indicated that cell extract of gram-negative bacteria Pantoea agglomerans (SE-PA) causes, in young C57BL/6J mice, pulmonary changes that are very similar to the clinical manifestations of HP in men. The purpose of presented studies was to describe the response of mice immune system while exposed to SE-PA. Particular attention was paid to examine the age influence on SE-PA induced inflammation and fibrosis in lung tissue. We used 3- and 18-month-old C57BL/6J mice. Lung samples were collected from untreated mice and animals exposed to harmful agent for 7 and 28 days. HP development was monitored by histological and biochemical evaluation. Using ELISA tests, we examined concentration of pro- and anti-inflammatory cytokines in lung homogenates. Our study demonstrated again that SE-PA provokes in mice changes typical for the clinical picture of HP, and that successive stages of disease (acute, subacute and chronic) might be obtained by modulation of time exposure. Furthermore, we found that animals' age at the time of sensitization influences the nature of observed changes (cytokine expression pattern) and the final outcome (reaction intensity and scale of fibrosis).

Relationship between COPD and lower socioeconomic status in farmers from South-Eastern Poland (Lublin region)

INTRODUCTION

Lower socioeconomic status is considered to be an independent risk factor of chronic conditions, such as chronic obstructive pulmonary disease (COPD). COPD, one of the major public health problems worldwide, is a chronic inflammatory lung disease of a multifactorial background. COPD morbidity in rural areas has been higher than in urban settings, as apart from the major causative factor, tobacco smoking, the burden of this disease in rural environments is also connected to additional occupational factors (organic dusts). The management of chronic diseases seems to be particularly difficult in rural areas. The aim of the study was to analyze the socioeconomic status of farmers suffering from COPD in comparison to healthy farmers.

METHODS

Thirty farmers with COPD and 34 healthy farmers from the Lublin region (Poland) were investigated based on the area of land they possessed (an indicator used in the health insurance system in Poland to classify farmers). The farmers from five rural communes were selected by general practitioners. Statistical analysis was performed by non-parametric Mann-Whitney U-test for the differences between area of farms. The p < 0.05 level was considered as significant.

RESULTS

Area of land (median: 1.5 ha, 25th-75th percentile: 1.0-4.0) owned by farmers with COPD was significantly lower than area of farms belonging to healthy farmers (median: 7.0 ha, 25th-75th percentile: 3.0-10.0) (p < 0001, Mann-Whitney U-test).

CONCLUSIONS

In rural areas individuals with COPD are characterized by significantly lower socioeconomic status than healthy persons. COPD is a major health problem, especially in rural areas, which may indicate that policy-makers should consider addressing equity in COPD management in rural areas.

Prevalence of tick-borne pathogens at various workplaces in forest exploitation environment

BACKGROUND

The objective of the study was the evaluation of the infection of ticks with pathogenic microorganisms at various workplaces (timber acquisition, forest growing, forest cultivation, forest protection).

MATERIAL AND METHODS

Eight hundred sixty one Ixodes ricinus ticks collected from 4 workplaces were examined for the presence of Borrelia burgdorferi, Anaplasma phagocytophilum and Babesia microti by polymerase chain reaction (PCR). Then, a comparative analysis of the relative density and infection of ticks at individual workplaces was done. In the statistical analysis, Chi2 test, and Pearson's test for correlation were applied.

RESULTS

The differences in infection (15.9-50%) of ticks with B: burgdorferi between the examined workplaces were highly significant, with the highest percentage observed at forest growing. The percentages of infection of ticks with A. phagocytophilum at individual workplaces ranged from 1.1-3.7%, and differences were statistically insignificant. The percentages of infections of ticks with Babesia microti at individual workplaces fluctuated from 3.6-4.4% and differences were also insignificant. Co-infections of ticks with 2 or 3 pathogens were rare.

CONCLUSIONS

Co-infections with B. burgdorferi and B. microti showed a significant relationship with the workplaces, while those with B. burgdorferi and A. phagocytophilum did not show such a dependence. No significant positive correlation was found between the relative density of ticks and the frequencies of infections with B. burgdorferi, A. phagocytophilum and B. microti.

