A preliminary metagenomics study of bacteria present in the dirt of Swiftlet farmhouses based on nitrite levels in edible bird's nest on Sumatera Island, Indonesia

Research (Published online: 26-07-2022)

26. A preliminary metagenomics study of bacteria present in the dirt of Swiftlet farmhouses based on nitrite levels in edible bird's nest on Sumatera Island, Indonesia

Platika Widiyani, Mirnawati B. Sudarwanto, Hadri Latif, Denny Widaya Lukman, Daniel Thong and Puji Rahayu

Veterinary World, 15(7): 1798-1803

ABSTRACT

Background and Aim: Since the past decade, metagenomics has been used to evaluate sequenced deoxyribonucleic acid of all microorganisms in several types of research. Nitrite contamination originates from the natural environment in Swiftlet farmhouses (SFHs) and can influence nitrite levels in edible bird's nest (EBN). It is strongly speculated that the conversion process into nitrite is influenced by the bacteria present in SFHs. Nitrite can cause adverse effects on human health. The previous research has focused on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. This study aimed to a metagenomics analysis of bacteria present in the dirt of SFHs and evaluated nitrite levels in EBN on Sumatera Island.

Materials and Methods: In total, 18 SFHs on Sumatera Island were selected, and EBN and dirt samples were collected from each SFH, resulting in 18 EBN and 18 dirt SFH samples. Raw uncleaned white EBN and dirt from three areas of SFH were collected. The samples were analyzed for nitrite levels using a spectrophotometer, and the metagenomics sequencing of SFH dirt samples was performed using the MinIon nanopore method. The sequenced data were analyzed using the EPI2ME software.

Results: Of the 18 raw uncleaned white EBN samples, 9 (50%) had <30 ppm nitrite levels. The top five bacterial genera in SFH dirt samples in Group A (nitrite levels >30 ppm) were Aeromonas, Escherichia, Acinetobacter, Arcobacter, and Acetoanaerobium. Those in Group B (nitrite levels <30 ppm) were Aeromonas, Pseudomonas, Shewanella, Escherichia, and Acinetobacter. There were 12 genera of nitrifying bacteria in Group A and 8 in Group B. The total cumulative read of nitrifying bacteria in Groups A and B were 87 and 38 reads, respectively.

Conclusion: This is the first study to show that characteristic bacteria present in the dirt of SFHs might significantly influence the conversion from nitrogen to nitrite. Approximately 50% of raw uncleaned EBN samples had <30 ppm nitrite levels. Aeromonas was the most dominant bacterial genus found in Groups A and B. The variations in genus and cumulative reads nitrifying bacteria in group A were greater than those in Group B. This study provides information on the characteristics of bacteria that may influence the nitrite conversion process in SFHs. Metagenomics data were obtained from the reading using the software EPI2ME. Further research is needed on the bacterial target species that can convert nitrite in SFHs.

Keywords: analysis, edible bird's nest, metagenomic, nitrite, Swiftlet.

Use of proposed systolic and myocardial performance indices derived from simultaneous ECG and PCG recordings to assess cardiac function in healthy Beagles

Research (Published online: 25-07-2022)

25. Use of proposed systolic and myocardial performance indices derived from simultaneous ECG and PCG recordings to assess cardiac function in healthy Beagles

Karlo Romano B. Gicana, Chirutchaya Pinidmontree, Kitchanan Kosalathip, Siraphop Sirirut, Siripen Komolvanich, Sariya Asawakarn, Walasinee Sakcamduang, Phornphop Naiyanetr and Kittipong Tachampa

Veterinary World, 15(7): 1785-1797

ABSTRACT

Background and Aim: Cardiac time intervals (CTIs) can provide important information on the electrical and mechanical properties of the heart. We hypothesized that cardiac function can be described using the combined power of electrocardiography (ECG) and phonocardiography (PCG) signals. This study aimed to (1) validate a novel custom device in measuring CTI parameters; (2) compare CTI parameters with a commercially available device and standard transthoracic echocardiography (STE); and (3) compare calculated systolic performance index (SPI) and myocardial performance index (MPI) with Tei index from the STE.

