呼吸道感染常见致病菌及耐药性分析

目的:调查导致呼吸道感染的主要致病菌的种类,及这些致病菌对我科常用抗生素的药敏性情况,为呼吸道感染的合理用药提供依据.方法:对680个样本进行分离培养,用全自动微生物分析仪-VITEK32进行菌种鉴定及抗生素的药敏实验.结果:共分离获得1484株主要致病菌,其中G 致病菌706株,占总量的47.6%,G-致病菌686株,占总量的46.2%,真菌92株,占总量的6.2%.G 致病菌对检测10种抗生素的药敏性主要表现为传统的抗生素的疗效普偏低;而G-致病菌对检测的抗生素10种的药敏性情况表现出多元化态势.结论:呼吸道感染常见致病菌的种类多样,且表现出较高能力的耐药性,这值得我们注意.     

235例泌尿系统感染的病原菌分布及药敏分析

目的:了解本地区泌尿系统感染的病原菌分布情况,指导临床合理使用抗生素.方法:细菌鉴定及药敏试验采用VITEK-60全自动细菌鉴定仪.结果:革兰阴性菌是本地区泌尿系统感染的主要致病菌70.64%(166/235),其中大肠埃希菌占革兰阴性菌的66.87%(111/166),其次为克雷伯菌属10.84%(18/166).主要致病革兰阳性菌以葡萄球菌为主38.7%(24/62).革兰阴性菌对环丙沙星、左氧氟沙星和甲氧苄啶/磺胺甲恶唑耐药率高,革兰阳性菌对氨苄西林/舒巴坦、环丙沙星和甲氧苄啶/磺胺甲恶唑等 8种抗生素耐药率均偏高.治疗首选万古霉素、呋哺类、利福平等抗生素.结论:大肠埃希菌是本地区泌尿系统感染的主要病原菌.细菌对多种抗生素耐药,建议临床根据药敏结果使用抗生素.     

抑菌生的药物敏感试验

本文检测了BS_(224)菌对21种抗生素的药敏情况。结果,除对林可霉素、链霉素呈中度敏感外,其余均敏感,说明BS_(224)菌是抗生素敏感菌。     

748株病原菌的耐药性分析

近年来 ,随着多种抗生素的更新换代以及临床上的用药不合理使用 ,医院感染的病原菌及其对抗生素的耐药性不断上升 ,为了减少耐药性的发生 ,提高疾病治愈率 ,我们统计1999～ 2 0 0 1年间除粪便外的临床标本共检出 74 8株病原菌 ,并对检出菌株进行了耐药性分析。1　材料与方法1.1　菌株来源　从本院 1999～ 2 0 0 1年期间的住院及门诊患者分离所得。1.2　细菌鉴定和药敏试验1.2 .1　细菌鉴定　按法国生物梅里埃 API鉴定系统鉴定。1.2 .2　药敏试验　采用 K - B法 ,使用 MH培养基 ,抗生素购自北京天坛生物制品检定所 ,操作按美国临床实验室…     

我中心儿童医院2006年抗生素用药频度与耐药现状分析

目的:分析我中心儿童医院抗生素的应用情况.方法:统计我中心儿童医院2006年抗生素用药频度(DDDs)排序前15位及其用药金额排序和日用金额,并通过药敏实验对部分抗生素进行耐药分析.结果:DDDs排序前三位分别是头孢克洛、头孢呋辛钠和阿莫西林片;经测定的部分抗生素耐药严重.结论:抗生素的消费总体按照安全、有效、合理、经济的方向发展,临床应严格掌握使用适应证,避免滥用.     

MicroScan AS-4微生物分析仪在室间质控中的应用

目的:通过质控菌株了解MicroScan AS-4微生物分析仪在细菌鉴定中的准确率及与药敏靶值的符合程度.方法:用AS-4微生物分析仪对质控菌株及药敏进行鉴定,并同时用K-B法进行药敏鉴定.结果:51株质控菌株准确率为88.2%(45/51),差异有显著性(x2=6.38,P＜0.05).用微生物分析仪和K-B法做药敏,结果与药敏靶值准确率分别为96.9%(x2=0.032,P＞0.05)、92.7%(x2=0.228,P＞0.05),差异无显著性.微生物分析仪与K-B法药敏差异元显著性(x2=0.062,P＞0.05).结论:只要严格按照操作规定进行操作,结果的符合程度还是比较高的,尤其是抗生素种类多,并能提示最低抑菌浓度、诱导酶、β-内酰胺酶、超广谱β-内酰胺酶,为临床准确选用抗生素提供了重要依据.但AS-4微生物分析仪、不能用于革兰用阳性杆菌的鉴定,真菌鉴定结果欠理想.药敏稀释浓度较少,与美国临床实验室标准化委员会规定的MIC断点低一个浓度,容易人为造成耐药率相对偏高.     

