Supporting new vaccine introduction decisions: lessons learned from the Hib Initiative experience.

The introduction of Haemophilus influenzae type b (Hib) vaccine in developing countries has suffered from a long delay. Between 2005 and 2009, a surge in Hib vaccine adoption took place, particularly among GAVI-eligible countries. Several factors contributed to the increase in Hib vaccine adoption, including support provided by the Hib Initiative, a project funded by the GAVI Alliance in 2005 to accelerate evidence-informed decisions for use of Hib vaccine. This paper reviews the strategy adopted by the Hib Initiative and the lessons learned in the process, which provide a useful model to accelerate uptake of other new vaccines.

Comparison of the cidal activity of tea tree oil and terpinen-4-ol against clinical bacterial skin isolates and human fibroblast cells.

AIMS: The aim of this study was to compare both the antimicrobial activity of terpinen-4-ol and tea tree oil (TTO) against clinical skin isolates of meticillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (CoNS) and their toxicity against human fibroblast cells. METHODS AND RESULTS: Antimicrobial activity was compared by using broth microdilution and quantitative in vitro time-kill test methods. Terpinen-4-ol exhibited significantly greater bacteriostatic and bactericidal activity, as measured by minimum inhibitory and bactericidal concentrations, respectively, than TTO against both MRSA and CoNS isolates. Although not statistically significant, time-kill studies also clearly showed that terpinen-4-ol exhibited greater antimicrobial activity than TTO. Comparison of the toxicity of terpinen-4-ol and TTO against human fibroblasts revealed that neither agent, at the concentrations tested, were toxic over the 24-h test period. CONCLUSIONS: Terpinen-4-ol is a more potent antibacterial agent against MRSA and CoNS isolates than TTO with neither agent exhibiting toxicity to fibroblast cells at the concentrations tested. SIGNIFICANCE AND IMPACT OF THE STUDY: Terpinen-4-ol should be considered for inclusion as a single agent in products formulated for topical treatment of MRSA infection. However, further work would initially be required to ensure that resistance would not develop with the use of terpinen-4-ol as a single agent.

Using HIPE data as a research and planning tool: limitations and opportunities.

BACKGROUND: The Hospital Inpatient Enquiry (HIPE) system is an important information source for research and health service planning activities. However, as it was not designed explicitly for these purposes, some limitations exist. AIMS: To make recommendations that would increase the value of HIPE as a research and planning tool. METHODS: Experiences of using HIPE for research and planning exercises were analysed so as to identify its limitations and their impact on research and planning. RESULTS: Limitations were identified regarding data quality, policy issues and the general system. CONCLUSIONS: To increase the utility of HIPE as a research and planning tool, a number of changes are recommended, including: expanding the system to cover private hospitals and outpatient and emergency services; adopting routine small area and socio-economic coding; adopting unique personal identifiers; publishing regular detailed reports with in-depth analyses; and considering making hospital identifiers available in certain circumstances.

Review article: test and treat or test and scope for Helicobacter pylori infection. Any change in gastric cancer prevention?

A 'test and treat' strategy is advocated for patients with dyspepsia under the age of 45 years, with endoscopy reserved for those with alarm symptoms or aged over 45 years. One of the consequences of this strategy will be a reduction in population infection rates of Helicobacter pylori. It is now clear that H. pylori is one of the prime initiators of gastric cancer with up to 70% of gastric cancers attributable to H. pylori. What remains unclear is if H. pylori reduction will lead to a reduction in gastric cancer.

Mutagenesis and regulation of the cysJ promoter of Escherichia coli K-12.

The cysJ promoter of Escherichia coli K-12, which is positively controlled by the CysB regulatory protein, was localized through the formation of a fusion of cysJ, the gene encoding NADPH-cytochrome c reductase with lacZ. The position of the transcription start point was determined and the orientation of transcription was shown to be counterclockwise on the E. coli K-12 map. Oligodeoxyribonucleotide-directed mutagenesis of the inferred -10 and -35 regions indicated that both sites could be altered to produce promoter 'down' mutations. When the -10 region was made to agree with the -10 consensus sequence, there was increased function under conditions of repression (that is, in the presence of cysteine). Upstream deletions, as well as mutations in a region proposed to be involved in binding of the CysB regulatory protein, identified sequences important for promoter activity from -90 to -78 and from -71 to -66. By comparison of the sequences of four cys promoters, a possible CysB-binding site was found which included the region shown to be required for the positive regulation of the cysJ promoter.

Promoter elements and regulation of expression of the cysD gene of Escherichia coli K-12.

The cysD gene, involved in cysteine biosynthesis in Escherichia coli and Salmonella typhimurium, is positively regulated by the CysB regulatory protein. The cysD promoter of E. coli K-12 in a 492-bp PstI-Eco RI fragment was sequenced. The in vivo transcription start point (tsp) for the cysD gene was determined by the methods of T4 DNA polymerase mapping and mung-bean nuclease mapping. The -10 region of the cysD promoter (TATAGT) is closely homologous to the -10 consensus sequence (TATAAT) for E. coli promoters. The -35 region of this promoter (TTCATT) is less closely related to the -35 consensus sequence (TTGACA). Several mutants were obtained by using a chain-termination method for generating unidirectional deletions. Evidence is presented for a possible CysB protein binding site around -89, thought to be involved in regulation of expression of the cysD gene.

Promoter-detection vectors for Escherichia coli with multiple useful features.

