Quantitative method for measuring the proportion of bacterial cells expressing phase 1 or 2 of flagellin of Salmonella enterica serovar Typhimurium.

Salmonella enterica subsp. enterica is a major pathogen that causes zoonotic foodborne diseases worldwide. Some Salmonella serovars possess two antigenic phases for flagellin: phase 1 and 2.

Outer membrane protein BamA-based ELISA differentiates Salmonella-vaccinated chickens from naturally infected chickens.

Salmonella often causes subclinical infection in chickens, but antibody tests can find infected individuals and control the spread of infection. In this study, the S. Typhimurium-specific outer membrane, β-barrel assembly machinery protein A (BamA), was overexpressed in Escherichia coli and purified as a coating antigen to develop a BamA-based enzyme-linked immuno sorbent assay for detecting Salmonella infection.

Differentiation of Salmonella vaccinated and infected animals by serological detection of antibody to T3SS effector SsaK in an indirect ELISA.

The differentiation of animals that are vaccinated and those that are naturally infected with Salmonella is difficult by conventional serological tests. We have shown here an indirect Enzyme-linked immunosorbent assay for detection of Salmonella infection based on the presence of a Type III secretory effector SsaK in the sera.

Rational Design of Live-Attenuated Vaccines against Genome-Reduced Pathogens.

To develop safe and highly effective live vaccines, rational vaccine design is necessary. Here, we sought a simple approach to rationally develop a safe attenuated vaccine against the genome-reduced pathogen Erysipelothrix rhusiopathiae. We examined the mRNA expression of all conserved amino acid biosynthetic genes remaining in the genome after the reductive evolution of .

Two Akabane virus glycoprotein Gc domains induce neutralizing antibodies in mice.

Akabane virus (AKAV), belonging to the genus Orthobunyavirus and family Peribunyaviridae, causes reproductive and congenital abnormalities in ruminants. Its envelope glycoprotein Gc is a neutralizing antigen, on which at least five distinct antigenic regions have been identified. We attempted to identify the domains using truncated recombinant AKAV Gc proteins expressed in Escherichia coli and monoclonal antibodies (mAbs) with AKAV-neutralizing activity.

Genetic analysis of an Erysipelothrix rhusiopathiae swine isolate determined to be serovar 2 by a gel double diffusion test but serovar 1a/2 by a serotyping PCR assay.

We previously developed a multiplex PCR assay for the differentiation of serovar 1a, 1b, 2 and 5 strains of Erysipelothrix rhusiopathiae. In this study, we analyzed the serovar-defining chromosomal region of a serovar 2 swine isolate, which was PCR-positive for both serovars 1a and 2 by the multiplex PCR assay. Genetic analysis of the chromosomal region revealed that, as in serovar 1a strains, the ERH_1440 gene, which is usually truncated or missing in serovar 2 strains, was intact in this strain.

The protective capacity of anti-O4 antigen antibodies against Salmonella infection is influenced by the presence or absence of the O5 antigen.

Anti-O-antigen antibodies, such as anti-O4 antigen IgG, induce protective immunity against Salmonella enterica serovar Typhimurium (S. Typhimurium) infection. S.

Development of a Multiplex PCR-Based Assay for Rapid Serotyping of Species.

The Gram-positive bacterium is a zoonotic pathogen that causes erysipelas in a wide range of mammalian and avian species. Historically, has been differentiated from other species by serotyping. Among 28 serovars of species, specific serovars, namely, 1a, 1b, and 2 of , are associated mainly with the disease in pigs, poultry, and humans; however, other serovar strains are often simultaneously isolated from diseased and healthy animals, indicating the importance of isolate serotyping for epidemiology.

Successful enrichment of low-abundant comammox Nitrospira from nitrifying granules under ammonia-limited conditions.

In artificial engineered systems, nitrification is a key reaction that accounts for the removal of biological nitrogen. Recently, a single microbe capable of oxidizing ammonia to nitrate, known as a complete ammonia oxidizer (comammox), has been discovered. Although the abundance and diversity of comammox Nitrospira in engineered systems have been identified through molecular-based approaches, the enrichment and isolation of comammox Nitrospira remains a challenge.

