Complete genome sequences of Mycoplasma cynos and Mycoplasma felis isolated from dogs and cats with infectious respiratory disease

Mycoplasma cynos is a primary agent of pneumonia in dogs, and Mycoplasma felis is associated with upper respiratory tract disease in cats. We present complete genome sequences of 26 isolates from clinically affected dogs and cats. These genome sequences will facilitate new molecular and epidemiological analyses.

Additional diagnoses of Echinococcus multilocularis in eastern chipmunks (Tamias striatus) from southern Ontario - results from ongoing surveillance for E. multilocularis in intermediate hosts in Ontario, Canada

Echinococcus multilocularis, a cestode with zoonotic potential, is now known to have a high prevalence in wild canid definitive hosts of southern Ontario. The distribution of E. multilocularis across this region in red foxes (Vulpes vulpes) and coyotes (Canis latrans) is widespread yet heterogenous. In contrast, confirmed diagnoses of E. multilocularis in wild free-ranging intermediate hosts within Ontario are currently limited to a single eastern chipmunk (Tamias striatus). These findings prompted ongoing surveillance efforts in intermediate host species, primarily rodents. Our report describes the results of passive surveillance through wildlife carcass submissions to the Canadian Wildlife Health Cooperative (CWHC) and targeted active sampling of small mammal species from 2018 to 2023; a second and third eastern chipmunk were found to be infected with E. multilocularis. However, these were the only occurrences from surveillance efforts which collectively totaled 510 rodents and other small mammals. Continued surveillance for E. multilocularis in intermediate hosts is of high importance in light of the recent emergence of this parasite in Ontario.

Paranannizziopsis spp. infections in wild snakes and a qPCR assay for detection of the fungus

The emergence of ophidiomycosis (or snake fungal disease) in snakes has prompted increased awareness of the potential effects of fungal infections on wild reptile populations. Yet, aside from Ophidiomyces ophidiicola, little is known about other mycoses affecting wild reptiles. The closely related genus Paranannizziopsis has been associated with dermatomycosis in snakes and tuataras in captive collections, and P. australasiensis was recently identified as the cause of skin infections in non-native wild panther chameleons (Furcifer pardalis) in Florida, USA. Here we describe five cases of Paranannizziopsis spp. associated with skin lesions in wild snakes in North America and one additional case from a captive snake from Connecticut, USA. In addition to demonstrating that wild Nearctic snakes can serve as a host for these fungi, we also provide evidence that the genus Paranannizziopsis is widespread in wild snakes, with cases being identified in Louisiana (USA), Minnesota (USA), Virginia (USA), and British Columbia (Canada). Phylogenetic analyses conducted on multiple loci of the fungal strains we isolated identified P. australasiensis in Louisiana and Virginia; the remaining strains from Minnesota and British Columbia did not cluster with any of the described species of Paranannizziopsis, although the strains from British Columbia appear to represent a single lineage. Finally, we designed a pan-Paranannizziopsis real-time PCR assay targeting the internal transcribed spacer region 2. This assay successfully detected DNA of all described species of Paranannizziopsis and the two potentially novel taxa isolated in this study and did not cross-react with closely related fungi or other fungi commonly found on the skin of snakes. The assay was 100% sensitive and specific when screening clinical (skin tissue or skin swab) samples, although full determination of the assay's performance will require additional follow up due to the small number of clinical samples (n = 14 from 11 snakes) available for testing in our study. Nonetheless, the PCR assay can provide an important tool in further investigating the prevalence, distribution, and host range of Paranannizziopsis spp. and facilitate more rapid diagnosis of Paranannizziopsis spp. infections that are otherwise difficult to differentiate from other dermatomycoses.

Study of pharyngeal airway morphology with CBCT: Benefits of four premolar extraction orthodontic treatments

BACKGROUND AND AIM

Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy.

PATIENTS AND METHODS

Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests.

RESULTS

In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly.

CONCLUSION

Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.

A novel Bacillus sp. with rapid growth property and high enzyme activity that allows efficient fermentation of soybean meal for improving digestibility in growing pigs

AIMS

Soybean meal (SBM) contributes high-quality dietary protein for pigs. However, it also contains antinutritional factors such as allergenic high molecular weight proteins and non-starch polysaccharides (NSP) that limit its use. Therefore, the objective of this study was to screen and characterize a robust Bacillus sp. from camel dung for soybean meal fermentation to improve the digestibility in growing pigs.

METHODS AND RESULTS

Molecular characterization revealed that isolate 9 (hereinafter referred to as "CP-9") was a Bacillus subtilis strain. It secreted cellulase (0.07 U ml-1 ), xylanase (1.91 U ml-1 ), and amylase (2.66 U ml-1 ) into the culture supernatant. Isolate CP-9 showed rapid growth on LB agar plates and grew at a wide range of pH (3.0-9.0) and temperatures (23-50°C) in LB broth. Protein profiling of SBM using SDS-PAGE showed a significant reduction of large globular proteins to small peptides after 48 h of fermentation. On a dry matter basis, neutral detergent fibre (NDF) of the fermented SBM (F-SBM) was decreased by 34.25% (from 9.72 to 7.24%) with an increase in CP content by 16.54% (from 48.74 to 56.80%). Pigs fed with a semi-purified diet formulated with F-SBM as the sole source of crude protein had higher (p < 0.05) apparent ileal digestibility (AID) of DM (80.0 vs. 71.7%), ash (55.6 vs. 36.1%), CP (84.2 vs. 78.3%), NDF (70.9 vs. 66.0%), and ADF (62.4 vs. 53.3%) compared with pigs fed with unfermented soybean meal (UF-SBM).

CONCLUSIONS

A novel Bacillus subtilis strain CP-9 was isolated and characterized from camel dung for efficient fermentation of SBM. This bacterium ameliorates physico-chemical characteristics of F-SBM and improved nutrient digestibility in growing pigs.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our data suggest that a low-cost solid-state SBM fermentation was developed using this newly isolated bacterium. The resultant F-SBM improved the nutrient digestibility in growing pigs.

