16例婴幼儿败血症猪霍乱沙门菌感染的耐药性分析

目的为临床针对婴幼儿败血症猪霍乱沙门菌感染的抗菌药物合理选用提供依据及预防和减少耐药菌株的产生和流行。方法分析我院2008-2011年经血液分离16株猪霍乱沙门菌的耐药性,并对其对不同抗菌药物药敏试验结果及耐药性进行分析。结果分离出的猪霍乱沙门菌80%耐3种以上抗生素,对氯霉素、氨苄西林、复方新诺明耐药率高,分别为75%、81.25%、87.25%;对头孢菌素、喹诺酮类耐药率低,分别有1株对头孢他啶中介,1株对头孢噻肟中介,5株对环丙沙星中介,1株对左旋氧氟沙星中介。结论猪霍乱沙门菌对临床常用的抗生素有较高的耐药性,头孢类可作为猪霍乱沙门菌感染的首选药,临床治疗婴幼儿败血症猪霍乱沙门菌感染应根据药敏结果合理使用抗菌药物。     

婴幼儿感染猪霍乱沙门菌耐药基因特点及同源性分析

目的研究致婴幼儿败血症猪霍乱沙门菌的耐药基因特点及同源性。方法16株猪霍乱沙门菌．采用K—B纸片扩散法检测抗菌药物的耐药性,同时用PCR法及DNA测序法对其进行β-内酰胺酶类耐药基因检测;PFGE法测定同源性。结果对氨苄西林耐药的13株猪霍乱沙门菌经PCR扩增后并测序为bl岫。16株猪霍乱沙门菌经PFGE分型,可分为5个PFGE型,其中A型是最主要的克隆（12／16）。13株blTEM-1．基因阳性菌株分别为A型11株,B型1株,D型1株。结论产TEM-1割β-内酰胺酶是本地区猪霍乱沙门菌对氨苄西林耐药的主要机制,PFGE分型方法对猪霍乱沙门菌分型能力较好。克隆性传播为猪霍乱沙门菌的主要传播途径．同一PFGE型菌株的耐药谱非常接近。     

2006-2012年上海市基于网络实验室的肠炎沙门菌耐药监测

目的 建立区域性网络实验室监测和分析肠炎沙门菌的耐药特征变化为科学防治提供参考依据。 方法 2006-2012年,上海市8个区域公共卫生实验室和24家临床实验室依据标化方法分离184株肠炎沙门菌食源环境菌株与1146株肠炎沙门菌腹泻病例菌株,使用纸片扩散法(K-B法)检测菌株对16种抗生素的耐药性,应用WHONET软件建立耐药数据库。 结果 历年中肠炎沙门菌在禽肉中污染率最高(155/184);实验室诊断病例主要分布在5岁以下和18~59岁、1~4岁病例明显高于1岁以下、60岁以上病例呈逐年上升趋势。所有肠炎沙门菌对萘啶酸耐药率均超过90%;多重耐药株(对氨苄西林-氯霉素-链霉素-磺胺异噁唑-四环素耐药型,ACSSuT)存在于鸡肉和2009年的1例食物中毒暴发病例中;耐头孢吡肟食源和腹泻株分别出现在2011年和2008年;腹泻株对环丙沙星和头孢噻肟的耐药率高于食源株;低年龄组病例对三代头孢和环丙沙星耐药的菌株分别约占2/3和1/2。 结论 上海市肠炎沙门菌腹泻病例存在社区内获得和食源性感染等不同因素,肠炎沙门菌多重耐药型ACSSuT可能是潜在的高致病性流行株。提高临床实验室常规诊断能力,优化和减少老年人和婴幼儿对抗生素暴露,重视多重耐药菌株导致的疾病负担。     

