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1.
Background
The mutant prevention concentration (MPC) is an important parameter to evaluate the likelihood of growth of fluoroquinolone-resistant mutants for antimicrobial-pathogen combinations. The MPCs of fluoroquinolones for different canine pathogens have not been compared. In this study, we compared for the first time orbifloxacin MPCs between susceptible strains of Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius of canine origin.Methods
More than 1010 CFU/ml of 10 strains of each bacterial species were inoculated onto Muller-Hinton agar supplemented with different concentrations of orbifloxacin from 1× to 64× minimum inhibitory concentration (MIC) and the MPCs were recorded. MICs of original strains and of mutants arising after exposure to sub-MPC concentrations (one per original strain) were determined in the presence or absence of efflux pump inhibitors (EPIs). The effects of quinolone resistance-determining region (QRDR) mutations were also examined.Results
MPCs were significantly higher for P. aeruginosa (16–128 μg/ml) than for E. coli (0.5–32 μg/ml). MPCs for S. pseudintermedius varied between the low-susceptible (16–128 μg/ml) and the high-susceptible strains (4–16 μg/ml) and were the most broadly distributed among the three species. Regarding resistance mechanisms, only one QRDR mutation in gyrA was found in all of the 10 mutants of E. coli and in 4 of the 10 mutants of P. aeruginosa, whereas mutations in both grlA and gyrA were found in 3 mutants and one mutation in grlA was found in 2 mutants among the 10 mutants of S. pseudintermedius. In the presence of an EPI, the MICs of P. aeruginosa mutants decreased markedly, those of E. coli mutants decreased moderately, and those of S. pseudintermedius mutants were unaffected.Conclusions
MPCs of orbifloxacin vary between bacterial species of canine pathogens, possibly due to the diversity of the main fluoroquinolone resistance mechanism among these species. Therefore, the type of bacterial species should be taken into consideration when using fluoroquinolone drugs such as orbifloxacin in canines. 相似文献2.
Mohammed Ahmed UMAR Sho FUKUI Kodai KAWASE Takaharu ITAMI Kazuto YAMASHITA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):281-288
Cardiovascular effects of total intravenous anesthesia using
ketamine-medetomidine-propofol drug combination (KMP-TIVA) were determined in 5
Thoroughbred horses undergoing surgery. The horses were anesthetized with intravenous
administration (IV) of ketamine (2.5 mg/kg) and midazolam (0.04 mg/kg) following
premedication with medetomidne (5 µg/kg, IV) and artificially ventilated.
Surgical anesthesia was maintained by controlling propofol infusion rate (initially 0.20
mg/kg/min following an IV loading dose of 0.5
mg/kg) and constant rate infusions of ketamine (1 mg/kg/hr) and medetomidine
(1.25 µg/kg/hr). The horses were anesthetized for 175 ± 14 min (range
from 160 to 197 min). Propofol infusion rates ranged from 0.13 to 0.17 mg/kg/min, and
plasma concentration (Cpl) of propofol ranged from 11.4 to 13.3
µg/ml during surgery. Cardiovascular measurements
during surgery remained within clinically acceptable ranges in the horses (heart rate: 33
to 37 beats/min, mean arterial blood pressure: 111 to 119 mmHg, cardiac index: 48 to 53
ml/kg/min, stroke volume: 650 to 800 ml/beat and
systemic vascular resistance: 311 to 398 dynes/sec/cm5). The propofol Cpl
declined rapidly after the cessation of propofol infusion and was significantly lower at
10 min (4.5 ± 1.5 µg/ml), extubation (4.0 ± 1.2
µg/ml) and standing (2.4 ± 0.9
µg/ml) compared with the Cpl
at the end of propofol administration (11.4 ± 2.7
µg/ml). All the horses recovered uneventfully and stood
at 74 ± 28 min after the cessation of anesthesia. KMP-TIVA provided satisfactory quality
and control of anesthesia with minimum cardiovascular depression in horses undergoing
surgery. 相似文献
3.
