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1.
Luke Randall Katharina Heinrich Robert Horton Lucy Brunton Matthew Sharman Victoria Bailey-Horne Meenaxi Sharma Ian McLaren Nick Coldham Chris Teale Jeff Jones 《Research in veterinary science》2014
Waste milk samples from 103 farms in England and Wales were examined for the presence of β-lactam antibiotics and ESBL-producing Enterobacteriaceae. Approximately 10 months after the initial sampling, further waste milk, environmental and faecal samples from farms shown to be positive for CTX-M Escherichia coli were investigated further. Isolates with an ESBL phenotype were tested by PCR for the presence of blaCTX-M, blaOXA, blaSHV and blaTEM genes. Isolates positive for blaCTX-M were sequenced to determine CTX-M type. Representative isolates were further examined by PFGE, plasmid replicon typing and serotyping. Of particular interest, 21.4% of waste milk samples contained residues of the cephalosporin cefquinome, which was significantly associated with CTX-M bacteria. Such bacteria occurred in 5.8% of the waste milk samples (including 3.9% CTX-M E. coli). CTX-M types identified were 1, 14, 14b and 15, but none of the E. coli were serotype O25, the serotype of the human pandemic strain. 相似文献
2.
Tetsuo Asai Kaori Masani Chizuru Sato Mototaka Hiki Masaru Usui Kotaro Baba Manao Ozawa Kazuki Harada Hiroshi Aoki Takuo Sawada 《Acta veterinaria Scandinavica》2011,53(1):52
A total of 318 Escherichia coli isolates obtained from different food-producing animals affected with colibacillosis between 2001 and 2006 were subjected to phylogenetic analysis: 72 bovine isolates, 89 poultry isolates and 157 porcine isolates. Overall, the phylogenetic group A was predominant in isolates from cattle (36/72, 50%) and pigs (101/157, 64.3%) whereas groups A (44/89, 49.4%) and D (40/89, 44.9%) were predominant in isolates from poultry. In addition, group B2 was not found among diseased food-producing animals except for a poultry isolate. Thus, the phylogenetic group distribution of E. coli from diseased animals was different by animal species. Among the 318 isolates, cefazolin resistance (minimum inhibitory concentrations: ≥32 μg/ml) was found in six bovine isolates, 29 poultry isolates and three porcine isolates. Of them, 11 isolates (nine from poultry and two from cattle) produced extended spectrum β-lactamase (ESBL). The two bovine isolates produced blaCTX-M-2, while the nine poultry isolates produced blaCTX-M-25 (4), blaSHV-2 (3), blaCTX-M-15 (1) and blaCTX-M-2 (1). Thus, our results showed that several types of ESBL were identified and three types of β-lactamase (SHV-2, CTX-M-25 and CTX-M-15) were observed for the first time in E. coli from diseased animals in Japan. 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.
Yao ZOU Xiaoming ZHU Hassan Mushtaq MUHAMMAD Ping JIANG Yufeng LI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(6):653-660
Recently, a series of acute swine erysipelas outbreaks occurred in Eastern China. Eight
strains isolated from cases of septicemia were determined as serotype 1a, and 4 of the
isolates were resistant to acriflavine. One isolate strain named was attenuated
on agar media containing acriflavine dye. The 432-bp hypervariable region in
spaA gene of the field and attenuated strains were amplified and
sequenced. It was further compared with the vaccine strain G4T10,
and thus, the eight field strains can be divided into four spaA-types.
The partial spaA gene analysis also showed that no point mutations
occurred among different archived passages of HX130709 during the attenuation. Results of
pulsed-field gel electrophoresis showed that eight distinct patterns with 22 to 30 DNA
fragment bands were produced from field strains, and twelve distinct patterns with 23 to
27 DNA fragment bands were produced from different passages of the attenuated strains.
Mouse pathogenicity test showed that the mortality of the mice infected with
104 CFU field strains was 100% and the attenuation of strain HX130709
occurred between 46 and 50 passages. All the field and attenuated strains were highly
sensitive to β-lactam antibiotics, tetracyclines and macrolides. So, we can make
conclusions that the acute swine erysipelas outbreaks in Eastern China were caused by
serotype 1a E. rhusiopathiae strains with different biochemical
characteristics, and the virulence of serotype 1a E. rhusiopathiae
strains is unrelated with some point mutations in 432-bp hypervariable region of the
spaA gene. HX130709相似文献
5.
