Turnip mosaic virus pathogenesis and host resistance mechanisms in Brassica

Turnip mosaic virus(TuMV)is a devastating potyvirus pathogen that infects a wide variety of both cultivated and wild Brassicaceae plants.We urgently need more information and understanding of TuMV pathogenesis and the host responses involved in disease development in cruciferous crops.TuMV displays great versatility in viral pathogenesis,especially in its replication and intercellular movement.Moreover,in the coevolutionary arms races between TuMV and its hosts,the virus has evolved to co-opt host factors to facilitate its infection and counter host defense responses.This review mainly focuses on recent advances in understanding the viral factors that contribute to the TuMV infection cycle and the host resistance mechanism in Brassica.Finally,we propose some future research directions on TuMV pathogenesis and control strategies to design durable TuMV-resistant Brassica crops.

Characterization and screening of cotton(Gossypium hirsutum L.)germplasm for leafhopper(Amrasca biguttula biguttula(Ishida))resistance

Background Cotton(Gossypium hirsutum L.)is one of the most significant fibre and cash crops and plays an important role in Indian industrial and agricultural economies.However,over the years quantity and quality have been hampered by the pest leafhopper.Leafhopper alone has been shown to cause yield losses of up to 40%.In this study,screening and evaluation were performed to identify and categorize 100 cotton genotypes along with 5 checks as resistant,moderately resistant,sensitive and highly sensitive to leafhoppers.Results A total of hundred genotypes were evaluated along with five checks for leafhopper resistance.Based on the screening results,a total of 19 genotypes were resistant to leafhoppers,which was on par with the findings of the check KC 3.The contents of total soluble sugar,total soluble protein,and total free amino acids were significantly positively correlated with the mean grade,whereas total phenols content and trichome density were significantly negatively correlated with the susceptibility grade.However,based on screening and biochemical analysis,the genotypes KC 2,JR-23,Samaru-26-T,D 4,TCH 1728,RS 253,and B-61-1862 exhibited high resistance to leafhopper.Conclusion According to the findings of this study,choosing genotypes with high total phenolics content together with high trichome density and low contents of total soluble sugar,total soluble protein,and free amino acids may aid in the development of resistant genotypes.

Hatching and development of maize cyst nematode Heterodera zeae infecting different plant hosts

The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.

STUDY ON THE HOST BIOLOGICAL INDUCED RESISTANCE OF BACTERIAL CANKER OF POPLAR

This is the first time that biological induced resistance has been used in the research of the bacterial canker on poplar. After inoculated with less-aggressive strains, middle-aggressive strains and non-aggressive strains (high-aggressive strains have been treated with 400W ultraviolet lamp for 30 min on super-clean working table) poplar seedlings have been inoculated with high-aggressive strams. the results of those experiments shown that strain 3 (from Suihua, Heilongjiang)and strain 9 (from Liaoning) can significantly enhance the activities of the peroxidase of host. and the efects of twice inoculation were much better than that of once inoculation. 7. 1 % and 4.0% of the peroxidase activities have been enhanced respectively in the seedlings which were twice inoculation with strains 3 and strains 9. 1. 1 % and 1 .2 % of the peroxidase activities have been enhanced by inoculated strains 3 and strains 9 once into seedlings.

Altered Host Resistance to Listeria monocytogenes In Mice Exposed to 1-Chloroacetophenone (CN) Vapours

Short term repeated exposure of 1-chloroacetophenone (CN) vapours at a concentration of 0.153 mg per litre for 15 minutes daily on 10 consecuitve days in Swiss albino male mice resulted in increased mortality to Listeria monocytogenes. Significantly elevated bacterial growth was observed in the spleen and liver of the CN exposed animals. The increased bacterial count in these organs was evident within 4-6 days post challenge as compared to vehicle exposed infected and unexposed infected animals. Increased susceptibility to infection has been considered to be the function of immune alteration due to cumulative short term effects ofCN vapour inhalation. This may be attributed to immunotoxic effects of CN on Tcells mediated macrophage functions.

