广州地区106株淋球菌中脂蛋白分型与环丙沙星耐药相关性研究

目的:研究广州地区106株淋球菌中脂蛋白分型与环丙沙星耐药的相关性.方法:用糖琼脂稀释法测定淋球菌对环丙沙星的MIC值,PCR分别扩增淋球菌的gyrA、parC和脂蛋白基因并测序分析.结果:广州地区106株淋球菌对环丙沙星的耐药率为95 3%,共有19个脂蛋白亚型,最常见的亚型是17c,有49株(46 2%).对环丙沙...     

广州淋球菌基因特征及其多抗原序列分型与环丙沙星耐药相关性研究

目的 探讨2014年广州市97株淋球菌环丙沙星耐药株的基因特征及其多抗原序列分型（NG-MAST）与淋球菌耐环丙沙星的相关性。 方法 用琼脂稀释法测定淋球菌对环丙沙星的最低抑菌浓度（MIC）,PCR分别扩增淋球菌的gyrA、parC基因和NG-MAST分型基因porB、tbpB基因并测序,获取耐药菌株的ST型别。 结果 97株淋球菌中95株（97.9%）对环丙沙星耐药。95株环丙沙星耐药菌株均在gyrA基因对应丝氨酸的第91和95位点上发生了突变,其中93株菌出现了parC基因突变。41株高水平耐药株（MIC ≥ 16 mg/L）中35株（85.4%）出现了parC基因87位点突变,54株低水平耐药株中32株（59.3%）出现此突变,差异有统计学意义（χ2 = 7.64,P < 0.05）。96株淋球菌分离株配对后,50株为网站已编号型别,共35个不同的ST型,其中10个ST型含有2 ~ 4个不同的分离株,ST型别中最常见ST5309。对淋球菌菌株系统进化树分析,淋球菌流行株可分为两群,第1群84株中MIC ≥ 16 mg/L的菌株39株占46.4%,第2群12株中只有1株MIC值为16 mg/L,差异有统计学意义（χ2 = 6.27,P = 0.012）。 结论 淋球菌对环丙沙星的高水平耐药主要与parC基因87位点突变相关。NG-MAST分型与环丙沙星耐药程度高低可能存在相关性。     

淋球菌gyrA和parC基因突变与氟喹诺酮类药物关系的研究

目的：探讨淋球菌gyrA和parC基因突变与淋球菌耐氟喹诺酮类药物之间的关系。方法：①纸片扩散法检测58株淋球菌对5种氟喹诺酮类药物的敏感性。②E测定法定量检测环丙沙星的最小抑菌浓度（MIC）。③PCR技术扩增gyrA和parC基因的喹诺酮耐药决定区（QRDR）相关序列并作测序分析。结果：①对环丙沙星、氧氟沙星、氟罗沙星、洛美沙星、依诺沙星同为敏感、中介、耐药者分别为2株、4株和39株。②环丙沙星MIC为敏感、中介、耐药分别为2株、17株和39株。③环丙沙星MIC为0．004－0．016μg/mL的2株淋球菌gyrA和parC基因均未发生突变；MIC为0．064－0．094μg/mL的菌株仅发生gyrA单位点突变；而MIC≥0.25μg/mL的菌株均发生gyrA双位点突变。MIC≤0．25μg/mL的菌株无parC基因突变，而MIC≥1.0μg/mL的菌株除出现gyrA双位点突变外均同时发生parC单位点突变。④在发生突变的16株菌中，Ser91(TCC)→Phe(TTC）突变为15株。结论：①gyrA基因突变介导淋球菌对氟喹诺酮类药物低和中水平耐药，而对氟喹诺酮类药物高水平耐药需要parC基因突变的共同参与。②gyrA基因Ser91→Phe的突变是导致淋球菌对氟喹诺酮类药物耐药的关键突变。     

