The use of pulsed-field gel electrophoresis to investigate the epidemiology of Mycoplasma bovis in French calf feedlots

Mycoplasma bovis is a major cause of respiratory outbreaks in cattle feedlots. In this study pulsed-field gel electrophoresis (PFGE) was used to trace field strains and provide information on M. bovis patterns of spread in calf feedlots. The suitability of KpnI, MluI and SmaI restriction enzymes was assessed on different sets of strains. The discriminative power of the first two enzymes was first assessed using 28 epidemiologically unrelated strains; stability was 100% on multiple isolates from in vivo experimental infection. Thirty-nine field isolates from six feedlots were then evaluated. In contrast to the unique fingerprints displayed by the unrelated strains, the isolates from the feedlots showed identical patterns at the time of the outbreak of respiratory disease and 4 weeks later. The PFGE typing results suggest that M. bovis strains follow a clonal epidemic spread pattern at the herd level and that the same strain persists in calves of the herd after the clinical signs have disappeared.     

Effect of canopy gap size and ecological factors on species diversity and beech seedlings in managed beech stands in Hyrcanian forests

We studied the species diversity of the herb layer and ecological factors in harvest-created gaps in beech stands under a single-tree selection system in Northern Iran. To determine diversity, the number of beech seedlings, and other ecological factors, 16 gaps were selected and subplots of 5 m2 were positioned at the centre and at the cardinal points of each gap. Species richness and Simpson diversity index increased with increasing gap area as did numbers of seedlings. With increasing humus layer thickness, species richness declined but the Hill evenness index increased. Species richness increased with increasing light availability. There was no relationship between crown radii of beech trees and diversity indices. Correlations between environmental factors and numbers ofindividuals of some species in the herb layer were not significant except in a few cases. The results help explain the effects of man-made gaps on the dynamics of managed beech stands and this benefits evaluation of silvicultural operating plans.     

Comparison of conventional and non-conventional techniques for the diagnosis of bovine brucellosis in Sudan

The objective of the present study was to detect brucellosis in suspected dairy cattle in Khartoum State, Sudan using the conventional serological tests and tests done on milk in comparison to a PCR-based technique. Milk and blood samples collected simultaneously from suspected brucellosis cows (n = 147) in 12 different dairy farms around Khartoum State were used in the study. Overall, 54 (36.7%) of the total milk samples were positive according to the milk ring test (MRT), while 29 (19.7%) of the serum samples were positive according to the Rose Bengal test (RBT); microscopy on modified Ziehl-Neelsen-stained slides detected 13.6% of the cases, and recovery of Brucella species on both Brucella medium and tryptic soya agar was 7.5%. Thirty-three (22.4%) samples were found positive on PCR-amplified IS711 which were then taken as positive brucellosis cases. The differences of RBT and PCR-IS711 from MRT were highly significant (P < 0.05). MRT detected more cases of bovine brucellosis compared to RBT, PCR, microscopy, and culture. MRT is recommended as a noninvasive test compared to RBT, and it is less expensive compared to PCR and culture.     

Sequence and phylogenetic analysis of neuraminidase genes of H9N2 avian influenza viruses isolated from commercial broiler chicken in Iran (2008 and 2009)

A total of 512 tissue samples collected from 30 farms located in various states of Iran during 2008–2009 as part of a program to monitor avian influenza viruses (AIVs) infection in Iran’s poultry population. To determine the genetic relationship of Iranian viruses, neuraminidase (NA) genes from ten isolates of H9N2 viruses isolated from commercial chickens in Iran during 2008–2009 were amplified and sequenced. The viruses’ neuraminidase gene was >90% similar to those of A/Quail/Hong Kong/G1/97 (H9N2) sublineage. The neuraminidase stalk regions in these Viruses had no deletion as compared to that of chicken/Beijing/1/94 sublineage (Beijing-like viruses) and the two human isolates A/HK/1073/99, A/HK/1074/99. Phylogenetic analysis of neuraminidase (NA) gene showed that it shares a common ancestor A/Quail/Hong Kong/G1/97 isolate which had contributed the internal genes of the H5N1 virus. The results of this study indicated that No (Beijing-like) virus and (Korean-like) virus were found in chickens in Iran, and the NA genes of H9N2 influenza viruses circulating in Iran during the past years were well conserved and the earlier Iranian isolates may be considered to represent such a progenitor.     

Anti-acetylcholinesterase, anti-α-glucosidase, anti-leishmanial and anti-fungal activities of chemical constituents of Beilschmiedia species

Phytochemical investigation of Beilschmiedia alloiophylla has resulted in the isolation of one new alkaloid, 2-hydroxy-9-methoxyaporphine (1), and ten known natural products, laurotetanine (2), liriodenine (3), boldine (4), secoboldine (5), isoboldine (6), asimilobine (7), oreobeiline (8), 6-epioreobeiline (9), β-amyrone (10), and (S)-3-methoxynordomesticine (11). Chemical studies on the bark of B. kunstleri afforded compounds 2 and 4 along with one bisbenzylisoquinoline alkaloid, N-dimethylphyllocryptine (12). Structures of compounds 1-12 were elucidated on the basis of spectroscopic methods. All of these isolates were evaluated for their anti-acetylcholinesterase (AChE), anti-α-glucosidase, anti-leishmanial and anti-fungal activities. Compounds 1-12 exhibited strong to moderate bioactivities in aforementioned bioassays.     

