PI3K-AKT network roles in infectious diseases

Kansenshogaku Zasshi. 2008 May;82(3):161-7

Authors: Noguchi M, Kinowaki K

The PI3K-AKT network, which is activated by cytokines or growth factors, mediates intracellular signals to regulate a variety of cellular responses, including antiapoptosis, proliferation, cell cycling, protein synthesis, glucose metabolism, and telomere activity. Genomic mutations, alterations of the PI3K-AKT regulatory network, underlie such diseases as cancer, glucose intolerance (diabetes mellitus), schizophrenia, and/or autoimmune diseases. In addition to direct tumorigenesis involvement by genetically altering human cancer, the PI3K-AKT network underlies the clinical manifestation of different stages of tumorigenic viral infection, such as latent and chronic infection, and malignant transformation of Epstein-Barr, hepatitis C, hepatitis B, and human immunodeficiency virus (HIV) viruses. We summarize updated knowledge on the PI3K-AKT network underlying different phathological viral and/or bacterial infections. Antiviral activity engendered by suppressing of PI3K-AKT activity, rather than directly targeting anticancer activity via oncogenes, may thus open up ways to prevent malignant transformation by tumorigenic viral infection. PMID: 18546844 [PubMed - in process]

Functional analysis of pilQ gene in Xanthomanas oryzae pv. oryzae, bacterial blight pathogen of rice.

J Microbiol. 2008 Apr;46(2):214-20

Authors: Lim SH, So BH, Wang JC, Song ES, Park YJ, Lee BM, Kang HW

Bacterial blight (BB) of rice, caused by Xanthomonas oryzae pv. oryzae (Xoo), is the most devastating bacterial disease in rice. A virulence-attenuated mutant strain HNU89K9 of X. oryzae pv. oryzae (KACC10331), with a transposon insertion in the pilQ gene was used for this study. The pilQ was involved in the gene cluster pilMNOPQ of the Xoo genome. Growth rate of the pilQ mutant was similar to that of wild-type. At level of amino acids, PilQ of Xoo showed that a high sequence identities more than 94% and 70% to Xanthomonas species and to Xyllela fastidiosa, respectively but a low sequence homology less than 30% to other bacterial species. The twitching motility forming a morginal fringe on PSA media was observed on colony of the wild-type strain KACC10331, but not in mutant HNU89K9. Wild-type Xoo cells formed a biofilm on the surface of the PVC plastic test tube, while the mutant strain HNU89K9 did not form a biofilm. The results suggest that the pilQ gene of X. oryzae pv. oryzae plays a critical role in pathogenicity, twitching motility, and biofilm formation. PMID: 18545972 [PubMed - in process]

Hospital antibiotic management in Belgium - results of the ABS maturity survey of the ABS International group.

Wien Klin Wochenschr. 2008 May;120(9-10):284-288

Authors: Struelens MJ, Costers M

BACKGROUND: While debate about optimal organization for hospital antibiotic stewardship programs is ongoing, limited information is available about the implementation of such programs in acute-care institutions. The ABS International project conducted a survey on the implementation and characteristics of hospital antibiotic management programs in several European countries. This paper summarizes the results for Belgium, where a federal program for developing multidisciplinary antibiotic management teams was started in 2002. METHODS: The survey was conducted in April and May 2007. A questionnaire with 39 items to be scored from 0 (absent) to 5 (fully available) was sent to medical directors and chairs of drugs and therapeutics committees in all acute-care hospitals to measure five dimensions of hospital antibiotic management. The results were analyzed by calculating the mean scores for the various items and topics. MAIN FINDINGS: Of 120 questionnaires sent, 46 (38%) were completed and returned in time for analysis. The three regions of the country were well represented by the respondents. The mean country maturity score of 3.75 (range 2.15-4.90) indicated that a well developed antibiotic management system was in place in most hospitals. Over 90% of hospitals had key structural resources and tools available for effective stewardship programs. Performance items that scored high were those related to microbiological diagnostics and surveillance of bacterial resistance (4.41), surveillance of antibiotic consumption (4.16) and organization of antibiotic guidance and support by trained antibiotic management officers (3.81). Items that scored lower were professional development of personnel (3.43) and co-ordination with outside healthcare providers (2.95). Hospitals with several years of funding for their antibiotic officer showed higher scores for antibiotic management but not for diagnostics. CONCLUSIONS: Antibiotic stewardship programs are well developed in Belgian hospitals, particularly in those which first qualified for federal support. Extension of funding and technical assistance should help all hospitals to catch up with excellence standards, provided that adequate support is given to laboratory services and advanced training of professional specialists. PMID: 18545952 [PubMed - as supplied by publisher]

Survival of hydrogen sulfide oxidizing bacteria on corroded concrete surfaces of sewer systems.

Water Sci Technol. 2008;57(11):1721-1726

Authors: Jensen HS, Nielsen AH, Hvitved-Jacobsen T, Vollertsen J

The activity of hydrogen sulfide oxidizing bacteria within corroded concrete from a sewer manhole was investigated. The bacteria were exposed to hydrogen sulfide starvation for up till 18 months, upon which their hydrogen sulfide oxidizing activity was measured. It was tested whether the observed reduction in biological activity was caused by a biological lag phase or by decay of the bacteria. The results showed that the bacterial activity declined with approximately 40% pr. month during the first two months of hydrogen sulfide starvation. After 2-3 months of starvation, the activity stabilized. Even after 6 months of starvation, exposure to hydrogen sulfide for 6 hours a day on three successive days could restore the bacteriological activity to about 80% of the initial activity. After 12 months of starvation, the activity could, however, not be restored, and after 18 months the biological activity approached zero. The long-term survival aspect of concrete corroding bacteria has implications for predicting hydrogen sulfide corrosion in sewer systems subject to irregular hydrogen sulfide loadings, e.g. as they occur in temperate climates where hydrogen sulfide often is a summer-problem only. PMID: 18547922 [PubMed - as supplied by publisher]