Feline cholecystitis and acute neutrophilic cholangitis: clinical findings, bacterial isolates and response to treatment in six cases

Clinicopathological findings from six cats with confirmed cholecystitis or acute neutrophilic cholangitis are presented. Historical findings included lethargy and anorexia or inappetence of up to five days duration. On physical examination all cats were pyrexic and four out of six were jaundiced and had cranial abdominal pain. Bile samples were obtained by cholecystocentesis at exploratory coeliotomy (two cases) or by percutaneous, ultrasound-guided cholecystocentesis (four cases). Gall bladder rupture and bile peritonitis occurred subsequent to ultrasound-guided cholecystocentesis in one case. The most common bacterial isolate was Escherichia coli (four cases); E coli was isolated alone in two cases, in combination with a Streptococcus species (one case) and in combination with a Clostridium species (one case). Streptococcus species alone was isolated from one case, as was Salmonella enterica serovar Typhimurium. The latter is the first reported case of Salmonella-associated cholecystitis in a cat. Concurrent pancreatic or intestinal disease was detected histologically in three cases. All cases were treated with antimicrobials based on in vitro susceptibility results. Treatment was successful in five cases. One cat with concurrent diffuse epitheliotropic intestinal lymphoma was euthanased. Percutaneous ultrasound-guided cholecystocentesis is an effective, minimally-invasive technique enabling identification of bacterial isolates in cats with inflammatory hepatobiliary disease.     

Herbicide risk assessment for non-target aquatic plants: sulfosulfuron--a case study

Herbicides entering the aquatic environment by spray drift, run-off and leaching to field drains may cause adverse effects on non-target aquatic vegetation. The potential for such effects has typically been evaluated from tests with floating, monocotyledonous Lemna sp. However, concern has been expressed as to whether this species could be used to indicate potential effects on other vegetation types, particularly rooted, submerged, emergent or dicotyledonous species. In 1997, the Centre for Aquatic Plant Management undertook development of new tests based on the additional species, Glyceria maxima (Hartm) Holmb, Lagarosiphon major (Ridl) Moss and Myriophyllum spicatum L. The resulting methodology was used to assess the effects of the sulfonylurea herbicide, sulfosulfuron on these species. Data presented here demonstrate that exposure to initial sulfosulfuron concentrations of 3.33 microg litre(-1) for up to 21 days was tolerated by these species and that adverse effects were observed only when plants were exposed to initial concentrations of 3.33 and 10 microg litre(-1) for 70 days. As the occurrence of such high initial concentrations for long periods is unlikely in the aquatic environment, sulfosulfuron is not expected to have adverse effects on the growth of these species. This study has also demonstrated that G maxima, L major and M spicatum grown in small outdoor tanks can be used successfully to assess the effects of crop-protection products on non-target aquatic flora.     

The effect of temperature on the phenotypic features and the maceration ability of <Emphasis Type="Italic">Dickeya solani</Emphasis> strains isolated in Finland,Israel and Poland

Pectinolytic bacteria from the genus Dickeya (former Erwinia chrysanthemi), belonging to Dickeya dianthicola and Dickeya solani species, are causative agents of blackleg and soft rot diseases in Europe. Recently, D. solani have been isolated most frequently from potato plants with the symptoms of blackleg and soft rot. D. solani strains were shown to cause more severe disease symptoms on potato plants than D. dianthicola especially at the higher temperature. They are also able to develop blackleg disease from lower inoculum levels. In the presented study we not only compared phenotypic features of fifteen D. solani strains isolated in countries having different climatic conditions, Poland, Finland and Israel, but also we examined three D. dianthicola strains. The comparison was performed to determine the influence of the strain origin and the temperature of incubation on the ability of the strains to macerate potato tissue and on their major virulence factors such as: pectinolytic, cellulolytic and proteolytic activities, siderophore production and motility. Polish D. solani strains showed higher activities of cell wall degrading enzymes than the Finnish and Israeli strains at all the tested temperatures: 18, 27, 37 °C. This observation is correlated with the higher ability of Polish D. solani strains to cause soft rot. In addition, D. solani strains exhibited higher activity of the above mentioned enzymes and caused more severe potato tuber maceration in laboratory tests than the tested D. dianthicola strains. The collected results indicate that although D. solani strains from different climatic conditions have identical Pulse Field Gel Electrophoresis (PFGE) profiles in addition to the same fingerprint profiles obtained by the repetitive sequence-based polymerase chain reaction (REP, ERIC and BOX repetitive sequences), they differ in the examined phenotypic features, especially in the activities of pectinolytic, cellulolytic and proteolytic enzymes and their capacity to macerate potato tuber tissue.     

