Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “serotype”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 685 records · Page 38Linked to original sources
PubMed2005

Middle ear fluid Streptococcus pneumoniae serotype distribution in Costa Rican children with otitis media.

BACKGROUND: Streptococcus pneumoniae conjugate vaccine became available in Costa Rica in 2004. Previous S. pneumoniae middle ear fluid (MEF) data obtained during the period 1999-2001 from Costa Rican children indicated that serotype 19F was the most common type (75%), but more recently other serotypes have become more prevalent. OBJECTIVES: To establish the most common S. pneumoniae serotypes present in the MEF of Costa Rican children with otitis media (OM) and to analyze serotype distribution by demographic factors, disease distribution and antimicrobial susceptibility patterns and assess the potential protection provided by the new conjugated heptavalent S. pneumoniae vaccine in Costa Rican children with OM. METHODS: During 2002 and 2003, 69 S. pneumoniae isolates were obtained from the MEF of Costa Rican children, ages 3-49 months, with OM. Serotyping was performed by the quellung reaction with antisera from Statens Serum Institute, Copenhagen, Denmark. RESULTS: The most common S. pneumoniae serotypes isolated were 19F (26.1%), 6B (14.5%), 9V (8.7%), 16F (8.7%), 14 (5.8%), 23F (5.8%), 3 (5.8%) and 6A (5.8%). Serotype distribution was similar among children younger than 24 months of age or 24 months of age or older and by disease distribution. There was a tendency towards more penicillin- and trimethoprim-sulfamethoxazole-nonsusceptible isolates among vaccine-type strains than among non-vaccine type strains. CONCLUSIONS: The serotype distribution of S. pneumoniae causing pediatric OM in Costa Rica is similar to those reported from developed countries. The current heptavalent pneumococcal conjugate vaccine covers 74% of OM episodes in Costa Rican children.

Anti-Bacterial Agents↗
PubMed1998

Phylogenetic diversity of Streptococcus suis strains of various serotypes as revealed by 16S rRNA gene sequence comparison.

The 16S rRNA gene sequences of reference strains of Streptococcus suis serotypes 1-34 and 1/2 were determined. A comparative sequence analysis showed that the degree of sequence similarity between S. suis reference strains ranged from 93.94 to 100%. A dendrogram was constructed from the similarity matrix. Thirty-two strains representing 32 serotypes fell into a major group divided into three clusters. The other strains, S. suis serotypes 32, 33 and 34, were more distant. Biochemical characterization of the six more distant strains, including S. suis serotypes 20, 22, 26, 32, 33 and 34, revealed a profile similar to that of other S. suis serotypes. Comparison of the 16S rRNA gene sequences of S. suis reference strains with sequences of other members of the genus Streptococcus indicated that, with the exception of S. suis serotypes 32, 33 and 34, reference strains did not cluster with any other species in the genus. In conclusion, 16S rRNA gene sequence analysis defined a major group of S. suis reference strains which were very closely related and a higher divergence for S. suis serotypes 32, 33 and 34. However, to date, there is no strong evidence to reclassify strains of these serotypes in another species.

Animals↗
PubMed1977

Heterotypic exclusion between vesicular stomatitis viruses of the New Jersey and Indiana serotypes.

Co-infection of cells with vesicular stomatitis viruses of the Indiana and New Jersey serotypes results in interference. Using specifically-labelled immunofluorescent antibodies, it was demonstrated that within any one co-infected cell, one virus serotype replicated to the relative exclusion of the other serotype. This result was further substantiated by an examination of the virus serotypes released by infectious centres co-infected with both viruses. Dominance of one serotype over the other was shown to be a function of the relative multiplicity of the two viruses. Superinfection by the second serotype at a higher multiplicity resulted in dominance by the second virus during the early period (up to 1-5 h) post-infection. After this time, the minority virus was able to overcome this dominance. Dominance of the majority virus was also abolished by u.v; inactivation. Cell protein synthesis appeared to be less affected in cells infected with both serotypes than when infection was with a single serotype.