Widespread occurrence of Batrachochytrium dendrobatidis in Ontario, Canada, and predicted habitat suitability for the emerging Batrachochytrium salamandrivorans

Chytridiomycosis, caused by the fungi Batrachochytrium dendrobatidis and Batrachochytrium salamandrivorans, is associated with massive amphibian mortality events worldwide and with some species’ extinctions. Previous ecological niche models suggest that B. dendrobatidis is not well‐suited to northern, temperate climates, but these predictions have often relied on datasets in which northern latitudes are underrepresented. Recent northern detections of B. dendrobatidis suggest that these models may have underestimated the suitability of higher latitudes for this fungus. We used qPCR to test for B. dendrobatidis in 1,041 non‐invasive epithelial swab samples from 18 species of amphibians collected across 735,345 km² in Ontario and Akimiski Island (Nunavut), Canada. We detected the pathogen in 113 samples (10.9%) from 11 species. Only one specimen exhibited potential clinical signs of disease. We used these data to produce six Species Distribution Models of B. dendrobatidis, which classified half of the study area as potential habitat for the fungus. We also tested each sample for B. salamandrivorans, an emerging pathogen that is causing alarming declines in European salamanders, but is not yet detected in North America. We did not detect B. salamandrivorans in any of the samples, providing a baseline for future surveillance. We assessed the potential risk of future introduction by comparing salamander richness to temperature‐dependent mortality, predicted by a previous exposure study. Areas with the highest species diversity and predicted mortality risk extended 60,530 km² across southern Ontario, highlighting the potential threat B. salamandrivorans poses to northern Nearctic amphibians. Preventing initial introduction will require coordinated, transboundary regulation of trade in amphibians (including frogs that can carry and disperse B. salamandrivorans), and surveillance of the pathways of introduction (e.g., water and wildlife). Our results can inform surveillance for both pathogens and efforts to mitigate the spread of chytridiomycosis through wild populations.

SARS-CoV2 spike protein gene variants with N501T and G142D mutation-dominated infections in mink in the United States

Large numbers of mink have been infected with SARS-CoV2 containing the spike protein Y453F mutation in Europe, causing zoonosis concerns. To evaluate the genetic characteristics of the U.S. and Canadian mink-derived SARS-CoV2 sequences, we analyzed all animal-derived (977) and all Canadian (19,529) and U.S. (173,277) SARS-CoV2 sequences deposited in GISAID from December 2019 to March 12, 2021, and identified 2 dominant novel variants, the N501T-G142D variant and N501T-G142D-F486L variant, in the U.S. mink-derived SARS-CoV2 sequences. These variants were not found in mink from Canada or other countries. The Y453F mutation was not identified in the mink-derived sequences in the United States and Canada. The N501T mutation occurred 2 mo earlier in humans than in mink in the United States, and the novel N501T-G142D and N501T-G142D-F486L variants were found in humans prior to mink. Our results suggest that the novel SARS-CoV2 variants may have evolved during human infection and were then transmitted to mink populations in the United States.

Identification of Antimicrobial Resistance-Associated Genes through Whole Genome Sequencing of Mycoplasma bovis Isolates with Different Antimicrobial Resistances

Antimicrobial resistance (AMR) in Mycoplasma bovis has been previously associated with topoisomerase and ribosomal gene mutations rather than specific resistance-conferring genes. Using whole genome sequencing (WGS) to identify potential new AMR mechanisms for M. bovis, it was found that a 2019 clinical isolate with high MIC (2019-043682) for fluoroquinolones, macrolides, lincosamides, pleuromutilins and tetracyclines had a new core genome multilocus sequencing (cgMLST) type (ST10-like) and 91% sequence similarity to the published genome of M. bovis PG45. Closely related to PG45, a 1982 isolate (1982-M6152) shared the same cgMLST type (ST17), 97.2% sequence similarity and low MIC results. Known and potential AMR- associated genetic events were identified through multiple sequence alignment of the three genomes. Isolate 2019-043682 had 507 genes with non-synonymous mutations (NSMs) and 67 genes disrupted. Isolate 1982-M6152 had 81 NSMs and 20 disruptions. Using functional roles and known mechanisms of antimicrobials, a 55 gene subset was assessed for AMR potential. Seventeen were previously identified from other bacteria as sites of AMR mutation, 38 shared similar functions to them, and 11 contained gene-disrupting mutations. This study indicated that M. bovis may obtain high AMR characteristics by mutating or disrupting other functional genes, in addition to topoisomerases and ribosomal genes.

Diversity of Mycoplasma hyopneumoniae strains from pigs across Ontario, Canada

Mycoplasma hyopneumoniae causes highly contagious swine enzootic pneumonia worldwide. It has been reported that highly diversified M. hyopneumoniae strains exist in different parts of the world. We found p146 gene sequencing analysis, an affordable and simple-to-perform typing method, to be specific and highly sensitive when applied to the molecular typing of 113 M. hyopneumoniae-positive clinical samples directly without culture. The samples were submitted to the Animal Health Laboratory at the University of Guelph (Ontario, Canada) during 2009-2017 from 40 different geographic areas in Ontario. Using a previously described criterion of grouping strains with < 4-bp differences into the same molecular type (p146 type), the 113 clinical samples clustered into 19 p146 genotypes. Dominant types were found in 2016 and 2017 only, indicating that highly diversified M. hyopneumoniae strains existed in Ontario. Some strains from the same geographic location but different years had the same sequence types, indicating that the same strain types circulate persistently in the field. Different p146 genotypes were also identified from similar geographic locations, indicating that either M. hyopneumoniae strains are prone to mutation or that multiple strains can infect the same or nearby swine production units.

[Clinical study on the reduction of ocular surface bacteria in pre-operative cataract surgery patients by cleansing the eyelid margins]

Objective: To explore the clinical significance of ocular surface bacteria inhibition by cleaning eyelid margins before surgery in cataract patients. Methods: Case-control study. Thirty-five patients (45 eyes) with age-related cataracts who were proposed to receive treatment of Phacoemulsification combined with cataract extraction and intraocular lens implantation at Peking University 3(rd) hospital were included. The experimental group consisted of 9 males and 15 females with the average age of (69.8±11.5). The control group consisted of 6 males and 15 females with the average age of (61.8±16.2). In the experimental group, bacteria samples from the conjunctival sac and eyelid margins were collected at three times separately and were cultured for identification: first sampling was taken prior to application of any type of antimicrobial measures; second sampling was taken after application of lid scrub twice daily for 7 days to cleanse their eyelid margins by the patients;the last sampling was taken after patients' application of Levofloxacin antibiotic eye drops 3 times per day continuously for 3 days prior to surgery. In the control group, bacteria samples from the conjunctival sac and eyelid margins were collected at two times separately and were cultured for identification: first sampling was taken before application of any antimicrobial measures;second sampling was taken after patients' application of only Levofloxacin antibiotic eye drops successively for 3 days before surgery. Then the results of bacteria culture of the two groups above were compared. Results: In the experimental group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 83.3% (20/24), 70.8% (17/24), 45.8% (11/24), respectively; according to the bacteria cultures results of the second sampling (tanken after application of lid scrub for cleaning the eyelid margins for 7 days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 58.3% (14/24), 45.8% (11/24), 25% (6/24), respectively;According to the bacteria cultures results of the third sampling (taken after application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 20.8% (5/24), 20.8% (5/24), 4.2% (1/24), respectively. In the experimental group, we compared the bacterial positive rate of the samples taken after patients' application of antibiotics for 3 days to the bacterial positive rate of the samples taken prior to application of any antibacterial measures to have found that the total positive rate, the positive rates of common bacteria and rare bacteria decreased significantly (P<0.05) and the difference in between are of statistical significance. In the control group, according to the eyelid margins bacteria cultures results of the first sampling (taken before application of any antibacterial measures, the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 81% (17/21), 66.7% (14/21), 19% (4/21), respectively;According to the bacteria cultures results of the second sampling (taken after the application of antibiotic eye drops for three days), the total positive rate, positive rate of common bacteria and positive rate of rare bacteria found in the cultures were 38.1% (8/21), 14.3% (3/21), 33.3% (7/21) respectively. When comparing the experimental group to the control group, the experimental group yielded significantly better results than the control group for the rate of reduction of rare bacteria in the eyelid margin after using antibiotics for 3 days. This is due to the lid scrub being used with the antibiotics. The difference are of statistical significance (χ(2)=6.518, P=0.017). There was no statistically significant difference between the experimental and control group in terms of the total positive rate as well as the positive rate of common bacteria and rare bacteria in the conjunctival sac. Conclusions: The cleaning of the eyelid and eyelid margin with lid scrub prior to cataract surgery combined with antibiotics eye drops will achieve excellent antibacterial effects for common and rare bacteria in the eyelid and conjunctival sac. The antibacterial effect of using lid scrub with antibiotic eye drops is more favorable than that of using antibiotic eye drops only. However, the lid scrub eyelid hygiene products cannot replace preoperative antibiotics independently. (Chin J Ophthalmology, 2018, 54: 445-451).

