Enzymatic pretreatment mitigates the dissemination of antibiotic resistance genes via regulating microbial populations and gene expressions during food waste fermentation

Food waste(FW)has been recognized as essential reservoir for resource recovery via anaerobic fermentation,which could also bring the potential risk of antibiotic resistance genes(ARGs)dissemination.Although the structural deficiency of FW could be stimulated by enzymatic pretreatment to enhance fermentation efficiency,the influences of enzymatic pretreatment on ARGs fate and microbial metabolic pathways involved in ARGs dissemination have rarely been reported.This work proved that enzymatic pretreatment could effectively decrease the total abundance of ARGs(reduced by 13.8%-24.5%)during long-term FW fermentation.It was found that enzymatic pretreatment significantly reduced the ARGs belonging to the efflux pump,which might be ascribed to its ability to increase membrane permeability.Furthermore,enzymatic pretreatment was in favor of reducing microbial diversity and various potential ARGs host(e.g.,Methanosarcina,Clostridium,Prevotella,Parabacteroides).Also,this pretreatment remarkably up-regulated the genetic expressions involved in ABC transporter(e.g.,eryF and mntA)and down-regulated the genetic expressions that participated in DNA replication,two-component systems(e.g.,uphA and cckA),and quorum sensing(e.g.,rpfF and lsrG),thereby decreasing ARGs transmission.This study would expand the insight of the influences of pretreatment method on ARGs fate during FW fermentation,and offer practical guidance on the sustainable management of FW.

A global perspective on microbial risk factors in effluents of wastewater treatment plants

Effective monitoring and management of microbial risk factors in wastewater treatment plants(WWTPs)effluents require a comprehensive investigation of these risks.A global survey on microbial risk factors in WWTP effluents could reveal important insights into their risk features.This study aims to explore the abundance and types of antibiotic resistance genes(ARGs),virulence factor genes(VFGs),the vector of ARG/VFG,and dominant pathogens in global WWTP effluents.We collected 113 metagenomes of WWTP effluents from the Sequence Read Archive of the National Center for Biotechnology Information and characterized the microbial risk factors.Our results showed that multidrug resistance was the dominant ARG type,while offensive virulence factors were the most abundant type of VFGs.The most dominant types of ARGs in the vector of plasmid and phage were both aminoglycoside resistance,which is concerning as aminoglycosides are often a last resort for treating multi-resistant infections.Acinetobacter baumannii was the most dominant pathogen,rather than Escherichia coli,and a weak negative correlation between Escherichia coli and two other dominant pathogens(Acinetobacter baumannii and Bacteroides uniformis)suggests that using Escherichia coli as a biological indicator for all pathogens in WWTP effluents may not be appropriate.The Getah virus was the most dominant virus found in global WWTP effluents.Our study presents a comprehensive global-scale investigation of microbial risk factors in WWTP effluents,providing valuable insights into the potential risks associated with WWTP effluents and contributing to the monitoring and control of these risks.

Mesophilic and thermophilic anaerobic digestion of swine manure with sulfamethoxazole and norfloxacin:Dynamics of microbial communities and evolution of resistance genes

The role of norfloxacin(NOR)and sulfamethoxazole(SMX)in mesophilic and thermophilic anaerobic digestion(AD)of pig manure,with respect to methane production and variations in the microbial community and resistance genes,including antibiotic resistance genes(ARGs),class I integrase(intIl),and heavy metal resistance genes(MRGs),was investigated.The results indicated that NOR exerted little influence on the microbial community,whereas SMX negatively affected the acetoclastic methanogens.The abundance of two sulfonamide resistance genes(sul1 and sul2),three quinolone resistance genes(qnrS,parC,and aac(6′)-Ib-cr),and intI1 decreased by 2–3 orders of magnitude at the end of thermophilic AD.In contrast,mesophilic AD was generally ineffective in reducing the abundance of resistance genes.According to the results of redundancy analysis,the abundance of ARGs was affected primarily by microbial community dynamics(68.5%),rather than the selective pressure due to antibiotic addition(13.3%).Horizontal gene transfer(HGT)through intI1 contributed to 26.4%of the ARG variation.The archaeal community also influenced the changes in the resistance genes,and ARG reduction was significantly correlated with enhanced methane production.Thermophilic AD presented a higher methane production potential and greater reduction in resistance gene abundance.

