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Molecular detection and genetic diversity of porcine circovirus type 3 in commercial pig farms in Xinjiang province, China
2019
Mengfan, Qiao | Xifeng, Wang | Guowu, Zhang | Qingling, Meng | Jun, Qiao | Lixia, Wang | Kuojun, Cai | Jinsheng, Zhang | Zaichao, Zhang | Weiwei, Yu | Yelong, Peng | Xuepeng, Cai
Porcine circovirus type 3 (PCV3) is a newly discovered porcine circovirus. The molecular characteristics and genetic evolution of PCV3 in Xinjiang province, China still being unclear, the aim of the study was their elucidation. A total of 393 clinical samples were collected from pigs on commercial farms in nine different regions of Xinjiang and phylogenetic analysis based on full-length Cap genes was performed. The prevalence at farm level was 100%, while in all the tested samples it was 22.39%. Nine PCV3 strains were detected in Xinjiang province and they shared 98.9–99.3% nucleotide and 97.5–100.0% Cap gene amino acid sequence identities with other epidemic strains from China and abroad. Compared with other epidemic strains of PCV3, there were 26 base mutation sites in the Cap gene in the nine Xinjiang strains, resulting in the mutation of amino acids at positions 20, 24, 75, 77, 108, 111 and 206. Phylogenetic analysis showed that these strains can be divided into two different genetic groups, to the first of which five strains affiliated and divided between subgroups 1.1 and 1.2, and to the second of which the other four strains affiliated and similarly divided between subgroups 2.1 and 2.2. PCV3 circulates widely among commercial pig farms in Xinjiang province, China, and displays obvious genetic diversity. The results provide epidemiological information useful for the prevention and control of PCV3 infection in the pig industry.
Mostrar más [+] Menos [-]African swine fever virus – persistence in different environmental conditions and the possibility of its indirect transmission
2019
Mazur-Panasiuk, Natalia | Żmudzki, Jacek | Woźniakowski, Grzegorz
Since 2007, African swine fever (ASF) has posed a serious threat to the European swine industry. In Poland, the numbers of reported outbreaks in pigs and affected areas grow every year. In 2018, the disease was noted in Western Europe, in Belgium specifically, where several hundred infected wild boars have been detected so far. In 2018, the virus unexpectedly emerged in pig holdings in eastern China, northern Mongolia, Vietnam, and Cambodia, causing worldwide concern about its further spread. Since there is still no vaccine available, the only approach to control the disease is biosecurity. Identification of potential sources of the virus is extremely important in light of its phenomenal survivability. The review summarises the current knowledge about ASFV survivability and resistance to environmental conditions, and discusses the role of indirect contact in spreading the disease.
Mostrar más [+] Menos [-]Marine tetrodotoxin as a risk for human health
2019
Madejska, Anna | Michalski, Mirosław | Osek, Jacek
Tetrodotoxin (TTX) is a toxin mainly occurring naturally in contaminated puffer fish, which are a culinary delicacy in Japan. It is also detected in various marine organisms like globefish, starfish, sunfish, stars, frogs, crabs, snails, Australian blue-ringed octopuses, and bivalve molluscs. TTX is produced by marine bacteria that are consumed mainly by fish of the Tetraodontidae family and other aquatic animals. TTX poisoning through consuming marine snails has recently begun to occur over a wider geographical extent through Taiwan, China, and Europe. This neurotoxin causes food intoxication and poses an acute risk to public health. The aim of this review is to present the most recent information about TTX and its analogues with particular regard to toxicity, methods of analysis, and risk to humans of exposure.
Mostrar más [+] Menos [-]Virulence factors and antibiotic resistance of avian pathogenic Escherichia coli in eastern China
2019
Xu, Xiaojing | Sun, Qing | Zhao, Lixiang
Avian pathogenicEscherichia coli (APEC) causes serious colibacillosis and significant economic losses. Data on profiles of virulence factors and antibiotic resistances among APEC strains are crucial to the control of infection. In this study, strains were isolated from eastern China, and the prevalence of virulence factors and distribution of antibiotic resistance were determined. APEC strains were isolated and characterised by PCR for O serogroups, virulence factor genes, antibiotic resistance, and phylogenetic groups. O78 was the most prevalent serogroup and type A was the most frequent phylogenetic group. ThefimH,feoB, andiron genes were the most prevalent among the isolates. All isolates were multiresistant, and all strains were resistant to ampicillin and tetracycline, which are widely used in the poultry industry in China. This study provided important data on the presence of virulence genes and antibiotic resistance profiles of APEC from poultry farms in eastern China.
