Different Serotypes Of Group Research Articles

The correlation between expression of sip protein in different serotypes of group b streptococcus and diagnosis

Since the surface immunogenic protein (Sip) of group B streptococcus was identified, it's immunogenicity and its potential as a universal vaccine candidate has been evaluated extensively. We developed recombinant Sip protein and used it for monoclonal antibody generation to develop immunochromatographic test kit for GBS detection. The test of bacteria and culture media revealed the correlation between Sip protein expression and diagnosis discrepancy, which has never been reported. Furthermore, not only the surface accessibility of the Sip protein may vary from strains or serotypes; the secretion level of Sip protein may also vary.

Production and characterization of VP6-specific monoclonal antibodies against bovine group C rotavirus

Rotaviruses are enteric pathogens causing acute watery dehydrating diarrhea in humans and animals. The importance of group C rotavirus (GpC-RV) infections has not been established as the studies on the GpC-RV have been hampered by the lack of an in vitro culture system. However, diarrheal diseases associated with GpC-RV have been gradually increasing worldwide. In this study, VP6 gene of bovine GpC-RV Korean isolate was expressed, and monoclonal antibodies (mAbs) against VP6 were produced and characterized. The VP6 gene was cloned and expressed based on a baculovirus expression system. Indirect fluorescence antibody (IFA), polymer chain reaction (PCR), and Western blot assays were used to confirm expression of VP6 gene synthesized by the recombinant baculovirus. Eleven mAbs against VP6 were produced using expressed VP6. Cross-reactivity of the mAbs was assessed with recombinant VP6 proteins from porcine GpC-RV and human GpA-RV, or different serotypes of group A rotavirus strains by IFA test. Some mAbs reacted with intact porcine GpC-RV Cowden strain as well as bovine GpC-RV VP6 recombinant baculoviruses, but not with human and animal GpA-RV strains. The VP6-specific mAbs might be useful to develop immunodiagnostic tests such as rapid diagnostic kit, IFA and enzyme-linked immunosorbent assay (ELISA) for detection of GpC-RV.

New 30-valent M protein-based vaccine evokes cross-opsonic antibodies against non-vaccine serotypes of group A streptococci

Our previous studies have shown that recombinant multivalent vaccines containing amino-terminal M protein fragments from as many as 26 different serotypes of group A streptococci (GAS) evoked opsonic antibodies in animals and humans. In the present study, we constructed a new 30-valent vaccine containing M protein peptides from GAS serotypes prevalent in North America and Europe. The vaccine was immunogenic in rabbits and evoked bactericidal antibodies against all 30 vaccine serotypes of GAS. In addition, the vaccine antisera also contained significant levels of bactericidal antibodies against 24 of 40 non-vaccine serotypes of GAS. These results indicate that the potential efficacy of the new multivalent vaccine may be greater than predicted based on the "type-specific" M peptides represented.

Antibacterial activities of the cathelicidins prophenin (residues 62 to 79) and LL-37 in the presence of a lung surfactant preparation.

The antibacterial activities of the cathelicidin peptides LL-37 and an 18-residue C-terminal fragment of prophenin, corresponding to positions 62 to 79 of native prophenin (PF-18), were analyzed in the presence of a modified surfactant preparation isolated from minced porcine lungs. At low micromolar concentrations, both LL-37 and PF-18 showed significant activities against different serotypes of group B streptococci, with LL-37 being more active on a molar basis. The surfactant preparation at a concentration of 10 mg/ml partly blocked the antibacterial activity of 9 microM LL-37 and completely blocked the antibacterial activity of 9 microM PF-18. However, 10 mg of the surfactant preparation per ml had only minor inhibitory effects on LL-37 and PF-18 at 90 microM. Addition of up to 900 microM PF-18 did not affect the surface properties of the surfactant preparation. These data suggest that surfactant preparations containing antimicrobial peptides could be useful for the local treatment of pulmonary infections.

Immunogenicity of a 26-valent group A streptococcal vaccine.

A multivalent vaccine containing amino-terminal M protein fragments from 26 different serotypes of group A streptococci was constructed by recombinant techniques. The vaccine consisted of four different recombinant proteins that were formulated with alum to contain 400 microg of protein per dose. Rabbits were immunized via the intramuscular route at 0, 4, and 16 weeks. Immune sera were assayed for the presence of type-specific antibodies against the individual recombinant M peptides by enzyme-linked immunosorbent assay and for opsonic antibodies by in vitro opsonization tests and indirect bactericidal tests. The 26-valent vaccine was highly immunogenic and elicited fourfold or greater increases in antibody levels against 25 of the 26 serotypes represented in the vaccine. The immune sera were broadly opsonic and were bactericidal against the majority of the 26 different serotypes. Importantly, none of the immune sera cross-reacted with human tissues. Our results indicate that type-specific, protective M protein epitopes can be incorporated into complex, multivalent vaccines designed to elicit broadly protective opsonic antibodies in the absence of tissue-cross-reactive antibodies.

