Lactation performance of Holstein cows treated with 2 formulations of recombinant bovine somatotropin in a large commercial dairy herd in Brazil.

The objectives of this controlled study were to compare the effects of 2 different formulations of recombinant bovine somatotropin (rbST) on milk yield, milk composition (fat and protein), milk somatic cell count, and body condition score (BCS) among dairy cattle in a large commercial herd. Regulatory approved 500-mg zinc sesame oil base rbST (ZSO-rbST; Elanco Animal Health, Greenfield, IN) and vitamin E lecithin base rbST (VEL-rbST; LG Life Sciences, Seoul, South Korea) formulations were administered per the manufacturers' recommendations every 14 d over 17 injection cycles starting at 57 to 70 d of lactation (90 cows per rbST group). Control cows (n = 60) received no rbST. Somatotropin-treated animals (VEL-rbST and ZSO-rbST combined) had increased average milk yield and protein percentage and lower average BCS compared with control cows. For primiparous cows, average milk yield was 37.75 kg/d with the ZSO-rbST treatment and 35.72 kg/d with the VEL-rbST treatment. For multiparous cows, average milk yield was 40.13 kg/d with the ZSO-rbST treatment and 38.81 kg/d with the VEL-rbST treatment. There were no differences in milk fat percentage between VEL-rbST and ZSO-rbST treatments, but milk protein content was greater with VEL-rbST treatment than with ZSO-rbST treatment. Nonetheless, cows treated with ZSO-rbST yielded more kilograms of fat and protein per day than cows treated with VEL-rbST. No significant differences in BCS were found between both rbST treatment groups. The differential increase in milk yield between cows treated with ZSO-rbST and VEL-rbST was driven by rbST response differences both within the 14-d cycle and throughout the 17 injection cycles. The cows treated with VEL-rbST demonstrated a more variable 14-d milk yield response curve, with more pronounced valleys between injections compared with the ZSO-rbST formulation. In addition, only the ZSO-rbST treatment was effective in modifying the lactation persistency compared with control cows. Compared with the VEL-rbST formulation, the ZSO-rbST formulation yielded more kilograms of milk, fat, and protein with less milk variation throughout the seventeen 14-d lactation cycles for both primiparous and multiparous cows.

Evaluation of a national pharmacy-based syndromic surveillance system.

BACKGROUND: Traditional public health surveillance provides accurate information but is typically not timely. New early warning systems leveraging timely electronic data are emerging, but the public health value of such systems is still largely unknown. OBJECTIVE: To assess the timeliness and accuracy of pharmacy sales data for both respiratory and gastrointestinal infections and to determine its utility in supporting the surveillance of gastrointestinal illness. METHODS: To assess timeliness, a prospective and retrospective analysis of data feeds was used to compare the chronological characteristics of each data stream. To assess accuracy, Ontario antiviral prescriptions were compared to confirmed cases of influenza and cases of influenza-like-illness (ILI) from August 2009 to January 2015 and Nova Scotia sales of respiratory over-the-counter products (OTC) were compared to laboratory reports of respiratory pathogen detections from January 2014 to March 2015. Enteric outbreak data (2011-2014) from Nova Scotia were compared to sales of gastrointestinal products for the same time period. To assess utility, pharmacy sales of gastrointestinal products were monitored across Canada to detect unusual increases and reports were disseminated to the provinces and territories once a week between December 2014 and March 2015 and then a follow-up evaluation survey of stakeholders was conducted. RESULTS: Ontario prescriptions of antivirals between 2009 and 2015 correlated closely with the onset dates and magnitude of confirmed influenza cases. Nova Scotia sales of respiratory OTC products correlated with increases in non-influenza respiratory pathogens in the community. There were no definitive correlations identified between the occurrence of enteric outbreaks and the sales of gastrointestinal OTCs in Nova Scotia. Evaluation of national monitoring showed no significant increases in sales of gastrointestinal products that could be linked to outbreaks that included more than one province or territory. CONCLUSION: Monitoring of pharmacy-based drug prescriptions and OTC sales can provide a timely and accurate complement to traditional respiratory public health surveillance activities but initial evaluation did not show that tracking gastrointestinal-related OTCs were of value in identifying an enteric disease outbreak in more than one province or territory during the study period.

The role of penicillin G potassium in managing Clostridium perfringens in broiler chickens.