Enhancing sensitivity of microbial fuel cell sensors for low concentration biodegradable organic matter detection:Regulation of substrate concentration,anode area and external resistance

The relatively low sensitivity is an important reason for restricting the microbial fuel cell(MFC)sensors'application in low concentration biodegradable organic matter(BOM)detection.The startup parameters,including substrate concentration,anode area and external resistance,were regulated to enhance the sensitivity of MFC sensors.The results demonstrated that both the substrate concentration and anode area were positively correlated with the sensitivity of MFC sensors,and an external resistance of 210Ωwas found to be optimal in terms of sensitivity of MFC sensors.Optimized MFC sensors had lower detection limit(1 mg/L)and higher sensitivity(Slope value of the linear regression curve was 1.02),which effectively overcome the limitation of low concentration BOM detection.The essential reason is that optimized MFC sensors had higher coulombic efficiency,which was beneficial to improve the sensitivity of MFC sensors.The main impact of the substrate concentration and anode area was to regulate the proportion between electrogens and nonelectrogens,biomass and living cells of the anode biofilm.The external resistance mainly affected the morphology structure and the proportion of living cells of the anode.This study demonstrated an effective way to improve the sensitivity of MFC sensors for low concentration BOM detection.

Antimicrobial Resistance Profile of Bacteria Isolated from Boreholes and Hand Dug Wells Water in Ngaoundere Municipality of Adamawa Region in Cameroon

Uncontrolled uses of antibiotics have led to rapid evolution of antibiotic-resistance bacteria and antibiotic resistance gene transfer, especially in a pool of aquatic system where resistance, intermediate and susceptible bacteria to some antibiotics strive together. Consequently, there is a transfer of resistance genes. In this study, bacteria of the Enterobacteriaceae family and some gram positive bacteria isolated from some boreholes and hand dug wells water of public use were tested on 19 antibiotics of different classes. This was achieved through a disk diffusion technique to determine the antimicrobial resistance profile of the said bacteria, microbial resistance index of the drugs used (and their ability to produce Beta-lactamase). These isolates were shown to demonstrate a very high resistance to the drugs used in the area. The resistance was highest in Escherichia coli 1 (73.68%) and lowest in Streptococcus pneumoniae (47.82%). These isolates also indicated very high levels of multi-drug resistance. The minimum resistance index was 0.47, indicating that bacteria isolates were of fecal origin. It is evident from the present study that multiple antibiotic-resistant bacteria can thrive in water as an environmental reservoir, and can therefore provide a route to multidrug-resistant pathogens to enter human and animal population.

Seasonal variations of microbial community and antibiotic resistome in a suburb drinking water distribution system in a northern Chinese city

Antibiotic resistance genes(ARGs)are an emerging issue for drinkingwater safety.However,the seasonal variation of ARGs in drinking water distribution systems(DWDS)is still unclear.This work revealed the tempo-spatial changes of microbial community,ARGs,mobile genetic elements(MGEs)co-occurring with ARGs,ARG hosts in DWDS bulk water by means of metagenome assembly.The microbial community and antibiotic resistome varied with sampling season and site.Temperature,ammonia,chlorite and total plate count(TPC)drove the variations of microbial community structure.Moreover,environmental parameters(total organic carbon(TOC),chlorite,TPC and hardness)shifted antibiotic resistome.ARGs and MGEs co-occurring with ARGs showed higher relative abundance in summer and autumn,which might be attributed to detached pipe biofilm.In particular,ARG-bacitracin and plasmid were the predominant ARG and MGE,respectively.ARG hosts changed with season and site and were more diverse in summer and autumn.In winter and spring,Limnohabitans and Mycobacterium were the major ARG hosts as well as the dominant genera in microbial community.In addition,in summer and autumn,high relative abundance of Achromobacter and Stenotrophomonas were the hosts harboring many kinds of ARGs and MGEs at site in a residential zone(0.4 km from the water treatment plant).Compared with MGEs,microbial community had a greater contribution to the variation of antibiotic resistome.This work gives new insights into the dynamics of ARGs in full-scale DWDS and the underlying factors.

