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Serotype, antimicrobial susceptibility, and pathogenicity of Erysipelothrix rhusiopathiae isolates from tonsils of apparently healthy slaughter pigs.

Erysipelothrix rhusiopathiae was isolated from tonsils of 63 (10.5%) of 600 apparently healthy slaughter pigs in the Kanto area of Japan in February and July 1984. The isolation rate was significantly higher during July than in February. Of these 63 isolates, 34 isolates (54.0%) were serotype 7, 20 isolates (31.7%) were serotype 2, 6 isolates (9.5%) were serotype 6, and 1 isolate (1.6%) each was serotype 11, 12, or 16. All isolates of serotypes 2, 6, 11, 12, and 16 were highly virulent for mice, whereas most isolates of serotype 7 were weakly virulent. In swine, all isolates of serotype 2 were highly virulent, capable of inducing generalized urticarial lesions with depression and anorexia. On the other hand, 37 of 43 isolates of serotypes other than 2 induced no clinical signs, and the remaining 6 isolates induced local urticarial lesions at the site of inoculation in swine. The MIC of dihydrostreptomycin ranged from 1.56 to 100 micrograms/ml. All of the dihydrostreptomycin-resistant strains belonged to serotype 2. The high virulence of E. rhusiopathiae strains of serotype 2 harbored in the tonsils suggests a possible role of such strains in the cause of swine erysipelas. In contrast, members of the other nonvirulent or weakly virulent group, mainly serotype 7 strains, were considered to be resident in porcine tonsils.

Animals↗

Relative frequencies of rotavirus serotypes 1, 2, 3, and 4 in Venezuelan infants with gastroenteritis.

We have used a recently developed monoclonal antibody enzyme-linked immunosorbent assay (K. Taniguchi, T. Urasawa, Y. Morita, H. B. Greenberg, and S. Urasawa, J. Infect. Dis. 155:1159-1166, 1987) for serotyping rotaviruses recovered from 134 Venezuelan infants over a period of 15 months. One hundred and nine of the specimens were typed with the following distribution: serotype 1, 48%; serotype 2, 16%; serotype 3, 22%; and serotype 4, 14%. Three specimens reacted with two different monoclonal antibodies. In addition, 6 specimens (5%) containing enough outer capsid antigen could not be typed; partial RNA sequence analysis of the glycoprotein gene from three of these six strains failed to reveal sequence differences with prototype strains that could be serotyped with the monoclonal antibodies. Variations in the recovery rates of the different serotypes were observed. Serotypes 2, 3, and 4 predominated at the beginning of the study, and serotype 1 predominated at the end of the study. Diarrheal illness appeared to be more prolonged in infants shedding rotavirus serotypes 1 and 3 than in those shedding serotypes 2 and 4.

Base Sequence↗

Serotype distribution of Campylobacter jejuni and Campylobacter coli isolated from hospitalized patients with diarrhea in central Australia.

Campylobacter jejuni and/or Campylobacter coli was cultured from 218 of 1,078 patients of all age groups admitted to Alice Springs Hospital, Alice Springs, central Australia, between July 1988 and June 1989 for treatment of diarrhea. One hundred sixty-six Campylobacter colonies from 127 patients were subjected to O serotyping by using the Penner typing scheme. All except 29 colonies could be serotyped. A total of 46 serotypes were identified, and the predominant serotypes were O:8, 17, O:22, O:1,44, and O:19. A large proportion of colonies reacted with more than one antiserum, and nine serotypes had antigenic compositions not observed previously. Several patients had multiple infections with more than one serotype, and some patients were shown for the first time to be infected with up to three different serotypes. Repeated reinfections with different serotypes were seen in some patients. In some patients, provided it was not due to reinfection with the same serotype, long-term excretion of the same serotype was seen, and for the first time, one patient showed evidence of excretion of the same serotype for up to 73 days.

Antigens, Bacterial↗

Distribution of serotypes of human rotavirus in different populations.

