Presence and diversity of mixed avian Plasmodium spp. infections in introduced birds whose distribution overlapped with threatened New Zealand endemic birds

ABSTRACT

Aims: To determine the presence of infection and co-infection of Plasmodium lineages in introduced birds at translocation sites for the North Island saddleback (Philesturnus rufusater), to investigate their role as Plasmodium spp. reservoirs.

Methods: Blood samples were collected from introduced bird species, with a special focus on blackbirds (Turdus merula) and song thrushes (Turdus philomelos), at six locations in the North Island of New Zealand that were the origin, or translocation sites, for North Island saddleback. Where available, blood smears were examined, and blood samples were tested using nested PCR with subsequent sequence analysis, for the presence of Plasmodium spp.

Results: Of the 55 samples tested using PCR analysis, 39 (71%) were positive for Plasmodium spp., and 28/40 (62%) blood smears were positive for Plasmodium spp. Overall, 31 blood samples were from blackbirds with 28/31 (90%) samples positive for Plasmodium spp. Six distinct avian Plasmodium lineages were identified, including three cosmopolitan lineages; Plasmodium vaughani SYAT05 was detected in 16 samples, Plasmodium matutinum Linn1 in 10 samples and Plasmodium elongatum GRW6 in eight samples. Mixed infections with more than one lineage were detected in 12 samples. Samples from two Australian magpies (Gymnorhina tibicen) were positive for Plasmodium. sp. lineage MYNA02, previously not identified in New Zealand.

Conclusions and clinical relevance: This is the first report from New Zealand in which specific Plasmodium spp. mixed infections have been found in introduced birds. Co-infections with several cosmopolitan Plasmodium lineages were identified, as well as the first report in New Zealand of an exotic avian Plasmodium sp. lineage, in Australian magpies. Whilst the role of introduced birds in maintaining and spreading pathogenic avian malaria in New Zealand is unclear, there is a potential infection risk to native birds, especially where distributions overlap.     

Two Methods of Vitrification Followed by In Vitro Culture of the Ovine Ovary: Evaluation of the Follicular Development and Ovarian Extracellular Matrix

The aim of this study was to evaluate the influence of two vitrification techniques on the extra cellular matrix (ECM) and ovarian follicular development. The ovarian cortex was fragmented (9 mm³) and divided into six groups, viz. fresh control, cultured control, vitrified by the Ovarian Tissue Cryosystem (OTC) method, conventional solid surface vitrification (SSV) method, OTC/cultured and SSV/cultured. Follicles from all the fragments were analysed for morphology, development and viability. The ECM was evaluated based on the condition of collagen and reticular fibres and the immunolocalization of type I collagen and fibronectin. After 7 days of culture, the tissue vitrified by OTC revealed a higher percentage (p < 0.05) of morphologically normal (30.66%) and viable (60.00%) follicles when compared with those vitrified using the SSV technique (21.33% and 23.00%). In all the fragments cultured, regardless of the vitrification method, a significantly higher percentage of developing follicles was observed when compared with the non‐cultured tissue. Analysis of the type I collagen showed increased immunostaining after the in vitro culture in the vitrified fragments. In conclusion, the OTC is better for preserving the follicular viability and morphology and maintaining the integrity of the extracellular matrix components of the ovine ovary.     

The effects of diet and age on serum complement system activity in goat kids

Thirty new born male kids were allotted into three groups to evaluate the effects of diet and age on complement system activity in serum. After the colostrum feeding period, the control group (C) received a commercial milk replacer; the CLA group received 20 g/kg milk replacer DM of conjugated linoleic acid; and the GMK group was fed with goat milk. The kids were fed colostrum for 2 days and then either milk replacer or goat milk from days 3 to 60. Blood samples were taken at 1, 10, 20, 30, 40, 50 and 60 days of age. The complement system activity was higher (P < 0.05) in the GMK group throughout the whole experiment through alternative pathway. C kids did not present complement activity at any time. CLA group complement activity was statistically higher than that of C kids from 30 to 60 days, through alternative pathways. In conclusion, the milk replacer formula should be reformulated because it did not induce any complement system activity in the first two months of life.     

