Genome Sequences of Three hpAfrica2 Strains of Helicobacter pylori.

We present the genome sequences of three hpAfrica2 strains of Helicobacter pylori, which are postulated to have evolved in isolation for many millennia in people of San ethnicity. Although previously considered to be ancestral to Helicobacter acinonychis, the hpAfrica2 strains differ markedly from H. acinonychis in their gene arrangement. These data provide new insights into Helicobacter evolution.

Novel 180- and 480-base-pair insertions in African and African-American strains of Helicobacter pylori.

Helicobacter pylori is a genetically diverse bacterial species that chronically infects human stomachs and sometimes causes severe gastroduodenal disease. Studies of polymorphic DNA sequences can suggest geographic origins of individual strains. Here, we describe a 180-bp insertion (ins180), which is just after the translation stop of a gene of unknown function, near the promoter of jhp0152-jhp0151 two-component signal transduction genes in strain J99, and absent from this site in strain 26695. This ins180 insertion was found in 9 of 9 Gambian (West African), 9 of 20 (45%) South African, and 9 of 40 (23%) Spanish strains but in only 2 of 20 (10%) North American strains and none of 20 Lithuanian, 20 Indian, and 20 Japanese strains. Four South African isolates that lacked ins180 and that belonged to an unusual outlier group contained a 480-bp insertion at this site (ins480), whereas none of 181 other strains screened contained ins480. In further tests 56% (10 of 18) of strains from African Americans but only 17% (3 of 18) of strains from Caucasian Americans carried ins180 (P < 0.05). Thus, the H. pylori strains of modern African Americans seem to retain traces of African roots, despite the multiple generations since their ancestors were taken from West Africa. Fragmentary ins180-like sequences were found at numerous sites in H. pylori genomes, always between genes. Such sequences might affect regulation of transcription and could facilitate genome rearrangement by homologous recombination. Apparent differences between African-American and Caucasian-American H. pylori gene pools may bear on our understanding of H. pylori transmission and disease outcome.

Hepatic disease in patients with acquired immunodeficiency syndrome (AIDS).

The acquired immunodeficiency syndrome is now the leading cause of death in the world. Liver involvement in opportunistic infections and neoplasms affecting patients with human immunodeficiency disease syndrome are common. Many of these patients also take many medicines and toxins that are potentially harmful to the liver. This is an overview on the aetiology and possible diagnostic guide to determine liver involvement in patients with HIV infection. A literature review was performed on major published series on the liver and HIV infection between 1985 and 1999, both years inclusive. Data and opinions from 5 general reviews and 31 original articles from MEDLINE on liver disease in patients with HIV infection regarding aetiology, pathology, presentation and patient evaluation are summarised. The liver is frequently affected in patients with AIDS. The majority of the patients have hepatomegaly and abnormal liver enzymes secondary to involvement with opportunities infections, AIDS associated neoplasms and drug therapy. Most of the infections reach the liver by lymphohaematogeneous spread from other sites in the body. Methodical approach in patient evaluation is therefore essential for prompt diagnosis and treatment to minimise morbidity and early mortality.