Genome typing of adenovirus strains isolated from conjunctivitis in Japan, Australia, and the Philippines

DNA restriction endonuclease analysis for genome typing of adenovirus (Ad) DNA was carried out on a total of 65 Ad isolates including serotypes Ad4, Ad7, Ad8, Ad11, Ad19, and Ad37 from patients with epidemic keratoconjunctivitis and acute conjunctivitis obtained in Japan from 1982 to 1986, Australia from 1973 to 1986, and the Philippines in 1984. All 4 isolates of Ad7 in Australia were Ad7b. Four of 6 Ad11 isolates obtained in Japan were typed as Ad11 prototype (Ad11p), and the remaining were identified to be new genome types, designated tentatively as Ad11c and Ad11d. An isolate of Ad11 obtained in Australia was typed as Ad11c. Nine Ad8 isolates in Australia and in the Philippines were typed as Ad8p, but 11 Ad8 isolates in Japan were Ad8b. Thirteen Ad19 isolates were identified as Ad19a. All 3 isolates of Ad37 in Japan and three isolates in Australia before 1982 were typed as Ad37p, however, 5 isolates in Australia after 1983 were identified as a new genome type, designated as Ad37d. In Japan, 10 isolates of Ad4 were identified as Ad4a.     

基于线粒体细胞色素氧化酶I（COI）序列的猪和兔四个疥螨分离株的系统发育关系分析

为了探讨兔疥螨分离株和猪疥螨分离株的分类地位, 采用PCR技术首次扩增了分离自中国猪和兔的4个疥螨分离株的线粒体细胞色素氧化酶I（COI）基因, 并与GenBank中注册的14个国外疥螨分离株的同源基因进行了比较。序列分析结果显示: 扩增的4个疥螨株COI基因长度均为1 427 bp, 序列间无插入、缺失, A+T含量（73%）明显高于G+C含量（27%）, 碱基组成存在明显偏移。猪和兔的4个疥螨分离株间的COI基因同源性较高（99.1%～100.0%）, 它们与澳大利亚人疥螨株、国外动物疥螨株的同源性范围为98.4%～99.6%。在构建的NJ树中, 分离自中国猪和兔的4个疥螨分离株同澳大利亚人疥螨分离株、国外动物疥螨分离株亲缘关系较近。根据疥螨COI基因同源性分析和系统树构建结果, 我们认为分离自中国猪和兔的4个疥螨分离株与澳大利亚人疥螨分离株以及国外的动物疥螨分离株均应属于同一个种。     

Pathogenicity of Race-1 and Race-2 Tomato Wilt Isolates of Verticillium dahliae from Different Geographical Origins

Fourteen race-1 and race-2 isolates of Verticillium dahliae from North America, Europe and Australia were screened against the near isogenic pair of tomato cultivars Roma and Roma VF. The foliar symptoms, extent of stunting and vascular colonization were assessed. Race-1 isolates were significantly more pathogenic on Roma which lacks the Ve resistance gene. Race-2 isolates from N. America were more pathogenic than those from Australia. All isolates tested colonized both cultivars to some extent although the level of colonization by race-1 isolates was significantly higher in Roma than in Roma VF. All race-1, and the majority of race-2, isolates caused stunting of Roma. No isolates stunted Roma VF.     

MECHANISMS CONTROLLING NUCLEAR MIGRATION ALONG THE TRICHOGYNE IN THE RED ALGA, BOSTRYCHIA MORITZIANA (RHODOMELACEAE, RHODOPHYTA)