Changes in antimicrobial susceptibility profiles of Mycoplasma bovis over time

Mycoplasma bovis is a major cause of pneumonia, arthritis, and mastitis in cattle and can lead to significant economic losses. Antimicrobial resistance is a concern and further limits the already short list of drugs effective against mycoplasmas. The objective of this study was to examine changes in in vitro minimum inhibitory concentrations (MICs) of antimicrobials of aminoglycoside, fluoroquinolone, lincosamide, macrolide, pleuromutilin, phenicol, and tetracycline classes for 210 M. bovis isolates collected from 1978 to 2009. The MIC₅₀ values of the various antimicrobials were also compared. The MIC₅₀ levels for enrofloxacin and danofloxacin remained low (0.25 μg/mL) across all 3 decades. MIC₅₀ levels for tetracyclines, tilmicosin, and tylosin tartrate were low in the 1980s, then increased in the 1990s and remained high. In the 1980s, MIC₅₀ levels were low for clindamycin, spectinomycin, and tulathromycin, increased in the 1990s to 8 μg/mL (clindamycin) and 32 μg/mL (spectinomycin and tulathromycin), then decreased again in the 2000s. Members of the fluoroquinolone class of antimicrobials had the lowest MIC₅₀ levels across all 3 decades, which suggests in vitro susceptibility of M. bovis to this class of antimicrobials. Statistically significant associations were observed between MIC values for chlortetracycline, oxytetracycline, tylosin tartrate, and tilmicosin; between clindamycin, tulathromycin, spectinomycin, and tiamulin; and between tylosin tartrate and clindamycin. Changes in MIC levels of various antimicrobials over time show the importance of monitoring the susceptibility of mycoplasmas to antimicrobials. The number of antimicrobials that showed elevated MIC₅₀ levels, and therefore possibly reduced in vitro effectiveness against M. bovis, supports initiatives that promote prudent use of antimicrobials in agriculture.

Neurologic Baylisascaris procyonis infection in a young dog

A 14-week-old female Boston terrier-cross dog with intermittent gastroenteritis and an eosinophilia developed progressive neurologic disease with ataxia progressing to uncontrolled paddling. Autopsy revealed Baylisascaris procyonis larvae in 4 of 7 brain sections, with severe eosinophilic meningoencephalitis. Diagnosis was confirmed with polymerase chain reaction (PCR) and DNA sequencing tests of fresh and paraffin-embedded brain in conjunction with the compatible histologic appearance.

Echinococcus multilocularis in a wild free-living eastern chipmunk (Tamias striatus) in Southern Ontario: A case report and subsequent field study of wild small mammals

Southern Ontario has recently been identified as a risk area for Echinococcus multilocularis, based on surveys of foxes (Vulpes vulpes) and coyotes (Canis latrans) which act as definitive hosts of the parasite. In this manuscript, we describe the first detection of E. multilocularis in an eastern chipmunk (Tamias striatus) in North America. This case, submitted to the Canadian Wildlife Health Cooperative (CWHC) in August 2016 as part of ongoing wildlife disease surveillance activities, represents the first report of alveolar echinococcosis in a wild, free living, intermediate host from southern Ontario, providing further evidence of an established sylvatic cycle of E. multilocularis in this region. The finding prompted a field investigation to identify additional cases of alveolar echinococcosis in small mammals in the summer of 2017. Echinococcus multilocularis was not detected in any of the 196 small mammals submitted to the CWHC from across southern Ontario or in any of the 43 small mammals trapped in the area where the infected chipmunk was found. However, given the suspected low prevalence and patchy distribution of E. multilocularis in small mammals, our negative results do not preclude the established presence of the parasite. This case emphasizes the importance of passive surveillance networks for monitoring new and emerging diseases in wildlife populations.

Isolation of bacteria from fermented food and grass carp intestine and their efficiencies in improving nutrient value of soybean meal in solid state fermentation

Background

Soybean meal is an excellent and cost-effective protein source; however, its usage is limited in the piglet due to the presence of anti-nutritional factors and the antigens glycinin and β-conglycinin. The objective of the current study was to screen and select for bacteria that can be efficiently adopted to ferment soybean meal in order to solve this problem.

Results

Bacteria were isolated from fermented soy foods and the grass carp intestine, and strains selected for high protease, cellulase and amylase activities. The isolated bacteria were characterized as Bacillus cereus, Bacillus subtilis and Bacilus amyloliquefacien, respectively. Fermentation with food-derived Isolate-2 and fish-derived F-9 increased crude protein content by 5.32% and 8.27%, respectively; improved the amino acid profile by increasing certain essential amino acids, broke down larger soy protein to 35 kDa and under, eliminated antigenicity against glycinin and β-conglycinin, and removed raffinose and stachyose in the soybean meal following a 24-h fermentation.

Conclusions

Our results suggest these two B. amyloliquefaciens bacteria can efficiently solid state ferment soybean meal and ultimately produce a more utilizable food source for growing healthy piglets.

Multi-locus sequence types of Mycoplasma bovis isolated from Ontario, Canada in the past three decades have a temporal distribution

A total of 217 Mycoplasma bovis isolates cultured from clinical cases in Ontario, Canada, over the past 30 y were selected to be characterized by a multi-locus sequence typing (MLST) method. Eleven housekeeping genes were evaluated for suitability for MLST; 2 loci that had been used in prior MLST schemes, dnaN and metS, along with hsp70 were chosen for further sequence analysis. The remaining loci- adk, efp, gmk, gyrB, polC, rpoB, tpiA, and uvrC genes-were not used because they had little to no sequence variation. The sequence data from the chosen loci ( dnaN, hsp70, metS) generated 28 sequence types (STs), with the 3 loci having 15, 5, and 7 alleles, respectively. These molecular typing results revealed that the STs had a temporal distribution; over the course of 3 decades, some STs disappeared and new STs appeared. Recent isolates had a greater variety of STs, which may indicate that new strains are emerging more rapidly now than in the past.

