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PubMedDate not supplied

Prevalence of antibodies to infectious bursal disease virus serotypes I and II in 75 Ohio chicken flocks.

Serum samples from 75 Ohio layer flocks were tested for antibodies to infectious bursal disease virus (IBDV) serotypes I and II using a virus-neutralization test. Infectious bursal disease had been diagnosed in three of the 75 flocks. Antibody titers to serotype I were detected in 77% of the flocks, and antibody titers to serotype II were detected in 47% of the flocks. Of the eight flocks known to have been vaccinated using a serotype I IBDV vaccine, all had antibody titers to serotype I, and four had antibody titers to serotype II. Eleven of 17 known unvaccinated flocks had antibodies to serotype I, and seven had antibodies to serotype II.

Animals↗
PubMedDate not supplied

[Serotype 5 pneumococcus in epidemiology and vaccine].

The Streptococcus pneumoniae serotype 5 is commonly isolated in human pathology. In France, it is the fourth pneumococcal serotype for acute pneumonia (9.1%) and bacteremia (6.9%). It appears to be more frequently encountered in Africa: in Dakar, this serotype is the third pneumococcal agent and is one of the more often isolated in meningitis; moreover, its is the third serotype isolated in Nigeria. In the intention of its incorporation in the yet available 14-valent pneumococcal vaccine, we have compared serological response and tolerance among four groups of adults: 1) the first group (23 persons) was only immunized by serotype 5 pneumococcal polysaccharide (50 micrograms); 2) the second group (23 persons) by the 15-valent pneumococcal vaccine (14-valent + serotype 5); 3) the third and the fourth groups (21 and 97 persons) were immunized by the 14-valent pneumococcal vaccine. By comparing the multiplying factors of geometrical means of antibodies levels measured by RIA, it appears that the pneumococcal polysaccharide serotype 5 is immunogenic, dispensed alone (first group) or associated with 14-valent pneumococcal vaccine (second group). No reciprocal interference can be detected between this polysaccharide and the other 14 polysaccharides. The tolerance of the serotype 5 polysaccharide is as good as that of these 14 antigens.

Aged↗
PubMed1994

[HCV-serotype and IFN response].

The relation between HCV-serotypes and response to interferon (IFN) in 114 cases with chronic hepatitis C treated with IFN-alpha were studied. HCV-serotypes; two distinct subgroups (serotype 1 and 2) of hepatitis C virus defined by antibodies directed to the putative core protein, were examined by ELISA developed by Machida et al. 1) Of 33 cases with serotype 2, 20 were responders, whereas, only 5 of 35 cases with serotype 1 responded to IFN therapy. 2) Of 23 cases with HCV-genotype III, 18 (78.3%) responded to IFN. Moreover, 12 (85.7%) of 14 cases who had serotype 2 were responders. On the other hand, only 17 (21.0%) cases with genotype II and 4 (12.1%) cases with serotype 1 responded to IFN. HCV-serotyping as well as HCV-genotyping in cases with chronic hepatitis C seems to be important in predicting the response to IFN therapy.

Adult↗
PubMed1995

[Assessment of the sensitivity to antifungal agents of clinical isolates of Candida albicans serotype A and B by the ATB Fungus method].

BACKGROUND: Candida albicans is the most frequently species isolated in patients with candidiasis. This species may be antigenically divided in serotypes A and B, which have a different pathogenic behavior and antifungal susceptibility pattern. METHODS: The antifungal susceptibility of 443 clinical isolates from both serotypes of C. albicans to 5-fluorocytosine (5FC), amphotericin B, nystatin, econazole, miconazole and ketoconazole has been tested by means of the ATB Fungus method. RESULTS: Both serotypes showed a similar in vitro susceptibility to amphotericin B, nystatin, econazole, miconazole and ketoconazole. All the isolates were susceptible to amphotericin B and nystatin. A small number of in vitro resistant isolates were observed to azole compounds. However, serotype B was significantly more resistant than serotype A (p = 0.0001) to 5FC. CONCLUSIONS: C. albicans serotype B shows a lower susceptibility than serotype A to 5FC, an antifungal product not marketed in Spain. Serotyping of C. albicans does not offer additional information on antifungal susceptibility of clinical isolates from this species.

Antifungal Agents↗
PubMed1994

Serotyping of pulmonary isolates of Candida albicans. A preliminary study.

