Antibacterial Effects of Chinese Herbal Medicines against Streptococcus iniae in Oreochromis niloticus

In this study, the antibacterial effects of Chinese herbal medicines against Streptococcus iniae in Oreochromis niloticus were investigated by drug sensitiv- ity test. The results indicated that Streptococcus in/ae was extremely sensitive to Calla Chinensis, Fructus Hippophae and Fructus Murne, highly sensitive to Sappan Lignum, Pericarpium Granati, Folium Eucalypti and Radix Scutellariae, moderately sensitive to Rh/zoma Coptidis, Radix et Rhizoma Rhei, Flos Caryophyllata, Cortex phellodendri and Rabdosia serra （ Maxim. ） Hara, and insensitive to Herba Portulacae , Herba Houttuyniae , Polygonum hydropiper L. , Herba Menthae , Radix Glycyrrhizae , Pericarpium Citri Reticulatae , Herba Andrographitis and Rhizoma Acori Tatarinowii. Chinese medicinal herbs which Streptococcus iniae was extremely sensitive or moderately sensitive to were selected and prepared into three Chinese herbal medicine formulae for medicated bath of Oreochromis niloticus infected arti- ficially with Streptococcus iniae. The results showed that medicated bath elicited therapeutic effects on infected Oreochromis niloticus. Formula II exhibited the best therapeutic effect with an effective percentage of 90%.

Particle Sizes and Antibacterial Activity of Radix Astragalus and Radix Isatidis Ultrafine Powders

Using 9200 laser particle size analyzer and KYKY-2800 scanning electron microscope, particle sizes and cellular morphology of Radix Astragalus and Radix Isatidis ultrafine powders were observed. According to the results, the particle size of 89. 1 % of Radix Astragalus ultrafine powders ranged from 1.729 [xm to 44.938 ｜xm, Z ）50 =4.368 ｜xm; the particle size of 93.411% of Radix Isatidis ultrafine powders ranged from 1.510 [xm to 44.938 ｜xm, Z ）50 = 8 .7 2 6 [xm. Radix As-tragalus and Radix Isatidis ultrafine powders were pulverized completely without intact cellular morphology. The antibacterial activity of Radix Astragalus and Radix Isatidis ultrafine powders against chicken-derived E. coli （078） was investigated. The results indicated that Radix Astragalus and Radix Isatidis ultrafine powders exhibited higher antibacterial activity against chicken-derived E. coli （078 ） compared with the corresponding coarse powders. This study laid a solid foundation for the development and application of Chinese medicine ultrafine powder preparations.

Expression of Nucleoprotein Gene of CTN Strain Rabies Virus from China in <i>E. coli </i>with Antigenicity

The nucleoprotein (NP) gene of rabies CTN strain isolated from China was recombined into pMal-c2x. The antigenicity of the recombined MBP-NP fusion proteins was examined by western blotting and by enzyme linked immunosorbent assay (ELISA). The results demonstrated that the recombined protein possesses predominant antigenicity.

Isolation and Identification of a Pathogenic E.coli Strain Causing Diarrhea in Foxes

[Objectives] The study aimed to identify the pathogenic E. coli strain that caused diarrhea in foxes and to analyze its drug sensitivity.[Methods] A pathogenic E. coli strain was isolated from dead foxes with diarrhea. By conventional bacterial isolation and culture, morphological observation, pathogenicity test and K-B disc method, the isolated strain was identified as pathogenic E. coli .[Results] The isolated pathogen was highly sensitive to ceftriaxone, cefotaxime, ciprofloxacin and lincomycin, moderately sensitive to enrofloxacin, neomycin, gentamycin, spectinomycin, florfenicol, amikacin and polymyxin, and resistant to ampicillin, amoxicillin and doxycycline.[Conclusions] This study provided reference for the prevention and control of diarrheal diseases in foxes in Qinhuangdao region.