Irfan Ahmad MIR Bablu KUMAR Anil TAKU Farah FARIDI Mohd. Altaf BHAT Naseer Ahmad BABA Tahir MAQBOOL 《Journal of Equine Science》2013,24(3):53-55
Present study was undertaken to study the prevalence of β-haemolytic streptococci in
equine of northern temperate region of Jammu and Kashmir, India. One hundred and forty one
samples were collected in duplicate from nasopharyngeal tract of diseased (53) and
apparently healthy equine (88) for isolation and direct PCR. A total of 77 isolates of
streptococci were recovered from 141 samples with an overall prevalence rate of 54.60%.
Out of these 77 isolates, 52 were from diseased and 25 from apparently healthy animals. Of
the 77 isolates, 4 were identified as Streptococcus equi subsp.
equi, 56 as S. equi subsp.
zooepidemicus and 17 as S. dysgalactiae subsp.
equisimilis. Thus the overall prevalence of S. equi subsp.
equi, S. equi subsp. zooepidemicus
and S. dysgalactiae subsp. equisimilis was 2.83, 39.71
and 12.05% respectively. The sensitivity of the PCR for the detection of S.
equi species was found higher when attempted from direct swab samples. 相似文献
6.
Hiroaki SHIGEMURA Takashi MAEDA Shiko NAKAYAMA Akira OHISHI Yuki CARLE Eiko OOKUMA Yoshiki ETOH Shinichiro HIRAI Mari MATSUI Hirokazu KIMURA Tsuyoshi SEKIZUKA Makoto KURODA Nobuyuki SERA Yasuo INOSHIMA Koichi MURAKAMI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(9):1345
Dissemination of extended-spectrum cephalosporin (ESC)-resistant Salmonella is a public health concern in the egg production industry. ESC-resistant Salmonella often acquires the bla gene via insertion sequences (ISs). Therefore, this study aimed to assess antimicrobial resistance in Salmonella from Japanese layer breeding chains and egg processing chains, and determine the genetic profiles of IS-like elements in ESC-resistant Salmonella. Antimicrobial susceptibility testing was performed on 224 isolates from 49 facilities involving layer breeder farms, hatcheries, pullet-rearing farms, and layer farms in breeding chains along with egg processing chains. ESC-resistant Salmonella strains were whole-genome sequenced. Among them, 40 (17.9%) were resistant to at least streptomycin, tetracycline, ampicillin, chloramphenicol, cefpodoxime, nalidixic acid, ciprofloxacin, and/or kanamycin despite lacking resistance to azithromycin and meropenem. Moreover, 15 were ESC-resistant Salmonella harboring blaCMY-2 (Salmonella enterica serovar Ohio, n=12; S. Braenderup, n=1; untypeable with O7:b:-, n=1) and blaCTX-M-14 (S. Cerro, n=1). IncA/C2 plasmids containing ISEcp1, IS26, and multiple antimicrobial resistance genes (including blaCMY-2) were identified in S. Ohio isolates from pullet-rearing and layer farms belonging to the same company. Chromosomal integration of partial or whole IncA/C2 plasmids was seen with two S. Ohio isolates via ISEcp1 or IS26, respectively. Antimicrobial resistance genes such as blaCMY-2 might be transmitted among the upper and the lower levels of layer breeding chains via the replicon type IncA/C2 plasmids containing ISEcp1 and IS26. 相似文献
7.
Mohamed M’BAYE Guohua HUA Hamid Ali KHAN Liguo YANG 《The Journal of reproduction and development》2015,61(5):391-397
Inhibins are members of the TGFβ superfamily and act as suppressors
of follicle stimulating hormone (FSH) secretion from pituitary glands
via a negative feedback mechanism to regulate folliculogenesis. In
this study, the INHBB gene was knocked down by three
RNAi-Ready pSIREN-RetroQ-ZsGreen vector- mediated recombinant plasmids
to explore the effects of INHBB silencing on
granulosa cell (GC) cell cycle, apoptosis and steroid production
in vitro. Quantitative real-time polymerase chain
reaction, Western blot, flow cytometry and ELISA were performed to
evaluate the role of INHBB in the mouse GC cell
cycle, apoptosis and steroid production in vitro. The
results showed that the relative mRNA and protein expression of
INHBB in mouse GCs can be significantly reduced by
RNAi with pshRNA-B1, pshRNA-B2 and pshRNA-B3 plasmids, with pshRNA-B3
having the best knockdown efficiency. Downregulation of the expression
of INHBB significantly arrests cells in the G1 phase
of the cell cycle and increases the apoptosis rate in GCs. This was
further confirmed by downregulation of the protein expressions of
Cyclin D1, Cyclin E and Bcl2, while the protein expression of Bax was
upregulated. In addition, specific downregulation of
INHBB markedly decreased the concentration of
estradiol and progesterone, which was further validated by the
decrease in the mRNA levels of CYP19A1and
CYP11A1. These findings suggest that inhibin βB is
important in the regulation of apoptosis and cell cycle progression in
granulosa cells. Furthermore, the inhibin βB subunit has a role in the
regulation of steroid hormone biosynthesis. Evidence is accumulating
to support the concept that inhibin βB is physiologically essential
for early folliculogenesis in the mouse. 相似文献
8.
