Susceptibility of Salmonella isolated from fish feed factories to disinfectants and air-drying at surfaces

The objective of this work was to determine whether persistence of certain Salmonella isolates in fish feed factories involved enhanced resistance to disinfectants or air-drying. Salmonella isolates known to be persistent in fish feed factories and Salmonella isolates from other origins were tested for their sensitivity to nine disinfectants by using a suspension test. More than 5log(10)reduction in viable count for all isolates was only achieved by two of the disinfectants at 80% of the lowest recommended user concentration. However, Salmonella isolates from fish feed factories were not more resistant to disinfectants compared to Salmonella from other origins. For four of the disinfectants, presence of fish feed had a more adverse effect on disinfection efficacy compared to the protein bovine serum albumin (BSA). In general, the Salmonella isolates were more resistant to disinfection than Escherichia coli DSM 682, a strain recommended in testing of disinfectants. The Salmonella isolates were also tested for their ability to survive air-drying at stainless steel surfaces, but there were no differences in survival of isolates from fish feed factories compared to isolates of other origin. In conclusion the Salmonella isolates from fish feed factories were not particularly resistant to disinfection or air-drying at surfaces. The data show that disinfectants to be used against Salmonella should be thoroughly tested and selected, since not all disinfectants appear to be effective against Salmonella.     

炎热季节养殖场消毒措施探析

消毒是养殖场必须重视的一个防疫环节,尤其是在炎热的夏季,细菌、病毒易于孳生,规模养殖场更要重视消毒工作。消毒药品的选择、使用方法以及消毒间隔时间等都是影响消毒效果的因素。介绍了在炎热季节养殖场消毒过程中常见的一些不合理、不规范的用药现象,并提出较合理的用药方法,目的在于指导养殖场在生产过程中合理使用消毒药,做好日常消毒工作,为养殖场的生产保驾护航。     

Disinfection of foot-and-mouth disease and African swine fever viruses with citric acid and sodium hypochlorite on birch wood carriers

Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contaminated agriculture facilities to return to food production. Wood surfaces are prevalent at these locations, but there is no standardized method for porous surface disinfection; commercial disinfectants are only certified for use on hard, nonporous surfaces. To model porous surface disinfection in the laboratory, FMDV and ASFV stocks were dried on wood coupons and exposed to citric acid or sodium hypochlorite. We found that 2% citric acid was effective at inactivating both viruses dried on a wood surface by 30 min at 22°C. While 2000 ppm sodium hypochlorite was capable of inactivating ASFV on wood under these conditions, this chemical did not meet the 4-log disinfection threshold for FMDV. Taken together, our data supports the use of chemical disinfectants containing at least 2% citric acid for porous surface disinfection of FMDV and ASFV.     

Efficacy of five commercial disinfectants and one anionic surfactant against equine herpesvirus type 1

We investigated the influences of various reaction conditions on equine herpesvirus type 1 (EHV-1) disinfection by 5 commercial disinfectants (3 quaternary ammonium compounds [QACs] and 2 chlorine-based disinfectants) and 1 anionic surfactant. QACs at their highest recommended concentrations had no virucidal effect on EHV-1 with a 10-min reaction time at 0°C or a 1-min reaction time at room temperature. Chlorine-based disinfectants achieved EHV-1 disinfection with a 10-min reaction time at −10°C or a 30-sec reaction time at room temperature. In the presence of 5% fetal bovine serum, QACs (except for benzalkonium chloride) showed more stable virucidal effects than did chlorine-based disinfectants. The virucidal effect of the anionic surfactant was almost equivalent to that of the QACs.     

规模化鸡场消毒剂的筛选与消毒效果评价

为评价消毒剂对规模化鸡场的消毒效果,采用有限稀释法和茵悬混合液定量杀菌试验分别测定50 g/L苯扎溴铵(A)、20 mL/L戊二醛溶液(B)、100 g/L聚维酮碘(C)、100 g/L癸甲溴铵(D)和过硫酸氢钾复合物粉(E)5种消毒剂对大肠埃希茵最小杀菌浓度(MBC)和杀灭对数值;采用带鸡消毒试验对5种消毒剂进行现场...     

