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Genetic diversity of Ehrlichia ruminantium field strains from selected farms in South Africa Full text
2020
Steyn, Helena C.(Onderstepoort Veterinary Research Vaccine Development and Diagnostics) | Pretorius, Alri(Onderstepoort Veterinary Research Vaccine Development and Diagnostics)
Genetic diversity of Ehrlichia ruminantium field strains from selected farms in South Africa Full text
2020
Steyn, Helena C.(Onderstepoort Veterinary Research Vaccine Development and Diagnostics) | Pretorius, Alri(Onderstepoort Veterinary Research Vaccine Development and Diagnostics)
Heartwater is a tick-borne disease caused by the intracellular rickettsial parasite Ehrlichia ruminantium and transmitted by Amblyomma hebraeum ticks. Heartwater is problematic in endemic areas because it causes high mortality in ruminants and leads to economic losses that threaten productivity and food security. This may indicate that there is augmented genetic diversity in the field, which may result in isolates that are more virulent than the Ball3 and Welgevonden isolates. The genetic diversity of E. ruminantium was investigated in this study, focussing on the pCS20 gene region and four polymorphic open reading frames (ORFs) identified by subtractive hybridisation. The 16S ribosomal ribonucleic acid gene confirmed E. ruminantium in brain, blood and tick genomic deoxyribonucleic acid samples (n = 3792) collected from 122 farms that were randomly selected from seven provinces of South Africa where heartwater is endemic. The conserved E. ruminantium pCS20 quantitative polymerase chain reaction (qPCR) assay was used to scan all collected field samples. A total of 433 samples tested positive with the qPCR using the pCS20 gene region, of which 167 were sequenced. The known stocks and field samples were analysed, and phylogenetic trees were generated from consensus sequences. A total of 25 new clades were identified; of these, nine isolates from infected blood could be propagated in cell cultures. These clades were not geographically confined to a certain area but were distributed amongst heartwater-endemic areas in South Africa. Thus, the knowledge of strain diversity of E. ruminantium is essential for control of heartwater and provides a basis for further vaccine development.
Show more [+] Less [-]Genetic diversity of Ehrlichia ruminantium field strains from selected farms in South Africa Full text
2020
Helena C. Steyn | Alri Pretorius
Heartwater is a tick-borne disease caused by the intracellular rickettsial parasite Ehrlichia ruminantium and transmitted by Amblyomma hebraeum ticks. Heartwater is problematic in endemic areas because it causes high mortality in ruminants and leads to economic losses that threaten productivity and food security. This may indicate that there is augmented genetic diversity in the field, which may result in isolates that are more virulent than the Ball3 and Welgevonden isolates. The genetic diversity of E. ruminantium was investigated in this study, focussing on the pCS20 gene region and four polymorphic open reading frames (ORFs) identified by subtractive hybridisation. The 16S ribosomal ribonucleic acid gene confirmed E. ruminantium in brain, blood and tick genomic deoxyribonucleic acid samples (n = 3792) collected from 122 farms that were randomly selected from seven provinces of South Africa where heartwater is endemic. The conserved E. ruminantium pCS20 quantitative polymerase chain reaction (qPCR) assay was used to scan all collected field samples. A total of 433 samples tested positive with the qPCR using the pCS20 gene region, of which 167 were sequenced. The known stocks and field samples were analysed, and phylogenetic trees were generated from consensus sequences. A total of 25 new clades were identified; of these, nine isolates from infected blood could be propagated in cell cultures. These clades were not geographically confined to a certain area but were distributed amongst heartwater-endemic areas in South Africa. Thus, the knowledge of strain diversity of E. ruminantium is essential for control of heartwater and provides a basis for further vaccine development.
