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The influence of climate change on wildlife disease dynamics is a burgeoning conservation and human health issue, but few long‐term studies empirically link climate to pathogen prevalence. Polar bears (Ursus maritimus) are vulnerable to the negative impacts of sea ice loss as a result of accelerated Arctic warming. While studies have associated changes in polar bear body condition, reproductive output, survival, and abundance to reductions in sea ice, no long‐term studies have documented the impact of climate change on pathogen exposure. We examined 425 serum samples from 381 adult polar bears, collected in western Hudson Bay (WH), Canada, for antibodies to selected pathogens across three time periods: 1986–1989 (n = 157), 1995–1998 (n = 159) and 2015–2017 (n = 109). We ran serological assays for antibodies to seven pathogens: Toxoplasma gondii, Neospora caninum, Trichinella spp., Francisella tularensis, Bordetella bronchiseptica, canine morbillivirus (CDV) and canine parvovirus (CPV). Seroprevalence of zoonotic parasites (T. gondii, Trichinella spp.) and bacterial pathogens (F. tularensis, B. bronchiseptica) increased significantly between 1986–1989 and 1995–1998, ranging from +6.2% to +20.8%, with T. gondii continuing to increase into 2015–2017 (+25.8% overall). Seroprevalence of viral pathogens (CDV, CPV) and N. caninum did not change with time. Toxoplasma gondii seroprevalence was higher following wetter summers, while seroprevalences of Trichinella spp. and B. bronchiseptica were positively correlated with hotter summers. Seroprevalence of antibodies to F. tularensis increased following years polar bears spent more days on land, and polar bears previously captured in human settlements were more likely to be seropositive for Trichinella spp. As the Arctic has warmed due to climate change, zoonotic pathogen exposure in WH polar bears has increased, driven by numerous altered ecosystem pathways., Western Hudson Bay (WH) polar bear serum samples were analysed for antibodies to seven pathogens across three time periods: 1986–1989, 1995–1998 and 2014–2017. Antibodies to zoonotic pathogens increased between the 1980s and all other time periods, and were driven by environmental variables undergoing climate change. The increase in antibodies was greatest between 1986–1989 and 1995–1998, a period during which WH polar bears experienced declines in abundance, body condition and reproductive output.

Indirect enzyme-linked immunosorbent assay (ELISA) utilizing excretory-secretory (E-S) antigens of Trichinella spiralis is currently the method of choice for testing pigs and wild boars for exposure to Trichinella spp. The E-S proteins are released by first-stage larvae (L1) of this parasitic nematode maintained in vitro. However, the production of these antigens is cumbersome and time-consuming. The process requires animals to be experimentally infected with the parasite as the source of L1. Antigen production using recombinant technology would be more time- and cost-effective. In this study, we produced a Serpin of T. spiralis as a recombinant protein secreted by the yeast Pichia pastoris. The diagnostic performance of indirect ELISA with purified Serpin antigen was compared to that of E-S ELISA. Both Serpin ELISA and E-S ELISA demonstrated 98 % diagnostic specificity in testing 1056 pigs from the Canadian Trichinella-free commercial herd. Twenty of 21 pigs with non-negative test results in E-S ELISA tested negative by the confirmatory Western blot (WB) assay. Therefore, the diagnostic specificity of combined E-S ELISA and WB was 99.9 %. Forty-five sera collected at or after six weeks from 34 pigs experimentally infected with various numbers of T. spiralis L1 produced positive results in both E-S and Serpin ELISA, resulting in 100 % diagnostic sensitivity. However, testing of sera serially collected from four pigs experimentally infected with various low doses of T. spiralis L1 demonstrated a delayed Serpin-specific antibody response compared to seroconversion detected by E-S ELISA in three animals. Moreover, Serpin ELISA demonstrated significantly lower sensitivity for detecting antibodies induced by experimental infections of pigs with T. britovi, T. nativa, Trichinella T6 and T. pseudospiralis, suggesting that it will not provide consistent detection of exposure to sylvatic Trichinella spp. The validation data support the application of Serpin ELISA in seroepidemiological surveys for detecting exposure to T. spiralis in swine.