Fluorescent Antibody Technique↗
PubMed1987

Serotypes of Campylobacter jejuni isolated from patients attending a diarrhoeal disease hospital in urban Bangladesh.

The serotypes of strains of Campylobacter jejuni isolated from patients attending the International Center for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka, and from animals were ascertained by Penner and Hennessy's (1980) serotyping scheme. Of 102 isolates from man, 74% were typable and serotypes 53, 15 and 22 predominated. Of 26 isolates from animals, 65% were typable and serotypes 15 and 53 occurred frequently. The diarrhoeal illnesses associated with different serotypes were similar. In one-third of cases other enteropathogens were present. C. jejuni was isolated from 7% of patients tested in a 4% sampling system during 1983, and the prevalent serotypes appeared in most months. It is concluded that C. jejuni is a common enteropathogen in Bangladesh, that a few serotypes predominate among isolates from both man and animals, and that serotype does not determine clinical symptoms.

Adolescent↗
PubMed1999

Comparison of a commercial test for serotyping heat-stable antigens of Campylobacter jejuni with genotyping by pulsed-field gel electrophoresis.

A new commercial serotyping set based on heat-stable Penner's antigens was compared with pulsed-field gel electrophoresis (PFGE) with SmaI and SacII restriction endonucleases. Among 50 isolates of Campylobacter jejuni from Finnish patients, which represented predominant PFGE patterns selected from isolates from sporadic cases and isolates associated with small outbreaks, 11 different serotypes were demonstrated from 43 typable isolates. Several PFGE patterns could be found within one serotype; on the other hand, several serotypes could be demonstrated within one PFGE type. Most isolates originated from sporadic cases; however, some isolates were epidemiologically associated and showed identical serotypes and PFGE patterns. Although the new serotyping set would have been useful in the few epidemic cases studied, several isolates (14%) representing the major PFGE patterns remained untypable or gave weakly positive agglutination reactions only suggesting a plausible serotype (18%). This might restrict the use of the novel serotyping set, at least in Finland.

Adolescent↗
PubMed1996

Multiply antibiotic-resistant Streptococcus pneumoniae recovered from Spanish hospitals (1988-1994): novel major clones of serotypes 14, 19F and 15F.

We analysed a collection of 95 multiply antibiotic-resistant pneumococci, recovered since 1988 from 14 Spanish hospitals, that have MICs > or = 0.25 microgram benzylpenicillin ml-1. The majority of the isolates were of serogroups 14, 23, 6, 19 and 15, which are currently the serogroups mainly associated with multiresistance in Spain. All of the serogroup 23 isolates were members of the major Spanish serotype 23F multiresistant clone. Similarly, most of the serogroup 6 isolates were members of the major multiresistant serotype 6B clone, or variants of this clone. Eighteen of the 24 isolates of serogroup 19 were members of a highly penicillin-resistant clone that appears to be a serotype 19F variant of the major Spanish serotype 23F multiresistant clone. Eighteen of the 25 isolates of serotype 14 were members of a previously uncharacterized highly penicillin-resistant clone. Thirteen of the 16 isolates of serogroup 15 were members of a single previously unreported clone of serotype 15F that had moderate levels of resistance to penicillin. Approximately 65% of the multiresistant pneumococci that are currently circulating in Spain were members of the three new clones of serotype 14, 15F and 19F that we describe here, or the previously described serotype 6B and 23F clones. The other 35% of isolates were minor variants of the major clones, unrelated minor clones, and unique isolates, many of which appeared to have arisen by horizontal gene transfer events.

Bacterial Proteins↗
PubMed2003

A first full outer capsid protein sequence data-set in the Orbivirus genus (family Reoviridae): cloning, sequencing, expression and analysis of a complete set of full-length outer capsid VP2 genes of the nine African horsesickness virus serotypes.

