Уточнить поиск
Результаты 1-10 из 11
Comparing effects of freezing at -196 °C and -20 °C on the viability of mastitis pathogens
2012
Inge-Marie Petzer | Joanne Karzis | Theodorus J. van der Schans | Johanna C. Watermeyer | Norman Mitchell-Innes | Stephanie Eloff | Geoffrey T. Fosgate
The aim of this study was to compare the effects of cryopreservation at approximately -196 °C in liquid nitrogen (N) and freezing at approximately -20 °C in a freezer, on the viability and survival of eight different mastitogenic bacteria inoculated in milk. Bacteria were frozen at approximately -20 °C in a freezer and cryopreserved at approximately -196 °C in liquid nitrogen. An effective preservation method was needed for follow-up samples from cows identified in the South African National Milk Recording Scheme (NMRS) with somatic cell counts above 250 000 cells/mL milk. The organisation responsible for sample collection of the NMRS milk samples also provides producers with liquid nitrogen for their semen flasks at the collection sites. This existing mode of storage and transport could therefore be utilised.Ten samples of each organism were thawed and cultured bi-weekly until week 18 for both temperature treatments. An additional sampling was performed at week 30 for samples frozen at approximately -20 °C. Freezing and cryopreservation did not impair subsequent isolation of Streptococcus dysgalactiae, Streptococcus uberis, Enterococcus faecalis, Staphylococcus aureus (STH) (phage type lytic group III) or Sta. aureus (STA) (phage typed, other than lytic group III). Survival was indicated by the isolation of bacteria from samples, and viability by the strength of growth of the bacteria isolated. The survival of Streptococcus agalactiae decreased after week 12 and Escherichia coli after week 16 of freezing, but both organisms survived under cryogenic preservation until week 18. Coagulase-negative staphylococci survived until week 18 for both freezing and cryogenic preservation.Both storage methods could thus contribute to the improvement of a pro-active approach towards udder health management in South African dairy herds.
Показать больше [+] Меньше [-]Detection of heartworm infection in dogs via PCR amplification and electrospray ionization mass spectrometry of nucleic acid extracts from whole blood samples
2012
Crowder, Christopher D. | Matthews, Heather E. | Rounds, Megan A. | Li, Feng | Schutzer, Steven E. | Sampath, Ranga | Hofstadler, Steven A. | Ecker, David J. | Eshoo, Mark W.
Objective: To develop and evaluate a rapid and accurate assay involving PCR amplification and electrospray ionization mass spectrometry of nucleic acid extracts from whole blood samples for the detection of Dirofilaria immitis infection in dogs. Sample: Whole blood nucleic acid extracts from 29 dogs experimentally infected with D immitis (and in which circulating D immitis antigen was detected) and 10 uninfected dogs. Procedures: 16 of the 29 whole blood samples from infected dogs were examined at the time of collection for circulating microfilaria. Nucleic acids were extracted from all whole blood specimens and underwent PCR amplification with 12 PCR primer pairs designed to detect a wide range of pathogens (including the Wolbachia endosymbiont of D immitis) and electrospray ionization mass spectrometry. Results: On the basis of assay results, heartworm infection was detected in 13 of 13 antigen-positive dogs of unknown microfilaria status, 11 of 11 antigen-positive dogs with circulating microfilaria, 0 of 3 antigen-positive dogs tested at 3 months after larval infection, 0 of 2 antigen-positive dogs with occult infections, and 0 of 10 uninfected dogs. Conclusions and Clinical Relevance: With the assay under investigation, it was possible to identify D immitis infection in dogs with circulating microfilaria via detection of the obligate Wolbachia endosymbiont of D immitis. It was not possible to identify dogs with occult infections, which suggested that circulating microfilaria must be present to detect infection with this assay, although further studies would be required to verify that finding.
