鲍曼不动杆菌医院感染危险因素Logistic 回归分析

目的:探讨我院住院病人鲍曼不动杆菌(Acinetobacter baumannii)医院感染的相关因素.方法:前瞻性研究我院2009-2010年住院病人,以病例对照的方法研究其危险因素,并进行多因素分析.结果:共研究2909人,其中鲍曼不动杆菌感染有68人,感染率为2.28%;发病密度为3.42/1000住院日.主要感染部位是呼吸道感染26(38.24%)人、血流感染22(32.35%)人、尿路感染10(14.71%)人、手术部位感染7(10.29%)人、其他部位感染3(4.41%)人.其中对亚胺培南耐药的AB菌感染12(17.65%)人.经Logistic 回归分析动静脉导管、使用鼻胃管、呼吸器、导尿管是主要危险因素.结论:鲍曼不动杆菌医院感染以呼吸道最多,所有鲍曼不动杆菌医院感染与多种侵入性操作密切相关,落实有关侵入性操作的感染控制指南是预防鲍曼不动杆菌感染与播散的重要措施.     

新型抗菌剂研究获进展

正鲍曼不动杆菌耐药已经成为全球性问题。在世界卫生组织公布的对人类健康构成最大威胁的12种抗生素耐药"重点病原体"清单中,耐碳青霉烯类药物的鲍曼不动杆菌位居榜首,引起医学界的强烈关注。鲍曼不动杆菌是致病性革兰氏阴性菌,具有先天存在的耐药基因介导产生先天耐药性,也容易被诱导产生新的耐药性,因而具有多种耐药机制。如何有效应对这些对传统抗生素已产生抵抗的耐药菌是广大医务工作者和科学家亟待解决的重大难题。     

ICU患者下呼吸道感染肺炎克雷伯氏菌的危险因素及对策

总结了ICU肺炎克雷伯氏茵医院感染的特点.包括肺炎克雷伯氏茵的来源、感染率、耐药性及相关危险因素等方面.认为肺炎克雷伯氏茵在ICU患者呼吸道感染中所占比例较高,基础性疾病和各种侵入性操作是肺炎克雷伯氏菌感染的主要危险因素.     

牙鲆鱼肠道鼠李糖乳杆菌P15的分子鉴定与系统发育分析

[目的]对1株分离自健康牙鲆鱼肠道固有菌群的乳杆菌P15进行分子鉴定.[方法]利用PCR技术测定该菌株的16S rRNA基因序列,然后在GenBank中进行相关细菌相应序列的同源性比对,利用MEGA(4.0)软件进行系统发育学分析.[结果]获得了该菌株的16S rRNA基因序列(登录号为 AY852248).菌株P15与鼠李糖乳杆菌(Lactobacillus rhamnosus)的亲缘关系最近.[结论]菌株P15被鉴定为鼠李糖乳杆菌.     

观音土曲乳酸菌的分离与分子鉴定

[目的]指导白酒生产,提高白酒质量.[方法]采用平板分离法从观音土曲中分离到7株乳酸菌(B1～B7),测定其发酵产乳酸的量.选取乳酸产量最高的1株菌B7,提取其DNA并进行16S rDNA的PCR扩增、克隆、测序.从GenBank中选取与B7同源性最高的典型菌株,下载其16S rDNA序列,采用邻位相连法构建进化树.[结果] B1～B7的产乳酸量分别为:24.7、20.7、30.7、15.2、9.5、21.8、35.7 mg/100ml;对B7的基因组DNA进行16S rDNA的PCR扩增,并对纯化后的扩增产物进行TA克隆,阳性克隆经琼脂糖凝胶电泳后在3 000和1 600 bp处出现电泳条带,说明B7的16S rDNA PCR扩增产物已克隆到测序载体上.同源性分析结果表明,B7为乳杆菌属的短乳杆菌.[结论]该研究从观音土曲中分离到1株高产乳酸菌--短乳杆菌.     