Caloglossa species are widely distributed in mangroves and salt marshes around the world and their life history patterns are being investigated in laboratory culture. In Australia all isolates of C. monosticha , C. postiae and C. ogasawaraensis have Polysiphonia -type (P-type) sexual life histories. Among the 70 C. leprieurii isolates from Australia and New Zealand P-type sexual reproduction also is dominant. However, ten isolates of C. leprieurii from the Spencer Gulf and the Gulf of St. Vincent in South Australia give rise to successive tetrasporphyte generations without gametophytes. Moreover, one isolate from Queensland is asexual. Only one South Australia isolate, obtained from Lake Alexandrina at the mouth of the Murray River, is sexual. South Australia and Pacific Mexico are two regions in which asexual reproduction is dominant. In another mangrove dwelling red alga Bostrychia moritiziana (Rhodomelaceae) non-sexual reproduction also is frequent in Australia, New Caledonia and Bali (Indonesia). This asexual reproductive pattern of tetrasporophytic recycling appears to have arisen independently among individual populations of various red algal species in different regions. Investigations are underway on the molecular phylogeny of the Caloglossa leprieurii isolates.     

The origin of a new focus of infection with Echinococcus granulosus in Tasmania.

Hydatid cysts were discovered in cattle on King Island, north of Tasmania, where Echinococcus granulosus was thought to have been eradicated. Using enzyme electrophoresis, isolates from King Island were compared genetically with isolates from Tasmania and the mainland of Australia. The genetic distinctness of the King Island isolates make it unlikely that they originated from a recent introduction from either Tasmania or mainland Australia. Alternative possibilities, that the infection resulted from a recent introduction from another source or from previously undetected persistence of E. granulosus on King Island, could not be distinguished from available data.     

Expanding distribution of human serotype G6 rotaviruses in Australia

Serotype G6 rotaviruses are common pathogens of cattle but are rarely found in humans. In Australia, human G6 isolates have previously been detected in two major southern population centres. A new isolate, ASG6.02, was detected in central Australia (Alice Springs) in 1997. Comparison of the deduced amino acid sequence of the major neutralizing antigen, VP7, indicated that ASG6.02 was related to human G6 viruses isolated from children in Italy and Australia. Phylogenetic analysis supported the close relationship between ASG6.02 and other Australian isolates and indicated that G6 VP7 sequences generally clustered according to the species of origin (human, bovine or porcine). The VP4 type of ASG6.02 was determined as P-type [14], in common with other isolates from Australia and Italy. The detection of ASG6.02 indicates that the distribution of this serotype is increasing in this country and may have implications for successful vaccine development.     

Variation in pathogenicity of isolates of Cercospora spp. attacking Heliotropium spp.

The pathogenicity of a set of 13 Cercospora samples collected in France, Turkey and Australia from four Heliotropium species has been evaluated with a detached leaf technique. All of five Euro-Asian Heliotropium species tested were susceptible to all Cercospora species isolates. However, variation in the degree of partial resistance to different isolates was observed and showed some similarity for isolates from the same region of origin. Further studies are required to clarify the taxonomy of Cercospora blight strains, but the consequences of the noted differences in pathogenicity are discussed in relation to the biological control ofH. europaeum L. in Australia.     

The origin of a new focus of infection with Echinococcus granulosus in tasmania

Hydatid cysts were discovered in cattle on King Island, north of Tasmania, where Echinococcus granulosus was thought to have been eradicated. Using enzyme electrophoresis, isolates from King Island were compared genetically with isolates from Tasmania and the mainland of Australia. The genetic distinctness of the King Island isolates make it unlikely that they originated from a recent introduction from either Tasmania or mainland Australia. Alternative possibilities, that the infection resulted from a recent introduction from another source or from previously undetected persistence of E. granulosus on King Island, could not be distinguished from available data.     

Mycotoxin formation by different geographic isolates of Fusarium crookwellense

Eighteen Fusarium crookwellense isolates from the continents of Australia, Europe, and North America were compared for their ability to produce mycotoxins on corn at 25 °C after 2 weeks. Extracts from corn fermented with each Fusarium isolate were analyzed by thin-layer chromatography (TLC) and gas chromatography/mass spectroscopy (GS/MS) for mycotoxins. Toxins detected were zearalenone (13 isolates), fusarin C (11 isolates), nivalenol (4 isolates), and diacetoxyscirpenol (2 isolates). Zearalenone and fusarin C were produced by isolates from each continent, while nivalenol was detected in the Fusarium isolates originating from Australia and one isolate from the United States.The mention of firm names or trade products does not imply that they are endorsed or recommended by the U.S. Department of Agriculture over other firms or similar products not mentioned     

Characterization of aquatic bacteria and cloning of genes specifying partial degradation of 2,4-dichlorophenoxyacetic acid.

