Li, Ling; Eom, Hyun-Ju; Park, Jung-Mi; Seo, Eunyoung; Ahn, Ji Eun; Kim, Tae-Jip; Kim, Jeong Hwan; Han, Nam Soo
Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 is a lactic acid bacterium that converts pyruvate mainly to d-(-)-lactic acid by using d-(-)-lactate dehydrogenase (ldhD). The aim of this study was to identify the gene responsible for d-lactic acid formation in this organism and to characterize the enzyme to facilitate the production of optically pure d-lactic acid. A genomic analysis of L. mesenteroides ATCC 8293 revealed that 7 genes encode lactate-related dehydrogenase. According to transcriptomic, proteomic, and phylogenetic analyses, LEUM_1756 was the major gene responsible for the production of d-lactic acid. The LEUM_1756 gene, of 996bp and encoding 332 amino acids (36.5kDa), was cloned and overexpressed in Escherichia coli BL21(DE3) Star from an inducible pET-21a(+) vector. The enzyme was purified by Ni-NTA column chromatography and showed a specific activity of 4450U/mg, significantly higher than those of other previously reported ldhDs. The gel permeation chromatography analysis showed that the purified enzyme exists as tetramers in solution and this was the first report among lactic acid bacteria. The pH and temperature optima were pH 8.0 and 30°C, respectively, for the pyruvate reduction reaction, and pH 11.0 and 20°C, respectively, for the lactate oxidation reaction. The K(m) kinetic parameters for pyruvate and lactate were 0.58mM and 260mM, respectively. In addition, the k(cat) values for pyruvate and lactate were 2900s(-1) and 2280s(-1), respectively. The enzyme was not inhibited by Ca(2+), Co(2+), Cu(2+), Mg(2+), Mn(2+), Na(+), or urea, but was inhibited by 1mM Zn(2+) and 1mM SDS.
Kot, W. P.; Hansen, L. H.; Sørensen, S. J.; Broadbent, J. R.; Vogensen, F. K.; Ardö, Y.
Leuconostoc is the main group of heterofermentative bacteria found in mesophilic dairy starters. They grow in close symbiosis with the Lactococcus population and are able to degrade citrate. Here we present a draft genome sequence of Leuconostoc mesenteroides subsp. cremoris strain T26. PMID:24903867
Diana, Castro-Rodríguez; Humberto, Hernández-Sánchez; Jorge, Yáñez Fernández
Four lactic acid bacteria, Leuconostoc mesenteroides subsp. mesenteroides, were isolated from aguamiel the sap obtained from Agave salmiana from México and identified by 16S rRNA gene sequence analysis. The probiotic potential of these strains was evaluated and compared with a commercial probiotic (Lactobacillus plantarum 299v) from human origin. All the strains survived the in vitro gastrointestinal simulation conditions: the stomach simulation (3 h, pH 2, 37 °C) and the intestinal simulation (4 h, bile salts 0.5%, 37 °C). All the strains showed a strong hydrophilic character with n-hexadecane and chloroform assays, and all the strains showed a mucin adhesion rate similar to that of L. plantarum 299v. The strains of L. mesenteroides subsp. mesenteroides exhibited similar antimicrobial activity against some pathogens in comparison with L. plantarum 299v. Some antibiotics inhibited the growth of the strains. L. mesenteroides subsp. mesenteroides exhibited in vitro probiotic potential, and it could be better characterized through future in vivo tests.
Mtshali, Phillip Senzo; Divol, Benoit; du Toit, Maret
Fifteen isolates of lactic acid bacteria originating from South African grape and wine samples were identified as Leuconostoc mesenteroides subsp. mesenteroides through the taxonomic analysis of their 16S rDNA gene sequences. These isolates were further tested for the presence of genes coding for enzymes of oenological relevance using PCR detection technique. A type strain of Leuc. mesenteroides (NCDO 529(T)) was also incorporated for comparative analysis. From the PCR detection results, the estA, prtP, alsD, alsS, metK, metC and metB genes were present in all the strains tested. The bgl and gshR genes encoding β-glucosidase and glutathione reductase, respectively, were not detected in some strains. On the other hand, none of the tested strains possessed the genes encoding phenolic acid decarboxylase (padA), citrate permease (citP), citrate lyase (citD, citE and citF) and arginine deiminase pathway enzymes (arcA, arcB and arcC). The verification of PCR-generated fragments was performed by sequencing. GenBank database was used to search for homologous DNA sequences. Neighbour-joining trees based on nucleotide sequences of alsS, estA, metK and mleA genes were also constructed in order to study the phylogenetic relationship between Leuc. mesenteroides strains and closely related species. The phylogenetic analyses revealed that there are genetic heterogeneities between strains of Leuc. mesenteroides species. In conclusion, this study has improved our knowledge on the genetics of oenological strains of Leuc. mesenteroides and their genetic potential to contribute to certain wine aroma compounds.
Daba, H; Pandian, S; Gosselin, J F; Simard, R E; Huang, J; Lacroix, C
Leuconostoc mesenteroides UL5 was found to produce a bacteriocin, referred as mesenterocin 5, active against Listeria monocytogenes strains but with no effect on several useful lactic acid bacteria. The antimicrobial substance is a protein, since its activity was completely destroyed following protease (pronase) treatment. However, it was relatively heat stable (100 degrees C for 30 min) and partially denaturated by chloroform. The inhibitory effect of the bacteriocin on sensitive bacterial strains was determined by a critical-dilution micromethod. Mutants of L. mesenteroides UL5 which had lost the capacity to produce the bacteriocin were obtained. The mutant strain was stable and phenotypically identical to parental cells and remained resistant to the bacteriocin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis was used to detect bacteriocin activity corresponding to an apparent molecular mass of about 4.5 kDa. Images PMID:1785922
DeMoss, R. D.; Moser, K.
A partially purified enzyme (120-fold) from Leuconostoc mesenteroides catalyzed the reversible N-acetylation of d-glucosamine-6-phosphate. Coenzyme A was not required and inhibited the reaction rate. Neither d-glucosamine nor N-acetyl-d-glucosamine served as a substrate for the reversible reaction. The enzyme preparation retained 50% of its original activity after 5 min at 100 C. The Km for acetate was 7.7 × 10−2m in the presence of 2 × 10−2md-glucosamine-6-phosphate. The Km for d-glucosamine-6-phosphate was 5.0 × 10−3m in the presence of 0.64 m acetate. The product of the reaction was characterized by comparison with N-acetyl-d-glucosamine-6-phosphate prepared by enzymatic phosphorylation of N-acetyl-d-glusamine. The characterization tests were: chromatographic migration, acid hydrolysis, enzymatic dephosphorylation, sodium borohydride reduction, and periodate oxidation. The equilibrium constant for the reaction was about 7.5 m for the expression K = (d-glucosamine-6-phosphate)(acetate)/N-acetyl-d-glucosamine-6-phosphate. The standard free energy of the reaction was approximately 1,200 cal per mole. PMID:5781575
Kim, Yu Jin; Eom, Hyun-Ju; Seo, Eun-Young; Lee, Dong Yup; Kim, Jeong Hwan; Han, Nam Soo
Leuconostoc mesenteroides is a heterofermentative Grampositive bacterium that plays key roles in fermentation of foods such as kimchi, sauerkraut, and milk, leading to the production of various organic acids and aromatic compounds. To study the microbiological and genomic characteristics of L. mesenteroides, we have developed a new chemically defined minimal medium by using the single omission technique. During the exponential cell growth, this species required glutamine, methionine, valine, and nicotinic acid as essential nutrients and 8 amino acids (arginine, cysteine, histidine, leucine, phenylalanine, proline, threonine, and tryptophan), 5 vitamins (ascorbic acid, folic acid, inosine, calcium panthothenate, and thiamine), and others (manganese, magnesium, adenine, uracil, and Tween 80) as supplemental nutrients. This medium is useful to study the metabolic characteristics of L. mesenteroides and to explain its role in food fermentation.
Han, Jin; Hang, Feng; Guo, Benheng; Liu, Zhenmin; You, Chunpin; Wu, Zhengjun
The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches.
Campedelli, Ilenia; Flórez, Ana Belén; Salvetti, Elisa; Delgado, Susana; Orrù, Luigi; Cattivelli, Luigi; Alegría, Ángel; Felis, Giovanna E.; Mayo, Baltasar
Leuconostoc mesenteroides is a lactic acid bacterium (LAB) commonly associated with fermented foods. Here, we report the genome sequence of three selected dairy strains, showing atypical antibiotic resistances (AR). Genome analysis provided a better understanding of the genetic bases of AR in Leuconostoc and its potential transferability among foodborne bacteria. PMID:26358600
Native alternan is a high molar mass homopolymer of D-glucose produced by some strains of the bacterium Lueconostoc mesenteroides. It consists of glucose units that alternate their linkages between alpha-(1-6) and alpha-(1-3) between glucosyl units. The glucose units contained in the polysaccharid...
Benmechernene, Zineb; Chentouf, Hanane Fatma; Yahia, Bellil; Fatima, Ghazi; Quintela-Baluja, Marcos; Calo-Mata, Pilar; Barros-Velázquez, Jorge
Two strains (B7 and Z8) of the Leuconostoc mesenteroides subspecies mesenteroides that were isolated from Algerian camel milk from an initial pool of 13 strains and demonstrated a high ability to inhibit the growth of Listeria spp. were selected and characterised at the phenotypic and genotypic levels. Probiotic profiling and inhibition spectra against food borne pathogens in mixed cultures were also investigated. The bacteriocin produced by L. mesenteroides strain B7 was identified as leucocin B by specific PCR. In vitro studies demonstrated that both Leuconostoc mesenteroides strains exhibited a marked probiotic profile, showing high survival at low pH (2-3 and 4) in the presence of 0.5%, 1%, and 2% of bile salts and at pH 3 in the presence of 3 mg/mL pepsin. Susceptibility testing against antimicrobial agents was also performed for both strains. When tested in a mixed culture with Listeria innocua, Listeria ivanovii, or Staphylococcus aureus, strain B7 reduced the numbers of these species by 1.87, 1.78, and 1.38 log units, respectively. Consequently, these two strains were found to possess good probiotic properties in vitro and a high capacity for Listeria spp. inhibition in mixed cultures. Therefore, these strains have a favourable technological aptitude and a potential application as novel probiotic starters. PMID:24392451
Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. Mutants of this strain are available that are deficient in the production of alternan, dextran, or both. Our recent work demonstrated that biofilms from all strains con...
Leuconostoc mesenteroides strain NRRL B-1355 produces the soluble exopolysaccharides alternan and dextran in planktonic cultures. A set of mutants of this strain are available that are deficient in the production of alternan, dextran, or both. Another mutant of NRRL B-1355, strain R1510, produces ...
Lee, Jin-Ha; Moon, Young-Hwan; Kim, Nahyun; Kim, Young-Min; Kang, Hee-Kyoung; Jung, Ji-Yeon; Abada, Emad; Kang, Seong-Soo; Kim, Doman
The gene encoding sucrose phosphorylase (742sp) in Leuconostoc mesenteroides NRRL B-742 was cloned and expressed in Escherichia coli. The nucleotide sequence of the transformed 742sp comprised an ORF of 1,458 bp giving a protein with calculated molecular mass of 55.3 kDa. 742SPase contains a C-terminal amino acid sequence that is significantly different from those of other Leu. mesenteroides SPases. The purified 742SPase had a specific activity of 1.8 U/mg with a K (m) of 3 mM with sucrose as a substrate; optimum activity was at 37 degrees C and pH 6.7. The purified 742SPase transferred the glucosyl moiety of sucrose to cytosine monophosphate (CMP).
Xu, Yan; Coda, Rossana; Shi, Qiao; Tuomainen, Päivi; Katina, Kati; Tenkanen, Maija
Consumption of legumes is highly recommended due to their beneficial properties. Thus, there is a great interest in developing new legume-based products with good texture. In situ produced microbial exopolysaccharides (EPS) are regarded as efficient texture modifiers in the food industry. In this study, soybean and fava bean flours with different levels of added sucrose were fermented by Leuconostoc mesenteroides DSM 20343. After fermentation, a significant increase in viscosity was observed. Sugars, glucans, fructans, mannitol, lactic acid, and acetic acid were quantified to follow the EPS and metabolite production. By treating the fermented doughs selectively with dextranase or levanase, the major role of glucans in viscosity improvement was confirmed. The roles of microbial fructansucrase and endogenous α-galactosidase in degradation of raffinose family oligosaccharides (RFO) were also investigated. This study shows the potential of Ln. mesenteroides DSM 20343 in tailoring viscosity and RFO profiles in soybean and fava bean flours.
Muhialdin, Belal J; Hassan, Zaiton; Abu Bakar, Fatimah; Algboory, Hussein L; Saari, Nazamid
The ability of Leuconostoc mesenteroides DU15 to produce antifungal peptides that inhibit growth of Aspergillus niger was evaluated under optimum growth conditions of 30 °C for 48 h. The cell-free supernatant showed inhibitory activity against A. niger. Five novel peptides were isolated with the sequences GPFPL, YVPLF, LLHGVPLP, GPFPLEMTLGPT, and TVYPFPGPL as identified by de novo sequencing using PEAKS 6 software. Peptide LLHGVPLP was the only positively charged (cationic peptides) and peptide GPFPLEMTLGPT negatively charged (anionic), whereas the rest are neutral. The identified peptides had high hydrophobicity ratio and low molecular weights with amino acids sequences ranging from 5 to 12 residues. The mode of action of these peptides is observed under the scanning electron microscope and is due to cell lysis of fungi. This work reveals the potential of peptides from L. mesenteroides DU15 as natural antifungal preservatives in inhibiting the growth of A. niger that is implicated to the spoilage during storage.
Pujato, Silvina A; Mercanti, Diego J; Guglielmotti, Daniela M; Rousseau, Geneviève M; Moineau, Sylvain; Reinheimer, Jorge A; Quiberoni, Andrea del L
Phages infecting Leuconostoc mesenteroides strains can be overlooked during milk fermentation because they do not slowdown the acidification process. However, they can negatively impact the flavor profile of the final product. Yet, the information about these phages is still scarce. In this work, we investigated diverse factors influencing the adsorption of seven virulent Ln. mesenteroides phages, isolated from blue cheese manufacture in Argentina, to their host cells. The addition of calcium ions was generally necessary to observe complete cell lysis and plaque formation for four of the seven phages, but adsorption was very high even in the absence of this cation for all phages. The temperature barely influenced the adsorption process as it was high within the temperature range tested (0 to 50 °C). Moreover, the kinetics of adsorption were similar on viable and non-viable cells, revealing that phage adsorption does not depend on physiological state of the bacterial cells. The adsorption rates were also high at pH values from 4 to 9 for all Ln. mesenteroides phages. We also analyzed the complete genome sequences of two of these phages. Complete nucleotide analysis of phages Ln-8 and Ln-9 showed dsDNA genomes with sizes of 28.5 and 28.9 kb, and the presence of 45 and 48 open reading frames (ORFs), respectively. These genomes were highly similar to those of previously characterized Φ1-A4 (USA, sauerkraut, fermentation) and ΦLN25 (England, whey), both virulent Ln. mesenteroides phages. A detailed understanding of these phages will lead to better control strategies.
Johanningsmeier, Suzanne; McFeeters, Roger F; Fleming, Henry P; Thompson, Roger L
Sauerkraut fermentations rely upon selection of naturally occurring lactic acid bacteria by addition of 2.0% to 2.25% granulated sodium chloride (NaCl) to shredded cabbage. Excess brine generated is a waste product with high levels of organic material (BOD) and nonbiodegradable NaCl. The objective was to determine whether addition of Leuconostoc mesenteroides starter culture to reduced-salt cabbage fermentations would yield sauerkraut with reproducible and acceptable chemical composition and sensory qualities. Shredded cabbage was salted with 0.5%, 1.0%, or 2.0% NaCl (wt/wt) at 2 starter culture levels, none or L. mesenteroides strain LA 81, ATCC 8293 (10(6) CFU/g). Fermentation products were quantified by high-performance liquid chromatography, and pH was measured during the initial stages of fermentation and after 10 mo storage at 18 degrees C. A trained descriptive sensory panel used category scales to rate the flavor and texture of selected sauerkrauts. A modified Kramer shear test was used to measure firmness. Cabbage fermented with L. mesenteroides consistently resulted in sauerkraut with firm texture and reduced off-flavors across all salt levels (P < 0.05). Conversely, sauerkraut quality was highly variable, with softening and off-flavors occurring as salt concentrations were decreased in natural fermentations (P < 0.05). Fermentations were rapid, with a more uniform decline in pH when starter culture was added. L. mesenteroides addition to cabbage fermentations ensured that texture and flavor quality were retained, while allowing 50% NaCl reduction. Application of this technology to commercial sauerkraut production could improve the uniformity of fermentations and substantially reduce generation of nonbiodegradable chloride waste.
Jung, Ji Young; Lee, Se Hee; Lee, Hyo Jung; Seo, Hye-Young; Park, Wan-Soo; Jeon, Che Ok
Kimchi fermentation usually relies upon the growth of naturally-occurring various heterofermentative lactic acid bacteria (LAB). This sometimes makes it difficult to produce kimchi with uniform quality. The use of Leuconostoc mesenteroides as a starter has been considered to produce commercial fermented kimchi with uniform and good quality in Korea. In this study, a combination of a barcoded pyrosequencing strategy and a (1)H NMR technique was used to investigate the effects of Leu. mesenteroides strain B1 as a starter culture for kimchi fermentation. Baechu (Chinese cabbage) and Chonggak (radish) kimchi with and without Leu. mesenteroides inoculation were prepared, respectively and their characteristics that included pH, cell number, bacterial community, and metabolites were monitored periodically for 40 days. Barcoded pyrosequencing analysis showed that the numbers of bacterial operational taxonomic units (OTU) in starter kimchi decreased more quickly than that in non-starter kimchi. Members of the genera Leuconostoc, Lactobacillus, and Weissella were dominant LAB regardless of the kimchi type or starter inoculation. Among the three genera, Leuconostoc was the most abundant, followed by Lactobacillus and Weissella. The use of Leu. mesenteroides as a starter increased the Leuconostoc proportions and decreased the Lactobacillus proportions in both type of kimchi during kimchi fermentation. However, interestingly, the use of the kimchi starter more highly maintained the Weissella proportions of starter kimchi compared to that in the non-starter kimchi until fermentation was complete. Metabolite analysis using the (1)H NMR technique showed that both Baechu and Chonggak kimchi with the starter culture began to consume free sugars earlier and produced a little greater amounts of lactic and acetic acids and mannitol. Metabolite analysis demonstrated that kimchi fermentation using Leu. mesenteroides as a starter was completed earlier with more production of kimchi
Miljković, Miona G; Davidović, Slađana Z; Carević, Milica B; Veljović, Đorđe N; Mladenović, Dragana D; Rajilić-Stojanović, Mirjana D; Dimitrijević-Branković, Suzana I
Sugar beet pulp (SBP) and molasses, as an agro industrial waste material, are produced in large amounts annually. Thus, a major challenge nowadays is to develop procedures that could increase the value of the generated waste. In this study, SBP as a support for cell immobilization and molasses as a source of nutrients were used for a dextransucrase (DS) production by Leuconostoc mesenteroides T3. The influence of SBP in native form (SBP-N) and after treatment with NaOH (SBP-NaOH) on DS production was investigated. The optimal medium composition for the maximum DS production was determined by varying the concentration of molasses, SBP, and sucrose. The maximum DS yield of 2.02 U/ml was obtained in the medium with 2.5 % of molasses, 2.5 % SBP-NaOH, and 4 % of sucrose concentration. Scanning electron microscopy (SEM) showed immobilization of Lc. mesenteroides T3 cells onto SBP-NaOH. According to the obtained results, the production of DS on molasses could be improved by using NaOH-treated SBP as a carrier for whole-cell immobilization. Our study reveals the basis for the development of process for DS production with additional reduction of expenses by using waste materials for obtaining the valuable biotechnological product.
Kondo, Sayo; Takahashi, Toshinari; Yoshida, Kazutoshi; Mizoguchi, Haruhiko
We investigated the inhibitory effects of the autolysate of Leuconostoc mesenteroides, a lactic acid bacterium isolated from sake mash, on melanogenesis in B16F0 murine melanoma cells and a human skin model. The autolysate: induced a decrease in melanin content in B16F0 murine melanoma cells and a 17%, 36%, 41% and 58% decrease in the human skin model by the application of 0.125, 1.25, 6.25, and 12.5 mg/tissue in total; decreased tyrosinase activity to 71%, 46% and 29% of control in B16F0 cells with 0.1, 0.2 and 0.4 mg/ml-medium respectively, but did not inhibit tyrosinase activity under cell-free conditions; decreased amount of tyrosinase in a dose-dependent manner from 74% with 0.1 mg/ml to 33% with 0.4 mg/ml; and decreased amount of tyrosinase mRNA to 80-90% with 0.2-0.4 mg/ml-medium. As the decrease in tyrosinase mRNA levels could not fully account for the reduction in protein, we suggest that the autolysate had post-transcriptional effects rather than transcription inhibition. Our results indicate that the autolysate of L. mesenteroides has potential therapeutic use as an effective anti-melanogenic agent.
We have cloned a glucansucrase from the type strain of Leuconostoc mesenteroides (NRRL B-1118; ATCC 8293) and successfully expressed the enzyme in Escherichia coli. The recombinant processed enzyme has a putative sequence identical to the predicted secreted native enzyme (1,473 amino acids; 161,468...
The type strain of the lactic acid bacterium Leuconostoc mesenteroides produces a water-insoluble glucan from sucrose via an extracellular glucansucrase. Substitution of an amino acid that is coupled with the +2 subsite adjacent to the transition stabilizer of this glucansucrase, results in signific...
Handwerger, S; Pucci, M J; Volk, K J; Liu, J; Lee, M S
The emergence of acquired high-level resistance among Enterococcus species has renewed interest in mechanisms of resistance to glycopeptide antibiotics in gram-positive bacteria. In Enterococcus faecalis and Enterococcus faecium, resistance is encoded by the van gene cluster and is due to the production of a peptidoglycan precursor terminating in D-alanyl-D-lactate, to which vancomycin does not bind. Most Leuconostoc and many Lactobacillus species are intrinsically resistant to high levels of glycopeptide antibiotics, but the mechanism of resistance has not been elucidated. To determine whether the mechanisms of resistance are similar in intrinsically resistant bacteria, cytoplasmic peptidoglycan precursors were isolated from Leuconostoc mesenteroides and Lactobacillus casei and analyzed by mass spectrometry, revealing structures consistent with UDP-N-acetylmuramyl-L-Ala-D-Glu-L-Lys-(L-Ala)-D-Ala-D-lactate and UDP-N-acetylmuramyl-L-Ala-D-Glu-L-Lys-D-Ala-D-lactate, respectively. PMID:8282706
Ziegler, E; Dahmen, J
Mannose-2-14C has been fermented by Leuconostoc mesenteroides, CO2 ethanol and D-lactic acid were formed in a molar ratio of 1:1:1. A small amount of acetic acid was found as by-product. It could easily be isolated from the main products of the fermentation and it did not disturb further degradation procedures. The methyl-C-atom of ethanol, which was derived from C-2 of the mannose, had nearly the same specific radioactivity as mannose-2-14C. All other C-atoms of the degradation products were only very slightly labeled. Their content of radioactivity was in any case lower than 3% of the specific radioactivity of the degraded mannose. This procedure is applicable for the degradation of 14C-labeled mannose.
Finkenstadt, Victoria L; Côté, Gregory L; Willett, J L
Corrosion of metals is a serious and challenging problem faced worldwide by industry. Purified Leuconostoc mesenteroides exopolysaccharide (EPS) coatings, cast from aqueous solution, inhibited the corrosion of low-carbon steel as determined by electrochemical impedance spectroscopy (EIS). There were two different corrosion behaviors exhibited when EPS films from different strains were cast onto the steel. One EPS coating reacted immediately with the steel substrate to form an iron (III) oxide layer ("rust") during the drying process while another did not. The samples that did not flash corrode had higher corrosion inhibition and formed an iron (II) passivation layer during EIS testing that persisted after the cells were disassembled. Corrosion inhibition was strain-specific as polysaccharides with similar structure did not have the same corrosion potential.
Wolf, B F; Fogler, H S
Bacterial profile modification is an important enhanced oil recovery technique used to direct injected water into a reservoir's low permeability zone containing trapped crude oil. During water flooding, the use of bacteria to plug the high permeability water zone and divert flow into the oil-bearing low-permeability zone will have a significant economic impact. However, during the field implementation of bacterial profile modification, the rapid growth of bacteria near the injection well bore may hinder the subsequent injection of growth media so that profile modification of the reservoir occurs only in the immediate vicinity of the well bore. By slowing the growth rate and prolonging the lag phase, the onset of pore-space plugging may be delayed and the biologically active zone extended deep into the reservoir. High substrate loading, high pH values, and the addition of the growth inhibitors sodium dodecylsulfate and sodium benzoate have been used in combination to alter the growth characteristics of Leuconostoc mesenteroides NRRL-B523 grown in batch conditions. The highest sucrose concentration used in these studies, 500 g/L, produced lag times 12-fold greater than the slowest lag times achieved at low sucrose concentrations. When L. mesenteroides was grown in media containing 500 g/L sucrose, an alkaline pH value threshold was found above which bacteria did not grow. At this threshold pH value of 8.1, an average lag time of 200 h was observed. Increasing the concentration of sodium benzoate had no effect on lag time, but reduced the growth rate until the threshold concentration of 0.6%, above which bacteria did not grow. Last, it was found that a solution of 0.075 mM sodium dodecylsulfate in media containing 15 g/L sucrose completely inhibited bacterial growth.
Riveros-Mckay, Fernando; Campos, Itzia; Giles-Gómez, Martha; Bolívar, Francisco
Leuconostoc mesenteroides P45 was isolated from the traditional Mexican pulque beverage. We report its draft genome sequence, assembled in 6 contigs consisting of 1,874,188 bp and no plasmids. Genome annotation predicted a total of 1,800 genes, 1,687 coding sequences, 52 pseudogenes, 9 rRNAs, 51 tRNAs, 1 noncoding RNA, and 44 frameshifted genes. PMID:25377708
Riveros-Mckay, Fernando; Campos, Itzia; Giles-Gómez, Martha; Bolívar, Francisco; Escalante, Adelfo
Leuconostoc mesenteroides P45 was isolated from the traditional Mexican pulque beverage. We report its draft genome sequence, assembled in 6 contigs consisting of 1,874,188 bp and no plasmids. Genome annotation predicted a total of 1,800 genes, 1,687 coding sequences, 52 pseudogenes, 9 rRNAs, 51 tRNAs, 1 noncoding RNA, and 44 frameshifted genes.
Yan, Minghui; Han, Jin; Xu, Xiaofen; Liu, Lianliang; Gao, Caixia; Zheng, Huajun; Chen, Yunxia; Tao, Yimin; Zhou, Hu; Li, Yunfei; Wu, Zhengjun
Leuconostoc mesenteroides is a member of lactic acid bacteria (LAB) with wide applications in the food and medical industries. Species in the genus Leuconostoc are catalase-negative and generally regarded as facultative anaerobic or aerotolerant organisms. Despite their extensive use in industry, certain issues concerning the aerobic life of L. mesenteroides, e.g., the mechanism involved in the tolerance to oxygen, remain to be addressed. In this manuscript, a survival strategy employed by L. mesenteroides BD3749 in response to oxidative stress was elucidated. BD3749 cells cultivated in medium with sucrose available synthesized large amounts of exopolysaccharides, mostly consisting of insoluble EPS. When BD3749 cells were challenged with oxidative stress, the amount of insoluble EPS was greatly enhanced. The synthesized EPSs reduced the accumulation of reactive oxygen species (ROS) in bacterial cells and improved their survival during chronic oxidative stress. Another study showed that Gsy, a novel glucansucrase in the GH70 family that is induced by sucrose and up-regulated following exposure to oxygen, was responsible for the synthesis of insoluble EPS. Gsy was subsequently demonstrated to play pivotal roles in the formation of aggregates to alleviate the detrimental effects on BD3749 cells exerted by oxygen. PMID:27924943
Kim, Dong-Shik; Thomas, Steven; Fogler, H. Scott
Laboratory experiments have definitively shown that exopolymer-producing bacteria have the potential to modify the flow of fluids in oil reservoirs to enhance oil production. Once injected into the reservoir, they will be subjected to a wide range of pH values and to starvation resulting from nutrient depletion. For successful field implementation it is necessary to have a fundamental understanding of these effects on the viability of bacteria. This paper addresses the effects of pH and trace minerals on cell viability of Leuconostoc mesenteroides during carbon source depletion. Two different carbon sources were used to grow cells before transferring the cells to starvation conditions: sucrose and a combination of glucose and fructose. These substrates were chosen because L. mesenteroides produces a significant amount of water-insoluble exopolymers (dextran) under sucrose-fed conditions, which may enhance cell survival under harsh conditions. The effects of dextran on the cell viability were tested at different pH values with and without trace minerals. The rate of cell death followed an exponential-decay law for different values of the solution pH. The optimal solution pH for survival was pH 5, whereas cells died rapidly at pH 3 and below and at pH 13 and above. The sucrose-fed cells showed a greater viability than cells fed glucose and fructose for all pH ranges tested. The results indicated that water-insoluble exopolymers help cells survive for longer periods of time under starvation conditions. The effects of trace minerals on cell culturability were tested at two pH values, 4.5 and 7. For both cases, cells showed a greater culturability (smaller decay rate constant) in the presence of trace minerals than without trace minerals. It was also found that the effects of trace minerals on cell culturability were greater for glucose-fructose-fed cells than for sucrose-fed cells. The Michaelis pH function theory was used for comparing the relationships between the
Kim, D S; Thomas, S; Fogler, H S
Laboratory experiments have definitively shown that exopolymer-producing bacteria have the potential to modify the flow of fluids in oil reservoirs to enhance oil production. Once injected into the reservoir, they will be subjected to a wide range of pH values and to starvation resulting from nutrient depletion. For successful field implementation it is necessary to have a fundamental understanding of these effects on the viability of bacteria. This paper addresses the effects of pH and trace minerals on cell viability of Leuconostoc mesenteroides during carbon source depletion. Two different carbon sources were used to grow cells before transferring the cells to starvation conditions: sucrose and a combination of glucose and fructose. These substrates were chosen because L. mesenteroides produces a significant amount of water-insoluble exopolymers (dextran) under sucrose-fed conditions, which may enhance cell survival under harsh conditions. The effects of dextran on the cell viability were tested at different pH values with and without trace minerals. The rate of cell death followed an exponential-decay law for different values of the solution pH. The optimal solution pH for survival was pH 5, whereas cells died rapidly at pH 3 and below and at pH 13 and above. The sucrose-fed cells showed a greater viability than cells fed glucose and fructose for all pH ranges tested. The results indicated that water-insoluble exopolymers help cells survive for longer periods of time under starvation conditions. The effects of trace minerals on cell culturability were tested at two pH values, 4.5 and 7. For both cases, cells showed a greater culturability (smaller decay rate constant) in the presence of trace minerals than without trace minerals. It was also found that the effects of trace minerals on cell culturability were greater for glucose-fructose-fed cells than for sucrose-fed cells. The Michaelis pH function theory was used for comparing the relationships between the
Barea-Alvarez, Montserrat; Benito, Maria Teresa; Olano, Agustín; Jimeno, Maria Luisa; Moreno, F Javier
This paper reports the efficient enzymatic synthesis of a homologous series of isomaltulose-derived oligosaccharides with degrees of polymerization ranging from 3 to 9 through the transglucosylation reaction using a dextransucrase from Leuconostoc mesenteroides B-512F. The total oligosaccharide yield obtained under optimal conditions was 41-42% (in weight with respect to the initial amount of isomaltulose) after 24-48 h of reaction. Nuclear magnetic resonance (NMR) structural characterization indicated that dextransucrase specifically transferred glucose moieties of sucrose to the C-6 of the nonreducing glucose residue of isomaltulose. Likewise, monitoring the progression of the content of each individual oligosaccharide indicated that oligosaccharide acceptor products of low molecular weight acted in turn as acceptors for further transglucosylation to yield oligosaccharides of a higher degree of polymerization. The produced isomaltulose-derived oligosaccharides can be considered as isomalto-oligosaccharides (IMOs) because they are linked by only α-(1→6) bonds. In addition, having isomaltulose as the core structure, these IMO-like structures could possess appealing bioactive properties that could find potential applications as functional food ingredients.
El-Jeni, Rim; El Bour, Monia; Calo-Mata, Pilar; Böhme, Karola; Fernández-No, Inmaculada C; Barros-Velázquez, Jorge; Bouhaouala-Zahar, Balkiss
Novel lactic acid bacteria isolated from different organs of freshwater fish were examined for their potential application as probiotics in raw and processed foods. Four isolates of Enterococcus faecium and Leuconostoc mesenteroides were identified at the molecular level by 16S rRNA sequencing and random amplification of polymorphic DNA - polymerase chain reaction, and their antimicrobial activity against a panel of pathogens and food-poisoning bacteria was investigated. The whole bacteriocins of the 4 isolates were characterized by enterobacterial repetitive intergenic consensus sequences in PCR. The isolates exhibited high inhibitory activities against food-borne pathogens and spoilage microbial species and have significant probiotic profiles, since they survived at pH 3.0 and in the presence of bile salts, pancreatin, and pepsin, without any detectable hemolytic activity. Further, moderate heat resistance, adhesion ability to steel surfaces, and sensitivity to clinically relevant antimicrobial agents were revealed for all the isolates. These results highlight the specific probiotic properties of the strains and give evidence for potential application in minimally processed foods subjected to moderate heat processing.
Benmechernene, Zineb; Fernández-No, Inmaculada; Quintela-Baluja, Marcos; Böhme, Karola; Kihal, Mebrouk; Calo-Mata, Pilar; Barros-Velázquez, Jorge
Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS) which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk.
Benmechernene, Zineb; Fernández-No, Inmaculada; Quintela-Baluja, Marcos; Kihal, Mebrouk; Calo-Mata, Pilar; Barros-Velázquez, Jorge
Information on the microbiology of camel milk is very limited. In this work, the genetic characterization and proteomic identification of 13 putative producing bacteriocin Leuconostoc strains exhibiting antilisterial activity and isolated from camel milk were performed. DNA sequencing of the 13 selected strains revealed high homology among the 16S rRNA genes for all strains. In addition, 99% homology with Leuconostoc mesenteroides was observed when these sequences were analysed by the BLAST tool against other sequences from reference strains deposited in the Genbank. Furthermore, the isolates were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDITOF MS) which allowed for the identification of 2 mass peaks 6242 m/z and 5118 m/z that resulted to be specific to the species L. mesenteroides. Remarkably, the phyloproteomic tree provided more intraspecific information of L. mesenteroides than phylogenetic analysis. Accordingly, phyloproteomic analysis grouped L. mesenteroides strains into different subbranches, while all L. mesenteroides isolates were grouped in the same branch according to phylogenetic analysis. This study represents, to our knowledge, the first report on the use of MALDI-TOF MS on the identification of LAB isolated from camel milk. PMID:24809059
Metsoviti, Maria; Paramithiotis, Spiros; Drosinos, Eleftherios H; Skandamis, Panagiotis N; Galiotou-Panayotou, Maria; Papanikolaou, Seraphim
The aim of the present study was to evaluate the suitability of low-cost carbon sources for bacteriocin production by Leuconostoc mesenteroides strain E131. For this purpose, inexpensive sugars derived from a sugar refinery plant (glucose, fructose and sucrose) as well as waste molasses were utilized as carbon sources in submerged shake-flask experiments and the kinetic response of the microorganism was evaluated. Interestingly, in the case of molasses, non-negligible decolorization-detoxification (up to ∼27%) of the residue was performed together with the production of bacteriocin. In all instances the initial concentration of sugars employed was adjusted at 20 and 30 g/L, therefore the effect of both the nature and the initial quantity of sugar upon the growth of the microorganism was assessed. All media proved to be suitable for both biomass and bacteriocin production by L. mesenteroides, whereas variable quantities of lactate, acetate and ethanol were detected into the medium. Employment of fructose, sucrose or molasses as carbon sources resulted in the accumulation of mannitol (in some cases in significant quantities) into the medium; remarkable portion thus of the available or released fructose acted as electron acceptor instead of carbon source by the microorganism. The highest bacteriocin production achieved (=640 AU/mL) was obtained when initial glucose at 30 g/L was used as substrate. Finally, utilization of waste molasses as carbon source by L. mesenteroides resulted in satisfactory bacteriocin production (up to 320 AU/mL) besides the decolorization of the residue.
Weyker, Robert E; Glass, Kathleen A; Milkowski, Andrew L; Seman, Dennis L; Sindelar, Jeffrey J
Interest in natural/organic meat products has resulted in the need to validate the effectiveness of clean label antimicrobials to increase safety and shelf life of these products. A Response Surface Methodology (RSM) was used to investigate the effects of varying levels of moisture, pH, and a commercial "clean-label" antimicrobial (cultured sugar-vinegar blend; CSVB) on the growth rate of Listeria monocytogenes and Leuconostoc mesenteroides in uncured turkey stored at 4 °C for 16 wk. Twenty treatment combinations of moisture (60% to 80%), pH (5.8 to 6.4), and CSVB (2.5% to 5.0%) were evaluated during phase I to develop growth curves for both microbe types, whereas the interactive effects of pH (5.8 to 6.4) and CSVB (0.0 to 4.75) were tested in 16 treatment combinations during Phase II at a single moisture level using L. monocytogenes only. CSVB inhibited L. monocytogenes growth in 14 of the 20 treatments tested in Phase I and in 12 of the 16 treatments in Phase II through 16 and 8 wk, respectively. In contrast, CSVB had little effect on L. mesenteroides, with growth inhibited in only 4 of 20 treatments in Phase I and was therefore not tested further in Phase II. Significant interactions of the RSM design coefficients yielded a predictive model for L. mesenteroides growth rate, but due to lack of growth, no growth rate model was developed for L. monocytogenes. CSVB was found to be an effective antilisteral antimicrobial, while having little effect on a spoilage microorganism.
Jin, Qing; Li, Ling; Moon, Jin Seok; Cho, Seung Kee; Kim, Yu Jin; Lee, Soo Jin; Han, Nam Soo
The D-form of lactate, which causes metabolic stress upon excessive dietary intake, is mainly produced by Leuconostoc sp., the predominant species in sauerkraut. To shift the metabolic flux of d-lactate from pyruvate to l-lactate, we expressed the l-lactate dehydrogenase (ldhL) gene in Leuconostoc mesenteroides ATCC 8293. The ldhL gene from Lactobacillus plantarum was introduced into L. mesenteroides using the shuttle vectors pLeuCM and pLeuCM42. To elevate the expression level of ldhL in L. mesenteroides, the nucleotides for pyruvate kinase promoter were fused to ldhL and cloned into above vectors to construct pLC18pkL and pLC42pkL. As results, introduction of pLC42pkL in L. mesenteroides significantly improved both l-LDH activity and l-lactate productivity during fermentation, decreasing the d-/l-lactate ratio. When used as a starter culture for sauerkraut fermentation, recombinant L. mesenteroides harboring pLC42pkL increased l-lactate concentration and decreased d-lactate concentration compared to the wild type strain. We newly developed a recombinant L. mesenteroides which has high l-lactate dehydrogenase activity and applied this strain to minimize the harmful effect of d-lactate during the sauerkraut fermentation. To the best of our knowledge, we demonstrate for the first time the effective use of recombinant Leuconostoc sp. for quality improvement of fermented foods.
Eom, Ji-Eun; Moon, Gi-Seong
1,4-Dihydroxy-2-naphthoic acid (DHNA), a precursor of menaquinone (vitamin K2), has an effect on growth stimulation of bifidobacteria and prevention of osteoporosis, making it a promising functional food material. Therefore, we tried to clone the menB gene encoding DHNA synthase from Leuconostoc mesenteroides CJNU 0147. Based on the genome sequence of Leu. mesenteroides ATCC 8293 (GenBank accession no., CP000414), a primer set (Leu_menBfull_F and Leu_menBfull_R) was designed for the PCR amplification of menB gene of CJNU 0147. A DNA fragment (1,190 bp), including the menB gene, was amplified, cloned into pGEM-T Easy vector, and sequenced. The deduced amino acid sequence of MenB (DHNA synthase) protein of CJNU 0147 had a 98% similarity to the corresponding protein of ATCC 8293. The menB gene was subcloned into pCW4, a lactic acid bacteria - E. coli shuttle vector, and transferred to CJNU 0147. The transcription of menB gene of CJNU 0147 (pCW4::menB) was increased, when compared with those of CJNU 0147 (pCW4) and CJNU 0147 (-). The DHNA was produced from it at a detectable level, indicating that the cloned menB gene of CJNU 0147 encoded a DHNA synthase which is responsible for the production of DHNA, resulting in an increase of bifidogenic growth stimulation activity.
Davidović, Slađana; Miljković, Miona; Lazić, Vesna; Jović, Danica; Jokić, Bojan; Dimitrijević, Suzana; Radetić, Maja
This study was aimed to highlight the possibility of cotton fabric impregnation with silver nanoparticles synthesized by dextran isolated from Leuconostoc mesenteroides T3 in order to obtain antimicrobial properties. The fabrication of dextran was proved by FTIR spectroscopy. Particle sizes of synthesized dextran and silver nanoparticles were measured by dynamic light scattering method. The presence of silver nanoparticles on the surface of cotton fabric was confirmed by scanning electron microscopy, X-ray diffraction measurements and reflectance spectrophotometry. Antimicrobial activity of cotton fabric impregnated with silver nanoparticles was tested against bacteria Escherichia coli and Staphylococcus aureus, and fungus Candida albicans. The results indicated that synthesized silver nanoparticles can provide satisfactory antimicrobial activity. However, maximum reduction (99.9%) of all tested microorganisms can be obtained only when 1.0mmolL(-1) colloid consisting of silver nanoparticles is applied.
Giles-Gómez, Martha; Sandoval García, Jorge Giovanni; Matus, Violeta; Campos Quintana, Itzia; Bolívar, Francisco; Escalante, Adelfo
Pulque is a Mexican traditional alcoholic, non-distilled, fermented beverage produced by the fermentation of the sap, known as aguamiel, extracted from several maguey (Agave) species. Pulque has traditionally been considered a healthy beverage due to its nutrient content and also a traditional medicine for the treatment of gastrointestinal disorders and intestinal infections. During pulque fermentation, the development of acidity, alcohol and viscosity define its final sensorial properties, developing an enriched environment where dominant lactic acid bacteria (LAB), including diverse Leuconostoc species, are present. Because traditional pulque is consumed directly from the fermentation vessel, the naturally associated LAB are ingested and reach the human small intestine alive. Here, we report the in vitro and in vivo probiotic assessment of Leuconostoc mesenteroides strain P45 isolated from pulque. This isolated LAB species exhibited lysozyme, acid (pH 3.5) and bile salts (0.1 and 0.3 % oxgall) resistance. Antibacterial activity against the pathogens Listeria monocytogenes, enteropathogenic Escherichia coli, Salmonella enterica serovar Typhi and S. enterica serovar Typhimurium were observed in assays involving cell-to-cell contact, cell-free 2× concentrated supernatants and cell-to-cell contact under exopolysaccharide-producing conditions. The in vivo probiotic assessment showed an anti-infective activity of L. mesenteroides P45 against S. enterica serovar Typhimurium in challenged male and female BALB/c mice. Analysis of the available genome sequence of strain P45 allowed identified a pre-bacteriocin coding gene and six peptidoglycan hydrolase enzymes, probably involved in the antimicrobial activity of this strain. The results presented in this study support some potential microbial mechanisms associated with the beneficial effects on human health of this LAB involved in the fermentation of pulque.
Lactococcus lactis and Lactobacillus sakei as bio-protective culture to eliminate Leuconostoc mesenteroides spoilage and improve the shelf life and sensorial characteristics of commercial cooked bacon.
Comi, Giuseppe; Andyanto, Debbie; Manzano, Marisa; Iacumin, Lucilla
Cooked bacon is a typical Italian meat product. After production, cooked bacon is stored at 4 ± 2 °C. During storage, the microorganisms that survived pasteurisation can grow and produce spoilage. For the first time, we studied the cause of the deterioration in spoiled cooked bacon compared to unspoiled samples. Moreover, the use of bio-protective cultures to improve the quality of the product and eliminate the risk of spoilage was tested. The results show that Leuconostoc mesenteroides is responsible for spoilage and produces a greening colour of the meat, slime and various compounds that result from the fermentation of sugars and the degradation of nitrogen compounds. Finally, Lactococcus lactis spp. lactis and Lactobacillus sakei were able to reduce the risk of Leuconostoc mesenteroides spoilage.
Moon, Young Hwan; Madsen, Lee; Chung, Chang-Ho; Kim, Doman; Day, Donal F
We have previously demonstrated the production of glucooligosaccharides via a fermentation of sucrose with Leuconostoc mesenteroides NRRL B-742 using sodium hydroxide (NaOH) to control the pH. Because NaOH is expensive, we sought to minimize the cost of our process by substituting hydrated lime and saccharate of lime (lime sucrate) in its place. The yield of glucooligosaccharides using either 5 % lime (41.4 ± 0.5 g/100 g) or 5 % lime sucrate (40.0 ± 1.4 g/100 g) were both similar to the NaOH control (42.4 ± 1.5 g/100 g). Based on this, it appears that the cost associated with pH control in our process can be reduced by a factor of approximately 2.4 using lime instead of NaOH. Because our chromatographic stage is based on a Ca(2+)-form resin to separate glucooligosaccharides, the use of lime not only negates the need for costly de-salting via ion-exchange (elimination of two ion-exchange sections) prior to separation, but also greatly reduces the resin regeneration cost.
Yi, Young-Joo; Lim, Jeong-Muk; Gu, Suna; Lee, Wan-Kyu; Oh, Eunyoung; Lee, Sang-Myeong; Oh, Byung-Taek
It has been demonstrated that certain lactic acid bacteria (LAB) can sequester metal ions by binding them to their surfaces. In the present study, lead (Pb)-resistant LAB were isolated from kimchi, a Korean fermented food. A total of 96 different LAB strains were isolated, and 52 strains showed lead resistance. Among them, an LAB strain-96 (L-96) identified as Leuconostoc mesenteroides showed remarkable Pb resistance and removal capacity. The maximum adsorption capacity of this strain calculated using the Langmuir isotherm was 60.6 mg Pb/g. In an in vivo experiment, young male mice were provided with water (A), Pb-water (B), or Pb-water+ L-96 (C) during puberty. Lower glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT) levels in Pb-exposed male mice that received strain L-96 as a probiotic were suggestive of reduced hepatotoxicity. Moreover, feces from mice treated with L-96 contained more Pb than feces from untreated mice. Increased Pb elimination likely reduced internal accumulation, and this hypothesis was supported by significantly lower Pb concentrations in kidneys and testes of the mice treated with strain L-96. The motility and ATP content of epididymal spermatozoa were partially restored if strain L-96 was administered. In conclusion, isolated L-96 LAB had lead-biosorption activity and efficiently detoxified lead-poisoned male mice, resulting in recovering male reproductive function. These results suggest the potential use of LAB as a probiotic to protect humans from the adverse effects of Pb exposure.
Masuda, Yoshimitsu; Ono, Hiroshi; Kitagawa, Hiroshi; Ito, Haruo; Mu, Fuqin; Sawa, Naruhiko; Zendo, Takeshi; Sonomoto, Kenji
The culture supernatant of Leuconostoc mesenteroides TK41401, isolated from Japanese pickles, possessed antimicrobial activity against broad range of a bacterial genera and particularly strong activity against Bacillus coagulans, the major contaminant of pickles. An antimicrobial peptide was purified in three chromatographic steps, and its molecular mass was determined to be 6,115.59 Da by electrospray ionization time-of-flight mass spectrometry (ESI-TOF MS). The primary structure of this peptide was determined by amino acid and DNA sequencing, and these analyses revealed that it was translated as a 63-residue precursor. This precursor showed high similarity to the precursor of lactocyclicin Q, a cyclic bacteriocin produced by Lactococcus sp. strain QU 12. The molecular weight calculated after cyclization, which was presumed to involve the same process as in lactocyclicin Q (between L3 and W63), agreed with that estimated by ESI-TOF MS. This peptide was proved to be a novel cyclic bacteriocin, and it was termed leucocyclicin Q. The antimicrobial spectrum of this bacteriocin clearly differed from that of lactocyclicin Q, even though their primary structures were quite similar. This is the first report of a cyclic bacteriocin produced by a strain of the genus Leuconostoc. PMID:21948835
Dols, M; Chraibi, W; Remaud-Simeon, M; Lindley, N D; Monsan, P F
The metabolic and energetic properties of Leuconostoc mesenteroides have been examined with the goal of better understanding the parameters which affect dextransucrase activity and hence allowing the development of strategies for improved dextransucrase production. Glucose and fructose support equivalent specific growth rates (0.6 h-1) under aerobic conditions, but glucose leads to a better biomass yield in anaerobiosis. Both sugars are phosphorylated by specific hexokinases and catabolized through the heterofermentative phosphoketolase pathway. During sucrose-grown cultures, a large fraction of sucrose is converted outside the cell by dextransucrase into dextran and fructose and does not support growth. The other fraction enters the cell, where it is phosphorylated by an inducible sucrose phosphorylase and converted to glucose-6-phosphate (G-6-P) by a constitutive phosphoglucomutase and to heterofermentative products (lactate, acetate, and ethanol). Sucrose supports a higher growth rate (0.98 h-1) than the monosaccharides. When fructose is not consumed simultaneously with G-1-P, the biomass yield relative to ATP is high (16.8 mol of ATP.mol of sucrose-1), and dextransucrase production is directly proportional to growth. However, when the fructose moiety is used, a sink of energy is observed, and dextransucrase production is no longer correlated with growth. As a consequence, fructose catabolism must be avoided to improve the amount of dextransucrase synthesized. PMID:9172334
Lee, W. T.; Levy, H. R.
Leuconostoc mesenteroides glucose 6-phosphate dehydrogenase (G6PD) was isolated in high yield and purified to homogeneity from a newly constructed strain of Escherichia coli which lacks its own glucose 6-phosphate dehydrogenase gene. Lys-21 is one of two lysyl residues in the enzyme previously modified by the affinity labels pyridoxal 5'-phosphate and pyridoxal 5'-diphosphate-5'-adenosine, which are competitive inhibitors of the enzyme with respect to glucose 6-phosphate (LaDine, J.R., Carlow, D., Lee, W.T., Cross, R.L., Flynn, T.G., & Levy, H.R., 1991, J. Biol. Chem. 266, 5558-5562). K21R and K21Q mutants of the enzyme were purified to homogeneity and characterized kinetically to determine the function of Lys-21. Both mutant enzymes showed increased Km-values for glucose 6-phosphate compared to wild-type enzyme: 1.4-fold (NAD-linked reaction) and 2.1-fold (NADP-linked reaction) for the K21R enzyme, and 36-fold (NAD-linked reaction) and 53-fold (NADP-linked reaction) for the K21Q enzyme. The Km for NADP+ was unchanged in both mutant enzymes. The Km for NAD+ was increased 1.5- and 3.2-fold, compared to the wild-type enzyme, in the K21R and K21Q enzymes, respectively. For the K21R enzyme the kcat for the NAD- and NADP-linked reactions was unchanged. The kcat for the K21Q enzyme was increased in the NAD-linked reaction by 26% and decreased by 30% in the NADP-linked reaction from the values for the wild-type enzyme. The data are consistent with Lys-21 participating in the binding of the phosphate group of the substrate to the enzyme via charge-charge interaction. PMID:1304341
Funane, K; Shiraiwa, M; Hashimoto, K; Ichishima, E; Kobayashi, M
The treatment of Leuconostoc mesenteroides B-512F dextransucrase with 10 mM 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide (EDC) and glycine ethyl ester (GEE) inactivated the enzyme almost completely within 24 min where the modification of one carboxyl group/mol of the enzyme by EDC was attained. Though 30 mM diethyl pyrocarbonate (DEP) also inactivated the enzyme, about 35% of the activity remained during a 36-min incubation. When 10 mol of imidazole residues/mol of the enzyme was modified by DEP, 50% of the activity was still retained. The addition of the substrate sucrose greatly retarded the enzyme inactivation by EDC. However, the addition of dextran slightly protected the inactivation of the glucosyl-transferring activity and accelerated the inactivation of the sucrose-cleaving activity. In the case of DEP, the addition of sucrose or dextran gave no influence on the inactivation of the enzyme. Therefore, the carboxyl group seemed to play a more important role in the substrate binding and in the catalytic activity of the dextransucrase than the imidazolium group. Differential labeling of Leuconostoc dextransucrase by EDC was conducted in the presence of a sucrose analog, sucrose monocaprate. The fluorescent probe N-(1-naphthyl)ethylenediamine (EDAN) was used as the nucleophile instead of GEE. A fluorescent labeled peptide was isolated from a trypsin digest of the EDC-EDAN modified enzyme. The amino acid sequence of the isolated peptide was Leu-Gln-Glu-Asp-Asn-Ser-Asn-Val-Val-Val-Glu-Ala.(ABSTRACT TRUNCATED AT 250 WORDS)
Di Cagno, Raffaella; Filannino, Pasquale; Vincentini, Olimpia; Lanera, Alessia; Cavoski, Ivana; Gobbetti, Marco
Strains of Leuconostoc mesenteroides were identified from raw prickly pear (Opuntia ficus-indica L.). Five autochthonous strains were selected based on the kinetics of growth and acidification on prickly pear fruit juice, and the capacity to synthesize exo-polysaccharides. All selected Leuc. mesenteroides strains showed an in vitro mucilage-degrading capability. A protocol for processing and storage of fermented prickly pear fruit puree (FP) was set up. Unstarted FP and chemically acidified FP were used as the controls. Starters grew and remained viable at elevated cell numbers during 21 days of storage at 4 °C. Contaminating Enterobacteriaceae and yeasts were found only in the controls. Viscosity and serum separation distinguished started FP compared to the controls. Colour parameters, browning index, sensory attributes, antimicrobial activity, vitamin C and betalains levels were positively affected by lactic acid fermentation. Increase of free radical scavenging activity in ethyl acetate soluble extract suggested an effect of selected strains on phenolic profiles. Started FP markedly inhibited the inflammatory status of Caco-2/TC7 cells, and also contributed to maintaining the integrity of tight junctions. Started FP scavenged the reactive oxygen species generated by H2O2 on Caco-2 cells. All selected strain variously affected the immunomodulatory activity towards anti- and pro-inflammatory cytokines.
MATSUZAKI, Chiaki; MATSUMOTO, Kenji; KATOH, Toshihiko; YAMAMOTO, Kenji; HISA, Keiko
The effects of Leuconostoc mesenteroides strain NTM048 and type strain JCM6124T on the murine immune system were characterized. Although the bacterial cells and exopolysaccharides of each strain induced immunoglobulin A production in Peyer’s patch cells, the effects of NTM048 were more potent than those of JCM6124T. Oral administration of the cells of each strain increased the fecal immunoglobulin A content in NTM048-treated mice, but not in JCM6124T-treated mice. A flow cytometric analysis showed that the CD4+ T-cell populations in the mouse spleens tended to increase in the NTM048 group. These results suggest that immunomodulating ability is characteristic of strain NTM048. PMID:26858930
VidyaLaxme, B; Rovetto, A; Grau, R; Agrawal, Renu
Finger millet (Elucine corocana), locally known as ragi, and probiotics have been recognized for their health benefits. In the present work we describe novel probiotic ragi malt (functional food) that has been prepared using ragi and probiotic Leuconostoc mesenteroides (Lm) and Bacillus subtilis natto (Bs), alone and in combination, for antagonistic activity against Vibrio cholerae (Vc). In vitro studies using pure cultures showed that each probiotic strain (Lm or Bs) was able to inhibit the planktonic growth of Vc as well as its ability to make biofilms and adhere to extracellular matrix proteins (fibronectin, Fn) that may function in vivo as initial ports of entrance of the pathogen. Interestingly, the combination of both probiotic strains (Lm plus Bs) produced the strongest activity against the Vc. When both cultures were used together in the ragi malt the antimicrobial activity against Vc was enhanced due to synergistic effect of both probiotic strains. The inclusion of both probiotic strains in the functional food produced higher amounts of beneficial fatty acids like linoleic and linolenic acid and increased the mineral content (iron and zinc). The viability and activity of Lm and Bs against Vc was further enhanced with the use of adjuvants like ascorbic acid, tryptone, cysteine hydrochloride and casein hydrolysate in the ragi malt. In sum, the intake of probiotic ragi malt supplemented with Lm and Bs may provide nutrition, energy, compounds of therapeutic importance and antagonistic activity against Vc to a large extent to the consumer.
Kothari, Damini; Goyal, Arun
Gentio-oligosaccharides (GnOS) were synthesized by the acceptor reaction of dextransucrase from Leuconostoc mesenteroides NRRL B-1426 with gentiobiose and sucrose. GnOS were purified by gel permeation chromatography using a Bio-Gel P-2 column and identified by mass spectrometry. The purified GnOS (degree of polymerization ≥3) were investigated for their in vitro prebiotic and cytotoxic activity. GnOS exhibited a significantly lower degree of digestibility of 18.1% by simulated human gastric juice (pH 1.0) and 7.1% by human α-amylase (pH 7.0) after 6 h, whereas inulin, a standard prebiotic, showed 39.7% and 12.8% of digestibility, respectively. The prebiotic score showed that GnOS significantly supported the growth of probiotics such as Bifidobacterium infantis and Lactobacillus acidophilus and was comparable to that of inulin. The selective inhibitory effect of GnOS on human colon carcinoma (HT-29) cells revealed its potential as an anti-cancer agent that can serve as a functional food additive for the benefit of human health.
Kim, Doman; Robyt, John F; Lee, So-Young; Lee, Jin-Ha; Kim, Young-Min
Reactions of Leuconostoc mesenteroides B-512FMCM dextransucrase with increasing concentrations of sucrose, from 0.1 to 4.0 M, gave a decreasing amount of high-molecular weight dextran (HMWD) (>10(6) Da) with a concomitant increase in low-molecular weight dextran (LMWD) (<10(5) Da). At 0.1 M sucrose, pH 5.5, and 28 degrees C, 99.8% of the dextran had a MW>10(6) Da and at 4.0 M sucrose, 69.9% had a MW<10(5) Da and 30.1% had a MW>10(6) Da, giving a bimodal distribution. The degree of branching increased from 5% for 0.1 M sucrose to 16.6% for 4.0 M sucrose. The temperature had very little effect on the size of the dextran, which was >10(6) Da, but it had a significant effect on the degree of branching, which was 4.8% at 4 degrees C and increased to 14.7% at 45 degrees C. Both the molecular weight (MW) and the degree of branching were not significantly affected by different pH values between 4.5 and 6.0.
Wolf, Barry F; Fogler, H Scott
Bacterial profile modification (BPM), a form of tertiary oil recovery, diverts water from the water-flooded high-permeability zone into the oil-bearing low-permeability zone. During field use, exopolymer-producing bacteria plug the high-permeability zone only in the immediate vicinity of the injection point (the near-well bore region). For effective BPM the plug must penetrate far into the formation. Slowing the specific growth rate, lengthening the lag phase, and slowing the polymerization rate are techniques that can prolong the onset of biopolymer gelation and extend the depth of the biological plug. In batch experiments, the growth of Leuconostoc mesenteroides NRRL-B523 was inhibited by the synergistic effects of high substrate loading and an alkaline pH. Exponential growth was delayed up to 190 h. It was observed that cell division was significantly retarded until the medium pH, reduced by the acid byproducts of fermentation, reached a critical value of 6.79 +/- 0.06. A mathematical model was developed to describe the relationship between specific growth rate, lag time, and medium pH.
Effect of Lactobacillus buchneri, Lactobacillus fermentum, Leuconostoc mesenteroides inoculants, or a chemical additive on the fermentation, aerobic stability, and nutritive value of crimped wheat grains.
Adesogan, A T; Salawu, M B; Ross, A B; Davies, D R; Brooks, A E
The preservation of crimped wheat grains by three bacterial inoculants or a chemical additive was compared. Crimped wheat grain [56.8 g dry matter (DM)/kg] was conserved in 1.75-kg plastic bag, mini-silos without treatment, with 4L/tonne of Crimpstore (CS; an additive containing a mixture of ammonium formate, propionate, ethyl benzoate, and benzoate, SAS Kelvin Cave, Ltd., UK) or 1 x 10(5) cfu/g of each of three inoculant additives containing Lactobacillus fermentum (A), Leuconostoc mesenteroides (B), and Lactobacillus buchneri (C). Six replicates were conserved per treatment. Ensiling DM losses, chemical composition, fermentation characteristics, and aerobic stability were measured in the silages after 68 d of ensiling. All the silages were well fermented and remained stable for 84 h after aeration. Subsequently, the rate of deterioration was slowest in crimped grains treated with CS treatment, followed by those treated with inoculant C, while those treated with inoculant A deteriorated most rapidly. Residual water-soluble carbohydrate concentration was higher in crimped grains treated with CS than those treated with the inoculants. Ammonia nitrogen concentrations were lowest in CS-treated crimped grains, followed by inoculants C and A. DM losses were greater in CS-treated crimped grains than in crimped grains treated with inoculants A and C. In vivo digestibility was also measured in Texel-cross lambs fed a grass silage basal diet supplemented with the additive-treated crimped grains or a conventional, lamb finisher concentrate. Dry matter intake and digestibility were unaffected by treatment. In conclusion, bacterial inoculants containing L. buchneri are promising preservatives for crimped wheat grains.