Materials and Methods: This study determined CTIs based on simultaneous ECG and PCG recordings in 14 healthy Beagle dogs using the custom-built device. These CTI parameters were compared with a commercially available device (Eko DUO ECG + Digital Stethoscope; Eko DUO) and the STE. Agreement of CTI parameters between the custom device and the commercially available device or STE was evaluated. Calculated SPI and MPI based on Wigger's diagram were proposed, compared with SPI and Tei index, and correlated with STE parameters.

Results: We found that the ECG and PCG parameters measured from the custom-built device did not differ from the commercially available device and the STE. By combining ECG and PCG signals, we established CTI parameters in healthy dogs including indices for systolic function (SPI: QS1/S1S2) and global cardiac function {F1 ([QS1+S2]/S1S2), F2 ([RS1+S2]/S1S2), and F3 (RS1 + [QS2-QT]/S1S2)}. The SPI, F2, and F3 were comparable with echocardiographic parameters describing systolic (Pre-ejection period/left ventricular ejection time [LVET]) and Tei index ([MCOdur-LVET]/ LVET), respectively. Only SPI and F3 were correlated significantly with MCOdur and heart rate, respectively.

Conclusion: We have validated the use of the custom-built device to describe CTIs that are comparable to the commercially available device and STE in healthy Beagles. The proposed SPI and MPI derived from CTI parameters can be useful in clinical practice to describe the cardiac function, especially in areas where access to STE is constrained.

Keywords: cardiac time intervals, dogs, electrocardiography, healthy, phonocardiography.

Serological survey of Toxoplasma gondii infection in cats in Khon Kaen, Northeast Thailand

Research (Published online: 25-07-2022)

24. Serological survey of Toxoplasma gondii infection in cats in Khon Kaen, Northeast Thailand

Natthika Lakhamsen, Chalipa Chaisongkhram, Yanika Pattarasuplerk, Arayaporn Macotpet, Suvaluk Seesupa, Nitiwadee Lertitthikul, Pattaraanong Bupata and Panisara Kunkitti

Veterinary World, 15(7): 1779-1784

ABSTRACT

Background and Aim: Toxoplasmosis is a zoonosis caused by Toxoplasma gondii. Cats are known to be the definitive hosts that can excrete these environmentally resistant oocysts. Other mammals, avians, and even humans can serve as the intermediate host. T. gondii infection is often asymptomatic in healthy individuals; however, it could result in serious health problems in immunocompromised and pregnant individuals. This study investigated the occurrence of T. gondii infection in cats in Khao Suan Kwang and Mueang Khon Kaen.

Materials and Methods: In total, 100 serum samples from cats, that is, 62 owned cats (31 males and 31 females) and 38 adopted stray cats (21 males and 17 females), were examined for antibodies against T. gondii through rapid immunochromatographic tests (ICT). Owners were asked to sign a consent form and answer the questionnaires before sample collection. Demographic information about the cats and their owners was also recorded.

Results: The overall seroprevalence of cats positive for T. gondii antibodies was found to be 5%. Notably, the Toxoplasma antibody prevalence was significantly higher in the adopted stray cats (10.53% [4/38]) that roamed the zoo than in the owned cats (1.61% [1/62]) (p > 0.05). No significant difference was observed between male (8.33%) and female (1.92%) cats. The cat owners' questionnaire revealed that more than half had never heard of toxoplasmosis before (67.7%), whereas 30.6% knew nothing about the disease transmission routes.

Conclusion: This study presented a low seroprevalence of antibodies to T. gondii in owned cats from the Mueang Khon Kaen District, whereas high seroprevalence was detected in the adopted stray cats from Khao Suan Kwang. Adopted stray cats can have a higher potential for T. gondii infection; thus, they could be a source of toxoplasmosis transmission to humans. Therefore, it is essential to control the number of stray cats, and a screening test for antitoxoplasmosis could be recommended before adoption. Although the total seroprevalence was noted to be low, the zoonotic disease was present. Therefore, raising the community's awareness and knowledge might reduce the disease transmission from animals to humans.

Keywords: adopted stray cat, feline, Khon Kaen, toxoplasmosis, zoonoses.

