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Melissa A. Miller Barbara A. Byrne Spencer S. Jang Erin M. Dodd Elene Dorfmeier Michael D. Harris Jack Ames David Paradies Karen Worcester David A. Jessup Woutrina A. Miller 《Veterinary research》2010,41(1)
Although protected for nearly a century, California’s sea otters have been slow to recover, in part due to exposure to fecally-associated protozoal pathogens like Toxoplasma gondii and Sarcocystis neurona. However, potential impacts from exposure to fecal bacteria have not been systematically explored. Using selective media, we examined feces from live and dead sea otters from California for specific enteric bacterial pathogens (Campylobacter, Salmonella, Clostridium perfringens, C. difficile and Escherichia coli O157:H7), and pathogens endemic to the marine environment (Vibrio cholerae, V. parahaemolyticus and Plesiomonas shigelloides). We evaluated statistical associations between detection of these pathogens in otter feces and demographic or environmental risk factors for otter exposure, and found that dead otters were more likely to test positive for C. perfringens, Campylobacter and V. parahaemolyticus than were live otters. Otters from more urbanized coastlines and areas with high freshwater runoff (near outflows of rivers or streams) were more likely to test positive for one or more of these bacterial pathogens. Other risk factors for bacterial detection in otters included male gender and fecal samples collected during the rainy season when surface runoff is maximal. Similar risk factors were reported in prior studies of pathogen exposure for California otters and their invertebrate prey, suggesting that land-sea transfer and/or facilitation of pathogen survival in degraded coastal marine habitat may be impacting sea otter recovery. Because otters and humans share many of the same foods, our findings may also have implications for human health. 相似文献
3.
Masanao MATAYOSHI Takashi KITANO Tetsu SASAKI Masaji NAKAMURA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):705-710
A total of 349 Salmonella enterica subspecies enterica
serovar Choleraesuis (S. Choleraesuis) strains, which were isolated
between 2008 and 2012 from 349 pigs at two slaughterhouses in Okinawa Prefecture, Japan,
were investigated for antimicrobial susceptibility and the presence of antimicrobial
resistance genes. All isolates were resistant to at least four antimicrobial agents. The
antimicrobial agents for which isolates showed a high incidence of resistance were as
follows: ampicillin (100%) and streptomycin (100%), followed by gentamicin (99.7%),
oxytetracycline (99.7%), sulfamethoxazole/trimethoprim (99.4%), nalidixic acid (40.1%) and
oxolinic acid (40.1%). All isolates were sensitive to cefuroxime, ceftiofur, colistin,
fosfomycin, enrofloxacin, orbifloxacin and danofloxacin. The predominant resistance
phenotypes and genotypes were: resistance to ampicillin, streptomycin, gentamicin,
oxytetracycline and sulfamethoxazole/trimethoprim (58.5%, 204/349) and
blaTEM-strA-strB-aadA1-aadA2-aacC2-tet
(B)-sul1-sul2-dhfrXII-dhfrXIII (36.1%, 126/349). The quinolone
resistance-determining regions (QRDRs) of gyrA, gyrB, parC and
parE of the quinolone-resistant isolates (n=12) showed amino acid
substitutions of Ser-83→Phe or Asp-87→Tyr in GyrA and Ser-107→Ala in ParC. To our
knowledge, this is the first report on the molecular characterization of antimicrobial
resistance among S. Choleraesuis strains in Japan. 相似文献
4.
Jin-A LEE Bock-Gie JUNG Tae-Hoon KIM Yun-Mi KIM Hong-Bum KOH Bong-Joo LEE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1087-1094
Biotite and bentonite are phyllosilicate minerals that were originally used in
industrial applications. Several beneficial activities of them have recently been
reported, especially regulation of the immune system and antimicrobial effects. Therefore,
we investigated the immune-enhancing and bacterial clearance effects of a biotite and
bentonite mixture (BBM) on experimental infection of Salmonella enterica
serovar Typhimurium (S. Typhimurium) to determine whether the BBM could
be used as an alternative antibiotic. We administered 1% or 2% BBM as a feed supplement.
We then evaluated the bacterial clearance effects of the BBM against S.
