福氏志贺菌对诺氟沙星耐药性及耐药机制的研究

目的研究福氏志贺菌对诺氟沙星的耐药性及耐药机制。方法收集福氏志贺菌３０株,进行抗菌药物敏感试验,４株耐药菌,１株敏感菌和福氏志贺菌标准菌５１５７３的ｇｙｒＡ基因的Ｎ末端编码区进行ＰＣＲ扩增并克隆和测序。结果福氏志贺菌对诺氟沙星的耐药率高达５３．３％,ｇｙｒＡ基因的序列分析结果揭示存在３个导致氨基酸改变的基因点突变：丝氨酸８３→亮氨酸,天冬氨酸８７→天冬酰氨,天冬氨酸８７→甘氨酸。结论福氏志贺菌对诺氟沙星已有较高的耐药性,ｇｙｒＡ基因点突变与福氏志贺菌对诺氟沙星的耐药性有关。     

志贺菌属对氟喹诺酮类药物耐药机制的研究

目的 研究志贺菌属对氟喹诺酮类药物的耐药机制。方法 从临床上收集志贺菌１５７株,进行药敏试验、利血平逆转试验、Ｒ质粒接合试验和细菌内诺氟沙星聚积的测定。对其中８株耐药菌、１株敏感菌和１株福氏标准菌的基因５＾１－末端编码区进行聚合酶链瓜 增并克隆和序列分析。结果 诺沙星耐药菌的Ｒ质粒接合试验阳性率为５１．２％,Ｒ质粒不能传递对氟喹诺酮类药物的耐药物,利血有降低氟喹诺酮类药物对志贺菌的最低抑菌浓度值,     

上海市沙门菌和志贺菌腹泻型谱和耐药特征的分析

目的通过对沙门菌和志贺菌致泻血清型和耐药性研究了解菌型特征及耐药谱。方法收集和鉴定了115株沙门菌和644株志贺菌；以K—B法测试沙门菌和志贺菌对16种抗生素的耐药率，使用E-test定量法确认产超广谱β-内酰酶（ESBLs）菌株。结果肠炎沙门菌、鼠伤寒沙门菌和福氏志贺菌4c亚型（F4c）、宋内、福氏志贺菌2b亚型（F2b）分别是造成腹泻的优势血清型；比较2年中沙门菌的耐药率有上升趋势，耐四环素-萘啶酸-复方新诺明的R1型志贺菌比例高达79．91％．产ESBLs的分别有1株肠炎沙门菌、44株福氏志贺菌、11株宋内志贺菌。结论试管凝集效价是诊断不典型志贺菌型特异性抗原的定量依据．用E-test法判定的产ESBLs沙门和志贺菌符合复燃的新型肠道病原菌定义，志贺菌的耐药型谱对肠道门诊选用抗菌药物具有重要参考价值。     

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目的研究解放军302医院2003-2004年痢疾杆菌菌群分布和药敏特点,指导临床治疗。方法经粪培养筛选出254株痢疾杆菌,用生化和血清学方法鉴定群和血清型。采用Kirby-Bauer法检测病原耐药性。结果在254株痢疾杆菌中,福氏志贺菌最多有196株,宋内志贺菌有58株。在福氏志贺菌血清型中,F4占首位,有106株。总的药敏结果耐药率复方新诺明最高,氨苄青霉素次之;对氟喹诺酮类抗生素耐药性较高,三代头孢菌素、磷霉素耐药率低。结论2003-2004年解放军302医院细菌性痢疾患者中,菌群以福氏志贺菌占优势,血清型以F4为主。氟喹诺酮类抗生素仍是最有效的抗生素之一,但有一定耐药性。若氟喹诺酮类抗生素无效,可选用三代头孢菌素或磷霉素。     

氟哌酸和黄连素对志贺氏菌耐药性质粒消除研究

用氟哌酸和黄连素对２０株携有接合传递耐药性质粒（Ｒ质粒）及１９株携有非接合传递耐药性质粒（ｒ质粒）志贺氏菌进行体外消除研究。结果显示，可被消除的耐药性质粒大多数在２４小时内被消除。氟哌酸对Ｒ质粒及ｒ质粒消除率分别为５％和５２．６％，黄连素对Ｒ质粒及ｒ质粒消除率分别为１０％和５７．９％，两种药物对ｒ质粒消除率明显优于对Ｒ质粒消除率，其原因可能与ｒ质粒分子量小，非传递性及在药物作用下易于丢失有关。氟哌酸和黄连素均为广谱抗菌药物，因此在临床上治疗感染的同时又能消除耐药性质粒，阻止耐性扩散。     