Comparison of ITS-1 and TBR-1/2 primer sensitivity for the detection of Trypanosoma evansi local isolates in experimental rats using a polymerase chain reaction

Research (Published online: 24-07-2022)

23. Comparison of ITS-1 and TBR-1/2 primer sensitivity for the detection of Trypanosoma evansi local isolates in experimental rats using a polymerase chain reaction

Endang Suprihati, Lucia Tri Suwanti, Aditya Yudhana and Andika Indra Kusumaningrum

Veterinary World, 15(7): 1772-1778

ABSTRACT

Background and Aim: Surra is caused by Trypanosoma evansi. The detection method using conventional parasitological tests has not always shown positive results in blood parasite detection, although the livestock has presented with clinical signs. Therefore, a fast and accurate diagnosis is necessary to prevent the disease predominately in field isolates. This study aimed to investigate the sensitivity of molecular detection method using two different specific primers, namely, Internal Transcribed Spacer 1 (ITS-1) and Trypanosoma brucei repeat 1/2 (TBR-1/2) against T. evansi field isolates from Banten Province, Indonesia.

Materials and Methods: The isolates of T. evansi used in this study were collected from Banten Province and cultured and preserved by the National Research Center for Veterinary Science, Indonesia. Eighteen experimental rats were divided into three equal groups, which were categorized as control, 1 × 101, and 1 × 104 infective doses. The isolates were injected into all experimental albino rats intraperitoneally. All samples were tested using conventional blood smear, card agglutination test (CATT), and polymerase chain reaction (PCR) method.

Results: The results of the CATT examination in all treatments showed negative results. However, PCR results showed that two different primers, namely, ITS-1 and TBR-1/2 had been successfully detected T. evansi from infected experimental rats, proven by positive PCR band appeared in 480 base pairs (bp) and 164 bp, respectively.

Conclusion: Based on the molecular diagnostic test using PCR method, TBR-1/2 primer is more sensitive to detect T. evansi compared to ITS-1 primer. The present finding provides preliminary data for studying the efficiency of different primers if practically applied as a standard diagnostic test for trypanosomiasis, especially in Indonesian livestock.

Keywords: infectious disease, ITS-1, surra, TBR-1/2, tropical disease.

Cellular immune response of Staphylococcus aureus enterotoxin B in Balb/c mice through intranasal infection

Research (Published online: 24-07-2022)

22. Cellular immune response of Staphylococcus aureus enterotoxin B in Balb/c mice through intranasal infection

Hidayatun Nisa Purwanasari, Amanda Tri Utami Permatasari, Fajar Budi Lestari, Madarina Wasissa, Khusnan Zaini and Siti Isrina Oktavia Salasia

Veterinary World, 15(7): 1765-1771

ABSTRACT

Background and Aim: Staphylococcus aureus produces various superantigen exotoxins, including staphylococcal enterotoxin B (SEB). It causes fatal anaphylactic reactions and toxic shock. This study aimed to evaluate the reaction of leukocytes and histopathological changes in the respiratory organs of Balb/c mice after intranasal infection with enterotoxigenic S. aureus (SEB).

Materials and Methods: The presence of the seb gene in S. aureus was established in this study using polymerase chain reaction-specific primer. Two groups of 8-week-old male Balb-c mice consist of six mice in each group. The treated group was infected with 50 μL and 100 μL of SEB intranasal on days 1 and 14, respectively. NaCl was administered in the second group and was considered as a control group. Blood samples were collected through the retro-orbital plexus on days 1, 4, 7, 14, and 22 after infections. Total cell counts were analyzed with an independent sample t-test and compared using the statistical package for the social sciences (SPSS) version 16.0 (IBM Corp., NY, USA). The infected tissues of the respiratory organ were observed descriptively and compared to the control group.

Results: The seb gene with a molecular size of 478 bp, indicating the SEB strain, is present in S. aureus used in this study. Intranasal administration of SEB showed increased leukocytes, lymphocytes, monocytes, and eosinophils on day 22 post-infection. Significant leukocytosis was seen on days 6 and 14; lymphocytosis on days 1, 4, 6, and 16; and eosinophilia on days 6, 14, and 22 compared with the control group (p > 0.05). In contrast, the neutrophil decreased after an increase of immature band cells compared to the control group, indicating a severe acute infection with SEB. The lungs and trachea of the test group had an inflammatory cell accumulation in the respiratory organ.

Conclusion: Intranasal route infection of S. aureus containing seb gene significantly induced the cellular immune response and caused pathological changes in the respiratory tissues of the Balb/c mice model. The hematological changes were aligned with marked pathological changes in the respiratory tract. Balb/c mice could be an excellent experimental model to study toxic and anaphylactic shock against SEB to define the future therapeutic agents.

