Isolate R1 Research Articles

First record of Diplodia gallae causing branch cankers on declining scarlet oak (Quercus coccinea) in Virginia.

Members of Botryosphaeria s.l. have an extensive history as cankering pathogens of stressed and declining oak trees in the eastern United States (Ferreira et al. 2021). The host range, distribution, and virulence among two closely related species, Diplodia corticola and D. gallae, remains unclear (Brazee et al. 2023). On 15 August 2023, a survey was conducted at a declining natural hardwood site in Shenandoah County, Virginia (GPS coordinates 38.922089, -78.606125). One mature Quercus coccinea tree that displayed scorched leaf margins and branch dieback was felled and a cankered branch from the crown was sampled (Fig. 1A and B). A 4-mm piece of necrotic tissue was selected from the margin of the canker, disinfected with 2.5% NaOCl, again with 70% ethanol, and air-dried before being placed on half-strength acidified PDA medium (pH 4.8) and incubated in the dark at 22 ± 2°C. After 5 days, four colonies were transferred to full-strength PDA medium and incubated in the dark at 22 ± 2°C. After 10 days, all four colonies displayed thick, gray, floccose mycelium and pigmented hyphae (Fig. 1C). Mycelia was harvested from 10-day-old colonies with a sterile pin and DNA was extracted using a Qiagen DNeasy Plant Pro Kit (Germantown, MD) according to the manufacturer's instructions. A fragment of the internal transcribed spacer (ITS) and translation elongation factor 1-α (tef1) loci were amplified using ITS4/ITS5 (White et al. 1990) and EF1-728F/EF1-986R (Carbone and Kohn 1999) primer sets, respectively. The PCR amplicons were purified with ExoSap-IT (Affymetrix, Santa Clara, CA) and sequenced at Eurofins (Louisville, KY).&xa0; The raw nucleotide sequences were analyzed using Geneious 11.1.5 software (Biomatters, Auckland, NZ). All four colonies had identical ITS sequences. A 523 and 276-bp fragment of the ITS and tef1 loci, respectively, from isolate R1.2 was deposited into the GenBank database (accessions OR934498 and OR961039). A dataset of 43 strains consisting of 38,658 characters was aligned using MAFFT v7.49 (Katoh et al. 2013), and a concatenated ITS + tef1 maximum likelihood phylogenetic tree (1000 bootstraps) was built with PhyML 3.0 (Guindon et al. 2010) using the GTR substitution model. Isolate R1.2 was grouped with isolates of D. gallae although the species failed to form a well-supported clade (BS = 67) due to intraspecific variation (Fig. 1D). Koch's postulates were fulfilled by inoculating five healthy, containerized Q. coccinea trees (average stem caliper 5.3 cm) with isolate R1.2, with five plants as controls. After disinfecting the bark with 70% ethanol, a 0.5 mm section of the bark was removed 13 cm above the soil line with a sterile scalpel, and a 0.5 mm agar plug taken from the edge of a 10-day-old PDA culture was placed in the wound with the mycelium facing the cambial tissue, sealed with Parafilm, and maintained at 22 ± 4°C. The same procedure was performed on the control plants using sterile PDA plugs. After five weeks the bark was removed, and all five stems treated with R1.2 had necrotic lesions with a mean linear growth ([length+width]/2) of 9.2 ± 2.72 mm from the edge of the wound, which was significantly larger (P = 0.003) than the controls (1 ± 0.66 mm; Fig. 1E - L). Necrotic stem tissue was sampled as previously described, and the isolate recovered was confirmed as D. gallae based on morphology and 100% ITS sequence homology to isolate R1.2. D. gallae was not recovered from the control plants. In the United States, D. gallae has been isolated from Q. rubra and Q. velutina twig cankers in Maine, Massachusetts, New Hampshire, New York, and Vermont (Brazee et al. 2023). This is the first report of the species in Virginia causing branch cankers on Q. coccinea.