抗枯萎病香蕉品种宿根连作根际土壤微生物群落结构特征变化分析

【目的】分析抗枯萎病香蕉品种宿根连作根际土壤微生物群落结构特征变化,为深入研究抗枯萎病香蕉品种宿根连作抗性增强的作用机制及利用生防微生物进行香蕉枯萎病绿色防控提供理论依据。【方法】以抗枯萎病香蕉品种宝岛蕉为试验材料,在枯萎病发病严重土壤上宿根连续种植3造:组培苗第一代(第1造)、宿根第一代(第2造)和宿根第二代(第3造),调查各造枯萎病发病率,四分法采集各造土壤样本并测定土壤化学性质;采集第1造健康和发病植株、第2和第3造健康植株的根际土壤样本,分别编号为S1、V、S2和S3,重复3次,利用Illumina高通量测序平台对12个土壤样本的细菌16Sr RNA和真菌ITS区进行测序分析;采用样本复杂度(Alpha多样性指数)、主坐标(PCoA)和UPGMA聚类分析土壤样本细菌和真菌群落的丰富度和多样性、门和属水平上的群落构成及相对丰度差异;通过Spearman分析优势微生物群落与镰刀菌属的相关性。【结果】抗枯萎病香蕉品种宝岛蕉连续种植3造根际土壤化学性质未发生明显改变,种植第3造的香蕉枯萎病发病率显著低于第1和第2造(P<0.05)。随着种植年限的增加,根际土壤细菌群落的多样性整体呈逐年下降趋势,而真菌群落的多样性整体呈逐年上升趋势。连作改变了香蕉根际土壤微生物的群落构成,S2和S3细菌和真菌的群落结构相近,明显与S1和V群落结构分离。S2和S3的壶菌门(Chytridiomycota)的相对丰度较S1分别低88.02%和89.51%,Fungi_phy_Incertae_sedis的相对丰度分别高41.56%和82.81%,S3镰刀菌属(Fusarium)的相对丰度较S1、S2分别低45.60%和50.47%,与留芽种植宿根蕉抗性表现增强相关。发病植株根际土壤中变形菌门(Proteobacteria)和担子菌门(Basidiomycota)的相对丰度较高,而酸杆菌门(Acidobacteriota)的相对丰度较低。球囊菌门(Glomeromycota)、毛霉门(Mucoromycota)、隐真菌门(Rozellomycota)和壶菌门(Chytridiomycota)的相对丰度均与镰刀菌呈负相关。【结论】宿根第3造蕉的发病率最低,其根际土壤与第1造发病植株根际土壤的细菌和真菌群落差异明显,推测根际土壤微生物群落丰富度、多样性和群落构成改变是抗枯萎病香蕉品种宿根连作抗性增强的原因。

施肥对我国黑土农田土壤微生物群落多样性影响的研究及展望

东北黑土是珍贵的土壤资源,由于长期的重用轻养,农田黑土退化问题已是一个不争的事实。施肥是保持/提高黑土农田生产力、保障作物产量的一项重要的农艺措施。本文综述了长期施用有机肥、无机肥、有机无机肥配施,以及无机肥氮(N)、磷(P)、钾(K)及其不同的组合施肥对黑土农田土壤细菌、真菌、固氮菌、反硝化细菌等微生物的数量、群落alpha多样性和beta多样性等方面影响的最新研究进展。发现研究结果因试验地点、季节气候、试验处理、目标微生物种类、甚至研究者的采样年限而不同。多数研究发现,长期施用化肥,特别是氮肥显著地降低了细菌丰度和alpha多样性指数,但对真菌丰度和alpha多样性指数影响不显著。不同施肥明显改变了黑土微生物beta多样性,但这种改变是有限的,相同施肥处理没有驱动不同试验地点土壤微生物群落结构同质化演替,表明东北黑土微生物分布具有很强的地域性。对长期施用不同的无机肥研究发现,N素较P素和K素在驱动黑土农田土壤微生物群落变化上作用更为明显。在论述长期施用有机肥改变土壤微生物群落结构的同时,也阐述了有机肥施用带来潜在的抗生素抗性基因污染的生态风险及对抗性基因的阻控措施。文章最后总结了目前施肥影响黑土农田微生物研究中存在的不足之处,并提出5点未来应加强的研究建议。

