Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva
A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS-PAGE and We......A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS...... suspension of bacterial cells grown for 18 h. All A, pleuropneumoniae strains had been previously serotyped using standard procedures, The polystyrene agglutination test was rapid (less than 3 min) and easy to perform. Overall a very good correlation (97.3%) with the standard techniques was found...
Zhan, Bujie; Angen, Øystein; Hedegaard, Jakob
Actinobacillus pleuropneumoniae is a bacterial pathogen that causes highly contagious respiratory infection in pigs and has a serious impact on the production economy and animal welfare. As clear differences in virulence between serotypes have been observed, the genetic basis should be investigat...... at the genomic level. Here, we present the draft genome sequences of the A. pleuropneumoniae serotypes 2 (strain 4226) and 6 (strain Femo)....
Michael T Karwacki
Full Text Available Cell-free extracts isolated from colony biofilms of Actinobacillus pleuropneumoniae serotype 5 were found to inhibit biofilm formation by Staphylococcus aureus, S. epidermidis and Aggregatibacter actinomycetemcomitans, but not by A. pleuropneumoniae serotype 5 itself, in a 96-well microtiter plate assay. Physical and chemical analyses indicated that the antibiofilm activity in the extract was due to high-molecular-weight polysaccharide. Extracts isolated from a mutant strain deficient in the production of serotype 5 capsular polysaccharide did not exhibit antibiofilm activity. A plasmid harboring the serotype 5 capsule genes restored the antibiofilm activity in the mutant extract. Purified serotype 5 capsular polysaccharide also exhibited antibiofilm activity against S. aureus. A. pleuropneumoniae wild-type extracts did not inhibit S. aureus growth, but did inhibit S. aureus intercellular adhesion and binding of S. aureus cells to stainless steel surfaces. Furthermore, polystyrene surfaces coated with A. pleuropneumoniae wild-type extracts, but not with capsule-mutant extracts, resisted S. aureus biofilm formation. Our findings suggest that the A. pleuropneumoniae serotype 5 capsule inhibits cell-to-cell and cell-to-surface interactions of other bacteria. A. pleuropneumoniae serotype 5 capsular polysaccharide is one of a growing number of bacterial polysaccharides that exhibit broad-spectrum, nonbiocidal antibiofilm activity. Future studies on these antibiofilm polysaccharides may uncover novel functions for bacterial polysaccharides in nature, and may lead to the development of new classes of antibiofilm agents for industrial and clinical applications.
Perry, Malcolm B.; Angen, Øystein; MacLean, Leann L.
Atypical Actinobacillus pleuropneumoniae serotype 13 strains present in North America are described here for the first time. Different from serotype 13 strains described in Europe, North America strains are biotype I and antigenically related to both, serotypes 13 and 10. Chemical and structural...
Chevallier, Bruno; Dugourd, Dominique; Tarasiuk, Kazimirez; Harel, Josée; Gottschalk, Marcelo; Kobisch, Marylène; Frey, Joachim
The genome size of Actinobacillus pleuropneumoniae was determined by pulsed field gel electrophoresis of AscI and ApaI digested chromosomal DNA. The genome size of the type strain 4074T (serotype 1) was determined to be 2404±40 kb. The chromosome sizes for the reference strains of the other serotypes range between 2.3 and 2.4 Mb. The restriction pattern profiles of AscI, ApaI and NheI digested chromosomes showed a high degree of polymorphism among the different serotype reference strains and ...
Angen, Øystein; Andreasen, M.; Nielsen, E.O.
The effect of a single or double dose of tulathromycin was evaluated in pigs carrying Actinobacillus pleuropneumoniae serotype 2 in their tonsils. Twenty-nine pigs from a reinfected specific pathogen-free-herd were selected from animals testing positive in an A pleuropneumoniae serotype 2-specific...
Fales, W H; Morehouse, L G; Mittal, K R; Bean-Knudsen, C; Nelson, S L; Kintner, L D; Turk, J R; Turk, M A; Brown, T P; Shaw, D P
The antimicrobial susceptibility of 73 Actinobacillus (Haemophilus) pleuropneumoniae isolates from swine in Missouri was determined with a microdilution minimal inhibitory concentration test system. Serotyping was accomplished by means of co-agglutination. Serotype 1 (39/73) and serotype 5 (30/73) were commonly found, whereas serotype 7 (4/73) was infrequently encountered. Most isolates (MIC90) were found susceptible to ampicillin (amoxicillin), cephalothin, penicillin, erythromycin, gentamicin, and kanamycin. Marked resistance was found with oxytetracycline, tylosin, and sulfadimethoxine. The data indicate that use of ampicillin (amoxicillin) or penicillin may correlate well with the favorable outcome of treatment.
Nielsen, R.; Andresen, Lars Ole; Plambeck, Tamara
Nine Danish Actinobacillus pleuropneumoniae biotype 1 isolates were shown by latex agglutination and indirect haemagglutination to possess capsular polysaccharide epitopes identical to those of serotype 2 strain 1536 (reference strain of serotype 2) and strain 4226 (Danish serotype 2 strain). Imm...... in the LPS of strains 1536 and 7317 were revealed. Since an antigenic determinant specific for the 9 isolates could not be demonstrated with the methods used, the strains are proposed to be designated K2:O7....
Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen
An indirect enzyme-linked immunoassay for serological surveillance of infection of pigs with Actinobacillus pleuropneumoniae (Ap) serotype 5 was developed. The antigen used was prepared from Ap serotype 5b strain L20. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis...
Ciro César Rossi
Full Text Available The OmlA protein is a virulence factor of Actinobacillus pleuropneumoniae, an important pathogen in pigs. The polymorphisms present in the omlA gene sequence of 15 reference serotypes of A. pleuropneumoniae and non-serotypable isolates were assessed to determine the possible evolutionary relationship among them and to validate the importance of this gene as a molecular marker for the characterization of this bacterium. Divergence among the 15 serotypes of A. pleuropneumoniae probably resulted initially from two major evolutionary events that led to subsequent differentiation into nine groups. This differentiation makes it possible to characterize most of the serotypes by using bionformatics, thereby avoiding problems with immunological cross-reactivity. A conserved α-helix common to all the serotypes was most likely involved in connecting the protein to the outer membrane and acting as a signal peptide. A previously unknown gene duplication was also identified and could contribute to the genetic variability that makes it difficult to serotype some isolates. Our data support the importance of the omlA gene in the biology of A. pleuropneumoniae and provide a new area of research into the OmlA protein.
Kokotovic, Branko; Angen, Øystein
Amplified fragment length polymorphism (AFLP) was evaluated as a method for genotypic characterization and subtyping within the bacterial species Actinobacillus pleuropneumoniae. A total of 155 isolates of A. pleuropneumoniae, representing the serotypic variation described to occur within...
Schou, Kirstine Klitgaard; Friis, Carsten; Angen, Øystein
Background Comparative analysis of gene expression among serotypes within a species can provide valuable information on important differences between related genomes. For the pig lung pathogen Actinobacillus pleuropneumoniae, 15 serotypes with a considerable variation in virulence potential...... and immunogenicity have been identified. This serotypic diversity can only partly be explained by amount of capsule and differences in the RTX toxin genes in their genomes. Iron acquisition in vivo is an important bacterial function and in pathogenic bacteria, iron-limitation is often a signal for the induction...... of virulence genes. We used a pan-genomic microarray to study the transcriptional response to iron restriction in vitro in six serotypes of A. pleuropneumoniae (1, 2, 3, 5b, 6, and 7), representing at least two levels of virulence. Results In total, 45 genes were significantly (p
Full Text Available Abstract Background Comparative analysis of gene expression among serotypes within a species can provide valuable information on important differences between related genomes. For the pig lung pathogen Actinobacillus pleuropneumoniae, 15 serotypes with a considerable variation in virulence potential and immunogenicity have been identified. This serotypic diversity can only partly be explained by amount of capsule and differences in the RTX toxin genes in their genomes. Iron acquisition in vivo is an important bacterial function and in pathogenic bacteria, iron-limitation is often a signal for the induction of virulence genes. We used a pan-genomic microarray to study the transcriptional response to iron restriction in vitro in six serotypes of A. pleuropneumoniae (1, 2, 3, 5b, 6, and 7, representing at least two levels of virulence. Results In total, 45 genes were significantly (p A. pleuropneumoniae was the up-regulation of a putative cirA-like siderophore in all six serotypes. Three genes, recently described in A. pleuropneumoniae as possibly coding for haemoglobin-haptoglobin binding proteins, displayed significant serotype related up-regulation to iron limitation. For all three genes, the expression appeared at its lowest in serotype 3, which is generally considered one of the least virulent serotypes of A. pleuropneumoniae. The three genes share homology with the hmbR haemoglobin receptor of Neisseria meningitidis, a possible virulence factor which contributes to bacterial survival in rats. Conclusions By comparative analysis of gene expression among 6 different serotypes of A. pleuropneumoniae we identified a common set of presumably essential core genes, involved in iron regulation. The results support and expand previous observations concerning the identification of new potential iron acquisition systems in A. pleuropneumoniae, showing that this bacterium has evolved several strategies for scavenging the limited iron resources of the
The aim of the present study was to examine the genomic relationship among 112 Actinobacillus pleuropneumoniae serotype 2 strains obtained throughout Europe and North America. HindIII ribotyping of the strains resulted in five ribotypes of high similarity (87-98%). Sequence analysis of the riboso......The aim of the present study was to examine the genomic relationship among 112 Actinobacillus pleuropneumoniae serotype 2 strains obtained throughout Europe and North America. HindIII ribotyping of the strains resulted in five ribotypes of high similarity (87-98%). Sequence analysis...... of the ribosomal intergenic region of strains representing each ribotype and each country showed no differences. A common ribotype was further characterized by PFGE of 12 strains representing all countries. The resultant five PFGE patterns of European strains showed a similarity of more than 91%, to which the two...
Kim, Boram; Hur, Jin; Lee, Ji Yeong; Choi, Yoonyoung; Lee, John Hwa
Actinobacillus pleuropneumoniae (APP) causes porcine pleuropneumonia (PP). Serotypes and antimicrobial resistance patterns in APP isolates from pigs in Korea were examined. Sixty-five APP isolates were genetically serotyped using standard and multiplex PCR (polymerase chain reaction). Antimicrobial susceptibilities were tested using the standardized disk-agar method. PCR was used to detect β-lactam, gentamicin and tetracycline-resistance genes. The random amplified polymorphic DNA (RAPD) patterns were determined by PCR. Korean pigs predominantly carried APP serotypes 1 and 5. Among 65 isolates, one isolate was sensitive to all 12 antimicrobials tested in this study. Sixty-two isolates was resistant to tetracycline and 53 isolates carried one or five genes including tet(B), tet(A), tet(H), tet(M)/tet(O), tet(C), tet(G) and/or tet(L)-1 markers. Among 64 strains, 9% and 26.6% were resistance to 10 and three or more antimicrobials, respectively. Thirteen different antimicrobial resistance patterns were observed and RAPD analysis revealed a separation of the isolates into two clusters: cluster II (6 strains resistant to 10 antimicrobials) and cluster I (the other 59 strains). Results show that APP serotypes 1 and 5 are the most common in Korea, and multi-drug resistant strains are prevalent. RAPD analysis demonstrated that six isolates resistant to 10 antimicrobials belonged to the same cluster.
Angen, Øystein; Jensen, J.; Lavritsen, D. T.
Sequence detection by the 5' nuclease TaqMan assay uses online detection of internal fluorogenic probes in closed PCR tubes. Primers and probe were chosen from a part of the omlA gene common to all serotypes of Actinobacillus pleuropneumoniae, which gave an amplicon of 92 bp, The test was evaluat...
Gutiérrez, C B; Rodríguez Barbosa, J I; Tascón, R I; Costa, L; Riera, P; Rodríguez Ferri, E F
Seventy-one isolates of Actinobacillus pleuropneumoniae isolated from the lungs of pigs in outbreaks of pleuropneumonia in Spain were serotyped by indirect haemagglutination. Serotype 4 (42.2 per cent), serotype 7 (22.5 per cent) and serotype 2 (12.8 per cent) were predominant, whereas serotypes 1, 3, 6, 8, 9, 12 and untypable isolates were present only in small numbers. Serotypes 1, 2, 4 and 7 originated mainly from cases of acute pleuropneumonia, whereas serotypes 3, 6, 8, 9 and 12 were associated with chronically infected herds. The susceptibility of the isolates to 20 antimicrobial agents was determined by agar disc diffusion. Most were susceptible to cefuroxime, cefaclor, cefazolin, kanamycin, tobramycin, gentamicin, oxolinic acid, ciprofloxacin, enoxacin, thiamphenicol, colistin and trimethoprim/sulphamethoxazole. Marked resistance was found with amoxicillin, ticarcillin, oxytetracycline, doxycycline and metronidazole. Rifampicin, fosfomycin and tiamulin were the agents most effective against the isolates tested.
Andresen, Lars Ole; Klausen, Joan; Barfod, Kristen
and from herds declared free of infection with Ap. The Ap serotype 12 blocking ELISA showed a herd sensitivity of 0.77 (95% confidence interval, 0.62-0.88) and a herd specificity of 1.00 (0.95-1.00) with a cut-off value at 40% relative absorbance or 60% inhibition. The assay may be used advantageously......The objective was to develop a blocking enzyme-linked immunosorbent assay (ELISA) for detection of antibodies to Actinobacillus pleuropneumoniae (Ap) serotype 12 in pig serum. Lipopolysaccharide (LPS) from Ap serotype 12 was purified and used as antigen in the assay. Antibodies to the LPS antigen...... in samples of pig serum were detected by inhibition of the binding of polyclonal rabbit antibodies raised against Ap serotype 12. The assay was evaluated against sera from experimentally infected pigs, from pig herds naturally infected with Ap and from herds declared free of Ap serotypc 12 infection...
Kristensen, C.S.; Angen, Øystein; Andreasen, M.
Airborne transmission of Actinobacillus pleuropneumoniae was studied as the percentage of air needed to establish airborne transmission from an infected pig unit into a neighbouring non-infected pig unit. The experiment was carried out in two containers constructed as pig units, placed 1 m apart...... and connected by pipes. By manipulating the air pressure in the two units, the amount of ventilation air transferred from the infected pigs (unit A) to the non-infected pigs (unit B) was controlled and measured. In three experiments, between 48 and 50 specific pathogen free-pigs were randomly assigned to each...... of the two units. In unit A, five pigs (experiment 1) or eight pigs (experiments 2 and 3) were inoculated with A. pleuropneumoniae serotype 2. In experiments 1 and 3, 10% of the air was transferred from unit A to B; in experiment 2, 70% of the air was transferred. In the non-infected unit (B), 36...
Differentiation of Actinobacillus pleuropneumoniae strains by sequence analysis of 16S rDNA and ribosomal intergenic regions, and development of a species specific oligonucleotide for in situ detection
Fussing, Vivian; Paster, Bruce J.; Dewhirst, Floyd E.
. The larger RIS's were different between the 3 species tested. The sequence of the 16S ribosomal gene was determined for 8 serotypes of A. pleuropneumoniae. These sequences showed only minor base differences, indicating a close genetic relatedness of these serotypes within the species. An oligonucleotide DNA...... probe designed from the 16S rRNA gene sequence of A. pleuropneumoniae was specific for all strains of the target species and did not cross react with A. lignieresii, the closest known relative of A. pleuropneumoniae. This species-specific DNA probe labeled with fluorescein was used for in situ......The aims of this study were to characterize and determine intraspecies and interspecies relatedness of Actinobacillus pleuropneumoniae to Actinobacillus lignieresii and Actinobacillus suis by sequence analysis of the ribosomal operon and to find a species-specific area for in situ detection of A...
Jensen, Tim Kåre; Boye, Mette; Hagedorn-Olsen, T.
Necrotizing osteomyelitis and fibrinopurulent arthritis with isolation of Actinobacillus pleuropneumoniae serotype 2 is reported in two pigs from a herd with lameness and mild coughing problems among 8 to 12-week-old pigs. Application of fluorescent in situ hybridization targeting 16S ribosomal R......, in joints with arthritis, and in bone necroses including lysis of growth plate and suppurative inflammation in the adjacent trabecular metaphysis, thus demonstrating that well-known infections manifest new, unusual lesions....
Full Text Available MeCab user dictionary for science technology term Actinobacillus pleuropneumoniae 名...詞 一般 * * * * Actinobacillus pleuropneumoniae ... MeSH D016977 200906089064706214 C LS07 UNKNOWN_2 Actinobacillus pleuropneumoniae
Padronização de três ELISAs polivalentes com lipopolissacarídeos de cadeia longa dos sorotipos 1 e 5, 2, 3 e 7 ou 10 e 12 de Actinobacillus pleuropneumoniae Standardization of three polyvalent ELISA based on long chain lipopolysaccharides of serotypes 1 and 5, 2, 3 and 7, or 10 and 12 of Actinobacillus pleuropneumoniae
Full Text Available Três ELISAs polivalentes baseados em lipopolissacarídeos de cadeia longa (LPS-CL foram estabelecidos para detectar anticorpos para todos os sorotipos prevalentes de Actinobacillus pleuropneumoniae. Foram testadas amostras provenientes do banco de soros de suínos experimentalmente inoculados com todos os sorotipos de A. pleuropneumoniae. Os ELISAs foram sensíveis à detecção de anticorpos contra todos os LPS-CL. Foram observadas reações cruzadas no ELISA polivalente produzido com os sorotipos 1 e 5, com anti-soros específicos para os sorotipos 9 e 11, pois os sorotipos 1, 9 e 11 apresentaram antígenos somáticos comuns. No polivalente com os sorotipos 2, 3 e 7, observaram-se reações com anti-soros dos sorotipos 4, 6 e 8, devido à presença de antígenos somáticos entre os sorotipos 3, 6 e 8 e entre os sorotipos 4 e 7. Amostras de soros de animais infectados com Mycoplasma hyopneumoniae, Mycoplasma flocculare e Haemophilus parasuis, agentes que acometem o sistema respiratório dos suínos, não apresentaram reações cruzadas com os antígenos baseados em LPS-CL.Three polyvalent ELISA based on long chain lipopolysaccharides (LC-LPS were established to detect all prevalent serotypes of Actinobacillus pleuropneumoniae. Samples from a serum bank of experimentally inoculated animals with all serotypes of A. pleuropneumoniae were tested. Antibodies specific to LC-LPS of each serotype were detected. Cross-reactions were observed in the polyvalent ELISA produced with serotypes 1 and 5, with specific antisera to serotypes 9 and 11 due to common somatic antigens presence in serotypes 1, 9, and 11. In the polyvalent with serotypes 2, 3 and 7 reactions were observed with antisera of serotypes 4, 6, and 8, due to the presence of somatic antigens in serotypes 3, 6, and 8 and serotypes 4 and 7. Experimentally infected animals with respiratory agents of swine Mycoplasma hyopneumoniae, Mycoplasma flocculare, and Haemophilus parasuis did not present
Full Text Available Abstract Background Protection of pigs by vaccination against Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is hampered by the presence of 15 different serotypes. A DIVA subunit vaccine comprised of detergent-released proteins from A. pleuropneumoniae serotypes 1, 2 and 5 has been developed and shown to protect pigs from clinical symptoms upon homologous and heterologous challenge. This vaccine has not been characterized in-depth so far. Thus we performed i mass spectrometry in order to identify the exact protein content of the vaccine and ii cross-serotype 2-D immunoblotting in order to discover cross-reactive antigens. By these approaches we expected to gain results enabling us to argue about the reasons for the efficacy of the analyzed vaccine. Results We identified 75 different proteins in the vaccine. Using the PSORTb algorithm these proteins were classified according to their cellular localization. Highly enriched proteins are outer membrane-associated lipoproteins like OmlA and TbpB, integral outer membrane proteins like FrpB, TbpA, OmpA1, OmpA2, HgbA and OmpP2, and secreted Apx toxins. The subunit vaccine also contained large amounts of the ApxIVA toxin so far thought to be expressed only during infection. Applying two-dimensional difference gel electrophoresis (2-D DIGE we showed different isoforms and variations in expression levels of several proteins among the strains used for vaccine production. For detection of cross-reactive antigens we used detergent released proteins of serotype 7. Sera of pigs vaccinated with the detergent-released proteins of serotypes 1, 2, and 5 detected seven different proteins of serotype 7, and convalescent sera of pigs surviving experimental infection with serotype 7 reacted with 13 different proteins of the detergent-released proteins of A. pleuropneumoniae serotypes 1, 2, and 5. Conclusions A detergent extraction-based subunit vaccine of A. pleuropneumoniae was
Grøndahl-Hansen, Jan; Barfod, Kristen; Klausen, Joan
The objective was to develop an enzyme-linked immunosorbent assay (ELISA) for simultaneous detection of antibodies against Actinobacillus pleuropneumoniae (Ap) serotypes 2, 6 and 12. The assay was designated MIX-ELISA. Lipopolysaccharide (LPS) from Ap serotypes 2, 6 and 12 was purified using hot...... of the assay indicate that screening of herds for Ap infection can be performed using this ELISA. Efficient serological surveillance can be achieved by using such mixed antigen ELISAs coated with size-selected LPS-antigens from the most prevalent serotypes....... phenol-water extraction followed by fractionation by size-exclusion chromatography. A mixture of fractions containing molecules with molecular weight above 50 kDa from all three serotypes was used as antigen. The MIX-ELISA was evaluated with sera from pigs experimentally infected with the serotypes 1, 2...
Yoshimura, H; Takagi, M; Ishimura, M; Endoh, Y S
Sixteen antimicrobial agents were tested for their activity against 68 isolates of Actinobacillus pleuropneumoniae by determining the minimum inhibitory concentrations (MICs). Ceftiofur and the fluoroquinolones danofloxacin and enrofloxacin were the most active compounds, with a MIC for 90% of the isolates (MIC90) of (0.05 microg/ml. The MIC90 values of benzylpenicillin, amoxicillin and aspoxicillin were 0.78 units/ml, 0.39 microg/ml and colistin and tiamulin. Of these, spectinomycin was the least active, with a MIC50 of 25 microg/ml, followed by tiamulin, with a MIC50 of 6.25 microg/ml. Of the 68 isolates tested, 49 (72.0%) were of serotype 2; 14 (20.5%) were of serotype 1; 2 each (3.0%) were of serotypes 5 and 6; and one was of serotype 7. Of the isolates, 23 (33.8%) were resistant to one or more of the major antibiotics. Antibiotic resistance was found only infrequently among serotype 2, with 5 (10.2%) of 49 isolates being resistant to chloramphenicol and/or oxytetracycline, while it occurred in 18 (94.7%) of the 19 isolates of other serotypes.
Nielsen, Ragnhild; van den Bosch, Johannes F.; Plambeck, Tamara
The reference strains of the 12 serotypes of Actinobacillus pleuropneumoniae express one or two of three different RTX exotoxins designated Apr I, Apr II and Apr III. The toxins are important virulence factors. In the present study, ELISAs with purified Apr I, Apr II and Apr III, respectively...... of exotoxin is not revealed serologically in the ELISA test....
Full Text Available Abstract Background Actinobacillus pleuropneumoniae is the etiological agent of porcine pleuropneumonia, a respiratory disease which causes great economic losses worldwide. Many virulence factors are involved in the pathogenesis, namely capsular polysaccharides, RTX toxins, LPS and many iron acquisition systems. In order to identify genes that are expressed in vivo during a natural infection, we undertook transcript profiling experiments with an A. pleuropneumoniae DNA microarray, after recovery of bacterial mRNAs from serotype 5b-infected porcine lungs. AppChip2 contains 2033 PCR amplicons based on the genomic sequence of App serotype 5b strain L20, representing more than 95% of ORFs greater than 160 bp in length. Results Transcriptional profiling of A. pleuropneumoniae recovered from the lung of a pig suffering from a natural infection or following growth of the bacterial isolate in BHI medium was performed. An RNA extraction protocol combining beadbeating and hot-acid-phenol was developed in order to maximize bacterial mRNA yields and quality following total RNA extraction from lung lesions. Nearly all A. pleuropneumoniae transcripts could be detected on our microarrays, and 150 genes were deemed differentially expressed in vivo during the acute phase of the infection. Our results indicate that, for example, gene apxIVA from an operon coding for RTX toxin ApxIV is highly up-regulated in vivo, and that two genes from the operon coding for type IV fimbriae (APL_0878 and APL_0879 were also up-regulated. These transcriptional profiling data, combined with previous comparative genomic hybridizations performed by our group, revealed that 66 out of the 72 up-regulated genes are conserved amongst all serotypes and that 3 of them code for products that are predicted outer membrane proteins (genes irp and APL_0959, predicted to code for a TonB-dependent receptor and a filamentous hemagglutinin/adhesin respectively or lipoproteins (gene APL_0920. Only 4
Ito, Hiroya; Takahashi, Sayaka; Asai, Tetsuo; Tamura, Yutaka; Yamamoto, Koshi
An atypical urease-negative mutant of Actinobacillus pleuropneumoniae serovar 2 was isolated in Japan. Nucleotide sequence analysis of the urease gene cluster revealed that the insertion of a short DNA sequence into the cbiM gene was responsible for the urease-negative activity of the mutant. Veterinary diagnostic laboratories should be watchful for the presence of aberrant urease-negative A. pleuropneumoniae isolates.
Andreasen, Margit; Mousing, Jan; Thomsen, Lars Krogsgård
approximately 4 weeks of age), and sera were analyzed for antibodies to Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae serotypes 2, 5-7 and 12. Mixed analysis of covariance analyzed the relationship between the average daily weight gain and a categorical variable defining seroconversion as none...... most pigs included in the study were subclinically infected, or because a temporary negative influence of the infections is hidden due to an increased growth in the period following infection. In conclusion. at least in these eight herds, seroresponses to M. hyopneumoniae and A. pleuropneumoniae could...
Brogaard, Louise; Schou, Kirstine Klitgaard; Heegaard, Peter M. H.
Background: Actinobacillus pleuropneumoniae causes pleuropneumonia in pigs, a disease which is associated with high morbidity and mortality, as well as impaired animal welfare. To obtain in-depth understanding of this infection, the interplay between virulence factors of the pathogen and defense ...
Full Text Available Abstract Background The prevalence of pleurisies recorded at slaughter is increasing in Sweden, and acute outbreaks of actinobacillosis that require antimicrobial treatments have become more frequent. As an increased use of antimicrobials may result in the development of antimicrobial resistance it is essential to develop alternative measures to control the disease. Vaccinations present an appealing alternative to antimicrobial treatments. The aim of this work was to evaluate the potential of two different vaccination strategies in a specialized fattening herd affected by actinobacillosis. Methods The study was conducted in a specialized fattening herd employing age segregated rearing in eight units. The herd suffered from infections caused by Actinobacillus pleuropneumoniae serotype 2, confirmed by necropsy and serology. The study included 54 batches of pigs grouped into five periods. Batches of pigs of the second period were vaccinated against actinobacillosis twice, and pigs in the fourth period were vaccinated three times. Batches of pigs of the first, third and fifth period were not vaccinated. Concentrations of serum antibodies to A. pleuropneumoniae and serum amyloid A (SAA were analysed and production data were recorded. Results Despite vaccinating, medical treatments were required to reduce the impact of the disease. The mean incidence of individual treatments for respiratory diseases during the rearing period ranged from 0 to 4.7 ± 1.8%, and was greatest during the triple vaccination period (period IV; p A. pleuropneumoniae serotype 2 in the absence of a SAA-response. The prevalence of pleuritis decreased from 25.4 ± 6.5% in the first period to 5.0 ± 3.7% in the fifth period (p Conclusions The vaccine did not effectively prevent clinical expression of A. pleuropneumoniae infections, but seroconversion to A. pleuropneumoniae in the absence of a SAA-response in a large number pigs indicated that the vaccine had activated the immune
Gutiérrez, C B; Píriz, S; Vadillo, S; Rodríguez Ferri, E F
Minimal inhibitory concentration of 42 antimicrobial agents was determined against 57 field strains of Actinobacillus pleuropneumoniae isolated from pigs in Spain. Penicillins, aminoglycosides, and tetracyclines had irregular activity; ticarcillin, tobramycin, and doxycycline were the most active of each group, respectively. Macrolides, vancomycin, dapsone, and tiamulin, to which strains had high rate of resistance, were almost ineffective. Thiamphenicol, colistin, rifampin, fosfomycin, mupirocin, and metronidazole had good activity, with resistance ranging between 0 and 8.8%. Finally, cephalosporins (except cephalexin) and quinolones (especially ciprofloxacin, enrofloxacin, and sparfloxacin) were the most active antibiotics against A pleuropneumoniae.
Full Text Available Cytotoxins produced by Actinobacillus pleuropneumoniae (App suggested to be the most important pathogenic and virulent factors for this organism. However, the mechanisms on how the cytotoxins contribute to the disease process remain unclear. The purpose of this study is to investigate the effect of the cytotoxins on the oxidative-burst metabolism of porcine neutrophils. In this study, neutrophils were firstly loaded with an oxidative probe dichlorofluorescin diacetate (DCFHDA then expose to cytotoxins. Cells producing oxygen radicals emitted fluorescence and its intensity was measured with a FACScan flow cytometer. All cytotoxins derived from either App serotypes producing ApxI and ApxII, App serotypes producing ApxII only, or App serotypes producing ApxII and ApxIII were capable of stimulating neutrophils for oxygen-radical generation. However, compared with phorbol myristate acetate (PMA, App cytotoxins were much weaker as stimulants for oxygen radicals. In addition, Apx preparation stimulated an oxidative-burst metabolism of neutrophils at a low, narrow range of Apx doses. At higher doses, the toxins inhibit the oxidative burst metabolism. The effects of cytotoxins produced by App during infection on recruited neutrophils into the lungs are assumed to be comparable to those observed in this in vitro study. Neutrophils, and other host cells, adjacent to the bacteria become lysis due to high toxin concentration, whereas those at some distance to the bacteria produce oxygen radicals which in turn cause tissue damage or necrosis.
Nielsen, R.; Andresen, Lars Ole; Plambeck, Tamara
Eight Actinobacillus pleuropneumoniae biotype 2 strains were isolated in pure culture from lungs of pigs originating from two Danish herds with growing and finishing pigs. The antigenic properties were studied by indirect haemagglutination (IHA) and immunodiffusion (ID) tests using soluble surface...
Subashchandrabose, Sargurunathan; LeVeque, Rhiannon M.; Wagner, Trevor K.; Kirkwood, Roy N.; Kiupel, Matti; Mulks, Martha H.
In Actinobacillus pleuropneumoniae, which causes porcine pleuropneumonia, ilvI was identified as an in vivo-induced (ivi) gene and encodes the enzyme acetohydroxyacid synthase (AHAS) required for branched-chain amino acid (BCAA) biosynthesis. ilvI and 7 of 32 additional ivi promoters were upregulated in vitro when grown in chemically defined medium (CDM) lacking BCAA. Based on these observations, we hypothesized that BCAA would be found at limiting concentrations in pulmonary secretions and t...
Kiorpes, A L; Bäckström, L R; Collins, M T; Kruse, G O
These experiments tested the hypothesis that long-acting oxytetracycline (oxytetracycline-LA) was more effective than regular oxytetracycline in preventing porcine pleuropneumonia when administered either 24 or 48 h prior to experimental challenge with virulent strains of Actinobacillus pleuropneumoniae. Two experiments (1 and 2) were conducted using growing pigs (average weight 12-15 kg). Antibiotic treatments were administered once intramuscularly at 20 mg/kg body weight; controls received ...
MacInnes Janet I
Full Text Available Abstract Background Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH were used to estimate whole genomic diversity of representative Actinobacillus pleuropneumoniae strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines. Results Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 A. pleuropneumoniae L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements. Conclusion Although A. pleuropneumoniae strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.
Zhou, L.; Jones, S.C.P.; Angen, Øystein
, but the method has liminations, for example, cross-reactions between serotypes 3, 6, and 8. This study describes the development of a serotype 3-specific PCR, based on the capsule locus, which can be used in a multiplex format with the organism's specific gene apxIV. The PCR test was evaluated on 266 strains...
Vigre, Håkan; Angen, Øystein; Barfod, K.
The objectives of this study were to elucidate at which age tonsillar colonisation by Actinobacillus pleuropneumoniae occurs in pigs and relate this occurrence to the presence of colostral antibodies to A. pleuropneumoniae. The infection patterns were studied in an isolated cohort of pigs, which...... consisted of the offspring from five sows originating from a conventional pig herd. The sows were transferred to isolated research facilities before farrowing. A. pleuropneumoniae was detected on the tonsils of all sows. After a nursing period of 3 weeks, the pigs were weaned and reared isolated from other...
Reação em Cadeia da Polimerase (PCR baseada no gene cpx para detecção de Actinobacillus pleuropneumoniae em suínos natural e experimentalmente infectados Polymerase Chain Reaction (PCR based on the cpx gene for detection of Actinobacillus pleuropneumoniae in natural and experimentally infected pigs
Karina Koerich de Souza
Full Text Available A pleuropneumonia suína é uma das mais importantes doenças respiratórias dos suínos, estando presente em todos os países produtores. Para o controle e o monitoramento da pleuropneumonia, é necessário o desenvolvimento de métodos rápidos e acurados de diagnóstico. Com o objetivo de validar a técnica da PCR, baseada no gene cpx de Actinobacillus pleuropneumoniae, em suínos sabidamente positivos, primeiramente foi realizada inoculação experimental com amostras de A. pleuropneumoniae sorotipo 5B e coletadas amostras por meio de suabe de tonsila, biópsia de tonsila e sangue para realização da técnica de PCR, isolamento bacteriológico e teste de ELISA, respectivamente. Posteriormente, estas técnicas foram aplicadas em suínos naturalmente infectados, em três rebanhos com diferentes situações sanitárias quanto à apresentação clínica da doença. De cada rebanho, foram analisados cinco grupos de suínos com idades diferentes, sendo coletado de cada animal biópsia de tonsila para isolamento bacteriológico e PCR e sangue para determinação do perfil sorológico. Os resultados obtidos na inoculação experimental confirmaram que, mesmo com o estabelecimento da infecção comprovada pelo isolamento bacteriológico, após o período de 45 dias, não foi possível detectar o agente pela técnica de PCR. Em animais naturalmente infectados, a técnica de PCR apresentou maior sensibilidade quando comparado com o isolamento. A associação entre PCR e ELISA demonstrou ser uma boa alternativa para definir a situação sanitária do rebanho quanto à infecção por A. pleuropneumoniae.Swine pleuropneumonia is one of the most important pig respiratory diseases and has been found in all producer countries. For control and monitoring of pleuropneumonia, it is necessary the development of fast and specific methods of diagnosis. To validate PCR based on the cpx gene of Actinobacillus pleuropneumoniae in positive pigs, an experimental
Hedegaard, Jakob; Skovgaard, Kerstin; Mortensen, Shila
Background: The bacterium Actinobacillus pleuropneumoniae is responsible for porcine pleuropneumonia, a widespread, highly contagious and often fatal respiratory disease of pigs. The general porcine innate immune response after A. pleuropneumoniae infection is still not clarified. The objective...... lymph node tissue were hybridised to an expanded version of the porcine microarray with 26879 unique PCR products. Results: A total of 357 genes differed significantly in expression between infected and non-infected lung tissue, 713 genes differed in expression in liver tissue from infected versus non-infected...... animals and 130 genes differed in expression in tracheobronchial lymph node tissue from infected versus non-infected animals. Among these genes, several have previously been described to be part of a general host response to infections encoding immune response related proteins. In inflamed lung tissue...
Shin, Min-Kyoung; Jung, Myung Hwan; Lee, Won-Jung; Choi, Pil Son; Jang, Yong-Suk
Corn, one of the most important forage crops worldwide, has proven to be a useful expression vehicle due to the availability of established transformation procedures for this well-studied plant. The exotoxin Apx, a major virulence factor, is recognized as a common antigen of Actinobacillus (A.) pleuropneumoniae, the causative agent of porcine pleuropneumonia. In this study, a cholera toxin B (CTB)-ApxIIA#5 fusion protein and full-size ApxIIA expressed in corn seed, as a subunit vaccine candidate, were observed to induce Apx-specific immune responses in mice. These results suggest that transgenic corn-derived ApxIIA and CTB-ApxIIA#5 proteins are potential vaccine candidates against A. pleuropneumoniae infection. PMID:22122907
Bossé, Janine T; Li, Yanwen; Sárközi, Rita; Gottschalk, Marcelo; Angen, Øystein; Nedbalcova, Katerina; Rycroft, Andrew N; Fodor, László; Langford, Paul R
Actinobacillus pleuropneumoniae causes pleuropneumonia, an economically significant lung disease of pigs. Recently, isolates of A. pleuropneumoniae that were serologically distinct from the previously characterized 15 serovars were described, and a proposal was put forward that they comprised a new serovar, serovar 16. Here we used whole-genome sequencing of the proposed serovar 16 reference strain A-85/14 to confirm the presence of a unique capsular polysaccharide biosynthetic locus. For molecular diagnostics, primers were designed from the capsule locus of strain A-85/14, and a PCR was formulated that differentiated serovar 16 isolates from all 15 known serovars and other common respiratory pathogenic/commensal bacteria of pigs. Analysis of the capsule locus of strain A-85/14 combined with the previous serological data show the existence of a sixteenth serovar-designated serovar 16-of A. pleuropneumoniae . Copyright © 2017 Bossé et al.
Abdul G Lone
Full Text Available BACKGROUND: Actinobacillus pleuropneumoniae, the causative agent of porcine contagious pleuropneumonia, is an important pathogen of swine throughout the world. It must rapidly overcome the innate pulmonary immune defenses of the pig to cause disease. To better understand this process, the objective of this study was to identify genes that are differentially expressed in a medium that mimics the lung environment early in the infection process. METHODS AND PRINCIPAL FINDINGS: Since bronchoalveolar lavage fluid (BALF contains innate immune and other components found in the lungs, we examined gene expression of a virulent serovar 1 strain of A. pleuropneumoniae after a 30 min exposure to BALF, using DNA microarrays and real-time PCR. The functional classes of genes found to be up-regulated most often in BALF were those encoding proteins involved in energy metabolism, especially anaerobic metabolism, and in cell envelope, DNA, and protein biosynthesis. Transcription of a number of known virulence genes including apxIVA and the gene for SapF, a protein which is involved in resistance to antimicrobial peptides, was also up-regulated in BALF. Seventy-nine percent of the genes that were up-regulated in BALF encoded a known protein product, and of these, 44% had been reported to be either expressed in vivo and/or involved in virulence. CONCLUSIONS: The results of this study suggest that in early stages of infection, A. pleuropneumoniae may modulate expression of genes involved in anaerobic energy generation and in the synthesis of proteins involved in cell wall biogenesis, as well as established virulence factors. Given that many of these genes are thought to be expressed in vivo or involved in virulence, incubation in BALF appears, at least partially, to simulate in vivo conditions and may provide a useful medium for the discovery of novel vaccine or therapeutic targets.
Full Text Available Actinobacillus pleuropneumoniae is the pathogen of porcine contagious pleuropneumoniae, a highly contagious respiratory disease of swine. Although the genome of A. pleuropneumoniae was sequenced several years ago, limited information is available on the genome-wide transcriptional analysis to accurately annotate the gene structures and regulatory elements. High-throughput RNA sequencing (RNA-seq has been applied to study the transcriptional landscape of bacteria, which can efficiently and accurately identify gene expression regions and unknown transcriptional units, especially small non-coding RNAs (sRNAs, UTRs and regulatory regions. The aim of this study is to comprehensively analyze the transcriptome of A. pleuropneumoniae by RNA-seq in order to improve the existing genome annotation and promote our understanding of A. pleuropneumoniae gene structures and RNA-based regulation. In this study, we utilized RNA-seq to construct a single nucleotide resolution transcriptome map of A. pleuropneumoniae. More than 3.8 million high-quality reads (average length ~90 bp from a cDNA library were generated and aligned to the reference genome. We identified 32 open reading frames encoding novel proteins that were mis-annotated in the previous genome annotations. The start sites for 35 genes based on the current genome annotation were corrected. Furthermore, 51 sRNAs in the A. pleuropneumoniae genome were discovered, of which 40 sRNAs were never reported in previous studies. The transcriptome map also enabled visualization of 5'- and 3'-UTR regions, in which contained 11 sRNAs. In addition, 351 operons covering 1230 genes throughout the whole genome were identified. The RNA-Seq based transcriptome map validated annotated genes and corrected annotations of open reading frames in the genome, and led to the identification of many functional elements (e.g. regions encoding novel proteins, non-coding sRNAs and operon structures. The transcriptional units
Janine T Bosse
Full Text Available ICEApl1 was identified in the whole genome sequence of MIDG2331, a tetracycline-resistant (MIC = 8 mg/L serovar 8 clinical isolate of Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia. PCR amplification of virB4, one of the core genes involved in conjugation, was used to identify other A. pleuropneumoniae isolates potentially carrying ICEApl1. MICs for tetracycline were determined for virB4 positive isolates, and shotgun whole genome sequence analysis was used to confirm presence of the complete ICEApl1. The sequence of ICEApl1 is 56083 bp long and contains 67 genes including a Tn10 element encoding tetracycline resistance. Comparative sequence analysis was performed with similar integrative conjugative elements (ICEs found in other members of the Pasteurellaceae. ICEApl1 is most similar to the 59393 bp ICEHin1056, from Haemophilus influenzae strain 1056. Although initially identified only in serovar 8 isolates of A. pleuropneumoniae (31 from the UK and 1 from Cyprus, conjugal transfer of ICEApl1 to representative isolates of other serovars was confirmed. All isolates carrying ICEApl1 had a MIC for tetracycline of 8 mg/L. This is, to our knowledge, the first description of an ICE in A. pleuropneumoniae, and the first report of a member of the ICEHin1056 subfamily in a non-human pathogen. ICEApl1 confers resistance to tetracycline, currently one of the more commonly used antibiotics for treatment and control of porcine pleuropneumonia.
Xiao, Longwen; Zhou, Liang; Sun, Changjiang; Feng, Xin; Du, ChongTao; Gao, Yu; Ji, Qun; Yang, Shuxin; Wang, Yu; Han, Wenyu; Langford, P R; Lei, Liancheng
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, and adherence to host cells is a key step in the pathogenic process. Although trimeric autotransporter adhesins (TAAs) were identified in many pathogenic bacteria in recent years, none in A. pleuropneumoniae have been characterized. In this study, we identified a TAA from A. pleuropneumoniae, Apa, and characterized the contribution of its amino acid residues to the adhesion process. Sequence analysis of the C-terminal amino acid residues of Apa revealed the presence of a putative translocator domain and six conserved HsfBD1-like or HsfBD2-like binding domains. Western blot analysis revealed that the 126 C-terminal amino acids of Apa could form trimeric molecules. By confocal laser scanning microscopy, one of these six domains (ApaBD3) was determined to mediate adherence to epithelial cells. Adherence assays and adherence inhibition assays using a recombinant E. coli- ApaBD3 strain which expressed ApaBD3 on the surface of E. coli confirmed that this domain was responsible for the adhesion activity. Moreover, cellular enzyme-linked immunosorbent assays demonstrated that ApaBD3 mediated high-level adherence to epithelial cell lines. Intriguingly, autoagglutination was observed with the E. coli- ApaBD3 strain, and this phenomenon was dependent upon the association of the expressed ApaBD3 with the C-terminal translocator domain. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Full Text Available BACKGROUND: Gene expression profiles of bacteria in their natural hosts can provide novel insight into the host-pathogen interactions and molecular determinants of bacterial infections. In the present study, the transcriptional profile of the porcine lung pathogen Actinobacillus pleuropneumoniae was monitored during the acute phase of infection in its natural host. METHODOLOGY/PRINCIPAL FINDINGS: Bacterial expression profiles of A. pleuropneumoniae isolated from lung lesions of 25 infected pigs were compared in samples taken 6, 12, 24 and 48 hours post experimental challenge. Within 6 hours, focal, fibrino hemorrhagic lesions could be observed in the pig lungs, indicating that A. pleuropneumoniae had managed to establish itself successfully in the host. We identified 237 differentially regulated genes likely to encode functions required by the bacteria for colonization and survival in the host. This group was dominated by genes involved in various aspects of energy metabolism, especially anaerobic respiration and carbohydrate metabolism. Remodeling of the bacterial envelope and modifications of posttranslational processing of proteins also appeared to be of importance during early infection. The results suggested that A. pleuropneumoniae is using various strategies to increase its fitness, such as applying Na+ pumps as an alternative way of gaining energy. Furthermore, the transcriptional data provided potential clues as to how A. pleuropneumoniae is able to circumvent host immune factors and survive within the hostile environment of host macrophages. This persistence within macrophages may be related to urease activity, mobilization of various stress responses and active evasion of the host defenses by cell surface sialylation. CONCLUSIONS/SIGNIFICANCE: The data presented here highlight the importance of metabolic adjustments to host conditions as virulence factors of infecting microorganisms and help to provide insight into the mechanisms
Bossé, Janine T; Li, Yanwen; Walker, Stephanie; Atherton, Tom; Fernandez Crespo, Roberto; Williamson, Susanna M; Rogers, Jon; Chaudhuri, Roy R; Weinert, Lucy A; Oshota, Olusegun; Holden, Matt T G; Maskell, Duncan J; Tucker, Alexander W; Wren, Brendan W; Rycroft, Andrew N; Langford, Paul R
The objective of this study was to determine the distribution and genetic basis of trimethoprim resistance in Actinobacillus pleuropneumoniae isolates from pigs in England. Clinical isolates collected between 1998 and 2011 were tested for resistance to trimethoprim and sulphonamide. The genetic basis of trimethoprim resistance was determined by shotgun WGS analysis and the subsequent isolation and sequencing of plasmids. A total of 16 (out of 106) A. pleuropneumoniae isolates were resistant to both trimethoprim (MIC >32 mg/L) and sulfisoxazole (MIC ≥256 mg/L), and a further 32 were resistant only to sulfisoxazole (MIC ≥256 mg/L). Genome sequence data for the trimethoprim-resistant isolates revealed the presence of the dfrA14 dihydrofolate reductase gene. The distribution of plasmid sequences in multiple contigs suggested the presence of two distinct dfrA14-containing plasmids in different isolates, which was confirmed by plasmid isolation and sequencing. Both plasmids encoded mobilization genes, the sulphonamide resistance gene sul2, as well as dfrA14 inserted into strA, a streptomycin-resistance-associated gene, although the gene order differed between the two plasmids. One of the plasmids further encoded the strB streptomycin-resistance-associated gene. This is the first description of mobilizable plasmids conferring trimethoprim resistance in A. pleuropneumoniae and, to our knowledge, the first report of dfrA14 in any member of the Pasteurellaceae. The identification of dfrA14 conferring trimethoprim resistance in A. pleuropneumoniae isolates will facilitate PCR screens for resistance to this important antimicrobial. © The Author 2015. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.
Full Text Available Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, a significant disease that causes serious economic losses to the swine industry worldwide. Persistent infections caused by bacterial biofilms are recalcitrant to treat because of the particular drug resistance of biofilm-dwelling cells. TolC, a key component of multidrug efflux pumps, are responsible for multidrug resistance in many Gram-negative bacteria. In this study, we identified two TolC-like proteins, TolC1 and TolC2, in A. pleuropneumoniae. Deletion of tolC1, but not tolC2, caused a significant reduction in biofilm formation, as well as increased drug sensitivity of both planktonic and biofilm cells. The genetic-complementation of the tolC1 mutation restored the competent biofilm and drug resistance. Besides, biofilm formation was inhibited and drug sensitivity was increased by the addition of phenylalanine-arginine beta-naphthylamide (PAβN, a well-known efflux pump inhibitor (EPI, suggesting a role for EPI in antibacterial strategies towards drug tolerance of A. pleuropneumoniae. Taken together, TolC1 is required for biofilm formation and is a part of the multidrug resistance machinery of both planktonic and biofilm cells, which could supplement therapeutic strategies for resistant bacteria and biofilm-related infections of A. pleuropneumoniae clinical isolate SC1516.
Lauritzen, B.; Lykkesfeldt, J.; Skaanild, M.T.
Biomarkers of infection were screened for their possible role as evaluators of antibiotic treatment in an aerosol infection model of porcine pneumonia caused by Actinobacillus pleuropneumoniae (Ap). Following infection of 12 pigs, clinical signs of pneumonia developed within 20 h, whereafter...... antibiotic treatment of acute Ap-infection ill pigs. The present model provides a valuable tool in the evaluation of antibiotic treatments, offering the advantage of clinical and pathological examinations combined with the use of biochemical infection markers....... recovered clinically within 24h after treatment, whereas tiamulin-treated animals remained clinically ill until the end of the study, 48 h after treatment. A similar Picture was seen for the biomarkers of infection. During the infection period, plasma C-reactive protein (CRP), interleukin-6 and haptoglobin...
Dorey, L; Pelligand, L; Cheng, Z; Lees, P
Pharmacokinetic-pharmacodynamic (PK/PD) integration and modelling were used to predict dosage schedules of oxytetracycline for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Minimum inhibitory concentration (MIC) and mutant prevention concentration (MPC) were determined in broth and porcine serum. PK/PD integration established ratios of average concentration over 48 h (C av0-48 h )/MIC of 5.87 and 0.27 μg/mL (P. multocida) and 0.70 and 0.85 μg/mL (A. pleuropneumoniae) for broth and serum MICs, respectively. PK/PD modelling of in vitro time-kill curves established broth and serum breakpoint values for area under curve (AUC 0-24 h )/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4 log 10 reductions in bacterial count. Doses were then predicted for each pathogen, based on Monte Carlo simulations, for: (i) bacteriostatic and bactericidal levels of kill; (ii) 50% and 90% target attainment rates (TAR); and (iii) single dosing and daily dosing at steady-state. For 90% TAR, predicted daily doses at steady-state for bactericidal actions were 1123 mg/kg (P. multocida) and 43 mg/kg (A. pleuropneumoniae) based on serum MICs. Lower TARs were predicted from broth MIC data; corresponding dose estimates were 95 mg/kg (P. multocida) and 34 mg/kg (A. pleuropneumoniae). © 2017 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.
Dorey, L; Hobson, S; Lees, P
The pharmacodynamics of oxytetracycline was determined for pig respiratory tract pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Indices of potency were determined for the following: (i) two matrices, broth and pig serum; (ii) five overlapping sets of twofold dilutions; and (iii) a high strength starting culture. For A. pleuropneumoniae, minimum inhibitory concentration (MIC) was similar for the two matrices, but for P. multocida, differences were marked and significantly different. MIC and minimum bactericidal concentration (MBC) serum: broth ratios for A. pleuropneumoniae were 0.83:1 and 1.22:1, respectively, and corresponding values for P. multocida were 22.0:1 and 7.34:1. For mutant prevention concentration (MPC) serum: broth ratios were 0.79:1 (A. pleuropneumoniae) and 20.9:1 (P. multocida). These ratios were corrected for serum protein binding to yield fraction unbound (fu) serum: broth MIC ratios of 0.24:1 (A. pleuropneumoniae) and 6.30:1 (P. multocida). Corresponding fu serum: broth ratios for MPC were almost identical, 0.23:1 and 6.08:1. These corrections for protein binding did not account for potency differences between serum and broth for either species; based on fu serum MICs, potency in serum was approximately fourfold greater than predicted for A. pleuropneumoniae and sixfold smaller than predicted for P. multocida. For both broth and serum and both bacterial species, MICs were also dependent on initial inoculum strength. The killing action of oxytetracycline had the characteristics of codependency for both A. pleuropneumoniae and P. multocida in both growth media. The in vitro potency of oxytetracycline in pig serum is likely to be closer to the in vivo plasma/serum concentration required for efficacy than potency estimated in broths. © 2017 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.
Pridmore, Andrew; Burch, David; Lees, Peter
Tiamulin activity was measured against 19 UK field isolates of Actinobacillus pleuropneumoniae collected between 2003 and 2009 and the type strain ATCC 27090 as a control, with the intention of comparing broth with serum as growth media. Broth microdilution MIC/MBC tests were performed in accordance with the Clinical and Laboratory Standards Institute (CLSI) guideline M31-A3, in 'Veterinary Fastidious Medium' (VFM) (supplemented Mueller-Hinton broth at pH 7.3) and in 100% swine serum. For improved precision, a modified, overlapping doubling-dilution series was used (tiamulin concentration range 0.3-72 μg/ml). The MBC was reported as the lowest concentration producing a 99.9% reduction in bacterial density in the sub-cultured well contents, relative to the starting inoculum. The mean MBC/MIC ratio for tiamulin against A. pleuropneumoniae in VFM was low (1.74:1), even though tiamulin is classed as a bacteriostatic drug. Only three of the 19 isolates and the reference strain grew in 100% serum and their MICs were higher than those determined in VFM. It is postulated that this difference was due to differences in pH of the matrices or binding of tiamulin to serum proteins or a combination of both factors. Copyright © 2011 Elsevier B.V. All rights reserved.
Wallgren, Per; Nörregård, Erik; Molander, Benedicta; Persson, Maria; Ehlorsson, Carl-Johan
Respiratory illness is traditionally regarded as the disease of the growing pig, and has historically mainly been associated to bacterial infections with focus on Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae. These bacteria still are of great importance, but continuously increasing herd sizes have complicated the scenario and the influence of secondary invaders may have been increased. The aim of this study was to evaluate the presence of A. pleuropneumoniae and M. hyopneumoniae, as well as that of the secondary invaders Pasteurella multocida and Streptococcus suis by serology in four pig herds (A-D) using age segregated rearing systems with high incidences of pleuritic lesions at slaughter. Pleuritic lesions registered at slaughter ranged from 20.5 to 33.1 % in the four herds. In herd A, the levels of serum antibodies to A. pleuropneumoniae exceeded A 450 > 1.5, but not to any other microbe searched for. The seroconversion took place early during the fattening period. Similar levels of serum antibodies to A. pleuropneumoniae were also recorded in herd B, with a subsequent increase in levels of antibodies to P. multocida. Pigs seroconverted to both agents during the early phase of the fattening period. In herd C, pigs seroconverted to P. multocida during the early phase of the fattening period and thereafter to A. pleuropneumoniae. In herd D, the levels of antibodies to P. multocida exceeded A 450 > 1.0 in absence (A 450 hyopneumoniae and to S. suis remained below A 450 hyopneumoniae late during the rearing period (herd B-D), or not at all (herd A). Different serological patterns were found in the four herds with high levels of serum antibodies to A. pleuropneumoniae and P. multocida, either alone or in combination with each other. Seroconversion to M. hyopneumoniae late during the rearing period or not at all, confirmed the positive effect of age segregated rearing in preventing or delaying infections with M
Full Text Available Pharmacokinetic-pharmacodynamic (PK/PD integration and modelling were used to predict dosage schedules for florfenicol for two pig pneumonia pathogens, Actinobacillus pleuropneumoniae and Pasteurella multocida. Pharmacokinetic data were pooled for two bioequivalent products, pioneer and generic formulations, administered intramuscularly to pigs at a dose rate of 15 mg/kg. Antibacterial potency was determined in vitro as minimum inhibitory concentration (MIC and Mutant Prevention Concentration in broth and pig serum, for six isolates of each organism. For both organisms and for both serum and broth MICs, average concentration:MIC ratios over 48 h were similar and exceeded 2.5:1 and times greater than MIC exceeded 35 h. From in vitro time-kill curves, PK/PD modelling established serum breakpoint values for the index AUC24h/MIC for three levels of inhibition of growth, bacteriostasis and 3 and 4log10 reductions in bacterial count; means were 25.7, 40.2 and 47.0 h, respectively, for P. multocida and 24.6, 43.8 and 58.6 h for A. pleuropneumoniae. Using these PK and PD data, together with literature MIC distributions, doses for each pathogen were predicted for: (1 bacteriostatic and bactericidal levels of kill; (2 for 50 and 90% target attainment rates (TAR; and (3 for single dosing and daily dosing at steady state. Monte Carlo simulations for 90% TAR predicted single doses to achieve bacteriostatic and bactericidal actions over 48 h of 14.4 and 22.2 mg/kg (P. multocida and 44.7 and 86.6 mg/kg (A. pleuropneumoniae. For daily doses at steady state, and 90% TAR bacteriostatic and bactericidal actions, dosages of 6.2 and 9.6 mg/kg (P. multocida and 18.2 and 35.2 mg/kg (A. pleuropneumoniae were required. PK/PD integration and modelling approaches to dose determination indicate the possibility of tailoring dose to a range of end-points.
Lindecrona, R.H.; Friis, C.; Jensen, N.E.
The pharmacodynamic effect of amoxycillin and danofloxacin against two strains of Actinobacillus pleuropneumoniae was evaluated in an in-vitro pharmacodynamic model. For amoxycillin peak concentrations of 0.5, 1, and 4 mu g ml(-1) and half-lives of 3 and 15 hours were examined. For danofloxacin...... peak concentrations of 0.125, 0.5, and 1.5 mu g ml(-1) and half-lives of 1.5 and 7 hours were evaluated. The initial bactericidal effect was measured as the reduction in colony count (log CFU ml(-1)) during the first three hours, and the overall pharmacodynamic effect as the area under the bacterial...... growth versus time curve (AUBC). The initial bactericidal effect of amoxycillin was maximal at peak concentrations of two to four times the hnc. Peak concentration and half-life only influenced the pharmacodynamic effect of amoxycillin if the antibiotic concentration fell below the MIC during...
Schou, Kirstine Klitgaard; Angen, Øystein; Boye, Mette
PCR data. Preliminary results showed that in both serotype 2 and serotype 6, the toxin producing gene apxIV was the most highly expressed of the investigated genes. The major difference observed between the two serotypes was that apfA, involved in type IV vili production, was significantly upregulated...... of high virulence while serotype 6 strains are normally found to be less pathogenic. To gain an understanding of the differential virulence of serotype 2 and 6, the expression of a panel of Ap genes during infection of porcine epithelial lung cells (SJPL) were examined by quantitative real-time PCR (q...... to be important for early establishment of the bacteria in the host were examined by qPCR. The genes examined were apfA, coding for a subunit of Type IV pili, kdsB coding for a gene involved in lippopolysacceride biosynthesis, and pgaB which is involved in biofilm formation, all three believed to be important...
Mašín, Jiří; Fišer, Radovan; Linhartová, Irena; Osička, Radim; Bumba, Ladislav; Hewlett, E. L.; Benz, R.; Šebo, Peter
Roč. 81, č. 12 (2013), s. 4571-4582 ISSN 0019-9567 R&D Projects: GA ČR GAP302/12/0460; GA ČR(CZ) GAP302/11/0580; GA ČR(CZ) GAP207/11/0717; GA AV ČR IAA500200914; GA ČR GA13-14547S Institutional support: RVO:61388971 Keywords : Bordetella pertussis * Actinobacillus pleuropneumoniae * E- coli Subject RIV: EE - Microbiology, Virology Impact factor: 4.156, year: 2013
Gram, T.; Ahrens, Peter; Andreasen, Morten
. The PCR typing system was tested on 102 field strains of A. pleuropneumoniae isolated from lungs of diseased pigs. The serotyping results of the investigated field strains were in agreement with the apr and omlA gene patterns found in the reference strains of the bacteria, with the exception of the oml...... gene patterns and in 89% of the isolates using the omlA gene. The same serotype specific apx/omlA gene pattern was thus found in the majority of the tonsil isolates and in isolates from diseased lungs. Most of the differences in the omlA gene were found in 18 tonsil isolates of serotype 12. The oml...
Angen, Øystein; Jessing, Stine Graakjær; Ahrens, Peter
. However, a number of isolates show cross-reaction between serotypes and this has urged the development of quick, serotype specific DNA-based methods necessary. Serotype specific tests have until now been described for the serotypes 2, 5, and 6 (Jessing et al, 2003) and serotypes 1, 2 and 8 (Schuchert et...
Gabner, S; Egerbacher, M; Gasse, H; Hewicker-Trautwein, M; Höltig, D; Waldmann, K-H; Blecha, F; Saalmüller, A; Hennig-Pauka, I
Innate immunity is critically important for the outcome of infection in many diseases. It was previously shown that cathelicidin PR-39, an important porcine multifunctional host defence peptide, is elevated in bronchoalveolar lavage fluid and respiratory tract tissue after experimental infection with Actinobacillus pleuropneumoniae (A.pp.). To date, neutrophil polymorphonuclear leukocytes (PMNs) are thought to be the only source of PR-39. The aim of this study was to further characterize PR-39⁺ cells and selected immune cell populations in lung tissue during the peracute (7-10 hours), acute (2 days), reconvalescent (7 days) and chronic (21 days) stages of experimental infection with A.pp. serotype 2. In total, six mock-infected control pigs and 12 infected pigs were examined. Using immunofluorescence double-labeling, antibodies against PR-39 were combined with antibodies against CD3 (T-cells), CD79 (B-cells), Iba1 (activated macrophages), TTF-1 (lung epithelial cells expressing surfactant proteins), macrophage/L1 protein and myeloperoxidase (MPO, cells of the myeloid linage). In the peracute and acute phases of infection, total PR-39⁺ cells and myeloid linage cells increased, whereas CD3⁺ cells and TTF-1⁺ cells decreased. Double labeling revealed that most Macrophage/L1 protein+ cells and to a lesser extent MPO⁺ cells co-expressed PR-39. In addition, few bronchial epithelial cells and type 2 alveolar epithelial cells (both identified with TTF-1) produced PR-39. Occasionally, CD3⁺ T cells expressing PR-39 were seen in infected animals. Taken together, this study identifies cell types, other than PMNs, in lungs of A.pp.-infected pigs that are capable of producing PR-39. In addition, these findings provide further insights into the dynamics of different immune cell populations during A.pp.-infection.
Kyvsgaard, N.C.; Lind, Peter; Preuss, T.
was used as an estimate for the relative posttreatment activity. For a Toxoplasma gondii indirect enzyme-linked immunosorbent assay (ELISA) and agglutination assay as well as for a Salmonella dublin indirect ELISA, the posttreatment activity was more than 89% of the pretreatment activity when the samples...... of pretreatment activity were subject to a relatively greater decrease in activity than samples with a high level of pretreatment activity. The complement fixation assay was particularly sensitive to irradiation of serum. ft is concluded that serum samples retain sufficient activity by both methods of virus...... they were irradiated in the frozen state on dry ice but only 35% of their activity when they were irradiated in the liquid state at 0 degrees C. The patterns seen in an S. dublin blocking ELISA and an Actinobacillus pleuropneumoniae complement fixation assay differed in that samples with a low level...
Antenucci, Fabio; Fougeroux, Cyrielle; Bosse, Janine T.
and further characterized, both in silico and in vitro. Additionally, we analysed outer membrane vesicles (OMVs) of A. pleuropneumoniae MIDG2331 as potential immunogens, and compared deletions in degS and nlpI for increasing yields of OMVs compared to the parental strain. Our results indicated that Apf...
Ernie Maduratna Setiawati
Full Text Available Background: Actinobacillus actinomycetemcomitans (Aa serotype B has been associated with aggressive periodontitis. Gingival epithelial cell is exquisitely sensitive to the toxin and may lead to the epithel protective barrier disruption. Experimental models show that minocycline is not related to it’s antimicrobial effect and protection against neuron cell apoptosis of a number experimental models of brain injury and Parkinson’s disease. Purpose: This study, examined antioxidant effect of minocycline to inhibit apoptosis of gingival epithelium induced crude toxin bacteria Aa serotype B in mice. Methods: Thirty adult mice strain Swiss Webster (balb C were divided randomly into three groups: control group (group A, toxin group (group B and toxin and minocycline group (group C. The mice were taken at 24 hours after application, and then the tissue sections of gingival epithelium were stained with tunnel assay and immunohistochemistry. Result: Treatment with these toxin induced apoptosis of gingival epithelium and was associated with DNA fragmentation and reduced gluthatione (GSH. Minocycline 100 nM significantly increased GSH and reduced apoptosis (p < 0.05. Minocycline provides antioxidant effect against citotoxicity of bacteria Aa serotipe B. Conclusion: Nanomolar concentration of minocycline potential as new therapeutic agent to prevent progressivity of aggressiveness of periodontitis.
Andreasen, Margit; Nielsen, Jens; Bækbo, Poul
Sixteen litters of seven pigs from each of nine Danish farrow-to-finish herds were followed to investigate the serological patterns caused by natural infection with Mycoplasma hyponeumoniae, Pasteurella multocida toxin and Actinobacillus pleuroneumoniae serotypes 2, 5-7, 12. In seven of the herds......, pigs were followed as two separate cohorts started 4 weeks apart, and in two herds only one cohort was followed. A total of 999 pigs were included in the study. The pigs were blood sampled at weaning and subsequently every fourth week until slaughter. All pigs were examined for antibodies against M....... hyopneumoniae (enzyme-linked immunosorbent assay), P. multocida toxin (enzyme-linked immunosorbent assay) and A. pleuropneumoniae serotypes 2, 5-7, 12 (complement-fixation tests). The most-common pattern (28%) of seroconversion was that of pigs first seroconverting to A. pleuropneumoniae serotype 2, followed...