Identification of Potential Biofertilizer and Bioremediator Bacteria from Upland Soil Based on 16s rDNA Sequence Analysis

The long-term presence of synthetic pesticides on agricultural land can lead to a decline in soil fertility. Synthetic pesticides inhibit the activity of essential enzymes in the soil and suppress beneficial microbial populations for plants. One potential approach to mitigate the extent of contamination caused by synthetic pesticides involves the utilization of indigenous pesticide-resistant bacteria. Several upland soil bacteria from Banyumas Regency, Central Java Province, Indonesia, were successfully isolated from a previous study. The isolated bacteria have the potential to be developed as pesticide bio-remediators and biofertilizers. The bacterial isolates are expected to have characters that support plant growth through their ability to provide dissolved phosphate. However, the potential bacterial isolates need to be identified by molecular approaches. This study was conducted to identify bacterial isolates of GT2, SR1, SW1, and PA1 by 16S rDNA sequencing analysis. The results showed that isolate GT2 was placed within a group of reference strains of Bacillus proteolyticus, isolate SR1 was placed within a group of B. paramycoides, isolate SW1 was set within a group of B. albus, and isolate PA1 was placed within a group of Acidovorax delafieldii. The genetic distance of isolate GT2 and B. B. proteolyticus, isolate SR1 and B. paramycoides, isolate SW1 and B. albus were 0.0000 each, and isolate PA1 and A. delafieldii were 0.0061.

Endophytic Bacteria Showing Antioxidant Property from Periwinkle [Catharanthus roseus (L.) G. Don

The experiment was conducted in the year, April–December, 2020 at the Department of Microbiology, C. P. College of Agriculture, Sardarkrushinagar Dantiwada Agricultural University, Sardarkrushinagar, Gujarat, India to isolate and characterize promising antioxidant producing endophytic bacteria from periwinkle plant. Twenty four endophytic bacterial cultures derived from various parts of Catharanthus roseus (L.) G. Don were tested for total antioxidant capacity (TAC) and total phenolics content (TPC). The isolate R1 showed highest TAC (615.46 µg AAE mg-1 extract) followed by the isolate R2 (308.59 µg AAE mg-1 extract). Correlation coefficient observed between TAC and TPC was 0.7591, which shows that phenolic compounds were greatly responsible for antioxidant capacity of the bacterial isolates. 15 isolates showing higher TAC were studied for morphological and molecular characteristics. All the 15 isolates were rod shaped and were monobacillus. Nine isolates were Gram positive whereas 6 were Gram negative. 16S rDNA amplification using universal primers 27F and 27R produced a band of 1.5 kb. Restriction digestion of PCR products of all the isolates with tetracutter restriction enzymes AluI, TaqI, Hae III produced polymorphic diagnostic fingerprints. The dendrogram based on ARDRA profiling grouped the 15 bacteria into two groups (cluster A and cluster B) at a Jaccard’s similarity co-efficient of 0.83. Cluster A contained eleven bacterial isolates whereas cluster B had only four. The isolates R1 and R2 may serve as an excellent source of antioxidants and may be exploited for commercial production of antioxidants.

Novel QTL associated with Rhizoctonia solani Kühn resistance identified in two table beet × sugar beet F2:3 populations using a new table beet reference genome

