The characterization of Mycobacterium tuberculosis antigens inducing CD4؉ T-cell responses could critically contribute to the development of subunit vaccines for M. tuberculosis. Here we performed computational analysis by using T-cell epitope prediction software (known as TEPITOPE) to predict promiscuous HLA-DR ligands in the products of the mce genes of M. tuberculosis. The analysis of the proliferative responses of CD4 ؉ T cells from patients with pulmonary tuberculosis to selected peptides displaying promiscuous binding to HLA-DR in vitro led us to the identification of a peptide that induced proliferation of CD4؉ cells from 50% of the tested subjects. This study demonstrates that a systematic computational approach can be used to identify T-cell epitopes in proteins expressed by an intracellular pathogen.

Determination of clarithromycin (CL) and azithromycin (AZ) uptake by human polymorphonuclear leukocytes (PMNs), monocytes and alveolar macrophages showed that AZ achieved higher levels than CL. The uptake kinetics of AZ were time-dependent over an 18 h period, while those of CL were similar to erythromycin (ER) kinetics, with a maximum level of incorporation being obtained after a 60 min incubation. The accumulation of both drugs was influenced by extracellular antibiotic-concentrations, PMN viability, extracellular calcium, physiological environmental temperature and pH. The uptake was not modified by inhibitors of cell metabolism or activators of cell membranes. After removal of extracellular antibiotic, the release of AZ from PMNs was very slow: nearly 50% of the drug remained cell-associated after 24 h incubation. The efflux of this derivative was significantly enhanced when drug-loaded PMNs were stimulated by phorbol-myristate acetate (PMA). The kinetics of CL release indicated that this macrolide behaved like ER. Nevertheless, about 10% of the initial cell-associated antibiotic showed a prolonged retention. On the whole, these data suggest that diffusion through cell membranes and trapping into acidic compartments of PMNs are important events in CL and AZ uptake.

Diagnostic tests were only performed in 29% of cases. Chest radiographs were performed most frequently (22%), followed by peripheral blood white cell count (15%) and microbiological examination of sputum (7%), with major differences being found in the frequency of these tests both by clinical diagnosis and country. A change in initial antibiotic therapy was made in 12% of cases, with use of investigation being significantly linked to such changes.Second-and third-line antibiotics were significantly different to first-line therapy, with macrolides the most frequently prescribed second-line and quinolones the most frequently prescribed third-line antibiotics. Eur Respir J., 1996Respir J., , 9, 1596 Lower respiratory tract infections (LRTIs) are amongst the commonest illnesses of mankind, with an estimated annual incidence of 40 per 1,000 adults [1]. Of those seeking medical attention, most are managed in the community by general practitioners (GPs). Antibiotics are the mainstay of therapy, the use of which may be directed by the results of simple investigations. How frequently such investigations are performed in the management of LRTIs in the community, whether there are national differences in the use of such investigations, and the impact of their results on therapy, in particular antibiotic prescription, is not known. A multinational European survey of the management of LRTIs was carried out, and the results regarding the use of investigations and second-and third-line antibiotic therapy are presented here. MethodsThe design of the survey, data collection methods and methods of statistical analysis are detailed in the accompanying paper on first-line antibiotic therapy [2]. Briefly, between December 8, 1993, and January 24, 1994, a standardized questionnaire was administered to a random, but representative sample of GPs in France, Germany, Italy, Spain and the UK, identified by the "method of quotas" [2]. Information was sought about the last three or four adults seen, for whom the GP considered the diagnosis to be community-acquired LRTI. The criteria for this diagnosis were left to the judgement of the GP, since the aim of the study was to investigate normal practice, rather than altering practice by specifying definitions. The time since patient consultation was not recorded, but since the study was performed in the winter the delay between consultation and study is likely to have been short.In addition to questions about patient demographics, symptoms, clinical signs and antibiotic therapy, the questionnaire also sought the GP's presumptive clinical diagnosis. Four clinical categories were provided: community-acquired pneumonia (CAP); acute bronchitis (AB); exacerbation of chronic bronchitis (ECB); and viral LRTI, including influenza (VRTI). Again the criteria for each category were left to the judgement of the GP, but will be analysed as part of a future paper.Details about whether a chest radiograph (CXR), peripheral blood white cell count (WCC) and sputum sample (SPUTUM) had been obtained were recorded...

Cefepime is a novel methoxyimino-aminothiazolyl cephalosporin with a quaternized N-methyl-pyrrolidine moiety at the 3' position conferring zwitterionic properties. Because of this the molecule penetrates the outer cell membrane of Gram-negative bacteria rapidly. In addition it is resistant to degradation by several plasmid and chromosomally-mediated beta-lactamases, for which it also shows very low affinity and no inducing capacity. It has good affinity for PBPs 2 and 3 of Escherichia coli and for PBP 3 of Pseudomonas aeruginosa. Its broad-spectrum of activity includes Gram-positive and Gram-negative pathogens. It is more active than cefotaxime or ceftazidime, against Enterobacteriaceae. The MIC90 for P. aeruginosa is higher than that of ceftazidime, but lower than those of cefpirome, cefoperazone and latamoxef. Other Gram-negative organisms, Haemophilus influenzae, Neiserria meningitidis, Neiserria gonorrhoeae, Moraxella catarrhalis are highly susceptible to cefepime. Among Gram-positive species methicillin-susceptible Staphylococcus aureus and coagulase-negative staphylococci, whether beta-lactamase producers or not, Streptococcus pneumoniae and Streptococcus pyogenes are susceptible. Cefepime is active against cefotaxime- and/or ceftazidime-resistant Enterobacteriaceae. Only strains of P. aeruginosa producing large amounts of beta-lactamase may be resistant to both ceftazidime and cefepime. In experimental infections such as meningitis, induced with various bacterial species in neonatal rats and chronic staphylococcal osteomyelitis in rabbits, cefepime has shown good efficacy.

The direct effect of clarithromycin and azithromycin on human polymorphonuclear leukocyte (PMN) functions and their intracellular activity against Staphylococcus aureus, phagocytosed by human monocytes, were studied. The presence of both antibiotics, in the range of concentrations from 0.25 to 20 micrograms/ml, did not affect chemotaxis, opsonized-zymosan phagocytosis, respiratory burst measured by nitroblue tetrazolium reduction and phorbol myristate acetate-induced superoxide production, or the microbicidal activity of human PMNs against Candida albicans. Both macrolides were bactericidal against staphylococci in the monocyte system, while bacteriostatic activity was found in cell free system. At concentrations equal to the minimum inhibitory concentrations (MICs) (0.75 and 0.1 respectively for azithromycin and clarithromycin) more than 99% of intraphagocytic S. aureus were killed after 24 h incubation. Increasing the concentrations of each drug above the MICs (5 and 10 MICs) did not alter the killing rate of intracellular bacteria. Moreover, no differences between the intracellular bioactivity of these antibiotics were demonstrated, despite their different uptake kinetics.