Yersinia enterocolitica의 시험관내 병원성 성상, plasmid 보유 및 외막 단백질(OMP) 생산간의 관계

박석기,최철순,전윤성,Park, Seog-gee,Choi, Chul-soon,Jeon, Yun-seong 대한수의학회 1992 大韓獸醫學會誌 Vol.32 No.2

Two hundred and eighty nine strains of Yersinia enterocolitica isolated from healthy pigs were tested for the presence of 40~50 Megadalton virulence-associated plasmids and plasmidmediated in vitro virulence-associated properties, i.e., congo red uptake, calcium dependency, autoagglutination, CRMOX reaction, crystal violet binding and pyrazinamidase reaction. The correlationships between in vitro virulence-associated properties and the presence of 220 Kdalton outer membrane protein(OMP) were examined in strains with or without virulence-associated plasmids. The correlationships between the presence of plasmids on the production of the OMP and the expression of in vitro virulence-associated properties were studied with $CRMOX^+$ strains and acridine orangecured $CRMOX^-$ mutants. The results were as follows : 1. Of the in vitro virulence-associated tests with 289 strains of Y enterocolitica, 275 strains (95.2%) were positive for pyrazinamidase test, and followed by in order of crystal violet binding test, 226 (79.2% ) ; CRMOX test, 190 (65.7%) ; autoagglutination test, 1.85(64.0%) : calcium dependency test, 86 (29.8%) and congo red uptake test, 47(16.3%). 2. The correlationship between autoagglutination and CRMOX test(r=0.90) was highly significant (p<0.01). 3. In 190 strains(65.7%) bearing the virulence-associated plasmids(MW 40~50 Mdalton), the correlation between the presence of plasmids and their in vitro virulence-associated properties were highest with CRMOX test(r=0.93) and followed by in orders of AAG test(0.81), CV test(0.46), PYZ test(0.37) and CD test(0.18), but no correlationship between the presence of plasmids and CR test(-0.11). 4. The $CRMOX^+$ strains produced the 220 Kdalton OMP when they were cultured at $37^{\circ}C$, but not at $26^{\circ}C$. The presence of 220 Kdalton OMP was correlated significantly with in vitro virulence properties and the presence of virulence-associated plasmid, respectively. 5. In the isogenic $CRMOX^-$ mutant strains, of which plasmid were cured by treatment with acridine orange not only in vitro virulence-associated properties(CR 100%, CD 100%, AAG 82.6%, CV 58.3%) disappeared but also 220 Kdalton OMP(100%) was not produced. These results indicate that the positive CRMOX reaction is plasmid-mediated and the CRMOX test is potential as an in vitro virulence tests with Y enterocolitica.

닭병원성 대장균과 야생조류유래 대장균 분리주에서 항생제 감수성 검사와 병원성 관련 유전자의 분포

송은아,오재영,안병기,서이경,윤재영,강민수,임춘태,권준헌,권용국 한국가금학회 2010 한국가금학회 정기총회 및 학술발표회 Vol.27 No.-

We compared the occurrence of antimicrobial resistance and virulenceassociated genes between 98 avian pathogenic Escherichia coli (APEC) and 790 E. coli strains isolated from normal wild birds. Of 15 antibiotics tested, 7 antibiotics such as nalidixic acid, tetracycline, ampicillin, sulfisoxazole, streptomycin, cephalothin, and enrofloxacin showed more than 30% resistance rate in APEC strains, whereas the resistance to E. coli (wild birds) strains was very low (Figure2). The 98 APEC strains and 120 of 790 E. coli strains (from wild birds) were detected the frequency of virulence-associated genes by multiplex PCR. The detection rates of virulence-associated genes tested in APEC strains were significantly higher than those of wild birds. The APEC strains comprised more than 40% against all 8 virulenceassociated genes. Although detection rates of virulence genes was low in E. coli strains of wild birds, they harbored almost every virulence-associated genes except for the cva A/B gene (Figure3). The distribution of virulence genes detected possesses twentyfive combination patterns in APEC strains, whereas E. coli strains of wild birds were divided into 14 gene combination patterns. According to antimicrobial disc tests and detection of virulence-associated genes, the APEC strains possesses multiple antibiotic resistance and virulence-associated genes which integrated into ColV plasmid with E. coli virulence. Even E. coli strains of wild birds also harbored various antimicrobial resistance and virulence markers.