Typhimurium. We also evaluated the immune-enhancing effect of the BBM through several
immunological experiments that included examination of the lysozyme activity,
CD4+/CD8+ T lymphocyte ratio and the T-helper type 1 (Th 1)
cytokine profile. The clinical signs of S. Typhimurium and the number of
viable bacteria in feces and tissues were significantly decreased in both BBM groups,
especially in the 2% BBM group. The BBM also markedly enhanced the lysozyme activity,
CD4+/CD8+ T lymphocyte ratio and expression levels of IFN-γ and
IL-12 in S. Typhimurium-challenged pigs. Therefore, the BBM could be a
good candidate as an alternative antibiotic that improves Th 1-specific immune responses
and the bacterial clearance effect. 相似文献
5.
Ki-Eun LEE Deog-Yong LEE Hwan-Won CHOI Su-Jin CHAE Young-Sun YUN Ki-Chan LEE Yun-Sang CHO Dong-Kun YANG 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(11):1511-1515
Between 2011 and 2012, a total of 896 pig fecal samples were collected from nine
provinces in Korea, and 50 salmonella enterica susp.
enterica serovar Typhimurium (S. Typhimurium) was
isolated. The characteristics of the 50 strains were analyzed, and 4 strains were
identified as Salmonella enterica subsp. enterica
serovar 4,[5],12:i:-. Salmonella 4,[5],12:i:- could not be distinguished
from S. Typhimurium through phage typing, antimicrobial resistance
testing or multiple-locus variable-number tandem repeat analysis (MLVA). However, among
the four Salmonella 4,[5],12:i:- strains, one (KVCC-BA1400078) was
identified as a Salmonella 4,[5],12:i:- clone isolated from humans in the
United States, and another (KVCC-BA1400080) was identified as DT193, which has been
primarily isolated from humans and animals in European countries. The presence of
Salmonella 4,[5],12:i:- in Korea poses a significant threat of
horizontal transfer between pigs and humans. 相似文献
6.
Shao-Kuang CHANG Dan-Yuan LO Hen-Wei WEI Hung-Chih KUO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(1):59-65
This study determined the
antimicrobial resistance profiles of Escherichia coli isolates from dogs
with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 201 dogs
with UTI diagnosed through clinical examination and urinalysis were processed for
isolation of Escherichia coli. Colonies from pure cultures were
identified by biochemical reactions (n=114) and were tested for susceptibility to 18
antimicrobials. The two most frequent antimicrobials showing resistance in Urinary
E. coli isolates were oxytetracycline and ampicillin. Among the
resistant isolates, 17 resistance patterns were observed, with 12 patterns involving
multidrug resistance (MDR). Of the 69 tetracycline-resistant E. coli
isolates, tet(B) was the predominant resistance determinant and was
detected in 50.9% of the isolates, whereas the remaining 25.5% isolates carried the
tet(A) determinant. Most ampicillin and/or amoxicillin-resistant
E. coli isolates carried blaTEM-1 genes.
Class 1 integrons were prevalent (28.9%) and contained previously described gene cassettes
that are implicated primarily in resistance to aminoglycosides and trimethoprim
(dfrA1, dfrA17-aadA5). Of the 44 quinolone-resistant
E. coli isolates, 38 were resistant to nalidixic acid, and 6 were
resistant to nalidixic acid, ciprofloxacin and enrofloxacin. Chromosomal point mutations
were found in the GyrA (Ser83Leu) and ParC (Ser80Ile) genes. Furthermore, the
aminoglycoside resistance gene aacC2, the chloramphenicol resistant gene
cmlA and the florfenicol resistant gene floR were also
identified. This study revealed an alarming rate of antimicrobial resistance among
E. coli isolates from dogs with UTIs. 相似文献
7.