一株耐盐芽孢杆菌的分离与鉴定

从校园草坪土壤中分离得到一株能够在20%NaCl的高盐条件下生长的耐盐细菌,经过形态观察、生理特征分析及16SrDNA序列分析,鉴定为一株芽孢杆菌(Bacillus sp.),并在GenBank中完成该菌株16SrDNA序列的注册,登录号为EU167738.     

导管相关感染因素分析

目的:了解我院导管相关感染(CRI)病原菌特点及危险因素,指导临床合理使用留置针.方法:对我院部分科室送检的138例导管培养标本的病原菌进行分析.结果:在138例标本中,共分离出132株病原菌,其中革兰氏阳性菌86株、阴性菌12株及真菌12株.金黄色葡萄球菌、真菌、肠球菌和绿脓杆菌分别在导管留置针培养阳性样本中占15.9%、9.1%、6.82%、3.03%.CRI与留置针的留置时间、操作部位及细菌定植部位有相关性(P＜0.05).结论:CRI的主要病原菌以革兰阳性球菌为主.长时间放置导管、反复插管及插管的不同部位是导致CRI的潜在危险因素,预防重点是避免导管腔内外的污染.     

人参土传病害生防菌株的筛选及抑菌活性研究

[目的]筛选获得对人参土传病害具较好防治作用的生防菌株.[方法]采用稀释平板法和平板对峙培养法从患病人参根际土中分离筛选生防菌,并对菌株进行形态学、生理生化特征和16S rDNA鉴定.[结果]以立枯丝核菌(Rhizoctonia solani)、尖镰孢菌(Fusari-um oxysporum)和腐皮镰孢菌(Fusarium solani)为指示菌株,从黑龙江铁力农场患病人参根际土中筛选获得2株具较强拮抗作用的生防菌株B59和X1,鉴定为枯草芽孢杆菌.2株生防菌对8种不同真菌的抑菌率平均达90%以上,初步研究表明B59和X1菌株可分泌抗菌活性物质.[结论]2株生防枯草芽孢杆菌B59和X1菌株对人参土传病原菌具较强的拮抗作用,具有一定的开发应用潜力.     

耐盐菌的筛选及初步鉴定

[目的]筛选耐盐菌株,为含盐废水的处理提供支持.[方法]以某化工有限公司生产污水为菌株来源,从中分离纯化得到耐盐菌株,通过测定所筛选得到的不同菌株的耐盐度,把不同的菌株接种到生产废水中,摇床培养2d后测COD,通过计算COD去除率确定一株优势菌株,并将其进行基本的生理生化特征测试.[结果]初步鉴定该菌为一株革兰氏阳性细菌,最适生长温度为37℃,最适生长pH值为7.0,NaCI盐浓度为1%时生长情况最好,经驯化培养耐盐度达9%.[结论]该菌株为合格的耐盐菌.     

四川省不同地区猪源大肠杆菌耐药性调查

[目的]了解四川省不同地区猪源大肠杆菌的耐药性.[方法] 采用CLSI推荐的微量肉汤稀释法,对分离自四川各地不同养猪场的232株大肠杆菌对32种抗菌药物的耐药性进行调查.[结果] 232株大肠杆菌除对头孢噻呋、头孢唑啉、头孢曲松和阿米卡星较敏感(耐药率≤15.52%)外,对其余28种药物均表现出不同程度的耐药性(耐药率范围42%～97%);98.7%的菌株表现出多重耐药性;对部分药物,分离自规模化养殖场菌株的耐药性比分离自散养户的菌株严重.[结论]分离菌株对大部分抗菌药物均表现出耐药性.     

Recent data on molecular genetics of neuroendocrine tumors

Between December 1994 and April 1995, a nosocomial outbreak caused by a multi-resistant Acinetobacter baumannii, occurred on a surgical ward in our hospital. The organism was isolated from 13 patients, eight of whom were infected whereas the others were colonized. Twelve isolates were compared by cell envelope protein electrophoretic profiles and AFLP, a recently described DNA fingerprinting method. Both methods indicated that this outbreak was caused by spread of a single strain, which was identified as A. baumannii by amplified ribosomal DNA fingerprinting (ARDRA). A case-control comparison was performed to identify risk factors associated with nosocomial acquisition of A. baumannii. Risk factors for cross-colonization were length of stay, surgery, wounds and treatment with broad-spectrum antibiotics. Cross-infection with A. baumannii among patients occurred despite implementation of stringent infection control measures. The outbreak was controlled after temporary closure of the surgical ward for disinfection purposes. Patients admitted on a general surgical ward colonized or infected with multi-resistant A. baumannii strains should alert the hospital infection control team, and prompt implementation of strict infection prevention measures to prevent further spread is advised.     

