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Sample records for ptxa1 serotype fim3

  1. Antibody responses to individual Bordetella pertussis fimbrial antigen Fim2 or Fim3 following immunization with the five-component acellular pertussis vaccine or to pertussis disease.

    Science.gov (United States)

    Alexander, Frances; Matheson, Mary; Fry, Norman K; Labram, Briony; Gorringe, Andrew R

    2012-11-01

    Bordetella pertussis expresses two serologically distinct fimbriae (Fim2 and Fim3) which are included in the Sanofi Pasteur 5-component acellular pertussis vaccine, and antibody responses to these antigens have been shown to be associated with protection. Studies to date have assessed the IgG response to this vaccine using a copurified mixture of Fim2 and Fim3, and the response to the individual antigens has not been characterized. We have purified separate Fim2 and Fim3 from strains that express either Fim2 or Fim3 and have used these antigens in an enzyme-linked immunosorbent assay (ELISA) to quantify IgG responses following immunization with 5-component acellular pertussis vaccine in 15-month-old, 4- to 6-year-old, and 11- to 18-year-old subjects. All individuals showed increases in Fim2 and Fim3 IgG concentrations following immunization, with 3-fold-greater Fim2 than Fim3 IgG concentrations seen in the younger two age groups. Fim2 IgG concentrations were 1.5-fold greater than Fim3 IgG concentrations in the 11- to 18-year-olds. We have also compared Fim2 and Fim3 IgG concentrations in individuals with prolonged cough who were diagnosed as having recent pertussis using a pertussis toxin (Ptx) IgG ELISA with individuals with prolonged cough but without elevated Ptx IgG concentrations. Individuals with evidence of recent pertussis had greater Fim3 IgG concentrations, consistent with the predominant serotype of isolates obtained in the United Kingdom. However, a surprising number of individuals had moderate Fim2 IgG concentrations despite very few isolates of that serotype obtained in the sampling period.

  2. Antibody responses to Bordetella pertussis Fim2 or Fim3 following immunization with a whole-cell, two-component, or five-component acellular pertussis vaccine and following pertussis disease in children in Sweden in 1997 and 2007.

    Science.gov (United States)

    Hallander, Hans; Advani, Abdolreza; Alexander, Frances; Gustafsson, Lennart; Ljungman, Margaretha; Pratt, Catherine; Hall, Ian; Gorringe, Andrew R

    2014-02-01

    Bordetella pertussis fimbriae (Fim2 and Fim3) are components of a five-component acellular pertussis vaccine (diphtheria-tetanus-acellular pertussis vaccine [DTaP5]), and antibody responses to fimbriae have been associated with protection. We analyzed the IgG responses to individual Fim2 and Fim3 in sera remaining from a Swedish placebo-controlled efficacy trial that compared a whole-cell vaccine (diphtheria-tetanus-whole-cell pertussis vaccine [DTwP]), a two-component acellular pertussis vaccine (DTaP2), and DTaP5. One month following three doses of the Fim-containing vaccines (DTwP or DTaP5), anti-Fim2 geometric mean IgG concentrations were higher than those for anti-Fim3, with a greater anti-Fim2/anti-Fim3 IgG ratio elicited by DTaP5. We also determined the responses in vaccinated children following an episode of pertussis. Those who received DTaP5 showed a large rise in anti-Fim2 IgG, reflecting the predominant Fim2 serotype at the time. In contrast, those who received DTwP showed an equal rise in anti-Fim2 and anti-Fim3 IgG concentrations, indicating that DTwP may provide a more efficient priming effect for a Fim3 response following contact with B. pertussis. Anti-Fim2 and anti-Fim3 IgG concentrations were also determined in samples from two seroprevalence studies conducted in Sweden in 1997, when no pertussis vaccine was used and Fim2 isolates predominated, and in 2007, when either DTaP2 or DTaP3 without fimbriae was used and Fim3 isolates predominated. Very similar distributions of anti-Fim2 and anti-Fim3 IgG concentrations were obtained in 1997 and 2007, except that anti-Fim3 concentrations in 1997 were lower. This observation, together with the numbers of individuals with both anti-Fim2 and anti-Fim3 IgG concentrations, strongly suggests that B. pertussis expresses both Fim2 and Fim3 during infection.

  3. Bordetella pertussis isolates in Finland: Serotype and fimbrial expression

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    Mertsola Jussi

    2008-09-01

    Full Text Available Abstract Background Bordetella pertussis causes whooping cough or pertussis in humans. It produces several virulence factors, of which the fimbriae are considered adhesins and elicit immune responses in the host. B. pertussis has three distinct serotypes Fim2, Fim3 or Fim2,3. Generally, B. pertussis Fim2 strains predominate in unvaccinated populations, whereas Fim3 strains are often isolated in vaccinated populations. In Finland, pertussis vaccination was introduced in 1952. The whole-cell vaccine contained two strains, 18530 (Fim3 since 1962 and strain 1772 (Fim2,3 added in 1976. After that the vaccine has remained the same until 2005 when the whole-cell vaccine was replaced by the acellular vaccine containing pertussis toxin and filamentous hemagglutinin. Our aims were to study serotypes of Finnish B. pertussis isolates from 1974 to 2006 in a population with > 90% vaccination coverage and fimbrial expression of the isolates during infection. Serotyping was done by agglutination and serotype-specific antibody responses were determined by blocking ELISA. Results Altogether, 1,109 isolates were serotyped. Before 1976, serotype distributions of Fim2, Fim3 and Fim2,3 were 67%, 19% and 10%, respectively. From 1976 to 1998, 94% of the isolates were Fim2 serotype. Since 1999, the frequency of Fim3 strains started to increase and reached 83% during a nationwide epidemic in 2003. A significant increase in level of serum IgG antibodies against purified fimbriae was observed between paired sera of 37 patients. The patients infected by Fim3 strains had antibodies which blocked the binding of monoclonal antibodies to Fim3 but not to Fim2. Moreover, about one third of the Fim2 strain infected patients developed antibodies capable of blocking of binding of both anti-Fim2 and Fim3 monoclonal antibodies. Conclusion Despite extensive vaccinations in Finland, B. pertussis Fim2 strains were the most common serotype. Emergence of Fim3 strains started in 1999 and

  4. Bordetella pertussis fim3 gene regulation by BvgA: phosphorylation controls the formation of inactive vs. active transcription complexes.

    Science.gov (United States)

    Boulanger, Alice; Moon, Kyung; Decker, Kimberly B; Chen, Qing; Knipling, Leslie; Stibitz, Scott; Hinton, Deborah M

    2015-02-10

    Two-component systems [sensor kinase/response regulator (RR)] are major tools used by microorganisms to adapt to environmental conditions. RR phosphorylation is typically required for gene activation, but few studies have addressed how and if phosphorylation affects specific steps during transcription initiation. We characterized transcription complexes made with RNA polymerase and the Bordetella pertussis RR, BvgA, in its nonphosphorylated or phosphorylated (BvgA∼P) state at P(fim3), the promoter for the virulence gene fim3 (fimbrial subunit), using gel retardation, potassium permanganate and DNase I footprinting, cleavage reactions with protein conjugated with iron bromoacetamidobenzyl-EDTA, and in vitro transcription. Previous work has shown that the level of nonphosphorylated BvgA remains high in vivo under conditions in which BvgA is phosphorylated. Our results here indicate that surprisingly both BvgA and BvgA∼P form open and initiating complexes with RNA polymerase at P(fim3). However, phosphorylation of BvgA is needed to generate the correct conformation that can transition to competent elongation. Footprints obtained with the complexes made with nonphosphorylated BvgA are atypical; while the initiating complex with BvgA synthesizes short RNA, it does not generate full-length transcripts. Extended incubation of the BvgA/RNA polymerase initiated complex in the presence of heparin generates a stable, but defective species that depends on the initial transcribed sequence of fim3. We suggest that the presence of nonphosphorylated BvgA down-regulates P(fim3) activity when phosphorylated BvgA is present and may allow the bacterium to quickly adapt to the loss of inducing conditions by rapidly eliminating P(fim3) activation once the signal for BvgA phosphorylation is removed.

  5. Expresión de las fimbrias Fim2 y Fim3 desde el plasmidio pMMB67 en cepas de Bordetella pertussis

    OpenAIRE

    Lourdes Proenza; Javier Campos; Beatriz Ferrán; Ernesto Marcos; Celso Pérez

    2010-01-01

    Bordetella pertussis, el agente etiológico de la tos ferina, produce dos tipos de fimbrias serológicamente diferentes, denominadas Fim2 y Fim3. Las fimbrias 2 y 3 están compuestas por una subunidad proteica mayoritaria Fim2, de 22,5 kDa y Fim3, de 22 kDa. Las fimbrias desempeñan un papel inmunomodulador y además, existe una correlación entre la presencia de anticuerpos aglutinantes antifimbrias y la protección contra B. pertussis en pacientes humanos, todo esto ha conducido a la inclusión de ...

  6. 中国百日咳鲍特菌血清型及其相关基因分析%Serotype and fimbriae-genotype analysis of Chinese Bordetella pertussis strains

    Institute of Scientific and Technical Information of China (English)

    徐颖华; 张柳; 王丽婵; 骆鹏; 卫辰; 侯启明; 张庶民

    2010-01-01

    目的 了解我国1955-2005年临床分离百日咳鲍特菌及疫苗株的血清型及其相关基因特征.方法 应用抗菌毛蛋白2(fim2)和3(fim3)单克隆抗体凝集反应分析我国不同时期分离的80株百日咳鲍特菌株和3株疫苗株的血清型,并与相应的多克隆抗体方法进行比较分析;同时应用PCR方法扩增这些菌株fim2和fimd基因,并对这些PCR产物进行DNA测序分析.结果 研究表明,与多克隆抗体分析结果相比较,单克隆抗体玻片凝集方法和微量凝集反应除一株临床分离株的血清型分析结果不同,其余菌株的结果均一致.研究菌株的血清型分析结果显示17株临床分离菌株和CS与P3S10疫苗株的血清型为fim2&3型、48株菌为fim2型、15株分离菌株与18530疫苗株为fim3型.在我国扩大免疫规划前分离菌株的血清型以fim2型和fim2&3型为主,随着大范围的百日咳疫苗接种,临床分离菌株中fimd型血清型细菌所占的比例逐渐增多.分析菌株中fim2和fimd的基因型以fim2-1(92.5%)和fim3-A(95.0%)亚型为主;18530疫苗株基因型为fim2-2和fim3-A,而其他两株疫苗株的基因型均为fim2-1和fim3-A.在2000年以后,分离出现含有fim3-B和fim3-D亚型菌株,这些结果表明随着我国大范围百日咳疫苗免疫接种,百日咳分离菌株表达的血清型及其基因序列也出现适应性变异.结论 本研究证实了抗fim2和fim3单克隆抗体在百日咳血清型分析的特异性和实用性.对我国不同时期分离菌株和疫苗株的血清型分析,为我国百日咳疫苗株的检定、流行病学和细菌进化的研究奠定了基础.%Objective To understand serotype and fimbriae-genotype of B. pertussis vaccine strains and isolates from different periods in China. Methods Serotype of eighty isolates and three vaccine strains were determined using anti-fim2 and fim3 monoclonal antibodies compared with polyclonal antisera. Fim2 and fim 3 genes were amplified by PCR and the

  7. Plasticity of fimbrial genotype and serotype within populations of Bordetella pertussis: analysis by paired flow cytometry and genome sequencing.

    Science.gov (United States)

    Vaughan, Thomas E; Pratt, Catherine B; Sealey, Katie; Preston, Andrew; Fry, Norman K; Gorringe, Andrew R

    2014-09-01

    The fimbriae of Bordetella pertussis are required for colonization of the human respiratory tract. Two serologically distinct fimbrial subunits, Fim2 and Fim3, considered important vaccine components for many years, are included in the Sanofi Pasteur 5-component acellular pertussis vaccine, and the World Health Organization recommends the inclusion of strains expressing both fimbrial serotypes in whole-cell pertussis vaccines. Each of the fimbrial major subunit genes, fim2, fim3, and fimX, has a promoter poly(C) tract upstream of its -10 box. Such monotonic DNA elements are susceptible to changes in length via slipped-strand mispairing in vitro and in vivo, which potentially causes on/off switching of genes at every cell division. Here, we have described intra-culture variability in poly(C) tract lengths and the resulting fimbrial phenotypes in 22 recent UK B. pertussis isolates. Owing to the highly plastic nature of fimbrial promoters, we used the same cultures for both genome sequencing and flow cytometry. Individual cultures of B. pertussis contained multiple fimbrial serotypes and multiple different fimbrial promoter poly(C) tract lengths, which supports earlier serological evidence that B. pertussis expresses both serotypes during infection.

  8. European bluetongue serotype 8

    NARCIS (Netherlands)

    Drolet, Barbara S.; Reister-Hendricks, Lindsey M.; Podell, Brendan K.; Breitenbach, Jonathan E.; Mcvey, D.S.; Rijn, van Piet A.; Bowen, Richard A.

    2016-01-01

    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 serotyp

  9. Colonization of Bordetella pertussis clinical isolates that differ by pulsed field gel electrophoresis types in the lungs of naïve mice or mice immunized with the whole-cell pertussis vaccine used in Poland.

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    Polak, Maciej; Zawadka, Monika; Mosiej, Ewa; Rabczenko, Daniel; Augustynowicz, Ewa; Guiso, Nicole; Lutyńska, Anna

    2015-04-01

    The goal of our study was to compare the elimination of Bordetella pertussis clinical isolates that differ according to pulsed field gel electrophoresis (PFGE), serotypes and genes encoding virulence factors from the lungs of naïve mice or mice immunized with commercial diphtheria-tetanus-whole-cell pertussis vaccine used in Poland. When a mixture of four isolates, given in equal proportions and harboring different PFGE profiles, serotypes, and alleles encoding virulence factors, was used to infect non-immunized mice, a single isolate, characterized by PFGE type IVγ, Fim2 phenotype and ptxA1-prn2-tcfA2-fim2-1-ptxP1-ptxC1-fim3-1 alleles, was found to be significantly predominant compared to the others. This PFGE profile is commonly found in B. pertussis isolates circulating in some European countries since the late 1990s, confirming its high fitness. The Polish commercial whole-cell pertussis vaccine induced an immunity effective at eliminating the B. pertussis isolates from the lungs. However, the elimination of the isolate harboring PFGE type C profile, Fim2,3 phenotype and ptxA1-prn1-tcfA2-fim2-1-ptxP1-ptxC1-fim3-1 alleles was delayed as compared to the others, suggesting phenotypic differences with the other isolates and vaccine strains. Nevertheless, the same isolate, when challenged into mice in the defined mixture of strains, lost the competition with the others, as measured by lung colonization efficiency. This PFGE profile represents 15 % of the isolates circulating in Poland between 2001 and 2012.

  10. Sequence variation in virulence-related genes of Bordetella pertussis isolates from Poland in the period 1959-2013.

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    Mosiej, E; Zawadka, M; Krysztopa-Grzybowska, K; Polak, M; Augustynowicz, E; Piekarska, K; Lutyńska, A

    2015-01-01

    This study aimed to characterise Bordetella pertussis isolates circulating in Poland since 1959. Sequence analysis of ptxA, ptxC, prn, tcfA, fim2, fim3 and ptxP for 175 clinical isolates and currently and previously used vaccine strains was performed. Clinical isolates from the period 1995-2013 were found to be different to three currently used vaccine strains harbouring the allelic combination ptxA2-ptxC1-ptxP1-prn1-tcfA2-fim2-1-fim3-1, seen frequently in Poland in the early pertussis vaccination period but not found after 1995. Generally, among B. pertussis isolates from the period 2000-2013, two genotypes predominated, ptxA1-ptxC1-ptxP1-prn1-tcfA2-fim2-2-fim3-1 and ptxA1-ptxC1-ptxP1-prn2-tcfA2-fim2-1-fim3-1, with frequencies of 45% and 32.5%, respectively. The isolates harbouring ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-2 and ptxA1-ptxC2-ptxP3-prn2-tcfA2-fim2-1-fim3-1 profiles, currently highly prevalent within other European Union (EU) countries, were rarely found in Poland, as they circulated in the period 2000-2013 with frequencies of 10% and 5%, respectively. We hypothesise that several previous changes of strain composition in whole-cell pertussis vaccine produced locally and used since 1960 in Poland resulted in a more diverse immune pressure in the population, resulting in different prevalence of alleles compared to elsewhere.

  11. New Salmonella serotype: Salmonella enteritidis serotype Grandhaven (30(1):r:1,2).

    OpenAIRE

    McDougal, D L; Treleaven, B E; Renshaw, E C

    1982-01-01

    A new Salmonella serotype, Salmonella enteritidis serotype Grandhaven (30(1):r:1,2), was isolated from the stool of a 35-year-old man with mild gastroenteritis. He had just returned from Sudan, Africa.

  12. Pneumococcal capsular polysaccharide structure predicts serotype prevalence.

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    Daniel M Weinberger

    2009-06-01

    Full Text Available There are 91 known capsular serotypes of Streptococcus pneumoniae. The nasopharyngeal carriage prevalence of particular serotypes is relatively stable worldwide, but the host and bacterial factors that maintain these patterns are poorly understood. Given the possibility of serotype replacement following vaccination against seven clinically important serotypes, it is increasingly important to understand these factors. We hypothesized that the biochemical structure of the capsular polysaccharides could influence the degree of encapsulation of different serotypes, their susceptibility to killing by neutrophils, and ultimately their success during nasopharyngeal carriage. We sought to measure biological differences among capsular serotypes that may account for epidemiological patterns. Using an in vitro assay with both isogenic capsule-switch variants and clinical carriage isolates, we found an association between increased carriage prevalence and resistance to non-opsonic neutrophil-mediated killing, and serotypes that were resistant to neutrophil-mediated killing tended to be more heavily encapsulated, as determined by FITC-dextran exclusion. Next, we identified a link between polysaccharide structure and carriage prevalence. Significantly, non-vaccine serotypes that have become common in vaccinated populations tend to be those with fewer carbons per repeat unit and low energy expended per repeat unit, suggesting a novel biological principle to explain patterns of serotype replacement. More prevalent serotypes are more heavily encapsulated and more resistant to neutrophil-mediated killing, and these phenotypes are associated with the structure of the capsular polysaccharide, suggesting a direct relationship between polysaccharide biochemistry and the success of a serotype during nasopharyngeal carriage and potentially providing a method for predicting serotype replacement.

  13. PCR specific for Actinobacillus pleuropneumoniae serotype 3

    DEFF Research Database (Denmark)

    Zhou, L.; Jones, S.C.P.; Angen, Øystein

    2008-01-01

    Serotypes 3 and 8 of Actinobacillus pleuropneumoniae, the aetiological agent of porcine pleuropneumonia, have been reported to predominate in the UK. Direct serotyping of isolates of the organism is typically determined by the immunological reactivity of rabbit serum to its surface polisaccharides...... of A pleuropneumoniae and 121 strains of other organisms, including all the major respiratory bacterial pathogens of pigs. The test was highly specific and sensitive and should be useful for differentiating strains of serotypes 3, 6, and 8, and in seroprevalence and epidemiological surveys in regions where serotype 3...

  14. Serotype assignment by sero-agglutination, ELISA, and PCR

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    For assessing isolates of Listeria monocytogenes serotype designation is the foremost subtyping method used. Traditionally serotyping has been done with agglutination reactions. In the last decade alternative serotyping methods were described using Enzyme Linked Immunosorbent Assay(ELISA)and Polymer...

  15. Evaluation of cross-protection of bluetongue virus serotype 4 with other serotypes in sheep

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    Gcwalisile B. Zulu

    2014-02-01

    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.

  16. Multi-serotype pneumococcal nasopharyngeal carriage prevalence in vaccine naive Nepalese children, assessed using molecular serotyping.

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    Rama Kandasamy

    Full Text Available Invasive pneumococcal disease is one of the major causes of death in young children in resource poor countries. Nasopharyngeal carriage studies provide insight into the local prevalence of circulating pneumococcal serotypes. There are very few data on the concurrent carriage of multiple pneumococcal serotypes. This study aimed to identify the prevalence and serotype distribution of pneumococci carried in the nasopharynx of young healthy Nepalese children prior to the introduction of a pneumococcal conjugate vaccine using a microarray-based molecular serotyping method capable of detecting multi-serotype carriage. We conducted a cross-sectional study of healthy children aged 6 weeks to 24 months from the Kathmandu Valley, Nepal between May and October 2012. Nasopharyngeal swabs were frozen and subsequently plated on selective culture media. DNA extracts of plate sweeps of pneumococcal colonies from these cultures were analysed using a molecular serotyping microarray capable of detecting relative abundance of multiple pneumococcal serotypes. 600 children were enrolled into the study: 199 aged 6 weeks to <6 months, 202 aged 6 months to < 12 months, and 199 aged 12 month to 24 months. Typeable pneumococci were identified in 297/600 (49.5% of samples with more than one serotype being found in 67/297 (20.2% of these samples. The serotypes covered by the thirteen-valent pneumococcal conjugate vaccine were identified in 44.4% of samples containing typeable pneumococci. Application of a molecular serotyping approach to identification of multiple pneumococcal carriage demonstrates a substantial prevalence of co-colonisation. Continued surveillance utilising this approach following the introduction of routine use of pneumococcal conjugate vaccinates in infants will provide a more accurate understanding of vaccine efficacy against carriage and a better understanding of the dynamics of subsequent serotype and genotype replacement.

  17. The cps locus of Streptococcus suis serotype 16: Development of a serotype-specific PCR assay

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    Wang, K.; Weixing, Fan; Wisselink, H.J.; Chengping, Lu

    2011-01-01

    Streptococcus suis serotype 16 can infect pigs and humans. We describe the identification and the characterization of the capsular polysaccharides synthesis locus of S. suis serotype 16. Using PCR primers flanking the capsular polysaccharides synthesis locus, a 30,101-bp fragment was amplified. Twen

  18. Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test

    DEFF Research Database (Denmark)

    Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva

    1996-01-01

    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 Western blotting, A total of 205 A. pleuropneumoniae, strains including all 12 serotype reference strains and 13 strains representing 8 common bacterial species associated with swine or related to A, pleuropneumoniae, were tested by mixing 25 mu L of polystyrene reagent with the same volume of a dense...... 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...

  19. Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test

    DEFF Research Database (Denmark)

    Dubreuil, J.D.; Letellier, A.; Stenbæk, Eva;

    1996-01-01

    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 Western blotting, A total of 205 A. pleuropneumoniae, strains including all 12 serotype reference strains and 13 strains representing 8 common bacterial species associated with swine or related to A, pleuropneumoniae, were tested by mixing 25 mu L of polystyrene reagent with the same volume of a dense...... 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...

  20. Genomic Characterization of Flavobacterium psychrophilum Serotypes and Development of a Multiplex PCR-Based Serotyping Scheme

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    Tatiana Rochat

    2017-09-01

    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.

  1. Serotypes in Saccharomyces telluris: Their relation to source of isolation

    Science.gov (United States)

    Hasenclever, H.F.; Kocan, R.M.

    1973-01-01

    Three serotypes have been characterized with three reference strains of Saccharomyces telluris and designated as A, B, and C. One reference strain of Torpulopsis bovina, the imperfect form of S. telluris, belonged to serotype B. Strains of S. telluris isolated from four columbid species were serotyped. All 98 strains of this yeast isolated from Columba livia belonged to serotype B. Three other columbid species, C. leucocephala, C. fasciata, and Zenaidura macroura harbored strains of serotype C only. Serotype A was not isolated from any of the avian species.

  2. Serotype distribution in non-bacteremic pneumococcal pneumonia

    DEFF Research Database (Denmark)

    Benfield, Thomas Lars Vibe; Skovgaard, Marlene; Schønheyder, Henrik Carl

    2013-01-01

    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)....

  3. Why are dengue virus serotypes so distantly related? Enhancement and limiting serotype similarity between dengue virus strains.

    OpenAIRE

    Kawaguchi, Isao; Sasaki, Akira; Boots, Michael

    2003-01-01

    Dengue virus, the causative agent of dengue fever, has four major serotypes characterized by large genetic and immunological distances. We propose that the unusually large distances between the serotypes can be explained in the light of a process of antibody-dependent enhancement (ADE) leading to increased mortality. Antibody-dependent enhancement results from a new infection with a particular serotype in an individual with acquired immunity to a different serotype. Classical dengue fever cau...

  4. Emerging resistant serotypes of invasive Streptococcus pneumoniae

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    Elshafie S

    2016-06-01

    Full Text Available Sittana Elshafie,1,2 Saad J Taj-Aldeen2,3 1Qatar Orthopedic and Sports Medicine Hospital, Aspetar, Doha, Qatar; 2Weill Cornell Medicine-Qatar, 3Department of Laboratory Medicine and Pathology, Microbiology Division, Hamad Medical Corporation, Doha, Qatar Background: Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7. Methods: A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. Results: The most common serotypes for all age groups were 3 (12.70%, 14 (11.90%, 1 (11.90%, 19A (9.00%, 9V (5.20%, 23F (5.20%, and 19F (4.50%. Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10, and the 13-valent conjugated vaccine (PCV-13 were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2–5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6–64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46% were multidrug resistant (MDR and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in

  5. Three-Dimensional Structure of Canine Adenovirus Serotype 2 Capsid▿

    OpenAIRE

    Schoehn, Guy; El Bakkouri, Majida; Fabry, Céline M. S.; Billet, Oliver; Leandro F. Estrozi; Le, Van Long; Curiel, David T.; Kajava, Andrey V; Ruigrok, Rob W. H.; Eric J Kremer

    2008-01-01

    There are more than 100 known adenovirus (AdV) serotypes, including 50 human serotypes. Because AdV-induced disease is relatively species specific, vectors derived from nonhuman serotypes may have wider clinical potential based, in part, on the lack of ubiquitous memory immunity. Whereas a few of the human serotype capsids have been studied at the structural level, none of the nonhuman serotypes has been analyzed. The basis laid by the analysis of human AdV (hAdV) has allowed us to determine ...

  6. Detection of an Actinobacillus pleuropneumoniae serotype 2 lipopolysaccharide (LPS) variant

    DEFF Research Database (Denmark)

    Stenbaek, E.I.; HovindHaugen, K.

    1996-01-01

    Until now 12 serotypes of Actinobacillus pleuropneumoniae have been recognized. The specificity of the serotypes reside in the carbohydrate composition of the capsular polysaccharides and lipopolysaccharides (LPS). The LPS of A. pleuropneumoniae serotype 2 is a smooth type LPS with O-chains of li......Until now 12 serotypes of Actinobacillus pleuropneumoniae have been recognized. The specificity of the serotypes reside in the carbohydrate composition of the capsular polysaccharides and lipopolysaccharides (LPS). The LPS of A. pleuropneumoniae serotype 2 is a smooth type LPS with O......-chains of linear repeating pentasaccharide units with an O-acetyl group linked to a glucose unit. A monoclonal antibody (MAb 102-G02) directed against A. pleuropneumoniae serotype 2 was characterized in enzyme linked immunosorbent assay (ELISA) and in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS...

  7. Evaluation of a multiplex PCR test for simultaneous identification and serotyping of Actinobacillus pleuropneumoniae serotypes 2, 5, and 6

    DEFF Research Database (Denmark)

    Jessing, Stine Graakjær; Angen, Øystein; Inzana, Tomas J.

    2003-01-01

    , and 6 were combined with the already existing species-specific primers used in a PCR test based on the omlA gene. The PCR test was evaluated with serotype reference strains of A. pleuropneumoniae as well as 182 Danish field isolates previously serotyped by latex agglutination or immunodiffusion. For all...... that cross-reacted by the latex agglutination test were of serotype 2, 5, or 6. Determination of the serotype by PCR represents a convenient and specific method for the serotyping of A. pleuropneumoniae in diagnostic laboratories....

  8. Fatal meningitis in a previously healthy young adult caused by Streptococcus pneumoniae serotype 38: an emerging serotype?

    Directory of Open Access Journals (Sweden)

    Pearse Lisa A

    2005-05-01

    Full Text Available Abstract Background In December 2001, a fatal case of pneumococcal meningitis in a Marine Corps recruit was identified. As pneumococcal vaccine usage in recruit populations is being considered, an investigation was initiated into the causative serotype. Case presentation Traditional and molecular methods were utilized to determine the serotype of the infecting pneumococcus. The pneumococcal isolate was identified as serotype 38 (PS38, a serotype not covered by current vaccine formulations. The global significance of this serotype was explored in the medical literature, and found to be a rare but recognized cause of carriage and invasive disease. Conclusion The potential of PS38 to cause severe disease is documented in this report. Current literature does not support the hypothesis that this serotype is increasing in incidence. However, as we monitor the changing epidemiology of pneumococcal illness in the US in this conjugate era, PS38 might find a more prominent and concerning niche as a replacement serotype.

  9. Changes in genetic diversity of the Bordetella pertussis population in Serbia between 1953 and 2011

    Directory of Open Access Journals (Sweden)

    Plješa Tatjana

    2014-01-01

    Full Text Available Mass vaccination has significantly reduced the incidence of pertussis, however, the disease is re-emerging, even in some countries with high vaccination coverage. In Serbia, whole cell pertussis vaccine was introduced in 1957. To monitor changes in bacterial population, 77 isolates collected from 1953 to 2011 were studied. The methods included serotyping of fimbriae (Fim, genotyping of pertactin (prn and pertussis toxin S1 subunit (ptxA. A shift from ptxA2 to ptxA1 has been observed in isolates since the late of 1960s. In the period 1961-1979, the genotype ptxA1 became as common as genotype ptxA2. After that, during the period 1980-1989, the predominant ptx genotype was ptxA1. The reappearance of the ptxA2 allele followed an addition of the two strains harboring ptxA1 in the vaccine in 1985. The allele prn1 was predominant among the Serbian isolates, though prn3 and prn11 have been detected since 1981. The prn2 allele was only found in one strain isolated in 1984, two of the four strains isolated in 2000 and in three isolated strains from 2011. Serotype Fim2.3 disappeared before 1980 and serotype Fim2 became predominant thereafter. The results of this study indicate that the B. pertussis population in Serbia is different from other vaccinated populations and that this difference may be related to the vaccine used.

  10. Microarray for serotyping of Bartonella species

    OpenAIRE

    Raoult Didier; Nappez Claude; Bonhomme Cyrille J

    2007-01-01

    Abstract Background Bacteria of the genus Bartonella are responsible for a large variety of human and animal diseases. Serological typing of Bartonella is a method that can be used for differentiation and identification of Bartonella subspecies. Results We have developed a novel multiple antigenic microarray to serotype Bartonella strains and to select poly and monoclonal antibodies. It was validated using mouse polyclonal antibodies against 29 Bartonella strains. We then tested the microarra...

  11. Microarray for serotyping of Bartonella species

    Directory of Open Access Journals (Sweden)

    Raoult Didier

    2007-06-01

    Full Text Available Abstract Background Bacteria of the genus Bartonella are responsible for a large variety of human and animal diseases. Serological typing of Bartonella is a method that can be used for differentiation and identification of Bartonella subspecies. Results We have developed a novel multiple antigenic microarray to serotype Bartonella strains and to select poly and monoclonal antibodies. It was validated using mouse polyclonal antibodies against 29 Bartonella strains. We then tested the microarray for serotyping of Bartonella strains and defining the profile of monoclonal antibodies. Bartonella strains gave a strong positive signal and all were correctly identified. Screening of monoclonal antibodies towards the Gro EL protein of B. clarridgeiae identified 3 groups of antibodies, which were observed with variable affinities against Bartonella strains. Conclusion We demonstrated that microarray of spotted bacteria can be a practical tool for serotyping of unidentified strains or species (and also for affinity determination by polyclonal and monoclonal antibodies. This could be used in research and for identification of bacterial strains.

  12. Protein antigen in serotype k Streptococcus mutans clinical isolates.

    Science.gov (United States)

    Nakano, K; Nomura, R; Nemoto, H; Lapirattanakul, J; Taniguchi, N; Grönroos, L; Alaluusua, S; Ooshima, T

    2008-10-01

    Streptococcus mutans, a major pathogen of dental caries and infective endocarditis, is classified into serotypes c, e, f, and k, with serotype k strains recently reported to be frequently detected in persons with infective endocarditis. Thus, we hypothesized that common properties associated with infective endocarditis are present in those strains. Fifty-six oral S. mutans strains, including 11 serotype k strains, were analyzed. Western blotting analysis revealed expression of the 3 types of glucosyltransferases in all strains, while expression of the approximately 190-kDa cell-surface protein (PA) was absent in 12 strains, among which the prevalence of serotype k (7/12) was significantly high. Furthermore, cellular hydrophobicity and phagocytosis susceptibility were lower in the group of serotype k strains. These results indicate that the absence of PA expression, low cellular hydrophobicity, and phagocytosis susceptibility are common bacterial properties associated with serotype k strains, which may be associated with virulence for infective endocarditis.

  13. The use of oligonucleotide probes for meningococcal serotype characterization

    Directory of Open Access Journals (Sweden)

    SACCHI Claudio Tavares

    1998-01-01

    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.

  14. Serological characterization of Actinobacillus pleuropneumoniae biotype 1 strains antigenically related to both serotypes 2 and 7

    DEFF Research Database (Denmark)

    Nielsen, R.; Andresen, Lars Ole; Plambeck, Tamara

    1996-01-01

    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...

  15. Antibiotic Susceptibilities and Serotyping of Clinical Streptococcus Agalactiae Isolates

    Directory of Open Access Journals (Sweden)

    Altay Atalay

    2011-11-01

    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.

  16. Probability of identifying different salmonella serotypes in poultry samples

    Science.gov (United States)

    Recent work has called attention to the unequal competitive abilities of different Salmonella serotypes in standard broth culture and plating media. Such serotypes include Enteritidis and Typhimurium that are specifically targeted in some regulatory and certification programs because they cause a l...

  17. Serotype-specific mortality from invasive Streptococcus pneumoniae disease revisited

    DEFF Research Database (Denmark)

    Martens, Pernille; Worm, Signe Westring; Lundgren, Bettina

    2004-01-01

    with serotype 1 was associated with a decreased risk of death (RR 0.23 (95% CI, 0.06-0.97)). Additionally, older age, relative leucopenia and relative hypothermia were independent predictors of mortality. CONCLUSION: Our study shows that capsular serotypes independently influenced the outcome from invasive...

  18. First Complete Genome Sequence of Haemophilus influenzae Serotype a

    Science.gov (United States)

    Hayden, Kristy

    2017-01-01

    ABSTRACT Haemophilus influenzae is an important human pathogen that primarily infects small children. In recent years, H. influenzae serotype a has emerged as a significant cause of invasive disease among indigenous populations. Here, we present the first complete whole-genome sequence of H. influenzae serotype a. PMID:28104664

  19. Salmonella serotypes in reptiles and humans, French Guiana.

    Science.gov (United States)

    Gay, Noellie; Le Hello, Simon; Weill, François-Xavier; de Thoisy, Benoit; Berger, Franck

    2014-05-14

    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.

  20. Serotypes of Streptococcus pneumoniae causing major pneumococcal infections

    Directory of Open Access Journals (Sweden)

    Yu. V. Lobzin

    2013-01-01

    Full Text Available First in Russia prospective non-interventional hospital-based study on Streptococcus pneumoniae serotypes causing meningitis and acute otitis media (AOM in children and community-acquired pneumonia (CAP in children and adults, as well as serotype coverage by pneumococcal conjugate vaccines (PCV’s of different composition has been conducted. Serotypes 19F, 14 and serogroup 6 are the leading in meningitis; serotype coverage is 70,6% for PCV7, and 76,5% – for PCV10 and PCV13. Among S. pneumoniae serotypes causing AOM 19F, 3, 23F and serogroup 6 have been the most prevalent in Saint Petersburg. PCV7 and PCV10 provide equal serotypes coverage in AOM – 63,2% among children 0–2 years old, and 32,5% among children 5–17 years old. PCV13 covers up to 79% of serotypes in infants. In CAP PCV7 and PCV10 provide 57,1% serotype coverage in children and 56,1% – in adults. Serotype coverage in CAP for PCV13 has been 14,3% and 34,5% higher for children and adults, correspondingly. Obtained data supports PCV inclusion in children immunization program in Saint Petersburg, whereas PCV13 provides the broadest serotype coverage. In the course PCV’s implementation continued pneumococcal infection surveillance is advisable.

  1. Antibiofilm Activity of Actinobacillus pleuropneumoniae Serotype 5 Capsular Polysaccharide

    Science.gov (United States)

    Karwacki, Michael T.; Kadouri, Daniel E.; Bendaoud, Meriem; Izano, Era A.; Sampathkumar, Vandana; Inzana, Thomas J.; Kaplan, Jeffrey B.

    2013-01-01

    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. PMID:23691104

  2. Antibiofilm activity of Actinobacillus pleuropneumoniae serotype 5 capsular polysaccharide.

    Directory of Open Access Journals (Sweden)

    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.

  3. Selective and genetic constraints on pneumococcal serotype switching.

    Directory of Open Access Journals (Sweden)

    Nicholas J Croucher

    2015-03-01

    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.

  4. The relationship between pneumococcal serotypes and antibiotic resistance.

    Science.gov (United States)

    Song, Jae-Hoon; Dagan, Ron; Klugman, Keith P; Fritzell, Bernard

    2012-04-05

    Streptococcus pneumoniae (SP) causes significant burden of disease, including invasive pneumococcal disease and noninvasive diseases such as pneumonia and acute otitis media. SP has at least 93 different capsular serotypes, with the various serotypes having different propensities for producing disease or developing antibiotic resistance. An increase in the prevalence of antibiotic-resistant SP serotypes has been observed globally. The objective of this paper was to examine the relationship between antibiotic resistance and SP serotypes, with a primary focus on studies published in the past 10 years. Changing trends in antibiotic resistance and serotype distribution during this time, including those before and after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7), were analyzed. Factors that influence the prevalence of antibiotic-resistant serotypes include antibiotic selection pressure, the use of PCV7, and the emergence and spread of antibiotic-resistant clones. The emergence of multidrug resistant serotype 19A is of particular concern. Antibiotic-resistant SP is a global problem that must be addressed through multiple strategies, including national vaccination programs, antibiotic control programs, and ongoing surveillance.

  5. Dengue virus serotype in Aceh Province

    Directory of Open Access Journals (Sweden)

    Paisal

    2015-06-01

    Full Text Available WHO estimated 50 million dengue infections happen every year in the world. In Indonesia, there were 90,245 DHF cases on 2012 with 816 deaths. In the Province of Aceh, 2,269 cases happened in the same year. This study aimed to identify dengue virus serotype in Aceh. Sampling was done in Kota Banda Aceh Hospital, Kota Lhokseumawe Hospital, Kabupaten Aceh Tamiang Hospital, Kabupaten Aceh Barat Hospital, and Kabupaten Simeulue Hospital between May to December 2012. This was a clinical laboratory research with observation design using cross sectional approach. Research’s population was sample from patients with dengue clinical symptom. Using purposive sampling technique, we have collected 100 samples from the five hospitals (20 samples from each hospital. From RT-PCR, we found 16 positive samples (9 samples were DENV-4, 3 samples were DENV-1, 2 samples were DENV-2, and 2 samples were DENV-3.

  6. Leptospira interrogans serotype hardjo in dairy cows

    Directory of Open Access Journals (Sweden)

    Vidić Branka M.

    2003-01-01

    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.

  7. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    OpenAIRE

    Alvaro Díaz-Badillo; María de Lourdes Muñoz; Gerardo Perez-Ramirez; Victor Altuzar; Juan Burgueño; Mendoza-Alvarez, Julio G.; Martínez-Muñoz, Jorge P.; Alejandro Cisneros; Joel Navarrete-Espinosa; Feliciano Sanchez-Sinencio

    2014-01-01

    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 hybrid...

  8. Clonal distribution of pneumococcal serotype 19F isolates from Ghana

    DEFF Research Database (Denmark)

    Sparding, Nadja; Dayie, Nicholas Tete Kwaku Dzifa; Mills, Richael O.

    2015-01-01

    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...... Ghana were investigated; isolates from healthy children in Tamale and isolates from both healthy and children attending the outpatient department at a hospital in Accra. The isolates were previously identified and characterized by Gram staining, serotyping and susceptibility to penicillin. In this study....... The majority of isolates were penicillin intermediate resistant. In conclusion, two clones within serotype 19F were found to be dominating in pneumococcal carriage in Accra and Tamale in Ghana. Furthermore, it seems as though the clonal distribution of serotype 19F may be different from what is currently known...

  9. Dengue viruses cluster antigenically but not as discrete serotypes

    NARCIS (Netherlands)

    L. Katzelnick (Leah); J.M. Fonville (Judith); G.D. Gromowski (Gregory D.); J.B. Arriaga (Jose Bustos); A. Green (Angela); S.L. James (Sarah ); L. Lau (Louis); M. Montoya (Magelda); C. Wang (Chunling); L.A. Van Blargan (Laura A.); C.A. Russell (Colin); H.M. Thu (Hlaing Myat); T.C. Pierson (Theodore C.); P. Buchy (Philippe); J.G. Aaskov (John G.); J.L. Muñoz-Jordán (Jorge L.); N. Vasilakis (Nikos); R.V. Gibbons (Robert V.); R.B. Tesh (Robert B.); A.D.M.E. Osterhaus (Albert); R.A.M. Fouchier (Ron); A. Durbin (Anna); C.P. Simmons (Cameron P.); E.C. Holmes (Edward C.); E. Harris (Eva); S.S. Whitehead (Stephen S.); D.J. Smith (Derek James)

    2015-01-01

    textabstractThe four genetically divergent dengue virus (DENV) types are traditionally classified as serotypes. Antigenic and genetic differences among the DENV types influence disease outcome, vaccine-induced protection, epidemic magnitude, and viral evolution.We scharacterized antigenic diversity

  10. Draft Genome Sequences of Actinobacillus pleuropneumoniae Serotypes 2 and 6

    DEFF Research Database (Denmark)

    Zhan, Bujie; Angen, Øystein; Hedegaard, Jakob

    2010-01-01

    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 investigated...... at the genomic level. Here, we present the draft genome sequences of the A. pleuropneumoniae serotypes 2 (strain 4226) and 6 (strain Femo)....

  11. Isolation of Actinobacillus pleuropneumoniae serotype 2 by immunomagnetic separation

    DEFF Research Database (Denmark)

    Angen, Øystein; Heegaard, Peter M. H.; Lavritsen, D.T.

    2001-01-01

    In Denmark porcine pleuropneumonia is most frequently caused by Actinobacillus pleuropneumoniae serotype 2 (60%). Isolation of A. pleuropneumoniae from nasal cavities or tonsils from carrier animals is complicated due to the mixed bacterial flora present. An immunomagnetic separation technique (IMS...... the nasal cavity or tonsils by cultivation or PCR 6 weeks later. By using IMS A. pleuropneumoniae serotype 2 could be reisolated from the tonsils of three pigs. The LMS method represents a valuable tool for isolation of A. pleuropneumoniae from tissue samples....

  12. Clonal distribution of pneumococcal serotype 19F isolates from Ghana.

    Science.gov (United States)

    Sparding, Nadja; Dayie, Nicholas T K D; Mills, Richael O; Newman, Mercy J; Dalsgaard, Anders; Frimodt-Møller, Niels; Slotved, Hans-Christian

    2015-04-01

    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 Ghana were investigated; isolates from healthy children in Tamale and isolates from both healthy and children attending the outpatient department at a hospital in Accra. The isolates were previously identified and characterized by Gram staining, serotyping and susceptibility to penicillin. In this study, isolates of the common serotype 19F were further investigated by Multi-Locus Sequence Typing (MLST). Overall, 14 different Sequence Types (STs) were identified by MLST, of which nine were novel based on the international MLST database. Two clones within serotype 19F seem to circulate in Ghana, a known ST (ST 4194) and a novel ST (ST 9090). ST 9090 was only found in healthy children in Accra, whereas ST 4194 was found equally in all children studied. In the MLST database, other isolates of ST 4194 were also associated with serotype 19F, and these isolates came from other West African countries. The majority of isolates were penicillin intermediate resistant. In conclusion, two clones within serotype 19F were found to be dominating in pneumococcal carriage in Accra and Tamale in Ghana. Furthermore, it seems as though the clonal distribution of serotype 19F may be different from what is currently known 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.

  13. Compatible results obtained from biotyping and serotyping in Serratia marcescens.

    Science.gov (United States)

    Grimont, P A; Grimont, F; Le Minor, S; Davis, B; Pigache, F

    1979-10-01

    The correspondence between complete serotype and biotype (P.A.D. Grimont and F. Grimont, J. Clin. Microbiol. 8:73-83, 1978) of 474 Serratia marcescens strains was studied. Of 127 serotypes, 70 were represented by two or more strains of the same serotype belonged to one biotype. However, for 91% of serotypes, strains of the same serotype belonged to one biogroup--i.e., a group of closely related biotypes. Biogroups are A1 (A1a, A1b); A2/6 (A2a, A2b, A6a, A6b); A3 (A3a, A3b, A3c, A3d); A4 (A4a, A4b); A5/8 (A5, A8a, A8b, A8c); and TCT (TCT, TT). Only two serotypes were composed of a mixture of pigmented and nonpigmented biogroups. Pigmented biogroups (A1 and A2/6) were otherwise differentiated from nonpigmented biogroups (A3, A4, A5/8, and TCT) by serotyping. Some biogroups preferentially occurred in some O serogroups: A4 in 01; A2/6 in O6, O8, and O14; and A3 in O9, O12, and O15. Three H serogroups were found to be biochemically homogeneous: H1, H7, and H20 were respectively and uniquely composed of biogroups A4, TCT, and A3. A square matrix of O versus H serogroups, with the corresponding biogroup for each O X H combination, was used for comparisons between O groups and between H groups. Identical patterns of biogroups were shown by serogroups O6, O8, and O14. Taxonomical, ecological, and practical consequences of these findings are discussed.

  14. An atypical biotype I Actinobacillus pleuropneumoniae serotype 13 is present in North America

    DEFF Research Database (Denmark)

    Perry, Malcolm B.; Angen, Øystein; MacLean, Leann L.

    2012-01-01

    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...... and structurally identical with that of the reference strain of A. pleuropneumoniae serotype 10. The O-PS was characterized as a homopolymer of 1,2 linked β-d-galactofuranosyl residues, a structure unrelated to that of the O-PS produced by the reference strain of serotype 13. Strains from Canada and United States....... pleuropneumoniae serotype 10....

  15. Evaluation of a multiplex PCR for detection of serotypes K1, K2 and K5 in Klebsiella sp. and comparison of isolates within these serotypes.

    Science.gov (United States)

    Turton, Jane F; Baklan, Hatice; Siu, L K; Kaufmann, Mary E; Pitt, Tyrone L

    2008-07-01

    A multiplex PCR using targets within the serotype-specific region of the capsular polysaccharide synthesis gene cluster of serotypes K1, K2 and K5 was evaluated using the 77 reference serotype strains of Klebsiella, and a panel of clinical isolates subjected previously to conventional serotyping. The PCR was highly specific for these serotypes, which are those most associated with virulence in humans and horses. PCR confirmed that isolates of the K5 serotype had cross-reacted with antiserum for other serotypes, particularly for K7. K5 isolates received by our laboratory were almost exclusively from thoroughbred horses, and were submitted for screening prior to breeding programmes. Most, including a reference strain isolated in 1955, belonged to a cluster of genetically similar isolates of sequence type (ST) 60. K1 isolates, all from humans, belonged to a previously identified cluster of ST 23.

  16. Clinical differences among PCR-proven dengue serotype infections.

    Science.gov (United States)

    Limkittikul, Kriengsak; Yingsakmongkon, Sangchai; Jittmittraphap, Akanitt; Chuananon, Somchai; Kongphrai, Yuphin; Kowasupathr, Surasak; Rojanawatsirivit, Chaiyaporn; Mammen, Mammen P; Jampangern, Wipawee

    2005-11-01

    The objective of this study was to compare the clinical spectra of the dengue serotypes proven by the PCR technique. This retrospective study reviewed the clinical information of dengue-infected patients who were admitted to northeastern provincial hospitals in Thailand from June to September 2002. Dengue infection and viral serotypes were confirmed by polymerase chain reaction (PCR). Paired anti-dengue immunoglobulin G (IgG) and IgM from paired sera were analyzed by enzyme-linked immunosorbent assay (ELISA). Ninety-nine PCR-proven dengue-infected Thai patients were studied. Their ages ranged from 3-30 years. They were infected with DEN1, DEN2, DEN3 and DEN4 in 21, 55, 12, and 12%, respectively. Twenty-two percent had primary and 78% had secondary infections. Dengue fever was the most common presentation for both primary (77.2%) and secondary infections (46.7%). The ratios of dengue fever:dengue hemorrhagic fever (DF:DHF) and non-dengue shock syndrome:dengue shock syndrome (non-DSS:DSS) for DEN2 was the lowest of the dengue serotypes. There was no difference in the duration of fever, percentage of hepatomegaly and bleeding among the serotypes in both DF and DHF. The trends in the white blood cells, lymphocyte and atypical lymphocyte counts in DEN3 were the highest, while those of DEN1 were the lowest of the dengue serotypes.

  17. Salmonella serotype distribution in the Dutch broiler supply chain.

    Science.gov (United States)

    van Asselt, E D; Thissen, J T N M; van der Fels-Klerx, H J

    2009-12-01

    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.

  18. Botulinum Neurotoxin Serotypes Detected by Electrochemical Impedance Spectroscopy

    Science.gov (United States)

    Savage, Alison C.; Buckley, Nicholas; Halliwell, Jennifer; Gwenin, Christopher

    2015-01-01

    Botulinum neurotoxin is one of the deadliest biological toxins known to mankind and is able to cause the debilitating disease botulism. The rapid detection of the different serotypes of botulinum neurotoxin is essential for both diagnosis of botulism and identifying the presence of toxin in potential cases of terrorism and food contamination. The modes of action of botulinum neurotoxins are well-established in literature and differ for each serotype. The toxins are known to specifically cleave portions of the SNARE proteins SNAP-25 or VAMP; an interaction that can be monitored by electrochemical impedance spectroscopy. This study presents a SNAP-25 and a VAMP biosensors for detecting the activity of five botulinum neurotoxin serotypes (A–E) using electrochemical impedance spectroscopy. The biosensors are able to detect concentrations of toxins as low as 25 fg/mL, in a short time-frame compared with the current standard methods of detection. Both biosensors show greater specificity for their compatible serotypes compared with incompatible serotypes and denatured toxins. PMID:25954998

  19. Botulinum Neurotoxin Serotypes Detected by Electrochemical Impedance Spectroscopy

    Directory of Open Access Journals (Sweden)

    Alison C. Savage

    2015-05-01

    Full Text Available Botulinum neurotoxin is one of the deadliest biological toxins known to mankind and is able to cause the debilitating disease botulism. The rapid detection of the different serotypes of botulinum neurotoxin is essential for both diagnosis of botulism and identifying the presence of toxin in potential cases of terrorism and food contamination. The modes of action of botulinum neurotoxins are well-established in literature and differ for each serotype. The toxins are known to specifically cleave portions of the SNARE proteins SNAP-25 or VAMP; an interaction that can be monitored by electrochemical impedance spectroscopy. This study presents a SNAP-25 and a VAMP biosensors for detecting the activity of five botulinum neurotoxin serotypes (A–E using electrochemical impedance spectroscopy. The biosensors are able to detect concentrations of toxins as low as 25 fg/mL, in a short time-frame compared with the current standard methods of detection. Both biosensors show greater specificity for their compatible serotypes compared with incompatible serotypes and denatured toxins.

  20. Comparison of high and low virulence serotypes of Actinobacillus pleuropneumoniae by quantitative real-time PCR

    DEFF Research Database (Denmark)

    Schou, Kirstine Klitgaard; Angen, Øystein; Boye, Mette

    Until now, 15 different serotypes of Actinobacillus pleuropneumoniae (Ap) have been described based upon differences in the capsular polysaccharides of the bacterium. The virulence of different serotypes of Ap has been experimentally determined and the differences in mortality and morbidity...

  1. Serotype and Antimicrobial Resistance Patterns of Salmonella Isolates from Commercial Birds and Poultry Environment in Mississippi

    Science.gov (United States)

    To obtain information about Salmonella from commercial birds and poultry environments within Mississippi, 50 Salmonella enterica isolates were collected and characterized by Intergenic Sequence Ribotyping (ISR) serotyping and by determining antimicrobial resistance. ISR assigned serotype to all 50 S...

  2. Enteropathogenic Escherichia coli Serotypes and Endemic Diarrhea in Infants

    OpenAIRE

    M. Regina F. Toledo; Alvariza, M. do Carmo B.; Murahovschi, Jayme; Sonia R.T.S. RAMOS; Trabulsi, Luiz R.

    1983-01-01

    Enteropathogenic Escherichia coli serotypes were searched for in feces of 550 children with endemic diarrhea and in 129 controls, in São Paulo, in 1978 and 1979; serotypes O111ab:H−, O111ab:H2, and O119:H6 were significantly associated with diarrhea in children 0 to 5 months old and were the most frequent agents of diarrhea in this age group as compared with enterotoxigenic and enteroinvasive E. coli, Salmonella sp., Shigella sp., and Yersinia enterocolitica. It is concluded that various ente...

  3. Use of a Serotype-Specific DNA Microarray for Identification of Group B Streptococcus (Streptococcus agalactiae)

    OpenAIRE

    Wen, Linyan; Wang, Quan; Li, Yayue; Kong, Fanrong; Gilbert, Gwendolyn L.; Cao, Boyang; Wang, Lei; Feng, Lu

    2006-01-01

    Group B Streptococcus (GBS; Streptococcus agalactiae) is an important cause of sepsis and meningitis. Nine GBS serotypes, based on capsular polysaccharide (CPS) antigens, have been described. Their distribution varies worldwide and needs to be monitored to understand the epidemiology of GBS disease and inform the development of vaccines. In this study, we sequenced cpsH of GBS serotype II (cpsHII) and compared it with that of the other eight serotypes to identify serotype-specific regions. We...

  4. Rapid Subtyping of Dengue Virus Serotypes 1 and 4 by Restriction Site-Specific PCR

    OpenAIRE

    Marize P Miagostovich; dos Santos, Flavia B.; Gutiérrez, C. Milena; Riley, Lee W.; Harris, Eva

    2000-01-01

    We previously reported a simple subtyping method, restriction site-specific PCR (RSS-PCR), for dengue virus serotypes 2 and 3; here we describe its application for subtyping dengue virus serotypes 1 and 4. Three major RSS-PCR types were observed for dengue virus serotype 1 and two types were observed for dengue virus serotype 4, in agreement with previous strain classifications based on sequence analysis. Because of its simplicity, this method is amenable to rapid subtyping and application to...

  5. Serotype 3 remains the leading cause of invasive pneumococcal disease in adults in Portugal (2012-2014 despite continued reductions in other 13-valent conjugate vaccine serotypes.

    Directory of Open Access Journals (Sweden)

    Andreia N Horácio

    2016-10-01

    Full Text Available Since 2010 the 13-valent pneumococcal conjugate vaccine (PCV13 replaced the 7-valent vaccine (PCV7 as the leading pneumococcal vaccine used in children through the private sector. Although neither of the PCVs were used significantly in adults, changes in adult invasive pneumococcal disease (IPD were expected due to herd protection. We characterized n=1163 isolates recovered from IPD in adults in 2012-2014 with the goal of documenting possible changes in serotype prevalence and antimicrobial resistance. Among the 54 different serotypes detected, the most frequent, accounting for half of all IPD, were serotypes: 3 (14%, 8 (11%, 19A (7%, 22F (7%, 14 (6% and 7F (5%. The proportion of IPD caused by PCV7 serotypes remained stable during the study period (14%, but was smaller than in the previous period (19% in 2009-2011, p=0.003. The proportion of IPD caused by PCV13 serotypes decreased from 51% in 2012 to 38% in 2014 (p<0.001, mainly due to decreases in serotypes 7F and 19A. However, PCV13 serotype 3 remained relatively stable and the most frequent cause of adult IPD. Non-PCV13 serotypes continued the increase initiated in the late post-PCV7 period, with serotypes 8 and 22F being the most important emerging serotypes. Serotype 15A increased in 2012-2014 (0.7% to 3.5%, p=0.011 and was strongly associated with antimicrobial resistance. However, the decreases in resistant isolates among serotypes 14 and 19A led to an overall decrease in penicillin non-susceptibility (from 17% to 13%, p=0.174 and erythromycin resistance (from 19% to 13%, p=0.034. Introduction of PCV13 in the NIP for children, as well as its availability for adults may further alter the serotypes causing IPD in adults in Portugal and lead to changes in the proportion of resistant isolates.

  6. Detection and identification of Actinobacillus pleuropneumoniae serotypes 1, 2, and 8 by multiplex PCR

    DEFF Research Database (Denmark)

    Schuchert, J.A.; Inzana, T.J.; Angen, Øystein

    2004-01-01

    Multiplex PCR assays were developed to identify Actinobacillus pleuropneumoniae serotypes 1, 2, and 8. Primers designed for the conserved capsular polysaccharide (CP) export region amplified a 489-bp DNA fragment from all serotypes. Primers specific to the CP biosynthesis regions of serotypes 1, 2...

  7. Genomic Evolution Of The Mdr Serotype O12 Pseudomonas Aeruginosa Clone

    DEFF Research Database (Denmark)

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca

    2015-01-01

    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 ......, and dangerous clones like O12 can be identified quickly....

  8. Phylogenetic variation of Aggregatibacter actinomycetemcomitans serotype e reveals an aberrant distinct evolutionary stable lineage

    NARCIS (Netherlands)

    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

    2010-01-01

    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

  9. Haemophilus influenzae serotype a septic arthritis in an immunized central Australian indigenous child.

    Science.gov (United States)

    Fischer, Nicholas J

    2014-04-01

    This article describes a notable case of Haemophilus influenzae serotype a (Hia) septic arthritis in an immunized central Australian indigenous child. Since the widespread immunization for H. influenzae serotype b (Hib) in many indigenous peoples worldwide, there has been an increase in reported cases of Hia, postulating that this serotype is taking over the niche that Hib once occupied in indigenous populations.

  10. PCR deduction of invasive and colonizing pneumococcal serotypes from Venezuela: a critical appraisal.

    Science.gov (United States)

    Bello Gonzalez, Teresita; Rivera-Olivero, Ismar Alejandra; Sisco, María Carolina; Spadola, Enza; Hermans, Peter W; de Waard, Jacobus H

    2014-04-15

    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.

  11. Capsular Serotyping of Streptococcus pneumoniae by latex agglutination.

    Science.gov (United States)

    Porter, Barbara D; Ortika, Belinda D; Satzke, Catherine

    2014-09-25

    Latex agglutination reagents are widely used in microbial diagnosis, identification and serotyping. Streptococcus pneumoniae (the pneumococcus) is a major cause of morbidity and mortality world-wide. Current vaccines target the pneumococcal capsule, and there are over 90 capsular serotypes. Serotyping pneumococcal isolates is therefore important for assessing the impact of vaccination programs and for epidemiological purposes. The World Health Organization has recommended latex agglutination as an alternative method to the 'gold standard' Quellung test for serotyping pneumococci. Latex agglutination is a relatively simple, quick and inexpensive method; and is therefore suitable for resource-poor settings as well as laboratories with high-volume workloads. Latex agglutination reagents can be prepared in-house utilizing commercially-sourced antibodies that are passively attached to latex particles. This manuscript describes a method of production and quality control of latex agglutination reagents, and details a sequential testing approach which is time- and cost-effective. This method of production and quality control may also be suitable for other testing purposes.

