Roumanian Archives Of Microbiology And Immunology[JOURNAL]
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200 papers
Architecture and physiology of microbial biofilms.
Lazăr V, Chifiriuc MC
Roum Arch Microbiol Immunol · 2010 · PMID 21235137
The microbial biofilm, composed by a single or multiple species, is defined as a sessile community of microbial cells irreversibly attached to a substratum or an interface and also among them, embedded in a matrix of ext...
The microbial biofilm, composed by a single or multiple species, is defined as a sessile community of microbial cells irreversibly attached to a substratum or an interface and also among them, embedded in a matrix of extracellular polymeric substances as their own products, exhibiting a modified phenotype concerning the rate of growth and gene transcription. The biofilm is considered a primitive form of cellular differentiation, with primitive circulatory system, homeostasis and "integrality", similar to eukaryotic tissues in their intercellular cooperation. A microbial biofilm is considered to be the most successful and competitive expression of the prokaryotic genome--biofilm cells being metabolically more efficient and well protected, exhibiting resistance to different stress factors, including host defence mechanisms and antibiotics. The ability of the bacterial cells to behave as a community is the result of a complex intra- and inter-cellular communication based on a signaling system regulated by quorum-sensing and response (QS), mechanism ubiquitous in bacteria, and implicated in the regulation of very different and complex physiological processes, depending on cellular density. The language used for this intercellular communication is based on small, self-generated signal molecules known as bacterial pheromones with different chemical structures (N-homoserine lactones and derivatives in Gram-negative, and octapeptides, amino acids respectively in Gram-positive bacteria). The signal molecules level required for a specific response is very low in comparison with those of intracellular hormones. The aim of this review is to present the development, architecture and physiology of microbial biofilms.
Antimicrobial activity of some new of 2-(4-ethyl-phenoximethyl) benzoic acid thioureides against planktonic cells.
Drăcea O, Babeş C, Limban C … +3 more , Delcaru C, Chifiriuc MC, Israil AM
Roum Arch Microbiol Immunol · 2010 · PMID 21235136
The aim of the present study was to evaluate the antimicrobial activity of new 2-(4-ethyl-phenoxymethyl) benzoic acid thioureides. The synthesis of the new compounds was done in three steps starting with the synthesis of...
The aim of the present study was to evaluate the antimicrobial activity of new 2-(4-ethyl-phenoxymethyl) benzoic acid thioureides. The synthesis of the new compounds was done in three steps starting with the synthesis of 2-(4-ethyl-phenoxymethyl) benzoic acid. In the second stage, the 2-(4-ethyl-phenoxymethyl)-benzoyl chloride was prepared and the new thioureides were synthesized in the third step by the reaction of 2-(4-ethyl-phenoxymethyl) benzoyl isothiocyanate with various primary aromatic amines. The original compounds were screened for their in vitro antimicrobial activity against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) as well as to fungal strains (Candida albicans, Aspergillus niger), using both reference and clinical, multidrug resistant strains. The qualitative screening of the susceptibility spectra of various microbial strains versus these compounds was performed by three adaptated diffusion methods: (1) impregnation of the filter paper disks with the respective substance solutions, (2) distribution of the tested solutions into agar wells and (3) spotting of the respective solutions on the solid medium previously inoculated with the microbial suspensions. The quantitative assay of the antimicrobial activity was performed by broth microdilution method in 96-well microplates in order to establish the minimal inhibitory concentration (MIC). The tested compounds exhibited specific antimicrobial activity with MICs ranging from 3.9 microg/mL to 250 microg/mL.
Phenotypic and molecular methods used for identification of oral streptococci and related microorganisms.
Damian M, Palade AM, Băltoiu M … +3 more , Petrini A, Păuna M, Roseanu A
Roum Arch Microbiol Immunol · 2010 · PMID 21235135
The oral cavity contains the greatest biodiversity, over 70 species being isolated from mouth mucosa, saliva, denture surfaces and/or dental-plaque. The oral streptococci, representing over 80% of the mouth micro flora,...
The oral cavity contains the greatest biodiversity, over 70 species being isolated from mouth mucosa, saliva, denture surfaces and/or dental-plaque. The oral streptococci, representing over 80% of the mouth micro flora, are able to synthesize glucosyl-transferases, enzymes involved in glucans production. Glucans are involved in production of an extracellular slime layer promoting adhesion and formation of a dental plaque biofilm. The 43 isolates studied obtained from partially and/or totally edentulous, were identified by VITEK system using gram-positive identification cards. Species-specific regions within the genes coding for glucosyl-transferases (gtf genes) were targeted for PCR identification of isolates. Sequencing of 16S rRNA was used as gold standard for strain confirmation. VITEK system identified a number of 11 strains as S. mitis/oralis, 12 strains as S. anginosus/gordonii, 12 strains as S. sanguinis/parasanguinis, 3 strains as S. salivarius, 3 strains as S. plurianimalium, 1 strain as S. cristatus and 1 strain as S. alactolyticus, respectively. The PCR system targeting gtf genes was able to identify S. oralis, S. salivarius and S. gordonii strains. Sequence of 16S rRNA discriminated among streptococci species and revealed 16 strains of Leuconostoc mesenteroides. Many studies are needed in order to select the most reliable phenotypic and genotypic methods in order to improve the identification algorithm for oral streptococci used by clinical laboratories. Their accurate identification is mandatory for better understanding their role in human infections.