解脲脲原体的耐药性分析及其耐氟喹诺酮的分子机制研究

目的检测128株临床分离解脲脲原体(UU)对9种药物的敏感性,并检测喹诺酮类耐药UU对5种喹诺酮药物的MIC以及gyrA和parC基因突变情况。方法应用支原体分离鉴定、计数药敏试剂盒检测UU对9种药物的敏感性,用微量肉汤稀释法检测耐药UU菌株对5种喹诺酮类药物的MIC,用PCR和DNA测序及序列比较检测基因突变。结果UU对多西环素最敏感,其次为米诺环素、交沙霉素、司帕沙星及克林霉素,对大环内酯类药物阿奇霉素和罗红霉素高度耐药。而司帕沙星、加替沙星和左氧氟沙星的MIC范围在0.25～8μg/mL,抑制UU活性强于氧氟沙星和环丙沙星。10株喹诺酮类耐药UU中有3株只有parC基因第80位TCA→TTA的突变,氨基酸由丝氨酸→亮氨酸,1株GyrA基因第95位密码子GAC→GAA的突变,氨基酸由天冬氨酸→谷氨酸。6株两者同时存在。结论在UU治疗中可首选多西环素,其次为米诺环素和交沙霉素。gyrA基因95位密码子和parC基因80位的突变密码子与UU耐喹诺酮类药物密切相关。     

体外诱导解脲脲原体对喹诺酮类药物交叉耐药的研究

目的 探讨经次抑菌浓度喹诺酮类药物多代培养后,解脲脲原体（Uu）敏感株对喹诺酮类药物敏感性的变化及其机制.方法 将3株Uu临床分离株及标准株Uu3在含有次抑菌浓度诺氟沙星、氟罗沙星、环丙沙星或左氧氟沙星的液体培养基中传代培养10-12代后,检测其对4种药物的MIC值.提取标准株及耐药株的DNA,PCR扩增喹诺酮耐药决定区的gyrA和parC基因,测序分析耐药株的基因突变情况.结果 经次抑菌浓度喹诺酮类药物多代培养诱导后,3株临床分离敏感株与Uu3均出现对诱导药物的耐药及交叉耐药,共诱导出16株药物诱导耐药株.在它们及9株临床分离耐药株中,parC基因未检出错义突变,但gyrA基因检出2种错义突变,即：V175A（n=8）和N165D（n=1）.结论 次抑菌浓度喹诺酮类药物可诱导解脲脲原体出现交叉耐药,其产生可能与gyrA基因突变有关.     

染色体介导淋球菌耐药机制的进展

染色体介导的与青霉素及与四环素耐药相关的主要位点包括penA、ponA、penB、penC、mtr及tet。青霉素结合蛋白中出现镶嵌状结构是头孢菌素低敏的原因之一。喹诺酮耐药决定区gyrA和parC不同的位点突变导致喹诺酮耐药。淋球菌对大观霉素高度耐药是由于spe位点单步突变所致。多重耐药与多种位点突变相关。     

淋球菌对大观霉素耐药基因的初步检测

【摘要】 目的 检测导致大观霉素耐药的淋球菌16S rRNA基因中的突变位点。 方法 对6株大观霉素耐药淋球菌［最小抑菌浓度（MIC） ≥ 128 mg/L］、20株大观霉素敏感菌株（MIC 32 mg/L和16 mg/L各10株）的16S rRNA基因进行DNA扩增和序列测定,分析16S rRNA基因突变情况。 结果 6株大观霉素耐药淋球菌的16S rRNA基因均发生了突变,其中2株（MIC > 256 mg/L）为C1192T突变,1株（MIC 256 mg/L）为C1344T和T1345A突变,1株（MIC 256 mg/L）为T990G和T991C突变,1株（MIC 128 mg/L）为T990G、G1343C和C1344T突变,1株（MIC 128 mg/L）为T991C突变。20株大观霉素敏感菌株均未发生突变。 结论 淋球菌16S rRNA基因不同位点突变可能与大观霉素不同程度的耐药相关,C1192T突变可能导致高度耐药,其他单一位点或多位点突变与不同程度的耐药相关。 【关键词】 奈瑟球菌,淋病; 壮观霉素; 点突变; RNA,核糖体,16S; 抗药性,细菌     

