Serologic and Urinary PCR Survey of Leptospirosis in Healthy Cats and in Cats with Kidney Disease

Background

Although there is serologic evidence of exposure of cats to Leptospira spp., clinical disease is rarely reported in cats.

Objective

To compare the seropositivity and urinary polymerase chain reaction (PCR) status for Leptospira spp. between healthy (H) cats and cats with kidney disease (KD), to investigate the serovars potentially involved, and to evaluate potential risk factors.

Animals

Two hundred and forty client‐owned cats.

Methods

Cats were prospectively recruited and classified based on physical examination, complete blood count, serum biochemistry profile, and urinalysis (125 H and 115 KD cats). Leptospira spp. serology (titers ≥1 : 100 considered positive) and urinary PCR were performed in all cats. Data assessing risk factors, obtained from a questionnaire, were evaluated using logistic regression models.

Results

Seropositivity for Leptospira spp. was statistically different between groups: 7.2% (9/125) and 14.9% (17/114) in the H and KD, respectively (P = .05). The proportion of PCR‐positive cats was not. The most common serovars detected serologically were Pomona (n = 16) and Bratislava (n = 8). Risk factors for seropositivity included outdoor and hunting lifestyles (P = .03 and P < .001, respectively), the presence of another cat in the household (P < .01), and the sampling period, with the greatest number of cases identified between June and August (P =.02).

Conclusions

Seropositivity was significantly greater in KD cats, suggesting that the role of Leptospira spp. in KD in cats should be further investigated. The detection of urinary shedding of leptospires in several cats identifies a potential role in the transmission of the organism.     

Cleavage of Arabidopsis PBS1 by a bacterial type III effector

Plant disease-resistance (R) proteins are thought to function as receptors for ligands produced directly or indirectly by pathogen avirulence (Avr) proteins. The biochemical functions of most Avr proteins are unknown, and the mechanisms by which they activate R proteins have not been determined. In Arabidopsis, resistance to Pseudomonas syringae strains expressing AvrPphB requires RPS5, a member of the class of R proteins that have a predicted nucleotide-binding site and leucine-rich repeats, and PBS1, a protein kinase. AvrPphB was found to proteolytically cleave PBS1, and this cleavage was required for RPS5-mediated resistance, which indicates that AvrPphB is detected indirectly via its enzymatic activity.     

Farmers' extension practice and technology adaptation: Agricultural revolution in 17–19th century Britain

The challenge of producing sufficient food to feed a growing world population cannot now be met by industrialized and green revolution agriculture as production is currently at or above a sustainable level. Future growth has to occur on resource-poor and marginal lands, where farmers have little or no access to external resources or research and extension support. A precedent for such growth occurred during the agricultural revolution in Britain. Over a period of two centuries crop and livestock production increased 3–4 fold as innovative technologies and techniques developed by farmers were extended to other farmers through tours, farmer groups, open days, and publications, and then adapted to local conditions by rigorous experimentation. These technologies maximized the use of on-farm resources at a time when there was no government ministry of agriculture, no research stations, and no extension institutions. But at the same time as this revolution in on-farm resource use, agriculture also expanded into uncultivated lands, increasing aggregate production but destroying common property resources and so threatening the livelihoods of the poor.     

Social connectedness in marginal rural China: The case of farmer innovation circles in Zhidan, north Shaanxi

The intrinsic dynamics andinnovative potential of the rural poor in Chinacan be illustrated by the phenomena of farmerinnovation circles (FIC) in north Shaanxi.These are informal networks used by farmers tocollaborate on technology learning andagricultural production. Though not limited tospecific geographic locations, these circlesare particularly important in the marginalareas of rural China where the complexity ofthe geographic environment, the diversity offarmer demands, and the inefficiency of formalagricultural extension networks impede thespread of new agricultural technologies. Socialconnectedness in the form of householdcommunication networks, technology learninggroups, and inter-village links aids people's collective capacity to work together. In thestudy of 50 villages in this remote region, itwas found that households with more connectionswere more likely to adopt a range of newtechnologies (ploughs, varieties, inputs,orchards, afforestation, grazing landrehabilitation), and so had higher income. Adetailed case study shows how collective actioncan lead to environmental improvements thatfurther increase incomes. It is concluded thatif there is to be sustainable development inthe marginal areas of China, then there willclearly need to be closer communication andinteraction between agricultural professionalsand rural communities.     

Simultaneous removal of Cu and PAHs from dredged sediments using flotation

Purpose

This study addresses the feasibility of a flotation technique, using a lab-scale flotation cell, to simultaneously remove both metals and polyaromatic hydrocarbons (PAHs) from fine sediment fractions (<250 μm) that are potentially contaminated with copper (Cu).

Materials and methods

A multiple flotation process with three consecutive flotation stages was performed on three sediments (13S, 14B, and 24A) with different particle size distributions, Cu and PAH concentrations, and organic matter contents.

Results and discussion

Flotations performed under selected conditions allowed for significant removal of both Cu (61–70 %) and PAHs (75–83 %) with acceptable froth recoveries of approximately 23–29 %. Removal rates for arsenic, lead, and zinc were 48–61, 40–48, and 32–36 %, respectively. Flotation selectivity of Cu was greatly influenced by the contents of fine particles and organic matter of the sediments. The maximum flotation selectivity was obtained for the 53–125-μm size fraction. The high flotation selectivity of Cu (2.5–3.2) and PAHs (3.0–3.6) demonstrated the feasibility of flotation to treat soils or sediments containing both organic and inorganic pollutants.

Conclusions

Overall, the flotation results showed a high selectivity for both Cu and PAHs and demonstrated the feasibility of flotation to treat media contaminated with organic and inorganic contaminants.     

Comparing effectiveness,cost- and time-efficiency of control options for Xanthomonas wilt of banana under Rwandan agro-ecological conditions

European Journal of Plant Pathology - Xanthomonas wilt of banana (XW) is a major disease affecting banana throughout East and Central Africa (ECA). Initial control was through complete diseased mat...