African swine fever virus (ASFV) is a large, intracytoplasmicallyreplicating DNA arbovirus and the sole member of the family Asfarviridae . It is the etiologic agent of a highly lethal hemorrhagic disease of domestic swine and therefore extensively studied to elucidate the structures, genes, and mechanisms affecting viral replication in the host, virus-host interactions, and viral virulence. Increasingly apparent is the complexity with which ASFV replicates and interacts with the host cell during infection. ASFV encodes novel genes
This study was conducted to examine the in vitro activity of antimicrobials against Campylobacter spp. isolates from chicken and human sources and the genetic interrelation among them. During 2004-2008, a total of 173 Campylobacter spp. isolated from chicken meats (60 domestic and 62 imported chicken meats) and humans (n = 51) were tested for susceptibility to nine antimicrobials. Of 173 isolates, 140 (80.9%) showed multidrug resistance (MDR) against three to eight antimicrobials. The most frequent pattern type was MDR to four antimicrobials: ciprofloxacin, nalidixic acid, ampicillin, and tetracycline. Over 52.6% (91/173) of the isolates tested were resistant to these four antibiotics simultaneously. Especially, two and five isolates originated from Korea and Brazil showed resistance against all antibiotics tested, except for florfenicol. Further, 95% (57/60) of the isolates originated from domestic chicken showed resistance to ciprofloxacin, the antimicrobial agent of choice for treatment of human campylobacteriosis. Genotypic characterization of all Campylobacter isolates performed by pulsed-field gel electrophoresis yielded 74 types among the 173 isolates. Isolates sharing the same or similar genetic clusters were detected in different countries at different times. The pulsed-field gel electrophoresis patterns of chicken-related isolates were closely related to those of isolates from humans with gastroenteritidis. The results of this study suggest that MDR Campylobacter spp. are widespread and that Campylobacter with similar genotypes are circulating both in humans and in chicken meat in Korea.
Campylobacteriosis in humans is primarily caused by handling or consuming contaminated poultry or their products. The aims of this study were to estimate the prevalence of Campylobacter spp. in domestic and imported poultry meat in Korea and to further characterize the obtained isolates. From 2004 to 2008, a total of 475 domestic and 867 imported raw poultry meat samples were examined for the presence of Campylobacter spp. Among 475 domestic poultry meat samples, Campylobacter jejuni and Campylobacter coli were isolated from 219 (46.1%) and 156 (32.8%), respectively. Relative prevalence of C. jejuni and C. coli was higher in meat from Brazil (39/78, 50.0% and 7/78, 8.9%) and France (32/96, 33.3% and 8/96, 8.3%), whereas lower in meat from Denmark (72/516, 14.0% and 12/516, 2.3%) and Thailand (5/39, 12.8% and 3/39, 7.6%). The resistance to ampicillin and tetracycline was highly prevalent in Campylobacter spp. from most countries investigated, whereas lower in meat from Denmark. On the other hand, the prevalence of erythromycin and gentamicin resistance was less than 10% in most countries. The resistance rate to nalidixic acid, ciprofloxacin, and enrofloxacin ranged from 11.9% to 87.5%. The use of fla-polymerase chain reaction–restriction fragment length polymorphism for epidemiological analysis found that some pattern types were considerably more frequent and distinct in meat from each country. In conclusion, we report the presence of high contamination in domestic and imported poultry meat in Korea and the antimicrobial and genetic diversity of Campylobacter spp. between each country.
ABSTRACT. In this study, we performed experiments to evaluate the extend of the process of apoptotic cell death by foot-and-mouth disease virus (FMDV). Apoptosis can also occur in some virus-infected cells, and ability of viruses to either inhibit or promote apoptosis may influence the pathologic outcome of infection. In this study, to determine if apoptosis plays a role in the outcome of FMDV infection in swine, we evaluated apoptosis in diseased tissues collected from pigs inoculated with two different stains of FMDV (O1 Campos and O Taiwan). And host cell DNA fragmentation in diseased tissue from animals which were infected with either virus was evaluated by occurrence of a laddering pattern characteristic of apoptosis. Infection of cultured keratinocytes from swine tongue failed to demonstrate apoptosis in the first few hours of infection, suggesting that cell-to-cell correlation between viral antigen and apoptotic changes, e.g. cytokine secretions by immune system cells, could be critical to initiating apoptosis. Consistent with this finding, we were able to detect the pro-inflammatory cytokine TNF-α in diseased tissues. A clear difference in the pathogenicity of the two different FMDV isolates to pigs was not demonstrated in our study. KEY WORDS: apoptosis, FMD, pathogenesis.J. Vet. Med. Sci. 67(11): 1081-1088, 2005 Foot-and-mouth disease (FMD) is one of the most contagious disease of livestock. Essentially all cloven-hoofed species are susceptible to this disease [20]. Following FMDV infection, vesicles develop in the snout, nares, lips, tongue, hard and soft palate, coronary band, soft tissues of the feet, soft tissues around the dew claws, and teats of the infected animals [5]. In young animals, infection of the heart muscle may result in severe myocardial necrosis and death. During the acute phase of the infection (2-7 days post-exposure), virus is found in large quantities in oral and respiratory secretions [4,5,25]. Apoptosis, which is also known as programmed cell death, is a process of cell suicide which is initiated under a variety of circumstances [2,8,18,28,31]. On the other hand, an alternative mechanism for such an apoptosis-leading effect of the FMDV infection on bystander cells could then be explained by the local release of apoptogenic cytokines (i.e., tumor necrosis factor) [21]. Apoptosis is essential for the natural replacement of tissues (homeostasis) and has been documented in a variety of cells, including dermal keratinocytes. These cells undergo a continuous process of proliferation, differentiation and apoptosis in order to maintain the protective properties of skin [6,10,29].In this manuscript, we present data on apoptosis in FMDV-infected swine and primary cultures of swine lingual epithelial keratinocytes, and discuss the possible roles of apoptosis in FMDV replication and virulence. For these studies, we utilized two isolates of FMDV, one was a South American bovine isolate (O1 Campos, from Campos, Brazil, 1958) and the other was a porcinophilic Asian isolate (O Taiwan, from th...
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