Show more [+] Less [-]Study on the prevalence and genetic diversity of Eimeria species from broilers and free-range chickens in KwaZulu-Natal province, South Africa Full text
2020
Fatoba, Abiodun J.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Zishiri, Oliver T.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Blake, Damer P.(The Royal Veterinary College Department of Pathobiology and Population Sciences) | Peters, Sunday O.(Berry College Department of Animal Science) | Lebepe, Jeffrey(University of KwaZulu-Natal School of Life Sciences, College of Agriculture, Engineering and Sciences Department of Biodiversity and Evolutionary Biology) | Mukaratirwa, Samson(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Adeleke, Matthew A.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences)
Study on the prevalence and genetic diversity of Eimeria species from broilers and free-range chickens in KwaZulu-Natal province, South Africa Full text
2020
Fatoba, Abiodun J.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Zishiri, Oliver T.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Blake, Damer P.(The Royal Veterinary College Department of Pathobiology and Population Sciences) | Peters, Sunday O.(Berry College Department of Animal Science) | Lebepe, Jeffrey(University of KwaZulu-Natal School of Life Sciences, College of Agriculture, Engineering and Sciences Department of Biodiversity and Evolutionary Biology) | Mukaratirwa, Samson(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences) | Adeleke, Matthew A.(University of KwaZulu-Natal College of Agriculture, Engineering and Sciences School of Life Sciences)
This study was conducted from January to October 2018 with the objective to determine the prevalence and genetic diversity of Eimeria species in broiler and free-range chickens in KwaZulu-Natal province, South Africa. A total of 342 faecal samples were collected from 12 randomly selected healthy broiler chicken farms and 40 free-range chickens from 10 different locations. Faecal samples were screened for the presence of Eimeria oocysts using a standard flotation method. The species of Eimeria isolates were confirmed by amplification of the internal transcribed spacer 1 (ITS-1) partial region and sequences analysis. Among broiler and free-ranging chickens, 19 out of 41 pens (46.3%) and 25 out of 42 faecal samples (59.5%) were positive for Eimeria infection. Molecular detection revealed the following species: Eimeria maxima, Eimeria tenella, Eimeria acervulina, Eimeria brunetti and Eimeria mitis in all the samples screened. Similarly, polymerase chain reaction assays specific for three cryptic Eimeria operational taxonomic units were negative for all the samples. Phylogenetic analysis of the ITS-1 sequences supported species identity with the greatest variation detected for E. mitis. This study provides information on the range and identity of Eimeria species, and their genetic relatedness, circulating in commercially reared broilers and free-ranging chickens from different locations in KwaZulu-Natal province.
Show more [+] Less [-]Study on the prevalence and genetic diversity of Eimeria species from broilers and free-range chickens in KwaZulu-Natal province, South Africa Full text
2020
Abiodun J. Fatoba | Oliver T. Zishiri | Damer P. Blake | Sunday O. Peters | Jeffrey Lebepe | Samson Mukaratirwa | Matthew A. Adeleke
This study was conducted from January to October 2018 with the objective to determine the prevalence and genetic diversity of Eimeria species in broiler and free-range chickens in KwaZulu-Natal province, South Africa. A total of 342 faecal samples were collected from 12 randomly selected healthy broiler chicken farms and 40 free-range chickens from 10 different locations. Faecal samples were screened for the presence of Eimeria oocysts using a standard flotation method. The species of Eimeria isolates were confirmed by amplification of the internal transcribed spacer 1 (ITS-1) partial region and sequences analysis. Among broiler and free-ranging chickens, 19 out of 41 pens (46.3%) and 25 out of 42 faecal samples (59.5%) were positive for Eimeria infection. Molecular detection revealed the following species: Eimeria maxima, Eimeria tenella, Eimeria acervulina, Eimeria brunetti and Eimeria mitis in all the samples screened. Similarly, polymerase chain reaction assays specific for three cryptic Eimeria operational taxonomic units were negative for all the samples. Phylogenetic analysis of the ITS-1 sequences supported species identity with the greatest variation detected for E. mitis. This study provides information on the range and identity of Eimeria species, and their genetic relatedness, circulating in commercially reared broilers and free-ranging chickens from different locations in KwaZulu-Natal province.