Regulatory T cells and TH1/TH2 cytokines as immunodiagnosis keys in systemic autoimmune diseases.
Ursaciuc C, Surcel M, Ciotaru D … +5 more , Dobre M, Pirvu IR, Munteanu AN, Alecu M, Huică R
Roum Arch Microbiol Immunol · 2010 · PMID 21235134
We assessed Helper T-cell involvement and possibilities to quantify the cell-based immune response in systemic autoimmune diseases (SAID) in 14 systemic lupus erythematosus (SLE) and 7 rheumatoid arthritis (RA) patients....
We assessed Helper T-cell involvement and possibilities to quantify the cell-based immune response in systemic autoimmune diseases (SAID) in 14 systemic lupus erythematosus (SLE) and 7 rheumatoid arthritis (RA) patients. The goals of investigation were T-CD4+/T-CD8+ ratio, regulatory T cells (Treg) status and TH1/TH2 serum cytokine profiles (IFN-gamma and IL-2, respectively IL-4 and IL-6). SLE group proved significant decreased average Treg value as compared to RA group and controls and showed significant low Treg incidence (86% patients). The distribution of high T-CD4+/T-CD8+ ratio registered no significant distinction among LES and RA groups. SAID patients presented low serum IFN-gamma (86% RA, 60% SLE), high IL-2 (57% RA) and high IL-6 (53% LES), but no significant IL-4 modification. We conclude that Treg percentage remains the only cellular criterion for SAID immune evaluation. In the same time, different secretion mechanisms seem to be involved in SAID, i.e. TH2 in SLE and TH1 in RA.
Comparative study of RT23 and IC-65 tuberculins tested on children with tuberculosis.
Ulea I, Murgoci G, Popa ML … +2 more , Popa L, Stavri H
Roum Arch Microbiol Immunol · 2010 · PMID 21235133
This study, conducted in 2009, proposed to evaluate and compare the biological potency of two different tuberculins, RT23 (Statens Serum Institute, Copenhagen) and IC-65 (Cantacuzino Institute, Bucharest) when administer...
This study, conducted in 2009, proposed to evaluate and compare the biological potency of two different tuberculins, RT23 (Statens Serum Institute, Copenhagen) and IC-65 (Cantacuzino Institute, Bucharest) when administered to 89 children with confirmed tuberculosis, admitted to Paediatric Department of Pneumophtysiology Institute, Bucharest. Mean age of subjects was 10.4 years [SD (standard deviation) = 5.2 years; variance = 27.2], and sex distribution in the group was: 55.1% girls and 44.9% boys. Tuberculin skin tests were performed using Mantoux method simultaneously with the two tuberculins in the same concentration, 2TU (tuberculin units)/0.1 ml. RT23 skin test reactions ranged from 8 mm to 18 mm (mean = 12.8 mm, SD = 2.1 mm, variance = 4.4; median = 12.0), and IC-65 reactions ranged from 8 mm to 18 mm (mean = 13.1 mm; SD = 2.1 mm; variance = 4.3; median = 13.0). The mean difference in paired reaction sizes for the two reagents was 0.04 mm and was not statistically different from zero (P value = 0.3). The difference in reaction sizes was = 2 mm in 70.8% and = 5 mm in 7.9% patients. With a cutoff of 10 mm to define a positive reaction, the results were highly correlated with a sensitivity of 98.9% for RT23 and 97.8% for IC-65. No statistically significant difference was established for the efficacy of the two commercially available PPD TST reagents, both tuberculins appearing to have equivalent potency.
Cold atmospheric plasma jet effects on V79-4 cells.
Lupu AR, Georgescu N
Roum Arch Microbiol Immunol · 2010 · PMID 21235132
The effects of cold plasmas are due to charged particles, reactive oxygen species (ROS), reactive nitrogen species (RNS), UV photons, and intense electric field. In order to obtain a more efficient action on mammalian ce...