Water samples from rivers, streams, ponds, and activated sewage were tested for the presence of bacteria which utilize 2,4-dichlorophenoxyacetic acid (2,4-D) as a sole source of carbon. Seventy percent of the attempted enrichments yielded pure cultures of 2,4-D-metabolizing bacteria. All but 1 of the 30 isolates were gram-negative rods, all but 2 were motile, and all were nonfermentative and oxidase and catalase positive. Nine isolates had DNA guanine-plus-cytosine values of 61.1 to 65 mol%. One isolate had a 67 mol% guanine-plus-cytosine value. The results suggest that these 2,4-D-metabolizing bacteria belong to the genus Alcaligenes. Fourteen of 23 isolates contained one or more detectable plasmids of about 20, 60, or 100 megadaltons. HindIII restriction fragment patterns showed these plasmids to be different from each other with one exception. Very similar restriction fragment patterns were revealed with a plasmid isolated from an Alcaligenes eutrophus strain obtained from Australia (pJMP397) and in an Alcaligenes sp. isolated in Oregon (pEML159). These two plasmids were about 56 megadaltons, had the same guanine-plus-cytosine value, were transmissable, and coded for 2,4-D metabolism and resistance to HgCl2. Hybridization of these two plasmids was demonstrated by using nick-translated 32P-labeled pJMP397. The vector pBR325 was used to clone HindIII fragments from pEML159. One cloned fragment of 14.8 megaldaltons expressed in Escherichia coli the ability to release 14CO2 from 2,4-D labeled in the acetate portion.     

Characterization of aquatic bacteria and cloning of genes specifying partial degradation of 2,4-dichlorophenoxyacetic acid

Water samples from rivers, streams, ponds, and activated sewage were tested for the presence of bacteria which utilize 2,4-dichlorophenoxyacetic acid (2,4-D) as a sole source of carbon. Seventy percent of the attempted enrichments yielded pure cultures of 2,4-D-metabolizing bacteria. All but 1 of the 30 isolates were gram-negative rods, all but 2 were motile, and all were nonfermentative and oxidase and catalase positive. Nine isolates had DNA guanine-plus-cytosine values of 61.1 to 65 mol%. One isolate had a 67 mol% guanine-plus-cytosine value. The results suggest that these 2,4-D-metabolizing bacteria belong to the genus Alcaligenes. Fourteen of 23 isolates contained one or more detectable plasmids of about 20, 60, or 100 megadaltons. HindIII restriction fragment patterns showed these plasmids to be different from each other with one exception. Very similar restriction fragment patterns were revealed with a plasmid isolated from an Alcaligenes eutrophus strain obtained from Australia (pJMP397) and in an Alcaligenes sp. isolated in Oregon (pEML159). These two plasmids were about 56 megadaltons, had the same guanine-plus-cytosine value, were transmissable, and coded for 2,4-D metabolism and resistance to HgCl2. Hybridization of these two plasmids was demonstrated by using nick-translated 32P-labeled pJMP397. The vector pBR325 was used to clone HindIII fragments from pEML159. One cloned fragment of 14.8 megaldaltons expressed in Escherichia coli the ability to release 14CO2 from 2,4-D labeled in the acetate portion.     

