Change in the composition of Candida albicans cells during development of resistance to polyene antibiotics

The composition of lipid and protein components of the membrane structures was studied in the strains of Candida albicans susceptible and resistant to polyene antibiotics. The content of sterols was lower and the content of free fatty acids was higher in the cells of resistant strains cf. susceptible strains. The composition of sterols was also different in the resistant strains: analysis of absorption spectra of sterol extracts in heptane in UV revealed complete absence of ergosterol, the main component of the susceptible strain, and appearance of a heterogenous peak at 215--240 nm.     

Hypertension, diuretics, and antihypertensive medications as possible risk factors for renal cell cancer

We identified the serotypes and genomes patterns of 100 strains of Pseudomonas aeruginosa (P. aeruginosa) that had been isolated from patients who were admitted to the hospital of the Fukui Medical School between 1992 and 1995. A monoclonal diagnostic kit was used to identify the serotypes. Genome patterns were determined by pulsed field gel electrophoresis (PFGE). Serotypes A, B, C, D, E, F, G and I exhibited distinct genome patterns. Differences in genome patterns were also observed in strains of serotypes E and G, depending on the types of clinical samples collected and/or the area of the hospital from which they were isolated. Many of the multiple antibiotic-resistant strains of P. aeruginosa exhibited serotype E. The genome pattern differed between strains that were susceptible vs. resistant to multiple antibiotics. The latter strains exhibited similar genome patterns regardless of their origin. These findings suggest that analysis of genome patterns is important for identifying the origin of nosocomial infection caused by P. aeruginosa, serotype E.     

Drug resistance in tuberculosis

Drug-resistant tuberculosis remains a worldwide problem. New laboratory methods have improved our ability to more rapidly identify resistant strains, but the most effective approach is to prevent the appearance of resistance by appropriate choice of antibiotics and directly-observed therapy. Mycobacterium tuberculosis is treated with familiar and unique drugs; consequently, mechanisms of resistance have some unique features. All drug resistance thus far identified develops by mutational events rather than acquisition of resistance genes from other bacteria. An agenda is presented for countering the appearance of further drug resistance in mycobacteria.     

Infections caused by multiresistant enterococci in Norway

During the last decade antimicrobial resistant pathogens have become a major medical problem. Internationally, multiresistant enterococci have increased nosocomial morbidity and mortality. Such strains are often resistant to ampicillin, aminoglycosides, and glycopeptides such as vancomycin. The spread of these strains has been shown to correlate to the use of antibiotics and the practice of suboptimal infection control within health care facilities. The current situation in Norwegian hospitals is presented, including the only six cases with infections and the three carriers of vancomycin resistant enterococci found to date. Surveillance in the hospitals shows that such strains are uncommon in non-infected patients. To maintain this favourable situation it is necessary to continue to practice effective methods of infection control and to employ sound antibiotic policies.     

Study of the antibiotic sensitivity of Shigella newcastle isolated in Zaporozhe Province

Sensitivity to antibacterial drugs of 510 strains of Shigella Newcastle isolated from both sporadic patients and cases during the disease outbreaks was studied. The studies revealed a rather high percentage of Shigella Newcastle resistant to the antibiotics widely used in clinical practice. Most of the strains, i.e. 90.5 per cent were resistant to tetracycline and a significant number of the isolates, i.e. 55.6--53.3 per cent were resistant to streptomycin and erythromycin. A statistically reliable predominance of the Shigella resistant to levomycetin and streptomycin in the disease foci was noted as compared to the Shigella isolated from the sporadic patients. Most of the isolates were simultaneously resistant to several antibiotics. Thus, resistance to 2,3--4 and 5--6 antibiotics was found in 28, 54.3 and I.I per cent of the cultures respectively. At the same time almost all Shigella Newcastle strains were sensitive to rifampicin, neomycin and monomycin (aminoglycoside antibiotics), enteroseptol (oxychinoline drug) and furazolidone (nitrofuran drug).     