The effects of cold plasmas are due to charged particles, reactive oxygen species (ROS), reactive nitrogen species (RNS), UV photons, and intense electric field. In order to obtain a more efficient action on mammalian cells (useful for cancer therapy), we used in our studies chemically activated cold plasma (He and O2 gas mixture). V79-4 cells were exposed to plasma jet for different time periods (30, 60, 90, 120 and 150s), using different combinations of helium and oxygen inputs (He:2.5l/min + 02:12.5ml/min; He:2.51/min + O2:25ml/min; He:2.51/min + O2:37.5 ml/min). Using MTT test we demonstrated that plasma jet induced cell viability decrease in all cases. The effect of chemically activated cold plasma--apoptosis or necrosis--depends on gas mixture and treatment period. Taking into account that ROS density in cell microenvironment is related to O2 percent in the gas mixture and treatment period, we can presume that cell death is due to ROS produced in plasma jet.
The effects of some Curdlan derivatives on Dectin-1 expression and cytokine production in human peripheral blood mononuclear cells.
Apetrei NS, Călugăru A, Bădulescu MM … +6 more , Lupu AR, Moscovici M, Mocanu G, Mihai D, Szegli G, Cremer L
Roum Arch Microbiol Immunol · 2010 · PMID 21235131
The cells of immune system such as monocytes and macrophages are in first line defence against dangerous signals. In the present paper the recognition of Dectin 1 receptors and the modulation of Interleukin-10 (IL-10) an...
The cells of immune system such as monocytes and macrophages are in first line defence against dangerous signals. In the present paper the recognition of Dectin 1 receptors and the modulation of Interleukin-10 (IL-10) and Tumor Necrosis Factor-alpha (TNF-alpha) cytokine production by Curdlan and Curdlan derivatives in peripheral blood mononuclear cells (PBMCs) were studied. The effect of Curdlan or Curdlan derivatives on the expression of Dectin 1 receptors in PBMCs was revealed by flow-cytometry and the levels of IL-10 and TNFalpha were measured by ELISA kit in supernatants of PBMCs cultured in presence or absence of Curdlan, Curdlan derivatives and LPS. Our results suggested that Curdlan and Curdlan derivatives were able to increase the expression of Dectin-1 receptors on monocyte cells. The combined treatment of Curdlan/Curdlan derivatives and Pam3Cys produced an increase of CD14+ cells possessing Dectin-1 receptors. We demonstrated that Curdlan (at 20 microg unique dose) up-regulated TNF-alpha production and down-regulated IL-10 production in PBMCs. Conversely, Palm CM/SP-Curdlan (20 microg unique dose) was able to down-regulate TNF-alpha production and to up-regulate IL-10 production in PBMCs. For instance, Palm CM/SP-Curdlan determined a 5 times decrease of TNF-alpha production than Curdlan. Regarding the effect of Palm CM/SP-Curdlan on IL-10 production in PBMCs, we noticed that the level of IL-10 was about 4 times greater than Curdlan activity. We observed that a combined treatment of Curdlan/Curdlan derivatives and LPS induced about 5 times decrease in TNF-alpha production in PBMCs. IL-10 production induced by Palm CM/SP-Curdlan and LPS was about 6 times greater than the combined effect of Curdlan and LPS. The treatment of PBMCs with SP-Curdlan alone affected neither TNF-alpha production nor IL-10 production. Our results are in accordance with other studies demonstrating that Dectin-1 and TLR2/TLR6 signaling combine to enhance the responses triggered by each receptor and the signaling pathway induced by Dectin-1 could mediate the production of pro-inflammatory cytokines.
Biomarkers discovery in cancer--up-dates in methodology.
Tacu C, Neagu M, Constantin C … +1 more , Sajin M
Roum Arch Microbiol Immunol · 2010 · PMID 21053784
Biomarkers are biomolecules that can indicate normal/pathological processes, or physiological responses to therapy. Due to the serum abundance in proteins, such as albumin and lypo/glycoproteins, biomarkers are difficult...
Biomarkers are biomolecules that can indicate normal/pathological processes, or physiological responses to therapy. Due to the serum abundance in proteins, such as albumin and lypo/glycoproteins, biomarkers are difficult to assess. Serum biomarkers identification can contribute to personalized medicine and improve cancer diagnostic and prognostic. The paper summarizes some of the proteomics techniques and the workflow used for protein signatures identification associated to cancer development. Thus, biomarkers validated for prostatic, breast, cervical or lung cancers are presented as examples for clinical application of serum markers. In spite of the continuous research efforts, there are only few validated biomarkers that have proved a good predictive power in cancer. Modern technology and the combination of various techniques used for proteins quantification represent important means for the identification and validation of new biomarkers.
In vitro assessment of the antimicrobial activity of new N-acyl-thiourea derivatives.
Diţu LM, Mihăescu G, Chifiriuc C … +4 more , Bleotu C, Morusciag L, Niţulescu GM, Missir A
Roum Arch Microbiol Immunol · 2010 · PMID 21053783
The qualitative screening of the susceptibility spectra of different microbial strains to the newly synthesized substances complexes was performed by adapted disk diffusion techniques, while the quantitative assay of the...