Serotyping group B streptococci in a small community hospital: an analysis of distribution and site of isolation.

To determine the prevalence and site of isolation of different serotypes of group B streptococcus (GBS) colonization or infection at a small community hospital. GBS isolates were obtained from a small community hospital and were then serotyped as la, Ib, II, III, IV, V or nontypeable. Hospital records were reviewed for patient sex, age and pregnancy status as well as the site of GBS isolation. GBS serotypes Ia, III and V were most common and accounted for over 60% of the total number of isolates. Serotype Ia was most prevalent in reproductive-age females, while serotypes V and III were most prevalent in non-reproductive-age females and males, respectively. Serotype la was most frequent in both pregnant and nonpregnant females. Serotype IV was more common in this study population than in those from other locations. The GBS serotype distribution in this small community did not differ significantly from distributions described in larger North American centers. A GBS vaccine designed against multiple serotypes would be protective for most of this population.

Experimental glomerulonephritis following successive inoculation of five different serotypes of group B coxsackieviruses in mice.

The purpose of the present investigation is to study renal injury by monthly viral inoculation into mice, using several different types of strains of enterovirus. A group of mice were inoculated intravenously with five different serotypes of group B coxsackieviruses (CB1 to CB5), once a month from 1 to 5 months of age and sacrificed monthly from 6 to 12 months of age. Mesangial proliferation and PAS-positive mesangial deposits in light microscopy and electron-dense deposits in electron microscopy were observed at maximum from 6 to 7 months of age. The CB viral RNA detected by in situ hybridization were observed in the mesangial lesion. By immunofluorescence findings, positive findings for IgG and IgA were observed. These results demonstrated that intermittent intravenous inoculation with different serotypes CB in mice provoked pathological changes closely resembling those in human proliferative glomerulonephritis. Moreover, the detection of CB viral RNA in glomerular lesions suggested that renal injury was induced by immune complexes correlated with CB viral replication in renal tissues.

Characterization of murine monoclonal antibodies against serogroup B salmonellae and application as serotyping reagents

Six murine hybridoma monoclonal antibodies reactive with lipopolysaccharide antigens of Salmonella typhimurium were obtained from a fusion of immune spleen cells from mice immunized with S. typhimurium and NS1 myeloma cells. Four antibodies appeared to be specific for serogroup B salmonellae, while the remaining two antibodies were found to be cross-reactive with Salmonella paratyphi A. The exquisite specificities of the Salmonella serogroup B monoclonal antibodies were demonstrated by their unique reactivities with different serotypes of group B salmonellae but with neither other O serogroups of salmonellae nor a wide spectrum of standard strains of other bacterial species. Serotyping of salmonella strains by the slide agglutination method with two of the serogroup B-specific monoclonal antibodies demonstrated their usefulness as serotyping reagents for the identification of serogroup B salmonellae in a routine diagnostic bacteriology laboratory.

Adherence of group B streptococci to adult and neonatal epithelial cells mediated by lipoteichoic acid.

We have investigated the role of lipoteichoic acid in mediating the adherence of different serotypes of group B streptococci to human adult and neonatal epithelial cells. Pretreatment of neonatal buccal and vaginal epithelial cells with lipoteichoic acid, but not with deacylated lipoteichoic acid, induced a marked inhibition in the adherence of all strains tested. Pretreatment of bacteria with substances known to bind lipoteichoic acid, such as monoclonal and polyclonal antipolyglycerophosphate antibodies and albumin, also resulted in adherence inhibition. Group B streptococci adhered in 6- to 10-fold-higher numbers to buccal epithelial cells from neonates older than 3 days than to those from neonates less than 1 day old. This increase in receptiveness for group B streptococci was paralleled by an increased ability of epithelial cells from older neonates to bind group B streptococcal lipoteichoic acid. These data suggest a role for the lipid portion of lipoteichoic acid in the adherence of different serotypes of group B streptococci to vaginal and neonatal epithelial cells.

PROTECTIVE EFFECT OF NATURALLY ACQUIRED HOMOTYPIC AND HETEROTYPIC ROTAVIRUS ANTIBODIES

To assess serotype specificity of immune resistance to rotavirus gastroenteritis, the relation between pre-existing neutralising antibodies to homotypic and heterotypic rotaviruses and protection against infection or clinical illness was investigated. The subjects were 44 orphans exposed once or twice to consecutive outbreaks of gastroenteritis due to type 3 rotavirus in an orphanage in Sapporo. Sera were collected throughout these outbreaks and the serum levels of neutralising antibodies against four different serotypes of group A human rotavirus were measured before and after the outbreaks. Protection against rotavirus gastroenteritis seemed to be serotype specific and to be related to levels of antibody against homotypic virus. A neutralising antibody level of 1/128 or greater seemed to be protective. The protective effect was of short duration, which was probably the explanation for recurrent attacks of gastroenteritis due to a rotavirus of the sarne serotype. Seroconversions or concomitant antibody responses to type 1 or 4 rotavirus in most children with type 3 rotavirus infection suggested that immunity to heterotypic virus can be induced by a rotavirus vaccine.

