Microbios (Microbios)

Publications in this journal

• Article: Gluconic acid production by Acetobacter oxydans.

  EL-SAYED, M. ; SHAMS, H. ; EL-SHANSHORY, A. E.; SAMMOUR, R. H. and ABD EL-SALAM
  Microbios 02/2013;
• Article: Relationship between T lymphocyte responsiveness and T-helper1/T-helper2 type cytokine release in chronic hepatitis C: a critical reappraisal.

  S Antonaci, G Piazzolla, N Napoli, F S Vella, G Fiore, O Schiraldi
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  ABSTRACT: Recruitment of virus-specific T lymphocyte subpopulations to liver sites in chronic hepatitis C virus (HCV) infection implies a key role for the immune response in host-virus interaction. In spite of a multispecific and polyclonal cytotoxic function exerted by CD8+ lymphocytes, CD4-mediated activity is weak. This allows the infection to persist which in turn is responsible for the development of chronic hepatitis C (CH-C). Such a finding outlines the occurrence of a possible relationship between cytokine (CK) production by CD4 subsets, i.e. T helper (Th)1 or Th2 cells, and the clinical outcome. A prevalence of Th1-derived CK occurs in infected liver, while increased amounts of Th2-related CK are usually found in peripheral blood. Moreover, peripheral blood mononuclear cell (PBMC) cultures from CH-C subjects exhibit an impaired interferon (IFN)-gamma production and an increase of interleukin (IL)-12 p70 release after stimulation. The latter pattern seems to be due to the enhanced release of IL-12 p40 homodimers, which antagonize IL-12 p70 bioactivity and favour IL-10-induced effects. These results suggest that further extensive studies on the imbalance of the CK network at a molecular level are required to improve the therapeutical approach in CH-C subjects.
  Microbios 02/2001; 106(415):203-12.
• Article: Transformation of Curvularia lunata IM 2901 with pAN7-1 influences selected physiological properties of the fungus.

  A Kanwal, K Paraszkiewicz, J Długoński
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  ABSTRACT: Genetic analysis of Curvularia lunata IM 2901 transformants, previously obtained by electroporation with plasmid pAN7-1, was carried out. Isolates displayed several differences in hygromycin B resistance and their physiology. It was shown that plasmid pAN7-1 was integrated in different copy numbers and at different positions in the genome of the strains studied. Both the wild type and pAN7-1 isolates, when growing in liquid media, produced an extracellular emulsifying agent. The transformants differed in their growth kinetics, intensity of surfactant production and in the efficiency of cortexolone 11beta-hydroxylation, in comparison with the wild type. The micro-organisms varied in susceptibility to the lytic enzyme complex (Novozyme 234), which indicated the presence of differences in their cell wall composition and/or in architecture caused by an integrated plasmid pAN7-1.
  Microbios 02/2001; 104(407):27-38.
• Article: PCR cloning of the resuscitation-promoting factor (Rpf) gene from Micrococcus luteus, sequencing and expression in Escherichia coli.

  M Matsuda, M Togo, S Kagawa, J E Moore
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  ABSTRACT: A polymerase chain reaction (PCR) cloning procedure was developed for the resuscitation-promoting factor (Rpf) gene of Micrococcus luteus using strains NCIMB 13267, JCM 1464T, JCM 3347, and JCM 3348. A PCR product of the Rpf gene fragment was ligated into a cloning vector pBluescript II KS (+) with the restriction endonucleases Eco RI and Bam HI. The ligation mixture was used to transform Escherichia coli DH5alpha. The DNA sequence of the Rpf gene cloned from strain JCM 1464T was 84% homologous with that of NCIMB 13267, and from strains JCM 3347 and JCM 3348 it was 100% and 86% homologous, respectively. Recombinant Rpf proteins of M. luteus NCIMB 13267 and JCM 1464T after expression in E. coli BL21 harbouring the pET-19b-Rpf plasmid, and after purification, were approximately 16 kD for both strains.
  Microbios 02/2001; 104(407):55-61.
• Article: Interrelation between synthesis and uptake of ectoine for the growth of the halotolerant Brevibacterium species JCM 6894 at high osmolarity.

