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Biomedical subjects

I Wilhelmi

Publications and source records attributed to I Wilhelmi.

At least 19 recordsLinked to original sources

First detection of group C rotavirus in children with acute diarrhea in Spain.

Group C rotavirus causes sporadic cases and outbreaks of acute diarrhea in children and adults in many countries, but has never been detected among children in Spain. In a recently conducted surveillance study to screen fecal specimens for bacteria and viruses from a cohort of 822 young children who were treated for acute diarrhea in Madrid, no pathogens were detected in fecal specimens from 238 (29%) children. In this study, we examined 147 of those specimens for group C rotavirus by EIA and PCR and found 22 (15%) were positive. Our findings demonstrate that group C rotavirus is an important cause of childhood diarrhea in Spain.

Child↗

Viruses causing gastroenteritis.

Acute gastroenteritis is one of the most common diseases in humans worldwide. Viruses are recognized as important causes of this disease, particularly in children. Since the Norwalk virus was identified as a cause of gastroenteritis, the number of viral agents associated with diarrheal disease in humans has steadily increased. Rotavirus is the most common cause of severe diarrhea in children under 5 years of age. Astrovirus, calicivirus and enteric adenovirus are also important etiologic agents of acute gastroenteritis. Other viruses, such as toroviruses, coronaviruses, picobirnaviruses and pestiviruses, are increasingly being identified as causative agents of diarrhea. In recent years, the availability of diagnostic tests, mainly immunoassays or molecular biology techniques, has increased our understanding of this group of viruses. The future development of a safe and highly effective vaccine against rotavirus could prevent, at least, cases of severe diarrhea and reduce mortality from this disease.

Acute Disease↗

Molecular detection of human calicivirus among Spanish children with acute gastroenteritis.

A survey was conducted among Spanish children with gastroenteritis treated in an emergency room. Reverse transcription-PCR with specimens negative for other enteric pathogens was used. The minimum incidence of human calicivirus infection was 7.7%, with Lordsdale as the predominant genotype. The clinical features and severity of calicivirus and rotavirus were similar.

Acute Disease↗

New immunochromatographic method for rapid detection of rotaviruses in stool samples compared with standard enzyme immunoassay and latex agglutination techniques.

Three different commercial immunologic tests for rapid detection of group A rotavirus (an immunochromatographic method, latex agglutination, and enzyme immunoassay) were used to evaluate 228 faecal specimens obtained from Spanish children with acute gastroenteritis. After resolution of 30 (13.2%) discordant results by reverse transcription-polymerase chain reaction for rotavirus, the statistical values of the enzyme immunoassay, latex agglutination, and immunochromatographic method were respectively 96%, 68%, and 99% for sensitivity; 99%, 99%, and 96% for specificity; 98%, 96%, and 92% for positive predictive value; and 98%, 88%, and 99% for negative predictive value. The immunochromatographic technique showed high sensitivity and specificity and was rapid and easy to perform in the routine clinical laboratory.

Child, Preschool↗

[The molecular epidemiology of the rotavirus in Spanish children. The Rotavirus Study Group (GER)].

BACKGROUND: Rotavirus are the most common etiologic agent of acute gastroenteritis in childhood. The knowledge of the circulating antigenic types is important in development of future vacunes. METHODS: Faeces from children (age < 4 years) with acute gastroenteritis admitted in the two hospitals (Hospital Severo Ochoa-Madrid and Hospital General Vic-Barcelona) have been studied prospectively during one year (October-1996 to October-1997). The detection of rotavirus was performed by ELISA (IDEIA, Dako). All samples were G-serotyping by EIA-Mabs (Silenius Laboratories) and the indeterminate or non-serotypable samples were G-genotyping by RT-PCR. P genotypes were identified by RT-PCR. RESULTS: 322 (45%) patients with acute diarrhoea causing for rotavirus were confirmed, 242 coming from the Madrid metropolitan area and other 80 from the Barcelona area. The EIA-Mabs technique made it possible to identify the G serotypes in 287 cases (89%), corresponding 207 to G1 serotype, 70 to G4 serotype and 6 to G3 serotype. In 4 patients both G1 and G4 serotypes were detected. The EIA-Mabs could not determined the serotype in 35 (11%) patients, all of whom were confirmed by RT-PCR (12 belonged to serotype G1 and 23 to serotype G4). Analysis of P genotypes was carried out in 25 patients obtained from Madrid and 17 from Barcelona; all cases were classified in the P[8] genotype. CONCLUSIONS: The most frequent serotype in both hospitals was G1. The EIA-Mabs technique were showed a high sensitivity, however, the RT-PCR technique used were even more efficient, making it possible for us to identify all the non-serotypable EIA-Mabs cases. The temporal study of circulating serotypes/genotypes of rotavirus is necessary to evaluate the efficiency of vaccines.

