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Physiological parameters in fish provide grounds for conclusions as to the physiological status of the organism. The status is directly related to inner and outer factors, biotic and abiotic influences which act on the organism. Present studies aimed at defining the set of immunological and haematological indices in breams, which form fish populations in Dabie Lake and Szczecin Bay, whose ecosystems differ in water cleanness. Immunological studies in breams involved determining selective defensive functions of neutrophilic granulocytes, expressed by the index of phagocytosis of a standard bacterial strain (Ipg), the percentage of phagocytes which ingested the bacteria (%gp), NBT index, the amount of formazan and the index of myeloperoxidase activity (WA MPO). Haematological studies included determination of absolute leukocyte number and the differential leukocyte pattern. Bacteriological and physicochemical studies were also performed on water samples of reservoir sites from which the fish originated. Results of examination of water samples from Dabie Lake and Szczecin Bay demonstrated a significant level of water pollution in the ecosystems. A definitely higher level of water pollution, particularly in respect to bacterial contamination, was observed in Dabie Lake. Comparison of immunological and haematological results demonstrated significant differences between the two studied bream populations, i.e. those originating from Dabie Lake and the other, originating from Szczecin Bay. Such differences were disclosed both in immunological and in haematological indices. INSET: European Community Post - and Predoctoral Fellowships.... [ABSTRACT FROM AUTHOR]

Our studies were aimed at bacteriological analysis of water in the small municipal lake of Rusałka, in Szczecin. The studies were conducted over four years, in monthly intervals, assuming that the results will enable detailed analysis of bacteriological characteristics of the water in the tested reservoir and will yield sanitary and ecological characteristics of the reservoir. The quantitative estimation included index bacteria for the extent of pollution, index bacteria of sanitary condition, bacteria of selected physiological groups (ammonification bacteria, denitrification bacteria) as well as the presence of thermophile bacteria, sporulating bacteria, bacteria capable of sulphate reduction (Desulfotomaculum nigrificans). Also, the ratio was calculated for foecal-type coli group bacteria to foecal streptococci, treated as an index of origin of foecal--type pollution. The obtained results were subjected to statistical analysis. In the studied lake high values of all the examined parameters were disclosed. The high numerical force of index bacteria for the extent of pollution (TVC 20°C, TVC 37°C) and of index bacteria for sanitary condition (coli group bacteria, foecal type coli group bacteria, foecal streptococci) pointed to contamination of the lake by household sewage. The observed high numbers of bacteria participating in turnover of nitrogen compounds (ammonification and denitrification bacteria) indicated a continuous inflow of nitrogen-rich compounds and development of water self-purification. The values of most studied parameters obtained by us were in general higher than the values noted in the same lake in previous years and higher than the values noted in other municipal lakes in Poland. [ABSTRACT FROM AUTHOR]

Commensal Escherichia coli population is a dynamic structure which may be important in the pathogenesis of extraintestinal infections. The aim of this study was the comparison of genetic diversity of commensal E. coli isolates from two age group-adults and young children. E. coli strains were isolated on MacConkey agar and identified by biochemical tests. Determination of four major phylogenetic groups, identification of virulence genes and antimicrobial resistance determinants were performed by using multiplex or simplex PCR. Phenotypic analysis of resistance was based on disc-diffusion method. The prevalence of virulence genes was significantly higher among isolates from adults than from young children. Phylogroup B2 predominated among E. coli from adults, whereas phylogroup A was the most common in isolates from young children. The analyses of antimicrobial resistance revealed that resistance to at least one antimicrobial agent and multidrug-resistance were detected significantly more frequent in the isolates from adults than from young children. This study documented that the commensal E. coli isolates from adults showed greater genetic diversity than from young children and constitutes a substantial reservoir of the virulence genes typical for extraintestinal pathogenic E. coli ., Competing Interests: The authors declare no conflict of interest.

