Aspergillus fumigatus remains a major respiratory pathogen in birds. In poultry, infection by A. fumigatus may induce significant economic losses particularly in turkey production. A. fumigatus develops and sporulates easily in poor quality bedding or contaminated feedstuffs in indoor farm environments. Inadequate ventilation and dusty conditions increase the risk of bird exposure to aerosolized spores. Acute cases are seen in young animals following inhalation of spores, causing high morbidity and mortality. The chronic form affects older birds and looks more sporadic. The respiratory tract is the primary site of A. fumigatus development leading to severe respiratory distress and associated granulomatous airsacculitis and pneumonia. Treatments for infected poultry are nonexistent; therefore, prevention is the only way to protect poultry. Development of avian models of aspergillosis may improve our understanding of its pathogenesis, which remains poorly understood.

BackgroundBacillus anthracis, the highly dangerous zoonotic bacterial pathogen species is currently composed of three genetic groups, called A, B and C. Group A is represented worldwide whereas group B is present essentially in Western Europe and Southern Africa. Only three strains from group C have been reported. This knowledge is derived from the genotyping of more than 2000 strains collected worldwide. Strains from both group A and group B are present in France. Previous investigations showed that the majority of sporadic French strains belong to the so-called A.Br.011/009 group A clade and define a very remarkable polytomy with six branches. Here we explore the significance of this polytomy by comparing the French B. anthracis lineages to worldwide lineages. We take advantage of whole genome sequence data previously determined for 122 French strains and 45 strains of various origins.ResultsA total of 6690 SNPs was identified among the available dataset and used to draw the phylogeny. The phylogeny of the French B group strains which belongs to B.Br.CNEVA indicates an expansion from the south-east part of France (the Alps) towards the south-west (Massif-Central and Pyrenees). The relatively small group A strains belonging to A.Br.001/002 results from at least two independent introductions. Strikingly, the data clearly demonstrates that the currently predominant B. anthracis lineage in North America, called WNA for Western North American, is derived from one branch of the A.Br.011/009 polytomy predominant in France.Conclusions/SignificanceThe present work extends the range of observed substitution rate heterogeneity within B. anthracis, in agreement with its ecology and in contrast with some other pathogens. The population structure of the six branches A.Br.011/009 polytomy identified in France, diversity of branch length, and comparison with the WNA lineage, suggests that WNA is of post-Columbian and west European origin, with France as a likely source. Furthermore, it is tempting to speculate that the polytomy’s most recent common ancestor -MRCA- dates back to the Hundred Years' war between France and England started in the mid-fourteenth century. These events were associated in France with deadly epidemics and major economic and social changes.

Chlamydophila (C.) abortus is the causative agent of ovine enzootic abortion with zoonotic potential whose epidemiology has been held back because of the obligate intracellular habitat of the bacterium. In the present study, we report on a molecular typing method termed multiple loci variable number of tandem repeats (VNTR) Analysis (MLVA) for exploring the diversity of C. abortus. An initial analysis performed with 34 selected genetic loci on 34 ruminant strains including the variant Greek strains LLG and POS resulted in the identification of five polymorphic loci, confirming the widely held notion that C. abortus is a very homogeneous species. Analysis of additional 111 samples with the selected five loci resulted in the classification of all strains into six genotypes with distinct molecular patterns termed genotypes [1] through [6]. Interestingly, the classification of the isolates in the six genotypes was partly related to their geographical origin. Direct examination of clinical samples proved the MLVA to be suitable for direct typing. Analysis of the genomic sequences in six C. abortus prototypes of amplicons generated with each of the five selected VNTR primers revealed that variation between genotypes was caused by the presence or absence of coding tandem repeats in three loci. Amplification of Chlamydophila psittaci reference strains with the five selected VNTR primers and of the six C. abortus prototype strains with the eight VNTR primers established for the typing of C. psittaci [Laroucau, K., Thierry, S., Vorimore, F., Blanco, K., Kaleta, E., Hoop, R., Magnino, S., Vanrompay, D., Sachse, K., Myers, G.S., Bavoil, P.M., Vergnaud, G., Pourcel, C., 2008. High resolution typing of Chlamydophila psittaci by multilocus VNTR analysis (MLVA). Infect. Genet. Evol. 8(2), 171-181] showed that both MLVA typing systems were species-specific when all respective VNTR primer sets were used. In conclusion, the newly developed MLVA system provides a highly sensitive, high-resolution and easy-to-perform tool for the differentiation of C. abortus isolates of different origin, which is suitable for molecular epidemiological studies.

BackgroundAnaplasma phagocytophilum is a tick-borne intragranulocytic alpha-proteobacterium. It is the causative agent of tick-borne fever in ruminants, and of human granulocytic anaplasmosis in humans, two diseases which are becoming increasingly recognized in Europe and the USA. However, while several molecular typing tools have been developed over the last years, few of them are appropriate for in-depth exploration of the epidemiological cycle of this bacterium. Therefore we have developed a Multiple-Locus Variable number tandem repeat (VNTR) Analysis typing technique for A. phagocytophilum.MethodsFive VNTRs were selected based on the HZ human-derived strain genome, and were tested on the Webster human-derived strain and on 123 DNA samples: 67 from cattle, 7 from sheep, 15 from roe deer, 4 from red deer, 1 from a reindeer, 2 from horses, 1 from a dog, and 26 from ticks.ResultsFrom these samples, we obtained 84 different profiles, with a diversity index of 0.96 (0.99 for vertebrate samples, i.e. without tick samples). Our technique confirmed that A. phagocytophilum from roe deer or domestic ruminants belong to two different clusters, while A. phagocytophilum from red deer and domestic ruminants locate within the same cluster, questioning the respective roles of roe vs red deer as reservoir hosts for domestic ruminant strains in Europe. As expected, greater diversity was obtained between rather than within cattle herds.ConclusionsOur technique has great potential to provide detailed information on A. phagocytophilum isolates, improving both epidemiological and phylogenic investigations, thereby helping in the development of relevant prevention and control measures.Electronic supplementary materialThe online version of this article (doi:10.1186/1756-3305-7-439) contains supplementary material, which is available to authorized users.