Prevalence,quantitative load and genetic diversity of Campylobacter spp. in dairy cattle herds in Lithuania

Background

Campylobacteriosis is a zoonotic disease, and animals such as poultry, pigs and cattle may act as reservoirs for Campylobacter spp. Cattle shed Campylobacter spp. into the environment and they can act as a reservoir for human infection directly via contact with cattle or their faeces or indirectly by consumption of contaminated food. The aim of this study was to determine the prevalence, the quantitative load and the genetic strain diversity of Campylobacter spp. in dairy cattle of different age groups.

Results

Faecal samples of 200 dairy cattle from three farms in the central part of Lithuania were collected and examined for Campylobacter. Cattle herds of all three farms were Campylobacter spp. positive, with a prevalence ranging from 75% (farm I), 77.5% (farm II) to 83.3% (farm III). Overall, the highest prevalence was detected in calves (86.5%) and heifers (86.2%). In contrast, the lowest Campylobacter prevalence was detectable in dairy cows (60.6%). C. jejuni, C. coli, C. lari and C. fetus subsp. fetus were identified in faecal samples of dairy cattle. C. upsaliensis was not detectable in any sample. The high counts of Campylobacter spp. were observed in faecal material of dairy cattle (average 4.5 log₁₀ cfu/g). The highest numbers of Campylobacter spp. were found in faecal samples from calves (average 5.3 log₁₀ cfu/g), whereas, faecal samples from cows harboured the lowest number of Campylobacter spp. (average 3.7 log₁₀ cfu/g). Genotyping by flaA PCR-RFLP analysis of selected C. jejuni isolates showed that some genotypes were present in all farms and all age groups. However, farm or age specific genotypes were also identified.

Conclusions

Future studies are needed to investigate risk factors related to the degree of colonisation in cattle. Based on that, possible measures to reduce the colonisation and subsequent shedding of Campylobacter in cattle could be established. It is important to further investigate the epidemiology of Campylobacter in the cattle population in order to assess associated risks to public health.     

Evaluation of alternative pond production systems for raising largemouth bass,Micropterus salmoides

This study evaluated three different pond‐based production systems for raising largemouth bass, Micropterus salmoides, for the food fish market, using nine 0.04‐ha ponds. Treatments included traditional ponds (TP), intensively aerated ponds (IAP), and split‐pond systems (SPS). TP and SPS ponds were aerated at 9.3 kW/ha, while IAP was aerated at 18.6 kW/ha. TP was stocked at 7,500 fish per ha (three replicates per treatment), and the other two production systems (SPS, IAP) were stocked with 12,500 fish per ha. Feed‐habituated advanced fingerlings (128 ± 47.6 g mean individual weight) were cultured for 157 days. Fish were fed a formulated diet (42% protein, 16% lipid) four times a day, feeding with a maximum allowance of 3% of total body weight and readjusted to the initial body weight biweekly. Fish raised in the SPS displayed a significantly lower specific growth rate, lower individual final weight, and lower weight gain, but the biomass gained was significantly higher than TP but not IAP. Final biomass gained was 50% higher in the SPS and IAP than in the TP. Survival rate and feed conversion ratio were not significantly different among treatments and ranged from 71 to 79% and 1.64 to 2.14, respectively.     

甘蔗茎分枝：稀有的形态分离

虽然在甘蔗同节上出现多芽现象已被报道,但是却未曾发现同节多芽能独立生长成蔗茎的现象。文章阐述了2008～2009年度在甘蔗品种CoS 96268宿根蔗大田观察到的一株甘蔗植株上发生的独特的形态分离现象。在该株甘蔗地上部的第7、8节上均有2个芽,但第8节出现溢痕,将该节间分成不等的两部分;该分离部分在第9节间更为明显,并独立生长成两条蔗茎（分枝）,每条蔗茎均具有正常的节间形态。     

Role of interleukin-1β in the regulation of porcine corpora lutea during the late luteal phase of the cycle and during pregnancy

