Characteristic features of etiology and antibiotic susceptibility of urinary tract infection pathogens in patients with diabetes mellitus]

Patients with diabetes mellitus and urinary tract infection were examined. The structure of the pathogens and their antibiotic susceptibility were investigated. Escherichia coli was shown to be the main pathogen of urinary tract infections in the patients with diabetes mellitus. The highest activity against the E. coli isolates was revealed in amoxycillin/clavulanate (92% of the susceptible strains), the 3rd and 4th generation cephalosporins, carbapenems, amikacin (100%) and fluoroquinolones (96%). At the same time the isolates were resistant to aminopenicillins and co-trimoxazole (29.3 and 16% respectively).     

Efficacy of various antimicrobial agents in the treatment of epidemic typhoid fever]

During superepidemic of a typhoid fever in Tadjikistan the efficiency of application in clinics and of 14 antimicrobial agents representing almost all basic chemical classes was investigated. Remarkable variation of frequency and type of S. typhi resistance to these preparations up to epidemic and especially in its process was demonstrated. The absence of absolute (100%) efficacy of the investigated agents in vivo and in vitro was shown. The reasons of low efficacy of etiotropic treatment of the patients with typhoid fever are analysed.     

Sensitivity to cephalosporin antibiotics of infectious causative agents in surgery

Comparison of antimicrobial effects of cephalosporins of the 1st and 2nd generations showed that the latter were advantageous with respect to gram-negative bacteria causing surgical infections. Three cephalosporins of the 3rd generation were characterized by the highest activity against such bacteria, including Enterobacter spp. and indole positive strains of Proteus spp., as well as non-enzymatic bacteria. The antimicrobial spectra and MICs of the new cephalosporins with respect to the cultures isolated from surgical patients were different which requires in vitro sensitivity assay of each antibiotic.     

Characteristics and clinical value of extended-spectrum beta-lactamases]

The literature data and the findings of the authors' studies on the role of extended-spectrum bata-lactamases (ESBL) in providing the clinical effect in the treatment of infections due to ESBL-producing organisms were analyzed. The analysis allowed to consider the NCCLS recommendations not sufficiently valid. According to these recommendations the ESBL-producing organisms (among E. coli and Klebsiella spp.) should be regarded as resistant to penicillins, cephalosporins and aztreonam. Susceptibility of 62 Enterobacteriaceae strains that were isolated in 4 therapeutic centres of Tomsk, Nazran and Moscow and proved to be ESBL-producing organisms was tested and it was shown that the 3rd and 4th generation cephalosporins could not be referred to a homogenous group. The same was confirmed by the prospective and retrospective investigations of a multiprofile hospital on the clinical and bacteriological efficacies of the 3rd generation cephalosporins and cefepime in the treatment of hospital-acquired infections due to Enterobacteriaceae strains producing ESBL.     

Microbiological evaluation of differences between cephalosporins of second and third generations in general hospital]

The aim of the current investigation was to evaluate practical impact of modern NCCLS recommendations for the selection of 2nd and 3rd generation cephalosporins in Moscow teaching multi profile hospital. The sensitivity of clinically significant 96 strains from patients with pyelonephritis and 180 strains from patients with lower respiratory tract infections (pneumonia, COPD) was compared for cefuroxime and cefotaxime or ceftriaxone according NCCLS recommendations during 2000-2001 years. At the lower respiratory tract infection total sensitivity of all pathogens was 70.6% and 72.8%, at the pyelonephritis 71.9% and 76.0% for 2nd and 3rd generations respectively. The differences between cephalosporins were not statistically significant. Based on the application of modern NCCLS recommendations in the routine microbiological practice similar clinical efficacy of 2nd and 3rd generations cephalosporin in lower respiratory tract infections and pyelonephritis could be predicted.     