Evidence of genomic instability in Campylobacter jejuni isolated from poultry

Poultry isolates of Campylobacter jejuni derived from a survey of meat processing batches were genotyped by pulsed-field gel electrophoresis (PFGE) of chromosomal DNA to establish the clonal relationships between single-colony isolates. In the majority of batches studied, one or two genotype patterns predominated. However, in one batch (batch A), 21 single-colony isolates gave 14 different PFGE genotypes. The banding patterns obtained with SmaI were sufficiently different to distinguish between genotypes, although the patterns also produced many common bands. The question of whether these isolates represented different clones or had a common clonal ancestry was addressed by additional genotypic and phenotypic methods. Restriction length polymorphism of PCR products obtained from the flagellin genes showed an identical flagellin genotype for all of these isolates. In contrast, unrelated control isolates resulted in different flagellin genotypes. Moreover, all 14 different PFGE genotypes of batch A had identical Penner serotypes and identical or similar biotypes and phage types. It was concluded that the isolates were of clonal origin and that the diversity in the PFGE banding patterns had most likely originated from genomic rearrangements. However, the PFGE genotypes were shown to be stable upon subculturing in vitro and after in vivo passage in chickens, and natural transformation between isogenic mutants carrying antibiotic markers did not occur in vivo in a chick colonization model. The possible mechanisms for the hypothesized genomic recombinations and the conditions that allow, induce, or select for such events are discussed.     

"Sniffin'' sticks": screening of olfactory performance

OBJECTIVE: To study the loss of antimicrobial susceptibility in repeat (same patient, same bacterial species, and same site) aerobic gram-negative bacilli (AGNB) isolated from individual patients during their stay in the intensive-care unit (ICU). SETTING: A 792-bed, tertiary-care community hospital with a total of 107 adult, pediatric, and neonatal ICU beds. METHOD: An observational prospective study performed November 1992 through mid-July 1993. RESULTS: Of 594 consecutive AGNB from 287 ICU patients, 117 isolates (20%) from 55 patients (19%) were repeat isolates, with the majority obtained from respiratory secretions (83%). Pseudomonas aeruginosa and Enterobacter species accounted for 61% of the isolates. Forty-two (36%) of the repeat isolates from 24 patients (44%) had > or = 4-fold increase in minimum inhibitory concentration to at least one antibiotic and no longer were considered fully susceptible based on National Committee on Clinical Laboratory Standards criteria. Loss of antimicrobial susceptibility often developed within several (median 8) days and was associated only infrequently with simultaneous transition from colonization to infection in the individual patient. Use of certain beta-lactam antibiotics was associated with increasing resistance to several other antibiotics in the same class. Concurrent use of beta-lactams and aminoglycosides did not prevent loss of antimicrobial susceptibility to the former in repeat isolates. CONCLUSION: We conclude that loss of antimicrobial susceptibility in repeat AGNB isolated from ICU patients is common, usually is not associated with transition from colonization to infection, and often is associated with prior use of antibiotics. Minimizing antibiotic use in ICU patients should help reduce the risk of antimicrobial resistance in repeat AGNB isolates.     

The clinical significance of Acinetobacter species

Of 50 consecutive patients from whom Acinetobacter species were isolated, only one had an infection due to the organism which required antibiotic therapy. Fourteen of the isolates were associated with minor body surface infections and the remainder occurred as the result of either colonization without infection or culture contamination. The taxonomy, natural occurrence and antibiotic sensitivity of Acinetobacter species and their differentiation from more pathogenic organisms are reviewed.     

