Marina Spinu

Immune response to fleas in a wild desert rodent: effect of parasite species, parasite burden, sex of host and host parasitological experience

SUMMARY We studied immune responses of the jird Meriones crassus to different flea species belonging to the same family. We used jirds maintained in an outdoor enclosure (enclosure; N=18) and parasitized by fleas Xenopsylla conformis mycerini and Xenopsylla ramesis, and also jirds born in the laboratory to previously parasitized mothers (laboratory animals; N=23). We asked (i) whether cross-immunity to different fleas occurs, (ii) whether there is a sex difference in immune responses to flea parasitism and (iii) whether the severity of the immune responses depends on parasite load. In the enclosure animals, immune response to antigen from the unfamiliar flea Synosternus cleopatrae pyramidis did not differ from those to antigens from the familiar fleas. In contrast, laboratory rodents demonstrated no difference in the immune response between S. c. pyramidis antigen and either the phytohemagglutinin treatment or controls, although their responses to antigens of fleas familiar to their mothers (X. c. mycerini and X. ramesis) were significantly higher than those to antigen of S. c. pyramidis and phytohemagglutinin. The results clearly demonstrated that (i) cross-reactivity in rodent responses to different flea species occurred for enclosure but not for laboratory jirds and (ii) immune-naïve animals whose mothers were parasitized by fleas had some degree of immunity against fleas. The only sex difference in immunological parameters was the higher level of circulating immune complexes in females than in males. Only phagocytic activity was affected by flea burden, decreasing with an increase in flea numbers.

Immune responses to fleas in two rodent species differing in natural prevalence of infestation and diversity of flea assemblages

We studied in vitro immune response to fleas in two gerbils, Gerbillus dasyurus and Gerbillus andersoni allenbyi, which differed in their natural species richness of flea assemblages and prevalence of infestation. G. dasyurus is parasitized naturally by several flea species, but the prevalence of infestation is low, whereas G. a. allenbyi is parasitized by a single flea species, with high prevalence of infestation. We hypothesized that immunological parameters and the cell-mediated specific immune response to an antigen from an unfamiliar flea species differ between the two gerbil species. Parasitized and control gerbils of both species demonstrated similar, relatively low levels of spontaneous glucose consumption. The same was true for the phytohemagglutinin treatment. Responses to antigen from unfamiliar flea species were higher than both spontaneous glucose consumption and response to phytohemagglutinin in parasitized and control G. a. allenbyi and parasitized G. dasyurus. However, no significant difference in the spontaneous blast transformation index and responses to both phytohemagglutinin and flea antigen was found in control G. dasyurus. The number of white blood cells was significantly lower in control than in parasitized G. dasyurus, whereas no difference in the number of white blood cells was found between control and parasitized G. a. allenbyi. The levels of circulating immune complexes and concentrations of immunoglobulins did not differ between parasitized and control individuals in both species. Phagocytic activity was significantly higher in males than in females of G. a. allenbyi but not of G. dasyurus. In addition, phagocytes of G. dasyurus appeared to be significantly more active than those of G. a. allenbyi.

Tick prevention at a crossroad: new and renewed solutions.

Ticks have major economic impact through diseases they transmit, direct losses due to their detrimental effect and the efforts invested in prevention measures directed against them. Chemical acaricides represent the main line of anti-tick defense in both humans and domestic animals, but increasing concerns regarding development of acaricide resistance, especially in the cattle tick Rhipicephalus microplus, and environmental safety issues indicate the need for other, less aggressive but equally efficient methods. This paper aims to evaluate the potential, the scientific and economical limitations and future research directions regarding different alternative methods of tick control and their use in integrated pest management, with a separate reference to the pet industry. New research data in each field is presented and the economical aspects for each approach are individually emphasized.