The outer capsid protein VP2 of African horsesickness virus (AHSV) is a major protective antigen. We have cloned full-length VP2 genes from the reference strains of each of the nine AHSV serotypes. Baculovirus recombinants expressing the cloned VP2 genes of serotypes 1, 2, 4, 6, 7 and 8 were constructed, confirming that they all have full open reading frames. This work completes the cloning and expression of the first full set of AHSV VP2 genes. The clones of VP2 genes of serotypes 1, 2, 5, 7 and 8 were sequenced and their amino acid sequences were deduced. Our sequencing data, together with that of the published VP2 genes of serotypes 3, 4, 6 and 9, were used to generate the first complete sequence analysis of all the (sero)types for a species of the Orbivirus genus. Multiple alignment of the VP2 protein sequences showed that homology between all nine AHSV serotypes varied between 47.6 % and 71.4 %, indicating that VP2 is the most variable AHSV protein. Phylogenetic analysis grouped together the AHSV VP2s of serotypes that cross-react serologically. Low identity between serotypes was demonstrated for specific regions within the VP2 amino acid sequences that have been shown to be antigenic and play a role in virus neutralization. The data presented here impact on the development of new vaccines, the identification and characterization of antigenic regions, the development of more rapid molecular methods for serotype identification and the generation of comprehensive databases to support the diagnosis, epidemiology and surveillance of AHS.

African Horse Sickness↗
PubMed1985

Chemical characterization of capsular polysaccharide from Cryptococcus neoformans serotype A-D.

During a study of serotyping of Cryptococcus neoformans, we found that the type strain of C. neoformans (CBS 132) was serotype A-D. This strain agglutinated with both factor 7 serum (specific for serotype A) and factor 8 serum (specific for serotype D) in our serotyping system. Therefore, we investigated the chemical structure of the antigenic capsular polysaccharide of this strain. The soluble capsular polysaccharide was obtained from the culture supernatant fluid by precipitation with ethanol. Column chromatography of the polysaccharide on DEAE-cellulose yielded three fractions (F-1 to F-3). The major antigenic activity was found in the F-3 fraction. The results obtained by methylation analysis, controlled Smith degradation-methylation analysis, partial acid hydrolysis, and other structural studies of F-3 polysaccharide indicated that the polysaccharide contains mannose, xylose, and glucuronic acid at a ratio of 7:2:2, and has a backbone of alpha (1-3)-linked D-mannopyranoside residues with a single branch of beta (1-2)-xylose and glucuronic acid. The ratio of mannose residues with or without a branch in the F-3 polysaccharide was 4:3 and its molecular weight calculated from the average of the degree of polymerization was 46,500 daltons. These results indicate that the chemical structure of the capsular polysaccharide of serotype A-D is very similar to those from serotypes A and D, suggesting that small differences in the molar ratio and pattern of linkage of monosaccharides in the branch of the polysaccharides of the three serotypes may be responsible for their different specificities.

Antigens, Bacterial↗
PubMed1993

Mutations in the rfbT gene are responsible for the Ogawa to inaba serotype conversion in Vibrio cholerae O1.

In cultures of Vibrio cholerae strains of Ogawa serotype, variant strains which had undergone serotype conversion from Ogawa to Inaba were identified. The rfbT genes cloned from the parent strains were found to produce a 31-kDa protein in the maxicell system, and to cause serotype conversion when introduced into E. coli cells expressing Inaba serotype specificity. On the other hand, rfbT genes cloned from the variant strains neither produced the 31-kDa protein nor caused serotype conversion. Nucleotide sequence of these rfbT genes as well as those of two clinical Vibrio cholerae strains of Inaba serotype revealed that mutations causing premature termination of their rfbT genes were invariably present in strains expressing Inaba serotype specificity. The results strongly suggested that genetic alteration of the rfbT gene is responsible for serotype conversion of Vibrio cholerae O1.

Amino Acid Sequence↗
PubMed1998

Determination of serotypes of astroviruses by reverse transcription-polymerase chain reaction and homologies of the types by the sequencing of Japanese isolates.

