Increased frequency of JC virus type 2 and of dual infection with JC virus type 1 and 2 in Italian progressive multifocal leukoencephalopathy patients.

To verify the possibility of different role of JC virus genotypes in the etiology of progressive multifocal leukoencephalopathy, we analysed several JC virus isolates amplified from AIDS patients with and without progressive multifocal leukoencephalopathy and healthy controls by nucleotide sequencing. Cerebrospinal fluid (CSF), peripheral blood mononuclear cells (PBMCs) and urine from 52 AIDS patients suffering from various neurological diseases including 21 cases of progressive multifocal leukoencephalopathy, and PBMCs and urine from healthy subjects were evaluated by nested polymerase chain reaction (PCR) for the presence of DNA belonging to the highly conserved large T antigen (LT) of JC virus. The different JC virus subtypes were identified by nucleotide sequence analysis of the virion protein (VP1) genomic region. JC virus DNA was detected in all the CSF samples from the progressive multifocal leukoencephalopathy patients, but not in the CSF from non-progressive multifocal leukoencephalopathy cases, while the frequency of JC virus DNA detection in the PBMCs and urine did not differ among the three groups studied. JC virus type 2 was detected only in progressive multifocal leukoencephalopathy patients, and in particular in 52.4% of their CSF samples. Moreover, in the CSF of 19.0% of the progressive multifocal leukoencephalopathy cases, dual infection with both JC virus types 1 and 2 was found. The data obtained in this study indicate that the unexpected involvement of JC virus type 2, a strain not common in Italy, and the high frequency of dual infection with both JC virus types 1 and 2 in progressive multifocal leukoencephalopathy CSF, can be indications of risk factors for progressive multifocal leukoencephalopathy development.

The effectiveness of desensitization versus rechallenge treatment in HIV-positive patients with previous hypersensitivity to TMP-SMX: a randomized multicentric study. C.I.S.A.I. Group.

Our study was undertaken to evaluate if desensitization treatment is more effective than rechallenge in preventing hypersensitivity reactions in HIV-positive patients with previous allergic reactions to TMP-SMX; the secondary aim was to evaluate the frequency of reactions to TMP alone. This was a randomized, multicentre open study. Patients with previous documented hypersensitivity to TMP-SMX who required primary or secondary PCP prophylaxis were enrolled; subjects who had previously had serious adverse reactions to TMP-SMX were excluded. All eligible patients assumed 200 mg TMP for 14 days and in case of no reactions were randomized for desensitization or rechallenge with TMP-SMX. The patients were then followed up by periodical visits for six months. Seventy-three patients were enrolled; 14 subjects (19%) presented reactions on TMP alone during the pre-enrollment phase. The remaining 59 subjects were randomly assigned to the two treatment groups: 34 carried out desensitization (group 1) and 25 rechallenge (group 2) with TMP-SMX. Seven patients in group 1 (20.5%) and seven in group 2 (28%) showed hypersensitivity reactions during treatment; this difference was not statistically significant. No serious reaction occurred in either group. This study showed the comparable effectiveness of the desensitization procedure and rechallenge in patients with a previous, not serious, allergic reaction to TMP-SMX.

Acetylator phenotype prevalence in HIV-infected patients without previous trimethoprim-sulfamethoxazole hypersensitivity.

This trial was conducted to study the frequency of the slow acetylator phenotype in asymptomatic HIV patients having no previous reaction to sulfa-drugs, and to compare this frequency with the frequency found in healthy controls. Results show that HIV alone is not capable of modifying the acetylator phenotype; the prevalence of slow acetylator phenotype is the same in immune competent subjects and HIV-positive patients. It is more common in HIV-positive patients with a CD4+ lymphocyte count of less than 200 mm-3.

Mycobacterium genavense in AIDS patients, report of 24 cases in Italy and review of the literature.

Mycobacterium genavense is a frequently missed agent of disseminated disease in AIDS patients. The increasing frequency with which such organism is being isolated in Italy suggested a comparison of local survey with data reported in literature. Isolates presumed to belong to the species M. genavense were centralized and identified by means of genomic sequencing and/or HPLC analysis of cell wall mycolic acids; clinical data were obtained from relevant patients' record and collected using a proper questionnaire. In 24 cases in which this organism has been isolated in Italy M. genavense was grown, prevalently from blood, in liquid medium after an average of six weeks of incubation. In overwhelming majority, patients were males, presented other opportunistic diseases and were characterized by very low CD4+ counts (average 23/microl); most frequent symptoms were fever, anemia and weight loss. All but two patients, who died before the mycobacterial infection was diagnosed, were treated with at least three drugs; the mean survival was close to one year. A review of literature reports revealed a wide overlapping of clinical and microbiological features.

