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1.
V. J Rejish Kumar Seo Byeong Joo Mun Mi Ran Kim Chul-Joong Lee Insun Kim Hongik Park Yong-Ha 《Tropical animal health and production》2010,42(8):1855-1860
A total of 310 bacterial strains isolated from the porcine gastrointestinal tract were tested for their activity against transmissible
gastroenteritis (TGE) coronavirus and other enteric pathogens. Based on activity, the strains Probio-38 and Probio-37 were
selected as potential probiotics and identified as Lactobacillus plantarum Probio-38 and Lactobacillus salivarius Probio-37 respectively by 16S rRNA gene sequencing. Supernatants of these strains inhibited TGE coronavirus in vitro in ST
cells, without any cytopathic effect even after 72 h of incubation. Both the strains exhibited high survival in synthetic
gastric juice. The strains were resistant to 5% porcine bile and exhibited antimicrobial activity against all the 13 enteric
bacterial pathogens tested. These strains also exhibited resistance to most of the antibiotics analyzed. The inhibition of
transmissible gastroenteritis coronavirus and enteric bacterial pathogens as well as the bile tolerance, high survival in
gastric juice, and the antibiotic resistance indicate that the two isolated bacterial strains are ideal probiotic candidates
for animal application after proper in vivo experiments. 相似文献
2.
[目的]研究抗菌肽对抗生素耐药菌株的抑菌活性。[方法]利用抗性平板划线法从腹泻病牛血便中筛选分离出1株耐药菌,通过16S rDNA序列进行鉴定,采用琼脂孔穴扩散法通过梯度盐酸壮观霉素（spectinomycin,Spe+）、氨苄青霉素（ampicillin,Amp+）、硫酸卡那霉素（kanamycin,Kan+）和氯霉素（chloramphenicol,Cm+）试验确定该菌药敏特性,并利用1种抗菌肽制剂对该菌株进行药敏试验。[结果]经BLAST比对分析该菌16S rDNA序列,鉴定该耐药菌为科氏葡萄球菌（Staphylococcus cohnii）,此菌对Amp+敏感,但对试验中其他抗生素均有耐药性,各梯度抗菌肽对该耐药菌均具有明显的抑菌活性。[结论]抗菌肽能有效抑制耐药科氏葡萄球菌的生长,有望在畜牧生产中代替抗生素使用。 相似文献
3.
Lactobacillus reuteri ATCC 55730 (L. reuteri ATCC 55730) and L. reuteri L22 were studied for their probiotic potential. These two strains were able to produce an antimicrobial substance, termed reuterin, the maximum production of reuterin by these two strains was detected in the late logarithmic growth phase (16 h in MRS and 20 h in LB broths). These two strains could significantly reduce the growth of Salmonella pullorum ATCC 9120 in MRS broth, L. reuteri ATCC 55730 with a reduction of 48.2 ± 4.15% (in 5 log) and 89.7 ± 2.59% (in 4 log) respectively, at the same time, L. reuteri L22 was 69.4 ± 3.48% (in 5 log) and 80.4 ± 3.22% respectively. L. reuteri ATCC 55730 was active against the majority of the pathogenic species, including S. pullorum ATCC 9120 and Escherichia coli O78, while L. reuteri L22 was not as effective as L. reuteri ATCC 55730. The two potential strains were found to survive variably at pH 2.5 and were unaffected by bile salts, while neither of the strains was haemolytic. Moreover, L. reuteri ATCC 55730 exhibited variable susceptibility towards commonly used antibiotics; but L. reuteri L22 showed resistant to most antibiotics in this study. L. reuteri ATCC 55730 consequently was found to significantly increase survival rate in a Salmonella-induced pullorum disease model in chick. To conclude, strain L. reuteri ATCC 55730 possesses desirable probiotic properties, such as antimicrobial activity and immunomodulation in vitro, which were confirmed in vivo by the use of animal models. 相似文献
4.
