Molecular Features and Antimicrobial Susceptibilities of Streptococcus equi ssp. equi Isolates from Strangles Cases in Indonesia

Strangles, caused by Streptococcus equi ssp. equi (S. equi equi), is a highly infectious and frequent disease of equines worldwide. No data are available regarding the molecular epidemiology of strangles in Indonesia. This study aimed to characterize S. equi equi isolates obtained from suspected strangles cases in Indonesia in 2018. Isolates originated from seven diseased horses on four different farms located in three provinces of Indonesia. Whole genome sequences of these isolates were determined and used for seM typing, multilocus sequence typing (MLST), and core genome MLS typing (cgMLST). Genomes were also screened for known antimicrobial resistance genes and genes encoding for the recombinant antigens used in the commercial Strangvac^® subunit vaccine. All seven S. equi equi isolates from Indonesia belonged to ST179 and carried seM allele 166. Isolates differed from each other by only 2 to 14 cgSNPs and built an exclusive sub-cluster within the Bayesian Analysis of Population Structure (BAPS) cluster 2 (BAPS-2) of the S. equi equi cgMLST scheme. All isolates revealed predicted amino acid sequence identity to seven and high similarity to one of the eight antigen fragments contained in Strangvac^®. Furthermore, all isolates were susceptible to beta-lactam antibiotics penicillin G, ampicillin, and ceftiofur. Our data suggest that the horses from this study were affected by strains of the same novel sublineage within globally distributed BAPS-2 of S. equi equi. Nevertheless, penicillin G can be used as a first-choice antibiotic against these strains and Strangvac^® may also be protective against Indonesian strains.

Kadar Protein Terlarut dalam Albumin Ikan Gabus (Channa striata dan Channa micropeltes) Asal Bogor SOLUBLE ROTEIN CONCENTRATION IN SNAKEHEAD FISH ALBUMIN BOGOR ORIGIN (CHANNA STRIATA AND CHANNA MICROPELTES)

Snakehead fish is currently used by the public as a health treatment because it has a higher content of albumin protein than others. The Research aimed was determined the protein quality and comparison levels in two species of snakehead fish, Channa striata and Channa micropeltes, derived from Bogor Regency. Protein concentration level of C. micropeltes and C. striata after drying for five minutes as much as 0.830 mg/mL and 0.803 mg/mL and these concentration were higher than dried for 10 and 15 minutes. Protein concentration levels of the two species were not significantly different. The molecular weight of albumin protein from both species were 65.56 kDa to dried for five minutes, 65.08 kDa to dried for 10 minutes, and 64.91 kDa to dried for 15 minutes. The Results concluded that there were no differences in protein levels in the fish meat and skin of the two species. Drying treatment affects the molecular weight of snakehead fish albumin protein.

Isolation and characterization of avian coronavirus from healthy Eclectus parrots (Eclectus roratus) from Indonesia

Background and Aim:

Avian coronavirus has a wide range of hosts, from chickens and turkeys to wild birds. This virus causes an economically and, possibly, environmentally, important loss in the poultry industry. Therefore, research into the avian coronavirus in various species of birds is required. The Eclectus parrot (Eclectus roratus) is an endemic bird to Indonesia and Northern Australia and often kept as pets. At present, there has been limited information about avian coronavirus infection among birds. This study aimed to determine the presence of and to characterize avian coronavirus isolated from Eclectus parrots in Indonesia.

Materials and Methods:

Cloacal swab samples were taken from 10 healthy Eclectus parrots (E. roratus). Each isolate was propagated into specific pathogen-free embryonated chicken eggs. The presence of avian coronavirus was determined using three sets of primers targeting the 3’ untranslated region (3’-UTR) of avian coronavirus (UTR41+/11−), the N gene of the infectious bronchitis virus (IBVN+/−), and the S1 gene of the IBV (XCE2+/XCE2−). The infectious bronchitis vaccine strain H120 was used as a positive control. Resulting positive bands were sequenced for the S1 gene.

Results:

None of the isolates was positive for the 3’-UTR, four isolates were positive for the N gene of infectious bronchitis, and two isolates were positive for the S1 gene of the IBV. However, only one isolate (parrot/Indonesia/BX9/16) was sequenced for the partial S1 gene with primers XCE2+/XCE2−. The partial nucleotide sequence of this isolate showed 100% homology with the IBV GI-13 lineage, specifically with a field isolate of the 4/91 variant 1 Israel and the 4/91 vaccine on the hypervariable region 3 site of the S1 gene.

Conclusion:

An IB-like avian coronavirus was isolated from healthy Eclectus parrots. Our results indicate that IBV has a wide range of hosts, which prompt the need to understand the interspecies connection of this virus better.

Production of a polyclonal antibody against acrylamide for immunochromatographic detection of acrylamide using strip tests

Objective

To produce, purify, and characterize a polyclonal antibody against acrylamide (anti-AA) for an application to immunochromatographic strip tests for AA.