The efficacy of penicillin G potassium (Pot-Pen) administered via drinking water to manage necrotic enteritis (NE) was investigated in a Clostridium perfringens (CP) challenge study using 1600 broiler chickens assigned to one of four treatment groups: nonchallenged, nonmedicated; challenged, nonmedicated; challenged, Pot-Pen 0.2 g/L; challenged, Pot-Pen 0.4 g/L. Overall mortality due to NE was significantly reduced among Pot-Pen-treated pens; mortality due to other causes did not differ among the treatment groups. Among all birds, growth performance parameters were significantly improved among Pot-Pen-treated pens. When considering birds randomly sacrificed 4 days post-Pot-Pen initiation, mean NE lesion scores were greatest among the challenged, nonmedicated pens; only one of 80 randomly sacrificed birds treated with Pot-Pen had NE lesions. Among the nonmedicated control pens, body weight (BW) was significantly greater among birds that did not have NE-associated lesions. When sacrificed birds were stratified by NE lesion score, there were no significant differences in BW among the treatment groups. Results of this study suggest that CP-associated subclinical disease can significantly reduce broiler performance. Furthermore, the positive effects of treatment with Pot-Pen appeared to be associated with the prevention and/or treatment of NE-specific lesions.

The occurrence and antimicrobial susceptibility of salmonellae isolated from commercially available canine raw food diets in three Canadian cities.

The purpose of the present study was to evaluate the prevalence and antimicrobial resistance patterns of Salmonella isolated from commercially available canine raw food diets in Canada. A total of 166 commercial frozen raw food diet samples were purchased from randomly selected local pet stores in three Canadian cities for a period of 8 months. All samples were evaluated for the presence of Salmonella, serotyped and tested for antimicrobial susceptibility. There was an overall Salmonella prevalence of 21%; chicken was an ingredient for 67% of the Salmonella-positive diets. Eighteen different Salmonella serotypes were recovered, and resistance was observed to 12 of the 16 antimicrobials tested, with the majority of Ontario isolates exhibiting resistance to ampicillin and Calgary isolates to tetracycline. This study demonstrates the potential risk of raw food diets, especially for immunocompromised individuals, and stresses the need for implementing regulatory guidelines for the production of these diets in order to help control and ideally eliminate the bacterial risks associated with their use and consumption.

The occurrence and anti-microbial susceptibility of Salmonellae isolated from commercially available pig ear pet treats.

In Canada, there have been reported outbreaks of human salmonellosis related to exposure to animal-derived pet treats, involving pig ear treats, beef steak patty dog treats and pet treats of seafood origin. As a follow-up to recommendations made to the pig ear treat industry in 1999, a total of 245 pig ear treats were purchased in two Canadian cities to provide evidence of adoption of the recommendations and to determine the current levels of Salmonella contamination of pig ear treats available at pet stores. An overall prevalence of 4% was observed, with isolates exhibiting resistance to up to seven anti-microbials. Serotypes recovered included S. Bovismorbificans, S. Give, S. Derby and S. Typhimurium var. Copenhagen. Although the prevalence observed during this study is lower than the prevalence observed in 1999, pig ear treats should still be considered as a possible source of Salmonella and anti-microbial resistant bacteria to humans and dogs in Canada.

Frozen chicken nuggets and strips and eggs are leading risk factors for Salmonella Heidelberg infections in Canada.

A case-control study was conducted from 1 January to 31 May 2003 to identify risk factors for S . Heidelberg infection in Canada. Controls were pair-matched by age group and telephone exchange to 95 cases. Exposures in the 7 days before illness/interview were assessed using multivariate conditional logistic regression. Consumption of home-prepared chicken nuggets and/or strips [matched odds ratio (mOR) 4.0, 95% confidence interval (CI) 1.4-13.8], and undercooked eggs (mOR 7.5, 95% CI 1.5-75.5) increased the risk of illness. Exposure to a farm setting lowered the risk (mOR 0.22, 95% CI 0.03-1.00). The population-attributable fraction associated with chicken nuggets/strips was 34% and with undercooked eggs was 16%. One-third of study participants did not perceive, handle or prepare chicken nuggets and strips as high-risk products, although the majority of the products on the Canadian market are raw. These findings have prompted changes in product-labelling policy and consumer education.

An international outbreak of salmonellosis associated with raw almonds contaminated with a rare phage type of Salmonella enteritidis.