Fleury, Y; Dayem, M A; Montagne, J J; Chaboisseau, E; Le Caer, J P; Nicolas, P; Delfour, A
A 37-residue cationic antimicrobial peptide named mesentericin Y 105(37) was purified to homogeneity from cell-free culture supernatant of the Gram-positive bacterium Leuconostoc mesenteroides. The complete amino acid sequence of the peptide, KYYGNGVHCTKSGCSVNWGEAASAGIHRLANGGNGFW, has been established by automated Edman degradation, mass spectrometry, and solid phase synthesis. Mesentericin Y 105(37) contains a single intramolecular disulfide bond that forms a 6-membered ring within the molecule. Mesentericin Y 105(37) was synthesized by the solid phase method. The synthetic replicate was shown to be indistinguishable from the natural peptide with respect to electrophoretic and chromatographic properties, mass spectrometry analysis, automated amino acid sequence determination, and antimicrobial properties. At nanomolar concentrations, synthetic mesentericin Y 105(37) is active against Gram+ bacteria in the genera Lactobacillus and Carnobacterium. Most interestingly, the peptide is inhibitory to the growth of the food-borne pathogen Listeria. CD spectra of mesentericin Y 105(37) in low polarity medium, which mimic the lipophilicity of the membrane of target organisms, indicated 30-40% alpha-helical conformation, and predictions of secondary structure suggested that the peptide can be configured as an amphipathic helix spanning over residues 17-31. To reveal the molecular basis of the specificity of mesentericin Y 105(37) targetting and mode of action, NH2- or COOH-terminally truncated analogs together with point-substituted analogs were synthesized and evaluated for their ability to inhibit the growth of Listeria ivanovii. In sharp contrast with broad spectrum alpha-helical antimicrobial peptides from vertebrate animals, which can be shortened to 14-18 residues without deleterious effect on potency, molecular elements responsible for anti-Listeria activity of mesentericin Y 105(37) are to be traced at once to the NH2-terminal tripeptide KYY, the disulfide bridge
Itoi, Shiro; Abe, Takeshi; Washio, Sayaka; Ikuno, Erika; Kanomata, Yuna; Sugita, Haruo
We isolated lactic acid bacteria from the intestinal tract of the pufferfish Takifugu niphobles caught in Shimoda, Shizuoka, Japan by using MRS broth prepared with 50% seawater. Additional screening was carried out using phenotypic tests such as Gram staining, cell morphology, catalase, oxidase and fermentation of glucose. Subsequently 227 isolates screened by the phenotypic tests were subjected to species-specific PCR for Lactococcus lactis, resulting in four positive isolates. The 16S rRNA gene sequences from three isolates were highly similar to that of L. lactis subsp. lactis (DNA database accession number M58837), while that of one isolate was identical to that of Leuconostoc mesenteroides (AB023246). These isolates were characterized by API 50 CH for carbohydrate fermentation and other phenotypic criteria for salt tolerance, and the characteristics were compared with those of L. lactis subsp. lactis from a cheese starter culture. The carbohydrate fermentation profiles of these isolates were characteristic of L. lactis subsp. lactis strains, whereas the tolerance of these isolates to salt was higher than that of L. lactis subsp. lactis from the cheese starter culture: the new L. lactis isolates showed high salt tolerance in MRS-agar plates containing 200% seawater or 6% sodium chloride. This is the first report of the isolation of halotolerant strains of L. lactis subsp. lactis from a marine environment.
Corrosion is one of the most serious and challenging problems faced worldwide by industry. This research investigates the inhibition of corrosive behavior of SAE1010 steel by bacterial exopolysaccharides. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion inhibition of diffe...
Glucansucrases catalyze the transfer of D-glucopyranosyl units from sucrose to form a-glucan chains. Glucansucrases are capable of catalyzing the synthesis of several different a-glucosidic linkages that affect molecular mass, branching, and solubility of the polysaccharide. In general, a-glucans co...
Kim, D S; Fogler, H S
Biofilm formation by bacterial cells can be used to modify the subsurface permeability for the purpose of microbial enhanced oil recovery, bio-barrier formation, and in situ bioremediation. Once injected into the subsurface, the bacteria undergo starvation due to a decrease in nutrient supply and diffusion limitations in biofilms. To help understand the starvation response of bacteria in biofilms, the relationship between exopolymer formation and cell culturability was examined in a batch culture. The average cell diameter was observed to decrease from 0.8 micron to 0.35 micron 3 days after starvation began. Cell chain fragmentation was also observed during starvation. Cells that underwent starvation in the presence of insoluble exopolymers showed a slower rate of decrease in cell diameter and in cell chain length than cells without insoluble exopolymers. The rate of decrease in the average cell diameter and cell chain length were determined using a first order decay model. Cells starved in the presence of exopolymers showed greater culturability than cells starved without exopolymers. After 200 days starvation, 2.5 x 10(-3)% cells were culturable, but no increase in cell number was observed. During starvation, the exopolymer concentration remained constant, an indication that the exopolymer was not consumed by the starving bacteria as an alternative carbon or energy source.
Hamasaki, Yoshikatsu; Ayaki, Mitsuko; Fuchu, Hidetaka; Sugiyama, Masaaki; Morita, Hidetoshi
Three kinds of lactic acid bacteria were isolated from spoiling cooked meat products stored below 10°C. They were identified as Leuconostoc mesenteroides subsp. mesenteroides, Lactococcus lactis subsp. lactis, and Leuconostoc citreum. All three strains grew well in MRS broth at 10°C. In particular, L. mesenteroides subsp. mesenteroides and L. citreum grew even at 4°C, and their doubling times were 23.6 and 51.5 h, respectively. On the other hand, although the bacteria were initially below the detection limit (<10 CFU/g) in model cooked meat products, the bacterial counts increased to 108 CFU/g at 10°C after 7 to 12 days. PMID:12788779
Our previous work showed that substitution of an amino acid that is coupled with the +2 subsite adjacent to the transition stabilizer of a glucansucrase, which produces a water-insoluble glucan, resulted in significant changes in the structures and yields of the water-insoluble glucans produced. We ...
Furfural (furan-2-carboxaldehyde), formed during dilute acid hydrolysis of biomass, is an inhibitor of growth and ethanol production by Zymomonas mobilis. The present study used a biological pre-treatment to reduce that amount of furfural in a model biofuel fermentation broth. The pre-treatment in...
Bacterial root rot of sugar beet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, a study was conducted to identify resistan...
Kleppen, Hans Petter; Nes, Ingolf F; Holo, Helge
Dairy siphovirus φLmd1, which infects starter culture isolate Leuconostoc mesenteroides subsp. dextranicum A1, showed resistance to pasteurization and was able to grow on 3 of the 4 commercial starter cultures tested. Its 26,201-bp genome was similar to that of Leuconostoc phage of vegetable origin but not to those of dairy phages infecting Lactococcus.
Sievers, Martin; Uermösi, Christina; Fehlmann, Marc; Krieger, Sibylle
The nucleotide sequences of the genes encoding the F1F0-ATPase beta-subunit from Oenococcus oeni, Leuconostoc mesenteroides subsp. mesenteroides, Pediococcus damnosus, Pediococcus parvulus, Lactobacillus brevis and Lactobacillus hilgardii were determined. Their deduced amino acid sequences showed homology values of 79-98%. Data from the alignment and ATPase tree indicated that O. oeni and L. mesenteroides subsp. mesenteroides formed a group well-separated from P. damnosus and P. parvulus and from the group comprises L. brevis and L. hilgardii. The N-terminus of the F1F0-ATPase beta-subunit of O. oeni contains a stretch of additional 38 amino acid residues. The catalytic site of the ATPase beta-subunit of the investigated strains is characterized by the two conserved motifs GGAGVGKT and GERTRE. The amplified atpD coding sequences were inserted into the pCRT7/CT-TOPO vector using TA-cloning strategy and transformed in Escherichia coli. SDS-PAGE and Western blot analyses confirmed that O. oeni has an ATPase beta-subunit protein which is larger in size than the corresponding molecules from the investigated strains.
Papadelli, Marina; Zoumpopoulou, Georgia; Georgalaki, Marina; Anastasiou, Rania; Manolopoulou, Eugenia; Lytra, Ioanna; Papadimitriou, Konstantinos; Tsakalidou, Effie
The production of Greek-style natural black table olives remains an empirical process relying on spontaneous fermentation despite its economic significance. For this reason producers often resort to increased NaCl concentration of the brine to secure quality of the product. In this study we employ two lactic acid bacteria Leuconostoc mesenteroides subsp. mesenteroides Lm139 and Lactobacillus pentosus DSM 16366 as starters in separate laboratory low salinity fermentations of "Kalamon" cultivar olives, processed according to the Greek-style method. L. mesenteroides subsp. mesenteroides Lm139 was previously isolated from Kalamon olives laboratory spontaneous fermentations, while L. pentosus DSM 16366 was isolated from fermenting green olives prepared according to the Spanish-style method. Spontaneous olives fermentation was also performed as a control. Microbiological and physicochemical analyses of the brines revealed that the use of the starters had a significant effect on the olives fermentation, leading to a faster acidification due to the more efficient consumption of soluble sugars in the brines. The final pH value reached by each starter culture used indicates a successful lactic fermentation. The production of lactic acid by the starters and the concomitant drop of the pH value proved to inhibit enterobacteria in a shorter period of time compared to the spontaneous fermentation. Concluding, the use of either of the two lactic acid bacteria as starters in Greek-style Kalamon olives fermentation could lead to a more controllable fermentation at lower salinities. The resulting product could be of higher quality with extended shelf-life while being at the same time safer for the consumer.
Chen, Yi-sheng; Lin, Yu-hsuan; Pan, Shwu-fen; Ji, Si-hua; Chang, Yu-chung; Yu, Chi-rong; Liou, Min-shiuan; Wu, Hui-chung; Otoguro, Misa; Yanagida, Fujitoshi; Liao, Chen-chung; Chiu, Chi-ming; Huang, Bi-qiang
A coccal strain isolated from fresh broccoli was initially identified as Enterococcus saccharolyticus; however, molecular identification and phenotypic traits did not support this identification. DNA-DNA hybridization with the type strain of E. saccharolyticus (76.4 % relatedness), DNA G+C content (35.7 mol%), phylogenetic analysis based on 16S rRNA, pheS and rpoA gene sequences, rep-PCR fingerprinting and profiles of cellular fatty acids, whole-cell proteins and enzyme activities, together with carbohydrate metabolism characteristics, indicated that this strain is distinct and represents a novel subspecies, for which the name Enterococcus saccharolyticus subsp. taiwanensis subsp. nov. is proposed. The type strain is 812(T) ( = NBRC 109476(T) = BCRC 80575(T)). Furthermore, we present an emended description of Enterococcus saccharolyticus and proposal of Enterococcus saccharolyticus subsp. saccharolyticus subsp. nov. (type strain ATCC 43076(T) = CCUG 27643(T) = CCUG 33311(T) = CIP 103246(T) = DSM 20726(T) = JCM 8734(T) = LMG 11427(T) = NBRC 100493(T) = NCIMB 702594(T)).
Predominant genera of fecal microbiota in children with atopic dermatitis are not altered by intake of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium animalis subsp. lactis Bi-07.
Larsen, Nadja; Vogensen, Finn K; Gøbel, Rikke; Michaelsen, Kim F; Abu Al-Soud, Waleed; Sørensen, Søren J; Hansen, Lars H; Jakobsen, Mogens
The effect of probiotic bacteria Lactobacillus acidophilus NCFM and Bifidobacterium lactis Bi-07 on the composition of the Lactobacillus group, Bifidobacterium and the total bacterial population in feces from young children with atopic dermatitis was investigated. The study included 50 children randomized to intake of one of the probiotic strain or placebo. Microbial composition was characterized by denaturing gradient gel electrophoresis, quantitative PCR and, in a subset of subjects, by pyrosequencing of the 16S rRNA gene. The core population of the Lactobacillus group was identified as Lactobacillus gasseri, Lactobacillus fermentum, Lactobacillus oris, Leuconostoc mesenteroides, while the bifidobacterial community included Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium longum and Bifidobacterium catenulatum. The fecal numbers of L. acidophilus and B. lactis increased significantly after intervention, indicating survival of the ingested bacteria. The levels of Bifidobacterium correlated positively (P=0.03), while the levels of the Lactobacillus group negatively (P=0.01) with improvement of atopic eczema evaluated by the Severity Scoring of Atopic Dermatitis index. This correlation was observed across the whole study cohort and not attributed to the probiotic intake. The main conclusion of the study is that administration of L. acidophilus NCFM and B. lactis Bi-07 does not affect the composition and diversity of the main bacterial populations in feces.
Delgado, Susana; Alegría, Ángel; Salvetti, Elisa; Felis, Giovanna E.; Mayo, Baltasar; Torriani, Sandra
In spite of a global concern on the transfer of antibiotic resistances (AR) via the food chain, limited information exists on this issue in species of Leuconostoc and Weissella, adjunct cultures used as aroma producers in fermented foods. In this work, the minimum inhibitory concentration was determined for 16 antibiotics in 34 strains of dairy origin, belonging to Leuconostoc mesenteroides (18), Leuconostoc citreum (11), Leuconostoc lactis (2), Weissella hellenica (2), and Leuconostoc carnosum (1). Atypical resistances were found for kanamycin (17 strains), tetracycline and chloramphenicol (two strains each), and erythromycin, clindamycin, virginiamycin, ciprofloxacin, and rifampicin (one strain each). Surprisingly, L. mesenteroides subsp. mesenteroides LbE16, showed resistance to four antibiotics, kanamycin, streptomycin, tetracycline and virginiamycin. PCR analysis identified tet(S) as responsible for tetracycline resistance in LbE16, but no gene was detected in a second tetracycline-resistant strain, L. mesenteroides subsp. cremoris LbT16. In Leuconostoc mesenteroides subsp. dextranicum LbE15, erythromycin and clindamycin resistant, an erm(B) gene was amplified. Hybridization experiments proved erm(B) and tet(S) to be associated to a plasmid of ≈35 kbp and to the chromosome of LbE15 and LbE16, respectively. The complete genome sequence of LbE15 and LbE16 was used to get further insights on the makeup and genetic organization of AR genes. Genome analysis confirmed the presence and location of erm(B) and tet(S), but genes providing tetracycline resistance in LbT16 were again not identified. In the genome of the multi-resistant strain LbE16, genes that might be involved in aminoglycoside (aadE, aphA-3, sat4) and virginiamycin [vat(E)] resistance were further found. The erm(B) gene but not tet(S) was transferred from Leuconostoc to Enterococcus faecalis both under laboratory conditions and in cheese. This study contributes to the characterization of AR in the
Kantachote, Duangporn; Charernjiratrakul, Wilawan
The effects of 3 different methods for removing the initial air on the properties of fermented plant beverages produced from phom-nang seaweed (Gracilaria fisheri) and wild forest noni (Morinda coreia Ham.) were investigated. Only method M which covered the space above the fermentation liquid with a water filled plastic bag produced no surface film of yeast, had the highest acidity and also antibacterial activity from both plants after 90 days of fermentation. However, the yeast count still exceeded the standard guidelines for plant beverages. The fermented beverage from wild forest noni showed more antibacterial activity against 3 of 4 pathogenic bacteria tested than that from the phomnang seaweed, probably for its higher levels of acidity and ethanol content. Lactic Acid Bacteria (LAB) isolated from the fermentation samples from days 1-5 using the method M from both fermented plant beverages were Leuconostoc mesenteroides supsp. mesenteroides and Leu. mesenteroides subsp. dextranicum while presence of Lactobacilus plantarum was only recorded at days 4-5 in the wild forest noni beverage. From days 6-14 the isolates were Lactobacillus plantarum, Lactobacillus fermentum and Lactobacillus brevis from wild forest noni beverage, whereas only L. brevis was not detected in the seaweed beverage. During days 21-45 both beverages had a similar LAB population of L. plantarum and L. brevis while L. coryniformis was only found in the wild forest noni beverage. Between days 60-90 in both plant beverages only L. plantarum and Lactobacillius sp. were detected.
Mycobacterium avium (MA) is divided into four subspecies based primarily on host-range and consists of MA subsp. avium (birds), MA subsp. silvaticum (wood pigeons), MA subsp. paratuberculosis (broad, poorly-defined host range), and the recently described MA subsp. hominissuis (hu...
Wang, Joyce; Moolji, Jalal; Dufort, Alex; Staffa, Alfredo; Domenech, Pilar; Reed, Michael B.
ABSTRACT Mycobacterium avium subsp. paratuberculosis is a host-adapted pathogen that evolved from the environmental bacterium M. avium subsp. hominissuis through gene loss and gene acquisition. Growth of M. avium subsp. paratuberculosis in the laboratory is enhanced by supplementation of the media with the iron-binding siderophore mycobactin J. Here we examined the production of mycobactins by related organisms and searched for an alternative iron uptake system in M. avium subsp. paratuberculosis. Through thin-layer chromatography and radiolabeled iron-uptake studies, we showed that M. avium subsp. paratuberculosis is impaired for both mycobactin synthesis and iron acquisition. Consistent with these observations, we identified several mutations, including deletions, in M. avium subsp. paratuberculosis genes coding for mycobactin synthesis. Using a transposon-mediated mutagenesis screen conditional on growth without myobactin, we identified a potential mycobactin-independent iron uptake system on a M. avium subsp. paratuberculosis-specific genomic island, LSPP15. We obtained a transposon (Tn) mutant with a disruption in the LSPP15 gene MAP3776c for targeted study. The mutant manifests increased iron uptake as well as intracellular iron content, with genes downstream of the transposon insertion (MAP3775c to MAP3772c [MAP3775-2c]) upregulated as the result of a polar effect. As an independent confirmation, we observed the same iron uptake phenotypes by overexpressing MAP3775-2c in wild-type M. avium subsp. paratuberculosis. These data indicate that the horizontally acquired LSPP15 genes contribute to iron acquisition by M. avium subsp. paratuberculosis, potentially allowing the subsequent loss of siderophore production by this pathogen. IMPORTANCE Many microbes are able to scavenge iron from their surroundings by producing iron-chelating siderophores. One exception is Mycobacterium avium subsp. paratuberculosis, a fastidious, slow-growing animal pathogen whose growth
Gaglio, Raimondo; Scatassa, Maria Luisa; Cruciata, Margherita; Miraglia, Viviana; Corona, Onofrio; Di Gerlando, Rosalia; Portolano, Baldassare; Moschetti, Giancarlo; Settanni, Luca
Twelve lactic acid bacteria (LAB), previously selected in vitro (Gaglio et al., 2014), were evaluated in situ for their potential to act as starter cultures for the continuous four-season production of Vastedda-like cheese, made with raw ewes' milk. The strains belonged to Lactobacillus delbrueckii, Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides subsp. mesenteroides and Streptococcus thermophilus. LAB were first inoculated in multiple-strain combinations on the basis of their optimal growth temperatures in three process conditions which differed for milk treatment and medium for strain development: process 1, growth of strains in the optimal synthetic media and pasteurised milk; process 2, growth of strains in whey based medium (WBM) and pasteurised milk; and process 3, growth of strains in WBM and raw milk. The strains that acidified the curds in short time, as shown by a pH drop, were all mesophilic and were then tested in a single inoculum through process 3. Randomly amplified polymorphic DNA (RAPD)-PCR analysis applied to the colonies isolated from the highest dilutions of samples confirmed the dominance of the added strains after curd acidification, stretching and storage. After 15days of refrigerated storage, the decrease in pH values showed an activity of the mesophilic strains at low temperatures, but only Lc. lactis subsp. cremoris PON153, Ln. mesenteroides subsp. mesenteroides PON259 and PON559 increased their number during the 15days at 7°C. A sensory evaluation indicated that the cheeses obtained by applying protocol 3 and by inoculation with lactococci are the most similar to the protected denomination of origin (PDO) cheese and received the best scores by the judges. Thus, the experimental cheeses obtained with raw milk and inoculated with single and multiple combinations of lactococci were subjected to the analysis of the volatile organic compounds (VOCs) carried out by a headspace solid phase microextraction (SPME) technique coupled
Romero, Beatriz; Morosini, María-Isabel; Loza, Elena; Rodríguez-Baños, Mercedes; Navas, Enrique; Cantón, Rafael; del Campo, Rosa
All Streptococcus bovis blood culture isolates recovered from January 2003 to January 2010 (n = 52) at the Hospital Universitario Ramón y Cajal were reidentified on the basis of their genetic traits using new taxonomic criteria. Initial identification was performed by the semiautomatic Wider system (Fco. Soria-Melguizo, Spain) and the API 20 Strep system (bioMérieux, France). All isolates were reidentified by PCR amplification and sequencing of both the 16S rRNA and sodA genes and by mass spectrometry using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS; Bruker, Germany). Results of 16S rRNA/sodA gene sequencing were as follows: Streptococcus gallolyticus subsp. gallolyticus, 14/14 (number of isolates identified by 16S rRNA/number of isolates identified by sodA gene sequencing); Streptococcus gallolyticus subsp. pasteurianus, 24/24; Streptococcus spp., 7/0; Streptococcus infantarius subsp. infantarius, 0/2; Streptococcus lutetiensis, 0/5; Leuconostoc mesenteroides, 4/0; and Lactococcus lactis, 3/3. MALDI-TOF MS identified 27 S. gallolyticus isolates but not at the subspecies level, 4 L. mesenteroides isolates, 3 L. lactis isolates, and 6 S. lutetiensis isolates, whereas 12 isolates rendered a nonreliable identification result. Pulsed-field gel electrophoresis grouped all S. gallolyticus subsp. gallolyticus isolates into 3 major clusters clearly different from those of the S. gallolyticus subsp. pasteurianus isolates, which, in turn, exhibited no clonal relationship. The percentages of resistance to the tested antimicrobials were 38% for erythromycin, 23% for fosfomycin, 10% for levofloxacin, 6% for tetracycline, and 4% for co-trimoxazole. The most frequent underlying diseases were hepatobiliary disorders (53%), endocarditis (17%), and malignancies (12%). We conclude that sequencing of the sodA gene was the most discriminatory method and that S. gallolyticus subsp. pasteurianus appears to have a higher genetic diversity
Jung, Ji Young; Lee, Se Hee; Kim, Jeong Myeong; Park, Moon Su; Bae, Jin-Woo; Hahn, Yoonsoo; Madsen, Eugene L.; Jeon, Che Ok
Kimchi, a traditional food in the Korean culture, is made from vegetables by fermentation. In this study, metagenomic approaches were used to monitor changes in bacterial populations, metabolic potential, and overall genetic features of the microbial community during the 29-day fermentation process. Metagenomic DNA was extracted from kimchi samples obtained periodically and was sequenced using a 454 GS FLX Titanium system, which yielded a total of 701,556 reads, with an average read length of 438 bp. Phylogenetic analysis based on 16S rRNA genes from the metagenome indicated that the kimchi microbiome was dominated by members of three genera: Leuconostoc, Lactobacillus, and Weissella. Assignment of metagenomic sequences to SEED categories of the Metagenome Rapid Annotation using Subsystem Technology (MG-RAST) server revealed a genetic profile characteristic of heterotrophic lactic acid fermentation of carbohydrates, which was supported by the detection of mannitol, lactate, acetate, and ethanol as fermentation products. When the metagenomic reads were mapped onto the database of completed genomes, the Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 and Lactobacillus sakei subsp. sakei 23K genomes were highly represented. These same two genera were confirmed to be important in kimchi fermentation when the majority of kimchi metagenomic sequences showed very high identity to Leuconostoc mesenteroides and Lactobacillus genes. Besides microbial genome sequences, a surprisingly large number of phage DNA sequences were identified from the cellular fractions, possibly indicating that a high proportion of cells were infected by bacteriophages during fermentation. Overall, these results provide insights into the kimchi microbial community and also shed light on fermentation processes carried out broadly by complex microbial communities. PMID:21317261
Fitzgerald, Collette; Tu, Zheng Chao; Patrick, Mary; Stiles, Tracy; Lawson, Andy J; Santovenia, Monica; Gilbert, Maarten J; van Bergen, Marcel; Joyce, Kevin; Pruckler, Janet; Stroika, Steven; Duim, Birgitta; Miller, William G; Loparev, Vladimir; Sinnige, Jan C; Fields, Patricia I; Tauxe, Robert V; Blaser, Martin J; Wagenaar, Jaap A
A polyphasic study was undertaken to determine the taxonomic position of 13 Campylobacter fetus-like strains from humans (n = 8) and reptiles (n = 5). The results of matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS and genomic data from sap analysis, 16S rRNA gene and hsp60 sequence comparison, pulsed-field gel electrophoresis, amplified fragment length polymorphism analysis, DNA-DNA hybridization and whole genome sequencing demonstrated that these strains are closely related to C. fetus but clearly differentiated from recognized subspecies of C. fetus. Therefore, this unique cluster of 13 strains represents a novel subspecies within the species C. fetus, for which the name Campylobacter fetus subsp. testudinum subsp. nov. is proposed, with strain 03-427(T) ( = ATCC BAA-2539(T) = LMG 27499(T)) as the type strain. Although this novel taxon could not be differentiated from C. fetus subsp. fetus and C. fetus subsp. venerealis using conventional phenotypic tests, MALDI-TOF MS revealed the presence of multiple phenotypic biomarkers which distinguish Campylobacter fetus subsp. testudinum subsp. nov. from recognized subspecies of C. fetus.
Pantůček, Roman; Švec, Pavel; Dajcs, Joseph J; Machová, Ivana; Černohlávková, Jitka; Šedo, Ondrej; Gelbíčová, Tereza; Mašlaňová, Ivana; Doškař, Jiří; Zdráhal, Zbyněk; Růžičková, Vladislava; Sedláček, Ivo
Thirteen coagulase-negative, oxidase-negative, and novobiocin-susceptible staphylococci were isolated from human clinical specimens. The isolates were differentiated from known staphylococcal species on the basis of 16S rRNA, hsp60, rpoB, dnaJ, tuf, and gap gene sequencing, automated ribotyping, (GTG)5-PCR fingerprinting, and MALDI-TOF MS analysis. Phylogenetic analysis based on the 16S rRNA gene sequence indicated phylogenetic relatedness of the analyzed strains to Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus devriesei, and Staphylococcus lugdunensis. DNA-DNA hybridization experiments between representative strains CCM 8418(T), CCM 8421(T), and the closest phylogenetic neighbors confirmed that the isolates represent novel Staphylococcus species, for which the name Staphylococcus petrasii sp. nov. is proposed. Genotypic and phenotypic analyses unambiguously split the strains into two closely related subclusters. Based on the results, two novel subspecies S. petrasii subsp. petrasii subsp. nov. and S. petrasii subsp. croceilyticus subsp. nov. are proposed, with type strains CCM 8418(T) (=CCUG 62727(T)) and CCM 8421(T) (=CCUG 62728(T)), respectively.
Legionella pneumophila serogroup Lansing 3 isolated from a patient with fatal pneumonia, and descriptions of L. pneumophila subsp. pneumophila subsp. nov., L. pneumophila subsp. fraseri subsp. nov., and L. pneumophila subsp. pascullei subsp. nov.
Brenner, D J; Steigerwalt, A G; Epple, P; Bibb, W F; McKinney, R M; Starnes, R W; Colville, J M; Selander, R K; Edelstein, P H; Moss, C W
Previous DNA relatedness and enzyme electrophoretic mobility studies indicated heterogeneity among strains of Legionella pneumophila serogroups 1, 4, 5, and Lansing 3 (a new, as yet unnumbered serogroup). In this study 60 L. pneumophila strains were studied by DNA hybridization (hydroxyapatite method) to assess their genomic relatedness. These strains were also studied biochemically and serologically to determine whether they formed one or more phenotypic groups. DNA relatedness studies identified three groups. DNA group 1 contained the type strain Philadelphia 1 and strains from serogroups 1 through 14 of L. pneumophila. The average relatedness of DNA group 1 strains was 88% at 60 degrees C with 1.1% divergence in related sequences and 85% at 75 degrees C. DNA group 2 contained strain Los Angeles 1, the reference strain of serogroup 4, and strains of serogroups 1, 4, 5, and Lansing 3, an unnumbered serogroup. Average relatedness of DNA group 2 strains was 84% at 60 degrees C with 0.7% divergence and 87% at 75 degrees C. Reciprocal relatedness of DNA groups 1 and 2 was approximately 67% at 60 degrees C with 6.0% divergence and 48% at 75 degrees C. DNA group 3 strains were in serogroup 5. They were 98% related at 60 degrees C with 0.5% divergence and 97% related at 75 degrees C. Reciprocal relatedness of DNA group 3 and DNA group 1 was approximately 74% at 60 degrees C with 5.3% divergence and 43% at 75 degrees C, and reciprocal relatedness of DNA groups 3 and 2 was 66% at 60 degrees C with 5.7% divergence and 55% at 75 degrees C. The DNA groups could not be separated biochemically or serologically or by cell wall fatty acid and isoprenoid quinone composition. Three subspecies of L. pneumophila are proposed to accommodate the three DNA groups: L. pneumophila subsp. pneumophila subsp. nov. for DNA group 1, L. pneumophila subsp. fraseri subsp. nov. for DNA group 2, and pneumophila subsp. pascullei subsp. nov. for DNA group 3. PMID:3053773
Gutarowska, Beata; Matusiak, Katarzyna; Borowski, Sebastian; Rajkowska, Aleksandra; Brycki, Bogumił
Laboratory-scale experiments were conducted using poultry manure (PM) from a laying hen farm. Six strains of bacteria and one strain of yeast, selected on the base of the previous study, were investigated to evaluate their activity in the removal of odorous compounds from poultry manure: pure cultures of Bacillus subtilis subsp. spizizenii LOCK 0272, Bacillus megaterium LOCK 0963, Pseudomonas sp. LOCK 0961, Psychrobacter faecalis LOCK 0965, Leuconostoc mesenteroides LOCK 0964, Streptomyces violaceoruber LOCK 0967, and Candida inconspicua LOCK 0272 were suspended in water solution and applied for PM deodorization. The most active strains in the removal of volatile odorous compounds (ammonia, hydrogen sulfide, dimethylamine, trimethylamine, isobutyric acid) belonged to B. subtilis subsp. spizizenii, L. mesenteroides, C. inconspicua, and P. faecalis. In the next series of experiments, a mixed culture of all tested strains was immobilized on a mineral carrier being a mixture of perlite and bentonite (20:80 by weight). That mixed culture applied for PM deodorization was particularly active against ammonia and hydrogen sulfide, which were removed from the exhaust gas by 20.8% and 17.5%, respectively. The experiments also showed that during deodorization the microorganisms could reduce the concentrations of proteins and amino acids in PM. In particular, the mixed culture was active against cysteine and methionine, which were removed from PM by around 45% within 24 h of deodorization.
Schwab, Clarissa; Gänzle, Michael
Human milk contains about 7% lactose and 1% human milk oligosaccharides (HMOs) consisting of lactose with linked fucose, N-acetylglucosamine and sialic acid. In infant formula, galactooligosaccharides (GOSs) are added to replace HMOs. This study investigated the ability of six strains of lactic acid bacteria (LAB), Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus fermentum, Lactobacillus reuteri, Streptococcus thermophilus and Leuconostoc mesenteroides subsp. cremoris, to digest HMO components, defined HMOs, and GOSs. All strains grew on lactose and glucose. N-acetylglucosamine utilization varied between strains and was maximal in L. plantarum; fucose utilization was low or absent in all strains. Both hetero- and homofermentative LAB utilized N-acetylglucosamine via the Embden-Meyerhof pathway. Lactobacillus acidophilus and L. plantarum were the most versatile in hydrolysing pNP analogues and the only strains releasing mono- and disaccharides from defined HMOs. Whole cells of all six LAB hydrolysed oNP-galactoside and pNP-galactoside indicating β-galactosidase activity. High β-galactosidase activity of L. reuteri, L. fermentum, S. thermophilus and L. mesenteroides subsp. cremoris whole cells correlated to lactose and GOS hydrolysis. Hydrolysis of lactose and GOSs by heterologously expressed β-galactosidases confirmed that LAB β-galactosidases are involved in GOS digestion. In summary, the strains of LAB used were not capable of utilizing complex HMOs but metabolized HMO components and GOSs.
Samelis, J; Kakouri, A; Rementzis, J
Lactobacillus sakei subsp. carnosus was predominant in the spoilage flora of sliced, vacuum-packed, smoked, oven-cooked turkey breast fillets which developed mild, sour spoilage flavors after 4 weeks storage at 4 degrees C. In contrast, Leuconostoc mesenteroides subsp. mesenteroides predominated in the spoilage flora of sliced, vacuum-packed, unsmoked, boiled turkey breast fillets from the same plant which were also stored at 4 degrees C. The spoilage flora of the unsmoked breasts grew faster than that of the smoked breasts and was more diverse. Lactobacillus sakei, Weissella viridescens and an atypical group of leuconostoc-like bacteria were also members of the unsmoked turkey breasts flora. Consequently, the unsmoked breasts spoiled after 2 weeks at 4 degrees C: the packs swelled and the meat developed strong sour odors and flavors and abundant slime. Except for the unidentified leuconostocs, which apparently survived boiling of the unsmoked turkey, all the spoilage organisms contaminated the meats during the slicing and vacuum packaging operations. From their biochemical reactions and cellular fatty acid profiles, the atypical leuconostocs were more closely related to Leuconostoc carnosum than W. viridescens. Carnobacteria and Brochothrix thermosphacta were present in relatively large numbers on the raw turkey, but were not numerous in the spoilage flora of the cooked, vacuum-packed meat products.
The objective of this study was to identify the coccoidal bacteria present in 188 samples of fermented yaks’, mares’ and cows’ milk products collected from 12 different regions in Mongolia. Furthermore, we evaluated the fermentation properties of ten selected isolates of the predominant species, Streptococcus (S.) thermophiles, during the process of milk fermentation and subsequent storage of the resulting yoghurt at 4℃. Overall, 159 isolates were obtained from 188 samples using M17 agar. These isolates were presumed to be lactic acid bacteria based on their gram-positive and catalase-negative properties, and were identified to species level using 16S rRNA gene sequence analysis. These coccoid isolates were distributed in four genera and six species: Enterococcus (E.) durans, Enterococcus (E.) faecalis, Lactococcus (Lac.) subsp. lactis, Leuconostoc (Leuc.) lactis, Leuconostoc (Leuc.) mesenteroides. subsp. mesenteroides and S. thermophilus. Among these S. thermophilus was the most common species in most samples. From evaluation of the fermentation characteristics (viable counts, pH, titratable acidity [TA]) of ten selected S. thermophilus isolates we could identify four isolates (IMAU 20246, IMAU20764, IMAU20729 and IMAU20738) that were fast acid producers. IMAU20246 produced the highest concentrations of lactic acid and formic acid. These isolates have potential as starter cultures for yoghurt production. PMID:26761898
Campylobacter fetus venerealis biovar intermedius is a variant of Campylobacter fetus subsp. venerealis, the causative agent of Bovine Genital Campylobacteriosis. In contrast to Campylobacter fetus subsp. venerealis which is restricted to the genital tract of cattle, Campylobacter fetus subsp. vener...
Švec, Pavel; De Bel, Annelies; Sedláček, Ivo; Petráš, Petr; Gelbíčová, Tereza; Černohlávková, Jitka; Mašlanˇová, Ivana; Cnockaert, Margo; Varbanovová, Ivana; Echahidi, Fedoua; Vandamme, Peter; Pantuček, Roman
Seven coagulase-negative, oxidase-negative and novobiocin-susceptible staphylococci assigned tentatively as Staphylococcus petrasii were investigated in this study in order to elucidate their taxonomic position. All strains were initially shown to form a genetically homogeneous group separated from remaining species of the genus Staphylococcus by using a repetitive sequence-based PCR fingerprinting with the (GTG)5 primer. Phylogenetic analysis based on 16S rRNA gene, hsp60, rpoB, dnaJ, gap and tuf sequences showed that the group is closely related to Staphylococcus petrasii but separated from the three hitherto known subspecies, S. petrasii subsp. petrasii, S. petrasii subsp. croceilyticus and S. petrasii subsp. jettensis. Further investigation using automated ribotyping, MALDI-TOF mass spectrometry, fatty acid methyl ester analysis, DNA-DNA hybridization and extensive biotyping confirmed that the analysed group represents a novel subspecies within S. petrasii, for which the name Staphylococcus petrasii subsp. pragensis subsp. nov. is proposed. The type strain is NRL/St 12/356(T) ( = CCM 8529(T) = LMG 28327(T)).
Silva, I. C.; Regasini, L. O.; Petrônio, M. S.; Silva, D. H. S.; Bolzani, V. S.; Belasque, J.; Sacramento, L. V. S.
The plant-pathogenic bacterium Xanthomonas citri subsp. citri is the causal agent of Asiatic citrus canker, a serious disease that affects all the cultivars of citrus in subtropical citrus-producing areas worldwide. There is no curative treatment for citrus canker; thus, the eradication of infected plants constitutes the only effective control of the spread of X. citri subsp. citri. Since the eradication program in the state of São Paulo, Brazil, is under threat, there is a clear risk of X. citri subsp. citri becoming endemic in the main orange-producing area in the world. Here we evaluated the potential use of alkyl gallates to prevent X. citri subsp. citri growth. These esters displayed a potent anti-X. citri subsp. citri activity similar to that of kanamycin (positive control), as evaluated by the resazurin microtiter assay (REMA). The treatment of X. citri subsp. citri cells with these compounds induced altered cell morphology, and investigations of the possible intracellular targets using X. citri subsp. citri strains labeled for the septum and centromere pointed to a common target involved in chromosome segregation and cell division. Finally, the artificial inoculation of citrus with X. citri subsp. citri cells pretreated with alkyl gallates showed that the bacterium loses the ability to colonize its host, which indicates the potential of these esters to protect citrus plants against X. citri subsp. citri infection. PMID:23104804
D'Auria, Maurizio; Lorenz, Richard; Racioppi, Rocco; Romano, Vito Antonio
SPME-GC-MS analysis of the scent of Platanthera bifolia subsp. osca collected during the night showed as main components lilac alcohols B, C and D and lilac aldehydes A, B and C. Other significant chemical components were linalool and caryophyllene. Some differences were found in comparison with previously reported analyses of the scent of P. bifolia and Platanthera chlorantha. The most important difference found was in the composition of the ester fraction.
Muyanja, C M B K; Narvhus, J A; Treimo, J; Langsrud, T
lactis subsp. lactis (four strains), Leuconostoc mesenteroides subsp. mesenteroides (one strain), Leuconostoc mesenteroides subsp. dextranicum (one strain), Weissella confusa (one strain) and L. plantarum (one strain).
Balcázar, José Luis; de Blas, Ignacio; Ruiz-Zarzuela, Imanol; Vendrell, Daniel; Gironés, Olivia; Muzquiz, José Luis
The aim of this study was to identify lactic acid bacteria (LAB) using polymerase chain reaction (PCR) amplification of variable regions of the 16S rRNA gene. Thirteen LAB strains were isolated from the intestinal microbiota of healthy salmonids. A approximately 500-bp region of the highly conserved 16S rRNA gene was PCR-amplified and following this, a portion of the amplicon (272-bp) including the V1 and V2 variable regions was sequenced. The sequence containing both the V1 and V2 region provided strong evidence for the identification of LAB. The LAB strains were identified as Carnobacterium maltaromaticum, Lactobacillus curvatus, Lactobacillus sakei, Lactobacillus plantarum, Lactococcus lactis subsp. cremoris, Lactococcus lactis subsp. lactis, and Leuconostoc mesenteroides. The method described was found to be a very simple, rapid, specific, and low-cost tool for the identification of unknown strains of LAB.
Campylobacter hyointestinalis is isolated primarily from ruminants and swine, but is also occasionally isolated from humans. C. hyointestinalis is currently divided into two subspecies: subsps. hyointestinalis and lawsonii. This study describes the first closed whole-genome sequences of the subsp. h...
Fico, G; Braca, A; De Tommasi, N; Tomè, F; Morelli, I
Three flavonol glycosides quercetin 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (1), kaempferol 7-O-(6-trans-caffeoyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (2), and kaempferol 7-O-(6-trans-p-coumaroyl)-beta-glucopyranosyl-(1-->3)-alpha-rhamnopyranoside-3-O-beta-glucopyranoside (3), together with the known beta-3,4-dihydroxyphenethyl beta-glucopyranoside, were isolated from the flowers of Aconitum napellus subsp. neomontanum. Their structures were elucidated by spectroscopic methods, including 2D NMR spectral techniques.
There are few diseases that ignite as much fervor among horse owners as strangles. Streptococcus equi subsp equi (strangles) infections frequently require the treating veterinarian to manage not only the clinical cases but also the biosecurity and provision of information to all involved parties. Although the disease is typically characterized by low mortality and high morbidity, restrictions of horse movement that result from appropriate quarantine procedures often frustrate the involved parties. The aims of this article are to provide clinically relevant information for diagnosis, treatment, and biosecurity management of strangles infection.
Proposal to rename Carnobacterium inhibens as Carnobacterium inhibens subsp. inhibens subsp. nov. and description of Carnobacterium inhibens subsp. gilichinskyi subsp. nov., a psychrotolerant bacterium isolated from Siberian permafrost.
Nicholson, Wayne L; Zhalnina, Kateryna; de Oliveira, Rafael R; Triplett, Eric W
A novel, psychrotolerant facultative anaerobe, strain WN1359(T), was isolated from a permafrost borehole sample collected at the right bank of the Kolyma River in Siberia, Russia. Gram-positive-staining, non-motile, rod-shaped cells were observed with sizes of 1-2 µm long and 0.4-0.5 µm wide. Growth occurred in the range of pH 5.8-9.0 with optimal growth at pH 7.8-8.6 (pH optimum 8.2). The novel isolate grew at temperatures from 0-37 °C and optimal growth occurred at 25 °C. The novel isolate does not require NaCl; growth was observed between 0 and 8.8 % (1.5 M) NaCl with optimal growth at 0.5 % (w/v) NaCl. The isolate was a catalase-negative, facultatively anaerobic chemo-organoheterotroph that used sugars but not several single amino acids or dipeptides as substrates. The major metabolic end-product was lactic acid in the ratio of 86 % l-lactate : 14 % d-lactate. Strain WN1359(T) was sensitive to ampicillin, chloramphenicol, fusidic acid, lincomycin, monocycline, rifampicin, rifamycin SV, spectinomycin, streptomycin, troleandomycin and vancomycin, and resistant to nalidixic acid and aztreonam. The fatty acid content was predominantly unsaturated (70.2 %), branched-chain unsaturated (11.7 %) and saturated (12.5 %). The DNA G+C content was 35.3 mol% by whole genome sequence analysis. 16S rRNA gene sequence analysis showed 98.7 % sequence identity between strain WN1359(T) and Carnobacterium inhibens. Genome relatedness was computed using both Genome-to-Genome Distance Analysis (GGDA) and Average Nucleotide Identity (ANI), which both strongly supported strain WN1359(T) belonging to the species C. inhibens. On the basis of these results, the permafrost isolate WN1359(T) represents a novel subspecies of C. inhibens, for which the name Carnobacterium inhibens subsp. gilichinskyi subsp. nov. is proposed. The type strain is WN1359(T) ( = ATCC BAA-2557(T) = DSM 27470(T)). The subspecies Carnobacterium inhibens subsp. inhibens subsp. nov. is created automatically. An
Monteagudo-Mera, A; Caro, I; Rodríguez-Aparicio, L B; Rúa, J; Ferrero, M A; García-Armesto, M R
The present work was aimed at characterizing 12 strains of lactic acid bacteria (LAB) to obtain improved potential starter or probiotic cultures that could be used for making dairy products from ewe's milk and cow's milk. Eight strains with antimicrobial properties, isolated from ewe's milk and from cheese made from ewe's and/or cow's milk, were studied. They were identified as Enterococcus faecalis (five strains), Lactococcus lactis subsp. cremoris, Leuconostoc mesenteroides, and Lactobacillus paracasei subsp. paracasei (one strain of each species). Additionally, four strains were obtained from the American Type Culture Collection: Lactobacillus casei 393 (isolated from cheese), L. lactis subsp. lactis 11454 (origin nonspecified and a producer of nisin), and two strains isolated from human feces (L. paracasei subsp. paracasei 27092 and Lactobacillus rhamnosus 53103, antibacterial agent producer). All E. faecalis strains showed at least one virulence factor (either hemolysin or gelatinase), which emphasizes the importance of these studies in this species. Both L. lactis strains and most Lactobacillus spp. were good acidifiers in ewe's milk and cow's milk at 30°C. High β-galactosidase activity, as well as aminopeptidase activities that favor the development of desirable flavors in cheese, were detected in all Lactobacillus spp. strains. Furthermore, L. rhamnosus ATCC 53103 showed α-fucosidase activity (thought to help colonization of the intestine) and lack of α-glucosidase activity (a trait considered positive for diabetic and obese humans). This last enzymatic activity was also lacking in L. lactis ATCC 11454. L. mesenteroides was the only strain D(2)-lactic acid producer. The selection of any particular strain for probiotic or dairy cultures should be performed according to the technological and/or functional abilities needed.
Torriani, Sandra; Zapparoli, Giacomo; Dellaglio, Franco
Two PCR-based methods, specific PCR and randomly amplified polymorphic DNA PCR (RAPD-PCR), were used for rapid and reliable differentiation of Lactobacillus delbrueckii subsp. bulgaricus and L. delbrueckii subsp. lactis. PCR with a single combination of primers which targeted the proline iminopeptidase (pepIP) gene of L. delbrueckii subsp. bulgaricus allowed amplification of genomic fragments specific for the two subspecies when either DNA from a single colony or cells extracted from dairy products were used. A numerical analysis of the RAPD-PCR patterns obtained with primer M13 gave results that were consistent with the results of specific PCR for all strains except L. delbrueckii subsp. delbrueckii LMG 6412T, which clustered with L. delbrueckii subsp. lactis strains. In addition, RAPD-PCR performed with primer 1254 provided highly polymorphic profiles and thus was superior for distinguishing individual L. delbrueckii strains. PMID:10508059
den Bakker, Henk C; Manuel, Clyde S; Fortes, Esther D; Wiedmann, Martin; Nightingale, Kendra K
Twenty Listeria-like isolates were obtained from environmental samples collected on a cattle ranch in northern Colorado; all of these isolates were found to share an identical partial sigB sequence, suggesting close relatedness. The isolates were similar to members of the genus Listeria in that they were Gram-stain-positive, short rods, oxidase-negative and catalase-positive; the isolates were similar to Listeria fleischmannii because they were non-motile at 25 °C. 16S rRNA gene sequencing for representative isolates and whole genome sequencing for one isolate was performed. The genome of the type strain of Listeria fleischmannii (strain LU2006-1(T)) was also sequenced. The draft genomes were very similar in size and the average MUMmer nucleotide identity across 91% of the genomes was 95.16%. Genome sequence data were used to design primers for a six-gene multi-locus sequence analysis (MLSA) scheme. Phylogenies based on (i) the near-complete 16S rRNA gene, (ii) 31 core genes and (iii) six housekeeping genes illustrated the close relationship of these Listeria-like isolates to Listeria fleischmannii LU2006-1(T). Sufficient genetic divergence of the Listeria-like isolates from the type strain of Listeria fleischmannii and differing phenotypic characteristics warrant these isolates to be classified as members of a distinct infraspecific taxon, for which the name Listeria fleischmannii subsp. coloradonensis subsp. nov. is proposed. The type strain is TTU M1-001(T) ( =BAA-2414(T) =DSM 25391(T)). The isolates of Listeria fleischmannii subsp. coloradonensis subsp. nov. differ from the nominate subspecies by the inability to utilize melezitose, turanose and sucrose, and the ability to utilize inositol. The results also demonstrate the utility of whole genome sequencing to facilitate identification of novel taxa within a well-described genus. The genomes of both subspecies of Listeria fleischmannii contained putative enhancin genes; the Listeria fleischmannii subsp
Lee, Dong Hwan; Kim, Jin-Beom; Lim, Jeong-A; Han, Sang-Wook; Heu, Sunggi
The plant pathogenic bacterial genus Pectobacteirum consists of heterogeneous strains. The P. carotovorum species is a complex strain showing divergent characteristics, and a new subspecies named P. carotovorum subsp. brasiliensis has been identified recently. In this paper, we re-identified the P. carotovorum subsp. brasiliensis isolates from those classified under the subspecies carotovorum and newly isolated P. carotovorum subsp. brasiliensis strains. All isolates were able to produce plant cell-wall degrading enzymes such as pectate lyase, polygalacturonase, cellulase and protease. We used genetic and biochemical methods to examine the diversity of P. carotovorum subsp. brasiliensis isolates, and found genetic diversity within the brasiliensis subsp. isolates in Korea. The restriction fragment length polymorphism analysis based on the recA gene revealed a unique pattern for the brasiliensis subspecies. The Korean brasiliensis subsp. isolates were divided into four clades based on pulsed-field gel electrophoresis. However, correlations between clades and isolated hosts or year could not be found, suggesting that diverse brasiliensis subsp. isolates existed. PMID:25288994
Lambe, D W; Moroz, D A
The agglutination technique was used to establish a serological classification scheme for 98 strains of Bacteroides fragilis subsp. fragilis isolated from clinical specimens and normal human feces. Absorbed antisera were prepared to seven strains of B. fragilis subsp. fragilis. These seven absorbed antisera were species as well as subspecies specific and provided the basis of the serological classification scheme. This scheme was composed of 21 serogroups; seven of these serogroups contained only one group component. There was a total of 45 serological patterns. This serological scheme may be used for the serological classification of strains of B. fragilis subsp. fragilis and to study the epidemiology of this organism. PMID:950378
Martínez-Rodríguez, Julia del C.; la Mora-Amutio, Marcela De; Plascencia-Correa, Luis A.; Audelo-Regalado, Esmeralda; Guardado, Francisco R.; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J.; Escalante, Adelfo; Beltrán-García, Miguel J.; Ogura, Tetsuya
Agave tequilana Weber var. ‘Azul’ is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost. PMID:25763038
Martínez-Rodríguez, Julia del C; De la Mora-Amutio, Marcela; Plascencia-Correa, Luis A; Audelo-Regalado, Esmeralda; Guardado, Francisco R; Hernández-Sánchez, Elías; Peña-Ramírez, Yuri J; Escalante, Adelfo; Beltrán-García, Miguel J; Ogura, Tetsuya
Agave tequilana Weber var. 'Azul' is grown for the production of tequila, inulin and syrup. Diverse bacteria inhabit plant tissues and play a crucial role for plant health and growth. In this study culturable endophytic bacteria were extracted from leaf bases of 100 healthy Agave tequilana plants. In plant tissue bacteria occurred at mean population densities of 3 million CFU/g of fresh plant tissue. Three hundred endophytic strains were isolated and 16s rDNA sequences grouped the bacteria into eight different taxa that shared high homology with other known sequences. Bacterial endophytes were identified as Acinectobacter sp., A. baumanii, A. bereziniae, Cronobacter sakazakii, Enterobacter hormaechei, Bacillus sp. Klebsiella oxytoca, Pseudomonas sp., Enterococcus casseliflavus, Leuconostoc mesenteroides subsp. mesenteroides and Gluconobacter oxydans. Isolates were confirmed to be plant growth promoting bacteria (PGPB) by their capacities for nitrogen fixation, auxin production, phosphate solubilization, or antagonism against Fusarium oxysporum AC132. E. casseliflavus JM47 and K. oxytoca JM26 secreted the highest concentrations of IAA. The endophyte Acinectobacter sp. JM58 exhibited the maximum values for nitrogen fixation and phosphate solubilization index (PSI). Inhibition of fungi was found in Pseudomonas sp. JM9p and K. oxytoca JM26. Bacterial endophytes show promise for use as bio-inoculants for agave cultivation. Use of endophytes to enhance cultivation of agave may be particularly important for plants produced by micropropagation techniques, where native endophytes may have been lost.
Ishida, Nobuhiro; Suzuki, Tomiko; Tokuhiro, Kenro; Nagamori, Eiji; Onishi, Toru; Saitoh, Satoshi; Kitamoto, Katsuhiko; Takahashi, Haruo
Poly D-lactic acid is an important polymer because it improves the thermostability of poly L-lactic acid by the stereo complex formation. We constructed a metabolically engineered Saccharomyces cerevisiae that produces D-lactic acid efficiently. In this recombinant, the coding region of pyruvate decarboxylase 1 (PDC1) was completely deleted, and two copies of the D-lactate dehydrogenase (D-LDH) gene from Leuconostoc mesenteroides subsp. mesenteroides strain NBRC3426 were introduced into the genome. The D-lactate production reached 61.5 g/l, the amount of glucose being transformed into D-lactic acid being 61.2% under neutralizing conditions. Additionally, the yield of free D-lactic acid was also shown to be 53.0% under non-neutralizing conditions. It was confirmed that D-lactic acid of extremely high optical purity of 99.9% or higher. Our finding obtained the possibility of a new approach for pure d-lactic acid production without a neutralizing process compared with other techniques involving lactic acid bacteria and transgenic Escherichia coli.
Baek, Seung-Ho; Kwon, Eunice Y; Kim, Yong Hwan; Hahn, Ji-Sook
There is an increasing demand for microbial production of lactic acid (LA) as a monomer of biodegradable poly lactic acid (PLA). Both optical isomers, D-LA and L-LA, are required to produce stereocomplex PLA with improved properties. In this study, we developed Saccharomyces cerevisiae strains for efficient production of D-LA. D-LA production was achieved by expressing highly stereospecific D-lactate dehydrogenase gene (ldhA, LEUM_1756) from Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 in S. cerevisiae lacking natural LA production activity. D-LA consumption after glucose depletion was inhibited by deleting DLD1 encoding D-lactate dehydrogenase and JEN1 encoding monocarboxylate transporter. In addition, ethanol production was reduced by deleting PDC1 and ADH1 genes encoding major pyruvate decarboxylase and alcohol dehydrogenase, respectively, and glycerol production was eliminated by deleting GPD1 and GPD2 genes encoding glycerol-3-phosphate dehydrogenase. LA tolerance of the engineered D-LA-producing strain was enhanced by adaptive evolution and overexpression of HAA1 encoding a transcriptional activator involved in weak acid stress response, resulting in effective D-LA production up to 48.9 g/L without neutralization. In a flask fed-batch fermentation under neutralizing condition, our evolved strain produced 112.0 g/L D-LA with a yield of 0.80 g/g glucose and a productivity of 2.2 g/(L · h).
Backus, Lennart; Boekhorst, Jos; Dijkstra, Annereinou; Beerthuyzen, Marke; Siezen, Roland J.; Bachmann, Herwig; van Hijum, Sacha A. F. T.
ABSTRACT The lactic acid bacterium Lactococcus lactis is widely used for the fermentation of dairy products. Here, we present the draft genome sequences of 11 L. lactis subsp. cremoris strains isolated from different environments. PMID:28302789
Bollet, C; Grimont, P; Gainnier, M; Geissler, A; Sainty, J M; De Micco, P
Serratia proteamaculans subsp. quinovora was isolated from several samples (blood cultures, tracheal aspirates, pleural effusion) from a patient with pneumonia. This is the first clinical isolate and the first documented human infection caused by this organism. PMID:8432835
Harris, N. Beth; Barletta, Raúl G.
Mycobacterium avium subsp. paratuberculosis (basonym M. paratuberculosis) is the etiologic agent of a severe gastroenteritis in ruminants known as Johne's disease. Economic losses to the cattle industry in the United States are staggering, reaching $1.5 billion annually. A potential pathogenic role in humans in the etiology of Crohn's disease is under investigation. In this article, we review the epidemiology, pathogenesis, diagnostics, and disease control measures of this important veterinary pathogen. We emphasize molecular genetic aspects including the description of markers used for strain identification, diagnostics, and phylogenetic analysis. Recent important advances in the development of animal models and genetic systems to study M. paratuberculosis virulence determinants are also discussed. We conclude with proposals for the applications of these models and recombinant technology to the development of diagnostic, control, and therapeutic measures. PMID:11432810
Zachariah, Sherin; Kumari, Prabla; Das, Subrata K
Two closely related aerobic, Gram reaction-negative rod-shaped bacteria (S7-75(T) and S7-80) were isolated from mucus of coral Fungia seychellensis from Andaman Sea, India. Heterotrophic growth on marine agar was observed at 4-35 °C and pH 6.5-10.5; optimum growth occurred at 25-30 °C and pH 7-8. 16 S rRNA sequence analysis confirmed the strains belonged to the genus Sulfitobacter and the two isolates shared more than 99.28% pairwise sequence similarity. DNA-DNA similarity between two isolates S7-75(T) and S7-80 was above 96%. Strain S7-75(T) showed maximum 16S rRNA similarity of 99.64% with Sulfitobacter pontiacus LMG 19752(T). However, DNA-DNA relatedness between strain S7-75(T) and S. pontiacus LMG 19752(T) confirmed the placement of strain S7-75(T) as subspecies under the species S. pontiacus. Further, pulsed-field gel electrophoresis (PFGE), REP-PCR, ERIC-PCR fingerprint patterns and lipid profiles also differentiated strain S7-75(T) from the reference strain of S. pontiacus LMG 19752(T). The DNA G+C content was 59.8 mol%. Q10 was the major respiratory quinone. Based on polyphasic analysis, the isolate S7-75(T) represents a subspecies of S. pontiacus for which the name S. pontiacus subsp. fungiae subsp. nov. is proposed with S7-75(T) (=JCM 31094(T) = LMG 29158(T)) as type strain.
Description of Klebsiella quasipneumoniae sp. nov., isolated from human infections, with two subspecies, Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and Klebsiella quasipneumoniae subsp. similipneumoniae subsp. nov., and demonstration that Klebsiella singaporensis is a junior heterotypic synonym of Klebsiella variicola.
Brisse, Sylvain; Passet, Virginie; Grimont, Patrick A D
Strains previously classified as members of Klebsiella pneumoniae phylogroups KpI, KpII-A, KpII-B and KpIII were characterized by 16S rRNA (rrs) gene sequencing, multilocus sequence analysis based on rpoB, fusA, gapA, gyrA and leuS genes, average nucleotide identity and biochemical characteristics. Phylogenetic analysis demonstrated that KpI and KpIII corresponded to K. pneumoniae and Klebsiella variicola, respectively, whereas KpII-A and KpII-B formed two well-demarcated sequence clusters distinct from other members of the genus Klebsiella. Average nucleotide identity between KpII-A and KpII-B was 96.4 %, whereas values lower than 94 % were obtained for both groups when compared with K. pneumoniae and K. variicola. Biochemical properties differentiated KpII-A, KpII-B, K. pneumoniae and K. variicola, with acid production from adonitol and l-sorbose and ability to use 3-phenylproprionate, 5-keto-d-gluconate and tricarballylic acid as sole carbon sources being particularly useful. Based on their genetic and phenotypic characteristics, we propose the names Klebsiella quasipneumoniae subsp. quasipneumoniae subsp. nov. and K. quasipneumoniae subsp. similipneumoniae subsp. nov. for strains of KpII-A and KpII-B, respectively. The type strain of K. quasipneumoniae sp. nov. and of K. quasipneumoniae subsp. quasipneumoniae subsp. nov. is 01A030(T) ( = SB11(T) = CIP 110771(T) = DSM 28211(T)). The type strain of K. quasipneumoniae subsp. similipneumoniae subsp. nov. is 07A044(T) ( = SB30(T) = CIP 110770(T) = DSM 28212(T)). Both strains were isolated from human blood cultures. This work also showed that Klebsiella singaporensis is a junior heterotypic synonym of K. variicola.
Thyssen, A; Grisez, L; van Houdt, R; Ollevier, F
The taxonomic position of Photobacterium damselae subsp. piscicida, the causative agent of fish pasteurellosis, is controversial as this organism has also been described as 'Pasteurella piscicida'. To clarify the taxonomic position of the pathogen, a total of 113 P. damselae subsp. piscicida strains and 20 P. damselae subsp. damselae strains, isolated from different geographical areas and from the main affected fish species, were analysed using 129 morphological and biochemical tests, including the commercial API 20E and API CH50 test systems. For comparison, the type strains of other Photobacterium species (i.e. Photobacterium leiognathi and Photobacterium angustum) were included in the analyses. The results were statistically analysed by unweighted pair group average clustering and the distance between the different clusters was expressed as the percentage disagreement. The analyses showed that, based on morphological and biochemical identification tests, P. damselae subsp. piscicida is related to other Photobacterium species. However, it is clearly distinguishable from P. damselae subsp. damselae and no phenotypic evidence was found to include P. damselae subsp. piscicida as a subspecies in the species P. damselae.
Hunt Gerardo, Sharon; Citron, Diane M.; Claros, Marina C.; Fernandez, Helen T.; Goldstein, Ellie J. C.