消毒剂对生物发酵床中有益菌数量与酶活性的影响

采用复合碘溶液(第1组)、复合酚溶液(第2组)、复方戊二醛溶液(第3组)和二氯异氰脲酸钠粉(第4组)4种养猪场常用消毒剂,按说明书常规消毒用量浓度对发酵床进行消毒,研究消毒剂对垫料中的益生菌、温度、部分酶活性的影响.结果:第1、4组消毒剂实施消毒后,对垫料中添加的枯草芽孢杆菌、放线菌的活菌数无不良影响(P＞0.05),...     

Laboratory investigation of the chemical disinfection against different developmental stages of the housefly (Musca domestica Linnaeus, 1758)

Possibilities for disinfection of the developmental stages from the housefly (Musca domestica) were investigated under laboratory conditions. The developmental stages (eggs, larvae I, II, III, pupae and adults) were sprayed with solutions of disinfectants on the basis of p-chlorine-m-cresol and o-phenylphenol at different concentrations (0.025%-3%). The effectiveness of both disinfectants was established by determining the emergence rate of eggs and pupae and of the live evidence of larvae and adults. Transmission electron microscopic investigations of the cover of the eggs revealed the bactericidal effect of both disinfectants. These results show the necessity of extending its use also to noxious arthropods.     

三类常用消毒剂对非洲猪瘟病毒灭活效果的评价

为评价戊二醛类、酚类、含氯类常用消毒剂对非洲猪瘟病毒(ASFV)的灭活效果,参考OIE参考实验室相关操作流程,基于畜禽栏舍、运载工具、器具消毒目的,根据说明书标明的浓度范围选择低、中、高3个工作浓度,与ASFV分别在4℃和20℃条件下作用30 min,10倍连续稀释后接种猪肺泡巨噬细胞,同时加入猪红细胞,培养观察红细胞...     

市售5种消毒剂对舍饲鸭场的杀菌效果评价

为了解贵州省某舍饲鸭场环境中菌落分布情况以及市售五种常用消毒剂(苯扎溴铵、月苄三甲氯铵、复方戊二醛、戊二醛癸甲溴铵、聚维酮碘)的灭菌效果。通过采集鸭场空气、粪便、垫料、饮水样本进行菌落总数测定;分别配制最小杀菌浓度的苯扎溴铵、月卞三甲氯铵、复方戊二醛及戊二醛癸甲溴铵4种消毒剂,采用雾线、喷洒消毒方式对舍饲鸭场空气、漏缝地板、料槽、蛋框及运输车车轮进行现场消毒;配制最小杀菌浓度的聚维酮碘,采用涂抹方式对鸭蹼部皮肤进行涂抹消毒;最后分别测定鸭场空气、漏缝地板、料槽、蛋框、运输车车轮及鸭蹼样本消毒前后的菌落总数并计算5种消毒剂对细菌的杀菌率。结果显示：舍饲鸭场空气菌落总数为3.79×10⁴ CFU/m³,超出NY/T 388-1999畜禽场环境质量标准规定数值(25000 CFU/m³);粪便菌落总数为2.67×10⁷ CFU/g,超出GB18596-2001畜禽养殖业污染物排放标准规定数值(1.03×10⁶CFU/g);垫料菌落总数为3.7×10⁶CFU/g,超出NY/T1167-2006畜禽场环境质量及卫生控制规范规定的清洁土壤数值(5×10⁴CFU/g);饮水菌落总数为12 CFU/mL,符合GB 5749-2006生活饮用水卫生标准(100CFU/mL)。5种消毒剂对鸭场进行现场消毒试验,复方戊二醛对漏缝地板、蛋框、运输车车轮的细菌杀菌率最高,分别为96.78%、81.31%、87.5%;戊二醛癸甲溴铵对鸭舍空气、料槽的细菌杀菌率最高,分别为34.85%、74.35%;聚维酮碘对鸭蹼部皮肤细菌杀菌率为72.45%;4种消毒剂对漏缝地板、料槽、蛋框、运输车车轮消毒效果良好,对空气的消毒效果不理想;聚维酮碘对鸭蹼部皮肤消毒效果不理想。结果表明：该舍饲鸭场存在大量超过国标菌落总数的安全隐患,通过对该鸭场微生物菌落计数及现场消杀试验,在一定程度将菌落总数控制在了合理范围。研究结果旨在为掌握舍饲鸭场微生物菌落分布情况,制定舍饲鸭场消毒程序以及科学防控养鸭场细菌性疾病提供参考依据。     