细菌性痢疾流行特点及志贺菌耐药性研究

目的研究近年来肠道门诊细菌性痢疾流行概况及志贺菌耐药特点,为细菌性痢疾临床治疗和预防控制提供依据。方法采用志贺菌及沙门菌琼脂培养基培养,可疑菌株经VITEK-32细菌鉴定仪及血清凝集鉴定到群,K-B法检测抗菌药物的耐药性,纸片确认试验检测产超广谱β-内酰胺酶（ESBLs）,三维试验检测AmpCβ-内酰胺酶（AmpC酶）。结果 279例细菌性痢疾感染患者主要以宋内志贺菌（201株,占72.4%）和福氏志贺菌（76株,占27.2%）感染为主,且患者主要集中在0～11岁年龄段,占总感染率的71.3%（199/279）,高发季节为7-11月。药敏结果显示,志贺菌对氨苄西林、哌拉西林和复方新诺明的耐药率较高,均〉60%;对环丙沙星和左旋氧氟沙星的耐药率较低,均〈40%,未发现耐哌拉西林/他唑巴坦和亚胺培南的志贺菌。151株志贺菌纸片确认试验为产ESBLs阳性菌株,占54.1%（151/279）;未发现AmpC酶阳性者。结论我院肠道门诊细菌性痢疾以感染宋内志贺菌和福氏志贺菌的婴幼儿为主,且宋内志贺菌有增高趋势,2种志贺菌对部分种类的抗菌药物药敏性差别较大,临床医师应根据菌群鉴定及药物敏感试验结果合理选择抗菌药物。     

天津地区志贺菌属产超广谱β内酰胺酶及其基因型的检测

目的 了解天津地区志贺菌属产超广谱β内酰胺酶(ESBL)的流行基因型、耐药特征和流行病学特征,探讨产ESBL志贺菌属特性与耐药质粒的关系.方法 136株志贺菌来源于2009年5月至2010年9月在天津市儿童医院、天津医科大学第二医院及天津市第一中心医院门诊就诊的以脓血便为主的腹泻患者粪便标本,纸片扩散法筛选可疑产ESBL志贺菌属;对产ESBL志贺菌进行接合试验,供体菌和接合子进行耐药性测定,以确定耐药性质粒传递;采用TEM、SHV、CTX-M-1组、CTX-M-2组、CTX-M'9组β内酰胺酶通用引物对产ESBL菌株的基因型进行PCR检测.使用肠杆菌科基因间的重复序列PCR(ERIC-PCR)分析产ESBL菌株的分子同源性.采用x2检验.结果 136株志贺菌属中,产ESBL志贺菌20株,检出率为14.7％,未检测出产AmpC酶菌株.其中16株志贺菌基因型为CTX-M-14型,4株为CTX-M-15型;产CTX-M型ESBL菌株对多种抗菌药物耐药,但对亚胺培南的敏感率为100％.18株产ESBL志贺菌接合试验获得成功,其接合子对β内酰胺类抗菌药物耐药.结论 天津地区志贺菌属产ESBL基因型以CTX-M型为主,产ESBL是志贺菌属对β内酰胺类耐药的主要原因,产ESBL菌株的传播机制以质粒介导为主.     

广西宋内志贺菌药敏特性及ESBLs基因检测分析

目的了解广西地区宋内志贺菌的药敏特性及携带超广谱β-内酰胺酶(ESBLs)基因与型别特征,为临床合理用药和控制耐药性的传播提供科学依据。方法采用微量肉汤稀释法对宋内志贺菌分离株进行药物敏感试验;采用PCR方法和毛细管电泳方法检测菌株携带相关ESBLs基因;采用近邻相接法构建系统进化树,分析菌株CTX-M型基因型别;对菌株携带ESBLs基因与特定抗菌药物耐药性的关系进行统计学分析。结果90株宋内志贺菌对环丙沙星敏感率为86.67%,无耐药现象;头孢曲松耐药率为96.67%,阿奇霉素耐药率为96.67%,多重耐药率为98.89%。90株宋内志贺菌中50株检出blaCTX-M-9 group基因,检出率为55.56%,经系统发育分析均为CTX-M-14亚型;1株检出blaTEM基因,检出率为1.11%;未检出blaCTX-M-1 group,blaCTX-M-2 group,blaCTX-M-8 group,blaCTX-M-25 group和blaOXA,blaSHV,blaNDM,blaVIM等β-内酰胺酶基因。blaCTX-M-14基因阳性菌株与blaCTX-M-14基因阴性菌株对头孢噻肟的耐药率差异无统计学意义(χ²=0.000,P>0.05);携带blaTEM基因的菌株对头孢他啶不耐药。结论广西地区的宋内志贺菌对主要治疗药物头孢曲松高度耐药,且多重耐药现象严重;菌株普遍携带ESBLs基因,主要为CTX-M-14亚型;携带单一型别的ESBLs基因与菌株对特定β-内酰胺类抗菌药物耐药无明显关联。     

