Identification of virulence factors and antibiotic resistance in Salmonella enterica subsp. enterica serovar Javiana (FARPER-220) isolated from broiler chickens.

Genome sequencing of highly virulent Salmonella enterica subsp. enterica serovar Javiana strain FARPER-220 (ST-1674) isolated from broiler chickens in Peru revealed multiple virulence factors, antibiotic resistance genes, and invasion-related subcategories. The results provide insights into the potential importance of this strain in causing infections in various animals.

Detection and Genomic Characterization of an Avian Influenza Virus Subtype H5N1 (Clade 2.3.4.4b) Strain Isolated from a Pelican in Peru.

Surveillance helps us identify and monitor strains with zoonotic potential. A tracheal swab from a pelican on a Peruvian beach was H5N1 positive (clade 2.3.4.4b) using Oxford Nanopore's MinION platform. The near-complete genome sequence of strain VFAR-140 will aid us in understanding avian influenza epidemiology and spread.

Draft Genome Sequence of an Isolate of Genotype VII Newcastle Disease Virus Isolated from an Outbreak in Fighting Cock in Peru.

This study presents a draft genome sequence of a Newcastle disease virus (NDV) strain (VFAR-136) isolated from a fighting cock (Gallus gallus) in the south of Peru. Strain VFAR-136 is a new report of NDV genotype VII circulating in Peru.

Squalene in oil-based adjuvant improves the immunogenicity of SARS-CoV-2 RBD and confirms safety in animal models.

COVID-19 pandemic has accelerated the development of vaccines against its etiologic agent, SARS-CoV-2. However, the emergence of new variants of the virus lead to the generation of new alternatives to improve the current sub-unit vaccines in development. In the present report, the immunogenicity of the Spike RBD of SARS-CoV-2 formulated with an oil-in-water emulsion and a water-in-oil emulsion with squalene was evaluated in mice and hamsters. The RBD protein was expressed in insect cells and purified by chromatography until >95% purity. The protein was shown to have the appropriate folding as determined by ELISA and flow cytometry binding assays to its receptor, as well as by its detection by hamster immune anti-S1 sera under non-reducing conditions. In immunization assays, although the cellular immune response elicited by both adjuvants were similar, the formulation based in water-in-oil emulsion and squalene generated an earlier humoral response as determined by ELISA. Similarly, this formulation was able to stimulate neutralizing antibodies in hamsters. The vaccine candidate was shown to be safe, as demonstrated by the histopathological analysis in lungs, liver and kidney. These results have shown the potential of this formulation vaccine to be evaluated in a challenge against SARS-CoV-2 and determine its ability to confer protection.

Intranasal vaccination of hamsters with a Newcastle disease virus vector expressing the S1 subunit protects animals against SARS-CoV-2 disease.

The coronavirus disease-19 (COVID-19) pandemic has already claimed millions of lives and remains one of the major catastrophes in the recorded history. While mitigation and control strategies provide short term solutions, vaccines play critical roles in long term control of the disease. Recent emergence of potentially vaccine-resistant and novel variants necessitated testing and deployment of novel technologies that are safe, effective, stable, easy to administer, and inexpensive to produce. Here we developed three recombinant Newcastle disease virus (rNDV) vectored vaccines and assessed their immunogenicity, safety, and protective efficacy against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in mice and hamsters. Intranasal administration of rNDV-based vaccine candidates elicited high levels of neutralizing antibodies. Importantly, the nasally administrated vaccine prevented lung damage, and significantly reduced viral load in the respiratory tract of vaccinated animal which was compounded by profound humoral immune responses. Taken together, the presented NDV-based vaccine candidates fully protected animals against SARS-CoV-2 challenge and warrants evaluation in a Phase I human clinical trial as a promising tool in the fight against COVID-19.

Development of a lateral flow test for the rapid detection of Avibacterium paragallinarum in chickens suspected of having infectious coryza.

BACKGROUND: Infectious coryza (IC) is an acute respiratory disease of growing chickens and layers caused by Avibacterium paragallinarum. The development of tools that allow rapid pathogen detection is necessary in order to avoid disease dissemination and economic losses in poultry. An Av. paragallinarum-specific Ma-4 epitope of the TonB-dependent transporter (TBDT) was selected using bioinformatic tools in order to immunize a BalbC mouse and to produce monoclonal antibodies to be used in a lateral flow test (LFT) developed for Av. paragallinarum detection in chicken nasal mucus samples. RESULTS: The 1G7G8 monoclonal antibody was able to detect TBDT in Av. paragallinarum cultures (serogroups: A, B and C) by Western blot and indirect ELISA assay. Consequently, we developed a self-pairing prototype LFT. The limit of detection of the prototype LFT using Av. paragallinarum cultures was 1 × 104 colony-forming units (CFU)/mL. Thirty-five nasal mucus samples from chickens suspected of having infectious coryza were evaluated for the LFT detection capacity and compared with bacterial isolation (B.I) and polymerase chain reaction (PCR). Comparative indicators such as sensitivity (Se), specificity (Sp), positive predictive value (PPV), negative predictive values (NPV) and the kappa index (K) were obtained. The values were 100.0% Se, 50% Sp, 65.4% PPV, 100% NPV, and 0.49 K and 83.9% Se, 100% Sp, 100% PPV, 44.4% NPV, and 0.54 K for the comparison of the LFT with B.I and PCR, respectively. Additionally, the LFT allowed the detection of Av. paragallinarum from coinfection cases of Av. paragallinarum with Gallibacterium anatis. CONCLUSIONS: The results indicate that the self-pairing prototype LFT is suitable for the detection of TBDT in Av. paragallinarum cultures as well as in field samples such as nasal mucus from Av. paragallinarum-infected chickens. Therefore, this prototype LFT could be considered a rapid and promising tool to be used in farm conditions for Av. paragallinarum diagnosis.