Experimental infections of mice and pigs with Streptococcus suis type 2.

Five inbred strains of mice were tested for their susceptibility to Streptococcus suis type 2 including the type strain, two isolates from meningitis in pigs and two isolates from tonsils of clinically healthy pigs. C57BL/6, ICR and ddY strain mice showed lower susceptibility to all strains of S. suis type 2 than BALB/c and SS strain mice. The type strain and the isolates from diseased pigs produced septicaemia and meningitis in BALB/c and SS mice inoculated with 10(8) colony forming unit of the bacteria and 60 to 100% of these infected mice died. On the other hand, mice inoculated with the isolates from healthy pigs showed mild clinical signs but none of them died. In BALB/c mice which died or developed nervous signs, the purulent meningo-encephalitis, myocarditis, ophthalmitis, labyrinthitis and otitis media were observed. S. suis type 2 antigen was demonstrated in these lesions by immunoperoxidase staining using rabbit S. suis type 2 antiserum. These results were similar to those in the experimentally infected pigs with these virulent and avirulent strains against mice. These results indicate that BALB/c and SS strains of mice are useful as an experimental model of S. suis type 2 infections in pigs, and that there are virulent and avirulent strains against mice and pigs among the strains of S. suis type 2.     

Bioavailability of suppository acetaminophen in healthy and hospitalized ill dogs

To determine the plasma pharmacokinetics of suppository acetaminophen (APAP) in healthy dogs and clinically ill dogs. This prospective study used six healthy client‐owned and 20 clinically ill hospitalized dogs. The healthy dogs were randomized by coin flip to receive APAP orally or as a suppository in crossover study design. Blood samples were collected up to 10 hr after APAP dosing. The hospitalized dogs were administered APAP as a suppository, and blood collected at 2 and 6 hr after dosing. Plasma samples were analyzed by ultra‐performance liquid chromatography with triple quadrupole mass spectrometry. In healthy dogs, oral APAP maximal concentration (C_MAX=2.69 μg/ml) was reached quickly (T_MAX=1.04 hr) and eliminated rapidly (T1/2 = 1.81 hr). Suppository APAP was rapidly, but variably absorbed (C_MAX=0.52 μg/ml T_MAX=0.67 hr) and eliminated (T_1/2 = 3.21 hr). The relative (to oral) fraction of the suppository dose absorbed was 30% (range <1%–67%). In hospitalized ill dogs, the suppository APAP mean plasma concentration at 2 hr and 6 hr was 1.317 μg/ml and 0.283 μg/ml. Nonlinear mixed‐effects modeling did not identify significant covariates affecting variability and was similar to noncompartmental results. Results supported that oral and suppository acetaminophen in healthy and clinical dogs did not reach or sustain concentrations associated with efficacy. Further studies performed on different doses are needed.     

Effect of urea supplementation on performance and safety in diets of Dorper crossbred sheep

This study was conducted to evaluate the efficacy and safety of dietary urea in sheep rations having a 50:50 concentrate:roughage ratio. Sixty‐four Dorper × thin‐tailed Han crossbred ram lambs with an average body weight of 30.8 (±0.02) kg were randomly divided into four groups of 16 sheep each, and each group was fed one of the following diets: a basal diet (CON), or CON supplemented with 0.5% (0.5UTM), 1.5% (1.5UTM) or 2.5% (2.5UTM) urea. Growth performance, carcass characteristics, non‐carcass offals, meat quality and peptic tissue lesions were assayed. The average daily weight gains for CON, 0.5UTM, 1.5UTM and 2.5UTM were 216, 218, 200 and 170 g, respectively, with the CON and 0.5UTM groups higher than 2.5UTM group (p < 0.05). Sheep from the 2.5UTM treatment had a significantly lower dry matter intake (1.29 kg/day) than those from the CON and 0.5UTM treatments (1.42 and 1.43 kg/day, p < 0.05), and the feed conversion ratio in the 2.5UTM group was the highest (p < 0.05). Carcass characteristics, including shrunk body weight, empty body weight, hot carcass weight, dress percentage, and the absolute or relative weight (% body weight) of heart, liver, spleen, lung and kidney, were not altered by the treatments (p > 0.05). The muscular pH of 2.5UTM was higher than that of CON (5.68 vs. 5.52, p < 0.05), and shear force in 0.5UTM was lower compared with CON and 2.5UTM (p < 0.05). The anatomical structure lesions in kidneys became more serious with the increasing dietary urea concentrations, with the 2.5UTM animals showing the most severe lesions compared with CON animals. Therefore, supplementary urea as a non‐protein nitrogen source for sheep should not exceed 1.5% of ration having a 50:50 concentrate:roughage ratio to ensure efficacy and safety.     

