European Journal of Clinical Microbiology Infectious Diseases

Singh,

doi: 10.1007/s10096-002-0801-6pmid: 12373496

Schmitz, ; Higgins, ; Mayer, ; Fluit, ; Dalhoff,

doi: 10.1007/s10096-002-0788-zpmid: 12373497

The quinolones are a potent class of antimicrobial agents that target two essential enzymes of bacterial cells: DNA gyrase and topoisomerase IV. Resistance is mediated chiefly through stepwise mutations in the genes that encode these enzymes, leading to alterations of the target site. These mutations occur in an area called the "quinolone resistance determining region". In gram-positive organisms, mutations occur more often in topoisomerase IV than in DNA gyrase. This target preference appears to depend upon two factors: the species of organism and the selecting drug. Resistance can be enhanced by a decrease in intracellular drug concentration, which is mediated through efflux pumps. The newer generation of fluoroquinolones and non-fluorinated quinolones exhibits enhanced activity against gram-positive organisms compared to the older members of this drug class, although development of resistance to these drugs has been demonstrated in vitro. This review gives a chronological perspective of the literature on the action of DNA gyrase and topoisomerase IV and the mechanisms of resistance to quinolones in staphylococci, streptococci and enterococci.

Boisson, ; Thouverez, ; Talon, ; Bertrand,

doi: 10.1007/s10096-002-0799-9pmid: 12373498

The purpose of this study was to determine incidence of coagulase-negative staphylococci (CNS) bacteraemia and to characterise the epidemiology of isolates with reduced susceptibility to glycopeptides. CNS isolates from bloodstream infections were collected and characterised by determination of the species, analysis of antibiotic susceptibility, and restriction fragment length polymorphism using pulsed-field gel electrophoresis. The medical records of patients with positive cultures and the trends in glycopeptide use were reviewed to determine the effect of previous antibiotic treatment on the susceptibility profile of these organisms. The incidence of bacteraemia caused by CNS was 0.26 per 100 patients or 0.36 per 1,000 days of hospitalisation. According to genomic fingerprinting typing, 41 (67.2%) cases of bacteraemia were caused by a unique strain of CNS and 20 were caused by several strains. Nineteen of the 61 cases of bacteraemia studied were caused by an isolate with decreased susceptibility to teicoplanin. Genomic DNA analysis of the 90 CNS isolates recovered from the 61 cases of bacteraemia generated 50 unique profiles (1 isolate per major PFGE pattern) and 13 multiple profiles (several isolates per major PFGE pattern). Neither decreased susceptibility of an isolate to teicoplanin nor hospital acquisition was associated with a multiple profile. There was a significant correlation between the incidence of bacteraemia caused by CNS with decreased susceptibility to teicoplanin and glycopeptide use at the unit level but not in individual patients. Cross-transmission did not play an important role in the dissemination of CNS with decreased susceptibility to teicoplanin, thus strains probably become resistant as a result of antibiotic pressure. Prudent use of glycopeptides is necessary to minimise the spread of resistance to these agents.

Gray,

doi: 10.1007/s10096-002-0796-zpmid: 12373499

This report describes the development and evaluation of a selective egg-based medium for ambient-temperature storage and transport of nasopharyngeal (NP) swabs in colonization studies of Streptococcus pneumoniae. Egg-thioglycolate-antibiotic (ETA) medium is based on Dorset's egg medium but made with thioglycolate broth and the addition of gentamicin (3 mg/l), nalidixic acid (15 mg/l), and amphotericin B (2.5 mg/l). Laboratory studies were conducted using mock swabs from 34 NP samples with known colony counts of pneumococci, which had previously been frozen in STGG (skim milk, tryptone, glucose, glycerol) broth. ETA facilitated better recovery of pneumococci than did either Stuart's or Amies' transport media. In a field study of 117 children, NP swabs were placed in ETA, after being vortexed in STGG and direct-plated for colony counts. Of 52 swabs that were culture positive for pneumococci, all 52 grew pneumococci after 4 days of storage in ETA, and 49 isolates were recovered after 7 days. Transport media such as Stuart's and Amies' require the processing of swabs within about 24 h, and storage in STGG broth requires freezing at –70°C. ETA should be a useful addition to the storage media available for use in epidemiological studies of pneumococcal colonization, especially in situations where prompt processing, rapid transport, or low-temperature storage are not possible.

Le Moal, ; Roblot, ; Paccalin, ; Sosner, ; Burucoa, ; Roblot, ; Becq-Giraudon,

doi: 10.1007/s10096-002-0798-xpmid: 12373500

Spondylodiscitis is rarely observed in association with infective endocarditis (IE). In the study presented here, 92 cases of definite IE were examined. Spondylodiscitis was present in 14 (15%) cases. The mean age of patients with spondylodiscitis was 69.1±13.6 years (range, 33–87 years). The male-to-female ratio was 8:6. Predisposing heart disease was found in nine (64.3%) cases. Back pain was reported in all cases. Spondylodiscitis was diagnosed before endocarditis in all cases. The infection affected the lumbar spine in 10 (71%) cases. A bacterium was isolated in all cases: group D Streptococcus (n=5; 35.7%), coagulase-negative Staphylococcus (n=4; 28.6%), and others (n=5). Endocarditis affected predominantly the aortic valve (43%). The outcome was favourable in 12 cases. No differences in clinical features, evolution of disease, or laboratory values were found between IE patients with and IE patients without spondylodiscitis. Spondylodiscitis does not appear to worsen prognosis of IE, although the need for cardiac valve replacement seems to be more frequent in IE patients with spondylodiscitis. IE should be included in the differential diagnosis in patients with infectious spondylodiscitis and risk factors for endocarditis. In such patients, echocardiography should be performed routinely.