During the winter of 2000 to 2001, an outbreak due to Salmonella Enteritidis (SE) phage type 30 (PT30), a rare strain, was detected in Canada. The ensuing investigation involved Canadian and American public health and food regulatory agencies and an academic research laboratory. Enhanced laboratory surveillance, including phage typing and pulsed-field gel electrophoresis, was used to identify cases. Case questionnaires were administered to collect information about food and environmental exposures. A case-control study with 16 matched case-control pairs was conducted to test the hypothesis of an association between raw whole almond consumption and infection. Almond samples were collected from case homes, retail outlets, and the implicated processor, and environmental samples were collected from processing equipment and associated farms for microbiological testing. One hundred sixty-eight laboratory-confirmed cases of SE PT30 infection (157 in Canada, 11 in the United States) were identified between October 2000 and July 2001. The case-control study identified raw whole almonds as the source of infection (odds ration, 21.1; 95% confidence interval, 3.6 to infinity). SE PT30 was detected in raw whole natural almonds collected from home, retail, distribution, and warehouse sources and from environmental swabs of processing equipment and associated farmers' orchards. The frequent and prolonged recovery of this specific organism from a large agricultural area was an unexpected finding and may indicate significant diffuse contamination on these farms. Identification of almonds as the source of a foodborne outbreak is a previously undocumented finding, leading to a North American recall of this product and a review of current industry practices.

Comparison of techniques for measurement of rumen pH in lactating dairy cows.

Subacute rumen acidosis is thought to be a common condition in early lactating dairy cattle; however, diagnosis is difficult. There are currently only two techniques available for measuring rumen pH under field conditions: rumenocentesis and oral stomach tube. Sixteen rumen-fistulated cows were sampled in four sites of the rumen (cranial-ventral, caudal-ventral, central, and cranial-dorsal) with a rumen cannula. Rumen pH results were compared to those obtained at the same time with rumenocentesis and with an oro-ruminal (Geishauser) probe. Rumen fluid was obtained between 6 and 12 wk of lactation. Samples were analyzed for pH, lactate, bicarbonate, sodium, potassium, and chloride. Rumen pH results were also compared to those obtained from 24-h continuous rumen pH measurement using indwelling rumen pH probes. Oro-ruminal probe samples had the highest pH values and the highest bicarbonate concentrations. Rumenocentesis samples had the lowest pH values and the lowest bicarbonate concentrations. Small differences in electrolyte concentrations were noted among rumen fluid collection techniques in the different rumen sites. The highest correlations of rumen pH were obtained between rumenocentesis and rumen cannulation (cranial-ventral), and between rumen cannulation (cranial-ventral) and the 24-h indwelling pH meter. Compared with samples obtained from the cranial-ventral rumen, rumenocentesis was more sensitive than the oro-ruminal probe in the measurement of low rumen pH; both techniques were moderately specific. The most accurate field technique was rumenocentesis. Improved field techniques are required for better on-farm diagnosis of subacute rumen acidosis.

Solution structures of casein peptides: NMR, FTIR, CD, and molecular modeling studies of alphas1-casein, 1-23.

To determine its potential for interacting with other components of the casein micelle, the N-terminal section of bovine alphas1-casein-B, residues 1-23, was investigated with nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) and circular dichroism (CD) spectroscopies, and molecular modeling. NMR data were not consistent with conventional alpha-helical or beta-sheet structures, but changes in N-H proton chemical shifts suggested thermostable structures. Both CD and FTIR predicted a range of secondary structures for the peptide (30-40% turns, 25-30% extended) that were highly stable from 5 degrees C to 25 degrees C. Other conformational elements, such as loops and polyproline II helix, were indicated by FTIR only. Molecular dynamics simulation of the peptide predicted 32% turns and 27% extended, in agreement with FTIR and CD predictions and consistent with NMR data. This information is interpreted in accord with recent spectroscopic evidence regarding the nature of unordered conformations, leading to a possible role of alphas1-casein (1-23) in facilitating casein-casein interactions.

A descriptive analysis of giardiasis cases reported in Ontario, 1990-1998.

Cases of giardiasis in Ontario were described using notifiable disease data from the Ontario Ministry of Health for the years 1990-1998 inclusive. The mean annual age- and sex-adjusted incidence rate was 25.77 cases per 100,000 population for the 25,289 cases reported. Children under five years of age had the highest incidence of disease. Males had a higher mean annual incidence in all age groups. Four deaths occurred among cases. The most frequently reported symptoms were loose stools or watery diarrhea (50.1%). A seasonal pattern was noted, peaking in late summer and early autumn. The most frequently reported probable risk settings were the home (40.1%) and travel (39.1%). The study findings suggest that a high proportion of cases occur in urban areas and spatial analysis showed the highest incidence around Lake Huron and Georgian Bay. Unfiltered water and person-to-person contact are believed to be important sources of infection.

Structural, dynamic, and enzymatic properties of mixed alpha/beta-oligonucleotides containing polarity reversals.

