临床分离铜绿假单胞菌质粒介导的喹诺酮耐药机制研究

目的了解临床分离的铜绿假单胞菌中PMQR基因及ESBLs的分布情况,并对PMQR阳性菌株中染色体介导的喹诺酮耐药机制进行分析。方法采用琼脂稀释法测定菌株对环丙沙星和左氧氟沙星的药物敏感性;PCR检测qnr A、qnr B、qnr C、qnr D、qnr S、aac(6’)-Ib-cr和qep A,对PMQR阳性菌株扩增blaTEM、blaSHV、blaCTX-M和blaPER,同时扩增测序分析染色体基因gyr A、gyr B、par C和par E的突变情况;接合转移试验验证PMQR与bla基因的转移性。结果 106株铜绿假单胞菌中,2株携带qnr S,1株携带qnr D,2株携带aac(6’)-Ib-cr。4株PMQR阳性菌株中有2株接合转移成功,qnr S1和blaTEM-1基因可以通过质粒共同转移。PMQR阳性菌株均在Gyr A亚基和/或Par C亚基存在氨基酸突变,其相应的接合子以及受体菌均未发现突变。结论临床分离的铜绿假单胞菌中存在qnr S、qnr D和aac(6’)-Ib-cr基因,PMQR与bla基因能共同转移,造成多重耐药的传播。     

质粒介导的克雷伯菌耐喹诺酮类药物机制研究

目的了解华南地区qnr基因介导的克雷伯菌耐喹诺酮类药物的情况并研究其耐药机制。方法收集临床分离的克雷伯菌株共200株，其中产酸克雷伯菌6株。PCR方法筛查基因，琼脂稀释法测MIC，质粒结合试验，聚合酶链反应（PCR）通用引物扩增各组基因及测序。结果200株细菌中筛查到带qnr基因的菌株共2株（其中产酸克雷伯菌1株），均对环丙沙星敏感。进一步确证实验中证实2菌株都含qnr基因。2菌株经结合实验后在选择平板上都有菌生长，而且对环丙沙星的MIC值均有30倍以上的的提高。2株菌均有gyrA Ser83→Tyr突变，产酸克雷伯菌株有parC Ser80→Ile突变。2株菌质粒PCR扩增的qnr产物测序结果与NCBI中qnr基因比对吻合率达100％。结论华南地区已有质粒介导的耐喹诺酮类菌株存在，它们能够跨种属转移，值得临床医生重视。     

耐氟喹诺酮类铜绿假单胞菌gyrA及parC基因突变研究

目的　研究临床分离的耐氟喹诺酮类铜绿假单胞菌gyrA及parC基因突变情况。方法　测定临床分离的 5 5株铜绿假单胞菌MIC值 ,从中筛选出 1株敏感菌和 8株耐药菌 ,以标准敏感菌株ATCC2 785 3作为质控菌株。用聚合酶链反应 (PCR)扩增gyrA及parC基因的喹诺酮耐药决定区 (QR DR) ,扩增产物片段长度分别为 35 1bp、397bp。用限制性内切酶SacⅡ消化gyrAPCR产物 ,同时对上述 10株菌的gyrA及parC基因的喹诺酮决定区 (QRDR)进行PCR DNA直接测序分析。结果　有 8株耐菌株的gyrA基因在 83位 (ACC→ATC)有突变 ,导致氨基酸Thr→Ile的改变 ;有 3株高度耐药菌gyrA基因同时在 87位 (GAC→GGC)有突变 ,导致氨基酸Asp→Gly的改变 ;有 4株耐药菌株的parC基因在 87位有TCG→TTG突变 ,导致氨基酸由Ser→Leu的改变。同时具gy rA和parC突变MIC值是仅具gyrA突变菌株MIC值的 2～ 16倍。未发现parC突变单独存在。另外 ,有 6株耐药菌gyrA的 132位有CAC→CAT的突变 ;所有耐药菌株parC基因 115位有GCT→GCG的突变 ,该突变未引起氨基酸的改变。结论　gyrA83、87位突变及parC基因 87位突变都可引起铜绿假单胞菌对氟喹诺酮类药物产生耐药 ,但以gyrA基因 83位突变为主 ,合并gyrA基因 87位及parC基因 87位突变可增加耐药程度。     