Hennig-Pauka, Isabel; Koch, Rüdiger; Hoeltig, Doris; Gerlach, Gerald-F; Waldmann, Karl-Heinz; Blecha, Frank; Brauer, Carsten; Gasse, Hagen
Host defence peptides are important components of mammalian innate immunity. We have previously shown that PR-39, a cathelicidin host defence peptide, is an important factor in porcine innate immune mechanisms as a first line of defence after infection with Actinobacillus pleuropneumoniae. PR-39 interacts with bacterial and mammalian cells and is involved in a variety of processes such as killing of bacteria and promotion of wound repair. In bronchoalveolar lavage fluid of infected pigs PR-39 concentrations are elevated during the chronic but not during the acute stage of infection when polymorphonuclear neutrophils (known as the major source of PR-39) are highly increased. Thus it was assumed, that the real impact of PR-39 during infection might not be reflected by its concentration in bronchoalveolar lavage fluid. Using immunohistochemistry this study demonstrates the actual distribution of PR-39 in tissue of the upper and lower respiratory tract of healthy pigs, and of pigs during the acute and chronic stage of experimental infection with Actinobacillus pleuropneumoniae.During the acute stage of infection PR-39 accumulated adjacent to blood vessels and within bronchi. Immune reactions were mainly localized in the cytoplasm of cells with morphological characteristics of polymorphonuclear neutrophils as well as in extracellular fluids. During the chronic stage of infection pigs lacked clinical signs and lung alterations were characterized by reparation and remodelling processes such as tissue sequestration and fibroblastic pleuritis with a high-grade accumulation of small PR-39-positive cells resembling polymorphonuclear neutrophils. In healthy pigs, PR-39 was homogenously expressed in large single cells within the alveoli resembling alveolar macrophages or type 2 pneumocytes. PR-39 was found in all tissue samples of the upper respiratory tract in healthy and diseased pigs. Within the tracheobronchial lymph nodes, PR-39 dominated in the cytoplasm and nuclei of
Gram, Trine; Ahrens, Peter
species related to A. pleuropneumoniae or isolated from pigs were assayed. They were all found negative in the PCR, as were tonsil cultures from 50 pigs of an A. pleuropneumoniae-negative herd. The sensitivity assessed by agarose gel analysis of the PCR product was 10(2) CFU/PCR test tube. The specificity...
Jakobsen, Marianne; Nielsen, Jens
In order to isolate ActinobacillIus pleuropneumoniae from mixed bacterial flora a selective and indicative medium was developed. The optimal concentrations of antibiotics were determined for selective chocolate agar (S-TSA) and selective blood agar (S-MBA) using a set of 25 strains of A. pleuropn......In order to isolate ActinobacillIus pleuropneumoniae from mixed bacterial flora a selective and indicative medium was developed. The optimal concentrations of antibiotics were determined for selective chocolate agar (S-TSA) and selective blood agar (S-MBA) using a set of 25 strains of A...
Sjölund, M; Fossum, C; Martin de la Fuente, AJM
-free pigs were allocated to five groups of six. After acclimatisation, four groups were inoculated with A pleuropneumoniae serotype 2. At the onset of clinical signs, three of the groups of pigs were treated with enrofloxacin, tetracycline or penicillin. A fourth group served as the inoculated control......-binding lectin-A response was less evident in the pigs. Acute phase responses resembling those of the first inoculation were observed in the pigs that had not previously been inoculated and in the pigs treated with enrofloxacin. Acute phase responses were not recorded in the other three groups, where the pigs...
Schou, Kirstine Klitgaard; Rundsten, Carsten Friis; Jensen, Tim Kåre
in response to environmental stimuli is critical for bacterial survival within the host. The genes identified as differentially expressed in this study may represent a core set of genes which are mobilized to cope with the host immune response and adapt to the hostile environment. The potential virulence......Aim: To obtain an increased understanding of how the porcine lung pathogen Actinobacillus pleuropneumoniae (Ap) establish infection in the host. Understanding the means by which a pathogen establishes and maintains infection in the host organism is the first step towards controlling disease...
Gram, T.; Ahrens, Peter; Nielsen, J.P.
strains of A. lignieresii. The lower detection limit of the PCR test was 10(3) A. pleuropneumoniae CFU/PCR test tube and was not affected by addition of 10(6) E. coli CFU/PCR test tube. Mixed bacterial cultures from tonsils of 101 pigs from 9 different herds were tested by culture and by PCR using four...
van Dixhoorn, Ingrid D E; Reimert, Inonge; Middelkoop, Jenny; Bolhuis, J Elizabeth; Wisselink, Henk J; Groot Koerkamp, Peter W G; Kemp, Bas; Stockhofe-Zurwieden, Norbert
Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome of infectious diseases. Therefore psychoneuro-immunological intervention may prove to be a successful approach to diminish the impact of diseases and antibiotics use. This study was designed to investigate the effect of social and environmental enrichment on the impact of disease, referred to as "disease susceptibility", in pigs using a co-infection model of PRRSV and A. pleuropneumoniae. Twenty-eight pigs were raised in four pens under barren conditions and twenty-eight other pigs were raised in four pens under enriched conditions. In the enriched pens a combination of established social and environmental enrichment factors were introduced. Two pens of the barren (BH) and two pens of the enriched housed (EH) pigs were infected with PRRSV followed by A. pleuropneumoniae, the other two pens in each housing treatment served as control groups. We tested if differences in disease susceptibility in terms of pathological and clinical outcome were related to the different housing regimes and if this was reflected in differences in behavioural and immunological states of the animals. Enriched housed pigs showed a faster clearance of viral PRRSV RNA in blood serum (p = 0.014) and histologically 2.8 fold less interstitial pneumonia signs in the lungs (p = 0.014). More barren housed than enriched housed pigs developed lesions in the lungs (OR = 19.2, p = 0.048) and the lesions in the barren housed pigs showed a higher total pathologic tissue damage score (ppigs. EH pigs showed less stress-related behaviour and differed immunologically and clinically from BH pigs. We conclude that enriched housing management reduces disease susceptibility to co-infection of PRRSV and A
Ingrid D E van Dixhoorn
Full Text Available Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome of infectious diseases. Therefore psychoneuro-immunological intervention may prove to be a successful approach to diminish the impact of diseases and antibiotics use. This study was designed to investigate the effect of social and environmental enrichment on the impact of disease, referred to as "disease susceptibility", in pigs using a co-infection model of PRRSV and A. pleuropneumoniae. Twenty-eight pigs were raised in four pens under barren conditions and twenty-eight other pigs were raised in four pens under enriched conditions. In the enriched pens a combination of established social and environmental enrichment factors were introduced. Two pens of the barren (BH and two pens of the enriched housed (EH pigs were infected with PRRSV followed by A. pleuropneumoniae, the other two pens in each housing treatment served as control groups. We tested if differences in disease susceptibility in terms of pathological and clinical outcome were related to the different housing regimes and if this was reflected in differences in behavioural and immunological states of the animals. Enriched housed pigs showed a faster clearance of viral PRRSV RNA in blood serum (p = 0.014 and histologically 2.8 fold less interstitial pneumonia signs in the lungs (p = 0.014. More barren housed than enriched housed pigs developed lesions in the lungs (OR = 19.2, p = 0.048 and the lesions in the barren housed pigs showed a higher total pathologic tissue damage score (p<0.001 than those in enriched housed pigs. EH pigs showed less stress-related behaviour and differed immunologically and clinically from BH pigs. We conclude that enriched housing management reduces disease
Podolska, Agnieszka; Anthon, Christian; Bak, Mads
significantly up-regulated in the necrotic sample and 12 were down-regulated. The expression analysis of a number of candidates revealed microRNAs of potential importance in the innate immune response. MiR-155, a known key player in inflammation, was found expressed in both samples. Moreover, miR-664-5p, mi......R-451 and miR-15a appear as very promising candidates for microRNAs involved in response to pathogen infection. Conclusions: This is the first study revealing significant differences in composition and expression profiles of miRNAs in lungs infected with a bacterial pathogen. Our results extend......Background: MicroRNAs (miRNAs) are a class of non-protein-coding genes that play a crucial regulatory role in mammalian development and disease. Whereas a large number of miRNAs have been annotated at the structural level during the latest years, functional annotation is sparse. Actinobacillus...
Fussing, V.; Barfod, Kristen; Nielsen, R.
was indicated in one of two cases. In many cases findings of predominant ribotypes made interpretations of suspected routes of transmission difficult. The relationship of strains based on ribotypes was calculated using Dices coefficient and clustered by UPGMA. HindIII ribotypes of serotype 2 strains were...
Mortensen, Shila; Skovgaard, Kerstin; Hedegaard, Jakob
The local transcriptional response was studied in different locations of lungs from pigs experimentally infected with the respiratory pathogen Actinobacillus pleuropneumoniae serotype 5B, using porcine cDNA microarrays. This infection gives rise to well-demarcated infection loci in the lung...... of apoptosis and the complement system. Interferon-g was downregulated in both necrotic and bordering areas. Evidence of neutrophil recruitment was seen by the up-regulation of chemotactic factors for neutrophils. In conclusion, we found subsets of genes expressed at different levels in the three selected...... of induced genes as, in unaffected areas a large part of differently expressed genes were involved in systemic reactions to infections, while differently expressed genes in necrotic areas were mainly concerned with homeostasis regulation....
Full Text Available Aggregatibacter (Actinobacillus actimycetemcomitans (Aa is a gram-negative bacterium that colonizes the human oral cavity and is causative agent for localized aggressive (juvenile periodontitis (AgP. In the middle of 1990s, a specific JP2 clone of belonging to the cluster of serotype b strains of Aa with highly leukotoxicity (leukotoxin, LtxA able to kill human immune cells was isolated. JP2 clone of Aa was strongly associated with in particularly in rapidly progressing forms of aggressive periodontitis. The JP2 clone of Aa is transmitted through close contacts. Therefore, AgP patients need intense monitoring of their periodontal status as the risk for developing severely progressing periodontitis lesions are relatively high. Furthermore, timely periodontal treatment, including periodontal surgery supplemented by the use of antibiotics, is warranted. More importantly, periodontal attachment loss should be prevented by early detection of the JP2 clone of Aa by microbial diagnosis testing and/or preventive means. Keywords: Aggregatibacter (Actinobacillus actinomycetemcomitans, Aggressive periodontitis, Leukotoxin (LtxA, Polymorphonuclear leukocytes (PMNs
Bøg, Yang S.; Andresen, Lars Ole; Bastholm, L.
transferrin. This complex was studied using a monoclonal antibody (Mab 1.48) raised against a synthetic peptide corresponding to a hydrophilic domain of Tbp2 common to several A. pp serotypes. The antibody reacted specifically with a 60-70 kDa Tbp2-antigen found in all serotypes of A. pp obtained from iron...... expressing Tbp2 and in wild type A. pp grown under iron restricted conditions. The subcellular location of Tbp2 in A. pp was studied by immunoelectron microscopy using the Mab 1.48. Interestingly, all antibody binding was found inside the A. pp cells, while Tbp2 expressed in recombinant E. coli was found...
Skovgaard, Kerstin; Schou, Kirstine Klitgaard; Wendt, Karin Tarp
MicroRNAs are small non-coding RNA molecules (18-23 nt), that regulate the activity of other genes at the post-transcriptional level. Recently it has become evident that microRNA plays an important role in modulating and fine tuning innate and adaptive immune responses. Still, little is known about...... the impact of microRNAs in the development and pathogenesis of lung infections. Expression of microRNA known to be induced by bacterial (i.e., LPS) ligands and thus supposed to play a role in the regulation of antimicrobial defence, were studied in lung tissue and in blood from pigs experimentally infected...... with Actinobacillus pleuropneumoniae (AP). Expression differences of mRNA and microRNA were quantified at different time points (6h, 12h, 24h, 48h PI) using reverse transcription quantitative real-time PCR (Rotor-Gene and Fluidigm). Expression profiles of miRNA in blood of seven animals were further studied using mi...
Kokotovic, Branko; Bisgaard, Magne; Angen, Øystein
Within the family Pasteurellaceae Pohl 1981 most taxa seem to be host specific. The aim of the present study was to investigate if bovine and ovine isolates of Actinobacillus lignieresii represent host specific subclones of this taxon. For comparison and to investigate the diagnostic potential...
Kruse, Amanda Brinch; de Knegt, Leonardo Victor; Nielsen, Liza Rosenbaum
common endemic infections: Mycoplasma hyopneumoniae, Actinobacillus pleuropneumoniae, porcine circovirus type II, porcine reproductive and respiratory syndrome virus, and Lawsonia intracellularis. Comparison was made to the change after a randomly selected date in herds not vaccinating against each...
Friis-Møller, Alice; Christensen, J J; Fussing, V
Clinical findings in 36 immunosuppressed patients with lower respiratory tract infection or bacteremia with Actinobacillus hominis are described. Animal contact was only recorded for three patients; nine patients died despite appropriate antimicrobial treatment. Although infections with this micr......Clinical findings in 36 immunosuppressed patients with lower respiratory tract infection or bacteremia with Actinobacillus hominis are described. Animal contact was only recorded for three patients; nine patients died despite appropriate antimicrobial treatment. Although infections...
Skovgaard, Kerstin; Mortensen, Shila; Boye, Mette
Knowledge on gene expression in the liver during respiratory infections is limited although it is well-established that this organ is an important site of synthesis of several systemic innate immune components as response to infections. In the present study, the early transcriptional hepatic...... in initiating and orchestrating the innate immune response to A. pleuropneumoniae infection. Keywords: acute phase protein, hepatic transcriptional response, innate defence, gene expression, pig...... differentially expressed. A large group of these genes encoded proteins involved in the acute phase response, including serum amyloid A, C-reactive protein, fibrinogen, haptoglobin and tumor necrosis factor-a the expression of which were all found to be up-regulated and glutathione S-transferase, transthyretin...
Mul, M.F.; Becker, P.M.; Peet-Schwering, van der C.M.C.; Wikselaar, van P.G.; Wisselink, H.J.; Stockhofe, N.
De Animal Sciences Group van Wageningen UR heeft in opdracht van biologische varkenshouders onderzocht of het mogelijk is om in plaats van antibiotica, knoflook te gebruiken voor de bestrijding van longontsteking door de bacterie Actinobacillus pleuropneumoniae (App). Uit de resultaten blijkt dat
Carpintero, R.; Pineiro, M.; Andres, M.
In this work, apolipoprotein A-I (ApoA-I) was purified from pig sera. The responses of this protein after sterile inflammation and in animals infected with Actinobacillus pleuropneumoniae or Streptococcus suis were investigated. Decreases in the concentrations of ApoA-I, two to five times lower...
2Addis Ababa University, Faculty of Veterinary Medicine, Debre Zeit, Ethiopia, PO ... conducted on contagious caprine pleuropneumonia in selected districts of Borana ..... A Text Book of the Disease of Cattle, Sheep, Pigs, Goats and Horses.
Full Text Available MeCab user dictionary for science technology term Actinobacillus actinomycetemcomit...ans 名詞 一般 * * * * Actinobacillus actinomycetemcomitans ... MeSH D016976 200906016161948020 C LS07 UNKNOWN_2 Actinobacillus actinomycetemcomitans
Contagious bovine pleuropneumonia (CBPP) is a trans-boundary infectious and contagious respiratory disease of cattle caused by Mycoplasma mycoides subsp. mycoides. It is a disease of high economic importance because of its ability to compromise food security. Information on its economic burden in pastoral cattle ...
Abstract. Contagious bovine pleuropneumonia (CBPP) is a disease of cattle caused by ... of veterinary departments have resulted in CBPP running riot in east and ... 5 334 of Sheep, 9 253 of Goat, 72 of Horses, 601 of Mules, 3 300 of Donkeys.
Full Text Available AK058464 001-016-A10 U27202.1 Actinobacillus pleuropneumoniae riboflavin biosynthesis operon, riboflavin...-specific deaminase (ribG), riboflavin synthase alpha subunit (ribB), bifunctional GTP ...cyclohydrase II/3,4-dihydroxy-2-butanone-4-phosphate synthase (ribA), and riboflavin synthase beta subunit (ribH) genes, complete cds.|BCT BCT 1e-105 +2 ...
HARADA, Kazuki; USUI, Masaru; ASAI, Tetsuo
ABSTRACT In this study, susceptibilities of Pasteurella multocida, Mannheimia haemolytica and Actinobacillus pleuropneumoniae to enrofloxacin and orbifloxacin were tested using an agar diffusion method with the commercial disks and a broth microdilution method. Good correlation between the 2 methods for enrofloxacin and orbifloxacin was observed for P. multocida (r = −0.743 and −0.818, respectively), M. haemolytica (r = −0.739 and −0.800, respectively) and A. pleuropneumoniae (r = −0.785 and −0.809, respectively). Based on the Clinical and Laboratory Standards Institute interpretive criteria for enrofloxacin, high-level categorical agreement between the 2 methods was found for P. multocida (97.9%), M. haemolytica (93.8%) and A. pleuropneumoniae (92.0%). Our findings indicate that the tested commercial disks can be applied for susceptibility testing of veterinary respiratory pathogens. PMID:25008965
Incidence of Reinfections with Mycoplasma hyopneumoniae and Actinobacillus pleuropneumoniae in Pig Farms Located in Respiratory-Disease-Free Regions of Switzerland – Identification and Quantification of Risk Factors
Full Text Available The objective of the study was to identify risk factors for reintroduction of Actinobacillus pleuopneumoniae and Mycoplasma hyopneumoniae (enzootic pneumonia onto pig farms in areas in Switzerland that were involved in an eradication programme from 1996 to 1999 and to assess the role of dealers in relation to these reinfections. The study was based on the comparison of pig farms that were reinfected in the year 2000 (cases and pig farms that remained uninfected in the same area (controls. Additionally, data were collected from Swiss pig dealers and transport companies. Out of a total of 3983 farms, 107 farms were reinfected in the year 2000. The incidences were 0.1% for Actinobacillus pleuopneumoniae and 2.6% for Mycoplasma hyopneumoniae (enzootic pneumonia. Compared to reinfection rates prior to the eradication programme, this is a considerable reduction. Statistically significant risk factors for the reinfection were 'finishing farm', 'large mixed breeding-finishing farm', 'reinfected neighbour' and 'parking site for pig transport vehicles close to the farm'. Pig farmers that purchased pigs from only one supplier per batch had a lower risk of reintroducing infection (protective factor. As long as infected and uninfected regions co-exist in Switzerland, direct and indirect contact between farms, pig herds and slaughter sites via transport vehicles are a major pathway of disease spread. Risk management measures linked to these contacts are therefore of key importance. The survey of dealers indicated various areas for improvement such as strategic planning of pick-up routes or cleaning and disinfecting of trucks.
Kleinfelder, JW; Mueller, RF; Lange, DE
Background: Periodontitis patients harboring Actinobacillus actinmycetemcomitans (Aa) are prime candidates for systemic antibiotic therapy. Besides tetracycline and the combination of metronidazole and amoxicillin the fluoroquinolones are also believed to have antibacterial activity against Aa. The
and occasional periodontal abscess formation with concomitant regional lymph node enlargement (12). The prevalence of localized aggressive periodontitis ...brain abscesses , it is the primary pathogen associated with the initiation and progression of localized aggressive periodontitis . In light of recent...Professor: Ellen B. Kraig, Ph.D. The association between Actinobacillus actinomycetemcomitans (Aa) and aggressive periodontitis is well documented
Angen, Øystein; Ussery, David
Introduction The bacterial genome sequences are now available for an increasing number of strains within the family Pasteurellaceae. At present, 24 Pasteurellaceae genomes are publicly available through internet databases, and another 40 genomes are being sequenced. This investigation will describe...... the core genome for both the family Pasteurellaceae and for the species Haemophilus influenzae. Methods Twenty genome sequences from the following species were included: Haemophilus influenzae (11 strains), Haemophilus ducreyi (1 strain), Histophilus somni (2 strains), Haemophilus parasuis (1 strain......), Actinobacillus pleuropneumoniae (2 strains), Actinobacillus succinogenes (1 strain), Mannheimia succiniciproducens (1 strain), and Pasteurella multocida (1 strain). The predicted proteins for each genome were BLASTed against each other, and a set of conserved core gene families was determined as described...
Andersen, H; Christiansen, Gunna; Christiansen, C
The acidic proteins of six different mycoplasma serotypes causing bovine or caprine pleuropneumonia were compared by two-dimensional gel electrophoresis of extracts of 35S-labelled cells. The organisms investigated were Mycoplasma mycoides subsp. mycoides (PG1), M. mycoides subsp. mycoides (Y......, whereas the two M. mycoides subspecies appeared to be quite distant from M. capricolum and F38. The representative strain of the bovine serogroup 7 of Leach was equally distant from F38, M. capricolum and the three strains of M. mycoides. Strikingly, all six mycoplasma strains apparently shared six...... proteins in the two-dimensional gels. In Escherichia coli minicells, DNA from strain PG50 cloned in the vector pBR325 gave rise to incorporation of radioactive label into proteins which were identified as mycoplasma proteins by two-dimensional electrophoresis and immunoprecipitation....
Nurhonen, Markku; Auranen, Kari
Pneumococcal conjugate vaccination has proved highly effective in eliminating vaccine-type pneumococcal carriage and disease. However, the potential adverse effects of serotype replacement remain a major concern when implementing routine childhood pneumococcal conjugate vaccination programmes. Applying a concise predictive model, we present a ready-to-use quantitative tool to investigate the implications of serotype replacement on the net effectiveness of vaccination against invasive pneumococcal disease (IPD) and to guide in the selection of optimal vaccine serotype compositions. We utilise pre-vaccination data on pneumococcal carriage and IPD and assume partial or complete elimination of vaccine-type carriage, its replacement by non-vaccine-type carriage, and stable case-to-carrier ratios (probability of IPD per carriage episode). The model predicts that the post-vaccination IPD incidences in Finland for currently available vaccine serotype compositions can eventually decrease among the target age group of children replacement through herd effects, the decrease among the older population is predicted to be much less (20-40%). We introduce a sequential algorithm for the search of optimal serotype compositions and assess the robustness of inferences to uncertainties in data and assumptions about carriage and IPD. The optimal serotype composition depends on the age group of interest and some serotypes may be highly beneficial vaccine types in one age category (e.g. 6B in children), while being disadvantageous in another. The net effectiveness will be improved only if the added serotype has a higher case-to-carrier ratio than the average case-to-carrier ratio of the current non-vaccine types and the degree of improvement in effectiveness depends on the carriage incidence of the serotype. The serotype compositions of currently available pneumococcal vaccines are not optimal and the effectiveness of vaccination in the population at large could be improved by including
Lykkeberg, Anne Kruse; Halling-Sørensen, Bent; Jensen, Lars Bogø
:Susceptibilities to metabolites of tiamulin (TIA) and enrofloxacin (ENR) were tested using selected bacteria with previously defined minimal inhibitory concentrations,(,MIC). The TIA metabolites tested were: N-deethyl-tiamulin (I)TIA), 2 beta-hydroxy-tiamulin (2 beta-HTIA),and Sammhydroxy......-tiamulin (8 alpha-HTIA), and the ENR metabolites were: ciprofloxacin (CIP) and enrofloxacin N-oxide (ENR-N). Bacteria, all of porcine origin, we're selected as representatives of bacterial infections (Stap4ylococcus hyicus and Actinobacillus pleuropneumoniae), zoonotic bacteria (Campylobacter coli...
Mauro José Gonçalves Bezerra
Full Text Available Relata-se a ocorrência de orquite e epididimite ovina associada ao isolamento de Actinobacillus seminis no Estado de Pernambuco. Clinicamente observou-se aumento de volume nos testículos e epidídimos, dor e aumento de temperatura local à palpação, e atrofia testicular bilateral. Após o abate observou-se a presença de conteúdo purulento no epidídimo. À microscopia dos testículos observou-se espessamento da túnica albugínea, necrose de coagulação e calcificação de túbulos seminíferos, infiltrado inflamatório com predominância de linfócitos entre túbulos seminíferos, além de mineralização incipiente de túbulos. No epidídimo observou-se intensa proliferação de tecido conjuntivo ao redor dos ductos epididimários. O diagnóstico de orquite e epididimite por Actinobacillus seminis foi confirmado pela associação dos achados clínico-patológicos, isolamento e identificação da bactéria.
Friis-Møller, Alice; Christensen, J J; Fussing, V
with this microorganism seem to be rare, the fact that 37 of 46 strains characterized in this study have been found in Copenhagen indicates that under-reporting may occur. A. hominis is phenotypically relatively homogeneous but can be difficult to differentiate from other Actinobacillus species unless extensive...... biochemical testing is performed. Mannose-positive strains of A. hominis are especially difficult to differentiate from A. equuli. Attempts to identify A. hominis by automatic identification systems may lead to misidentifications. Ribotyping and DNA-DNA hybridization data show that A. hominis is a homogeneous...
Groenink, J; Veerman, ECI; Zandvoort, MS; van der Mei, HC; Busscher, HJ; Amerongen, AVN
The adhesion of Actinobacillus actinomycetemcomitans is a virulence factor in the aetiology of periodontitis and is determined by physico-chemical properties, e.g. surface charge and hydrophobicity, of the bacterial cell surface. Although oral surfaces are constantly coated with saliva, few studies
Gcwalisile B. Zulu
Full Text Available Bluetongue (BT is a non-contagious disease of sheep and other domestic and wild ruminants caused by the bluetongue virus (BTV. Currently 26 serotypes of the virus have been identified. In South Africa, 22 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze-dried live attenuated polyvalent BTV vaccine. The vaccine is constituted of 15 BTV serotypes divided into three separate bottles and the aim is to develop a vaccine using fewer serotypes without compromising the immunity against the disease. This study is based on previously reported cross-neutralisation of specific BTV serotypes in in vitro studies. Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control, 1 (unrelated serotype, 9, 10 and 11 in sheep using the serum neutralisation test. The purpose of the study was to determine possible cross-protection of different serotypes in sheep. Of those vaccinated with BTV-4 and challenged with BTV-1, which is not directly related to BTV-4, 20% were completely protected and 80% showed clinical signs, but the reaction was not as severe as amongst the unvaccinated animals. In the group challenged with BTV-10, some showed good protection and some became very sick. Those challenged with BTV-9 and BTV-11 had good protection. The results showed that BTV-4 does not only elicit a specific immune response but can also protect against other serotypes.
Nørskov-Lauritsen, Niels; Christensen, H; Okkels, H.
A 426 bp fragment of infB, a housekeeping gene that encodes translation initiation factor 2, was sequenced from 59 clinical isolates and type strains of Actinobacillus species and sequences were compared. Partial sequences of 16S rRNA genes were also obtained. By comparing infB sequences, Actinob...
Aalbæk, Bent; Østergaard, Stine; Buhl, Rikke
Microbiological and pathological data from a case of equine valvular endocarditis are reported. Limited information is available on the pathogenic potential of equine Actinobacillus species as several strains originate from apparently healthy horses. After the establishment of two subspecies within...... this species, this seems to be the first report of an etiological association between A. equuli subsp. equuli and equine endocarditis. Furthermore, new information on some phenotypical characteristics of this subspecies are reported, compared to previous findings...
Full Text Available Abstract Background Shigella flexneri is the major pathogen causing bacillary dysentery. Fifteen serotypes have been recognized up to now. The genesis of new S. flexneri serotypes is commonly mediated by serotype-converting bacteriophages. Untypeable or novel serotypes from natural infections had been reported worldwide but have not been generated in laboratory. Results A new S. flexneri serotype-serotype 1 d was generated when a S. flexneri serotype Y strain (native LPS was sequentially infected with 2 serotype-converting bacteriophages, SfX first and then SfI. The new serotype 1 d strain agglutinated with both serotype X-specific anti-7;8 grouping serum and serotype 1a-specific anti- I typing serum, and differed from subserotypes 1a, 1b and 1c. Twenty four S. flexneri clinical isolates of serotype X were all converted to serotype 1 d by infection with phage SfI. PCR and sequencing revealed that SfI and SfX were integrated in tandem into the proA-yaiC region of the host chromosome. Conclusions These findings suggest a new S. flexneri serotype could be created in nature. Such a conversion may be constrained by susceptibility of a strain to infection by a given serotype-converting bacteriophage. This finding has significant implications in the emergence of new S. flexneri serotypes in nature.
Full Text Available Introduction: The bacteria that cause the occurrence of pathogens of periodontal disease are gram negative anaerobes. These bacteria include Pophyromonas Gingivalis and Actinobacillus Actinomycetemcomitans. Mangosteen skin extract is known to have anti-inflammatory, anti microbial, and anti oxidant properties. The extract of the mangosteen peel is altered in gel preparation in order to streamline its clinical application in periodontal disease. The purpose of this study was to examine the antibacterial power of the ginger mangosteen tree extract gel against Pophyromonas gingivalis and Actinobacillus Actinomycetemcomitans (Aggregatibacter Actinomycetemcomitans. Methods: This research was conducted by experimental laboratory. Mangosteen fruit extract gel with concentration of 100%, 50%, 25%, 12,5%, 6,25%, 3,125% and 0,78% were tested against Pophyromonas Gingivalis and Aggregatibacter Actinomycetemcomitans with agar diffusion method. Results and Discussion: The results of this study indicate that for Actinobacilus Aggregatibacter bacteria minimal inhibitory concentration at a concentration of 6.25% with a diameter of 13,5mm inhibition. Minimal bactericidal concentration at 12,5% concentration with 14,7mm inhibitory diameter. In the test of Pophyromonas Gingivalis bacteria, minimal inhibitory concentrations were obtained at a concentration of 1.56% and a minimum bactericidal concentration was obtained at a concentration of 3.125%. Conclusion: The conclusion that mangosteen peel skin gel extract can inhibit bacterial growth and is bactericidal against Pophyromonas Gingivalis and Actinobacillus Actinomycetemcomitans (Aggregatibacter Actinomycetecomitans.
Piao, Shunfu; Xu, Yongbin; Ha, Nam-Chul
A periplasmic membrane-fusion protein MacA from Actinobacillus actinomycetemcomitans, an essential component of the multidrug efflux pump in Gram-negative bacteria, was crystallized. Periplasmic membrane-fusion proteins (MFPs) are an essential component of the multidrug efflux pump in Gram-negative bacteria. They play a crucial role in bridging the outer membrane porin TolC and two distinct types of inner membrane transporters. The MFP MacA bridges the inner membrane ABC-type multidrug transporter MacB and the outer membrane porin TolC. MacA from the pathogenic bacterium Actinobacillus actinomycetemcomitans was expressed in Escherichia coli B834 (DE3) and the recombinant protein was purified using Ni–NTA affinity, Q anion-exchange and gel-filtration chromatography. The purified MacA protein was crystallized using the vapour-diffusion method. A MAD diffraction data set was collected to a resolution of 3.0 Å at 100 K. The crystal belongs to space group P622, with unit-cell parameters a = b = 109.2, c = 255.4 Å, α = β = 90, γ = 120°, and contains one molecule in the asymmetric unit
Piao, Shunfu; Xu, Yongbin; Ha, Nam-Chul, E-mail: firstname.lastname@example.org [College of Pharmacy and Research Institute for Drug Development, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735 (Korea, Republic of)
A periplasmic membrane-fusion protein MacA from Actinobacillus actinomycetemcomitans, an essential component of the multidrug efflux pump in Gram-negative bacteria, was crystallized. Periplasmic membrane-fusion proteins (MFPs) are an essential component of the multidrug efflux pump in Gram-negative bacteria. They play a crucial role in bridging the outer membrane porin TolC and two distinct types of inner membrane transporters. The MFP MacA bridges the inner membrane ABC-type multidrug transporter MacB and the outer membrane porin TolC. MacA from the pathogenic bacterium Actinobacillus actinomycetemcomitans was expressed in Escherichia coli B834 (DE3) and the recombinant protein was purified using Ni–NTA affinity, Q anion-exchange and gel-filtration chromatography. The purified MacA protein was crystallized using the vapour-diffusion method. A MAD diffraction data set was collected to a resolution of 3.0 Å at 100 K. The crystal belongs to space group P622, with unit-cell parameters a = b = 109.2, c = 255.4 Å, α = β = 90, γ = 120°, and contains one molecule in the asymmetric unit.
Haubek, Dorte; Ennibi, O.-K.; Poulsen, Knud
A particular clone (JP2) of Actinobacillus actinomycetemcomitans with increased leukotoxin production has been isolated from individuals with early-onset periodontitis (EOP). The aim of this study was to determine the frequency of carriers of this clone and its association with EOP in Moroccan...
Full Text Available Flavobacterium psychrophilum is a devastating bacterial pathogen of salmonids reared in freshwater worldwide. So far, serological diversity between isolates has been described but the underlying molecular factors remain unknown. By combining complete genome sequence analysis and the serotyping method proposed by Lorenzen and Olesen (1997 for a set of 34 strains, we identified key molecular determinants of the serotypes. This knowledge allowed us to develop a robust multiplex PCR-based serotyping scheme, which was applied to 244 bacterial isolates. The results revealed a striking association between PCR-serotype and fish host species and illustrate the use of this approach as a simple and cost-effective method for the determination of F. psychrophilum serogroups. PCR-based serotyping could be a useful tool in a range of applications such as disease surveillance, selection of salmonids for bacterial coldwater disease resistance and future vaccine formulation.
Antenucci, Fabio; Fougeroux, Cyrielle; Deeney, Alannah
vesicles from its outer membrane (OM), accordingly defined as outer membrane vesicles (OMVs). Thanks to their antigenic similarity to the OM, OMVs have emerged as a promising tool in vaccinology. In this study we describe the in vivo testing of several vaccine prototypes for the prevention of infection...
Benfield, Thomas Lars Vibe; Skovgaard, Marlene; Schønheyder, Henrik Carl
There is limited knowledge of serotypes that cause non-bacteremic pneumococcal pneumonia (NBP). Here we report serotypes, their associated disease potential and coverage of pneumococcal conjugate vaccines (PCV) in adults with NBP and compare these to bacteremic pneumonia (BP).......There is limited knowledge of serotypes that cause non-bacteremic pneumococcal pneumonia (NBP). Here we report serotypes, their associated disease potential and coverage of pneumococcal conjugate vaccines (PCV) in adults with NBP and compare these to bacteremic pneumonia (BP)....
Pasma, Satriani Aga; Daik, Rusli; Maskat, Mohamad Yusof
Succinic acid is a common metabolite in plants, animals and microorganisms. It has been used widely in agricultural, food and pharmaceutical industries. Enzymatic hydrolysate glucose from oil palm empty fruit bunch (OPEFB) cellulose was used as a substrate for succinic acid production using Actinobacillus succinogenes. Using cellulose extraction from OPEFB can enhance the production of glucose as a main substrate for succinic acid production. The highest concentration of glucose produced from enzymatic hydrolysis is 167 mg/mL and the sugar recovery is 0.73 g/g of OPEFB. By optimizing the culture medium for succinic acid fermentation with enzymatic hydrolysate of OPEFB cellulose, the nitrogen sources could be reduced to just only 2.5 g yeast extract and 2.5 g corn step liquor. Batch fermentation was carried out using enzymatic hydrolysate of OPEFB cellulose with yeast extract, corn steep liquor and the salts mixture, 23.5 g/L succinic acid was obtained with consumption of 72 g/L glucose in enzymatic hydrolysate of OPEFB cellulose at 38 hours and 37°C. This study suggests that enzymatic hydrolysate of OPEFB cellulose maybe an alternative substrate for the efficient production of succinic acid by Actinobacillus succinogenes.
Full Text Available Abstract Background Group B Streptococcus (GBS serotype (Ia, Ib, II-IX correlates with pathogen virulence and clinical prognosis. Epidemiological studies of seroprevalence are an important metric for determining the proportion of serotypes in a given population. The purpose of this study was to evaluate the prevalence of individual GBS serotypes at Madigan Healthcare System (Madigan, the largest military tertiary healthcare facility in the Pacific Northwestern United States, and to compare seroprevalences with international locations. Methods To determine serotype distribution at Madigan, we obtained GBS isolates from standard-of-care anogenital swabs from 207 women of indeterminate gravidity between ages 18-40 during a five month interval. Serotype was determined using a recently described molecular method of polymerase chain reaction by capsular polysaccharide synthesis (cps genes associated with pathogen virulence. Results Serotypes Ia, III, and V were the most prevalent (28%, 27%, and 17%, respectively. A systematic review of global GBS seroprevalence, meta-analysis, and statistical comparison revealed strikingly similar serodistibution at Madigan relative to civilian-sector populations in Canada and the United States. Serotype Ia was the only serotype consistently higher in North American populations relative to other geographic regions (p Conclusion This study establishes PCR-based serotyping as a viable strategy for GBS epidemiological surveillance. Our results suggest that GBS seroprevalence remains stable in North America over the past two decades.
Full Text Available Prevalence of pneumococcal serotypes in carriage and disease has been described but absolute serotype colonisation densities have not been reported. 515 paediatric nasal swab DNA extracts were subjected to lytA qPCR and molecular serotyping by microarray. Absolute serotype densities were derived from total pneumococcal density (qPCR cycle threshold and standard curve and relative abundance (microarray and varied widely. Compared to all serotype densities observed, the strongest evidence of differences was seen for serotypes 21 and 35B (higher and 3, 38 and non-typeables (lower (p<0.05 with a similar hierarchy when only a single serotype carriage was assessed. There was no evidence of any overall density differences between children with single or multiple serotypes detected but serotypes with mid-range densities were more prevalent. The hierarchy of distinct pneumococcal serotype carriage densities described here for the first time, may help explain the dynamics of transmission between children.
SACCHI Claudio Tavares
Full Text Available In the present study we examine the potential use of oligonucleotide probes to characterize Neisseria meningitidis serotypes without the use of monoclonal antibodies (MAbs. Antigenic diversity on PorB protein forms the bases of serotyping method. However, the current panel of MAbs underestimated, by at least 50% the PorB variability, presumably because reagents for several PorB variable regions (VRs are lacking, or because a number of VR variants are not recognized by serotype-defining MAbs12. We analyzed the use of oligonucleotide probes to characterize serotype 10 and serotype 19 of N. meningitidis. The porB gene sequence for the prototype strain of serotype 10 was determined, aligned with 7 other porB sequences from different serotypes, and analysis of individual VRs were performed. The results of DNA probes 21U (VR1-A and 615U (VR3-B used against 72 N. meningitidis strains confirm that VR1 type A and VR3 type B encode epitopes for serotype-defined MAbs 19 and 10, respectively. The use of probes for characterizing serotypes possible can type 100% of the PorB VR diversity. It is a simple and rapid method specially useful for analysis of large number of samples.
Sluijs, van der M.T.W.; Schroer-Joosten, D.P.H.; Fid-Fourkour, A.; Vrijenhoek, M.P.; Debyser, I.; Moulin, V.; Moormann, R.J.M.; Smit, de A.J.
The Bluetongue virus serotype 8 (BTV-8) strain, which emerged in Europe in 2006, had an unusually high ability to cause foetal infection in pregnant ruminants. Other serotypes of BTV had already been present in Europe for more than a decade, but transplacental transmission of these strains had never
Narender S Maan
Full Text Available Bluetongue (BT is an arthropod-borne viral disease, which primarily affects ruminants in tropical and temperate regions of the world. Twenty six bluetongue virus (BTV serotypes have been recognised worldwide, including nine from Europe and fifteen in the United States. Identification of BTV serotype is important for vaccination programmes and for BTV epidemiology studies. Traditional typing methods (virus isolation and serum or virus neutralisation tests (SNT or VNT are slow (taking weeks, depend on availability of reference virus-strains or antisera and can be inconclusive. Nucleotide sequence analyses and phylogenetic comparisons of genome segment 2 (Seg-2 encoding BTV outer-capsid protein VP2 (the primary determinant of virus serotype were completed for reference strains of BTV-1 to 26, as well as multiple additional isolates from different geographic and temporal origins. The resulting Seg-2 database has been used to develop rapid (within 24 h and reliable RT-PCR-based typing assays for each BTV type. Multiple primer-pairs (at least three designed for each serotype were widely tested, providing an initial identification of serotype by amplification of a cDNA product of the expected size. Serotype was confirmed by sequencing of the cDNA amplicons and phylogenetic comparisons to previously characterised reference strains. The results from RT-PCR and sequencing were in perfect agreement with VNT for reference strains of all 26 BTV serotypes, as well as the field isolates tested. The serotype-specific primers showed no cross-amplification with reference strains of the remaining 25 serotypes, or multiple other isolates of the more closely related heterologous BTV types. The primers and RT-PCR assays developed in this study provide a rapid, sensitive and reliable method for the identification and differentiation of the twenty-six BTV serotypes, and will be updated periodically to maintain their relevance to current BTV distribution and
Schoevers, E. J.; van Leengoed, L. A. M. G.; Verheijden, J. H. M.; Niewold, T. A.
The interaction between enrofloxacin and porcine phagocytes was studied with clinically relevant concentrations of enrofloxacin. Enrofloxacin accumulated in phagocytes, with cellular concentration/extracellular concentration ratios of 9 for polymorphonuclear leukocytes (PMNs) and 5 for alveolar macrophages (AMs). Cells with accumulated enrofloxacin brought into enrofloxacin-free medium released approximately 80% (AMs) to 90% (PMNs) of their enrofloxacin within the first 10 min, after which no further release was seen. Enrofloxacin affected neither the viability of PMNs and AMs nor the chemotaxis of PMNs at concentrations ranging from 0 to 10 μg/ml. Enrofloxacin (0.5 μg/ml) did not alter the capability of PMNs and AMs to phagocytize fluorescent microparticles or Actinobacillus pleuropneumoniae, Pasteurella multocida, and Staphylococcus aureus. Significant differences in intracellular killing were seen with enrofloxacin at 5× the MIC compared with that for controls not treated with enrofloxacin. PMNs killed all S. aureus isolates in 3 h with or without enrofloxacin. Intracellular S. aureus isolates in AMs were less susceptible than extracellular S. aureus isolates to the bactericidal effect of enrofloxacin. P. multocida was not phagocytosed by PMNs. AMs did not kill P. multocida, and similar intra- and extracellular reductions of P. multocida isolates by enrofloxacin were found. Intraphagocytic killing of A. pleuropneumoniae was significantly enhanced by enrofloxacin at 5× the MIC in both PMNs and AMs. AMs are very susceptible to the A. pleuropneumoniae cytotoxin. This suggests that in serologically naive pigs the enhancing effect of enrofloxacin on the bactericidal action of PMNs may have clinical relevance. PMID:10471554
Pfaller, M A; Jones, R N; Walter, D H
Quality control guidelines for standardized antimicrobial susceptibility test methods are critical for the continuing accuracy of these clinical tests. In this report, quality control limits were proposed for the veterinary antimicrobial agent tiamulin with minimum inhibitory concentration (MIC) ranges of three or four log(2) dilution steps in two different medium formulations. Disk diffusion zone diameter ranges were proposed for tiamulin tested against Actinobacillus pleuropneumoniae ATCC 27090 (12-18 mm) and Staphylococcus aureus ATCC 25923 (25-32 mm). The data from eight participating laboratories produced 100% of results within proposed MIC limits (8-32 microg/mL), and 95.8-97.0% of zones were found within suggested zone diameter QC guidelines. These proposed QC ranges should be validated by in-use results from veterinary clinical laboratories.
Nicholas J Croucher
Full Text Available Streptococcus pneumoniae isolates typically express one of over 90 immunologically distinguishable polysaccharide capsules (serotypes, which can be classified into "serogroups" based on cross-reactivity with certain antibodies. Pneumococci can alter their serotype through recombinations affecting the capsule polysaccharide synthesis (cps locus. Twenty such "serotype switching" events were fully characterised using a collection of 616 whole genome sequences from systematic surveys of pneumococcal carriage. Eleven of these were within-serogroup switches, representing a highly significant (p < 0.0001 enrichment based on the observed serotype distribution. Whereas the recombinations resulting in between-serogroup switches all spanned the entire cps locus, some of those that caused within-serogroup switches did not. However, higher rates of within-serogroup switching could not be fully explained by either more frequent, shorter recombinations, nor by genetic linkage to genes involved in β-lactam resistance. This suggested the observed pattern was a consequence of selection for preserving serogroup. Phenotyping of strains constructed to express different serotypes in common genetic backgrounds was used to test whether genotypes were physiologically adapted to particular serogroups. These data were consistent with epistatic interactions between the cps locus and the rest of the genome that were specific to serotype, but not serogroup, meaning they were unlikely to account for the observed distribution of capsule types. Exclusion of these genetic and physiological hypotheses suggested future work should focus on alternative mechanisms, such as host immunity spanning multiple serotypes within the same serogroup, which might explain the observed pattern.
Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck
In French Guiana, a French overseas territory located in the South American northern coast, nearly 50% of Salmonella serotypes isolated from human infections belong to serotypes rarely encountered in metropolitan France. A reptilian source of contamination has been investigated. Between April and June 2011, in the area around Cayenne, 151 reptiles were collected: 38 lizards, 37 snakes, 32 turtles, 23 green iguanas and 21 caimans. Cloacal swab samples were collected and cultured. Isolated Salmonella strains were identified biochemically and serotyped. The overall carriage frequency of carriage was 23.2% (95% confidence interval: 16.7-30.4) with 23 serotyped strains. The frequency of Salmonella carriage was significantly higher for wild reptiles. Near two-thirds of the Salmonella serotypes isolated from reptiles were also isolated from patients in French Guiana. Our results highlight the risk associated with the handling and consumption of reptiles and their role in the spread of Salmonella in the environment. Copyright © 2014 Elsevier B.V. All rights reserved.
Full Text Available Objective: Streptococcus agalactiae (Group B streptococci, GBS are frequently responsible for sepsis and meningitis seen in the early weeks of life. GBS may cause perinatal infection and premature birth in pregnant women. The aim of this study was to serotype GBS strains isolated from clinical samples and evaluate their serotype distribution according to their susceptibilities to antibiotics and isolation sites. Material and Methods: One hundred thirty one S. agalactiae strains isolated from the clinical samples were included in the study. Of the strains, 99 were isolated from urine, 20 from soft tissue, 10 from blood and 2 from vaginal swab. Penicillin G and ceftriaxone susceptibilities of GBS were determined by the agar dilution method. Susceptibilities to erythromycin, clindamycin, vancomycin and tetracycline were determined by the Kirby-Bauer method according to CLSI criteria. Serotyping was performed using the latex aglutination method using specific antisera (Ia, Ib, II-VIII. Results: While in 131 GBS strains, serotypes VII and VIII were not detected, the most frequently isolated serotypes were types Ia (36%, III (30.5% and II (13% respectively. Serotype Ia was the most frequently seen serotype in all samples. All GBS isolates were susceptible to penicilin G, ceftriaxone and vancomycin. Among the strains, tetracycline, erythromycin and clindamycin resistance rates were determined as 90%, 14.5%, and 13% respectively. Conclusion: Penicillin is still the first choice of treatment for the infections with all serotypes of S. agalactiae in Turkey.
Dayao, Denise Ann Estarez; Seddon, Jennifer M; Gibson, Justine S; Blackall, Patrick J; Turni, Conny
Macrolides are often used to treat and control bacterial pathogens causing respiratory disease in pigs. This study analyzed the whole genome sequences of one clinical isolate of Actinobacillus pleuropneumoniae, Haemophilus parasuis, Pasteurella multocida, and Bordetella bronchiseptica, all isolated from Australian pigs to identify the mechanism underlying the elevated minimum inhibitory concentrations (MICs) for erythromycin, tilmicosin, or tulathromycin. The H. parasuis assembled genome had a nucleotide transition at position 2059 (A to G) in the six copies of the 23S rRNA gene. This mutation has previously been associated with macrolide resistance but this is the first reported mechanism associated with elevated macrolide MICs in H. parasuis. There was no known macrolide resistance mechanism identified in the other three bacterial genomes. However, strA and sul2, aminoglycoside and sulfonamide resistance genes, respectively, were detected in one contiguous sequence (contig 1) of A. pleuropneumoniae assembled genome. This contig was identical to plasmids previously identified in Pasteurellaceae. This study has provided one possible explanation of elevated MICs to macrolides in H. parasuis. Further studies are necessary to clarify the mechanism causing the unexplained macrolide resistance in other Australian pig respiratory pathogens including the role of efflux systems, which were detected in all analyzed genomes.
Lauderdale, T. L.; Aarestrup, Frank Møller; Chen, P. C.
(41%) and was highly prevalent in Salmonella enterica serotype Typhimurium (72.7%, 176/242) the most common serotype. Additional resistance to trimethoprim was present in 155 (19.4% overall) of the ACSSuT R-type isolates from several serotypes. Reduced susceptibility to fluoroquinolone (FQ...... multiresistant to other antimicrobials. Studies are needed to determine the sources of different multidrug-resistant serotypes. Continued national surveillance is underway to monitor changes in resistance trends and to detect further emergence of resistant Salmonella serotypes in Taiwan. (c) 2006 Elsevier Inc...
Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Anandan, Shalini; Walia, Kamini; Veeraraghavan, Balaji
It is not always possible to identify Shigella serogroups/serotypes by biochemical properties alone. Specific identification requires serotyping. Occasionally, isolates that resemble Shigella spp. biochemically, but are non-agglutinable with available antisera, have been observed. Several mechanisms have been reported to limit the efficiency of the serotyping assay. Serotype conversion is a major mechanism in Shigella spp. to escape protective host immune responses. This easy conversion through significant modification of the O-antigen backbone results in different serotypes, which makes laboratory identification difficult. Furthermore, members of the family Enterobacteriaceae are closely related and there is antigenic cross-over (intra- and inter-specific cross-reaction) which affects the agglutination reaction. The performance of the available methods for identification of non-serotypeable Shigella is discussed here, and reveals them to be non-reliable. This shows a need for an alternative method for identification and typing of Shigella spp.
Spencer, Brady L; Shenoy, Anukul T; Orihuela, Carlos J; Nahm, Moon H
As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acetyltransferase gene wciZ The coding sequence of wciZ contains eight consecutive TA repeats [(TA) 8 ]. Replication slippage is thought to result in the addition or loss of TA repeats, subsequently causing frameshift and truncation of WciZ to yield a nonacetylated serotype, 15C. Using sensitive serological tools, we show that serotype 15C isolates whose wciZ contains seven or nine TA repeats retain partial O-acetylation, while serotype 15C isolates whose wciZ contains six TA repeats have barely detectable O-acetylation. We confirmed by inhibition enzyme-linked immunosorbent assay that (TA) 7 serotype 15C is ∼0.1% as acetylated as serotype 15B, while serotype 15X is nonacetylated. To eliminate the impact of genetic background, we created isogenic serotype 15B, (TA) 7 serotype 15C, and 15BΔ wciZ (15X) strains and found that reduction or absence of WciZ-mediated O-acetylation did not affect capsular shielding from phagocytes, biofilm formation, adhesion to nasopharyngeal cells, desiccation tolerance, or murine colonization. Sera from PPV23-immunized persons opsonized serotype 15B significantly but only slightly better than serotypes 15C and 15X; thus, PPV23 may not result in expansion of serotype 15C. Copyright © 2017 American Society for Microbiology.
Bello Gonzalez, Teresita; Rivera-Olivero, Ismar Alejandra; Sisco, María Carolina; Spadola, Enza; Hermans, Peter W; de Waard, Jacobus H
Serotype surveillance of Streptococcus pneumoniae is indispensable for evaluating the potential impact of pneumococcal conjugate vaccines. Serotyping by the standard Quellung reaction is technically demanding, time consuming, and expensive. A simple and economical strategy is multiplex PCR-based serotyping. We evaluated the cost effectiveness of a modified serial multiplex PCR (mPCR), resolving 24 serotypes in four PCR reactions and optimally targeting the most prevalent invasive and colonizing pneumococcal serotypes found in Venezuela. A total of 223 pneumococcal isolates, 140 invasive and 83 carriage isolates, previously serotyped by the Quellung reaction and representing the 18 most common serotypes/groups identified in Venezuela, were serotyped with the adapted mPCR. The mPCR serotyped 76% of all the strains in the first two PCR reactions and 91% after four reactions, correctly identifying 17 serotypes/groups. An isolate could be serotyped with mPCR in less than 2 minutes versus 15 minutes for the Quellung reaction, considerably lowering labor costs. A restrictive weakness of mPCR was found for the detection of 19F strains. Most Venezuelan 19F strains were not typeable using the mPCR, and two 19F cps serotype variants were identified. The mPCR assay is an accurate, rapid, and economical method for the identification of the vast majority of the serotypes from Venezuela and can be used in place of the standard Quellung reaction. An exception is the identification of serotype 19F. In this setting, most 19F strains were not detectable with mPCR, demonstrating a need of serology-based quality control for PCR-based serotyping.
Muthuirulandi Sethuvel, D P; Devanga Ragupathi, N K; Anandan, S; Veeraraghavan, B
Shigellosis represents a major burden of disease in developing countries. A low infectious dose allows the disease to be spread effectively. Although shigellosis is mostly a self-limiting disease, antibiotics are recommended to reduce deaths, disease symptoms and organism-shedding time. However, in India, antimicrobial resistance among the genus Shigella is more common than among any other enteric bacteria. Notably, new serotypes or subserotypes in Shigella are reported from various parts of the world. Identification of new subserotypes of Shigella spp. is becoming a major issue as these strains are nontypeable by conventional serotyping. The commercially available antisera may not cover all possible epitopes of the O lipopolysaccharide antigen of Shigella serotypes. Therefore, molecular methods which most closely approach the resolution of full serotyping are necessary to identify such strains. In addition, the knowledge of a prevalent serotype in various geographic regions may assist in formulating strategies such as the development of a vaccine to prevent infection especially when the immunity to disease is serotype specific, and to understand the disease burden caused by new Shigella serotypes. © 2016 The Society for Applied Microbiology.
Muhammad Masroor Alam
Full Text Available Astroviruses are globally known enteropathogens causing gastroenteritis and diarrhea, with eight well defined serotypes. Epidemiological studies have recognized serotype-1 as the most common subtype but no such data is available in Pakistan. During 2009-2010, we found astroviruses in 41 out of 535 (7% samples collected from hospitalized children. Thirty one strains belonged to serotype-1 and clustered into two distinct lineages. Serotype-3, -4 and -6 were detected with 97-98% genetic homology to Indian and Chinese strains.
Full Text Available Lung abscess has been considered to be a rare complication of pneumococcal infection, and most cases are reported to be Streptococcus pneumoniae serotype 3. A 67-year-old man presented with fever and was diagnosed to have lung abscess caused by S. pneumoniae serotype 6B. The minimal inhibitory concentration (MIC of penicillin for the isolate was 1 μg/mL. He was treated with high-dose intravenous sulbactam/ampicillin as definitive therapy based on susceptibility testing for S. pneumoniae and recovered successfully without surgical intervention. S. pneumoniae serotype 6B can cause lung abscess. Keywords: Streptococcus pneumoniae, Lung abscess, Serotype 6B, Penicillin-resistant Streptococcus pneumoniae
Thompson, Kimberly M; Duintjer Tebbens, Radboud J
Comparing model expectations with the experience of oral poliovirus vaccine (OPV) containing serotype 2 (OPV2) cessation can inform risk management for the expected cessation of OPV containing serotypes 1 and 3 (OPV13). We compare the expected post-OPV2-cessation OPV2-related viruses from models with the evidence available approximately 6 months after OPV2 cessation. We also model the trade-offs of use vs nonuse of monovalent OPV (mOPV) for outbreak response considering all 3 serotypes. Although too early to tell definitively, the observed die-out of OPV2-related viruses in populations that attained sufficiently intense trivalent OPV (tOPV) use prior to OPV2 cessation appears consistent with model expectations. As expected, populations that did not intensify tOPV use prior to OPV2 cessation show continued circulation of serotype 2 vaccine-derived polioviruses (VDPVs). Failure to aggressively use mOPV to respond to circulating VDPVs results in a high risk of uncontrolled outbreaks that would require restarting OPV. Ensuring a successful endgame requires more aggressive OPV cessation risk management than has occurred to date for OPV2 cessation. This includes maintaining high population immunity to transmission up until OPV13 cessation, meeting all prerequisites for OPV cessation, and ensuring sufficient vaccine supply to prevent and respond to outbreaks. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.
Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca
. aeruginosa O12 OSA gene cluster, an antibiotic resistance determinant (gyrAC248T), and other genes that have been transferred between P. aeruginosa strains with distinct core genome architectures. We showed that these genes were likely acquired from an O12 serotype strain that is closely related to P...... in clinical settings and outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics. Here, we explore how the P. aeruginosa OSA biosynthesis gene clusters evolve in the population by investigating the association between the phylogenetic relationships among 83 P....... aeruginosa strains and their serotypes. While most serotypes were closely linked to the core genome phylogeny, we observed horizontal exchange of OSA biosynthesis genes among phylogenetically distinct P. aeruginosa strains. Specifically, we identified a "serotype island" ranging from 62 kb to 185 kb containing the P...
Zheng, Zhibei; Zheng, Wei; Wang, Haoqiu; Pan, Jincao; Pu, Xiaoying
Currently, no protocols or commercial kits are available to determine the serotypes of Salmonella by using Luminex MAGPIX®. In this study, an xTAG assay for serotype determination of Salmonella suitable for Luminex MAGPIX® is described and 228 Salmonella isolates were serotype determined by this xTAG assay. The xTAG assay consists of two steps: 1) Multiplex PCR to amplify simultaneously O, H and Vi antigen genes of Salmonella, and 2) Magplex-TAG™ microsphere hybridization to identify accurately the specific PCR products of different antigens. Compared with the serotyping results of traditional serum agglutination test, the sensitivity and specificity of the xTAG assay were 95.1% and 100%, respectively. The agreement rate of these two assays was 95.2%. Compared with Luminex xMAP® Salmonella Serotyping Assay (SSA) kit, the advantages of this xTAG assay are: First, the magnetic beads make it applicable to both the Luminex®100/200™ and MAGPIX® systems. Second, only primers rather than both primers and probes are needed in the xTAG assay, and the process of coupling antigen-specific oligonucleotide probes to beads is circumvented, which make the xTAG assay convenient to be utilized by other laboratories. The xTAG assay may serve as a rapid alternative or complementary method for traditional Salmonella serotyping tests, especially for laboratories that utilize the MAGPIX® systems. Copyright © 2017 Elsevier B.V. All rights reserved.
Newton, Richard; Wernisch, Lorenz
Streptococcus pneumoniae is a human pathogen that is a major cause of infant mortality. Identifying the pneumococcal serotype is an important step in monitoring the impact of vaccines used to protect against disease. Genomic microarrays provide an effective method for molecular serotyping. Previously we developed an empirical Bayesian model for the classification of serotypes from a molecular serotyping array. With only few samples available, a model driven approach was the only option. In the meanwhile, several thousand samples have been made available to us, providing an opportunity to investigate serotype classification by machine learning methods, which could complement the Bayesian model. We compare the performance of the original Bayesian model with two machine learning algorithms: Gradient Boosting Machines and Random Forests. We present our results as an example of a generic strategy whereby a preliminary probabilistic model is complemented or replaced by a machine learning classifier once enough data are available. Despite the availability of thousands of serotyping arrays, a problem encountered when applying machine learning methods is the lack of training data containing mixtures of serotypes; due to the large number of possible combinations. Most of the available training data comprises samples with only a single serotype. To overcome the lack of training data we implemented an iterative analysis, creating artificial training data of serotype mixtures by combining raw data from single serotype arrays. With the enhanced training set the machine learning algorithms out perform the original Bayesian model. However, for serotypes currently lacking sufficient training data the best performing implementation was a combination of the results of the Bayesian Model and the Gradient Boosting Machine. As well as being an effective method for classifying biological data, machine learning can also be used as an efficient method for revealing subtle biological
Yiltawe Simwal Wungak
Full Text Available Aim: This study aimed to determine the foot-and-mouth disease virus (FMDV serotypes circulating, the prevalence of FMDV serotypes, and the spatial distribution of FMDV among sedentary and pastoral cattle herds in the North-Central Nigeria. Materials and Methods: A cross-sectional study was undertaken, during which a total of 155 sera that tested positive for foot-and-mouth disease (FMD 3ABC non-structural protein antibodies were selected and screened for FMD structural protein serotypes, A, O, SAT 1, and SAT 2 using a solid-phase competitive enzyme-linked immunosorbent assay (ELISA. Epithelial tissue specimens were collected during outbreak investigations which were tested for FMD using an antigen capture ELISA for serotype A, O, SAT 1, and SAT 2. Results: An overall serotype-specific prevalence of 79.35 (95% confidence interval [CI]: 72.4-85.18 was recorded for serotype O, 65.2% (95% CI: 57.41-72.3 for serotype A, 52.9% (95% CI: 45.03-60.67 for SAT-2, and 33.55% (95% CI: 26.45-41.26 for SAT-1. Evidence of exposure to multiple FMDV serotypes showed that 12.26% of the sera samples had antibodies against four serotypes circulating, 30.97% had antibodies against three serotypes circulating, 22.58% had antibodies against two serotypes, and 17% showed exposure to only one serotype. Clinical specimens (epithelial tissue collected during outbreak investigations showed that serotype O has the highest proportion of 50% with serotype A - 25%; SAT 2 - 20.8%; and SAT 1 - 4.1%. Conclusion: The study detected diffuse and co-circulation of serotypes A, O, SAT1, and SAT2 within the study area, and hence the need for the appropriately matched multivalent vaccine is strongly advocated for FMD control in Nigeria.
Halsey, Eric S.; Marks, Morgan A.; Gotuzzo, Eduardo; Fiestas, Victor; Suarez, Luis; Vargas, Jorge; Aguayo, Nicolas; Madrid, Cesar; Vimos, Carlos; Kochel, Tadeusz J.; Laguna-Torres, V. Alberto
Background Disease caused by the dengue virus (DENV) is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype. Methodology and Principal Findings Between the years 2005–2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%), DENV-2 (4.3%), DENV-3 (41.5%), or DENV-4 (14.4%). When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations. Conclusions/Significance Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype. PMID:22563516
Eric S Halsey
Full Text Available Disease caused by the dengue virus (DENV is a significant cause of morbidity throughout the world. Although prior research has focused on the association of specific DENV serotypes (DENV-1, DENV-2, DENV-3, and DENV-4 with the development of severe outcomes such as dengue hemorrhagic fever and dengue shock syndrome, relatively little work has correlated other clinical manifestations with a particular DENV serotype. The goal of this study was to estimate and compare the prevalence of non-hemorrhagic clinical manifestations of DENV infection by serotype.Between the years 2005-2010, individuals with febrile disease from Peru, Bolivia, Ecuador, and Paraguay were enrolled in an outpatient passive surveillance study. Detailed information regarding clinical signs and symptoms, as well as demographic information, was collected. DENV infection was confirmed in patient sera with polyclonal antibodies in a culture-based immunofluorescence assay, and the infecting serotype was determined by serotype-specific monoclonal antibodies. Differences in the prevalence of individual and organ-system manifestations were compared across DENV serotypes. One thousand seven hundred and sixteen individuals were identified as being infected with DENV-1 (39.8%, DENV-2 (4.3%, DENV-3 (41.5%, or DENV-4 (14.4%. When all four DENV serotypes were compared with each other, individuals infected with DENV-3 had a higher prevalence of musculoskeletal and gastrointestinal manifestations, and individuals infected with DENV-4 had a higher prevalence of respiratory and cutaneous manifestations.Specific clinical manifestations, as well as groups of clinical manifestations, are often overrepresented by an individual DENV serotype.
