Hydrogen Sulphide Producing Variants of Escherichia Coli: Widespread Occurrence in Animals and Humans within a Confined Environment

Of 178 strains of E. coli isolated on non-selective medium from faeces of pigs and humans living in the same farm 14 produced hydrogen sulphide. The H₂S producing variants all belonged to different clones suggesting that the H₂S character was plasmid-mediated. Attempts to transfer the H₂S character were not successful nor were attempts to motilize the gene by introduction of a transmissible R factor.     

硫化氢在中枢神经系统中的作用及与麻醉相关性分析

越来越多的证据表明,内源性硫化氢是一种新的气体信号分子,对中枢神经系统功能有着重要的调节和保护作用。而硫化氢在麻醉过程中的作用尚不知晓,通过对NMDA受体调节、调控神经细胞钙通道及气体信号分子与麻醉关系等方面的分析,推测硫化氢与麻醉具有一定的关联。     

毛细管气相色谱法测定猪个体日产甲烷气体量方法研究

试验建立了毛细管气相色谱法测定猪个体日产甲烷气体量的方法。甲烷气体采集后采用气密注射器即可直接上机测试。采用HP-PLOT/Q毛细柱(30 m×0.32 mm×20μm),恒温方法分离,用氢火焰离子化检测器(FID)检测。结果表明:该方法实现了猪个体甲烷气体产量的直接快速测定,线性范围为14.29～142.86 mg/m3,线性相关系数R2为0.999 6,在3个添加浓度水平上的平均加标回收率为97.42%。该方法简便、准确、线性范围宽,可用于测定甲烷气体。     

Resistance of Aujeszky disease viruses, present in the blood of pigs, to potassium thiosulphate and hydrogen chloride

A trial was conducted to study the sensitivity of the Aujeszky disease virus, present in the blood of pigs, to the effect of two preservatives: potassium thiosulphate ( K2S2O5 ) and hydrogen chloride (HCl). The sensitivity of the virus was determined on rabbits infected with pig blood containing Aujeszky disease virus with different additions of the two preservatives. As found, 0.5% of K2S2O5 and 3% of HCl are concentrations fully sufficient for the inactivation of all the viruses present in the blood. Blood preserved in this way can be used for feeding purposes in pig stocks without the hazard of introducing Aujeszky disease in healthy stocks via the blood included in feed rations.     

Concentration-time interactions in hydrogen sulphide toxicity in rats.

Concentration-time interactions were investigated in young male and female Sprague-Dawley, Long Evans and Fischer-344 rats exposed to hydrogen sulphide for two, four or six hours. Higher concentrations caused more deaths, with no significant difference for duration of exposure. A significant sex effect was noted with 30% mortality in males and 20% in females, with no significant difference among strains. Changes in weight were significant: increasing with concentration, higher in males than in females, different among strains (Fischer-344 less than Sprague Dawley less than Long Evans), and affected by duration of exposure. Lethal concentration values (LC50 and LC10) were estimated, for the pooled data set (n = 456); the probit equation was Y = -5.74749 + 3.8259X where X is log10 dose of hydrogen sulphide in parts per million. The LC50/LC10 values were 644/298 parts per million (902/417 mg m-3) respectively. Individual probit analyses were also performed for strain, hours of exposure and sex. The LC50 and LC10 values for male, female and strain were not different. Significant differences were observed among LC50/LC10 values for hours of exposure (2 h = 587/549 parts per million, 822/769 mg m-3; 4 h = 501/422 parts per million, 701/591 mg m-3; 6 h = 335/299 parts per million, 469/491 mg m-3). There was no effect of spatial position in the exposure chamber on the distribution of mortality. All rats of all strains dying had severe pulmonary edema.     

