Mycobacterium tuberculosis strains that are resistant to an increasing number of second-line drugs used to treat multidrug-resistant tuberculosis (MDR TB) are becoming a threat to public health worldwide. We surveyed the Network of Supranational Reference Laboratories for M. tuberculosis isolates that were resistant to second-line anti-TB drugs during 2000-2004. We defined extensively drug-resistant TB (XDR TB) as MDR TB with further resistance to >3 of the 6 classes of second-line drugs. Of 23 eligible laboratories, 14 (61%) contributed data on 17,690 isolates, which reflected drug susceptibility results from 48 countries. Of 3,520 (19.9%) MDR TB isolates, 347 (9.9%) met criteria for XDR TB. Further investigation of population-based trends and expanded efforts to prevent drug resistance and effectively treat patients with MDR TB are crucial for protection of public health and control of TB. These drugs are more costly, toxic, and less effective than first-line drugs used for routine treatment of TB (3-6). As with other diseases, resistance to TB drugs results primarily from nonadherence by patients, incorrect drug prescribing by providers, poor quality drugs, or erratic supply of drugs (7).To facilitate treatment of MDR TB in resource-limited countries, where most TB cases occur (1,2), the World Health Organization (WHO) and its partners developed the Green Light Committee, which helps ensure proper use of second-line drugs, to prevent further drug resistance (8). Nonetheless, the Green Light Committee encountered numerous anecdotal reports of MDR TB cases with resistance to most second-line drugs. Once a strain has developed resistance to second-line drugs, these new TB strains are even more difficult to treat with existing drugs. Untreated or inadequately treated patients are at increased risk of spreading their disease in the community, which could lead to outbreaks in vulnerable populations and widespread emergence of a lethal, costly epidemic of drugresistant TB, reminiscent of the MDR TB outbreaks in the early 1990s (9-13). Therefore, to determine whether these anecdotal reports were isolated events, early evidence of an emerging epidemic, or the occurrence of virtually
BackgroundVitamin D (vitD) and L-arginine have important antimycobacterial effects in humans. Adjunctive therapy with these agents has the potential to improve outcomes in active tuberculosis (TB).MethodsIn a 4-arm randomised, double-blind, placebo-controlled factorial trial in adults with smear-positive pulmonary tuberculosis (PTB) in Timika, Indonesia, we tested the effect of oral adjunctive vitD 50,000 IU 4-weekly or matching placebo, and L-arginine 6.0 g daily or matching placebo, for 8 weeks, on proportions of participants with negative 4-week sputum culture, and on an 8-week clinical score (weight, FEV1, cough, sputum, haemoptysis). All participants with available endpoints were included in analyses according to the study arm to which they were originally assigned. Adults with new smear-positive PTB were eligible. The trial was registered at ClinicalTrials.gov NCT00677339.Results200 participants were enrolled, less than the intended sample size: 50 received L-arginine + active vitD, 49 received L-arginine + placebo vit D, 51 received placebo L-arginine + active vitD and 50 received placebo L-arginine + placebo vitD. According to the factorial model, 99 people received arginine, 101 placebo arginine, 101 vitamin D, 99 placebo vitamin D. Results for the primary endpoints were available in 155 (4-week culture) and 167 (clinical score) participants. Sputum culture conversion was achieved by week 4 in 48/76 (63%) participants in the active L-arginine versus 48/79 (61%) in placebo L-arginine arms (risk difference −3%, 95% CI −19 to 13%), and in 44/75 (59%) in the active vitD versus 52/80 (65%) in the placebo vitD arms (risk difference 7%, 95% CI −9 to 22%). The mean clinical outcome score also did not differ between study arms. There were no effects of the interventions on adverse event rates including hypercalcaemia, or other secondary outcomes.ConclusionNeither vitD nor L-arginine supplementation, at the doses administered and with the power attained, affected TB outcomes.Registry ClinicalTrials.gov. Registry number: NCT00677339
Analysis 10.1. Comparison 10 Colloid preload vs colloid coload, Outcome 1 Women with hypotension requiring intervention..... Analysis 10.2. Comparison 10 Colloid preload vs colloid coload, Outcome 2 Women with cardiac dysrhythmia..
