European Journal of Clinical Microbiology Infectious Diseases

Kontoyiannis, D.; Bodey, G.

doi: 10.1007/s10096-002-0699-zpmid: 11957017

Despite significant advances in the management of immunosuppressed patients, invasive aspergillosis remains an important life-threatening complication. In the past two decades, the incidence of invasive aspergillosis in this population has continued to increase. Factors that predispose patients to develop invasive aspergillosis include prolonged granulocytopenia, the development of graft-versus-host disease, immunosuppressive therapy, the use of adrenal corticosteroids, and the prolonged impairment of host defenses associated with diseases such as chronic granulomatous disease. Environmental factors also play a key part in the pathogenesis of this infection, and therefore, infection control measures play a critical role in reducing exposure of patients to Aspergillus. New exciting developments in the early diagnosis of invasive aspergillosis and the acceleration of antifungal drug discovery offer promise for the future.

Bernabeu-Wittel, M.; Naranjo, M.; Cisneros, J.; Cañas, E.; Gentil, M.; Algarra, G.; Pereira, P.; González-Roncero, F.; de Alarcón, A.; Pachón, J.

doi: 10.1007/s10096-001-0684-ypmid: 11957018

Petrosillo, N.; Pantosti, A.; Bordi, E.; Spanó, A.; Del Grosso, M.; Tallarida, B.; Ippolito, G.

doi: 10.1007/s10096-001-0689-6pmid: 11957019

The aim of this study was to determine the factors favouring Streptococcus pneumoniae nasopharyngeal colonization of healthy children attending daycare centres and to describe the circulation of penicillin-nonsusceptible strains using molecular techniques. A single nasopharyngeal swab was obtained from 610 children attending daycare centres in the southeast area of Rome. Streptococcus pneumoniae isolates were serotyped, and antibiotic susceptibility was assayed by the E test. The genetic determinants of erythromycin resistance were detected by a duplex polymerase chain reaction, and the penicillin-nonsusceptible isolates were typed by pulsed-field gel electrophoresis. The overall carriage rate of Streptococcus pneumoniae was 14.9%. Living with more than three persons in the same household was the only risk factor statistically associated with carriage. Sixteen of 85 (18.8%) strains were nonsusceptible to penicillin, and 44 (52%) were resistant to erythromycin. Of the erythromycin-resistant strains, the vast majority showed a high level of resistance and carried the erm(B) gene. The penicillin-nonsusceptible strains belonged to six different serotypes; molecular typing showed that in only one case (2 strains) was there a circulation of the same clone in the same daycare centre. In view of the high rate of resistant Streptococcus pneumoniae strains, risk factors for carriage of resistant strains were evaluated. Children who received macrolides in the previous month had a higher risk of being colonized by macrolide-resistant strains as well as by strains resistant to both penicillin and erythromycin. Limiting the use of antibiotics in children seems the most appropriate measure to control the spread of antibiotic-resistant strains.

Lahti, E.; Eklund, M.; Ruutu, P.; Siitonen, A.; Rantala, L.; Nuorti, P.; Honkanen-Buzalski, T.

doi: 10.1007/s10096-001-0682-0pmid: 11957020

A total of 80 human infections by Escherichia coli O157:H7 were documented in Finland in 1997 and 1998. Most were sporadic and their sources undetermined. Five cases not associated with one another, one of which led to secondary transmission within a family, could be traced to five different dairy farms. These five case patients (age range 2–17 years, median age 3 years) were hospitalised with bloody diarrhoea; two of them developed haemolytic uraemic syndrome. All nine human isolates obtained were sorbitol negative, carried the verocytotoxin 2 and eae genes, and produced verocytotoxin and enterohaemolysin. The phage and pulsed-field gel electrophoresis types of the human and bovine isolates from the corresponding farms were indistinguishable. The cattle (20–70 animals per farm) were monitored for up to 2 years after the human cases. The proportion of cattle excreting the type that caused the human infections varied from 3.2 to 66.7% when sampled soon after the human cases, and from 0.0 to 5.3% about a year or so later. On most of the farms, the animals excreted the pathogen intermittently. On one farm, Escherichia coli O157 isolates with other characteristics were also occasionally isolated. Although the infections were traced back to the farms, it could not be established whether the source was unpasteurised milk or direct or indirect contact with cattle. The results of this study emphasise the need for special recommendations for children visiting or living on a farm to prevent these infections.

Munson, E.; Pfaller, M.; Koontz, F.; Doern, G.

doi: 10.1007/s10096-001-0688-7pmid: 11957021

The accurate identification of Haemophilus spp. is essential for optimizing the role of the clinical microbiology laboratory in the diagnosis and management of Haemophilus infections. One laboratory-prepared medium and eight commercially available test systems were examined in parallel as a means of identifying 378 clinical isolates of Haemophilus spp. as either Haemophilus influenzae or non-Haemophilus influenzae spp. At least one discordant result was noted with 187 (49.5%) of the isolates tested. Discordant results were resolved either by majority rule for isolates with less than three discordant test results or by confirming the identity using conventional biochemical tests for isolates with three or more discordant test results (n=20). Among these 20 isolates, 2 were judged not to belong to the Haemophilus genus. Comparisons of three porphyrin-based methods, three growth factor-based methods (1 of which also incorporates a porphyrin testing component), and three biochemical-based methods revealed varying discrepancy rates within each testing method. In general, porphyrin-based methods, with overall discrepancy rates of 1.3% or less, outperformed other testing methods. One important exception was the performance of the porphyrin testing component of the Haemophilus Identification Test Kit (Remel, USA), which produced an overall discrepancy rate of 28.5% and a false-negative rate of 52.2% with non-Haemophilus influenzae isolates. Growth factor-based methods yielded overall discrepancy rates ranging from 1.6% (Haemophilus Identification Agar Quad; Remel) to 10.4% (hemin and nicotinamide adenine dinucleotide disk component of the Haemophilus Identification Test Kit). Biochemical-based assays produced overall discrepancy rates ranging from 4.5% (API NH; bioMérieux Vitek, USA) to 10.1% (Neisseria Haemophilus Identification Card; bioMérieux Vitek). Collectively, these results suggest that porphyrin-based testing methods represent the most reliable means for identifying Haemophilus spp.