Two promoter-detection vectors have been constructed which enable the cloning and characterization of promoters recognized by the RNA polymerase of Escherichia coli K-12. The intergenic region of phage M13 DNA, present in opposite orientations in the two vectors, permits the preparation of single-stranded DNA of either strand of the insert thus facilitating oligodeoxyribonucleotide heteroduplex mutagenesis and sequencing of both strands by the dideoxy method of chain termination. After mutagenesis, isolates can be screened for changed function by replica-plating colonies to plates containing XGal. Selected isolates can be characterized by nucleotide sequence analysis, to determine the change in structure, and by beta-galactosidase assays, thus measuring the effect of mutagenesis on promoter function. The vectors could also be used like other protein-fusion vectors.

Lambda transducing phage and clones carrying genes of the cysJIHDC gene cluster of Escherichia coli K12.

DNA from each of two specialized transducing lambda phage, lambda dcysJIHD and lambda cysJ, has been analysed by heteroduplex mapping. The segment of the Escherichia coli chromosome carried by lambda dcysJIHD was shown to be large, approximately 18 kb in length, and to replace a large length of lambda DNA, approximately 11 kb, which includes the genes for integration and recombination. Thus lambda dcysJIHD is a bio-type transducing phage. lambda cysJ was shown to have lost very little lambda DNA and to carry about 8 kb of bacterial DNA. Sites for several restriction endonucleases were mapped in the DNA from each phage and cloning experiments located some of the genes of the cluster in relation to the restriction map. Cysteine regulation of the cloned cysJ and cysD genes was shown as well as cysteine regulation of beta-galactosidase in some constructs. The direction of transcription of the cysD gene was established, and from physical evidence the size of the 'silent section' between the cysH and cysD genes was estimated to be at least 11 kb.

Congenital rubella. Monoclonal antibody-defined T cell abnormalities in young adults.

In order to determine if congenital rubella infection is associated with persistent T cell abnormalities, T cell subsets were quantitated in 16 non-institutionalized subjects (ages nine to 21) with the clinical stigmata and history of congenital rubella. Flow cytometric analysis revealed a decreased T4/T8 ratio (mean +/- SEM in subjects with rubella, 1.57 +/- 0.15, p less than 0.01; in normal subjects, 2.3 +/- 0.4; in subjects with type I diabetes, 2.3 +/- 0.3), decreased percent of T4-positive "helper" cells (42.6 +/- 2.3) different from that in both normal subjects (52.6 +/- 2.4, p less than 0.01) and subjects with recent-onset diabetes (51.5 +/- 2.4), and increased percent of T8-positive "suppressor/cytotoxic" T cells (29.9 +/- 1.4, p less than 0.02) relative to that in normal subjects (24.2 +/- 1.5) and subjects with type I diabetes (23.9 +/- 1.4). Five of 16 subjects with congenital rubella had an elevation of la-positive T cells. Approximately 20 percent had antimicrosomal antibodies. One subject had diabetes mellitus and hypothyroidism, one had hypoglobulinemia, and one had previously undiagnosed hyperthyroidism. Glycosylated hemoglobin levels were normal in all except the diabetic subject, and none of the subjects was islet cell antibody-positive. The T cell abnormalities documented may predispose persons with congenital rubella to the development of organ-specific autoimmunity.

Isolation and characterization of a lambda transducing bacteriophage carrying the cysE gene of Escherichia coli K-12.

A specialized lambda transducing phage carrying the cysE and gpsA genes of E. coli K-12 has been isolated. The transducing phage has been separated from the helper phage on equilibrium gradients and has been shown to be defective. Evidence is presented that the phage kil gene is not expressed.

Isolation of a lambdadcys transducing bacteriophage and its use in determining the regulation of cysteine messenger ribonucleic acid synthesis in Escherichia coli K-12.

A defective specialized lambda transducing phage carrying the cysJ, cysI, cysH, and cysD genes has been isolated from a secondary-site lysogen. Deoxyribonucleic acid-ribonucleic acid (DNA-RNA) hybridization studies utilizing this phage have been carried out to detect cysteine-specific messenger RNA (cys mRNA) synthesized in vivo. A vivo. A 3.5- to 9-fold increase in the rate of synthesis of cys mRNA has been detected in the derepressed wild-type (Cys+) strain grown on glutathione compared with a repressed control grown on cystine. Pleiotropic cysE and cysB mutants grown on glutathione were found to possess rates of synthesis of cys mRNA that were significantly lower than their derepressed isogenic parent. The addition of O-acetyl-L-serine to the cysE strain produced a 5.5-fold increase in the rate of synthesis of cys mRNA. These results indicate that cysteine biosynthesis is controlled at the level of transcription by the inducer O-acetylserine, the cysB protein and cyst(e)ine.

Isolation and characterization of cysK mutants of Escherichia coli K12.

cysK mutants, deficient in O-acetylserine sulphydrylase A [O-acetyl-L-serine acetate-lyase (adding hydrogen-sulphide); EC 4.2.99.8], were isolated as strains resistant to selenite or giving a black colour reaction on bismuth citrate indicator medium. All were resistant to the inhibitor I,2,4-triazole. Four independent mutants were found which possessed lowered levels of O-acetylserine sulphydrylase activity and also partially constitutive levels of NADPH-sulphite reductase [hydrogen-sulphide: NADP+ oxidoreductase; EC I.8.I.2]. Strains containing both a cysE mutation and a cysK mutation lacked the constitutive levels of NADPH-sulphite reductase showing that these levels were due to the in vivo concentration of the inducer, O-acetylserine. The cysK locus was found to be 81% cotransducible with the ptsI gene.

Polarity of the cysJIH operon of Salmonella typhimurium.

Certain point and deletion mutants with lesions in the cysJ gene of Salmonella typhimurium have low levels of enzymes coded by the cysI and cysH genes. These results support the hypothesis that an operon exists comprising genes cysJ, I and H which is transcribed in the direction from cysJ to H. The nearby cysC and cysD genes do not form part of this cysJIH operon.