[Relationships among illness perceptions, medication beliefs and medication adherence in primary angle closure glaucoma patients]

Objective: To investigate the relationships among illness perception, medication beliefs and medication adherence in primary angle closure glaucoma patients. Methods: It was a cross-sectional study. Morisky 8-item Medication Adherence Questionnaire Chinese Revised, the Brief Illness Perceptions Questionnaire, the Specific Section of the Beliefs about Medicine Questionnaire Chinese Revised were administered to 156 primary angle closure glaucoma patients from Tianjin Eye Hospital. Chi-square test was used to analyze the types of glaucoma, gender, prescription complexity, medicine schedule, other disease and course of disease between the group of adherence and non-adherence. Pearson correlation method was used to analyze the correlations among the illness perception, necessity belief, concerns belief and medication adherence. Structural equation model was used to analyze the mediational role of medication belief between illness perception and medication adherence. Results: In the 156 primary angle closure glaucoma patients being investigated, 37 male and 119 female, the average age was (61.3±8.3) years old. The medication adherence of patients was 83 (53.2%) , the medication non-adherence of patients was 73 (46.8%) . It was showed that prescription complexity and medicine schedule were significantly correlated with medicine adherence (χ(2)=13.64, 11.31; P<0.05); gender, other disease and course of disease were not correlated with medication adherence (χ(2)=1.02, 1.73, 6.08; P>0.05). The scores of illness perception were positively correlated with the necessity belief of medication scores, the scores of concerns belief (r=0.18、0.45, P<0.05), and were negatively associated with medication adherence (r=-0.22, P<0.01). The concerns belief of medication scores were negatively correlated with the medication adherence (r=-0.47, P<0.01). Concerns belief mediates the relationship between illness perception and medication adherence wholly (χ(2)/df=1.73, RMSEA=0.069, NNFI=0.98, CFI=0.98, IFI=0.98) . Conclusions: The types of medicines and the number of glaucoma medication used have a significant influence to the medication adherence in the patients with primary angle closure glaucoma. The patients with greater illness perception performed greater non-adherence can be explained by their higher concerns blief. (Chin J Ophthalmol, 2017, 53: 109-114).

Apparent metabolizable and net energy values of corn and soybean meal for broiler breeding cocks

The AME and net energy (NE) values of 4 corn varieties, including 2 normal corn varieties (Zheng Dan 958 and Xian Yu 335), and one each of waxy corn and sweet corn, and 2 soybean meal samples including regular (RSBM) and dehulled soybean meal (DSBM), were determined in 2 experiments for broiler breeding cocks using the indirect calorimetry method. The 4 test diets in Experiment 1 consisted of each test corn, which replaced 40% of the corn-soybean meal basal diet, and the test diets in Experiment 2 contained 25% RSBM or DSBM, which was used to replace the corn basal diet. Thirty (Experiment 1) or 18 (Experiment 2) 50-week-old Arbor Acre (AA) broiler breeding cocks were used in a completely randomized design. After a 7 d dietary adaptation period, 6 birds as replicates from each treatment were assigned to individual respiration chambers for energy measurement via gaseous exchange and total excreta collection for 10 d. In Experiment 1, the AME, ME intake (MEI), retained energy (RE), NE, and NE:AME ratio values were higher (P < 0.001) in the test diets as compared with the corn-soybean meal basal diet. The AME and NE values in the sweet corn diet were higher (P < 0.05) than those values in the other 3 test diets. The heat production (HP), fasting heat production (FHP), and respiration quotient (RQ) were not influenced by the various experimental diets. The respective AME and NE values were 3,785, 3,775, 3,738, and 3,997 kcal/kg (DM basis), and 2,982, 3,006, 2,959, and 3,146 kcal/kg (DM basis) for Zheng Dan 958, Xian Yu 335, waxy corn, and sweet corn. Birds fed a corn basal diet in Experiment 2 had higher AME, MEI, RE, NE, and NE:AME ratio values (P < 0.001). Soybean meal substitution had no effect on HP, FHP, or RQ. The average AME and NE content was 2,492 and 1,581 kcal/kg (DM basis) for RSBM, and 2,580 and 1,654 kcal/kg (DM basis) for DSBM, respectively.

Application and Field Validation of a PCR Assay for the Detection of Mycoplasma Hyopneumoniae from Swine Lung Tissue Samples

A PCR assay was validated for the detection of Mycoplasma hyopneumoniae in porcine lung tissue. The detection limit of the assay was 0.18 colony-forming units/g of lung sample spiked with M. hyopneumoniae. In field validation, 426 pigs from 220 cases were examined for M. hyopneumoniae infection by M. hyopneumoniae PCR and a fluorescent antibody (FA) test. In total, 103 pig lungs (24.2%) were positive in the PCR test, and 69 pig lungs (16.2%) were positive in the FA test, among which, 62 pigs were positive for both PCR and FA test. Most of the PCR-positive but FA test-negative cases had lesions compatible with M. hyopneumoniae infection. With Bayesian modeling, the diagnostic sensitivity and specificity of the PCR were determined to be 97.3% and 93.0%, respectively.

Effects of flavones of sea buckthorn fruits on growth performance, carcass quality, fat deposition and lipometabolism for broilers

The objective of this study was to evaluate the effects of different levels of flavones of sea buckthorn fruits (FSBF) on growth performance, carcass quality, fat deposition, and lipometabolism for broilers. 240 one-day-old Arbor Acres male broilers were randomly allotted to 4 dietary treatments (0, 0.05%, 0.10%, and 0.15% FSBF) with 6 replicates of 10 birds. Broilers were reared for 42 d. Results showed FSBF quadratically improved average daily feed intake (ADFI), average daily gain (ADG), and final body weight (BW) (P = 0.002, P = 0.019 and P = 0.018, respectively). The abdominal fat percentage in 0.05%, 0.10%, and 0.15% FSBF supplementation groups was decreased by 21.08%, 19.12%, and 19.61% with respect to the control group, respectively (P < 0.05). The intramuscular fat (IMF) content in the breast muscle of the broilers was increased by 7.21%, 23.42% and 6.30% in 0.05%, 0.10% and 0.15% FSBF groups, and that in the thigh meat was raised by 4.43%, 24.63% and 12.32%, compared with the control group, respectively (P < 0.05). FSBF had a quadratic effect on the abdominal fat percentage and IMF in the breast muscle (P < 0.05). Dietary FSBF also modified fatty acids of muscular tissues, resulting in a higher ratio of unsaturated to saturated fatty acids (P < 0.05). Supplementing FSBF in the diet greatly decreased the levels of triglyceride, cholesterol, and low-density lipoprotein cholesterol (P < 0.05). Moreover, the quadratic responses were also observed in the levels of insulin and adiponectin in serum (P = 0.020 and P = 0.037, respectively). Abdominal fat percentage was correlated negatively with insulin and positively with adiponectin (P < 0.05). IMF content in the breast and thigh muscles were correlated positively with insulin, and negatively with adiponectin (P < 0.05). A positive correlation existed between breast muscle, IMF, and leptin (P < 0.05). In conclusion, adding FSBF into the diets affected growth performance and fat deposition of broilers by regulating lipometabolism. Fat deposition and distribution of broilers were closely associated with concentrations of insulin and adiponectin. The optimal level of FSBF supplemented in diet was 0.05 to 0.10% in this study.

