Judul: Identification of Gram Negative Bacteria and Escherichia coli Antibiotic Resistance Test in Sugar Glider (Petaurus breviceps)
Abstrak: Sugar glider (Petaurus breviceps) adalah hewan peliharaan eksotis yang populer. Hewan ini dapat terserang berbagai macam penyakit, termasuk penyakit bakterial yang disebabkan oleh bakteri Gram negatif. Salah satu metode transmisi infeksi bakteri yaitu kontak melalui rute fekal-oral, sehingga bakteri penyebab penyakit dalam feses penting untuk diidentifikasi. Resistansi antibiotik dapat menyebabkan pengobatan yang tidak efektif. Bakteri Gram negatif diantaranya Escherichia coli dapat berperan sebagai donor dan resipien gen resistansi, sehingga dapat memperoleh maupun meneruskan gen resistansi ke bakteri lain. Penelitian ini bertujuan mengidentifikasi bakteri Gram negatif pada feses sugar glider dan menguji resistansi bakteri Escherichia coli terhadap beberapa jenis antibiotik. Identifikasi bakteri dilakukan dengan karakterisasi koloni, mikroskopis melalui hasil pewarnaan Gram, dan sifat biokimia bakteri. Uji resistansi dilakukan menggunakan metode difusi cakram Kirby Bauer dengan 7 macam antibiotik. Dari sampel feses sugar glider, teridentifikasi sejumlah bakteri Gram negatif yaitu Escherichia coli, Pseudomonas sp., Proteus sp., Salmonella sp., dan Shigella sp.. Penelitian ini menunjukkan bahwa Escherichia coli resistan terhadap antibiotik eritromisin, tetrasiklin, ampisilin dan streptomisin., Sugar gliders (Petaurus breviceps) are popular exotic pets. The animal can be infected by various diseases, including bacterial diseases caused by Gram-negative bacteria. One method of transmitting bacterial infections is contact via the fecaloral route, so it is important to identify disease-causing bacteria in feces. Antibiotic resistance can lead to ineffective treatment. Gram-negative bacteria Escherichia coli can act as donors and recipients of resistance genes, so they can acquire or pass on resistance genes to other bacteria. This study aims to identify Gram-negative bacteria in sugar glider feces and test the resistance of Escherichia coli bacteria to several types of antibiotics. Identification of bacteria is carried out by colony characterization, microscopic analysis using Gram staining results, and the biochemical characteristics of the bacteria. Resistance testing was carried out using the Kirby Bauer disc diffusion method with 7 types of antibiotics. From sugar glider feces samples, a number of Gram negative bacteria were identified, namely Escherichia coli, Pseudomonas sp., Proteus sp., Salmonella sp., and Shigella sp.. The results of the resistance test showed that Escherichia coli bacteria were resistant to erythromycin, tetracycline, ampicillin and streptomycin.
Keyword: antibiotik, bakteri Gram negatif, Escherichia coli, resistansi, sugar glider

Judul: Identification and Resistance of Enterococcus sp. Isolated from Sugar Glider (Petaurus breviceps) to Antibiotics
Abstrak: Sugar glider merupakan mamalia eksotik yang popular dipelihara belakangan ini. Tingginya frekuensi kontak secara langsung antar sugar glider dan manusia menjadi sumber penularan infeksi bakteri. Salah satu bakteri pada pencernaan sugar glider yang berpotensi sebagai patogen dan memiliki kemampuan multi-resistan adalah Enterococcus sp. Uji kepekaan bakteri terhadap antibiotik dapat menjadi informasi baru perkembangan sifat resistan bakteri dan dugaan pencemaran resistansi bakteri pada lingkungan dan pakan. Penelitian ini bertujuan mengidentifikasi keberadaan Enterococcus sp. pada sugar glider dan resistansinya terhadap antibiotik. Identifikasi koloni bakteri dari 10 sampel feses sugar glider secara makroskopis, mikroskopis, dan uji biokimia. Uji resistansi antibiotik menggunakan metode difusi cakram menurut Kirby Bauer dengan 7 antibiotik yang diuji. Koloni bakteri teridentifikasi sebagai 13 isolat Enterococcus sp., terdiri atas 8 isolat Enterococcus faecalis dan 5 isolat Enterococcus faecium. Enterococcus faecalis dan Enterococcus faecium resistan pada antibiotik asam nalidiksat, gentamisin, sefotaksim, trimetoprim-sulfametoksazol; intermediet pada eritromisin; sensitif pada oksitetrasiklin dan doksisiklin.
Keyword: antibiotik, enterococcus sp., resistansi, sugar glider

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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