Nanoplastics promote the dissemination of antibiotic resistance genes and diversify their bacterial hosts in soil

The wide application of plastics has led to the ubiquitous presence of nanoplastics and microplastics in terrestrial environments.However,few studies have focused on the mechanism underlying the effects of plastic particles on soil microbiomes and resistomes,especially the differences between nanoplastics and microplastics.This study investigated the microbiome and resistome in soil exposed to polystyrene microplastics(mPS)or nanoplastics(nPS)through 16S rRNA and shotgun metagenomic sequencing.Distinct microbial communities were observed between mPS and nPS exposure groups,and nPS exposure significantly changed the bacterial composition even at the lowest amended rate(0.01%,w/w).The abundance of antibiotic resistance genes(ARGs)in nPS exposure(1%)was 0.26 copies per cell,significantly higher than that in control(0.21 copies per cell)and mPS exposure groups(0.21 copies per cell).It was observed that nanoplastics,bacterial community,and mobile genetic elements(MGEs)directly affected the ARG abundance in nPS exposure groups,while in mPS exposure groups,only MGEs directly induced the change of ARGs.Streptomyces was the predominant host for multidrug in the control and mPS exposure,whereas the primary host was changed to Bacillus in nPS exposure.Additionally,exposure to nPS induced several bacterial hosts to exhibit possible multi-antibiotic resistance characteristics.Our results indicated that the effects of plastic particles on the soil microbial community were size-dependent,and nano-sized plastic particles exhibited more substantial impacts.Both microplastics and nanoplastics promoted ARG transfer and diversified their bacterial hosts.These findings bear implications for the regulation of plastic waste and ARGs.

Resistance to Aspergillus flavus in maize and peanut:Molecular biology, breeding, environmental stress,and future perspectives

The colonization of maize(Zea mays L.) and peanut(Arachis hypogaea L.) by the fungal pathogen Aspergillus flavus results in the contamination of kernels with carcinogenic mycotoxins known as aflatoxins leading to economic losses and potential health threats to humans. The regulation of aflatoxin biosynthesis in various Aspergillus spp. has been extensively studied, and has been shown to be related to oxidative stress responses. Given that environmental stresses such as drought and heat stress result in the accumulation of reactive oxygen species(ROS) within host plant tissues, host-derived ROS may play an important role in cross-kingdom communication between host plants and A. flavus. Recent technological advances in plant breeding have provided the tools necessary to study and apply knowledge derived from metabolomic, proteomic, and transcriptomic studies in the context of productive breeding populations. Here, we review the current understanding of the potential roles of environmental stress, ROS, and aflatoxin in the interaction between A.flavus and its host plants, and the current status in molecular breeding and marker discovery for resistance to A. flavus colonization and aflatoxin contamination in maize and peanut. We will also propose future directions and a working model for continuing research efforts linking environmental stress tolerance and aflatoxin contamination resistance in maize and peanut.

Gut microbiota-derived metabolites are novel targets for improving insulin resistance

The gut microbiota plays a key role in metabolic diseases.Gut-microbiota-derived metabolites are found in different dietary sources,including:Carbohydrate(acetate,propionate,butyrate,also known as short-chain fatty acids,as well as succinate);protein(hydrogen sulfide,indole,and phenylacetic acid);and lipids(resveratrol-,ferulic acid-,linoleic acid-,catechin-and berry-derived metabolites).Insulin resistance,which is a global pandemic metabolic disease that progresses to type 2 diabetes mellitus,can be directly targeted by these metabolites.Gutmicrobiota-derived metabolites have broad effects locally and in distinct organs,in particular skeletal muscle,adipose tissue,and liver.These metabolites can modulate glucose metabolism,including the increase in glucose uptake and lipid oxidation in skeletal muscle,and decrease in lipogenesis and gluconeogenesis associated with lipid oxidation in the liver through activation of phosphatidylinositol 3-kinase-serine/threonine-protein kinase B and AMP-activated protein kinase.In adipose tissue,gut-microbiota-derived metabolites stimulate adipogenesis and thermogenesis,inhibit lipolysis,and attenuate inflammation.Importantly,an increase in energy expenditure and fat oxidation occurs in the whole body.Therefore,the therapeutic potential of current pharmacological and non-pharmacological approaches used to treat diabetes mellitus can be tested to target specific metabolites derived from intestinal bacteria,which may ultimately ameliorate the hyperglycemic burden.