Effect of Echinacea Polysaccharide on Secretion of IkB-αmRNA by IEC-6 Injured by LPS

[ Objective] This study was conducted to investigate the mechanism of Echinacea polysaccharide （EPS） in treatment of various bacterial infection and reduction of inflammation, so as to provide a theoretical basis for clinic application of EPS. [ Method ] Nuclear protein extracted from six groups, the normal control group, the simple lipopolysaccharide （LPS） group and the EPS （ with concentrations of 50,100,200 and 500 μg/ml, respectively） ＋ LPS groups was subjected to SDS-PAGE electrophoresis, and pIkB-α protein contents in the extracts were analyzed by Coomassie brilliant blue （CBB） staining and Western-Blot method. [ Result] The simple LPS group showed the highest pIkB-α protein level, and in the EPS concentration range of 0 -200 μg/ml, the expression level of pIkB-α pro- tein was improved with the increase of EPS concentration. [ Conclusion The expression level of pIkB-α protein was improved under the simulation of IEC-6 by LPS, while EPS could effectively inhibit the expression of pIkB-α protein. The expression level of pIkB-α was the lowest in the LPS ＋500 μg/ml EPS group.

Effect of Echinacea Polysaccharide on Secretion of IL-1αmRNA by IEC-6 Injured by LPS

[ Objective ] This study was conducted to investigate Echinacea polysaccharide （EPS） on expression of tumor necrosis factor （TNF） under injury of intestinal epithelial cells （IEC-6） by lipopolysaccharide （LPS）, so as to discuss the action mechanism of EPS to injured cells. [Method] Total DNA was extracted with TRIzon reagent, TNF-α mRNA was amplified, and the amplification products were subjected to agarose gel electrophoresis and imaging. [Result] 50 μg/ml EPS could partially inhibited the production of IL-α mRNA by IEC-6 under the stimulation of LPS, while the inhibition of 2（10 and 500 μg/ml EPS on the level of IL-1α mRNA gradually increased with the concentration increasing; and IEC-6 cells pretreated with 50,100,200 and 500 μg/ml EPS for 24 h and then stimulated by 10 μml IPS for 1 and 4 h were analyzed by RT-PCR method, and it was found that the expression of IL-α mRNA induced by LPS could be effectively inhibited by EPS, and the inhibition rate at 4 h was higher than that at 1 h. [ Conclusion] EPS could play its role of protecting intestinal mucosa by inhibiting the secretion of IL-1α mRNA by cells under the stimulation of LPS, and such inhibition effects of EPS had concentration dependency and time dependency.

Effects of Two Drugs on Small Intestinal Epithelial Lymphocytes of Experimental Piglets with Spleen Deficiency

[ Objective] This study aimed to investigate the effects of Guchang Cuzhang powder and Smecta on small intestinal epithelial lymphocytes of piglets with spleen deficiency and diarrhea induced by Reserpine. [ Method] Eighteen piglets with reserpine-induced spleen deficiency and diarrhea were selected and randomly divided into three groups, six per group, including Guchang Cuzhang powder group, Smeeta group and spleen deficiency control group. Piglets in two drug adnfinistration groups were treated for 7 d using Guchang Cuzhang powder and Smecta, respectively. On the 2nd d and 8th d after drug withdrawal, three piglets in each group were euthanized by jugular vein bleeding to death. Intestine segments in different groups were collected for paraffin embedding, section preparation and HE staining, to conduct histological observation and count the number of small intestinal epithelial lymphocytes. [ Result ] Compared with the spleen deficiency control group, the number of lymphocytes in small intestinal epithelium of piglets in two drug administration groups increased significantly; in addition, the number of lymphocytes in small intestinal epithelium of piglets in Guchang Cuzhang powder group was significantly higher than that in Smecta group. [ Conclusion ] This study provided theoretical basis for the clinical applieation of Guchang Cuzhang powder and Smecta.

Isolation,Identification and Drug Tolerance Analysis of Pathogenic Staphylococcus aureus from Broilers

White feather broilers in some broiler farm in Chengde area developed arthritis and died acutely. In order to identify the pathogen inducing the disease and death of the white feather broilers, samples such as livers and joint pus were collected from dead broilers under sterile condition, and one pathogenic strain was isolated. The isolate was identified to be Staphylococcus aureus through isolated culture, morphologic observation, inspection of biochemical property and animal test. The drug sensitivity test showed that the isolate was sensitive to ceftazidime, enrofloxacin, ceftriaxone, lincomycin and amikacin, but resistant to other drugs to different degrees.