2006-2020年美国沙门菌跨州暴发案例分析

食源和宠物源沙门菌感染造成的疾病负担已成为美国重大公共卫生问题。 本文通过分析2006 — 2020年美国153件食源性沙门菌跨州暴发（SMSFBD）和34件宠物源沙门菌跨州暴发（SMSPBD）案例的病原血清型分布、疾病负担、食物归因和处置结果等指标,描述美国不同群体在不同社会经济发展阶段对加工食品消费特征的变化。 同时,观察到在新型冠状病毒肺炎疫情大流行期间,随着社交活动和食品采购频次的减少,导致被动降低了食源暴露风险;随着居家生活时间增加等一系列生活方式的改变,导致原本流行于2018年新型庭院养殖活禽,却于2020年引发美国暴发史上波及范围最广、病例数最多、菌型最复杂的SMSPBD。 该结果提示,其他国家和地区防控食源和宠物源沙门菌暴发,可借鉴发达国家跨部门主动监测的策略,建立和运行与其疾病流行特征、疾病预防控制能力以及经济社会发展水平相匹配的食品与养殖生态安全预警体系,以应对各种新型食源性和生态型的沙门菌病不断变化的挑战。     

1984-2016年福建省人源与食源性沙门菌血清分型和耐药特征研究

目的研究福建省人源和食源性沙门菌血清型和耐药特征。方法追溯1984 — 2016年福建省内临床、健康体检者和食源性沙门菌株，使用世界卫生组织推荐的沙门菌血清分型方法进行回顾性鉴定。 通过纸片扩散法测试菌株对10种抗生素的敏感性，使用χ2检验对结果进行分类统计。结果复核人源和食源沙门菌1 406株，覆盖17个血清群（患者源16个、健康者携带源9个、食源性8个），确认伤寒、甲型副伤寒和猪霍乱沙门菌为肠道外感染的侵袭性血清型，确认除伤寒、甲型副伤寒和乙型副伤寒以外的非伤寒/副伤寒沙门菌65个血清型（患者源49个、健康者携带源46个、食源性27个），数量较多的前5位血清型分别为鼠伤寒、肠炎、德比、斯坦利和韦太夫雷登，临床感染优势血清型分别为鼠伤寒、肠炎、斯坦利、猪霍乱和德比，经验证和比对确认人源中5个和食品源中3个血清型为国内首次分离菌型。 健康人携带和食源性沙门菌的血清群、血清型分布和耐药谱接近，多重耐药（MDR）率显著低于患者来源株（χ2＝191.675，P＜0.001），患者源沙门菌对环丙沙星和三代头孢耐药率均低于10%，MDR率较高，占51.00%。 甲型副伤寒和鼠伤寒、肠炎沙门菌分别为伤寒/副伤寒、非伤寒/副伤寒沙门菌中耐药率较高和MDR率高的血清型。结论福建省人源沙门菌较食源性沙门菌有更广泛的生物多样性，人源沙门菌耐药率高于食源性沙门菌。 建议加强对临床侵袭性感染病例和食品–环境–人群的整合行为生态传染病导致暴发疫情的防控。     

旺兹沃思沙门菌耐药分子流行病学特征研究

目的 研究旺兹沃思沙门菌的耐药分子流行病学特征. 方法 基于上海市网络实验室连续性监测腹泻病例和环境食品的旺兹沃思沙门菌进行抗生素耐药和脉冲场凝胶电泳(PFGE)分析. 结果 2005-2012年上海市网络实验室诊断临床病例分离沙门菌4553株,居前10位的20个血清型均为A~F群,旺兹沃思沙门菌在少见的非A~F群中居首位,5岁以下和60岁以上人群普遍易感,偶见血流感染重症病例.确认食源环境沙门菌1805株,前10位血清型明显比人源更具多样性,旺兹沃思沙门菌亦在少见型中居首位,多源自牛蛙、甲鱼和淡、海水养殖鱼介类.旺兹沃思沙门菌的人源和非人源株间的耐药性差异无统计学意义(P0.05).PFGE分5个克隆族:克隆族A为多重耐药克隆,疑似暴发的2株12重耐药MDR-ACSSuT-SH009型菌株和1株6重耐药的SH009型甲鱼源菌株100%同源;克隆族B、D、E和C分别是成年人和低年龄组感染克隆,均对抗生素敏感. 结论 旺兹沃思沙门菌虽属相对少见菌型,近年病例数呈上升趋势.上海市近期分离的旺兹沃思沙门菌与牛蛙、甲鱼和淡、海水养殖鱼介类菌株存在高度相似性,建议对致病且多重耐药克隆加强监测,并预警餐饮机构在操作牛蛙和甲鱼时可能存在交叉污染或接触感染的暴露风险.     