Human standard astroviruses, serotypes 1 to 7, and 35 Japanese isolates were typed by reverse transcription and polymerase chain reaction (RT-PCR) with serotype-specific primers for the first time. The results were identical with those obtained by enzyme immunoassay with serotype-specific polyclonal antibodies, a method which has already been reported. RT-PCR with serotype-specific primers is useful for epidemiological studies of astroviruses where serotype-specific polyclonal antibodies are not available. Two parts of the capsid region, N terminus and C terminus, were sequenced. Serotypes differed in those regions. The N terminus differed less than the C terminus between serotypes. Both the N terminus and C terminus were similar intraserotypically with the exception of serotype-4 isolates which could be divided into A and B subgroups on the basis of their C terminus sequences, which were not known previously.

Amino Acid Sequence↗
PubMed1993

Structural variation in the O-specific polysaccharides of Klebsiella pneumoniae serotype O1 and O8 lipopolysaccharide: evidence for clonal diversity in rfb genes.

The O-polysaccharide fraction of the lipopolysaccharide from Klebsiella pneumoniae serotype O8 was found to comprise two galactose-containing homopolymers. Structural analysis, using chemical and high-field nuclear magnetic resonance (NMR) techniques, established that the K. pneumoniae O8 polysaccharides are composed of the linear, disaccharide repeating units [formula: see text] K. pneumoniae O8 mutant RFK-1 was isolated by resistance to phage KO1-2; strain RFK-1 expressed only D-galactan I-OAc. The 1H- and 13C-NMR resonances from this O-polysaccharide indicate that all of the O-acetyl groups within the K. pneumoniae O8 polysaccharide are carried on D-galactan I and O-acetylation occurs only on the beta-D-galactofuranose residues; 60% of the available beta-D-galactofuranose residues are non-acetylated. The O-acetylation of the remaining residues is equally distributed between the O-2 and O-6 positions. The carbohydrate backbone structures in the O8 polysaccharide are identical to D-galactan I and II expressed by K. pneumoniae O1, accounting for the antigenic cross-reaction between strains belonging to serotypes O1 and O8. However, the O1 polysaccharides are not acetylated and the O-acetyl groups present in the K. pneumoniae serotype O8 polysaccharides provide a structural basis for their recognition as distinct serotypes. The rfb (O-polysaccharide biosynthesis) gene cluster of K. pneumoniae serotype O1 determines the synthesis of D-galactan I. rfbKpO1-specific gene probes were used to examine conservation in the rfb gene clusters of other K. pneumoniae serotypes which produce D-galactan I. Six O1 strains were examined and all showed hybridization with rfbKpO1 probes under conditions of high stringency. Three serotype O2 strains produce D-galactan I and these strains also contained DNA sequences recognized by rfbKpO1 probes under high stringency. The physical maps of these homologous rfb chromosomal regions showed some polymorphism. Surprisingly, the rfbKpO8 region from K. pneumoniae serotype O8 was only recognized by rfbKpO1 probes under low-stringency hybridization conditions, providing evidence for two substantially different clonal groups of rfb genes from K. pneumoniae strains with structurally related O-antigens.

Acetylation↗
PubMed1990

N-acetyl-L-galactosaminuronic acid as an epitope common to the O-polysaccharides of Pseudomonas aeruginosa serotype A and H (Homma) recognized by a protective human monoclonal antibody.

We have established a human--mouse heterohybridoma cell line producing a human monoclonal antibody TS-3G2 (IgG gamma 1, K). This monoclonal antibody specifically bound to O-polysaccharides belonging to plural Pseudomonas aeruginosa Homma serotypes, A and H, in contrast to serotype-specific monoclonal antibody which exclusively bound to strains belonging to a single specific serotype. The binding affinity for serotype A strains was higher than that for serotype H strains. Competitive enzyme immunoassay experiments with O-polysaccharide preparations derived from IID 1001, NCTC 8505 (serotype A) and IID 1009 (serotype H) and their derivatives demonstrated that the N-acetyl-L-galactosaminuronic acid residue in O-polysaccharide was essentially involved in the epitope for TS-3G2. Furthermore, a 6-deoxy-hexosamine residue neighboring the reducing terminal of N-acetyl-L-galactosaminuronic acid residues was also concerned with the epitope to some extent. In the experimental infection model of normal mice, the monoclonal antibody TS-3G2 showed a protective activity against both strains of serotype A and H.