Occurrence of Leptospira DNA in water and soil samples collected in eastern Poland

Leptospira is an important re-emerging zoonotic human pathogen, disseminated by sick and carrier animals, water and soil. Weather calamities, such as flooding or cyclones favour the spreading of these bacteria. To check a potential role of natural water and soil in the persistence and spread of Leptospira on the territory of eastern Poland, 40 samples of natural water and 40 samples of soil were collected from areas exposed to flooding, and 64 samples of natural water and 68 samples of soil were collected from areas not exposed to flooding. Samples of water were taken from various reservoirs (rivers, natural lakes, artificial lakes, canals, ponds, farm wells) and samples of soils were taken at the distance of 1-3 meters from the edge of the reservoirs. The samples were examined for the presence of Leptospira DNA by nested-PCR. Two out of 40 samples of water (5.0%) collected from the area exposed to flooding showed the presence of Leptospira DNA, while all 40 samples of soil from this area were negative. All samples of water and soil (64 and 68, respectively) collected from the areas not exposed to flooding were negative. No significant difference were found between the results obtained in the areas exposed and not exposed to flooding. In conclusion, these results suggest that water and soil have only limited significance in the persistence and dissemination of Leptospira in eastern Poland.

Cathelicidin LL-37 in bronchoalveolar lavage and epithelial lining fluids from healthy individuals and sarcoidosis patients

Sarcoidosis is a granulomatous disease of unknown etiology most often characterized by pulmonary manifestations. Changes in an innate immune system, involving antimicrobial peptides, have been noted during the course of pulmonary sarcoidosis. This study focuses on the level of LL-37 peptide, the only human cathelicidin, additionally characterized by a wide range of pleiotropic activities, in pulmonary sarcoidosis. A cross-sectional study was conducted in groups of 32 patients with sarcoidosis and 12 healthy individuals. Bronchoalveolar lavage fluid (BALF) sampling, followed by LL-37 measurements by mass spectrometry combined with previous immunoaffinity purification, was performed. Based on urea levels, concentrations of LL-37 in epithelial lining fluid (ELF) were calculated. The levels of LL-37 peptide in BALF samples derived from patients with pulmonary sarcoidosis (median: 17.45 pg/ml, 25th-75th percentile: 8.05-28.33 pg/ml) were significantly higher compared to the healthy group (median: 6.38 pg/ml, 25th-75th percentile: 4.90-11.55 pg/ml) (U Mann-Whitney test, p=0.04). Assessment of LL-37 in ELF confirmed the differences across the groups that were observed in BALF. The level of LL-37 in patients with sarcoidosis (median: 2.25 ng/ml, 25th-75th percentile: 1.03-5.06 ng/ml) was again higher compared to healthy individuals (median: 0.62 ng/ml, 25th-75th percentile: 0.43-2.17 ng/ml) (p=0.06, Mann-Whitney U test). The results of this study demonstrate that the level of LL-37 peptide is elevated in pulmonary compartment affected by sarcoidosis. This might have a meaning in the pathomechanism of the disease, especially taking into consideration versatile activity of human cathelicidin revealed in numerous experimental studies during the last years.

Hantavirus RNA was not detected in Dermacentor reticulatus ticks

A total of 190 Dermacentor reticulatus ticks (80 males, 110 females) collected on the territory of Ostrów Lubelski, Suchawa, Zalutyń and Kazimierz Dolny (Lublin Province, eastern Poland) were examined by reverse transcription PCR and nested PCR methods for the presence of hantavirus RNA. None of the examined Dermacentor reticulatus specimens showed the presence of the hantavirus-specific RNA in spite of using two pairs of primers and the clearly positive results obtained with the positive control. Thus, the hypothesis about the possible participation of ticks in the transmission of hantaviruses was not confirmed.

Occurrence of Cryptosporidium oocysts and Giardia cysts in effluent from sewage treatment plant from eastern Poland