Vaccination strategies with oral booster for surubim hybrid (Pseudoplatystoma corruscans × P. reticulatum) against haemorrhagic septicaemia

This study evaluated the efficiency of differently prepared vaccines against Aeromonas hydrophila in the hybrid surubim (Pseudoplatystoma corruscans × P. reticulatum). Survival and haemato‐immunological parameters were compared between the treatments: non‐vaccinated fish (C); bacterin‐vaccinated fish (B); bacterin plus oral booster vaccinated fish (B+O); bacterin and toxoid‐vaccinated fish (B+T) and bacterin, toxoid and oral booster‐vaccinated fish (B+T+O). Fourteen‐days vaccinated fish from B+O and B+T+O were fed with an oral booster for 4 days. After 1 week, the fish were intraperitoneally challenged with 2 × 10⁸ CFU mL^?1 of A. hydrophila. Fish from the treatment B+T+O showed the lowest cumulative mortality (11.36%) 96 h after challenge, compared with other treatments (22.72–44.04%), and a relative survival of 74%. Serum immunoglobulin in B+T+O fish was higher than in other treatments. All vaccinated fish showed an increased agglutination titre when compared with non‐vaccinated fish, both before and after challenge. Fish fed with oral booster showed an increase in phagocytic percentage before and after challenge. It can be inferred that the oral booster vaccination was efficient in reducing mortality in hybrid surubim by enhancing the response against haemorrhagic septicaemia due to A. hydrophila infection.     

Do metal contamination and plant species affect microbial abundance and bacterial diversity in the rhizosphere of metallophytes growing in mining areas in a semiarid climate?

Journal of Soils and Sediments - Mining areas are low-quality habitats for macro- and microorganisms’ development, mainly due to the degradation of the soil quality by metal pollution. The...     

Influence of the Preservation Temperature (37, 20, 4, −196°C) and the Mixing of Semen over Sperm Quality of Majorera Bucks

This study assessed the effect of different semen storage temperatures and the influence of semen pooling in semen viability. In experiment 1, semen samples (n = 30) of five Majorera bucks were individually processed [Individual semen (IS)] and after the first dilution (Tris‐yolk extender), semen‐diluted aliquots from each male were pooled semen (PS). Thereafter, semen samples (IS and PS) were preserved as fresh semen (37 and 20°C), chilled semen (4°C) and frozen semen. Sperm motility and the percentage of abnormal sperm cells and intact membrane acrosomes were defined. Semen preservation at 20 and 4°C did not modify the quality of spermatozoa for the first 24 h, but the conservation at 37°C caused a dramatic fall in the semen motility from 12 h onwards. Furthermore, the longevity of frozen‐thawed semen was limited to 4–6 h. No differences were observed in semen parameters when PS was compared with semen from individual males in any of the preservation protocols assessed. In experiment 2, 120 goats were distributed in four experimental groups: in group fresh individual semen (FIS, n = 30) and group frozen‐thawed individual semen (FTIS, n = 30), does were transcervically inseminated with fresh semen and frozen‐thawed semen from each individual male, respectively, and in group fresh pooled semen (FPS, n = 30) and group frozen‐thawed pooled semen (FTPS, n = 30), goats were transcervically inseminated with FPS and FTPS, respectively. The kidding rate was very close in the FIS and FPS groups (70.0% and 73.7%, respectively), and no significant differences were observed in the fertility rate between FTIS and FTPS. The results of this study confirmed that semen samples may be preserved satisfactorily for 24 h both at 20 and 4°C. In addition, the mixture of semen of different bucks did not significantly modify the semen parameters when compared with semen from individual males.     

