First evidence of ranavirus in native and invasive amphibians in Colombia.

Ranaviruses can cause mass mortality events in amphibians, thereby becoming a threat to populations that are already facing dramatic declines. Ranaviruses affect all life stages and persist in multiple amphibian hosts. The detrimental effects of ranavirus infections to amphibian populations have already been observed in the UK and in North America. In Central and South America, the virus has been reported in several countries, but the presence of the genus Ranavirus (Rv) in Colombia is unknown. To help fill this knowledge gap, we surveyed for Rv in 60 species of frogs (including one invasive species) in Colombia. We also tested for co-infection with Batrachochytrium dendrobatidis (Bd) in a subset of individuals. For Rv, we sampled 274 vouchered liver tissue samples collected between 2014 and 2019 from 41 localities covering lowlands to mountaintop páramo habitat across the country. Using quantitative polymerase chain reaction (qPCR) and end-point PCR, we detected Rv in 14 individuals from 8 localities, representing 6 species, including 5 native frogs of the genera Osornophryne, Pristimantis and Leptodactylus, and the invasive American bullfrog Rana catesbeiana. Bd was detected in 7 of 140 individuals, with 1 co-infection of Rv and Bd in an R. catesbeiana specimen collected in 2018. This constitutes the first report of ranavirus in Colombia and should set off alarms about this new emerging threat to amphibian populations in the country. Our findings provide some preliminary clues about how and when Rv may have spread and contribute to understanding how the pathogen is distributed globally.

Presence of invasive American bullfrogs may reduce infectious disease in a native frog species.

Amphibians breeding in aquatic environments may encounter a myriad of threats during their life cycle. One species known to prey on native amphibians in aquatic habitats is the invasive North American bullfrog Lithobates catesbeianus, which, besides being a voracious predator and competitor, often acts as a pathogen carrier and disease superspreader because it tolerates high infection loads of the frog-killing fungus Batrachochytrium dendrobatidis (Bd). Here, we hypothesized that the presence of the bullfrogs in microcosms should either (1) decrease Bd disease severity in native frog species by discouraging them from using the aquatic environment, or (2) increase the mortality of the native species. We tested these 2 mutually exclusive hypotheses by co-housing the snouted treefrog Scinax x-signatus (native to our study area) with L. catesbeianus in the laboratory, exposing them to Bd, and using qPCR analysis to quantify the resulting Bd infection loads in the native frogs. Our experiment had the following replicated treatments: (1) native-only treatment (3 individuals of S. x-signatus), (2) native-predominant treatment (2 S. x-signatus + 1 L. catesbeianus), and (3) exotic-predominant treatment (1 S. x-signatus + 2 L. catesbeianus). We found that Bd infection loads in the native S. x-signatus were highest in the native-only treatment, and lowest in the exotic-predominant treatment, indicating that bullfrogs may discourage native frogs from occupying the aquatic habitat, thus reducing encounter rates between native frogs and the waterborne pathogen. This effect could be driven by the bullfrogs' predatory behavior and their high philopatry to aquatic habitats. Our results highlight that predation risk adds to the complexity of host-species interactions in Bd epidemiology.

Influence of different periods of pre-slaughter fasting on microbiological quality of bullfrog carcasses (Lithobates catesbeianus) / [Influência de diferentes períodos de jejum pré-abate na qualidade microbiológica de carcaças de rã-touro (Lithobates catesbeianus)]

