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Different Serotypes (different + serotype)
Selected AbstractsDiversity of staphylocoagulase and identification of novel variants of staphylocoagulase gene in Staphylococcus aureusMICROBIOLOGY AND IMMUNOLOGY, Issue 7 2008Marie Kinoshita ABSTRACT Staphylocoagulase (SC) is a major phenotypic determinant of Staphylococcus aureus. Serotype of SC (coagulase type) is used as an epidemiological marker and 10 types (I,X) have been discriminated so far. To clarify genetic diversity of SC within a single and among different serotype(s), we determined approximately 1500 bp-nucleotide sequences of SC gene encoding D1, D2, and central regions (N-terminal half and central regions of SC; SCNC) for a total of 33 S. aureus strains comprising two to three strains from individual coagulase types (I,VIII, X) and 10 strains which were not determined as previously known SC serotypes (ND-strains). Amino acid sequence identities of SCNC among strains with a single coagulase type of II, III, IV, V, VI and X were extremely high (more than 99%), whereas lower identity (56,87%) was observed among different types. In contrast, within a single coagulase type of I, VII, or VIII, sequence divergence was found (lowest identity; 82%). SCNC sequences from the ND-strains were discriminated into two genetic groups with an identity of 71% to each other (tentatively assigned to genotypes [XI] and [XII]), and exhibited less than 86% sequence identities to those of most known coagulase types. All the types [XI] and [XII] strains were methicillin susceptible and belonged to different sequence types from those of coagulase types I,X strains reported so far by multilocus sequence typing. These findings indicated genetic heterogeneity of SC in coagulase types I, VII, and VIII strains, and the presence of two novel SC genotypes related to antigenicity of SC serotypes. [source] Construction of a multivalent vaccine strain of Shigella flexneri and evaluation of serotype-specific immunityFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2006Amy V. Jennison Abstract Shigella flexneri causes more fatalities by shigellosis than any other Shigella species. There are 13 different serotypes of S. flexneri and their distribution varies between endemic geographical regions. The immune response against S. flexneri is serotype-specific, so current immunization strategies have required the administration of multiple vaccine strains to provide protection against multiple serotypes. In this study, we report the construction of a multivalent S. flexneri vaccine strain, SFL1425, expressing the O-antigen structure specific for serotypes 2a and 5a. This combination of type antigens has not previously been reported for S. flexneri. The multivalent vaccine strain, SFL1425 was able to induce a specific immune response against both serotypes 2a and 5a in a mouse pulmonary model. [source] Salmonella enteritidis temperature-sensitive mutants protect mice against challenge with virulent Salmonella strains of different serotypesFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 2 2000M.Magdalena Gherardi Abstract The protection conferred by temperature-sensitive mutants of Salmonella enteritidis against different wild-type Salmonella serotypes was investigated. Oral immunization with the single temperature-sensitive mutant E/1/3 or with a temperature-sensitive thymine-requiring double mutant (E/1/3T) conferred: (i) significant protection against the homologous wild-type Salmonella strains; (ii) significant cross-protection toward high challenge doses of S. typhimurium. Significant antibody levels against homologous lipopolysaccharide and against homologous and heterologous protein antigens were detected in sera from immunized mice. Moreover, a wide range of protein antigens from different Salmonella O serotypes were recognized by sera from immunized animals. Besides, primed lymphocytes from E/1/3 immunized mice recognized Salmonella antigens from different serotypes. Taken together, these results indicate that temperature-sensitive mutants of S. enteritidis are good candidates for the construction of live vaccines against Salmonella. [source] Repetitive elements sequence (REP/ERIC)-PCR based genotyping of clinical and environmental strains of Yersinia enterocolitica biotype 1A reveal existence of limited number of clonal groupsFEMS MICROBIOLOGY LETTERS, Issue 2 2004Pooja Sachdeva Abstract REP- and ERIC-PCR genotyping were used to assess genetic heterogeneity among 81 strains of Yersinia enterocolitica biotype 1A isolated from India, Germany, France and the USA. Although both gave comparable results, ERIC fingerprints discriminated the strains better. The rep- (REP and ERIC) PCR genotyping showed that strains having different serotypes produced identical rep-profiles indicating their limited genetic