Infection is the major cause of treatment-related mortality in childhood acute leukemia, mainly due to bacterial translocation across the intestinal mucosa. Only a few studies have reported the ...impact of different antibacterial prophylaxis treatments on digestive tract flora and infection-related mortality.
We performed a retrospective analysis of two different digestive tract decontamination modalities (selective or total digestive decontamination) in a large single-center series of 323 children during the induction treatment of acute leukemia between January 1995 and December 2014. We examined the impact of antibiotic prophylaxis and food regimen (sterile or selected) on the digestive tract flora during the period of antibacterial prophylaxis, on the frequency of bacteremia, and on antibiotic sensitivity.
Only one Gram-negative (Klebsiella pneumonia) translocation occurred in the SDD group. No infection-related death occurred. Extended-spectrum beta-lactamase (ESBL) bacteria were observed in seven of 170 (4%) patients in the SDD group. The faecal-flora total suppression and faecal-flora Gram-negative bacilli suppression was 67 and 77%, respectively, in the TDD group with sterile food, 0 and 58%, respectively, in the SDD group with sterile food, and 6 and 63%, respectively, in the SDD group with selective food.
This study gives a rationale not to use antibacterial prophylaxis systematically in children who receive induction treatment for acute leukemia; additionally, antibiotics should only be used in case of stool contamination by highly pathogenic bacteria with a high potential of translocation.
The incidence of nontuberculous mycobacteria (NTM) pulmonary diseases in HIV-negative patients was studied prospectively from January 1, 2001 to December 31, 2003 by 32 sentinel sites distributed ...throughout France. In total, 262 patients who yielded NTM isolates from respiratory clinical specimens, met the bacteriological, radiological and clinical criteria established by the American Thoracic Society for NTM respiratory disease. Among the 262 NTM isolates, 234 were slow-growing mycobacteria (125 Mycobacterium avium-intracellulare complex (MAC), 66 M. xenopi, 34 M. kansasii) and 28 were rapidly growing mycobacteria (25 M. abscessus complex). In the Paris area, M. xenopi was the most frequently isolated species, followed by MAC. Most patients (>50%), except those with M. kansasii, had underlying predisposing factors such as pre-existing pulmonary disease or immune deficiency. Asthenia, weight loss, chronic cough and dyspnoea were the most common clinical symptoms. The classical radiological appearance of NTM infections was indistinguishable from that observed in patients with pulmonary tuberculosis. In summary, the incidence of nontuberculous mycobacteria pulmonary infections in HIV-negative patients was estimated at 0.74, 0.73 and 0.72 cases per 100,000 inhabitants in 2001, 2002 and 2003, respectively.
Summary
Desulfovibrio are sulfate‐reducing anaerobic gram‐negative rods that have been proposed as potential periodontopathogens. We investigated the capacity of Desulfovibrio to invade epithelial ...cells and induce cytokine secretion from these cells. Desulfovibrio strains were co‐cultured with KB cells and counts of intracellular bacteria evaluated up to 3 days after infection. Desulfovibrio desulfuricans and Desulfovibrio fairfieldensis were able to survive within epithelial cells. Intracytoplasmic location of both bacterial species was confirmed by confocal laser scanning microscopy and transmission electron microscopy. Invasion was sensitive to nocodazole, an inhibitor of microtubule polymerization, but not to cytochalasin D, a microfilament inhibitor, suggesting that microtubule rearrangements were involved in the internalization of Desulfovibrio strains by KB cells. Infection by Desulfovibrio resulted in increased production of IL‐6 and IL‐8 by KB cells. The ability of D. desulfuricans and D. fairfieldensis to survive within oral epithelial cells and to modulate the epithelial immune response may contribute to the initiation and progression of periodontal diseases.
Three strains of anaerobic, non-pigmented, Gram-negative bacilli isolated from various human clinical samples were characterized in terms of phenotypic and genotypic tests, including sequence ...analysis of 16S rRNA and rpoB genes. The strains were most closely related to the type strains of Prevotella marshii and Prevotella shahii on the basis of both 16S rRNA (89.8 and 89.0 % identity, respectively) and rpoB gene sequences (83.1 and 82.8 % identity, respectively). Phylogenetic analysis showed that the isolates constituted a robust homogeneous group distinct from known species in the genus Prevotella. The rrn skeleton (as determined by PFGE) and the DNA G+C content, determined to be 39.4 mol% for strain LBN 293(T), distinguished the novel isolates from the type strains of P. marshii and P. shahii. The three strains were saccharolytic and produced acetic, lactic and succinic acids as major metabolic end products. Polyphasic investigations supported the proposal of a novel species, Prevotella nanceiensis sp. nov., with LBN 293(T) (=AIP 261.03(T) =CIP 108993(T) =CCUG 54409(T)) as the type strain.
Detection of Clostridium difficile toxins A and B in stools by Premier Cytoclone A+B enzyme immunoassay (EIA) was compared with detection by stool culture for C. difficile followed by detection of ...toxigenic isolates using the same EIA. Chart reviews were performed to evaluate the likelihood of C. difficile-associated diarrhea and colitis (CADC) for all patients with at least one positive toxin assay. While the toxins were detected in 58 of 85 consecutive CADC patients by both assays, CADC in 5 patients was detected only by stool toxin assay, and in 22 patients CADC was detected only by toxigenic culture. Our results suggest that for laboratories using a rapid toxin A+B EIA, direct toxin detection in stools should be combined with toxigenic culture in cases in which there is a negative stool toxin assay.
The anti-Helicobacter pylori effect of the extracts and the fractions obtained from Aristolochia paucinervis rhizome and leaves were studied against a reference strain of H. pylori by using the agar ...dilution method. Only the methanol extracts and the hexane fractions of either the rhizome or the leaves exhibited an inhibitory activity at a concentration of < or =128 microg/ml. The leaf hexane fraction APLH demonstrated a higher inhibitory activity (MIC: 4 microg/ml) than the rhizome hexane fraction APRH (MIC: 16 microg/ml), the leaf methanol extract APLM (MIC: 32 microg/ml) and the rhizome methanol extract APRM (MIC: 128 microg/ml). This inhibitory activity was confirmed for the active extracts and fractions against clinical isolates of H. pylori (n = 20) for which MIC50) and MIC90 were determined.
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