源于东南亚的韦太夫雷登沙门菌在全球的传播扩散

韦太夫雷登沙门菌源于印度, 是典型的人畜共患病, 依靠特殊共生能力成为南亚和东南亚区域腹泻患者、水禽、海鲜中首位非伤寒沙门菌, 以人流(旅游)、物流(食品贸易)和洋流(海鲜)持续扩散至其他国家, 目前已定殖于国内养殖海水贝壳类和禽类中, 流行于华南地区:首次在国内规模化养殖鸡场发现韦太夫雷登多重耐药的优势克隆(MDR-ACSSuT), 而人源的耐药株罕见;首次在国内发现部分血液感染病例的暴发。韦太夫雷登已融入中国的养殖贝壳和禽类产品的产业链和食物链中, 具有全球生态扩展能力。中国近来的暴发有增多趋势, 发达国家在预防和处置食源性病原的污染、输入和暴发调查的制度和经验值得借鉴。     

2007年重庆市沙门菌监测分析

目的掌握沙门菌在腹泻病例中的感染率、沙门菌菌型种类及分布特征、药物耐药特征。方法确定监测病例定义及监测点,监测就诊和腹泻病暴发疫情中腹泻病例的沙门菌血清型别,并进行PFGE和耐药实验。结果2007年重庆市腹泻病例中沙门菌的感染率为8.74%,发现10个血清型的沙门菌,主要以汤普逊和鼠伤寒为主,秋季是发病高峰。沙门菌导致了10起腹泻病暴发,发生地点主要在居民家中或社区聚餐,鼠伤寒沙门菌是主要的致病菌,皮蛋是主要的危险食物。5种血清型的87株沙门菌做PFGE分析,鼠伤寒与汤卜逊沙门菌分别有3个基因型,婴儿、B群只有1种基因型。10个血清型的沙门菌分别对7种抗菌素出现耐药。结论沙门菌是导致腹泻疫情的主要致病菌之一,加强皮蛋的监测是降低发病的重要干预措施之一。     

2007年重庆市人群沙门菌监测分析

目的对重庆市人群沙门菌感染进行监测并对监测分离的菌株进行耐药性和脉冲场凝胶电泳（PFGE）分子分型研究。方法明确监测病例定义,制定、实施监测方案,实验室分离、鉴定监测的沙门菌,利用K-B法对分离菌株进行药敏检测,并采用PFGE进行分子分型。结果2007年监测了835例病例,病例分布在9个区(县),其中监测沙门菌暴发疫情10起,病例175例。实验室共分离鉴定了79株12种沙门菌（11种血清型和1组B群）,全部菌株对至少一种抗菌素耐药, 9种（75%）对3种以上的抗菌素耐药,2种（16.67%）对6种抗菌素耐药,尤其是里定沙门菌、婴儿沙门菌及汤卜逊沙门菌耐药严重。沙门菌PFGE分型被分成9种14种亚型。结论重庆市2007年人群沙门菌分离株没有明显的优势流行株,同一事件中的沙门菌PFGE分型相同,分离株耐药情况严重,分离菌株的耐药谱和PFGE型也没有明显的联系。     

2003-2014年浙江省宁波市肠炎沙门菌分子分型及耐药特征研究

目的 分析浙江省宁波市2003-2014年肠炎沙门菌脉冲场凝胶电泳（PFGE）分型及耐药特征。方法 采用PulseNet China网络实验室的标准方法,对2003-2014年间分离的68株肠炎沙门菌进行Xba Ⅰ和Bln Ⅰ酶切分型,使用BioNumerics软件对菌株的PFGE图谱进行聚类分析;使用纸片扩散法检测菌株对10种抗生素的耐药性。结果 68株肠炎沙门菌经Xba Ⅰ酶切分为8个PFGE带型。其中JEGX01.NB0001型为最优势型别,共53株,带型相似度90%以上的菌株占95.6%（65/68）,2003年和2013年超过80例以上的食源性暴发案例的肠炎菌株经双酶切聚类证实存在100%的同源性。所有肠炎沙门菌对抗生素耐药率为氨苄西林23.5%、强力霉素4.4%、氨曲南、头孢吡肟和头孢噻肟均为2.9%、氯霉素和复方新诺明均为1.5%,对庆大霉素、环丙沙星、亚胺培南均敏感,发现2株多重耐药菌。结论 宁波市散发和暴发的肠炎沙门菌分离株之间的分子带型差异度小,引发食源性暴发的流行株克隆之间存在流行病学关联。目前肠炎沙门菌对抗生素的耐药率处于较低水平,仍需加强对多重耐药株的监控。     