Показать больше [+] Меньше [-]Pharmacokinetics of a long-acting ceftiofur crystalline-free acid formulation in Asian elephants (Elephas maxim us)
2012
Adkesson, Michael J. | Junge, Randall E. | Allender, Matthew C. | Martiin-Jimenez, Tomas
Objective: To determine the pharmacokinetics of a long-acting formulation of ceftiofur, ceftiofur crystalline-free acid (CCFA), following SC injection to Asian elephants (Elephas maxim us). Animals: 11 adult Asian elephants. Procedures: Each elephant received CCFA (6.6 mg/kg, SC) in the area caudoventral to the base of an ear. Blood samples were collected from an ear vein immediately prior to and at 0.5, 1, 2, 4, 8, 12, 24, 36, 48, 72, 96, 120, 144, and 168 hours after CCFA administration. Plasma concentrations of desfuroylceftiofur acetamide (the acetamide derivative of ceftiofur) were measured via ultrahigh-pressure liquid chromatography–tandem mass spectrometry. Data were analyzed via a noncompartmental pharmacokinetics approach. Results: The mean ± SD maximum plasma concentration of desfuroylceftiofur acetamide was 1.36 ± 0.74 μg/mL and was detected at 4718 ± 31.30 hours. The mean ± SD area under the curve from time 0 to infinity was 2278 ± 55.8 μg•h/mL, and the mean residence time from time 0 to infinity was 158.2 ± 90.2 hours. The terminal elimination half-life associated with the slope of the terminal phase had a harmonic mean ± pseudo-SD of 83.36 ± 30.01 hours. Conclusions and Clinical Relevance: Elephants tolerated CCFA at a dose of 6.6 mg/kg, SC, well. Dosing recommendations will depend on the mean inhibitory concentration of ceftiofur for each bacterial pathogen. Desfuroylceftiofur acetamide concentrations remained > 0.25 μg/mL for the entire 168-hour study period, which suggested CCFA would provide clinically relevant antimicrobial activity against certain pathogens for 7 to 10 days.
Показать больше [+] Меньше [-]Tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders
2012
López Cadenas, Cristina | Fernández Martínez, Nelida | Sierra Vega, Matilde | Diez Liébana, Maria J. | Gonzalo Orden, Jose M. | Sahagún Prieto, Ana M. | García Vieitez, Juan J.
Objective: To determine the tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders by measuring its concentration at various sample collection sites. Sample: 26 udders (obtained following euthanasia) from 26 healthy lactating sheep. Procedures: For each isolated udder, 1 mammary gland was perfused with warmed, gassed Tyrode solution. Enrofloxacin (1 g of enrofloxacin/5 g of ointment) was administered into the perfused gland via the intramammary route or systemically via the perfusion fluid (equivalent to a dose of 5 mg/kg). Samples of the perfusate were obtained every 30 minutes for 180 minutes; glandular tissue samples were obtained at 2, 4, 6, and 8 cm from the teat base after 180 minutes. The enrofloxacin content of the perfusate and tissue samples was analyzed via high-performance liquid chromatography with UV detection. Results: After intramammary administration, maximun perfusate enrofloxacin concentration was detected at 180 minutes and, at this time, mean tissue enrofloxacin concentration was detected and mean tissue enrofloxacin concentration was 123.80, 54.48, 36.72, and 26.42 μg/g of tissue at 2, 4, 6, and 8 cm from the teat base, respectively. Following systemic administration, perfusate enrofloxacin concentration decreased with time and, at 180 minutes, tissue enrofloxacin concentrations ranged from 40.38 to 35.58 μg/g of tissue. Conclusions and Clinical Relevance: By 180 minutes after administration via the intramammary or systemic route in isolated perfused sheep mammary glands, mean tissue concentration of enrofloxacin was greater than the minimum inhibitory concentration required to inhibit growth of 90% of many common mastitis pathogens in sheep. Use of either route of administration (or in combination) appears suitable for the treatment of acute mastitis in sheep.