301株铜绿假单胞菌的分布及耐药性分析

目的 通过对临床中分离的铜绿假单胞菌的分布及对临床常用13种抗生素的耐药性进行分析指导临床合理用药.方法 收集大连医科大学附属第二医院2010年1月至12月临床送检的标本,采用全自动细菌和药敏分析仪分离铜绿假单胞菌同时进行药敏试验.结果 铜绿假单胞菌在痰液标本中分离率高达79.06％;对头孢噻肟、头孢西丁、头孢唑啉3种药物的耐药率均大于50％;对头孢他啶,哌拉西林/他唑巴坦耐药率低于20％.结论 铜绿假单胞菌易产生多源耐药,加强耐药性监测,控制医院内感染,对临床医生选用有效的抗生素具有十分重要的意义.     

VITEK－IMSGNS系列药敏卡对~（162）株绿脓杆菌的药敏分析

本文就临床标本中分离的１６２株绿脓杆菌,用ＶＩＴＥＫ－ＩＭＳ全自动微生物系统的ＧＮＳ－ＰＡ等四种药敏卡,共测定２３种抗生素药敏试验．该菌对亚胺硫霉素的敏感度（敏感和中度敏感）最高９７．７８％,其次是哌拉西林、替卡西林、丁胺卡那霉素、妥布霉素、环丙氟哌酸、头孢他啶和头孢哌酮,复方新诺明等八种抗生素耐药率均在９０％以上。分析该菌对１０种抗生素药敏结果发现,几种常用抗绿脓杆菌药物的最小抑菌浓度（ＭＩＣ）值普遍增高,并结合绿脓杆菌生物微膜形成和该菌对β－内酰胺类抗生素抗性机制作了讨论。     

合理使用抗生素的几点体会

随着我国改革开放的不断深入发展 ,抗生素及其新药广泛应用于临床 ,不合理处方也随之增加 ,要想降低耐药细菌增长率 ,延长有效抗生素的使用寿命 ,必须合理应用 ,防止和避免滥用。1　选择对病原体高度敏感的抗生素药物　　细菌学资料对抗生素的选择具有指导意义。但在多数情况下 ,特别是急性感染患者 ,难以及时得到细菌培养及药敏的实验结果。因此 ,主管医生应对各种致病菌的好发部位、临床表现、细菌对抗生素的敏感度及其耐药性发展规律有所了解 ,在未获得准确检验结果或不能做药敏试验的情况下 ,也能作出基本正确的判断与处理。有些缺乏经…     

耐青霉素肺炎链球菌下呼吸道感染的临床和药敏分析

目的：探讨耐青霉素肺炎链球菌下呼吸道感染的诊断和治疗。方法：分析患者的临床表现和痰培养药敏。结果：临床表现与青霉素敏感的肺炎链球菌感染相同,药敏提示有相当部分的菌株对1种或多种抗生素耐药,敏感抗生素依次为;万古霉素,氧氟沙星,头孢氨噻污。结论：无论临床还是实验室都应将肺炎链球菌的青霉素耐药株和敏感株严格区分;选用敏感抗生素治疗。     

BioTimer Assay, a new method for counting Staphylococcus spp. in biofilm without sample manipulation applied to evaluate antibiotic susceptibility of biofilm