AbstractThe necrotrophic fungus Rhizoctonia solani Kühn is a major concern for table beet (Beta vulgaris L. ssp. vulgaris) producers across the United States causing upward of 75% losses in severe instances. Thus far, there have been minimal efforts to incorporate host resistance to R. solani in table beet germplasm. To investigate the genetic control of R. solani resistance in table beet, we developed two mapping populations. Parents of the two populations were a Rhizoctonia‐susceptible table beet inbred W357A and a resistant sugar beet germplasm FC709‐2 (sugar beet resistance population, SBRP) and a Rhizoctonia‐resistant table beet inbred W364B and a susceptible sugar beet inbred FC901/C817 (table beet resistance population, TBRP). In Spring 2020, F2:3 families were evaluated for response to artificial inoculation with R. solani AG 2‐2 IIIB isolate R1 in replicated greenhouse experiments. This work also represents the first use of the W357B table beet reference genome, utilized here to align genotyping‐by‐sequencing reads to identify polymorphic markers. Using interval linkage mapping, we identified one quantitative trait locus (QTL) in each of the two populations, each accounting for 30% of the phenotypic variation. The QTL in both the SBRP and TBRP were found on chromosome 2 and contained several putative resistance genes in annotations of the Beta vulgaris and Arabidopsis thaliana genomes. This is the first report of a QTL on chromosome 2 for resistance to R. solani in B. vulgaris ssp. vulgaris and the first identification of QTL for disease resistance in table beet. The newly developed table beet reference genome and markers identified in this study may be of value for marker‐assisted selection in breeding for resistance to R. solani in both sugar beet and table beet breeding programs.

Improvement of Zn (II) and Cd (II) Biosorption by Priestia megaterium PRJNA526404 Isolated from Agricultural Waste Water.

Heavy metals are considered as dangerous pollutants even in relatively low concentrations. Biosorption is an ecofriendly technology that uses microbial biomasses for adsorbing heavy metals from wastewater on their surfaces based on physicochemical pathways. Ten agricultural wastewater samples were collected from different sites in Sohag Governorate, Egypt. One hundred and nineteen zinc and cadmium-resistant bacterial isolates were recovered from the water samples. Interestingly, the isolate R1 was selected as the most resistant to Zn2+ and Cd2+. This isolate was morphologically and biochemically characterized and identified by sequencing of 16S rRNA gene as Priestia megaterium, and then deposited in the GenBank database under the accession number PRJNA526404. Studying the effects of pH and contact time on the biosorption process revealed that the maximum biosorption was achieved within 50 min at pH 7 and 8 for Zn2+ and Cd2+, respectively, by the living and lyophelized biomass of Priestia megaterium PRJNA526404. The preliminary characterization of the main chemical groups present on the cell wall, which are responsible for heavy metal biosorption, was performed by Infrared analysis (IR). Kinetics studies revealed that data were fitted towards the models hypothesized by Langmuir and Freundlich isotherm equations. The maximum capacity values (qmax) for biosorption of zinc and cadmium reached by using living and lyophelized biomass were 196.08; 227.27 and 178.57; 212.777 mg/g, respectively, and it was indicated that lyophilization improved efficiency of the biomass to heavy metals compared to living cells. The results indicated that Priestia megaterium PRJNA526404 had good application prospect in cadmium and zinc water remediation.

Chitinase activity potential and identification of chitinolytic bacteria isolated of swimmer crab’s cell

This study aimed at investigating the chitinase enzyme activity produced by chitinolytic bacteria from the skin of blue swimmer crab (Portunus pelagicus) and identification of the genus isolate. This study consists of two stages: firstly, the qualitative and quantitative activity of the chitinase enzyme; and secondly, biochemical identification of the bacteria. The quantitative chitinase enzyme activity is measured using the UV-Vis spectrophotometer UV-Vis at the wavelength at 660 nm. The chitinase enzyme is obtained from the isolation of chitinolytic bacteria cultured within a media to grow solid chitin, which contains colloidal chitin substrate as chitinase inductor at the temperature of 30°C. The highest chitinolytic activity is obtained from the 24 h supernatant culture, with a value of enzyme activity at 0.149 U/mL. Macroscopic and microscopic identification showed that the chitinolytic bacteria isolate R1, whereas the biochemical cell shows the characteristics of the genus Pseudomonas. Keywords: biodegradable, chitinase, spectrophotometer, Portunus pelagicus, Pseudomonas DOI: 10.25165/j.ijabe.20211403.5273 Citation: Sulistijowati R, Sudin, Harmain R M. Chitinase activity potential and identification of chitinolytic bacteria isolated of swimmer crab’s cell. Int J Agric & Biol Eng, 2021; 14(3): 228–231.