Cattle is a reservoir of potentially pathogenic E. coli, bacteria that can represent a significant threat to public health, hence it is crucial to monitor the prevalence of the genetic determinants of virulence and antimicrobial resistance among the E. coli population. The aim of this study was the analysis of the phylogenetic structure, distribution of virulence factors (VFs) and prevalence of antimicrobial resistance among E. coli isolated from two groups of healthy cattle: 50 cows housed in the conventional barn (147 isolates) and 42 cows living on the ecological pasture (118 isolates). The phylogenetic analysis, identification of VFs and antimicrobial resistance genes were based on either multiplex or simplex PCR. The antimicrobial susceptibilities of E. coli were examined using the broth microdilution method. Two statistical approaches were used to analyse the results obtained for two groups of cattle. The relations between the dependent (VFs profiles, antibiotics) and the independent variables were described using the two models. The mixed logit model was used to characterise the prevalence of the analysed factors in the sets of isolates. The univariate logistic regression model was used to characterise the prevalence of these factors in particular animals. Given each model, the odds ratio (OR) and the 95% confidence interval for the population were estimated. The phylogroup B1 was predominant among isolates from beef cattle, while the phylogroups A, B1 and D occurred with equal frequency among isolates from dairy cattle. The frequency of VFs-positive isolates was significantly higher among isolates from beef cattle. E. coli from dairy cattle revealed significantly higher resistance to antibiotics. Some of the tested resistance genes were present among isolates from dairy cattle. Our study showed that the habitat and diet may affect the genetic diversity of commensal E. coli in the cattle. The results suggest that the ecological pasture habitat is related to the increased spreading rate of the VFs, while the barn habitat is characterised by the higher levels of antimicrobial resistance among E. coli.

Genetic polymorphism of 83 isolates of E. coli, derived from 4 species of artiodactyla animals living in a relatively close contact on the grounds of a theme park ZOO Safarii Swierkocin (Poland) was determined using the rep-PCR fingerprinting method, which utilizes oligonucleotide primers matching interspersed repetitive DNA sequences in PCR reaction to yield DNA fingerprints of individual bacterial isolates based on repetitive extragenic palindrome (REP) primers. The fingerprint patterns demonstrated the essential polymorphism of distribution of REP sequences in genomes of the examined isolates. The arithmetic averages clustering algorithm (UPGMA) statistical analysis of fingerprints with the use of the Jaccard similarity coefficient differentiated E. coli isolates into three similarity groups containing various numbers of isolates. The groups comprised isolates derived from two, three and four species of the source animals. The isolates derived from each source segregated in the dendrogram in a different way, both within the similarity groups and among them, indicating an individual repertoire of E. coli in the examined species of animals. The similarity relations among E. coli derived from the same source, illustrated in a dendrogram with a number of subclusters of a low mutual similarity (< or = 20%), indicated an essential interstrain differentiation in terms of the distribution of REP sequences. Our results confirmed the hypothesis of the oligoclonal characters of populations obtained from particular sources. The rep-PCR fingerprinting method with REP primers is simple and highly differentiating and can be recommended for use in explorations of large groups of animals and monitoring the variability of strains.

The authors present results of serological examination in 275 pheasants (Phaisanus colchicus) and 273 pigeons (Columba livia f. domestica) for the presence of Chlamydophila (Ch) psittaci IgG antibodies. Using micromethod of complement fixation (CF) test with genus-specific antigen Ch. psittaci (Bioveta, Ivanovice na Hané, Czech Republic), the seropositivity in pheasants oscillated between 31.5-40.4 %. No clinical signs of chlamydiosis were detected in pheasants under study. The seropositivity in pigeons ranged between 33.1-85.1%. Total 77.1% positivity with maximal 1:1024 antibody titre was found in 83 pigeons caught in April 2000, while, in June 2000 positivity was 41.0% with maximum titre 1: 512. Similarly, in the year 2001 the seropositivity in the group of 74 pigeons trapped in April reached up to 85.1% with the highest titre 1:1024 and in the pigeons trapped in June positivity decreased to 33.3% with the titer 1:256. These results prove an acute form of chlamydiosis and suggest that pigeons in spring time are an especially significant source of chlamydiosis for the human and animal population.

The paper presents usefulness of application of the PCR-based fingerprinting method, which uses enterobacterial repetitive intergenic consensus primers ERIC (rep-PCR (ERIC)) in analysing and characterising Escherichia coli population in the water environment. 46 E. coli isolates of homogenous biochemical properties were analysed. The received results prove considerable genomic diversity among the analysed isolates. The used technique has turned to be a reproducible and rapid method with a considerable differentiation power. The introductory research has revealed that the technique may be successfully used in qualitative research, for intra-species differentiation of microorganisms occurring in water environment.