Acute Disease↗

[Prevalence of antimicrobial resistance in enterococci isolated from blood in Madrid (1994-1995)].

BACKGROUND: The aim of this study was to evaluate the antimicrobial resistance of enterococci isolated from blood samples in three hospitals in Madrid (Spain) from 1994 to 1995. METHODS: One hundred strains, 83 Enterococcus faecalis, 15 E. faecium, and 2 E. durans, isolated from January 1994 to April 1995 were studied. The minimum inhibitory concentrations (MIC) of 11 antimicrobians were determined by the agar dilution method. RESULTS: Four percent of the strains were resistant to ampicillin and 7% to penicillin. Ninety-two percent were sensitive to vancomycin. The percentage of strains with a high level of resistance (HLR) to some aminoglucoside was 60%. HLR was observed to gentamycin in 41%, to streptomycin in 46% and to kanamycin in 58% of the strains. Half of the isolates were resistant to the fluoroquinolones tested. HLR was significantly associated with aminoglucosides with HLR (MIC > or = 16 mg/l) to fluoroquinolones in the strains studied (p < 0.001). CONCLUSIONS: The incidence of resistance to ampicillin and vancomycin is low and very high to aminoglucosides and fluoroquinolones. There is also a very significant association between HLR to fluoroquinolones and HLR to aminoglucosides.

Bacteremia↗

Nosocomial outbreak of Burkholderia pickettii infection due to a manufactured intravenous product used in three hospitals.

Forty-six cases of nosocomial infection caused by Burkholderia pickettii were reported between June and November 1993 in three metropolitan hospitals in Madrid. A case-control study of the outbreak was conducted to identify its cause. Seventy-four percent of the patients were males; the mean age +/- SD of the patients was 54 +/- 20 years. Sixty-five percent of the patients presented with some gastrointestinal disorder, and 80% had a peripheral catheter; 98% were treated with intravenous fluids, and 96% were treated with intravenous ranitidine. On the basis of results of a descriptive study and knowledge of the epidemiologic features of B. pickettii, a provisional causal hypothesis was formulated: intravenous ranitidine was the source of the outbreak. As a control measure, it was advised to stop treatment with this drug. On the basis of results of logistic regression and the microbiological isolation of B. pickettii in an ampule of the drug, we concluded that intravenous ranitidine was the cause of the outbreak.

Adult↗

[Factors of pathogenicity, biotype, serotype and antimicrobial sensitivity of 150 clinical isolates of Yersinia enterocolitica (1992-1994)].

BACKGROUND: Yersinia enterocolitica is an important pathogen in temperate climates. The heterogeneity of the microorganisms covered by this denomination has a made grouping and identification schemes necessary. METHODS: A series of 150 different, consecutive isolates from patients with diarrheic syndrome living in an urban area with a population of approximately 500,000 inhabitants, were studied in order to evaluate their biochemical, antigenic and sensitivity characteristics. RESULTS: There was a high degree of uniformity among the strains isolated, 144 (96%) of which were identified as Yersinia enterocolitica sensu stricto, biotype 4, serotype 0:3. These strains presented, almost invariably, the same susceptibility pattern, being sensitive to amoxicillin/clavulanic acid, piperacillin, cefamandole, cefoxitin, gentamicin, amikacin, tetracycline and cotrimoxazole, and highly resistant to ampicillin, ticarcillin and cephazotin. In addition, 5 strains of Yersinia frederiksenii were isolated. The biochemical, epidemiological and sensitivity characteristics of these strains differed from those invariably found in the rest of the isolates. CONCLUSIONS: The data obtained in this study, shown a high degree of uniformity in the strains of Yersinia enterocolitica isolated in our area in recent years, with regard to both their biochemical characteristics and their sensitivity patterns. The isolations of the other biogroups may be regarded as extremely infrequent in the stool culture of patients with diarrhea treated in our hospitals.