We employ NMR structure determination, thermodynamics, and enzymatics to uncover the structural, thermodynamic and enzymatic properties of alpha/beta-ODNs containing 3'-3' and 5'-5' linkages. RNase H studies show that alpha/beta-gapmers that are designed to target erbB-2 efficiently elicit RNase H activity. NMR structures of DNA.DNA and DNA.RNA duplexes reveal that single alpha-anomeric residues fit well into either duplex, but alter the dynamic properties of the backbone and deoxyriboses as well as the topology of the minor groove in the DNA.RNA hybrid.

Descriptive analysis of endemic cryptosporidiosis cases reported in Ontario, 1996-1997.

Endemic cryptosporidiosis in Ontario was studied using notifiable disease data from the Ontario Ministry of Health for the years 1996-1997 inclusive. For this study period, 451 endemic cases were identified, corresponding to a provincial mean annual age- and sex-adjusted incidence rate of 2.13 cases per 100,000. Children under five years of age had the highest incidence of disease. Males had a higher incidence than females, except for those 15-19 years of age. Five percent of cases were reported as HIV-positive or having AIDS. The proportion of cases occurring between July and November inclusive (63%) was significantly higher than expected (42%) assuming no seasonal variation (p < 0.01). The proportion of rural cases observed (29%) was significantly higher than expected (17%) based on the Ontario population (p < 0.01). Travel to or prior residence in an endemic area was identified in 22% of the cases where a risk setting was reported (n = 265).

Drinking water quality and health-care utilization for gastrointestinal illness in greater Vancouver.

The risk of microbial disease associated with drinking water is presently a priority concern among North American water jurisdictions. Numerous past outbreaks, together with recent studies suggesting that drinking water may be a substantial contributor to endemic (non-outbreak related) gastroenteritis, demonstrate the vulnerability of many North American cities to waterborne diseases and have fuelled ongoing debates in Canada and the United States concerning the need for stricter water quality guidelines, changes in watershed management policies, and the need for additional water treatment. The Greater Vancouver Regional District (GVRD) water supply system serves approximately two million consumers from a system consisting of three unfiltered surface water supplies (Figure 1). Although GVRD policies reduce the potential for fecal contamination of the source water supplies by humans and domestic animals, the GVRD watersheds support many wildlife species that can potentially shed organisms pathogenic to humans. Because GVRD's water treatment strategy relies principally on watershed protection and chlorination*, and these two strategies together do not eliminate all risk of waterborne disease transmission, it is possible that some disease-causing organisms reach the consumer.

Conformational dynamics in mixed alpha/beta-oligonucleotides containing polarity reversals: a molecular dynamics study using time-averaged restraints.

Nucleic acid duplexes featuring a single alpha-anomeric thymidine inserted into each DNA strand via 3'-3' and 5'-5' phosphodiester linkages exhibit local conformational dynamics that are not adequately depicted by conventional restrained molecular dynamics (rMD) methods. We have used molecular dynamics with time-averaged NMR restraints (MDtar) to explore its applicability to describing the conformational dynamics of two alpha-containing duplexes--d(GCGAAT-3'-3'-alphaT-5'-5'-CGC)2 and d(ATGG-3'-3'-alphaT-5'-5'-GCTC) x r(gagcaccau). In contrast to rMD, enforcing NOE-based distance restraints over a period of time in MDtar rather than instantaneously results in better agreement with the experimental NOE and J-data. This conclusion is based on the dramatic decreases in average distance and coupling constant violations (delta d(av), J(rms), and delta J(av)) and improvements in sixth-root R-factors (R(X)). In both duplexes, the deoxyribose ring puckering behavior predicted independently by pseudorotation analysis is portrayed remarkably well using this approach compared to rMD. This indicates that the local dynamic behavior is encoded within the NOE data, although this is not obvious from the local R(X) values. In both systems, the backbone torsion angles comprising the 3'-3' linkage as well as the (high S-) sugars of the alpha-nucleotide and preceding residue (alpha - 1) are relatively static, while the conformations of the 5'-5' linkage and the sugar in the neighboring beta-nucleotide (alpha + 1) show enhanced flexibility. To reduce the large ensembles generated by MDtar to more manageable clusters we utilized the PDQPRO program. The resulting PDQPRO clusters (in both cases, 13 structures and associated probabilities extracted from a pool of 300 structures) adequately represent the structural and dynamic characteristics predicted by the experimental data.

Solution structure of a DNA.RNA hybrid containing an alpha-anomeric thymidine and polarity reversals: d(ATGG-3'-3'-alphaT-5'-5'-GCTC). r(gagcaccau).

