Monotherapy with isoniazid or amikacin or clarithromycin or combinations of two of these drugs sh... more Monotherapy with isoniazid or amikacin or clarithromycin or combinations of two of these drugs showed nil to modest therapeutic activity in beige mice infected with Mycobacterium avium. However, the combination of all three, isoniazid-amikacin-clarithromycin, markedly reduced CFUs in both spleens and lungs after 91 days of infection.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2008
Quality assurance for the World Health Organization (WHO)/International Union Against Tuberculosi... more Quality assurance for the World Health Organization (WHO)/International Union Against Tuberculosis and Lung Disease (The Union) global tuberculosis (TB) drug resistance surveillance programme. To monitor the quality of drug susceptibility testing (DST) in different countries. In 2002-2003 and 2005-2006, 20 Mycobacterium tuberculosis strains were sent by the WHO/Union Supranational Reference Laboratory of Rome to TB reference laboratories in Albania, Bahrain, Kosovo, Mozambique, Oman, Qatar and Turkey for external quality control (EQC). In 2002-2003, the specificity, sensitivity, efficiency, reproducibility and predictive values for resistance/susceptibility were >or=90% for streptomycin (SM), isoniazid (INH) and ethambutol (EMB). In 2005-2006, all statistical values were >or=96% for SM, INH, rifampicin and EMB. EQC improved the quality of M. tuberculosis DST in the participating countries.
The groES gene of Mycobacterium avium strain 485 was cloned and expressed in Escherichia coli and... more The groES gene of Mycobacterium avium strain 485 was cloned and expressed in Escherichia coli and the recombinant GroES protein was purified by affinity chromatography. The GroES preparation showed high purity by electrophoresis and immunoblotting. Immuno-electron microscopy showed that GroES was located both in the cytoplasm and on the surface of the mycobacterial cells and thus is readily available to interact with the host immune system. BALB/c mice were immunised intranasally with recombinant GroES, alone or in combination with a synthetic oligodeoxynucleotide containing unmethylated CpG motifs, and tested for protection against infection with M. avium. Neither GroES nor CpG alone provided any protection against subsequent challenge with M. avium, whereas a combination of the two significantly protected the lungs and spleen against colonisation by M. avium after intranasal challenge with a low dose of the organism. This indicates that intranasal administration of GroES and CpG o...
BALB/c mice exposed intranasally (i.n.), intradermally (i.d.) or intraperitoneally (i.p.) to low ... more BALB/c mice exposed intranasally (i.n.), intradermally (i.d.) or intraperitoneally (i.p.) to low doses of Mycobacterium avium (20 c.f.u. at three different times two weeks apart) showed an increased resistance to a subsequent high-dose (10(5) c.f.u.) infection. I.n.-exposed mice had few mycobacteria in the tissues (>100 c.f.u.) and showed an expansion of CD4(+) T cells associated with overproduction of IL-12 and IFN-gamma, but not IL-4 and IgG antibodies. Parenterally (i.p. and i.d.) exposed animals showed c.f.u. numbers higher than i.n.-exposed mice, together with overproduction of IL-12, IFN-gamma and IL-4 in the case of i.p.-exposed mice, and of IL-12, IFN-gamma and IgG2a and IgG1 antibodies in the case of i.d.-exposed mice. Low-dose exposures were not contained by athymic BALB/c nude mice; however, naive nude mice reconstituted with i.n.-primed CD4(+) T cells of BALB/c mice were protected against high-dose infection, indicating that CD4(+) T cells are essential to control eve...
Typing of the glycopeptidolipid antigens performed by thin layer chromatography on 59 Mycobacteri... more Typing of the glycopeptidolipid antigens performed by thin layer chromatography on 59 Mycobacterium avium-intracellulare (MAC) strains isolated in Italy from AIDS patients showed that the most frequent types were 1, 4, 3, 8, and 21 (24, 19, 14, 14 and 8% of the strains, respectively). Among non-AIDS patients, types 1, 4 and 8 were also frequently found. The antimicrobial susceptibility tested in agar and/or liquid media to a panel of drugs indicated in clofazimine and rifabutin effective agents against both AIDS and non-AIDS strains. The data obtained show that MAC type distribution in Italy appears to be different from that reported for other countries. No major differences in drug susceptibility between AIDS and non-AIDS related strains were found.
