Middle age enhances expression of innate immunity genes in a female mouse model of pulmonary fibrosis

The lungs are highly sensitive to tissue fibrosis, with a clear age-related component. Among the possible triggers of pulmonary fibrosis are repeated inhalations of fine organic particles. How age affects this response, is still far from being fully understood. We examined the impact of middle-age on gene expression in pulmonary fibrosis, using the novel "inhalation challenge set" mouse model. Our results demonstrate that the response of female mice to exposure of Pantoea agglomerans extract primarily involves various immune-related pathways and cell-cell/cell-extracellular matrix interactions. We found that middle-age had a strong effect on the response to the P. agglomerans-induced lung fibrosis, featured by a more rapid response and increased magnitude of expression changes. Genes belonging to innate immunity pathways (such as the TLR signaling and the NK-cell mediated cytotoxicity) were particularly up-regulated in middle-aged animals, suggesting that they may be potential targets for the treatment of pulmonary fibrosis caused by inhalations of organic particles. Our analysis also highlights the relevance of the "inhalation challenge set" mouse model to lung aging and related pathology.

Microbiological characterization of vegetables and their rhizosphere soil in Eastern Poland

The aim of this study was to investigate the bacteriological quality of 5 kinds of vegetables (lettuce, dill, radish, beetroot, carrot) and their rhizosphere soil, originating from conventional farms located in the Lublin Province of Eastern Poland. A total number of 35 samples of fresh vegetables (FV) taken immediately from soil, 35 samples of soil from rhizosphere of these vegetables (SR) and 35 samples of vegetables sold at retail in the markets in Lublin (VR) were examined. The samples were analysed for the content of: aerobic mesophilic bacteria (AMB) grown at 30°C and 37°C, Gram-negative bacteria of Enterobacteriaceae family, faecal coliform (FC) bacteria, Salmonella spp., and Clostridium perfringens. Median AMB values determined at 30°C for FV, SR and VR were 5.27, 5.00, and 5.00 log₁₀ CFU g^-1 , respectively, being significantly greater compared to those recorded at 37°C. The exceeding of the threshold value of 6.0 log₁₀ CFU g^-1 proposed by Gelosa (1998) was noted only in 5 FV samples grown at 30°C (14.3%), and in 3 FV samples grown at 37°C (8.6%). The threshold value was never exceeded in SR and VR samples. Median concentrations of Enterobacteriaceae determined for FV, SR and VR were 4.03, 3.87, and 3.04 log₁₀ CFU g^-1, respectively. Eleven species of Enterobacteriaceae were identified in the FV, SR and VR samples. The percent of samples containing Escherichia coli was greatest for VR (22.9%), smaller for FV (17.1%) and smallest for SR (5.7%). The median concentrations of the faecal coliform bacteria (FC), determined by culture at 44°C, were low, amounting to 1.000 log₁₀ CFU g^-1 for FV and SR and 0.00 for VR. All examined vegetable and soil samples tested negative for the presence of Salmonella. The median concentrations of Clostridium perfringens were low, amounting to 0.00 log₁₀ CFU g^-1 for all categories of samples. This bacterium was relatively common in soil samples with the prevalence of 40.0%, but very rare in vegetable samples (occurring in 5.7% of FV and in none of VR samples). In conclusion, the results of the present study generally indicate that the microbiological quality of Polish vegetables grown on conventional farms is satisfactory and safe for consumers.

Comparison of the efficiency of two commercial kits - ELFA and Western blot in estimating the phase of Toxoplasma gondii infection in pregnant women