碳青霉烯类耐药肺炎克雷伯菌临床分离株中质粒介导的喹诺酮类耐药基因检测

目的：探讨质粒介导的喹诺酮类耐药（PMQR）基因在碳青霉烯类耐药肺炎克雷伯菌（CRKP）临床分离株中的分布情况。方法：收集CRKP29株,聚合酶链反应（PCR）扩增并确定产物基因型。结果：CRKP中PMQR基因检出率为48．3％（14／29）,其中qnrB5株,包括qnrB21株、qnrB43株、qnrB101株;qnrS 5株,均为qnrS1;1株同时携带qnrS1和qnrB4;有3株携带aac（6′）-Ib-cr基因。所有PMQR基因阳性菌株均同时携带β-内酰胺酶基因,其中8株同时携带碳青霉烯酶基因,占57．1％（8／14）,以blaKPC-2（4／14）及blaNDM-1（3／14）为主。结论：PMQR基因在临床分离的CRKP中较为普遍,以qnr基因为主,且qnr阳性菌株碳青霉烯酶基因携带率较高,均为多重耐药株。     

市售整鸡中环丙沙星耐药大肠埃希氏菌的分布及耐药机制研究

目的 本研究旨在阐明市售整鸡中环丙沙星耐药大肠埃希氏菌的分布和耐药机制特点.方法 对广东省3个不同地区市售整鸡中的环丙沙星耐药大肠埃希氏菌进行分离和鉴定,并对分离株进行种系分群、药敏试验和喹诺酮耐药机制研究.结果与结论 从58份市售整鸡中分离出41株环丙沙星耐药大肠埃希氏菌,其中27株属于A群.分离株耐药谱主要有两种:AMP-CAZ-CIP-CTX-Cl-SXT-TET和AMP-CAZ-CIP-CTX-Cl-GEN-SXT-TET.喹诺酮耐药机制研究显示,拓扑异构酶编码基因gyrA和parC均有点突变出现,其中,26株分离株携带质粒介导的喹诺酮耐药基因,包括oqxAB、qnrS、aac(6')-Ib-cr,而qnrA、qnrB、qnrC、qnrD和qepA基因则均未检出.耐药菌株在市售整鸡中的广泛分布和复杂的喹诺酮耐药机制,应引起相关部门的重视.     

大肠埃希菌gyrA、parC和marOR基因突变与喹诺酮耐药的相关性

目的:研究大肠埃希菌gyrA、parC和marOR基因突变与喹诺酮类耐药的相关性。方法:采用微量稀释法进行常规药敏试验,筛选3株萘啶酸敏感大肠埃希菌和37株萘啶酸耐药大肠埃希菌株;PCR扩增大肠埃希菌喹诺酮耐药决定区(QRDR)相关gyrA、parC基因,进行聚合酶链反应-单链构象多态性(PCR-SSCP)分析,同时PCR扩增marOR基因;在耐药株选取部分菌株对gyrA、parC及marOR基因进行测序,检测其突变情况,其结果与体外药敏试验结果进行比较,研究其相关性。结果:37株耐药株均出现gyrA基因突变,但对环丙沙星低耐株最低抑菌浓度(MIC)=2mg/L只出现gyrA单位点突变,而parC基因未发生突变;环丙沙星高耐株(MIC=64mg/L)gyrA基因出现3个位点突变,parC基因出现单位点突变;在环丙沙星高耐株(MIC=256mg/L),并伴有其他类抗菌药物的多重耐药时,除了出现gyrA和parC基因双位点突变,同时检测到marOR基因的多位点突变。结论:gyrA和parC基因突变在大肠埃希菌对喹诺酮耐药中起着重要作用,gyrA和parC基因突变的程度与大肠埃希菌耐药水平有关,marOR基因多位点突变在多重耐药机制中具有一定的作用。     

志贺菌临床株耐药性分析及对氟喹诺酮类抗生素耐药机制的研究

目的:了解本地区志贺菌抗生素耐药情况,探讨志贺菌对氟喹诺酮类药物的耐药机制和耐药基因的突变及流行情况。方法:K-B纸片扩散法测定2009—2010年天津地区临床分离的119株志贺菌的药敏情况,对氟喹诺酮耐药志贺菌的gyrA、parC基因及质粒介导的喹诺酮耐药(PMQR)基因qnrA、qnrB、qnrS、aac(6′)-ib-cr、qepA进行扩增、测序,将PMQR阳性菌株与大肠埃希菌J53ARZ进行质粒接合试验,比较接合前后受体菌对抗菌药物的敏感性变化。结果:119株志贺菌对萘啶酸敏感率最低(1.72%),其次为氨苄西林(2.52%)及复方磺胺甲口恶唑(3.36%)。福氏志贺菌与宋内氏志贺菌对氟喹诺酮耐药性差别较大,5株志贺菌对环丙沙星等氟喹诺酮耐药,均为福氏志贺菌,其中2株对左氧氟沙星耐药。4株同时存在gyrA83、87位点及parC80位点突变,1株缺乏gyrA87位点突变。PMQR基因阳性菌3株,包括1株qnrS及2株aac(6′)-ib-cr阳性菌,接合菌对多种抗生素的敏感性降低。结论:本地区志贺菌临床株对多种抗生素的多重耐药率较高,对氟喹诺酮耐药率低于5%。喹诺酮耐药机制既有染色体介导靶位酶突变,也存在质粒介导喹诺酮耐药。     