Pasteurella multocida is composed of three subspecies that are often differentiated by fermentation of sorbitol and dulcitol. We studied 35 dulcitol-negative P. multocida isolates from infected dog and cat bite wounds, 16 of which yielded weak and/or conflicting fermentation reactions in Andrades sorbitol, thus making it difficult to distinguish between the two dulcitol-negative subspecies of P. multocida, i.e., P. multocida subsp. multocida and P. multocida subsp. septica. All isolates and two control strains were further analyzed using a PCR fingerprinting technique with a single primer (M13 core) and assessed for α-glucosidase (α-Glu) activity. Although the PCR fingerprint patterns and α-Glu activity did not correlate well with the sorbitol fermentation reactions, they did correlate well with each other. All strains identified as P. multocida subsp. septica were positive for α-Glu activity and exhibited the group I PCR fingerprint profile. All strains categorized as P. multocida subsp. multocida displayed either the group II or group III PCR fingerprint profile; 9 of 11 of these isolates were α-Glu negative. These data suggest that both PCR fingerprinting and α-Glu activity provide reliable means for differentiating P. multocida subsp. multocida from P. multocida subsp. septica, particularly in strains that produce weak and/or discrepant sorbitol fermentation reactions. PMID:11427568
Mannitol, formed mainly by Leuconostoc mesenteroides bacteria, is a sensitive marker of sugarcane and sugarbeet deterioration that can predict multiple processing problems. The delivery of consignments of deteriorated sugarcane or sugar beets to factories can detrimentally affect multiple process u...
Mannitol, formed mainly by Leuconostoc mesenteroides bacteria, is a sensitive marker of sugarcane and sugarbeet deterioration that can predict multiple processing problems. The delivery of consignments of deteriorated sugarcane or sugar beets to factories can detrimentally affect multiple process un...
Exopolysaccharide production by micro-organisms have several industrial applications in food, pharmaceuticals, or other industries. Lactic acid bacteria such as Leuconostoc mesenteroides (LM) are endemic to the environment and produce extracellular polymeric glucans such as dextran. Dextrans cause s...
Vela, Ana I.; Falsen, Enevold; Simarro, Isabel; Rollan, Eduardo; Collins, Matthew D.; Domínguez, Lucas; Fernandez-Garayzabal, Jose F.
We report a case of bacteremia in puppies caused by Streptococcus dysgalactiae subsp. dysgalactiae. Identification was achieved by phenotypic and molecular genetic methods. This is the first report of the recovery of S. dysgalactiae subsp. dysgalactiae from dogs. PMID:16455943
Oliveira, Luciana M.; Resende, Daniela M.; Dorneles, Elaine M. S.; Horácio, Elvira C. A.; Alves, Fernanda L.; Gonçalves, Leilane O.; Tavares, Grace S.; Stynen, Ana Paula R.; Lage, Andrey P.
Campylobacter fetus subsp. fetus is a zoonotic bacterium important for animal and public health. The complete sequencing and annotation of the genome of the type strain C. fetus subsp. fetus ATCC 27374 are reported here. PMID:27979934
Oliveira, Luciana M; Resende, Daniela M; Dorneles, Elaine M S; Horácio, Elvira C A; Alves, Fernanda L; Gonçalves, Leilane O; Tavares, Grace S; Stynen, Ana Paula R; Lage, Andrey P; Ruiz, Jeronimo C
Campylobacter fetus subsp. fetus is a zoonotic bacterium important for animal and public health. The complete sequencing and annotation of the genome of the type strain C. fetus subsp. fetus ATCC 27374 are reported here.
Javed, R.; Taku, A. K.; Gangil, Rakhi; Sharma, R. K.
Aim: The aim was to determine the occurrence of streptococci in equines in Jammu (R. S. Pura, Katra), characterization of Streptococci equi subsp. equi and Streptococcus equi subsp. zooepidemicus with respect to their virulence traits and to determine antibiotic sensitivity pattern of virulent Streptococcus isolates. Materials and Methods: A total of 96 samples were collected from both clinically affected animals (exhibiting signs of respiratory tract disease) and apparently healthy animals and were sent to laboratory. The organisms were isolated on Columbia nalidixic acid agar containing 5% sheep blood as well as on sheep blood agar and confirmed by cultural characteristics and biochemical tests. Molecular detection of Streptococcus was done directly from cultures using sodA and seM gene-based polymerase chain reaction (PCR). Antibiogram was performed against five antibiotics such as amoxicillin, penicillin G, streptomycin, rifampicin, and methicillin. Results: During this study, a total 40 streptococcal isolates were obtained out of which 2 isolates were of S. equi subsp. equi, 12 isolates were from S. equi subsp. zooepidemicus. In the PCR-based detection, we revealed amplicons of 235 bp and 679 bp for confirmation of sodA and seM gene, respectively. In antibiogram, two isolates of S. equi subsp. equi were found resistant to penicillin G, and all other isolates were found sensitive to amoxicillin and streptomycin. Conclusion: The majority of streptococcal infections was due to S. equi subsp. Zooepidemicus, and thus was recognized as a potential pathogen of diseases of equines besides S. equi subsp. equi. PMID:27651677
Soto, Esteban; Halliday-Wimmonds, Iona; Francis , Stewart; Kearney, Michael T; Hansen, John D.
Francisella noatunensis subsp. orientalis (Fno) is an emergent fish pathogen in both marine and fresh water environments. The bacterium is suspected to persist in the environment even without the presence of a suitable fish host. In the present study, the influence of different abiotic factors such as salinity and temperature were used to study the biofilm formation of different isolates of Fno including intracellular growth loci C (iglC)and pathogenicity determinant protein A (pdpA) knockout strains. Finally, we compared the susceptibility of planktonic and biofilm to three disinfectants used in the aquaculture and ornamental fish industry, namely Virkon®, bleach and hydrogen peroxide. The data indicates that Fno is capable of producing biofilms within 24 h where both salinity as well as temperature plays a role in the growth and biofilm formation of Fno. Mutations in theiglC or pdpA, both known virulence factors, do not appear to affect the capacity of Fno to produce biofilms, and the minimum inhibitory concentration, and minimum biocidal concentration for the three disinfectants were lower than the minimum biofilm eradication concentration values. This information needs to be taken into account if trying to eradicate the pathogen from aquaculture facilities or aquariums.
Cross-reactivity of mycobacterial antigens in immune-based diagnostic assays has been a major concern and criticism of current tests for the detection of paratuberculosis. In the present study, host immune responses to antigen preparations of Mycobacterium avium subsp. paratuberculosis (MAP), consis...
Stalheim, O H; Proctor, S J
Two pregnant cows aborted 11 and 18 days after Mycoplasma agalactiae subsp bovis was inoculated into the amniotic fluids. The placentas were retained. The fetuses (approx 100 and 150 days of age) were decomposed; M agalactiae subsp bovis was recovered from several tissues of the fetuses, the placentas, and fetal fluids. The same organism was given by intraperitoneal injection to 2 other pregnant (130 and 180 days, respectively) cows. At necropsy of the latter 36 days later, placentitis was severe; M agalactiae subsp bovis was recovered from the placentas of both cows and from the fetus of 1 cow. Control cows given sterile mycoplasma cultural medium by intraamnion or intraperitoneal injection did not abort and were not infected. When first recovered from the bovine placenta and fetus, M agalactiae subsp bovis grew slowly in liquid medium and assumed bizarre colonial morphology on solidified medium. Colonies were small (0.1 to 0.5 mm) and dark and lacked halos, but they reacted specifically in the direct fluorescent antibody test with equine M agalactiae subsp bovis antiserum. After 1 or 2 subcultures, the isolates grew at a normal rate and displayed their usual colonial morphology.
Dumke, Jessika; Hinse, Dennis; Vollmer, Tanja; Schulz, Jochen; Knabbe, Cornelius; Dreier, Jens
Streptococcus gallolyticus subsp. gallolyticus (S. gallolyticus subsp. gallolyticus), a member of group D streptococci, is an inhabitant of the animal and human gastrointestinal tract. Furthermore, it is a facultative pathogen which causes e.g. endocarditis, septicemia and mastitis. S. gallolyticus subsp. gallolyticus may be transmitted either directly or indirectly between animals and humans. However, the transmission routes are an unsolved issue. In this study, we present systematic analyses of an S. gallolyticus subsp. gallolyticus isolate of an infective endocarditis patient in relation to isolates of his laying hen flock. Isolates from pooled droppings of laying hens, pooled dust samples and human blood culture were characterized by using multilocus sequence typing (MLST) and DNA fingerprinting. MLST revealed the same allelic profile of isolates from the human blood culture and from the droppings of laying hens. In addition, these isolates showed clonal identity regarding a similar DNA fingerprinting pattern. For the first time, we received a hint that transmission of S. gallolyticus subsp. gallolyticus between poultry and humans may occur. This raises the question about the zoonotic potential of isolates from poultry and should be considered in future studies. PMID:25978355
Gul-Guven, Reyhan; Guven, Kemal; Poli, Annarita; Nicolaus, Barbara
A new thermophilic spore-forming strain KG8(T) was isolated from the mud of Taslidere hot spring in Batman. Strain KG8(T) was aerobe, Gram-positive, rod-shaped, motile, occurring in pairs or filamentous. Growth was observed from 35-65 degrees C (optimum 55 degrees C) and at pH 5.5-9.5 (optimum pH 7.5). It was capable of utilizing starch, growth was observed until 3% NaCl (w/v) and it was positive for nitrate reduction. On the basis of 16S rRNA gene sequence similarity, strain KG8(T) was shown to be related most closely to Anoxybacillus species. Chemotaxonomic data (major isoprenoid quinone-menaquinone-7; major fatty acid-iso-C15:0 and iso-C17:0) supported the affiliation of strain KG8(T) to the genus Anoxybacillus. The results of DNA-DNA hybridization, physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain KG8(T). Based on these results we propose assigning a novel subspecies of Anoxybacillus kamchatkensis, to be named Anoxybacillus kamchatkensis subsp. asaccharedens subsp. nov. with the type strain KG8(T) (DSM 18475(T)=CIP 109280(T)).
Eker, İsmail; Yıldırım, Hasan; Altıoğlu, Yusuf
Abstract A new subpecies, Tulipa cinnabarina subsp. toprakii subsp. nov. (Liliaceae) from Turkey is described. Diagnostic characters, descriptions, detailed illustrations, geographical distribution, conservation status and ecological observations on the new taxon are provided. It is also compared with the closely related Tulipa cinnabarina subsp. cinnabarina. PMID:27698585
Chitwood, M Colter; Maggi, Ricardo G; Kennedy-Stoskopf, Suzanne; Toliver, Marcée; DePerno, Christopher S
Bartonella vinsonii subsp. berkhoffii has not been detected previously in white-tailed deer (Odocoileus virginianus). We tested whole blood from 60 white-tailed deer for Bartonella spp. DNA; three (5%) were positive for Bartonella vinsonii subsp. berkhoffii. This is the first detection of Bartonella vinsonii subsp. berkhoffii in white-tailed deer.
Eker, İsmail; Yıldırım, Hasan; Altıoğlu, Yusuf
A new subpecies, Tulipa cinnabarina subsp. toprakii subsp. nov. (Liliaceae) from Turkey is described. Diagnostic characters, descriptions, detailed illustrations, geographical distribution, conservation status and ecological observations on the new taxon are provided. It is also compared with the closely related Tulipa cinnabarina subsp. cinnabarina.
Place, Raymond B; Hiestand, Daniel; Gallmann, Hans Rudolf; Teuber, Michael
Two staphylococcal strains, RP29T and RP33, were isolated from the main microflora of a surface ripened Swiss mountain cheese made from raw milk. These two strains were differentiated from the most closely related species Staphylococcus equorum on the basis of DNA-DNA hybridisation and phenotypic characteristics and are proposed as Staphylococcus equorum subsp. linens subsp. nov. They could be distinguished phenotypically from S. equorum by their sensitivity to all 14 tested antibiotics, especially to novobiocin, their incapability to ferment alpha-D-lactose, maltose, sucrose, D-trehalose, D-xylose, L-arabinose, salicin, D-ribose, D-raffinose, D-mannitol, and D-alanine. The GenBank accession numbers for the reference sequences of the 16S rDNA and the hsp60 gene used in this study are AF527483 and AF527484, respectively. 30 tons of a semi-hard Swiss cheese were produced with Staphylococcus equorum subsp. linens DSM 15097T as starter culture component in addition to Debaryomyces hansenii, Geotrichum candidum, Brevibacterium linens, Corynebacterium casei for surface ripened cheeses. The products were sensorically and hygienically perfect. Therefore, Staphylococcus equorum subsp. linens DSM 15097T can be proposed as starter culture component for surface ripened cheeses without any detected antibiotic resistances. The type strain of Staphylococcus equorum subsp. linens is DSM 15097T (CIP 107656T).
Tóth, Tímea; Lakatos, Tamás; Koltay, András
Seven Gram-negative bacterial strains were isolated from oozing bark canker of poplar (Populus × euramericana) trees in Hungary. They showed high (>98.3%) 16S rRNA gene sequence similarity to Lonsdalea quercina; however, they differed from this species in several phenotypic characteristics. Multilocus sequence analysis based on three housekeeping genes (gyrB, atpD and infB) revealed, and DNA-DNA hybridization analysis confirmed, that this group of bacterial strains forms a distinct lineage within the species Lonsdalea quercina. A detailed study of phenotypic and physiological characteristics confirmed the separation of isolates from poplars from other subspecies of L. quercina; therefore, a novel subspecies, Lonsdalea quercina subsp. populi, type strain NY060(T) (=DSM 25466(T)=NCAIM B 02483(T)), is proposed.
Tamas, Ivica; Dedysh, Svetlana N.; Liesack, Werner; Stott, Matthew B.; Alam, Maqsudul; Murrell, J. Colin; Dunfield, Peter F.
Beijerinckia indica subsp. indica is an aerobic, acidophilic, exopolysaccharide-producing, N2-fixing soil bacterium. It is a generalist chemoorganotroph that is phylogenetically closely related to facultative and obligate methanotrophs of the genera Methylocella and Methylocapsa. Here we report the full genome sequence of this bacterium. PMID:20601475
Vähäkuopus, Susanna; Vuopio-Varkila, Jaana; Vuento, Risto; Syrjänen, Jaana
We conducted a retrospective population-based study of 140 episodes of Streptococcus dysgalactiae subsp. equisimilis bacteremia occurring in Finland during 1995–2004. Rare emm types were associated with more severe disease and increased mortality rates. Skin and soft tissue infections were more frequent clinical signs among cases caused by common emm types. PMID:20409380
Rantala, Sari; Vahakuopus, Susanna; Vuopio-Varkila, Jaana; Vuento, Risto; Syrjanen, Jaana
We conducted a retrospective population-based study of 140 episodes of Streptococcus dysgalactiae subsp. equisimilis bacteremia occurring in Finland during 1995-2004. Rare emm types were associated with more severe disease and increased mortality rates. Skin and soft tissue infections were more frequent clinical signs among cases caused by common emm types.
Cockwill, Ken R.; Taylor, Susan M.; Philibert, Helene M.; Breitschwerdt, Edward B.; Maggi, Ricardo G.
A dog referred for lameness was diagnosed with culture-negative endocarditis. Antibodies to Bartonella spp. were detected. Antibiotic treatment resulted in transient clinical improvement, but the dog developed cardiac failure and was euthanized. Bartonella vinsonii subsp. berkhoffii genotype IV was identified within the aortic heart valve lesions by PCR amplification and DNA sequencing. PMID:17824328
Cai, Jin; Feng, Jia; Xie, Shulian; Wang, Feipeng; Xu, Qiufeng
Bacterial ring rot of potato is one of the most serious potato plant and tuber diseases. Laminaria japonica extract was investigated for its antimicrobial activity against Clavibater michiganense subsp. sepedonicum (Spieckermann & Kotthoff) Davis et al., the causative agent of bacterial ring rot of potato. The results showed that the optimum extraction conditions of antimicrobial substances from L. japonica were an extraction temperature of 80°C, an extraction time of 12 h, and a solid to liquid ratio of 1∶25. Active compounds of L. japonica were isolated by solvent partition, thin layer chromatography (TLC) and column chromatography. All nineteen fractionations had antimicrobial activities against C. michiganense subsp. sepedonicum, while Fractionation three (Fr.3) had the highest (P<0.05) antimicrobial activity. Chemical composition analysis identified a total of 26 components in Fr.3. The main constituents of Fr.3 were alkanes (80.97%), esters (5.24%), acids (4.87%) and alcohols (2.21%). Antimicrobial activity of Fr.3 against C. michiganense subsp. sepedonicum could be attributed to its ability to damage the cell wall and cell membrane, induce the production of reactive oxygen species (ROS), increase cytosolic Ca2+ concentration, inhibit the glycolytic pathway (EMP) and tricarboxylic acid (TCA) cycle, inhibit protein and nucleic acid synthesis, and disrupt the normal cycle of DNA replication. These findings indicate that L. japonica extracts have potential for inhibiting C. michiganense subsp. sepedonicum. PMID:24714388
Svec, P; Sedlácek, I
A group of nine presumptive enterococci was isolated on enterococcal selective media Slanetz-Bartley agar and/or kanamycin-esculin-azide agar during a screening of Enterococcus spp. in surface waters. All strains formed a homogeneous cluster separated from all enterococcal species using rep-PCR fingerprinting with the (GTG)5 primer but they matched fingerprints revealed by Lactococcus lactis subsp. lactis representatives. Further identification using extensive biotyping and automated ribotyping with EcoRI (RiboPrinter microbial characterization system) confirmed all strains as L. lactis subsp. lactis in full correspondence with the (GTG)5-PCR. We demonstrated that L. lactis subsp. lactis strains occur in different surface waters and can be confused with enterococci due to their positive growth on selective enterococcal media as well as positive results in tests commonly used for identification of the genus Enterococcus (esculin hydrolysis, acetoin and pyrrolidonyl arylamidase production, growth at 10 degrees C and in 6.5% NaCl). The (GTG)5-PCR fingerprinting was revealed as a reliable and fast method for the identification of L. lactis subsp lactis while automated ribotyping with EcoRI proved to be a good tool for intrasubspecies typing purposes.
Ti, Hui-Hui; Lin, Li-Dong; Ding, Wen-Bing; Wei, Xiao-Yi
Further investigation on the stems of Artocarpus nitidus subsp. lingnanensis led to the isolation and characterization of a new flavan-3-ol, named artoflavanocoumarin, along with three known compounds (+)-catechin, (+)-afzelechin 3-O-α-L-rhamnoside, and (+)-catechin 3-O-α-L-rhamnoside. Their structures were elucidated on the basis of spectroscopic data.
Young, Andrea; Levine, Seth J.; Garvin, Joseph P.; Brown, Susan; Turner, Lauren; Fritzinger, Angela; Gertz, Robert E.; Murphy, Julia M.; Vogt, Marshall; Beall, Bernard
Streptococcus equi subsp. zooepidemicus is a known zoonotic pathogen. In this public health investigation conducted in Virginia, USA, in 2013, we identified a probable family cluster of S. zooepidemicus cases linked epidemiologically and genetically to infected guinea pigs. S. zooepidemicus infections should be considered in patients who have severe clinical illness and report guinea pig exposure. PMID:25531424
An accession of Syringa oblata subsp. oblata (PI 23031) collected in China by Frank Meyer in 1908was given the name ‘Frank Meyer’ by Father Fiala in 1988. To be established according to the International Code of Nomenclature for Cultivated Plants, a new cultivar name must be accompanied by a descrip...
Hiery, Eva; Poetsch, Ansgar; Moosbauer, Tanja; Amin, Bushra; Hofmann, Jörg; Burkovski, Andreas
Clavibacter michiganensis, subsp. michiganensis is a Gram-positive plant pathogen infecting tomato (Solanum lycopersicum). Despite a considerable economic importance due to significant losses of infected plants and fruits, knowledge about virulence factors of C. michiganensis subsp. michiganensis and host-pathogen interactions on a molecular level are rather limited. In the study presented here, the proteome of culture supernatants from C. michiganensis subsp. michiganensis NCPPB382 was analyzed. In total, 1872 proteins were identified in M9 and 1766 proteins in xylem mimicking medium. Filtration of supernatants before protein precipitation reduced these to 1276 proteins in M9 and 976 proteins in the xylem mimicking medium culture filtrate. The results obtained indicate that C. michiganensis subsp. michiganensis reacts to a sucrose- and glucose-depleted medium similar to the xylem sap by utilizing amino acids and host cell polymers as well as their degradation products, mainly peptides, amino acids and various C5 and C6 sugars. Interestingly, the bacterium expresses the previously described virulence factors Pat-1 and CelA not exclusively after host cell contact in planta but already in M9 minimal and xylem mimicking medium. PMID:28248277
The study of host immune responses to Mycobacterium avium subsp. paratuberculosis (MAP) is complicated by a number of factors, including the protracted nature of the disease and the stealthy nature of the pathogen. Noted as one of the more fastidious mycobacteria, infection with MAP is often chara...
Mycobacterium avium subsp. paratuberculosis (MAP) infection in ruminants leads to a chronic and progressive enteric disease (Johne’s disease) that results in loss of intestinal function, poor body condition, and eventual death. Transmission is primarily through a fecal-oral route in neonates but con...
Parsons, Sandra K.; Bull, C. Michael; Gordon, David M.
Multilocus sequence typing of 56 Salmonella enterica subsp. enterica strains isolated from Australian wildlife hosts was performed. The results of population assignment algorithms revealed that the 56 strains could be subdivided into two distinct clades. Strains belonging to the two clades were further distinguished phenotypically, genotypically, and with respect to host distribution. PMID:21378038
Clavibacter michiganensis subsp. insidiosus (Cmi) causes bacterial wilt disease of alfalfa (Medicago sativa L.) and can also infect the model legume plant M. truncatula. The virulence mechanisms of Cmi are yet to be identified, hampered by the lack of efficient mutagenesis tools as well as by the la...
Mikalová, Lenka; Bosák, Juraj; Hříbková, Hana; Dědičová, Daniela; Benada, Oldřich; Šmarda, Jan; Šmajs, David
Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family.
Hříbková, Hana; Dědičová, Daniela; Benada, Oldřich; Šmarda, Jan; Šmajs, David
Forty strains of Salmonella enterica (S. enterica) subspecies salamae (II), arizonae (IIIa), diarizonae (IIIb), and houtenae (IV) were isolated from human or environmental samples and tested for bacteriophage production. Production of bacteriophages was observed in 15 S. enterica strains (37.5%) belonging to either the subspecies salamae (8 strains) or diarizonae (7 strains). Activity of phages was tested against 52 pathogenic S. enterica subsp. enterica isolates and showed that phages produced by subsp. salamae had broader activity against pathogenic salmonellae compared to phages from the subsp. diarizonae. All 15 phages were analyzed using PCR amplification of phage-specific regions and 9 different amplification profiles were identified. Five phages (SEN1, SEN4, SEN5, SEN22, and SEN34) were completely sequenced and classified as temperate phages. Phages SEN4 and SEN5 were genetically identical, thus representing a single phage type (i.e. SEN4/5). SEN1 and SEN4/5 fit into the group of P2-like phages, while the SEN22 phage showed sequence relatedness to P22-like phages. Interestingly, while phage SEN34 was genetically distantly related to Lambda-like phages (Siphoviridae), it had the morphology of the Myoviridae family. Based on sequence analysis and electron microscopy, phages SEN1 and SEN4/5 were members of the Myoviridae family and phage SEN22 belonged to the Podoviridae family. PMID:28118395
Yang, En; Fan, Lihua; Jiang, Yueming; Doucette, Craig; Fillmore, Sherry
The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity.LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated.Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods.
The biopreservation of foods using bacteriocinogenic lactic acid bacteria (LAB) isolated directly from foods is an innovative approach. The objectives of this study were to isolate and identify bacteriocinogenic LAB from various cheeses and yogurts and evaluate their antimicrobial effects on selected spoilage and pathogenic microorganisms in vitro as well as on a food commodity. LAB were isolated using MRS and M17 media. The agar diffusion bioassay was used to screen for bacteriocin or bacteriocin-like substances (BLS) producing LAB using Lactobacillus sakei and Listeria innocua as indicator organisms. Out of 138 LAB isolates, 28 were found to inhibit these bacteria and were identified as strains of Enterococcus faecium, Streptococcus thermophilus, Lactobacillus casei and Lactobacillus sakei subsp. sakei using 16S rRNA gene sequencing. Eight isolates were tested for antimicrobial activity at 5°C and 20°C against L. innocua, Escherichia coli, Bacillus cereus, Pseudomonas fluorescens, Erwinia carotovora, and Leuconostoc mesenteroides subsp. mesenteroides using the agar diffusion bioassay, and also against Penicillium expansum, Botrytis cinerea and Monilinia frucitcola using the microdilution plate method. The effect of selected LAB strains on L. innocua inoculated onto fresh-cut onions was also investigated. Twenty percent of our isolates produced BLS inhibiting the growth of L. innocua and/or Lact. sakei. Organic acids and/or H2O2 produced by LAB and not the BLS had strong antimicrobial effects on all microorganisms tested with the exception of E. coli. Ent. faecium, Strep. thermophilus and Lact. casei effectively inhibited the growth of natural microflora and L. innocua inoculated onto fresh-cut onions. Bacteriocinogenic LAB present in cheeses and yogurts may have potential to be used as biopreservatives in foods. PMID:22963659
Yuan, Kat (Xiaoli); Cullis, Jeff; Lévesque, C. André; Chen, Wen; Lewis, Christopher T.; De Boer, Solke H.
Pectobacterium carotovurum subsp. brasiliense causes soft rot and blackleg diseases on potato. Here, we report the draft genome sequences of three weakly virulent P. carotovurum subsp. brasiliense strains isolated in Canada. Analysis of these genome sequences will help to pinpoint differences in virulence among P. carotovurum subsp. brasiliense strains from tropical/subtropical and temperate regions, such as Canada and United States. A small number of key factors for adaptation to this bacterium's specific environmental niche were also evaluated. PMID:25858837
Zheng, Jie; Ayers, Sherry; Melka, David C.; Curry, Phillip E.; Payne, Justin S.; Laasri, Anna; Wang, Charles; Hammack, Thomas S.; Brown, Eric W.
A quantitative real-time PCR (qPCR) designed to detect Salmonella enterica subsp. enterica serovar Enteritidis, targeting the sdf gene, generated positive results for S. enterica subsp. enterica serovar Typhimurium (CFSAN033950) and S. enterica subsp. enterica serovar Nottingham (CFSAN006803) isolated from food samples. Both strains show pulsed-field gel electrophoresis (PFGE) patterns distinct from those of S. Enteritidis. Here, we report the genome sequences of these two strains. PMID:27445384
Gueimonde, Miguel; Flórez, Ana Belén; van Hoek, Angela H. A. M.; Stuer-Lauridsen, Birgitte; Strøman, Per; de los Reyes-Gavilán, Clara G.; Margolles, Abelardo
All strains of Bifidobacterium animalis subsp. lactis described to date show medium level resistance to tetracycline. Screening of 26 strains from a variety of sources revealed the presence of tet(W) in all isolates. A transposase gene upstream of tet(W) was found in all strains, and both genes were cotranscribed in strain IPLAIC4. Mutants with increased tetracycline resistance as well as tetracycline-sensitive mutants of IPLAIC4 were isolated and genetically characterized. The native tet(W) gene was able to restore the resistance phenotype to a mutant with an alteration in tet(W) by functional complementation, indicating that tet(W) is necessary and sufficient for the tetracycline resistance seen in B. animalis subsp. lactis. PMID:20348299
Dragoeva, Asya; Stoyanova, Zheni; Koleva, Vanya; Dragolova, Daniela
Nepeta nuda subsp. nuda is a medicinal plant growing wild in Bulgaria. Different species of Nepeta genus have been reported to possess allelopathic potential. The present study was conducted to observe its phytotoxic effects on T. aestivum and C. sativus L. seeds in laboratory conditions. Nepeta water extracts (NWE) prepared from aerial parts of plants at concentrations 2, 4, 6, 8, 10, 12 and 14 g/l were tested. The rate of seed germination, the root and shoot length, fresh and dry weight of seedlings were observed after treatment with NWE. As a control served seeds treated with distilled water. Germination was not affected, but NWE showed deterioration in seedling growth. Roots were more affected than shoots. The fresh and dry weights were reduced upon treatment with the extracts tested. These negative effects were dose-dependent. The overall results indicate presence of water soluble allelochemicals in Nepeta nuda subsp. nuda.
Butot, Sophie; Jagadeesan, Balamurugan; Bakker, Douwe; Donaghy, John
ABSTRACT The efficiency of direct steam injection (DSI) at 105°C for 3 s to inactivate Mycobacterium avium subsp. paratuberculosis in milk at a pilot-plant scale was investigated. Milk samples were artificially contaminated with M. avium subsp. paratuberculosis and also with cow fecal material naturally infected with M. avium subsp. paratuberculosis. We also tested milk artificially contaminated with Mycobacterium smegmatis as a candidate surrogate to compare thermal inactivation between M. smegmatis and M. avium subsp. paratuberculosis. Following the DSI process, no viable M. avium subsp. paratuberculosis or M. smegmatis was recovered using culture methods for both strains. For pure M. avium subsp. paratuberculosis cultures, a minimum reduction of 5.6 log10 was achieved with DSI, and a minimum reduction of 5.7 log10 was found with M. smegmatis. The minimum log10 reduction for wild-type M. avium subsp. paratuberculosis naturally present in feces was 3.3. In addition, 44 dairy and nondairy powdered infant formula (PIF) ingredients used during the manufacturing process of PIF were tested for an alternate source for M. avium subsp. paratuberculosis and were found to be negative by quantitative PCR (qPCR). In conclusion, the results obtained from this study indicate that a >7-fold-log10 reduction of M. avium subsp. paratuberculosis in milk can be achieved with the applied DSI process. IMPORTANCE M. avium subsp. paratuberculosis is widespread in dairy herds in many countries. M. avium subsp. paratuberculosis is the causative agent of Johne's disease in cattle, and infected animals can directly or indirectly (i.e., fecal contamination) contaminate milk. Despite much research and debate, there is no conclusive evidence that M. avium subsp. paratuberculosis is a zoonotic bacterium, i.e., one that causes disease in humans. The presence of M. avium subsp. paratuberculosis or its DNA has been reported in dairy products, including pasteurized milk, cheese, and infant formula
Darrasse, A; Kotoujansky, A; Bertheau, Y
Erwinia carotovora subsp. atroseptica is a pathogen of potatoes in Europe because of its ability to induce blackleg symptoms early in the growing season. However, E. carotovora subsp. carotovora is not able to produce such severe symptoms under the same conditions. On the basis of the technique described by Straus and Ausubel (Proc. Natl. Acad. Sci. USA 87:1889-1893, 1990), we isolated DNA sequences of E. carotovora subsp. atroseptica 86.20 that were absent from the genomic DNA of E. carotovora subsp. carotovora CH26. Six DNA fragments ranging from ca. 180 to 400 bp were isolated, cloned, and sequenced. Each fragment was further hybridized with 130 microorganisms including 87 E. carotovora strains. One probe was specific for typical E. carotovora subsp. atroseptica strains, two probes hybridized with all E. carotovora subsp. atroseptica strains and with a few E. carotovora subsp. carotovora strains, and two probes recognized only a subset of E. carotovora subsp. atroseptica strains. The last probe was absent from the genomic DNA of E. carotovora subsp. carotovora CH26 but was present in the genomes of many strains, including those of other species and genera. This probe is homologous to the putP gene of Escherichia coli, which encodes a proline carrier. Further use of the probes is discussed. Images PMID:8117082
Streptococcus equi subsp. zooepidemicus is an important cause of infectious diseases in horses and rarely humans. Little is known about the virulence factors or protective antigens of S. equi subsp. zooepidemicus. In the present study, I designed original primers based on an alignment of the gene sagp(arcA) from Streptococcus pyogenes encoding streptococcal acid glycoprotein-arginine deiminase (SAGP/AD) to amplify the S. equi subsp. zooepidemicus counterpart sequence by polymerase chain reaction, and I analyzed the sagp(arcA) gene of the organism. Using chromosomal walking steps, I identified a contiguous eight-gene locus involved in SAGP/AD production. Their open reading frames were found to share significant homologies and to correspond closely in molecular mass to previously sequenced arc genes of S. pyogenes, thus they were designated ahrC.2 (arginine repressor), arcR (CRP/FNR transcription regulator), sagp(arcA) (streptococcal acid glycoprotein-arginine deiminase), putative acetyltransferase gene, arcB (ornithine carbamyl transferase), arcD (arginine-ornithine antiporter), arcT (Xaa-His peptidase), and arcC (carbamate kinase). The SAGP homologue of S. equi subsp. zooepidemicus (SzSAGP), encoded by arcA gene of the bacteria (arcA(SZ)), was successfully expressed in Escherichia coli and purified to homogeneity. When in vitro growth inhibitory activity of the recombinant SzSAGP was tested against MOLT-3 cells, it inhibited the growth of the cells during the 3 days of culture in a dose-dependent manner, accompanied by the induction of apoptotic cell death. The recombinant protein also possessed AD activity. By immunoblot analysis using both anti-SzSAGP-SfbI(H8) and anti-SfbI(H8) sera, I was able to demonstrate that the SzSAGP protein is expressed on the streptococcal surface.
Toy, Nurten; Özogul, Fatih; Özogul, Yesim
The function of cell-free solutions (CFSs) of lactic acid bacteria (LAB) on tyramine and other biogenic amine production by different food borne-pathogens (FBPs) was investigated in tyrosine decarboxylase broth (TDB) using HPLC. Cell free solutions were prepared from four LAB strains. Two different concentrations which were 50% (5 ml CFS+5 ml medium/1:1) and 25% (2.5 ml CFS+7.5 ml medium/1:3) CFS and the control without CFS were prepared. Both concentration of CFS of Streptococcus thermophilus and 50% CFS of Pediococcus acidophilus inhibited tyramine production up to 98% by Salmonella paratyphi A. Tyramine production by Escherichia coli was also inhibited by 50% CFS of Lactococcus lactis subsp. lactis and 25% CFS of Leuconostoc lactis. subsp. cremoris. The inhibitor effect of 50% CFS of P. acidophilus was the highest on tyramine production (55%) by Listeria monocytogenes, following Lc. lactis subsp. lactis and Leuconostoc mesenteroides subsp. cremoris (20%) whilst 25% CFS of Leu. mes. subsp. cremoris and Lc. lactis subsp. lactis showed stimulator effects (160%). The stimulation effects of 50% CFS of S. thermophilus and Lc. lactis subsp. lactis were more than 70% by Staphylococcus aureus comparing to the control. CFS of LAB strains showed statistically inhibitor effect since lactic acid inhibited microbial growth, decreased pH quickly and reduced the formation of AMN and BAs. Consequently, in order to avoid the formation of high concentrations of biogenic amines in fermented food by bacteria, it is advisable to use CFS for food and food products.
Harasawa, Ryô; Fujita, Hiromi; Kadosaka, Teruki; Ando, Shuji; Rikihisa, Yasuko
Mycoplasma haemomuris is causative of infectious anaemia or splenomegaly in rodents. We examined the nucleotide sequences of the non-ribosomal genes, rnpB and dnaK, in strains of the species M. haemomuris detected in small field mice and black rats. rnpB nucleotide sequences in strains of the species M. haemomuris isolated from small field mice and black rats had only 89 % sequence similarity, suggesting their separation into two distinct subgroups. dnaK had a nucleotide sequence similarity of 84 % between the subgroups. These results support the classification of M. haemomuris into two genetically distinct subgroups. Here we propose the establishment of these subgroups as 'Candidatus Mycoplasma haemomuris subsp. musculi', detected in small field mice (Apodemus argenteus), and 'Candidatus Mycoplasma haemomuris subsp. ratti', detected in black rats (Rattus rattus).
Igimi, S; Takahashi, E; Mitsuoka, T
A new subspecies, Staphylococcus schleiferi subsp. coagulans, was isolated from the external auditory meatus of dogs suffering from external ear otitis and is described on the basis of studies of 21 strains. Phenotypic studies showed that these strains are more closely related to Staphylococcus intermedius than to other staphylococci, but DNA hybridization studies indicated that they are closely related to Staphylococcus schleiferi N850274T. On the basis of biochemical distinctiveness (positive test tube coagulase test and different carbohydrate reactions) and the etiological importance (frequent isolation from otitis specimens from dogs) of these strains, we propose to classify them as a subspecies of S. schleiferi. The strains of this new subspecies are coagulase tube test, beta-hemolysin, and heat-stable nuclease positive but clumping factor negative. A simple scheme for the differentiation of S. schleiferi subsp. coagulans from the other coagulase-positive staphylococci is presented. The type strain is GA211 (= JCM 7470).
Pollard, Dominic J; Young, Joanna C; Covarelli, Valentina; Herrera-León, Silvia; Connor, Thomas R; Fookes, Maria; Walker, Danielle; Echeita, Aurora; Thomson, Nicholas R; Berger, Cedric N; Frankel, Gad
Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs. Though several key S Typhimurium effector genes are missing (e.g., avrA, sopB, and sseL), S. enterica subsp. salamae invades HeLa cells and contains homologues of S. bongori sboK and sboC, which we named seoC SboC and SeoC are homologues of EspJ from enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), which inhibit Src kinase-dependent phagocytosis by ADP-ribosylation. By screening 73 clinical and environmental Salmonella isolates, we identified EspJ homologues in S. bongori, S. enterica subsp. salamae, and Salmonella enterica subsp. arizonae The β-lactamase TEM-1 reporter system showed that SeoC is translocated by the SPI-1 T3SS. All the Salmonella SeoC/SboC homologues ADP-ribosylate Src E310 in vitro Ectopic expression of SeoC/SboC inhibited phagocytosis of IgG-opsonized beads into Cos-7 cells stably expressing green fluorescent protein (GFP)-FcγRIIa. Concurrently, S. enterica subsp. salamae infection of J774.A1 macrophages inhibited phagocytosis of beads, in a seoC-dependent manner. These results show that S. bongori, S. enterica subsp. salamae, and S. enterica subsp. arizonae share features of the infection strategy of extracellular pathogens EPEC and EHEC and shed light on the complexities of the T3SS effector repertoires of Enterobacteriaceae.
Beaulieu, Julien; Jean, Martine; Belzile, François
Arabidopsis lyrata, a close relative of the model plant Arabidopsis thaliana, is 1 of a few plant species for which the genome is to be entirely sequenced, which promises to yield important insights into genome evolution. Only 2 sparse linkage maps have been published, and these were based solely on markers derived from the A. thaliana genome. Because the genome of A. lyrata is practically twice as large as that of A. thaliana, the extent of map coverage of the A. lyrata genome remains uncertain. In this study, a 2-way pseudo-testcross strategy was used to construct genetic linkage maps of A. lyrata subsp. petraea and A. lyrata subsp. lyrata, using simple sequence repeat (SSR) and cleaved amplified polymorphic sequence (CAPS) markers from the A. thaliana genome, and anonymous amplified fragment length polymorphism (AFLP) markers that could potentially uncover regions unique to the A. lyrata genome. The SSR and CAPS markers largely confirmed the relationships between linkage groups in A. lyrata and A. thaliana. AFLP markers slightly increased the coverage of the A. lyrata maps, but mostly increased marker density on the linkage groups. We noted a much lower level of polymorphism and a greater segregation distortion in A. lyrata subsp. lyrata markers. The implications of these findings for the sequencing of the A. lyrata genome are discussed.
Renois, Fanny; Jacques, Jérôme; Guillard, Thomas; Moret, Hélène; Pluot, Michel; Andreoletti, Laurent; de Champs, Christophe
In the present study, we comparatively assessed the pathophysiological mechanisms developed during lung infection of BALB/C female mice infected by an original wild type Klebsiella pneumoniae subsp. ozaenae strain (CH137) or by a referent subspecies K. pneumoniae. subsp. pneumoniae strain (ATCC10031). The mice infected with 2.10⁶ CFU K. p. subsp. pneumoniae (n = 10) showed transient signs of infection and all of them recovered. All of those infected with 1.10⁶ CFU K. p. subsp. ozaenae (n = 10) developed pneumonia within 24 h and died between 48 and 72 h. Few macrophages, numerous polymorphonuclear cells and lymphocytes were observed in their lungs in opposite to K. p. subsp. pneumoniae. In bronchoalveolar lavage, a significant increase in MIP-2, IL-6, KC and MCP-1 levels was only observed in K. p. subsp. ozaenae infected mice whereas high levels of TNF-α were evidenced with the two subspecies. Our findings indicated a lethal effect of a wild type K. p. subsp. ozaenae strain by acute pneumonia reflecting an insufficient alveolar macrophage response. This model might be of a major interest to comparatively explore the pathogenicity of K. p. subsp ozaenae strains and to further explore the physiopathological mechanisms of gram-negative bacteria induced human pneumonia.
Aslam, Fozia; Thomas, Torsten
Klebsiella quasipneumoniae subsp. similipneumoniae MB373 was isolated from effluent of the Hattar Industrial Estate, Haripur, Pakistan. K. quasipneumoniae subsp. similipneumoniae has few cultivated/characterized members so far. Whole-genome sequencing revealed its potential for metal and toxin resistance, which further elucidated various enzymatic processes for the degradation of xenobiotics, illuminating its bioremediation applications. PMID:27688323
Liu, Wing-Yee; Chung, Karl Ming-Kar; Wong, Chi-Fat; Jiang, Jing-Wei; Hui, Raymond Kin-Hi
Enterobacter cloacae subsp. cloacae strain ENHKU01 is a Gram-negative endophyte isolated from a diseased pepper (Capsicum annuum) plant in Hong Kong. This is the first complete genome sequence report of a plant-endophytic strain of E. cloacae subsp. cloacae. PMID:23045485
There is no known antibody that detects M. avium subsp paratuberculosis and does not cross react with other M. avium subspecies. In the present study, a monoclonal antibody was identified from mice immunized with a cell membrane fraction of M. avium subsp paratuberculosis strain K-10. This antibod...
Yee, Emma; Bono, James L.; Rijnsburger, Martine; Campero, Carlos; Wagenaar, Jaap A.; Duim, Birgitta
Campylobacter fetus subsp. venerealis bv. intermedius is a variant of C. fetus subsp. venerealis, the causative agent of bovine genital campylobacteriosis, a venereal disease associated with abortion and infertility in cattle. We report the first closed whole-genome sequence of this biovar. PMID:24503995
Mycobacterium avium subsp paratuberculosis is the etiologic agent of Johne’s disease. We report the draft genome sequences of six M. avium subsp paratuberculosis isolates obtained from diverse hosts including bison, cattle and sheep. These sequences will deepen our understanding of host association ...
Ghazal, Shimaa; Oshone, Rediet; Simpson, Stephen; Morris, Krystalynne; Abebe-Akele, Feseha; Thomas, W. Kelley; Khalil, Kamal M.
Photorhabdus luminescens subsp. laumondii HP88 is an entomopathogenic bacterium that forms a symbiotic association with Heterorhabditis nematodes. We report here a 5.27-Mbp draft genome sequence for P. luminescens subsp. laumondii HP88, with a G+C content of 42.4% and containing 4,243 candidate protein-coding genes. PMID:26988056
Stynen, Ana Paula Reinato; Lage, Andrey Pereira; Moore, Robert J.; Rezende, Antonio Mauro; de Resende, Vivian D'Afonseca da Silva; Ruy, Patricia de Cássia; Daher, Nesley; Resende, Daniela de Melo; de Almeida, Sintia Silva; Soares, Siomar de Castro; de Abreu, Vinicius Augusto Carvalho; Rocha, Aryane Aparecida C. Magalhães; dos Santos, Anderson Rodrigues; Barbosa, Eudes Guilherme Vieira; Costa, Danielle Fonseca; Dorella, Fernanda Alves; Miyoshi, Anderson; de Lima, Alex Ranieri Jerônimo; Campos, Frederico Davi da Silva; de Sá, Pablo Gomes; Lopes, Thiago Souza; Rodrigues, Ryan Mauricio Araujo; Carneiro, Adriana Ribeiro; Leão, Thiago; Cerdeira, Louise Teixeira; Ramos, Rommel Thiago Jucá; Silva, Artur; Azevedo, Vasco; Ruiz, Jerônimo C.
Campylobacter fetus subsp. venerealis is the etiologic agent of bovine genital campylobacteriosis, a sexually transmitted disease of cattle that is of worldwide importance. The complete sequencing and annotation of the genome of the type strain C. fetus subsp. venerealis NCTC 10354T are reported. PMID:21952544
Huynh, Steven; Heikema, Astrid P.
ABSTRACT Campylobacter jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of C. jejuni subsp. jejuni HS:19 Penner reference strain RM3420. PMID:28232429
Du, Yuhui; Song, Lifu; Feng, Wenjing; Pei, Guangsheng; Zheng, Ping; Yu, Zhichao; Sun, Jibin
Lactococcus lactis subsp. lactis strain YF11 is a food preservative bacterium with a high capacity to produce nisin. Here, we announce the draft genome sequence of Lactococcus lactis subsp. lactis YF11 (2,527,433 bp with a G+C content of 34.81%). PMID:23929487
Shahina, P M; Nampy, Santhosh
The pantropical genus Enicostema (Gentianaceae) has three species and two sub species world over, namely, E. verticillatum (L.) Engl. (America), E. elizabethae Veldkamp (Madagascar) and E. axillare having 3 subsp. viz., subsp. axillare (Lam.) A. Raynal (India), subsp. latilobum (N.E. Br.) A. Raynal (East Africa) and subsp. littorale (Blume) A. Raynal (Indonesia). The present study aims to delimit the Indian taxa based on field and herbarium studies. Comparative morphology is studied using live as well as consulting wide range of specimens housed at various herbaria. The anatomy of leaf, stem, and root is studied using free hand sections and from epidermal peelings. The seed and pollen morphology are studied under SEM. Information on anatomy, palynology and seed micromorphology of E. axillare subsp. axillare is provided for the first time.
Yao, Kuan; Muruvanda, Tim; Roberts, Richard J.; Payne, Justin; Allard, Marc W.
Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791). PMID:26988049
Yao, Kuan; Muruvanda, Tim; Roberts, Richard J; Payne, Justin; Allard, Marc W; Hoffmann, Maria
Salmonella enterica spp. are pathogenic bacteria commonly associated with food-borne outbreaks in human and animals. Salmonella enterica spp. are characterized into more than 2,500 different serotypes, which makes epidemiological surveillance and outbreak control more difficult. In this report, we announce the first complete genome and methylome sequences from two Salmonella type strains associated with food-borne outbreaks, Salmonella enterica subsp. enterica serovar Panama (ATCC 7378) and Salmonella enterica subsp. enterica serovar Sloterdijk (ATCC 15791).
Draft Genome Sequences of Three Pectobacterium Strains Causing Blackleg of Potato: P. carotovorum subsp. brasiliensis ICMP 19477, P. atrosepticum ICMP 1526, and P. carotovorum subsp. carotovorum UGC32
Fiers, Mark W. E. J.; Lu, Ashley; Armstrong, Karen F.
Blackleg is a disease caused by several species of Pectobacterium that results in losses to potato crops worldwide. Here, we report the draft genomes of three taxonomically and geographically distinct blackleg-causing strains of Pectobacterium: P. carotovorum subsp. brasiliensis ICMP 19477, P. atrosepticum ICMP 1526, and P. carotovorum subsp. carotovorum UGC32. Comparison of these genomes will support the identification of common traits associated with their capacity to cause blackleg. PMID:26251497
Hunt, H V; Ansell, S W; Russell, S J; Schneider, H; Vogel, J C
Asplenium fontanum subsp. fontanum and A. petrarchae subsp. bivalens are diploid rock ferns of limestone outcrops of the western Mediterranean region. Asplenium fontanum subsp. fontanum occurs from Valencia through northeastern Spain to the Alpes-Maritimes and Swiss Jura. Asplenium petrarchae subsp. bivalens occurs only on Majorca, in Valencia and possibly in southern Spain. We analysed allozyme and chloroplast genetic marker diversity in 75 populations of A. fontanum subsp. fontanum and 12 populations of A. petrarchae subsp. bivalens sampled from across their respective ranges. The two species show similar levels of species and population genetic diversity to one another and to other diploid European Asplenium taxa. Both are predominantly outbreeding, as indicated by F(IS) = 0.108 and 0.167 respectively. Substantial between-population differentiation results largely from differentiation between regions. Isolation by distance operates over limited geographic ranges, up to 50 km. In A. fontanum subsp. fontanum, the major geographical differentiation between Valencia and the rest of the taxon range probably represents an ancient range fragmentation. A less pronounced differentiation divides populations in the SW from those in the NE of the range, with evidence for a biogeographic link between the eastern Pyrenees and southeastern France. High diversity in the Pyrenees may either represent ancient population differentiation, or a suture zone. In A. petrarchae subsp. bivalens, populations on Majorca exhibit a subset of the genetic diversity present in Valencia, although the two regions are strongly differentiated by differing allele frequencies. Dispersal from the mainland may have founded Majorcan populations, although a role for in situ island survival cannot be excluded.
Draft Genome Sequences of Three Pectobacterium Strains Causing Blackleg of Potato: P. carotovorum subsp. brasiliensis ICMP 19477, P. atrosepticum ICMP 1526, and P. carotovorum subsp. carotovorum UGC32.
Panda, Preetinanda; Fiers, Mark W E J; Lu, Ashley; Armstrong, Karen F; Pitman, Andrew R
Blackleg is a disease caused by several species of Pectobacterium that results in losses to potato crops worldwide. Here, we report the draft genomes of three taxonomically and geographically distinct blackleg-causing strains of Pectobacterium: P. carotovorum subsp. brasiliensis ICMP 19477, P. atrosepticum ICMP 1526, and P. carotovorum subsp. carotovorum UGC32. Comparison of these genomes will support the identification of common traits associated with their capacity to cause blackleg.
Analysis by gas chromatography-mass spectrometry of the volatiles from the fruits of Ammodaucus leucotrichus subsp. leucotrichus and subsp. nanocarpus grown in North Africa and the Canary Islands, respectively.
Velasco-Negueruela, A; Pérez-Alonso, M J; Pérez de Paz, P L; Palá-Paúl, J; Sanz, J
The volatiles from the fruits of Ammodaucus leucotrichus subsp. leucotrichus and subsp. nanocarpus (two endemic species, the first from North Africa and the second from the Canary Islands, Spain) were studied by gas chromatography and gas chromatography-mass spectrometry. The major components of the volatiles of subsp. nanocarpus were found to be, beta-pinene (22.2-33.6%), bornyl angelate (20.6-21.8%) and camphor (8.3-11.7%) whereas in the fruits of subsp. leucotrichus, the main constituents were perillaldehyde (63.6%) and limonene (26.8%). We also suggest that subsp. nanocarpus should have the status of species and should be named Ammodaucus nanocarpus.
Tkachuk, Victoria L.; Krause, Denis O.; McAllister, Tim A.; Buckley, Katherine E.; Reuter, Tim; Hendrick, Steve
Mycobacterium avium subsp. paratuberculosis causes Johne's disease (JD) in ruminants, with substantial economic impacts on the cattle industry. Johne's disease is known for its long latency period, and difficulties in diagnosis are due to insensitivities of current detection methods. Eradication is challenging as M. avium subsp. paratuberculosis can survive for extended periods within the environment, resulting in new infections in naïve animals (W. Xu et al., J. Environ. Qual. 38:437-450, 2009). This study explored the use of a biosecure, static composting structure to inactivate M. avium subsp. paratuberculosis. Mycobacterium smegmatis was also assessed as a surrogate for M. avium subsp. paratuberculosis. Two structures were constructed to hold three cattle carcasses each. Naturally infected tissues and ground beef inoculated with laboratory-cultured M. avium subsp. paratuberculosis and M. smegmatis were placed in nylon and plastic bags to determine effects of temperature and compost environment on viability over 250 days. After removal, samples were cultured and growth of both organisms was assessed after 12 weeks. After 250 days, M. avium subsp. paratuberculosis was still detectable by PCR, while M. smegmatis was not detected after 67 days of composting. Furthermore, M. avium subsp. paratuberculosis remained viable in both implanted nylon and plastic bags over the composting period. As the compost never reached a homogenous thermophilic (55 to 65°C) state throughout each structure, an in vitro experiment was conducted to examine viability of M. avium subsp. paratuberculosis after exposure to 80°C for 90 days. Naturally infected lymph tissues were mixed with and without compost. After 90 days, M. avium subsp. paratuberculosis remained viable despite exposure to temperatures typically higher than that achieved in compost. In conclusion, it is unlikely composting can be used as a means of inactivating M. avium subsp. paratuberculosis associated with cattle
McNeilly, Celia L.; McMillan, David J.
Streptococcus dysgalactiae subsp. equisimilis (SDSE) is a human pathogen that colonizes the skin or throat, and causes a range of diseases from relatively benign pharyngitis to potentially fatal invasive diseases. While not as virulent as the close relative Streptococcus pyogenes the two share a number of virulence factors and are known to coexist in a human host. Both pre- and post-genomic studies have revealed that horizontal gene transfer (HGT) and recombination occurs between these two organisms and plays a major role in shaping the population structure of SDSE. This review summarizes our current knowledge of HGT and recombination in the evolution of SDSE. PMID:25566202
Ti, Huihui; Wu, Ping; Lin, Lidong; Wei, Xiaoyi
The first stilbene possessing a γ-aminobutyric acid lactam function, artocarpene (1), and a new flavanone, 2-hydroxynaringenin 4'-O-β-d-glucopyranoside (2), were isolated from the stems of Artocarpus nitidus subsp. lingnanensis along with four known compounds, 2-hydroxynaringenin (3), oxyresveratrol (4), 3,4',5-trihydroxy-3'-prenylstilbene (5) and norartocarpetin (6). Their structures were elucidated on the basis of spectroscopic data. Compounds 1 exhibited weak antioxidant activity and 2 displayed weak cytotoxicity against human lung cancer A549 cell line.
Belhouchet, Zineddine; Sautour, Marc; Miyamoto, Tomofumi; Lacaille-Dubois, Marie-Aleth
Two new steroidal saponins (1, 2) were isolated from the roots of Smilax aspera subsp. mauritanica (POIR.) ARCANG. (Liliaceae), together with the known curillin G (3), asparagoside E (4), asparoside A (5), asparoside B (6) and the phenolic compound resveratrol (7). Their structures were established mainly on the basis of 600 MHz 2D-NMR spectral data. 3 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (minimum inhibitory concentrations of 25, 25 and 50 microg/ml, respectively) whereas the other compounds were inactive.
Relationship of Bacillus amyloliquefaciens clades associated with strains DSM 7T and FZB42T: a proposal for Bacillus amyloliquefaciens subsp. amyloliquefaciens subsp. nov. and Bacillus amyloliquefaciens subsp. plantarum subsp. nov. based on complete genome sequence comparisons.
Borriss, Rainer; Chen, Xiao-Hua; Rueckert, Christian; Blom, Jochen; Becker, Anke; Baumgarth, Birgit; Fan, Ben; Pukall, Rüdiger; Schumann, Peter; Spröer, Cathrin; Junge, Helmut; Vater, Joachim; Pühler, Alfred; Klenk, Hans-Peter
The whole-genome-sequenced rhizobacterium Bacillus amyloliquefaciens FZB42(T) (Chen et al., 2007) and other plant-associated strains of the genus Bacillus described as belonging to the species Bacillus amyloliquefaciens or Bacillus subtilis are used commercially to promote the growth and improve the health of crop plants. Previous investigations revealed that a group of strains represented a distinct ecotype related to B. amyloliquefaciens; however, the exact taxonomic position of this group remains elusive (Reva et al., 2004). In the present study, we demonstrated the ability of a group of Bacillus strains closely related to strain FZB42(T) to colonize Arabidopsis roots. On the basis of their phenotypic traits, the strains were similar to Bacillus amyloliquefaciens DSM 7(T) but differed considerably from this type strain in the DNA sequences of genes encoding 16S rRNA, gyrase subunit A (gyrA) and histidine kinase (cheA). Phylogenetic analysis performed with partial 16S rRNA, gyrA and cheA gene sequences revealed that the plant-associated strains of the genus Bacillus, including strain FZB42(T), formed a lineage, which could be distinguished from the cluster of strains closely related to B. amyloliquefaciens DSM 7(T). DNA-DNA hybridizations (DDH) performed with genomic DNA from strains DSM 7(T) and FZB42(T) yielded relatedness values of 63.7-71.2 %. Several methods of genomic analysis, such as direct whole-genome comparison, digital DDH and microarray-based comparative genomichybridization (M-CGH) were used as complementary tests. The group of plant-associated strains could be distinguished from strain DSM 7(T) and the type strain of B. subtilis by differences in the potential to synthesize non-ribosomal lipopeptides and polyketides. Based on the differences found in the marker gene sequences and the whole genomes of these strains, we propose two novel subspecies, designated B. amyloliquefaciens subsp. plantarum subsp. nov., with the type strain FZB42(T) ( = DSM
Nikolic, Milica; Terzic-Vidojevic, Amarela; Jovcic, Branko; Begovic, Jelena; Golic, Natasa; Topisirovic, Ljubisa
The Bukuljac cheese is traditionally homemade cheese, produced from heat-treated goat's milk without the addition of any bacterial starter culture. The presence of lactic acid bacteria (LAB) in Bukuljac cheese has been analyzed by using a polyphasic approach including microbiological and molecular methods such as rep-PCR with (GTG)5 primer. Lactobacillus paracasei subsp. paracasei represents a dominant strain in the microflora of analyzed cheese. Out of 55 Gram-positive and catalase-negative isolates, 48 belonged to L. paracasei subsp. paracasei species. Besides lactobacilli, five Lactococcus lactis subsp. lactis and two Enterococcus faecalis were found. Results of PCR-denaturing gradient gel electrophoresis (DGGE) of DNA extracted directly from the fresh cheese revealed the presence of Leuconostoc mesenteroides. Only lactobacilli showed a high proteolytic activity and hydrolyzed alpha(s1)- and beta-caseins. They are also producers of diacetyl. In addition, 34 out of 55 isolates, all determined as lactobacilli, showed the ability of auto-aggregation. Among 55 isolates, 50 also exhibited antimicrobial activity.
Praet, Jessy; Meeus, Ivan; Cnockaert, Margo; Houf, Kurt; Smagghe, Guy; Vandamme, Peter
Twelve isolates of lactic acid bacteria (LAB) were obtained in the course of a bumble bee gut microbiota study and grouped into four matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry clusters. Comparative 16S rRNA gene sequence analysis revealed that cluster 1 isolates, represented by strain LMG 28288(T), are most closely related to Lactobacillus apis (97.0% sequence similarity to that of L. apis LMG 26964(T)). Cluster 2 isolates represented by strain LMG 28290(T) are most closely related to Weissella hellenica (99.6% sequence similarity to that of W. hellenica LMG 15125(T)). The single cluster 3 and 4 isolates had identical 16S rRNA gene sequences which were 94.8% similar to that of Leuconostoc mesenteroides subsp. mesenteroides LMG 6893(T), their nearest phylogenetic neighbour. A polyphasic taxonomic study additionally including comparative pheS sequence analysis, DNA-DNA hybridization experiments, DNA G+C content analysis, (GTG)5-PCR fingerprinting and a biochemical characterization, demonstrated that cluster 1 isolates represent a novel Lactobacillus species for which we propose the name Lactobacillus bombicola sp. nov. with LMG 28288(T) (= DSM 28793(T)) as the type strain; and that cluster 2 isolates represent a novel Weissella species for which we propose the name Weissella bombi sp. nov. with LMG 28290(T) (= DSM 28794(T)) as the type strain. Cluster 3 and 4 isolates, in contrast, represented a very distinct, novel taxon that could be distinguished from members of the genera Leuconostoc and Fructobacillus, its nearest phylogenetic neighbours, by its cellular morphology, non-fructophilic metabolism and DNA G+C content. We therefore classify both isolates into a novel species representing a novel LAB genus for which the name Convivina intestini gen. nov., sp. nov. is proposed with LMG 28291(T) (= DSM 28795(T)) as the type strain.
Di Cagno, Raffaella; Surico, Rosalinda Fortunata; Minervini, Giovanna; Rizzello, Carlo Giuseppe; Lovino, Raffaella; Servili, Maurizio; Taticchi, Agnese; Urbani, Sefania; Gobbetti, Marco
Strains of Lactobacillus plantarum, Pediococcus acidilactici, Pediococcus pentosaceus and Leuconostoc mesenteroides subsp. mesenteroides were identified from 8 cultivars of sweet cherry by partial 16S rRNA gene sequence and subjected to typing by Random Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) analysis. Representative isolates from each species and each cultivar were screened based on the kinetics of growth on cherry puree added of (10%, v/v) stem infusion (CP-SI). A protocol for processing and storage of CP-SI, which included fermentation by selected autochthonous P. pentosaceus SWE5 and L. plantarum FP3 (started CP-SI) or spontaneous fermentation (unstarted CP-SI), was set up. Starters grew and remained viable at elevated cell numbers (ca. 9.0 log cfu g(-1)) during 60 days of storage at 4 °C. The number of presumptive lactic acid bacteria of the unstarted CP-SI did not exceed the value of ca. 3.0 log cfu g(-1). Consumption of carbohydrates (e.g., glucose and fructose) by starter lactic acid bacteria was limited as well as it was the lactic acid fermentation. Consumption of organic acids (e.g., malic acid) and free amino acids was evident, especially, throughout storage. Compared to CP-SI before processing, the concentrations of total phenolic compounds and anthocyanins did not vary in the started CP-SI. The concentration of anthocyanins slightly decreased in the unstarted CP-SI. The antioxidant activity, expressed as the scavenging activity toward DPPH radical, was found at highest level in the started CP-SI which approached that found in CP-SI before processing. During storage, viscosity and, especially, color indexes of started CP-SI were higher than those found in the unstarted CP-SI. Fermentation by autochthonous lactic acid bacteria seemed to also positively interfere with the sensory attributes of CP-SI.