Sera of 89 pregnant women were selected according to the results of ELFA IgM, IgG and avidity IgG, and tested with commercial tests IgM, IgG and avidity IgG Western Blot (WB) to compare the efficacy of both techniques in determining the phase of T. gondii infection. In total, 81 of 89 tested sera (91.0%) were classified as positive, both in the ELFA and WB tests for the presence of anti-Toxoplasma antibodies of class IgG, indicating a past infection, while the prevalence of anti-Toxoplasma positive reactions associated with the antibodies of class IgM indicating a recent infection was much lower - 31.5% and 20.2%, respectively. Sera of 81 women were also tested in the ELFA and WB tests for avidity, e.g. ability of forming high-molecular IgG antibody complexes. Low or medium results in these tests (in this study all classified as low), indicating a recent infection, were detected by ELFA and WB in 22.2% and 45.7% of the total examined samples, respectively. The Spearman's rank test for correlation, performed for recognition of quantitative data of the ELFA and WB tests (index, units or points), revealed a highly significant correlation between the ELFA and WB tests for homologous classes of antibodies, both for IgM and IgG (p<0.00001). In contrast, the ELFA and WB tests for detection of anti-Toxoplasma IgM antibodies were not correlated with the ELFA and WB tests for detection of anti-Toxoplasma IgG antibodies (p>0.05), except for the WB test for IgM antibodies, which showed a significant correlation with the ELFA test for IgG antibodies (p<0.01). A highly significant negative correlation between the ELFA and WB test for IgM antibodies and ELFA and WB tests for IgG avidity was demonstrated (p<0.01), except for a relationship between the WB test for IgM and WB for avidity, which was not significant. Such negative correlations are theoretically expected, as strong complexes with the participation of IgG antibodies are absent in the early phase of toxoplasmosis when early antibodies of IgM class are present. Summarizing, this study indicates the high usefulness of the commercial ELFA and WB tests in serodiagnostics of toxoplasmosis in pregnant women. Special attention should be paid to parallel detection of IgM antibodies and low values in the ELFA and WB tests for IgG avidity, which indicates a recent infection which may be associated with a clinical form of congenital toxoplasmosis and damage to the foetus.

Structure-Bioactivity Relationship of Chitin Derivatives—Part I: The Effect of Solid Chitin Derivatives on Blood Coagulation

Chemical modification of chitin led to a series of derivatives: chi tosan, N-acetylchitosan, monoacetylchitin, dibutyrylchitin, chitosan acetate, chitosan butyrate, chitosan citrate and chitosan-poly(acrylic acid) complex. These were used to coat glass surfaces and studied with respect to their wetting properties and thrombogenic characteristics. All materials had much better wetting properties than siliconized glass surface The surface tension of these chitin derivatives was calculated and found to correlate with substrate throm bogenicity. The clotting time of whole blood depended on the chemical modification of the polyaminosaccharide structure and was significantly higher than the silicone surface. Gamma radiation treatment of chitosan led to a decrease in intrinsic viscosity but a small influence on the clotting time of blood in contact with the polymer samples. Solid coatings of acetate, butyrate and citrate salts of chitosan exhibited the greatest thromboresistance of all the investigated derivatives. The kaolin clotting time of plasma shaken in tubes coated with the salts did not show any leachable substances that affected blood coagulation factors except for chitosan-poly(acrylic acid) complex.

Pantoea agglomerans: a mysterious bacterium of evil and good. Part III. Deleterious effects: infections of humans, animals and plants

Pantoea agglomerans, a bacterium associated with plants, is not an obligate infectious agent in humans. However, it could be a cause of opportunistic human infections, mostly by wound infection with plant material, or as a hospital-acquired infection, mostly in immunocompromised individuals. Wound infection with P. agglomerans usually follow piercing or laceration of skin with a plant thorn, wooden splinter or other plant material and subsequent inoculation of the plant-residing bacteria, mostly during performing of agricultural occupations and gardening, or children playing. Septic arthritis or synovitis appears as a common clinical outcome of exogenous infection with P. agglomerans, others include endophthalmitis, periostitis, endocarditis and osteomyelitis. Another major reason for clinical infection with P. agglomerans is exposure of hospitalized, often immunodeficient individuals to medical equipment or fluids contaminated with this bacterium. Epidemics of nosocomial septicemia with fatal cases have been described in several countries, both in adult and paediatric patients. In most cases, however, the clinical course of the hospital-acquired disease was mild and application of the proper antibiotic treatment led to full recovery. Compared to humans, there are only few reports on infectious diseases caused by Pantoea agglomerans in vertebrate animals. This species has been identified as a possible cause of equine abortion and placentitis and a haemorrhagic disease in dolphin fish (Coryphaena hippurus). P. agglomerans strains occur commonly, usually as symbionts, in insects and other arthropods. Pantoea agglomerans usually occurs in plants as an epi- or endophytic symbiont, often as mutualist. Nevertheless, this species has also also been identified as a cause of diseases in a range of cultivable plants, such as cotton, sweet onion, rice, maize, sorghum, bamboo, walnut, an ornamental plant called Chinese taro (Alocasia cucullata), and a grass called onion couch (Arrhenatherum elatius). Some plant-pathogenic strains of P. agglomerans are tumourigenic, inducing gall formation on table beet, an ornamental plant gypsophila (Gypsophila paniculata), wisteria, Douglas-fir and cranberry. Recently, a Pantoea species closely related to P. agglomerans has been identified as a cause of bacterial blight disease in the edible mushroom Pleurotus eryngii cultivated in China. The genetically governed determinants of plant pathogenicity in Pantoea agglomerans include such mechanisms as the hypersensitive response and pathogenicity (hrp) system, phytohormones, the quorum-sensing (QS) feedback system and type III secretion system (T3SS) injecting the effector proteins into the cytosol of a plant cell.

Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects

Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others) which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as 'Immunopotentiator from Pantoea agglomerans 1 (IP-PA1)' reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of plant resistance. Its use as a biocontrol agent permits the decrease of pesticide doses, being a healthy and environmental-friendly procedure. The application of the preparations of this bacterium efficiently protects the stored pome, stone and citrus fruits against invasion of moulds. P. agglomerans strains associated with both rhizosphere and plant tissues (as endophytes) efficiently promote the growth of many plants, including rice and wheat, which are the staple food for the majority of mankind. The promotion mechanisms are diverse and include fixation of atmospheric nitrogen, production of phytohormones, as well as degradation of phytate and phosphate solubilizing which makes the soil phosphorus available for plants. Accordingly, P. agglomerans is regarded as an ideal candidate for an environmental-friendly bioinoculant replacing chemical fertilizers. It has been documented that the Pantoea strains show biodegradation activity on various chemical pollutants of soil and water, including petroleum hydrocarbons and toxic metals. P. agglomerans prevents the penetration of harmful industrial contaminants into deeper parts of soil by biofilm formation, and has an ability to produce hydrogen from waste. Thus, this bacterium appears as a valuable bioremediator which, in some cases, may be acquired as a cheap form of energy. In conclusion, in spite of the proven pathologic role of P. agglomerans in causing occupational diseases of allergic and/or immunotoxic background and accidental infections, the beneficial traits of this species, and of related species of Pantoea genus, are of great value for potential use in many areas of biotechnology. Hence, any restrictions on the use of these organisms and their products should be declined, providing safety precautions at work with the Pantoea biopreparations are maintained.

Infections and mixed infections with the selected species of Borrelia burgdorferi sensu lato complex in Ixodes ricinus ticks collected in eastern Poland: a significant increase in the course of 5 years

In the years 2008-2009 and 2013-2014, 1620 and 1500 questing Ixodes ricinus ticks, respectively, were examined on the territory of the Lublin province (eastern Poland). The presence of three pathogenic species causing Lyme disease was investigated: Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii. The proportion of I. ricinus ticks infected with B. burgdorferi sensu lato showed a highly significant increase between 2008-2009 and 2013-2014, from 6.0 to 15.3%. A significant increase was noted with regard to all types of infections with individual species: single (4.7-7.8%), dual (1.2-6.6%), and triple (0.1-0.9%). When expressed as the percent of all infections, the frequency of mixed infections increased from 21.4 to 49.2%. Statistical analysis performed with two methods (by calculating of odds ratios and by Fisher's exact test) showed that the frequencies of mixed infections in most cases proved to be significantly greater than expected. The strongest associations were found between B. burgdorferi s. s. and B. afzelii, and between B. burgdorferi s. s. and B. garinii. They appeared to be highly significant (P < 0.0001) when assessed by two methods for 2013-2014, and for the sum of findings for both time periods. The proportions of the individual species detected in the mixed infections in 2008-2009 and 2013-2014 revealed highly significant increases for B. burgdorferi s. s. and B. garinii (from 33.9 to 71.1% and from 18.2 to 82.9%, respectively), and an insignificant decrease for B. afzelii (from 51.4 to 41.6%). The proportions of the species B. burgdorferi s. s., B. afzelii and B. garinii (with combined single and mixed infections) for 2008-2009 and 2013-2014 were: 51.2/44.0 %, 30.6/24.9% and 18.2/31.1%, respectively. In conclusion, our results seem to indicate the detrimental trend of the increasing infection rate of I. ricinus ticks with B. burgdorferi s. l. in eastern Poland, and dramatic enhancement of mixed infections with individual species, which may result in mixed infections of humans and exacerbation of the clinical course of Lyme disease cases on the studied area.