Species of Trichinella are a globally distributed assemblage of nematodes, often with distinct host ranges, which include people, domestic, and wild animals. Trichinella spp. are important in northern Canada, where dietary habits of people and methods of meat preparation (drying, smoking, fermenting as well as raw) increase the risk posed by these foodborne zoonotic parasites. Outbreaks in the arctic and subarctic regions of Canada and the United States are generally attributed to T. nativa (T2) or the T6 genotype, when genetic characterization is performed. We report the discovery of Trichinella pseudospiralis (T4), a non-encapsulated species, in a wolverine (Gulo gulo) from the Northwest Territories of Canada. This parasite has been previously reported elsewhere from both mammals and carnivorous birds, but our findings represent new host and geographic records for T. pseudospiralis. Multiplex PCR and sequencing of fragments of Cytochrome Oxidase Subunit I (COI) and D3 rDNA confirmed the identification. Phylogenetically, Canadian isolates linked with each other and others derived from Palearctic or Neotropical regions, but not elsewhere in the Nearctic (continental USA). We suggest that migratory birds might have played a role in the dispersal of this pathogen 1000's of km to northwestern Canada. Wolverines are not typically consumed by humans, and thus should not pose a direct food safety risk for trichinellosis. However, the current finding suggests that they may serve as an indicator of a broader distribution for T. pseudospiralis. Along with infection risk already recognized for T. nativa and Trichinella T6, our observations emphasize the need for further studies using molecular diagnostics and alternative methods to clarify if this is a solitary case, or if T. pseudospiralis and other freeze susceptible species of Trichinella (such as T. spiralis) circulate more broadly in wildlife in Canada, and elsewhere., Graphical abstract (Picture of wolverine: Wolverine picture: credit to Gustaf Samelius, Snow Leopard Trust, Seattle, Washington 98103, USA).Image 1, Highlights • First documentation of Trichinella pseudospiralis on the mainland of Canada. • Second molecular characterization of T. pseudospiralis from Canada. • Northernmost observation of T. pseudospiralis from North America. • Most closely related to isolates from Palearctic and Neotropics, not Nearctic.

Trichinella spp. nematodes are commonly found in bear species (Ursidae) and can pose severe health risks to humans when infective first-stage larvae are ingested in meat. Samples of tongue or masseter muscle from 22 male and 11 female American black bears (Ursus americanus; mean age 6.5 yr, range 1-16 yr) and 22 male, eight female, and one unknown sex grizzly bears (Ursus arctos; mean age 8.8 yr, range 2-28 yr), from Yukon, Canada, were tested to determine prevalence and intensity of Trichinella spp. infection. For black bears, prevalence was 20% and mean intensity was 401 larvae per gram of tissue (LPG), whereas for grizzly bears, prevalence was 71%, and mean infection intensity was 35 LPG. Isolates from all positive samples were identified as genotype Trichinella-T6 by multiplex PCR. For black bears, prevalence is the highest reported in Canada and infection intensity the highest recorded in North America. One black bear had a larval burden of 1,173 LPG, the second highest recorded in any host species. The prevalence in grizzly bears was the highest reported in Canada for this host. In total, 90% (27 of 30) of infected bears had infection burdens above the human food safety threshold of ≥1 LPG, reinforcing the importance of communicating the health risks to people consuming bear meat.

Herein we describe the origin of the International Commission on Trichinellosis more than 60 years after its foundation. We attempt to clarify previous debate over the founding presidents and particularly the role of Polish parasitologist, Zbigniew Kozar. Seminal and core proceedings of the Commission published in Wiadomości Parazytologiczne and other records were used to advance this goal. An early regional commission initially held in Budapest, Hungary at the Hungarian Meeting of Parasitologists was devoted to trichinellosis and was presided over by Kozar from 1958 to 1960. However, the official formation of the Commission did not occur until 1960 during the 1st International Conference on Trichinellosis held in Warsaw, Poland, where Witold Stefanski was elected president. During the 2nd International Conference on Trichinellosis, which was held in 1969 in Wroclaw, Poland, Samuel E. Gould was elected president until his untimely death in 1970. Zbigniew Kozar was secretary general from 1960 to 1972. Beginning with the 3rd International Conference held in Miami, Florida, USA in 1972, the activities of the Commission and the Conference became better documented.

Trichinella spiralis typically infects domestic swine, wild boar and occasionally horses, has a cosmopolitan distribution, and consequently is most frequently associated with food-borne outbreaks of trichinellosis in humans. Trichinella murrelli is typically found in wild carnivores in temperate areas of North America, where it has been responsible for outbreaks of human trichinellosis due to consumption of infected wild game. There has previously been only indirect evidence of natural infection with T. murrelli in a horse originating from Connecticut and implicated in an outbreak of trichinellosis in France in 1985. We describe a T. murrelli infection detected during routine testing of a horse from the USA imported to Canada for slaughter and export to the European Union (EU). Approximately 5 or more larvae per gram were recovered from digested tongue and diaphragm samples and identified as T. murrelli by PCR. This case provides the first direct evidence of naturally acquired T. murrelli infection in a horse, and further supports the potential food safety risk posed by this parasite species. It is the first instance in Canada of the detection of a Trichinella-infected horse via routine post-mortem testing. Trichinella spiralis-infected horses have been similarly detected by regulatory testing in France, and further details of two such previously reported cases are also provided here. The cases described herein underscore the importance of continued vigilance in quality assured food safety testing of horse meat to mitigate the risk of human trichinellosis.