Presence of the Potato Late Blight Resistance Gene <i>RB</i>Does Not Promote Adaptive Parasitism of <i>Phytophthora infestans</i>

The gene RB is derived from the wild potato species S. bulbocastanum and confers partial resistance to late blight, caused by the oomycete pathogen Phytophthora infestans. In order to investigate whether a single strain of P. infestans can adapt to overcome this partial resistance source, we subjected RB containing leaflets to multiple rounds of infection with P. infestans, with a culture isolated from a lesion used to infect the next leaflet (a passage). A parallel line of passages was done using susceptible leaflets as hosts. At the end of the experiment, P. infestans strains passaged through resistant or susceptible leaflets were compared for infection efficiency and lesion size. Variants of the P. infestans effector family IPI-O, some of which are recognized by the RB protein to elicit resistance, were cloned and sequenced to determine whether variation occurred during selection on the partially resistant host. Our results show that after 20 rounds of selection, no breakdown in RB resistance took place. In fact, the strain that was continually passaged through the partially resistant host produced smaller lesions on susceptible leaflets and had a lower infection frequency than the strain passaged through susceptible cultivar Katahdin. No changes within IPI-O coding regions were detected after selection on the hosts with RB. Our results indicate that individual strains of P. infestans are not capable of rapidly overcoming RB resistance even when it is the only host available.

Bi-Directional Regulation by Chinese Herbal Formulae to Host and Parasite for Multi-Drug Resistant <i>Staphylococcus aureus</i>in Humans and Rodents

A decline in the immunopotential of the host plays acritical factor(s) in the occurrence of infections with methicillin-resistant Staphylococcus aureus (MRSA) or microorganisms by opportunistic infection. In such an infection, no way out for therapeutic concept, therefore bi-directional trial was the final choice. So we selected aformula, Dang Gui Liu Huang Tang (dLHT), which could both augmentimmune factorsin host and exert bacteriostatic effect. We sought to break through the epidemic by MRSA especially in elderly patient, by the fundamental and clinical trial by employing minor TCM, characterizing bidirectional ability of the decoction by western methods. Animal Experiment: Mitomycin-C (MMC)-treated mice with or without the infection of MRSA were made. The experimental design was made up to examine the bacteriostatic action as well as the immunopo-tentiating bias of the promising Chinese herbal medicine, dLHT, which was first proved for its immune potentiating activities as well as their sensitivity to antibiotics, but not direct aseptic effect was clear for MRSA. Both basic and clinical data showed that this formula was effective on repelling from the infectious focus after the treatment of MRSA infection. After the administration of dLHT, the number of white blood cells in MMC-treated mice recovered to 80% of the normal level. In addition, the phagocytic activity of macrophages increased to 70% in the dLHT-treated group, while that of the non-treated group was only 20%. The bactericidal activity also recovered to the level close to the normal value by dLHT. The ratio of neutrophils in the dLHT-administered group increased to 2.2% (normal mice, 2.6%), whereas that in the non-terated group was only 0.5%. The bacterial count in the liver of MRSA-challenged mice reached the peak at six hours after the challenge in both dLHT-treated and non-treated mice. However, the number of bacteria in dLHT group was much greater than that in the non-treated group. The bacterial count in the blood showed an increase 12 and 24 hours after the challenge. Even 24 hours after the challenge, a significant number of bacteria existed in the blood of dLHT-administered group, whereas only a small number of bacteria detectable 6 hours after the challenge and the number gradually decreased thereafter in the dLHT-administered group. MRSA-challenged MMC-treated mice were treated by dLHT, vancomycin, or dLHT and vancomycin. All of non-treated mice died 8 days after the MRSA challenge, whereas the survival rates were 60% after dLHT treatment, 40% after vancomycin treatment, and 80% after dLHT and vancomycin treatment. All of MMC-treated mice, to which the phagocytic cells prepared from MMC-treated mice with dLHT administration had adoptively been transferred, survived from MRSA challenge. On the other hand, the survival rate of MMC-treated mice, to which the lymphocytes prepared from the same mice had adoptively been transferred, was 40%. Clinical Trial: All cases with dLHT treatment showed negative culture results for MRSA after the dLHT administration. The culture generally became negative less than 50 days after the initial administration, whereas one control case needed more than 100 days and the other was dead of the infection. One representative case, who was a 78-year-old woman suffering from hypertension, atrial fibrillation, and cerebral bleeding in the right occipital lobe, infected with MRSA during the antibiotic therapy for Streptococcus pneumoniae. The antibiotic therapy was halted and the dLHT administration started. Three weeks later, the culture result became negative. In addition, serum protein and albumin values also returned to the level that they had had before the infection of MRSA.

