Heat-induced injury inListeria monocytogenes

Summary Heating ofListeria monocytogenes (Scott A strain) in potassium phosphate buffer (0.1 M, pH 7.2) at 52°C for 1 h led to injury, with the heat-injured cells failing to produce colonies on agar medium containing 5% NaCl. The detection of injury was based on the use of differential media: plating on tryptose phosphate broth+2% agar and 1% sodium pyruvate (TPBA+P) and on tryptose phosphate broth+2% agar and 5% NaCl (TPBA+S). Only non-injuredListeria formed colonies on TPBA+S whereas both heat-injured and non-injured cells formed colonies on TPBA+P. The bacterial count on TPBA+P minus that on TPBA+S represents the extent of heat injury. A large number of selective agars were tested and compared to TPBA+P for their ability to support repair and colony formation of heat-injuredL. monocytogenes. Media containing 0.025% phenylethanol, 0.0012–0.0025% acriflavin, 0.1–0.2% potassium tellurite, 0.001% polymyxin B sulfate, 5% NaCl or a combination of these ingredients were detrimental to the recovery of heat-injuredL. monocytogenes. Media currently in use forL. monocytogenes are not satisfactory for the recovery of injured cells.     

The Selection of an Isolate of the Hyphomycete Fungus,Metarhizium anisopliae,for Control of Termites in Australia

Ninety-three isolates ofMetarhizium anisopliae,mostly derived from a survey of termite material, were screened for activity againstNasutitermes exitiosusandCoptotermes frenchiorC. acinaciformisusing a grooming assay technique. Twenty-six of the most promising isolates were further evaluated by bioassay againstN. exitiosusandC. acinaciformis.All isolates were pathogenic withCoptotermesspp. being more susceptible thanN. exitiosus.A group of nine isolates, chosen for their level of pathogenicity for one or other genus of termites and to represent a genetically diverse group, was finally compared in a minicolony test using termite colonies in 1 liter jars. The isolate, code-named FI-610 (derived from nest-mound material ofC. lacteusin SE New South Wales), was one of the most effective isolates against termites from both of the two colonies tested. This isolate also grew relatively well on agar plates at 36°C. FI-610 was thus selected for field trials and was found to be effective in killing colonies ofC. acinaciformiswhen 10 g (=3 × 10¹¹conidia) or more of conidial powder was blown into the center of the large mound colonies.     

Effect of selective media on loss of congo red binding inShigella flexneri

Summary The effect of growth ofShigella flexneri on various selective media on retention of congo red (CR) binding ability was determined to evaluate the effectiveness of isolation techniques regarding maintenance of the virulence plasmid. WhenS. flexneri was surface-plated onto selective agars and the resulting colonies replica plated onto CR plates, no white colonies indicative of loss of virulence were found despite repeated trials. However, whenS. flexneri was grown in liquid media (agar was removed from agar-containing media by centrifugation), white colonies were found upon plating onto CR plates. Most common selective media for shigellae produced fewer than 5–10 white colonies/1000 red colonies. However, growth in broth prepared from violet red bile agar, desoxycholate citrate agar, and SS agar gave more than 100 white colonies/1000 red colonies. Loss of CR binding was demonstrated whenS. flexneri was grown in broth containing tergitol 7, sodium dodecyl sulfate, bile salts #3, crystal violet, eosin y or methylen blue. However, concentrations of selective agents that led to loss of CR binding were much higher than those used in selective media. Results indicate that under usual conditions of isolation ofS. flexneri from food and clinical specimens, CR binding appears to be a relatively stable character with most selective media; however, use of violet red bile agar, desoxycholate citrate agar, and SS agar may lead to substantial loss of congo red binding indicating that the isolates may not be virulent.     

Formation of nodular structures on the non-legumes Brassica napus,B. campestris,B. juncea and Arabidopsis thaliana with Bradyrhizobium and Rhizobium isolated from Parasponia spp. or legumes grown in tropical soils