A putative transcription regulator involved in the virulence attenuation of an acriflavine-resistant vaccine strain of Erysipelothrix rhusiopathiae, the causative agent of swine erysipelas.

Acriflavine, an acridine dye that causes frameshift mutations, has been used to attenuate various veterinary pathogens for the development of live vaccines. Erysipelothrix rhusiopathiae Koganei 65-0.15 strain (Koganei) (serovar 1a) is the acriflavine-resistant live vaccine currently used in Japan for the control of swine erysipelas.

Application of stabilized hypobromite for controlling membrane fouling and N-nitrosodimethylamine formation.

Chloramination is a conventional and successful pre-disinfection approach to control biological fouling for reverse osmosis (RO) treatment in water reuse. This study aimed to evaluate the possibility of using a new disinfectant-stabilized hypobromite-in controlling membrane fouling and the formation of a particular carcinogenic disinfection byproduct (DBP)-N-nitrosodimethylamine (NDMA). Our accelerated chemical exposure tests showed that the new disinfectant reduced the permeability of a polyamide RO membrane permeability from 6.

Genome-Wide Identification of Virulence Genes in : Use of a Mutant Deficient in a Homolog as a Safe Oral Vaccine against Swine Erysipelas.

Swine erysipelas is caused by the Gram-positive pathogen The swine erysipelas live vaccine in Japan, the Koganei 65-0.15 strain (Koganei), has been reported to cause arthritis and endocarditis. To develop a vaccine with increased safety, we used a virulent Fujisawa strain to construct transposon mutants for a total of 651 genes, which covered 38% of the coding sequence of the genome.

Wild boars: A potential source of Erysipelothrix rhusiopathiae infection in Japan.

The potential role of wild boars as a source of erysipelas infection was investigated. An ELISA test of wild boar serum samples from 41 prefectures in Japan revealed that proportions of the Erysipelothrix rhusiopathiae-positive samples were very high in all the prefectures, and the mean positive rate was 95.6% (1312/1372).

Disassociation of Spa type and serovar of an Erysipelothrix rhusiopathiae serovar 6 strain isolated from a diseased pig.

The surface protective antigen (Spa) protein of Erysipelothrix rhusiopathiae is an important component in protecting pigs against swine erysipelas. The Spa protein has been antigenically divided into 3 types: SpaA, SpaB, and SpaC. Swine erysipelas vaccines are formulated with strains of serovar 1 and/or 2, both of which are SpaA-possessing serovars.

Draft Genome Sequences of Lawsonia intracellularis Swine Strains Causing Proliferative Enteropathy in Japan.

The draft genome sequences of three strains of Lawsonia intracellularis, an obligate intracellular animal pathogen responsible for causing proliferative enteropathy, obtained from swine in different prefectures in Japan revealed the absence of a genomic island previously reported to be linked to host adaptation and to high genomic diversity, despite geographical proximity.

Identification of serovar 1a, 1b, 2, and 5 strains of Erysipelothrix rhusiopathiae by a conventional gel-based PCR.

Among the four species of the genus Erysipelothrix, Erysipelothrix rhusiopathiae is the main species that causes disease in swine and poultry and has also been isolated from human patients. Recently, E. rhusiopathiae infections in domesticated animals have increased in many countries and are also the cause of emerging wildlife disease in arctic and boreal ecosystems.

Identification of the Chromosomal Region Essential for Serovar-Specific Antigen and Virulence of Serovar 1 and 2 Strains of Erysipelothrix rhusiopathiae.

causes swine erysipelas, an infection characterized by acute septicemia or chronic endocarditis and polyarthritis. Among 17 serovars, determined based on heat-stable peptidoglycan antigens, serovars 1 and 2 are most commonly associated with the disease; however, the molecular basis for the association between these serovars and virulence is unknown. To search for the genetic region defining serovar 1a (Fujisawa) strain antigenicity, we examined the 15-kb chromosomal region encompassing a putative pathway for polysaccharide biosynthesis, which was previously identified in the Fujisawa strain.