Kazuki HARADA Atsushi SASAKI Takae SHIMIZU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):83-89
The study objective was to determine the effect of oral orbifloxacin (ORB) on
antimicrobial susceptibility and composition of fecal coliforms in cats. Nine cats were
randomized to two groups administered a daily oral dose of 2.5 and 5.0 mg ORB/kg for 7
days and a control group (three cats per group). Coliforms were isolated from stool
samples and were tested for susceptibilities to ORB and 5 other drugs. ORB concentration
in feces was measured using high-performance liquid chromatography (HPLC). The coliforms
were undetectable after 2 days of ORB administration, and their number increased in most
cats after termination of the administration. Furthermore, only isolates of
Escherichia coli were detected in all cats before administration, and
those of Citrobacter freundii were detected after termination of the
administration. E. coli isolates exhibited high ORB susceptibility
[Minimum inhibitory concentration (MIC), ≤0.125 µg/ml]
or relatively low susceptibility (MIC, 1−2 µg/ml) with a
single gyrA mutation. C. freundii isolates largely
exhibited intermediate ORB susceptibility (MIC, 4
µg/ml), in addition to resistance to ampicillin and
cefazolin, and harbored qnrB, but not a gyrA mutation.
HPLC revealed that the peaks of mean concentration were 61.3 and 141.0
µg/g in groups receiving 2.5 and 5.0 mg/kg, respectively. Our findings
suggest that oral ORB may alter the total counts and composition of fecal coliform, but is
unlikely to yield highly fluoroquinolone-resistant mutants of E. coli and
C. freundii in cats, possibly because of the high drug concentration in
feces. 相似文献
4.
Sileshi BELEW Jin-Yoon KIM Md.Akil HOSSAIN Ji-Yong PARK Seung-Jin LEE Yong-Soo PARK Joo-Won SUH Jong-Choon KIM Seung-Chun PARK 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):327-329
Pharmacokinetic (PK) parameters of marbofloxacin (MRFX) in Korean cattle, Hanwoo, were
determined following its intravenous (i.v.) or intramuscular (i.m.) administration at a
dose of 2 mg/kg. Area under the curve (AUC0–24 hr), half-life (t1/2)
and total body clearance (CLB) of i.v. MRFX were 6.87
hr∙µg/ml, 2.44 hr and 0.29 l/kg∙hr,
respectively, and the corresponding values for i.m. administration of MRFX were 5.07
hr∙µg/ml, 2.44 hr and 0.39 l/kg∙hr.
The suggested optimal doses of MRFX in Hanwoo cattle, calculated by integration of PK data
obtained in the present study and previously reported minimum inhibitory concentration
(MIC) for MRFX against susceptible (MIC ≤1 µg/ml) and
intermediate (MIC ≤2 µg/ml) pathogenic bacteria, were
2.1 and 4.2 mg/kg/day by i.v. route and 3.9 and 7.8 mg/kg/day by i.m. route. 相似文献
5.
The mutant prevention concentration (MPC) is a new concept meant to face the increased prevalence of antibiotic resistance by using antibiotic concentrations able to prevent the selection of single-step resistant mutants. In the present study, the MPCs of ciprofloxacin and enrofloxacin were evaluated against fully susceptible strains of Escherichia coli, Salmonella Typhimurium and Pseudomonas aeruginosa. Additionally, representative single-step mutants arising after exposure to sub-MPC antibiotic concentrations were investigated for molecular basis of their fluoroquinolone resistance phenotypes. MPC value was recorded when more than 1010 CFU/mL were spread on Muëller Hinton Agar supplemented with different antibiotic concentrations (from 1X to 16X MIC value). MICs of original strains as well as single-step mutants were determined in presence or absence of the Efflux Pump Inhibitor Phe-Arg-β-naphthylamide (PAβN). Moreover point mutations in the QRDR of the gyrA and parC genes were investigated by sequencing. The enrofloxacin MPC values were 4–16-fold higher than ciprofloxacin values. E. coli and S. Typhimurium representative single-step mutants showed reduced susceptibilities associated with point mutations in the QRDR of the gyrA gene or efflux pump system. P. aeruginosa mutants showed resistance phenotypes associated predominantly with efflux pump system activity. According to in vitro MPC data, ciprofloxacin showed a better efficacy than enrofloxacin, in preventing the selection of E. coli, S. Typhimurium and P. aeruginosa single-step mutants. However, in relation to AUC/MPC ratio, the MPC concept can be applied in vivo to ciprofloxacin and enrofloxacin for E. coli and S. Typhimurium but not for P. aeruginosa. 相似文献
6.