Materials and Methods

Polyclonal anti-AA was prepared by injecting N-acryloxysuccinimideconjugated bovine serum albumin hapten-antigen into New Zealand white rabbits. The antibody was purified using protein A, characterized using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and conjugated with gold nanoparticles (AuNP). The conjugated antibody was then characterized using UV-Vis and FTIR spectroscopy and transmission electron microscopy (TEM). Immunochromatographic strip tests were performed using sample pads, conjugated pads, test zones, control zones, and absorbent pads. Strip tests were finally validated using standard AA solutions followed by the application of various concentrations of coffee samples.

Results

Using SDS-PAGE, the purified anti-AA antibody was resolved at 50 and 25 kDa, indicating the presence of heavy and light chains, respectively. The conjugation of anti-AA with AuNP was confirmed using wavelength shifts in UV-Vis and FTIR spectra, and TEM analyses revealed increased diameters of AuNPs after conjugation. The immunochromatographic strip test was sensitive to 1 mgml^-1 standard AA. Various concentrations of coffee samples resulted in red color differences in the test zone. High and low coffee concentrations produced thick and thin red lines, respectively.

Conclusion

Purified anti-AA can be conjugated with AuNP to produce strip tests for detecting AA in coffee samples. The present immunochromatographic strip tests quantitatively showed increasing intensities of red lines with increasing AA concentrations.

Potential risk of viral transmission from flying foxes to domestic animals and humans on the southern coast of West Java, Indonesia

Flying foxes have been considered to be involved in the transmission of serious infectious diseases to humans. Using questionnaires, we aimed to determine the direct and/or indirect contacts of flying foxes in an Indonesian nature conservation area with domestic animals and humans living in the surrounding area. We surveyed 150 residents of 10 villages in West Java. Villages were classified into 3 groups: inside and/or within 1 km from the outer border of the conservation area and 1–5 km or 5–10 km away from the reserve’s outer border. Data were collected by direct interview using a structured questionnaire consisting of the respondent characteristics (age, sex and occupation); histories of contacts between flying foxes and humans, dogs and other domestic animals; and knowledge about infectious diseases, mainly rabies, in flying foxes. We found that flying foxes from the nature conservation area often enter residential areas at night to look for food, especially during the fruit season. In these residential areas, flying foxes had direct contacts with humans and a few contacts with domestic animals, especially dogs. People who encounter flying foxes seldom used personal protective equipment, such as leather gloves, goggles and caps. The residents living around the conservation area mostly had poor knowledge about flying foxes and disease transmission. This situation shows that the population in this region is at a quite high risk for contracting infectious diseases from flying foxes.

Biological and Immunogenicity Property of IgY Anti S. mutans ComD

Objective:

This study aims to elucidate the effect of IgY anti ComD on the biological properties of Streptococcus mutans. (S. mutans) ComD is an interspecies quorum-sensing signaling receptor that plays an important role in biofilm formation by S. mutans.

Materials and Methodology:

Egg yolk IgY was produced by the immunization of chickens with a DNA vaccine containing the ComD DNA coding region. We evaluated the effect of the antibody on biofilm formation by S. mutans isolated from subjects with or without dental caries. We also assessed the immunoreactivity of the antibody against all isolates, and analyzed the protein profile of S. mutans by SDS-PAGE.

Results:

The ComD antibody was successfully induced in the hens’ eggs. It inhibited biofilm formation by all S. mutans isolates. In addition, the expression of some protein bands was affected after exposure to the antibody.

Conclusion:

IgY anti-S. mutans ComD reduces biofilm formation by this bacterium and alters the protein profile of S. mutans.

Construction of a DNA Vaccine Using Glycoprotein Gene and Its Expression Towards Increasing Survival Rate of KHV-Infected Common Carp (Cyprinus carpio)

Deoxyribonucleic acid (DNA) vaccine has recently been developed as an alternative vaccine against virus infection.This study was the first step of DNA vaccine development to protect cyprinids including common carp (Cyprinuscarpio) and fancy koi (Cyprinus carpio) from KHV (koi herpesvirus) infection in Indonesia. One of KHV glycoproteingenes, i.e. glycoprotein (GP) was ligated with Japanese medaka (Oryzias latipes) â-actin promoter to generatepAct/GP as a DNA vaccine. Fourty fish in body weight of 10-15 g/fish were individually injected by pAct/GP intomuscle in different dosage of 2.5 μg, 7.5 μg and 12.5 μg/100 μl phosphate buffer saline. Total RNA was extractedfrom the 12.5 μg of pAct/GP-injected fish muscle at 24, 48 and 67 hours post-injection to analyze GP expression byRT-PCR method. Potential of pAct/GP as DNA vaccine was examined by injecting KHV into the 30-days-vaccinatedfish. Both of possitive and negative control fish group were not vaccinated. Possitive control fish group wereinjected with KHV, but negative control fish group were not. KHV-challenged fish were reared for 1 month, and thedeath fish were calculated daily. Result of RT-PCR analysis showed that GP gene expression were detected at 3 dpost-injection. Expression of GP in the vaccinated fish groups helped to improve their survival rate after challengedby KHV. All of fish without DNA vaccination had dead 17 days after KHV injection. The results demonstrated thatpAct/GP had high potency to be used as a DNA vaccine against KHV infection in cyprinids.