Characterization of Sclerospora graminicola Isolates from Pearl Millet for Virulence and Genetic Diversity

Pushpavathi B.,Thakur R. P.,Rao K. Chandrashekara,Rao V. P. The Korean Society of Plant Pathology 2006 Plant Pathology Journal Vol.22 No.1

Virulence and genetic diversity were studied using 21 isolates of Sclerospora graminicola, the pearl millet downy mildew pathogen collected from major pearl millet growing areas of India. Variability for virulence was determined by inoculating a set of 10 differential hosts with the S. graminicola isolates in a greenhouse. The isolates varied for latent period (6.4 to 11 days), disease incidence (0 to $98\%$), virulence index (0 to 18.7) and oospore-production potential (1 to 4). Among the 21 isolates, Sg 139 (Rajasthan) was the most virulent and Sg 110 (Tamil Nadu) the least virulent. Based on virulence index (disease incidence$\time$slatent $period^{-1}$), the 21 isolates were classified into eight virulence groups. Genetic diversity among isolates was studied using AFLP markers. Based on similarity index of banding pattern, the 21 isolates were clustered into eight genotypic groups. The AFLP groupings, however, did not match with that of the virulence groupings, and these two were found independent. The isolate Sg 139 that remained distinct in both pathogenic and genetic groupings indicated its highly virulent nature. Implications of these results in downy mildew resistance breeding are discussed.

Prevalence of pathogenic <i>Arcobacter</i> species in South Korea: Comparison of two protocols for isolating the bacteria from foods and examination of nine putative virulence genes

Kim, Nam Hee,Park, Sun Min,Kim, Hye Won,Cho, Tae Jin,Kim, Soon Han,Choi, Changsun,Rhee, Min Suk Elsevier 2019 FOOD MICROBIOLOGY Vol.78 No.-

<P><B>Abstract</B></P> <P>Contamination of foodstuffs by potentially enteropathogenic <I>Arcobacter</I> spp. is becoming a concern worldwide. However, few studies have examined virulence-associated genes in isolates of <I>Arcobacter</I> spp. from food. Here, we investigated the prevalence of three pathogenic <I>Arcobacter</I> species, <I>A. butzleri</I>, <I>A. cryaerophilus</I>, and <I>A. skirrowii</I>, in chicken, pork, and leafy green vegetables (n = 323) in South Korea. Samples were examined using two different protocols selected from a literature review: Acrobacter selective broth (ASB) II + Arcobacter selective medium (ASM) II (protocol A), and ASB II + modified charcoal cefoperazone deoxycholate agar supplemented with CAT (protocol B). Overall, <I>Arcobacter</I> spp. were detected in 45.8% of food samples, and the recovery rate of protocol B (37.8%) was significantly higher than that of protocol A (30.7%) (<I>p</I> < 0.05). Refrigerated chicken gizzard samples showed the highest detection rate (100%), followed by refrigerated chicken wing (79.5%), intestine (77.3%), neck skin (63.3%), pork (55.6%), frozen chicken legs (5.0%), and leafy green vegetables (4.4%) (<I>p</I> < 0.05). All isolates from chicken and leafy green vegetables were identified as <I>A. butzleri</I>, whereas <I>A. cryaerophilus</I> and <I>A. skirrowii</I> were mainly detected in pork. Most samples (95.8%) harbored more than one of nine putative virulence factors (<I>cadF</I>, <I>ciaB</I>, <I>cj1349</I>, <I>hecA</I>, <I>hecB</I>, <I>mviN</I>, <I>pldA</I>, <I>irgA</I>, and <I>tlyA</I>), and 91.3% harbored more than two. Isolates harboring all nine putative virulence genes were obtained from 1.9% of samples: five pork and one chicken. This study provides comprehensive and <I>de facto</I> evidence regarding prevalence of an emerging pathogen, <I>Arcobacter</I> spp., in various foods, along with their virulence potential. The results justify further research with respect to their role in food safety.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This study provides comprehensive and <I>de facto</I> prevalence of <I>Arcobacter</I> spp. </LI> <LI> <I>Arcobacter</I> spp. were detected from 45.8% of food samples in South Korea. </LI> <LI> Frequently in refrigerated chicken > pork > frozen chicken > leafy green vegetables. </LI> <LI> Most isolates (95.8%) harbored more than one of the nine putative virulence factors. </LI> <LI> 91.3% contained more than two virulence factors, and 1.9% harbored all nine. </LI> </UL> </P>

Phage transcription activator RinA regulates Staphylococcus aureus virulence by governing sarA expression

Jiang Ming,Li Yilin,Sun Baolin,Xu Shiwen,Pan Ting,Li Yujie 한국유전학회 2023 Genes & Genomics Vol.45 No.2