Show more [+] Less [-]Pharmacokinetics and efficacy of trazodone following rectal administration of a single dose to healthy dogs Full text
2020
O'Donnell, Erica M. | Press, Saya A. | Karriker, Margo J. | Istvan, Stephanie A.
OBJECTIVE To determine the pharmacokinetics and efficacy of trazodone following rectal administration of a single dose to healthy dogs. ANIMALS 6 healthy adult dogs. PROCEDURES Each dog received a single dose of trazodone (approx 8 mg/kg) per rectum. Trazodone tablets were crushed into a powder, mixed with 5 mL of tap water, and injected into the rectum via a red rubber catheter. Sedation scores were assigned, and blood samples were collected for determination of plasma trazodone concentration at predetermined times before and after drug administration. Pharmacokinetic parameters were estimated by noncompartmental analysis. RESULTS Plasma trazodone concentration remained below the detection limit for 1 dog even though it became moderately sedate. Median (interquartile [25th to 75th percentile] range [IQR]) maximum plasma trazodone concentration and volume of distribution and clearance corrected for bioavailability were 1.00 μg/mL (0.66 to 1.40 μg/mL), 10.3 L/kg (7.37 to 14.4 L/kg), and 639 mL/kg/h (594 to 719 mL/kg/h), respectively. Median time to maximum plasma trazodone concentration and elimination half-life were 15 minutes (range, 15 to 30 minutes) and 12 hours (IQR, 7.99 to 12.7 hours), respectively. All dogs became mildly or moderately sedate, and the extent of sedation was maximal at a median of 30 minutes (IQR, 30 to 60 minutes) after trazodone administration. No adverse effects were observed. CONCLUSIONS AND CLINICAL RELEVANCE Rectal administration of trazodone may be a viable option for sedation and treatment of anxiety in dogs for which administration of sedatives and anxiolytics by other routes is contraindicated. Further research is necessary to better elucidate the pharmacokinetics and efficacy of trazodone following rectal administration and determine optimal dosing.
Show more [+] Less [-]Feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation of clinically normal canine ovaries Full text
2020
Verpaalen, Valentine D. | Case, J Brad | Dark, Michael J. | Cardenas-Goicoechea, S Joel | Winter, Matt D. | Boston, Sarah E. | Garcia-Pereira, Fernando | Rhoton-Vlasak, Alice S. | Toskich, Beau B.
OBJECTIVE To determine the optimal energy profile for and to assess the feasibility and efficacy of ultrasonographic and laparoscopic guidance for microwave ablation (MWA) of clinically normal canine ovaries. SAMPLE 44 extirpated ovaries from 22 healthy dogs. PROCEDURES In the first of 2 trials, 13 dogs underwent oophorectomy by routine laparotomy. Extirpated ovaries underwent MWA at 45 W for 60 (n = 11) or 90 (12) seconds; 3 ovaries did not undergo MWA and served as histologic controls. Ovaries were histologically evaluated for cell viability. Ovaries without viable cells were categorized as completely ablated. Histologic results were used to identify the optimal MWA protocol for use in the subsequent trial. In the second trial, the ovaries of 9 dogs underwent MWA at 45 W for 90 seconds in situ. Ultrasonographic guidance for MWA was deemed unfeasible after evaluation of 1 ovary. The remaining 17 ovaries underwent MWA with laparoscopic guidance, after which routine laparoscopic oophorectomy was performed. Completeness of ablation was histologically assessed for all ovaries. RESULTS 2 ovaries were excluded from the trial 1 analysis because of equivocal cell viability. Six of 11 ovaries and 10 of 10 ovaries that underwent MWA for 60 and 90 seconds, respectively, were completely ablated. In trial 2, laparoscopic-guided MWA resulted in complete ablation for 12 of 17 ovaries. Dissection of the ovarian bursa for MWA probe placement facilitated complete ablation. CONCLUSIONS AND CLINICAL RELEVANCE Laparoscopic-guided MWA at 45 W for 90 seconds was feasible, safe, and effective for complete ablation of clinically normal ovaries in dogs.
