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141.
Michael H. Woodford 《Tropical animal health and production》2009,41(7):1023-1033
Proliferation of disease pathogens capable of affecting humans, domestic livestock and wildlife increasingly threatens environmental
security and biodiversity. Livestock and wild animals in proximity to human beings are often in the chain of transmission
and infection. Globalization of industrial livestock production (especially poultry upon which so much of the burgeoning human
population depends) often permits transcontinental disease spread. Rapidly expanding (and often illegal) international trade
in wild and domestic animals and their products are increasingly involved in the emergence of new diseases that may have the
ability to transmit among humans, livestock and wildlife. Rapidly increasing urbanization has led in many places to overcrowded
townships that rely on “bushmeat” for sustenance and has contributed to the emergence of virulent zoonotic pathogens. The
emergence and proliferation of pathogens are exacerbated by anthropogenic transformation of natural landscapes in order to
increase agricultural and livestock production. This paper posits that data gathered by veterinary ecologists should be interpreted
and used by other disciplines. The importance of a thorough knowledge of the “natural history” (ecology) of the disease agent
and its human, domestic and wild hosts is stressed. 相似文献
142.
Kuroishi T Komine K Kai K Itagaki M Kobayashi J Ohta M Kamata S Kumagai K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2003,65(8):899-906
To investigate the pathological role of staphylococcal enterotoxins (SEs) and toxic shock syndrome toxin-1 (TSST-1) in bovine mastitis, the production of SEs and TSST-1 was investigated in staphylococci isolated from 120 mammary gland secretions (MGS, 51 from no clinical sign-mammary glands and 69 from staphylococcal mastitic-mammary glands) collected from dairy farms where staphylococcal mastitis frequently occurred in Miyagi and Yamagata prefectures from 1997 to 1998. Concentrations of these toxins and specific antibody titers in each MGS were also measured. Furthermore, SEC and TSST-1 were inoculated into lactating mammary glands and inflammatory responses were analyzed. A high percentage of staphylococci including Staphylococcus aureus and coagulase-negative staphylococci isolated from both no clinical sign- and mastitic-MGS produced both SEC and/or TSST-1. The concentration of SEC increased with the severity of the mastitis, and was significantly higher (P<0.05) in acute mastitic-than in no clinical signs-MGS. Titers of specific antibodies to TSST-1 in MGS were significantly higher (P<0.05) than those to SEC, regardless of whether or not the cows were lactating or mastitic. Specific antibodies purified from MGS neutralized each toxin in vitro. A significant increase (P < 0.05) in somatic cell counts was induced by the intramammary inoculation of SEC but not TSST-1. These findings indicated that SEC rather than TSST-1 plays an important role in the pathology of staphylococcal bovine mastitis. The inflammatory activity of TSST-1 was probably neutralized by specific antibodies in MGS. 相似文献
143.
Research in control of tick-borne diseases and trypanosomosis, and their vectors, namely, ticks and tsetse flies respectively,
has been on going for decades. However, very little attention has been paid to the socio-economic factors that are likely
to influence the outcome of the interventions in the control of these diseases. Thus, this study was designed to investigate
these factors, mainly the intra-household factors influencing decision-making in the control of Vector-borne diseases in the
pastoralist areas of Uganda. These factors included: indigenous technical knowledge, household economic factors, and gender.
Both qualitative and quantitative methods were used in the collection and analysis of data. The tools used for data collection
included among others, participatory learning and action (PLA), and Case studies. The findings included the following: In
pastoralist households, a big proportion of the household budget was allocated to vector-borne diseases control. In the male-headed
households, men dominated decision-making on vector-borne diseases control, although the goals and priorities of men and women
in these households were not the same. Also, vector-borne disease control was predominantly by use of modern veterinary drugs,
and pastoralists treated sick cattle by themselves even in situations where there were veterinary personnel. 相似文献
144.
