ABSTRACT. Clostridial diseases are zoonoses and are classified as soil-borne diseases. Clostridium chauvoei and Clostridium tetani cause blackleg disease and tetanus, respectively. Since bacteria and spores are re-distributed by floods and then, subsequently, contaminate soils, pastures and water; the case numbers associated with clostridial diseases usually increase after floods. Because Taiwan is often affected by flood damage during the typhoon season, possible threats from these diseases are present. Thus, this study's aim is to apply a combination of a commercial nucleic acid extraction kit and PCR to assess the prevalence of Clostridia spp. in soil and to compare the positivity rates for farms before and after floods. The minimum amounts of Clostridium tetanus and Clostridium chauvoei that could be extracted from soils and detected by PCR were 10 and 50 colony forming units (cfu), respectively. In total, 76 samples were collected from the central and southern regions of Taiwan, which are the areas that are most frequently damaged by typhoons. Noteworthy, the positive rates for Clostridium tetanus and Clostridium chauvoei in Pingtung county after the severe floods caused by a typhoon increased significantly from 13.73 and 7.84% to 53.85 and 50.00%, respectively. This study for the first time provides the evidence from surveillance data that there are changes in the environmental distribution of Clostridium spp. after floods. This study indicates that screening for soil-related zoonotic pathogens is a potential strategy that may help to control these diseases.

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Abstract. Infectious bronchitis virus (IBV; Avian coronavirus) causes acute respiratory and reproductive and urogenital diseases in chickens. Following sequence alignment of IBV strains, a combination of selective primer sets was designed to individually amplify the IBV wild-type and vaccine strains using a multiplex amplification refractory mutation system reverse transcription polymerase chain reaction (ARMS RT-PCR) approach. This system was shown to discriminate the IBV wildtype and vaccine strains. Moreover, an ARMS real-time RT-PCR (ARMS qRT-PCR) was combined with a high-resolution analysis (HRMA) to establish a melt curve analysis program. The specificity of the ARMS RT-PCR and the ARMS qRT-PCR was verified using unrelated avian viruses. Different melting temperatures and distinct normalized and shifted melting curve patterns for the IBV Mass, IBV H120, IBV TW-I, and IBV TW-II strains were detected. The new assays were used on samples of lung and trachea as well as virus from allantoic fluid and cell culture. In addition to being able to detect the presence of IBV vaccine and wild-type strains by ARMS RT-PCR, the IBV Mass, IBV H120, IBV TW-I, and IBV TW-II strains were distinguished using ARMS qRT-PCR by their melting temperatures and by HRMA. These approaches have acceptable sensitivities and specificities and therefore should be able to serve as options when carrying out differential diagnosis of IBV in Taiwan and China.

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Beak and feather disease virus (BFDV) is an avian circovirus, and it has a single-stranded DNA genome. It causes a fatal disease in parrots called psittacine beak and feather disease (PBFD). After screening of samples collected from Taiwan using PCR, complete genome sequences of isolates from 21 samples from various species of parrot were obtained. The nucleotide sequences of the replication-associated protein gene (rep) and the amino acid sequences of the replication-associated protein (Rep) were more conserved than the nucleotide sequences of the capsid protein gene (cp) and the amino acid sequences of the capsid protein (CP). In Bayesian phylogenetic analysis, the topology of the complete genome sequence was similar to that of the rep gene alone. Recombination events were identified in Taiwan isolates. Recombination hot spots were mainly located in the intergenic region between the 3' ends of the rep and cp genes and at the 5' end of the cp gene. The 5' end and the middle of the rep gene were found to be recombination cold spots. Despite the overall negative selection that was observed for the rep and cp genes, one and 18 positive selected sites were found for the rep and cp gene, respectively.