24 research outputs found
Bacterial Disease and Antimicrobial Susceptibility Patterns in HIV-Infected, Hospitalized Children: A Retrospective Cohort Study
The orginal version is available at www.plosone.orgBackground: Serious bacterial infections are a major source of morbidity and mortality in HIV-infected children. The
spectrum of disease is wide, and responsible organisms vary according to setting. The use of antibiotic prophylaxis and the
emergence of multi-drug resistant bacteria necessitate examination of responsible organisms and their antibiotic
susceptibility.
Methodology/Principal Findings: A retrospective cohort study of all HIV-positive pediatric admissions at an urban public
sector hospital in Cape Town between January 2002 and June 2006 was conducted. Children between the ages of one
month and nine years with laboratory confirmed HIV status, serious bacterial infection, and a hospital length of stay of 5
days or more, were eligible for inclusion. Organisms isolated from blood, urine, and cerebral spinal fluid cultures and their
antimicrobial susceptibility were examined, and compared according to timing of isolation to distinguish nosocomial versus
community-acquired. One hundred and forty-one children were identified (median age 1.2 years), 39% of whom were on
antiretrovirals started before or during this hospitalization. Bacterial infections involved all organ systems, however
pneumonia was most common (67%). S. pneumoniae and S. aureus were the most common gram positive and K.
pneumoniae was the most common gram negative organism. K pneumoniae isolates were resistant to many first and second
line antibiotics, and were all considered nosocomial. All S. aureus isolates were methicillin resistant, some of which were
community-acquired.
Conclusions/Significance: Bacterial infections are an important source of co-morbidity in HIV-infected children in resourcelimited
settings. Clinicians should have a low threshold to initiate antibiotics in children requiring hospitalization. Broadspectrum
antibiotics should be used judiciously. Clinicians caring for HIV-infected children should be cognizant of the most
common organisms affecting such children, and of their local antimicrobial susceptibilities, when treating empirically for
serious bacterial infections.Publisher's versio
Autoantibodies to αS1-Casein Are Induced by Breast-Feeding
BACKGROUND: The generation of antibodies is impaired in newborns due to an immature immune system and reduced exposure to pathogens due to maternally derived antibodies and placental functions. During nursing, the immune system of newborns is challenged with multiple milk-derived proteins. Amongst them, caseins are the main constituent. In particular, human αS1-casein (CSN1S1) was recently shown to possess immunomodulatory properties. We were thus interested to determine if auto-antibodies to CSN1S1 are induced by breast-feeding and may be sustained into adulthood. METHODS: 62 sera of healthy adult individuals who were (n = 37) or were not (n = 25) breast-fed against human CSN1S1 were investigated by a new SD (surface display)-ELISA. For cross-checking, these sera were tested for anti Epstein-Barr virus (EBV) antibodies by a commercial ELISA. RESULTS: IgG-antibodies were predominantly detected in individuals who had been nursed. At a cut-off value of 0.4, the SD-ELISA identified individuals with a history of having been breast-fed with a sensitivity of 80% and a specificity of 92%. Under these conditions, 35 out of 37 sera from healthy donors, who where breast-fed, reacted positively but only 5 sera of the 25 donors who were not breast-fed. The duration of breast-feeding was of no consequence to the antibody reaction as some healthy donors were only short term breast-fed (5 days minimum until 6 weeks maximum), but exhibited significant serum reaction against human CSN1S1 nonetheless. CONCLUSION: We postulate that human CSN1S1 is an autoantigen. The antigenicity is orally determined, caused by breast-feeding, and sustained into adulthood