Ling-Cong KONG Duo GAO Bo-Yan JIA Zi WANG Yun-Hang GAO Zhi-Hua PEI Shu-Ming LIU Jiu-Qing XIN Hong-Xia MA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(2):293-296
Mycoplasma bovis has spread widely throughout the world via animal movement and has become
an important pathogen of bovine respiratory disease. However, the minimum inhibitory concentrations of
antimicrobials for Mycoplasma bovis have not been studied in China. The objective of this
study was to determine the prevalence and antibiotic resistance of Mycoplasma bovis isolated
from young cattle with respiratory infection in China. Mycoplasma bovis was detected in 32/45
bovine respiratory infection outbreaks at beef farms in 8 provinces in China. The isolates were susceptible or
had medium sensitivity to ciprofloxacin, enrofloxacin and doxycycline, but were frequently resistant to
macrolides (13/32, 41%). An A2058G (Escherichia coli Numbering) mutation located in the
rrnA operon in domain V of 23S rRNA was observed in strains that were resistant to
macrolides. This single mutations at the rrnA operon in domain V of 23S rRNA may play an important role in the
resistance of Mycoplasma bovis strains to macrolides. 相似文献
8.
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9.
Seung-Won YI Tae-Ho CHUNG Seong-Joon JOH Chul PARK Byoung-Yong PARK Gee-Wook SHIN 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1589-1593
The prevalence of resistant
genes against β-lactams in 119 Aeromonas strains was determined. A large
number (99.2%) of the present fish strains were resistant to one or more β- lactams
including ceftiofur, amoxicillin-clavulanic acid, ampicillin, piperacillin and
cefpodoxime. Among antibiotic resistance phenotypes, the simultaneous resistance to all
β-lactams occurred in 25.2% (n=30) of all strains, which consisted of 18 strains of
A. dhakensis, 8 strains of A. caviae, 2 strains of
A. hydrophila and only one strain of A. veronii. For
exploring genetic background of the antibiotic resistances, multiple PCR assays were
subjected to detect β-lactamase-encoding genes, blaTEM,
blaOXA-B and blaCTX-M. In the
results, the blaTEM-1 gene was harbored in all strains,
whereas only 3 strains harbored blaOXA gene. In the case of
blaCTX-M gene, the gene was detected in 21.0% (25 out of
119) of all strains, which countered with 80% (20 out of 25) of A.
dhakensis, 8% (2 out of 25) of A. caviae and 12% (3 out of 25)
of A. hydrophila. In addition, most of the
blaCTX-M positive strains showed simultaneous resistance to
all β-lactams (18 out of 30 strains). In sequence analysis for
blaCTX-M genes detected, they were CTX-M group 1-encoding
genes including blaCTX-M-33 from 3 eel strains of A.
dhakensis. Therefore, A. dhakensis obtained from cultured fish
could represent a reservoir for spreading genes encoding CTX-M group 1 enzymes and hence
should be carefully monitored, especially for its potential risk to public health. 相似文献
10.
In this study, the mechanism conferring multiple drug resistance in several strains of flavobacteria isolated from the ovarian fluids of hatchery reared 3-year old brook trout Salvelinus fontinalis was investigated. Metabolic fingerprinting and 16S rRNA gene sequences identified the isolates as Flavobacterium johnsoniae. The isolates exhibited multiple resistances to a wide range of antimicrobial classes including penicillin, cephem, monobactam, aminoglycoside, and phenicol. Although plasmids and other transposable elements containing antimicrobial resistance genes were not detected, the isolates did contain a genomic sequence for a chloramphenicol-inducible resistance-nodulation-division family multidrug efflux pump system. Efflux pumps are non-specific multidrug efflux systems. They are also a component of cell-cell communication systems, and respond specifically to cell membrane stressors such as oxidative or nitrosative stress. Understanding of efflux pump mediated antibiotic resistances will affect efficacy of clinical treatments of fishes associated with F. johnsoniae epizootics. 相似文献
11.
Daisuke TAKAMATSU Masumi SATO Mikio YOSHIYAMA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2016,78(1):29-34
Melissococcus plutonius is an important pathogen that causes
European foulbrood (EFB) in honeybee larvae. Recently, we discovered a group of M.
plutonius strains that are phenotypically and genetically distinct from other
strains. These strains belong to clonal complex (CC) 12, as determined by multilocus
sequence typing analysis, and show atypical cultural and biochemical characteristics
in vitro compared with strains of other CCs tested. Although EFB is
considered to be a purely intestinal infection according to early studies, it is unknown
whether the recently found CC12 strains cause EFB by the same pathomechanism. In this
study, to obtain a better understanding of EFB, we infected European honeybee
(Apis mellifera) larvae per os with a
well-characterized CC12 strain, DAT561, and analyzed the larvae histopathologically.