M. Shamim Hasan ZAHID Sharda Prasad AWASTHI Atsushi HINENOYA Shinji YAMASAKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(5):535-540
To search natural compounds having inhibitory effect on bacterial growth is important,
particularly in view of growing multidrug resistant (MDR) strains of bacterial pathogens.
Like other bacterial pathogens, MDR Vibrio cholerae, the causative agent
of diarrheal disease cholera, is becoming a great concern. As an approach of searching new
antimicrobial agents, here, we show that anethole, a well-studied natural component of
sweet fennel and star anise seeds, could potentially inhibit the growth of MDR O1 El Tor
biotype, the ongoing 7th cholera pandemic variant strains of toxigenic V.
cholerae. The minimum inhibitory concentration (MIC) of anethole against
diverse O1 El Tor biotype strains is evaluated as 200
µg/ml. Moreover, the effect of anethole is
bactericidal and exerts rapid-killing action on V.
cholerae cells. This study is the first report which demonstrates
that anethole, purified from natural compound, is a potent inhibitor of growth of
toxigenic V. cholerae. Our data suggest that anethole could be a
potential antimicrobial drug candidate, particularly against MDR V.
cholerae mediated infections. 相似文献
7.
Tsukasa OKANO Katsuhi NAKATA Yumiko NAKAYA Takashi NAGAMINE Manabu ONUMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):637-642
The Ryukyu long-furred rat, Diplothrix legata, is a large rodent
distributed only on Amami-ohshima Island, Tokuno-shima Island and Okinawa-jima Island,
Japan. This animal is endangered as a result of deforestation, predation by introduced
carnivores and mortality caused by vehicles. We performed theriogenological examinations
of 32 male and 25 female Ryukyu long-furred rats carcasses collected from wild populations
on northern Okinawa-jima Island from December 2005 to September 2013. Adult males had
remarkably large preputial glands. Seminiferous diameter of adult was significantly small
(136 ± 28 µm, n=8) from April to August. Numerous spermatozoa were
observed from September through February, and seminiferous diameter was significantly
large (216 ± 27 µm, n=12) during this time in adults; testes length
changed in a similar pattern. These findings indicate that the mating season may occur
from September through February. Size (body length) at sexual maturity was estimated to be
>560 mm in both sexes. From observation of corpora lutea and placental scars, litter
size was estimated to range from 2 to 12 (average=6, n=4). These results provide
fundamental knowledge that will be beneficial for in situ and ex
situ conservation of this rare species. 相似文献
8.