  S Nagata, Y B Wang
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  ABSTRACT: The growth of a halotolerant Brevibacterium sp. JCM 6894 was examined in the presence of compatible solutes such as glycine betaine, ectoine (2-methyl-4-carboxy-3,4,5,6-tetrahydropyrimidine) and ectoine derivatives. The effect of competition between their uptake and synthesis in the cells was subjected to osmotic shift towards the higher salinity. Among each solute examined the supplement of ectoine or hydroxyectoine exhibited a remarkable stimulation on the growth of strain JCM 6894, regardless of the range of osmotic shifts, where the largest was 0-->2 M NaCl, the intermediate was 1-->2 M NaCl, and no shift was 2-->2 M NaCl. The growth rates of this strain were dependent on the amount of ectoine taken up, which was conspicuous for the largest osmotic shift and during the first few hours of incubation after transfer. The cells subjected to 1-->2 M NaCl and 2-->2 M NaCl transfers took up less ectoine and this resulted in lower growth rates than those of cells with the largest osmotic shift (0-->2 M NaCl). The role of other compatible solutes which accumulated is discussed in relation to growth stimulation of strain JCM 6894.
  Microbios 02/2001; 104(407):7-15.
• Article: Antibiotic susceptibility, serum response and surface properties of Klebsiella species.

  A Hostacká, Klokocníková
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  ABSTRACT: Altogether 130 clinical isolates of five Klebsiella species (K. pneumoniae, K. planticola, K. oxytoca, K. ornithinolytica and K. terrigena) were characterized, for their susceptibility to five antibiotics, for susceptibility to serum bactericidal activity and for their hydrophobic properties. All strains exhibited ampicillin resistance. Ampicillin/sulbactam, gentamicin and ofloxacin showed effectiveness in 63.1, 67.7 and 71.5% of the Klebsiella isolates. K. planticola manifested the highest level of resistance to these antibiotics. The majority of Klebsiella strains (93.9%) were susceptible to cefuroxime. Sixty-four strains (49.2%) were serum resistant and intermediate serum sensitivity was shown by 57 strains (43.8%). A high percentage of serum resistant strains (65%) was found in K. planticola. Moderately hydrophobic properties determined by adherence of bacteria to xylene were demonstrated in 25 strains (19.2%).
  Microbios 02/2001; 104(408):115-24.
• Article: Neutrophil apoptotic cell death: does it contribute to the increased infectious risk in aging?

  C Tortorella, G Piazzolla, N Napoli, S Antonaci
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  ABSTRACT: During the last few years, several studies have pointed out the imbalance of immune response with advancing age, which accounts for the increased susceptibility of elderly individuals to life-threatening diseases. This review is focused on the role of neutrophil apoptosis in the age-associated decline of cytotoxicity towards invading micro-organisms. The results indicate that the overall intrinsic mechanisms regulating neutrophil cell death are unaffected by age. Neutrophils from aged humans exhibit a diminished ability to be rescued by proinflammatory mediators, as well as a weak buffer capacity towards proapoptotic reactive oxygen species (ROS) generated during cell stimulation. Such events may hamper in vivo the accumulation of functionally active cells in inflammatory areas, thus contributing to the increased infection-related risk of morbidity and mortality with advanced age. The impact of these new findings in terms of therapeutic applications is discussed.
  Microbios 02/2001; 106(414):129-36.
• Article: Inhibition by the essential oils of peppermint and spearmint of the growth of pathogenic bacteria.

  H Imai, K Osawa, H Yasuda, H Hamashima, T Arai, M Sasatsu
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  ABSTRACT: The effects of the, essential oils of peppermint (Mentha piperita L.), spearmint Mentha spicata L.) and Japanese mint (Mentha, arvensis L.), of four major constituents of the esssential oil of peppermint, and of three major constituents of the essential oil of spearmint, on the proliferation of Helicobacter pylori, Salmonella enteritidis, Escherichia coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA) and methicillin sensitive Staphylococccus aureus (MSSA) were examined. The essential oils and the various constituents inhibited the proliferation of each strain in liquid culture in a dose-dependent manner. In addition, they exhibited bactericidal activity in phosphate-buffered saline. The antibacterial activities varied among the bacterial species tested but were almost the same against antibiotic-resistant and antibiotic-sensitive strains of Helicobacter pylori and S. aureus. Thus, the essential oils and their constituents may be useful as potential antibacterial agents for inhibition of the growth of pathogens.
  Microbios 02/2001; 106 Suppl 1:31-9.
• Article: Toxic effects of HgCl2 on the growth and oogonium formation in Oedogonium hatei.