Show more [+] Less [-]Use of a biopolymer delivery system to investigate the influence of interleukin-4 on recruitment of neutrophils in equids Full text
2020
Godbout, Mireille | Vargas, Amandine | Helie, Pierre | Bullone, Michela | Lavoie, Jean-Pierre
OBJECTIVE To use a biopolymer delivery system to investigate the ability of interleukin (IL)-4 to recruit neutrophils into subcutaneous tissues of equids. ANIMALS 16 horses and 2 ponies. PROCEDURES Animals were assigned to 3 experiments (6/experiment). Effects of recombinant equine (Req) IL-4 (100, 250, or 500 ng/site) versus a positive control (ReqIL-8; 100 ng, 250 ng, or 1 μg/site) and a negative control (Dulbecco PBSS or culture medium) on neutrophil chemotaxis were assessed after SC injection into the neck with an injectable biopolymer used as the vehicle. Tissue samples including the biopolymer plug were collected by biopsy at various time points from 3 hours to 7 days after injection. Neutrophil infiltration was evaluated by histologic scoring (experiments 1, 2, and 3) or flow cytometry (experiment 3). RESULTS Histologic neutrophil infiltration scores did not differ significantly among treatments at most evaluated time points. On flow cytometric analysis, log-transformed neutrophil counts in biopsy specimens were significantly greater for the ReqIL-8 treatment (1 μg/site) than the negative control treatment at 3 but not 6 hours after injection; results did not differ between ReqIL-4 and control treatments at either time point. Negative control treatments induced an inflammatory response in most equids in all experiments. CONCLUSIONS AND CLINICAL RELEVANCE Flow cytometry was a more reliable method to estimate neutrophil migration than histologic score analysis. The ReqIL-4 treatment did not induce a detectable neutrophil response, compared with the negative control treatment in this study. Evidence of inflammation in negative control samples suggested the biopolymer is not a suitable vehicle for use in equids.
Show more [+] Less [-]Investigation of optimal sample preparation conditions with potassium triiodide and optimal imaging settings for microfocus computed tomography of excised cat hearts Full text
2020
Simcock, Ian C. | Hutchinson, J Ciaran | Shelmerdine, Susan C. | Matos, Jose Novos | Sebire, Neil J. | Luis Fuentes, Virginia | Arthurs, Owen J.
OBJECTIVE To determine optimal sample preparation conditions with potassium triiodide (I2KI) and optimal imaging settings for microfocus CT (micro-CT) of excised cat hearts. SAMPLE 7 excised hearts (weight range, 10 to 17.6 g) obtained from healthy adult cats after euthanasia by IV injection of pentobarbital sodium. PROCEDURES Following excision, the hearts were preserved in 10% formaldehyde solution. Six hearts were immersed in 1.25% I2KI solution (n = 3) or 2.5% I2KI solution (3) for a 12-day period. Micro-CT images were acquired at time 0 (prior to iodination) then approximately every 24 and 48 hours thereafter to determine optimal sample preparation conditions (ie, immersion time and concentration of I2KI solution). Identified optimal conditions were then used to prepare the seventh heart for imaging; changes in voltage, current, exposure time, and gain on image quality were evaluated to determine optimal settings (ie, maximal signal-to-noise and contrast-to-noise ratios). Images were obtained at a voxel resolution of 30 μm. A detailed morphological assessment of the main cardiac structures of the seventh heart was then performed. RESULTS Immersion in 2.5% I2KI solution for 48 hours was optimal for sample preparation. The optimal imaging conditions included a tube voltage of 100 kV, current of 150 μA, and exposure time of 354 milliseconds; scan duration was 12 minutes. CONCLUSIONS AND CLINICAL RELEVANCE Results provided an optimal micro-CT imaging protocol for excised cat hearts prepared with I2KI solution that could serve as a basis for future studies of micro-CT for high resolution 3-D imaging of cat hearts.