The medical device-related infections are frequently a consequence of Staphylococcus biofilm, a lifestyle enhancing bacterial resistance to antibiotics. Antibiotic susceptibility tests are usually performed on planktonic forms of clinical isolates. Some methods have been developed to perform antibiotic susceptibility tests on biofilm. However, none of them counts bacterial inoculum. As antibiotic susceptibility is related to bacterial inoculum, the test results could be mistaken. Here, a new method, BioTimer Assay (BTA), able to count bacteria in biofilm without any manipulation of samples, is presented. Moreover, the BTA method is applied to analyze antibiotic susceptibility of six Staphylococcus strains in biofilm and to determine the number of viable bacteria in the presence of sub-inhibitory doses of four different antibiotics. To validate BTA, the new method was compared to reference methods both for counting and antibiotic susceptibility tests. A high agreement between BTA and reference methods is found on planktonic forms. Therefore, BTA was employed to count bacteria in biofilm and to analyze biofilm antibiotic susceptibility. Results confirm the high resistance to antibiotics of Staphylococcus biofilm. Moreover, BTA counts the number of viable bacteria in the presence of sub-inhibitory doses of antibiotics. The results show that the number of viable bacteria depends on sub-inhibitory doses, age of biofilm and type of antibiotic. In particular, differently to gentamicin and ampicillin, sub-inhibitory doses of ofloxacin and azithromycin reduce the number of viable bacteria at lower extent in young than in old biofilm. In conclusion, BTA is a reliable, rapid, easy-to-perform, and versatile method, and it can be considered a useful tool to analyze antibiotic susceptibility of Staphylococcus spp. in biofilm.     

ESBL-positive and ESBL-negative Klebsiella pneumoniae and Klebsiella oxytoca strains--occurrence in clinical specimens and susceptibility to selected antibiotics

The aim of this study was to evaluated susceptibility to selected antibiotics and occurrence in clinical materials ESBL-positive and ESBL-negative K. pneumoniae and K. oxytoca strains. The susceptibility to selected antibiotics were tested by disk-diffusion method. None of the analysed strains was resistant to imipenem. Among non beta-lactam antibiotics thwe most strains were susceptible to fluoroquinolones. The most frequently K. pneumoniae strains were isolated from urine, K. oxytoca trains were isolated from wounds.     

Effect of peptide antibacterial factor and changes in Staphylococcus susceptibility to antibiotics]

The susceptibility to antibiotics of the Staphylococcus epidermidis cells in the presence of low-molecular weight peptide factor was investigated. The factor was isolated from the Styaphylococcus warneri culture media. The factor enhanced the S. epidermidis susceptibility to ampicillin, chloramphenicol, lincomycin, rifampicin, tetracycline, cefalexine, erythromycin and fusidine. The same effect was demonstrated for the cells of S. epidermidis resistant to cadmium ions along with resistance to several antibiotics. However the cells reaction in this case was expressed to a lower extent. It was suggested that revealed alterations in staphylococci susceptibility to antibiotics was due to the peptide factor effect on cytoplasmic membrane permeability that resulted in nonspecific increase in accumulation of various compounds with low-molecular weight.     

Influence of testing conditions on the susceptibility results of Staphylococcus cohnii to beta-lactams

The high occurence of coagulase-negative staphylococci among bacteria responsible for hospital infections is unquestioned. Studies on the poorly-known novobiocin-resistant, coagulase-negative Staphylococcus cohnii were undertaken. The possibilities of optimizing conditions for determination of susceptibility to beta-lactam antibiotics of this species were researched. In the case of S. cohnii the new cefoxitin test for detection of methicillin resistant strains, introduced by the National Reference Centre for Antibiotics in Poland was found as a good and of credible quality. It was also shown, that application in in vitro examination conditions stimulating the mechanisms of resistance to beta-lactam antibiotics, supplies credible results relating to their true susceptibility. The necessity of establishing individual conditions for susceptibility determination in different species of coagulase-negative staphylococci was suggested.     

Rapid determination of Proteus mirabilis susceptibility to antibiotics using infrared spectroscopy in tandem with random forest

Bacterial infections cause serious illnesses that are treated with antibiotics. Currently used methods for detecting bacterial antibiotic susceptibility consume 48–72 h, leading to overuse of antibiotics. Thus, many bacterial species have acquired resistance to a broad range of available antibiotics. There is an urgent need to develop efficient methods for rapid determination of bacterial susceptibility to antibiotics. The combination of machine learning and Fourier-transform infrared (FTIR) spectroscopy has generated a promising diagnostic approach in medicine and biology. Our main goal is to examine the potential of FTIR spectroscopy to determine the susceptibility of urinary tract infection-Proteus mirabilis to a specific range of antibiotics, within about 20 min after 24 h culture and identification. We measured the infrared spectra of 489 different P. mirabilis isolates and used random forest to analyze this spectral database. A classification success rate of ~84% was achieved in differentiating between the resistant and sensitive isolates based on their susceptibility to ceftazidime, ceftriaxone, cefuroxime, cefuroxime axetil, cephalexin, ciprofloxacin, gentamicin, and sulfamethoxazole antibiotics in a time span of 24 h instead of 48 h.     