1831株宋内志贺菌耐药性调查及其产ESBLs的研究

目的了解分离自腹泻患者的1831株宋内志贺菌的流行趋势及耐药情况,探讨宋内志贺菌多重耐药机制。方法采用志贺菌及沙门菌琼脂培养基培养及K—B法检测14种抗生素的耐药率。多重耐药菌用纸片确认试验检测产超广谱β内酰胺酶（extended-spectrum β-laetamases,ESBLs）,改良三维试验检测ESBLs和AmpC β内酰胺酶（AmpC β-lactamase,AmIpC酶）。结果1831株宋内志贺菌感染腹泻患者中,男女比例为1．25：1。高发季节为7～9月。1～20岁发病人数占总发病人数的71．0％。宋内志贺菌对复方磺胺甲嗯唑、氨苄西林和头孢曲松的耐药率较高,分别达87．7％、23．0％和9．5％,且增高趋势明显;对氟喹诺酮类,头孢吡肟、头孢美唑、氯霉素、磷霉素和庆大霉素的耐药率较低,明显低于头孢曲松、头孢噻肟（P〈0．05）。43株多重耐药菌均为ESBLs阳性株,未发现产AmpC酶株。结论在北京地区,宋内志贺菌感染腹泻患者发病年龄以青少年为主。其存志贺菌属感染的比例中有增高的趋势,对头孢曲松、头孢噻肟、复方磺胺甲嗯唑、氨苄西林的耐药率较高且有上升趋势。宋内志贺菌耐头孢菌素者以产ESBLs为主。     

北京地区1994-2005年腹泻病原菌的分布及其耐药趋势

目的 监测我院1994-2005年与腹泻有关的肠道致病菌的分布及耐药趋势,为本地区流行病学研究、疫苗制备及临床合理用药提供依据.方法 通过常规大便培养,筛出致病菌后经生化及血清学进一步鉴定到种、群或血清型,并以纸片扩散法测定抗菌药物的敏感性.结果 12年分离到肠道病原菌8426株,患者以男性为主,儿童和青年发病为多,每年7～9月为腹泻发病高峰.病原以志贺菌属居首位(占75.11%),其次是弧菌(占12.70%),再依次为沙门菌属、气单胞菌、致病及侵袭大肠埃希菌分别占6.28%、4.43%及1.25%.6329株志贺菌中,福氏志贺菌占75.62%,其次是宋内菌群(23.98%),痢疾志贺菌及鲍氏志贺菌分别占0.22%及0.01%.12年的变化趋势是,每年肠道病原菌总数在逐渐减少,特别是志贺菌、沙门菌减少明显,而弧菌及气单胞菌相对逐渐增多.各菌属及不同的血清型对抗菌药物的敏感率有差异,福氏志贺菌和气单胞菌属多重耐药较多,而宋内志贺菌和弧菌属对多数抗菌药物敏感.结论 北京地区感染性腹泻的病原种类多,随时间的变迁病原变化明显,耐药性不同,应重视监测.     

Antimicrobial resistance trends of shigellae isolates from Calabar, Nigeria.

During a 3-year study (January 1986-December 1988), stools of 2200 diarrhoeal or dysenteric patients were examined by culturing and 108 (4.9%) were found positive for shigellae. Shigella flexneri was the commonest species isolated (54.6%), followed by Sh. dysenteriae (24.1%). Patients aged less than or equal to 15 years accounted for 51.4% of cases. Shigellae over the 3 years showed high and sometimes rising resistance to ampicillin, chloramphenicol, streptomycin and cotrimoxazole and complete resistance to tetracyclines and sulphonamides. Sh. sonnei strains isolated in 1986 and 1987 were almost invariably sensitive to all antimicrobial agents except ampicillin, while in 1988 strains were resistant to all. The isolation rate was higher (74.1%) during the dry season than in the rainy season (25.9%) (P less than 0.01). Low standards of community and personal hygiene and improper sewage disposal are the prevailing epidemiological factors identified.     