A total of twenty strains of Candida albicans isolated from chronic pulmonary lesions were subjected to serotyping procedure adopting the conventional agglutination reactions. Prior to serotyping all the twenty strains were isolated on at least three different occasions and were identified by the standard accepted criteria (germ tube production, colony morphology on cornmeal Tween 80 agar and sugar fermentation reactions). Of the twenty strains, four strains belonged to serotype B and the remaining sixteen had the agglutination profile consistent with serotype A. The serotyping was undertaken with locally raised antisera against serotype A and serotype B. The proposed serotyping procedure has a definite potential in the epidemiological investigations of Candida albincans.

Agglutination↗
PubMedDate not supplied

Evaluation of persistence and distribution of Salmonella serotype isolation from poultry farms using drag-swab sampling.

The consistency and persistence of isolation of specific serotypes of Salmonella were evaluated on a 31-farm broiler complex following four complete sampling periods. A total of 25 different serotypes were isolated, with multiple serotypes and were frequently isolated simultaneously from individual farms. When the serotypes recovered from individual farms were further examined, common serotypes were isolated from individual farms on only seven occasions. Furthermore, on only five occasions were multiple serotypes recovered from individual farms on consecutive samplings. A casual association of common serotype isolations among farms with similar flock placement dates was observed in one sampling period. These results indicate little predictability or consistency of Salmonella serotype isolation on individual farms over time.

Animals↗
PubMed1996

Serotyping of Streptococcus pneumoniae by agglutination assays: a cost-effective technique for developing countries.

There is a need for additional data on the distribution of pneumococcal serotypes in developing countries. We report the use of a coagglutination (COA) and a latex agglutination (LA) test for serotyping Streptococcus pneumoniae which were evaluated using 114 clinical isolates in Vellore, India. In tests to serotype 30 fresh isolates of pneumococci from meningitis (8 isolates), bacteraemia/septicaemia (21 isolates) and peritonitis (1 isolate) cases, there was complete concordance among the three methods. An additional 20 isolates (11 from cerebrospinal fluid and 9 from blood cultures) were serotyped using both LA and COA, with full agreement between the results. With a further 30 isolates, there was 93% concordance for the COA types with serotypes assigned by a WHO reference laboratory. The COA and LA serotyping results were equivalent in accuracy to those obtained using quellung serotyping. Both these agglutination tests are rapid, valid, and relatively cheap, and with appropriate validation by reference laboratories they could be more widely used in developing countries to obtain local and regional data on pneumococcal serotype distribution.

Agglutination Tests↗
PubMed1998

Analysis of human rotavirus serotypes in children with acute diarrhoea in Chennai by monoclonal antibody based ELISA.

To determine the individual human rotavirus serotypes prevailing in Chennai, 345 stool specimens obtained from children with acute diarrhoea between March 1996 and November 1997, were screened for the presence of rotavirus by the standardized enzyme linked immunosorbent assay (ELISA). Of the 90 (26%) rotavirus positive specimens, 75 (83.3%) were subgrouped and 65 (72.2%) were serotyped with monoclonal antibody based ELISA. Of the 65 specimens that could be serotyped, 52.3 per cent belonged to serotype 2, 24.6 per cent were serotype 4, 15.4 per cent were serotype 1 and 7.7 per cent were serotype 3. Of the 75 specimens typed for their subgroup specificity, 50.7 per cent were subgroup I, 26.7 per cent were subgroup II, 18.7 per cent were equally specific to both subgroups I and II, 4 per cent belonged to nonsubgroups I and II. Our results indicate a predominance of serotype 2 virus. Unusual strain having both subgroups I and II specificity or neither specificity were also encountered.

Acute Disease↗
PubMed1998

[Promotion of phagocytosis and prevention of phagosome-lysosome (P-L) fusion in human peripheral blood monocytes by serotype specific glycopeptidolipid (GPL) antigen of Mycobacterium avium complex (MAC)].

