Migration patterns among global populations of the pathogenic fungus Mycosphaerella graminicola.

DNA sequences from five nuclear loci and data from three microsatellites were collected from 360 isolates representing 14 globally distributed populations of the plant pathogenic fungus Mycosphaerella graminicola. Haplotype networks were constructed for the five sequence loci and population subdivision was assessed using Hudson's permutation test. Migration estimates were calculated using six regional populations for both the sequence and microsatellite loci. While subdivision was detected among the six regional populations, significant gene flow was indicated among some of the populations. The European and Israeli populations contributed the majority of historical immigrants to the New World. Migration estimates for microsatellite loci were used to infer more recent migration events among specific New World populations. We conclude that gene flow was an important factor in determining the demographic history of Mycosphaerella graminicola.

Phylogenetic analysis of globally distributed Mycosphaerella graminicola populations based on three DNA sequence loci.

DNA sequence data from three nuclear loci were collected from 384 isolates representing fourteen globally distributed populations of the plant pathogenic fungus Mycosphaerella graminicola. Gene genealogies were constructed for the actin and beta-tubulin loci as well as for the previously characterized RFLP locus STS2. The STS2 and beta-tubulin loci showed greater potential for phylogenetic studies than the actin locus. Greater sequence diversity was found in the "Old World" populations (Middle East and Europe) than in the "New World" populations (North and South America and Australia). The gene trees were rooted using homologous DNA sequences of Septoria passerinii, the closest known relative to M. graminicola, as well as coalescent rooting. Based on the rooted trees, a tentative phylogenetic history of these populations was inferred. The Middle East appears to be the most likely center of origin, while European populations are more ancient than New World populations. A test for neutrality indicated that the intron in the actin locus could be under selection, while the other two sequence loci were neutral.

Fewer bacterial relapses after oral treatment with norfloxacin than with ceftibuten in acute pyelonephritis initially treated with intravenous cefuroxime.

This double-blind, multicentre study was performed at nine centres on a total of 171 patients who presented with fever (> 38.5 degrees C) and signs of acute pyelonephritis. All were initially treated with intravenous cefuroxime. After 2-3 d, when the fever had subsided and urinary culture had revealed growth of Gram-negative bacteria ( > 10(7) colony-forming units per litre), treatment was changed to oral administration of ceftibuten 200 mg b.i.d. or norfloxacin 400 mg b.i.d. for 10 d. The patients were followed for signs of bacterial or clinical relapse 7-14 d after the end of treatment. The initial clinical and bacteriological cure was excellent in both groups, but there were significantly fewer bacterial relapses after oral treatment with norfloxacin than with ceftibuten in acute febrile pyelonephritis initially treated with intravenous cefuroxime. The causal strain was eradicated in 75% of patients (73% of males, 76% of females) in the ceftibuten group and in 89% of patients (94% of males, 85% of females) in the norfloxacin group. The relative frequency of eradication was 0.84 (p < 0.05; 95%, confidence interval 0.74-0.97). Adverse events were reported by 47% of the patients in the ceftibuten group and by 38% in the norfloxacin group. This difference was not significant, but diarrhoea or loose stools occurred more frequently in the ceftibuten group.

Ampicillin plus mecillinam vs. cefotaxime/cefadroxil treatment of patients with severe pneumonia or pyelonephritis: a double-blind multicentre study evaluated by intention-to-treat analysis.

In this double-blind multicentre study, using the intention-to-treat approach, a total of 293 patients with fever (> or = 38.5 degrees C), symptoms of sepsis and signs of pneumonia or pyelonephritis were randomly assigned to treatment with ampicillin and mecillinam (A+M) or cefotaxime followed by cefadroxil. In the febrile phase, treatment was given intravenously twice daily, either with 1,200 mg ampicillin together with 600 mg mecillinam or with 2 g cefotaxime alone. When the patients stayed afebrile, the intravenous administration was replaced by oral treatment twice daily for 14 days, either with 500 mg pivampicillin and 400 mg pivmecillinam or 1 g cefadroxil. In the A+M group, 33% (48/144) of the patients did not complete the full course of treatment as compared with 32% (47/149) in the cephalosporin group, the reasons being treatment failure in 27 and 29, respectively, or adverse effects (n = 16 in both groups). The median duration of fever was 47 h in the A + M group and 50 h in the cephalosporin group. Of 135 patients with pneumonia, 68% were completely cured in the A + M group, and 65% in the cephalosporin group, the main reasons for treatment failure being Mycoplasma pneumonia or ornithosis. Of 136 patients with pyelonephritis, 63% were cured in each group. The main reason for failure was bacteriological relapse. Side-effects were reported by 32 patients (22%) of the A+M group, as compared with 41 (28%) of the cephalosporin group. Epigastric complaints were equally frequent in both groups, but there was a tendency for a higher frequency of exanthema in the A+M group, and for antibiotic-associated diarrhoea and fungal superinfections in the cephalosporin group.