Effect of symbiotic association of rhizobia and endomycorrhizae from Moroccan arid littoral dunes on Acacia cyanophylla tolerance to drought

Hatimi A, Tahrouch S, Bouizgarne B. 2018. Effect of symbiotic association of rhizobia and endomycorrhizae from Moroccan arid littoral dunes on Acacia cyanophylla tolerance to drought. Asian J For 2: 39-45. The research on behavior of A. cyanophylla Lindl plants associated with a symbiotic indigenous endomycorrhizal fungi M, and three rhizobia isolates: two low growing isolate R1 (Bradyrhizobium sp. RCM6), and R2 (Bradyrhizobium sp. RLC3) and a fast-growing isolates R3 (Rhizobium sp. S21), originated from coastal dunes of the Souss-Massa region in drought stress conditions, was investigated in greenhouse. Results have clearly shown that the growth and nutrition of seedlings of A. cyanophylla were drastically affected after two months in drought stress conditions. However, inoculation of the symbiotic microorganisms either alone (treatments M, RMC6, R2 or R3) or as inoculums consisting of combination of the rhizobia with the endomycorrhiza (treatments MR1, MR2 or MR3) resulted in enhanced tolerance of A. cyanophylla seedlings to drought stress. At 100% of field capacity (fc), all treatments showed a significant improvement of plant growth compared to non-inoculated plants in stress conditions. In addition, we have shown that Bradyrhizobium RCM6 (R1) holds a high efficiency to improve the growth and nutrition of the host plant. Indeed, higher number of nodules/plant and higher amount of total nitrogen were recorded in the seedlings inoculated with Bradyrhizobium sp. RCM6 in comparison with plants inoculated with the two other rhizobia Bradyrhizobium sp. RLC3 (R2) and Rhizobium sp. S21 (R3), and control plants. Dual inoculation with each of the three rhizobia and the endomycorrhizal complex (M) led to higher water content (W.C) and relative water content (RWC) and a significant increase in Phosphorus content of the aerial part. While positive effects were recorded for Phosphorus, no such effects were recorded for nitrogen. However, the overall results showed the importance of the use of microorganisms in the dune coastal environment particularly adequate tripartite association: rhizobia Endomycorrhizes-A. cyanophylla in enhancing tolerance to drought stress.

Production and partial characterization of biosurfactant produced by Streptomyces sp. R1.

The present study focused on developing a wild-type actinomycete isolate as a model for a non-pathogenic filamentous producer of biosurfactants. A total of 33 actinomycetes isolates were screened and their extracellular biosurfactants production was evaluated using olive oil as the main substrate. Out of 33 isolates, 32 showed positive results in the oil spreading technique (OST). All isolates showed good emulsification activity (E24) ranging from 84.1 to 95.8%. Based on OST and E24 values, isolate R1 was selected for further investigation in biosurfactant production in an agitated submerged fermentation. Phenotypic and genotypic analyses tentatively identified isolate R1 as a member of the Streptomyces genus. A submerged cultivation of Streptomyces sp. R1 was carried out in a 3-L stirred-tank bioreactor. The influence of impeller tip speed on volumetric oxygen transfer coefficient (k L a), growth, cell morphology and biosurfactant production was observed. It was found that the maximum biosurfactant production, indicated by the lowest surface tension measurement (40.5 ± 0.05 dynes/cm) was obtained at highest k L a value (50.94h-1) regardless of agitation speed. The partially purified biosurfactant was obtained at a concentration of 7.19gL-1, characterized as a lipopeptide biosurfactant and was found to be stable over a wide range of temperature (20-121 °C), pH (2-12) and salinity [5-20% (w/v) of NaCl].