Repurposing Ionophores as novel antimicrobial agents for the treatment of bovine mastitis caused by Gram‐positive pathogens 
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下载免费PDF全文 Elizabeth E. Hickey Hui San Wong Manouchehr Khazandi Abiodun D. Ogunniyi Kiro R. Petrovski Sanjay Garg Stephen W. Page Ryan O'Handley Darren J. Trott 《Journal of veterinary pharmacology and therapeutics》2018,41(5):746-754
Increasing reports of multidrug‐resistant bacterial infections in animals has created a need for novel antimicrobial agents that do not promote cross‐resistance to critically important antimicrobial classes used in human medicine. In response to the recent emergence of antimicrobial resistance in several bovine mastitis pathogens, in vitro antimicrobial susceptibility was determined for four polyether ionophores (lasalocid, monensin, narasin and salinomycin) against Staphylococcus spp. and Streptococcus spp. isolated from clinical cases. In addition, erythrocyte haemolysis and WST ‐1 cell proliferation assays were used to assess in vitro mammalian cell cytotoxicity and biofilm susceptibility testing was performed using the minimum biofilm eradication concentration (MBEC ?) biofilm assay. Lasalocid, monensin, narasin and salinomycin exhibited bacteriostatic antimicrobial activity against all pathogens tested, including methicillin‐resistant staphylococci, with MIC 90 values <16 μg/ml. Narasin and monensin displayed the least toxicity against mammalian cell lines and all compounds significantly reduced viable cell numbers in a Staphylococcus aureus biofilm. Based on in vitro characterization, all four ionophores offer potentially novel treatments against bovine mastitis but in vivo studies will be essential to determine whether acceptable safety and efficacy is present following intramammary administration. 相似文献
5.
Kobayashi H Nakajima H Shimizu Y Eguchi M Hata E Yamamoto K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2005,67(8):795-800
A total of 151 strains of Mycoplasma hyorhinis isolated from porcine lung lesions (weaned pigs, n=71, and finishers, n=80) were investigated for their in vitro susceptibility to 10 antimicrobial agents. Thirty-one strains (28 from weaned pigs and 3 from finishers) showed resistance to 16-membered macrolide antibiotics and lincomycin. The prevalence of the 16-membered macrolide-resistant M. hyorhinis strain in weaned pigs from Japanese herds has approximately quadrupled in the past 10 years. Several of the 31 strains were examined for mutations in the 23S ribosomal RNA (rRNA). All field strains tested showed a transition of A to G at position 2059 of 23S rRNA-rendered Escherichia coli. On the other hand, individual tylosin- and lincomycin-resistant mutants of M. hyorhinis were selected in vitro from the susceptible type strain BTS7 by 3 to 9 serial passages in subinhibitory concentrations of each antibiotic. The 23S rRNA sequences of both tylosin and lincomycin-resistant mutants were compared with that of the radical BTS7 strain. The BTS7 mutant strain selected by tylosin showed the same transition as the field-isolated strains of A2059G. However, the transition selected in lincomycin showed mutations in domains II and V of 23S rRNA, G2597U, C2611U in domain V, and the addition of an adenine at the pentameric adenine loop in domain II. The strain selected by lincomycin showed an additional point mutation of A2062G selected by tylosin. 相似文献
6.
Selection and characterization of broad‐spectrum antibacterial substance‐producing Lactobacillus curvatus PA40 as a potential probiotic for feed additives 下载免费PDF全文
下载免费PDF全文 Sung Wook Hong Jong‐Hui Kim Hyo Ju Bae Jun‐Sang Ham Jae Gyu Yoo Kun Sub Chung Mi‐Hwa Oh 《Animal Science Journal》2018,89(10):1459-1467
Lactic acid bacteria were screened for potential probiotics for use as feed additives. We obtained 3,000 isolates from feces of: cattle, dogs, goats, and infants; milk; yogurt; cheese; fermented sausages; Kimchi; and Cheonggukjang and tested their antibacterial activity toward indicator pathogens, including Bacillus cereus, Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella enterica Enteritidis. We further tested their tolerance to artificial gastric juice (1% [w/v] pepsin, pH 2.5) and bile acid (0.1% [w/v] oxgall, pH 6.8). Six isolates exhibited strong antibacterial activity against indicator pathogens. The PA40 isolate from Kimchi exhibited marked resistance to artificial gastric juice and bile acid. The antibacterial substances produced by PA40 were stable to heat, pH, and enzymes. Strain PA40 was identified as a Lactobacillus curvatus strain using chemical tests and 16S rDNA sequencing and produced 248.4 mmol/L lactic acid after 48 hr of fermentative growth. The L. curvatus PA40 strain was also highly tolerant of the artificial gastrointestinal model system. Our results indicate that L. curvatus PA40 could be used as a potential probiotic feed additive. 相似文献
7.
