Microbiologica最新文献

A case of deep keratomycosis with isolation of Rhodotorula glutinis is discussed. Keratoplasty, done immediately, prevented panophthalmitis and cured the patient. The etiology and pathogenesis of fungal keratitis is examined.

The incidence of meningococcal disease in Italy in 1990 was 0.5/100,000 in the general population and 0.7/100,000 in army recruits. The highest proportion of cases (32%) was seen in subjects 1-4 years old. The sex ratio was 1.0 Serogroup B constituted 72% of the isolates; 16% belonged to group A and 12% belonged to group C. The proportion of strains resistant to suphonamides was 56%, while no strain was resistant to minocycline or rifampicin. Two secondary cases, but no comprimary cases occurred among civilians. The predominance of serogroup B and the further decline in military cases constitute the findings of major interest.

Borrelia burgdorferi and Borrelia hermsii were treated with the following detergents: sodium dodecyl sulphate (SDS), N-lauryl sarcosine (Sarkosyl) and Triton X-100, and the soluble and insoluble fractions obtained after each detergent treatment were examined by sodium dodecyl sulphate polyacrylamide gel electrophoresis. Sarkosyl as well as SDS solubilized all Borrelia proteins, whereas Triton X-100 treatment selectively solubilized the majority of other borrelial proteins, leaving two proteins of 41 kDa and 66 kDa in Borrelia burgdorferi and one protein of 39 kDa in Borrelia hermsii associated with the Triton X-100 insoluble fraction.

At the end of 1985, when the AIDS epidemic was in its early stages in Uganda, a survey was carried out in a peripheral area of the country. Sera were collected from groups of people, and examined for the presence of HIV infection. The results show a very limited number of positive cases, present only among sexually active subjects. High specificity and sensitivity in the laboratory tests was shown by the Western blot technique.

A number of experimental data demonstrate that certain mammalian cells are unable to replicate Influenza viruses type A. In these cellular hosts the viruses can efficiently perform their biological as well as biochemical activities but the production of mature viral particles is greatly restricted. Here we report a study of abortiveness of human and avian type A Influenza viruses in HeLa 229 cells in which the final stages of maturation of viral particles seem to be affected. We show that the incorrect insertion of virus-coded haemagglutinin into the plasma membrane might be the cause of the unpermissive condition of infection exhibited by this cellular host.

Human cytomegalovirus can support an abortive infection in Vero cells and only some immediate early events are expressed in a low proportion of the cell population. It has been shown that cellular factors partially remove blocks in cells abortively or latently infected by HCMV, whereas 5-azacytidine is known to act on gene expression and cell differentiation. In this work we present evidence that the treatment of HCMV infected Vero cells with 5-azacytidine induces the expression of the major immediate early protein (68K) of Human cytomegalovirus by enhancing a 72K cellular heat shock protein.

HIV infection is thought to exacerbate the virulence of normal saprophytic vaginal microflora. We studied the vaginal ecosystem of HIV patients to detect the quantitative and qualitative variation of vaginal microorganisms. 15 patients (5 with AIDS and 10 with ARC) were investigated. Vaginal candidiasis was more frequent in this group than in the control groups. Gardnerella was present in 60% of patients generally in association with anaerobic bacteria and Mycoplasma. Among anaerobia, Bacteroides sp and other Gram-negative rods were the most common bacteria. Neisseria gonorrhoeae was absent in all patients tested. Chlamydia trachomatis was recovered in two out of the 15 HIV-positive patients. Aerobic Gram-negative flora was 100-fold that of the control group and anaerobic Gram-negative flora 10-fold.

P. aeruginosa is highly resistant to a wide range of antimicrobial agents. This intrinsic resistance mainly depends on the rate of permeation across the outer membrane (o.m.). In order to promote antibiotic uptake across the hydrophilic channel of the o.m. porins, a permeator can be used with a hydrophilic antibiotic. In the present study we assess the o.m. electrophoretic profile of three P. aeruginosa strains cultured with and without antibiotic Aztreonam and Netilmicin (A:N) using the MIC concentration in the association (3:1). The observed increase in the band can be referred to the F porin when the strains are treated with Aztreonam.

Infections caused by commensal microorganisms, such as Candida albicans often represent a severe complication in pharmacologically immunosuppressed kidney transplanted patients. A mannoprotein (MP) antigenic preparation derived from the C. albicans cell wall was used to measure the specific immune responsiveness in 44 kidney transplanted patients and matched healthy controls. Patients immune responses were analyzed considering the transplant age. In group I, patients transplanted from greater than 1 month to less than 12 months were considered, whereas in groups II and III patients had been transplanted 1 to 3 years or 4 to 6 years earlier. A statistically significant low responsiveness to MP was recorded in peripheral blood mononuclear cells (PBMC) from patients belonging to groups II and III. Addition of exogenous IL-2 to PBMC cultures restored MP-induced proliferation in about 50% of patients studied. Responsiveness to mitogenic stimulation (PHA and SEB) was in the normal range in all transplanted patients. No correlation could be detected between hyporesponsiveness to MP and C. albicans infections.

Strains of Staphylococcus aureus isolated from lesions and apparently healthy animals, human diarrhoea and wounds in Nigeria were phage typed and tested for exfoliative toxin (ET) production using the modified Ouchterlony double diffusion test. Thirty-four (4.0%) of 860 strains tested produced exfoliative toxins A (ETA), B (ETB) or a combination. ETA was produced singly by 91.1% of the toxigenic strains. Twenty-six (3.9%) of 666 animal strains were toxigenic compared to 8 (4.4%) of 194 strains from human beings. Overall, a majority of ET-producing strains were non-typable (58.8%), followed by phage group II strains (17.7%). The detection of a similar frequency of production of ET by strains of S. aureus from animals and non-scalded skin syndrome cases indicates that animals may serve as a reservoir for human infection.