Trichinella is a zoonotic nematode parasite transmitted by the ingestion of raw or under-cooked meat. Control of the parasite is essential to facilitate public health and trade in products from susceptible food animals, including pork and horse meat. The standard method for detecting Trichinella muscle larvae uses pepsin enzyme and hydrochloric acid (HCl) in an artificial digestion procedure. A new artificial digestion assay using serine protease was recently developed and commercialized (PrioCHECK™ Trichinella AAD) for the detection of Trichinella larvae in the muscle of infected animals. The assay uses no hazardous substances such as HCl or pepsin. Activation of the enzyme requires an elevated digestion temperature of 60 °C which kills the parasite and reduces the risk of contaminating the environment with Trichinella. Compared to the pepsin/HCl method, digestion time for the PrioCHECK Trichinella AAD assay is reduced by a third. A recent study demonstrated these features of the new assay and its suitability for digesting various muscles from domestic and wild animals. To further validate the assay's performance relative to the conventional pepsin/HCl digestion method several comparative studies were conducted using samples from different muscle sites spiked with low levels of encapsulated first stage Trichinella larvae (L1). Multiple muscle samples were collected from diaphragm, tongue, masseter, and loin of 3–4 month old pigs. Samples were spiked with 3, 4, 5, or 25 Trichinella spiralis L1. A total of 320 meat samples of 100 g each were used to compare the diagnostic proficiency of the PrioCHECK Trichinella AAD assay with the pepsin/HCl digestion method. Comparative and validation data produced from these studies showed that both methods are capable of consistently detecting Trichinella in 100 g samples which contained as few as 3 L1 or 0.03 larvae per gram of meat. Overall, the PrioCHECK Trichinella AAD assay performed satisfactorily according to international guidelines of the World Organization for Animal Health (OIE), European Union (EU) and International Commission on Trichinellosis (ICT) for the detection of Trichinella infection in pork. Keywords: Pork, Food safety, PrioCHECK Trichinella AAD assay, Pepsin/HCl digestion method, Diagnostic assay, Validation

Background Equine piroplasmosis (EP) is an economically significant infection of horses and other equine species caused by the tick-borne protozoa Theileria equi and Babesia caballi. The long-term carrier state in infected animals makes importation of such subclinical cases a major risk factor for the introduction of EP into non-enzootic areas. Regulatory testing for EP relies on screening of equines by serological methods. The definitive diagnosis of EP infection in individual animals will benefit from the availability of sensitive direct detection methods, for example, when used as confirmatory assays for non-negative serological test results. The objectives of this study were to develop a real-time quantitative polymerase chain reaction (qPCR) assay for simultaneous detection of both agents of EP, perform comprehensive evaluation of its performance and assess the assay’s utility for regulatory testing. Results We developed a duplex qPCR targeting the ema-1 gene of T. equi and the 18S rRNA gene of B. caballi and demonstrated that the assay has high analytical sensitivities for both piroplasm species. Validation of the duplex qPCR on samples from 362 competitive enzyme-linked immunosorbent assay (cELISA)-negative horses from Canada and the United States yielded no false-positive reactions. The assay’s performance was further evaluated using samples collected from 430 horses of unknown EP status from a highly endemic area in Brazil. This set of samples was also tested by a single-target 18S rRNA qPCR for T. equi developed at the OIE reference laboratory for EP in Japan, and a previously published single-target 18S rRNA qPCR for B. caballi whose oligonucleotides we adopted for use in the duplex qPCR. Matching serum samples were tested for antibodies to these parasites using cELISA. By the duplex qPCR, T. equi-specific 18S rRNA qPCR and cELISA, infections with T. equi were detected in 87.9% (95% confidence interval, CI: 84.5–90.7%), 90.5% (95% CI: 87.3–92.3%) and 87.4% (95% CI: 84.0–90.2%) of the horses, respectively. The B. caballi prevalence estimates were 9.3% (95% CI: 6.9–12.4%) by the duplex qPCR and 7.9% (95% CI: 5.7–10.9%) by the respective single-target qPCR assay. These values were markedly lower compared to the seroprevalence of 58.6% (95% CI: 53.9–63.2%) obtained by B. caballi-specific cELISA. The relative diagnostic sensitivity of the duplex qPCR for T. equi was 95.5%, as 359 of the 376 horses with exposure to T. equi confirmed by cELISA had parasitemia levels above the detection limit of the molecular assay. In contrast, only 39 (15.5%) of the 252 horses with detectable B. caballi-specific antibodies were positive for this piroplasm species by the duplex qPCR. Conclusions The duplex qPCR described here performed comparably to the existing single-target qPCR assays for T. equi and B. caballi and will be more cost-effective in terms of results turnaround time and reagent costs when both pathogens are being targeted for disease control and epidemiological investigations. These validation data also support the reliability of the ema-1 gene-specific oligonucleotides developed in this study for confirmatory testing of non-negative serological test results for T. equi by qPCR. However, the B. caballi-specific qPCR cannot be similarly recommended as a confirmatory assay for routine regulatory testing due to the low level of agreement with serological test results demonstrated in this study. Further studies are needed to determine the transmission risk posed by PCR-negative equines with detectable antibodies to B. caballi.