Strains of Bradyrhizobium formed nodule-like structures on Arabidopsis and species of Brassica in pots with sandvermiculite and in glass tubes on a nitrogen-free mineral salts agar. Broad-host-range Rhizobium strains NGR234 from Lablab purpureus and NGR76 from Phaseolus vulgaris formed similar nodule-like structures on Brassica spp. The size of these structures on plants in pots were large, often reaching 10 mm in diameter.The frequency of inoculated Brassica plants in pots with nodule-like structures was 25–50%, depending on the inoculum strain. The inheritable nature of factors involved in the formation of the nodule-like structures was demonstrated when the structures occurred on 100% of inoculated B. napus seedlings derived from plants with the nodule-like structures.Nodule-like structures occurred without, but not with, the application of a cellulase-pectolyase-PEG treatment to the roots. Attempts to isolate Bradyrhizobium or Rhizobium from the nodule-like structures failed. Internal infection of these structures could not be detected using either the light or electron microscope. The inoculum strains of root-nodule bacteria were detected in high numbers in the rhizosphere of plants 5 months after inoculation. On agar plates bacterial colonies could be seen, with undiminished growth, over the surface of the agar extending to the root surface. However, ground root tissue of Brassica was toxic to Bradyrhizobium strains. This suggested that Bradyrhizobium strains would not survive after infecting the roots of Brassica spp. Nitrogen fixation was associated with high rhizosphere populations of Azospirillum and not with Bradyrhizobium induced nodule structures of Brassica spp.     

Enhancement of sporulation in species of Bipolaris, Curvularia, Drechslera, and Exserohilum by growth on cellulose-containing substrates

Nine species of Bipolaris, Curvularia, Drechslera, and Exserohilum were compared for sporulation on agar media and for enhancement of sporulation by growth on four cellulose-containing substrates (index card, filter paper, cheesecloth, cotton fabric). On two natural and one synthetic agar media, sporulation varied from profuse to nonexistent among three isolates of each species. Growth of all species on cellulose substrates resulted in large and significant increases in sporulation. Growth on index card pieces often provided the greatest increases, but no single substrate was superior for all species, and significant substrate × isolate interactions were observed within species. Overlay of filter paper onto whole colonies in agar plates resulted in 2 to 18-fold increases in sporulation for eight of nine species and production of spores in sufficient quantity for most experimental purposes. Overlay of soil dilution plates with filter paper to promote sporulation of colonies enabled detection of B. spicifera, B. hawaiiensis, C. lunata, and E. rostratum at relatively low population levels (≤1.3 × 10³ colony-forming units per gram of soil) in samples of a naturally infested soil. Results indicate that enhancement of sporulation by growth of species of Bipolaris, Curvularia, Drechslera, and Exserohilum on cellulose substrates may facilitate (i) their identification in culture, (ii) production of spores at relatively high concentrations, and (iii) detection and enumeration of these fungi in soil.     

Plate ethanol-screening assay for selection of the Pichia stipitis and Hansenula polymorpha yeast mutants with altered capability for xylose alcoholic fermentation

A new method for the selection of Pichia stipitis and Hansenula polymorpha yeast mutants with altered capability to ferment xylose to ethanol was developed. The method is based on the ability of P. stipitis and H. polymorpha colonies to grow and produce ethanol on agar plates with xylose as the sole carbon and energy source. Secreted ethanol, in contrast to xylose, supports growth of cells of the indicator xylose-negative strains (the wild-type strain of Saccharomyces cerevisiae or Δxyl1 mutant of H. polymorpha) mixed with agar medium. The size of the tester culture-growth zone around xylose-grown colonies appeared to be dependent on the amount of secreted ethanol. Mutants with altered (decreased or elevated) ethanol production in xylose medium have been isolated using this method. The mutants exhibited pleiotropic alterations in enzymatic activities of the intermediary xylose metabolism.     

内蒙古典型草原区狭颅田鼠集群数量与被捕食风险的关系

2005年9月15日—30日,在内蒙古锡林郭勒盟西乌珠穆沁旗的典型草原上研究了狭颅田鼠(Microtus gregalis)冬季集群与来自艾虎(Mustela eversmanni)的捕食风险。采用鼠洞口数量作为狭颅田鼠集群大小的指标,分析了艾虎对不同大小狭颅田鼠集群的捕食优先选择偏好。对实验样地内狭颅田鼠的洞群洞口数进行了调查统计(样地内总共涉及102个狭颅田鼠有效洞群),并计数此期间的艾虎粪便堆数以及攻击掘开狭颅田鼠洞群的情况。运用非参数的Mann-Whitney U检验法进行数据分析,结果表明:从艾虎遗留的粪便痕迹来看,没有被艾虎访问过的田鼠洞群与被艾虎访问过的洞群之间差异达到极显著水平;另外,从狭颅田鼠洞口被艾虎掘开的痕迹来分析,没有被艾虎挖掘的洞群与被艾虎挖掘的洞群之间的差异也达到极显著的水平;另外,随着田鼠洞群洞口数量的增加,出现艾虎粪便和掘洞的频次和概率就越高。表明艾虎对狭颅田鼠集群洞口数的选择差异性非常显著,明显倾向于选择在洞口数量多的狭颅田鼠洞群停留,同时也更倾向于掘开洞口数量较高的狭颅田鼠洞群作为捕食对象。     