二氧化氯在猪场的应用及前景

非洲猪瘟疫情暴发之后,猪场很重视消毒工作。但是如何正确选择和使用消毒药,还存在一些误区。二氧化氯作为第四代杀菌消毒剂,目前在猪场还没有得到广泛的使用,文旨在介绍二氧化氯的特性,杀菌机理,以及在猪场如何正确的使用二氧化氯,从而达到高效,安全,有效消毒的目的,简述二氧化氯在猪场的应用前景。     

七类消毒剂对非洲猪瘟病毒荧光定量PCR检测结果的影响

为评价戊二醛、酚、含碘类等常用消毒剂消毒后对非洲猪瘟病毒荧光定量PCR检测结果的影响,基于畜禽栏舍、运载工具、器具消毒及皮肤黏膜消毒目的,按消毒剂说明书推荐选择不同工作浓度,分别与不同滴度的非洲猪瘟病毒培养物于20℃条件下作用30 min后,采用荧光定量PCR方法检测作用后产物。结果显示,与对应的阳性对照组相比,含氯类(二氯异氰尿酸钠)、过硫酸氢钾类、二氧化氯类消毒剂,消毒后对荧光定量PCR检测结果影响最显著,检测Ct值显著上升或检测不到;戊二醛类、含碘类(主要成分聚维酮碘)消毒剂,核酸降解能力相对较弱,检测Ct值稍有上升;酚类、季铵盐类、含碘类(主要成分碘、磷酸、硫酸)类消毒剂,检测Ct值基本无变化。本研究评价了7类常用消毒剂消毒对非洲猪瘟病毒荧光定量PCR检测结果的影响,可为防控实践中科学、客观评价分析消毒效果提供技术参考。     

两种消毒剂对流感病毒灭活效果的对比研究

采用Klein-Defors悬浮杀灭与感染试验方法，研究“卫可”、“卫康”两种消毒剂在不同浓度下，分别与流感H51N1和H9N2亚型病毒作用5min和10min，对流感病毒的灭活作用。结果表明：这两种消毒剂在相同或不同的浓度范围内。对病毒的杀灭率是有区别的。尽管每种消毒剂在本身稀释浓度范围内都有较好的杀毒效果，但在应用中也应考虑其他因素的影响。因此，我们推荐使用该消毒剂的工作浓度为100％杀灭病毒的稀释度。这将为其临床应用提供依据，对环境消毒和防止流感爆发具有参考价值。     

红三叶新品系无菌苗培养体系优化

以红三叶(Trifolium pratense L.)新品系为材料,对无菌苗培养的种子消毒方法和培养基组成进行研究,以期为红三叶新品系组培再生体系、分于育种及抗病性研究提供基础依据。结果表明:0.1%HgCl₂,3%NaClO和15%H₂O₂消毒不超过15 min,对红三叶新品系种子发芽率没有显著影响,但消毒效果存在较大差异。红三叶种子消毒的最佳方法为75%酒精预处理,0.1%HgCl₂消毒10 min,发芽率可达89.44%,并彻底无污染。最适培养基为1/4MS+1.5%蔗糖,不添加激素,pH6.0,发芽率可达85.78%,无菌苗生长良好。培养基中无机盐的含量是影响红三叶种子发芽率和无菌苗生长的关键因素。琼脂培养基培养比滤纸培养的无菌苗子叶和下胚轴出愈率显著提高,但不同组分琼脂培养基的无菌苗出愈率无显著差异。     

