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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Amphotericin B and fluconazole are current acceptable therapies for cryptococcal meningitis; however, their effect remains suboptimal. The combination of fluconazole and flucytosine has yielded encouraging clinical results in human immunodeficiency virus patients with cryptococcal meningitis. To investigate the biological basis of this finding, we performed in vitro combination testing of fluconazole and flucytosine against 50 clinical strains of Cryptococcus neoformans var. neoformans. Synergy (fractional inhibitory concentration index of < 1.0) was observed in 62% of cases, while antagonism (fractional inhibitory concentration index of > 2.0) was not observed. For cases in which synergy was not achieved (autonomous or additive effects), the beneficial effect of the combination was still seen (i.e., there was still a decrease, although not as dramatic, in the MIC of one or both drugs when used in combination). The in vitro inhibitory action of flucytosine was greatly enhanced by the addition of fluconazole; the flucytosine MICs for Cryptococcus isolates were markedly decreased to concentrations which were severalfold lower than the achievable cerebrospinal fluid flucytosine concentration. On the other hand, the addition of flucytosine did not greatly enhance the in vitro activity of fluconazole if the initial fluconazole MIC for the isolate was > or = 8 micrograms/ml. Controlled clinical studies are warranted to further elucidate the potential utility of fluconazole-flucytosine combination therapy.
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PMID:In vitro evaluation of combination of fluconazole and flucytosine against Cryptococcus neoformans var. neoformans. 748 2

After repeated use of fluconazole for therapy of oropharyngeal candidosis, the emergence of in vitro fluconazole-resistant Candida albicans isolates (MIC, > or = 25 micrograms/ml) together with oral candidosis unresponsive to oral dosages of up to 400 mg of fluconazole were observed in patients with human immunodeficiency virus (HIV) infection. Antifungal susceptibility testing was done by broth microdilution and agar dilution techniques on C. albicans isolates recovered from a cohort of patients with symptomatic HIV infection who were treated repeatedly with fluconazole for oropharyngeal candidosis. In vitro findings did show a gradual increase in the MICs for C. albicans isolates recovered from selected patients with repeated episodes of oropharyngeal candidosis. Primary resistance of C. albicans to fluconazole was not seen. Cross-resistance in vitro occurred between fluconazole and other azoles (ketoconazole, itraconazole), but to a lesser extent. The results of the study suggest that the development of clinical resistance to fluconazole could be clearly correlated to in vitro resistance to fluconazole. Itraconazole may still serve as an effective antifungal agent in patients with HIV infection and oropharyngeal candidosis nonresponsive to fluconazole.
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PMID:Emergence of fluconazole-resistant strains of Candida albicans in patients with recurrent oropharyngeal candidosis and human immunodeficiency virus infection. 781 30

A broth macrodilution technique, which was performed by following the recommendations provided by the National Committee for Clinical Laboratory Standards (document M27-P), was applied to study the in vitro activity of itraconazole against fluconazole-susceptible and -resistant Candida albicans isolates from the oral cavities of 100 patients infected with human immunodeficiency virus. The in vitro data demonstrated that itraconazole had good activity against the tested isolates; for 90% of all strains of C. albicans, MICs were 1 microgram/ml, and only one isolate was highly resistant to this triazole (MIC, > 16 micrograms/ml). However, the itraconazole MICs for the fluconazole-susceptible isolates were significantly lower than those for the fluconazole-resistant isolates; the MICs for 50 and 90% of the isolates tested were < or = 0.03 and 0.25 microgram/ml, respectively, for the fluconazole-susceptible isolates and 0.5 and 1 microgram/ml, respectively, for the fluconazole-resistant isolates (P = 0.00001). Our findings could be of clinical relevance because human immunodeficiency virus-infected patients who fail fluconazole therapy for oral and/or esophageal candidiasis may require itraconazole at doses higher than those used in standard therapy.
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PMID:In vitro activity of itraconazole against fluconazole-susceptible and -resistant Candida albicans isolates from oral cavities of patients infected with human immunodeficiency virus. 797 84