天津地区大肠埃希菌临床株质粒介导的喹诺酮类耐药机制的研究

目的 了解天津地区临床分离的大肠埃希菌中qnr,aac(6')-Ib-cr及gepA基因的流行情况,分析阳性菌株感染的微生物学及临床特征.方法 从天津某三甲医院收集环丙沙星耐药(CPLX,MIC 4gg/mL)的大肠埃希菌共75株,采用PCR法检测gnrA,gnrB,gnrS,aac(6')-Ib及gepA基因,对aac(6'),-Ib基因阳性菌株用Fok I酶切确认aac(6')-Ib-cr基因,接合试验验证qnr的转移性.所有阳性菌株用PCR法检测p-内酰胺酶基因,并收集阳性菌株感染患者临床资料进行分析.结果 75株环丙沙星耐药的大肠埃希菌中共有18株(24%)携带qnr基因和(或)aac(6)-Ib-cr基因,其中gnrB,gnrS和aac(6')-Ib-cr检出率分别为5.3%,4%和21.3%,未检出gnrA和gepA o 5株qnr阳性菌株均接合传递成功.18株gnr1aac(6')-1b-cr阳性的大肠埃希菌中均检测出R-内酸胺酶基因.阳性菌株对喹诺酮类和头孢菌素类药物高度耐药且主要来源于泌尿系感染,感染患者均为中老年人.结论 天津地区临床存在qnr和aac(6')-Ib-cr阳性菌株的流行,这是首次在天津发现qnr介导的喹诺酮类耐药.     

肺炎克雷伯茵耐氟喹诺酮机理研究

目的：探讨肺炎克雷伯菌耐氟喹诺酮类药物的机理。方法：采用NCCLS推荐的K—B法测定50株肺炎克雷伯菌对氟喹诺酮类药物的耐药性并初步筛选出耐环丙沙星菌株。试管稀释法测定耐环丙沙星菌株对环丙沙星和左氧氟沙星的最低抑菌浓度（MIC）。对此23株菌GyrA的基因（gyrA）进行PCR扩增和基因序列的分析比较。结果：23株耐环丙沙星肺炎克雷伯菌中,20株存在gyrA变异：Ser83（TCC）→Phe（TTC）、Tyr（TAC）,Asp87（GAC）→Asn（AAC）、Ala（GCC）。结论：肺炎克雷伯菌对氟喹诺酮类药物耐药机理主要与药物作用靶位gyrA基因的突变有关,并且gyrA基因突变位点越多其耐药程度越高。     

肺炎克雷伯菌耐氟喹诺酮机理研究

目的:探讨肺炎克雷伯菌耐氟喹诺酮类药物的机理。方法:采用NCCLS推荐的K-B法测定50株肺炎克雷伯菌对氟喹诺酮类药物的耐药性并初步筛选出耐环丙沙星菌株。试管稀释法测定耐环丙沙星菌株对环丙沙星和左氧氟沙星的最低抑菌浓度(MIC)。对此23株菌GyrA的基因(gyrA)进行PCR扩增和基因序列的分析比较。结果:23株耐环丙沙星肺炎克雷伯菌中,20株存在gyrA变异:Ser83(TCC)→Phe(TTC)、Tyr(TAC),Asp87(GAC)→Asn(AAC)、Ala(GCC)。结论:肺炎克雷伯菌对氟喹诺酮类药物耐药机理主要与药物作用靶位gyrA基因的突变有关,并且gyrA基因突变位点越多其耐药程度越高。     

质粒介导喹诺酮耐药基因阳性菌株中超广谱β-内酰胺酶的研究进展

质粒介导的喹诺酮耐药(PMQR)基因是近年来新发现的细菌耐药机制,研究发现PMQR阳性菌株也往往对大部分β-内酰胺类抗菌药物耐药而表现为多药耐药,最主要的原因是该类细菌产生了能分解绝大多数β-内酰胺类药物的超广谱β-内酰胺酶(ESBLs).PMQR基因阳性菌株中ESBLs的发生率和主要型别在世界各地的报道各不相同,现就质粒介导喹诺酮耐药基因阳性菌株中超广谱β-内酰胺酶的基本进展进行综述.     