Animals↗
PubMed1992

Serotyping and antigenic comparison of some animal rotaviruses isolated in China.

Eight strains of rotaviruses isolated from diarrheal animals (4 from calves and 4 from piglets) in China were compared by serotyping with reference animal rotavirus strains (bovine NCDV, porcine OSU and simian SA-11 and human rotavirus Wa strain). Two-way cross neutralization test showed no antigenic difference between all 4 local strains of bovine rotavirus (BRV007, BRV014, HN-7 and BRV6555) and reference NCDV, so they belonged to rotavirus serotype 6 (bovine rotavirus serotype 1 or NCDV-serotype). Meanwhile, the four strains of Chinese porcine rotavirus could be determined into 2 different serotypes. One (Li99) was neutralised to a high titer with the antiserum against reference OSU virus and probably related to OSU (serotype 5 or porcine serotype 1). The other three strains (Lin71, Nan86 and Jiang150) were antigenically obviously different from Li99 and did not react with the antiserum against OSU. They were tentatively considered as porcine rotavirus serotype 2. All the strains of bovine and porcine rotavirus did not cross-neutralise with simian SA-11 and human Wa strain. There was also no antigenic relationship between bovine rotaviruses and porcine rotaviruses.

Animals↗
PubMed2006

Drug-resistant genes and serotypes of pneumococcal strains of community-acquired pneumonia among adults in Japan.

BACKGROUND: A high frequency of drug-resistant pneumococci has been reported in Asian countries. Few data on the drug-resistance or serotype of pneumococcal strains responsible for community-acquired pneumonia (CAP), however, are available for the past two decades in Japan. METHODOLOGY: Susceptibility to antibiotics and the genotype of antibiotic-resistant genes and serotypes of Streptococcus pneumoniae isolates from 114 adult patients with CAP were examined in a nationwide study in Japan between 2001 and 2003. RESULTS: Most of the cases were non-bacteraemic pneumonia and the case fatality rate was 4.4%. The most frequent genotype of the pbp gene was pbp1a + 2x + 2b (gPRSP; 36.8%) followed by pbp 2x (28.1%) and of the macrolide-resistant gene, it was ermB (50.0%). The most common serotype was 19F (29.1%), followed by serotype 23F (13.2%), 6B (12.3%) and 3 (11.4%). The coverage of serotypes of isolates by a 23-valent pneumococcal polysaccharide vaccine (PPV) would be 82.5% in these patients with CAP. Most of strains with serotypes 19F and 23F were gPRSP. A cluster of serotype 3 strains associated with the pbp 2x and ermB gene was also noted. CONCLUSION: A high frequency of altered pbp gene mutations or of macrolide-related genes and a high serotype coverage by the 23-valent PPV found in our study of pneumococcal pneumonia facilitates attempts to increase the coverage rate of the 23-valent PPV in adults older than 65 years in Japan.

Adult↗
PubMed1996

Identification of flagellar (H) antigenic subfactors in Bacillus thuringiensis H serotypes 10, 18 and 24 isolated in Japan.

A total of 95 Bacillus thuringiensis strains isolated from Japan and belonging to H serotypes 10, 18 and 24, were examined for their H antigenic subfactors. Of 84 H serotype 10 isolates, 83 were identified as the H serotype 10a: 10b (serovar darmstadiensis) and only one isolate was assigned to the H serotype 10a: 10c (serovar londrina). Among five isolates belonging to the H serotype 18, three were allocated to the H serotype 18a: 18b (serovar kumamotoensis), while two isolates did not react to antisera against the two known H antigenic subfactors, 18b and 18c. All of the six H serotype 24 isolates were assigned to the H serotype 24a: 24b (serovar neoleonensis).

