Cerebral fungal infection with mycotic aneurysm of basilar artery and subarachnoid haemorrhage

A 28-year-old Pakistani man was admitted with unresolved severe headaches for the past four weeks. Magnetic resonance (MR) imaging and MR angiography showed an enhancing mass in the sphenoid sinus, bilateral cerebellar infarcts and aneurysmal dilatation of the basilar artery. The differential diagnosis included fungal infection versus neoplastic lesion. The scrappings taken through the endoscope from the sphenoid sinus were initially negative for fungal infection. However, the second biopsy, done after putting him on antifungal, itraconazole 200 mg twice daily, revealed the presence of a fungal infection (aspergillosis). MR imaging revealed extension of the fungal infection from the sphenoid sinus into the clivus, and then intracranially. Imaging also revealed aneurysmal dilatation of the basilar artery and infarctions in the cerebellum and subarachnoid haemorrhage. Despite aggressive antifungal treatment, the Patient died after 29 days. This case report describes the probable mechanism of fungal mycotic aneurysmal vascular dilatation and growth. It also points to the need for a rapid diagnosis of potential cases and an aggressive treatment approach of confirmed cases of fungal infections of the central nervous system

Using European travellers as an early alert to detect emerging pathogens in countries with limited laboratory resources

BACKGROUND: The volume, extent and speed of travel have dramatically increased in the past decades, providing the potential for an infectious disease to spread through the transportation network. By collecting information on the suspected place of infection, existing surveillance systems in industrialized countries may provide timely information for areas of the world without adequate surveillance currently in place. We present the results of a case study using reported cases of Shigella dysenteriae serotype 1 (Sd1) in European travellers to detect "events" of Sd1, related to either epidemic cases or endemic cases in developing countries. METHODS: We identified papers from a Medline search for reported events of Sd1 from 1940 to 2002. We requested data on shigella infections reported to the responsible surveillance entities in 17 European countries. Reports of Sd1 from the published literature were then compared with Sd1 notified cases among European travellers from 1990 to 2002. RESULTS: Prior to a large epidemic in 1999–2000, no cases of Sd1 had been identified in West Africa. However, if travellers had been used as an early warning, Sd1 could have been identified in this region as earlier as 1992. CONCLUSION: This project demonstrates that tracking diseases in European travellers could be used to detect emerging disease in developing countries. This approach should be further tested with a view to the continuous improvement of national health surveillance systems and existing European networks, and may play a significant role in aiding the international public health community to improve infectious disease control

Serogroup prevalence of Shigellae in Bombay.

Prevalence of Shigellae serotypes in Bombay was studied from June 1988 to May 1991. A total of 2758 faecal specimens were collected from paediatric patients (< 12 yrs) with acute gastroenteritis. A total of 90 Shigella were isolated giving the isolation rate of 3.2%. Shigella flexneri was the predominant serogroup (73.3%) followed by Shigella dysenteriae (16.6%). All the isolates were sensitive to nalidixic acid. Eighty percent of the Shigellae were multidrug resistant. Present data were compared with the study carried out during the period of 1983-87 from the same institute. A change in the serogroup prevalence was noted wherein Shigella flexneri dominated over Shigella dysenteriae since 1985. Increase in resistance to ampicillin and cotrimoxazole was seen in Shigella flexneri strains as compared to previous years

AXR2 Encodes a Member of the Aux/IAA Protein Family

The dominant gain-of-function axr2-1 mutation of Arabidopsis causes agravitropic root and shoot growth, a short hypocotyl and stem, and auxin-resistant root growth. We have cloned the AXR2 gene using a map-based approach, and find that it is the same as IAA7, a member of the IAA (indole-3-acetic acid) family of auxin-inducible genes. The axr2-1 mutation changes a single amino acid in conserved domain II of AXR2/IAA7. We isolated loss-of-function mutations in AXR2/IAA7 as intragenic suppressors of axr2-1 or in a screen for insertion mutations in IAA genes. A null mutant has a slightly longer hypocotyl than wild-type plants, indicating that AXR2/IAA7 controls development in light-grown seedlings, perhaps in concert with other gene products. Dark-grown axr2-1 mutant plants have short hypocotyls and make leaves, suggesting that activation of AXR2/IAA7 is sufficient to induce morphological responses normally elicited by light. Previously described semidominant mutations in two other Arabidopsis IAA genes cause some of the same phenotypes as axr2-1, but also cause distinct phenotypes. These results illustrate functional differences among members of the Arabidopsis IAA gene family

The genome and lifestage-specific transcriptomes of a plant-parasitic nematode and its host reveal susceptibility genes involved in trans-kingdom synthesis of vitamin B5

Plant-parasitic nematodes are a major threat to crop production in all agricultural systems. The scarcity of classical resistance genes highlights a pressing need to find new ways to develop nematode-resistant germplasm. Here, we sequence and assemble a high-quality phased genome of the model cyst nematode Heterodera schachtii to provide a platform for the first system-wide dual analysis of host and parasite gene expression over time, covering all major parasitism stages. Analysis of the hologenome of the plant-nematode infection site identified metabolic pathways that were incomplete in the parasite but complemented by the host. Using a combination of bioinformatic, genetic, and biochemical approaches, we show that a highly atypical completion of vitamin B5 biosynthesis by the parasitic animal, putatively enabled by a horizontal gene transfer from a bacterium, is required for full pathogenicity. Knockout of either plant-encoded or now nematode-encoded steps in the pathway significantly reduces parasitic success. Our experiments establish a reference for cyst nematodes, further our understanding of the evolution of plant-parasitism by nematodes, and show that congruent differential expression of metabolic pathways in the infection hologenome represents a new way to find nematode susceptibility genes. The approach identifies genome-editing-amenable targets for future development of nematode-resistant crops

The genome and lifestage-specific transcriptomes of a plant-parasitic nematode and its host reveal susceptibility genes involved in trans-kingdom synthesis of vitamin B5.

Plant-parasitic nematodes are a major threat to crop production in all agricultural systems. The scarcity of classical resistance genes highlights a pressing need to find new ways to develop nematode-resistant germplasm. Here, we sequence and assemble a high-quality phased genome of the model cyst nematode Heterodera schachtii to provide a platform for the first system-wide dual analysis of host and parasite gene expression over time, covering all major parasitism stages. Analysis of the hologenome of the plant-nematode infection site identified metabolic pathways that were incomplete in the parasite but complemented by the host. Using a combination of bioinformatic, genetic, and biochemical approaches, we show that a highly atypical completion of vitamin B5 biosynthesis by the parasitic animal, putatively enabled by a horizontal gene transfer from a bacterium, is required for full pathogenicity. Knockout of either plant-encoded or now nematode-encoded steps in the pathway significantly reduces parasitic success. Our experiments establish a reference for cyst nematodes, further our understanding of the evolution of plant-parasitism by nematodes, and show that congruent differential expression of metabolic pathways in the infection hologenome represents a new way to find nematode susceptibility genes. The approach identifies genome-editing-amenable targets for future development of nematode-resistant crops