M?rit Pringle Annica Landén Helle Ericsson Unnerstad Benedicta Molander Bj?rn Bengtsson 《Acta veterinaria Scandinavica》2012,54(1):54
Background
The anaerobic spirochetes Brachyspira hyodysenteriae and Brachyspira pilosicoli cause diarrheal diseases in pigs. Their fastidious nature has hampered standardization of methods for antimicrobial susceptibility testing. For monitoring of antimicrobial susceptibility wild type cutoff values are needed to define where the wild type distribution of MICs ends and no approved cutoffs are available for Brachyspira spp. In this study antimicrobial susceptibility data for both species (in total 906 isolates) were compiled and analyzed and wild type cut off values for B. hyodysenteriae proposed.Methods
The MICs of tiamulin, valnemulin, tylosin, tylvalosin, doxycycline and lincomycin were determined by broth dilution in brain heart infusion broth supplemented with 10% fetal calf serum.Results
The compiled MICs from the broth dilution tests of the B. hyodysenteriae type strain, B78T (ATCC® 27164T), showed that the method yields reproducible results. In an international perspective the frequencies of isolates with decreased antimicrobial susceptibility were low among both B. hyodysenteriae and B. pilosicoli. However, in B. pilosicoli a constant level of 10-15% isolates with tiamulin MICs >4 μg/ml was detected between 2002 and 2010 and in B. hyodysenteriae a gradual increase in tiamulin MICs was seen between 1990 and 2003 although this increase has ceased during the last years. The wild type cutoff values proposed for B. hyodysenteriae are: tiamulin >0.25 μg/ml, valnemulin >0.125 μg/ml, tylosin >16 μg/ml, tylvalosin >1 μg/ml, lincomycin >1 μg/ml and doxycycline >0.5 μg/ml.Conclusions
The broth dilution method used in this study has over the years generated tightly grouped MIC populations for the field isolates and reproducible results for the control strain B78T and is therefore a suitable antimicrobial susceptibility test method for monitoring of Brachyspira spp. Here we propose wild type cutoff values for six antimicrobial agents for B. hyodysenteriae tested by broth dilution based on MIC distributions and the current knowledge on mechanisms of resistance in this species. There are few studies on antimicrobial resistance mechanisms and MIC distributions in B. pilosicoli but to some extent the cutoff values proposed for B. hyodysenteriae may be applicable also for monitoring of antimicrobial susceptibility in B. pilosicoli. 相似文献9.
Mitsuhide NAKAGAWA Kenji TSUKANO Yoshiki MURAKAMI Marina OTSUKA Kazuyuki SUZUKI Hiroetsu SUZUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2020,82(11):1585
The aim of this study was to examine whether 2.16% hypertonic saline solution (HSS) is useful for the treatment of diarrheic calves with hyponatremia. Eleven of 13 female Holstein calves exhibiting moderate diarrhea and hyponatremia received 1,250 ml of 2.16% HSS over 15 min regardless of body weight. The remaining two calves that were unable to stand and had severe hyponatremia received 2,500 ml of 2.16% HSS intravenously over 30 min. As a result, hyponatremia in all diarrheic calves was significantly improved by the administration of 2.16% HSS from 122.2 ± 7.0 mEq/l at pre to 134.8 ± 3.7 mEq/l at post, which was above the threshold of 132 mEq/l for hyponatremia. Therefore, 2.16% HSS may be useful for hyponatremia in calves with diarrhea. 相似文献
10.
Narong TIPTANAVATTANA Araya RADTANAKATIKANON Poul HYTTEL Hanne HOLM Supranee BURANAPRADITKUN Piyathip SETTHAWONG Mongkol TECHAKUMPHU Theerawat THARASANIT 《The Journal of reproduction and development》2015,61(6):581-588
The development of germ cells has not been entirely documented in the cat especially the transition phase of
the gonocyte to the spermatogonial stem cell (G/SSC). The aims of study were to examine testicular development
and to identify the G/SSC transition in order to isolate and culture SSCs in vitro. Testes
were divided into 3 groups according to donor age (I, < 4 months; II, 4–6 months; and III, > 6 months).
In Exp. 1, we studied testicular development by histology, transmission electron microscopy and
immunohistochemistry. In Exp. 2, we determined the expression of GFRα-1, DDX-4 and c-kit and performed flow
cytometry. The SSCs isolated from groups II and III were characterized by RT-PCR and TEM (Exp. 3).
Chronological changes in the G/SSC transition were demonstrated. The size, morphology and ultrastructure of
SSCs were distinguishable from those of gonocytes. The results demonstrated that group II contained the
highest numbers of SSCs per seminiferous cord/tubule (17.66 ± 2.20%) and GFRα-1+ cells (14.89 ±
5.66%) compared with the other groups. The findings coincided with an increased efficiency of SSC derivation
in group II compared with group III (74.33 ± 2.64% vs. 23.33 ± 2.23%). The colonies expressed
mRNA for GFRA1, ZBTB16, RET and POU5F1.
Our study found that the G/SSC transition occurs at 4–6 months of age. This period is useful for isolation and
improves the establishment efficiency of cat SSCs in vitro. 相似文献
11.