The aim of this study was to evaluate the influence of different periods of pre-slaughter fasting (F1: 2 to 24 hours and F2: 48 to 72 hours) on the counts of hygiene indicator microorganisms and the presence of Salmonella spp. in carcasses of bullfrogs. Two different stages of the slaughter process were analyzed: after bleeding (A) and after the final carcasses cleaning (B). Samples from each fasting period were analyzed to count hygiene indicator microorganisms (n=30) and Salmonella spp. (n=140). For aerobic mesophilic microorganisms, the variation in fasting periods caused a reduction of 0.69 log10 CFU / g (P<0.05) in F2 when compared to F1 at point B of the slaughter. Coliforms at 35º C and Escherichia coli showed no differences (P >0.05) between the fasting analyzed periods. Considering the presence of E. coli, it was observed that F2 resulted in a reduction of 30% (P<0.05) positivity on point B. For Salmonella spp., the results showed that F2 contributed to an 11.5% reduction in the presence of this bacteria at point B. (P<0.05). Therefore, it is concluded that 48 to 72 hours of pre-slaughter fasting resulted in a positive impact on the microbiological quality of bullfrog carcasses.(AU)

O objetivo deste estudo foi avaliar a influência de diferentes períodos de jejum pré-abate (F1: duas a 24 horas e F2: 48 a 72 horas) nas contagens de micro-organismos indicadores de higiene e na presença de Salmonella spp. em carcaças de rãs-touro. Foram analisadas duas etapas do processo de abate: após a sangria (A) e após a toalete final da carcaça (B). As amostras de cada período de jejum foram utilizadas para contagem de indicadores de higiene (n = 30) e Salmonella spp. (n = 140). Para aeróbios mesófilos, a variação no tempo de jejum causou uma redução de 0,69 log10 UFC/g (P<0,05) em F2 quando comparado a F1 na etapa B do abate. Os coliformes a 35ºC e Escherichia coli não apresentaram diferenças (P>0,05) entre os dois períodos de jejum analisados. Considerando a presença de E. coli, F2 resultou em uma redução de 30% (P<0,05) de positividade na etapa B. Para Salmonella spp., os resultados mostraram que F2 contribuiu para uma redução de 11,5% na presença desse micro-organismo na etapa B. Portanto, conclui-se que 48 a 72 horas de jejum pré-abate tiveram um impacto positivo na qualidade microbiológica das carcaças de rã-touro.(AU)

Skin-associated lactic acid bacteria from North American bullfrogs as potential control agents of Batrachochytrium dendrobatidis.

The fungal pathogen Batrachochytrium dendrobatidis (Bd) is the causative agent of chytridiomycosis and has been a key driver in the catastrophic decline of amphibians globally. While many strategies have been proposed to mitigate Bd outbreaks, few have been successful. In recent years, the use of probiotic formulations that protect an amphibian host by killing or inhibiting Bd have shown promise as an effective chytridiomycosis control strategy. The North American bullfrog (Lithobates catesbeianus) is a common carrier of Bd and harbours a diverse skin microbiota that includes lactic acid bacteria (LAB), a microbial group containing species classified as safe and conferring host benefits. We investigated beneficial/probiotic properties: anti-Bd activity, and adhesion and colonisation characteristics (hydrophobicity, biofilm formation and exopolysaccharide-EPS production) in two confirmed LAB (cLAB-Enterococcus gallinarum CRL 1826, Lactococcus garvieae CRL 1828) and 60 presumptive LAB (pLAB) [together named as LABs] isolated from bullfrog skin.We challenged LABs against eight genetically diverse Bd isolates and found that 32% of the LABs inhibited at least one Bd isolate with varying rates of inhibition. Thus, we established a score of sensitivity from highest (BdGPL AVS7) to lowest (BdGPL C2A) for the studied Bd isolates. We further reveal key factors underlying host adhesion and colonisation of LABs. Specifically, 90.3% of LABs exhibited hydrophilic properties that may promote adhesion to the cutaneous mucus, with the remaining isolates (9.7%) being hydrophobic in nature with a surface polarity compatible with colonisation of acidic, basic or both substrate types. We also found that 59.7% of LABs showed EPS synthesis and 66.1% produced biofilm at different levels: 21% weak, 29% moderate, and 16.1% strong. Together all these properties enhance colonisation of the host surface (mucus or epithelial cells) and may confer protective benefits against Bd through competitive exclusion. Correspondence analysis indicated that biofilm synthesis was LABs specific with high aggregating bacteria correlating with strong biofilm producers, and EPS producers being correlated to negative biofilm producing LABs. We performed Random Amplified Polymorphic DNA (RAPD)-PCR analysis and demonstrated a higher degree of genetic diversity among rod-shaped pLAB than cocci. Based on the LAB genetic analysis and specific probiotic selection criteria that involve beneficial properties, we sequenced 16 pLAB which were identified as Pediococcus pentosaceus, Enterococcus thailandicus, Lactobacillus pentosus/L. plantarum, L. brevis, and L. curvatus. Compatibility assays performed with cLAB and the 16 species described above indicate that all tested LAB can be included in a mixed probiotic formula. Based on our analyses, we suggest that E. gallinarum CRL 1826, L. garvieae CRL 1828, and P. pentosaceus 15 and 18B represent optimal probiotic candidates for Bd control and mitigation.