质粒介导的喹诺酮耐药基因在中国大陆尿液分离的大肠埃希菌中的广泛分布

目的分析中国大陆20家三甲医院尿来源大肠埃希菌的耐药特点并调查质粒介导的喹诺酮类耐药基因的分布情况和流行特点。方法收集卫生部全国耐药监测网2007年1月至2008年3月非重复298株尿液分离大肠埃希菌;琼脂稀释法测定其对20种抗菌药物的敏感性,多聚酶链反应和DNA测序分析qn-rA,qnrB,qnrS,aac(6’)-ib和qepA基因的流行性;接合实验分析质粒的转移性;Eric-PCR分析喹诺酮基因阳性菌株之间的遗传相关性;卡方检验用于分析耐药基因与氟喹诺酮耐药之间的相关性。结果 298株大肠埃希菌对20种抗菌药物耐药现象严重,其中对环丙沙星和左氧氟沙星有很高的耐药性,耐药率高达78.5%和74.2%。经基因比对分析,62株(20.8%)细菌携带aac(6’)-Ib基因;45株(15.1%)细菌携带喹诺酮耐药基因,1株(0.3%)检测出qnrA基因,3株(11.4%)检出qnrB基因,5株(1.7%)检出qnrS基因,25株(8.4%)确定为aac(6’)-Ib-cr基因,12株(4.7%)检出qepA基因;此外,有3株细菌分别发现aac(6’)-Ib-cr和qepA1基因aac(6’)-Ib-cr和qnrB1基因,qepA和qnrS1基因共存。45株喹诺酮基因阳性菌株之间具有很大的遗传差异,并且其中有16株细菌携带的基因具有可转移性。aac(6’)-Ib的流行性与细菌的环丙沙星和左氧氟沙星不敏感性相关(P<0.05);喹诺酮耐药基因的流行性与细菌的氟喹诺酮不敏感性相关(P<0.05)。结论尿液分离的大肠埃希菌耐药严重,质粒介导的喹诺酮耐药基因主要以aac(6’)-ib-cr为主,qepA1次之,这些潜在播散的喹诺酮耐药基因对于临床尿路感染的治疗有很大的挑战。     

Prevalence of β-lactamases and 16S rRNA methylase genes amongst clinical Klebsiella pneumoniae isolates carrying plasmid-mediated quinolone resistance determinants

To characterise the prevalence of β-lactamases and 16S rRNA methylase genes amongst clinical Klebsiella pneumoniae isolates carrying plasmid-mediated quinolone resistance (PMQR) determinants in China, 59 non-duplicate K. pneumoniae isolates harbouring at least one PMQR gene were screened for common β-lactamases and 16S rRNA methylases genes. The genetic relatedness of the isolates was analysed by pulsed-field gel electrophoresis (PFGE). Most of PMQR gene-positive isolates carried no substitutions within the quinolone resistance-determining regions (QRDRs) or single point mutation in GyrA or ParC. Over one-half (52.5%) of the isolates exhibited decreased susceptibility to ciprofloxacin [minimum inhibitory concentration (MIC)=0.5-2 μg/mL] or low-level resistance to ciprofloxacin (MIC=4-8 μg/mL). qnr, aac(6')-Ib-cr and qepA were positive in 52 (88.1%), 16 (27.1%) and 3 (5.1%) isolates, respectively. The identified genes for β-lactamases were distributed as follows: bla(TEM), 50.8%; bla(SHV), 91.5%; bla(CTX-M), 55.9%; bla(DHA), 59.3%; and bla(OXA-1), 22.1%. armA and rmtB were detected in 16.9% and 3.4% of isolates, respectively. All qnrB were detected in DHA-producing K. pneumoniae. Approximately 81.3%, 68.8% and 43.8% of aac(6')-Ib-cr carrying isolates produced OXA-1, DHA and ArmA, respectively. In conclusion, owing to few QRDR substitutions, most of the PMQR gene-carrying K. pneumoniae isolates exhibited low-level resistance to fluoroquinolones. qnr appears to be the predominant PMQR gene and it presented a significant correlation with bla(SHV), bla(CTX-M) and bla(DHA), whereas aac(6')-Ib-cr exhibited a close relationship with bla(OXA-1), bla(DHA) and armA. qepA was rarely detected in this study.     