Aguayo, Jaime; Adams, Gerard C; Halkett, Fabien; Catal, Mursel; Husson, Claude; Nagy, Zoltán Á; Hansen, Everett M; Marçais, Benoît; Frey, Pascal
Alder decline caused by Phytophthora alni has been one of the most important diseases of natural ecosystems in Europe during the last 20 years. The emergence of P. alni subsp. alni -the pathogen responsible for the epidemic-is linked to an interspecific hybridization event between two parental species: P. alni subsp. multiformis and P. alni subsp. uniformis. One of the parental species, P. alni subsp. uniformis, has been isolated in several European countries and, recently, in North America. The objective of this work was to assess the level of genetic diversity, the population genetic structure, and the putative reproduction mode and mating system of P. alni subsp. uniformis. Five new polymorphic microsatellite markers were used to contrast both geographical populations. The study comprised 71 isolates of P. alni subsp. uniformis collected from eight European countries and 10 locations in North America. Our results revealed strong differences between continental populations (Fst = 0.88; Rst = 0.74), with no evidence for gene flow. European isolates showed extremely low genetic diversity compared with the North American collection. Selfing appears to be the predominant mating system in both continental collections. The results suggest that the European P. alni subsp. uniformis population is most likely alien and derives from the introduction of a few individuals, whereas the North American population probably is an indigenous population.
Proposal to reclassify Brenneria quercina (Hildebrand and Schroth 1967) Hauben et al. 1999 into a new genus, Lonsdalea gen. nov., as Lonsdalea quercina comb. nov., descriptions of Lonsdalea quercina subsp. quercina comb. nov., Lonsdalea quercina subsp. iberica subsp. nov. and Lonsdalea quercina subsp. britannica subsp. nov., emendation of the description of the genus Brenneria, reclassification of Dickeya dieffenbachiae as Dickeya dadantii subsp. dieffenbachiae comb. nov., and emendation of the description of Dickeya dadantii.
Brady, Carrie L; Cleenwerck, Ilse; Denman, Sandra; Venter, Stephanus N; Rodríguez-Palenzuela, Pablo; Coutinho, Teresa A; De Vos, Paul
Bacterial isolates from oak trees in Spain and Britain, showing symptoms of bark canker and Acute Oak Decline (AOD), respectively, were examined by a polyphasic approach. Both 16S rRNA gene sequencing and multilocus sequence analysis (MLSA), based on partial sequences of gyrB, rpoB, infB and atpD genes, revealed that the isolates were separated into two genetic groups according to their origin. Their closest phylogenetic relative was Brenneria quercina, the causal agent of drippy nut disease of oak, which clustered distant to the other species of the genus Brenneria. MLSA data for species of the genera Brenneria, Pectobacterium, Dickeya, Erwinia, Pantoea and Samsonia confirmed the polyphyletic nature of the genus Brenneria and indicated synonymy of Dickeya dadantii and Dickeya dieffenbachiae. DNA-DNA hybridization experiments confirmed this synonymy and also revealed DNA-DNA relatedness values of 58-73% between the new oak isolates and B. quercina. Phenotypic and/or chemotaxonomic methods allowed B. quercina and the two genetic groups of new oak isolates to be discriminated from other recognized species of the genus Brenneria and from members of the closely related genera Dickeya, Pectobacterium and Samsonia. Based on the data obtained, the following taxonomic proposals are made: (1) reclassification of B. quercina as the type species of a novel genus, Lonsdalea gen. nov., as Lonsdalea quercina comb. nov. (type strain LMG 2724(T)=ATCC 29281(T)=CCUG 48867(T)=CFBP 3617(T)=CIP 105201(T)=DSM 4561(T)=ICMP 1845(T)), (2) classification of the oak isolates as Lonsdalea quercina subsp. iberica subsp. nov. (type strain LMG26264(T)=NCPPB 4490(T)) and Lonsdalea quercina subsp. britannica subsp. nov. (type strain LMG 26267(T)=NCPPB 4481(T)) and leading to the automatic creation of Lonsdalea quercina subsp. quercina subsp. nov. (type strain LMG 2724(T)=ATCC 29281(T)), (3) emendation of the description of the genus Brenneria, and (4) reclassification of Dickeya dieffenbachiae as
Cillara, Grazia; Manca, Maria Giovanna; Longheu, Carla; Tola, Sebastiana
In this study, the dihydrolipoyl dehydrogenase (lpdA) gene was used to distinguish Mycoplasma mycoides subsp. capri (Mmc) from Mycoplasma capricolum subsp. capricolum (Mcc), two of four Mycoplasma species that cause contagious agalactia in sheep and goats. After alignment of nucleotide sequences of both species, specific primer sets were designed from unchanging and variable gene segments. The first primer set LPD-C1-F/LPD-C1-R was used to amplify a 911 bp fragment that was subsequently co-digested with FastDigest PstI, SspI, EcoRI and ClaI enzymes. The PCR-RFLP profiles differentiated the two mycoplasma species. The second primer set was used to distinguish Mmc from Mcc by single tube PCR. Both methods were further applied to identify 54 isolates collected from dairy herds from different provinces in Sardinia. The results of this study showed that PCR-RFLP and PCR could be used in routine diagnosis for rapid and specific simultaneous discrimination of Mmc and Mcc.
Jeong, Do-Won; Kim, Hye-Rim; Han, Seulhwa; Jeon, Che Ok; Lee, Jong-Hoon
Twelve isolates from jeotgal, a Korean high-salt-fermented seafood, identified as Staphylococcus equorum were compared by phenotypic and genotypic methods to determine their precise taxonomic identities at the subspecies level. Four strains and three strains had complete 16S rRNA gene sequence matches with S. equorum subsp. equorum DSM 20674(T) and S. equorum subsp. linens DSM 15097(T), respectively. Five strains showed 99.9 % identity with the sequences of both type strains. In our DNA-DNA hybridization analyses among two type strains and two isolates, the similarities were over 72 % and were higher than the similarities presented at the subspecies proposal. Physiological characteristics such as sugar utilization, β-galactosidase activity, novobiocin resistance and salt tolerance, which were adopted for subspecies separation, could not be applied to assign the isolates to a taxonomic unit. Antibiotic susceptibility, hemolytic activity, biofilm formation and protein profiles did not present markers to divide the isolates into either of the subspecies. Multilocus sequence typing of the sequences of the 16S rRNA gene and five housekeeping genes did not produce any coherent relationship among the isolates and type strains. Repetitive element-PCR fingerprinting using ERIC (enterobacterial repetitive intergenic consensus) primers classified 12 isolates to three genotypes, and the genotypes of both type strains coincided with two isolates expressing different characteristics. Based on these phenotypic and genotypic analyses results, we propose to unify the present two subspecies of S. equorum into one species, S. equorum.
Schroll, G; Busse, H J; Parrer, G; Rölleke, S; Lubitz, W; Denner, E B
The authors have previously isolated a solvent tolerant bacterium, strain G(T), (T = type strain) capable to convert acetone-butanol bioprocess residues into poly-beta-hydroxybutyrate. Strain G(T) was initially identified as Alcaligenes spp by standard bacteriological tests. In this study the taxonomic position of the bacterium was investigated in detail. The 165 rDNA sequence analysis, the G + C content of DNA (56 mol%) and the presence of ubiquinone Q-8 confirmed strain G(T) as a representative of the genus Alcaligenes. In the polyamine pattern of the bacterium putrescine and cadaverine were detected, but only trace amounts of 2-hydroxyputrescine. The extremely low content of 2-hydroxyputrescine is remarkable, since this unique diamine is a common marker for beta-proteobacteria. Phylogenetic analyses of 16S rDNA demonstrated that Alcaligenes sp. G(T) is most closely related to the species Alcaligenes faecalis (99.6% sequence similarity to A. faecalis HR4 and 98.7% sequence similarity to A. faecalis [ATCC 8750T = DSM 30030T]. On the basis of DNA-DNA relatedness (56% similarity), the unique polyamine pattern, the physiological and biochemical differences strain G(T) could be distinguished from the species A. faecalis. Therefore, a new subspecies for the species Alcaligenes faecalis is proposed; Alcaligenes faecalis subsp. parafaecalis subsp. nov.
Rehfuss, Marc; Urban, James
A Gram (-) coccobacillary bacterium, J(T), was isolated from a graywater bioprocessor. 16S rRNA and biochemical analysis has revealed strain J(T) closely resembles Alcaligenes faecalis ATCC 8750T and A. faecalis subsp. parafaecalis DSM 13975T, but is a distinct, previously uncharacterized isolate. Strain J(T), along with the type strain of A. faecalis and its previously described subspecies share the ability to aerobically degrade phenol. The degradation rates of phenol for strain J(T) and reference phenol degrading bacteria were determined by photometrically measuring the change in optical density when grown on 0.1% phenol as the sole carbon source, followed by addition of Gibb's reagent to measure depletion of substrate. The phenol degradation rates of strain J(T) was found to exceed that of the phenol hydroxylase group III bacterium Pseudomonas pseudoalcaligenes, with isolate J(T) exhibiting a doubling time of 4.5 h. The presence of the large subunit of the multicomponent phenol hydroxylase gene in strain J(T) was confirmed by PCR. The presence of the nirK nitrite reductase gene as demonstrated by PCR as well as results obtained from nitrite media indicated denitrification at least to N2O. Based on phenotypic, phylogenetic, fatty acid analysis and results from DNA DNA hybridization, we propose assigning a novel subspecies of Alcaligenes faecalis, to be named Alcaligenes faecalis subsp. phenolicus with the type strain J(T) (= DSM 16503) (= NRRL B-41076).
Hyaluronate lyase (HAase) genes of Streptococcus intermedius and Streptococcus constellatus subsp. constellatus were isolated. In S. constellatus subsp. constellatus, the deduced amino acid sequence of HAase was most similar to that of S. intermedius (68%), whereas the enzyme of S. intermedius was most similar to that of S. pneumoniae (72%). Upstream of the HAase gene on the opposite strands, an open reading frame of a putative glutathione peroxidase started in S. intermedius, and this arrangement was similar to that in S. pneumoniae but unlike that in S. constellatus subsp. constellatus. Cell lysates of Escherichia coli carrying each streptococcal gene showed HAase activity, demonstrating that each cloned gene actually coded for HAase.
Tonelli, A; Sacchini, F; Krasteva, I; Zilli, K; Scacchia, M; Beaurepaire, C; Nantel, A; Pini, A
The present study describes the use of microarray technology for rapid identification and differentiation of Mycoplasma mycoides subsp. mycoides from other mycoplasmas that may be pathogenic to ruminants, including those of the Mycoplasma mycoides cluster, genetically and antigenically strictly correlated with Mycoplasma mycoides subsp. mycoides. A microarray containing genetic sequences of 55 different bacterial species from Acholeplasma, Mycoplasma, Spiroplasma and Ureaplasma genera was constructed. Sequences to genes of interest were collected in FASTA format from NCBI. The collected sequences were processed with OligoPicker software. Oligonucleotides were then checked for their selectivity with BLAST searches in GenBank. The microarray was tested with ATCC/NCTC strains of Mycoplasma spp. of veterinary importance in ruminants including Mycoplasma belonging to the mycoides cluster as well as Mycoplasma mycoides subsp. mycoides and Mycoplasma mycoides subsp. capri field strains. The results showed that but one ATCC/NCTC reference strains hybridized with their species-specific sequences showed a profile/signature different and distinct from each other. The heat-map of the hybridization results for the nine genes interrogated for Mycoplasma mycoides subsp. mycoides demonstrated that the reference strain Mycoplasma mycoides subsp mycoides PG1 was positive for all of the gene sequences spotted on the microarray. CBPP field, vaccine and reference strains were all typed to be M. mycoides subsp. mycoides, and seven of the nine strains gave positive hybridization results for all of the nine genes. Two Italian strains were negative for some of the genes. Comparison with non-Mycoplasma mycoides subsp. mycoides reference strains showed some positive signals or considerable homology to Mycoplasma mycoides subsp. mycoides genes. As expected, some correlations were observed between the strictly genetically and antigenically correlated Mycoplasma mycoides subsp. mycoides and
Pollard, Dominic J.; Young, Joanna C.; Covarelli, Valentina; Herrera-León, Silvia; Connor, Thomas R.; Fookes, Maria; Walker, Danielle; Echeita, Aurora; Thomson, Nicholas R.; Berger, Cedric N.
Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs. Though several key S. Typhimurium effector genes are missing (e.g., avrA, sopB, and sseL), S. enterica subsp. salamae invades HeLa cells and contains homologues of S. bongori sboK and sboC, which we named seoC. SboC and SeoC are homologues of EspJ from enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), which inhibit Src kinase-dependent phagocytosis by ADP-ribosylation. By screening 73 clinical and environmental Salmonella isolates, we identified EspJ homologues in S. bongori, S. enterica subsp. salamae, and Salmonella enterica subsp. arizonae. The β-lactamase TEM-1 reporter system showed that SeoC is translocated by the SPI-1 T3SS. All the Salmonella SeoC/SboC homologues ADP-ribosylate Src E310 in vitro. Ectopic expression of SeoC/SboC inhibited phagocytosis of IgG-opsonized beads into Cos-7 cells stably expressing green fluorescent protein (GFP)-FcγRIIa. Concurrently, S. enterica subsp. salamae infection of J774.A1 macrophages inhibited phagocytosis of beads, in a seoC-dependent manner. These results show that S. bongori, S. enterica subsp. salamae, and S. enterica subsp. arizonae share features of the infection strategy of extracellular pathogens EPEC and EHEC and shed light on the complexities of the T3SS effector repertoires of Enterobacteriaceae. PMID:27736780
Al-Momani, W; Nicholas, R A J; Janakat, S; Abu-Basha, E; Ayling, R D
Respiratory disease in sheep and goats is a major problem in Jordan and is often associated with Mycoplasma species. Without effective vaccines, control is mainly by chemotherapy, but the uncontrolled use of antimicrobials has led to concerns about the potential development of antimicrobial resistance. The in vitro effect of chloramphenicol, florfenicol, enrofloxacin, tylosin, erythromycin and oxytetracycline was determined against 32 isolates of Mycoplasma species-M. mycoides subsp. mycoides LC (6), M. capricolum subsp. capricolum (8) and M. putrefaciens (18), all isolated from either nasal swabs or milk, from sheep and goats in different regions of Jordan. The antimicrobial susceptibility showed some Mycoplasma species-specific differences, with M. capricolum subsp. capricolum being more susceptible to tylosin and erythromycin. Chloramphenicol and florfenicol were the least effective for all three Mycoplasma species. No trends or significant differences in antimicrobial susceptibilities were observed between sheep and goat isolates, between milk or nasal swab isolates, or between isolates from different regions of Jordan. Some isolates of M. capricolum subsp. capricolum and M. putrefaciens showed higher MIC levels with oxytetracycline, as did two isolates of M. mycoides subsp. mycoides LC with tylosin, possibly indicating signs of development of antimicrobial resistance.
Gupta, Sushim K.; McMillan, Elizabeth A.; Jackson, Charlene R.; Desai, Prerak T.; Porwollik, Steffen; McClelland, Michael; Hiott, Lari M.; Humayoun, Shaheen B.
Here, we report a 4.87-Mbp draft genome sequence of the multidrug-resistant (MDR) Salmonella enterica subsp. enterica serovar Bardo strain CRJJGF_00099, isolated from dairy cattle in 2005. PMID:27634995
Tupikin, Alexey E.; Kalmykova, Anna I.
Here, we report the draft genome sequence of Bifidobacterium longum subsp. longum strain MC-42 isolated from the feces of a healthy infant, and which was used in the commercially available probiotic product Biovestin. PMID:27979954
Poehlein, Anja; Najdenski, Hristo; Simeonova, Diliana D
We present here the 5.561-Mbp assembled draft genome sequence of Klebsiella pneumoniae subsp. pneumoniae ATCC 9621, a phosphite- and organophosphonate-assimilating Gammaproteobacterium. The genome harbors 5,179 predicted protein-coding genes.
Mycobacterium avium subsp. paratuberculosis (MAP) purified protein derivatives (PPDs) are immunologic reagents prepared from cultured filtrates of the type strain ATCC 19698. Traditional production consists of floating culture incubation at 37oC, organism inactivation by autoclaving, coarse filtrat...
Milani, Christian; Duranti, Sabrina; Lugli, Gabriele Andrea; Bottacini, Francesca; Strati, Francesco; Arioli, Stefania; Foroni, Elena; Turroni, Francesca; van Sinderen, Douwe
Strains of Bifidobacterium animalis subsp. lactis are extensively exploited by the food industry as health-promoting bacteria, although the genetic variability of members belonging to this taxon has so far not received much scientific attention. In this article, we describe the complete genetic makeup of the B. animalis subsp. lactis Bl12 genome and discuss the genetic relatedness of this strain with other sequenced strains belonging to this taxon. Moreover, a detailed comparative genomic analysis of B. animalis subsp. lactis genomes was performed, which revealed a closely related and isogenic nature of all currently available B. animalis subsp. lactis strains, thus strongly suggesting a closed pan-genome structure of this bacterial group. PMID:23645200
Campylobacter fetus subsp. testudinum has been isolated from reptiles and humans. This Campylobacter subspecies is genetically distinct from other C. fetus subspecies. Here we present the first whole genome sequence for this C. fetus subspecies....
Poopathi, Subbiah; Kumar, K Anup
The production of Bacillus thuringiensis subsp. israelensis (deBarjac) (Bti) as a biopesticide is not cost-effective using existing fermentation technology. In this study, we explored the use of several less expensive alternative culture media (potato, common sugar, and Bengal gram) for the growth and production of Bti. Growth was obtained in all tested media and was comparable to that obtained in conventional medium (Luria-Bertani). Toxicity assays showed that the toxin produced from the novel growth media were effective in killing larvae of Culex quinquefasciatus, Anopheles stephensi, and Aedes aegypti and toxicity was comparable to that produced from Luria-Bertani medium. These observations suggest that potato can be used as a cheap source of culture medium for the production of Bti toxin in mosquito control programs.
Sakurai, Kazutoshi; Tomiyama, Kenichi; Kawakami, Yukihiko; Ochiai, Nozomi; Yabe, Shigeki; Nakagawa, Tomomi; Asakawa, Yoshinori
The volatile components from the thalloid liverwort, Marchantia paleacea subsp. diptera were investigated by HS-SPME-GC-MS analysis. The monocyclic monoterpene aldehyde, perillaldehyde was identified for the first time as the major component and its content was about 50% of the volatiles, along with β-pinene, limonene, β-caryophyllene, α-selinene and β-selinene as minor volatiles. Using MD (Multi-dimensional) GC-MS analysis equipped with a chiral column as the second column, the chirality was determined of both perillaldehyde and limonene, which was considered as the precursor of perillaldehyde. Both compounds were (S)-(-)-enantiomers (over 99.0 %) and (R)-enantiomers (less than 0.5 %). This is the first report of the existence of perillaldehyde in liverworts.
Wei, Peilian; Lin, Meng; Wang, Zhongqiang; Fu, Hongxin; Yang, Hopen; Jiang, Wenyan; Yang, Shang-Tian
Propionibacterium freudenreichii cannot use xylose, the second most abundant sugar in lignocellulosic biomass. Although Propionibacterium acidipropionici can use xylose as a carbon source, it is difficult to genetically modify, impeding further improvement through metabolic engineering. This study identified three xylose catabolic pathway genes encoding for xylose isomerase (xylA), xylose transporter (xylT), and xylulokinase (xylB) in P. acidipropionici and overexpressed them in P. freudenreichii subsp. shermanii via an expression plasmid pKHEM01, enabling the mutant to utilize xylose efficiently even in the presence of glucose without glucose-induced carbon catabolite repression. The mutant showed similar fermentation kinetics with glucose, xylose, and the mixture of glucose and xylose, respectively, as carbon source, and with or without the addition of antibiotic for selection pressure. The engineered P. shermanii thus can provide a novel cell factory for industrial production of propionic acid and other value-added products from lignocellulosic biomass.
Whan, Lynne; Ball, Hywel J; Grant, Irene R; Rowe, Michael T
Mycobacterium avium subsp. paratuberculosis is the known cause of Johne's disease of both domestic and wild ruminants and has been implicated as a possible cause of Crohn's disease in humans. The organism is shed in the feces of infected animals and can survive for protracted periods in the environment and hence could be present in catchment areas receiving agricultural runoff. A limited survey was undertaken in Northern Ireland to test for M. avium subsp. paratuberculosis in untreated water entering nine water treatment works (WTWs) over a 1-year period. Three detection methods were employed, viz., immunomagnetic separation-PCR and culture on Herrold's egg yolk medium (HEYM) and BACTEC 12B medium, the latter both supplemented with mycobactins. Of the 192 untreated water samples tested, 15 (8%) tested M. avium subsp. paratuberculosis positive by one or more of the three detection methods. M. avium subsp. paratuberculosis was successfully isolated from eight untreated water samples, three by BACTEC culture and five by culture on HEYM. Although the highest incidence of M. avium subsp. paratuberculosis was found in spring, overall, there was no statistically significant difference between the seasons. No significant correlation was found between numbers of coliforms or fecal coliforms and the presence of M. avium subsp. paratuberculosis. In general, a higher incidence of M. avium subsp. paratuberculosis was found in untreated water entering those WTWs that had a high mean water pH value over the sampling period. This work indicates the need to determine the efficacy of water treatment processes to either kill or remove M. avium subsp. paratuberculosis from untreated water and the possible risks posed by contact with recreational water sources.
Las Heras, Alfonso; Vela, Ana I; Fernández, Elena; Legaz, Emilio; Domínguez, Lucas; Fernández-Garayzábal, Jose F
This work describes an outbreak of clinical mastitis affecting 13 of 58 lactating ewes due to Streptococcus equi subsp. zooepidemicus. S. equi subsp. zooepidemicus was isolated in pure culture from all milk samples. All the clinical isolates had identical biochemical profiles and antimicrobial susceptibility patterns and also exhibited indistinguishable macrorestriction patterns by pulsed-field gel electrophoresis, indicating that all cases of mastitis were produced by a single strain.
Las Heras, Alfonso; Vela, Ana I.; Fernández, Elena; Legaz, Emilio; Domínguez, Lucas; Fernández-Garayzábal, Jose F.
This work describes an outbreak of clinical mastitis affecting 13 of 58 lactating ewes due to Streptococcus equi subsp. zooepidemicus. S. equi subsp. zooepidemicus was isolated in pure culture from all milk samples. All the clinical isolates had identical biochemical profiles and antimicrobial susceptibility patterns and also exhibited indistinguishable macrorestriction patterns by pulsed-field gel electrophoresis, indicating that all cases of mastitis were produced by a single strain. PMID:11880454
Yasuhara-Bell, Jarred; Alvarez, Anne M
The genus Clavibacter contains one recognized species, Clavibacter michiganensis. Clavibacter michiganensis is subdivided into subspecies based on host specificity and bacteriological characteristics, with Clavibacter michiganensis subsp. michiganensis causing bacterial canker of tomato. Clavibacter michiganensis subsp. michiganensis is often spread through contaminated seed leading to outbreaks of bacterial canker in tomato production areas worldwide. The frequent occurrence of non-pathogenic Clavibacter michiganensis subsp. michiganensis-like bacteria (CMB) is a concern for seed producers because Clavibacter michiganensis subsp. michiganensis is a quarantine organism and detection of a non-pathogenic variant may result in destruction of an otherwise healthy seed lot. A thorough biological and genetic characterization of these seed-associated CMB strains was performed using standard biochemical tests, cell wall analyses, metabolic profiling using Biolog, and single-gene and multilocus sequence analyses. Combined, these tests revealed two distinct populations of seed-associated members of the genus Clavibacter that differed from each other, as well as from all other described subspecies of Clavibacter michiganensis. DNA-DNA hybridization values are 70 % or higher, justifying placement into the single recognized species, C. michiganensis, but other analyses justify separate subspecies designations. Additionally, strains belonging to the genus Clavibacter isolated from pepper also represent a distinct population and warrant separate subspecies designation. On the basis of these data we propose subspecies designations for separate non-pathogenic subpopulations of Clavibacter michiganensis: Clavibacter michiganensis subsp. californiensis subsp. nov. and Clavibacter michiganensis subsp. chilensis subsp. nov. for seed-associated strains represented by C55(T) ( = ATCC BAA-2691(T) = CFBP 8216(T)) and ZUM3936(T) ( = ATCC BAA-2690(T) = CFBP 8217(T
Foddai, Antonio; Elliott, Christopher T.; Grant, Irene R.
In order to introduce specificity for Mycobacterium avium subsp. paratuberculosis prior to a phage amplification assay, various magnetic-separation approaches, involving either antibodies or peptides, were evaluated in terms of the efficiency of capture (expressed as a percentage) of M. avium subsp. paratuberculosis cells and the percentage of nonspecific binding by other Mycobacterium spp. A 50:50 mixture of MyOne Tosylactivated Dynabeads coated with the chemically synthesized M. avium subsp. paratuberculosis-specific peptides biotinylated aMp3 and biotinylated aMptD (i.e., peptide-mediated magnetic separation [PMS]) proved to be the best magnetic-separation approach for achieving 85 to 100% capture of M. avium subsp. paratuberculosis and minimal (<1%) nonspecific recovery of other Mycobacterium spp. (particularly if beads were blocked with 1% skim milk before use) from broth samples containing 103 to 104 CFU/ml. When PMS was coupled with a recently optimized phage amplification assay and used to detect M. avium subsp. paratuberculosis in 50-ml volumes of spiked milk, the mean 50% limit of detection (LOD50) was 14.4 PFU/50 ml of milk (equivalent to 0.3 PFU/ml). This PMS-phage assay represents a novel, rapid method for the detection and enumeration of viable M. avium subsp. paratuberculosis organisms in milk, and potentially other sample matrices, with results available within 48 h. PMID:20851966
Tetreau, Guillaume; Stalinski, Renaud; Kersusan, Dylann; Veyrenc, Sylvie; David, Jean-Philippe; Reynaud, Stéphane; Després, Laurence
Bacillus thuringiensis subsp. israelensis is a bacterium producing crystals containing Cry and Cyt proteins, which are toxic for mosquito larvae. Nothing is known about the interaction between crystal toxins and decaying leaf litter, which is a major component of several mosquito breeding sites and represents an important food source. In the present work, we investigated the behavior of B. thuringiensis subsp. israelensis toxic crystals sprayed on leaf litter. In the presence of leaf litter, a 60% decrease in the amount of Cyt toxin detectable by immunology (enzyme-linked immunosorbent assays [ELISAs]) was observed, while the respective proportions of Cry toxins were not affected. The toxicity of Cry toxins toward Aedes aegypti larvae was not affected by leaf litter, while the synergistic effect of Cyt toxins on all B. thuringiensis subsp. israelensis Cry toxins was decreased by about 20% when mixed with leaf litter. The toxicity of two commercial B. thuringiensis subsp. israelensis strains (VectoBac WG and VectoBac 12AS) and a laboratory-produced B. thuringiensis subsp. israelensis strain decreased by about 70% when mixed with leaf litter. Taken together, these results suggest that Cyt toxins interact with leaf litter, resulting in a decreased toxicity of B. thuringiensis subsp. israelensis in litter-rich environments and thereby dramatically reducing the efficiency of mosquitocidal treatments.
Priestnall, Simon L.; Erles, Kerstin; Brooks, Harriet W.; Cardwell, Jacqueline M.; Waller, Andrew S.; Paillot, Romain; Robinson, Carl; Darby, Alistair C.; Holden, Matthew T. G.; Schöniger, Sandra
Streptococcus equi subsp. zooepidemicus has been linked to cases of acute fatal pneumonia in dogs in several countries. Outbreaks can occur in kenneled dog populations and result in significant levels of morbidity and mortality. This highly contagious disease is characterized by the sudden onset of clinical signs, including pyrexia, dyspnea, and hemorrhagic nasal discharge. The pathogenesis of S. equi subsp. zooepidemicus infection in dogs is poorly understood. This study systematically characterized the histopathological changes in the lungs of 39 dogs from a large rehoming shelter in London, United Kingdom; the dogs were infected with S. equi subsp. zooepidemicus. An objective scoring system demonstrated that S. equi subsp. zooepidemicus caused pneumonia in 26/39 (66.7%) dogs, and most of these dogs (17/26 [65.4%]) were classified as severe fibrino-suppurative, necrotizing, and hemorrhagic. Three recently described superantigen genes (szeF, szeN, and szeP) were detected by PCR in 17/47 (36.2%) of the S. equi subsp. zooepidemicus isolates; however, there was no association between the presence of these genes and the histopathological score. The lungs of S. equi subsp. zooepidemicus-infected dogs with severe respiratory signs and lung pathology did however have significantly higher mRNA levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and interleukin 8 (IL-8) than in uninfected controls, suggesting a role for an exuberant host immune response in the pathogenesis of this disease. PMID:20861329
Stalinski, Renaud; Kersusan, Dylann; Veyrenc, Sylvie; David, Jean-Philippe; Reynaud, Stéphane; Després, Laurence
Bacillus thuringiensis subsp. israelensis is a bacterium producing crystals containing Cry and Cyt proteins, which are toxic for mosquito larvae. Nothing is known about the interaction between crystal toxins and decaying leaf litter, which is a major component of several mosquito breeding sites and represents an important food source. In the present work, we investigated the behavior of B. thuringiensis subsp. israelensis toxic crystals sprayed on leaf litter. In the presence of leaf litter, a 60% decrease in the amount of Cyt toxin detectable by immunology (enzyme-linked immunosorbent assays [ELISAs]) was observed, while the respective proportions of Cry toxins were not affected. The toxicity of Cry toxins toward Aedes aegypti larvae was not affected by leaf litter, while the synergistic effect of Cyt toxins on all B. thuringiensis subsp. israelensis Cry toxins was decreased by about 20% when mixed with leaf litter. The toxicity of two commercial B. thuringiensis subsp. israelensis strains (VectoBac WG and VectoBac 12AS) and a laboratory-produced B. thuringiensis subsp. israelensis strain decreased by about 70% when mixed with leaf litter. Taken together, these results suggest that Cyt toxins interact with leaf litter, resulting in a decreased toxicity of B. thuringiensis subsp. israelensis in litter-rich environments and thereby dramatically reducing the efficiency of mosquitocidal treatments. PMID:22610426
Viulu, Samson; Nakamura, Kohei; Kojima, Akihiro; Yoshiyasu, Yuki; Saitou, Sakiko; Takamizawa, Kazuhiro
An ethanol-utilizing Fe(III)-reducing bacterial strain, OSK2A(T), was isolated from a lotus field in Aichi, Japan. Phylogenetic analysis of the 16S rRNA gene sequences of OSK2A(T) and related strains placed it within Geobacter sulfurreducens PCA(T). Strain OSK2A(T) was shown to be a Gram-negative, motile, rod-shaped bacterium, strictly anaerobic, 0.76-1.65 µm long and 0.28-0.45 μm wide. Its growth occurred at 20-40℃, pH 6.0-8.1, and it tolerated up to 1% NaCl. The G+C content of the genomic DNA was 61.2 mol% and DNA-DNA hybridization value with Geobacter sulfurreducens PCA(T) was 60.7%. The major respiratory quinone was MK-8. The major fatty acids were 16：1 ω7c, 16：0, 14：0, 15：0 iso, 16：1 ω5c, and 18：1 ω7c. Strain OSK2A(T) could utilize H2, ethanol, acetate, lactate, pyruvate, and formate as substrates with Fe(III)-citrate as electron acceptor. Amorphous Fe(III) hydroxide, Fe(III)-NTA, fumarate, malate, and elemental sulfur were utilized as electron acceptors with either acetate or ethanol as substrates. Results obtained from physiological, DNA-DNA hybridization, and chemotaxonomic tests support genotypic and phenotypic differentiation of strain OSK2A(T) from its closest relative. The isolate is assigned as a novel subspecies with the name Geobacter sulfurreducens subsp. ethanolicus, subsp. nov. (type strain OSK2A(T)=DSMZ 26126(T)=JCM 18752(T)).
Perin, Luana Martins; Dal Bello, Barbara; Belviso, Simona; Zeppa, Giuseppe; de Carvalho, Antônio Fernandes; Cocolin, Luca; Nero, Luís Augusto
Minas cheese is a popular dairy product in Brazil that is traditionally produced using raw or pasteurized cow milk. This study proposed an alternative production of Minas cheese using raw goat milk added of a nisin producer Lactococcus lactis subsp. lactis GLc05. An in situ investigation was carried on to evaluate the interactions between the L. lactis subsp. lactis GLc05 and the autochthonous microbiota of a Minas cheese during the ripening; production of biogenic amines (BAs) was assessed as a safety aspect. Minas cheese was produced in two treatments (A, by adding L. lactis subsp. lactis GLc05, and B, without adding this strain), in three independent repetitions (R1, R2, and R3). Culture dependent (direct plating) and independent (rep-PCR and PCR-DGGE) methods were employed to characterize the microbiota and to assess the possible interferences caused by L. lactis subsp. lactis GLc05. BA amounts were measured using HPLC. A significant decrease in coagulase-positive cocci was observed in the cheeses produced by adding L. lactis subsp. lactis GLc05 (cheese A). The rep-PCR and PCR-DGGE highlighted the differences in the microbiota of both cheeses, separating them into two different clusters. Lactococcus sp. was found as the main microorganism in both cheeses, and the microbiota of cheese A presented a higher number of species. High concentrations of tyramine were found in both cheeses and, at specific ripening times, the BA amounts in cheese B were significantly higher than in cheese A (p<0.05). The interaction of nisin producer L. lactis subsp. lactis GLc05 was demonstrated in situ, by demonstration of its influence in the complex microbiota naturally present in a raw goat milk cheese and by controlling the growth of coagulase-positive cocci. L. lactis subsp. lactis GLc05 influenced also the production of BA determining that their amounts in the cheeses were maintained at acceptable levels for human consumption.
Khodavaisy, Sadegh; Rezaie, Sassan; Noorbakhsh, Fatemeh; Baghdadi, Elham; Sharifynia, Somayeh; Aala, Farzad
Background Aflatoxins are highly toxic secondary metabolites mainly produced by Aspergillus parasiticus. This species can contaminate a wide range of agricultural commodities, including cereals, peanuts, and crops in the field. In recent years, research on medicinal herbs, such as Pistacia atlantica subsp. kurdica, have led to reduced microbial growth, and these herbs also have a particular effect on the production of aflatoxins as carcinogenic compounds. Objectives In this study, we to examine P. atlantica subsp. kurdica as a natural compound used to inhibit the growth of A. parasiticus and to act as an anti-mycotoxin. Materials and Methods In vitro antifungal susceptibility testing of P. atlantica subsp. kurdica for A. parasiticus was performed according to CLSI document M38-A2. The rate of aflatoxin production was determined using the HPLC technique after exposure to different concentrations (62.5 - 125 mg/mL) of the gum. The changes in expression levels of the aflR gene were analyzed with a quantitative real-time PCR assay. Results The results showed that P. atlantica subsp. kurdica can inhibit A. parasiticus growth at a concentration of 125 mg/mL. HPLC results revealed a significant decrease in aflatoxin production with 125 mg/mL of P. atlantica subsp. kurdica, and AFL-B1 production was entirely inhibited. Based on quantitative real-time PCR results, the rate of aflR gene expression was significantly decreased after treatment with P. atlantica subsp. kurdica. Conclusions Pistacia atlantica subsp. kurdica has anti-toxic properties in addition to an inhibitory effect on A. parasiticus growth, and is able to decrease aflatoxin production effectively in a dose-dependent manner. Therefore, this herbal extract maybe considered a potential anti-mycotoxin agent in medicine or industrial agriculture. PMID:27800127
Loquasto, Joseph R.; Barrangou, Rodolphe; Dudley, Edward G.; Stahl, Buffy; Chen, Chun
Many strains of Bifidobacterium animalis subsp. lactis are considered health-promoting probiotic microorganisms and are commonly formulated into fermented dairy foods. Analyses of previously sequenced genomes of B. animalis subsp. lactis have revealed little genetic diversity, suggesting that it is a monomorphic subspecies. However, during a multilocus sequence typing survey of Bifidobacterium, it was revealed that B. animalis subsp. lactis ATCC 27673 gave a profile distinct from that of the other strains of the subspecies. As part of an ongoing study designed to understand the genetic diversity of this subspecies, the genome of this strain was sequenced and compared to other sequenced genomes of B. animalis subsp. lactis and B. animalis subsp. animalis. The complete genome of ATCC 27673 was 1,963,012 bp, contained 1,616 genes and 4 rRNA operons, and had a G+C content of 61.55%. Comparative analyses revealed that the genome of ATCC 27673 contained six distinct genomic islands encoding 83 open reading frames not found in other strains of the same subspecies. In four islands, either phage or mobile genetic elements were identified. In island 6, a novel clustered regularly interspaced short palindromic repeat (CRISPR) locus which contained 81 unique spacers was identified. This type I-E CRISPR-cas system differs from the type I-C systems previously identified in this subspecies, representing the first identification of a different system in B. animalis subsp. lactis. This study revealed that ATCC 27673 is a strain of B. animalis subsp. lactis with novel genetic content and suggests that the lack of genetic variability observed is likely due to the repeated sequencing of a limited number of widely distributed commercial strains. PMID:23995933
Turner, J T; Lampel, J S; Stearman, R S; Sundin, G W; Gunyuzlu, P; Anderson, J J
Deletion of chromosomally inserted gene sequences from Clavibacter xyli subsp. cynodontis, a xylem-inhabiting endophyte, was studied in vitro and in planta. We found that nonreplicating plasmid pCG610, which conferred resistance to kanamycin and tetracycline and contained segments of C. xyli subsp. cynodontis genomic DNA, integrated into a homologous sequence in the bacterial chromosome. In addition, pCG610 contains two copies of the gene encoding the CryIA(c) insecticidal protein of Bacillus thuringiensis subsp. kurstaki HD73. Using drug resistance phenotypes and specific DNA probes, we found that the loss of all three genes arose both in vitro under nonselective conditions and in planta. The resulting segregants are probably formed by recombination between the repeated DNA sequences flanking pCG610 that resulted from the integration event into the chromosome. Eventually, segregants predominated in the bacterial population. The loss of the integrated plasmid from C. xyli subsp. cynodontis revealed a possible approach for decreasing the environmental consequences of recombinant bacteria for agricultural use.
In vitro studies of Lactobacillus delbrueckii subsp. lactis in Atlantic salmon (Salmo salar L.) foregut: tissue responses and evidence of protection against Aeromonas salmonicida subsp. salmonicida epithelial damage.
Salinas, Irene; Myklebust, Reidar; Esteban, Maria Angeles; Olsen, Rolf Erik; Meseguer, José; Ringø, Einar
Probiotic bacteria increase the host health status and protect mucosal tissue against pathogen-caused damage in mammalian models. Using an in vitro (intestinal sac) method this study aimed to address (a) the in vitro ability of Lactobacillus delbrueckii subsp. lactis to remain in the gastrointestinal tract of Atlantic salmon (Salmo salar L.) and (b) its ability to prevent cellular damage caused by successive incubation with Aeromonas salmonicida subsp. salmonicida the causative agent of furunculosis. Short in vitro incubation of salmon foregut with (TRITC)-labelled L. delbrueckii subsp. lactis showed that the probiont was able to colonize the enterocyte surface as studied by confocal microscopy. Furthermore, foregut incubated with the probiotic bacteria only, resulted in a healthy intestinal barrier whereas exposure to A. salmonicida disrupted its integrity. However, pre-treatment of salmon intestine with L. delbrueckii subsp. lactis prevented Aeromonas damaging effects. These results are promising in the context of the use of non-autochthonous probiotic bacteria as prophylactic agents against fish bacterial infections in the gastrointestinal tract.
Piras, Cristian; Soggiu, Alessio; Bonizzi, Luigi; Greco, Viviana; Ricchi, Matteo; Arrigoni, Norma; Bassols, Anna; Urbani, Andrea; Roncada, Paola
Mycobacterium avium subsp. paratuberculosis (MAP) is the cause of a chronic enteritis of ruminants (bovine paratuberculosis (PTB)--Johne's disease) that is associated with enormous worldwide economic losses for the animal production. Diagnosis is based on observation of clinical signs, the detection of antibodies in milk or serum, or evaluation of bacterial culture from feces. The limit of these methods is that they are not able to detect the disease in the subclinical stage and are applicable only when the disease is already advanced. For this reason, the main purpose of this study is to use the MAP proteome to detect novel immunoreactive proteins that may be helpful for PTB diagnoses. 2DE and 2D immunoblotting of MAP proteins were performed using sera of control cattle and PTB-infected cattle in order to highlight the specific immunoreactive proteins. Among the assigned identifiers to immunoreactive spots it was found that most of them correspond to surface-located proteins while three of them have never been described before as antigens. The identification of these proteins improves scientific knowledge that could be useful for PTB diagnoses. The sequence of the identified protein can be used for the synthesis of immunoreactive peptides that could be screened for their immunoreaction against bovine sera infected with MAP. All MS data have been deposited in the ProteomeXchange consortium with identifier PXD001159 and DOI 10.6019/PXD001159.
Delorme, C; Ehrlich, S D; Renault, P
The genes of Lactococcus lactis subsp. lactis involved in histidine biosynthesis were cloned and characterized by complementation of Escherichia coli and Bacillus subtilis mutants and DNA sequencing. Complementation of E. coli hisA, hisB, hisC, hisD, hisF, hisG, and hisIE genes and the B. subtilis hisH gene (the E. coli hisC equivalent) allowed localization of the corresponding lactococcal genes. Nucleotide sequence analysis of the 11.5-kb lactococcal region revealed 14 open reading frames (ORFs), 12 of which might form an operon. The putative operon includes eight ORFs which encode proteins homologous to enzymes involved in histidine biosynthesis. The operon also contains (i) an ORF encoding a protein homologous to the histidyl-tRNA synthetases but lacking a motif implicated in synthetase activity, which suggests that it has a role different from tRNA aminoacylation, and (ii) an ORF encoding a protein that is homologous to the 3'-aminoglycoside phosphotransferases but does not confer antibiotic resistance. The remaining ORFs specify products which have no homology with proteins in the EMBL and GenBank data bases. PMID:1400209
Johne's disease or paratuberculosis is a chronic debilitating disease in ruminants caused by Mycobacterium avium subsp. paratuberculosis (MAP). The disease causes significant economic losses in livestock industries worldwide. There are no effective control measures to eradicate the disease because there are no appropriate diagnostic methods to detect subclinically infected animals. Therefore, it is very difficult to control the disease using only test and cull strategies. Vaccination against paratuberculosis has been considered as an alternative strategy to control the disease when combined with management interventions. Understanding host-pathogen interactions is extremely important to development of vaccines. It has long been known that Th1-mediated cellular immune responses are play a crucial role in protection against MAP infection. However, recent studies suggested that innate immune responses are more closely related to protective effects than adaptive immunity. Based on this understanding, several attempts have been made to develop vaccines against paratuberculosis. A variety of ideas for designing novel vaccines have emerged, and the tests of the efficacy of these vaccines are conducted constantly. However, no effective vaccines are commercially available. In this study, studies of the development of vaccines for MAP were reviewed and summarized. PMID:27489800
López-Lázaro, Miguel; Palma De La Peña, Nieves; Pastor, Nuria; Martín-Cordero, Carmen; Navarro, Eduardo; Cortés, Felipe; Ayuso, María Jesús; Toro, María Victoria
Recent research has shown the anticancer effects of digitalis compounds suggesting their possible use in medical oncology. Four extracts obtained from the leaves of Digitalis purpurea subsp. heywoodii have been assessed for cytotoxic activity against three human cancer cell lines, using the SRB assay. All of them showed high cytotoxicity, producing IC50 values in the 0.78 - 15 microg/mL range with the methanolic extract being the most active, in non toxic concentrations. Steroid glycosides (gitoxigenin derivatives) were detected in this methanolic extract. Gitoxigenin and gitoxin were evaluated in the SRB assay using the three human cancer cell lines, showing IC50 values in the 0.13 - 2.8 microM range, with the renal adenocarcinoma cancer cell line (TK-10) being the most sensitive one. Morphological apoptosis evaluation of the methanolic extract and both compounds on the TK-10 cell line showed that their cytotoxicity was mediated by an apoptotic effect. Finally, possible mechanisms involved in apoptosis induction by digitalis compounds are discussed.
Kennedy, D J; Benedictus, G
Paratuberculosis or Johne's disease is a chronic intestinal disease caused by Mycobacterium avium subsp. paratuberculosis, which continues to spread in agricultural species. Control of paratuberculosis is challenging and should not be underestimated. Due to the long incubation period of the infection, disease is largely subclinical in domesticated livestock. Hence, direct effects on animal productivity and welfare are often masked and may appear insufficient to justify large investments in control programmes by individual farmers, livestock industries or governments. Furthermore, in some countries the main effects of the disease are indirect, resulting from the impact of market discrimination against herds and flocks known to be infected, or from the control measures enforced to reduce transmission. In such circumstances, producers may be unwilling to co-operate with surveillance that may detect infection in herds or flocks. As control programmes are rarely successful in eliminating the infection from a herd or flock in the short term without an aggressive and costly programme, financial and community support assists producers to deal with the challenge. Successful prevention and control depends on animal health authorities and livestock industries acquiring a good understanding of the nature and epidemiology of infection, and of the application of tools for diagnosis and control. Building support for control programmes under the leadership of the affected livestock industries is critical, as programmes are unlikely to be successful without ongoing political will, supported by funding for research, surveillance and control.
Wajima, Takeaki; Morozumi, Miyuki; Hanada, Shigeo; Sunaoshi, Katsuhiko; Chiba, Naoko; Iwata, Satoshi; Ubukata, Kimiko
We collected β-hemolytic streptococci (1,611 isolates) from patients with invasive streptococcal infections in Japan during April 2010-March 2013. Streptococcus dysgalactiae subsp. equisimilis (SDSE) was most common (n = 693); 99% of patients with SDSE infections were elderly (mean age 75 years, SD ±15 years). We aimed to clarify molecular and epidemiologic characteristics of SDSE isolates and features of patient infections. Bacteremia with no identified focus of origin and cellulitis were the most prevalent manifestations; otherwise, clinical manifestations resembled those of S. pyogenes infections. Clinical manifestations also differed by patient's age. SDSE isolates were classified into 34 emm types; stG6792 was most prevalent (27.1%), followed by stG485 and stG245. Mortality rates did not differ according to emm types. Multilocus sequence typing identified 46 sequence types and 12 novel types. Types possessing macrolide- and quinolone-resistance genes were 18.4% and 2.6%, respectively; none showed β-lactam resistance. Among aging populations, invasive SDSE infections are an increasing risk.
Bacillus thuringiensis subsp. israelensis (Bti) is the first Bacillus thuringiensis to be found and used as an effective biological control agent against larvae of many mosquito and black fly species around the world. Its larvicidal activity resides in four major (of 134, 128, 72 and 27 kDa) and at least two minor (of 78 and 29 kDa) polypeptides encoded respectively by cry4Aa, cry4Ba, cry11Aa, cyt1Aa, cry10Aa and cyt2Ba, all mapped on the 128 kb plasmid known as pBtoxis. These six δ-endotoxins form a complex parasporal crystalline body with remarkably high, specific and different toxicities to Aedes, Culex and Anopheles larvae. Cry toxins are composed of three domains (perforating domain I and receptor binding II and III) and create cation-selective channels, whereas Cyts are composed of one domain that acts as well as a detergent-like membrane perforator. Despite the low toxicities of Cyt1Aa and Cyt2Ba alone against exposed larvae, they are highly synergistic with the Cry toxins and hence their combinations prevent emergence of resistance in the targets. The lack of significant levels of resistance in field mosquito populations treated for decades with Bti-bioinsecticide suggests that this bacterium will be an effective biocontrol agent for years to come. PMID:24686769
Bacillus thuringiensis subsp. israelensis (Bti) is the first Bacillus thuringiensis to be found and used as an effective biological control agent against larvae of many mosquito and black fly species around the world. Its larvicidal activity resides in four major (of 134, 128, 72 and 27 kDa) and at least two minor (of 78 and 29 kDa) polypeptides encoded respectively by cry4Aa, cry4Ba, cry11Aa, cyt1Aa, cry10Aa and cyt2Ba, all mapped on the 128 kb plasmid known as pBtoxis. These six δ-endotoxins form a complex parasporal crystalline body with remarkably high, specific and different toxicities to Aedes, Culex and Anopheles larvae. Cry toxins are composed of three domains (perforating domain I and receptor binding II and III) and create cation-selective channels, whereas Cyts are composed of one domain that acts as well as a detergent-like membrane perforator. Despite the low toxicities of Cyt1Aa and Cyt2Ba alone against exposed larvae, they are highly synergistic with the Cry toxins and hence their combinations prevent emergence of resistance in the targets. The lack of significant levels of resistance in field mosquito populations treated for decades with Bti-bioinsecticide suggests that this bacterium will be an effective biocontrol agent for years to come.
Manning, E J; Collins, M T
Johne's disease, or paratuberculosis, is a chronic intestinal infection caused by Mycobacterium avium subsp. paratuberculosis. The usually fatal disease is characterised by cachexia, and in some species diarrhoea, after a long pre-clinical phase. Treatment is ineffective and economically impracticable. The infection primarily affects domestic and free-ranging ruminants, but has also been reported in primates, rabbits, stoats and foxes. Since paratuberculosis is often subclinical, under-reporting is suspected, even though the disease is notifiable in numerous countries. Herd prevalence of bovine paratuberculosis in Europe ranges from 7% to 55%. In the United States of America, herd prevalence is strongly associated with herd size; 40% of herds of more than 300 head were found to be infected. In Australia, reported dairy herd infection rates range between 9% and 22%. Paratuberculosis in domestic livestock entails significant economic losses due to several factors (e.g. reduced production, premature culling and increased veterinary costs). Free-ranging and captive wildlife are also at risk from paratuberculosis.
Despierres, L; Cohen-Bacrie, S; Richet, H; Drancourt, M
The knowledge of Mycobacterium avium complex (MAC) genotypes responsible for lymphadenitis is limited. We retrospectively characterized all of the MAC isolates made in our laboratory in the last 18 years by sequence-based identification and genotyping, and compared the clinical and laboratory data for lymphadenitis-associated and non-lymphadenitis-associated MAC isolates. Of 67 MAC-infected patients, 25 lymphadenitis patients were significantly younger than 42 non-lymphadenitis patients, while the male/female ratio did not significantly differ between the two groups. Cervical topography found in 76.5% of lymphadenitis patients was significantly more frequent in non-immunocompromised patients (p=0.04). M. avium subsp. hominissuis was identified in 53 patients (24 lymphadenitis, 29 non-lymphadenitis), M. colombiense in six patients (five non-lymphadenitis, one lymphadenitis), M. intracellulare in four non-lymphadenitis patients, and M. chimaera in three non-lymphadenitis patients, while negative controls remained negative. M. hominissuis was significantly associated with lymphadenitis (p=0.03). M. hominissuis isolates yielded 15 genotypes in 29 non-lymphadenitis isolates (molecular diversity, 0.622) versus 11 genotypes in 24 lymphadenitis isolates (molecular diversity, 0.578), demonstrating a non-significant lower diversity of M. hominissuis isolates cultured from lymphadenitis. The genotypes did not correlate with the clinical features. These data suggest the presence of several environmental reservoirs for M. hominissuis causing lymphadenitis in France.
Van Cuyk, Sheila; Deshpande, Alina; Hollander, Attelia; Duval, Nathan; Ticknor, Lawrence; Layshock, Julie; Gallegos-Graves, LaVerne; Omberg, Kristin M.
Bacillus thuringiensis subsp. kurstaki is applied extensively in North America to control the gypsy moth, Lymantria dispar. Since B. thuringiensis subsp. kurstaki shares many physical and biological properties with Bacillus anthracis, it is a reasonable surrogate for biodefense studies. A key question in biodefense is how long a biothreat agent will persist in the environment. There is some information in the literature on the persistence of Bacillus anthracis in laboratories and historical testing areas and for Bacillus thuringiensis in agricultural settings, but there is no information on the persistence of Bacillus spp. in the type of environment that would be encountered in a city or on a military installation. Since it is not feasible to release B. anthracis in a developed area, the controlled release of B. thuringiensis subsp. kurstaki for pest control was used to gain insight into the potential persistence of Bacillus spp. in outdoor urban environments. Persistence was evaluated in two locations: Fairfax County, VA, and Seattle, WA. Environmental samples were collected from multiple matrices and evaluated for the presence of viable B. thuringiensis subsp. kurstaki at times ranging from less than 1 day to 4 years after spraying. Real-time PCR and culture were used for analysis. B. thuringiensis subsp. kurstaki was found to persist in urban environments for at least 4 years. It was most frequently detected in soils and less frequently detected in wipes, grass, foliage, and water. The collective results indicate that certain species of Bacillus may persist for years following their dispersal in urban environments. PMID:21926205
Wirth, Margaret C; Jiannino, Joshua A; Federici, Brian A; Walton, William E
Synergistic interactions among the multiple endotoxins of Bacillus thuringiensis subsp. israelensis de Barjac play an important role in its high toxicity to mosquito larvae and the absence of insecticide resistance in populations treated with this bacterium. A lack of toxin complexity and synergism are the apparent causes of resistance to Bacillus sphaericus Neide in particular Culex field populations. To identify endotoxin combinations of the two Bacillus species that might improve insecticidal activity and manage mosquito resistance to B. sphaericus, we tested their toxins alone and in combination. Most combinations of B. sphaericus and B. t. subsp. israelensis toxins were synergistic and enhanced toxicity relative to B. sphaericus, particularly against Culex quinquefasciatus Say larvae resistant to B. sphaericus and Aedes aegypti (L.), a species poorly susceptible to B. sphaericus. Toxicity also improved against susceptible Cx. quinquefasciatus. For example, when the CytlAa toxin from B. t. subsp. israelensis was added to Bin and Cry toxins, or when native B. t. subsp. israelensis was combined with B. sphaericus, synergism values as high as 883-fold were observed and combinations were 4-59,000-fold more active than B. sphaericus. These data, and previous studies using cytolytic toxins, validate proposed strategies for improving bacterial larvicides by combining B. sphaericus with B. t. subsp. israelensis or by engineering recombinant bacteria that express endotoxins from both strains. These combinations increase both endotoxin complexity and synergistic interactions and thereby enhance activity and help avoid insecticide resistance.
Xu, Xiulan; Rajashekara, Gireesh; Paul, Pierce A; Miller, Sally A
Tomato bacterial canker, caused by Clavibacter michiganensis subsp. michiganensis, is transmitted by infected or infested seed and mechanically from plant to plant. Wounds occurring during seedling production and crop maintenance facilitate the dissemination of the pathogen. However, the effects of environmental factors on C. michiganensis subsp. michiganensis translocation and growth as an endophyte have not been fully elucidated. A virulent, stable, constitutively bioluminescent C. michiganensis subsp. michiganensis strain BL-Cmm 17 coupled with an in vivo imaging system allowed visualization of the C. michiganensis subsp. michiganensis colonization process in tomato seedlings in real time. The dynamics of bacterial infection in seedlings through wounds were compared under low (45%) and high (83%) relative humidity. Bacteria multiplied rapidly in cotyledon petioles remaining after clip inoculation and moved in the stem toward both root and shoot. Luminescent signals were also observed in tomato seedling roots over time, and root development was reduced in inoculated plants maintained under both humidity regimes. Wilting was more severe in seedlings under high-humidity regimes. A strong positive correlation between light intensity and bacterial population in planta suggests that bioluminescent C. michiganensis subsp. michiganensis strains will be useful in evaluating the efficacy of bactericides and host resistance.
Yao, Kuan; Roberts, Richard J.; Allard, Marc W.
ABSTRACT In this announcement, we report the complete genome and methylome sequences of three Salmonella enterica strains from the SARA and SARB collection: S. enterica subsp. enterica serovar Typhimurium (SARA13), S. enterica subsp. enterica serovar Saintpaul (SARA26), and S. enterica subsp. enterica serovar Stanleyville (SARB61). PMID:28302778
Xanthomonas citri subsp. citri, causal agent of Asiatic citrus canker, is an important pathogen of citrus in Brazil and elsewhere. The genetic diversity of X. citri subsp. citri pathtype ‘A’ has not been studied in Brazil at a local scale (up to 300 km). A total of 40 isolates were collected from le...
Oliver, J E; Cobine, P A; De La Fuente, L
Xylella fastidiosa is a xylem-limited gram-negative plant pathogen that affects numerous crop species, including grape, citrus, peach, pecan, and almond. Recently, X. fastidiosa has also been found to be the cause of bacterial leaf scorch on blueberry in the southeastern United States. Thus far, all X. fastidiosa isolates obtained from infected blueberry have been classified as X. fastidiosa subsp. multiplex; however, X. fastidiosa subsp. fastidiosa isolates are also present in the southeastern United States and commonly cause Pierce's disease of grapevines. In this study, seven southeastern U.S. isolates of X. fastidiosa, including three X. fastidiosa subsp. fastidiosa isolates from grape, one X. fastidiosa subsp. fastidiosa isolate from elderberry, and three X. fastidiosa subsp. multiplex isolates from blueberry, were used to infect the southern highbush blueberry 'Rebel'. Following inoculation, all isolates colonized blueberry, and isolates from both X. fastidiosa subsp. multiplex and X. fastidiosa subsp. fastidiosa caused symptoms, including characteristic stem yellowing and leaf scorch symptoms as well as dieback of the stem tips. Two X. fastidiosa subsp. multiplex isolates from blueberry caused more severe symptoms than the other isolates examined, and infection with these two isolates also had a significant impact on host mineral nutrient content in sap and leaves. These findings have potential implications for understanding X. fastidiosa host adaptation and expansion and the development of emerging diseases caused by this bacterium.
Iraola, Gregorio; Pérez, Ruben; Naya, Hugo; Paolicchi, Fernando; Harris, David; Lawley, Trevor D.; Rego, Natalia; Hernández, Martín; Calleros, Lucía; Carretto, Luis; Velilla, Alejandra; Morsella, Claudia; Méndez, Alejandra
Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a sexually transmitted disease distributed worldwide. Campylobacter fetus subsp. venerealis biovar Intermedius strains differ in their biochemical behavior and are prevalent in some countries. We report the first genome sequence for this biovar, isolated from bull prepuce. PMID:23908278
Zerillo, Marcelo Marques; Van Sluys, Marie-Anne; Camargo, Luis Eduardo Aranha; Kitajima, João Paulo
We announce the complete genome sequence of Leifsonia xyli subsp. cynodontis, a vascular pathogen of Bermuda grass. The species also comprises Leifsonia xyli subsp. xyli, a sugarcane pathogen. Since these two subspecies have genome sequences available, a comparative analysis will contribute to our understanding of the differences in their biology and host specificity. PMID:24201198
Gupta, Sushim K.; McMillan, Elizabeth A.; Jackson, Charlene R.; Desai, Prerak T.; Porwollik, Steffen; McClelland, Michael; Hiott, Lari M.; Humayoun, Shaheen B.; Barrett, John B.
Here, we report a 4.78-Mb draft genome sequence of the Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) strain CRJJGF_00165 [also called S. enterica subsp. IIIb serovar 61:k:1,5,(7) strain CRJJGF_00165], isolated from ground beef in 2007. PMID:27881547
Iraola, Gregorio; Pérez, Ruben; Naya, Hugo; Paolicchi, Fernando; Harris, David; Lawley, Trevor D; Rego, Natalia; Hernández, Martín; Calleros, Lucía; Carretto, Luis; Velilla, Alejandra; Morsella, Claudia; Méndez, Alejandra; Gioffre, Andrea
Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a sexually transmitted disease distributed worldwide. Campylobacter fetus subsp. venerealis biovar Intermedius strains differ in their biochemical behavior and are prevalent in some countries. We report the first genome sequence for this biovar, isolated from bull prepuce.