Mycobacterium avium complex (MAC) is one of the most important opportunistic pathogens co-infected with HIV (AIDS) and a typical intracellular parasitic bacteria similar to M. tuberculosis. It is also noticed that M. avium infection causes immunosuppression especially in the cellular immunity of host animals, and specific serotype-subspecies such as sero-2, -4 or -8 can be isolated frequently in human infection. Furthermore, the prognosis after infection differs by the serotypes and serotype-4 shows heavy infection in general, while serotype-16 shows rapid improvement. Therefore, we have been interested in the immunomodifying activity of surface glycopeptidolipid (GPL) antigen. However, to date, no information has been available on the virulence factor of MAC related directly with intracellular bactericidal activity. Recently, we have tested the effect of various GPLs purified form MAC complex on phagocytic processes of human peripheral blood monocytes (PBMC). We have used GPL-coated heat-killed staphylococcal cells to be phagocytosed by PBMC, and phagosome-lysosome (P-L) fusion was estimated by the acridine orange staining of fused vesicles including bacteria. It was revealed that the serotype-4, -12 and -17 GPLs showed strong phagocytosis promotion and marked inhibition of P-L fusion, while serotype-9, -13, -16 and -19 GPLs showed neither promotion of phagocytosis, nor inhibition of P-L fusion in phagocytic cells. Serotype-5, -7, -8 and -10 GPLs showed stimulation of both phagocytosis and P-L fusion, concomitantly. These effects may be due to unknown interaction between specific carbohydrate chain of MAC and phagocytic cell membranes, and serotype-4, -12 and -17 GPLs may be one of the possible virulence factors in MAC.

Antigens, Bacterial↗
PubMed1984

Biosynthesis of reovirus-specified polypeptides. Multiplication rate but not yield of reovirus serotypes 1 and 3 correlates with the level of virus-mediated inhibition of cellular protein synthesis.

Kinetic analysis of mouse L fibroblast cells infected with reovirus revealed that serotypes 1 (Lang strain) and 3 (Dearing strain) differ significantly from each other in terms of their rates of multiplication and their effects on cellular protein synthesis. Serotype 1 did not significantly affect the synthesis of cellular polypeptides in monolayer cultures of L cells at late times after infection when virus-specific protein synthesis was at a maximum. By contrast, under identical culture conditions, serotype 3 essentially completely inhibited the synthesis of cellular polypeptides at late times when viral protein synthesis was at a maximum. The kinetics of virus-specific polypeptide synthesis and the production of infectious progeny were considerably slower for the serotype 1 Lang strain as compared to the serotype 3 Dearing strain, both at 30 and 37 degrees. However, the relative pattern of viral polypeptide synthesis and the final yield of infectious progeny did not differ significantly between serotypes 1 and 3. For both serotypes, the maximum yield of infectious progeny was obtained shortly after the maximum rate of viral polypeptide synthesis was reached. These results suggest that the rate of multiplication, but not the final yield, of reovirus serotypes 1 and 3 is related to the extent of virus-mediated inhibition of cellular protein synthesis.

Animals↗
PubMed2002

Evaluation of an enzyme-linked immunosorbent assay for serological surveillance of infection with Actinobacillus pleuropneumoniae serotype 5 in pig herds.

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 with Ap serotypes 5, 6, 7 and 12. Cross-reactions were shown in one pig from a herd naturally infected with Ap serotype 7 and in one pig from a herd naturally infected with Ap serotype 12. The herd sensitivities of the Ap5 ELISA and a complement fixation test (CFT) were both estimated to 1.0, on the basis of serum samples from six herds naturally infected with Ap serotype 5. The herd specificities of both tests were estimated to 0.98, based on serum samples from 123 pig herds (10 samples from each herd) from the Danish specific pathogen-free (SPF) programme for pig production.

Actinobacillus Infections↗
PubMed1989

Dengue virus-specific human T cell clones. Serotype crossreactive proliferation, interferon gamma production, and cytotoxic activity.