Bacterial Typing Techniques↗

[Infection by HIV and the hepatitis B, C, and D viruses in intravenous drug addicts. Seroprevalence at 1 year and its follow-up].

BACKGROUND: The aim of the present article was to study the serology of intravenous drug user patients against the hepatitis B, C, D, and HIV, during 1990 and the follow-up during the same year, and 1991. METHODS: A study of 265 patients (mean age: 25 years, range: 16-45; 206 males and 59 females) was carried out. Forty-two percent came because of detoxication treatment, 30% requested diagnosis for hepatic disturbances and the only data provided in 28% were that they were intravenous drug users. None of the patients was an inmate from prisons. RESULTS: Seroprevalences were 67.5% for the HBV, 75.6% for HCV, 17% for HDV and 50.2% for HIV. In the patients seronegative for HBV (65%) and HIV (58%) no new serologic controls were performed during the study period, while in those who underwent controls the rates of seroconversion were 43.3% and 32%, respectively. In 30% of all seroconversions to HBV coinfection with HDV was found and in 23% antibodies against HIV were observed. CONCLUSIONS: Due to the high rates of infection obtained, the authors believe that serologic follow up of intravenous drug users is advisable.

Adolescent↗

Epidemic outbreak of Serratia marcescens infection in a cardiac surgery unit.

Between 2 February and 16 April 1985, an outbreak of Serratia marcescens infection involving 10 male patients occurred in a cardiac surgery unit. All the patients had surgical wound infection, five also had osteomyelitis (four sternal, one costal), and another had peritonitis secondary to peritoneal dialysis. Three patients had concomitant bacteremia. All Serratia strains isolated produced a cherry-red pigment, and all had the same biochemical and antibiotic susceptibility pattern. An intensive search for the origin of the outbreak was initially unsuccessful, and it proved impossible to isolate S. marcescens from cultures of numerous samples taken from hospital personnel and from the environment. The fact that all patients were male and had been shaved for surgery by the same team of barbers led us to investigate the shaving procedures. We finally isolated a strain of pigmented S. marcescens, corresponding to that involved in the outbreak, from samples taken from the hands and equipment of the barbers. After suitable action had been taken, the epidemic terminated.

Barbering↗

Antimicrobial susceptibility of Corynebacterium group D2.

The in vitro susceptibility of 30 Corynebacterium group D2 strains to nine antimicrobial agents was determined. Vancomycin and norfloxacin were the most active agents tested. All strains were resistant to ampicillin and cephalothin, all except one were resistant to gentamicin, and the activity of erythromycin, novobiocin, tetracycline, and rifampin varied.

Anti-Bacterial Agents↗

Corynebacterium group D2 as a cause of alkaline-encrusted cystitis: report of four cases and characterization of the organisms.

In four patients with alkaline-encrusted cystitis, Corynebacterium group D2 was isolated from consecutive urine cultures and stones. Encrusted cystitis occurred in bladders harboring inflammatory or tumorous lesions in patients with chronic or recurrent urinary tract infections appearing after surgery or instrumentation. The urease activity of Corynebacterium group D2 and the neutralization of this enzyme by acetohydroxamic acid are shown. Clinical improvement, disappearance of struvite crystals, and decrease of the urine pH were obtained when these bacteria were eliminated from urine samples. Corynebacterium group D2 strains were highly resistant to many antimicrobial agents but were highly susceptible to norfloxacin and vancomycin when tested at two pHs (7.4 and 8.5).

Aged↗