广州市“十二五”与“十三五”期间利福平耐药肺结核患者发现与治疗情况分析

目的:分析广州市“十二五”与“十三五”结核病防治规划期间利福平耐药肺结核(RR-PTB)患者发现与治疗情况,为进一步制定本地区RR-PTB防治规划提供科学依据。方法:通过“中国疾病预防控制信息系统”子系统“结核病信息管理系统”,按照登记时间导出2011年1月1日至2020年12月31日,即“十二五”(2011—2015年)和“十三五”(2016—2020年)规划期间广州市登记的肺结核患者耐药病案数据(包括性别、年龄、民族、职业、户籍、耐药类型、治疗分类等相关信息),筛选出利福平耐药患者病案,分析患者登记、人群特征、耐药筛查和治疗转归情况。结果:2011—2020年,RR-PTB患者年均登记率为0.71/10万(1152/16286.08万),从2011年的0.31/10万(42/1346.32万)上升至2015年的0.38/10万(60/1594.95万)和2020年的0.97/10万(182/1874.03万),呈逐年上升趋势(χ_(趋势)^(2)=256.395,P<0.001)。其中,“十二五”期间年均登记率为0.34/10万(250/7358.06万),不同年份登记率的差异无统计学意义(χ_(趋势)^(2)=4.674,P=0.322);“十三五”期间年均登记率为1.01/10万(902/8928.02万),不同年份登记率的差异有统计学意义(χ_(趋势)^(2)=38.439,P<0.001)。1152例患者中,以男性(851例,73.87%)、25~34岁青壮年(257例,22.31%)和家政家务及待业(364例,31.60%)为主;流动人口、初治、RR-PTB(除异烟肼耐药)、广泛耐药肺结核比例分别从“十二五”的8.80%(22/250)、11.20%(28/250)、0.00%(0/250)和0.00%(0/250)上升到“十三五”的54.43%(491/902)、37.14%(335/902)、19.84%(179/902)和0.78%(7/902),差异均有统计学意义(χ^(2)=91.370、298.740、97.915、34.096,P值均<0.001)。广州市耐药肺结核高危人群筛查率由2017年的60.91%(148/243)上升至2020年的98.95%(568/574),新发/初治病原学阳性肺结核耐药应筛查率由2018年的83.93%(1410/1680)提高到2020年的94.99%(3222/3392),差异均有统计学意义(χ_(趋势)^(2)=425.043、269.670,P值均<0.001)。纳入治疗、完成治疗和治疗成功的患者比例分别从“十二五”的81.20%(203/250)、2.46%(5/203)和45.81%(93/203)提高到“十三五”的91.02%(821/902)、33.62%(276/821)和67.48%(554/821),治疗失败患者比例从17.73%(36/203)降低至2.68%(22/821),差异均有统计学意义(χ^(2)=19.112、86.809、46.636、58.572,P值均<0.001)。结论:在“十二五”与“十三五”规划期间,广州市RR-PTB的防治工作取得了显著的成效。下一步工作中需继续坚持政府主导、多部门合作和全社会共同参与的原则,切实落实结核病防治规划要求,加强结核病防治服务体系建设。