Background Staphylococcus aureus is a major human pathogen, that can lead to various community- and hospital-acquired infections. RinA is a transcription activator of S. aureus phage φ 11 involved in phage packaging and virulence gene transfer. However, little is known about the molecular mechanism of RinA in the regulation of virulence. Objective We aimed to explore a novel contribution of RinA in the regulation of virulence and provide a new drug target in the treatment of S. aureus infections. Methods The specific functions of RinA in S. aureus were analyzed by the methods of growth curve, real-time quantitative PCR (RT-qPCR), subcellular localization, electrophoretic mobility shift assay (EMSA), infection model of Galleria mellonella larvae and the mouse subcutaneous abscess model. Results In this study, we demonstrated that RinA is a protein evenly distributed in the cytoplasm of S. aureus, and its deletion could cause the growth defects. RT-qPCR and EMSA determined that rinA could negatively regulate the expression of sarA by directly binding to its promoter, and vice versa. The Galleria mellonella larvae infection and mouse subcutaneous abscess models revealed that the rinA mutant strain exhibited obvious virulence defects. When sarA is knocked out, the virulence of S.aureus had no significantly changes whether rinA is knocked out or not. Conclusion Our fndings demonstrated that phage transcription activator RinA regulates S. aureus virulence by governing sarA expression.

Characterization of Sclerospora graminicola Isolates from Pearl Millet forVirulence and Genetic Diversity

B. Pushpavathi,R. P. Thakur,K. Chandrashekara Rao,V. P. Rao 한국식물병리학회 2006 Plant Pathology Journal Vol.22 No.1

Virulence and genetic diversity were studied using 21 isolates of Sclerospora graminicola, the pearl millet downy mildew pathogen collected from major pearl millet growing areas of India. Variability for virulence was determined by inoculating a set of 10 differential hosts with the S. graminicola isolates in a greenhouse. The isolates varied for latent period (6.4 to 11 days), disease incidence (0 to 98%), virulence index (0 to 18.7) and oospore-production potential (1 to 4). Among the 21 isolates, Sg 139 (Rajasthan) was the most virulent and Sg 110 (Tamil Nadu) the least virulent. Based on virulence index (disease incidence × latent period−1), the 21 isolates were classified into eight virulence groups. Genetic diversity among isolates was studied using AFLP markers. Based on similarity index of banding pattern, the 21 isolates were clustered into eight genotypic groups. The AFLP groupings, however, did not match with that of the virulence groupings, and these two were found independent. The isolate Sg 139 that remained distinct in both pathogenic and genetic groupings indicated its highly virulent nature. Implications of these results in downy mildew resistance breeding are discussed.

Profiling of Virulence-associated Factors in Shigella Species Isolated from Acute Pediatric Diarrheal Samples in Tehran, Iran

Sajad Yaghoubi,Reza Ranjbar,Mohammad Mehdi Soltan Dallal,Somayeh Yasliani Fard,Mohammad Hasan Shirazi,Mahmood Mahmoudi 질병관리본부 2017 Osong Public Health and Research Persptectives Vol.8 No.3

Objectives: The genus Shigella comprises the most infectious and diarrheagenic bacteria causing severe diseases, mostly in children under five years of age. This study aimed to detect nine virulence genes (ipaBCD, VirA, sen, set1A, set1B, ial, ipaH, stx, and sat) in Shigella species (spp.) using multiplex polymerase chain reaction (MPCR) and to determine the relation of Shigella spp. from pediatric diarrheal samples with hospitalization and bloody diarrhea in Tehran, Iran. Methods: Shigella spp. were isolated and identified using standard microbiological and serological methods. The virulence genes were detected using MPCR. Results: Seventy-five Shigella spp. (40 S. sonnei, 33 S. flexneri, 1 S. dysenteriae, and 1 S. boydii) were isolated in this study. The prevalence of ial, sen, sat, set1A, and set1B was 74.7%, 45.4%, 28%, 24%, and 24%, respectively. All S. flexneri isolates, while no S. sonnei, S. dysenteriae, or S. boydii isolates, contained sat, set1A, and set1B. All isolates were positive for ipaH, ipaBCD, and virA, while one (1.4%) of the isolates contained stx. The highest prevalence of virulence determinants was found in S. flexneri serotype IIa. Nineteen (57.6%) of 33 S. flexneri isolates were positive for ipaBCD, ipaH, virA, ial, and sat. The sen determinants were found to be statistically significantly associated with hospitalization and bloody diarrhea (p = 0.001). Conclusion: This study revealed a high prevalence of enterotoxin genes in S. flexneri, especially in serotype 2a, and has presented relations between a few clinical features of shigellosis and numerous virulence determinants of clinical isolates of Shigella spp.