Expression dynamics of bovine MX genes in the endometrium and placenta during
early to mid pregnancy
Takahiro SHIROZU Keisuke SASAKI Manabu KAWAHARA Yojiro YANAGAWA Masashi NAGANO Nobuhiko YAMAUCHI Masashi TAKAHASHI 《The Journal of reproduction and development》2016,62(1):29-35
MX belongs to a family of type I interferon (IFN)-stimulated genes, and the MX protein has
antiviral activity. MX has at least two isoforms, known as MX1 and
MX2, in mammals. Moreover, bovine MX1 has been found to have alternative
splice variants—namely, MX1-a and MX1B. In ruminants, IFN-τ—a type I IFN—is
temporarily produced from the conceptus before implantation and induces MX expression in the
endometrium. However, the expression dynamics of MX after implantation are not clear. In the
present study, we investigated the expression of MX1-a, MX1B and
MX2 in the endometrium and placenta before and after implantation along with the expression
of IFN-α, type I receptors (IFNAR1 and IFNAR2) and
interferon regulatory factors (IRF3 and IRF9). Pregnant uterine samples were
divided into five groups according to pregnancy days 14–18, 25–40, 50–70, 80–100, and 130–150. Tissue samples
were collected from the intercaruncular endometrium (IC), caruncular endometrium (C) and fetal placenta (P).
Although all the MX expressions were significantly higher in the IC and C at days 14–18,
presumably caused by embryo-secreted IFN-τ stimulation, their expressions were also detectable in the IC, C
and P after implantation. Furthermore, IFN-α expression was significantly higher in the IC.
RT-PCR indicated IFNAR1, IFNAR2, IRF3 and
IRF9 mRNA in all the tissues during pregnancy. These results suggest that all the
MX genes are affected by the type I IFN pathway during pregnancy and are involved in an
immune response to protect the mother and fetus. 相似文献
9.
Bo Yu Yanan Zhang Li Yang Jinge Xu Shijin Bu 《The Onderstepoort journal of veterinary research》2021,88(1)
This study was carried out to investigate the resistance phenotypes and resistance genes of Escherichia coli from swine in Guizhou, China. A total of 47 E. coli strains isolated between 2013 and 2018 were tested using the Kirby–Bauer (K–B) method to verify their resistance to 19 common clinical antimicrobials. Five classes consisting of 29 resistance genes were detected using polymerase chain reaction. The status regarding extended-spectrum β-lactamase (ESBL) and the relationship between ESBL CTX-M-type β-lactamase genes and plasmid-mediated quinolone resistance (PMQR) genes were analysed. A total of 46 strains (97.9%) were found to be multidrug resistant. Amongst them, 27 strains (57.4%) were resistant to more than eight antimicrobials, and the maximum number of resistant antimicrobial agents was 16. Twenty antibiotic resistance genes were detected, including six β-lactamase genes blaTEM (74.5%), blaCTX-M-9G (29.8%), blaDHA (17.0%), blaCTX-M-1G (10.6%), blaSHV (8.5%), blaOXA (2.1%), five aminoglycoside-modifying enzyme genes aac(3′)-IV (93.6%), aadA1 (78.7%), aadA2 (76.6%), aac(3′)-II c (55.3%), aac(6′)-Ib (2.1%) and five amphenicol resistance genes floR (70.2%), cmlA (53.2%), cat2 (10.6%), cat1 (6.4%), cmlB (2.1%), three PMQR genes qnrS (55.3%), oqxA (53.2%), qepA (27.7%) and polypeptide resistance gene mcr-1 (40.4%). The detection rate of ESBL-positive strains was 80.9% (38/47) and ESBL TEM-type was the most abundant ESBLs. The percentage of the PMQR gene in blaCTX-M-positive strains was high, and the detection rate of blaCTX-M-9G was the highest in CTX-M type. It is clear that multiple drug resistant E. coli is common in healthy swine in this study. Extended-spectrum β-lactamase is very abundant in the E. coli strains isolated from swine and most of them are multiple compound genotypes. 相似文献
10.
