Pseudomonas aeruginosa mutants defective in glucose uptake have pleiotropic phenotype and altered virulence in non-mammal infection models

Pseudomonas spp. are endowed with a complex pathway for glucose uptake that relies on multiple transporters. In this work we report the construction and characterization of Pseudomonas aeruginosa single and multiple mutants with unmarked deletions of genes encoding outer membrane (OM) and inner membrane (IM) proteins involved in glucose uptake. We found that a triple \u394gltKGF \u394gntP \u394kguT mutant lacking all known IM transporters (named GUN for Glucose Uptake Null) is unable to grow on glucose as unique carbon source. More than 500 genes controlling both metabolic functions and virulence traits show differential expression in GUN relative to the parental strain. Consistent with transcriptomic data, the GUN mutant displays a pleiotropic phenotype. Notably, the genome-wide transcriptional profile and most phenotypic traits differ between the GUN mutant and the wild type strain irrespective of the presence of glucose, suggesting that the investigated genes may have additional roles besides glucose transport. Finally, mutants carrying single or multiple deletions in the glucose uptake genes showed attenuated virulence relative to the wild type strain in Galleria mellonella, but not in Caenorhabditis elegans infection model, supporting the notion that metabolic functions may deeply impact P. aeruginosa adaptation to specific environments found inside the host

Risk factors for HIV/AIDS in a low HIV prevalence site of sub-Saharan Africa

We conducted a hospital-based survey on prevalence and risk factors of HIV-1/2 and other viral infections in Zanzibar archipelago. Blood samples, socio-demographic and behavioural data were collected from 2697 patients. The overall HIV prevalence was 2.9%. About 1.4%, 2.1%, 4.2% of antenatal clinic (ANC) attendees and 2.1%, 3.7%, 5.3% of blood donors were, respectively, HIV-Abs-, HTLV-Abs- and HBs-Ag-positive; 5.5% of blood donors were HCV-affected. Co-infections were rare. Exactly 3.4% of the children aged 6-10 years were HIV-positive. People aged 26-35 years [adjusted odds ratio (AOR) 4.4, 95% CI (confidence interval) 1.72-11.22; P = 0.002], illiterate subjects (AOR 3.6, 95% CI 1.65-7.98; P = 0.001) mobile workers (AOR 7.0, 95% CI 1.41-34.62; P = 0.02) and previously operated patients (AOR 1.9, 95% CI 1.02-3.66; P = 0.04) were at higher risk for HIV/AIDS. Any of the examined factors were associated with hepatitis B virus, hepatitis C virus and human T lymphotropic virus type 1/2 transmission. HIV/AIDS prevention strategies must primarily be addressed to traditional high-risk groups and secondarily to unsafe health care procedures in relatively preserved sub-Saharan areas

Comparative Profiling of <em>Pseudomonas aeruginosa</em> Strains Reveals Differential Expression of Novel Unique and Conserved Small RNAs

<div><p><em>Pseudomonas aeruginosa</em> is a highly adaptable bacterium that thrives in a broad range of ecological niches and can infect multiple hosts as diverse as plants, nematodes and mammals. In humans, it is an important opportunistic pathogen. This wide adaptability correlates with its broad genetic diversity. In this study, we used a deep-sequencing approach to explore the complement of small RNAs (sRNAs) in <em>P. aeruginosa</em> as the number of such regulatory molecules previously identified in this organism is relatively low, considering its genome size, phenotypic diversity and adaptability. We have performed a comparative analysis of PAO1 and PA14 strains which share the same host range but differ in virulence, PA14 being considerably more virulent in several model organisms. Altogether, we have identified more than 150 novel candidate sRNAs and validated a third of them by Northern blotting. Interestingly, a number of these novel sRNAs are strain-specific or showed strain-specific expression, strongly suggesting that they could be involved in determining specific phenotypic traits.</p> </div