Microbial resistance: lessons from the EPIC study. European Prevalence of Infection

In 1992, a one day point prevalence study (EPIC) was conducted in European intensive care units (ICUs) to determine the prevalence of nosocomial infection among ICU patients. Of the 10,038 patients included, 45% were infected and 21% had a nosocomial ICU-acquired infection. Many of the organisms responsible for these infections were resistant to commonly used antibiotics. For example, 60% of the Staphylococcus aureus isolated were resistant to methicillin and 46% of Pseudomonas aeruginosa were resistant to gentamicin. The incidence of nosocomial infection varied between countries as did the incidence of antibiotic resistance. Mortality rates were higher in countries with higher rates of nosocomial infection and higher again in those countries with higher rates of resistant organisms. Antibiotic resistance is rising and clearly efforts to contain its development and spread are vital. Basic infection control procedures such as hand-washing must be developed and implemented, and antibiotic prescribing needs to be rationalized. The international variations in resistance rates, even within Europe, highlight the importance of being familiar with local resistance patterns when prescribing. The assistance of an infectious diseases specialist can be invaluable in providing a global overview of the local microbial milieu and of antibiotic resistance patterns. Epidemiological studies of this sort can provide useful information which can be used to stimulate debate on the reasons behind regional differences in infection and help in the development of strategies to combat the rising tide of microbial antibiotic resistance.     

Microbial resistance: lessons from the EPIC study

In 1992, a one day point prevalence study (EPIC) was conducted in European intensive care units (ICUs) to determine the prevalence of nosocomial infection among ICU patients. Of the 10,038 patients included, 45 % were infected and 21 % had a nosocomial ICU-acquired infection. Many of the organisms responsible for these infections were resistant to commonly used antibiotics. For example, 60 % of the Staphylococcus aureus isolated were resistant to methicillin and 46 % of Pseudomonas aeruginosa were resistant to gentamicin. The incidence of nosocomial infection varied between countries as did the incidence of antibiotic resistance. Mortality rates were higher in countries with higher rates of nosocomial infection and higher again in those countries with higher rates of resistant organisms. Antibiotic resistance is rising and clearly efforts to contain its development and spread are vital. Basic infection control procedures such as hand-washing must be developed and implemented, and antibiotic prescribing needs to be rationalized. The international variations in resistance rates, even within Europe, highlight the importance of being familiar with local resistance patterns when prescribing. The assistance of an infectious diseases specialist can be invaluable in providing a global overview of the local microbial milieu and of antibiotic resistance patterns. Epidemiological studies of this sort can provide useful information which can be used to stimulate debate on the reasons behind regional differences in infection and help in the development of strategies to combat the rising tide of microbial antibiotic resistance.     

Increasing ceftriaxone resistance in Salmonella isolates from a university hospital in Taiwan

