Rate of bentazone transformation in four layers of a humic sandy soil profile with fluctuating water table

The rate of transformation of a pesticide as a function of the depth in the soil is needed as an input into computations on the risk of residues leaching to groundwater. The herbicide bentazone was incubated at 15 °C in soil materials derived from four layers at depths of up to 2.5 m in a humic sandy soil profile with a fluctuating water table (0.8 to 1.4 m), while simulating the redox conditions existing in the field. Gamma‐irradiation experiments indicated that bentazone is mainly transformed by microbial activity in the soil. The rate constant for transformation was highest in the humic sandy top layer; it decreased with depth in the sandy vadose subsoil. However, material from the top of the phreatic aquifer had a higher rate constant than that from the layers just above. The presence of fossil organic material in the fluviatile water‐saturated sediment probably stimulated microbial activity and bentazone transformation. The changes in the transformation rate constant with depth showed the same trend as those in some soil factors, viz organic carbon content, water‐extractable phosphorus and microbial density as measured by fluorescence counts. However, the (low) concentration of dissolved organic carbon (DOC) in the top of the aquifer did not fit the trend. The rate constant for bentazone transformation in the layers was higher at lower initial contents of the herbicide. © 2001 Society of Chemical Industry     

Carabid beetle assemblages (Coleoptera,Carabidae) across urban-rural gradients: an international comparison

We studied communities of carabid beetles in residual forest patchesalong urban-suburban-rural gradients in three cities (Helsinki, Finland; Sofia,Bulgaria and Edmonton, Canada) to examine their responses to urbanisation. OnlyFinnish carabids showed a marked division of community structure along thegradient. In Bulgaria and Canada, carabids did not separate into distincturban,suburban and rural communities. Our results provide some support for thepredictions that species richness will decrease, that opportunistic specieswillgain dominance, and that small-sized species will become more numerous underdisturbance such as that provided by urbanisation. The rather weak and variedresponse of carabids to this disturbance suggests that local factors and theirinteraction are of primary importance for community composition. Occurrence ofreasonably similar carabid communities across the gradient at each of the threelevels of urbanisation suggests that habitat changes commonly associated withurbanisation have not affected the ecological integrity of carabid assemblagesin residual urban forest patches.This revised version was published online in May 2005 with corrections to the Cover Date.     

Bacterial colonization of intravenous catheters in young dogs suspected to have parvoviral enteritis

OBJECTIVE: To determine the prevalence of bacterial colonization of IV catheters among young dogs suspected to have parvoviral enteritis, to identify the organisms responsible for catheter colonization, and to determine the antimicrobial susceptibility of organisms that were obtained. DESIGN: Case series. ANIMALS: 100 dogs. PROCEDURE: Catheters were aseptically removed when fluid therapy was discontinued, the catheter was replaced, or the dog died. The distal tip of the catheter was cut off, split open, and vortexed with sterile saline (0.9% NaCl) solution. The saline solution was plated on culture plates, which were then incubated and examined for bacterial growth every 24 hours for 72 hours. All bacteria cultured were identified, and antimicrobial susceptibility was determined. RESULTS: Bacteria were isolated from 22 catheters. Most bacteria that were isolated were of gastrointestinal tract or environmental origin (Serratia odorifera, S. liquefaciens, S. marcescens, Acinobacter anitratus, Citrobacter freundii, Klebsiella pneumoniae, K. oxytoca, Escherichia coli, Enterobacter spp). Only 2 gram-positive organisms were isolated (Staphylococcus intermedius and Streptococcus spp). High percentages of organisms were resistant to penicillin, lincomycin, cloxacillin, erythromycin, and cephalexin. Percentages of organisms resistant to amikacin, enrofloxacin, chloramphenicol, potentiated sulfonamides, and amoxicillin-clavulanic acid were low. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that IV catheters may be colonized with bacteria in 22% of young dogs suspected to have parvovirus infection.     

Nematophagous fungi as a biological control agent for nematode parasites of small ruminants in Malaysia: a special emphasis on Duddingtonia flagrans

Approximately 2,800 fresh dung samples from animals, mainly ruminant livestock, were screened for the presence of nematophagous fungi in Malaysia. Arthrobotrys spp. was noted on numerous occasions, but only one isolate of Duddingtonia flagrans was made. For the purposes of producing sufficient quantities of this fungus for feeding trials in sheep, various, commonly available, cheap plant materials were tested as possible growth substrates. This showed that cereal grains (wheat, millet and rice) were the best media for fungal growth. Pen feeding trials were carried out using sheep, both naturally and experimentally infected with nematode parasites (predominantely Haemonchus contortus), to test the efficiency of D. flagrans when administered either in a grain supplement, or incorporated into a feed block. These showed that the fungus survived gut passage in sheep and that dose rates of approximately 1 x 10(6) D. flagrans spores / animal / day, reduced the percentage of infective larvae developing in faecal cultures by more than 90%. These results indicate that using D. flagrans as a biological control agent of nematode parasites, is a promising alternative to nematode parasite control of small ruminants in Malaysia, where anthelmintic resistance is now a major problem.     

