The problems of mastitis in mares

Based on a group of 33 mares infected with mastitis, data regarding the time of appearance, the clinical symptoms and the bacteriological causes of the disease were evaluated. The cases were distributed as follows: 27.3% before delivery, 24.2% immediately after delivery (until the third day), 12.1% during the middle and late stages of lactation, 9.1% immediately after the weaning of the foal and 27.3% outside the lactation period of non-pregnant mares. The clinical picture is described. In the majority of the cases, both halves of the udder were infected. The analysis of the bacteriological results showed that from 70 isolated germ types no less than 36 were streptococci (in 25 cases beta-haemolytic streptococci). Compared to this, E. coli (3 cases), coliform germs (6 cases) and klebsiella (2 cases) were found rather seldom. The additional examination of milk samples taken from healthy mares during the first seven days after delivery showed that 13 (= 41.9%) of the mares, or 21.0% of the milk samples (n = 62), were bacterially contaminated. Here, too, the streptococci formed the majority of the germs.     

Enzootic streptococcal infection in a piglet production plant

Within a herd a syndrome affecting mainly sows occurred, with signs of apathy, anorexia or inappetence, subclinical to slight increase of body temperature and--as the prime symptom--skin hemorrhages appeared 2 to 3 days before parturition, during the lactation peak and in hot weather. By means of autopsy, histological investigations of affected skin areas, antibody and antigen evidence of Streptococcus (Sc.) MG and Sc. sanguis in blood cultures, streptococci could be found to be partly responsible for the disease mentioned above. Nearly all sows with clinical symptoms showed a significant neutrophilia and eosinophilia. Severely affected animals exhibited marked thrombocytopenia which could be due to the high levels of deoxynivalenol in the feed. A herd-specific vaccine of streptococci only temporarily succeeded.     

The use of the Auto-Microbic-System (AMS) for mastitis diagnosis in cattle

In the period of January 1987 to March 1988 15,800 quarter milk samples of dairy cows from problem herds in Lower Austria were collected and 744 streptococci strains isolated. For the classification of those 744 isolates a comparative evaluation was carried out by means of the Auto-Microbic-System (AMS), API 20 STREP and CAMP-Test. With the AMS, 360 (= 48.4%) of the 744 isolates examined could be identified as streptococci and classified as follows: 16 Sc. agalactiae; 205 Enterococci (101 Sc. faecalis, 92 Sc. faecium, 12 Sc. avium); 74 Sc. uberis; 61 Sc. of the viridans streptococci and 4 Sc. pneumoniae. The test systems showed a correlation of 91.6%. AMS and API 20 STREP could classify 4 CAMP-negative streptococci strains to Sc. agalactiae. Based on these examinations the AMS can be recommended for the identification and classification of mastitis streptococci. It can be concluded that AMS is simple to use due to the automatic cycle, and is time saving because results can be obtained between 5 to 6 hours. On the other hand, AMS requires expensive equipment.     

Defense mechanisms of the bovine mammary gland]

In the mammary gland of cattle there is a complex defense system of non-specific and specific reactions available preventing the invasion of pathogenic bacteria. Most infections occur via the teat canal, so teat canal keratin (SKK) is of particular importance in non-specific defense of the gland. The SKK serves as a physical barrier, and bacteriostatic and/or bactericidal effects of SKK lipids and proteins against certain mastitis bacteria could be demonstrated. By increasing the concentrations of lactoferrin and lysozyme in milk a reduction of mastitis frequencies could be observed. However, those high concentrations in the proteins occur only during the dry period of the cow. An improvement of the mastitis situation would also appear possible by increasing phagocytosis. The numerous trials intended to reduce mastitis by improving specific protection showed no significant success. Therefore, the most successful and cheapest means to achieve udder health remains the strict and consistent hygiene of housing, animals and mammary glands.     