OBJECTIVES: Salmonella infection is a distressing health problem worldwide. This study reports the changing epidemiology of Salmonella infections in Taiwan during 1999-2003, with emphasis on increasing ceftriaxone resistance. METHODS: Records of Salmonella clinical isolates in Chang Gung Memorial Hospital during 1999-2003 were reviewed. All isolates were identified and antimicrobial susceptibility determined by standard methods. A total of 22 ceftriaxone-resistant isolates were investigated by PCR sequencing of the bla(TEM), bla(SHV), bla(CTX-M) and ampC genes. Southern-blot hybridization was used to localize the ampC gene. Infrequent-restriction-site PCR was used to genotype these isolates. RESULTS: A total of 3635 Salmonella isolates, including 3592 (98.8%) non-typhoid Salmonella, were identified. Serogroup B (55.6%) remained the most predominant, but the prevalence has been decreasing. In contrast, serogroup D infections have increased significantly from 13.6 to 22.8%. Overall resistance to ampicillin and chloramphenicol remained high, with the highest rate (91% to both drugs) observed in Salmonella enterica serotype Choleraesuis in 2003. A sudden upsurge of ciprofloxacin resistance from zero to 69% was found in S. Choleraesuis. Ceftriaxone resistance increased in several serogroups (0.8-2.1%; average, 1.5%). The resistance was associated with plasmid-mediated bla(CMY-2) in 14 cases and extended-spectrum beta-lactamases (ESBLs), including CTX-M-3 (n=6), SHV-2a (n=1) and SHV-12 (n=1), in others. Diverse serotypes and genotypes were found among the ceftriaxone-resistant isolates. CONCLUSIONS: Increasing ceftriaxone resistance in non-typhoid Salmonella appears to link to the spread of plasmid-mediated ampC or ESBL genes. Effective measures should be taken to prevent the problem worsening.     

Methicillin-resistant Staphylococcus aureus in critical care areas

In recent years the mainstay of treatment for hospital-associated MRSA infections has been vancomycin, but now vancomycin intermediate S aureus strains are beginning to emerge. Complete vancomycin resistant S aureus can develop, possessing the same vanA gene as vancomycin-resistant enterococcus. Four such isolates have been reported, three of which have been in the United States. There are new antibiotics being developed, but there is always a risk of resistance developing. There are some promising new ideas such as staphylococcal conjugate vaccines that reduce the rates of S aureus bacteremia for up to 10 months postimmunization in patients who have end stage renal disease receiving hemodialysis, but studies are ongoing. With all the uncertainty surrounding treatment, at least one medium has remained consistent and effective if used properly--infection control. But this requires complete support of all healthcare workers and hospital administration from the chief medical officer to doctors and nurses to environmental services personnel to take ownership of an effective infection control program. Who will advocate for more stringent infection control policies and for the equipment to successfully carry them out? Who will take the lead by ensuring implementation of infection control policies on a unit is effective? Who will hold themselves and other health care workers including physicians accountable to comply with these infection control policies every time they enter a patient's room? Nurses are on the front lines in the battle against antibiotic-resistant nosocomial infections such as MRSA, and we should not be apathetic or feel we are helpless. It is our duty as patient advocates not to take a spectator role but to answer these questions: "I will."     

Large Drug Resistance Virulence Plasmids of Clinical Isolates of Salmonella enterica Serovar Choleraesuis

Salmonella enterica serovar Choleraesuis generally causes systemic human salmonellosis without diarrhea, and therefore, antimicrobial treatment is essential for such patients. The drug resistance information on this organism is thus of high value. Serovar Choleraesuis usually harbors a virulence plasmid (pSCV) of 50 kb in size. Of the 16 clinical isolates identified to be serovar Choleraesuis, all except one harbored a pSCV and seven of them carried a pSCV of more than 125 kb in size. A pSCV was defined as a plasmid carrying spvC and characteristic deletions detected by PCR and by DNA-DNA hybridization (for the former criterion). The results of PCR, restriction fragment profiles, and Southern DNA-DNA hybridizations of the profiles all indicated that such larger pSCVs were derived from the 50-kb plasmid recombined with non-pSCVs found in some clinical isolates. Fifteen of the 17 strains, including a laboratory strain, were then tested for drug resistance against 16 antibiotics with E-test and the dilution method. The laboratory strain, which harbored a 50-kb pSCV and a 6-kb non-pSCV, was resistant only to sulfonamides (SUL), and its resistance gene, sulII, checked with PCR and DNA-DNA hybridization, was located on the 6-kb non-pSCV. All 14 clinical strains were resistant to multiple drugs. Of the 14, 7 were resistant to SUL, and the resistance gene was located on a plasmid. The sulII gene, but not bla(TEM-1), was carried only on the 6-kb non-pSCV. Of the remaining six large plasmids, three of 90 kb, two of 136 kb, and one of 140 kb, the last three were pSCVs and carried the other SUL gene (sulI) and the bla(TEM-1) gene. The six strains were also resistant to trimethoprim-sulfamethoxazole. None of the 50-kb pSCVs carried resistance genes. These drug resistance genes on the large pSCVs were apparently also acquired through recombination.     