An outbreak of M serotype 1 group A Streptococcus in a neonatal intensive care unit

OBJECTIVE: To describe the investigation and control of an outbreak of M serotype 1, Streptococcus pyogenes (group A Streptococcus, GAS) infections in a neonatal intensive care unit (NICU). STUDY DESIGN: The study was conducted in an NICU in a large urban university-affiliated hospital. Retrospective review was performed of all infants and health care workers in the NICU, especially those either colonized or infected with GAS during the outbreak and the prospective surveillance period (July through September 1994). Prospective epidemiologic investigation, including cultures of throat, umbilicus, and anorectum (infants), or throat and anus (NICU personnel), identified a possible common source of the disease in case infants. Antimicrobial susceptibility testing and serotyping of all GAS strains were performed; M serotype 1 isolates were examined by DNA analysis with restriction fragment length polymorphism. The M-1 GAS isolates were tested for streptococcal pyrogenic exotoxin (SPE) A and SPE B production. A retrospective chart review and analysis of infants with GAS infection or colonization was conducted. RESULTS: During a 1-week period, two very low birth weight infants more than 3 weeks of age had GAS septicemia and focal infection. Two additional very low birth weight infants with asymptomatic throat colonization were identified during the first week of surveillance. Benzathine penicillin G was administered to all NICU infants, but failed to eradicate throat colonization in the four case subjects. Seven days after completing parenteral antibiotic therapy, the index patient had a recurrence of GAS septicemia that was fatal. Eradication of throat colonization in the remaining three infants was achieved with a 10-day course of intravenous clindamycin therapy. Among 103 NICU personnel, five (4.9%) had asymptomatic GAS colonization with strains that were uniformly susceptible to penicillin. Each colonized adult was successfully treated with oral clindamycin therapy. Serotyping revealed that five isolates of GAS from four infants and one NICU respiratory therapist were M-1 isolates; DNA analysis confirmed that these were the same strain. The five M-1 isolates produced both SPE A and SPE B. CONCLUSIONS: The previously documented increase in prevalence of M-1 strains of GAS in the United States is likely to be associated with their introduction into closed populations including NICUs. Control of such outbreaks may be achieved by isolation, cohorting of case subjects and possible carriers, and successful eradication of colonization in case subjects and carriers. Although GAS organisms are uniformly susceptible to penicillin G, eradication may require agents other than penicillin.     

Low-level colonization and infection with ciprofloxacin-resistant gram-negative bacilli in a skilled nursing facility

BACKGROUND: We report a 1-year surveillance study that evaluates colonization and infection with ciprofloxacin-resistant gram-negative bacilli (CR GNB) and the relation to quinolone use and other possible risk factors in a proprietary skilled nursing facility (SNF) with no history of outbreaks. METHODS: Rectal swabs obtained quarterly were streaked on MacConkey agar with ciprofloxacin discs (5 microg) to screen for CR GNB and later were speciated and the antimicrobial susceptibilities were confirmed by standardized disc-diffusion tests. RESULTS: The mean prevalence of CR GNB colonization was 2.6% (range 0.9% to 5.3%). The colonization frequency was higher in the last survey than it was in the first survey. CR GNB-colonized strains included Pseudomonas species (21%), but more than half were non-Pseudomonas enterics such as Acinetobacter baumannii (25%), Proteus mirabilis (17%), and Providencia stuartii (13%). None of the patients who had colonization with CR GNB had subsequent infections with the same species. Patients with colonization had more exposure to ciprofloxacin and they were more likely to have been recently admitted from an acute-care hospital and have decubitus ulcers. During the study period, of 336 patients surveyed, 98 (29%) patients developed suspected infections and cultures were done; the infection rate was 4.7 per 1000 patient days. Of these infected patients, 59 (60%) were infected by GNBs; the infection rate was 2.3 per 1000 patient days. Nineteen percent of the GNB infections were treated with a quinolone. (Overall, quinolones constituted about 17% of antibiotic usage in the SNF). Only 3 (5%) of the patients infected with GNB were infected with CR GNB, including Pseudomonas and Providenci a species. The CR GNB infections involved multiple sites, multiple organisms, and long length of stay in the SNF. CONCLUSIONS: The findings indicate that in this community SNF, a low frequency of colonization or infection with CR GNB existed. Whether continued moderate use of quinolones will lead to increasing levels of CR GNB will require further study.     

