Chronological development of Mycoplasma hyorhinis and Mycoplasma hyosynoviae infections in cultures of a swine synovial cell strain

The sequential development of Mycroplasma hyorhinis and Mycoplasma hyosynoviae was observed in cultures of a swine synovial fluid cell strain. An early transitory filamentous phase was observed with M. hyorhinis infection followed by the development of cell-associated, relatively large, round structures and some ring forms. Infection with M. hyorhinis was characterized by a generalized distribution of the organism and a severe cytopathic effect.Infection with M. hyosynoviae was represented by the development of circumscribed foci of small pleomorphic structures and a milder effect on the cells. At a high multiplicity of infection, this organism became associated with the cytoplasmic membranes of the cells.     

Whole Genome Analysis Reveals New Insights into Macrolide Resistance in Mycoplasma pneumoniae

Objective Mutations in 23 S rRNA gene are known to be associated with macrolide resistance in Mycoplasma pneumoniae(M. pneumoniae). However, these mutations alone do not fully explain the high resistance rates in Asia. The aim of this study was to investigate other possible mutations involved in macrolide resistance in M. pneumoniae. Methods The whole genomes of 10 clinical isolates of M. pneumoniae with macrolide resistance were sequenced by Illumina Hi Seq2000 platform. The role of the macrolide-specific efflux transporter was assessed by efflux-pump inhibition assays with reserpine and carbonyl cyanide m-chlorophenyl-hydrazone(CCCP). Results A total of 56 single nucleotide polymorphisms(SNPs) were identified in 10 clinical isolates in comparison to the reference strains M129 and FH. Strikingly, 4 of 30 SNPs causing non-synonymous mutations were clustered in macrolide-specific efflux system gene mac B encoding macrolide-specific efflux pump protein of the ATP-binding cassette transporter family. In assays of the minimal inhibitory concentrations(MIC) of macrolide antibiotics in the presence of the efflux pump inhibitors caused a significant decrease of MICs, even under detectable levels in some strains. Conclusion Our study suggests that macrolide efflux pump may contribute to macrolide resistance in M. pneumoniae in addition to the common point mutations in 23 S r RNA gene.     

Chemoprophylaxis with oral amoxycillin against bacterial endocarditis: when should second doses be administered after dentistry?

The adequacy of serum bactericidal activity after oral amoxycillin given as prophylaxis against infective endocarditis was studied using a double blind randomised protocol in healthy volunteers having dentistry. One hour before their procedure 38 patients received 3 g amoxycillin syrup and 12 received matching placebo. Venous blood samples were drawn before and one and nine hours after dosing and serum amoxycillin concentrations determined using a standard bioassay. Samples containing amoxycillin had inhibitory titres measured against two reference isolates of viridans streptococci known to have caused infective endocarditis. The susceptibility to amoxycillin of one strain was high and the other low, respective minimal bactericidal and inhibitory concentrations being 0.08 and 0.04 mumol/l (0.03 and 0.015 microgram/ml) and 2.74 and 1.37 mumol/l (1 and 0.5 microgram/ml). Amoxycillin was detected in only post-treatment samples of patients given the active drug. There were no significant correlations between one or nine hour drug concentrations and age or physical characteristics, nor was there any relation to preceding food consumption. Correlations between drug concentrations at one and nine hours were weak (r = 0.34; p less than 0.05), but between corresponding drug concentrations and serum inhibitory titres there were consistent correlations (r = 0.46-0.48; p less than 0.005). Against the low susceptibility reference isolate bactericidal amoxycillin concentrations were encountered in only 20 of the 38 nine hour samples (95% confidence limits 34% and 66%). When repeat doses of amoxycillin are indicated after dentistry they should be given about four hours later, not eight hours later as commonly practised.     

Amikacin therapy. Use against infections caused by gentamicin- and tobramycin-resistant organisms.

Amikacin sulfate was used in 24 treatment courses for 25 serious infections caused by aerobic or facultative anaerobic Gram-negative organisms resistant to numerous drugs. Sites of infection included urinary tract (11 cases), pleuropulmonary (6 cases), primary bacteremia (5 cases), and miscellaneous (3 cases). Serratia marcescens and Pseudomonas sp accounted for 73% of the isolates. The mean minimal inhibitory concentration (MIC) of these organisms to amikacin was 3.6 microgram/ml; to gentamicin, 39 microgram/ml; and to tobramycin, 32 microgram/ml. The mean peak serum concentration of the drug was 20.8 microgram/ml. Eleven patients were critically ill at the onset of therapy, and seven patients were bacteremic. The overall favorable response rate was 80%. The most serious side effect was ototoxicity, which occurred in three of 15 patients examined by serial audiometry.     