Distribution and genetic diversity of porcine hokovirus in wild boars

Porcine hokovirus (PHoV), a newly discovered member of the family Parvoviridae and the proposed genus Hokovirus, is considered phylogenetically distinct from other parvoviruses. Here, we report a comprehensive spatio-temporal study of PHoV infection in Romanian wild boars. The prevalence of PHoV differed significantly in samples from 2006/2007 (22.76%) and 2010/2011 (50.54%), and also increased with age. Sequence analysis of PHoVs from 2006/2007 showed a close relationship to PHoVs from pigs from England and wild boars from Germany, while the PHoVs from 2010/2011 were mostly similar to isolates from Hong Kong. The most variable regions were detected in the NS1 gene and proved to be suitable for analysis of the genetic diversity of the virus. It was observed that PHoVs from older wild boar samples differed from those collected recently. These results suggested that porcine hokovirus could be a newly emerging virus of both domestic and wild pigs with yet unknown implications.

Detection of natural inter- and intra-genotype recombination events revealed by cap gene analysis and decreasing prevalence of PCV2 in wild boars.

Porcine circovirus type 2 (PCV2), the causative agent of a number of PCVAD (porcine circovirus associated diseases), is ubiquitous in domestic pig and wild boar populations. In the present study, using recombination detection program, phylogenetic analysis and base-by-base comparison of 28 PCV2 ORF2s (capsid protein coding gene) from wild boars and 8 from domestic pigs of Transylvania, recent natural intra- (PCV2b-1B/PCV2b-1C) and inter-genotype (PCV2a-2D/PCV2b-1C) recombination events were detected. Notably, one potential recombinant (F1-21) was detected in domestic pig with possible parental strains of wild boar origin. The estimated recombinant breakpoints comprised epitopes A, B and C of ORF2, without major changes in amino acid sequences. The prevalence of PCV2 in the wild boar population during the 5-year period following the first outbreaks of postweaning multisystemic wasting syndrome (PMWS) in domestic pigs in Romania showed a decrease from 13.4% to 8.3%. To our knowledge, this is the first study to show the existence of ORF2-based intra- and inter-genotype recombination in wild boar populations and the possible recombination between PCV2 strains of wild boars and domestic pigs. Our results suggest a certain independence of PCV2 infection in wild boar populations and demonstrate the possibility of infection with multiple PCV2 genotypes under natural circumstances. On the other hand, PCV2 genotypes specific for wild boars could be detected in domestic pig at lower frequency suggesting the possible spread of wild boar PCV2 to domestic swine. The recombination events described here may contribute to the genetic diversity of PCV2 and may also be the source of emergence of new PCV2 strains.

Dairy cows welfare quality in tie-stall housing system with or without access to exercise

BackgroundTie-stall housing of dairy cows is used extensively worldwide, despite of the welfare concerns regarding the restriction of voluntary movement and limitation of expression of the cows’ natural behaviour. The aim of this study was to compare the welfare quality of dairy cows kept in two types of tie-stall housing systems: with regular outdoor exercise and without access to exercise. In addition, the study investigated the relationship between different welfare measures of dairy cows kept in tie-stalls.Methods3,192 lactating cows were assessed using the Welfare Quality® assessment protocol for cattle in 80 commercial dairy farms, half of the farms providing outdoor access for the animals to exercise. The descriptive statistical indicators were determined for the assessed measures and for the welfare criteria and principle scores. The data obtained in the two housing types were compared and the correlation coefficients were calculated between the different welfare measures.ResultsThe significant differences found between the two housing systems for the majority of the animal based measures indicate the positive effect of exercise on the welfare of tethered cows. Many of the animal welfare parameters correlated with each other. For the farms allowing the cows’ turnout in a paddock, pasture or both, the mean scores for the welfare criteria and principles were higher than for the farms with permanent tethering of the cows, except the criteria absence of prolonged hunger and expression of social behaviours. The lowest scores were obtained for the criterion positive emotional state, in both housing systems. With regard to the overall classification, none of the farms were considered excellent. In the not classified category were only farms with all-year-round tethering of the animals and in the enhanced category only farms where the cows had outdoor access.ConclusionsThe welfare quality of the investigated dairy cows was significantly better in the tie-stall farms which allow exercise for cows (paddocks, pasture or both) than in those which do not. In the light of our results we consider that dairy cattle welfare is not necessarily poor in tie-stall housing systems, its quality depending on the management practices.