Bullfrog farms release virulent zoospores of the frog-killing fungus into the natural environment.

Bullfrog farming and trade practices are well-established, globally distributed, and economically valuable, but pose risks for biodiversity conservation. Besides their negative impacts on native amphibian populations as an invasive species, bullfrogs play a key role in spreading the frog-killing fungus Batrachochytrium dendrobatidis (Bd) in the natural environment. Bullfrogs are tolerant to Bd, meaning that they can carry high infection loads without developing chytridiomycosis. To test the potential of bullfrog farms as reservoirs for diverse and virulent chytrid genotypes, we quantified Bd presence, prevalence and infection loads across approximately 1,500 farmed bullfrogs and in the water that is released from farms into the environment. We also described Bd genotypic diversity within frog farms by isolating Bd from dozens of infected tadpoles. We observed individuals infected with Bd in all sampled farms, with high prevalence (reaching 100%) and high infection loads (average 71,029 zoospore genomic equivalents). Average outflow water volume from farms was high (60,000 L/day), with Bd zoospore concentration reaching approximately 50 million zoospores/L. Because virulent pathogen strains are often selected when growing in tolerant hosts, we experimentally tested whether Bd genotypes isolated from bullfrogs are more virulent in native anuran hosts compared to genotypes isolated from native host species. We genotyped 36 Bd isolates from two genetic lineages and found that Bd genotypes cultured from bullfrogs showed similar virulence in native toads when compared to genotypes isolated from native hosts. Our results indicate that bullfrog farms can harbor high Bd genotypic diversity and virulence and may be contributing to the spread of virulent genotypes in the natural environment. We highlight the urgent need to implement Bd monitoring and mitigation strategies in bullfrog farms to aid in the conservation of native amphibians.

Tuberculosis caused by Mycobacterium bovis infection in a captive-bred American bullfrog (Lithobates catesbeiana).

BACKGROUND: Tuberculosis is widely known as a progressive disease that affects endothermic animals, leading to death and/or economical losses, while mycobacterial infections in amphibians are commonly due to nontuberculous mycobacteria. To the authors' knowledge, this report describes the first case of bovine tuberculosis in a poikilothermic animal. CASE PRESENTATION: An adult female captive American bullfrog (Lithobates catesbeianus Shaw, 1802) died in a Brazilian aquarium. Multiple granulomas with acid-fast bacilli were observed in several organs. Identification of Mycobacterium bovis was accomplished by culture and PCR methods. The other animals from the same enclosure were euthanized, but no evidence of mycobacterial infection was observed. CONCLUSIONS: The American bullfrog was introduced in several countries around the world as an alternative husbandry, and its production is purposed for zoological and aquarium collections, biomedical research, education, human consumption and pet market. The present report warns about an episode of bovine tuberculosis in an amphibian, therefore further studies are necessary to define this frog species' role in the epidemiology of M. bovis.