Fontana, C; Cellini, L; Dainelli, B
A new biovar of Staphylococcus aureus subsp. aureus was isolated from human clinical specimens and described on the basis of studies of 12 isolates that were compared with 11 standard reference strains. Both DNA hybridization experiments and numerical taxonomy analysis demonstrated that these strains were strictly related to S. aureus subsp. aureus; however, they were significantly different from the latter. The atypical strains belonging to the new biovar can be distinguished from typical S. aureus subsp. aureus strains by their alpha-chymotrypsin, alpha-glucosidase, beta-N-acetylglucosaminidase, lipase (C-14), and leucine arylamidase enzymatic activities and novobiocin resistance. Thus, the combination of alpha-glucosidase and beta-N-acetyl-glucosaminidase is more useful for distinguishing these S. aureus strains from the other, typical ones. PMID:8370737
Comparative Phenotypic and Molecular Genetic Profiling of Wild Lactococcus lactis subsp. lactis Strains of the L. lactis subsp. lactis and L. lactis subsp. cremoris Genotypes, Isolated from Starter-Free Cheeses Made of Raw Milk▿
Fernández, Elena; Alegría, Ángel; Delgado, Susana; Martín, M. Cruz; Mayo, Baltasar
Twenty Lactococcus lactis strains with an L. lactis subsp. lactis phenotype isolated from five traditional cheeses made of raw milk with no added starters belonging to the L. lactis subsp. lactis and L. lactis subsp. cremoris genotypes (lactis and cremoris genotypes, respectively; 10 strains each) were subjected to a series of phenotypic and genetic typing methods, with the aims of determining their phylogenetic relationships and suitability as starters. Pulsed-field gel electrophoresis (PFGE) analysis of intact genomes digested with SalI and SmaI proved that all strains were different except for three isolates of the cremoris genotype, which showed identical PFGE profiles. Multilocus sequence typing (MLST) analysis using internal sequences of seven loci (namely, atpA, rpoA, pheS, pepN, bcaT, pepX, and 16S rRNA gene) revealed considerable intergenotype nucleotide polymorphism, although deduced amino acid changes were scarce. Analysis of the MLST data for the present strains and others from other dairy and nondairy sources showed that all of them clustered into the cremoris or lactis genotype group, by using both independent and combined gene sequences. These two groups of strains also showed distinctive carbohydrate fermentation and enzyme activity profiles, with the strains in the cremoris group showing broader profiles. However, the profiles of resistance/susceptibility to 16 antibiotics were very similar, showing no atypical resistance, except for tetracycline resistance in three identical cremoris genotype isolates. The numbers and concentrations of volatile compounds produced in milk by the strains belonging to these two groups were clearly different, with the cremoris genotype strains producing higher concentrations of more branched-chain, derived compounds. Together, the present results support the idea that the lactis and cremoris genotypes of phenotypic Lactococcus lactis subsp. lactis actually represent true subspecies. Some strains of the two subspecies
Esteve, Consuelo; Alcaide, Elena; Blasco, María Dolores
Eight Aeromonas hydrophila-like arabinose-negative isolates from diverse sources (i.e., river freshwater, cooling-system water pond, diseased wild European eels, and human stools) sampled in Valencia (Spain) during 2004–2005, were characterized by 16S rRNA gene sequencing and extensive biochemical testing along with reference strains of most Aeromonas species. These isolates and all reference strains of A. hydrophila subsp. dhakensis and A. aquariorum showed a 16S rRNA sequence similarity of 99.8–100%, and they all shared an identical phenotype. This matched exactly with that of A. hydrophila subsp. dhakensis since all strains displayed positive responses to the Voges-Prokauer test and to the use of dl-lactate. This is the first report of A. hydrophila subsp. dhakensis recovered from environmental samples, and further, from its original isolation in India during 1993–1994. This was accurately identified and segregated from other clinical aeromonads (A. hydrophila subsp. hydrophila, A. caviae, A. veronii biovars veronii and sobria, A. trota, A. schubertii and A. jandaei) by using biochemical key tests. The API 20 E profile for all strains included in A. hydrophila subsp. dhakensis was 7047125. The prevalence of this species in Spanish sources was higher for water (9.4%) than for feces (6%) or eels (1.3%). Isolates recovered as pure cultures from diseased eels were moderately virulent (LD50 of 3.3×106 CFU fish−1) to challenged eels in experimental trials. They were all resistant to ticarcillin, amoxicillin-clavuranic acid, cefoxitin, and imipenem, regardless of its source. Our data point to A. hydrophila subsp. dhakensis as an emerging pathogen for humans and fish in temperate countries. PMID:22472298
Levican, Arturo; Lasa, Aide; Irgang, Rute; Romalde, Jesús L; Poblete-Morales, Matías; Avendaño-Herrera, Ruben
A group of seven Chilean isolates presumptively belonging to Vibrio tapetis was isolated from diseased fine flounders (Paralichthys adspersus) and red conger eel (Genypterus chilensis) experimentally reared in Quintay (Chile). All isolates were confirmed as members of V. tapetis on the basis of matrix-assisted laser desorption ionization time-of-flight MS, 16S rRNA gene sequencing, DNA-DNA hybridization values and G+C content. The ERIC-PCR and REP-PCR patterns were homogeneous among those isolates recovered from the same host (red conger or fine flounders), but distinct from the type strains V. tapetis subsp. tapetis CECT 4600T and V. tapetis subsp. britannicus CECT 8161T. On the basis of atpA, rpoA, rpoD, recA and pyrH gene sequence similarities (99.7-100 %) and clustering in the phylogenetic trees, the red conger isolates (Q20, Q047, Q48 and Q50) were confirmed as representing V. tapetis subsp. tapetis. However, they differed from V. tapetis subsp. tapetis CECT 4600T in their lipase, alpha quimiotripsin and non-acid phosphatase production. On the other hand, the fine flounder isolates (QL-9T, QL-35 and QL-41) showed rpoD, recA and pyrH gene sequence similarities ranging from 91.6 to 97.7 % with the type strains of the two V. tapetis subspecies (CECT 4600T and CECT 8161T) and consistently clustered together as an independent phylogenetic line within V. tapetis. Moreover, they could be differentiated phenotypically from strains CECT 4600T and CECT 8161T by nine and three different biochemical tests, respectively. In conclusion, the presence of V. tapetis in diseased red conger eel and fine flounder was demonstrated, extending the known host range and geographical location for this pathogen. Furthermore, this study demonstrates that the three isolates from fine flounder represent a novel subdivision within V. tapetis, for which the name V. tapetis subsp. quintayensis subsp. nov. is proposed and with QL-9T (=CECT 8851T=LMG 28759T) as the type strain. Although QL
Bertin, Clothilde; Pau-Roblot, Corinne; Courtois, Josiane; Manso-Silván, Lucía; Thiaucourt, François; Tardy, Florence; Le Grand, Dominique; Poumarat, François; Gaurivaud, Patrice
Contagious bovine pleuropneumonia is a severe respiratory disease of cattle that is caused by a bacterium of the Mycoplasma genus, namely Mycoplasma mycoides subsp. mycoides (Mmm). In the absence of classical virulence determinants, the pathogenicity of Mmm is thought to rely on intrinsic metabolic functions and specific components of the outer cell surface. One of these latter, the capsular polysaccharide galactan has been notably demonstrated to play a role in Mmm persistence and dissemination. The free exopolysaccharides (EPS), also produced by Mmm and shown to circulate in the blood stream of infected cattle, have received little attention so far. Indeed, their characterization has been hindered by the presence of polysaccharide contaminants in the complex mycoplasma culture medium. In this study, we developed a method to produce large quantities of EPS by transfer of mycoplasma cells from their complex broth to a chemically defined medium and subsequent purification. NMR analyses revealed that the purified, free EPS had an identical β(1−>6)-galactofuranosyl structure to that of capsular galactan. We then analyzed intraclonal Mmm variants that produce opaque/translucent colonies on agar. First, we demonstrated that colony opacity was related to the production of a capsule, as observed by electron microscopy. We then compared the EPS extracts and showed that the non-capsulated, translucent colony variants produced higher amounts of free EPS than the capsulated, opaque colony variants. This phenotypic variation was associated with an antigenic variation of a specific glucose phosphotransferase permease. Finally, we conducted in silico analyses of candidate polysaccharide biosynthetic pathways in order to decipher the potential link between glucose phosphotransferase permease activity and attachment/release of galactan. The co-existence of variants producing alternative forms of galactan (capsular versus free extracellular galactan) and associated with an
Kouonon, Leonie C.; Jacquemart, Anne-Laure; Zoro Bi, Arsene I.; Bertin, Pierre; Baudoin, Jean-Pierre; Dje, Yao
Background and Aims Cucumis melo subsp. agrestis (Cucurbitaceae) is cultivated in many African regions for its edible kernels used as a soup thickener. The plant, an annual, andromonoecious, trailing-vine species, is of high social, cultural and economic value for local communities. In order to improve the yield of this crop, the first step and our aim were to elucidate its breeding system. Methods Eight experimental pollination treatments were performed during three growing seasons to assess spontaneous selfing, self-compatibility and effects of pollen source (hermaphroditic vs. male flowers). Pollination success was determined by pollen tube growth and reproductive success was assessed by fruit, seed and seedling numbers and characteristics. The pollinator guild was surveyed and the pollination distance determined both by direct observations and by indirect fluorescent dye dispersal. Key Results The species is probably pollinated by several Hymenoptera, principally by Hypotrigona para. Pollinator flight distances varied from 25 to 69 cm. No evidence for apomixis or spontaneous self-pollination in the absence of insect visitors was found. The self-fertility index (SFI = 0) indicated a total dependence on pollinators for reproductive success. The effects of hand pollination on fruit set, seed number and seedling fitness differed among years. Pollen tube growth and reproductive success did not differ between self- and cross-pollinations. Accordingly, a high self-compatibility index for the fruit set (SCI = 1·00) and the seed number (SCI = 0·98) and a low inbreeding depression at all developmental stages (cumulative δ = 0·126) suggest a high selfing ability. Finally, pollen origin had no effect on fruit and seed sets. Conclusions This andromonoecious species has the potential for a mixed mating system with high dependence on insect-mediated pollination. The selfing rate through geitonogamy should be important. PMID:19671577
Manca de Nadra, M C; Anduni, G J; Farías, M E
The addition of artificial sweeteners to a LAPT (yeast extract, peptone, and tryptone) medium without supplemented sugar increased the growth rate and final biomass of Lactobacillus delbrueckii subsp. bulgaricus YOP 12 isolated from commercial yogurt. Saccharin and cyclamate were consumed during microorganism growth, while the uptake of aspartame began once the medium was glucose depleted. The pH of the media increased as a consequence of the ammonia released into the media supplemented with the sweeteners. The L. delbrueckii subsp. bulgaricus strain was able to grow in the presence of saccharin, cyclamate, or aspartame, and at low sweetener concentrations, the microorganism could utilize cyclamate and aspartame as an energy and carbon source.
Zito, Pietro; Sajeva, Maurizio; Bruno, Maurizio; Maggio, Antonella; Rosselli, Sergio; Senatore, Felice; Formisano, Carmen
The essential oil of the fruits of Periploca laevigata Aiton subsp. angustifolia (Labill.) Markgraf (Apocynaceae) from Lampedusa Island was obtained by hydrodistillation and its composition was analysed. The analyses allowed the identification and quantification of 64 volatile compounds belonging to different classes. The most abundant compounds were nonacosane, heptacosane, hentriacontane and δ-cadinene. Among the volatile compounds identified in the fruits of P. laevigata subsp. angustifolia, 31 are present in other taxa of Apocynaceae, 19 have antimicrobial activity and four are pheromones for the butterfly Danaus chrysippus. The possible ecological role of the volatile compounds found is briefly discussed.
Emami, Sayyed Ahmad; Abedindo, Bibi Fatemeh; Hassanzadeh-Khayyat, Mohammad
The essential oils of branchlets and fruits of Juniperus excelsa subsp. excelsa and Juniperus excelsa subsp. polycarpos were examined for their antioxidant activity. The compositions of the essential oils were studied by GC and GC-MS. To evaluation the antioxidants activity of the volatile oils, pure components and positive controls at different concentrations, thin-layer chromatography (TLC) screening methods, diphenylpicrylhydrazyl (DPPH) assay, deoxyribose degradation test and modified deoxyribose degradation test were employed. The results of the present study demonstrate some antioxidant activity for the tested essential oils obtained from various parts of both plants. It indicates that the use of these essential oils, in very low concentrations, may be useful as a natural preservative. However before any final conclusion, it is suggested that the antioxidant activity of these oils should also be evaluated by using lipid solvent system methods. PMID:24250416
De Bel, Annelies; Švec, Pavel; Petráš, Petr; Sedláček, Ivo; Pantůček, Roman; Echahidi, Fedoua; Piérard, Denis; Vandamme, Peter
The type and clinical strains of two recently described coagulase-negative species of the genus Staphylococcus, Staphylococcus petrasii and Staphylococcus jettensis, were compared using dnaJ, tuf, gap, hsp60 and rpoB gene sequences, DNA-DNA hybridization, ribotyping, repetitive sequence-based PCR fingerprinting and extensive biochemical characterization. Based on the results, the species description of S. petrasii has been emended and S. jettensis should be reclassified as a novel subspecies within S. petrasii for which the name Staphylococcus petrasii subsp. jettensis subsp. nov. is proposed. The type strain is SEQ110(T) ( = LMG 26879(T) = CCUG 62657(T) = DSM 26618(T) = CCM 8494(T)).
[Comparative susceptibility of Ochrobactrum anthropi, Agrobacterium tumefaciens, Alcaligenes faecalis, Alcaligenes denitrificans subsp. denitrificans, Alcaligenes denitrificans subsp. xylosidans and Bordetella bronchiseptica against 35 antibiotics including 17 beta-lactams].
Bizet, C; Bizet, J
Ochrobactrum anthropi, formerly known as "Achromobacter sp." or CDC group Vd has been isolated from water, hospital environment (antiseptic solutions, dialysis fluids ... ). O. anthropi is a Gram negative, motile, strictly aerobic, oxydase positive and non-fermentative bacteria with a strong urease activity. The susceptibility of 13 strains of O. anthropi was determined by agar diffusion method and compared to those of type strains of Agrobacterium tumefaciens, Alcaligenes faecalis, Alcaligenes denitrificans subsp. denitrificans, Alcaligenes denitrificans subsp. xylosoxydans and Bordetella bronchiseptica. The MICs of 20 antimicrobial agents confirmed the distinct phenotype susceptibility of O. anthropi. All the strains of O. anthropi are sensitive to imipenem, amikacin, gentamicin, netilmicin, nalidixic acid, pefloxacin, ciprofloxacin, tetracyclin, colistin, sulphonamides and rifampicin and resistant to ampicillin, amoxycillin + clavulanic acid, ticarcillin, mezlocillin, cefuroxime, cefamandol, cefoxitin, cefotaxime, cefoperazon, ceftazidime, cefsulodin, aztreonam, streptomycin, kanamycin, pipemidic acid, chloramphenicol, erythromicin, pristinamycin, trimethoprim and fosfomycin. O. anthropi is implicated in nosocomial infections. O. anthropi was the species with the greatest resistance to beta-lactamins.
Csivincsik, Ágnes; Dán, Ádám
Accurate identification of mycobacterial species and subspecies is essential to evaluate their significance and to perform epidemiological studies. The subspecies of Mycobacterium avium have different attributes but coincide in their zoonotic potential. Our knowledge about M. avium subsp. silvaticum is limited, since its identification is uncertain. Mycobacterium avium subsp. avium and M. avium subsp. silvaticum can be discriminated from each other based only on phenotypic characteristics, as they have almost identical genome sequences. Here we describe the development of a diagnostic method which enables the molecular identification of M. avium subsp. silvaticum and discrimination from M. avium subsp. avium based on genomic differences in a duplex high-resolution melt and M. avium subsp. silvaticum-specific mismatch real-time PCR. The developed assay was tested on reference strains and 199 field isolates, which were analyzed by phenotypic methods previously. This assay not only identified all 63 M. avium subsp. silvaticum and 138 M. avium subsp. avium strains correctly but also enabled the detection of mixed M. avium subsp. avium-M. avium subsp. silvaticum cultures. This is the first time that such a large panel of strains has been analyzed, and we also report the first isolation of M. avium subsp. silvaticum from red fox, red deer, wild boar, cattle, and badger. This assay is reliable, rapid, simple, inexpensive, and robust. It eliminates the long-existing problem of ambiguous phenotypic identification and opens up the possibility for detailed and comprehensive strain studies. PMID:25740770
Rónai, Zsuzsanna; Csivincsik, Ágnes; Dán, Ádám
Accurate identification of mycobacterial species and subspecies is essential to evaluate their significance and to perform epidemiological studies. The subspecies of Mycobacterium avium have different attributes but coincide in their zoonotic potential. Our knowledge about M. avium subsp. silvaticum is limited, since its identification is uncertain. Mycobacterium avium subsp. avium and M. avium subsp. silvaticum can be discriminated from each other based only on phenotypic characteristics, as they have almost identical genome sequences. Here we describe the development of a diagnostic method which enables the molecular identification of M. avium subsp. silvaticum and discrimination from M. avium subsp. avium based on genomic differences in a duplex high-resolution melt and M. avium subsp. silvaticum-specific mismatch real-time PCR. The developed assay was tested on reference strains and 199 field isolates, which were analyzed by phenotypic methods previously. This assay not only identified all 63 M. avium subsp. silvaticum and 138 M. avium subsp. avium strains correctly but also enabled the detection of mixed M. avium subsp. avium-M. avium subsp. silvaticum cultures. This is the first time that such a large panel of strains has been analyzed, and we also report the first isolation of M. avium subsp. silvaticum from red fox, red deer, wild boar, cattle, and badger. This assay is reliable, rapid, simple, inexpensive, and robust. It eliminates the long-existing problem of ambiguous phenotypic identification and opens up the possibility for detailed and comprehensive strain studies.
Buňková, Leona; Buňka, František; Pollaková, Eva; Podešvová, Tereza; Dráb, Vladimír
The aim of this work was to study, under model conditions, combined effects of the concentration of lactose (0-1% w/v), NaCl (0-2% w/v) and aero/anaerobiosis on the growth and tyramine production in 3 strains of Lactococcus lactis subsp. lactis and 2 strains of L. lactis subsp. cremoris. The levels of the factors tested were chosen with respect to the conditions which can occur during the real process of natural cheese production, including the culture temperature (10 ± 1°C). In all strains tested, tyrosine decarboxylation was most influenced by NaCl concentration; the highest production of tyramine was obtained within the culture with the highest (2% w/v) salt concentration applied. Two of the strains L. lactis subsp. lactis produced tyramine only in broth with the highest NaCl concentration tested. In the remaining 3 strains of L. lactis, tyramine was detected under all conditions applied. The tested concentration of lactose and aero/anaerobiosis had a less significant effect on tyramine decarboxylation. However, it was also found that at the same concentrations of NaCl and lactose, a higher amount of tyramine was detected under anaerobic conditions. In all strains tested, tyramine decarboxylation started during the active growth phase of the cells.
Le Bourgeois, P; Lautier, M; van den Berghe, L; Gasson, M J; Ritzenthaler, P
A physical and genetic map of the chromosome of the Lactococcus lactis subsp. cremoris reference strain MG1363 was established. The physical map was constructed for NotI, ApaI, and SmaI enzymes by using a strategy that combines creation of new rare restriction sites by the random-integration vector pRL1 and ordering of restriction fragments by indirect end-labeling experiments. The MG1363 chromosome appeared to be circular and 2,560 kb long. Seventy-seven chromosomal markers were located on the physical map by hybridization experiments. Integration via homologous recombination of pRC1-derived plasmids allowed a more precise location of some lactococcal genes and determination of their orientation on the chromosome. The MG1363 chromosome contains six rRNA operons; five are clustered within 15% of the chromosome and transcribed in the same direction. Comparison of the L. lactis subsp. cremoris MG1363 physical map with those of the two L. lactis subsp. lactis strains IL1403 and DL11 revealed a high degree of restriction polymorphism. At the genetic organization level, despite an overall conservation of gene organization, strain MG1363 presents a large inversion of half of the genome in the region containing the rRNA operons. PMID:7751295
El-Naggar, Noura El-Ahmady; Abdelwahed, Nayera A M; Saber, Wesam I A; Mohamed, Asem A
The use of low cost agro-industrial residues for the production of industrial enzymes is one of the ways to reduce significantly production costs. Cellulase producing actinomycetes were isolated from soil and decayed agricultural wastes. Among them, a potential culture, strain NEAE-J, was selected and identified on the basis of morphological, cultural, physiological and chemotaxonomic properties, together with 16S rDNA sequence. It is proposed that strain NEAE-J should be included in the species Streptomyces albogriseolus as a representative of a novel sub-species, Streptomyces albogriseolus subsp. cellulolyticus strain NEAE-J and sequencing product was deposited in the GenBank database under accession number JN229412. This organism was tested for its ability to produce endoglucanase and release reducing sugars from agro-industrial residues as substrates. Sugarcane bagasse was the most suitable substrate for endoglucanase production. Effects of process variables, namely incubation time, temperature, initial pH and nitrogen source on production of endoglucanase by submerged fermentation using Streptomyces albogriseolus subsp. cellulolyticus have been studied. Accordingly optimum conditions have been determined. Incubation temperature of 30 °C after 6 days, pH of 6.5, 1% sugarcane bagasse as carbon source and peptone as nitrogen source were found to be the optimum for endoglucanase production. Optimization of the process parameters resulted in about 2.6 fold increase in the endoglucanase activity. Therefore, Streptomyces albogriseolus subsp. cellulolyticus coud be potential microorganism for the intended application.
Frederick, R D; Chiu, J; Bennetzen, J L; Handa, A K
A mutant of Erwinia carotovora subsp. carotovora, AH2552, created by a Mud1 insertion was found to be reduced in plant pathogenicity and deficient in extracellular protease and cellulase activity, although it produced normal levels of pectate lyase and polygalacturonase. A cosmid clone, pEC462, was isolated from a wild-type E. carotovora subsp. carotovora DNA library that concomitantly restored pathogenicity and protease and cellulase activities of AH2552 to wild-type levels when present in trans. The genetic locus that was disrupted in AH2552 by insertion of Mud1 has been designated rpfA, for regulator of pathogenicity factors. Sequencing of the rpfA region identified an open reading frame of 2,787 bp, and the predicted 929-amino acid polypeptide shared high identity with several two-component sensor-regulator proteins: BarA from Escherichia coli, ApdA from Pseudomonas fluorescens, PheN from P. tolaasii, RepA from P. viridiflava, LemA from P. syringae pv. syringae, and RpfC from Xanthomonas campestris pv. campestris. The RpfA locus described in this study encodes a putative sensor kinase protein that is involved in both extracellular protease and cellulase production and the pathogenicity of E. carotovora subsp. carotovora on potato tubers.
Polyphasic taxonomic revision of the Ralstonia solanacearum species complex: proposal to emend the descriptions of Ralstonia solanacearum and Ralstonia syzygii and reclassify current R. syzygii strains as Ralstonia syzygii subsp. syzygii subsp. nov., R. solanacearum phylotype IV strains as Ralstonia syzygii subsp. indonesiensis subsp. nov., banana blood disease bacterium strains as Ralstonia syzygii subsp. celebesensis subsp. nov. and R. solanacearum phylotype I and III strains as Ralstonia pseudosolanacearum sp. nov.
Safni, Irda; Cleenwerck, Ilse; De Vos, Paul; Fegan, Mark; Sly, Lindsay; Kappler, Ulrike
The Ralstonia solanacearum species complex has long been recognized as a group of phenotypically diverse strains that can be subdivided into four phylotypes. Using a polyphasic taxonomic approach on an extensive set of strains, this study provides evidence for a taxonomic and nomenclatural revision of members of this complex. Data obtained from phylogenetic analysis of 16S-23S rRNA ITS gene sequences, 16S-23S rRNA intergenic spacer (ITS) region sequences and partial endoglucanase (egl) gene sequences and DNA-DNA hybridizations demonstrate that the R. solanacearum species complex comprises three genospecies. One of these includes the type strain of Ralstonia solanacearum and consists of strains of R. solanacearum phylotype II only. The second genospecies includes the type strain of Ralstonia syzygii and contains only phylotype IV strains. This genospecies is subdivided into three distinct groups, namely R. syzygii, the causal agent of Sumatra disease on clove trees in Indonesia, R. solanacearum phylotype IV strains isolated from different host plants mostly from Indonesia, and strains of the blood disease bacterium (BDB), the causal agent of the banana blood disease, a bacterial wilt disease in Indonesia that affects bananas and plantains. The last genospecies is composed of R. solanacearum strains that belong to phylotypes I and III. As these genospecies are also supported by phenotypic data that allow the differentiation of the three genospecies, the following taxonomic proposals are made: emendation of the descriptions of Ralstonia solanacearum and Ralstonia syzygii and descriptions of Ralstonia syzygii subsp. nov. (type strain R 001(T) = LMG 10661(T) = DSM 7385(T)) for the current R. syzygii strains, Ralstonia syzygii subsp. indonesiensis subsp. nov. (type strain UQRS 464(T) = LMG 27703(T) = DSM 27478(T)) for the current R. solanacearum phylotype IV strains, Ralstonia syzygii subsp. celebesensis subsp. nov. (type strain UQRS 627(T
Okagawa, Tomohiro; Konnai, Satoru; Nishimori, Asami; Ikebuchi, Ryoyo; Mizorogi, Seiko; Nagata, Reiko; Kawaji, Satoko; Tanaka, Shogo; Kagawa, Yumiko; Murata, Shiro; Mori, Yasuyuki; Ohashi, Kazuhiko
Johne's disease (paratuberculosis) is a chronic enteritis in cattle that is caused by intracellular infection with Mycobacterium avium subsp. paratuberculosis. This infection is characterized by the functional exhaustion of T-cell responses to M. avium subsp. paratuberculosis antigens during late subclinical and clinical stages, presumably facilitating the persistence of this bacterium and the formation of clinical lesions. However, the mechanisms underlying T-cell exhaustion in Johne's disease are poorly understood. Thus, we performed expression and functional analyses of the immunoinhibitory molecules programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) and lymphocyte activation gene 3 (LAG-3)/major histocompatibility complex class II (MHC-II) in M. avium subsp. paratuberculosis-infected cattle during the late subclinical stage. Flow cytometric analyses revealed the upregulation of PD-1 and LAG-3 in T cells in infected animals, which suffered progressive suppression of interferon gamma (IFN-γ) responses to the M. avium subsp. paratuberculosis antigen. In addition, PD-L1 and MHC-II were expressed on macrophages from infected animals, consistent with PD-1 and LAG-3 pathways contributing to the suppression of IFN-γ responses during the subclinical stages of M. avium subsp. paratuberculosis infection. Furthermore, dual blockade of PD-L1 and LAG-3 enhanced M. avium subsp. paratuberculosis-specific IFN-γ responses in blood from infected animals, and in vitro LAG-3 blockade enhanced IFN-γ production from M. avium subsp. paratuberculosis-specific CD4(+) and CD8(+) T cells. Taken together, the present data indicate that M. avium subsp. paratuberculosis-specific T-cell exhaustion is in part mediated by PD-1/PD-L1 and LAG-3/MHC-II interactions and that LAG-3 is a molecular target for the control of M. avium subsp. paratuberculosis-specific T-cell responses.
Okagawa, Tomohiro; Konnai, Satoru; Nishimori, Asami; Ikebuchi, Ryoyo; Mizorogi, Seiko; Nagata, Reiko; Kawaji, Satoko; Tanaka, Shogo; Kagawa, Yumiko; Murata, Shiro; Mori, Yasuyuki
Johne's disease (paratuberculosis) is a chronic enteritis in cattle that is caused by intracellular infection with Mycobacterium avium subsp. paratuberculosis. This infection is characterized by the functional exhaustion of T-cell responses to M. avium subsp. paratuberculosis antigens during late subclinical and clinical stages, presumably facilitating the persistence of this bacterium and the formation of clinical lesions. However, the mechanisms underlying T-cell exhaustion in Johne's disease are poorly understood. Thus, we performed expression and functional analyses of the immunoinhibitory molecules programmed death-1 (PD-1)/PD-ligand 1 (PD-L1) and lymphocyte activation gene 3 (LAG-3)/major histocompatibility complex class II (MHC-II) in M. avium subsp. paratuberculosis-infected cattle during the late subclinical stage. Flow cytometric analyses revealed the upregulation of PD-1 and LAG-3 in T cells in infected animals, which suffered progressive suppression of interferon gamma (IFN-γ) responses to the M. avium subsp. paratuberculosis antigen. In addition, PD-L1 and MHC-II were expressed on macrophages from infected animals, consistent with PD-1 and LAG-3 pathways contributing to the suppression of IFN-γ responses during the subclinical stages of M. avium subsp. paratuberculosis infection. Furthermore, dual blockade of PD-L1 and LAG-3 enhanced M. avium subsp. paratuberculosis-specific IFN-γ responses in blood from infected animals, and in vitro LAG-3 blockade enhanced IFN-γ production from M. avium subsp. paratuberculosis-specific CD4+ and CD8+ T cells. Taken together, the present data indicate that M. avium subsp. paratuberculosis-specific T-cell exhaustion is in part mediated by PD-1/PD-L1 and LAG-3/MHC-II interactions and that LAG-3 is a molecular target for the control of M. avium subsp. paratuberculosis-specific T-cell responses. PMID:26483406
Wigmore, Sarah M.; Wareham, David W.
ABSTRACT Staphylococcus cohnii subsp. urealyticus strain SW120 was isolated from the ear swab of a healthy dog. The isolate is resistant to methicillin and fusidic acid. The SW120 draft genome is 2,805,064 bp and contains 2,667 coding sequences, including 58 tRNAs and nine complete rRNA coding regions. PMID:28209829
Raphael, Brian H; Kozak-Muiznieks, Natalia A; Morrison, Shatavia S; Mercante, Jeffrey W; Winchell, Jonas M
We report here the complete genome sequences of two of the earliest known strains of Legionella pneumophila subsp. fraseri Detroit-1 is serogroup 1 and was isolated from a lung biopsy specimen in 1977. Dallas 1E is serogroup 5 and was isolated in 1978 from a cooling tower.
Johne’s disease is a chronic granulomatous enteritis characterized by severe diarrhea, wasting, and a decline in milk production caused by the bacterium Mycobacterium avium subsp. paratuberculosis (MAP). The vaccine currently on the market has some limitations including a severe injection site react...
Johne’s disease is a chronic granulomatous enteritis characterized by severe diarrhea, wasting and a decline in milk production caused by the bacterium Mycobacterium avium subsp. paratuberculois (MAP). The vaccine currently on the market has some limitations including a severe injection site reactio...
Kaup, Olaf; Gräfen, Ines; Zellermann, Eva-Maria; Eichenlaub, Rudolf; Gartemann, Karl-Heinz
The insertion site of a transposon mutant of Clavibacter michiganensis subsp. michiganensis NCPPB382 was cloned and found to be located in the gene tomA encoding a member of the glycosyl hydrolase family 10. The intact gene was obtained from a cosmid library of C. michiganensis subsp. michiganensis. The deduced protein TomA (543 amino acids, 58 kDa) contains a predicted signal peptide and two domains, the N-terminal catalytic domain and a C-terminal fibronectin III-like domain. The closest well-characterized relatives of TomA were tomatinases from fungi involved in the detoxification of the tomato saponin alpha-tomatine which acts as a growth inhibitor. Growth inhibition of C. michiganensis subsp. michiganensis by alpha-tomatine was stronger in the tomA mutants than in the wild type. Tomatinase activity assayed by deglycosylation of alpha-tomatine to tomatidine was demonstrated in concentrated culture supernatants of C. michiganensis subsp. michiganensis. No activity was found with the tomA mutants. However, neither the transposon mutant nor a second mutant constructed by gene disruption was affected in virulence on the tomato cv. Moneymaker.
In this study we investigated an iron dependent regulator (IdeR) of Mycobacterium avium subsp. paratuberculosis (MAP). IdeR is a transcriptional factor that plays a global iron regulatory role in Mycobacterium tuberculosis (MTB) with a 19-bp recognition sequence. IdeR recognition sites within MAP ge...
Citrus canker (caused by Xanthomonas citri subsp. citri, Xcc) is a serious disease of susceptible citrus in Florida and other citrus-growing areas of the world. The effect of leaf preconditioning as a route for entry of the bacteria is poorly characterized. A series of experiments were designed to i...
del Rio, Beatriz; Linares, Daniel M.; Fernandez, María; Mayo, Baltasar; Martín, M. Cruz
We report here the 2,576,542-bp genome annotated draft assembly sequence of Lactococcus lactis subsp. lactis 1AA59. This strain—isolated from a traditional cheese—produces putrescine, one of the most frequently biogenic amines found in dairy products. PMID:26089428
Fazal, Mohammed-Abbas; Alexander, Sarah; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Parkhill, Julian; Russell, Julie E
Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939.
Fazal, Mohammed-Abbas; Burnett, Edward; Deheer-Graham, Ana; Oliver, Karen; Holroyd, Nancy; Russell, Julie E.
Salmonellae are a significant cause of morbidity and mortality globally. Here, we report the first complete genome sequence for Salmonella enterica subsp. enterica serovar Java strain NCTC5706. This strain is of historical significance, having been isolated in the pre-antibiotic era and was deposited into the National Collection of Type Cultures in 1939. PMID:27811100
Xylella fastidiosa subsp. fastidiosa causes Pierce’s disease of grapevine. Presented here is the draft genome sequence of the Stag’s Leap strain, previously used in pathogenicity/virulence assays to evaluate grapevine germplasm bearing Pierce’s disease....
Klar, G T; Stalnaker, C B
1. Electrophoretic variation observed in muscle A group lactate dehydrogenase in Snake Valley cutthroat trout (Salmo clarki subsp.) suggested the presence of two variant alleles at the A1 locus and a null allele at the A2 locus. 2. The taxonomic status of the Snake Valley cutthroat trout was reviewed.
Cows in advanced stages of Johne’s disease shed Mycobacterium avium subsp. paratuberculosis (MAP) into both their milk and feces, allowing for transmission of the bacteria between animals. The objective of this study was to formulate an optimized protocol for the isolation of MAP from milk and colos...
Background: Mycobacterium avium subsp. paratuberculosis persistently infect intestines and mesenteric lymph nodes leading to a prolonged subclinical disease. We investigated the intracellular lifestyle of MAP in the intestines and lymph nodes to understand the MAP pathways that function to govern th...
Background: Two genotypically and microbiologically distinct strains of Mycobacterium avium subsp. paratuberculosis (MAP) exist – the type I and type II strains that primarily infect sheep and cattle, respectively. Concentration of iron in the cultivation medium has been suggested as one contributin...
Gagnon, Mérilie; Savard, Patricia; Rivière, Audrey; LaPointe, Gisèle
Bifidobacterium longum subsp. longum is among the dominant species of the human gastrointestinal microbiota and could thus have potential as probiotics. New targets such as antioxidant properties have interest for beneficial effects on health. The objective of this study was to evaluate the bioaccessibility of antioxidants in milk fermented by selected B. longum subsp. longum strains during in vitro dynamic digestion. The antioxidant capacity of cell extracts from 38 strains, of which 32 belong to B. longum subsp. longum, was evaluated with the ORAC (oxygen radical absorbance capacity) method. On the basis of screening and gene sequence typing by multilocus locus sequence analysis (MLSA), five strains were chosen for fermenting reconstituted skim milk. Antioxidant capacity varied among the strains tested (P = 0.0009). Two strains of B. longum subsp. longum (CUETM 172 and 171) showed significantly higher ORAC values than the other bifidobacteria strains. However, there does not appear to be a relationship between gene sequence types and antioxidant capacity. The milk fermented by each of the five strains selected (CUETM 268, 172, 245, 247, or PRO 16-10) did not have higher initial ORAC values compared to the nonfermented milk samples. However, higher bioaccessibility of antioxidants in fermented milk (175–358%) was observed during digestion. PMID:25802836
Phung, Le T; Trimble, William L; Meyer, Folker; Gilbert, Jack A; Silver, Simon
Alcaligenes faecalis subsp. faecalis NCIB 8687, the betaproteobacterium from which arsenite oxidase had its structure solved and the first "arsenate gene island" identified, provided a draft genome of 3.9 Mb in 186 contigs (with the largest 15 comprising 90% of the total) for this opportunistic pathogen species.
Negro, C; Notarnicola, S; De Bellis, L; Miceli, A
The essential oil of 46 spontaneous plants of Calamintha nepeta (L.) Savi subsp. nepeta growing wild in Sud, Italy (Salento, Apulia), were investigated by GC/MS. Fifty-seven components were identified in the oil representing over the 98% of the total oil composition. Four chemotypes were identified: piperitone oxide, piperitenone oxide, piperitone-menthone and pulegone.
Spinard, Edward J.; Dubert, Javier; Gomez-Chiarri, Marta; Barja, Juan L.
Vibrio tubiashii subsp. europaeus is a bivalve pathogen isolated during episodes of mortality affecting larval cultures in different shellfish hatcheries. Here, we announce the draft genome sequence of the type strain PP-638 and describe potential virulence factors, which may provide insight into the mechanism of pathogenicity. PMID:27469949
Raphael, Brian H.; Kozak-Muiznieks, Natalia A.; Morrison, Shatavia S.; Mercante, Jeffrey W.
ABSTRACT We report here the complete genome sequences of two of the earliest known strains of Legionella pneumophila subsp. fraseri. Detroit-1 is serogroup 1 and was isolated from a lung biopsy specimen in 1977. Dallas 1E is serogroup 5 and was isolated in 1978 from a cooling tower. PMID:28153889
Merino, Susana; Tomás, Juan M
Initial hydridization tests using Aeromonas salmonicida typical and atypical strains showed the possibility of different lipopolysaccharide (LPS) outer cores among these strains. By chemical structural analysis, LPS-core SDS-PAGE gel migration, and functional and comparative genomics we demonstrated that typical A. salmonicida (subsp. salmonicida) strains and atypical subsp. masoucida and probably smithia strains showed the same LPS outer core. A. salmonicida subsp. achromogenes strains show a similar LPS outer core but lack one of the most external residues (a galactose linked α1-6 to heptose), not affecting the O-antigen LPS linkage. A. salmonicida subsp. pectinolytica strains show a rather changed LPS outer core, which is identical to the LPS outer core from the majority of the A. hydrophila strains studied by genomic analyses. The LPS inner core in all tested A. salmonicida strains, typical and atypical, is well-conserved. Furthermore, the LPS inner core seems to be conserved in all the Aeromonas (psychrophilic or mesophilic) strains studied by genomic analyses.
Methods to improve the ELISA test to detect Mycobacterium avium subsp paratuberculosis have been explored over several years. Previously, selected recombinant proteins of M. avium subspecies paratuberculosis were found to be immunogenic in cattle with Johne’s disease. In the present study, antibo...
Haley, Bradd J; Pirone, Cary; Muruvanda, Tim; Brown, Eric; Allard, Marc; Karns, Jeffrey S; Van Kessel, Jo Ann S
Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome of isolate CFSAN001588 was fully sequenced and deposited in the GenBank database.
ABSTRACT We present here the 5.561-Mbp assembled draft genome sequence of Klebsiella pneumoniae subsp. pneumoniae ATCC 9621, a phosphite- and organophosphonate-assimilating Gammaproteobacterium. The genome harbors 5,179 predicted protein-coding genes. PMID:28336608
Environmental contamination with Mycobacterium avium subsp. paratuberculosis (MAP) is thought to be the primary source of infection for dairy cattle. The exact link between fecal shedding of MAP by individual cows and environmental contamination levels at the herd level was explored with a cross-se...
Asgary, S.; Naderi, G.A.; Shams Ardekani, M.R.; Sahebkar, A.; Airin, A.; Aslani, S.; Kasher, T.; Emami, S.A.
Oxidative stress and protein glycation play pivotal roles in the pathophysiology of diabetes mellitus and its vascular complications. The present study aimed to investigate the anti-glycation properties of essential oils obtained from different parts of Juniperus communis subsp. hemisphaerica. The branchlets of male tree (BMT) and branchlets of female (BFT) tree, and fruits of J. communis subsp. hemisphaerica were extracted using steam distillation method. The oils were phytochemically analyzed using gas chromatography-mass spectrometry. Anti-glycation properties were evaluated using hemoglobin and insulin glycation assays. Overall, 18 volatile components were identified in the J. communis subsp. hemisphaerica oils, amounting to 82.1%, 100.0% and 96.4% of the BMT, BFT and fruit oils, respectively. Promising inhibitory activity was observed from all concentrations of the tested oils in the hemoglobin and insulin glycation assays. The inhibitory activities peaked to 89.9% (BFT oil; 200 μg mL-1) and 81.0% (BFT oil; 600 μg mL-1) in the hemoglobin and insulin glycation assays, respectively. The evidence from this study suggests that essential oils obtained from the fruits and branchlets of J. communis subsp. hemisphaerica possess anti-glycation properties. These activities may find implication for the prevention and treatment of diabetic complications. PMID:25657787
Ratoon stunt, caused by the xylem-limited coryneform bacterium Leifsonia xyli subsp. xyli (Lxx), is prevalent in most sugarcane-planting countries. Because the disease does not cause characteristic external symptoms, a laboratory-based technique is needed for accurate diagnosis. Based on loop-mediat...
Infection models are useful for studying host responses to infection to aid in the development of diagnostic tools and vaccines. The majority of experimental models for ruminants have utilized an oral inoculation of live Mycobacterium avium subsp. paratuberculosis (MAP) in order to establish infecti...
Animal models are useful for studying host responses to infection and aid in the development of diagnostic tools and vaccines. The current study was designed to compare the effects of different methods of experimental infection: Oral (Mycobacterium avium subsp. parauberculosis (MAP) strain K-10; Or...
Animal models are useful for studying host responses to infection and aid in the development of diagnostic tools and vaccines. The current study was designed to compare the effects of different methods of experimental infection: Oral (Mycobacterium avium subsp. parauberculosis (MAP) strain K-10; Or...
Understanding the infection process to Mycobacterium avium subsp. paratuberculosis is tantamount to the development of effective vaccines and therapeutics for the control of this disease in the field. The current study compared the effectiveness of oral and intraperitoneal methods of experimental in...
Ratoon stunt, caused by the xylem-limited coryneform bacterium Leifsonia xyli subsp. xyli (Lxx), is prevalent in most sugarcane-producing countries. Because the disease does not cause characteristic external symptoms, a laboratory-based technique is needed for accurate diagnosis. We developed a diag...
Breurec, Sebastien; Melot, Benedicte; Hoen, Bruno; Passet, Virginie; Schepers, Kinda; Bastian, Sylvaine; Brisse, Sylvain
We report a case of pyogenic liver abscess caused by community-acquired Klebsiella quasipneumoniae subsp. quasipneumoniae. The infecting isolate had 2 prominent features of hypervirulent K. pneumoniae strains: the capsular polysaccharide synthesis region for K1 serotype and the integrative and conjugative element ICEKp1, which encodes the virulence factors yersiniabactin, salmochelin, and RmpA.
Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of Johne’s disease, a chronic enteric disease of ruminant animals. In the present study, blue native PAGE electrophoresis and 2D SDS-PAGE were used to separate MAP envelope protein complexes, followed by mass spectrometry (MS) ...
Johne’s disease in ruminants is a chronic infection of the intestines caused by Mycobacterium avium subsp. paratuberculosis. Economic losses associated with Johne’s disease arise due to premature culling, reduced production of milk and wool and mortalities. The disease is characterised by a long inc...
Johne’s disease (JD) is a chronic enteric infection of cattle caused by Mycobacterium avium subsp. paratuberculosis (MAP). The high economic cost and potential zoonotic threat of JD have driven efforts to develop tools and approaches to effectively manage this disease within livestock herds. Efforts...
Guellerin, Maéva; Passerini, Delphine; Fontagné-Faucher, Catherine; Robert, Hervé; Gabriel, Valérie; Loux, Valentin; Klopp, Christophe; Le Loir, Yves; Coddeville, Michèle; Daveran-Mingot, Marie-Line; Ritzenthaler, Paul
We report here the complete genome sequence of Lactococcus lactis subsp. lactis strain A12, a strain isolated from sourdough. The circular chromosome and the four plasmids reveal genes involved in carbohydrate metabolism that are potentially required for the persistence of this strain in such a complex ecosystem. PMID:27634985
Guellerin, Maéva; Passerini, Delphine; Fontagné-Faucher, Catherine; Robert, Hervé; Gabriel, Valérie; Loux, Valentin; Klopp, Christophe; Le Loir, Yves; Coddeville, Michèle; Daveran-Mingot, Marie-Line; Ritzenthaler, Paul; Le Bourgeois, Pascal
We report here the complete genome sequence of Lactococcus lactis subsp. lactis strain A12, a strain isolated from sourdough. The circular chromosome and the four plasmids reveal genes involved in carbohydrate metabolism that are potentially required for the persistence of this strain in such a complex ecosystem.
McNamara, Michael; Tzeng, Shin-Cheng; Maier, Claudia; Zhang, Li
“Mycobacterium avium subsp. hominissuis” is a robust and pervasive environmental bacterium that can cause opportunistic infections in humans. The bacterium overcomes the host immune response and is capable of surviving and replicating within host macrophages. Little is known about the bacterial mechanisms that facilitate these processes, but it can be expected that surface-exposed proteins play an important role. In this study, the selective biotinylation of surface-exposed proteins, streptavidin affinity purification, and shotgun mass spectrometry were used to characterize the surface-exposed proteome of M. avium subsp. hominissuis. This analysis detected more than 100 proteins exposed at the bacterial surface of M. avium subsp. hominissuis. Comparisons of surface-exposed proteins between conditions simulating early infection identified several groups of proteins whose presence on the bacterial surface was either constitutive or appeared to be unique to specific culture conditions. This proteomic profile facilitates an improved understanding of M. avium subsp. hominissuis and how it establishes infection. Additionally, surface-exposed proteins are excellent targets for the host adaptive immune system, and their identification can inform the development of novel treatments, diagnostic tools, and vaccines for mycobacterial disease. PMID:22392927
Mycobacterium avium subsp. paratuberculosis (MAP) causes Johne’s disease in domestic animals and has been implicated in Crohn’s disease in humans. Cows infected with Johne’s disease shed large quantities of MAP into soil. Further, MAP has been isolated from surface water, is resi...
The rhizosphere isolated bacteria belonging to the Bacillus amyloliquefaciens subsp. plantarum and Bacillus methylotrophicus clades are an important group of strains that are used as plant growth promoters and antagonists of plant pathogens. These properties have made these strains the focus of comm...
Johne’s disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is estimated to infect more than 22% of US dairy herds. Periods of immunosuppression, typically seen at parturition, may contribute to the transition from the subclinical, or asymptomatic, to the clinical stage of inf...
Acidovorax avenae subsp. citrulli (Aac), the causal agent of a watermelon seedling blight and fruit blotch (WFB), has emerged as a serious seedborne pathogen of watermelon, melons, pumpkin, and citron. Although attempts have been made to develop a simple routine laboratory seed assay to detect the...
Ho, Yung S; Adroub, Sabir A; Aleisa, Fajr; Mahmood, Hanan; Othoum, Ghofran; Rashid, Fahad; Zaher, Manal; Ali, Shahjahan; Bitter, Wilbert; Pain, Arnab; Abdallah, Abdallah M
Mycobacterium fortuitum is a member of the rapidly growing nontuberculous mycobacteria (NTM). It is ubiquitous in water and soil habitats, including hospital environments. M. fortuitum is increasingly recognized as an opportunistic nosocomial pathogen causing disseminated infection. Here we report the genome sequence of M. fortuitum subsp. fortuitum type strain DSM46621.
Wu, F.; Zheng, Z.; Deng, X.; Burbank, L. P.; Stenger, D. C.
Xylella fastidiosa subsp. fastidiosa causes Pierce’s disease of grapevine. Presented here is the draft genome sequence of the Stag’s Leap strain, previously used in pathogenicity/virulence assays to evaluate grapevine germplasm bearing Pierce’s disease resistance and a phenotypic assessment of knockout mutants to determine gene function. PMID:27103713
Conditioned food aversion is a technique that can be used to train livestock to avoid ingestion of poisonous plants. This study tested the efficacy and durability of conditioned food aversion to eliminate goat’s consumption of Ipomoea carnea subsp. fistulosa. We used 14 young Moxotó goats, which wer...
Fecal culture is considered the gold standard for the diagnostics of paratuberculosis, however, PCR for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in fecal material is widely used today, having demonstrated great sensitivity and specificity. To insure the most efficient and r...
Fecal culture is considered the gold standard for the diagnosis of paratuberculosis, however, PCR for the detection of Mycobacterium avium subsp. paratuberculosis (MAP) in fecal material is widely used today, having demonstrated great sensitivity and specificity. To insure the most efficient and rep...
Citrus canker control is based on protection measures and eradication of plants infected with Xanthomonas citri subsp. citri. Although these measures show satisfactory results, the use of resistant genotypes is an important alternative for citrus canker control. The aim of this study was to evaluate...
Alikhanian, S I; Ryabchenko, N F; Bukanov, N O; Sakanyan, V A
Protoplasts of the entomopathogenic bacterium Bacillus thuringiensis subsp. galleria were transformed by plasmid pBC16. The frequency of transformation was much lower than that of Bacillus subtilis. All isolated B. thuringiensis transformants were characterized by increased sensitivity to lysozyme as compared with the original strain. Images PMID:7217007
Aslim, Belma; Onal, Derya; Beyatli, Yavuz
Of 26 Lactobacillus delbrueckii subsp. bulgaricus strains isolated from yogurt, strains B2 and 22, which produce low levels (28 and 21 mg liter(-1), respectively) of extracellular polysaccharides (EPSs), and strains B3 and G12, which produce high EPS levels (211 and 175 mg liter(-1), respectively), were selected for further study. The two high EPS-producing strains showed a significant autoaggregation and coaggregation ability with Escherichia coli ATCC 11230 (P < 0.05). Moreover, the effect of bile was evaluated on autoaggregation and hydrophobicity. Autoaggregation and hydrophobicity of these L. delbrueckii subsp. bulgaricus strains decreased after treatment with bile. Only the high EPS-producing L. delbrueckii subsp. bulgaricus strain B3 showed greater autoaggregation (80%) and hydrophobicity (86%) than the other strains after bile treatment. When these strains were assessed for the inhibition of E. coli ATCC 11230 in coculture, L. delbrueckii subsp. bulgaricus B3 completely inhibited E. coli during 24 and 48 h of incubation. This investigation showed that a high EPS production and coaggregation ability may be important in the selection of probiotic strains.
Despite the ubiquitous occurrence of Mycobacterium sp. in nature and the fact that Johne’s disease has been reported worldwide, little research has been done to assess the survival of Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) in agricultural environments. The goal of this stu...
Benahmed, Faiza H.; Gopinath, Gopal R.; Wang, Hua; Jean-Gilles Beaubrun, Junia; Grim, Christopher; Cheng, Chorng-Ming; McClelland, Michael; Ayers, Sherry; Abbott, Jason; Desai, Prerak; Frye, Jonathan G.; Weinstock, George; Hammack, Thomas S.; Hanes, Darcy E.; Rasmussen, Mark A.
We report the draft genomes of Salmonella enterica subsp. enterica serovar Cubana strain CVM42234, isolated from chick feed in 2012, and S. Cubana strain 76814, isolated from swine in 2004. The genome sizes are 4,975,046 and 4,936,251 bp, respectively. PMID:24459266
Pooley, Hannah B.; de Silva, Kumudika; Purdie, Auriol C.; Begg, Douglas J.; Whittington, Richard J.
ABSTRACT Determining the viability of bacteria is a key outcome of in vitro cellular infection assays. Currently, this is done by culture, which is problematic for fastidious slow-growing bacteria such as Mycobacterium avium subsp. paratuberculosis, where it can take up to 4 months to confirm growth. This study aimed to identify an assay that can rapidly quantify the number of viable M. avium subsp. paratuberculosis cells in a cellular sample. Three commercially available bacterial viability assays along with a modified liquid culture method coupled with high-throughput quantitative PCR growth detection were assessed. Criteria for assessment included the ability of each assay to differentiate live and dead M. avium subsp. paratuberculosis organisms and their accuracy at low bacterial concentrations. Using the culture-based method, M. avium subsp. paratuberculosis growth was reliably detected and quantified within 2 weeks. There was a strong linear association between the 2-week growth rate and the initial inoculum concentration. The number of viable M. avium subsp. paratuberculosis cells in an unknown sample was quantified based on the growth rate, by using growth standards. In contrast, none of the commercially available viability assays were suitable for use with samples from in vitro cellular infection assays. IMPORTANCE Rapid quantification of the viability of Mycobacterium avium subsp. paratuberculosis in samples from in vitro cellular infection assays is important, as it allows these assays to be carried out on a large scale. In vitro cellular infection assays can function as a preliminary screening tool, for vaccine development or antimicrobial screening, and also to extend findings derived from experimental animal trials. Currently, by using culture, it takes up to 4 months to obtain quantifiable results regarding M. avium subsp. paratuberculosis viability after an in vitro infection assay; however, with the quantitative PCR and liquid culture method
Mikalová, Lenka; Strouhal, Michal; Oppelt, Jan; Grange, Philippe Alain; Janier, Michel; Benhaddou, Nadjet; Dupin, Nicolas; Šmajs, David
Background Treponema pallidum subsp. endemicum (TEN) is the causative agent of endemic syphilis (bejel). An unusual human TEN 11q/j isolate was obtained from a syphilis-like primary genital lesion from a patient that returned to France from Pakistan. Methodology/Principal findings The TEN 11q/j isolate was characterized using nested PCR followed by Sanger sequencing and/or direct Illumina sequencing. Altogether, 44 chromosomal regions were analyzed. Overall, the 11q/j isolate clustered with TEN strains Bosnia A and Iraq B as expected from previous TEN classification of the 11q/j isolate. However, the 11q/j sequence in a 505 bp-long region at the TP0488 locus was similar to Treponema pallidum subsp. pallidum (TPA) strains, but not to TEN Bosnia A and Iraq B sequences, suggesting a recombination event at this locus. Similarly, the 11q/j sequence in a 613 bp-long region at the TP0548 locus was similar to Treponema pallidum subsp. pertenue (TPE) strains, but not to TEN sequences. Conclusions/Significance A detailed analysis of two recombinant loci found in the 11q/j clinical isolate revealed that the recombination event occurred just once, in the TP0488, with the donor sequence originating from a TPA strain. Since TEN Bosnia A and Iraq B were found to contain TPA-like sequences at the TP0548 locus, the recombination at TP0548 took place in a treponeme that was an ancestor to both TEN Bosnia A and Iraq B. The sequence of 11q/j isolate in TP0548 represents an ancestral TEN sequence that is similar to yaws-causing treponemes. In addition to the importance of the 11q/j isolate for reconstruction of the TEN phylogeny, this case emphasizes the possible role of TEN strains in development of syphilis-like lesions. PMID:28263990
Osteopontin (Opn), a highly acidic glycoprotein, promotes cellular adhesion and recruitment and has been shown to be upregulated in the granulomas of mycobacterial infections. Johne’s disease, caused by Mycobacterium avium subsp. paratuberculosis (MAP), is associated with granulomatous enteritis. ...
Kaevska, Marija; Videnska, Petra; Sedlar, Karel; Bartejsova, Iva; Kralova, Alena; Slana, Iva
The aim of this study was to determine possible differences in the faecal microbiota of dairy cows infected with Mycobacterium avium subsp. paratuberculosis (Johne's disease) in comparison with noninfected cows from the same herds. Faecal samples from cows in 4 herds were tested for M. avium subsp. paratuberculosis by real-time PCR, and faecal bacterial populations were analysed by 454 pyrosequencing of the 16S rRNA gene. The most notable differences between shedding and nonshedding cows were an increase in the genus Psychrobacter and a decrease in the genera Oscillospira, Ruminococcus, and Bifidobacterium in cows infected with M. avium subsp. paratuberculosis. The present study is the first to report the faecal microbial composition in dairy cows infected with M. avium subsp. paratuberculosis.
Kozak-Muiznieks, Natalia A.; Morrison, Shatavia S.; Sammons, Scott; Rowe, Lori A.; Sheth, Mili; Frace, Michael; Lucas, Claressa E.; Loparev, Vladimir N.; Raphael, Brian H.
Here, we report the complete genome sequences of three Legionella pneumophila subsp. pascullei strains (including both serogroup 1 and 5 strains) that were found in the same health care facility in 1982 and 2012. PMID:27151801
Casteñeda-Ruelas, Gloria M; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra; Jiménez-Edeza, Maribel
Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S Oranienburg strains isolated from rivers in the northwestern region of Mexico.
Estrada-Acosta, Mitzi; Medrano-Félix, Andrés; Jiménez, Maribel; Gómez-Gil, Bruno; León-Félix, Josefina; Amarillas, Luis
Salmonella is a pathogen of worldwide importance, causing disease in a vast range of hosts, including humans. We report the genome sequence of Salmonella enterica subsp. enterica serotype Saintpaul strain S-70, isolated from an aquatic environment. PMID:24336367
Osteopontin (Opn), an important mediator of the cell-mediated immune response, enhances the host immune response against mycobacterial infections. Infections caused by the intracellular bacterium, Mycobacterium avium subsp. paratuberculosis (MAP), have a devastating impact on the dairy industry. ...
Draper, Lorraine A.; Tagg, John R.; Ross, R. Paul
Nisin U is a member of the extended nisin family of lantibiotics. Here we identify the presence of nisin U immunity gene homologues in Streptococcus infantarius subsp. infantarius BAA-102. Heterologous expression of these genes in Lactococcus lactis subsp. cremoris HP confers protection to nisin U and other members of the nisin family, thereby establishing that the recently identified phenomenon of resistance through immune mimicry also occurs with respect to nisin. PMID:22064537
Forde, Taya; De Buck, Jeroen; Elkin, Brett; Kutz, Susan; van der Meer, Frank; Orsel, Karin
Reduced to near extinction in the late 1800s, a number of wood bison populations (Bison bison athabascae) have been re-established through reintroduction initiatives. Although an invaluable tool for conservation, translocation of animals can spread infectious agents to new areas or expose animals to pathogens in their new environment. Mycobacterium avium subsp. paratuberculosis, a bacterium that causes chronic enteritis in ruminants, is among the pathogens of potential concern for wood bison management and conservation. In order to inform translocation decisions, our objectives were to determine the M. avium subsp. paratuberculosis infection status of wood bison herds in Canada and to culture and genetically characterize the infective strain(s). We tested fecal samples from bison (n = 267) in nine herds using direct PCR for three M. avium subsp. paratuberculosis-specific genetic targets with different copy numbers within the M. avium subsp. paratuberculosis genome. Restriction enzyme analysis (REA) and sequencing of IS1311 were performed on seven samples from five different herds. We also evaluated a panel of different culture conditions for their ability to support M. avium subsp. paratuberculosis growth from feces and tissues of direct-PCR-positive animals. Eighty-one fecal samples (30%) tested positive using direct IS900 PCR, with positive samples from all nine herds; of these, 75% and 21% were also positive using ISMAP02 and F57, respectively. None of the culture conditions supported the growth of M. avium subsp. paratuberculosis from PCR-positive samples. IS1311 REA and sequencing indicate that at least two different M. avium subsp. paratuberculosis strain types exist in Canadian wood bison. The presence of different M. avium subsp. paratuberculosis strains among wood bison herds should be considered in the planning of translocations.
Draper, Lorraine A; Tagg, John R; Hill, Colin; Cotter, Paul D; Ross, R Paul
Nisin U is a member of the extended nisin family of lantibiotics. Here we identify the presence of nisin U immunity gene homologues in Streptococcus infantarius subsp. infantarius BAA-102. Heterologous expression of these genes in Lactococcus lactis subsp. cremoris HP confers protection to nisin U and other members of the nisin family, thereby establishing that the recently identified phenomenon of resistance through immune mimicry also occurs with respect to nisin.
Sugar beet deterioration can still be a major technological constraint in processing. The major (but not sole) contributor to deterioration in many countries, particularly when warm and humid conditions prevail, is infection by hetero-fermentative Leuconostoc mesenteroides lactic acid bacteria. In...
Mannitol is a major deterioration product of Leuconstoc mesenteroides bacterial deterioration of both sugarcane and sugar beet. The effect of crystallization conditions on the mannitol partition coefficient (Keff) between impure sucrose syrup and crystal has been investigated in a batch laboratory c...
Mannitol, formed mainly by Leuconostoc mesenteroides bacteria, is a very sensitive indicator of sugarcane deterioration that can predict processing problems. A rapid (4 to 7 min) enzymatic method has been developed to measure mannitol in juice pressed from consignments of sugarcane delivered to the...
Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...
Biofilms, composed of extra-cellular polymers secreted by bacteria, have been observed to both increase as well as decrease the rate of metal corrosion. Exopolysaccharides derived from Leuconostoc mesenteroides cultures have been shown to inhibit corrosion on corrosion-sensitive metals. The substa...
The activity of blue light (470nm) alone on (1) bacterial viability, and (2) with a food grade photosensitizer on filamentous fungal viability, was studied. Suspensions of the bacteria Leuconostoc mesenteroides (LM), Bacillus atrophaeus (BA), and Pseudomonas aeruginosa (PA) were prepared and aliquo...
Ghosh, Pallab; Steinberg, Howard; Talaat, Adel M
Mycobacterium avium subsp. paratuberculosis causes Johne's disease in ruminants, a chronic enteric disease responsible for severe economic losses in the dairy industry. Global gene regulators, including sigma factors are important in regulating mycobacterial virulence. However, the biological significance of such regulators in M. avium subsp. paratuberculosis rremains elusive. To better decipher the role of sigma factors in M. avium subsp. paratuberculosis pathogenesis, we targeted a key sigma factor gene, sigL, activated in mycobacterium-infected macrophages. We interrogated an M. avium subsp. paratuberculosis ΔsigL mutant against a selected list of stressors that mimic the host microenvironments. Our data showed that sigL was important in maintaining bacterial survival under such stress conditions. Survival levels further reflected the inability of the ΔsigL mutant to persist inside the macrophage microenvironments. Additionally, mouse infection studies suggested a substantial role for sigL in M. avium subsp. paratuberculosis virulence, as indicated by the significant attenuation of the ΔsigL-deficient mutant compared to the parental strain. More importantly, when the sigL mutant was tested for its vaccine potential, protective immunity was generated in a vaccine/challenge model of murine paratuberculosis. Overall, our study highlights critical role of sigL in the pathogenesis and immunity of M. avium subsp. paratuberculosis infection, a potential role that could be shared by similar proteins in other intracellular pathogens.