Sun Young Hwang Young Kyung Park Hye Cheong Koo Yong Ho Park 《Journal of veterinary science (Suw?n-si, Korea)》2010,11(2):125-131
Staphylococcus aureus is a major etiological pathogen of bovine mastitis, which triggers significant economic losses in dairy herds worldwide. In this study, S. aureus strains isolated from the milk of cows suffering from mastitis in Korea were investigated by spa typing and staphylococcal enterotoxin (SE) gene profiling. Forty-four S. aureus strains were isolated from 26 farms in five provinces. All isolates grouped into five clusters and two singletons based on 14 spa types. Cluster 1 and 2 isolates comprised 38.6% and 36.4% of total isolates, respectively, which were distributed in more than four provinces. SE and SE-like toxin genes were detected in 34 (77.3%) isolates and the most frequently detected SE gene profile was seg, sei, selm, seln, and selo genes (16 isolates, 36.3%), which was comparable to one of the genomic islands, Type I νSaβ. This is a first report of spa types and the prevalence of the recently described SE and SE-like toxin genes among S. aureus isolates from bovine raw milk in Korea. Two predominant spa groups were distributed widely and recently described SE and SE-like toxin genes were detected frequently. 相似文献
11.
Jian-Hong Gu Xi-Shuai Tong Guo-Hong Chen Xue-Zhong Liu Jian-Chun Bian Yan Yuan Zong-Ping Liu 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(1):133-140
To investigate 1α,25-(OH)2D3 regulation of matrix metalloproteinase-9 (MMP-9) protein expression during osteoclast formation and differentiation, receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) were administered to induce the differentiation of RAW264.7 cells into osteoclasts. The cells were incubated with different concentrations of 1α,25-(OH)2D3 during culturing, and cell proliferation was measured using the methylthiazol tetrazolium method. Osteoclast formation was confirmed using tartrate-resistant acid phosphatase (TRAP) staining and assessing bone lacunar resorption. MMP-9 protein expression levels were measured with Western blotting. We showed that 1α,25-(OH)2D3 inhibited RAW264.7 cell proliferation induced by RANKL and M-CSF, increased the numbers of TRAP-positive osteoclasts and their nuclei, enhanced osteoclast bone resorption, and promoted MMP-9 protein expression in a concentration-dependent manner. These findings indicate that 1α,25-(OH)2D3 administered at a physiological relevant concentration promoted osteoclast formation and could regulate osteoclast bone metabolism by increasing MMP-9 protein expression during osteoclast differentiation. 相似文献
12.
Hee-Jin Dong Ae-Ri Cho Tae-Wook Hahn Seongbeom Cho 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(2):317-325
A multiplex loop-mediated isothermal amplification (mLAMP) assay was developed for simultaneous detection of the stx1 and stx2 genes and applied for detection of shiga toxin-producing Escherichia coli (STEC) in cattle farm samples. Two target genes were distinguished based on Tm values of 85.03 ± 0.54℃ for stx1 and 87.47 ± 0.35℃ for stx2. The mLAMP assay was specific (100% inclusivity and exclusivity), sensitive (with a detection limit as low as 10 fg/µL), and quantifiable (R2 = 0.9313). The efficacy and sensitivity were measured to evaluate applicability of the mLAMP assay to cattle farm samples. A total of 12 (12/253; 4.7%) and 17 (17/253; 6.7%) STEC O157, and 11 (11/236; 4.7%) non-O157 STEC strains were isolated from cattle farm samples by conventional selective culture, immunomagnetic separation, and PCR-based culture methods, respectively. The coinciding multiplex PCR and mLAMP results for the types of shiga toxin revealed the value of the mLAMP assay in terms of accuracy and rapidity for characterizing shiga toxin genes. Furthermore, the high detection rate of specific genes from enrichment broth samples indicates the potential utility of this assay as a screening method for detecting STEC in cattle farm samples. 相似文献
13.
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
14.
Background
The emergence and dissemination of antimicrobial resistance (AMR) is a growing concern to public and animal health. The contribution attributable to wildlife remains unclear. In this study two unrelated wildlife species herring gulls (Larus argentatus) and a hybrid deer (Cervus elaphus x Cervus nippon) were investigated for the presence of Escherichia coli expressing an AMR phenotype.Findings
Bacterial isolates resistant to β-lactam compounds were identified in both animal species and the production of functional β-lactamase was confirmed using nitrocefin. The prevalence of resistant isolates was higher in herring gulls (87%) compared to deer (31%). Resistance to this class of antibiotic was found only in non-pathogenic E. coli in herring gulls and in both pathogenic and non-pathogenic E. coli strains in deer.Conclusions
The presence of AMR in wildlife has implications for public health, food safety and potable water source protection among others. 相似文献15.