PCR Detection of Pilus-associated Genes and Serotype Identification of Pathogenic Escherichia coli Isolated from Chickens in the Jidong Area

[ Objective] This study aimed to explore the presence of type I pill （fimC gene） and P pill （papC gene） and identify the serotype of pathogenic E. coli isolated from chickens in the Jidong Area. [ Method] Type I pill （fimC gene） and P pill （papC gene） were detected by PCR. The serotype was identified by con- ventional agglutination test. [ Result ] The results showed that 100% of chicken-derived E. coil strains expressed type I pill （fimC gene） ; 39.1% （9/23） of chick- en-derived E. coli strains expressed P pill （papC gene）. In addition, 23 isolates of chicken-derived E. coil were assigned to 14 O serotypes, including O78, O93, O 45, O101, O38, O88, O24, O1, O163, O53, O15, O87, O34 and O29, among which O78 was the dominant serotype that accounted for 42.8% （6/14） of the total strain number. [ Conclusion] Chicken-derived E. coli strains in the Jidong Area belonged to 14 serotypes, and 078 was the dominant serotype; 83.3% of 078 serotvDe E. coli strains expressed both tvDe I Dill and P Dill.

PCR Detection of Streptococcus agalactiae in Dairy Cows Suffering from Mastitis

[ Objective ] This study aimed to identify Streptococcus agalactiae and lay the foundation for the prevention and control of mastiffs in dairy cows. [ Method] Ten strains were isolated from milk samples produced by diseased dairy cows suffering from mastitis for morphologic observation, culture characteristic investigation, biochemical identification and Lancefield grouping. The isolated strains were identified at the molecular level by nested-PCR. [ Result] Among the ten isolates, six strains were 13-hemolytic and Gram-positive on blood agar, belonging to Lancefield group B, which were identified as Streptococcus agalactiae by biochemical identification and nested-PCR. After overnight incubation, the coincidence rate between results of nested-PCR detection and biochemical identification reached 100%. [ Conclusion ] Bacterial incubation, rapid DNA extraction and specific PCR can provide basis for early epidemiological survey of Streptococcus agalactiae infection in cattle.

Screening of Chinese Herbal Medicines against Avian Infectious Laryngotracheitis Virus and Escherichia coli

[ Objective] This study aimed to screen Chinese herbal medicines against avian infectious laryngotracheitis virus and Escherichia coli. [ Method ] Conventional Chinese medicine plate dilution method, plate punching method and test tube method were applied to screen Chinese herbal medicines against avian infectious laryngotracheitis virus based on chicken embryo inoculation experiment. [ Result ] Forsythia suspensa, Radix lsatidis, Isatis iadigotica, Lonicera japonica, Codonopsis pilosula, Astragalus membranaceus, Rhizoma Atractylodis Macrocephalae, C, tyeyrrhiza uralensis and Pericarpium granati had relatively strong anti-ILTV effect; among the Chinese herbal medicines against avian E. coli, Sanguisorba offwinalis, Fructus Mume, Rheum palmatum, Anemarrhena asphodeloides, Radix Scutellariae and Fagopyrum cymosum had relatively strong effect against avian E. coli Os, while other Chinese herbal medicines had relatively weak or no inhibitory effect on avian E. coli 0s and 05. [ Conclusion] This study laid the foundation for further development of Chinese herbal medicine compound preparations to treat avian infectious laryngotracheitis, avian colibacillosis and other viral diseases and bacterial diseases.

Histopathological Observation of Goose Escherichia coli Disease

[ Objective] This study aimed to provide reliable basis for in-depth understanding of histopathological changes in geese suffering from Escherichia coli disease and accurate diagnosis of goose E. coli disease. [ Method] By using paraffin embedding, section slicing and HE staining, histopathological changes in the heart, liver, spleen, lung, kidney and small intestine tissues of three diseased geese were observed. [ Result] The liver generated protein fiber membranes, showing liver cell degeneration, increasing number of red blood cells in sinusoids and liver congestion; the kidney had relatively serious lesions, including renal tubular epithelial cell degeneration, necrosis and shedding from the basement membrane and hyaline degeneration of glomerulars. The lung showed epithelial cell degeneration and necrosis and was filled with a large number of red blood cells and shedded epithelial cells, showing typical red hepatization; a large number of red blood ceils were aggregated in pulmonary blood vessels, resulting in lung congestion. Epithelial ceils of various digestive tubes all showed varying degrees of minor shed- ding and local infiltration of inflammatory ceils, thereby leading to death of geese due to substance metabolism, electrolyte and acid-base balance disorders and metabolic acidosis. [ Conclusion] Based on epidemiology survey, clinical symptom observation, pathological necropsy and laboratory diagnosis, the diseased geese were confirmed to be suffering from E. coli disease.