  12. Immunoproteomic analysis of bacterial proteins of Actinobacillus pleuropneumoniae serotype 1

    Directory of Open Access Journals (Sweden)

    Wu Zongfu

    2011-06-01

    Full Text Available Abstract Background Actinobacillus pleuropneumoniae (APP is one of the most important swine pathogens worldwide. Identification and characterization of novel antigenic APP vaccine candidates are underway. In the present study, we use an immunoproteomic approach to identify APP protein antigens that may elicit an immune response in serotype 1 naturally infected swine and serotype 1 virulent strain S259-immunized rabbits. Results Proteins from total cell lysates of serotype 1 APP were separated by two-dimensional electrophoresis (2DE. Western blot analysis revealed 21 immunoreactive protein spots separated in the pH 4-7 range and 4 spots in the pH 7-11 range with the convalescent sera from swine; we found 5 immunoreactive protein spots that separated in the pH 4-7 range and 2 in the pH 7-11 range with hyperimmune sera from S259-immunized rabbits. The proteins included the known antigens ApxIIA, protective surface antigen D15, outer membrane proteins P5, subunit NqrA. The remaining antigens are being reported as immunoreactive proteins in APP for the first time, to our knowledge. Conclusions We identified a total of 42 immunoreactive proteins of the APP serotype 1 virulent strain S259 which represented 32 different proteins, including some novel immunoreactive factors which could be researched as vaccine candidates.

  13. Adhesion of Porphyromonas gingivalis serotypes to pocket epithelium

    NARCIS (Netherlands)

    Dierickx, K; Pauwels, M; Laine, ML; Van Eldere, J; Cassiman, JJ; van Winkelhoff, AJ; van Steenberghe, D; Quirynen, M

    2003-01-01

    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 o

  14. Urban epidemic of dengue virus serotype 3 infection, Senegal, 2009.

    Science.gov (United States)

    Faye, Ousmane; Ba, Yamar; Faye, Oumar; Talla, Cheikh; Diallo, Diawo; Chen, Rubing; Mondo, Mireille; Ba, Rouguiétou; Macondo, Edgard; Siby, Tidiane; Weaver, Scott C; Diallo, Mawlouth; Sall, Amadou Alpha

    2014-03-01

    An urban epidemic of dengue in Senegal during 2009 affected 196 persons and included 5 cases of dengue hemorrhagic fever and 1 fatal case of dengue shock syndrome. Dengue virus serotype 3 was identified from all patients, and Aedes aegypti mosquitoes were identified as the primary vector of the virus.

  15. Shigella flexneri serotype 1c derived from serotype 1a by acquisition of gtrIC gene cluster via a bacteriophage.

    Science.gov (United States)

    Tang, Swee-Seong; Carlin, Nils I A; Talukder, Kaisar A; Cam, Phung D; Verma, Naresh K

    2016-06-27

    Shigella spp. are the primary causative agents of bacillary dysentery. Since its emergence in the late 1980s, the S. flexneri serotype 1c remains poorly understood, particularly with regard to its origin and genetic evolution. This article provides a molecular insight into this novel serotype and the gtrIC gene cluster that determines its unique immune recognition. A PCR of the gtrIC cluster showed that serotype 1c isolates from different geographical origins were genetically conserved. An analysis of sequences flanking the gtrIC cluster revealed remnants of a prophage genome, in particular integrase and tRNA(Pro) genes. Meanwhile, Southern blot analyses on serotype 1c, 1a and 1b strains indicated that all the tested serotype 1c strains may have had a common origin that has since remained distinct from the closely related 1a and 1b serotypes. The identification of prophage genes upstream of the gtrIC cluster is consistent with the notion of bacteriophage-mediated integration of the gtrIC cluster into a pre-existing serotype. This is the first study to show that serotype 1c isolates from different geographical origins share an identical pattern of genetic arrangement, suggesting that serotype 1c strains may have originated from a single parental strain. Analysis of the sequence around the gtrIC cluster revealed a new site for the integration of the serotype converting phages of S. flexneri. Understanding the origin of new pathogenic serotypes and the molecular basis of serotype conversion in S. flexneri would provide information for developing cross-reactive Shigella vaccines.

  16. Serotype specificity of B-haplotype influence on the relative efficacy of Marek's disease vaccines.

    Science.gov (United States)

    Bacon, L D; Witter, R L

    1994-01-01

    B-haplotype genes in the chicken were previously shown to differentially influence vaccine efficacy against challenge with very virulent Marek's disease virus according to the type of Marek's disease (MD) vaccine used. To determine whether MD vaccines of the same serotype gave comparable levels of protection against MD in chickens of the same haplotype challenged with MD virus strain Md5, two serotype 1 and two serotype 2 vaccines were compared with one serotype 3 vaccine using chickens of 15-B-congenic lines. There was a strong correlation in development of MD lesions among chickens of the different lines receiving the two serotype 2 vaccines (r = 0.94) as well as among chickens receiving the two serotype 1 vaccines (r = 0.76). The serotype 1 vaccines were preferable for B2, B13, B15, and B21, but serotype 2 vaccines were more protective for B5 chickens. The two serotype 2 vaccines gave equivalent protection; however, of the serotype 1 vaccines, CVI988/Rispens provided more protection than Md11/75c/R2/23. We conclude that the B-haplotype influence on MD vaccine efficacy is dependent on the serotype of the vaccine.

  17. Prevalence of Salmonella serotypes isolated in Spain from human and non human sources (1983-1987).

    Science.gov (United States)

    Echeita, M A; Usera, M A

    1989-09-01

    Salmonella serotypes over a five year period were studied in order to know their prevalence in Spain. The Salmonella Reference Centre received a total of 17,612 strains from 1983-1987. The majority (16,133) were of human origin and only 1,479 strains were isolated from non-human sources. The serotyping yielded 100 different serotypes, Salmonella enterica serotype Enteritidis (8) being the commonest in both groups, 61.18% of human origin and 31.91% of non-human origin. Salmonella enterica serotype Typhimurium the commonest serotype in many countries, occupies second place in our results with the following percentages 11.87% and 9.67% respectively. Among the strains of human origin Salmonella enterica serotype Typhi occupies fourth place (3.24%). This is very low compared with the high number of clinically diagnosed typhoid fever cases declared in the country: over 5,000 cases per year.

  18. Temporal trends in invasive pneumococcal disease and pneumococcal serotypes over 7 decades

    DEFF Research Database (Denmark)

    Harboe, Zitta B; Benfield, Thomas; Valentiner-Branth, Palle

    2010-01-01

    BACKGROUND: Pneumococcal infections have historically played a major role in terms of morbidity and mortality. We explored historical trends of invasive pneumococcal disease (IPD) and pneumococcal serotypes in a population exposed to limited antibiotic selective pressure and conjugate pneumococcal...... of bacteremia cases. The incidence of meningitis remained relatively stable, with a median of 1.3 cases per 100,000 population (IQR, 0.9-1.6). The proportions of serotypes/groups 4 and 9 increased; the proportion of serotype 18C decreased; the proportions of serotypes 6, 7F, 14, and 23F remained stable......; and serotype 2 nearly disappeared. Before the 1960s, serotypes 1, 2, 3, and 5 presented peaks every 2-3 years, becoming less frequent during the 1970s with peaks every 7-10 years. Between 20% and 90% of IPD in children caused by PCV serotypes during the last 4 decades. Cases of IPD caused...

  19. PREVALENCE OF STREPTOCOCCUS PNEUMONIAE SEROTYPES OF THE HEPTAVALENT CONJUGATED VACCINE IN PEDIATRIC INFECTIONS

    Directory of Open Access Journals (Sweden)

    Elena Petraru

    2007-08-01

    Full Text Available Severe evolution of pneumococcal infections with multiresistant strains in children under 2 years of age determined the introduction, in some countries, of the heptavalent vaccine, which includes the most frequent capsular serotypes. The knowledge of serotypes circulating in our area is crucial for the introduction of such a vaccine in our country. We studied 202 pneumococcal strains; out of these, serologic identification of 172 strains established classification in 23 serotypes/15 serogroups; 24 strains were non-typable. 66,3% of isolates belong to serotypes 23F/23B, 6B/6A and 19F/19A. Only 54% of the serotypes isolated from children under 2 years of age are included in the heptavalent vaccine. Pneumococcal strains with high level resistance to beta-lactams and multiresistant to other antibiotics belong to the 2 most frequently isolated serotypes, 19A and 23B. Vaccinal serotypes 4 and 18C were not identified in our study.

  20. Serotype Distribution of Salmonella Isolates from Turkey Ground Meat and Meat Parts

    Directory of Open Access Journals (Sweden)

    Irfan Erol

    2013-01-01

    Full Text Available The aim of the study was to find out the serotype distribution of 169 Salmonella colonies recovered from 112 Salmonella positive ground turkey (115 colonies and 52 turkey meat parts (54 colonies. Out of 15 Salmonella serotypes: S. Corvallis, S. Kentucky, S. Bredeney, S. Virchow, S. Saintpaul and S. Agona were identified as the predominant serovars at the rates of 27%, 13%, 12%, 12%, 11%, and 10%, respectively. Other serotypes were below 6% of the total isolates. All S. Kentucky and S. Virchow and most of the S. Corvallis (39/46 and S. Heidelberg (9/9 serotypes were recovered from ground turkey. The results indicate that turkey ground meat and meat parts were contaminated with quite distinct Salmonella serotypes. This is the first study reporting Salmonella serotype distribution in turkey meat and S. Corvallis as predominant serotype in poultry meat in Turkey.

  1. The Cytolethal Distending Toxin Produced by Nontyphoidal Salmonella Serotypes Javiana, Montevideo, Oranienburg, and Mississippi Induces DNA Damage in a Manner Similar to That of Serotype Typhi

    Science.gov (United States)

    Miller, Rachel A.

    2016-01-01

    ABSTRACT Select nontyphoidal Salmonella enterica (NTS) serotypes were recently found to encode the Salmonella cytolethal distending toxin (S-CDT), an important virulence factor for serotype Typhi, the causative agent of typhoid fever. Using a PCR-based assay, we determined that among 21 NTS serotypes causing the majority of food-borne salmonellosis cases in the United States, genes encoding S-CDT are conserved in isolates representing serotypes Javiana, Montevideo, and Oranienburg but that among serotype Mississippi isolates, the presence of S-CDT-encoding genes is clade associated. HeLa cells infected with representative strains of these S-CDT-positive serotypes had a significantly higher proportion of cells arrested in the G2/M phase than HeLa cells infected with representative strains of S-CDT-negative serotypes Typhimurium, Newport, and Enteritidis. The G2/M cell cycle arrest was dependent on CdtB, the active subunit of S-CDT, as infection with isogenic ΔcdtB mutants abolished their ability to induce a G2/M cell cycle arrest. Infection with S-CDT-encoding serotypes was significantly associated with activation of the host cell’s DNA damage response (DDR), a signaling cascade that is important for detecting and repairing damaged DNA. HeLa cell populations infected with S-CDT-positive serotypes had a significantly higher proportion of cells with DDR protein 53BP1 and γH2AX foci than cells infected with either S-CDT-negative serotypes or isogenic ΔcdtB strains. Intoxication with S-CDT occurred via autocrine and paracrine pathways, as uninfected HeLa cells among populations of infected cells also had an activated DDR. Overall, we show that S-CDT plays a significant role in the cellular outcome of infection with NTS serotypes. PMID:27999166

  2. VP2-serotyped live-attenuated bluetongue virus without NS3/NS3a expression provided serotype-specific protection and enables DIVA.

    NARCIS (Netherlands)

    Feenstra, F.; Maris-Veldhuis, M.A.; Daus, F.J.; Tacken, M.G.J.; Moormann, R.J.M.; Gennip, van H.G.P.; Rijn, van P.A.

    2014-01-01

    Bluetongue virus (BTV) causes Bluetongue in ruminants and is transmitted by Culicoides biting midges. Vaccination is the most effective measure to control vector borne diseases; however, there are 26 known BTV serotypes showing little cross protection. The BTV serotype is mainly determined by genome

  3. The use of serotype 1-and serotype 3-specific polymerase chain reaction for the detection of Marek's disease virus in chickens

    DEFF Research Database (Denmark)

    Handberg, Kurt; Nielsen, Ole L.; Jørgensen, Poul Henrik

    2001-01-01

    A serotype 1- and serotype 3-specific detection of Marek's disease virus (MDV) by polymerase chain reaction (PCR) was developed. The sensitivity of the method when applied to cell culture grown virus was comparable with that of cultivation. The method was applied to various tissue samples from...

  4. Identification and characterization of a novel Shigella flexneri serotype Yv in China.

    Directory of Open Access Journals (Sweden)

    Qiangzheng Sun

    Full Text Available Shigella flexneri is the major cause of bacterial shigellosis in developing countries. S. flexneri is divided into at least 19 serotypes, the majority of which are modifications of the same basic O-antigen by glucosylation and/or O-acetylation of its sugar residues by phage encoded serotype-converting genes. Recently, a plasmid encoded phosphoethanolamine (PEtN modification of the O-antigen has been reported, which is responsible for the presence of the MASF IV-1 determinant and results in conversion of traditional serotypes X, 4a and Y to novel serotypes Xv, 4av and Yv, respectively. In this study, we characterized 19 serotype Yv strains isolated in China. A variant of the O-antigen phosphoethanolamine transferase gene opt (formerly called lpt-O carried by a pSFxv_2-like plasmid was found in serotype Yv strains, which specifies the phosphorylation pattern on the O-antigen of this serotype. For the majority of the O-antigen units, the PEtN modification occurs on Rha(III, while for a minority, modifications occur on both Rha(II and Rha(III. Serotype-specific gene detection and PFGE analysis suggested that these serotype Yv isolates were originated from serotypes Y, Xv and 2a by acquisition of an opt-carrying plasmid and/or inactivation of serotype-specific gene gtrII or gtrX. These data, combined with those of serotypes Xv and 4av reported earlier, demonstrate that the plasmid-encoded PEtN modification is an important serotype conversion mechanism in S. flexneri, in addition to glucosylation and O-acetylation.

  5. Study on Serotypes and Auxotypes of Neisseria Gonorrhoeae in Guangzhou

    Institute of Scientific and Technical Information of China (English)

    ZHENG Heping(郑和平); PAN Huiqing(潘慧清); HUANG Jinmei(黄进梅); ZENG Weiying(曾维英); WU Xingzhong(吴兴中); LIU Zhongqiu(刘仲秋)

    2002-01-01

    Objective: To investigate the serotypes and auxotypesdistribution of Neisseria gonorrhoeae in Guangzhou.Method: 131 strains of Neisseria gonorrhoeae wereserotyped by co-agglutination test and 108 strains wereauxotyped by La Scolea′s method.Results: Out of 131 strains of Neisseria gonorrhoeae ,87.8% (115/131) were WⅡ/WⅢ, while 9.9% (13/131) wereWI. The most important auxotypes were Proto, Pro and ILe,42.6% (46/108), 21.3% (23/108) and 12.0%, respectively. WⅡ/WⅢ was distributed among the all auxotypes aboveand WI found only in both Proto and Pro.Conclusion: The study illustrated the prevailing serotype,WⅡ/WⅢ, and higher prevalence of Ile- in Guangzhou.

  6. Inflammatory Responses to Salmonella Infections Are Serotype-Specific

    Directory of Open Access Journals (Sweden)

    Zhanna Ktsoyan

    2013-01-01

    Full Text Available The main purpose of this study was to investigate the profile of inflammatory response in patients with acute salmonellosis caused by two serotypes of Salmonella enterica, S. Enteritidis and S. Typhimurium, as well as in convalescent patients with previous acute disease caused by S. Enteritidis. Patients with acute disease showed significantly elevated levels of IL-1β, IL-17, IL-10, and calprotectin compared to healthy control subjects. In convalescent patients, these markers were also significantly elevated, with the exception of IL-1β. Multivariate statistical analyses with the use of these variables produced models with a good predictive accuracy resulting in excellent separation of the diseased and healthy cohorts studied. Overall, the results suggest that the profile of inflammatory response in this disease is determined, to a significant degree, by the serotype of Salmonella, and the profile of certain cytokines and calprotectin remains abnormal for a number of months following the acute disease stage.

  7. Imported dengue virus serotype 1 from Madeira to Finland 2012.

    Science.gov (United States)

    Huhtamo, E; Korhonen, Em; Vapalahti, O

    2013-02-21

    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.

  8. Increasing quinolone resistance in Salmonella enterica serotype enteritidis

    DEFF Research Database (Denmark)

    Mølbak, K.; Gerner-Smidt, P.; Wegener, Henrik Caspar

    2002-01-01

    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....

  9. Penicillin resistance and serotyping of Streptococcus pneumoniae in Latin America.

    Science.gov (United States)

    Camargos, Paulo; Fischer, Gilberto Bueno; Mocelin, Helena; Dias, Cícero; Ruvinsky, Raúl

    2006-09-01

    Streptococcus pneumoniae (Strep. pneumoniae) is the main cause of bacterial pneumonia in children less than 5 years of age, with high mortality rates in developing countries. In 1993, the Regional System for Vaccines Group (SIREVA) of the pan-American Health Organisation (PAHO) began a study involving six Latin American countries to identify serotypes and their representativity in the new conjugated vaccines, and to determine the degree of resistance to penicillin. Serotypes 14 (highest resistance level), 5, 1, 6A/B, 23F, 7F, 9V, 19F, 18C, 19A, 9N, were prevalent in the region, with some differences among countries. Although resistance to penicillin ranged from 2% (Brazil) to 21.1% (Mexico), studies have shown that pneumonia caused by Strep. pneumoniae with diminished sensitivity to penillin can be treated with this antibiotic. Only 58% of the serotypes isolated in the region studied were represented in the seven-valent vaccine. Continual surveillance is essential to determine which formulation of conjugated vaccine will be suitable for use in Latin America.

  10. Serotype Chimeric Human Adenoviruses for Cancer GeneTherapy

    Directory of Open Access Journals (Sweden)

    Akseli Hemminki

    2010-09-01

    Full Text Available Cancer gene therapy consists of numerous approaches where the common denominator is utilization of vectors for achieving therapeutic effect. A particularly potent embodiment of the approach is virotherapy, in which the replication potential of an oncolytic virus is directed towards tumor cells to cause lysis, while normal cells are spared. Importantly, the therapeutic effect of the initial viral load is amplified through viral replication cycles and production of progeny virions. All cancer gene therapy approaches rely on a sufficient level of delivery of the anticancer agent into target cells. Thus,enhancement of delivery to target cells, and reduction of delivery to non-target cells, in an approach called transductional targeting, is attractive. Both genetic and non-genetic retargeting strategies have been utilized. However, in the context of oncolytic viruses, it is beneficial to have the specific modification included in progeny virions and hence genetic modification may be preferable. Serotype chimerism utilizes serotype specific differences in receptor usage, liver tropism and seroprevalence in order to gain enhanced infection of target tissue. This review will focus on serotype chimeric adenoviruses for cancer gene therapy applications.

  11. Advances in Molecular Serotyping and Subtyping of Escherichia coli

    Directory of Open Access Journals (Sweden)

    Pina M. Fratamico

    2016-05-01

    Full Text Available E. coli plays an important role as a member of the gut microbiota; however, pathogenic strains also exist, including various diarrheagenic E. coli pathotypes and extraintestinal pathogenic E. coli that cause illness outside of the GI-tract. E. coli have traditionally been serotyped using antisera against the ca. 186 O-antigens and 53 H-flagellar antigens. Phenotypic methods, including bacteriophage typing and O- and H- serotyping for differentiating and characterizing E. coli have been used for many years; however, these methods are generally time consuming and not always accurate. Advances in next generation sequencing technologies have made it possible to develop genetic-based subtyping and molecular serotyping methods for E. coli, which are more discriminatory compared to phenotypic typing methods. Furthermore, whole genome sequencing (WGS of E. coli is replacing established subtyping methods such as pulsed-field gel electrophoresis (PFGE, providing a major advancement in the ability to investigate food-borne disease outbreaks and for trace-back to sources. A variety of sequence analysis tools and bioinformatic pipelines are being developed to analyze the vast amount of data generated by WGS and to obtain specific information such as O- and H-group determination and the presence of virulence genes and other genetic markers.

  12. The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 15.

    Science.gov (United States)

    Ito, Hiroya; Sueyoshi, Masuo

    2015-04-01

    Nucleotide sequence determination and analysis of the cps gene involved in the capsular polysaccharide biosynthesis of Actinobacillus pleuropneumoniae serotype 15 revealed the presence of three open reading frames, designated as cps15ABC genes. At the protein level, Cps15A and Cps15B showed considerably high homology to CpsA (67.0 to 68.7%) and CpsB (31.7 to 36.8%), respectively, of A. pleuropneumoniae serotypes 1, 4 and 12, revealing the common genetic organization of the cps among serotypes 1, 4, 12 and 15. However, Cps15C showed no homology to any proteins of A. pleuropneumoniae serotypes, indicating that cps15C may be specific to serotype 15. This study will provide the basic molecular knowledge necessary for the development of diagnostics and a vaccine for A. pleuropneumoniae serotype 15.

  13. [Identification of rotavirus associated to serotype G2 in Yucatan, Mexico].

    Science.gov (United States)

    Gonzales-Loza, M del R; Polanco-Marín, G G; Puerto-Solis, M

    2000-01-01

    In the present study, rotavirus G2 serotype was identified from fecal samples of children with gastroenteritis from the city of Merida, Yucatan, Mexico. Virological diagnosis of disease was performed using polycrylamide gel electrophoresis and immunoenzymatic assay. Out of 149 analyzed samples 25 (16.7%) gave positive reaction to rotavirus groups A, of these 23 (92%) were identified as serotype g2, subgroup i and electrophoretic short pattern, whereas 2 (8%) were identified as subgroups II and electrophoretic long pattern, however, the G serotype was not possible to determine. Rotavirus G serotype has not been detected in more than 90% of samples since 1985. This indicates that the number of people susceptible to G2 serotype within the population has increased over recent years, which perhaps indicates that an important outbreak of acute infectious diarrhea caused by the rotavirus G2 serotype may be forthcoming.

  14. Emergence of group B Streptococcus serotype IV in women of child-bearing age in Ireland.

    LENUS (Irish Health Repository)

    Kiely, R A

    2011-02-01

    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.

  15. Molecular diagnosis of non-serotypeable Shigella spp.: problems and prospects.

    Science.gov (United States)

    Muthuirulandi Sethuvel, Dhiviya Prabaa; Devanga Ragupathi, Naveen Kumar; Anandan, Shalini; Walia, Kamini; Veeraraghavan, Balaji

    2017-02-01

    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.

  16. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    Directory of Open Access Journals (Sweden)

    Alvaro Díaz-Badillo

    2014-04-01

    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.

  17. A DNA Microarray-Based Assay to Detect Dual Infection with Two Dengue Virus Serotypes

    Science.gov (United States)

    Díaz-Badillo, Alvaro; de Lourdes Muñoz, María; Perez-Ramirez, Gerardo; Altuzar, Victor; Burgueño, Juan; Mendoza-Alvarez, Julio G.; Martínez-Muñoz, Jorge P.; Cisneros, Alejandro; Navarrete-Espinosa, Joel; Sanchez-Sinencio, Feliciano

    2014-01-01

    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. PMID:24776933

  18. Comparative genomic analysis of Vibrio parahaemolyticus: serotype conversion and virulence

    Directory of Open Access Journals (Sweden)

    Gil Ana I

    2011-06-01

    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

  19. First report of an outbreak of pneumonia caused by Streptococcus pneumoniae serotype 6A.

    Science.gov (United States)

    Prebil, Karla; Beović, Bojana; Paragi, Metka; Seme, Katja; Kastrin, Tamara; Plesničar, Blanka Kores; Petek, Bojana; Martinčič, Žiga

    2016-01-01

    Five patients in a geropsychiatric unit of a psychiatric hospital became abruptly ill with pneumonia caused by Streptococcus pneumoniae serotype 6A. Four other residents were colonized with the same serotype, which has previously not been reported in association with pneumonia outbreaks. Furthermore, serotype 6A is not included in all vaccine types, which may be important for the choice of vaccine in some settings. All isolates showed identical pulsed-field gel electrophoresis restriction patterns.

  20. Complete genome sequence of Streptococcus mutans GS-5, a serotype c strain.

    Science.gov (United States)

    Biswas, Saswati; Biswas, Indranil

    2012-09-01

    Streptococcus mutans, a principal causative agent of dental caries, is considered to be the most cariogenic among all oral streptococci. Of the four S. mutans serotypes (c, e, f, and k), serotype c strains predominate in the oral cavity. Here, we present the complete genome sequence of S. mutans GS-5, a serotype c strain originally isolated from human carious lesions, which is extensively used as a laboratory strain worldwide.

  1. Complete Genome Sequence of Streptococcus mutans GS-5, a Serotype c Strain

    OpenAIRE

    Biswas, Saswati; Biswas, Indranil

    2012-01-01

    Streptococcus mutans, a principal causative agent of dental caries, is considered to be the most cariogenic among all oral streptococci. Of the four S. mutans serotypes (c, e, f, and k), serotype c strains predominate in the oral cavity. Here, we present the complete genome sequence of S. mutans GS-5, a serotype c strain originally isolated from human carious lesions, which is extensively used as a laboratory strain worldwide.

  2. Real-time quantitative PCR for detection and identification of Actinobacillus pleuropneumoniae serotype 2

    Directory of Open Access Journals (Sweden)

    Dors Arkadiusz

    2016-09-01

    Full Text Available Introduction: Porcine pleuropneumonia inflicts important economic losses on most commercial herds. Detection of subclinical or chronic infection in animals still remains a challenge, as isolation and identification of A. pleuropneumoniae serotypes is difficult and quantification of the bacteria on agar plates is often almost impossible. The aim of the study was to develop and evaluate a serotype-specific quantitative TaqMan probe-based PCR for detection of serotype 2 in pig lungs, tonsils, and nasal swabs.

  3. Serologic analysis of human rotavirus serotypes P1A and P2 by using monoclonal antibodies.

    Science.gov (United States)

    Padilla-Noriega, L; Werner-Eckert, R; Mackow, E R; Gorziglia, M; Larralde, G; Taniguchi, K; Greenberg, H B

    1993-01-01

    Three human rotavirus (HRV) VP4 serotypes and one subtype have been described on the basis of a fourfold or an eightfold-or-greater difference in neutralization titer when tested with hyperimmune antisera to recombinant VP4 or VP8* (serotypes P1A, P1B, P2, and P3). To start to analyze the antigenic basis underlying serotype specificity, we produced a library of 13 VP4-specific neutralizing monoclonal antibodies (NMAbs) to two HRVs, the serotype P1A strain Wa and the serotype P2 strain ST3, and characterized the reactivity of these NMAbs with a panel of serotypically diverse HRV strains by neutralization assay and enzyme-linked immunosorbent assay (ELISA). We characterized the serotypic specificity of the NMAbs by using a fourfold or an eightfold-or-greater difference in titer against the homologous (i.e., immunogen) and heterologous strains as a criterion for serotype. Some ST3-derived NMAbs reacted specifically with serotype P2 HRVs by ELISA and/or neutralization assay, while some Wa-derived NMAbs reacted specifically by ELISA and/or neutralization assay with some or all serotype P1A HRVs. Other Wa- and ST3-derived NMAbs reacted with some or all serotype P1A and P2 HRV strains by neutralization assay and ELISA. Most NMAbs did not react with serotype P1B or P3 strains. In previous studies, three distinct operationally defined epitopes have been identified on VP4 by examining the reactivity patterns of selected antigenic variants of HRV strain KU. At least one of the NMAbs described here recognizes an epitope unrelated to these previously identified epitopes, since it neutralized both KU and its variants. Images PMID:7681440

  4. Molecular analysis of multiple isolates of the major serotypes of group B streptococci.

    OpenAIRE

    Fasola, E; Livdahl, C; Ferrieri, P

    1993-01-01

    Serotyping of clinical isolates is a widely used technique for epidemiologic study of group B streptococcal infections. However, serotyping cannot definitively determine epidemiologically related or unrelated isolates. We investigated the use of restriction endonuclease analysis (REA) with both conventional agarose gel electrophoresis (AGE) and pulsed-field gel electrophoresis (PFGE) in 50 isolates of the major serotypes of group B streptococci. Single digestion with HindIII and HaeIII and do...

  5. Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998–2008

    OpenAIRE

    Jackson, Brendan R.; Griffin, Patricia M.; Cole, Dana; Walsh, Kelly A.; Chai, Shua J.

    2013-01-01

    Salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. To clarify links between Salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998–2008. More than 80% of outbreaks caused by serotypes Enteritidis, Heidelberg, and Hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes Javiana...

  6. Molecular serotyping of rough Salmonella strains isolated from Danish pork production

    DEFF Research Database (Denmark)

    Löfström, Charlotta; Boel, Jeppe; Sisic, E.;

    2013-01-01

    for subtyping is necessary and serotyping is one of the most commonly used approaches for Salmonella. Traditionally, serotyping is done by slide agglutination using antisera aiming at two cell surface antigens: somatic (O) lipopolysaccharides (LPS) and flagellar (H). Some Salmonella strains have incomplete LPS...... structures, referred to as rough strains, or do not express H antigens, therefore serotyping by agglutination cannot be performed on these isolates. This results in data gaps when subtyping data is needed. To overcome this obstacle, serotypes can be determined on DNA level, i.e. by determining the presence...

  7. Around the World in 1,475 Salmonella Geo-serotypes

    Science.gov (United States)

    Le Hello, Simon; de Jong, Birgitta; Rolfhamre, Per; Faensen, Daniel; Weill, François-Xavier; Giesecke, Johan

    2016-01-01

    It’s easy to remember Salmonella serotypes names, isn’t it? Surely, this is because the naming system of Salmonella serotypes is by far the most scientist friendly. Traditionally, most Salmonella serotypes have been named after geographic locations. We decided to explore the geographic locations to which Salmonella serotypes refer and describe some unexpected twists in the naming scheme. We found that 93% (n = 1,475) of the 1,585 serotypes could be categorized as geo-serotypes; that is, the name refers to a geographic location. The 3 countries with the most geo-serotypes are Germany, the United Kingdom, and the United States. Other serotype names refer to the name of a person, animal, tribe, or food item or are a composite of symptoms and host. The Salmonella serotypes naming scheme has had a valuable effect on public health microbiology, and in the current era of fast development of whole-genome sequencing, it should remain a reference.

  8. [Isolation of Haemophilus influenzae serotypes from deep sites in sick children].

    Science.gov (United States)

    Gatti, B M; Ramirez Gronda, G A; Etchevarría, M; Vescina, C M; Varea, A M; González Ayala, S E

    2004-01-01

    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.

  9. Streptococcus agalactiae Serotype Distribution and Antimicrobial Susceptibility in Pregnant Women in Gabon, Central Africa.

    Science.gov (United States)

    Belard, Sabine; Toepfner, Nicole; Capan-Melser, Mesküre; Mombo-Ngoma, Ghyslain; Zoleko-Manego, Rella; Groger, Mirjam; Matsiegui, Pierre-Blaise; Agnandji, Selidji T; Adegnika, Ayôla A; González, Raquel; Kremsner, Peter G; Menendez, Clara; Ramharter, Michael; Berner, Reinhard

    2015-11-25

    Neonatal invasive disease due to Streptococcus agalactiae is life threatening and preventive strategies suitable for resource limited settings are urgently needed. Protective coverage of vaccine candidates based on capsular epitopes will relate to local epidemiology of S. agalactiae serotypes and successful management of critical infections depends on timely therapy with effective antibiotics. This is the first report on serotype distribution and antimicrobial susceptibility of S. agalactiae in pregnant women from a Central African region. Serotypes V, III, and Ib accounted for 88/109 (81%) serotypes and all isolates were susceptible to penicillin and clindamycin while 13% showed intermediate susceptibility to erythromycin.

  10. Outbreak-associated Salmonella enterica serotypes and food Commodities, United States, 1998-2008.

    Science.gov (United States)

    Jackson, Brendan R; Griffin, Patricia M; Cole, Dana; Walsh, Kelly A; Chai, Shua J

    2013-08-01

    Salmonella enterica infections are transmitted not only by animal-derived foods but also by vegetables, fruits, and other plant products. To clarify links between Salmonella serotypes and specific foods, we examined the diversity and predominance of food commodities implicated in outbreaks of salmonellosis during 1998-2008. More than 80% of outbreaks caused by serotypes Enteritidis, Heidelberg, and Hadar were attributed to eggs or poultry, whereas >50% of outbreaks caused by serotypes Javiana, Litchfield, Mbandaka, Muenchen, Poona, and Senftenberg were attributed to plant commodities. Serotypes Typhimurium and Newport were associated with a wide variety of food commodities. Knowledge about these associations can help guide outbreak investigations and control measures.

  11. Clonal relationship of recent invasive Haemophilus influenzae serotype f isolates from Denmark and the United States

    DEFF Research Database (Denmark)

    Bruun, B; Gahrn-Hansen, B; Westh, H

    2004-01-01

    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...... % of cases, but meningitis, epiglottitis and osteoarthritis were also seen. Recent Danish isolates were compared to recent American isolates, historical Hif strains and non-Hif invasive strains. Results of conventional serotyping were confirmed by PCR detection of the serotype-f-specific cap and bexA gene...

  12. Molecular detection assay of five Salmonella serotypes of public interest: Typhimurium, Enteritidis, Newport, Heidelberg, and Hadar.

    Science.gov (United States)

    Bugarel, M; Tudor, A; Loneragan, G H; Nightingale, K K

    2017-03-01

    Foodborne illnesses due to Salmonella represent an important public-health concern worldwide. In the United States, a majority of Salmonella infections are associated with a small number of serotypes. Furthermore, some serotypes that are overrepresented among human disease are also associated with multi-drug resistance phenotypes. Rapid detection of serotypes of public-health concern might help reduce the burden of salmonellosis cases and limit exposure to multi-drug resistant Salmonella. We developed a two-step real-time PCR-based rapid method for the identification and detection of five Salmonella serotypes that are either overrepresented in human disease or frequently associated with multi-drug resistance, including serotypes Enteritidis, Typhimurium, Newport, Hadar, and Heidelberg. Two sets of four markers were developed to detect and differentiate the five serotypes. The first set of markers was developed as a screening step to detect the five serotypes; whereas, the second set was used to further distinguish serotypes Heidelberg, Newport and Hadar. The utilization of these markers on a two-step investigation strategy provides a diagnostic specificity of 97% for the detection of Typhimurium, Enteritidis, Heidelberg, Infantis, Newport and Hadar. The diagnostic sensitivity of the detection makers is >96%. The availability of this two-step rapid method will facilitate specific detection of Salmonella serotypes that contribute to a significant proportion of human disease and carry antimicrobial resistance.

  13. [Serotype distribution of Streptococcus pneumoniae isolated from invasive infections at the Hospital de Niños of Santa Fe].

    Science.gov (United States)

    Mayoral, C; Baroni, M R; Giani, R; Virgolini, S; Zurbriggen, L; Regueira, M

    2008-01-01

    The serotype distribution of Streptococcus pneumoniae varies through time. The introduction of pneumococcal conjugate vaccines showed a decreased prevalence of pneumococcal invasive isolates belonging to serotype 14 and an increase of serotypes not therein included. In 1993, the Hospital de Niños of Santa Fe began surveillance of the serotype distribution of invasive S. pneumoniae disease. In the period 2003-2005, 76 isolates were analysed by studying the correlation between serotype and pathology, age and MIC of penicillin. Serotype 14 was the most frequent followed by serotypes 1, 6B, 18C, 7F, 19 F and 5. Serotype 14 showed a statistically significant correlation with MICs of penicillin ranging from 0,5 to 2 mg/l. Although this serotype was more frequently observed in pneumonia than in meningitis, there was not a significant association with any particular pathology. Serotypes 14 and 1, were prevalent among children under and over 2 years old, respectively. Most of these isolates with MICs of penicillin = 2 mg/l, were from patients with pneumonia and not with meningitis. The serotype distribution was similar to that during the period 1993-99, with the exception of serotypes 18C, 4, 12F and 22F which had never been found before. The emergence of these serotypes makes it essential to continue surveillance to determine which conjugated vaccine formulation would be suitable to prevent the most frequent pneumococcal invasive infections.

  14. A comparison of machine learning and Bayesian modelling for molecular serotyping.

    Science.gov (United States)

    Newton, Richard; Wernisch, Lorenz

    2017-08-11

    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

  15. Serotype Specific Invasive Capacity and Persistent Reduction in Invasive Pneumococcal Disease

    Science.gov (United States)

    Yildirim, Inci; Hanage, William P.; Lipsitch, Marc; Shea, Kimberly M.; Stevenson, Abbie; Finkelstein, Jonathan; Huang, Susan S.; Lee, Grace M.; Kleinman, Ken; Pelton, SI

    2011-01-01

    Defining the propensity of Streptoccocus pneumoniae (SP) serotypes to invade sterile body sites following nasopharyngeal (NP) acquisition has the potential to inform about how much invasive pneumococcal disease (IPD) may occur in a typical population with a given distribution of carriage serotypes. Data from enhanced surveillance for IPD in Massachusetts children ≤7 years in 2003/04, 2006/07 and 2008/09 seasons and surveillance of SP NP carriage during the corresponding respiratory seasons in 16 Massachusetts communities in 2003/04 and 8 of the 16 communities in both 2006/07 and 2008/09 were used to compute a serotype specific “invasive capacity (IC)” by dividing the incidence of IPD due to serotype x by the carriage prevalence of that same serotype in children of the same age. A total of 206 IPD and 806 NP isolates of SP were collected during the study period. An approximate 50-fold variation in the point estimates between the serotypes having the highest (18C, 33F, 7F, 19A, 3 and 22F) and lowest (6C, 23A, 35F, 11A, 35B, 19F, 15A, and 15BC) IC was observed. Point estimates of IC for most of the common serotypes currently colonizing children in Massachusetts were low and likely explain the continued reduction in IPD from the pre-PCV era in the absence of specific protection against these serotypes. Invasive capacity differs among serotypes and as new pneumococcal conjugate vaccines are introduced, ongoing surveillance will be essential to monitor whether serotypes with high invasive capacity emerge (e.g. 33F, 22F) as successful colonizers resulting in increased IPD incidence due to replacement serotypes. PMID:21029807

  16. Transmission dynamics of two dengue serotypes with vaccination scenarios.

    Science.gov (United States)

    González Morales, N L; Núñez-López, M; Ramos-Castañeda, J; Velasco-Hernández, J X

    2017-05-01

    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.

  17. Clonal and serotype dynamics of serogroup 6 isolates causing invasive pneumococcal disease in Portugal: 1999-2012

    Science.gov (United States)

    Diamantino-Miranda, Jorge; Aguiar, Sandra Isabel; Carriço, João André; Melo-Cristino, José

    2017-01-01

    Although serogroup 6 was among the first to be recognized among Streptococcus pneumoniae, several new serotypes were identified since the introduction of pneumococcal conjugate vaccines (PCVs). A decrease of the 6B-2 variant among invasive pneumococcal disease (IPD), but not 6B-1, was noted post conjugate vaccine introduction, underpinned by a decrease of CC273 isolates. Serotype 6C was associated with adult IPD and increased in this age group representing two lineages (CC315 and CC395), while the same lineages expressed other serogroup 6 serotypes in children. Taken together, these findings suggest a potential cross-protection of PCVs against serotype 6C IPD among vaccinated children but not among adults. Serotype 6A became the most important serogroup 6 serotype in children but it decreased in adult IPD. No other serogroup 6 serotypes were detected, so available phenotypic or simple genotypic assays remain adequate for distinguishing serotypes within serogroup 6 isolates. PMID:28152029

  18. Identification of Actinobacillus pleuropneumoniae serotypes 1, 7, and 12 by multiplex PCR based on genes involved in encapsulation

    DEFF Research Database (Denmark)

    Angen, Øystein; Jessing, Stine Graakjær; Ahrens, Peter;

    2005-01-01

    Based on differences in the capsular polysaccharides, 15 serotypes have until now been described for Actinobacillus pleuropneumoniae, the etiological agent of swine pleuropneumonia. Identification of the causative serotype is important both as a virulence marker and for epidemiological purposes. ...

  19. Comparative sequence analyses of the neurotoxin complex genes in Clostridium botulinum serotypes A, B, E, and F

    Directory of Open Access Journals (Sweden)

    Ajay K. Singh

    2012-09-01

    Full Text Available Neurotoxin complex (NTC genes are arranged in two known hemagglutinin (HA and open reading frame X (ORFX clusters. NTC genes have been analyzed in four serotypes A, B, E and F of Clostridium botulinum causing human botulism. Analysis of amino acid sequences of NT genes demonstrated significant differences among subtypes and four serotypes. Phylogram tree of NT genes reveals that serotypes A1 and B1 are much closer compared to serotype E1 and F1. However, non-toxic non-hemagglutinin (NTNH gene is highly conserved among four serotypes. Analysis of phylogram tree of NTNH gene reveals that serotypes A and F are more closely related compared to serotype B and E. Additionally, sequences of HAs and ORFX genes are very divergent but these genes are specific in subtypes and serotypes of Clostridium botulinum. Information derived from sequence analyses of NTC has direct implication in development of detection tools and therapeutic countermeasures for botulism.

  20. The Widespread Multidrug-Resistant Serotype O12 Pseudomonas aeruginosa Clone Emerged through Concomitant Horizontal Transfer of Serotype Antigen and Antibiotic Resistance Gene Clusters

    DEFF Research Database (Denmark)

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Freschi, Luca;

    2015-01-01

    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 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 conclusion, serotype switching in combination with acquisition of an antibiotic resistance determinant most likely contributed to the dissemination of the O12 serotype in clinical settings. Infection rates in hospital settings by multidrug-resistant (MDR) Pseudomonas aeruginosa clones have increased during...

  1. Assignment of serotype to Salmonella enterica isolates obtained from poultry and their environment in Southern Brazil.

    Science.gov (United States)

    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...

  2. A Serotype VIII Strain among Colonizing Group B Streptococcal Isolates in Boston, Massachusetts

    OpenAIRE

    Paoletti, Leanne J.; Bradford, Jessica; Paoletti, Lawrence C.

    1999-01-01

    Maternal colonization with group B Streptococcus (GBS) is a risk factor for neonatal GBS disease. Whereas serotypes Ia, Ib, II, III, and V are prevalent in the United States, types VI and VIII predominate in Japan. Recently, a serotype VIII strain was detected among 114 clinical GBS isolates from a Boston, Mass., hospital.

  3. An easy method for detection of nasopharyngeal carriage of multiple Streptococcus pneumoniae serotypes

    DEFF Research Database (Denmark)

    Kaltoft, Margit S.; Sørensen, Uffe; Slotved, Hans-Christian

    2008-01-01

    care centres. Pneumococci were observed in 363 samples and 36 of these (9.9%) contained more than one serotype (multiple carriages). Two persons carried 3 different serotypes simultaneously. A significant increase in the positive sampling rate (5.8%) was achieved by using the simplified method compared...

  4. Draft Genome Sequences of Streptococcus agalactiae Serotype Ia and III Isolates from Tilapia Farms in Thailand.

    Science.gov (United States)

    Areechon, Nontawith; Kannika, Korntip; Hirono, Ikuo; Kondo, Hidehiro; Unajak, Sasimanas

    2016-03-24

    Streptococcus agalactiaeserotypes Ia and III were isolated from infected tilapia in cage and pond culture farms in Thailand during 2012 to 2014, in which pathogenicity analysis demonstrated that serotype III showed higher virulence than serotype Ia. Here, we report the draft genome sequencing of piscineS. agalactiaeserotypes Ia and III.

  5. Virulence of six capsular serotypes of Porphyromonas gingivalis in a mouse model

    NARCIS (Netherlands)

    Laine, ML; van Winkelhoff, AJ

    1998-01-01

    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 wit

  6. Clonal relationship of recent invasive Haemophilus influenzae serotype f isolates from Denmark and the United States

    DEFF Research Database (Denmark)

    Bruun, B; Gahrn-Hansen, B; Westh, H;

    2004-01-01

    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...

  7. Serotype classification of Streptococcus mutans and its detection outside the oral cavity.

    Science.gov (United States)

    Nakano, Kazuhiko; Ooshima, Takashi

    2009-09-01

    Streptococcus mutans, generally known as a major pathogen of dental caries, is also a possible causative agent of bacteremia and infective endocarditis. S. mutans is classified into serotypes c, e, f and k based on the chemical composition of serotype-specific polysaccharides, with approximately 70-80% of strains found in the oral cavity classified as serotype c, followed by e (approximately 20%), and f and k (less than 5% each). Serotype k was recently designated as a novel serotype and shown to possess unique features, the most prominent being a defect of the glucose side chain in serotype-specific rhamnose-glucose polymers, which is related to a higher incidence of detection in cardiovascular specimens, owing to phagocytosis resistance. Molecular analyses of cardiovascular specimens showed a high detection frequency for S. mutans DNA, among which the detection rate for serotype k was quite high. These findings suggest that serotype k S. mutans possibly has a high level of virulence for systemic diseases.

  8. A molecular scheme for Yersinia enterocolitica patho-serotyping derived from genome-wide analysis.

    Science.gov (United States)

    Garzetti, Debora; Susen, Rosa; Fruth, Angelika; Tietze, Erhard; Heesemann, Jürgen; Rakin, Alexander

    2014-05-01

    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.

  9. Serotype-Specific Effect of Influenza on Adult Invasive Pneumococcal Pneumonia

    Science.gov (United States)

    Weinberger, Daniel M.; Harboe, Zitta B.; Viboud, Cécile; Krause, Tyra G.; Miller, Mark; Mølbak, Kåre; Konradsen, Helle B.

    2013-01-01

    Background. Influenza affects host susceptibility to pneumococcus. We sought to evaluate whether this relationship varies by pneumococcal serotype using a large epidemiological database covering 3 decades. Methods. Weekly rates of invasive pneumococcal pneumonia (IPP) were obtained from the Danish National Laboratory Surveillance System, and influenza-like illness (ILI) data were collected from Danish sentinel surveillance, Statens Serum Institut, 1977–2007. We fit Poisson regression models for each age and comorbidity group, with predictors for seasonality and secular changes, ILI activity, and serotype. Results. Among individuals with low levels of comorbidities, influenza had the largest impact on IPP incidence among low-invasiveness serotypes (influenza attributable percent: 17.9%, 95% confidence interval [CI], 13.6–21.9) as compared with high-invasiveness serotypes (6.7%, 95% CI, 3.8%–11.7%). Among those with higher levels of comorbidities, the effect of influenza was smaller, but high-invasiveness serotypes increased more than low-invasiveness serotypes (8.9% [95% CI, 6.6–11.8] vs 1.3% [95% CI, −1.6–5.4]. Conclusions. Influenza was associated with the greatest increases in the incidence of disease caused by serotypes with lower invasive potential and among individuals with low levels of comorbid conditions. The importance of influenza for adult IPP varies by serotype and host comorbidity. PMID:23901093

  10. Meningitis Associated with Simultaneous Infection by Multiple Dengue Virus Serotypes in Children, Brazil

    Science.gov (United States)

    Marinho, Paula Eillanny Silva; Bretas de Oliveira, Danilo; Candiani, Talitah Michel Sanchez; Crispim, Ana Paula Correia; Alvarenga, Pedro Paulo Martins; Castro, Fabrizia Cristina dos Santos; Abrahão, Jonatas Santos; Rios, Maria; Coimbra, Roney Santos

    2017-01-01

    To determine the causes of viral meningitis, we analyzed 22 cerebrospinal fluid samples collected during the 2014–2015 dengue epidemics in Brazil. We identified 3 serotypes of dengue virus (DENV-1, -2, and -3), as well as co-infection with 2 or 3 serotypes. We also detected the Asian II genotype of DENV-2. PMID:27983492

  11. EFSA Panel on Animal Health and Welfare (AHAW); Scientific Opinion on bluetongue serotype 8

    DEFF Research Database (Denmark)

    Bøtner, Anette; Oura, Chris; Saegerman, Claude

    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...

  12. Differential effects of viroporin inhibitors against feline infectious peritonitis virus serotypes I and II.

    Science.gov (United States)

    Takano, Tomomi; Nakano, Kenta; Doki, Tomoyoshi; Hohdatsu, Tsutomu

    2015-05-01

    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.

  13. Comparison of capsular genes of Streptococcus pneumoniae serotype 6A, 6B, 6C, and 6D isolates.

    Science.gov (United States)

    Song, Jae-Hoon; Baek, Jin Yang; Ko, Kwan Soo

    2011-05-01

    Recently, Streptococcus pneumoniae serotypes 6C and 6D have been identified. It is thought that they emerged by the replacement of wciN(β) in the capsular loci of serotypes 6A and 6B, respectively. However, their evolution has not been unveiled yet. To investigate the evolution of four serotypes of S. pneumoniae serogroup 6, four genes of the capsular polysaccharide synthesis (cps) locus, wchA, wciN, wciO, and wciP, of isolates of S. pneumoniae serotypes 6A, 6B, 6C, and 6D were sequenced. Multilocus sequence typing (MLST) was performed to investigate their genetic backgrounds. The wchA gene of serotype 6C and 6D isolates was distinct from that of serotype 6A and 6B isolates, which may suggest cotransfer of wchA with wciN(β). Otherwise, serotypes 6C and 6D displayed different genetic backgrounds from serotypes 6A and 6B, which was suggested by MLST analysis. In addition, serotype 6C isolates showed distinct wciP polymorphisms from other serotypes, which also indicated that serotype 6C had not recently originated from serotype 6A. Although serotype 6D shared the same amino acid polymorphisms of wciO with serotype 6B, wciP of serotype 6D differed from that of serotype 6B. The data indicate the implausibility of the scenario of a recent emergence of the cps locus of serotype 6D by genetic recombination between serotypes 6B and 6C. In addition, five serotype 6A and 6B isolates (6X group) displayed cps loci distinct from those of other isolates. The cps locus homogeneity and similar sequence types in MLST analysis suggest that most of the 6X group of isolates originated from the same ancestor and that the entire cps locus might have recently been transferred from an unknown origin. Serotype 6B isolates showed two or more cps locus subtypes, indicating a recombination-mediated mosaic structure of the cps locus of serotype 6B. The collective data favor the emergence of cps loci of serotypes 6A, 6B, 6C, and 6D by complicated recombination.

  14. Core Oligosaccharide of Plesiomonas shigelloides PCM 2231 (Serotype O17 Lipopolysaccharide — Structural and Serological Analysis

    Directory of Open Access Journals (Sweden)

    Anna Maciejewska

    2013-02-01

    Full Text Available The herein presented complete structure of the core oligosaccharide of lipopolysaccharide (LPS P. shigelloides Polish Collection of Microorganisms (PCM 2231 (serotype O17 was investigated by 1H, 13C NMR spectroscopy, mass spectrometry, chemical analyses and serological methods. The core oligosaccharide is composed of an undecasaccharide, which represents the second core type identified for P. shigelloides serotype O17 LPS. This structure is similar to that of the core oligosaccharide of P. shigelloides strains 302-73 (serotype O1 and 7-63 (serotype O17 and differs from these only by one sugar residue. Serological screening of 55 strains of P. shigelloides with the use of serum against identified core oligosaccharide conjugated with bovine serum albumin (BSA indicated the presence of similar structures in the LPS core region of 28 O-serotypes. This observation suggests that the core oligosaccharide structure present in strain PCM 2231 could be the most common type among P. shigelloides lipopolysaccharides.

  15. Adrenal gland infection by serotype 5 adenovirus requires coagulation factors.

    Directory of Open Access Journals (Sweden)

    Lucile Tran

    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.

  16. Blocking enzyme-linked immunosorbent assay for detection of antibodies against Actinobacillus pleuropneumoniae serotype 6 in pig serum

    DEFF Research Database (Denmark)

    Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen

    2001-01-01

    A blocking enzyme-linked immunosorbent assay (ELISA) detecting antibodies against Actinobacillus pleuropneumoniae (Ap) serotype 6 was developed. The blocking ELISA was based on the inhibition of a polyclonal antibody raised against Ap serotype 6. Purified lipopolysaccharide from Ap serotype 6...

  17. Prevalence and Characteristics of Salmonella Serotypes Isolated from Fresh Produce Marketed in the United States.

    Science.gov (United States)

    Reddy, Shanker P; Wang, Hua; Adams, Jennifer K; Feng, Peter C H

    2016-01-01

    Salmonella continues to rank as one of the most costly foodborne pathogens, and more illnesses are now associated with the consumption of fresh produce. The U.S. Department of Agriculture Microbiological Data Program (MDP) sampled select commodities of fresh fruit and vegetables and tested them for Salmonella, pathogenic Escherichia coli, and Listeria. The Salmonella strains isolated were further characterized by serotype, antimicrobial resistance, and pulsed-field gel electrophoresis profile. This article summarizes the Salmonella data collected by the MDP between 2002 and 2012. The results show that the rates of Salmonella prevalence ranged from absent to 0.34% in cilantro. A total of 152 isolates consisting of over 50 different serotypes were isolated from the various produce types, and the top five were Salmonella enterica serotype Cubana, S. enterica subspecies arizonae (subsp. IIIa) and diarizonae (subsp. IIIb), and S. enterica serotypes Newport, Javiana, and Infantis. Among these, Salmonella serotypes Newport and Javiana are also listed among the top five Salmonella serotypes that caused most foodborne outbreaks. Other serotypes that are frequent causes of infection, such as S. enterica serotypes Typhimurium and Enteritidis, were also found in fresh produce but were not prevalent. About 25% of the MDP samples were imported produce, including 65% of green onions, 44% of tomatoes, 42% of hot peppers, and 41% of cantaloupes. However, imported produce did not show higher numbers of Salmonella-positive samples, and in some products, like cilantro, all of the Salmonella isolates were from domestic samples. About 6.5% of the Salmonella isolates were resistant to the antimicrobial compounds tested, but no single commodity or serotype was found to be the most common carrier of resistant strains or of resistance. The pulsed-field gel electrophoresis profiles of the produce isolates showed similarities with Salmonella isolates from meat samples and from outbreaks, but

  18. Detection and prediction of Streptococcus pneumoniae serotypes directly from nasopharyngeal swabs using PCR.

    Science.gov (United States)

    Lang, Amanda L S; McNeil, Shelly A; Hatchette, Todd F; Elsherif, May; Martin, Irene; LeBlanc, Jason J

    2015-08-01

    Monitoring Streptococcus pneumoniae serotype distribution is important to assess the impact and effectiveness of pneumococcal vaccine programs. With the challenges of Quellung serotyping, PCR-based serotype prediction is increasingly being used for large-scale epidemiological studies. This study used real-time (RT)-PCR targeting the genes encoding autolysin (lytA) and capsular biosynthesis gene A (cpsA) of S. pneumoniae in nucleic acids extracted directly from nasopharyngeal (NP) swabs submitted for viral studies. If the specimen was lytA or cpsA PCR-positive, then serotype prediction was performed on the same nucleic acid using eight conventional multiplex PCRs (cmPCRs) and seven real-time multiplex PCRs (rmPCRs). Of 1770 NP swabs, 132 (7.5  %) were lytA-positive and 122 (6.9  %) were positive for both targets (lytA and cpsA). Of the 122 lytA(+)cpsA(+) specimens, a serotype could be assigned in 52 (41.8  %) using cmPCR alone and the yield was increased to 70 (57.4  %) with the addition of rmPCR. Based on sensitivity, incremental yield and more efficient workflow, an algorithm was proposed where lytA and cpsA RT-PCR screening was followed by serotype deduction using rmPCR and a modified set of four instead of eight cmPCRs. This algorithm was validated for use on NP swabs, and the distribution of S. pneumoniae serotypes deduced from this approach showed good concordance with those obtained with cultured isolates serotyped by Quellung and PCR. Overall, molecular detection and serotyping of S. pneumoniae from NP swabs was found to be a valuable tool to assess S. pneumoniae colonization and monitor trends in serotype distribution.

  19. Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008–2014

    Science.gov (United States)

    Ceyhan, Mehmet; Ozsurekci, Yasemin; Gürler, Nezahat; Öksüz, Lütfiye; Aydemir, Sohret; Ozkan, Sengul; Yuksekkaya, Serife; Keser Emiroglu, Melike; Gültekin, Meral; Yaman, Akgün; Kiremitci, Abdurrahman; Yanık, Keramettin; Karli, Arzu; Ozcinar, Hatice; Aydin, Faruk; Bayramoglu, Gulcin; Zer, Yasemin; Gulay, Zeynep; Gayyurhan, Efgan Dogan; Gül, Mustafa; Özakın, Cüneyt; Güdücüoğlu, Hüseyin; Perçin, Duygu; Akpolat, Nezahat; Ozturk, Candan; Camcıoğlu, Yıldız; Karadağ Öncel, Eda; Çelik, Melda; Şanal, Laser; Uslu, Hakan

    2016-01-01

    Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008–2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008–2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008–2010 whereas was 37.6% in 2011–2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination. PMID:26325175

  20. Identification of Streptococcus pneumoniae serotype 11E, serovariant 11Av and mixed populations by high-resolution magic angle spinning nuclear magnetic resonance (HR-MAS NMR spectroscopy and flow cytometric serotyping assay (FCSA.

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    Romina Camilli

    Full Text Available BACKGROUND: Recent studies have identified Streptococcus pneumoniae serotype 11E and serovariant 11Av among isolates previously typed as 11A by classical serotyping methods. Serotype 11E and serovariant 11Av differ from serotype 11A by having totally or partially inactive wcjE, a gene in cps locus coding for an O-acetyl transferase. Serotype 11E is rare among carriage isolates but common among invasive isolates suggesting that it survives better during invasion. Aim of this work was to investigate the epidemiology of serotype 11A in a pneumococcal collection using a new serotyping approach based on High-Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HR-MAS NMR spectroscopy to distinguish serotypes 11A and 11E. METHODS: A collection of 48 (34 invasive and 14 carriage S. pneumoniae isolates from Italy, previously identified as serotype 11A by the Quellung reaction, were investigated by wcjE sequencing, HR-MAS NMR spectroscopy and the reference flow cytometric serotyping assay (FCSA based on monoclonal antibodies. RESULTS: HR-MAS NMR spectra from serotypes 11A and 11E showed different NMR peaks indicating that HR-MAS NMR could be used to distinguish these serotypes, although HR-MAS NMR could not distinguish serotype 11Av from serotype 11E unambiguously. Thirty-eight isolates were confirmed to be serotype 11A, 8 isolates with a mutated wcjE were serotype 11E, 1 isolate belonged to serovariant 11Av, and 1 isolate was a mixed population 11A/11Av. All 11E isolates were identified among invasive isolates. CONCLUSIONS: We proved that HR-MAS NMR can be of potential use for pneumococcal serotyping. The detection of serotype 11E among invasive isolates in our collection, supports previous epidemiological studies suggesting that mutations in wcjE can represent a mechanism promoting pneumococcal survival during invasion. The discovery of a spectrum of immunochemical diversity within established serotypes should stimulate efforts to develop new

  1. Serotype markers in a Streptococcus agalactiae strain collection from Zimbabwe

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    Mavenyengwa R

    2010-01-01

    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.

  2. The association of serotype and pulsed-field gel electrophoresis genotype in isolates of Streptococcus pneumoniae isolated in Israel

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    M. Bar-Meir

    2015-05-01

    Full Text Available The relationship between Streptococcus pneumoniae isolates causing invasive infections in children admitted to a single center in central Israel was examined by pulsed-field gel electrophoresis (PFGE and serotyping. Although there was a close correlation between serotype and PFGE clone, the genetic diversity varied by serotype, with some genotypes comprising multiple serotypes. Additionally, clones C and D were associated with higher penicillin minimum inhibitory concentrations. Serotyping alone may be insufficient for epidemiological mapping of pneumococcal isolates in the era of pneumococcal conjugate polysaccharide vaccines.