The qualitative screening of the susceptibility spectra of different microbial strains to the newly synthesized substances complexes was performed by adapted disk diffusion techniques, while the quantitative assay of the minimal inhibitory concentration (M.I.C., microg/cm3) value was based on liquid medium serial microdilutions. The compounds were solubilized in dimethylsulfoxide (DMSO). The in vitro biological screening effects were tested against a microbial inoculum of approximately 1.5 x 10(8) UFC/cm3, corresponding to 0.5 McFarland standard density, obtained from Gram positive (Staphylococcus aureus, Bacillus subtilis), Gram negative bacteria (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa) and fungal strains (Candida albicans). In order to investigate the influence of the subinhibitory concentration of the tested substances on the expression of different virulence features, the strains were incubated overnight in the presence of the newly synthesized thiourea derivatives (vol:vol) and different virulence features were investigated, i.e: adherence capacity to the cellular substrate represented by HeLa cells and to inert substrata quantified by slime test and soluble enzymatic virulence factors (haemolysins and other pore-forming toxins, proteases activity, DN-ase and siderophores production). The cytotoxicity was assessed microscopically, by observing the effect of the tested compounds on the cellular substratum integrity.
Investigation of the cytotoxic capacity of some adherent opportunistic enterobacterial strains by the MTT assay and transmission electron microscopy.
Lazăr V, Chifiriuc MC, Steward-Tull DE … +3 more , Bleotu C, Candlich D, Wardlaw AC
Roum Arch Microbiol Immunol · 2010 · PMID 21053782
The purpose of this study was to determine the cytotoxic effect on CaCo-2 intestinal cells of dialysates obtained from bacterial cultures of some enterobacterial opportunistic strains with different sources of isolation...
The purpose of this study was to determine the cytotoxic effect on CaCo-2 intestinal cells of dialysates obtained from bacterial cultures of some enterobacterial opportunistic strains with different sources of isolation (food, stool culture, acute diarrhoea, urine culture), previously tested and selected for their intensive adherence and invasion capacity to the cellular substratum and also for their cytotoxic effect on cell monolayers. In this study the level of cytotoxicity was measured quantitatively by means of the MTT assay and qualitatively by transmission electron microscopy (TEM). The MTT method uses a tetrazolium salt for the quantitative spectrophotometric assay of CaCo-2 cells survival and proliferation rates in the presence of bacterial dialysates. This test detects the viable cells, which are able to reduce the tetrazolium salt and offers the advantages of a very simple, rapid and precise method. For TEM examination the ultrathin sections were prepared following the standard protocols. The most cytotoxic strains proved to be Citrobacter freundii 93 strain isolated from stool culture, and Enterobacter cloacae 43, isolated from food followed by E. coli 115 strain isolated from acute diarrhoea. These results correlate well with TEM results pointing out the cytotoxic effect of Enterobacter cloacae 43 strain and also its ability to induce attachment and to destroy the cell surface (A/E) of HEp-2 cells. Besides their great adherence and invasion capacity, the production and release of cytotoxic factors into the extracellular medium represent virulence factors in these strains. This could be responsible for the increase of the pathogenic potential of opportunistic bacteria and explain their implication in the etiology of severe infections and food-borne diseases. This study proved that the virulence of opportunistic pathogens is not correlated with the strain's origin, the most evident virulence features being exhibited by an Enterobacter cloacae strain isolated from food.
TH1/TH2 cytokine levels as an indicator for disease progression in human immunodeficiency virus type 1 infection and response to antiretroviral therapy.
Osakwe CE, Bleotu C, Chifiriuc MC … +8 more , Grancea C, Oţelea D, Paraschiv S, Petrea S, Dinu M, Băicuş C, Streinu-Cercel A, Lazăr V
Roum Arch Microbiol Immunol · 2010 · PMID 21053781
A recent theory stipulates that during the course of HIV infection, there is a shift in immune response from T-helper 1 to T-helper 2 responses, characterised by elevated secretions of relevant cytokines. Cytokine profil...
A recent theory stipulates that during the course of HIV infection, there is a shift in immune response from T-helper 1 to T-helper 2 responses, characterised by elevated secretions of relevant cytokines. Cytokine profiles of 15 asymptomatic (treatment naïve) and 26 symptomatic (undergoing treatment) HIV-1 patients was determined to investigate the validity of this theory. HIV-1 RNA was quantified using the COBAS TaqMan HIV-1 test, CD4 T-cell counts with the FACSCalibur flow cytometer and IL-1, IL-4, IL-6, IL-10 and IFN-gamma cytokine levels by ELISA method. The asymptomatic group had significantly higher RNA levels (p-value; 0.000006) and lower CD4 T-cell counts than the symptomatic group indicating ongoing disease progression in the absence of antiretroviral treatment and a positive response to HIV treatment by the symptomatic group. IL-1, IL-4 and IFN-gamma were undetectable in most study subjects. IL-10 and IL-6 levels was relatively lower in the asymptomatic group (mean value; 206.352 pg/ml, 10.516 pg/ml) than the symptomatic group (mean value; 417.539, 18.387 pg/ml). Lower levels of proinflammatory cytokines (IL-1, IFN-gamma) in both study groups and elevated levels of anti-inflammatory cytokine IL-10, confirms that there is a shift in immune response as HIV infection progress to AIDS. In addition, the presence of a progressive trend of anti-inflammatory cytokine, IL-10 and proinflammatory cytokine, IL-6 in 12 symptomatic patients tested 3 months after antiretroviral therapy indicates an attempt by antiretrovirals to restore immune function.
