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Hurdles to develop point of care diagnostic methods restrict the translation of progress in the health care sector from bench side to bedside. In this article a simple, cost effective fluorescent as well as colorimetric nanosensor was developed for the early and easy detection of hyperbilirubinemia. A stable, water soluble bovine serum albumin stabilised copper nanocluster (BSA CuNC) was used as the fluorescent probe which exhibited strong blue emission (404nm) upon 330nm excitation. The fluorescence of the BSA CuNC can be effectively quenched by the addition of bilirubin by the formation of copper-bilirubin complex. Meanwhile the copper-bilirubin complex resulted in an observable colour change from pale violet to green facilitating colorimetric detection. The prepared sensor displayed good selectivity and sensitivity over other co-existing molecules, and can be used for quantifying bilirubin with a detection limit down to 257fM. Additionally, the as-prepared probe was coated on a paper strip to develop a portable paper strip sensor of bilirubin. Moreover, the method was successfully applied in real sample analysis and obtained promising result., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Recent work has identified the presence of Anaplasma bovis, a tick-borne pathogen of cattle, in a previously undescribed species of tick collected from eastern rock sengis, Elephantulus myurus, in Limpopo Province, South Africa. These small insectivores are endemic to Africa and are important hosts of immature ticks, however, their role as reservoirs of tick-borne pathogens has not been investigated. In order to elucidate the role of sengis in the epidemiology of A. bovis, we screened the blood of 105 sengis from Limpopo Province, South Africa, for the presence of members of the genera Anaplasma and Ehrlichia by PCR. A total of 30/105 (28.6%) of individuals were infected with A. bovis, and nucleotide sequencing revealed the presence of a novel genetic variant of this pathogen. This represents the first evidence that sengis may be natural reservoir hosts of A. bovis., (Copyright © 2013 Elsevier GmbH. All rights reserved.)

In Haemophilus influenzae, as in Escherichia coli, the cAMP receptor protein (CRP) activates transcription from hundreds of promoters by binding symmetrical DNA sites with the consensus half-site 5'-A(1)A(2)A(3)T(4)G(5)T(6)G(7)A(8)T(9)C(10)T(11). We have previously identified 13 H. influenzae CRP sites that differ from canonical (CRP-N) sites in the following features: (1) Both half-sites of these noncanonical (CRP-S) sites have C(6) instead of T(6), although they otherwise have an unusually high level of identity with the binding site consensus. (2) Only promoters with CRP-S sites require both the CRP and Sxy proteins for transcription activation. To study the functional significance of CRP-S site sequences, we purified H. influenzae (Hi)CRP and compared its DNA binding properties to those of the well-characterized E. coli (Ec)CRP. All EcCRP residues that contact DNA are conserved in HiCRP, and both proteins demonstrated a similar high affinity for the CRP-N consensus sequence. However, whereas EcCRP bound specifically to CRP-S sites in vitro, HiCRP did not. By systematically substituting base pairs in native promoters and in the CRP-N consensus sequence, we confirmed that HiCRP is highly specific for the perfect core sequence T(4)G(5)T(6)G(7)A(8) and is more selective than EcCRP at other positions in CRP sites. Even though converting C(6)-->T(6) greatly enhanced HiCRP binding to a CRP-S site, this had the unexpected effect of nearly abolishing promoter activity. A+T-rich sequences upstream of CRP-S sites were also found to be required for promoter activation, raising the possibility that Sxy binds these A+T sequences to simultaneously enable CRP-DNA binding and assist in RNA polymerase recruitment.

Natural competence for DNA uptake is common among bacteria but its evolutionary function is controversial. Resolving the dispute requires a detailed understanding of both how cells decide to take up DNA and how the DNA is processed during and after uptake. We have used whole-genome microarrays to follow changes in gene expression during competence development in wild-type Haemophilus influenzae cells, and to characterize dependence of competence-induced transcription on known regulatory factors. This analysis confirmed the existence of a postulated competence regulon, characterized by a promoter-associated 22 bp competence regulatory element (CRE) closely related to the cAMP receptor protein (CRP) binding consensus. This CRE regulon contains 25 genes in 13 transcription units, only about half of which have been previously associated with competence. The new CRE genes encode a periplasmic ATP-dependent DNA ligase, homologs of SSB, RadC and the Bacillus subtilis DNA uptake protein ComEA, and eight genes of unknown function. Competence-induced transcription of genes in the CRE regulon is strongly dependent on cAMP, consistent with the known role of catabolite regulation in competence. Electrophoretic mobility-shift assays confirmed that CRE sequences are a new class of CRP-binding site. The essential competence gene sxy is induced early in competence development and is required for competence-induced transcription of CRE-regulon genes but not other CRP-regulated genes, suggesting that Sxy may act as an accessory factor directing CRP to CRE sites. Natural selection has united these 25 genes under a common regulatory mechanism. Elucidating this mechanism, and the functions of the genes, will provide a valuable window into the evolutionary function of natural competence.