  3. The genetic organization of the capsular polysaccharide biosynthesis region of Actinobacillus pleuropneumoniae serotype 14.

    Science.gov (United States)

    Ito, Hiroya

    2015-05-01

    The genetic organization of the gene involved in the capsular polysaccharide (CPS) biosynthesis of Actinobacillus pleuropneumoniae serotype 14 has been determined. The DNA region for the CPS biosynthesis of serotype 14 (cps14) comprised 9 open reading frames, designated as cps14AB1B2B3CDEFG genes, encoding Cps14A to Cps14G protein, respectively. Cps14A was similar to CpsA of A. pleuropneumoniae serotypes 1, 4 and 12; the Cps14B1 and Cps14B2 were similar to CpsB of A. pleuropneumoniae serotypes 1, 4 and 12, suggesting that CPS structure of A. pleuropneumoniae serotype 14 would belong to Group I including A. pleuropneumoniae serotypes 1, 4, 12 and 15. Surprisingly, the overall nucleotide sequence, deduced amino acid sequence, and the genetic organization of the cps14 were nearly identical to those of Actinobacillus suis. This study will provide the molecular basic knowledge for development of diagnostics and vaccine of A. pleuropneumoniae serotype 14.

  4. Molecular epidemiology of serotype 19A Streptococcus pneumoniae isolated from children in Beijing, 1997-2006

    Institute of Scientific and Technical Information of China (English)

    XUE Lian; YAO Kai-hu; YU Sang-jie; LIU Zun-jie; QIAN Jing; SHEN Xu-zhuang; YANG Yong-hong

    2011-01-01

    Background Despite the prevalence of Streptococcus pneumoniae serotype 19A, the molecular characteristics of this serotype are yet to be fully elucidated. The aim of this study was therefore to determine the homology of the serotype 19A in China.Methods Pulsed-field gel electrophoresis and multilocus sequence typing were done to these forty-nine serotype 19A isolates to investigate the relationship between the strains prevalent in Beijing and other regions. Results From 1997 to 2006, the percentage of serotype 19A isolates increased. The susceptibility rate to penicillin and amoxicillin decreased and the resistance rate to cefuroxime increased. ST320 was the most prevalent ST, followed by ST3546. There were six new STs identified in our study. The serotype 19A strains were classified into six different pulsed-field gel electrophoresis (PFGE) patterns. ST320, which was associated with two different PFGE patterns (A and D), accounted for 32 isolates, and ST3546, which was associated with two PFGE patterns (B and E), accounted for eightConclusions From 2003 onwards, ST320 was the most common ST and the rate of resistance to cefuroxime increased significantly. Further long-term surveys of Streptococcus pneumoniae serotype 19A are required to monitor ST prevalence and antimicrobial resistance in this important human pathogen.

  5. Serotypes and antimicrobial resistance of meningeal isolates of Streptococcus pneumonia. Cuba, 2007-2012

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    Gilda Toraño-Peraza

    2014-12-01

    Full Text Available An observational study was conducted to know the serotypes and antimicrobial susceptibility of isolates of Streptococcus pneumoniae responsible for meningitis in Cuba, where there is no vaccine yet to prevent invasive pneumococcal disease. The study included the total number of isolates submitted to the "Pedro Kourí" Institute between 2007 and 2012 (N=237. Serotypes identification was performed using capsular swelling test and antimicrobial susceptibility was studied by determining the minimum inhibitory concentration using the broth microdilution method. Predominant serotypes were 6A, 6B, 14, 19F and 23F and other non-vaccinal 18 serogroups/serotypes were identified in 29.1% of the isolates. A tendency to an increased resistance to penicillin (44.3 % was observed; the most common resistance patterns were: penicillin-trimethoprim/sulfamethoxazole and penicillin-erythromycin (21.1% and 10.5%, respectively. The largest number of isolates resistant to penicillin was in serotypes 6B, 14, 19F and 23F and the possibility of resistant non-vaccine serotypes emergence should be considered. The results show that 70.4 % of the isolates studied corresponds to the serotypes included in 13-valent conjugated pneumococcal vaccine, but with 10-valent it would achieve a lower vaccination potential coverage (56.1%. This information must be considered when evaluating the decision to use in Cuba any commercially available vaccine or the proposal of another strategy of vaccination from autochthonous vaccine candidates.

  6. Serotype distribution of Streptococcus pneumoniae causing invasive disease in the Republic of Ireland.

    LENUS (Irish Health Repository)

    Vickers, I

    2011-05-01

    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.

  7. Homology and conservation of amino acids in E-protein sequences of dengue serotypes

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    Ramesh Venkatachalam

    2014-09-01

    Full Text Available Objective: To identify the homology and phylogenetic relationship among the four dengue virus (DENV serotypes, and conservation of amino acid in E-proteins and to find out the phylogenetic relationship among the strains of four DENV serotypes. Methods: Clustal W analysis for homology and phylogram, European molecular biology open software suite for pairwise alignment of amino acid sequences and BLAST-P analysis for various strains of four DENV serotypes were carried out. Results: Homology of E-protein sequences of four DENV serotypes indicated a close relationship of DENV-1 with DENV-3. DENV-2 showed close relationship with DENV-1 and -3 forming a single cluster whereas DENV-4 alone formed group with a single serotype. In the multiple sequence alignment, 19 amino acid conserved groups were observed. BLAST-P analysis showed more number of 100% similarity among DENV-1 and -3 strains whereas only few strains showed 100% similarity in DENV-4. However, 100% similarity was absent among the DENV-3 strains. Conclusions: From the present study, phylogenetically all the four DENV serotypes were related but DENV-1, -2 and -3 were very closely related whereas DENV-4 was somewhat distant from the other three serotypes.

  8. Prevalence and characteristics of Streptococcus pneumoniae "putative serotype 6E" isolates from Asian countries.

    Science.gov (United States)

    Baek, Jin Yang; Park, In Ho; So, Thomas Man-kit; Lalitha, M K; Shimono, Nobuyuki; Yasin, Rohani Md; Carlos, Celia C; Perera, Jennifer; Thamlikitkul, Visanu; Hsueh, Po-Ren; Van, Pham Hung; Shibl, Atef M; Song, Jae-Hoon; Ko, Kwan Soo

    2014-12-01

    The prevalence, antimicrobial susceptibility, and genotypes of Streptococcus pneumoniae “putative serotype 6E” isolates from Asian countries were investigated. A total of 244 S. pneumoniae serogroup 6 isolates obtained from 11 Asian countries were included in this study. Of the 244 serogroup 6 isolates, 101 (41.4%) were typed as "putative serotype 6E," followed by serotypes 6A, 6B, 6C, and 6D (27.0, 20.1, 5.7, and 5.7%, respectively). Multilocus sequence typing revealed that clonal complex (CC) 90, including ST90 and its variants, was the most prevalent clonal group of "putative serotype 6E" isolates (n = 63; 62.4%). CC146 and CC315 were also found frequently in some of the countries. Most of the "putative serotype 6E" isolates showed very high resistance rates against cefuroxime, erythromycin, azithromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole, probably due to their highly resistant to antimicrobials clone, CC90. Our results indicate that “putative serotype 6E” is prevalent in Asian countries. The clonal dissemination of "putative serotype 6E" isolates was also identified.

  9. Emergence and Distribution of Foot-and-Mouth Disease Virus Serotype A and O in Bangladesh.

    Science.gov (United States)

    Nandi, S P; Rahman, M Z; Momtaz, S; Sultana, M; Hossain, M A

    2015-06-01

    Foot-and-mouth disease (FMD) is endemic in Bangladesh and is predominantly due to FMDV serotype O. In 2012, FMD outbreaks were identified in five different districts of Bangladesh. Of 56 symptomatic cattle epithelial tissue samples, diagnostic PCR assay based on 5'-URT detected 38 FMDV infections. Viral genotyping targeting VP1-encoding region confirmed emergence of two distinct serotypes, A and O with an abundance of serotype A in Chittagong and Gazipur districts and serotype O in Pabna and Faridpur. Only single lineage of both A and O was retrieved from samples of five different regions. Sequencing and phylogenetic analysis of VP1 sequences revealed that serotype O sequences were closely related to the Ind 2001 sublineage of Middle East-South Asia (ME-SA) topotype that was previously circulating in Bangladesh, and serotype A sequences belonging to the genotype VII that was dominant in India during the last decade. The results suggest that extensive cross-border animal movement from neighbouring countries is the most likely source of FMDV serotypes in Bangladesh.

  10. Genetic and serological identification of three Vibrio parahaemolyticus strains as candidates for novel provisional O serotypes.

    Science.gov (United States)

    Guo, Xi; Liu, Bin; Chen, Min; Wang, Yuanyuan; Wang, Lu; Chen, Hongyou; Wang, Yao; Tu, Lihong; Zhang, Xi; Feng, Lu

    2017-03-20

    Vibrio parahaemolyticus is a Gram-negative, halophilic Vibrio that naturally inhabits marine and estuarine environments worldwide and has recently been recognized as one of the most important foodborne pathogens. To date, 13 O serotypes and 71 K serotypes of V. parahaemolyticus have been identified. However, untypeable V. parahaemolyticus strains are frequently found during routine detection, indicating that other forms of serotypes exist and suggesting the necessity for extension of the antigenic scheme. In this work, through the genetic analysis of the O serotype genetic determinants (OGDs) and the production of antisera and serological tests, we identified three novel O serotypes of V. parahaemolyticus. Further analyses showed that recombination and gene-set deletions/insertions within OGDs may play key roles in the generation of V. parahaemolyticus O serotype diversity. A PCR method was developed for the identification of these novel O serotypes, and specificity and sensitivity were evaluated. A double-blind test including 283 clinical isolates was performed, giving perfect correlation with the agglutination test results. Generally, our study expanded the O-antigenic scheme of V. parahaemolyticus from 13 to 16 and provided a tool with the potential for the detection and identification of V. parahaemolyticus strains (especially untypeable strains) isolated from both the clinic and the environment.

  11. Capsular Serotype and Antibiotic Resistance of Streptococcus pneumoniae Isolates in Two Chilean Cities

    Science.gov (United States)

    Inostroza, Jaime; Trucco, Olivia; Prado, Valeria; Vinet, Ana Maria; Retamal, Gloria; Ossa, Gonzalo; Facklam, Richard R.; Sorensen, Ricardo U.

    1998-01-01

    We compared the incidence of nasopharyngeal colonization by Streptococcus pneumoniae, the serotypes causing mucosal and invasive diseases, and the antibiotic resistance of these strains in patients admitted to three large hospitals and children attending day care centers in two Chilean cities (Santiago and Temuco). The populations in both cities were similar in ethnic background, socioeconomic status, family size, and access to medical care. Significant differences in nasopharyngeal colonization rates, in serotypes causing infections, and in antibiotic resistance were found between the two cities. In children 0 to 2 years of age, 42% were colonized with S. pneumoniae in Santiago compared to 14% in Temuco. A total of 41 serotypes were identified in both Chilean cities studied. Six serotypes were found only in Santiago; 14 serotypes were found only in Temuco. Antibiotic-resistant serotypes 6A, 6B, 14, 19F, and 23F were detected only in Santiago. We show that important differences in the incidence of nasopharyngeal carriage, infection, and S. pneumoniae serotypes can exist in similar populations in different areas of the same country. Our findings are relevant for prevention strategies, antibiotic usage, and vaccine design. PMID:9521139

  12. Serotype 1 and 8 Pneumococci Evade Sensing by Inflammasomes in Human Lung Tissue.

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    Diana Fatykhova

    Full Text Available Streptococcus pneumoniae is a major cause of pneumonia, sepsis and meningitis. The pore-forming toxin pneumolysin is a key virulence factor of S. pneumoniae, which can be sensed by the NLRP3 inflammasome. Among the over 90 serotypes, serotype 1 pneumococci (particularly MLST306 have emerged across the globe as a major cause of invasive disease. The cause for its particularity is, however, incompletely understood. We therefore examined pneumococcal infection in human cells and a human lung organ culture system mimicking infection of the lower respiratory tract. We demonstrate that different pneumococcal serotypes differentially activate inflammasome-dependent IL-1β production in human lung tissue and cells. Whereas serotype 2, 3, 6B, 9N pneumococci expressing fully haemolytic pneumolysins activate NLRP3 inflammasome-dependent responses, serotype 1 and 8 strains expressing non-haemolytic toxins are poor activators of IL-1β production. Accordingly, purified haemolytic pneumolysin but not serotype 1-associated non-haemolytic toxin activates strong IL-1β production in human lungs. Our data suggest that the evasion of inflammasome-dependent innate immune responses by serotype 1 pneumococci might contribute to their ability to cause invasive diseases in humans.

  13. Update on: Shigella new serogroups/serotypes and their antimicrobial resistance.

    Science.gov (United States)

    Muthuirulandi Sethuvel, D P; Devanga Ragupathi, N K; Anandan, S; Veeraraghavan, B

    2017-01-01

    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.

  14. Influence of serotype and virus strain on synergism between Marek's disease vaccine viruses.

    Science.gov (United States)

    Witter, R L

    1992-12-01

    The enhanced protective effect (synergism) when certain Marek's disease (MD) vaccine viruses are combined has been widely used in the development of improved vaccines, but the mechanism is poorly understood. To better characterize the basis for synergism among MD vaccine viruses, three vaccine viruses from each of the three MD viral serotypes were evaluated alone and in various combinations for protection against early challenge with very virulent MD viruses in four replicate trials. Synergism seemed to be influenced by viral serotype because significant enhancement occurred frequently between viruses of serotypes 2 and 3 (five of nine bivalent vaccines positive), but rarely between viruses of serotypes 1 and 3 (one of nine bivalent vaccines positive) and 1 and 2 (one of nine bivalent vaccines positive), and was not detectable between viruses of the same serotype (none of nine bivalent vaccines positive). With some exceptions, the degree of synergism tended to vary inversely with the mean protective efficacy of the most protective component virus. Little effect of virus dose, virus dose ratio or type and route of viral challenge was noted. The combination of strains 281MI/1 (serotype 2) and WTHV-1/1 (serotype 3), both poorly protective as monovalent vaccines, consistently demonstrated high levels of synergism (over 300%) in antibody-positive chickens challenged 5 days post-vaccination with Md5 virus. This protocol may be a useful model system for further studies on mechanisms of synergism. However, mixtures that optimize synergism are not necessarily as protective as commercial vaccines.

  15. El Niño-Southern Oscillation, local weather and occurrences of dengue virus serotypes

    Science.gov (United States)

    Huang, Xiaodong; Clements, Archie C. A.; Williams, Gail; Devine, Gregor; Tong, Shilu; Hu, Wenbiao

    2015-11-01

    Severe dengue fever is usually associated with secondary infection by a dengue virus (DENV) serotype (1 to 4) that is different to the serotype of the primary infection. Dengue outbreaks only occur following importations of DENV in Cairns, Australia. However, the majority of imported cases do not result in autochthonous transmission in Cairns. Although DENV transmission is strongly associated with the El Niño-Southern Oscillation (ENSO) climate cycle and local weather conditions, the frequency and potential risk factors of infections with the different DENV serotypes, including whether or not they differ, is unknown. This study used a classification tree model to identify the hierarchical interactions between Southern Oscillation Index (SOI), local weather factors, the presence of imported serotypes and the occurrence of the four autochthonous DENV serotypes from January 2000-December 2009 in Cairns. We found that the 12-week moving average of SOI and the 2-week moving average of maximum temperature were the most important factors influencing the variation in the weekly occurrence of the four DENV serotypes, the likelihoods of the occurrence of the four DENV serotypes may be unequal under the same environmental conditions, and occurrence may be influenced by changes in global and local environmental conditions in Cairns.

  16. Major tdh(+)Vibrio parahaemolyticus serotype changes temporally in the Bay of Bengal estuary of Bangladesh.

    Science.gov (United States)

    Akther, Farhana; Neogi, Sucharit Basu; Chowdhury, Wasimul B; Sadique, Abdus; Islam, Atiqul; Akhter, Marufa Zerin; Johura, Fatema-Tuz; Ohnishi, Makoto; Watanabe, Haruo; Boucher, Yan; Alam, Munirul

    2016-07-01

    Vibrio parahaemolyticus is responsible for seafood-related gastroenteritis worldwide. In Bangladesh, diarrhea is endemic and diarrheagenic V. parahaemolyticus serotypes occur naturally in the coastal and estuarine aquatic environment. V. parahaemolyticus strains, isolated from estuarine surface water of the Bay of Bengal villages of Bangladesh during 2006-2008, were tested for the presence of virulence and pandemic-marker genes, serodiversity, and phylogenetic relatedness. PCR analysis of V. parahaemolyticus (n=175) showed 53 (30.3%) strains to possess tdh, the major virulence gene encoding thermostable direct hemolysin. Serotyping results revealed the tdh(+)V. parahaemolyticus strains to belong to 10 different serotypes, of which the O8:K21 (30.2%) and O3:K6 (24.5%) were predominantly non-pandemic and pandemic serotypes, respectively; while O5:K30 and O9:KUT were new. The pandemic markers, orf8 and toxRS(variant), were present only in the pandemic serotype O3:K6 (n=13) and its serovariant O4:K68 (n=2). Temporal distribution of the tdh(+) serotypes revealed the O8:K21 to be predominant in 2006 and 2007, while O3:K6 was the predominant tdh(+) serotype in 2008. Pulsed-field gel electrophoresis (PFGE) of SfiI-digested genomic DNA revealed high genetic diversity among the V. parahaemolyticus strains, while dendrogram constructed with the PFGE patterns formed two major clusters separating the tdh(+) O3:K6 and its pandemic serovariants from the tdh(+) non-pandemic (O8:K21) strains, suggesting different lineages for them. The potential health risk related to the prevalent tdh(+) strains, including the observed temporal change of the predominant tdh(+) serotype, from O8:K21 to the pandemic serotype O3:K6 in estuarine surface waters serving as the major source of drinking water suggests the need for routine environmental monitoring to prevent V. parahaemolyticus infection in Bangladesh.

  17. Simultaneous Quantification and Differentiation of Streptococcus suis Serotypes 2 and 9 by Quantitative Real-time PCR, Evaluated in Tonsillar and Nasal Samples of Pigs

    NARCIS (Netherlands)

    Dekker, Niels; Daemen, Ineke; Verstappen, K.M.; Greeff, de A.; Smith, H.E.; Duim, Birgitta

    2016-01-01

    Abstract Invasive Streptococcus suis (S. suis) infections in pigs are often associated with serotypes 2 and 9. Mucosal sites of healthy pigs can be colonized with these serotypes, often multiple serotypes per pig. To unravel the contribution of these serotypes in pathogenesis and epidemiology, simul

  18. Experimental avian paramyxovirus serotype-3 infection in chickens and turkeys.

    Science.gov (United States)

    Kumar, Sachin; Militino Dias, Flavia; Nayak, Baibaswata; Collins, Peter L; Samal, Siba K

    2010-01-01

    Avian paramyxoviruses (APMV) are divided into nine serotypes. Newcastle disease virus (APMV-1) is the most extensively characterized, while relatively little information is available for the other APMV serotypes. In the present study, we examined the pathogenicity of two divergent strains of APMV-3, Netherlands and Wisconsin, in (i) 9-day-old embryonated chicken eggs, (ii) 1-day-old specific pathogen free (SPF) chicks and turkeys, and (iii) 2-week-old SPF chickens and turkeys. The mean death time in 9-day-old embryonated chicken eggs was 112 h for APMV-3 strain Netherlands and > 168 h for strain Wisconsin. The intracerebral pathogenicity index in 1-day-old chicks for strain Netherlands was 0.39 and for strain Wisconsin was zero. Thus, both strains are lentogenic. Both the strains replicated well in brain tissue when inoculated intracerebrally in 1-day-old SPF chicks, but without causing death. Mild respiratory disease signs were observed in 1-day-old chickens and turkeys when inoculated through oculonasal route with either strain. There were no overt signs of illness in 2-weeks-old chickens and turkeys by either strain, although all the birds seroconverted after infection. The viruses were isolated predominantly from brain, lungs, spleens, trachea, pancreas and kidney. Immunohistochemistry studies also showed the presence of large amount of viral antigens in both epithelial and sub-epithelial lining of respiratory and alimentary tracts. Our result suggests systemic spread of APMV-3 even though the viral fusion glycoprotein does not contain the canonical furin proteases cleavage site. Furthermore, there was little or no disease despite systemic viral spread and abundant viral replication in all the tissues tested.

  19. Serotypes of Salmonella in Broiler Carcasses Marketed at Ibague, Colombia.

    Directory of Open Access Journals (Sweden)

    JM Rodriguez

    2015-12-01

    Full Text Available ABSTRACT Salmonella enterica is a large group of Gram-negative bacteria responsible for a number of foodborne infections associated with the consumption of contaminated poultry products. The hygienic status of raw chicken meat marketed at Ibague, Tolima, Colombia, is currently unknown. To address this issue, a cross-sectional study was conducted to estimate the prevalence of Salmonella spp., in raw chicken marketed at different outlets in this city. Salmonella spp. was isolated by standard microbiological methods, followed by biochemical, serological, and molecular confirmation. Additionally, risk factors associated with the presence of the bacteria were identified. The prevalence of Salmonella in raw chicken was 17.41% (47/270, and 14 different serotypes were found, out of which S. Paratyphi B (36.17%, S. Hvittingfoss (19.15% and S. Muenster (10.64% were the most prevalent and represented 65.95% of all serotypes. Amplification of 284 bp of the invA gene was achieved by PCR in a number of randomly selected isolates. Raw chicken as the only type of meat sold at stores (odds ratio: 2,157, p<0.05, and stainless steel as a contact surface of chicken meat (odds ratio: 13,29, p<0.05, were found to be potential risk factors for the presence of Salmonella in chicken meat. This work serves as a reference about the current status of Salmonella in chicken meat marketed in Ibague, Tolima, Colombia, and indicates the need to establish appropriate control and contingency measures to minimize the presence of the bacteria in raw chicken to prevent its transmission to humans.

  20. Pathology of experimental infection by Pasteurella multocida serotype A: 1 in buffalo calves.

    Science.gov (United States)

    Praveena, P E; Periasamy, S; Kumar, A A; Singh, N

    2014-11-01

    Pasteurella multocida serotype A:3 has been mostly implicated in pneumonic pasteurellosis in ruminants. In contrast, our previous studies have reported that both serotypes A:1 and A:3 were responsible for respiratory diseases in cattle and buffaloes. However, the pathology and pathogenesis of P. multocida serotype A:1 (Pm A:1) infection have not been studied in ruminants. In the present study, 12- to 15-week-old buffalo calves (Bubalus bubalis) infected by Pm A:1 had fibrinous and suppurative bronchopneumonia with focal areas of coagulation necrosis typical of pneumonic pasteurellosis. For the first time, this study reports the lung pathology and pathogenecity of Pm A:1 infection in calves.

  1. Analysis of Loci Required for Determination of Serotype Antigenicity in Streptococcus mutans and Its Clinical Utilization

    OpenAIRE

    2003-01-01

    We recently identified the genes responsible for the serotype c-specific glucose side chain formation of rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans. These genes were located downstream from the rgpA through rgpF locus that is involved in the synthesis of RGP. In the present study, the corresponding chromosomal regions were isolated from serotype e and f strains and characterized. The rgpA through rgpF homologs were well conserved among the three serotypes. By contrast, the ...

  2. Comparison of a PCR serotyping assay, Check&Trace assay for Salmonella, and Luminex Salmonella serotyping assay for the characterization of Salmonella enterica identified from fresh and naturally contaminated cilantro.

    Science.gov (United States)

    Jean-Gilles Beaubrun, J; Ewing, L; Jarvis, K; Dudley, K; Grim, C; Gopinath, G; Flamer, M-L; Auguste, W; Jayaram, A; Elmore, J; Lamont, M; McGrath, T; Hanes, D E

    2014-09-01

    Salmonella enterica isolated from fresh cilantro samples collected through the USDA/AMS Microbiological Data Program (MDP) were used to compare a PCR serotyping assay against the Check&Trace assay and the Luminex (BioPlex) Salmonella serotyping assay. The study was conducted to evaluate the effectiveness of the three methods for serotyping Salmonella from both enrichment broth cultures and pure Salmonella cultures. In this investigation, Salmonella spp. serotyping was conducted using 24 h enrichment broth cultures and pure Salmonella cultures from cilantro samples, with the PCR serotyping assay. Conversely, the Check&Trace and Luminex for Salmonella assays required pure cultures for Salmonella serotyping. The cilantro samples contained S. enterica serovar Montevideo, Newport, Saintpaul, and Tennessee, identified by the PCR serotyping assay and Check&Trace for Salmonella, but the Luminex assay only identified two of the four serotypes of the cilantro samples. The anticipated impact from this study is that the PCR serotyping assay provides a time- and cost-effective means for screening, identifying and serotyping Salmonella using DNA extracted from 24 h enrichment cilantro samples.

  3. Immunoproteomic analysis of outer membrane proteins and extracellular proteins of Actinobacillus pleuropneumoniae JL03 serotype 3

    Directory of Open Access Journals (Sweden)

    Hu Yong

    2009-08-01

    Full Text Available Abstract Background Actinobacillus pleuropneumoniae is the causative agent of porcine contagious pleuropneumonia, a highly contagious respiratory infection in pigs, and all the 15 serotypes are able to cause disease. Current vaccines including subunit vaccines could not provide satisfactory protection against A. pleuropneumoniae. In this study, the immunoproteomic approach was applied to the analysis of extracellular and outer membrane proteins of A. pleuropneumoniae JL03 serotype 3 for the identification of novel immunogenic proteins for A. pleuropneumoniae. Results A total of 30 immunogenic proteins were identified from outer membrane and extracellular proteins of JL03 serotype 3, of which 6 were known antigens and 24 were novel immunogenic proteins for A. pleuropneumoniae. Conclusion These data provide information about novel immunogenic proteins for A. pleuropneumoniae serotype 3, and are expected to aid in development of novel vaccines against A. pleuropneumoniae.

  4. Isolation of bluetongue serotypes 1, 6 and 21 from insects in West Java

    Directory of Open Access Journals (Sweden)

    indrawati sendow

    2002-12-01

    Full Text Available Bluetongue virus is one of arbovirus diseases which is transmitted by insects, Culicoides spp. Insect collection wasconducted weekly from 1991 to 1993 and forthnightly from 1993 to 1997 in West Java using Pirbright-type miniature light trapin to phosphate buffered saline for identification and viral isolation. A total of 1155 pools of insects were inoculated intoembryonated chicken eggs before passaging in a mosquito cell line and three times blind passages in BHK-21 cells. Fourteenpools of insects produced cytopathic effect in BHK-21 cells. Four of the infected BHK-21 cells reacted in the antigen captureELISA test using a specific monoclonal antibody to bluetongue (BTV virus. Further identification into serotype in ReferenceLaboratory, indicated that BTV serotype 1 was isolated from C. fulvus, BTV serotype 6 was isolated from C. peregrinus andBTV serotype 21 from pools of C. shortii and C. orientalis.

  5. Salmonella enterica Serotype Choleraesuis Infection of the Knee and Femur in a Nonbacteremic Diabetic Patient

    Directory of Open Access Journals (Sweden)

    Alexander M. Sy

    2013-01-01

    Full Text Available Osteoarticular infections caused by Salmonella are rare. The rates of osteomyelitis and septic arthritis due to Salmonella are estimated to be less than 1% and 0.1%-0.2%, respectively (Kato et al., 2012. Salmonella enterica serotype Choleraesuis is a nontyphoidal Salmonella, highly pathogenic in humans, usually causing septicemic disease with little or no intestinal involvement. Serotype Choleraesuis accounts for a small percentage of published studies of Salmonella infections in the United States. It is not commonly reported in joint fluid and bones in contrast to serotype Enteritidis and Typhi, where a considerable number of cases have been published. Chen et al. in Taiwan found that 21% of bacteremic patients with this infection subsequently develop focal infections such as septic arthritis, pneumonia, peritonitis, and cutaneous abscess (Chen et al., 1999, Chiu et al., 2004. In contrast, our patient presented with localized osteoarticular infection with Salmonella enterica serotype Cholerasuis, but without evidence of bacteremia.

  6. Comparative investigations of Klebsiella species of clinical origin: plasmid patterns, biochemical reactions, antibiotic resistances and serotypes.

    Science.gov (United States)

    Podschun, R; Heineken, P; Ullmann, U; Sonntag, H G

    1986-09-01

    A total of 124 K. pneumoniae and 52 K. oxytoca isolates obtained from clinical specimens was investigated for plasmid patterns, biochemical reactions, antibiotic resistances and serotypes regarding to the distribution and relationships of these characters. A great diversity of plasmid patterns, bio/serotypes and resistance patterns was revealed. About 90% of strains contained plasmid DNA and up to seven plasmid bands per isolate could be shown. For K. pneumoniae, serotype 7 and for K. oxytoca, type 55 were most common. In general, little difference between both species was found and characters were similarly distributed. With respect to the site of isolation, serotype 7 was predominating in K. pneumoniae strains from the respiratory tract. Highly multiple-resistant organism were found in the largest number in specimens from the urogenital tract, in the lowest in specimens from wounds. Extensive statistical analyses did not detect any relationship among the characters investigated.

  7. Prevalence and molecular characterisation of Streptococcus pneumoniae serotype 6C in Queensland, Australia.

    Science.gov (United States)

    Staples, Megan; Jennison, Amy V; Ariotti, Lawrence; Hicks, Vicki; Graham, Rikki M A; Smith, Helen V

    2014-03-01

    Streptococcus pneumoniae serotype 6C was first identified in 2007, although retrospective studies have since identified serotype 6C among stored isolates dating back to 1962. We investigated the incidence and genetic diversity of serotype 6C strains isolated from Queensland patients between 2001 and 2011. Isolates were identified by Quellung reaction and antimicrobial susceptibility testing was performed. The incidence of serotype 6C among serogroup 6 Queensland invasive pneumococcal disease increased from 6.8% (2001-2004) to 39% (2005-2010) of serogroup 6 isolates (P = 0). Genetic diversity of Queensland 6C isolates was high, with molecular analysis identifying 19 sequence types by multi-locus sequence typing, and 35 types by multi-locus variable-number tandem repeat analysis.

  8. Genome Sequence of Aggregatibacter actinomycetemcomitans Serotype c Strain D11S-1 ▿

    OpenAIRE

    Chen, Casey; Kittichotirat, Weerayuth; Si, Yan; Bumgarner, Roger

    2009-01-01

    Aggregatibacter actinomycetemcomitans is a major etiological agent of periodontitis. Here we report the complete genome sequence of serotype c strain D11S-1, which was recovered from the subgingival plaque of a patient diagnosed with generalized aggressive periodontitis.

  9. Serotype-specific changes in invasive pneumococcal disease after pneumococcal conjugate vaccine introduction

    DEFF Research Database (Denmark)

    Feikin, Daniel R; Kagucia, Eunice W; Loo, Jennifer D;

    2013-01-01

    BACKGROUND: Vaccine-serotype (VT) invasive pneumococcal disease (IPD) rates declined substantially following introduction of 7-valent pneumococcal conjugate vaccine (PCV7) into national immunization programs. Increases in non-vaccine-serotype (NVT) IPD rates occurred in some sites, presumably...... representing serotype replacement. We used a standardized approach to describe serotype-specific IPD changes among multiple sites after PCV7 introduction. METHODS AND FINDINGS: Of 32 IPD surveillance datasets received, we identified 21 eligible databases with rate data ≥ 2 years before and ≥ 1 year after PCV7...... introduction. Expected annual rates of IPD absent PCV7 introduction were estimated by extrapolation using either Poisson regression modeling of pre-PCV7 rates or averaging pre-PCV7 rates. To estimate whether changes in rates had occurred following PCV7 introduction, we calculated site specific rate ratios...

  10. First environmental isolation of Cryptococcus gattii serotype B, from Cúcuta, Colombia

    National Research Council Canada - National Science Library

    Firacative, Carolina; Torres, Germán; Rodríguez, María Claudia; Escandón, Patricia

    2011-01-01

    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...

  11. Serotypes and Antimicrobial Resistance of Human Nontyphoidal Isolates of Salmonella enterica from Crete, Greece.

    Science.gov (United States)

    Maraki, Sofia; Papadakis, Ioannis S

    2014-01-01

    We report on the serotype distribution and the antimicrobial resistance patterns to 20 different antimicrobials of 150 Salmonella enterica strains isolated from stools of diarrhoeal patients on the island of Crete over the period January 2011-December 2012. Among the S. enterica serotypes recovered, Enteritidis was the most prevalent (37.3%), followed by Typhimurium (28.7%) and Newport (8.7%). No resistance was detected to extended-spectrum cephalosporins and carbapenems. Rates of resistance to ampicillin, amoxicillin/clavulanic acid, chloramphenicol, tetracycline, and cotrimoxazole were 9.3%, 4%, 2%, 15.3%, and 8.7%, respectively. Resistance to ≥4 antibiotics was primarily observed for serotypes Typhimurium and Hadar. Enteritidis remains the predominant serotype in Crete. Although low resistance to most antimicrobials was detected, continued surveillance of susceptibility is needed due to the risk of resistance.

  12. Form, symmetry and packing of biomacromolecules. II. Serotypes of human rhinovirus

    Science.gov (United States)

    Janner, A.

    2010-05-01

    The differentiation of the human rhinovirus into serotypes, all having very similar structures and the same architecture, is shown to be related to the packing of the viruses in the crystal and to its space-group symmetry.

  13. Serotypes and Antimicrobial Resistance of Human Nontyphoidal Isolates of Salmonella enterica from Crete, Greece

    Directory of Open Access Journals (Sweden)

    Sofia Maraki

    2014-01-01

    Full Text Available We report on the serotype distribution and the antimicrobial resistance patterns to 20 different antimicrobials of 150 Salmonella enterica strains isolated from stools of diarrhoeal patients on the island of Crete over the period January 2011-December 2012. Among the S. enterica serotypes recovered, Enteritidis was the most prevalent (37.3%, followed by Typhimurium (28.7% and Newport (8.7%. No resistance was detected to extended-spectrum cephalosporins and carbapenems. Rates of resistance to ampicillin, amoxicillin/clavulanic acid, chloramphenicol, tetracycline, and cotrimoxazole were 9.3%, 4%, 2%, 15.3%, and 8.7%, respectively. Resistance to ≥4 antibiotics was primarily observed for serotypes Typhimurium and Hadar. Enteritidis remains the predominant serotype in Crete. Although low resistance to most antimicrobials was detected, continued surveillance of susceptibility is needed due to the risk of resistance.

  14. Quantitative comparison of intestinal invasion of zoonotic serotypes of Salmonella enterica in poultry

    DEFF Research Database (Denmark)

    Aabo, Søren; Christensen, J.P.; Chadfield, M.S.

    2002-01-01

    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......The aim of the present study was to compare the invasion of selected zoonotic Salmonella serotypes of poultry in an in vivo chicken intestinal loop model and also in vitro in epithelial cell cultures. Invasion was measured relative to a reference strain, Salmonella Typhimurium 4/74 invH201::Tnpho......, S. Enteritidis PT6, S. Enteritidis PT8, and Salmonella Berta. The serotypes Salmonella Hadar, Salmonella Virchow, S. 4,12: b:-, S. Typhimurium DT41, and Salmonella Infantis, most of which are considered horizontally transmitted, did not show significantly different intracellular counts from...

  15. Pediatric invasive pneumococcal disease caused by vaccine serotypes following the introduction of conjugate vaccination in Denmark

    DEFF Research Database (Denmark)

    Harboe, Zitta B; Valentiner-Branth, Palle; Ingels, Helene

    2013-01-01

    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...

  16. Changing pattern of dengue virus serotypes circulating during 2008-2012 and reappearance of dengue serotype 3 may cause outbreak in Kolkata, India.

    Science.gov (United States)

    Saha, Kallol; Ghosh, Monika; Firdaus, Rushna; Biswas, Aritra; Seth, Bikash; Bhattacharya, Debojyoti; Mukherjee, Kheya; Sadhukhan, Provash Chandra

    2016-10-01

    Dengue virus infection is a major cause of morbidity within the endemic tropical and subtropical regions of the world. Dengue virus has four distinct serotypes with specific clinical manifestations. In this study, we observed the changing pattern of dengue serotypes, age-wise dengue infection and useful sero-detection methods needed in a dengue endemic region. We identified dengue serotypes during a period of 5 years among patients with dengue symptoms visiting one of the largest tertiary care infectious disease hospitals of eastern India in Kolkata. A total of 433 dengue RNA positive samples were isolated from 712 acute dengue suspected cases. Age wise distribution highlighted the susceptible age group being >21 years (24.02%) followed by 11-15 years (21.71%) and 5-10 years (21.02%) of the total infected population. Higher numbers of infected cases were found within females as they are involved in more indoor works. The period of study experienced two dengue outbreaks one in 2008 and another in 2012. For early dengue detection, NS1 was found to be more confirmatory than IgM ELISA regarding sensitivity and specificity. DENV-1, 2, and 4 serotypes were the common circulating strains from 2008 until 2010, after which DENV-3 serotype infections rise and led to a massive dengue outbreak in Kolkata with increased numbers of DHF and DSS cases in 2012. The finding within our study emphasizes the public health importance of such prospective surveillance programs with respect to the changing dengue viral etiology and serotypes. J. Med. Virol. 88:1697-1702, 2016. © 2016 Wiley Periodicals, Inc.

  17. Streptococcus suis bacterin and subunit vaccine immunogenicities and protective efficacies against serotypes 2 and 9.

    Science.gov (United States)

    Baums, Christoph Georg; Kock, Christoph; Beineke, Andreas; Bennecke, Katharina; Goethe, Ralph; Schröder, Charlotte; Waldmann, Karl-Heinz; Valentin-Weigand, Peter

    2009-02-01

    Streptococcus suis causes numerous diseases in pigs, most importantly, meningitis, arthritis, septicemia, and bronchopneumonia. One of the major problems in modern swine production is the lack of a vaccine protecting against more than one S. suis serotype. The objective of this study was to determine the protective efficacy of a serotype 2 murein-associated protein (MAP) fraction subunit vaccine in comparison to that of a bacterin against experimental challenge with serotype 2 (containing muramidase-released protein [MRP], extracellular factor, and suilysin [SLY]) and serotype 9 (containing MRP variant MRP* and SLY) strains. MAP was shown to include different surface-associated proteins, such as the MRP and surface antigen one (SAO) expressed by both pathotypes used for challenge. The results of this study demonstrated that the serotype 2 bacterin induced protective immunity against homologous challenge. In contrast, the protective efficacy of the MAP subunit vaccine was low, though MAP immunization resulted in high serum immunoglobulin G2 titers against MRP and SAO. Importantly, immunization with bacterin but not with MAP induced opsonizing antibody titers against the serotype 2 strain, and these antibody titers were found to correlate with protection. However, after absorption with a nonencapsulated isogenic mutant, the sera from bacterin-immunized piglets failed to facilitate neutrophil killing, indicating that antibodies directed against capsule may not have been essential for opsonophagocytosis. Furthermore, induction of opsonizing antibodies against serotype 9 was not detectable in the group receiving bacterin or in the group receiving the MAP vaccine. In agreement, protection against the heterologous serotype 9 strain was low in both groups. Thus, identification of an antigen protecting against these two important S. suis pathotypes remains an important goal of future studies.

  18. Localized adherence and attaching-effacing properties of nonenteropathogenic serotypes of Escherichia coli.

    OpenAIRE

    Albert, M J; Alam, K; Ansaruzzaman, M.; Montanaro, J; Islam, M.; Faruque, S. M.; Haider, K; Bettelheim, K; Tzipori, S.

    1991-01-01

    Traditional enteropathogenic Escherichia coli serotypes demonstrate a plasmid-mediated localized adherence in cultured HeLa or HEp-2 cells and induce an attaching-effacing intestinal lesion, both of which are considered pathognomonic and causes of diarrhea. This study describes three E. coli strains from infantile diarrhea which share these properties but belong to serotypes (O2:H2, O2:H25 and O15:H2) not considered enteropathogenic.

  19. Correlation of Serotype-Specific Dengue Virus Infection with Clinical Manifestations

    Science.gov (United States)

    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

    2012-01-01

    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

  20. Biofilms of Candida albicans serotypes A and B differ in their sensitivity to photodynamic therapy.

    Science.gov (United States)

    Rossoni, Rodnei Dennis; Barbosa, Júnia Oliveira; de Oliveira, Felipe Eduardo; de Oliveira, Luciane Dias; Jorge, Antonio Olavo Cardoso; Junqueira, Juliana Campos

    2014-09-01

    Candida albicans is classified into different serotypes according to cell wall mannan composition and cell surface hydrophobicity. Since the effectiveness of photodynamic therapy (PDT) depends on the cell wall structure of microorganisms, the objective of this study was to compare the sensitivity of in vitro biofilms of C. albicans serotypes A and B to antimicrobial PDT. Reference strains of C. albicans serotype A (ATCC 36801) and serotype B (ATCC 36802) were used for the assays. A gallium-aluminum-arsenide laser (660 nm) was used as the light source and methylene blue (300 μM) as the photosensitizer. After biofilm formation on the bottom of a 96-well microplate for 48 h, each Candida strain was submitted to assays: PDT consisting of laser and photosensitizer application (L + P+), laser application alone (L + P-), photosensitizer application alone (L-P+), and application of saline as control (L-P-). After treatment, biofilm cells were scraped off and transferred to tubes containing PBS. The content of the tubes was homogenized, diluted, and seeded onto Sabouraud agar plates to determine the number of colony-forming units (CFU/mL). The results were compared by analysis of variance and Tukey test (p < 0.05). The two strains studied were sensitive to PDT (L + P+), with a log reduction of 0.49 for serotype A and of 2.34 for serotype B. Laser application alone only reduced serotype B cells (0.53 log), and the use of the photosensitizer alone had no effect on the strains tested. It can be concluded that in vitro biofilms of C. albicans serotype B were more sensitive to PDT.

  1. Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

    OpenAIRE

    Ángel Manuel Martínez-Robles; Juan Pablo Loyola-Rodríguez; Norma Verónica Zavala-Alonso; Rita Elizabeth Martinez-Martinez; Facundo Ruiz; René Homero Lara-Castro; Alejandro Donohué-Cornejo; Simón Yobanny Reyes-López; León Francisco Espinosa-Cristóbal

    2016-01-01

    (1) Background: Streptococcus mutans (S. mutans) is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k). Silver nanoparticles (SNP) have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characteri...

  2. Passive immunization of pigs against experimental infection with Streptococcus suis serotype 2

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Tegtmeier, Conny

    2001-01-01

    The safety and protective efficacy of a horse antiserum raised against inactivated whole cell preparations of Streptococcus suis serotype 2 was investigated in pigs by experimental challenge. The antiserum was evaluated in two similar experiments each comprising 12 4-week-old pigs treated with 6 ...... indicate that passive immunization of pigs may be a way to reduce or control S. suis serotype 2 infections in pigs....

  3. Evidence that pneumococcal serotype replacement in Massachusetts following conjugate vaccination is now complete

    Science.gov (United States)

    Hanage, William P.; Finkelstein, Jonathan A.; Huang, Susan S.; Pelton, Stephen I.; Stevenson, Abbie E.; Kleinman, Ken; Hinrichsen, Virginia L.; Fraser, Christophe

    2010-01-01

    Invasive pneumococcal disease (IPD) has been reduced in the US following conjugate vaccination (PCV7) targeting seven pneumococcal serotypes in 2000. However, increases in IPD due to other serotypes have been observed, in particular 19A. How much this “serotype replacement” will erode the benefits of vaccination and over what timescale is unknown. We used a population genetic approach to test first whether the selective impact of vaccination could be detected in a longitudinal carriage sample, and secondly how long it persisted for following introduction of vaccine in 2000. To detect the selective impact of the vaccine we compared the serotype diversity of samples from pneumococcal carriage in Massachusetts children collected in 2001, 2004 and 2007 with others collected in the pre-vaccine era in Massachusetts, the UK and Finland. The 2004 sample was significantly (p >0.0001) more diverse than pre-vaccine samples, indicating the selective pressure of vaccination. The 2007 sample showed no significant difference in diversity from the pre-vaccine period, and exhibited similar population structure, but with different serotypes. In 2007 the carriage frequency of 19A was similar to that of the most common serotype in pre-vaccine samples. We suggest that serotype replacement involving 19A may be complete in Massachusetts due to similarities in population structure to pre-vaccine samples. These results suggest that the replacement phenomenon occurs rapidly with high vaccine coverage, and may allay concerns about future increases in disease due to 19A. For other serotypes, the future course of replacement disease remains to be determined. PMID:21031138

  4. Phylogenetic and Molecular Clock Analysis of Dengue Serotype 1 and 3 from New Delhi, India.

    Science.gov (United States)

    Afreen, Nazia; Naqvi, Irshad H; Broor, Shobha; Ahmed, Anwar; Parveen, Shama

    2015-01-01

    Dengue fever is the most prevalent arboviral disease in the tropical and sub-tropical regions of the world. The present report describes molecular detection and serotyping of dengue viruses in acute phase blood samples collected from New Delhi, India. Phylogenetic and molecular clock analysis of dengue virus serotype 1 and 3 strains were also investigated. Dengue virus infection was detected in 68.87% out of 604 samples tested by RT-PCR between 2011 & 2014. Dengue serotype 1 was detected in 25.48% samples, dengue serotype 2 in 79.56% samples and dengue serotype 3 in 11.29% samples. Dengue serotype 4 was not detected. Co-infection by more than one dengue serotype was detected in 18.26% samples. Envelope gene of 29 DENV-1 and 14 DENV-3 strains were sequenced in the study. All the DENV-1 strains grouped with the American African genotype. All DENV-3 strains were found to belong to Genotype III. Nucleotide substitution rates of dengue 1 and 3 viruses were determined in the study. Time to the most recent common ancestor (TMRCA) of dengue 1 viruses was determined to be 132 years. TMRCA of DENV-3 viruses was estimated to be 149 years. Bayesian skyline plots were constructed for Indian DENV-1 and 3 strains which showed a decrease in population size since 2005 in case of DENV- 1 strains while no change was observed in recent years in case of DENV-3 strains. The study also revealed a change in the dominating serotype in Delhi, India in recent years. The study will be helpful in formulating control strategies for the outbreaks. In addition, it will also assist in tracking the movement and evolution of this emerging virus.

  5. Characterization of serological cross-reactivity between polysaccharide antigens of Streptococcus mutans serotypes c and d.

    OpenAIRE

    Grossi, S.; Prakobphol, A; Linzer, R; Campbell, L K; Knox, K W

    1983-01-01

    Immunological assays with antisera prepared against purified Streptococcus mutans serotype c polysaccharide demonstrated that a cross-reacting determinant on c polysaccharide reacted with the wall-associated rhamnose-glucose polysaccharide from S. mutans serotype d. Studies with 60 antisera prepared against chemostat cultures of S. mutans Ingbritt (c) demonstrated that the rhamnose-glucose polysaccharide cross-reactive determinant was consistently expressed on c antigen under a variety of gro...

  6. Serotype Distribution and Antimicrobial Susceptibilities of Invasive Streptococcus pneumoniae Isolates from Adults in Korea from 1997 to 2012.

    Science.gov (United States)

    Kim, Chung Jong; Song, Jin-Su; Choi, Su-Jin; Song, Kyoung Ho; Choe, Pyeong Gyun; Park, Wan Beom; Bang, Ji Hwan; Kim, Eu Suk; Park, Sang Won; Kim, Hong Bin; Kim, Nam-Joong; Kim, Eui-Chong; Oh, Myoung-don

    2016-05-01

    In Republic of Korea, a 7-valent pneumococcal conjugated vaccine (PCV7) was licensed for use in infants in 2003, and 13-valent PCV (PCV13) replaced it since 2010. We investigated trends in serotype distribution and antibiotic susceptibility of pneumococcal isolates from adult patients with invasive pneumococcal diseases (IPD). Invasive pneumococcal isolates from adult patients of ≥ 16 years of age were collected from 1997 to 2012. Serotypes of the isolates were determined by the Quellung reaction. Distribution of serotypes was analyzed according to the vaccine types. Antibiotic susceptibility was tested by using E-test strips. A total of 272 invasive pneumococcal isolates were included. The most common serotypes were serotype 19F (8.5%, 23/272), and serotype 3 (8.1%, 22/272), and 24.6% (67/272) of the isolates were of non-vaccine serotypes. Of the 272 isolates, 2.6% (7/272) were penicillin MICs of ≥ 4 µg/mL. The proportion of the PCV13 serotypes decreased from 63.3% (50/79) in 1997-2003 to 48.6% (17/35) in 2011-2012, whereas that of non-vaccine serotypes was 26.6% (21/79) and 25.7% (9/35), respectively, for the same periods. The proportion of the PCV13 serotypes showed a decreasing trend among adult patients with IPD over the study period.

  7. Serotype-specific epitope(s) present on the VP8 subunit of rotavirus VP4 protein.

    Science.gov (United States)

    Larralde, G; Li, B G; Kapikian, A Z; Gorziglia, M

    1991-01-01

    cDNA clones representing the VP8 and VP5 subunits of VP4 of symptomatic human rotavirus strain KU (VP7 serotype 1 and VP4 serotype 1A) or DS-1 (VP7 serotype 2 and VP4 serotype 1B) or asymptomatic human rotavirus strain 1076 (VP7 serotype 2 and VP4 serotype 2) were constructed and inserted into the pGEMEX-1 plasmid and expressed in Escherichia coli. Immunization of guinea pigs with the VP8 or VP5 protein of each strain induced antibodies that neutralized the rotavirus from which the VP4 subunits were derived. In a previous study (M. Gorziglia, G. Larralde, A.Z. Kapikian, and R. M. Chanock, Proc. Natl. Acad. Sci. USA 87:7155-7159, 1990), three distinct serotypes and one subtype of VP4 outer capsid protein were identified among 17 human rotavirus strains that had previously been assigned to five distinct VP7 serotypes. The results obtained by cross-immunoprecipitation and by neutralization assay with antisera to the VP8- and VP5-expressed proteins suggest that the VP8 subunit of VP4 contains the major antigenic site(s) responsible for serotype-specific neutralization of rotavirus via VP4, whereas the VP5 subunit of VP4 is responsible for much of the cross-reactivity observed among strains that belong to different VP4 serotypes. Images PMID:1709699

  8. A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri.

    Directory of Open Access Journals (Sweden)

    Qiangzheng Sun

    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.

  9. A novel plasmid-encoded serotype conversion mechanism through addition of phosphoethanolamine to the O-antigen of Shigella flexneri.

    Science.gov (United States)

    Sun, Qiangzheng; Knirel, Yuriy A; Lan, Ruiting; Wang, Jianping; Senchenkova, Sof'ya N; Jin, Dong; Shashkov, Alexander S; Xia, Shengli; Perepelov, Andrei V; Chen, Qiang; Wang, Yan; Wang, Haiyin; Xu, Jianguo

    2012-01-01

    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.

  10. Antimicrobial Properties of Biofunctionalized Silver Nanoparticles on Clinical Isolates of Streptococcus mutans and Its Serotypes

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    Ángel Manuel Martínez-Robles

    2016-07-01

    Full Text Available (1 Background: Streptococcus mutans (S. mutans is the principal pathogen involved in the formation of dental caries. Other systemic diseases have also been associated with specific S. mutans serotypes (c, e, f, and k. Silver nanoparticles (SNP have been demonstrated to have good antibacterial effects against S. mutans; therefore, limited studies have evaluated the antimicrobial activity of biofunctionalized SNP on S. mutans serotypes. The purpose of this work was to prepare and characterize coated SNP using two different organic components and to evaluate the antimicrobial activity of SNP in clinical isolates of S. mutans strains and serotypes; (2 Methods: SNP with bovine serum albumin (BSA or chitosan (CS coatings were prepared and the physical, chemical and microbiological properties of SNP were evaluated; (3 Results: Both types of coated SNP showed antimicrobial activity against S. mutans bacteria and serotypes. Better inhibition was associated with smaller particles and BSA coatings; however, no significant differences were found between the different serotypes, indicating a similar sensitivity to the coated SNP; (4 Conclusion: This study concludes that BSA and CS coated SNP had good antimicrobial activity against S. mutans strains and the four serotypes, and this study suggest the widespread use of SNP as an antimicrobial agent for the inhibition of S. mutans bacteria.

  11. Longitudinal survey of the distribution of various serotypes of Streptococcus mutans in infants.

    Science.gov (United States)

    Masuda, N; Tsutsumi, N; Sobue, S; Hamada, S

    1979-10-01

    The establishment of various serotypes of Streptococcus mutans was studied serologically in plaque samples collected from label surfaces of upper primary incisors of 22 infants (starting age, 5 to 13 months) over a period fo 30 months. Clinical examinations were also performed. No clear-cut association between the initiation of dental caries and previous detection of S. mutans was noted. However, all 12 of the infants with caries had S. mutans isolated at some time during the course of this study. The most common serotype isolated at the initial establishment of S. mutans on the tooth surfaces was serotype c, whereas types d, e, and g became established in a few cases. During the test period, changes in the distribution of serotypes of S. mutans were observed in some cases. The initiation of carious lesions could be found in a few cases even when S. mutans comprised about 1% or less of the total streptococcal count of the specimen from the tooth surfaces. Serotype d/g strains tended to develop carious lesions on smooth surfaces, although serotype c was isolated from almost all individuals who developed caries.

  12. Sentinel Surveillance Detects Low Circulation of Vibrio cholerae Serotype Inaba in Haiti, 2011-2012.

    Science.gov (United States)

    Llanes, Rafael; Lazo, Alcides; Somarriba, Lorenzo; Mas, Pedro

    2015-07-01

    Over 700,000 cases of cholera were reported in Haiti between October 2010 and February 2015. In November 2011, the Cuban Medical Team serving in Haiti established a laboratory-supported sentinel surveillance system for cholera in 10 public hospitals (one in each of Haiti's 10 departments), to estimate the proportion of hospitalized patients with cholera and detect emergence of new Vibrio cholerae serotypes. Each month, the first ten stool samples collected from patients admitted with acute watery diarrhea were studied in all hospitals involved. Surveillance system findings from November 1, 2011, to October 30, 2012 showed that acute watery diarrhea was caused by V. cholerae serogroup O1 in 45.9% (210/458) of patients: Serotype Ogawa was found in 98.6% of this isolates (207/210) and serotype Inaba in 1.4% (3/210), indicating low circulation level of the latter in Haiti. Continuing laboratory sentinel surveillance of V. cholerae is needed to monitor the spread of the disease and prevent and contain outbreaks, particularly of new serotypes. It is important to ensure that these findings are systematically integrated with data available to MSPP from other surveillance sources. KEYWORDS Vibrio cholerae, serotype Inaba, serotype Ogawa, epidemiological surveillance, medical cooperation, Haiti, Cuba.

  13. Chlamydia trachomatis serotype A infections in the Amazon region of Brazil: prevalence, entry and dissemination

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    Marluísa de Oliveira Guimarães Ishak

    2015-04-01

    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.

  14. Serotype specific polymerase chain reaction identifies a higher prevalence of streptococcus mutans serotype k and e in a random group of children with dental caries from the Southern region of India

    OpenAIRE

    Arun Prasad Rao; Ravi David Austin

    2014-01-01

    Background: The development of dental caries has been associated with the oral prevalence of Streptococcus mutans. Four serotypes of S. mutans have been reported, namely serotype c, e, f, and k that are classified based on the composition and linkages of cell wall polysaccharides, response to physiological reactions, sero-specificity and 16s rRNA homology. Although the oral prevalence of S. mutans serotype c in Indian subjects with or without caries is known, the prevalence of the other three...

  15. Simultaneous Quantification and Differentiation of Streptococcus suis Serotypes 2 and 9 by Quantitative Real-Time PCR, Evaluated in Tonsillar and Nasal Samples of Pigs : Gelijktijdige kwantificering en differentiatie van Streptococcus suis serotypes 2 en 9 met kwantitatieve Real-Time PCR, onderzocht in tonsil en neus monsters van varkens

    NARCIS (Netherlands)

    Dekker, Niels; Daemen, Ineke; Verstappen, Koen; de Greeff, Astrid; Smith, Hilde; Duim, Birgitta

    2016-01-01

    Invasive Streptococcus suis (S. suis) infections in pigs are often associated with serotypes 2 and 9. Mucosal sites of healthy pigs can be colonized with these serotypes, often multiple serotypes per pig. To unravel the contribution of these serotypes in pathogenesis and epidemiology, simultaneous q

  16. Identification of a natural human serotype 3 parainfluenza virus

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    Wang Xiao-Jing

    2011-02-01

    Full Text Available Abstract Parainfluenza virus is an important pathogen threatening the health of animals and human, which brings human many kinds of disease, especially lower respiratory tract infection involving infants and young children. In order to control the virus, it is necessary to fully understand the molecular basis resulting in the genetic diversity of the virus. Homologous recombination is one of mechanisms for the rapid change of genetic diversity. However, as a negative-strand virus, it is unknown whether the recombination can naturally take place in human PIV. In this study, we isolated and identified a mosaic serotype 3 human PIV (HPIV3 from in China, and also provided several putative PIV mosaics from previous reports to reveal that the recombination can naturally occur in the virus. In addition, two swine PIV3 isolates transferred from cattle to pigs were found to have mosaic genomes. These results suggest that homologous recombination can promote the genetic diversity and potentially bring some novel biologic characteristics of HPIV.

  17. Epizootic hemorrhagic disease virus serotype 6 experimentation on adult cattle.

    Science.gov (United States)

    Breard, Emmanuel; Belbis, Guillaume; Viarouge, Cyril; Riou, Mickael; Desprat, Alexandra; Moreau, Joël; Laloy, Eve; Martin, Guillaume; Sarradin, Pierre; Vitour, Damien; Batten, Carrie; Doceul, Virginie; Sailleau, Corinne; Zientara, Stéphan

    2013-10-01

    Epizootic hemorrhagic disease virus (EHDV), an arthropod-borne orbivirus (family Reoviridae), is an emerging pathogen of wild and domestic ruminants closely related to bluetongue virus (BTV). EHDV serotype 6 (EHDV6) has recently caused outbreaks close to Europe in Turkey and Morocco and a recent experimental study performed on calves inoculated with these two EHDV6 strains showed that the young animals have remained clinically unaffected. The aim of this study was to investigate the pathogenicity of an EHDV6 strain from La Reunion Island in adult Holstein (18-month-old heifers). This EHDV6 strain has induced clinical signs in cattle in the field. Samples taken throughout the study were tested with commercially available ELISA and real-time RT-PCR kits. Very mild clinical manifestations were observed in cattle during the experiment although high levels of viral RNA and virus were found in their blood. EHDV was isolated from the blood of infected animals at 8 dpi. Antibodies against EHDV were first detected by 7 dpi and persisted up to the end of the study. Virus was detected in various tissue samples until 35 dpi, but was not infectious. In view of the recent circulation of different arboviruses in Europe, this study demonstrates what the EHD induces a strong viraemia in adult Holstein cattle and shows that a spread of EHD on European livestock cattle is possible. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Spatial Trend of Foot and Mouth Disease Virus (FMDV) Serotypes in Cattle and Buffaloes, Pakistan

    Institute of Scientific and Technical Information of China (English)

    Muhammad Abubakar; Muhammad Javed Arshed; Qurban Ali; Manzoor Hussain

    2012-01-01

    The present study describes the frequency of Foot and Mouth Disease (FMD) virus serotypes (O,A and Asia-1) in major regions (all provinces) of Pakistan using Indirect Sandwich ELISA.Also,spatial distribution of various FMD serotypes and their comparison is discussed.A total of 590 samples (Epithelial tissue) have been analyzed during a period of five years (2005-2009).Out of 590 samples,180 were found positive,giving an overall confirmation of FMDV about 33.2 %.Of the prevalent serotypes,FMDV ‘O’ serotype caused most outbreaks (20.7 %),followed by serotype A (6.6 %) and serotype Asia-1 (4.6 %) while there was no positive case of type ‘C’.The study clearly showed that the disease was more frequent in the agro-climatic zones than in hilly areas.Based on the data of 590 samples (>50 outbreaks),the overall prevalence of FMDV in cattle and buffaloes in Pakistan was 33.2 %,while in cattle alone,it was 37.1%,higher than in buffalo (28.7 %).There were eight cases of mixed serotypes infection,indicating the presence of endemic state of disease.Another significant feature was the change over time.In phase-I (2005-2007),there was an overall prevalence of 29.4 %,while the occurrence of the serotype O,A and Asia-1 was 20.4 %,2.9 % and 4.7 %,respectively.During phase-II (2008-2009),the overall prevalence was 59.21%,while those of serotype O,A and Asia-1 were 22.4 %,31.6 % and 4.0 %,respectively.This clearly indicated a shift from serotype O to A,which may help to explain the occurrence of more severe outbreaks,despite vaccination.

