• The Plant Pathology Journal
• /
• 제33권1호
• /
• pp.43-52
• /
• 2017

A survey was conducted to determine the status of Lucerne transient streak virus (LTSV) in three high-yielding alfalfa regions in central Saudi Arabia (Riyadh, Qassim, and Hail) during 2014. Three hundred and eight symptomatic alfalfa, and seven Sonchus oleraceus samples were collected. DAS-ELISA indicated that 59 of these samples were positive to LTSV. Two isolates of LTSV from each region were selected for molecular studies. RT-PCR confirmed the presence of LTSV in the selected samples using a specific primer pair. Percentage identity and homology tree comparisons revealed that all Saudi isolates were more closely related to each other but also closely related to the Canadian isolate-JQ782213 (97.1-97.6%) and the New Zealand isolate-U31286 (95.8-97.1%). Comparing Saudi isolates of LTSV with ten other sobemoviruses based on the coat protein gene sequences confirmed the distant relationship between them. Eleven out of fourteen plant species used in host range study were positive to LTSV. This is the first time to document that Trifolium alexandrinum, Nicotiana occidentalis, Chenopodium glaucum, and Lathyrus sativus are new host plant species for LTSV and that N. occidentalis being a good propagative host for it.

• 대한의생명과학회지
• /
• 제21권2호
• /
• pp.84-91
• /
• 2015

To provide guidelines for the empirical treatment of urinary tract infections, we observed annual changes in the occurrence frequency and antimicrobial susceptibility of urinary isolates in a university hospital in the Chungbuk province, South Korea, over a period of 10 years (2004~2013). Escherichia coli (38.2%), Enterococcus faecalis (11.7%), Klebsiella pneumoniae (7.3%), Pseudomonas aeruginosa (4.3%), E. faecium (4.3%), and Staphylococcus aureus (4.1%) were commonly isolated urinary pathogens. The prevalence of E. coli, E. faecium and Streptococcus agalactiae were significantly higher in females (P < 0.001), whereas E. faecalis, P. aeruginosa and S. aureus were significantly more common in male patients (P < 0.001). E. coli mostly frequently showed resistance to ampicillin (67.94%), followed by trimethoprim/sulfamethoxazole (36.06%) and ciprofloxacin (26.84%). Over the studied time period, resistance rates of E. coli to ciprofloxacin significantly increased (20.44% to 33.55%). Moreover, extended-spectrum $\beta$-lactamase (ESBL) producing isolates also significantly increased in E. coli (4.2% to 18.3%) and K. pneumoniae (9.6% to 26.9%). In addition, the proportion of vancomycin-resistant Enterococcus facium (VRE) also increased (15.7% to 25.0%). In conclusion, over the last 10 years, the proportions of ciprofloxacin resistant E. coli and multidrug-resistant bacteria, such as ESBL and VRE have significantly increased. This trend must be strictly controlled and demonstrates the need for more updated guidelines for the treatment of urinary tract infections.

• The Plant Pathology Journal
• /
• 제27권3호
• /
• pp.232-341
• /
• 2011

Pink snow mold, caused by Microdochium nivale, is a major disease on cool season turfgrasses in golf courses in northern Unites States. The relative susceptibility of 17 commercial cultivars of three bentgrass species (creeping, colonial and velvet bentgrass) to Microdochium nivale and the aggressiveness of M. nivale eight isolates obtained from infected turfgrasses on golf courses in Wisconsin were evaluated under controlled conditions. For the field trial, susceptibility of 2 year-old 12 commercial bentgrass cultivars was evaluated after inoculating three M. nivale isolates in the fields. There were significant differences in disease severities among the three bentgrass species, particularly between tetraploids (creeping and colonial) and diploid (velvet) species, and among cultivars within each species, indicating that there are varying levels of susceptibility in species and cultivars to M. nivale. Host resistance by days of cold hardening was confirmed, by detecting the resistance by 30 days of cold hardening treatments. In field trial, susceptibility of 12 bentgrass cultivars was highly correlated to the results obtained from growth chamber experiments. The positive correlation of the susceptibility between growth chamber experiments and field trials demonstrates that the growth chamber method is a useful technique for saving time, space and labor to evaluate efficiently pink snow mold susceptibility of bentgrass cultivars. This study could be applied to evaluating susceptibility of bentgrass to pink snow mold and also predicting a prospective evaluation of bentgrass cultivars to pink snow mold in fields in a breeding program.

