规模化猪场副猪嗜血杆菌的部分生物学特性研究

为了查明流行于新疆北部部分地区部分规模化养猪场副猪嗜血杆菌的存在情况及其部分生物学特性,本试验以新疆北部地区几个规模化猪场为研究对象,从可疑副猪嗜血杆菌病病料中分离目标菌,采用微生物学与免疫学的试验手段,调查其主要流行株的生物学特性,包括生理生化特性、培养特性及分子特性,并对分离株进行了药敏试验及对小白鼠的致病性试验。试验结果表明,该地区规模化猪场中已普遍存在副猪嗜血杆菌病的感染,5株分离株对小白鼠均有较强的致病性,而且对硫酸庆大霉素和盐酸土霉素已经产生了耐药性。     

山羊伪结核病的诊治

从某羊场的山羊颈部淋巴结脓肿处分离到1株革兰氏阳性、无荚膜、无芽胞的多型性球杆菌,其对青霉素等药物有很强的抗药性。根据其形态学、培养特性、生化特性及致病性试验、动物回归试验和血清学试验结果,判定该分离菌为伪结核棒状杆菌。     

山羊伪结核病的诊治

从某羊场的山羊颈部淋巴结脓肿处分离到1株革兰氏阳性、无荚膜、无芽胞的多型性球杆菌，其对青霉素等药物有很强的抗药性。根据其形态学、培养特性、生化特性及致病性试验、动物回归试验和血清学试验结果，判定该分离菌为伪结核棒状杆菌。     

猪源益生菌的分离筛选及部分生物学特性研究

经形态、染色特性观察,从健康仔猪肠道分离出5株杆菌、1株链球菌及3株芽孢杆菌,初次筛选出产酸及抑菌效果好的杆菌、芽孢杆菌各2株,链球菌1株,经生化鉴定为乳酸杆菌2株,乳酸链球菌1株,地衣芽孢杆菌、蜡样芽孢杆菌各1株,对其进行了耐酸、耐胆汁及动物安全性试验。结果表明,筛选菌株有较强的产酸、耐酸及耐胆汁特性,对常见肠道致病菌抑制作用明显,动物使用安全,可作为猪用益生素制剂的候选菌种。     

山羊伪结核棒状杆菌的分离鉴定

从福建省不同羊场的山羊颈肩部淋巴结脓肿处分离到5株无荚膜、不形成芽孢的革兰氏阳性球杆菌,该菌在含血清的琼脂培养基上,可生长成直径1-2 mm、干燥、中央凸起、不透明、边缘不整齐、伴有β溶血环的菌落,而在普通培养基上生长不良,在麦康凯琼脂培养基上不能生长。根据其形态学、培养特性、生化特性及致病性试验和动物回归试验结果,判定所分离的5株菌为山羊伪结核棒状杆菌。     

副猪嗜血杆菌的分离鉴定及相关特性研究

本试验从2013年北京地区疑似副猪嗜血杆菌病病料中分离到19株革兰氏阴性短小杆菌,对分离株进行培养特性、荚膜染色、生化特性、血清型分型及PCR鉴定,结果显示分离的19株细菌均为副猪嗜血杆菌（Haemophilus parasuis,Hps）,分别属于血清4、5、7、12及13型。对分离株进行药敏试验及致病性试验,结果表明各分离株均有多重耐药性,且各分离株除GS-3外均有较强毒力。     

吉林地区鹅巴氏秆菌病病原分离鉴定及药敏试验

多杀性巴氏杆菌是鹅霍乱的病原体,给我国养鹅业带来了巨大的经济损失,但尚无有效的预防和控制措施.本试验对吉林地区分离的巴氏杆菌分离株的培养特性、生化特性、对化学消毒剂的敏感性、致病性、药敏试验进行了研究.结果为生化特性符合巴氏杆菌特性;1∶10 000稀释的百毒杀和1∶5 000稀释的过氧乙酸可有效杀灭该菌;对小鼠有较强致病性;药敏试验结果表明对氟苯尼考、氨苄西林、阿莫西林敏感,这将为研制巴氏杆菌灭活疫苗奠定了重要基础.     

安徽省部分地区鸭疫里氏杆菌的分离鉴定及生物学特性研究

2007年3月～12月从安徽省不同地区临床疑似鸭疫里氏杆菌感染病/死鸭中分离到26株鸭疫里氏杆菌,通过细菌形态、PCR鉴定、培养特性、生化试验和动物试验,鉴定为鸭疫里氏杆菌.各地区分离株表现为较一致的形态特征和相似的生理生化特性.对不同地区分离到的26株鸭疫里氏杆菌进行了14种常用抗菌药物的药敏试验,结果26株鸭疫里氏杆菌分离株对青霉素G、氨苄青霉素、先锋噻肟、阿莫西林和罗红霉素等几种药物敏感性较高,对庆大霉素和卡那霉素的耐受率最高,对阿米卡星、复方新诺明、链霉素和新霉素等均不同程度地产生了耐药性.本研究为安徽省鸭疫里氏杆菌病的药物防治提供了理论依据.     