Human impact on the microbiological water quality of the rivers

Microbiological contamination is an important water-quality problem worldwide. Human impact on this category of contamination is significant and several human-related activities, and also the population explosion, have affected and are still affecting dramatically the aquatic environment. Extensive industrialization and agriculture have led to increased pollution and hydromorphological changes in many river basins. The Danube river is one of the most affected by these changes where human involvement is undeniable, and subsequently, the Danube Delta Biosphere Reserve became one of the most vulnerable ecosystems. This review is an attempt to analyse the microbiological contamination and to identify the major role human activities play in altering the water quality of the rivers.

Phylogeny and evolutionary genetics of porcine parvovirus in wild boars

Porcine parvovirus (PPV) is widespread among swine and is responsible for reproductive failure of susceptible sows, characterized by embryonic and fetal death. Studies showed that PPV in domestic pig is genetically diverse and some strains differ from the ones used for vaccination. Organ samples from wild boars and domestic pigs were collected in Transylvania (Romania) and tested for the presence of PPV by polymerase chain reaction. Positive samples were grouped and 14 from the wild boar and 1 from the domestic pig PPVs were selected for VP1/VP2 sequence analysis and comparison with available GenBank data. The molecular clock analysis revealed that PPV has a relatively recent evolutionary history, originated approximately 120 years ago and the main divergence occurred in the last 20-60 years. Phylogenetic and residue substitution analysis showed that the viruses could be divided into 6 distinct clusters and that wild boar PPVs were partially different and independent from domestic pig PPVs. PPVs of wild boars proved to be more diverse than viruses of domestic pigs. The presence of the highly virulent 27a-like PPV strains in wild boars was also detected.

The interrelations of good welfare indicators assessed in working horses and their relationships with the type of work.

This paper presents a different approach to the welfare of working horses through the indicators of good welfare, their interrelations and their relationships with the type of work performed by the horses. 697 working horses were assessed by using observation, behavioural tests, clinical exams and questionnaires. The correlated results highlight the complex and multiple interrelations between the good welfare indicators, showing once again that animal welfare is under the influence of all its three dimensions (physical and emotional wellbeing and naturalness). In working horses, the heavier the work they perform is, the more important it is for horse owners/breeders/farmers to fulfil their inherent needs so as to help them cope with the multiple specific risks imposed by their work.

Serological Reactivity to Borrelia burgdorferi Sensu Lato in Dogs and Horses from Distinct Areas in Romania

Lyme disease is a perfect model of the complex relationship between host, vector, and the vector-borne bacteria. Both dogs and horses in Romania are exposed to infection. The aim of the present study was to assess the seroreactivity against Borrelia burgdorferi sensu lato in dogs and horses from different regions of Romania. 276 samples from dogs and 260 samples from horses located in different regions of Romania were analyzed by ELISA and IFA, respectively. The effect of several factors potentially affecting seroreactivity (location, age, gender, occupation, and vector exposition risk) was evaluated using Fishers exact test (R 2.12.0). The overall prevalence of anti-Borrelia antibodies was 6.52% (18/276) in dogs, with a significantly higher positivity (46.15%, 6/13, p = 0.0005) recorded in a midcountry region. Seroreactivity was correlated with occupation, with working dogs being more exposed. The results may indicate that Lyme borreliosis foci are restricted to small areas, but further studies on Borrelia prevalence in tick populations are needed to confirm this hypothesis. In horses, a global seroprevalence of 11.92% (31/260) was observed. No correlations were found between positive results and age, sex, county, or occupation. This is the first serological survey on antibodies to B. burgdorferi sensu lato in Romanian dogs and horses.