Serotyping is a useful tool to study the epidemiologic characteristics of rotaviruses in large populations and to assess the need for a vaccine to protect against all strains. By using an enzyme immunoassay with serotype-specific monoclonal antibodies to the four most common rotavirus serotypes, we analyzed 1,183 rotavirus-positive specimens from 16 stool collections in eight countries on four continents that were obtained from 1978 to 1989. Of the 926 strains (78%) that could be serotyped, 48% were serotype 1, 8% were serotype 2, 15% were serotype 3, and 7% were serotype 4. Twenty-two percent had insufficient numbers of double-shelled virus particles to react with the monoclonal antibody of the VP4 rotavirus protein and therefore could not be serotyped. Our results indicate that vaccines being developed must provide the greatest coverage against serotype 1 and that the serotype distribution cannot be predicted currently by the geographic area or prevalence in the preceding year.

Antibodies, Monoclonal↗

Serotype analysis of rotaviruses from different locations in Malaysia.

The distribution of rotavirus G (VP7) serotypes circulating in four locations in Malaysia, representing three geographical areas, was evaluated in 341 RNA-positive stool specimens obtained discontinuously between 1977 and 1988 from infants and young children under the age of five years who were hospitalized with acute gastroenteritis. A total of 306 specimens (256 stool suspensions and 50 that were adapted to growth in tissue culture) that were rotavirus positive by the confirmatory enzyme-linked immunosorbent assay (ELISA) were examined for serotype by ELISA utilizing monoclonal antibodies to rotavirus G serotype 1, 2, 3, 4, or 9. One hundred eighty (59%) of the 306 specimens could be serotyped; of these 180 specimens, 71% were serotype 4, 15% were serotype 1, 4% were serotype 2, and 4% were serotype 3. Serotype 9 rotavirus was not detected. Most (71%) of the specimens tested were obtained in 1988, when serotype 4 predominated in three locations in West Malaysia; no single serotype was predominant in a limited number of specimens from East Malaysia.

Antibodies, Monoclonal↗

Evaluation of serotype prediction by cpsA-cpsB gene polymorphism in Streptococcus pneumoniae.

New pneumococcal conjugate vaccines covering a limited number of serotypes are likely to come into widespread use over the next few years. It is unknown what effect this will have on the relative importance of different serotypes as causes of pneumococcal infection. Hence, it will be important to monitor serotype prevalence before, during, and after the introduction of new vaccines. We have investigated the ability of a PCR method based on polymorphisms in two genes common to the different capsule loci to predict the serotype of 93 clinical isolates of Streptococcus pneumoniae submitted to the Central Public Health Laboratory in 1997. Of 70 isolates with vaccine serotypes, 65 were predicted to belong to the correct serotype; this number was improved to 69 with the inclusion of two additional patterns to the database. Of 23 isolates with other serotypes, 19 were correctly predicted as non-vaccine serotypes, the discrepancy lying with four isolates of 6A (non-vaccine serotype) that were indistinguishable from isolates of 6B (vaccine serotype). In situations in which culture of the organism is not feasible, this method could potentially be applicable directly to clinical specimens and could be a valuable aid to the surveillance of pneumococcal serotypes.

Bacterial Capsules↗

Serotype identification of group B streptococci by PCR and sequencing.

Group B streptococcus (GBS; Streptococcus agalactiae) is the most common cause of neonatal and obstetric sepsis and is an increasingly important cause of septicemia in elderly individuals and immunocompromised patients. Ongoing surveillance to monitor GBS serotype distribution will be needed to guide the development and use of GBS conjugate vaccines. We designed sequencing primers based on the previously published sequences of the capsular polysaccharide (cps) gene clusters to further define partial cps gene clusters for eight of the nine GBS serotypes (serotypes Ia to VII). Subsequently, we designed and evaluated primers to identify serotypes Ia, Ib, III, IV, V, and VI directly by PCR and all eight serotypes (serotypes Ia to VII) by sequence heterogeneity. A total of 206 clinical GBS isolates were used to compare our molecular serotype (MS) identification method with conventional serotyping (CS). All clinical isolates were assigned an MS, whereas 188 of 206 (91.3%) were assigned a serotype by use of antisera. A small number of isolates (serosubtypes III-3 and III-4) showed different serotype specificities between PCR and sequencing, but the PCR results correlated with those obtained by CS. The overall agreement between the MS identification method and CS for isolates for which results of both tests were available was 100% (188 of 188 isolates). The MS identification method is a specific and practical alternative to conventional GBS serotyping and will facilitate epidemiological studies.