河南副猪嗜血杆菌病流行病学调查

于2011年3月至2012年2月调查了河南周口、安阳、新乡、濮阳、驻马店、南阳等6个市60个猪场副猪嗜血杆菌病流行情况.采集病猪组织样品共96份进行副猪嗜血杆菌分离;对疑似菌株进行形态学观察、生化特性鉴定;最终分离鉴定到30株副猪嗜血杆菌,分离率为31.25％;对分离菌株进行血清型鉴定、致病性和药敏试验,结果表明,30株分离株中血清4型有6株,5型5株,9、11、13、14、15型各1株,其余13株未能鉴定出血清型.血清型5、13、14菌株和5个未能定型的菌株能引起小鼠全部死亡,其他菌株对小鼠致病性不强.药敏试验结果表明,63％以上的菌株除对庆大霉素、头孢喹诺高度敏感外,对其他药物敏感性不高.本调查结果将对河南副猪嗜血杆菌病的防治提供指导.     

副猪嗜血杆菌的分离鉴定和药敏试验研究

从山东某繁育猪场送检的疑似病例中分离到4株革兰氏阴性细小杆菌,通过培养特性试验和生化试验初步诊断为副猪嗜血杆菌,根据副猪嗜血杆菌16S rRNA序列设计引物,进行PCR鉴定,结果表明4株分离菌株为副猪嗜血杆菌.对4株分离菌株进行小白鼠毒力试验和药敏试验,结果表明,4株分离菌能致死小白鼠,对头孢他啶,头孢噻呋、氧氟沙星、多西环素、环丙沙星敏感,对土霉素、链霉素、林可霉素抵抗.     

Antibiotic susceptibility of bacteria isolated from cats with ulcerative keratitis in Taiwan

Objectives: To assess the antibiotic susceptibility of bacteria isolated from corneal ulcers in cats. Methods: A total of 92 cats with infected corneal ulcers were swabbed for bacterial culture and the antibiotic sensitivity of the isolates analysed. Results: Bacteria were isolated from 54 of 92 infected eyes with corneal ulcers and purulent discharge. A total of 59 bacterial isolates were obtained from the 54 ulcers. The ratio of Gram-positive to Gram-negative isolates was approximately 3:1. The most commonly isolated Gram-positive bacteria were Staphylococcus species (51 per cent of all isolates), while Pseudomonas aeruginosa (13.5 per cent of all isolates) was the most common Gram-negative bacteria isolated. The Gram-negative isolates demonstrated a greater incidence of antibiotic resistance than the Gram-positive ones. The most effective antibiotics against the isolates were ciprofloxacin, tobramycin and gentamicin, with erythromycin and lincomycin showing the greatest number of resistant isolates. Clinical Significance: Staphylococcus and Pseudomonas species were the most common Gram-positive and Gram-negative bacteria, respectively, isolated from feline eyes with ulcerative keratitis. The second-generation fluoroquinolone, ciprofloxacin and the aminoglycoside gentamicin were found to be highly effective against the majority of isolates.     

原料乳中耐冷菌群及其产酶特点

耐冷菌及其分泌的耐热酶是原料乳中常见污染物,会导致乳制品腐败。通过16S rRNA基因测序分析了分离自上海地区原料乳的耐冷菌群,以及通过平板法研究不同耐冷菌的蛋白酶和脂肪酶活力。结果表明:所有的分离株属于9个菌纲,含33个菌属,其中数量占主要的菌属是假单胞菌(Pseudomonas)(55％)、不动杆菌(Acinetobacter)(10％)和黄杆菌(Flavobacterium)(5％),其余30个菌属占所有菌株数的30％。耐冷菌产酶能力平板法实验显示,大部分的耐冷菌都有产蛋白酶或脂肪酶的能力,不同菌属之间产酶特点存在差异。假单胞菌和黄杆菌主要表现为产蛋白酶活性,克雷伯氏菌(Klebsiella)主要表现为产脂肪酶活性,而大多数的不动杆菌没有产蛋白酶或脂肪酶活性。     

Investigation of resistance of bacteria from commercial poultry sources to commercial disinfectants

Concern by consumers about food safety has resulted in increased pressure on poultry companies to develop effective sanitation programs. Salmonella isolates in hatcheries are often the same species isolated from processing plants. Resistance develops in bacteria after prolonged exposure to disinfectants. The methods available in published literature to detect the efficacy of disinfectants are labor intensive and do not consider how bacteria behave when adhered to a solid surface. We used a recently developed technique, which utilizes the actual surfaces on which the disinfectant is to be applied, to evaluate the degree of resistance to four commercially available disinfectants of 17 bacterial isolates from poultry hatcheries. We found that bacterial isolates within the same genus and species have different sensitivities to the same disinfectant. In addition, disinfectants with similar but not identical chemical formulations have different efficacies against the same bacteria.     

