West Nile virus illness in Ontario, Canada: 2017.

BACKGROUND: In Canada, the annual incidence rates of West Nile virus (WNV) illness have fluctuated over the last 15 years. Ontario is one of the provinces in Canada most affected by WNV and, as a result, has implemented robust mosquito and human surveillance programs. OBJECTIVE: To summarize and discuss the epidemiology of WNV illness in Ontario, Canada in 2017, with comparisons to previous years. METHODS: Case data were obtained from the provincial integrated Public Health Information System. Provincial and public health unit (PHU)-specific incidence rates by year were calculated using population data extracted from intelliHEALTH Ontario. RESULTS: In 2017, the incidence of WNV illness in Ontario was 1.1 cases per 100,000 population, with 158 confirmed and probable cases reported by 27 of the province's 36 PHUs. This is the highest rate since 2013, but less than the rate in 2012 (2.0 cases per 100,000 population). Incidence rates in 2017 were highest in Windsor-Essex County and in PHUs in eastern Ontario. While the seasonality is consistent with previous years, the number of cases reported between July and September 2017 was above expected. Most cases were in older age groups (median: 58 years old) and males (59.5% of provincial total); cases with severe outcomes (neurological complications, hospitalizations, deaths) were also disproportionately in older males. CONCLUSION: WNV illness continues to be an ongoing burden in Ontario. The increase in the number of cases reported in 2017, and the increased number of PHUs reporting cases, suggests changing and expanding risk levels in Ontario. Continued mosquito and human surveillance, increased awareness of preventive measures, and early recognition and treatment are needed to mitigate the impact of WNV infections.

The continued rise of Lyme disease in Ontario, Canada: 2017.

BACKGROUND: Lyme disease is an infection caused by the spirochete Borrelia burgdorferi and, in most of North America, is transmitted by the blacklegged tick Ixodes scapularis. Climate change has contributed to the expansion of the geographic range of blacklegged ticks in Ontario, increasing the risk of Lyme disease for Ontarians. OBJECTIVE: To identify the number of cases and incidence rates, as well as the geographic, seasonal and demographic distribution of Lyme disease cases reported in Ontario in 2017, with comparisons to historical trends. METHODS: Data for confirmed and probable Lyme disease cases with episode dates from January 1, 2012, through December 31, 2017, were extracted from the integrated Public Health Information System (iPHIS). Data included public health unit (PHU) of residence, episode date, age and sex. Population data from Statistics Canada were used to calculate provincial and PHU-specific incidence rates per 100,000 population. The number of cases reported in 2017 by PHU of residence, month of occurrence, age and sex was compared to the 5-year averages for the period 2012-2016. RESULTS: There were 959 probable and confirmed cases of Lyme disease reported in Ontario in 2017. This was three times higher than the 5-year (2012-2016) average of 313. The provincial incidence rate for 2017 was 6.7 cases per 100,000 population, although this varied markedly by PHU. The highest incidence rates were found in Leeds-Grenville and Lanark District (128.8 cases per 100,000), Kingston-Frontenac, Lennox and Addington (87.2 cases per 100,000), Hastings and Prince Edward Counties (28.6 cases per 100,000), Ottawa (18.1 cases per 100,000) and Eastern Ontario (13.5 cases per 100,000). Cases occurred mostly from June through September, were most common among males, and those aged 5-14 and 50-69 years. CONCLUSION: In 2017, Lyme disease incidence showed a marked increase in Ontario, especially in the eastern part of the province. If current weather and climate trends continue, blacklegged ticks carrying tick-borne pathogens, such as those causing Lyme disease, will continue to spread into suitable habitat. Monitoring the extent of this geographic spread will inform future clinical and public health actions to detect and mitigate the impact of Lyme disease in Ontario.

A prospective phase III, randomized, double-blind, placebo-controlled study of brodalumab in patients with moderate-to-severe plaque psoriasis.

BACKGROUND: The interleukin-17 cytokine family plays a central role in psoriasis pathogenesis. OBJECTIVES: To evaluate the efficacy and safety of brodalumab, a human anti-interleukin-17 receptor antibody, in treating patients with moderate-to-severe plaque psoriasis. METHODS: In this phase III, double-blind, placebo-controlled study (NCT01708590; AMAGINE-1), adult patients in the U.S.A., Canada and Europe were randomized to brodalumab (140 or 210 mg) or placebo every 2 weeks (Q2W), with an additional dose at week 1, for a 12-week induction phase. At week 12, patients receiving brodalumab who achieved static Physician's Global Assessment 0 or 1 (sPGA success) were rerandomized to the placebo or induction dose. After week 16, patients with sPGA ≥ 3 were re-treated with the induction dose. After ≥ 12 weeks of retreatment, patients with sPGA 2 for ≥ 4 weeks or sPGA ≥ 3 were rescued with brodalumab 210 mg Q2W. At week 12, patients randomized to brodalumab with sPGA ≥ 2 or placebo received brodalumab 210 mg Q2W. Coprimary end points were the percentage of patients with ≥ 75% improvement in Psoriasis Area and Severity Index score (PASI 75) and sPGA success at week 12. RESULTS: There were 661 patients randomized: 220 placebo, 219 brodalumab 140 mg and 222 brodalumab 210 mg. At week 12, 60% (140 mg) and 83% (210 mg) vs. 3% (placebo) achieved PASI 75, and 54% (140 mg) and 76% (210 mg) vs. 1% (placebo) achieved sPGA success. The safety profile was considered acceptable. CONCLUSIONS: Brodalumab therapy resulted in significant clinical benefit and an acceptable safety profile in patients with moderate-to-severe plaque psoriasis.