Mendes, Filipa; Sieuwerts, Sander; de Hulster, Erik; Almering, Marinka J H; Luttik, Marijke A H; Pronk, Jack T; Smid, Eddy J; Bron, Peter A; Daran-Lapujade, Pascale
Mixed populations of Saccharomyces cerevisiae yeasts and lactic acid bacteria occur in many dairy, food, and beverage fermentations, but knowledge about their interactions is incomplete. In the present study, interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus, two microorganisms that co-occur in kefir fermentations, were studied during anaerobic growth on lactose. By combining physiological and transcriptome analysis of the two strains in the cocultures, five mechanisms of interaction were identified. (i) Lb. delbrueckii subsp. bulgaricus hydrolyzes lactose, which cannot be metabolized by S. cerevisiae, to galactose and glucose. Subsequently, galactose, which cannot be metabolized by Lb. delbrueckii subsp. bulgaricus, is excreted and provides a carbon source for yeast. (ii) In pure cultures, Lb. delbrueckii subsp. bulgaricus grows only in the presence of increased CO2 concentrations. In anaerobic mixed cultures, the yeast provides this CO2 via alcoholic fermentation. (iii) Analysis of amino acid consumption from the defined medium indicated that S. cerevisiae supplied alanine to the bacterium. (iv) A mild but significant low-iron response in the yeast transcriptome, identified by DNA microarray analysis, was consistent with the chelation of iron by the lactate produced by Lb. delbrueckii subsp. bulgaricus. (v) Transcriptome analysis of Lb. delbrueckii subsp. bulgaricus in mixed cultures showed an overrepresentation of transcripts involved in lipid metabolism, suggesting either a competition of the two microorganisms for fatty acids or a response to the ethanol produced by S. cerevisiae. This study demonstrates that chemostat-based transcriptome analysis is a powerful tool to investigate microbial interactions in mixed populations.
Avendaño-Herrera, Ruben; Balboa, Sabela; Castro, Nuria; González-Contreras, Alberto; Magariños, Beatriz; Fernández, Jorge; Toranzo, Alicia E; Romalde, Jesús L
A polyphasic study was undertaken to clarify the taxonomic position of Streptococcus phocae strains isolated from Atlantic salmon (Salmo salar) cage-farmed in Chile. Four salmon and three seal isolates showed minor differences in the SDS-PAGE protein analysis. Thus, a major protein band present in the salmon isolates, of approximately 22.4 kDa, was absent in the pinniped strains, regardless of the growth media employed. In addition, the pinniped strains showed protein bands with molecular masses of 71.5 and 14.2 kDa, when grown on trypticase soy agar supplemented with 1% NaCl, or 25.6 kDa, when grown on Columbia blood agar, not present in the Atlantic salmon strains. A high similarity in the matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) MS spectra of the strains was observed, although some minor peaks were absent in the fish isolates. Fatty acid methyl esters from isolates with different host origin significantly (P<0.05) differed in the content of C16:0, C17:0, C18:1ω9c, C20:4ω6,9,12,15c and summed features 3, 5 and 8. The salmon isolates formed a separate cluster in the phylogenetic analysis of housekeeping genes, separately or as concatenated sequences. Sequence divergences among salmon and seal strains were in the range of inter-subspecies differentiation for groEL (2.5%), gyrB (1.8%), recN (2.1%), rpoB (1.7%) and sodA (2.0%) genes. DNA-DNA hybridization results confirmed those of sequencing, showing reassociation values between seal and salmon strains close to the borderline of species definition. Differences in growth at low temperatures and in the haemolytic capacities were also observed between both groups of isolates. On the basis of all these results, the salmon isolates represent a novel subspecies of S. phocae, for which the name Streptococcus phocae subsp. salmonis subsp. nov. is proposed. The type strain is C-4T (=CECT 7921T=DSM 24768T). The subspecies Streptococcus phocae subsp. phocae subsp. nov. is automatically created
Laiño, Jonathan Emiliano; Hebert, Elvira María; Savoy de Giori, Graciela
Lactobacillus delbrueckii subsp. bulgaricus CRL871 is the first strain of L. delbrueckii subsp. bulgaricus reported as a folate-producing strain. We report the draft genome sequence of L. delbrueckii subsp. bulgaricus CRL871 (2,063,981 bp, G+C content of 49.1%). This strain is of great biotechnological importance to the dairy industry because it constitutes an alternative to folic acid fortification. PMID:26112792
Gaglio, Raimondo; Barbera, Marcella; Aleo, Aurora; Lommatzsch, Ines; Mantia, Tommaso La; Settanni, Luca
The essential oils (EOs) of green seeds from Daucus carota subsp. maximus growing wild in Pantelleria island (Sicily, Italy) were characterised. EOs were extracted by steam distillation, examined for their inhibitory properties against food-borne Gram positive and Gram negative bacteria and analysed for the chemical composition by gas chromatography (GC) and mass spectrometry (MS). Undiluted EOs showed a large inhibition spectrum against Gram positive strains and also vs Acinetobacter spp. and Stenotrophomonas maltophilia. The minimum inhibition concentration (MIC) was in the range 1.25 - 2.50 μl/ml for the most sensitive strains. The chemical analysis indicated that D. carota subsp. maximus EOs included 34 compounds (5 monoterpene hydrocarbons, 6 oxygenated monoterpenes, 14 sesquiterpene hydrocarbons, 4 oxygenated sesquiterpenes, camphorene and 4 other compounds), accounting for 95.48% of the total oil, and that the major chemicals were carotol, β-bisabolene and isoelemicin. This article is protected by copyright. All rights reserved.
Koya, A; de Wet, S C; Turner, S; Cawdell-Smith, J; Venus, B; Greer, R M; Lew-Tabor, A E; Boe-Hansen, G B
Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intra-peritoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C. fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion.
Ivanitsa, T V; Tovkach, F I
It was established that the polylysogenic phage system of culture Erwinia carotovora subsp. carotovora 91P includes: a) defective bacteriophages of Myoviridae family, which are displayed as macromolecular carotovoricins b) valuable highly unstable temperate phage, which can be attributed to the family Myoviridae, and which, perhaps, is an analogue of phage ZF40 , and c) resistant to osmotic shock temperate phage of family Siphoviridae. This phage, called TIRI, consists of isometric head 50 nm in diameter and a rigid tail structure 203 nm long. A characteristic feature of the phage tail is an evident transverse striation, which is also indicative for the tail-like particle of the defective temperate phage of the strain 48A-7/4b. In general, the phage system of E carotovora subsp. carotovora is similar to Pseudomonas aeruginosa with its R- and F-bacteriocins, and phages of the families Myoviridae and Siphoviridae.
Vila, J; Almela, M; Jimenez de Anta, M T
During a 7-month period, from December 1986 to June 1987, multiresistant strains of Acinetobacter calcoaceticus subsp. anitratus were isolated from 25 patients in a respiratory intensive care unit. The biochemical characteristics defined two groups of strains, group 1 (14 strains) and group 2 (11 strains). Both groups had the same biochemical characteristics, but group 2 strains could assimilate adipate and phenyl acetate. Moreover, of 16 antibiotics tested only netilmicin and imipenem had some inhibitory activity for group 1 strains; group 2 strains were susceptible to mezlocillin, piperacillin, and ticarcillin. Plasmid profiles of the groups were also different. The results of a laboratory investigation (biochemical characteristics, antibiotic susceptibility, and plasmid isolation) identified two different A. calcoaceticus subsp. anitratus strains as the causes of the outbreak. Images PMID:2745682
Furtado, Danielle N; Todorov, Svetoslav D; Landgraf, Mariza; Destro, Maria T; Franco, Bernadette D G M
Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality.
Matos, Ana Cristina; Figueira, Luis; Martins, Maria Helena; Matos, Manuela; Alvares, Sofia; Pinto, Maria Lurdes; Coelho, Ana Cláudia
Disseminated Mycobacterium avium subsp. paratuberculosis (MAP) infections were found in two Eurasian otters (Lutra lutra, L. 1758) killed by vehicular trauma in February and March 2010 in Castelo Branco, Portugal. At postmortem examination, the organs showed no significant gross alterations; however, microscopically, both animals had diffuse lymphadenitis with macrophage infiltration and deposition of hyaline material in the center of the lymphoid follicles. Acid-fast organisms were isolated from gastrointestinal tissue samples via bacteriologic culture. These organisms were identified as M. avium subsp. paratuberculosis by IS900 polymerase chain reaction (PCR). Additionally, direct IS900 PCR-positive results were obtained for multiple organs of both animals. This is the first report of MAP infection of otters in Portugal.
Furtado, Danielle N.; Todorov, Svetoslav D.; Landgraf, Mariza; Destro, Maria T.; Franco, Bernadette D.G.M.
Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp. lactis DF4Mi can be used for enhancement of dairy foods safety and quality. PMID:25763065
Huntley, Jason FJ; Stabel, Judith R; Bannantine, John P
Background The Mycobacterium tuberculosis 19-kDa lipoprotein has been reported to stimulate both T and B cell responses as well as induce a number of Th1 cytokines. In order to evaluate the Mycobacterium avium subsp. paratuberculosis (M. avium subsp. paratuberculosis) 19-kDa lipoprotein as an immunomodulator in cattle with Johne's disease, the gene encoding the 19-kDa protein (MAP0261c) was analyzed. Results MAP0261c is conserved in mycobacteria, showing a 95% amino acid identity in M. avium subspecies avium, 84% in M. intracellulare and 76% in M. bovis and M. tuberculosis. MAP0261c was cloned, expressed, and purified as a fusion protein with the maltose-binding protein (MBP-19 kDa) in Escherichia coli. IFN-γ production was measured from 21 naturally infected and 9 control cattle after peripheral blood mononuclear cells (PBMCs) were stimulated with a whole cell lysate (WCL) of M. avium subsp. paratuberculosis or the recombinant MBP-19 kDa. Overall, the mean response to MBP-19 kDa was not as strong as the mean response to the WCL. By comparison, cells from control, non-infected cattle did not produce IFN-γ after stimulation with either WCL or MBP-19 kDa. To assess the humoral immune response to the 19-kDa protein, sera from cattle with clinical Johne's disease were used in immunoblot analysis. Reactivity to MBP-19 kDa protein, but not MBP alone, was observed in 9 of 14 infected cattle. Antibodies to the 19-kDa protein were not observed in 8 of 9 control cows. Conclusions Collectively, these results demonstrate that while the 19-kDa protein from M. avium subsp. paratuberculosis stimulates a humoral immune response and weak IFN-γ production in infected cattle, the elicited responses are not strong enough to be used in a sensitive diagnostic assay. PMID:15663791
Rademaker, Jan L W; Vissers, Marc M M; Te Giffel, Meike C
The effectiveness of high-temperature, short holding time (HTST) pasteurization and homogenization with respect to inactivation of Mycobacterium avium subsp. paratuberculosis was evaluated quantitatively. This allowed a detailed determination of inactivation kinetics. High concentrations of feces from cows with clinical symptoms of Johne's disease were used to contaminate raw milk in order to realistically mimic possible incidents most closely. Final M. avium subsp. paratuberculosis concentrations varying from 10(2) to 3.5 x 10(5) cells per ml raw milk were used. Heat treatments including industrial HTST were simulated on a pilot scale with 22 different time-temperature combinations, including 60 to 90 degrees C at holding (mean residence) times of 6 to 15 s. Following 72 degrees C and a holding time of 6 s, 70 degrees C for 10 and 15 s, or under more stringent conditions, no viable M. avium subsp. paratuberculosis cells were recovered, resulting in >4.2- to >7.1-fold reductions, depending on the original inoculum concentrations. Inactivation kinetic modeling of 69 quantitative data points yielded an E(a) of 305,635 J/mol and an lnk(0) of 107.2, corresponding to a D value of 1.2 s at 72 degrees C and a Z value of 7.7 degrees C. Homogenization did not significantly affect the inactivation. The conclusion can be drawn that HTST pasteurization conditions equal to 15 s at > or =72 degrees C result in a more-than-sevenfold reduction of M. avium subsp. paratuberculosis.
Noorwala, M; Mohammad, F V; Ahmad, V U
A new triterpenoid saponin, 3-O-[alpha-L-rhamnopyranosyl-(1-->4)-beta-D- galactopyranosyl-(1-->4)-beta-D-glucuronopyranosyl]-soyaspogeno l B  was isolated along with cycloartenol, stigmasterol, 3-O-acetyloleanolic acid, and sitosterol 3-beta-D-glucoside from a methanolic extract of the seeds of Vigna unguiculata subsp. unguiculata. The structure of 1 was elucidated by spectroscopic and chemical means.
Tamayo-Ramos, Juan Antonio; Sanz-Penella, Juan Mario; Yebra, María J.
Two novel phytases have been characterized from Bifidobacterium pseudocatenulatum and Bifidobacterium longum subsp. infantis. The enzymes belong to a new subclass within the histidine acid phytases, are highly specific for the hydrolysis of phytate, and render myo-inositol triphosphate as the final hydrolysis product. They represent the first phytases characterized from this group of probiotic microorganisms, opening the possibilities for their use in the processing of high-phytate-content foods. PMID:22582052
Tamayo-Ramos, Juan Antonio; Sanz-Penella, Juan Mario; Yebra, María J; Monedero, Vicente; Haros, Monika
Two novel phytases have been characterized from Bifidobacterium pseudocatenulatum and Bifidobacterium longum subsp. infantis. The enzymes belong to a new subclass within the histidine acid phytases, are highly specific for the hydrolysis of phytate, and render myo-inositol triphosphate as the final hydrolysis product. They represent the first phytases characterized from this group of probiotic microorganisms, opening the possibilities for their use in the processing of high-phytate-content foods.
Rydlová, Jana; Sýkorová, Zuzana; Slavíková, Renata; Turis, Peter
At present, there is no relevant information on arbuscular mycorrhiza and the effect of the symbiosis on the growth of wild populations of cyclamens. To fill this gap, two populations of Cyclamen purpurascens subsp. immaculatum, endemic in Nízke Tatry (NT) mountains and Veľká Fatra (VF) mountains, Slovakia, were studied in situ as well as in a greenhouse pot experiment. For both populations, mycorrhizal root colonization of native plants was assessed, and mycorrhizal inoculation potential (MIP) of the soils at the two sites was determined in 3 consecutive years. In the greenhouse experiment, the growth response of cyclamens to cross-inoculation with arbuscular mycorrhizal fungi (AMF) was tested: plants from both sites were grown in their native soils and inoculated with a Septoglomus constrictum isolate originating either from the same or from the other plant locality. Although the MIP of soil at the NT site was significantly higher than at the VF site, the level of AMF root colonization of C. purpurascens subsp. immaculatum plants in the field did not significantly differ between the two localities. In the greenhouse experiment, inoculation with AMF generally accelerated cyclamen growth and significantly increased all growth parameters (shoot dry weight, leaf number and area, number of flowers, tuber, and root dry weight) and P uptake. The two populations of C. purpurascens subsp. immaculatum grown in their native soils, however, differed in their response to inoculation. The mycorrhizal growth response of NT plants was one-order higher compared to VF plants, and all their measured growth parameters were stimulated regardless of the fungal isolates' origin. In the VF plants, only the non-native (NT originating) isolate showed a significant positive effect on several growth traits. It can be concluded that mycorrhiza significantly increased fitness of C. purpurascens subsp. immaculatum, despite the differences between plant populations, implying that AMF
Liljander, Anne; Yu, Mingyan; O'Brien, Elizabeth; Heller, Martin; Nepper, Julia F; Weibel, Douglas B; Gluecks, Ilona; Younan, Mario; Frey, Joachim; Falquet, Laurent; Jores, Joerg
Contagious caprine pleuropneumonia (CCPP) is a highly contagious disease caused by Mycoplasma capricolum subsp. capripneumoniae that affects goats in Africa and Asia. Current available methods for the diagnosis of Mycoplasma infection, including cultivation, serological assays, and PCR, are time-consuming and require fully equipped stationary laboratories, which make them incompatible with testing in the resource-poor settings that are most relevant to this disease. We report a rapid, specific, and sensitive assay employing isothermal DNA amplification using recombinase polymerase amplification (RPA) for the detection of M. capricolum subsp. capripneumoniae. We developed the assay using a specific target sequence in M. capricolum subsp. capripneumoniae, as found in the genome sequence of the field strain ILRI181 and the type strain F38 and that was further evidenced in 10 field strains from different geographical regions. Detection limits corresponding to 5 × 10(3) and 5 × 10(4) cells/ml were obtained using genomic DNA and bacterial culture from M. capricolum subsp. capripneumoniae strain ILRI181, while no amplification was obtained from 71 related Mycoplasma isolates or from the Acholeplasma or the Pasteurella isolates, demonstrating a high degree of specificity. The assay produces a fluorescent signal within 15 to 20 min and worked well using pleural fluid obtained directly from CCPP-positive animals without prior DNA extraction. We demonstrate that the diagnosis of CCPP can be achieved, with a short sample preparation time and a simple read-out device that can be powered by a car battery, in <45 min in a simulated field setting.
Stahl, Buffy; Barrangou, Rodolphe
We present the complete genomes of Bifidobacterium animalis subsp. lactis B420 and Bi-07. Comparative genomic analysis with the type strain DSMZ10140 revealed 40 to 55 single nucleotide polymorphisms (SNPs) and an indel in a clustered regularly interspaced short palindromic repeat (CRISPR) locus. These genetic differences provide a molecular basis for strain typing within the two main phylogenetic groups of this monomorphic species.
We present the complete genomes of Bifidobacterium animalis subsp. lactis B420 and Bi-07. Comparative genomic analysis with the type strain DSMZ10140 revealed 40 to 55 single nucleotide polymorphisms (SNPs) and an indel in a clustered regularly interspaced short palindromic repeat (CRISPR) locus. These genetic differences provide a molecular basis for strain typing within the two main phylogenetic groups of this monomorphic species. PMID:22815448
Otto, Peter; Kohlmann, Rebekka; Müller, Wolfgang; Julich, Sandra; Geis, Gabriele; Gatermann, Sören G; Peters, Martin; Wolf, Peter Johannes; Karlsson, Edvin; Forsman, Mats; Myrtennäs, Kerstin; Tomaso, Herbert
In November 2012, a group of 7 persons who participated in a hare hunt in North Rhine-Westphalia, Germany, acquired tularemia. Two F. tularensis subsp. holarctica isolates were cultivated from human and hare biopsy material. Both isolates belonged to the FTN002-00 genetic subclade (derived for single nucleotide polymorphisms B.10 and B.18), thus indicating likely hare-to-human transmission.
Goto, Leandro Seiji; Vessoni Alexandrino, André; Malvessi Pereira, Camila; Silva Martins, Carla; D'Muniz Pereira, Humberto; Brandão-Neto, José; Marques Novo-Mansur, Maria Teresa
Citrus canker, caused by bacteria Xanthomonas citri subsp. citri, can affect all economically important varieties of citrus. Studying Xanthomonas genes related to the invasive capacity may improve the knowledge on how this works and ultimately use the information to avoid the disease. Some annotated genes from Xanthomonas citri subsp. citri published genome are addressed to an interesting class of genes named "pathogenicity, virulence and adaptation". One of them is xanA, which encodes a predicted phosphoglucomutase. Phosphoglucomutases are ubiquitous enzymes among the living kingdoms that play roles in carbohydrate metabolism, catalyzing the reversible conversion of 1- to 6-phosphoglucose. In Xanthomonas, phosphoglucomutase activity is required to synthesize precursors of the pathogenesis-related polysaccharide xanthan. In this work, a characterization of this gene product is presented by structural and functional studies. Molecular cloning was used for heterologous expression and deletion of xanA. A Michaelis-Menten kinetics model was obtained using the recombinant protein. The protein structure was also determined by X-ray diffraction on the recombinant enzyme substrate-free, bound to glucose-1,6-biphosphate and to glucose-1-phosphate. Deletion of xanA was done with a suicide plasmid construct and the obtained mutant was tested for pathogenic capacity. This study is the first describing the properties of the Xanthomonas citri subsp. citri phosphoglucomutase.
Rivas, Amable J; von Hoven, Gisela; Neukirch, Claudia; Meyenburg, Martina; Qin, Qianqian; Füser, Sabine; Boller, Klaus; Lemos, Manuel L; Osorio, Carlos R; Husmann, Matthias
Photobacterium damselae subsp. damselae, an important pathogen of marine animals, may also cause septicemia or hyperaggressive necrotizing fasciitis in humans. We previously showed that hemolysin genes are critical for virulence of this organism in mice and fish. In the present study, we characterized the hlyA gene product, a putative small β-pore-forming toxin, and termed it phobalysin P (PhlyP), for "photobacterial lysin encoded on a plasmid." PhlyP formed stable oligomers and small membrane pores, causing efflux of K(+), with no significant leakage of lactate dehydrogenase but entry of vital dyes. The latter feature distinguished PhlyP from the related Vibrio cholerae cytolysin. Attack by PhlyP provoked a loss of cellular ATP, attenuated translation, and caused profound morphological changes in epithelial cells. In coculture experiments with epithelial cells, Photobacterium damselae subsp. damselae led to rapid hemolysin-dependent membrane permeabilization. Unexpectedly, hemolysins also promoted the association of P. damselae subsp. damselae with epithelial cells. The collective observations of this study suggest that membrane-damaging toxins commonly enhance bacterial adherence.
Reeves, Patrick; Reilley, Ann; Engels, Johannes M. M.; Lohwasser, Ulrike; Börner, Andreas; Pillen, Klaus; Richards, Christopher M.
Informed collecting, conservation, monitoring and utilization of genetic diversity requires knowledge of the distribution and structure of the variation occurring in a species. Hordeum vulgare subsp. spontaneum (K. Koch) Thell., a primary wild relative of barley, is an important source of genetic diversity for barley improvement and co-occurs with the domesticate within the center of origin. We studied the current distribution of genetic diversity and population structure in H. vulgare subsp. spontaneum in Jordan and investigated whether it is correlated with either spatial or climatic variation inferred from publically available climate layers commonly used in conservation and ecogeographical studies. The genetic structure of 32 populations collected in 2012 was analyzed with 37 SSRs. Three distinct genetic clusters were identified. Populations were characterized by admixture and high allelic richness, and genetic diversity was concentrated in the northern part of the study area. Genetic structure, spatial location and climate were not correlated. This may point out a limitation in using large scale climatic data layers to predict genetic diversity, especially as it is applied to regional genetic resources collections in H. vulgare subsp. spontaneum. PMID:27513459
Sassi, Mohamed; Bebeacua, Cecilia; Drancourt, Michel
The unique characteristics of the waxy mycobacterial cell wall raise questions about specific structural features of their bacteriophages. No structure of any mycobacteriophage is available, although ∼3,500 have been described to date. To fill this gap, we embarked in a genomic and structural study of a bacteriophage from Mycobacterium abscessus subsp. bolletii, a member of the Mycobacterium abscessus group. This opportunistic pathogen is responsible for respiratory tract infections in patients with lung disorders, particularly cystic fibrosis. M. abscessus subsp. bolletii was isolated from respiratory tract specimens, and bacteriophages were observed in the cultures. We report here the genome annotation and characterization of the M. abscessus subsp. bolletii prophage Araucaria, as well as the first single-particle electron microscopy reconstruction of the whole virion. Araucaria belongs to Siphoviridae and possesses a 64-kb genome containing 89 open reading frames (ORFs), among which 27 could be annotated with certainty. Although its capsid and connector share close similarity with those of several phages from Gram-negative (Gram−) or Gram+ bacteria, its most distinctive characteristic is the helical tail decorated by radial spikes, possibly host adhesion devices, according to which the phage name was chosen. Its host adsorption device, at the tail tip, assembles features observed in phages binding to protein receptors, such as phage SPP1. All together, these results suggest that Araucaria may infect its mycobacterial host using a mechanism involving adhesion to cell wall saccharides and protein, a feature that remains to be further explored. PMID:23678183
Rivas, Amable J.; von Hoven, Gisela; Neukirch, Claudia; Meyenburg, Martina; Qin, Qianqian; Füser, Sabine; Boller, Klaus; Lemos, Manuel L.; Osorio, Carlos R.
Photobacterium damselae subsp. damselae, an important pathogen of marine animals, may also cause septicemia or hyperaggressive necrotizing fasciitis in humans. We previously showed that hemolysin genes are critical for virulence of this organism in mice and fish. In the present study, we characterized the hlyA gene product, a putative small β-pore-forming toxin, and termed it phobalysin P (PhlyP), for “photobacterial lysin encoded on a plasmid.” PhlyP formed stable oligomers and small membrane pores, causing efflux of K+, with no significant leakage of lactate dehydrogenase but entry of vital dyes. The latter feature distinguished PhlyP from the related Vibrio cholerae cytolysin. Attack by PhlyP provoked a loss of cellular ATP, attenuated translation, and caused profound morphological changes in epithelial cells. In coculture experiments with epithelial cells, Photobacterium damselae subsp. damselae led to rapid hemolysin-dependent membrane permeabilization. Unexpectedly, hemolysins also promoted the association of P. damselae subsp. damselae with epithelial cells. The collective observations of this study suggest that membrane-damaging toxins commonly enhance bacterial adherence. PMID:26303391
Sun, Dongling; Zhuo, Tao; Fan, Xiaojing; Zou, Huasong
Xanthomonas citri subsp. citri causes citrus canker disease, which is characterized by the formation of water-soaked lesions, white or yellow spongy pustules and brown corky canker. In this work, we report the contribution of extracellular endoglucanase to canker development during infection. The ectopic expression of nine putative cellulases in Escherichia coli indicated that two endoglucanases, BglC3 and EngXCA, show carboxymethyl cellulase activity. Both bglC3 and engXCA genes were transcribed in X. citri subsp. citri, however, only BglC3 protein was detected outside the cell in western blot analysis. The deletion of bglC3 gene resulted in complete loss of extracellular carboxymethyl cellulase activity and delayed the onset of canker symptoms in both infiltration- and wound-inoculation assays. When growing in plant tissue, the cell density of bglC3 mutant was lower than that of the wild type. Our data demonstrated that BglC3 is an extracellular endoglucanase required for the full virulence of X. citri subsp. citri. PMID:26950296
Whittington, Richard J.; Marshall, D. Jeff; Nicholls, Paul J.; Marsh, Ian B.; Reddacliff, Leslie A.
The survival of Mycobacterium avium subsp. paratuberculosis was studied by culture of fecal material sampled at intervals for up to 117 weeks from soil and grass in pasture plots and boxes. Survival for up to 55 weeks was observed in a dry fully shaded environment, with much shorter survival times in unshaded locations. Moisture and application of lime to soil did not affect survival. UV radiation was an unlikely factor, but infrared wavelengths leading to diurnal temperature flux may be the significant detrimental component that is correlated with lack of shade. The organism survived for up to 24 weeks on grass that germinated through infected fecal material applied to the soil surface in completely shaded boxes and for up to 9 weeks on grass in 70% shade. The observed patterns of recovery in three of four experiments and changes in viable counts were indicative of dormancy, a hitherto unreported property of this taxon. A dps-like genetic element and relA, which are involved in dormancy responses in other mycobacteria, are present in the M. avium subsp. paratuberculosis genome sequence, providing indirect evidence for the existence of physiological mechanisms enabling dormancy. However, survival of M. avium subsp. paratuberculosis in the environment is finite, consistent with its taxonomic description as an obligate parasite of animals. PMID:15128561
Li, Xiaofan; Chen, Jianhui
Bacterial infection is a common complication after Hematopoietic Stem Cell Transplantation (HSCT). Morganella morganii is ubiquitous Gram-negative facultative anaerobe, which may cause many kinds of opportunistic infection. Herein we report a case of a 55-year-old man who presented with frequent urination, urgency, and mild pain that comes and goes low in the abdomen and around the anus. The patient had a medical history of chronic prostatitis for 4 years. He received HLA-matched sibling allo-HSCT because of angioimmunoblastic T-cell lymphoma 29 months ago. The routine examination of prostatic fluid showed increased leukocytes and the culture of prostatic fluid showed Morganella morganii subsp. morganii. The patient developed chills and fever 18 hours after examination. Both urine culture and blood culture showed Morganella morganii subsp. morganii. The patient was successfully treated with antibiotic therapy and septic shock management. Taken together, Morganella morganii should be considered a possible pathogen when immunocompromised patients develop prostatitis. Also, prostatic massage could be a possible trigger of septic shock induced by Morganella morganii subsp. morganii in a posttransplantation patient. PMID:26798544
Smadja, Bruno; Latour, Xavier; Faure, Denis; Chevalier, Sylvie; Dessaux, Yves; Orange, Nicole
Erwinia carotovora subsp. atroseptica is responsible for potato blackleg disease in the field and tuber soft rot during crop storage. The process leading to the disease occurs in two phases: a primary invasion step followed by a maceration step. Bacteria-to-bacteria communication is associated with a quorum-sensing (QS) process based on the production of N-acylhomoserine lactones (HSL). The role of HSL throughout plant infection was analyzed. To this purpose, HSL produced by a specific E. carotovora subsp. atroseptica wild-type strain, which was particularly virulent on potato, were identified. A derivative of this strain that expressed an HSL lactonase gene and produced low amounts of HSL was generated. The comparison of these strains allowed the evaluation of the role of HSL and QS in disease establishment and development. Bacterial growth and motility; activity of proteins secreted by type I, II, and III systems; and hypersensitive and maceration reactions were evaluated. Results indicated that HSL production and QS regulate only those traits involved in the second stage of the host plant infection (i.e., tissue maceration) and hypersensitive response in nonhost tobacco plants. Therefore, the use of QS quenching strategies for biological control in E. carotovora subsp. atroseptica cannot prevent initial infection and multiplication of this pathogen.
Otten, S L; Stutzman-Engwall, K J; Hutchinson, C R
Genes for the biosynthesis of daunorubicin (daunomycin) and doxorubicin (adriamycin), important antitumor drugs, were cloned from Streptomyces peucetius (the daunorubicin producer) and S. peucetius subsp. caesius (the doxorubicin producer) by use of the actI/tcmIa and actIII polyketide synthase gene probes. Restriction mapping and Southern analysis of the DNA cloned in a cosmid vector established that the DNA represented three nonoverlapping regions of the S. peucetius subsp. caesius genome. These three regions plus an additional one that hybridized to the same probes are present in the S. peucetius genome, as reported previously (K. J. Stutzman-Engwall and C. R. Hutchinson, Proc. Natl. Acad. Sci. USA 86:3135-3139, 1989). Functional analysis of representative clones from some of these regions in S. lividans, S. peucetius ATCC 29050, S. peucetius subsp. caesius ATCC 27952, and two of its blocked mutants (strains H6101 and H6125) showed that many of the antibiotic production genes reside in the region of DNA represented by the group IV clones. This conclusion is based on the production of epsilon-rhodomycinone, a key intermediate of the daunorubicin pathway, in certain S. lividans transformants and on the apparent complementation of mutations that block daunorubicin biosynthesis in strains H6101 and H6125. Some of the transformants of strains 29050, 27952, and H6125 exhibited substantial overproduction of epsilon-rhodomycinone and daunorubicin. PMID:2345153
Hiery, Eva; Adam, Susanne; Reid, Stephen; Hofmann, Jörg; Sonnewald, Sophia; Burkovski, Andreas
The interaction between Clavibacter michiganensis subsp. michiganensis with its host, the tomato plant (Solanum lycopersicum), is poorly understood and only few virulence factors are known. While studying of the bacteria in planta is time-consuming and difficult, the analysis in vitro would facilitate research. Therefore, a xylem mimicking medium (XMM) for C. michiganensis subsp. michiganensis was established in this study based on an apoplast medium for Xanthomonas campestris pv. vesicatoria. In contrast to the apoplast medium, XMM contains no sugars, but amino acids which serve as nitrogen and carbon source. As a result, growth in XMM induced transcriptional changes of genes encoding putative sugar, amino acid and iron uptake systems. In summary, mRNA levels of about 8% of all C. michiganensis subsp. michiganensis genes were changed when XMM-grown bacteria were compared to M9 minimal medium-grown cells. Almost no transcriptional changes of genes encoding hydrolytic enzymes were detected, leading to the idea that XMM reflects the situation in the beginning of infection and therefore allows the characterization of virulence factors in this early stage of infection. The addition of the plant wound substance acetosyringone to the XMM medium led to a change in transcript amount, including genes coding for proteins involved in protein transport, iron uptake and regulation processes.
Geetha, I; Manonmani, A M; Paily, K P
The culture supernatant of a strain of Bacillus subtilis subsp. subtilis isolated from mangrove forests of Andaman and Nicobar islands, India was found to kill larval and pupal stages of mosquitoes. A chloroform extract of the culture supernatant of the bacterium showed pupicidal effects at an LC(50) dose of 1 microg/ml. The mosquitocidal metabolite(s) produced by this strain were purified by gel permeation chromatography. The purified fraction was subjected to Fourier transform infrared (FTIR) spectroscopy and Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. The FTIR spectrum of active fraction/CHCl3 residue showed strong band characteristic of peptides. MALDI-TOF spectrum of the sample showed well-resolved group of peaks at m/z values 1,030.6, 1,046.7, 1,044.6, 1,060.5, 1,058.6, 1,058.7, and 1,074.6. The results indicated production of different isoforms of surfactin, ranging from C13-C15. Further, the sfp gene responsible for the production of surfactin was amplified and sequenced. In conclusion, this study showed that the mosquito pupicidal metabolite(s), produced by B. subtilis subsp. subtilis is the cyclic lipopeptide, surfactin. The mode of action of surfactin on pupae of mosquitoes is discussed. This is the first report on the mosquito pupicidal activity of surfactin produced by B. subtilis subsp. subtilis.
Seo, Samyeol; Lee, Sunghong; Hong, Yongpyo
The entomopathogenic bacteria Xenorhabdus nematophila and Photorhabdus temperata subsp. temperata suppress insect immune responses by inhibiting the catalytic activity of phospholipase A2 (PLA2), which results in preventing biosynthesis of immune-mediating eicosanoids. This study identified PLA2 inhibitors derived from culture broths of these two bacteria. Both X. nematophila and P. temperata subsp. temperata culture broths possessed significant PLA2-inhibitory activities. Fractionation of these bacterial metabolites in the culture broths using organic solvent and subsequent chromatography purified seven potent PLA2 inhibitors, three of which (benzylideneacetone [BZA], proline-tyrosine [PY], and acetylated phenylalanine-glycine-valine [FGV]) were reported in a previous study. Four other compounds (indole, oxindole, cis-cyclo-PY, and p-hydroxyphenyl propionic acid) were identified and shown to significantly inhibit PLA2. X. nematophila culture broth contained these seven compounds, while P. temperata subsp. temperata culture broth contained three compounds (BZA, acetylated FGV, and cis-cyclo-PY). BZA was detected in the largest amount among these PLA2 compounds in both bacterial culture broths. All seven bacterial metabolites also showed significant inhibitory activities against immune responses, such as phenoloxidase activity and hemocytic nodulation; BZA was the most potent. Finally, this study characterized these seven compounds for their insecticidal activities against the diamondback moth, Plutella xylostella. Even though these compounds showed relatively low toxicities to larvae, they significantly enhanced the pathogenicity of Bacillus thuringiensis. This study reports bacterial-origin PLA2 inhibitors, which would be applicable for developing novel insecticides. PMID:22447611
Thormann, Imke; Reeves, Patrick; Reilley, Ann; Engels, Johannes M M; Lohwasser, Ulrike; Börner, Andreas; Pillen, Klaus; Richards, Christopher M
Informed collecting, conservation, monitoring and utilization of genetic diversity requires knowledge of the distribution and structure of the variation occurring in a species. Hordeum vulgare subsp. spontaneum (K. Koch) Thell., a primary wild relative of barley, is an important source of genetic diversity for barley improvement and co-occurs with the domesticate within the center of origin. We studied the current distribution of genetic diversity and population structure in H. vulgare subsp. spontaneum in Jordan and investigated whether it is correlated with either spatial or climatic variation inferred from publically available climate layers commonly used in conservation and ecogeographical studies. The genetic structure of 32 populations collected in 2012 was analyzed with 37 SSRs. Three distinct genetic clusters were identified. Populations were characterized by admixture and high allelic richness, and genetic diversity was concentrated in the northern part of the study area. Genetic structure, spatial location and climate were not correlated. This may point out a limitation in using large scale climatic data layers to predict genetic diversity, especially as it is applied to regional genetic resources collections in H. vulgare subsp. spontaneum.
Yu, Yi; Fan, Qiang; Shen, Rujiang; Guo, Wei; Jin, Jianhua; Cui, Dafang; Liao, Wenbo
Disanthus cercidifolius subsp. longipes is an endangered species in China. Genetic diversity and structure analysis of this species was investigated using amplified fragments length polymorphism (AFLP) fingerprinting. Nei's gene diversity ranged from 0.1290 to 0.1394. The AMOVA indicated that 75.06% of variation was distributed within populations, while the between-group component 5.04% was smaller than the between populations-within-group component 19.90%. Significant genetic differentiation was detected between populations. Genetic and geographical distances were not correlated. PCA and genetic structure analysis showed that populations from East China were together with those of the Nanling Range. These patterns of genetic diversity and levels of genetic variation may be the result of D. c. subsp. longipes restricted to several isolated habitats and “excess flowers production, but little fruit set”. It is necessary to protect all existing populations of D. c. subsp. longipes in order to preserve as much genetic variation as possible. PMID:25250583
Mattinen, Laura; Tshuikina, Marina; Mäe, Andres; Pirhonen, Minna
Erwinia carotovora subsp. carotovora is a gram-negative bacterium that causes soft rot disease of many cultivated crops. When a collection of E. carotovora subsp. carotovora isolates was analyzed on a Southern blot using the harpin-encoding gene hrpN as probe, several harpinless isolates were found. Regulation of virulence determinants in one of these, strain SCC3193, has been characterized extensively. It is fully virulent on potato and in Arabidopsis thaliana. An RpoS (SigmaS) mutant of SCC3193, producing elevated levels of secreted proteins, was found to cause lesions resembling the hypersensitive response when infiltrated into tobacco leaf tissue. This phenotype was evident only when bacterial cells had been cultivated on solid minimal medium at low pH and temperature. The protein causing'the cell death was purified and sequenced, and the corresponding gene was cloned. The deduced sequence of the necrosis-inducing protein (Nip) showed homology to necrosis- and ethylene-inducing elicitors of fungi and oomycetes. A mutant strain of E. carotovora subsp. carotovora lacking the nip gene showed reduced virulence in potato tuber assay but was unaffected in virulence in potato stem or on other tested host plants.
Pescuma, Micaela; Hébert, Elvira M; Haertlé, Thomas; Chobert, Jean-Marc; Mozzi, Fernanda; Font de Valdez, Graciela
Whey, a cheese by-product used as a food additive, is produced worldwide at 40.7 million tons per year. β-Lactoglobulin (BLG), the main whey protein, is poorly digested and is highly allergenic. We aimed to study the contribution of Lactobacillus delbrueckii subsp. bulgaricus CRL 454 to BLG digestion and to analyse its ability to degrade the main allergenic sequences of this protein. Pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 increases digestion of BLG assayed by an in vitro simulated gastrointestinal system. Moreover, peptides from hydrolysis of the allergenic sequences V41-K60, Y102-R124, C121-L140 and L149-I162 were found when BLG was hydrolysed by this strain. Interestingly, peptides possessing antioxidant, ACE inhibitory, antimicrobial and immuno-modulating properties were found in BLG degraded by both the Lactobacillus strain and digestive enzymes. To conclude, pre-hydrolysis of BLG by L. delbrueckii subsp. bulgaricus CRL 454 has a positive effect on BLG digestion and could diminish allergenic reactions.
Juniperus oxycedrus L. subsp. oxycedrus and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. "berries" from Turkey: comparative evaluation of phenolic profile, antioxidant, cytotoxic and antimicrobial activities.
Taviano, Maria Fernanda; Marino, Andreana; Trovato, Ada; Bellinghieri, Valentina; Melchini, Antonietta; Dugo, Paola; Cacciola, Francesco; Donato, Paola; Mondello, Luigi; Güvenç, Ayşegül; De Pasquale, Rita; Miceli, Natalizia
This work aimed to evaluate and compare the phenolic profile and some biological properties of the ripe "berries" methanol extracts of Juniperus oxycedrus L. subsp. oxycedrus (Joo) and Juniperus oxycedrus L. subsp. macrocarpa (Sibth. & Sm.) Ball. (Jom) from Turkey. The total phenolic content resulted about 3-fold higher in Jom (17.89±0.23 mg GAE/g extract) than in Joo (5.14±0.06 mg GAE/g extract). The HPLC-DAD-ESI-MS analysis revealed a similar flavonoid fingerprint in Joo and Jom, whereas a difference in their quantitative content was found (4632 μg/g extract and 12644 μg/g extract). In addition, three phenolic acids were detected in Jom only (5765 μg/g extract), and protocatechuic acid was the most abundant one. The antioxidant capacity of the extracts was evaluated by different in vitro assays: in the DPPH and in the TBA tests a stronger activity in Jom was highlighted, while Joo exhibited higher reducing power and metal chelating activity. Joo and Jom did not affect HepG2 cell viability and both extracts resulted virtually non-toxic against Artemia salina. The extracts were also studied for their antimicrobial potential, displaying efficacy against Gram-positive bacteria.
El Zerey-Belaskri, Asma; Benhassaini, Hachemi
The effect of bioclimate range on the variation in Pistacia atlantica Desf. subsp. atlantica leaf morphology was studied on 16 sites in Northwest Algeria. The study examined biometrically mature leaves totaling 3520 compound leaves. Fifteen characters (10 quantitative and 5 qualitative) were assessed on each leaf. For each quantitative character, the nested analysis of variance (ANOVA) was used to examine relative magnitude of variation at each level of the nested hierarchy. The correlation between the climatic parameters and the leaf morphology was examined. The statistical analysis applied on the quantitative leaf characters showed highly significant variation at the within-site level and between-site variation. The correlation coefficient (r) showed also an important correlation between climatic parameters and leaf morphology. The results of this study exhibited several values reported for the first time on the species, such as the length and the width of the leaf (reaching up to 24.5 cm/21.9 cm), the number of leaflets (up to 18 leaflets/leaf), and the petiole length of the terminal leaflet (reaching up to 3.4 cm). The original findings of this study are used to update the P. atlantica subsp. atlantica identification key.
Prado, Susana; Dubert, Javier; Barja, Juan L
The taxonomic position of the bivalve pathogen PP-638 was studied together with five similar isolates. The strains were isolated from flat oyster (Ostrea edulis) and Manila clam (Venerupis philippinarum) cultures during outbreaks of disease in two shellfish hatcheries (Galicia, NW Spain). The pathogenicity, previously established for PP-638, was demonstrated with all isolates and for several bivalve species, including the original hosts. On the basis of phenotypic characterization and 16S rRNA gene sequences, a tight group was defined within the genus Vibrio. Multilocus sequence analysis (MLSA) based on concatenated sequences of the 16S rRNA gene and the five housekeeping genes recA, rpoA, pyrH, gyrB and ftsZ revealed that these strains form a cluster within the Orientalis clade, close to the species Vibrio tubiashii. The results of MLSA, the DDH rate and the phenotypic differences with the type strain of V. tubiashii supported the differentiation of the Galician isolates as a new subspecies within V. tubiashii, for which the name V. tubiashii subsp. europaeus [corrected] subsp. nov. is proposed (type strain PP-638(T)=CECT 8136(T)=DSM 7349(T)) The emended description of V. tubiashii is included. The pathogenicity assays widen the host range of V. tubiashii to add two unreported species, Venerupis decussata and Donax trunculus, and the described as relatively resistant species V. philippinarum.
Clair, Emilie; Linn, Laura; Travert, Carine; Amiel, Caroline; Séralini, Gilles-Eric; Panoff, Jean-Michel
Use of many pesticide products poses the problem of their effects on environment and health. Amongst them, the effects of glyphosate with its adjuvants and its by-products are regularly discussed. The aim of the present study was to shed light on the real impact on biodiversity and ecosystems of Roundup(®), a major herbicide used worldwide, and the glyphosate it contains, by the study of their effects on growth and viability of microbial models, namely, on three food microorganisms (Geotrichum candidum, Lactococcus lactis subsp. cremoris and Lactobacillus delbrueckii subsp. bulgaricus) widely used as starters in traditional and industrial dairy technologies. The presented results evidence that Roundup(®) has an inhibitory effect on microbial growth and a microbicide effect at lower concentrations than those recommended in agriculture. Interestingly, glyphosate at these levels has no significant effect on the three studied microorganisms. Our work is consistent with previous studies which demonstrated that the toxic effect of glyphosate was amplified by its formulation adjuvants on different human cells and other eukaryotic models. Moreover, these results should be considered in the understanding of the loss of microbiodiversity and microbial concentration observed in raw milk for many years.
Khumalo, Zamantungwa T. H.; Catanese, Helen N.; Liesching, Nicole; Hove, Paidashe; Collins, Nicola E.; Chaisi, Mamohale E.; Gebremedhin, Assefaw H.; Oosthuizen, Marinda C.
Bovine anaplasmosis caused by the intraerythrocytic rickettsial pathogen Anaplasma marginale is endemic in South Africa. Anaplasma marginale subspecies centrale also infects cattle; however, it causes a milder form of anaplasmosis and is used as a live vaccine against A. marginale. There has been less interest in the epidemiology of A. marginale subsp. centrale, and, as a result, there are few reports detecting natural infections of this organism. When detected in cattle, it is often assumed that it is due to vaccination, and in most cases, it is reported as coinfection with A. marginale without characterization of the strain. A total of 380 blood samples from wild ruminant species and cattle collected from biobanks, national parks, and other regions of South Africa were used in duplex real-time PCR assays to simultaneously detect A. marginale and A. marginale subsp. centrale. PCR results indicated high occurrence of A. marginale subsp. centrale infections, ranging from 25 to 100% in national parks. Samples positive for A. marginale subsp. centrale were further characterized using the msp1aS gene, a homolog of msp1α of A. marginale, which contains repeats at the 5′ ends that are useful for genotyping strains. A total of 47 Msp1aS repeats were identified, which corresponded to 32 A. marginale subsp. centrale genotypes detected in cattle, buffalo, and wildebeest. RepeatAnalyzer was used to examine strain diversity. Our results demonstrate a diversity of A. marginale subsp. centrale strains from cattle and wildlife hosts from South Africa and indicate the utility of msp1aS as a genotypic marker for A. marginale subsp. centrale strain diversity. PMID:27440819
Mycobacterium avium subsp. paratuberculosis antibody response, fecal shedding, and antibody cross-reactivity to Mycobacterium bovis in M. avium subsp. paratuberculosis-infected cattle herds vaccinated against Johne's disease.
Tewari, Deepanker; Hovingh, Ernest; Linscott, Rick; Martel, Edmond; Lawrence, John; Wolfgang, David; Griswold, David
Vaccination for Johne's disease with killed inactivated vaccine in cattle herds has shown variable success. The vaccine delays the onset of disease but does not afford complete protection. Johne's disease vaccination has also been reported to interfere with measurements of cell-mediated immune responses for the detection of bovine tuberculosis. Temporal antibody responses and fecal shedding of Mycobacterium avium subsp. paratuberculosis, the causative agent of Johne's disease, were measured in 2 dairy cattle herds using Johne's disease vaccine (Mycopar) over a period of 7 years. Vaccination against Johne's disease resulted in positive serum M. avium subsp. paratuberculosis antibody responses in both herds, and the responses persisted in vaccinated cattle up to 7 years of age. Some vaccinated animals (29.4% in herd A and 36.2% in herd B) showed no serological reactivity to M. avium subsp. paratuberculosis. M. avium subsp. paratuberculosis-specific antibody responses were also detected in milk from Johne's disease-vaccinated animals, but fewer animals (39.3% in herd A and 49.4% in herd B) had positive results with milk than with serum samples. With vaccination against M. avium subsp. paratuberculosis, fecal shedding in both dairy herds was reduced significantly (P < 0.001). In addition, when selected Johne's disease-vaccinated and -infected animals were investigated for serological cross-reactivity to Mycobacterium bovis, no cross-reactivity was observed.
Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections
Whitney, A. M.; Humrighouse, B. W.
Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324T, 97.9% similarity to S. canis ATCC 43496T, and 97.8% similarity to S. ictaluri ATCC BAA-1300T. A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844T = CCUG 67100T = LMG 28801T. PMID:26763962
Phenotypic, Genotypic, and Antimicrobial Characteristics of Streptococcus halichoeri Isolates from Humans, Proposal To Rename Streptococcus halichoeri as Streptococcus halichoeri subsp. halichoeri, and Description of Streptococcus halichoeri subsp. hominis subsp. nov., a Bacterium Associated with Human Clinical Infections.
Shewmaker, P L; Whitney, A M; Humrighouse, B W
Phenotypic, genotypic, and antimicrobial characteristics of six phenotypically distinct human clinical isolates that most closely resembled the type strain of Streptococcus halichoeri isolated from a seal are presented. Sequencing of the 16S rRNA, rpoB, sodA, and recN genes; comparative whole-genome analysis; conventional biochemical and Rapid ID 32 Strep identification methods; and antimicrobial susceptibility testing were performed on the human isolates, the type strain of S. halichoeri, and type strains of closely related species. The six human clinical isolates were biochemically indistinguishable from each other and showed 100% 16S rRNA, rpoB, sodA, and recN gene sequence similarity. Comparative 16S rRNA gene sequencing analysis revealed 98.6% similarity to S. halichoeri CCUG 48324(T), 97.9% similarity to S. canis ATCC 43496(T), and 97.8% similarity to S. ictaluri ATCC BAA-1300(T). A 3,530-bp fragment of the rpoB gene was 98.8% similar to the S. halichoeri type strain, 84.6% to the S. canis type strain, and 83.8% to the S. ictaluri type strain. The S. halichoeri type strain and the human clinical isolates were susceptible to the antimicrobials tested based on CLSI guidelines for Streptococcus species viridans group with the exception of tetracycline and erythromycin. The human isolates were phenotypically distinct from the type strain isolated from a seal; comparative whole-genome sequence analysis confirmed that the human isolates were S. halichoeri. On the basis of these results, a novel subspecies, Streptococcus halichoeri subsp. hominis, is proposed for the human isolates and Streptococcus halichoeri subsp. halichoeri is proposed for the gray seal isolates. The type strain of the novel subspecies is SS1844(T) = CCUG 67100(T) = LMG 28801(T).
Obilie, Eric Mantey; Tano-Debrah, Kwaku; Amoa-Awua, Wisdom Kofi
The population and composition of the lactic acid bacteria microbiota as well as the content of cyanogenic glucosides occurring at various stages of fermentation and subsequent processing of cassava roots into akyeke, a steamed sour cassava meal, were investigated. The number of lactic acid bacteria and percentage titratable acidity increased during 5 days of fermentation, but decreases were observed in the subsequent operations of 'washing' the dough with water followed by partial drying and steaming. In field and laboratory samples, Lactobacillus plantarum accounted for 59.3% and 52.3%, Lactobacillus brevis 23.3% and 22.8% and Leuconostoc mesenteroides subsp. cremoris 14.5% and 15.8%, respectively, of all lactic acid bacteria isolated at various stages of fermentation and processing. A reduction of about 98% occurred in the total cyanogens (CN) content of cassava roots during processing, from 69.3 to 1.4 and 110.3 to 2.8 mg CN equivalent/kg dry weight for laboratory and field samples of akyeke, respectively.
González, Leticia; Sacristán, Noelia; Arenas, Ricardo; Fresno, José M; Eugenia Tornadijo, M
Twenty-four strains of lactic acid bacteria (LAB) isolated from a traditional Spanish cheese (Genestoso cheese) were evaluated for their enzymatic activities (acidifying and proteolytic abilities and carboxypeptidase, aminopeptidase, dipeptidase, caseinolytic and esterase activities), in order to select indigenous strains of technical interest for the manufacture of cheese. These strains were selected on the basis of their antimicrobial activity relative to five reference strains and were identified as Lactococcus lactis subsp. lactis (thirteen strains), Leuconostoc mesenteroides (two strains), Leuconostoc pseudomesenteroides (one strain), Lactobacillus paracasei (two strains), Lactobacillus plantarum (one strain) and Enterococcus faecalis (five strains). Lactococcus strains were those that showed the greatest degree of acidifying and proteolytic activity. The cell-free extracts (CFE) of L. paracasei exhibited the highest level of aminopeptidase activity. The highest level of caseinolytic activity was shown by the CFE of one strain of L. lactis. High values were also obtained with the CFE of Lactobacillus and of several Leuconostoc. The highest level of dipeptidase activity was found amongst the strains of L. lactis. Carboxypeptidase activity was generally very low or undetectable for the majority of strains. The greatest degree of esterolytic activity was detected for Enterococcus.
Colombo, E; Franzetti, L; Frusca, M; Scarpellini, M
The lactic acid bacteria community in traditional goat cheese produced in three dairies in Valsesia (Piemonte, Italy) was studied at different steps of the manufacturing process. These cheeses were produced from raw milk without starter bacteria, and no protocol was followed during the manufacturing process. Three hundred thirty-two isolates were characterized and grouped by results of both morphophysiological tests and random amplification of polymorphic DNA plus PCR analysis. Bacteria were identified by partial sequencing of the 16S rRNA gene. Lactococci were the dominant lactic acid bacteria in raw milk. Their initial numbers ranged from 5 to 7 log CFU ml(-1). Their levels increased during manufacturing and decreased during ripening. The growth trend for enterococci was comparable to that of lactococci, although enterococci counts were lower. Lactococcus lactis subsp. cremoris, Lactococcus garviae, and Enterococcus faecalis were the most frequently isolated species during goat cheese manufacturing, whereas the highest numbers of Enterococcus (E. faecium, E. durans, E. gilvus, and E. casseliflavus) were isolated with the greatest frequency from ripened cheese samples. Occasionally, Leuconostoc mesenteroides, Leuconostoc lactis, and Lactobacillus paraplantarum also were isolated.
In this study, traditional culture method and 16S rRNA gene analysis were applied to reveal the composition and diversity of lactic acid bacteria (LAB) of fermented cow milk, huruud and urum from Baotou and Bayannur of midwestern Inner Mongolia. Also, the quantitative results of dominant LAB species in three different types of dairy products from Baotou and Bayannur were gained by quantitative polymerase chain reaction (q-PCR) technology. Two hundred and two LAB strains isolated from sixty-six samples were identified and classified into four genera, namely Enterococcus, Lactococcus, Lactobacillus, Leuconostoc, and twenty-one species and subspecies. From these isolates, Lactococcus lactis subsp. lactis (32.18%), Lactobacillus plantarum (12.38%) and Leuconosto mesenteroides (11.39%) were considered as the dominated LAB species under the condition of cultivating in MRS and M17 medium. And the q-PCR results revealed that the number of dominant species varied from samples to samples and from region to region. This study clearly shows the composition and diversity of LAB existing in fermented cow milk, huruud and urum, which could be considered as valuable resources for LAB isolation and further probiotic selection. PMID:27621691
Tjandraatmadja, M; Norton, B W; Mac Rae, I C
The effects of adding two legumes, Gliricidia sepium and Leucaena leucocephala, cv. Cunningham, and molasses on the fermentation characteristics of silages made from two tropical grasses (Pangola grass, Digitaria decumbens, and Setaria sphacelata cv. Kazungula) were investigated. Pangola grass silages contained significantly higher contents of water-soluble carbohydrates and lactic acid than did setaria silages after 100 days fermentation, but there were no significant differences between the two silages in populations of lactic acid bacteria and contents of total N and NH3-N. Addition of either species of legume had no significant effect on fermentation acids and NH3-N contents, and numbers of lactic acid bacteria. Addition of both legumes reduced NH3-N production in the silages by 59% after 5 days' fermentation. Numbers of lactic acid bacteria were not significantly affected by the different treatments. Enterococcus faecalis represented 60% of the lactic acid bacteria isolated from the treated herbages prior to ensiling. By 100 days of fermentation, only lactobacilli were isolated: 82% homo-fermenters and 18% hetero-fermenters. Lactobacillus mesenteroides subsp. dextranicum was found only in the silage supplemented with 33% (w/w) legume. It was concluded that the low quality of tropical grasses used as feeds for ruminants may be significantly improved by ensiling these grasses with small amounts of molasses and with high-protein tree leaves.
Šurinová, Mária; Brabec, Jiří; Münzbergová, Zuzana
Premise of the study: Polymorphic microsatellite loci were developed and used to genotype individuals of Gentianella praecox subsp. bohemica (Gentianaceae), a highly protected taxon in Europe, to study the genetic structure of the remaining populations. Methods and Results: Thirty-eight primer pairs were successfully amplified; of these, 12 polymorphic microsatellite loci were developed using a 454 sequencing approach and used to genotype 180 individuals of G. praecox subsp. bohemica from six populations. Allelic richness ranged between one and nine alleles per locus. We detected a high frequency of polyploid individuals (77.8%). The highest average percentage of heterozygous genotypes was identified for samples from the Hroby population (75.5%). All loci can also be amplified in the congeneric species G. praecox subsp. praecox, G. amarella subsp. amarella, and G. obtusifolia subsp. sturmiana. Conclusions: These markers will provide knowledge on patterns of gene flow and population genetic structure, which is necessary for current protection actions and for effective conservation of this species in the future. PMID:28090411
Ishino, Y; Morgenthaler, P; Hottinger, H; Söll, D
A 3.3-kb BamHI fragment of Lactobacillus delbrueckii subsp. bulgaricus DNA was cloned and sequenced. It complements an Escherichia coli glnA deletion strain and hybridizes strongly to a DNA containing the Bacillus subtilis glnA gene. DNA sequence analysis of the L. delbrueckii subsp. bulgaricus DNA showed it to contain the glnA gene encoding class I glutamine synthetase, as judged by extensive homology with other prokaryotic glnA genes. The sequence suggests that the enzyme encoded in this gene is not controlled by adenylylation. Based on a comparison of glutamine synthetase sequences, L. delbrueckii subsp. bulgaricus is much closer to gram-positive eubacteria, especially Clostridium acetobutylicum, than to gram-negative eubacteria and archaebacteria. The fragment contains another open reading frame encoding a protein of unknown function consisting of 306 amino acids (ORF306), which is also present upstream of glnA of Bacillus cereus. In B. cereus, a repressor gene, glnR, is found between the open reading frame and glnA. Two proteins encoded by the L. delbrueckii subsp. bulgaricus gene were identified by the maxicell method; the sizes of these proteins are consistent with those of the open reading frames of ORF306 and glnA. The lack of a glnR gene in the L. delbrueckii subsp. bulgaricus DNA in this position may indicate a gene rearrangement or a different mechanism of glnA gene expression. Images PMID:1359838
Draft genome sequence of Staphylococcus saprophyticus subsp. saprophyticus M1-1, isolated from the gills of a Korean rockfish, Sebastes schlegeli Hilgendorf, after high hydrostatic pressure processing.
Kim, Bong-Soo; Kim, Chong-Tai; Park, Bang Heon; Kwon, Sujin; Cho, Yong-Jin; Kim, Namsoo; Kim, Chul-Jin; Chun, Jongsik; Kwak, Jangyul; Maeng, Jin-Soo
A bacterium designated M1-1 was isolated from the gills of a Korean rockfish, Sebastes schlegeli Hilgendorf, after high hydrostatic pressure processing. Studies of 16S rRNA phylogeny and comparative genomics demonstrated that the isolate belongs to Staphylococcus saprophyticus subsp. saprophyticus. Here, we report the draft genome sequence of S. saprophyticus subsp. saprophyticus M1-1 (KACC 16562).