  H V Singh
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  ABSTRACT: The effect of mercuric chloride on the germination and growth of swarmers and subsequent induction of oogonia was studied in Oedogonium hatei Kam. (Oedogoniales, Chorophyceae). HgCl2 within the concentration range of 0.01 to 1.0 mg/l produced a progressive increase in the initiation of germination and reduction in the growth of the alga. The percentage of oogonia formed, and mature oogonia developed, decreased linearly with a rise in the concentrations of HgCl2 employed. The results showed that 1 mg/l HgCl2 was highly toxic to the growth and/or multiplication of zoospores and further development of sexual structures in O. hatei. The germination of zoospores and growth of germlings were so severely affected that induction of oogonia remained completely inhibited at 1 mg/l HgCl2. Moreover, 2 mg/l of HgCl2 was lethal to the asexual zoospores.
  Microbios 02/2001; 106 Suppl 1:51-6.
• Article: Antibacterial activity of Karanj (Pongamia pinnata) and Neem (Azadirachta indica) seed oil: a preliminary report.

  M Baswa, C C Rath, S K Dash, R K Mishra
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  ABSTRACT: The antibacterial activity of Karanj (Pongamia pinnata) and Neem (Azadirachta indica) seed oil in vitro against fourteen strains of pathogenic bacteria was assessed. Using the tube dilution technique, it was observed that 57.14 and 21.42% of the pathogens were inhibited at 500 microl/ml; 14.28 and 71.42% at 125 microl/ml; and 28.57 and 7.14% at 250 microl/ml of Karanj and Neem oils, respectively. The activity with both the oils was bactericidal and independent of temperature and energy. Most of the pathogens were killed more rapidly at 4 degrees C than 37 degrees C. The activity was mainly due to the inhibition of cell-membrane synthesis in the bacteria.
  Microbios 02/2001; 105(412):183-9.
• Article: 2,4-dichlorophenoxyacetate/alpha-ketoglutarate dioxygenases from Burkholderia cepacia 2a and Ralstonia eutropha JMP134.

  R Poh, X Xia, I J Bruce, A R Smith
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  ABSTRACT: 2,4-Dichlorophenoxyacetate (2,4-D)/alpha-ketoglutarate (alpha-KG) dioxygenase has been purified to apparent homogeneity from Burkholderia cepacia strain 2a, which utilizes 2,4-D as sole carbon source. The enzyme required ferrous ions, and was a homodimer composed of subunits having an Mr of approximately 32,000. The reaction catalysed consumed one mol each of 2,4-D, alpha-KG and dioxygen, with the production of one mol each of succinate, 2,4-dichlorophenol and glyoxylate. Maximum activity was exhibited at pH 7.8 and 25 degrees C, and reactivity was enhanced by the presence of ascorbate and cysteine. Mn2+, Zn2+, Cu2+, Fe3+ and Co2+ were inhibitory, and chemical modification of the dioxygenase revealed that thiol groups were essential for activity. The enzyme was active towards other substituted phenoxyacetates, but reacted most rapidly with 2,4-D. The apparent Michaelis constants for 2,4-D and alpha-KG were 109 and 8.9 microM, respectively. The properties of this enzyme are compared with those of the 2,4-D/alpha-KG dioxygenase from Ralstonia eutropha JMP134, which exhibits a differing N-terminal amino-acid sequence, and a different temperature 'optimum', pH optimum, substrate specificity and sensitivity to thiol-binding reagents.
  Microbios 02/2001; 105(410):43-63.
• Article: Ultrastructural localization of succinate dehydrogenase in some bacteria, after treatment with Lubrol W1.

  N Cherepova, D Spasova, S Radoevska
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  ABSTRACT: The localization of succinate dehydrogenase in some gram-negative and gram-positive bacteria (Salmonella typhimurium, Pseudomonas pseudomallei, Pseudomonas aeruginosa and Listeria monocytogenes) treated with the surface membrane active agent, Lubrol W1, was studied by a cytochemical method combined with electron microscopy.
  Microbios 02/2001; 104(407):49-54.
• Article: Bioaccumulation of yttrium in Pseudomonas fluorescens and the role of the outer membrane component(s).

  V D Appanna, R D Hamel, E Pankar, S Puiseux-Dao
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  ABSTRACT: Pseudomonas fluorescens was grown in millimolar amounts of yttrium. The tolerance to yttrium appeared to be mediated by the ability of the organism to accumulate the trivalent metal predominantly in the outer membrane component(s). At the stationary phase of growth, 65 to 70% of the metal was associated with the constituent(s) of the outer membrane. Treatment with 2 mM (EDTA) did not release the metal. Incubation of the outer membrane fraction with yttrium led to further accumulation of the metal. The outer membrane equivalent to 1 mg of protein was shown to immobilize 175 microg of yttrium. There was no significant variation in uronic acid and the lipid contents of the control and yttrium-stressed cells as monitored by colorimetric assays. The protein profiles of the outer and inner membrane components obtained from the control and metal-stressed cells showed marked variations as revealed by sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis.
  Microbios 02/2001; 106(413):19-29.
• Article: Hydrocortisone, prednisolone and dexamethasone act on Aspergillus fumigatus in vitro susceptibility to itraconazole.