质粒介导的喹诺酮类耐药机制研究进展

质粒介导的喹诺酮类抗菌药物的耐药是近十几年来新发现的一类细菌耐药机制,可在肠杆菌科细菌中水平传播,引起的感染不易控制,导致院内感染大范围流行.本文对质粒介导喹诺酮耐药基因的发现及种类、遗传背景、对喹诺酮类的作用机制及其临床意义等方面进行综述,为研究新型喹诺酮类抗菌药物及抗感染治疗中合理使用氟喹诺酮类抗菌药物提供依据.     

Antimicrobial activities of gentamicin against fresh clinical isolates

Antimicrobial activities of gentamicin (GM), compared with activities of other aminoglycosides (AGs) and beta-lactam antibiotics, were studied against clinical isolates obtained during a period of July-December 1989. 1. GM-resistant strains were noted in 24% of Staphylococcus aureus, 12% of Enterobacter spp., 24% of Serratia marcescens, 7% of Morganella morganii and 26% of Pseudomonas aeruginosa, but no GM-resistant strains were observed among isolates of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis and Proteus vulgaris. 2. A majority of GM-resistant strains of S. aureus were methicillin-resistant S. aureus (MRSA) and a large number of GM-resistant strains of Enterobacter spp. was also resistant to new quinolones. GM showed, however, strong antimicrobial activities against new quinolones-resistant strains of S. marcescens, M. morganii and P. aeruginosa. 3. Among all the isolates tested of S. marcescens, 24% were GM-resistant, 72% were tobramycin (TOB)-resistant, 86% were dibekacin (DKB)-resistant and 64% were amikacin (AMK)-resistant, hence the incidence of GM-resistant strains was the lowest. This tendency was also observed with P. vulgaris. However, among P. aeruginosa, 26% were GM-resistant, 14% TOB-resistant, 18% DKB-resistant and 22% AMK-resistant, thus the incidence rate for GM-resistance was somewhat higher. These results suggest that different AGs-modification enzymes were produced by various clinical isolates under the present condition. 4. Comparing the ratio of GM-resistant strains in the present study with those in 1980 and 1983, the ratio increased among S. aureus, while decreases were observed among Enterobacter spp., S. marcescens, P. vulgaris and P. aeruginosa, indicating that a unilateral tendency of increases in GM-resistant strains did not exist among clinical isolates over the years.     

20种抗菌药物对肺炎链球菌的体外抗菌活性研究

目的：评价莫西沙星等20种常用抗菌药物对临床分离的60株肺炎链球菌的体外抗菌活性。方法：采用微量肉汤稀释法测定20种抗菌药物对肺炎链球菌的最低抑菌浓度（MIC）。结果：60株肺炎链球菌中有青霉素敏感的肺炎链球菌（PSSP）42株（71．7％）,青霉素不敏感肺炎链球菌（PNSSP）18株（28．3％）;其中,青霉素耐药的肺炎链球菌（PRSP）有2株（3．3％）。对PSSP菌株,20种抗菌药物中敏感率较高的药物有头孢曲松、头孢噻肟、加替沙星、莫西沙星、左氧氟沙星、阿莫西林／克拉维酸,敏感率均为100％;耐药率较高的药物有红霉素、罗红霉素、克拉霉素、阿奇霉素,耐药率分别为83-3％,83-3％,74．7％,74．7％。对PNSSP菌株,敏感率较高的药物有阿莫西林／克拉维酸、莫西沙星、头孢噻肟、加替沙星、左氧氟沙星,敏感率分别为100％,100％,88．8％,94．4％,94．4％;耐药率较高的药物有红霉素、克拉霉素、阿奇霉素,耐药率均为66．7％。20种抗菌药物对60株肺炎链球菌的累积抑菌百分率曲线显示莫西沙星和阿莫西林／克拉维酸的抑菌能力最强。结论：肺炎链球菌对大环内酯类、复方新诺明、磷霉素等抗菌药物的耐药率较高,第三、四代氟喹诺酮类药物（左氧氟沙星、莫西沙星、加替沙星）和阿莫西林／克拉维酸及第三代头孢菌素中的头孢噻肟、头孢曲松等对肺炎链球菌（包括PNSSP）有很好的抗菌活性,提示其可作为高度耐药肺炎链球菌感染的首选药物。     