大肠杆菌多重耐药株的体外诱导初步研究 《畜牧与饲料科学》2015,36(4):15-15
为了解不同抗菌药物对大肠杆菌体外耐药诱导株的MIC变化特点,以盐酸四环素、盐酸环丙沙星、水杨酸钠、氯霉素作为诱导剂,采用1／2×MIC诱导法,对大肠杆菌质控菌株ATCC25922进行体外诱导试验。于诱导前对试验菌株进行形态学观察和生化鉴定,并于诱导过程中对试验菌株进行形态学观察。于诱导前测定16种抗菌药物对质控菌株的MIC,并于诱导剂浓度达到128×MIC时,测定16种抗菌药物对4株诱导菌株的MIC。结果表明,试验菌株的形态特征和生化反应特性与大肠杆菌一致。诱导前,16种抗菌药物对质控菌株的MIC为0．25-64．00μg／mL;头孢噻肟、盐酸四环素、土霉素、甲砜霉素、诺氟沙星、头孢西丁等抗菌药物对盐酸四环素诱导株的MIC与质控菌株相比．提高幅度均达到或超过4倍,均具有显著性意义;头孢噻肟对盐酸环丙沙星诱导株和氯霉素诱导株的MIC与质控菌株相比．提高倍数都超过了4倍,而其余抗菌药物的MIC变化均无显著性意义。水杨酸钠诱导剂浓度大于16×MIC时,菌株不能生长。结果提示。抗菌药物对盐酸四环素诱导株的MIC变化最明显,表明大肠杆菌在四环素的选择性压力下较易产生耐药性。 相似文献
8.
9.
William V. Bernard Manu Sebastian Bruce Hemming 《Journal of Equine Veterinary Science》2011,31(7):396-399
The gastric mucosa and the mucosa of the right and left dorsal colon were biopsied in each of the 15 horses, and a total of 45 samples were collected. Mucosal samples were cultured using a Lactobacillus enrichment broth. While numerous Lactobacillus strains were identified, Lactobacillus reuteri was the most common organism identified. Sixteen strains of Lactobacillus reuteri were selected for antimicrobial testing. Salmonella antimicrobial activity was identified in six out of 16 strains tested. Organisms with Salmonella antimicrobial activity were cultured from the stratified squamous epithelium of the stomach and the mucosa of the right and left dorsal colon. 相似文献
10.
Vermoote M Pasmans F Flahou B Van Deun K Ducatelle R Haesebrouck F 《Veterinary microbiology》2011,153(3-4):339-342
Helicobacter suis is a very fastidious porcine gastric pathogen, which is also considered to be of zoonotic importance. In vitro antimicrobial susceptibility cannot be determined using standard assays, as this agent only grows in a biphasic medium with an acidic pH. Therefore, a combined agar and broth dilution method was used to analyse the activity of nine antimicrobial agents against nine H. suis isolates. After 48 h microaerobic incubation, minimal inhibitory concentrations (MICs) were determined by software-assisted calculation of bacterial growth. Only for enrofloxacin a bimodal distribution of MICs was demonstrated, indicating acquired resistance in one strain, which showed an AGT→AGG (Ser→Arg) substitution at codon 99 of gyrA. In conclusion, the assay developed here is suitable for determination of the antimicrobial susceptibility of H. suis isolates, although activity of acid sensitive antimicrobial agents may be higher than predicted from MIC endpoints. 相似文献
11.