Full Text Available An unusual case of pleural empyema related to Nocardia farcinica and Ureaplasma urealyticum, occurring after autologous haematopoietic stem cell transplantation in a 30-year-old patient with lymphoma, is reported. This case illustrates the role of repeated and comprehensive microbiological investigations and the contribution of molecular techniques in reaching the aetiological diagnosis. Keywords: Nocardia farcinica, Ureaplasma urealyticum, Pleuropneumonia, Immunocompromised patient, Molecular microbiological diagnosis
Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca
that serotype switching in combination with an antibiotic resistance determinant contributed to the dissemination of the O12 serotype in the clinic. This selective advantage coincides with the introduction of fluoroquinolones in the clinic. With the PAst program isolates can be serotyped using WGS data......Introduction: Since the 1980’s the serotype O12 of Pseudomonas aeruginosa has emerged as the predominant serotype in clinical settings and in epidemic outbreaks. These serotype O12 isolates exhibit high levels of resistance to various classes of antibiotics.Methods: In this study, we explore how......).Results: While most serotypes were closely linked to the core genome phylogeny we observed horizontal exchange of LPS genes among distinct P. aeruginosa strains. Specifically, we identified a ‘serotype island’ containing the P. aeruginosa O12 LPS gene cluster and an antibiotic resistance determinant (gyrAC248T...
van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J
Salmonella serotype distribution can give insight in contamination routes and persistence along a production chain. Therefore, it is important to determine not only Salmonella prevalence but also to specify the serotypes involved at the different stages of the supply chain. For this purpose, data from a national monitoring program in the Netherlands were used to estimate the serotype distribution and to determine whether this distribution differs for the available sampling points in the broiler supply chain. Data covered the period from 2002 to 2005, all slaughterhouses (n = 22), and the following 6 sampling points: departure from hatchery, arrival at the farm, departure from the farm, arrival at the slaughterhouse, departure from the slaughterhouse, and end of processing. Furthermore, retail data for 2005 were used for comparison with slaughterhouse data. The following serotypes were followed throughout the chain: Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Paratyphi B var. Java (Salmonella Java), Salmonella Infantis, Salmonella Virchow, and Salmonella Mbandaka. Results showed that serotype distribution varied significantly throughout the supply chain (P supply chain up to the retail phase.
Bailey, J S; Cox, N A; Craven, S E; Cosby, D E
The widespread presence of Salmonella in all phases of broiler chicken production and processing is well documented. However, little information is available to indicate the identity and movement of specific serotypes of Salmonella through the different phases of an integrated operation. In this study, samples were collected from the breeder farm, from the hatchery, from the previous grow-out flock, from the flock during grow-out, and from carcasses after processing. Salmonella were recovered from 6, 98, 24, 60, and 7% of the samples, respectively, in the first trial and from 7, 98, 26, 22, and 36% of the samples, respectively, in the second trial. Seven different serotypes were identified in the first trial, and 12 different serotypes were identified in the second trial. For both trials there was poor correlation between the serotypes found in the breeder farms and those found in the hatchery. This finding and the fact that similar serotypes were found in the hatchery in both trials suggests that there was an endemic population of Salmonella in the hatchery. An association between the serotypes found in the hatchery and those found on the final processed carcasses was observed in both trials. This study confirms that a successful intervention program for broiler production operations must be multifaceted, with one component being disinfection in the hatchery.
Firacative, Carolina; Torres, Germán; Rodríguez, María Claudia; Escandón, Patricia
In Cúcuta, Cryptococcus gattii serotype B is commonly recovered from immunocompetent patients with cryptococcosis, but it has not been recovered from the environment in spite of its high incidence which is 77% out of reported cases. The aim of this work was to carry out an extensive environmental sampling in Cúcuta, in an attempt to isolate C. gattii serotype B and to expand our knowledge about the ecology and epidemiology of this important yeast. Samples associated with 3,634 trees from 40 zones of Cúcuta were collected and processed with 28 samples collected near the houses of four patients with cryptococcosis caused by C. gattii serotype B. The serotype of the recovered isolates was done using multiplex PCR, molecular patterns were determined by RFLP of the URA5 gene and mating type was determined using the primers MfÎ±U, MfÎ±L, MFa2U and MFa2L. In total, 4,389 samples were processed and one isolate of C. gattii serotype B (VGI/a), two isolates of C. gattii serotype C (VGIII/Î±) and three isolates of C. neoformans var. grubii, serotype A (VNI/Î±), were recovered. The density of the recovered isolates varied from 50 to 350 cfu/g of soil. This is the first report on the environmental isolation of C. gattii serotype B from Cúcuta. However, because of the low rate of recovery of isolates from soil only, the environmental niche of C. gattii has not been established and further environmental studies in Cúcuta are necessary, owing that this serotype is not only causing cryptococcosis but also has shown a higher virulence after the Vancouver outbreak.
Spanjaard, L.; Bol, P.; de Marie, S.; Zanen, H. C.
Case histories of 692 patients with meningococcal disease due to serogroup B, C, or W (W-135) were reviewed to study the association of the serotypes 2a and 2b with the course of disease. The case-fatality rate in group B disease was significantly associated with serotype 2b (B:2b) strains (P =
Fabrine Alexandre dos Santos
Full Text Available The present study reports the first isolation of Actinobacillus seminis from a goat in Brazil. A four-year-old Moxotó breeding goat in a flock of 70 goats and 65 sheep reared together in the county of Patos, semiarid region of Northeastern Brazil, showed clinical signs of unilateral orchitis and epididymitis. Diagnosis of A. seminis infection was confirmed by association of clinical findings, bacterial isolation and 16S rRNA gene sequencing. This result suggests that A. seminis may be an additional cause of infertility in goats, and that sheep may be the source of infection because the mixed farming system allows the contact between sheep and goats in the semiarid region of Northeastern Brazil.
Masiga, W N; Domenech, J
Contagious bovine pleuropneumonia (CBPP) is widespread in Africa and in other regions of the world. This disease is particularly important in the semi-arid, sub-humid and arid zones of tropical Africa, but CBPP incidence seems to be increasing in some parts of East Africa. The epidemiology of CBPP is characterised by the occurrence of sub-acute and symptomless infections, and the persistence of chronic carriers. Spread of the disease is associated with cattle movement. The major obstacles to eradication of CBPP are the difficulties in controlling cattle movement and applying quarantine and slaughter policies. Other difficulties arise due to the absence of a field test for diagnosis, the relatively short duration of post-vaccinal immunity and the lack of data on the economic impact of the disease. The Pan-African Rinderpest Campaign strategy for CBPP control and eradication conforms with national control programmes, which include cost/benefit analysis. It is planned to perform blanket vaccination against the disease for three to five years, depending on the economic situation of each country. Stringent control of cattle movement will complement vaccination campaigns. The eradication phase, including slaughter measures, will be instituted following reduction of CBPP incidence. Regional and international coordination will be instituted to control international cattle movement and harmonise control strategies.
de Jong, Anno; Thomas, Valérie; Simjee, Shabbir; Moyaert, Hilde; El Garch, Farid; Maher, Kirsty; Morrissey, Ian; Butty, Pascal; Klein, Ulrich; Marion, Hervé; Rigaut, Delphine; Vallé, Michel
VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme collecting pathogens from diseased antimicrobial non-treated cattle, pigs and poultry. In the current study, 1001 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 11 countries during 2002-2006. Pasteurella multocida and Mannheimia haemolytica from cattle and P. multocida, Actinobacillus pleuropneumoniae and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MICs of 16 antibiotics were assessed centrally by broth microdilution following CLSI recommendations. Results were interpreted using CLSI breakpoints where available. P. multocida (231) and M. haemolytica (138) isolates were all susceptible to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin and trimethoprim/sulfamethoxazole. Resistance to florfenicol and spectinomycin was 0.4% and 3.5% in P. multocida, respectively, and absent in M. haemolytica isolates. Tetracycline resistance was 5.7% and 14.6% for P. multocida and M. haemolytica. In pigs, 230 P. multocida, 220 A. pleuropneumoniae and 182 S. suis isolates were recovered. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tiamulin and tilmicosin was absent or <1%. Trimethoprim/sulfamethoxazole resistance was 3-6% and tetracycline resistance varied from 14.7% in A. pleuropneumoniae to 81.8% in S. suis. In conclusion, low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from cattle and pigs. Since for approximately half of the antibiotics in this panel no CLSI-defined breakpoints were available, setting of the missing veterinary breakpoints is important. Copyright © 2014 Elsevier B.V. All rights reserved.
Ito, Yuhei; Toyoshima, Hirokazu; Suzuki, Takehiro; Iwamoto, Keisuke; Sasano, Hajime; Itani, Hidetoshi; Kondo, Shigeto; Tanigawa, Motoaki
Lung abscess has been considered to be a rare complication of pneumococcal infection, and most cases are reported to be Streptococcus pneumoniae serotype 3. A 67-year-old man presented with fever and was diagnosed to have lung abscess caused by S. pneumoniae serotype 6B. The minimal inhibitory concentration (MIC) of penicillin for the isolate was 1 μg/mL. He was treated with high-dose intravenous sulbactam/ampicillin as definitive therapy based on susceptibility testing for S. pneumoniae and recovered successfully without surgical intervention. S. pneumoniae serotype 6B can cause lung abscess.
The 7-valent pneumococcal conjugate vaccine (PCV7) was included in the routine infant immunization schedule in Ireland in September 2008. We determined the serotype of 977 S. pneumoniae isolates causing invasive disease between 2000-2002 and 2007-2008, assessed for the presence of the recently described serotype 6C and determined the susceptibility of isolates during 2007-2008 to penicillin and cefotaxime. Serotype 14 was the most common serotype during both periods and 7·7% of isolates previously typed as serotype 6A were serotype 6C. During 2000-2002 and 2007-2008, PCV7 could potentially have prevented 85% and 74% of invasive pneumococcal disease in the target population (i.e. children aged <2 years), respectively. The level of penicillin non-susceptibility was 17% in 2007-2008. Ongoing surveillance of serotypes is required to determine the impact of PCV7 in the Irish population and to assess the potential of new vaccines with expanded valency.
Samir K Saha
Full Text Available BACKGROUND: Streptococcus pneumoniae is a leading cause of meningitis in countries where pneumococcal conjugate vaccines (PCV targeting commonly occurring serotypes are not routinely used. However, effectiveness of PCV would be jeopardized by emergence of invasive pneumococcal diseases (IPD caused by serotypes which are not included in PCV. Systematic hospital based surveillance in Bangladesh was established and progressively improved to determine the pathogens causing childhood sepsis and meningitis. This also provided the foundation for determining the spectrum of serotypes causing IPD. This article reports an unprecedented upsurge of serotype 2, an uncommon pneumococcal serotype, without any known intervention. METHODS AND FINDINGS: Cases with suspected IPD had blood or cerebrospinal fluid (CSF collected from the beginning of 2001 till 2009. Pneumococcal serotypes were determined by capsular swelling of isolates or PCR of culture-negative CSF specimens. Multicenter national surveillance, expanded from 2004, identified 45,437 patients with suspected bacteremia who were blood cultured and 10,618 suspected meningitis cases who had a lumber puncture. Pneumococcus accounted for 230 culture positive cases of meningitis in children <5 years. Serotype-2 was the leading cause of pneumococcal meningitis, accounting for 20.4% (45/221; 95% CI 15%-26% of cases. Ninety eight percent (45/46 of these serotype-2 strains were isolated from meningitis cases, yielding the highest serotype-specific odds ratio for meningitis (29.6; 95% CI 3.4-256.3. The serotype-2 strains had three closely related pulsed field gel electrophoresis types. CONCLUSIONS: S. pneumoniae serotype-2 was found to possess an unusually high potential for causing meningitis and was the leading serotype-specific cause of childhood meningitis in Bangladesh over the past decade. Persisting disease occurrence or progressive spread would represent a major potential infection threat since serotype-2
Ashshi, Ahmed Mohamed
Transmission of dengue virus (DENV) through blood transfusion has been documented and hence screening for DENV during blood donation has been recently recommended by the American Association of Blood Banks and Centres of Disease Control and Prevention. DENV is endemic in the Western province of the Kingdom of Saudi Arabia (KSA) and serotypes 1, 2 and 3, but not 4, have been detected. However, little is known regarding the rates of DENV during blood donation in the kingdom. The aim of this study was therefore to measure the prevalence of dengue virus and its serotypes in eligible Saudi blood donors in the endemic Western region of KSA. This was a cross-sectional study and serum samples were collected from 910 eligible Saudi male blood donors. DENV IgM and IgG antibodies were measured serologically by ELISA while viral serotypes were detected by a single step IVD CE certified multiplex RT-PCR kit. The overall prevalence was 39 and 5.5% for IgG+ and IgM+, respectively. There were 12 (1.3%) with exclusively IgM+, 317 (34.8%) exclusively IgG+ and 38 (4.2%) with dual IgM+/IgG+ donors. The overall prevalence was 3.2% (n = 29) and 2.3% (n = 21) for primary and secondary infections. PCR was positive in 5.5% (n = 50) and, DENV-2 (n = 24; 48%) was the most frequent serotype and was significantly higher than DENV-1 (20%; P = 0.02) and DENV-3 (2%; P = 0.1 × 10 -5 ) but not DENV-4 (30%; P = 0.2). There was no significant difference between both DENV-4 and DENV-1 (P = 0.4). The combination of the PCR and serology findings showed that 22 (2.4%) and 28 (3.1%) donors had primary and secondary viremic infections, respectively. The detected rates of DENV by PCR suggest a potential high risk of viral transmission by blood transfusion. To the best of our knowledge, this study is the first to report the detection of DENV-4 serotype in Saudi Arabia. More studies are required to measure the precise prevalence of DENV serotypes and their potential
Gatti, B M; Ramirez Gronda, G A; Etchevarría, M; Vescina, C M; Varea, A M; González Ayala, S E
Haemophilus influenzae (Hi) is the causative agent of several human diseases such as sepsis, meningitis, celulitis, and osteoarthritis. We investigated the isolation of Hi serotypes from sterile sites in sick children. One hundred and seventy nine strains from 146 patients were studied, period 1996-2002, at the Microbiology Laboratory, Hospital de Niños Superiora Sor María Ludovica, Argentina. The serotype distribution was:1 a, 112 b,1 c,1 d, 4 e, 3 f y 24 no typable. Since the beginning of universal Hi b vaccination in 1998, we have observed the fast decrease of serotype b and a relative increase of other serotypes.
Deniz Akgun Karapinar
Full Text Available Aim: In this study, the distribution of serogroup/serotype and antibiotic susceptibility testing of Streptococcus pneumoniae strains, recovered from pediatric and adult patients were evaluated. Material and Method: A total of 80 clinical isolates recovered from 19 pediatric and 61 adult patients were performed by latex aglutination method and antibiotic susceptibility tests in Istanbul University, Istanbul Faculty of Medicine, Medical Microbiology Laboratories. Results: Sixty-two strains (76 %, were serogroup/serotyped and 18 (23 % strains couldn%u2019t serogroup/serotyped. The most frequent identified serogroups were 19, 14, 23, 6, 4 in pediatrics, and 3, 19, 23 and 9 in adults. In adults, serogroups 3, 9, 5, 8, 18, 1, 15 were determined, but these serogroups weren%u2019t found in pediatrics. Vaccine serotypes rates were found as 53 % in pediatric and as 85 % in adults. The serogroups 2, 7, 10, 11, 12, 17, 20, 22, 33 were not detected, which are available in vaccine serotypes. Only 1 (1 % strain was found to exhibit low level resistance to penicillin and high level resistance wasn%u2019t found in any strain. Resistant results for trimethoprim-sulfamethoxazole, erythromycin, chloramphenicol and ofloxacin were found as 45 (56 %, 22 (27.5 %, 7 (9 %, 2 (2.5 %, respectively. All strains were found susceptible to vancomycin, linezolid and levofloxacin. The most resistant serogroups were 19, 23, 9 and 14 in the tested antibiotics. Multidrug resistance was found in 9 (11 % strains and these strains were found as serogroups 19, 23, 9, 6 and 14. Discussion: The epidemiological studies are important that the distribution of serotype and antibiotic resistance vary depending on many factors like age, and geographic region.
Chen, Nan; Wang, Lin-Lin; Xue, Juan; Ma, Xiang-Bo; Zhao, Sheng; Rong, Rui-Xue; Li, Hong-Quan; Ding, Liang; Zheng, Ming-Zhi; Chen, Ying-Ying; Duan, Fei; Shen, Yue-Liang
K1 or K2 serotype Klebsiella pneumoniae isolate caused clinical pyogenic liver abscess (KLA) infection is prevalent in many areas. It has been identified that K1 or K2 serotype K. pneumoniae isolates caused KLA infection in mice by oral inoculation. In our study, K1 serotype K. pneumoniae isolate Kp1002 with hypermucoviscosity (HV)-positive phenotype caused KLA infection in C57BL/6 mice by oral inoculation. Simultaneously, non-serotype K1 and K2 isolate Kp1014 with HV-negative phenotype failed to cause KLA infection in the same manner. It seems that gastrointestinal tract translocation is the pathway by which K1 or K2 serotype K. pneumoniae caused KLA infection. Liquid chromatography-tandem mass spectrometry was used to further analyze metabolic profile changes in mice with KLA infection. Data showed that after Kp1002 or Kp1014 oral inoculation, serum Phosphatidylcholine (PC) and Lysophosphatidylcholine (LPC) levels significantly changed in mice. Some PC and LPC molecules showed changes both in the Kp1002 KLA group and the Kp1014 no-KLA group compared with the control group. The level of 18:1/18:2-PC significantly changed in the Kp1002 KLA group compared with the control group, but showed no change between the Kp1014 no-KLA group and the control group. The level of 18:1/18:2-PC might have been particularly affected by KLA infection caused by K1 serotype K. pneumoniae Kp1002. It may be a potential biomarker for KLA infection. Copyright © 2014 Elsevier Ltd. All rights reserved.
Abreu, Cândida; Silva-Pinto, André; Lazzara, Daniela; Sobrinho-Simões, Joana; Guimarães, João Tiago; Sarmento, António
All the reports from Angola's 2013 dengue outbreak revealed serotype 1. However, previously dengue serotypes 1-4 have been reported in Africa and in 2014 serotype 4 was reported in Angola. To report dengue serotypes in patients returning from Angola during 2013 outbreak. Retrospective, cross-sectional study. We serotyped the dengue by an in house Polymerase Chain Reaction technique in randomly selected cases. From the 2013 Angola's dengue outbreak we treated 47 adult patients. None had history of past dengue. A combo kit test for dengue revealed positive NS1 antigen in 39 and IgM antibodies in 8. From 17 randomly patients tested by RNA Real Time-PCR, 11 were positive: 7 for DENV-1, 2 for DENV-2, 1 for DENV-3 (co-infected with DENV-1) and 1 for DENV-4. None had a complicated or fatal evolution. Unlike previous reports the 4 serotypes were detected, and this resulted in a different epidemiological situation, raising the risk of future outbreaks of severe dengue. Copyright © 2016 Elsevier B.V. All rights reserved.
Drolet, Barbara S.; Reister-Hendricks, Lindsey M.; Podell, Brendan K.; Breitenbach, Jonathan E.; Mcvey, D.S.; Rijn, van Piet A.; Bowen, Richard A.
Bluetongue virus (BTV) is an orbivirus transmitted by biting midges (Culicoides spp.) that can result in moderate to high morbidity and mortality primarily in sheep and white-tailed deer. Although only 5 serotypes of BTV are considered endemic to the United States, as many as 11 incursive
Full Text Available Here; we have described and tested a microarray based-method for the screening of dengue virus (DENV serotypes. This DNA microarray assay is specific and sensitive and can detect dual infections with two dengue virus serotypes and single-serotype infections. Other methodologies may underestimate samples containing more than one serotype. This technology can be used to discriminate between the four DENV serotypes. Single-stranded DNA targets were covalently attached to glass slides and hybridised with specific labelled probes. DENV isolates and dengue samples were used to evaluate microarray performance. Our results demonstrate that the probes hybridized specifically to DENV serotypes; with no detection of unspecific signals. This finding provides evidence that specific probes can effectively identify single and double infections in DENV samples.
Garzetti, Debora; Susen, Rosa; Fruth, Angelika; Tietze, Erhard; Heesemann, Jürgen; Rakin, Alexander
Yersinia enterocolitica is a food-borne, gastro-intestinal pathogen with world-wide distribution. Only 11 serotypes have been isolated from patients, with O:3, O:9, O:8 and O:5,27 being the serotypes most commonly associated with human yersiniosis. Serotype is an important characteristic of Y. enterocolitica strains, allowing differentiation for epidemiology, diagnosis and phylogeny studies. Conventional serotyping, performed by slide agglutination, is a tedious and laborious procedure whose interpretation tends to be subjective, leading to poor reproducibility. Here we present a PCR-based typing scheme for molecular identification and patho-serotyping of Y. enterocolitica. Genome-wide comparison of Y. enterocolitica sequences allowed analysis of the O-antigen gene clusters of different serotypes, uncovering their formerly unknown genomic locations, and selection of targets for serotype-specific amplification. Two multiplex PCRs and one additional PCR were designed and tested on various reference strains and isolates from different origins. Our genotypic assay proved to be highly specific for identification of Y. enterocolitica species, discrimination between virulent and non-virulent strains, distinguishing the main human-related serotypes, and typing of conventionally untypeable strains. This genotyping scheme could be applied in microbiology laboratories as an alternative or complementary method to the traditional phenotypic assays, providing data for epidemiological studies. Copyright © 2013 Elsevier GmbH. All rights reserved.
Kusiluka, L.J.M.; Semuguruka, W.D.; Kazwala, R.R.
by different degrees of vasculitis, and fibrinocellular exudation into the alveolar septae and lumina, and into interlobular septae and pleura. Mycoplasma capricolum subsp. capripneumoniae, Mycoplasma mycoides subsp. mycoides, Small Colony type Mycoplasma ovipneumoniae and Mycoplasma arginini were isolated...... from some of the examined goats including a case with a sequestrum which yielded Mycoplasma mycoides subsp. mycoides, Small Colony type. This work reports the first description of an outbreak of caprine pleuropneumonia in Tanzania in which M. capripneumoniae and M. mycoides subsp. mycoides, Small...
Hadjilouka, Agni; Andritsos, Nikolaos D; Paramithiotis, Spiros; Mataragas, Marios; Drosinos, Eleftherios H
The aim of this study was to assess serotype prevalence and biodiversity of Listeria monocytogenes strains isolated from diverse food products, i.e., minced pork, fruits, and vegetables. Three hundred twenty-six samples previously purchased from supermarkets and street markets within the Athens area were studied for L. monocytogenes prevalence. A total of 121 strains were isolated from the 36 samples that were positive for L. monocytogenes. Serotyping was performed with multiplex PCR, and biodiversity was assessed with random amplified polymorphic DNA (RAPD) PCR analysis using M13, UBC155, and HLWL85 as primers and with repetitive element palindromic (rep) PCR analysis using (GTG)5 as the primer. The majority (17 of 22) of the contaminated minced pork samples contained strains identified as serotype 1/2a, either alone or in combination with strains belonging to serotypes 1/2b, 4a, 4c, or 4ab. However, all L. monocytogenes isolates from fruits and vegetables belonged to serotype 4b. Rep-PCR provided better differentiation of the isolates than did RAPD PCR and resulted in discrimination of the isolates into a larger number of unique profiles. Complete differentiation was achieved only with the combination of these subtyping techniques.
Umer Sadique*, Zafar Iqbal Chaudhry1, Muhammad Younus Rana2, Aftab Ahmad Anjum3, Zahoor-Ul-Hassan, Abdul Sajid and Muhammad Mushtaq
Full Text Available This study was designed to evaluate the pathogenesis of caprine pleuropneumonia (CPP in the experimentally inoculated goats with Mycoplasma mycoides subspecies Capri (Mmc. For this purpose, 12 goats (Group B were inoculated with bacterial isolates of Mmc while four goats were kept as untreated control (Group A. Clinical signs of the disease were recorded twice daily. Two goats from group B were sacrificed on weekly basis to demonstrate gross pathological lesions in different organs. Tissue samples from lungs, trachea, liver, heart, kidney, spleen, and small intestines were preserved for histopathological studies. The lungs and lymph nodes were preserved to demonstrate the antigen in tissue by using immuno- histochemical technique. The disease was successfully reproduced in all infected goats with severe manifestation. The clinical signs and gross lesions of the disease were mild at the beginning and became severe at the third and fourth weeks and then progressed to moderate and chronic forms. The histopathological lesions characteristic of CPP were found in all the organs. Antigen of Mmc was detected in tissue sections of lungs and lymph nodes. In conclusion, the disease was efficiently reproduced in experimental animals that showed acute septicemic form with lethal outcome.
Kiely, R A
This study determined the carriage rate and serotype distribution of group B Streptococcus (GBS) in women of child-bearing age in the southern region of Ireland. A total of 2000 vaginal swabs collected in two periods in 2004 and 2006 were examined and revealed a GBS carriage rate of 16·1%. Serotyping of isolates showed that serotypes Ia, II, III, IV, and V were the most prevalent. A high prevalence of serotype IV was found, increasing from 7·6% to 15·2% between 2004 and 2006. Random amplified polymorphic DNA analysis demonstrated considerable genetic heterogeneity in the serotype IV isolates. This serotype should be considered for inclusion in potential vaccines for use in Ireland.
Botulinum neurotoxins (BoNTs) are among the most toxic biological toxins for humans. Of the seven known serotypes (A-G) of BoNT, serotypes A, B and E cause most of the human foodborne intoxications. In this study, we compared the toxicological properties of BoNT serotype A and B holotoxins and compl...
Full Text Available Abstract Background Feed-borne spread of Salmonella spp. to pigs has been documented several times in recent years in Sweden. Experiences from the field suggest that feed-associated serotypes might be less transmittable and subsequently easier to eradicate from pig herds than other serotypes more commonly associated to pigs. Four Salmonella serotypes were selected for experimental studies in pigs in order to study transmissibility and compare possible differences between feed-assoociated (S Cubana and S Yoruba and pig-associated serotypes (S Derby and S Typhimurium. Methods Direct contact transmission was studied in four groups of pigs formed by six 10-week-old salmonella negative pigs commingled with two fatteners excreting one of the four salmonella serotypes. Indirect transmission was studied by putting six 10-week-old salmonella negative pigs in each of four salmonella contaminated rooms. Each room had previously housed a group of pigs, excreting one of the four selected serotypes. All pigs were monitored for two weeks with respect to the faecal excretion of salmonella and the presence of serum antibodies. At the end of the trial, eight samples from inner tissues and organs were collected from each pig at necropsy. Results In the four direct transmission groups, one pig shed Salmonella (Cubana at one occasion. At necropsy, S Typhimurium was isolated from one pig. In the indirect transmission groups, two pigs in the Yoruba room and one pig in each of the other rooms were excreting detectable levels of Salmonella once during the study period of two weeks. At necropsy, S Derby was isolated from one of six pigs in the Derby room and S Typhimurium was isolated from four of the six pigs in the Typhimurium room. No significant serological response could be detected in any of the 48 pigs. Conclusions These results show that all four selected serotypes were able to be transmitted in at least one of these field-like trials, but the transmission rate
Trzciński, Krzysztof; Li, Yuan; Weinberger, Daniel M; Thompson, Claudette M; Cordy, Derrick; Bessolo, Andrew; Malley, Richard; Lipsitch, Marc
Competitive interactions between Streptococcus pneumoniae strains during host colonization could influence the serotype distribution in nasopharyngeal carriage and pneumococcal disease. We evaluated the competitive fitness of strains of serotypes 6B, 14, 19A, 19F, 23F, and 35B in a mouse model of multiserotype carriage. Isogenic variants were constructed using clinical strains as the capsule gene donors. Animals were intranasally inoculated with a mixture of up to six pneumococcal strains of different serotypes, with separate experiments involving either clinical isolates or isogenic capsule-switch variants of clinical strain TIGR4. Upper-respiratory-tract samples were repeatedly collected from animals in order to monitor changes in the serotype ratios using quantitative PCR. A reproducible hierarchy of capsular types developed in the airways of mice inoculated with multiple strains. Serotype ranks in this hierarchy were similar among pneumococcal strains of different genetic backgrounds in different strains of mice and were not altered when tested under a range of host conditions. This rank correlated with the measure of the metabolic cost of capsule synthesis and in vitro measure of pneumococcal cell surface charge, both parameters considered to be predictors of serotype-specific fitness in carriage. This study demonstrates the presence of a robust competitive hierarchy of pneumococcal serotypes in vivo that is driven mainly, but not exclusively, by the capsule itself. Streptococcus pneumoniae (pneumococcus) is the leading cause of death due to respiratory bacterial infections but also a commensal frequently carried in upper airways. Available vaccines induce immune responses against polysaccharides coating pneumococcal cells, but with over 90 different capsular types (serotypes) identified, they can only target strains of the selected few serotypes most prevalent in disease. Vaccines not only protect vaccinated individuals against disease but also protect by
Cheaib, Miriam; Dehghani Amirabad, Azim; Nordström, Karl J V; Schulz, Marcel H; Simon, Martin
Phenotypic variation of a single genotype is achieved by alterations in gene expression patterns. Regulation of such alterations depends on their time scale, where short-time adaptations differ from permanently established gene expression patterns maintained by epigenetic mechanisms. In the ciliate Paramecium, serotypes were described for an epigenetically controlled gene expression pattern of an individual multigene family. Paradoxically, individual serotypes can be triggered in Paramecium by alternating environments but are then stabilized by epigenetic mechanisms, thus raising the question to which extend their expression follows environmental stimuli. To characterize environmental adaptation in the context of epigenetically controlled serotype expression, we used RNA-seq to characterize transcriptomes of serotype pure cultures. The resulting vegetative transcriptome resource is first analysed for genes involved in the adaptive response to the altered environment. Secondly, we identified groups of genes that do not follow the adaptive response but show co-regulation with the epigenetically controlled serotype system, suggesting that their gene expression pattern becomes manifested by similar mechanisms. In our experimental set-up, serotype expression and the entire group of co-regulated genes were stable among environmental changes and only heat-shock genes altered expression of these gene groups. The data suggest that the maintenance of these gene expression patterns in a lineage represents epigenetically controlled robustness counteracting short-time adaptation processes. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.
Benschop, Kimberley S. M.; Schinkel, Janke; Luken, Manon E.; van den Broek, Peter J. M.; Beersma, Matthias F. C.; Menelik, Negassi; van Eijk, Hetty W. M.; Zaaijer, Hans L.; Vandenbroucke-Grauls, Christina M. J. E.; Beld, Marcel G. H. M.; Wolthers, Katja C.
We identified a novel human parechovirus (HPeV) type (K251176-02) from a neonate with fever. Analysis of the complete genome showed K251176-02 to be a new HPeV genotype. Since K251176-02 could not be neutralized with antibodies against known HPeV serotypes 1-3, it should be classified as a fourth
Chen, Hao-tai; Peng, Yun-hua; Zhang, Yong-guang; Liu, Xiang-tao
An ELISA assay with monoclonal antibody (MELISA) was used to type serotype O of foot-and-mouth disease virus (FMDV). All FMDV serotype O reference strains were positive by MELISA, while other viruses such as FMDV serotypes Asia 1, C, and A and classical swine fever virus, swine vesicular disease virus, and porcine reproductive and respiratory syndrome virus remained negative. Furthermore, FMDV serotype O positive samples were able to be detected by MELISA. This assay may be particularly suita...
Olsen, Helle G; Skovgaard, Kerstin; Nielsen, Ole L
Serum amyloid A (SAA) is a prominent acute phase protein. Although its biological functions are debated, the wide species distribution of highly homologous SAA proteins and their uniform behavior in response to injury or inflammation in itself suggests a significant role for this protein. The pig...... is increasingly being used as a model for the study of inflammatory reactions, yet only little is known about how specific SAA genes are regulated in the pig during acute phase responses and other responses induced by pro-inflammatory host mediators. We designed SAA gene specific primers and quantified the gene...... expression of porcine SAA1, SAA2, SAA3, and SAA4 by reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) in liver, spleen, and lung tissue from pigs experimentally infected with the Gram-negative swine specific bacterium Actinobacillus pleuropneumoniae, as well as from pigs experimentally...
Dewhirst, F E; Paster, B J; Olsen, I; Fraser, G J
Virtually complete 16S rRNA sequences were determined for 54 representative strains of species in the family Pasteurellaceae. Of these strains, 15 were Pasteurella, 16 were Actinobacillus, and 23 were Haemophilus. A phylogenetic tree was constructed based on sequence similarity, using the Neighbor-Joining method. Fifty-three of the strains fell within four large clusters. The first cluster included the type strains of Haemophilus influenzae, H. aegyptius, H. aphrophilus, H. haemolyticus, H. paraphrophilus, H. segnis, and Actinobacillus actinomycetemcomitans. This cluster also contained A. actinomycetemcomitans FDC Y4, ATCC 29522, ATCC 29523, and ATCC 29524 and H. aphrophilus NCTC 7901. The second cluster included the type strains of A. seminis and Pasteurella aerogenes and H. somnus OVCG 43826. The third cluster was composed of the type strains of Pasteurella multocida, P. anatis, P. avium, P. canis, P. dagmatis, P. gallinarum, P. langaa, P. stomatis, P. volantium, H. haemoglobinophilus, H. parasuis, H. paracuniculus, H. paragallinarum, and A. capsulatus. This cluster also contained Pasteurella species A CCUG 18782, Pasteurella species B CCUG 19974, Haemophilus taxon C CAPM 5111, H. parasuis type 5 Nagasaki, P. volantium (H. parainfluenzae) NCTC 4101, and P. trehalosi NCTC 10624. The fourth cluster included the type strains of Actinobacillus lignieresii, A. equuli, A. pleuropneumoniae, A. suis, A. ureae, H. parahaemolyticus, H. parainfluenzae, H. paraphrohaemolyticus, H. ducreyi, and P. haemolytica. This cluster also contained Actinobacillus species strain CCUG 19799 (Bisgaard taxon 11), A. suis ATCC 15557, H. ducreyi ATCC 27722 and HD 35000, Haemophilus minor group strain 202, and H. parainfluenzae ATCC 29242. The type strain of P. pneumotropica branched alone to form a fifth group. The branching of the Pasteurellaceae family tree was quite complex. The four major clusters contained multiple subclusters. The clusters contained both rapidly and slowly evolving
Karen A. Borges
Full Text Available ABSTRACT: Salmonella spp. are one of the most important agents of foodborne disease in several countries, including Brazil. Poultry-derived products are the most common food products, including meat and eggs, involved in outbreaks of human salmonellosis. Salmonella has the capacity to form biofilms on both biotic and abiotic surfaces. The biofilm formation process depends on an interaction among bacterial cells, the attachment surface and environmental conditions. These structures favor bacterial survival in hostile environments, such as slaughterhouses and food processing plants. Biofilms are also a major problem for public health because breakage of these structures can cause the release of pathogenic microorganisms and, consequently, product contamination. The aim of this study was to determine the biofilm production capacity of Salmonella serotypes at four different temperatures of incubation. Salmonella strains belonging to 11 different serotypes, isolated from poultry or from food involved in salmonellosis outbreaks, were selected for this study. Biofilm formation was investigated under different temperature conditions (37°, 28°, 12° and 3°C using a microtiter plate assay. The tested temperatures are important for the Salmonella life cycle and to the poultry-products process. A total of 92.2% of the analyzed strains were able to produce biofilm on at least one of the tested temperatures. In the testing, 71.6% of the strains produced biofilm at 37°C, 63% at 28°C, 52.3% at 12°C and 39.5% at 3°C, regardless of the serotype. The results indicate that there is a strong influence of temperature on biofilm production, especially for some serotypes, such as S. Enteritidis, S. Hadar and S. Heidelberg. The production of these structures is partially associated with serotype. There were also significant differences within strains of the same serotype, indicating that biofilm production capacity may be strain-dependent.
van der Reijden, Wil A.; Brunner, Jorg; Bosch-Tijhof, Carolien J.; van Trappen, Stefanie; Rijnsburger, Martine C.; de Graaff, Marcel P. W.; van Winkelhoff, Arie J.; Cleenwerck, Ilse; de Vos, Paul
The periodontal pathogen Aggregatibacter actinomycetemcomitans that comprises six serotypes (a-f), is often identified by PCR-based techniques targeting the 16S rRNA gene. In this study, 16S rRNA gene sequence analysis revealed an aberrant cluster of 19 strains within serotype e, denoted as serotype
Gaensbauer, James T; Asturias, Edwin J; Soto, Monica; Holt, Elizabeth; Olson, Daniel; Halsey, Neal A
To inform estimations of the potential impact of recently introduced pneumococcal conjugate vaccine (PCV), we report results of 11 years of pre-PCV surveillance for invasive pneumococcal disease (IPD) among children in Guatemala City. Cases of IPD in children younger than 5 years were identified by active surveillance at 3 referral hospitals in Guatemala City from October 1996 through 2007. Clinical and demographic data were obtained, and isolates of Streptococcus pneumoniae from normally sterile sites were serotyped using latex agglutination and confirmed by Quellung reaction. Four hundred fifty-two cases of IPD were identified with a case fatality rate of 21%. Meningitis was the most common cause of death (77% of all deaths) and occurred more often in infancy (median age 5 months) than other clinical syndromes. Of the 137 isolates serotyped, type 1 (26 cases, 17%), type 2 (25 cases, 16%) and type 5 (18 cases, 12%) were the most common. Serotype 2 was associated with a higher case fatality rate (28%), higher rate of meningitis (68%) and occurred in younger infants (median age, 3.5 months) than other common serotypes. Recently introduced PCV13 includes 73% of observed serotypes in the study. Infants with IPD presented at a young age. Serotype 2, rarely reported as a significant cause of IPD and not included in available PCVs, was a common cause of disease in this population. PCV13 introduction in Guatemala, begun in 2013, may not have as great an impact in disease reduction as has been observed in other countries.
Drolet, B.S.; Reister, L.M.; Mecham, J.O.; Wilson, W.C.; Nol, P.; Vercauteren, K.C.; Rijn, van P.A.; Bowen, R.A.
Bluetongue (BT) is an insect-transmitted, economically important disease of domestic and wild ruminants. Although only five of the 26 reported bluetongue virus (BTV) serotypes are considered endemic to the USA, 10 exotic serotypes have been isolated primarily in the southeastern region of the
Cho, Ying-Chun; Chiu, Nan-Chang; Lu, Chun-Yi; Huang, Daniel Tsung-Ning; Huang, Fu-Yuan; Chang, Luan-Yin; Huang, Li-Min; Chi, Hsin
After the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) against Streptococcus pneumoniae, public health officials in Taiwan monitored a decline in circulating vaccine serotypes and the emergence of nonvaccine serotypes in children with invasive pneumococcal disease. A gradually expanded PCV13 national immunization program was launched in 2013 in Taiwan. Here, we evaluate the changes in the distribution of pneumococcal serotypes and antimicrobial nonsusceptibility in children during the evolution of vaccination policy. S. pneumoniae isolates from children with pneumococcal disease were collected and serotyped from 2010 to 2015 in northern Taiwan. PCVs were administered at the recipients' expense between 2010 and 2012, and then PCV13 was partially reimbursed by the government beginning in 2013. The distribution and diversity of serotypes were analyzed along with their antimicrobial susceptibilities. Among a total of 498 isolates, the proportion of invasive pneumococcal disease isolates declined (47.1%-10.6%) during the study period, and serotype diversity increased after 2011. Between 2010 and 2012, the dominant serotypes were 19A, 19F, 3, 6B and 14, and serotype 19A rose from 44.1% to 57.5%. Serotypes 19A, 15A, 19F and 15B were more prevalent from 2013 to 2015, and serotype 19A decreased from 42.1% to 4.5%. Serotypes 19F and 15A became the most commonly detected serotypes in 2015. Overall, PCV13 additional serotypes were reduced by 80% (P program is effective against pneumococcal disease in Taiwanese children, mainly by reducing PCV13 additional serotypes.
Chen, Kequan; Jiang, Min; Wei, Ping; Yao, Jiaming; Wu, Hao
Dilute acid hydrolysate of corn fiber was used as carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. The optimized hydrolysis conditions were obtained by orthogonal experiments. When corn fiber particles were of 20 mesh in size and treated with 1.0% sulfuric acid at 121 degrees C for 2 h, the total sugar yield could reach 63.3%. It was found that CaCO(3) neutralization combined with activated carbon adsorption was an effective method to remove fermentation inhibitors especially furfural that presented in the acid hydrolysate of corn fiber. Only 5.2% of the total sugar was lost, while 91.9% of furfural was removed. The yield of succinic acid was higher than 72.0% with the detoxified corn fiber hydrolysate as the carbon source in anaerobic bottles or 7.5 L fermentor cultures. It was proved that the corn fiber hydrolysate could be an alternative to glucose for the production of succinic acid by A. succinogenes NJ113.
Doijad, Swapnil P.; Barbuddhe, Sukhadeo B.; Garg, Sandeep; Poharkar, Krupali V.; Kalorey, Dewanand R.; Kurkure, Nitin V.; Rawool, Deepak B.; Chakraborty, Trinad
A total of 98 previously characterized and serotyped L. monocytogenes strains, comprising 32 of 1/2a; 20 of 1/2b and 46 of 4b serotype, from clinical and food sources were studied for their capability to form a biofilm. The microtiter plate assay revealed 62 (63.26%) strains as weak, 27 (27.55%) strains as moderate, and 9 (9.18%) strains as strong biofilm formers. Among the strong biofilm formers, 6 strains were of serotype 1/2a and 3 strains were of serotype 1/2b. None of the strain from 4b serotype exhibited strong biofilm formation. No firm correlation (p = 0.015) was noticed between any serotype and respective biofilm formation ability. Electron microscopic studies showed that strong biofilm forming isolates could synthesize a biofilm within 24 h on surfaces important in food industries such as stainless steel, ceramic tiles, high-density polyethylene plastics, polyvinyl chloride pipes, and glass. Cell enumeration of strong, moderate, and weak biofilm was performed to determine if the number of cells correlated with the biofilm-forming capabilities of the isolates. Strong, moderate, and weak biofilm showed 570±127× 103 cells/cm2, 33±26× 103 cells/cm2, 5±3× 103 cells/cm2, respectively, indicating that the number of cells was directly proportional to the strength of the biofilm. The hydrophobicity index (HI) analysis revealed higher hydrophobicity with an increased biofilm formation. Fatty acid methyl esterase analysis revealed the amount of certain fatty acids such as iso-C15:0, anteiso-C15:0, and anteiso-C17:0 fatty acids correlated with the biofilm-forming capability of L. monocytogenes. This study showed that different strains of L. monocytogenes form biofilm of different intensities which did not completely correlate with their serotype; however, it correlated with the number of cells, hydrophobicity, and amount of certain fatty acids. PMID:26360831
Swapnil P Doijad
Full Text Available A total of 98 previously characterized and serotyped L. monocytogenes strains, comprising 32 of 1/2a; 20 of 1/2b and 46 of 4b serotype, from clinical and food sources were studied for their capability to form a biofilm. The microtiter plate assay revealed 62 (63.26% strains as weak, 27 (27.55% strains as moderate, and 9 (9.18% strains as strong biofilm formers. Among the strong biofilm formers, 6 strains were of serotype 1/2a and 3 strains were of serotype 1/2b. None of the strain from 4b serotype exhibited strong biofilm formation. No firm correlation (p = 0.015 was noticed between any serotype and respective biofilm formation ability. Electron microscopic studies showed that strong biofilm forming isolates could synthesize a biofilm within 24 h on surfaces important in food industries such as stainless steel, ceramic tiles, high-density polyethylene plastics, polyvinyl chloride pipes, and glass. Cell enumeration of strong, moderate, and weak biofilm was performed to determine if the number of cells correlated with the biofilm-forming capabilities of the isolates. Strong, moderate, and weak biofilm showed 570±127× 103 cells/cm2, 33±26× 103 cells/cm2, 5±3× 103 cells/cm2, respectively, indicating that the number of cells was directly proportional to the strength of the biofilm. The hydrophobicity index (HI analysis revealed higher hydrophobicity with an increased biofilm formation. Fatty acid methyl esterase analysis revealed the amount of certain fatty acids such as iso-C15:0, anteiso-C15:0, and anteiso-C17:0 fatty acids correlated with the biofilm-forming capability of L. monocytogenes. This study showed that different strains of L. monocytogenes form biofilm of different intensities which did not completely correlate with their serotype; however, it correlated with the number of cells, hydrophobicity, and amount of certain fatty acids.
Full Text Available Background: Actinobacillus actinomycetemcomitans is thought to be one of the etiological agents in aggressive periodontitis as well as indicated in various systemic diseases. Objective: To evaluate the prevalence of A. actinomycetemcomitans in the subgingival plaque of aggressive periodontitis patients. Study Design: Initially, under the selective growth conditions, the isolates were picked from the plaques and their identification was confirmed by polymerase chain reaction using primers specific for A. actinomycetemcomitans subgingival plaque of 15 patients diagnosed clinically and on radiographic criteria as aggressive periodontitis was inoculated on the Tryptic Soy agar with Bacitracin and Vancomycin culture media for 3-5 days under microaerophilic conditions. The positive colonies were selected based on biochemical tests for further analysis using reported primers for A. actinomycetemcomitans. Results: The results showed that 66.67% of aggressive periodontitis patients and 6.67% of control group of normal patients showed evidence of presence of A. actinomycetemcomitans in the subgingival microflora. Conclusion: This is the first study of its kind in an Indian population whereby almost all aggressive periodontitis patients showed evidence of A. actinomycetemcomitans.
Rochat, Tatiana; Fujiwara-Nagata, Erina; Calvez, Ségolène
Flavobacterium psychrophilum is a devastating bacterial pathogen of salmonids reared in freshwater worldwide. So far, serological diversity between isolates has been described but the underlying molecular factors remain unknown. By combining complete genome sequence analysis and the serotyping me...... for bacterial coldwater disease resistance and future vaccine formulation....
Takano, Tomomi; Nakano, Kenta; Doki, Tomoyoshi; Hohdatsu, Tsutomu
Feline infectious peritonitis virus (FIP virus: FIPV), a feline coronavirus of the family Coronaviridae, causes a fatal disease called FIP in wild and domestic cat species. The genome of coronaviruses encodes a hydrophobic transmembrane protein, the envelope (E) protein. The E protein possesses ion channel activity. Viral proteins with ion channel activity are collectively termed "viroporins". Hexamethylene amiloride (HMA), a viroporin inhibitor, can inhibit the ion channel activity of the E protein and replication of several coronaviruses. However, it is not clear whether HMA and other viroporin inhibitors affect replication of FIPV. We examined the effect of HMA and other viroporin inhibitors (DIDS [4,4'-disothiocyano-2,2'-stilbenedisulphonic acid] and amantadine) on infection by FIPV serotypes I and II. HMA treatment drastically decreased the titers of FIPV serotype I strains Black and KU-2 in a dose-dependent manner, but it only slightly decreased the titer of FIPV serotype II strain 79-1146. In contrast, DIDS treatment decreased the titer of FIPV serotype II strain 79-1146 in dose-dependent manner, but it only slightly decreased the titers of FIPV serotype I strains Black and KU-2. We investigated whether there is a difference in ion channel activity of the E protein between viral serotypes using E. coli cells expressing the E protein of FIPV serotypes I and II. No difference was observed, suggesting that a viroporin other than the E protein influences the differences in the actions of HMA and DIDS on FIPV serotypes I and II.
Slotved, Hans-Christian; Dayie, Nicholas T K D; Banini, Josephine A N
was performed on a single subcultured colony. Gram staining was performed, and isolates were evaluated for beta-haemolytic reactions. Furthermore, the isolates were serotyped using the GBS latex serotyping kit. RESULTS: The carriage rates were found to be 25.5% (95% CI: 19.6-32.1) to 28.0% (95% CI: 21...... of this study revealed that prevalence of GBS colonization in pregnant women in Greater Accra region is high and comparable to rates observed in South Africa and Western countries. The most prevalent serotypes were serotypes VII and IX, which have not been observed before in West Africa....
We need to raise the issue that focus on children as the only carriage group for pneumococci is not optimal; we need to consider that other age groups might also be carriers of pneumococcal serotypes causing invasive pneumococcal diseases (IPD) in unvaccinated age groups. The pneumococcal conjugate vaccines (PCV) have successfully removed IPD from vaccinated children. Studies have shown an effect of PCV reducing the pneumococcal carriage of PCV serotypes in children. The status for several countries having used PCV for many years is that they do not see PCV serotypes neither carried nor as a cause of IPD in children. PCV vaccination of children has shown a herd protection effect in unvaccinated groups as a reduction in IPD cases caused by PCV serotypes. However, not all PCV serotypes have disappeared as the cause of IPD in the unvaccinated age groups. The author therefore believes that if we are to see PCV serotypes disappear as a cause of IPD in unvaccinated age groups, we need to perform further carriage studies to examine carriage in other age groups. Alternatively, all age groups should be vaccinated against pneumococci to eliminate IPD caused by PCV serotypes from possible hidden carriers.
Martens, Pernille; Worm, Signe Westring; Lundgren, Bettina
Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited.Martens P, Worm SW, Lundgren B, Konradsen HB, Benfield T. Department of Infectious Diseases 144, Hvidovre University Hospital, DK-2650 Hvidovre, Denmark. email@example.com BACKGROUND: Invasive infection...... with Streptococcus pneumoniae (pneumococci) causes significant morbidity and mortality. Case series and experimental data have shown that the capsular serotype is involved in the pathogenesis and a determinant of disease outcome. METHODS: Retrospective review of 464 cases of invasive disease among adults diagnosed...
Laine, ML; van Winkelhoff, AJ
Capsular structures of Porphyromonas gingivalis have been correlated to the pathogenicity in animal models. Six polysaccharide capsular serotypes have recently been described in P. gingivalis. In the present study, virulence of the P. gingivalis strains of the six capsular serotypes was compared
Full Text Available Infections of Streptococcus pneumoniae in children can be prevented by vaccination; left untreated, they cause high morbidity and fatalities. This study aimed at determining the nasopharyngeal carrier rates, serotype distribution and antimicrobial resistance patterns of S. pneumoniae in healthy Palestinian children under age two prior to the full introduction of the pneumococcal 7-valent conjugate vaccine (PCV7, which was originally introduced into Palestine in a pilot trial in September, 2010. In a cross sectional study, nasopharyngeal specimens were collected from 397 healthy children from different Palestinian districts between the beginning of November 2012 to the end of January 2013. Samples were inoculated into blood agar and suspected colonies were examined by amplifying the pneumococcal-specific autolysin gene using a real-time PCR. Serotypes were identified by a PCR that incorporated different sets of specific primers. Antimicrobial susceptibility was measured by disk diffusion and MIC methods. The resulting carrier rate of Streptococcus pneumoniae was 55.7% (221/397. The main serotypes were PCV7 serotypes 19F (12.2%, 23F (9.0%, 6B (8.6% and 14 (4% and PCV13 serotypes 6A (13.6% and 19A (4.1%. Notably, serotype 6A, not included in the pilot trial (PCV7 vaccine, was the most prevalent. Resistance to more than two drugs was observed for bacteria from 34.1% of the children (72/211 while 22.3% (47/211 carried bacteria were susceptible to all tested antibiotics. All the isolates were sensitive to cefotaxime and vancomycin. Any or all of these might impinge on the type and efficacy of the pneumococcal conjugate vaccines and antibiotics to be used for prevention and treatment of pneumococcal disease in the country.
Full Text Available While pneumococcal conjugate vaccines have been implemented in most countries worldwide, use in Asia has lagged in part because of a lack of data on the amount of disease that is vaccine preventable in the region. We describe pneumococcal serotypes elicited from 111 episodes of invasive pneumococcal disease (IPD from 2005 to 2013 among children and adults in Pakistan. Seventy-three percent (n = 81 of 111 IPD episodes were cases of meningitis (n = 76 in children 0-15 years and n = 5 among adults. Serotypes were determined by target amplification of DNA extracted from pneumococcal isolates (n = 52 or CSF specimens (n = 59. Serogroup 18 was the most common serogroup causing meningitis in children <5 years, accounting for 21% of cases (n = 13. The 10-valent pneumococcal conjugate vaccine (PCV 10 or PCV10- related serotypes were found in 61% (n = 47 of childhood (age 0-15 years meningitis episodes. PCV-13 increased this coverage to 63% (one additional serotype 19A; n = 48. Our data indicate that use of PCVs would prevent a large proportion of serious pneumococcal disease.
Full Text Available ABSTRACT The aim of this work was to study the prevalence of Listeria monocytogenes in foods obtained in retail shops and food industries located in Montevideo-Uruguay, and to identify the serogroups of the obtained isolates. Three-thousand one-hundred and seventy-five food samples (frozen, deli meats, ready-to-eat and cheese were analyzed. The obtained isolates were serogrouped by multiplex PCR and serotyped by conventional procedure. Genetic comparisons were performed using pulsed-field gel electrophoresis on a sub-set of isolates belonging to the same serotype successively recovered from the same establishment. L. monocytogenes was isolated from 11.2% of samples. The highest prevalence was observed in frozen foods (38%, followed by cheese (10%. 1/2b and 4b were the most frequently identified serotypes. In six of 236 analyzed establishments we successively recovered L. monocytogenes isolates belonging to the same serotype. Most of them corresponded to serotype 1/2b. Pulsed-field gel electrophoresis profiles suggest that at least 33% of L. monocytogenes 1/2b isolates are genetically related and that may remain viable for prolonged periods. The observed prevalence of L. monocytogenes was lower than reported in neighboring countries. Our findings highlight the role that frozen foods may play in the spread of this pathogen, and the relevance of serotypes 1/2b and 4b.
Full Text Available Shigella flexneri is the major pathogen causing bacillary dysentery in developing countries. S. flexneri is divided into at least 16 serotypes based on the combination of antigenic determinants present in the O-antigen. All the serotypes (except for serotype 6 share a basic O-unit containing one N-acetyl-d-glucosamine and three l-rhamnose residues, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation. Serotype Xv is a newly emerged and the most prevalent serotype in China, which can agglutinate with both MASF IV-1 and 7,8 monoclonal antibodies. The factor responsible for the presence of MASF IV-1 (E1037 epitope has not yet been identified. In this study, we analyzed the LPS structure of serotype Xv strains and found that the MASF IV-1 positive phenotype depends on an O-antigen modification with a phosphoethanolamine (PEtN group attached at position 3 of one of the rhamnose residues. A plasmid carried gene, lpt-O (LPS phosphoethanolamine transferase for O-antigen, mediates the addition of PEtN for serotype Xv and other MASF IV-1 positive strains. These findings reveal a novel serotype conversion mechanism in S. flexneri and show the necessity of further extension of the serotype classification scheme recognizing the MASF IV-1 positive strains as distinctive subtypes.
VARIATIONS IN VIRULENCE OF THREE (3) ESCHERICHIA COLI. SEROTYPES CONFIRMED IN ... ows are susceptible to E. coli infection because. E. coli exist in the .... Coli infections in mice: A laboratory animal model for research in.
ten Have, R; Westdijk, J; Levels, L M A R; Koedam, P; de Haan, A; Hamzink, M R J; Metz, B; Kersten, G F A
This study addresses observations made in view of testing in practice the guideline in the European Pharmacopoeia (EP) on omitting the rat potency test for release of polio containing vaccines. In general, use of the guideline is valid and the D-antigen ELISA can indeed be used as an in vitro alternative for the in vivo test. However, the set-up of the ELISA is crucial and should include detection of antigenic site 1 in polio serotype 3 as destruction of that site by trypsin results in a reduced rat potency. Antigenic site 1 in polio serotype 2 may also be modified by trypsin, but the cleavage of viral protein 1 (VP1) did not affect the rat potency. Therefore, any antigenic site, except site 1, can be used for detection of polio serotype 2. It is advised to include testing of the effect of trypsin treatment in the EP-guideline. This allows polio vaccine manufacturers to check whether their in-house ELISA needs improvement. Copyright © 2015 The International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.
Full Text Available Vibrio parahaemolyticus has emerged as a major foodborne pathogen in China, Japan, Thailand and other Asian countries. In this study, 72 strains of V. parahaemolyticus were isolated from clinical and environmental samples between 2006 and 2014 in Jiangsu, China. The serotypes and six virulence genes including thermostable direct hemolysin (TDR and TDR-related hemolysin (TRH genes were assessed among the isolates. Twenty five serotypes were identified and O3:K6 was one of the dominant serotypes. The genetic diversity was assessed by multilocus sequence typing (MLST analysis, and 48 sequence types (STs were found, suggesting this V. parahaemolyticus group is widely dispersed and undergoing rapid evolution. A total of 25 strains of pandemic serotypes such as O3:K6, O5:K17 and O1:KUT were identified. It is worth noting that the pandemic serotypes were not exclusively identified from clinical samples, rather, nine strains were also isolated from environmental samples; and some of these strains harbored several virulence genes, which may render those strains pathogenicity potential. Therefore, the emergence of these environmental pandemic V. parahaemolyticus strains may poses a new threat to the public health in China. Furthermore, six novel serotypes and 34 novel STs were identified among the 72 isolates, indicating that V. parahaemolyticus were widely distributed and fast evolving in the environment in Jiangsu, China. The findings of this study provide new insight into the phylogenic relationship between V. parahaemolyticus strains of pandemic serotypes from clinical and environmental sources and enhance the MLST database; and our proposed possible O- and K- antigen evolving paths of V. parahaemolyticus may help understand how the serotypes of this dispersed bacterial population evolve.
van der Reijden, Wil A.; Bosch-Tijhof, Carolien J.; van der Velden, Ubele; van Winkelhoff, Arie Jan
Objective: To investigate the serotype distribution and stability of Aggregatibacter actinomycetemcomitans over an 8-year period in untreated Indonesian subjects. Material and Methods: Clinical periodontal status and the presence of A. actinomycetemcomitans were established in 1994 and 2002 in 107
Dayie, Nicholas T. K. D.; Arhin, Reuben E.; Newman, Mercy J.
Background: The objective of this study was to determine the prevalence of nasopharyngeal carriage, serotype distribution, and penicillin resistance of Streptococcus pneumoniae in children 2 mu g/ml and were classified as fully penicillin resistant with 45% of the isolates having intermediate...... serotypes detected. The two penicillin resistant isolates (MIC 32 mu g/ml) were serotypes included in both PCV-13 and PPV-23. A nationwide monitoring system of penicillin susceptibility patterns and pneumococcal serotypes is recommended....
Oludele, John; Lesko, Birgitta; Mahumane Gundane, Isabel; de Bruycker-Nogueira, Fernanda; Muianga, Argentina; Ali, Sadia; Mula, Flora; Chelene, Imelda; Falk, Kerstin I; Barreto Dos Santos, Flávia; Gudo, Eduardo Samo
After the report of an outbreak of dengue virus serotype 2 in 2014 in Nampula and Pemba cities, northern Mozambique, a surveillance system was established by the National Institute of Health. A study was performed during 2015-2016 to monitor the trend of the outbreak and confirm the circulating serotype of dengue virus (DENV). After the inclusion of consenting patients who met the case definition, samples from 192 patients were tested for the presence of nonstructural protein 1 antigen, and 60/192 (31%) samples were positive. Further analysis included DENV IgM antibodies, with 39 (20%) IgM positive cases. Reverse transcriptase (RT) PCR was performed for identification of the prevailing DENV serotype; 21/23 tested samples were DENV-2 positive, with DENV-2 present in both affected cities. When sequencing DENV, phenotype Cosmopolitan was identified. The surveillance indicates ongoing spread of DENV-2 in northern Mozambique 2 years after the first report of the outbreak.
Nielsen, Eva Møller; Nielsen, Niels Ladefoged
to study the serotype distribution of C. jejuni and C. coli isolated from different food products of poultry origin sampled from retail outlets in Denmark. A total of 156 isolates were serotyped, 85% of these were C. jejuni and 15% were C. coli. The most common C. jejuni serotypes were O:2 (30%), O:1...... nontypable. This rate of nontypable isolates is significantly higher than experienced for isolates from other sources than food products, i.e faecal samples from animals and humans. Subculturing and re-typing of the nontypable isolates improved the typability. After two, five and 10 subcultures 16, six...
Ullah, A; Jamal, S M; Romey, A; Gorna, K; Kakar, M A; Abbas, F; Ahmad, J; Zientara, S; Bakkali Kassimi, L
This study reports characterization of foot-and-mouth disease virus (FMDV) in samples collected from Balochistan, Pakistan. FMDV was detected by pan-FMDV real-time RT-PCR in 31 samples (epithelial and oral swabs) collected in 2011 from clinical suspect cases. Of these, 29 samples were serotyped by serotype-specific real-time RT-PCR assays and were confirmed by sequencing the VP1 coding region. Sixteen samples were found positive for serotype A and eight for serotype Asia-1, whereas five samples were found positive for both serotypes A and Asia-1. Two serotype A positive samples were found positive for two different strains of serotype A FMDV each. Phylogenetic analyses of serotype A FMDVs showed circulation of at least three different sublineages within the A-Iran05 lineage. These included two earlier reported sublineages, A-Iran05 HER -10 and A-Iran05 FAR -11 , and a new sublineage, designated here as A-Iran05 BAL -11 . This shows that viruses belonging to the A-Iran05 lineage are continuously evolving in the region. Viruses belonging to the A-Iran05 FAR -11 sublineage showed close identity with the viruses circulating in 2009 in Pakistan and Afghanistan. However, viruses belonging to the A-Iran05 HER -10 detected in Balochistan, Pakistan, showed close identity with the viruses circulating in Kyrgyzstan, Iran and Kazakhstan in 2011 and 2012, showing that viruses responsible for outbreak in these countries have a common origin. Serotype Asia-1 FMDVs reported in this study all belonged to the earlier reported Group-VII (Sindh-08), which is currently a dominant strain in the West Eurasian region. Detection of two different serotypes of FMDV or/and two different strains of the same serotype in one animal/sample shows complexity in occurrence of FMD in the region. © 2016 Blackwell Verlag GmbH.
Hatrongjit, Rujirat; Kerdsin, Anusak; Gottschalk, Marcelo; Takeuchi, Dan; Hamada, Shigeyuki; Oishi, Kazunori; Akeda, Yukihiro
Streptococcus suis is a zoonotic pathogen that causes invasive infections in humans and pigs. It has been reported that S. suis infection in humans is mostly caused by serotype 2. However, human cases caused by other serotypes have rarely been reported. This is the first report of a human case of infection with S. suis serotype 31 in Thailand. A 55-year-old male alcohol misuser with liver cirrhosis was admitted with sepsis to a hospital in the Central Region of Thailand. He had consumed a homemade, raw pork product prior to the onset of illness. He was alive after treatment with ceftriaxone and no complication occurred. An isolate from blood culture at the hospital was suspected as viridans group Streptococcus. It was confirmed at a reference laboratory as S. suis serotype 31 by biochemical tests, 16S rDNA sequencing, and multiplex polymerase chain reaction for serotyping, but it was untypable by the co-agglutination test with antisera against recognized S. suis serotypes, suggesting loss of capsular material. The absence of a capsule was confirmed by transmission electron microscopy. The isolate was confirmed to be sequence type 221, with 13 putative virulence genes that are usually found in serotype 2 strains. We should be aware of the emergence of S. suis infections caused by uncommon serotypes in patients with predisposing conditions. Laboratory capacity to identify S. suis in the hospital is needed in developing countries, which can contribute to enhanced surveillance, epidemiological control, and prevention strategies in the prevalent area.
Usha, K; Kumar, E; Kalawat, Usha; Kumar, B Siddhartha; Chaudhury, A; Gopal, D V R Sai
Scrub typhus is a vector-borne zoonotic infection caused by Orientiatsutsugamushi. Local epidemiology of the circulating serotypes of scrub typhus is not available from most parts of India. We conducted this study for the diagnosis of scrub typhus using IgM ELISA and to detect O. tsutsugamushi serotypes circulating in southern Andhra Pradesh, India. Samples were collected from patients clinically suspected to have scrub typhus and were subjected to IgM ELISA to measure IgM antibodies against O. tsutsugamushi. Nested polymerase chain reaction (PCR) was performed targeting strain-specific regions in ELISA-positive samples. Of a total of 663 samples, 258 (38.91%) were found to be positive by IgM ELISA. Serotypes could be detected in 230 (34.69%) samples only. Only two serotypes, Karp and Kawasaki, were found in the serum samples, with the former being predominant. The dual infection of Karp and Kawasaki serotypes was found in seven patients. Other serotypes such as Gilliam, Kuroki and Kato were not detected in the samples. The nested PCR products proved useful in presumptively identifying the endemic O. tsutsugamushi serotypes. The present study could be significant in understanding scrub typhus epidemiology in this region.
Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong
Foot-and-mouth disease is a highly contagious, acute viral disease of cloven-hoofed animal species causing severe economic losses worldwide. Among the seven serotypes of foot-and-mouth disease virus (FMDV), serotype O is predominant, but its viral capsid is more acid sensitive than other serotypes, making it more difficult to produce empty serotype O VLPs in the low pH insect hemolymph. Therefore, a novel chimeric virus-like particle (VLP)-based candidate vaccine for serotype O FMDV was developed and characterized in the present study. The chimeric VLPs were composed of antigenic VP1 from serotype O and segments of viral capsid proteins from serotype Asia1. These VLPs elicited significantly higher FMDV-specific antibody levels in immunized mice than did the inactivated vaccine. Furthermore, the chimeric VLPs protected guinea pigs from FMDV challenge with an efficacy similar to that of the inactivated vaccine. These results suggest that chimeric VLPs have the potential for use in vaccines against serotype O FMDV infection. Copyright © 2015 Elsevier B.V. All rights reserved.