Nisin Z produced by Lactococcus lactis from bullfrog hatchery is active against Citrobacter freundii, a red-leg syndrome related pathogen.

Lactococcus lactis subsp. lactis CRL 1584 isolated from a bullfrog hatchery produces a bacteriocin that inhibits both indigenous Citrobacter freundii (a Red-Leg Syndrome related pathogen) and Lactobacillus plantarum, and Listeria monocytogenes as well. Considering that probiotics requires high cell densities and/or bacteriocin concentrations, the effect of the temperature on L. lactis growth and bacteriocin production was evaluated to find the optimal conditions. Thus, the growth rate was maximal at 36 °C, whereas the highest biomass and bacteriocin activity was achieved between 20 and 30 °C and 20-25 °C, respectively. The bacteriocin synthesis was closely growth associated reaching the maximal values at the end of the exponential phase. Since bacteriocins co-production has been evidenced in bacterial genera, a purification of the bacteriocin/s from L. lactis culture supernatants was carried out. The active fraction was purified by cationic-exchange chromatography and then, a RP-HPLC was carried out. The purified sample was a peptide with a 3353.05 Da, a molecular mass that matches nisin Z, which turned out to be the only bacteriocin produced by L. lactis CRL 1584. Nisin Z showed bactericidal effect on C. freundii and L. monocytogenes, which increased in the presence L-lactic acid + H2O2. This is the first report on nisin Z production by L. lactis from a bullfrog hatchery that resulted active on a Gram-negative pathogen. This peptide has potential probiotic for raniculture and as food biopreservative for bullfrog meat.

Cardiac adaptations of bullfrog tadpoles in response to chytrid infection.

The chytrid fungus Batrachochytrium dendrobatidis (Bd) can result in heart failure in Bd-susceptible species. Since Bd infection generally does not cause mortality in North American bullfrogs, the aim of this work was to verify whether this species presents any cardiac adaptation that could improve the tolerance to the fungus. Thus, we analyzed tadpoles' activity level, relative ventricular mass, ventricle morphology, in loco heart frequency, and in vitro cardiac function. The results indicate that infected animals present an increase in both ventricular relative mass and in myofibrils' incidence, which accompanied the increase in myocytes' diameter. Such morphological alterations enabled an increase in the in vitro twitch force that, in vivo, would result in elevation of the cardiac stroke volume. This response requires much less energy expenditure than an elevation in heart frequency, but still enables the heart to pump a higher volume of blood per minute (i.e., an increase in cardiac output). As a consequence, the energy saved in the regulation of the cardiac function of Bd-infected tadpoles can be employed in other homeostatic adjustments to avoid the lethal effect of the fungus. Whether other species present this ability, and to what extent, remains uncertain, but such possible interspecific variability might explain different mortality rates among different species of Bd-infected amphibians.

Characterization of a bacteriocin produced by Lactococcus lactis subsp. lactis CRL 1584 isolated from a Lithobates catesbeianus hatchery.

Lactococcus lactis CRL 1584 isolated from a Lithobates catesbeianus hatchery inhibits the growth of Citrobacter freundii (a bullfrog pathogen) and Listeria monocytogenes by a synergistic effect between lactic acid, hydrogen peroxide and a bacteriocin-like molecule. The chemical characterization of the bacteriocin in cell-free supernatants indicates that it has a proteinaceous nature. Hexadecane and ethyl acetate did not modify the bacteriocin activity, while 10 and 20 % (v/v) chloroform decreased the activity by 29 and 43 %, respectively. The antimicrobial peptide was heat stable since 85 % of residual activity was detected when neutralized supernatants were heated at 80 °C for 30 min. Moreover, no bacteriocin inactivation was observed when supernatants were kept at -20 °C for 3 months. The synthesis of the bacteriocin was associated with bacterial growth, highest production (2,100 AU/ml) being detected at the end of the exponential growth phase. At pH ranges of 5-6.5 and 5.0-5.5 the inhibitory molecule was stable when stored for 2 days at 4 and 25 °C, respectively. Moreover, it had a bactericidal effect on L. monocytogenes and the ultrastructural studies of pathogenic cells revealed clumping of the cytoplasmic material, increased periplasmic space and cell wall modifications. The deduced amino acid sequence of the bacteriocin was identical to nisin Z and the genetic determinants for its production are harbored in the chromosome. These results, described for the first time in L. lactis from a bullfrog hatchery, will increase knowledge of the bacteriocin under study with a view to its potential inclusion in probiotics for raniculture or biopreservatives.