BIOGEOGRAPHY OF ASEXUAL AND SEXUAL REPRODUCTION IN CALOGLOSSA (DELESSERIACEAE,RHODOPHYTA) FROM AUSTRALIA AND NEW ZEALAND

Caloglossa species are widely distributed in mangroves and salt marshes around the world and their life history patterns are being investigated in laboratory culture. In Australia all isolates of C. monosticha, C. postiae and C. ogasawaraensis have Polysiphonia‐type (P‐type) sexual life histories. Among the 70 C. leprieurii isolates from Australia and New Zealand P‐type sexual reproduction also is dominant. However, ten isolates of C. leprieurii from the Spencer Gulf and the Gulf of St. Vincent in South Australia give rise to successive tetrasporphyte generations without gametophytes. Moreover, one isolate from Queensland is asexual. Only one South Australia isolate, obtained from Lake Alexandrina at the mouth of the Murray River, is sexual. South Australia and Pacific Mexico are two regions in which asexual reproduction is dominant. In another mangrove dwelling red alga Bostrychia moritiziana (Rhodomelaceae) non‐sexual reproduction also is frequent in Australia, New Caledonia and Bali (Indonesia). This asexual reproductive pattern of tetrasporophytic recycling appears to have arisen independently among individual populations of various red algal species in different regions. Investigations are underway on the molecular phylogeny of the Caloglossa leprieurii isolates.     

Characterization of Colletotrichum acutatum causing anthracnose of anemone (Anemone coronaria L.)

Anthracnose, or leaf-curl disease of anemone, caused by Colletotrichum sp., has been reported to occur in Australia, western Europe, and Japan. Symptoms include tissue necrosis, corm rot, leaf crinkles, and characteristic spiral twisting of floral peduncles. Three epidemics of the disease have been recorded in Israel: in 1978, in 1990 to 1993, and in 1996 to 1998. We characterized 92 Colletotrichum isolates associated with anthracnose of anemone (Anemone coronaria L.) for vegetative compatibility (72 isolates) and for molecular genotype (92 isolates) and virulence (4 isolates). Eighty-six of the isolates represented the three epidemics in Israel, one isolate was from Australia, and five isolates originated from western Europe. We divided these isolates into three vegetative-compatibility groups (VCGs). One VCG (ANE-A) included all 10 isolates from the first and second epidemics, and 13 of 62 examined isolates from the third epidemic in Israel, along with the isolate from Australia and 4 of 5 isolates from Europe. Another VCG (ANE-F) included most of the examined isolates (49 of the 62) from the third epidemic, as well as Colletotrichum acutatum from strawberry, in Israel. Based on PCR amplification with species-specific primers, all of the anemone isolates were identified as C. acutatum. Anemone and strawberry isolates of the two VCGs were genotypically similar and indistinguishable when compared by arbitrarily primed PCR of genomic DNA. Only isolate NL-12 from The Netherlands, confirmed as C. acutatum but not compatible with either VCG, had a distinct genotype; this isolate represents a third VCG of C. acutatum. Isolates from anemone and strawberry could infect both plant species in artificial inoculations. VCG ANE-F was recovered from natural infections of both anemone and strawberry, but VCG ANE-A was recovered only from anemone. This study of C. acutatum from anemone illustrates the potential of VCG analysis to reveal distinct subspecific groups within a pathogen population which appears to be genotypically homogeneous by molecular assays.     

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.     

Isolation of Aeromonas hydrophila from a metropolitan water supply: seasonal correlation with clinical isolates.

The occurrence of Aeromonas spp. in the metropolitan water supply of Perth, Western Australia, Australia, was monitored at several sampling points during a period of 1 year. Water within the distribution system conformed to international standards for drinking water but contained Aeromonas spp. in numbers comparable to those in raw surface water, although this water was free of Escherichia coli. Coliforms and E. coli were found in raw surface waters, and Aeromonas spp. were found in raw water from surface and underground sources. Chemical treatment, followed by chlorination at service reservoirs, resulted in water free of E. coli and a decrease in the number of Aeromonas spp. Aeromonas spp. were found in the greatest numbers in summer. Multiple regression analysis showed that growth of Aeromonas spp. in chlorinated water was related to water temperature, residual chlorine, and interaction between these variables. The incidence of Aeromonas-associated gastroenteritis, determined from isolates referred to us for enterotoxin testing, paralleled the pattern of isolation of Aeromonas spp. in water within the distribution systems. We suggest that the presence of Aeromonas spp. in drinking water needs public health appraisal and that further work should be undertaken to permit reevaluation of standards for the quality of drinking water.     