Ingested DAT561 was mainly localized in the midgut lumen surrounded by the peritrophic
matrix (PM) in the larvae. In badly affected larvae, the PM and midgut epithelial cells
degenerated, and some bacterial cells were detected outside of the midgut. However, they
did not proliferate in the deep tissues actively. By immunohistochemical analysis, the PM
was stained with anti-M. plutonius serum in most of the DAT561-infected
larvae. In some larvae, luminal surfaces of the PM were more strongly stained than the
inside. These results suggest that infection of CC12 strain in honeybee larvae is
essentially confined to the intestine. Moreover, our results imply the presence of
M. plutonius-derived substances diffusing into the larval tissues in
the course of infection. 相似文献
12.
13.
Karin S?derqvist Sofia Boqvist Georges Wauters Ivar V?gsholm Susanne Thisted-Lambertz 《Acta veterinaria Scandinavica》2012,54(1):39
Background
Pigs are regarded as the main reservoir for human pathogenic Yersinia enterocolitica, which is dominated by bioserotype 4/O:3. Other animals, including sheep, have occasionally been reported as carriers of pathogenic strains of Y. enterocolitica. To our knowledge, this is the first study performed in the Nordic countries in which the presence of Y. enterocolitica in sheep is investigated.Methods
Tonsils and faecal samples collected from sheep slaughtered on the island Gotland (Sweden) from September 2010 through January 2011 were analysed for presence of Y. enterocolitica. In an attempt to maximize recovery, several cultural strategies were applied. Various non-selective media were used and different temperatures and durations of the enrichment were applied before subculturing on Cefsulodin Irgasan Novobiocin (CIN) agar. Presumptive Y. enterocolitica colonies were subjected to urease, API 20E and agglutination test. Yersinia enterocolitica isolates were biotyped, serotyped, and tested for pathogenicity using a TaqMan PCR directed towards the ail-gene that is associated with human pathogenic strains of Y. enterocolitica.Results
The samples collected from 99 sheep yielded 567 presumptive Y. enterocolitica colonies. Eighty urease positive isolates, from 35 sheep, were identified as Y. enterocolitica by API 20E. Thirty-four of 35 further subtyped Y. enterocolitica isolates, all from faecal samples, belonged to biotype 1A serotype O:5, O:6. O:13,7 and O:10. One strain was Yersinia mollaretii serotype O:62. No human pathogenic strains of Y. enterocolitica were found in the investigated sheep. Other species identified were Y. kristensenii (n = 4), Y. frederiksenii/intermedia (n = 3), Providencia rettgeri (n = 2), Serratia marcescens (n = 1) and Raoultella ornithinolytica (n = 1).Conclusions
This study does not support the hypothesis that sheep play an important role in transmission of the known human pathogenic Y. enterocolitica in the studied geographical region. However, because there are studies indicating that some strains of Y. enterocolitica biotype 1A may cause disease in humans, the relative importance of sheep as carriers of human pathogenic strains of Y. enterocolitica remains unclear. Tonsils do not appear to be favourable sites for Y. enterocolitica biotype 1A in sheep. 相似文献14.
Mai YAMAMOTO Takashige KASHIMOTO Ping TONG Jianbo XIAO Michiko SUGIYAMA Miyuki INOUE Rie MATSUNAGA Kohei HOSOHARA Kazue NAKATA Kenji YOKOTA Keiji OGUMA Koichiro YAMAMOTO 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):823-828
Vibrio vulnificus is the causative agent of primary septicemia, wound
infection and gastroenteritis in immunocompromised people. In this study, signature-tagged
mutagenesis (STM) was applied to identify the virulence genes of V.
vulnificus. Using STM, 6,480 mutants in total were constructed and divided into
81 sets (INPUT pools); each mutant in a set was assigned a different tag. Each INPUT pool
was intraperitoneally injected into iron-overloaded mice, and in vivo
surviving mutants were collected from blood samples from the heart (OUTPUT pools). From
the genomic DNA of mixed INPUT or OUTPUT pools, digoxigenin-labeled DNA probes against the
tagged region were prepared and used for dot hybridization. Thirty tentatively attenuated
mutants, which were hybridized clearly with INPUT probes but barely with OUTPUT probes,
were negatively selected. Lethal doses of 11 of the 30 mutants were reduced to more than
1/100; of these, the lethal doses of 2 were reduced to as low as 1/100,000.