  I Ramondenc, C Pinel, S Parat, P Ambroise-Thomas, R Grillot
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  ABSTRACT: In a previous in vitro investigation from the same laboratory a therapeutic level of hydrocortisone enhanced the itraconazole susceptibility of a single strain of Aspergillus fumigatus. In the present work, the influence of therapeutic levels of hydrocortisone (1 microM), prednisolone (0.125 microM 0.25 microM and 0.5 microM) and dexamethasone (0.25 microM and 0.5 microM) on the itraconazole susceptibility of four A. fumigatus strains, was determined. A. fumigatus conidia were germinated either in the absence or in the presence of a glucocorticoid. The germinated conidia were then spread onto plates and grown either in the presence or in the absence of a glucocorticoid, together with increasing concentrations of itraconazole. The mean colony forming units (CFU) were measured. Two factor analyses of variance showed that hydrocortisone significantly (p <0.001) potentiated the action of itraconazole. The cytotoxic effect of prednisolone on the fungal strains added significantly to the effect of itraconazole (p <0.001). Dexamethasone was also cytotoxic to the fungus but, when used in conjunction with itraconazole, it effectively increased (p <0.01) the number of CFU. This study showed a direct effect of glucocorticoids, currently in use for patient therapy, on in vitro A. fumigatus susceptibility to itraconazole.
  Microbios 02/2001; 104(407):17-26.
• Article: Proflavine-mediated inactivation of Salmonella dublin exposed to visible sunlight in natural fresh water.

  V K Kussovski, A E Hristov, T S Radoucheva
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  ABSTRACT: The survival of Salmonella dublin exposed to visible sunlight, and heterotrophic bacteria in freshwater microcosms in the presence and absence of the photosensitizer proflavine, was studied. Enumeration of S. dublin and the heterotrophic bacteria showed that in both illuminated and nonilluminated systems (without proflavine) the bacteria remained viable and culturable for at least 6 days. The optimal proflavine concentration (no effect in the dark and a maximal photoinactivation of salmonellae after irradiation) was 2 mg l(-1). In contrast to S. dublin, the heterotrophic bacteria overcame the initial inhibitory effect of proflavine. The possible use of photosterilization against contamination with pathogenic bacteria in water model ecosystems, is discussed.
  Microbios 02/2001; 105(411):119-25.
• Article: Distribution of hepatitis C virus serotypes and duration of infection in HCV infected subjects from a geographical area in Southeast Italy.

  R Sacco, F Stella, R Leva, A Volpe, C Ranieri, A Pellegrino, C Picciarelli, R Buongiorno, P Dentico
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  ABSTRACT: Hepatitis C virus serotypes and the duration of infection HCV positive subjects from a restricted geographical area in Italy, were evaluated. HCV serotypes were determined by Murex serotyping assay. Serotypes were detected in 592 (88.0%) of 669 samples. Type 1 proved to be the most frequent (48.9%), followed by types 2 (29%), 3(4.5%) and 4 (2.1%). The transmission of HCV 3 and 4 were observed only in the past 20 years whilst those of other types were recorded during 40 or more years. The results support the view that the prevalence of different HCV types of infection in one restricted geographical area may be associated with the source and duration of infection.
  Microbios 02/2001; 106 Suppl 1:67-73.
• Article: Polyamine distribution profiles in newly validated genera and species within the Flavobacterium-Flexibacter-Cytophaga-Sphingobacterium complex.