Gonadotropin release and course of diseases after administration of a GnRH-analog in cattle with follicular-thecal cysts]

Twenty-five heifers and cows with follicular cysts (high level of total oestrogens, low level of progesterone in plasma) were treated with 20 or 50 micrograms buserelin i.m. 5-84 weeks after parturition. Two hours after medication an increased LH release was observed in all animals. In contrast to LH, FSH concentration was not increased in all cows. Twelve days after treatment a high progesterone concentration in plasma could be determined in 17 of 25 treated animals. Twenty cows showed oestrous symptoms 23.5 +/- 9.6 days after medication. The oestrous cycle was prolonged in 10 cows. Nineteen cows were inseminated and 14 cows became pregnant after 1-4 (phi 1.7 +/- 0.9) inseminations (73.6% of all inseminated cows and 56% of all treated cows). The differences in conception rate and in services per conception after treatment with 20 or 50 micrograms buserelin in favour of the higher dosage cannot be attributed to the medication.     

景观河道病原微生物分布特征及其与环境因子的关系

鉴于当前城市人口密集、公众与景观水体接触日益增多、水体整体环境较差的现状,为正确评价景观河道环境现状,以上海市中心城区3条不同营养状态及功能河道为例,选取2017年汛期5场连续降雨,分析了河道病原微生物的分布特征及其与环境因子的相关关系。结果表明,劣Ⅴ类水质的河道a晴天粪大肠菌群平均浓度为1.72×10~3MPN/mL,雨天为3.34×10~3MPN/mL,水质较好的河道b和河道c晴天与雨天粪大肠菌群平均浓度保持10~2MPN/mL。晴天3条河道大肠菌群平均浓度相差2个数量级,河道a为5.15×10~3CFU/mL,河道b和河道c分别为30 CFU/mL和99 CFU/mL;雨天大肠菌群平均浓度河道a为1.04×10~5CFU/mL,河道b和河道c分别为289 CFU/mL和147 CFU/mL。在变化趋势上,降雨导致粪大肠菌群和大肠菌群浓度增加,但大肠菌群浓度增加的程度明显高于粪大肠菌群。相关分析显示,3条河道内粪大肠菌群和大肠菌群与环境因子相关性存在一定差异,但基本都表现为与TN、TP和NH_3-N显著正相关,控制河道氮磷营养水平能显著抑制病原微生物增殖。     

Determination of the selenium levels of the blood plasma in newborn calves--its significance from the clinical viewpoint

In a collection of newborn calves including DRB, DSB and DFV breeds (n = 27) the plasma Selenium concentration was measured directly after parturition up until six weeks after parturition by means of neutron-activating analysis. Minimal Selenium concentration occurred on the fourth day. The values of the subsequent Selenium concentrations exceeded those immediately after parturition only slightly. The tested group could be divided into two subgroups, one of which consisted of calves with extremely low initial Selenium concentrations, whereas the animals in the others showed high levels immediately after parturition (0.019 +/- 0.004 micrograms/ml versus 0.046 +/- 0.010 micrograms/ml of plasma). The diagrams appeared to be parallel on two different levels. Nine out of 10 calves with low Selenium levels showed after parturition retarded development and/or suffered from various diseases whereas the other calves (n = 17) showed no signs of clinical disease nor alterations in the race-specific development throughout the testing period.     

葡萄牙牡蛎的净化及其低温贮藏研究

为保证生食葡萄牙牡蛎(Crassostrea angulata)的安全,在贝水比1∶10、水交换率3次/h、水温28℃、盐度28的条件下,采用流水式紫外线杀菌方法净化48 h,检测净化前后13个卫生指标的变化;净化后的牡蛎在冷藏(4℃)和冷冻(-18℃)两种条件下贮藏7 d以上;检测贮藏过程中菌落总数、大肠菌群和主要营养成分的变化。结果显示,经过48 h净化,菌落总数和大肠菌群含量均大幅下降,重金属、化学污染物等指标变化不大;两种贮藏条件下,菌落总数和大肠菌群都呈先下降再上升的变化,但始终处于安全水平内;蛋白质、脂肪、糖原含量缓慢下降,乳酸含量快速上升。研究表明,葡萄牙牡蛎在紫外线杀菌净化48 h后,至少在冷藏6 d或冷冻11 d内可以保证食品安全。     