Keywords: enterotoxin B, hematology, histopathology, intranasal, Staphylococcus aureus.

Aerolysin gene characterization and antimicrobial resistance profile of Aeromonas hydrophila isolated from milkfish (Chanos chanos) in Gresik, Indonesia

Research (Published online: 23-07-2022)

21. Aerolysin gene characterization and antimicrobial resistance profile of Aeromonas hydrophila isolated from milkfish (Chanos chanos) in Gresik, Indonesia

Faisal Fikri, Dhandy Koesoemo Wardhana, Agus Purnomo, Shafia Khairani, Shekhar Chhetri and Muhammad Thohawi Elziyad Purnama

Veterinary World, 15(7): 1759-1764

ABSTRACT

Background and Aim: Motile Aeromonas septicemia is a crucial disease in freshwater fish. Aeromonas hydrophila is a disease agent associated with sporadic fish mortality, food safety, and public health. This study aimed to estimate the prevalence and the presence of the aerolysin gene and antimicrobial resistance profile of A. hydrophila isolated from milkfish in Gresik, Indonesia.

Materials and Methods: A total of 153 milkfish gill samples were collected from 16 locations in Gresik and then cultured and identified using biochemical tests. The aerolysin gene was investigated using a polymerase chain reaction, and antimicrobial resistance profiles of the recovered isolates were investigated.

Results: Of the 153 examined samples, 35 (22.9%) were confirmed positive for A. hydrophila and 22 (62.9%) presented the aerolysin gene. The recovered isolates were resistant to the following antibiotics: Amoxicillin (62.9%), tetracycline (60%), streptomycin (54.3%), cefotaxime (51.4%), gentamycin (31.4%), kanamycin (28.6%), erythromycin (25.7%), chloramphenicol (20%), and trimethoprim (14.3%). Meanwhile, only ciprofloxacin, nalidixic acid, and imipenem were indicated as susceptible.

Conclusion: The presence of the aerolysin gene is vital in determining the virulence of A. hydrophila. The study results indicated a high aerolysin gene prevalence. In addition, this study emphasized antibiotic use monitoring, food safety improvement, and negative impact reduction on human health and the environment.

Keywords: aerolysin gene, Aeromonas hydrophila, antimicrobial resistance, milkfish, public health.

Bio-efficacy of Mangifera leaf extracts on mortality of Aedes aegypti and inhibition of egg hatching

Research (Published online: 23-07-2022)

20. Bio-efficacy of Mangifera leaf extracts on mortality of Aedes aegypti and inhibition of egg hatching

Nur Mahdi, Muhammad Rasyid Ridha, Deni Setiawan, Muhammad Riki Shindi Praristiya, Nita Rahayu and Bayu Purnama Atmaja

Veterinary World, 15(7): 1753-1758

ABSTRACT

Background and Aim: To develop an environmentally friendly alternative to mosquito larvicides for vegetables, leaf extracts of Mangifera laurina, Mangifera casturi, Mangifera indica, Mangifera odorata, Mangifera caesia, and Mangifera foetida were prepared. This study aimed to determine the biological efficacy of several Mangifera leaf extracts on the mortality of Aedes aegypti mosquito and the inhibition of egg hatching.

Materials and Methods: Extraction was performed in an organic solvent (methanol) using a Soxhlet extractor. The larvicidal potential of six leaves of Mangifera essential oil was evaluated against the third instar larvae of A. aegypti at concentrations of 1500, 2000, 3000, and 5000 ppm using the World Health Organization protocol. After Probit analysis, the 48 h LC50 and LC90 values of the essential oils were determined. The inhibitory effect on egg hatching was also tested at 160, 320, 480, and 640 ppm.

Results: The extraction of essential oils from several Mangifera species had excellent larvicidal activity and inhibitory activity against A. aegypti egg hatching. The LC50/LC90 values were: M. casturi, 241/1964 ppm; M. laurina, 2739/4035 ppm; and M. caesia, 1831/2618 ppm. The inhibitory effect on hatching was 78% for M. foetida, 70% for M. caesia, and 59% for M. casturi.

Conclusion: The test results indicate the potential of some Mangifera species for use as larvicides and inhibitors of egg hatching; thus, they have the potential to control A. aegypti in the early stages of development.

Keywords: Aedes aegypti, bio-efficacy, leaf extracts, Mangifera.