淋病奈瑟菌对氟喹诺酮的耐药性及GyrA耐药基因突变类型的研究

目的探讨江苏省淋病奈瑟菌(NG)对氟喹诺酮的耐药状况、耐药基因突变型的分布情况及二者之间的关系。方法采用琼脂稀释法检测江苏省三个地区临床分离的95株NG氟喹诺酮类药物的最小抑菌浓度(MIC),根据结果抽取部分菌株采用PCR法扩增gyrA基因的氟喹诺酮耐药决定区(QRDR),并进行测序分析。结果根据所测MIC,95株NG对环丙沙星100%的耐药;60株通过测序分析,检测到gyrA的五种突变形式,以gyrA出现272位碱基C→T和283位G→A的突变型的MIC最高。结论在江苏省,NG对氟喹诺酮耐药严重,氟喹诺酮药物已不再适合用于临床治疗淋病。     

广州地区淋球菌对环丙沙星的耐药性监测

目的：监测广州地区2000年-2003年分离的淋球菌对环丙沙星的耐药性，为制定淋病防治策略和修改淋病的治疗方案提供参考依据。方法：采用琼脂稀释法测定菌株对环丙沙星的最小抑菌浓度(MIC)，计算耐药百分率、MIC50、MIC90和MIC均。结果：从2000年-2003年共检测396株淋球菌，耐药菌344株，占86．7％。淋球菌对环丙沙星耐药率由2001年的73．7％上升到2003年的93．6％，呈稳步上升趋势。环丙沙星的MIC50、MIC90和MIC均4年间增加了1倍。结论：广州地区淋球菌对环丙沙星耐药率很高，且呈稳步上升趋势，环丙沙星不再适宜被推荐用于对淋病治疗的首选药物。     

广州地区淋球菌营养分型和抗生素耐药性的研究

为了解广州地区淋球菌的营养型分布和4种抗生素的耐药性,以广州地区167株淋球菌进行MIC测定和PPNG检测,同时对其中113株淋球菌进行营养分型检测。结果显示,167株菌中检出PPNG菌株9株,TRNG16株,青霉素耐药株109株（65.3%）,环丙沙星耐药株131株（78.4%）,大观霉素、头孢曲松未发现耐药株。113株淋球菌分16种营养型,以Pro^-型、Proto型、Pro^-、Ile^-、Ile^-型、Pro^-Ile^-Ser^-型5种营养型为主,占86.5%,其余11种营养型占13.5%。青霉素和环丙沙星的耐药菌株主要分布于Pro^-型中,TRNG菌株主要分布于Ile^-型,PPNG菌株散在于各种营养型中。研究结果表明广州地区淋球菌的营养型和耐药性的分布状况,有助于该地区淋球菌的流行病学研究和淋病防治。     

Multiclonal increase in ciprofloxacin-resistant Neisseria gonorrhoeae,Thailand, 1998-1999

BACKGROUND: isolates exhibiting clinically significant resistance to fluoroquinolones have been isolated most frequently in Asian and western Pacific countries, including Thailand. In Bangkok, Thailand, ciprofloxacin has been used to treat gonorrhea since 1987. GOAL: Our goal was to determine the prevalence of isolates of that exhibit resistance to ciprofloxacin in Bangkok and to characterize these strains with regard to ciprofloxacin MICs, auxotype/serovar (A/S) classification, A and C mutations responsible for ciprofloxacin resistance, and outer membrane lipoprotein (Lip) subtype analysis. STUDY DESIGN: MICs of gonococcal isolates from consecutive patients attending the Bangrak Hospital STD Clinic in Bangkok were determined by agar dilution. A/S class was determined by established procedures. Mutations within A and C were determined by DNA sequencing. Lip subtypes were determined by PCR and DNA sequencing. RESULTS: In 1998 and 1999, 115 of 168 isolated strains of exhibited decreased susceptibility or resistance to ciprofloxacin, and three cases of possible ciprofloxacin treatment failure were identified. Ciprofloxacin-resistant (CipR) strains increased from 13.8% (8/58) in 1998 to 25.4% (28/110) in 1999 ( = 0.08). Ciprofloxacin MICs of CipR isolates ranged from 1.0 microg/ml to 32.0 microg/ml. CipR strains belonged to a number of A/S classes and Lip subtypes. Different CipR strains contained alterations at both amino acid 91 and amino acid 95 of A and also contained an amino acid alteration in C. These alterations are known to be involved in gonococcal resistance to ciprofloxacin. CONCLUSIONS: The prevalence of CipR strains of isolated in Bangkok increased substantially in the 1990s. Characterization of the CipR isolates revealed a number of different strain subtypes, indicating that CipR isolates in Bangkok are not from a single clonal source and therefore result from multiple cases of importation or local emergence. Because of the high level of CipR isolates at Bangrak Hospital, in 2000 the Thai Ministry of Public Health issued recommendations against the use of fluoroquinolones for the treatment of gonococcal infection in Thailand.     