Bacterial Capsules↗

Serotyping of 467 Cryptococcus neoformans isolates from clinical and environmental sources in Brazil: analysis of host and regional patterns.

Cryptococcus neoformans is an important zoopathogen, and it is one of the most prevalent lethal mycotic agents. Its polysaccharide capsule, synthesized in vivo and in vitro, is a virulence factor, contains predominantly glucuronoxylomannan, and is responsible for the antigenic differentiation of serotypes A, B, C, D, and AD. A total of 467 isolates of C. neoformans obtained from clinical and environmental sources from Brazilian regions were studied serologically by using the Crypto Check Iatron RM 304-K kit. Serotyping of the clinical isolates showed the following prevalences of the serotypes: A (77.95%), followed by B (18.2%), AD (1.3%), D (0.4%), C (0.2%), and untypeable (1.93%). The epidemiology of serotype A in the Brazilian southern and southeastern regions reproduces the picture observed worldwide. In contrast, serotype B was the most frequent agent of cryptococcosis in the northeastern region, occurring nearly equally in male and female healthy hosts. Among the isolates from environmental sources, serotypes A and B were found to occur in the hollows of tropical trees of the genera Cassia, Ficus, and MOQUILLEA: The few isolates from Eucalyptus camaldulensis debris were serotypes A and B and untypeable. Overall, no association with a specific host tree was identified for these serotypes, denoting a distinct ecoepidemiological regional pattern. The one serotype C isolate was recovered from a human immunodeficiency virus-negative host. Serotype AD predominated over serotype D among both clinical and environmental isolates.

AIDS-Related Opportunistic Infections↗

Molecular serotyping of Klebsiella species isolates by restriction of the amplified capsular antigen gene cluster.

The objective of the present work was to develop a molecular method that would enable determination of the capsular serotypes of Klebsiella isolates without the use of antiserum. PCR amplification of the capsular antigen gene cluster (cps) was followed by digestion with the restriction enzyme HincII (cps PCR-restriction fragment length polymorphism [RFLP] analysis). The profiles (C patterns) obtained for 224 strains representing the 77 known K serotypes showed 3 to 13 fragments ranging in size from 0.2 to 4.4 kb. A total of 97 distinct C patterns were obtained; 100% of 61 pairs of samples tested twice showed reproducible C patterns. The C patterns were K-type specific; i.e., the C pattern(s) of any K serotype was distinct from the C patterns of all other K serotypes, with the only exceptions being serotypes K22 and K37, which are known to cross-react. For 12 of 17 K types for which at least two strains were included, C-pattern variations were found among strains with the same K serotype. Therefore, cps PCR-RFLP analysis has a higher discriminatory power than classical K serotyping. C-pattern identity was observed among strains with a given K type that were collected many years apart and from distinct sources, indicating C-pattern stability. Only 4.5% of the strains were nontypeable, because of unsuccessful PCR amplification (whereas 8 to 23% are nontypeable by classical K serotyping). Three of four noncapsulated strains analyzed showed recognizable C patterns. The K serotypes of 18 (82%) of 22 recent Klebsiella pneumoniae clinical isolates could be deduced from their C patterns. In conclusion, cps PCR-RFLP analysis allows determination of the K serotype, while it is easier to perform and more discriminatory than classical serotyping.

Animals↗

Serotype prevalence of occult pneumococcal bacteremia.