Typhoid fever: facing the challenge of resistant strains

The introduction of chloramphenicol in 1948 revolutionised the outcome of typhoid fever but chloramphenicol-resistant strains of Salmonella enterica serotype Typhi were reported just two years later. Resistance followed also the introduction of ampicillin and co-trimoxazole. During the second half of the 1980s, strains resistant to the three first-line antimicrobial agents, chloramphenicol, ampicillin and co-trimoxazole emerged and spread rapidly throughout the Indian subcontinent and South East Asia. During the 1990s when fluoroquinolones had become a first-line treatment for typhoid fever, these multi drug resistant (MDR) strains acquired an additional resistance to nalidixic acid with decreased susceptibilities to ciprofloxacin (CIPDS) (MIC range, 0.125-1 mg/l). Considerable data have now accumulated to suggest that infections due to CIPDS strains may not respond satisfactorily to therapy with ciprofloxacin or ofloxacin. Furthermore, identification of such CIPDS strains in clinical laboratories is not easy without determination of MIC of ciprofloxacin. Recently, several isolates highly resistant to ciprofloxacin or to extended-spectrum cephalosporins of Asian origin have been reported.     

Sensitivity of antibiotic-resistant strains of Salmonella to new antibiotics and chemotherapeutic agents]

One hundred and sixty two antibiotic resistant strains of Salmonella isolated within 1984-1988 in Leningrad and the Leningrad Region were tested with respect to their sensitivity to new antibiotics and chemotherapeutics developed or being developed in the USSR. At the background of high numbers of circulating Salmonella strains resistant to the routinely used antibiotics such as doxycycline, streptomycin and gentamicin they appeared to be highly sensitive to amikacin, ciprofloxacin, pefloxacin and the 3rd generation cephalosporins i.e. ceftazidime and cefotaxime as well as to thienamycin. These modern antibacterial agents are possibly to be the drugs of choice in etiotropic treatment and chemoprophylaxis of septic acute intestinal infections due to Salmonella strains with multiple resistance. Resistance of individual Salmonella strains to cefotaxime and ceftazidime indicated that it was possible to use their property for additional labeling of the pathogens within a serological type of Salmonella while conducting epidemiological examinations during outbreaks of acute intestinal infections of Salmonella etiology.     

Susceptibility and molecular mechanisms of resistance to cephalosporins of Escherichia coli strains isolated from patients with nosocomial infections

Resistance to wide spectrum of antibiotics was studied and most widespread genetic determinants of resistance to beta-lactam antibiotics were revealed. Susceptibility testing was performed using serial broth microdilution method. Detection of class A expanded spectrum beta-lactamases genes (TEM, SHV, CTX) by polymerase-chain reaction method was performed in 90 strains. Carbapenems remained the most active antibacterial agents with respect to studied E. coli strains. Among the 3rd generation cephalosporins the lowest minimal inhibitory concentrations were observed for inhibition-protected combined agents (ceftazidime/clavulanic acid and cefoperazone/ sulbactam). Alone or in various combinations TEM, SHV, and CTX types of beta-lactamases were found in 58.9%, 14.4%, and 77.8% of strains. Combinations of 2 determinants were detected in 55.6% of the isolates, and all 3 determinants--in 5.6%. Most often E. coli was isolated in patients with urinary tract infections. Carbapenems and inhibition-protected combined 3rd generation cephalosporins are the most active agents against E. coli.     

Antimicrobial resistance and production of beta-lactamases in Bulgarian clinical isolatesMoraxella catarrhalis

One hundred and fifteen strains ofMoraxella catarrhalis from inpatients and healthy children were collected from 2000 to 2005. MICs to 17 antimicrobial agents from different groups were determined. High resistance rate to penicillin G, aminopenicillins and first generation cephalosporins (98.26%) was found. Susceptibility to cefuroxime, cefotaxime and ceftriaxone was from 86.08 to 97.40%. AllM. catarrhalis strains were susceptible to aminopenicillin/inhibitor combinations, ceftazidime, ceftibuten, ciprofloxacin and gentamicin. The susceptibility rates to azithromycin, clarithromycin, tetracycline and trimethoprim/sulfamethoxazole were reduced in range of 6–9%. Presence ofbro1 orbro2 genes was revealed in 113M. catarrhalis strains by PCR. The overall prevalence of the BRO-1 and BRO-2 enzymes was 92.92 and 7.08% respectively. MICs of Penicllin were significantly higher inbro1 positive isolates.     