• 한국미생물·생명공학회지
• /
• 제46권3호
• /
• pp.210-224
• /
• 2018

Warqe (Ensete ventricosum) has been traditionally fermented in an earthen pit to yield a carbohydrate-rich food product named kocho, for generations. A fermentation enhancer (gammaa) was added to this fermenting mass to enhance the fermentation process. The objectives of this study were to assess the physicochemical properties and microbiota of the kocho fermentation enhancer culture to reduce losses. Cross-sectional study design was implemented to collect 131 gammaa samples on the first day of fermentation. The samples were further classified into four groups according to the duration of fermentation (14, 21, 30, and 60 days) practised in various households traditionally. The results showed that the fermentation time significantly affected the physicochemical properties and microbial load of gammaa (p < 0.01). As the fermentation progressed from day 1 to 60, the pH decreased and the titratable acidity increased. The total coliform, Enterobacteriaceae, aerobicmesophilic bacteria (AMB), yeast, and mould counts were significantly reduced at the end of fermentation. In contrast, the number of lactic acid bacteria (LAB) increased significantly until day 30 of fermentation, because of the ability of the LAB to grow at low pH. Lactobacillus species from LAB isolates and Enter obacteriaceae from AMB isolates were the most abundant microorganisms in gammaa fermentation. However, the Enterobacteriaceae and Lactobacilli species count showed decreasing and increasing trends, respectively, as the fermentation progressed. These isolates must be investigated further to identify the species and strain, so as to develop gammaa at the commercial scale.

• 농약과학회지
• /
• 제12권3호
• /
• pp.270-276
• /
• 2008

전국 고추재배 포장에서 2005년부터 2007년까지 3년간 분리한 151개의 고추 역병균을 가지고 연도별 metalaxyl에 대한 감수성 정도를 조사하였다. 그 결과 Phytophthora capsici에 대한 metalaxyl의 평균 $EC_{50}$ 값은 역병균을 채집한 3년 동안 2005, 2006, 2007년의 균주들이 1.454, 0.830, $0.323{\mu}g\;mL^{-1}$로 그 값이 감소하고 있었으며, 2007년에 채집한 균주에서는 저항성 병원균을 전혀 분리하지 못하였다. Metalaxyl에 저항성인 고추 역병균이 mandiproramid와 dimethomorph에 대해서 교차 저항성을 보이는 지를 조사한 결과, metalaxyl과 다른 두 약제 mandipropamid와 diinethomorph의 사이에는 전혀 상관관계가 없었다. 또한 metalaxyl에 대한 저항성은, 역병균의 균사 생장 속도와 고추에 대한 병원성과도 상관관계가 없었다.

• 대한수의학회지
• /
• 제43권1호
• /
• pp.103-112
• /
• 2003

A multiplex PCR assay, which allows simultaneous detection of vancomycin resistant genotypes and Enterococcus species-specific genes, was developed. Vancomycin resistant enterococci (VRE) from chickens and humans could be detected for vanA, vanB, vanC-1, vanC-2, $ddl_{E.faecium}$ and $ddl_{E.faecalis}$ by multiplex PCR. Eight isolates of VRE from humans (n=11) had $ddl_{E.faecium}$ and vanA, and 3 isolates of the VRE had $ddl_{E.faecium}$ and vanB. One isolate of VRE from chickens (n=6) had $ddl_{E.faecium}$ and vanA, and 5 isolates of the VRE had only vanA. E. faecium, E. faecalis, E. gallinarum and E. casseliflavus were also confirmed for the species-specific gene by multiplex PCR. This multiplex PCR could detect E. faecium, E. faecalis, E. gallinarum, E. casseliflavus, vanA, vanB, vanC-1 and vanC-2, simultaneously. The PCR assay established in the present study can be an alternative to time-consuming biochemical tests and antibiotic susceptibility tests of Enterococcus spp.

• 대한수의학회지
• /
• 제46권4호
• /
• pp.371-379
• /
• 2006

Newcastle disease virus (NDV) is a single-stranded negative sense RNA virus, which has been classified as a member of the Avulavirus genus of the Paramyxoviridae family. It is also one of the most important pathogens in the poultry industry. The glycoproteins, fusion (F) and hemagglutinin-neuraminidase (HN), determine the virulence of NDV, and the relevant molecular structures have already been determined. NDV isolates differ in terms of virulence, and at least 2 of 9 genotypes (I-IX) have been shown to co-circulate. Therefore, it is clearly important to differentiate between vaccine strains and field isolates. In vivo pathogenicity tests have been the standard protocol for some time, but molecular methods appear preferable in terms of the rapidity of diagnosis, as well as animal welfare concerns. In this study, we have designed primer sets from HN gene for phylogenetic analysis and restriction enzyme analysis, and from F gene for pathotype-specific RT-PCR. Via the combination of 2 methods, 106 Korean NDV isolates obtained from 1980 to 2005 were differentiated into vaccine strains, and virulent genotypes VI and VII. The genotype VI viruses were only rarely isolated after 1999, and genotype VII, after it was initially isolated from poultry in 1995, recurred in 2000, and then became the main NDV constituting a threat to the Korean poultry industry.