Charles Adarkwah Daniel Obeng-Ofori Cornel Adler Carmen Büttner Christoph Reichmuth Matthias Schöller 《Phytoparasitica》2011,39(3):223-233
The compatibility and protectant potential of Calneem® oil derived from the neem tree Azadirachta indica and two parasitoids, Habrobracon hebetor and Venturia canescens, for the control of the rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) and the tropical warehouse moth Cadra cautella Walker (Lepidoptera: Pyralidae) in stored rice and wheat, were evaluated in the laboratory. Calneem® oil (= neem oil) is a biopesticide produced, registered and marketed in Ghana by AQUA AGRIC Community Projects (AACP/Caldor Ghana Ltd., Tema). It contains 0.3% azadirachtin as its major active ingredient. The oil was emulsified with water using 0.07% soap. Fourth instar moth larvae were held in grain treated with neem oil only, grain treated with one of the parasitoids only, grain treated with a combination of neem and one of the parasitoids, and a control with untreated grain. Neem oil was applied at concentrations from 5,000 to 30,000 ppm. All samples were kept in growth cabinets maintained at 25°C and 65–70% r.h. Adult emergence was recorded after 4 weeks. Parasitoid or neem treatments alone reduced the emergence of C. cephalonica and C. cautella. In general, parasitoid releases were as effective as a combination of neem oil and parasitoids. At the lowest dose, 5,000 ppm, the combination of neem and parasitoid was more effective than the neem alone. The number of adults of H. hebetor and V. canescens that emerged in rice containing either parasitoids alone or in combination with neem oil was similar. This indicates minimal or no adverse effect of neem oil on the two parasitoids. It is thus possible to incorporate neem oil in a well-designed pest management program with parasitoids. 相似文献
145.
Kuko Fuke Kana Takeshita Nanako Aoki Toshiyuki Fukuhara Mayumi Egusa Motoichiro Kodama Hiromitsu Moriyama 《Journal of General Plant Pathology》2011,77(4):248-252
Strains of the Japanese pear pathotype of Alternaria alternata were screened for double-stranded RNAs (dsRNAs). Four strains had several dsRNAs; strain N18 was associated with several
dsRNAs and had impaired growth phenotypes such as irregular mycelium and abnormal pigmentation. We isolated dsRNA-cured isolates
from strain N18 by single-conidium isolation. The dsRNA-cured isolates had recovered normal growth and pigmentation. Enlarged
vesicles were observed in mycelial cells of the original dsRNA-carrying N18 strain. DAPI nuclear staining revealed regression
of the nuclei in dsRNA-carrying N18 cells. These results indicate that the dsRNAs might have negative effects, such as apoptosis-like
cell death, on the host fungus. 相似文献
146.
147.
Junia Vianna Corrêa da Silva Fernando César Juliatti João Renato Vaz da Silva Fernanda Carvalho Barros 《European journal of plant pathology / European Foundation for Plant Pathology》2011,131(3):409-418
Soybean rust is caused by an obligate parasite (Phakopsora pachyrhizi) which has spread in Brazil in each new season since 2001 and, despite the efforts to control the disease, losses have occurred
every year. Its control demands several tactics amongst which chemical control with fungicides is the main method and remains
indispensable. Control strategies such as the use of cultivars with partial resistance are desirable, but are not yet commercially
available. The present study analyzed the existing differences in the reactions of short, medium and long cycle soybean cultivars
against Asian rust and their responses to fungicide sprays. The experiment was conducted at Uberlandia-MG, Brazil, under field
conditions from December 2007 to May 2008, in the Syngenta Seeds Experimental Station. The high pressure of the disease in
the experiment simulated the natural pressure that the disease often reaches in Brazil. The studied variables were: visual
severity (percentage of infected leaf area), percentage defoliation and productivity (kg ha−1). Disease severity was expressed as AUDPC (area under disease progress curve). Variance analysis and comparison of means
by the Tukey test (5% significance) were done for all variables studied. Significant differences were observed between cultivar
effects and chemical control programs. The results obtained here indicate that the cultivars M-Soy 8199RR and Emgopa 315RR
were less susceptible to disease, and that a control program termed “monitoring” (in which the appearance of new pustules
of the pathogen were monitored to make the decision at each fungicide spray) was the most effective. 相似文献
148.