Toshiho NISHITA Ryou ANEZAKI Kazunori MATSUNAGA Kensuke ORITO Tamae KASUYA Hideyo SAKANOUE Akiko MATSUNAGA Kazuyoshi ARISHIMA 《Journal of Equine Science》2013,24(4):57-62
Although endoscopy is the definitive diagnostic method for the detection of colonic
ulcers, the equipment required for performing the test is costly and difficult to use.
Therefore, a simple cost-effective and reliable screening test for intestinal tract
bleeding is needed. To this end, we measured carbonic anhydrase isozymes (CA-I and CA-II)
originating from erythrocytes by ELISA in order to determine if they could be used as
markers of occult blood in feces. For fecal extract preparation, 2 g of feces were mixed
with 4 ml of 0.01 M Tris-HCl (pH 8.0) containing 0.01% thimerosal. The concentrations of
CA-I and CA-II in the fecal samples of 13 clinically normal racehorses were found to be
30.0 ± 10.0 and 34.0 ± 13.0 ng/ml, respectively. Increased concentrations of CA-I were
detected in the fecal samples of 5 horses after blood administration; however, no increase
was observed in CA-II. The concentrations of CA-I and CA-II in the fecal samples of 88
racehorses with clinical signs of equine gastric ulcer syndrome (EGUS) were 115.3 ± 79.0
and 41.0 ± 42.0 ng/ml, respectively. Thus, our results indicate that CA isozymes can be
useful as markers of occult blood in the fecal samples of horses with intestinal tract
bleeding. 相似文献
12.
Fumie MAGATA Yoshikazu ISHIDA Akio MIYAMOTO Hidefumi FURUOKA Hisashi INOKUMA Takashi SHIMIZU 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(1):81-84
We investigated the
concentration of the bacterial endotoxin lipopolysaccharide (LPS) in the blood, ovarian
follicular fluid and uterine fluid of a clinical case of bovine metritis. A 2-year-old
lactating Holstein cow exhibited continuous fever >39.5°C for more than 2 weeks after
normal calving. The cow produced a fetid, watery, red-brown uterine discharge from the
vagina and was diagnosed with metritis. The LPS concentrations in plasma and uterine fluid
were 0.94 and 6.34 endotoxin units (EU)/ml, respectively. One of seven
follicles showed an extremely high level of LPS (12.40 EU/ml) compared to
the other follicles (0.62–0.97 EU/ml). These results might suggest the
presence of high concentration of LPS in follicles in cows with postpartum metritis. 相似文献
13.
Doo Kim Dorsey Kordick Thomas Divers Yung-Fu Chang 《Journal of veterinary science (Suw?n-si, Korea)》2006,7(4):355-359
Antimicrobial susceptibility testing was conducted with 6 different spirochetal strains (4 strains of Leptospira spp. and 2 strains of Borrelia burgdorferi) against 3 antimicrobial agents, commonly used in equine and bovine practice. The ranges of MIC and MBC of amoxicillin against Leptospira spp. were 0.05-6.25 µg/ml and 6.25-25.0 µg/ml, respectively. And the ranges of minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of amoxicillin against B. burgdorferi were 0.05-0.39 µg/ml and 0.20-0.78 µg/ml, respectively. The ranges of MIC and MBC of enrofloxacin against Leptospira spp. were 0.05-0.39 µg/ml and 0.05-0.39 µg/ml, respectively. Two strains of B. burgdorferi were resistant to enrofloxacin at the highest concentration tested for MBC (≥100 µg/ml). Therefore, the potential role of tilmicosin in the treatment of leptospirosis and borreliosis should be further evaluated in animal models to understand whether the in vivo studies will confirm in vitro results. All spirochetal isolates were inhibited (MIC) and were killed (MBC) by tilmicosin at concentrations below the limit of testing (≤0.01 µg/ml). 相似文献
14.