Evaluation of factors affecting the fungal lipase production using one factor at a time approach and response surface methodology

T HE CURRENT research deals with optimization of the factors affecting lipase production under submerged culture system. The most efficient isolate R1 was identified depending on cultural and morphological characteristics together with 18S rRNA sequence as Rhizopus oryzae. Using one variable at a time, the maximum lipase activity (171.8 U/mL) was recorded in the presence of 1% fish-frying oil, mixture of peptone and yeast extract at pH 5 with 8% v/v of fungal inoculum after 4 days at 30°C. The screening of the most significant factors using Plackett-Burman design revealed that among ten variables, four, i.e. incubation temperature, inoculum size, incubation period and agitation speed, affected significantly (p-values ranged from 0.003 to 0.049) on the lipase activity. Optimization by using response surface methodology (RSM) through central composite design (CCD) resulted in the highest predicted lipase activity (216.2 U/mL) in which fermentation medium was inoculated with 8% inoculum size and incubated at 28°C under agitation speed of 150 rpm for 4 days.

Isolation of actinomycetes and optimization of process parameters for antimicrobial activity

Actinomycetes represent a ubiquitous group of microbes widely distributed in natural ecosystems around the world. They are economically and biotechnologically valuable prokaryotes able to produce wide range of bioactive secondary metabolites useful in medicines like antibiotics, anticancer drugs, immunosuppressant and enzyme inhibitors. In order to facilitate the discovery of novel bioactive compounds from microorganisms, various techniques for isolation of new actinomycetes strains have been followed. A total of eight actinomycetes were isolated from terrestrial soil by spread plate method on Starch casein agar (SCA). Based on the biochemical test and morphological identification four of them were selected and screened for their antimicrobial activity against E.coli and Staphylococcus aureus by agar well diffusion method. Two isolates R1 and R2 have shown the activity against the pathogens. Those isolates were subjected for optimization of various parameters such as carbon sources, nitrogen sources, temperature, pH and NaCl concentration. The isolates were then subjected to solvent extraction using ethyl acetate. Further, the extracts were tested against biofilm forming bacteria Pseudomonas aeruginosa strain NV2 by Micro titer plate assay (MTP) and well diffusion method.

Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn

Integrated options for the management of black root rot of strawberry caused by Rhizoctonia solani Kuhn

Efficacy of native phosphate-solubilizing rhizobia on symbiotic parameters and grain yield in fieldpea (Pisum sativum)

The native P-solubilizing rhizobial isolates R1 and R2 enhanced nodule number and dry weight, root and shoot dry weight, chlorophyll, N and P content and grain yield as compared to non P- solubilizing rhizobia. Native rhizobia R1 and R2 along with P @ 40 kg P2O5/ha were found to augment the efficiency of applied P which enhanced symbiotic parameters and significantly improved yields of fieldpea.

Locally isolated yeasts from Malaysia: identification, phylogenetic study and characterization.

Yeasts are a convenient platform for many applications. They have been widely used as the expression hosts. There is a need to have a new yeast expression system to contribute the molecular cloning demands. Eight yeast isolates were screened from various environment sources and identified through ribosomal DNA (rDNA) Internal Transcribed Spacer (ITS). Full sequence of the rDNA ITS region for each isolate was BLASTed and phylogenetic study was constructed by using MEGA4. Among the isolates, isolate WB from 'ragi' (used to ferment carbohydrates) could be identified as a new species in order Saccharomycetales according to rDNA ITS region, morphology and biochemical tests. Isolate SO (from spoiled orange), RT (rotten tomato) and RG (different type of 'ragi') were identified as Pichia sp. Isolates R1 and R2, S4 and S5 (from the surrounding of a guava tree) were identified as Issatchenkia sp. and Hanseniaspora sp., respectively. Geneticin, 50 µg/mL, was determined to be the antibiotic marker for all isolates excepted for isolates RT and SO which used 500 µg/mL and 100 µg/mL Zeocin, respectively. Intra-extracellular proteins were screened for lipolytic activity at 30°C and 70°C. Thermostable lipase activity was detected in isolates RT and R1 with 0.6 U/mg and 0.1 U/mg, respectively. In conclusion, a new yeast-vector system for isolate WB can be developed by using phleomycin or geneticin as the drugs resistance marker. Moreover, strains RT and R1 can be investigated as a novel source of a thermostable lipase.