Novel, panzootic and hybrid genotypes of amphibian chytridiomycosis associated with the bullfrog trade.

Global amphibian declines are linked with the presence of specific, highly virulent genotypes of the emerging fungal disease chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd) known as the global panzootic lineage (Bd-GPL). The global trade in amphibians for human consumption is suspected to have facilitated emergence of the disease, but evidence to support this is largely lacking. Here, we investigated the role the Lithobates catesbeianus (North American bullfrog) trade in spreading Bd genotypes by comparing strains associated with L. catesbeianus to a global panel using 36 sequenced loci from multiple chromosomal regions. Most bullfrogs were infected with Bd-GPL genotypes, but we also detected novel, highly divergent Bd genotypes (Bd-Brazil) from a live bullfrog in a US market and from native Brazilian anurans in the Atlantic Forest where bullfrogs are widely farmed. Sexual reproduction was also detected for the first time in Bd in the form of a hybrid genotype between the Bd-GPL and Bd-Brazil lineages in the Atlantic Forest. Despite the demonstration that ribosomal RNA types in Bd fail to undergo concerted evolution (over 20 sequence types may be found in a single strain), the Bd-GPL and Bd-Brazil lineages form largely separate clusters of related internal transcribed spacer (ITS) RNA sequences. Using ITS sequences, we then demonstrate the presence of Bd-Brazil in Japan, primarily on invasive L. catesbeianus. The finding that Bd is capable of sexual reproduction between panzootic and endemic genotypes emphasizes the risk of international wildlife trade as a source of additional Bd epizootics owing to hybridization.

Errata: Isolamento e caracterização de possível agente patogênico causador de mortalidade em imagos de Rana catesbeiana Shaw, 1802 / Errata: Isolation and characterization of a possible pathogenic agent responsible for mortality in tadpoles of Rana catesbeiana Shaw, 1802 / Errata: Aislamiento y caracterización del posible agente patógeno causante de mortalidad en imagos de Rana catesbeiana Shaw, 1802

O presente estudo teve como objetivo isolar e caracterizar o patógeno causador de mortalidade em imagos de Rana catesbeiana, ocorrido no ranário experimental do Centro de Aquicultura da Unesp - Jaboticabal. Durante um surto de mortalidade, 20 imagos que apresentavam prostração, anorexia, pele ressecada e edemas cutâneos foram abatidos e submetidos ao procedimento padrão de necropsia. Foram assepticamente coletadas amostras de coração, figado, swab da cavidade abdominal e conteúdo do trato gastrintestinal, sendo posteriormente semeadas em meios de cultura seletivos para diferentes bactérias. Foi observado crescimento de colônias características de Escherichia coli em placas com meio seletivos EMB e Mac Conkey, as quais foram submetidas a séries bioquímicas para identificação e tipificação, que confirmaram se tratar de E. coli. Cepas obtidas a partir das colônias isoladas, foram semeadas em placas contendo ágar-sangue e apresentaram hemolise, o que caracteriza as bactérias como patogênicas, sendo assim a E.coli uma possível responsável pelo surto de mortalidade.