Intranasal PUVA phototherapy in nasal polyposis--a pilot study.
Koreck A, Bella Z, Kadocsa E … +7 more , Perenyi A, Tiszlavicz L, Nemeth I, Kiss M, Olariu TR, Jori J, Kemeny L
Roum Arch Microbiol Immunol · 2010 · PMID 21053780
Nasal polyposis (NP) affects 4% of the general population, representing a major health problem. In spite of complex (surgical and medical) treatment, the relapse rate is high and it has a negative impact on the quality o...
Nasal polyposis (NP) affects 4% of the general population, representing a major health problem. In spite of complex (surgical and medical) treatment, the relapse rate is high and it has a negative impact on the quality of life. Recently we found that intranasal photochemotherapy with ultraviolet A light (PUVA) is effective in allergic rhinitis. In the present study PUVA was administered for 6 weeks in 7 patients with NP. Nasal lavages were performed in all patients before and at the end of the treatment; from four patients a biopsy specimen was also collected. Eosinophils significantly decreased in patients with NP and slightly in a patient who had associated aspirin sensitivity. IL-5 and eosinophil cationic protein (ECP) levels showed a decreasing trend in patients with NP and an increasing trend in patients with associated aspirin sensitivity. Our results suggest that intranasal PUVA might represent a future therapeutic method in a subset of patients with NP.
Correlation of XMAP and ELISA cytokine profiles; development and validation for immunotoxicological studies in vitro.
Codorean E, Nichita C, Albulescu L … +4 more , Răducan E, Popescu ID, Lonită AC, Albulescu R
Roum Arch Microbiol Immunol · 2010 · PMID 21053779
UNLABELLED: There is an emerging trend in immunotoxicological studies to use the multiplex technologies for testing the safety and the efficacy of new pharmaceuticals by using cytokines profiling as biomarker. The Lumine...
UNLABELLED: There is an emerging trend in immunotoxicological studies to use the multiplex technologies for testing the safety and the efficacy of new pharmaceuticals by using cytokines profiling as biomarker. The Luminex 200 xMAP (multi-analyte profiling) technology provides simultaneous measurement of multiple cytokines in small sample volumes, expressing rapidly the differences between various test compounds. The aim is to develop and validate the Luminex 200 multiplex immunoassays by correlation with ELISA (enzyme-linked immunosorbent assays) for implementation in evaluating cytokine profiling in immunotoxicological studies in vitro. METHODS: Human peripheral whole blood from healthy subject diluted 1+4 with RPMI 1640 was cultured 48 hours in 28 experimental variants: control, in presence of mitogens, bioflavonoid extracts (from Crataegus monogyna and Echinacea purpurea) as cytoprotectors and with a toxic compound [Pb(NO3)2]), separately or variously combined. IL-1beta and IL-2 were comparatively performed by xMAP and ELISA immunoassays from the same sample to initialize validation of multiplex cytokine panel: IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-alpha, IFN-gamma, usually performed by Luminex 200 system in our immunotoxicological studies. The results indicate similarly typed trends of cytokine values obtained by both methods, with comparable relative changes in presence of mitogens, bioflavonoids and toxic, respectively. Although xMAP absolute cytokine values were higher than ELISA values, the correlation between multiplexed assay and ELISA was good for IL-1beta and IL-2 with positive correlation coefficients near to 1. Conclusions. Quantitative differences between absolute values for IL-1beta and IL-2 obtained by xMAP and ELISA assays are found, but the relative values are comparable and the two methods keep similar trends in similar exposure conditions. The performance parameters of the xMAP assay and the good correlation coefficients with the "gold standard" ELISA recommend to validate the multiplex assay for analyzing cytokine profiles in immunotoxicological studies in vitro.
Protection of BALB/C mice against Brucella abortus 544 challenge by vaccination with combination of recombinant human serum albumin-l7/l12 (Brucella abortus ribosomal protein) and lipopolysaccharide.
Pakzad I, Rezaee A, Rasaee MJ … +3 more , Hossieni AZ, Tabbaraee B, Kazemnejad A
Roum Arch Microbiol Immunol · 2010 · PMID 21053778
BACKGROUND: The immunogenic Brucella abortus ribosomal protein L7/L12 and Lipopolysaccharide (LPS) are promising candidate antigens for the development of subunit vaccines against brucellosis. OBJECTIVE: This study was a...