Dendritic cells (DCs) are critical for initiating a pathogen-specific T-cell response. During chr... more Dendritic cells (DCs) are critical for initiating a pathogen-specific T-cell response. During chronic infections the pool of tissue DCs must be renewed by recruitment of both circulating DC progenitors and in loco differentiating monocytes. However, the interaction of monocytes with pathogens could affect their differentiation. Mycobacterium tuberculosis has been shown to variably interfere with the generation and function of antigen-presenting cells (APCs). In this study we found that when alpha interferon (IFN-alpha) is used as an inductor of monocyte differentiation, M. tuberculosis inhibits the generation of DCs, forcing the generation of immunoprivileged macrophage-like cells instead. Cells derived from M. tuberculosis-infected monocyte-derived macrophages (M. tuberculosis-infected MoMphi) retained CD14 without acquiring CD1 molecules and partially expressed B7.2 but did not up-regulate B7.1 and major histocompatibility complex (MHC) class I and II molecules. They synthesized tumor necrosis factor alpha and interleukin-10 (IL-10) but not IL-12. They also showed a reduced ability to induce proliferation and functional polarization of allogeneic T lymphocytes. Thus, in the presence of IFN-alpha, M. tuberculosis may hamper the renewal of potent APCs, such as DCs, generating a safe habitat for intracellular growth. M. tuberculosis-infected MoMphi, in fact, showed reduced expression of both signal 1 (CD1, MHC classes I and II) and signal 2 (B7.1 and B7.2), which are essential for mycobacterium-specific T-lymphocyte priming and/or activation. These data further suggest that M. tuberculosis has the ability to specifically interfere with monocyte differentiation. This ability may represent an effective M. tuberculosis strategy for eluding immune surveillance and persisting in the host.
The in vitro antibacterial activity of zidovudine alone and in combination with ciprofloxacin was... more The in vitro antibacterial activity of zidovudine alone and in combination with ciprofloxacin was investigated. Zidovudine showed a good activity against Escherichia coli and Salmonella (MIC range 0.5-8 micrograms/ml and 1.5-62 micrograms/ml respectively) isolated from biological samples of HIV-infected patients. These strains proved to be extremely susceptible to ciprofloxacin alone. The interaction between zidovudine and ciprofloxacin ranged from additive activity to indifference. No antagonism was observed: the FIC index for every combination resulted < or = 1.5. The addition of AZT 1 mg/l (clinically achievable plasma concentration after therapeutic doses of 1200 mg/day) did not affect the bactericidal activity of ciprofloxacin; on the contrary, in some cases we observed an increase of bactericidal effect of the quinolone. These data have to be considered in patients with AIDS who can be treated concomitantly with zidovudine and ciprofloxacin.
Monotherapy with isoniazid or amikacin or clarithromycin or combinations of two of these drugs sh... more Monotherapy with isoniazid or amikacin or clarithromycin or combinations of two of these drugs showed nil to modest therapeutic activity in beige mice infected with Mycobacterium avium. However, the combination of all three, isoniazid-amikacin-clarithromycin, markedly reduced CFUs in both spleens and lungs after 91 days of infection.
The international journal of tuberculosis and lung disease : the official journal of the International Union against Tuberculosis and Lung Disease, 2008
Quality assurance for the World Health Organization (WHO)/International Union Against Tuberculosi... more Quality assurance for the World Health Organization (WHO)/International Union Against Tuberculosis and Lung Disease (The Union) global tuberculosis (TB) drug resistance surveillance programme. To monitor the quality of drug susceptibility testing (DST) in different countries. In 2002-2003 and 2005-2006, 20 Mycobacterium tuberculosis strains were sent by the WHO/Union Supranational Reference Laboratory of Rome to TB reference laboratories in Albania, Bahrain, Kosovo, Mozambique, Oman, Qatar and Turkey for external quality control (EQC). In 2002-2003, the specificity, sensitivity, efficiency, reproducibility and predictive values for resistance/susceptibility were >or=90% for streptomycin (SM), isoniazid (INH) and ethambutol (EMB). In 2005-2006, all statistical values were >or=96% for SM, INH, rifampicin and EMB. EQC improved the quality of M. tuberculosis DST in the participating countries.
The groES gene of Mycobacterium avium strain 485 was cloned and expressed in Escherichia coli and... more The groES gene of Mycobacterium avium strain 485 was cloned and expressed in Escherichia coli and the recombinant GroES protein was purified by affinity chromatography. The GroES preparation showed high purity by electrophoresis and immunoblotting. Immuno-electron microscopy showed that GroES was located both in the cytoplasm and on the surface of the mycobacterial cells and thus is readily available to interact with the host immune system. BALB/c mice were immunised intranasally with recombinant GroES, alone or in combination with a synthetic oligodeoxynucleotide containing unmethylated CpG motifs, and tested for protection against infection with M. avium. Neither GroES nor CpG alone provided any protection against subsequent challenge with M. avium, whereas a combination of the two significantly protected the lungs and spleen against colonisation by M. avium after intranasal challenge with a low dose of the organism. This indicates that intranasal administration of GroES and CpG o...