OBJECTIVE: The licensure and use of a pneumococcal conjugate vaccine that is immunogenic in children who are younger than 2 years may affect the epidemiology of occult bacteremia. This study was conducted to determine the serotype prevalence of Streptococcus pneumoniae isolates from children with occult bacteremia and to document the proportion that would be covered by the recently licensed heptavalent pneumococcal conjugate vaccine. METHODS: A cohort of 5901 children who were 2 to 24 months of age and had a temperature of >/=39.0 degrees C evaluated with a blood culture at an urban tertiary care children's hospital emergency department was studied to determine the prevalence of S pneumoniae serotypes. Patients were excluded if their immune system was suppressed, they had a diagnosis of a focal infection, they were evaluated by lumbar puncture, they were admitted to the hospital, or they died during initial evaluation. Blood cultures were inoculated into pediatric blood culture bottles and processed using an automated carbon dioxide monitoring system. All pneumococcal isolates were serotyped on the basis of capsular swelling with type-specific antisera (Quellung reaction). RESULTS: The study population consisted of 5901 patients. The overall rate of occult bacteremia was 1.9% (95% confidence interval [CI]: 1.5-2.3). S pneumoniae accounted for 92 of 111 isolates (82.9%; 95% CI: 74.6-89.4) in children with occult bacteremia. Eight pneumococcal serotypes were represented: 6A (2%), 9V (6%), 19F (6%), 18C (8%), 4 (9%), 6B (13%), 23F (15%), and 14 (42%). Serotypes 14, 6B, and 23F accounted for 69.3% (95% CI: 58.6-78.7) of typed isolates. In the cohort, 97.7% (95% CI: 92-99.7) of isolated serotypes are represented in the newly licensed heptavalent pneumococcal conjugate vaccine. The single isolated serotype that would not have been covered by the currently licensed heptavalent pneumococcal conjugate vaccine was 6A. CONCLUSIONS: S pneumoniae accounts for the vast majority of bacterial pathogens in children with occult bacteremia. As indicated by the results of this study, the heptavalent pneumococcal conjugate vaccine may prevent the majority of occult pneumococcal bacteremia episodes. The 2 cases of bacteremia with a serotype that would not have been included in the vaccine both were due to serotype 6A. It has been noted that there is potential nonvaccine serotype and subgroup cross-protection (6A from 6B) afforded to children who are immunized with the heptavalent vaccine. The high potential efficacy of the heptavalent pneumococcal conjugate vaccine for strains that cause occult bacteremia in our population may have a profound effect on the treatment of children with fever without a source. There has been an alarming and rapid emergence of antibiotic-resistant pneumococcal strains. Less pressure to use broad-spectrum antibiotics, which in turn causes further antibiotic resistance, should result. Laboratory testing and hospitalization also should be reduced. The prevalence rates determined by this study may be used as baseline data for comparison of serotype rates of occult pneumococcal bacteremia after widespread use of the heptavalent vaccine.

Bacteremia↗

Laboratory surveillance of invasive pneumococcal disease in Australia in 2001 to 2002--implications for vaccine serotype coverage.

