Prevalence and characteristics of intimin- and Shiga toxin-producing Escherichia coli from gulls,pigeons and broilers in Finland

The role of birds as sources of Shiga toxin-and intimin-producing Escherichia coli was studied. Fecal samples from live gulls (n=86), pigeons (n=33) and broiler chickens (n=199) from 23 flocks were analyzed for stx and eae by PCR. No stx positive samples were detected. In contrast, eae E. coli were highly prevalent among gulls (40%), and was also found in pigeons (7%) and chickens (57% of the flocks contaminated). The eae positive isolates were analyzed genetically and O-serogrouped. One isolate from a pigeon was found to have stx (2f). The isolates of gulls differed from those of pigeons and chickens, and all eae E. coli isolates from birds differed from human pathogenic strains by the lack of EHEC-hlyA and bfp/EAF as well as distribution of O-serogroups. Thus, birds cannot be regarded as important carriers of zoonotic stx or eae E. coli in Finland.     

Fatty acids and fat-soluble vitamins in salted herring (Clupea harengus) products

The fatty acid composition and contents of fat and fat-soluble vitamins of three salted products prepared from Icelandic herring were analyzed. The effects of storage on the products over their shelf life, 6 or 12 months, were investigated. The average oil content of salted, gutted herring and salted fillets in vacuum remained constant, 17 and 12% of wet weight, respectively. In the pickled product the oil content decreased during the 12 months of storage from 13 to 12%. The composition of the products was typical for herring, the most abundant fatty acids being oleic (18:1n-9), palmitic (16:0), cetoleic (22:1n-11), and gadoleic (20:1n-9) acids. Monounsaturated acids constituted clearly the main group with a proportion of >50% of all fatty acids. Eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3) comprised together >12% of all fatty acids. During storage, some hydrolysis of triacylglycerol (TAG) occurred, causing a slight reduction in practically all esterified fatty acids. In none of the three products was the loss of polyunsaturated fatty acids from TAG greater than the loss of saturated ones, indicating that the loss of EPA and DHA was not due to oxidation. After packing, the average content of vitamins A, D, and E in the products varied between 27 and 87 microg/100 g (wet weight), between 17-28 microg/100 g (wet weight), and between 77-120 microg/100 g (wet weight), respectively. During storage, the level of vitamin A decreased significantly, whereas no loss of vitamin D was observed. The content of vitamin E was low in all products and showed wide variation. When compared to the recommended daily intake, it could be concluded that the products investigated were good and stable sources of long-chain n-3 fatty acids (EPA, DHA) and vitamin D.     

Peat Biofilters in Long-Term Experiments for Removing Odorous Sulphur Compounds

Peat was employed as a biological filter material for the removal of hydrogen sulphide (H_2> S) dimethyl sulphide (Me₂S) and methyl mercaptan (MeSH) from odorous ventilation air. Removal of H₂S was possible without the need to inoculate the filter material with oxidizing microbes whereas Me₂S required inoculation for degradation. The removal of Me₂S was decreased as a result of MeSH addition. Liming of the filter material, i.e., addition of calcium hydroxide, increased removal efficiency and activated the oxidation of H₂S without any adaptation period. As a consequence of the poor Me₂S removal efficiency of natural peat, a limed and inoculated biofilter was needed to purify mixtures of gases containing sulphur. The highest H₂S load tested with limed but otherwise natural peat was 136 g-S m^-3 day^-1, yielding a 99 % reduction. The maximum Me₂S elimination capacity with limed and inoculated peat was 175 g-S m^-3day^-1, but removal became unstable when the load exceeded 150 g-S m^-3day^-1. The maximum MeSH load tested was 107 g-S m^-3day^-1, yielding 98 % removal.     

Temporal changes in concentrations of serum amyloid-A and haptoglobin and their associations with weight gain in neonatal reindeer calves

Age-related changes in serum concentrations of two acute phase proteins (APPs), haptoglobin (Hp) and serum amyloid-A (SAA) were investigated in newborn reindeer calves. Repeated blood samples were obtained from 51 reindeer calves at ages 0-32 days (2-4 samples from each calf). An increase of SAA concentrations was observed during the first 2 weeks of life. However, by the end of the observation period, SAA concentrations had decreased to levels below those of the first week. Serum Hp concentrations increased throughout the observation period. SAA concentrations in the second week had a negative association with weight gain during the entire study period (4 months). These time-related changes in APP concentrations suggest that these proteins have a role in the defence and adaptation mechanisms of newborn reindeer calves. Possible reasons for these changes include the presence of APP mediators in the colostrum, exposure to environmental pathogens after birth and age-related changes in hepatic synthesis of APP.     