The endocrine status of clinically conspicuous mares during the peripartum period

The aim of the present investigations was to characterize the endocrine changes in the peripheral plasma during the periparturient phase of mares with a known history of obstetrical disorders. Blood plasma samples from 9 mares (8 mares during parturition, 1 mare during abortion) were collected and the following steroid hormones were radioimmunologically determined: progesterone (P4), dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate (DHEA-S), estrone (E1), estrone sulfate (E1-S), estradiol-17 beta (E2), estriol (E3), cortisol and transcortin. In general, with the exception of cortisol, DHEA and transcortin, all steroid hormone levels declined significantly after parturition. Mean plasma concentrations of DHEA-S, the direct fetal precursor of estrone, were 6 times higher than DHEA. However, DHEA-S levels varied considerably between all mares as well as between daily values of the same mare. Levels of E1-S were found to be about thousand times higher than those of E1, E2, and E3. The rather low concentrations of E3 suggest that this hormone is mainly produced by peripheral conversion and that in the horse fetus the 16 alpha-hydroxylation of DHEA-S is lacking. Despite the fact that most of the examined mares showed signs of severe disease none of the investigated steroid hormones indicated any disturbances of gestation. It is concluded that, from the clinical point of view, serial determinations of E1-S plasma levels are the best way to prove the fetal well-being. However, it should be stressed, that even the E1-S values are no indicators for the onset of parturition or abortion.     

奶牛乳铁蛋白基因PCR-RFLP与隐性乳房炎的相关性分析

采用CMT方法检测奶牛的乳房炎发病情况,筛选120头分别设为对照组(健康奶牛)、隐性乳房炎组(试验组),每组60头,用限制性片段长度多态性(RFLP)分析技术,检测乳铁蛋白(Lf)基因启动子区域的RFLP多态性。结果表明:不同组别的奶牛Lf基因启动子区域存在RFLP多态性,说明该多态性与乳房炎存在一定关系。     

海带孢子体、配子体时期附生菌群落结构的比较

为探究海带(Saccharina japonica)生活史孢子体、配子体不同阶段的附生菌群落结构的差异,采用Illumina测序技术,分析了种海带(S1)、配子体(S2)、幼孢子体(S3)和大孢子体(S4)这4个不同阶段的藻体上附生菌16S rRNA序列,研究其附生菌群落结构。结果显示,4个阶段共识别出23门156属共244个操作分类单元(OTU)。从门分类上来说,变形菌门(Proteobacteria)在海带各阶段中均表现出较高的丰度,在S1、S2、S3和S4藻体样本中相对丰度分别达53.0%、94.3%、77.2%和36.7%,蓝细菌门(Cyanobacteria)只在S4藻体样本中表现出较高的丰度,为43.8%;从属分类上来说,假交替单胞菌属(Pseudoalteromonas)在各样本间差异较大,S2、S3和S4样本中相对丰度分别为65.00%、44.88%和25.57%,但在S1样本中仅为0.18%。各样品间附生菌群落结构差异较大,S1与S4样本相邻聚为一支,S2与S3样本为另一支。S2样本的菌群种类单一且分布不均匀,S1、S3与S4样本细菌种类丰富,但S4样本中菌群间的丰度差异较大。海带的苗种繁育阶段(S2和S3)存在褐藻酸降解菌丰度增加的趋势,孢子体阶段(S4)则具有高丰度的共生型蓝细菌。     

Coliform Organisms in Waters of Channel Catfish Ponds

Water from 48 channel catfish Ictalurus punctatus ponds at Auburn and Greensboro, Alabama, USA, usually contained less than 1,000 total coliform and 200 fecal coliform bacteria per 100 mL. There were no sources of human fecal matter to ponds. Also, the fecal coliform: fecal streptococci ratio was less than 1.0 and typical of fecal contamination by warm-blooded animals other than humans. The abundance of coliforms was greater in spring and summer than in fall and winter in catfish ponds and sportfish ponds at Auburn, Alabama. In spite of high organic matter inputs in feed, catfish ponds had no greater abundance of coliforms than sportfish ponds.     

