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.

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.