This paper reports the results of comprehensive laboratory surveillance of invasive pneumococcal disease (IPD) in Australia during 2001 and 2002. The 7-valent conjugate pneumococcal vaccine was introduced for high risk paediatric groups, including Indigenous children, in late 2001. Of 1,355 isolates from non-Indigenous children, 86 per cent belonged to serotypes and 93 per cent to serogroups represented in the 7-valent pneumococcal conjugate vaccine. Thirteen per cent and 24 per cent of isolates had reduced susceptibility to penicillin and erythromycin, respectively and of these, more than 99 per cent belonged to serogroups represented in the 7-valent vaccine. Of the 1,504 isolates from non-Indigenous adults, 96 per cent belonged to serotypes included in the 23-valent polysaccharide vaccine; 14 per cent and 15 per cent had reduced susceptibility to penicillin and erythromycin, respectively and more than 95 per cent of these belonged to serotypes included in the 7-valent conjugate vaccine. In Western Australia and the Northern Territory (the only states for which Indigenous status was consistently available), there were 29 cases of IPD in Indigenous children, of which 21 were due to 7-valent vaccine serotypes in 2001, compared with 24 cases, including 10 due to vaccine serotypes, in 2002. This represents a statistically significant increase in the proportion of total isolates due to non-vaccine serotypes (chi2 = 3.93, p = 0.048) following the introduction of the 7-valent conjugate vaccine, principally due to serotypes 7F and 12F. The number of episodes due to penicillin resistant isolates decreased from nine in 2001 to two in 2002. Ninety per cent of isolates from Indigenous adults were included in the 23-valent polysaccharide vaccine and six per cent and five per cent had reduced susceptibility to penicillin and erythromycin, respectively. Conjugate pneumococcal vaccines can be expected to reduce the incidence of IPD due to vaccine serotypes in vaccinated children and potentially, their adult contacts. It may also impact favourably on the incidence of IPD due to penicillin and erythromycin resistant strains. Continued surveillance of both serotype distribution and antibiotic susceptibility are required to identify serotype replacement by non-vaccine serotypes and to monitor the overall impact of current and future vaccine programs on invasive pneumococcal disease in Australia.

Adolescent↗

Extrahepatic immunologic manifestations in chronic hepatitis C and hepatitis C virus serotypes.

OBJECTIVE: To determine, using a serotyping assay, whether the occurrence of extrahepatic immunologic disorders in patients with chronic hepatitis C is dependent on hepatitis C virus serotype. DESIGN: Prospective study. SETTING: Liver unit and virology laboratory of a university hospital. PATIENTS: 59 consecutive patients with chronic hepatitis C. MEASUREMENTS: Hepatitis C virus serotype was determined using a recently developed immunoenzymatic assay that detects antibodies directed to serotype-specific immunodominant epitopes. Cryoglobulin, rheumatoid factor, and numerous antitissue antibodies were sought. Biopsies of labial salivary glands were done in 49 of the 59 patients. RESULTS: Prevalence was 59% for serotype 1, 10% for serotype 2, 12% for serotype 3, and 3% for mixed infection. Fifteen percent of patients could not be serotyped. Cryoglobulinemia was found in 36% of patients and rheumatoid factor was found in the serum of 71%. At least one antitissue antibody was found in the serum of 41% of patients; salivary gland biopsy showed lymphocytic capillaritis in 49% of patients. These immunologic abnormalities were seen in patients infected with any of the three serotypes, and prevalences of the abnormalities did not differ significantly among patients infected with different serotypes. CONCLUSIONS: We confirm that the prevalence of extrahepatic immunologic abnormalities is high in patients with chronic hepatitis C. These abnormalities may occur in patients infected with any of the three major hepatitis C virus serotypes now present in developed countries.

Adolescent↗

[Distribution of Cryptococcus neoformans serotypes associated with human infections in Argentina].

C. neoformans (Cn) causes severe meningitis in immunocompromised patients, particularly those with AIDS. Little is known about Cn serotypes associated with human infections in Argentina due to the lack of antisera availability. The aim of this study was to produce these antisera, to serotype the Argentinean clinical isolates of Cn received at our laboratory from 1984 to 2001 and to evaluate the agreement of these results with the variety differentiation obtained with Canavanine-Glycine-Bromothymol Blue agar (CGB) medium. We studied 123 isolates recovered from first episodes of cryptococcosis from HIV-infected patients (85), non HIV-infected patients (6) and from other non specified patients (32). Of the isolates, 89% (110/123) were serotype A, 4% (5/123) corresponded to serotype D, 3% (3/129) were serotype AD, 3 isolates were untypable and 2 corresponded to serotype B. All the serotyped isolates agreed with the variety determined by CGB medium. These results indicate that, in our country, most cryptococcal infections in patients with AIDS are associated with serotype A (77/85), which agrees with international studies. In patients with other immunosuppressions, this serotype may be also predominant, although a low number of isolates were tested (4/6). Recovery of Cn serotype B in these clinical isolates suggests that studying the variety and their serotypes might be important to detect a probable epidemiological alteration.