TWO DISTINCT COLONIAL MORPHOTYPES OF AMPHORA COFFEAEFORMIS (BACILLARIOPHYCEAE) CULTURED ON SOLID MEDIA1

When cultured on different types of solid media, the marine-fouling diatom Amphora coffeaeformis (Ag.) Kütz. consistently formed two distinct colonial morphotypes named tight and fuzzy. Tight colonies were comprised mainly of small, morphologically distorted, nonmotile cells, whereas morphologically normal and highly motile cells formed the fuzzy colonies. Cells from tight colonies were less adherent to glass, grew more slowly in liquid media, and had a slightly decreased viability on plates with copper than cells from fuzzy colonies. Whereas the protein profiles of the two types of cells were nearly identical in polyacrylamide gels stained with Coomassie blue, cells from tight colonies produced a significantly lower amount of a protease-resistant, low M_r polysaccharide or glycoconjugate as detected in silver-stained gels. The frequency of appearance of the fuzzy and tight morphotypes was not influenced by the mode of nutrition or the type of substratum to which the algal cells adhered. However, certain formulations of solid medium and the presence of growth-inhibitory concentrations of copper in agar plates favored the formation of tight colonies. Due to their frequencies and patterns of appearance, it was clear that the two naturally formed morphotypes were not the consequence of spontaneous mutations, genetic rearrangement, or selection of stable natural variants, and we have hypothesized that they were linked to a normal physiological behavior. The tight colonial morphotype was used as a valuable marker to screen for true motility/adhesion mutants within an ultraviolet-mutagenized population of A. coffeaeformis. Seven mutants were isolated that were non-motile on agar plates, poorly adherent to glass, and distinguished from naturally formed cells from tight colonies by their inability to form fuzzy colonies upon subculture on solid media.     

Mediterranean karst springs: diatom biodiversity hotspots under the pressure of hydrological fluctuation and nutrient enrichment

Abstract

Mediterranean karst springs are affected by strong climatic seasonality, with long, dry and hot summers and are increasingly threatened by anthropogenic pressures. In Sardinia (western Mediterranean Sea, Italy), they are largely unexplored and their biocoenoses are mostly unknown. The diatom flora from two substrates (cobbles and macrophytes) in eight springs of different areas of the island was investigated in summer 2016 and winter 2017. A total of 162 diatom taxa (58 genera) were found of which 27 (17 genera) only on cobbles and 26 (18 genera) only on macrophytes. The most abundant species from both substrates were Achnanthidium minutissimum, Amphora indistincta, Amphora pediculus, Cocconeis euglypta, Planothidium frequentissimum and P. lanceolatum. Overall, 67 taxa (40 genera) were recorded in single sites and some of these taxa showed high affinity with specific environmental conditions. Hydrological stability (water flow permanence), discharge and nutrients were the main environmental factors influencing diatom assemblages. Our results suggest that diatoms can reflect important local factors related to the vulnerability of these spring ecosystems and underline the importance of their preservation both for biodiversity and water quality maintenance.     

Cloning and characterization of endosymbiotic algae isolated fromParamecium bursaria

Summary The green parameciumParamecium bursaria has many endosymbiotic algae in its cytoplasm. Here, we cloned and characterized endosymbiotic algae fromP. bursaria and examined in detail the interaction between the cloned algae and algae-free paramecia. Homogenates ofP. bursaria were cultured on agar plates containing various kinds of media to establish clones of the endosymbiotic algae. Many algal colonies were obtained from poorly nutritious medium (CA medium) after one month in culture. Algae were picked up from these colonies and inoculations were repeated 9 times on agar plates containing CA medium. On enriched media including bacto-peptone, glucose, proteose-peptone and/or yeast extract, however, bacteria and mold grew rapidly and no algal colonies were formed. When the cloned algae were cultured in liquid CA medium, they grew faster than on agar plates and the numbers stayed constant at 1 × 10⁷ algae/ml after 7 days in culture. They revealed high infectivity to algae-free paramecia, and an incubation period of 24 h and at least 1 × 10³ algae/paramecium were required to achieve successful infection (80–90%). The growth and infection rate did not change through 74 repeated inoculations of algae in liquid CA medium. Optical microscopic observations revealed marked morphological similarity between endosymbiotic algae and free-livingChlorella, but the latter showed no infectivity to algae-free paramecia. The cloned endosymbiotic algae presented here will provide an excellent opportunity to examine the mechanism of symbiont-host interaction.     