Attempts to increase inosinic acid in broiler meat by using feed additives

To explore regulation of inosinic acid content in chicken meat as a result of feed additives, 576 one-day-old male Arbor Acres broilers were randomly allotted into 8 dietary treatments including control, purine nucleotide (P), betaine (B), soybean isoflavone (S), purine nucleotide + betaine (PB), purine nucleotide + soybean isoflavone (PS), betaine +soybean isoflavone (BS), and purine nucleotide + betaine + soybean isoflavone (PBS) by a 2 × 2 × 2 factorial arrangement. At d 42 of age, broilers were slaughtered, and growth performance, carcass characteristics, inosinic acid content, and activities of enzyme closely related to inosinic acid metabolism of broilers were measured. The results revealed that these feed additives did not affect ADG and ADFI of the broilers (P > 0.05). However, supplementing purine nucleotides lowered feed/gain of broilers in PS and PBS groups (P < 0.05). There was a significant interaction on feed/gain of broilers between purine nucleotides and soybean isoflavone (P < 0.05). The abdominal fat percentages in groups B, S, BS, and PBS were lower than the control group, respectively (P < 0.05). The thigh muscle percentages of groups P and B were higher than that of group PB (P < 0.05). There were certain interactions on the percentage of thigh muscle (P = 0.05) and abdominal fat (P < 0.05) between P, B, and S groups. Compared with the control group, inosinic acid content in broiler breast meat was improved by using feed additives (P < 0.05). Supplementing purine nucleotides, betaine, soybean isoflavone, and their combinations increased alkaline phosphatase activity in breast meat of broilers (P < 0.05). Purine nucleotides improved the activity of adenosine deaminase, but decreased the activity of 5'-nucleotidase. Soybean isoflavone lowered the activity of alkaline phosphatase. There were no significant interactions on activities of creatine kinase, adenosine deaminase, alkaline phosphatase, and 5'-nucleotidase between these additives (P > 0.05). The umami rating of broiler breast meat increased in conjunction with supplementing these additives. In conclusion, supplementing standard feed with the additives investigated in this study could improve inosinic acid content in chicken meat by increasing synthase activity or inhibiting degradation enzyme activity without inferior growth performance and carcass quality.

Prion protein genotypes of sheep as determined from 3343 samples submitted from Ontario and other provinces of Canada from 2005 to 2012

This study analyzed sheep prion protein (PrP) genotypes of samples submitted from Ontario and other provinces of Canada to the Animal Health Laboratory at the University of Guelph, Guelph, Ontario, between 2005 and 2012. In Ontario, the proportion of scrapie-resistant sheep increased from 2005 to 2012 as evidenced by an increase in the ARR haplotype. When Canadian provinces (Alberta, Ontario, Quebec, and Nova Scotia) were compared from 2008 to 2012, a high proportion of scrapie-resistant sheep was found in all the provinces. The proportions of resistant sheep were lower in Alberta and Quebec than in Ontario and Nova Scotia. Alberta had higher proportions of susceptible sheep and a higher frequency of VRQ alleles, and Quebec had a higher frequency of the ARQ allele.

Evaluation of a real-time polymerase chain reaction assay of the outer membrane protein P2 gene for the detection of Haemophilus parasuis in clinical samples

A real-time polymerase chain reaction (PCR) assay of the outer membrane protein (OMP) P2 gene was developed and used to test 97 putative Haemophilus parasuis pure cultures and 175 clinical tissue samples. With standard culture isolation as the gold standard, the diagnostic sensitivity and specificity of the PCR assay were determined to be 83% and 80%, respectively.

Enhanced expression and significance of glycosylphosphatidylinositol anchor attachment protein 1 in colorectal cancer

The aim of this study was to investigate the expression of glycosylphosphatidylinositol anchor attachment protein 1 (GPAA1) and its significance in patients with colorectal cancer. Fifty-two patients with primary colorectal cancer were included in this study. GPAA1 expression was detected by immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blot analysis. A cell invasion assay was performed by the transwell method. The interacting proteins of GPAA1 were detected by co-immunoprecipitation and matrix assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF/TOF-MS). The expression of GPAA1 mRNA and protein in primary colorectal tumor tissues and liver metastasis tissues was significantly higher than that in normal mucosa tissues (P < 0.01). The number of highly expressing GPAA1 cells penetrating the Matrigel membrane was significantly higher than that of mildly expressing GPAA1 cells (P < 0.05). The results of co-immunoprecipitation and MALDI-TOF/TOF-MS confirmed the identity of the protein. GPAA1 is highly expressed in patients with colorectal cancer, which indicates that it might play an important role in the proliferation, invasion, and metastasis of colorectal cancer.

An electrochemical surface plasmon resonance imaging system targeting cell analysis

This paper presents an electrochemical-surface plasmon resonance imaging (EC-SPRI) system, enabling the characterization of optical and electrical properties of cells, simultaneously. The developed surface plasmon resonance (SPR) imaging system was capable of imaging micro cavities with a dimension of 10 μm × 10 μm and differentiated glycerol solutions with a group of refractive indices (RIs). Furthermore, the EC-SPRI system was used to image A549 cells, suggesting corresponding RI and morphology changes during the cell death process. In the end, electrochemical and SPR methods were used in combination, recording oxidation peaks of A549 cells in the cyclic voltage curves and SPR response unit increase, simultaneously.

