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1.
Lounis Mohamed Zhao Ge Li Yuehua Gao Yubin Kaidi Rachid Oumouna Mustapha Wang Junwei Oumouna Karine 《Tropical animal health and production》2018,50(3):547-553
Avian pathogenic E. coli (APEC) is the etiologic agent of avian colibacillosis, the most common disease responsible for chicken morbidity in the world. Although multiple virulence-associated factors were identified, their prevalence in Algeria is still poorly known. In the present research, 92 avian pathogenic E. coli (APEC) isolates were recovered from broilers with clinical signs and lesions of colibacillosis. In addition, 32 E. coli isolates collected from feces of healthy birds (AFEC) were included for comparison. All isolates were investigated by PCR for the presence of a total of 11 virulence-associated genes described for avian pathogenic (iroN, ompT, hlyF, iss, iutA, and fimC) and diarrheagenic E. coli (eae, stx, elt/est, ipaH, and aggR). The sensitivity of 39 APEC isolates to 16 antibiotics was also determined using antimicrobial pretreated microplates. Here, we report that 98% of the examined isolates host at least one of the tested virulence factors. The most prevalent genes in APEC were iutA (90.6%), ompT (86.9%), and iss (85.8%); whereas, iutA (78.1%), fimC (78.1%), and iroN (68.7%) were the highest prevalent genes in AFEC. Our data showed that none of the AFEC isolates harbor any of the tested diarrheagenic genes. Moreover, only elt/est (5.4%), stx (2.1%), and ipaH (2.1%) genes were carried by APEC isolates. We further established that ceftazodime, ceftiofur, mequindox, amoxicillin/clavulanic acid, and meropenem were the most efficient antibiotics against the analyzed APEC isolates. Overall, our findings provide more insights about APEC and AFEC virulence potential in Algeria which could participate in the fight against colibacillosis. 相似文献
2.
Catherine Grondeau Alexandre Mabiala Rachid Ait-Oumeziane Régine Samson 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(4):353-363
Pseudomonas syringae pv.pisi, pea bacterial blight agent, is seed-transmitted. Some aspects of its life cycle and its biology were investigated. The colonization of pea plants obtained from naturally infected seeds was studied in natural conditions while high populations of bacteria developed on plants showing no symptoms. Two streptomycin-resistant mutants were used to study the epiphytic life of the pathogen. Populations were monitored in different host-parasite compatibilities. When race 2 or race 6 of the pathogen was surface-inoculated on susceptible cultivars, a decrease of population size was observed during the following one to three days but was followed by an increase to levels 1000 times greater than the initial number detected, without symptoms for most of the plants. When race 2 was surface-inoculated on resistant genotypes or race 6 on non-host plants, bacteria did not multiply but population levels slightly decreased.Pseudomonas syringae pv.pisi shows a resident phase and its development is race-specific. Weeds collected in naturally contaminated pea fields, diseased or not, often harboured the pathogen but with levels smaller than those observed on peas. Pea crop debris and volunteers kept high levels of bacteria for at least eight months after the harvest of a diseased crop. As long as two pea crops are not grown one after the other in the same field, it is unlikely that debris and volunteers will act as an important inoculum source. The development of this pathogen during the growing season is considered as an important parameter to take into account for controlling the disease through seed health testing. 相似文献
3.
N.M. Ocarino DVM MS A.E. Silva DVM MS S.A. Frana DVM M.A. Rachid DVM PhD E.F. Nascimento DVM PhD M.S. Palhares DVM PhD V.A. Gheller DVM PhD R. Serakides DVM PhD 《Journal of Equine Veterinary Science》2006,26(4):168-170
A case of renal tubular carcinoma with bone metaplasia is reported in a 20-year-old male, mixed breed horse having a history of weight loss and hematuria. This report includes the clinical signs, macroscopic and microscopic lesions, and the immunohistochemical findings of this neoplasm. 相似文献
4.
L. Krishnamurthy Rachid Serraj C. Tom Hash Abdullah J. Dakheel Belum V. S. Reddy 《Euphytica》2007,156(1-2):15-24
Genetic improvement of salt tolerance is of high importance due to the extent and the constant increase in salt affected areas.