The severe complications of dengue virus infections, hemorrhagic manifestation and shock, are much more commonly observed during secondary infections caused by a different serotype of dengue virus than that which caused the primary infections. It has been speculated, therefore, that dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are caused by serotype crossreactive immunopathological mechanisms. We analyzed clones of dengue serotype crossreactive T lymphocytes derived from the PBMC of a donor who had been infected with dengue 3 virus. These PBMC responded best to dengue 3 antigen, but also responded to dengue 1, 2, and 4 antigens, in bulk culture proliferation assays. 12 dengue antigen-specific clones were established using a limiting dilution technique. All of the clones had CD3+ CD4+ CD8 phenotypes. Eight clones responded to dengue 1, 2, 3, and 4 antigens and are crossreactive, while four other clones responded predominantly to dengue 3 antigen. These results indicate that the serotype crossreactive dengue-specific T lymphocyte proliferation observed in bulk cultures reflects the crossreactive responses detected at the clonal level. Serotype crossreactive clones produced high titers of IFN-gamma after stimulation with dengue 3 antigens, and also produced IFN-gamma to lower levels after stimulation with dengue 1, 2, and 4 antigens. The crossreactive clones lysed autologous lymphoblastoid cell line (LCL) pulsed with dengue antigens, and the crossreactivity of CTL lysis by T cell clones was consistent with the crossreactivity observed in proliferation assays. Epidemiological studies have shown that secondary infections with dengue 2 virus cause DHF/DSS at a higher rate than the other serotypes. We hypothesized that the lysis of dengue virus-infected cells by CTL may lead to DHF/DSS; therefore, the clones were examined for cytotoxic activity against dengue 2 virus-infected LCL. All but one of the serotype crossreactive clones lysed dengue 2 virus-infected autologous LCL, and they did not lyse uninfected autologous LCL. The lysis of dengue antigen-pulsed or virus-infected LCL by the crossreactive CTL clones that we have examined is restricted by HLA DP or DQ antigens. These results indicate that primary dengue virus infections induce predominantly crossreactive memory CD4+ T lymphocytes. These crossreactive T lymphocytes proliferate and produce IFN-gamma after stimulation with a virus strain of another serotype, and demonstrate crossreactive cyotoxic activity against autologous cells infected with heterologous dengue viruses.(ABSTRACT TRUNCATED AT 400 WORDS)

Antigens, Differentiation, T-Lymphocyte↗
PubMed2002

Spatial and temporal circulation of dengue virus serotypes: a prospective study of primary school children in Kamphaeng Phet, Thailand.

Dengue virus occurs as four distinct serotypes, each of which causes epidemics throughout the tropical and subtropical regions of the world. Few studies have examined co-circulation of multiple dengue virus serotypes in a well-defined cohort population over time and their capacity to produce severe dengue disease. In this paper, the authors report the details and findings of the first 3 years (1998-2000) of an ongoing prospective study of dengue virus transmission and disease severity in a cohort of children in northern Thailand. A total of 108 dengue virus isolates were obtained from 167 acute dengue virus infections; 23% were DEN-1, 35% were DEN-2, 41% were DEN-3, and 1% were DEN-4. Despite the proximity of the schools, there was marked spatial and temporal clustering of transmission of each dengue serotype. Serotype-specific antibody levels prior to the dengue transmission season were not predictive of the incidence of dengue virus infections or the predominant serotype transmitted at individual schools. All dengue serotypes produced severe dengue illness, although DEN-3 produced more severe symptoms than the other dengue serotypes. The authors' findings emphasize the complexity of dengue serotype-specific virus transmission and severe dengue disease and have important implications for dengue control and vaccine development.

Acute Disease↗
PubMed1988

Analysis of serotype-specific neutralization epitopes on VP7 of human rotavirus by the use of neutralizing monoclonal antibodies and antigenic variants.

We analysed serotype-specific antigens of human rotavirus (HRV) by the use of neutralizing monoclonal antibodies (N-MAbs). The reactivity patterns of 12 serotype-specific N-MAbs against 15 HRV strains in a neutralization test revealed great intraserotypic antigenic variation especially those belonging to serotypes 2,3 and 4. On the basis of the protein specificity of the antibodies examined, it was suggested that whereas serotype 2-specific neutralization epitopes were present on both VP3 and VP7 outer capsid proteins, serotype 1-, 3- and 4-specific neutralization epitopes were located on VP7. Serotype-specific neutralization epitopes on VP7 of the serotype 1 HRV KU strain were analysed further using mutants of the KU strain resistant to different serotype 1-specific N-MAbs. The result suggested the presence of at least five operationally overlapping neutralization epitopes on VP7 of the KU strain, which collectively constituted a single large neutralization domain.

Antibodies, Monoclonal↗
PubMed1992

Virulence and adhesive properties of serotypes A and B of Candida albicans isolated from paediatric burn patients.