Identification of recombinant intermediates of hepatitis B virus between genotype B and C in vitro.

OBJECTIVE To detect the recombinant intermediates of hepatitis B virus (HBV) between genotype B and C in vitro. METHODS Vector Plenti6/V5-D-topo-X was genetically modified by genotype B and C to transfect HepG2 cells. Then the HepG2 cells were amplified and sequence of the nucleic acid after the transinfection was tested and compared with RDP3Beta40 software package and bootscanning procedure in SimPlot program package. RESULTS Three recombinant intermediates of HBV between genotype B and C were identified in vitro. Genotype C in the precore region plus the core gene spanning nucleotide positions from 1740-1838 to 2443-2485 contributed to the recombination with genotype B. Isolate R1 recombinant intermediate had 2 break points at nt2170-2172 and nt2188-2189. Nucleic acid changed from CAC to TGT and from GA to AC, respectively. Isolate R2 recombinant intermediate had a break point at nt1740-1 838, and 3 bases changed in different nucleic acid sites: from A to T at nt1740, from C to T at nt1753, and from G to A at nt1838, respectively. Isolate R3 recombinant intermediate had a break point at nt2443-2483, and 4 bases changed in different nucleic acid sites: from C to T at nt2443, from A to G at nt2452, from T to C at nt2480, and from C to T at nt2483, respectively. CONCLUSION The recombinant intermediates of HBV between genotype B and C have been detected in vitro and the changes have been identified in the precore region plus the core gene in genotype B and C.

Experimental Reproduction of Transmissible Viral Proventriculitis by Infection of Chickens with a Novel Adenovirus-Like Virus (Isolate R11/3)

Transmissible viral proventriculitis (TVP) was experimentally reproduced in 2-wk-old specific-pathogen-free chickens and commercial broiler chickens by eyedrop inoculation of adenovirus-like virus (AdLV), isolate R1 1/3. No clinical signs and no weight gain depression were observed in chickens inoculated with AdLV (R11/3); however, gross and microscopic lesions characteristic of TVP were present in proventriculi of inoculated chickens. Proventriculi of AdLV (R11/3)-inoculated chickens were markedly enlarged, compared with sham-inoculated controls, by day 7 postinoculation (PI). Microscopic lesions in proventriculi of inoculated chickens were detected beginning on day 3 PI and consisted of degeneration and necrosis of glandular epithelium, ductal epithelial hyperplasia, replacement of glandular epithelium with ductal epithelium, and diffuse interstitial lymphoid infiltration; no microscopic lesions were observed in other tissues. AdLV (R11/3) antigens were detected in proventriculi by immunohistochemistry on days 3-10 PI in inoculated SPF chickens and days 3-21 PI in inoculated commercial broiler chickens; no viral antigens were detected in other tissues. AdLV (R11/3) was reisolated from proventriculi of inoculated SPF and commercial broiler chickens on days 5 and 7 PI. No virus, viral antigens, or lesions were detected in proventriculi collected from sham-inoculated chickens. These findings indicate an etiologic role for AdLV (R11/3) in TVP.