Trends in fluoroquinolone resistance of bacteria isolated from canine urinary tracts.

Fluoroquinolone (FQ) antimicrobial agents are used extensively in human and veterinary medicine. Widespread use of any antimicrobial agent can apply selective pressure on populations of bacteria, which may result in an increase in the prevalence of antimicrobial-resistant isolates. Antimicrobial-susceptibility data on bacteria isolated from the canine urinary tract by the University of Missouri-Columbia Veterinary Medical Diagnostic Laboratory, Columbia, MO, were used to determine whether there has been an increase in the prevalence of FQ-resistant bacteria over time. Between January 1992 and December 2001, minimum inhibitory concentrations of either ciprofloxacin (1992-1998) or enrofloxacin (1998-2001) were determined for 1,478 bacterial isolates from the canine urinary tract. The predominant bacterial species isolated were Escherichia coli (547 isolates), Proteus mirabilis (156), and Staphylococcus intermedius (147). In all, there were 13 bacterial species with more than 25 isolates each. A significant increase in the overall proportion of resistant bacterial isolates was documented from 1992 to 2001 (Cochran-Armitage test for trend, P < 0.0001). The same increase in resistant isolates was documented when either ciprofloxacin or enrofloxacin was analyzed separately (P < 0.0001 and P < 0.0002, respectively). No difference was detected in rates of bacterial FQ resistance with regard to the sex of the dog from which the bacteria were isolated. The frequency with which some bacterial species were isolated differed with the sex of the infected dog. Proteus mirabilis was found more often in females (P < 0.0001), whereas beta hemolytic Streptococcus spp., were found more often in males (P = 0.0003). Although the overall efficacy of FQ antimicrobials remained high with greater than 80% of isolates being susceptible, the data demonstrated an increase in the proportion of resistant bacteria isolated from the urinary tract of the dog.     

Isolation of putative probionts from cod rearing environment

Survival problems are encountered at early stages of intensive fish rearing and antibiotics are widely used to remedy the situation. Probiotics may provide a potential alternative method to protect larvae from opportunistic and pathogenic bacteria and promote a balanced environment. This study was designed to search for new probiotics to target this critical period in cod rearing. Potential probionts were selected from the natural microbiota of cod aquacultural environment. The selection was based on several criteria: pathogen inhibition potential, growth characteristics, strain identification, metabolite production and adhesion to fish cell lines. Our study demonstrated that 14% of screened bacteria (n=188) had antagonistic properties towards fish pathogens. The majority of these isolates were Gram-positive (81%), belonging to Firmicutes (69.2%) and Actinobacteria (11.5%) phyla based on 16S rRNA gene sequencing. Only 6 (3.2%) of 188 isolates could inhibit all three pathogens tested: Vibrio anguillarum, Aeromonas salmonicida subsp. achromogenes and Vibrio salmonicida. Differences observed in activity intensity and spectrum among inhibitory isolates emphasise the need to develop probiotic mixtures for efficient prophylactic methods. Comparison of growth behaviour of inhibitory isolates and pathogens at cod rearing temperatures, metabolite production and adhesion capacity were considered for final probiont selection. Four promising isolates that could be used as a mixed supplement to rearing water were identified as putative probiotic bacteria. This study emphasises the importance and potential of lactic acid bacteria in aquaculture.     

Antibiotic susceptibility of bacterial isolates from corneal ulcers of dogs in Taiwan

OBJECTIVES: To analyse antibiotic susceptibility of bacteria associated with ulcerative keratitis in dogs. METHODS: Bacteria isolated from 190 eyes with ulcerative keratitis were identified, and the antibiotic susceptibility of isolates was studied. RESULTS: In total, 258 species of bacteria were isolated from the 190 eyes. Of the isolates, 78 per cent were Gram-positive and 28 per cent were Gram-negative bacteria. The most commonly isolated Gram-positive bacteria in dogs were Staphylococcus spp (49 per cent), Streptococcus spp (7 per cent) and Corynebacterium spp (7 per cent); while Pseudomonas aeruginosa (7.6 per cent) and Escherichia coli (5.8 per cent) were the commonest Gram-negative pathogens. Resistance to commonly used ophthalmic antibiotics was seen in Staphylococcus, Streptococcus, Corynebacterium, Pseudomonas and Escherichia species isolates. CLINICAL SIGNIFICANCE: Isolates from dogs with corneal ulcers in Taiwan may be resistant to several commonly used ophthalmic preparations. Ciprofloxacin showed good action against most isolates, with the notable exception of Streptococcus species. Chloramphenicol or cephalothin had the best in vitro action against the Streptococcus species isolates.     