蚯蚓粪对家禽粪便堆制过程中臭气含量的影响

臭气污染不但给人们生活带来不便,而且其中含有多种有害成分,如氨气、H2S等。氨气、硫化氢、硫醇和甲硫醇等是粪便堆肥过程中主要的臭气成分。该研究探讨蚯蚓粪对鸡粪好氧堆制过程中臭气释放的影响,并且与添加微生物菌剂的阳性对照组和添加土的阴性对照组分别比较。结果表明,蚯蚓粪的除臭效果存在一定的剂量关系,30%蚯蚓粪添加组效果最好。并且蚯蚓粪能有效的抑制氨气和H2S的产生,除臭效果比阳性对照组明显。由此可见,应用蚯蚓粪是一种十分有效且环保的消除畜禽粪便臭味方法,发展前景广阔。     

Increased peroxidation of erythrocytes of stress-susceptible pigs: an improved diagnostic test for porcine stress syndrome

When incubated with solutions of hydrogen peroxide, erythrocytes of stress-susceptible pigs produced more by-products of lipid peroxidation (as measured as thiobarbituric acid-reactive substances [TBARS]) than did erythrocytes from stress-resistant pigs. Using this technique, discrimination between the 2 pig types was absolute at hydrogen peroxide concentrations of 0.9 and 1.5%. This was in contrast to other methods of identifying stress-susceptible pigs, such as osmotically induced erythrocyte lysis and the determination of plasma pyruvate kinase and creatine kinase activities, for which considerable overlap of data was observed between pig types. The increased TBARS production by erythrocytes was further evidence for the existence of an antioxidant abnormality in stress-susceptible pigs. However, because there were no discernible differences in the major blood antioxidant-related values between stress-susceptible and stress-resistant pigs, the nature of the defect remains unclear. The production of TBARS by erythrocytes when incubated with hydrogen peroxide provides an improved method for identifying stress-susceptible pigs.     

北京地区发酵床养猪方式冬夏季环境状况测试与分析

本试验在冬、夏两季选取北京某猪场有窗密闭式和塑料大棚式2种样式、漏缝地板和发酵床2种地面形式的育肥猪舍进行环境监测,综合评价不同季节、不同建筑样式下发酵床在减少猪舍有害气体、调节温湿度等方面的效果。结果表明:冬季用简易热风炉供暖的有窗密闭漏缝地板猪舍日平均温度、氨气和硫化氢的浓度与不供暖的有窗密闭发酵床舍无显著差异(P>0.05),但发酵床舍二氧化碳含量较高(P<0.05),夏季时,发酵床能显著降低舍内氨气和硫化氢浓度(P<0.05),但床面日平均温度、猪舍空气日平均温度和日最高温度均极显著地高于有窗密闭漏缝地板舍(P<0.01),猪的增重明显低于漏缝地板舍,大棚式发酵床舍空气日平均温度和日最高温度又显著高于有窗密闭发酵床舍(P<0.05),有窗密闭发酵床舍又显著高于有窗实体地面舍(P<0.05)。因此,做好冬,夏季发酵床的管理以及选择与发酵床相配套的猪舍类型和环境调控措施非常关键。     

The role of sulphide and sulphide oxidation in the copper molybdenum antagonism in rats and guinea pigs

The sulphide metabolism of rats fed molybdate up to levels of 1000 ppm molybdenum was examined and large decreases in hepatic sulphite oxidase activity observed; overall sulphide oxidation capacity was also reduced. Molybdate but not tungstate caused increases in the total plasma copper of guinea pigs but in particular the appearance of a new TCA-insoluble fraction. The effect was increased by the addition of 500 ppm sulphur as sulphide, to the molybdate diet whereas the addition of 500 ppm S as sulphate was ineffective. 100 ppm Mo was less effective as thiomolybdate (MoS4=) than as molybdate. The significance of these results in relation to the role of sulphide in the Cu-Mo-S interaction is discussed.     

某养殖场的病死野猪ASFV实时荧光PCR检测

为了进一步做好非洲猪瘟疫情防控工作,研究用实时荧光PCR法对武威市某养殖场病死野猪的猪耳朵和猪鼻拭子样品进行了非洲猪瘟病毒检测。结果显示该养殖场病死猪耳样品和猪鼻拭子样品均无Ct值,线形为直线,表明所有被检测样品均为ASFV抗原阴性。研究为严防非洲猪瘟进入威武市奠定了坚实的技术储备,也为威武市非洲猪瘟疫情防控提供了一定参考。     

Differential diagnosis of classical swine fever and border disease: seroepidemiological investigation of a pestivirus infection on a mixed sheep and swine farm.]