BACKGROUND: The immunogenic Brucella abortus ribosomal protein L7/L12 and Lipopolysaccharide (LPS) are promising candidate antigens for the development of subunit vaccines against brucellosis. OBJECTIVE: This study was aimed to evaluate the protection of combination of recombinant HSA-L7/L12 fusion protein with LPS in Balb/c mouse. MATERIALS AND METHODS: The recombinant HSA-L7/L12 fusion protein in Saccharomyces cerevisiae was expressed and purified by affinity chromatography column. LPS was extracted by n-butanol, purified by ultracentrifugation. BALB/c mouses were immunized in 9 groups with PBS, HSA, tHSA-L7/L12, L7/L12, LPS, LPS+ HSA, LPS+ tHSA-L7/L12, LPS+ L7/L12, B. abortus S19. ELISA, LTT tests and challenging two weeks after last injection were carried out. Bacterial count of spleen of immunized BALB/c mouse was done four weeks after challenging with virulent strain B. abortus 544. RESULTS: In ELISA test the specific antibodies of tHSA-L7/L12 exhibited a dominance of immunoglobulin IgG1 over IgG2a. LPS-HSA and tHSA-L7/L12 + LPS produced a significantly higher antibody titer than LPS alone and L7/L12+LPS (P < 0.05). The predominant IgG subtype for LPS and L7/L12+LPS were IgG3. However, tHSA-L7/L12+ LPS and LPS+ HAS elicited predominantly IgG1 and IgG3 subtypes. In addition, the tHSA-L7/L12 fusion protein and L7/L12 elicited a strong T-cell proliferative response upon restimulation in vitro with recombinant tHSA-L7/L12 and L7/L12, suggesting the induction of a cellular immunity response in vivo. However, there was no significant difference proliferative response in L7/L12 and tHSA-L7/L12 fusion protein (P > 0.05). The combination of tHSA-L7/L12 fusion protein with LPS and B. abortus S19 induce higher level of protection against challenge with the virulent strain B. abortus 544 in BALB/c mice than other groups (P = 0.005). CONCLUSIONS: The combination of tHSA-L7/L12 fusion protein with LPS had higher protective ability than LPS and fusion protein distinctly.
Investigation of Helicobacter pylori infection in Jordanian patients using six enzyme immunoassays for immunoglobulin G (IGG) and IGA testing.
Abusini H, Abuelteen K, Elkarmi A … +2 more , Alenzi FQ, Lotfy M
Roum Arch Microbiol Immunol · 2009 · PMID 20583479
Helicobacter pylori (H. pylori) is the etiologic agent of a variety of gastrointestinal disorders. The rationale of the current study is to evaluate six enzyme immunoassays for detection of anti-H. pylori immunoglobulin...
Helicobacter pylori (H. pylori) is the etiologic agent of a variety of gastrointestinal disorders. The rationale of the current study is to evaluate six enzyme immunoassays for detection of anti-H. pylori immunoglobulin G (IgG) and IgA in Jordanian patients. Biopsy specimens and blood samples were obtained from patients underwent the endoscopy unit at Al-Bashir hospital in Jordan. The serum samples were investigated for the presence of anti-H. pylori IgG and IgA antibodies in patients with positive H. pylori biopsy samples. The results showed that IgG utilizing kits are more sensitive than of IgA kits and the IgA kits are more specific than of that IgG kits. Moreover, the biopsy is seemingly the gold standard for diagnosis of H. pylori is followed by H. pylori culture on brucella agar medium. An imperfect relation between the presence of H. pylori infection and the antibody response was existed that could be explained either because of the unsatisfactory sensitivities and specificities of the commercial kits used or because of weak immunological response in our patients to H. pylori antigens. Collectively, the H. pylori diagnosis that depends on the detection of anti-H. pylori antibodies in the hospital setting and in the screening programs should consider another test for confirmation the initial diagnosis.
Group B streptococcus colonization of Romanian women: phenotypic traits of isolates from vaginal swabs.
Usein CR, Petrini A, Georgescu R … +3 more , Grigore L, Străuţ M, Ungureanu V
Roum Arch Microbiol Immunol · 2009 · PMID 20583478
In the attempt to enrich the local contemporary laboratory data regarding the group B streptococcus (GBS) colonization, isolates obtained from the vaginal swab cultures were characterized for their serotype distribution...