DISTRIBUTION OF BACTERIA IN SHELLFISH CULTURE AREA AROUND QINGDAO

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菲律宾蛤仔养殖水体中大肠菌群安全限量的研究

在不同大肠菌群含量的养殖水体中,通过菲律宾蛤仔对大肠菌群的富集研究,发现菲律宾蛤仔对大肠菌群的富集量随着大肠菌群在养殖水体中含量的升高而增大,推导出的富集量公式为y=0.9254x2+17.366x-123.77。参照CAC、91/492/EEC和NSSP的标准,通过相关换算及与国内标准对比,建议菲律宾蛤仔养殖水体中大肠菌群的安全限量定为≤70cfu/100ml,生食菲律宾蛤仔养殖水体中大肠菌群的安全限量定为≤14cfu/100ml。     

真空包装淡腌青鱼品质和细菌类型及数量

在零售市场和生产企业抽取4批真空包装淡腌青鱼,对其感官、化学和细菌学品质特性进行分析,并对细菌类型和数量进行研究。结果显示,产品栅栏因子及强度存在差异,盐分含量6.68%~12.06%,平均值(9.36±2.2)%;水分活度值0.75~0.91,平均值0.82±0.07;pH值6.00~6.30,平均值6.20±0.13。栅栏因子种类和强度的不同决定产品品质的差异,感官评价均可接受,过氧化值均值为19.65±8.75 meq/kg,挥发性盐基氮均值为24.50±15.30 mg/100 g,菌落总数均值为4.45±1.15 cfu/g,大肠菌群均低于30 MPN/100 g。从4批淡腌青鱼样品分离到234株细菌,73.9%是革兰氏阳性细菌,其中36.3%是葡萄球菌,31.6%是链球菌,并出现少量微球菌和棒状杆菌;由需氧革兰氏阴性杆菌不动杆菌、摩氏杆菌和鞘氨醇单胞菌组成较小的细菌菌群约占总细菌群落的18.4%,显示水分活度、盐分含量和pH值等栅栏因子与产品细菌类型和数量呈一定相关性。     

Evaluating the quality and storage stability of fish burgers during frozen storage

ABSTRACT:   In an attempt to initiate seafood biotechnology in the Sultanate of Oman, Middle East, using underutilized fish, fish burgers from two different formulas were developed and the quality and storage stability were evaluated during storage at −20°C for 3 months. Quality and storage stability were evaluated through total aerobic and coliform bacterial count, peroxide value, protein solubility, and color. Total aerobic bacteria were reduced significantly ( P  < 0.05) by 84% and 97% of the initial load in formulas 1 and 2, respectively, whereas coliforms were completely destroyed in both formulas at the end of storage. Peroxide value increased ( P  < 0.05) but did not reach detectable levels of rancidity. Salt-soluble protein content decreased remarkably during the storage period. The L value showed good stability during storage, keeping products bright for 3 months. Fish burgers from both formulas were acceptable for 3 months at −20°C. Storage stability was rationalized by the effectiveness of freezing, and antimicrobial and antioxidant properties of food additives.     

罗非鱼皮营养成分分析及鱼皮明胶提取工艺的探讨

以罗非鱼皮为原料,对其营养成分进行分析,并通过正交试验方法探讨罗非鱼皮明胶的提取工艺,同时对明胶的理化及微生物指标进行分析。结果表明,罗非鱼皮中粗蛋白含量高达33．14％,其中胶原蛋白含量为27．8％,占其粗蛋白的83．9％;鱼皮提取明胶的适宜工艺条件为在2．5％（W／V）NaOH溶液中浸泡3．5h,然后在0．02％（V／V）HCl浸泡约3h,熬胶温度为55℃,提取得率为26．5％;所得鱼皮明胶的凝胶强度达468g,粗蛋白含量为82．46％,菌落总数为1．3×10^5CFU·g^-1,大肠菌群结果报告为阴性。     