Pantoea agglomerans: a mysterious bacterium of evil and good. Part II--Deleterious effects: Dust-borne endotoxins and allergens--focus on grain dust, other agricultural dusts and wood dust

Pantoea agglomerans, a Gram-negative bacterium developing in a variety of plants as epiphyte or endophyte is particularly common in grain and grain dust, and has been identified by an interdisciplinary group from Lublin, eastern Poland, as a causative agent of work-related diseases associated with exposure to grain dust and other agricultural dusts. The concentration of P. agglomerans in grain as well as in the settled grain and flour dust was found to be high, ranging from 10(4)-10(8) CFU/g, while in the air polluted with grain or flour dust it ranged from 10(3)-10(5) CFU/m(3) and formed 73.2-96% of the total airborne Gram-negative bacteria. The concentration of P. agglomerans was also relatively high in the air of the facilities processing herbs and other plant materials, while it was lower in animal farms and in wood processing facilities. Pantoea agglomerans produces a biologically-potent endotoxin (cell wall lipopolysaccharide, LPS). The significant part of this endotoxin occurs in dusts in the form of virus-sized globular nanoparticles measuring 10-50 nm that could be described as the 'endotoxin super-macromolecules'. A highly significant relationship was found (R=0.804, P=0.000927) between the concentration of the viable P. agglomerans in the air of various agricultural and wood industry settings and the concentration of bacterial endotoxin in the air, as assessed by the Limulus test. Although this result may be interfered by the presence of endotoxin produced by other Gram-negative species, it unequivocally suggests the primary role of the P. agglomerans endotoxin as an adverse agent in the agricultural working environment, causing toxic pneumonitis (ODTS). Numerous experiments by the inhalation exposure of animals to various extracts of P. agglomerans strains isolated from grain dust, including endotoxin isolated with trichloroacetic acid (LPS-TCA), endotoxin nanoparticles isolated in sucrose gradient (VECN), and mixture of proteins and endotoxin obtained by extraction of bacterial mass in saline (CA-S), showed the ability of these extracts to evoke inflammatory and fibrotic changes in the lungs, to stimulate alveolar macrophages to produce superoxide anion (O2(-)), interleukin-1 (IL-1) and chemotactic factors for other macrophages and neutrophils, and to increase the pulmonary concentrations of toll-like receptors and chemokines. The most potent properties showed the CA-S which may be attributed to the allergenic properties of P. agglomerans proteins enhanced by the presence of the autologous endotoxin. The results of these experiments are in accord with the clinical studies which revealed a high reactivity of the agricultural and grain industry workers to allergenic extracts of P. agglomerans, and the presence in these populations of hypersensitivity pneumonitis and asthma cases caused by this bacterium. P. agglomerans has been also identified as a potential causative agent of allergic dermatitis in farmers and of allergic pulmonary disorders in cattle. In conclusion, similar to the cotton industry, also in the grain industry and in agriculture, Pantoea agglomerans should be regarded as one of the major causative agents of work-related diseases, caused by the adverse effects of protein allergens and endotoxin produced by this bacterium.

Toxoplasma gondii (Nicolle et Manceaux, 1908) detected in Dermacentor reticulatus (Fabricius) (Ixodidae)

The aim of the present work was to determine whether Dermacentor reticulatus (Fabricius), tick species common in eastern Poland could be infected with Toxoplasma gondii (Nicolle et Manceaux, 1908). A total of 664 unfed D. reticulatus ticks were collected from six localities of Lublin province (eastern Poland) within the framework of study for the presence of bacterial, viral and parasitological infections, with use of PCR and confirmed by sequencing analysis. The prevalence of T. gondii DNA of B1 gene in the total examined D. reticulatus ticks was 3.2%. The infection varies greatly depending on the locality of tick collection (0-16.7%). Preliminary identification of clonal type (I or II/III) by Restriction Fragments Length Polymorphism PCR (RFLP-PCR) with use B1 gene showed that all isolates of T. gondii belonged to type I. RFLP analysis using genetic markers SAG1, 5'-SAG2, 3'-SAG2, SAG3, and GRA6 on B1-positive samples showed that only a single isolate proved to be type I with all five markers, another type was classified to type I according to four markers, while another five isolates had only type I alleles at GRA6, which cannot be regarded as type I confirmation. It must be pointed out that the used DNA isolation method by boiling with ammonium hydroxide enables to receive the total DNA from ticks, but may be not quite suitable for genotyping. In conclusion, this study indicates that besides Ixodes ricinus (Linnaeus), also D. reticulatus should be considered as a potential vector of T. gondii. The presumption of tick-borne transmission as an alternative pathway of disease spreading could well explain the high prevalence of toxoplasmosis among the herbivorous mammals and birds. However, this hypothesis needs verification by further experimental and ecological studies.