Cryptosporidium spp. and Giardia lamblia (synonyms: Giardia duodenalis, Giardia intestinalis) are emerging protozoa causing disease in humans and animals worldwide. These parasites can pose a serious threat to immunocompromised people, for whom the symptoms are more severe and may include abdominal pain, watery diarrhoea, nausea, headaches, malaise, and fever. One of the sources of these parasites can be treated wastewater from wastewater treatment plants (WTPs). Samples of treated wastewater (effluent), each of 10 L volume, were collected from 13 municipal WTPs located in eastern Poland. Cryptosporidium oocysts and Giardia cysts were separated by the immunomagnetic method. The presence and/or concentration of protozoan (oo)cysts in effluent samples were determined by direct immunofluorescent microscopy, nested PCR and Real Time PCR. Viability of (oo)cysts was determined by double-staining with the use of Live/Dead BacLight kit (Invitrogen). Cryptosporidium spp. oocysts were detected in 8 WTPs (61.5%) and Giardia spp. cysts in 11 WTPs (84.6%) by microscopic analysis. Both pathogens were detected in samples from 7 WTPs. Median concentrations of Cryptosporidium and Giardia (oo)cysts in 13 examined samples were 2.2/L and 6.6/L, respectively, while mean concentrations were 28.5/L and 113.6/L, respectively. In positive samples, Cryptosporidium oocysts concentrations ranged from 0.4 - 154.1 oocysts per litre, and Giardia cysts concentrations ranged from 0.7 - 660 cysts per litre. By nested PCR, Giardia DNA was detected in 4 samples of the 13 examined, (30.8%) while Cryptosporidium DNA was never detected. In Real Time PCR, positive results for Giardia were obtained in 5 samples (38.5%) and in none of the samples for Cryptosporidium, with the exception of one equivocal result. Viable (oo)cysts of Cryptosporidium and Giardia were detected in 3 out of 4 samples examined, in the ranges of 12.5 - 60% and 50 - 100% of total (oo)cysts, respectively. In view of our preliminary study, the presence of oocysts and cysts (largely viable) in effluents from WTPs imply a risk of transmission of waterborne protozoan parasites to humans. Therefore, additional wastewater purification procedures are necessary.

Comprehensive rehabilitation in chronic heart failure

Chronic heart failure (CHF) is a complex disease process connected with cardiovascular system as well as other organs and skeletal muscles. In connection with the above, cardiac rehabilitation, consisting of exercise training and diet supplementation, aims at recovery of physical, social and psychic function and removing risk factors influencing the occurrence of circulatory system diseases. Evidence has shown that exercise training in CHF patients, both aerobic and resistance, can increase peak oxygen consumption and exercise capacity, improve NYHA (New York Heart Association) functional class, reduce mortality and improve the quality of life. Evidence suggests that most improvement is due to the effects of training on the peripheral circulation and skeletal muscle, rather than on the heart itself. Exercise training can improve skeletal muscle metabolism, increase blood flow within the active skeletal muscles, increase capillary density, promote the synthesis and release of nitric oxide, improve angiogenesis, and decrease oxidative stress. Physical effort reduces sympathetic arousal and increases parasympathetic arousal, thus reducing cardiac dysrythmia and ischemia. Mitochondria start working harder, as the demand for energy is higher and electron flow provides energy in the form of ATP. Studies have consistently demonstrated that exercise training is safe and has no deleterious effect on central haemodynamics, left ventricular remodeling, systolic or diastolic function, or myocardial metabolism. Taking several supplements that have documented roles in medical therapy, including vitamins B, C and E, coenzyme Q10, alpha-lipoic acid, chromium, omega-3 polyunsaturated fatty acids, L-carnitine, and quercetin, has beneficiary effect on many diseases, including CHF. In our experience, 19 patients with CHF who undertook resistance (weight) training and food supplementation, returned to their normal activities after 4 months, without any complaints.

Study on tick-borne rickettsiae in eastern Poland. I. Prevalence in Dermacentor reticulatus (Acari: Amblyommidae)

Rickettsia spp. transmitted by ticks are classified mostly in the Spotted Fever Group Rickettsiae (SFGR). Numerous species of this group have been identified in Eurasia as emerging pathogens, but still little is known about their occurrence, effects on human health, and co-incidence with other tick-borne pathogens. The aim of the presented study was to determine the prevalence of Rickettsia spp. in adult Dermacentor reticulatus (Acari: Amblyommidae) ticks collected in Lublin province of eastern Poland using the PCR method. The infection rate of D. reticulatus with Rickettsia spp. was 53.0%. All except one rickettsial isolates showed 100% homology with Rickettsia raoultii. A high prevalence of R. raoultii in Dermacentor reticulatus ticks from eastern Poland suggests that the SFGR species should be considered as potential causative agents of tick-borne diseases in this area.