E. Mateos S. Piriz J. Valle M. Hurtado & S. Vadillo 《Journal of veterinary pharmacology and therapeutics》1997,20(1):21-23
Minimum inhibitory concentrations for 35 antimicrobial agents against 100 Fusobacterium necrophorum isolates from hepatic abscesses in sheep and cattle were determined. Twelve of the thirteen β-lactam antibiotics tested inhibited growth of 100% of strains tested. Of the remaining antimicrobial agents, extensive susceptibility was found for: spiramycin, josamycin, lincomycin, tylosin, oxytetracycline, chlortetracycline, rufloxacin, metronidazole, co-trimoxazole, sulfadimethoxine, virginiamycin and fosfomycin. 相似文献
12.
从天津地区某猪场病猪肺脏脓肿中分离到一株具有β溶血特性的细菌,经形态学与生化特性分析,初步确定为化脓隐秘杆菌(Arcanobacterium pyogenes),并命名为TJjh1913.利用PCR扩增16S rRNA基因,经Blast序列分析,其序列与GenBank数据库中猪源化脓隐秘杆菌的核苷酸序列同源性高达99.... 相似文献
13.
自然发酵泡菜汁中植物乳杆菌的分离鉴定与体外益生特性研究 总被引：1，自引：0，他引：1
利用MRS固体培养基从自然发酵的泡菜汁中分离到1株优势乳酸菌,将其命名为菌株R1,经16S rRNA基因序列分析,并结合生理生化特性和糖发酵试验将其鉴定为植物乳杆菌(Lactobacillus plantarum)。菌株R1具有很强的产酸能力,24 h内可使MRS液体培养基p H从6.14降为3.59。菌株R1的发酵上清液对痢疾志贺氏菌、金黄色葡萄球菌、铜绿假单胞菌、鸡肠炎沙门氏菌、大肠埃希氏菌均有很好的抑制作用。体外益生试验表明,菌株R1能耐受0.3%的胆盐、p H 3.0的酸度以及60℃、30 min的热处理,对人工胃液和人工肠液也有很好的耐受性。菌株R1对头孢类和青霉素类抗生素较敏感,对诺氟沙星、卡那霉素、链霉素等抗生素不敏感。 相似文献
14.
抗菌肽与抗生素的体外抗菌效果比较 总被引：17，自引：0，他引：17
应用由 Hancock实验室改进的微量肉汤稀释法测定了 cecropin P1、cecropin A、magainin 2、defensin 1、bactenecin、lactoferricin和 indolicidin等 7种抗菌肽和盐酸金霉素、去甲万古霉素、土霉素、强力霉素等 4种抗生素的体外抗菌活性 ,并且使用薄层琼脂糖孔穴扩散法比较了抗菌肽中 cecropin P1和 cecropin A与土霉素和呋喃唑酮对大肠杆菌 K88的抑菌效果。结果发现 ,抗菌肽与抗生素一样对几种革兰氏阳性菌和阴性菌都有不同程度的抗菌效果。其中 cecropin A、cecropin P1和 defensin1对大肠杆菌的 2个菌株 ATCC2 5 92 2和 K88的抗菌活性高于抗生素 ,defensin1是各种抗菌肽中对金黄色葡萄球菌抗菌效果最好的。抗生素对试验用金黄色葡萄球菌的抑制活性总体上要好于抗菌肽。与抗生素相比 ,cecropin A、cecropin P1和 indolicidin对猪霍乱沙门氏菌和鼠伤寒沙门氏菌具有更好的抗菌效果。另外 ,抗菌肽的抑菌圈边缘十分清晰 ,而抗生素的整个抑菌圈都比较模糊且界线不明。因此 ,从抗菌效果方面考虑 ,抗菌肽可以代替抗生素用于疾病的预防和治疗 相似文献
15.