Whole Genome Analysis Reveals New lnsights into Macrolide Resistance in Mycoplasma pneumoniae

Objective Mutations in 23S rRNA gene are known to be associated with macrolide resistance in Mycoplasma pneumoniae (M. pneumoniae). However, these mutations alone do not fully explain the high resistance rates in Asia. The aim of this study was to investigate other possible mutations involved in macrolide resistance in M. pneumoniae.Methods The whole genomes of 10 clinical isolates of M. pneumoniae with macrolide resistance were sequenced by Illumina HiSeq2000 platform. The role of the macrolide-specific efflux transporter was assessed by efflux-pump inhibition assays with reserpine and carbonyl cyanide m-chlorophenyl-hydrazone (CCCP).Results A total of 56 single nucleotide polymorphisms (SNPs) were identified in 10 clinical isolates in comparison to the reference strains M129 and FH. Strikingly, 4 of 30 SNPs causing non-synonymous mutations were clustered in macrolide-specific efflux system gene macB encoding macrolide-specific efflux pump protein of the ATP-binding cassette transporter family. In assays of the minimal inhibitory concentrations (MIC) of macrolide antibiotics in the presence of the efflux pump inhibitors caused a significant decrease of MICs, even under detectable levels in some strains.Conclusion Our study suggests that macrolide efflux pump may contribute to macrolide resistance in M. pneumoniae in addition to the common point mutations in 23S rRNA gene.     

STUDY OF MINIMAL INHIBITORY CONCENTRATIONS AND MULTIPLE DRUG RESISTANCE PLASMIDS IN SALMONELLA TYPHI

S. typhi isolated from blood cultures were tested for minimal inhibitory concentrations of antimicrobial drugs using an simple easily fabricated multiple inoculator. Multiple drug resistant S. typhi were inhibited by high concentrations of ampicillin, sulphamethoxazole, trimethoprim and chloramphenicol (> 128 mg/L) suggestive of R factor mediated resistance. They showed presence of a single large plasmid with molecular weight ranging from 85 to 110 megadaltons. Sensitive S. typhi isolates were inhibited by lower concentrations of antimicrobial and did not show evidence of any plasmid. All isolates were equally sensitive to extremely low concentrations of ceftazidime, cefuroxime, ciprofloxacin, norfloxacin and gentamicin (< 0.5 mg/L).KEY WORDS: Salmonella typhi, Multiple drug resistance, Plasmids     

男性泌尿生殖道支原体感染132例检测及药敏试验

目的为了解本地区泌尿生殖道支原体的感染状况,以及解脲支原体和人型支原体对不同药物的体外敏感性。方法对83例支原体标本做套式聚合酶链反应(nPCR)检测,其余进行培养和药物敏感性检测。结果132例样本中,解脲支原体(Uu)、人型支原体(Mh)、肺炎支原体(Mpn)、生殖支原体(Mg)4种支原体阳性率分别为66.5%、31.9%、27.7%、17.0%,发酵支原体(Mf)和穿通支原体(Mpe)均为2.7%,梨支原体(Mpi)未检出。Uu和Mh对抗生素高度敏感的依次为交沙霉素、美满霉素、强力霉素、阿奇霉素、克拉霉素。结论本地区男性性病病人支原体感染率较高。Uu和Mh感染对常见的红霉素、四环素等已产生一定的耐药性,及时进行药敏试验、选择高效药物,对降低Uu和Mh耐药株的产生、防止复发和提高治愈率将起到重要作用。     

Serological cross-reactivity of porcine reference antisera to Mycoplasma hyopneumoniae, M. flocculare, M. hyorhinis and M. hyosynoviae indicated by the enzyme-linked immunosorbent assay, complement fixation and indirect hemagglutination tests