Effects of Microtubule Polymerization Inhibitor on the Hypersensitive Response of Wheat Induced by the Non-Host Pathogen Sphaerotheca fuliginea

The plant cytoskeleton is a highly dynamic and versatile intracellular scaffold composed of microtubules and microfilaments, serving a multiplicity of functions in plant cells. To reveal the relationship between the cytoskeleton in wheat （Triticum aestivum L.） cv. Suwon 11 attacked by the non-host pathogen Sphaerotheca fuliginea and the initiation of the hypersensitive response, the microtubule inhibitor oryzalin was injected into the wheat leaves immediately prior to inoculation. The incidence of hypersensitive cell death was significantly lower than that in water-treated control. In addition, the occurrence of hypersensitive cell death was also delayed and S. fuliginea was able to penetrate and form haustoria in epidermal tissues of wheat. All the results above indicated that hypersensitive cell death was associated with depolymerisation of microtubules, suggesting that microtubules might play an important role in the expression of non-host resistance of wheat.

Differential Responses of Phytophthora sojae to Seed Exudates of Host Soybean and Non-host Maize

In order to clarify the differential response of Phytophthora sojae to the seed exudates of host soybean and non-host maize and understand the relationship between seed exudates and host selectivity of Phytophthora sojae, non-host maize Suiyu 23 and susceptible host soybean Sloan seed exudates were collected to measure their influence on mycelial growth, formation and germination of oospores, chemotaxis, encystment and germination of zoospores of Phytophthora sojae. The results showed that nonhost maize seed exudates exhibited repellency to zoospores of Phytophthora sojae, it also could significantly inhibited Phytophthora sojae mycelial growth, formation of oospores compared with the control;compared with host soybean, non-host maize seed exudates could significantly inhibited Phytophthora sojae mycelial growth, formation and germination of oospores, germination of cysts, which indicated that the seed exudates was the critical factor to host selectivity of Phytophthora sojae and the maize seed exudates was closely related to its non-host resistance.

Tomato mottle mosaic virus: Characterization, resistance gene effectiveness, and quintuplex RT-PCR detection system

Tomato mottle mosaic virus(ToMMV), an economically important species of the genus Tobamovirus, causes significant loss in yield and quality of tomato fruits. Here, we identified the Shandong isolate of ToMMV(ToMMV-SD) collected from symptomatic tomato fruits in Weifang, Shandong Province of China. ToMMV-SD caused symptoms such as severe mosaic, mottling, and necrosis of tomato leaves, yellow spot and necrotic lesions on tomato fruits. The obtained full genome of ToMMV-SD was 6 399 nucleotides(accession number MW373515) and had the highest identity of 99.5% with that of isolate SC13-051 from the United States of America at the genomic level. The infectious clone of ToMMV-SD was constructed and induced clear mosaic and necrotic symptoms onto Nicotiana benthamiana leaves. Several commercial tomato cultivars, harboring Tm-2~2 resistance gene, and pepper cultivars, containing L resistance gene, were susceptible to ToMMV-SD. Plants of Solanum melongena(eggplant) and Brassica pekinensis(napa cabbage) showed mottling symptoms, while N. tabacum cv. Zhongyan 100 displayed latent infection. ToMMV-SD did not infect plants of N. tabacum cv. Xanthi NN, Brassica rapa ssp. chinensis(bok choy), Raphanus sativus(radish), Vigna unguiculata cv. Yuanzhong 28-2(cowpea), or Tm-2~2 transgenic N. benthamiana. A quintuplex RT-PCR system differentiated ToMMV from tomato mosaic virus, tomato brown rugose fruit virus, tobacco mosaic virus, and tomato spotted wilt virus, with the threshold amount of 0.02 pg. These results highlight the threat posed by ToMMV to tomato and pepper cultivation and offer an efficient detection system for the simultaneous detection of four tobamoviruses and tomato spotted wilt virus infecting tomato plants in the field.