Adrenal response to the low dose ACTH stimulation test and the cortisol-to-adrenocorticotrophic hormone ratio in canine babesiosis

This prospective, interventional, case-controlled study sought to determine the association between adrenocortical function and mortality in dogs with naturally occurring Babesia rossi babesiosis. Sixty-eight dogs with canine babesiosis were studied and fifteen normal dogs were used as controls. Blood samples were obtained from the jugular vein in each dog prior to treatment, at admission to hospital, for the measurement of basal plasma ACTH (adrenocorticotrophic hormone) and serum cortisol concentrations. Immediately thereafter, each dog was injected intravenously with 5 microg/kg of ACTH (tetracosactrin). A second blood sample was taken 1h later for serum ACTH-stimulated cortisol measurement and the resultant calculation of delta cortisol by subtracting basal from ACTH-stimulated cortisol. Diagnosis of babesiosis was confirmed by polymerase chain reaction (PCR) and reverse line blot (RLB). Three outcomes were defined: hospitalization with subsequent death (n=4); hospitalization followed by recovery (n=48); and treatment as an outpatient (n=16). Basal cortisol, but not ACTH-stimulated cortisol, was significantly higher in patients compared to control dogs. Basal- and ACTH-stimulated serum cortisol concentrations were significantly higher in the dogs that died, compared to hospitalized dogs that survived and compared to dogs treated as outpatients. There was no significant difference in delta cortisol concentrations or cortisol to ACTH ratios across outcome groups in dogs suffering from B. rossi babesiosis However, dogs with delta cortisol concentrations below 83 nmol/l had significantly higher cortisol to ACTH ratios compared to dogs with delta cortisol concentrations above 83 nmol/l. These findings of increased basal- and ACTH-stimulated cortisol and increased cortisol to ACTH ratios confirm the absence of adrenal insufficiency and concur with those in human malaria.     

A sero-epidemiological survey of Toxoplasma gondii infection in free-range and caged chickens in northeast China

Acquisition of Toxoplasma gondii infections is mainly through ingestion of parasite-contaminated food. T. gondii oocyst distribution in the living environment of human and livestock is directly linked to the prevalence of the parasite infection in humans and domestic animals. In this study, we investigated the sero-prevalence of T. gondii infection in free-range as well as caged chicken in northeast China. The purpose of this study was to investigate the potential prevalence of T. gondii oocysts in the environments. Sera of 308 free-range chickens and 210 caged chickens collected in three areas in northeast China were tested for anti-T. gondii antibodies with ELISA assays. The infection rates of free-range and caged chickens were 34.7% and 2.8% respectively, indicating that the parasite is widely distributed in the environment and poses threatens to the health of people living in those areas.     

Comparing the values of progesterone in the blood of bitches as measured with a chemiluminescence immunoassay and a radioimmunoassay

A ¹²⁵I radioimmunoassay (RIA) has long been used to determine the value of progesterone in serum or plasma of bitches but was discontinued in 2014. A chemiluminescence immunoassay (CLIA) gained prominence since 2003 to determine the value of progesterone in serum of bitches but the assay changed in 2012. This study assessed the agreement between progesterone values obtained with RIA in plasma (progRIA) and with the post‐2012 CLIA (progCLIA) in the serum of bitches. ProgCLIA was determined in 110 serum samples from 40 bitches in pro‐oestrus or early oestrus and compared to progRIA in plasma samples collected from the same bitches at the same time, where progRIA had a uniform distribution between 0.5 and 25 nmol/L. Two replicate analyses of each serum or plasma sample were simultaneously done in the same assay. For RIA and CLIA, the intra‐assay CVs were 5.85% and 6.70% and the interassay CVs 8.45% and 9.16%. For RIA and CLIA the progesterone values obtained with replicate analyses differed by as much as 11%–31% in 25% of samples. On average, the value of progCLIA was 85% of that of progRIA (95% CI 58%–112%, n = 110), with 88% of progCLIAs being lower than the progRIAs. This study shows that RIA and CLIA may yield replicate values that differ by as much as 11%–30% in about a quarter of samples analysed, necessitating replicate analyses if precise values are required. The study provides an equation by which to estimate progCLIA from progRIA.