• The Plant Pathology Journal
• /
• 제36권1호
• /
• pp.87-97
• /
• 2020

The development of reverse transcription-polymerase chain reaction using degenerate primers against conserved regions of most potyviral genomes enabled sampling of the potyvirome. However, these assays usually involve sampling potential host plants, but identifying infected plants when they are asymptomatic is challenging, and many plants, especially wild ones, contain inhibitors to DNA amplification. We used an alternative approach which utilized aphid vectors and indicator plants to identify potyviruses capable of infecting common bean (Phaseolus vulgaris). Aphids were collected from a range of asymptomatic leguminous weeds and trees in Iran, and transferred to bean seedlings under controlled conditions. Bean plants were tested serologically for potyvirus infections four-weeks postinoculation. The serological assay and symptomatology together indicated the presence of one potyvirus, and symptomology alone implied the presence of an unidentified virus. The partial genome of the potyvirus, encompassing the complete coat protein gene, was amplified using generic potyvirus primers. Sequence analysis of the amplicon confirmed the presence of an isolate of Wisteria vein mosaic virus (WVMV), a virus species not previously identified from Western Asia. Phylogenetic analyses of available WVMV sequences categorized them into five groups: East Asian-1 to 3, North American and World. The Iranian isolate clustered with those in the World group. Multiple sequence alignment indicated the presence of some genogroup-specific amino acid substitutions among the isolates studied. Chinese isolates were sister groups of other isolates and showed higher nucleotide distances as compared with the others, suggesting a possible Eastern-Asian origin of WVMV, the main region where Wisteria might have originated.

• 대한수의학회지
• /
• 제39권2호
• /
• pp.343-352
• /
• 1999

Vancomycin resistant enterococci (VRE) have emerged as an important nosocomial pathogen. Since 1989 the Center for Disease Control, United States, has reported a rapid increase in the incidence of enterococcal bacteremia and endocarditis infection by VRE. It was suggested that the use of avoparcin was associated with the appearance of VRE in animal husbandry. To date, several detection methods have been used based on conventional methods of culture and gene detection. However, these methods have some limitations such as time-consuming, laborious and additional differential needs. Therefore, In this study a multiplex PCR method was established to detect and differentiate resistance types of enterococci which specifically amplify the four van genes encoding vancomycin resistance elements. Using the method, we investigated the incidence rates and types of VRE from farms using or not using avoparcin. A total of 1091 animal fecal samples were collected from 70 pig and 32 poultry farms. A total of 425 of enterococci were isolated from samples. Of the 425 isolates, 11 of the them showed a pattern of high-level vancomycin resistance (MIC : $64{\sim}256{\mu}g/ml$) which was associated with the presence of the vanA or vanB gene. Fifty-seven isolates showed a pattern of low-level vancomycin resistance (MIC : $3{\sim}8{\mu}g/ml$) associated with the vanC-1 or vanC-2 gene. Interestingly, all isolates with high-level vancomycin resistance were from farms that have never used avoparcin. Moreover, the high-level VRE isolation rate in Korea (2.58%) was much lower than that of other countries (50% in England, 7% in Belgium) where avoparcin have been used. In conclusion, the multiplex PCR method established in this study could be applied for detection of VRE.

• Journal of Microbiology and Biotechnology
• /
• 제20권12호
• /
• pp.1605-1613
• /
• 2010

Twenty-nine P. polymyxa strains isolated from rhizospheres of various crops were clustered into five genotypic groups on the basis of BOX-PCR analysis. The characteristics of several plant growth-promoting factors among the isolates revealed the distinct attributes in each allocated group. Under gnotobiotic conditions, inoculation of pepper roots with P. polymyxa isolates significantly increased the biomass in 17 of total 29 treated plants with untreated plants. Experiments on induced systemic resistance (ISR) against bacterial spot pathogen Xanthomonas axonopodis pv. vesicatoria in pepper by P. polymyxa strains were conducted and only one isolate (KNUC265) was selected. Further studies into ISR mediation by the KNUC265 strain against the soft-rot pathogen Erwinia carotovora subsp. carotovora in tobacco demonstrated that the tobacco seedlings exposed to either bacterial volatiles or diffusible metabolites exhibited a reduction in disease severity. In conclusion, ISR and plant growth promotion triggered by P. polymyxa isolates were systemically investigated on pepper for the first time. The P. polymyxa KNUC265 strain, which elicited both ISR and plant growth promotion, could be potentially used in improving the yield of pepper and possibly of other crops.