  19. Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

    OpenAIRE

    Guleria Randeep; Dar Lalit; Diddi Kavita; Pandey Anubhav; Chahar Harendra S; Bharaj Preeti; Kabra Sushil K; Broor Shobha

    2008-01-01

    Abstract Background Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating d...

  20. Cellulose-based diagnostic devices for diagnosing serotype-2 dengue fever in human serum.

    Science.gov (United States)

    Wang, Hsi-Kai; Tsai, Cheng-Han; Chen, Kuan-Hung; Tang, Chung-Tao; Leou, Jiun-Shyang; Li, Pi-Chun; Tang, Yin-Liang; Hsieh, Hsyue-Jen; Wu, Han-Chung; Cheng, Chao-Min

    2014-02-01

    Here, two types of cellulose-based in vitro diagnostic devices are demonstrated for the diagnosis of dengue virus infection in both buffer system and human serum: 1) paper-based ELISA for providing the semiquantitative information of the disease activity of serotype-2 dengue fever to healthcare persons (i.e., monitoring the disease activity with a specific serotype in single patients); 2) lateral flow immunoassays to screen for infection with serotype-2 dengue fever (i.e., rapid YES or NO diagnosis prepared for large populations, in terms of global public health). Paper-based ELISA (specific to serotype-2 dengue fever), which builds off of our previous studies and a revised previous ELISA procedure, owns multiple advantages: 1) high sensitivity (about 40 times higher than the current ELISA-based approaches, due to our therapeutic-based monoclonal antibody) and specificity (specific to dengue virus serotype-2 nonstructural protein-1 antigens); 2) tiny amount of sample and reagent used for single tests; 3) short operating duration (i.e., rapid diagnostic device); and, 4) inexpensiveness (appropriate for use in all developing and underdeveloped nations of the world). Due to the higher sensitivity and shorter operating duration of paper-based ELISA (compared with conventional ELISA, and lateral flow immunoassays also performed in this study), this study has not only been able to perform the diagnosis of dengue virus serotype-2 nonstructural protein-1 antigens in both buffer system and human serum but also to evaluate dengue virus serotype-2 envelope proteins in the buffer system, thus successfully achieving the first such use of these proteins as the target antigen for the development of diagnostic tools. These results provide a more comprehensive understanding for the genesis of dengue fever diagnostic tools (through antibody-antigen recognition).

  1. Phenotypes, genotypes, serotypes and molecular epidemiology of erythromycin-resistant Streptococcus agalactiae in Italy.

    Science.gov (United States)

    De Francesco, M A; Caracciolo, S; Gargiulo, F; Manca, N

    2012-08-01

    The purpose of this investigation was to analyse Streptococcus agalactiae (group B Streptococcus, GBS) isolates collected in Italy from vaginal and urine samples in respect to their clonality, distribution of virulence factors and antimicrobial resistance determinants. Three hundred and eighty-eight GBS were recovered from clinical samples. They were analysed for antibiotic resistance profiling. Erythromycin-resistant strains were further characterised by multilocus sequence typing (MLST), serotyping and the detection of alp genes of the alpha-like protein (Alp) family. GBS isolates represented 40 different sequence types (STs), grouped in five clonal complexes (CCs) and belonged to seven serotypes. Most serotype V strains (81%) possessed alp2-3; serotype Ia carried mainly epsilon, while the serotype III mainly rib. All isolates were susceptible to penicillin, whereas resistance to erythromycin was detected in 15% of isolates. Most erythromycin-resistant GBS strains were of serotype V (56.8%) and belonged to the CC-1 group (50%). Macrolide resistance phenotypes were the cMLS(B) (46.5%) and the M phenotypes (46.5%) due to the presence of ermB and mefA/E genes, respectively. These results provide data which establish a baseline for monitoring erythromycin resistance in this region and also provide an insight into the correlation among clonal types, serotypes, surface protein and resistance genes. The increased prevalence of strains that displayed the M phenotype strengthens the importance of the epidemiological surveillance of macrolide resistance in GBS, which may also represent an important reservoir of resistance genes for other species.

  2. Clonal expansion of the macrolide resistant ST386 within pneumococcal serotype 6C in France.

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    Claire Janoir

    Full Text Available In France, the use of the 7-valent pneumococcal conjugate vaccine (PCV7 lead to an overall significant decrease in PCV7 invasive pneumococcal disease (IPD incidence. However, the decrease in vaccine serotype prevalence was partially counterbalanced by the serotype replacement phenomenon. In this study, we analyzed the role of the newly described serotype 6C as one of the replacement serotypes. This work was conducted on a large time scale from the early PCV7 era (2002-2003 to the PCV13 era (2010-2011, both on IPD strains recovered from the whole population and nasopharyngeal colonizing strains isolated in infant less than two years, who are known to be the main reservoir for pneumococci. Serotype 6C took advantage over 6A and 6B serotypes, which both decreased over time. A continuous and significant increase in 6C IPD was observed in adults along the study period; in contrast, in children less than two years, only an increase in 6C nasopharyngeal carriage was found, the prevalence of serotype 6C in IPD remaining very low over time. Among 101 6C invasive and colonizing strains studied by MLST, 24 STs were found to be related to three major clonal complexes, CC395, CC176, and CC315. STs related to CC176 tend to disappear after 2009 and were essentially replaced by ST386 (CC315, which dramatically increased over time. This clonal expansion may be explained by the erythromycin and tetracycline resistances associated with this clone. Finally, the decrease observed in nasopharyngeal 6C carriage since 2010, likely related to the PCV13 introduction in the French immunization schedule, is expected to lead to a decrease in 6C IPD in adults thereafter.

  3. Distribution and content of class 1 integrons in different Vibrio cholerae O-serotype strains isolated in Thailand

    DEFF Research Database (Denmark)

    Dalsgaard, Anders; Forslund, Anita; Serichantalergs, Oralak

    2000-01-01

    In this study, 176 clinical and environmental Vibrio cholerae strains of different O serotypes isolated in Thailand from 1982 to 1995 were selected and studied for the presence of class 1 integrons, a new group of genetic elements which carry antibiotic resistance genes. Using PCR and DNA...... by the strains. Serotype O139 strains did not contain class 1 integrons. However, the appearance and disappearance of the O139 serotype in the coastal city Samutsakorn in 1992 and 1993 were associated with the emergence of a distinct V. cholerae O1 strain which contained the aad-V resistance gene cassette. A 150....... cholerae O serotypes of mainly clinical origin in Thailand....

  4. Serotype distribution, antimicrobial resistance, and molecular characterization of invasive group B Streptococcus isolates recovered from Chinese neonates

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    Ping Wang

    2015-08-01

    Conclusion: Serotype distribution, antimicrobial susceptibility, and sequence type characterization in Asia and in other global regions may contribute to improve the prevention and treatment of neonatal GBS infections.

  5. Distribution of serotypes, IS901 and a 40 kDa protein in Mycobacterium avium complex strains isolated from man and animals in Denmark

    DEFF Research Database (Denmark)

    Klausen, J.; Giese, Steen Bjørck; Fuursted, K.;

    1997-01-01

    The aim of the present study was to characterize all strains of the Mycobacterium avium complex isolated in Denmark in 1993. A total of 141 M. avium complex strains (86 from man, 38 from animals, and 17 from peat) were analysed by serotyping, ELISA specific for a 40 kDa protein, and IS901-specific...... prevalent serotypes among strains isolated from peat were serotype 4 (29%) and serotype 9 (18%). There was a concurrent appearance of IS901 and p40 in all strains. Only M. avium complex strains isolated from animals, and belonging to serotype 1 or serotype 2, contained the IS901/p40 markers. The different...

  6. Antigens of Streptococcus mutans: isolation of a serotype-specific and a cross-reactive antigen from walls of strain V-100 (serotype e).

    Science.gov (United States)

    Wetherell, J F; Bleiweis, A S

    1978-01-01

    Two cell wall-associated polysaccharide antigens were extracted from purified cell walls of Streptococcus mutans serotype e strain V-100. One of these purified antigens (I) is specific for serotype e, whereas the other (II) has antigenic determinants reactive with both heterologous anti-serotype c serum (GS-5) and the homologous (e) serum. When crude formamide extracts of V-100 cell walls were loaded onto a Cellex-D column and eluted with a linear gradient of ammonium carbonate (0.02 to 0.40 M), the two products mentioned above could be recovered. The purified, antigenically reactive products (I and II) were each composed only of rhamnose and glucose in approximately a 2:1 molar ratio. Immunoelectrophoresis of the crude formamide extract, peak I, and peak II showed the purified fractions to have opposite mobilities and the crude extract to have a mobility that encompassed both purified peaks when reacted with homologous antiserum (V-100). When these three fractions were immunoelectrophoresed and reacted with heterologous anti-serotype c serum (GS-5), only the anodic portion of the crude V-100 formamide extract and purified peak II formed precipitates. Ouchterlony analysis with homologous antiserum produced precipitin patterns between the crude formamide extract and both purified peaks, indicating complete identity. However, only crude extracts of V-100 and the purified peak II material reacted with heterologous (c) antiserum; peak I did not cross-react in these Ouchterlony assays. Hapten inhibition studies revealed that a beta-glucosyl moiety is the immunodeterminant for serotype e and is present on each purified fraction. The basis of the cross-reaction between anti-c sera and the purified antigen II of e is discussed.

  7. Serotype specific polymerase chain reaction identifies a higher prevalence of streptococcus mutans serotype k and e in a random group of children with dental caries from the Southern region of India

    Directory of Open Access Journals (Sweden)

    Arun Prasad Rao

    2014-01-01

    Full Text Available Background: The development of dental caries has been associated with the oral prevalence of Streptococcus mutans. Four serotypes of S. mutans have been reported, namely serotype c, e, f, and k that are classified based on the composition and linkages of cell wall polysaccharides, response to physiological reactions, sero-specificity and 16s rRNA homology. Although the oral prevalence of S. mutans serotype c in Indian subjects with or without caries is known, the prevalence of the other three serotypes, e, f, and k are not known. Hence in this study, we have investigated the occurrence of the e, f, and k serotypes in children with or without caries within the age group of 6-12 years. Materials and Methods: Genomic DNA isolated from whole saliva of caries active (CA and caries free (CF groups were first screened for the presence of S. mutans by strain specific polymerase chain reaction (PCR. Those samples that tested positive for the presence of S. mutans were further analyzed by serotype specific PCR to identify the prevalence of the serotypes. Results: Strain specific PCR indicated a higher prevalence of S. mutans in CA group (80% relative to CF group (43%. Further analysis of the S. mutans positive samples in both groups indicated a higher prevalence of serotype k and e, followed by serotype f in CA group. Conclusion: The present data clearly establishes a novel S. mutans serotype prevalence hierarchy in children from this region, compared with those that have been reported elsewhere. Besides, the data are also clinically significant as the occurrence of serotype k has been associated with infective endocarditis.

  8. Structure of human rhinovirus serotype 2 (HRV2).

    Science.gov (United States)

    Verdaguer, N; Blaas, D; Fita, I

    2000-07-28

    Human rhinoviruses are classified into a major and a minor group based on their binding to ICAM-1 or to members of the LDL-receptor family, respectively. They can also be divided into groups A and B, according to their sensitivity towards a panel of antiviral compounds. The structure of human rhinovirus 2 (HRV2), which uses the LDL receptor for cell attachment and is included in antiviral group B, has been solved and refined at 2.6 A resolution by X-ray crystallography to gain information on the peculiarities of rhinoviruses, in particular from the minor receptor group. The main structural differences between HRV2 and other rhinoviruses, including the minor receptor group serotype HRV1A, are located at the internal protein shell surface and at the external antigenic sites. In the interior, the N termini of VP1 and VP4 form a three-stranded beta-sheet in an arrangement similar to that present in poliovirus, although myristate was not visible at the amino terminus of VP4 in the HRV2 structure. The betaE-betaF loop of VP2, a linear epitope within antigenic site B recognized by monoclonal antibody 8F5, adopts a conformation considerably different from that found in the complex of 8F5 with a synthetic peptide of the same sequence. This either points to considerable structural changes impinged on this loop upon antibody binding, or to the existence of more than one single conformation of the loop when the virus is in solution. The hydrophobic pocket of VP1 was found to be occupied by a pocket factor apparently identical with that present in the major receptor group virus HRV16. Electron density, consistent with the presence of a viral RNA fragment, is seen stacked against a conserved tryptophan residue.

  9. Effects of crp deletion in Salmonella enterica serotype Gallinarum

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    Rubino Salvatore

    2007-05-01

    Full Text Available Abstract Background Salmonella enterica serotype Gallinarum (S. Gallinarum remains an important pathogen of poultry, especially in developing countries. There is a need to develop effective and safe vaccines. In the current study, the effect of crp deletion was investigated with respect to virulence and biochemical properties and the possible use of a deletion mutant as vaccine candidate was preliminarily tested. Methods Mutants were constructed in S. Gallinarum by P22 transduction from Salmonella Typhimurium (S. Typhimurium with deletion of the crp gene. The effect was characterized by measuring biochemical properties and by testing of invasion in a chicken loop model and by challenge of six-day-old chickens. Further, birds were immunized with the deleted strain and challenged with the wild type isolate. Results The crp deletions caused complete attenuation of S. Gallinarum. This was shown by ileal loop experiments not to be due to significantly reduced invasion. Strains with such deletions may have vaccine potential, since oral inoculatoin with S. Gallinarum Δcrp completely protected against challenge with the same dose of wild type S. Gallinarum ten days post immunization. Interestingly, the mutations did not cause the same biochemical and growth changes to the two biotypes of S. Gallinarum. All biochemical effects but not virulence could be complemented by providing an intact crp-gene from S. Typhimurium on the plasmid pSD110. Conclusion Transduction of a Tn10 disrupted crp gene from S. Typhimurium caused attenuation in S. Gallinarum and mutated strains are possible candidates for live vaccines against fowl typhoid.

  10. Subtyping of Salmonella Food Isolates Suggests the Geographic Clustering of Serotype Telaviv.

    Science.gov (United States)

    Durul, Bora; Acar, Sinem; Bulut, Ece; Kyere, Emmanuel O; Soyer, Yeşim

    2015-12-01

    Salmonella is commonly found in a variety of food products and is a major cause of bacterial foodborne illness throughout the world. In this study, we investigated the prevalence and diversity of Salmonella in eight different food types: sheep ground meat, cow ground meat, chicken meat, cow offal, traditional Sanliurfa cheese, unripened feta cheese, pistachios, and isot (a spice blend of dried red peppers specific to Sanliurfa), traditionally and commonly consumed in Turkey. Among 192 food samples, Salmonella was detected in 59 samples, with the highest prevalence in raw poultry parts (58%) and offal (58%) samples, while Salmonella was not detected in pistachios and dried red pepper. Resultant Salmonella isolates were characterized by serotyping, multilocus sequence typing (MLST), and pulsed-field gel electrophoresis (PFGE). Ten different serotypes represented 10 MLST sequence types (STs) with 1 novel ST and 17 PFGE types. Antimicrobial resistance profiling revealed that 30.5% of the isolates were resistant to two or more antimicrobials. Salmonella enterica subsp. enterica serotype Telaviv, which is rare throughout the world, was the second most common serotype isolated from food samples in this study, suggesting that this serotype might be one of the subtypes that is endemic to Turkey.

  11. Molecular typing, antibiotic resistance, virulence gene and biofilm formation of different Salmonella enterica serotypes.

    Science.gov (United States)

    Turki, Yousra; Mehr, Ines; Ouzari, Hadda; Khessairi, Amel; Hassen, Abdennaceur

    2014-01-01

    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.

  12. Serotype Prevalence and Penicillin-susceptibility of Streptococcus pneumoniae in Oman

    Directory of Open Access Journals (Sweden)

    Mubarak M. Al-Yaqoub

    2011-01-01

    Full Text Available Objectives: to determine the prevalent serotypes of Streptococcus pneumoniae and the rate of penicillin-nonsusceptibility among pneumococci in Oman.Methods: Pneumococcal isolates encountered during the period of September 2002 to December 2007 in the Royal Hospital were serotyped. Clinical information as well as the penicillin susceptibility reports were retrieved from the hospital information system and medical records.Results: 120 strains of Streptococcus pneumoniae were isolated of which 85 strains were seroptyped. 20 different serotypes were identified; the most common seroptypes were 9A, 6B, 19F, 14 and 23F. 56�0of the strains were not susceptible to pencillin, while 99�0of these were susceptible to ceftriaxone. 74.3�0and 46.1�0of the serotypes are covered by the pneumococcal polysaccharide vaccine and the 7-valent pneumococcal conjugate vaccine respectively.Conclusion: Certain few pneumococcal serotypes such as 9A, 6B and 19F are more prevalent in the Omani community than others. More than half of S. pneumoniae are not susceptible to penicillin while the great majority of the strains are susceptible to ceftriaxone.

  13. Serotype and genotype distribution among invasive Streptococcus pneumoniae isolates in Colombia, 2005-2010.

    Science.gov (United States)

    Parra, Eliana L; Ramos, Viviana; Sanabria, Olga; Moreno, Jaime

    2014-01-01

    In Colombia, a laboratory-based surveillance of invasive Streptococcus pneumoniae isolates as part of SIREVA II PAHO has been conducted since 1994. This study describes the serotype distribution, antimicrobial resistance, and genetic relationships of pneumococcal isolates recovered in Colombia from 2005 to 2010. In this study, demographic data of invasive S. pneumoniae isolates were analyzed, and antimicrobial susceptibility patterns were determined. Pulse field gel electrophoresis (n = 629) and multilocus sequence typing (n = 10) were used to determine genetic relationship of isolates with minimal inhibitory concentration to penicillin ≥0.125 µg/mL. A total of 1775 isolates of S. pneumoniae were obtained. Fifteen serotypes accounted for 80.7% of isolates. Serotype 14 (23.1%) was the most frequent in the general population. Penicillin resistance was 30.7% in meningitis and 9.0% in non-meningitis. Clones Spain(6B)ST90, Spain(9V)ST156, Spain(23F)ST81, and Colombia(23F)ST338 were associated to isolates. Additionally, serotype 6A isolates were associated with ST460 and ST473, and 19A isolates with ST276, ST320, and ST1118. In conclusion, the surveillance program provided updated information of trends in serotype distribution, antimicrobial resistance and the circulation of clones in invasive pneumococcal diseases. These results could be helpful to understand the epidemiology of S. pneumoniae in Colombia, and provide a baseline to measure the impact of vaccine introduction.

  14. DC-SIGN specifically recognizes Streptococcus pneumoniae serotypes 3 and 14.

    Science.gov (United States)

    Koppel, Estella A; Saeland, Eirikur; de Cooker, Désirée J M; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2005-01-01

    The Gram-positive bacterium Streptococcus pneumoniae is the leading causative pathogen in community-acquired pneumonia. The ever-increasing frequency of antibiotic-resistant S. pneumoniae strains severely hampers effective treatments. Thus, a better understanding of the mechanisms involved in the pathogenesis of pneumococcal disease is needed; in particular, of the initial interactions that take place between the host and the bacterium. Recognition of pathogens by dendritic cells is one of the most crucial steps in the induction of an immune response. For efficient pathogen recognition, dendritic cells express various kinds of receptors, including the DC-specific C-type lectin DC-SIGN. Pathogens such as Mycobacterium tuberculosis and HIV target DC-SIGN to escape immunity. Here the in vitro binding of DC-SIGN with S. pneumoniae was investigated. DC-SIGN specifically interacts with S. pneumoniae serotype 3 and 14 in contrast to other serotypes such as 19F. While the data described here suggest that DC-SIGN interacts with S. pneumoniae serotype 14 through a ligand expressed by the capsular polysaccharide, the binding to S. pneumoniae serotype 3 appears to depend on an as yet unidentified ligand. Despite the binding capacity of the capsular polysaccharide of S. pneumoniae 14 to DC-SIGN, no immunomodulatory effects on the dendritic cells were observed. The immunological consequences of the serotype-specific capacity to interact with DC-SIGN should be further explored and might result in new insights in the development of new and more potent vaccines.

  15. Biofilm formation of Salmonella serotypes in simulated meat processing environments and its relationship to cell characteristics.

    Science.gov (United States)

    Wang, Huhu; Ding, Shijie; Dong, Yang; Ye, Keping; Xu, Xinglian; Zhou, Guanghong

    2013-10-01

    Salmonella attached to meat contact surfaces encountered in meat processing facilities may serve as a source of cross-contamination. In this study, the influence of serotypes and media on biofilm formation of Salmonella was investigated in a simulated meat processing environment, and the relationships between biofilm formation and cell characteristics were also determined. All six serotypes (Salmonella enterica serotype Heidelberg, Salmonella Derby, Salmonella Agona, Salmonella Indiana, Salmonella Infantis, and Salmonella Typhimurium) can readily form biofilms on stainless steel surfaces, and the amounts of biofilms were significantly influenced by the serotypes, incubation media, and incubation time used in this study. Significant differences in cell surface hydrophobicity, autoaggregation, motility, and growth kinetic parameters were observed between individual serotypes tested. Except for growth kinetic parameters, the cell characteristics were correlated with the ability of biofilm formation incubated in tryptic soy broth, whereas no correlation with biofilm formation incubated in meat thawing-loss broth (an actual meat substrate) was found. Salmonella grown in meat thawing-loss broth showed a "cloud-shaped" morphology in the mature biofilm, whereas when grown in tryptic soy broth it had a "reticulum-shaped" appearance. Our study provides some practical information to understand the process of biofilm formation on meat processing contact surfaces.

  16. Identification and characterization of Salmonella serotypes using DNA spectral characteristics by fourier transform infrared

    Science.gov (United States)

    Sundaram, Jaya; Park, Bosoon; Hinton, Arthur; Yoon, Seung Chul; Lawrence, Kurt C.

    2012-05-01

    Analysis of DNA samples of Salmonella serotypes were performed using FT-IR spectrometer by placing directly in contact with a diamond attenuated total reflection (ATR) crystal. Spectra were recorded from 4000 cm-1 to 525 cm-1 wavenumber with the resolution of 4 cm-1 and data spacing of 1.928 cm-1. Collected spectra were subtracted from the background spectra of empty diamond crystal surface. Principal Component Analysis (PCA) was conducted at four different spectral regions to differentiate the different serotypes of Salmonella on the basis of difference in their spectral features of DNA structure macromolecules. PCA was used to show the natural clusters in the data set and to describe the difference between the sample clusters. At the region 1800 - 1200 cm-1, PC1 distinguished 93 % and PC2 distinguished 7 % of the serotypes. Therefore, maximum classification of 100 % in total was obtained at this region. For all the Salmonella serotypes, the frequency between 1000-1150 cm-1 and 1170 -1280 cm-1 had higher loading values which showed their significant contribution in the serotype classification.

  17. [Subtypes of dengue virus serotypes 2, 3 and 4 isolated in Santander District, Colombia].

    Science.gov (United States)

    Cortés, Fabián M; Gómez, Sergio Y; Ocazionez, Raquel E

    2007-01-01

    Virus serotypes 2, 3 and 4 that had circulated in Santander District, Colombia in the period 1998-2004 were analyzed. Identifying the subtype of a dengue virus serotype is a useful tool for surveillance of severe risk factors because the strain potential to cause hemorrhagic dengue makes the difference among them. Simultaneous sequence amplification technique known as restriction site specific-polymerase chain reaction (RSS-PCR) was used to determine the subtype by comparing the electrophoretic pattern of the local isolate to the reference virus. Virus serotype 2 corresponded to subtype A similar to the one isolated in Thailand (1996) and to the other isolated in Porto Rico (1986); virus serotypes 3 were of subtype C like the virus found in Sri Lanka (1990), Honduras (1995) and Porto Rico (2000); virus serotypes 4 were a variant of subtype B similar to a virus from Porto Rico (1987) and to another virus from Tahiti (1985). The study confirmed the presence in Colombia of dengue virus subtypes circulating now in the Americas.

  18. Serotype-specific identification of Dengue virus by silicon nanowire array biosensor.

    Science.gov (United States)

    Huang, Min Joon; Xie, Hui; Wan, Qiangqiang; Zhang, Li; Ning, Yong; Zhang, Guo-Jun

    2013-06-01

    In this work, we demonstrated a silicon nanowire (SiNW) biosensing platform capable of simultaneously identifying different Dengue serotypes on a single sensing chip. Four peptide nucleic acids (PNAs), specific to each Dengue serotypes (DENV-1 to DENV-4), were spotted on different areas of the SiNW array surface, and the covalently immobilized PNA probes were then interacted with different Dengue serotypes target to establish the specificity of detection. Detection scheme is based on the changes in resistances due to accumulation of negative charges contributed by the hybridized DNA target. The results show that resistance changes only occur in regions where the Dengue target hybridizes with its complementary probe. What is more, a mixture of two different Dengue serotypes obtained from a one-step duplex RT-PCR was applied to the multiplex SiNW surface to validate SiNW capability to identify multiple Dengue serotypes on a single sensing platform. Through this study, we have established the multiplex SiNW biosensor as a promising device to detect multiple Dengue infections with high specificity.

  19. Virulence traits and pathogenicity of uropathogenic Escherichia coli isolates with common and uncommon O serotypes.

    Science.gov (United States)

    Gao, Qingqing; Zhang, Debao; Ye, Zhengqin; Zhu, Xiaoping; Yang, Weixia; Dong, Lanmei; Gao, Song; Liu, Xiufan

    2017-03-01

    Urinary tract infections (UTIs) are among the most common human diseases worldwide. This study aimed to collect uropathogenic Escherichia coli (UPEC) isolates from Jiangsu Province and obtain insights into the molecular epidemiology of UPEC in this region. The O serotypes, phylogenetic groups, and virulence factors of 183 UPEC isolates were determined. In this study, we isolated 51 UPEC isolates with common O serotypes including O1, O2, O4, O6, O7, O16, O18 and O75, as well as 35 of those with uncommonly encountered O serotypes including O8, O12, O15, O26, and O74. Groups B2 and D were the most prevalent phylogenetic groups and accounted for 29.5% and 41% of the isolates, respectively. In the tested 13 virulence genes (VGs), tonB and dsdA possessed the highest prevalence rate, followed by fimH, degP and ompR. Several other virulence genes such as fliC, neuC, ireA, and vat had prevalence less than 23%. Moreover, representative isolates belonging to common or uncommon O serotypes with different numbers of VGs were chosen for the pathogenic analyses. Based on the results of 1-day-old chick lethality assay and UTI ascending mouse infection model, our study suggested that the virulence of UPEC isolates for chicks and/or mice depended on both the number of VGs expressed and the O serotypes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Clonality and serotypes of Streptococcus mutans among children by multilocus sequence typing

    Science.gov (United States)

    Momeni, Stephanie S.; Whiddon, Jennifer; Cheon, Kyounga; Moser, Stephen A.; Childers, Noel K.

    2015-01-01

    Studies using multilocus sequence typing (MLST) have demonstrated that Streptococcus mutans isolates are genetically diverse. Our laboratory previously demonstrated clonality of S. mutans using MLST but could not discount the possibility of sampling bias. In this study, the clonality of randomly selected S. mutans plaque isolates from African American children was examined using MLST. Serotype and presence of collagen-binding proteins (CBP) cnm/cbm were also assessed. One hundred S. mutans isolates were randomly selected for MLST analysis. Sequence analysis was performed and phylogenetic trees were generated using START2 and MEGA. Thirty-four sequence types (ST) were identified of which 27 were unique to this population. Seventy-five percent of the isolates clustered into 16 clonal groups. Serotypes observed were c (n=84), e (n=3), and k (n=11). The prevalence of S. mutans isolates serotype k was notably high at 17.5%. All isolates were cnm/cbm negative. The clonality of S. mutans demonstrated in this study illustrates the importance of localized populations studies and are consistent with transmission. The prevalence of serotype k, a recently proposed systemic pathogen, observed in this study is higher than reported in most populations and is the first report of S. mutans serotype k in a US population. PMID:26443288

  1. Serotype distribution of Streptococcus mutans a pathogen of dental caries in cardiovascular specimens from Japanese patients.

    Science.gov (United States)

    Nakano, Kazuhiko; Nemoto, Hirotoshi; Nomura, Ryota; Homma, Hiromi; Yoshioka, Hideo; Shudo, Yasuhiro; Hata, Hiroki; Toda, Koichi; Taniguchi, Kazuhiro; Amano, Atsuo; Ooshima, Takashi

    2007-04-01

    The involvement of oral bacteria in the pathogenesis of cardiovascular disease has been studied, with Streptococcus mutans, a pathogen of dental caries, detected in cardiovascular lesions at a high frequency. However, no information is available regarding the properties of S. mutans detected in those lesions. Heart valve specimens were collected from 52 patients and atheromatous plaque specimens from 50 patients, all of whom underwent cardiovascular operations, and dental plaque specimens were taken from 41 of those subjects prior to surgery. Furthermore, saliva samples were taken from 73 sets of healthy mothers (n=73) and their healthy children (n=78). Bacterial DNA was extracted from all specimens, then analysed by PCR with S. mutans-specific and serotype-specific primer sets. The detection rates of S. mutans in the heart valve and atheromatous plaque specimens were 63 and 64 %, respectively. Non-c serotypes were identified with a significantly higher frequency in both cardiovascular and dental plaque samples from the subjects who underwent surgery as compared to serotype c, which was detected in 70-75 % of the samples from the healthy subjects. The serotype distribution in cardiovascular patients was significantly different from that in healthy subjects, suggesting that S. mutans serotype may be related to cardiovascular disease.

  2. Human rotavirus K8 strain represents a new VP4 serotype.

    Science.gov (United States)

    Li, B; Larralde, G; Gorziglia, M

    1993-01-01

    The complete VP4 gene of the human rotavirus (HRV) K8 strain (G1 serotype) was cloned and inserted into the baculovirus transfer vector pVL941 under the control of the polyhedrin promoter. A K8VP4 recombinant baculovirus was obtained by cotransfection of Spodoptera frugiperda (Sf9) cells with transfer vector DNA containing the K8VP4 gene and wild-type baculovirus DNA. Infection of Sf9 cells with this VP4 recombinant baculovirus resulted in the production of a protein that is similar in size and antigenic activity to the authentic VP4 of the K8 strain. Guinea pigs immunized with the expressed VP4 developed antibodies that neutralized the infectivity of the K8 strain. This antiserum neutralized HRV strains belonging to VP4 serotypes 1A, 1B, and 2 with efficiency eightfold or lower than that of the homologous virus, indicating that the human rotavirus K8 strain represents a distinct VP4 serotype (P3). In addition, low levels of cross-immunoprecipitation of the K8VP4 and its VP5 and VP8 subunits with hyperimmune antisera to HRV strains representing different VP4 serotype specificities also suggested that the K8 strain possesses a unique VP4 with few epitopes in common with other P-serotype strains. Images PMID:8380098

  3. Streptococcus pneumoniae nasopharyngeal carriage prevalence, serotype distribution, and resistance patterns among children on Lombok Island, Indonesia.

    Science.gov (United States)

    Soewignjo, S; Gessner, B D; Sutanto, A; Steinhoff, M; Prijanto, M; Nelson, C; Widjaya, A; Arjoso, S

    2001-04-01

    Few data exist on childhood pneumococcal carriage prevalence, serotype distribution, and resistance patterns for Indonesia, the world's fourth most populous country. During August 1997, nasopharyngeal samples were collected from a population-based, island-wide sample of 484 healthy children (age, 0-25 months) from Lombok Island, Indonesia. Two hundred twenty-one pneumococcal isolates were identified, for a carriage prevalence of 48%; 66% of isolates were of serogroup or serotype 6, 23, 15, 33, or 12. All isolates were susceptible to penicillin and cefotaxime. Twelve percent of the isolates were nonsusceptible to sulfamethoxazole or chloramphenicol and 4% were nonsusceptible to both of these drugs. Nonsusceptible organisms were most frequently serogroup or serotype 6, 12, and 33. Lombok has a moderate pneumococcal carriage prevalence and a relatively low proportion of resistant isolates. At least 3 of the 5 most common serogroups and serotypes and 2 of the 3 most common nonsusceptible serogroups and serotypes are not included in the current 7-valent pneumococcal conjugate vaccine.

  4. Neural Network Model for Survival and Growth of Salmonella enterica Serotype 8,20:-:z6 in Ground Chicken Thigh Meat during Cold Storage: Extrapolation to Other Serotypes.

    Science.gov (United States)

    Oscar, T P

    2015-10-01

    Mathematical models that predict the behavior of human bacterial pathogens in food are valuable tools for assessing and managing this risk to public health. A study was undertaken to develop a model for predicting the behavior of Salmonella enterica serotype 8,20:-:z6 in chicken meat during cold storage and to determine how well the model would predict the behavior of other serotypes of Salmonella stored under the same conditions. To develop the model, ground chicken thigh meat (0.75 cm(3)) was inoculated with 1.7 log Salmonella 8,20:-:z6 and then stored for 0 to 8 -8 to 16°C. An automated miniaturized most-probable-number (MPN) method was developed and used for the enumeration of Salmonella. Commercial software (Excel and the add-in program NeuralTools) was used to develop a multilayer feedforward neural network model with one hidden layer of two nodes. The performance of the model was evaluated using the acceptable prediction zone (APZ) method. The number of Salmonella in ground chicken thigh meat stayed the same (P > 0.05) during 8 days of storage at -8 to 8°C but increased (P < 0.05) during storage at 9°C (+0.6 log) to 16°C (+5.1 log). The proportion of residual values (observed minus predicted values) in an APZ (pAPZ) from -1 log (fail-safe) to 0.5 log (fail-dangerous) was 0.939 for the data (n = 426 log MPN values) used in the development of the model. The model had a pAPZ of 0.944 or 0.954 when it was extrapolated to test data (n = 108 log MPN per serotype) for other serotypes (S. enterica serotype Typhimurium var 5-, Kentucky, Typhimurium, and Thompson) of Salmonella in ground chicken thigh meat stored for 0 to 8 days at -4, 4, 12, or 16°C under the same experimental conditions. A pAPZ of ≥0.7 indicates that a model provides predictions with acceptable bias and accuracy. Thus, the results indicated that the model provided valid predictions of the survival and growth of Salmonella 8,20:-:z6 in ground chicken thigh meat stored for 0 to 8 days at -8 to

  5. Complete genome sequence of avian paramyxovirus (APMV serotype 5 completes the analysis of nine APMV serotypes and reveals the longest APMV genome.

    Directory of Open Access Journals (Sweden)

    Arthur S Samuel

    Full Text Available BACKGROUND: Avian paramyxoviruses (APMV consist of nine known serotypes. The genomes of representatives of all APMV serotypes except APMV type 5 have recently been fully sequenced. Here, we report the complete genome sequence of the APMV-5 prototype strain budgerigar/Kunitachi/74. METHODOLOGY/PRINCIPAL FINDINGS: APMV-5 Kunitachi virus is unusual in that it lacks a virion hemagglutinin and does not grow in the allantoic cavity of embryonated chicken eggs. However, the virus grew in the amniotic cavity of embryonated chicken eggs and in twelve different established cell lines and two primary cell cultures. The genome is 17,262 nucleotides (nt long, which is the longest among members of genus Avulavirus, and encodes six non-overlapping genes in the order of 3'N-P/V/W-M-F-HN-L-5' with intergenic regions of 4-57 nt. The genome length follows the 'rule of six' and contains a 55-nt leader sequence at the 3'end and a 552 nt trailer sequence at the 5' end. The phosphoprotein (P gene contains a conserved RNA editing site and is predicted to encode P, V, and W proteins. The cleavage site of the F protein (G-K-R-K-K-R downward arrowF conforms to the cleavage site motif of the ubiquitous cellular protease furin. Consistent with this, exogenous protease was not required for virus replication in vitro. However, the intracerebral pathogenicity index of APMV-5 strain Kunitachi in one-day-old chicks was found to be zero, indicating that the virus is avirulent for chickens despite the presence of a polybasic F cleavage site. CONCLUSIONS/SIGNIFICANCE: Phylogenetic analysis of the sequences of the APVM-5 genome and proteins versus those of the other APMV serotypes showed that APMV-5 is more closely related to APMV-6 than to the other APMVs. Furthermore, these comparisons provided evidence of extensive genome-wide divergence that supports the classification of the APMVs into nine separate serotypes. The structure of the F cleavage site does not appear to be a

  6. Endocarditis with ruptured sinus of Valsalva aneurysm caused by nonvaccine Streptococcus pneumoniae serotype 21.

    Science.gov (United States)

    Patra, Kamakshya P; Vanchiere, John A; Bocchini, Joseph A; Wu, Amy C; Jackson, Robert D; Kiel, Ernest A; Mello, Dennis

    2012-01-01

    Sinus of Valsalva aneurysm is a rare, catastrophic complication of endocarditis. We report an unusual case of ruptured sinus of Valsalva aneurysm associated with endocarditis that was caused by Streptococcus pneumoniae serotype 21. The patient, a 12-year-old girl, underwent surgical repair of the aneurysm and was given intravenous antibiotics for 6 weeks. She was doing well at the 6-week follow-up visit. This case is unusual because of the patient's young age at presentation, the absence of predisposing factors, and the isolation of a nonvaccine serotype 21, which revealed the epidemiologic changes of invasive pneumococcal disease. To our knowledge, this is the first reported case of endocarditis caused by this S. pneumoniae serotype.

  7. Comparison of virulence of different Actinobacillus pleuropneumoniae serotypes and biotypes using an aerosol infection model

    DEFF Research Database (Denmark)

    Jacobsen, Mariann Juul; Nielsen, Jens Peter; Nielsen, Ragnhild

    1996-01-01

    An aerosol infection model for inoculation of pigs with Actinobacillus pleuropneumoniae is described, With this model the virulence of three A. pleuropneumoniae biotype 1 strains representing serotypes 2, 5b and 6, and one Danish biotype 2 were compared using 13-week-old pigs for inoculation...... lesions was 10(9) CFU/ml. Repeated experiments confirmed these results showing similar virulence of serotypes 2, 5b and 6 whereas the biotype 2 strain proved less virulent, The aerosol infection model allowed a comparison of the number of A. pleuropneumoniae CFU/liter air which were necessary to induce...... lung lesions in susceptible pigs, This indicates that the model will be well suited for virulence studies of A. pleuropneumoniae serotypes in pigs....

  8. Experimental vaccination of pigs with an Actinobacillus pleuropneumoniae serotype 5b capsular polysaccharide tetanus toxoid conjugate

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Jacobsen, M.J.; Nielsen, J.P.

    1997-01-01

    The protective efficacy of an Actinobacillus pleuropneumoniae serotype 5b capsular polysaccharide-tetanus toroid conjugate (Ap5bCP-TT) against homologous challenge of pigs was investigated. Four pigs were non-vaccinated controls (group A), 4 pigs were injected with adjuvant without antigen (group B......) and 8 pigs were vaccinated with Ap5bCP-TT and adjuvant (group 0). Pigs vaccinated with Ap5bCP-TT developed antibody responses to the capsular polysaccharide from A. pleuropneumoniae serotype 5b (Ap5bCP). After challenge, all pigs in groups A and B had severe clinical signs of disease and were euthanized...... and pulmonary lesions caused by experimental infection with A. pleuropneumoniae serotype 5b....

  9. Shift in serotype distribution of Shigella species in China, 2003-2013.

    Science.gov (United States)

    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

    2015-03-01

    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.

  10. Dengue Virus Serotypes Circulating in Khyber Pakhtunkhwa Province, Pakistan, 2013-2015.

    Science.gov (United States)

    Suleman, Muhammad; Faryal, Rani; Alam, Muhammad Masroor; Sharif, Salmaan; Shaukat, Shahzad; Aamir, Uzma Bashir; Khurshid, Adnan; Angez, Mehar; Umair, Massab; Sufian, Mian Muhammad; Arshad, Yasir; Zaidi, Syed Sohail Zahoor

    2017-03-01

    From 2013 to 2015, the National Institute of Health, Pakistan, received 1,270 blood samples of suspected dengue cases reported from inpatient and outpatient departments of various hospitals in Khyber Pakhtunkhwa (KPK) province. In this study, we determined the circulating dengue virus (DENV) serotypes using real-time reverse transcriptase (RT)-PCR to understand the serotype-based epidemiology of DENV. All four serotypes (DENV-1 [6%], DENV-2 [33%], DENV-3 [47%], and DENV-4 [0.1%]) were found circulating during the study period. Our findings suggest the need for an active surveillance system coupled with the laboratory diagnosis, especially in the chronic endemic areas of the country. Public awareness programs are needed for effective control and prevention of outbreaks in the future.

  11. Serotype distribution and antimicrobial resistance of invasive and noninvasive pneumococcal isolates in Tunisia.

    Science.gov (United States)

    Marzouk, Manel; Ferjani, Asma; Bouafia, Nabiha; Harb, Hanen; Ben Salem, Youssef; Boukadida, Jalel

    2015-02-01

    Pneumococcal conjugate vaccines have not yet been introduced into the national program for childhood vaccination in Tunisia. The aim of this 7-year study was to obtain local data about serotype distribution and antimicrobial resistance of Streptococcus pneumoniae. A total of 203 isolates of culture confirmed that S. pneumoniae was evaluated. Invasive (n=108) and noninvasive (n=95) pneumococcal isolates were obtained from patients aged from 1 month to 85 years old. Considering all age groups, vaccine coverage was 40%, 62%, and 68% for PCV7, PCV10, and PCV13 serotypes, respectively. Overall, 31% of these isolates were penicillin G nonsusceptible. The most prevalent serotypes identified were those found in currently available pneumococcal conjugate vaccines, emphasizing the importance of implementing the vaccine in the routine immunization schedule at the national level.

  12. Simultaneous circulation of all four dengue serotypes in Manaus, State of Amazonas, Brazil in 2011

    Directory of Open Access Journals (Sweden)

    Michele de Souza Bastos

    2012-06-01

    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.

  13. [Occurrence of Tsutsugamushi disease infection by Orientia tsutsugamushi, Kawasaki serotype, in Yamagata Prefecture, Japan].

    Science.gov (United States)

    Otani, Katsumi; Kaneko, Akiko; Aoki, Toshiya; Murata, Toshio

    2009-09-01

    Of 95 Tsutsugamushi disease case occurring in Yamagata prefecture from 1999 to 2006, four-all women-involved the O. tsutsugamushi Kawasaki serotype. The three major symptoms were fever, exanthema, and eschar present from mid-October to early November. Serodiagnosis by indirect immunofluoresence assay showed elevated IgG and IgM antibody titers against the Kawasaki serotype antigen, with IgM higher than IgG. Nested PCR detected 56-kDa DNA in three of the cases. DNA was amplified in Kawasaki-specific PCR. Two cases for which sequencing was done using nested PCR-amplified DNA showed an identity of 99.8% for the Kawasaki strain (Accession number: M63383). These results confirmed the occurrence of Tsutsugamushi disease infection involving Kawasaki serotype in Yamagata prefecture.

  14. Characterization of Streptococcus suis through serotyping, SE-AFLP and virulence profile

    Directory of Open Access Journals (Sweden)

    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.

  15. Recurrent Invasive Pneumococcal Disease Serotype 12F in a Vaccinated Splenectomized Patient

    DEFF Research Database (Denmark)

    Blaabjerg, Anne Katrine; Schumacher, Anna Holst; Kantsø, Bjørn

    2016-01-01

    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...... that she had responded sufficiently to vaccination. Still, she had a fulminate recurrent infection with PPV23 serotype 12F. We investigated the anti-pneumococcal IgG test, and it turned out that it is based on the geometric mean value of only 12 of the serotypes included in PPV23; 12F is none of them...... vaccines, in order to get a more accurate estimation of the vaccination coverage for the individual patient. Therefore, more research on this area is warranted, along with a discussion of whether the laboratory answers to the clinicians should be more detailed....

  16. Haemophilus influenzae serotype a as a cause of serious invasive infections.

    Science.gov (United States)

    Ulanova, Marina; Tsang, Raymond S W

    2014-01-01

    Haemophilus influenzae, particularly H influenzae serotype b (Hib), is an important pathogen that causes serious diseases like meningitis and septicaemia. Since the introduction of Hib conjugate vaccines in the 1990s, the epidemiology of invasive H influenzae disease has changed substantially, with most infections now caused by non-Hib strains. We discuss the importance of H influenzae serotype a (Hia) as a cause of serious morbidity and mortality and its global epidemiology, clinical presentation, microbiology, immunology, prevention, and control. Much like Hib, the capsule of Hia is an important virulence factor contributing to the development of invasive disease. Molecular typing of Hia has identified distinct clonal groups, with some linked to severe disease and high case-fatality rates. Similarities between Hia and Hib capsules, their clinical presentation, and immunology of infection suggest that a bivalent Hia-Hib capsular polysaccharide-protein conjugate vaccine could offer protection against these two important serotypes of H influenzae.

  17. Does age acquired immunity confer selective protection to common serotypes of Campylobacter jejuni?

    Directory of Open Access Journals (Sweden)

    Ogden Iain D

    2005-08-01

    Full Text Available Abstract Background Campylobacter infection is a major cause of bacterial gastrointestinal disease. Exposure to Campylobacter is known to produce an immune response in humans that can prevent future symptomatic infections. Further, studies of the general population have shown that seroprevalence to Campylobacter increases with age. Methods A large collection of serotyped Campylobacter isolates, obtained from human clinical faecal samples, were analysed by comparing the ratio of uncommon to common serotypes by different age groups, using χ2 tests. Results We have identified that older age groups, as well as having generally lower incidence, are significantly less likely to be infected by the more common serotypes. Conclusion These results are indicative of acquired immunity, however, further studies are needed to rule out the confounding effects of the variations in exposure pathways experienced by different age groups.

  18. Pediatric invasive pneumococcal disease caused by vaccine serotypes following the introduction of conjugate vaccination in Denmark.

    Directory of Open Access Journals (Sweden)

    Zitta B Harboe

    Full Text Available 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 PCV7 in the program, mainly due to a decline in IPD caused by PCV7-serotypes. We report the results from a nationwide population-based cohort study of laboratory confirmed IPD cases in children younger than 5 years during October 1, 2007 to December 31, 2010 and describe the characteristics 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 and 23F. One case of vaccine failure was observed in a severely immunosuppressed child following three PCV7 doses, and two cases were observed in immunocompetent children following two infant doses before they were eligible for their booster. None of the IPD cases caused by the additional PCV13 serotypes had been vaccinated by PCV13 and there were therefore no PCV13-vaccine failures in the first 8-months after PCV13 introduction in Denmark.

  19. Identification of the serotypes of bacterial meningitis agents; implication for vaccine usage.

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Attarpour-Yazdi

    2014-08-01

    Full Text Available Bacterial meningitis is one of the most serious infections and should be treated as emergency. As it has significant morbidity and mortality throughout the world, every country should have precise information regarding the etiological agents of disease and populations at risk to design public health prevention strategy. In the present study in addition of evaluation of common etiological agents (Haemophilus influenzae, Neisseria meningitidis, and Streptococcus pneumoniae in bacterial meningitis cases, we sero-grouped or serotyped the obtained agents in order to predict the usefulness of existing vaccines against bacterial meningitis.Cerebrospinal fluid of 182 suspected meningitis patients were collected, from which 114 cases were approved by biochemical, microbiological and molecular tests as bacterial meningitis. The isolated bacteria were serogrouped or serotyped to determine the dominant serotypes.Streptococcus pneumoniae accounted for 36%, Haemophilus influenza for 26% and Neisseria meningitidis for 14% of cases. From 13 serogroups of N. meningitides the most frequent serogroups, were meningococcus group B (51%, C(24% A (18%, Z(2%, W135 (1% and 3% was not identified. In H. influenzae group only serotype b (100% have been identified and in pneumococcal meningitis the most common serotype among our cases were 18C (44% followed by14 (17%, 19A (13%, 6A (9%, 7F (4%, 4(3%, 3 (3%, 9V (2%, 8 (2%, 23f (2%, 5 (1%.Since there is no nationwide mass immunization program for common agents of bacterial meningitis in Iran, the result of this study can be used to improve the existing vaccines to cover the detected serotypes and consequently reduce the incidence of bacterial meningitis.

  20. Structure-function investigation of vsp serotypes of the spirochete Borrelia hermsii.

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    Rohit Mehra

    Full Text Available BACKGROUND: Relapsing fever (RF spirochetes are notable for multiphasic antigenic variation of polymorphic outer membrane lipoproteins, a phenomenon responsible for immune evasion. An additional role in tissue localization is suggested by the finding that isogenic serotypes 1 (Bt1 and 2 (Bt2 of the RF spirochete Borrelia turicatae, which differ only in the Vsp they express, exhibit marked differences in clinical disease severity and tissue localization during infection. METHODOLOGY/PRINCIPAL FINDINGS: Here we used known vsp DNA sequences encoding for B. turicatae and Borrelia hermsii Vsp proteins with variable regions and then studied whether there are differences in disease expression and tissue localization of their corresponding serotypes during mouse infection. For sequence and structural comparisons we focused exclusively on amino acid residues predicted to project away from the spirochetes surface, referred to as the Vsp dome. Disease severity and tissue localization were studied during persistent infection with individual or mixed serotypes in SCID mice. The results showed that all Vsp domes clustered into 3 main trunks, with the domes for B. turicatae Vsp1 (BtVsp1 and BtVsp2 clustering into separate ones. B. hermsii serotypes whose Vsp domes clustered with the BtVsp1 dome were less virulent but localized to the brain more. The BtVsp2 dome was the oddball among all and Bt2 was the only serotype that caused severe arthritis. CONCLUSION/SIGNIFICANCE: These findings indicate that there is significant variability in Vsp dome structure, disease severity, and tissue localization among serotypes of B. hermsii.

  1. Streptococcus pneumoniae from Palestinian nasopharyngeal carriers: serotype distribution and antimicrobial resistance.

    Directory of Open Access Journals (Sweden)

    Abedelmajeed Nasereddin

    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.

  2. Hemagglutinin gene shuffling among Clostridium botulinum serotypes C and D yields distinct sugar recognition of the botulinum toxin complex.

    Science.gov (United States)

    Miyata, Keita; Suzuki, Tomonori; Hayashi, Shintaro; Miyashita, Shin-Ichiro; Ohyama, Tohru; Niwa, Koichi; Watanabe, Toshihiro; Sagane, Yoshimasa

    2015-10-01

    Clostridium botulinum strains produce a large-sized toxin complex (TC) that is composed of botulinum neurotoxin (BoNT), non-toxic non-hemagglutinin and three different hemagglutinins (HA-70, HA-33 and HA-17). HA components enhance toxin delivery across the intestinal cell wall in a sugar chain-dependent manner. Here we characterized the sugar recognition of serotype D strain 1873 (D-1873) botulinum L-TC. Most L-TCs produced by serotype C and D strains bind to cells via interactions between HA-33 and cell surface sialo-oligosaccharides. However, like the previously reported L-TC produced by serotype C strain Yoichi (C-Yoichi), D-1873 L-TC binds only to cells that have been treated with neuraminidase, indicating that they recognize asialo-oligosaccharides. The D-1873 HA-33 amino acid sequence is similar to that of C-Yoichi, but had lower similarity to the majority of serotype C and D HA-33s. A comparison of TC component primary structures for 12 serotype C and D strains suggested that at least three types of HA-33 genes exist, and these are shuffled among the serotype C and D strains independently of BoNT serotype. This shuffling produces the distinct sugar recognition of serotype C and D botulinum TCs.

  3. Effect of tulathromycin on the carrier status of Actinobacillus pleuropneumoniae serotype 2 in the tonsils of pigs

    DEFF Research Database (Denmark)

    Angen, Øystein; Andreasen, M.; Nielsen, E.O.

    2008-01-01

    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...

  4. Population Structure of Listeria monocytogenes Serotype 4b Isolates from Sporadic Human Listeriosis in the United States, 2003-2008

    Science.gov (United States)

    Listeria monocytogenes can cause severe foodborne disease (listeriosis). Serotype 4b strains have resulted in numerous outbreaks, repeatedly involving three epidemic clones (ECI, ECII, and ECIa). Little is known about population structure of L. monocytogenes serotype 4b from sporadic listeriosis, ev...

  5. National Department of Defense Surveillance for Invasive Streptococcus Pneumoniae: Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain Reaction Analyses

    Science.gov (United States)

    2008-02-15

    penicillin -susceptible and peni- cillin-resistant Streptococcnspneuttmoniae serotypes in Canada. J Infect Dis Streptococcus pneumoniae Surveillance Group...Gray for the Streptococcus pneumonia Surveillance Group Report No. 00-44 Approved for public release; distribution unlimited. NAVAL HEALTH RESEARCH...Defense Surveillance for Invasive Streptococcus pneumoniae : Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain

  6. Characterization of monoclonal antibodies to Streptococcus mutans antigenic determinants I/II, I, II, and III and their serotype specificities.

    Science.gov (United States)

    Smith, R; Lehner, T; Beverley, P C

    1984-10-01

    Monoclonal antibodies (McAb) were developed to four protein components of Streptococcus mutans serotype c, some of which are significant in the protection against dental caries. The six McAb used in this investigation support the identities of streptococcal antigens (SA) I/II, I, II, and III. The specificities of these antigenic determinants were established both by direct binding and inhibition with the pure SA with a solid-phase radioassay. Whereas conventional antisera to S. mutans serotype c cross-react with serotypes c, e, and f (and g), McAb to serotype c-derived SA I/II react predominantly with serotype c and show some low-titer reactivity with serotype f. The slight cross-reactivity between S. mutants cells of serotypes c and f could be further differentiated by absorption of any of the three McAb to SA I/II with cells of serotype c. Parallel studies of McAb with cells of S. mutans and their ammonium sulfate-precipitated culture supernatants suggest that some SA determinants are retained predominantly on the cell surface, but others are readily shed into the culture medium, so that they are detected both on the cell surface and culture medium. Unlike polyclonal antibodies, McAb are capable of discriminating single antigenic determinants and can be applied to the study of shedding of antigens from microorganisms into the environment, such as the gut or gingival sulcus.

  7. Studies of the Antigenic relationships between Bluetongue virus serotypes 2, 9 AND 15 isolated in Andhra Pradesh, India

    Directory of Open Access Journals (Sweden)

    Sreenivasulu Daggupati

    Full Text Available The presence of multiple serotypes of the midge-borne bluetongue virus and lack of effective vaccine are the major impediments in controlling bluetongue in sheep. Attempts are being made to develop a vaccine employing the available serotypes to control the disease in the state. Hence, it is essential to identify the antigenic relationships among the serotypes to identify the candidate strains to be incorporated in the preparation of vaccine. To understand the antigenic relationships between Bluetongue virus -2, 9 and 15 serotypes, the viruses were propagated in BHK21 cell lines, purified using PEG precipitation method and purified virus used to raise hyper immune serum in rabbits. Neutralizing antibodies for the BTV serotypes were detected by day 21 PI. Reciprocal cross neutralization test was employed to determine the R% values between BTV-2, 9 and 15 which indicated the extent of antigenic relationships among the serotypes. R% value between BTV-2 and BTV-9 was recorded as 2.8. R% value of 3.53 and 2.8 were observed between BTV-2 & 15 and BTV-9 & 15 respectively. The R% values recorded in the present study revealed a weak antigenic relationship between the BTV serotypes,indicating that the serotypes are highly divergent. [Vet. World 2011; 4(10.000: 444-448

  8. Effect of Culicoides sonorensis salivary proteins on clinical disease outcome in experimental Bleutongue virus serotype 8 infection of Dorset sheep

    NARCIS (Netherlands)

    Drolet, B.S.; Reister, L.M.; Lehiy, C.J.; Rijn, van P.A.; Bowen, R.A.

    2015-01-01

    The severity of Bluetongue clinical disease in ruminants varies greatly depending on the outbreak serotype/strain, animal species/breed, and immune status of the herd. To predict disease risk from any of the 26 Bluetongue virus (BTV) serotypes identified to date, experimental animal susceptibility s

  9. Variation in antigen-antibody affinity among serotypes of Salmonella O4 serogroup, determined using specific antisera.

    Science.gov (United States)

    Aribam, Swarmistha Devi; Elsheimer-Matulova, Marta; Matsui, Hidenori; Hirota, Jiro; Shiraiwa, Kazumasa; Ogawa, Yohsuke; Hikono, Hirokazu; Shimoji, Yoshihiro; Eguchi, Masahiro

    2015-11-01

    Serotyping is widely used for typing Salmonella during surveillance, and depends on determining the lipopolysaccharide (LPS) O-antigen and the flagellar protein (H-antigens) components. As the O-antigen is highly variable, and structurally unique to each serotype, we investigated the binding affinities of LPS from Salmonella serotypes of O4 serogroup with specific anti-antigen serum via immunoblot and enzyme-linked immunosorbent assays. Since the serotypes from O4 serogroup also express the O-antigen factor 12, O12 antiserum was also used for the analysis. LPS from the different serotypes showed different binding affinities with the antisera. Therefore, based on the antigen-antibody affinity, a modified agglutination assay was carried out by using O4 and O12 antisera. Although serotypes from O4 serogroup have the common O-antigen factors 4 and 12, the analysis showed that the degree of agglutination reaction is different for each of the serotypes. We suggest that Salmonella serogroup O4 serotypes exhibit different binding affinities with specific antisera despite the presence of common O-antigen factors 4 and 12.

  10. A simulated metagenomic approach for bacterial serotyping using shotgun genome sequences coupled with O-Antigen gene cluster analysis

    Science.gov (United States)

    Background: Accurate determination of food-borne pathogen serotype and genotype information is important for disease surveillance and outbreak source tracking. E. coli serotype O157:H7 and non-O157 of Shiga toxin-producing E. coli (STEC) serogroups, including O26, O45, O103, O111, O121, O145 (top ...