The activity of 240 bacterial isolates screened from the gastrointestinal tracts of native chickens were evaluated for use as a potential probiotic in food animal production in order to protect against animal diseases and reduce pathogenic contamination of human food products. In observing the antagonistic activity of 117 bacilli isolates, 10 of these isolates exhibited higher growth inhibition of seven foodborne pathogens, including Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Vibrio cholerae. Beneficial probiotic criteria from these isolates - which included non-pathogenicity, acid and bile salt tolerance, hydrophobicity, and adhesion to intestinal epithelial cells - exhibited that one isolate of NC11 had the most potential as a probiotic. 16S rRNA gene sequencing showed that this NC11 isolate was Bacillus subtilis. This B. subtilis NC11 was sensitive to all antibiotics and was not cytotoxic to intestinal epithelial cells. Reduction of S. Enteritidis attachment to the surfaces of intestinal epithelial cells via action of a cultured medium from B. subtilis NC11 was observed by scanning electron microscopy. B. subtilis NC11 cells, as well as the bacterial cultured medium or the cultured medium adjusted to pH 7, significantly inhibited S. Enteritidis invasion (P<0.01) of intestinal epithelial cells. This study indicates that B. subtilis NC11 has characteristics of a potential probiotic, and exhibits strong inhibition activity against S. Enteritidis infection to intestinal epithelial cells. 相似文献
16.
轮状病毒是引起幼龄动物和儿童病毒性腹泻的主要病原,轮状病毒的分离鉴定为该病的流行病学调查和分子生物学特性研究奠定了基础。本研究采集北京某猪场腹泻发病仔猪肠内容物,将其接种MA104细胞,分离得到一株能产生明显细胞病变的病毒。对分离毒株进行胶体金、实时荧光定量RT-PCR和免疫荧光等方法鉴定,并对分离毒株的VP4、VP6和VP7基因进行测序及序列分析。结果表明,分离毒株为猪A群轮状病毒。按照A群轮状病毒的最新分类方法,确定该分离株VP4、VP6和VP7基因的基因型分别为P[13]型、I5型和G11型。因此,将该分离株命名为Rotavirus A pig/China/BJ/2015/G11P[13]。 相似文献
17.
YUAN Lin HAN Tao NI Jian-qiang KANG Wen-hua WANG Bao-yue LI Xiao-xia CHEN Ya-na ZHAI Xin-yan SHEN Jian-zhong 《中国畜牧兽医》2016,43(12):3306-3313
Rotavirus infections are a major cause of viral diarrheas in young animals and children. Isolation and identification of rotavirus make a contribution to epidemiological survey and molecular biology study.A strain of porcine rotavirus was isolated in MA104 cell cultures from the intestinal contents of piglets with diarrhea in Beijing.The virus was identified to be porcine rotavirus by immunochromatography strip test, Real-time RT-PCR, immunofluorescence test and sequencing analysis.According to the sequence analysis, the virus was classified as group A porcine rotavirus, the genotype of VP4, VP6 and VP7 genes belonged to P[13], I5 and G11, respectively.The virus was designated Rotavirus A pig/China/BJ/2015/G11P[13]. 相似文献
18.
The present study was conducted to study the antibiotic resistance pattern among nontyphoidal Salmonella isolated from human, animal and meat. A total of 37 Salmonella strains isolated from clinical cases (human and animal) and meat during 2008–2009 belonging to 12 serovars were screened
for their antimicrobial resistance pattern using 25 antimicrobial agents falling under 12 different antibiotic classes. All
the Salmonella isolates tested showed multiple drug resistance varying from 5.40% to 100% with 16 of the 25 antibiotics tested. None of
the isolates were sensitive to erythromycin and metronidazole. Resistance was also observed against clindamycin (94.59%),
ampicillin (86.49%), co-trimoxazole (48.65%), colistin (45.94%), nalidixic acid (35.10%), amoxyclave (18.90%), cephalexin,
meropenem, tobramycin, nitrofurantoin, tetracycline, amoxicillin (8.10% each), sparfloxacin and streptomycin (5.40% each).
