Judul: Resistance of Escherichia coli Isolates in Chicken Soto Meat Sold Around Dramaga Campus of IPB University
Abstrak: Makanan khususnya yang dijual di pinggir jalan rentan terkontaminasi oleh Escherichia coli (E. coli) salah satunya adalah soto ayam. Escherichia coli patogen sering kali bersifat resistan terhadap antibiotik yang mengakibatkan bahaya bagi manusia karena infeksi yang semula mudah diobati dengan antibiotik kini menjadi kurang efektif. Tujuan penelitian ini yaitu mengidentifikasi resistansi antibiotik dari bakteri E. coli yang diisolasi dari daging ayam suwir soto ayam yang dijual di lingkar Kampus IPB, Dramaga, Bogor. Sampel yang digunakan sebanyak 21 isolat yang telah diuji positif terhadap keberadaan E. coli. Pengujian resistansi antibiotik menggunakan metode Kirby-Bauer disk diffusion dan mengacu pada Clinical Laboratory Standard Institute 2023. Hasil penelitian menunjukkan bahwa 11 isolat E. coli mengalami resistansi terhadap ampisilin (33,33%), tetrasiklin (23,81%), sulfametoksazol-trimethoprim (14,29%), sefotaksim (19,05%), streptomisin (4,76%), dan terendah adalah antibiotik kloramfenikol (9,52%). Empat isolat E. coli bersifat multi-drug resistance dengan sebagian besar pola ampisilin-tetrasiklin- sulfametoksazol trimetoprim-sefotaksim. Keberadaan E. coli yang resistan antibiotik dapat menimbulkan ancaman kesehatan masyarakat., Food especially those sold on the roadside, is susceptible to contamination by Escherichia coli (E. coli) one of them is chicken soto. Pathogenic Escherichia coli is often resistant to antibiotics which can cause danger to humans because infections that were previously easily treated with antibiotics are now less effective. The purpose of this study was to identify antibiotic resistance from E. coli isolated from shredded chicken in chicken soto sold around IPB University, Dramaga, Bogor. The samples used were 21 isolates that had been tested positive for the presence of E. coli. The antibiotic resistance was examined using the Kirby-Bauer disk diffusion method and referred to the Clinical Laboratory Standard Institute 2023. The results indicated that 11 E. coli isolates were resistant to ampicillin (33.33%), tetracycline (23.81%), sulfamethoxazole-trimethoprim (14.29%), cefotaxime (19.05%), streptomycin (4.76%), and the lowest was the antibiotic chloramphenicol (9.52%). Four E. coli isolates were multi-drug resistant, predominantly showing the pattern of ampicillin-tetracycline-sulfamethoxazole trimethoprim-cefotaxime. The ocurance of antibiotic resistance E. coli can pose a public health threat.
Keyword: antibiotik, daging ayam, Escherichia coli, resistansi

Judul: Resistance of Escherichia coli Isolates in  Shredded Chicken Meat of Chicken Porridge Sold Around the Campus of IPB  University
Abstrak: Bubur ayam merupakan salah satu pangan asal hewan yang berpotensi terkontaminasi bakteri Escherichia coli (E. coli) resistan terhadap antibiotik. Escherichia coli yang resistan terhadap antibiotik menjadi masalah kesehatan di dunia karena menyebabkan pengobatan menjadi tidak efektif. Tujuan penelitian ini yaitu mendapatkan gambaran tingkat resistansi antibiotik dari bakteri E. coli yang diisolasi dari daging ayam suwir bubur ayam yang dijual di lingkar Kampus IPB, Dramaga, Bogor. Sebanyak tujuh isolat yang teridentifikasi E. coli dijadikan sampel dalam penelitian ini. Pengujian resistansi menggunakan metode Kirby-Bauer disk diffusion dan mengacu pada Clinical Laboratory Standard Institute 2023. Resistansi E. coli dari daging ayam suwir bubur ayam menunjukkan terhadap tetrasiklin dengan persentase (57%; 4/7) dan diikuti ampisilin dan sulfametoksazol trimetoprim sebesar (14%; 1/7). Isolat E. coli juga menunjukkan hasil intermediet pada ampisilin sebesar (57%; 4/7). Semua isolat bakteri E. coli masih sensitif terhadap streptomisin (100%), sefotaksim (100%), dan kloramfenikol (100%), sedangkan isolat masih sensitif terhadap sulfametaksazol-trimetoprim (86%), tetrasiklin (43%), dan ampisilin (29%). Isolat E. coli bersifat multi-drug resistance dengan pola ampisilin-tetrasiklin-sulfametoksazol trimetoprim.
Keyword: antibiotik, daging ayam, Escherichia coli, resistansi

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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