  11. Complete Genome Sequence of the Avian Paramyxovirus Serotype 5 Strain APMV-5/budgerigar/Japan/TI/75

    Science.gov (United States)

    Hiono, Takahiro; Matsuno, Keita; Tuchiya, Kotaro; Lin, Zhifeng; Okamatsu, Masatoshi

    2016-01-01

    Here, we report the complete genome sequence of the avian paramyxovirus serotype 5 strain APMV-5/budgerigar/Japan/TI/75, which was determined using the Illumina MiSeq platform. The determined sequence shares 97% homology and similar genetic features with the previously known genome sequence of avian paramyxovirus serotype 5 strain APMV-5/budgerigar/Japan/Kunitachi/74. PMID:27660785

  12. Both ApxI and ApxII of Actinobacillus pleuropneumoniae serotype 1 are necessary for full virulence

    NARCIS (Netherlands)

    Boekema, B.K.H.L.; Kamp, E.M.; Smits, M.A.; Smith, H.E.; Stockhofe-Zurwieden, N.

    2004-01-01

    Most serotypes of A. pleuropneumoniae produce more than one toxin in vivo. To determine the value of the production of more than one toxin in the development of disease, we tested the pathogenicity of isogenic strains of A. pleuropneumoniae serotype 1 that are mutated in the toxin genes apxIA and/or

  13. Effect of Culicoides sonorensis salivary proteins on clinical disease outcome in experimental Bleutongue virus serotype 8 infection of Dorset sheep

    NARCIS (Netherlands)

    Drolet, B.S.; Reister, L.M.; Lehiy, C.J.; Rijn, van P.A.; Bowen, R.A.

    2015-01-01

    The severity of Bluetongue clinical disease in ruminants varies greatly depending on the outbreak serotype/strain, animal species/breed, and immune status of the herd. To predict disease risk from any of the 26 Bluetongue virus (BTV) serotypes identified to date, experimental animal susceptibility

  14. Associations of Streptococcus suis serotype 2 ribotype profiles with clinical disease and antimicrobial resistance

    DEFF Research Database (Denmark)

    Rasmussen, S. R.; Aarestrup, Frank Møller; Jensen, N. E.

    1999-01-01

    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...... of resistance to antibiotics because strains isolated from pigs with meningitis were resistant to sulfamethazoxazole and strains isolated from pigs with pneumonia, endocarditis, pericarditis, or septicemia were resist-ant to tetracycline....

  15. Effects of local immunization with glucosyltransferase fractions from Streptococcus mutans on dental caries in hamsters caused by homologous and heterologous serotypes of Streptococcus mutans.

    Science.gov (United States)

    Smith, D J; Taubman, M A; Ebersole, J L

    1978-09-01

    Seven serotypes of Streptococcus mutans have been identified. The biochemical, genetic, and serological characteristics of these serotypes have indicated that certain serotypes are quite similar, whereas others are quite distinct. The effect of local immunization with glucosyltransferase (GTF) enzymes from serotypes a, c, or g on infection and disease caused by homologous or heterologous cariogenic S. mutans is reported. Organisms with either similar (a and g) or different (c and g) biochemical and serological characteristics were selected for heterologous challenge. NIH white hamsters were injected four times at weekly intervals with GTF prepared by 6 M guanidine-hydrochloride elution from water-insoluble glucan of serotypes a, c, or g, which resulted in enzyme (homologous) inhibitory activity in sera and salivas. After infection of GTF-immunized and sham-immunized groups of hamsters with cariogenic S. mutans of the same serotype as the injected antigen (homologous infection) or with S. mutans of a different serotype from the injected antigen (heterologous infection), the numbers of streptomycin-labeled S. mutans, caries, and lesions were determined. Immunization with GTF preparations from each of the three serotypes resulted in statistically significant reductions in the extent of infection and disease and number of lesions caused by infections with homologous cariogenic S. mutans. Statistically significant reductions in these three parameters were also observed in groups immunized with enzyme from serotype a (strain E49) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype c (strain Ingbritt) and challenged with cariogenic serotype g (strain 6715) organisms; or immunized with enzyme from serotype g (strain 6715) and challenged with cariogenic serotype c (strain Ingbritt) organisms. These studies suggest that soluble antigen preparations containing GTF from one serotype may elicit a protective immune response

  16. Dengue serotype surveillance among patients admitted for dengue in two major hospitals in Selangor, Malaysia, 2010-2011.

    Science.gov (United States)

    Ab-Fatah, M; Subenthiran, S; Abdul-Rahman, P S A; Saat, Z; Thayan, R

    2015-03-01

    Dengue serotype surveillance is important as any changes in serotype distribution may result in an outbreak or increase in severe dengue cases. This study aimed to determine circulating dengue serotypes in two hospitals in Selangor. Serum samples were collected from patients admitted for dengue at these two major public hospitals i.e. Hospital Sungai Buloh (HSB) and Hospital Tunku Ampuan Rahimah (HTAR) between November 2010 and August 2011 and subjected to real-time RT-PCR using SYBR® Green. All four dengue serotypes were detected in samples from both hospitals. The predominating serotype was dengue 1 in samples from both hospitals (HSB, DENV-1; 25.53 % and HTAR, DENV-1; 32.1 %).

  17. Mortality in Captive Rhesus Monkeys (Macaca mulatta) in China Due to Infection with Yersinia pseudotuberculosis Serotype O:1a.

    Science.gov (United States)

    Zhao, Na; Li, Meng; Amer, Said; Liu, Shelan; Luo, Jing; Wang, Shan; He, Hongxuan

    2016-09-01

    The most common serotypes of Yersinia pseudotuberculosis infecting non-human primates are serotypes O:1b, O:3, O:4, and O:7. The O:1a serotype has never been reported in non-human primates. The present study describes an outbreak of serotype O:1a with high fatality (6/18) in captive rhesus monkeys in China. Bacteria were isolated from different organs of the carcasses using standard microbiological procedures. The strain was identified using conventional and molecular techniques such as morphological and biochemical identification, serotype determination, PCR-sequence analysis based on the 16S rRNA gene, detection of virulence genes, and antimicrobial susceptibility testing. The pathogenicity was determined after experimental infection in mice. Taken together, the obtained data indicate that Y. pseudotuberculosis O:1a is a pathogen of concern and represents a potential threat to monkey conservation efforts.

  18. Application of WGS data for O-specific antigen analysis and in silico serotyping of Pseudomonas aeruginosa isolates

    DEFF Research Database (Denmark)

    Thrane, Sandra Wingaard; Taylor, Véronique L.; Lund, Ole;

    2016-01-01

    Accurate typing methods are required for efficient infection control. The emergence of whole genome sequencing (WGS) technologies has enabled the development of genomics-based methods applicable for routine typing and surveillance of bacterial pathogens. In this study, we developed the Pseudomonas...... 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....... This frequency is rarely achievable by conventional serotyping methods. The limited number of non-typeable isolates found using PAst was the result of either complete absence of OSA genes in the genomes or the artifact of genomic misassembly. With PAst, P. aeruginosa serotype data can be obtained from WGS...

  19. Pseudomonas aeruginosa rfc genes of serotypes O2 and O5 could complement O-polymerase-deficient semi-rough mutants of either serotype.

    Science.gov (United States)

    de Kievit, T R; Staples, T; Lam, J S

    1997-02-15

    Using a gene-replacement strategy and a mutated copy of the Pseudomonas aeruginosa O5 rfc gene, we were able to generate a rfc mutant in P. aeruginosa serotype O2. This mutant, which exhibits the semi-rough (SR) LPS phenotype, was used to isolate the O2 rfc gene. Mobilization of the O2 and O5 rfc genes into SR mutants of the heterologous serotype resulted in 'cross-polymerization' of O-repeat units, indicating that the genes are functionally exchangeable. Analysis of the nucleotide sequence of the rfc genes revealed that the two Rfc proteins are identical. The results of this study have enabled us to propose the linkage catalyzed by the O5 O-polymerase enzyme.

  20. Molecular epidemiology of dengue virus serotypes 2 and 3 in Paraguay during 2001-2006: the association of viral clade introductions with shifting serotype dominance.

    Science.gov (United States)

    Aquino, Jose D J Diaz; Tang, Wei-Feng; Ishii, Ryoichi; Ono, Tetsuro; Eshita, Yuki; Aono, Hiroshi; Makino, Yoshihiro

    2008-11-01

    To determine the genetic variability of dengue viruses (DENVs) in Paraguay, the complete envelope gene was sequenced for 4 DENV-2 and 22 DENV-3 strains isolated from 2001 to 2006. The sequence data were used in Bayesian phylogenetic analyses, which revealed that Paraguayan DENV-2 strains fell into two distinct clades within the American/Asian genotype, thus suggesting that the introduction of a new DENV-2 clade was likely associated with the shift of dominant serotype from DENV-3 to DENV-2 in 2005 and might have caused an outbreak of DENV-2. This study also indicated that DENV-3 strains fell into genotype III, of which, several 2006 isolates varied from the remaining isolates in their tree locations. The introduction of this new clade was likely associated with the shift of dominant serotype from DENV-2 to DENV-3 in 2006 and might have caused an epidemic of DENV-3. More data are needed to test this hypothesis.

  1. Validation and characterization of a human volunteer challenge model for cholera by using frozen bacteria of the new Vibrio cholerae epidemic serotype, O139

    NARCIS (Netherlands)

    Cohen, MB; Giannella, RA; Losonsky, GA; Lang, DR; Parker, S; Hawkins, JA; Gunther, C; Schiff, GA

    1999-01-01

    Until recently, all epidemic strains of Vibrio cholerae were of the O1 serotype. Current epidemics have also been caused by a new serotype, Vibrio cholerae O139. Although the pathogenesis and clinical features of O139 cholera are similar to those of O1 cholera, immunity to serotype O1 does not confe

  2. Simultaneous Quantification and Differentiation of Streptococcus suis Serotypes 2 and 9 by Quantitative Real-Time PCR, Evaluated in Tonsillar and Nasal Samples of Pigs

    Directory of Open Access Journals (Sweden)

    Niels Dekker

    2016-06-01

    Full Text Available Invasive Streptococcus suis (S. suis infections in pigs are often associated with serotypes 2 and 9. Mucosal sites of healthy pigs can be colonized with these serotypes, often multiple serotypes per pig. To unravel the contribution of these serotypes in pathogenesis and epidemiology, simultaneous quantification of serotypes is needed. A quantitative real-time PCR (qPCR targeting cps2J (serotypes 2 and 1/2 and cps9H (serotype 9 was evaluated with nasal and tonsillar samples from S. suis exposed pigs. qPCR specifically detected serotypes in all pig samples. The serotypes loads in pig samples estimated by qPCR showed, except for serotype 9 in tonsillar samples (correlation coefficient = 0.25, moderate to strong correlation with loads detected by culture (correlation coefficient > 0.65, and also in pigs exposed to both serotypes (correlation coefficient > 0.75. This qPCR is suitable for simultaneous differentiation and quantification of important S. suis serotypes.

  3. Validation and characterization of a human volunteer challenge model for cholera by using frozen bacteria of the new Vibrio cholerae epidemic serotype, O139

    NARCIS (Netherlands)

    Cohen, MB; Giannella, RA; Losonsky, GA; Lang, DR; Parker, S; Hawkins, JA; Gunther, C; Schiff, GA

    1999-01-01

    Until recently, all epidemic strains of Vibrio cholerae were of the O1 serotype. Current epidemics have also been caused by a new serotype, Vibrio cholerae O139. Although the pathogenesis and clinical features of O139 cholera are similar to those of O1 cholera, immunity to serotype O1 does not

  4. CRISPR is an optimal target for the design of specific PCR assays for salmonella enterica serotypes Typhi and Paratyphi A.

    Directory of Open Access Journals (Sweden)

    Laetitia Fabre

    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.

  5. The Relevance of a Novel Quantitative Assay to Detect up to 40 Major Streptococcus pneumoniae Serotypes Directly in Clinical Nasopharyngeal and Blood Specimens.

    Directory of Open Access Journals (Sweden)

    Melina Messaoudi

    Full Text Available For epidemiological and surveillance purposes, it is relevant to monitor the distribution and dynamics of Streptococcus pneumoniae serotypes. Conventional serotyping methods do not provide rapid or quantitative information on serotype loads. Quantitative serotyping may enable prediction of the invasiveness of a specific serotype compared to other serotypes carried. Here, we describe a novel, rapid multiplex real-time PCR assay for identification and quantification of the 40 most prevalent pneumococcal serotypes and the assay impacts in pneumonia specimens from emerging and developing countries. Eleven multiplex PCR to detect 40 serotypes or serogroups were optimized. Quantification was enabled by reference to standard dilutions of known bacterial load. Performance of the assay was evaluated to specifically type and quantify S. pneumoniae in nasopharyngeal and blood samples from adult and pediatric patients hospitalized with pneumonia (n = 664 from five different countries. Serogroup 6 was widely represented in nasopharyngeal specimens from all five cohorts. The most frequent serotypes in the French, South African, and Brazilian cohorts were 1 and 7A/F, 3 and 19F, and 14, respectively. When both samples were available, the serotype in blood was always present as carriage with other serotypes in the nasopharynx. Moreover, the ability of a serotype to invade the bloodstream may be linked to its nasopharyngeal load. The mean nasopharyngeal concentration of the serotypes that moved to the blood was 3 log-fold higher than the ones only found in the nasopharynx. This novel, rapid, quantitative assay may potentially predict some of the S. pneumoniae serotypes invasiveness and assessment of pneumococcal serotype distribution.

  6. Detection and transmission of extracellular fac-tor producing Streptococcus suis serotype 2 strains in pigs

    NARCIS (Netherlands)

    Swildens, B.|info:eu-repo/dai/nl/304831271

    2009-01-01

    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

  7. Genome biology of Actinobacillus pleuropneumoniae JL03, an isolate of serotype 3 prevalent in China.

    Directory of Open Access Journals (Sweden)

    Zhuofei Xu

    Full Text Available Actinobacillus pleuropneumoniae is the etiologic agent of porcine contagious pleuropneumonia, a cause of considerable world wide economic losses in the swine industry. We sequenced the complete genome of A. pleuropneumoniae, JL03, an isolate of serotype 3 prevalent in China. Its genome is a single chromosome of 2,242,062 base pairs containing 2,097 predicted protein-coding sequences, six ribosomal rRNA operons, and 63 tRNA genes. Preliminary analysis of the genomic sequence and the functions of the encoded proteins not only confirmed the present physiological and pathological knowledge but also offered new insights into the metabolic and virulence characteristics of this important pathogen. We identified a full spectrum of genes related to its characteristic chemoheterotrophic catabolism of fermentation and respiration with an incomplete TCA system for anabolism. In addition to confirming the lack of ApxI toxin, identification of a nonsense mutation in apxIVA and a 5'-proximal truncation of the flp operon deleting both its promoter and the flp1flp2tadV genes have provided convincing scenarios for the low virulence property of JL03. Comparative genomic analysis using the available sequences of other serotypes, probable strain (serotype-specific genomic islands related to capsular polysaccharides and lipopolysaccharide O-antigen biosyntheses were identified in JL03, which provides a foundation for future research into the mechanisms of serotypic diversity of A. pleuropneumoniae.

  8. Molecular serotyping and antimicrobial resistance profiles of Actinobacillus pleuropneumoniae isolated from pigs in South Korea.

    Science.gov (United States)

    Kim, Boram; Hur, Jin; Lee, Ji Yeong; Choi, Yoonyoung; Lee, John Hwa

    2016-09-01

    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.

  9. Detection of antibodies against Actinobacillus pleuropneumoniae serotype 5 using an inhibition enzyme immunoassay

    DEFF Research Database (Denmark)

    Stenbæk, Eva I.; DeLaSalle, F.; Gottschalk, M.

    1997-01-01

    An inhibition enzyme immunoassay (EIA) for detection of antibodies against A. pleuropneumoniae serotype 5 (App-5) in pig sera, based on the inhibition of the binding of an App-5 specific monoclonal antibody was established. The monoclonal antibody (MAb 210-F11) was found to be directed against...

  10. Genome Sequence of Bluetongue virus Serotype 17 Isolated in Brazil in 2014.

    Science.gov (United States)

    Matos, Ana Carolina Diniz; Rosa, Júlio César Câmara; Nomikou, Kyriaki; Guimarães, Lorena Lima Barbosa; Costa, Érica Azevedo; Guedes, Maria Isabel Maldonado Coelho; Driemeier, David; Lobato, Zélia Inês Portela; Mertens, Peter Paul Clement

    2016-10-27

    The complete genome sequence of Bluetongue virus (BTV) serotype 17 strain 17/BRA/2014/73, isolated from a sheep in Brazil in 2014, is reported here. All segments clustered with western topotype strains and indicated reassortment events with other BTV from the Americas. The strain 17/BRA/2014/73 represents a novel reference strain for BTV-17 from South America.

  11. Financial consequences of the Dutch bluetongue serotype 8 epidemics of 2006 and 2007

    NARCIS (Netherlands)

    Velthuis, A.G.J.; Saatkamp, H.W.; Mourits, M.C.M.; Koeijer, de A.A.; Elbers, A.R.W.

    2010-01-01

    This study calculates the financial consequences of the bluetongue serotype 8 (BTV8) epidemics of 2006 and 2007 in the Netherlands. We constructed a deterministic economic model that is compatible with the Dutch livestock production systems for cattle, sheep and goats. Two hundred cattle farms and 2

  12. Genomic epidemiology of Salmonella enterica serotype Enteritidis based on population structure of prevalent lineages

    Science.gov (United States)

    Salmonella enterica serotype Enteritidis (SE) is one of the most commonly reported causes of human salmonellosis. The low genetic diversity of SE measured by fingerprinting methods has made subtyping a challenge. In this study, we used whole genome sequencing to characterize a total of 125 SE and Sa...

  13. Adeno-associated viral vector serotype 5 poorly transduces liver in rat models.

    Directory of Open Access Journals (Sweden)

    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.

  14. Identification of Avian Paramyxovirus Serotype-1 in Wild Birds in the USA

    Science.gov (United States)

    In the US, sampling for avian paramyxovirus serotype-1 (APMV-1) is generally conducted when morbidity or mortality events occur involving certain families of wild birds known to be affected by the virus, such as cormorants (Family Phalacrocoracidae), pigeons, doves (Family Columbidae), or pelicans (...

  15. Limited evidence of intercontinental dispersal of avian paramyxovirus serotype 4 by migratory birds

    Science.gov (United States)

    Avian paramyxovirus serotype 4 (APMV-4) is a single stranded RNA virus that has most often been isolated from waterfowl. Limited information has been reported regarding the prevalence, pathogenicity, and genetic diversity of AMPV-4. To assess the intercontinental dispersal of this viral agent, we se...

  16. Genotypic and serotypic stability of Campylobacter jejuni strains during in vitro and in vivo passage

    DEFF Research Database (Denmark)

    Nielsen, Eva M.; Engberg, J.; Fussing, V.

    2001-01-01

    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...

  17. Serotype and genotype diversity and hatchery transmission of Campylobacter jejuni in commercial poultry flocks

    DEFF Research Database (Denmark)

    Petersen, L.; Nielsen, E.M.; On, Stephen L.W.

    2001-01-01

    We investigated the genotype and serotype diversity of Campylobacter coli and C jejuni in two parent flocks of adult hens and their offspring over two rotations in order to evaluate the role of hatchery mediated transmission and/or vertical transmission of campylobacters in broiler flocks. In tot...

  18. Differential induction of total IgE by two Salmonella enterica serotypes

    DEFF Research Database (Denmark)

    Ktsoyan, Zhanna A.; Mkrtchyan, Mkhitar S.; Zakharyan, Magdalina K.;

    2015-01-01

    The main goal of this study was to establish how the inflammation caused by infection with two different Salmonella enterica serotypes, S. Typhimurium and S. Enteritidis, may lead to the predisposition to allergy as measured by total IgE level in the blood. Infection by S. Typhimurium did not aff...

  19. Luminex(®) multiplex bead suspension arrays for the detection and serotyping of Salmonella spp.

    Science.gov (United States)

    Dunbar, Sherry A; Ritchie, Vivette Brown; Hoffmeyer, Michaela R; Rana, Gunjot S; Zhang, Hongwei

    2015-01-01

    In this chapter we describe two commercially available bead-based molecular assays for detection, identification and serotyping of Salmonella. The xTAG(®) Gastrointestinal Pathogen Panel (GPP) is a qualitative multiplex test for the simultaneous detection of nucleic acids from Salmonella plus 14 other gastroenteritis-causing bacteria, viruses, and parasites from stool specimens. xTAG GPP uses the Luminex(®) xTAG universal array technology for the identification of specific target sequences combined with the xMAP(®) bead multiplexing platform for detection of the targets that were present in the starting sample. The xMAP Salmonella Serotyping Assay (SSA) is a multiplex nucleic acid-based direct hybridization assay for molecular identification of the serotype of Salmonella isolates. In xMAP SSA, target sequences amplified from cultured Salmonella isolates are captured by hybridization to sequence-specific capture probes which have been coupled to the multiplexed bead sets. Herein we provide detailed protocols for each of these assays and present data which describe their performance characteristics for detection and serotyping Salmonella.

  20. Co-circulation and co-infections of all dengue virus serotypes in Hyderabad, India 2014.

    Science.gov (United States)

    Vaddadi, K; Gandikota, C; Jain, P K; Prasad, V S V; Venkataramana, M

    2017-09-01

    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.

  1. Classification of Salmonella Enterica serotypes with selective bands using visible/NIR hyperspectral imaging

    Science.gov (United States)

    Optical detection of foodborne bacteria such as Salmonella classifies bacteria by analyzing spectral data, and has potential for rapid detection. In this experiment hyperspectral microscopy is explored as a means for classifying five Salmonella serotypes. Initially, the microscope collects 89 spect...

  2. Correlation of disease spectrum among four Dengue serotypes: a five years hospital based study from India.

    Science.gov (United States)

    Kumaria, Rajni

    2010-01-01

    The recognition of DF (DHF Dengue Hemorrhagic Fever) is very complicated due to occurrence of a wide spectrum of clinical signs and symptoms during acute phase of illness. Moreover, presence of four serotypes further complicates the prognosis. To investigate the predictors of disease severity and elucidate the prognostic markers among four dengue serotypes, this study was conducted on 320 inpatients having acute febrile illness clinically suspected as DI, over a period of five years. Dengue serotypes were confirmed by multiplex reverse transcriptase (RT)-PCR. Eighty patients were positive for DI with presence of Den-1, Den-2, Den-3, and Den-4 in 8, 35, 27 and 10 patients, respectively. The severe clinical manifestations, abdominal pain and hepatomegaly, were comparatively higher in Den-2 patients. Liver aminotransferases levels were also higher in Den-2 patients (app. 5 fold). This study clearly indicates the hyperendemicity of all dengue serotypes. Nucleotide sequencing of Envelope region revealed that the presently emerged Den-3 belongs to type III, having high homology with genotype responsible for number of outbreaks in 1980s. The re-emergence of this deadly type can be suspected to cause more outbreaks in future and is a matter of great concern.

  3. Tetravalent neutralizing antibody response against four dengue serotypes by a single chimeric dengue envelope antigen.

    Science.gov (United States)

    Apt, Doris; Raviprakash, Kanakatte; Brinkman, Alice; Semyonov, Andrey; Yang, Shumin; Skinner, Craig; Diehl, Lori; Lyons, Richard; Porter, Kevin; Punnonen, Juha

    2006-01-16

    We employed DNA shuffling and screening technologies to develop a single recombinant dengue envelope (E) antigen capable of inducing neutralizing antibodies against all four antigenically distinct dengue serotypes. By DNA shuffling of codon-optimized dengue 1-4 E genes, we created a panel of novel chimeric clones expressing C-terminal truncated E antigens that combined epitopes from all four dengue serotypes. DNA vaccines encoding these novel chimeras induced multivalent T cell and neutralizing antibody responses against all four dengue serotypes in mice. By contrast, a mixture of four unshuffled, parental DNA vaccines failed to produce tetravalent neutralizing antibodies in mice. The neutralizing antibody titers for some of these antigens could be further improved by extending the sequences to express full-length pre-membrane and envelope proteins. The chimeric antigens also protected mice against a lethal dengue-2 virus challenge. These data demonstrate that DNA shuffling and associated screening can lead to the selection of multi-epitope antigens against closely related dengue virus serotypes and suggest a broad utility for these technologies in optimizing vaccine antigens.

  4. Simplifying complex sequence information: a PCP-consensus protein binds antibodies against all four Dengue serotypes.

    Science.gov (United States)

    Bowen, David M; Lewis, Jessica A; Lu, Wenzhe; Schein, Catherine H

    2012-09-14

    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.

  5. Correlation of disease spectrum among four Dengue serotypes: a five years hospital based study from India

    Directory of Open Access Journals (Sweden)

    Rajni Kumaria

    2010-04-01

    Full Text Available The recognition of DF (DHF Dengue Hemorrhagic Fever is very complicated due to occurrence of a wide spectrum of clinical signs and symptoms during acute phase of illness. Moreover, presence of four serotypes further complicates the prognosis. To investigate the predictors of disease severity and elucidate the prognostic markers among four dengue serotypes, this study was conducted on 320 inpatients having acute febrile illness clinically suspected as DI, over a period of five years. Dengue serotypes were confirmed by multiplex reverse transcriptase (RT-PCR. Eighty patients were positive for DI with presence of Den-1, Den-2, Den-3, and Den-4 in 8, 35, 27 and 10 patients, respectively. The severe clinical manifestations, abdominal pain and hepatomegaly, were comparatively higher in Den-2 patients. Liver aminotransferases levels were also higher in Den-2 patients (app. 5 fold. This study clearly indicates the hyperendemicity of all dengue serotypes. Nucleotide sequencing of Envelope region revealed that the presently emerged Den-3 belongs to type III, having high homology with genotype responsible for number of outbreaks in 1980s. The re-emergence of this deadly type can be suspected to cause more outbreaks in future and is a matter of great concern.

  6. Serotypes and typability of Campylobacter jejuni and Campylobacter coli isolated from poultry products

    DEFF Research Database (Denmark)

    Nielsen, Eva Møller; Nielsen, Niels Ladefoged

    1999-01-01

    Campylobacter infection is one of the most common bacterial enteric pathogens. Campylobacter jejuni and Campylobacter coli infections are mostly food- and waterborne and especially poultry is often assumed to be an important source. The heat-stable serotyping system (the 'Penner' scheme) was used...

  7. Genomic sequence of Campylobacter jejuni subsp. jejuni HS:19 Penner serotype reference strain RM3420

    NARCIS (Netherlands)

    C.T. Parker (Craig); Huynh, S. (Steven); A.P. Heikema (Astrid)

    2017-01-01

    textabstractCampylobacter jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of C.

  8. Complete Genome Sequence of the Serotype k Streptococcus mutans Strain LJ23

    Science.gov (United States)

    Aikawa, Chihiro; Furukawa, Nayuta; Watanabe, Takayasu; Minegishi, Kana; Furukawa, Asuka; Eishi, Yoshinobu; Oshima, Kenshiro; Kurokawa, Ken; Hattori, Masahira; Nakano, Kazuhiko; Nakagawa, Ichiro; Ooshima, Takashi

    2012-01-01

    Streptococcus mutans is the major pathogen of dental caries and occasionally causes infective endocarditis. Here we report the complete genome sequence of serotype k S. mutans strain LJ23, which was recently isolated from the oral cavity of a Japanese patient. PMID:22535936

  9. Outbreak-associated Salmonella enterica Serotypes and Food Commodities, United States, 1998- 2008

    Centers for Disease Control (CDC) Podcasts

    2013-09-09

    Dr. Mike Miller reads an abridged version of the Emerging Infectious Diseases’ 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.

  10. Prevalence, serotype, virulence characteristics, clonality and antibiotic susceptibility of pathogenic Yersinia enterocolitica from swine feces

    Science.gov (United States)

    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...

  11. Zebrafish (Danio rerio) bioassay for visceral toxicosis of catfish and botulinum neurotoxin serotype E

    Science.gov (United States)

    Visceral toxicosis of catfish (VTC), a sporadic disease of cultured channel catfish (Ictalurus punctatus) often with high mortality, is caused by botulinum neurotoxin serotype E (BoNT/E). Presumptive diagnosis of VTC is based on characteristic clinical signs and lesions, and the production of these ...

  12. A Descriptive Study of Human Salmonella Serotype Typhimurium Infections Reported in Ontario from 1990 to 1997

    Directory of Open Access Journals (Sweden)

    Michael W Ford

    2003-01-01

    Full Text Available BACKGROUND: Salmonella infections cause gastrointestinal and systemic diseases worldwide and are the leading causes of food-borne illnesses in North America (1-4. Salmonella serotype typhimurium (ST, in particular, is increasingly becoming a major public health concern because of its ability to acquire multiple resistant genes (5,6.

  13. An evaluation of serotyping of Avibacterium paragallinarum by use of a multiplex polymerase chain reaction.

    Science.gov (United States)

    Morales-Erasto, Vladimir; Posadas-Quintana, José de Jesús; Fernández-Díaz, Manolo; Saravia, Luis E; Martínez-Castañeda, José Simón; Blackall, Patrick J; Soriano-Vargas, Edgardo

    2014-03-01

    In the present study, the ability of a recently proposed multiplex polymerase chain reaction (mPCR) to determine the serogroups (A, B, and C) of Avibacterium paragallinarum was evaluated. A total of 12 reference strains and 69 field isolates of Av. paragallinarum from Ecuador, Mexico, Panama, and Peru were included in the study. With some exceptions (which were serotyped in the current study), all of the isolates and strains had been previously examined by 2 serotyping schemes (Page and Kume) or were the formal reference strains for the schemes. Three of 6 (50%) reference strains of serogroup A, 2 (100%) of serogroup B, and 1 of 4 (25%) reference strains of serogroup C were correctly serotyped by the mPCR. With the field isolates, the mPCR correctly recognized 16 of the 17 serogroup A isolates, 10 of the 12 serogroup B isolates, and 18 of the 37 serogroup C isolates. Overall, the specificity and sensitivity of the PCR test was as follows: 82.6% and 87.3% (serogroup A), 85.7% and 71.9% (serogroup B), and 46.3% and 100% (serogroup C). The poor performance of the mPCR in terms of recognition of serogroup C isolates (low sensitivity of 46.3%) and the relatively high level of uncertainty about the accuracy of the serogroup A and B results (specificity of 87.3% and 71.9%, respectively) means that the assay cannot be recommended as a replacement for conventional serotyping.

  14. Genomic Sequence of Campylobacter jejuni subsp. jejuni HS:19 Penner Serotype Reference Strain RM3420

    Science.gov (United States)

    Huynh, Steven; Heikema, Astrid P.

    2017-01-01

    ABSTRACT Campylobacter jejuni subsp. jejuni infections are a leading cause of foodborne gastroenteritis and the most prevalent antecedent to Guillain-Barré syndrome (GBS). Penner serotype HS:19 is among several capsular types shown to be markers for GBS. This study describes the genome of C. jejuni subsp. jejuni HS:19 Penner reference strain RM3420. PMID:28232429

  15. Experimental vaccination of pigs with an Actinobacillus pleuropneumoniae serotype 5b capsular polysaccharide tetanus toxoid conjugate

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Jacobsen, M.J.; Nielsen, J.P.

    1997-01-01

    The protective efficacy of an Actinobacillus pleuropneumoniae serotype 5b capsular polysaccharide-tetanus toroid conjugate (Ap5bCP-TT) against homologous challenge of pigs was investigated. Four pigs were non-vaccinated controls (group A), 4 pigs were injected with adjuvant without antigen (group B...

  16. Streptococcus agalactiae Serotype Distribution and Antimicrobial Susceptibility in Pregnant Women in Gabon, Central Africa

    OpenAIRE

    Sabine Belard; Nicole Toepfner; Mesküre Capan-Melser; Ghyslain Mombo-Ngoma; Rella Zoleko-Manego; Mirjam Groger; Pierre-Blaise Matsiegui; Agnandji, Selidji T.; Adegnika, Ayôla A; Raquel González; Kremsner, Peter G.; Clara Menendez; Michael Ramharter; Reinhard Berner

    2015-01-01

    Neonatal invasive disease due to Streptococcus agalactiae is life threatening and preventive strategies suitable for resource limited settings are urgently needed. Protective coverage of vaccine candidates based on capsular epitopes will relate to local epidemiology of S. agalactiae serotypes and successful management of critical infections depends on timely therapy with effective...

  17. Modelling local dispersal of Bluetongue virus serotype 8 using random walk.

    NARCIS (Netherlands)

    Gerbier, G.; Baldet, T.; Tran, A.; Hendrickx, G.; Guis, H.; Mintiens, K.; Elbers, A.R.W.; Staubach, C.

    2008-01-01

    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

  18. Foot-and-mouth disease virus serotype SAT 3 in long-horned Ankole calf, Uganda.

    Science.gov (United States)

    Dhikusooka, Moses Tefula; Tjørnehøj, Kirsten; Ayebazibwe, Chrisostom; Namatovu, Alice; Ruhweza, Simon; Siegismund, Hans Redlef; Wekesa, Sabenzia Nabalayo; Normann, Preben; Belsham, Graham J

    2015-01-01

    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 relatives isolated previously from buffalo in Uganda.

  19. Effect of neutralizing sera on factor X-mediated adenovirus serotype 5 gene transfer

    NARCIS (Netherlands)

    Parker, A.L.; Waddington, S.N.; Buckley, S.M.K.; Custers, J.; Havenga, M.J.E.; Rooijen, N. van; Goudsmit, J.; McVey, J.H.; Nicklin, S.A.; Baker, A.H.

    2009-01-01

    The deployment of adenovirus serotype 5 (Ad5)-based vectors is hampered by preexisting immunity. When such vectors are delivered intravenously, hepatocyte transduction is mediated by the hexon-coagulation factor X (FX) interaction. Here, we demonstrate that human sera efficiently block FX-mediated

  20. Genomic Epidemiology of Salmonella enterica Serotype Enteritidis based on Population Structure of Prevalent Lineages

    DEFF Research Database (Denmark)

    Deng, Xiangyu; Desai, Prerak T.; den Bakker, Henk C.

    2014-01-01

    Salmonella enterica serotype Enteritidis is one of the most commonly reported causes of human salmonellosis. Its low genetic diversity, measured by fingerprinting methods, has made subtyping a challenge. We used whole-genome sequencing to characterize 125 S. enterica Enteritidis and 3 S. enterica...

  1. Detection and transmission of extracellular fac-tor producing Streptococcus suis serotype 2 strains in pigs

    NARCIS (Netherlands)

    Swildens, B.

    2009-01-01

    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 seroty

  2. Salmonella enterica serotype enteritidis in French Polynesia, South Pacific, 2008-2013.

    Science.gov (United States)

    Le Hello, Simon; Maillard, Fiona; Mallet, Henri-Pierre; Daudens, Elise; Levy, Marc; Roy, Valérie; Branaa, Philippe; Bertrand, Sophie; Fabre, Laetitia; Weill, François-Xavier

    2015-06-01

    Outbreaks of Salmonella enterica serotype Enteritidis infections associated with eggs occurred in French Polynesia during 2008-2013. Molecular analysis of isolates by using clustered regularly interspaced short palindromic repeat polymorphisms and multilocus variable-number tandem-repeat analysis was performed. This subtyping made defining the epidemic strain, finding the source, and decontaminating affected poultry flocks possible.

  3. Intestinal obstruction complicating Yersinia enterocolitica serotype O:21 infection in an infant.

    Science.gov (United States)

    Mufti, Areej; Al Kaabi, Nawal A; Rubin, Steven Z; Suh, Kathryn N

    2005-12-01

    Intestinal obstruction is an uncommon complication of Yersinia enterocolitica infection. We report a case of enterocolitis in an 11-month-old infant, complicated by intestinal obstruction. Y. entercolitica serotype O:21, previously reported to cause severe disease, was isolated from the patient's stool. Unusual or complicated presentations of yersiniosis may be associated with more pathogenic strains of Y. enterocolitica.

  4. Serotyping of Toxoplasma gondii in Cats (Felis domesticus) Reveals Predominance of Type II Infections in Germany

    Science.gov (United States)

    Background: Cats are definitive hosts of Toxoplasma gondii and play an essential role in the epidemiology of this parasite. The study aims at clarifying whether cats are able to develop specific antibodies against different clonal types of T. gondii and to determine by serotyping the T. gondii clona...

  5. Regulatory gene mutation: a driving force behind group a Streptococcus strain- and serotype-specific variation.

    Science.gov (United States)

    Sarkar, Poulomee; Sumby, Paul

    2017-02-01

    Data from multiple bacterial pathogens are consistent with regulator-encoding genes having higher mutation frequencies than the genome average. Such mutations drive both strain- and type- (e.g., serotype, haplotype) specific phenotypic heterogeneity, and may challenge public health due to the potential of variants to circumvent established treatment and/or preventative regimes. Here, using the human bacterial pathogen the group A Streptococcus (GAS; S. pyogenes) as a model organism, we review the types and regulatory-, phenotypic-, and disease-specific consequences of naturally occurring regulatory gene mutations. Strain-specific regulator mutations that will be discussed include examples that transform isolates into hyper-invasive forms by enhancing expression of immunomodulatory virulence factors, and examples that promote asymptomatic carriage of the organism. The discussion of serotype-specific regulator mutations focuses on serotype M3 GAS isolates, and how the identified rewiring of regulatory networks in this serotype may be contributing to a decades old epidemiological association of M3 isolates with particularly severe invasive infections. We conclude that mutation plays an outsized role in GAS pathogenesis and has clinical relevance. Given the phenotypic variability associated with regulatory gene mutations, the rapid examination of these genes in infecting isolates may inform with respect to potential patient complications and treatment options.

  6. Rapid and early detection of salmonella serotypes with hyperspectral microscope and multivariate data analysis

    Science.gov (United States)

    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...

  7. Foot-and-Mouth Disease Virus Serotype SAT 3 in Long-Horned Ankole Calf, Uganda

    DEFF Research Database (Denmark)

    Dhikusooka, Moses Tefula; Tjørnehøj, Kirsten; Ayebazibwe, Chrisostom;

    2015-01-01

    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 closes...

  8. Adeno-associated Virus (AAV) Serotypes Have Distinctive Interactions with Domains of the Cellular AAV Receptor

    Science.gov (United States)

    Pillay, Sirika; Zou, Wei; Cheng, Fang; Puschnik, Andreas S.; Meyer, Nancy L.; Ganaie, Safder S.; Deng, Xuefeng; Wosen, Jonathan E.; Davulcu, Omar; Yan, Ziying; Engelhardt, John F.; Brown, Kevin E.; Chapman, Michael S.

    2017-01-01

    ABSTRACT Adeno-associated virus (AAV) entry is determined by its interactions with specific surface glycans and a proteinaceous receptor(s). Adeno-associated virus receptor (AAVR) (also named KIAA0319L) is an essential cellular receptor required for the transduction of vectors derived from multiple AAV serotypes, including the evolutionarily distant serotypes AAV2 and AAV5. Here, we further biochemically characterize the AAV-AAVR interaction and define the domains within the ectodomain of AAVR that facilitate this interaction. By using a virus overlay assay, it was previously shown that the major AAV2 binding protein in membrane preparations of human cells corresponds to a glycoprotein with a molecular mass of 150 kDa. By establishing a purification procedure, performing further protein separation by two-dimensional electrophoresis, and utilizing mass spectrometry, we now show that this glycoprotein is identical to AAVR. While we find that AAVR is an N-linked glycosylated protein, this glycosylation is not a strict requirement for AAV2 binding or functional transduction. Using a combination of genetic complementation with deletion constructs and virus overlay assays with individual domains, we find that AAV2 functionally interacts predominantly with the second Ig-like polycystic kidney disease (PKD) repeat domain (PKD2) present in the ectodomain of AAVR. In contrast, AAV5 interacts primarily through the first, most membrane-distal, PKD domain (PKD1) of AAVR to promote transduction. Furthermore, other AAV serotypes, including AAV1 and -8, require a combination of PKD1 and PKD2 for optimal transduction. These results suggest that despite their shared dependence on AAVR as a critical entry receptor, different AAV serotypes have evolved distinctive interactions with the same receptor. IMPORTANCE Over the past decade, AAV vectors have emerged as leading gene delivery tools for therapeutic applications and biomedical research. However, fundamental aspects of the AAV life

  9. Dengue serotypes 1–4 exhibit unique host specificity in vitro

    Directory of Open Access Journals (Sweden)

    Barr KL

    2012-10-01

    Full Text Available Kelli L Barr, Benjamin D Anderson, Gary L Heil, John A Friary, Gregory C Gray, Dana A FocksDepartment of Environmental and Global Health, College of Public Health and Health Professions and the Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USABackground: Over 3000 cell lines from over 150 species are commercially available today from the American Type Culture Collection. These cell lines offer alternative approaches to investigating the interactions between arboviruses and other vertebrates at the cellular level. The various cell origins, types, and morphologies can be valuable resources for studying viral ecology and examining hypotheses regarding viral reservoirs. Dengue viruses (DENV are major re-emerging pathogens that have been studied classically in only a few cell lines.Methods: We evaluated the susceptibility of 19 distinct mammalian, avian, and reptilian cell lines to DENV infection. Cell lines were infected with DENV serotypes 1–4 and evaluated for susceptibility via focus-forming unit assays and quantitative reverse-transcription polymerase chain reaction.Results: Both methods demonstrated the ability of DENV to replicate in 14 cell lines derived from various vertebrates with viral titers ranging from 1 × 103 to 1 × 107 infectious units per milliliter. Cell line susceptibility to DENV infection was serotype specific, with DENV-1 and DENV-4 infecting more cell lines than either DENV-2 or DENV-3. Cellular type also seemed to affect the infectivity of DENV. Human endothelial cells were only susceptible to DENV-4. Of six fibroblast lines, 100% were susceptible to at least one DENV serotype whereas only 62% of 13 epithelial lines were susceptible to DENV serotypes 1–4.Conclusion: These data indicate that a variety of cell lines from human and animal species can be used to culture DENV. The serotype-specific susceptibility for certain cell lines may provide a tool to help characterize specific DENV

  10. Biofilm-Forming Abilities of Listeria monocytogenes Serotypes Isolated from Different Sources.

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    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.

  11. Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing invasive pneumococcal disease from 2009-2012 with an emphasis on serotype 19A in bacteraemic pneumonia and empyema and β-lactam resistance.

    Science.gov (United States)

    Lee, Meng-Rui; Chen, Chung-Ming; Chuang, Tzu-Yi; Huang, Yu-Tsung; Hsueh, Po-Ren

    2013-11-01

    Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae isolates that cause invasive pneumococcal disease (IPD) were studied and the role of serotype 19A in the development of bacteraemic pneumonia and empyema was investigated. Subjects comprised 98 patients (56 adults and 42 children) who were treated for IPD at a university-affiliated tertiary referral centre in Taiwan during 2009-2012. Serotypes of the isolates were identified using the latex agglutination method. In vitro susceptibilities of the isolates to 13 antimicrobial agents were determined using the broth microdilution method and were interpreted as recommended by the Clinical and Laboratory Standards Institute. During the study period, bacteraemic pneumonia was the most common type of infection (43/98; 43.9%), followed by primary bacteraemia (30/98; 30.6%). Serotype 19A was the most common serotype (23/98; 23.5%) in all patients. Fourteen (70.0%) of 20 children (47.6% of all children) with serotype 19A infection had pneumonia with empyema, whilst eight patients had concomitant bacteraemia. 7-valent pneumococcal conjugated vaccine (PCV-7), PCV-10, PCV-13 and 23-valent pneumococcal polysaccharide vaccine (PPV-23) had coverage rates of 37.8%, 38.8%, 79.6% and 77.6%, respectively. A substantial increase in the proportion of serotype 15A (6.1%) and 6A (8.2%) was found. In addition, there was a significant reduction in rates of susceptibility of serotype 19A isolates to penicillin, cefotaxime and ceftriaxone but not to azithromycin or any quinolone tested compared with those of non-19A isolates. The prevalence of serotypes 19A, 15A and 6A in patients with IPD increased markedly during the period, especially in children with bacteraemic pneumonia and empyema.

  12. DHF cases dominated by Den-3 serotype in the West Java province

    Directory of Open Access Journals (Sweden)

    Prasetyowati Prasetyowati

    2012-09-01

    Indonesia, data on the distribution of serotypes in the province is still very limited to specifi c areas within different time periods. In 2000 – 2002, the serotype Den-2 dominated the Bandung city area. The purpose of this study was to identify the distribution of dengue virus serotype in the West Java province and the dominant serotypes in DHF cases.Methods: Data was collected in October-December 2008 from 27 hospitals in the West Java province. The population for this study was all patients diagnosed with dengue virus hospitalized in the 27 hospitals. Sample was purposively chosen from these patients who were willing to participate in further immunologic examinations. Serum from patients who were immunologically positive was further examined to determine thedengue virus serotype. This examination was done in the Biomedical and Basic Health Technology Center of the Health Research and Development Unit Republic of Indonesia using the nested RT-PCR method.Results: Out 513 samples examined, 180 samples could be identifi ed. Dengue virus was not found in the rest of the samples. Four samples showed multiple infections of 2 dengue virus serotypes. All four serotypes were found in the West Java province. In all positive samples, Den-3 was found to be the dominant serotype with 47.8%, followed by Den-2 (26.0%, Den-1 (18.6%, Den-4 (5.4%, and mixed (2.2%. Den-3 was found in all endemic areas of the West Java province.Conclusion: All 4 dengue virus serotypes can be found in the West Java province with Den-3 serotype the most dominant. (Health Science Indones 2012;1:23-6 

  13. Carriage rate and serotypes of Streptococcus pneumoniae amongst children in Thika Hospital, Kenya

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    Susan Githii

    2013-03-01

    Full Text Available Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Rates of carriage are highest in infants and the elderly. The objectives of this study were to determine the rate of nasopharyngeal colonization by S. pneumoniae, and to describe the antibiotic resistant patterns and the serotypes of the carried isolates. A cross-sectional study design was used. Nasopharyngeal swabs were collected from 315 children in the months of Octoberand November 2010 and processed to isolate S. pneumoniae. The isolates were serotyped by the Quellung reaction and their antibiotic susceptibilities assessed by the disc diffusion method. The overall nasopharyngeal carriage rate for S. pneumoniae was 17%. Seventeen serotypes were detected amongst 55 strains analysed: 6A, 23F, 19F, 13, 6B, 14A, 20, 7C, 1,15B, 35B, 19A, 11A, 34, 5, 3 and 23A. Susceptibility testing revealed that nearly all (98% were resistant to cotrimoxazole, 9% were resistant to penicillin and 7% to cefotaxime. Resistance to chloramphenicol and erythromycin was 2% and 4%, respectively. All isolates were fully sensitive to tetracycline. High levels of cotrimoxazole resistance and some resistance to other antimicrobial agents commonly used in Thika District Hospital shows that there is need to revise antimicrobial policy in this region in the treatment of invasive pneumococcal infections. The frequent serotypes found in this study have previously been associated with pneumococcal infectionsin children. Several of these serotypes are included in the ten-valent vaccine and therefore useof this vaccine will help reduce pneumococcal infections in Thika.

  14. Experimental infection of hamsters with avian paramyxovirus serotypes 1 to 9

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    Samuel Arthur S

    2011-02-01

    Full Text Available Abstract Avian paramyxoviruses (APMVs are frequently isolated from domestic and wild birds throughout the world and are separated into nine serotypes (APMV-1 to -9. Only in the case of APMV-1, the infection of non-avian species has been investigated. The APMVs presently are being considered as human vaccine vectors. In this study, we evaluated the replication and pathogenicity of all nine APMV serotypes in hamsters. The hamsters were inoculated intranasally with each virus and monitored for clinical disease, pathology, histopathology, virus replication, and seroconversion. On the basis of one or more of these criteria, each of the APMV serotypes was found to replicate in hamsters. The APMVs produced mild or inapparent clinical signs in hamsters except for APMV-9, which produced moderate disease. Gross lesions were observed over the pulmonary surface of hamsters infected with APMV-2 & -3, which showed petechial and ecchymotic hemorrhages, respectively. Replication of all of the APMVs except APMV-5 was confirmed in the nasal turbinates and lungs, indicating a tropism for the respiratory tract. Histologically, the infection resulted in lung lesions consistent with bronchointerstitial pneumonia of varying severity and nasal turbinates with blunting or loss of cilia of the epithelium lining the nasal septa. The majority of APMV-infected hamsters exhibited transient histological lesions that self resolved by 14 days post infection (dpi. All of the hamsters infected with the APMVs produced serotype-specific HI or neutralizing antibodies, confirming virus replication. Taken together, these results demonstrate that all nine known APMV serotypes are capable of replicating in hamsters with minimal disease and pathology.

  15. Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

    Science.gov (United States)

    Fitzgerald, R J; Adams, B O; Sandham, H J; Abhyankar, S

    1989-03-01

    A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

  16. Classification of Salmonella enterica serotypes with selective bands using visible/NIR hyperspectral microscope images.

    Science.gov (United States)

    Eady, M; Park, B

    2016-07-01

    Optical detection of foodborne bacteria such as Salmonella classifies bacteria by analysing spectral data, and has potential for rapid detection. In this experiment hyperspectral microscopy is explored as a means for classifying five Salmonella serotypes. Initially, the microscope collects 89 spectral measurements between 450 and 800 nm. Here, the objective was to develop correct classification of five serotypes with optimal spectral bands selected through multivariate data analysis (MVDA), thus reducing the data processing and storage requirement necessary for practical application in the food industry. An upright digital microscope is equipped with an acousto-optical tuneable filter, electron multiplying charge-coupled device, and metal halide lighting source. Images for each of the five serotypes were collected, and informative bands were identified through a principal component analysis, for four abbreviated spectral ranges containing 3, 7, 12 and 20 spectral bands. The experiment was repeated with an independent repetition and images were collected at each of the reduced band sets, identified by the first repetition. A support vector machine (SVM) was used to classify serotypes. Results showed that with the first repetition, classification accuracy decreased from 99.5% (89 bands) to 84.5% (3 bands), whereas the second repetition showed classification accuracies of 100%, possibly due to a reduction in spectral noise. The support vector machine regression (SVMR) was applied with cross-validation, and had R(2) calibration and validation values >0.922. Although classification accuracies through SVM classification showed that as little as 3 bands were able to classify 100% of the samples, the SVMR shows that the smallest root-mean squared-error values were 0.001 and 0.002 for 20 and 12 bands, respectively, suggesting that the 12 band range collected between 586 and 630 nm is optimal for classifying bacterial serotypes, with only the informative HMI bands selected.

  17. Replication, neurotropism, and pathogenicity of avian paramyxovirus serotypes 1-9 in chickens and ducks.

    Directory of Open Access Journals (Sweden)

    Shin-Hee Kim

    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.

  18. Clustering of serotypes in a longitudinal study of Streptococcus pneumoniae carriage in three day care centres

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    Tanskanen Antti

    2008-12-01

    Full Text Available Abstract Background Streptococcus pneumoniae (pneumococcus causes a wide range of clinical manifestations that together constitute a major burden of disease worldwide. The main route of pneumococcal transmission is through asymptomatic colonisation of the nasopharynx. Studies of transmission are currently of general interest because of the impact of the new conjugate-polysaccharide vaccines on nasopharyngeal colonisation (carriage. Here we report the first longitudinal study of pneumococcal carriage that records serotype specific exposure to pneumococci simultaneously within the two most important mixing groups, families and day care facilities. Methods We followed attendees (N = 59 with their family members (N = 117 and the employees (N = 37 in three Finnish day care centres for 9 months with monthly sampling of nasopharyngeal carriage. Pneumococci were cultured, identified and serotyped by standard methods. Results Children in day care constitute a core group of pneumococcal carriage: of the 36 acquisitions of carriage with documented exposure to homologous pneumococci, the attendee had been exposed in her/his day care centre in 35 cases and in the family in 9 cases. Day care children introduce pneumococci to the family: 66% of acquisitions of a new serotype in a family were associated with simultaneous or previous carriage of the same type in the child attending day care. Consequently, pneumococcal transmission was found to take place as micro-epidemics driven by the day care centres. Each of the three day care centres was dominated by a serotype of its own, accounting for 100% of the isolates of that serotype among all samples from the day care attendees. Conclusion The transmission of pneumococci is more intense within than across clusters defined by day care facilities. The ensuing micro-epidemic behaviour enhances pneumococcal transmission.

  19. Reappraisal of the taxonomy of Streptococcus suis serotypes 20, 22 and 26: Streptococcus parasuis sp. nov.

    Science.gov (United States)

    Nomoto, R; Maruyama, F; Ishida, S; Tohya, M; Sekizaki, T; Osawa, Ro

    2015-02-01

    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.

  20. Concurrent infections by all four dengue virus serotypes during an outbreak of dengue in 2006 in Delhi, India

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    Guleria Randeep

    2008-01-01

    Full Text Available Abstract Background Co-circulation of multiple dengue virus serotypes has been reported from many parts of the world including India, however concurrent infection with more than one serotype of dengue viruses in the same individual is rarely documented. An outbreak of dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS occurred in and around Delhi in 2006. This is the first report from India with high percentage of concurrent infections with different dengue virus serotypes circulating during one outbreak. Results Acute phase sera from patients were tested for the presence of dengue virus RNA by RT-PCR assay. Of the 69 samples tested for dengue virus RNA, 48 (69.5% were found to be positive. All the four dengue virus serotypes were found to be co-circulating in this outbreak with DENV-3 being the predominant serotype. In addition in 9 of 48 (19% dengue virus positive samples, concurrent infection with more than one dengue virus serotype were identified. Conclusion This is the first report in which concurrent infections with different dengue virus serotypes is being reported during an outbreak from India. Delhi is now truly hyperendemic for dengue.

  1. Incidence and duration of group B Streptococcus by serotype among male and female college students living in a single dormitory.

    Science.gov (United States)

    Foxman, Betsy; Gillespie, Brenda; Manning, Shannon D; Howard, Laura J; Tallman, Patricia; Zhang, Lixin; Marrs, Carl F

    2006-03-15

    Group B Streptococcus causes a variety of morbid and sometimes fatal conditions affecting individuals of all age groups. There are nine known serotypes of this Gram-positive coccus but few estimates of the incidence and duration of its colonization and none by serotype in the literature. In 2001, the authors conducted a prospective cohort study among 257 men and women living in a single dormitory in Ann Arbor, Michigan. The 3-week incidence with any serotype was 11.3% (+/-3.9%) among women and 8.8% (+/-3.0%) among men; 3-week incidence rates were highest for serotype V (4.7% for women and 3.5% for men) and type Ia (2.3% for women and 2.4% for men), with no significant differences by gender. The estimated average duration of any group B Streptococcus colonization was longer for women (13.7 weeks) than men (8.5 weeks); serotype Ia was carried an average of 6.5 weeks longer in women, and serotype III was carried 4.9 weeks longer. Colonization with more than one serotype occurred significantly less than would be expected by chance (p < 0.001). Based on the overall incidence, transmission occurred between roommate pairs at the rate expected. Group B Streptococcus colonization is frequent and dynamic, but it is not transmitted by casual contact.

  2. Geo-spatial distribution of serologically detected bovine Foot and Mouth Disease (FMD serotype outbreaks in Ilesha Baruba, Kwara State-Nigeria

    Directory of Open Access Journals (Sweden)

    Hamza Olatunde Olabode

    2014-09-01

    Full Text Available The study was aimed at assessing the prevalence and distribution of bovine Foot and Mouth Disease (FMD serotypes in Ilesha Baruba, Kwara state-Nigeria. To identify the source of epidemics, geo-spatial analysis was done on the FMD outbreak locations (n=15 using Global Positioning Service (GPS device (EtrexR. Randomly sampled bovine sera (n=64 from herd representatives were subjected to FMD 3ABC enzyme-linked immunosorbent assay (FMD 3ABC ELISA and solid-phase competitive ELISA (SP-cELISA, for the screening and serotyping of FMD virus, respectively. Through ELISA, the FMD serotypes detected in this study were- serotype O (83%; n=53/64, serotype A (7.8%; n=5/64, serotype vaccine O (1.6%; n=1/64, and serotype vaccine SAT2 (1.6%; n=1/64. Multiple serotypes were observed in two different combinations; these were O and A (4.7%; n=3/64, and O and SAT2 (1.6%; n=1/64. FMD multiple serotype infections were associated with absence of cross-immunity between serotypes and cross reactivity enhanced by clustered herds, highland study area topography, road and river interconnectivity, possible human settlements, activities and traffic. This study provides baseline information on geo-spatial distribution, and identification of prevalent FMD serotypes in Ilesha Baruba, Kwara state-Nigeria.

  3. Long-Term Epidemiology of Streptococcus pneumoniae Serogroup 6 in a Region of Southern Europe with Special Reference to Serotype 6E.

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    José M Marimón

    Full Text Available Streptococcus pneumoniae serotype 6E has recently been described, but its long-term epidemiology is not well known. From 1981-2013, 704 serogroup 6 clinical isolates were obtained in Gipuzkoa, Basque Country, Spain. All invasive and one in four non-invasive isolates were included. Overall, 75, 97, 51 and 45 serotypes 6A, 6B, 6C and 6E isolates, respectively, were detected. No serotype 6D isolates were identified. The prevalence of serotypes 6E and 6B, but not that of serotypes 6A and 6C, declined after the introduction of pneumococcal conjugate vaccines. Serotype 6E isolates showed the highest resistance rate. Most serotype 6E isolates were ST90.

  4. Molecular serotyping and identification of the 85M gragment in different Colombian isolates of Listeria monocytogenes strains: A descriptive study

    Directory of Open Access Journals (Sweden)

    María Consuelo Vanegas

    2012-02-01

    Full Text Available Introduction: Listeria monocytogenes is a pathogen acquired through the consumption of contaminated foods. Thirteen serotypes have been reported, of which 1/2a, 1/2b, and 4b are responsible for 98% of human listeriosis cases. This study examines the association between serotypes and virulent clones, offering greater information and providing tools to prevent and control diseases caused by L. monocytogenes serotype 4b.Objective: To identify the serotypes from L. monocytogene strains isolated from different samples by performing the molecular subtyping technique; to determine the 85M fragment that codifies for epidemic clone I.Methods : 108 strains of L. monocytogenes were used, isolated from samples of animals, body fluids, foods, and food processing plant equipment and spaces. The samples were identified by following the Bacteriological Analytical Manual protocol described by the Food and Drug Administration (FDA. The strains were identified by PolymeraseChain Reaction (PCR using primers and a standardized protocol from a previous research project. Serotype identification was performed by multiplex PCR. The determination of the 85M fragment of the SSCS cassette was done by following the protocol by Yildrim et al.Results : Of the 108 L. monocytogenes strains analyzed, 60.2% (65 strains belonged to the 4b-4d-4e serotype, 17.6% (19 strains were identified as 1/2a-3a serotype, 14.8% (16 strains were 4a-4c serotype, 3.7% (4 strains belonged to the 1/2c-3c serotype, and (3.7% corresponded to the 1/2b-3b-7 serotype. It was determined that the L. monocytogenes strains serotype 4b-4d-4e and 1/2a-3b have the 85M fragment of the SSCS cassette.Conclusion : This study reports the predominant existence of L. monocytogenes strains serotype 4b-4d-4e in food, environmental, and clinical samples. The presence of an epidemic clone I region was also found in L. monocytogenes strains.

  5. Streptococcus pneumoniae Serotypes and Mortality in Adults and Adolescents in South Africa: Analysis of National Surveillance Data, 2003 - 2008.