The epidemiology of ciprofloxacin resistant isolates of Neisseria gonorrhoeae in Scotland 2002: a comparison of phenotypic and genotypic analysis

OBJECTIVES: To characterise all isolates with reduced susceptibility or resistance to ciprofloxacin received by the Scottish Neisseria gonorrhoeae Reference Laboratory (SNGRL) in 2002 using N gonorrhoeae multi-antigen sequence typing (NG-MAST); to compare NG-MAST with conventional typing and to describe the epidemiology of ciprofloxacin resistant gonorrhoea in Scotland in 2002. METHODS: Isolates were characterised on receipt by auxotyping and serotyping (A/S typing), and antibiotic susceptibility testing, and retrospectively by NG-MAST. Epidemiological data were requested for all isolates in the study. RESULTS: The 106 isolates were separated into more sequence types (ST) than A/S classes (44 versus 17). All isolates within a sequence type had the same serotype, were homogeneous with respect to ciprofloxacin resistance category, but were sometimes heterogeneous with respect to auxotype or plasmid borne resistance to penicillin. Combined NG-MAST and epidemiological data revealed sustained transmission of several gonococcal strains predominantly within Greater Glasgow and Lothian. Clusters of isolates were associated with transmission within the United Kingdom, whereas isolates with unique STs were associated with foreign travel (p < 0.0001). CONCLUSIONS: NG-MAST is more discriminatory than A/S typing. Ciprofloxacin resistant gonococcal isolates in Scotland are heterogeneous, with endemic spread of some strains occurring predominantly in Greater Glasgow and Lothian.     

Antimicrobial susceptibility of Neisseria gonorrhoeae in Cuba (1995-1999): implications for treatment of gonorrhea

BACKGROUND: Antibiotic-resistant strains of Neisseria gonorrhoeae, especially those resistant to penicillin and tetracycline, have spread with remarkable rapidity in many Caribbean countries. GOAL: The goal of the study was to survey the antibiotic susceptibilities of N gonorrhoeae strains isolated from 1995 to 1999 in Cuba and to discuss the impact of antimicrobial resistance on the management of gonorrhea in the country. STUDY DESIGN: Susceptibility of the strains to penicillin, tetracycline, cefuroxime, ceftriaxone, ciprofloxacin, spectinomycin, and azithromycin were determined by an agar dilution method. RESULTS: Penicillin and tetracycline resistance was noted in 60.8% and 54.2%, respectively, of the N gonorrhoeae strains tested. A total of 63.35 (76/120) of the N gonorrhoeae strains exhibited plasmid-mediated resistance to penicillin, tetracycline, or both. Strains with chromosomally mediated resistance to these antibiotics accounted for 10% (12/120) of the strains. The strains were susceptible to ceftriaxone, cefuroxime, spectinomycin, and ciprofloxacin. One strain's ciprofloxacin MIC was 0.125 mircog/ml. Of the 52 strains tested, 23.1% displayed intermediate resistance to azithromycin. CONCLUSIONS: N gonorrhoeae strains exhibited a high frequency of resistance and multiresistance to penicillin and tetracycline. Therefore, these antibiotics should no longer be used to treat gonococcal infections in Cuba and should be substituted with effective drugs such as third-generation cephalosporins, spectinomycin, and fluoroquinolones. The detection of intermediate resistance to azithromycin and ciprofloxacin underlines the importance of periodic surveillance for susceptibility of N gonorrhoeae strains to antimicrobials agents used as primary therapy for gonorrhea.     