微塑料和多种抗生素胁迫下土壤环境因子的响应特性

为了深入探究微塑料(microplastics,MPs)、抗生素胁迫下土壤环境因子产生的响应特性,以聚乙烯(polyethylene,PE)、四环素(tetracycline,TC)、环丙沙星(ciprofloxacin,CIP)为研究对象,通过单独、联合施用到土壤中4周后,开展了土壤的理化性质、酶活性、抗生素残留、抗生素抗性菌(antibiotics resistant bacteria,ARB)抗性、抗生素抗性基因(antibiotic resistance genes,ARGs)、微生物群落的多样性等方面研究.结果显示,施用MPs与抗生素的容重比对照组分别增大了12.3%、16.9%、 21.8%.有机质含量由39.96g·kg^(-1)变化为53.21g·kg^(-1),与对照组相比分别增大了9.16%、12.39%、14.09%、18.47%、32.03%、33.16%、36.04%.阳离子交换量由对照组的44.36 cmol·kg^(-1)显著变化为62.45 cmol·kg^(-1),与对照组相比分别增大了24.06%、30.09%、33.97%、36.49%、47.14%、50.93%、56.1%.实验各组pH值在7.58—8.12之间变化.实验各组的过氧化氢酶含量分别为1.653、 1.559、1.421、1.486、1.376、1.545、1.524、1.453 IU·g^(-1);脲酶含量分别为89.56、78.32、64.65、66.79、57.27、72.31、 71.26、 61.56IU·g^(-1);蔗糖酶含量分别为158.69、 149.61、 134.56、 131.87、 123.65、 137.26、136.83、 126.34 IU·g^(-1). MPs-TC-CIP组的过氧化氢酶活性、脲酶活性、蔗糖酶活性分别下降12.1%、32.3%、26.7%. MPs-TC、MPs-CIP组与TC、CIP实验组相比,抗生素残留量有所降低,分别为187.1%、189.3%;MPs-TC-CIP实验组的抗生素残留则低于单一施用CIP、TC组,分别为182.6%、178.7%.筛选的TC抗性菌(TC resistant bacteria,TCRB)和CIP抗性菌(CIP resistant bacteria,CIPRB)的抗性增加2倍以上. MPs-TC-CIP组与对照组相比,tet W、tet O的相对丰度比值分别为1.82、1.78;qnr A、qnr S的相对丰度比值分别为1.68、1.71.各组中相对丰度较高菌群依次为变形菌(Proteobacteria),放线菌(Actinobacteria)、酸杆菌(Acidobacteria)、芽单胞菌(Gemmatimonadetes)、厚壁菌(Fimicutes).施用抗生素、MPs后Proteobacteria、Actinobacteria相对丰度增加、myxococcus相对丰度减少.研究结果表明,施用MPs能促进抗生素的富集;在共同胁迫下,对土壤理化特性和生物特性影响更为显著,进一步探明了MPs对抗生素残留、ARGs传播、微生物群落演化特征等潜在影响,以期为消减污染物的危害、构建综合智能修复体系提供依据.

微生物菌剂与植物协同修复铅污染土壤

为了有效修复和美化污染的土壤环境,降低重金属的污染,将培养生物菌剂与2种富集植物联合修复铅(Pb)污染的土壤,通过微生物培养、高效液相色谱、微生物群落多样性分析等方法,研究土壤中重金属残留、酶活性、叶绿素含量、重金属抗性菌、微生物数量和群落多样性。结果表明:Pb污染浓度为400 mg/kg,分别经过联合修复30 d和60 d,土壤中重金属浓度分别下降了19.61%、19.48%,60 d比30 d吸附率分别提高了16.82%、17.83%。过氧化氢酶由对照组的5.6 mg/kg增加到11.4、15.9 mg/kg;碱性磷酸酶的活性由45.6 mg/kg增加到88.4、93.4 mg/kg;蔗糖酶的活性由4.2 mg/kg增加到9.6、9.9 mg/kg;脲酶的活性由32.6 mg/kg增加到66.3、71.2 mg/kg。叶绿素的含量分别增加9.16%、9.18%。重金属抗性菌检出量分别减少21.31%和20.27%。细菌、真菌和放线菌的数量最高增加了97.68%、67.63%、210.09%。微生物群落多样性和丰度也相应增加2.7%、2.9%。可见污染土壤经过微生物菌剂与植物联系修复后,植物的光合作用增强,加快重金属的吸附和转运,提高酶活性,提升植物对重金属的耐受性,重金属抗性菌数量显著降低,微生物群落多样性增加;阐明微生物菌剂和植物协同作用下对重金属污染土壤的强化修复机制,为高效治理土壤污染提供科学依据。

耐高温和耐低温固体复合菌剂对牛粪堆肥的影响

为解决低温时牛粪堆肥时间长的问题,缩短堆肥发酵周期,提高有机肥品质,试验将筛选到的8株细菌制成耐高温和耐低温固体复合菌剂,加入牛粪堆肥中设为试验组(T组),不加菌剂自然堆肥设为对照组(C组),检测理化指标、物种组成和优势微生物,验证制备的复合菌剂对冬季牛粪堆肥启动和堆肥高温期的作用。结果表明:添加固体复合菌剂后,T组相比C组,堆肥初期温度启动和上升速度更快,提前2 d达到高温期且最高温高出3.4℃;pH上升和下降变化幅度均大于C组,最终维持在8.1左右;堆肥结束时,含水率、C/N和有机质均下降,全磷、全钾和种子发芽率(GI)均上升,T组下降和上升幅度大;优势微生物门水平T组堆肥初期(T1)为Firmicutes和Actinobacteria,升温期(T2)为Firmicutes,高温期(T3)为Bacteroidetes,降温期(T4)和腐熟期(T5)为Actinobacteria和Chloroflexi,Proteobacteria是整个堆肥过程的优势微生物,C组与T组多样性相似,区别在于丰度比例不同,高通量测序发现,堆肥温度和微生物数量是影响堆肥的关键因素。综上,牛粪堆肥前添加制备的耐高温和耐低温固体复合菌剂,能够快速启动冬季堆肥初始温度并延长高温期时间,缩短堆肥时间,提高堆肥效率和有机肥品质。