Показать больше [+] Меньше [-]Perinuclear antineutrophil cytoplasmic autoantibodies in dogs infected with various vector-borne pathogens and in dogs with immune-mediated hemolytic anemia
2012
Objective: To determine the prevalence of perinuclear antineutrophil cytoplasmic autoantibodies (pANCA) in dogs with confirmed or suspected immune-mediated hemolytic anemia (IMHA) or dogs infected with various vector-borne pathogens, including Rickettsia rickettsii, Bartonella henselae, Bartonella vinsonii subsp berkhoffii, Ehrlichia canis, Borrelia burgdorferi, and Leishmania infantum. Animals: 55 dogs with confirmed or suspected IMHA, 140 dogs seroreactive for vector-borne pathogens, and 62 healthy dogs and dogs seronegative for vector-borne pathogens. Procedures: Samples were allocated to subgroups on the basis of the health status of the dogs and the degree of seroreactivity against various vector-borne pathogens. Serum samples were tested retrospectively via indirect immunofluorescence assay to determine pANCA status. Results: 26 of 55 (47%) dogs with confirmed or suspected IMHA and 67 of 140 (48%) dogs seroreactive for vector-borne pathogens had positive results when tested for pANCA. Serum samples with the highest antibody concentrations against L infantum antigen had the highest proportion (28/43 [65%]) that were positive for pANCA. One of 20 (5%) dogs seronegative for tick-borne pathogens and 8 of 22 (36%) dogs seronegative for L infantum had positive results for pANCA. One of 20 (5%) healthy dogs had serum antibodies against pANCA. Conclusions and Clinical Relevance: pANCA were detected in a high percentage of dogs with IMHA and vector-borne infectious diseases. Therefore, pANCA may be a relatively nonspecific marker for dogs with inflammatory bowel disease, although they could represent a biomarker for immune-mediated diseases and infections.
Показать больше [+] Меньше [-]Glycohistochemical characterization of histologically normal nasal mucosa and enzootic nasal tumor of sheep
2012
Scocco, Paola | Lepri, Elvio | Mercati, Francesca | Vitellozzi, Giovanni | Mechelli, Luca | Ceccarelli, Piero
Objective: To determine glycohistochemical characteristics of enzootic nasal tumors (ENTs) of sheep, compare results for ENT with those of histologically normal nasal mucosa of sheep, and identify the histologic origin of ENT. Sample: ENT and nasal mucosa samples obtained from cadavers of 5 adult Lacaune sheep with ENT and 5 Lacaune sheep unaffected by ENT, respectively. Procedures: Samples of ENT and nasal mucosa were collected from cadavers of sheep and sectioned. Conventional and lectin histochemical analyses were used to identify glycoconjugates in tissue sections on the basis of their principal chemical groups and principal terminal or internal oligosaccharidic glucidic residues, respectively. Results: ENTs had papillary and tubular portions. Cells in the papillary portion of ENTs had secretion and surface glycoconjugates, which included sulfated glycosaminoglycans and neutral and sialilated glycoproteins. Cells in the tubular portion of ENTs had surface glycoconjugates, which included neutral and sialilated glycoproteins. Both portions of ENTs had C4-acetylated sialoderivatives that were not detected in sections of histologically normal nasal mucosa. Conclusions and Clinical Relevance: The papillary portion of ENTs in sheep may originate from respiratory glands and goblet cells. The tubular portion of ENTs in sheep may originate from olfactory glands. Presence of C4-acetylated sialoderivatives in cells of ENTs could confer resistance against pathogens to those cells.