Extremely short 20-33 nucleotide introns are the standard length in Paramecium tetraurelia.

Paramecium tetraurelia has the shortest known introns as its standard intron length. Sequenced introns vary between 20 and 33 nucleotides in length. The intron sequences were discovered in genomic sequences coding for a variety of different proteins, including phosphatases, kinases, and low-molecular weight GTP-binding proteins. All intron sequences begin with the conserved dinucleotide GT and end with the conserved dinucleotide AG. The sequences are more AT rich than the Paramecium coding sequences. The identified sequences were confirmed as introns by sequencing several cDNA fragments. We report here analysis of the characteristics of 50 separate introns, including size, base composition, and a consensus sequence.

Purification, characterization and structure of protein phosphatase 1 from the cilia of Paramecium tetraurelia.

A type 1 serine/threonine protein phosphatase (PP1) which is mostly localized in the excitable ciliary membranes from the protozoan Paramecium, was purified to homogeneity. Approximately 4 micrograms enzyme of 37 kDa was isolated from 100 l axenic culture. The enzymic properties were characterized using phosphorylase a from rabbit skeletal muscle as a substrate and several known effectors of mammalian PP1. The protozoan PP1 was enzymically indistinguishable from its mammalian congener. The amino acid sequence of the Paramecium PP1 was deduced from its cDNA. The full-length clone was obtained in several steps starting with a pair of degenerate primers made according to the two most conserved peptides of rabbit PP1 and PP2A. The gene encodes a protein of 36,392 Da. The identity of the cloned gene and the isolated ciliary PP1 was unequivocally established by microsequencing of four tryptic and cyanogen-bromide peptides which were generated from the purified protein. Paramecium PP1 shows 75% amino-acid-sequence identity with rabbit PP1 alpha. Areas of major differences are the C-termini and N-termini and a sequence between residues 219-242.

Control of transducer methylation levels in Escherichia coli: investigation of components essential for modulation of methylation and demethylation reactions.

During bacterial chemotaxis in Escherichia coli, adaptation is accomplished by reversible methylation of the transmembrane signal transducers. Methyl groups are added by the CheR protein in a slow response to attractants and removed by the CheB protein in response to repellents. The methylesterase activity of the CheB protein is modulated by a factor that is controlled in a global fashion throughout the cell. By controlling the level of expression of the cheR, cheB, and transducer genes with exogenous promoters on multicopy plasmids, we demonstrate that the modulating factor exists in stoichiometric concentrations relative to CheB protein and that the generation or efficacy of this factor requires the cheA and/or cheW gene products, suggesting that phosphorylation of the methylesterase by CheA may be involved in its global activation. We show that in the absence of any modulation of the CheB activity, the CheR methyltransferase activity is modulated in a local fashion at the transducers, most likely as a result of a conformational change in the transducer protein brought about by the binding of ligand, and does not require CheA or CheW.

Chromosomal transformation of Escherichia coli recD strains with linearized plasmids.

Wild-type Escherichia coli are resistant to genetic transformation by purified linear DNA, probably in part because of exonuclease activity. We demonstrate that E. coli containing a recD mutation could be easily transformed by linearized plasmids containing a selectable marker. The marker was transferred to the chromosome by homologous recombination, whereas plasmid markers not in the region of homology were lost.

Exchange of chromosomal and plasmid alleles in Escherichia coli by selection for loss of a dominant antibiotic sensitivity marker.

Transfer of an allele from a donor DNA to a recipient DNA molecule was selected by the loss of a dominant conditional lethal mutation previously incorporated ito the gene of interest in the recipient DNA. Both the Escherichia coli chromosome and plasmids carrying E. coli genes were used successfully as donor molecules. Recipient molecules for these exchanges were constructed in vitro by using the rpsL gene, which confers sensitivity to streptomycin, to replace segments of specific E. coli genes located either on multicopy plasmids or in the E. coli chromosome. Plasmids carrying such replacements were capable of acquiring chromosomal alleles of the gene(s) of interest, and strains carrying rpsL replacements in the chromosome were capable of acquiring plasmid-encoded alleles at the sight of the rpsL replacement. In both situations, these allele transfers resulted in loss of the rpsL gene from the recipient DNA molecule. The desired transfer events constituted a large percentage of these events, which gave rise to viable colonies when appropriate donor-recipient pairs were subjected to streptomycin selection. Thus, this is a useful approach for transferring alleles of interest from plasmids to the E. coli chromosome and vice versa.