In the attempt to enrich the local contemporary laboratory data regarding the group B streptococcus (GBS) colonization, isolates obtained from the vaginal swab cultures were characterized for their serotype distribution and antibiotic susceptibility. The 100 GBS isolates analyzed were collected during a four-month period of year 2009 from women screened in ambulatory for vaginal carriage of GBS. The GBS isolates were classified based on their capsular polysaccharide structures using commercially available antisera. Susceptibility to penicillin, ampicillin, erithromycin, clindamycin, tetracycline, ofloxacin, and chloramphenicol was initially tested using antibiotic disk diffusion technique according to CLSI guidelines. Minimum inhibitory concentrations of erythromycin and tetracycline for the isolates with reduced susceptibility were evaluated according to the CLSI criteria and macrolide-lincosamide-streptogramin B (MLSB) resistance was investigated by a double-disk test with erythromycin and clindamycin disks. All the GBS isolates were serotypeable. Their distribution comprised six different serotypes of which serotypes II (26%), III (26%), and Ia (19%) prevailed and no serotype VI, VII, and VIII isolates were found. Overall, the GBS isolates were fully susceptible to penicillin and ampicillin, but the rates of susceptibility to the other antimicrobial agents tested were decreased, ranging from 87% for chloramphenicol to 5% for tetracycline. Reduced susceptibility to clindamycin and erythromycin was detected in 18% and 19% of isolates, respectively. For the latter, 84% displayed a constitutive MLSB phenotype, 11% had an inducible MLSB phenotype, and M phenotype was expressed by 5% of them. Erythromycin-resistant GBS isolates displayed concurrently resistance to at least one more antibiotic. In conclusion, according to our study the most frequent GBS serotypes isolated from the vaginal microflora were II and III, followed by serotype Ia. While the GBS isolates remain susceptible to beta-lactams, resistance to alternative antimicrobial drugs such as erythromycin and clindamycin seems to be an increasing concern for our region. Further phenotypic and genotypic studies are required to identify specific aspects of GBS strains colonizing or infecting the local population.
Antibiotic resistance of Gram negative bacilli strains isolated from the Intensive Care Unit in Fundeni Clinical Institute, Bucharest, Romania.
Borcan E, Ghiţă CM, Chifiriuc MC … +3 more , Măruţescu L, Isar C, Lazăr V
Roum Arch Microbiol Immunol · 2009 · PMID 20583477
UNLABELLED: The aim of this study was to investigate the antibiotic resistance profile of 58 Gram negative bacilli strains (GNB): 36 non-fermentative GNB (NGNB), including 19 strains of Acinetobacter spp., 11 of Pseudomo...
UNLABELLED: The aim of this study was to investigate the antibiotic resistance profile of 58 Gram negative bacilli strains (GNB): 36 non-fermentative GNB (NGNB), including 19 strains of Acinetobacter spp., 11 of Pseudomonas aeruginosa, 6 of Stenotrophomonas maltophilia and 22 enterobacterial strains (14 strains of KEHSs, 6 belonging to the group Proteus-Providencia and 2 Escherichia coli) isolated from nasal, pharyngeal exudates and also from bronchial secretions, from immuno-depressed patients admitted in the Intensive Care Unit of Fundeni Clinical Institute. METHHODS: the antibiotic susceptibility testing was performed according to CLSI 2009 recommendations and the production of beta-lactamases was investigated by ESBL chromogenic media, double disc diffusion test, ESBL E-test, Amp C E-test and MBL E-test. RESULTS: 68% of the enterobacterial strains produced extended-spectrum beta- lactamases (ESBL), 13.63% of them expressing simultaneously the Amp C enzyme. All enterobacterial strains were susceptible to carbapenems (Imipenem and Ertapenem). Metallo-beta lactamases production among NGNB strains with resistance to Imipenem was high (80%), these strains being also multi-resistant to the majority of tested antibiotics with the exception of colistin. CONCLUSIONS: our results showed that the majority of the analyzed strains were multi-drug resistant. Antibiotic multi-resistance and the increasing number of severe infections caused by these strains are a major issue for ICU, where patients with severe diseases and destabilized physiological condition are often admitted.
In vitro susceptibility of Erwinia amylovora (Burrill) Winslow et. al. to Citrus maxima essential oil.
Măruţescu L, Saviuc C, Oprea E … +5 more , Savu B, Bucur M, Stanciu G, Chifiriuc MC, Lazăr V
Roum Arch Microbiol Immunol · 2009 · PMID 20583476
Regulatory constraints and environmental and human health concerns have promoted the search for alternative bio-control strategies of fire blight, a destructive disease of rosaceous plants which produces serious losses i...
Regulatory constraints and environmental and human health concerns have promoted the search for alternative bio-control strategies of fire blight, a destructive disease of rosaceous plants which produces serious losses in apple and pear orchards all over the world. The aim of this study was to establish the antimicrobial activity of Citrus maxima essential oil against Erwinia amylovora. An agar diffusion method was used for the screening of the inhibitory effect of Citrus maxima essential oil on bacterial strains growth. The quantitative inhibitory effect of pomelo oil on in vitro biofilm development was established by a microtiter colorimetric assay. In order to investigate the ability of pomelo oil to interfere with bacterial adherence and subsequent biofilm development on leaves obtained from different pomaceous fruit trees species and cultivars: Pyrus (Napoca, Williams), Malus (Golden Delicious) and Cydonia (Aromate), leaves were immersed in pomelo oil for 1, 2, 3, 5 and 10 minutes before exposing them to bacterial colonization. The architecture of bacterial biofilms developed on leaf surface was analyzed using Confocal Scanning Laser Microscopy (CSLM). Our results showed that Citrus maxima essential oil inhibited the development of bacterial biofilms on leaves, pomelo oil being more active on Cydonia (Aromate) leaves when the leaves were treated for 5 minutes. The results obtained from this study may contribute to the development of new bio-control agents as alternative strategies to protect fruit trees from fire blight disease.