Opsonic antibodies evoked by hybrid peptide copies of types 5 and 24 streptococcal M proteins synthesized in tandem.

The protective immunogenicity of a hybrid peptide containing tandem copies of types 5 and 24 epitopes was investigated. Carboxy-terminal peptides of the cyanogen bromide-derived fragment 7 (CB7) of type 24 M protein were chemically synthesized, and then extended to include the first 20 residues of the amino-terminus of type 5 M protein. When emulsified in CFA and injected into rabbits without conjugation to a carrier, each of the synthetic hybrid peptides, designated S-M5(1-20)-S-CB7(23-35)C and S-M5(1-20)-S-CB(19-34), evoked opsonic antibodies against both types 5 and 24 streptococci without raising heart tissue-crossreactive immunity. These results suggest that tandem hybrid peptides may provide a new approach to the development of multivalent vaccines, not only to different serotypes of group A streptococci but perhaps also to a variety of other infectious agents.

Epitopes of streptococcal M proteins shared with cardiac myosin.

We present evidence that M proteins from three different serotypes of group A streptococci share epitopes with cardiac myosin. Rabbit antisera evoked by a purified fragment of type 5 M protein crossreacted with myosin, but not alpha-tropomyosin, actin, or myosin light chains. In enzyme-linked immunosorbent assays, the myosin-crossreactive antibodies were totally inhibited by type 5 M protein and partially inhibited by types 6 and 19 M proteins. The affinity-purified myosin antibodies opsonized type 5 streptococci, indicating that they were directed against protective M protein epitopes on the surface of the organisms. Immunoblot analyses demonstrated the binding of the crossreactive antibodies to myosin heavy chains. Sera from patients with acute rheumatic fever showed significantly stronger reactions with myosin than did sera from their siblings, hospitalized controls, or patients with poststreptococcal glomerulonephritis.

Unique and common protective epitopes among different serotypes of group A streptococcal M proteins defined with hybridoma antibodies.

A set of four monoclonal antibodies was produced against a highly purified pepsin extract of type 5 streptococcal M protein. Three of the four antibodies cross-reacted with purified M proteins from heterologous serotypes and opsonized the respective heterologous organisms. Our studies suggest that monoclonal antibodies may be useful in identifying subpeptides of various M proteins containing common, protective epitopes that are capable of evoking antibodies that would protect against several different potentially "rheumatogenic" serotypes.

Induction of human gamma interferon by structurally defined polypeptide fragments of group A streptococcal M protein.

The presence of interferon (IFN) has been demonstrated previously (i) in fluids obtained from the middle ears of children with Streptococcus pneumoniae infections, (ii) from the serum of mice injected intraperitoneally with either S. pneumoniae or Streptococcus pyogenes, and (iii) from human lymphoid cell cultures treated with a variety of bacteria. In this study, we showed that highly purified peptic extracts of three different serotypes of group A streptococcal M protein (pep M5, pep M6, and pep M24) stimulated human peripheral leukocytes to produce IFN. IFN production was apparent by 10 h and peaked 24 h after exposure. Dose-response experiments indicated that IFN could be detected in cultures treated with concentrations of M protein as low as 6 micrograms/ml, whereas maximum IFN production occurred at a concentration of 200 micrograms/ml. The IFN had antigenic and physicochemical characteristics of IFN-gamma. Preliminary leukocyte fractionation studies revealed that the IFN-producing cell was a nonadherent lymphocyte with receptors for sheep erythrocytes (T cell). Rabbit antisera specific for these structurally defined polypeptide fragments of streptococcal M protein (pep M5, pep M6, and pep M24) blocked IFN induction by each of the polypeptides. The data suggest that the different serotypes of streptococcal M protein may induce IFN by a common structural determinant shared by each of the polypeptide fragments tested.

Meningococcal disease in Scandinavia.

Scandinavia (Denmark, Finland, Iceland, Norway, and Sweden) comprises with mutual borders and 22.3 million inhabitants an area where the socioeconomic and cultural conditions are similar. Epidemic diseases, such as meningococcal infection, might therefore be expected to be uniformly distributed. An epidemiological study in the 10-year period 1970-9 shows, however, remarkable differences in the incidence, age, and serogroup and type distribution, as well as in the general dynamics of the disease. Three epidemics, two caused by different serotypes of group B (Norway and Iceland) and one by group A (Finland) occurred within the observation period. The annual overall incidence was generally around 3/100 000 but increased from fivefold (Finland) to eightfold (northern Norway) during epidemics. The epidemic strains caused infection in over 3000 patients and the loss of at least 250 lives. The overall case fatality rate was 8.6% (range 4.1-13.7%). Men were more susceptible and had a worse prognosis than women of the same age group. The group A epidemic in Finland was influenced by a large vaccination campaign, but this possibility was not feasible in the two other epidemics.