A prospective study of sheep and goat abortion using real-time polymerase chain reaction and cut point estimation shows Coxiella burnetii and Chlamydophila abortus infection concurrently with other major pathogens

From 2009 to 2011, 163 sheep and 96 goat abortion submissions were received at the Animal Health Laboratory, University of Guelph, Ontario, Canada, for gross and histologic examination, as well as real-time polymerase chain reaction (PCR) testing for Chlamydophila abortus and/or Coxiella burnetii. Additional testing included immunohistochemistry for Toxoplasma gondii and Chlamydophila spp., routine bacterial culture and selective culture for Campylobacter spp., examination of modified acid-fast–stained placenta smears, enzyme-linked immunosorbent assay testing for Chlamydophila spp., and virus isolation. The final diagnosis made for each case by individual pathologists, based on gross and histologic lesions, as well as ancillary testing, was used as a standard to determine the significance of C. abortus and C. burnetii infection. Coxiella burnetii was identified by real-time PCR in 113 of 163 (69.0%) and 72 of 96 (75%) sheep and goat abortion submissions, respectively, but was considered to be significant in causing abortion in only 11 of 113 (10%) sheep and 15 out of 72 (21%) goat submissions that tested positive. Chlamydophila abortus was identified by real-time PCR in 42 of 162 (26%) and 54 of 92 (59%) sheep and goat submissions, respectively, but was considered the cause of the abortion in 16 of 42 (38%) sheep and 34 of 54 (63%) goat submissions that tested positive. Optimal sensitivity and specificity cut points for the real-time PCR copy number for C. abortus and C. burnetii were determined using the final pathology diagnosis as the reference test.

Apparatus for measuring the Seebeck coefficients of highly resistive organic semiconducting materials

A Seebeck coefficient measurement apparatus for high resistance organic semiconductor materials has been designed and built. It can measure materials with resistance over 7 × 10(12) Ω. This is the highest material resistance value ever reported for Seebeck coefficient measurement. A cyclic temperature gradient generation technique and a corresponding algorithm are proposed to eliminate the negative effects of the long term drift of Seebeck voltage. Sources of errors in these measurements are discussed.

A poly(dimethylsiloxane) based prism for surface plasmon resonance imaging system and its application for gas detection

This paper presents a surface plasmon resonance (SPR) imaging system based on a low-cost, convenient poly(dimethylsiloxane) (PDMS) prism featured with a close contact with the gold film. Compared to conventional glass prism, both numerical simulations and experimental studies indicated a deeper but wider absorption peak with a higher coupling angle for the PDMS based prism. System repeatability was quantified by the cycled detection of helium and air, with the effect of the flow rate investigated. Furthermore, five types of gases (nitrogen, air, oxygen, hydrogen, and helium) were detected and differentiated by the SPR system, with a calculated sensitivity of 5 × 10(-6) RIU.

A micro gas chromatography column with a micro thermal conductivity detector for volatile organic compound analysis

In this paper, a micro gas chromatography (μGC) system contained a μGC column and a micro thermal conductivity detector (μTCD) was proposed. In order to reduce the volume of the system, some micro heaters were integrated on the surface and backside of the GC column, which could provide a robust temperature programming capability and rapidly increase the temperature of the μGC column. In addition, a silicon-glass μTCD with four-thermistor thermal conductivity cells that can offer significant advantages over previously reported designs including low dead volume, good thermal isolation, and elimination of the thermal noise was proposed in this paper. Experimental results have indicated that the μGC system with a detection limit of several ppm concentration levels separated and detected the benzene, toluene, and styrene in less than 3 min, and the μGC system also exhibited a good linear response in the test range.

Evaluation of the zoonotic potential of Giardia duodenalis in fecal samples from dogs and cats in Ontario

This study determined the distribution and zoonotic potential of Giardia duodenalis assemblage types among canine and feline fecal samples from Ontario. The effectiveness of Giardia assemblage typing methods by sequencing the genes of small subunit ribosomal RNA (ssu-rRNA), β-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) was evaluated simultaneously. From 2008 to 2010, 118 canine and 15 feline Giardia positive fecal samples were tested. The ssu-rRNA sequencing method typed 64% (75/118) and 87% (13/15) of the Giardia-positive canine and feline samples, respectively. Among the typeable samples, 68% (51/75) of canine samples contained G. duodenalis assemblage D and 31% (23/75) contained G. duodenalis assemblage C (both non-zoonotic assemblage types). Only 1% (1/75) of the typeable canine samples contained a potentially zoonotic assemblage B. In contrast, 100% (13/13) of the typeable feline samples contained potentially zoonotic assemblages A (n = 12) or B (n = 1).

Use of high-resolution melting curve analysis to identify Mycoplasma species commonly isolated from ruminant, avian, and canine samples

A real-time polymerase chain reaction assay coupled with high resolution melting curve analysis (PCR-HRM) was developed for identifying and distinguishing Mycoplasma species commonly isolated from ruminant, avian, and canine samples. The real-time PCR used 1 set of universal primers specific for the spacer region between the 16S ribosomal RNA and the 23S ribosomal RNA genes; the melting curve analysis of the PCR product used a high-resolution melt fluorescent dye. The real-time PCR-HRM assay was able to distinguish M. arginini, M. bovigenitalium, M. bovis, M. bovirhinis, M. canadense, M. cynos, M. spumans, M. iowae, M. meleagridis, and M. agalactiae reference strains. The real-time PCR-HRM assay developed was evaluated by testing field isolates of M. bovis, M. arginini, M. bovirhinis, M. bovigenitalium, M. iowae, and M. spumans with results consistent with those of the fluorescent antibody test.

The emergence of a new strain of porcine circovirus-2 in Ontario and Quebec swine and its association with severe porcine circovirus associated disease--2004-2006

In the late fall of 2004 more severe lesions of porcine circovirus-2 associated disease (PCVAD) than usual occurred during an outbreak of porcine circovirus-2 (PCV-2) infection in Ontario nursery and grower/finisher pigs. The lesions were of unprecedented severity and included diffuse bronchointerstitial pneumonia, granulomatous enteritis, vasculitis, interstitial nephritis, and new lesions of splenic infarction. Some affected herds had up to 50% mortality. The outbreak correlated with the sudden emergence of a variant PCV-2, with PCR restriction fragment length polymorphism (RFLP) type 321. Phylogenetic comparison of ORF2 sequences and full genome sequences showed the new variant to be different from the previously dominant RFLP type 422 viruses, and similar to viruses that had occurred in France and other European and Asian countries. A subsequent retrospective study showed a statistically significant increase in the frequency of histological lesions in lymph node, spleen, lung, small intestine, colon and kidney, for pigs spontaneously infected with RFLP type 321, compared with the older RFLP type 422 strain. Viral burden, based on IHC staining in lymph node, also showed a statistically significant increase in pigs infected with the newer variant RFLP type 321, compared with the older RFLP type 422 strain. This enhanced virulence in pigs infected with PCV-2 RFLP type 321 strain may be related to the genetic differences in this new strain of PCV-2. This virus is now the dominant strain of PCV-2 virus found in Ontario and Quebec swine.

Development and field validation of a Mycoplasma iowae real-time polymerase chain reaction assay

A Mycoplasma iowae real-time polymerase chain reaction (PCR) assay using primers and probes targeting the 16S rRNA gene was developed and field-validated in this study. The assay specifically identified M. iowae with a detection limit of 80 colony-forming units (cfu) per turkey cloacal swab sample (3.2 cfu per PCR reaction). It was validated by testing 154 field turkey cloacal swab samples in parallel with culture isolation. The diagnostic sensitivity of the PCR was 97.6%, and the specificity was 95.5%. The real-time PCR developed in this study is a rapid, sensitive, and cost-effective alternative to culture isolation for detecting M. iowae from cloacal swab samples.

