Shiga toxin-producing Escherichia coli (STEC) cause significant disease; treatment is supportive and antibiotic use is controversial. Ciprofloxacin but not fosfomycin causes Shiga toxin-encoding ...bacteriophage induction and enhanced Shiga toxin (Stx) production from E. coli O157:H7 in vitro. The potential clinical relevance of this was examined in mice colonized with E. coli O157:H7 and given either ciprofloxacin or fosfomycin. Both antibiotics caused a reduction in fecal STEC. However, animals treated with ciprofloxacin had a marked increase in free fecal Stx, associated with death in two-thirds of the mice, whereas fosfomycin did not. Experiments that used a kanamycin-marked Stx2 prophage demonstrated that ciprofloxacin, but not fosfomycin, caused enhanced intraintestinal transfer of Stx2 prophage from one E. coli to another. These observations suggest that treatment of human STEC infection with bacteriophage-inducing antibiotics, such as fluoroquinolones, may have significant adverse clinical consequences and that fluoroquinolone antibiotics may enhance the movement of virulence factors in vivo.
The relationship between nutritional status and the immune system has been a topic of study for much of the 20th century. Dramatic increases in our understanding of the organization of the immune ...system and the factors that regulate immune function have demonstrated a remarkable and close concordance between host nutritional status and immunity. This report traces the increasing sophistication of our understanding of these relationships and their impact on susceptibility to infection through six stages to the present time. The cyclical relationship between poor nutrition, increased susceptibility to infectious diseases, leading to immunological dysfunction and metabolic responses that further alter nutritional status is described and, wherever possible, related to physiological mechanisms. In addition, the particular role of Nevin Scrimshaw in guiding the progress over the past 50 y is discussed. J. Nutr. 133: 336S–340S, 2003.
The protozoan parasite Cryptosporidium parvum is a significant cause of diarrheal disease worldwide. Attachment to and invasion of host intestinal epithelial cells by C. parvum sporozoites are ...crucial steps in the pathogenesis of cryptosporidiosis. The molecular basis of these initial interactions is unknown. In order to identify putative C. parvum adhesion- and invasion-specific proteins, we raised monoclonal antibodies (MAbs) to sporozoites and evaluated them for inhibition of attachment and invasion in vitro. Using this approach, we identified two glycoproteins recognized by 4E9, a MAb which neutralized C. parvum infection and inhibited sporozoite attachment to intestinal epithelial cells in vitro. 4E9 recognized a 40-kDa glycoprotein named gp40 and a second, >220-kDa protein which was identified as GP900, a previously described mucin-like glycoprotein. Glycoproteins recognized by 4E9 are localized to the surface and apical region of invasive stages and are shed in trails from the parasite during gliding motility. The epitope recognized by 4E9 contains alpha-N-acetylgalactosamine residues, which are present in a mucin-type O-glycosidic linkage. Lectins specific for these glycans bind to the surface and apical region of sporozoites and block attachment to host cells. The surface and apical localization of these glycoproteins and the neutralizing effect of the MAb and alpha-N-acetylgalactosamine-specific lectins strongly implicate these proteins and their glycotopes as playing a role in C. parvum-host cell interactions.
There are anecdotal reports in India about the refusal to touch the body of a man dying of AIDS and cutting off the water and power supply to his family to make them leave town, of the wholesale ...abandonment of patients in China, banning infected children from school, detaining and sequestering HIV-infected people in rural towns to prevent their protests. The NIH partner institutes and centers included the Office of the Director (Office of Aids Research, Office of Behavioral and Social Sciences Research, Office of Research on Women's Health), the National Cancer Institute, the National Human Genome Research Institute, the National Institute on Alcohol Abuse and Alcoholism, the National Institute of Allergy and Infectious Diseases, the National Institute of Child Health and Human Development, the National Institute of Dental and Craniofacial Research, National Institute on Drug Abuse, the National Institute of Mental Health, the National Institute of Neurological Disorders and Stroke, and the National Institute of Nursing Research.
Respiratory tract infections are prevalent in elderly individuals, resulting in increased morbidity, mortality, and use of health care services. Vitamin E supplementation has been shown to improve ...immune response in elderly persons. However, the clinical importance of these findings has not been determined.
To determine the effect of 1 year of vitamin E supplementation on respiratory tract infections in elderly nursing home residents.
A randomized, double-blind, placebo-controlled trial was conducted from April 1998 to August 2001 at 33 long-term care facilities in the Boston, Mass, area. A total of 617 persons aged at least 65 years and who met the study's eligibility criteria were enrolled; 451 (73%) completed the study.
Vitamin E (200 IU) or placebo capsule administered daily; all participants received a capsule containing half the recommended daily allowance of essential vitamins and minerals.
Incidence of respiratory tract infections, number of persons and number of days with respiratory tract infections (upper and lower), and number of new antibiotic prescriptions for respiratory tract infections among all participants randomized and those who completed the study.
Vitamin E had no significant effect on incidence or number of days with infection for all, upper, or lower respiratory tract infections. However, fewer participants receiving vitamin E acquired 1 or more respiratory tract infections (60% vs 68%; risk ratio RR, 0.88; 95% confidence interval CI, 0.76-1.00; P =.048 for all participants; and 65% vs 74%; RR, 0.88; 95% CI, 0.75-0.99; P =.04 for completing participants), or upper respiratory tract infections (44% vs 52%; RR, 0.84; 95% CI, 0.69-1.00; P =.05 for all participants; and 50% vs 62%; RR, 0.81; 95% CI, 0.66-0.96; P =.01 for completing participants). When common colds were analyzed in a post hoc subgroup analysis, the vitamin E group had a lower incidence of common cold (0.67 vs 0.81 per person-year; RR, 0.83; 95% CI, 0.68-1.01; P =.06 for all participants; and 0.66 vs 0.83 per person-year; RR, 0.80; 95% CI, 0.64-0.98; P =.04 for completing participants) and fewer participants in the vitamin E group acquired 1 or more colds (40% vs 48%; RR, 0.83; 95% CI, 0.67-1.00; P =.05 for all participants; and 46% vs 57%; RR, 0.80; 95% CI, 0.64-0.96; P =.02 for completing participants). Vitamin E had no significant effect on antibiotic use.
Supplementation with 200 IU per day of vitamin E did not have a statistically significant effect on lower respiratory tract infections in elderly nursing home residents. However, we observed a protective effect of vitamin E supplementation on upper respiratory tract infections, particularly the common cold, that merits further investigation.
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