  K Hamana, Y Nakagawa
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  ABSTRACT: Cellular polyamines of 58 strains belonging to the Flavobacterium-Flexibacter-Cytophaga-Sphingobacterium complex were analysed by HPLC. Homospermidine was found in all species of Flavobacterium, Chryseobacterium, Empedobacter, Myroides, Cellulophaga, Salegentibacter, Psychroserpens and Gelidibacter of the family Flavobacteriaceae. Flavobacterium ferrugineum located outside of this family also contained homospermidine. Cytophaga fermentans and C. xylanolytica belonging to the family Bacteroidaceae contained spermidine. Cytophaga marinoflava and C. latercula belonging to Flavobacteriaceae contained homospermidine. The Cytophaga hutchinsonii/C. aurantiaca group contained homospermidine which was the major polyamine in Flexibacter maritimus/ F. ovolyticus of the family Flavobacteriaceae. The Flexibacter sancti/F filiformis/ Cytophaga arvensicola group, F. elegans, F. ruber, F. canadensis, F. flexilis and F. tractuosus, were located separately in different six clusters, and contained homospermidine. The Flexibacter litoralis/F. polymorphus/F. aggregans group contained spermidine, which was detected in Flexibacter roseolus belonging to a divergent cluster. Sphingobacterium and Pedobacter species of the family Sphingobacteriaceae contained homospermidine. Polyamine profiles serve, as a phenotypic chemotaxonomic marker, for the classification of this complex.
  Microbios 02/2001; 106 Suppl 2:105-16.
• Article: Detection of antigenic surface proteins of Actinobacillus actinomycetemcomitans using the immunoblotting method.

  R Mineyama
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  ABSTRACT: Antigenic surface proteins of Actinobacillus actinomycetemcomitans (three strains), which can be recognized by antibodies in human serum, were examined using the Western blot method. By comparing the immunoblotting profiles between protease-treated cells and untreated cells, IgG-antigenic and IgM-antigenic surface proteins were found. The IgG-antigenic proteins revealed the following molecular weights: strain ATCC 29522, 52 and 49 kD; strain ATCC 29523, 45, 49, 52 and 70 kD; strain Y4, 36, 38, 44, 53 and 58 kD. Molecular weights of the IgM-antigenic proteins ranged from 50 to 92 kD: strain ATCC 29522, 68, 80, 90 and 92 kD; strain ATCC 29523, 62, 68 and 80 kD; strain Y4, 50, 64, 73, 81 and 86 kD. The IgG-antigenic proteins were very sensitive to trypsin and Bacillus licheniformis protease, but were resistant to V8 protease, while the IgM-antigenic proteins were sensitive to various proteases. These results suggested that IgG-antigenic and IgM-antigenic components were different from the serotype-specific antigen or species-specific antigen associated with polysaccharides or lipopolysaccharides with respect to molecular weights and that they were proteins.
  Microbios 02/2001; 106 Suppl 2:143-54.
• Article: In vitro effect of ampicillin/sulbactam on Acinetobacter species.

  A Hostacká
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  ABSTRACT: The effects of subinhibitory concentrations (sub-MIC) of ampicillin/sulbactam (AMP/sulbactam), on the surface hydrophobicity and the lipase activity of ten Acinetobacter strains, were examined. The alterations in the activities studied were strain and drug concentration dependent. Most of the strains treated showed a decrease in surface hydrophobicity to a different extent. The hydrophobic character of three strains exposed to 1/4 or 1/8 of the MIC of the antibiotic was changed to a hydrophilic state. The majority of Acinetobacter strains after treatment with antibiotic possessed increased lipolytic activity. AMP/sulbactam even at sub-MIC may interfere with possible virulence factors of Acinetobacter strains in vitro.
  Microbios 02/2001; 106 Suppl 2:97-104.
• Article: Demonstration of genome DNA diversity of strains of urease-positive thermophilic Campylobacter isolated from the natural environment by pulsed-field gel electrophoresis analysis.

  M Matsuda, H Ueno, T Shibuya, A Kaneko, S Kagawa, J E Moore
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  ABSTRACT: Pulsed-field gel electrophoresis (PFGE) analysis was carried out after separate digestion with Apa I, Sal I and Sma I of the genomic DNA from sixteen isolates of urease-positive thermophilic Campylobacter (UPTC) obtained from the natural environment, namely from oysters and mussels, in Northern Ireland. Five NCTC strains previously isolated in England were used for the analysis. Although the eight isolates of UPTC in Northern Ireland and a strain of UPTC in England showed that one or no fragments appeared after digestion with Apa I around 1,900 to 1,640 kb region of the gel, Apa I was shown to cut the genomic DNA from all of the other twelve strains of UPTC and Sal I and Sma I from all of the 21 strains in a distinctly different and distinguishable manner. Consequently, the present study clearly demonstrated that the sixteen isolates of UPTC in Northern Ireland and the five strains in England gave the diversity of the genomic DNA by using PFGE. Some strains of UPTC examined were shown to carry genomes from 1.6 to 1.9 Mb in length, thus the heterogeneous profiles of PFGE and the length of the genomes are thought to occur among the isolates of UPTC in Northern Ireland, as well as among the five representative strains of UPTC from NCTC.
  Microbios 02/2001; 106 Suppl 1:57-65.