The artificial digestion magnetic stirrer method using pepsin protease and hydrochloric acid is the standard assay for the detection of Trichinella larvae in muscle of infected animals. Recently, an alternative enzyme, serine protease, was employed in the development of a commercially available digestion kit (PrioCHECK™ Trichinella AAD Kit). This assay requires a higher digestion temperature of 60°C which kills the larvae during the digestion process, mitigating the risk of environmental contamination from the parasite. The present study was conducted to determine the performance of the PrioCHECK™ Trichinella AAD Kit compared to the conventional pepsin/HCl digestion. Replicate paired 115g samples of Trichinella-negative pork diaphragm and masseter, and of horse tongue and masseter, were used to compare the two methods for tissue digestibility. Similarly, paired 100g samples of pork diaphragm and horse tongue were spiked with proficiency samples containing known numbers of Trichinella spiralis first stage larvae to compare larval recoveries for the two methods. Masseter samples from wild bears and wolves naturally infected with Trichinella nativa or T6 were also used to compare the performance of the methods. The results of the study showed that the PrioCHECK™ Trichinella AAD Kit, when used according to the manufacturer's instructions, was effective in detecting Trichinella infection in all samples that contained 0.05 or more larvae per gram of tissue. Although there was no significant difference between the Kit method and the standard pepsin/HCl digestion procedure in the average number of larvae recovered from spiked pork diaphragm, 38% fewer larvae were recovered from similarly spiked samples of horse tongue by digestion using serine protease (one way ANOVA, P value

Effective performance of digestion testing methods for Trichinella, and their use for the detection of infected animals and the prevention of human trichinellosis require system-wide incorporation of appropriate quality assurance (QA) practices. The recommendations of the International Commission on Trichinellosis (ICT) aim to facilitate reliable test results when laboratories operate within a quality management system (QMS) which includes: 1) a quality manual (or similar documentation of the QMS); 2) a validated test method with identified critical control points; 3) a training program; 4) procedures utilizing proficiency testing and other methods to confirm technical capability of analysts; 5) equipment calibration and maintenance; 6) standard operating procedures, related documentation and reporting; 7) procedures to enable continuous monitoring and improvements; and 8) regular internal and third party audits. The quality manual or similar documentation describes the QMS within a testing laboratory, and lists the QA policies and good laboratory practices. Quality assurance goals contained in such documentation are the foundation of an effective QA program and must be explicit, measurable, and expressed in terms of performance criteria for the test method based on purpose for testing. The digestion method is capable of consistently detecting Trichinella larvae in meat at a level of sensitivity that is recognized to be effective for use in controlling animal infection and preventing human disease. However, consistent performance of the assay is assured only when parameters of the test method have been defined, scientifically validated as fit for purpose, and used within an effective QMS. The essential components of a digestion assay, specifically the critical control points and minimum standards for test performance are described. Reliable proficiency samples and their appropriate use in a quality system are key factors for certifying and maintaining an effective testing laboratory, including qualifying, re-qualifying and disqualifying of analysts as appropriate. Thus recommendations are included for the preparation and use of proficiency samples in a Trichinella digestion testing laboratory. The minimum training requirements for analysts performing a quality assured digestion assay, as well as suggested requirements for the content of a training manual, are also outlined. Finally, these ICT recommendations include essential components and minimum standards for maintaining and achieving certification and maintenance of a laboratory performing digestion testing for Trichinella. The certification program for the laboratory, including qualifying analysts, may be administered by a National Reference Laboratory or an authorized third party certifying body, under the auspices of the appropriate competent authority., Highlights • Quality assurance (QA) is required for reliable digestion testing for Trichinella. • QA in Trichinella testing entails method validation, training and proficiency testing. • QA is essential for Trichinella testing certification programs for food safety purposes.