不发酵或迟发酵乳糖型禽大肠埃希菌的分离鉴定

从临床疑似大肠埃希菌感染病鸡的肝脏,分离到24株能在麦康凯平板生长但呈灰白色菌落的革兰阴性中等大小杆菌.通过IMViC试验、糖发酵试验、三糖铁斜面接种试验确定为大肠埃希菌,且其中16株为不发酵乳糖型,8株为迟发酵乳糖型.血清学试验表明,其中12株(50%)为O78抗原型,9株(37.5%)为O1抗原型,3株(12.5%)未能定型.利用PCR方法检测了该24株大肠埃希菌的F1菌毛与P菌毛基因,结果表明,其中10株(41.67%)为F1+大肠埃希菌,未发现P+分离株.药敏试验发现,所有菌株均对头孢拉定和阿米卡星敏感,部分菌株对链霉素、庆大霉素、环丙沙星、复方新诺明敏感,而对新霉素均为耐药.     

貂源肺炎克雷伯菌的分离与鉴定

本研究从疑似感染肺炎克雷伯菌(Kpn)的病死水貂病料中分离得到5株革兰氏阴性杆菌,通过对其进行细菌形态学、培养特征、生化特性和分子生物学鉴定,确认分离得到的菌株为Kpn。16S rRNA基因序列分析结果显示:该分离菌株与已知的Kpn相应序列的同源性为100%;药敏试验显示分离株对头孢曲松和舒巴坦高度敏感。动物致病性试验显示该分离株对小鼠具有较强的致病性。     

Phenotypic and genetic characterization of NAD-dependent Pasteurellaceae from the respiratory tract of pigs and their possible pathogenetic importance

Nicotinamide adenine dinucleotide (NAD)-dependent Pasteurellaceae other than Actinobacillus pleuropneumoniae and Haemophilus parasuis are frequently isolated from the respiratory tract of pigs. The taxonomic classification and relevance for pathogenicity of these bacteria deserves further attention. In the present study, 107 of these NAD-dependent isolates from the porcine respiratory tract, primarily from lungs with pathological changes, were investigated. On the basis of phenotypic criteria, such as haemolysis, urease, catalase, and indole formation as well as other fermentative activities, 50 of the isolates were assigned to Actinobacillus minor, 36 isolates to Actinobacillus porcinus and 21 isolates to Actinobacillus indolicus. However, many isolates among the three species showed fermentative activities differing from those of the respective type strain of the species. Serotyping on the basis of heat-stable polysaccharide antigens and 16 rDNA sequencing also revealed substantial heterogeneity within each of the three species although they clustered together in three distinct groups in the phylogenetic analysis. These three groups of NAD-dependent bacteria are different from, or in a borderline position, to the existing species or genera within the family Pasteurellaceae. A considerable number of isolates of these three groups were isolated in pure cultures from pneumonic lungs. Consequently, it will be necessary to critically review the opinion, that these NAD-dependent Pasteurellaceae are only "agents colonizing the mucosa". Further, taxonomic examinations of the strains within these three groups are indispensable to testing isolates for their virulence in gnotobiotic pigs.     

Microbial Safety of Chickens Raised Without Antibiotics

The purpose of the current study was to verify whether there was any validity to the claim that consumers could reduce their exposure to antibiotic-resistant bacteria by purchasing poultry products that were produced without antibiotics. Rinse samples were taken from whole carcasses from chickens grown in small flocks and marketed as antibiotic-free. Salmonella bacteria were isolated from 18.7% of all the carcasses sampled. Campylobacter bacteria were found on 96.0% of the carcasses tested. More than two-thirds (69.4%) of the Salmonella isolates were resistant to at least 1 antibiotic. The antibiotic to which the Salmonella isolates were most commonly resistant was trimethoprim-sulfa, with almost two-thirds (62.9%) of the isolates being resistant to it. Almost three-fourths (73.4%) of the Campylobacter isolates were resistant to at least 1 antibiotic. The most common antibiotic to which Campylobacter isolates were resistant was tetracycline, with almost three-fourths (72.7%) of all Campylobacter isolates being resistant to it.