The enzyme-linked immunosorbent assay (ELISA) indicated significant cross-reactivity between the antigens of Mycoplasma hyopneumoniae ( HyoP ) and M. flocculare (Floc), another porcine mycoplasma of wide distribution but uncertain pathogenic significance, when porcine antisera of each specificity were tested against HyoP antigen. The titers of the anti-Floc sera ranged from threefold to 13-fold less than the titer of the anti- HyoP reference serum at different times after immunization. These values ranged from onefold less than to fourfold greater than the minimal positive titer of 80. The antisera to the other porcine mycoplasmal antigens [i.e. M. hyorhinis ( HyoR ) and M. hyosynoviae ( HyoS )] reacted less strongly to HyoP antigen but titers only slightly less than to slightly greater than the minimal positive titer were noted for some sera. Cross-reactivity was also detected by the complement fixation test, although the titers for this test were generally lower than for the ELISA, presumably reflecting lower sensitivity of the complement fixation test. Positive indirect hemagglutination titers to HyoP antigen were also observed for both anti-Floc sera obtained at one or more times during the immune response. With two exceptions (one anti- HyoR serum with a complement fixation titer of 16 and one anti- HyoR serum with an indirect hemagglutination titer of 10), none of the anti- HyoR or anti- HyoS sera had detectable indirect hemagglutination or complement fixation titers to HyoP antigen at any time after immunization. The levels of cross-reactivity detected by the complement fixation test and indirect hemagglutination and, especially, the ELISA would be of significance for the development of any practical sero-diagnostic test for mycoplasmal pneumonia of swine.     

1377例泌尿生殖道支原体感染的研究及药敏分析

目的:了解本地区泌尿生殖道支原体感染的现状及药敏情况,指导临床合理用药。方法:对1377例泌尿系感染患者进行支原体培养,采用支原体培养、药敏一体化试剂盒对其中的阳性标本进行8种抗生素药敏试验。结果:1377例患者中支原体阳性569例,感染率为41.32%;单一Uu(解脲支原体)感染、单一Mh(人型支原体)感染及Uu+Mh混合感染的感染率分别为26.32%、3.27%、11.73%;单一Uu感染显著高于单一Mh感染和Uu+Mh混合感染;药敏结果显示,敏感率最高的为强力霉素和交沙霉素,耐药率较高的包括环丙沙星、司帕沙星、罗红霉素、红霉素等。结论:本地区泌尿生殖道支原体感染应首选强力霉素和交沙霉素治疗,尤其是在无条件做药敏试验时,而对环丙沙星、司帕沙星等耐药性较高的药物,未做药敏试验时应慎重考虑。     

The action of certain antibiotics and ether on swine enzootic pneumonia

The susceptibility of Mycoplasma hyopneumoniae to the action of three antibiotics and diethyl ether was determined. Infected swine were used in an in vivo sensitivity detection system. The parameter of susceptibility was lesion prophylaxis. In vivo, Mycoplasma hyopneumoniae appeared to be resistant to diethyl ether, tylosin tartrate, and erythromycin, but was susceptible to the action of chlortetracycline. Chlortetracycline was effective in preventing the development of lesions when given at levels which would be practical in commercial swine operations.     

7098例泌尿生殖道标本支原体感染状况及药敏结果分析

目的了解近年来长沙地区泌尿生殖道支原体感染状况及常用药物敏感性的特征,为临床诊疗及合理用药提供依据。方法采集2016年6月—2017年2月门诊患者的泌尿生殖道标本,进行解脲脲原体(Uu)和人型支原体(Mh)培养及药敏试验,分析培养及药敏结果。结果共收集7 098例泌尿生殖道支原体标本,共检出阳性标本2 123例,总阳性率29.9%。女性患者感染率32.9%,男性患者感染率18.5%,不同性别患者感染率差异有统计学意义(P0.05)。不同年龄组间感染率差异有统计学意义(P0.05),48~57岁组感染率最高,≥68岁组感染率最低。不同型别以Uu单纯感染为主,占82.0%,其次是Uu+Mh混合感染,占14.4%。不同感染型别对常用药物存在不同程度的耐药,Uu+Mh混合感染的耐药率最高。结论近年来长沙地区泌尿生殖道支原体以Uu单纯感染为主,美满霉素、强力霉素和交沙霉素对不同型别支原体感染有较好的敏感性。     