Study on tick-borne rickettsiae in eastern Poland. II. Serological response of the occupationally exposed populations

A group of 150 persons living in the Lublin province of eastern Poland and occupationally exposed to tick bite were examined by the immunoenzymatic ELISA test for the presence of antibodies against tick-borne Spotted Fever Group (SFG) rickettsiae. The group consisted of 75 forestry workers employed in 3 forest inspectorates and 75 agricultural workers living in 2 villages. As a control group, 43 urban dwellers living in the city of Lublin and not occupationally exposed to tick bite were examined. Among 150 persons occupationally exposed to tick bite, the presence of antibodies against SFG rickettsiae was found in 54 (36.0% of the total). In the control group, the frequency of positive findings was only 4.7%, being significantly smaller compared to the exposed group (p=0.0001). Within the exposed group, the percentage of positive results in forestry workers (50.7%) was greater than in agricultural workers (21.3%); the difference was statistically significant (p=0.0002). Also within this group, the frequency of positive findings in males(46.5%) was significantly greater than in females (21.9%) (p=0.0029). In the exposed group, the positive results tended to increase with the age of the examined persons. However, a significant relationship between age and positive findings was found only in forestry workers (χ(2) =14.207, p=0.00264), but not in agricultural workers and total exposed workers. The frequencies of positive results in forestry workers varied significantly depending on place of work (χ(2) =11.271, p=0.00357). Similarly, the difference between the positive reactions in agricultural workers living in 2 villages proved to be significant (34.2% vs. 8.1%; p=0.0074). The obtained results indicate that people occupationally exposed to tick bite and living in the area of eastern Poland where over half of Dermacentor reticulatus ticks harbour SFG rickettsiae, are under significantly increased risk of infection with these rickettsiae.

Leptospirosis--current risk factors connected with human activity and the environment

Leptospirosis is a widespread although recently neglected zoonosis recognized worldwide. The disease seems to be underestimated, especially in countries located in the temperate climatic zone. The presented article concerns the main characteristics of leptospirosis and describes formerly known and recently observed environmental, occupational and recreational risk factors significant in the spreading and pathogenesis of the disease. The aspects of epidemiology significant in the temperate climatic zone are emphasized. The majority of cited articles present cases of the disease reported from Europe or North America. Climatic changes (warming) and extreme weather events such as floods are potential risk factors of leptospirosis. Also, some socio-economic phenomena, such as the intensive migration of people resulting in the transfer of the infections acquired in tropical countries, or worsening of economic status in the cities, increase the probability of disease. Apart from the danger connected with rodents, which are the main vectors of leptospires, occurrence of the disease in dogs and cats can generate a higher risk of infection for humans. Infections may also be acquired during various types of agricultural work and during recreational activities, such as swimming. The results of recent investigations show that ticks are also potential vectors of leptospires. The more frequent emergence of leptospirosis in countries located in the temperate climatic zone emphasize the need to verify knowledge related to the risk of its appearance, and to consider this disease during diagnostic processes.

A small scale survey of Leptospira in mammals from eastern Poland

Samples of 30 dead small mammals each were collected on area 'A' located in eastern Poland and exposed to floods by the Vistula river, and on area 'B', also located in eastern Poland, but not exposed to floods. Kidneys and livers of the mammals were examined by the PCR and nested PCR methods for the presence of Leptospira DNA. From 7 species of small mammals examined, the presence of Leptospira DNA was detected in 2 of them. The prevalence of positive results was greatest in Apodemus agrarius which was the mostly numerous mammal species (14 out of total 39 specimens, 35.9%). The presence of Leptospira DNA was also found in Microtus arvalis (1 out of 1 specimen, 100%), whereas the remaining 5 species (Apodemus flavicollis , Apodemus sylvaticus, Microtus agrestis, Myodes glareolus, Sorex araneus) were negative. No significant difference in the prevalence of positive findings was found between the small mammals from areas 'A' exposed to flooding, compared to those from area 'B' not exposed to flooding (20.0% vs. 30.0%, p=0.3748). The overall positivity of the examined small mammals population from areas 'A' and 'B' was 25.0%. The prevalence of dual positivity (leptospiral DNA found both in kidney and liver) was greater in the mammals from areas exposed to flooding compared to those from areas not exposed to flooding (16.7% vs. 6.7%), but this dependence was also not significant (p=0.2382).