AIDS-Related Opportunistic Infections↗

[Disribution of Streptococcus pneumoniae serotypes and serogroups among patients with invasive pneumococcal diseases in the Czech Republic in 1996-2003: background data for vaccination strategy].

STUDY OBJECTIVE: To map distribution of Streptococcus pneumoniae serotypes and serogroups in the Czech Republic in 1996-2003 in order to provide background data for effective strategy of vaccination with type specific pneumococcal conjugated vaccine. METHODS: Quellung typing with sera from the Statens Serum Institute (Denmark) was used to differentiate 1553 S. pneumoniae strains isolated from patients with invasive pneumococcal infections in the Czech Republic. RESULTS: Strains of serotypes 3, 19F, 9V, 23F, 1, 14 and 4 were most frequently isolated from clinical specimens (blood, cerebrospinal fluid, autopsy specimens, lung puncture aspirate, bronchoalveolar lavage fluid, sputum) of patients with invasive pneumococcal infections. Some serotypes were detected regardless of patient age (1, 3, 6A, 9V, 14, 19F and 23F), while serotype 6B was most frequent in the age group 0-2 years, serotypes 4, 6B, 7F and 18C were typically found in the age group >2-5 years and types 4, 7F, 8, 9N, 10A and 11A were common in patients aged >5 years. The 7-valent conjugated pneumococcal vaccine (PNCMR7) covers 63.1%, 62.3% and 34.3% of the serotypes identified in 152 patients aged 0-2 years, 168 patients aged >2-5 years and 1233 patients aged >5 years, respectively. It includes 38.3% of the serotypes identified among 1055 strains isolated from blood, cerebrospinal fluid and autopsy specimens regardless of patient age. Over the period moni- tored, the percentage of strains allocated to one of the serotypes included in the vaccine increased from 45.5% to 70.6%, from 54.3% to 38.7% and from 21.8% to 38.7% in patients aged 0-2 years, >2-5 years and >5 years, respectively, and from 30.0% to 39.4% for the isolates from blood, cerebrospinal fluid and autopsy specimens. A similar trend was found in the distribution of serogroups. These shifts can also be ascribed to the continuous increase in the percentages of strains of serotypes 4 (from 1.0% to 8.9%) and 9N (from 0.0% to 5.9%). CONCLUSION: The PNCRM7 vaccine is recommended for use in the Czech Republic in spite of the lower prevalence of vaccination serotypes among strains isolated from Czech patients with invasive pneumococcal infections which is a limitation to its efficacy. Nevertheless, results of the longterm monitoring of serotype distribution in the Czech Republic are suggestive of the need for inclusion of types 1 and 3 in the vaccine in the future.

Child, Preschool↗

Serotype distribution of Streptococcus pneumoniae isolates from ophthalmic and systemic infections and of commensal origin.

BACKGROUND AND OBJECTIVES: Information regarding serotype distributions of Streptococcus pneumoniae causing ophthalmic infections is scanty. This study was therefore undertaken to determine the antimicrobial susceptibility status and serotypes of S. pneumoniae isolated from various ophthalmic infections and to compare with those isolated from systemic infections and commensal nasopharyngeal flora. METHODS: Thirty eight of S. pneumoniae isolates from ophthalmic infections, 9 from systemic infections and 14 from the nasopharynx of apparently healthy school children were biochemically characterized and tested for in vitro antimicrobial susceptibility to various antibiotics. Serotyping of these 61 isolates was done by a rapid co-agglutination method. RESULTS: All the 61 isolates were sensitive to oxacillin (penicillin) and susceptibility against other antimicrobials was variable. No multidrug resistance was observed. The 38 ophthalmic isolates were distributed in 15 different serotypes. Most prevalent serotypes were 14, followed by 8 and 19F. The 9 systemic and 14 commensal. isolates of S. pneumoniae were distributed in 7 and 11 serotypes respectively. Three of the systemic and six of the commensal serotypes were observed in ophthalmic infections whereas four of the commensal serotypes were observed in systemic infections. INTERPRETATION AND CONCLUSION: Resistance to penicillin was not observed. In ophthalmic infections, a wide range of serotypes of S. pneumoniae were observed. More than half of the commensal serotypes obtained in the study as well as majority of the systemic serotypes were observed in ophthalmic infections.