Polymorphism in gloeotaenium (Chlorococcales,Chlorophyceae)

Morphological variations of Gloeotaenium loitlesbergarianum Hansgirg were studied both in cultures and in nature. In cultures, the alga exhibits considerable variation in the number of cells per colony, ranging from unicells to colonies with more than four cells. The characteristic band was also absent in cultures. In nature, colonies resembling the culture material of Gloeotaenium also occur. The morphology of the alga varies depending on the nature and composition of the nutrients available. The study shows that Gloeotaenium may exhibit polymorphism in nature as well.     

Gastric colonization withCandida albicans

This is the first report on the isolation ofCryptococcus neoformans from pigeon droppings in China and their serotypes.C. neoformans colonies which produced brown colonies on caffeic acid-cornmeal agar were found in Twenty-five out of thirty-six samples of pigeon droppings. Fifty-one colonies randomly picked from the positive samples were identified asC. neoformans by a commercially available kit for carbon source assimilation test and Christensen's urea agar. Forty (78%) out of the 51 strains were serotyped as A and 11 (22%) as AD. At the same time, seventeen out of nineteen clinical isolates were serotyped as A and 2 as B. There are three findings in our results. One is that onlyC. neoformans var.neoformans strains could be isolated from pigeon droppings, although the varietygattii strains were found in the clinical isolates obtained in the same geographic site in China. The second is that serotype A strains were most frequently seen in natural and clinical materials in the southeast part of China, and serotype AD strains were isolated in pigeon droppings but not in clinical materials. The third is that the coexistence of serotype A and AD cells ofC. neoformans strains in same samples of pigeon droppings were observed.     

Inhibition of copepod feeding by exudates and transparent exopolymer particles (TEP) derived from a Phaeocystis globosa dominated phytoplankton community

We investigated if (1) dissolved compounds excreted by Phaeocystis globosa and (2) transparent exopolymer particles (TEP) formed from carbohydrates excreted into the water affect the feeding of nauplii and females of the calanoid copepod Temora longicornis during a P. globosa bloom. Copepod grazing on the diatom Thalassiosira weissflogii in the presence of these possible grazing deterrents was measured during three successive weeks of a mesocosm study, simulating the development of a P. globosa bloom. Our results demonstrate no indication for the presence of feeding deterrents in the dissolved phase, but a strong inhibitory effect of transparent exopolymer particles (TEP) on the consumption of algae by both nauplii and adult copepods. The inhibitory effect of TEP was connected to the accumulation of DOM during the progress of the bloom. We suggest that a reduction in the grazing pressure of zooplankton may increase the survival of the liberated single cells during disruption of colonies and allow seeding populations to persist. Furthermore, P. globosa reduces the trophic efficiency of the food web not only by withdrawal of its colonies from grazing but also by a relaxation of the grazing pressure on co-occurring phytoplankton and by alteration of the food web structure via TEP production.     

Chemotaxonomy of theSymphytum officinale agg. (Boraginaceae)

In a chemotaxonomic study of the genusSymphytum pyrrolizidine alkaloids and triterpenes were used as chemotaxonomical markers. A micro-extraction methods was developed for screening compounds of very small pieces of herbarium material. The occurrence of the pyrrolizidine alkaloids symphytine and (acetyl-)lycopsamine is very general forSymphytum taxa. Echimidine is present in someS. officinale L. plants and inS. tanaicense Steven. The triterpene isobauerenol is present inS. officinale, S. bohemicum Schmidt,S. tanaicense and inS. officinale var.lanceolatum Weinm. The chemotaxonomic hypothesis, proposed byGadella and collaborators, based on the presence of the triterpene isobauerenol inS. officinale and its absence inS. asperum Lepech. and the presence of the pyrrolizidine alkaloid echimidine inS. asperum and its absence inS. officinale, can no longer be applied absolutely to theS. officinale species complex. The pyrrolizidine alkaloid and triterpene pattern ofS. officinale (2n = 24) andS. bohemicum (2n = 24) is identical.S. bohemicum is morphologically, cytologically and phytochemically very similar toS. officinale. Furthermore, it readily crosses with the white flowered W. European diploids ofS. officinale. Therefore it seems likely that these two taxa are conspecific.S. tanaicense shows a pyrrolizidine alkaloid and triterpene pattern similar toS. officinale (2n = 40). Also on morphological and cytological grounds they are very similar. It seems highly probable thatS. tanaicense is conspecific withS. officinale (2n = 40) and represents an intraspecific variant only.S. officinale var.lanceolatum contained no pyrrolizidine alkaloids but did contain isobauerenol. This feature points to an origin fromS. officinale.     