Peripheral nerve regeneration: the effects of postoperative irradiation

Our purpose is to review recent data and provide a clinical opinion on the use of antibiotics to prevent preterm birth or related maternal-neonatal complications. A literature review and a synthesis of opinion are provided. During prenatal care, standard practices should be applied regarding Neisseria gonorrhoeae, Chlamydia trachomatis, and bacteriuria. In addition, screen for and treat bacterial vaginosis in patients at high risk for preterm birth but do not treat Ureaplasma urealyticum or group B streptococci genital colonization. With preterm labor and intact membranes, standard practices should be applied regarding group B streptococci prophylaxis. Do not give antibiotics routinely to prolong pregnancy, but in patients with bacterial vaginosis and Trichomonas vaginalis specific treatment should be given. With preterm premature rupture of membranes, standard practices should be applied regarding group B streptococci prophylaxis, but additional antibiotics should also be given to prolong pregnancies at 24 to 32 weeks' gestation. Reported adverse effects have been few to date. However, increased diligence is needed for resistant organisms. In selected clinical settings antibiotic therapy is now indicated to prolong pregnancy and prevent maternal-neonatal complications associated with preterm birth.     

Pneumococcal vaccine]

Streptococcus pneumoniae is a common cause of morbidity and mortality in children, immunodeficient individuals and elderly people. As antibiotic resistant strains become more prevalent, pneumococcal infections will become more difficult to manage. Pneumococcal vaccination is inexpensive, and serious side effects are rare. However, the efficacy and safety of the vaccine have been questioned, and the use of vaccination is limited. This article discusses factors to be considered when assessing the indications for pneumococcal vaccination. Immunisation together with a strict policy on the use of antibiotics are our most efficient means for preventing pneumococcal disease and spread of antibiotic resistant strains. Norwegian physicians are encouraged to use pneumococcal vaccine according to the present indications.     

Imipenem resistance in Pseudomonas aeruginosa

In 1997 in western Austria, 9.9% of Pseudomonas aeruginosa strains from patients of general practitioners were resistant to imipenem as well as 18.2% of the isolates from hospitals and 20.2% of the strains at a university teaching hospital. Within the hospital the imipenem resistance varied from 9.9% among out-patients to 28.7% in isolates from intensive care units. In medical/surgical words, up to 15.1% of P. aeruginosa strains were resistant to imipenem. The incidence of imipenem-resistant P. aeruginosa strains correlates to the use of carbapenems. In June 1997, 10 consecutive isolates from 8 patients were obtained and typed using restriction fragment length polymorphism analysis (RFLP) and Pyocin typing. All 10 isolates were resistant to meropenem as well as to imipenem. The finding (by RFLP and Pyocin typing) of individual bacterial types in each isolate strongly contradicts the spread of infection by cross infection. However, all patients were proven to have been treated with imipenem during the 3 months prior to testing. In 1997, 13,880 g of imipenem were used at the university hospital in Innsbruck. The use of carbapenems appears to be the main cause for the increased incidence of imipenem-resistant P. aeruginosa strains.     

New gram-positive opportunistic bacteria: pathogenic role and treatment

NOVEL BACTERIA: The appearance of novel bacterial species among Gram positive microorganisms is mainly related to progress in bacterial taxonomy justifying such nomen species, i.e. C. jeikeium, C. urealyticum or R. equi. Another feature of such emergence of "Novel" bacteria is related to the rise in the number of clinical observations mediated by some well-known species described elsewhere such as in food bacteriology. PREDISPOSING FACTORS: Among Gram positive microorganisms, emergence for some species and renaissance or rebirth for others is mainly explained by natural resistance to widely used antibiotics including beta-lactams such as third generation cephalosporins, aminoglycosides, or more recently glycopeptides and the combined effect of several predisposing factors (hospitalized patients, underlying disease or prematurity, interruption of the normal integumentary defense via intravascular catheters). Clinical features depend on the bacterial species. Bacteriological diagnosis is easily obtained in terms of isolation and identification. Nevertheless, as for any opportunistic pathogen, a distinction must be made between colonization and infection. Finally successful treatment regimens depend on the bacterial species and may include surgery.     