Effects of timing of soil frost thawing on Scots pine

Effects of the timing of soil thawing in the spring on Scots pine (Pinus sylvestris L.) were studied under controlled laboratory conditions. Sixteen 6-year-old saplings were lifted from the field, replanted in containers and placed in four treatments in controlled environment (CE) chambers with four replicate saplings per chamber. The saplings were held in the CE chambers during one simulated winter and one simulated growing season. The soil was frozen to -2 degrees C during a second simulated winter in the CE chambers, and the soil thawing treatments began at the end of the second simulated winter. Soil thawing began at various times before (no delay in thawing) and after (delay in thawing) chamber air conditions were changed from simulated winter to simulated summer. Delayed soil thawing subjected saplings to stress, with the severity of stress depending on the length of the delay in thawing. If there was no delay or only a short delay in soil thawing, stress was minor and reversible. A 2-week delay in soil thawing led to death of the saplings. Stress was apparent as decreases in the variable to maximal chlorophyll fluorescence ratio (Fv/Fm), chlorophyll a/b ratio and needle water potential. In needles of stressed saplings, apoplastic electrical resistance first decreased and then increased and there were anomalies in the electrical impedance spectra of the stems. Stress from the soil thawing treatments affected both root and shoot growth.     

Boron retranslocation in Scots pine and Norway spruce

We previously traced 10B-enriched boric acid from shoots to roots to demonstrate the translocation of boron (B) in Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings. To gain a more detailed understanding of B translocation, we sought: (1) to demonstrate B retranslocation directly, by showing that foliar-applied 10B is located in the new growth after dormancy; and (2) to assess whether shoot-applied B affects growth in the long term. We applied 10B-enriched boric acid to needles of Scots pine and Norway spruce seedlings. After a dormancy period and 9 weeks of growth, small but significant increases in the 10B isotope were found in the new stem and needles of both species. In Scots pine, the total B concentration of the new stem was also increased. Both species contained polyols, particularly pinitol and inositol. Boron-polyol complexes may provide a mechanism for mobilizing B in these species. To determine the long-term effects of applied B, seedlings were grown for two growing seasons after the application of 10B to shoots. In Norway spruce, the proportion of 10B in the root systems and current needles of the harvest year was slightly higher than in the controls, and in Scots pine root systems, marginally so. The B treatment had no effect on growth of Norway spruce seedlings. In Scots pine seedlings, the B treatment caused a 33% increase in total dry mass and significantly increased the number of side branches.     

The effect of isolation method on the chemical structure of residual lignin

Two methods are used for the isolation of residual lignin: acidolytic and enzymatic hydrolysis. Recently a two-step procedure that is a combination of enzymatic and acidic hydrolyses was proposed. In this paper, the structures of residual lignins isolated by these three methods are compared. Enzymatic hydrolysis gave lignin with the highest yield (83%); however, it contained high amounts of carbohydrates and protein. The molar mass of enzymatic lignin was the highest, indicating that no cleavage of lignin occurred. Acidolysis gave a significantly lower lignin yield (40%), but this lignin was practically free from impurities. The -aryl ether and lignin-carbohydrate linkages cleaved during the isolation, which was manifested in the decreased molar mass of the lignin as well as in increased phenolic hydroxyl group content. The new two-step isolation procedure gave properties between the preparations of enzymatic and acidolytic hydrolyses. The lignin yield was high (78%), but it contained some impurities, although less than the enzymatic lignin. The lignin-carbohydrate linkages cleaved to some extent, but the -aryl ether linkages remained intact.Y. Sun also affiliated with the Pulp and Paper Research Institute of Canada (PAPRICAN), Pulp and Paper Research Centre, McGill University.     

Concurrent bartonellosis and babesiosis in a dog with persistent thrombocytopenia

A 12-year-old castrated male West Highland White Terrier was referred because of recurrent episodes of collapsing. The dog was mildly anemic and severely thrombocytopenic and had high serum alanine aminotransferase activity. Infection with Bartonella vinsonii (berkhoffii) was initially diagnosed on the basis of serologic testing. Despite treatment with a series of antimicrobials and prolonged use of immunosuppressive drugs, thrombocytopenia persisted. After 5 months of treatment, Babesia canis organisms were seen during examination of a direct blood smear. The dog was treated with imidocarb dipropionate for babesiosis, after which thrombocytopenia resolved, and administration of immunosuppressive drugs was discontinued. Retrospective review of blood smears failed to identify organisms; however, polymerase chain reaction (PCR) analysis of multiple stored blood samples obtained during the 5-month period of persistent thrombocytopenia identified DNA of B. canis vogeli. Babesiosis may cause persistent, unexplained thrombocytopenia in dogs that are not anemic. A PCR assay can facilitate a diagnosis of babesiosis when organisms are not evident or when serologic testing fails to detect Babesia-specific antibodies.