The virulence and adhesive properties of 50 isolates of Candida albicans serotypes A and B collected over 6 years from 48 paediatric burn patients were examined to provide more detailed information about candidal pathogenesis in burn patients and to examine the relevance of the commonly used epithelial cell adhesion assay for determining fungal virulence. The isolates represented a fair distribution of serotypes (29 isolates were serotype A and 21 isolates were serotype B) and a total of 28 serotype-biotype combinations were found; 32% of the serotype-biotype combinations appeared only once, while 44% of the isolates showed similar biotype tests for two of three digits. Adhesion of the isolates to plastic and to buccal epithelial cells (BECs) was examined and compared after growth in a chemically defined medium. There were significant differences in the adhesion of individual isolates to plastic or BECs, but no correlation was found between biotype and adhesiveness. Serotype B isolates were found to be more adhesive to BECs (p less than 0.05) but not to plastic. There was no apparent correlation between candidal adhesiveness and site of isolation from these patients (autografts, blood, faeces, throat swabs, tracheal aspirates, wounds and intravenous catheters), although isolates from catheters were generally less adhesive to epithelial cells. Virulence in a systemic infection mouse model revealed that there were significant differences in virulence between isolates, but no correlation was found between virulence and the biotype, serotype or site of isolation. Similarly, no correlation was found between virulence and adhesiveness or cell-surface hydrophobicity.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Antimicrobial susceptibility of Streptococcus pneumoniae: serotype distribution of penicillin-resistant strains in Spain.

This study examined the resistance to penicillin, tetracycline, erythromycin, and chloramphenicol of 318 pneumococcal strains isolated in Spanish hospitals from blood or cerebrospinal fluid of patients during 1979 to 1981. The serotypes of these strains were determined to discover whether a correlation between serotype and patterns of antibiotic resistance could be found. Seven and nine patterns of resistance were found in strains isolated from blood and cerebrospinal fluid, respectively; tetracycline was the most frequent pattern, followed by tetracycline associated with chloramphenicol. A random distribution of serotypes which was similar to the general distribution of serotypes was found for resistance to tetracycline and chloramphenicol, but penicillin-resistant strains were confined to seven serotypes. Thirty-six strains of penicillin-resistant pneumococci isolated from sources other than blood or cerebrospinal fluid were also serotyped. They represented the same serotypes, suggesting that serotype distribution among penicillin-resistant strains could be a manifestation of local epidemiological factors.

Chloramphenicol↗
PubMed1980

Serotypes of enterotoxigenic Escherichia coli isolated in the United States.

Strains of enterotoxigenic Escherichia coli isolated from humans in the United States were found in 11 of 16 serotypes that previously were documented in the international literature as associated with enterotoxin production. Of 68 strains belonging to these 11 serotypes, 28 (41%) were enterotoxigenic; none of 46 strains belonging to 5 other previously implicated serotypes was enterotoxigenic. Control cultures of various serotypes were selected for comparison and found to contain 0 to 7% enterotoxigenic E. coli. E. coli belonging to documented enterotoxin-associated serotypes, characterized by both O and H antigens, were selected for toxin testing to determine their prevalence and potential pathogenicity in this country. In this study, a strain possessing any combination of an enterotoxin-associated serotype O antigen and H antigen was more likely to be enterotoxigenic than strains possessing only the specific O antigen or H antigen or neither. Five E. coli strains belonging to undocumented enterotoxin-associated serotypes did contain a combination of previously reported enterotoxin-associated serotype O and H antigens and did produce enterotoxin.

Antigens, Bacterial↗
PubMed2006

Multiplex PCR-based method for identification of common clinical serotypes of Salmonella enterica subsp. enterica.

A multiplex PCR method has been developed to differentiate between the most common clinical serotypes of Salmonella enterica subsp. enterica encountered in Washington State and the United States in general. Six genetic loci from S. enterica serovar Typhimurium and four from S. enterica serovar Typhi were used to create an assay consisting of two five-plex PCRs. The assays gave reproducible results with 30 different serotypes that represent the most common clinical isolates of S. enterica subsp. enterica. Of these, 22 serotypes gave unique amplification patterns compared with each other and the other 8 serotypes were grouped into four pairs. These were further resolved by two additional PCRs. We compared the data from PCR serotyping with conventional serotyping and found that PCR serotyping was nearly as discriminatory as conventional serotyping was. The results from a blind test screening 111 clinical isolates revealed that 97% were correctly identified using the multiplex PCR assay. The assay can be easily performed on multiple samples with final results in less than 5 h and, in conjunction with pulsed-field gel electrophoresis, forms a very robust test method for the molecular subtyping of Salmonella enterica subsp. enterica.

Cost-Benefit Analysis↗