Understanding parasite diversity and distribution is essential in managing the potential impact of parasitic diseases in animals and people. Imperfect diagnostic methods, however, may conceal cryptic species. Here, we report the discovery and phylogeography of a previously unrecognized species of Trichinella in wolverine (Gulo gulo) from northwestern Canada that was indistinguishable from T. nativa using the standard multiplex PCR assay based on the expansion segment 5 (ESV) of ribosomal DNA. The novel genotype, designated as T13, was discovered when sequencing the mitochondrial genome. Phylogenetic analyses of the mitochondrial genome and of 15 concatenated single copy orthologs of nuclear DNA indicated a common ancestor for the encapsulated clade is shared by a subclade containing Trichinella spiralis and Trichinella nelsoni, and a subclade containing T13 and remaining taxa: T12 + (T2 + T6) + [(T5 + T9) + (T3 + T8)]. Of 95 individual hosts from 12 species of mammalian carnivores from northwestern Canada from which larvae were identified as T. nativa on multiplex PCR, only wolverines were infected with T13 (14 of 42 individuals). These infections were single or mixed with T. nativa and/or T6. Visual examination and motility testing confirmed that T13 is encapsulated and likely freeze-tolerant. We developed a new Polymerase Chain Reaction-Restriction Fragment Length Polymorphism which unequivocally distinguishes between T13 and T. nativa. We propose Trichinella chanchalensis n. sp. for T13, based on significant genetic divergence from other species of Trichinella and broad-based sampling of the Trichinella genome. Exploration of Alaskan and Siberian isolates may contribute to further resolution of a phylogeographically complex history for species of Trichinella across Beringia, including Trichinella chanchalensis n. sp. (T13).

Transmission of Trichinella to domestic livestock, notably pigs, is limited to certain risk factors including feeding of raw meat-containing waste products or animal carcasses and exposure to infected rodents and wildlife. Prevention of infection in food animals is dependent on eliminating risk of exposure to these potential sources of Trichinella. By implementing conditions of controlled management, pig herds can be considered to pose a negligible risk for Trichinella, and groups of herds which follow these same conditions can be considered to be a compartment with negligible risk for Trichinella. Pork from pigs originating from a negligible risk herd or compartment would not require further testing or processing to protect consumers from this parasite. Verifying the status of pigs from a controlled management negligible risk herd or compartment can be accomplished by a program of regular audits or by implementing surveillance testing of a statistical sample of pigs from the herd or compartment., Highlights • Exposure of pigs to Trichinella can be limited in a controlled management system. • Controlled management prevents contact with wildlife, birds and rodents. • Controlled management requires good manufacturing and storage practices for feed. • Verification of controlled management can be achieved by auditing or surveillance. • Pork considered negligible risk does not require testing or processing for Trichinella.

Trichinella spiralis typically infects domestic swine, wild boar and occasionally horses, has a cosmopolitan distribution, and consequently is most frequently associated with food-borne outbreaks of trichinellosis in humans. Trichinella murrelli is typically found in wild carnivores in temperate areas of North America, where it has been responsible for outbreaks of human trichinellosis due to consumption of infected wild game. There has previously been only indirect evidence of natural infection with T. murrelli in a horse originating from Connecticut and implicated in an outbreak of trichinellosis in France in 1985. We describe a T. murrelli infection detected during routine testing of a horse from the USA imported to Canada for slaughter and export to the European Union (EU). Approximately 5 or more larvae per gram were recovered from digested tongue and diaphragm samples and identified as T. murrelli by PCR. This case provides the first direct evidence of naturally acquired T. murrelli infection in a horse, and further supports the potential food safety risk posed by this parasite species. It is the first instance in Canada of the detection of a Trichinella-infected horse via routine post-mortem testing. Trichinella spiralis-infected horses have been similarly detected by regulatory testing in France, and further details of two such previously reported cases are also provided here. The cases described herein underscore the importance of continued vigilance in quality assured food safety testing of horse meat to mitigate the risk of human trichinellosis., Highlights • First direct evidence of natural infection with Trichinella murrelli in a horse • First detection in Canada of a Trichinella-infected horse via regulated testing • Trichinella murrelli should be considered a potential food safety risk in horsemeat. • Horse tongue and diaphragm are effective for detecting T. murrelli and T. spiralis. • Screening of horse carcasses by digestion assay mitigates risk of trichinellosis.

Trichinella is a zoonotic nematode parasite transmitted by the ingestion of raw or under-cooked meat. Control of the parasite is essential to facilitate public health and trade in products from susceptible food animals, including pork and horse meat. The standard method for detecting Trichinella muscle larvae uses pepsin enzyme and hydrochloric acid (HCl) in an artificial digestion procedure. A new artificial digestion assay using serine protease was recently developed and commercialized (PrioCHECK™ Trichinella AAD) for the detection of Trichinella larvae in the muscle of infected animals. The assay uses no hazardous substances such as HCl or pepsin. Activation of the enzyme requires an elevated digestion temperature of 60 °C which kills the parasite and reduces the risk of contaminating the environment with Trichinella. Compared to the pepsin/HCl method, digestion time for the PrioCHECK Trichinella AAD assay is reduced by a third. A recent study demonstrated these features of the new assay and its suitability for digesting various muscles from domestic and wild animals. To further validate the assay's performance relative to the conventional pepsin/HCl digestion method several comparative studies were conducted using samples from different muscle sites spiked with low levels of encapsulated first stage Trichinella larvae (L1). Multiple muscle samples were collected from diaphragm, tongue, masseter, and loin of 3–4 month old pigs. Samples were spiked with 3, 4, 5, or 25 Trichinella spiralis L1. A total of 320 meat samples of 100 g each were used to compare the diagnostic proficiency of the PrioCHECK Trichinella AAD assay with the pepsin/HCl digestion method. Comparative and validation data produced from these studies showed that both methods are capable of consistently detecting Trichinella in 100 g samples which contained as few as 3 L1 or 0.03 larvae per gram of meat. Overall, the PrioCHECK Trichinella AAD assay performed satisfactorily according to international guidelines of the World Organization for Animal Health (OIE), European Union (EU) and International Commission on Trichinellosis (ICT) for the detection of Trichinella infection in pork., Graphical abstract Unlabelled Image, Highlights • A new serine artificial digestion assay has been validated to test pork for Trichinella. • The assay detected Trichinella from all 160, 100 g samples containing 3, 4, 5, or 25 larvae • As few as 0.03 larvae per gram were detected using spiked samples from four muscle sites • PrioCHECK Trichinella AAD and pepsin/HCl methods are comparable for detecting Trichinella in pork

