1/18. Extended-spectrum beta-lactamase-producing klebsiella pneumoniae in a Dublin paediatric hospital.klebsiella pneumoniae resistant to third-generation cephalosporins and gentamicin was isolated from two patients in a paediatric intensive care unit within a two-week period. The double-disc diffusion test indicated the presence of an extended-spectrum beta-lactamase (ESBL). The unit was closed to admissions, and stringent infection control procedures were implemented. Environmental screening and screening of staff and patients on the unit were commenced. Two weeks later, K. pneumoniae with an identical antibiogram was isolated from the urine of a patient in a different ward. blood-culture isolates possessed the K16 antigen, while the urine isolate was non-typeable. The isolates were shown to be similar when banding patterns of XbaI chromosomal dna digests were compared. The resistance to the extended-spectrum cephalosporins was shown to be transferable in association with a large plasmid > 98 mDa. Resistance to gentamicin always co-transferred with beta-lactamase resistance and appeared to be encoded by the same plasmid.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/18. Three cases of severe subfulminant hepatitis in heart-transplanted patients after nosocomial transmission of a mutant hepatitis b virus.Fulminant and severe viral hepatitis are frequently associated with mutant hepatitis b virus (HBV) strains. In this study, the genetic background of a viral strain causing severe subfulminant outcome in heart-transplanted patients was studied and compared with viral hepatitis B strains that were not linked to severe liver disease in the same setting. A total of 46 patients infected nosocomially with HBV genotype A were studied. Five different viral strains were detected, infecting 3, 9, 5, 24, and 5 patients, respectively. Only one viral strain was found to be associated with the subfulminant outcome and 3 patient deaths as a consequence of severe liver disease. The remaining 43 patients with posttransplantation HBV infection did not show this fatal outcome. Instead, symptoms of hepatitis were generally mild or clinically undiagnosed. Comparison of this virus genome with the four other strains showed an accumulation of mutations in the basic core promoter, a region that influences viral replication, but also in hepatitis B X protein (HBX) (7 mutant motifs), core (10 mutant motifs), the preS1 region (5 mutant motifs), and the HBpolymerase open reading frame (17 motifs). Some of these variations, such as those in the core region, were located on the tip of the protruding spike of the viral capsid (codons 60 to 90), also known in part as an important HLA class II-restricted epitope region. These mutations might therefore influence the immune-mediated response. The viral strain causing subfulminant hepatitis was, in addition, the only strain with a preCore stop codon mutation and, thus, hepatitis B e antigen (HBeAg) expression was never observed. The combination of these specific viral factors is thought to be responsible for the fatal outcome in these immune-suppressed heart-transplant recipients.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/18. Multiple types of legionella pneumophila serogroup 6 in a hospital heated-water system associated with sporadic infections.Five sporadic cases of nosocomial legionnaires' disease were documented from 1989 to 1997 in a hospital in northern italy. Two of them, which occurred in a 75-year-old man suffering from ischemic cardiopathy and in an 8-year-old girl suffering from acute leukemia, had fatal outcomes. legionella pneumophila serogroup 6 was isolated from both patients and from hot-water samples taken at different sites in the hospital. These facts led us to consider the possibility that a single clone of L. pneumophila serogroup 6 had persisted in the hospital environment for 8 years and had caused sporadic infections. Comparison of clinical and environmental strains by monoclonal subtyping, macrorestriction analysis (MRA), and arbitrarily primed PCR (AP-PCR) showed that the strains were clustered into three different epidemiological types, of which only two types caused infection. An excellent correspondence between the MRA and AP-PCR results was observed, with both techniques having high discriminatory powers. However, it was not possible to differentiate the isolates by means of ribotyping and analysis of rrn operon polymorphism. Environmental strains that antigenically and chromosomally matched the infecting organism were present at the time of infection in hot-water samples taken from the ward where the patients had stayed. Interpretation of the temporal sequence of events on the basis of the typing results for clinical and environmental isolates enabled the identification of the ward where the patients became infected and the modes of transmission of Legionella infection. The long-term persistence in the hot-water system of different clones of L. pneumophila serogroup 6 indicates that repeated heat-based control measures were ineffective in eradicating the organism.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/18. Pneumococcal arthritis affects performance status in patients with chronic GVHD of the skin following allogeneic bone marrow transplantation.We encountered 2 patients with pneumococcal arthritis following bone marrow transplantation (BMT). Both patients received grafts from unrelated human lymphocyte antigen (HLA)-matched donors and had suffered from chronic graft-versus-host disease (GVHD). One, a 10-year-old boy, suffered from Epstein-Barr virus-related lymphoproliferative disease (EB-LPD) and received oral 6-mercaptopurine and methotrexate to manage lymphadenopathy. Twenty-four months after BMT and 7 months after the onset of EB-LPD, pneumococcal arthritis occurred in both knee joints. The other patient, a 10-year-old girl, received multiagent immunosuppressive therapy for her chronic GVHD. At 51 months following BMT, pneumococcal arthritis occurred in her left knee joint. Chronic GVHD of the skin delayed the recovery from the arthritis in both patients. This complication is quite rare but can be very serious, in regard to the patient's performance status following BMT. Although vaccination against pneumococcus or preventive antibiotics should be administered to high-risk patients, early diagnosis and treatment may be the best strategy for pneumococcal arthritis.