Loss of glutamate dehydrogenase in Ralstonia solanacearum alters dehydrogenase activity, extracellular polysaccharide production and bacterial virulence

Wu, J.,Kong, H.G.,Jung, E.J.,Choi, S.Y.,Lee, H.J.,Tao, W.,Chung, E.,Lee, S.W. Academic Press 2015 Physiological and molecular plant pathology Vol.90 No.-

Metabolism in Ralstonia solanacearum, which causes lethal wilt on Solanaceous plants, is poorly understood. In this study, we selected a Tn5-inserted mutant of R. solanacearum SL341 showing various phenotypic changes and altered virulence. When the gdhA gene encoding NAD(P)<SUP>+</SUP>-dependent glutamate dehydrogenase was disrupted, the gdhA mutant of SL341 (SL341P2) was defective in red colony development on tetrazolium chloride-amended medium and showed less extracellular polysaccharide (EPS) production. The growth rate of the gdhA mutant on rich medium did not differ from that of the wild-type strain; however, its growth on minimal medium with glutamate as the sole carbon source was completely inhibited. SL341P2 was also defective in the oxidation of several carbon sources compared to the wild type. All the observed defects of SL341P2 gdhA mutant were fully or partially restored by providing the gdhA gene in trans. The gdhA mutant showed reduced virulence after soil-soaking inoculation of tomato plants, both on susceptible tomato cultivar Moneymaker and on the well-known bacterial-wilt-resistant cultivar Hawaii 7996. The delayed disease development by the gdhA mutant was due to slower multiplication of the mutant bacteria than wild type in tomato plants. Taken together, these results indicate that GdhA is required for diverse metabolic functions in R. solanacearum, including normal production of the virulence factor EPS, as well as normal bacterial growth in planta and full virulence on tomato plants.

Analysis of whole genome sequencing and virulence factors of Vibrio vulnificus 1908-10 isolated from sea water at Gadeok island coast

Hee-kyung Oh,김남은,김도형,Hye-Young Shin,이은우,엄성환,김영목 한국수산과학회 2023 Fisheries and Aquatic Sciences Vol.26 No.9

Vibrio vulnificus is an aquatic bacterium causing septicemia and wound infection in humans. To understand this pathogen at the genomic level, it was performed whole genome sequencing of a cefoxitin-resistant strain, V. vulnificus 1908-10 possessing virulence-related genes (vvhA, viuB, and vcgC) isolated from Gadeok island coastal seawater in South Korea. The genome of V. vulnificus 1908-10 consisted of two circular contigs and no plasmid. The total genome size was estimated to be 5,018,425 bp with a guanine-cytosine (GC) content of 46.9%. We found 119 tRNA and 34 rRNA genes respectively in the genome, along with 4,352 predicted protein sequences. Virulence factor (VF) analysis further revealed that V. vulnificus 1908-10 possess various virulence genes in classes of adherence, antiphagocytosis, chemotaxis and motility, iron uptake, quorum sensing, secretion system, and toxin. In the comparison of the presence/absence of virulence genes, V. vulnificus 1908-10 had fur, hlyU, luxS, ompU, pilA, pilF, rtxA, rtxC, and vvhA. Of the 30 V. vulnificus comparative strains, 80% of the C-genotype strains have all of these genes, whereas 40% of the E-genotype strains have all of them. In particular, pilA were identified in 80% of the C-type strains and 40% of the E-type strains, showing more difference than other genes. Therefore, V. vulnificus 1908-10 had similar VF characteristics to those of type C strains. Multifunctional-autoprocessing repeats-in-toxin (MARTX) toxin of V. vulnificus 1908-10 contained 8 A-type repeats (GXXGXXXXXG), 25 B.1-type repeats (TXVGXGXX), 18 B2-type repeats (GGXGXDXXX), and 7 C-type repeats (GGXGXDXXX). The National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) showed that the RtxA protein of V. vulnificus 1908-10 had the effector domain in the order of cross-liking domain (ACD)-C58_PaToxP-like domain- α/β hydrolase-C58_PaToxP-like domain.

이중특이성 인산화 효소의 결손이 Candida albicans 병원성에 미치는 효과

박윤희 ( Yun Hee Park ),박희문 ( Hee Moon Park ) 한국균학회 2011 韓國菌學會誌 Vol.39 No.1

The opportunistic human pathogen Candida albicans has the ability to convert from yeast-form to pseudohyphal or true hyphal form. The morphological transition is considered as an important virulence factor, because the decrease or lack in dimorphism causes the reduction of virulence. Our previous study revealed that the disruption of dual specificity kinase gene caused the reduction of dimorphism in C. albicans. Therefore we tested the effect of dual specificity kinase in virulence using mouse model. The mean survival time for kinase-defective strains was about 15 days in comparison with those of wild-type, 3.9 days. Moreover the fungal burden on kidneys for kinase-defective strains was decreased by ten-fold than that for wild-type. These results suggest possible involvement of dual specificity kinase in a novel signal transduction pathway for morphological transition and virulence of C. albicans.