Histopathological Observation of Classical Swine Fever in Newborn Piglets

[ Objective] This study aimed to investigate pathological changes in various organs of piglets infected with classical swine fever and provide reliable basis for accurate diagnosis of classical swine fever. [ Method] By using paraffin embedding, section slicing and HE staining, histopathological changes in the heart, liver, spleen, lung, kidney and small intestine tissues of five diseased piglets were observed. C Result] Classical swine fever virus could lead to multiple visceral and mueosal hemorrhages, inflammatory cell infiltration, necrosis and other pathological changes. [ Conclusion ] Classical swine fever virus can further cause progressive degeneration and necrosis of different cells, resulting in immune injury.

Diagnosis and Control of Rabbit Hemorrhagic Disease(RHD)

In this study, chronic-type rabbit hemorrhagic disease occurred in rabbit warrens of Shandong, Liaoning, Beijing and Hebei, which was mainly charac-terized by deaths of young and adult rabbits, longer durationand nerve symptoms, was surveyed by epidemiological investigation, bacterial isolation and incubation, artificial infection test and histopathologieal method to analyze the causes of chronic-type rabbit hemorrhagic disease and put forward the corresponding control measures.

Histopathological Observation of Cynoglossus semilaevis Günther with Abdominal Dropsy in Industrial Aquaculture

[ Objective] This study aimed to investigate and analyze the histopathological changes in various tissues and organs of Cynoglossus semilaevis Gunther with abdominal dropsy. [ Method] By HE staining, pathological tissues of main organs of C. semilaevis Giinther with abdominal dropsy were observed. [ Result] According to the results of histopathological observation, C. semilaevis Gilnther with abdominal dropsy exhibited a large amount of ascites in the abdominal cavity; small intestinal mucosal epithelial cells were denatured and necrotic, and shed into the enteric cavity, with submucosal vascular congestion; the liver and pancreas tissues were denatured and necrotic, and the morphology of most liver cells disappeared. However, there was no remarkable pathological change in the heart, spleen and other organs. [ Conclusion] C. semilaevis Gtinther with abdominal dropsy exhibited serious pathological and histochemical lesions in the small intestine, liver and pancreas, causing metabolic disorders.

Phylogenetic Analysis of Virulence Factor Genes in Salmonella from Chicken

Salmonella is a common genus of seriously harmful food-borne zoonotic bacteria. Humans and animals may be infected with Salmonella through ingestion of SalmoneUa-contaminated eggs and poultry meat. Therefore, in order to reduce the incidence of Salmonella infections, it is crucial to explore the pathogenic mech- anism of Salmonella. invA and invE are major virulence factor genes that encode invasion proteins of Salmonella. In order to explore the pathogenic mechanism of Salmonella, phylogenetic analysis of major virulence factor genes in 33 Salmonella strains isolated from chicken was analyzed. According to the results, ivnA gene was successfully amplified from 33 Salmonella strains; ivnE gene was successfully amplified from 32 Salmonella strains, ivnA nucleotide sequences shared 72.9% - 97.6% homology among 12 sequenced Salmonella strains and shared 78.9% - 97.2% homology with those in GenBank ; ivnE nucleotide sequences shared over 95.3% homology among 23 sequenced Salmonella strains and shared 89.6% -98.6% homology with those in GenBank, which exhibited no genetic relationship to other organisms. This study provided the basis for rapid molecular detection, epidemiological research and molecular pathogenesis analysis of Salmonella.