成人与儿童下呼吸道标本病原菌分布差异的比对与耐药性分析

目的调查研究温州市中西医结合医院温州市儿童医院成人与儿童病区下呼吸道标本病原菌的分布差异与抗生素耐药性分析。方法对2010年7月至2011年6月的所有成人与儿童下呼吸道感染患者的临床标本（痰,咽拭）进行微生物检验并统计分析。结果成人感染以非发酵细菌为主,并且出现MDR/PDR现象;儿童细菌性感染以肠杆菌细菌为主;G＋菌感染还是以金黄色葡萄为主,也有MRSA菌株出现,未超过15%,远远低于成人水平。铜绿假单胞菌检出率占成人下呼吸道感染的首位,头孢三、四代对成人铜绿假单胞菌耐药性在50%左右;阿米卡星有很好的敏感性,耐药率为5.2%;头孢哌酮/舒巴坦的耐药率已达20.59%;碳青霉烯类抗生素的耐药率在50%左右。成人鲍曼不动杆菌只有米诺环素、头孢哌酮/舒巴坦有较好的敏感性,耐药率在10%左右;并且已经出现全耐药菌株。儿童检出病原菌中对头孢哌酮/舒巴坦、碳青霉烯类抗生素未发现耐药菌株,对头孢三、四代仍有较好的敏感性,还没出现高耐菌株。头孢三、四代对成人肺炎克雷伯菌耐药性已高达75%左右;头孢哌酮/舒巴坦、碳青霉烯类抗生素的耐药率将达20%。儿童中MRSA检出率为13.32%,成人已高达72.15%,未发现对万古霉素、替考拉宁、利那唑胺耐药菌株。结论儿童与成人在下呼吸道感染病原菌分布与耐药性存在明显差异。应杜绝滥用抗生素,做到有的放矢。     

Neuroinfections due to Listeria monocytogenes

Listeria monocytogenes is not a rare pathogen causing meningitis, mainly in small children and in close contacts to livestock. The pathogen is naturally resistant to cephalosporins and some glycopeptides as well, therefore despite of syndromologic diagnosis of meningitis and initial therapy with 3rd generation cephalosporins according to the guidelines therapeutic failures with clinical consequences may occur.     

Opportunistic Pathogens and Elements of the Resistome that Are Common in Bottled Mineral Water Support the Need for Continuous Surveillance

Several differences concerning bacterial species, opportunistic pathogens, elements of the resistome as well as variations concerning the CFU/mL counts were identified in some of the five most marketed bottled mineral water from Araraquara city, São Paulo, Brazil. Two out of five brands tested were confirmed as potential source of opportunistic pathogens, including Mycobacterium gordonae, Ralstonia picketti and Burkholderia cepacia complex (Bcc). A total of one hundred and six isolates were recovered from four of these bottled mineral water brands. Betaproteobacteria was predominant followed by Alphaproteobacteria, Gammaproteobacteria and Firmicutes. Ninety percent of the bacteria isolated demonstrated resistance to seventeen of the nineteen antimicrobials tested. These antimicrobials included eight different classes, including 3rd and 4th generation cephalosporins, carbapenems and fluoroquinolones. Multidrug resistant bacteria were detected for fifty-nine percent of isolates in three water brands at counts up to 10³ CFU/ml. Of major concern, the two bottled mineral water harboring opportunistic pathogens were also source of elements of the resistome that could be directly transferred to humans. All these differences found among brands highlight the need for continuous bacteriological surveillance of bottled mineral water.     