Показать больше [+] Меньше [-]Optimized protocol for multiplex nested polymerase chain reaction to detect and differentiate Haemophilus parasuis, Streptococcus suis, and Mycoplasma hyorhinis in formalin-fixed, paraffin-embedded tissues from pigs with polyserositis
2012
Kang, Ikjae | Kim, Duyeol | Han, Kiwon | Seo, Hwi Won | Oh, Yeonsu | Park, Changhoon | Lee, Jeehoon | Gottschalk, Marcelo | Chae, Chanhee
An optimized protocol was developed for the simultaneous detection and differentiation of Haemophilus parasuis, Streptococcus suis, and Mycoplasma hyorhinis in formalin-fixed, paraffin-embedded (FFPE) tissues with multiplex nested polymerase chain reaction (PCR). This method also determines the prevalence of these bacteria in pigs with polyserositis. DNA extraction with a combination of a commercial reagent and proteinase K resulted in more frequent detection of the pathogens than DNA extraction with proteinase K alone. Among FFPE tissue samples from 312 cases of polyserositis in which at least 1 bacterial species was detected, multiplex nested PCR detected H. parasuis in 239 (77%), S. suis in 124 (40%), and M. hyorhinis in 40 (13%). The disease was caused by a single pathogen in 224 (72%) of the cases and multiple pathogens in 88 (28%). Among the pigs positive for H. parasuis, S. suis, and M. hyorhinis by multiplex nested PCR, the pathogen was isolated from only 11%, 35%, and 28%, respectively. Therefore, the PCR protocol developed in this study is a useful diagnostic method when samples are negative after isolation methods and even for samples in which only 1 pathogen was isolated.
Показать больше [+] Меньше [-]Pharmacokinetics of a single intramuscular injection of ceftiofur crystalline-free acid in American black ducks (Anas rubripes)
2012
Hope, Katharine L. | Tell, Lisa A. | Byrne, Barbara A. | Murray, Suzan | Wetzlich, Scott E. | Ware, Lisa H. | Lynch, Warren | Padilla, Luis R. | Boedeker, Nancy C.
Objective: To determine the pharmacokinetic properties of 1 IM injection of ceftiofur crystalline-free acid (CCFA) in American black ducks (Anas rubripes). Animals: 20 adult American black ducks (6 in a preliminary experiment and 14 in a primary experiment). Procedures: Dose and route of administration of CCFA for the primary experiment were determined in a preliminary experiment. In the primary experiment, CCFA (10 mg/kg, IM) was administered to ducks. Ducks were allocated into 2 groups, and blood samples were obtained 0.25, 0.5, 1, 2, 4, 8, 12, 48, 96, 144, 192, and 240 hours or 0.25, 0.5, 1, 2, 4, 8, 24, 72, 120, 168, and 216 hours after administration of CCFA. Plasma concentrations of ceftiofur free acid equivalents (CFAEs) were determined by use of high-performance liquid chromatography. Data were evaluated by use of a naive pooled-data approach. Results: The area under the plasma concentration versus time curve from 0 hours to infinity was 783 h•μg/mL, maximum plasma concentration observed was 13.1 μg/mL, time to maximum plasma concentration observed was 24 hours, terminal phase half-life was 32.0 hours, time that concentrations of CFAEs were higher than the minimum inhibitory concentration (1.0 μg/mL) for many pathogens of birds was 123 hours, and time that concentrations of CFAEs were higher than the target plasma concentration (4.0 μg/mL) was 73.3 hours. Conclusions and Clinical Relevance: On the basis of the time that CFAE concentrations were higher than the target plasma concentration, a dosing interval of 3 days can be recommended for future multidose CCFA studies.
Показать больше [+] Меньше [-]Occurrence of Rhodococcus equi in soil and faeces in selected stud farms in Malaysia
2012
M. Fhitri | Zunita Z. | Latiffah H. | Noordin M.M.
The world widely distributed infection by Rhodococcus equi usually leads to pneumonia and associated respiratory signs. This study is aimed at detecting the occurrence of this pathogen in selected horse farms. A total of 12 R. equi isolates from few samples (13.89%) were successfully obtained from soil and faeces collected from two selected farms. However, based on the vapA gene classification, only one virulent R. equi isolate was identified.
Показать больше [+] Меньше [-]Neonatal diarrhoea in goat kids
2012
Noor Suhaila Samsi | Azizah Darus | Zamila Zainun