Sandra Bj?rk Renee B?ge Benon M Kanyima Susanne André Maria G Nassuna-Musoke David O Owiny Ylva Persson 《Irish veterinary journal》2014,67(1):12
Background
Coagulase negative staphylococci (CNS) are the most common pathogens leading to subclinical mastitis (SCM) in dairy cattle in Uganda. Coagulase negative staphylococci can vary between bacterial species in how they cause disease. The aim of the study was to characterize CNS, from cows with SCM in Uganda, at the species level.Findings
Quarter milk samples (n = 166) were collected from 78 animals with SCM. Bacteriological analyses were carried out at Makerere University, Kampala, Uganda and at the National Veterinary Institute (SVA), Uppsala, Sweden. The most common pathogens found in milk samples from cows with SCM were CNS (31.7%). Two species of CNS were found, S. epidermidis (85%) and S. haemolyticus (15%). Of the CNS isolates, 16/20 (80%) were positive for β-lactamase production (β+).Conclusions
In milk samples from cows with SCM caused by CNS, S. epidermidis was most prevalent, followed by S. haemolyticus. 相似文献16.
Akifumi OHTANI Masahito KUBO Hiroshi SHIMODA Kenji OHYA Tadashi IRIBE Daiki OHISHI Daiji ENDOH Tsutomu OMATSU Tetsuya MIZUTANI Hideto FUKUSHI Ken MAEDA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(7):777-782
Chlamydia pecorum (designated 22–58) was isolated in 2010 in
HmLu-1 cells from the jejunum of a calf which died of necrotizing enterocolitis in
Yamaguchi Prefecture, Japan. Immunohistochemical staining identified C.
pecorum positive reactions in the jejunal villi. C. pecorum,
designated 24–100, was isolated from the feces of a calf with diarrhea in another farm in
Yamaguchi Prefecture in 2012. A significant increase in neutralizing antibody titers
against C. pecorum was confirmed in paired sera. Nucleotide sequence
identities of omp1 genes of the 2 isolates were 100%. The isolates were
genetically and antigenically more closely related to C. pecorum
Bo/Yokohama strain isolated from cattle with enteritis in Japan than to the other
prototype strains, Bo/Maeda isolated from cattle with pneumonia and Ov/IPA isolated from
sheep with polyarthritis. These results indicate that C. pecorum strains
similar to 22–58 and 24–100 might be endemic in Yamaguchi Prefecture and cause enteric
disease in cattle. 相似文献
17.
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
18.
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19.
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
20.
Haruka SASAKI Kiyoko WATANABE Toshizo TOYAMA Yasunori KOYATA Nobushiro HAMADA 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(3):265-271
Porphyromonas gulae is considered to be associated with canine
periodontitis. We have previously reported that the P. gulae American
Type Culture Collection (ATCC) 51700 comprised 41-kDa fimbriae. The purpose of the present
study was to demonstrate the roles of 41-kDa fimbrial protein in periodontal disease. In
this study, we examined the involvement of the 41-kDa fimbrial protein in osteoclast
differentiation and cytokine production in murine macrophages. Furthermore, alveolar bone
resorption induced by P. gulae infection in rats was evaluated. To
estimate osteoclast differentiation, bone marrow cells and MC3T3-G2/PA6 cells were
cultured with or without the 41-kDa fimbrial protein for 7 days. BALB/c mouse peritoneal
macrophages were stimulated with the 41-kDa fimbrial protein, and the levels of
interleukin (IL)-1β and tumor necrosis factor (TNF)-α production were determined by
enzyme-linked immunosorbent assay. Osteoclast differentiation was significantly enhanced
by treatment with the 41-kDa fimbrial protein in a dose-dependent manner. The total area
of pits formed on the dentine slices with osteoclasts incubated with the 41-kDa fimbrial
protein was significantly greater than that of the control. The purified 41-kDa fimbrial
protein induced IL-1β and TNF-α production in BALB/c mouse peritoneal macrophages after 6
hr of incubation in a dose-dependent manner. The bone loss level in rats infected with
P. gulae was significantly higher than that of the sham-infected rats.
These results suggest that P. gulae 41-kDa fimbriae play important roles
in the pathogenesis of periodontal disease. 相似文献