Transcontinental importation into the UK of Escherichia coli expressing a plasmid-mediated AmpC-type beta-lactamase exposed during an outbreak of SHV-5 extended-spectrum beta-lactamase in a Leeds hospital

Sixteen strains of Escherichia coli with high-level resistance to extended-spectrum cephalosporins and other classes of antibiotic have been isolated at St James' University Hospital, Leeds. They produce up to three separate beta-lactamases: TEM-1, SHV-5 and, in five isolates, a plasmid-mediated AmpC-type enzyme. With the exception of carbapenems, the isolates reported in this study were resistant to all beta-lactam antibiotics including extended-spectrum cephalosporins and the monobactam aztreonam. There was evidence of the spread of a plasmid encoding SHV-5, particularly amongst patients on the liver transplant unit. Sensitivity to beta-lactam antibiotics in five isolates expressing the AmpC-type beta-lactamase was not restored by the beta-lactamase inhibitor clavulanic acid. These bacteria also carried blaSHV-5 on a large plasmid. PCR-amplification of the structural gene and digestion with restriction endonucleases demonstrated that the plasmid-mediated blaAmpC probably identified as BIL-1 using the criteria available. Four of the five patients carrying isolates that carried the plasmid-located blaAmpC gene had recently visited the Indian subcontinent and we presume that they returned carrying these bacteria. Restriction fragment length polymorphism analysis using pulsed field gel electrophoresis (PFGE) suggests that at least four distinct strains existed amongst these five isolates. The two isolates that had very similar PFGE patterns had different plasmid profiles and were isolated from different locations in the hospital and at different times. This study demonstrates the ease with which highly resistant bacteria can be imported into the UK and spread within hospitals.     

Efficient expression of pro-urokinase by human lymphoblastoid Namalwa KJM-1 cells using moloney retroviral promoter

The activity of antimicrobial agents against clinical isolates of Nocardia was studied by determination of the Minimal Inhibitory Concentrations (MICs) and Disk Diffusion Technique, according to the National Committee for the clinical Laboratory Standards (NCCLS). The object was: (a) to determine the 'in vitro' susceptibility of the strains that cause human mycetomas; (b) to determine the presence of different patterns of sensitivity among the regional strains; (c) to evaluate the Disk Diffusion Technique using disks commercially available with the antimicrobial concentrations normally used in the microbiological practice. Comparing the MIC values obtained with the values suggested by the National Committee for Clinical Laboratory Standards for Nocardia spp. (broth microdilution MIC breakpoints), we found that local strains are susceptible to amikacin, cefotaxime, ceftriaxone and TMP-SMZ; moderately susceptible to ampicillin and resistant to ciprofloxacin and erythromycin. The results obtained by both methods showed the presence of different patterns of sensitivity among the regional strains of N. brasiliensis. This showed strains sensitive and resistant to antibiotics. The Disk Diffusion Technique, even if it is not the adequate method to study the sensitivity patterns of different strains against antimicrobial agents, permits the differentiation between strains sensitive and resistant to antibiotics.     

Chlamydia trachomatis infection in asymptomatic Chilean men and with urethritis. Usefulness of first catch urine samples

Many new antibiotics with improved pharmacodynamic and pharmacokinetic properties have been developed in the last 30 years. This development, however, went down in the last five years. With modern techniques of sequencing of the complete bacterial genum in order to find new targest, with combinatory chemistry and with the high throughput screening about one new drug per year can be developed in the future. The activity of antibiotics is diminished by the increasing number of resistant strains and by the increase of infections with naturally resistant microorganisms. The rational use of antibiotics can slow down this trend and perhaps reverse it. To reach this aim it is necessary to increase research activities in the field of pharmacodynamics in order to allow a more rational dosing. Better technology documentation and statistics in microbiological diagnostics could improve calculated chemotherapy. Furthermore we need more information about the epidemiology of resistant bacteria, at least the knowledge about receptors, mechanism of action and mechanism of resistance should be known to circumvent these obstacles in antimicrobial chemotherapy.     

Variation in the susceptibility of strains of Staphylococcus aureus to oxacillin, cephalothin, and gentamicin

Three cases of staphylococcal bacteremia caused by organisms that were inhibited by low concentrations of oxacillin, but were resistant to the killing effects of oxacillin, stimulated us to screen 60 clinical isolates of Staphylococcus aureus for their susceptibility to oxacillin, cephalothin, and gentamicin. All 60 strains were inhibited by low concentrations of the antibiotics. The antibiotics were bactericidal against 27 of the 60 strains and only bacteriostatic against the other 33 after 24 h of incubation. However, after 48 h of incubation, the antibiotics were also bactericidal against the latter group.     