P. G. Howell
Full Text Available Cohorts of yearlings were sampled over a period of 6 years in a retrospective serological survey to establish the annual prevalence of serotype specific antibody to equine encephalosis virus on Thoroughbred stud farms distributed within defined geographical regions of South Africa. Seasonal seroprevalence varied between 3.6% and 34.7%, revealing both single and multiple serotype infections in an individual yearling. During the course of this study serotypes 1 and 6 were most frequently and extensively identified while the remaining serotypes 2, 3, 4, 5 and 7 were all identified as sporadic and localized in fections affecting only individual horses. This study of the seasonal prevalence of equine encephalosis virus has a corollary and serves as a useful model in the seasonal incidence of the serotypes of African horse sickness and bluetongue in regions where the respective diseases are endemic.
Kannika, K; Pisuttharachai, D; Srisapoome, P; Wongtavatchai, J; Kondo, H; Hirono, I; Unajak, S; Areechon, N
This study aimed to biotype Streptococcus agalactiae isolated from tilapia farms in Thailand based on molecular biotyping methods and to determine the correlation between the serotype and virulence of bacteria. In addition to a biotyping (serotyping) technique based on multiplex PCR of cps genes, in this study, we developed multiplex PCR typing of Group B streptococcus (GBS) virulence genes to examine three clusters of virulence genes and their correlation with the pathogenicity of S. agalactiae. The epidemiology of S. agalactiae in Thailand was analysed to provide bacterial genetic information towards a future rational vaccine strategy for tilapia culture systems. Streptococcus agalactiae were isolated from diseased tilapia from different areas of Thailand. A total of 124 S. agalactiae isolates were identified by phenotypic analysis and confirmed by 16S rRNA PCR. Bacterial genotyping was conducted based on (i) molecular serotyping of the capsular polysaccharide (cps) gene cluster and (ii) virulence gene profiling using multiplex PCR analysis of 14 virulence genes (lmb, scpB, pavA, cspA, spb1, cyl, bca, rib, fbsA, fbsB, cfb, hylB, bac and pbp1A/ponA). Only serotypes Ia and III were found in this study; serotype Ia lacks the lmb, scpB and spb1 genes, whereas serotype III lacks only the bac gene. Virulence tests in juvenile Nile tilapia demonstrated a correlation between the pathogenicity of the bacteria and their virulence gene profile, with serotype III showing higher virulence than serotype Ia. Epidemiological analysis showed an almost equal distribution in all regions of Thailand, except serotype III was found predominantly in the southern areas. Only two serotypes of S. agalactiae were isolated from diseased tilapia in Thailand. Serotype Ia showed fewer virulence genes and lower virulence than serotype III. Both serotypes showed a similar distribution throughout Thailand. We identified two major serotypes of S. agalactiae isolates associated with the outbreak in
Aabo, Søren; Christensen, J.P.; Chadfield, M.S.
A. Two serotypes demonstrated intracellular log(10) counts that differed significantly from all other serotypes tested: Salmonella Enteritidis PT4 being 1.5 log(10) colony forming units (CFU) ( 31-fold) higher, and Salmonella Tennessee being 0.7 log(10) CFU (fivefold) lower than the reference strain (P...
Dahlén, G; Gmür, R; Yoshino, T
This study was conducted to reveal phenotypic, serological subtypes and antibiotic susceptibility among fresh isolates of Porphyromonas gingivalis in a Swedish population with periodontitis and periodontal abscess. Fifty-five subgingival strains were isolated and tentatively designated as P. gingivalis from 55 consecutive paper-point samples taken from 51 patients with periodontitis (at least one site with >6-mm pocket depth) in Sweden and were sent in for microbiological evaluation. Eight P. gingivalis strains from periodontal abscesses were also included. Four P. gingivalis strains served as reference and another four type strains were included. The strains were characterized by colony morphology, biochemical tests, enzyme profile, gas-liquid chromatography and antibiotic susceptibility. The strains were further characterized for whole cell protein profiles using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and were identified to serotype by specific monoclonal antibodies. Among the 55 P. gingivalis strains 35 had smooth (S), 13 rough (R) and seven semi-rough colony morphologies. All strains were phenotypically homogeneous in biochemical tests, enzyme profile and antibiotic susceptibility. All strains produced phenylacetic acid and alpha-fucosidase. Almost all (96%) of the subgingival strains, but relatively fewer (62%) of the abscess strains, belonged to serotype A. Two subgingival and three abscess strains were classified as serotype B. No specific SDS-PAGE protein profiles were recorded for the two serotypes. The P. gingivalis strains from Swedish periodontitis cases showed homogeneity in terms of biochemical phenotypes and antibiotic susceptibility patterns. The strains fell into two serotypes, of which serotype A predominated in the periodontitis cases and serotype B was overrepresented in periodontal abscesses.
Thong, K L; Goh, Y L; Radu, S; Noorzaleha, S; Yasin, R; Koh, Y T; Lim, V K E; Rusul, G; Puthucheary, S D
The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia.
Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.
The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.27 to 1.00), indicating that PFGE is very discriminative and that multiple clones of Salmonella serotype Weltevreden exist among clinical and environmental isolates. Strains of one dominant pulsotype (pulsotype X1/X2) appeared to be endemic in this region, as they were consistently recovered from humans with salmonellosis between 1996 and 2001 and from raw vegetables. In addition, the sharing of similar PFGE profiles among isolates from humans, vegetables, and beef provides indirect evidence of the possible transmission of salmonellosis from contaminated raw vegetables and meat to humans. Furthermore, the recurrence of PFGE profile X21 among isolates found in samples of vegetables from one wet market indicated the persistence of this clone. The environment in the wet markets may represent a major source of cross-contamination of vegetables with Salmonella serotype Weltevreden. Antibiotic sensitivity tests showed that the clinical isolates of Salmonella serotype Weltevreden remained drug sensitive but that the vegetable isolates were resistant to at least two antibiotics. To the best of our knowledge, this is the first study to compare clinical and environmental isolates of Salmonella serotype Weltevreden in Malaysia. PMID:12089269
Holman, David H; Wang, Danher; Raviprakash, Kanakatte; Raja, Nicholas U; Luo, Min; Zhang, Jianghui; Porter, Kevin R; Dong, John Y
Dengue virus infections can cause hemorrhagic fever, shock, encephalitis, and even death. Worldwide, approximately 2.5 billion people live in dengue-infested regions with about 100 million new cases each year, although many of these infections are believed to be silent. There are four antigenically distinct serotypes of dengue virus; thus, immunity from one serotype will not cross-protect from infection with the other three. The difficulties that hamper vaccine development include requirements of the natural conformation of the envelope glycoprotein to induce neutralizing immune responses and the necessity of presenting antigens of all four serotypes. Currently, the only way to meet these requirements is to use a mixture of four serotypes of live attenuated dengue viruses, but safety remains a major problem. In this study, we have developed the basis for a tetravalent dengue vaccine using a novel complex adenovirus platform that is capable of expressing multiple antigens de novo. This dengue vaccine is constructed as a pair of vectors that each expresses the premembrane and envelope genes of two different dengue virus serotypes. Upon vaccination, the vaccine expressed high levels of the dengue virus antigens in cells to mimic a natural infection and induced both humoral and cellular immune responses against multiple serotypes of dengue virus in an animal model. Further analyses show the humoral responses were indeed neutralizing against all four serotypes. Our studies demonstrate the concept of mimicking infections to induce immune responses by synthesizing dengue virus membrane antigens de novo and the feasibility of developing an effective tetravalent dengue vaccine by vector-mediated expression of glycoproteins of the four serotypes.
Thong, K. L.; Goh, Y. L.; Radu, S.; Noorzaleha, S.; Yasin, R.; Koh, Y. T.; Lim, V. K. E.; Rusul, G.; Puthucheary, S. D.
The incidence of food-borne salmonellosis due to Salmonella enterica serotype Weltevreden is reported to be on the increase in Malaysia. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of Salmonella serotype Weltevreden strains from humans and the environment. PFGE of XbaI-digested chromosomal DNA from 95 strains of Salmonella serotype Weltevreden gave 39 distinct profiles with a wide range of Dice coefficients (0.2...
Thompson, Kimberly M; Duintjer Tebbens, Radboud J
Prior analyses demonstrated the need for some countries and the Global Polio Eradication Initiative (GPEI) to conduct additional supplemental immunization activities (SIAs) with trivalent oral poliovirus vaccine (tOPV) prior to globally-coordinated cessation of all serotype 2-containing OPV (OPV2 cessation) to prevent the creation of serotype 2 circulating vaccine-derived poliovirus (cVDPV2) outbreaks after OPV2 cessation. The GPEI continues to focus on achieving and ensuring interruption of wild poliovirus serotype 1 (WPV1) and making vaccine choices that prioritize bivalent OPV (bOPV) for SIAs, nominally to increase population immunity to serotype 1, despite an aggressive timeline for OPV2 cessation. We use an existing dynamic poliovirus transmission model of northwest Nigeria and an integrated global model for long-term poliovirus risk management to explore the impact of tOPV vs. bOPV vaccine choices on population immunity and cVDPV2 risks. Using tOPV instead of bOPV for SIAs leads to a minimal decrease in population immunity to transmission of serotypes 1 and 3 polioviruses, but a significantly higher population immunity to transmission of serotype 2 polioviruses. Failure to use tOPV in enough SIAs results in cVDPV2 emergence after OPV2 cessation in both the northwest Nigeria model and the global model. Despite perceptions to the contrary, prioritizing the use of bOPV over tOPV prior to OPV2 cessation does not significantly improve serotype 1 population immunity to transmission. Immunization leaders need to focus on all three poliovirus serotypes to appropriately manage the risks of OPV cessation in the polio endgame. Focusing on population immunity to transmission to interrupt WPV1 transmission and manage pre-OPV cessation risks of cVDPVs, all countries performing poliovirus SIAs should use tOPV up until the time of OPV2 cessation, after which time they should continue to use the OPV vaccine formulation with all remaining serotypes until coordinated global
Dixhoorn, van I.D.E.; Reimert, I.; Middelkoop, J.A.; Bolhuis, J.E.; Wisselink, H.J.; Groot Koerkamp, P.W.G.; Kemp, B.; Stockhofe, Norbert
Until today, anti-microbial drugs have been the therapy of choice to combat bacterial diseases. Resistance against antibiotics is of growing concern in man and animals. Stress, caused by demanding environmental conditions, can reduce immune protection in the host, influencing the onset and outcome
Full Text Available BACKGROUND: We investigated the effect of the 7-valent pneumococcal conjugate vaccine (PCV7 programme in England on serotype-specific carriage and invasive disease to help understand its role in serotype replacement and predict the impact of higher valency vaccines. METHODS AND FINDINGS: Nasopharyngeal swabs were taken from children <5 y old and family members (n=400 2 y after introduction of PCV7 into routine immunization programs. Proportions carrying Streptococcus pneumoniae and serotype distribution among carried isolates were compared with a similar population prior to PCV7 introduction. Serotype-specific case carrier ratios (CCRs were estimated using national data on invasive disease. In vaccinated children and their contacts vaccine-type (VT carriage decreased, but was offset by an increase in non-VT carriage, with no significant overall change in carriage prevalence, odds ratio 1.06 (95% confidence interval 0.76-1.49. The lower CCRs of the replacing serotypes resulted in a net reduction in invasive disease in children. The additional serotypes covered by higher valency vaccines had low carriage but high disease prevalence. Serotype 11C emerged as predominant in carriage but caused no invasive disease whereas 8, 12F, and 22F emerged in disease but had very low carriage prevalence. CONCLUSION: Because the additional serotypes included in PCV10/13 have high CCRs but low carriage prevalence, vaccinating against them is likely to significantly reduce invasive disease with less risk of serotype replacement. However, a few serotypes with high CCRs could mitigate the benefits of higher valency vaccines. Assessment of the effect of PCV on carriage as well as invasive disease should be part of enhanced surveillance activities for PCVs. Please see later in the article for the Editors' Summary.
Pinto, Ana Mafalda; Pereira, Tamegão Aires; Alves, Valquíria; Araújo, António; Lage, Olga Maria
Streptococcus agalactiae, commonly known as group B Streptococcus (GBS), has been recognised as a worldwide causative pathogenic agent of neonatal sepsis, meningitis and pneumonia. To better understand the behaviour of S. agalactiae in pregnant women from a hospital from the North of Portugal, retrospective analyses were performed to describe epidemiological, clinical and microbiological characteristics of the isolates obtained. Based on laboratorial records and the hospital's patient files, a 6-year retrospective study was performed to analyse S. agalactiae isolates from screened pregnant women between 35 and 37 weeks of gestation and hospitalised neonates from pregnant women between 24 and 41 weeks of gestation admitted in Hospital Pedro Hispano. Serotype characterisation was also performed in 67 GBS strains. In 6692 pregnant women between 35 and 37 weeks of gestation screened between 2011 and 2016, a total of 1377 S. agalactiae isolates (21%) were found. A high percentage (40%) of unknown colonisation status among hospitalised neonates from pregnant women between 24 and 41 weeks of gestations was also found. The incidence of neonatal sepsis was 8.7 (95% CI 7.0 to 10.8) cases per 1000 live births. Regarding serotype characterisation, serotype III (22.4%) was the most frequent, followed by serotype Ia (19.4%) and serotypes Ib and V (both with 17.9%). High epidemiological values of GBS colonisation and incidence were found in this study. In Portugal studies on the epidemiology and behaviour of S. agalactiae remain limited, reinforcing the importance and need for S. agalactiae screening across the country. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Turki, Yousra; Mehr, Ines; Ouzari, Hadda; Khessairi, Amel; Hassen, Abdennaceur
Salmonella enterica isolates representing commonly isolated serotypes in Tunisia were analyzed using genotyping and phenotyping methods. ERIC and ITS-PCR applied to 48 Salmonella spp. isolates revealed the presence of 12 and 10 different profiles, respectively. The distribution of profiles among serotypes demonstrated the presence of strains showing an identical fingerprinting pattern. All Salmonella strains used in this study were positive for the sdiA gene. Three Salmonella isolates belonging to serotypes Anatum, Enteritidis and Amsterdam were negative for the invA gene. The spvC gene was detected in thirteen isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Gallinarum and Montevideo. Antibiotic resistance was frequent among the recovered Salmonella isolates belonging to serotypes Anatum, Typhimurium, Enteritidis, Zanzibar and Derby. The majority of these isolates exhibited resistance to at least two antibiotic families. Four multidrug-resistant isolates were recovered from food animals and poultry products. These isolates exhibited not only resistance to tetracycline, sulphonamides, and ampicillin, but also have shown resistance to fluoroquinolones. Common resistance to nalidixic acid, ciprofloxacin and ofloxacin in two S. Anatum and S. Zanzibar strains isolated from raw meat and poultry was also obtained. Furthermore, wastewater and human isolates exhibited frequent resistance to nalidixic acid and tetracycline. Of all isolates, 33.5% were able to form biofilm.
The presence of Salmonella and human pathogens in unpasteurized milk remains a public health hazard. The study reported the phenotypic and molecular characterization of Salmonella serotypes in cow raw milk, cheese and traditional yoghurt marketed for man's consumption in Nigeria. Isolation of Salmonella was done ...
Wang, Ping; Tong, Jing-jing; Ma, Xiu-hua; Song, Feng-li; Fan, Ling; Guo, Cui-mei; Shi, Wei; Yu, Sang-jie; Yao, Kai-hu; Yang, Yong-hong
To investigate the serotypes, antibiotic susceptibilities, and multi-locus sequence type (MLST) profiles of Streptococcus agalactiae (S. agalactiae) in Beijing to provide references for the prevention and treatment of S. agalactiae infections. All isolates were identified using the CAMP test and the latex-agglutination assay and serotyped using a Strep-B-Latex kit, after which they were assessed for antibiotic susceptibility, macrolide-resistance genes, and MLST profiles. In total, 56 S. agalactiae isolates were identified in 863 pregnant women (6.5%). Serotypes Ia, Ib, II, III, and V were identified, among which types III (32.1%), Ia (17.9%), Ib (16.1%), and V (14.3%) were the predominant serotypes. All isolates were susceptible to penicillin and ceftriaxone. The nonsusceptiblity rates measured for erythromycin, clarithromycin, azithromycin, telithromycin, clindamycin, tetracycline, and levofloxacin were 85.7%, 92.9%, 98.2%, 30.4%, 73.2%, 91%, and 39.3%, respectively. We identified 14 sequence types (STs) for the 56 isolates, among which ST19 (30.4%) was predominant. The rate of fluoroquinolone resistance was higher in serotype III than in the other serotypes. Among the 44 erythromycin-resistant isolates, 32 (72.7%) carried ermB. S. agalactiae isolates of the serotypes Ia, Ib, III, and V are common in Beijing. Among the S. agalactiae isolates, the macrolide and clindamycin resistance rates are extremely high. Most of the erythromycin-resistant isolates carry ermB.
Qiu, S; Xu, X; Yang, C; Wang, J; Liang, B; Li, P; Li, H; Yi, S; Liu, H; Cui, X; Wu, Z; Xie, J; Jia, L; Wang, L; Hao, R; Jin, H; Wang, Y; Sun, Y; Song, H
We identified 2912 Shigella isolates from diarrhoeal patients in China during 2003-2013. The most common species was Shigella flexneri (55.3%), followed by Shigella sonnei (44.1%); however, S. sonnei is becoming increasingly prevalent. Among the S. flexneri isolates, serotypes 2a and X variant (-:7,8, E1037) were the two most prevalent serotypes, and serologically atypical isolates were also commonly identified. Overall, S. sonnei, S. flexneri 2a and S. flexneri X variant (-:7,8, E1037) accounted for 76.1% of all Shigella isolates, and their prevalence increased from 54.0% during 2003-2004 to 84.1% during 2011-2013. A change was observed in the serotype distribution of Shigella in China during this period, and we propose an ideal strategy to inform the development of a broadly effective Shigella vaccine candidate. Copyright © 2014 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.
Franco F. Calderaro
Full Text Available Abstract: Streptococcus suis is one of most important pathogens in the swine industry worldwide. Despite its importance, studies of S. suis characterization in South America are still rare. This study evaluates S. suis isolates from distinct Brazilian states, from 1999 to 2004, and its molecular and serological characterization. A total of 174 isolates were studied. S. suis identification was confirmed by PCR and isolates were further serotyped and genotyped by SE-AFLP and amplification of virulence markers. Serotype 1, 2, 3, 4, 7, 18, 22 and 32 were identified among the studied isolates, and only 4% were characterized as non-typeable. The mrp+/epf+/sly+ genotype was the most frequent. The SE-AFLP analysis resulted in 29 patterns distributed in three main clusters with over 65% of genetic similarity. Isolates presented a slight tendency to cluster according to serotype and origin; however, no further correlation with virulence genotypes was observed.
García-Vera, César; Ruiz Andrés, María Ángeles; Arana Navarro, Teresa; Moneo Hernández, Isabel; Castillo Laita, José Antonio; Macipe Costa, Rosa; Revillo Pinilla, María José
To determine the characteristics influencing pneumococcal serotype colonization in healthy pre-school aged children, the distribution of serotypes and their antimicrobial susceptibility, after the introduction of pneumococcal 7-valent conjugate vaccine (VNC-7 v). SUJETOS AND METHODS: Nasopharyngeal samples were collected from children under 6 years of age attending well-child examinations in the province of Zaragoza (Spain). Logistic regression was used to study different variables related to the status of the carriers. Of the 371 children studied 30.7% were found to be carriers. With a vaccine coverage rate of 66%, factors related with presence of pneumococcal carriage were found to be the number of siblings (OR 1.44; CI 95% 1.05-1.97 for each sibling), attending a school or child day care centre (OR 3.99; CI 95% 2.00-7.96) and suffering from a minor upper respiratory tract infection (URTI) (OR 1.72; CI 95% 1.02-2.90). Only 8.7% corresponded to VNC-7 v serotypes. The most common non VNC-7 v serotypes isolated were 19A, 6A, 15B, 11, and 15A. Significantly greater resistance was detected among VNC-7 v serotypes. Children in the setting of this study carried pneumococci more commonly when they have siblings, attend school or day care, or suffer from minor URTI. In the VNC-7 v vaccine era, VNC-7 v serotypes have become rare occurrences (8.7%) and emerging serotypes present better susceptibility to antibiotics. Copyright © 2010 Elsevier España, S.L. All rights reserved.
Russell, Neal J; Seale, Anna C; O'Driscoll, Megan; O'Sullivan, Catherine; Bianchi-Jassir, Fiorella; Gonzalez-Guarin, Juan; Lawn, Joy E; Baker, Carol J; Bartlett, Linda; Cutland, Clare; Gravett, Michael G; Heath, Paul T; Le Doare, Kirsty; Madhi, Shabir A; Rubens, Craig E; Schrag, Stephanie; Sobanjo-Ter Meulen, Ajoke; Vekemans, Johan; Saha, Samir K; Ip, Margaret
Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide. We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels. The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia. GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts. © The Author 2017. Published by
Dr. Cynthia Whitney, a CDC medical doctor and Epidemiologist, discusses serotype 12F pneumoniae. Created: 2/8/2018 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 2/8/2018.
Full Text Available We developed a lateral flow strip using monoclonal antibodies (MAbs which allows for rapid antigen detection and serotyping of foot-and-mouth disease virus (FMDV. This FMDV serotyping strip was able to detect all 7 serotypes and distinguish serotypes O, A, C and Asia1. Its sensitivities ranged from 10(3 to 10(4 of a 50% tissue culture infectious dose of each FMDV stain; this is equal to those of the commercial product Svanodip (Boehringer Ingelheim Svanova, Uppsala, Sweden, which can detect all seven serotypes of FMDV, but does not distinguish them. Our evaluation of the FMDV serotyping strip using a total of 118 clinical samples (vesicular fluids, vesicular epithelial emulsions and oral and/or nasal swabs showed highly sensitive antigen detection and accuracy in serotyping in accordance with ELISA or RT-PCR. To the best of our knowledge, this is the first report on any FMDV serotyping strip that provides both rapid antigen detection and serotyping of FMDV at the same time on one strip without extra devices. This method will be useful in both FMD-free countries and FMD-infected countries, especially where laboratory diagnosis cannot be carried out.
Dr DADIE Thomas
Feb 17, 2014 ... The virulence, serotype and phylogenetic traits of diarrhoeagenic Escherichia coli were detected in 502 strains isolated during digestive infections. Molecular detection of the target virulence genes, rfb gene of operon O and phylogenetic grouping genes Chua, yjaA and TSPE4.C2 was performed.
Marluísa de Oliveira Guimarães Ishak
Full Text Available INTRODUCTION: Chlamydia infection is associated with debilitating human diseases including trachoma, pneumonia, coronary heart disease and urogenital diseases. Serotypes of C. trachomatis show a fair correlation with the group of diseases they cause, and their distribution follows a well-described geographic pattern. Serotype A, a trachoma-associated strain, is known for its limited dissemination in the Middle East and Northern Africa. However, knowledge on the spread of bacteria from the genus Chlamydia as well as the distribution of serotypes in Brazil is quite limited. METHODS: Blood samples of 1,710 individuals from ten human population groups in the Amazon region of Brazil were examined for antibodies to Chlamydia using indirect immunofluorescence and microimmunofluorescence assays. RESULTS: The prevalence of antibodies to Chlamydia ranged from 23.9% (Wayana-Apalai to 90.7% (Awa-Guaja with a mean prevalence of 50.2%. Seroreactivity was detected to C. pneumoniae and to all serotypes of C. trachomatis tested; furthermore, we report clear evidence of the as-yet-undescribed occurrence of serotype A of C. trachomatis. CONCLUSIONS: Specific seroreactivity not only accounts for the large extent of dissemination of C. trachomatis in the Amazon region of Brazil but also shows an expanded area of occurrence of serotype A outside the epidemiological settings previously described. Furthermore, these data suggest possible routes of Chlamydia introduction into the Amazon region from the massive human migration that occurred during the 1,700s.
Khanam, Saima; Rajendra, Pilankatta; Khanna, Navin; Swaminathan, Sathyamangalam
Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. It is a mosquito-borne viral disease, caused by dengue (DEN) viruses, which are members of the Flaviviridae family. There are four closely related serotypes, DEN-1, DEN-2, DEN-3 and DEN-4, each of which is capable of causing disease. As immunity to any one serotype can potentially sensitize an individual to severe disease during exposure to a heterologous serotype, the general consensus is that an effective vaccine should be tetravalent, that is, it must be capable of affording protection against all four serotypes. The current strategy of creating tetravalent vaccine formulations by mixing together four monovalent live attenuated vaccine viruses has revealed the phenomenon of viral interference leading to the manifestation of immune responses biased towards a single serotype. This work stems from the emergence of (i) the DEN virus envelope (E) domain III (EDIII) as the most important region of the molecule from a vaccine perspective and (ii) the adenovirus (Ad) as a promising vaccine vector platform. We describe the construction of a recombinant, replication-defective Ad (rAd) vector encoding a chimeric antigen made of in-frame linked EDIIIs of DEN virus serotypes 2 and 4. Using this rAd vector, in conjunction with a plasmid vector encoding the same chimeric bivalent antigen, in a prime-boost strategy, we show that it is possible to elicit equipotent neutralizing and T cell responses specific to both DEN serotypes 2 and 4. Our data support the hypothesis that a DEN vaccine targeting more than one serotype may be based on a single DNA-based vector to circumvent viral interference. This work lays the foundation for developing a single Ad vector encoding EDIIIs of all four DEN serotypes to evoke a balanced immune response against each one of them. Thus, this work has implications for the development of safe and effective
Full Text Available Abstract Background Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. It is a mosquito-borne viral disease, caused by dengue (DEN viruses, which are members of the Flaviviridae family. There are four closely related serotypes, DEN-1, DEN-2, DEN-3 and DEN-4, each of which is capable of causing disease. As immunity to any one serotype can potentially sensitize an individual to severe disease during exposure to a heterologous serotype, the general consensus is that an effective vaccine should be tetravalent, that is, it must be capable of affording protection against all four serotypes. The current strategy of creating tetravalent vaccine formulations by mixing together four monovalent live attenuated vaccine viruses has revealed the phenomenon of viral interference leading to the manifestation of immune responses biased towards a single serotype. Results This work stems from the emergence of (i the DEN virus envelope (E domain III (EDIII as the most important region of the molecule from a vaccine perspective and (ii the adenovirus (Ad as a promising vaccine vector platform. We describe the construction of a recombinant, replication-defective Ad (rAd vector encoding a chimeric antigen made of in-frame linked EDIIIs of DEN virus serotypes 2 and 4. Using this rAd vector, in conjunction with a plasmid vector encoding the same chimeric bivalent antigen, in a prime-boost strategy, we show that it is possible to elicit equipotent neutralizing and T cell responses specific to both DEN serotypes 2 and 4. Conclusion Our data support the hypothesis that a DEN vaccine targeting more than one serotype may be based on a single DNA-based vector to circumvent viral interference. This work lays the foundation for developing a single Ad vector encoding EDIIIs of all four DEN serotypes to evoke a balanced immune response against each one of them. Thus, this work has
Sangula, Abraham; Belsham, Graham; Muwanika, Vincent
Amongst the SAT serotypes of foot-and-mouth disease virus (FMDV), the SAT 2 serotype is the most widely distributed throughout sub-Saharan Africa. Kenyan serotype SAT 2 viruses have been reported to display the highest genetic diversity for the serotype globally. This complicates diagnosis...... and control, and it is essential that patterns of virus circulation are known in order to overcome these difficulties. This study was undertaken to establish patterns of evolution of FMDV serotype SAT 2 in Kenya using complete VP1 coding sequences in a dataset of 65 sequences from Africa, collected over...
Walter H B Demczuk
Full Text Available Since implementation of the 13-valent polyvalent conjugate vaccine (PCV13 in Canada during 2010, the proportion of PCV13 serotypes causing invasive pneumococcal disease (IPD has declined from 55% (n = 1492 in 2010 to 31% (n = 764 in 2014. A concurrent increase of non-PCV13 serotypes has occurred and 22F has become the most prevalent serotype in Canada increasing from 7% (n = 183 to 11% (n = 283. Core single nucleotide variant phylogenetic analysis was performed on 137 Streptococcus pneumoniae serotype 22F isolates collected across Canada from 2005-2015. Six phylogenetic lineages (n = 117 were identified among a serotype 22F/ST433 clonal complex (CC, including a recently expanding erythromycin-resistant clone. Erythromycin-resistance was observed in 25 isolates possessing ermB, mef or a 23S rRNA A2061G point mutation; 2 penicillin-resistant isolates had recombinant pbp1a, pbp2a and/or pbp2x; 3 tetracycline-resistant isolates contained tetM; and 1 isolate was multidrug-resistant. Virulence factor analysis indicated a high level of homogeneity among the 22F/ST433 clonal complex strains. A group of 6 phylogenetic outlier strains had differing MLST, antimicrobial resistance and molecular profiles suggestive of capsule switching events. While capsule switch events among S. pneumoniae serotype 22F has been observed, increasing prevalence of S. pneumoniae serotype 22F can be attributed to an evolving homogenous clone expanding nationally through local transmission events.
Guo, Xi; Wang, Min; Wang, Lu; Wang, Yao; Chen, Tingting; Wu, Pan; Chen, Min; Liu, Bin; Feng, Lu
Serotyping based on surface polysaccharide antigens is important for the clinical detection and epidemiological surveillance of pathogens. Polysaccharide gene clusters (PSgcs) are typically responsible for the diversity of bacterial surface polysaccharides. Through whole-genome sequencing and analysis, eight putative PSgc types were identified in 23 Enterobacter aerogenes strains from several geographic areas, allowing us to present the first molecular serotyping system for E. aerogenes . A conventional antigenic scheme was also established and correlated well with the molecular serotyping system that was based on PSgc genetic variation, indicating that PSgc-based molecular typing and immunological serology provide equally valid results. Further, a multiplex Luminex-based array was developed, and a double-blind test was conducted with 97 clinical specimens from Shanghai, China, to validate our array. The results of these analyses indicated that strains containing PSgc4 and PSgc7 comprised the predominant groups. We then examined 86 publicly available E. aerogenes strain genomes and identified an additional seven novel PSgc types, with PSgc10 being the most abundant type. In total, our study identified 15 PSgc types in E. aerogenes , providing the basis for a molecular serotyping scheme. From these results, differing epidemic patterns were identified between strains that were predominant in different regions. Our study highlights the feasibility and reliability of a serotyping system based on PSgc diversity, and for the first time, presents a molecular serotyping system, as well as an antigenic scheme for E. aerogenes , providing the basis for molecular diagnostics and epidemiological surveillance of this important emerging pathogen.
Full Text Available BACKGROUND: Serotype-specific PCR assays targeting Salmonella enterica serotypes Typhi and Paratyphi A, the causal agents of typhoid and paratyphoid fevers, are required to accelerate formal diagnosis and to overcome the lack of typing sera and, in some situations, the need for culture. However, the sensitivity and specificity of such assays must be demonstrated on large collections of strains representative of the targeted serotypes and all other bacterial populations producing similar clinical symptoms. METHODOLOGY: Using a new family of repeated DNA sequences, CRISPR (clustered regularly interspaced short palindromic repeats, as a serotype-specific target, we developed a conventional multiplex PCR assay for the detection and differentiation of serotypes Typhi and Paratyphi A from cultured isolates. We also developed EvaGreen-based real-time singleplex PCR assays with the same two sets of primers. PRINCIPAL FINDINGS: We achieved 100% sensitivity and specificity for each protocol after validation of the assays on 188 serotype Typhi and 74 serotype Paratyphi A strains from diverse genetic groups, geographic origins and time periods and on 70 strains of bacteria frequently encountered in bloodstream infections, including 29 other Salmonella serotypes and 42 strains from 38 other bacterial species. CONCLUSIONS: The performance and convenience of our serotype-specific PCR assays should facilitate the rapid and accurate identification of these two major serotypes in a large range of clinical and public health laboratories with access to PCR technology. These assays were developed for use with DNA from cultured isolates, but with modifications to the assay, the CRISPR targets could be used in the development of assays for use with clinical and other samples.
Full Text Available Abstract A reverse transcriptase loop-mediated isothermal amplification (RT-LAMP assay was rapidly used to detect serotype Asia 1 of foot-and-mouth disease virus (FMDV within 45 min at 61°C. All FMDV serotype Asia 1 reference strains were positive by RT-LAMP, while other viruses such as FMDV serotypes O, C, A and classical swine fever virus, swine vesicular disease virus, porcine reproductive and respiratory syndrome virus and Japanese encephalitis virus remained negative. Furthermore, FMDV sreotype Asia 1 positive samples were able to detect by RT-LAMP assay. This RT-LAMP assay may be suitable particularly for diagnosis of FMDV serotype Asia 1 infection in field stations.
Hannemann, Holger; Sung, Po-Yu; Chiu, Han-Chen; Yousuf, Amjad; Bird, Jim; Lim, Siew Pheng; Davidson, Andrew D.
The four serotypes of dengue virus (DENV-1 to -4) cause the most important arthropod-borne viral disease of humans. DENV non-structural protein 5 (NS5) contains enzymatic activities required for capping and replication of the viral RNA genome that occurs in the host cytoplasm. However, previous studies have shown that DENV-2 NS5 accumulates in the nucleus during infection. In this study, we examined the nuclear localization of NS5 for all four DENV serotypes. We demonstrate for the first time that there are serotypic differences in NS5 nuclear localization. Whereas the DENV-2 and -3 proteins accumulate in the nucleus, DENV-1 and -4 NS5 are predominantly if not exclusively localized to the cytoplasm. Comparative studies on the DENV-2 and -4 NS5 proteins revealed that the difference in DENV-4 NS5 nuclear localization was not due to rapid nuclear export but rather the lack of a functional nuclear localization sequence. Interaction studies using DENV-2 and -4 NS5 and human importin-α isoforms failed to identify an interaction that supported the differential nuclear localization of NS5. siRNA knockdown of the human importin-α isoform KPNA2, corresponding to the murine importin-α isoform previously shown to bind to DENV-2 NS5, did not substantially affect DENV-2 NS5 nuclear localization, whereas knockdown of importin-β did. The serotypic differences in NS5 nuclear localization did not correlate with differences in IL-8 gene expression. The results show that NS5 nuclear localization is not strictly required for virus replication but is more likely to have an auxiliary function in the life cycle of specific DENV serotypes. PMID:23770669
Hannemann, Holger; Sung, Po-Yu; Chiu, Han-Chen; Yousuf, Amjad; Bird, Jim; Lim, Siew Pheng; Davidson, Andrew D
The four serotypes of dengue virus (DENV-1 to -4) cause the most important arthropod-borne viral disease of humans. DENV non-structural protein 5 (NS5) contains enzymatic activities required for capping and replication of the viral RNA genome that occurs in the host cytoplasm. However, previous studies have shown that DENV-2 NS5 accumulates in the nucleus during infection. In this study, we examined the nuclear localization of NS5 for all four DENV serotypes. We demonstrate for the first time that there are serotypic differences in NS5 nuclear localization. Whereas the DENV-2 and -3 proteins accumulate in the nucleus, DENV-1 and -4 NS5 are predominantly if not exclusively localized to the cytoplasm. Comparative studies on the DENV-2 and -4 NS5 proteins revealed that the difference in DENV-4 NS5 nuclear localization was not due to rapid nuclear export but rather the lack of a functional nuclear localization sequence. Interaction studies using DENV-2 and -4 NS5 and human importin-α isoforms failed to identify an interaction that supported the differential nuclear localization of NS5. siRNA knockdown of the human importin-α isoform KPNA2, corresponding to the murine importin-α isoform previously shown to bind to DENV-2 NS5, did not substantially affect DENV-2 NS5 nuclear localization, whereas knockdown of importin-β did. The serotypic differences in NS5 nuclear localization did not correlate with differences in IL-8 gene expression. The results show that NS5 nuclear localization is not strictly required for virus replication but is more likely to have an auxiliary function in the life cycle of specific DENV serotypes.
Full Text Available BACKGROUND: Apolipoprotein E (ApoE typing is considered important because of the association between ApoE and Alzheimer's disease and familial dyslipidemia and is currently performed by genetic testing (APOE genotyping. ApoE levels in plasma and serum are clinically determined by immunoassay. METHODS: Combining an ApoE immunoassay reagent with proteomic analysis using an Orbitrap mass spectrometer, we attempted to resequence ApoE from trace amounts of serum for typing (serotyping. Most (24 of 33 ApoE mutant proteins registered to date with Online Mendelian Inheritance in Man, such as ApoE2 and ApoE4, involve lysine and arginine mutations. Digestion of mutant ApoE with trypsin will thus result in fragments that differ substantially from wild-type ApoE3 in terms of mass, making serotyping ideally suited to mass spectrometry analysis. RESULTS: The mean coverage of the amino acid sequence of full-length ApoE was 91.6% in the protein resequence. Residues 112 and 158 (which are mutated in ApoE2 and ApoE4 were covered in all samples, and the protein sequences were used for serotyping. Serotypes including all heterozygous combinations (ApoE2/E3, E2/E4, E3/E4 corresponded exactly to the APOE genotyping results in each of the subjects. CONCLUSION: Our novel ApoE serotyping method with protein resequencing requires no synthesis of stable isotope-labeled peptides or genome analysis. The method can use residual blood from samples collected for routine clinical tests, thus enabling retrospective studies with preserved body fluids. The test could be applied to samples from subjects whose DNA is unavailable. In future studies, we hope to demonstrate the capability of our method to detect rare ApoE mutations.
Full Text Available A hospital-based surveillance of shigellosis was conducted in Taiyuan from 2005 to 2015. A total of 2655 stool cultures were collected from patients with diarrhea, 115 were identified as S. flexneri and 107 were S. sonnei. The highest infection rates were found among children under 5 years of age (34.2 %, and during the summer (61.0 %. Six serotypes were identified among S. flexneriisolates:1a, 2a, 2b, Xv, X and Y. Serotype 2a and Xv were the dominant serotypes in two periods, 2012–2015 and 2005–2008, respectively. High shigellosis rates over the past decade highlight shigellosis is still a major public health problem in Taiyuan. Keywords: Shigellosis, Shigella, Infection rate, Serotypes, Molecular serotyping
Grant, Clare F J; Carr, B Veronica; Kotecha, Abhay; van den Born, Erwin; Stuart, David I; Hammond, John A; Charleston, Bryan
Foot-and-mouth disease virus (FMDV) is a highly contagious viral disease. Antibodies are pivotal in providing protection against FMDV infection. Serological protection against one FMDV serotype does not confer interserotype protection. However, some historical data have shown that interserotype protection can be induced following sequential FMDV challenge with multiple FMDV serotypes. In this study, we have investigated the kinetics of the FMDV-specific antibody-secreting cell (ASC) response following homologous and heterologous inactivated FMDV vaccination regimes. We have demonstrated that the kinetics of the B cell response are similar for all four FMDV serotypes tested following a homologous FMDV vaccination regime. When a heterologous vaccination regime was used with the sequential inoculation of three different inactivated FMDV serotypes (O, A, and Asia1 serotypes) a B cell response to FMDV SAT1 and serotype C was induced. The studies also revealed that the local lymphoid tissue had detectable FMDV-specific ASCs in the absence of circulating FMDV-specific ASCs, indicating the presence of short-lived ASCs, a hallmark of a T-independent 2 (TI-2) antigenic response to inactivated FMDV capsid. IMPORTANCE We have demonstrated the development of intraserotype response following a sequential vaccination regime of four different FMDV serotypes. We have found indication of short-lived ASCs in the local lymphoid tissue, further evidence of a TI-2 response to FMDV. Copyright © 2017 American Society for Microbiology.
Dierickx, K; Pauwels, M; Laine, ML; Van Eldere, J; Cassiman, JJ; van Winkelhoff, AJ; van Steenberghe, D; Quirynen, M
Background: Porphyromonas gingivalis, a key pathogen in periodontitis, is able to adhere to and invade the pocket epithelium. Different capsular antigens of P gingivalis have been identified (K-serotyping). These P gingivalis capsular types show differences in adhesion capacity to human cell lines
Bruun, B; Gahrn-Hansen, B; Westh, H
Surveillance performed after the introduction of general Haemophilus influenzae serotype b (Hib) vaccination in Denmark identified 13 cases of invasive bacteraemic H. influenzae serotype f (Hif) disease in adults over a period of 7 years. Bacteraemic respiratory tract infections accounted for 61...... sequences. Multilocus enzyme electrophoresis typing revealed that recent Danish and American isolates belonged to a single Hif clone, which may be undergoing expansion. The need for accurate serotyping of H. influenzae to enable reliable monitoring for Hib replacement by other capsular types is emphasized....
Paula S Montenegro-Miranda
Full Text Available Preclinical studies in mice and non-human primates showed that AAV serotype 5 provides efficient liver transduction and as such seems a promising vector for liver directed gene therapy. An advantage of AAV5 compared to serotype 8 already shown to provide efficient correction in a phase 1 trial in patients suffering from hemophilia B, is its lower seroprevalence in the general population. Our goal is liver directed gene therapy for Crigler-Najjar syndrome type I, inherited severe unconjugated hyperbilirubinemia caused by UGT1A1 deficiency. In a relevant animal model, the Gunn rat, we compared the efficacy of AAV 5 and 8 to that of AAV1 previously shown to be effective. Ferrying a construct driving hepatocyte specific expression of UGT1A1, both AAV8 and AAV1 provided an efficient correction of hyperbilirubinemia. In contrast to these two and to other animal models AAV5 failed to provide any correction. To clarify whether this unexpected finding was due to the rat model used or due to a problem with AAV5, the efficacy of this serotype was compared in a mouse and two additional rat strains. Administration of an AAV5 vector expressing luciferase under the control of a liver specific promoter confirmed that this serotype poorly performed in rat liver, rendering it not suitable for proof of concept studies in this species.
World-wide there are at least 24 serotypes of bluetongue virus (BTV), a complex non-enveloped virus in the family Reoviridae, genus Orbivirus. Bluetongue (BT) is an arthropod-borne disease of cattle, sheep, goats, and deer and is transmitted by Culicoides biting midges. In 2006, bluetongue serotype ...
Full Text Available Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp. The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains of Lomita (6, Derby (4, Senftenberg (2, Javiana and Cannsttat (1 and undeter- mined (5 serotypes. The strains showed a high resistance rate to ampicillin (18/19, carbenicillin (16/19, tetracyclin (13/19, and trimethoprim-sulfamethoxazole (13/19. Multidrug resistance was observed in 14 isolates. Conclusions. Several Salmonella spp. serotypes of public health significance are circulating in ground beef sold in the major Mexican city. Some of these strains are multi-drug resistance.
Fulton, R W; Pearson, N J
The interferon inducing ability of bluetongue viruses was studied in bovine and feline monolayer cultures inoculated with each of four bluetongue virus serotypes. Interferon was assayed by a plaque reduction method in monolayer cultures with vesicular stomatitis virus as challenge virus. Interferon was produced by bovine turbinate, Georgia bovine kidney, and Crandell feline kidney monolayer cultures in response to bluetongue virus serotypes 10, 11, 13 and 17. The antiviral substances produced...
Barley yellow dwarf luteovirus (BYDV) serotypes PAV and RPV were identified from irrigated wheat (Triticum aestivum L.) samples from three provinces of Zambia by double antibody sandwich enzyme-linked immunosorbent assay using polyclonal and monoclonal antisera. Nine wheat cultivars were surveyed in 11 wheat ...
Becker, P.M.; Wikselaar, van P.G.; Mul, M.F.; Pol, A.; Engel, B.; Wijdenes, J.W.; Peet-Schwering, van der C.M.C.; Wisseling, H.J.; Stockhofe-Zurwieden, N.
Decomposition products of ingested garlic are to a certain extent excreted via the lungs. If the supposed health-supporting capacities associated with garlic extend to these exhaled sulfurous compounds, they could have an effect on the course of pneumonia. In this study, the garlic-derived volatile
Botulism is a serious foodborne neuroparalyic disease caused by botulinum neurotoxin (BoNT) produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We repo...
Ingle, Danielle J; Valcanis, Mary; Kuzevski, Alex; Tauschek, Marija; Inouye, Michael; Stinear, Tim; Levine, Myron M; Robins-Browne, Roy M; Holt, Kathryn E
The lipopolysaccharide (O) and flagellar (H) surface antigens of Escherichia coli are targets for serotyping that have traditionally been used to identify pathogenic lineages. These surface antigens are important for the survival of E. coli within mammalian hosts. However, traditional serotyping has several limitations, and public health reference laboratories are increasingly moving towards whole genome sequencing (WGS) to characterize bacterial isolates. Here we present a method to rapidly and accurately serotype E. coli isolates from raw, short read WGS data. Our approach bypasses the need for de novo genome assembly by directly screening WGS reads against a curated database of alleles linked to known and novel E. coli O-groups and H-types (the EcOH database) using the software package srst2. We validated the approach by comparing in silico results for 197 enteropathogenic E. coli isolates with those obtained by serological phenotyping in an independent laboratory. We then demonstrated the utility of our method to characterize isolates in public health and clinical settings, and to explore the genetic diversity of >1500 E. coli genomes from multiple sources. Importantly, we showed that transfer of O- and H-antigen loci between E. coli chromosomal backbones is common, with little evidence of constraints by host or pathotype, suggesting that E. coli ' strain space' may be virtually unlimited, even within specific pathotypes. Our findings show that serotyping is most useful when used in combination with strain genotyping to characterize microevolution events within an inferred population structure.
Stephen D Bentley
Full Text Available Several major invasive bacterial pathogens are encapsulated. Expression of a polysaccharide capsule is essential for survival in the blood, and thus for virulence, but also is a target for host antibodies and the basis for effective vaccines. Encapsulated species typically exhibit antigenic variation and express one of a number of immunochemically distinct capsular polysaccharides that define serotypes. We provide the sequences of the capsular biosynthetic genes of all 90 serotypes of Streptococcus pneumoniae and relate these to the known polysaccharide structures and patterns of immunological reactivity of typing sera, thereby providing the most complete understanding of the genetics and origins of bacterial polysaccharide diversity, laying the foundations for molecular serotyping. This is the first time, to our knowledge, that a complete repertoire of capsular biosynthetic genes has been available, enabling a holistic analysis of a bacterial polysaccharide biosynthesis system. Remarkably, the total size of alternative coding DNA at this one locus exceeds 1.8 Mbp, almost equivalent to the entire S. pneumoniae chromosomal complement.
Yang, Zhuona; Jiang, Min; Li, Jian; Fang, Xiaojiang; Ye, Guizi; Bai, Xuefei; Zheng, Xiaoyu; Wei, Ping
Different neutralizing agents were used as pH controller to investigate their effects on the growth and succinic acid production of Actinobacillus succinogenes NJ113. The fermentation results showed that Ca(OH)2, CaCO3 and NH4OH were not suitable for succinic acid production by A. succinogenes NJ113 because of their negative effects on cell growth. When Na-base was used, cells would flocculate and lump, and due to the sodium ion concentration reaching to a high level, OD660 dropped sharply after 12 h of fermentation. Mg-base was better because there was no significant inhibition by magnesium ion. Two combined neutralizing agents were used to maintain pH level, one with NaOH and Mg(OH)2 while the other with Na2CO3 and Mg(OH)2. The optimum ratios of the combined neutralizing agents were both 1:1 (g:g) when using 100 g/L glucose. When NaOH and Mg(OH)2 were chosen with the ratio of 1:1(g:g), 69.8 g/L of the succinic acid and 74.5% of the yield was obtained.
LEUKOTOXIC ACTIVITY OF ACTINOBACILLUS ACTINOMYCETEMCOMITANS ISOLATED FROM HUMAN AND NON-HUMAN PRIMATES Atividade leucotóxica de amostras de Actinobacillus actinomycetemcomitans de primatas humanos não-humanos
Francisca Lúcia de Lima
Full Text Available Actinobacillus actinomycetemcomitans is a clinically relevant periodontopathogenic Gram-negative coccobacillus that produces a leukotoxin of the RTX cytolysin family. In this study, we evaluated the leukotoxic activity of A. actinomycetemcomitans strains isolated from human and marmosets by Trypan blue exclusion and by the chemiluminescence assays. Among eight A. actinomycetemcomitans human strains studied, two (P2.17 and P8.12 were classified as high leukotoxin producers and among eight marmoset strains, one (M22.11 showed high leukotoxin production, as determined by Trypan blue exclusion assay. The reference strains ATCC 29523 and FDC Y4 respectively behaved like moderate and low producers. The chemiluminescence assay was used to evaluate the leukotoxic activity of M22.11 and P2.17 strains submitted to different growth conditions. Leukotoxic activity was detected on cells at the logarithmic phase and was similar under anaerobic and microaerophilic growth conditions. It was greatly reduced when cells were grown at glucose concentrations lower or higher than 0.75% (0.25% and 1.5% in thioglycolate medium. Leukotoxin production mainly by the M22.11 strain was low in BHI broth, whereas production in TSB medium showed a similar level as in thioglycolate broth medium. Sodium bicarbonate at 10 mM did not affect leukotoxin production.Actinobacillus actinomycetemcomitans é um cocobacilo Gram negativo, periodontopatógeno clinicamente importante, que produz uma leucotoxina pertencente à família das citolisinas RTX. Neste estudo, avaliou-se a atividade leucotóxica de amostras de A. actinomycetemcomitans isoladas de seres humanos e de calitriquídeos pelos métodos de exclusão de azul de Tripan e quimioluminescência. Duas (P2.17 e P8.12 entre oito amostras de A. actinomycetemcomitans isoladas de seres humanos, e uma (M22.11 entre 8 amostras isoladas de sagüis se apresentaram como altamente produtoras de leucotoxina, como determinado pelo teste de
Routsias, John G; Mavrouli, Maria D; Antonaki, Georgia; Spanakis, Nikolaos; Tsakris, Athanassios
Enteroviruses are important human pathogens, causing a broad spectrum of diseases from minor common colds to fatal myocarditis. However, certain disease syndromes are caused by one or few serotypes. Serotype identification is difficult due to the laborious neutralization tests that lack of sensitivity, while in commercial ELISAs homotypic antibodies' activities are largely masked by the recognition of genera-specific epitopes by heterotypic antibodies. In the present study homotypic assays were developed with the ability to discriminate different enterovirus serotypes. Seventy-three children sera, positive for IgM antibodies against enterovirus genus and 49 healthy children were examined for the presence of antibodies against 14 synthetic peptides derived from a non-conserved region of the VP1 protein of coxsackieviruses B2, B3, B4, B5, A9, A16, A24, echoviruses 6, 7, 9, 11, 30, enterovirus 71 and parechovirus 1. 50% of the anti-enterovirus IgM positive sera (>150 BU) reacted with the peptides with the majority of them to preferentially recognize one of them, supporting the homotypic nature of our assay. Inhibition studies yielded homologous inhibition rates 67-95% suggesting that specific peptide recognition actually occurred. The diagnostic value of our assay was tested in blood samples drawn over a 1.5-year period from a 5-year old patient. The anti-enterovirus reactivity was clearly attributed to echovirus serotype 11. The IgM/IgG antibody ratio was reversed 4 months later and subsequently IgM antibodies dropped below the cutoff point. In this paper we demonstrate that our assay can be used to discriminate between antibodies targeting different enterovirus serotypes. Copyright © 2014 Elsevier Inc. All rights reserved.
Wang, Jinhui; Faust, Susan M; Rabinowitz, Joseph E
Delivery is at the heart of gene therapy. Viral DNA delivery systems are asked to avoid the immune system, transduce specific target cell types while avoiding other cell types, infect dividing and non-dividing cells, insert their cargo within the host genome without mutagenesis or to remain episomal, and efficiently express transgenes for a substantial portion of a lifespan. These sought-after features cannot be associated with a single delivery system, or can they? The Adeno-associated virus family of gene delivery vehicles has proven to be highly malleable. Pseudotyping, using AAV serotype 2 terminal repeats to generate designer shells capable of transducing selected cell types, enables the packaging of common genomes into multiple serotypes virions to directly compare gene expression and tropism. In this review the ability to manipulate this virus will be examined from the inside out. The influence of host cell factors and organism biology including the immune response on the molecular fate of the viral genome will be discussed as well as differences in cellular trafficking patterns and uncoating properties that influence serotype transduction. Re-engineering the prototype vector AAV2 using epitope insertion, chemical modification, and molecular evolution not only demonstrated the flexibility of the best-studied serotype, but now also expanded the tool kit for molecular modification of all AAV serotypes. Current AAV research has changed its focus from examination of wild-type AAV biology to the feedback of host cell/organism on the design and development of a new generation of recombinant AAV delivery vehicles. This article is part of a Special Section entitled "Special Section: Cardiovascular Gene Therapy". Copyright © 2010 Elsevier Ltd. All rights reserved.
Yang, Baolin; Wang, Mingxia; Liu, Wenming; Xu, Zhiqiang; Wang, Haiwei; Yang, Decheng; Ma, Wenge; Zhou, Guohui; Yu, Li
Foot-and-mouth disease (FMD), caused by foot-and-mouth disease virus (FMDV), is a highly contagious infectious disease that affects domestic and wild cloven-hoofed animals worldwide. VP2 is a structural protein of FMDV. In this study, an FMDV serotype-independent monoclonal antibody (MAb), 10B10, against the viral capsid protein VP2 was generated, and a series of GST fusion proteins expressing a truncated peptide of VP2 was subjected to Western blot analysis using MAb 10B10. Their results indicated that the peptide 8 TLLEDRILT 16 of VP2 is the minimal requirement of the epitope recognized by MAb 10B10. Importantly, this linear epitope was highly conserved among all seven serotypes of FMDV in a sequence alignment analysis. Subsequent alanine-scanning mutagenesis analysis revealed that the residues Thr 8 and Asp 12 of the epitope were crucial for MAb-10B10 binding. Furthermore, Western blot analysis also revealed that the MAb 10B10-directed epitope could be recognized by positive sera from FMDV-infected cattle. The discovery that MAb 10B10 recognizes a serotype-independent linear epitope of FMDV suggests potential applications for this MAb in the development of serotype-independent tests for FMDV.
Lauri, Andrea; Castiglioni, Bianca; Mariani, Paola
Salmonella is a major cause of food-borne disease, and Salmonella enterica subspecies I includes the most clinically relevant serotypes. Salmonella serotype determination is important for the disease etiology assessment and contamination source tracking. This task will be facilitated by the disclosure of Salmonella serotype sequence polymorphisms, here annotated in seven genes (sefA, safA, safC, bigA, invA, fimA, and phsB) from 139 S. enterica strains, of which 109 belonging to 44 serotypes of subsp. I. One hundred nineteen polymorphic sites were scored and associated to single serotypes or to serotype groups belonging to S. enterica subsp. I. A diagnostic tool was constructed based on the Ligation Detection Reaction-Universal Array (LDR-UA) for the detection of polymorphic sites uniquely associated to serotypes of primary interest (Salmonella Hadar, Salmonella Infantis, Salmonella Enteritidis, Salmonella Typhimurium, Salmonella Gallinarum, Salmonella Virchow, and Salmonella Paratyphi B). The implementation of promiscuous probes allowed the diagnosis of ten further serotypes that could be associated to a unique hybridization pattern. Finally, the sensitivity and applicability of the tool was tested on target DNA dilutions and with controlled meat contamination, allowing the detection of one Salmonella CFU in 25 g of meat.
Qiu, Fang-Zhou; Shen, Xin-Xin; Zhao, Meng-Chuan; Zhao, Li; Duan, Su-Xia; Chen, Chen; Qi, Ju-Ju; Li, Gui-Xia; Wang, Le; Feng, Zhi-Shan; Ma, Xue-Jun
Human adenovirus (HAdV) serotypes 2, 3 and 7 are more prevalent than other serotypes and have been associated with severe pneumonia in pediatric children. Molecular typing of HAdV is not routinely performed in clinical diagnostic laboratories as it is time-consuming and labor-intensive. In the present study, we developed a triplex quantitative real-time PCR assay (tq-PCR) in a single closed tube for differential detection and quantitative analysis of HAdV serotypes 2, 3 and 7. The sensitivity, specificity, reproducibility and clinical performance of tq-PCR were evaluated. The analytical sensitivity of the tq-PCR was 100 copies/reaction for each of HAdV serotypes 2, 3 and 7, and no cross-reaction with other common respiratory viruses or HAdV serotypes 1,4,5,6,31,55 and 57 was observed. The coefficients of variation (CV) of intra-assay and inter-assay were between 0.6% to 3.6%. Of 138 previously-defined HAdV-positive nasopharyngeal aspirates samples tested, the detection agreement between tq-PCR and nested PCR was 96.38% (133/138). The proposed tq-PCR assay is a sensitive, specific and reproducible method and has the potential for clinical use in the rapid and differential detection and quantitation of HAdV serotypes 2, 3 and 7.
Estimation of sensitivity, specificity and predictive values of two serologic tests for the detection of antibodies against Actinobacillus pleuropneumoniae serotype 2 in the absence of a reference test (gold standard)
Enøe, Claes; Andersen, Søren; Sørensen, Vibeke
Latent-class models were used to determine the sensitivity, specificity and predictive values of a polyclonal blocking enzyme-linked immunosorbent assay (ELISA) and a modified complement-fixation test (CFT) when there was no reference test. The tests were used for detection of antibodies against ...
Maciel, B M; Argôlo Filho, R C; Nogueira, S S C; Dias, J C T; Rezende, R P
Species of tegu (Tupinambis) are the largest lizards in South America. Large numbers of these lizards are hunted; there is a vigorous trade in their skins and the meat is consumed by rural and native peoples. The animals are also bred in captivity, an economic activity for rural populations which can help in the animals' conservation. Faecal samples from 30 captive-born tegus were analysed for the presence of Salmonella in two separate samplings. In the first analysis, samples from 26 animals (87%) yielded Salmonella enterica of which 23% were of Rubislaw serotype; 20% Carrau and Agona serotypes; 7% Infantis and Saint-Paul serotypes; 3% Panama and Brandenburg serotypes; 10% were S. enterica subsp. enterica and 7% were rough form. In the second analysis, four tegus (13%) which had been negative in the first sampling were positive, thus, 100% of the animals studied carried the bacterium. Antibiotic susceptibility showed resistance to sulfonamide in 82% of the isolates, streptomycin in 64%, tetracycline in 6% and Chloramphenicol in 20%. Two animals carried strains of the same serotype with different patterns of antibiotic susceptibility. Although it is well known that reptiles are a significant source of Salmonella, to our knowledge, its prevalence in tegu has not been studied previously.
Collazo, M. Thelma; Garza, John A.; Hayhurst, Andrew
Background There are currently 7 known serotypes of botulinum neurotoxin (BoNT) classified upon non-cross reactivity of neutralizing immunoglobulins. Non-neutralizing immunoglobulins, however, can exhibit cross-reactivities between 2 or more serotypes, particularly mosaic forms, which can hamper the development of highly specific immunoassays, especially if based on polyclonal antisera. Here we employ facile recombinant antibody technology to subtractively select ligands to each of the 7 BoNT serotypes, resulting in populations with very high specificity for their intended serotype. Methods and Findings A single llama was immunized with a cocktail of 7 BoNT toxoids to generate a phage display library of single domain antibodies (sdAb, VHH or nanobodies) which were selected on live toxins. Resulting sdAb were capable of detecting both toxin and toxin complex with the best combinations able to detect 100s-10s of pg per 50 µL sample in a liquid bead array. The most sensitive sdAb were combined in a heptaplex assay to identify each of the BoNT serotypes in buffer and milk and to a lesser extent in carrot juice, orange juice and cola. Several anti-A(1) sdAb recognized A2 complex, showing that subtype cross-reactivity within a serotype was evident. Many of our sdAb could act as both captor and tracer for several toxin and toxin complexes suggesting sdAb can be used as architectural probes to indicate BoNT oligomerisation. Six of 14 anti-A clones exhibited inhibition of SNAP-25 cleavage in the neuro-2A assay indicating some sdAb had toxin neutralizing capabilities. Many sdAb were also shown to be refoldable after exposure to high temperatures in contrast to polyclonal antisera, as monitored by circular dichroism. Conclusions Our panel of molecularly flexible antibodies should not only serve as a good starting point for ruggedizing assays and inhibitors, but enable the intricate architectures of BoNT toxins and complexes to be probed more extensively. PMID:20098614
Michele de Souza Bastos
Full Text Available INTRODUCTION: Manaus, the capital city of the state of Amazon with nearly 2 million inhabitants, is located in the middle of the Amazon rain forest and has suffered dengue outbreaks since 1998. METHODS: In this study, blood samples were investigated using reverse transcriptase-polymerase chain reaction (RT-PCR, aimed at identifying dengue virus serotypes. RESULTS: Acute phase sera from 432 patients were tested for the presence of dengue virus. Out of the 432 patients, 137 (31.3% were found to be positive. All the four dengue virus serotypes were observed. CONCLUSIONS: The simultaneous circulation of the four dengue serotypes is described for the first time in Manaus and in Brazil.
Dassanayake, Rohana P; Shanthalingam, Sudarvili; Herndon, Caroline N; Lawrence, Paulraj K; Frances Cassirer, E; Potter, Kathleen A; Foreyt, William J; Clinkenbeard, Kenneth D; Srikumaran, Subramaniam
Mannheimia haemolytica causes pneumonia in both bighorn sheep (BHS, Ovis canadensis) and domestic sheep (DS, Ovis aries). Under experimental conditions, co-pasturing of BHS and DS results in fatal pneumonia in BHS. It is conceivable that certain serotypes of M. haemolytica carried by DS are non-pathogenic to them, but lethal for BHS. M. haemolytica serotypes A1 and A2 are carried by DS in the nasopharynx. However, it is the serotype A2 that predominantly causes pneumonia in DS. The objectives of this study were to determine whether serotype A1 exhibits differential pathogenicity to BHS and DS, and to determine whether leukotoxin (Lkt) secreted by this organism is its primary virulence factor. Three groups each of BHS and DS were intra-tracheally administered either 1 x 10(9)cfu of serotype A1 wild-type (lktA-Wt group), Lkt-deletion mutant of serotype A1-(lktA-Mt group), or saline (control group), respectively. In the lktA-Wt groups, all four BHS died within 48h while none of the DS died during the 2-week study period. In the lktA-Mt groups, none of the BHS or DS died. In the control groups, one DS died due to an unrelated cause. Necropsy and histopathological findings revealed that death of BHS in the lktA-Wt group was due to bilateral, fibrinohemorrhagic pneumonia. Although the A1-Mt-inoculated BHS were clinically normal, on necropsy, lungs of two BHS showed varying degrees of mild chronic pneumonia. These results indicate that M. haemolytica serotype A1 is non-pathogenic to DS, but highly lethal to BHS, and that Lkt is the primary virulence factor of M. haemolytica.
Soto Garita, Claudio
An immunopotentiation trial has used sera from dengue seropositive patients from Costa Rica's endemic areas. The detection and semi-quantification of immunopotentiating antibodies were optimized against dengue virus serotype 1. The cell line K562 (human erythromyeloblastoid leukemia cells) has been more efficient than the U937 (human histiocytic lymphoma cells). A more adequate detection of immunopotentiating antibodies was determined. The optimal infection and virus-antibody incubation parameters are demonstrated for the detection of immunopotentiating antibodies with the immunostaining technique. The immuno-optimized assay has allowed the detection and semi-quantification of immunopotentiating antibodies against serotype 1 of dengue virus. Samples of strong positive, weak positive and dengue negative sera are analyzed. The end has been to evaluate the usefulness in the detection and semi-quantification of immunopotentiating antibodies. The presence of immunopotentiating antibodies was demonstrated against dengue virus serotype 1 in endemic zones of Costa Rica, to complement with the evaluation of the other existing serotypes is recommended [es
Harboe, Zitta B; Valentiner-Branth, Palle; Ingels, Helene
A seven-valent pneumococcal conjugate vaccine (PCV7) was introduced in the Danish childhood immunization program (2+1 schedule) in October 2007, followed by PCV13 starting from April 2010. The nationwide incidence of IPD among children younger than 5 years nearly halved after the introduction...... of children suspected to present with a vaccine failure. The period between April 19 and December 31, 2010 was considered a PCV7/PCV13 transitional period, where both vaccines were offered. We identified 45 episodes of IPD caused by a PCV7 serotype (23% of the total number) and 105 (55%) caused by one...... of the 6 additional serotypes in PCV13. Ten children had received at least one PCV7 dose before the onset of IPD caused by a PCV7 serotype. Seven children were considered to be incompletely vaccinated before IPD, but only three cases fulfilled the criteria of vaccine failure (caused by serotypes 14, 19F...