A small-scale survey of hantavirus in mammals from eastern Poland

Samples of 30 dead small mammals each were collected on area 'A' located in eastern Poland which is exposed to flooding by the Vistula river, and on the area 'B', also located in eastern Poland but not exposed to flooding. Kidneys and livers of the mammals were examined by the PCR and nested PCR methods for the presence of hantavirus RNA. Out of 7 species of small mammals examined, the presence of hantaviruses was detected in 4 of them. Hantavirus prevalence was low in Apodemus agrarius (2.6%), the most numerous mammal species, whereas in the remaining 3 positive species (Microtus agrestis, Myodes glareolus, Sorex araneus) this was 12.5-100%. The presence of hantaviruses was detected only in the animals found on area 'A' exposed to flooding, and their prevalence was statistically greater compared to area 'B' not exposed to flooding (16.7% vs. 0%, p=0.0345). The overall positivity of the examined small mammals population from the areas 'A' and 'B' was 8.3%. The sequence analysis of the samples positive for hantavirus proved that the amplified products showed 77-86% homology with the L segment sequence of hantavirus Fusong-Mf-731 isolated from Microtus fortis in China. The presented study is the first to demonstrate the occurrence of hantavirus infection in small mammals from eastern Poland, and the first to demonstrate the significant relationship between flooding and the prevalence of hantaviruses in small mammals.

Cathelicidin LL-37 in bronchoalveolar lavage and epithelial lining fluids from COPD patients and healthy individuals

Innate immunity is currently under scope of interest concerning its role in the development of chronic obstructive pulmonary disease (COPD). Antimicrobial peptides constitute a potent part of this fast response system. Here, we focus on the role of a specific antimicrobial peptide, the only human cathelicidin, the pleiotropic LL-37 peptide, in the development of COPD under clinical conditions. A cross-sectional study was conducted in groups of 43 patients with COPD (previously classified according to GOLD) and 12 healthy individuals. Bronchoalveolar lavage fluid (BALF) sampling, followed by LL-37 measurements by mass spectrometry combined with previous immunoaffinity purification, was performed. Based on urea levels, concentrations of LL-37 in epithelial lining fluid (ELF) were calculated. Additionally, an antimicrobial assay of growth inhibition of two bacterial species, often involved in COPD development mechanisms, by purchased LL-37 was conducted. Altogether, 55 BALF samples were analyzed. LL-37 levels were significantly higher in BALF from patients in early stages of COPD (GOLD I-II) compared to BALFs from healthy individuals. The same was true for ELF. Cathelicidin’s concentration was significantly lower in both BALF and ELF from patients in advanced COPD (GOLD III-IV). The significantly elevated LL-37 levels both in BALF and ELF in patients with COPD at stage GOLD I-II together with reduced levels in advanced (COPD stage III-IV) further supports the innate immunity involvement in COPD pathology and suggests a profound change in non-specific immunity during the disease progression.

Babesia microti in adult Dermacentor reticulatus ticks from eastern Poland

A total of 468 adult Dermacentor reticulatus ticks (298 females and 170 males) collected by flagging in the forests of Lubelskie province, eastern Poland, were analyzed by PCR and nested-PCR for the presence of Babesia microti DNA. In all, 21 ticks (4.5%) were found to be infected with B. microti. The infection rate in females (5.0%) was slightly greater than in males (3.5%). Detection of B. microti for the first time in adult D. reticulatus ticks suggests that this species should be considered as a potential vector of B. microti in Europe.

Seroprevalence of leptospirosis in rural populations inhabiting areas exposed and not exposed to floods in eastern Poland