Evaluation of reactivity to Echinococcus spp. among rural inhabitants in Poland

A group of 172 rural inhabitants from eastern Poland (68 males and 104 females, mean age 49.0 ± 12.0 years) was examined for the presence of antibodies against Echinococcus granulosus and Echinococcus multilocularis. A population of 38 healthy urban dwellers from the city of Lublin (17 males and 21 females, mean age 36.2 ± 9.6 years) were examined as a control group. Sera of 22 rural inhabitants (12.8%) reacted positively to Echinococcus granulosus hydatid fluid antigen in the screening test. A cross-reactivity was observed with two serum samples that tested positive in ELISA for E. granulosus. Three serum samples were tested positive for E. multilocularis using the Em2plus ELISA assay and also positive for Western blot. None of the members of control group showed the presence of a seropositive reaction to Echinococcus spp. The reactivity to Echinococcus spp. among rural inhabitants decreased with age and this correlation was statistically significant (R = -0.197151, p = 0.009535). The percentage of positive findings was the highest (50.0%) in the youngest age group (14-20). No significant correlations were found between responses to interview questions (possession of domestic and farm animals, contact with wild animals, eating unwashed berries, drinking unboiled water) and the presence of seropositive reactions to Echinococcus spp. The presented results seem to indicate that echinococcosis is still a current problem in Poland that should not be neglected and, moreover, indicates the need for improvement in the routine laboratory diagnostics of Echinococcus spp. by standardizing the ELISA and Western blot tests.

Prevalence and molecular typing of Giardia duodenalis in wildlife from eastern Poland

Faecal samples from 162 wild animals were collected from 32 distinct sites of Łęczyńsko-Włodawskie Lakeland (eastern Poland). The presence of Giardia duodenalis (Stiles, 1902) was assessed by a Direct Fluorescence Assay (DFA) and by Polymerase Chain Reaction (PCR) and sequencing of a fragment of the beta-giardin gene. DFA showed the presence of cysts of G. duodenalis in 12 of 162 faecal samples (7%), namely in four wild boars (15%), four foxes (19%), two roe deer (4%), and two wolves (29%). PCR identified 34 of the 162 (21%) samples as positive, including 11 wild boars (41%), five red deer (18%), 11 roe deer (23%), four moose (17%), two wolves (29%) and a single sample from the European badger. Thus, PCR detected a significantly higher number of infection than DFA (P = 0.0005). However, 14 of 34 PCR products could not be sequenced because of their insufficient amount; the low number of cysts, poor conservation of the faeces or presence of PCR inhibitors may have contributed to weak DNA amplification. Sequence analysis of the remaining 20 products showed the presence of assemblage B in wild boars, red deer and roe deer, whereas samples from wolves were identified as assemblage D. This is the first detection of assemblage B in wild boars and deer. As assemblage B has zoonotic potential, wild animals from eastern Poland may act as reservoirs of cysts of G. duodenalis infectious for humans.

Potential role of beavers (Castor fiber) in contamination of water in the Masurian Lake District (north-eastern Poland) with protozoan parasites Cryptosporidium spp. and Giardia duodenalis

The purpose of this study was to assess the possible influence of beavers on the contamination of lake water with zoonotic parasites Giardia duodenalis and Cryptosporidium spp., with respect to the risk to human health. A total of 79 water samples were taken around the habitats of beavers from 14 localities situated in the recreational Masurian Lake District (north-eastern Poland). Water was sampled in the spring and autumn seasons, at different distances from beavers’ lodges (0-2, 10, 30, and 50 m). The samples were examined for the presence of (oo)cysts of zoonotic protozoa Giardia duodenalis and Cryptosporidium spp. by direct fluorescence assay (DFA) and by nested and real time PCR. By DFA, the presence of Giardia cysts was found in 36 samples (45.6%) and the presence of Cryptosporidium oocysts in 26 samples (32.9%). Numbers of Giardia cysts, Cryptosporidium oocysts, and summarised (oo)cysts of both parasites showed a significant variation depending on locality. The numbers of Giardia cysts significantly decreased with the distance from beavers’ lodges while the numbers of Cryptosporidium oocysts did not show such dependence. The amount of Giardia cysts in samples collected in spring was approximately 3 times higher than in autumn. Conversely, a larger number of Cryptosporidium oocysts were detected in samples collected in autumn than in spring. By PCR, Giardia DNA was found in 38 samples (48.1%) whereas DNA of Cryptosporidium was found in only 7 samples (8.9%). Eleven Giardia isolates were subjected to phylogenetic analysis by restriction fragment length polymorphism PCR or sequencing which evidenced their belonging to zoonotic assemblages: A (3 isolates) and B (8 isolates). In conclusion, water in the vicinity of beavers’ lodges in the tested region was markedly contaminated with (oo)cysts of Giardia duodenalis and Cryptosporidium spp., which confirms the potential role of beavers as a reservoir of these parasites and indicates a need for implementation of appropriate preventive measures to protect tourists’ health.

