Judul: Identification and Pattern of Antibiotic Resistance of Pseudomonas spp. Isolated from Orangutan (Pongo Pygmaeus) at Bogor Indonesia Safari Park
Abstrak: Pseudomonas spp. is a lactose-negative gram-negative bacteria that contributes to several infections including air sacculitis in orangutans due to its having the largest air sac compared to most nonhuman primates. This research was designed to study and analyze the identification and the pattern of antibiotic resistance of Pseudomonas spp. Identification of Pseudomonas includes KOH 3% test, oxidase test, TSIA test, urea test, IMViC test Indole, Methyl-Red, Voges-Proskauer, and Citrate) and carbohydrate fermentation test. Pattern of antibiotic resistance includes five different types of antibiotics from different antibiotic classes which are ampicillin from β- lactam, gentamicin from aminoglycoside, tetracycline from tetracycline, enrofloxacin from fluoroquinolone, and chloramphenicol from phenicol class. As the results, identification of Pseudomonas spp. showed three suspected isolates of Pseudomonas spp. Patterns of antibiotic resistance was carried out by using Kirby-Baurer method which uses agar disk diffusion resulted in two of the isolates that were mostly similar in pattern, resistant to only ampicillin and are sensitive towards tetracycline, enrofloxacin, chloramphenicol, and gentamicin meanwhile the other one of the isolate differ, resistant to ampicillin, tetracycline, enrofloxacin, and chloramphenicol and is sensitive towards gentamicin. In conclusion, feces samples of orangutans revealed three suspected Pseudomonas spp. and showed resistance on ampicillin and sensitive to gentamicin. The study of antibiotic resistance patterns is crucial for future antibiotic selection.
Keyword: antibiotic resistance, gram-negative bacteria, Kirby-Baurer method, Pseudomonas spp.

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: 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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