Severe acute respiratory syndrome coronavirus-2 detection in domestic animals as a reservoir for the virus transmission to humans in Yogyakarta, Indonesia.

Background and Aim: The coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that attacks the respiratory and digestive tract. The SARS-CoV-2 showed systemic characteristics with various clinical symptoms from subclinical to fatal (causing death). Transmission of SARS-CoV-2 has been reported to occur from humans to pets (cats, dogs, tigers, ferrets, and poultry). Knowledge about the role of domestic animals in the transmission of SARS-CoV-2 to humans, and as reservoirs of this virus needs to be investigated further. This study aimed to detect the presence of SARS-CoV-2 in domestic animals such as dogs, cats, pigs, cows, birds, and bats that are often in contact with humans. Materials and Methods: A total of 157 samples, which included nasopharyngeal and oropharyngeal swabs, along with sera samples from domestic animals such as cats, pigs, cows, birds, and bats, were taken from Veterinary Hospitals, Veterinary Clinics, and farms around the Yogyakarta region. Detection of the virus was done using rapid detection of viral antigens, antibodies, and reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Results: The results showed that 5/157 (3.1%) samples found positive against the COVID-19 virus using a rapid antibody test; however, the results were negative on the rapid antigen and RT-PCR tests. Antibody-positive samples came from animals that had a history of household COVID-19 human infection. Conclusion: Thus, findings of the present study conclude that there is a potential for transmission of the COVID-19 virus between animals and humans.

In ovo inhibition of avian pox virus replication by mangosteen rind and red ginger ethanolic extracts.

BACKGROUND AND AIM: Avian pox is a contagious disease caused by the avian pox virus (APV). Mangostin and γ-mangostin in mangosteen rind (MR) and gingerol in red ginger (RG) exhibit antiviral activity. In this study, we evaluated the effect of MR and RG ethanolic extracts on APV based on pock lesions on the chorioallantoic membrane (CAM) of specific pathogen-free (SPF) embryonated chicken eggs (ECEs). MATERIALS AND METHODS: Three APVs from chicken isolates (C1, C2, and C3), one APV from a pigeon isolate (P), 1.5% and 3% MR ethanolic extract, 5% and 10% RG ethanolic extract, and a combination of 1.5% MR and 5% RG at 0.1 mL/egg were inoculated in ovo (7th day incubation, chorioallantoic route) in SPF ECEs. A control group inoculated in ovo with APV alone was also established. Each treatment consisted of three replicates. Parameters including embryo survival, CAM lesions, and average number of pock lesions were determined. RESULTS: In ovo inoculation of MR and RG ethanolic extracts was not harmful to the ECEs and did not induce CAM lesions. The average number of pock lesions in the control group (C1, C2, C3, and P) was 35, 14, 10, and 17, respectively, whereas in all treatment groups, the number was 0, except in the 5% RG group of C1, which had a value of 10. CONCLUSION: In ovo inoculation of 1.5% and 3% MR, 5% and 10% RG, and the combination of 1.5% MR plus 5% RG ethanolic extracts at 0.1 mL/egg inhibit APV by reducing the number of pock lesions on the CAM of the ECE.

Development of a coagglutination kit as a rapid test for diagnosing Newcastle disease in poultry.