Blood serum samples collected from randomly selected groups of 100 persons inhabiting rural community 'A' located in eastern Poland and exposed to floods by the Vistula river, and 98 persons inhabiting rural community 'B', also located in eastern Poland, but in the area not exposed to floods were examined by the microscopic agglutination test (MAT) for the presence of antibodies against 18 Leptospira serovars. Positive results showed 3% of serum samples collected from community 'A', while the seroprevalence in community 'B' was 9.2%, being insignificantly higher than in community 'A'. For both examined communities (n=198), a significant positive correlation was found between the prevalence and titer of seropositive response and age of examined people (r=0.145, p=0.042). No significant differences were found between the prevalence of positive reactions in males and females (p>0.05). The reactions with 10 serovars of Leptospira (Australis, Autumnalis, Hebdomadis, Hardjo, Sejroe, Zanoni, Bataviae, Bratislava, Canicola and Grippotyphosa), belonging to 3 species (L. interrogans, L. borgpetersenii, L. kirschneri), were found in the examined communities. From both communities, of 12 persons demonstrating positive results in MAT, 9 showed reaction with one serovar, 2 with two serovars and 1 with three serovars. The highest titers found during the examination did not exceeded 800. In conclusion, our results suggest that there is only a slight, if any, hazard of an leptospirosis epidemic after the flood that afflicted eastern Poland in the year 2010 and the general epidemiological situation of leptospirosis in eastern Poland. Although there does not seem to be any cause for concern, further research is needed.

Risk of Lyme disease at various sites and workplaces of forestry workers in eastern Poland

Knowledge about the seasonal activity of various stages of the Ixodes ricinus tick is of great importance while developing models of the circulation of pathogens transmitted by ticks in a given environment, as well as while evaluating the risk of infection with these pathogens among individuals performing work in this environment. The objectives of the study was determination of the relative activity of Ixodes ricinus ticks occurring at 4 different workplaces of workers employed in one randomly selected forestry inspectorate, and the comparison of this activity to the Borrelia burgdorferi prevalence in ticks collected from the above-mentioned working stands. Ticks were collected by dragging a woollen flag over lower vegetation and litter along the paths and edges of a forest in July and September 2011 at the following sites and workplaces: acquisition of timber, growing of forest, forest cultivation and forest protection. The relative activity (density) of ticks was determined by means of a combined method of single sample and area sampling. A forest area of approximately 100 m(2) was brushed with a flag. The isolates obtained from Ixodes ricinus ticks were examined for the presence of Borrelia burgdorferi sensu lato DNA by polymerase chain reaction, using primers FLA1 and FLA2 specific for the fragment of fla gene sequence. In the statistical analysis, the Mann-Whitney test, χ(2) test and Spearman test were applied. The differences between Ixodes ricinus activity at individual places of work where various biotopes were observed, were not statistically significant. A statistically significant variation in the tick infection rate, depending on work stands, was found for all the tick stages, i.e. for nymphs (χ(2)=76.516, p<0.000001), females (χ(2)=18.832, p<0.000292) and males (χ(2)=69.257, p=0.000001). Nevertheless, the statistical analysis showed the significant difference in total infection rates only between timber acquisition and growing of forest sites (p=0.049), and between growing of forest and forest cultivation sites (p=0.049). The study showed also the lack of relationship between the ticks' activity and Borrelia burgdorferi infection of ticks at individual places and sites of work of forestry workers. In conclusion, forestry workers employed at such stands of work as timber acquisition, growing of forest, forest cultivation and forest protection are nearly at the same risk of Borrelia burgdorferi infection.

Risk of tick-borne diseases in various categories of employment among forestry workers in eastern Poland

Among the zoonotic agents causing occupational diseases, those transmitted by ticks are very important, in particular the spirochetes Borrelia burgdorferi which are the common cause of occupational Lyme borreliosis in forestry and agricultural workers. The objective of this study was an evaluation of the exposure of forestry workers employed at individual workplaces to infection with tick-borne pathogens (especially Borrelia burgdorferi spirochetes), based on epidemiological investigation and serologic tests. Epidemiological studies covered 111 forestry employees from eastern Poland employed in 4 randomly-selected forest inspectorates which replied to questions in the area of epidemiology and prophylaxis of diseases transmitted by ticks. Eighty-two forestry workers employed in one forest inspectorate were examined for the presence of specific anti-Borrelia burgdorferi antibodies. The correlation between individual items of the questionnaire was assessed by Spearman's test. Results of serological tests were assessed by Mann-Whitney test. Statistical analysis of the results indicated that the workers performing manual jobs in the forest are at the greatest risk of tick bite and contraction of tick-borne disease. They are aware of the risk, but use the improper method of removal of ticks with the fingers. Comparisons of the relationship between job category and the results of serologic study, expressed in BBU/ml, revealed that the serologic response was significantly greater in manual workers than in administrative workers (p=0.019). All other comparisons did not produce significant results. Therefore, providing a simple tweezer-like device to forest inspectorates seems to be an effective mean of protection against Lyme borreliosis and other tick-borne diseases.