During recent years neutralizing antibodies against Border Disease Virus (BDV) were found repeatedly in German pig herds. Consequently there was a demand for a differential diagnostic system. A permanent sheep cell line and BDV reference strain Moredun were chosen and were applied in a could be used case study. A pestivirus could be isolated from piglets on a mixed farm and was characterised as 'non-Classical Swine Fever' (CSF) by using monoclonal antibodies. Due to a CSF suspicion the pig herd was destroyed immediately. Serum samples of sheep from the same farm were used for further characterisation of the new virus isolate. A neutralization test of the sheep sera was performed against different pestiviruses and the new isolate. Neutralizing antibody titres against the new virus pig isolate were significantly higher than against all other pestiviruses. BDV strain Moredun recognised the antibodies clearly, whereas CSF viral strain Alfort 187 and several isolates of bovine viral diarrhoea virus (BVDV) strains scored the lowest cross reaction.     

The Genetic Diversity and Phylogenetic Relationships of Five Guangxi Pig Breeds and Three Exotic Pig Breeds by Analysis of mtDNA D-loop Sequences

In order to compare the genetic diversity and phylogenetic relationships between Guangxi pig breeds and three exotic pig breeds,one pair of primers was used to amplify 85 mtDNA D-loop sequences of five Guangxi pig breeds (Bama Xiang pig,Dongshan pig,Guizhong spotted pig,Luchuan pig,Huanjiang Xiang pig),and we downloaded 45 mtDNA D-loop sequences of three exotic pig breeds (Duroc,Yorkshire,Landrace) from GenBank.Then the haplotype,genetic diversity and phylogenetics analysis were carried out.The results showed that 38 haplotypes were identified in 130 sequences,and the mean distances among Guangxi pig breeds were smaller than that among Duroc,Landrace and Guangxi pig breeds.The NJ phylogenetic tree classified all samples into two clusters.One contained all of Guangxi pig breeds and partial Yorkshire,the other was composed wholly of exotic pig breeds,which mean there were two distinct maternal origins.In the cluster of Guangxi pig breeds,Luchuan pig were clustered,and the others were rather dispersive.It indicated that Luchuan pig had simple maternal bloods,and the other breeds had complex maternal bloods,and they had gene flow with each other.The maternal pig resources in Guangxi were not affected by the introduction of exotic pig breeds,and they were still suitable for use as a female parent in their development and utilization.     

Long-term lack of transmission of Aujeszky's disease virus (ADV) in a chronically infected Swedish weaner pig producing herd

A cohort of 53 swine seronegative to Aujeszky's disease virus (ADV) was monitored in a 1 year study of a chronically infected commercial Swedish weaner pig producing herd. Serum samples were acquired from all 134 adult swine and analyzed by enzyme-linked immmunosorbent assay (ELISA). Animals testing negative, along with introduced replacement gilts, were followed serologically every second month. Movements of animals were recorded for 319 days and exposure to seropositive animals was calculated for each seronegative pig in the cohort. The accumulated daily pig contact between the 53 ADV-non-infected swine and 43 infected swine was 35 660 days and the median number of days in contact for the non-infected swine with infected was 222. Despite the frequent contact with seropositive pigs, no seronegative animals seroconverted during the first 11 months of observation. Forty-six of 53 pigs seroconverted after a clinical outbreak during the twelfth month of observation.     