农药厂废水排放对淤泥微生物群落的影响

农药生产废水毒性大、浓度高、组分复杂,其处理工艺主要依赖于微生物降解,然而经降解后的达标废水对生态环境和抗生素抗性基因分布格局的影响仍不清楚.为探究重庆市某农药生产厂产生的废水经处理后排放对微生物群落及其抗性基因水平影响,采集农药生产过程中废水处理前和排污口溪流的相关淤泥样品,通过16S rRNA高通量测序技术及抗生素抗性基因的检测,研究农药生产废水处理环境下细菌群落的结构功能变化.处理池淤泥样品(pool sludge sample,PSS)α多样性显著低于小溪底泥样品(brook sludge sample,BSS),但BSS中菌群结构随排污口距离增加仍保持相对稳定.PSS中富含大量农药降解相关微生物,并显著富集农药降解相关代谢通路,表现出对多种农药的降解能力.氨基糖苷类、β内酰胺类、氯霉素类、氟喹诺酮类抗生素抗性基因的丰度在排污口较高,但多数高丰度菌属并未与抗生素抗性基因丰度显著相关.PSS中农药降解相关细菌丰富,并与BSS菌群组成差异明显.研究范围内BSS微生物群落并未明显产生响应排污口距离的梯度变化.BSS抗生素抗性水平并非由单一菌属决定,可能由多个菌属共同介导.

世界卫生组织《结核分枝杆菌耐药相关基因突变目录(第2版)》解读

耐药结核病是2035年实现全球终结结核病流行目标的巨大障碍。世界卫生组织(World Health Organization,WHO)倡导采用快速分子药物敏感性检测技术进行耐药结核病早期诊断,而覆盖全面可靠的耐药检测靶标是提高分子药物敏感性检测技术可靠性的关键。WHO于2023年11月发布《结核分枝杆菌耐药相关基因突变目录(第2版)》,目的是基于更广泛的全球数据汇总形成更为全面准确的耐药相关基因突变目录,为开发与完善基于测序或其他方法的新型分子药物敏感性检测技术提供支持。本文对第2版目录相较于第1版目录在分析流程与耐药突变等内容的更新进行了详细的解读,并对未来目录完善的方向进行了展望。

昆虫对杀虫剂和转Bt基因植物的抗性进化机制研究进展

为防治昆虫对农作物的危害,采取了喷施杀虫剂和种植转Bt基因抗虫植物等措施。然而,杀虫剂的大规模使用和转Bt基因抗虫植物的大面积连续种植使得一些靶标昆虫产生了抗性进化,这不仅影响防治效果,而且还影响整个农业生态系统服务功能。本文综述了昆虫对化学杀虫剂、微生物杀虫剂和转Bt基因植物产生抗性的分子机制。昆虫对化学杀虫剂的抗性进化机制主要是靶标位点敏感性下降和解毒酶系活性增强;对微生物杀虫剂的抗性进化机制主要是免疫系统激活和共生菌群变化;对转Bt基因植物的抗性进化机制主要是昆虫中肠结合受体基因突变或表达下调和中肠蛋白酶活性降低。为了减缓昆虫抗性进化和提高杀虫剂效率,未来建议减少使用化学杀虫剂,合理利用杀虫谱广和活性高的微生物杀虫剂以及抗虫植物等方法系统治理农业害虫。