Genetic sources and loci for wheat head blast resistance identified by genome-wide association analysis

The emergence and spread of wheat blast caused by fungal pathogen Magnaporthe oryzae pathotype Triticum is a threat to global wheat production.The resistance level and genetic loci for blast resistance in Chinese germplasm remain unknown.A panel of 266 bread wheat accessions from China,CIMMYTMexico and other countries was screened for head blast resistance under 12 field experiments in Bolivia and Bangladesh.Subsequently,a genome-wide association study was performed to understand the genetic basis of wheat blast resistance.The average blast index of all the accessions was 53.7%±12.7%,and 10 accessions including Chinese accessions Yumai 10 and Yu 02321 showed moderate to high levels of blast resistance,accounting for only 3.8%in the panel.Fifty-eight significant SNPs clustered in a 28.9 Mb interval on the 2 AS/2 NS translocation region,explaining phenotypic variation between10.0%and 35.0%.The frequency of the 2 AS/2 NS translocation in the Chinese accessions was as low as4.5%.These results indicated that the 2 NS fragment was the only major locus conferring resistance to wheat blast in this panel,and the resistant and moderately resistant lines identified could be deployed in breeding.

瓜列当在3种寄主作物上的寄生规律及抗性评价

【目的】研究瓜列当在新疆加工番茄、西葫芦和打瓜上的寄生规律及主栽品种对瓜列当的抗性情况,为新疆加工番茄、西葫芦和打瓜田瓜列当的防治提供科学依据。【方法】采用盆栽试验及田间随机调查方法。【结果】瓜列当在加工番茄、西葫芦和打瓜播种34~37 d可建立寄生关系,寄生打瓜上的瓜列当在建立寄生关系5 d后即出土,而寄生于西葫芦和加工番茄上的瓜列当在建立寄生关系18和21 d后才出土;6月21~22日,加工番茄田瓜列当发生率为42.86%,打瓜田为7.14%,西葫芦田无瓜列当;6月28~29日,加工番茄田瓜列当发生率为45.45%,打瓜田为27.27%,西葫芦田为25%;7月5~14日,加工番茄田瓜列当发生率为80%,打瓜田为71.43%,西葫芦田为86.96%;加工番茄品种BVS32瓜列当寄生量最少,加工番茄全生育期瓜列当鲜重和干重分别为20.97和4.26 g/盆;品种金丰八号在西葫芦全生育期中瓜列当寄生量最少,瓜列当鲜重和干重分别为25.65和5.92 g/盆;打瓜品种中黑中片瓜列当寄生量最少,瓜列当鲜重和干重分别为5.38和0.78 g/盆。【结论】加工番茄、西葫芦和打瓜适宜防治瓜列当时间是播种后20 d;新疆北疆区域加工番茄、打瓜和西葫芦田瓜列当最佳防治时间分别为5月下旬至6月中旬、6月中上旬和6月中下旬;新疆主栽的加工番茄、西葫芦、打瓜品种中无对瓜列当免疫的品种,加工番茄品种BVS32、西葫芦品种金丰八号和打瓜品种黑中片瓜列当寄生量最少,可作为新疆抗瓜列当种植品种。

寄主对瓜实蝇老熟幼虫和蛹的低温耐受性的影响

为明确不同寄主饲养的瓜实蝇Bactrocera cucurbitae(Coquillett)幼虫与蛹的低温耐受性差异,选择西葫芦Cucurbita pepo、节瓜Benincasa hispida和黄瓜Cucumis sativus饲养多代的瓜实蝇老熟幼虫和不同日龄的蛹,分别测定其过冷却点、结冰点和在不同低温下的存活率,并进行比较分析。结果表明:取食不同寄主植物的瓜实蝇老熟幼虫过冷却点无显著差异,取食节瓜的老熟幼虫的结冰点[(-5.33±0.23)℃]最低,且与取食黄瓜的种群没有显著差异;取食节瓜的蛹的过冷却点与结冰点均最低,其中1日龄、3日龄和5日龄蛹的过冷却点和结冰点分别为(-19.28±0.30)℃和(-15.06±0.34)℃,(-20.97±0.40)℃和(-17.33±0.39)℃,(-20.08±0.46)℃和(-16.39±0.46)℃。取食节瓜和黄瓜的老熟幼虫在3、6℃和9℃下暴露1 d,其存活率均显著高于取食西葫芦的老熟幼虫;节瓜种群的1日龄蛹在3℃和9℃下暴露1 d时,其存活率都显著高于黄瓜和西葫芦种群的1日龄蛹的存活率。寄主植物可影响瓜实蝇的过冷却点、结冰点及低温存活能力,与其他寄主种群相比,瓜实蝇节瓜种群老熟幼虫和蛹对低温的适应能力更强。