Possible In-Plant Sources of Contamination of Lobster and Snow Crab by Listeria

Abstract

The present study was undertaken to determine potential sources of Listeria monocytogenes contamination through statistical analysis of L. monocytogenes results from lobster and snow crab samples and Listeria spp. results from environmental swabs. The objectives were (1) to compare crustacean analysis records for relationships between presence/absence of L. monocytogenes and crustacean species, year, total aerobes, staphylococci and fecal coli-form; and (2) to identify sites prone to Listeria spp. contamination. There were no significant differences in L. monocytogenes incidence between lobster and snow crab nor between five consecutive years of survey. Total aerobes and staphylococci counts were significantly associated with incidence of L. monocytogenes; fecal coliform counts were not. On surfaces in contact with the processed product, Listeria spp. were mostly found within crab crushers, drum meat separators, shucking machines, on aprons, gloves, work tables and knives. Higher incidence of Listeria spp. were found on surfaces not in direct contact with the processed product such as truck boxes, foot stools, floors, drains and employee boots and pants.     

A Preliminary Bacteriological Study of Refrigerated Channel Catfish Sperm

Abstract.— This study was designed to simulate conditions encountered routinely during refrigerated storage of channel catfish sperm. Sperm samples were stored at 4 C in non-sterile and sterile Hanks' balanced salt solution (HBSS). Non-sterile HBSS was prepared with distilled water stored for 2 wk in a plastic carboy prior to use. Observations were made on the frequency and abundance of bacteria in samples, and on changes in sperm motility and quality. Sperm samples stored in non-sterile HBSS had a complete loss of motility within 72 h. Samples maintained in sterile HBSS showed an initial decrease in motility between 48 and 72 h, and a complete loss of motility within 10 d. Quality of the sperm in each buffer decreased as motility decreased; morphologic changes and reduced motility of sperm were coincident with increased bacterial numbers. Bacteria were cultured on tryptic soy agar and Pseudomonas F agar (PFA) by spread-plating 10–μL aliquots from each sample onto bacteriologic media and incubating for 5 d. The dominant bacteria observed were members of the genus Pseudomonas , representing 67% of the total bacteria identified. The dominant pseudomonad ( Pseudomonas sp.) cultured from sperm samples stored in sterile buffer produced caseinase, lecithinase, and was β-hemolytic, whereas the dominant bacteria ( P. putida ) cultured from samples stored in the non-sterile buffers did not. Highly motile pseudomonads, present in two samples stored in sterile buffer, colonized below the surface of the PFA media at 4 C. The attributes of the bacterial contaminants that likely contributed to the decrease in sperm quality were production of extracellular enzymes, consumption of oxygen, and a high level of motility. Potential sources of degradative bacteria were commensal flora of channel catfish and the water used in preparing the storage buffer.     

The Effects of Liposomal Encapsulated Thyme Extract on the Quality of Fish Mince and Escherichia coli O157:H7 Inhibition During Refrigerated Storage

The effects of liposomal encapsulated and unencapsulated (0.3 and 0.5% w/w) thyme extract (TE) on the quality of silver carp (Hypophthalmichthys moltrix) mince during chilled storage (4 ± 1°C) were examined over a period of 15 days. The samples were analyzed by microbiological (total viable count, psychrotrophic count) and chemical (peroxide value and total volatile nitrogen) experiments. Also, the efficacy of the encapsulated extract in control in the population of Eschershia coli O157:H7 inoculated in silver carp mince was investigated. Results showed that the samples containing 0.5% of encapsulated thyme had fewer changes in peroxide value and total volatile nitrogen in comparison to other treatments (p < 0.05). Encapsulated thyme also could inhibit the growth of mesophilic and psychrotrophic bacteria in the samples compared to the control and the samples containing unencapsulated extract during the storage period. Moreover, 0.5% encapsulated TE reduced the population of E. coli O157:H7 below the acceptable level (< 2) from Day 9 until the end of the storage period. In conclusion, the results obtained from this study suggest that liposomal encapsulation may help to obtain higher antimicrobial activity in lower TE concentrations in minced fish.