In vitro study of the inhibitory activity of usnic acid on dental plaque biofilm.
Chifiriuc MC, Diţu LM, Oprea E … +9 more , Liţescu S, Bucur M, Măruţescu L, Enache G, Saviuc C, Burlibaşa M, Trăistaru T, Tănăse G, Lazăr V
Roum Arch Microbiol Immunol · 2009 · PMID 20583475
The vegetal extracts are used as an ecological alternative to classical anti-infectious treatments based on antibiotics, exhibiting the advantage of reduced secondary effects. Most of these compounds are secondary metabo...
The vegetal extracts are used as an ecological alternative to classical anti-infectious treatments based on antibiotics, exhibiting the advantage of reduced secondary effects. Most of these compounds are secondary metabolites, especially aromatic substances synthesized by plants in a reduced concentration. The aim of this study was to investigate the influence of usnic acid against quorum sensing and response mechanisms involved in the initiation and development of the dental plaque biofilm and its tolerance to antimicrobials. Three samples of super-gingival dental plaque were treated for different time intervals with usnic acid at 200 ig/ml in dimethyl-sulfoxide, representing the MIC value. Each dental plaque sample was inoculated in Brain Heart Infusion medium to establish the microbial growing curve by viable cells counts using the tenfold microdilutions method. For strains identification there were used the microtest galleries: API 20Strep, API Staph, API 20NE, API 20E. MIC value for usnic acid was determined by twofold microdilution technique. Usnic acid selectively inhibited the biofilm development by Gram positive bacteria and the expression of haemolytic properties of strains isolated from the dental plaque. The growth curve of the isolated strains was affected by usnic acid, the changes consisting of the lag phase extension to 6-10 h (this time interval being considered as the persistence time of antimicrobial activity) and the significant decrease of the viable cell number and consecutively, the prolongation of the generation time. These effects are demonstrating the interference of the usnic acid with the intra- and interspecies signalling mechanisms based on quorum sensing and response and dependent on cell density, giving the possibility to use them as an active principle in some new pharmaceutical formula intended for the prevention and treatment of gingival and periodontal pathologies.
The influence of some probiotic supernatants on the growth and virulence features expression of several selected enteroaggregative E. coli clinical strains.
Lazăr V, Miyazaki Y, Hanawa T … +5 more , Chifiriuc MC, Diţu LM, Măruţescu L, Bleotu C, Kamiya S
Roum Arch Microbiol Immunol · 2009 · PMID 20583474
UNLABELLED: The purpose of this study was the assessment of the influence of three probiotic supernatants (Bifidobacterium breve ATCC 15700, Enterococcus faecium ATCC 19434, Lactobacillus casei subsp. casei ATCC 393) on...
UNLABELLED: The purpose of this study was the assessment of the influence of three probiotic supernatants (Bifidobacterium breve ATCC 15700, Enterococcus faecium ATCC 19434, Lactobacillus casei subsp. casei ATCC 393) on the growth (quantified by viable cell counts) and virulence features expression (adherence ability to HEp-2 cells and inert substratum- slime test) of several selected EAggEC diarrhoeagenic strains as well as the cytotoxicity of the respective supernatants on HEp-2 cells. RESULTS: Our in vitro studies are demonstrating that the selected supernatants, when added simultaneously with the bacterial culture are generally opposing to the adherence to the cellular substratum by the EAggEC strains. When added after the pre-adherence period, the supernatants did not change the adherence indexes of the EAggEC strains, but induced slight changes in the adherence pattern, reducing the frequency and size of bacterial aggregates. Only in few cases, the bacterial growth rate was slightly increased or sustained by the probiotic supernatants, a possible explanation being that we used supernatants obtained from 24 hrs fresh cultures, which are probably still containing some nutrients and probably also other growth factors. CONCLUSION: Our results are demonstrating that soluble probiotic metabolites accumulated in culture supernatants may interfere with the first step of adherence and colonization of the cellular and inert substrata by EAggEC strains, probablyby the cross-talk between probiotic soluble molecules and quorum-sensing mediators of opportunistic strains; so, direct contact between the probiotic and pathogenic bacteria are not always necessary for the occurrence of a protective effect, that could be partly mediated by the soluble molecules secreted by specific probiotic strains.
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