Fighting infection: an ongoing challenge, part 1

Since the beginning of time, infections have been a major cause of disability and death of humans in every part of the world. For centuries, little was known about what caused infection, how to prevent infection, or how to cure infection. With the discovery of sulfa and penicillin in the 1930s, the ability to fight infection became reality. During the next six decades, antimicrobials were developed to fight bacterial, fungal, and viral infections. It truly seemed as if the battle against infection was won, until the rapid and global spread of drug resistance began to threaten the effectiveness of all currently available antimicrobials. A new phase of the war against infection began, and the search for methods of reducing the spread of drug resistance began. Today, it is apparent that identifying the agents of infection, understanding how antimicrobials are targeted against specific infectious organisms, and practicing the judicious application of antimicrobials will help reduce the threat of continued escalation of antimicrobial resistance. Part 1 of this three-part series will provide an overview of how antimicrobials are designed to target specific agents of infection and how drug resistance develops. Parts 2 and 3 will examine individual antibacterial, antifungal, and antiviral agents and the recommendations for their appropriate use.     

传染病医院ICU住院患者发生医院感染的病原菌分布及耐药性分析

目的：研究传染病医院重症监护病房（ICU）住院患者医院感染的病原菌分布及耐药性。方法回顾性分析2012年6月至2014年1月武汉市医疗救治中心接诊发生医院感染的50例ICU住院患者的临床资料,分析构成的病原菌及耐药性。结果革兰阴性菌、革兰阳性菌和真菌各占检出菌株的33．33％,三者相比差异无统计学意义（χ2=0．0000,P=1．0000）。革兰阴性菌感染中以鲍曼不动杆菌最多,占16．67％;革兰阳性菌感染中以金黄色葡萄球菌最多,占11．90％;真菌感染中以白色假单胞菌最多,占21．43％。感染部位以下呼吸道的感染最多见,占78．0％;与其他部位感染率相比,差异有统计学意义（P＜0．05）。分离的病原菌大多数有一定的耐药性,并且多重耐药的趋势明显增加。结论传染病医院ICU住院患者感染主要发生于呼吸道,革兰阴性菌居多且耐药严重。     

Macrolide resistance in Campylobacter jejuni and Campylobacter coli

Infection with Campylobacter jejuni is now considered to be the most common cause of acute bacterial gastroenteritis in humans worldwide. It occurs more frequently than infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7. Although C. jejuni is also recognized for its association with serious post-infection neurological complications, most patients with C. jejuni infections have a self-limited illness. Nevertheless, a substantial proportion of these infections are treated with antibiotics. These include severe and prolonged cases of enteritis, infections in immune-suppressed patients, septicaemia and other extra-intestinal infections. Under these circumstances, erythromycin is often recommended as the drug of first choice. However, erythromycin-resistant Campylobacter have emerged during therapy with macrolides. Moreover, the widespread use of macrolides, including erythromycin, in veterinary medicine has accelerated this resistance trend. Several countries including Canada, Japan and Finland have reported C. jejuni isolates with low and stable rates of macrolide resistance. In contrast, the increasing level of macrolide resistance in C. jejuni is becoming a major public health concern in other parts of the world such as the United States, Europe and Taiwan. Macrolide resistance in Campylobacter is mainly associated with point mutation(s) occurring in the peptidyl-encoding region in domain V of the 23S rRNA gene, the target of macrolides. Several rapid and practical techniques have recently been developed for the identification of macrolide-resistant isolates of C. jejuni. The aim of this mini-review is to give an overview of the worldwide distribution of macrolide resistance in C. jejuni and Campylobacter coli as well as its possible association with the massive use of these agents in food animals. Mechanisms implicated in macrolide resistance in C. jejuni and also techniques that have been developed for the efficient detection of macrolide-associated mutation(s) will be discussed in detail.