A portable, modular, plug-and-play photovoltaic (PV) converter system is proposed in this paper. Each PV subpanel has an individual DC/DC converter connected in parallel to a semi-regulated DC bus. In order to accommodate diverse loads, a distributed control strategy for each converter is utilized so that the PV subpanel can operate at either Maximum Power Point Tracking (MPPT) mode or power shedding mode. No master-slave control scheme is used, therefore all master Central Processing Units (CPUs) and communication wires are eliminated, making the system inexpensive and mechanically resilient. The presented system is compatible with various types of PV subpanels and the reliability is enhanced. Experimental results are provided to present the concept and verify the effectiveness of this method.

A modular plug-and-play photovoltaic (PV) converter system for portable PV applications is proposed. Small subpanel of PV cells have individual dc/dc converters performing distributed maximum power point tracking. The dc/dc submodules are connected in parallel to a DC bus. Challenges for the proposed PV system to accommodate diverse types of loads are addressed. Based on scenario analysis, the operating mode and the operating range of the PV system are illustrated. A peerto- peer control strategy is developed to maintain stable power supply automatically with PV power and/or load power changing. The DC bus is semi-regulated in accordance with different operating scenarios. The presented system features advantages of 1) compatibility of various types of PV subpanels (different chemistry, power levels, and operating characteristics); 2) capability of drawing higher power from mismatched PV subpanels; 3) high reliability due to its parallel structure and peer-to-peer operating mechanism. A prototype of the system has been developed in the lab, and experimental results are provided to verify the method.

Seroconversion and cross-reactivity in cattle infected with Anaplasma marginale or a recently described Ehrlichia species (BOV2010 from British Columbia, Canada) were investigated. The study used 76 samples from 20 animals, a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for bovine anaplasmosis, and an indirect fluorescent antibody test (IFAT). Blood smear examination and/or polymerase chain reaction assay were performed to confirm or rule out the presence of Anaplasma or Ehrlichia. Samples comprised 3 groups. Group 1 consisted of 24 samples from 9 cattle naturally infected with Ehrlichia sp. BOV2010. Group 2 had 13 samples from 3 A. marginale–infected cattle from Manitoba, Canada. Group 3 had 39 samples, consisting of 26 from 5 calves experimentally infected with Ehrlichia sp. BOV2010, 10 from 2 calves experimentally infected with A. marginale from cattle (Manitoba) or bison (Saskatchewan), and 3 from an uninfected calf. All samples from cattle naturally or experimentally infected with Ehrlichia sp. BOV2010 or A. marginale were seropositive for A. marginale by both cELISA and IFAT, except 3 calves euthanized at 28 and 33 days post-inoculation (DPI) that did not seroconvert. Antibodies were detected in 2 experimental animals inoculated with Ehrlichia sp. BOV2010, as early as 28 and 33 DPI by the cELISA and IFAT, respectively, and by 42 DPI for both tests. The current study demonstrates that the specificity of the recombinant major surface protein 5 (MSP5) antigen is not restricted to Anaplasma spp., which reduces the utility of the test for serological diagnosis of bovine anaplasmosis in regions where Ehrlichia sp. BOV2010–infected cattle might exist.