Personal and household factors involved in recent Rickettsia exposure in a rural population from Yucatán,Mexico

The aim of the study was to describe the epidemiological factors associated with the risks of recent Rickettsia exposure in inhabitants of a rural population from Yucatán, Mexico. The study included 130 inhabitants from Maxcanú, Yucatán. Blood samples were collected to detect IgM and IgG antibodies against Rickettsia typhi and Rickettsia rickettsii by an indirect immunofluorescence antibody test. Additionally, nested polymerase chain reaction was performed to amplify fragments of the 17kDa and sca5 genes. Previously, an epidemiological questionnaire was applied focused on collecting information on personal and housing exposure variables related to the recent infection with Rickettsia to determine epidemiological associations. Results that exhibited a p‐value < .25 were included in a generalized multinomial logistic linear model to determine the variables involved with the risk of contact or Rickettsia infection. In all, 76% (99/130) of the participants presented with immunoglobulin titres against the Rickettsia species evaluated, while rickettsial DNA was detected in 35.4% (46/130) of the participants. The association analysis with the personal exposure variables showed that the productive age group (OR = 0.32; 95% CI = 0.10–1.03) and the elders group (OR = 0.12; 95% CI = 0.01–0.83) were protective factors for recent infection with R. typhi, taking as reference the school group. The presence of a family orchard in the home (OR = 7.56; 95% CI = 1.62–35.29) was a risk factor for recent infection with R. rickettsii. Presumably, the presence of ectoparasites (OR = 2.71; 95% CI = 0.90–8.09) at home was a risk factor for recent infection with both Rickettsia species. Recent infection was demonstrated in inhabitants from Maxcanú, Yucatán. A high seropositive frequency was obtained. The results highlight the importance of the family garden and the presence of ectoparasites in the home as risk factors associated with recent infection with Rickettsia in inhabitants from Maxcanú.     

In vitro microbial protein synthesis,ruminal degradation and post‐ruminal digestibility of crude protein of dairy rations containing Quebracho tannin extract

This study evaluated the effects of Quebracho tannin extract (QTE) on in vitro ruminal fermentation, chemical composition of rumen microbes, ruminal degradation and intestinal digestibility of crude protein (iCPd). Three treatments were tested, the control (basal diet without QTE), the basal diet with 15 g QTE/kg dry matter (DM) and the basal diet with 30 g QTE/kg DM. The basal diet contained (g/kg DM): 339 grass silage, 317 maize silage and 344 concentrate. In vitro gas production kinetic was determined using the Hohenheim gas test (Experiment 1). The Ankom RF technique, a batch system with automatic gas pressure recordings, was used to determine in vitro production of short‐chain fatty acids (SCFA) and ammonia–nitrogen concentration (NH₃‐N), as well as nitrogen and purine bases content in liquid‐associated microbes (LAM) and in a residue of undegraded feed and solid‐associated microbes (Feed+SAM) (Experiment 2). Ruminal degradation and iCPd were determined using the nylon bag technique and the mobile nylon bag technique, respectively (Experiment 3). Gas production (Experiment 1), total SCFA and NH₃‐N (Experiment 2) decreased with increasing QTE levels. Microbial mass and composition of LAM were not affected by QTE, but total mass of Feed+SAM linearly increased, likely due to decreased substrate degradation with increasing QTE levels. The total amount of N in microbial mass and undegraded feed after the in vitro incubation increased with increasing QTE levels, suggesting a potential greater N flow from the rumen to the duodenum. In contrast to in vivo studies with the same QTE, no effects were detected on ruminal effective degradability and iCPd, when using the nylon bag techniques. Based on the in vitro procedures, QTE increased the supply of N post‐rumen; however, some evidence of a decreased fibre degradation were also observed. Therefore, the benefit of adding QTE to diets of cattle is still questionable.     

Stones and Organic Mulches Improve the Quercus Ilex L. Afforestation Success Under Mediterranean Climatic Conditions

This work studies the influence of two mulching treatments on soil properties and the field performance of afforested holm‐oak seedlings (Quercus ilex L. subsp. ballota (Desf.) Samp.) nine years after outplanting. Mulching treatments composed of stones, forest debris, and an untreated control were randomly applied to 180 seedlings (n = 60) in January 2001 at the bed level (1 × 1 m) in an abandoned agricultural field in SE Spain. Survival, growth measured by means of leaf area, and nutrient concentrations in leaves and soil were measured. Both mulches provided higher survival and greater leaf‐area growth than the control, but did not differ in leaf‐nutrient concentration. Most of the analysed soil variables were not affected by the mulching treatments at the end of the study period, and, therefore, the soil properties changes by mulching might be slower than expected under semi‐arid conditions. Copyright © 2013 John Wiley & Sons, Ltd.