Comparison of four media for the isolation ofAspergillus flavus group fungi

Four agar media used to isolate aflatoxin producing fungi were compared for utility in isolating fungi in theAspergillus flavus group from agricultural soils collected in 15 fields and four states in the southern United States. The four media wereAspergillus flavus andparasiticus Agar (AFPA, 14), the rose bengal agar described by Bell and Crawford (BCRB; 3), a modified rose bengal agar (M-RB), and Czapek's-Dox Agar supplemented with the antibiotics in BC-RB (CZ-RB). M-RB was the most useful for studying the population biology of this group because it permitted both identification of the greatest number ofA. flavus group strains and growth of the fewest competing fungi. M-RB supported an average of 12% moreA. flavus group colonies than the original rose bengal medium while reducing the number of mucorales colonies and the number of total fungi by 99% and 70%, respectively. M-RB was successfully employed to isolate all three aflatoxin producing species,A. flavus, A. parasiticus andA. nomius, and both the S and L strains ofA. flavus. M-RB is a defined medium without complex nitrogen and carbon sources (e.g. peptone and yeast extract) present in BC-RB. M-RB should be useful for studies on the population biology of theA. flavus group.Abbreviations M-RB Modified Rose Bengal Agar - CZ-RB Czapeks Rose Bengal Agar - BC-RB Bell and Crawford's Rose Bengal Agar - AFPA Aspergillus flavus andparasiticus agar     

Independent and interactive effects of nutrients and grazers on benthic algal community structure

Algal responses to nutrients, grazing by Helicopsyche borealis, and concurrent grazing by Helicopsyche and Baetis tricaudatus were examined in recirculating stream chambers. Alagl communities, dominated by Achnanthes minutissima, Cocconeis placentula, and Synedra ulna, were primarily phosphorus-limited. Algal populations responded after only 6 days of nutrient enrichment. Initially, both the adnate diatom Cocconeis and erect diatom Synedra showed positive response to nutrient enrichment. Accumulation of algal biomass between day 3 and 6 in the P enriched treatment was resulted primarily from the growth of Synedra, an overstory rosette-like diatom colony. Such a shift in dominant growth from adnate to erect diatoms is a general phenomenon in periphyton succession in the absence of disturbance. Algal species showed differential responses to an increase of Helicopsyche densities. The accrual rate of Achnanthes continuously decreased with increasing grazer densities. The accrual rates of both Cocconeis and Synedra declined but reached plateaus between medium and high grazing densities. Baetis effectively and exclusively depressed Synedra and had no significant impact on Cocconeis. After concurrent grazing, algal communities were mainly dominated by Cocconeis (approximately 80% of total algal biovolume). The grazer' s mouth structures, grazing efficiencies, and mobility may account for the differential effects of concurrent grazing on algal communities. Significant interactive effects of P and grazing by Helicopsyche indicated that both nutrient addition and grazing may exert significant impact on algal communities. However, grazing may have a much stronger effect on algae than nutrients. Our results indicate that enhancement of algal biomass by P was dampened by grazing activities and that P had no effect on algal biomass in the presence of grazers.     

