Judul: Identification and Resistance Pattern of Klebsiella sp. Isolated from the Feces of the Bornean Orang Utan (Pongo pygmaeus) at Taman Safari Indonesia, Bogor
Abstrak: Orang utan merupakan satu-satunya kera besar yang masih bertahan di Wilayah Asia Tenggara. Saat ini, populasi orang utan di habitatnya terus mengalami penurunan. Diperkirakan selama 60 tahun terakhir populasi orang utan berkurang sebanyak 50%. Data mikrobiologi yang membahas resistansi bakteri Klebsiella sp. terhadap antibiotik pada feses orang utan kalimantan (Pongo pygmaeus) belum banyak dilakukan. Penelitian ini bertujuan untuk mengidentifikasi keberadaan bakteri Klebsiella sp. serta mengetahui pola resistansinya terhadap beberapa antibiotik pada feses P. pygmaeus. Metode penelitian terdiri dari isolasi, identifikasi, dan uji resistansi antibiotik. Hasil isolasi dan identifikasi ditemukan sebanyak tiga isolat (37,5%) yang positif bakteri Klebsiella sp. Berdasarkan uji sensitivitas, isolat Klebsiella sp. yang berasal dari feses P.pygmaeus sehat di Taman Safari Indonesia, Bogor, berhasil didapatkan dua pola resistansi berbeda yang memberikan gambaran adanya sensitivitas dan resistansi terhadap beberapa antibiotik. Klebsiella sp. telah mengalami resistan terhadap antibiotik golongan β-laktam dan masih sensitif terhadap antibiotik golongan aminoglikosida, tetrasiklin, dan fluorokuinolon., Orangutans are the only great apes that still survive in the Southeast Asian Region. Currently, the orangutans population in their habitat continues to decline. It is estimated that over the last 60 years, the orang utan population has decreased by 50%. Microbiological data discussing the resistance of Klebsiella sp. against antibiotics in the feces of the bornean orangutans (Pongo pygmaeus) has not been widely carried out. This study aims to identify the presence of Klebsiella sp. as well as know the pattern of resistance to several antibiotics in the feces of bornean orangutans. The research method consisted of isolation, identification, and antibiotic resistance testing. The results of isolation and identification found that three isolates (37.5%) were positive for Klebsiella sp. Based on the sensitivity test, Klebsiella sp. isolates which come from the feces of healthy P.pygmaeus in Taman Safari Indonesia, Bogor, two different patterns of resistance have been obtained which provide an overview of sensitivity and resistance to several antibiotics. Klebsiella sp. has experienced resistance to β-lactam class antibiotics and is still sensitive to aminoglycoside, tetracycline, and fluoroquinolone antibiotics.
Keyword: antibiotik, Klebsiella sp., Pongo pygmaeus, resistansi

Judul: Identification and Resistance of Salmonella sp. from Feces Sample of Bornean Orang Utan (Pongo pygmaeus) at Taman Safari Indonesia, Bogor.
Abstrak: Orang utan merupakan satu-satunya primata spesies kera besar yang hidup di Asia. Seluruh spesies orang utan dikategorikan ke dalam kelompok Appendix 1 yakni kelompok satwa yang dilindungi penuh dari segala bentuk perdagangan karena terancam punah oleh Convention on International Trade of Endangered Species of Fauna and Flora (CITES). Status orang utan sebagai hewan yang terancam punah ini menjadikan masalah kesehatannya perlu mendapat perhatian lebih, salah satunya adalah penyakit gastrointestinal yang disebabkan oleh Salmonella sp. Sejauh ini, data mikrobiologi terkait gangguan saluran pencernaan dan kejadian resistansi antibiotik pada orang utan belum banyak dipublikasikan. Penelitian ini bertujuan mengetahui keberadaan bakteri Salmonella sp. serta pola resistansinya pada feses orang utan kalimantan (Pongo pygmaeus) di Taman Safari Indonesia, Bogor. Sebanyak 10 sampel feses diambil dari orang utan dengan kondisi sehat dan tidak sedang mengalami gangguan pencernaan. Hasil isolasi dan identifikasi menunjukkan sebanyak 6 dari 10 sampel menunjukkan hasil yang positif terhadap Salmonella sp. Uji resistansi antibiotik dilakukan dengan menggunakan metode Kirby-Bauer Disk Diffusion Test menggunakan 7 macam antibiotik dari golongan yang berbeda-beda. Hasil uji resistansi menunjukkan bahwa Salmonella sp. 100% masih sensitif terhadap trimetoprim-sulfametoksazol, kloramfenikol, trimetoprim, dan tetrasiklin. Sementara itu, sebanyak 83,3% isolat menunjukkan resistansi terhadap ampisilin dan 33,3% terhadap streptomisin., Orang utans are the only primates of the great ape species that live in Asia. All orang utan species are categorized into the Appendix 1 group, which is an animal group which is fully protected from all forms of trade since it is threatened with extinction by Convention on International Trade of Endangered Species of Fauna and Flora (CITES). Furthermore, the status of the orang utan as an endangered animal makes its health problems need more attention, one of which is gastrointestinal disease caused by Salmonella sp. To date, microbiological data which is related to digestive tract disorders and the incidence of antibiotic resistance in orang utans have not been widely published. This study aims to determine the presence of Salmonella sp. and the pattern of resistance in the feces of the Bornean orang utan (Pongo pygmaeus) at Taman Safari Indonesia, Bogor. A total of 10 stool samples were taken from orang utans in healthy condition and they were not experiencing digestive disorders. The results of isolation and identification indicate that as many as 6 of 10 samples show positive results on Salmonella sp. Antibiotic resistance test was conducted by using the Kirby-Bauer Disk Diffusion Test method with 7 different antibiotics from different groups. In addition, the results of the resistance test show that Salmonella sp. 100% still sensitive to trimethoprim-sulfamethoxazole, chloramphenicol, trimethoprim, and tetracycline. Meanwhile, 83,3% of isolates show resistance to ampicillin and 33,3% to streptomycin.
Keyword: antibiotik, orang utan, resistansi antibiotik, Salmonella sp.

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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