Transposon-inserted genes in the 11 attenuated mutants were those for IMP dehydrogenase,
UDP-N-acetylglucosamine-2-epimerase, aspartokinase, phosphoribosylformylglycinamidine
cyclo-ligase, malate Na (+) symporter and hypothetical protein. When mice were immunized
with an attenuated mutant strain into which IMP dehydrogenase had been inserted with a
transposon, they were protected against V. vulnificus infection. In this
study, we demonstrated that the STM method can be used to search for the virulence genes
of V. vulnificus. 相似文献
15.
Talah Kanbar Andrey V. Voytenko J?rg Alber Christoph L?mmler Reinhard Weiss Vladimir N. Skvortzov 《Journal of veterinary science (Suw?n-si, Korea)》2008,9(3):327-329
In the present study, Staphylococcus (S.) hyicus strains isolated in Russia (n = 23) and Germany (n = 17) were investigated for the prevalence of the previously described genes sheta and shetb. Sheta was detected in 16 S. hyicus strains. Sheta-positive strains were mainly found among strains isolated from exudative epidermitis, and frequently together with the exfoliative toxin-encoding genes exhD and exhC. Partial sequencing of sheta in a single S. hyicus strain revealed an almost complete match with the sheta sequence obtained from GenBank. None of the S. hyicus strains displayed a positive reaction with the shetb-specific oligonucleotide primer used in the present study. According to the present results, the exotoxin encoding gene sheta seems to be distributed among S. hyicus strains in Russia and Germany. The toxigenic potential of this exotoxin, which does not have the classical structure of a staphylococcal exfoliative toxin, remains to be elucidated. 相似文献
16.
Tara Roth Janet Foley Joy Worth Jonah Piovia-Scott Karen Pope Sharon Lawler 《Comparative immunology, microbiology and infectious diseases》2013
Amphibians are experiencing global declines due in part to the infectious disease chytridiomycosis. Some symbiotic bacteria residents on frog skin have been shown to inhibit the growth of Batrachochytrium dendrobatitis (Bd) but few studies have attempted to fully describe the resident bacterial flora of frog skin. We cultured and sequenced 130 bacterial isolates from frogs collected from the California Klamath Range, recovering predominantly Gram-negative bacteria from 20 higher order taxa and 31 genera. There were also a large number of unclassifiable isolates. Forty-three isolates were assessed for their ability to inhibit the growth of Bd in vitro; of these, two had strong and three had slight anti-Bd activity. We suggest that many bacterial species may play a secondary role in Bd resistance, acting synergistically with inhibitory species. Future research is required in order to characterize these interactions. Understanding the relationships between bacterial strains may be important in predicting and managing the effects of future anti-Bd treatments such as antimicrobial compounds or probiotic bacteria. 相似文献
17.