Interleukin-1β (IL-1β) may regulate ovarian physiology. In this study, the influence of IL-1β on secretory activity within the corpora lutea (CL) of cyclic and gravid pigs was determined in vitro during different stages of the CL lifespan, e.g. on Days 10-11, 12-13 and 15-16 of the oestrous cycle and pregnancy. IL-1β (10 ng/ml) increased prostaglandin E2 (PGE2) secretion from CL of the cyclic and gravid pigs during studied days of the oestrous cycle and pregnancy. Increase (P < 0.05) of prostaglandin F2α (PGF2α) in IL-1β-treated CL was demonstrated only on Days 10-11 of the oestrous cycle. More potent stimulatory effect of IL-1β on PGE2 than PGF2α secretion resulted in the enhancement of the PGE2:PGF2α ratio in cyclic and early pregnant CL. IL-1β increased (P < 0.05) progesterone (P4) secretion only in gravid CL and had no effect on oestradiol-17β (E2) release. Expression of cyclooxygenase-2 (COX-2) mRNA was stimulated (P < 0.05) in IL-1β-treated cyclic and gravid CL. Expression of prostaglandin synthase mRNAs in response to IL-1β did not increase. In conclusion, IL-1β modulates PGE2, PGF2α and P4 secretion from porcine CL, depending on luteal stage and the surrounding hormonal milieu. The cytokine may act locally in porcine CL for luteotrophic support throughout the PGE2-mediated synthesis and secretion.     

Bacillus subtilis NRRL B‐30408 inoculation enhances the symbiotic efficiency of Lens esculenta Moench at a Himalayan location

Field‐based experiments were conducted to evaluate the promotion abilities of Bacillus subtilis NRRL B‐30408 for growth of lentil (Lens esculenta Moench) at a mountain location of Indian Himalaya in two consecutive years. Observations were recorded for plant growth, yield, nodulation, root colonization by arbuscular mycorrhizal and endophytic fungi, and other related parameters. A positive influence of bacterial inoculation on plant biomass and yield‐related parameters was recorded in both years. The significant increase in growth and nodule numbers as well as leghaemoglobin and protein concentrations of nodules indicated an enhancement in efficiency of the Rhizobium–legume symbiosis due to bacterial inoculation. An increase in protein concentration was also recorded for shoots, leaves, and seeds. Due to bacterial inoculation, there was an increase in colonization by endophytic fungi and a simultaneous decrease in colonization by arbuscular mycorrhizal fungi in roots. Based on the results of this field study, inoculation with suitable plant growth–promoting rhizobacteria instead of dual inoculation is suggested as a better option for improving the yield and related attributes of a primary dietary legume such as lentil.     

A Test of Positive Association for Detecting Heterogeneity in Capture for Capture–Recapture Data

The Cormack–Jolly–Seber (CJS) model assumes that all marked animals have equal recapture probabilities at each sampling occasion, but heterogeneity in capture often occurs and should be taken into account to avoid biases in parameter estimates. Although diagnostic tests are generally used to detect trap-dependence or transience and assess the overall fit of the model, heterogeneity in capture is not routinely tested for. In order to detect and identify this phenomenon in a CJS framework, we propose a test of positive association between previous and future encounters using Goodman–Kruskal’s gamma. This test is based solely on the raw capture histories and makes no assumption on model structure. The development of the test is motivated by a dataset of Sandwich terns (Thalasseus sandvicensis), and we use the test to formally show that they exhibit heterogeneity in capture. We use simulation to assess the performance of the test in the detection of heterogeneity in capture, compared to existing and corrected diagnostic goodness-of-fit tests, Leslie’s test of equal catchability and Carothers’ extension of the Leslie test. The test of positive association is easy to use and produces good results, demonstrating high power to detect heterogeneity in capture. We recommend using this new test prior to model fitting as the outcome will guide the model-building process and help draw more accurate biological conclusions. Supplementary materials accompanying this paper appear online.     

Characterization of Phytophthora cinnamomi from common walnut in Southern Europe environment

Forty‐eight isolates of Phytophthora cinnamomi obtained from common walnut were analysed according to their variability in growth at different temperatures, virulence, sensitivity to metalaxyl and in genomic DNA. Isolates were obtained from commercial common walnut orchards located in northern Italy and in southern France. Inter‐simple sequence repeat (ISSR) were analysed for the 49 isolates, 43 of which were Italian, 6 French; an isolate of the same species obtained from Viburnum spp. was used as an outgroup. ANOVA on phenotypic characters showed a significant impact of the geographic location of the orchard on isolate variability in terms of reaction to temperatures and aggressiveness. In turn, clustering obtained with UPGMA analysis on genetic data was almost exclusively dependant on isolate variability, nevertheless the 48 isolates seem to share a common variability that differentiates the group from the isolate from Viburnum spp. Correlation between phenotypic and genetic traits was not statistically significant. In conclusion, phenotypic variability like virulence seemed to be conditioned from geographic origin while the genetic variability of P. cinnamomi isolates from walnut was associated to the single genotype.