SNHG10低表达与卵巢癌预后和耐药的相关性研究

目的:探讨长链非编码小核仁RNA宿主基因10(SNHG10)与卵巢癌细胞增殖、耐药及预后的关系。方法:通过开放大数据(库)筛选88例正常卵巢组织和426例卵巢癌组织中差异表达SNHGs,分析其与卵巢癌患者预后的相关性,并通过受试者工作特征(ROC)曲线评估SNHGs预警卵巢癌紫杉醇和铂类药物耐药的价值。采用实时荧光定量PCR(RT-qPCR)检测SNHG10在卵巢癌紫杉醇/卡铂耐药细胞(SKOV3-R/SKOV3-CBP)及其亲本细胞(SKOV3)中的相对表达水平。通过慢病毒感染在卵巢癌亲本细胞SKOV3中构建过表达SNHG10的细胞株,分为对照组(S-eGFP组)和过表达组(S-SNHG10组)。采用CCK-8、平板克隆形成实验评估细胞增殖能力;通过Cell Titer-Glo发光活细胞检测法评估细胞对紫杉醇的敏感性。结果:SNHG10在卵巢癌组织显著低表达(P<0.01),其低表达与卵巢癌患者不良预后显著相关(P<0.05),且能潜在预测紫杉醇和铂类化疗耐药(AUC>0.6,P<0.05)。与S-eGFP组相比,S-SNHG10组细胞的增殖能力下降,对紫杉醇的敏感性增强(P<0.001)。结论:过表达SNHG10显著抑制卵巢癌细胞增殖并提高卵巢癌细胞对紫杉醇的敏感性。

异基因造血干细胞移植后短期内死亡的危险因素分析

背景:异基因造血干细胞移植是治愈各种血液病的有效甚至唯一手段,但患者移植后短期内死亡率较高。目的:探讨影响血液病患者异基因造血干细胞移植后短期(100 d)内总体生存的危险因素,旨在降低异基因造血干细胞移植后短期(100 d)内死亡率及有效预防相关危险因素。方法:回顾性分析于2018-01-01/2021-06-30在郑州大学第一附属医院造血干细胞移植中心行异基因造血干细胞移植的585例血液病患者的临床资料,探究影响血液病患者异基因造血干细胞移植后100 d内总体生存的危险因素。结果与结论:共585例血液病患者行异基因造血干细胞移植,92例死于移植后100 d内,死亡率为15.7%(92/585),死亡时中位年龄为26.5岁(1-56岁),死亡病例的中位生存时间为48 d(0-97 d)。单因素分析显示,年龄≥14岁、发生急性移植物抗宿主病、Ⅳ度急性移植物抗宿主病、细菌血流感染及耐碳青霉烯类革兰阴性杆菌血流感染是影响异基因造血干细胞移植后100 d内总体生存的危险因素(P<0.05);多因素分析显示,年龄≥14岁、发生Ⅲ-Ⅳ度急性移植物抗宿主病、细菌血流感染及耐碳青霉烯类革兰阴性杆菌血流感染是影响异基因造血干细胞移植后100 d内总体生存的独立危险因素,相对危险度分别为1.77(95%CI 1.047-2.991),7.926(95%CI 3.763-16.695),2.039(95%CI 1.117-3.722),3.389(95%CI 1.563-7.347)。结果表明:异基因造血干细胞移植后短期内全因死亡率较高,对于移植后短期内合并细菌血流感染、Ⅲ-Ⅳ度急性移植物抗宿主病的患者需及时发现、给予有效治疗,从而改善异基因造血干细胞移植的疗效。