氟康唑与两性霉素B抗白假丝酵母菌临床分离株的实验研究

目的评价白假丝酵母菌临床分离株对氟康唑(FCZ)与两性霉素B(AmB)的敏感性及两药相互作用的方式. 方法采用美国国家临床实验室标准化委员会M27-A推荐的棋盘微量稀释法,检测了22株白假丝酵母菌临床分离株对FCZ、AmB及两药联合的体外药物敏感性,同时对两药的作用方式进行了判定. 结果联合用药时,FCZ MIC值的几何均数从0.369 mg/L显著降低到0.227 mg/L,AmB MIC值的几何均数从0.223 mg/L显著降低到0.118 mg/L,22.73%受试菌表现为协同作用方式,63.14%的受试菌株表现为相加作用方式,13.64%受试菌株表现为无关作用方式,未观察到拮抗作用的出现.测定不同浓度下药物单独和联合作用的1株菌的菌落形成单位(cfu/ml),联合用药组都较单独用药组有明显减少,且对HF细胞和Hep-2细胞无毒性.结论 FCZ与AmB联合较任一药物单独使用体外抗白假丝酵母菌的活性高,且具有差异毒力.     

应用PCR—SSCP检测结核分支杆菌链霉素耐药基因的研究

结核病耐药问题十分严重，传统的药敏实验需1～2月。Sm是一线抗结核药物，结核分支杆菌耐Sm最常见的分子机制是由于核糖体S12蛋白编码基因（rpsL）突变。该文应用PCR－SSCP分析了62个结核分支杆菌临床分离株的rpsL基因，以H37Rv标准菌株为对照，13个药物敏感菌株中12个rpsL基因未见SSCP异常；37个耐Sm株中，31个（83．8％）有rpsL基因泳动异常；12个耐其它抗结核药物林中，仅1个单链DNA泳动异常。因此，PCR－SSCP有希望成为简便、快速地检测结核分支杆菌耐药突变株的方法，弥补常规药敏试验的不足，指导临床治疗。     

祁东地区泌尿生殖道支原体感染及耐药性变迁

目的探讨祁东地区2001-2007年间泌尿生殖道支原体感染状况及其耐药性变化,为临床合理用药提供参考。方法采用珠海丽珠试剂盒培养支原体及检测药敏。结果2006例标本中检出支原体阳性824例,检出率为41.1%,其中解脲脲原体（Uu）703例（85.3%）,解脲脲原体合并人型支原体（Uu＋Mh）93例（11.3%）,人型支原体（Mh）28例（3.4%）。药敏试验结果表明,强力霉素（敏感率83.7%）、交沙霉素（敏感率89.4%）、美满霉素（敏感率86.3%）敏感性较高且较稳定,其次为克拉霉素（敏感率77.9%）和阿奇霉素（敏感率56.7%）,左氟沙星、氧氟沙星、司帕沙星和罗红霉素敏感率逐年降低。支原体感染不同性别患者以及不同型别支原体对抗生素敏感性亦不同。结论祁东地区泌尿生殖道支原体感染以解脲支原体为主,治疗支原体感染宜首选交沙霉素。     

泌尿生殖道支原体的耐药性分析

目的:了解解脲脲原体(Uu)、人型支原体(Mh)在泌尿生殖道的感染状态及耐药状况。方法:对疑似患者送检的2623份标本进行Uu、Mh培养及药物敏感性测试,对Uu、Mh检出阳性率及对12种抗生素的耐药性做统计分析。结果:在本研究中,在2623份标本中支原体检出总阳性率为34.4%,仅检出Uu或Mh的标本阳性率分别为32.7%、1.0%,同时检出Uu和Mh的标本阳性率为1.0%。生殖道支原体感染中以Uu感染为主,占95.2%。支原体感染率女性明显高于男性(P<0.01)。对12种抗生素的耐药率分别从16.3%~71.6%不等。结论:Uu是泌尿生殖道支原体感染的主要病原体,Uu对红霉素的耐药率最高,对交沙霉素、克拉霉素、强力霉素、环脂红霉素敏感性较好,可作为治疗Uu感染的首选药物,但Mh的耐药性与Uu的耐药性很不一样,其耐药性要较Uu严重。     

1018例女性生殖道支原体感染及药敏分析

目的 了解女性泌尿生殖道支原体感染及耐药状况,指导临床合理用药.方法 对2009年1月至2010年12月湖南省人民医院1 018例女性生殖道分离的支原体及药敏试验结果进行回顾性分析.结果 在1 018例女性生殖道支原体感染阳性标本中,Uu感染阳性率为65.52％,Mh感染阳性率为5.21％,Uu+Mh混合感染阳性率为29.27％,Uu单项感染显著高于Mh感染和Uu+Mh混合感染(P＜ 0.01); Uu+Mh混合感染高于Mh感染(P＜0.01).药敏试验敏感率排在前5位的抗生素依次为交沙霉素、强力霉素、美满霉素、环酯红霉素和克拉霉素,敏感率分别为91.67％、89.69％、87.42％、66.4％和66.01％.结论 对有临床症状患者进行支原体培养、鉴定和药敏试验,选择敏感药物治疗,对控制支原体的传播和蔓延尤为重要.     