Effect of subinhibitory levels of selected antibiotics on susceptibility of Staphylococcus aureus strains to phagocytosis and killing by rabbit granulocytes

The aim of the study was to assess the of chosen antibiotics in subinhibitory concentrations (sub-MIC) on the sensitive of Staphylococcus aureus cells to phagocytosis and killing by rabbit granulocytes. The following antibiotics were used: cloxacillin, cefadroxil, cefuroxim, cefotaxim, gentamicin, netilmicin, lincomicin, doxycycline and riphamicin. A total of 144 S. aureus strains with varied sensitivity to these antibiotics were selected for the study. The experiment used granulocytes isolated from rabbit blood and S. aureus strains incubated for 18 h in TSB broth containing antibiotics in the concentrations of 0.1 MIC, 0.2 MIC and 0.5 MIC, and in the antibiotics-free medium. Phagocytosis was assessed by the method of differential staining with acridine orange and crystal violet, allowing simultaneous determination of phagocytised and killed S. aureus cell counts. The findings revealed that the culture of S. aureus in the presence of all the antibiotics used in subinhibitory concentrations increased significantly the susceptibility of most S. aureus strains to phagocytosis and killing by granulocytes. The above effect usually occurred in the concentrations of 0.1 MIC (54.2%), more seldom in 0.2 MIC (13%) and 0.5 MIC (15% of strains). Each group of S. aureus contained some which showed no change in susceptibility following culture with the chemotherapeutic agents in subinhibitory concentrations (26.3%). Insensitive strains to the subinhibitory effects were equally common among susceptible (27%), intermediate (23%) and resistant (26%) strains of S. aureus to the antibiotics used. No statistically significant reduction was noted in phagocytosis or killing by rabbit granulocytes. No correlation was observed between the susceptibility to the subinhibitory effects of the antibiotics involved and their biochemical mechanisms.     

少见贪铜菌感染1例

目的 报道1例由罕见细菌导致的感染病例,并分析其易感因素及药敏情况,为罕见细菌感染治疗提供临床经验。方法 收集该患者临床信息,包括症状、治疗过程、药敏试验结果等。结果 药敏试验显示该少见贪铜菌对大部分头孢类、碳青霉烯类等抗生素均敏感。结论 少见贪铜菌是比较罕见的条件致病菌之一,感染多发生于免疫力低下患者。     

Impact of exogenic proteolytic enzymes on bacteria]

The impact of papain, trypsin and the enzyme complex vobenzyme on formation of biofilms by grampositive and gramnegative bacteria was studied. The enzymes were shown to inhibit the biofilm formation. When applilied to the formed associations, the enzymes potentiated the effect of antibiotics on the bacteria located in them. An increase in the antimicrobial effect of various nonrelated antibiotics was not connected with a change in the bacteria susceptibility but likely resulted from higher bioavailability of the drugs in the presence of the enzymes.     

Rapid Increase of Pneumococcal Resistance to β-Lactam and Other Antibiotics in Isolates from the Respiratory Tract (Nagasaki,Japan: 1975–1994)

The susceptibility of 101 pneumococcal isolates from the respiratory tract during 1991–1994 was examined and compared with the susceptibility of isolates over the period of 1975–1990. A rapid increase of resistance was seen not only to penicillin but also other antimicrobial agents. During 1991–1994, 38% of all the isolates were resistant to penicillin. The rates of resistance during this period were 16–23% for three newer cephalosporins, 18% for imipenem, 69% for tetracycline, 31% for erythromycin, 20% for chloramphenicol and 9% for clindamycin. The use of antibiotics within one month prior to pneumococcal isolation was correlated with penicillin resistance (P < 0.05). Serotyping of the isolates by antiserum revealed differences in predominant types between penicillin-resistant (19F, 23F, 4) and -susceptible isolates (15, 4, 11A). Our data suggests that anti-pneumococcal antibiotics should be carefully chosen on the basis of susceptibility tests.