The attachment of Cryptosporidium sporozoites to Madin-Darby canine kidney (MDCK) cells was examined using transmission electron microscopy. As the anterior end of the sporozoite came into close proximity to the MDCK cell, the host cell membrane evaginated around the sporozoite, forming a parasitophorous vacuole. A dense band formed below the host cell membrane at the site nearest to the conoid. Variably electron-dense material was apparently released from the conoid and a large membrane-bound vacuole was formed in the anterior end of the sporozoite, displacing the typical anterior electron-dense organelles (rhoptries and micronemes). The outer membrane of the sporozoite pellicle then fused with the host cell membrane immediately adjacent to the conoid. The membrane surrounding the anterior vacuole was also fused with the common host-parasite membrane, forming Y-shaped membrane junctions where each limb was a unit membrane. A direct link was thereby established between the anterior vacuole of the sporozoite and the host cell cytoplasm. The anterior vacuole membrane separating the sporozoite and the host cell cytoplasm was the precursor of the feeder organelle.
Three cases of Mycobacterium avium complex-related lung disorders were associated with two poorly maintained spa pools by genotypic investigations. Inadequate disinfection of the two spas had reduced the load of environmental bacteria to less than 1 CFU/ml but allowed levels of M. avium complex of 4.3 ؋ 10 4 and 4.5 ؋ 10 3 CFU/ml. Persistence of the disease-associated genotype was demonstrated in one spa pool for over 5 months until repeated treatments with greater than 10 mg of chlorine per liter for 1-h intervals eliminated M. avium complex from the spa pool. A fourth case of Mycobacterium avium complex-related lung disease was associated epidemiologically but not genotypically with another spa pool that had had no maintenance undertaken. This spa pool contained low numbers of mycobacteria by smear and was culture positive for M. avium complex, and the nonmycobacterial organism count was 5.2 ؋ 10 6 CFU/ml. Public awareness about the proper maintenance of private (residential) spa pools must be promoted by health departments in partnership with spa pool retailers.Mycobacterium species are ubiquitous in the environment and are found worldwide (7,9,14,21,30). They have a predilection for a variety of natural waters, including lakes, rivers, and streams, and have also been detected in water supply systems (1,6,7,13,14,15,30). In a study of eight water supply distribution systems across the United States, the average number of M. avium in biofilms was 0.3 CFU per cm 2 and the number of M. intracellulare was 600 CFU per cm 2 for all surfaces (13). Mycobacteria not only survive but may persist and increase in number, and waters that have traversed such systems yield mycobacteria. Human beings are regularly exposed to these waters, which represent a potential source for infection.End uses of supplied water are myriad but include industry (machine coolant fluids), hospitals, commercial buildings, residential garden watering, residential drinking and cooking, hot water systems, baths and showers, swimming pools, spa pools or hot tubs, ice machines, aquariums, and miscellaneous purposes such as foot bath whirlpools (1,6,7,12,13,14,26,29,31). Recirculating hot water systems in buildings, spas, and hot tubs have yielded high numbers of M. avium. Indeed, hot water systems may have higher numbers of M. avium than the source water (10). Swimming pools have also yielded M. avium (12), and long-term exposure to aerosols has caused granulomatous pneumonitis in lifeguards (25).A number of reports have demonstrated an association of M. avium complex (MAC) in spa pools with lung disorders in humans (5,11,16,17,18,20). However, most did not study the relationship between clinical and environmental strains except for two studies that used restriction fragment length polymorphism and multilocus enzyme electrophoresis to demonstrate a genotypic link between MAC isolates from the patient and the spa pool (17,20). The present study attempted to define the source, burden, and persistence of MAC in spa pools associated with four cases of l...
Among patients with pulmonary tuberculosis, impaired pulmonary NO bioavailability is associated with more-severe disease and delayed mycobacterial clearance. Measures to increase pulmonary NO warrant investigation as adjunctive tuberculosis treatments.
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