2013―2022年某医院肺泡灌洗液病原菌分布及耐药性分析

目的分析华中科技大学同济医学院附属同济医院2013―2022年肺泡灌洗液标本中病原菌分布及常见病原菌的耐药性情况。方法采用回顾性调查研究方法,收集华中科技大学同济医学院附属同济医院2013年1月至2022年12月共送检的36233例肺泡灌洗液标本,从中分离出非重复病原菌11801株。使用WHONET5.6版软件对培养及体外药敏试的结果进行分析研究。结果11801株病原菌中革兰阴性菌占69.75%(8231/11801),革兰阳性菌占11.68%(1378/11801),真菌占18.57%(2192/11801)。肺炎克雷伯菌(KPN)对阿米卡星、亚胺培南、美罗培南和替加环素敏感性超过70.00%,铜绿假单胞菌(PAE)对除复方新诺明和米诺环素外大多数抗生素敏感性超过40.00%,鲍曼不动杆菌(ABA)对除米诺环素外大多数抗生素耐药性超过75.00%。在最主要致病菌KPN中耐碳青霉烯肺炎克雷伯菌(CRKPN)占比增高的同时耐药性增强;耐甲氧西林金黄色葡萄球菌(MRSA)占比较高,且耐药率高于甲氧西林敏感金黄色葡萄球菌(MSSA);肺炎链球菌(SPN)中绝大部分为青霉素敏感肺炎链球菌(PSSP)。结论2013―2022年华中科技大学同济医学院附属同济医院肺泡灌洗液标本分离病原菌主要包括KPN、PAE、ABA和金黄色葡萄球菌(SAU)等,且CRKPN耐药率呈上升趋势,临床需合理用药以降低其耐药性。

耐盐菌生物强化耦合催化臭氧氧化处理渗滤液RO浓液及微生物特性分析

针对传统生物工艺处理RO浓液耐盐性差、处理效率低等问题,本研究利用耐盐菌强化厌氧/好氧(A/O)活性污泥耦合催化臭氧氧化工艺以提升有机物和总氮的去除,对比活性污泥、耐盐菌剂、活性污泥+耐盐菌剂的3种体系对RO浓液中污染物去除效果、处理前后有机物成分变化以及微生物特性差异.结果表明,较单独厌氧活性污泥和耐盐菌体系,厌氧强化体系有机氮的转化率分别提高了42%和37%;较单独好氧活性污泥和耐盐菌体系,好氧强化体系总氮去除率提升了37%和77%.气质联用分析显示,原水有机物经生物和臭氧氧化处理后促使一些不饱和键断裂,提高了难降解有机物的降解.处理后,水质指标可达《生活垃圾填埋场污染控制标准》表2标准.高通量测序结果表明,Flavobacterium可能在厌氧强化体系高盐条件下的氨化过程中发挥关键作用;而Truepera、Paracoccus是好氧强化体系高盐条件下总氮高效去除的关键功能菌属.功能基因预测结果显示,氨化基因npr是Flavobacterium菌属的关键基因,进一步证实测序结果推测;好氧强化体系中nap、nar、nir、nor反硝化基因的相对丰度均高于单独体系,揭示了强化体系总氮高效去除的机理.

混菌发酵对菠萝苹果复合果酒品质改善的研究

研究表明发酵菌种是影响果酒品质的关键因素,基于不同菌种的互补作用的混菌发酵方式是改善果酒品质的重要途径.本研究利用酿酒酵母(Saccharomyces cerevisiae)、库德里阿兹威毕赤酵母(Pichia kudriavzevii)和植物乳植杆菌(Lactiplantibacillus plantarum)分别进行菠萝苹果复合果酒的单菌与混菌发酵,并对发酵过程中的理化指标和抗氧化性进行分析,同时对发酵产生的风味物质进行分析比较.相比于单菌发酵,酿酒酵母、库德里阿兹威毕赤酵母与植物乳植杆菌混菌发酵(SKP组)糖利用率最高,还原糖质量浓度最低,为5.26±0.26 g/L,总酸质量浓度为6.79±0.20 g/L.相较于其他组,SKP组抗氧化性最强,总酚质量浓度最高,为261.20±2.61 mg/L,超氧阴离子浓度最低,为36.96±0.74μmol/mL,羟自由基清除率最高,为83.73%±0.84%.研究发现乙酸和乳酸是菠萝苹果复合果酒发酵产生的主要有机酸,且SKP组乳酸质量浓度最高.共检出30种挥发性化合物,相比单菌发酵,酿酒酵母和库德里阿兹威毕赤酵母两菌发酵组(SK组)和三菌发酵组(SKP组)都增加了酯类和高级醇的质量浓度,增加了菠萝苹果复合果酒的香气复杂性.感官评价发现SKP组在口感、香气和色泽方面得分均最高,总分为87.37±0.67分,口感酸甜适中,颜色透亮,改善了菠萝苹果复合果酒的口感和香气复杂度.因此,混菌发酵有助于提升菠萝苹果复合果酒的品质.