We report the thermodynamic and structural properties of an alpha-containing DNA.RNA nonamer hybrid duplex, d(ATGG-3'-3'-alphaT-5'-5'-GCTC).r(gagcaccau). The RNA strand corresponds to the core of the initiation sequence for the transcript of the erbB-2 oncogene. The tandem anomeric and polarity changes in the DNA strand result in a slight decrease in thermostability (DeltaT(m) = -2.8 degrees C) compared to the unmodified control hybrid. The three-dimensional solution structure determination of the alpha-containing DNA.RNA hybrid, conducted via restrained molecular dynamics using interproton distance (nuclear Overhauser enhancement) and furanose ring torsion angle (J-based) restraints, converged to a final ensemble of structures from unique starting models. In agreement with hyperchromicity and circular dichroism data, the final average structure derived from this ensemble is consistent with an overall A-like motif featuring Watson-Crick base pairing and base stacking across the entire sequence, albeit with localized B-like traits within the DNA strand. Comparative pseudorotation analyses of the J-coupling data for this hybrid and its unmodified control reveal a surprising increase in S-puckering for two nucleotides immediately upstream of the 3'-3' linkage, and the associated narrowing of the minor groove in this portion of the hybrid. Other structural perturbations are localized to and diagnostic of the central alpha-nucleotide and juxtaposed polarity reversals. The structural information presented here has direct relevance to the design of future antisense oligonucleotides composed of these modifications.

Potential contamination of drinking water with Toxoplasma gondii oocysts.

The world's first documented toxoplasmosis outbreak associated with a municipal water supply was recognized in 1995 in Victoria, British Columbia, Canada. It was hypothesized that domestic cat (Felis catus) or cougar (Felis concolor) faeces contaminated a surface water reservoir with Toxoplasma gondii oocysts. An extensive investigation of the Victoria watershed 1 year following the outbreak documented the presence of an endemic T. gondii cycle involving the animals inhabiting the area. Cats and cougars were observed throughout the watershed. Serological evidence of T. gondii infection was demonstrated among domestic cats living in the Victoria area. Cougars were found to shed T. gondii oocysts. Serological evidence of T. gondii infection in deer mice living in the riparian environments of the watershed suggested that T. gondii oocysts were being shed near the water edge. Contamination of Victoria's water supply with T. gondii oocysts potentially occurred during the study period and future waterborne toxoplasmosis outbreaks in this and other communities are possible.

NMR solution structures of [d(GCGAAT-3'-3'-alphaT-5'-5'-CGC)2] and its unmodified control.

We present the high-resolution solution structures of a self-complementary DNA decamer duplex featuring a single alpha-anomeric nucleotide per strand encompassed by a set of 3'-3' and 5'-5' phosphodiester linkages, d(GCGAAT-3'-3'-alphaT-5'-5'-CGC)2, alphaT, and its unmodified control, d(GCGAATTCGC)2, obtained by restrained molecular dynamics. Interproton distance and deoxyribose ring torsion angle restraints were deduced from homonuclear NOESY and DQF-COSY data, respectively. For both the control and alphaT duplexes, excellent global convergence was observed from two different (A- and B-) starting models. The final average structures of the two duplexes are highly homologous, and overall possess the traits characteristic of right-handed B-DNA duplexes. However, localized differences between the two structures stem from the enhanced conformational exchange in the deoxyribose ring of the cytidine following the 5'-5' linkage, the C3'- exo pseudorotation phase angle of the alpha-nucleotide, and unusual backbone torsions in the 3'-3' and 5'-5' phosphodiester linkages. The structural data reported here are relevant to the design of antisense therapeutics comprised of these modifications.

Prevalence of Toxoplasma gondii in Canadian market-age pigs.

During 1991 and 1992, 2,800 market-age pigs were sampled at federally inspected abattoirs from across Canada. Anti-Toxoplasma gondii IgG at titers of > or =1:32 were found in 240 pigs examined by a commercial, latex agglutination test. Seroprevalences ranged from 3.5 to 13.2% in the different regions of the country. Tissue hybridization studies using a previously developed probe demonstrated T. gondii ribosomal RNA in 9 of 36 animals, whereas mouse bioassay testing of heart muscle and diaphragm from all 2,800 pigs failed to demonstrate the presence of infective stages of T. gondii in tissues. Although serology results from this study indicated that Canadian market-age pigs are infected with T. gondii at rates similar to those reported from other parts of North America, mouse bioassay results suggested that Canadian pork products contain low levels of infective organisms. This apparent discrepancy suggests that serological evidence of T. gondii infection in pigs alone does not accurately assess the public health risks associated with consuming improperly cooked pork products.