Bartonella henselae in eastern Poland: the relationship between tick infection rates and the serological response of individuals occupationally exposed to tick bites

To explore the potential role of Ixodes ricinus as the presumed vector of Bartonella henselae in eastern Poland, ticks collected in various geographic locations were examined for the presence of B. henselae, and the results were matched against the prevalence of anti-B. henselae antibodies in individuals occupationally exposed to tick bites. The presence of Bartonella DNA was investigated by PCR in a total of 1,603 unfed Ixodes ricinus ticks. The presence of IgG antibodies against B. henselae was investigated in serum samples from 332 people occupationally exposed to tick bites (94 farmers and 238 forestry workers). The total prevalence of B. henselae in ticks was 1.7%; the infection rates in males (3.1%) and females (2.7%) were nearly ten times greater than in nymphs (0.3%). The prevalence of seropositive results in the risk group (30.4%), farmers (27.7%) and forestry workers (31.5%), was significantly greater compared to the control group (8.9%). The results showed a weak positive correlation between the degree of infection of ticks and humans living in the same geographic region. The lack of a direct relationship indicates that exposure to tick bites is only one of the factors contributing to the significant preponderance of a seropositive response to B. henselae in the forestry workers and farmers over the control group. Other factors must be considered, such as contact with cats, which are popular domestic animals in Polish villages, and exposure to cat fleas.

Cathelicidin related antimicrobial peptide, laminin, Toll-like receptors and chemokines levels in experimental hypersensitivity pneumonitis in mice

INTRODUCTION

Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by unresolved inflammation and tissue repair pathologies triggered by repeated organic dust exposure. The aim of the study was to investigate changes in levels of the cathelicidin related antimicrobial peptide (CRAMP), laminin (LAM-A1), selected Toll-like receptors (TLR) and chemokines in experimental HP in mice.

MATERIALS AND METHODS

Three and 18-month-old female C57BL/6J mice underwent inhalations of the saline extract of Pantoea agglomerans cells, Gram-negative bacterium common in organic dust and known for its pathogenic impact. The inhalations were repeated daily (28 days). ELISA was used for measuring in lung tissue homogenates concentration of CRAMP, LAM-A1, TLR2, TLR4, TLR8, CXCL9 (chemokine [C-X-C motif] ligand) and CXCL10.

RESULTS

Levels of TLR2, TLR4 and CXCL9 were significantly higher in both young and old mice lungs already after 7 days of inhalations, while significant increase of LAM-A1 and CXCL10 was noted after 28 days, compared to untreated samples. TLR8 level was significantly augmented only in young mice. Only CRAMP level significantly declined. Significantly higher TLR8 and CXCL9 concentration in untreated samples were noted in old animals compared to young ones.

CONCLUSION

Significant alterations of the examined factors levels indicate their role in HP pathogenesis.

Occurrence of Francisella spp. in Dermacentor reticulatus and Ixodes ricinus ticks collected in eastern Poland

A total of 530 questing Dermacentor reticulatus ticks and 861 questing Ixodes ricinus ticks were collected from Lublin province (eastern Poland) and examined for the presence of Francisella by PCR for 16S rRNA (rrs) and tul4 genes. Only one female D. reticulatus tick out of 530 examined (0.2%) was infected with Francisella tularensis subspecies holarctica, as determined by PCR of the rrs gene. None of 861 I. ricinus ticks were infected with F. tularensis. In contrast, the presence of Francisella-like endosymbionts (FLEs) was detected in more than half of the D. reticulatus ticks (50.4%) and 0.8% of the I. ricinus ticks. The nucleotide sequences of the FLEs detected in D. reticulatus exhibited 100% homology with the nucleotide sequence of the FLE strain FDrH detected in Hungary in D. reticulatus. In conclusion, our results suggest a low contribution of D. reticulatus and I. ricinus ticks to the circulation of F. tularensis in eastern Poland. This finding, however, needs to be confirmed by further studies in other areas. Our study confirmed the common infection of D. reticulatus with Francisella-like endosymbionts (FLEs) of unknown pathogenic potential and revealed, for the first time, a low grade of infection of I. ricinus with FLEs.

Spiroplasma - an emerging arthropod-borne pathogen?