Genetic variation ofNSP1 andNSP4 genes among serotype G9 rotaviruses causing hospitalization of children in Melbourne, Australia, 1997–2002

Serotype G9 rotaviruses have emerged as one of the leading causes of gastroenteritis in children worldwide. We examined 29 representative G9 rotavirus isolates from a 6-year collection (1997-2002) and determined the level of variation in genes encoding non-structural proteins, NSP1 and NSP4. Northern hybridization analysis with a whole genome probe derived from the prototype G9 strain, F45, revealed that the NSP1 gene (gene 5) of two isolates (R1 and R14) did not exhibit significant homology. Complementary DNA probes of R1 and R14 genes 5 were used in Northern blot hybridization and indicated the presence of at least two gene 5 alleles among Melbourne G9 rotaviruses. Nucleotide sequence analysis revealed that isolates carrying the R14 gene 5 shared 94-98% sequence identities with one another, while sequence identity to R1 was 78%. Surprisingly, R1 displayed 96% nucleotide identity with the prototype serotype G1 strain, Wa. The detection of different alleles of NSP1 genes prompted us to investigate the level of variation in another non-structural protein, NSP4, a multifunctional protein and the first viral-encoded enterotoxin. Phylogenetic analysis indicated that while all isolates clustered into one group containing the Wa NSP4 allele (genotype 1), isolate R1 was most closely related to Wa. This study reveals new information about the diversity of non-structural proteins of G9 rotaviruses.

New genes for resistance to downy mildew (Peronospora parasitica) in oilseed rape (Brassica napus ssp. oleifera)

The response of cotyledons of oilseed rape (Brassica napus ssp. oleifera) accessions to infection by isolates of Peronospora parasitica under controlled conditions was assessed on a 0–7 scale (disease reaction). In interactions scored 0–3, 4–5 and 6–7, the host was considered resistant, partially resistant and susceptible, respectively. Accession RES‐26, selected from the spring oilseed rape cultivar Janetzkis, was partially resistant to isolate R1 and resistant to isolate P003 of P. parasitica, which distinguishes it from three previously described differential response groups (‘A’, ‘B’ and ‘C’) of accessions in B. napus. The resistance of RES‐26 to isolate P003 seemed to be conditioned by a single, partially dominant gene and the resistance of RES‐02, which belongs to group ‘A’ (resistant to R1 and P003), by two independent partially dominant genes. The gene for resistance to P003 in RES‐26 is either closely linked, allelic or identical to one of the two genes for resistance in RES‐02. Resistance of RES‐02 to R1 is conditioned by a single, incompletely dominant gene. The genes for resistance to isolates R1 and P003 in RES‐02 are either closely linked, allelic or identical. The cotyledonary leaves of each seedling responded independently when inoculated simultaneously each with a different isolate of the pathogen.

Seroanalysis of Tyzzer's disease in horses: implications that multiple strains can infect Equidae

A monoclonal antibody based competitive inhibition assay was used to detect antibodies in horse sera to purified flagellar antigens from distinct Clostridium piliforme isolates. Sequential absorption of hyperimmune rat serum to C. piliforme isolate E (horse-origin isolate), a positive C. piliforme-immune horse serum, and other suspected immune horse sera with unrelated bacteria or C. piliforme isolates E or isolate R1 (rat-origin isolate) alone demonstrated the specificity of this assay for C. piliforme. This specificity was associated with the inhibition of monoclonal antibody binding to C. piliforme flagella, rather than to C. piliforme somatic antigens, by horse immunoglobulins partially purified from serum. Thirty seven of 162 horse sera possessed large amounts of antibody to the flagella of C. piliforme isolate E and 23 of the 162 had large amounts of antibody to the flagella of C. piliforme isolate R1; 9 of the sera possessed large amounts of antibody to both flagellar antigens. Absorption of these sera with isolate E or R1 demonstrated that antibody reactivity to the 2 C. piliforme isolates was isolate-specific and not due to antibody cross-reactive with both isolates. These results suggest that infection of horses with C. piliforme may be relatively common; and that they are susceptible to at least 2 distinct strains.

Survival of anaerobic fungi in feces, in saliva, and in pure culture

Survival of anaerobic fungi in feces, in saliva, and in pure culture

The fermentative characteristics of anaerobic rumen fungi

The fermentative characteristics of anaerobic rumen fungi