Kusiluka, L.J.M.; Ojeniyi, B.; Friis, N.F.
anti vaccine strains. The strong genomic homogeneity among, M. mycoides SC strains associated with outbreaks of contagious bovine pleuropneumonia in different regions of Tanzania suggests that the outbreaks of the disease in the 1990-99 period might have been caused Ly a single epidemic clone. Moreover......The genetic diversity of 60 field strains of Mycoplasma mycoides ssp. mycoides, small colony type (M,. mycoides), comprising 56 isolates from cattle in Tanzania, one from Kenya, two from Botswana and one from Portugal, as well as the type (PG1(T)) and vaccine (T-1-SR49) strains, was ivestigated...... strains. The AFLP profiles of the type and vaccine strains were indistingiuishable from each other. Indistinguishable AFLP profiles were found for 55 Tanzanian held strains, one of them isolated in 1990 and the other 54 isolated in 1998/1999), although one strain isolated in 1999 showed a different...
Thrane, Sandra Wingaard; Taylor, Véronique L.; Lund, Ole
aeruginosa serotyper (PAst) program, which enabled in silico serotyping of P. aeruginosa isolates using WGS data. PAst has been made publically available as a web-service, and aptly facilitate high-throughput serotyping analysis. The program overcomes critical issues such as the loss of in vitro typeability...... often associated with P. aeruginosa isolates from chronic infections, and quickly determines the serogroup of an isolate based on the sequence of the O-specific antigen (OSA) gene cluster. Here, PAst analysis of 1649 genomes resulted in successful serogroup assignments in 99.27% of the cases...
Le, Van Phan; Vu, Thi Thu Hang; Duong, Hong-Quan; Than, Van Thai; Song, Daesub
Foot-and-mouth disease virus (FMDV) is one of the highest risk factors that affects the animal industry of the country. The virus causes production loss and high ratio mortality in young cloven-hoofed animals in Vietnam. The VP1 coding gene of 80 FMDV samples (66 samples of the serotype O and 14 samples of the serotype A) collected from endemic outbreaks during 2006-2014 were analyzed to investigate their phylogeny and genetic relationship with other available FMDVs globally. Phylogenetic analysis indicated that the serotype O strains were clustered into two distinct viral topotypes (the SEA and ME-SA), while the serotype A strains were all clustered into the genotype IX. Among the study strains, the amino acid sequence identities were shared at a level of 90.1-100, 92.9-100, and 92.8-100% for the topotypes SEA, ME-SA, and genotype IX, respectively. Substitutions leading to changes in the amino acid sequence, which are critical for the VP1 antigenic sites were also identified. Our results showed that the studied strains are most closely related to the recent FMDV isolates from Southeast Asian countries (Myanmar, Thailand, Cambodia, Malaysia, and Laos), but are distinct from the earlier FMDV isolates within the genotypes. This study provides important evidence of recent movement of FMDVs serotype O and A into Vietnam within the last decade and their genetic accumulation to be closely related to strains causing FMD in surrounding countries.
To assess diversity of Salmonella enterica serotypes present in poultry and their environment from Southern Brazil, the Kauffman-White-LeMinor (KWL) scheme was used to serotype a total of 155 isolates. Isolates were then re-examined with nested PCR and sequencing of the dkgB-linked Intergenic Sequ...
Manchala Nageswar Reddy
Full Text Available Background Dengue is a global human public health threat, causing severe morbidity and mortality. The occurrence of sequential infection by more than one serotype of dengue virus (DENV is a major contributing factor for the induction of Dengue Hemorrhagic Fever (DHF and Dengue Shock Syndrome (DSS, two major medical conditions caused by DENV infection. However, there is no specific drug or vaccine available against dengue infection. There are reports indicating the increased incidence of concurrent infection of dengue in several tropical and subtropical regions. Recently, increasing number of DHF and DSS cases were reported in India indicating potential enhancement of concurrent DENV infections. Therefore, accurate determination of the occurrence of DENV serotype co-infections needs to be conducted in various DENV prone parts of India. In this context, the present study was conducted to analyse the magnitude of concurrent infection in northern Kerala, a southwest state of India, during three consecutive years from 2013 to 2015. Methods A total of 120 serum samples were collected from the suspected dengue patients. The serum samples were diagnosed for the presence of dengue NS1 antigen followed by the isolation of dengue genome from NS1 positive samples. The isolated dengue genome was further subjected to RTPCR based molecular serotyping. The phylogenetic tree was constructed based on the sequence of PCR amplified products. Results Out of the total number of samples collected, 100 samples were positive for dengue specific antigen (NS1 and 26 of them contained the dengue genome. The RTPCR based molecular serotyping of the dengue genome revealed the presence of all four serotypes with different combinations. However, serotypes 1 and 3 were predominant combinations of concurrent infection. Interestingly, there were two samples with all four serotypes concurrently infected in 2013. Discussion All samples containing dengue genome showed the presence of
Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping
Recent studies have shown that group B streptococcus (GBS) may be infectious across hosts. The purpose of this study is to investigate the pathogenicity of clinical GBS isolates with serotypes Ia, III and V from human and cow to tilapia and the evolutionary relationship among these GBS strains of different sources. A total of 27 clinical GBS isolates from human (n=10), cow (n=2) and tilapia (n=15) were analyzed using serotyping, multi-locus sequence typing (MLST) and pulsed-field gel electrophoresis (PFGE). Among them, 15 isolates were tested for their pathogenicity to tilapia. The results showed that five human GBS strains (2 serotype III, 2 serotype Ia and 1 serotype V) infected tilapia with mortality rate ranging from 56.67% to 100%, while the other five human GBS strains tested were unable to infect tilapia. In addition, two cow GBS strains C001 and C003 of serotype III infected tilapia. However, they had significantly lower pathogenicity than the five human strains. Furthermore, human GBS strains H005 and H008, which had very strong ability to infect tilapia, had the same PFGE pattern. MLST analysis showed that the five human and the two cow GBS strains that were able to infect tilapia belonged to clonal complexes CC19, CC23 and CC103. The study for the first time confirmed that human or cow GBS clonal complexes CC19, CC23 and CC103 containing strains with serotypes Ia, III and V could infect tilapia and induce clinical signs under experimental conditions. Copyright © 2015 Elsevier B.V. All rights reserved.
Cheng, Luisa W; Henderson, Thomas D
Botulinum neurotoxins (BoNTs) are among the most potent biological toxins for humans. Of the seven known serotypes (A-G) of BoNT, serotypes A, B and E cause most of the foodborne intoxications in humans. BoNTs in nature are associated with non-toxic accessory proteins known as neurotoxin-associated proteins (NAPs), forming large complexes that have been shown to play important roles in oral toxicity. Using mouse intraperitoneal and oral models of botulism, we determined the dose response to both BoNT/B holotoxin and complex toxins, and compared the toxicities of BoNT/B and BoNT/A complexes. Although serotype A and B complexes have similar NAP composition, BoNT/B formed larger-sized complexes, and was approximately 90 times more lethal in mouse oral intoxications than BoNT/A complexes. When normalized by mean lethal dose, mice orally treated with high doses of BoNT/B complex showed a delayed time-to-death when compared with mice treated with BoNT/A complex. Furthermore, we determined the effect of various food matrices on oral toxicity of BoNT/A and BoNT/B complexes. BoNT/B complexes showed lower oral bioavailability in liquid egg matrices when compared to BoNT/A complexes. In summary, our studies revealed several factors that can either enhance or reduce the toxicity and oral bioavailability of BoNTs. Dissecting the complexities of the different BoNT serotypes and their roles in foodborne botulism will lead to a better understanding of toxin biology and aid future food risk assessments. Published by Elsevier Ltd.
Nan Nwe Win
Full Text Available Determination of hepatitis C virus (HCV genotypes plays an important role in the direct-acting agent era. Discrepancies between HCV genotyping and serotyping assays are occasionally observed. Eighteen samples with discrepant results between genotyping and serotyping methods were analyzed. HCV serotyping and genotyping were based on the HCV nonstructural 4 (NS4 region and 5′-untranslated region (5′-UTR, respectively. HCV core and NS4 regions were chosen to be sequenced and were compared with the genotyping and serotyping results. Deep sequencing was also performed for the corresponding HCV NS4 regions. Seventeen out of 18 discrepant samples could be sequenced by the Sanger method. Both HCV core and NS4 sequences were concordant with that of genotyping in the 5′-UTR in all 17 samples. In cloning analysis of the HCV NS4 region, there were several amino acid variations, but each sequence was much closer to the peptide with the same genotype. Deep sequencing revealed that minor clones with different subgenotypes existed in two of the 17 samples. Genotyping by genome amplification showed high consistency, while several false reactions were detected by serotyping. The deep sequencing method also provides accurate genotyping results and may be useful for analyzing discrepant cases. HCV genotyping should be correctly determined before antiviral treatment.
Full Text Available Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs. The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs. Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents.
Full Text Available Shigella flexneri serotype 1b is among the most prominent serotypes in developing countries, followed by serotype 2a. However, only limited data is available on the global phenotypic and genotypic characteristics of S. flexneri 1b. In the present study, 40 S. flexneri 1b isolates from different regions of China were confirmed by serotyping and biochemical characterization. Antimicrobial susceptibility testing showed that 85% of these isolates were multidrug-resistant strains and antibiotic susceptibility profiles varied between geographical locations. Strains from Yunnan were far more resistant than those from Xinjiang, while only one strain from Shanghai was resistant to ceftazidime and aztreonam. Fifteen cephalosporin resistant isolates were identified in this study. ESBL genes (blaSHV, blaTEM, blaOXA, and blaCTX-M and ampC genes (blaMOX, blaFOX, blaMIR(ACT-1, blaDHA, blaCIT and blaACC were subsequently detected among the 15 isolates. The results showed that these strains were positive only for blaTEM, blaOXA, blaCTX-M, intI1, and intI2. Furthermore, pulsed-field gel electrophoresis (PFGE analysis showed that the 40 isolates formed different profiles, and the PFGE patterns of Xinjiang isolates were distinct from Yunnan and Shanghai isolates by one obvious, large, missing band. In summary, similarities in resistance patterns were observed in strains with the same PFGE pattern. Overall, the results supported the need for more prudent selection and use of antibiotics in China. We suggest that antibiotic susceptibility testing should be performed at the start of an outbreak, and antibiotic use should be restricted to severe Shigella cases, based on resistance pattern variations observed in different regions. The data obtained in the current study might help to develop a strategy for the treatment of infections caused by S. flexneri 1b in China.
Rasmussen, S. R.; Aarestrup, Frank Møller; Jensen, N. E.
A total of 122 Streptococcus suis serotype 2 strains were characterized thoroughly by comparing clinical and pathological observations, ribotype profiles, and antimicrobial resistance. Twenty-one different ribotype profiles were found and compared by cluster analysis, resulting in the identificat......A total of 122 Streptococcus suis serotype 2 strains were characterized thoroughly by comparing clinical and pathological observations, ribotype profiles, and antimicrobial resistance. Twenty-one different ribotype profiles were found and compared by cluster analysis, resulting...
Gil Ana I
Full Text Available Abstract Background Vibrio parahaemolyticus is a common cause of foodborne disease. Beginning in 1996, a more virulent strain having serotype O3:K6 caused major outbreaks in India and other parts of the world, resulting in the emergence of a pandemic. Other serovariants of this strain emerged during its dissemination and together with the original O3:K6 were termed strains of the pandemic clone. Two genomes, one of this virulent strain and one pre-pandemic strain have been sequenced. We sequenced four additional genomes of V. parahaemolyticus in this study that were isolated from different geographical regions and time points. Comparative genomic analyses of six strains of V. parahaemolyticus isolated from Asia and Peru were performed in order to advance knowledge concerning the evolution of V. parahaemolyticus; specifically, the genetic changes contributing to serotype conversion and virulence. Two pre-pandemic strains and three pandemic strains, isolated from different geographical regions, were serotype O3:K6 and either toxin profiles (tdh+, trh- or (tdh-, trh+. The sixth pandemic strain sequenced in this study was serotype O4:K68. Results Genomic analyses revealed that the trh+ and tdh+ strains had different types of pathogenicity islands and mobile elements as well as major structural differences between the tdh pathogenicity islands of the pre-pandemic and pandemic strains. In addition, the results of single nucleotide polymorphism (SNP analysis showed that 94% of the SNPs between O3:K6 and O4:K68 pandemic isolates were within a 141 kb region surrounding the O- and K-antigen-encoding gene clusters. The "core" genes of V. parahaemolyticus were also compared to those of V. cholerae and V. vulnificus, in order to delineate differences between these three pathogenic species. Approximately one-half (49-59% of each species' core genes were conserved in all three species, and 14-24% of the core genes were species-specific and in different
Eric S Donkor
Full Text Available Little is known about the population biology of Streptococcus pneumoniae in developing countries, although the majority of pneumococcal infections occur in this setting. The aim of the study was to apply MLST to investigate the population biology of S. pneumoniae in West Africa.Seventy three invasive and carriage S. pneumoniae isolates from three West African countries including The Gambia, Nigeria and Ghana were investigated. The isolates covered seven serotypes (1, 3, 5, 6A, 11, 14, 23F and were subjected to multilocus sequence typing and antibiotic susceptibility testing.Overall, 50 different sequence types (STs were identified, of which 38% (29 were novel. The most common ST was a novel clone-ST 4012 (6.5%, and some clones including STs 913, 925, 1737, 2160 and 3310 appeared to be specific to the study region. Two STs including ST 63 and ST 4012 were associated with multiple serotypes indicating a history of serotype switching. ST 63 was associated with serotypes 3 and 23F, while ST 4012 was associated with serotypes 6A and 23. eBURST analyses using the stringent 6/7 identical loci definition grouped the 50 STs into 5 clonal complexes and 65 singletons, expressing a high level of genetic diversity among the isolates. Compared to the other serotypes, serotypes 1 and 5 isolates appeared to be more clonal. Internationally recognized antibiotic resistant clones of S. pneumoniae were generally absent in the population investigated and the only multidrug resistant isolate identified (1/66 belong to the Pneumocococcal Epidemiology Network clone ST 63.The pneumococcal population in West Africa is quite divergent, and serotypes that are common in invasive disease (such as serotypes 1 and 5 are more likely to be clonal than serotypes that are common in carriage.
Wedderkopp, A.; Nielsen, E.M.; Pedersen, Karl
During the period January 1998-December 2001, all Danish broiler flocks were monitored bacteriologically for thermophilic campylobacters and isolates were stored at -80 degreesC. Six neighbouring broiler farms in a small community were selected for detailed examination of all Campylobacter jejuni...... isolated (n = 180) from these farms during 1998-2000 using Penner serotyping and pulsed-field gel electrophoresis (PFGE). The area and the farms were selected according to their prevalence of campylobacter so that both farms with low and high frequencies of campylobacter positive flocks were included...... in the study. The frequency of campylobacter positive flocks on the six farms ranged from 24.5 to 72.7%. One hundred and eighty of the isolates were C. jejuni (included in this study), 14 isolates were C. coli whereas 7 isolates belonged to other species but were not further identified. By serotyping of all C...
Tomich, Mladen; Fine, Daniel H.; Figurski, David H.
The tad locus of Actinobacillus actinomycetemcomitans encodes genes for the biogenesis of Flp pili, which allow the bacterium to adhere tenaciously to surfaces and form strong biofilms. Although tad (tight adherence) loci are widespread among bacterial and archaeal species, very little is known about the functions of the individual components of the Tad secretion apparatus. Here we characterize the mechanism by which the pre-Flp1 prepilin is processed to the mature pilus subunit. We demonstra...
Vagh A.A. and Jani R.G.
Full Text Available A study was carried out to find the different serotype of E.coli isolates from the young cattle and buffalo calves affected with calf scours. Different strains of E. coli were isolated from 30 cases of calf scour from both cattle and buffalo calves each. All the isolates of E. coli were typed for ‘O’ antigen. The relationship of serotypes of E. coli to each case showed that two of the twenty six serotypes were common and appeared most virulent in both the species. [Veterinary World 2010; 3(10.000: 458-459
Mwiine, Frank Norbert; Ayebazibwe, Chrisostom; Alexandersen, Søren
Foot-and-mouth disease (FMD) outbreaks in cattle occur annually in Uganda. In this study the authors investigated antibodies against FMD virus (FMDV) in cattle in surrounding areas of Lake Mburo National Park in South-western Uganda. Two hundred and eleven serum samples from 23 cattle herds were...... examined for the presence of antibodies against FMDV non-structural proteins and structural proteins using Ceditest® FMDV-NS and Ceditest® FMDV type O (Cedi Diagnostics BV, Lelystad, The Netherlands). Furthermore, serotype-specific antibodies against the seven serotypes of FMDV were determined using in......-house serotype-specific Solid Phase Blocking ELISAs (SPBE). Of the sera tested, 42.7% (90/211) were positive in the ELISA for antibodies against non-structural proteins, while 75.4% (159/211) had antibodies against the structural proteins of FMDV serotype O. Titres of ≥ 1:160 of serotype-specific antibodies...
Namatovu, Alice; Tjørnehøj, Kirsten; Belsham, Graham J.; Dhikusooka, Moses T.; Wekesa, Sabenzia N.; Muwanika, Vincent B.; Siegismund, Hans R.; Ayebazibwe, Chrisostom
To investigate the foot-and-mouth disease virus (FMDV) serotypes circulating in Uganda’s cattle population, both serological and virological analyses of samples from outbreaks that occurred during 2012–2013 were performed. Altogether, 79 sera and 60 oropharyngeal fluid (OP)/tissue/oral swab samples were collected from herds with reported FMD outbreaks in seven different Ugandan districts. Overall, 61/79 (77%) of the cattle sera were positive for antibodies against FMDV by PrioCHECK FMDV NS ELISA and solid phase blocking ELISA detected titres ≥ 80 for serotypes O, SAT 1, SAT 2 and SAT 3 in 41, 45, 30 and 45 of these 61 seropositive samples, respectively. Virus neutralisation tests detected the highest levels of neutralising antibodies (titres ≥ 45) against serotype O in the herds from Kween and Rakai districts, against SAT 1 in the herd from Nwoya district and against SAT 2 in the herds from Kiruhura, Isingiro and Ntungamo districts. The isolation of a SAT 2 FMDV from Isingiro was consistent with the detection of high levels of neutralising antibodies against SAT 2; sequencing (for the VP1 coding region) indicated that this virus belonged to lineage I within this serotype, like the currently used vaccine strain. From the Wakiso district 11 tissue/swab samples were collected; serotype A FMDV, genotype Africa (G-I), was isolated from the epithelial samples. This study shows that within a period of less than one year, FMD outbreaks in Uganda were caused by four different serotypes namely O, A, SAT 1 and SAT 2. Therefore, to enhance the control of FMD in Uganda, there is need for efficient and timely determination of outbreak virus strains/serotypes and vaccine matching. The value of incorporating serotype A antigen into the imported vaccines along with the current serotype O, SAT 1 and SAT 2 strains should be considered. PMID:25664876
Folster, Jason P; Campbell, Davina; Grass, Julian; Brown, Allison C; Bicknese, Amelia; Tolar, Beth; Joseph, Lavin A; Plumblee, Jodie R; Walker, Carrie; Fedorka-Cray, Paula J; Whichard, Jean M
Salmonella enterica is one of the most common causes of bacterial foodborne illness in the United States. Although most Salmonella infections are self-limiting, antimicrobial treatment of invasive salmonellosis is critical. The primary antimicrobial treatment options include fluoroquinolones or extended-spectrum cephalosporins, and resistance to these antimicrobial drugs may complicate treatment. At present, S. enterica is composed of more than 2,600 unique serotypes, which vary greatly in geographic prevalence, ecological niche, and the ability to cause human disease, and it is important to understand and mitigate the source of human infection, particularly when antimicrobial resistance is found. In this study, we identified and characterized 19 S. enterica serotype Albert isolates collected from food animals, retail meat, and humans in the United States during 2005 to 2013. All five isolates from nonhuman sources were obtained from turkeys or ground turkey, and epidemiologic data suggest poultry consumption or live-poultry exposure as the probable source of infection. S. enterica serotype Albert also appears to be geographically localized to the midwestern United States. All 19 isolates displayed multidrug resistance, including decreased susceptibility to fluoroquinolones and resistance to extended-spectrum cephalosporins. Turkeys are a likely source of multidrug-resistant S. enterica serotype Albert, and circulation of resistance plasmids, as opposed to the expansion of a single resistant strain, is playing a role. More work is needed to understand why these resistance plasmids spread and how their presence and the serotype they reside in contribute to human disease. Copyright © 2015, American Society for Microbiology. All Rights Reserved.
Wongsawan, Kanruethai; Gottschalk, Marcelo; Tharavichitkul, Prasit
In this present study, the serotype of 40 Streptococcus suis isolates from submaxillary glands of pig carcasses sold in wet markets in Chiang Mai Province, northern Thailand, was investigated. Eleven serotypes, including types 2, 3, 4, 5, 7, 8, 9, 17, 21, 22 and 31, were found in the isolates by a Multiplex PCR combined with serum agglutination. Of the eleven serotypes present, type 3 was the most prevalent, while types 2, 4, 5 and 21 were of primary interest due to their human isolate serotype. The mrp+/epf - /sly - genotype was found to be the most prevalent genotype. This study indicates the importance of effective control of human S. suis infection due to raw pork or pig carcass handling in northern Thailand.
Bøtner, Anette; Oura, Chris; Saegerman, Claude
established by the Animal Health and Welfare Panel. Currently, three special features can be assigned to BTV-8, which are the ability to cause serious disease in cattle and goats, the ability to be transmitted transplacentally, and the ability to contaminate semen. The transplacental transmission......To answer a question from the European Commission on the potential special characteristics of bluetongue virus (BTV) serotype 8 (BTV-8) compared to other serotypes and their possible impact on the epidemiology of the disease, a systematic literature review was carried out by a working group...... and the contamination of semen are also observed for several serotypes of modified live virus (MLV) vaccines and for some cell culture/egg passaged strains. These two features may have an impact on the epidemiology of the disease, since they may increase the ability of BTV-8 to survive the winter period, for example...
Perez-Casal, Jose; Prysliak, Tracy; Maina, Teresa; Wang, Yejun; Townsend, Hugh; Berverov, Emil; Nkando, Isabel; Wesonga, Hezron; Liljander, Anne; Jores, Joerg; Naessens, Jan; Gerdts, Volker; Potter, Andrew
Current contagious bovine pleuropneumonia (CBPP) vaccines are based on live-attenuated strains of Mycoplasma mycoides subsp. mycoides (Mmm). These vaccines have shortcomings in terms of efficacy, duration of immunity and in some cases show severe side effects at the inoculation site; hence the need to develop new vaccines to combat the disease. Reverse vaccinology approaches were used and identified 66 candidate Mycoplasma proteins using available Mmm genome data. These proteins were ranked by their ability to be recognized by serum from CBPP-positive cattle and thereafter used to inoculate naïve cattle. We report here the inoculation of cattle with recombinant proteins and the subsequent humoral and T-cell-mediated immune responses to these proteins and conclude that a subset of these proteins are candidate molecules for recombinant protein-based subunit vaccines for CBPP control. Copyright © 2015 Elsevier B.V. All rights reserved.
Gupta, Birendra Prasad; Singh, Sneha; Kurmi, Roshan; Malla, Rajani; Sreekumar, Easwaran; Manandhar, Krishna Das
Background & objectives: Epidemiological interventions and mosquito control are the available measures for dengue control. The former approach uses serotype and genetic information on the circulating virus strains. Dengue has been frequently reported from Nepal, but this information is mostly lacking. The present study was done to generate a comprehensive clinical and virological picture of a dengue outbreak in Nepal during 2013. Methods: A hospital-based study involving patients from five districts of Nepal was carried out. Demographic information, clinical details and dengue serological status were obtained. Viral RNA was characterized at the molecular level by reverse-transcription polymerase chain reaction (RT-PCR), nucleotide sequencing and phylogenetic analysis. Results: From among the 2340 laboratory-confirmed dengue cases during the study period, 198 patients consented for the study. Clinically they had fever (100%), headache (59.1%), rashes (18.2%), retro-orbital pain (30.3%), vomiting (15.1%), joint pain (28.8%) and thrombocytopenia (74.3%). Fifteen (7.5%) of them had mucosal bleeding manifestations, and the rest were uncomplicated dengue fever. The patients were mostly adults with a mean age of 45.75 ± 38.61 yr. Of the 52 acute serum samples tested, 15 were positive in RT-PCR. The causative virus was identified as DENV serotype 2 belonging to the Cosmopolitan genotype. Interpretations & conclusions: We report here the involvement of DENV serotype 2 in an outbreak in Nepal in 2013. Earlier outbreaks in the region in 2010 were attributed to serotype 1 virus. As serotype shifts are frequently associated with secondary infections and severe disease, there is a need for enhancing surveillance especially in the monsoon and post-monsoon periods to prevent large-scale, severe dengue outbreaks in the region. PMID:26905233
Coinfection by Ureaplasma spp., Photobacterium damselae and an Actinomyces-like microorganism in a bottlenose dolphin (Tursiops truncatus) with pleuropneumonia stranded along the Adriatic coast of Italy.
Di Francesco, Gabriella; Cammà, Cesare; Curini, Valentina; Mazzariol, Sandro; Proietto, Umberto; Di Francesco, Cristina Esmeralda; Ferri, Nicola; Di Provvido, Andrea; Di Guardo, Giovanni
A case of pleuropneumonia is reported in an adult male bottlenose dolphin (Tursiops truncatus) found stranded in 2014 along the Central Adriatic coast of Italy. A severe pyogranulomatous pneumonia and thoracic lymphadenopathy were present at necropsy. Numerous Splendore-Hoeppli bodies were found microscopically scattered throughout the lung. Histochemical evidence of Actinomyces-like organisms was obtained from the pulmonary parenchyma, with a strain of Photobacterium damselae subsp. piscicida and Ureaplasma spp. being also isolated from the same tissue. For the latter, a genome fragment of approximately 1400 bp from the 16s rDNA was amplified and sequenced. BLAST analysis revealed 100% identity with an uncultured Ureaplasma spp. (JQ193826.1). Copyright © 2016 Elsevier Ltd. All rights reserved.
Full Text Available Haemophilus parasuis can be either a commensal bacterium of the porcine respiratory tract or an opportunistic pathogen causing Glässer's disease, a severe systemic disease that has led to significant economical losses in the pig industry worldwide. We determined the complete genomic sequence of H. parasuis SH0165, a highly virulent strain of serovar 5, which was isolated from a hog pen in North China. The single circular chromosome was 2,269,156 base pairs in length and contained 2,031 protein-coding genes. Together with the full spectrum of genes detected by the analysis of metabolic pathways, we confirmed that H. parasuis generates ATP via both fermentation and respiration, and possesses an intact TCA cycle for anabolism. In addition to possessing the complete pathway essential for the biosynthesis of heme, this pathogen was also found to be well-equipped with different iron acquisition systems, such as the TonB system and ABC-type transport complexes, to overcome iron limitation during infection and persistence. We identified a number of genes encoding potential virulence factors, such as type IV fimbriae and surface polysaccharides. Analysis of the genome confirmed that H. parasuis is naturally competent, as genes related to DNA uptake are present. A nine-mer DNA uptake signal sequence (ACAAGCGGT, identical to that found in Actinobacillus pleuropneumoniae and Mannheimia haemolytica, followed by similar downstream motifs, was identified in the SH0165 genome. Genomic and phylogenetic comparisons with other Pasteurellaceae species further indicated that H. parasuis was closely related to another swine pathogenic bacteria A. pleuropneumoniae. The comprehensive genetic analysis presented here provides a foundation for future research on the metabolism, natural competence and virulence of H. parasuis.
Full Text Available Salmonella is frequently found in poultry and represent an important source for human gastrointestinal infections worldwide. The aim of this study was to investigate the prevalence, genotypes and antimicrobial resistance of Salmonella serotypes in broilers from Ecuador. Caeca content from 388 at random selected broiler batches were collected in 6 slaughterhouses during 1 year and analyzed by the ISO 6579/Amd1 protocol for the isolation for Salmonella. Isolates were serotyped and genotypic variation was acceded by pulsed field gel electrophoresis. MIC values for sulfamethoxazole, gentamicin, ciprofloxacin, ampicillin, cefotaxime, ceftazidime, tetracycline, streptomycin, trimethropim, chloramphenicol, colistin, florfenicol, kanamycin and nalidixic acid were obtained. Presence of blaCTX-M, blaTEM, blaSHV and blaCMY; and mcr-1 plasmid genes was investigated in resistant strains to cefotaxime and colistin respectively. Prevalence at batch level was 16.0%. The most common serotype was S. Infantis (83.9% followed by S. Enteritidis (14.5% and S. Corvallis (1.6%. The pulsed field gel electrophoresis analysis showed that S. Corvallis, S. Enteritidis and S. Infantis isolates belonged to 1, 2 and 12 genotypes respectively. S. Infantis isolates showed high resistance rates to 12 antibiotics ranging from 57.7% (kanamycin up to 98.1% (nalidixic acid and sulfamethoxazole. All S. Enteritidis isolates showed resistance to colistin. High multiresistant patterns were found for all the serotypes. The blaCTX-M gene was present in 33 S. Infantis isolates while mcr-1 was negative in 10 colistin resistant isolates. This study provides the first set of scientific data on prevalence and multidrug-resistant Salmonella coming from commercial poultry in Ecuador.
Full Text Available Despite the public health importance of Salmonella infection in pigs, little is known about the associated dynamics of fecal shedding and immunity. In this study, we investigated the transitions of pigs through the states of Salmonella fecal shedding and immune response post-Salmonella inoculation as affected by the challenge dose and serotype. Continuous-time multistate Markov models were developed using published experimental data. The model for shedding had four transient states, of which two were shedding (continuous and intermittent shedding and two non-shedding (latency and intermittent non-shedding, and one absorbing state representing permanent cessation of shedding. The immune response model had two transient states representing responses below and above the seroconversion level. The effects of two doses [low (0.65×10(6 CFU/pig and high (0.65×10(9 CFU/pig] and four serotypes (Salmonella Yoruba, Salmonella Cubana, Salmonella Typhimurium, and Salmonella Derby on the models' transition intensities were evaluated using a proportional intensities model. Results indicated statistically significant effects of the challenge dose and serotype on the dynamics of shedding and immune response. The time spent in the specific states was also estimated. Continuous shedding was on average 10-26 days longer, while intermittent non-shedding was 2-4 days shorter, in pigs challenged with the high compared to low dose. Interestingly, among pigs challenged with the high dose, the continuous and intermittent shedding states were on average up to 10-17 and 3-4 days longer, respectively, in pigs infected with S. Cubana compared to the other three serotypes. Pigs challenged with the high dose of S. Typhimurium or S. Derby seroconverted on average up to 8-11 days faster compared to the low dose. These findings highlight that Salmonella fecal shedding and immune response following Salmonella challenge are dose- and serotype-dependent and that the detection of
Horsington, Jacquelyn; Hartley, Carol A; Gilkerson, James R
Respiratory infections are a major burden in the performance horse industry. Equine rhinitis B virus (ERBV) has been isolated from horses displaying clinical respiratory disease, and ERBV-neutralizing antibodies have been detected in 50-80% of horses in reported surveys. Current ERBV isolation and detection methods may underestimate the number of ERBV-positive animals and do not identify multiple serotype infections. The aim of the current study was to develop a serotyping ERBV antibody-detection enzyme-linked immunosorbent assay (ELISA) and examine the seroprevalence of ERBV in a group of Australian weanling horses. ELISAs with high sensitivity and specificity were developed. The seroprevalence of ERBV in the weanling horses was high (74-86%); ERBV-3 antibodies were most prevalent (58-62%) and ERBV-2 antibodies were least prevalent (10-16%). Many horses were seropositive to 2 or more serotypes. All 3 serotypes of ERBV were detected, and concurrent positivity to multiple serotypes was common.
Kiely, R A
The screening of 2000 women of childbearing age in Cork between 2004 and 2006 produced 37 erythromycin-resistant group B streptococcus (GBS) isolates. PCR analysis was performed to determine the basis for erythromycin resistance. The ermTR gene was most frequently expressed (n = 19), followed by the ermB gene (n = 8). Four isolates harboured the mefA gene. Six isolates yielded no PCR products. Some phenotype-genotype correlation was observed. All isolates expressing the mefA gene displayed the M phenotype whilst all those expressing ermB displayed the constitutive macrolide resistance (cMLS(B)) phenotype. Of 19 isolates that expressed the ermTR gene, 16 displayed the inducible macrolide resistance (iMLS(B)) phenotype. Serotype analysis revealed that serotypes III and V predominated in these isolates. The identification of two erythromycin-resistant serotype VIII isolates among this collection represents the first reported finding of erythromycin resistance in this serotype. A single isolate was non-typable using two latex agglutination serotyping kits.
Zhu, Lixian; Feng, Xiaohui; Zhang, Lihua; Zhu, Ruiliang; Luo, Xin
The aim of this work was to study the epidemiology of Listeria spp., particularly Listeria monocytogenes, and to identify the serotypes present in contaminated samples from beef processing plants in China. A total of 439 samples were obtained from bovine feces, hides, and carcasses at three commercial processing plants. A standard protocol (ISO 11290-1) was followed to detect Listeria spp. and L. monocytogenes, and multiplex polymerase chain reaction was used to identify the various L. monocytogenes serotypes. The overall prevalences of Listeria spp. and L. monocytogenes were 65.6% and 26.4%, respectively, and the contamination was highest in the hide samples. The identified L. monocytogenes serotypes were 1/2c and 1/2a. The results of the current study indicate that Listeria spp. contamination is common in Chinese beef processing plants; specific measures should be taken to prevent and/or treat L. monocytogenes contamination of feces and hides in beef slaughter plants. Furthermore, because Listeria spp. contamination was found to be prevalent, it should, therefore, be studied further. The prevention of cases of sporadic listeriosis in China should also be addressed.
Gerna, G; Forster, J; Parea, M; Sarasini, A; Di Matteo, A; Baldanti, F; Langosch, B; Schmidt, S; Battaglia, M
A nosocomial outbreak of rotavirus gastroenteritis involving 52 newborns occurred between June and September 1988 at the University Children's Hospital of Freiburg, Federal Republic of Germany. Stools from 27 representative patients were examined for rotavirus serotypes, using a monoclonal antibody-based enzyme-linked immunosorbent assay. The electropherotype was also examined by polyacrylamide gel electrophoresis of genomic RNA. As many as 18 patients were found to be infected by serotype 4, subtype 4B strain, and in all of them the same electropherotype was detected. Although rotavirus from the remaining nine patients could not be typed, the electropherotype in four was identical to that of the serotype 4, subtype 4B strain. Thus, most of the patients in the outbreak were infected by the same rotavirus strain. Retrospective epidemiological studies showed that the 4B strain began to circulate at the hospital in January 1988, whereas only rotavirus serotypes 1, 3, and 4A were detected in 1985-1987. The primary case of the outbreak was presumably a newborn with acute gastroenteritis, admitted to the hospital from a small maternity unit in the same urban area. During the outbreak, 12 of 44 healthy newborns in the nurseries of the Children's Hospital and other maternity hospitals were found to be asymptomatic rotavirus carriers, and in three of the newborns the same 4B strain was detected. This is the first reported outbreak caused by a serotype 4, subtype 4B strain.
Full Text Available Dengue virus (DENV infection is a major emerging disease widely distributed throughout the tropical and subtropical regions of the world affecting several millions of people. Despite constants efforts, no specific treatment or effective vaccine is yet available. Here we show a novel design of a DNA immunisation strategy that resulted in the induction of strong antibody responses with high neutralisation titres in mice against all four viral serotypes. The immunogenic molecule is an engineered version of the domain III (DIII of the virus E protein fused to the dimerising CH3 domain of the IgG immunoglobulin H chain. The DIII sequences were also codon-optimised for expression in mammalian cells. While DIII alone is very poorly secreted, the codon-optimised fusion protein is rightly expressed, folded and secreted at high levels, thus inducing strong antibody responses. Mice were immunised using gene-gun technology, an efficient way of intradermal delivery of the plasmid DNA, and the vaccine was able to induce neutralising titres against all serotypes. Additionally, all sera showed reactivity to a recombinant DIII version and the recombinant E protein produced and secreted from mammalian cells in a mono-biotinylated form when tested in a conformational ELISA. Sera were also highly reactive to infective viral particles in a virus-capture ELISA and specific for each serotype as revealed by the low cross-reactive and cross-neutralising activities. The serotype specific sera did not induce antibody dependent enhancement of infection (ADE in non-homologous virus serotypes. A tetravalent immunisation protocol in mice showed induction of neutralising antibodies against all four dengue serotypes as well.
Vaddadi, K; Gandikota, C; Jain, P K; Prasad, V S V; Venkataramana, M
The burden of dengue virus infections increased globally during recent years. Though India is considered as dengue hyper-endemic country, limited data are available on disease epidemiology. The present study includes molecular characterization of dengue virus strains occurred in Hyderabad, India, during the year 2014. A total of 120 febrile cases were recruited for this study, which includes only children and 41 were serologically confirmed for dengue positive infections using non-structural (NS1) and/or IgG/IgM ELISA tests. RT-PCR, nucleotide sequencing and evolutionary analyses were carried out to identify the circulating serotypes/genotypes. The data indicated a high percent of severe dengue (63%) in primary infections. Simultaneous circulation of all four serotypes and co-infections were observed for the first time in Hyderabad, India. In total, 15 patients were co-infected with more than one dengue serotype and 12 (80%) of them had severe dengue. One of the striking findings of the present study is the identification of serotype Den-1 as the first report from this region and this strain showed close relatedness to the Thailand 1980 strains but not to any of the strains reported from India until now. Phylogenetically, all four strains of the present study showed close relatedness to the strains, which are reported to be high virulent.
E de Sousa
Full Text Available In order to maintain the high production and export rates achieved by the Brazilian poultry industry, it is necessary to prevent and control certain disease agents, such as Salmonella spp. Using bacterial cultures, the aim of the present study was to investigate the prevalence of Salmonella spp. in specimens collected from broiler facilities. Local wild birds were also sampled, as well as the feces of swine housed on the poultry farm. After sample collection, the isolated serotypes were subsequently inoculated into broiler chicks to determine their effects. Positive samples were collected from the following locations in the poultry facilities: poultry litter (S. serotype 4,5,12:R:-; S. Heidelberg; S. Infantis, broiler feces (S. Heidelberg; S. serotype 6,7:R:-; S. serotype 4,5,12:R:-; S. Tennessee, water (S. Glostrup; S. serotype 6,8:d:-;, and lesser mealworms (Alphitobius diaperinus found in the litter (S. Tennessee. Among the 36 wild birds captured, S. Heidelberg was isolated from one bird's organs and intestinal contents (Colaptes campestris, and S. Enteritidis was isolated from another bird's intestinal contents (Zenaida auriculata. Salmonella Panama and Salmonella Typhimurium were isolated from swine feces. One-day-old chicks (150 were divided into 10 groups of 15 animals each. Each group was orally inoculated with a previously isolated serotype of Salmonella. Soft stools were observed on the cage floor and around the birds' cloaca between 3 and 12 days post-infection (dpi. The different serotypes of Salmonella used to inoculate the chicks were re-isolated from the spleen, liver, and cecal content samples of the infected birds on 15 and 21 dpi.
González Martínez, F; Navarro Gómez, M L; Saavedra Lozano, J; Santos Sebastián, M M; Rodríguez Fernández, R; González Sanchéz, M; Cercenado Mansilla, E; Hernández-Sampelayo Matos, T
There has been an increased incidence in invasive pneumococcal disease (IPD) produced by non-vaccine serotype (NVS) of Streptococcus pneumoniae after the introduction of PCV7. Our objective was to describe the epidemiological, clinical and microbiological characteristics of IPD caused by NVS in a tertiary hospital in Madrid. Retrospective (1998-2004) and prospective (2005-2009) study evaluating IPD caused by NVS in children. The study was divided into three periods: P1 (1998-2001) when PCV7 was not commercialized; P2 (2002-2005) with 40% vaccine coverage among children; and P3 (2006-2009) when the vaccine was added to the Childhood Immunization Schedule in Madrid. We analyzed 155 cases of IPD. One hundred and fifty of these isolates were serotyped (100 were NVS). There was an increase in the prevalence of IPD from P1 (31%) to P2 (54%) and P3 (91%). The most relevant emerging serotypes were 19A, 7F, 1, 5, 3 and 15C. The most significant clinical syndromes produced by some specific serotypes were as follows: lower respiratory tract infection (LRTI) by serotypes 1, 3, 5 and 15C; LRTI, primary bacteremia and meningitis by serotype 19A; and primary bacteremia by serotype 7F (66%). The large majority (83.8%) of NVS were sensitive to penicillin. There has been an increased prevalence of IPD caused by NVS since the introduction of PCV7. These changes should prompt the introduction of new pneumococcal vaccines, which include most of the NVS, in the childhood immunization calendar to prevent IPD in children. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Balinda Sheila N
Full Text Available Abstract Background Foot-and-mouth disease (FMD is endemic in East Africa with the majority of the reported outbreaks attributed to serotype O virus. In this study, phylogenetic analyses of the polyprotein coding region of serotype O FMD viruses from Kenya and Uganda has been undertaken to infer evolutionary relationships and processes responsible for the generation and maintenance of diversity within this serotype. FMD virus RNA was obtained from six samples following virus isolation in cell culture and in one case by direct extraction from an oropharyngeal sample. Following RT-PCR, the single long open reading frame, encoding the polyprotein, was sequenced. Results Phylogenetic comparisons of the VP1 coding region showed that the recent East African viruses belong to one lineage within the EA-2 topotype while an older Kenyan strain, K/52/1992 is a representative of the topotype EA-1. Evolutionary relationships between the coding regions for the leader protease (L, the capsid region and almost the entire coding region are monophyletic except for the K/52/1992 which is distinct. Furthermore, phylogenetic relationships for the P2 and P3 regions suggest that the K/52/1992 is a probable recombinant between serotypes A and O. A bootscan analysis of K/52/1992 with East African FMD serotype A viruses (A21/KEN/1964 and A23/KEN/1965 and serotype O viral isolate (K/117/1999 revealed that the P2 region is probably derived from a serotype A strain while the P3 region appears to be a mosaic derived from both serotypes A and O. Conclusions Sequences of the VP1 coding region from recent serotype O FMDVs from Kenya and Uganda are all representatives of a specific East African lineage (topotype EA-2, a probable indication that hardly any FMD introductions of this serotype have occurred from outside the region in the recent past. Furthermore, evidence for interserotypic recombination, within the non-structural protein coding regions, between FMDVs of serotypes A
Joensen, Katrine Grimstrup; Tetzschner, Anna M. M.; Iguchi, Atsushi
typing and surveillance. The aim of this study was to establish a valid and publicly available tool for WGS-based in silico serotyping of E. coli applicable for routine typing and surveillance. A FASTA database of specific O-antigen processing system genes for O typing and flagellin genes for H typing...... tool. SerotypeFinder was evaluated on 682 E. coli genomes, 108 of which were sequenced for this study, where both the whole genome and the serotype were available. In total, 601 and 509 isolates were included for O and H typing, respectively. The O-antigen genes wzx, wzy, wzm, and wzt and the flagellin...
Ali, Amjad; Ahmad, Habib; Idrees, Muhammad; Zahir, Fazli; Ali, Ijaz
Dengue virus is circulating in Pakistan since 1994, which causes major and minor outbreaks in many areas of the country. The incidence of dengue in Pakistan in past years mainly restricted to parts of Sindh and Punjab provinces. As such, a severe dengue outbreak appeared in Pakistan in 2011, particularly in Punjab province with Lahore as the most hit city (290 deaths). In 2013, for the first time in the history of Pakistan, dengue outbreak erupted in Swat District, Khyber Pakhtunkhwa, which claimed more than 57 lives. Hence this study was conducted to document circulating serotypes of dengue virus in Pakistan in 2011 and 2013 dengue outbreaks in two different territories/areas of the country. In total, 1340 blood samples from people having dengue (ELISA positive) and/or dengue like symptoms from various cities/areas of Punjab and Swat, Khyber Pakhtunkhwa (KP) were collected and analyzed by reverse transcription polymerase chain reaction (RT-PCR) using serotype specific primers. The results indicated that all the four dengue virus serotypes were circulating in Punjab Province with highest frequency of DENV-2 (41.64 %) and DENV-3 (41.05 %). Similarly, DENV-2 (41.66 %) and DENV-3 (35.0 %) were dominant serotypes detected in KP-based people lived in Punjab. On the other hand only DENV-2 (40.0 %) and DENV-3 (60.0 %) were detected in Swat District. Furthermore an important observation noted in this study was mixed infection of DENV-2 and DENV-3 in Punjab in 2011 (3.81 %) and in people from KP infected in Punjab (8.33 %) which may account for the high mortality and morbidity rates as compared to previous outbreaks. Over all male population was mostly infected as compared to females and people in the age group between 15 to 45 was the highest infected group. The findings of this study indicate that all four serotypes of dengue virus are circulating in Punjab whereas serotypes 2 and 3 introduced for the first time into Swat, KP in 2013; about 600 km away from Lahore
Balinda, Sheila; Siegismund, Hans; Muwanika, Vincent
from both serotypes A and O. Conclusions Sequences of the VP1 coding region from recent serotype O FMDVs from Kenya and Uganda are all representatives of a specific East African lineage (topotype EA-2), a probable indication that hardly any FMD introductions of this serotype have occurred from outside...... the region in the recent past. Furthermore, evidence for interserotypic recombination, within the non-structural protein coding regions, between FMDVs of serotypes A and O has been obtained. In addition to characterization using the VP1 coding region, analyses involving the non-structural protein coding...
Eight (4%) of the children had no detectable antibody, 178 (89%), 180 (90%) and 181 (90.5%) were positive for antibodies to poliovirus types 1, 2 and 3, respectively. Overall, 162 (81%) of the children had antibodies to the three poliovirus serotypes at a titre of at least 1:8. The study shows the need for proper monitoring of ...
Ying Xiu eToh
Full Text Available Dengue virus has four serotypes and is endemic globally in tropical countries. Neither a specific treatment nor an approved vaccine is available, and correlates of protection are not established. The standard neutralization assay cannot differentiate between serotype-specific and serotype cross-reactive antibodies in patients early after infection, leading to an overestimation of the long-term serotype-specific protection of an antibody response. It is known that the cross-reactive response in patients is temporary but few studies have assessed kinetics and potential changes in serum antibody specificity over time. To better define the specificity of polyclonal antibodies during disease and after recovery, longitudinal samples from patients with primary or secondary DENV-2 infection were collected over a period of one year. We found that serotype cross-reactive antibodies peaked three weeks after infection and subsided within one year. Since secondary patients rapidly produced antibodies specific for the virus envelope (E protein, an E-specific ELISA was superior compared to a virus particle-specific ELISA to identify patients with secondary infections. Dengue infection triggered a massive activation and mobilization of both naïve and memory B cells possibly from lymphoid organs into the blood, providing an explanation for the surge of circulating plasmablasts and the increase in cross-reactive E protein-specific antibodies.
Yeh, Jih-Ching; Lo, Dan-Yuan; Chang, Shao-Kuang; Chou, Chi-Chung; Kuo, Hung-Chih
Pasteurella multocida (PM) can cause progressive atrophic rhinitis and suppurative bronchopneumonia in pigs. The present study performed antimicrobial susceptibility testing and serotype and genotype identification on the 62 PM strains isolated from the lungs of diseased pigs with respiratory symptoms. Antimicrobial susceptibility testing examined 13 antimicrobial agents (amoxicillin, cefazolin, doxycycline, flumequine, enrofloxacin, florfenicol, kanamycin, lincomycin, Linco-Spectin (lincomycin and spectinomycin), erythromycin, tylosin, tilmicosin and tiamulin). Antimicrobial resistance ratios were over 40% in all of the antimicrobial agents except for cefazolin. The highest levels of resistance (100%) were found for kanamycin, erythromycin and tylosin. The majority of isolated strains was serotype D:L6 (n=35) followed by A:L3 (n=17). Comparison of the antimicrobial resistance levels between the two serotypes showed that the antimicrobial resistance rates were higher in D:L6 than in A:L3 for all the tested antimicrobials except for tylosin and tilmicosin. For PM with erm (B), erm (T) or erm (42), the results showed no significant difference compared with non-resistance gene strains in phenotype. Pulsed-field gel electrophoresis genotyping using Apa I restriction digestion of the genomic DNA demonstrated that there were 17 distinct clusters with a similarity of 85% or more, and the genotyping result was similar to that of serotyping. The results of the present study demonstrated that the PM isolated from diseased pigs in Taiwan was resistant to multiple antimicrobials, and the distribution of antimicrobial resistance was associated with pulsotype and serotype. © British Veterinary Association (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Seoud, Muheiddine; Nassar, Anwar H; Zalloua, Pierre; Boghossian, Nansi; Ezeddine, Jihad; Fakhoury, Hassan; Abboud, Joseph; Melki, Imad; Araj, George; Nacouzi, Ghinwa; Sanyoura, May; Yunis, Khalid
The study aimed at determining the prevalence, risk factors, perinatal transmission, and serotypes of Group B Streptococcus (GBS) among pregnant women and their newborns in Beirut, Lebanon. This was a cross-sectional study of all pregnant women admitted from February to September 2006 to three major hospitals. Overall, 137 of 775 (17.7%) mothers and 50 of 682 newborns (7.3%) tested positive for GBS. Maternal colonization was not associated with maternal age, household income, gravidity, intrapartum fever, preterm labor, or premature rupture of membrane. Transmission rate was 40/120 (30%). Serotype 5 (24.1%) was the most common followed by serotype 1a (15.0%), 3 (14.4%), 2 (11.8%) and 1b (7.5%). Pregnant women in Lebanon appear to have a relatively high prevalence of GBS colonization with no identifiable risk factors for its acquisition. These results could provide basis for the institution of a national policy for universal maternal GBS screening to reduce neonatal morbidity and mortality.
Yoshioka, Cristina R M; Martinez, Marina B; Brandileone, Maria C C; Ragazzi, Selma B; Guerra, Maria L L S; Santos, Silvia R; Shieh, Huei H; Gilio, Alfredo E
To identify the most common pneumococcal serotypes in children hospitalized with invasive pneumonia, correlate isolated serotypes with those included in conjugate vaccines, and ascertain the sensitivity of the isolated pneumococcal strains to penicillin and other antibiotics. From January 2003 to October 2008, a retrospective study of hospitalized children with a diagnosis of Streptococcus pneumoniae pneumonia was conducted at the university hospital of Universidade de São Paulo. Criteria for inclusion were: age greater than 29 days and less than 15 years, radiological and clinical diagnosis of pneumonia, and isolation of Streptococcus pneumoniae in blood cultures and/or pleural effusion. The study included 107 children. The most common serotypes were 14 (36.5%), 1 (16%), 5 (14.6%), 6B (6.3%) and 3 (4.2%). The proportion of identified serotypes contained in the heptavalent, 10-valent and 13-valent conjugate vaccines was 53.1, 86.5, and 96.9%, respectively. Pneumococcal strains were sensitive to penicillin (minimum inhibitory concentration, MIC ≤ 2 µg/mL) in 100 cases (93.5%) and displayed intermediate resistance (MIC = 4 µg/mL) in 7 cases (6.5%). No strains were penicillin-resistant (MIC ≥ 8 µg/mL) according to the Clinical and Laboratory Standards Institute 2008 standards. Tested isolates were highly sensitive to vancomycin, rifampicin, ceftriaxone, clindamycin, erythromycin, and chloramphenicol. Our results confirm a significant potential impact of conjugate vaccines, mainly 10-valent and 13-valent, on invasive pneumonia. Furthermore, susceptibility testing results show that penicillin is still the treatment of choice for invasive pneumonia in our setting.
Bachanek-Bankowska, Katarzyna; Mero, Herieth R.; Wadsworth, Jemma
Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping...... methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within...... sequencing. Samples (n = 71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious...
Eliana S. Paladino
Full Text Available ABSTRACT: The bacterium Pasteurella multocida is a frequent cause of porcine respiratory disease complex in finishing pigs. Historically, the bacterium is recognized as an opportunistic agent, causing secondary bacterial pneumonia in pigs. Several Brazilian reports have suggested the ability of P. multocida to cause primary pulmonary infection that leads to the death of finishing pigs prior to slaughter. The aim of this study was to evaluate anatomopathological pulmonary findings associated with P. multocida infection that were obtained from animals with clinical respiratory disease and from animals at slaughter. Twenty-five lung samples from 14 herds of finishing pigs with acute clinical respiratory disease and 19 lungs collected at slaughter from a different set of 14 herds were studied. In all lung samples, bacterial isolation was performed, and only samples with pure P. multocida growth were included in the study. Gross and histopathological lesions were evaluated, as well as Influenza A, porcine circovirus type 2 (PCV2 and Mycoplasma hyopneumoniae co-infections. Pleuritis and pericarditis were more often observed in clinical samples (P<0.05. Moreover, there was a numerical trend indicating that pericarditis, lymphadenomegaly and cavity exudates were more often present in clinical samples. Thirteen lung samples were negative to M. hyopneumoniae, Influenza A and PCV2 by immunohistochemistry (IHC, with only P. multocida identified. In these cases, gross lesions such as pleuritis, pericarditis and lymphadenomegaly were always present, and no histologic lesions indicative of other agents such as Actinobacillus pleuropneumoniae, Actinobacillus suis or Haemophilus parasuis were observed. These findings suggest the ability of some P. multocida isolates to cause primary respiratory and systemic infection. However, in this study, it was not possible to determine specific virulence markers to explain these findings.
Yeh, Kuo-Ming; Chiu, Sheng-Kung; Lin, Chii-Lan; Huang, Li-Yueh; Tsai, Yu-Kuo; Chang, Jen-Chang; Lin, Jung-Chung; Chang, Feng-Yee; Siu, Leung-Kei
The virulence role of surface antigens in a single serotype of Klebsiella pneumoniae strain have been studied, but little is known about whether their contribution will vary with serotype. To investigate the role of K and O antigen in hyper-virulent strains, we constructed O and K antigen deficient mutants from serotype K1 STL43 and K2 TSGH strains from patients with liver abscess, and characterized their virulence in according to the abscess formation and resistance to neutrophil phagocytosis, serum, and bacterial clearance in liver. Both of K1 and K2-antigen mutants lost their wildtype resistance to neutrophil phagocytosis and hepatic clearance, and failed to cause abscess formation. K2-antigen mutant became serum susceptible while K1-antigen mutant maintained its resistance to serum killing. The amount of glucuronic acid, indicating the amount of capsular polysaccharide (CPS, K antigen), was inversed proportional to the rate of phagocytosis. O-antigen mutant of serotype K1 strains had significantly more amount of CPS, and more resistant to neutrophil phagocytosis than its wildtype counterpart. O-antigen mutants of serotype K1 and K2 strains lost their wildtype serum resistance, and kept resistant to neutrophil phagocytosis. While both mutants lacked the same O1 antigen, O-antigen mutant of serotype K1 became susceptible to liver clearance and cause mild abscess formation, but its serotype K2 counterpart maintained these wildtype virulence. We conclude that the contribution of surface antigens to virulence of K. pneumoniae strains varies with serotypes.
Thi Hoa Ngo
Full Text Available Streptococcus suis is a pathogen of major economic significance to the swine industry and is increasingly recognized as an emerging zoonotic agent in Asia. In Vietnam, S. suis is the leading cause of bacterial meningitis in adult humans. Zoonotic transmission is most frequently associated with serotype 2 strains and occupational exposure to pigs or consumption of infected pork. To gain insight into the role of pigs for human consumption as a reservoir for zoonotic infection in southern Vietnam, we determined the prevalence and diversity of S. suis carriage in healthy slaughterhouse pigs. Nasopharyngeal tonsils were sampled from pigs at slaughterhouses serving six provinces in southern Vietnam and Ho Chi Minh City area from September 2006 to November 2007. Samples were screened by bacterial culture. Isolates of S. suis were serotyped and characterized by multi locus sequence typing (MLST and pulse field gel electrophoresis (PFGE. Antibiotic susceptibility profiles and associated genetic resistance determinants, and the presence of putative virulence factors were determined. 41% (222/542 of pigs carried S. suis of one or multiple serotypes. 8% (45/542 carried S. suis serotype 2 which was the most common serotype found (45/317 strains, 14%. 80% of serotype 2 strains belonged to the MLST clonal complex 1,which was previously associated with meningitis cases in Vietnam and outbreaks of severe disease in China in 1998 and 2005. These strains clustered with representative strains isolated from patients with meningitis in PFGE analysis, and showed similar antimicrobial resistance and virulence factor profiles. Slaughterhouse pigs are a major reservoir of S. suis serotype 2 capable of causing human infection in southern Vietnam. Strict hygiene at processing facilities, and health education programs addressing food safety and proper handling of pork should be encouraged.
Zhang, Yong; Hong, Mei; Sun, Qiang; Zhu, Shuangli; Tsewang; Li, Xiaolei; Yan, Dongmei; Wang, Dongyan; Xu, Wenbo
Molecular methods, based on sequencing the region encoding the complete VP1 or P1 protein, have enabled the rapid identification of new enterovirus serotypes. In the present study, the complete genome of a newly discovered enterovirus serotype, strain Q0011/XZ/CHN/2000 (hereafter referred to as Q0011), was sequenced and analyzed. The virus, isolated from a stool sample from a patient with acute flaccid paralysis in the Tibet region of China in 2000, was characterized by amplicon sequencing and comparison to a GenBank database of enterovirus nucleotide sequences. The nucleotide sequence encoding the complete VP1 capsid protein is most closely related to the sequences of viruses within the species enterovirus B (EV-B), but is less than 72.1% identical to the homologous sequences of the recognized human enterovirus serotypes, with the greatest homology to EV-B101 and echovirus 32. Moreover, the deduced amino acid sequence of the complete VP1 region is less than 84.7% identical to those of the recognized serotypes, suggesting that the strain is a new serotype of enterovirus within EV-B. The virus was characterized as a new enterovirus type, named EV-B111, by the Picornaviridae Study Group of the International Committee on Taxonomy of Viruses. Low positive rate and titer of neutralizing antibody against EV-B111 were found in the Tibet region of China. Nearly 50% of children ≤5 years had no neutralizing antibody against EV-B111. So the extent of transmission and the exposure of the population to this new EV are very limited. This is the first identification of a new serotype of human enterovirus in China, and strain Q0011 was designated the prototype strain of EV-B111. Copyright © 2014 Elsevier B.V. All rights reserved.
Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro
In order to clarify the taxonomic position of serotypes 20, 22 and 26 of Streptococcus suis, biochemical and molecular genetic studies were performed on isolates (SUT-7, SUT-286(T), SUT-319, SUT-328 and SUT-380) reacted with specific antisera of serotypes 20, 22 or 26 from the saliva of healthy pigs as well as reference strains of serotypes 20, 22 and 26. Comparative recN gene sequencing showed high genetic relatedness among our isolates, but marked differences from the type strain S. suis NCTC 10234(T), i.e. 74.8-75.7 % sequence similarity. The genomic relatedness between the isolates and other strains of species of the genus Streptococcus, including S. suis, was calculated using the average nucleotide identity values of whole genome sequences, which indicated that serotypes 20, 22 and 26 should be removed taxonomically from S. suis and treated as a novel genomic species. Comparative sequence analysis revealed 99.0-100 % sequence similarities for the 16S rRNA genes between the reference strains of serotypes 20, 22 and 26, and our isolates. Isolate STU-286(T) had relatively high 16S rRNA gene sequence similarity with S. suis NCTC 10234(T) (98.8 %). SUT-286(T) could be distinguished from S. suis and other closely related species of the genus Streptococcus using biochemical tests. Due to its phylogenetic and phenotypic similarities to S. suis we propose naming the novel species Streptococcus parasuis sp. nov., with SUT-286(T) ( = JCM 30273(T) = DSM 29126(T)) as the type strain. © 2015 IUMS.
Furfaro, Lucy L; Chang, Barbara J; Payne, Matthew S
Streptococcus agalactiae is the leading cause of early-onset neonatal sepsis. Culture-based screening methods lack the sensitivity of molecular assays and do not indicate serotype; a potentially important virulence marker. We aimed to develop a multiplex PCR to detect S. agalactiae while simultaneously identifying serotypes Ia, Ib, and III; commonly associated with infant disease. Primers were designed to target S. agalactiae serotype-specific cps genes and the dltS gene. The assay was validated with 512 vaginal specimens from pregnant women. 112 (21.9%) were dltS positive, with 14.3%, 0.9%, and 6.3% of these identified as cps Ia, Ib, and III, respectively. Our assay is a specific and sensitive method to simultaneously detect S. agalactiae and serotypes Ia, Ib, and III in a single step. It is of high significance for clinical diagnostic applications and also provides epidemiological data on serotype, information that may be important for vaccine development and other targeted non-antibiotic therapies. Copyright © 2017 Elsevier Inc. All rights reserved.
Bogomolnaya Lydia M
Full Text Available Abstract Background Salmonellosis is one of the most important bacterial food borne illnesses worldwide. A major source of infection for humans is consumption of chicken or egg products that have been contaminated with Salmonella enterica serotype Typhimurium, however our knowledge regarding colonization and persistence factors in the chicken is small. Results We compared intestinal and systemic colonization of 1-week-old White Leghorn chicks and Salmonella-resistant CBA/J mice during infection with Salmonella enterica serotype Typhimurium ATCC14028, one of the most commonly studied isolates. We also studied the distribution of wild type serotype Typhimurium ATCC14028 and an isogenic invA mutant during competitive infection in the cecum of 1-week-old White Leghorn chicks and 8-week-old CBA/J mice. We found that although the systemic levels of serotype Typhimurium in both infected animal models are low, infected mice have significant splenomegaly beginning at 15 days post infection. In the intestinal tract itself, the cecal contents are the major site for recovery of serotype Typhimurium in the cecum of 1-week-old chicks and Salmonella-resistant mice. Additionally we show that only a small minority of Salmonellae are intracellular in the cecal epithelium of both infected animal models, and while SPI-1 is important for successful infection in the murine model, it is important for association with the cecal epithelium of 1-week-old chicks. Finally, we show that in chicks infected with serotype Typhimurium at 1 week of age, the level of fecal shedding of this organism does not reflect the level of cecal colonization as it does in murine models. Conclusion In our study, we highlight important differences in systemic and intestinal colonization levels between chick and murine serotype Typhimurium infections, and provide evidence that suggests that the role of SPI-1 may not be the same during colonization of both animal models.
N. M. Alyab'eva
Full Text Available Aim: to compare two methods of S. pneumoniae molecular typing: classic serological method and the multiplex polymerase chain reaction (M-PCR assay modified in accordance to the date on the serotypes circulating in Russian Federation. Patients and methods: 420 pneumococcal isolates mainly from non-sterile loci were analyzed. After microbiological identification pneumococci were serologically typed with the means of specific antiserum produced by Staten Serum Institute (Denmark in latex agglutination test and/or capsular swelling method. At the same time we performed series of the M-PCR, which consisted of 7 consecutive reactions at the most. Results: serotype was identified by the means of serological method in all 420 strains of S. pneumoniae; in total we determined 24 different serotypes. By the means of the M-PCR we succeeded in identification of 95% (399/420 examined strains, and 90% of them were typed during the first 3 reactions. All isolates failed to be typed by M-PCR (n =21 have serotypes not included into the composition of the M-PCR. The results of serological and molecular typing were identical in 99,2% (396/399 of the isolates; 3 strains showed contradictory results: serotype 19A was found on serological assay and serotype 19F — on PCR assay. Conclusions: the introduced modification of M-PCR allows correct identification of pneumococcal serotype more than in 90% of strains circulating in the Russian Federation, including all serotypes of pneumococcal polysaccharide conjugate vaccine.
Mølbak, K.; Gerner-Smidt, P.; Wegener, Henrik Caspar
Until recently, Salmonella enterica serotype Enteritidis has remained sensitive to most antibiotics. However, national surveillance data from Denmark show that quinolone resistance in S. Enteritidis has increased from 0.8% in 1995 to 8.5% in 2000. These data support concerns that the current use...... of quinolone in food animals leads to increasing resistance in S. Enteritidis and that action should be taken to limit such use....