Analysis of the antibiotic sensitivity of Neisseria gonorrhoeae in Guangzhou, Peoples Republic of China

BACKGROUND: Sexually transmitted diseases began to re-emerge in China in the mid 1980s. During the last one and a half decades, Neisseria gonorrhoeae infection has become one of the three most common sexually transmitted diseases in China. At present, resistant strains of N. gonorrhoeae are increasing each year. This study was undertaken to better understand the sensitivity of five antibiotics to N. gonorrhoeae isolates in Guangzhou, China. GOAL: To determine the frequency and diversity of antibiotic resistance, particularly to penicillin and tetracycline, on gonococcal strains in Guangzhou. STUDY DESIGN: Strains of N. gonorrhoeae isolates from 203 patients with uncomplicated urethral gonococcal infections from Guangzhou, China were reviewed from September 1997 to August 1998. All strains were characterized with five different antimicrobials for sensitivity, including penicillin, tetracycline, spectinomycin, ciprofloxacin, and ceftriaxone. RESULTS: Penicillin resistance was present in 121 of 203 isolated strains (59.6%). The plasmid-mediated strains and chromosome-mediated strains among the penicillin-resistant strains that were resistance to penicillin were 5.8% and 94.2%, respectively. Plasmid-mediated strains resistant to penicillin and tetracycline were each 3.4%. Most isolated strains were resistant to ciprofloxacin, accounting for 60.6%. All strains were sensitive to spectinomycin and ceftriaxone. CONCLUSION: N. gonorrhoeae isolates exhibited a high rate of resistance to penicillin and ciprofloxacin. Spectinomycin highly effective for penicillin-producing N. gonorrhoeae, tetracycline-resistant N. gonorrhoeae and the highly resistant strains of ciprofloxacin.     

1999-2006年南京地区淋球菌对环丙沙星耐药现状的分析

目的 了解南京地区1999-2006年淋球菌对环丙沙星的耐药现状.方法 对1999-2006年在南京地区性病门诊患者中分离到的1208株淋球菌,采用琼脂稀释法测定环丙沙星的最小抑菌浓度(MIC).结果 对环丙沙星耐药(MIC 1mg/L)的淋球菌率由1999年的83.93%(94/112)上升至2006年的98.99%(196/198),平均总耐药率为96.61%(1167/1208).其中环丙沙星高度耐药(MIC≥4mg/L)的淋球菌比率达71.61%(865/1208).结论 南京地区流行的淋球菌对环丙沙星的耐药情况极其严重.     

Molecular characterization of ciprofloxacin resistance of gonococcal strains in Spain

BACKGROUND: Over the past several years, the emergence of gonococcal isolates with intermediate or full resistance to fluoroquinolones has become a significant concern in several countries, including Spain. GOAL: The goal was to determine the occurrence of ciprofloxacin resistance among Neisseria gonorrhoeae strains in Spain during 2000 to 2001 and determine the frequency and patterns of mutations at gyrA, gyrB, and parC genes in these isolates. STUDY DESIGN: Eleven ciprofloxacin-resistant strains (with MICs ranging from 1 to 64 micrograms/mL) and two intermediate isolates (with MICs of 0.12 and 0.5 microgram/mL) were found. Mutations were identified by polymerase chain reaction and direct sequencing of the amplified products. RESULTS AND CONCLUSIONS: Alterations at Ser-91 and Asp-95 in GyrA were detected in all strains except one, an isolate for which the MIC was 0.12 microgram/mL. Alterations in ParC were more variable, and there was no clear correlation between the number of parC mutations and the level of resistance. No alterations at gyrB gene associated with ciprofloxacin resistance were found. The resistance was distributed among different types of strains, suggesting that the increase in the incidence of ciprofloxacin-resistant strains in Spain was not exclusively due to the appearance of a single-strain outbreak.     