BACKGROUND AND AIM: Newcastle disease (ND) is a viral infection that causes high mortality and economic loss in the poultry industry. The Office International des Epizooties (OIE) recommends several diagnostic methods for the detection of ND, including isolation and molecular tests. However, these detection methods are time-consuming and highly expensive. Therefore, this study was conducted to develop a coagglutination kit as a novel diagnostic tool for ND in the poultry industry. MATERIALS AND METHODS: Two adult male New Zealand White rabbits weighing 2.5 kg were vaccinated using ND life vaccine intraperitoneally. The vaccination was conducted once a week for 4 weeks with multilevel doses. Rabbits' serum was collected at week 6 and inactivated at 56°C for 30 min. The serum was precipitated using ammonium sulfate and reacted with protein A of Staphylococcus aureus to produce the agglutination kit for detecting ND virus. A total of 25 chickens suspected with ND infection from a local poultry farm in Yogyakarta were used as the test samples. The chickens were necropsied, and the brain, spleen, lung, intestine, and feces were collected. Half of these organs were subjected to tests using the coagglutination kit and reverse transcription-polymerase chain reaction (RT-PCR). The other half was processed for histopathology. Data were analyzed qualitatively. RESULTS: Of the 25 samples, 13 (52%) were positive for ND infection when tested using both the ND coagglutination kit and RT-PCR. The positive samples also exhibited several histopathological changes, including perivascular cuffing surrounding the cerebral blood-brain barrier, hemorrhagic pneumonia, splenitis, and necrotic hemorrhage enteritis. CONCLUSION: This study confirmed that the ND coagglutination kit could be used as a novel diagnostic tool for the detection of ND virus infection in the poultry industry.

Lab-Made Electronic Nose for Fast Detection of Listeria monocytogenes and Bacillus cereus.

The aim of this study is to determine the performance of a lab-made electronic nose (e-nose) composed of an array of metal oxide semiconductor (MOS) gas sensors in the detection and differentiation of Listeria monocytogenes (L. monocytogenes) and Bacillus cereus (B. cereus) incubated in trypticsoy broth (TSB) media. Conventionally, the detection of L. monocytogenes and B. cereus is often performed by enzyme link immunosorbent assay (ELISA) and polymerase chain reaction (PCR). These techniques require trained operators and expert, expensive reagents and specific containment. In this study, three types of samples, namely, TSB media, L. monocytogenes (serotype 4b American Type Culture Collection (ATCC) 13792), and B. cereus (ATCC) 10876, were used for this experiment. Prior to measurement using the e-nose, each bacterium was inoculated in TSB at 1 × 103-104 CFU/mL, followed by incubation for 48 h. To evaluate the performance of the e-nose, the measured data were then analyzed with chemometric models, namely linear and quadratic discriminant analysis (LDA and QDA), and support vector machine (SVM). As a result, the e-nose coupled with SVM showeda high accuracy of 98% in discriminating between TSB media and L. monocytogenes, and between TSB media and B. cereus. It could be concluded that the lab-made e-nose is able to detect rapidly the presence of bacteria L. monocytogenes and B. cereus on TSB media. For the future, it could be used to identify the presence of L. monocytogenes or B. cereus contamination in the routine and fast assessment of food products in animal quarantine.

Effect of mangosteen (Garcinia mangostana L.) peel extract as an antibiotic growth promoter on growth performance and antibiotic resistance in broilers.

BACKGROUND AND AIM: Antibiotic resistance poses a risk to human health and has therefore been the focus of research. One of the causes of this resistance is the use of antibiotics as feed additives for animal nutrition. The development of antibiotic resistance in poultry through nutrition feed has drawn attention to the need for alternative antibiotic growth promoters (AGPs). Mangosteen (Garcinia mangostana L.), as a natural source of bioactive phytochemicals, is a potential AGP, but the effect of mangosteen-based treatment on antibiotic resistance in poultry has not been reported to date. Therefore, the aim of this study was to evaluate the effects of mangosteen peel extract as an AGP on body weight gain, feed conversion rate (FCR), and the antibiotic resistance in broilers. MATERIALS AND METHODS: In this study, 30 1-day-old broiler chicks were divided into three groups. Group A (control) was not administered any treatment in the feed, Group B was treated with 0.3 g/kg colistin as the AGP in the feed, and Group C was treated with 2% mangosteen peel extract as the AGP in the feed; the treatments were administered for 30 days. The observed parameters included the effect of the treatments on body weight gain, feed intake, FCR, and the presentation of antibiotic resistance before and after the treatments (pre-treatment and post-treatment, respectively). RESULTS: Post-treatment, the body weight gain, and feed intake in the broilers were not significantly different among all the groups; however, the body weight gain and FCR were significantly different between the control group and the treatment groups in the 3rd week of treatment and were not significantly different between Groups B and C. The rate of antibiotic resistance to chloramphenicol increased significantly by 40% in Group B post-treatment, but no such increase was observed in Groups A and C. CONCLUSION: The findings of our study indicate that compared with using colistin as an AGP using mangosteen peel extract as a natural AGP did not have any significantly different effect on body weight gain, feed intake, and FCR (p>0.05) but had a significantly different effect on the rate of antibiotic resistance in broilers (p<0.05). This study indicates the usefulness of mangosteen for improving the overall growth and production performance of broilers without increasing their antibiotic resistance.