Adolescent↗

Relationship between protective activity and antigen structure of Haemophilus paragallinarum serotypes 1 and 2.

The object in this investigation was to determine the relationship between protective activity and antigenic structure of Haemophilus paragallinarum, serotypes 1 and 2. A close relationship exists in both serotypes between protective activity and colonial phenotypic form (iridescent and noniridescent). Protective activities of both serotypes were related to a heat-labile, trypsin-sensitive (L) antigen of iridescent form that produced serotype-specific agglutinin to chickens. The chickens having the agglutinins were protected against challenge exposure with homologous strain, but not with heterologous strain. The chickens injected with unencapsulated organisms of noniridescent form that were derived from encapsulated organisms of iridescent form failed to produce both serotype-specific agglutinins and protection against challenge exposure with homologous strain. Most of the chickens injected with serotype 1 strain produced both hemagglutination-inhibition antibody and serotype 1-specific agglutinin, whereas those injected with serotype 2 produced serotype 2-specific agglutinin and protected against homologous challenge exposure. The protective activity was found in saline extract derived from encapsulated organisms of serotype 1, but was absent in those of serotype 2.

Agglutination Tests↗

Lipopolysaccharides of the Heddleston serotypes of Pasteurella multocida.

Lipopolysaccharides (LPS) were extracted from 13 of the 16 Heddleston serotypes of Pasteurella multocida by phenol-chloroform-petroleum ether (PCP). Serotypes 3, 9, and 13 were extracted only by phenol-water (PW). After extraction of LPS of serotype 9 by PW, an additional LPS was isolated by PCP. All LPS contained glucose, 2-keto-3-deoxyoctonate, and heptose. Two isomers of heptose, D-glycero-D-mannoheptose and L-glycero-D-mannoheptose, were found in serotypes 2 and 5. Antisera made against purified LPS of serotypes 2 and 5 reacted with both heat-stable antigens and LPS from serotypes 2 and 5 in the gel-diffusion precipitin test. Antisera against serotype 2 LPS protected turkeys against challenge with capsulated serotype 5, indicating that a structural relationship exists between LPS of strains that cause hemorrhagic septicemia and fowl cholera. Rhamnose was a component of serotype 9 LPS, and galactose was found in all LPS, except for serotype 11. The LPS of serotype 13 contained an isomer of heptose that has not been identified. The LPS had buoyant densities in CsCl of 1.40 +/- 0.0148 g/ml, and all hemagglutinated chicken and turkey, but not sheep or horse, RBC.

Animals↗

Serotypes and electropherotypes of human rotavirus detected in the city of São Luís (MA), Brazil.

A total of 22 (65%) of 34 representative rotavirus-positive specimens from infants with acute gastroenteritis were electropherotyped (RNA genome segments) and serotyped using an enzyme immunoassay with monoclonal antibodies (ELISA with MAbs). Serotype 3 was predominant during the 10-month study period (41%), followed by serotype 1 (27%) and serotype 4 (9%). Serotype 2 was not found. Rotavirus strains were grouped into 3 major electropherotypes designated V, W and Z, each corresponding to a single serotype, i.e., serotypes 1, 3 and 4, respectively. Three strains that could not be typed by the serologic technique showed the W electrophoretic profile. The relative migration of the gene segments 7-9 was the main feature distinguishing the predominant serotype 3 from the other serotypes. The migration of segments 2 and 5 was also important for differentiating serotype 4 strains. The present study strengthens the view that electropherotyping, when used in conjunction with serotyping, can help characterize atypical and unusual strains, as well as rotaviruses that cannot be typed by the serologic technique.

Acute Disease↗