Spiroplasma is a genus of wall-less, low-GC, small Gram-positive bacteria of the internal contractile cytoskeleton, with helical morphology and motility. The genus is classified within the class Mollicutes. Spiroplasma / host interactions can be classified as commensal, pathogenic or mutualist. The majority of spiroplasmas are found to be commensals of insects, arachnids, crustaceans or plants, whereas a small number of species are pathogens of plants, insects, and crustaceans. Insects are particularly rich sources of spiroplasmas. The bacteria are common in haematophagous arthropods: deerflies, horseflies, mosquitoes, and in ticks, where they may occur abundantly in salivary glands. The ability of spiroplasmas to propagate in rodents was experimentally proven, and Spiroplasma infections have been reported recently in humans. Some authors have purported an etiological role of Spiroplasma in causing transmissible spongiform encephalopathies (TSEs), but convincing proof is lacking. The possibility for humans and other vertebrates to be infected with Spiroplasma spp. in natural conditions is largely unknown, as well as the possibility of the transmission of these bacteria by ticks and haematophagous insects. Nevertheless, in the light of new data, such possibilities cannot be excluded.

Epidemiological survey in Łęczyńsko-Włodawskie Lake District of eastern Poland reveals new evidence of zoonotic potential of Giardia intestinalis

Faecal samples from 297 farm animals were collected from 18 households in distinct sites of the Łęczyńsko-Włodawskie Lake District of eastern Poland. They included samples from 86 cattle (Bos taurus), 84 pigs (Sus scrofa f. domestica), 81 sheep (Ovis aries), 10 horses (Equus caballus), and 36 dogs (Canis lupus familiaris). The samples were examined for the presence of Giardia intestinalis by the Direct Fluorescence Assay (DFA) and semi-nested PCR. All amplicons were sequenced on both strands. By DFA, cysts of Giardia spp. were detected in 66 of 297 faecal samples (22.2%). Positive specimens for Giardia spp. were derived from 29.8% of examined pigs, 21.0% of sheep, 18.6% of cattle, 10% of horses, and 19.4% of dogs. Based on the detection of the β-giardin gene by PCR, 39 (13.1%) of the 297 examined samples were recognized as positive. Detection of the presence of Giardia cysts by DFA test was overall significantly higher compared to PCR (p=0.0045). By PCR, Giardia was found in 28.1% of sheep, 11.6% of cattle, 10% of horses, 9.5% of pigs and 5.6% of dogs. Partial β-giardin gene sequences were obtained for 73.7% of the PCR positive samples. From sequenced samples derived from the studied animals, Giardia were identified as assemblage A (8 samples), B (1 sample) and E (18 samples). As assemblages A and B may be zoonotic, the farm animals living in eastern Poland could be regarded as a potential source of Giardia infection for humans.

Age influence on mice lung tissue response to Aspergillus fumigatus chronic exposure

INTRODUCTION AND OBJECTIVE

Exposure to conidia of Aspergillus fumigatus was described as a causative factor of a number of the respiratory system diseases, including asthma, chronic eosinophilic pneumonia, hypersensitivity pneumonitis and bronchopulmonary aspergillosis. The study investigates the effects of the repeated exposure to A. fumigatus in mice pulmonary compartment. Our work tackles two, so far insufficiently addressed, important aspects of interaction between affected organism and A. fumigatus: 1) recurrent character of exposure (characteristic for pathomechanism of the abovementioned disease states) and 2) impact of aging, potentially important for the differentiation response to an antigen.

MATERIALS AND METHODS

In order to dissect alterations of the immune system involved with both aging and chronic exposure to A. fumigatus, we used 3- and 18-month-old C57BL/6J mice exposed to repeated A. fumigatus inhalations for 7 and 28 days. Changes in lung tissue were monitored by histological and biochemical evaluation. Concentration of pro- and anti-inflammatory cytokines in lung homogenates was assessed by ELISA tests.

RESULTS AND CONCLUSIONS

Our study demonstrated that chronic inflammation in pulmonary compartment, characterized by the significant increase of proinflammatory cytokines (IL1, IL6, IL10) levels, was the dominant feature of mice response to repeated A. fumigatus inhalations. The pattern of cytokines' profile in the course of exposure was similar in both age groups, however in old mice the growth of the cytokines' levels was more pronounced (especially in case of IL1).