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/18. Prolonged shedding of rotavirus in a geriatric inpatient.This study concerns a nosocomial rotaviral infection of a geriatric patient with clinical symptoms of acute gastroenteritis. The virological diagnosis was based on the detection of rotaviral antigens using a Rota kit, viral genome rna by reverse transcription-polymerase chain reaction method, and viral particles by electron microscopy in the stool samples. Prolonged rotaviral shedding was suggested to be due to impaired natural killer cell activity, possibly together with deficiency of specific local immune response of the patient.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/18. Correlation of antigenic expression with progress in antibiotic therapy of acute human brucellosis.Human brucellosis is a zoonotic disease which is endemic in saudi arabia. The aim of this study was to investigate the humoral immune responses and identify the target antigens that persist at different stages in human brucellosis during antibiotic therapy. To do this, an acute case of accidental nosocomial infection was studied experimentally. blood was collected from the patient at the time of diagnosis, and at weekly intervals during therapy until remission. IgG and IgM immunoblotting was used to characterize specific antigenic determinants, and ELISA antibody titration was performed to quantify the circulating antibodies. Results indicated that protein bands of 12-13.5 kDa bound IgG in the patient's sera but did not bind IgM on immunoblots and are probably not specific for, or important in, early stage infections. However, an 18 kDa band persisted during infection through remission. The pivotal and most important findings were that the number of protein bands seen on immunoblots, the magnitude of ELISA antibody titres and the concomitant changes in the intensity of the polypeptide bands of 42-43 kDa were positively correlated with the stage of infection. High numbers of anti-IgG and -IgM immunoblot bands coupled with high ELISA antibody titres and a concomitant increase in intensity of the 42-43 kDa bands were positively correlated with acute and severe infection. Conversely, a reduction in the number of polypeptide bands as well as a decrease in the intensity, until the complete disappearance of the 42-43 kDa bands, coupled with low (baseline) ELISA antibody titration values indicated successful treatment and remission. The routine use of the methods described here to ascertain the stage of the disease, assess the progress of antimicrobial therapy and monitor cases of relapse in human brucellosis is suggested.- - - - - - - - - - ranking = 6keywords = antigen (Clic here for more details about this article) |
7/18. legionella pneumophila serogroup 12 pneumonia in a renal transplant recipient: case report and environmental observations.We describe the first reported case of pneumonia due to legionella pneumophila serogroup 12 in the UK. This hospital-associated infection occurred in an immuno-incompetent patient and coincided with a change in character of the local environmental strains of legionellas. The patient produced a serological response both to her own isolate and to L. pneumophila serogroups 1-6. Thus serodiagnosis was attainable using the usual screening antigens.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/18. Nosocomial epidemic of active tuberculosis among hiv-infected patients.In an investigation of a nosocomial outbreak of tuberculosis, 18 hiv-infected inpatients were found to have been exposed to mycobacterium tuberculosis; active tuberculosis developed in 8, 7 within 60 days of diagnosis of the index case. The patients with lower total lymphocyte and CD4 lymphocyte counts were more likely to get the disease than were those with higher counts. A low score on multiple antigen skin testing was also associated with the development of active tuberculosis. 4 of the 18 patients had a positive tuberculin skin test before exposure to M tuberculosis; none of them subsequently got the disease.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/18. Reinfection with varicella-zoster virus in immunocompromised patients.A small epidemic of varicella/atypical generalized zoster among 6 immunocompromised patients and one previously healthy person is described. The 6 immunocompromised patients suffered from lymphoproliferative diseases in terminal stages treated with chemotherapy and reported varicella in their childhood. They developed a generalized maculopapular rash with hemorrhagic bullae and necroses. The infection passed from one patient to another during a 3-month period in the department. They were placed in adjacent rooms and nursed by the same staff. The most specific diagnostic tool was the detection of varicella-zoster virus antigen from vesicles by ELISA technique. The epidemic was supposed to be caused by exogenous reinfection with varicella-zoster virus, and illustrated that generalized zoster may be even so infectious as varicella and that immunocompromised patients should be protected against reinfection.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/18. Nosocomial transmission of delta hepatitis.A previously asymptomatic carrier of hepatitis b virus receiving chronic hemodialysis developed acute delta hepatitis. The patient regularly received dialysis treatments on the same machine as a parenteral drug abuser with hepatitis B surface antigen (HBsAg)-positive chronic hepatitis whose serum was strongly positive for delta antibody. The drug abuser had a major bleeding episode that caused extensive environmental contamination 3 months before onset of illness in the index patient. No other patients receiving dialysis or staff members had evidence of delta infection. A surgeon previously infected with hepatitis B from the same parenteral drug abuser also had delta antibody. Testing for delta virus is indicated for both HBsAg-positive parenteral drug abusers and patients with hemophilia receiving chronic hemodialysis. All patients who are HBsAg- and delta-positive should receive dialysis separately from patients who are HBsAg-positive and delta-negative. Susceptible patients on dialysis and staff should receive hepatitis B vaccine to protect against both hepatitis B and delta virus infection.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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