    Directory of Open Access Journals (Sweden)

    Cheryl Cohen

    Full Text Available An association between pneumococcal serotypes and mortality has been suggested. We aimed to investigate this among individuals aged ≥15 years with invasive pneumococcal disease (IPD in South Africa.IPD cases were identified through national laboratory-based surveillance at 25 sites, pre-pneumococcal conjugate vaccine (PCV introduction, from 2003-2008. We assessed the association between the 20 commonest serotypes and in-hospital mortality using logistic regression with serotype 4 (the third commonest serotype with intermediate case-fatality ratio (CFR as referent.Among 3953 IPD cases, CFR was 55% (641/1166 for meningitis and 23% (576/2484 for bacteremia (p<0.001. Serotype 19F had the highest CFR (48%, 100/207, followed by serotype 23F (39%, 99/252 and serotype 1 (38%, 246/651. On multivariable analysis, factors independently associated with mortality included serotype 1 (OR 1.9, 95%CI 1.1-3.5 and 19F (OR 2.9, 95%CI 1.4-6.1 vs. serotype 4; increasing age (25-44 years, OR 1.8, 95%CI 1.0-3.0; 45-64 years, OR 3.6, 95%CI 2.0-6.4; ≥65 years, OR 5.2, 95%CI 1.9-14.1; vs. 15-24 years; meningitis (OR 4.1, 95%CI 3.0-5.6 vs. bacteremic pneumonia; and HIV infection (OR1.7, 95%CI 1.0-2.8. On stratified multivariate analysis, serotype 19F was associated with increased mortality amongst bacteremic pneumococcal pneumonia cases, while no serotype was associated with increased mortality in meningitis cases.Mortality was increased in HIV-infected individuals, which may be reduced by increased antiretroviral therapy availability. Serotypes associated with increased mortality are included in the 10-and-13-valent PCV and may become less common in adults due to indirect effects following routine infant immunization.

  6. Detection of antibodies to Actinobacillus pleuropneumoniae serotype 12 in pig serum using a blocking enzyme-linked immunosorbent assay

    DEFF Research Database (Denmark)

    Andresen, Lars Ole; Klausen, Joan; Barfod, Kristen

    2002-01-01

    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......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...

  7. Salmonella enterica serotypes isolated from squabs reveal multidrug resistance and a distinct pathogenicity gene repertoire.

    Science.gov (United States)

    Osman, K M; Marouf, S H; Mehana, O A; AlAtfeehy, N

    2014-12-01

    The consumption of squab (young unfledged pigeons) as part of the cuisine of many countries, together with the observation that squabs are vectors of zoonotic agents, may make them a public health risk. This study was designed to determine the serotypes, distribution of 11 virulence genes (invA, avrA, ssaQ, mgtC, siiD, sopB, gipA, sodC1, sopE1, spvC, bcfC) and the antimicrobial resistance profiles of salmonellae recovered from squabs. Six isolates were identified from among 45 (13.3%) squabs sampled. Three serotypes were identified according to the Kauffmann-White serotyping scheme: Salmonella Typhimurium (4/6; 66.7%), S. Braenderup (1/6; 16.7%) and S. Lomita (1/6; 16.7%). Polymerase chain reaction analyses revealed the presence of invA, sopB and bcfC in all six isolates, whereas sopE1 and gipA were absent. All six isolates were resistant to lincomycin and streptomycin, but all were susceptible to ciprofloxacin, colistin sulphate and gentamicin. Among the S. Typhimurium isolates, seven resistance profiles were identified: penicillins,aminoglycosides,fluoroquinolones, lincosamides,phenicols, tetracyclines and sulphonamides; four resistance profiles were identified in the isolates of S. Braenderup and S. Lomita: aminoglycosides, fluoroquinolones, lincosamides and polymyxin. Thus, the distribution of resistance to the antibiotics was largely dependent on serotype identity. The presence of invA, avrA, ssaQ, mgtC, siiD, sopB and bcfC was associated with resistance to chloramphenicol; invA, sopB and bcfC with resistance to streptomycin and lincosamide; and invA and sodC1 with resistance to trimethoprim-sulfamethoxazole. The identification of serotypes S. Typhimurium, S. Braenderup and S. Lomita in the squab samples has important implications because these serotypes are significant causes of food poisoning and enteric fever in humans.

  8. Limited cross-reactivity of mouse monoclonal antibodies against Dengue virus capsid protein among four serotypes

    Directory of Open Access Journals (Sweden)

    Noda M

    2012-11-01

    Full Text Available Megumi Noda,1 Promsin Masrinoul,1 Chaweewan Punkum,1 Chonlatip Pipattanaboon,2,3 Pongrama Ramasoota,2,4 Chayanee Setthapramote,2,3 Tadahiro Sasaki,6 Mikiko Sasayama,1 Akifumi Yamashita,1,5 Takeshi Kurosu,6 Kazuyoshi Ikuta,6 Tamaki Okabayashi11Mahidol-Osaka Center for Infectious Diseases, 2Center of Excellence for Antibody Research, 3Department of Microbiology and Immunology, 4Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand; 5Graduate School of Life Science, Tohoku University, Sendai, Miyagi, 6Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, JapanBackground: Dengue illness is one of the important mosquito-borne viral diseases in tropical and subtropical regions. Four serotypes of dengue virus (DENV-1, DENV-2, DENV-3, and DENV-4 are classified in the Flavivirus genus of the family Flaviviridae. We prepared monoclonal antibodies against DENV capsid protein from mice immunized with DENV-2 and determined the cross-reactivity with each serotype of DENV and Japanese encephalitis virus.Methods and results: To clarify the relationship between the cross-reactivity of monoclonal antibodies and the diversity of these viruses, we examined the situations of flaviviruses by analyses of phylogenetic trees. Among a total of 60 prepared monoclonal antibodies specific for DENV, five monoclonal antibodies stained the nuclei of infected cells and were found to be specific to the capsid protein. Three were specific to DENV-2, while the other two were cross-reactive with DENV-2 and DENV-4. No monoclonal antibodies were cross-reactive with all four serotypes. Phylogenetic analysis of DENV amino acid sequences of the capsid protein revealed that DENV-2 and DENV-4 were clustered in the same branch, while DENV-1 and DENV-3 were clustered in the other branch. However, these classifications of the capsid protein were different from those of the

  9. Structural characterization of Streptococcus pneumoniae serotype 9A capsule polysaccharide reveals role of glycosyl 6-O-acetyltransferase wcjE in serotype 9V capsule biosynthesis and immunogenicity.

    Science.gov (United States)

    Calix, Juan J; Saad, Jamil S; Brady, Allison M; Nahm, Moon H

    2012-04-20

    The putative capsule O-acetyltransferase gene wcjE is highly conserved across various Streptococcus pneumoniae serotypes, but the role of the gene in capsule biosynthesis and bacterial fitness remains largely unclear. Isolates expressing pneumococcal serotype 9A arise from precursors expressing wcjE-associated serotype 9V through loss-of-function mutation to wcjE. To define the biosynthetic role of 9V wcjE, we characterized the structure and serological properties of serotype 9V and 9A capsule polysaccharide (PS). NMR data revealed that both 9V and 9A PS are composed of an identical pentasaccharide repeat unit, as reported previously. However, in sharp contrast to previous studies on 9A PS being devoid of any O-acetylation, we identified O-acetylation of α-glucuronic acid and α-glucose in 9A PS. In addition, 9V PS also contained -CH(2) O-acetylation of β-N-acetylmannosamine, a modification that disappeared following in vitro recombinatorial deletion of wcjE. We also show that serotyping sera and monoclonal antibodies specific for 9V and 9A bound capsule PS in an O-acetate-dependent manner. Furthermore, IgG and to a lesser extent IgM from human donors immunized with serotype 9V PS displayed stronger binding to 9V compared with 9A PS. We conclude that serotype 9V wcjE mediates 6-O-acetylation of β-N-acetylmannosamine. This PS modification can be selectively targeted by antibodies in immunized individuals, identifying a potential selective advantage for wcjE inactivation and serotype 9A emergence.

  10. The genetic organisation of the capsule biosynthesis region of Actinobacillus pleuropneumoniae serotypes 1, 6, 7, and 12

    DEFF Research Database (Denmark)

    Jessing, Stine Graakjær; Ahrens, Peter; Inzana, Thomas J.

    2008-01-01

    The aim of the present study was to investigate the organisation of the genes (cps) involved in biosynthesis the capsular polysaccharide (CPS) of Actinobacillus pleuropneumoniae serotypes 6, 7, and 12 and to compare these to the corresponding genes previously described in other A. pleuropneumoniae......C of A.pleuropneumoniae serotypes 2, 6, 7, and 8 contained a high degree of homology. At the amino acid level Cps6D revealed a high degree of homology to Cps8D, whereas Cps7D contained a high degree of homology to the Cps2D. The deduced gene product of the partially sequenced cps6E gene showed...... no homology to any deduced gene products of any cps genes of A. pleuropneumoniae investigated so far. None of the deduced gene products of the cps genes involved in encapsulation of A. pleuropneumoniae serotypes 2, 6, 7, and 8 revealed homology to the deduced gene products og the cps genes of serotypes 1, 5A...

  11. Antimicrobial activity of sweet basil and thyme against salmonella enterica serotype Enteritidis in egg-based pasta

    Directory of Open Access Journals (Sweden)

    Stojiljković Jasmina

    2015-01-01

    Full Text Available Salmonella enterica serotype Enteritidis is known as one of the most common pathogenic bacteria causing salmonellosis in humans. Raw materials of animal origin (eggs, chicken meat are frequent vectors that transmit this bacterium. Since eggs are used for the production of pasta, due to insufficient thermal treatment during pasta drying, they can be a potential risk to consumer health. Different essential oils of herbs can be used to reduce present pathogenic microorganisms. This paper compares a decrease in the number of Salmonella enterica serotype Enteritidis (D ATCC 13076 and Salmonella enterica serotype Enteritidis isolated from outbreaks of salmonellosis in egg-based pasta under the influence of thyme and sweet basil essential oils. The results indicate that the utilized oils were more effective against the epidemic strain than the ATCC strain. In addition, thyme oil caused a more significant inhibition of Salmonella enterica serotype Enteritidis during the production process.

  12. Real-time PCR for detection of Streptococcus suis serotype 2 in cerebrospinal fluid of human patients with meningitis

    Science.gov (United States)

    Nga, Tran Vu Thieu; Nghia, Ho Dang Trung; Tu, Le Thi Phuong; Diep, To Song; Mai, Nguyen Thi Hoang; Chau, Tran Thi Hong; Sinh, Dinh Xuan; Phu, Nguyen Hoan; Nga, Tran Thi Thu; Chau, Nguyen Van Vinh; Campbell, James; Hoa, Ngo Thi; Chinh, Nguyen Tran; Hien, Tran Tinh; Farrar, Jeremy; Schultsz, Constance

    2011-01-01

    Streptococcus suis serotype 2 is an emerging zoonotic pathogen and is the main cause of acute bacterial meningitis in adult patients in Vietnam. We developed an internally controlled real-time PCR for detection of S. suis serotype 2 in cerebrospinal fluid (CSF) samples targeted at the cps2J gene. Sensitivity and specificity in culture-confirmed clinical samples were 100%. The PCR detected S. suis serotype 2 infection in 101 of 238 (42.4%) prospectively collected CSF samples, of which 55 (23%) were culture positive. Culture-negative but PCR-positive CSF samples were significantly associated with the use of antimicrobial agents before admission. S. suis serotype 2 infection was more common than infections with Streptococcus pneumoniae and Neisseria meningitidis combined. Our results strikingly illustrate the additional diagnostic value of PCR in patients who are pretreated with antimicrobial agents and demonstrate the extremely high prevalence of S. suis infections among Vietnamese adult patients with bacterial meningitis. PMID:21767702

  13. Positive selection sites in the surface genes of dengue virus: phylogenetic analysis of the interserotypic branches of the four serotypes.

    Science.gov (United States)

    Rodpothong, Patsarin; Auewarakul, Prasert

    2012-06-01

    The existence of four dengue serotypes is associated with a phenomenon called "Antibody-Dependent Enhancement" that has been suggested to cause a severe form of dengue hemorrhagic fever and shock syndrome. To study the evolutionary event that drove the serotype separation, we employed the maximum likelihood approach by focusing on the Premembrane (prM) and Envelop (E) genes. We showed that the separation of dengue serotypes had been dominantly under purifying selection. In spite of the strong selective constraint, one codon of prM gene and twelve codons of E gene were detected to be under positive selection. This indicates that the E protein might have been under a stronger positive pressure than the PrM protein. The codons under positive selection were identified along the interserotypic branches, suggesting that changes at these sites were probably associated with the emergence of the four serotypes and/or adaptation to the new transmission environments.

  14. Isolation of Salmonella enterica serotype Worthington from a splenic abscess in a patient with chronic myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Ghadage D.P.

    2002-01-01

    Full Text Available Splenic abscesses are caused by Staphylococcus aureus, Streptococcus and bacteria belonging to the family Enterobacteriaceae. We report a case of splenic abscess caused by an unusual serotype of Salmonella. A 55 year old man was admitted with complaints of fever and abdominal pain. On the basis of clinical findings and laboratory reports, a diagnosis of chronic myeloid leukemia was made. Ultrasonography of the abdomen revealed a single large cystic lesion in the spleen. Percutaneous drainage of the abscess was carried out. Salmonella enterica serotype Worthington was isolated from a pus sample taken from the abscess. The isolate was resistant to ampicillin, gentamicin, cefotaxime, chloramphenicol and tetracycline, and sensitive to amikacin and norfloxacin. Serotype Worthington is an emerging pathogen. This is the first report of isolation of this serotype from a splenic abscess. In seriously ill patients, such infections should be treated with a combination of antibiotics to circumvent problems with multidrug resistance.

  15. Cloning and sequence analysis of hsf, an outer membrane protein gene of Pasteurella multocida serotype B:2

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    A. Priyadarshini

    2014-12-01

    Full Text Available Aim: The present study was undertaken to clone, sequence and analyze the hsf, an outer membrane protein gene of Pasteurella multocida serotype B:2 Materials and Methods: hsf gene was amplified from genomic DNA of P. multocida. Polymerase chain reaction (PCR product was cloned in pET-32a vector and was characterized. hsf gene was sequenced, analyzed and phylogenetic tree was constructed taking sequences of other strains. Results: Amplicon size was found to be 785 bp. Recombinant got characterized through colony PCR and restriction enzyme analysis. Conclusion: hsf gene of P. multocida serotype B is similar to serotype A, but different from serotype D. Further work is needed to evaluate role of Hsf protein in protection studies and to study the antigenic properties of this recombinant protein as a candidate for vaccine.

  16. Genome sequences of Mannheimia haemolytica serotype A1 strains D153 and D193 from bovine pneumonia

    Science.gov (United States)

    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....

  17. Genome sequences of serotype A6 Mannheimia haemolytica isolates D174 and D38 recovered from bovine pneumonia

    Science.gov (United States)

    Here we report two genomes, one complete and one draft, from virulent bovine strains of Mannheimia haemolytica(strains D174 and D38)serotype A2 recovered prior to the field usage of modern antimicrobial drugs....

  18. Evaluation of serotype-specific pneumococcal IgG measurement using two different polysaccharides from ATCC and SSI Diagnostica.

    Science.gov (United States)

    Slotved, Hans-Christian; Kantsø, Bjørn; Kerrn, Mette B; Skovsted, Ian C; Jørgensen, Charlotte S

    2011-09-02

    Streptococcus pneumoniae (pneumococcus) is a major cause of morbidity and mortality especially in infants and elderly people. Pneumococcus capsular polysaccharide has been characterised and more than 90 different serotypes have been identified. Serotype-specific antibodies against the capsular polysaccharide are produced during infection. At present, many countries follow the WHO pneumococcal ELISA IgG measurement protocol, in which polysaccharides from ATCC are used as antigens. In recent years, serotype specific polysaccharides from different producers have been tested in pneumococcal antibody assay's. In this project, purified serotype specific pneumococcal antigens from SSI Diagnostica and from ATCC were compared. In general, the data showed that both types of polysaccharide could be used as antigens. Furthermore, the effect of adsorption using different combinations of adsorption procedures was tested, showing similar results using CWPSmulti or CWPS+22F. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Pathogenic multiple antimicrobial resistant Escherichia coli serotypes in recreational waters of Mumbai, India: A potential public health risk

    Digital Repository Service at National Institute of Oceanography (India)

    Maloo A; Fulke, A; Mulani, N.; Sukumaran, S.; Ram, A

    Globally, coastal waters have emerged into a pool of antibiotic resistance genes and multiple antibiotic resistant microorganisms, and pathogenicity of these resistant microorganisms in terms of serotypes and virulence genes has made the environment...

  20. Comparative profiling of the transcriptional response to iron restriction in six serotypes of Actinobacillus pleuropneumoniae with different virulence potential

    Science.gov (United States)

    2010-01-01

    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 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 host. The combined effect of iron

  1. Comparative profiling of the transcriptional response to iron restriction in six serotypes of Actinobacillus pleuropneumoniae with different virulence potential

    Directory of Open Access Journals (Sweden)

    Angen Øystein

    2010-12-01

    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

  2. Streptococcus suis Bacterin and Subunit Vaccine Immunogenicities and Protective Efficacies against Serotypes 2 and 9▿†

    Science.gov (United States)

    Baums, Christoph Georg; Kock, Christoph; Beineke, Andreas; Bennecke, Katharina; Goethe, Ralph; Schröder, Charlotte; Waldmann, Karl-Heinz; Valentin-Weigand, Peter

    2009-01-01

    Streptococcus suis causes numerous diseases in pigs, most importantly, meningitis, arthritis, septicemia, and bronchopneumonia. One of the major problems in modern swine production is the lack of a vaccine protecting against more than one S. suis serotype. The objective of this study was to determine the protective efficacy of a serotype 2 murein-associated protein (MAP) fraction subunit vaccine in comparison to that of a bacterin against experimental challenge with serotype 2 (containing muramidase-released protein [MRP], extracellular factor, and suilysin [SLY]) and serotype 9 (containing MRP variant MRP* and SLY) strains. MAP was shown to include different surface-associated proteins, such as the MRP and surface antigen one (SAO) expressed by both pathotypes used for challenge. The results of this study demonstrated that the serotype 2 bacterin induced protective immunity against homologous challenge. In contrast, the protective efficacy of the MAP subunit vaccine was low, though MAP immunization resulted in high serum immunoglobulin G2 titers against MRP and SAO. Importantly, immunization with bacterin but not with MAP induced opsonizing antibody titers against the serotype 2 strain, and these antibody titers were found to correlate with protection. However, after absorption with a nonencapsulated isogenic mutant, the sera from bacterin-immunized piglets failed to facilitate neutrophil killing, indicating that antibodies directed against capsule may not have been essential for opsonophagocytosis. Furthermore, induction of opsonizing antibodies against serotype 9 was not detectable in the group receiving bacterin or in the group receiving the MAP vaccine. In agreement, protection against the heterologous serotype 9 strain was low in both groups. Thus, identification of an antigen protecting against these two important S. suis pathotypes remains an important goal of future studies. PMID:19109449

  3. Improved Serotype-Specific Dengue Virus Detection in Trinidad and Tobago using a Multiplex, Real-Time RT-PCR

    Science.gov (United States)

    Waggoner, Jesse J.; Sahadeo, Nikita S. D.; Brown, Arianne; Mohamed-Hadley, Alisha; Hadley, Dexter; Carrington, Leslie; Carrington, Christine V. F.; Pinsky, Benjamin A.

    2014-01-01

    Dengue virus (DENV) transmission occurs throughout the Caribbean, though laboratory confirmation and epidemiologic surveillance is limited by the availability of serotype-specific molecular diagnostics. In this study, we show that a serotype-specific DENV multiplex, real-time RT-PCR detected DENV RNA in significantly more samples (82/182) than a reference hemi-nested RT-PCR (57/182; p=0.01). PMID:25533614

  4. Detection and analysis of two serotypes of ammonia-oxidizing bacteria in sewage plants by flow cytometry.

    OpenAIRE

    Völsch, A; Nader, W F; Geiss, H. K.; Nebe, G; Birr, C

    1990-01-01

    Two different serotypes of the genus Nitrosomonas were isolated from samples of the sewage plant Heidelberg. These nitrifiers were enumerated in activated sludge of various other sewage plants after immunofluorescent labeling and staining with propidium iodide by flow cytometry. The concentrations of these serotypes of Nitrosomonas spp. were in the range of 0.1 to 2%. Also, a test for the determination of the activity of ammonia-oxidizing bacteria was developed. Nitrite-oxidizing bacteria wer...

  5. Putatively novel serotypes and the potential for reduced vaccine effectiveness: capsular locus diversity revealed among 5405 pneumococcal genomes

    Science.gov (United States)

    van Tonder, Andries J.; Bray, James E.; Quirk, Sigríður J.; Haraldsson, Gunnsteinn; Jolley, Keith A.; Maiden, Martin C. J.; Hoffmann, Steen; Bentley, Stephen D.; Haraldsson, Ásgeir; Erlendsdóttir, Helga; Kristinsson, Karl G.; Brueggemann, Angela B.

    2017-01-01

    The pneumococcus is a leading global pathogen and a key virulence factor possessed by the majority of pneumococci is an antigenic polysaccharide capsule (‘serotype’), which is encoded by the capsular (cps) locus. Approximately 100 different serotypes are known, but the extent of sequence diversity within the cps loci of individual serotypes is not well understood. Investigating serotype-specific sequence variation is crucial to the design of sequence-based serotyping methodology, understanding pneumococcal conjugate vaccine (PCV) effectiveness and the design of future PCVs. The availability of large genome datasets makes it possible to assess population-level variation among pneumococcal serotypes and in this study 5405 pneumococcal genomes were used to investigate cps locus diversity among 49 different serotypes. Pneumococci had been recovered between 1916 and 2014 from people of all ages living in 51 countries. Serotypes were deduced bioinformatically, cps locus sequences were extracted and variation was assessed within the cps locus, in the context of pneumococcal genetic lineages. Overall, cps locus sequence diversity varied markedly: low to moderate diversity was revealed among serogroups/types 1, 3, 7, 9, 11 and 22; whereas serogroups/types 6, 19, 23, 14, 15, 18, 33 and 35 displayed high diversity. Putative novel and/or hybrid cps loci were identified among all serogroups/types apart from 1, 3 and 9. This study demonstrated that cps locus sequence diversity varied widely between serogroups/types. Investigation of the biochemical structure of the polysaccharide capsule of major variants, particularly PCV-related serotypes and those that appear to be novel or hybrids, is warranted. PMID:28133541

  6. Determination of native capsular polysaccharide structures of Streptococcus pneumoniae serotypes 39, 42, and 47F and comparison to genetically or serologically related strains.

    Science.gov (United States)

    Petersen, Bent O; Meier, Sebastian; Paulsen, Berit Smestad; Redondo, Antonio R; Skovsted, Ian C

    2014-08-18

    The diversity of capsular polysaccharides of the bacterial pathogen Streptococcus pneumoniae leads to at least 91 different serotypes. While the genetic loci for capsular biosynthesis have been characterized for all serotypes, the determination of resultant polysaccharide structures remains incomplete. Here, we report the chemical structures of the capsular polysaccharides of serotypes 39, 42, and 47F from the genetic cluster 4, and discuss the structures in the context of structures from serologically and genetically related serotypes. Antigenic determinants can be approximated in this manner. The structure of the serotype 39 capsular polysaccharide is [formula: see text] and has identical composition to the capsular polysaccharide 10A, but two different linkages. The serotype 42 structure [formula: see text] closely resembles the genetically related serotype 35A, which does not contain residue A. The structure of the serotype 47F capsular polysaccharide [formula: see text] is somewhat different from a recently determined structure from the same serogroup, while containing a structural motif that is reflected in serotype 35A and 42 capsular polysaccharide structures, thus explaining the cross-reactivity of serotype 47F with the typing serum 35a.

  7. Prevalence of antimicrobial resistant Streptococcus pneumoniae serotype 11A isolates in Korea, during 2004-2013, due to the increase of multidrug-resistant clone, CC166.

    Science.gov (United States)

    Baek, Jin Yang; Kim, So Hyun; Kang, Cheol-In; Chung, Doo-Ryeon; Peck, Kyong Ran; Ko, Kwan Soo; Song, Jae-Hoon

    2016-03-01

    Since the introduction of the pneumococcal conjugate vaccine (PCV7) in Korea in 2003, the proportion of non-vaccine serotypes has increased. Among non-vaccine serotypes, serotype 11A is highly prevalent in Korea. We investigated the prevalence and characteristics of Streptococcus pneumoniae serotype 11A isolates in a Korean tertiary-care hospital, during 2004-2013. A total of 1579 non-duplicate clinical S. pneumoniae isolates, collected from 2004 to 2013, were included in this study. Serotype was determined by the capsular Quellung method, and in vitro susceptibility testing was performed by broth microdilution method. Multilocus sequence typing was performed to determine the genotypes of the S. pneumoniae isolates. We identified 90 serotype 11A isolates (5.7%). During this period, the proportion of serotype 11A has increased from 3.2% up to 13.2% (in 2012). Among the serotype 11A isolates, two main clonal complexes (CCs), CC166 and CC99, were identified. The increase of serotype 11A was mainly due to the increase of CC166 isolates, which have high antimicrobial resistance rates. In addition, we identified that 14 isolates, belonging to ST8279, ST9875, and ST3598 of CC166, were non-susceptible to all antimicrobial agents tested in this study. We identified the increase of S. pneumoniae serotype 11A in Korea, which mainly due to the expansion of a resistant clonal group, CC166.

  8. Human infections due to Salmonella Blockley, a rare serotype in South Africa: a case report

    Directory of Open Access Journals (Sweden)

    Gonose Thandubuhle

    2012-10-01

    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.

  9. Chicken serologic response to Salmonella enterica serotype Typhimurium assessed by Elisa

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    GH Oliveira

    2006-03-01

    Full Text Available This study evaluated two enzyme-linked immunosorbent assays (ELISA in the detection of chicken serologic response against Salmonella enterica sorotype Typhimurium. The assays have used as detecting antigen the soluble bacterial proteins of a non-flagellated strain of Salmonella Typhimurium (AgTM, and antibody conjugated to peroxidase or alkaline phosphatase. According to the results, optimal dilutions of antigen (concentration 5.49 mg/mL and serum samples in both assays were 1:20,000 and 1:1,000, respectively. In such conditions, the ELISA/AgTM was able to detect serological response to Salmonella Typhimurium. Cross-reactions to Salmonella serotypes Gallinarum and Pullorum were seen, but not with other serotypes such as Enteritidis.

  10. Different serotypes of dengue viruses differently regulate the expression of the host cell antigen processing machinery.

    Science.gov (United States)

    Gan, Chye Sheng; Yusof, Rohana; Othman, Shatrah

    2015-09-01

    Dengue virus (DV) infection demonstrates an intriguing virus-induced intracellular membrane alteration that results in the augmentation of major histocompatibility complex (MHC) class I-restricted antigen presentation. As oppose to its biological function in attracting CD8(+) T-cells, this phenomenon appears to facilitate the immune evasion. However, the molecular events that attribute to the dysregulation of the antigen presenting mechanism (APM) by DV remain obscure. In this study, we aimed to characterize the host cell APM upon infection with all serotypes of whole DV. Cellular RNA were isolated from infected cells and the gene expressions of LMP2, LMP7, TAP1, TAP2, TAPBP, CALR, CANX, PDIA3, HLA-A and HLA-B were analyzed via quantitative PCR. The profiles of the gene expression were further validated. We showed that all four DV serotypes modulate host APM at the proteasomal level with DV2 showing the most prominent expression profile.

  11. Molecular characteristics of serotype 3 Streptococcus pneumoniae isolates among community-acquired pneumonia patients in Japan.

    Science.gov (United States)

    Isozumi, Rie; Ito, Yutaka; Ishida, Tadashi; Hirai, Toyohiro; Ito, Isao; Maniwa, Ko; Hayashi, Michio; Kagioka, Hitoshi; Hirabayashi, Masataka; Onaru, Koichi; Tomioka, Hiromi; Tomii, Keisuke; Gohma, Iwao; Osawa, Makoto; Imai, Seiichiro; Takakura, Shunji; Iinuma, Yoshitsugu; Chin, Kazuo; Ichiyama, Satoshi; Mishima, Michiaki

    2008-06-01

    In order to understand the spread of the erythromycin-resistant serotype 3 Streptococcus pneumoniae clone in Japan, we have assessed the molecular characteristics of this clone. Among 156 S. pneumoniae isolates recovered from adults with community-acquired pneumonia between 2003 and 2005, 42 were serotype 3 and 40 were sequence type (ST) 180/Netherlands(3)-31 by multilocus sequence typing. Thirty-eight of the 40 ST 180 isolates had acquired resistance to erythromycin via the ermB gene. Although the ermB-positive ST180 clone isolates were more susceptible to penicillin and trimethoprim-sulfamethoxazole than ermB-positive non-ST180 isolates and contained a less mutated pbp1a or pbp2b gene, without a mefA gene, the ST180 clone was highly prevalent among ermB-positive isolates. Routine surveillance for the ST180 S. pneumoniae clone may soon become necessary.

  12. Isolation of avian serotype 3 paramyxoviruses from imported caged birds in Israel.

    Science.gov (United States)

    Shihmanter, E; Weisman, Y; Lublin, A; Mahani, S; Panshin, A; Lipkind, M

    1998-01-01

    Ten avian serotype 3 paramyxoviruses were isolated for the first time in Israel from passerine and psittacine imported caged birds. The birds were submitted for investigation of an illness characterized by nonspecific signs of weakness, anorexia, vomiting, and sneezing. In addition, only the parakeets developed specific neurologic signs. In bacteriologic and pathologic investigation, cachexia and diarrhea were observed in both groups of birds. In psittacines, considerable alterations were observed in lungs, liver, and spleen. Some nonviral pathogens were occasionally isolated. The isolates appeared to belong to serotype 3b avian paramyxovirus (APMV), the prototype strain of which is APMV-3b/parakeet/Netherlands/449/75. The isolation of APMV-3 viruses from imported caged birds may represent a way of introduction of these viruses into the country.

  13. [Bluetongue disease in Swiss sheep breeds: clinical signs after experimental infection with bluetongue virus serotype 8].

    Science.gov (United States)

    Worwa, G; Thür, B; Griot, C; Hofmann, M; MacLachlan, J N; Chaignat, V

    2008-10-01

    Clinical disease of bluetongue (BT) in sheep may differ depending on breed, age and immunity of infected sheep and may also vary between serotype and strain of BT virus (BTV). Since there are no data available on the susceptibility of Swiss sheep breeds for BT, we performed experimental infection of the 4 most common Swiss sheep breeds and the highly susceptible Poll Dorset sheep with the BTV serotype 8 (BTV-8) circulating in Northern Europe since 2006. Clinical signs were assessed regarding severity, localisation, progression and time point of their appearance. The results clearly show that the Swiss sheep breeds investigated were susceptible to BTV-8 infection. They developed moderate, BT-characteristic symptoms, which were similar to those observed in Poll Dorset sheep. Regardless of breed, the majority of infected animals showed fever, swelling of the head as well as erosions of the mouth and subcutaneous haemorrhages.

  14. AA479 antiserum: new reagent for the serotype characterization of atypical variants of Shigella flexneri

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    Claudia A van der Ploeg

    2015-03-01

    Full Text Available Shigella flexneri is divided into 13 serotypes based on the combination of antigenic determinants present in the O-antigen. A new O-antigen modification with phosphoethanolamine has been identified. The presence of this antigenic determinant (called E1037 is recognized by monoclonal antibody MASF IV-1. Given the increasing incidence of these new variants and the difficulty in supplying the monoclonal antibody to our country, we produced a polyclonal antiserum (AA479 through immunization with a S. flexneri Xv strain. The antiserum specificity was assessed by slide agglutination against isolates from clinical cases and a culture collection representing all Shigella serotypes. The results obtained demonstrated a 100% correlation between AA479 absorbed antiserum and monoclonal antibody MASF IV-1. The availability of AA479 antiserum in every public hospital in Argentina will allow us to identify atypical S. flexneri isolates in order to strengthen Shigella surveillance in our country and to compare with global epidemiological data.

  15. Proteomic analysis of an Aedes albopictus cell line infected with Dengue serotypes 1 and 3 viruses

    Directory of Open Access Journals (Sweden)

    Thomas Frédéric

    2011-07-01

    Full Text Available Abstract Background Proteomic analysis was performed to identify proteins regulated during infection by Dengue serotypes 1 and 3 in an Aedes albopictus cell line. The potential of these viruses to cause severe disease at primary infection is of interest although few studies have been performed with these two Dengue serotypes. Results The most relevant observation of our study is the significant overexpression of proteins involved in the cellular stress response and the glycolysis pathway after 48 hours of infection. Viral infection activates the translation of some host genes, which may result in stress due to responses involving unfolded proteins. Conclusions Therefore, the oxidation reduction and glycolytic mechanisms could participate in the antiviral response against Dengue virus. The results of our study should help to improve our knowledge of the virus-mosquito interaction at a cellular level with the aim of designing efficient strategies for the control of Dengue virus.

  16. Characterization of the omlA gene from different serotypes of Actinobacillus pleuropneumoniae: a new insight into an old approach

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    Ciro César Rossi

    2013-01-01

    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.

  17. Characterization of the omlA gene from different serotypes of Actinobacillus pleuropneumoniae: A new insight into an old approach

    Science.gov (United States)

    Rossi, Ciro César; de Araújo, Elza Fernandes; de Queiroz, Marisa Vieira; Bazzolli, Denise Mara Soares

    2013-01-01

    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. PMID:23885207

  18. Exploiting serological data to understand the epidemiology of foot-and-mouth disease virus serotypes circulating in Libya.

    Science.gov (United States)

    Eldaghayes, Ibrahim; Dayhum, Abdunaser; Kammon, Abdulwahab; Sharif, Monier; Ferrari, Giancarlo; Bartels, Christianus; Sumption, Keith; King, Donald P; Grazioli, Santina; Brocchi, Emiliana

    2017-01-01

    Sporadic outbreaks of foot-and-mouth disease (FMD) have occurred in Libya for almost fifty years. During the spring of 2013, a countrywide serosurvey was undertaken to assess the level of FMD virus circulation and identify FMD virus serotypes in the country. A total of 4221 sera were collected, comprising samples from large ruminants (LR; n=1428 samples from 357 farms) and small ruminants (SR; n=2793 samples from 141 farms). FMD sero-prevalence of NSP antibodies determined by ELISA were 19.0% (271/1428) with 95% CI (16.9 - 21.0) and 13.5% (378/2793) with 95% CI (12.3 - 14.8) for LR and SR samples, respectively. The sero-prevalence of NSP antibodies in LR was 12.3% and 19.8% for age group 2 year, respectively (X(2)= 118.1, P= 0.000). These observed NSP serologic profiles support the hypothesis of an endemic level of FMD circulation in Libya. All positive sera were tested for SP antibodies for O, A and SAT-2 FMD virus serotypes. Serotype O was the dominant circulating serotype followed by serotype A, while evidence of SAT-2 was not found. These data provide an insight into the wider epidemiology of FMD in Libya, and contribute to field and laboratory investigations that during 2013 serotype O (O/ME-SA/Ind-2001 lineage) was isolated from clinical samples collected from the country.

  19. Epidemiology of pneumococcal serotype 6A and 6C among invasive and carriage isolates from Alaska, 1986–2009☆

    Science.gov (United States)

    Rudolph, Karen; Bruce, Michael; Bruden, Dana; Zulz, Tammy; Wenger, Jay; Reasonover, Alisa; Harker-Jones, Marcella; Hurlburt, Debby; Hennessy, Thomas

    2015-01-01

    We investigated serotype 6A/6C invasive pneumococcal disease (IPD) incidence, genetic diversity, and carriage before and after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in Alaska. IPD cases (1986–2009) were identified through population-based laboratory surveillance. Isolates were initially serotyped by conventional methods, and 6C isolates were differentiated from 6A by polymerase chain reaction. Among invasive and carriage isolates initially typed as 6A, 35% and 50% were identified as 6C, respectively. IPD rates caused by serotype 6A or 6C among children <5 years did not change from the pre- to post-PCV7 period (P = 0.71 and P = 0.09, respectively). Multilocus sequence typing of IPD isolates revealed 28 sequence types. The proportion of serotype 6A carriage isolates decreased from 7.4% pre-PCV7 to 1.8% (P < 0.001) during 2008–2009; the proportion of serotype 6C carriage isolates increased from 3.0% to 8.4% (P = 0.004) among children <5 years. Continued surveillance is warranted to monitor changes in serotype distribution and prevalence. PMID:23276772

  20. Exploiting serological data to understand the epidemiology of foot-and-mouth disease virus serotypes circulating in Libya

    Science.gov (United States)

    Eldaghayes, Ibrahim; Dayhum, Abdunaser; Kammon, Abdulwahab; Sharif, Monier; Ferrari, Giancarlo; Bartels, Christianus; Sumption, Keith; King, Donald P.; Grazioli, Santina; Brocchi, Emiliana

    2017-01-01

    Sporadic outbreaks of foot-and-mouth disease (FMD) have occurred in Libya for almost fifty years. During the spring of 2013, a countrywide serosurvey was undertaken to assess the level of FMD virus circulation and identify FMD virus serotypes in the country. A total of 4221 sera were collected, comprising samples from large ruminants (LR; n=1428 samples from 357 farms) and small ruminants (SR; n=2793 samples from 141 farms). FMD sero-prevalence of NSP antibodies determined by ELISA were 19.0% (271/1428) with 95% CI (16.9 – 21.0) and 13.5% (378/2793) with 95% CI (12.3 – 14.8) for LR and SR samples, respectively. The sero-prevalence of NSP antibodies in LR was 12.3% and 19.8% for age group 2 year, respectively (X2= 118.1, P= 0.000). These observed NSP serologic profiles support the hypothesis of an endemic level of FMD circulation in Libya. All positive sera were tested for SP antibodies for O, A and SAT-2 FMD virus serotypes. Serotype O was the dominant circulating serotype followed by serotype A, while evidence of SAT-2 was not found. These data provide an insight into the wider epidemiology of FMD in Libya, and contribute to field and laboratory investigations that during 2013 serotype O (O/ME-SA/Ind-2001 lineage) was isolated from clinical samples collected from the country. PMID:28180094

  1. Exploiting serological data to understand the epidemiology of foot-and-mouth disease virus serotypes circulating in Libya

    Directory of Open Access Journals (Sweden)

    Ibrahim Eldaghayes

    2017-01-01

    Full Text Available Sporadic outbreaks of foot-and-mouth disease (FMD have occurred in Libya for almost fifty years. During the spring of 2013, a countrywide serosurvey was undertaken to assess the level of FMD virus circulation and identify FMD virus serotypes in the country. A total of 4221 sera were collected, comprising samples from large ruminants (LR; n=1428 samples from 357 farms and small ruminants (SR; n=2793 samples from 141 farms. FMD sero-prevalence of NSP antibodies determined by ELISA were 19.0% (271/1428 with 95% CI (16.9 – 21.0 and 13.5% (378/2793 with 95% CI (12.3 – 14.8 for LR and SR samples, respectively. The sero-prevalence of NSP antibodies in LR was 12.3% and 19.8% for age group 2 year, respectively (X2= 118.1, P= 0.000. These observed NSP serologic profiles support the hypothesis of an endemic level of FMD circulation in Libya. All positive sera were tested for SP antibodies for O, A and SAT-2 FMD virus serotypes. Serotype O was the dominant circulating serotype followed by serotype A, while evidence of SAT-2 was not found. These data provide an insight into the wider epidemiology of FMD in Libya, and contribute to field and laboratory investigations that during 2013 recognized serotype O (O/ME-SA/Ind-2001 lineage in clinical samples collected from the country.

  2. PspA family distribution, unlike capsular serotype, remains unaltered following introduction of the heptavalent pneumococcal conjugate vaccine.

    Science.gov (United States)

    Croney, Christina M; Coats, Mamie T; Nahm, Moon H; Briles, David E; Crain, Marilyn J

    2012-06-01

    Pneumococcal conjugate vaccines (PCVs) are recommended for the prevention of invasive pneumococcal disease (IPD) in young children. Since the introduction of the heptavalent pneumococcal vaccine (PCV7) in 2000, IPD caused by serotypes in the vaccine has almost been eliminated, and previously uncommon capsular serotypes now cause most cases of pediatric IPD in the United States. One way to protect against these strains would be to add cross-reactive protein antigens to new vaccines. One such protein is pneumococcal surface protein A (PspA). Prior to 2000, PspA families 1 and 2 were expressed by 94% of isolates. Because PCV7 vaccine pressure has resulted in IPD caused by capsular serotypes that were previously uncommon and unstudied for PspA expression, it was possible that many of the new strains expressed different PspA antigens or even lacked PspA. Of 157 pediatric invasive pneumococcal isolates collected at a large pediatric hospital in Alabama between 2002 and 2010, only 60.5% had capsular serotypes included in PCV13, which came into general use in Alabama after our strains were collected. These isolates included 17 serotypes that were not covered by PCV13. Nonetheless, pneumococcal capsular serotype replacement was not associated with changes in PspA expression; 96% of strains in this collection expressed PspA family 1 or 2. Continued surveillance will be critical to vaccine strategies to further reduce IPD.

  3. Recombinant Bivalent Vaccine against Foot-and-Mouth Disease Virus Serotype O/A Infection in Guinea Pig

    Institute of Scientific and Technical Information of China (English)

    Jian-Zhong YI; Ming-Qiu LIU; Cai-Zhu ZHU; Qiang ZHANG; Zu-Tian SHENG; Qing-Yun DU; Wei-Yao YAN; Zhao-Xin ZHENG

    2004-01-01

    In this study, two DNA fragments encoding amino acid (141-160)-(21-40)-(141-160) of the VP 1 of FMDV (foot-and-mouth disease virus) serotype O and (138-160)-(21-40)-( 138-160) of the serotype A FMDV were chemically synthesized. These two tandem-repeat fragments were ligated and transfected into prokaryotic expression vector pTrcHis A to construct pTH-O-A. The other vector called pTH-O-scIgG-A was constructed similarly only that the two tandem-repeat DNA fragments were linked by the bovineIgG heavy chain coding sequence. Guinea pigs immunized with the two bivalent vaccines pTH-O-A and pTH-O-scIgG-A showed both specific antibody activity and T cell proliferation responses. FMDV challenge tests showed that 85% and 70% of guinea pigs vaccinated twice with 200 μg of the fusion protein of pTH-O-A were protected from FMDV serotype O and serotype A infection respectively. 70% and 57%of the guinea pigs immunized with the fusion protein of pTH-O-scIgG-A were protected from FMDV serotype O and serotype A infection respectively.

  4. DNA microarray analysis of Salmonella serotype Typhimurium strains causing different symptoms of disease

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    Helms Morten

    2010-03-01

    Full Text Available Abstract Background Salmonella enterica subsp. enterica is one of the leading food-borne pathogens in the USA and European countries. Outcome of human Salmonella serotype Typhimurium infections ranges from mild self-limiting diarrhoea to severe diarrhoea that requires hospitalization. Increased knowledge of the mechanisms that are responsible for causing infection and especially the severity of infection is of high interest. Results Strains were selected from patients with mild infections (n = 9 and patients with severe infections (n = 9 and clinical data allowed us to correct for known underlying diseases. Additionally, outbreak isolates (n = 3 were selected. Strains were analyzed on a DNA-DNA microarray for presence or absence of 281 genes covering marker groups of genes related to pathogenicity, phages, antimicrobial resistance, fimbriae, mobility, serotype and metabolism. Strains showed highly similar profiles when comparing virulence associated genes, but differences between strains were detected in the prophage marker group. The Salmonella virulence plasmid was present in 72% of the strains, but presence or absence of the virulence plasmid did not correspond to disease symptoms. A dendrogram clustered strains into four groups. Clustering confirmed DT104 as being a clonal phagetype. Clustering of the remaining strains was mainly correlated to presence or absence of the virulence plasmid and mobile elements such as transposons. Each of the four clusters in the tree represented an almost equal amount of strains causing severe or mild symptoms of infection. Conclusions We investigated clinical significance of known virulence factors of Salmonella serotype Typhimurium strains causing different disease symptoms, and conclude that the few detected differences in Salmonella serotype Typhimurium do not affect outcome of human disease.

  5. Prevalence and Diversity of Salmonella Serotypes in Ecuadorian Broilers at Slaughter Age

    Science.gov (United States)

    Cevallos, María; Ron-Garrido, Lenin; Bertrand, Sophie; De Zutter, Lieven

    2016-01-01

    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. PMID:27414038

  6. Capsular serotyping of Pasteurella multocida from various animal hosts - a comparison of phenotypic and genotypic methods.

    Science.gov (United States)

    Arumugam, N D; Ajam, N; Blackall, P J; Asiah, N M; Ramlan, M; Maria, J; Yuslan, S; Thong, K L

    2011-04-01

    One hundred and fourteen strains of Pasteurella multocida were isolated from different domestic animals species (cattle, buffalo, sheep, goat, pig, rabbit, dog, cat), avian species (chicken, duck, turkey) and wild animals (deer, tiger, orang utan, marmoset). The serogroups of P. multocida were determined by both conventional capsular serotyping and a multiplex PCR assay targeting specific capsular genes. Based on the conventional serotyping method, the 114 strains of P. multocida were subtyped into 55 species-specific (untypeable strains) P. multocida, 15 serogroup A, 23 serogroup B and 21 serogroup D. Based on the multiplex PCR assay on the specific capsular genes associated with each serogroup, the 114 strains were further divided to 22 species-specific P. multocida (KMT1 - 460 bp), 53 serogroup A (A - 1,044 bp), 33 serogroup B (B - 760 bp) and 6 serogroup D (D - 657 bp). No serogroup E (511 bp) or F (851 bp) was detected among the Malaysian P. multocida. PCR-based typing was more discriminative and could further subtype the previously untypeable strains. Overall, there was a significant and positive correlation between both methods in serogrouping P. multocida (r = 0.7935; pmultocida were present among the livestock with 75% of the strains belonging to serogroups A or B. PCR serotyping was therefore a highly species-specific, sensitive and robust method for detection and differentiation of P. multocida serogroups compared to conventional serotyping. To the best of our knowledge, this is the first report from Malaysia of the application of a PCR to rapidly define the species-specific P. multocida and its serogroups as an important zoonotic pathogen in Malaysia.

  7. Prevalence, distribution of serotypes, and cariogenic potential in hamsters of mutans streptococci from elderly individuals.

    OpenAIRE

    1983-01-01

    The prevalence of mutans streptococci (Streptococcus mutans, Streptococcus cricetus, Streptococcus sobrinus, and Streptococcus rattus) was determined in the salivas of 169 elderly individuals ranging in age from 60 to 87 years. Approximately 40% of these individuals were edentulous and wore full upper and lower dentures. With the exception of a higher proportion of saliva counts below 1,000 CFU/ml in the full-denture wearers, the prevalence and the serotype and species distributions of the mu...

  8. Rare serotype occurrence and PFGE genotypic diversity of Streptococcus agalactiae isolated from tilapia in China.

    Science.gov (United States)

    Li, Liping; Wang, Rui; Liang, Wanwen; Gan, Xi; Huang, Ting; Huang, Yan; Li, Jian; Shi, Yunliang; Chen, Ming; Luo, Honglin

    2013-12-27

    Previously, we reported 10 PEGE types of 85 tilapia Streptococcus agalactiae (GBS), which shifted from Streptococcus iniae in China, by using PEGE method. Presently, larger and more representative tilapia GBS were isolated, for the first time in China, to characterize their serotypes and genetic diversities more precisely than had done before. 168 GBS strains were distributed in five provinces of China, in which Guangdong, Guangxi and Hainan were the major ones, holding 36.9% (62/168), 37.5% (63/168) and 19.6% (33/168), respectively. Serotypes, Ia, Ib and III, were observed in these strains and the most predominant one was Ia (95.2%), which mainly distributed in Guangdong, Guangxi and Hainan. Ia initially occurred in 2009, it shoot up to 32.1% in 2010, but decreased to 16.1% in 2011 before went up to 45.2% in 2012. Ib sporadically occurred during 2007-2011, III only occurred in 2012. 14 different PFGE types, including 4 new types (N, O, P and Q), were observed, in which B, D, F and G were the predominant types, holding 83.9% (141/168) of the total GBS strains. Ia corresponded to 11 PFGE types (A-H, N-P), in which type D predominated (51%). Ib represented 3 genotypes (I, J and Q) and III harbored only 2 genotypes (N and F). Type N and F synchronously presented in Ia and III. In summary, the genetic diversity of tilapia GBS varied by serotypes and changed with geographical locations and years. Although Ia still predominated, new rare serotype III already occurred in China.

  9. Serotype and genetic diversity of human rhinovirus strains that circulated in Kenya in 2008.

    Science.gov (United States)

    Milanoi, Sylvia; Ongus, Juliette R; Gachara, George; Coldren, Rodney; Bulimo, Wallace

    2016-05-01

    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.

  10. Natural strain variation and antibody neutralization of dengue serotype 3 viruses.

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    Wahala M P B Wahala

    2010-03-01

    Full Text Available Dengue viruses (DENVs are emerging, mosquito-borne flaviviruses which cause dengue fever and dengue hemorrhagic fever. The DENV complex consists of 4 serotypes designated DENV1-DENV4. Following natural infection with DENV, individuals develop serotype specific, neutralizing antibody responses. Monoclonal antibodies (MAbs have been used to map neutralizing epitopes on dengue and other flaviviruses. Most serotype-specific, neutralizing MAbs bind to the lateral ridge of domain III of E protein (EDIII. It has been widely assumed that the EDIII lateral ridge epitope is conserved within each DENV serotype and a good target for vaccines. Using phylogenetic methods, we compared the amino acid sequence of 175 E proteins representing the different genotypes of DENV3 and identified a panel of surface exposed amino acids, including residues in EDIII, that are highly variant across the four DENV3 genotypes. The variable amino acids include six residues at the lateral ridge of EDIII. We used a panel of DENV3 mouse MAbs to assess the functional significance of naturally occurring amino acid variation. From the panel of antibodies, we identified three neutralizing MAbs that bound to EDIII of DENV3. Recombinant proteins and naturally occurring variant viruses were used to map the binding sites of the three MAbs. The three MAbs bound to overlapping but distinct epitopes on EDIII. Our empirical studies clearly demonstrate that the antibody binding and neutralization capacity of two MAbs was strongly influenced by naturally occurring mutations in DENV3. Our data demonstrate that the lateral ridge "type specific" epitope is not conserved between strains of DENV3. This variability should be considered when designing and evaluating DENV vaccines, especially those targeting EDIII.

  11. Multilocus sequence typing as a replacement for serotyping in Salmonella enterica.

    Directory of Open Access Journals (Sweden)

    Mark Achtman

    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.

  12. Salmonella enterica Serotype Typhi Bacteremia Complicating Pregnancy in the Third Trimester

    Science.gov (United States)

    Patel, Krunal; Gittens-Williams, Lisa; Apuzzio, Joseph J.; Martimucci, Kristina; Williams, Shauna F.

    2017-01-01

    Background. Salmonella enterica serotype Typhi (S. Typhi) is an anaerobic gram-negative enteric rod that causes infection when contaminated food or water is ingested and may cause illness in pregnancy. Case. This is a patient who presented at 31 weeks' gestation with abdominal pain and fever and was diagnosed with S. Typhi bacteremia. Conclusion. S. Typhi should be considered in febrile patients with recent travel presenting with abdominal discomfort with or without elevated liver enzymes. PMID:28203469

  13. Rabbit and human hepatitis E virus strains belong to a single serotype.

    Science.gov (United States)

    Wang, Song; Cheng, Xianfeng; Dai, Xing; Dong, Chen; Xu, Mingjie; Liang, Jiuhong; Dong, Min; Purdy, Michael A; Meng, Jihong

    2013-09-01

    Hepatitis E virus (HEV) is a zoonotic pathogen and all four established genotypes of HEV belong to a single serotype. The recently identified rabbit HEV is antigenically and genetically related to human HEV. It is unclear whether rabbit HEV belongs to the same serotype as human HEV. The purpose of this study was to determine the serotypic relationship between rabbit and human HEVs. HEV ORF2 recombinant capsid protein p166 (amino acids 452-617) of four known HEV genotypes and rabbit HEV were used to induce immune serum, which were evaluated for their ability to neutralize human HEV genotype 1, 4, and rabbit HEV strains by an in vitro PCR-based HEV neutralization assay. Immune sera of five kinds of p166 proteins were all found to neutralize or cross-neutralize the three different HEV strains, suggesting a common neutralization epitope(s) existing between human and rabbit HEV. Rabbit models of a second-passage rabbit HEV strain, JS204-2, and a genotype 4 human HEV strain, NJ703, were established as evidenced by fecal virus shedding, viremia and anti-HEV IgG seroconversion. Six rabbits, recovered from JS204 infection, were challenged with NJ703, and another six recovered from NJ703 infection were challenged with JS204-2. After challenge, viremia was not detected, shorter fecal virus shedding durations and obvious early stage declines in anti-HEV IgG values were observed. The results from this study indicate that rabbit HEV belongs to the same serotype as human HEV.

  14. Septic arthritis and hemarthroses caused by Haemophilus influenzae serotype A in children

    Directory of Open Access Journals (Sweden)

    Ravi S. Samraj

    2016-09-01

    Full Text Available Invasive disease caused by Haemophilus influenzae serotype A (Hia is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

  15. Septic Arthritis and Hemarthroses Caused by Haemophilus Influenzae Serotype A in Children

    Science.gov (United States)

    Samraj, Ravi S.; Fergie, Jaime

    2016-01-01

    Invasive disease caused by Haemophilus influenzae serotype A (Hia) is rare in children. Clinical syndromes caused by Hia include meningitis, sepsis and respiratory tract infections. Septic arthritis is rare in children with invasive Hia infection and hemarthrosis has not been described in the published literature. We report a case of septic arthritis and hemarthrosis caused by Hia infection in a 2.5 year-old-boy and review invasive Hia infection in children.

  16. “SALMONELLA ENTERICA SEROTYPE CHOLERAESUIS, A RARE PATHOGEN – REPORT OF TWO CASES

    OpenAIRE

    Shilpa R; Sunanda A; Usha S; Sara S; Shashikant H.

    2013-01-01

    ABSTRACT: Nontyphoidal salmonellosis is well known clinical en tity. Outbreaks of gastroenteritis, septicemia and meningitis caused by different nontyphoidal salmonellae have been reported in the past. S. choleraesuis is the hig hly swine adapted serotype of salmonella causing swine paratyphoid. It is extremely invasive and may be isolated from other animals, including man. We report two cases of S. cholerasuis infections, o ne in electric burn wound and the ...

  17. Antimicrobial Resistance of Shigella flexneri Serotype 1b Isolates in China.

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    Xianyan Cui

    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.

  18. Novel Ganglioside-mediated Entry of Botulinum Neurotoxin Serotype D into Neurons

    Energy Technology Data Exchange (ETDEWEB)

    Kroken, Abby R.; Karalewitz, Andrew P.-A.; Fu, Zhuji; Kim, Jung-Ja P.; Barbieri, Joseph T. (MCW)

    2012-02-07

    Botulinum Neurotoxins (BoNTs) are organized into seven serotypes, A-G. Although several BoNT serotypes enter neurons through synaptic vesicle cycling utilizing dual receptors (a ganglioside and a synaptic vesicle-associated protein), the entry pathway of BoNT/D is less well understood. Although BoNT/D entry is ganglioside-dependent, alignment and structural studies show that BoNT/D lacks key residues within a conserved ganglioside binding pocket that are present in BoNT serotypes A, B, E, F, and G, which indicate that BoNT/D-ganglioside interactions may be unique. In this study BoNT/D is shown to have a unique association with ganglioside relative to the other BoNT serotypes, utilizing a ganglioside binding loop (GBL, residues Tyr-1235-Ala-1245) within the receptor binding domain of BoNT/D (HCR/D) via b-series gangliosides, including GT1b, GD1b, and GD2. HCR/D bound gangliosides and entered neurons dependent upon the aromatic ring of Phe-1240 within the GBL. This is the first BoNT-ganglioside interaction that is mediated by a phenylalanine. In contrast, Trp-1238, located near the N terminus of the ganglioside binding loop, was mostly solvent-inaccessible and appeared to contribute to maintaining the loop structure. BoNT/D entry and intoxication were enhanced by membrane depolarization via synaptic vesicle cycling, where HCR/D colocalized with synaptophysin, a synaptic vesicle marker, but immunoprecipitation experiments did not detect direct association with synaptic vesicle protein 2. Thus, BoNT/D utilizes unique associations with gangliosides and synaptic vesicles to enter neurons, which may facilitate new neurotoxin therapies.

  19. Time-Varying, Serotype-Specific Force of Infection of Dengue Virus

    Science.gov (United States)

    2014-05-20

    interval-censored infections. The top panel shows the total number of active participants across cohort studies from 1999 to 2010. The absence of a...July 2004) which does not necessarily mean that all of these individuals were actually infected in July. Owing to the gap between cohort studies from...with the others. If Iquitos begins to sustain simultaneous transmission of all four serotypes, the maintenance of longitudinal cohort studies will pro

  20. Characterization of the 2013 dengue epidemic in Myanmar with dengue virus 1 as the dominant serotype.

    Science.gov (United States)

    Ngwe Tun, Mya Myat; Kyaw, Aung Kyaw; Makki, Nader; Muthugala, Rohitha; Nabeshima, Takeshi; Inoue, Shingo; Hayasaka, Daisuke; Moi, Meng Ling; Buerano, Corazon C; Thwe, Saw Myat; Thant, Kyaw Zin; Morita, Kouichi

    2016-09-01

    In 2013 in Myanmar, dengue epidemic occurred with 20,255 cases including 84 deaths. This study aimed to determine the serological and molecular characteristics of dengue virus (DENV) infection among children with clinical diagnosis of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) during this period. Single acute serum samples were collected from 300 children in Mandalay Children Hospital, Mandalay, Myanmar. Out of the 300 children, 175 (58.3%) and 183 (61%) were positive for anti-dengue IgM and anti-dengue IgG, respectively. Among the IgM positives, 41 (23.4%) had primary DENV infection. Thirty-nine DENV strains (23 DENV-1, 10 DENV-2 and 6 DENV-4) were successfully isolated after inoculation of the patient serum samples onto C6/36 cells. DENV 1 was the dominant serotype in the 2013 epidemic. There was no correlation between the infecting serotypes and clinical severities. The DENV-1 strains belonged to three lineages of the genotype 1; the DENV-2 strains were of the Asian I genotype and were separated into two lineages; and DENV-4 strains belonged to the same lineage of genotype I. It is of interest to note the diversity of DENV-1 and -2 circulating in the same location during June-August 2013. These DENV isolates were genetically close (98%-100%) to the other previously reported isolates from Myanmar and its neighboring countries, namely China, Thailand, Sri Lanka, Cambodia and Vietnam. Primary DENV infection was still high among the severe dengue cases. Different serotypes of DENV were co-circulating in 2013, however, genotype shift was not observed. Additionally, amino acid mutations were detected in the study strains not seen in the previously reported strains from other countries and Myanmar. This paper provided information on the circulating serotypes for the last 15years and the recent dengue situation in Mandalay, Myanmar after 2006. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Production of bacteremia and meningitis in infant rats with group B streptococcal serotypes.

    OpenAIRE

    Ferrieri, P; Burke, B; Nelson, J.

    1980-01-01

    Group B streptococcal strains, representing the five major serotypes, were inoculated into infant rats by intranasal, oral, and intraperitoneal routes. Bacteremia regularly followed injection by the intraperitoneal route. Four strains (three of type III) isolated from human cerebrospinal fluid appeared more virulent for 5-day-old rats. Injection of fewer than 10 colony-forming units of one strain, a type III, led to bacteremia and death in 27% of animals. The cumulative bacteremia and mortali...