Yong Zhang Yu Chen Xiaofeng Zhu Ying Xu Yiping Hou Tongchun Gao Mingguo Zhou 《Phytoparasitica》2011,39(4):393-401
Xanthomonas oryzae pv. oryzicola, the causal agent of rice leaf streak disease, was found to be sensitive to streptomycin (an aminocyclitol glycoside antibiotic),
by inhibition of protein synthesis resulting from interference with translational proofreading. This study aimed to determine
the molecular resistance mechanism of X. oryzae pv. oryzicola to streptomycin. Seven streptomycin-resistant mutants were obtained by UV induction or streptomycin selection. These mutants
can grow at 100 μg ml−1 of streptomycin while the wild-type strain (RS105) cannot grow at 5 μg ml−1. Sequencing indicated that the rpsL gene encoding ribosomal protein S12 has 375 bp encoding 125 amino acid residues. In all resistant strains, a mutation in
which AAG was substituted for AGG (Lys→Arg) occurred either at codon 43 or 88. Two plasmids, pUFRRS and pUFRRX, were constructed
by ligating the rpsL gene into the cosmid pUFR034. The plasmids pUFRRS and pUFRRX containing the Lys→Arg mutation of the rpsL gene conferred streptomycin resistance to the sensitive wild-type strain by electroporation. Both transformants, RS1 and
RS2, could grow in the medium containing 50 μg ml−1 of streptomycin. A mutation at codon 43 or 88 in rpsL can result in resistance of Xanthomonas oryzae pv. oryzicola to streptomycin. 相似文献
149.
Plants defend themselves against microbial invasions by detecting conserved molecules, collectively called pathogen-associated
molecular patterns (PAMPs). PAMPs-triggered basal resistance is the first inducible layer of plant defense. Here we found
that Ralstonia solanacearum strain RS1002 can efficiently grow and cause disease in ecotype Columbia-0 of the model plant Arabidopsis thaliana in a manner dependent on the Hrp type III secretion system (T3SS). The extent of disease symptoms caused by R. solanacearum was reduced in plants pretreated with ΔhrpY mutant deficient in the functional Hrp T3SS. Pretreatment with a boiled extract (BE) from R. solanacearum had a similar inhibitory effect on disease development or bacterial multiplication in both Arabidopsis and several solanaceous plants. Simultaneous inoculations with BE and R. solanacearum did not induce BE-mediated resistance, nor did a BE treatment with proteinases. These results indicate that host plants recognize
an unknown proteinaceous PAMP in the BE to induce disease resistance and that the Hrp T3SS of R. solanacearum can suppress it. From an analysis using Arabidopsis mutants lacking PAMP receptors, the elongation factor Tu of R. solanacearum was shown to partially contribute to BE-mediated basal resistance in Arabidopsis plants. 相似文献
150.
Ezenduka EV Oboegbulem SI Nwanta JA Onunkwo JI 《Tropical animal health and production》2011,43(3):557-559
The use of antimicrobial agents in poultry production results in their accumulation in the body tissues and products such
as milk and egg. The subsequent accumulation of these drugs and their metabolites in body cells is known as drug residue.
This study was designed to determine the prevalence of antimicrobial residues in eggs from poultry farms and retail outlets
in Enugu State, Nigeria. Eggs from 25 selected commercial farms and ten retail outlets were screened for the prevalence of
antimicrobial residue. Also, structured questionnaires were administered to 25 commercial farms in the state to determine
the management practices and the most widely used antimicrobial drugs in farms and possible association between the management
practices and the occurrence of antimicrobial residues in eggs from these farms. All the 25 farms surveyed use oxytetracycline.
Eggs from nine of the surveyed farms tested positive for antimicrobial residue and three of the ten surveyed farms also tested
positive for antimicrobial residue. No association was observed (p 0.05; Fisher’s exact test) between the occurrence of antibiotic residues in eggs and farm size, feed source and housing systems.
This study was able to demonstrate the presence of antimicrobial residues in eggs destined for human consumption. Drugs like
nitrofurans which has been banned for use in food animals are still very much in use in Enugu State, Nigeria. Antibiotics
given as feed additives may give rise to drug residues in food animals. 相似文献