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Biomedical subjects

William Bishai

Publications and source records attributed to William Bishai.

6 recordsLinked to original sources
PubMed2004

Risk factors for relapse and acquired rifamycin resistance after directly observed tuberculosis treatment: a comparison by HIV serostatus and rifamycin use.

We sought to determine the risk of acquired rifamycin resistant (ARR) tuberculosis associated with rifampin- versus rifabutin-based directly observed therapy and to assess the risk factors for relapse of tuberculosis. This observational cohort study included patients with culture-confirmed rifamycin-susceptible tuberculosis reported to the Baltimore City Health Department (Baltimore, MD) during the period of January 1993 through December 2001. Of the 407 patients, 108 (27%) were human immunodeficiency virus (HIV) seropositive, 161 (40%) were HIV seronegative, and 138 (34%) had an unknown serostatus. Three (2.8%) of 108 HIV-seropositive persons had ARR tuberculosis, compared with 0 of 299 persons with negative or unknown HIV serostatus (P=.02). Among HIV-seropositive patients, 3 (3.7%) of 81 who were treated with rifampin and 0 of 27 who were treated with rifabutin had ARR tuberculosis (P=.57). Among HIV-seropositive patients, the only risk factor for recurrent tuberculosis was a low median initial CD4+ T lymphocyte count (51 vs. 138 cells/mm3; P=.02). The median CD4+ T lymphocyte count among patients with ARR tuberculosis was 51 cells/mm3. ARR tuberculosis can occur with rifampin-based regimens, but in this study, the risk was not significantly higher than that for a rifabutin-based regimen.

Adult↗
PubMed2004

A review of clinical failures associated with macrolide-resistant Streptococcus pneumoniae.

The emerging reports of clinical failures using macrolides and their associations with macrolide-resistant Streptococcus pneumoniae prompted us to review the literature describing these cases. Thirty-three cases reporting macrolide treatment failure during treatment of pneumococcal infections were available for review. The most prevalent diagnosis (24/27 or 88.8% of available diagnoses) was community-acquired pneumonia (CAP). Previous medical history included cardiopulmonary disease in eight (24.2%) and immunocompromised states in five (15.1%) patients. The majority, 31/33 (93.9%) of patients received oral macrolide treatment in an outpatient setting. S. pneumoniae was isolated from the blood in 26 (78.8%) of 33 patients, three (9.1%) patients had bacteria present in both blood and cerebrospinal fluid, two (6%) patients grew S. pneumoniae from blood and bronchial washings and two (6%) patients had positive sputum cultures. The MLS(B) phenotype was the most predominant phenotype present in 12 (63.2%) of 19 patients. After failing initial macrolide treatment, 26 (78.8%) of 33 patients received parenteral antibiotic treatment. Of 33 patients admitted to hospital, 29 (87.8%) had their outcome described as 'survived'.

Adolescent↗
PubMed2002

Current issues on resistance, treatment guidelines, and the appropriate use of fluoroquinolones for respiratory tract infections.

BACKGROUND: Community-acquired respiratory tract infections comprise a large percentage of diseases treated by primary care physicians, and rates of antimicrobial use for respiratory tract infections are increasing. The fluoroquinolones comprise a drug class with broad-spectrum activity against many of the key pathogens associated with community-acquired respiratory tract infections, including Streptococcus pneumoniae, and other significant pathogens, such as Staphylococcus aureus and Pseudomonas aeruginosa. While fluoroquinolones have gained popularity, the settings for their appropriate use in treating respiratory tract infections remain unclear. OBJECTIVE: In this article, the mechanisms of fluoroquinolone resistance in S. pneumoniae, treatment guidelines, and the mode of spread of resistance are reviewed. METHODS: The authors conducted a MEDLINE search for articles published from 1990 to the present. Search terms included Streptococcus pneumoniae, fluoroquinolones, and resistance. Articles were selected for inclusion based on their relevance to the objective of this review. RESULTS: Although 3 sets of treatment guidelines for community-acquired pneumonia (CAP) currently exist in the United States, a consensus for the role of fluoroquinolones in the outpatient management of CAP has not been achieved. Factors mitigating for restraint in the outpatient use of fluoroquinolones include concern for the spread of resistance to "innocent-bystander" organisms, such as S. aureus and P. aeruginosa, as well as possible inappropriate "trickle-down" use for other, less severe respiratory syndromes, such as bronchitis. CONCLUSION: Although the fluoroquinolones are potent agents against respiratory pathogens and have a clearly defined role in the treatment of hospitalized patients with CAP, their optimal role in the outpatient management of respiratory tract infections remains controversial.

Anti-Infective Agents↗
PubMed2002

Bactericidal activity of increasing daily and weekly doses of moxifloxacin in murine tuberculosis.

Moxifloxacin (MXF) is a new 8-methoxyquinolone with potent activity against Mycobacterium tuberculosis and a half-life of 9 to 12 h in humans. Previous in vivo studies using daily doses of 100 mg/kg of body weight have demonstrated bactericidal activity comparable to that of isoniazid (INH) in a murine model of tuberculosis (TB). Recent pharmacokinetic data suggest that MXF may have been underadministered in these studies and that a 400-mg/kg dose in mice better approximates the area under the concentration-time curve obtained in humans after a 400-mg oral dose. Therefore, the bactericidal activity of MXF in doses up to 400 mg/kg given daily or weekly for 28 days was assessed in mice infected intravenously with 5 x 10(6) CFU of M. tuberculosis. INH was used as a positive control. After 3 days of daily therapy, the CFU counts from splenic homogenates for mice treated with MXF in doses of 100 to 400 mg/kg/day were lower than those from pretreatment controls. No significant differences in CFU counts were seen when mice receiving INH or MXF at 50 mg/kg/day were compared to pretreatment controls. After 28 days of therapy, dose-dependent reductions in CFU counts in splenic homogenates were seen for daily MXF therapy. The maximum bactericidal effect was seen with daily doses of 400 mg/kg, which resulted in a reduction in CFU counts of 1 log(10) greater than that with INH treatment, although the difference was not statistically significant. CFU counts from lung homogenates after 28 days of therapy were significantly lower in all treatment groups than in untreated controls. The weekly administration of MXF in doses ranging from 50 to 400 mg/kg resulted in no significant bactericidal activity. Mice receiving daily MXF doses of 200 and 400 mg/kg/day failed to gain weight and appeared ill after 28 days of therapy, findings suggestive of drug toxicity. In conclusion, MXF has dose-dependent bactericidal activity against M. tuberculosis in the mouse when given in doses up to 400 mg/kg, where its pharmacokinetic profile better approximates that of standard human dosages. Combination regimens which take advantage of the enhanced pharmacodynamic profile of MXF at these doses have the potential to shorten the course of antituberculous therapy or allow more intermittent (i.e., once-weekly) therapy and should be evaluated in the mouse model of TB.

Animals↗