Settlement, early growth and survival of Haliotis rubra in response to different algal species

Five diatom species were isolated from settlementplates at Southern Ocean Mariculture, Victoria,Australia (Navicula sp., Naviculajeffreyi, Cylindrotheca closterium, Cocconeis sp., Amphora sp.) and tested insettlement experiments with Haliotis rubralarvae. Settlement was very low on single speciesdiatom films and varied between 1%–6%. Depending onthe species combination larvae preferred to settle onfilms with mixed diatom species than single speciesfilms. The highest settlement was achieved with amixed film of Navicula sp. and Amphora sp.Five and ten-day-old germlings of Sporolithondurum induced settlement of the abalone Haliotisrubra. However, the settlement rate was significantlylower on germlings than on the whole thallus of thealga. Germlings inoculated with the diatom Navicula sp. induced higher settlement than films ofthe diatom species alone. High settlement of up to52% was also achieved with germlings of the greenalga Ulvella lens. Settlement was reduced onU. lens squares inoculated with the diatom Navicula sp. but higher than on films of the diatomalone. The settlement rate was higher if plates withU. lens were previously grazed by juvenileabalone.Post-larval growth rates were higher on monospecificdiatom films than on U. lens or on S.durum. The best growth rate was obtained with Navicula sp. U. lens and S. durum areboth good settlement inducers, but are notsufficient to support rapid growth of young H.rubra post-larvae. Survival was low on U. lensand on the diatom C. closterium. We suggest thatcommercial nursery plates seeded with U. lenswill result in high and consistent settlement, whilean inoculum with Navicula sp. will ensuresufficient food for rapid growth of the post-larvae.     

A new species of <Emphasis Type="Italic">Discostroma</Emphasis> and its anamorph <Emphasis Type="Italic">Seimatosporium</Emphasis> with two morphological types of conidia,isolated from the stems of <Emphasis Type="Italic">Paeonia suffruticosa</Emphasis>

Conidia of two morphologically different types, one with a basal appendage only and the other with appendage at both ends, were isolated from the stems of Paeonia suffruticosa. Single conidial isolates of both types of conidia yield identical colonies, which then produced both types of conidia on agar media depending on temperature, thus showing that both types of conidia belong to the same fungus. Seimatosporium botan is described based on its morphological characteristics. The teleomorph of the fungus was first found on sterilized P. suffruticosa stems placed on water agar, when grown at 5°C for 2 months in 12-h photoperiod. Discostroma botan is described for this fungus. The teleomorph is also found on the same host in the field.     

Fungal Infection of Mantis Shrimp (<Emphasis Type="Italic">Oratosquilla oratoria</Emphasis>) Caused by Two Anamorphic Fungi Found in Japan

Two fungal pathogens of the mantis shrimp (Oratosquilla oratoria) in Yamaguchi and Aichi Prefectures, Japan are described as the new species Plectosporium oratosquillae and Acremonium sp. (a member of the Emericellopsis marine clade). Both fungi infect the gills of the mantis shrimp, which become brown or black due to melanization. The former species is characterized by its slow growth on artificial seawater yeast extract peptone glucose (PYGS) agar, pale yellow to pale orange or grayish yellow colonies, short cylindrical solitary phialides with a wavy tip, and one-celled ellipsoidal conidia. Although lacking the two-celled conidia demonstrated by the type species Plectosporium tabacinum, the taxonomic placement of the new species was confirmed by DNA sequence analysis of the internal transcribed spacer (ITS) region of ribosomal DNA (ITS1, 5.8S rDNA and ITS2). Acremonium sp., the other causal pathogen, differs from P. oratosquillae by its fast growth on PYGS agar, pale orange to salmon-colored colonies, long, slender conidiophores consisting of solitary phialides with tips lacking an undulate outline, and typically cylindrical conidia. Analysis of ITS and β-tubulin gene sequences placed this fungus within the phylogenetically distinct Emericellopsis (anam. Acremonium) marine clade. Various physiological characteristics of both pathogens were also investigated. This is the first report of a fungal infection found on the mantis shrimp in Japan.     

Isolation of Beauveria bassiana and Metarhizium anisopliae var. anisopliae from Boophilus microplus tick (Canestrini, 1887), in Rio de Janeiro State,Brazil

The objective of this work were to isolate and identify strains of entomopathogenic fungi from ingurgitated female Boophilus microplus ticks, collected from the soil in the municipality of Paracambi, Rio de Janeiro State, Brazil. The ingurgitated females were inoculated in the selective medium oat dodine agar (oda), where 49 colonies of Beauveria bassiana (71%) and 20 of Metarhizium anisopliae var. anisopliae (29%) were isolated. These isolated strains characterize for the first time in Brazil the natural occurrence of these species of fungi in this tick, and will be used to conduct bioassays to evaluate the pathogenicity and virulence of these strains for ticks of the genus Boophilus microplus. This revised version was published online in June 2006 with corrections to the Cover Date.