Logan Julie MJ
Full Text Available Abstract Background The fliC and fljB genes in Salmonella code for the phase 1 (H1 and phase 2 (H2 flagellin respectively, the rfb cluster encodes the majority of enzymes for polysaccharide (O antigen biosynthesis, together they determine the antigenic profile by which Salmonella are identified. Sequencing and characterisation of fliC was performed in the development of a molecular serotyping technique. Results FliC sequencing of 106 strains revealed two groups; the g-complex included those exhibiting "g" or "m,t" antigenic factors, and the non-g strains which formed a second more diverse group. Variation in fliC was characterised and sero-specific motifs identified. Furthermore, it was possible to identify differences in certain H antigens that are not detected by traditional serotyping. A rapid short sequencing assay was developed to target serotype-specific sequence motifs in fliC. The assay was evaluated for identification of H1 antigens with a panel of 55 strains. Conclusion FliC sequences were obtained for more than 100 strains comprising 29 different H1 alleles. Unique pyrosequencing profiles corresponding to the H1 component of the serotype were generated reproducibly for the 23 alleles represented in the evaluation panel. Short read sequence assays can now be used to identify fliC alleles in approximately 97% of the 50 medically most important Salmonella in England and Wales. Capability for high throughput testing and automation give these assays considerable advantages over traditional methods.
Bachanek-Bankowska, Katarzyna; Mero, Herieth R; Wadsworth, Jemma; Mioulet, Valerie; Sallu, Raphael; Belsham, Graham J; Kasanga, Christopher J; Knowles, Nick J; King, Donald P
Rapid, reliable and accurate diagnostic methods provide essential support to programmes that monitor and control foot-and-mouth disease (FMD). While pan-specific molecular tests for FMD virus (FMDV) detection are well established and widely used in endemic and FMD-free countries, current serotyping methods mainly rely either on antigen detection ELISAs or nucleotide sequencing approaches. This report describes the development of a panel of serotype-specific real-time RT-PCR assays (rRT-PCR) tailored to detect FMDV lineages currently circulating in East Africa. These assays target sequences within the VP1-coding region that share high intra-lineage identity, but do not cross-react with FMD viruses from other serotypes that circulate in the region. These serotype-specific assays operate with the same thermal profile as the pan-diagnostic tests making it possible to run them in parallel to produce C T values comparable to the pan-diagnostic test detecting the 3D-coding region. These assays were evaluated alongside the established pan-specific molecular test using field samples and virus isolates collected from Tanzania, Kenya and Ethiopia that had been previously characterised by nucleotide sequencing. Samples (n=71) representing serotype A (topotype AFRICA, lineage G-I), serotype O (topotypes EA-2 and EA-4), serotype SAT 1 (topotype I (NWZ)) and serotype SAT2 (topotype IV) were correctly identified with these rRT-PCR assays. Furthermore, FMDV RNA from samples that did not contain infectious virus could still be serotyped using these assays. These serotype-specific real-time RT-PCR assays can detect and characterise FMDVs currently circulating in East Africa and hence improve disease control in this region. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.
Nova Nayarit-Ballesteros; María Salud Rubio-Lozano; Enrique Delgado-Suárez; Danilo Méndez-Medina; Diego Braña-Varela; Oscar Rodas-Suárez
Objective. To determine the serotype and antibiotic resistance profile of Salmonella spp. isolated from retail ground beef in Mexico City. Materials and methods. A total of 100 samples of ground beef were analyzed. The pathogen was isolated by conventional methods and confirmed by PCR (invA gene, 284 bp). The antibiotic resistance profile was determined by the Kirby-Bauer method while serotyping was performed according to the Kauffman-White scheme. Results. We isolated a total of 19 strains o...
Cortelli Sheila Cavalca
Full Text Available This study examined the prevalence of highly and minimally leukotoxic Actinobacillus actinomycetemcomitans in patients with periodontal disease. Pooled subgingival plaque samples from 136 patients with some form of periodontal disease were examined. Subjects were between 14 and 76 years of age. Clinical examinations included periodontal pocket depth (PD, plaque index (PI and bleeding index (BI. The obtained plaque samples were examined for the presence of highly or minimally leukotoxic A. actinomycetemcomitans strains by the polymerase chain reaction (PCR. Chi-square and logistic regression were performed to evaluate the results. Forty-seven subjects were diagnosed with gingivitis, 70 with chronic periodontitis and 19 with aggressive periodontitis. According to chi-square there was no significant correlation detected between PD (chi2 = 0.73, PI (chi2 = 0.35, BI (chi2 = 0.09 and the presence of the highly leukotoxic A. actinomycetemcomitans. The highly leukotoxic A. actinomycetemcomitans strains were correlated with subjects that were 28 years of age and younger (chi2 = 7.41. There was a significant correlation between highly leukotoxic A. actinomycetemcomitans and aggressive periodontitis (chi2 = 22.06. This study of a Brazilian cohort confirms the strong association between highly leukotoxic A. actinomycetemcomitans strains and the presence of aggressive periodontitis.
A.B. Ludi (A.); D.L. Horton; Y. Li (Y.); M. Mahapatra (M.); D.P. King (D.); N.J. Knowles (N.); C.A. Russell (Colin); J.H. Paton; J.L.N. Wood; D.J. Smith (Derek James); J.M. Hammond (J.)
textabstractThe current measures to control foot-and-mouth disease (FMD) include vaccination, movement control and slaughter of infected or susceptible animals. One of the difficulties in controlling FMD by vaccination arises due to the substantial diversity found among the seven serotypes of FMD
Pride, Michael W; Huijts, Susanne M; Wu, Kangjian; Souza, Victor; Passador, Sherry; Tinder, Chunyan; Song, Esther; Elfassy, Arik; McNeil, Lisa; Menton, Ronald; French, Roger; Callahan, Janice; Webber, Chris; Gruber, William C; Bonten, Marc J M; Jansen, Kathrin U
To improve the clinical diagnosis of pneumococcal infection in bacteremic and nonbacteremic community-acquired pneumonia (CAP), a Luminex technology-based multiplex urinary antigen detection (UAD) diagnostic assay was developed and validated. The UAD assay can simultaneously detect 13 different serotypes of Streptococcus pneumoniae by capturing serotype-specific S. pneumoniae polysaccharides (PnPSs) secreted in human urine. Assay specificity is achieved by capturing the polysaccharides with serotype-specific monoclonal antibodies (MAbs) on spectrally unique microspheres. Positivity for each serotype was based on positivity cutoff values calculated from a standard curve run on each assay plate together with positive- and negative-control urine samples. The assay is highly specific, since significant signals are detected only when each PnPS was paired with its homologous MAb-coated microspheres. Validation experiments demonstrated excellent accuracy and precision. The UAD assay and corresponding positivity cutoff values were clinically validated by assessing 776 urine specimens obtained from patients with X-ray-confirmed CAP. The UAD assay demonstrated 97% sensitivity and 100% specificity using samples obtained from patients with bacteremic, blood culture-positive CAP. Importantly, the UAD assay identified Streptococcus pneumoniae (13 serotypes) in a proportion of individuals with nonbacteremic CAP, a patient population for which the pneumococcal etiology of CAP was previously difficult to assess. Therefore, the UAD assay provides a specific, noninvasive, sensitive, and reproducible tool to support vaccine efficacy as well as epidemiological evaluation of pneumococcal disease, including CAP, in adults.
Dolz, Roser; Vergara-Alert, Júlia; Pérez, Mónica; Pujols, Joan; Majó, Natàlia
Infectious bronchitis (IB) is a worldwide disease affecting chickens of all ages and causing important economic losses in poultry industry. Despite being one of the predominant IB virus (IBV) serotype in several European countries, slightly is known about pathogenesis and pathogenicity of Italy 02 serotype. In this study chicks and old hens were infected by oculo-nasal route with Italy 02 serotype. Clinical signs, gross and microscopic findings were evaluated, viral nucleic acid detection was assessed by in situ hybridization (ISH) in several tissues and viral RNA was detected by RT-PCR in trachea, kidney and nasal and cloacal swabs. Italy 02 serotype was demonstrated to cause severe respiratory and renal damage in one-day old chicks but not in adult hens in which only respiratory disease and drop in egg production was observed. The use of ISH technique demonstrated the presence of viral RNA in nasal turbinates prior to trachea, but more consistent and longer replication periods in enterocytes of lower gastrointestinal tract. The detection of viral nucleic acid in gut by RT-PCR was consistent and more persistent viral shedding was detected in faeces than in nasal exudates. We describe a complete update of IBV distribution in tissues by the use of molecular techniques and we also provide and in-depth pathological characterization of the new Italy 02 IBV serotype. Furthermore, new data about IBV pathogenesis essential in field control is afforded. Copyright Â© 2011 Elsevier B.V. All rights reserved.
Takayama, Koichi; Reynolds, Paul N.; Short, Joshua J.; Kawakami, Yosuke; Adachi, Yasuo; Glasgow, Joel N.; Rots, Marianne G.; Krasnykh, Victor; Douglas, Joanne T.; Curiel, David T.
The efficiency of cancer gene therapy with recombinant adenoviruses based on serotype 5 (Ad5) has been limited partly because of variable, and often low, expression by human primary cancer cells of the primary cellular-receptor which recognizes the knob domain of the fiber protein, the coxsackie and adenovirus receptor (CAR). As a means of circumventing CAR deficiency, Ad vectors have been retargeted by utilizing chimeric fibers possessing knob domains of alternate Ad serotypes. We have reported that ovarian cancer cells possess a primary receptor for Ad3 to which the Ad3 knob binds independently of the CAR-Ad5 knob interaction. Furthermore, an Ad5-based chimeric vector, designated Ad5/3, containing a chimeric fiber proteins possessing the Ad3 knob, demonstrates CAR-independent tropism by virtue of targeting the Ad3 receptor. Based on these findings, we hypothesized that a mosaic virus possessing both the Ad5 knob and the Ad3 knob on the same virion could utilize either primary receptor, resulting in expanded tropism. In this study, we generated a dual-knob mosaic virus by coinfection of 293 cells with Ad5-based and Ad5/3-based vectors. Characterization of the resultant virions confirmed the incorporation of both Ad5 and Ad3 knobs in the same particle. Furthermore, this mosaic virus was able to utilize either receptor, CAR and the Ad3 receptor, for virus attachment to cells. Enhanced Ad infectivity with the mosaic virus was shown in a panel of cell lines, with receptor profiles ranging from CAR-dominant to Ad3 receptor-dominant. Thus, this mosaic virus strategy may offer the potential to improve Ad-based gene therapy approaches by infectivity enhancement and tropism expansion
Full Text Available Avian paramyxovirus (APMV serotypes 1-9 have been isolated from many different avian species. APMV-1 (Newcastle disease virus is the only well-characterized serotype, because of the high morbidity, mortality, and economic loss caused by highly virulent strains. Very little is known about the pathogenesis, replication, virulence, and tropism of the other APMV serotypes. Here, this was evaluated for prototypes strains of APMV serotypes 2-9 in cell culture and in chickens and ducks. In cell culture, only APMV-1, -3 and -5 induced syncytium formation. In chicken DF1 cells, APMV-3 replicated with an efficiency approaching that of APMV-1, while APMV-2 and -5 replicated to lower, intermediate titers and the others were much lower. Mean death time (MDT assay in chicken eggs and intracerebral pathogenicity index (ICPI test in 1-day-old SPF chicks demonstrated that APMV types 2-9 were avirulent. Evaluation of replication in primary neuronal cells in vitro as well as in the brains of 1-day-old chicks showed that, among types 2-9, only APMV-3 was neurotropic, although this virus was not neurovirulent. Following intranasal infection of 1-day-old and 2-week-old chickens, replication of APMV types 2-9 was mostly restricted to the respiratory tract, although APMV-3 was neuroinvasive and neurotropic (but not neurovirulent and also was found in the spleen. Experimental intranasal infection of 3-week-old mallard ducks with the APMVs did not produce any clinical signs (even for APMV-1 and exhibited restricted viral replication of the APMVs (including APMV-1 to the upper respiratory tract regardless of their isolation source, indicating avirulence of APMV types 1-9 in mallard ducks. The link between the presence of a furin cleavage site in the F protein, syncytium formation, systemic spread, and virulence that has been well-established with APMV-1 pathotypes was not evident with the other APMV serotypes.
Hayashida, H.; Poulsen, Knud; Kilian, Mogens
. actinomycetemcomitans strains examined harboured a single genomic sequence with homology to the hgpA gene encoding haemoglobin-binding protein A in Haemophilus influenzae. However, in all three strains belonging to the JP2 clone and in one serotype e strain hgpA was a pseudogene. Seven other strains possessed...... a functional hgpA gene which, according to insertion mutagenesis experiments, was responsible for the ability of these strains to utilize haemoglobin as a source of iron. Thus, the presence of an hgpA pseudogene and the inability to use human haemoglobin as an iron source discriminate the high-toxic JP2 clone...
Liu, Yu; Chen, Zhou; Jiang, Zhengqiang; Yan, Qiaojuan; Yang, Shaoqing
A β-galactosidase gene (PbBGal2A) was cloned from Paenibacillus barengoltzii and expressed in Escherichia coli. The in silico analysis of the deduced amino acid sequences revealed that PbBGal2A shared the highest identity of 40% with the characterized glycoside hydrolase (GH) family 2 β-galactosidase from Actinobacillus pleuropneumoniae. The recombinant β-galactosidase (PbBGal2A) was purified with a molecular mass of 124.2kDa on SDS-PAGE. The optimal pH and temperature of PbBGal2A were determined to be pH 7.5 and 45°C, respectively. PbBGal2A was stable within pH 6.0-8.0 and up to 45°C. It completely hydrolyzed the lactose in milk and whey powder solution. In addition, PbBGal2A exhibited high transglycosylation activity and a maximum yield of 47.9% (w/w) for galactooligosaccharides (GOS) production was obtained in 8h at a lactose concentration of 350g/L. These properties make PbBGal2A an ideal candidate for commercial use in the production of lactose-free milk and GOS. Copyright © 2017. Published by Elsevier B.V.
Mitobe, Jiro; Sinha, Ritam; Mitra, Soma; Nag, Dhrubajyoti; Saito, Noriko; Shimuta, Ken; Koizumi, Nobuo; Koley, Hemanta
Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.
Full Text Available Few live attenuated vaccines protect against multiple serotypes of bacterial pathogen because host serotype-specific immune responses are limited to the serotype present in the vaccine strain. Here, immunization with a mutant of Shigella flexneri 2a protected guinea pigs against subsequent infection by S. dysenteriae type 1 and S. sonnei strains. This deletion mutant lacked the RNA-binding protein Hfq leading to increased expression of the type III secretion system via loss of regulation, resulting in attenuation of cell viability through repression of stress response sigma factors. Such increased antigen production and simultaneous attenuation were expected to elicit protective immunity against Shigella strains of heterologous serotypes. Thus, the vaccine potential of this mutant was tested in two guinea pig models of shigellosis. Animals vaccinated in the left eye showed fewer symptoms upon subsequent challenge via the right eye, and even survived subsequent intestinal challenge. In addition, oral vaccination effectively induced production of immunoglobulins without severe side effects, again protecting all animals against subsequent intestinal challenge with S. dysenteriae type 1 or S. sonnei strains. Antibodies against common virulence proteins and the O-antigen of S. flexneri 2a were detected by immunofluorescence microscopy. Reaction of antibodies with various strains, including enteroinvasive Escherichia coli, suggested that common virulence proteins induced protective immunity against a range of serotypes. Therefore, vaccination is expected to cover not only the most prevalent serotypes of S. sonnei and S. flexneri 2a, but also various Shigella strains, including S. dysenteriae type 1, which produces Shiga toxin.
Full Text Available Hand, foot, and mouth disease (HFMD is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71 and Coxsackievirus A16 (CV-A16 being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus.Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40 and 27.13 for CV-A16 (IQR: 23.15, 31.34, with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation. EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the
Takahashi, Saki; Liao, Qiaohong; Van Boeckel, Thomas P; Xing, Weijia; Sun, Junling; Hsiao, Victor Y; Metcalf, C Jessica E; Chang, Zhaorui; Liu, Fengfeng; Zhang, Jing; Wu, Joseph T; Cowling, Benjamin J; Leung, Gabriel M; Farrar, Jeremy J; van Doorn, H Rogier; Grenfell, Bryan T; Yu, Hongjie
Hand, foot, and mouth disease (HFMD) is a common childhood illness caused by serotypes of the Enterovirus A species in the genus Enterovirus of the Picornaviridae family. The disease has had a substantial burden throughout East and Southeast Asia over the past 15 y. China reported 9 million cases of HFMD between 2008 and 2013, with the two serotypes Enterovirus A71 (EV-A71) and Coxsackievirus A16 (CV-A16) being responsible for the majority of these cases. Three recent phase 3 clinical trials showed that inactivated monovalent EV-A71 vaccines manufactured in China were highly efficacious against HFMD associated with EV-A71, but offered no protection against HFMD caused by CV-A16. To better inform vaccination policy, we used mathematical models to evaluate the effect of prospective vaccination against EV-A71-associated HFMD and the potential risk of serotype replacement by CV-A16. We also extended the model to address the co-circulation, and implications for vaccination, of additional non-EV-A71, non-CV-A16 serotypes of enterovirus. Weekly reports of HFMD incidence from 31 provinces in Mainland China from 1 January 2009 to 31 December 2013 were used to fit multi-serotype time series susceptible-infected-recovered (TSIR) epidemic models. We obtained good model fit for the two-serotype TSIR with cross-protection, capturing the seasonality and geographic heterogeneity of province-level transmission, with strong correlation between the observed and simulated epidemic series. The national estimate of the basic reproduction number, R0, weighted by provincial population size, was 26.63 for EV-A71 (interquartile range [IQR]: 23.14, 30.40) and 27.13 for CV-A16 (IQR: 23.15, 31.34), with considerable variation between provinces (however, predictions about the overall impact of vaccination were robust to this variation). EV-A71 incidence was projected to decrease monotonically with higher coverage rates of EV-A71 vaccination. Across provinces, CV-A16 incidence in the post-EV-A71
Lyhs, Ulrike; Kulkas, Laura; Katholm, Jorgen
not differentiate between populations isolated from different host species. Isolates from humans and cattle differed in lactose fermentation, which is encoded on the accessory genome and represents an adaptation to the bovine mammary gland. Serotype IV-ST196 isolates were obtained from multiple dairy herds in both...
Carmo, Andreia Moreira Dos Santos; Suzuki, Rodrigo Buzinaro; Cabral, Aline Diniz; Costa, Renata Torres da; Massari, Gabriela Pena; Riquena, Michele Marcondes; Fracasso, Helio Augusto Alves; Eterovic, Andre; Marcili, Arlei; Sperança, Márcia Aparecida
Dengue virus, represented by four distinct, genetically diverse serotypes, is the etiologic agent of asymptomatic to severe hemorrhagic diseases. The spatiotemporal dynamics of dengue serotypes and its association to specific diseases vary among the different regions worldwide. By 2007, and in São Paulo State, Brazil, dengue-case concentration in urban centers had changed to increased incidence in small- and medium-sized towns, the case of Marília. The aim of this article was to distinguish dengue serotypes circulating during the 2007 Marília outbreak and define their association to demographic and hematological patient profiles, as well as the phylogenetic relationships among the different viruses. PCR amplicons corresponding to the junction of capsid and dengue pre-membrane encoding genes, obtained from dengue serologically positive patients, were sequenced. Hematological and demographic data of patients with different Dengue serotypes were evaluated by univariate and bivariate statistics. Dengue PCR sequences were used in phylogenetic relationships analyzed for maximum parsimony. Molecular typing confirmed co-circulation of the dengue serotypes 1 (DENV1) and 3 (DENV3), which presented divergent correlation patterns with regard to hematological descriptors. The increase in atypical lymphocytes, a likely indication of virus load, could be significantly associated to a decrease in leukocyte counts in the DENV3 group and platelet in the DENV1. Phylogenetic reconstitution revealed the introduction of DENV1 from northern Brazil and local divergence of DENV3 by either microevolution or viral introduction from other geographical regions or both. Dengue dynamics showed regional molecular-epidemiologic specificity, which has important implications for introduction of vaccines, disease management, and transmission control. Copyright © 2017 Elsevier B.V. All rights reserved.
Full Text Available Dengue is one of the most important and wide-spread viral infections affecting human populations. The last few decades have seen a dramatic increase in the global burden of dengue, with the virus now being endemic or near-endemic in over 100 countries world-wide. A recombinant tetravalent vaccine candidate (CYD-TDV has recently completed Phase III clinical efficacy trials in South East Asia and Latin America and has been licensed for use in several countries. The trial results showed moderate-to-high efficacies in protection against clinical symptoms and hospitalisation but with so far unknown effects on transmission and infections per se. Model-based predictions about the vaccine's short- or long-term impact on the burden of dengue are therefore subject to a considerable degree of uncertainty. Furthermore, different immune interactions between dengue's serotypes have frequently been evoked by modelling studies to underlie dengue's oscillatory dynamics in disease incidence and serotype prevalence. Here we show how model assumptions regarding immune interactions in the form of antibody-dependent enhancement, temporary cross-immunity and the number of infections required to develop full immunity can significantly affect the predicted outcome of a dengue vaccination campaign. Our results thus re-emphasise the important gap in our current knowledge concerning the effects of previous exposure on subsequent dengue infections and further suggest that intervention impact studies should be critically evaluated by their underlying assumptions about serotype immune-interactions.
Park, Saeyoung; Gerber, Sabina; Lee, Jean C.
Most Staphylococcus aureus isolates produce either a serotype 5 (CP5) or 8 (CP8) capsular polysaccharide, and the CP antigens are targets for vaccine development. Since CP5 and CP8 have similar trisaccharide repeating units, it is important to identify an epitope shared by both CP5 and CP8. To characterize cross-reactivity between CP5 and CP8, the immunogenicity of CP5 and CP8 conjugate vaccines in mice and rabbits was evaluated by serological assays. Immune sera were also tested for function...
Culshaw, Abigail; Ladell, Kristin; Gras, Stephanie; McLaren, James E; Miners, Kelly L; Farenc, Carine; van den Heuvel, Heleen; Gostick, Emma; Dejnirattisai, Wanwisa; Wangteeraprasert, Apirath; Duangchinda, Thaneeya; Chotiyarnwong, Pojchong; Limpitikul, Wannee; Vasanawathana, Sirijitt; Malasit, Prida; Dong, Tao; Rossjohn, Jamie; Mongkolsapaya, Juthathip; Price, David A; Screaton, Gavin R
Adaptive immune responses protect against infection with dengue virus (DENV), yet cross-reactivity with distinct serotypes can precipitate life-threatening clinical disease. We found that clonotypes expressing the T cell antigen receptor (TCR) β-chain variable region 11 (TRBV11-2) were 'preferentially' activated and mobilized within immunodominant human-leukocyte-antigen-(HLA)-A*11:01-restricted CD8 + T cell populations specific for variants of the nonstructural protein epitope NS3 133 that characterize the serotypes DENV1, DENV3 and DENV4. In contrast, the NS3 133 -DENV2-specific repertoire was largely devoid of such TCRs. Structural analysis of a representative TRBV11-2 + TCR demonstrated that cross-serotype reactivity was governed by unique interplay between the variable antigenic determinant and germline-encoded residues in the second β-chain complementarity-determining region (CDR2β). Extensive mutagenesis studies of three distinct TRBV11-2 + TCRs further confirmed that antigen recognition was dependent on key contacts between the serotype-defined peptide and discrete residues in the CDR2β loop. Collectively, these data reveal an innate-like mode of epitope recognition with potential implications for the outcome of sequential exposure to heterologous DENVs.
Milanoi, Sylvia; Ongus, Juliette R; Gachara, George; Coldren, Rodney; Bulimo, Wallace
Human rhinoviruses (HRVs) are a well-established cause of the common cold and recent studies indicated that they may be associated with severe acute respiratory illnesses (SARIs) like pneumonia, asthma, and bronchiolitis. Despite global studies on the genetic diversity of the virus, the serotype diversity of these viruses across diverse geographic regions in Kenya has not been characterized. This study sought to characterize the serotype diversity of HRV strains that circulated in Kenya in 2008. A total of 517 archived nasopharyngeal samples collected in a previous respiratory virus surveillance program across Kenya in 2008 were selected. Participants enrolled were outpatients who presented with influenza-like (ILI) symptoms. Real-time RT-PCR was employed for preliminary HRV detection. HRV-positive samples were amplified using RT-PCR and thereafter the nucleotide sequences of the amplicons were determined followed by phylogenetic analysis. Twenty-five percent of the samples tested positive for HRV. Phylogenetic analysis revealed that the Kenyan HRVs clustered into three main species comprising HRV-A (54%), HRV-B (12%), and HRV-C (35%). Overall, 20 different serotypes were identified. Intrastrain sequence homology among the Kenyan strains ranged from 58% to 100% at the nucleotide level and 55% to 100% at the amino acid level. These results show that a wide range of HRV serotypes with different levels of nucleotide variation were present in Kenya. Furthermore, our data show that HRVs contributed substantially to influenza-like illness in Kenya in 2008. © 2016 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd.
Full Text Available Abstract Background In Australia in June 2001, a unique pneumococcal vaccine schedule commenced for Indigenous infants; seven-valent pneumococcal conjugate vaccine (7PCV given at 2, 4, and 6 months of age and 23-valent pneumococcal polysaccharide vaccine (23PPV at 18 months of age. This study presents carriage serotypes following this schedule. Methods We conducted cross sectional surveys of pneumococcal carriage in Aboriginal children 0 to 6 years of age living in remote Aboriginal communities (RACs in 2003 and 2005. Nasal secretions were collected and processed according to published methods. Results 902 children (mean age 25 months living in 29 communities in 2003 and 818 children (mean age 35 months in 17 communities in 2005 were enrolled. 87% children in 2003 and 96% in 2005 had received two or more doses of 7PCV. From 2003 to 2005, pneumococcal carriage was reduced from 82% to 76% and reductions were apparent in all age groups; 7PCV-type carriage was reduced from 11% to 8%, and 23PPV-non-7PCV-type carriage from 31% to 25% respectively. Thus non-23PPV-type carriage increased from 57% to 67%. All these changes were statistically significant, as were changes for some specific serotypes. Shifts could not be attributed to vaccination alone. The top 10 of 40 serotypes identified were (in descending order 16F, 19A, 11A, 6C, 23B, 19F, 6A, 35B, 6B, 10A and 35B. Carriage of penicillin non-susceptible (MIC > = 0.12 μg/mL strains (15% overall was detected in serotypes (descending order 19A, 19F, 6B, 16F, 11A, 9V, 23B, and in 4 additional serotypes. Carriage of azithromycin resistant (MIC > = 2 μg/mL strains (5% overall, was detected in serotypes (descending order 23B, 17F, 9N, 6B, 6A, 11A, 23F, and in 10 additional serotypes including 6C. Conclusion Pneumococcal carriage remains high (~80% in this vaccinated population. Uptake of both pneumococcal vaccines increased, and carriage was reduced between 2003 and 2005. Predominant serotypes in combined
Background: Diarrheal disease and its complications remain a major cause of morbidity and mortality in children. The prevalence and antibiogram of E. coli as causative agents of diarrhea vary from region to region, and even within countries in the same geographical area. Objectives: To determine the serotype and ...
Antibiogram of E. coli serotypes isolated from children aged under five with acute diarrhea in Bahir Dar town. Ayrikim Adugna1, Mulugeta Kibret1, Bayeh Abera2, Endalkachew Nibret1, Melaku Adal1. 1. Department of Biology, Science College, Bahir Dar University. 2. Department of Microbiology, Parasitology and ...
Full Text Available Recombinant adenovirus serotype 5 (Ad5 vectors represent one of the most efficient gene delivery vectors in life sciences. However, Ad5 is dependent on expression of the coxsackievirus-adenovirus-receptor (CAR on the surface of target cell for efficient transduction, which limits it's utility for certain cell types. Herein we present a new vector, Ad5PTDf35, which is an Ad5 vector having serotype 35 fiber-specificity and Tat-PTD hexon-modification. This vector shows dramatically increased transduction capacity of primary human cell cultures including T cells, monocytes, macrophages, dendritic cells, pancreatic islets and exocrine cells, mesenchymal stem cells and tumor initiating cells. Biodistribution in mice following systemic administration (tail-vein injection show significantly reduced uptake in the liver and spleen of Ad5PTDf35 compared to unmodified Ad5. Therefore, replication-competent viruses with these modifications may be further developed as oncolytic agents for cancer therapy. User-friendly backbone plasmids containing these modifications were developed for compatibility to the AdEasy-system to facilitate the development of surface-modified adenoviruses for gene delivery to difficult-to-transduce cells in basic, pre-clinical and clinical research.
Stoughton, William B; Gold, Jenifer
A 12-week-old female dromedary camel (Camelus dromedarius) calf was evaluated because of acute (blood, peritoneal fluid, and pleural fluid samples indicated Streptococcus equi subsp zooepidemicus septicemia as the etiology for the polyserositis (ie, alpaca fever). Treatment with IV broad-spectrum antimicrobials, an NSAID, and pleural drainage was initiated. Clinical signs of pleuropneumonia, peritonitis, and systemic infection improved rapidly 24 hours after initiation of medical treatment. The calf was discharged from the hospital after 11 days, and antimicrobial treatment continued for 2 weeks after discharge. At follow-up approximately 4 weeks after hospital discharge (6 weeks after the initial examination), there were no clinical signs suggestive of relapse or any reported complications. S equi subsp zooepidemicus may cause polyserositis in Old World camelids (eg, dromedary camels) with signs similar to those seen in New World camelids (eg, alpaca and llama). The rapid response to medical treatment for the patient described suggested that S equi subsp zooepidemicus-induced polyserositis (alpaca fever) in dromedary camels may respond favorably to appropriate treatment. Reducing stress, reducing overcrowding, and separate housing of equids and camelids are suggested. Further studies are needed to better assess the epidemiology of alpaca fever in dromedary camels in North America.
Boscher, Evelyne; Houard, Emmanuelle; Denis, Martine
This study was undertaken to acquire new data on the prevalence of Listeria monocytogenes in sows and fattening pigs in farrow-to-finish pig farms, and to analyze distribution of serotypes and genotypes of the bacterium within farms. Detection of L. monocytogenes was carried out on 730 pooled feces samples from sows in 73 pig farms and on 172 pooled feces samples from fattening pigs in 43 of these farms. Isolates were serotyped and typed by pulsed-field gel electrophoresis. For sows, 46% of the farms and 11% of the samples were positive for L. monocytogenes. A total of 124 isolates were collected and distributed in four serotypes: 1/2a (41%), 1/2b (36%), 4b (21%), and 1/2c (2%). Positive farms harbored one to three serotypes. The genetic diversity was high; 51 genetic profiles were obtained with 25, 16, 9, and 1 for the serotypes 1/2a, 1/2b, 4b, and 1/2c, respectively. Positive farms harbored 1 to 6 genetic profiles. Isolates showing similar genotypes occurred in several farms. For fattening pigs, 25% of the farms and 14.5% of the samples were positive for L. monocytogenes. The 34 isolates belonged to four serotypes: 1/2a (32%), 1/2b (41%), 4b (24%), and 1/2c (3%). They were distributed in 20 genotypes: 6 for 1/2a; 8 for 1/2b, 5 for 4b, and 1 for 1/2c. Similar serotypes and pulsotypes were recovered in sows and fattening pigs from the same farms, suggesting common sources of contamination.
Sónia T Almeida
Full Text Available Among the over 90 serotypes of Streptococcus pneumoniae described, serotypes 1, 5, and 7F account for a significant proportion of invasive disease worldwide and are now covered by the most recent 10- and 13-valent pneumococcal conjugate vaccines (PCVs. The epidemiology of these serotypes in carriage remains poorly studied because they are rarely detected. We aimed to gain insights into the epidemiology and population structure of serotypes 1, 5 and 7F carried by children in Portugal before PCV10 and PCV13 became widely used. Isolates obtained in cross-sectional studies carried out over a 15-year period (1996-2010 were retrospectively pooled and characterized. Of 5,123 pneumococci obtained, 70 were associated with serotypes 1 (n = 21, 5 (n = 7, and 7F (n = 42. The highest prevalence detected was 3.3% for serotype 1 in 2006, 1% for serotype 5 in 2009, and 3.3% for serotype 7F in 2006; Serotype 1 was associated with PMEN international clones Sweden(1-28(ST306 and Sweden(1-40(ST304; serotype 5 was associated with Colombia(5-19(ST289; and serotype 7F was associated with Netherlands(7F-39(ST191. All these isolates were fully susceptible. Most carriers of serotypes 1 (86%, 5 (86%, and 7F (91% were older than two years but a significant association with older age was only observed for serotype 7F (p = 0.006. Evidence for cross-transmission was obtained. In conclusion, we were able to detect and characterize the rarely carried serotypes 1, 5, and 7F among healthy children in Portugal. These data will constitute an important baseline for upcoming surveillance studies aimed to establish the impact of novel PCVs targeting these serotypes in carriage.
Subramaniam, Saravanan; Mohapatra, Jajati K; Das, Biswajit; Sharma, Gaurav K; Biswal, Jitendra K; Mahajan, Sonalika; Misri, Jyoti; Dash, Bana B; Pattnaik, Bramhadev
Foot-and-mouth disease virus (FMDV) serotype Asia1 was first reported in India in 1951, where three major genetic lineages (B, C and D) of this serotype have been described until now. In this study, the capsid protein coding region of serotype Asia1 viruses (n = 99) from India were analyzed, giving importance to the viruses circulating since 2007. All of the isolates (n = 50) recovered during 2007-2013 were found to group within the re-emerging cluster of lineage C (designated as sublineage C(R)). The evolutionary rate of sublineage C(R) was estimated to be slightly higher than that of the serotype as a whole, and the time of the most recent common ancestor for this cluster was estimated to be approximately 2001. In comparison to the older isolates of lineage C (1993-2001), the re-emerging viruses showed variation at eight amino acid positions, including substitutions at the antigenically critical residues VP279 and VP2131. However, no direct correlation was found between sequence variations and antigenic relationships. The number of codons under positive selection and the nature of the selection pressure varied widely among the structural proteins, implying a heterogeneous pattern of evolution in serotype Asia1. While episodic diversifying selection appears to play a major role in shaping the evolution of VP1 and VP3, selection pressure acting on codons of VP2 is largely pervasive. Further, episodic positive selection appears to be responsible for the early diversification of lineage C. Recombination events identified in the structural protein coding region indicates its probable role in adaptive evolution of serotype Asia1 viruses.
Gunnarsson, Ingólfur Bragi; Alvarado-Morales, Merlin; Angelidaki, Irini
Biogas is an attractive renewable energy carrier. However, it contains CO2 which limits certain applications of biogas. Here we report a novel approach for removing CO2 from biogas and capturing it as a biochemical through a biological process. This approach entails converting CO2 into bio...... and titre, CO2 consumption rate and CH4 purity. When using biogas as the only CO2 source at 140 kPa, the CO2 consumption rate corresponded to 2.59 L CO2 L-1 d-1 with a final succinic acid titre of 14.4 g L-1. Under this pressure condition the highest succinic acid yield and biogas quality reached......-succinic acid using the bacterial strain Actinobacillus succinogenes 130Z, and simultaneously producing high purity CH4 (>95%). Results showed that when pressure during fermentation was increased from 101.325 to 140 kPa, higher CO2 solubility was achieved, thereby positively affecting final succinic acid yield...
Lampe, A S; Schroijen, M A; Smith, S J
A 72-year-old man, having had an artificial valve for almost 20 years now, presented with tiredness that had persisted for several weeks and reported weight loss of 5 kg. In more recent days he experienced fever and cold shivers, and an associated dry cough. Bearing in mind the potential for endocarditis, blood cultures were grown. In this, we identified a small, Gram-negative rod with a small, smooth, raised colony that grew slowly. We considered a micro-organism from the 'HACEK group', which is a group of micro-organisms including Haemophilus aphrophilus, Haemophilus paraphrophilus, Cardiobacterium hominis, Eikenella corrodens, Kingella kingae and Aggregatibacter (formerly: Actinobacillus) actinomycetemcomitans. More careful observation revealed that the bacteria formed star-shaped colonies, proving that A. actinomycetemcomitans was the cause of this non-acute endocarditis. The patient received antibiotic treatment. Because non-acute endocarditis is often caused by hidden abnormalities in the mouth or teeth and A. actinomycetemcomitans plays an important role in severe cases of peridontitis, a dental surgeon was consulted. The dental surgeon diagnosed multifocal peridontitis and treated the patient, who was able to leave the hospital after 6 weeks of antibiotic treatment.
Brncic, Nada; Gorup, Lari; Strcic, Miroslav; Abram, Maja; Mustac, Elvira
Nontyphoidal salmonellae can cause breast infection only exceptionally. A case of breast abscess in a 70-year-old man due to Salmonella enterica serotype Enteritidis (Salmonella Enteritidis) is reported. The infection was successfully treated with a combination of surgical and antibiotic treatment.
Schou, Kirstine Klitgaard; Rundsten, Carsten Friis; Jensen, Tim Kåre
and survive within the hostile environment of host macrophages. This persistence within macrophages may be related to urease activity, mobilization of various stress responses and active evasion of the host defenses by cell surface sialylation. Conclusions/Significance The data presented here highlight...
Pacheco, Juan M.; Lee, Kwang-Nyeong; Eschbaumer, Michael; Bishop, Elizabeth A.; Hartwig, Ethan J.; Pauszek, Steven J.; Smoliga, George R.; Kim, Su-Mi; Park, Jong-Hyeon; Ko, Young-Joon; Lee, Hyang-Sim; Tark, Dongseob; Cho, In-Soo; Kim, Byounghan; Rodriguez, Luis L.; Arzt, Jonathan
Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain of serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic. PMID:26735130
Wekesa, Sabenzia N.; Sangula, Abraham K.; Belsham, Graham
Serotype A is the most genetically and antigenically diverse of the foot-and-mouth disease virus (FMDV) serotypes. Records of its occurrence in Kenya date back to 1952 and the antigenic diversity of the outbreak viruses in this region is reflected by the current use of two different vaccine strains...... (K5/1980 and K35/1980) and previous use of two other strains (K18/66 and K179/71). This study aimed at enhancing the understanding of the patterns of genetic variation of serotype A FMDV in Kenya. The complete VP1 coding region sequences of 38 field isolates, identified as serotype A FMDV, collected...... between 1964 and 2013 were determined. Coalescent-based methods were used to infer times of divergence of the virus strains and the evolutionary rates alongside 27 other serotype A FMDV sequences from Genbank and the World Reference Laboratory (WRL). This study represents the first comprehensive genetic...
Thomas R. Connor
Full Text Available For 100 years, it has been obvious that Salmonella enterica strains sharing the serotype with the formula 1,4,,12:b:1,2—now known as Paratyphi B—can cause diseases ranging from serious systemic infections to self-limiting gastroenteritis. Despite considerable predicted diversity between strains carrying the common Paratyphi B serotype, there remain few methods that subdivide the group into groups that are congruent with their disease phenotypes. Paratyphi B therefore represents one of the canonical examples in Salmonella where serotyping combined with classical microbiological tests fails to provide clinically informative information. Here, we use genomics to provide the first high-resolution view of this serotype, placing it into a wider genomic context of the Salmonella enterica species. These analyses reveal why it has been impossible to subdivide this serotype based upon phenotypic and limited molecular approaches. By examining the genomic data in detail, we are able to identify common features that correlate with strains of clinical importance. The results presented here provide new diagnostic targets, as well as posing important new questions about the basis for the invasive disease phenotype observed in a subset of strains.
Full Text Available Since the use of pneumococcal conjugate vaccines PCV7 and PCV13 in children became widespread, invasive pneumococcal disease (IPD has dramatically decreased. Nevertheless, there has been a rise in incidence of Streptococcus pneumoniae non-vaccine serotypes (NVT colonising the human nasopharynx. Nasopharyngeal colonisation, an essential step in the development of S. pneumoniae-induced IPD, is associated with biofilm formation. Although the capsule is the main pneumococcal virulence factor, the formation of pneumococcal biofilms might, in fact, be limited by the presence of capsular polysaccharide (CPS.We used clinical isolates of 16 emerging, non-PCV13 serotypes as well as isogenic transformants of the same serotypes. The biofilm formation capacity of isogenic transformants expressing CPSs from NVT was evaluated in vitro to ascertain whether this trait can be used to predict the emergence of NVT. Fourteen out of 16 NVT analysed were not good biofilm formers, presumably because of the presence of CPS. In contrast, serotypes 11A and 35B formed ≥45% of the biofilm produced by the non-encapsulated M11 strain.This study suggest that emerging, NVT serotypes 11A and 35B deserve a close surveillance.
Lloyd-Jones, Katie; Mahapatra, Mana; Upadhyaya, Sasmita; Paton, David J; Babu, Aravindh; Hutchings, Geoff; Parida, Satya
Foot-and-mouth disease (FMD) is endemic in Eastern Africa with circulation of multiple serotypes of the virus in the region. Most of the outbreaks are caused by serotype O followed by serotype A. The lack of concerted FMD control programmes in Africa has provided little incentive for vaccine producers to select vaccines that are tailored to circulating regional isolates creating further negative feedback to deter the introduction of vaccine-based control schemes. In this study a total of 80 serotype O FMD viruses (FMDV) isolated from 1993 to 2012 from East and North Africa were characterized by virus neutralisation tests using bovine antisera to three existing (O/KEN/77/78, O/Manisa and O/PanAsia-2) and three putative (O/EA/2002, O/EA/2009 and O/EA/2010) vaccine strains and by capsid sequencing. Genetically, these viruses were grouped as either of East African origin with subdivision into four topotypes (EA-1, 2, 3 and 4) or of Middle-East South Asian (ME-SA) topotype. The ME-SA topotype viruses were mainly detected in Egypt and Libya reflecting the trade links with the Middle East countries. There was good serological cross-reactivity between the vaccine strains and most of the field isolates analysed, indicating that vaccine selection should not be a major constraint for control of serotype O FMD by vaccination, and that both local and internationally available commercial vaccines could be used. The O/KEN/77/78 vaccine, commonly used in the region, exhibited comparatively lower percent in vitro match against the predominant topotypes (EA-2 and EA-3) circulating in the region whereas O/PanAsia-2 and O/Manisa vaccines revealed broader protection against East African serotype O viruses, even though they genetically belong to the ME-SA topotype. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Damgaard, Christian; Reinholdt, Jesper; Enevold, Christian
Objectives: The aim was to elucidate whether levels of circulating antibodies to Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis correlate to loss of attachment, as a marker for periodontitis and cardiovascular disease (CVD). Design: Sera were collected from 576 participants...... of the Danish Health Examination Survey (DANHES). Immunoglobulin G antibodies against lipopolysaccharide (LPS) and protein antigens from the a, b and c serotypes of A. actinomycetemcomitans and P. gingivalis were quantified by titration in ELISA plates coated with a mixture of antigens prepared...... by disintegration of bacteria. Results: Levels of antibodies against P. gingivalis (OR = 1.48) and A. actinomycetemcomitans (1.31) associated with periodontitis, as determined by univariable logistic regression analysis. These antibody levels also associated with CVD (1.17 and 1.37), respectively, However, after...
Rylev, Mette; Kilian, Mogens
putative periodontal pathogens and particular subsets of these species vary between ethnic groups. Few of these differences can, with the limited information available, be directly related to differences in periodontal disease prevalence. Asian populations are regularly colonized with Actinobacillus...... actinomycetemcomitans serotype c with questionable pathogenic potential. Conversely, the JP2 clone of A. actinomycetemcomitans has enhanced virulence and causes significantly higher prevalence of aggressive periodontitis in adolescents whose descent can be traced back to the Mediterranean and Western parts of Africa....... Some genetically distinct types of Porphyromonas gingivalis are more associated with disease than others, but additional work is required to relate this to clinical differences. CONCLUSIONS: Studies that take into account differences linked to the genetics of both patients and potential pathogens...
Siemer, B.L.; Harrington, C.S.; Nielsen, E.M.
health. The remaining 30 groups contained isolates from humans, chickens and associated food products, cattle, sheep, turkeys, ostriches and/or dogs. Strains assigned to serotypes 2, 6/7, 11 and 12 formed major clusters at the 77.6% S-level. Most other serotypes did not form homogeneous clusters....... conclusions: High-resolution genotyping applied to strains from a comprehensive range of sources provides evidence for multiple sources of sporadic C. jejuni infection. The results suggest that public health protection measures should be directed at all foods of animal origin. Significance and Impct...... diarrhoea and diverse animal and environmental sources were collected mainly through a National surveillance programme in Denmark and serotyped by use of the established 'Penner' scheme. Genetic relationships among these isolates, and the archetypal serotype reference strains, were assessed by numerical...
Bowen, David M; Lewis, Jessica A; Lu, Wenzhe; Schein, Catherine H
Designing proteins that reflect the natural variability of a pathogen is essential for developing novel vaccines and drugs. Flaviviruses, including Dengue (DENV) and West Nile (WNV), evolve rapidly and can "escape" neutralizing monoclonal antibodies by mutation. Designing antigens that represent many distinct strains is important for DENV, where infection with a strain from one of the four serotypes may lead to severe hemorrhagic disease on subsequent infection with a strain from another serotype. Here, a DENV physicochemical property (PCP)-consensus sequence was derived from 671 unique sequences from the Flavitrack database. PCP-consensus proteins for domain 3 of the envelope protein (EdomIII) were expressed from synthetic genes in Escherichia coli. The ability of the purified consensus proteins to bind polyclonal antibodies generated in response to infection with strains from each of the four DENV serotypes was determined. The initial consensus protein bound antibodies from DENV-1-3 in ELISA and Western blot assays. This sequence was altered in 3 steps to incorporate regions of maximum variability, identified as significant changes in the PCPs, characteristic of DENV-4 strains. The final protein was recognized by antibodies against all four serotypes. Two amino acids essential for efficient binding to all DENV antibodies are part of a discontinuous epitope previously defined for a neutralizing monoclonal antibody. The PCP-consensus method can significantly reduce the number of experiments required to define a multivalent antigen, which is particularly important when dealing with pathogens that must be tested at higher biosafety levels. Copyright © 2012 Elsevier Ltd. All rights reserved.
Markus W. Weishaupt
Full Text Available Vaccines against S. pneumoniae, one of the most prevalent bacterial infections causing severe disease, rely on isolated capsular polysaccharide (CPS that are conjugated to proteins. Such isolates contain a heterogeneous oligosaccharide mixture of different chain lengths and frame shifts. Access to defined synthetic S. pneumoniae CPS structures is desirable. Known syntheses of S. pneumoniae serotype 3 CPS rely on a time-consuming and low-yielding late-stage oxidation step, or use disaccharide building blocks which limits variability. Herein, we report the first iterative automated glycan assembly (AGA of a conjugation-ready S. pneumoniae serotype 3 CPS trisaccharide. This oligosaccharide was assembled using a novel glucuronic acid building block to circumvent the need for a late-stage oxidation. The introduction of a washing step with the activator prior to each glycosylation cycle greatly increased the yields by neutralizing any residual base from deprotection steps in the synthetic cycle. This process improvement is applicable to AGA of many other oligosaccharides.
Cui, Chen; Huang, Ligang; Li, Jing; Zou, Xingqi; Zhu, Yuanyuan; Xie, Lei; Zhao, Qizu; Yang, Limin; Liu, Wenjun
Recombinant structural protein VP1 of foot-and-mouth disease virus serotype O was expressed in Escherichia coli and then purified using Nickel affinity chromatography. A chemiluminescent enzyme immunoassay (CLEIA) method was established using the purified recombinant protein as coating antigen to detect antibody of foot-and-mouth disease virus serotype O in swine. The specificity of VP1-CLEIA method is 100%. The coefficients of variation in the plate and between plates are 1.10%-6.70% and 0.66%-4.80%, respectively. Comparing with the commercial indirect ELISA kit or liquid phase block ELISA kit, the calculated coincidence rate is 93.50% or 94.00%. The high specificity and stability suggested this detection method can be used to monitor the antibody level of foot-and-mouth disease virus serotype O in swine.
Peter Charbel Issa
Full Text Available Adeno-associated viral vectors (AAV have been shown to be safe in the treatment of retinal degenerations in clinical trials. Thus, improving the efficiency of viral gene delivery has become increasingly important to increase the success of clinical trials. In this study, structural domains of different rAAV serotypes isolated from primate brain were combined to create novel hybrid recombinant AAV serotypes, rAAV2/rec2 and rAAV2/rec3. The efficacy of these novel serotypes were assessed in wild type mice and in two models of retinal degeneration (the Abca4(-/- mouse which is a model for Stargardt disease and in the Pde6b(rd1/rd1 mouse in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette. We show that these novel hybrid serotypes can transduce retinal tissue in mice and primates efficiently, although no more than AAV2/2 and rAAV2/5 serotypes. Transduction efficiency appeared lower in the Abca4(-/- mouse compared to wild type with all vectors tested, suggesting an effect of specific retinal diseases on the efficiency of gene delivery. Shuffling of AAV capsid domains may have clinical applications for patients who develop T-cell immune responses following AAV gene therapy, as specific peptide antigen sequences could be substituted using this technique prior to vector re-treatments.
Charbel Issa, Peter; De Silva, Samantha R; Lipinski, Daniel M; Singh, Mandeep S; Mouravlev, Alexandre; You, Qisheng; Barnard, Alun R; Hankins, Mark W; During, Matthew J; Maclaren, Robert E
Adeno-associated viral vectors (AAV) have been shown to be safe in the treatment of retinal degenerations in clinical trials. Thus, improving the efficiency of viral gene delivery has become increasingly important to increase the success of clinical trials. In this study, structural domains of different rAAV serotypes isolated from primate brain were combined to create novel hybrid recombinant AAV serotypes, rAAV2/rec2 and rAAV2/rec3. The efficacy of these novel serotypes were assessed in wild type mice and in two models of retinal degeneration (the Abca4(-/-) mouse which is a model for Stargardt disease and in the Pde6b(rd1/rd1) mouse) in vivo, in primate tissue ex-vivo, and in the human-derived SH-SY5Y cell line, using an identical AAV2 expression cassette. We show that these novel hybrid serotypes can transduce retinal tissue in mice and primates efficiently, although no more than AAV2/2 and rAAV2/5 serotypes. Transduction efficiency appeared lower in the Abca4(-/-) mouse compared to wild type with all vectors tested, suggesting an effect of specific retinal diseases on the efficiency of gene delivery. Shuffling of AAV capsid domains may have clinical applications for patients who develop T-cell immune responses following AAV gene therapy, as specific peptide antigen sequences could be substituted using this technique prior to vector re-treatments.
Antunes, P; Campos, J; Mourão, J; Ribeiro, T G; Novais, C; Peixe, L
Non-typhoidal Salmonella is an important burden, particularly in developing countries of the African region. We report for the first time in Angola, a sub-Saharan African country with commercial/travel relationships with Europe, an unexpectedly high occurrence of Salmonella (n = 12/63, 19%) from a high diversity of sources, particularly farm and wild animals. The detection of diverse serotypes (n = 12), involving putative new S. enterica subsp. salamae serotypes, is also of note, reinforcing the need for a comprehensive surveillance in Angola critical to identify animal/food/environmental sources of salmonellosis with impact on animal health, local people, tourists and exported products.
Wang, Shaohui; Meng, Qingmei; Dai, Jianjun; Han, Xiangan; Han, Yue; Ding, Chan; Liu, Haiwen; Yu, Shengqing
Systemic infections by avian pathogenic Escherichia coli (APEC) are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR) assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs) bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.
Full Text Available Systemic infections by avian pathogenic Escherichia coli (APEC are economically devastating to poultry industries worldwide. E. coli strains belonging to serotypes O1, O2, O18 and O78 are preferentially associated with avian colibacillosis. The rfb gene cluster controlling O antigen synthesis is usually various among different E. coli serotypes. In present study, the rfb gene clusters of E. coli serotypes O1, O2, O18 and O78 were characterized and compared. Based on the serotype-specific genes in rfb gene cluster, an allele-specific polymerase chain reaction (PCR assay was developed. This PCR assay was highly specific and reliable for sero-typing of APEC O1, O2, O18 and O78 strains. The sensitivity of the assay was determined as 10 pg DNA or 10 colony forming units (CFUs bacteria for serotypes O2 and O18 strains, and 500 pg DNA or 1,000 CFUs bacteria for serotypes O1 and O78 strains. Using this PCR system, APEC isolates and the infected tissue samples were categorized successfully. Furthermore, it was able to differentiate the serotypes for the samples with multi-agglutination in the traditional serum agglutination assay. Therefore, the allele-specific PCR is more simple, rapid and accurate assay for APEC diagnosis, epidemiologic study and vaccine development.
María Noemí Carnalla-Barajas
Conclusions: A percentage of annual decline of serotypes causing IPD and NIPD included in PCV was detected among groups not targeted to receive the vaccine, probably due to herd effect. Considering pneumococcal serotype distribution is a dynamic process, we highlight the importance of surveillance programs.
Botulinum neurotoxins (BoNTs) are some of the most poisonous natural toxins known to man and are threats to public health and safety. Previous work from our laboratory showed that BoNT serotype A (BoNT/A) complex (holotoxin with neurotoxin-associated proteins) bind and transit through the intestinal...
Petersen, L.; Nielsen, E.M.; Engberg, J.
(MRPs) of C. jejuni isolates from different sources. The serotype distribution in wildlife was significantly different from the known distributions in broilers and humans. Considerable sero- and genotype diversity was found within the wildlife collection, although two major groups of isolates within...... serotype O:12 and the O:4 complex were found. Common clonal lines among wildlife, chicken, and/or human isolates were identified within serotype O:12 and the O:4 complex. However, MRPs of O:12 and O:38 strains isolated from wildlife and other sources indicated that some clonal lines propagated in a wide...
González Martínez, F; Saavedra Lozano, J; Navarro Gómez, M L; Santos Sebastián, M M; Rodríguez Fernández, R; González Sánchez, M; Hernández-Sampelayo Matos, T
To describe the epidemiology, clinical syndromes and microbiological characteristics of serotype 19A as the main cause of invasive pneumococcal disease (IPD) in children admitted to a tertiary hospital in Spain. A retrospective (1998-2004) and prospective (2005-2009) study was conducted on children with IPD produced by serotype 19A. The study was divided into three periods (P): P1 (1998-2001) when PCV7 had not been commercialized; P2 (2002-2005) with 40% vaccine coverage among children; and P3 (2006-2009) when the vaccine was added to the Childhood Immunization Schedule in Madrid. A total of 155 isolates of Streptococcus pneumoniae (SP) producing IPD were analysed, with 21 of them being serotype 19A (14%). An increased prevalence of serotype 19A was found: 2/45 cases (4.4%) in P1, 3/41 cases (7.3%) in P2 and 16/69 cases (23.2%) in P3. It occurred mostly in children younger than 2 years (16/21; 76%). This serotype was the main cause of meningitis (5/20; 25%), pleural empyema (3/22; 14%) and bacteraemic mastoiditis (2/4; 50%). Thirteen isolates (61.5%) had an MIC ≥ 0.12μ/ml for penicillin in extra-meningeal infections, and 3 of the 5 isolates causing meningitis (60%) had an MIC ≥ 1μ/ml for cefotaxime. Serotype 19A was the main causal agent of IPD in the PCV7 era (P3), with high antibiotic resistance rates. This serotype was responsible for all types of IPD, being the main cause of meningitis. Copyright © 2012 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.
Chang, Zhili; Lu, Shuting; Chen, Lihong; Jin, Qi; Yang, Jian
Shigella, the causative agent of shigellosis, is a major global public health concern, particularly in developing countries with poor sanitation. A comprehensive and current understanding of the prevalent species and serotypes of shigellosis is essential for both disease prevention and vaccine development. However, no current data are available on the causative species/serotypes of shigellosis in mainland China during the past decade. Relevant studies addressing the prevalent species of shigellosis in mainland China from January 2001 to December 2010 were identified from PubMed and the Chinese BioMedical Literature Database (in Chinese) until April 2012. A total of 131 eligible articles (136 studies) were included in this review. Meta-analyses showed that the prevalences of S. flexneri and S. sonnei were 76.2% (95% CI, 73.7%-78.5%) and 21.3% (95% CI, 19.0%-23.7%), respectively. Stratified analyses indicated a decrease in the prevalence of S. flexneri cases and an increase in the prevalence of S. sonnei cases concurrent with the rapid economic growth experienced by China in recent years. Moreover, significantly higher rates of S. sonnei were observed in the East, North and Northeast regions of China, as compared to the rest of the country. These phenomena imply the possible association between the prevalent species of Shigella and regional economic status; however, additional factors also exist and require further investigations. Moreover, the two major serotypes S. flexneri 2a and 4c accounted for 21.5% (95% CI, 16.7%-27.4%) and 12.9% (95% CI 9.8%-16.9%) of S. flexneri infections, respectively, in the past decade. However, these results were found to be frequently heterogeneous (p for Q tests review of the causative agents of shigellosis in mainland China and focuses on the importance of strengthening prevention and research efforts on S. sonnei and the newly emerged S. flexneri serotype 4c.
Wekesa, S. N.; Muwanika, V. B.; Siegismund, H. R.
Foot‐and‐mouth disease (FMD) is endemic in Kenya where four serotypes (O, A, SAT 1 and SAT 2) of the virus are currently in circulation. Within 2010 and 2011, the National Laboratory recorded an increase in the number of FMD outbreaks caused by serotype O virus. The characteristics of these virus...
Decho, Alan W; Beckman, Erin M; Chandler, G Thomas; Kawaguchi, Tomohiro
An indirect immunofluorescence approach was developed using semiconductor quantum dot nanocrystals to label and detect a specific bacterial serotype of the bacterial human pathogen Vibrio parahaemolyticus, attached to small marine animals (i.e. benthic harpacticoid copepods), which are suspected pathogen carriers. This photostable labeling method using nanotechnology will potentially allow specific serotypes of other bacterial pathogens to be detected with high sensitivity in a range of systems, and can be easily applied for sensitive detection to other Vibrio species such as Vibrio cholerae
Swaminathan Sathyamangalam; Khanna Navin; Rajendra Pilankatta; Khanam Saima
Abstract Background Dengue is a public health problem of global significance for which there is neither an effective antiviral therapy nor a preventive vaccine. It is a mosquito-borne viral disease, caused by dengue (DEN) viruses, which are members of the Flaviviridae family. There are four closely related serotypes, DEN-1, DEN-2, DEN-3 and DEN-4, each of which is capable of causing disease. As immunity to any one serotype can potentially sensitize an individual to severe disease during expos...
Jakobsen, Maria; Askou, Anne Louise; Stenderup, Karin; Rosada, Cecilia; Dagnæs-Hansen, Frederik; Jensen, Thomas G; Corydon, Thomas J; Mikkelsen, Jacob Giehm; Aagaard, Lars
Skin is an easily accessible organ, and therapeutic gene transfer to skin remains an attractive alternative for the treatment of skin diseases. Although we have previously documented potent lentiviral gene delivery to human skin, vectors based on adeno-associated virus (AAV) rank among the most promising gene delivery tools for in vivo purposes. Thus, we compared the potential usefulness of various serotypes of recombinant AAV vectors and lentiviral vectors for gene transfer to human skin in a xenotransplanted mouse model. Vector constructs encoding firefly luciferase were packaged in AAV capsids of serotype 1, 2, 5, 6, 8, and 9 and separately administered by intradermal injection in human skin transplants. For all serotypes, live bioimaging demonstrated low levels of transgene expression in the human skin graft, and firefly luciferase expression was observed primarily in neighboring tissue outside of the graft. In contrast, gene delivery by intradermally injected lentiviral vectors was efficient and led to extensive and persistent firefly luciferase expression within the human skin graft only. The study demonstrates the limited capacity of single-stranded AAV vectors of six commonly used serotypes for gene delivery to human skin in vivo.
Mirari Prasadajudio, Mulya Rahma Karyanti, Lia Waslia
Full Text Available Objectives: Indonesia is known for high incidence of typhoid fever especially in children. This study aimed to observe antibiotic susceptibility in circulating Salmonella typhi serotypes in children with typhoid. Methods: A cross sectional study design was conducted. A total of 142 blood samples from children between 1-18 years old clinically diagnosed with suspected typhoid fever were recruited between January 2012 and July 2013 from six health centers in Jakarta. Confirmed cases were retrieved based on S. typhi isolate finding in blood culture. Antimicrobial susceptibility was investigated and PCR was used to detect S. typhi serotypes using fliB, fliC and aroC genes. Results: The prevalence of confirmed typhoid case based on isolate finding was 22 (15.5%. Twenty of S. typhi isolates expressed fliC gene carrying H:d allele, the other two expressed j allele, while only two samples expressed fliB, all showed no difference in pathogenicity and antimicrobial resistance. Conclusions: Circulating serotypes found in typhoid children in Jakarta, Indonesia are still susceptible even to the firstline antimicrobials. Thus, chloramphenicol, ampicillin and co-trimoxazole are still recommended. J Microbiol Infect Dis 2017; 7(1: 29-35
Gelanew, Tesfaye; Hunsperger, Elizabeth
Dengue, caused by one of the four serologically distinct dengue viruses (DENV-1 to - 4), is a mosquito-borne disease of serious global health significance. Reliable and cost-effective diagnostic tests, along with effective vaccines and vector-control strategies, are highly required to reduce dengue morbidity and mortality. Evaluation studies revealed that many commercially available NS1 antigen (Ag) tests have limited sensitivity to DENV-4 serotype compared to the other three serotypes. These studies indicated the need for development of new NS1 Ag detection test with improved sensitivity to DENV-4. An NS1 capture enzyme linked immunoassay (ELISA) specific to DENV-4 may improve the detection of DENV-4 cases worldwide. In addition, a serotype-specific NS1 Ag test identifies both DENV and the infecting serotype. In this study, we used a small-ubiquitin-like modifier (SUMO*) cloning vector to express a SUMO*-DENV-4 rNS1 fusion protein to develop NS1 DENV-4 specific monoclonal antibodies (MAbs). These newly developed MAbs were then optimized for use in an anti-NS1 DENV-4 capture ELISA. The serotype specificity and sensitivity of this ELISA was evaluated using (i) supernatants from DENV (1-4)-infected Vero cell cultures, (ii) rNS1s from all the four DENV (1-4) and, (iii) rNS1s of related flaviviruses (yellow fever virus; YFV and West Nile virus; WNV). From the evaluation studies of the newly developed MAbs, we identified three DENV-4 specific anti-NS1 MAbs: 3H7A9, 8A6F2 and 6D4B10. Two of these MAbs were optimal for use in a DENV-4 serotype-specific NS1 capture ELISA: MAb 8A6F2 as the capture antibody and 6D4B10 as a detection antibody. This ELISA was sensitive and specific to DENV-4 with no cross-reactivity to other three DENV (1-3) serotypes and other heterologous flaviviruses. Taken together these data indicated that our MAbs are useful reagents for the development of DENV-4 immunodiagnostic tests.
Olvera, A; Cerdà-Cuéllar, M; Mentaberre, G; Casas-Diaz, E; Lavin, S; Marco, I; Aragon, V
Haemophilus parasuis is a colonizer of the upper respiratory tract of pigs and the etiological agent of Glässer's disease, which is characterized by a fibrinous polyserositis, meningitis and arthritis. Glässer's disease has never been reported in wild boar (Sus scrofa), although antibodies against H. parasuis have been detected. The goal of this study was to confirm the presence of this bacterium in wild boar by bacterial isolation and to compare the strains to H. parasuis from domesticated pigs. Therefore, nasal swabs from 42 hunted wild boars were processed for bacterial isolation and subsequent H. parasuis identification by specific PCR, biochemical tests and 16S rRNA gene sequencing. Two different strains of H. parasuis from two wild boars were isolated. These strains belonged to serotype 2 and were included by 16S rRNA gene sequencing and MLST analysis in a cluster with other H. parasuis strains of nasal origin from domestic pigs. During this study, Actinobacillus minor and Actinobacillus indolicus, which are NAD-dependent Pasteurellaceae closely related to H. parasuis, were also isolated. Our results indicate similarities in the respiratory microbiota of wild boars and domestic pigs, and although H. parasuis was isolated from wild boars, more studies are needed to determine if this could be a source of H. parasuis infection for domestic pigs.
Gerbier, G.; Baldet, T.; Tran, A.; Hendrickx, G.; Guis, H.; Mintiens, K.; Elbers, A.R.W.; Staubach, C.