diversity. The concatenated dendrogram of REP- and ERIC-PCR fingerprints clustered the biotype 1A strains into two major groups. In each group, majority of the Indian, European and American strains exhibited similarities ranging from 85% to >95%. Similarity of rep-PCR fingerprints amongst strains isolated from widely separated geographical regions revealed existence of a limited number of clonal groups of Y. enterocolitica biotype 1A. The present study failed to reveal unequivocal relationships between rep-PCR genotypes and the source of isolation. However, the clinical serotype O:6,30-6,31 strains formed a tight cluster and the aquatic O:6,30-6,31 strains formed a yet another tight cluster. [source] Prevalence of Salmonella enterica serovars and genovars from chicken carcasses in slaughterhouses in SpainJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2007R. Capita Abstract Aims: To determine the prevalence of Salmonella enterica serovars in chicken carcasses in slaughterhouses in Spain and to examine genotypic relations among these serovars. Methods and Results: A total of 336 chicken carcasses were collected from six slaughterhouses in Northwestern Spain. Salmonellae were isolated (ISO-6579-1993), serotyped, phage-typed, ribotyped and antibiotyped against 20 antibiotics. Salmonella strains were detected in 60 (17·9%) carcasses. Isolates belonged to nine different serotypes, with Salm. Enteritidis being the most common. Three strains (5%) were resistant to one antibiotic and 24 (40%) were multi-resistant (to more than one antibiotic). The most frequently encountered resistances were to sulphamides, fluoroquinolones and tetracycline. Ribotyping was able to differentiate isolates of the same serotype and phage type. Conclusions: The Salmonella serotypes and phage types detected are among those most frequently associated with human diseases in Spain. The large percentage of antimicrobial resistant strains is a matter for concern. A high genetic relationship between strains from different slaughterhouses was found. Significance and Impact of the Study: This study provides detailed information about Salmonella isolates from poultry in Spain. It emphasizes the importance of controlling this pathogen in poultry products, and suggests the need for more prudent use of antibiotics. [source] Predictive models of the combined effects of curvaticin 13, NaCl and pH on the behaviour of Listeria monocytogenes ATCC 15313 in brothJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2000A. Bouttefroy Thirty-three strains of Listeria monocytogenes belonging to different serotypes were tested for their sensitivity to curvaticin 13, an antilisterial bacteriocin produced by Lactobacillus curvatus SB13, using the well diffusion method in Institut Pasteur agar plates at 37 °C. No relationship between serotype and sensitivity was observed. The sensitivity of this species was strain-dependent and a large variation in tolerance to curvaticin 13 was observed. The combined effects of curvaticin 13 (0,160 AU ml,1), NaCl (0,6% w/v), pH values (5·0,8·2) and incubation time (0,24 h) were investigated on L. monocytogenes ATCC 15313 in trypcase soy,yeast extract broth at 22 °C. For this study, two Doehlert matrices were used in order to investigate the main effects of these factors and their different interactions. The results were analysed using the Response Surface Methodology. Curvaticin 13 had a major inhibitory effect and the response was NaCl concentration-, time- and pH-dependent. This inhibitory activity was the same at pH values between 6·6 and 8·2. Curvaticin 13 was bactericidic at acidic pH values, but the surviving cells resumed growth. For a short incubation time (12 h), the effectiveness of curvaticin 13 was maximal in the absence of NaCl. For longer incubation times (12,48 h), with high NaCl (6%) and curvaticin 13 concentrations (160 AU ml,1), the inhibition of L. monocytogenes was greater than that observed with NaCl or curvaticin 13 alone. [source] Efficacy of injection vaccines against Flavobacterium psychrophilum in rainbow trout, Oncorhynchus mykiss (Walbaum)JOURNAL OF FISH DISEASES, Issue 1 2006J Madetoja Abstract Efficacy of mineral oil-based experimental injection vaccines against Flavobacterium psychrophilum were tested in rainbow trout, Oncorhynchus mykiss (Walbaum), under laboratory and field conditions. The vaccines consisted of formalin- or heat-inactivated whole bacterium cell preparations of two different serotypes (Fd and Th) or a combination of serologically different F. psychrophilum (Fd and/or Th and/or FpT;Th). Specific antibody responses against the bacterium in plasma and skin mucus were evaluated post-vaccination with enzyme-linked immunosorbent assay. Efficacy of the vaccinations was determined by challenge trials to F. psychrophilum with the vaccinated rainbow trout. Significantly higher