Unity among the diverse RNA-guided CRISPR-Cas interference mechanisms.

CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR-associated) systems are adaptive immune systems that protect bacteria and archaea from invading mobile genetic elements (MGEs). The Cas protein-CRISPR RNA (crRNA) complex uses complementarity of the crRNA "guide" region to specifically recognize the invader genome. CRISPR effectors that perform targeted destruction of the foreign genome have emerged independently as multi-subunit protein complexes (Class 1 systems) and as single multi-domain proteins (Class 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.

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.

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.

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.

Variation in antigen-antibody affinity among serotypes of Salmonella O4 serogroup, determined using specific antisera.

Serotyping is widely used for typing Salmonella during surveillance, and depends on determining the lipopolysaccharide (LPS) O-antigen and the flagellar protein (H-antigens) components. As the O-antigen is highly variable, and structurally unique to each serotype, we investigated the binding affinities of LPS from Salmonella serotypes of O4 serogroup with specific anti-antigen serum via immunoblot and enzyme-linked immunosorbent assays. Since the serotypes from O4 serogroup also express the O-antigen factor 12, O12 antiserum was also used for the analysis.

Monoclonal antibody-based competitive enzyme-linked immunosorbent assay to detect antibodies to O:4 Salmonella in the sera of livestock and poultry.

Serotyping is an important element for surveillance of Salmonella. In this study, an anti-O:4 Salmonella monoclonal antibody-based competitive enzyme-linked immunosorbent assay that could identify Salmonella infection in cow, pig, horse, and chicken was developed. This detection system can therefore be useful for a wide range of animals and for humans.

A rapid differentiation method for enteroinvasive Escherichia coli.

Enteroinvasive Escherichia coli (EIEC) comprise 21 major serotypes defined by the presence of O and H antigens, and diagnosis depends on determining its invasive potential. Using HEp-2 cells infected with an EIEC strain, we developed a simple growth-dependent assay that differentiated EIEC strain from non-invasive strains 6 h after infection.