Genetic structure of pig breeds from Korea and China using microsatellite loci analysis

To understand molecular genetic characteristics of Korean pigs, the genetic relationships of nine pig breeds including two Korean pigs (Korean native pig and Korean wild pig), three Chinese pigs (Min pig, Xiang pig, and Wuzhishan pig), and four European breeds (Berkshire, Duroc, Landrace, and Yorkshire) were characterized from a 16-microsatellite loci analysis. The mean heterozygosity within breeds ranged from 0.494 to 0.703. Across multiple loci, significant deviation from Hardy-Weinberg equilibrium was observed in most pig breeds, except for two Chinese pigs (Min pig and Wuzhishan pig). This deviation was in the direction of heterozygote deficit. Across population loci, 36 of 144 significantly deviated (P < 0.05) from Hardy-Weinberg equilibrium. The mean FST, a measure of genetic divergence among subpopulations, of all loci indicated that 26.1% of total variation could be attributed to the breed difference. Relationship trees based on the Nei's DA genetic distance and scatter diagram from principal component analysis consistently displayed pronounced genetic differentiation among the Korean wild pig, Xiang pig, and Wuzhishan pig. Individual assignment test using a Bayesian method showed 100% success in assigning Korean and Chinese individual pigs into their correct breeds of origin and 100% exclusion success from all alternative reference populations at P < 0.001. These findings indicate that the Korean native pig has been experiencing progressive interbreeding with Western pig breeds after originating from a North China pig breed with a black coat color. Considering the close genetic relationship of Korean pigs to the Western breeds such as Berkshire and Landrace, our findings can be used as valuable genetic information for the preservation and further genetic improvement of the Korean native pig.     

Lactobacillus species in drinking water had no main effects on sulphur compounds from manure,egg quality,and selected serum parameters of second cycle hens

ABSTRACT

1. The aim of this study was to investigate the effects of a combined probiotic product (Lactobacillus paracasei, L. plantarum, and L. rhamnosus) on egg quality, sulphur compounds in manure and serum biochemistry of second cycle hens.

2. A total of 48 White Leghorn hens, at 52- to 54 weeks of age, were treated in a completely randomised design with water containing 0 or 1.8375 × 10¹⁰ cfu/l of probiotics for 8 weeks.

3. Probiotic supplementation did not affect egg quality. Albumen height and Haugh units were in general lowest in week 2 and highest in week 6.

4. For manure and serum parameters, water with or without probiotics produced statistically similar effects. An interacting trend for increasing concentrations of methyl mercaptan in manure was noted for probiotics x week, and should be further investigated. The week of supplementation significantly affected hydrogen sulphide, dimethyl sulphide, and triglycerides.     

Herd prevalence of Salmonella spp. in Danish pig herds after implementation of the Danish Salmonella Control Program with reference to a pre-implementation study

The problems addressed are: (1) comparison of prevalences of Salmonella spp. in different herd types in the Danish pig population after implementation of the Danish Salmonella Control Program (DSCP), and (2) to make a reference to a study from 1993/1994 (pre-implementation) with a discussion of possible biases when diagnostic methods differ slightly. The objectives were to present the prevalences of Salmonella spp., Salmonella Typhimurium, and multiresistant S. Typhimurium DT104 in Danish pig herds in 1998. Further, to discuss how herd prevalences may be compared to a previous study.A bacteriological study in 1998 comprised: (a) a random sample of slaughter pig producing herds (N=1962); (b) a random sample of farrow-to-grower (sow) herds (N=305); and (c) all breeding and multiplying (genetic) herds (N=366). A previous bacteriological study on Salmonella presence in 1993/1994 served as a model for the present study. The results of the study were that multiresistant S. Typhimurium DT104 was detected in one herd producing slaughter pigs. The herd apparent prevalences (HAPs) of Salmonella spp. were 11.7, 16.7 and 11.4% in genetic, sow, and slaughter pig herds, respectively. The conclusion of the study was that prevalence of multiresistant S. Typhimurium DT104 was low in the examined slaughter pig herds. The herd true prevalence (HTP) of Salmonella spp. in pigs had declined from before the start of the DSCP in 1993/1994 to 4 years later (1998).     