Geographically diverse Australian isolates of Melissococcus pluton exhibit minimal genotypic diversity by restriction endonuclease analysis

Melissococcus pluton, the causative agent of European foulbrood is an economically significant disease of honey bees (Apis mellifera) across most regions of the world and is prevalent throughout most states of Australia. 49 Isolates of M. pluton recovered from diseased colonies or honey samples in New South Wales, Queensland, South Australia, Tasmania and Victoria were compared using SDS-PAGE, Western immunoblotting and restriction endonuclease analyses. DNA profiles of all 49 geographically diverse isolates showed remarkably similar AluI profiles although four isolates (one each from Queensland, South Australia, New South Wales and Victoria) displayed minor profile variations compared to AluI patterns of all other isolates. DNA from a subset of the 49 Australian and three isolates from the United Kingdom were digested separately with the restriction endonucleases CfoI, RsaI and DraI. Restriction endonuclease fragment patterns generated using these enzymes were also similar although minor variations were noted. SDS-PAGE of whole cell proteins from 13 of the 49 isolates from different states of Australia, including the four isolates which displayed minor profile variations (AluI) produced indistinguishable patterns. Major immunoreactive proteins of approximate molecular masses of 21, 24, 28, 30, 36, 40, 44, 56, 60, 71, 79 and 95 kDa were observed in immunoblots of whole cell lysates of 22 of the 49 isolates and reacted with rabbit hyperimmune antibodies raised against M. pluton whole cells. Neither SDS-PAGE or immunoblotting was capable of distinguishing differences between geographically diverse isolates of M. pluton. Collectively these data confirm that Australian isolates of M. pluton are genetically homogeneous and that this species may be clonal. Plasmid DNA was not detected in whole cell DNA profiles of any isolate resolved using agarose gel electrophoresis.     

Genetic diversity in the blackberry rust pathogen, Phragmidium violaceum, in Europe and Australasia as revealed by analysis of SAMPL

Indigenous to Europe, the blackberry rust fungus Phragmidium violaceum was introduced to Australia and subsequently appeared in New Zealand, with the most recent authorised introductions to Australia specifically for the biological control of European blackberry. Markers for ‘selective amplification of microsatellite polymorphic loci’ (SAMPL) were developed for studying the population genetics of P. violaceum. Modification of one of the two SAMPL primers with a HaeIII adapter (H) revealed significantly greater levels of genetic variation than primers used to generate AFLPs, the latter revealing little or no variation among 25 Australasian and 19 European isolates of P. violaceum. SAMPL was used to describe genetic variation among these 44 isolates of P. violaceum from 51 loci generated using primer pairs (GACA)₄ + H–G and R1 + H–G. The European isolates were more diverse than Australasian isolates, with 37 and 22 % polymorphic loci, respectively. Cluster analysis revealed geographic clades, with Australasian isolates forming one cluster separated from two clusters comprising the European isolates. However, low bootstrap support at these clades suggested that Australian isolates had not differentiated significantly from European isolates since the first record of P. violaceum in Australia in 1984. In general, the results support two hypotheses. First, that the population of P. violaceum in Australia was founded from a subset of individuals originating from Europe. Second, that P. violaceum in New Zealand originated from the Australian population of P. violaceum, probably by wind dispersal of urediniospores across the Tasman Sea. The application of SAMPL markers to the current biological control programme for European blackberry is discussed.     

Diversity of tetracycline resistance genes in bacteria from aquaculture sources in Australia