宿主因素对幽门螺杆菌感染患者菌株耐药性的影响

目的分析影响幽门螺杆菌(Helicobacter pylori,Hp)耐药性的宿主因素。方法连续招募2021年11月—2023年10月于南京医科大学附属苏州医院就诊的Hp感染患者为研究对象。取内镜活检标本进行病理诊断、Hp菌株培养和药敏检测,并通过电子病历及问卷收集、纳入19项涉及患者基本资料、生活方式、饮食习惯、健康状况的指标,采用Logistic回归法评估宿主因素与Hp菌株对克拉霉素、左氧氟沙星、阿莫西林、呋喃唑酮、四环素、甲硝唑6种抗菌药物耐药性的相关性。结果共入选符合纳入与排除标准的Hp感染患者115例(Hp菌株115株)。其中男性53例(46.09%)、女性62例(53.91%),平均年龄(45.16±13.39)岁。胃镜病理:浅表性胃炎86例(74.78%),萎缩性胃炎6例(5.22%),肠上皮化生14例(12.17%),低级别上皮内瘤变6例(5.22%),高级别上皮内瘤变/胃癌3例(2.61%)。Hp菌株对抗菌药物的耐药率由高至低分别为甲硝唑(91.30%,105/115)、左氧氟沙星(53.04%,61/115)、克拉霉素(51.30%,59/115),未发现对阿莫西林、呋喃唑酮、四环素耐药菌株。双重耐药:左氧氟沙星+甲硝唑双重耐药率为50.43%(58/115),克拉霉素+甲硝唑双重耐药率为47.83%(55/115),克拉霉素+左氧氟沙星双重耐药率为36.52%(42/115)。多重耐药:克拉霉素+左氧氟沙星+甲硝唑三重耐药率为34.78%(40/115)。多因素Logistic回归分析结果显示(由于无对甲硝唑敏感毒株,多因素分析未纳入该药物),既往Hp根除史(OR=74.782,95%CI:10.377~538.886,P<0.001)、家庭饮用水来源为自来水(OR=4.919,95%CI:1.160~20.859,P=0.031)可增加菌株对克拉霉素的耐药风险,年龄≥50岁可增加菌株对左氧氟沙星的耐药风险(OR=4.261,95%CI:1.420~12.785,P=0.010),既往Hp根除史(OR=5.855,95%CI:2.209~15.517,P<0.001)、年龄40~59岁(OR=3.269,95%CI:1.254~8.520,P=0.015)可增加菌株对克拉霉素+左氧氟沙星双重耐药的风险。结论南京医科大学附属苏州医院Hp感染患者分离培养的菌株对甲硝唑、左氧氟沙星、克拉霉素的耐药率较高,且双重耐药、多重耐药现象突出。年龄、既往Hp根除史、家庭饮用水来源可能与克拉霉素、左氧氟沙星单药或双重耐药具有相关性。临床在进行Hp根除时,应综合考量,合理选择抗菌药物,个体化制订治疗方案。

2种蚜虫取食诱导棉花对棉长管蚜与棉蚜取食行为的影响

为研究棉长管蚜Acyrthosiphon gossypii与棉蚜Aphis gossypii对蚜虫取食诱导棉花的取食适应性,揭示取食诱导下两种蚜虫的取食竞争机制,采用刺探电位图谱技术(electrical penetration graph, EPG)测定在健康棉花、棉长管蚜或棉蚜诱导的棉花上取食6 h的棉长管蚜和棉蚜的16个重要参数,比较两种蚜虫的取食行为。研究发现:1)取食健康棉花时,棉蚜在木质部(G波)的取食持续总时间长于棉长管蚜,棉蚜在木质部的取食能力大于棉长管蚜,但二者在韧皮部的取食能力相差不大。2)取食棉长管蚜诱导的棉花时,棉蚜取食韧皮部(E2波)持续的总时间为(2 531.33±60.86)s,显著大于棉长管蚜E2波持续总时间[(2 196.00±98.91)s];取食棉蚜诱导的棉花时,棉蚜取食韧皮部、木质部持续的总时间显著长于棉长管蚜(P<0.05),说明棉蚜对于棉蚜诱导棉花的取食耐受性大于棉长管蚜。棉蚜对两种蚜虫取食诱导棉花的适应性更强,更易在竞争中取得优势。棉长管蚜与棉蚜取食棉长管蚜或棉蚜诱导棉花的F波持续总时间长于健康棉花,说明经取食诱导的棉花具有一定的抗虫性。