The Importance of Rhizosphere Interactions in the Biological Control of Plant Parasitic Nematodes—a Case Study using Verticillium chlamydosporium

Verticillium chlamydosporium has provided considerable control of root knot nematodes in a range of laboratory experiments and is one of the most promising natural enemies with potential as a biological control agent so far tested. From a detailed study of the biology and ecology of the fungus, it has been possible to identify the key factors which affect its efficacy and a strategy for its exploitation has been developed. The fungus survives in soil throughout a growing season and its concentration in soil may be increased by repeated applications. The rapid multiplication of root-knot nematodes on susceptible crops means that control must be extremely effective to prevent crop damage. If suitable methods of production and application can be developed, V. chlamydosporium, in conjunction with other methods such as the rotation of poor hosts, may provide adequate control, but the reliability of such approaches needs extensive testing. Although genetic manipulation offers the possibility of enhancing the ability of the fungus to kill nematodes, such an approach will require much research and, in the short term, the development of the fungus will rely on the exploitation of carefully selected wild types.     

Herbicide safeners: a review

Herbicide safeners selectively protect crop plants from herbicide damage without reducing activity in target weed species. This paper provides an outline of the discovery and uses of these compounds, before reviewing literature devoted to defining the biochemical and physiological mechanisms involved in safener activity. Emphasis is placed on the effects of safeners on herbicide metabolism and their interactions with enzyme systems, such as cytochrome P₄₅₀ mono-oxygenases and glutathione-S-transferases. Attention is drawn to the potential wide-ranging applications of safeners and, in particular, their use as powerful research tools with which to identify and manipulate those mechanisms which contribute to herbicide selectivity and resistance. © 1999 Society of Chemical Industry     

Determination of elements removal in different harvesting scenarios of Scots pine (Pinus sylvestris L.) stands

Increasing demand for renewable energy and limiting CO₂ emissions have stimulated much interest in wood-based biofuels. Unfortunately, expanding the utilization of forest biomass may cause nutrient depletion in forested environments. This study investigates the element content from various parts of the tree. Comparisons were made between different harvesting scenarios and their impact on the amount of nutrients removed from the forest environment. The harvesting scenarios were: stem-only harvesting (SOH), branch and stem harvesting (BSH), and two variants of whole-tree harvesting (WTH). The elements taken into account were: carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), sulphur (S), copper (Cu), iron (Fe), nickel (Ni), manganese (Mn), zinc (Zn), cadmium (Cd), chromium (Cr) and lead (Pb). To make the results comparable, the same amount of removed biomass was taken into calculation. The differences between harvesting scenarios were significant. The amounts of removed elements formed similar pattern: the lowest level was found in SOH, average in BSH, and highest in both variants of WTH. This confirms that the application of WTH is connected with increased risk of nutrient depletion, even when the volume of harvest would be equal to other variants.     

Dynamics of ammonia excretion in juvenile common tench, Tinca tinca (L.), during intensive rearing under controlled conditions

This paper presents the first data on ammonia excretion by fed and starved juvenile common tench. The aim of the study was to determine the amount of ammonia excretion by juvenile common tench Tinca tinca (L.), fed with a commercial feed under intensive rearing conditions. Rearing was conducted for a period of 4 weeks at a water temperature of 27 °C. On the test day, the amounts of ammonia excreted by starved fish (over 12 h: control group) and fish fed with a morning feed dose (3 % of biomass: experimental group) were determined at 1, 3, 5, 7, 9 and 11 h after feeding. Ammonia excretion measurements were taken in 7-day intervals. Despite the increased growth rate in successive weeks of experiment, the amount of ammonia excreted by the fish was always at a similar level within the control (maximum 0.26 mg g^?1) and the experimental group (maximum 0.39 mg g^?1). This paper presents for the first time reliable amount of ammonia excreted by fed and starved juvenile common tench. The obtained results may also increase the effectiveness of intensive rearing procedures (taking into account stocking density and feeding regime) and allow to design the most effective biofiltration capacity of recirculating aquaculture systems for the commercial production of this species.