Inactivation of canine parvovirus by disinfectants and heat

The resistance of canine parvovirus (CPV) to inactivation by chemical and thermal means was investigated. CPV with and without extraneous protein was tested against 15 commonly used disinfectants at room temperature. The titres of CPV remaining after 5 minutes disinfection time were greater than or equal to those remaining after 30 minutes regardless of the presence or absence of protein. Disinfection of CPV was accomplished more quickly and at lower concentrations of disinfectants when extraneous protein was absent. Halogen compounds, aldehydes and sodium hydroxide were the most acceptable CPV disinfectants. The presence of protein interfered with the two most frequently recommended CPV disinfectants—sodium hypo-chlorite and formaldehyde. The resistance of CPV to inactivation by heat depended on the temperature and the duration of heating. Boiling (100°C) rapidly inactivated CPV. The virus was more resistant to lower temperatures. Detectable infectivity remained after 7 hours at 80°C and 72 hours at 56°C. At both 37°C and room temperature there was no significant change in infectivity titres over 72 hours.     

Action of disinfectants on canine coronavirus replication in vitro

Canine coronavirus (CCoV) is responsible for enteric disease in pups. Infected dogs generally have a rapid recovery, so the virus is highly contagious and the spread of infection is difficult to control. Chemical disinfectants have been widely used in human disease-control programmes to prevent viral infectious diseases from spreading, but to date, there are no studies in the literature on the sensitivity of CCoV to chemical biocides. The present study investigated the sensitivity of CCoV to disinfectants currently used for prophylaxis in kennel and dog breeding locations. The effects of three agents: alkyl-dimethyl-benzyl-ammonium chloride, benzalkonium chloride and didecyl-dimethyl-ammonium chloride, on the infectivity titre of CCoV in A72 cell lines, were studied at different concentrations. Although they may regard a small number of agents, the findings showed that the sensitivity of CCoV to disinfectants varies and the differences are dose correlated. In general, virus inactivation implies a permanent loss of infectivity which can be evaluated in suspensions and hand disinfection tests.     

Comparison of the bacteriostatic effects of quaternary ammonium compounds and their combinations on a dairy farm environment and the microbial contamination of dairy products

Disinfection is key for controlling microbial contamination and ensuring the safe production of milk and dairy products. In this study, we developed a new disinfection method using quaternary ammonium surfactant N-dodecyl-2-(pyridin-1-yl) acetamide chloride as the main component to form a bactericidal complex with either chlorhexidine acetate or glutaraldehyde, and we evaluated the bactericidal effects, safety, and clinical application value of the compound disinfectants. An in vivo acute oral toxicity assay in mice showed an LD₅₀ > 5000 mg/kg body weight without abnormality in pathological tissue sections. Comparison with commercially available products also showed that they have outstanding bactericidal effects. Clinical trials proved that the compound disinfectants have excellent bactericidal effects on the air and ground of the dairy farm and on the skin of cattle, especially in a dairy farm environment. Our findings confirm that the new compound disinfectants have excellent bactericidal performance and are safe to use as disinfectants to prevent mastitis and contamination of the cattle farm environment.     