BALB/c mice exposed intranasally (i.n.), intradermally (i.d.) or intraperitoneally (i.p.) to low ... more BALB/c mice exposed intranasally (i.n.), intradermally (i.d.) or intraperitoneally (i.p.) to low doses of Mycobacterium avium (20 c.f.u. at three different times two weeks apart) showed an increased resistance to a subsequent high-dose (10(5) c.f.u.) infection. I.n.-exposed mice had few mycobacteria in the tissues (>100 c.f.u.) and showed an expansion of CD4(+) T cells associated with overproduction of IL-12 and IFN-gamma, but not IL-4 and IgG antibodies. Parenterally (i.p. and i.d.) exposed animals showed c.f.u. numbers higher than i.n.-exposed mice, together with overproduction of IL-12, IFN-gamma and IL-4 in the case of i.p.-exposed mice, and of IL-12, IFN-gamma and IgG2a and IgG1 antibodies in the case of i.d.-exposed mice. Low-dose exposures were not contained by athymic BALB/c nude mice; however, naive nude mice reconstituted with i.n.-primed CD4(+) T cells of BALB/c mice were protected against high-dose infection, indicating that CD4(+) T cells are essential to control eve...
Typing of the glycopeptidolipid antigens performed by thin layer chromatography on 59 Mycobacteri... more Typing of the glycopeptidolipid antigens performed by thin layer chromatography on 59 Mycobacterium avium-intracellulare (MAC) strains isolated in Italy from AIDS patients showed that the most frequent types were 1, 4, 3, 8, and 21 (24, 19, 14, 14 and 8% of the strains, respectively). Among non-AIDS patients, types 1, 4 and 8 were also frequently found. The antimicrobial susceptibility tested in agar and/or liquid media to a panel of drugs indicated in clofazimine and rifabutin effective agents against both AIDS and non-AIDS strains. The data obtained show that MAC type distribution in Italy appears to be different from that reported for other countries. No major differences in drug susceptibility between AIDS and non-AIDS related strains were found.
Dendritic cells (DCs) are critical for initiating a pathogen-specific T-cell response. During chr... more Dendritic cells (DCs) are critical for initiating a pathogen-specific T-cell response. During chronic infections the pool of tissue DCs must be renewed by recruitment of both circulating DC progenitors and in loco differentiating monocytes. However, the interaction of monocytes with pathogens could affect their differentiation. Mycobacterium tuberculosis has been shown to variably interfere with the generation and function of antigen-presenting cells (APCs). In this study we found that when alpha interferon (IFN-alpha) is used as an inductor of monocyte differentiation, M. tuberculosis inhibits the generation of DCs, forcing the generation of immunoprivileged macrophage-like cells instead. Cells derived from M. tuberculosis-infected monocyte-derived macrophages (M. tuberculosis-infected MoMphi) retained CD14 without acquiring CD1 molecules and partially expressed B7.2 but did not up-regulate B7.1 and major histocompatibility complex (MHC) class I and II molecules. They synthesized tumor necrosis factor alpha and interleukin-10 (IL-10) but not IL-12. They also showed a reduced ability to induce proliferation and functional polarization of allogeneic T lymphocytes. Thus, in the presence of IFN-alpha, M. tuberculosis may hamper the renewal of potent APCs, such as DCs, generating a safe habitat for intracellular growth. M. tuberculosis-infected MoMphi, in fact, showed reduced expression of both signal 1 (CD1, MHC classes I and II) and signal 2 (B7.1 and B7.2), which are essential for mycobacterium-specific T-lymphocyte priming and/or activation. These data further suggest that M. tuberculosis has the ability to specifically interfere with monocyte differentiation. This ability may represent an effective M. tuberculosis strategy for eluding immune surveillance and persisting in the host.
The in vitro antibacterial activity of zidovudine alone and in combination with ciprofloxacin was... more The in vitro antibacterial activity of zidovudine alone and in combination with ciprofloxacin was investigated. Zidovudine showed a good activity against Escherichia coli and Salmonella (MIC range 0.5-8 micrograms/ml and 1.5-62 micrograms/ml respectively) isolated from biological samples of HIV-infected patients. These strains proved to be extremely susceptible to ciprofloxacin alone. The interaction between zidovudine and ciprofloxacin ranged from additive activity to indifference. No antagonism was observed: the FIC index for every combination resulted < or = 1.5. The addition of AZT 1 mg/l (clinically achievable plasma concentration after therapeutic doses of 1200 mg/day) did not affect the bactericidal activity of ciprofloxacin; on the contrary, in some cases we observed an increase of bactericidal effect of the quinolone. These data have to be considered in patients with AIDS who can be treated concomitantly with zidovudine and ciprofloxacin.
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