During a research investigation to determine if cattle from British Columbia (BC), Canada were infected with Anaplasma marginale or other related rickettsial blood parasites, a novel Ehrlichia genotype was revealed. Blood from seven BC source cattle was bioassayed by intravenous inoculation into naïve splenectomised calves. Additional splenectomised calves were used as uninoculated negative control or A. marginale-inoculated positive control. Newly designed sets of primers specific for the msp5 gene of A. marginale or for the 16S rRNA gene were used to test blood samples collected from all source cattle and from all recipient calves prior to inoculation and up to 72 days post-inoculation. Results of the PCR assays as well as microscopic examination of stained blood smears failed to demonstrate A. marginale in any of the animals except for the positive control. The 16S rRNA PCR primers amplified DNA from samples from all BC source cattle, five of six of the corresponding recipient calves, and the A. marginale infected control animal. DNA sequence data indicated the presence of A. marginale only in the positive control calf. Blast analysis in GenBank showed that sequences of all other 16S rRNA PCR products clearly fit within the Ehrlichia genus in the Anaplasmataceae family which also includes members of the genus Anaplasma. Phylogenetic analyses using the 16S rRNA gene sequences strongly support the putative Ehrlichia organism as a distinct genotype with sequences of various strains of Ehrlichia canis as the closest clade. Ehrlichia ruminantium is the only other species of the genus known to naturally infect cattle, apart from the present Ehrlichia isolate. However, within the genus, E. ruminantium is phylogenetically the furthest removed species from the novel genotype. The finding of this novel Ehrlichia represents the first known natural ehrlichial infection in cattle in North America. Nevertheless, it is unclear whether cattle are an incidental or primary host, particularly since deer are recognized as reservoir hosts for other species of Ehrlichia. Although other Ehrlichia spp. are known to be pathogenic for animals and zoonotic, these features are presently unknown for this novel genotype.

Bovine cysticercosis caused by Taenia saginata is a zoonotic disease warranting routine inspection measures for the postmortem detection of cysticerci (cysts) in beef destined for human consumption. Detection is based on gross examination of traditional carcass predilection sites, although there is evidence to suggest that examination of other sites may offer improvements in sensitivity. In order to evaluate the efficacy of current inspection protocols, this study determined the distribution and number of cysticerci in the tissues of experimentally infected cattle. Forty-two commercial beef cattle were divided into five groups of 5-12 animals each and inoculated with either 10,000, 5000, 1000, 100 or 10 T. saginata eggs. At time points ranging from 47 to 376 days post-inoculation (DPI), 10 animals inoculated with 5000 eggs were killed and the carcasses partitioned into 31 tissue sites. These consisted of the traditionally inspected tissue sites of heart, masseter and pterygoid muscles, tongue, oesophagus, and diaphragm (membranous and crura); as well as non-traditional sites of lung, liver and an additional 20 individual muscles or muscle groups. After performing the Canadian Food inspection Agency's (CFIA) routine inspection protocol for cysticerci on traditional tissue sites, tissues from all sites were cut into approximately 0.5 cm thick slices and the total number of parasitic cysts and cyst density (number of cysts/g of tissue) determined for each site. Traditional sites were similarly evaluated for the remaining 32 animals killed between 117 and 466 DPI. Sites were ranked based on cyst density. Infection was confirmed in 37 animals, of which only 20 were detected by routine inspection, and of which 7 harboured no cysts in traditional sites. For the animals in which additional non-traditional sites were evaluated, none yielded higher cyst densities than those traditionally inspected. When only traditional sites (for all animals) were compared, the heart ranked highest overall, although it was not significantly different from the masseter muscle, and was the most frequently affected site. The traditional site of oesophagus was one of the least rewarding of all sites for detection of cysticerci. The heart was confirmed as the preferred site for detection of bovine cysticercosis based on high cyst density and frequency of infection, and greater visibility of gross lesions due to the early inflammatory response in cardiac muscle. More extensive examination of the heart is recommended to improve detection of infected animals.

The Canadian Food Inspection Agency (CFIA) has developed a program to accredit external laboratories to conduct Trichinella digestion assays for export purposes. Accredited laboratories are responsible for staffing, equipment and operating test facilities under the auspices and guidance of the CFIA. The CFIA's Centre for Animal Parasitology provides training, proficiency samples, audits and other support for the accreditation process. The program has also been adapted for use in laboratories conducting Trichinella digestion tests for surveillance and food safety purposes and provides a useful template for others wishing to develop similar systems.

Power film and its partners have developed a Generation II PowerShade which meets or exceeds the goals of this development contract, increasing power and improving the ROI of the power shade significantly while improving a number of the human factors. Comparing the Gen II 1.8 KW PowerShade to the equivalent power Gen I unit (Gen I Medium), The cost has been reduced from $38,000 to $28,000 or by 26.3%. This is as compared to the Threshold goal of 20% and Objective of 30%. Output power per unit area increased 36% from 2.04W/sq ft to 2.78W/sq ft compared to a Threshold goal of 10% and Objective of 20%. The Specific Power (KW/lb) increased 74% from 3.9W/lb to 6.8 W/lb. While the weight reduction per Watt was not a stated goal, it is an important metric for usability. Lifetime has been increased from 3 years to the objective of 10 years. When all these improvements are taken into account and the PowerShade is used in optimum conditions, the crossover point relative to diesel generators comes at approximately $3.61 cost for the diesel fuel. This would give the PowerShade a positive return on investment for a wide range of installations.