Efficacy of the detection of Legionella in hot and cold water samples by culture and PCR. II. Examination of native samples from various sources

A total of 123 water samples were examined in parallel by culture and semi-nested PCR for the presence of Legionella. They comprised: 35 samples of hot water distributed by the urban municipal water supply system (MWSS) taken in institutions, 45 samples of hot water distributed by urban MWSS taken in dwellings, 27 samples of cold water distributed by rural MWSS taken in dwellings, and 16 samples of cold well water taken in rural areas. The greatest frequency of the isolation of Legionella by culture (88.6%) was recorded in the samples of hot water from the urban institutions, having been greater compared to all other sources (p<0.001). The frequency of Legionella isolation from hot water in urban dwellings (28.9%) was significantly greater compared to the combined value (2.3%) for cold water from rural MWSS and wells (p<0.001). Strains belonging to Legionella pneumophila serogroups 2-14 predominated in the examined samples, while strains of L. pneumophila serogroup 1 and strains of Legionella spp. (other than L. pneumophila) were 3-fold less numerous. The rates of positive findings in the semi-nested PCR (stage 2) were greater than culture isolations in all kinds of samples, except for urban institutions. The correlation between the culture and PCR results was positive for samples of hot water from urban MWSS (p<0.01), but not for samples of cold water from rural MWSS and wells (p>0.5). A significant correlation was found between rates of PCR-positive results and numbers of Legionella pneumophila serogroups 2-14 strains, but not for other Legionella serogroups or species. In conclusion, our results support the opinion that though PCR cannot be a substitute for the isolation of Legionella by culture, it could be regarded as an useful complementary method.

Efficacy of the detection of Legionella in hot and cold water samples by culture and PCR. I. Standardization of methods

The aim of the present study was: - to compare methods for concentration and isolation of Legionella DNA from water; - to examine the efficacy of various modifications of PCR test (PCR, semi-nested PCR, and real-time PCR) for the detection of known numbers of Legionella pneumophila in water samples artificially contaminated with the strain of this bacterium and in randomly selected samples of environmental water, in parallel with examination by culture. It was found that filtration is much more effective than centrifugation for the concentration of DNA in water samples, and that the Qiamp DNA Mini-Kit is the most efficient for isolation of Legionella DNA from water. The semi-nested PCR and real-time PCR proved to be the most sensitive methods for detection of Legionella DNA in water samples. Both PCR modifications showed a high correlation with recovery of Legionella by culture (p<0.01), while no correlation occurred between the results of one-stage PCR and culture (p>0.1).

Repellents and acaricides as personal protection measures in the prevention of tick-borne diseases

A number of preventive measures for the protection of humans against tick-borne diseases were evaluated. Measures involving the avoidance of tick bites with the use of protective clothing and insect repellents are the simplest and most effective. Repellents are applied directly to the skin or clothing and other fabrics, such as bednets, tents and anti-mosquito screens. Currently, DEET (N,N-diethyl-m-toluamide) is considered the most efficient arthropod repellent reference substance. The registered and recommended active repellent ingredients for skin and/or cloths application, among others, are: DEET, 1-methyl-propyl-2- (hydroxyethyl)-1-piperidinecarboxylate (picaridin), p-menthane-3,8-diol (PMD), ethyl butylactyloaminopropionate ( IR3535), 1S,2S-2-methylpiperidinyl-3-cyclohexene-1-carboxamide (SS220), racemic 2-methylpiperidinyl-3-cyclohexene-1-carboxamide (AI3-37220) and synthethic pyrethroid - 3-phenoxybenzyl-cis-trans-3(2,2 dichlorovinyl)-2,2-dimethylcyclopropancarboxylate (permethrin) - an acaricide with repellent properties. To achieve the protection from tick bites by avoiding attachment and/or engorgement by the arthropod, acaricides with repellent properties, such as synthetic pyrethroid-permethrin are used. This pyrethroid is an acaricide of choice used for clothing impregnation, which is effective for personal protection against all three parasitic stages of western black-legged ticks. Products based on natural compounds, e.g. eugenol from Ocimum basilicum, 2-undecanone originally derived from wild tomato, geraniol - a natural product extracted from plants, and many others, represent an interesting alternative to common synthetic repellents and/or acaricides.