Antigens, Bacterial↗
PubMed1996

Characterization of monoclonal antibodies that recognize common epitopes located on O antigen of lipopolysaccharide of serotypes 1, 9 and 11 of Actinobacillus pleuropneumoniae.

Seven murine monoclonal antibodies (mAbs) against serotype 1 of Actinobacillus (Haemophilus) pleuropneumoniae (reference strain Shope 4074) were produced and characterized. All hybridomas secreting mAbs were reactive with whole-cell antigens from reference strains of serotypes 1, 9 and 11, except for mAb 5D6 that failed to recognized serotype 9. They did not react with other taxonomically related Gram-negative organisms tested. The predominant isotype was immunoglobulin (Ig) M, although IgG2a, IgG2b, and IgG3 were also obtained. The epitopes identified by these mAbs were resistant to proteinase K treatment and boiling in the presence of sodium dodecyl sulfate and reducing conditions; however, they were sensitive to sodium periodate treatment. Enhanced chemiluminescence-immunodetection assay showed that mAbs could be divided in two groups according to the patterns of immunoreaction observed. Group 1 (mAbs 3E10, 4B7, 9H5 and 11C3) recognized a ladder-like banding profile consistent with the O antigen of lipopolysaccharide (LPS) from smooth strains. Group II (mAbs 3B10 and 9H1) recognized a long smear of high molecular weight which ranged from 60 to 200 kDa. The mAbs were tested against 96 field isolates belonging to serotypes 1, 5, 9, 11 and 12, which had previously been classified by a combination of serological techniques based on polyclonal rabbit sera (counterimmunoelectrophoresis, immunodiffusion and coagglutination). The panel of mAbs identified all isolates of serotypes 9 and 11, but only 66% of those belonging to serotype 1. This may suggest the existence of antigenic heterogeneity among isolates of A. pleuropneumoniae serotype 1. These mAbs reacted with epitopes common to serotypes 1, 9 and 11 of Actinobacillus pleuropneumoniae which were located on the O antigen of LPS.

Actinobacillus pleuropneumoniae↗
PubMed1985

Serotyping of Campylobacter jejuni isolated from sporadic cases and outbreaks in northern Norway.

In the northern regions of Norway, 123 cases of Campylobacter jejuni gastroenteritis were either sporadic infections or due to five separate outbreaks during 1980-83. Using a serotyping scheme based on thermostable antigens and the passive haemagglutination technique, 92 isolates were serotyped. Excluding duplicates from the outbreaks, the serotype distribution based on 79 isolates showed that serotypes 6, 7 and 12, 40 were the most frequent in occurrence. Each included 11 (13.9%) of the isolates and each serotype was also identified twice as the epidemic strain in four different outbreaks. A fifth outbreak strain was serotype 13, 16, 50. The number of isolates that reacted in one or more antisera of the cross reacting group of serotypes 4, 13, 16, 43 and 50 was 21 (26.6%). The other 23 isolates fell into 19 other serotypes and 13 (16.5%) were untypable.

Campylobacter Infections↗
PubMed1992

[Detection and serotyping of HRVs collected from children with acute gastroenteritis in winter of 1986 to 1991].

Fecal samples from sporadic acute gastroenteritis patients who visited at a pediatrician during five consecutive winter seasons in Kurume City located at north part of Kyushu district. Fecal samples were subjected to detection of rotavirus and other viruses and study of yearly changes in serotype of rotavirus. The rate of group A rotavirus positives in third winter and other consecutive winters were 12.5%, 40 to 65%, respectively. 60% specimens were successfully serotyped: 58% was serotype 1.22% was serotype 3.6% was serotype 2, and 14% was serotype 4. The dominant serotype in first, fourth and fifth winter was type 1. However in second winter each serotype of rotavirus was almost equally detected. During five consecutive winters six patients visited at the same pediatrician twice more than two months interval. They all had acute gastrointestinal symptoms. In six patients rotavirus was detective just once.

Acute Disease↗