Development of a real-time PCR for detection of Mycoplasma bovis in bovine milk and lung samples

A real-time polymerase chain reaction (PCR) assay using hybridization probes on a LightCycler platform was developed for detection of Mycoplasma bovis from individual bovine mastitis milk and pneumonic lung tissues. The detection limit was 550 colony forming units (cfu)/ml of milk and 650 cfu/25 mg of lung tissue. A panel of bovine Mycoplasma and of other bovine-origin bacteria were tested; only M. bovis strains were positive, with a melting peak of 66.6 degrees C. Mycoplasma agalactiae PG2 was also positive and could be distinguished because it had a melting peak of 63.1 degrees C. In validation testing of clinical samples, the relative sensitivity and specificity were 100% and 99.3% for individual milks and 96.6% and 100% for the lung tissue. Using M. bovis real-time PCR, the M. bovis culture-positive milk samples were estimated to contain between 5 x 10(4) and 7.7 x 10(8) cfu/ml and the M. bovis culture-positive lungs between 1 x 10(3) and 1 x 10(9) cfu/25 mg. Isolation, confirmed with the real-time PCR and colony fluorescent antibody test, showed that at the herd level, the proportion of samples positive for M. bovis isolation in mastitis milk samples submitted to the Mastitis Laboratory, Animal Health Laboratory, University of Guelph, Ontario, Canada, was 2.4% (5/201). We conclude that this probe-based real-time PCR assay is a sensitive, specific, and rapid method to identify M. bovis infection in bovine milk and pneumonic lungs.

Development of a novel protein microarray method for serotyping Salmonella enterica strains

An antibody microarray assay was developed for Salmonella serotyping based on the Kauffmann-White scheme. A model (8 by 15) array was constructed using 35 antibodies for identification of 20 common Salmonella serovars and evaluated using 117 target and 73 nontarget Salmonella strains. The assay allowed complete serovar identification of 86 target strains and partial identification of 30 target strains and allowed exclusion of the 73 nontarget strains from the target serovars.

Evaluation of methods for the identification of Salmonella enterica serotype Typhimurium DT104 from poultry environmental samples

An increase in the prevalence of Salmonella enterica serotype Typhimurium DT104 has been reported worldwide. This study examined the prevalence of this microorganism in poultry environmental samples from commercial layer flocks and pullet environments as well as the sensitivity and specificity of a PCR-based method, and multiple antibiotic resistance profile of Salmonella serogroup B isolates in relation to the serotype and phagetype reference method for the identification of Salmonella Typhimurium DT104. A total of 435 Salmonella isolates were obtained from poultry house environmental samples tested during a 20-month period representing a prevalence of 5.5%. Of these, 313 (72%) isolates were identified as Salmonella serogroup B isolates. These isolates were tested by a PCR-based assay, and for resistance to five antibiotics: ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline (ACSSuT) for the rapid identification of Salmonella Typhimurium DT104. Upon comparing the antibiotic resistance and PCR results with serotype and phage type data, the sensitivity and specificity for the identification of Salmonella Typhimurium DT104 of both methods were found to be 100%, and 99.6%, respectively. Both methods can be completed within 24 h after obtaining an isolate, while serotyping and phagetyping required more than 5 days to complete.

Molecular genetic methods in the veterinary clinical bacteriology laboratory: current usage and future applications

In the last 5 years, numerous molecular methods have been published for the detection and characterization of bacteria in the field of veterinary medicine. PCR has been the most commonly used technology. Although not currently used for clinical veterinary diagnosis, new technologies such as liquid-phase hybridization, real-time PCR, pathogen load determination and DNA/protein microarray have been described and have many possible applications in the clinical bacteriology laboratory because of their sensitivity and efficiency. This review describes the basic principles and application of recently published DNA-based molecular techniques for the purpose of veterinary clinical bacteriological diagnosis. It covers advances in probe hybridization technology, DNA/RNA amplification techniques and other molecular detection methods, including 16S rRNA analysis for bacterial characterization and DNA microarrays for bacterial detection. The review briefly summarizes the application of molecular methods for the diagnosis of specific important bacterial infections of animals, and for other animal pathogens that are slow or difficult to isolate in the clinical bacteriology laboratory. In addition, the molecular detection of antimicrobial resistance genes and of bovine mastitis pathogens is briefly described and current commercially available tests are listed.

Restriction fragment length polymorphism of porcine reproductive and respiratory syndrome viruses recovered from Ontario farms, 1998-2000

From January 1998 to July 2000, 2,456 clinical samples, including lung, tonsil, lymph node, and serum, from 760 cases submitted to the Animal Health Laboratory, Ontario, Canada, were tested for porcine reproductive and respiratory syndrome viruses (PRRSV) using reverse transcriptase polymerase chain reaction (RT-PCR) and RT-PCR product restriction fragment length polymorphism (RFLP) analysis. A total of 516 samples from 284 cases were RT-PCR positive for the PRRSV open reading frame (ORF) 7 sequence. The RT-PCR RFLP typing assay was performed using 2 different sets of primers, amplifying 716 or 933 base pairs of ORF 4, 5, and 6 of PRRSV. Samples from 254 cases were typeable, yielding 34 different RFLP types. Of these, 164 cases had 32 different RFLP types of field or intermediate strains, 86 had a pattern similar to a commercial PRRSV vaccine or VR 2332 strain of the virus, 4 had a RFLP type shared by another commercial vaccine and a field strain. In 4 cases, 2 different RFLP types were identified from tissues from different pigs that were submitted at the same time from the same farm. Of the 195 farms that submitted PRRSV PCR-positive samples, 48 submitted samples on more than 1 occasion during the specified time frame. In 23 of those 48 farms, RFLP patterns of PRRSV differed between submissions, whereas in the other 25 farms, the RFLP pattern remained unchanged. There were 34 different PRRSV patterns identified from 236 cases using the primer set amplifying 716 base pairs of PRRSV. There were 18 cases, consisting of 9 different patterns, typeable only by using the primers amplifying a 933-base pair fragment of the virus.