Voogt, N.; Wannet, W.; Nagelkerke, N.; Henken, A.

doi: 10.1007/s10096-001-0685-xpmid: 11957022

The capacity of national reference laboratories of the European Union member states to correctly serotype Salmonella strains was assessed in four collaborative studies on serotyping in the period 1995–1999. Participants were asked to identify 20 strains in studies I, II and III and 16 strains in study IV, using the typing method routinely performed in their laboratory. In the first study, the strains to be identified belonged to Salmonella enterica subsp. enterica, salamae or houtenae, while in the other studies only strains belonging to Salmonella enterica subsp. enterica were included. Significant differences between laboratories and between studies were found. Differences were related to the frequency of actual occurrence of the study strains in the area served by the laboratory and the number of antisera available in the laboratory.

Nucci, M.; Colombo, A.

doi: 10.1007/s10096-002-0697-1pmid: 11957023

In order to assess the risk factors for breakthrough candidemia (candidemia occurring in patients receiving at least 3 days of systemic fluconazole or amphotericin B), 270 cases of candidemia occurring in two tertiary hospitals were analyzed. Using multivariate analysis, profound neutropenia (<100/mm3) (odds ratio [OR], 9.14), use of corticosteroids (OR, 3.17), and heavy antibiotic exposure (previous use of 2 or more antibiotics for at least 14 days) (OR, 2.93) were identified as risk factors. Neither the susceptibility of the isolates nor the presence of a catheter was found to be a risk factor. These data suggest that gastrointestinal colonization plays a major role in the development of breakthrough candidemia.

Jiménez-Mejías, M.; Pichardo-Guerrero, C.; Márquez-Rivas, F.; Martín-Lozano, D.; Prados, T.; Pachón, J.

doi: 10.1007/s10096-001-0680-2pmid: 11957024

Described here is a case of meningitis caused by multidrug-resistant Acinetobacter baumannii susceptible only to colistin, which was treated successfully with intravenous colistin sulfomethate sodium (5 mg/kg/day). The levels of colistin in serum and cerebrospinal fluid and the pharmacokinetic/pharmacodynamic parameters of colistin were determined. In this case, intravenously administered colistin penetrated cerebrospinal fluid (25% of serum levels) at levels sustaining bactericidal concentrations.

Myjak, P.; Nahorski, W.; Pieniazek, N.; Pietkiewicz, H.

doi: 10.1007/s10096-001-0690-0pmid: 11957025

The aim of the present study was to use the polymerase chain reaction (PCR) to detect and identify Plasmodium spp. in diagnostic specimens, especially in those from patients diagnosed by microscopy as having possible mixed infections, and in those demonstrating low parasitemia or those that were parasite-negative. For most of the specimens, the PCR results were in accordance with microscopic findings, and in 16.2% of the cases with low parasitemia PCR enhanced the results by identifying the parasite species. This method detected one additional case of Plasmodium falciparum malaria among the patients with fever of unknown origin. The sensitivity of PCR for detecting Plasmodium DNA was found to correspond to 1.35–0.38 and 0.12 for Plasmodium falciparum and Plasmodium vivax parasites per microliter of blood, respectively. Follow-up examinations demonstrated that most of the patients became negative for Plasmodium DNA from 1 to 4 days after the disappearance of parasitemia, as determined by examination of blood films. In conclusion, PCR performed by the reference laboratory significantly enhanced the microscopic diagnosis of malaria and proved very helpful in cases of low parasitemia and in cases of mixed infection.

Roca, C.; Balanzó, X.; Gascón, J.; Fernández-Roure, J.; Vinuesa, T.; Valls, M.; Sauca, G.; Corachán, M.

doi: 10.1007/s10096-001-0683-zpmid: 11957026

The study presented here aimed to contrast the marked clinical differences in the presentation of Schistosoma mansoni-induced infection between immigrants and travellers entering Spain from endemic regions, and to elucidate the therapeutic implications of these infections. A total of 200 African immigrants and 80 travellers with schistosomiasis were included in the study. Among the immigrants, 25 patients were diagnosed with Schistosoma mansoni infection; 15 presented with nonspecific symptoms, and 10 were asymptomatic. Hepatosplenomegaly was observed in nine. Among the travellers, 14 were diagnosed with Schistosoma mansoni infection; four were asymptomatic, four had Katayama syndrome, four had diarrhoea, and two had prostatitis. All of the patients were treated with praziquantel. Patients diagnosed with Katayama syndrome received praziquantel and dexamethasone for 3 days, with the praziquantel treatment being repeated at 3–4 weeks. The significant differences observed in the clinical presentation of Schistosoma mansoni-induced infection, indicate that a well-differentiated therapeutic strategy is required when this infection is diagnosed in a non-immune (traveller) or a semi-immune (immigrant) patient.