克氏原螯虾人工诱导繁殖的初步研究

为提高克氏原螯虾育苗过程中亲虾的成活率,利用福尔马林、高锰酸钾、食盐、聚维酮碘和溴氯海因对购进的亲虾进行消毒试验,结果表明:经上述5种常用药物浸泡消毒后,亲虾成活率分别比对照组提高25%、40%、5%、10%和15%,对亲虾采用高锰酸钾消毒效果较好;为提高克氏原螯虾亲虾的抱卵率,采用盐水诱导、雌虾去单侧眼柄诱导、盐水诱导+雌虾去眼柄双重诱导3种不同人工诱导方式诱导亲虾,促使其性腺发育,试验结果显示,经3种诱导方式诱导的亲虾抱卵率分别比对照组提高20%、31%和39%,双重诱导的平均产卵率高于单因子诱导。     

新型蚕体蚕座消毒剂复方蚕座净的研究

从医药卫生防疫消毒剂、农药杀菌剂和化工防霉剂中,经过抑菌效果多重筛选、滤纸条交叉法,测定各药液搭配是否增效或拮抗;消毒效果生物试验、蚕体蚕座消毒防病试验等筛选出对家蚕病毒病、细菌病、真菌病、微粒子病等四大类传染性蚕病病原均有灭活作用的杀菌广谱、高效、低毒、安全、无腐蚀性及化学性稳定的复合剂型蚕体蚕座消毒剂。经2年农村生产中试,对降低蚕期发病率、死笼茧率,提高上茧率和原蚕繁殖系数等均取得显著的效果。     

Development and application of a standardized assay for chemical disinfection of coccidia oocysts.

The development and application of a standardized model for testing of anticoccidial disinfectants are described. Due to its economic impact, tenacity of oocysts, and reproducibility of the course of infection Eimeria tenella has been chosen as test organism. Oocysts of the Houghton strain were more susceptible to disinfection with 4% TP4 (Preventol) than oocysts of a field isolate (FI 292/1) as determined by sporulation inhibition and lysis. Scoring of intestinal lesions and of oocyst numbers in mucosal scrapings in chicken infected with various doses of oocysts were found unsuitable for assessment of disinfectants. Because strain differences were observed only Houghton strain oocysts were applied for further testing. Guidelines for standardized in vivo testing of disinfectants have been stipulated by the German Veterinary Society (DVG) on the basis of these studies. When applied for testing of Neopredisan (NP) in two separate laboratories similar results were obtained. Inhibitory activity (IA; proportion of inactivated oocysts) of 92.9 and 90.6% were calculated for 3% NP and of 95.2 and 96.8% for 4% NP after treatment with the disinfectant over 120 min. According to the guidelines IA of at least 95% is required for certification of sufficient disinfecting efficacy by the DVG.     

Phenotypes and genotypes of campylobacter strains isolated after cleaning and disinfection in poultry slaughterhouses

Campylobacter is responsible for human bacterial enteritis and poultry meat is recognised as a primary source of infection. In slaughterhouses, cleaning and disinfection procedures are performed daily, and it has been suggested that disinfectant molecules might select for antibiotic resistant strains if shared targets or combined resistance mechanisms were involved. The aim of the study was to investigate if cleaning and disinfection procedures in poultry slaughterhouses select for antibiotic resistance in Campylobacter jejuni and C. coli and to determine the genotypes of isolates collected after cleaning and disinfection. Nine sampling visits were made to four French slaughterhouses. Samples were collected from transport crates and equipment surfaces, before and after cleaning and disinfection. Minimal inhibitory concentrations of the recovered C. jejuni and C. coli isolates to six antibiotics and two disinfectants were measured. The C. jejuni isolates collected from equipment surfaces after cleaning and disinfection were subjected to PCR-RFLP typing. Twenty-five C. jejuni isolates and 1 C. coli were recovered from equipment surfaces after cleaning and disinfection during five visits to three different slaughterhouses. Those isolates did not show an increased resistance to the tested antibiotics compared to isolates collected before cleaning and disinfection. Only one or two genotypes were recovered after cleaning and disinfection during single visits to each slaughterhouse. This observation suggests that such genotypes may be particularly adapted to survive cleaning and disinfection stress. Understanding the survival mechanisms of Campylobacter should facilitate the implementation of better-targeted strategies and reduce the public health burden associated with Campylobacter infection.