Concerning the sensitivity of Acinetobacter calcoaceticus

The strains of Acinetobacter calcoaceticus, var. anitratus (A. c. a.) were isolated in the nosocomial environment as an opportune pathogen. The therapy of choice may be determined after in vitro tests. Our results show following therapeutical possibilities: beta-lactam antibiotics--cephalosporins of IIIrd generation (cefotaxime), also combinations of antimicrobials have shown good results: amoxycillin or ticarcillin with clavulanic acid. Best synergistic effect was found in combination ticarcillin-amikacin.     

Annual trends in antibiotic resistance of nosocomial Acinetobacter baumannii strains and the effect of synergistic antibiotic combinations

Acinetobacter baumannii is becoming increasingly resistant to antibiotics often requiring combination therapy. Annual changes of resistance to selected antimicrobials of 150 A. baumannii strains, isolated as nosocomial pathogens between 1994 and 2000 were investigated. The synergistic effects of antimicrobials were studied using a microdilution checkerboard technique in eight selected isolates resistant to third-generation cephalosporins and beta-lactam/beta-lactamase inhibitor combinations and to at least one aminoglycoside. Rates of resistance of cefepime, ceftazidime, ampicillin/sulbactam, amikacin and ciprofloxacin (before 1996 and between 1996-2000) were 29.7% - 72.6, 37.8% - 81.4%, 35.1% - 72.6%, 8.1% - 56.6%, 5.4% - 46.0% respectively (p < 0.001 for each one). Synergy was observed in at least one of the combinations of antibiotics from seven of eight isolates (87%), no antagonism was detected with any combination. Ceftazidime-amikacin (50%) and ampicillin/sulbactam-tobramycin (50%) were the most effective combinations. Due to the effectiveness of sulbactams to Acinetobacter, ampicillin/sulbactam-tobramycin combination is recommended as the first line of choice.     

棉铃虫种群能量动态及其为害特征分析

根据棉铃虫种群数量密度、年龄结构、存活率及虫体含能量,系统地分析了８种不同类型棉田生态系统中棉铃虫种群生产力、摄入量及其为害特征．结果表明,棉铃虫种群的能量生产主要集中于第３代;其所引起棉花繁殖器官的被害量在第２、３、４代分别为１１．８３、１６．６５和９．５２个·ｍ－２．随着播种期的推后,２代棉铃虫种群生产力和摄入量减少,３、４代值增加．实行套作种植使２、４代值减少,而３代值增加．棉铃虫种群摄食利用效率随世代增加而减小,其净生态效率以第３代最高,第４代居中,第２代最小．由此进一步探讨了不同时空类型棉田棉铃虫各代管理的对策．     

Comparative evaluation of activity of antibacterial agents in vitro and their efficacy in experimental cholera due to strains of Vibrio cholerae O1 and O139 serogroups in albino mice]

Activity of 16 antibacterial agents against human isolates of Vibrio cholerae O1 and O139 serogroups (P-5879, 4990, 143/23, and MO-45, P- 16065 respectively) was studied in vitro. The efficacy of the agents was studied in a model of generalized cholera in albino mice. Susceptibility of Vibrio cholerae P-5879 (used as the control) in the in vitro experiments with respect to the antibacterial agents correlated with their in vivo efficacy. The strains of Vibrio cholerae O1 and O139 serogroups isolated within the recent years had transmissive markers of resistance to streptomycin, trimethoprime/sulfamethoxazole, tetracycline, chloramphenicol and not transmitted by conjugation markers of resistance to rifampicin, furazolidone, nalidixic acid. The specific feature of the experimental infection due to such strains was the failure not only of the antibacterials of the resistance spectrum of the pathogen but also of the antibiotics showing in vitro susceptibility (betalactams, fluoroquinolones) that required additional bacteriological control on the 2nd or 3rd day of the etiotropic therapy for early replacement of the antibacterial agent.     