The electroretinogram in chronic renal failure

Fifty-nine enterococci isolated from 18 patients in an intensive care unit (ICU) and 21 patients in general wards (GW) at Royal Perth Hospital (RPH) during a period of 14 months were examined for antibiotic resistance by susceptibility testing and DNA polymorphism by pulsed-field gel electrophoresis. The study showed that penicillin-resistant Enterococcus faecium is a common nosocomial isolate in ICU. The DNA patterns of various strains of E. faecium and E. faecalis were closely related in most consecutive isolates from the same patients but were generally different for isolates from different patients. Thirty two different DNA patterns were identified for 59 isolates from 39 patients. Identical or similar DNA patterns were also identified for some isolates from different patients, suggesting that cross-infection had occurred between patients in ICU and GW. These data suggest that cross-infection occurred more commonly in ICU than in GW and are consistent with the known higher risk of ICU patients for nosocomial infection.     

Medically sound, cost-effective treatment for pelvic inflammatory disease and tuboovarian abscess

OBJECTIVE: Our purpose was to determine the clinical effectiveness and cost-effectiveness of three antibiotic regimens for the treatment of pelvic inflammatory disease and tuboovarian abscess. STUDY DESIGN: A review of all patients' hospitalized at Hutzel Hospital, Detroit, Michigan, for treatment of pelvic inflammatory disease and tuboovarian abscess between Jan. 1, 1993, and April 30, 1997, was performed. Demographic data, antibiotic choices, changes in therapy, operative interventions, and cost of therapy were assessed. RESULTS: Two hundred three patients were admitted for treatment of pelvic inflammatory disease during the study period. We were able to evaluate the clinical efficacy of antibiotic treatment in 179 patients, including 105 patients with pelvic inflammatory disease alone (uncomplicated pelvic inflammatory disease) and 74 women whose infection was complicated by tuboovarian abscess. The three antibiotic regimens evaluated were cefotetan plus doxycycline, clindamycin plus gentamicin, and ampicillin plus clindamycin plus gentamicin. All regimens demonstrated comparable efficacy in treating uncomplicated genital tract infections. Ampicillin plus clindamycin plus gentamicin was significantly better than clindamycin plus gentamicin and cefotetan plus doxycycline in treatment of tuboovarian abscess (p = 0.001). Fifteen women with tuboovarian abscess responded to a change to ampicillin plus gentamicin plus clindamycin antibiotic therapy alone. The hospital stay was prolonged by approximately 3 days in women failing to respond to initial antibiotic therapy, and operative interventions were common in this group of patients. CONCLUSIONS: Cefotetan plus oral doxycycline is the most cost-effective regimen for treating uncomplicated pelvic inflammatory disease, whereas triple-antibiotic therapy is the treatment of choice in women with tuboovarian abscess.     

Proliferative activity and micronucleus frequency after radiation of lung cancer cells as assessed by the cytokinesis-block method and their relationship to clinical outcome

Patients and gonococcal isolates (n = 783) from five sexually transmitted disease clinics in Ohio and western Pennsylvania were studied to investigate the spread of gonococci with decreased fluoroquinolone susceptibility. Among patients with gonorrhea, rates of infection with strains with decreased fluoroquinolone susceptibility (MIC of 0.125-0.25 microg ciprofloxacin/mL) were 20% for Cleveland, 9% for Akron, 7% for Columbus, 1% for Toledo, and 0.5% for Pittsburgh. Persons infected with strains with decreased susceptibility were more likely than those with susceptible strains to be male and older; no significant differences in sex behaviors, residence of sex partners, or recent antibiotic use were detected. Prevalence of decreased susceptibility was not correlated with reported levels of community fluoroquinolone use. The Pro/IB-3 auxotype/serovar class accounted for 80% (44/55) of isolates with decreased susceptibility. Pro/IB-3 isolates from three cities had indistinguishable pulsed-field gel electrophoresis patterns, suggesting intercity spread of a clone.