4 120例非淋菌性泌尿生殖道炎支原体感染检测分析

目的 分析泌尿生殖道炎患者支原体感染情况及其耐药谱。方法 采用支原体培养、鉴定、药敏一体试剂盒对4120例NGU分泌物进行检测，同时测定支原体对抗生素的耐药性。结果 4120例NGU患者中单纯UU感染1651株，阳性率40．07％，单纯MH感染23株，阳性率0．56％，UU＋MH混合感染175例，阳性率4．25％。UU、MH、UU＋MH对交沙霉素、强力霉素、美满霉素较为敏感；UU对克拉霉素高度敏感，但对于MH、UU＋MH则高度耐药。结论 泌尿生殖道支原体感染主要以UU为主，单纯MH感染少见；单纯UU、MH和UU＋MH三者的耐药性存在一定差异，临床治疗应根据药敏结果选择敏感药物。     

泌尿生殖道支原体检测及药敏结果分析

目的:了解南京地区泌尿生殖道支原体(Mycoplasma)的感染情况及其对抗生素的敏感性,以指导临床合理用药。方法:应用常规方法对2520例泌尿生殖道疾病患者的分泌物进行支原体鉴定及药敏检测,并对结果进行统计学分析。结果:在我院性病门诊就诊患者的2520例样本中。阳性数为1191例,感染率为47.26%,其中解脲支原体(Uu)阳性785例,占31.15%.人型支原体(Mh)阳性96例,占3.8%。Uu+Mh阳性310例,占12.3%,时9种抗生素:强力霉素、美满霉素、交沙霉素、克拉霉素、罗红霉素、阿奇霉素、氧氟沙星、左旋氧氟沙星、司帕沙星的药物敏感率:Uu分别为:89.3%、96.0%、95.1%、90.8%、64.3%、77.8%、17.5%、22.8%、81.3%,Mh分别为:86.0%、80.9%、78.9%、7.7%、0、0、23.2%、14.3%、70%。结论:强力霉素、美满霉素、交沙霉素、克拉霉素对Uu敏感性较好,而克拉霉素、罗红霉素和阿齐霉素对Mh高度耐药。因此,临床用药应根据支原体的种类和药物敏感性进行选择。     

连续6年间鲍曼不动杆菌药物敏感率变迁及对策分析

目的 了解鲍曼不动杆菌的临床分布及药物敏感率变迁,分析其耐药性发展趋势,为临床用药和感染控制提供依据并提出相应对策。方法 收集2006年1月—2011年12月在该院临床微生物科分离得到并有药敏结果的鲍曼不动杆菌共2 397株,分析鲍曼不动杆菌在各科室的分布情况。K-B法检测鲍曼不动杆菌对13种临床常用抗菌药物的敏感率。结果 连续6年间临床分离的鲍曼不动杆菌分布无明显变化,主要分布于烧伤科、心胸外科、普外科、呼吸科、血液科和老年科等科室;对常用抗菌药物的敏感率呈整体下降趋势。门诊及内科分离的菌株对三代头孢、喹诺酮类和氨基糖苷类的敏感率相对较高,而急诊、外科和重症监护病房（ICU）分离的菌株敏感率相对较低。结论 鲍曼不动杆菌对抗菌药物的敏感率逐年降低,需引起临床的高度重视。不同科室分离的细菌耐药谱不一致,临床医师需根据细菌的药物敏感性试验结果合理选用抗菌药物;同时还应加强医院感染监控,减少耐药菌的传播。     

In vitro antimicrobial sensitivity of Mycoplasmas isolated from the bovine genital tract.

The in vitro antimicrobial sensitivity of 14 mycoplasma and 13 ureaplasma strains isolated from the genital tracts of bulls was examined. It was found that at relatively low concentrations, tetracycline, declomycin and tylosin were lethal to both types of organisms. Lincospectin, berenil, streptomycin and erythromycin were lethal to mycoplasmas but were only inhibitory to the ureaplasma strains at the same concentrations. Polymyxin B and novobiocin were ineffective at the levels tested.