The Epidemiology and Characteristics of Q fever and Co‐infections with Scrub Typhus,Murine Typhus or Leptospirosis in Taiwan: A Nationwide Database Study

Q fever (QF) is a worldwide zoonosis associated with outbreaks. Only a few nationwide studies regarding the surveillance and epidemiology of human QF have been reported. Although QF is endemic in Taiwan, a nationwide database investigation of the epidemiology and characteristics of QF and its associations with scrub typhus (ST), murine typhus (MT) and leptospirosis (LS) has never been reported. We analysed nationwide databases of suspected QF, ST, MT and LS cases from October 2007 to December 2014 obtained from the Centers for Disease Control, Taiwan. A total of 468 (4.2%) QF cases were identified among 11 109 suspected QF cases. QF cases were mainly distributed in the southern and Kaohsiung–Pingtung regions but rarely in the eastern region. Compared to non‐QF cases, QF cases had significantly higher percentages of males (88.7 versus 66.2%) and high‐risk occupations (farming, animal husbandry or veterinary medicine) (16.2 versus 10.5%). But the percentages of specific animal contact, including cattle (0.6 versus 0.8%) and goats (0.9 versus 1.0%), were low in both. The majority of suspected QF cases (89.4%) were simultaneously suspected with ST, MT or LS, and the combinations of suspected diseases differed between regions. The number of suspected QF cases from the eastern region decreased since 2009, which was not observed in other regions. A total of 1420 (12.8%) cases had confirmed diseases, including QF (453, 4.1%), QF+ST (7, 0.06%), QF+MT (4, 0.04%), QF+LS (4, 0.04%), MT (186, 1.7%), ST (545, 4.9%), ST+LS (11, 0.1%) and LS (210, 1.9%). Compared to cases of unknown disease, QF cases had larger percentages of high‐risk occupations (16.2 versus 9.6%) but similar histories of animal contact (29.8 versus 25.1%). QF is an endemic disease in southern Taiwan. It is difficult to differentiate QF from ST, MT or LS only by high‐risk occupations and history of animal contact, and co‐infection of QF with these diseases should be considered.     

Expression of inducible nitric oxide synthase in macrophages inversely correlates with parasitism of lymphoid tissues in dogs with visceral leishmaniasis

Background

There are only a few studies reporting the role of nitric oxide metabolites for controlling macrophage intracellular parasitism, and these are controversial. Therefore, the present study aimed to evaluate the expression of inducible nitric oxide synthase (iNOS) in the lymph nodes and spleen of dogs affected by visceral leishmaniasis through immunohistochemistry and to determine its correlation with tissue parasite burden and serum interferon (IFN)-γ levels. Twenty-eight dogs were selected and assigned to one of two groups, symptomatic (n = 18) and asymptomatic (n = 10), according to clinical status and laboratory evaluation. A negative control group (n = 6) from a non-endemic region for visceral leishmaniasis was included as well.

Results

Parasite density (amastigotes/mm²) was similar between clinical groups in the lymph nodes (P = 0.2401) and spleen (P = 0.8869). The density of iNOS⁺ cells was higher in infected dogs compared to controls (P < 0.05), without a significant difference in lymph node (P = 0.3257) and spleen (P = 0.5940) densities between symptomatic and asymptomatic dogs. A positive correlation was found between the number of iNOS⁺ cells in lymph nodes and interferon-γ levels (r = 0.3776; P = 0.0303), and there was a negative correlation between parasites and iNOS⁺ cell densities both in lymph nodes (r = −0.5341; P = 0.0034) and spleen (r = −0.4669; P = 0.0329).

Conclusion

The negative correlation observed between tissue parasitism and the expression of iNOS may be a reflection of NO acting on the control of parasites.     