Antimicrobial susceptibility of anaerobic bacteria in Bulgaria

ObjectivesThe antimicrobial susceptibility of anaerobic bacteria isolated from clinical specimens in the referent for Bulgaria anaerobic laboratory was studied in a period of 25 years/1983–2007/.MethodsNCCLS – recommended agar dilution methods were used. β-lactamase activity was determined with nitrocefin discs.ResultsThe 29 antimicrobial agents included in the study were divided according to their in vitro activity against the anaerobic isolates into 4 main groups for guiding empirical treatment: 1st group of metronidazole, chloramphenicol, meropenem, imipenem and combinations of β-lactam antibiotics with sulbactam – with high activity and drugs of choice for treatment; 2nd group – clindamycin, cefoxitin, carbenicillin/and azlocillin, piperacillin/ – with a good activity and low percent of resistant strains; 3rd group – of tetracycline and erythromycin with higher percent of resistant strains including the new macrolides as josamycin, clarithromycin, roxithromycin and azithromycin; 4th group – penicillins/ampicillin, amoxicillin, penicillin/and cephalosporins/cefamandole, cefazolin, cefotaxime and cefoperazone/ – not suitable for treatment of infections including Bacteroides fragilis group strains, with a very high percent of resistant strains, probably due to β-lactamase activity in most of the strains.ConclusionA continued updating and a follow-up in the changes of antibiotic susceptibility are necessary in every country as resistance patterns vary not only between geographical regions but also even among medical centers and hospitals which may be connected with differences in antibiotic usage in man and animals.     

白背飞虱的迁飞生物学:安徽潜山个例分析

通过田间系统调查与雌虫卵巢系统解剖研究了2008—2010年潜山混作稻区白背飞虱Sogatella furcifera (Horváth)的种群动态以及各发生世代的虫源性质,并结合2005年以来的灯诱及田间普查资料分析了造成不同年份白背飞虱种群消长态势差异性的主要原因。结果表明:(1)第3、4代白背飞虱分别在8月初和9月上中旬有2个发生高峰期,其中第3代主害单季中稻,第4代主害双季晚稻。(2)单季中稻和双季晚稻田白背飞虱各发生世代的虫源性质有所不同,中稻田四(2)代后期、五(3)代前期属于本地滞留、部分迁出,五(3)代后期属于大部迁出、少量滞留为害;而晚稻田五(3)代后期为基本迁入型,六(4)代前期为本地繁殖、少量迁出型,六(4)代后期大部迁出。(3)前期迁入虫量会影响田间2、3代种群数量,中稻田第3代滞留虫量的多少是影响双晚田后期发生量的重要因素,而降雨、温度等气象因子则是影响主害代(第3代)种群迁出与滞留的关键因子。     

Comparative in vitro activity of cefepime and other antibiotics against clinical strains of gram-negative bacteria]

In vitro activity of cefepime against etiologically significant strains of gramnegative microflora of patients treated in the Reanimation and Intensive Care Unit after cardiosurgical operations was evaluated. Sixty four strains of gramnegative aerobic bacteria isolated within the period from October 2001 to April 2002 were tested. The isolates susceptibility was determined by the disk diffusion method. Cefepime had an obvious advantage over the 3rd generation cephalosporins. Low incidence of cefepime resistant strains of the problem organisms in the Reanimation and Intensive Care Unit should be taken into account in empirical therapy of infections due to such pathogens.     

Cefepime (maxipime) in the treatment of severe urinary tract infection]

Comparative susceptibility of microflora isolates from patients with complicated urinary tract infections to cefepime, other cephalosporins, amikacin, ciprofloxacin and ofloxacin was studied. Isolates in the diagnostic titers (5 x 10(4)-5 x 10(8)) from the patients treated with cefepime as etiotropic monotherapy were identified. The treatment course was 7 to 14 days. The daily dose was 1 to 2 g. The clinical and bacteriological efficacies of the cefepime therapy equaled to 93.2 and 85.4% respectively.