Comprehensive investigation of the presence of JC virus in AIDS patients with and without progressive multifocal leukoencephalopathy.

Progressive multifocal leukoencephalopathy (PML), a viral-induced demyelinating disease, is becoming relatively common, while many diagnostic and pathogenetic aspects remain to be clarified. A study was therefore undertaken in 64 AIDS patients suffering from various neurological disorders, including PML (12 subjects), with the specific objective of searching for JC virus (JCV) DNA by nested PCR (n-PCR) in cerebrospinal fluid (CSF), peripheral blood mononuclear cells (PBMCs), and urine collected from all patients. CSF examination, CD4 and CD8 counts, neurological examinations, and neuroradiological investigations were undertaken. JCV DNA was detected in 92% of CSF specimens in 75% of the PBMCs and urine samples from the PML patients, whereas among the non-PML patients JCV DNA was not detected in any CSF samples, but was found in 10% of PBMCs and in 39% of the urine specimens. BKV and JCV DNA viruria was observed simultaneously in 6% of the AIDS patients without PML. The routine CSF tests including IgG oligoclonal bands, the Link, and Tourtellotte IgG indexes, did not show a typical pattern in PML cases. The data obtained clearly indicate that the detection of JCV DNA in CSF constitutes an efficient marker for PML diagnosis. The simultaneous presence of JCV DNA in the CSF, PBMCs, and urine samples from the PML patients, who did not differ from controls with regard to their immunosuppressive status, suggests that JCV could be carried into the central nervous system (CNS) by infected PBMCs.

Sparfloxacin therapy for experimental endocarditis caused by methicillin-resistant Staphylococcus aureus.

Sparfloxacin, a new difluorinated quinolone antibiotic, was employed in the treatment of catheter-induced endocarditis in rabbits infected with a methicillin-resistant strain of Staphylococcus aureus (MRSA). Animals (n = 12) in the study group received sparfloxacin, 25 mg/kg body weight every 12 h intravenously. Comparison groups were untreated controls (n = 9) and animals injected with vancomycin (n = 13) at the same dosage. MICs and MBCs of the test organism were both 1.56 mg/l for vancomycin and 0.15/0.30 mg/l for sparfloxacin. Antibiotic treatments started 24 h after bacterial challenge and lasted 4 days until sacrifice. In comparison with no treatment, both sparfloxacin and vancomycin significantly reduced the bacterial counts in aortic vegetations, while no significant difference was found between the two antibiotics. Combination of the two antibiotics, tried in a smaller group of rabbits (n = 3) showed no advantages over either single-drug therapy. Our results suggest that sparfloxacin is a potentially useful agent, at least in the rabbit model, for treating MRSA endocardial infections.

Comparison of sparfloxacin, temafloxacin, and ciprofloxacin for prophylaxis and treatment of experimental foreign-body infection by methicillin-resistant Staphylococcus aureus.

The prophylactic and therapeutic activities of three broad-spectrum fluoroquinolones were evaluated in two different experimental models of foreign-body infections caused by methicillin-resistant Staphylococcus aureus (MRSA) susceptible to quinolones. In a guinea pig model of prophylaxis, subcutaneously implanted tissue cages were infected at a > 90% rate by 10(2) CFU of MRSA in control animals. A single dose of 50 mg of ciprofloxacin per kg of body weight administered intraperitoneally 3 h before bacterial challenge was less effective than an equivalent regimen of either sparfloxacin or temafloxacin in decreasing the rate of experimental infection in tissue cages challenged with increasing inocula of MRSA. In a rat model evaluating the therapy of chronic tissue cage infection caused by MRSA, the efficacy of a 7-day high-dose (50-mg/kg twice-daily) regimen of sparfloxacin, temafloxacin, or ciprofloxacin was compared to that of vancomycin (50 mg/kg twice daily). Active levels of sparfloxacin, temfloxacin, or ciprofloxacin were continuously present in tissue cage fluid during therapy, exceeding their MBCs for MRSA by 6- to 20-fold. Either temafloxacin, sparfloxacin, or vancomycin was significantly (P < 0.01) more active than ciprofloxacin in decreasing the viable counts of MRSA in tissue cage fluids. The different activities of ciprofloxacin compared with those of the other two quinolones against chronic tissue cage infections caused by MRSA did not involve the selective emergence of quinolone-resistant mutants. Temafloxacin and ciprofloxacin, which showed the most prominent differences in their in vivo activities, however, exhibited similar bactericidal properties and pharmacokinetic parameters in the rat model. In conclusion, both temafloxacin and sparfloxacin were significantly more active than ciprofloxacin for the prophylaxis or treatment of experimental foreign-body infections caused by a quinolone-susceptible strain of MRSA.