《The Journal of Applied Poultry Research》2014,23(2):221-227
The demand for foods that are free of pathogens and chemical residues has increased interest in the use of plant-based products as natural antimicrobials. Essential oils (EO) from plants are natural compounds that have been shown to have antimicrobial properties against food-borne pathogens. The objective of the current study was to determine the ability of various concentrations of 4 selected EO to inhibit Salmonella enterica (3 different serovars and a cocktail of all 3) and Campylobacter (2 strains of Campylobacter jejuni, one strain of Campylobacter coli, and a cocktail of all 3). The disc diffusion method was used to screen the oils of thyme, orange, rosemary, and clove oil. The minimum inhibitory concentration or minimum bactericidal concentration of the EO was determined using a 2-fold broth dilution method at concentrations ranging from 0.0008 to 1.000% (vol/vol). Two independent experiments were performed. Zones of inhibition (ZI) were expressed in millimeters and concentrations were expressed in percentages. All the oils demonstrated antibacterial activity against the strains tested. However, thyme oil demonstrated the strongest inhibitory activity than other oils against Salmonella (ZI of 18.5 mm). In general, Campylobacter was more susceptible to the antibacterial activity of EO, with plates containing thyme or clove oil showing no growth. Orange oil was also highly effective on Campylobacter, with a mean ZI of 17.5 mm. The least expensive treatment effective against both Salmonella and Campylobacter was a combination of 100% concentrations of thyme and orange oil combined on a 50:50 proportion. Tested on the same strains of bacteria, the thyme-orange combination (TOC) had a mean ZI of 20.5 mm for Salmonella and 21.3 mm for Campylobacter. Thyme-orange combination demonstrated a synergetic effect against Salmonella, but no such effect was noticed for Campylobacter. On average, 0.14% TOC was required to inhibit both pathogens. Hence, TOC can be considered as a potential antimicrobial for future studies on food systems. 相似文献
18.
Seong Bin Park Kyoung Kwon In Seok Cha Ho Bin Jang Seong Won Nho Fernand F. Fagutao Young Kyu Kim Jong Earn Yu Tae Sung Jung 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(1):163-166
A multiplex PCR protocol was established to simultaneously detect major bacterial pathogens in olive flounder (Paralichthys olivaceus) including Edwardsiella (E.) tarda, Streptococcus (S.) parauberis, and S. iniae. The PCR assay was able to detect 0.01 ng of E. tarda, 0.1 ng of S. parauberis, and 1 ng of S. iniae genomic DNA. Furthermore, this technique was found to have high specificity when tested with related bacterial species. This method represents a cheaper, faster, and reliable alternative for identifying major bacterial pathogens in olive flounder, the most important farmed fish in Korea. 相似文献
19.
Arunee THANASARASAKULPONG Pichayanut POOLPERM Pallop TANKAEW Takuo SAWADA Nattawooti STHITMATEE 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):321-326
Recombinant outer membrane protein H (rOmpH) is a potential fowl cholera vaccine
candidate. The present study was aimed at developing rOmpH formulations for intranasal
administration. The rOmpH was purified and formulated with either Escherichia
coli enterotoxin B (LTB) or CpG oligodeoxynucleotides (ODN) as an adjuvant.
Antibody responses in chickens intranasally immunized with rOmpH in combination with 2
different adjuvants were significantly increased (P<0.05) post
immunization. Chicken survival rates showed that rOmpH formulated with ODN and LTB
elicited 90% and 70% protection, respectively. Our findings indicated that rOmpH
formulated with ODN elicited protection better than that formulated with LTB. Therefore,
the vaccines formulations in the present study can be considered new intranasal vaccine
formulations for fowl cholera in chickens. 相似文献
20.
Ling-Cong KONG Duo GAO Yun-Hang GAO Shu-Ming LIU Hong-Xia MA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(12):1655-1657
The minimum inhibitory
concentrations (MICs), mutation prevention concentrations (MPCs) and contribution of
quinolone resistance-determining region (QRDR) mutations to fluoroquinolone
(ciprofloxacin, enrofloxacin and orbifloxacin) susceptibility in 23 Pasteurella
multocida (Pm) isolates were investigated.
Fluoroquinolone-susceptible isolates (MICs ≤0.25 µg/ml,
9 isolates) had no QRDR mutations, and their respective MPCs were low.
Fluoroquinolone-intermediate isolates (MICs=0.5 µg/ml,
14 isolates) had QRDR mutations (Asp87 to Asn or Ala84 to Pro in gyrA),
and their respective MPCs were high (4–32 µg/ml).
First-step mutants (n=5) and laboratory-derived highly resistant fluoroquinolone mutants
(n=5) also had QRDR mutations. The MICs of fluoroquinolones for mutant-derived strains
were decreased in the presence of efflux inhibitors. The results indicated that the
fluoroquinolone resistance of Pm is mainly due to multiple target gene
mutations in gyrA and parC and the overexpression of
efflux pump genes. 相似文献