Judul: Identification of Enterococcus sp. and Antibiotic Resistance Testing in Sumatran Orangutans (Pongo abelii) at the Indonesian Safari Park
Abstrak: Populasi orang utan sumatra (Pongo abelii) saat ini mengalami penurunan sebanyak 80%. Hal ini disebabkan oleh berbagai faktor, diantaranya semakin menyempit habitatnya akibat aktivitas manusia yang tidak bertanggung jawab, perdagangan ilegal, dan juga disebabkan oleh penyakit yang diakibatkan oleh infeksi bakteri. Tujuan penelitian ini adalah untuk mengisolasi dan mengidentifikasi Enterococcus sp. pada feses orang utan sumatra di Taman Safari Indonesia dan menguji resistansi bakteri Enterococcus sp. terhadap beberapa jenis antibiotik. Penelitian ini dilakukan di Laboratorium Bakteriologi, Divisi Mikrobiologi Medik, Sekolah Kedokteran Hewan dan Biomedis, Institut Pertanian Bogor. Sampel feses yang digunakan dalam penelitian ini diambil dari 10 ekor orang utan sumatra di Taman Safari Indonesia. Feses orang utan sumatra diambil kemudian dilanjutkan dengan metode isolasi pada media Enterococcus faecalis (EF) agar, Tryptic Soy Agar (TSA), dan Blood Agar (BA), diidentifikasi dengan pewarnaan Gram, uji KOH 3%, uji biokimia, serta dilanjutkan dengan prosedur uji resistansi antibiotik. Hasil penelitian mengindikasikan bahwa sebanyak 6 isolat teridentifikasi E. faecium dan 4 isolat lainnya teridentifikasi E. faecalis. Hasil uji resistansi bakteri Enterococcus sp. terhadap tujuh jenis antibiotik menunjukkan bahwa sebanyak 9 isolat resistan terhadap ceftazidime dan cefotaxime, sebanyak 2 isolat resistan terhadap streptomisin, dan sebanyak 1 isolat resistan terhadap eritromisin., The Sumatran orangutans (Pongo abelii) population is declining by 80% due to habitat loss from human activities, illegal trade, and bacterial infections. The aim of this study was to isolate and identify Enterococcus sp. in the feces of Sumatran orangutans at Taman Safari Indonesia and tested the resistance of Enterococcus sp. bacteria to several types of antibiotics. This research was conducted at the Bacteriology Laboratory, Medical Microbiology Division, School of Veterinary Medicine and Biomedicine, IPB. The feces samples used in this study were taken from 10 Sumatran orangutans at Taman Safari Indonesia then continued with the isolation method on Enterococcus faecalis (EF) agar media, TSA, and BA, identified by Gram staining, 3% KOH test, biochemical test, and continued with the procedure antibiotic resistance test. The results of the study indicated that 6 isolates were identified as E. faecium and 4 other isolates were identified as E. faecalis. The results of the bacterial resistance test Enterococcus sp. against seven types of antibiotics showed that 9 isolates were resistant to ceftazidime and cefotaxime, 2 isolates were resistant to streptomycin, and 1 isolate was resistant to erythromycin.
Keyword: Enterococcus sp., identification, isolation, resistance, Sumatran orangutan

Judul: Resistance Test of Escherichia coli Pathogen from  Feces Sample of Bornean Orangutan (Pongo pygmaeus) at Taman Safari Indonesia-Bogor
Abstrak: Orang utan merupakan salah satu primata dan satu-satunya kera besar yang hidup di Asia. Gangguan saluran pencernaan pada orang utan biasanya berupa diare yang disebabkan oleh bakteri enteropatogen E. coli. Pengobatan dengan antibiotik pada orang utan harus mempertimbangkan sensitivitas bakteri terhadap antibiotik. Penelitian ini bertujuan mengetahui gambaran resistansi Escherichia coli patogen pada sampel feses orangutan kalimantan (Pongo pygmaeus) di Taman Safari Indonesia – Bogor terhadap beberapa antibiotik. Sebanyak 10 sampel diisolasi dan diidentifikasi keberadaan E. coli patogen dan sebanyak 10 isolat terdeteksi sebagai E. coli patogen. Uji resistansi dilakukan dengan metode Kirby-Baurer Disk Diffusion Test menggunakan 7 antibiotik yang berbeda. Hasil uji menunjukkan 20% isolat telah resistan terhadap tetrasiklin, 30% isolat resistan terhadap antibiotik streptomisin, trimetoprim dan trimetoprim-sulfametoksazol, dan 90% telah resistan terhadap ampisilin. Sementara itu 100% isolat sensitif terhadap kloramfenikol, 70% sensitif terhadap trimetoprim dan trimetoprim-sulfametoksazol, serta 50% sensitif terhadap siprofloksasin. Antibiotik yang menunjukkan hasil resistan tidak direkomendasikan untuk pengobatan infeksi oleh E. coli pada orang utan., Orangutans are one of the primates and the only great apes which live in Asia. Gastrointestinal problem in orangutans usually characterized by diarrhea which comes from enteropathogenic bacteria E. coli. Moreover, treatment with antibiotics in orangutans should take into account the sensitivity of the bacteria to antibiotics. The aim of this study is to describe the resistance of pathogenic Escherichia coli in fecal samples of the Bornean orangutan (Pongo pygmaeus) at Taman Safari Indonesia – Bogor to several antibiotics. A total of 10 samples were isolated and identified the presence of pathogenic E. coli and as many as 10 isolates were detected as pathogenic E. coli. Moreover, the resistance test was conducted by using the Kirby-Bauer Disk Diffusion Test method using 7 different antibiotics. The test results show that 20% of the isolates were resistant to tetracycline, 30% of the isolates were resistant to the antibiotics streptomycin, trimethoprim and trimethoprim-sulfamethoxazole, and 90% were resistant to ampicillin. Meanwhile, 100% of isolates were sensitive to chloramphenicol, 70% sensitive to trimethoprim and trimethoprim-sulfamethoxazole, and 50% sensitive to ciprofloxacin. Antibiotics that show resistance are not recommended for the treatment of infections by Escherichia coli in orangutans.
Keyword: antibiotic, Escherichia coli, orangutan, resistance

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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