The knowledge of the place where a disease is first introduced and from where it later spreads is a key element for the understanding of an epizootic. For a contagious disease, the main method is back tracing. For a vector-borne disease such as the Bluetongue virus serotype 8 epizootic that occurred
Li, Yu-An; Ji, Zhenying; Wang, Xiaobo; Wang, Shifeng; Shi, Huoying
Streptococcus suis is one of the major pathogens that cause economic losses in the swine industry worldwide. However, current bacterins only provide limited prophylactic protection in the field. An ideal vaccine against S. suis should protect pigs against the clinical diseases caused by multiple serotypes, or at least protect against the dominant serotype in a given geographic region. A new recombinant Salmonella enterica serotype Choleraesuis vaccine vector, rSC0011, that is based on the regulated delayed attenuation system and regulated delayed antigen synthesis system, was developed recently. In this study, an improved recombinant attenuated Salmonella Choleraesuis vector, rSC0016, was developed by incorporating a sopB mutation to ensure adequate safety and maximal immunogenicity. In the spleens of mice, rSC0016 colonized less than rSC0011. rSC0016 and rSC0011 colonized similarly in Peyer's patches of mice. The recombinant vaccine rSC0016(pS-SaoA) induced stronger cellular, humoral, and mucosal immune responses in mice and swine against SaoA, a conserved surface protein that is present in many S. suis serotypes, than did rSC0011(pS-SaoA) without sopB or rSC0018(pS-SaoA), which is an avirulent, chemically attenuated vaccine strain. rSC0016(pS-SaoA) provided 100% protection against S. suis serotype 2 in mice and pigs, and full cross-protection against SS7 in pigs. This new vaccine vector provides a foundation for the development of a universal vaccine against multiple serotypes of S. suis in pigs.
Full Text Available ABSTRACT Glässer's disease is an emergent bacterial disease that affects swine husbandries worldwide causing important economic losses. The aetiological agent, Haemophilus parasuis, is currently divided in fifteen serovars but an increasing number of non-typeable serovars have been reported. Indirect hemagglutination (IHA is indicated as a serotyping method for H. parasuis. In the present study, we describe an additional step that aims to work around a possible obstacle in the original protocol that may compromise the outcome of this assay. We observed that the choice of anticoagulant for blood collection influences and/or impairs spontaneous adsorption of H. parasuis antigens on sheep red blood cells (SRBCs. However, regardless of the anticoagulant used, chemical treatment of SRBCs with tannic acid induces a stable antigen adsorption (sensitization step. The addition of 1% BSA to SRBCs washing buffer and to antisera dilution augments IHA specificity. Tannic acid treated SRBCs combined with thermo-resistant H. parasuis antigens increases the assay resolution. Thus, our results demonstrate an improvement in the technique of H. parasuis serotyping that will prove valuable to understand Glässer's disease epidemiology and to better characterize serovars involved in outbreaks.
Blaabjerg, Anne Katrine; Schumacher, Anna Holst; Kantsø, Bjørn
This is the first case report of recurrent invasive pneumococcal disease (IPD), specifically, due to serotype 12F. The patient described here was vaccinated with the 23-valent pneumococcal polysaccharide vaccine (PPV23) due to previous splenectomy, and an anti-pneumococcal IgG test concluded...
MLST and Whole-Genome-Based Population Analysis of Cryptococcus gattii VGIII Links Clinical, Veterinary and Environmental Strains, and Reveals Divergent Serotype Specific Sub-populations and Distant Ancestors
Firacative, Carolina; Roe, Chandler C.; Malik, Richard; Ferreira-Paim, Kennio; Escandón, Patricia; Sykes, Jane E.; Castañón-Olivares, Laura Rocío; Contreras-Peres, Cudberto; Samayoa, Blanca; Sorrell, Tania C.; Castañeda, Elizabeth; Lockhart, Shawn R.; Engelthaler, David M.; Meyer, Wieland
The emerging pathogen Cryptococcus gattii causes life-threatening disease in immunocompetent and immunocompromised hosts. Of the four major molecular types (VGI-VGIV), the molecular type VGIII has recently emerged as cause of disease in otherwise healthy individuals, prompting a need to investigate its population genetic structure to understand if there are potential genotype-dependent characteristics in its epidemiology, environmental niche(s), host range and clinical features of disease. Multilocus sequence typing (MLST) of 122 clinical, environmental and veterinary C. gattii VGIII isolates from Australia, Colombia, Guatemala, Mexico, New Zealand, Paraguay, USA and Venezuela, and whole genome sequencing (WGS) of 60 isolates representing all established MLST types identified four divergent sub-populations. The majority of the isolates belong to two main clades, corresponding either to serotype B or C, indicating an ongoing species evolution. Both major clades included clinical, environmental and veterinary isolates. The C. gattii VGIII population was genetically highly diverse, with minor differences between countries, isolation source, serotype and mating type. Little to no recombination was found between the two major groups, serotype B and C, at the whole and mitochondrial genome level. C. gattii VGIII is widespread in the Americas, with sporadic cases occurring elsewhere, WGS revealed Mexico and USA as a likely origin of the serotype B VGIII population and Colombia as a possible origin of the serotype C VGIII population. Serotype B isolates are more virulent than serotype C isolates in a murine model of infection, causing predominantly pulmonary cryptococcosis. No specific link between genotype and virulence was observed. Antifungal susceptibility testing against six antifungal drugs revealed that serotype B isolates are more susceptible to azoles than serotype C isolates, highlighting the importance of strain typing to guide effective treatment to improve the
Chen, Ke-Quan; Li, Jian; Ma, Jiang-Feng; Jiang, Min; Wei, Ping; Liu, Zhong-Min; Ying, Han-Jie
The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 μg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources. Crown Copyright Â© 2010. Published by Elsevier Ltd. All rights reserved.
Jamal, Syed M; Belsham, Graham J
Rapid and accurate diagnosis of foot-and-mouth disease (FMD) and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs) in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR) assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08)). In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT) values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4-100%] for serotype A positive samples) and specificity (100% each for serotypes O, A and Asia-1 positive samples) for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for the poor
Syed M Jamal
Full Text Available Rapid and accurate diagnosis of foot-and-mouth disease (FMD and virus serotyping are of paramount importance for control of this disease in endemic areas where vaccination is practiced. Ideally this virus characterization should be achieved without the need for virus amplification in cell culture. Due to the heterogeneity of FMD viruses (FMDVs in different parts of the world, region specific diagnostic tests are required. In this study, hydrolysable probe-based real time reverse transcription quantitative polymerase chain reaction (RT-qPCR assays were developed for specific detection and serotyping of the FMDVs currently circulating in West Eurasia. These assays were evaluated, in parallel with pan-FMDV diagnostic assays and earlier serotype-specific assays, using field samples originating from Pakistan and Afghanistan containing FMD viruses belonging to different sublineages of O-PanAsia, A-Iran05 and Asia-1 (Group-II and Group-VII (Sindh-08. In addition, field samples from Iran and Bulgaria, containing FMDVs belonging to the O-PanAsiaANT-10 sublineage were also tested. Each of the three primer/probe sets was designed to be specific for just one of the serotypes O, A and Asia-1 of FMDV and detected the RNA from the target viruses with cycle threshold (CT values comparable with those obtained with the serotype-independent pan-FMDV diagnostic assays. No cross-reactivity was observed in these assays between the heterotypic viruses circulating in the region. The assays reported here have higher diagnostic sensitivity (100% each for serotypes O and Asia-1, and 92% [95% CI = 81.4-100%] for serotype A positive samples and specificity (100% each for serotypes O, A and Asia-1 positive samples for the viruses currently circulating in West Eurasia compared to the serotyping assays reported earlier. Comparisons of the sequences of the primers and probes used in these assays and the corresponding regions of the circulating viruses provided explanations for
Vidić Branka M.
Full Text Available Data on L. hardjo infection of dairy cows in the world pint out its important role in the occurrence of health and economic problem. L. interrogans serotype hardjo has been described as the cause of miscarriages, stillbirts, or the birhs of poorly vital calves, agalactia, mastitis, and low fertility in cows. Two L. hardjo genotypes have been identified in cows, namely, hardjopraitno and hardjobovis. Serological investigations have established a drastic increase in this leptospiral infection in cows. L. hardjo has become adapted to cattle as the primary host, so that an infection is maintained in herds and becomes deeply rooted because of the permanent presence of the source of infection. It was believed that sheep were accidental hosts, but the latest research suggest that they are yet another, transitory, host for maintining this leptospira serotype. L. hardjo is also important from the aspect of human health, especially of persons who are professionally exposed to this infection. L. hardjo infection is detected using serological tests and by proving the presence of leptospira. The medicine of choice in the therapy of leptospiral infections is streptomycin (DSM. Therapy using oxytetracyclines for clinical mastitis was also proven effective. Treatment is most successful in the early stage of the disease. A single dose of streptomycin administered in infected herds reduces the duration period of leptospira excretion through urine, thus preventing the spread of infection thorugh contaminated urine. The basic components of the plan to contain leptospira are the following: serological investigations, sanitary-higiene measures, the elimination of animals which excrete leptospira through urine, therapy, vaccination, quarantine.
Metzgar, David; Osuna, Miguel; Yingst, Samuel; Rakha, Magda; Earhart, Kenneth; Elyan, Diaa; Esmat, Hala; Saad, Magdi D; Kajon, Adriana; Wu, Jianguo; Gray, Gregory C; Ryan, Margaret A; Russell, Kevin L
.... Species and serotype identities were determined using several well-validated multiplex PCR protocols culled from the literature and supplemented with a few novel primer sets designed to identify rare types...
Full Text Available Abstract Background Dengue (DEN is an infectious disease caused by the DEN virus (DENV, which belongs to the Flavivirus genus in the family Flaviviridae. It has a (+ sense RNA genome and is mainly transmitted to humans by the vector mosquito Aedes aegypti. Dengue fever (DF and dengue hemorrhagic fever (DHF are caused by one of four closely related virus serotypes (DENV-1, DENV-2, DENV-3 and DENV-4. Epidemiological and evolutionary studies have indicated that host and viral factors are involved in determining disease outcome and have proved the importance of viral genotype in causing severe epidemics. Host immune status and mosquito vectorial capacity are also important influences on the severity of infection. Therefore, an understanding of the relationship between virus variants with altered amino acids and high pathogenicity will provide more information on the molecular epidemiology of DEN. Accordingly, knowledge of the DENV serotypes and genotypes circulating in the latest DEN outbreaks around the world, including Mexico, will contribute to understanding DEN infections. Results 1. We obtained 88 isolates of DENV, 27 from Oaxaca and 61 from Veracruz. 2. Of these 88 isolates, 16 were serotype 1; 62 serotype 2; 7 serotype 3; and 2 serotype 4. One isolate had 2 serotypes (DENV-2 and -1. 3. Partial nucleotide sequences of the genes encoding C- prM (14 sequences, the NS3 helicase domain (7 sequences, the NS5 S-adenosyl methionine transferase domain (7 sequences and the RNA-dependent RNA polymerase (RdRp domain (18 sequences were obtained. Phylogenetic analysis showed that DENV-2 isolates belonged to the Asian/American genotype. In addition, the Asian/American genotype was divided into two clusters, one containing the isolates from 2001 and the other the isolates from 2005–2006 with high bootstrap support of 94%. Conclusion DENV-2 was the predominant serotype in the DF and DHF outbreak from 2005 to 2006 in Oaxaca State as well as in the 2006
Rasmussen, Thomas Bruun; Uttenthal, Åse; Fernandez, Jovita
In order to establish a rapid and reliable system for the detection of vesicular stomatitis virus (VSV), we developed a quantitative reverse transcription-PCR assay for the detection, quantification, and differentiation of the major serotypes, VSV Indiana and VSV New Jersey, using a closed......-tube multiplex format. The detection system is based on the recently invented primer-probe energy transfer (PriProET) system. A region of the gene encoding the RNA-dependent RNA polymerase was amplified by using VSV-specific primers in the presence of two serotype-specific fluorescent probes. By incorporating...... probes. The limits of detection ware found to be less than 10 50% tissue culture infective doses/ml for both serotypes. The diagnostic value of the new method was tested with clinical materials from experimentally infected pigs, and it is concluded that the method is a powerful tool for the rapid...
Full Text Available Background: Dengue virus serotyping is crucial from clinical management and epidemiological point of view. Aims: To compare efficacy of two molecular detection and typing methods, namely, multiplex reverse transcription polymerase chain reaction (RT-PCR and real-time Hybprobe assay using a panel of known dilution of four reference Dengue virus strains and a panel of sera collected from clinically suspected dengue patients. Settings: This study was conducted at a tertiary-care teaching hospital in Delhi, India. Materials and Methods: Dengue serotype specific virus strains were used as prototypes for serotyping assays. Viral load was quantified by quantitative real time reverse transcription polymerase chain reaction (qRT-PCR. Acute phase serum samples were collected from 79 patients with clinically suspected Dengue fever on their first day of presentation during September-October 2012. Viral RNA from serum and cell culture supernatant was extracted. Reverse transcription was carried out. Quantitative detection of DENV RNA from reference strain culture supernatants and each of the 79 patient samples by real-time PCR was performed using light cycler Taqman master mix kit. Serotyping was done by multiplex RT-PCR assay and Hybprobe assay. Results: The multiplex RT-PCR assay, though found to be 100% specific, couldn't serotype either patient or reference strains with viral load less than 1000 RNA copies/ml. The Hybprobe assay was found to have 100% specificity and had a lower limit of serotype detection of merely 3.54 RNA copies/ml. Conclusions: HybProbe assay has an important role especially in situations where serotyping is to be performed in clinical samples with low viral load.
Höglund Åberg, Carola; Antonoglou, Georgios; Haubek, Dorte; Kwamin, Francis; Claesson, Rolf; Johansson, Anders
The cytolethal distending toxin (Cdt) is a highly conserved exotoxin that are produced by a number of Gram negative bacteria, including Aggregatibacter actinomycetemcomitans, and affects mammalian cells by inhibiting cell division and causing apoptosis. A complete cdt-operon is present in the majority of A. actinomycetemcomitans, but the proportion of isolates that lack cdt-encoding genes (A, B and C) varies according to the population studied. The objectives of this study were to examine serotype, Cdt-genotype, and Cdt-activity in isolates of A. actinomycetemcomitans collected from an adolescent West African population and to examine the association between the carrier status of A. actinomycetemcomitans and the progression of attachment loss (AL). A total of 249 A. actinomycetemcomitans isolates from 200 Ghanaian adolescents were examined for serotype and cdt-genotype by PCR. The activity of the Cdt-toxin was examined by DNA-staining of exposed cultured cells and documented with flow cytometry. The periodontal status of the participants was examined at baseline and at a two-year follow-up. Presence of all three cdt-encoding genes was detected in 79% of the examined A. actinomycetemcomitans isolates. All these isolates showed a substantial Cdt-activity. The two different cdt-genotypes (with and without presence of all three cdt-encoding genes) showed a serotype-dependent distribution pattern. Presence of A. actinomycetemcomitans was significantly associated with progression of AL (OR = 5.126; 95% CI = [2.994-8.779], padolescents showed a distribution of serotype and cdt-genotype in line with results based on other previously studied populations. Presence of A. actinomycetemcomitans was significantly associated with disease progression, in particular the b serotype, whereas the association with disease progression was not particularly related to cdt-genotype, and Cdt-activity.
Full Text Available SM Sabbir Alam,1 Ruhul Amin,1 Mohammed Ziaur Rahman,2 M Anwar Hossain,1 Munawar Sultana11Department of Microbiology, University of Dhaka, Dhaka, Bangladesh; 2International Centre for Diarrhoeal Disease Research, Dhaka, BangladeshAbstract: Foot and mouth disease virus (FMDV, with its seven serotypes, is a highly contagious virus infecting mainly cloven-hoofed animals. The serotype Asia1 occurs mainly in Asian regions. An in-silico approach was taken to reveal the antigenic heterogeneities within the capsid protein VP1 of Asia1. A total of 47 VP1 sequences of Asia1 isolates from different countries of South Asian regions were selected, retrieved from database, and were aligned. The structure of VP1 protein was modeled using a homology modeling approach. Several antigenic sites were identified and mapped onto the three-dimensional protein structure. Variations at these antigenic sites were analyzed by calculating the protein variability index and finding mutation combinations. The data suggested that vaccine escape mutants have derived from only few mutations at several antigenic sites. Five antigenic peptides have been identified as the least variable epitopes, with just fewer amino acid substitutions. Only a limited number of serotype Asia1 antigenic variants were found to be circulated within the South Asian region. This emphasizes a possibility of formulating synthetic vaccines for controlling foot-and-mouth disease by Asia1 serotypes.Keywords: protein modeling, antigenic sites, sequence variation
Full Text Available Objective: Group B streptococci (GBS from Southern African areas have been less well characterized. Our objective was to study serotype and serovariant distribution of carrier GBS strains as part of a study of the epidemiology of GBS carriage in pregnant women from Zimbabwe. Materials and Methods: We studied GBS isolated from 121 healthy pregnant women living in Harare and surrounding areas, Zimbabwe. Capsular polysaccharide (CPS testing for serotype determination and surface-anchored protein testing for serosubtype determination were done by gene-based serotyping (PCR, except for the proteins R3 and a novel protein called Z, which were detected by antibody-based methods. Results: Strains of the CPS types Ia (15.7%, Ib (11.6%, II (8.3%, III (38.8%, V (24.0% and NT (1.7% were detected along with the strain-variable proteins Cί (15.7% of isolates, Cα (19.8%, Alp1 (epsilon-22.3%, Alp3 (5.0%, R4/Rib (46.3%, R3 (27.3%, Z (27.3%, and SAR5 (28.9%, which encodes the R5 protein. Up to four of the protein genes could be possessed or the gene product expressed by one and the same isolate. A total of 32 serovariants were detected. The findings assessed by us as most important were the very low prevalence of the gene Alp3 (Alp3 - 4.9%, high prevalence of R4 (Rib - 46.2%, the proteins R3 (27.3%, Z (27.3%, and of SAR5 (R5 - 28.9%. The low prevalence of Alp3, notably in GBS type V strains, differed from findings with CPS type V GBS from non-African areas. Bacteria of the various CPS types showed distinct CPS/protein-marker associations. Conclusion: The results are of importance in relation to regional variations of GBS phenotypes and genotypes and thus, of importance in planning and research in the context of future vaccine formulations.
Meloni, Domenico; Piras, Francesca; Mureddu, Anna; Fois, Federica; Consolati, Simonetta Gianna; Lamon, Sonia; Mazzette, Rina
In a 3-year study (2008 to 2011) to estimate the prevalence and the contamination sources of Listeria monocytogenes in pork meat in Sardinia, Italy, 211 samples were collected from five Sardinian swine slaughterhouses: 171 samples from slaughtered pigs and 40 from the slaughterhouse environment. Fifty L. monocytogenes isolates were characterized by PCR-based serotyping, presence of virulence-associated genes, and pulsed-field gel electrophoresis restriction analysis. The overall prevalence of L. monocytogenes was 33% in swine carcasses, 7% in cecal material, 23% on meat contact surfaces, and 25% on noncontact surfaces. Only two serotypes were detected: 1/2c (78%) and 1/2a (22%). In all, based on the presence of virulence-associated genes, eight pathogenic profiles were detected. Only 42% of all isolates carried the full complement of virulence-associated genes and were allotted to profile 1. Six pulsed-field gel electrophoresis profiles persisted in the slaughterhouses; restriction profiles appeared to be specific to each plant.
Full Text Available The protective efficacy of formalin-killed Streptococcus agalactiae (Group B Streptococcus, GBS serotype Ia (GBS-Ia and III (GBS-III vaccines were assessed in Nile tilapia (Oreochromis niloticus. The fish with an average weight of 34.45± 0.08 g were immunized by intraperitoneal (i.p. injection with 4 different formalin-killed vaccines prepared from GBS-Ia (1x1010 CFU/mL, GBS-III (1x1010 CFU/mL, and combined GBS-Ia and GBS-III in an equal volume at final concentrations 1x1010 CFU/mL and 2x1010 CFU/mL in comparison with the non-immunized control group. At 2 and 4 weeks post vaccination, no significant differences were observed (p>0.05 among treatments in growth performance or haemato-immunological parameters, except the increased red blood cell at 2 weeks. Significantly increased antibody titers (p<0.05 against GBS-Ia and GBS-III antigens were noted in the groups immunized with homologous GBS vaccines, whereas the group reacted with heterologous GBS antigen showed less antibody titer as compared with the control group. The vaccination experiment indicated that i.p. injection of Nile tilapia with formalin-killed cells prepared from GBS-Ia or GBS-III provides significant protection, with relative percent survival (RPS value of 52.17 to 71.42%, against a challenge with the homologous serotype isolate, whereas the RPS in fish challenged with a heterologous serotype isolate varied from 20.00 to 53.57%. These results suggested that vaccines from either GBS-Ia or GBS-III have insufficient cross-protective efficacy against the other serotypes. However, a mixed vaccine produced from both GBS serotypes Ia and III provided significant protection with 65.00 to 95.66% RPS which could be an excellent vaccine to protect fish against streptococcosis caused by both GBS serotypes Ia and III.
Smith, Kenneth; Muther, Jennifer J; Duke, Angie L; McKee, Emily; Zheng, Nai-Ying; Wilson, Patrick C; James, Judith A
B lymphocyte memory generates antibody-secreting cells (ASCs) that represent a source of protective antibodies that may be exploited for therapeutics. Here we vaccinated four donors with Pneumovax®23 and produced human monoclonal antibodies (hmAbs) from ASCs. We have cloned 137 hmAbs and the specificities of these antibodies encompass 19 of the 23 serotypes in the vaccine, as well as cell wall polysaccharide (CWPS). Although the majority of the antibodies are serotype specific, 12% cross-react with two serotypes. The Pneumovax®23 ASC antibody sequences are highly mutated and clonal, indicating an anamnestic response, even though this was a primary vaccination. Hmabs from 64% of the clonal families facilitate opsonophagocytosis. Although 9% of the total antibodies bind to CWPS impurity in the vaccine, none of these clonal families showed opsonophagocytic activity. Overall, these studies have allowed us to address unanswered questions in the field of human immune responses to polysaccharide vaccines, including the cross-reactivity of individual antibodies between serotypes and the percentage of antibodies that are protective after vaccination with Pneumovax®23. Copyright © 2012 Elsevier GmbH. All rights reserved.
Harboe, Zitta B; Thomsen, Reimar W; Riis, Anders
BACKGROUND: Pneumococcal disease is a leading cause of morbidity and mortality worldwide. The aim of this study was to investigate the association between specific pneumococcal serotypes and mortality from invasive pneumococcal disease (IPD). METHODS AND FINDINGS: In a nationwide population-based...
Tharwat, Mohamed; Al-Sobayil, Fahd
In goats, contagious caprine pleuropneumonia (CCPP) is a cause of major economic losses in Africa, Asia and in the Middle East. There is no information emphasising the importance of diagnostic ultrasound in goats with CCPP caused by Mycoplasma capricolum subsp. capripneumoniae (Mccp). This study was designed to describe the ultrasonographic findings in goats with CCPP caused by Mccp and to correlate ultrasonographic with post-mortem findings. To this end, 55 goats with CCPP were examined. Twenty-five healthy adult goats were used as a control group. Major clinical findings included harried, painful respiration, dyspnoea and mouth breathing. On ultrasonography, a liver-like echotexture was imaged in 13 goats. Upon post-mortem examination, all 13 goats exhibited unilateral pulmonary consolidation. Seven goats had a unilateral hypoechoic pleural effusion. At necropsy, the related lung was consolidated and the pleural fluid appeared turbid and greenish. Pleural abscessiation detected in five goats was confirmed post-mortem. Twenty-eight goats had a bright, fibrinous matrix extending over the chest wall containing numerous anechoic fluid pockets with medial displacement and compression of lung tissue. Echogenic tags imaged floating in the fluid were found upon post-mortem examination to be fibrin. In two goats, a consolidated right parenchyma was imaged together with hypoechoic pericardial effusions with echogenic tags covering the epicardium. At necropsy, the right lung was consolidated in three goats and fibrin threads were found covering the epicardium and pericardium. In goats with CCPP, the extension and the severity of the pulmonary changes could not be verified with clinical certainty in most cases, whereas this was possible most of the time with sonography, thus making the prognosis easier. Ultrasonographic examination of the pleurae and the lungs helped in the detection of various lesions.
Hillen, Sonja; von Berg, Stephan; Köhler, Kernt; Reinacher, Manfred; Willems, Hermann; Reiner, Gerald
Different vaccination strategies against Mycoplasma hyopneumoniae have been adopted worldwide. Reports from the field indicate varying levels of protection among currently available vaccines. The goal of the present study was to compare the efficacies of three widespread commercial vaccination strategies against M. hyopneumoniae under field conditions. 20 farms were included. 14 farms used different single dose vaccines (vaccine 1 [V1], 8 herds; vaccine 2 [V2], 6 herds); another 6 farms (V3) used a two dose vaccination strategy. Gross lesions of 854 lungs and histopathology from 140 lungs were quantified, and a quantitative PCR was applied to detect M. hyopneumoniae and porcine circovirus 2 (PCV2) DNA in lung tissue (n=140). In addition, porcine reproductive and respiratory disease virus (PRRSV), swine influenza virus (SIV), Actinobacillus pleuropneumoniae, Haemophilus parasuis and Pasteurella multocida were tested by qualitative PCR. 53% of lungs were positive for M. hyopneumoniae. 55.9% of lungs showed macroscopic enzootic pneumonia (EP)-like lesions. Lung lesion scores (Phyopneumoniae-loads (Phyopneumoniae indicating that the applied diagnostic tools are valuable in confirming the prevalence and severity of M. hyopneumoniae infections. Comparing different vaccination strategies against M. hyopneumoniae indicates varying levels of protection. M. hyopneumoniae is still a major problem despite the widely applied vaccination. Copyright © 2014 Elsevier B.V. All rights reserved.
Tereza Cristina A. Leal
Full Text Available Sixteen strains of Yersinia enterocolitica serotype O:3, isolated from apparently healthy pigs collected in Rio de Janeiro, and four human strains of serotypes O:4, O:5, O:6 and O:13 were analyzed by RAPD-PCR. The strains were grouped into five genotypic profiles according to the amplification patterns obtained with three random primers. Fifteen of the 16 pig strains had identical amplification patterns, which was named genotypic profile 1. The one different profile was named genotypic profile 2. Genotypic profile 1 was also exhibited by the O:6 human serotype strain. The O:4 and O:13 human serotype strains showed similar amplification profiles with two primers. However, the third primer induced a distinct profile in each strain. Therefore, these two strains were placed into genotypic profile 3 and 4, respectively. Each primer produced a completely different amplification profile in the O:5 human serotype strain; therefore, it was named genotypic profile 5. The presence or absence of plasmids in the strains studied did not affect the amplification results. These results show that genetic variations can exist within a serotype, and strains of different serotypes can exhibit the same amplification profile when compared using other primers.Foram utilizados três "primers" aleatórios para caracterizar pela técnica RAPD-PCR 16 cepas de Yersinia enterocolitica do sorotipo O:3, isoladas de suínos sadios do Rio de Janeiro. Pelos resultados dos padrões de amplificação, as 16 cepas dos suínos e as 4 cepas humanas usadas como referência (sorotipos O:4, O:5, O:6 e O:13 foram agrupadas em 5 perfis genotípicos. Quinze cepas de suínos apresentaram um padrão de amplificação idêntico (perfil genotípico 1 e somente uma apresentou um perfil de amplificação diferente (perfil genotípico 2. O mesmo padrão de amplificação do perfil genotípico 1 foi também observado em uma cepa humana do sorotipo O:6. As cepas humanas dos sorotipos O:4 e O:13
Martínez-Portilla, R J; López-Velázquez, J L; Martínez-Rojas, G C; Aguilar-Villagómez, M I; De la Torre-Rendón, F E; Villafán-Bernal, J R
Is fundamental to determine the prevalence of human papiloma virus (HVP) high-risk serotypes in local and regional population in order for health providers to offer patients, vaccines and treatments against specific population-based serotypes. To determine the prevalence of HPV High risk serotypes detected by PCR in patients with normal cytology from the ISSSTE Adolfo Lopez Mateos Regional Hospital. An observational, descriptive, prospective study was conducted from cervical cytologies and high risk HPV test by PCR in patients from the Regional Hospital Adolfo López Mateos, ISSSTE, during the period January 2013-December 2015. Cases of patients with negative cervical cytology were included. Information about age, the result of cervical cytology and high risk HPV test by PCR was obtained. The overall prevalence of HPV infection and the most prevalent serotypes by age groups were calculated. A total of 3258 cervical smears were performed, of which 2557 were negative (78.4%), from this, the global prevalence of HPV infection was 10.2% (n=262). We found that 1.8% (n = 45) of negative reports had HPV16 infection, 0.5% (n=13) had HPV18 and 8.9% (n = 227) were infected by Viral Pool of other high-risk serotypes. The prevalence of infection by viral pool of high risk serotypes was 11.5% in women <20 years, 12.9% in women between 20-29 years and 22.2% in women between 30-39 years. This prevalence was lower in patients older than 40 years (p<0.05). A higher prevalence of viral pool high risk serotypes was found in patients with normal cytology, than the HPV16 and HPV-8 prevalence, which was significantly higher in women younger than 40 years.
Full Text Available Focal infection is an uncommon complication of Salmonella septicemia, particularly in immunocompetent patients. The localization of Salmonella infection to breast tissue is regarded as a rare event. We report a case of bilateral breast abscesses due to Salmonella enterica serotype Typhi in a nonlactating female and highlight the fact that Salmonella spp. should be included in differential diagnosis of abscesses in individuals coming from endemic areas with the history of recent typhoid fever and should be treated accordingly.
Lin, Jung-Chung; Koh, Tse Hsien; Lee, Nelson; Fung, Chang-Phone; Chang, Feng-Yee; Tsai, Yu-Kuo; Ip, Margaret; Siu, L Kristopher
In Klebsiella pneumoniae liver abscess (KP-LA), K. pneumoniae K2 is the most frequently isolated serotype after K1, but this serotype has been much less studied. In the present study, the molecular types sequences type (MLST) of serotype K2 isolates from three different regions in Asia were identified and the virulence of these isolates was investigated. Eight different MLSTs were found among 26 isolates (ST 65, 66, 86, 373, 374, 375, 380, and 434). There were two major MLST groups, ST-65-like (42%) and ST86-like (46%). No isolates contained allS while all isolates contained rmpA. The prevalence of aerobactin gene and kfu were 25/26 (96%) and 3/26 (11.5%) respectively. Although liver abscess isolates were generally more resistant (11/15 isolates) to serum killing, there was no specific distribution of serum killing resistant or susceptible ST types between stool carriage and liver abscess isolates. Neutrophil phagocytosis showed that the liver abscess and carriage isolates varied in their susceptibility to phagocytosis. Strains with resistance to both neutrophil phagocytosis and serum killing were generally hypervirulent with lethality at LD50 K2 isolates. Unlike serotype K1 KP-LA that mainly belong to ST-23, ST-65-like and -86-like are the two major MLST types among serotype K2 isolates from Singapore, Hong Kong and Taiwan.
Rocha, Benigno A M; Guilarde, Adriana O; Argolo, Angela F L T; Tassara, Marianna Peres; da Silveira, Lucimeire A; Junqueira, Isabela C; Turchi, Marília D; Féres, Valéria C R; Martelli, Celina M T
Please see Additional file 1 for translations of the abstract into the five official working languages of the United Nations. Currently, in Brazil, there is a co-circulation of the four dengue (DENV-1 to DENV-4) serotypes. This study aimed to assess whether different serotypes and antibody response patterns were associated with the severity of the disease during a dengue outbreak, which occurred in 2012/2013 in centre of Brazil. We conducted a prospective study with 452 patients with laboratory confirmed dengue in central Brazil, from January 2012 to July 2013. The clinical outcome was the severity of cases: dengue, dengue with warning signs, and severe dengue. The patients were evaluated at three different moments. Blood sampling for laboratory testing and confirmatory tests for dengue infection were performed. We performed a multinomial analysis considering the three categories of the dependent variable, as outlined above. The odds ratios (ORs) were calculated. A multinomial logistic regression model was applied for variables with a P-value Brazil. Our findings contribute to the understanding of clinical differences and immune status related to the serotypes DENV-1 and DENV-4 in central of Brazil.
The purpose of this study was to determine the serotypes, genotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing otitis media (OM) in children in Dublin, Ireland. S. pneumoniae isolates (n = 28) from spontaneously discharging OM were studied. Serotyping was performed using a previously undescribed multiplex polymerase chain reaction (PCR) scheme in combination with serological methods. Multilocus sequence typing (MLST) was performed using standard procedures. Antimicrobial susceptibility testing was performed using the Etest method. Fourteen different S. pneumoniae serotypes were identified. The five most common serotypes were 3, 19F, 19A, 14 and 6A, which accounted for 68% of all infections. The 7-valent pneumococcal conjugate vaccine (PCV7), 10-valent pneumococcal conjugate vaccine (PHiD-CV) and 13-valent pneumococcal conjugate vaccine (PCV13) provided potential coverages of 43%, 46% and 86%, respectively. Reduced susceptibility to penicillin was evident for 25% of isolates and was associated with serotypes 14, 19A, 19F and 9V. A total of 21 different sequence types (STs) were identified. Pneumococcal Molecular Epidemiology Network (PMEN) clones or their variants represented 54% (15\\/28) of all isolates. Continued monitoring and characterisation of S. pneumoniae causing OM in Ireland is warranted in order to guide future vaccine and treatment policies.
Davis, A L; Curtis, P A; Conner, D E; McKee, S R; Kerth, L K
Salmonella enterica serotype Enteritidis has long been associated with eggs, and more recently, Salmonella enterica serotype Heidelberg has also become associated with eggs. This study was undertaken to determine whether Salmonella Enteritidis and Salmonella Heidelberg are effectively eliminated from eggs by various cooking methods. Seven cooking methods were chosen--hard and soft cooked, scrambled, over easy, sunny-side up, poached, and free poached--and a pan insert and the free-flowing method were used. Shell eggs, purchased from a grocery store, were inoculated with Salmonella and cooked. The cooked eggs were analyzed by USDA-approved methods for Salmonella recovery. Findings indicated that existing cooking methods for the hard-cooked, soft-cooked, and poaching methods were safe. However, the same was not true for the current sunny-side-up, over-easy, and scrambled egg cooking methods.
Full Text Available Although recombinant adeno-associated virus serotype 3 (AAV3 vectors were largely ignored previously, owing to their poor transduction efficiency in most cells and tissues examined, our initial observation of the selective tropism of AAV3 serotype vectors for human liver cancer cell lines and primary human hepatocytes has led to renewed interest in this serotype. AAV3 vectors and their variants have recently proven to be extremely efficient in targeting human and nonhuman primate hepatocytes in vitro as well as in vivo. In the present studies, we wished to evaluate the relative contributions of the cis-acting inverted terminal repeats (ITRs from AAV3 (ITR3, as well as the trans-acting Rep proteins from AAV3 (Rep3 in the AAV3 vector production and transduction. To this end, we utilized two helper plasmids: pAAVr2c3, which carries rep2 and cap3 genes, and pAAVr3c3, which carries rep3 and cap3 genes. The combined use of AAV3 ITRs, AAV3 Rep proteins, and AAV3 capsids led to the production of recombinant vectors, AAV3-Rep3/ITR3, with up to approximately two to fourfold higher titers than AAV3-Rep2/ITR2 vectors produced using AAV2 ITRs, AAV2 Rep proteins, and AAV3 capsids. We also observed that the transduction efficiency of Rep3/ITR3 AAV3 vectors was approximately fourfold higher than that of Rep2/ITR2 AAV3 vectors in human hepatocellular carcinoma cell lines in vitro. The transduction efficiency of Rep3/ITR3 vectors was increased by ∼10-fold, when AAV3 capsids containing mutations in two surface-exposed residues (serine 663 and threonine 492 were used to generate a S663V+T492V double-mutant AAV3 vector. The Rep3/ITR3 AAV3 vectors also transduced human liver tumors in vivo approximately twofold more efficiently than those generated with Rep2/ITR2. Our data suggest that the transduction efficiency of AAV3 vectors can be significantly improved both using homologous Rep proteins and ITRs as well as by capsid optimization. Thus, the combined use of
A fowl adenovirus serotype 9, a non-pathogenic large double stranded DNA virus, was developed as a viral vector to express influenza genes as a potential vaccine. Two separate constructs were developed that expressed either the hemagglutinin gene of A/Chicken/Jalisco/2012 (H7) or A/ Chicken/Iowa/20...
Dr. Mike Miller reads an abridged version of the Emerging Infectious Diseasesâ study, Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998- 2008. Created: 9/9/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID). Date Released: 9/9/2013.
Raghavendra Sumanth Pudupakam
Full Text Available Aim: Sequence analysis and phylogenetic studies based on non-structural protein-3 (NS3 gene are important in understanding the evolution and epidemiology of bluetongue virus (BTV. This study was aimed at characterizing the NS3 gene sequence of Indian BTV serotype-2 (BTV2 to elucidate its genetic relationship to global BTV isolates. Materials and Methods: The NS3 gene of BTV2 was amplified from infected BHK-21 cell cultures, cloned and subjected to sequence analysis. The generated NS3 gene sequence was compared with the corresponding sequences of different BTV serotypes across the world, and a phylogenetic relationship was established. Results: The NS3 gene of BTV2 showed moderate levels of variability in comparison to different BTV serotypes, with nucleotide sequence identities ranging from 81% to 98%. The region showed high sequence homology of 93-99% at amino acid level with various BTV serotypes. The PPXY/PTAP late domain motifs, glycosylation sites, hydrophobic domains, and the amino acid residues critical for virus-host interactions were conserved in NS3 protein. Phylogenetic analysis revealed that BTV isolates segregate into four topotypes and that the Indian BTV2 in subclade IA is closely related to Asian and Australian origin strains. Conclusion: Analysis of the NS3 gene indicated that Indian BTV2 isolate is closely related to strains from Asia and Australia, suggesting a common origin of infection. Although the pattern of evolution of BTV2 isolate is different from other global isolates, the deduced amino acid sequence of NS3 protein demonstrated high molecular stability.
Pudupakam, Raghavendra Sumanth; Raghunath, Shobana; Pudupakam, Meghanath; Daggupati, Sreenivasulu
Sequence analysis and phylogenetic studies based on non-structural protein-3 (NS3) gene are important in understanding the evolution and epidemiology of bluetongue virus (BTV). This study was aimed at characterizing the NS3 gene sequence of Indian BTV serotype-2 (BTV2) to elucidate its genetic relationship to global BTV isolates. The NS3 gene of BTV2 was amplified from infected BHK-21 cell cultures, cloned and subjected to sequence analysis. The generated NS3 gene sequence was compared with the corresponding sequences of different BTV serotypes across the world, and a phylogenetic relationship was established. The NS3 gene of BTV2 showed moderate levels of variability in comparison to different BTV serotypes, with nucleotide sequence identities ranging from 81% to 98%. The region showed high sequence homology of 93-99% at amino acid level with various BTV serotypes. The PPXY/PTAP late domain motifs, glycosylation sites, hydrophobic domains, and the amino acid residues critical for virus-host interactions were conserved in NS3 protein. Phylogenetic analysis revealed that BTV isolates segregate into four topotypes and that the Indian BTV2 in subclade IA is closely related to Asian and Australian origin strains. Analysis of the NS3 gene indicated that Indian BTV2 isolate is closely related to strains from Asia and Australia, suggesting a common origin of infection. Although the pattern of evolution of BTV2 isolate is different from other global isolates, the deduced amino acid sequence of NS3 protein demonstrated high molecular stability.
Wang, Yun [Center for Food; Fry, H. Christopher [Center for Nanoscale Materials, Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, DuPage County, Illinois 60439, United States; Skinner, Guy E. [Center for Food; Schill, Kristin M. [Center for Food; Duncan, Timothy V. [Center for Food
Botulinum neurotoxin (BoNT) is the most potent toxin known. The ingestion of food contaminated with biologically active BoNT causes foodborne botulism, which can lead to respiratory paralysis, coma, and death after ingestion of as little as 70 mu g for a 70 kg human. Because of its lethality and challenges associated with current detection methods, there is an urgent need for highly sensitive rapid screening techniques capable of detecting biologically active BoNT. Here, we describe a Forster resonance energy transfer-based nanobiosensor that uses quantum dots (QDs) and two specific quencher-labeled peptide probes to detect and differentiate two biologically active forms of BoNT, serotypes A and B, which were responsible for 80% of human foodborne botulism cases in the U.S. from 2012 to 2015. Each peptide probe contains an enzymatic cleavage site specific to only one serotype. QDs were selected based on the spectral overlap with the quenchers. In the presence of the target BoNT serotype, the peptide probe is cleaved and the quenching of QD photoluminescence (PL) is reduced, giving a signal that is easily detected by a PL spectrophotometer. This sensor performance was evaluated with light chains of BoNT/A and BoNT/B (LcA and LcB), catalytic domains of the respective serotypes. LcA and LcB were detected in 3 h with limits of detection of 0.2 and 2 ng/mL, respectively. The specificity of the sensor was evaluated, and no cross-reactivity from nontarget serotypes was observed with 2 h of incubation. Because each serotype-specific peptide is conjugated to a QD with a unique emission wavelength, multiple biologically active BoNT serotypes could be detected in one PL spectrum. The sensor was also shown to be responsive to BoNT/A and BoNT/B holotoxins. Good performance of this sensor implies its potential application as a rapid screening method for biologically active BoNT/A and BoNT/B in the laboratory and in the field.
Fuchs, Jonathan D; Bart, Pierre-Alexandre; Frahm, Nicole; Morgan, Cecilia; Gilbert, Peter B; Kochar, Nidhi; DeRosa, Stephen C; Tomaras, Georgia D; Wagner, Theresa M; Baden, Lindsey R; Koblin, Beryl A; Rouphael, Nadine G; Kalams, Spyros A; Keefer, Michael C; Goepfert, Paul A; Sobieszczyk, Magdalena E; Mayer, Kenneth H; Swann, Edith; Liao, Hua-Xin; Haynes, Barton F; Graham, Barney S; McElrath, M Juliana
Recombinant adenovirus serotype 5 (rAd5)-vectored HIV-1 vaccines have not prevented HIV-1 infection or disease and pre-existing Ad5 neutralizing antibodies may limit the clinical utility of Ad5 vectors globally. Using a rare Ad serotype vector, such as Ad35, may circumvent these issues, but there are few data on the safety and immunogenicity of rAd35 directly compared to rAd5 following human vaccination. HVTN 077 randomized 192 healthy, HIV-uninfected participants into one of four HIV-1 vaccine/placebo groups: rAd35/rAd5, DNA/rAd5, and DNA/rAd35 in Ad5-seronegative persons; and DNA/rAd35 in Ad5-seropositive persons. All vaccines encoded the HIV-1 EnvA antigen. Antibody and T-cell responses were measured 4 weeks post boost immunization. All vaccines were generally well tolerated and similarly immunogenic. As compared to rAd5, rAd35 was equally potent in boosting HIV-1-specific humoral and cellular immunity and responses were not significantly attenuated in those with baseline Ad5 seropositivity. Like DNA, rAd35 efficiently primed rAd5 boosting. All vaccine regimens tested elicited cross-clade antibody responses, including Env V1/V2-specific IgG responses. Vaccine antigen delivery by rAd35 is well-tolerated and immunogenic as a prime to rAd5 immunization and as a boost to prior DNA immunization with the homologous insert. Further development of rAd35-vectored prime-boost vaccine regimens is warranted.
Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo
The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh. Copyright © 2016. Published by Elsevier Ltd.
Ochoa-Gondar, O; Figuerola-Massana, E; Vila-Corcoles, A; Aguirre, C A; de Diego, C; Satue, E; Gomez, F; Raga, X
This study investigated incidence and serotype distribution of Streptococcus pneumoniae causing acute otitis media (AOM) in Catalonian children, evaluating vaccination effectiveness in the current era of extended valency pneumococcal conjugate vaccines (PCVs). Population-based surveillance study that included all AOM cases with isolation of pneumococcus (from otic fluids/otorrea) identified among children ≤14 years in the region of Tarragona (Southern Catalonia, Spain) from 01/01/2007 to 31/12/2013. Prevalence of infections caused by serotypes covered by the different PCVs formulations were calculated for the periods before and after 30/06/2010 (date of PCV7/PCV13 replacement). The indirect cohort method was used to estimate PCV7/13 effectiveness against vaccine-type infections. A total of 78 children with a pneumococcal AOM were identified across study period, which meant an incidence rate of 23 cases per 100,000 population-year. Thirty-six cases (46.2%) occurred within the late PCV7 era and 42 cases (53.8%) during the early PCV13 era. Overall, the most common serotypes were type 19A (21.7%), type 3 (13.3%) and type 15B (6.7%). Prevalence of cases caused by serotypes included in PCV7 did not substantially change between the first and the second study period (from 10.3% to 12.9%), whereas prevalence of cases caused by PCV13 serotypes showed a decreasing trend between both periods (from 65.5% to 48.4%). The aggregate PCV7/13 effectiveness against vaccine-type infections was 72% (95% confidence interval: -26 to 94). Pneumococcal conjugate vaccination appears an acceptable preventive option to prevent pneumococcal AOM in infants. However, its serotype coverage and clinical effectiveness are not optimal. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Das, S; Pingle, M R; Muñoz-Jordán, J; Rundell, M S; Rondini, S; Granger, K; Chang, G-J J; Kelly, E; Spier, E G; Larone, D; Spitzer, E; Barany, F; Golightly, L M
The detection and successful typing of dengue virus (DENV) from patients with suspected dengue fever is important both for the diagnosis of the disease and for the implementation of epidemiologic control measures. A technique for the multiplex detection and typing of DENV serotypes 1 to 4 (DENV-1 to DENV-4) from clinical samples by PCR-ligase detection reaction (LDR) has been developed. A serotype-specific PCR amplifies the regions of genes C and E simultaneously. The two amplicons are targeted in a multiplex LDR, and the resultant fluorescently labeled ligation products are detected on a universal array. The assay was optimized using 38 DENV strains and was evaluated with 350 archived acute-phase serum samples. The sensitivity of the assay was 98.7%, and its specificity was 98.4%, relative to the results of real-time PCR. The detection threshold was 0.017 PFU for DENV-1, 0.004 PFU for DENV-2, 0.8 PFU for DENV-3, and 0.7 PFU for DENV-4. The assay is specific; it does not cross-react with the other flaviviruses tested (West Nile virus, St. Louis encephalitis virus, Japanese encephalitis virus, Kunjin virus, Murray Valley virus, Powassan virus, and yellow fever virus). All but 1 of 26 genotypic variants of DENV serotypes in a global DENV panel from different geographic regions were successfully identified. The PCR-LDR assay is a rapid, sensitive, specific, and high-throughput technique for the simultaneous detection of all four serotypes of DENV.
Lawrence Mark L
Full Text Available Abstract Background Salmonellosis may be a food safety problem when raw food products are mishandled and not fully cooked. In previous work, we developed bioluminescent Salmonella enterica serotypes using a plasmid-based reporting system that can be used for real-time monitoring of the pathogen's growth on food products in short term studies. In this study, we report the use of a Tn7-based transposon system for subcloning of luxCDABE genes into the chromosome of eleven Salmonella enterica serotypes isolated from the broiler production continuum. Results We found that the lux operon is constitutively expressed from the chromosome post-transposition and the lux cassette is stable without external pressure, i.e. antibiotic selection, for all Salmonella enterica serotypes used. Bioluminescence expression is based on an active electron transport chain and is directly related with metabolic activity. This relationship was quantified by measuring bioluminescence against a temperature gradient in aqueous solution using a luminometer. In addition, bioluminescent monitoring of two serotypes confirmed that our chicken skin model has the potential to be used to evaluate pathogen mitigation strategies. Conclusions This study demonstrated that our new stable reporting system eliminates bioluminescence variation due to plasmid instability and provides a reliable real-time experimental system to study application of preventive measures for Salmonella on food products in real-time for both short and long term studies.
Nagano, Noriyuki; Oana, Shinji; Nagano, Yukiko; Arakawa, Yoshichika
Our report highlights a case of severe childhood salmonellosis related to a pet turtle, a red-eared slider (Trachemys scripta elegans). A 6-year-old girl had gastroenteritis complicated with sepsis caused by serotype Paratyphi B, which shared the same pulsed-field gel electrophoresis profiles with the organism isolated from a pet turtle. Based on our literature survey on childhood invasive salmonellosis acquired from reptiles, this case is the first documented reptile-associated salmonellosis including sepsis caused by this serotype.
Full Text Available Background/Aim. Pseudomonas aeruginosa (P. aeruginosa is devided into 20 serotypes on the base of the International Antigenic Typing Scheme. P. aeruginosa serotyping is important because of few reasons but epidemiological is the most important. The aim of the study was serotyping of P. aeruginosa clinical isolates, analysing of single clinical isolates P. aeruginosa present in the particular samples, and analysing of pyocianin and fluorescin production in different isolates of P. aeruginosa. Methods. A total of 223 isolates of P. aeruginosa, isolated in the microbiological laboratory of the Health Center “Aleksinac”, Aleksinac, were examinated. P. aeruginosa isolates were put on the pseudomonas isolation agar, pseudomonas agar base, acetamid agar, asparagin prolin broth, pseudomonas asparagin broth, Bushnnell-Haas agar, cetrimid agar base, King A and King B plates, plates for pyocianin production, plates for fluorescin production and tripticasa soya agar (Himedia. Polyvalent and monovalent serums were used in the agglutination (Biorad. Pigment production was analysed on the bases of growth on the plates for pyocianin and fluorescin production. Results. Serologically, we identificated the serovars as follows: O1, O3, O4, O5, O6, O7, O8, O10, O11 and O12. O1 (38% was the most often serovar, then O11 (19% and O6 (8.6%. A total of 18.6% (42 isolates did not agglutinate with any serum, whereas 21 isolates agglutinated only with polyvalent serum. The majority of P. aeruginosa isolates produced fluorescin, 129 (58.54%, 53 (22.94% produced pyocianin whereas 49 (21.21% isolates produced both pigments. Conclusion. P. aeruginosa was isolated most of the from urine, sputum and other materials. The majority often serovars were O1, O6 and O11. The most of isolates produced fluorescin (58.54%, while 22.94% producted pyocianin and 21.21% both pigments.
Hansen, Vinni; Rosenquist, Hanne; Baggesen, Dorte Lau
range often displayed by phages. To identify the potential of phages as a Campylobacter reducing agent we needed to determine their infectivity on a panel of isolates representing the Campylobacter strains found in broilers as well as humans. Results: In this study, Campylobacter phages were isolated...... from the intestines of broilers and ducks and from abattoir sewage. Twelve phages were investigated to determine their ability to infect the Campylobacter Penner serotypes commonly present in Danish poultry and patients with campylobacteriosis. A total of 89% of the Campylobacter jejuni strains and 14...... range of 12 Danish Campylobacter phages. Due to their ability to infect the majority of the common serotypes in Denmark we suggest the phages can become an effective agent in the effort to reduce the incidence of campylobacteriosis in Denmark. This study provides the basis for future experiments...
Aouaj, Y.; Spanjaard, L.; van Leeuwen, N.; Dankert, J.
Two hundred and seven cases of listeria meningitis that occurred in The Netherlands over 20 years were reviewed to study associations between Listeria monocytogenes serotype, age, underlying disease, and outcome. The mean annual incidence per 100000 population was 0.12 in 1981-90, decreasing to 0.07
Full Text Available The aim of this study was to determine the serotype and clonal distribution of pneumococci causing acute otitis media (AOM and their relationship with recurrences and mixed infections with other microorganisms under the influence of the 7-valent pneumococcal conjugate vaccine (PCV7. To do this, all pneumococcal isolates collected from the spontaneous middle-ear drainage of children <5 years old diagnosed of AOM by their pediatrician or their general practitioner from 1999 to 2010 were phenotypically characterized and the most frequent serotypes were genotyped. In the 12-year study, 818 episodes of pneumococcal AOM were detected, mostly (70.5% in children younger than 2 years old. In 262 episodes (32%, the pneumococci were isolated with another bacterium, mainly (n=214 Haemophilus influenzae. Mixed infections were similar in children under or over 2 years old. The most frequent serotypes were 19A (n=227, 27.8%, 3 (n=92, 11.2% and 19F (n=74, 9%. Serotypes included in the PCV7 sharply decreased from 62.4% in the pre-vaccination (1999-2001 to 2.2% in the late post-vaccination period (2008-2010. Serotype diversity steadily increased after the introduction of the PCV7 but decreased from 2008-2010 due to the predominant role of serotype 19A isolates, mostly ST276 and ST320. The prevalence of serotype 3 doubled from 6.1% (20/326 in 1999-2004 to 14.6% (72/492 in 2005-2010. Relapses mainly occurred in male infants infected with isolates with diminished antimicrobial susceptibility. Reinfections caused by isolates with the same serotype but different genotype were frequent, highlighting the need for genetic studies to differentiate among similar strains. In conclusion, the main change in pneumococcal AOM observed after the introduction of the PCV7 was the sharp decrease in vaccine serotypes. Also notable was the high burden of serotype 19A in total pneumococcal AOM before and especially after the introduction of the PCV7, as well as in relapses and
Fenlon, D R
Of 1241 samples of seagulls faeces examined, 12.9% were found to contain salmonellae. The number of positive samples was significantly higher (17-21%) near sewage outfalls. Twenty-seven serotypes were isolated, including a new serotype named Salmonella grampian. The range and frequency of serotypes carried by gulls was similar to those in the human population, suggesting sewage as a possible source of gull infection. The number of salmonellae found in positive samples was low (0.18-191 g-1 faeces). This was similar to the numbers found in sewage, 10-80 1-1, suggesting gulls may only carry infected material without infecting themselves. Antibiotic resistance in the isolates was low, only 21 showing resistance to the antibiotics tested, although most of these were determined by resistance transfer plasmids.
Larry H. Stanker
Full Text Available Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT, produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A–H have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD’s for individual antibodies ranging from 10 to 48 × 10−11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D., ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule and readily detects toxin in those food samples tested.
Stanker, Larry H; Scotcher, Miles C; Cheng, Luisa; Ching, Kathryn; McGarvey, Jeffery; Hodge, David; Hnasko, Robert
Botulism is a serious foodborne neuroparalytic disease, caused by botulinum neurotoxin (BoNT), produced by the anaerobic bacterium Clostridium botulinum. Seven toxin serotypes (A-H) have been described. The majority of human cases of botulism are caused by serotypes A and B followed by E and F. We report here a group of serotype B specific monoclonal antibodies (mAbs) capable of binding toxin under physiological conditions. Thus, they serve as capture antibodies for a sandwich (capture) ELISA. The antibodies were generated using recombinant peptide fragments corresponding to the receptor-binding domain of the toxin heavy chain as immunogen. Their binding properties suggest that they bind a complex epitope with dissociation constants (KD's) for individual antibodies ranging from 10 to 48 × 10-11 M. Assay performance for all possible combinations of capture-detector antibody pairs was evaluated and the antibody pair resulting in the lowest level of detection (L.O.D.), ~20 pg/mL was determined. Toxin was detected in spiked dairy samples with good recoveries at concentrations as low as 0.5 pg/mL and in ground beef samples at levels as low as 2 ng/g. Thus, the sandwich ELISA described here uses mAb for both the capture and detector antibodies (binding different epitopes on the toxin molecule) and readily detects toxin in those food samples tested.
Huhtamo, E; Korhonen, Em; Vapalahti, O
Imported dengue cases originating from the Madeiran outbreak are increasingly reported. In 2012 five Finnish travellers returning from Madeira were diagnosed with dengue fever. Viral sequence data was obtained from two patients. The partial C-preM sequences (399 and 396 bp respectively) were found similar to that of an autochthonous case from Madeira. The partial E-gene sequence (933 bp) which was identical among the two patients grouped phylogenetically with South American strains of dengue virus serotype 1.
Full Text Available Background: Uropathogenic Escherichia coli (UPEC O-serogroups with their phylogenetic background are the most prevalent causes of urinary tract infections (UTIs. Objectives: The association of O types with phylogenetic background was assessed among E. coli isolates collected from patients with UTI. Patients and Methods: In this study, 186 patients with UTI, referred to two hospitals affiliated to Zabol University of Medical Sciences in southeast of Iran, were enrolled during January to July 2013. Phylogenetic groups and serotyping were performed using multiplex-PCR method. Results: A total of 100 E. coli strains were isolated from the urine samples. The most common types of O antigens were O2 (16.43%, O6 (16.43% and O18 (13.69%. The phylogenetic analysis showed that 63 O-antigen-positive isolates were mainly segregated from the phylogenetic group B2 (56% and the substantial prevalence (30% belonged to the phylogenetic group D. Conclusions: This was the first report of E. coli serotyping in patient with UTI from southeast of Iran as well as investigation of their relation with phylogenetic pattern by multiplex-PCR. Further studies from other parts of Iran and on other serotypes are recommended.
Mwiine, F.N.; Ayebazibwe, C.; Olaho-Mukani, W.
Uganda had an unusually large number of foot-and-mouth disease (FMD) outbreaks in 2006, and all clinical reports were in cattle. A serological investigation was carried out to confirm circulating antibodies against foot-and-mouth disease virus (FMDV) by ELISA for antibodies against non-structural......Uganda had an unusually large number of foot-and-mouth disease (FMD) outbreaks in 2006, and all clinical reports were in cattle. A serological investigation was carried out to confirm circulating antibodies against foot-and-mouth disease virus (FMDV) by ELISA for antibodies against non......-structural proteins and structural proteins. Three hundred and forty-nine cattle sera were collected from seven districts in Uganda, and 65% of these were found positive for antibodies against the non-structural proteins of FMDV. A subset of these samples were analysed for serotype specificity of the identified...... antibodies. High prevalences of antibodies against non-structural proteins and structural proteins of FMDV serotype O were demonstrated in herds with typical visible clinical signs of FMD, while prevalences were low in herds without clinical signs of FMD. Antibody titres were higher against serotype O than...
Syrogiannopoulos, G A; Doit, C; Grivea, I N; Geslin, P; Bingen, E
In January 1996 the emergence of penicillin-susceptible, multiresistant serotype 6B Streptococcus pneumoniae isolates resistant to chloramphenicol, tetracycline, erythromycin, clindamycin and trimethoprim-sulfamethoxazole was observed in young carriers in the city of Patras, located in the southwestern region of Greece. Later, a significant spread of pneumococci with this unusual phenotype was noted in carriers living in various other areas of the country. Using restriction fragment length polymorphism of the ribosomal RNA genes, clonal relationships were found between these Greek strains and serotype 6B penicillin-susceptible, multiresistant pneumococci isolated in France between January 1992 and September 1996. The French and Greek isolates appear to have a common ancestry.
Namatovu, Alice; Tjørnehøj, Kirsten; Belsham, Graham
To investigate the foot-and-mouth disease virus (FMDV) serotypes circulating in Uganda’s cattle population, both serological and virological analyses of samples from outbreaks that occurred during 2012-2013 were performed. Altogether, 79 sera and 60 oropharyngeal fluid (OP)/tissue/oral swab samples...... were collected from herds with reported FMD outbreaks in seven different Ugandan districts. Overall, 61/79 (77%) of the cattle sera were positive for antibodies against FMDV by PrioCHECK® FMDV NS ELISA and solid phase blocking ELISA detected titres ≥ 80 for serotypes O, SAT 1, SAT 2 and SAT 3 in 41, 45...... Kiruhura, Isingiro and Ntungamo districts. Consistent with the detection of high levels of neutralising antibodies against SAT 2, was the isolation of a SAT 2 FMDV from Isingiro; sequencing (for the VP1 coding region) indicated that this virus belonged to lineage I within this serotype, like the currently...
Full Text Available Serotype, mating type and ploidy of 84 strains of Cryptococcus neoformans isolated from 61 AIDS and 23 non-AIDS patients admitted in a tertiary teaching hospital in São Paulo, Brazil were examined. Among 61 strains isolated from AIDS patients, 60 strains were var. grubii (serotype A. Only one strain was var. gattii (serotype B. No var. neoformans (serotype D was found. Among 23 strains isolated from non-AIDS patients, 15 were var. grubii (serotype A and the remaining 8 were var. gattii, all of which were serotype B. Seventy-three of the 75 serotype A strains were the heterothallic alpha type (MATalpha and the remaining 2 were untypable (asexual. Most of the MATalpha strains (69/73 were haploid and the remaining 4 strains were diploid. Similarly, both of the 2 asexual strains among the 75 serotype A strains were haploid. There were no alpha-mating type (MATalpha strains among the 84 isolates. All of the 8 var. gattii strains were serotype B and haploid. Among a total of 84 strains tested, neither serotype AD nor serotype D were found. Neither triploid nor tetraploid were found. These results suggest that the serological, sexual and ploidy characteristics in C. neoformans strains isolated from AIDS patients in São Paulo were rather simple, whereas strains isolated from non-AIDS patients presented serotype A and B with predominance of serotype A.Foram estudados os sorotipos, "mating type" e ploidia de 84 amostras de C. neoformans isoladas de 61 pacientes com AIDS e 23 não-AIDS em São Paulo. Das amostras isoladas de pacientes com AIDS, 60 foram identificadas como var. grubii (sorotipo A e 1 como var. gattii (sorotipo B. Não houve isolamento do sorotipo D. Entre as amostras isoladas, de pacientes não-AIDS, 15 foram de var. grubii (sorotipo A e as 8 restantes de var. gattii, todos do sorotipo B. Setenta e três dos 75 sorotipos A foram identificadas como cepas heterotálicas do fenótipo alfa (MATalfa e as 2 remanescentes n
Deng, Xiangyu; Desai, Prerak T.; den Bakker, Henk C.
serotype Nitra strains. Single-nucleotide polymorphisms were filtered to identify 4,887 reliable loci that distinguished all isolates from each other. Our whole-genome single-nucleotide polymorphism typing approach was robust for S. enterica Enteritidis subtyping with combined data for different strains...
Background: Culicoides sonorensis (Diptera: Ceratopogonidae) is a vector of epizootic hemorrhagic disease virus (EHDV) serotypes 1 and 2 in North America, where these viruses are well-known pathogens of white-tailed deer (WTD) and other wild ruminants. Although historically rare, reports of clinica...
Abhirosh, C; Sherin, V; Thomas, A P; Hatha, A A M; Mazumder, A
To assess the prevalence of faecal coliform bacteria and multiple drug resistance among Escherichia coli and Salmonella serotypes from Vembanadu Lake. Systematic microbiological testing. Monthly collection of water samples were made from ten stations on the southern and northern parts of a salt water regulator constructed in Vembanadu Lake in order to prevent incursion of seawater during certain periods of the year. Density of faecal colifrom bacteria was estimated. E. coli and Salmonella were isolated and their different serotypes were identified. Antibiotic resistance analysis of E. coli and Salmonella serotypes was done and the MAR index of individual isolates was calculated. Density of faecal coliform bacteria ranged from mean MPN value 2900 -7100/100ml. Results showed multiple drug resistance pattern among the bacterial isolates. E. coli showed more than 50% resistance to amickacin, oxytetracycline, streptomycin, tetracycline and kanamycin while Salmonella showed high resistance to oxytetracycline, streptomycin, tetracycline and ampicillin. The MAR indexing of the isolates showed that they have originated from high risk source such as humans, poultry and dairy cows. The high density of faecal coliform bacteria and prevalence of multi drug resistant E. coli and Salmonella serotypes in the lake may pose severe public health risk through related water borne and food borne outbreaks. Copyright © 2011 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Reid, Scott M; Mioulet, Valerie; Knowles, Nick J; Shirazi, Nazeem; Belsham, Graham J; King, Donald P
Rapid and accurate diagnosis is essential for effective control of foot-and-mouth disease (FMD). In countries where FMD is endemic, identification of the serotypes of the causative virus strains is important for vaccine selection and tracing the source of outbreaks. In this study, real-time reverse transcription polymerase chain reaction (rRT-PCR) assays using primer/probe sets designed from the VP1 coding region of the virus genomes were developed for the specific detection of serotype O, A and Asia-1 FMD viruses (FMDVs) circulating in the Middle East. These assays were evaluated using representative field samples of serotype O strains belonging exclusively to the PanAsia-2 lineage, serotype A strains of the Iran-05 lineage and serotype Asia-1 viruses from three relevant sub-groups. When RNA extracted from archival and contemporary field strains was tested using one- or two-step rRT-PCR assays, all three primer/probe sets detected the RNA from homotypic viruses and no cross-reactivity was observed with heterotypic viruses. Similar results were obtained using both single- and multiplex assay formats. Using plasmid standards, the minimum detection level of these tests was found to be lower than two copies. The results illustrate the potential of tailored rRT-PCR tools for the detection and categorization of viruses circulating in the Middle East belonging to distinct subgroups of serotypes O, A and Asia-1. These assays can also overcome the problem of serotyping samples which are found positive by the generic rRT-PCR diagnostic assays but negative by virus isolation and antigen-detection ELISA which would otherwise have to be serotyped by nucleotide sequencing. A similar approach could be used to develop serotyping assays for FMDV strains circulating in other regions of the world. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.