Thirty human immunodeficiency virus-positive patients carrying Candida albicans in their oropharynx were treated with fluconazole and were monitored for 90 to 570 days. Fluconazole-resistant C. albicans (MIC, > 32 micrograms/ml) appeared only in seven patients and only after 90 days of treatment corresponding to a total dose of more than 10 g. Resistance was not associated with resistance to other azole derivatives. Susceptible and resistant strains from each patient had the same genotype (as defined by electrophoretic karyotype and restriction fragment length polymorphism). Thus, the resistant strains were selected by the antimycotic treatment from the susceptible strain present in each case.
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PMID:Fluconazole-resistant recurrent oral candidiasis in human immunodeficiency virus-positive patients: persistence of Candida albicans strains with the same genotype. 802 27

Preliminary studies showed that roxithromycin possessed significant in vitro activity against a variety of atypical mycobacteria such as the Mycobacterium avium complex, M. scrofulaceum, M. szulgai, M. malmoense, M. xenopi, M. marinum, and M. kansasii and rare pathogens such as M. chelonae and M. fortuitum. In this investigation, radiometric MICs of roxithromycin, ethambutol, rifampin, amikacin, ofloxacin, and clofazimine for 10 clinical isolates of the M. avium complex (5 each from human immunodeficiency virus [HIV]-positive and HIV-negative patients) were determined. Roxithromycin MICs against all the isolates were below the reported maximum concentration of drug in serum at the routine pH of 6.8, and the MICs were further lowered by 1 to 2 dilutions at a pH of 7.4. In vitro enhancement of roxithromycin activity against all strains was further investigated by the previously established Bactec 460-TB method by combining the drugs at sub-MIC levels. Antibacterial activity of roxithromycin was enhanced in all 10 strains by ethambutol, in 3 strains each by rifampin and clofazimine, in 2 strains by amikacin, and in 1 strain by ofloxacin. In vitro screening of three-drug combinations showed that combinations of roxithromycin, ethambutol, and a third potential anti-M. avium drug (rifampin, amikacin, ofloxacin, or clofazimine) resulted in further enhancement of activity in 13 out of 20 drug combinations screened.
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PMID:Activities of roxithromycin used alone and in combination with ethambutol, rifampin, amikacin, ofloxacin, and clofazimine against Mycobacterium avium complex. 809 50

Zidovudine (ZDV) has antibacterial activity against many members of the family Enterobacteriaceae, including Salmonella species, and may be responsible for a decrease in the frequency of salmonellosis in persons infected with human immunodeficiency virus (HIV). Other nucleoside analogs, such as didanosine (2',3'-dideoxyinosine [ddI]) and zalcitabine (2',3'-dideoxycytidine [ddC]), which have undefined anti-salmonella activity, increasingly are being used in the treatment of HIV infection. To evaluate the anti-Salmonella activity of the antiviral agents ZDV, ddI, ddC, and acyclovir (ACV), we determined MICs for 39 nontyphoidal Salmonella blood isolates. ZDV (MIC for 50% of strains tested [MIC50], 0.5 microgram/ml; MIC range, 0.125 to 4 micrograms/ml) and ddI (MIC50, 8 micrograms/ml; MIC range, 2 to 125 micrograms/ml) had concentration-dependent activity. Anti-Salmonella activity was not observed for ddC or ACV. Nine Escherichia coli blood isolates were inhibited by ZDV (MIC50, 0.125 microgram/ml; MIC range, 0.031 to 1 microgram/ml) to a greater degree than they were by ddI (MIC50, 62.5 micrograms/ml; MIC range, 31 to > 62.5 micrograms/ml). Inoculum size affected susceptibility to ZDV and ddI for Salmonella and E. coli isolates. Resistance to ZDV or to ddI could be induced in vitro in Salmonella isolates, but cross-resistance was not observed. These results indicate that at concentrations achieved during the treatment of HIV infection, ZDV has activity against nontyphoidal salmonellae, although resistance can develop. ddI, ddC, and ACV at currently used dosages would not be expected to be effective in the prevention or treatment of Salmonella infections.
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PMID:In vitro activities of nucleoside analog antiviral agents against salmonellae. 843 Oct 5