Berghmans, ; Crokaert, ; Sculier,

doi: 10.1007/s10096-002-0794-1pmid: 12373501

Vibrio cholerae was isolated from the blood cultures of a neutropenic patient treated with chemotherapy for non-small-cell lung cancer. Attempts to isolate Vibrio spp. from a rectal swab and stool were unsuccessful. Piperacillin/tazobactam treatment resulted in eradication of the microorganism from the patient's blood. Although Vibrio spp. have occasionally been the source of infection in immunocompromised patients, this report describes the first case of non-0:1 Vibrio cholerae bacteremia in a neutropenic patient with a solid tumour.

Filisetti, ; Bombard, ; N'Guiri, ; Dahan, ; Molet, ; Abou-Bacar, ; Hansmann, ; Christmann, ; Candolfi,

doi: 10.1007/s10096-002-0800-7pmid: 12373502

The diagnostic value of a polymerase chain reaction (PCR)-based method for amplifying a new target of repeated genes (STEVOR) in Plasmodium falciparum was prospectively assessed on samples from 210 febrile patients returning from areas endemic for malaria. This method is capable of detecting 0.01 parasites in one microliter of blood. Plasmodium falciparum STEVOR PCR confirmed the results of the thin- and thick-film direct examination method but identified Plasmodium falciparum in four patients in whom direct examination was inconclusive at the species level. Moreover, PCR was positive in two patients with a negative direct examination. Thus, Plasmodium falciparum STEVOR PCR had 100% sensitivity and specificity and could be used in selected parasitology laboratories when expert advice is required.

Brandonisio, ; Fumarola, ; Spinelli, ; Gradoni,

doi: 10.1007/s10096-002-0797-ypmid: 12373503

An unusual presentation of leishmaniasis that occurred in an Italian immunocompetent woman is described. The patient had a long history of coagulopathy due to factor VIII deficiency and pain in the right lumbar region. Computed axial tomography demonstrated a cystic mass in the right adrenal gland. Histological examination of the surgically removed cyst showed the presence of histiocytes containing Leishmania amastigotes. Serodiagnosis for leishmaniasis performed through immunofluorescent antibody testing and the rK39 enzyme immunoassay was positive, whereas a bone marrow aspirate did not reveal any parasite. The patient was not treated for leishmaniasis and recovered well after surgery. Serological testing was still positive 2 years after surgery, but clinical follow-up did not reveal the signs typical of visceral leishmaniasis.

Nuesch, ; Geigy, ; Schaedler, ; Battegay,

doi: 10.1007/s10096-002-0792-3pmid: 12373504

In order to determine the impact that highly active antiretroviral therapy (HAART) has on inpatients with HIV infection, HIV-infected patients hospitalized from 1994 to1999 at the Department of Internal Medicine, University of Basel, Switzerland, were investigated. During the observation period, 578 HIV-related hospitalizations occurred, and 502 charts from 262 different patients were available for evaluation. Analyses showed significant reductions in hospital mortality (from 13.2% to 6.5%) and length of stay for HIV-related admissions (from 16 to 11 days) in the post-HAART period, and the percentage of AIDS-related admissions decreased from 54.5% to 47.6%. However, the admission of HIV-infected patients to the intensive care unit increased from 6.3% to 11.8%, which could indicate that treating physicians have greater confidence in the outcome of HIV-infected patients due to better therapeutic options. Since the advent of HAART, the yearly number of admissions related to HIV dropped by 49% and HAART was administered often during hospital stay. By the end of the study period, death due to multiple HIV-associated diseases and wasting had disappeared.

Kvale, ; Aaberge, ; Frøland,

doi: 10.1007/s10096-002-0803-4pmid: 12373505

In the study presented here immunologic markers and HIV RNA were related to specific antibody responses in 50 HIV-infected patients who had moderate immunodeficiency (median CD4+, 295) and were vaccinated with a pneumococcal polysaccharide vaccine. Low responses were associated with low IgG2 or high IgM levels (P=0.01) and good responses with high IgG4 (P=0.05) or IgG2 (P=0.07) or low β2 microglobulin (P=0.04) levels. A combination of IgG2 levels >1.0 g/l and IgM <1.6 g/l at baseline significantly predicted a twofold or better response in logistic regression analysis (P=0.025). Neither CD4+ lymphocyte counts nor HIV RNA levels were predictive, but it should be noted that good antibody responses were not restricted to patients with high CD4+ cell counts or low HIV RNA levels.