Isolates from clinical cases of animals were resistant to as many as 16 antibiotics, whereas isolates from human clinical
cases and meat were resistant to 9 and 14 antibiotics, respectively. Overall, 19 resistotypes were recorded. Analysis of multiple
antibiotic resistance index (MARI) indicated that clinical isolates from animals had higher MARI (0.25) as compared to isolates
from food (0.22) and human (0.21). Among the different serotypes studied for antibiogram, Paratyhi B isolates, showed resistance
to three to 13 antibiotics, whereas Typhimurium strains were resistant to four to seven antibiotics. Widespread multidrug
resistance among the isolates from human, animal and meat was observed. Some of the uncommon serotypes exhibited higher resistance
rate. Considerable changes in the resistance pattern were also noted. An interesting finding was the reemergence of sensitivity
to some of the old antibiotics (chloromphenicol, tetracycline). 相似文献
19.
R van den Hoven J A Wagenaar R D Walker 《Journal of veterinary diagnostic investigation》2000,12(3):218-223
The in vitro activity of difloxacin against canine bacterial isolates from clinical cases was studied in the United States and The Netherlands. Minimal inhibitory concentrations (MIC), the postantibiotic effect, the effect of pH on antimicrobial activity, and the bacterial killing rate tests were determined according to standard techniques. The MICs of American and Dutch isolates agreed in general. The MICs of the American gram-negative isolates ranged from 0.06 to 2.0 microg/ml, and the MICs of the Dutch gram-negative isolates ranged from 0.016 to 8.0 microg/ml. A few European strains of Proteus mirabilis and Klebsiella pneumoniae had relatively high MICs. Bordetella bronchiseptica also was less susceptible to difloxacin. The MICs of the American gram-positive cocci ranged from 0.125 to 4.0 microg/ml, and the MICs of Dutch isolates ranged from 0.125 to 2.0 microg/ ml. Difloxacin induced a concentration-dependent postantibiotic effect that lasted 0.2-3 hours in cultures with Escherichia coli, Staphylococcus intermedius, Streptococcus canis, Proteus spp., and Klebsiella pneumoniae. There was no postantibiotic effect observed against canine Pseudomonas aeruginosa. Decreasing the pH of the medium increased the MIC of Proteus mirabilis for difloxacin. The MICs of Escherichia coli and Klebsiella pneumoniae were lowest at neutral pH and were slightly increased in acid or alkaline media. At a neutral pH, most tested bacterial species were killed at a difloxacin concentration of 4 times the MIC. Similar results were obtained when these same bacteria were tested against enrofloxacin. A Klebsiella pneumoniae strain in an acidic environment was readily killed at difloxacin or enrofloxacin MIC, but at neutral pH the drug concentration had to be raised to 4 times the MIC for a bactericidal effect. After 24 hours of incubation at pH 7.1, difloxacin and enrofloxacin had similar bactericidal activity for all bacteria tested except Staphylococcus intermedius. Against S. intermedius, difloxacin was more bactericidal than enrofloxacin. 相似文献
20.
K W He J H Lin Z D Ding J H He J Y Jiang J B Hou 《Zentralblatt für Veterin?rmedizin. Reihe B. Journal of veterinary medicine. Series B》1992,39(4):299-302
Eight strains of rotaviruses isolated from diarrheal animals (4 from calves and 4 from piglets) in China were compared by serotyping with reference animal rotavirus strains (bovine NCDV, porcine OSU and simian SA-11 and human rotavirus Wa strain). Two-way cross neutralization test showed no antigenic difference between all 4 local strains of bovine rotavirus (BRV007, BRV014, HN-7 and BRV6555) and reference NCDV, so they belonged to rotavirus serotype 6 (bovine rotavirus serotype 1 or NCDV-serotype). Meanwhile, the four strains of Chinese porcine rotavirus could be determined into 2 different serotypes. One (Li99) was neutralised to a high titer with the antiserum against reference OSU virus and probably related to OSU (serotype 5 or porcine serotype 1). The other three strains (Lin71, Nan86 and Jiang150) were antigenically obviously different from Li99 and did not react with the antiserum against OSU. They were tentatively considered as porcine rotavirus serotype 2. All the strains of bovine and porcine rotavirus did not cross-neutralise with simian SA-11 and human Wa strain. There was also no antigenic relationship between bovine rotaviruses and porcine rotaviruses. 相似文献