Alarming increase in ciprofloxacin- and penicillin-resistant Neisseria gonorrhoeae isolates in New Delhi,India

BACKGROUND: Resistance of ciprofloxacin has been reported in several regions of the world, including India. In India, ciprofloxacin is still being used as single-dose treatment for gonorrhea. GOAL: The aim of the study was to determine the antimicrobial susceptibility of Neisseria gonorrhoeae isolates from patients with acute gonococcal urethritis in New Delhi. STUDY DESIGN: By means of disc diffusion, we determined the susceptibility profiles of N gonorrhoeae isolates, determined the MICs of ciprofloxacin, penicillin, and ceftriaxone, and compared our data with previous findings. RESULTS: On the basis of MIC values, 35.3% and 52.9% of strains were found to be resistant and less sensitive, respectively, to penicillin; 67.3% and 28.2% strains were observed to be resistant and less sensitive, respectively, to ciprofloxacin. Only one isolate (5.9%) was found to be less sensitive to ceftriaxone. CONCLUSION: The significant increase in ciprofloxacin resistance in the current study indicates that resistance has developed under selective antibiotic pressure.     

Surveillance of antimicrobial susceptibilities in Neisseria gonorrhoeae in Nanjing, China, 1999-2006

OBJECTIVE: To monitor the frequency and types of antibiotic resistance of Neisseria gonorrhoeae in Nanjing, China, between 1999 and 2006. METHODS: beta-Lactamase production was determined by paper acidometric testing. Minimum inhibitory concentrations (MICs) to penicillin, ceftriaxone, tetracycline, ciprofloxacin, and spectinomycin were determined by agar plate dilution. Plasmid types were determined for TRNG and PPNG isolates by PCR. RESULTS: One-thousand two-hundred and eight N. gonorrhoeae isolates were examined. The rate of PPNG rose from 8.0% (9 of 112) in 1999 to 57.36% (113 of 197) in 2004, and declined to 44.44% (88 of 198) in 2006. Prevalence of TRNG increased from 1.8% (2 of 112) in 1999 to 32.82% (65 of 198) in 2006. 99.23% (258 of 260) of TRNG contained the Dutch-type tetM gene and 2 strains contained the American-type tetM gene. All PPNG examined contained the Asian type plasmid. Among non-PPNG, chromosomally mediated resistance to penicillin varied from 57.84% (59 of 102) to 87.80% (72 of 82). Chromosomal resistance to ciprofloxacin (QRNG) was detected in 83.93% (94 of 112) of the strains in 1999 and 98.99% (196 of 198) in 2006. Eight spectinomycin-resistant N. gonorrhoeae strains were detected between 2001 and 2006. None of the gonococcal isolates tested was resistant to ceftriaxone but decreased susceptibility was observed in some strains. CONCLUSIONS: Among N. gonorrhoeae strains isolated in Nanjing, China, plasmid mediated resistance including PPNG and TRNG increased significantly between 1999 and 2006. Chromosomally mediated resistance to both penicillin and ciprofloxacin was also high during this period. Spectinomycin resistance of N. gonorrhoeae was sporadic. Ceftriaxone and spectinomycin can be considered effective antimicrobial agents for the treatment of gonorrhea in Nanjing at the present time.     

淋球菌抗生素耐药谱和质粒图谱研究

目的 为了解广州地区淋球菌的性素耐药谱和质粒谱。方法 采用琼脂稀释法测定了５种抗生素对８９株淋球菌的最小抑菌浓度（ＭＩＣ）和碱裂解法分析１０６株菌的质粒衅谱。结果 ２株为产β－内酰胺酶菌株（ＰＰＮＧ）,３株为质粒介导的高度耐四环素菌株９ＴＲＮＧ０;环丙沙星耐药率较高（６２．９％）,青霉素次之（５９．５％）,头孢三嗪和壮观霉素未发现耐药菌株。质粒检出率为９０．６％,其中２．６Ｍｄ隐蔽质粒携带率为８５．６％,４．５ＭｄＲ质粒为６７．８％,２４．５Ｍｄ结合质粒为３３．８％。质粒谱型以２．６Ｍｄ＋４．５Ｍｄ和２．６Ｍｄ＋４．５＋ｉ２４．５Ｍｄ多见,分别为３７．７％和２５．４％。结论 表明了广州地区淋球菌抗生素耐药谱和质粒图谱,有助于淋病的治疗和防治。