Antimicrobial susceptibility of clinical isolates of aerobic gram-positive cocci and anaerobic bacteria in 2008

The activity of antibacterial agents against aerobic Gram-positive cocci (25 genus or species, 1029 strains) and anaerobic bacteria (21 genus or species, 187 strains) isolated from clinical specimens in 2008 at 16 clinical facilities in Japan were studied using either broth microdilution or agar dilution method. The ratio of methicillin-resistant strains among Staphylococcus aureus and Staphylococcus epidermidis was 59.6% and 81.2%, suggesting that resistant strains were isolated at high frequency. Vancomycin (VCM), linezolid (LZD) and quinupristin/dalfopristin (QPR/DPR) had good antibacterial activity against methicillin-resistant S. aureus and methicillin-resistant S. epidermidis, with MIC90s of < or = 2 microg/mL. The ratio of penicillin (PC) intermediate and resistant strains classified by mutations of PC-binding proteins among Streptococcus pneumoniae was 92.0% that was highest among our previous reports. Cefpirome, carbapenems, VCM, teicoplanin (TEIC), LZD and QPR/DPR had MIC90s of < or = 1 microg/mL against PC-intermediate and resistant S. pneumoniae strains. Against all strains of Enterococcus faecalis and Enterococcus faecium, the MICs of VCM and TEIC were under 2 microg/mL, and no resistant strain was detected, suggesting that these agents had excellent activities against these species. 15.9% of E. faecalis strains and 1.2% of E. faecium strains showed intermediate to LZD. 17.1% of E. faecium strains showed intermediate or resistant to QPR/DPR. Against all strains of Clostridium difficile, the MIC of VCM was under 1 microg/mL, suggesting that VCM had excellent activity. Carbapenems showed good activity against Clostridiales, Bacteroides spp., and Prevotella spp., but one strain of Bacteroides fragilis showed resistant to carbapenems. And so, the susceptibility of this species should be well-focused in the future at detecting continuously.     

Macrolide-lincosamide-streptogramin B resistance phenotypes in clinical staphylococcal isolates

The prevalence of macrolide-lincosamide-streptogramin B (MLSB) resistance as well as the MLSB resistance phenotypes were investigated by the double-disk diffusion test among 532 clinical staphylococci isolates in a Turkish university hospital. The activity of other antimicrobials, including trimethoprim/sulfamethoxazole, telithromycin, quinupristin/dalfopristin, linezolid, gentamicin, chloramphenicol, ciprofloxacin and vancomycin, was also evaluated. Of 532 isolates, 38.5% were resistant to MLSB antibiotics; 63.9% of the resistant isolates exhibited a constitutive phenotype (cMLSB) whereas 36.1% expressed an inducible resistance phenotype (iMLSB). MLSB resistance was more prevalent among coagulase-negative staphylococci (CoNS) strains. Oxacillin-resistant strains exhibited significantly higher MLSB resistance rates compared with oxacillin-susceptible strains (P<0.0001). The most frequently detected resistance phenotype among the total staphylococcal isolates was the constitutive type and this phenotype was more frequently encountered among oxacillin-resistant strains. With the exception of the fully active agents such as vancomycin, linezolid and quinupristin/dalfopristin, the most effective antibiotics were telithromycin and chloramphenicol among all isolates. Susceptibility rates to other antibiotics tested were higher among isolates without MLS(B) resistance than isolates with MLSB resistance. The detection of a considerable rate (43.5%) of iMLSB resistance among erythromycin-resistant/clindamycin-susceptible strains suggests that the true percentage of clindamycin resistance may be underestimated if testing for inducible resistance is not performed.     

Clinical studies on cefteram pivoxil in the field of pediatrics

Cefteram pivoxil (CFTM-PI) was administered to 37 patients with acute febrile upper or lower respiratory infections and 3 patients with urinary tract infections at 10 mg/kg/day divided into 3 portions. Good clinical effects were observed in all the cases. As for the bacteriological effect, the evaluable 24 strains (60.0%) were eradicated among 43 strains identified in 37 cases with the treatment with CFTM-PI. Only 2 strains were eradicated among 9 strains of Staphylococcus aureus. Among 3 patients with urinary tract infections with Escherichia coli, 2 strains were eradicated from urine after the administration of CFTM-PI. Four cases showed mild diarrhea among 40 cases. It was not clear whether the diarrhea was due to the administration of CFTM-PI.