Effects of spirulina powder (Spirulina platensis) as a dietary additive on Oscar fish,Astronotus ocellatus: Assessing growth performance,body composition,digestive enzyme activity,immune‐biochemical parameters,blood indices and total pigmentation

In this study, the effect of spirulina meal (Spirulina platensis) as a feed additive on growth and physiological response of Oscar fish,Astronotus ocellatus, was assessed using four diets including control without spirulina supplementation, 13.75 g/kg spirulina (SP1), 27.50 g/kg spirulina (SP2) and 55 g/kg spirulina (SP3). One hundred and twenty fish (10.41 ± 0.25 g) were disturbed to twelve aquariums and fed to apparent satiation three times a day for 8 weeks. The result showed that the SP3 treatment had statistically better growth performance, feeding parameters, total protease activity, total protein and lipid contents than the control. Moreover, haemoglobin, haematocrit, mean erythrocyte haemoglobin and mean erythrocyte haemoglobin concentrations were improved considerably in the SP3 treatment compared with the control. The SP3 treatment showed higher total protein and albumin levels, but lower triglycerides, cholesterol levels and liver enzyme activities than the control. Also, serum complements (C3, C4), lysozyme activity and total carotenoid contents in fish skin significantly increased in the SP3 treatment compared with the control. The results of this study suggest that spirulina powder at the level of 55 g/kg of the diet can be used as a functional natural feed additive to improve the performance of Oscar fish.     

Water intake of laying hens after exposure to a warm climate

1. The water intake of laying hens was measured after exposure for 4 h to an ambient temperature (TA) of 35 or 40 degrees C. 2. Water intake increased continuously over 1 h but did not exceed a mean value of 80% of water lost by evaporation. There was considerable variation between birds.     

The effect of Rosa damascena essential oil on the amygdala electrical kindling seizures in rat

We investigated the effect of Rosa damascena Mill, essential oil on the development of induced amygdala kindling seizures. Male Wistar rats were implanted with one tripolar and two monopolar electrodes in right basolateral amygdala and dura surface, respectively. The control group was injected solvent of essential oil and two experimental groups were injected 750 and 1000 mg kg(-1) of essential oil (ip), 30 min before a daily kindling stimulation. The number of stimulations required for the first appearance of seizure stages was significantly larger in two experimental groups than in control group. Mean after discharge duration was significantly different and essential oil reduced the increase of after discharge duration. Mean after discharge amplitude was also shorter in the groups treated with essential oil than in control group. Duration time for 5th stage of seizure at fully-kindled rats was significantly shorter in two experimental groups than control group. These results suggest that Rosa damascena essential oil significantly retarded the development of seizure stages and possesses the ability to counteract kindling acquisition. The flavonoids of Rosa damascena may act via GABAA receptors as previous studies have proposed for flavonoids of other medicinal plants. More detailed studies are recommended to define the effective component(s) of Rosa on different types of epilepsy.     

Variation for stomatal characteristics and water use efficiency among diploid,tetraploid and hexaploid Iranian wheat landraces

Wheat is one of the most important crops in the world. Its study has involved anatomy, ecology, physiology, molecular biology, biotechnology, and cultivation. Knowledge of the relationship of diploid, tetraploid and hexaploid wheat with stomatal characteristics and water-use efficiency is spare and is subject to argument. The present study was aimed to examine different characteristics of stomata in 28 Iranian landraces belonging to the species Triticum monococcum (2n = 2x = 14), Triticum durum (2n = 4x = 28) and Triticum aestivum (2n = 6x = 42), respectively and investigated a possible relationship between these characteristics and water use efficiency by pot cultivation experiments. The results revealed large variation among landraces as well as between the different species for stomatal frequency and size. The diploid wheat species had the highest stomatal frequency and the lowest stomatal length and width. The hexaploid species had a lower stomatal frequency than the tetraploid species. A highly significant relationship was noted between the value of those traits on the adaxial and abaxial surfaces of the leaf. The ratio of adaxial to abaxial values appeared to be constant for a given species. Both stomatal frequency and size were associated with ploidy level, but also with the nature of the constituting genomes of the species. A highly significant negative association was found among accessions between stomatal frequency and size. As a consequence, the variation for stomatal area per unit leaf area was less than for the other traits. Diploid and hexaploid wheat have significantly higher water use efficiency, compared to tetraploid wheat. No clear association was found, however, between water use efficiency and stomatal characteristics.