This study aimed isolating and characterizing the pathogen responsible for the mortality of Rana catesbeiana tadpoles that occurred in the Experimental Aquaculture Center of São Paulo State University (Unesp), Campus of Jaboticabal, Brazil. During a mortality outbreak, twenty tadpoles presenting prostration, anorexia, and dried and swollen skin were killed and submitted to post-mortem examination. Heart, liver, abdominal cavity, and bowel samples were aseptically collected. The materials were plated onto a selective medium for different bacteria. Colonies characteristic of Escherichia coli were seen in dishes with EMB and Mac Conkey selective mediums. Biochemical series identified and characterized the presence of E. coli. Strains obtained from isolated colonies were plated onto Petri dishes with Blood Agar, resulting in hemolysis, which is a characteristic of pathogenic bacteria. Therefore, E. coli could be ascribed as one of the responsible agents for the death outbreak.

El presente estudio tuvo como objetivo aislar y caracterizar el patógeno causante de mortalidad en imagos deRana catesbeiana, ocurrida en el ranario experimental del Centro de Acuicultura de la FCAV/UNESP-Jaboticabal, SP, Brasil. Duranteun brote de mortalidad, 20 imagos que presentaban postración, anorexia, piel reseca y edemas cutáneos fueron abatidos y sometidos alos procedimientos estándar de necropsia. Fueron asépticamente colectadas muestras de corazón, hígado, hisopos de la cavidadabdominal y contenido del tracto gastrointestinal, siendo posteriormente sembradas en medios de cultivo selectivos para diferentesbacterias. Fue observado crecimiento de colonias características de Escherichia coli en las placas con medio selectivo EMB y McConkey, las cuáles fueron sometidas a series bioquímicas para la identificación y tipificación, que confirmaron que se trataba de E.coli. Las cepas obtenidas a partir de las colonias aisladas fueron sembradas en placas de Agar Sangre y presentaron hemólisis, lo quecaracteriza las bacterias como patogénicas. De esta forma, la E. coli es la posible responsable por el brote de mortalidad.

Characterization of the beneficial properties of lactobacilli isolated from bullfrog (Rana catesbeiana) hatchery.

The present work addresses the isolation and partial identification of the microbial population of a R. catesbeiana hatchery in spring and summer as well as some beneficial properties of Lactobacillus strains isolated in different seasons and hatchery areas. The bacterial population was grouped into the following taxa: Lactobacillus spp., Pediococcus spp., Enterococcus faecalis and Ent. faecium, and Enterobacteriaceae (Enterobacter spp., Escherichia coli) while Pseudomonas aeruginosa and Staphylococcus epidermidis were isolated from frogs displaying red-leg syndrome. The Lactobacillus plantarum and L. curvatus strains isolated showed to inhibit the growth of red-leg syndrome associated pathogens and food-borne bacteria by organic acids. While L. plantarum CRL 1606 also inhibited red-leg syndrome related pathogens by hydrogen peroxide, meat spoilage bacteria were only inhibited by acidity. However, by using a MRS medium added with tetramethyl-benzidine and peroxidase, a high percentage of H(2)O(2)-producing lactobacilli were detected. The surface properties of Lactobacillus strains showed that a few strains were able to agglutinate ABO human erythrocytes, while the highest number of strains had a low to medium degree of hydrophobicity. This paper constitute the first study related to the beneficial properties of Lactobacillus isolated from a bullfrog hatchery, as well as the selection criteria applied to a group of strains, which could help to control or prevent bacterial infectious diseases in raniculture.

Occurrence of heavy metals and antibiotic resistance in bacteria from internal organs of american bullfrog (Rana catesbeiana) raised in Malaysia

A total of 40 bacteria have been successfully isolated from internal organs of the American bullfrog (Rana catesbeiana) raised in Malaysia, namely, eight isolates of Aeromonas spp., 21 of Edwardsiella spp., six of Flavobacterium spp. and five of Vibrio spp. In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3 percent) cases of sensitivity and 61 (7.3 percent) cases of partial sensitivity. Meanwhile, 297 (35.4 percent) bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR) index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. Additionally, high percentages of heavy metal resistance among these isolates were observed, with values ranging from 85.0 to 100.0 percent. The current results provided us information on bacterial levels of locally farmed bullfrogs exposed to copper, cadmium, chromium as well as 21 types of antibiotics.(AU)

A report of mycobacteriosis caused by Mycobacterium marinum in bullfrogs (Rana catesbeiana).