A study on transferable R-plasmids among Shigella species at Lucknow

A total of 500 Shigella strains were included in the present study out of which 233 were isolated at National Shigella Centre of Postgraduate Department of Microbiology, K.G. Medical College, Lucknow during last 5 years and 267 strains were received from different parts of the country. Predominent serotypes were Sheigella flexneri 292 (48.4%) followed by Shigella dysenteriae 153 (30.6%), Shigella boydii 32 (6.4%) and Shigella sonnei 23 (4.6%). All the strains were sensitive to Nalidix acid, Gentamycin, Kanamycin, Neomycin and Furazolidine. Varying degree of resistance was shown to Streptomycin, Chloramphenicol, Tetracycline and Ampicillin. R. plasmid extraction was done and transfer was studied on E. Coli K-12.     

淋病流行株耐药性及耐药基因的定位分析

目的 了解淋病流行株的耐药性，并对其耐药基因进行定位分析。方法 2000～2001年从广东省湛江地区分离到98株淋病流行株，采用K-B法测定淋球菌对10种抗生素的敏感性，应用碱裂解法提取相应菌株的质粒，选择NG4、NG31、NG43、NG70菌株作质粒的接合及消除试验，对耐药基因进行定位。结果 98株淋病流行株对环丙沙星、四环素、氯霉素耐药率分别为82．65％、69．39％、50．00％；质粒总检出率为91．84％，42．5kb、39．5kb、7．4kb、4．2kb质粒分别占11.22％、41.82％、59．16％、67．32％。NG31、NG43能通过接合将对四环素和氯霉素的耐药性传递给受体菌，而通过质粒消除又可恢复对抗生素的敏感性；环丙沙星的耐药性通过接合及消除未见改变。结论 湛江地区淋病流行株耐药形势严峻，耐药基因定位显示，淋球菌对四环素和氯霉素的耐药由质粒介导，对环丙沙星的耐药则由染色体介导。     

Species and serovar distribution, and drug resistance of Shigella strains isolated from imported and domestic cases in 1980-1989 in Tokyo

A total of 1,189 Shigella strains consisting 804 imported and 385 domestic strains were examined for their species and serovar distribution, and their drug-resistance. In both imported and domestic strains, S. sonnei was found to be the most prevalent species, followed by S. flexneri, S. boydii and S. dysenteriae in order. In imported strains, however, the isolation frequency of S. flexneri, S. boydii and S. dysenteriae were higher than that of domestic strains, and the serovar of each species was distributed in a wider range than that of the domestic strains. The drug resistance test using chloramphenicol (CP), tetracycline (TC), streptomycin (SM), kanamycin (KM), ampicillin (ABPC), sulfamethoxazole-trimethoprim (ST), nalidixic acid (NA), fosfomycin (FOM) and norfloxacin (NFLX) showed that 80.1% of the imported strains and 82.9% of the domestic strains were resistant to any of drugs examined, although frequency of resistance varied by their species. The frequency of resistance to each drugs were SM (74.0%), TC (68.5%), CP (38.8%), ABPC (35.3%), ST (34.1%), NA (1.5%) and KM (1.0%) in imported strains, and TC (79.2%), SM (55.3%), ABPC (40.3%), CP (38.4%), ST (32.4%), NA (30.5%) and KM (4.2%) in domestic strains. No strain resistant to FOM or NFLX was found in both groups. The resistance patterns varied to 32 types. Among those, a multiple drug-resistance type with CP.TC.SM.ABPC was found most frequently in both groups. Frequency of strains carrying transferable R plasmid was tested for 50 strains isolated in 1989 and three (6%) of them had the plasmid.     

Antimicrobial resistance in Shigella species isolated in Dakar, Senegal (2004-2006)

From May 2004 to October 2006, a prospective study was carried out in Dakar, Senegal, to update information about the antimicrobial susceptibility of Shigella spp. isolated from stool specimens. Among the 165 non-duplicate strains collected, 81 (49%) were identified as Shigella flexneri, 75 (45%) as Shigella sonnei, 5 (3%) as Shigella boydii, and 4 (2%) as Shigella dysenteriae. Disk diffusion testing revealed that the majority of isolates were resistant to sulphonamides, trimethoprim-sulfamethoxazole, streptomycin, and tetracycline (respective overall resistance rates: 90, 90, 96, and 94%). More than half of the S. flexneri isolates were resistant to amoxicillin, amoxicillin-clavulanic acid, and chloramphenicol (respective resistance rates: 59, 58, and 52%), and almost all of the S. sonnei isolates were susceptible to these antimicrobials (respective resistance rates: 4, 1, and 4%). Only one isolate (belonging to the species S. sonnei) was resistant to nalidixic acid and displayed reduced susceptibility to ciprofloxacin.