Pneumococcal infections in the adult population observed at the Poitiers University Hospital. Epidemiologic and clinical study

OBJECTIVES: The aim of this study was to assess the prevalence of penicillin-nonsusceptible pneumococcus (PNSP) infections and their clinical and microbiological features among an adult population hospitalized at the Poitiers University Hospital. PATIENTS AND METHODS: A prospective study was conducted between November 1994 and October 1995 and included all pneumococcus infections. RESULTS: Fifty-three adults with one pneumococcal strain were included. The overall rate of PNSP strains was 28%. Infections with PNSP strains were more resistant than penicillin-susceptible pneumococcus to other antibiotics. The most frequent infection was pneumonia (36 infections, 28% PNSP). DISCUSSION: The rate of PNSP in pneumococcal infections was the same in the Poitiers University Hospital as in national surveys in France. The high percentage of multiresistant strains (86.5%) limit the use of antibiotics other than beta-lactams. Surveys of pneumococcal resistance to antibiotics are needed to adapt antibiotic strategies to the local epidemiological situation.     

Topographic variation in biglycan and decorin synthesis by articular cartilage in the early stages of osteoarthritis: an experimental study in sheep

From October 1988 to January 1992, nine isolates of Pseudomonas aeruginosa carrying transferable plasmids encoding imipenem-hydrolyzing beta-lactamase (pI = c. 9.5) were recovered from nine different patients in a neurosurgical ward of a hospital in Japan. The beta-lactamase activities of the sonicated extracts from the transconjugants were inhibited by EDTA and this was partially reversible by the addition of zinc cation. The substrate specificity and pI of the beta-lactamase were similar to those of the metallo beta-lactamases from P. aeruginosa and Serratia marcescens TN9106. All strains were resistant to imipenem, carbenicillin and antipseudomonal cephems including ceftazidime, cefsulodin, cefpirome, while four and five strains were susceptible to piperacillin and aztreonam, respectively. Both low level imipenem resistance and high level cephem resistance were co-transferred with the production of metallo beta-lactamase, while resistance to piperacillin, aztreonam, and high level imipenem-resistance were not selected. Production of chromosomal cephalosporinase in piperacillin resistant strains was derepressed, and production of outer membrane protein of D2 was diminished in highly imipenem resistant strains. Six strains were isolated in 1991, and the amounts of antipseudomonal agents, especially imipenem, used in the neurosurgical ward increased markedly in this year. Only three of the nine isolates had the same serotype, pyocin type and phage type. Our results suggest that the repeated isolation of imipenem and cephem-resistant P. aeruginosa producing metallo beta-lactamase was related to the high usage of antipseudomonal beta-lactam antibiotics such as imipenem, and was exacerbated by the dissemination of a plasmid.     

Evidence of enhanced kindling and hippocampal neuronal injury in immature rats with neuronal migration disorders

To clarify the characteristic features of nosocomial pneumonia in a community hospital, we performed a clinical analysis of 147 patients (155 episodes) with nosocomial pneumonia. The following results were obtained. 1, Regarding the risk factors for nosocomial pneumonia, factors such as the patient whose age was over 65 years, a duration of admission of over one month, performance status 4 and underlying respiratory diseases associated with the appearance of nosocomial pneumonia. 2, The causative microorganism isolated from the sputum of the patient with nosocomial pneumonia was frequently a multi-drug resistant microorganism such as Methicillin-resistant Staphylococcus aureus (MRSA). 3, regarding treatment, although several antibiotics were administered for a long time, mechanical ventilation was used on 31% of the patients, and steroid pulse therapy was carried out on 24%. The clinical efficacy was poor with a 50% mortality rate. The reason why treatment of nosocomial pneumonia was difficult is thought to be been related to the general condition of these inpatients and to the appearance of a multi-drug resistant, polymicrobial microorganisms.     