Yoshiro ENDO Seiji HOBO Kenji KOROSUE Kenji OOTSUKA Akira KITAUCHI Risa KIKKAWA Yuichi HIDAKA Mitsuyoshi HAGIO Nao TSUZUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(4):507-509
The present study evaluated the effects of single-dose filgrastim on hematology in 16
healthy horses after long-distance transportation. Horses were assigned to receive
filgrastim (0.23 µg/kg, SC, once; G-CSF group; n=8) or saline (0.9% NaCl)
solution (0.3 ml, SC, once; control group; n=8) ≤ 1 hr before
transportation. Horses were transported 2,530 km using commercial vans over the course of
approximately 44 hr. Clinical examinations and hematologic analyses were performed on all
horses before and after transportation. Because the post-transportation white blood cell
counts and bacillary neutrophil to segmented neutrophil ratio were significantly higher in
the G-CSF group, filgrastim may have promoted the mobilization of neutrophils from marrow.
Filgrastim deserves a further study for efficacy in preventing horse shipping fever. 相似文献
15.
Ji Hyung Kim Sun Young Hwang Jee Soo Son Jee Eun Han Jin Woo Jun Sang Phil Shin Casiano Choresca Jr Yun Jaie Choi Yong Ho Park Se Chang Park 《Journal of veterinary science (Suw?n-si, Korea)》2011,12(1):41-48
The antibiotic resistance of 16 Aeromonas (A.) salmonicida strains isolated from diseased fish and environmental samples in Korea from 2006 to 2009 were investigated in this study. Tetracycline or quinolone resistance was observed in eight and 16 of the isolates, respectively, based on the measured minimal inhibitory concentrations. Among the tetracycline-resistant strains, seven of the isolates harbored tetA gene and one isolate harbored tetE gene. Additionally, quinolone-resistance determining regions (QRDRs) consisting of the gyrA and parC genes were amplified and sequenced. Among the quinolone-resistant A. salmonicida strains, 15 harbored point mutations in the gyrA codon 83 which were responsible for the corresponding amino acid substitutions of Ser83→Arg83 or Ser83→Asn83. We detected no point mutations in other QRDRs, such as gyrA codons 87 and 92, and parC codons 80 and 84. Genetic similarity was assessed via pulsed-field gel electrophoresis, and the results indicated high clonality among the Korean antibiotic-resistant strains of A. salmonicida. 相似文献
16.
Supannika HANTRAKUL Narumol KLANGKAEW Sunee KUNAKORNSAWAT Tawewan TANSATIT Ammart POAPOLATHEP Susumu KUMAGAI Saranya POAPOLATHEP 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1549-1553
This study was conducted to evaluate the pharmacokinetic characteristics of vincristine
and their correlation with its clinical effects in dogs with transmissible venereal tumor
(TVT). Dogs with TVT were intravenously administered vincristine sulfate at a dose of 0.7
mg/m2 of body surface area. Blood samples were collected starting from 5 min
to 48 hr after drug administration. The plasma concentration of vincristine was determined
using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pharmacokinetic
parameters of vincristine were characterized using a two-compartmental pharmacokinetic
model. The volume of distribution, distribution half-life, elimination half-life and
plasma clearance were 0.660 ± 0.210 l/kg, 21.5 ± 6.90 min, 47.6 ± 14.2
min and 0.010 ± 0.001 l/min/kg, respectively. Tumor regression was
determined at weekly interval by a physical examination and histopathological analysis. In
our study, three to eight administrations of vincristine at a dose of 0.7 mg/m2
were able to induce a complete tumor regression without any evidence of gross lesion of
disease. Therefore, this investigation provides the pharmacokinetic characteristics of
vincristine in dogs with TVT, which may be used as an integration tool to gain a better
understanding of the disposition properties of the drug and the correlation of these
properties with the drug’s clinical effects. In addition, we validated the LC-MS/MS method
and found that it is suitable for the pharmacokinetic study of vincristine in dog
plasma. 相似文献
17.