Show more [+] Less [-]Cardiovascular and respiratory effects of carbon dioxide pneumoperitoneum in the domestic rabbit (Oryctolagus cuniculus) Full text
2020
Kabakchiev, Claudia | Valverde, Alex | Singh, Ameet | Beaufrere, Hugues
The objective of this study was to evaluate the effect of intra-abdominal pressure (IAP) on cardiorespiratory parameters during pneumoperitoneum with carbon dioxide in domestic rabbits. Six juvenile female New Zealand white rabbits were assigned to randomized sequences of IAP (0, 4, 8 mmHg) in a crossover study. The following parameters were measured at each IAP: direct arterial blood pressure (ABP); cardiac output, (CO), cardiac index, and stroke volume index (CI, SVI); heart rate; end-tidal carbon dioxide (ETCO(2)); arterial blood gases (PaCO(2), PaO(2)); peak inspiratory pressure (PIP); and peripheral oxygen saturation (SpO(2)). Between IAPs, the abdomen was desufflated for a 5-minute washout period. Mixed linear regression models were used for statistical analysis. Heart rate, SpO(2), and ABP were not significantly affected by IAP, although there was a positive increase in ABP with IAP. Partial pressure of carbon dioxide (PaCO(2)) was increased at an IAP of 8 mmHg and ETCO(2) and PIP were greater with each IAP applied. Cardiac output and CI were significantly decreased with IAP and, although SVI showed the same trend, it was not statistically significant. In conclusion, pneumoperitoneum with carbon dioxide causes an increase in ETCO(2), PaCO(2), and PIP, whereas cardiac output and CI decrease. These cardiorespiratory changes should be considered when determining the optimal IAP for laparoscopic procedures in rabbits.
Show more [+] Less [-]Evaluation of various carbon dioxide laser settings on the time and number of laser beam passes required to make a full-thickness skin incision and amount of laser-induced tissue artifact Full text
2020
Agulian, Lori M. | Mann, F. A. | Middleton, John R. | Kim, Dae Y.
OBJECTIVE To evaluate the time and number of laser beam passes required to make full-thickness skin incisions and extent of laser-induced tissue artifacts following use of a CO(2) laser at various settings. SAMPLE 24 skin specimens from six 5-month-old porcine carcasses. PROCEDURES 4 full-thickness skin specimens were harvested from the flank regions of each carcass within 30 minutes after euthanasia and randomly assigned to 4 treatment groups. Three 5-cm-long incisions were made in each specimen with a CO(2) laser (beam diameter, 0.4 mm) set to deliver a continuous wave of energy alone (groups 1 and 2) or in superpulse mode (groups 3 and 4) at 10 (groups 1 and 3) or 20 (groups 2 and 4) W of power. The time and number of passes required to achieve a full-thickness incision were recorded, and extent of laser-induced tissue artifact (as determined by histologic evaluation) was compared among the 4 groups. RESULTS Mean time required to make a full-thickness skin incision for groups 2 and 4 (power, 20 W) was significantly less than that for groups 1 and 3 (power, 10 W). Mean number of passes was lowest for group 2 (continuous wave at 20 W). Extent of laser-induced tissue artifact was greatest for group 4 (superpulse mode at 20 W). CONCLUSIONS AND CLINICAL RELEVANCE Results provided preliminary information regarding use of CO(2) lasers to make skin incisions in veterinary patients. In vivo studies are necessary to evaluate the effect of various CO(2) laser settings on tissue healing and patient outcome.
