Judul: Distribution of Encoding Genes Ampicillin Resistance in Salmonella spp. Isolated from Chicken Carcasses
Abstrak: Penggunaan ampisilin dengan tujuan bukan untuk pengobatan (non-terapeutik) dapat menimbulkan antimicrobial resistance (AMR). Resistensi terhadap ampisilin dapat dipengaruhi oleh keberadaan gen-gen penyandi resistensi ampisilin. Penelitian ini bertujuan mendapatkan data gen-gen penyandi resistensi ampisilin beserta gen dominannya pada Salmonella spp. asal karkas ayam. Terdapat tujuh belas isolat Salmonella spp. asal karkas ayam yang digunakan dalam penelitian ini. Penelitian ini terdiri dari tiga tahapan kerja, yaitu ekstraksi dan analisis kemurnian DNA Salmonella spp., deteksi gen-gen penyandi resitensi ampisilin, dan analisis korelasi antara fenotipe dan genotipe serta frekuensi gen tertinggi. Deteksi gen-gen penyandi sifat resistensi ampisilin dilakukan menggunakan polymerase chain reaction (PCR). Hasil deteksi gen penyandi resistensi ampisilin menunjukkan 17 (100%) isolat memiliki gen blaTEM dan blaTEM-1, 16 (94,1%) memiliki gen blaCTX-M-2, 11 (64,7%) memiliki gen blaCTX-M-15, dan tidak ada isolat yang memiliki gen blaCMY-2. Korelasi antara sifat resisten (fenotipe) dengan keberadaan gen penyandi resistensi ampisilin (genotipe) menunjukkan bahwa gen blaCTX-M-15 memiliki persentase korelasi tertinggi dan merupakan gen dominan penyandi resistensi ampisilin pada Salmonella spp. asal karkas ayam., The use of ampicillin for non-therapeutic purposes can lead to antimicrobial resistance (AMR). Resistance to ampicillin can be influenced by the presence ampicillin resistance coding genes. This study aims to obtain data on ampicillin resistance coding genes and their dominant genes in Salmonella spp. isolated from chicken carcasses. There were seventeen isolates of Salmonella spp. isolated from chicken carcasses used in this study. This study consisted of three stages of work, namely extraction and purification analysis of Salmonella spp. DNA, detection of ampicillin resistance coding genes, and correlation analysis between phenotype and genotype and the highest gene frequency. Detection of the genes coding for ampicillin resistance was carried out using the polymerase chain reaction (PCR). The results of the detection ampicillin resistance gene coding showed that 17 (100%) isolates had the blaTEM and blaTEM-1 genes, 16 (94.1%) had the blaCTX-M-2 gene, 11 (64.7%) had the blaCTX-M-15 gene, and none of the isolates had the blaCMY-2 gene. The correlation between resistance (phenotype) and ampicillin resistance coding genes (genotype) showed that the blaCTX-M-15 gene had the highest correlation percentage and was the dominant gene encoding ampicillin resistance in Salmonella spp. isolated from chicken carcasses.
Keyword: ampicillin, AMR, chicken carcasses, PCR, Salmonella spp.

Judul: Identifikasi Sifat Resistensi Antibiotik dan Deteksi Gen Penyandinya pada Salmonella spp. Asal Karkas Ayam Kampung
Abstrak: Daging ayam kampung sudah banyak dikonsumsi di Indonesia seperti halnya ayam ras. Namun, pemeliharaan secara ekstensif memungkinkan paparan bakteri yang bersifat multidrug-resistant (MDR) pada ayam kampung, termasuk melalui transfer gen horizontal. Penelitian ini bertujuan menghubungkan sifat resisten dengan keberadaan gen penyandi resistensi antibiotik pada Salmonella spp. yang diisolasi dari karkas ayam kampung. Identifikasi sifat resisten dilakukan dengan metode difusi cakram Kirby-Bauer dan deteksi gen resistensi antibiotik pada tujuh belas isolat Salmonella spp. dilakukan dengan PCR. Semua (17 dari 17) isolat Salmonella sensitif terhadap ampisilin dan kloramfenikol. Salmonella spp. paling resisten terhadap eritromisin (82,4%; 14 dari 17), sementara penurunan sensitivitas (sifat intermediet) banyak terjadi pada oksitetrasiklin (82,4%; 14 dari 17) dan siprofloksasin (53,0%; 9 dari 17). Salmonella Typhimurium menunjukkan pola resistensi terhadap lebih banyak golongan antibiotik dibandingkan dengan S. Weltevreden dan S. Newport. Gen blaTEM, tetG, cmlA, dan gyrA terdeteksi pada semua (17 dari 17) isolat Salmonella spp. Sifat resisten dan keberadaan gen penyandi resistensi antibiotik tidak selalu berhubungan satu sama lain. Penelitian ini dapat memberikan informasi yang bermanfaat mengenai penyebaran fenotipe dan genotipe resistensi antibiotik pada Salmonella spp. dari ayam kampung., Kampung chicken meats have been widely consumed in Indonesia as well as broiler chicken. However, the extensive rearing allowed exposure of multidrug-resistant (MDR) bacteria to kampung chicken, including through horizontal gene transfer. This study aimed to correlate resistance phenotype with the presence of genes-encoding antibiotics resistance in Salmonella spp. isolated from kampung chicken carcasses. Identification of resistance phenotype was carried out by Kirby-Bauer disc diffusion method, while detection of antibiotics resistance genes in seventeen isolates of Salmonella spp. was carried out by PCR. All (17 of 17) isolates of Salmonella were susceptible to ampicillin and chloramphenicol. Salmonella spp. was most resistant to erythromycin (82.4%; 14 of 17), while the decreased susceptibility (intermediate category) most occurred in oxytetracycline (82.4%; 14 of 17) and ciprofloxacin (53.0%; 9 of 17). Salmonella Typhimurium showed a resistance pattern to more antibiotic groups than S. Weltevreden and S. Newport. The blaTEM, tetG, cmlA, and gyrA genes were present in all (17 of 17) isolates of Salmonella spp. Resistance phenotype and the presence of genes-encoding antibiotics resistance were not always related to each other. This study could provide beneficial information regarding the distribution of antibiotics resistance phenotype and genotype in Salmonella spp. from kampung chicken.
Keyword: antibiotic, kampung chicken, multidrug-resistant, PCR, Salmonella

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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