  2. Towards the development of a DNA-sequence based approach to serotyping of Salmonella enterica

    Directory of Open Access Journals (Sweden)

    Logan Julie MJ

    2004-08-01

    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.

  3. Development of Polioencephalomyelitis in Cesarean-Derived Colostrum-Deprived Pigs Following Experimental Inoculation with Either Teschovirus A Serotype 2 or Serotype 11.

    Science.gov (United States)

    Matias Ferreyra, Franco; Arruda, Bailey; Stevenson, Gregory; Schwartz, Kent; Madson, Darin; Yoon, Kyoung-Jin; Zhang, Jianqiang; Piñeyro, Pablo; Chen, Qi; Arruda, Paulo

    2017-07-08

    Teschovirus encephalomyelitis is a sporadic disease associated with Teschovirus A (PTV) serotype 1 and, less frequently, other serotypes. In recent years, the number of cases submitted to the Iowa State University Veterinary Diagnostic Laboratory with a history of posterior paresis has increased. Submission histories from various regions of the United States suggest a trend for clinical disease to persist in herds and affect a wider age-range of pigs than historically reported. Polioencephalitis and/or myelitis was consistently present and PTV was detected in affected neural tissue by PCR in a portion of cases. Sequencing from two clinical cases identified PTV-2 and PTV-11. To assess neuropathogenicity of these isolates, 5-week-old cesarean derived and colostrum-deprived pigs were assigned to three groups: negative control (n = 4), PTV-2-inoculated (n = 7), and PTV-11-inoculated (n = 7). Three PTV-2-inoculated pigs developed mild incoordination of the hind limbs, one of which progressed to posterior ataxia. While all PTV-11-inoculated pigs showed severe neurological signs consistent with Teschovirus encephalomyelitis, no evidences of neurological signs were observed in sham-inoculated animals. All PTV-2- and PTV-11-inoculated pigs had microscopic lesions consistent with Teschovirus encephalomyelitis. To our knowledge, this is the first description of PTV-11 and experimental study demonstrating the neuropathogenicity of PTV-11 in the United States.

  4. A Monoclonal Antibody Based Capture ELISA for Botulinum Neurotoxin Serotype B: Toxin Detection in Food

    Directory of Open Access Journals (Sweden)

    Larry H. Stanker

    2013-11-01

    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.

  5. Prevalent serotypes of Pasteurella multocida isolated from different animal and avian species in India.

    Science.gov (United States)

    Kumar, A A; Shivachandra, S B; Biswas, A; Singh, V P; Singh, Vijendra P; Srivastava, S K

    2004-11-01

    Identification and estimation of the prevalence of Pasteurella multocida organisms in different animal and avian species in India during November 2000 to July 2003 was carried out. Out of 418 samples collected from different outbreaks suspected to be caused by P. multocida, a total of 206 bacterial cultures were identified as P. multocida on the basis of cultural, morphological and biochemical characteristics. All the 206 cultures were isolated from different domestic animal species (cattle, buffalo, sheep, goat, pig and rabbit), avian species (chicken, duck, quail, turkey, goose) and wild animals such as leopard and deer. Serotyping of P. multocida cultures revealed the presence of various serotypes (A:1, A:3, A:1,3, A:4, B:2, D:1 and -:1) among the livestock population. P. multocida polymerase chain reaction (PCR) assay applied on different forms of bacterial cultures (bacterial culture lysate, direct bacterial colony and mixed bacterial culture lysate) yielded an amplified product of approximately 460 bp specific for P. multocida. The results of PCR assay correlated well with conventional methods of identification. The present investigation revealed the presence of varied serotypes among livestock and PCR assay was found to be useful for rapid, sensitive and specific diagnosis of pasteurellosis in animals and avian species.

  6. Genomic characterization of Pasteurella multocida HB01, a serotype A bovine isolate from China.

    Science.gov (United States)

    Peng, Zhong; Liang, Wan; Liu, Wenjing; Wu, Bin; Tang, Biao; Tan, Chen; Zhou, Rui; Chen, Huanchun

    2016-04-25

    Pasteurella multocida infects various domestic and feral animals, generally causing clinical disease. To investigate P. multocida disease in cattle, we sequenced the complete genome of P. multocida HB01 (GenBank accession CP006976), a serotype A organism isolated from a cow in China. The genome is composed of a single circular chromosome of 2,416,068 base pairs containing 2212 protein-coding sequences, 6 ribosomal rRNA operons, and 56 tRNA genes. The present study confirms that P. multocida HB01 possesses a more complete metabolic pathway with an intact trichloroacetic acid cycle for anabolism compared with A. pleuropneumoniae and Haemophilus parasuis. This is the first time that this metabolic mechanism of P. multocida has been described. We also identified a full spectrum of genes related to known virulence factors of P. multocida. The differences in virulence factors between strains of different serotypes and origins were also compared. This comprehensive comparative genome analysis will help in further studies of the metabolic pathways, genetic basis of serotype, and virulence of P. multocida.

  7. Screening, detection, and serotyping methods for toxin genes and enterotoxins in Staphylococcus strains.

    Science.gov (United States)

    Hait, Jennifer M; Tallent, Sandra M; Bennett, Reginald W

    2014-01-01

    Staphylococcus aureus continues to play a significant role in foodborne outbreak investigations, with numerous individuals sickened each year after ingesting assorted foods contaminated with staphylococcal enterotoxins. The purpose of this study was to evaluate the use of several methods for the screening, detection, and enterotoxin serotyping of staphylococcal bacterial strains for classical staphylococcal enterotoxins (SEs; SEA, SEB, SEC, SED, and SEE) and the newly described SE and SE-like enterotoxin genes (seg, seh, sei, sej, sek, sel, sem, sen, seo, sep, seq, ser, ses, set, and seu). Inclusivity and exclusivity panels of staphylococcal strains were tested using a multiplex PCR method in addition to three polyvalent commercially prepared ELISA systems for the detection of SEA-SEE and one monovalent assay for the identification of classical SE serotypes. The results indicate an overall agreement between serological detection methods with a few exceptions, and molecular characterization identified an abundance of SE and SE-like enterotoxin genes including several potentially enterotoxigenic isolates that would have otherwise been missed by ELISA-based methods. These findings demonstrate the significance of PCR for future screening purposes and the use of ELISA systems for the detection and enterotoxin serotyping of staphylococcal bacterial strains.

  8. Genomic Analysis of a Serotype 5 Streptococcus pneumoniae Outbreak in British Columbia, Canada, 2005–2009

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    Ruth R. Miller

    2016-01-01

    Full Text Available Background. Streptococcus pneumoniae can cause a wide spectrum of disease, including invasive pneumococcal disease (IPD. From 2005 to 2009 an outbreak of IPD occurred in Western Canada, caused by a S. pneumoniae strain with multilocus sequence type (MLST 289 and serotype 5. We sought to investigate the incidence of IPD due to this S. pneumoniae strain and to characterize the outbreak in British Columbia using whole-genome sequencing. Methods. IPD was defined according to Public Health Agency of Canada guidelines. Two isolates representing the beginning and end of the outbreak were whole-genome sequenced. The sequences were analyzed for single nucleotide variants (SNVs and putative genomic islands. Results. The peak of the outbreak in British Columbia was in 2006, when 57% of invasive S. pneumoniae isolates were serotype 5. Comparison of two whole-genome sequenced strains showed only 10 SNVs between them. A 15.5 kb genomic island was identified in outbreak strains, allowing the design of a PCR assay to track the spread of the outbreak strain. Discussion. We show that the serotype 5 MLST 289 strain contains a distinguishing genomic island, which remained genetically consistent over time. Whole-genome sequencing holds great promise for real-time characterization of outbreaks in the future and may allow responses tailored to characteristics identified in the genome.

  9. [Serotypes of urease producing Vibrio parahaemolyticus and their relation to possession of tdh and trh genes].

    Science.gov (United States)

    Suzuki, N; Ueda, Y; Mori, H; Miyagi, K; Noda, K; Hirose, H; Oosumi, Y; Ishibashi, M; Yoh, M; Yamamoto, K

    1994-09-01

    We analysed 467 isolates of Vibrio parahaemolyticus for possession of tdh/trh gene in comparison with urease production and serotypes. Strains possessing tdh+/trh-, tdh+/trh+, tdh-/trh-, and tdh-/trh- show positive urease production 2.1, 100, 65.7, 100%, respectively. Serotypes of O1:K69, O3:K6, O3:K72, O6:K18, O6:K46 and O1:KUT were frequently positive (100% except 91.7% of the latest one) in urease production. All isolates of O3:K6 prossessed trh, whereas all isolates of certain serotypes including O1:K69 and O3:K72 possessed both trh and trh and tdh genes. Among these, most of O1:K69 and O3:K72 were urease producer. From these results, we speculate that urease production is closely related to the presence of the trh gene or/and lesser production of TDH. We also found the new combination of serovar, O3:K25, O4:K37 and O13:K72 in Kanagawa phenomenon-positive strains.

  10. The fate of two Listeria monocytogenes serotypes in "cig kofte" at different storage temperatures.

    Science.gov (United States)

    Durmaz, Hisamettin; Sagun, Emrullah; Sancak, Hakan; Sagdic, Osman

    2007-05-01

    Cig kofte is a traditional Turkish food prepared from minced beef, bulgur, onions, garlic and varieties of spices. It is generally consumed within a few hours. However, leftovers can be kept in refrigerator or in room temperature up to 24h until they are consumed. In this study, survival and growth of two Listeria monocytogenes serotypes were investigated in cig kofte during the storage. For this purpose, the prepared samples were separately contaminated with serotypes 1/2b or 4b of L. monocytogenes at the level of 10(4)CFU/g and stored at 4°C and 21°C. L. monocytogenes colonies were counted at the beginning, 3rd, 6th, 12th and 24th hours of the storage. At 4°C, L. monocytogenes 4b significantly increased (P0.05) during the storage period. At 21°C, both L. monocytogenes 1/2b and 4b increased significantly (Pcig kofte did not inhibit the growths of L. monocytogenes serotypes during the storage. These results indicated that L. monocytogenes was able to survive and grow in cig kofte at the both storage temperatures of 4°C and 21°C and cig kofte seemed to be a suitable medium for this pathogen.

  11. Genetic analysis of the capsular biosynthetic locus from all 90 pneumococcal serotypes.

    Directory of Open Access Journals (Sweden)

    Stephen D Bentley

    2006-03-01

    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.

  12. A duplex real-time RT-PCR assay for profiling inhibitors of four dengue serotypes.

    Science.gov (United States)

    Gong, Edwin Yunhao; Smets, Alexandra; Verheyen, Nick; Clynhens, Marleen; Gustin, Emmanuel; Lory, Pedro; Kraus, Guenter

    2013-01-01

    We have developed a duplex real-time RT-PCR assay for profiling antiviral inhibitors of four dengue virus (DENV) serotypes. In this assay, the primers and the probe for amplifying DENV were designed in the conserved regions of the genome after aligned more than 300 nucleotide sequences of four dengue serotypes deposited in the GeneBank. To discriminate the antiviral activity from the cytotoxicity of compounds, a housekeeping gene of the Vero cells, β-actin, was used to design the primers and the probe for the second set of PCR as an internal control, which is used to normalize the RNA levels of dengue-specific PCR due to the cellular toxicity of test compounds. For compound profiling, the duplex PCR is performed using LightCycler(®) in a single tube to simultaneously amplify both the dengue target gene and the Vero cell housekeeping gene from the compound-treated Vero cell lysates. This assay was validated against a panel of reference compounds. The results show that the universal primers and probe in this duplex RT-PCR assay can efficiently amplify all four dengue serotypes and that the PCR efficiency for both the dengue target gene and the Vero cells β-actin gene is 100%.

  13. In silico antigenic site evaluation and antiviral therapy against dengue serotypes

    Directory of Open Access Journals (Sweden)

    Pratap Parida

    2014-03-01

    Full Text Available Non Structural protein 3 (NS3 constitute protease, helicase and polymerase that are essential for dengue virus replication. The aim of the present study is to block the replication of the virus by targeting the NS3 Protein. The retrieved sequences of NS3 protein from National Centre for Biotechnology information (NCBI shows that the antigenic sites of the protein are highly variable in all the four serotypes of dengue virus (DENV i.e. DENV I, DENV II, DENV III and DENV IV. DENV III found to be most distantly related serotype among all the serotypes studied using UPGMA method. The 3D structure of NS3 protein was modeled using homology modeling by MODELLER 9v8. Evaluation of the constructed NS3 protein models were done by PROCHECK, WhatIf using Exome Horizon. The derived compounds of mycophenolic acid and ribavirin were docked as ligands to the constructed models of NS3 protein using Autodock 4.2 for Protein-ligand interaction study.

  14. Dengue reporter virus particles for measuring neutralizing antibodies against each of the four dengue serotypes.

    Science.gov (United States)

    Mattia, Kimberly; Puffer, Bridget A; Williams, Katherine L; Gonzalez, Ritela; Murray, Meredith; Sluzas, Emily; Pagano, Dan; Ajith, Sandya; Bower, Megan; Berdougo, Eli; Harris, Eva; Doranz, Benjamin J

    2011-01-01

    The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV) antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs) was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT) results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination.

  15. Dengue reporter virus particles for measuring neutralizing antibodies against each of the four dengue serotypes.

    Directory of Open Access Journals (Sweden)

    Kimberly Mattia

    Full Text Available The lack of reliable, high-throughput tools for characterizing anti-dengue virus (DENV antibodies in large numbers of serum samples has been an obstacle in understanding the impact of neutralizing antibodies on disease progression and vaccine efficacy. A reporter system using pseudoinfectious DENV reporter virus particles (RVPs was previously developed by others to facilitate the genetic manipulation and biological characterization of DENV virions. In the current study, we demonstrate the diagnostic utility of DENV RVPs for measuring neutralizing antibodies in human serum samples against all four DENV serotypes, with attention to the suitability of DENV RVPs for large-scale, long-term studies. DENV RVPs used against human sera yielded serotype-specific responses and reproducible neutralization titers that were in statistical agreement with Plaque Reduction Neutralization Test (PRNT results. DENV RVPs were also used to measure neutralization titers against the four DENV serotypes in a panel of human sera from a clinical study of dengue patients. The high-throughput capability, stability, rapidity, and reproducibility of assays using DENV RVPs offer advantages for detecting immune responses that can be applied to large-scale clinical studies of DENV infection and vaccination.

  16. Using amplified fragment length polymorphism analysis to differentiate isolates of Pasteurella multocida serotype 1

    Science.gov (United States)

    Blehert, D.S.; Jefferson, K.L.; Heisey, D.M.; Samuel, M.D.; Berlowski, B.M.; Shadduck, D.J.

    2008-01-01

    Avian cholera, an infectious disease caused by the bacterium Pasteurella multocida, kills thousands of North American wild waterfowl annually. Pasteurella multocida serotype 1 isolates cultured during a laboratory challenge study of Mallards (Anas platyrhynchos) and collected from wild birds and environmental samples during avian cholera outbreaks were characterized using amplified fragment length polymorphism (AFLP) analysis, a whole-genome DNA fingerprinting technique. Comparison of the AFLP profiles of 53 isolates from the laboratory challenge demonstrated that P. multocida underwent genetic changes during a 3-mo period. Analysis of 120 P. multocida serotype 1 isolates collected from wild birds and environmental samples revealed that isolates were distinguishable from one another based on regional and temporal genetic characteristics. Thus, AFLP analysis had the ability to distinguish P. multocida isolates of the same serotype by detecting spatiotemporal genetic changes and provides a tool to advance the study of avian cholera epidemiology. Further application of AFLP technology to the examination of wild bird avian cholera outbreaks may facilitate more effective management of this disease by providing the potential to investigate correlations between virulence and P. multocida genotypes, to identify affiliations between bird species and bacterial genotypes, and to elucidate the role of specific bird species in disease transmission. ?? Wildlife Disease Association 2008.

  17. Serotype, virulence, and genetic traits of foodborne and clinical Vibrio parahaemolyticus isolates in Shanghai, China.

    Science.gov (United States)

    Zhang, Hongzhi; Sun, Shuangfu; Shi, Weimin; Cui, Lin; Gu, Qifang

    2013-09-01

    Vibrio parahaemolyticus is a major foodborne pathogen in China and other countries. In this study, a total of 578 clinical V. parahaemolyticus strains and 51 foodborne strains were isolated during the period from 2009 to 2011 in the eastern coastal city of Shanghai, China. Their serotypes, virulence genes, pandemic traits, and genotyping were investigated. A total of nine O groups and 20 K types were identified by serological analysis of all isolates. Six different O groups and 14 different K types were detected among the 578 clinical strains. Eight different O groups and five K types were detected among the 51 foodborne strains. The O3:K6 serotype was the dominant serotype. A total of 200 representative clinical strains and 51 foodborne isolates were analyzed for virulence genes, pandemic traits, and genotyping. Of the clinical strains, 92.5% had the virulence genes tdh and/or trh. Four foodborne isolates had virulence genes; one trh-positive strain was O3:K6 and three tdh-positive strains were either O4:KUT or O3:KUT. Molecular typing by pulsed-field gel electrophoresis also showed divergence among the nonpandemic strains, although the pandemic strains formed a cluster. These results suggest high serodiversity and genetic diversity of V. parahaemolyticus. Pathogenic isolates were present in food, thus representing a public health risk and warranting epidemiological and ecological monitoring to ensure safety.

  18. Utilization of a molecular serotyping method for Salmonella enterica in a routine laboratory in Alberta Canada.

    Science.gov (United States)

    Ferrato, Christina; Chui, Linda; King, Robin; Louie, Marie

    2017-04-01

    Salmonella is one of the most common enteric pathogens related to foodborne illness. Alberta's Provincial Laboratory for Public Health (ProvLab) provides Outbreak and Surveillance support by performing serotyping. The Check&Trace Salmonella™ (CTS) assay (Check-Points, Netherlands), a commercial DNA microarray system, can determine the serotype designation of a Salmonella isolate with automated interpretation. Here we evaluate 1028 Salmonella isolates of human clinical or environmental sources in Alberta, Canada with the CTS assay. CTS was able to assign a serovar to 98.7% of the most frequently occurring human clinical strains in Alberta (82.5% overall), and 71.7% of isolates which were inconclusive by conventional methods. There was 99.7% concordance in environmental isolates. The CTS database has potential to expand to identify rare serovars. With the anticipated shift to molecular methods for identification, CTS provides an easy transition and demonstrates ease-of-use and reduces the turn-around-time of a reported result significantly compared to classical serotyping.

  19. Differences in antimicrobial activity of chlorine against twelve most prevalent poultry-associated Salmonella serotypes.

    Science.gov (United States)

    Paul, Narayan C; Sullivan, Tarah S; Shah, Devendra H

    2017-06-01

    Chlorine is the most widely used carcass sanitizer in poultry processing in the USA. The objective of this study was to determine the effects of varying concentrations of organic matter on the susceptibility of twelve most prevalent poultry-associated Salmonella serotypes (MPPSTs) to chlorine. To mimic the microenvironment of the water used for immersion chilling, we manipulated organic matter contamination levels in pre-chilled (pH∼6, T∼4 °C) chlorinated (50 ppm) water using varying concentrations (0, 1, 2, 3, 4, and 5%) of chicken-meat-extract (CME) produced from frozen chicken carcasses. This CME-based in vitro model was challenged with ∼1 × 10(5) CFUs of each MPPST isolate and the bacterial survival was tested at 5, 30, 60 and 90 min post-challenge. In this model, the decimal reduction time (D90-values) of each MPPST was linearly correlated with the concentration of CME. Significant inter-serotype differences in the D90-values were observed. The results show that the pH, concentration of total- and free-chlorine were also linearly correlated with the presence of CME in a concentration-dependent manner. The findings of this study indicate that the serotype and the levels of organic matter contamination significantly influence Salmonella survival and that both variables should be included in models that predict effectiveness of chlorine treatment in immersion chilling.

  20. Dengue serotype immune-interactions and their consequences for vaccine impact predictions

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    José Lourenço

    2016-09-01

    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.

  1. Antimicrobial susceptibility pattern in children with typhoid fever and serotype of Salmonella typhi in Jakarta

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    Mirari Prasadajudio, Mulya Rahma Karyanti, Lia Waslia

    2017-03-01

    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

  2. Streptococcus pneumoniae serotype distribution in Vojvodina before the introduction of pneumococcal conjugate vaccines into the national immunization program

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    Petrović Vladimir

    2016-01-01

    Full Text Available Introduction. Streptococcus pneumoniae is the most common causative agent of bacterial pneumonia and meningitis. Mandatory childhood immunization against pneumococcal diseases is introduced in the new Law on Protection of Population against Communicable Diseases in Serbia. Objective. The objective of this study was to determine the prevalence of pneumococcal serotype distribution in Vojvodina region before routine use of pneumococcal conjugate vaccine in Serbia. Methods. A total of 105 isolates of Streptococcus pneumoniae were collected in the period from January 2009 to April 2016. Based on the results of serotyping in the National Reference Laboratory, we analyzed distribution of circulating serotypes and coverage of conjugate and 23-valent polysaccharide pneumococcal vaccines in different age groups. Results. Among 105 isolates, a total of 21 different serotypes of Streptococcus pneumoniae were determined. The most frequent serotypes were 3 (21.9%, 19F (20.0%, and 14 (10.5%. The serotype coverage of pneumococcal conjugate vaccines (PCV7, PCV10, and PCV13 was 48.6%, 54.3%, and 84.8%, respectively, while pneumococcal polysaccharide vaccine (PPV23 covered 89.5% of the total number of isolates in all age groups. Serotypes included in PCV7, PCV10, and PCV13 represented 72.0%, 76.0%, and 88.0% of the total number of isolates in children ≤5 years, respectively. Vaccine serotype coverage of PCV13 and PPV23 ranged from 87.1% to 90.3% in adults 50-64 years of age, and 77.8% to 85.2% in adults ≥65 years old. Conclusion. Serotype distribution of Streptococcus pneumoniae in the population fairly overlaps with the serotypes contained in pneumococcal vaccines, so that implementation of childhood immunization is justified. The study was done in the Province of Vojvodina but the findings may be applied to Serbia as a whole. [Projekat Ministarstva nauke Republike Srbije, br. ON 175039] This article has been corrected. Link to the correction 10.2298/SARH

  3. Detection of dengue virus serotypes 1, 2 and 3 in selected regions of Kenya: 2011-2014.

    Science.gov (United States)

    Konongoi, Limbaso; Ofula, Victor; Nyunja, Albert; Owaka, Samuel; Koka, Hellen; Makio, Albina; Koskei, Edith; Eyase, Fredrick; Langat, Daniel; Schoepp, Randal J; Rossi, Cynthia Ann; Njeru, Ian; Coldren, Rodney; Sang, Rosemary

    2016-11-04

    Dengue fever, a mosquito-borne disease, is associated with illness of varying severity in countries in the tropics and sub tropics. Dengue cases continue to be detected more frequently and its geographic range continues to expand. We report the largest documented laboratory confirmed circulation of dengue virus in parts of Kenya since 1982. From September 2011 to December 2014, 868 samples from febrile patients were received from hospitals in Nairobi, northern and coastal Kenya. The immunoglobulin M enzyme linked immunosorbent assay (IgM ELISA) was used to test for the presence of IgM antibodies against dengue, yellow fever, West Nile and Zika. Reverse transcription polymerase chain reaction (RT-PCR) utilizing flavivirus family, yellow fever, West Nile, consensus and sero type dengue primers were used to detect acute arbovirus infections and determine the infecting serotypes. Representative samples of PCR positive samples for each of the three dengue serotypes detected were sequenced to confirm circulation of the various dengue serotypes. Forty percent (345/868) of the samples tested positive for dengue by either IgM ELISA (14.6 %) or by RT-PCR (25.1 %). Three dengue serotypes 1-3 (DENV1-3) were detected by serotype specific RT-PCR and sequencing with their numbers varying from year to year and by region. The overall predominant serotype detected from 2011-2014 was DENV1 accounting for 44 % (96/218) of all the serotypes detected, followed by DENV2 accounting for 38.5 % (84/218) and then DENV3 which accounted for 17.4 % (38/218). Yellow fever, West Nile and Zika was not detected in any of the samples tested. From 2011-2014 serotypes 1, 2 and 3 were detected in the Northern and Coastal parts of Kenya. This confirmed the occurrence of cases and active circulation of dengue in parts of Kenya. These results have documented three circulating serotypes and highlight the need for the establishment of active dengue surveillance to continuously detect cases, circulating

  4. Changing trends in serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae causing invasive diseases in Central Thailand, 2009-2012.

    Science.gov (United States)

    Phongsamart, Wanatpreeya; Srifeungfung, Somporn; Chatsuwan, Tanittha; Nunthapisud, Pongpun; Treerauthaweeraphong, Vipa; Rungnobhakhun, Pimpha; Sricharoenchai, Sirintip; Chokephaibulkit, Kulkanya

    2014-01-01

    To describe the trends in serotype distribution and antimicrobial susceptibility of S. pneumoniae causing invasive pneumococcal diseases (IPD) we tested 238 pneumococci isolates from normally sterile sites between 2009 and 2012 and compared these findings with previous data collected within our network. Serotyping was performed for 15 serotypes contained in the 7-,10-, 13-, and experimental 15-valent pneumococcal conjugate vaccines (PCV). The most common serotypes found were 6B (13.9%), 19A (12.6%), 14 (8.0%), 18C (5.9%), and 6A (3.8%); and 39.9% were non-PCV15 serotypes. One of 81 patients with available data had breakthrough infection with vaccine serotype (19F). There was a significant increase of serotype 19A among children ≤5 years (5.6% in 2000-2009 vs 18.3% in 2009-2012, P = 0.003). The all-age serotype coverage was 36.4%, 41.5%, 59.3%, and 59.7% for PCV7, PCV10, PCV13, and PCV 15, respectively. The corresponding coverage in children ≤5 years were 46.4%, 48.8%, 73.2%, and 73.2% respectively. High susceptibilities to penicillin (89.7%), cefotaxime (95.7%), cefditoren (90.2% by Spanish breakpoints), ofloxacin (97.9%), and levofloxacin (100%), but low to cefdinir (50.0%), cefditoren (45.1% by US-FDA breakpoints), macrolides (<50%), clindamycin (67.7%), tetracycline (41.4%), and trimethoprim-sulfamethoxazole (32.4%) were observed. Serotype 19A was less susceptible to penicillin (80.0 vs 91.2%, P = 0.046), cefditoren (66.7 vs 95.5% by Spanish breakpoints, P = 0.004), and tetracycline (9.1 vs 45.5%, P = 0.024) than non-19A isolates. These data emphasize the need for continued surveillance to monitor changes in serotypes as well as antimicrobial susceptibilities in order to guide strategies for prevention and treatment.

  5. Development and evaluation of a mixed long-chain lipopolysaccharide based ELISA for serological surveillance of infection with Actinobacillus pleuropneumoniae serotypes 2, 6 and 12 in pig herds

    DEFF Research Database (Denmark)

    Grøndahl-Hansen, Jan; Barfod, Kristen; Klausen, Joan;

    2003-01-01

    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...... 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......, 5b, 6, 7, 8, 10 and 12 of Ap biotype 1. In addition to reaction with sera from pigs inoculated with Ap serotypes 2, 6 and 12, reaction was observed with sera from pigs inoculated with serotype 8. Furthermore, the sensitivity and specificity of the test on a herd level were evaluated with sera from...

  6. Serotype Distribution, Antibiotic Resistance and Clonality of Streptococcus pneumoniae Isolated from Immunocompromised Patients in Tunisia.

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    Anis Raddaoui

    Full Text Available Pneumococcal disease, a major cause of morbidity and mortality globally, has higher incidence among young children, the elderly and the immunocompromised of all ages. In Tunisia, pneumococcal conjugate vaccines (PCVs are not included in the national immunization program. Also, few studies have described the epidemiology of S. pneumoniae in this country and, in particular, no molecular typing studies have been performed. The aim of this study was to evaluate serotype distribution, antimicrobial resistance and clonality of Streptococcus pneumoniae isolated from neutropenic patients in Tunisia.Fifty-nine S. pneumoniae were isolated from infection (n = 31 and colonization (n = 28 sites of patients (children and adults attending the National Centre of Bone Marrow Transplantation in Tunis between 2005-2011. All isolates were characterized by serotype, antimicrobial resistance pattern and multilocus sequence typing (MLST.The majority (66.1% of the isolates belonged to five serotypes all included in PCVs: 6B, 9V, 14, 19F and 23F. The potential coverage of the 10-valent and 13-valent PCV was of 71.2% and 76.3% respectively. Resistance rates were very high and 69.5% of the isolates were multidrug resistant: non-susceptibility rates to penicillin, amoxicillin and cefotaxime were 66.1%, 40.7% and 27.1%, respectively; resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole, were 69.5%, 61.0%, 37.3%, 22.0% and 67.8%, respectively. The most frequent serotypes had STs characteristic of multidrug resistant international clones known to be highly successful and important causes of pneumococcal infection: Spain 23F-ST81, France 9V/14-ST156, Spain 6B-ST90, 19F-ST320, and Portugal 19F-ST177.The majority of S. pneumoniae strains recovered from immunocompromised patients in Tunisia are representatives of multidrug resistant pandemic clones that express serotypes targeted by PCVs. To contain the burden of

  7. Serotype Distribution, Antimicrobial Susceptibility, and Molecular Epidemiology of Streptococcus pneumoniae Isolated from Children in Shanghai, China.

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    Fen Pan

    Full Text Available Streptococcus pneumoniae is a common pathogenic cause of pediatric infections. This study investigated the serotype distribution, antimicrobial susceptibility, and molecular epidemiology of pneumococci before the introduction of conjugate vaccines in Shanghai, China.A total of 284 clinical pneumococcal isolates (270, 5, 4,3, and 2 of which were isolated from sputum, bronchoalveolar lavage fluid, blood, cerebral spinal fluid, and ear secretions, respectively from children less than 14 years of age who had not been vaccinated with a conjugate vaccine, were collected between January and December in 2013. All isolates were serotyped by multiplex polymerase chain reaction or quellung reactions and antimicrobial susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S.pneumoniae was analyzed by multilocus sequence typing (MLST.Among the 284 pneumococcal isolates, 19F (33.5%, 19A (14.1%, 23F (12.0%, and 6A (8.8% were the most common serotypes and the coverage rates of the 7-, 10-, and 13-valent pneumococcal conjugate vaccines (PCV7, PCV10, and PCV13 were 58.6%, 59.4% and 85.1%, respectively. Antimicrobial susceptibility showed that the prevalence rates of S.pneumoniae resistance to penicillin were 11.3% (32/284. Approximately 88.0% (250/284 of the isolates exhibited multi-drug resistance. MLST analysis revealed a high level of diversity, with 65 sequence types (STs among 267 isolates. Specifically, the four predominant STs were ST271 (24.3%, 65/267, ST320 (11.2%, 30/267, ST81 (9.7%, 26/267, and ST3173 (5.2%, 14/267, which were mainly associated with serotypes 19F, 19A, 23F, and 6A, respectively.The prevalent serotypes among clinical isolates from children were 19F, 19A, 23F, and 6A and these isolates showed high resistance rates to β-lactams and macrolides. The Taiwan19F-14 clone played a predominant role in the dissemination of pneumococcal isolates in Shanghai, China. Therefore, continued and

  8. Dengue virus antibody database: Systematically linking serotype-specificity with epitope mapping in dengue virus

    Science.gov (United States)

    Chaudhury, Sidhartha; Gromowski, Gregory D.; Ripoll, Daniel R.; Khavrutskii, Ilja V.; Desai, Valmik; Wallqvist, Anders

    2017-01-01

    Background A majority infections caused by dengue virus (DENV) are asymptomatic, but a higher incidence of severe illness, such as dengue hemorrhagic fever, is associated with secondary infections, suggesting that pre-existing immunity plays a central role in dengue pathogenesis. Primary infections are typically associated with a largely serotype-specific antibody response, while secondary infections show a shift to a broadly cross-reactive antibody response. Methods/Principal findings We hypothesized that the basis for the shift in serotype-specificity between primary and secondary infections can be found in a change in the antibody fine-specificity. To investigate the link between epitope- and serotype-specificity, we assembled the Dengue Virus Antibody Database, an online repository containing over 400 DENV-specific mAbs, each annotated with information on 1) its origin, including the immunogen, host immune history, and selection methods, 2) binding/neutralization data against all four DENV serotypes, and 3) epitope mapping at the domain or residue level to the DENV E protein. We combined epitope mapping and activity information to determine a residue-level index of epitope propensity and cross-reactivity and generated detailed composite epitope maps of primary and secondary antibody responses. We found differing patterns of epitope-specificity between primary and secondary infections, where secondary responses target a distinct subset of epitopes found in the primary response. We found that secondary infections were marked with an enhanced response to cross-reactive epitopes, such as the fusion-loop and E-dimer region, as well as increased cross-reactivity in what are typically more serotype-specific epitope regions, such as the domain I-II interface and domain III. Conclusions/Significance Our results support the theory that pre-existing cross-reactive memory B cells form the basis for the secondary antibody response, resulting in a broadening of the response

  9. Salmonella fecal shedding and immune responses are dose- and serotype- dependent in pigs.

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    Renata Ivanek

    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

  10. Serotype-related differences in production and type of heat-labile hemolysin and heat-labile cytotoxin of Actinobacillus (Haemophilus) pleuropneumoniae.

    OpenAIRE

    Kamp, E M; van Leengoed, L A

    1989-01-01

    Reference strains of serotypes 1 to 12 of Actinobacillus (Haemophilus) pleuropneumoniae were cultured in Eagle minimal essential medium with 10% Serum Plus. Culture supernatants were examined for cytotoxicity to alveolar macrophages and for the ability to hemolyze sheep erythrocytes. All strains except the reference strain of serotype 6 produced cytotoxin, whereas only serotypes 1, 5, 9, 10, and 11 produced hemolysin. Both cytotoxin and hemolysin appeared to be heat labile. Antisera were rais...

  11. Features of a clinical course of the acute respiratory diseases caused by adenoviruses of epidemic significant serotypes

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    N. I. L`vov

    2014-01-01

    Full Text Available The objective: To investigate etiological structure of adenoviral diseases in young people from organized groups and the clinical features of acute respiratory disease caused by different serotypes of adenovirus were identified.Materials and methods: A total 382 patients with adenovirusinfections were investigated. Virus isolation from nasopharyngeal swabs was carried out in cell cultures Vero, HeLa, Hep-2. Typing of adenoviruses was performed by virus neutralization test with polyclonal rabbit subtype specific sera. The average (M, standard deviation (SD and frequency of occurrence (% of clinical signs (respiratory and non-respiratory syndromes of pneumonia, protracted and recurrent course was calculated. Significance of the differences (p<0,05 of average frequency of cases compared to independent group of patients was evaluated by Student t-test and criterion φ2 (phi – square Fischer, respectively.Results: As result of investigation 199 adenovirus strains (52,1 % were isolated. 183 strains were serotyped: 64 (32,2 % – 3 serotype, 42 (21,1 % – 4 serotype, 38 (19,1 % – 7 serotype, 15 (7,5 % – 5 serotype, 11 (5,5 % – 21 serotype, 8 (4,0 % – 1 serotype, 3 (1,5 % – 2 serotype, 2 (1,0 % – 6 serotype. In assessing the features of the clinical course of adenoviral infection caused by the most actual serotypes (3, 4, 7 of adenovirus revealed that duration of diseases caused by serotype 7 was significantly longer and remained febrile fever (4,3±2,74 days, p<0,05, rhinitis (9,4±6,01 days, p<0,05, pharyngitis (7,9±2,87 days, p<0,05, laryngitis (7,3±2,87 days, p<0,05 and bronchitis (11,8±8,03 days, p<0,05, tonsillitis (63,0%, φ2=12,6, p<0,05, lymphadenopathy (63,0%, φ2=4,1, p<0,05, and pneumonia (34,2%, φ2=3,84, p<0,05 were registered significantly more frequently.Conclusion: The study showed that the adenoviruses of 3, 4 and 7 serotype have the greatest epidemiological significance. Clinical features

  12. [Emergence of invasive pneumococcal disease caused by non-vaccine serotypes in the era of the 7-valent conjugate vaccine].

    Science.gov (United States)

    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

    2014-03-01

    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.

  13. Streptococcus agalactiae isolates of serotypes Ia, III and V from human and cow are able to infect tilapia.

    Science.gov (United States)

    Chen, Ming; Wang, Rui; Luo, Fu-Guang; Huang, Yan; Liang, Wan-Wen; Huang, Ting; Lei, Ai-Ying; Gan, Xi; Li, Li-Ping

    2015-10-22

    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.

  14. Slaughterhouse pigs are a major reservoir of Streptococcus suis serotype 2 capable of causing human infection in southern Vietnam.

    Directory of Open Access Journals (Sweden)

    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.

  15. A comparison of cecal colonization of Salmonella enterica serotype Typhimurium in white leghorn chicks and Salmonella-resistant mice

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    Bogomolnaya Lydia M

    2008-10-01

    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.

  16. Role of RpoS in fine-tuning the synthesis of Vi capsular polysaccharide in Salmonella enterica serotype Typhi.

    Science.gov (United States)

    Santander, Javier; Wanda, Soo-Young; Nickerson, Cheryl A; Curtiss, Roy

    2007-03-01

    Regulation of the synthesis of Vi polysaccharide, a major virulence determinant in Salmonella enterica serotype Typhi, is under the control of two regulatory systems, ompR-envZ and rscB-rscC, which respond to changes in osmolarity. Some serotype Typhi strains exhibit overexpression of Vi polysaccharide, which masks clinical detection of lipopolysaccharide O antigen. This variation in Vi polysaccharide and O antigen display (VW variation) has been observed since the initial studies of serotype Typhi. In this study, we report that rpoS plays a role in this increased expression in Vi polysaccharide. We constructed a variety of isogenic serotype Typhi mutants that differed in their expression levels of RpoS and examined the role of the rpoS product in synthesis of Vi polysaccharide under different osmolarity conditions. Vi polysaccharide synthesis was also examined in serotype Typhi mutants in which the native promoter of the rpoS was replaced by an araCP(BAD) cassette, so that the expression of rpoS was arabinose dependent. The RpoS(-) strains showed increased syntheses of Vi polysaccharide, which at low and medium osmolarities masked O antigen detection. In contrast, RpoS(+) strains showed lower syntheses of Vi polysaccharide, and an increased detection of O antigen was observed. During exponential growth, when rpoS is unstable or present at low levels, serotype Typhi RpoS(+) strains overexpress the Vi polysaccharide at levels comparable to those for RpoS(-) strains. Our results show that RpoS is another regulator of Vi polysaccharide synthesis and contributes to VW variation in serotype Typhi, which has implications for the development of recombinant attenuated Salmonella vaccines in humans.

  17. Experimental infection of one-day-old chicks with Salmonella Serotypes Previously isolated from poultry facilities, wild birds, and swine

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    E de Sousa

    2013-12-01

    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.

  18. Mannheimia haemolytica serotype A1 exhibits differential pathogenicity in two related species, Ovis canadensis and Ovis aries.

    Science.gov (United States)

    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

    2009-02-02

    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.

  19. Development and Evaluation of a Rapid Antigen Detection and Serotyping Lateral Flow Antigen Detection System for Foot-and-Mouth Disease Virus.

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    Kazuki Morioka

    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.

  20. Evaluation of an enzyme-linked immunosorbent assay for serological surveillance of infection with Actinobacillus pleuropneumoniae serotype 5 in pig herds

    DEFF Research Database (Denmark)

    Klausen, Joan; Andresen, Lars Ole; Barfod, Kristen;

    2002-01-01

    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...... showed that the antigen contained high molecular weight lipopolysaccharide (LPS) and presumably also capsular polysaccharide (CP). The Ap serotype 5 ELISA was tested using sera from pigs experimentally infected with the 12 different Ap serotypes of biotype 1 and with sera from herds naturally infected...

  1. High nasopharyngeal carriage of non-vaccine serotypes in Western Australian aboriginal people following 10 years of pneumococcal conjugate vaccination.

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    Deirdre A Collins

    Full Text Available BACKGROUND: Invasive pneumococcal disease (IPD continues to occur at high rates among Australian Aboriginal people. The seven-valent pneumococcal conjugate vaccine (7vPCV was given in a 2-4-6-month schedule from 2001, with a 23-valent pneumococcal polysaccharide vaccine (23vPPV booster at 18 months, and replaced with 13vPCV in July 2011. Since carriage surveillance can supplement IPD surveillance, we have monitored pneumococcal carriage in western Australia (WA since 2008 to assess the impact of the 10-year 7vPCV program. METHODS: We collected 1,500 nasopharyngeal specimens from Aboriginal people living in varied regions of WA from August 2008 until June 2011. Specimens were cultured on selective media. Pneumococcal isolates were serotyped by the quellung reaction. RESULTS: Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were carried by 71.9%, 63.2% and 63.3% respectively of children <5 years of age, and 34.6%, 22.4% and 27.2% of people ≥5 years. Of 43 pneumococcal serotypes identified, the most common were 19A, 16F and 6C in children <5 years, and 15B, 34 and 22F in older people. 7vPCV serotypes accounted for 14.5% of all serotypeable isolates, 13vPCV for 32.4% and 23vPPV for 49.9%, with little variation across all age groups. Serotypes 1 and 12F were rarely identified, despite causing recent IPD outbreaks in WA. Complete penicillin resistance (MIC ≥2µg/ml was found in 1.6% of serotype 19A (5.2%, 19F (4.9% and 16F (3.2% isolates and reduced penicillin susceptibility (MIC ≥0.125µg/ml in 24.9% of isolates, particularly 19F (92.7%, 19A (41.3%, 16F (29.0%. Multi-resistance to cotrimoxazole, tetracycline and erythromycin was found in 83.0% of 23F isolates. Among non-serotypeable isolates 76.0% had reduced susceptibility and 4.0% showed complete resistance to penicillin. CONCLUSIONS: Ten years after introduction of 7vPCV for Aboriginal Australian children, 7vPCV serotypes account for a small proportion of carried

  2. Effects of Infant Pneumococcal Conjugate Vaccination on Serotype Distribution in Invasive Pneumococcal Disease among Children and Adults in Germany.

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    van der Linden, Mark; Falkenhorst, Gerhard; Perniciaro, Stephanie; Imöhl, Matthias

    2015-01-01

    This study describes the effects of the introduction of universal infant pneumococcal conjugate vaccination in 2006 on invasive pneumococcal disease (IPD) among children and adults in Germany with a focus on the dynamics of serotype distribution in vaccinated and non-vaccinated age groups. Over a period of 22 years (1992-2014), microbiological diagnostic laboratories from all over Germany have been sending isolates of IPD cases to the German National Reference Center for Streptococci on a voluntary basis. Streptococcus pneumoniae isolates were serotyped using Neufeld's Quellung method. Among children vaccination (1997-2006) to 23.5% in the early vaccination period (2007-2010; p = 1.30E-72) and sank further to 5.2% in the late vaccination period (2010-2014; p = 4.59E-25). Similar reductions were seen for the separate age groups vaccination period (1992-2006) to 24.7% (p = 3.78E-88) in the early vaccination period and 8.2% (p = 5.97E-161) in the late vaccination period. Both among children and among adults, the non-PCV7 serotypes 1, 3, 7F and 19A significantly increased in the early vaccination period. After the switch from PCV7 to PVC10/PCV13 for infant vaccination in 2010, serotypes 1, 6A and 7F significantly decreased. A decrease in serotype 19A was only observed in 2013-2014, as compared to 2010-2011 (children p = 4.16E-04, adults p = 6.98E-06). Among adults, serotype 3, which strongly increased in the early vaccination period (p = 4.44E-15), remained at a constant proportion in the late vaccination period. The proportion of non-PCV13 vaccine serotypes increased over the whole vaccination period, with serotypes 10A, 12F, 23B, 24F and 38 most significantly increasing among children and serotypes 6C, 12F, 15A, 22F and 23B increasing among adults. Eight years of childhood pneumococcal conjugate vaccination have had a strong effect on the pneumococcal population in Germany, both among the target group for vaccination as well as among older children and adults.

  3. Validation of an immunodiagnostic assay for detection of 13 Streptococcus pneumoniae serotype-specific polysaccharides in human urine.

    Science.gov (United States)

    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

    2012-08-01

    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.

  4. Nasopharyngeal Carriage, Capsular and Molecular Serotyping and Antimicrobial Susceptibility of Streptococcus pneumoniae among Asymptomatic Healthy Children in Egypt.

    Science.gov (United States)

    El-Nawawy, Ahmed A; Hafez, Soad F; Meheissen, Marwa A; Shahtout, Nehal M; Mohammed, Essam E

    2015-12-01

    Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide with increasing antimicrobial resistance. 600 randomly chosen asymptomatic healthy children aged 2-60 months attending Alexandria University Children's Hospital were evaluated for prevalence of nasopharyngeal (NP) carriage of S. pneumoniae. Prevalence of NP carriage was 29.2% (n = 175/600) Capsular serotyping was done using Quellung reaction. Vaccine covered serotypes (VST) represented 67.4% while non-vaccine serotypes (NVST) were 32.6%. The most common VST isolated were 19F (24.6%), 6B (14.3%) and 6A (10.9%). Confirmation of serotyping was performed by multiplex PCR which showed 100% concordance with the Quellung reaction. Antimicrobial susceptibility testing showed penicillin non-susceptibility of 15% (using non-meningitis penicillin MIC breakpoints) and 55% (using meningitis penicillin MIC breakpoints). Highest resistance was found in sulphamethoxazole-trimethoprim (55%), tetracyclins (49%), erythromycin (40%) and clindamycin (25%). This study revealed the epidemiological importance to evaluate regularly the prevalence, serotypes and the increasing antimicrobial resistance of S. pneumoniae in the community.

  5. Multiplexed Lateral Flow Test for Detection and Differentiation of Cronobacter sakazakii Serotypes O1 and O2

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    Eva J. Scharinger

    2017-09-01

    Full Text Available The ubiquitous and opportunistic pathogen Cronobacter sakazakii is responsible for severe meningitis, sepsis, and necrotizing enterocolitis in neonates and infants associated with ingestion of contaminated powdered infant formula (PIF. The current ISO method for isolation and detection of Cronobacter spp. is laborious, time-consuming and expensive. In this study, a multiplexed lateral flow test strip was developed to rapidly detect and simultaneously serotype O1 and O2 C. sakazakii serotypes. The assay is based on two monoclonal antibodies (MAb that specifically bind to the lipopolysaccharides (LPS of these pathogens. The test strip provides results very quickly; C. sakazakii could be detected in pure culture within 15 min with a sensitivity of 107 CFU/ml. After non-selective enrichment for 18 h as low as one Cronobacter cell per g PIF could be detected. Moreover, the established lateral flow assay (LFA offers excellent specificity showing no cross-reactivity with other C. sakazakii serotypes, Cronobacter species or Enterobacteriaceae tested. These characteristics, together with several advantages such as speed, simplicity in performance, low analysis cost, and no requirement of specialized skills or sophisticated equipment make the developed multiplexed LFA suitable for reliable detection and serotyping of C. sakazakii serotypes O1 and O2.

  6. Serotype Distribution and Demographics of Dengue Patients in a Tertiary Hospital of Lahore, Pakistan during the 2011 Epidemic

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    Muhammad MUNIR

    2013-06-01

    Full Text Available The dengue outbreak in Lahore, Pakistan during 2011 was unprecedented in terms of its severity and magnitude. This research aims to determine the serotype distribution of the dengue virus during this outbreak and classify the patients demographically. 5ml of venous blood was drawn aseptically from 166 patients with dengue like signs to test for the virus between the months of August to November 2011. The samples were sent to CDC, Atlanta, Georgia for the purpose of molecular assays to determine their serotype. RT-PCR protocol was performed targeting the 4 dengue serotypes. Out of 166 cases, dengue infection was detected with RT-PCR in 95 cases, all infected with the same serotype DEN-2. 75 % of positive cases were males while 25 % were females. Most positive patients were in the age range of 16 - 30 years. 33 % positive cases had accompanying bleeding. This is first study during the 2011 dengue epidemic in Lahore that reports DEN-2 as the only prevalent serotype. It also indicates that more infected patients were males, adults, within the age range of 16 - 30 years, the epidemic peaked in the month of November, Dengue hemorrhagic fever (DHF is manifested more in females, and that Ravi town was heavily hit by the dengue virus infection.

  7. Dengue serotype cross-reactive, anti-E protein antibodies confound specific immune memory for one year after infection

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    Ying Xiu eToh

    2014-08-01

    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.

  8. Assessment of tropism and effectiveness of new primate-derived hybrid recombinant AAV serotypes in the mouse and primate retina.

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    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.

  9. O-antigen structure of Shigella flexneri serotype Yv and effect of the lpt-O gene variation on phosphoethanolamine modification of S. flexneri O-antigens.

    Science.gov (United States)

    Knirel, Yuriy A; Lan, Ruiting; Senchenkova, Sof'ya N; Wang, Jianping; Shashkov, Alexander S; Wang, Yan; Perepelov, Andrei V; Xiong, Yanwen; Xu, Jianguo; Sun, Qiangzheng

    2013-04-01

    Shigella flexneri is the major human pathogen causing shigellosis. O-antigens of all S. flexneri serotypes (except for serotype 6) share the →2)-α-l-Rhap(III)-(1 → 2)-α-l-Rhap(II)-(1 → 3)-α-l-Rhap(I)-(1 → 3)-β-d-GlcpNAc-(1→ basic O-unit, whereas differences between the serotypes are conferred by phage-encoded glucosylation and/or O-acetylation at various positions. Recently, in serotype X and 4a variants called Xv and 4av, respectively, O-antigen modification with phosphoethanolamine (PEtN) has been identified, which is encoded by a plasmid-borne gene (lpt-O) for a PEtN-transferase and confers the monoclonal antibody IV-1(MASF IV-1) determinant to the bacteria. In this study, we elucidated the O-antigen structure of serotype Yv, another MASF IV-1-positive novel variant of S. flexneri. The serotype Yv O-antigen has the same basic carbohydrate backbone structure as that of the "classical" serotype Y, but differs in the presence of PEtN at position 3 of Rha(III) (major) or both Rha(II) and Rha(III) (minor). This pattern is similar to that of serotype 4av, but different from the pattern of serotype Xv, which is characterized by major PEtN modification on Rha(II). In serotype Yv, mono- and bisphosphorylated O-units generate a block-copolymeric structure, the former being partially O-acetylated at position 6 of GlcNAc and the latter lacking O-acetylation. Functional analysis revealed a correlation between the serotype-specific PEtN modification pattern and the lpt-O variation in different serotypes: lpt-O(RII) in serotype Xv is better tuned for phosphorylation of Rha(II) and lpt-O(RIII) in serotypes Yv and 4av for phosphorylation of Rha(III). These data enhance our knowledge of S. flexneri serotype conversion mechanisms and help to understand the biosynthesis process of the new O-antigen variants.

  10. Antimicrobial susceptibility profiles, serotype distribution and virulence determinants among invasive, non-invasive and colonizing Streptococcus agalactiae (group B streptococcus) from Malaysian patients.

    Science.gov (United States)

    Eskandarian, N; Ismail, Z; Neela, V; van Belkum, A; Desa, M N M; Amin Nordin, S

    2015-03-01

    A total of 103 group B streptococci (GBS) including 22 invasive, 21 non-invasive, and 60 colonizing isolates were collected in a Malaysian hospital (June 2010-October 2011). Isolates were characterized by conventional and molecular serotyping and analyzed for scpB, lmb, hylB, cylE, bac, bca and rib gene content. Antimicrobial susceptibility to penicillins, macrolides, lincosamides, quinolones and tetracyclines was determined using disk diffusion and the MICs for penicillin were determined by E-test. Molecular serotyping for all eight serotypes (Ia, Ib, II-VII) was in full accordance with conventional serotyping. Overall, taking CS and MS together, serotype VI was the most common capsular type (22.3 %) followed by VII (21.4 %), III (20.4 %), Ia (17.5 %), V (9.7 %), II (7.7 %) and IV (1 %). Susceptibility to beta-lactam antimicrobials was prevalent (100 %). Resistance rates for erythromycin, clindamycin and tetracycline were 23.3 %, 17.5 % and 71.8 %, respectively. PCR-virulence gene screening showed the presence of cylE, lmb, scpB and hylB in almost all the isolates while rib, bca, and bac genes were found in 29.1 %, 14.6 % and 9.7 % of the isolates. Certain genes were significantly associated with specific serotypes, namely, rib with serotypes Ia, II, III and VI; bca and bac with serotypes II and III. Furthermore, serotype Ia was significantly more common among patients with invasive infections (p < 0.01) and serotype VI isolates were significantly more common among carriers (p < 0.05). In summary, serotype distribution correlates with virulence gene content will be useful in epidemiological studies and design of vaccines.

  11. Streptococcus pneumoniae serotype 19A in Latin America and the Caribbean: a systematic review and meta-analysis, 1990–2010

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    Castañeda Elizabeth

    2012-05-01

    Full Text Available Abstract Background Pneumococcal conjugate vaccines (PCVs are in the process of implementation in Latin America. Experience in developed countries has shown that they reduce the incidence of invasive and non-invasive disease. However, there is evidence that the introduction of PCVs in universal mass vaccination programs, combined with inappropriate and extensive use of antibiotics, could be associated to changes in non-PCV serotypes, including serotype 19A. We conducted a systematic review to determine the distribution of serotype 19A, burden of pneumococcal disease and antibiotic resistance in the region. Methods We performed a systematic review of serotype 19A data from observational and randomized clinical studies in the region, conducted between 1990 and 2010, for children under 6 years. Pooled prevalence estimates from surveillance activities with confidence intervals were calculated. Results We included 100 studies in 22 countries and extracted data from 63. These data reported 19733 serotyped invasive pneumococcal isolates, 3.8% of which were serotype 19A. Serotype 19A isolates were responsible for 2.4% acute otitis media episodes, and accounted for 4.1% and 4.4% of 4,380 nasopharyngeal isolates from healthy children and in hospital-based/sick children, respectively. This serotype was stable over the twenty years of surveillance in the region. A total of 53.7% Spn19A isolates from meningitis cases and only 14% from non meningitis were resistant to penicillin. Conclusions Before widespread PCV implementation in this region, serotype 19A was responsible for a relatively small number of pneumococcal disease cases. With increased use of PCVs and a greater number of serotypes included, monitoring S. pneumoniae serotype distribution will be essential for understanding the epidemiology of pneumococcal disease.

  12. Role of cellular heparan sulfate proteoglycans in infection of human adenovirus serotype 3 and 35.

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    Sebastian Tuve

    2008-10-01

    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.

  13. Serotype-Specific Structural Differences in the Protease-Cofactor Complexes of the Dengue Virus Family

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    Chandramouli, Sumana; Joseph, Jeremiah S.; Daudenarde, Sophie; Gatchalian, Jovylyn; Cornillez-Ty, Cromwell; Kuhn, Peter (Scripps)

    2010-03-04

    With an estimated 40% of the world population at risk, dengue poses a significant threat to human health, especially in tropical and subtropical regions. Preventative and curative efforts, such as vaccine development and drug discovery, face additional challenges due to the occurrence of four antigenically distinct serotypes of the causative dengue virus (DEN1 to -4). Complex immune responses resulting from repeat assaults by the different serotypes necessitate simultaneous targeting of all forms of the virus. One of the promising targets for drug development is the highly conserved two-component viral protease NS2B-NS3, which plays an essential role in viral replication by processing the viral precursor polyprotein into functional proteins. In this paper, we report the 2.1-{angstrom} crystal structure of the DEN1 NS2B hydrophilic core (residues 49 to 95) in complex with the NS3 protease domain (residues 1 to 186) carrying an internal deletion in the N terminus (residues 11 to 20). While the overall folds within the protease core are similar to those of DEN2 and DEN4 proteases, the conformation of the cofactor NS2B is dramatically different from those of other flaviviral apoprotease structures. The differences are especially apparent within its C-terminal region, implicated in substrate binding. The structure reveals for the first time serotype-specific structural elements in the dengue virus family, with the reported alternate conformation resulting from a unique metal-binding site within the DEN1 sequence. We also report the identification of a 10-residue stretch within NS3pro that separates the substrate-binding function from the catalytic turnover rate of the enzyme. Implications for broad-spectrum drug discovery are discussed.

  14. Invasive isolates of Streptococcus pneumoniae in Serbia: Antimicrobial susceptibility and serotypes

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    Gajić Ina

    2013-01-01

    Full Text Available Introduction. Streptococcus pneumoniae is one of the leading causes of bacterial meningitis and sepsis. Invasive pneumococcal disease is a significant medical problem worldwide, particularly in children, due to a huge increase of pneumococcal resistance to antibiotics. Objective. The aim of the study was to investigate the antimicrobial susceptibility pattern of invasive pneumococcal isolates, as well as to determine whether decreased S. pneumoniae susceptibility to antibiotics was related to a particular serotype. Methods. Antimicrobial susceptibility to 19 antibiotics was determined in 58 invasive pneumococcal strains that were collected from seven regional centers during the period July 2009 to February 2011 in the National Reference Laboratory for streptococci and pneumococci. Results. The overall nonsusceptibility rate to penicillin was detected in 34% of pneumococcal isolates and to erythromycin in 36%. Higher resistance rates were observed among children than among adults. Penicillin resistance rate was 65% in children versus 22% in adults, while erythromycin nonsusceptibility rate was 47% in children versus 32% in adults. Co-resistance to penicillin and erythromycin was detected in 21% strains, mostly isolated from children. Multiresistance was found in one third of isolates. All strains were susceptible to vancomycin, linezolid, fluoroquinolones, telithromycin and rifampicin, while 23 (40% isolates were susceptible to all tested antibiotics. The most common resistant serotypes were 19F and 14. Conclusion. The study has revealed that penicillin and macrolide resistance among invasive pneumococcal isolates is very high in Serbia. This emphasizes the need for continuous monitoring for invasive pneumococcal disease to document the serotype distribution and antimicrobial susceptibility pattern. [Projekat Ministarstva nauke Republike Srbije, br. 175039: Bakterije rezistentne na antibiotike u Srbiji - fenotipska i genotipska karakterizacija

  15. Multidrug Resistance in Non-PCV13 Serotypes of Streptococcus pneumoniae in Northern Japan, 2014.

    Science.gov (United States)

    Kawaguchiya, Mitsuyo; Urushibara, Noriko; Kobayashi, Nobumichi

    2017-03-01

    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 T371S in the STMK motif and TSQF574-577NTGY 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.