AIMS: To determine the genetic determinants responsible for tetracycline resistance in oxytetracycline resistant bacteria from aquaculture sources in Australia. METHODS AND RESULTS: Twenty of 104 (19%) isolates tested were resistant to oxytetracycline (MIC > or = 16 microg ml(-1)). Using polymerase chain reaction (PCR) amplification, one or more tet genes were detected in 15/20 (75%) isolates tested, but none were found in 5/20 (25%). tetM (50%) was the most common determinant, followed by tetE (45%), tetA (35%) and tetD (15%). Five of 12 oxytetracycline resistant isolates studied were able to transfer their R-plasmid to Escherichia coli recipients of chicken, pig and human origin. tetA, tetD and tetM were found to be transferred while tetE was not transferred. Southern hybridization and PCR were used to confirm transfer of determinants. CONCLUSIONS: Bacterial isolates from aquaculture sources in Australia harbour a variety of tetracycline resistance genes, which can be transferred to other bacteria of different origin. SIGNIFICANCE AND IMPACT OF THE STUDY: Bacteria from aquaculture sources in Australia contribute to the resistance gene pool reservoir. The in vitro transfer of tetracycline R-plasmid from aquatic bacteria to E. coli isolates from various sources is an indication of the potential public health risk associated with these resistance determinants.     

Multiple gene sequences delimit Botryosphaeria australis sp. nov. from B. lutea

Botryosphaeria lutea (anamorph Fusicoccum luteum) most easily is distinguished from other Botryosphaeria spp. by a yellow pigment that is formed in young cultures. This fungus has been reported from a number of cultivated hosts in New Zealand and Portugal. During a survey of Botryosphaeria fungi that occur on native Acacia species in Australia, a yellow pigment was observed in some cultures. These isolates were morphologically similar to B. lutea, but the pigment differed slightly from the one formed by authentic B. lutea isolates. Preliminary data also revealed small differences in ITS rDNA sequence data. The aim of this study was to determine whether these small differences were indicative of separate species or merely variations within B. lutea. Anamorph, teleomorph and culture morphology were compared between B. lutea and Acacia isolates from Australia. Sequence data of two other genome regions, namely the β-tubulin and EF1-α gene and intron regions, were combined with ITS rDNA sequence data to determine the phylogenetic relationship between these isolates. Isolates of B. lutea and those from Australian Acacia species were not significantly different in spore morphology. The yellow pigment, however, was much more distinct in cultures of B. lutea than in cultures from Acacia. There were only a few base pair variations in each of the analyzed gene regions, but these variations were fixed in the two groups in all regions. By combining these data it was clear that B. lutea and the isolates from Acacia were distinct species, albeit very closely related. We, therefore, propose the new epithet B. australis for the fungus from Australia. Botryosphaeria australis also was isolated in this study from exotic Sequoiadendron trees in Australia. Re-analyses of GenBank data in this study showed that B. australis also occurs on other native Australian hosts, namely a Banksia sp. and a Eucalyptus sp., as well as a native Protea sp. in South Africa and on Pistachio in Italy. These records from GenBank have been identified previously as B. lutea. The common occurrence of B. australis on a variety of native hosts across Australia suggests that this fungus is native to this area.     

Invaded range of the blackberry pathogen Phragmidium violaceum in the Pacific Northwest of the USA and the search for its provenance

Field surveys in 2006 confirmed that the exotic rust fungus Phragmidium violaceum was widespread on Rubus armeniacus and Rubus laciniatus in the Pacific Northwest of the USA. The origin and dispersal pattern of this obligate biotrophic pathogen in the USA were investigated by comparing the genetic diversity and structure of 27 isolates each from the USA and Europe, and 20 isolates from Australia where an invasion occurred in 1984. Analysis of 11 microsatellite loci revealed 74 unique genotypes, with the European population having a significantly higher level of allelic diversity and number of private alleles compared to populations from the USA and Australia. Principal coordinate analysis (PCA), analysis of molecular variance and pairwise comparisons of Φ confirmed a strong level of differentiation among continental populations, with little divergence between isolates from the USA and Europe, but a high level of differentiation between these isolates and those from Australia. These results were broadly supported by the Bayesian cluster analysis, which indicated that at K = 3 the clustering of the isolates corresponds to their geographic origin. Bayesian clustering, PCA as well as insignificant migration estimates from Europe to the USA suggest that the USA population is not a direct descendant from the European P. violaceum population. There was a weak association between genetic and geographic distance among the USA isolates, suggesting invasion was initially localized prior to dispersal or that the population may have been present for some time prior to first detection in 2005.