The 5-aryl-4-methyl-2-(4-pyridyl)-delta 2-1,3,4-oxadiazolines 3, previously synthesized along with isomer 4-aryl-1-methoxy-1-(4-pyridyl)-2,3-diaza-1,3-butadienes 2 from benzaldehyde isonicotinoylhydrazones and diazomethane, were tested for in vitro activity against both M. tuberculosis and some atypical mycobacterial strains as well as against human immunodeficiency virus (HIV-1). Some halophenyl derivatives, 3e, 3g, 3i, 3j, were found to display MIC ranges from 1 to 10 (micrograms/ml against H 37 Rv and a clinical isolate tubercular strain, whereas against M. avium (MAC) the MICs were higher than 20 micrograms/ml. When the combinations of oxadiazolines with ethambutol, acting as inhibitor of cell wall synthesis, were assayed on MAC strain a synergistic effect was demonstrated for 3g and 3h trifluoromethyl derivatives. The antimycobacterial profiles of 2 and 3 analogues are compared and discussed. As shown by compounds 2, no substantial anti-HIV in vitro activity was found in selected delta 2-oxadiazolines; a moderate cytotoxicity, however, appears to be a common property.
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PMID:2-(4-Pyridyl)-delta 2-1,3,4-oxadiazolines from isonicotinoylhydrazones and diazomethane as potential antimycobacterial and anti-HIV agents. V. 859 76

A 33-year-old, active intravenous drug-abusing male infected with the human immunodeficiency virus developed endocarditis due to Arcanobacterium haemolyticum. Empirical treatment with ampicillin plus gentamicin failed to achieve a marked clinical improvement. When the results of antibiotic susceptibility were available (ampicillin MIC < or = 0.06 mg/l; ampicillin MBC 2 mg/l; MBC:MIC ratio > 32) therapy was changed to vancomycin plus gentamicin. During the following days progressive clinical and radiological improvement was observed. The patient received antibiotics for 30 days and no relapse occurred during a 14-month follow-up. The literature of endocarditis due to this uncommon bacterium is reviewed here.
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PMID:Endocarditis caused by Arcanobacterium haemolyticum. 868 85

Serial isolates of Cryptococcus neoformans from 33 human immunodeficiency virus-infected patients with cryptococcosis were analyzed to determine whether persistence might result from reinfection with a new cryptococcal strain or acquisition of antifungal resistance. Isolates were subtyped by multilocus enzyme electrophoresis (MEE), electrophoretic karyotyping (EK), random-amplified polymorphic DNA (RAPD), and the CNRE-1 DNA probe, MICs of amphotericin B, fluconazole, and 5-fluorocytosine were determined. No changes in MEE or RAPD subtypes were detected in serial isolates from any patient. Isolates from 8 patients (24%) showed alterations in EK only (mobility change in two or more bands) but not with any other subtyping method. MICs did not change significantly in isolates from 30 patients. In 1 case, the fluconazole MIC increased stepwise over 18 months, suggesting development of resistance. These overall invariant subtyping and MIC results confirm previous studies suggesting that persistent cryptococcal infection is due to relapse rather than reinfection or antifungal drug resistance.
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PMID:Molecular subtypes and antifungal susceptibilities of serial Cryptococcus neoformans isolates in human immunodeficiency virus-associated Cryptococcosis. Cryptococcal Disease Active Surveillance Group. 884 21

The MICs of fluconazole for strains of Candida species and the levels of fluconazole in serum were determined at day 0 and day 14 for 23 human immunodeficiency virus-infected patients with oral candidiasis who were treated orally with 100 mg of fluconazole per day for 14 days. Among the 23 patients, 11 (48%) were not clinically cured and had persistent isolation of Candidiasis albicans (n = 10) and/or presence of non-C. albicans (n = 6). Clinical response could be predicted by the susceptibility of the strain to fluconazole determined at day 0. All 12 patients who were cured were infected with a strain for which the MIC was < 0.78 mg/liter. All four patients who were infected with a strain for which the MIC was > 3.12 mg/liter experienced clinical failure. These data suggest that a C. albicans strain could be defined as being susceptible when the MIC of fluconazole is < 0.78 mg/liter and as being resistant when the MIC is > 3.12 mg/liter.
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PMID:Response to fluconazole by 23 patients with human immunodeficiency virus infection and oral candidiasis: pharmacological and mycological factors. 884 16


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