Show more [+] Less [-]Assessing of Heavy Metals in Serum of Barki Sheep in Rainfed Area at Matrouh Governorate Full text
2020
Marwa M. Morsy1 | Abd El-Rehim A. El-Ghannam2 | Sherif Y. Saleh2 | Mahmoud M. Arafa3
The present study was conducted to determine serum concentrations of lead (Pb), cadmium (Cd), copper (Cu), zinc (Zn), iron (Fe), and selenium (Se) of Barki sheep reared in the rainfed area at Matrouh Governorate, Egypt. Forty apparently healthy Barki sheep (2-4 years of age) were randomly selected from Marsa Matrouh and El Negaila farms (twenty each) for this study. In addition to twenty healthy Barki sheep aged 2-4 years, obtained from Borg El Arab farm, represented as control. Animals classified into 3 groups according to water source: Borg El Arab as control (Tap water); Matrouh (Rainfall water); El Negaila (Rainfall Water). Water and serum samples were prepared for the detection and estimation of selected metals by using Flame Atomic Absorption Spectrometer. Metal analysis revealed that Pb levels in different water samples were recorded above the EWQS of 0.01 ppm in following: El Negaila > Matrouh > control, Cd levels were recorded in El Negaila (RW) and Matrouh (RW) above recommended limit of 0.003, Se levels were recorded above maximum limit EWQS of 0.01 ppm in control (TW) followed by El Negaila and Matrouh however the levels of Cu, Zn, and Fe from the surveyed areas were below EWQS limits. Serum mineral analysis, Pb level was significantly increased only in examined sheep of El Negaila, Cd levels were higher in examined sheep of El Negaila and Matrouh however, Cu, Zn, and Fe levels were significantly lower compared to the control group. Conclusion: water analysis showed that Cu, Zn, and Fe concentrations were within the levels recommended by EWQS except for Pb, Cd and Se levels which need more attention. Serum analysis revealed high levels of Pb, Cd, and Se however deficient to marginal levels of Zn and Cu were detected in examined sheep. These results should provide a database for the mineral status of Barki sheep and their drinking water quality in Matrouh and El Negaila as well as evaluate environmental pollution status in this area.
Show more [+] Less [-]Occurrence and distribution patterns of the diseases of goat in Dhaka, Bangladesh Full text
2020
Raquib, Ahsan | Uddin, Mohammod Misbah | Chowdhury, Shahidur Rahman | Hossain, Mukter | Rahman, Mahfujur
The study was conducted to determine the occurrence and distribution patterns of diseases of goat in Dhaka, Bangladesh during the period of January 2018 to December 2018. Materials and Methods: A total of 452 goats were recorded during the study period. The diseases were diagnosed based on clinical signs, patient owners complain and laboratory findings. The prevalence was measured according to season and age of the goats which were studied. Statistical analysis was done by Chi-square test and P-value was calculated by using SPSS 25 for windows (SPSS, Inc., Chicago, IL).Results: In this study, 381 (84.29%) goats were found to be diseased from 452 visited goats at Central veterinary Hospital (CVH), Dhaka. The highest prevalence was found with worm infestation (31.42%) followed by PPR (13.72%), miscellaneous (ruminal acidosis, disuria, repeat breeding) (12.16%), pneumonia (10.18%), dermatitis (4.20%), enteritis (3.76%), urolithiasis (3.09%), bloat (2.65%), mastitis (1.55%), tetanus (1.11%) and protozoal diseases (0.44%). Rainy season represented the highest (86.11%) prevalence of goat diseases followed by winter season (82.85%) and summer season (82.44%). PPR was significantly (p<0.05) more prevalent in winter season than other two seasons. In this study, Goats had significantly higher (p<0.01) prevalence of worm infestation in the summer season (29.00%) and the rainy season (39.35%) and in all three (0-12 months, 13-24 months and >24 months) age groups with 21.64%, 45.06%, and 32.20% respectively. Prevalence of mastitis was lowest in 0-12 months (0.43%) and 13-24 months (0.62%) age group but the prevalence of tetanus was lowest in above 24 months (1.69%) age group.These findings will help to know about age-wise and season wise variation of different diseases of goat in this area and will help to execute proper preventive measures against those diseases.
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