Guidi, Valeria; Patocchi, Nicola; Lüthy, Peter; Tonolla, Mauro
Recurrent treatments with Bacillus thuringiensis subsp. israelensis are required to control the floodwater mosquito Aedes vexans that breeds in large numbers in the wetlands of the Bolle di Magadino Reserve in Canton Ticino, Switzerland. Interventions have been carried out since 1988. In the present study, the spatial distribution of resting B. thuringiensis subsp. israelensis spores in the soil was measured. The B. thuringiensis subsp. israelensis concentration was determined in soil samples collected along six transects covering different elevations within the periodically flooded zones. A total of 258 samples were processed and analyzed by quantitative PCR that targeted an identical fragment of 159 bp for the B. thuringiensis subsp. israelensis cry4Aa and cry4Ba genes. B. thuringiensis subsp. israelensis spores were found to persist in soils of the wetland reserve at concentrations of up to 6.8 log per gram of soil. Continuous accumulation due to regular treatments could be excluded, as the decrease in spores amounted to 95.8% (95% confidence interval, 93.9 to 97.7%). The distribution of spores was correlated to the number of B. thuringiensis subsp. israelensis treatments, the elevation of the sampling point, and the duration of the flooding periods. The number of B. thuringiensis subsp. israelensis treatments was the major factor influencing the distribution of spores in the different topographic zones (P < 0.0001). These findings indicated that B. thuringiensis subsp. israelensis spores are rather immobile after their introduction into the environment. PMID:21498758
Gorris, María Teresa; Alarcon, Benito; Lopez, María M.; Cambra, Mariano
Seven monoclonal antibodies (MAbs) to Erwinia carotovora subsp. atroseptica have been produced. One, called 4G4, reacted with high specificity for serogroup I of E. carotovora subsp. atroseptica, the most common serogroup on potato tubers in different serological assays. Eighty-six strains belonging to different E. carotovora subsp. atroseptica serogroups were assayed. Some strains of serogroup XXII also reacted positively. No cross-reactions were observed against other species of plant pathogenic bacteria or 162 saprophytic bacteria from potato tubers. Only one strain of E. chrysanthemi from potato cross-reacted. A comparison of several serological techniques to detect E. carotovora subsp. atroseptica on potato tubers was performed with MAb 4G4 or polyclonal antibodies. The organism was extracted directly from potato peels of artificially inoculated tubers by soaking or selective enrichment under anaerobiosis in a medium with polypectate. MAb 4G4 was able to detect specifically 240 E. carotovora subsp. atroseptica cells per ml by indirect immunofluorescence and immunofluorescence colony staining and after soaking by ELISA-DAS (double-antibody sandwich enzyme-linked immunosorbent assay) after enrichment. The same amount of cells was detected by using immunolectrotransfer with polyclonal antibodies, and E. carotovora subsp. atroseptica and subsp. carotovora were distinguished by the latter technique. ELISA-DAS using MAb 4G4 with an enrichment step also efficiently detected E. carotovora subsp. atroseptica in naturally infected tubers and plants. PMID:16349293
Frantzen, Cyril A.; Kot, Witold; Pedersen, Thomas B.; Ardö, Ylva M.; Broadbent, Jeff R.; Neve, Horst; Hansen, Lars H.; Dal Bello, Fabio; Østlie, Hilde M.; Kleppen, Hans P.; Vogensen, Finn K.; Holo, Helge
Undefined mesophilic mixed (DL-type) starter cultures are composed of predominantly Lactococcus lactis subspecies and 1–10% Leuconostoc spp. The composition of the Leuconostoc population in the starter culture ultimately affects the characteristics and the quality of the final product. The scientific basis for the taxonomy of dairy relevant leuconostocs can be traced back 50 years, and no documentation on the genomic diversity of leuconostocs in starter cultures exists. We present data on the Leuconostoc population in five DL-type starter cultures commonly used by the dairy industry. The analyses were performed using traditional cultivation methods, and further augmented by next-generation DNA sequencing methods. Bacterial counts for starter cultures cultivated on two different media, MRS and MPCA, revealed large differences in the relative abundance of leuconostocs. Most of the leuconostocs in two of the starter cultures were unable to grow on MRS, emphasizing the limitations of culture-based methods and the importance of careful media selection or use of culture independent methods. Pan-genomic analysis of 59 Leuconostoc genomes enabled differentiation into twelve robust lineages. The genomic analyses show that the dairy-associated leuconostocs are highly adapted to their environment, characterized by the acquisition of genotype traits, such as the ability to metabolize citrate. In particular, Leuconostoc mesenteroides subsp. cremoris display telltale signs of a degenerative evolution, likely resulting from a long period of growth in milk in association with lactococci. Great differences in the metabolic potential between Leuconostoc species and subspecies were revealed. Using targeted amplicon sequencing, the composition of the Leuconostoc population in the five commercial starter cultures was shown to be significantly different. Three of the cultures were dominated by Ln. mesenteroides subspecies cremoris. Leuconostoc pseudomesenteroides dominated in two of
Escalante, Adelfo; Giles-Gómez, Martha; Hernández, Georgina; Córdova-Aguilar, María Soledad; López-Munguía, Agustín; Gosset, Guillermo; Bolívar, Francisco
In this study, the characterization of the bacterial community present during the fermentation of pulque, a traditional Mexican alcoholic beverage from maguey (Agave), was determined for the first time by a polyphasic approach in which both culture and non-culture dependent methods were utilized. The work included the isolation of lactic acid bacteria (LAB), aerobic mesophiles, and 16S rDNA clone libraries from total DNA extracted from the maguey sap (aguamiel) used as substrate, after inoculation with a sample of previously produced pulque and followed by 6-h fermentation. Microbiological diversity results were correlated with fermentation process parameters such as sucrose, glucose, fructose and fermentation product concentrations. In addition, medium rheological behavior analysis and scanning electron microscopy in aguamiel and during pulque fermentation were also performed. Our results showed that both culture and non-culture dependent approaches allowed the detection of several new and previously reported species within the alpha-, gamma-Proteobacteria and Firmicutes. Bacteria diversity in aguamiel was composed by the heterofermentative Leuconostoc citreum, L. mesenteroides, L. kimchi, the gamma-Proteobacteria Erwinia rhapontici, Enterobacter spp. and Acinetobacter radioresistens. Inoculation with previously fermented pulque incorporated to the system microbiota, homofermentative lactobacilli related to Lactobacillus acidophilus, several alpha-Proteobacteria such as Zymomonas mobilis and Acetobacter malorum, other gamma-Proteobacteria and an important amount of yeasts, creating a starting metabolic diversity composed by homofermentative and heterofermentative LAB, acetic and ethanol producing microorganisms. At the end of the fermentation process, the bacterial diversity was mainly composed by the homofermentative Lactobacillus acidophilus, the heterofermentative L. mesenteroides, Lactococcus lactis subsp. lactis and the alpha-Proteobacteria A. malorum. After
Frantzen, Cyril A; Kot, Witold; Pedersen, Thomas B; Ardö, Ylva M; Broadbent, Jeff R; Neve, Horst; Hansen, Lars H; Dal Bello, Fabio; Østlie, Hilde M; Kleppen, Hans P; Vogensen, Finn K; Holo, Helge
Undefined mesophilic mixed (DL-type) starter cultures are composed of predominantly Lactococcus lactis subspecies and 1-10% Leuconostoc spp. The composition of the Leuconostoc population in the starter culture ultimately affects the characteristics and the quality of the final product. The scientific basis for the taxonomy of dairy relevant leuconostocs can be traced back 50 years, and no documentation on the genomic diversity of leuconostocs in starter cultures exists. We present data on the Leuconostoc population in five DL-type starter cultures commonly used by the dairy industry. The analyses were performed using traditional cultivation methods, and further augmented by next-generation DNA sequencing methods. Bacterial counts for starter cultures cultivated on two different media, MRS and MPCA, revealed large differences in the relative abundance of leuconostocs. Most of the leuconostocs in two of the starter cultures were unable to grow on MRS, emphasizing the limitations of culture-based methods and the importance of careful media selection or use of culture independent methods. Pan-genomic analysis of 59 Leuconostoc genomes enabled differentiation into twelve robust lineages. The genomic analyses show that the dairy-associated leuconostocs are highly adapted to their environment, characterized by the acquisition of genotype traits, such as the ability to metabolize citrate. In particular, Leuconostoc mesenteroides subsp. cremoris display telltale signs of a degenerative evolution, likely resulting from a long period of growth in milk in association with lactococci. Great differences in the metabolic potential between Leuconostoc species and subspecies were revealed. Using targeted amplicon sequencing, the composition of the Leuconostoc population in the five commercial starter cultures was shown to be significantly different. Three of the cultures were dominated by Ln. mesenteroides subspecies cremoris. Leuconostoc pseudomesenteroides dominated in two of the
Soerjadi-Liem, A S; Snoeyenbos, G H; Weinack, O M
Resistance of young chicks to Campylobacter fetus subsp. jejuni was substantially increased by early exposure to native gut microflora. Protection was demonstrated against two human isolates and a chicken isolate of C. fetus subsp. jejuni. Significant protection against the chicken isolate was observed throughout a 91-day test period. Infection reached 100% (25/25) in the untreated group at 56 days of age and only 4% (1/25) in the group treated with native gut microflora. Campylobacter fetus subsp. jejuni was isolated from the ceca and less frequently from the gall bladder and liver of chicks that actively shed the bacteria. Cultures of feces from chicks reared on wood-shavings litter were often negative, suggesting that culturing litter as an indicator of infection has limited value.
Oceanobacillus oncorhynchi subsp. incaldanensis subsp. nov., an alkalitolerant halophile isolated from an algal mat collected from a sulfurous spring in Campania (Italy), and emended description of Oceanobacillus oncorhynchi.
Romano, Ida; Lama, Licia; Nicolaus, Barbara; Poli, Annarita; Gambacorta, Agata; Giordano, Assunta
A halophilic, alkalitolerant bacterium, strain 20AGT, was isolated from an algal mat collected from a sulfurous spring located in Santa Maria Incaldana (Mondragone, Campania Region, southern Italy). The isolate is Gram-positive, ferments several carbohydrates and has motile, rod-shaped cells that do not sporulate. The isolate grows at pH 6.5-9.5 and in 5-20 % NaCl. On the basis of 16S rRNA gene sequence similarity, the strain was shown to belong to the genus Oceanobacillus; strain 20AGT showed 96.6 % 16S rRNA gene sequence similarity to the type strain of Oceanobacillus iheyensis, DSM 14371T, and 99.5 % similarity to Oceanobacillus oncorhynchi NCIMB 14022T. Levels of DNA-DNA relatedness between strain 20AGT and O. iheyensis DSM 14371T and O. oncorhynchi NCIMB 14022T were respectively 29.4 and 59.0 %. The G+C content of the DNA of strain 20AGT was 40.1 mol%. The predominant respiratory quinone was MK-7, phosphatidylglycerol and phosphatidylcholine were the predominant polar lipids and minor phospholipids were also detected. ai-C14 : 0, ai-C15 : 0 and i-C15 : 0 were the major fatty acids. Strain 20AGT accumulated osmolytes and produced exopolysaccharide. On the basis of phenotypic characteristics, phylogenetic data and DNA-DNA relatedness data, isolate 20AGT should be designated as the type strain of a subspecies of Oceanobacillus oncorhynchi, for which the name Oceanobacillus oncorhynchi subsp incaldanensis subsp. nov. is proposed. The type strain is 20AGT (=DSM 16557T = ATCC BAA-954T).
Luechtefeld, N W; Wang, W L; Blaser, M J; Reller, L B
Immediate culturing of fecal specimens is not always possible, and appropriate methods for transport and storage of Campylobacter fetus subsp. jejuni specimens have not been fully evaluated. Using nine techniques, we studied the survival of C. fetus subsp. jejuni in cecal specimens from infected turkeys. The organisms survived in specimens held without transport medium for 3 to 15 days (median, 9 days) at 4 degrees C, and 2 to 9 days (median, 4 days) at 25 degrees C. Only 20% of specimens frozen for 24 h at either -20 or -70 degrees C yielded C. fetus subsp. jejuni. Specimens dried on filter paper strips were negative for C. fetus subsp. jejuni within 1.5 h. Cary-Blair medium with decreased agar was the best of the six transport media tested, it enabled recovery of the organism from 100% (3 days) and 71% (7 days) of cecal samples held at 4 degrees C and 94% (3 days) and 85% (7 days) of cecal specimens held at 25 degrees C. In contrast, more than half of all cecal specimens held at 4 or 25 degrees C in Culturettes or buffered glycerol saline were negative by 3 days, and all were negative at 7 days. Results with the other three media studied (Campy-thio, thioglycolate medium, and alkaline peptone water) were intermediate. Overnight incubation of specimens in alkaline peptone water at 37 or 42 degrees C did not enhance recovery of C. fetus subsp. jejuni. Therefore, refrigeration without a transport medium is satisfactory for up to 3 days for recovery of C. fetus subsp. jejuni from specimens, however, we recommend the use of Cary-Blair medium with decreased agar for specimens that must be transported or stored for longer than 3 days and for rectal swabs, to prevent drying.
Mendes, Filipa; Sieuwerts, Sander; de Hulster, Erik; Almering, Marinka J. H.; Luttik, Marijke A. H.; Pronk, Jack T.; Smid, Eddy J.; Bron, Peter A.
Mixed populations of Saccharomyces cerevisiae yeasts and lactic acid bacteria occur in many dairy, food, and beverage fermentations, but knowledge about their interactions is incomplete. In the present study, interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus, two microorganisms that co-occur in kefir fermentations, were studied during anaerobic growth on lactose. By combining physiological and transcriptome analysis of the two strains in the cocultures, five mechanisms of interaction were identified. (i) Lb. delbrueckii subsp. bulgaricus hydrolyzes lactose, which cannot be metabolized by S. cerevisiae, to galactose and glucose. Subsequently, galactose, which cannot be metabolized by Lb. delbrueckii subsp. bulgaricus, is excreted and provides a carbon source for yeast. (ii) In pure cultures, Lb. delbrueckii subsp. bulgaricus grows only in the presence of increased CO2 concentrations. In anaerobic mixed cultures, the yeast provides this CO2 via alcoholic fermentation. (iii) Analysis of amino acid consumption from the defined medium indicated that S. cerevisiae supplied alanine to the bacterium. (iv) A mild but significant low-iron response in the yeast transcriptome, identified by DNA microarray analysis, was consistent with the chelation of iron by the lactate produced by Lb. delbrueckii subsp. bulgaricus. (v) Transcriptome analysis of Lb. delbrueckii subsp. bulgaricus in mixed cultures showed an overrepresentation of transcripts involved in lipid metabolism, suggesting either a competition of the two microorganisms for fatty acids or a response to the ethanol produced by S. cerevisiae. This study demonstrates that chemostat-based transcriptome analysis is a powerful tool to investigate microbial interactions in mixed populations. PMID:23872557
Foddai, Antonio; Elliott, Christopher T; Grant, Irene R
A commercially available phage amplification assay, FASTPlaqueTB (Biotec Laboratories, Ipswich, United Kingdom), when used according to the manufacturer's instructions, does not permit accurate enumeration of Mycobacterium avium subsp. paratuberculosis. The aim of this study was to optimize the phage amplification assay conditions to permit accurate quantification of viable M. avium subsp. paratuberculosis cells. The burst time for M. avium subsp. paratuberculosis was initially determined to inform decisions about optimal incubation time before plating, and then other test parameters were altered to evaluate how the correlation between plaque and colony counts was affected. The D29 mycobacteriophage replicates more slowly in M. avium subsp. paratuberculosis than in Mycobacterium smegmatis (used to optimize the commercial test originally), and the mean burst time for four M. avium subsp. paratuberulosis strains was 210 +/- 36.8 min at 37 degrees C compared to 63 +/- 17.5 min for M. smegmatis mc(2) 155. To achieve 100% correlation between plaque and colony counts, the optimized phage assay includes the following: (i) resuspension of the samples to be tested in Middlebrook 7H9 broth containing 10% oleic acid-albumin-dextrose-catalase and 2 mM calcium chloride, followed by overnight incubation at 37 degrees C before performance of the phage assay; (ii) a 2-h incubation of the sample with D29 mycobacteriophage before viricide treatment; and (iii) a further 90-min incubation after viricide treatment and neutralization up to the burst time (total incubation time, 210 min) before plating with M. smegmatis mc(2) 155 in 7H9 agar. The optimized phage amplification assay was able to detect 1 to 10 CFU/ml of M. avium subsp. paratuberculosis in spiked milk or broth within 48 h, as demonstrated by the results of several blind trials.
Szabo, Jeffrey G; Rice, Eugene W; Bishop, Paul L
Persistence of Bacillus atrophaeus subsp. globigii spores on corroded iron coupons in drinking water was studied using a biofilm annular reactor. Spores were inoculated at 10(6) CFU/ml in the dechlorinated reactor bulk water. The dechlorination allowed for observation of the effects of hydraulic shear and biofilm sloughing on persistence. Approximately 50% of the spores initially adhered to the corroded iron surface were not detected after 1 month. Addition of a stable 10 mg/liter free chlorine residual after 1 month led to a 2-log(10) reduction of adhered B. atrophaeus subsp. globigii, but levels on the coupons quickly stabilized thereafter. Increasing the free chlorine concentration to 25 or 70 mg/liter had no additional effect on inactivation. B. atrophaeus subsp. globigii spores injected in the presence of a typical distribution system chlorine residual (approximately 0.75 mg/liter) resulted in a steady reduction of adhered B. atrophaeus subsp. globigii over 1 month, but levels on the coupons eventually stabilized. Adding elevated chlorine levels (10, 25, and 70 mg/liter) after 1 month had no effect on the rate of inactivation. Decontamination with elevated free chlorine levels immediately after spore injection resulted in a 3-log(10) reduction within 2 weeks, but the rate of inactivation leveled off afterward. This indicates that free chlorine did not reach portions of the corroded iron surface where B. atrophaeus subsp. globigii spores had adhered. B. atrophaeus subsp. globigii spores are capable of persisting for an extended time in the presence of high levels of free chlorine.
Background Several plants traditionally used in treatment of a variety of infections in South Africa are reported in ethnobotanical surveys. Many of these plants including Ziziphus mucronata subsp. mucronata lack scientific reports to support their medicinal importance. Methods The antioxidant activities and phenolic contents of the acetone, ethanol and aqueous extracts of the stems of Z. mucronata subsp. mucronata were evaluated using in vitro standard methods. The total phenol, total flavonoids and proanthocyanidin content were determined spectrophotometrically. Quercetin, Tannic acid and catechin equivalents were used for these parameters. The antioxidant activities of the stem bark extracts of this plant were determined by ABTS, DPPH, and ferrous reducing antioxidant property (FRAP) methods. Results The quantity of the phenolic compounds, flavonoids and proanthocyanidins detected differ significantly in the various extracts. The phenolics were significantly higher than the flavonoids and proanthocyanidin contents in all the extracts investigated. The ferric reducing ability and the radical scavenging activities of the extracts were very high and dose-dependent. The ethanol extract had the highest antioxidant activity, followed by the acetone extract while the aqueous extract was the least active. Reacting with ABTS, the 50% inhibitory concentrations (IC50) were (0.0429 ± 0.04 mg/ml) for aqueous, (0.0317 ± 0.04 mg/ml) for acetone and (0.0306 ± 0.04 mg/ml) for ethanol extracts while they inhibited DPPH radical with 50% inhibitory concentration (IC50) values of 0.0646 ± 0.02 mg/ml (aqueous), 0.0482 ± 0.02 mg/ml (acetone) and 0.0422 ± 0.03 mg/ml (ethanol). Conclusions A correlation between the antioxidant activity and the total phenolic contents of the extracts indicated that phenolic compounds were the dominant contributors to the antioxidant activity of the plant. This study, therefore, demonstrated that Z. mucronata subsp. mucronata has strong antioxidant
Pedroso, D.L.; Dogenski, M.; Thomazini, M.; Heinemann, R.J.B.; Favaro-Trindade, C.S.
In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (103 CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at −18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved. PMID:24516445
Pedroso, D L; Dogenski, M; Thomazini, M; Heinemann, R J B; Favaro-Trindade, C S
In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10(3) CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.
Xu, Jinlong; Zhao, Qizhi; Wei, Lei; Yang, Yu; Xu, Rui; Yu, Nengjiang; Zhao, Yimin
In traditional medicine, Bauhinia glauca subsp. hupehana has long been used as an analgesic agent in China. The aim of this study was to evaluate the antinociceptive activity of the ethanol extract of the aerial parts of B. glauca subsp. hupehana (BHE) in rats and its chemical fingerprint. The antinociceptive activity of BHE was assessed in mice using chemically and heat–induced pain models, such as the acetic acid–induced writhing, hot plate, tail–flick and glutamate tests. Naltrexone hydrochloride, a non–selective opioid receptor antagonist, was utilized to determine the involvement of the opioid system. In addition to this, the involvements of the cGMP and ATP–sensitive K+ channel pathways were also detected using methylene blue and glibenclamide. The oral administration of BHE (at doses of 50, 100 and 200 mg/kg) produced significant and dose–related inhibitions in both the chemically and heat–induced pain models. Interestingly, in the abdominal constriction test, when the dose of BHE was increased to 800 mg/kg (p.o., n = 10), the inhibition rate was 100%. The antinociceptive mechanism may involve the cGMP pathway and ATP sensitive K+ channel pathway. The central antinociceptive effect was not antagonized by naltrexone. One phenolic acid, one lignin and five flavonoids were isolated from BHE. The antinociceptive activity of BHE was most likely due to the presence of the flavonoids. The acute toxicity results showed that BHE was safe at a high dose (2 g/kg, p.o.). The current investigation demonstrates that B. glauca subsp. hupehana is a potential candidate for the development of novel, non–opioid, analgesic phytomedicines. PMID:25658740
Moro-García, Marco Antonio; Alonso-Arias, Rebeca; Baltadjieva, Maria; Fernández Benítez, Carlos; Fernández Barrial, Manuel Amadeo; Díaz Ruisánchez, Enrique; Alonso Santos, Ricardo; Alvarez Sánchez, Magdalena; Saavedra Miján, Juan; López-Larrea, Carlos
Throughout life, there is an aging of the immune system that causes impairment of its defense capability. Prevention or delay of this deterioration is considered crucial to maintain general health and increase longevity. We evaluated whether dietary supplementation with Lactobacillus delbrueckii subsp. bulgaricus 8481 could enhance the immune response in the elderly. This multi-center, double-blind, and placebo controlled study enrolled 61 elderly volunteers who were randomly assigned to receive either placebo or probiotics. Each capsule of probiotics contained at least 3 × 10(7) L. delbrueckii subsp. bulgaricus 8481. Individuals in the study were administered three capsules per day for 6 months. Blood samples were obtained at baseline (time 0), end of month 3, and month 6. We characterized cell subpopulations, measured cytokines by flow cytometry, quantified T cell receptor excision circle (TREC) by real-time PCR (RT-PCR), and determined human β-defensin-2 (hBD-2) concentrations and human cytomegalovirus (CMV) titers by enzyme-linked immunosorbent assay (ELISA). Elderly responded to the intake of probiotic with an increase in the percentage of NK cells, an improvement in the parameters defining the immune risk profile (IRP), and an increase in the T cell subsets that are less differentiated. The probiotic group also showed decreased concentrations of the pro-inflammatory cytokine IL-8 but increased antimicrobial peptide hBD-2. These effects disappeared within 6 months of stopping the probiotic intake. Immunomodulation induced by L. delbrueckii subsp. bulgaricus 8481 could favor the maintenance of an adequate immune response, mainly by slowing the aging of the T cell subpopulations and increasing the number of immature T cells which are potential responders to new antigens.
Burns, Patricia; Sánchez, Borja; Vinderola, Gabriel; Ruas-Madiedo, Patricia; Ruiz, Lorena; Margolles, Abelardo; Reinheimer, Jorge; de los Reyes-Gavilán, Clara G
Progressive adaptation to bile might render some lactobacilli able to withstand physiological bile salt concentrations. In this work, the adaptation to bile was evaluated on previously isolated dairy strains of Lactobacillus delbrueckii subsp. lactis 200 and L. delbrueckii subsp. lactis 200+, a strain derived thereof with stable bile-resistant phenotype. The adaptation to bile was obtained by comparing cytosolic proteomes of both strains grown in the presence or absence of bile. Proteomics were complemented with physiological studies on both strains focusing on glycolytic end-products, the ability to adhere to the human intestinal epithelial cell line HT29-MTX and survival to simulated gastrointestinal conditions. Protein pattern comparison of strains grown with and without bile allowed us to identify 9 different proteins whose production was regulated by bile in both strains, and 17 proteins that showed differences in their levels between the parental and the bile-resistant derivative. These included general stress response chaperones, proteins involved in transcription and translation, in peptidoglycan/exopolysaccharide biosynthesis, in the lipid and nucleotide metabolism and several glycolytic and pyruvate catabolism enzymes. Differences in the level of metabolic end-products of the sugar catabolism were found between the strains 200 and 200+. A decrease in the adhesion of both strains to the intestinal cell line was detected in the presence of bile. In simulated gastric and intestinal juices, a protective effect was exerted by milk improving the survival of both microorganisms. These results indicate that bile tolerance in L. delbrueckii subsp. lactis involves several mechanisms responding to the deleterious impact of bile salts on bacterial physiology.
Nikolaichik, E.A.; Pesnyakevich, A.G.
A circular genetic map of Erwinia carotovora subsp. atroseptica 3-2 was constructed on the basis of the R471a plasmid and Tn5 and Tn9 using Hfr-like donors. Forty-six genes, including phytopathogenicity genes, were located on the basis of interrupted mating experiment results and analysis of coinheritance of markers on a map of 183 min in length. The similarity and differences of chromosomal genetic maps of Erwinia genus bacteria are discussed. 23 refs., 2 figs., 4 tabs.
Brito, Miriam; Fernández-Rodríguez, Thaly; Garrido, Mario José; Mejías, Alexander; Romano, Mirtha; Marys, Edgloris
Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained amplicons showed 84%–74% similarity to corresponding sequences of Cowpea mild mottle virus (CPMMV) isolates deposited in the GenBank database. This is the first report of CPMMV in Venezuela and is thought to be the first report of CPMMV infecting yardlong bean. PMID:23242372
Moravkova, Monika; Lamka, Jiri; Slany, Michal; Pavlik, Ivo
IS901 RFLP analysis of 36 Mycobacterium avium subsp. avium (MAA) isolates from 15 pheasants (Phasianus colchicus) and two goshawks (Accipiter gentilis) from four pheasant farms was performed. Using this method, six different IS901 RFLP types (E, F, G, M, Q, and V) were identified. The distribution of IS901 RFLP profiles was tightly linked to individual flocks. Matching IS901 RFLP profiles observed in the present study indicate MAA transmission between pheasants and goshawks in the same locality. In two flocks, different pheasants within a flock as well as in various organs of five individual pheasants were found to have two distinct IS901 RFLP profiles.
Birmes, Franziska S; Wolf, Timo; Kohl, Thomas A; Rüger, Kai; Bange, Franz; Kalinowski, Jörn; Fetzner, Susanne
Pseudomonas aeruginosa employs 2-heptyl-3-hydroxy-4(1H)-quinolone (the Pseudomonas quinolone signal, PQS) and 2-heptyl-4(1H)-quinolone (HHQ) as quorum sensing signal molecules, which contribute to a sophisticated regulatory network controlling the production of virulence factors and antimicrobials. We demonstrate that Mycobacterium abscessus(T) and clinical M. abscessus isolates are capable of degrading these alkylquinolone signals. Genome sequences of 50 clinical M. abscessus isolates indicated the presence of aqdRABC genes, contributing to fast degradation of HHQ and PQS, in M. abscessus subsp. abscessus strains, but not in M. abscessus subsp. bolletii and M. abscessus subsp. massiliense isolates. A subset of 18 M. a. subsp. abscessus isolates contained the same five single nucleotide polymorphisms (SNPs) compared to the aqd region of the type strain. Interestingly, representatives of these isolates showed faster PQS degradation kinetics than the M. abscessus type strain. One of the SNPs is located in the predicted promoter region of the aqdR gene encoding a putative transcriptional regulator, and two others lead to a variant of the AqdC protein termed AqdC(II), which differs in two amino acids from AqdC(I) of the type strain. AqdC, the key enzyme of the degradation pathway, is a PQS dioxygenase catalyzing quinolone ring cleavage. While transcription of aqdR and aqdC is induced by PQS, transcript levels in a representative of the subset of 18 isolates were not significantly altered despite the detected SNP in the promoter region. However, purified recombinant AqdC(II) and AqdC(I) exhibit different kinetic properties, with approximate apparent Km values for PQS of 14 μM and 37 μM, and kcat values of 61 s(-1) and 98 s(-1), respectively, which may (at least in part) account for the observed differences in PQS degradation rates of the strains. In co-culture experiments of P. aeruginosa PAO1 and M. abscessus, strains harboring the aqd genes reduced the PQS levels
Pappas, Katherine M.; Kouvelis, Vassili N.; Saunders, Elizabeth; Brettin, Thomas S.; Bruce, David; Detter, Chris; Balakireva, Mariya; Han, Cliff S.; Savvakis, Giannis; Kyrpides, Nikos C.; Typas, Milton A.
Zymomonas mobilis ATCC 10988 is the type strain of the Z. mobilis subsp. mobilis taxon, members of which are some of the most rigorous ethanol-producing bacteria. Isolated from Agave cactus fermentations in Mexico, ATCC 10988 is one of the first Z. mobilis strains to be described and studied. Its robustness in sucrose-substrate fermentations, physiological characteristics, large number of plasmids, and overall genomic plasticity render this strain important to the study of the species. Here we report the finishing and annotation of the ATCC 10988 chromosomal and plasmid genome. PMID:21725006
He, Jin; Wang, Jieping; Yin, Wen; Shao, Xiaohu; Zheng, Huajun; Li, Mingshun; Zhao, Youwen; Sun, Ming; Wang, Shengyue; Yu, Ziniu
Bacillus thuringiensis has been widely used as an agricultural biopesticide for a long time. As a producing strain, B. thuringiensis subsp. chinensis strain CT-43 is highly toxic to lepidopterous and dipterous insects. It can form various parasporal crystals consisting of Cry1Aa3, Cry1Ba1, Cry1Ia14, Cry2Aa9, and Cry2Ab1. During fermentation, it simultaneously generates vegetative insecticidal protein Vip3Aa10 and the insecticidal nucleotide analogue thuringiensin. Here, we report the finished, annotated genome sequence of B. thuringiensis strain CT-43.
He, Jin; Wang, Jieping; Yin, Wen; Shao, Xiaohu; Zheng, Huajun; Li, Mingshun; Zhao, Youwen; Sun, Ming; Wang, Shengyue; Yu, Ziniu
Bacillus thuringiensis has been widely used as an agricultural biopesticide for a long time. As a producing strain, B. thuringiensis subsp. chinensis strain CT-43 is highly toxic to lepidopterous and dipterous insects. It can form various parasporal crystals consisting of Cry1Aa3, Cry1Ba1, Cry1Ia14, Cry2Aa9, and Cry2Ab1. During fermentation, it simultaneously generates vegetative insecticidal protein Vip3Aa10 and the insecticidal nucleotide analogue thuringiensin. Here, we report the finished, annotated genome sequence of B. thuringiensis strain CT-43. PMID:21551307
Birmes, Franziska S.; Wolf, Timo; Kohl, Thomas A.; Rüger, Kai; Bange, Franz; Kalinowski, Jörn; Fetzner, Susanne
Pseudomonas aeruginosa employs 2-heptyl-3-hydroxy-4(1H)-quinolone (the Pseudomonas quinolone signal, PQS) and 2-heptyl-4(1H)-quinolone (HHQ) as quorum sensing signal molecules, which contribute to a sophisticated regulatory network controlling the production of virulence factors and antimicrobials. We demonstrate that Mycobacterium abscessusT and clinical M. abscessus isolates are capable of degrading these alkylquinolone signals. Genome sequences of 50 clinical M. abscessus isolates indicated the presence of aqdRABC genes, contributing to fast degradation of HHQ and PQS, in M. abscessus subsp. abscessus strains, but not in M. abscessus subsp. bolletii and M. abscessus subsp. massiliense isolates. A subset of 18 M. a. subsp. abscessus isolates contained the same five single nucleotide polymorphisms (SNPs) compared to the aqd region of the type strain. Interestingly, representatives of these isolates showed faster PQS degradation kinetics than the M. abscessus type strain. One of the SNPs is located in the predicted promoter region of the aqdR gene encoding a putative transcriptional regulator, and two others lead to a variant of the AqdC protein termed AqdCII, which differs in two amino acids from AqdCI of the type strain. AqdC, the key enzyme of the degradation pathway, is a PQS dioxygenase catalyzing quinolone ring cleavage. While transcription of aqdR and aqdC is induced by PQS, transcript levels in a representative of the subset of 18 isolates were not significantly altered despite the detected SNP in the promoter region. However, purified recombinant AqdCII and AqdCI exhibit different kinetic properties, with approximate apparent Km values for PQS of 14 μM and 37 μM, and kcat values of 61 s-1 and 98 s-1, respectively, which may (at least in part) account for the observed differences in PQS degradation rates of the strains. In co-culture experiments of P. aeruginosa PAO1 and M. abscessus, strains harboring the aqd genes reduced the PQS levels, whereas
Crohn's disease (CD) is a chronic, debilitating inflammatory bowel disease with no etiological agent yet identified. Studies have demonstrated that the bacterium Mycobacterium avium subsp. paratuberculosis (MAP) is present in a high percentage of CD patients. Although MAP has been isolated from human specimens, current techniques fail to show the presence of MAP in 100 % of tissues or biopsies obtained from CD patient lesions, and thus MAP cannot meet Koch's postulate as the etiological agent of CD. In this report, the effect of genetic and immune factors as well as the presence of MAP as a potential environmental factor is analyzed.
Brito, Miriam; Fernández-Rodríguez, Thaly; Garrido, Mario José; Mejías, Alexander; Romano, Mirtha; Marys, Edgloris
Yardlong bean (Vigna unguiculata subsp. sesquipedalis) plants with virus-like systemic mottling and leaf distortion were observed in both experimental and commercial fields in Aragua State, Venezuela. Symptomatic leaves were shown to contain carlavirus-like particles. RT-PCR analysis with carlavirus-specific primers was positive in all tested samples. Nucleotide sequences of the obtained amplicons showed 84%-74% similarity to corresponding sequences of Cowpea mild mottle virus (CPMMV) isolates deposited in the GenBank database. This is the first report of CPMMV in Venezuela and is thought to be the first report of CPMMV infecting yardlong bean.
Zuljan, Federico; Espariz, Martín; Blancato, Victor S.; Esteban, Luis; Alarcón, Sergio
We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains. PMID:26847906
Zuljan, Federico; Espariz, Martín; Blancato, Victor S; Esteban, Luis; Alarcón, Sergio; Magni, Christian
We report the draft genome sequence of Lactococcus lactis subsp. lactis bv. diacetylactis CRL264, a natural strain isolated from artisanal cheese from northwest Argentina. L. lactis subsp. lactis bv. diacetylactis is one of the most important microorganisms used as starter culture around the world. The CRL264 strain constitutes a model microorganism in the studies on the generation of aroma compounds (diacetyl, acetoin, and 2,3-butanediol) by lactic acid bacteria. Our genome analysis shows similar genetic organization to other available genomes of L. lactis bv. diacetylactis strains.
Waldron, Anna M.; Galea, Francesca; Whittington, Ann-Michele; Saunders, Vanessa F.; Begg, Douglas J.; de Silva, Kumudika; Purdie, Auriol C.; Whittington, Richard J.
Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid methods for the detection of M. avium subsp. paratuberculosis based on PCR have been reported, but comprehensive validation data are lacking. We describe here a new test, the high-throughput-Johnes (HT-J), to detect M. avium subsp. paratuberculosis in feces. Its diagnostic accuracy was compared with that of liquid radiometric (Bactec) fecal culture using samples from cattle (1,330 samples from 23 herds) and sheep (596 samples from 16 flocks). The multistage protocol involves the recovery of M. avium subsp. paratuberculosis cells from a fecal suspension, cell rupture by bead beating, extraction of DNA using magnetic beads, and IS900 quantitative PCR. The limit of detection of the assay was 0.0005 pg, and the limit of quantification was 0.005 pg M. avium subsp. paratuberculosis genomic DNA. Only M. avium subsp. paratuberculosis was detected from a panel of 51 mycobacterial isolates, including 10 with IS900-like sequences. Of the 549 culture-negative fecal samples from unexposed herds and flocks, 99% were negative in the HT-J test, while 60% of the bovine- and 84% of the ovine-culture-positive samples were positive in the HT-J test. As similar total numbers of samples from M. avium subsp. paratuberculosis-exposed animals were positive in culture and HT-J tests in both species, and as the results of a McNemar's test were not significant, these methods probably have similar sensitivities, but the true diagnostic sensitivities of these tests are unknown. These validation data meet the consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis and
Fischer, Anne; Santana-Cruz, Ivette; Hegerman, Jan; Gourlé, Hadrien; Schieck, Elise; Lambert, Mathieu; Nadendla, Suvarna; Wesonga, Hezron; Miller, Rachel A; Vashee, Sanjay; Weber, Johann; Meens, Jochen; Frey, Joachim; Jores, Joerg
Members of the Mycoplasma mycoides cluster' represent important livestock pathogens worldwide. Mycoplasma mycoides subsp. mycoides is the etiologic agent of contagious bovine pleuropneumonia (CBPP), which is still endemic in many parts of Africa. We report the genome sequences and annotation of two frequently used challenge strains of Mycoplasma mycoides subsp. mycoides, Afadé and B237. The information provided will enable downstream 'omics' applications such as proteomics, transcriptomics and reverse vaccinology approaches. Despite the absence of Mycoplasma pneumoniae like cyto-adhesion encoding genes, the two strains showed the presence of protrusions. This phenotype is likely encoded by another set of genes.
Dempsey, M. P.; Dobson, M.; Zhang, C.; Zhang, M.; Lion, C.; Gutiérrez-Martín, C. B.; Iwen, P. C.; Fey, P. D.; Olson, M. E.; Niemeyer, D.; Francesconi, S.; Crawford, R.; Stanley, M.; Rhodes, J.; Wagner, D. M.; Vogler, A. J.; Birdsell, D.; Keim, P.; Johansson, A.; Hinrichs, S. H.; Benson, A. K.
Francisella tularensis subsp. holarctica is widely disseminated in North America and the boreal and temperate regions of the Eurasian continent. Comparative genomic analyses identified a 1.59-kb genomic deletion specific to F. tularensis subsp. holarctica isolates from Spain and France. Phylogenetic analysis of strains carrying this deletion by multiple-locus variable-number tandem repeat analysis showed that the strains comprise a highly related set of genotypes, implying that these strains were recently introduced or recently emerged by clonal expansion in France and the Iberian Peninsula. PMID:17890329
Plain, Karren M; Marsh, Ian B; Waldron, Anna M; Galea, Francesca; Whittington, Ann-Michele; Saunders, Vanessa F; Begg, Douglas J; de Silva, Kumudika; Purdie, Auriol C; Whittington, Richard J
Johne's disease (JD) is a chronic enteric disease caused by Mycobacterium avium subsp. paratuberculosis that affects ruminants. Transmission occurs by the fecal-oral route. A commonly used antemortem diagnostic test for the detection of M. avium subsp. paratuberculosis in feces is liquid culture; however, a major constraint is the 2- to 3-month incubation period needed for this method. Rapid methods for the detection of M. avium subsp. paratuberculosis based on PCR have been reported, but comprehensive validation data are lacking. We describe here a new test, the high-throughput-Johnes (HT-J), to detect M. avium subsp. paratuberculosis in feces. Its diagnostic accuracy was compared with that of liquid radiometric (Bactec) fecal culture using samples from cattle (1,330 samples from 23 herds) and sheep (596 samples from 16 flocks). The multistage protocol involves the recovery of M. avium subsp. paratuberculosis cells from a fecal suspension, cell rupture by bead beating, extraction of DNA using magnetic beads, and IS900 quantitative PCR. The limit of detection of the assay was 0.0005 pg, and the limit of quantification was 0.005 pg M. avium subsp. paratuberculosis genomic DNA. Only M. avium subsp. paratuberculosis was detected from a panel of 51 mycobacterial isolates, including 10 with IS900-like sequences. Of the 549 culture-negative fecal samples from unexposed herds and flocks, 99% were negative in the HT-J test, while 60% of the bovine- and 84% of the ovine-culture-positive samples were positive in the HT-J test. As similar total numbers of samples from M. avium subsp. paratuberculosis-exposed animals were positive in culture and HT-J tests in both species, and as the results of a McNemar's test were not significant, these methods probably have similar sensitivities, but the true diagnostic sensitivities of these tests are unknown. These validation data meet the consensus-based reporting standards for diagnostic test accuracy studies for paratuberculosis and
Chemical differences in volatiles between Melittis melissophyllum L. subsp. melissophyllum and subsp. albida (Guss) P. W. Ball (Lamiaceae) determined by solid-phase microextraction (SPME) coupled with GC/FID and GC/MS.
Maggi, Filippo; Conti, Fabio; Cristalli, Gloria; Giuliani, Claudia; Papa, Fabrizio; Sagratini, Gianni; Vittori, Sauro
Melittis melissophyllum (Lamiaceae) is a perennial herb, typical of woody places, occurring in Italy with two subspecies, i.e., melissophyllum and albida. So far, the classification of these two taxa was only based on morphology, i.e., the presence of glandular trichomes, the dimension of the leaves, and the number of teeth on each side as the main discriminant characters. To find marker compounds to chemically discriminate the subsp. melissophyllum with respect to the subsp. albida, a solid-phase microextraction SPME analysis coupled with GC/FID (=flame ionization detector) and GC/MS was carried out. SPME proved to be a chemotaxonomically useful technique that permitted a clearly differentiation of the two subspecies at headspace level. The subsp. melissophyllum was characterized by high amount of the mushroom alcohol oct-1-en-3-ol and the phenolic coumarin, whilst the subsp. albida exhibited a high content in monoterpenes and sesquiterpenes, α-pinene, sabinene, and (E)-caryophyllene being the major compounds. Multivariate chemometric techniques, such as cluster analysis (CA) and principal-component analysis (PCA), were used to support chemical data and characterize the population according to the taxonomy. In addition, the micromorphology and distribution of glandular trichomes of both subspecies were studied by scanning electron microscopy (SEM).
Darsonval, A; Darrasse, A; Durand, K; Bureau, C; Cesbron, S; Jacques, M-A
Deciphering the mechanisms enabling plant-pathogenic bacteria to disperse, colonize, and survive on their hosts provides the necessary basis to set up new control methods. We evaluated the role of bacterial attachment and biofilm formation in host colonization processes for Xanthomonas fuscans subsp. fuscans on its host. This bacterium is responsible for the common bacterial blight of bean (Phaseolus vulgaris), a seedborne disease. The five adhesin genes (pilA, fhab, xadA1, xadA2, and yapH) identified in X. fuscans subsp. fuscans CFBP4834-R strain were mutated. All mutants were altered in their abilities to adhere to polypropylene or seed. PilA was involved in adhesion and transmission to seed, and mutation of pilA led to lower pathogenicity on bean. YapH was required for adhesion to seed, leaves, and abiotic surfaces but not for in planta transmission to seed or aggressiveness on leaves. Transmission to seed through floral structures did not require any of the known adhesins. Conversely, all mutants tested, except in yapH, were altered in their vascular transmission to seed. In conclusion, we showed that adhesins are implicated in the various processes leading to host phyllosphere colonization and transmission to seed by plant-pathogenic bacteria.
Ashman, Tia-Lynn; Tennessen, Jacob A.; Dalton, Rebecca M.; Govindarajulu, Rajanikanth; Koski, Matthew H.; Liston, Aaron
Gynodioecy, the coexistence of females and hermaphrodites, occurs in 20% of angiosperm families and often enables transitions between hermaphroditism and dioecy. Clarifying mechanisms of sex determination in gynodioecious species can thus illuminate sexual system evolution. Genetic determination of gynodioecy, however, can be complex and is not fully characterized in any wild species. We used targeted sequence capture to genetically map a novel nuclear contributor to male sterility in a self-pollinated hermaphrodite of Fragaria vesca subsp. bracteata from the southern portion of its range. To understand its interaction with another identified locus and possibly additional loci, we performed crosses within and between two populations separated by 2000 km, phenotyped the progeny and sequenced candidate markers at both sex-determining loci. The newly mapped locus contains a high density of pentatricopeptide repeat genes, a class commonly involved in restoration of fertility caused by cytoplasmic male sterility. Examination of all crosses revealed three unlinked epistatically interacting loci that determine sexual phenotype and vary in frequency between populations. Fragaria vesca subsp. bracteata represents the first wild gynodioecious species with genomic evidence of both cytoplasmic and nuclear genes in sex determination. We propose a model for the interactions between these loci and new hypotheses for the evolution of sex determining chromosomes in the subdioecious and dioecious Fragaria. PMID:26483011
Kuzu, Secil Berna; Güvenmez, Hatice Korkmaz; Denizci, Aziz Akin
This paper reports the isolation and identification of chitinase-producing Bacillus from chitin-containing wastes, production of a thermostable and alkaline chitinasese, and enzyme characterization. Bacillus thuringiensis subsp. kurstaki HBK-51 was isolated from soil and was identified. Chitinase was obtained from supernatant of B. thuringiensis HBK-51 strain and showed its optimum activity at 110°C and at pH 9.0. Following 3 hours of incubation period, the enzyme showed a high level of activity at 110°C (96% remaining activity) and between pH 9.0 and 12.0 (98% remaining activity). Considering these characteristics, the enzyme was described as hyperthermophile-thermostable and highly alkaline. Two bands of the enzyme weighing 50 and 125 kDa were obtained following 12% SDS-PAGE analyses. Among the metal ions and chemicals used, Ni2+ (32%), K+ (44%), and Cu2+ (56%) increased the enzyme activity while EDTA (7%), SDS (7%), Hg2+ (11%), and ethyl-acetimidate (20%) decreased the activity of the enzyme. Bacillus thuringiensis subsp. kurstaki HBK-51 is an important strain which can be used in several biotechnological applications as a chitinase producer. PMID:23304523
Huang, B L; Cheng, C; Zhang, G Y; Su, J J; Zhi, Y; Xu, S S; Cai, D T; Zhang, X K; Huang, B Q
Nicotianamine (NA) is a ubiquitous metabolite in plants that bind heavy metals, is crucial for metal homeostasis, and is also an important metal chelator that facilitates long-distance metal transport and sequestration. NA synthesis is catalyzed by the enzyme nicotianamine synthase (NAS). Eruca vesicaria subsp sativa is highly tolerant to Ni, Pb, and Zn. In this study, a gene encoding EvNAS was cloned and characterized in E. vesicaria subsp sativa. The full-length EvNAS cDNA sequence contained a 111-bp 5'-untranslated region (UTR), a 155-bp 3'-UTR, and a 966-bp open reading frame encoding 322-amino acid residues. The EvNAS genomic sequence contained no introns, which is similar to previously reported NAS genes. The deduced translation of EvNAS contained a well-conserved NAS domain (1-279 amino acids) and an LIKI-CGEAEG box identical to some Brassica NAS and to the LIRL-box in most plant NAS, which is essential for DNA binding. Phylogenetic analysis indicated that EvNAS was most closely related to Brassica rapa NAS3 within the Cruciferae, followed by Thlaspi NAS1, Camelina NAS3, and Arabidopsis NAS3. A reverse transcription-polymerase chain reaction indicated that EvNAS expression was greatest in the leaves, followed by the flower buds and hypocotyls. EvNAS was moderately expressed in the roots.
del Rio, Beatriz; Linares, Daniel M.; Redruello, Begoña; Martin, Maria Cruz; Fernandez, Maria; de Jong, Anne; Kuipers, Oscar P.; Ladero, Victor; Alvarez, Miguel A.
Lactococcus lactis subsp. cremoris CECT 8666 (formerly GE2-14) is a dairy strain that catabolizes agmatine (a decarboxylated derivative of arginine) into the biogenic amine putrescine by the agmatine deiminase (AGDI) pathway . The AGDI cluster of L. lactis is composed by five genes aguR, aguB, aguD, aguA and aguC. The last four genes are responsible for the deamination of agmatine to putrescine and are co-transcribed as a single policistronic mRNA forming the catabolic operon aguBDAC. aguR encodes a transmembrane protein that functions as a one-component signal transduction system that senses the agmatine concentration of the medium and accordingly regulates the transcription of aguBDAC, which is also transcriptionally regulated by carbon catabolic repression (CCR) via glucose, but not by other sugars such as lactose and galactose , . Here we report the transcriptional profiling of the aguR gene deletion mutant (L. lactis subsp. cremoris CECT 8666 ∆aguR)  compared to the wild type strain, both grown in M17 medium with galactose as carbon source and supplemented with agmatine. The transcriptional profiling data of AguR-regulated genes were deposited in the Gene Expression Omnibus (GEO) database under accession no. GSE59514. PMID:26697381
Alexandrino, André Vessoni; Goto, Leandro Seiji; Novo-Mansur, Maria Teresa Marques
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), is a severe disease of citrus. Xcc presents broad spectrum of citrus hosts including economically important species whereas X. fuscans subsp. aurantifolii–type C (XauC) causes a milder disease and only infects Citrus aurantifolia. Trehalase catalyzes hydrolysis of the disaccharide trehalose, a sugar that has been reported to be related to Xcc pathogenicity. We expressed the recombinant gene product and assessed Xcc trehalase structural and kinetics data. The recombinant protein presented 42.7% of secondary structures in α-helix and 13% in β-sheets, no quaternary structure in solution, and Michaelis-Menten constant (KM) of 0.077 mM and Vmax 55.308 μMol glucose.min-1.mg protein-1 for trehalose. A Xcc mutant strain (XccΔtreA) was produced by gene deletion from Xcc genome. Enzymatic activity of trehalase was determined in Xcc, XauC and XccΔtreA cellular lysates, showing the highest values for XauC in in vitro infective condition and no activity for XccΔtreA. Finally, leaves of Citrus aurantifolia infected with XccΔtreA showed much more drenching and necrosis than those infected by wild type Xcc. We concluded that trehalase contributes to alleviate bacterial virulence and that inability for trehalose hydrolysis may promote higher Xcc infectivity. PMID:27611974
Tatay-Dualde, Juan; Prats-van der Ham, Miranda; de la Fe, Christian; Paterna, Ana; Sánchez, Antonio; Corrales, Juan Carlos; Contreras, Antonio; Tola, Sebastiana; Gómez-Martin, Ángel
Mycoplasma capricolum subsp. capricolum is one of the causative agents of contagious agalactia (CA). Nevertheless, there is still a lack of information about its antimicrobial susceptibility and genetic characteristics. Therefore, the aim of this work was to study the antimicrobial and genetic variability of different Mycoplasma capricolum subsp. capricolum field isolates. For this purpose, the growth inhibition effect of 18 antimicrobials and a multilocus sequence typing (MLST) scheme based on five housekeeping genes (fusA, glpQ, gyrB, lepA and rpoB) were performed on 32 selected field isolates from Italy and Spain.The results showed a wide range of growth inhibitory effects for almost all the antimicrobials studied. Macrolides presented lower efficacy inhibiting Mcc growth than in previous works performed on other CA-causative mycoplasmas. Erythromycin was not able to inhibit the growth of any of the studied strains, contrary to doxycycline, which inhibited the growth of all of them from low concentrations. On the other hand, the study of the concatenated genes revealed a high genetic variability among the different Mcc isolates. Hence, these genetic variations were greater than the ones reported in prior works on other mycoplasma species.
Tan, P S; Pos, K M; Konings, W N
An endopeptidase has been purified to homogeneity from a crude cell extract of Lactococcus lactis subsp. cremoris Wg2 by a procedure that includes diethyl-aminoethane-Sephacel chromatography, phenyl-Sepharose chromatography, hydroxylapatite chromatography, and fast protein liquid chromatography over an anion-exchange column and a hydrophobic-interaction column. Gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated a molecular mass of the purified enzyme of 70,000 Da. The endopeptidase can degrade several oligopeptides into various tetra-, tri-, and dipeptides. The endopeptidase has no aminopeptidase, carboxypeptidase, dipeptidase, or tripeptidase activity. It is optimally active at pH 6.0 to 6.5 and in the temperature range of 30 to 38 degrees C. The enzyme is inactivated by the chemical agents 1,10-phenanthroline, ethylenedinitrilotetraacetate, beta-mercaptoethanol, and phenylmethylsulfonyl fluoride and is inhibited by Cu2+ and Zn2+. The ethylenedinitrilotetraacetate- or 1,10-phenanthroline-treated enzyme can be reactivated by Co2+. Immunoblotting with specific antibodies raised against the purified endopeptidase indicated that the enzyme is also present in other Lactococcus spp., as well as in Lactobacillus spp. and Streptococcus salivarius subsp. thermophilus. Images PMID:1785932
Johansen, Tone Bjordal; Lium, Bjørn; Jørgensen, Anne; Djønne, Berit
Mycobacterium avium subsp. hominissuis is an environmental bacterium causing opportunistic infections in swine, resulting in economic losses. Additionally, the zoonotic aspect of such infections is of concern. In the southeastern region of Norway in 2009 and 2010, an increase in condemnation of pig carcasses with tuberculous lesions was seen at the meat inspection. The use of peat as bedding in the herds was suspected to be a common factor, and a project examining pigs and environmental samples from the herds was initiated. Lesions detected at meat inspection in pigs originating from 15 herds were sampled. Environmental samples including peat from six of the herds and from three peat production facilities were additionally collected. Samples were analysed by culture and isolates genotyped by MLVA analysis. Mycobacterium avium subsp. hominissuis was detected in 35 out of 46 pigs, in 16 out of 20 samples of peat, and in one sample of sawdust. MLVA analysis demonstrated identical isolates from peat and pigs within the same farms. Polyclonal infection was demonstrated by analysis of multiple isolates from the same pig. To conclude, the increase in condemnation of porcine carcasses at slaughter due to mycobacteriosis seemed to be related to untreated peat used as bedding. PMID:25431762
Ledwoń, Aleksandra; Sapierzyński, Rafał; Augustynowicz-Kopeć, Ewa; Szeleszczuk, Piotr; Kozak, Marcin
Beak and feather disease virus- (BFDV-) positive (naturally infected) but clinically healthy budgerigars (Melopsittacus undulatus) were inoculated with two isolates of Mycobacterium avium subsp. avium isolated from naturally infected golden pheasant (Chrysolophus pictus) and peafowl (Pavo cristatus). During a period of more than two months after inoculation, samples of cloacal and crop swabs, faeces, and blood were obtained for BFDV and Mycobacterium avium testing with PCR. Birds were euthanized nine weeks after inoculation. All infected budgerigars developed signs typical of mycobacteriosis, but more advanced clinical and pathological changes were visible in the group infected with the pheasant isolate. Only a few cloacal and crop swab samples were positive for Mycobacterium avium subsp. avium despite advanced pathological changes in the internal organs. In the groups infected with mycobacterium isolates the frequency of BFDV-positive samples was higher than in the control group. In the infected groups the frequency of BFDV was substantially higher in the cloacal swabs of birds inoculated with the pheasant isolate than in the peafowl-isolate-infected group.
Sapierzyński, Rafał; Szeleszczuk, Piotr
Beak and feather disease virus- (BFDV-) positive (naturally infected) but clinically healthy budgerigars (Melopsittacus undulatus) were inoculated with two isolates of Mycobacterium avium subsp. avium isolated from naturally infected golden pheasant (Chrysolophus pictus) and peafowl (Pavo cristatus). During a period of more than two months after inoculation, samples of cloacal and crop swabs, faeces, and blood were obtained for BFDV and Mycobacterium avium testing with PCR. Birds were euthanized nine weeks after inoculation. All infected budgerigars developed signs typical of mycobacteriosis, but more advanced clinical and pathological changes were visible in the group infected with the pheasant isolate. Only a few cloacal and crop swab samples were positive for Mycobacterium avium subsp. avium despite advanced pathological changes in the internal organs. In the groups infected with mycobacterium isolates the frequency of BFDV-positive samples was higher than in the control group. In the infected groups the frequency of BFDV was substantially higher in the cloacal swabs of birds inoculated with the pheasant isolate than in the peafowl-isolate-infected group. PMID:24738057
McLean, K M; Whiteley, H R
A ca. 10-kilobase (kb) HindIII fragment of plasmid DNA from Bacillus thuringiensis subsp. israelensis was cloned into plasmid pUC9 and transformed into Escherichia coli. Extracts of the recombinant strain contained a 27-kilodalton (kDa) peptide that reacted with antibodies to a 27-kDa peptide isolated from crystals produced by B. thuringiensis subsp. israelensis. Extracts of the recombinant strain were hemolytic and toxic to Aedes aegypti larvae. Full expression of the 27-kDa peptide required the presence of a ca. 0.8-kb region of DNA located 4 kb upstream from the structural gene; the 0.8-kb region could be present in cis or trans relative to the gene and apparently acted post-transcriptionally. Analysis of maxicells showed that the 10-kb insert also coded for peptides of 67, 20, and 16 kDa; data obtained with different subclones suggest that the 20-kDa peptide is encoded in the 0.8-kb DNA region. Images PMID:3546262
Tatay-Dualde, Juan; Prats-van der Ham, Miranda; Paterna, Ana; Sánchez, Antonio; Corrales, Juan Carlos; Contreras, Antonio; Tola, Sebastiana; Gómez-Martin, Ángel
Mycoplasma capricolum subsp. capricolum is one of the causative agents of contagious agalactia (CA). Nevertheless, there is still a lack of information about its antimicrobial susceptibility and genetic characteristics. Therefore, the aim of this work was to study the antimicrobial and genetic variability of different Mycoplasma capricolum subsp. capricolum field isolates. For this purpose, the growth inhibition effect of 18 antimicrobials and a multilocus sequence typing (MLST) scheme based on five housekeeping genes (fusA, glpQ, gyrB, lepA and rpoB) were performed on 32 selected field isolates from Italy and Spain.The results showed a wide range of growth inhibitory effects for almost all the antimicrobials studied. Macrolides presented lower efficacy inhibiting Mcc growth than in previous works performed on other CA-causative mycoplasmas. Erythromycin was not able to inhibit the growth of any of the studied strains, contrary to doxycycline, which inhibited the growth of all of them from low concentrations. On the other hand, the study of the concatenated genes revealed a high genetic variability among the different Mcc isolates. Hence, these genetic variations were greater than the ones reported in prior works on other mycoplasma species. PMID:28346546
Rocha, Liliana O.; Tralamazza, Sabina Moser.; Reis, Gabriela M.; Rabinovitch, Leon; Barbosa, Cynara B.; Corrêa, Benedito
Bacterial antagonists used as biocontrol agents represent part of an integrated management program to reduce pesticides in the environment. Bacillus thuringiensis is considered a good alternative as a biocontrol agent for suppressing plant pathogens such as Fusarium. In this study, we used microscopy, flow cytometry, indirect immunofluorescence, and high performance liquid chromatography to determine the interaction between B. thuringiensis subsp. kurstaki LFB-FIOCRUZ (CCGB) 257 and F. verticillioides MRC 826, an important plant pathogen frequently associated with maize. B. thuringiensis showed a strong in vitro suppressive effect on F. verticillioides growth and inhibited fumonisin production. Flow cytometry analysis was found to be adequate for characterizing the fungal cell oscillations and death during these interactions. Further studies of the antagonistic effect of this isolate against other fungi and in vivo testing are necessary to determine the efficacy of B. thuringiensis subsp. kurstaki in controlling plant pathogens. This is the first report on the use of flow cytometry for quantifying living and apoptotic F. verticillioides cells and the B. thuringiensis Cry 1Ab toxin. PMID:24739804
The quarantine bacterium Clavibacter michiganensis subsp. sepedonicus (Cms) causes bacterial ring rot (BRR) in potato but is difficult to detect, hampering the diagnosis of this disease. ELISA immunoassays have not been widely used to detect Cms because commercially available anti-Cms antibodies detect mainly EPS-producing bacteria and can fail to detect strains that do not produce EPS. In the current study, we developed a new type of polyclonal antibody that specifically detects Clavibacter michiganensis subsp. sepedonicus bacteria irrespective of their EPS level. We first found that the presence of bacterial EPS precluded quantitative measurement of bacteria by currently available immunoenzymatic methods, but that washing Cms cells with acidic and basic buffers to remove EPS before analysis successfully standardized ELISA results. We used a mix of three strains of Cms with diverse EPS levels to generate antigen for production of antibodies recognizing Cms cells with and without an EPS layer (IgG-EPS and IgG-N-EPS, respectively). The resulting IgG-N-EPS recognized almost all Cms strains tested in this work regardless of their mucoidal level. The availability of this new antibody renders immunological diagnostics of Cms more sensitive and reliable, as our newly developed antibodies can be used in many type of immunoassays. This work represents an important step forward in efforts to diagnose and prevent the spread of BRR, and the methods and solutions developed in this work are covered by six Polish, one European and one US patents. PMID:28068400
Reiter, Birgit; Pfeifer, Ulrike; Schwab, Helmut; Sessitsch, Angela
The term endophyte refers to interior colonization of plants by microorganisms that do not have pathogenic effects on their hosts, and various endophytes have been found to play important roles in plant vitality. In this study, cultivation-independent terminal restriction fragment length polymorphism analysis of 16S ribosomal DNA directly amplified from plant tissue DNA was used in combination with molecular characterization of isolates to examine the influence of plant stress, achieved by infection with the blackleg pathogen Erwinia carotovora subsp. atroseptica, on the endophytic population in two different potato varieties. Community analysis clearly demonstrated increased bacterial diversity in infected plants compared to that in control plants. The results also indicated that the pathogen stress had a greater impact on the bacteria population than the plant genotype had. Partial sequencing of the 16S rRNA genes of isolated endophytes revealed a broad phylogenetic spectrum of bacteria, including members of the α, β, and γ subgroups of the Proteobacteria, high- and low-G+C-content gram-positive organisms, and microbes belonging to the Flexibacter-Cytophaga-Bacteroides group. Screening of the isolates for antagonistic activity against E. carotovora subsp. atroseptica revealed that 38% of the endophytes protected tissue culture plants from blackleg disease. PMID:11976096
Begg, Douglas J.; Dhand, Navneet K.; Watt, Bruce; Whittington, Richard J.