Mostrar más [+] Menos [-]Vesicular disease in pigs inoculated with a recent Canadian isolate of Senecavirus A
2019
The objective of this study was to investigate whether a virulent Canadian isolate of Senecavirus A (SVA) causes idiopathic vesicular disease (IVD) in pigs. Senecavirus A, which was first isolated in the United States in 2002 as Seneca Valley Virus, was linked to cases of porcine idiopathic vesicular disease in Canada in 2007 and in the United States in 2010. Since 2014, SVA outbreaks in Brazil, the US, Canada, China, Thailand, and Colombia point to an expanding global distribution and the need to study the pathogenicity of the virus. Unlike the prototype virus, recent US isolates of SVA have been shown to cause vesicular disease in pigs. We report vesicular disease in pigs following experimental inoculation with a 2016 Canadian isolate of SVA. All inoculated pigs developed vesicular lesions regardless of route of inoculation. Virus was detected in blood and oral fluids as well as on oral and fecal swabs. In addition, all pigs seroconverted to SVA by 6 days post-inoculation (DPI). This study confirms that recent Canadian isolates of SVA cause vesicular disease in pigs and highlights the importance of monitoring SVA for increased virulence.
Mostrar más [+] Menos [-]Epidemiology and molecular characterization of the antimicrobial resistance of Pseudomonas aeruginosa in Chinese mink infected by hemorrhagic pneumonia
2019
Bai, X. | Liu, S. | Zhao, J. | Cheng, Y. | Zhang, H. | Hu, B. | Zhang, L. | Shi, Q. | Zhang, Z. | Wu, T. | Luo, G. | Lian, S. | Xu, S. | Wang, J. | Zhang, W. | Yan, X.
Hemorrhagic pneumonia in mink is a fatal disease caused by Pseudomonas aeruginosa. Very little is known about P. aeruginosa in relation to genotype and the mechanisms underlying antimicrobial resistance in mink. A total of 110 P. aeruginosa samples were collected from mink from Chinese mink farms between 2007 and 2015. Samples underwent molecular genotyping using pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST), antimicrobial susceptibility and its mechanism were investigated at the molecular level. The PFGE identified 73 unique types and 15 clusters, while MLST identified 43 (7 new) sequence types (ST) and 12 sequence type clonal complexes (STCC). Sequence types and PFGE showed persistence of endemic clones in cities Wendeng (Shandong, China) and Dalian (Liaoning, China), even in different timelines. The MLST also revealed the gene correlation of the mink P. aeruginosa across different time and place. The ST1058 (n = 14), ST882 (n = 11), and ST2442 (n = 10) were the predominant types, among which ST1058 was the only one found both in Shandong province and Dalian (Liaoning, China). The MLST for P. aeruginosa infection in mink was highly associated with that in humans and other animals, implying possible transmission events. A small proportion of mink exhibited drug resistance to P. aeruginosa (9/69, 13%) with resistance predominantly to fluoroquinolone, aminoglycoside, and β-lactamase. Eight strains had mutations in the quinolone-resistance determining regions (QRDR). High proportions (65%; 72/110) of the fosA gene and 2 types of glpt deletion for fosmycin were detected. Furthermore, in the whole genome sequence of one multidrug resistant strain, we identified 27 genes that conferred resistance to 14 types of drugs.
Mostrar más [+] Menos [-]Genetic characterization of a hantavirus isolated from Heilongjiang province, China
2019
Wang, Y. | Cao, S. | Cheng, C. | Ju, W. | Hua, Y.
Hantavirus is the causative agent of hemorrhagic fever with renal syndrome (HFRS). Heilongjiang Province is experiencing an epidemic of HFRS, the main causative agent is a variant of hantavirus called Seoul virus (SEOV). In this study, the entire genome of one SEOV, the DN2 strain, was sequenced and analyzed. The alignment analysis of the sequences indicated that the DN2 strain shares the highest homology with the SEOV-LYO852 strain. The nucleotide identity is 97.6% for the S segment, 97.7% for the M segment, and 98.0% for the L segment. The corresponding amino acid sequence homologies are 99.1%, 98.9% and 99.8%. The phylogenetic analysis of the segments suggests that the DN2 strain has a high genetic relationship with SEOV strains and no genetic recombination occurs.
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