antibody levels in plasma were detected in vaccinated fish compared with mock-vaccinated fish. Injection vaccination did not trigger specific antibody production in the skin mucus. Significantly higher survival of i.p. vaccinated fish compared with non-vaccinated fish was observed during the challenge. The results suggest that mineral oil-based injectable vaccines containing formalin- or heat-inactivated virulent cells of F. psychrophilum effectively triggered specific antibody production and protected the fish against bacterial cold water disease. [source] Selective human enterovirus and rhinovirus inhibitors: An overview of capsid-binding and protease-inhibiting moleculesMEDICINAL RESEARCH REVIEWS, Issue 4 2004Shin-Ru Shih Abstract The absence of effective vaccines for most viral infections highlights an urgent necessity for the design and development of effective antiviral drugs. Due to the advancement in virology since the late 1980s, several key events in the viral life cycle have been well delineated and a number of molecular targets have been validated, culminating in the emergence of many new antiviral drugs in recent years. Inhibitors against enteroviruses and rhinoviruses, responsible for about half of the human common colds, are currently under active investigation. Agents targeted at either viral protein 1 (VP1), a relatively conserved capsid structure mediating viral adsorption/uncoating process, or 3C protease, which is highly conserved among different serotypes and essential for viral replication, are of great potential to become antipicornavirus drugs. © 2004 Wiley Periodicals, Inc. Med Res Rev, 24, No. 4, 449,474, 2004 [source] Development of an oligonucleotide microarray method for Salmonella serotypingMICROBIAL BIOTECHNOLOGY, Issue 6 2008B. Tankouo-Sandjong Summary Adequate identification of Salmonella enterica serovars is a prerequisite for any epidemiological investigation. This is traditionally obtained via a combination of biochemical and serological typing. However, primary strain isolation and traditional serotyping is time-consuming and faster methods would be desirable. A microarray, based on two housekeeping and two virulence marker genes (atpD, gyrB, fliC and fljB), has been developed for the detection and identification of the two species of Salmonella (S. enterica and S. bongori), the five subspecies of S. enterica (II, IIIa, IIIb, IV, VI) and 43 S. enterica ssp. enterica serovars (covering the most prevalent ones in Austria and the UK). A comprehensive set of probes (n = 240), forming 119 probe units, was developed based on the corresponding sequences of 148 Salmonella strains, successfully validated with 57 Salmonella strains and subsequently evaluated with 35 blind samples including isolated serotypes and mixtures of different serotypes. Results demonstrated a strong discriminatory ability of the microarray among Salmonella serovars. Threshold for detection was 1 colony forming unit per 25 g of food sample following overnight (14 h) enrichment. [source] Immune responses to gene therapy vectors in the context of corneal transplantationACTA OPHTHALMOLOGICA, Issue 2009T RITTER Purpose The genetic engineering of grafts or cells prior to transplantation is an attractive approach to protect the graft from allogeneic rejection. Virus vector-based gene therapy is a promising method for successful ex-vivo gene transfer however, the induction of an immune response against gene-modified tissues raises concern. Methods Different virus families (Adenovirus, Retrovirus, Adeno-associated virus, Herpesvirus) have been studied as gene therapy vehicles for the delivery of therapeutic molecules. Moreover, different serotypes or envelope proteins have been used to modulate transduction efficiencies of target cells or to evade pre-existing immunity. Results Here we review gene therapeutic applications using viral vectors in the context of cornea transplantation. Both local and systemic expression of immunomodulatory molecules have led to the prevention of corneal graft rejection. However, different results have been obtained with regard to the induction of immune responses after local or systemic expression of the gene therapy vector. Not surprisingly over-expression of anti-inflammatory molecules not only modulated allograft rejection but also influenced the immune response against the viral vector and virally transduced cells. Conclusion Recent clinical trials indicate that the application of viral vectors in ophthalmology is promising however, the generation of immune responses against the viral vector or virally transduced cells are still a serious obstacle for a broader application of gene therapy. Supported by Deutsche Forschungsgemeinschaft (DFG Pl 150/14-1 and Ri 764/10-1) and Science Foundation of Ireland (SFI 06/RFP/BIC056 and SFI 07/IN.1/B925) [source] | |||||||||||||