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71.
AIM: To describe the Chlamydia psittaci genotypes in samples from native and introduced birds from New Zealand by analysis of the sequence variation of the ompA gene.

METHODS: DNA was extracted from samples collected from a non-random sample of birds; either swabs from live asymptomatic birds or birds with clinical signs, or formalin-fixed, paraffin-embedded (FFPE) samples from historical post-mortem cases. The presence of C. psittaci in all samples had been confirmed using a quantitative PCR assay. The C. psittaci ompA gene was amplified and sequenced from samples from 26 native and introduced infected birds comprising 12 different species. These sequences were compared to published available C. psittaci genotypes.

RESULTS: Genotypes A and C of C. psittaci were identified in the samples. Genotype A was identified in samples from nine birds, including various native and introduced species. Genotype C was identified in samples from 16 different waterfowl species, and a mixed infection of both genotypes was found in a kaka (Nestor meridionalis). In native birds, C. psittaci infection was confirmed in seven new host species.

CONCLUSIONS AND CLINICAL RELEVANCE: Two genotypes (A and C) of C. psittaci were found in samples from a wider range of both native and introduced species of birds in New Zealand than previously reported. Both genotypes have been globally associated with significant disease in birds and humans. These initial results suggest the host range of C. psittaci in New Zealand birds is under-reported. However, the prevalence of C. psittaci infection in New Zealand, and the associated impact on avian and public health, remains to be determined. There are biosecurity implications associated with the importation of birds to New Zealand if there is a limited diversity of C. psittaci genotypes present.  相似文献   
72.
A 13‐year‐old Romanov sheep presented for evaluation of vaginal discharge, depression and anorexia. Blood work demonstrated mature neutrophilia and marked hyperlactatemia. Transrectal and transabdominal ultrasound revealed echogenic fluid (pus) within the uterus. Purulent uterine fluid culture yield Escherichia coli. A diagnosis of pyometra was made. After medical treatment without clinical improvement, an exploratory laparotomy was performed, and a 360‐degree uterine left horn torsion was identified with the pyometra and multiple corpora lutea on both ovaries. Ovariohysterectomy was performed and the ewe recovered uneventfully.  相似文献   
73.
To evaluate non-chemical strategies to control pasture-borne parasites in first-season grazing (FSG) cattle, a 3-year grazing trial was conducted during 2002-2004 on naturally infected pastures on a commercial beef cattle farm in Sweden. A uniform pasture was divided in 4 equal 2 ha paddocks onto each of which 10, 5-9 months old dairy breed steer calves were allocated at turn-out in May each year. Two strategies were evaluated: (1) turn-out onto pasture which had been grazed the previous year by second-season grazing (SSG) steers, followed by a move to aftermath in mid-July (RT) and (2) supplementation with concentrate and roughage for 4 weeks from turn-out (FD). Comparisons were made with an untreated (UT), and an anthelmintic treated control group (DO). Animal parasitology and performance were monitored monthly throughout the 20 weeks grazing period. Additional sampling occasions were performed on day 9 (for coccidia) and 10 weeks after turn-out (mid-July). Due to clinical parasitic gastro-enteritis (PGE), salvage treatments were performed on all animals in group FD approximately 7 weeks after turn-out in 2003 and of three animals in group UT 5 weeks after turn-out in 2004. In 2003, the geometric mean oocyst excretion 9 days after turn-out was approximately 150,000 opg of mainly Eimeria alabamensis in group FD, and in 2004 approximately 180,000 opg in group UT. Apart from the DO group, geometric mean faecal egg counts (FEC) were between 80 and 400 epg 4 weeks after turn-out. Mean serum pepsinogen concentrations (SPC) of approximately 3.6 U tyrosine were recorded in the FD and UT groups from late August 2002. In 2003 and 2004, mean concentrations in these groups were between 4.1 and 7.2 U tyrosine 8 weeks after turn-out. By the end of the three grazing seasons the average weight gain difference compared to the DO group was for FD -29, -38 and -5 kg and for RT -4, -21 and +14 kg, and compared to the UT group -18, +2 and +22 for FD and +7, +19 and +41 kg for group RT. In conclusion, the rotation control strategy showed promising results, whereas the strategic feeding was poor from a parasite control standpoint.  相似文献   
74.
The anthelmintic resistance status was investigated of nematode parasites of sheep and goats owned by smallholder farmers in communities that received breeding stock from a source where a high level of anthelmintic resistance has been reported. The investigation used the faecal egg count reduction technique, whereby suitable animals within each of eight separate communities were pooled to achieve the numbers required to conduct separate tests for both sheep and goats. Anthelmintics tested were albendazole (ABZ), tetramisole (TET), a combination (ABZ $+$ TET) and ivermectin (IVM), at the manufacturers' recommended dose rates. Results showed that there was no evidence of anthelmintic resistance in nematode parasites of either sheep an goats in any community. This indicates that dilution of resistant parasites imported with introduced breeding stock, and the low selection pressure imposed by the smallholder farmers themselves, has prevented anthelmintic resistance from emerging in nematode parasites of small ruminants in these communities.  相似文献   
75.
Faecal egg count reduction tests (FECRT) were conducted in May 2003 to determine the efficacy of anthelmintics used for treatment against nematode parasites in separately managed sheep and goat flocks at Alemaya University in eastern Ethiopia. These tests revealed high levels of anthelmintic resistance to albendazole, tetramisole, the combination of these two drugs, and to ivermectin in the goat flock (predominantly infected by Haemonchus contortus and Trichostrongylus spp.), whereas all drugs were highly efficacious in the sheep flock. A second FECRT confirmed these observations. Following this, a new management system was implemented on the goat flock for a period of 9 months (January-September 2004) in an attempt to restore the anthelmintic efficacy. This involved a combination of measures: eliminating the existing parasite infections in the goats, exclusion from the traditional goat pastures, and introducing communal grazing of the goats with the university sheep flock and livestock owned by neighbouring small-holder farmers. A second series of FECRTs (Tests 3 and 4) conducted 7 months after this change in management, showed high levels of efficacy to all three drugs (albendazole, tetramisole and ivermectin) in the goat flock. This is the first field study to demonstrate that anthelmintic efficacy in the control of nematode parasites of small ruminants can be restored by exploiting refugia.  相似文献   
76.
One hundred and twenty‐six suckled crossbred cows (Bos taurus × Bos indicus), with body condition score ≥3 (1–5 point scale), were employed in the present study to evaluate the effectiveness of intravaginal progestin‐releasing sponges (IVS) for shortening anoestrous interval. Fifty‐four cows were assigned to control group. Seventy‐two cows were treated with IVS impregnated with 250 mg of medroxy‐acetate‐progesterone (MAP) as follows: day 0, IVS plus 5 mg of 17β‐E and 50 mg of MAP i.m.; day 6, 500 IU of equine chorionic gonadotropin and 25 mg prostaglandin F i.m.; day 8, IVS withdrawal and day 9, 1 mg 17β‐E i.m. Cows were also grouped according to postpartum days (dpp) at treatment: MAP <70 days (n = 25); control <70 days (n = 22); MAP >70 days (n = 47); control >70 days (n = 32). From IVS removal, cows were detected in oestrus and inseminated. Cows not detected in oestrus were timed artificial insemination 72 h after sponge removal. Treatment effect on oestrous rate (ER), conception rate (CR), pregnancy rate (PR) and treatment to conception intervals (TCI) and calving to conception intervals (CCI) were evaluated. The ER, CR and PR were analysed using proc logistic , while TCI and CCI with proc glm of SAS. The groups MAP <70 days and MAP >70 days showed higher (p < 0.01) ER than control <70 days and control >70 days (84.0% and 76.6% vs 31.8% and 31.3% respectively). The PR was higher (p < 0.01) in MAP <70 days vs control <70 days (64.0% vs 22.7%) and also higher (p < 0.05) in MAP >70 days vs control <70 days (40.4% vs 18.8%). The TCI and CCI were shorter (p < 0.01) in MAP <70 days vs control <70 days (36.0 and 95.8 days; 95.3 and 158.6 days respectively). In conclusion, only cows treated with IVS before 70 dpp had a CCI shorter than 100 days, consequently this treatment shortened postpartum anoestrous interval in crossbred dual purpose cattle.  相似文献   
77.
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79.
Spatial heterogeneity and long-distance translocation (LDT) play important roles in the spatio-temporal dynamics and management of emerging infectious diseases and invasive species. We assessed the influence of LDT events on the invasive spread of raccoon rabies through Connecticut. We identified several putative LDT events, and developed a network-model to evaluate whether they became new foci for epidemic spread. LDT was fairly common, but many of the LDTs were isolated events that did not spread. Two putative LDT events did appear to become nascent foci that affected the epidemic in surrounding townships.