Sorghum [Sorghum bicolor (L.) Moench] has been considered relatively more salt tolerant than maize and has the potential as a grain and fodder crop
for salt affected areas. One hundred sorghum genotypes were screened for salinity tolerance in pots containing Alfisol and
initially irrigated with a 250-mM NaCl solution in a randomized block design with three replications. Subsequently 46 selected
genotypes were assessed in a second trial to confirm their responses to salinity. Substantial variation in shoot biomass ratio
was identified among the genotypes. The performance of genotypes was consistent across experiments. Seven salinity tolerant
and ten salinity sensitive genotypes are reported. Relative shoot lengths of seedlings were genetically correlated to the
shoot biomass ratios at all stages of sampling though the relationships were not close enough to use the trait as a selection
criterion. In general, the whole-plant tolerance to salinity resulted in reduced shoot Na+ concentration. The K+/Na+ and Ca2+/Na+ ratios were also positively related to tolerance but with a lesser r
2. Therefore, it is concluded that genotypic diversity exists for salt tolerance biomass production and that Na+ exclusion from the shoot may be a major mechanism involved in that tolerance. 相似文献
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Methods for spatial cluster detection dealing with diseases quantified by continuous variables are few, whereas several diseases are better approached by continuous indicators. For example, subclinical mastitis of the dairy cow is evaluated using a continuous marker of udder inflammation, the somatic cell score (SCS). Consequently, this study proposed to analyze spatialized risk and cluster components of herd SCS through a new method based on a spatial hazard model. The dataset included annual SCS for 34 142 French dairy herds for the year 2000, and important SCS risk factors: mean parity, percentage of winter and spring calvings, and herd size. The model allowed the simultaneous estimation of the effects of known risk factors and of potential spatial clusters on SCS, and the mapping of the estimated clusters and their range. Mean parity and winter and spring calvings were significantly associated with subclinical mastitis risk. The model with the presence of 3 clusters was highly significant, and the 3 clusters were attractive, i.e. closeness to cluster center increased the occurrence of high SCS. The three localizations were the following: close to the city of Troyes in the northeast of France; around the city of Limoges in the center-west; and in the southwest close to the city of Tarbes. The semi-parametric method based on spatial hazard modeling applies to continuous variables, and takes account of both risk factors and potential heterogeneity of the background population. This tool allows a quantitative detection but assumes a spatially specified form for clusters. 相似文献
7.
Bel-Rhlid R Talmon JP Fay LB Juillerat MA 《Journal of agricultural and food chemistry》2004,52(20):6165-6169
A novel enzymatic dehalogenating activity of 3-chloro-1,2-propanediol (3-MCPD) with Saccharomyces cerevisiae (baker's yeast) is reported. All bioconversion assays were carried out under aerobic conditions, at 28 degrees C, and the kinetics were monitored. The biodegradation was performed at different pH values (6.2, 7.0, and 8.2), in the presence and absence of glucose, using racemic 3-MCPD at two different concentrations (7.3 micromol/L and 27 mmol/L). Optimal conversion (68%) of racemic (R,S)-3-MCPD at a concentration of 27 mmol/L was achieved after 48 h of reaction time, at pH 8.2, and in the presence of glucose. At a concentration of 7.3 micromol/L, 73% degradation was observed after 72 h, at pH 8.2 and in the absence of glucose. Under the same experimental conditions, the conversion of pure (S)-3-MCPD (85%) was higher than that of the (R)-enantiomer (60%). 相似文献
8.
Neospora caninum is a parasite responsible for paresis in dogs. The dog can harbour enkysted parasites in several organs. The detection of N. caninum was performed using 3 different real time PCR systems all amplifying the NC5 DNA region. One system was based on Sybrgreen, one on Plexor technology and the last on Taqman probe. Comparison of the three methods indicated that the detection limit was 1 equivalent genome on pure DNA but that this detection limit increased in the presence of foreign DNA using the Sybrgreen and Plexor systems. Therefore, the Taqman system was chosen to detect N. caninum in liver and spleen of naturally infected dogs. The overall prevalence was 32.2%. Comparison between PCR results and serological results using IFAT showed that among the 28 PCR positive dogs only 9 were seropositive and that 8 seropositive dogs were PCR negative. Therefore serology can underestimate the real carriage in dogs. However, PCR methods must be improved in terms of sensitivity and inhibition problems. 相似文献
9.
Moulay Chrif Smaili Lahcen El Ghadraoui Fatima Gaboun Rachid Benkirane Abdelali Blenzar 《Phytoparasitica》2014,42(3):421-436
Aphid control in Moroccan citrus orchards is based mainly on carbamate and neonicotinoid sprays, especially methomyl and imidacloprid. The extensive use of these insecticides may have side effects on natural enemies and environment quality and raises human health concerns. This research aimed to assess the control of aphids with insecticidal soap, kaolin and augmentative biological control using the indigenous predator Adalia decempunctata L. (Coleoptera: Coccinellidae). The insecticides were applied and the predators were released in April 2009 and 2010. Under field experimentation, the methomyl and imidacloprid foliar pulverization were very effective against aphids. In contrast, the insecticidal soap and kaolin application were less efficient while A. decempunctata adults were effective only in the first week after release. The side effects on beneficial insects were also assessed and discussed. The possibility of employing A. decempunctata in an integrated pest management package in citrus groves is discussed in relation to effectiveness and side effects on beneficial arthropods. 相似文献
10.
Karima Bouhafa Lhoussaine Moughli Rachid Bouabid Ahmed Douaik Youness Taarabt 《Journal of plant nutrition》2018,41(8):956-968
The study aims to track the dynamics of the olive leaf nitrogen (N), phosphorus (P) and potassium (K) for five olive varieties under drip irrigation in farmer's fields in central Morocco. Leaf sampling was done every month from May 2014 to April 2015. Leaf macronutrients contents showed variation over time. Olive leaves have maintained the same N content throughout the study period indicating a continuing olive uptake of nitrogen. Higher leaf P absorption was observed during flowering and fruit magnification periods indicating the important P needs of olive during these periods. Olive leaf K levels were higher from September to December indicating the high K needs of olive. No variety effect was revealed on the leaf N, P and K contents. Very highly significant differences were found between the leaf N and K levels measured at different sampling periods. The leaf P concentration was statistically equal in all measuring periods. 相似文献