Pantoea agglomerans: a marvelous bacterium of evil and good.Part I. Deleterious effects: Dust-borne endotoxins and allergens - focus on cotton dust

The ubiquitous Gram-negative bacterium Pantoea agglomerans (synonyms: Enterobacter agglomerans, Erwinia herbicola) is known both as an epiphytic microbe developing on the surface of plants and as an endophytic organism living inside the plants. The bacterium occurs also abundantly in plant and animal products, in the body of arthropods and other animals, in water, soil, dust and air, and occasionally in humans. From the human viewpoint, the role of this organism is ambiguous, both deleterious and beneficial: on one side it causes disorders in people exposed to inhalation of organic dusts and diseases of crops, and on the other side it produces substances effective in the treatment of cancer and other diseases of humans and animals, suppresses the development of various plant pathogens, promotes plant growth, and appears as a potentially efficient biofertilizer and bioremediator. P. agglomerans was identified as a predominant bacterium on cotton plant grown all over the world, usually as an epiphyte, rarely as pathogen. It is particularly numerous on cotton bract after senescence. During processing of cotton in mills, bacteria and their products are released with cotton dust into air and are inhaled by workers, causing respiratory and general disorders, usually defined as byssinosis. The most adverse substance is endotoxin, a heteropolymer macromolecule present in the outermost part of the cell wall, consisting of lipopolysaccharide (LPS) as a major constituent, phospholipids and protein. The numerous experiments carried out in last quarter of XXth century on laboratory animals and human volunteers supported a convincing evidence that the inhaled endotoxin produced by P. agglomerans causes numerous pathologic effects similar to those elicited by cotton dust, such as influx of free lung cells into airways and activation of alveolar macrophages which secrete mediators (prostaglandins, platelet-activating factor, interleukin-1, tumor necrosis factor) that cause accumulation of platelets in pulmonary capillaries initiating an acute and chronic inflammation resulting in endothelial cell damage and extravasation of cells and fluids into the lung interstitium. These changes cause bronchoconstriction, the decrement of lung function expressed as reduction of forced expiratory volume in one second (FEV1) and/or diffusion capacity, increase in the airway hyperreactivity and subjective symptoms such as fever, airway irritation and chest tightness. The conclusions from these experiments, performed mostly 2-3 decades ago, did not loose their actuality until recently as so far no other cotton dust component was identified as a more important work-related hazard than bacterial endotoxin. Though also other microbial and plant constituents are considered as potential causative agents of byssinosis, the endotoxin produced by Pantoea agglomerans and other Gram-negative bacteria present in cotton dust is still regarded as a major cause of this mysterious disease.

Relationship between concentrations of microbiological agents in the air of agricultural settings and occurrence of work-related symptoms in exposed persons

For assessment of the dose-response relationship between concentrations of microbial agents in the air of various agricultural settings and occurrence of work-related symptoms in exposed workers, a meta-analysis of the results obtained in 1994-2007 on the territory of eastern Poland was performed. The studies on the airborne concentrations of total culturable microorganisms, mesophilic bacteria, Gram-negative bacteria, thermophilic actinomycetes, fungi, and bacterial endotoxins, as well as on the frequency of work-related respiratory and general symptoms in the exposed workers, were carried out at grain, thyme, valerian, flax, and hop handling on farms, in cow barns, piggeries, horse stables and in a modern hatchery. The airborne concentrations of the total microorganisms were in the range of 9.2-1236.5 × 10(3) CFU/m(3) , of the total mesophilic bacteria 3.5-1225.8 × 10(3) CFU/m(3) , of Gram-negative bacteria 0.0- 46.2 × 10(3) CFU/m(3) , of thermophilic actinomycetes 0.0-7.1 × 10(3) CFU/m(3) , of fungi 2.1-77.9 × 10(3) CFU/m(3) , and of bacterial endotoxin 0.00925-429.55 µg/m(3) . The frequency of work-related symptoms ranged between 21.7-63.8%. In a meta-analysis for assessment of the correlations between the log-transformed concentrations of airborne microbial agents and the occurrence of work-related symptoms, the multiple regression test was applied. Statistically significant correlations were found between the occurrence of work-related symptoms and the concentration of total airborne microorganisms (R=0.748555; P=0.020317), mesophilic bacteria (R=0.7573; P=0.029548), Gram-negative bacteria (R=0.835938; P=0.019129), and endotoxins (R=0.705356; P=0.03378). The correlations between the concentrations of thermophilic actinomycetes and fungi, on one side, and frequency of work-related symptoms on the other, did not attain the threshold of significance (P=0.087049 and P=0.062963, respectively). Results of the meta-analysis confirm harmful health effects of the total airborne microorganisms, total airborne mesophilic bacteria, airborne Gram-negative bacteria, and airborne bacterial endotoxin on the occupationally-exposed agricultural workers, and indicate a need for the establishment of internationally recognized occupational exposure limits for these microbial agents.