In evaluating the role of LDT, we simultaneously revisited the problem of spatial heterogeneity. The spread of raccoon rabies is associated with forest cover—rabies moves up to three-times slower through the most heavily forested townships compared with those with less forestation. Forestation also modified the effect of rivers. In the best overall model, rabies did not cross the river separating townships that were heavily forested, and the spread slowed substantially between townships that were lightly forested. Our results suggest that spatial heterogeneity can be used to enhance the effects of rabies control by focusing vaccine bait distribution along rivers in lightly forested areas. LDT events are a concern, but this analysis suggests that at a local scale they can be isolated and managed.  相似文献   

80.
Control of nematode parasites of small ruminants in a wet, tropical environment using the nematophagous fungus, Duddingtonia flagrans, was assessed in this study. Two methods of fungal delivery were tested, namely as a daily feed supplement, or incorporated into feed blocks. Initially, pen trials were conducted with individually penned groups of sheep and goats at dose rates of 125,000 spores and 250,000 spores/kg live weight per day. At the lower dose rate this reduction was between 80 and 90% compared with the pre-treatment levels. At the higher dose rate, there was virtually complete suppression (>99% reduction) of larval recovery. Trials using the fungal feed blocks, showed that when animals were individually penned, they consumed only small amounts of the block (particularly goats), hence little effect on larval recovery in faecal cultures was observed. Grouping animals according to species and dose rate induced satisfactory block consumption and subsequent high levels of larval reduction in faecal cultures. These larval reductions were mirrored by the presence of fungus in faecal cultures. This work was followed by a small paddock trial, whereby three groups of sheep were fed either a feed supplement without fungal spores, supplement with spores, or offered fungal blocks. The dose rate of spores in the latter two groups was 500,000 spores/kg live weight per day. Egg counts were significantly reduced in the two fungal groups, compared with the control group and the latter required two salvage anthelmintic treatments to prevent mortality due to haemonchosis. Pasture larval numbers on the two fungal group plots were also much lower than on the control plot.  相似文献   
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