Herd-level risk factors associated with the presence of Phage type 21/28 E. coli O157 on Scottish cattle farms

Background  

E. coli O157 is a bacterial pathogen that is shed by cattle and can cause severe disease in humans. Phage type (PT) 21/28 is a subtype of E. coli O157 that is found across Scotland and is associated with particularly severe human morbidity.     

Mycothiol-dependent mycobacterial response to oxidative stress

The effect of exogenous oxidative stress on mycothiol (MSH) levels and redox balance was investigated in mycobacteria. Both the thiol-specific oxidant diamide and hydrogen peroxide induced up to 75% depletion of MSH to form the disulfide form, mycothione (MSSM), in Mycobacterium bovis BCG. In comparison, Mycobacterium smegmatis, a saprophytic mycobacterium, displays a greater tolerance towards these oxidants, reflected by the lack of fluxes in MSH levels and redox ratios upon oxidative stress treatments. The basal ratio of MSH to MSSM was established to be 50:1 in M. bovis BCG and 200:1 in M. smegmatis.     

Gene expression profiling related to the enhanced erythropoiesis in mouse bone marrow cells

Peroxiredoxin II knockout (Prdx II(-/-)) mice had a spontaneous phenotype of hemolytic anemia. In this study, we found that Ter-119(+)CD71(+) cells increased in Prdx II(-/-) mice bone marrow (BM) at 8 weeks of age. We examined the differential expression profiles to bone marrow cells (BMCs) between Prdx II(+/+) and Prdx II(-/-) mice using a cDNA microarray. We identified the 136 candidates were differentially expressed a greater twofold increase or decrease than EPO receptor. In this study, we focused on the up-regulated NBPs during erythropoietic differentiation. According to cDNA microarray results, six NBPs except zfp-127 were up-regulated during erythropoiesis in Prdx II(-/-) mice. Among the six candidates, eIF3-p44, hnRNPH1, G3bp, and Zfpm-1 were dramatically increased at day 7 of the in vitro erythropoietic differentiation of human CD34(+) cells. However, DJ-1 and Rbm3 were slightly increased only at day 12. Our results suggest that up-regulated NBPs might be involved during erythropoietic differentiation.     

The cyclic nucleotide-gated channels AtCNGC11 and 12 are involved in multiple Ca²⁺-dependent physiological responses and act in a synergistic manner

Arabidopsis cyclic nucleotide-gated ion channels (AtCNGCs) form a large family consisting of 20 members. These channels have so far been reported to be involved in a diverse range of physiological phenomena. For example, AtCNGC18 was reported to play an important role in pollen tube growth, while AtCNGC2, 4, 11, and 12 were implicated in mediating pathogen defence. To identify additional functions for AtCNGC11 and 12, various physiological aspects were analysed using both AtCNGC11 and 12 single knockout mutants as well as a double mutant. Although AtCNGC11 and 12 can function as K(+) and Ca(2+) channels in yeast, it was found that the loss of AtCNGC11 and 12 in Arabidopsis caused increased sensitivity to Ca(2+) but not K(+), indicating a specific function for these genes in Ca(2+) signalling in planta. However, they did not show an alteration in Ca(2+) accumulation, suggesting that AtCNGC11 and 12 are not involved in general Ca(2+) homeostasis but rather in the endogenous movement of Ca(2+) and/or Ca(2+) signalling. Furthermore, these channels synergistically contribute to the generation of a Ca(2+) signal that leads to gravitropic bending. Finally, AtCNGC11 and 12 gene expression was induced during dark-induced senescence and AtCNGC11 and 12 knockout mutants displayed enhanced chlorophyll loss, which was even more pronounced in the double mutant, also indicating synergistic roles in senescence. The findings indicate that (i) some CNGC family members have multiple physiological functions and (ii) some plant CNGCs share the same biological function and work in a synergistic manner.     

Analysis of cylindrospermopsin- and microcystin-producing genotypes and cyanotoxin concentrations in the Macau storage reservoir

The Macau storage reservoir (MSR) has experienced algal blooms in recent years, with high levels of Cylindrospermopsis and Microcystis and detectable concentrations of cyanotoxins. To analyze the cyanotoxin-producing genotypes and relate the corresponding cyanotoxins to the water quality parameters, a quantitative real-time polymerase chain reaction was developed and applied to the water samples in three locations of MSR. Cylindrospermopsin polyketide synthetase (pks) gene and a series of microcystin synthetase (mcy) genes were used for identifying and quantifying cylindrospermopsin- and microcystin-producing genes, and the corresponding water parameters were measured accordingly. Our results showed that high concentrations of cylindrospermopsin and low concentrations of microcystin were measured during the study period. There was a strong correlation between the pks gene numbers and cylindrospermopsin concentrations (R ² = 0.95), while weak correlations were obtained between the mcy genes numbers and microcystin concentrations. Furthermore, the pks gene numbers were strongly related to Cylindrospermopsis (R ² = 0.88), cyanobacterial cell numbers (R ² = 0.96), total algae numbers (R ² = 0.95), and chlorophyll-a concentrations (R ² = 0.83), consistent with the dominant species of Cylindrospermopsis among the cyanobacteria existing in MSR. NH₄–N (R ² = 0.68) and pH (R ² = 0.89) were the water quality parameters most highly correlated with the pks gene numbers. These results contribute to monitoring for potential cyanotoxins in raw water.     

Multiplex PCR analysis of clusters of unexplained viral respiratory tract infection in Cambodia

Background

Fevers of unknown origin constitute a substantial disease burden in Southeast Asia. In majority of the cases, the cause of acute febrile illness is not identified.

Methods

We used MassTag PCR, a multiplex assay platform, to test for the presence of 15 viral respiratory agents from 85 patients with unexplained respiratory illness representing six disease clusters that occurred in Cambodia between 2009 and 2012.

Results

We detected a virus in 37 (44%) of the cases. Human rhinovirus, the virus detected most frequently, was found in both children and adults. The viruses most frequently detected in children and adults, respectively, were respiratory syncytial virus and enterovirus 68. Sequence analysis indicated that two distinct clades of enterovirus 68 were circulating during this time period.

Conclusions

This is the first report of enterovirus 68 in Cambodia and contributes to the appreciation of this virus as an important respiratory pathogen.