Preliminary study on differentiation of Leptospira grippotyphosa and Leptospira sejroe from other common pathogenic leptospiral serovars in canine urine by polymerase chain reaction assay

A multiplex polymerase chain reaction (PCR) method using primer sets of G1/G2 and B64-I/B64-II was validated to detect pathogenic leptospira serovars from canine urine samples. The PCR method was found to be specific and sensitive with a detection limit of 100 cells of Leptospira icterohaemorrhagiae per milliliter of urine. The primer set previously designated and erroneously transcribed B64-I/B64-II amplified a DNA fragment of 352 base pairs from Leptospira grippotyphosa and Leptospira sejroe but not from Leptospira autumnalis, Leptospira bratislava, Leptospira canicola, Leptospira hardjo, Leptospira icterohaemorrhagiae, and Leptospira pomona. From 100 diagnostic canine urine samples, 5 were found positive for Leptospira grippotyphosalsejroe with a PCR product of 352 base pairs and 6 were positive for other pathogenic leptospira serovars with a PCR product of 285 base pairs. One 285-base pair product was sequenced and found to be 99.3% homologous to the G1/G2 PCR fragment sequence reported previously. All 352-base pair PCR products of clinical samples and pure cultures of L. grippotyphosa and L. sejroe were sequenced. The 352-base pair fragment sequences of L. grippotyphosa and L sejroe were identical. Only 2 base pairs were found different between the sequences from pure cultures and those from clinical samples. Serum samples from 3 positive cases that generated a PCR product of 352 base pairs were tested by the microscopic agglutination test, and 2 were found to be positive for L. grippotyphosa (1:10,240 and 1:5,120), 1 was positive for L. grippotyphosa (1:320) or L. icterohaemorrhagiae (1:320). The results of this study suggest that the multiplex PCR with the primer set G1/G2 and the erroneously transcribed B64-I/B64-II may be able to differentiate L. grippotyphosa or L. sejroe from other pathogenic leptospira serovars commonly tested for in Canadian diagnostic laboratories.

[Establishment and application of transplantable models of human esophageal carcinoma in nude mice]

We have successfully established two human esophageal carcinoma models in nude mice by transplantation of surgical specimen from patients with esophageal cancer. Histopathological study revealed that one was squamous cell carcinoma (HEC2) and the other adeno-squamous cell carcinoma (HEC6). Light and electron microscopy showed that their morphology was similar to that of the original tumors. The transplanted tumors have been maintained for more than four years through more than 50 passages. The tumors grew steadily and fast. The rate of successful inoculation was 100%. Bleomycin A5 and 5-Fluorouracil (5-Fu) were used for treatment of HEC6. Results showed that Bleomycin A5 exhibited a remarkable growth inhibition on the HEC6. The inhibition rates of two separate experiments were 56.5% and 87.8% respectively (compared with the control group, P < 0.01). The inhibition rates of 5-Fu were 6.5% and 36.6% respectively. Compared with the control group, there was no significant difference statistically HEC2 was treated by X-ray or X-ray combined with hematoporphyrin derivative (HPD), the tumor growth inhibition was 57.7% and 85.4% respectively.

[Transformation of rat esophageal precancerous epithelial cells and its biologic characteristics--establishment of RE25-3 esophageal carcinoma cell line]

A neoplastic transformation cell line (RE25-3) of the rat esophageal precancerous epithelium has been established by in vivo-in vitro method in our laboratory. Ten criteria were used to study the biological characteristics of the neoplastic transformation during various stages: 1. Dysplastic lesion of the esophageal epithelium was induced in wistar rat by oral administration of NSEE. The dysplastic epithelium was then removed and cultured. After several generations of subculture without carcinogen, the dysplastic epithelium showed neoplastic transformation in vitro. 2. The maximum mitotic index of the transformed cell reached 2.0% and two peaks were observed at hour 41 and 96, respectively, while the mitotic index of the normal esophageal cell was 0.6%. 3. DNA measurement was performed by MSP. The results showed disappearance of the diploid cell from the fifth subculture. Tetraploid, heteroploid and aneuploid cells were observed from the third subculture. The aneuploid cells amounted to 86.24%. 4. The number of chromosome increased as the time of culture as well as the number of subculture generation increased. Chromosome aberration was observed. 5. As the number of subculture generation increased, the damage and break of the chromosome increased. Micronuclei rate increased. 6. By incorporation of H3-TdR, DNA synthesis rate increased as the malignancy increased. 7. Growth of the RE25-3 cell was dependent on EGF in the early stage. But after 15 subculture, as neoplastic transformation developed, this dependency disappeared. 8. After 14 generations of subculture, the cell can be cultured in soft ager. 9. Keratin was proved positive within the cell by ABC immuno-histochemistry assay.(ABSTRACT TRUNCATED AT 250 WORDS)

Luteal phase salivary progesterone concentrations in ovulation-induced cycles

Serial paired plasma and salivary progesterone (P) levels were determined in 21 ovulation-induced cycles of 13 women and in 162 luteal saliva samples of 21 normal cycling women. Mean +/- standard error of the mean (SEM) salivary P levels in all ovulation-induced cycles were similar to normal cycles and were 294 +/- 31.5 to 499 +/- 75 pg/ml, whereas the corresponding plasma P levels were 24.9 +/- 5.0 to 51.4 +/- 16.6 ng/ml. Paired plasma and salivary P levels correlated significantly in women induced with clomiphene citrate (r = 0.82), follicle-stimulating hormone (r = 0.80), human menopausal gonadotropins (r = 0.78), and in those who became pregnant (r = 0.95). Luteal phase salivary P levels were 1.0% to 1.3% of the corresponding plasma levels in ovulation-induced cycles. These findings indicate that salivary P may be a useful and convenient alternative to plasma P for assessing ovulation.

[Carcinogenic and promoting effects of fish juice, preserved rice and salted dry fish on the forestomach epithelium of mice and esophageal epithelium of rats]

The carcinogenic and promoting effects of fish juice, preserved rice and salted dry fish from Nanau county, Guangdong province, a high incidence area of esophageal cancer, were studied in mice and rats. The homemade fish juice as well as fish juice in market, whether or not added with NaNO2, did not cause tumor in the forestomach of mice and the esophagus of rats. When the mice were intubated with an initiator, nitrososarcosinethylester (NSEE) twice, no carcinoma was found at the end of the experiment (D 120). Only papilloma appeared in the forestomach epithelium. The incidence was only 37.5%. However, when the mice were intubated with NSEE for 2 times followed by gastric doses of homemade fish juice, the tumor incidence in the forestomach was increased to 89.7%, in which 20.5% was carcinoma. The tumor and carcinoma incidences of initiator (NSEE and NMBzA) group and initiator + market fish juice group in mice and rats were without significant difference. The experimental results show that the homemade fish juice proved distinct promoting effect on the process of cocarcinogenesis initiated by NSEE in the forestomach of mice, while the market fish juice has no significant promoting effect on the forestomach epithelium of mice and the esophageal epithelium of rats. NSEE induced 31.6% carcinoma in the forestomach epithelium of mice on standard diet. While in mice fed with preserved rice and salted dry fish, the carcinoma incidence was increased to 63.6%. It appears that preserved rice and salted dry fish have promoting effect on the process of cocarcinogenesis initiated by NSEE in the forestomach of mice.(ABSTRACT TRUNCATED AT 250 WORDS)