The development of a real-time PCR to detect pathogenic Leptospira species in kidney tissue

A LightCycler real-time PCR hybridization probe-based assay that detects a conserved region of the16S rRNA gene of pathogenic but not saprophytic Leptospira species was developed for the rapid detection of pathogenic leptospires directly from processed tissue samples. In addition, a differential PCR specific for saprophytic leptospires and a control PCR targeting the porcine beta-actin gene were developed. To assess the suitability of these PCR methods for diagnosis, a trial was performed on kidneys taken from adult pigs with evidence of leptospiral infection, primarily a history of reproductive disease and serological evidence of exposure to pathogenic leptospires (n=180) and aborted pig foetuses (n=24). Leptospire DNA was detected by the 'pathogenic' specific PCR in 25 tissues (14%) and the control beta-actin PCR was positive in all 204 samples confirming DNA was extracted from all samples. No leptospires were isolated from these samples by culture and no positives were detected with the 'saprophytic' PCR. In a subsidiary experiment, the 'pathogenic' PCR was used to analyse kidney samples from rodents (n=7) collected as part of vermin control in a zoo, with show animals with high microagglutination titres to Leptospira species, and five were positive. Fifteen PCR amplicons from 1 mouse, 2 rat and 14 pig kidney samples, were selected at random from positive PCRs (n=30) and sequenced. Sequence data indicated L. interrogans DNA in the pig and rat samples and L. inadai DNA, which is considered of intermediate pathogenicity, in the mouse sample. The only successful culture was from this mouse kidney and the isolate was confirmed to be L. inadai by classical serology. These data suggest this suite of PCRs is suitable for testing for the presence of pathogenic leptospires in pig herds where abortions and infertility occur and potentially in other animals such as rodents.     

Some problems associated with the identification of Corynebacterium equi

One hundred strains of Corynebacterium equi were examined using standard laboratory procedures. Variations in colonial morphology were noted. The ability to reduce nitrate and to produce urease was shown to be valuable for confirmation of identification of C. equi. Production of hydrogen sulphide was a variable characteristic of C. equi. It is concluded that for those situations where the source of the organism gives no clue as to its identify, positive identification of C. equi may be difficult because of variability in colonial appearance and biochemical reactions.     

Analysis of the Cecum Microbial Diversity of Different Pig Breeds by Illumina Amplicon Sequencing of 16S rDNA Tag

To study the diversity and composition of the bacterial community from cecum samples from Yacha pig, Qingyu pig and Wujin pig, the investigation was designed to reveal mechanism of roughage resistance. Illumina amplicon sequencing of 16S rDNA Tag was used to analyze the cecum microbial diversity of Yacha pig, Qingyu pig and Wujin pig at 90 kg liveweight. The results indicated that the core flora of the three breeds were Bacteroidetes and Firmicutes at the phylum level and Prevotella and Bacteroides at the genus level. Meanwhile bacteria associated with cellulose decomposition were found in all three breeds, in which the number of Fibrobacter and Clostridium in Yacha pig were significantly higher than that in Qingyu pig and Wujin pig (P<0.05),and the number of Prevotella in Yacha pig was significantly higher than that in Wujin pig (P<0.05). The number of Bacteroides in Qingyu pig was significantly higher than that in Yacha pig (P<0.05).The number of Spirochaetes in Qingyu pig was significantly higher than that in Wujin pig (P<0.05). It could conclud that the composition of the cecum bacteria community was similar in above pig breeds, but there were significant differences in distribution and quantity. According to analysis of microbial related to cellulose digestibility, Yacha pig was the strongest among the three breeds, followed by the Qingyu pig and Wujin pig.     

Chemical and organoleptic changes in poultry meat resulting from the growth of psychrophylic spoilage bacteria at 1 degree C. 3. Glutamine, glutathione, tyrosine, ammonia, lactic acid, creatine, carbohydrate, haem pigment and hydrogen sulphide

Changes in breast muscle (pectoral proper and supra coracoid) and leg muscle (muscles covering the femur, fibula and tibia) attributable to the growth of microorganisms at 1° C were generally small and in case of lactic acid, creatine‐creatinine and myoglobin could not be detected. “Tyrosine”, ammonia and hydrogen sulphide increased and glutamine decreased, the magnitude of the change varying with the organism. Glutathione decreased rapidly in aseptically minced muscle at 1° C.