Kimura, Keiji Richard; Nakata, Masanobu; Sumitomo, Tomoko; Kreikemeyer, Bernd; Podbielski, Andreas; Terao, Yutaka; Kawabata, Shigetada
The group A streptococcus (GAS) Streptococcus pyogenes is known to cause self-limiting purulent infections in humans. The role of GAS pili in host cell adhesion and biofilm formation is likely fundamental in early colonization. Pilus genes are found in the FCT (fibronectin-binding protein, collagen-binding protein, and trypsin-resistant antigen) genomic region, which has been classified into nine subtypes based on the diversity of gene content and nucleotide sequence. Several epidemiological studies have indicated that FCT type 1 strains, including serotype M6, produce large amounts of monospecies biofilm in vitro. We examined the direct involvement of pili in biofilm formation by serotype M6 clinical isolates. In the majority of tested strains, deletion of the tee6 gene encoding pilus shaft protein T6 compromised the ability to form biofilm on an abiotic surface. Deletion of the fctX and srtB genes, which encode pilus ancillary protein and class C pilus-associated sortase, respectively, also decreased biofilm formation by a representative strain. Unexpectedly, these mutant strains showed increased bacterial aggregation compared with that of the wild-type strain. When the entire FCT type 1 pilus region was ectopically expressed in serotype M1 strain SF370, biofilm formation was promoted and autoaggregation was inhibited. These findings indicate that assembled FCT type 1 pili contribute to biofilm formation and also function as attenuators of bacterial aggregation. Taken together, our results show the potential role of FCT type 1 pili in the pathogenesis of GAS infections.
Sparding, Nadja; Dayie, Nicholas Tete Kwaku Dzifa; Mills, Richael O.
Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Pneumococcal strains are classified according to their capsular polysaccharide and more than 90 different serotypes are currently known. In this project, three distinct groups of pneumococcal carriage isolates from Gh...... in Ghana in that many new clones were identified. This supports the importance of continued monitoring of pneumococcal carriage in Ghana and elsewhere when vaccines, e.g., PCV-13, have been introduced to monitor the possible future spread of antimicrobial resistant clones....
M.H. Chew; M.M. Rahman; J. Jelip; M.R. Hassan; I. Isahak
Dengue is a severe disease caused by dengue virus (DENV), transmitted to human being by infected Aedes mosquitoes. It is a major public health concern in Southeast Asia due to its fatality in the form of hemorrhagic fever (DHF) and dengue shock syndrome (DSS). The objective of the study was to isolate and identify dengue virus serotypes prevalent in endemic areas of Kuala Lumpur and Selangor in Malaysia by virus culture, indirect immunoflurecent assay and molecular techniques. A total number ...
Hood, M A; Ness, G E; Rodrick, G E
Two strains of Vibrio cholerae serotype O1 Inaba were isolated from eastern oysters, Crassostrea virginica, collected from estuarine waters in Florida during April 1980. The oyster meats and waters from which the oysters were collected had low fecal coliform counts, and the area had no prior evidence of sewage contamination. PMID:7235700
Full Text Available Abstract Background Infections due to nontyphoidal Salmonella have increased worldwide over the last couple of decades. Salmonella enterica serotype Blockley (Salmonella Blockley infections is associated with chickens and is a rarely isolated serotype in human infections in most countries. Case presentation We report a case of human infections due to Salmonella Blockley in KwaZulu-Natal, South Africa in 2011. Three African males (aged 4, 14 and 16 presented to a clinic with diarrhoea, stomach cramps and headache. They started experiencing signs of illness a day after they consumed a common meal, consisting of meat, rice and potatoes. Stool specimens from the patients cultured Salmonella Blockley. The strains showed an indistinguishable pulsed-field gel electrophoresis pattern. Conclusion This is the first recorded case of human infections due to Salmonella Blockley in South Africa.
Schaake, Julia; Kronshage, Malte; Uliczka, Frank; Rohde, Manfred; Knuuti, Tobias; Strauch, Eckhard; Fruth, Angelika; Wos-Oxley, Melissa
Yersinia enterocolitica is a human pathogen that is ubiquitous in livestock, especially pigs. The bacteria are able to colonize the intestinal tract of a variety of mammalian hosts, but the severity of induced gut-associated diseases (yersiniosis) differs significantly between hosts. To gain more information about the individual virulence determinants that contribute to colonization and induction of immune responses in different hosts, we analyzed and compared the interactions of different human- and animal-derived isolates of serotypes O:3, O:5,27, O:8, and O:9 with murine, porcine, and human intestinal cells and macrophages. The examined strains exhibited significant serotype-specific cell binding and entry characteristics, but adhesion and uptake into different host cells were not host specific and were independent of the source of the isolate. In contrast, survival and replication within macrophages and the induced proinflammatory response differed between murine, porcine, and human macrophages, suggesting a host-specific immune response. In fact, similar levels of the proinflammatory cytokine macrophage inflammatory protein 2 (MIP-2) were secreted by murine bone marrow-derived macrophages with all tested isolates, but the equivalent interleukin-8 (IL-8) response of porcine bone marrow-derived macrophages was strongly serotype specific and considerably lower in O:3 than in O:8 strains. In addition, all tested Y. enterocolitica strains caused a considerably higher level of secretion of the anti-inflammatory cytokine IL-10 by porcine than by murine macrophages. This could contribute to limiting the severity of the infection (in particular of serotype O:3 strains) in pigs, which are the primary reservoir of Y. enterocolitica strains pathogenic to humans. PMID:23959720
This study was designed to evaluate hyperspectral microscope images for early and rapid detection of Salmonella serotypes: S. Enteritidis, S. Heidelberg, S. Infantis, S. Kentucky, and S. Typhimurium at incubation times of 6, 8, 10, 12, and 24 hours. Images were collected by an acousto-optical tunab...
Yuan Zong Hui
Full Text Available Salmonella spp. can indirectly infect humans via transfer from animals and animal-derived food products, and thereby cause potentially fatal diseases. Therefore, gaining an understanding of Salmonella infection in farm animals is increasingly important. The aim of this study was to identify the distribution of serotypes in Salmonella samples isolated from chickens (n = 837, pigs (n = 930, and dairy cows (n = 418 in central China (Henan, Hubei, and Hunan provinces in 2010–2011, and investigate the susceptibility of strains to antimicrobial agents. Salmonella isolates were identified by PCR amplification of the invA gene, serotypes were determined by using a slide agglutination test for O and H antigens, and susceptibility to 24 antimicrobials was tested using the agar dilution method. In total, 248 Salmonella strains were identified: 105, 105, and 38 from chickens, dairy cows, and pigs, respectively. Additionally, 209 strains were identified in unhealthy pigs from the Huazhong Agricultural University veterinary hospital. Among these 457 strains, the dominant serotypes were Typhimurium in serogroup B, IIIb in serogroup C, and Enteritidis in serogroup D. In antimicrobial susceptibility tests, 41.14% of Salmonella spp. were susceptible to all antimicrobial agents, 48.14% were resistant to at least one, and 34.72% were resistant to more than three classes. Strains were highly resistant to sulfamethoxazole-trimethoprim (39.61%, nalidixic acid (39.17%, doxycycline (28.22%, and tetracycline (27.58%. Resistance to cephalosporins and fluoroquinolones ranged from 5.25% to 7.44% and 19.04% to 24.51%, respectively. Among penicillin-resistant and cephalosporin-resistant strains, 25 isolates produced extended-spectrum β-lactamases (ESBLs. The multidrug-resistant and ESBL-producing Salmonella strains identified in healthy animals here will present a challenge for veterinary medicine and farm animal husbandry, and could also pose a threat to public health
Chiávetta, L; Chávez, E; Ruzic, A; Mollerach, M; Regueira, M
Neisseria meningitidis is an important cause of meningitis, bacteremia and septic shock syndrome. We herein present the distribution of serogroups, serotypes and serosubtypes of 2244 isolates of N. meningitidis from patients with meningitis or meningococcemia, received within the period 1993-2005, in the National Reference Laboratory, INEI-ANLIS "Dr. Carlos G. Malbrán", from 33 Argentine hospitals that are included in a National Network devoted to for the study of bacterial meningitis. Between 1993-1995, serogroup B was prevalent (66%) whereas in the period from 1995-2001, serogroup C prevailed (65%). However, following but after that period, the prevalence of serogroup B was recovered. In the last 5 years of the studied period, the serogroups Y and W135 represented as a whole a 15.6% as a whole whereas up to the year 2000 during the first 6 years they accounted for it was of 4.7%. Higher diversity in the distribution of serotypes and serosubtypes was observed within serogroup B. The nonsubtypable isolates throughout the period of study represented the 52.8%, this high percentage demonstrates the limited capacity of the serotyping for the determination of meningococcal/meningococcus subtypes. of meningococco.
Full Text Available Streptococcus suis infection is a severe zoonotic disease commonly found in Northern Thailand where people often consume raw pork and/or pig’s blood. The most frequent clinical presentations are meningitis, sepsis, and endocarditis with higher rate of mortality and hearing loss sequelae. To clarify the correlation between pulsed-field gel electrophoresis (PFGE groups and mrp/epf/sly genotypes of S. suis serotype 2, 62 patient and 4 healthy pig isolates from Northern Thailand were studied. By PFGE analysis, at 66% homology, most human isolates (69.4% and 1 pig isolate were in group A, whereas 14.5% of human isolates and 3 out of 4 pig isolates were in group D. According to mrp/epf/sly genotypes, 80.6% of human isolates were identified in mrp+epf−sly− and only 12.9% were in mrp−epf−sly+ genotypes; in contrast, 1 and 3 pig isolates were detected in these two genotypes, respectively. Interestingly, all isolates of S. suis serotype 2 classified in PFGE groups A, B, and E were set in mrp+epf−sly− genotypes. These data show a close correlation between PFGE groups and mrp/epf/sly genotypes of human S. suis serotype 2.
Tharavichitkul, Prasit; Wongsawan, Kanreuthai; Takenami, Naoki; Pruksakorn, Sumalee; Fongcom, Achara; Gottschalk, Marcelo; Khanthawa, Banyong; Supajatura, Volaluk; Takai, Shinji
Streptococcus suis infection is a severe zoonotic disease commonly found in Northern Thailand where people often consume raw pork and/or pig's blood. The most frequent clinical presentations are meningitis, sepsis, and endocarditis with higher rate of mortality and hearing loss sequelae. To clarify the correlation between pulsed-field gel electrophoresis (PFGE) groups and mrp/epf/sly genotypes of S. suis serotype 2, 62 patient and 4 healthy pig isolates from Northern Thailand were studied. By PFGE analysis, at 66% homology, most human isolates (69.4%) and 1 pig isolate were in group A, whereas 14.5% of human isolates and 3 out of 4 pig isolates were in group D. According to mrp/epf/sly genotypes, 80.6% of human isolates were identified in mrp (+) epf (-) sly (-) and only 12.9% were in mrp (-) epf (-) sly (+) genotypes; in contrast, 1 and 3 pig isolates were detected in these two genotypes, respectively. Interestingly, all isolates of S. suis serotype 2 classified in PFGE groups A, B, and E were set in mrp (+) epf (-) sly (-) genotypes. These data show a close correlation between PFGE groups and mrp/epf/sly genotypes of human S. suis serotype 2.
Tian, Huaiyu; Sun, Zhe; Faria, Nuno Rodrigues; Yang, Jing; Cazelles, Bernard; Huang, Shanqian; Xu, Bo; Yang, Qiqi; Pybus, Oliver G; Xu, Bing
The incidence of dengue has grown dramatically in recent decades worldwide, especially in Southeast Asia and the Americas with substantial transmission in 2014-2015. Yet the mechanisms underlying the spatio-temporal circulation of dengue virus (DENV) serotypes at large geographical scales remain elusive. Here we investigate the co-circulation in Asia of DENV serotypes 1-3 from 1956 to 2015, using a statistical framework that jointly estimates migration history and quantifies potential predictors of viral spatial diffusion, including socio-economic, air transportation and maritime mobility data. We find that the spread of DENV-1, -2 and -3 lineages in Asia is significantly associated with air traffic. Our analyses suggest the network centrality of air traffic hubs such as Thailand and India contribute to seeding dengue epidemics, whilst China, Cambodia, Indonesia, and Singapore may establish viral diffusion links with multiple countries in Asia. Phylogeographic reconstructions help to explain how growing air transportation networks could influence the dynamics of DENV circulation.
Full Text Available The incidence of dengue has grown dramatically in recent decades worldwide, especially in Southeast Asia and the Americas with substantial transmission in 2014-2015. Yet the mechanisms underlying the spatio-temporal circulation of dengue virus (DENV serotypes at large geographical scales remain elusive. Here we investigate the co-circulation in Asia of DENV serotypes 1-3 from 1956 to 2015, using a statistical framework that jointly estimates migration history and quantifies potential predictors of viral spatial diffusion, including socio-economic, air transportation and maritime mobility data. We find that the spread of DENV-1, -2 and -3 lineages in Asia is significantly associated with air traffic. Our analyses suggest the network centrality of air traffic hubs such as Thailand and India contribute to seeding dengue epidemics, whilst China, Cambodia, Indonesia, and Singapore may establish viral diffusion links with multiple countries in Asia. Phylogeographic reconstructions help to explain how growing air transportation networks could influence the dynamics of DENV circulation.
Antony, B; Dias, M; Shetty, A K; Rekha, B
An outbreak of food poisoning due to Salmonella enterica serotype Weltevreden ( S.weltevreden ) involving 34 students has been reported from a tertiary care hospital in Mangalore. The symptoms developed 8-10 hours, after consuming a non- vegetarian dish, probably fish, from an outside caterer. The identity of the organism was confirmed at Central Research Institute, Kasauli. This report emphasizes the geographical distribution of this organism in the Coastal Karnataka region. S.Weltevreden may be overlooked due to the biochemical similarity to S. Paratyphi B & S. Typhimurium.
Shashkova, Elena V.; May, Shannon M.; Barry, Michael A.
Human adenovirus type 5 (Ad5) has been the most popular platform for the development of oncolytic Ads. Alternative Ad serotypes with low seroprevalence might allow for improved anticancer efficacy in Ad5-immune patients. We studied the safety and efficacy of rare serotypes Ad6, Ad11 and Ad35. In vitro cytotoxicity of the Ads correlated with expression of CAR and CD46 in most but not all cell lines. Among CAR-binding viruses, Ad5 was often more active than Ad6, among CD46-binding viruses Ad35 was generally more cytotoxic than Ad11 in cell culture studies. Ad5, Ad6, and Ad11 demonstrated similar anticancer activity in vivo, whereas Ad35 was not efficacious. Hepatotoxicity developed only in Ad5-injected mice. Predosing with Ad11 and Ad35 did not increase infection of hepatocytes with Ad5-based vector demonstrating different interaction of these Ads with Kupffer cells. Data obtained in this study suggest developing Ad6 and Ad11 as alternative Ads for anticancer treatment.
Eichmann, Klaus; Krause, Richard M
During the first decade of the twentieth century, the German bacteriologist Fred Neufeld, later Director of the Robert Koch-Institute in Berlin, first described the differentiation of pneumococci into serotypes on the basis of type-specific antisera. This finding was essential for subsequent research at the Rockefeller Institute of Medical Research (RIMR) in New York, and elsewhere, aiming for the conquest of human pneumococcal pneumonia, including antiserum therapy, the discovery that the type-specific antigens were carbohydrates, and the development of effective multivalent pneumococcal polysaccharide vaccines. Moreover, on the basis of pneumococcal serotypes Fred Griffith, in 1928 in London, discovered pneumococcal transformation, and Oswald T. Avery and coworkers, in 1944 at RIMR, identified DNA as the transforming substance. This sequence of events, leading to today's knowledge that genes consist of DNA, was initiated by a farsighted move of Simon Flexner, first Director of the RIMR, who asked Neufeld to send his pneumococcal typing strains, thus setting the stage for pneumococcal research at RIMR. Here, we describe Fred Neufeld's contributions in this development, which have remained largely unknown.
Fong, K P; Chung, W O; Lamont, R J; Demuth, D R
The cell density-dependent control of gene expression is employed by many bacteria for regulating a variety of physiological functions, including the generation of bioluminescence, sporulation, formation of biofilms, and the expression of virulence factors. Although periodontal organisms do not appear to secrete acyl-homoserine lactone signals, several species, e.g., Porphyromonas gingivalis, Prevotella intermedia, and Fusobacterium nucleatum, have recently been shown to secrete a signal related to the autoinducer II (AI-2) of the signal system 2 pathway in Vibrio harveyi. Here, we report that the periodontal pathogen Actinobacillus actinomycetemcomitans expresses a homolog of V. harveyi luxS and secretes an AI-2-like signal. Cell-free conditioned medium from A. actinomycetemcomitans or from a recombinant Escherichia coli strain (E. coli AIS) expressing A. actinomycetemcomitans luxS induced luminescence in V. harveyi BB170 >200-fold over controls. AI-2 levels peaked in mid-exponential-phase cultures of A. actinomycetemcomitans and were significantly reduced in late-log- and stationary-phase cultures. Incubation of early-log-phase A. actinomycetemcomitans cells with conditioned medium from A. actinomycetemcomitans or from E. coli AIS resulted in a threefold induction of leukotoxic activity and a concomitant increase in leukotoxin polypeptide. In contrast, no increase in leukotoxin expression occurred when cells were exposed to sterile medium or to conditioned broth from E. coli AIS(-), a recombinant strain in which luxS was insertionally inactivated. A. actinomycetemcomitans AI-2 also induced expression of afuA, encoding a periplasmic iron transport protein, approximately eightfold, suggesting that LuxS-dependent signaling may play a role in the regulation of iron acquisition by A. actinomycetemcomitans. Finally, A. actinomycetemcomitans AI-2 added in trans complemented a luxS knockout mutation in P. gingivalis by modulating the expression of the lux
Spencer, Brady L.; Shenoy, Anukul T.; Orihuela, Carlos J.; Nahm, Moon H.
As a species, Streptococcus pneumoniae (the pneumococcus) utilizes a diverse array of capsular polysaccharides to evade the host. In contrast to large variations in sugar composition and linkage formation, O-acetylation is a subtle capsular modification that nonetheless has a large impact on capsular shielding and recognition of the capsule by vaccine-elicited antibodies. Serotype 15B, which is included in the 23-valent pneumococcal polysaccharide vaccine (PPV23), carries the putative O-acety...
Dobbs, Fred C; Goodrich, Amanda L; Thomson, Frank K; Hynes, Wayne
There is concern that ships' ballasting operations may disseminate Vibrio cholerae to ports throughout the world. Given evidence that the bacterium is indeed transported by ships, we isolated pandemic serotypes O1 and O139 from ballast tanks and characterized them with respect to antibiotic resistance and virulence genes ctxA and tcpA. We carried out concurrent studies with V. cholerae isolated from coastal waters. Of 284 isolates, 30 were serotype O1 and 59 were serotype O139. These serotypes were overrepresented in ballast tanks relative to the coastal waters sampled. All locations, whether coastal waters or ballast tanks, yielded samples from which serotype O1, O139, or both were isolated. There were three groups among the 62 isolates for which antibiotic characterization was conclusive: those exhibiting β-lactamase activity and resistance to at least one of the 12 antibiotics tested; those negative for β-lactamase but having antibiotic resistance; those negative for β-lactamase and registering no antibiotic resistance. When present, antibiotic resistance in nearly all cases was to ampicillin; resistance to multiple antibiotics was uncommon. PCR assays revealed that none of the isolates contained the ctxA gene and only two isolates, one O139 and one O1, contained the tcpA gene; both isolates originated from ballast water. These results support the bacteriological regulations proposed by the International Maritime Association for discharged ballast water.
Lee, Hyunju; Lim, Soo Young; Kim, Kyung Hyo
The World Health Organization (WHO) enzyme-linked immunosorbent assay (ELISA) guideline is currently accepted as the gold standard for the evaluation of immunoglobulin G (IgG) antibodies specific to pneumococcal capsular polysaccharide. We conducted validation of the WHO ELISA for 7 pneumococcal serotypes (4, 6B, 9V, 14, 18C, 19F, and 23F) by evaluating its specificity, precision (reproducibility and intermediate precision), accuracy, spiking recovery test, lower limit of quantification (LLOQ), and stability at the Ewha Center for Vaccine Evaluation and Study, Seoul, Korea. We found that the specificity, reproducibility, and intermediate precision were within acceptance ranges (reproducibility, coefficient of variability [CV] ≤ 15%; intermediate precision, CV ≤ 20%) for all serotypes. Comparisons between the provisional assignments of calibration sera and the results from this laboratory showed a high correlation > 94% for all 7 serotypes, supporting the accuracy of the ELISA. The spiking recovery test also fell within an acceptable range. The quantification limit, calculated using the LLOQ, for each of the serotypes was 0.05-0.093 μg/mL. The freeze-thaw stability and the short-term temperature stability were also within an acceptable range. In conclusion, we showed good performance using the standardized WHO ELISA for the evaluation of serotype-specific anti-pneumococcal IgG antibodies; the WHO ELISA can evaluate the immune response against pneumococcal vaccines with consistency and accuracy. © 2017 The Korean Academy of Medical Sciences.
Sangula, Abraham K.; Belsham, Graham; Muwanika, Vincent B.
Background: In East Africa, foot-and-mouth disease virus serotype SAT 1 is responsible for occasional severe outbreaks in livestock and is known to be maintained within the buffalo populations. Little is known about the evolutionary forces underlying its epidemiology in the region. To enhance our...... 1 FMD viruses from East Africa has been determined and compared with known sequences derived from other SAT 1 viruses from sub-Saharan Africa. Purifying (negative) selection and low substitution rates characterized the SAT 1 virus isolates in East Africa. Two virus groups with probable independent...... appreciation of the epidemiological status of serotype SAT 1 virus in the region, we inferred its evolutionary and phylogeographic history by means of genealogy-based coalescent methods using 53 VP1 coding sequences covering a sampling period from 1948-2007. Results: The VP1 coding sequence of 11 serotype SAT...
Full Text Available Recombinant, replication-deficient serotype 5 adenovirus infects the liver upon in vivo, systemic injection in rodents. This infection requires the binding of factor X to the capsid of this adenovirus. Another organ, the adrenal gland is also infected upon systemic administration of Ad, however, whether this infection is dependent on the cocksackie adenovirus receptor (CAR or depends on the binding of factor X to the viral capsid remained to be determined. In the present work, we have used a pharmacological agent (warfarin as well as recombinant adenoviruses lacking the binding site of Factor X to elucidate this mechanism in mice. We demonstrate that, as observed in the liver, adenovirus infection of the adrenal glands in vivo requires Factor X. Considering that the level of transduction of the adrenal glands is well-below that of the liver and that capsid-modified adenoviruses are unlikely to selectively infect the adrenal glands, we have used single-photon emission computed tomography (SPECT imaging of gene expression to determine whether local virus administration (direct injection in the kidney could increase gene transfer to the adrenal glands. We demonstrate that direct injection of the virus in the kidney increases gene transfer in the adrenal gland but liver transduction remains important. These observations strongly suggest that serotype 5 adenovirus uses a similar mechanism to infect liver and adrenal gland and that selective transgene expression in the latter is more likely to be achieved through transcriptional targeting.
Amat, S; Subramanian, S; Timsit, E; Alexander, T W
This study evaluated the potential of probiotic bacteria to inhibit growth and cell adhesion of the bovine respiratory pathogen Mannheimia haemoltyica serotype 1. The inhibitory effects of nine probiotic strains (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus plantarum, Lactobacillus rhamnosus, Lactococcus lactis, Streptococcus thermophilus and two Paenibacillus polymyxa strains) against M. haemolytica were evaluated using a spot-on-lawn method. Probiotic strains were then tested for their adherence to bovine bronchial epithelial (BBE) cells and the ability to displace and compete against M. haemolytica on BBE. Except for S. thermophilus, all probiotic strains inhibited the growth of M. haemolytica, with zones of inhibition ranging between 12 and 19 mm. Lactobacillus strains and Lactococcus lactis displayed greater (P probiotics (probiotics. The results of this study suggest that probiotics may have the potential to colonize the bovine respiratory tract, and exert antagonistic effects against M. haemolytica serotype 1. A common method to control bovine respiratory disease (BRD) in feedlots is through mass medication with antibiotics upon cattle entry (i.e. metaphylaxis). Increasingly, antimicrobial resistance in BRD bacterial pathogens has been observed in feedlots, which may have important implications for cattle health. In this study, probiotic strains were shown to adhere to bovine respiratory cells and inhibit the BRD pathogen M. haemolytica serotype 1 through competition and displacement. Probiotics may therefore offer a mitigation strategy to reduce BRD bacterial pathogens, in place of metaphylactic antimicrobials. © 2017 Her Majesty the Queen in Right of Canada Letters in Applied Microbiology © 2017 The Society for Applied Microbiology Reproduced with the permission of the Minister of Agriculture and Agri-Food Canada.
DETECTION AND TRANSMISSION OF EXTRACELLULAR FACTOR PRODUCING STREPTOCOCCUS SUIS SEROTYPE 2 STRAINS IN PIGS INTRODUCTION Streptococcus suis (S.suis) has been implicated in the etiology of many diseases among which meningitis in pigs. The virulent extracellular factor-positive strains of S.suis
Nielsen, Eva M.; Engberg, J.; Fussing, V.
The stability of four typing methods and the sero- and genotypic stability of three Campylobacter jejuni strains were evaluated after subculturing 50 times in triplicate and after colonising mice for up to 26 days. The employed methods were Penner heat-stable serotyping; automated ribotyping (Ribo......Printing) using HaeIII restriction enzyme; pulsed-field gel electrophoresis (PFGE) using SmaI, SalI and KpnI; and random amplified polymorphic DNA analysis (RAPD) using primers 1254, 1281 and HLWL85. No changes in any of the DNA profiles or in the reactions to heat-stable antigens were identified among...... these strains after the in vitro and in vivo passages. However, one isolate became untypeable with RAPD after passage in one of the mice. In addition, eleven other C. jejuni strains of four different serotypes were subcultured ten times to screen for instability. Neither of these showed instability using PFGE...
Full Text Available An outbreak of food poisoning due to Salmonella enterica serotype Weltevreden ( S.weltevreden involving 34 students has been reported from a tertiary care hospital in Mangalore. The symptoms developed 8-10 hours, after consuming a non- vegetarian dish, probably fish, from an outside caterer. The identity of the organism was confirmed at Central Research Institute, Kasauli. This report emphasizes the geographical distribution of this organism in the Coastal Karnataka region. S.Weltevreden may be overlooked due to the biochemical similarity to S. Paratyphi B & S. Typhimurium.
Jamal, Syed Muhammad; Ferrari, Giancarlo; Ahmed, Safia
Foot-and-mouth disease (FMD) is endemic in Pakistan and Afghanistan; serotypes O, A and Asia-1 of the virus are responsible for the outbreaks in these countries with FMDV type O usually being the most common. In the present study, the nucleotide sequences encoding the FMDV capsid protein VP1 from...... in the region were found to be 6.65×10−3 (95% CI=5.49–7.80×10−3) and 7.80×10−3 (95% CI=6.72–8.89×10−3) substitutions per nucleotide per year, respectively. The present study reveals the presence of multiple (sub-)lineages of FMDV serotype O co-circulating in the region and that significant new variants...
Sluijs, van der M.; Timmermans, M.; Moulin, V.; Vonk Noordegraaf, C.; Vrijenhoek, M.; Debyser, I.; Smit, de A.J.; Moormann, R.J.M.
The ability of Bluetongue virus serotype 8 (BTV-8) originating from the 2006 European outbreak to cross the ovine placenta during early and mid gestation was investigated in two separate experiments. In the first experiment, 16 ewes were infected with BTV-8 at 70–75 days gestation. The foetuses were
Hammer, Anne Sofie; Pedersen, Karl; Andersen, Thomas Holmen
Isolates of Pseudomonas aeruginosa from clinical infections in mink were subjected to serotyping and pulsed-field gel electrophoresis (PFGE) using SpeI. A total of 212 isolates of P aeruginosa from the year 1998 to 2001 were included in this study: 168 isolates from mink obtained from 74 farm out...
Benschop, K. S. M.; Schinkel, J.; Minnaar, R. P.; Pajkrt, D.; Spanjerberg, L.; Kraakman, H. C.; Berkhout, B.; Zaaijer, H. L.; Beld, M. G. H. M.; Wolthers, K. C.
Background. Human parechoviruses (HPeVs) are members of the family Picornaviridae and are classified into 3 known serotypes: HPeV1, HPeV2, and the recently identified HPeV3. HPeV1 and HPeV2 infections are most commonly associated with mild respiratory or gastrointestinal symptoms and occasionally
Full Text Available A total of 150 purified isolates of Pasteurella multocida serotype B were used (Salmah, 2004 for plasmid DNA curing experiment to determine hyaluronidase activity, antibiotic resistance pattern (ARP and mice lethality test (LD50 for their role of pathogenicity. A plasmid curing experiment was carried out by using the intercalating agent; ethidium bromide and rifampicin, where it was found all the plasmids had been cured (plasmidless from Pasteurella multocida. All of these plasmidless isolates maintained their phenotypic characteristics. They showed the same antibiotic resistancepattern as before curing, produced hyaluronidase and possessed lethality activity in mice when injected intraperitoneally(i.p. Based on this observation, the antibiotic resistance, hyaluronidase activity and mice virulence could probably be chromosomal-mediated. Plasmids were detected 100% in all P. multocida isolates with identical profile of 2 plasmids size 3.0 and 5.5 kb. No large plasmids could be detected in all isolates. Since all the isolates appeared to have identicalplasmid profiles, they were subjected to restriction enzyme(RE analysis. From RE analysis results obtained, it can be concluded that the plasmid DNA in serotype B isolates are identical. Only 4 of 32 REs were found to cleave these plasmids with identical restriction fingerprints; BglII, HaeIII, RsaI and SspI. From RE analysis results, it can be concluded that the plasmid DNA isolates are identical. This plasmid might not played any role in pathogenicity of Pasteurella multocida serotype B, however this information is important for the construction of shuttle vectors in genetic studies of the pathogenicity of haemorrhagic septicaemia(HS.
Hanazawa, S; Sagiya, T; Amano, S; Nishikawa, H; Kitano, S
Recent studies have demonstrated the presence of three serotypes (O1K1, O1K2, and O1K-) of Porphyromonas (Bacteroides) endodontalis. In the present study, a hybridoma cell line producing monoclonal antibody (BEE11) specific for serotype O1K1 of P. endodontalis was established. The specificity of the antibody was evaluated by enzyme-linked immunosorbent assay and immunoslot blot analysis. BEE11 antibody reacted with strains ATCC 35406, HG 400, and HG 421 of the bacterium. However, it did not react with HG 422 or HG 948. Also, the antibody did not react with any of the black-pigmented Bacteroides strains tested. Although the antibody reacted with total cell envelope and capsule materials, it did not do so with lipopolysaccharide. The antibody reacted with antigen material having a molecular mass of 110 kilodaltons (kDa), as judged from fractionation by Superose 12 prep gel chromatography. When the peak fraction from the Superose 12 column was subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot (immunoblot) analysis, the reactivity was detected as a single band at an apparent molecular mass of about 52 kDa. The antigen material purified partially by high-performance liquid chromatography was sensitive to trypsin, V8 protease, and heating to 80 degrees C but not to neuraminidase. Therefore, the present study shows that BEE11 antibody recognizes a serotype antigen of P. endodontalis which may be a dimer consisting of monomers having molecular masses of approximately 52 kDa and sensitivity to proteases and heat. Images PMID:2370106
Lotfollahi, Lida; Chaharbalesh, Ardalan; Ahangarzadeh Rezaee, Mohammad; Hasani, Alka
Listeria monocytogenes is a foodborne pathogen causing listeriosis, which potentially affects all individuals, especially pregnant women and immunocompromised persons. The present study investigated the prevalence, antimicrobial susceptibility and serotypes distribution of the isolated L. monocytogenes from Iran. Twenty two (4.97%) of 442 human, food and livestock samples were found to be positive for L. monocytogenes. L. monocytogenes was identified in 8.8% of 125 human samples, 2.99% of 267 food and 6% of 50 livestock samples. The standard disk diffusion method and minimum inhibitory concentration (MIC) assay were used for antimicrobial susceptibility testing and multiplex PCR for serotyping. Among the 22 isolates tested, 6 (27.2%) displayed resistance to penicillin G, with all of the isolates and 2 (9%) of them showing intermediate susceptibility to clindamycin and rifampicin, respectively. According to the MIC assay, the rate of resistance to penicillin G was the same as that of disk diffusion method, but 16 (72.7%) of isolates showed intermediate susceptibility to clindamycin using E-test. In the multiplex PCR, 19 (86.4%) of isolates belonged to serotype 1/2c or 3c and the remaining 3 isolates were identified as (4b, 4d or 4e) and (1/2a or 3a), respectively. The occurrence of resistance to penicillin G, which can be used in the treatment of listeriosis, is very alarming and more prevalence of 1/2c serotype, in comparison to 3 other important ones (1/2a, 1/2b and 4b), in Iran has been reported for the first time. To the best of our knowledge, this is the first study showing the distribution of various serogroups of L. monocytogenes from human and livestock in Iran. Copyright © 2017 Elsevier Ltd. All rights reserved.
Siu, L Kristopher; Tsai, Yu-Kuo; Lin, Jung-Chung; Chen, Te-Li; Fung, Chang-Phone; Chang, Feng-Yee
In this study, a novel colloidal gold-based immunochromatographic strip (ICS) containing anti-Klebsiella pneumoniae capsular polysaccharide polyclonal antibodies was developed to specifically detect K. pneumoniae serotypes K1 and K2. Capsular polysaccharide K1 and K2 antigens were first used to produce polyclonal anti-K1 and anti-K2 antibodies. Reference strains with different serotypes, nontypeable K. pneumoniae strains, and other bacterial species were then used to assess the sensitivity and specificity of these test strips. The detection limit was found to be 10 5 CFU, and the ICSs were stable for 6 months when stored at room temperature. No false-positive or false-negative results were observed, and equivalent results were obtained compared to those of more conventional test methods, such as PCR or serum agglutination. In conclusion, the ICS developed here requires no technical expertise and allows for the specific, rapid, and simultaneous detection of K. pneumoniae serotypes K1 and K2. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Vernal, Rolando; León, Rubén; Silva, Augusto; van Winkelhoff, Arie J; Garcia-Sanz, Jose A; Sanz, Mariano
AIM: Capsular polysaccharides play an important role in the virulence of Gram-positive and Gram-negative bacteria. In Porphyromonas gingivalis, six serotypes have been described based on capsular antigenicity and its pathogenicity has been correlated both in vitro and in animal models. This study
Introduction: Swine are the only known animal reservoir of Yersinia enterocolitica (YE), a human pathogen. Since YE is a fecal organism of swine, the primary goal of this study was to evaluate the prevalence, serotype, virulence plasmid (pYV)-associated characteristics, clonality, and antibiotic su...
Bari, Fufa Dawo; Parida, Satya; Asfor, Amin S.; Haydon, Daniel T.; Reeve, Richard; Paton, David J.
Epitopes on the surface of the foot-and-mouth disease virus (FMDV) capsid have been identified by monoclonal antibody (mAb) escape mutant studies leading to the designation of four antigenic sites in serotype A FMDV. Previous work focused on viruses isolated mainly from Asia, Europe and Latin America. In this study we report on the prediction of epitopes in African serotype A FMDVs and testing of selected epitopes using reverse genetics. Twenty-four capsid amino acid residues were predicted to be of antigenic significance by analysing the capsid sequences (n = 56) using in silico methods, and six residues by correlating capsid sequence with serum–virus neutralization data. The predicted residues were distributed on the surface-exposed capsid regions, VP1–VP3. The significance of residue changes at eight of the predicted epitopes was tested by site-directed mutagenesis using a cDNA clone resulting in the generation of 12 mutant viruses involving seven sites. The effect of the amino acid substitutions on the antigenic nature of the virus was assessed by virus neutralization (VN) test. Mutations at four different positions, namely VP1-43, VP1-45, VP2-191 and VP3-132, led to significant reduction in VN titre (P value = 0.05, 0.05, 0.001 and 0.05, respectively). This is the first time, to our knowledge, that the antigenic regions encompassing amino acids VP1-43 to -45 (equivalent to antigenic site 3 in serotype O), VP2-191 and VP3-132 have been predicted as epitopes and evaluated serologically for serotype A FMDVs. This identifies novel capsid epitopes of recently circulating serotype A FMDVs in East Africa. PMID:25614587
Bentley, L; Fehrsen, J; Jordaan, F; Huismans, H; du Plessis, D H
VP2 is an outer capsid protein of African horsesickness virus (AHSV) and is recognized by serotype-discriminatory neutralizing antibodies. With the objective of locating its antigenic regions, a filamentous phage library was constructed that displayed peptides derived from the fragmentation of a cDNA copy of the gene encoding VP2. Peptides ranging in size from approximately 30 to 100 amino acids were fused with pIII, the attachment protein of the display vector, fUSE2. To ensure maximum diversity, the final library consisted of three sub-libraries. The first utilized enzymatically fragmented DNA encoding only the VP2 gene, the second included plasmid sequences, while the third included a PCR step designed to allow different peptide-encoding sequences to recombine before ligation into the vector. The resulting composite library was subjected to immunoaffinity selection with AHSV-specific polyclonal chicken IgY, polyclonal horse immunoglobulins and a monoclonal antibody (MAb) known to neutralize AHSV. Antigenic peptides were located by sequencing the DNA of phages bound by the antibodies. Most antigenic determinants capable of being mapped by this method were located in the N-terminal half of VP2. Important binding areas were mapped with high resolution by identifying the minimum overlapping areas of the selected peptides. The MAb was also used to screen a random 17-mer epitope library. Sequences that may be part of a discontinuous neutralization epitope were identified. The amino acid sequences of the antigenic regions on VP2 of serotype 3 were compared with corresponding regions on three other serotypes, revealing regions with the potential to discriminate AHSV serotypes serologically.
González Morales, N L; Núñez-López, M; Ramos-Castañeda, J; Velasco-Hernández, J X
In this work we present a mathematical model that incorporates two Dengue serotypes. The model has been constructed to study both the epidemiological trends of the disease and conditions that allow coexistence in competing strains under vaccination. We consider two viral strains and temporary cross-immunity with one vector mosquito population. Results suggest that vaccination scenarios will not only reduce disease incidence but will also modify the transmission dynamics. Indeed, vaccination and cross immunity period are seen to decrease the frequency and magnitude of outbreaks but in a differentiated manner with specific effects depending upon the interaction vaccine and strain type. Copyright © 2016 Elsevier Inc. All rights reserved.
Goraichuk, Iryna; Sharma, Poonam; Stegniy, Borys; Muzyka, Denys; Pantin-Jackwood, Mary J.; Gerilovych, Anton; Solodiankin, Olexii; Bolotin, Vitaliy; Miller, Patti J.; Dimitrov, Kiril M.; Afonso, Claudio L.
Here, we report the complete genome sequence of a virus of a putative new serotype of avian paramyxovirus (APMV). The virus was isolated from a white-fronted goose in Ukraine in 2011 and designated white-fronted goose/Ukraine/Askania-Nova/48-15-02/2011. The genomic characterization of the isolate suggests that it represents the novel avian paramyxovirus group APMV 13.
Goraichuk, Iryna; Sharma, Poonam; Stegniy, Borys; Muzyka, Denys; Pantin-Jackwood, Mary J.; Gerilovych, Anton; Solodiankin, Olexii; Bolotin, Vitaliy; Miller, Patti J.; Dimitrov, Kiril M.
Here, we report the complete genome sequence of a virus of a putative new serotype of avian paramyxovirus (APMV). The virus was isolated from a white-fronted goose in Ukraine in 2011 and designated white-fronted goose/Ukraine/Askania-Nova/48-15-02/2011. The genomic characterization of the isolate suggests that it represents the novel avian paramyxovirus group APMV 13. PMID:27469958
Dhikusooka, Moses Tefula; Tjørnehøj, Kirsten; Ayebazibwe, Chrisostom
After a 16-year interval, foot-and-mouth disease virus serotype SAT 3 was isolated in 2013 from an apparently healthy long-horned Ankole calf that grazed close to buffalo in Uganda. The emergent virus strain is ≈20% different in nucleotide sequence (encoding VP1 [viral protein 1]) from its closest...
A Stx2a-producing Escherichia coli (STEC) strain belonging to serotype O104:H4, with virulence features common to the enteroaggregative E. coli pathotype, was reported as the cause of the recent 2011 outbreak in Germany. In addition, the German outbreak strain was found to possess several virulence factors of extra-intestinal pathogenic E. coli and to have acquired resistance to numerous antibiotics, including third-generation cephalosporins, owing to several plasmid-borne genes encoding TEM-1 and CTX-M-15 β-lactamases. There are only a few reports of serotype O104:H4, which is very rare in humans, and has never been detected in animals or food. Once the serotype of the German outbreak strain became known, specific molecular methods were developed for its detection based on conventional and real-time PCR. Data from Galicia suggest that, per year in Spain, STEC O157:H7 is responsible for more than 500 cases of infection, and non-O157 for more than 2,000. A microbiological diagnosis for O104:H4, O157:H7 and other STEC serotypes is required in Spanish hospitals. Copyright © 2011 Elsevier España, S.L. All rights reserved.
Ganeshnarayan, Krishnaraj; Shah, Suhagi M; Libera, Matthew R; Santostefano, Anthony; Kaplan, Jeffrey B
Biofilms are composed of bacterial cells encased in a self-synthesized, extracellular polymeric matrix. Poly-beta(1,6)-N-acetyl-d-glucosamine (PNAG) is a major biofilm matrix component in phylogenetically diverse bacteria. In this study we investigated the physical and chemical properties of the PNAG matrix in biofilms produced in vitro by the gram-negative porcine respiratory pathogen Actinobacillus pleuropneumoniae and the gram-positive device-associated pathogen Staphylococcus epidermidis. The effect of PNAG on bulk fluid flow was determined by measuring the rate of fluid convection through biofilms cultured in centrifugal filter devices. The rate of fluid convection was significantly higher in biofilms cultured in the presence of the PNAG-degrading enzyme dispersin B than in biofilms cultured without the enzyme, indicating that PNAG decreases bulk fluid flow. PNAG also blocked transport of the quaternary ammonium compound cetylpyridinium chloride (CPC) through the biofilms. Binding of CPC to biofilms further impeded fluid convection and blocked transport of the azo dye Allura red. Bioactive CPC was efficiently eluted from biofilms by treatment with 1 M sodium chloride. Taken together, these findings suggest that CPC reacts directly with the PNAG matrix and alters its physical and chemical properties. Our results indicate that PNAG plays an important role in controlling the physiological state of biofilms and may contribute to additional biofilm-associated processes such as biocide resistance.
Greene, Nicholas P; Crow, Allister; Hughes, Colin; Koronakis, Vassilis
Secreted pore-forming toxins of pathogenic Gram-negative bacteria such as Escherichia coli hemolysin (HlyA) insert into host-cell membranes to subvert signal transduction and induce apoptosis and cell lysis. Unusually, these toxins are synthesized in an inactive form that requires posttranslational activation in the bacterial cytosol. We have previously shown that the activation mechanism is an acylation event directed by a specialized acyl-transferase that uses acyl carrier protein (ACP) to covalently link fatty acids, via an amide bond, to specific internal lysine residues of the protoxin. We now reveal the 2.15-Å resolution X-ray structure of the 172-aa ApxC, a toxin-activating acyl-transferase (TAAT) from pathogenic Actinobacillus pleuropneumoniae. This determination shows that bacterial TAATs are a structurally homologous family that, despite indiscernible sequence similarity, form a distinct branch of the Gcn5-like N-acetyl transferase (GNAT) superfamily of enzymes that typically use acyl-CoA to modify diverse bacterial, archaeal, and eukaryotic substrates. A combination of structural analysis, small angle X-ray scattering, mutagenesis, and cross-linking defined the solution state of TAATs, with intermonomer interactions mediated by an N-terminal α-helix. Superposition of ApxC with substrate-bound GNATs, and assay of toxin activation and binding of acyl-ACP and protoxin peptide substrates by mutated ApxC variants, indicates the enzyme active site to be a deep surface groove.
Pérez-Castro, Rosalía; Castellanos, Jaime E; Olano, Víctor A; Matiz, María Inés; Jaramillo, Juan F; Vargas, Sandra L; Sarmiento, Diana M; Stenström, Thor Axel; Overgaard, Hans J
The Aedes aegypti vector for dengue virus (DENV) has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50%) and DENV-1 (35%). Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.
Full Text Available The Aedes aegypti vector for dengue virus (DENV has been reported in urban and periurban areas. The information about DENV circulation in mosquitoes in Colombian rural areas is limited, so we aimed to evaluate the presence of DENV in Ae. aegypti females caught in rural locations of two Colombian municipalities, Anapoima and La Mesa. Mosquitoes from 497 rural households in 44 different rural settlements were collected. Pools of about 20 Ae. aegypti females were processed for DENV serotype detection. DENV in mosquitoes was detected in 74% of the analysed settlements with a pool positivity rate of 62%. The estimated individual mosquito infection rate was 4.12% and the minimum infection rate was 33.3/1,000 mosquitoes. All four serotypes were detected; the most frequent being DENV-2 (50% and DENV-1 (35%. Two-three serotypes were detected simultaneously in separate pools. This is the first report on the co-occurrence of natural DENV infection of mosquitoes in Colombian rural areas. The findings are important for understanding dengue transmission and planning control strategies. A potential latent virus reservoir in rural areas could spill over to urban areas during population movements. Detecting DENV in wild-caught adult mosquitoes should be included in the development of dengue epidemic forecasting models.
Toro, Magaly; Cao, Guojie; Ju, Wenting; Allard, Marc; Barrangou, Rodolphe; Zhao, Shaohua; Brown, Eric; Meng, Jianghong
Shiga toxin-producing Escherichia coli (STEC) strains (n = 194) representing 43 serotypes and E. coli K-12 were examined for clustered regularly interspaced short palindromic repeat (CRISPR) arrays to study genetic relatedness among STEC serotypes. A subset of the strains (n = 81) was further analyzed for subtype I-E cas and virulence genes to determine a possible association of CRISPR elements with potential virulence. Four types of CRISPR arrays were identified. CRISPR1 and CRISPR2 were present in all strains tested; 1 strain also had both CRISPR3 and CRISPR4, whereas 193 strains displayed a short, combined array, CRISPR3-4. A total of 3,353 spacers were identified, representing 528 distinct spacers. The average length of a spacer was 32 bp. Approximately one-half of the spacers (54%) were unique and found mostly in strains of less common serotypes. Overall, CRISPR spacer contents correlated well with STEC serotypes, and identical arrays were shared between strains with the same H type (O26:H11, O103:H11, and O111:H11). There was no association identified between the presence of subtype I-E cas and virulence genes, but the total number of spacers had a negative correlation with potential pathogenicity (P CRISPR-cas system and potential virulence needs to be determined on a broader scale, and the biological link will need to be established.
Jamal, Syed Muhammad; Ferrari, Giancarlo; Ahmed, Safia
Foot-and-mouth disease (FMD) is endemic in Pakistan and Afghanistan. The FMD virus serotypes O, A and Asia-1 are responsible for the outbreaks in these countries. Diverse strains of FMDV, even within the same serotype, co-circulate. Characterization of the viruses in circulation can facilitate...... appropriate vaccine selection and tracing of outbreaks.The present study characterized foot-and-mouth disease serotype Asia-1 viruses circulating in Pakistan and Afghanistan during the period 1998–2009. Phylogenetic analysis of FMDV type Asia-1 revealed that three different genetic Groups of serotype Asia-1...... of the A-Iran05AFG-07 sub-lineage. The Asia-1 FMDVs currently circulating in Pakistan and Afghanistan are not efficiently neutralized by antisera raised against the Asia-1/Shamir vaccine strain. Thus, new Asia-1 vaccine strains may be required to block the spread of the current Asia-1 viruses....
Nimfa Maria Stojek
Full Text Available Experts are anxious because “American serotype” Yersinia entorocolitica O:8 unexpectedly appeared in Europe in the years 2000 because of its high pathogenicity. The aim of the investigations was to determine people risk contact with different serotypes of Yersinia, based on serological investigations in the years 1997–99 in relation to current epidemiological situation. The study covered 573 sera, from 300 healthy persons and 157 suspicious of yersiniosis, and 116 suspicious of other zoonosis. Tests were performed by passive hemaglutination reaction with antigens viewed as pathogenic to humans Y. enterocolitica O:3, O:5, O:6, O:8, O:9 and Y. pseudotuberculosis group I and III. The most frequently detected antibodies were anti-Y.e. O:5 (41,2% and then anti-Y.e. O:8 (36,6%, anti-Y.e. O;3 (20,1%, anti-Y.e. O;6 (9,2%, anti-Y.e. O:9 (4,6% and anti-Y. pseudotuberculosis I i III (11,8% and 10,3%. The results of investigations show, that already in the years 1997–1999 over 30% of population had contact with Yersinia sticks, including serotypes thought as pathogenic: Y. enterocolitica O:3 (20,1 %, Y. enterocolitica O:9 (4,6 % and particularly with Y. enterocolitica O:8 (36,6 %.
Petersen, A.; Aarestrup, Frank Møller; Angulo, F. J.
% of the results were correct. For susceptibility testing, 92% of the results were in agreement with the expected results. However, only 78% of the performed tests with the E. coli ATCC 25922 reference strain were within the quality control range specified by National Committee for Clinical Laboratory Standards...... susceptibility testing through international training courses and an External Quality Assurance System (EQAS). In 2000, 44 WHO Global Salm-Surv member laboratories from 35 countries determined the serotype and antimicrobial susceptibility pattern for eight "blinded" Salmonella isolates. For serotyping, 73...... (NCCLS) guidelines. These EQAS results demonstrate the need for further training to improve the performance of some of the laboratories. WHO Global Salm-Surv activities, including international training courses and EQAS, represent an important step toward improving the quality of Salmonella serotyping...
Hirai, Nobuyasu; Kasahara, Kei; Uno, Kenji; Ogawa, Yoshihiko; Ogawa, Taku; Yonekawa, Shinsuke; Nakano, Ryuichi; Yano, Hisakazu; Sakagami, Azusa; Uemura, Takayuki; Okura, Hiroyuki; Saito, Yoshihiko; Yoshikawa, Masahide; Mikasa, Keiichi
An increasing number of invasive infections due to Streptococcus agalactiae in non-pregnant adults have been reported. We report a case of infective endocarditis complicated by intraventricular abscesses, pericarditis, and mycotic aneurysm due to S. agalactiae belonging to ST681 with a capsular serotype VI in a woman with diabetes. The patient also had a myocardial infarction and was treated with percutaneous coronary intervention, pericardiocentesis, and 6 weeks of antibiotic treatment. Invasive infections due to serotype VI S. agalactiae are common in Asian countries such as Taiwan and Japan, so continuous monitoring of invasive S. agalactiae strains is warranted.
Jamal, Syed M; Ferrari, Giancarlo; Ahmed, Safia; Normann, Preben; Belsham, Graham J
Foot-and-mouth disease (FMD) is endemic in Pakistan and Afghanistan. The FMD virus serotypes O, A and Asia-1 are responsible for the outbreaks in these countries. Diverse strains of FMDV, even within the same serotype, co-circulate. Characterization of the viruses in circulation can facilitate appropriate vaccine selection and tracing of outbreaks. The present study characterized foot-and-mouth disease serotype Asia-1 viruses circulating in Pakistan and Afghanistan during the period 1998-2009. Phylogenetic analysis of FMDV type Asia-1 revealed that three different genetic Groups of serotype Asia-1 have circulated in Pakistan during this time. These are Group-II, -VI and, recently, a novel Group (designated here as Group-VII). This new Group has not been detected in neighbouring Afghanistan during the study period but viruses from Groups I and -II are in circulation there. Using near complete genome sequences, from FMD viruses of serotypes Asia-1 and A that are currently circulating in Pakistan, we have identified an interserotypic recombinant virus, which has the VP2-VP3-VP1-2A coding sequences derived from a Group-VII Asia-1 virus and the remainder of the genome from a serotype A virus of the A-Iran05(AFG-07) sub-lineage. The Asia-1 FMDVs currently circulating in Pakistan and Afghanistan are not efficiently neutralized by antisera raised against the Asia-1/Shamir vaccine strain. Thus, new Asia-1 vaccine strains may be required to block the spread of the current Asia-1 viruses. Copyright © 2011 Elsevier B.V. All rights reserved.
Kawaguchiya, Mitsuyo; Urushibara, Noriko; Kobayashi, Nobumichi
Since the implementation of routine PCV13 immunization in Japan, nonvaccine serotypes (NVTs) have been increasing among clinical isolates of Streptococcus pneumoniae. In this study, susceptibility to 18 antibiotics was tested for all the 231 isolates with NVTs, which were collected from children Japan in 2014 (July-November). High resistance rates were observed for macrolides (>90.9%), tetracycline (91.3%), and clindamycin (75.3%), while penicillin (PEN) nonsusceptibility (PNSP; MIC ≥0.12 μg/ml) was detected in 42.9% of the pneumococci [39.4%; PEN-intermediate S. pneumoniae (PISP), 3.5%; PEN-resistant S. pneumoniae (PRSP)]. All serotype 15A isolates were PRSP (MIC, ≥2 μg/ml) or PISP, and PNSP was prevalent in also serotypes 23A (96.9%), 6C (41%), and 35B (33.3%). Overall, 42.0% of the isolates showed multidrug resistance (MDR). Sequence types (STs) determined for 20 PNSP isolates with NVTs were ST63 (15A), STs 242 or 5832 (6C), STs 338 or 5242 (23A), and ST558 (35B). All the PNSP isolates possessed tet(M), and erm(B) or mefA(A/E), and 70% of them were gPRSP having three altered genes pbp1a, pbp2x, and pbp2b. Among alterations in transpeptidase-coding region of penicillin-binding proteins (PBPs), two substitutions of T 371 S in the STMK motif and TSQF 574-577 NTGY in PBP1a were common to all PRSP isolates. The present study showed the spread of PNSP in NVTs 15A, 23A, 6C, and 35B, and the emergence of the MDR international clone Sweden 15A -ST63 in northern Japan.
S F Swedan
Full Text Available Aims: Streptococcus pneumoniae, an opportunistic pathogen commonly carried asymptomatically in the nasopharynx of children, is associated with increasing rates of treatment failures due to a worldwide increase in drug resistance. We investigated the carriage of S. pneumoniae in children 5 years or younger, the identity of prevalent serotypes, the rates of resistance to macrolides and other antimicrobial agents and the genotypes responsible for macrolide resistance. Materials and Methods: Nasopharyngeal swabs were collected from 157 children under 5 years for cultural isolation of S. pneumoniae. Antibiogram of isolates was determined using the disk diffusion test, and the minimal inhibitory concentration to macrolides was determined using the E-test. Isolate serotypes and macrolide resistance genes, erm(B and mef(E, were identified using multiplex polymerase chain reactions. Results: S. pneumoniae was recovered from 33.8% of children; 41.9% among males and 21.9% among females (P = 0.009. The highest carriage rate occurred among age groups 7-12 months and 49-60 months. Most frequent serotypes were 19F, 6A/B, 11A, 19A, 14 and 15B/C. Resistance to macrolides was 60.4%. Resistance to oxacillin, trimethoprim/sulfamethoxazole and clindamycin was present among 90.6%, 54.7% and 32.1% of isolates, respectively. All isolates were susceptible to chloramphenicol, levofloxacin and vancomycin. Isolates resistant to one or more macrolide drugs were more likely to be multidrug resistant. Resistance to clindamycin or oxacillin coexisted with macrolide resistance. Among the erythromycin-resistant isolates, erm(B, mef(E and erm(B and mef(E genes were present at rates of 43.8%, 37.5% and 6.3%, respectively. Erm(B and mef(E were associated with very high level and moderate-to-high level resistance to macrolides, respectively. Conclusion: A significant proportion of children harboured macrolide and multidrug-resistant S. pneumoniae.
Le Hello, Simon; Hendriksen, Rene S.; Doublet, Benoit
National Salmonella surveillance systems from France, England and Wales, Denmark, and the United States identified the recent emergence of multidrug-resistant isolates of Salmonella enterica serotype Kentucky displaying high-level resistance to ciprofloxacin. A total of 489 human cases were ident...
Cai, H. Y.; Lu, L.; Muckle, C. A.; Prescott, J. F.; Chen, S.
An antibody microarray assay was developed for Salmonella serotyping based on the Kauffmann-White scheme. A model (8 by 15) array was constructed using 35 antibodies for identification of 20 common Salmonella serovars and evaluated using 117 target and 73 nontarget Salmonella strains. The assay allowed complete serovar identification of 86 target strains and partial identification of 30 target strains and allowed exclusion of the 73 nontarget strains from the target serovars.
A commercial duck company that raises approximately two million Pekin ducks per year experienced an outbreak of Riemerella anatipestifer(RA)on nine farms over a one year period. Due to concerns that the bacteria was being spread from farm to farm, an investigation using serotyping and DNA fingerprin...
Full Text Available Species B human adenoviruses (Ads are increasingly associated with outbreaks of acute respiratory disease in U.S. military personnel and civil population. The initial interaction of Ads with cellular attachment receptors on host cells is via Ad fiber knob protein. Our previous studies showed that one species B Ad receptor is the complement receptor CD46 that is used by serotypes 11, 16, 21, 35, and 50 but not by serotypes 3, 7, and 14. In this study, we attempted to identify yet-unknown species B cellular receptors. For this purpose we used recombinant Ad3 and Ad35 fiber knobs in high-throughput receptor screening methods including mass spectrometry analysis and glycan arrays. Surprisingly, we found that the main interacting surface molecules of Ad3 fiber knob are cellular heparan sulfate proteoglycans (HSPGs. We subsequently found that HSPGs acted as low-affinity co-receptors for Ad3 but did not represent the main receptor of this serotype. Our study also revealed a new CD46-independent infection pathway of Ad35. This Ad35 infection mechanism is mediated by cellular HSPGs. The interaction of Ad35 with HSPGs is not via fiber knob, whereas Ad3 interacts with HSPGs via fiber knob. Both Ad3 and Ad35 interacted specifically with the sulfated regions within HSPGs that have also been implicated in binding physiologic ligands. In conclusion, our findings show that Ad3 and Ad35 directly utilize HSPGs as co-receptors for infection. Our data suggest that adenoviruses evolved to simulate the presence of physiologic HSPG ligands in order to increase infection.
K.L. Ravi Kumar
Full Text Available Background & objectives: Information related to nasopharyngeal carriage of Streptococcus pneumoniae among healthy children is scanty in India. This prospective study was undertaken to determine the presence of asymptomatic nasopharyngeal colonization, assess serogroups/types (SGT and drug resistance of S. pneumoniae in children below five years of age. Methods: A total of 109 male and 81 female children in the age group of three months to five years belonging to different socio-economic classes were enrolled. They were recruited across all age groups from those attending paediatric OPD of a tertiary care and research centre for immunization program. Fifty three isolates identified as pneumococci were tested for their antimicrobial susceptibility pattern by Kirby-Bauer′s disc diffusion and E-Test methods. Serotyping was performed by detection of the quelling reaction with specific antiserum. Result: The pneumococcal carriage rate in the study population was 27.9 per cent. The isolation rate was associated with age being higher (49.2% in smaller children (3-12 months and among male (62.2%. The most prevalent SGTs were 19 followed by 10, 14 and 7; 21 per cent of isolates belonging to serotype 10 (n=7 were 11 (n=4 were not covered in any of the conjugate vaccines currently available in Indian market. Resistance to co-trimoxazole, tetracycline, penicillin and erythromycin was observed in 91 per cent (n=48, 36 per cent (n=19, 17 per cent (n=9 and 9 per cent (n=5 isolates, respectively. All the penicillin resistant isolates were found to be intermediately resistant by E-Test. Multidrug resistance was observed in 19 per cent (n=10 isolates. Interpretation & conclusions: High level of antibiotic resistance was present in S. pneumoniae isolated from healthy children below age five. A pneumococcal conjugate vaccine with the prevailing SGTs would help to reduce the pool of antibiotic resistant pneumococci. Continued surveillance of serotypes and tracking
Here we report two genomes, one complete and one draft, from virulent bovine strains of Mannheimia haemolytica(strains D171 and D35)serotype A2 recovered prior to the field usage of modern antimicrobial drugs....
Gaye, Alioune; Faye, Oumar; Diagne, Cheikh T; Faye, Ousmane; Diallo, Diawo; Weaver, Scott C; Sall, Amadou A; Diallo, Mawlouth
To investigate the potential for domestic and wild populations of Aedes aegypti from Dakar and Kedougou to develop a disseminated infection after exposure to DENV-3 and DENV-1. We have exposed sylvatic and urban population of Ae. aegypti from Senegal to bloomeals containing dengue serotype 1 and 3. At different incubation period, individual mosquito legs/wings and bodies were tested for virus presence using real time RT-PCR to estimate the infection and dissemination rates. The data indicated low susceptibility to DENV-3 (infection: 2.4-15.2%, and dissemination rates: 0-8.3%) and higher susceptibility to DENV-1 (infection and dissemination rates up to 50%). Aedes aegypti from Senegal seem able to develop a disseminated infection of DENV-1 and DENV-3. Further studies are needed to test their ability to transmit the two serotypes. © 2014 John Wiley & Sons Ltd.
Kovacevic, Jovana; Arguedas-Villa, Carolina; Wozniak, Anna; Tasara, Taurai; Allen, Kevin J
Listeria monocytogenes strains belonging to serotypes 1/2a and 4b are frequently linked to listeriosis. While inlA mutations leading to premature stop codons (PMSCs) and attenuated virulence are common in 1/2a, they are rare in serotype 4b. We observed PMSCs in 35% of L. monocytogenes isolates (n = 54) recovered from the British Columbia food supply, including serotypes 1/2a (30%), 1/2c (100%), and 3a (100%), and a 3-codon deletion (amino acid positions 738 to 740) seen in 57% of 4b isolates from fish-processing facilities. Caco-2 invasion assays showed that two isolates with the deletion were significantly more invasive than EGD-SmR (P cold temperature following a downshift from 37°C to 4°C. Overall, three distinct cold-adapting groups (CAG) were observed: 46% were fast (200 h) adaptors. Intermediate CAG strains (70%) more frequently possessed inlA PMSCs than did fast (20%) and slow (10%) CAGs; in contrast, 87% of fast adaptors lacked inlA PMSCs. In conclusion, we report food chain-derived 1/2a and 4b serotypes with a 3-codon deletion possessing invasive behavior and the novel association of inlA genotypes encoding a full-length InlA with fast cold-adaptation phenotypes.
Hermansen, L T; Loft, A G; Christiansen, A A
OBJECTIVES: To investigate whether antibody response patterns against Klebsiella pneumoniae capsular serotypes can discriminate patients with axial spondyloarthritis (axSpA) from patients with non-specific low back pain (LBP). METHOD: Immunoglobulin (Ig)G and IgA antibodies against K. pneumoniae...... capsular serotypes K2, K26, K36, and K50 were measured, and antibody seropositivity compared between groups and analysed for patient correlation in five different groups: (a) 96 patients fulfilling the Assessment of SpondyloArthritis International Society (ASAS) classification criteria for axSpA; (b) 38...... ankylosing spondylitis (AS) served as the negative and positive control groups. RESULTS: There was no difference in IgG and IgA seropositivity against all serotypes between the axSpA, non-axSpA, and LBP groups. No significant correlations were found between anti-Klebsiella antibodies and age, gender, HLA-B27...
Analysis of DNA samples of Salmonella serotypes (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella Infantis, Salmonella Heidelberg and Salmonella Kentucky) were performed using Fourier transform infrared spectroscopy (FT-IR) spectrometer by placing directly in contact with a diamond attenua...