Cloning and sequencing gB, gD, and gM genes to perform the genetic variability of bovine herpesvirus-1 from Indonesia.

AIM: Previous research has shown that bovine herpesvirus-1 (BHV-1) in Indonesia was closely related to subtype-1 based on glycoprotein D genes. This study aimed to analyze the genetic variability of the BHV-1 isolated from the recent case in Indonesia not only based on gD but also other genes such as gB and gM and to study the homology and similarity of the sample to other BHV-1 isolated in other countries or regions. MATERIALS AND METHODS: Samples were drawn from the tracheal organ in recent field case and prepared for DNA extraction. The gB, gD, and gM were amplified using nested polymerase chain reaction (nPCR) with our specifically designed primer pair and based on the specified bands of 350 bp gB, 325 bp gD, and 734 bp gM confirmed as BHV-1. The PCR product was ligated into pGEM-T and transformed into competent Escherichia coli. The purified plasmid was subsequently sequenced. RESULTS: The virus sample isolated from the recent field case of infectious bovine rhinotracheitis (IBR) from Indonesia showed variability based on the gB, gD, and gM sequences. However, all of the genes had high similarity (98-100%) to BHV-1.2. CONCLUSION: The recent field case of IBR in Indonesia was similar to BHV-1.2.

Use of M2e ELISAs for longitudinal surveillance of commercial poultry in Indonesia vaccinated against highly pathogenic avian influenza.

In countries where highly pathogenic avian influenza virus (HPAIV) H5N1 is endemic and controlled by vaccination, post-vaccination serological monitoring is essential to differentiate vaccinated poultry from those that are infected. The objectives of this study were to validate two experimental ELISAs that detect antibodies raised against the M2e protein of avian influenza virus that can be used for DIVA purposes. Results from the sM2e and tM2e ELISAs were compared with other conventional tests for the detection of H5N1influenza virus (virus isolation and RT-PCR) using samples collected from 16 commercial flocks in Indonesia. These comprised vaccinated layers aged between 18 and 68 weeks old that were sampled at ten-weekly intervals. A small number of sera were positive in sM2e and tM2e ELISA, 14 (0.6%) and 17 (0.7%) respectively, with low OD420 (0.1-0.3), but only 4 sera were positive in both tests. At the flock level, the incidence of M2e positive sera was low (4%), well below previously established minimum of 40% for an HPAIV H5N1-infected flock. Conventional M and H5 gene RT-PCRs indicated that none of 16 flocks were infected at any time during the study. No virus was isolated from any of the 480 pooled swab samples, except from one, for which the combined data analysis suggest to be the result of a laboratory cross-contamination. Clinical disease, mortalities or reduction in production performance, indicative of field H5N1 challenge, were not observed either in any of the flocks. Birds from two surveyed flocks, challenged in the laboratory with an Indonesian HPAIV H5N1 developed M2e antibodies in 50% and 55% of surviving birds with OD420 in the range of 0.35-1.47 in tM2e ELISA, confirming the validity of the criteria established for use of M2e ELISA for DIVA purposes. Overall these results showed that the tM2e ELISA could be a useful monitoring tool to ascertain freedom from H5N1 infections in vaccinated commercial poultry.