Vertical Distribution of Arthropod Interactions Within Turfgrass

Arthropod predators are abundant in turfgrass systems, and they play an important role in managing pests. Understanding the vertical distribution of predation is critical to developing cultural strategies that enhance and conserve predatory services. However, little is known on how the predation is vertically distributed within the turfgrass canopy. Thus, the objective of this study was to determine the vertical distribution of predation within the turfgrass canopy. Clay models were used to emulate the general appearance of Noctuidae caterpillars, to estimate the predatory activity. The choice and no-choice experiments were conducted by placing clay models at 2.54, 5.08, and 7.62 cm from the thatch surface and denoted as lower, intermediate, and upper levels, respectively, within turfgrass canopy. The predator-mediated impressions, paired mark, scratch, deep cut mark, deep distortion, prick, dent, stacked surface impression, scooped mark, granulation, and U-shaped mark, were identified on clay models. The incidence and severity of impressions were significantly greater on clay models placed at the lower canopy level than on those placed at the intermediate and upper canopy levels in the choice and no-choice experiments (P < 0.05). Thus, predators are more likely to find their prey at the soil level. This information can be used to refine management strategies, such as mowing height and insecticide use for effectively managing soil-borne and foliar-feeding arthropod pests and beneficial arthropods.     

Purification and characterisation of chicken liver monomeric glutathione peroxidase

1. A novel glutathione peroxidase, which is distinct from tetrameric glutathione peroxidase, was purified to homogeneity from a broiler chick liver cytosolic fraction using 5 different column chromatographic methods.

2. The enzyme in cytosol was separated from ‘classic’ tetrameric glutathione peroxidase and glutathione S‐transferases by DEAE‐Sephacel and Sephadex G‐100 chromatographies and further purified by Mono Q, hydroxylapatite and sulphobro‐mophthalein‐S‐glutathione‐agarose chromatographies.

3. The molecular weight of the purified enzyme determined by sodium dodecyl sulphate‐polyacrylamide gel electrophoresis was 19,500 and that found by gel filtration chromatography was comparable. This indicates that the enzyme protein is a single polypeptide. The isoelectric point of the enzyme was determined as 7.0 by polyacrylamide gel isoelectric focusing.

4. The purified enzyme catalysed the reduction of hydrogen peroxide, cumene hydroperoxide, tert‐butyl hydroperoxide and linoleic acid hydroperoxide. Furthermore, it reduced phosphatidylcholine hydroperoxide in the absence of phospholi‐pase A2. The optimum pH for the enzyme reaction was 7.0. The antiserum against the purified enzyme reacted with the 19.5 kDa polypeptide in the liver cytosol of duck and quail.     

Phoma leaf spot of wasabi (Wasabia japonica) caused by Leptosphaeria biglobosa

A leaf spot disease on wasabi plants grown in commercial greenhouses in the Fraser Valley of British Columbia was characterized. Mycelial growth and pycnidial formation were observed within lesions when leaves were incubated under conditions of high humidity. Isolation from diseased tissues consistently yielded colonies of a Phoma species. Sequence analysis of the rDNA internal transcribed spacer (ITS1‐5.8S‐ITS2) region of eight isolates showed 100% nucleotide sequence identity with Phoma wasabiae and Leptosphaeria biglobosa subspecies ‘occiaustralensis’ and 99.2% identity with L. biglobosa ‘canadensis’. Pathogenicity studies on wasabi leaves showed that wounding greatly facilitated infection and enhanced lesion development for most isolates but was not required for all isolates. Chlorotic areas appeared around the inoculation sites within 4 days, followed by necrosis. Isolates displayed a range of virulence, from weakly to highly virulent, on wasabi leaves. Similar results were observed on leaves of canola cultivar Westar, i.e. wounding significantly increased lesion size and isolates displayed a range of virulence. An isolate of Leptosphaeria maculans ‘brassicae’ from canola was highly virulent on wasabi and canola leaves, causing lesions similar to those of L. biglobosa ‘occiaustralensis’ while an isolate of L. biglobosa ‘canadensis’ from canola was weakly virulent on both hosts and required wounds to infect. These results demonstrate that isolates of L. biglobosa ‘occiaustralensis’ from wasabi are as virulent as L. biglobosa ‘canadensis’ on wasabi and canola leaves but in some cases were comparable in virulence to L. maculans ‘brassicae’.