In vivo effect of a TLR5 SNP (C1205T) on Salmonella enterica serovar Typhimurium infection in weaned, specific pathogen-free Landrace piglets.

Toll-like receptor 5 is a pattern-recognition receptor for bacterial flagellin. We previously reported that a single nucleotide polymorphism (SNP) of swine TLR5, C1205T, impairs recognition of Salmonella typhimurium (ST) flagellin and ethanol-killed Salmonella Choleraesuis (SC). In the present study, weaned, specific pathogen-free (SPF) Landrace piglets with CC, CT or TT genotypes were orally infected with ST (L-3569 strain) to determine the effect of this specific SNP on ST infection in vivo.

High-rate nitrification of electronic industry wastewater by using nitrifying granules.

Nitrifying granules have a high sedimentation property and an ability to maintain a large amount of nitrifying bacteria in a reaction tank. Our group has examined the formation process of nitrifying granules and achieved high-rate nitrification for an inorganic synthetic wastewater using these granules. In this research, a pilot-scale test plant with an 850-liter reaction tank was assembled in a semiconductor manufacturing factory in order to conduct a continuous water conduction test using real electronics industry wastewater.

Multiplex PCR assay for the simultaneous detection and differentiation of clonal lineages of Erysipelothrix rhusiopathiae serovar 1a strains currently circulating in Japan.

The species Erysipelothrixrhusiopathiae displays genetic heterogeneity; however, E. rhusiopathiae serovar 1a strains currently circulating in Japan exhibit remarkably low levels of genetic diversity and group into clonal sublineages of Lineage IVb (IVb-1 and IVb-2). In the present study, based on whole genome sequencing data, we designed primers for a multiplex PCR assay to simultaneously detect and differentiate the sublineages of E.

Determination of O:4 antigen-antibody affinity level in O:5 antigen positive and negative variants of Salmonella enterica serovar Typhimurium.

Salmonella enterica serovar Typhimurium (S. Typhimurium) has two serological variants: one that expresses the O:5 antigen (1,4,5,12:i:1,2) and one that lacks O:5 antigen (1,4,12:i:1,2). For serotyping, S.

Clonal Lineages of Erysipelothrix rhusiopathiae Responsible for Acute Swine Erysipelas in Japan Identified by Using Genome-Wide Single-Nucleotide Polymorphism Analysis.

causes swine erysipelas, an important infectious disease in the swine industry. In Japan, the incidence of acute swine erysipelas due to serovar 1a has recently increased markedly. To study the genetic relatedness of the strains from the recent cases, we analyzed 34 serovar 1a swine isolates collected between 1990 and 2011 and further investigated the possible association of the live Koganei 65-0.

Single nucleotide polymorphism genotyping of Erysipelothrix rhusiopathiae isolates from pigs affected with chronic erysipelas in Japan.

Over the past decades, Erysipelothrix rhusiopathiae strains displaying similar phenotypic and genetic profiles of the attenuated, acriflavine-resistant E. rhusiopathiae Koganei 65-0.15 strain (serovar 1a) have been frequently isolated from pigs affected with chronic erysipelas in Japan.

Specific Monoclonal Antibody Overcomes the Salmonella enterica Serovar Typhimurium's Adaptive Mechanisms of Intramacrophage Survival and Replication.

Salmonella-specific antibodies play an important role in host immunity; however, the mechanisms of Salmonella clearance by pathogen-specific antibodies remain to be completely elucidated since previous studies on antibody-mediated protection have yielded inconsistent results. These inconsistencies are at least partially attributable to the use of polyclonal antibodies against Salmonella antigens. Here, we developed a new monoclonal antibody (mAb)-449 and identified its related immunogen that protected BALB/c mice from infection with Salmonella enterica serovar Typhimurium.