In-vitro activity of psychiatric drugs against Corynebacterium urealyticum (Corynebacterium group D2)

We tested the in-vitro activity of amoxycillin, amoxycillin/clavulanic acid, cefotaxime, gentamicin, trimethoprim-sulphamethoxazole, tetracycline, norfloxacin, ciprofloxacin, vancomycin, teicoplanin, clindamycin and five psychiatric drugs (chlorpromazine, sertraline, fluoxetine, paroxetine and risperidone) against 32 strains of Corynebacterium urealyticum. Resistance rates exceeded 90% for all antibiotics except glycopeptides, quinolones and tetracycline. Sertraline was the most active psychiatric drug. We tested the influence of sertraline on the activity of amoxycillin, amoxycillin/clavulanic acid, cefotaxime, gentamicin, trimethoprim-sulphamethoxazole, tetracycline and ciprofloxacin. We did not observe antagonism in any case. Sertraline enhanced the activity of ciprofloxacin and tetracycline against all strains (MIC decrease: 4-64-fold for ciprofloxacin, 2-32-fold for tetracycline).     

New approaches in vaccine development

BACKGROUND: A prospective study was carried out at the University Hospital, Kuala Lumpur to determine the cervical carriage rate of Ureaplasma urealyticum and Mycoplasma hominis among healthy pregnant women at delivery and the incidence of nasopharyngeal colonisation among their infants. PATIENTS: Sixty mother and baby pairs were examined. RESULTS: Cervical colonisation among the mothers was found to be 56.7% for U.urealyticum and 17.7% for M.hominis. The transmission rate to their infants was 88.2% and 30% for U.urealyticum and M.hominis respectively. CONCLUSION: There was no statistically significant difference in the maternal colonisation rates according to ethnic group, parity and past history of abortion. All U.urealyticum isolates in our study were sensitive to erythromycin but about one-third were resistant to tetracycline and ciprofloxacin and 26.5% were resistant to minocycline.     

In vitro and in vivo studies on the role of dimethylsulfoxide (DMSO) in resensibilization of bacterial strains resistant to antibiotics and chemotherapeutic agents

Resensibilization in vitro to seven antibiotics under the influence of DMSO was studied in 624 resistant strains of five species of bacteria (E. coli, S. typhi, S. pyogenes, S. viridans, S. aureus), 61 strains of tubercle bacilli resistant to isonicotinic acid hydrazide (INH) and 19 strains of tubercle bacilli resistant to rifampicin (RMP). DMSO in concentrations of 0.1-10.0% caused reversion of sensitivity in strains of E. coli, S. pyogenes and S. viridans. Reversion in vivo of sensitivity to INH of tubercle bacilli was studied in experimental tuberculosis of guinea pigs. Tubercle bacilli previously resistant to INH recovered complete sensitivity to the drug, enabling animals infected with the INH-resistant strain of bacilli to be treated with INH.     

Resistance to antibiotics of Streptococcus pneumoniae strains

Streptococcus pneumoniae strains are exhibiting increasing rates of antibiotics resistance. A rapid increase of resistance was seen not only to penicillin but also other antimicrobial agents and therefore this paper describes the study of resistance and multiresistance of pneumococci to 7 antibiotics: penicillin (P), erythromycin (E), clindamycin (CC), tetracycline (T), co-trimoxazole (SXT), cefotaxime (CTX) and vancomycin (Va), using the disk-diffusion technique according to NCCLS procedure. We tested a total of 218 S. pneumoniae strains isolated from various materials: from sputum (54), noses (117), throats (28) and different swabs specimens (19). The overall percentage of resistant isolates to penicillin was 3.7%, to erythromycin--4.1%, to clindamycin--10.6%, to tetracycline--17.4%, to co-trimoxazole--15.6%, to cefotaxime--2.3%. In the sputum was most the monoresistant strains (66.7%). The multiresistance was highest in the penicillin resistant pneumococci. With the exception of vancomycin, the number of resistant strains to non-beta-lactam antibiotics (erythromycin, clindamycin, tetracycline, co-trimoxazole) was higher in penicillin-resistant strains compared with penicillin susceptible isolates. All isolates were susceptible to vancomycin.