Antibiotic Sensitivity Test and Detection of Sulfonamide Resistance Gene Sul2 in Escherichia coli Isolates from Swine

[ Objective] This study aimed to analyze antibiotic sensitivity and detect sulfonamide resistance gene Sul2 in 17 Escherichia coli isolates from swine. [ Method] The antibiotic sensitivity of 17 E. coil isolates from swine was analyzed with Kirby-Bauer disk diffusion method. Sulfonamide resistance gene Sul2 was detected by PCR amplification with the extracted genomic DNA as a template. [ Result] The 17 swine-derived E. coli isolates from different regions were resistant to various antibiotics and exhibited different multi-antibiotic resistance phenotypes, including nine isolates resistant to sulfamethoxazole, seven isolates resistant to oxacillin, ten isolates resistant to cefazolin and eight isolates resistant to erythromycin. Sulfonamide resistance gene Sul2 was successfully amplified from genomic DNA of E. coli isolates. The PCR results were basically consistent with antibiotic resistance phenotypes of these strains. [ Conclusion] Sul2 gene was widespread in swine-derived E. coli, which was closely associated with sulfonamide resistance phenotvpes of E. coli.

Histopathological Observation of Parvovirus Infection in Foxes

In this study, histopathological changes in the heart, liver, spleen, lung, kidney, intestine, brain and other organs of foxes died of parvovims infection were observed. According to the results, multiple organs of infected foxes were congested and hemorrhaged with tissue damage, inflammatory cell infiltration and a series of pathological changes, mainly exhibiting hepatic cell cord rupture, liver cell granular degeneration and fatty degeneration, small intestinal mucous mem- brane shedding, intestinal villi necrosis and shedding, severe hemorrhage of lamina pmpria with inflammatory cell infiltration, and severe small intestinal bleeding. This study laid a solid foundation for clinical diagnosis, prevention and treatment of parvovirus infection in foxes.

A Histological Study on Subacute Toxicity of "Baikening" in Hy-Line Brown Roosters

[ Objective] A histological study was conducted to investigate the toxicity of ＂Baikening＂ and the toxic effect of ＂Baikening＂ on roosters after longer- term administration at different dose levels. [ Method] Thirty 21-day-old Hy-Line Brown roosters were administered with 0.5 and 1.0 ml of ＂Balkening＂ aqueous extract through drinking water once a day for continuous 14 d. Roosters in control group and experimental groups after drug administration for 14 d and drug with- dmwal for 7 d were euthatfized; livers, kidneys, thymuses, spleens and bursas of Fabricius were collected and weighed for comparative analysis. Various tissues were prepared into paraffin-embedded slices and stained by H. E. , to observe histological changes of various organs under an optical microscope. [ Result ] After drug administration for 14 d, all the roosters in experimental groups survived; there was no visible pathological change in various organs of Hy-Line Brown roosters in each group; organ weights of Fly-Line Brown roosters in various groups showed no significant difference; observation results of tissue slices indicated that there was no pathological change in fine structures, nuclei and cytoplasm of various organs of Hy-Line Brown roosters in different groups ; various blood vessels in different organs also presented no change in blood circulation or other pathological changes. [ Conclusion] ＂Baikening＂ aqueous extract （oral administration） has no toxic and side effect on roosters in the subacute toxicity experiment.

Study on Antibacterial Effect of Single Chinese Herbs on Staphylococcus aureus

[Objectives] This study was conducted to determine in-vitro antibacterial effect of 58 Chinese herbs on Staphylococcus aureus,and screen single Chinese herbs with better in-vitro antibacterial effect for formulation of prescription. [Methods]Effective components in Chinese herbs were extracted with water,and inhibition zone diameters and minimal inhibitory concentrations of the 58 Chinese herbs against S. aureus were determined by agar plate punching method and micro two-fold method,respectively. [Results] Twenty two kinds of Chinese herbs including Terminalia chebula Retz.,Anemarrhena asphodeloides Bunge.,Prunella vulgaris L,Rheum palmatum L. and Mosla chinensis Maxim. had better antibacterial effect,among which T. chebula Retz.,A. asphodeloides Bunge.,P. vulgaris L,R. palmatum L. and C. sappan Linn showed the best antibacterial effect,with average inhibition zone over 20 mm and MIC lower than 15. 6 mg/ml.[Conclusions]Traditional Chinese herbs have certain antibacterial effect,and this study will provide important theoretical reference for clinical medication and development of prescription.