Motile Tritrichomonas foetus-like trichomonads were found during microscopic examination of a wet mount sample of a preputial wash collected from a bull. Staining of the organisms with a modified Wright-Giemsa stain revealed that several had four anterior flagella of unequal length instead of the three anterior flagella of equal length characteristic of T. foetus. Limited propagation of these organisms was achieved in InPouch® medium but no growth occurred in modified Diamond's medium. The 5.8S rRNA gene and the flanking internal transcribed spacers were amplified from the trichomonad gDNA of two preputial wash samples and a fecal sample taken from the affected bull. Amplicons were subjected to single-strand conformation polymorphism (SSCP) analyses. The SSCP banding patterns of the amplicons from gDNA of the preputial wash samples were different from those of a T. foetus control sample. These unknown trichomonads were not detected in the fecal sample. The gDNA extracted from preputial washes was also subjected to PCR using primers developed to amplify the 16S rDNA of the non-T. foetus trichomonads, Tetratrichomonas and Pentatrichomonas spp. Amplicons were produced from the gDNA of the two preputial washes but not from the T. foetus gDNA control sample. The 16S rDNA sequences obtained from the trichomonads in the two preputial washes samples were 100% similar to that of a Tetratrichomonas species previously isolated from an Angus bull from the United States.

International audience; Routine diagnosis of animal trichinellosis for food safety and trade relies on a method of artificial digestion to free Trichinella muscle larvae from meat for subsequent identification by microscopy. As part of a quality control system, the French National Reference Laboratory (NRL) initiated ring trials to determine the sensitivity of the test performed in the 72 routine diagnostic laboratories in France. A method was devised to obtain calibrated meat samples containing known numbers of capsules with Trichinella spiralis muscle larvae. This method was based on an incomplete artificial digestion of Trichinella-infected mice carcasses to allow the collection of intact Trichinella capsules. Capsules were placed into a meatball of 100 +/- 2 g of pork and horsemeat to produce proficiency samples. Three categories of samples were prepared: small (3 to 5 capsules), medium (7 to 10), and large (12 to 15). The sensitivity was expressed as the percentage of muscle larvae recovered from each proficiency sample. Reproducibility was tested with ring trials organized between two NRLs (France and Canada), and a reference sensitivity of 84.9% was established. National ring trials were then organized in France, with the 72 routine diagnostic laboratories each receiving four proficiency samples per session. After five sessions, an improvement in the digest test sensitivity was observed. Results at the fifth session indicated sensitivities of 78.60% +/- 23.70%, 81.19% +/- 19.59%, and 80.52% +/- 14.71% muscle larvae for small, medium, and large samples, respectively. This study supports the use of proficiency samples to accurately evaluate the performance of routine diagnostic laboratories that conduct digestion tests for animal trichinellosis diagnosis.

We report a case of malignant melanoma in a captive red deer (Cervus elaphus elaphus). The primary lesion was on the plantar aspect of the right pastern and infiltrated the surrounding skin, but not underlying tendons or bone. Diffuse metastasis to the regional lymph nodes had occurred. Histologically, lesions were characterized by large numbers of variably pigmented epithelioid cells with a high degree of nuclear atypia and many mitotic figures. This is the first reported case of this neoplasm in red deer.

A study was undertaken to determine whether domestic goats can serve as patent hosts of Elaphostrongylus cervi under natural or experimental conditions. Three-hundred and two fecal samples from 124 domestic goats raised outdoors in New Zealand, where E. cervi is enzootic, were tested for nematode larvae by the Baermann method. All samples were negative for E. cervi dorsal-spined larvae. Twenty juvenile male Nubian and Saanen goats obtained locally were assigned randomly to 5 dosage groups and were orally administered 5, 15, 35, 65, or 125 third-stage larvae of E. cervi, respectively. Two yearling female red deer (Cervus elaphus elaphus) each received 35 or 65 third-stage larvae as positive controls, and 2 uninoculated juvenile male goats served as negative controls. Fecal Baermann testing of pooled samples from the inoculated goats was conducted weekly for the first 80 days postinoculation (DPI) and daily thereafter until 250 DPI. No dorsal-spined larvae were recovered. One goat that had received 15 third-stage larvae displayed a mild transient posterior ataxia suggestive of cerebrospinal elaphostrongylosis. Gross postmortem examination did not reveal any direct evidence of nematodes in any of the goats, and only a few minor lesions were present. Histologically, these lesions were consistent with a parasite etiology. Histological evaluation of grossly normal lumbar and sacral spinal cord from 2 goats that had each received 125 third-stage larvae revealed eosinophilic meningoencephalitis and leukomyelitis, respectively, suggestive of the presence of parasites in the central nervous system. The 2 positive control red deer became patent with dorsal-spined larvae consistent with E. cervi at 131 DPI. These findings suggest that goats, at least those breeds utilized in this study, are not suitable patent hosts for E. cervi.