The quinolone resistance-determining regions (QRDRs) of the gyrA gene of quinolone-resistant Salmonella enterica serovar Choleraesuis isolates were sequenced. Four types of point mutation, Ser-83-to-Phe (TCC→TTC), Ser-83-to-Tyr (TCC→TAC), Asp-87-to-Gly (GAC→GGC), and Asp-87-to-Asn (GAC→AAC), were found. PCR-RFLP and MAS-touch down PCR were performed on fifty swine clinical isolates of S. enterica serovar Choleraesuis (NalR) collected during 1997–2002. The analysis indicated seven isolates with point mutations in codon 83, 13 with point mutations in codon 87, and 30 with double mutations in both codons 83 and 87. The MICs of enrofloxacin of the isolates with a single mutation in codon 83 or 87 were <2 μg/ml, while the MICs of the isolates with double mutations in both codon 83 and 87 ranged from 2 to 64 μg/ml. A class I integron comprised of dhfr, orfF and aad2 was also identified in both human and swine S. enterica serovar Choleraesuis isolates. These results indicate that PCR-RFLP and MAS-touchdown PCR assays can be used for surveillance of gyrA gene mutations, which are important for fluoroquinolone resistance in Salmonella. Isolates with double mutations in gyrA codons 83 and 87 are the major type of quinolone-resistant Salmonella isolated from swine in Taiwan. A surveillance system may be applied to the swine industry to monitor the emergence of fluoroquinolone and/or multi-drug-resistant S. enterica serovar Choleraesuis in Taiwan. 相似文献
18.
Nobukazu SAISHU Kazutaka MORIMOTO Hiroshi YAMASATO Hiroichi OZAKI Toshiyuki MURASE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1037-1042
Thirty-eight Aerococcus viridans isolates were obtained from milk from
478 cows with clinical mastitis in a farm during the periods between November 2011 and
February 2012, and between December 2012 and March 2013. Additional isolates were obtained
from processed manure (a mixture of composted manure, straw and hydrated lime) and bedding
materials. The processed manure was later used to cover the floor of the stalls in barns
as bedding materials. The temperatures recorded in the composted and processed manure were
not as high as those generally observed during satisfactory composting. To reveal the
association of A. viridans in manure-related products with intramammary
infection in cows, isolates were characterized by their DNA fragment patterns as
determined by pulsed-field gel electrophoresis (PFGE) and antimicrobial susceptibility
testing. Isolates obtained from milk, processed manure and bedding materials had identical
DNA fragment patterns. Antimicrobial susceptibilities were determined for 29 isolates from
milk, processed manure and bedding materials. Of these, 26 (89.7%) were resistant to
clindamycin, whereas virtually all the isolates were susceptible to 12 other
antimicrobials including cefalosporins that have been used to treat bovine mastitis in
Japan. In vitro, three A. viridans isolates from milk
and an isolate from processed manure survived for 3 hr in Good’s buffer (pH 9) at high
temperature (50°C). The results suggest that the processed manure and bedding materials in
this farm were possible sources of A. viridans that caused infection in
the cows with mastitis. 相似文献
19.
Sasithorn PRALATNET Saranya POAPOLATHEP Kanjana IMSILP Phanwimol TANHAN Supaporn ISARIYODOM Susumu KUMAGAI Amnart POAPOLATHEP 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1151-1155
To evaluate the fate of deoxynivalenol (DON) in broilers, DON was administered either
intravenously or orally to broilers at a dose of 1 mg/kg BW. Concentrations of DON in
plasma were measurable up to 4 hr and 2 hr after intravenous and oral administration,
respectively. Following intravenous administration, the values for the elimination
half-life, the volume of distribution and the clearance were 1.25 ± 0.25 hr, 7.55 ± 2.03
l/kg and 4.16 ± 0.42 l/hr/kg, respectively. The oral
bioavailability was 15.46 ± 4.02%. DON was detectable in all tissues examined after oral
administration. These results suggest that DON is able to penetrate into the various
tissues in broilers, though poorly absorbed from their gastrointestinal tract. 相似文献
20.
M. Lanza‐Perea U. Zieger B.A. Qurollo B.C. Hegarty E.L. Pultorak S. Kumthekar R. Bruhl‐Day E.B. Breitschwerdt 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2014,28(6):1702-1707