The duration of survival of both the S and C strains of Mycobacterium avium subsp. paratuberculosis in feces was quantified in contrasting climatic zones of New South Wales, Australia, and detailed environmental temperature data were collected. Known concentrations of S and C strains in feces placed on soil in polystyrene boxes were exposed to the environment with or without the provision of shade (70%) at Bathurst, Armidale, Condobolin, and Broken Hill, and subsamples taken every 2 weeks were cultured for the presence of M. avium subsp. paratuberculosis. The duration of survival ranged from a minimum of 1 week to a maximum of 16 weeks, and the provision of 70% shade was the most important factor in extending the survival time. The hazard of death for exposed compared to shaded samples was 20 and 9 times higher for the S and C strains, respectively. Site did not affect the survival of the C strain, but for the S strain, the hazard of death was 2.3 times higher at the two arid zone sites (Broken Hill and Condobolin) than at the two temperate zone sites (Bathurst and Armidale). Temperature measurements revealed maximum temperatures exceeding 60°C and large daily temperature ranges at the soil surface, particularly in exposed boxes. PMID:24463974
Moreno Muñoz, José Antonio; Chenoll, Empar; Casinos, Beatriz; Bataller, Esther; Ramón, Daniel; Genovés, Salvador; Montava, Rebeca; Ribes, Juan Manuel; Buesa, Javier; Fàbrega, Joan; Rivero, Montserrat
Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents. In this study, a novel Bifidobacterium longum subsp. infantis strain was isolated from infant feces and selected, based on its capacity to inhibit in vitro rotavirus Wa replication (up to 36.05% infectious foci reduction) and also to protect cells from virus infection (up to 48.50% infectious foci reduction) in both MA-104 and HT-29 cell lines. Furthermore, studies using a BALB/c mouse model have proved that this strain provides preliminary in vivo protection against rotavirus infection. The strain has been deposited in the Spanish Type Culture Collection under the accession number CECT 7210. This novel strain has the main properties required of a probiotic, such as resistance to gastrointestinal juices, biliary salts, NaCl, and low pH, as well as adhesion to intestinal mucus and sensitivity to antibiotics. The food safety status has been confirmed by the absence of undesirable metabolite production and in acute ingestion studies of mice. Overall, these results demonstrate that Bifidobacterium longum subsp. infantis CECT 7210 can be considered a probiotic able to inhibit rotavirus infection. PMID:22003027
Voordouw, G; Strang, J D; Wilson, F R
The genes encoding the periplasmic [Fe] hydrogenase from Desulfovibrio vulgaris subsp. oxamicus Monticello were cloned by exploiting their homology with the hydAB genes from D. vulgaris subsp. vulgaris Hildenborough, in which this enzyme is present as a heterologous dimer of alpha and beta subunits. Nucleotide sequencing showed that the enzyme is encoded by an operon in which the gene for the 46-kilodalton (kDa) alpha subunit precedes that of the 13.5-kDa beta subunit, exactly as in the Hildenborough strain. The pairs of hydA and hydB genes are highly homologous; both alpha subunits (420 amino acid residues) share 79% sequence identity, while the unprocessed beta subunits (124 and 123 amino acid residues, respectively) share 71% sequence identity. In contrast, there appears to be no sequence homology outside these coding regions, with the exception of a possible promoter element, which was found approximately 90 base pairs upstream from the translational start of the hydA gene. The recently discovered hydC gene, which may code for a 65.8-kDa fusion protein (gamma) of the alpha and beta subunits and is present immediately downstream from the hydAB genes in the Hildenborough strain, was found to be absent from the Monticello strain. The implication of this result for the possible function of the hydC gene product in Desulfovibrio species is discussed. Images PMID:2661538
Ashman, Tia-Lynn; Tennessen, Jacob A; Dalton, Rebecca M; Govindarajulu, Rajanikanth; Koski, Matthew H; Liston, Aaron
Gynodioecy, the coexistence of females and hermaphrodites, occurs in 20% of angiosperm families and often enables transitions between hermaphroditism and dioecy. Clarifying mechanisms of sex determination in gynodioecious species can thus illuminate sexual system evolution. Genetic determination of gynodioecy, however, can be complex and is not fully characterized in any wild species. We used targeted sequence capture to genetically map a novel nuclear contributor to male sterility in a self-pollinated hermaphrodite of Fragaria vesca subsp. bracteata from the southern portion of its range. To understand its interaction with another identified locus and possibly additional loci, we performed crosses within and between two populations separated by 2000 km, phenotyped the progeny and sequenced candidate markers at both sex-determining loci. The newly mapped locus contains a high density of pentatricopeptide repeat genes, a class commonly involved in restoration of fertility caused by cytoplasmic male sterility. Examination of all crosses revealed three unlinked epistatically interacting loci that determine sexual phenotype and vary in frequency between populations. Fragaria vesca subsp. bracteata represents the first wild gynodioecious species with genomic evidence of both cytoplasmic and nuclear genes in sex determination. We propose a model for the interactions between these loci and new hypotheses for the evolution of sex determining chromosomes in the subdioecious and dioecious Fragaria.
Villegas, Josefina M; Brown, Lucía; Savoy de Giori, Graciela; Hebert, Elvira M
The cell envelope-associated proteinase (CEP) of Lactobacillus delbrueckii subsp. lactis CRL 581 (PrtL) has an essential role in bacterial growth, contributes to the flavor and texture development of fermented products, and can release bioactive health-beneficial peptides during milk fermentation. The genome of L. delbrueckii subsp. lactis CRL 581 possesses only one gene that encodes PrtL, which consists of 1924 amino acids and is a multidomain protein anchored to the cell via its W domain. PrtL was extracted from the cell under high ionic strength conditions using NaCl, suggesting an electrostatic interaction between the proteinase and the cell envelope. The released PrtL was purified and biochemically characterized; its activity was maximal at temperatures between 37 and 40 °C and at pH between 7 and 8. Under optimal conditions, PrtL exhibited higher affinity for succinyl-alanyl-alanyl-prolyl-phenylalanine-p-nitroanilide than for succinyl-alanyl-glutamyl-prolyl-phenylalanine-p-nitroanilide, while methoxy-succinyl-arginyl-prolyl-tyrosyl-p-nitroanilide was not degraded. A similar α- and β-casein degradation pattern was observed with the purified and the cell envelope-bound proteinase. Finally, on the basis of its specificity towards caseins and the unique combination of amino acids at residues thought to be involved in substrate specificity, PrtL can be classified as a representative of a new group of CEP.
Raveendar, Sebastin; Lee, Gi-An; Jeon, Young-Ah; Lee, Yun Jeong; Lee, Jung-Ro; Cho, Gyu-Taek; Cho, Joon-Hyeong; Park, Jong-Hyun; Ma, Kyung-Ho; Chung, Jong-Wook
The temperate and herbaceous genus Vicia L. is a member of the legume tribe Fabeae of the subfamily Papilionoideae. The genus Vicia comprises 166 annual or perennial species distributed mainly in Europe, Asia, and North America, but also extending to the temperate regions of South America and tropical Africa. The use of simple sequence repeat (SSR) markers for Vicia species has not been investigated as extensively as for other crop species. In this study, we assessed the potential for cross-species amplification of cDNA microsatellite markers developed from common vetch (Vicia sativa subsp. sativa). For cross-species amplification of the SSRs, amplification was carried out with genomic DNA isolated from two to eight accessions of 22 different Vicia species. For individual species or subspecies, the transferability rates ranged from 33% for V. ervilia to 82% for V. sativa subsp. nigra with an average rate of 52.0%. Because the rate of successful SSR marker amplification generally correlates with genetic distance, these SSR markers are potentially useful for analyzing genetic relationships between or within Vicia species.
Ceylan, Ozgur; Sahin, Mehtap Donmez; Akdamar, Gultekin
In this study, anti-quorum sensing, and antioxidant activities, and chemical composition of Acer monspessulanum subsp. monspessulanum extracts were evaluated. Determination of the antioxidant activity was revealed by DPPH radical scavenging activity, the total phenolic content assay, and the β-carotene/linoleic acid assay. The detection of phenolic compounds was determined using RP-HPLC. Anti-quorum sensing activity and violacein inhibition activity were determined using Chromobacterium violaceum CV026 and C. violaceum ATCC 112 472, respectively. The determination of anti-swarming activity was carried out with Pseudomonas aeruginosa PA01. In DPPH and total phenolic content assays, the water extract exhibited good antioxidant activity. In the β-carotene-linoleic acid assay, ethyl acetate and ethanol extracts exhibited good lipid peroxidation inhibition activity, demonstrating 96.95 ± 0.03 % and 95.35 ± 0.00 % at 2.5 mg/mL concentrations, respectively. The predominant phenolic compounds of the extracts were determined as rutin, naringin, catechin hydrate, quercetin, and protocatechuic acid. Ethyl acetate and ethanol extracts were found to contain a high level of violacein inhibition and anti-quorum sensing activity. The ethanol extract also showed weak anti-swarming activity. In this first study that used Acer monspessulanum subsp. monspessulanum extracts, it was revealed that the water extract has antioxidant activity and the ethanol and ethyl acetate extracts have anti-quorum sensing activity depending on the phenolic compounds that it contained.
Hugo, Ayelén A; Rolny, Ivanna S; Romanin, David; Pérez, Pablo F
Citrobacter rodentium is a specific murine enteropathogen which causes diarrheal disease characterized by colonic hyperplasia and intestinal inflammation. Recruitment of neutrophils and macrophages constitute a key step to control the infection. Since modulation of the activity of professional phagocytic cells could contribute to improve host´s defences against C. rodentium, we investigated the effect of Lactobacillus delbrueckii subsp. lactis (strain CIDCA 133) on the interaction between murine macrophages (RAW 264.7) and C. rodentium. Phagocytosis, surface molecules and inducible nitric oxide synthase (iNOs) expression were determined by flow cytometry. Reactive oxygen species (ROS) were assessed by fluorescence microscopy. The presence of lactobacilli increased phagocytosis of C. rodentium whereas C. rodentium had no effect on lactobacilli internalization. Survival of internalized C. rodentium diminished when strain CIDCA 133 was present. CD-86, MHCII, iNOs expression and nitrite production were increased when C. rodentium and lactobacilli were present even though strain CIDCA 133 alone had no effect. Strain CIDCA 133 led to a strong induction of ROS activity which was not modified by C. rodentium. Lactobacillus delbrueckii subsp. lactis (strain CIDCA 133) is able to increase the activation of murine macrophages infected with C. rodentium. The sole presence of lactobacilli is enough to modify some stimulation markers (e.g. ROS induction) whereas other markers require the presence of both bacteria; thus, indicating a synergistic effect.
Johansen, Tone Bjordal; Agdestein, Angelika; Lium, Bjørn; Jørgensen, Anne; Djønne, Berit
Mycobacterium avium subsp. hominissuis is an environmental bacterium causing opportunistic infections in swine, resulting in economic losses. Additionally, the zoonotic aspect of such infections is of concern. In the southeastern region of Norway in 2009 and 2010, an increase in condemnation of pig carcasses with tuberculous lesions was seen at the meat inspection. The use of peat as bedding in the herds was suspected to be a common factor, and a project examining pigs and environmental samples from the herds was initiated. Lesions detected at meat inspection in pigs originating from 15 herds were sampled. Environmental samples including peat from six of the herds and from three peat production facilities were additionally collected. Samples were analysed by culture and isolates genotyped by MLVA analysis. Mycobacterium avium subsp. hominissuis was detected in 35 out of 46 pigs, in 16 out of 20 samples of peat, and in one sample of sawdust. MLVA analysis demonstrated identical isolates from peat and pigs within the same farms. Polyclonal infection was demonstrated by analysis of multiple isolates from the same pig. To conclude, the increase in condemnation of porcine carcasses at slaughter due to mycobacteriosis seemed to be related to untreated peat used as bedding.
Altmann, Friedrich; Kosma, Paul; O'Callaghan, Amy; Leahy, Sinead; Bottacini, Francesca; Molloy, Evelyn; Plattner, Stephan; Schiavi, Elisa; Gleinser, Marita; Groeger, David; Grant, Ray; Rodriguez Perez, Noelia; Healy, Selena; Svehla, Elisabeth; Windwarder, Markus; Hofinger, Andreas; O'Connell Motherway, Mary; Akdis, Cezmi A; Xu, Jun; Roper, Jennifer; van Sinderen, Douwe; O'Mahony, Liam
The Bifibobacterium longum subsp. longum 35624™ strain (formerly named Bifidobacterium longum subsp. infantis) is a well described probiotic with clinical efficacy in Irritable Bowel Syndrome clinical trials and induces immunoregulatory effects in mice and in humans. This paper presents (a) the genome sequence of the organism allowing the assignment to its correct subspeciation longum; (b) a comparative genome assessment with other B. longum strains and (c) the molecular structure of the 35624 exopolysaccharide (EPS624). Comparative genome analysis of the 35624 strain with other B. longum strains determined that the sub-speciation of the strain is longum and revealed the presence of a 35624-specific gene cluster, predicted to encode the biosynthetic machinery for EPS624. Following isolation and acid treatment of the EPS, its chemical structure was determined using gas and liquid chromatography for sugar constituent and linkage analysis, electrospray and matrix assisted laser desorption ionization mass spectrometry for sequencing and NMR. The EPS consists of a branched hexasaccharide repeating unit containing two galactose and two glucose moieties, galacturonic acid and the unusual sugar 6-deoxy-L-talose. These data demonstrate that the B. longum 35624 strain has specific genetic features, one of which leads to the generation of a characteristic exopolysaccharide.
Altmann, Friedrich; Kosma, Paul; O’Callaghan, Amy; Leahy, Sinead; Bottacini, Francesca; Molloy, Evelyn; Plattner, Stephan; Schiavi, Elisa; Gleinser, Marita; Groeger, David; Grant, Ray; Rodriguez Perez, Noelia; Healy, Selena; Svehla, Elisabeth; Windwarder, Markus; Hofinger, Andreas; O’Connell Motherway, Mary; Akdis, Cezmi A.; Xu, Jun; Roper, Jennifer; van Sinderen, Douwe; O’Mahony, Liam
The Bifibobacterium longum subsp. longum 35624™ strain (formerly named Bifidobacterium longum subsp. infantis) is a well described probiotic with clinical efficacy in Irritable Bowel Syndrome clinical trials and induces immunoregulatory effects in mice and in humans. This paper presents (a) the genome sequence of the organism allowing the assignment to its correct subspeciation longum; (b) a comparative genome assessment with other B. longum strains and (c) the molecular structure of the 35624 exopolysaccharide (EPS624). Comparative genome analysis of the 35624 strain with other B. longum strains determined that the sub-speciation of the strain is longum and revealed the presence of a 35624-specific gene cluster, predicted to encode the biosynthetic machinery for EPS624. Following isolation and acid treatment of the EPS, its chemical structure was determined using gas and liquid chromatography for sugar constituent and linkage analysis, electrospray and matrix assisted laser desorption ionization mass spectrometry for sequencing and NMR. The EPS consists of a branched hexasaccharide repeating unit containing two galactose and two glucose moieties, galacturonic acid and the unusual sugar 6-deoxy-L-talose. These data demonstrate that the B. longum 35624 strain has specific genetic features, one of which leads to the generation of a characteristic exopolysaccharide. PMID:27656878
Avila, R; Pinheiro, M; Sazima, M
Inga species are characterised by generalist or mixed pollination system. However, this feature does not enhance reproductive rates in species with very low fruit set under natural conditions. Some ecological and genetic factors are associated with this feature, and to test the effect of massive visits on pollination success in Inga subnuda subsp. luschnathiana, we studied the efficacy of polyads deposited on stigmas of flowers isolated from visitors and polyads exposed to visitors. The proportion of polyads fixed in stigmas decreased after exposure to visitors (24 h) in comparison to stigmas isolated from visitors (hummingbirds, bees, wasps, hawkmoths and bats), and fruit set was very low. Furthermore, nectar production, sugar composition and other floral biology traits were evaluated. Increased nectar production, sugar availability and sucrose dominance during the night indicates adaptation to nocturnal visitors and supports their role as main pollinators; although the brush-flower morphology, time of anthesis, nectar dynamics and chemical composition also allow daytime visitors. Thus the species is an important resource for a diverse group of floral visitors. We conclude that excess visits (diurnal and nocturnal) are responsible for the decrease in fixed polyads in stigmas of I. subnuda subsp. luschnathiana flowers, thus contributing, with others factors, to its low fruit set. Therefore, the generalist pollination system does not result in reproductive advantages because the low fruit set in natural conditions could be the result of a negative effect of visitors/pollinators.
Wegmann, Udo; O'Connell-Motherway, Mary; Zomer, Aldert; Buist, Girbe; Shearman, Claire; Canchaya, Carlos; Ventura, Marco; Goesmann, Alexander; Gasson, Michael J.; Kuipers, Oscar P.; van Sinderen, Douwe; Kok, Jan
Lactococcus lactis is of great importance for the nutrition of hundreds of millions of people worldwide. This paper describes the genome sequence of Lactococcus lactis subsp. cremoris MG1363, the lactococcal strain most intensively studied throughout the world. The 2,529,478-bp genome contains 81 pseudogenes and encodes 2,436 proteins. Of the 530 unique proteins, 47 belong to the COG (clusters of orthologous groups) functional category “carbohydrate metabolism and transport,” by far the largest category of novel proteins in comparison with L. lactis subsp. lactis IL1403. Nearly one-fifth of the 71 insertion elements are concentrated in a specific 56-kb region. This integration hot-spot region carries genes that are typically associated with lactococcal plasmids and a repeat sequence specifically found on plasmids and in the “lateral gene transfer hot spot” in the genome of Streptococcus thermophilus. Although the parent of L. lactis MG1363 was used to demonstrate lysogeny in Lactococcus, L. lactis MG1363 carries four remnant/satellite phages and two apparently complete prophages. The availability of the L. lactis MG1363 genome sequence will reinforce its status as the prototype among lactic acid bacteria through facilitation of further applied and fundamental research. PMID:17307855
Kimmel, Stacy A.; Roberts, Robert F.; Ziegler, Gregory R.
The optimal fermentation temperature, pH, and Bacto-casitone (Difco Laboratories, Detroit, Mich.) concentration for production of exopolysaccharide by Lactobacillus delbrueckii subsp. bulgaricus RR in a semidefined medium were determined by using response surface methods. The design consisted of 20 experiments, 15 unique combinations, and five replications. All fermentations were conducted in a fermentor with a 2.5-liter working volume and were terminated when 90% of the glucose in the medium had been consumed. The population of L. delbrueckii subsp. bulgaricus RR and exopolysaccharide content were measured at the end of each fermentation. The optimum temperature, pH, and Bacto-casitone concentration for exopolysaccharide production were 38°C, 5, and 30 g/liter, respectively, with a predicted yield of 295 mg of exopolysaccharide/liter. The actual yield under these conditions was 354 mg of exopolysaccharide/liter, which was within the 95% confidence interval (217 to 374 mg of exopolysaccharide/liter). An additional experiment conducted under optimum conditions showed that exopolysaccharide production was growth associated, with a specific production at the endpoint of 101.4 mg/g of dry cells. Finally, to obtain material for further characterization, a 100-liter fermentation was conducted under optimum conditions. Twenty-nine grams of exopolysaccharide was isolated from centrifuged, ultrafiltered fermentation broth by ethanol precipitation. PMID:9464404
Li, Zhen-Hua; Tang, Zhen-Xing; Fang, Xiu-Juan; Zhang, Zhi-Liang; Shi, Lu-E
In this paper, the physical and chemical characteristics, biological structure and function of a non-specific nuclease from Yersinia enterocolitica subsp. palearctica (Y. NSN) found in our group were studied using multiple bioinformatics approaches. The results showed that Y. NSN had 283 amino acids, a weight of 30,692.5 ku and a certain hydrophilic property. Y. NSN had a signal peptide, no transmembrane domains and disulphide bonds. Cleavage site in Y. NSN was between pos. 23 and 24. The prediction result of the secondary structure showed Y. NSN was a coil structure-based protein. The ratio of α-helix, β-folded and random coil were 18.73%, 16.96% and 64.31%, respectively. Active sites were pos. 124, 125, 127, 157, 165 and 169. Mg(2+) binding site was pos. 157. Substrate binding sites were pos. 124, 125 and 169. The analysis of multisequencing alignment and phylogenetic tree indicated that Y. NSN shared high similarity with the nuclease from Y. enterocolitica subsp. enterocolitica 8081. The enzyme activity results showed that Y. NSN was a nuclease with good thermostability.
Zito, P; Sajeva, M; Bruno, M; Rosselli, S; Maggio, A; Senatore, F
The essential oil of roots, branches, leaves, flowers and fruits of Periploca laevigata Aiton subsp. angustifolia (Apocynaceae) from Lampedusa Island has been obtained by hydrodistillation and its composition analysed. The analyses allowed the identification and quantification of 86 volatile compounds. Branches showed the higher diversity with 57 compounds followed by fruits with 33, roots with 23, flowers with 16 and leaves with six compounds, respectively. In the matrices examined three constituents, heneicosane, docosane and tricosane are in common, although with different percentages. At least the most abundant compounds found in the matrices have been reported to have several biological activities. 2-Hydroxy-4-methoxybenzaldehyde identified in the roots as the most abundant component (70.7%) and present with 8.3% in the branches is a potent tyrosinase inhibitor present in several African medicinal plants, and thus being used as an ingredient in cosmetic and other medicinal products, primarily in relation to hyperpigmentation. Among the compounds identified, several play a role as semiochemicals for many animals, and 28 allomones, 43 pheromones, 21 kairomones have been identified. P. laevigata subsp. angustifolia in Lampedusa Island is host to a community of visitors, and the possible ecological role of the volatiles found is briefly discussed.
Muñoz, José Antonio Moreno; Chenoll, Empar; Casinos, Beatriz; Bataller, Esther; Ramón, Daniel; Genovés, Salvador; Montava, Rebeca; Ribes, Juan Manuel; Buesa, Javier; Fàbrega, Joan; Rivero, Montserrat
Rotavirus is the leading cause of severe acute gastroenteritis among children worldwide. It is well known that breast-feeding and vaccination afford infants protection. Since breast-feeding has drastically decreased in developed countries, efforts have been focused on the potential use of probiotics as preventive agents. In this study, a novel Bifidobacterium longum subsp. infantis strain was isolated from infant feces and selected, based on its capacity to inhibit in vitro rotavirus Wa replication (up to 36.05% infectious foci reduction) and also to protect cells from virus infection (up to 48.50% infectious foci reduction) in both MA-104 and HT-29 cell lines. Furthermore, studies using a BALB/c mouse model have proved that this strain provides preliminary in vivo protection against rotavirus infection. The strain has been deposited in the Spanish Type Culture Collection under the accession number CECT 7210. This novel strain has the main properties required of a probiotic, such as resistance to gastrointestinal juices, biliary salts, NaCl, and low pH, as well as adhesion to intestinal mucus and sensitivity to antibiotics. The food safety status has been confirmed by the absence of undesirable metabolite production and in acute ingestion studies of mice. Overall, these results demonstrate that Bifidobacterium longum subsp. infantis CECT 7210 can be considered a probiotic able to inhibit rotavirus infection.
Moravkova, M; Babak, V; Kralova, A; Pavlik, I; Slana, I
The aim of this study was to monitor the persistence of Mycobacterium avium subsp. paratuberculosis in environmental samples taken from a Holstein farm with a long history of clinical paratuberculosis. A herd of 606 head was eradicated, and mechanical cleaning and disinfection with chloramine B with ammonium (4%) was carried out on the farm; in the surrounding areas (on the field and field midden) lime was applied. Environmental samples were collected before and over a period of 24 months after destocking. Only one sample out of 48 (2%) examined on the farm (originating from a waste pit and collected before destocking) was positive for M. avium subsp. paratuberculosis by cultivation on solid medium (Herrold's egg yolk medium). The results using real-time quantitative PCR (qPCR) showed that a total of 81% of environmental samples with an average mean M. avium subsp. paratuberculosis cell number of 3.09 × 10(3) were positive for M. avium subsp. paratuberculosis before destocking compared to 43% with an average mean M. avium subsp. paratuberculosis cell number of 5.86 × 10(2) after 24 months. M. avium subsp. paratuberculosis-positive samples were detected in the cattle barn as well as in the calf barn and surrounding areas. M. avium subsp. paratuberculosis was detected from different matrices: floor and instrument scrapings, sediment, or scraping from watering troughs, waste pits, and cobwebs. M. avium subsp. paratuberculosis DNA was also detected in soil and plants collected on the field midden and the field 24 months after destocking. Although the proportion of positive samples decreased from 64% to 23% over time, the numbers of M. avium subsp. paratuberculosis cells were comparable.
Isolation of Bartonella henselae and Two New Bartonella Subspecies, Bartonella koehlerae Subspecies boulouisii subsp. nov. and Bartonella koehlerae Subspecies bothieri subsp. nov. from Free-Ranging Californian Mountain Lions and Bobcats
Chomel, Bruno B.; Molia, Sophie; Kasten, Rickie W.; Borgo, Gina M.; Stuckey, Matthew J.; Maruyama, Soichi; Chang, Chao-chin; Haddad, Nadia; Koehler, Jane E.
Domestic cats are the natural reservoir of Bartonella henselae, B. clarridgeiae and B. koehlerae. To determine the role of wild felids in the epidemiology of Bartonella infections, blood was collected from 14 free-ranging California mountain lions (Puma concolor) and 19 bobcats (Lynx rufus). Bartonella spp. were isolated from four (29%) mountain lions and seven (37%) bobcats. These isolates were characterized using growth characteristics, biochemical reactions, molecular techniques, including PCR-RFLP of selected genes or interspacer region, pulsed-field gel electrophoresis (PFGE), partial sequencing of several genes, and DNA-DNA hybridization. Two isolates were identical to B. henselae genotype II. All other isolates were distinguished from B. henselae and B. koehlerae by PCR-RFLP of the gltA gene using endonucleases HhaI, TaqI and AciI, with the latter two discriminating between the mountain lion and the bobcat isolates. These two novel isolates displayed specific PFGE profiles distinct from B. henselae, B. koehlerae and B. clarridgeiae. Sequences of amplified gene fragments from the three mountain lion and six bobcat isolates were closely related to, but distinct from, B. henselae and B. koehlerae. Finally, DNA-DNA hybridization studies demonstrated that the mountain lion and bobcat strains are most closely related to B. koehlerae. We propose naming the mountain lion isolates B. koehlerae subsp. boulouisii subsp. nov. (type strain: L-42-94), and the bobcat isolates B. koehlerae subsp. bothieri subsp. nov. (type strain: L-17-96), and to emend B. koehlerae as B. koehlerae subsp. koehlerae. The mode of transmission and the zoonotic potential of these new Bartonella subspecies remain to be determined. PMID:26981874
Isolation of Bartonella henselae and Two New Bartonella Subspecies, Bartonellakoehlerae Subspecies boulouisii subsp. nov. and Bartonella koehlerae Subspecies bothieri subsp. nov. from Free-Ranging Californian Mountain Lions and Bobcats.
Chomel, Bruno B; Molia, Sophie; Kasten, Rickie W; Borgo, Gina M; Stuckey, Matthew J; Maruyama, Soichi; Chang, Chao-Chin; Haddad, Nadia; Koehler, Jane E
Domestic cats are the natural reservoir of Bartonella henselae, B. clarridgeiae and B. koehlerae. To determine the role of wild felids in the epidemiology of Bartonella infections, blood was collected from 14 free-ranging California mountain lions (Puma concolor) and 19 bobcats (Lynx rufus). Bartonella spp. were isolated from four (29%) mountain lions and seven (37%) bobcats. These isolates were characterized using growth characteristics, biochemical reactions, molecular techniques, including PCR-RFLP of selected genes or interspacer region, pulsed-field gel electrophoresis (PFGE), partial sequencing of several genes, and DNA-DNA hybridization. Two isolates were identical to B. henselae genotype II. All other isolates were distinguished from B. henselae and B. koehlerae by PCR-RFLP of the gltA gene using endonucleases HhaI, TaqI and AciI, with the latter two discriminating between the mountain lion and the bobcat isolates. These two novel isolates displayed specific PFGE profiles distinct from B. henselae, B. koehlerae and B. clarridgeiae. Sequences of amplified gene fragments from the three mountain lion and six bobcat isolates were closely related to, but distinct from, B. henselae and B. koehlerae. Finally, DNA-DNA hybridization studies demonstrated that the mountain lion and bobcat strains are most closely related to B. koehlerae. We propose naming the mountain lion isolates B. koehlerae subsp. boulouisii subsp. nov. (type strain: L-42-94), and the bobcat isolates B. koehlerae subsp. bothieri subsp. nov. (type strain: L-17-96), and to emend B. koehlerae as B. koehlerae subsp. koehlerae. The mode of transmission and the zoonotic potential of these new Bartonella subspecies remain to be determined.
Wang, Hua; Chen, Yi; Ayers, Sherry; Melka, David; Laasri, Anna; Payne, Justin S; Zheng, Jie; Son, Insook; Timme, Ruth; Kastanis, George; Hammack, Thomas S; Strain, Errol; Allard, Marc W; Evans, Peter S; Brown, Eric W
We report the genome sequence of Salmonella enterica subsp. enterica serovar Give (CFSAN012622), isolated from imported chili powder in 2014. This genome contains genes previously reported to be specific only to S. enterica serovar Enteritidis. This strain shows a unique pulsed-field gel electrophoresis (PFGE) pattern clustering with serovar Enteritidis (JEG X01.0005).
Bacterial fruit blotch (Acidovorax avenae subsp. citrulli [Schaad et al.] Willems et al.) continues to occur almost every year and has the potential to cause a disaster for the watermelon industry. In this study, Crimson Sweet watermelon was crossed with PI482279 and PI494817, two Citrullus lanatus...
Kim, J H; Choresca, C H; Shin, S P; Han, J E; Jun, J W; Park, S C
The potential control efficacy of Aeromonas phage PAS-1 was evaluated against Aeromonas salmonicida subsp. salmonicida infection in rainbow trout (Oncorhynchus mykiss) model in this study. The phage was co-cultured with the virulent A. salmonicida subsp. salmonicida strain AS05 that possesses the type III secretion system (TTSS) ascV gene, and efficient bacteriolytic activity was observed against the bacteria. The administration of PAS-1 in rainbow trout demonstrated that the phage was cleared from the fish within 200 h post-administration, and a temporal neutralizing activity against the phage was detected in the sera of phage-administrated fish. The administration of PAS-1 (multiplicity of infection: 10 000) in A. salmonicida subsp. salmonicida infected rainbow trout model showed notable protective effects, with increased survival rates and mean times to death. These results demonstrated that Aeromonas phage PAS-1 could be considered as an alternative biological control agent against A. salmonicida subsp. salmonicida infections in rainbow trout culture.
Genetically-engineered glyphosate-resistant alfalfa (Medicago sativa subsp. sativa) was commercialized in 2011. The potential risk of transgene dispersal into the environment is not clearly understood for alfalfa, a perennial crop that is cross-pollinated by insects. We gathered data on feral and tr...
Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János
ABSTRACT Four strains of Salmonella enterica subsp. enterica serovar Infantis isolated from humans (1980 to 1982) and broiler chickens (2016) have been sequenced. They represent the early and recent peak incidences of this serovar in Hungary. Genome sequences of these isolates provide comparative data on the evolution and rise of an endemic S. Infantis clone in Hungary. PMID:28254986
Huynh, Steven; Gorski, Lisa; Cooper, Kerry K.; Miller, William G.
Salmonella enterica subsp. enterica serovar Thompson strains RM1984 (CADPH-99A2334) and RM1986 (CADPH-99A2345) are associated with a 1999 outbreak in contaminated cilantro. We report here the complete genome sequences and annotation of these two S. Thompson strains. These genomes are distinct and provide additional data for our understanding of S. enterica. PMID:26586897
Amachawadi, Raghavendra G.; Thomas, Milton
The genome sequencing of 13 Salmonella enterica subsp. enterica serovar Lubbock strains isolated from liver abscesses of feedlot cattle is reported here. The availability of these genomes will help to further understand the etiologic role of Salmonella strains in liver abscesses of cattle and will serve as references in microbial trace-back studies to improve food safety. PMID:27151794
Poultry products serve as the main source of Campylobacter jejuni subsp. jejuni (Cjj) infections in humans. Cjj infections are a leading cause of foodborne gastroenteritis and are a prevalent antecedent to Guillain-Barré syndrome (GBS). This study describes the genome of Cjj HS:19 strain RM1285 isol...
Mycobacterium avium subsp. paratuberculosis (MAP) is primarily shed into the feces but it has also been isolated from the milk and colostrum of cows. Because of this, there exists concern about transfer of the organism from dam to calf and about the prevalence of MAP in the milk supply. The prevalen...
Two decontamination chemicals, hexadecylpyridinium choride (HPC) and N-acetyl-L-cysteine-sodium hydroxide (NALC-NaOH), were compared for their efficacy of reducing the growth of non-specific microorganisms in milk while minimally affecting the recovery of Mycobacterium avium subsp. paratuberculosis ...
The primary mode of transmission of Mycobacterium avium subsp. paratuberculosis (MAP) is fecal-oral. However, MAP is also shed into the milk and colostrum of infected cows. The objective of this study was to identify if an association exists between stage of MAP infection and days in lactation with ...
Rivas, Amable J.; Balado, Miguel; Fuentes-Monteverde, Juan Carlos; Rodríguez, Jaime; Jiménez, Carlos; Lemos, Manuel L.; Waldor, Matthew K.
The fish pathogen Photobacterium damselae subsp. piscicida produces the siderophore piscibactin. A gene cluster that resembles the Yersinia high-pathogenicity island (HPI) encodes piscibactin biosynthesis. Here, we report that this HPI-like cluster is part of a hitherto-uncharacterized 68-kb plasmid dubbed pPHDP70. This plasmid lacks homologs of genes that mediate conjugation, but we found that it could be transferred at low frequencies from P. damselae subsp. piscicida to a mollusk pathogenic Vibrio alginolyticus strain and to other Gram-negative bacteria, likely dependent on the conjugative functions of the coresident plasmid pPHDP60. Following its conjugative transfer, pPHDP70 restored the capacity of a vibrioferrin mutant of V. alginolyticus to grow under low-iron conditions, and piscibactin became detectable in its supernatant. Thus, pPHDP70 appears to harbor all the genes required for piscibactin biosynthesis and transport. P. damselae subsp. piscicida strains cured of pPHDP70 no longer produced piscibactin, had impaired growth under iron-limited conditions, and exhibited markedly decreased virulence in fish. Collectively, our findings highlight the importance of pPHDP70, with its capacity for piscibactin-mediated iron acquisition, in the virulence of P. damselae subsp. piscicida. Horizontal transmission of this plasmid-borne piscibactin synthesis gene cluster in the marine environment may facilitate the emergence of new pathogens. PMID:26092457
Messelhäusser, U; Kämpf, P; Hörmansdorfer, S; Wagner, B; Schalch, B; Busch, U; Höller, C; Wallner, P; Barth, G; Rampp, A
A combined molecular and cultural method for the detection of the Mycobacterium tuberculosis complex (MTBC) and Mycobacterium avium subsp. paratuberculosis was developed and tested with artificially contaminated milk and dairy products. Results indicate that the method can be used for a reliable detection as a basis for first risk assessments.
Yan, Yue; Zhao, Chuan-Wu; Zhang, Yi-Zheng; Zhang, Zhi-He; Pan, Guang-Lin; Liu, Wen-Wang; Ma, Qing-Yi; Hou, Rong
Enterobacter cloacae, a common pathogenic bacterium, is a Gram-negative bacillus. We analyzed the draft genome of Enterobacter cloacae subsp. cloacae strain 08XA1 from the feces of a giant panda in China. Genes encoding a β-lactamase and efflux pumps, as well as other factors, have been found in the genome. PMID:23209197
Streptococcus phocae subsp. phocae is a pathogen that affects different pinniped and mammalian species. This announcement reports the genome sequence of the type strain ATCC 51973 isolated in Norway from clinical specimens of harbor seal (Phoca vitulina), revealing interesting genes related to possible virulence factors. PMID:26586875
Xylella fastidiosa is a member of the gamma proteobacteria. It is fastidious, insect-vectored and xylem-limited and causes a variety of diseases, some severe, on a wide range of economically important perennial crops, including grape and citrus. Xylella fastidiosa subsp pauca causes citrus variegat...
The objective of this study was to observe early markers of cell-mediated immunity in naïve calves infected with Mycobacterium avium subsp. paratuberculosis (MAP) and how expression of these markers evolved over the 12-month period of infection. Methods of experimental infection included: Control (n...
Ibarra Caballero, Jorge; Zerillo, Marcelo M.; Snelling, Jacob; Cranshaw, Whitney; Boucher, Christina
Two bacteria identified as Lonsdalea quercina subsp. quercina were isolated from oak trees showing symptoms of drippy blight. Here, we present their draft genome assemblies, as well as that of the type strain of this species. To our knowledge, these are the first published genome sequences of this subspecies of Lonsdalea quercina. PMID:24926062
Mycobacterium avium subsp paratuberculosis (MAP) causes Johne’s disease (JD) in ruminants. Proteomic studies have shown that MAP expresses certain proteins when exposed to in vitro physiological stress conditions similar to the conditions experienced within a host during natural infection. Such prot...
Mycobacterium avium subsp. paratuberculosis (MAP) is the etiologic agent of Johne’s disease in ruminants and it has been implicated as a cause of Crohn’s disease in humans. The generation of comprehensive random mutant banks by transposon mutagenesis is a fundamental wide genomic technology utilized...
Infection of the host with Mycobacterium avium subsp. paratuberculosis (MAP) results in a chronic and progressive enteritis that traverses both subclinical and clinical stages. The mechanism(s) for the shift from asymptomatic subclinical disease state to advanced clinical disease are not fully under...
Paratuberculosis is a chronic intestinal disease of ruminant animals caused by Mycobacterium avium subsp. paratuberculosis (MAP). A hallmark of paratuberculosis is a transition from a cell-mediated Th1 type response to a humoral Th2 response with the progression of disease from a subclinical to clin...
Paratuberculosis is a chronic intestinal disease of ruminant animals caused by Mycobacterium avium subsp. paratuberculosis (MAP). A hallmark of paratuberculosis is a transition from a cell-mediated Th1 type response to a humoral Th2 response with the progression of disease from a subclinical to clin...
Hossain, Mohammad J.; Ran, Chao; Liu, Ke; Ryu, Choong-Min; Rasmussen-Ivey, Cody R.; Williams, Malachi A.; Hassan, Mohammad K.; Choi, Soo-Keun; Jeong, Haeyoung; Newman, Molli; Kloepper, Joseph W.; Liles, Mark R.
To understand the growth-promoting and disease-inhibiting activities of plant growth-promoting rhizobacteria (PGPR) strains, the genomes of 12 Bacillus subtilis group strains with PGPR activity were sequenced and analyzed. These B. subtilis strains exhibited high genomic diversity, whereas the genomes of B. amyloliquefaciens strains (a member of the B. subtilis group) are highly conserved. A pairwise BLASTp matrix revealed that gene family similarity among Bacillus genomes ranges from 32 to 90%, with 2839 genes within the core genome of B. amyloliquefaciens subsp. plantarum. Comparative genomic analyses of B. amyloliquefaciens strains identified genes that are linked with biological control and colonization of roots and/or leaves, including 73 genes uniquely associated with subsp. plantarum strains that have predicted functions related to signaling, transportation, secondary metabolite production, and carbon source utilization. Although B. amyloliquefaciens subsp. plantarum strains contain gene clusters that encode many different secondary metabolites, only polyketide biosynthetic clusters that encode difficidin and macrolactin are conserved within this subspecies. To evaluate their role in plant pathogen biocontrol, genes involved in secondary metabolite biosynthesis were deleted in a B. amyloliquefaciens subsp. plantarum strain, revealing that difficidin expression is critical in reducing the severity of disease, caused by Xanthomonas axonopodis pv. vesicatoria in tomato plants. This study defines genomic features of PGPR strains and links them with biocontrol activity and with host colonization. PMID:26347755
Velly, H.; Abraham, A.-L.; Loux, V.; Delacroix-Buchet, A.; Fonseca, F.; Bouix, M.
Lactococcus lactis is a lactic acid bacterium used in the production of many fermented foods, such as dairy products. Here, we report the genome sequence of L. lactis subsp. lactis TOMSC161, isolated from nonscalded curd pressed cheese. This genome sequence provides information in relation to dairy environment adaptation. PMID:25377704
El Kafsi, Hela; Binesse, Johan; Loux, Valentin; Buratti, Julien; Boudebbouze, Samira; Dervyn, Rozenn; Hammani, Amal; Maguin, Emmanuelle
Lactobacillus delbrueckii subsp. lactis CNRZ327 is a dairy bacterium with anti-inflammatory properties both in vitro and in vivo. Here, we report the genome sequence of this bacterium, which appears to contain no less than 215 insertion sequence (IS) elements, an exceptionally high number regarding the small genome size of the strain. PMID:25035318
Desfossés-Foucault, Émilie; LaPointe, Gisèle; Roy, Denis
The starter cultures (Lactococcus sp.) and non-starter lactic acid bacteria (mostly Lactobacillus spp.) are essential to flavor development of Cheddar cheese. The aim of this study was to elucidate the transcriptional interaction between Lactococcus lactis subsp. cremoris SK11 and Lactobacillus paracasei ATCC 334 in mixed cultures during simulated Cheddar cheese manufacture (Pearce activity test) and ripening (slurry). Reverse transcription quantitative PCR (RT-qPCR) was used to quantify the expression of 34 genes common to both bacteria and for eight genes specific to either L. lactis subsp. cremoris SK11 or L. paracasei ATCC 334. The multifactorial analysis (MFA) performed on fold change results for each gene revealed that the genes linked to stress, protein and peptide degradation as well as carbohydrate metabolism of L. paracasei ATCC 334 were especially overexpressed in mixed culture with L. lactis subsp. cremoris SK11 during the ripening simulation. For L. lactis subsp. cremoris SK11, genes coding for amino acid metabolism were more expressed during the cheese manufacture simulation, especially in single culture. These results show how complementary functions of starter and NSLAB contribute to activities useful for flavor development.
Meletzus, D; Eichenlaub, R
We constructed a cloning vector for use in the plant pathogenic bacterium Clavibacter michiganense subsp. michiganense. The vector pDM100 consists of a 3.2-kb restriction fragment of the Clavibacter plasmid pCM1 joined to a pBR325 derivative carrying the neomycin phosphotransferase of transposon Tn5 and the gentamicin acetyltransferase of Tn1696. Both antibiotic resistance genes are efficiently expressed in C. michiganense subsp. michiganense. Although polyethylene glycol-mediated transfection of spheroplasts with the DNA of the C. michiganense subsp. michiganense-specific bacteriophage CMP1 yielded about 3 x 10(3) transfectants per microgram of DNA, in transformations with plasmid DNA only a very few transformants were obtained. However, the transformation efficiency could be improved by electroporation of intact cells, giving about 2 x 10(3) transformants per microgram of plasmid DNA. Since a transformation procedure and a cloning vector are now available, pathogenicity in C. michiganense subsp. michiganense can now be analyzed genetically. PMID:1898919
Marčetić, Mirjana D; Milenković, Marina T; Lakušić, Dmitar V; Lakušić, Branislava S
Hypericum aegypticum subsp. webbii is an evergreen shrub spread in Mediterranean part of central and southeastern Europe. The chemical composition and antimicrobial activity of the essential oil and MeOH extract of H. aegypticum subsp. webbii were investigated. The monoterpenes α-pinene (63.4 - 68.5%) and β-pinene (16.9 - 17.0%) were main compounds in the volatile oil from aerial parts. In the cluster analysis, the essential oil of H. aegypticum subsp. webbii was separated and chemically different from the oil of other subspecies of H. aegypticum as well as other Hypericum species from Greece. SIMPER analysis revealed that α-pinene (24.79%) was the component that contributed the most to differences between all oils. Also, there was extremely high overall dissimilarity between three subspecies of H. aegypticum. MeOH extract of aerial parts of H. aegypticum subsp. webbii contained flavonoids rutin (56.4 ± 0.9 mg/g), hyperoside and quercetin, and phenolic acids chlorogenic and caffeic acid, while naphthodianthrones were not detected. The antimicrobial activity of essential oil was moderate (MIC from 100 to >200 μg/ml), while MeOH extract inhibited the growth of Gram-positive bacteria Bacillus subtilis, Enterococcus faecalis, Staphylococcus epidermidis, and Micrococcus luteus (MIC 50 - 100 μg/ml), more pronounced than the extract of H. perforatum (MIC 200 - >200 μg/ml).
A major drawback of current whole-cell vaccines for Mycobacterium avium subsp. paratuberculosis(MAP) is the interference with diagnostic tests for bovine tuberculosis and paratuberculosis. The current study was designed to explore effects of immunization with a heat-killed whole cell vaccine (Mycop...
Salmonella enterica subsp. enterica serovar Cerro is an infrequent pathogen of humans and other mammals, but is frequently isolated from the hindgut of asymptomatic cattle in the United States. To further understand the genomic determinants of S. Cerro specificity for the bovine hindgut, the genome ...
Huh, Chang Ki; Hwang, Tae Yean
This study was performed to investigate the antifungal substances and the antifungal activity against fungi of lactic acid bacteria (LAB) isolated from kimchi. LAB from kimchi in Imsil showed antifungal activity against Penicillium brevicompactum strain FI02. LAB LI031 was identified as Lactobacillus sakei subsp. Antifungal substances contained in L. sakei subsp. ALI033 culture media were unstable at high pH levels. Both, the control and proteinase K and protease treated samples showed clear zones, suggesting that the antifungal substances produced by ALI033 were non-protein substances unaffected by protesases. Both, the control and catalase showed clear zones, suggesting that the antifungal metabolite was not H2O2. The molecular weights of the antifungal substances were ≤3,000 Da. The organic acid content of crude antifungal substances produced by L. sakei subsp. ALI033 showed high concentrations of lactic acid (502.47 mg/100 g). Therefore, these results suggest that antifungal substance produced by L. sakei subsp. ALI033 is most likely due to its ability in producing organic acid.
Nguyen, Scott V.; Bono, James L.; Smith, Timothy P. L.; Fields, Patricia I.; Dinsmore, Blake A.; Santovenia, Monica; Kelley, Christy M.; Wang, Rong; Bosilevac, Joseph M.; Harhay, Gregory P.
Salmonella enterica is a leading cause of enterocolitis for humans and animals. S. enterica subsp. enterica serovar Typhimurium infects a broad range of hosts. To facilitate genomic comparisons among isolates from different sources, we present the complete genome sequences of 10 S. Typhimurium strains, 5 each isolated from human and bovine sources. PMID:27811097
Medrano-Félix, Andrés; Estrada-Acosta, Mitzi; Jiménez, Maribel; Gómez-Gil, Bruno; León-Félix, Josefina; Amarillas, Luis
Salmonella is a widespread microorganism and a common causative agent of food-borne illnesses. Salmonella enterica subsp. enterica serotype Oranienburg is highly prevalent in surface water from tropical ecosystems and is not commonly related to illnesses. Here, we report the first genome sequence of Salmonella Oranienburg strain S-76, isolated from an aquatic environment. PMID:24336368
Briczinski, Elizabeth P.; Loquasto, Joseph R.; Barrangou, Rodolphe; Dudley, Edward G.; Roberts, Anastasia M.; Roberts, Robert F.
Several probiotic strains of Bifidobacterium animalis subsp. lactis are widely supplemented into food products and dietary supplements due to their documented health benefits and ability to survive within the mammalian gastrointestinal tract and acidified dairy products. The strain specificity of these characteristics demands techniques with high discriminatory power to differentiate among strains. However, to date, molecular approaches, such as pulsed-field gel electrophoresis and randomly amplified polymorphic DNA-PCR, have been ineffective at achieving strain separation due to the monomorphic nature of this subspecies. Previously, sequencing and comparison of two B. animalis subsp. lactis genomes (DSMZ 10140 and Bl-04) confirmed this high level of sequence similarity, identifying only 47 single-nucleotide polymorphisms (SNPs) and four insertions and/or deletions (INDELs) between them. In this study, we hypothesized that a sequence-based typing method targeting these loci would permit greater discrimination between strains than previously attempted methods. Sequencing 50 of these loci in 24 strains of B. animalis subsp. lactis revealed that a combination of nine SNPs/INDELs could be used to differentiate strains into 14 distinct genotypic groups. In addition, the presence of a nonsynonymous SNP within the gene encoding a putative glucose uptake protein was found to correlate with the ability of certain strains to transport glucose and to grow rapidly in a medium containing glucose as the sole carbon source. The method reported here can be used in clinical, regulatory, and commercial applications requiring identification of B. animalis subsp. lactis at the strain level. PMID:19801460
This study reports a de novo assembled draft genome sequence of Xylella fastidiosa subsp. multiplex strain BB01 causing blueberry bacterial leaf scorch in Georgia, USA. The BB01 genome is 2,517,579 bp with a G+C content of 51.8% and 2,943 open reading frames (ORFs) and 48 RNA genes....
Wilk, Tímea; Szabó, Móni; Szmolka, Ama; Kiss, János; Olasz, Ferenc; Nagy, Béla
Four strains of Salmonella enterica subsp. enterica serovar Infantis isolated from humans (1980 to 1982) and broiler chickens (2016) have been sequenced. They represent the early and recent peak incidences of this serovar in Hungary. Genome sequences of these isolates provide comparative data on the evolution and rise of an endemic S Infantis clone in Hungary.
Sechi, Leonardo A.; Manuela, Mura; Francesco, Tanda; Amelia, Lissia; Antonello, Solinas; Giovanni, Fadda; Stefania, Zanetti
Crohn's disease is a chronic inflammatory disease of the gastrointestinal tract of unknown etiology. We report on the presence of cell wall-deficient Mycobacterium avium subsp. paratuberculosis in 35 of 48 paraffin-embedded tissue specimens from 33 patients with Crohn's disease by in situ hybridization with IS900 as a probe. PMID:11724871
Culture of Mycobacterium avium subsp. paratuberculosis (MAP) from feces has been considered the gold standard for the diagnosis of paratuberculosis for many years. However, direct fecal PCR is becoming more widely used today, demonstrating similar sensitivity and specificity to culture. To ensure ef...
A new TaqMan real-time PCR assay was developed for the simultaneous quantitative detection of two seedborne maize pathogens in a single assay. Pantoea stewartii subsp. stewartii (Pnss) (syn. Erwinia stewartii) is the causal agent of Stewart's bacterial wilt and leaf blight of maize. Stewart's wilt i...
Several novel antigens of Mycobacterium avium subsp. paratuberculosis have been studied as vaccine components and their immunogenicity has been evaluated. Previously, we reported that 85 antigen complex (85A, 85B, and 85C), superoxide dismutase (SOD), and 35kDa protein could induce significant lymph...
Fecteau, Marie-Eve; Hovingh, Ernest; Whitlock, Robert H.; Sweeney, Raymond W.
The goal of this study was to determine the persistence of Mycobacterium avium subsp. paratuberculosis (MAP) in soil, crops, and ensiled feeds following manure spreading. This bacterium was often found in soil samples, but less frequently in harvested feeds and silage. Spreading of manure on fields used for crop harvest is preferred to spreading on grazing pastures. PMID:24179246
Casteñeda-Ruelas, Gloria M.; Carreón-Gaxiola, César; Castelán-Sánchez, Hugo G.; Acatzi-Silva, Abraham; Romero-Martínez, Salvador; García-Molina, Alejandra
ABSTRACT Salmonella enterica subsp. enterica serovar Oranienburg is recognized as a foodborne pathogen widely distributed in the environment. Here, we report 18 draft genomes of S. Oranienburg strains isolated from rivers in the northwestern region of Mexico. PMID:28280020
Huh, Chang Ki; Hwang, Tae Yean
This study was performed to investigate the antifungal substances and the antifungal activity against fungi of lactic acid bacteria (LAB) isolated from kimchi. LAB from kimchi in Imsil showed antifungal activity against Penicillium brevicompactum strain FI02. LAB LI031 was identified as Lactobacillus sakei subsp. Antifungal substances contained in L. sakei subsp. ALI033 culture media were unstable at high pH levels. Both, the control and proteinase K and protease treated samples showed clear zones, suggesting that the antifungal substances produced by ALI033 were non-protein substances unaffected by protesases. Both, the control and catalase showed clear zones, suggesting that the antifungal metabolite was not H2O2. The molecular weights of the antifungal substances were ≤3,000 Da. The organic acid content of crude antifungal substances produced by L. sakei subsp. ALI033 showed high concentrations of lactic acid (502.47 mg/100 g). Therefore, these results suggest that antifungal substance produced by L. sakei subsp. ALI033 is most likely due to its ability in producing organic acid. PMID:27069906
Salmonella enterica subsp. enterica serovar Thompson strains RM1984 (CADPH-99A2334) and RM1986 (CADPH -99A2345) are clinical isolates from 1999, putatively related to an outbreak in California from contaminated cilantro. We report the complete genome sequences and annotation of these two S. Thompson...
Foddai, Antonio; Elliott, Christopher T; Grant, Irene R
Thermal inactivation experiments were carried out to assess the utility of a recently optimized phage amplification assay to accurately enumerate viable Mycobacterium avium subsp. paratuberculosis cells in milk. Ultra-heat-treated (UHT) whole milk was spiked with large numbers of M. avium subsp. paratuberculosis organisms (10(6) to 10(7) CFU/ml) and dispensed in 100-microl aliquots in thin-walled 200-microl PCR tubes. A Primus 96 advanced thermal cycler (Peqlab, Erlangen, Germany) was used to achieve the following time and temperature treatments: (i) 63 degrees C for 3, 6, and 9 min; (ii) 68 degrees C for 20, 40, and 60 s; and (iii) 72 degrees C for 5, 10, 15, and 25 s. After thermal stress, the number of surviving M. avium subsp. paratuberculosis cells was assessed by both phage amplification assay and culture on Herrold's egg yolk medium (HEYM). A high correlation between PFU/ml and CFU/ml counts was observed for both unheated (r(2) = 0.943) and heated (r(2) = 0.971) M. avium subsp. paratuberculosis cells. D and z values obtained using the two types of counts were not significantly different (P > 0.05). The D(68 degrees C), mean D(63 degrees C), and D(72 degrees C) for four M. avium subsp. paratuberculosis strains were 81.8, 9.8, and 4.2 s, respectively, yielding a mean z value of 6.9 degrees C. Complete inactivation of 10(6) to 10(7) CFU of M. avium subsp. paratuberculosis/ml milk was not observed for any of the time-temperature combinations studied; 5.2- to 6.6-log(10) reductions in numbers were achieved depending on the temperature and time. Nonlinear thermal inactivation kinetics were consistently observed for this bacterium. This study confirms that the optimized phage assay can be employed in place of conventional culture on HEYM to speed up the acquisition of results (48 h instead of a minimum of 6 weeks) for inactivation experiments involving M. avium subsp. paratuberculosis-spiked samples.
Guarcello, Rosa; De Angelis, Maria; Settanni, Luca; Formiglio, Sabino; Gaglio, Raimondo; Minervini, Fabio; Moschetti, Giancarlo; Gobbetti, Marco
Accumulation of biogenic amines (BAs) in cheese and other foods is a matter of public health concern. The aim of this study was to identify the enzyme activities responsible for BA degradation in lactic acid bacteria which were previously isolated from traditional Sicilian and Apulian cheeses. The selected strains would control the concentration of BAs during cheese manufacture. First, 431 isolates not showing genes encoding the decarboxylases responsible for BA formation were selected using PCR-based methods. Ninety-four out of the 431 isolates degraded BAs (2-phenylethylamine, cadaverine, histamine, putrescine, spermine, spermidine, tyramine, or tryptamine) during cultivation on chemically defined medium. As shown by random amplification of polymorphic DNA-PCR and partial sequencing of the 16S rRNA gene, 78 of the 94 strains were Lactobacillus species (Lactobacillus casei, Lb. fermentum, Lb. parabuchneri, Lb. paracasei, Lb. paraplantarum, and Lb. rhamnosus), Leuconostoc species (Leuconostoc lactis and Ln. mesenteroides), Pediococcus pentosaceus, Lactococcus lactis, Streptococcus species (Streptococcus gallolyticus and S. thermophilus), Enterococcus lactis, and Weissella paramesenteroides A multicopper oxidase-hydrolyzing BA was purified from the most active strain, Lb. paracasei subsp. paracasei CB9CT. The gene encoding the multicopper oxidase was sequenced and was also detected in other amine-degrading strains of Lb. fermentum, Lb. paraplantarum, and P. pentosaceus Lb. paracasei subsp. paracasei CB9CT and another strain (CACIO6CT) of the same species that was able to degrade all the BAs were singly used as adjunct starters for decreasing the concentration of histamine and tyramine in industrial Caciocavallo cheese. The results of this study disclose a feasible strategy for increasing the safety of traditional cheeses while maintaining their typical sensorial traits.
Fritsch, Isabel; Luyven, Gabriele; Köhler, Heike; Lutz, Walburga
Multitarget genotyping of the etiologic agent Mycobacterium avium subsp. paratuberculosis is necessary for epidemiological tracing of paratuberculosis (Johne's disease). The study was undertaken to assess the informative value of different typing techniques and individual genome markers by investigation of M. avium subsp. paratuberculosis transmission between wild-living red deer and farmed cattle with known shared habitats. Fifty-three M. avium subsp. paratuberculosis type II isolates were differentiated by short sequence repeat analysis (SSR; 4 loci), mycobacterial interspersed repetitive-unit–variable-number tandem-repeat analysis (MIRU-VNTR; 8 loci), and restriction fragment length polymorphism analysis based on IS900 (IS900-RFLP) using BstEII and PstI digestion. Isolates originated from free-living red deer (Cervus elaphus) from Eifel National Park (n = 13), six cattle herds living in the area of this park (n = 23), and five cattle herds without any contact with these red deer (n = 17). Data based on individual herds and genotypes verified that SSR G2 repeats did not exhibit sufficient stability for epidemiological studies. Two common SSR profiles (without G2 repeats), nine MIRU-VNTR patterns, and nine IS900-RFLP patterns were detected, resulting in 17 genotypes when combined. A high genetic variability was found for red deer and cattle isolates within and outside Eifel National Park, but it was revealed only by combination of different typing techniques. Results imply that within this restricted area, wild-living and farmed animals maintain a reservoir for specific M. avium subsp. paratuberculosis genotypes. No host relation of genotypes was obtained. Results suggested that four genotypes had been transmitted between and within species and that one genotype had been transmitted between cattle herds only. Use of multitarget genotyping for M. avium subsp. paratuberculosis type II strains and sufficiently stable genetic markers is essential for reliable
Tohno, Masanori; Kobayashi, Hisami; Tajima, Kiyoshi; Uegaki, Ryuichi
Paddy rice has been of particular interest as a forage crop in Japan. In this study, the isolated strains TO1000, TO1001, TO1002, and TO1003 were characterized by phenotypic and genotypic approaches. These strains were identified as Lactobacillus plantarum subsp. plantarum by species-specific PCR. Phenotypic characteristics varied among different strains of the same subspecies, and the strains represented unique and diverse phenotypes related to fermentation factors, such as carbohydrate assimilation and range of pH and temperature allowing growth. PCR analysis revealed that the patterns of presence/absence of known plantaricin genes differed in a strain-specific manner. Using these strains as inoculants for preparation of whole crop paddy rice silage, fermentation quality was significantly improved, as shown by lower pH, higher lactic acid content, and inhibition of the growth of undesirable microorganisms such as molds, coliform bacteria, and clostridia, after 30 and 60 days of storage, with effectiveness differing from strain to strain. These observations suggest that suitable candidates for bacterial inoculants in silage preparation should be screened at the strain level. Strain TO1002 may be useful for producing silage inoculants for the production of well-preserved whole crop paddy rice silage.
Suppression-subtractive hybridization as a strategy to identify taxon-specific sequences within the Mycoplasma mycoides Cluster: design and validation of an M. capricolum subsp. capricolum-specific PCR assay.
Maigre, Laure; Citti, Christine; Marenda, Marc; Poumarat, François; Tardy, Florence
The phylogenetically related Mycoplasma capricolum subsp. capricolum and M. mycoides subsp. mycoides biotype Large Colony are two small-ruminant pathogens involved in contagious agalactia. Their respective contributions to clinical outbreaks are not well documented, because they are difficult to differentiate with the current diagnostic techniques. In order to identify DNA sequences specific to one taxon or the other, a suppression-subtractive hybridization approach was developed. DNA fragments resulting from the reciprocal subtraction of the type strains were used as probes on a panel of M. capricolum subsp. capricolum and M. mycoides subsp. mycoides biotype Large Colony strains to assess their intrataxon specificity. Due to a high intrataxon polymorphism and important cross-reactions between taxa, a single DNA fragment was shown to be specific for M. capricolum subsp. capricolum and to be present in all M. capricolum subsp. capricolum field isolates tested in this study. A PCR assay targeting the corresponding gene (simpA51) was designed that resulted in a 560-bp amplification only in M. capricolum subsp. capricolum and in M. capricolum subsp. capripneumoniae (the etiological agent of contagious caprine pleuropneumonia). simpA51 was further improved to generate a multiplex PCR (multA51) that allows the differentiation of M. capricolum subsp. capripneumoniae from M. capricolum subsp. capricolum. Both the simpA51 and multA51 assays accurately identify M. capricolum subsp. capricolum among other mycoplasmas, including all members of the M. mycoides cluster. simpA51 and multA51 PCRs are proposed as sensitive and robust tools for the specific identification of M. capricolum subsp. capricolum and M. capricolum subsp. capripneumoniae.
Purified protein derivatives (PPD’s) were prepared from the cultured filtrate of Mycobacterium avium subsp. paratuberculosis (MAP) ATCC strain 19698. Production of PPD has historically been problematic for maintaining optimal floating cultures yielding defined immunogenic components. To obtain mor...