The occurrence of mycobacteriosis caused by Mycobacterium marinum in a commercial breeding farm of bullfrogs (Rana catesbeiana) in Rio de Janeiro, Brazil is described. Ten animals presented skin lesions on the head and extremities. These and 38 other asymptomatic adult animals from various tanks were killed and at necropsy disseminated granulomatous lesions were observed in the 10 clinically affected animals and in 16 (42.1%) of the asymptomatic frogs. Acid-fast bacilli were observed in all smears of the 10 symptomatic frogs and in all but one from the 16 asymptomatic animals with visceral lesions. Ten samples from the 25 positive animals were randomly selected for culture which yielded four isolates of fast-growing (<7 days) mycobacteria. Those purified isolates were characterised by biochemical traditional means as M. marinum. Identification of the strains was confirmed using reverse-phase high-performance liquid chromatography and a polymerase chain reaction (PCR) restriction enzyme analysis assay. It is suggested that M. marinum is an important agent of granulomatous disease in bullfrogs and that infected animals, even when asymptomatic, could act as reservoirs spreading the disease and contaminating other frogs in the farm.

Emerging pathogen of wild amphibians in frogs (Rana catesbeiana) farmed for international trade.

Chytridiomycosis is an emerging disease responsible for a series of global declines and extinctions of amphibians. We report the causative agent, Batrachochytrium dendrobatidis, in North American bullfrogs (Rana catesbeiana) farmed for the international restaurant trade. Our findings suggest that international trade may play a key role in the global dissemination of this and other emerging infectious diseases in wildlife.

Serotyping, proteinase and phospholipase production associated with the pathogenicity of Candida albicans strains isolated from frog meat

Quinze amostras de Candida albicans isoladas de coxas de räs (Rana catesbeiana, Shaw, 1802) comercializadas no Brasil, foram estudadas quanto ao sorotipo e fatores de virulência "in vitro" e "in vivo". A sorotipagem revelou predominância do sorotipo B. Todas as amostras estudadas foram produtoras de fosfolipases e 66,6 por cento produziram proteinases. No estudo da patogenicidade foram observados dois tipos de alteraçöes renais: uma do tipo agudo com abscessos corticais e outra do tipo crônico com pielonefrite e envolvimento unilateral

Leveduras associadas à porçäo terminal do intestino grosso de rana catresbeiana, shaw (1802), em diferentes fases de crescimento / Yeast associated with the terminal portion or large intestine of rana catesbiana, Shaw (1802), at defferent growth stage

Resumo: foram estudadas as porçöes terminais do intestino grosso de 64 räs da especie Rana catesbeiana criadas em confinamento. Esses animais foram separados em quatro fases distintas de crescimento, tendo sido alimentadoscom três tipos de raçäo. Foram isoladas 129, estirpes de leveduras identificadas através de métodos baseados em características macroiscópicas e fisiológicas, totalizando 35 estirpes identificadas em 24 espécies. Dentre as leveduras encontradas destacam-se as do gênero Candida pela frequência de isolamento sendo a espécie Candida rugosa a mais frequêntemente isolada nas quatro fases de cresciemnto, sugerindo tratar-se de levedura potencialmente patogênicas para o homem, bem como a importância da transiçäo do ambiente estritamente aquático para o terrestre, como provável fator de significado ecológico, responsável pela composiçäo da qualidadeda microbiota leveduriforme do trato alimentar destes animais (au)