  16. Transmission dynamics of the four dengue serotypes in southern Vietnam and the potential impact of vaccination.

    Directory of Open Access Journals (Sweden)

    Laurent Coudeville

    Full Text Available BACKGROUND: With approximately 2.5 billion people at risk, dengue is a major international public health concern. Dengue vaccines currently in development should help reduce the burden associated with this disease but the most efficient way of using future dengue vaccines remains to be defined. Mathematical models of transmission can provide insight into the expected impact of different vaccination strategies at a population level and contribute to this definition. METHODS AND FINDINGS: We developed and analyzed an age-structured, host-vector and serotype-specific compartmental model, including seasonality. We first used this transmission model to identify the immunological interactions between serotypes that affect the risks and consequences of secondary infections (cross-protection, increased susceptibility, increased severity, and increased infectiousness and reproduce the observed epidemiology of dengue. For populating this model, we used routine surveillance data from Southern Vietnam and the results of a prospective cohort study conducted in the same area. The model provided a good fit to the observed data for age, severity of cases, serotype distribution, and dynamics over time, using two scenarios of immunological interaction : short term cross-protection alone (6-17 months or a combination of short term cross-protection with cross-enhancement (increased susceptibility, severity and infectiousness in the case of secondary infections. Finally, we explored the potential impact of vaccination for these two scenarios. Both highlighted that vaccination can substantially decrease dengue burden by reducing the magnitude and frequency of outbreaks. CONCLUSION: Our model suggests that seasonality and short term cross-protection are key factors for explaining dengue dynamics in Southern Vietnam. Vaccination was predicted to significantly reduce the disease burden, even in the situation where immunological cross-enhancement affects the risks and

  17. Serotypes and Antimicrobial Susceptibility of Salmonella spp. Isolated from Farm Animals in China

    Directory of Open Access Journals (Sweden)

    Yuan Zong Hui

    2015-06-01

    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

  18. The human rhinovirus internal cis-acting replication element (cre) exhibits disparate properties among serotypes.

    Science.gov (United States)

    McKnight, K L

    2003-12-01

    It has been reported previously that the Human rhinovirus 14 (HRV-14) RNA genome contains a cis-acting replication element (cre) that maps to the capsid coding (P1) sequence [19]. Further characterization of the HRV-14 cre in the present study established that by moving the cre stem-loop structure downstream, adjacent to the 3'NCR, that its position is not critical for function. When the P1 sequences of two closely related serotypes of HRV-14 were analyzed for the presence of a cre, both HRV-3 and HRV-72 were found to contain similar sequence at the same positions as HRV-14. Moreover, sequence at these positions produced structures from MFOLD analysis that closely resembled the HRV-14 cre. It was also discovered that neither HRV serotypes 1a or 16 harbor replication elements that map to the P1 segments of their genomes. Computer and mutational analyses suggest that the cre in these latter HRV serotypes map instead to the 2A gene, as has been reported for HRV-2. The putative HRV-3 cre was determined to be unable to support replication when placed in an HRV-14 replicon background. Similarly, the previously identified HRV-2 cre was unable to support replication of the HRV-14 genome. This finding is in contrast to the cardiovirus cre, which has been shown to be functionally active between two members of its family, and further suggests that there is a close link between the evolution of the human rhinoviruses and the mechanisms of RNA replication.

  19. Antibodies to the buried N terminus of rhinovirus VP4 exhibit cross-serotypic neutralization.

    Science.gov (United States)

    Katpally, Umesh; Fu, Tong-Ming; Freed, Daniel C; Casimiro, Danilo R; Smith, Thomas J

    2009-07-01

    Development of a vaccine for the common cold has been thwarted by the fact that there are more than 100 serotypes of human rhinovirus (HRV). We previously demonstrated that the HRV14 capsid is dynamic and transiently displays the buried N termini of viral protein 1 (VP1) and VP4. Here, further evidence for this "breathing" phenomenon is presented, using antibodies to several peptides representing the N terminus of VP4. The antibodies form stable complexes with intact HRV14 virions and neutralize infectivity. Since this region of VP4 is highly conserved among all of the rhinoviruses, antiviral activity by these anti-VP4 antibodies is cross-serotypic. The antibodies inhibit HRV16 infectivity in a temperature- and time-dependent manner consistent with the breathing behavior. Monoclonal and polyclonal antibodies raised against the 30-residue peptide do not react with peptides shorter than 24 residues, suggesting that these peptides are adopting three-dimensional conformations that are highly dependent upon the length of the peptide. Furthermore, there is evidence that the N termini of VP4 are interacting with each other upon extrusion from the capsid. A Ser5Cys mutation in VP4 yields an infectious virus that forms cysteine cross-links in VP4 when the virus is incubated at room temperature but not at 4 degrees C. The fact that all of the VP4s are involved in this cross-linking process strongly suggests that VP4 forms specific oligomers upon extrusion. Together these results suggest that it may be possible to develop a pan-serotypic peptide vaccine to HRV, but its design will likely require details about the oligomeric structure of the exposed termini.

  20. Strong protection induced by an experimental DIVA subunit vaccine against bluetongue virus serotype 8 in cattle.

    Science.gov (United States)

    Anderson, Jenna; Hägglund, Sara; Bréard, Emmanuel; Riou, Mickaël; Zohari, Siamak; Comtet, Loic; Olofson, Ann-Sophie; Gélineau, Robert; Martin, Guillaume; Elvander, Marianne; Blomqvist, Gunilla; Zientara, Stéphan; Valarcher, Jean Francois

    2014-11-20

    Bluetongue virus (BTV) infections in ruminants pose a permanent agricultural threat since new serotypes are constantly emerging in new locations. Clinical disease is mainly observed in sheep, but cattle were unusually affected during an outbreak of BTV seroype 8 (BTV-8) in Europe. We previously developed an experimental vaccine based on recombinant viral protein 2 (VP2) of BTV-8 and non-structural proteins 1 (NS1) and NS2 of BTV-2, mixed with an immunostimulating complex (ISCOM)-matrix adjuvant. We demonstrated that bovine immune responses induced by this vaccine were as good or superior to those induced by a classic commercial inactivated vaccine. In this study, we evaluated the protective efficacy of the experimental vaccine in cattle and, based on the detection of VP7 antibodies, assessed its DIVA compliancy following virus challenge. Two groups of BTV-seronegative calves were subcutaneously immunized twice at a 3-week interval with the subunit vaccine (n=6) or with adjuvant alone (n=6). Following BTV-8 challenge 3 weeks after second immunization, controls developed viremia and fever associated with other mild clinical signs of bluetongue disease, whereas vaccinated animals were clinically and virologically protected. The vaccine-induced protection was likely mediated by high virus-neutralizing antibody titers directed against VP2 and perhaps by cellular responses to NS1 and NS2. T lymphocyte responses were cross-reactive between BTV-2 and BTV-8, suggesting that NS1 and NS2 may provide the basis of an adaptable vaccine that can be varied by using VP2 of different serotypes. The detection of different levels of VP7 antibodies in vaccinated animals and controls after challenge suggested a compliancy between the vaccine and the DIVA companion test. This BTV subunit vaccine is a promising candidate that should be further evaluated and developed to protect against different serotypes. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Genotyping and serotyping of macrolide and multidrug resistant Streptococcus pneumoniae isolated from carrier children

    Directory of Open Access Journals (Sweden)

    S F Swedan

    2016-01-01

    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.

  2. Complete genome of a dengue virus serotype 4 strain from Amazonas, Brazil.

    Science.gov (United States)

    Nascimento, Valdinete Alves do; Souza, Victor Costa de; Naveca, Felipe Gomes

    2016-02-01

    Dengue virus (DENV) infections represent a significant concern for public health worldwide, being considered as the most prevalent arthropod-borne virus regarding the number of reported cases. In this study, we report the complete genome sequencing of a DENV serotype 4 isolate, genotype II, obtained in the city of Manaus, directly from the serum sample, applying Ion Torrent sequencing technology. The use of a massive sequencing technology allowed the detection of two variable sites, one in the coding region for the viral envelope protein and the other in the nonstructural 1 coding region within viral populations.

  3. Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

    Institute of Scientific and Technical Information of China (English)

    Irfan; Ahmad; Mir; Sudhir; Kumar; Kashyap; Sunil; Maherchandani

    2015-01-01

    Objective: To study the occurrence and serotype diversity of Salmonella isolates in different species of poultry(chicken, emu and duck) and determine their resistance pattern against various antibiotics of different classes.Methods: About 507 samples comprising 202 caecal contents and 305 fecal samples from chicken, emu and duck were processed for isolation of Salmonella enterica. Salmonellae were isolated and detected by standard protocol of ISO 6579 Amendment 1: Annex D. Genetic confirmation was also made by using 16 S r RNA genus specific PCR. Serotype specific PCR was also done to detect the most common serovars viz. Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Gallinarum. All obtained isolates were subjected to a set of 25 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method.Results: Out of 507 samples processed, 32 isolates of Salmonella enterica(18 from caecal contents and 14 from faecal samples) were obtained, of which 24 belonged to 6 different serovars, 6 were untypeable and 2 were rough strains. Salmonella Enteritidis was the most predominant serotype(9), followed by Salmonella Typhimurium(5), Salmonella Virchow(4), Salmonella Gallinarum(3), Salmonella Reading(2) and Salmonella Altona(1). Antibiotic resistance pattern was maximum(100%) to oxacillin, penicillin and clindamycin, followed by ampicillin(68.75%), tetracycline(65.62%), nalidixic acid(56.25%) and colistin(46.87%). High sensitivity of isolates was recorded for chloramphenicol(96.87%) followed by meropenem(84.37%). Conclusions: Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in prophylaxis

  4. Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

    Institute of Scientific and Technical Information of China (English)

    Irfan Ahmad Mir; Sudhir Kumar Kashyap; Sunil Maherchandani

    2015-01-01

    Objective:To study the occurrence and serotype diversity of Salmonella isolates in different species of poultry (chicken, emu and duck) and determine their resistance pattern against various antibiotics of different classes. Methods:About 507 samples comprising 202 caecal contents and 305 fecal samples from chicken, emu and duck were processed for isolation of Salmonella enterica. Salmonellae were isolated and detected by standard protocol of ISO 6579 Amendment 1:Annex D. Genetic confirmation was also made by using 16S rRNA genus specific PCR. Serotype specific PCR was also done to detect the most common serovars viz. Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Gallinarum. All obtained isolates were subjected to a set of 25 antibiotics to study their antibiogram by using Baeur-Kirby disk diffusion method. Results:Out of 507 samples processed, 32 isolates of Salmonella enterica (18 from caecal contents and 14 from faecal samples) were obtained, of which 24 belonged to 6 different serovars, 6 were untypeable and 2 were rough strains. Salmonella Enteritidis was the most predominant serotype (9), followed by Salmonella Typhimurium (5), Salmonella Virchow (4), Salmonella Gallinarum (3), Salmonella Reading (2) and Salmonella Altona (1). Antibiotic resistance pattern was maximum (100%) to oxacillin, penicillin and clindamycin, followed by ampicillin (68.75%), tetracycline (65.62%), nalidixic acid (56.25%) and colistin (46.87%). High sensitivity of isolates was recorded for chloramphenicol (96.87%) followed by meropenem (84.37%). Conclusions:Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in

  5. Strategies to generate high-titer, high-potency recombinant AAV3 serotype vectors

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    Chen Ling

    2016-01-01

    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

  6. Detection of antibodies against Actinobacillus pleuropneumoniae serotype 5 using an inhibition enzyme immunoassay

    DEFF Research Database (Denmark)

    Stenbæk, Eva I.; DeLaSalle, F.; Gottschalk, M.

    1997-01-01

    inhibition of the MAb 210-F11. Pig serum from specific pathogen free (SPF) herds, from experimentally infected animals, and from acutely and chronically infected herds were tested, A serum dilution of 1/30 was found to be optimal, when using 50% inhibition as the discriminating inhibition percentage....... No cross-reactivity was observed with serum from pigs infected with other App serotypes or bacteria isolated from the respiratory tract, such as A. suis and H. parasuis. The inhibition EIA will be used for surviellance of App-5 antibodies in SPF and conventional herds....

  7. Sorbitol-negative phenotype among enterohemorrhagic Escherichia coli strains of different serotypes and from different sources.

    Science.gov (United States)

    Ojeda, A; Prado, V; Martinez, J; Arellano, C; Borczyk, A; Johnson, W; Lior, H; Levine, M M

    1995-08-01

    Enterohemorrhagic Escherichia coli (EHEC) strains detected with DNA probes (for virulence plasmid and Shiga-like toxins) from subjects with hemolytic-uremic syndrome (n = 19) or diarrhea (n = 41) or asymptomatic carriers (n = 29) were examined for sorbitol fermentability, as were enterotoxigenic (n = 40), enteropathogenic (n = 40), and enteroinvasive (n = 40) E. coli and urinary tract infection (n = 40) strains and normal flora E. coli strains (n = 40). Sorbitol negativity was common only in EHEC, particularly among strains from severe clinical infections. All 19 EHEC strains from patients with hemolytic-uremic syndrome, irrespective of O:H serotype or Shiga-like toxin genotype, were sorbitol negative.

  8. Isolation and serotyping of Streptococcus mutans from teeth and feces of children.

    OpenAIRE

    Hamada, S; Masuda, N; Kotani, S

    1980-01-01

    Streptococcus mutans were detected in the feces from 10 of 29 caries-active patients, aged 4 to 9 years. The percentage of S. mutans to the total counts of facultatively anaerobic streptococci on mitis salivarius agar (Difco Laboratories) varied from 0 to 72.5%. S. mutans were then isolated from dental plaque of sound teeth and carious dentin of the 10 subjects known to harbor S. mutans in the feces. The frequency distribution of various serotypes of these dental and fecal isolates of S. muta...

  9. Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

    OpenAIRE

    FitzGerald, R.J.; Adams, B. O.; Sandham, H. J.; Abhyankar, S

    1989-01-01

    A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation ...

  10. Prevalence of Salmonella in poultry carcasses serotypes in Birjand industrial slaughterhouses

    Directory of Open Access Journals (Sweden)

    Majid Zare Bidaki

    2013-08-01

    Conclusion: The results indicate that there is a relatively low prevalence of salmonella contamination in the poultry farms in the South Khorasan. Furthermore, lack of diversity in salmonella isolates reveals good health control and low levels of microbial transmission into poultry farms of this area. The outbreak of Salmonella infantis is uniformly consistent with the global spread of this serotype. Differences in the frequency of positive samples before and after placing the carcasses in boiling water may reveal the role of boiling process in reducing salmonella contamination of slaughtered poultry.

  11. An outbreak of Salmonella serotype Typhimurium infections with an unusually long incubation period.

    Science.gov (United States)

    Brooks, John T; Matyas, Bela T; Fontana, John; DeGroot, Mary Ann; Beuchat, Larry R; Hoekstra, Michael; Friedman, Cindy R

    2012-03-01

    A 1998 investigation of an outbreak of Salmonella serotype Typhimurium infections among children tasting unpasteurized milk during tours of a dairy farm demonstrated a distribution of unusually long incubation periods (median, 8 days; interquartile range [IQR], 6-14 days). Bacterial isolates were highly acid tolerant and contained genes associated with protection against destructive phagocytic reactive oxygen intermediates. We hypothesize that exposure to low-dose oral inoculum of a pathogen with these properties could have contributed to cases of non-typhoidal salmonellosis with the longest incubation period reported to the Centers for Disease Control and Prevention (CDC).

  12. Simultaneous Nasopharyngeal Carriage of Two Pneumococcal Multilocus Sequence Types with a Serotype 3 Phenotype

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    Donald Inverarity

    2010-01-01

    Full Text Available Knowledge of the epidemiology of pneumococcal disease in Bolivia is sparse, and Multilocus Sequence Typing (MLST of isolates has not been previously possible. Beni state has until recently been a geographically isolated region of the Bolivian Amazon basin and is a region of significant poverty. During June and July 2007, we performed a pneumococcal carriage study recruiting over 600 schoolchildren in two towns in the Beni state. Here, we describe the unique identification of simultaneous nasopharyngeal carriage of two pneumococcal multilocus sequence types with a serotype 3 phenotype within a single subject.

  13. Low prevalence of Salmonella in Swedish dairy herds highlight differences between serotypes.

    Science.gov (United States)

    Ågren, Estelle C C; Sternberg Lewerin, Susanna; Wahlström, Helene; Emanuelson, Ulf; Frössling, Jenny

    2016-03-01

    Legislated Salmonella control in Sweden has been in place since the 1960s. The purpose of this study was to investigate presence of Salmonella antibodies in dairy cattle herds and to provide a basis for decisions on how surveillance and control can be improved. Bulk milk samples from all Swedish dairy herds (n=4 683) were analysed with two different ELISAs; one detecting antibodies against Salmonella Dublin (Dublin ELISA), and one detecting antibodies against several of the serotypes causing bovine salmonellosis including S. Dublin (Bovine ELISA). Information about herds, i.e. geographical location, local animal density, number of test positive herds within 5km, animal trade and herd size, was based on register data. The results confirm a very low prevalence of Salmonella in Swedish dairy herds throughout the country with the exception of an island in the southeast. The test positive herds split into two groups; 41 herds (1%) positive in the Dublin ELISA, and 101 herds (2%) positive in the Bovine ELISA but negative in the Dublin ELISA. Geographical location of positive herds, and comparison of the results of the screening with serotypes previously isolated from some of the herds, indicated that the first group represents herds presently or previously infected with S. Dublin while the second group represents herds presently or previously infected with other serotypes. Differences in serological status between herds in different regions, of different size, with different animal purchase patterns et cetera, were tested using logistic regression. Presence of positive herds within 5km was significantly associated to testing positive. For herds testing positive in the Dublin ELISA, significant associations were also seen with herd size. Purchase of animals during the last year was not significantly associated with the outcome in the final models. We conclude that for future surveillance, the Bovine ELISA can be used to help in identifying infected herds, and the Dublin

  14. Isolation, serotype diversity and antibiogram of Salmonella enterica isolated from different species of poultry in India

    Directory of Open Access Journals (Sweden)

    Irfan Ahmad Mir

    2015-07-01

    Conclusions: Occurrence of high proportion of serovars in our study which can cause serious gastroenteritis in humans is a matter of concern. Salmonella Altona has been detected for the first time in India from poultry. This serotype is known to cause serious outbreaks of gastroenteritis in humans. Multidrug resistant isolates were recovered at high percentage which can be attributed to non-judicious use of antibiotics both in prophylaxis and treatment regimen. This observation draws serious attention as poultry serves as an important source of transmission of these multidrug resistant Salmonella serovars to humans.

  15. Salmonella Enterica Serotype Enteritidis Vertebral Osteomyelitis and Epidural Abscess Complicated with Meningitis.

    Science.gov (United States)

    Oki, Masayuki; Ueda, Akihiro; Tsuda, Ayumi; Yanagi, Hidetaka; Ozawa, Hideki; Takagi, Atsushi

    2016-09-20

    Infection with non-typhoidal Salmonella often results in a self-limited acute gastroenteritis. Extra-intestinal Salmonella infection is relatively rare and occurs predominantly in infants and adults with significant underlying conditions. We describe a 54-year-old Japanese man with a history of heavy alcohol consumption and daily contact with a dog, who developed bacteremia complicated by vertebral osteomyelitis, spinal epidural abscess, and meningitis, due to Salmonella enterica serotype Enteritidis. This case suggests that Salmonella should be considered as an etiologic pathogen in adult patients with perivertebral infection or meningitis.

  16. Antibody and splenocyte proliferation response to whole inactivated Streptococcus pneumoniae serotype 1, 3 and 6B in mice.

    Science.gov (United States)

    Pană, Marina; Orhan, Rasid; Bănică, Leontina; Iancu, Adina Daniela; Stăvaru, Crina

    2011-01-01

    Animal models of infection and protection on the topic of the Streptococcus pneumoniae (S. pneumoniae) have encountered many difficulties generated by low immunogenicity, a characteristic of polysaccharide capsular bacteria and difference of virulence between serotypes and strains. We have explored the immune response after immunization with heat inactivated S. pneumoniae serotype 1, 3 and 6B in C57BL/6 mice by IgM and IgG detection, and by splenocyte in vitro 5-ethynyl-2'-deoxyuridine (EdU) incorporation after antigen specific stimulation, as a proposed method of cellular immune response evaluation. Antibody titer persistence after immunization was not lengthy while antigen specific proliferation response detected by EdU assay was remnant. Intraperitoneal (i.p.) challenge with serotype 6B S. pneumoniae proved that antibody titers and the detected specific cellular immune response do not cover seroprotective necessity and do not confer improved immunologic memory in comparison to non-immunized mice, which show natural resistance.

  17. SEROTYPING AND ANTIMICROBIAL DRUG RESISTANCE OF SALMONELLA ISOLATED FROM LETTUCE AND HUMAN DIARRHEA SAMPLES IN BURKINA FASO.

    Science.gov (United States)

    Siourimè, Somda Namwin; Isidore, Bonkoungou Ouindgueta Juste; Oumar, Traoré; Nestor, Bassolé Ismael Henri; Yves, Traoré; Nicolas, Barro; Aly, Savadogo

    2017-01-01

    Background: In Burkina Faso dirty water in particular those of the stoppings and the gutter ones are used for vegetables irrigation in the gardens. The aim of this study was to determine the prevalence and antibiotic susceptibility of Salmonella serotypes from humans and lettuce samples inBurkina Faso. Materials and Methods:Salmonella strains isolated from patients in 2009 to 2015 and lettuce samples in 2014 in Burkina Faso were serotyped using specific antisera. All strains were subjected to a set of 14 antibiotics to study their antibiogram by using Baeur–Kirby disk diffusion method. Results: Out of 154 Salmonella isolated, 60 were from human and 94 from lettuce samples. Serotyping revealed four different serotypes and 39% (60) untypeable strains from human and lettuce (14 and 46 strains). Salmonella serotypes from human and lettuce samples were: Paratyphi A (10% and 22%), Paratyphi B (34% and 8%), Paratyphi C (14% and 18%) and Typhi (21% and 1%). A high resistance of Salmonella Paratyphi B and Salmonella spp to tetracycline were 70% from human and 35 % from lettuce samples. Multiresistance was observed to tetracycline, chloramphenicol and amoxicillin/clavulanic-acid or ampicillin with Salmonella ParatyphiB 35% and Salmonella Typhi 33% from human samples and Salmonella spp 4% from lettuce samples. Conclusion: This study showed the diversity of Salmonella serotypes from both clinical and environmental samples and emergence of multiresistant Salmonella to antibiotics in Burkina Faso. A lettuce is a potential source of transmission of Salmonella causing diarrhea among human in Burkina Faso. List of non-standard Abbreviations : HDB: Hôpital du District de Bogodogo, LNSP: Laboratoire National de Santé Publique, DSG : District Sanitaire de Gourcy, DSB : District Sanitaire de Boromo PMID:28670637

  18. Serotype/serogroup-specific antibiotic non-susceptibility of invasive and non-invasive Streptococcus pneumoniae, Switzerland, 2004 to 2014.

    Science.gov (United States)

    Hauser, Christoph; Kronenberg, Andreas; Allemann, Aurélie; Mühlemann, Kathrin; Hilty, Markus

    2016-05-26

    Concurrent analysis of antibiotic resistance of colonising and invasive Streptococcus pneumoniae gives a more accurate picture than looking at either of them separately. Therefore, we analysed 2,129 non-invasive and 10,996 invasive pneumococcal isolates from Switzerland from 2004 to 2014, which spans the time before and after the introduction of the heptavalent (PCV7) and 13-valent (PCV13) conjugated pneumococcal polysaccharide vaccines. Serotype/serogroup information was linked with all antibiotic resistance profiles. During the study period, the proportion of non-susceptible non-invasive and invasive isolates significantly decreased for penicillin, ceftriaxone, erythromycin and trimethoprim/sulfamethoxazole (TMP-SMX). This was most apparent in non-invasive isolates from study subjects younger than five years (penicillin (p = 0.006), erythromycin (p = 0.01) and TMP-SMX (p = 0.002)). Resistant serotypes/serogroups included in PCV7 and/or PCV13 decreased and were replaced by non-PCV13 serotypes (6C and 15B/C). Serotype/serogroup-specific antibiotic resistance rates were comparable between invasive and non-invasive isolates. Adjusted odds ratios of serotype/serogroup-specific penicillin resistance were significantly higher in the west of Switzerland for serotype 6B (1.8; 95% confidence interval (CI): 1.4-4.8), 9V (3.4; 95% CI: 2.0-5.7), 14 (5.3; 95% CI: 3.8-7.5), 19A (2.2; 95% CI: 1.6-3.1) and 19F (3.1; 95% CI: 2.1-4.6), probably due to variations in the antibiotic consumption.

  19. Serotypes and patterns of antibiotic resistance in strains causing invasive pneumococcal disease in children less than 5 years of age.

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    Chunfeng Liu

    Full Text Available OBJECTIVE: The serotypes and patterns of antibiotic resistance of Streptococcus pneumoniae (S. pneumoniae strains that cause invasive pneumococcal disease (IPD in infants were analyzed to provide guidance for clinical disease prevention and treatment. METHODS: The clinical features of confirmed IPD were evaluated in 61 patients, less than 5 years of age, who were admitted to our hospital between January 2009 and December 2011. The serotypes and antibiotic resistance of strains of S.pneumoniae were determined using the capsular swelling method and the E-test. RESULTS: A total of 61 invasive strains were isolated. The serotype distribution of those isolates were 19A (41.0%, 14 (19.7%, 19F (11.5%, 23F (9.8%, 8 (4.9%, 9V (4.9%, 1 (3.3%, and 4, 6B, and 20 (each 1.6%. The percentage of S. pneumoniae strains resistant to erythromycin, clindamycin, and cotrimoxazole were 100%, 86.9%, and 100%, respectively. The percentage of S. pneumoniae strains resistant to penicillin, amoxicillin/clavulanic acid, cefuroxime, ceftriaxone, cefotaxime, cefepime, and meropenem were 42.6%, 18.0%, 82.0%, 18.0%, 13.1%, 13.1%, and 36.1%, respectively. The percentage of multidrug-resistant strains was 95.6%. Strains of all serotypes isolated in this study were highly resistant to erythromycin, cotrimoxazole, and clindamycin. Strains with serotype 19A had the highest rates of resistance. CONCLUSIONS: Serotype 19A strains were most frequently isolated from children with IPD treated in our hospital. The strains causing IPD are highly resistant to antibiotics.

  20. Molecular Serotype-Specific Identification of Non-type b Haemophilus influenzae by Loop-Mediated Isothermal Amplification

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    Chika Takano

    2017-10-01

    Full Text Available Over the past four decades, the incidence of meningitis caused by Haemophilus influenzae in children has decreased due to widespread vaccination against H. influenzae type b (Hib. The incidence of invasive diseases due to H. influenzae types not included in the vaccines, however, has increased. At present, there are a limited number of diagnostics available to detect non-type b H. influenzae. To address this issue, we developed a rapid, simple, and cost-effective method for detecting serotypes of H. influenzae. We designed LAMP primer sets based on published sequences for H. influenzae capsular types a, c, d, e, and f. The assay was evaluated to determine test reactivity, specificity, and sensitivity. To support its use in patients with suspected meningitis, we evaluated the detection limit of the non-Hib serotype specific LAMP assay using bacterial genomic DNA-spiked cerebrospinal fluid (CSF specimens. The reactivity and specificity of the LAMP assays were confirmed using six serotypes and non-typeable H. influenzae strains, plus eight strains of other Haemophilus species and non-Haemophilus genera. The detection limits of the LAMP assay for capsular types a, c, d, e, and f were 102, 102, 102, 103, and 10 copies per reaction, while those of the PCR assay were 104, 104, 103, 103, and 104 genome copies per reaction, respectively. Using DNA-spiked CSF specimens, the detection limit of the LAMP assay was equivalent to that using purified DNA as the template. However, the detection limit of the PCR was reduced from 103 to 104 genome copies per reaction for serotype d and from 103 to 105 genome copies per reaction for serotype e. To the best of our knowledge, this is the first report of a serotype-specific identification assay for H. influenzae using the LAMP method. Our results suggest the potential of LAMP methods for patients with suspected meningitis in resource-limited laboratories or public health surveillance systems.

  1. Genetic diversity of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates and the first identification of serotype 20B in China.

    Science.gov (United States)

    Guo, Q; Zhuo, C; Xu, Y; Huang, W; Wang, C; Zhang, S; Huang, J; Hu, F; Zhu, D; Yang, F; Wang, M

    2014-03-01

    The purpose of this study was to investigate the genetic characteristics of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates in China. A total of 377 S. pneumoniae clinical isolates, including 307 pediatric strains and 70 adult strains, were collected from eight centers in China. The minimal inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by agar dilution. Multilocus sequence typing (MLST), serotyping, and quinolone resistance-determining region (QRDR) variations were conducted in levofloxacin-nonsusceptible isolates by polymerase chain reaction (PCR)-based methods. Seven levofloxacin-nonsusceptible isolates were found, with an overall resistance rate of 1.9 % (7/377) and 8.6 % (6/70) in adults. Sequence analyses of parC, gyrA, and parE QRDRs in levofloxacin-resistant isolates demonstrated mutations in dual target sites at the hot spots. These seven strains represented multiple clones: two strains were serotype 19F (Taiwan(19F)-14) and MLST clonal complex (CC) 271/320, two were typed as 23F (Spain(23F)-1) and CC81, two were determined as serotype 20B and a new sequence type of ST6935, and one non-serotypeable pediatric strain belonged to a new sequence type of ST6946. Two serotype 19F strains possessed a variety of characteristic alterations of viridans group streptococci in gyrA (Ser114Gly) or parC (Ser52Gly, Asn91Asp). Fluoroquinolone-nonsusceptible S. pneumoniae isolates showed a substantial degree of genetic diversity and belonged to pre-existing epidemic clones together with native clones. S. pneumoniae strains with serotype 20B was recovered for the first time to be associated with levofloxacin resistance in China.

  2. Dengue E Protein Domain III-Based DNA Immunisation Induces Strong Antibody Responses to All Four Viral Serotypes.

    Directory of Open Access Journals (Sweden)

    Monica Poggianella

    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.

  3. Dengue E Protein Domain III-Based DNA Immunisation Induces Strong Antibody Responses to All Four Viral Serotypes.

    Science.gov (United States)

    Poggianella, Monica; Slon Campos, José L; Chan, Kuan Rong; Tan, Hwee Cheng; Bestagno, Marco; Ooi, Eng Eong; Burrone, Oscar R

    2015-01-01

    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.

  4. Convalescent pigs are protected completely against infection with a homologous Actinobacillus pleuropneumoniae strain but incompletely against a heterologous-serotype strain

    NARCIS (Netherlands)

    Cruijsen, A.L.M.; Leengoed, van L.A.M.G.; Ham-Hoffjes, M.; Verheijden, J.H.M.

    1995-01-01

    To study whether Actinobacillus pleuropneumoniae induces a species- specific immunity, we infected pigs in the left lung with serotype 3 or 9 and after 3 weeks we infected their right lungs with serotype 9. Convalescent pigs were protected against homologous strain reinfection, but after

  5. Whole genome sequencing and phylogenetic analysis of Bluetongue virus serotype 2 strains isolated in the Americas including a novel strain from the western United States

    Science.gov (United States)

    Bluetongue is caused by an arbovirus which produces widespread edema and tissue necrosis in domestic and wild ruminants that can be fatal. Bluetongue virus serotypes 10, 11, 13, and 17 are typically found throughout the United States (US), while serotype 2 was previously only detected in the southea...

  6. Analysis of Recent Serotype O Foot‐and‐Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages

    DEFF Research Database (Denmark)

    Wekesa, S. N.; Muwanika, V. B.; Siegismund, H. R.;

    2015-01-01

    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...

  7. Serotype- and strain- dependent contribution of the sensor kinase CovS of the CovRS two-component system to Streptococcus pyogenes pathogenesis

    Directory of Open Access Journals (Sweden)

    Podbielski Andreas

    2010-02-01

    Full Text Available Abstract Background The Streptococcus pyogenes (group A streptococci, GAS two-component signal transduction system CovRS has been described to be important for pathogenesis of this exclusively human bacterial species. If this system acts uniquely in all serotypes is currently unclear. Presence of serotype- or strain-dependent regulatory circuits and polarity is an emerging scheme in Streptococcus pyogenes pathogenesis. Thus, the contribution of the sensor kinase (CovS of the global regulatory two-component signal transduction system CovRS on pathogenesis of several M serotypes was investigated. Results CovS mutation uniformly repressed capsule expression and hampered keratinocyte adherence in all tested serotypes. However, a serotype- and even strain-dependent contribution on survival in whole human blood and biofilm formation was noted, respectively. Conclusions These data provide new information on the action of the CovS sensor kinase and revealed that its activity on capsule expression and keratinocyte adherence is uniform across serotypes, whereas the influence on biofilm formation and blood survival is serotype or even strain dependent. This adds the CovRS system to a growing list of serotype-specific acting regulatory loci in S. pyogenes.

  8. Changing trends in serotypes of S. pneumoniae isolates causing invasive and non-invasive diseases in unvaccinated population in Mexico (2000-2014

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    María Noemí Carnalla-Barajas

    2017-05-01

    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.

  9. Animal salmonellosis in peninsular Malaysia. II. Annual and zoological distribution of Salmonella serotypes over the 10-year period 1966-1975.

    Science.gov (United States)

    Joseph, P G; Anwar, M; Jegathesan, M

    1978-05-01

    A total of 860 Salmonella isolations were made in Peninsular Malaysia from 15 animal species (domestic and wild), eggs, molluscs, flies, and animal feed. The isolations were distributed among 31 serotypes in eight groups. The most common serotype isolated was Salmonella pullorum, followed by S. choleraesuis and S. infantis. S. typhimurium had the widest zoological distribution. The importance of controlling animal salmonellosis is emphasized.

  10. transcriptional response of pigs to Salmonella infection: Comparison of responses to infection with Salmonella eimerica serotype Typhimurium as that observed in S. choleraesuis infection.

    Science.gov (United States)

    Swine responses to, and control of, Salmonella enterica serotype Typhimurium (ST) infection have been compared to S. enterica serotype Choleraesuis (SC) infection. Using subtractive suppression hybridization (SSH), long oligonucleotide Qiagen and Affymetrix porcine GeneChip® arrays, and real time ge...

  11. Novel chimeric foot-and-mouth disease virus-like particles harboring serotype O VP1 protect guinea pigs against challenge.

    Science.gov (United States)

    Li, Haitao; Li, Zhiyong; Xie, Yinli; Qin, Xiaodong; Qi, Xingcai; Sun, Peng; Bai, Xingwen; Ma, Youji; Zhang, Zhidong

    2016-02-01

    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.

  12. Immunogenicity, biochemical and serological characterizations of ribosomal preparations from human oral strains of serotypes c and d of the bacterium Streptococcus mutans

    NARCIS (Netherlands)

    Fischer, M.; Huis in t Veld, J.

    1984-01-01

    Crude ribosomal preparations of Streptococcus mutans C67-1 (serotype c) and 50B4 (serotype d) contain protein RNA and carbohydrate. Sepharose CL-2B column chromatography of preparations yielded two distinct peaks. Cell-wall carbohydrates were predominantly present in peak I; the serological activity

  13. Whole Genome Sequencing of 39 Invasive Streptococcus pneumoniae Sequence Type 199 Isolates Revealed Switches from Serotype 19A to 15B

    Science.gov (United States)

    Lucas, Marie; Brandt, Christian; Herrmann, Leonie; Albersmeier, Andreas; Blom, Jochen; Goesmann, Alexander

    2017-01-01

    Streptococcus pneumoniae is a major pathogen that causes different invasive pneumococcal diseases (IPD). The pneumococcal polysaccharide capsule is a main virulence factor. More than 94 capsule types have been described, but only a limited number of capsule types accounted for the majority of IPD cases before the introduction of pneumococcal vaccines. After the introduction of the conjugated pneumococcal vaccine PCV7, which covered the seven most frequent serotypes in IPD in the USA, an increase in IPD caused by non-vaccine serotypes was observed, and serotype 19A, which belongs to sequence type (ST) 199, was among the most prevalent STs. After the introduction of the extended vaccine PCV13, which includes serotype 19A, serogroup 15B/C increased in IPD. Therefore, whole genome sequences of 39 isolates of ST199 from Germany (collected between 1998 and 2011) with serotype 19A (n = 24) and serogroup 15B/C (n = 15) were obtained using an Illumina platform and were analysed to identify capsular switches within ST199. Two 19A to 15B/C serotype switch events were identified. Both events occurred before the introduction of PCV7, which indicates that a capsular switch from 19A to 15B among ST199 isolates is not unusual and is not directly linked to the vaccination. The observed serotype replacement appears to be the result of a vacant niche due to the displacement of vaccine serotypes that is now successfully occupied by ST199 clones. PMID:28046133

  14. Analysis of Recent Serotype O Foot‐and‐Mouth Disease Viruses from Livestock in Kenya: Evidence of Four Independently Evolving Lineages

    DEFF Research Database (Denmark)

    Wekesa, S. N.; Muwanika, V. B.; Siegismund, H. R.

    2015-01-01

    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...

  15. Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea.

    Directory of Open Access Journals (Sweden)

    Juan M Pacheco

    Full Text Available 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.

  16. Comparative protection of two different commercial vaccines against Yersinia ruckeri serotype O1 and biotype 2 in rainbow trout (Oncorhynchus mykiss)

    DEFF Research Database (Denmark)

    Deshmukh, S.; Raida, M. K.; Dalsgaard, Inger

    2012-01-01

    Differentially extended specific protection by two commercial vaccines against Yersinia ruckeri serotype O1 biotype 2 was studied following 30s immersion exposure. Rainbow trout were challenged intra-peritoneally (i.p.) with Y. ruckeri serotype O1, biotype 2 (≈106 to 107CFU/fish) at 4, 6 and 8...

  17. Field observations during the bluetongue serotype 8 epidemic in 2006 I. Detection of first outbreaks and clinical signs in sheep and cattle in Belgium, France ande the Netherlands

    NARCIS (Netherlands)

    Elbers, A.R.W.; Backx, A.; Meroc, E.; Gerbier, G.; Staubach, C.; Hendrickx, G.; Spek, van der A.N.; Mintiens, K.

    2008-01-01

    Starting August 2006, a major epidemic of bluetongue (BT) was identified in North-West Europe, affecting The Netherlands, Belgium, Germany, Luxemburg and the North of France. It was caused by BT virus serotype 8 (BTV-8), a serotype previously unknown to the European Union (EU). In this outbreak, the

  18. Phylogenetic analyses of the polyprotein coding sequences of serotype O foot-and-mouth disease viruses in East Africa: evidence for interserotypic recombination

    DEFF Research Database (Denmark)

    Balinda, Sheila; Siegismund, Hans; Muwanika, Vincent;

    2010-01-01

    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 evolutio...

  19. Application of photostable quantum dots for indirect immunofluorescent detection of specific bacterial serotypes on small marine animals

    Science.gov (United States)

    Decho, Alan W.; Beckman, Erin M.; Chandler, G. Thomas; Kawaguchi, Tomohiro

    2008-06-01

    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.

  20. Co-circulation of two extremely divergent serotype SAT 2 lineages in Kenya highlights challenges to foot-and-mouth disease control

    DEFF Research Database (Denmark)

    Sangula, Abraham; Belsham, Graham; Muwanika, Vincent

    2010-01-01

    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...... a period of 50 years. Two highly divergent lineages were observed to co-circulate, and occasional trans-boundary spread was inferred, emphasizing the value of constant monitoring and characterization of field strains for improved diagnosis and appropriate vaccine application as well as the need...

  1. Genetic diversity of serotype A foot-and-mouth disease viruses in Kenya from 1964 to 2013; implications for control strategies in eastern Africa

    DEFF Research Database (Denmark)

    Wekesa, Sabenzia N.; Sangula, Abraham K.; Belsham, Graham

    2014-01-01

    (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......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...... 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...

  2. Co-circulation of two extremely divergent serotype SAT 2 lineages in Kenya highlights challenges to foot-and-mouth disease control.

    Science.gov (United States)

    Sangula, A K; Belsham, G J; Muwanika, V B; Heller, R; Balinda, S N; Siegismund, H R

    2010-10-01

    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 a period of 50 years. Two highly divergent lineages were observed to co-circulate, and occasional trans-boundary spread was inferred, emphasizing the value of constant monitoring and characterization of field strains for improved diagnosis and appropriate vaccine application as well as the need for regional approaches to control.

  3. The dynamics of dengue virus serotype 3 introduction and dispersion in the state of Bahia, Brazil

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Santana de Melo

    2007-12-01

    Full Text Available By 2002, dengue virus serotype 1 (DENV-1 and DENV-2 had circulated for more than a decade in Brazil. In 2002, the introduction of DENV-3 in the state of Bahia produced a massive epidemic and the first cases of dengue hemorrhagic fever. Based on the standardized frequency, timing and location of viral isolations by the state's Central Laboratory, DENV-3 probably entered Bahia through its capital, Salvador, and then rapidly disseminated to other cities, following the main roads. A linear regression model that included traffic flow, distance from the capital and DENV-1 circulation (r² = 0.24, p = 0.001 supported this hypothesis. This pattern was not seen for serotypes already in circulation and was not seen for DENV-3 in the following year. Human population density was another important factor in the intensity of viral circulation. Neither DENV-1 nor DENV-2 fit this model for 2001 or 2003. Since the vector has limited flight range and vector densities fail to correlate with intensity of viral circulation, this distribution represents the movement of infected people and to some extent mosquitoes. This pattern may mimic person-to-person spread of a new infection.

  4. Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

    Science.gov (United States)

    Weishaupt, Markus W; Matthies, Stefan; Hurevich, Mattan; Pereira, Claney L; Hahm, Heung Sik

    2016-01-01

    Summary 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. PMID:27559395

  5. Listeriosis outbreak in dairy cattle caused by an unusual Listeria monocytogenes serotype 4b strain.

    Science.gov (United States)

    Bundrant, Brittany N; Hutchins, Tony; den Bakker, Henk C; Fortes, Esther; Wiedmann, Martin

    2011-01-01

    A listeriosis outbreak, in dairy cattle, with a high case mortality and acute death after onset of symptoms was investigated using gross pathology and bacteriologic approaches, including molecular characterization of a clinical Listeria monocytogenes isolate. In a herd of 315 animals, 9 animals showed clinical symptoms consistent with listeriosis, including 3 animals that died within 2-4 days after acute onset of clinical signs, 4 animals that were euthanized, and 2 that survived. Initial EcoRI ribotyping and serotyping indicated that this outbreak was caused by an unusual L. monocytogenes serotype 4b strain, which was classified into lineage III. Further characterization of this isolate by DNA sequencing-based subtyping methods indicated that the strain responsible for this outbreak represented a unique genotype as supported by its classification into a new sigB allelic type, which has not been identified previously among >290 isolates, and by compelling phylogenetic evidence. While lineage III isolates are generally rare, they seem to be more common among L. monocytogenes isolates from animals with clinical signs of listeriosis. This is the first report of a particularly severe clinical course of disease associated with infection by a lineage III strain. The high prevalence of Listeria spp., including L. monocytogenes, in the farm environments may favor emergence and evolution of novel, and possibly more virulent, L. monocytogenes strains. Continued monitoring of animal listeriosis cases and outbreaks may not only improve animal health but also aid in the early discovery of newly emerging L. monocytogenes strains.

  6. Characterization of Klebsiella terrigena strains from humans: haemagglutinins, serum resistance, siderophore synthesis, and serotypes.

    Science.gov (United States)

    Podschun, R; Fischer, A; Ullmann, U

    2000-08-01

    Klebsiella terrigena is very rarely isolated from humans; as yet, its clinical significance is uncertain. The aim of the present study was to evaluate whether this species is able to express putative virulence factors. A total of 72 faecal (n = 50) and clinical (n = 22) K. terrigena isolates was investigated and compared with faecal and clinical strains of K. pneumoniae. Mannose-sensitive haemagglutination (MSHA) was observed less often in K. terrigena (64-74%) than in K. pneumoniae strains. In contrast, the incidence of mannose-resistant haemagglutinin indicative of type 3 pili (MR/K-HA) (77-94%), serum resistance properties (10-23%), and production of enterobactin (100%) was similar in both species. None of the K. terrigena isolates were able to synthesize aerobactin; however, the frequency of aerobactin synthesis in K. pneumoniae was also only 5%. Serotyping showed capsular types K5 and K70 to be predominant. The virulence-associated serotype K2 was common in both K. terrigena and K. pneumoniae isolates. Taken together, the present results suggest that K. terrigena and K. pneumoniae are indistinguishable with respect to the expression of virulence factors.

  7. Nontyphoidal salmonella infection in children with acute gastroenteritis: prevalence, serotypes, and antimicrobial resistance in Shanghai, China.

    Science.gov (United States)

    Li, Yuefang; Xie, Xinbao; Xu, Xuebing; Wang, Xiangshi; Chang, Hailing; Wang, Chuanqing; Wang, Aiming; He, Yanlei; Yu, Hui; Wang, Xiaohong; Zeng, Mei

    2014-03-01

    Information about nontyphoidal Salmonella (NTS) infection in children is limited in mainland China. The objective of this study was to investigate the prevalence, serotypes, and antibiotic resistance patterns of NTS infection in children in Shanghai. All cases with probable bacterial diarrhea were enrolled from the enteric clinic of a tertiary pediatric hospital between July 2010 and December 2011. Salmonella isolation, serotyping, and antimicrobial susceptibility testing were conducted by the microbiological laboratory. NTS were recovered from 316 (17.2%) of 1833 cases with isolation rate exceeding Campylobacter (7.1%) and Shigella (5.7%). NTS infection was prevalent year-round with a seasonal peak during summer and autumn. The median age of children with NTS gastroenteritis was 18 months. Fever and blood-in-stool were reported in 52.5% and 42.7% of cases, respectively. Salmonella Enteritidis (38.9%) and Salmonella Typhimurium (29.7%) were the most common serovars. Antimicrobial susceptibility showed 60.5% of isolates resistant to ≥1 clinically important antibiotics. Resistance to ciprofloxacin and the third-generation cephalosporins was detected in 5.5% and 7.1%-11.7% of isolates, respectively. NTS is a major enteropathogen responsible for bacterial gastroenteritis in children in Shanghai. Resistance to the current first-line antibiotics is of concern. Ongoing surveillance for NTS infection and antibiotic resistance is needed to control this pathogen in Shanghai.

  8. Clonal analysis of Escherichia coli serotype O6 strains from urinary tract infections.

    Science.gov (United States)

    Zingler, G; Ott, M; Blum, G; Falkenhagen, U; Naumann, G; Sokolowska-Köhler, W; Hacker, J

    1992-04-01

    A total of 36 Escherichia coli urinary tract isolates (UTI) of serotype O6, with different combinations of capsule (K) and flagellin (H) antigens, were analysed according to the outer membrane pattern (OMP), serum resistance properties, mannose-resistant hemagglutination using various types of erythrocytes, and also for the genetic presence and the expression of P-fimbriae, S fimbriae/F1C fimbriae, Type 1 fimbriae, aerobactin and hemolysin. Twenty selected strains were further analysed by pulsed field gel electrophoresis (PFGE), elaborating genomic profiles by XbaI cleavage and subsequent Southern hybridization to virulence-associated DNA probes. It could be shown that O6 UTI isolates represent a highly heterogeneous group of strains according to the occurrence and combination of these traits. Relatedness on the genetic and the phenotypic level was found for some of the strains exhibiting the same O:K:H:F serotype. DNA long-range mapping further indicated some interesting features, according to the copy number and the genomic linkage of virulence genes.

  9. Automated glycan assembly of a S. pneumoniae serotype 3 CPS antigen

    Directory of Open Access Journals (Sweden)

    Markus W. Weishaupt

    2016-07-01

    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.

  10. Genetically similar isolates of Klebsiella pneumoniae serotype K1 causing liver abscesses in three continents.

    Science.gov (United States)

    Turton, Jane F; Englender, Hilary; Gabriel, Samantha N; Turton, Sarah E; Kaufmann, Mary E; Pitt, Tyrone L

    2007-05-01

    The magA gene was sought in hypermucoviscous isolates of Klebsiella spp., the Klebsiella K serotype reference strains and in isolates of the K1 serotype of Klebsiella pneumoniae from the UK, Hong Kong, Israel, Taiwan and Australia. Only K1 isolates were PCR positive for magA; this gene was found in all such isolates tested. Hypermucoviscosity was not confined to magA positive isolates, nor was it found in all magA positive isolates. Comparison of XbaI PFGE profiles revealed that most (19/23) of the magA positive isolates clustered within 72 % similarity, with a further subcluster of isolates, from three different continents, clustering within >80 %. All of the 16 isolates tested within the main cluster had the same sequence type (ST 23) by multilocus sequence typing, with the exception of one isolate, which had a single nucleotide difference at one of the seven loci. This study indicates that a genotype strongly associated with highly invasive disease in Taiwan, where large numbers of cases have been reported, is geographically very widespread.

  11. [Phylogenetic analysis of envelope gene of dengue virus serotype 2 in Guangzhou, 2001-2015].

    Science.gov (United States)

    Liu, Y; Jiang, L Y; Luo, L; Cao, Y M; Jing, Q L; Yang, Z C

    2017-01-10

    Objective: To investigate the molecular characteristics of dengue virus serotype 2 (DENV2) in Guangzhou during 2001-2015, and analyze the E gene of the strains isolated, the phylogenetic tree and molecular clock were constructed to know about the evolution of the strains. Methods: The serum samples of the patients were detected by real time PCR, and positive samples were used to isolate dengue virus by using C6/36 cells. The E gene of the isolated strains were sequenced. The phylogenetic tree was constructed by using software Mega 4.0, and the molecular clock was drawn by using software BEASTv1.8.2. Results: Twenty-six dengue virus strains were isolated between 2001 and 2015. They were all clustered into 2 genotypes, i.e. cosmopolitan genotype and Asian genotype Ⅰ. The strains isolated in Guangzhou shared high homology with Southeast Asian strains. The cosmopolitan genotype was divided into 2 sub-genotype at about 46 and 35 years ago. The substitution rate of dengue virus serotype 2 in Guangzhou was 7.1 × 10(-4) per year per site. Conclusions: There were close relationship between the Guangzhou strains and Southeast Asian strains. Guangzhou was at high risk of imported dengue fever, outbreak of dengue hemorrhagic fever and dengue shock syndrome. There might be two ways of introduction of cosmopolitan genotype. The substitution rate of the strains in Guangzhou was similar to that in the neighbor countries.

  12. Increasing airline travel may facilitate co-circulation of multiple dengue virus serotypes in Asia.

    Science.gov (United States)

    Tian, Huaiyu; Sun, Zhe; Faria, Nuno Rodrigues; Yang, Jing; Cazelles, Bernard; Huang, Shanqian; Xu, Bo; Yang, Qiqi; Pybus, Oliver G; Xu, Bing

    2017-08-01

    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.

  13. Novel adenovirus vaccine vectors based on the enteric-tropic serotype 41.

    Science.gov (United States)

    Lemiale, Franck; Haddada, Hedi; Nabel, Gary J; Brough, Douglas E; King, C Richter; Gall, Jason G D

    2007-03-01

    Replication-defective adenovirus vectors, primarily developed from serotype 5 (Ad5) viruses, have been widely used for gene transfer and vaccination approaches. Vectors based on other serotypes of adenovirus could be used in conjunction with, or in place of, Ad5 vectors. In this study, Ad41, an enteric adenovirus usually described as 'non-cultivable' or 'fastidious,' has been successfully cloned, rescued and propagated on 293-ORF6 cells. The complementation capabilities of this cell line allow generation of Ad41 vectors at titers comparable to those obtained for Ad5 vectors. Mice immunized with an Ad41 vector containing an HIV envelope (Env) gene mounted anti-Env cellular and humoral immune responses. Ad41-Env vectors appear to be particularly attractive when used in heterologous prime-boost regimens, where they induce significantly higher cellular immune responses to HIV-Env than Ad5-based regimens. Ad41-based constructs are attractive vaccine vectors alone or in combination with Ad5 adenovectors, since each vector type can provide circumvention of pre-existing immunity to the other.

  14. Single rapid TaqMan fluorogenic probe based PCR assay that detects all four dengue serotypes.

    Science.gov (United States)

    Warrilow, David; Northill, Judith A; Pyke, Alyssa; Smith, Greg A

    2002-04-01

    Public health laboratories require rapid diagnosis of dengue outbreaks for application of measures such as vector control. We have developed a rapid single fluorogenic probe-based polymerase chain reaction assay for the detection of all four dengue serotypes (FUDRT-PCR). The method employs primers and probe that are complementary to the evolutionarily conserved 3' untranslated region of the dengue genome. The assay detected viral RNA of strains of all four dengue serotypes but not of the flaviviruses Japanese encephalitis virus, Murray Valley encephalitis virus, Kunjin, Stratford, West Nile, Alfuy or Yellow fever. When compared to an existing nested-PCR assay for the detection of dengue on clinical samples, FUDRT-PCR detected dengue 1 (100%, n=14), dengue 2 (85%, n=13), dengue 3 (64%, n=14) and dengue 4 (100%, n=3) with the indicated sensitivities. FUDRT-PCR enables diagnosis of acute dengue infection in four hours from sample receipt. In addition, a single-test procedure should result in a reduction in the number of tests performed with considerable cost savings for diagnostic laboratories.

  15. Analysis of Haemophilus influenzae serotype f isolated from three Japanese children with invasive H. influenzae infection.

    Science.gov (United States)

    Hoshino, Tadashi; Hachisu, Yushi; Kikuchi, Takashi; Tokutake, Shoko; Okui, Hideyuki; Kutsuna, Satoru; Fukasawa, Chie; Murayama, Kei; Oohara, Asami; Shimizu, Hiroyuki; Ito, Midori; Takahashi, Yoshiko; Ishiwada, Naruhiko

    2015-04-01

    In Japan, publicly subsidized Haemophilus influenzae serotype b vaccines became available in 2011; consequently, the incidence of invasive H. influenzae infection in paediatric patients of less than 5 years of age decreased dramatically. In 2013, the first case of H. influenzae serotype f (Hif) meningitis in a Japanese infant was reported, and another case of Hif meningitis in a Japanese infant was observed in 2013. We experienced a fatal paediatric case of Hif bacteraemia in 2004; therefore, we conducted an analysis of the three Hif strains isolated from these three Japanese children with invasive Hif infections. All three strains were β-lactamase-non-producing, ampicillin-sensitive strains, with MICs of 1 µg ml(-1) or less. However, one of the three strains showed slightly elevated MICs for ampicillin (1 µg ml(-1)), cefotaxime (0.25 µg ml(-1)) and meropenem (0.13 µg ml(-1)). A molecular analysis by multilocus sequence typing identified all three strains as sequence type (ST) 124, which is a predominant invasive Hif strain in many countries. SmaI-digested PFGE showed variable DNA fragmentation patterns among the strains, suggesting that some highly virulent strains have originated from a single ST124 clone and caused invasive Hif infections in Japan. Additional studies are needed to determine the factors that have led to the clonal expansion of virulent ST124 strains.

  16. Evolutionary Analysis of Dengue Serotype 2 Viruses Using Phylogenetic and Bayesian Methods from New Delhi, India.

    Directory of Open Access Journals (Sweden)

    Nazia Afreen

    2016-03-01

    Full Text Available Dengue fever is the most important arboviral disease in the tropical and sub-tropical countries of the world. Delhi, the metropolitan capital state of India, has reported many dengue outbreaks, with the last outbreak occurring in 2013. We have recently reported predominance of dengue virus serotype 2 during 2011-2014 in Delhi. In the present study, we report molecular characterization and evolutionary analysis of dengue serotype 2 viruses which were detected in 2011-2014 in Delhi. Envelope genes of 42 DENV-2 strains were sequenced in the study. All DENV-2 strains grouped within the Cosmopolitan genotype and further clustered into three lineages; Lineage I, II and III. Lineage III replaced lineage I during dengue fever outbreak of 2013. Further, a novel mutation Thr404Ile was detected in the stem region of the envelope protein of a single DENV-2 strain in 2014. Nucleotide substitution rate and time to the most recent common ancestor were determined by molecular clock analysis using Bayesian methods. A change in effective population size of Indian DENV-2 viruses was investigated through Bayesian skyline plot. The study will be a vital road map for investigation of epidemiology and evolutionary pattern of dengue viruses in India.

  17. Vector competence of Malaysian Aedes albopictus with and without Wolbachia to four dengue virus serotypes.

    Science.gov (United States)

    Joanne, Sylvia; Vythilingam, Indra; Teoh, Boon-Teong; Leong, Cherng-Shii; Tan, Kim-Kee; Wong, Meng-Li; Yugavathy, Nava; AbuBakar, Sazaly

    2017-09-01

    To determine the susceptibility status of Aedes albopictus with and without Wolbachia to the four dengue virus serotypes. Two newly colonised colonies of Ae. albopictus from the wild were used for the study. One colony was naturally infected with Wolbachia while in the other Wolbachia was removed by tetracycline treatment. Both colonies were orally infected with dengue virus-infected fresh blood meal. Dengue virus load was measured using quantitative RT-PCR at four-time intervals in the salivary glands, midguts and ovaries. Wolbachia did not significantly affect Malaysian Ae. albopictus dengue infection or the dissemination rate for all four dengue virus serotypes. Malaysian Ae. albopictus had the highest replication kinetics for DENV-1 and the highest salivary gland and midgut infection rate for DENV-4. Wolbachia, which naturally exists in Malaysian Ae. albopictus, does not significantly affect dengue virus replication. Malaysian Ae. albopictus is susceptible to dengue virus infections and capable of transmitting dengue virus, especially DENV-1 and DENV-4. Removal of Wolbachia from Malaysian Ae. albopictus would not reduce their susceptibility status. © 2017 John Wiley & Sons Ltd.

  18. The risk on contact people with different serotypes of sticks the Yersinia

    Directory of Open Access Journals (Sweden)

    Nimfa Maria Stojek

    2011-03-01

    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 %.

  19. Avian paramyxovirus serotype 3 infection in Neopsephotus, Cyanoramphus, and Neophema species.

    Science.gov (United States)

    Jung, Arne; Grund, Christian; Müller, Inge; Rautenschlein, Silke

    2009-09-01

    An outbreak of avian paramyxovirus serotype 3 (APMV-3) infection occurred in a private bird collection consisting mainly of Neophema species. Two Bourke's parrots (Neopsephotus bourkii) and one red-crowned parakeet (Cyanoramphus novaezelandiae) were examined after developing torticollis and circling. The 3 birds were euthanatized and submitted for necropsy. Brain and liver samples from the 3 birds were homogenized and inoculated into the allantoic cavity of 10-day-old embryonated specific-pathogen-free chicken eggs. An APMV-3 isolate replicated but did not induce embryonic mortality after up to 5 consecutive passages. Allantoic fluid from the second passage was used in hemagglutination testing performed on chicken erythrocytes, which resulted in a titer of 64 hemagglutinating units. Avian paramyxovirus serotype 3 was identified in the allantoic fluid, and a reverse transcription polymerase chain reaction verified the isolate as APMV-3/parakeet. An eventual mortality rate of 70% occurred in the Neophema species, but a group of budgerigars (Melopsittacus undulatus) and parrotlets (Forpus species) kept in the same facility showed no clinical signs during the outbreak.

  20. DEVELOPMENT OF A NEW PROCESS FOR PURIFICATION OF CAPSULAR POLYSACCHARIDE FROM Streptococcus pneumoniae SEROTYPE 14

    Directory of Open Access Journals (Sweden)

    R. T. Zanardo

    Full Text Available Abstract The main virulence factor of Streptococcus pneumoniae is the capsular polysaccharide (PS, which is the antigen of all current vaccines that are prepared with PS purified from serotypes prevalent in the population. In this work, three purification strategies were evaluated and a new process was developed for purification of serotype 14 PS (PS14, responsible for 39.8% of diseases in children of 0-6 years old in Brazil. The developed method consists of cell separation by tangential microfiltration, concentration of the microfiltrate by tangential ultrafiltration (50 kDa, diafiltration in the presence of sodium dodecyl sulfate using a 30 kDa ultrafiltration membrane, precipitation with 5% trichloroacetic acid, precipitation with 20% and 60% ethanol, and anion exchange chromatography. The required purity regarding nucleic acids (≤ 2% and proteins (≤ 3% was achieved, resulting in a relative purity of 439 mg PS14/mg nucleic acids and 146 mg PS14/mg proteins. The final polysaccharide recovery was 65%, which is higher than the recovery of the majority of processes described in the literature.