Judul: Isolation of Antibiotic-Resistant Escherichia coli from Milker Hands and Teats Surface of Dairy Cattle in Pondok Ranggon Farms
Abstrak: Escherichia coli yang resistan terhadap antibiotik menjadi masalah kesehatan global karena menyebabkan pengobatan menjadi tidak efektif. Tujuan dari penelitian ini adalah mengisolasi E. coli dari tangan pemerah dan puting sapi perah di peternakan sapi perah Pondok Ranggon, Jakarta Timur serta sifat resistansinya terhadap antibiotik. Sebanyak 21 swab tangan pemerah dan 48 sampel swab puting sapi perah dari 12 peternakan dijadikan sampel dalam penelitian ini. Identifikasi E. coli menggunakan metode most probable number (MPN) menurut Bacteriological Analytical Manual tentang Food and Drug Admnistration dan uji resistansi antibiotik mengacu pada Clinical Laboratory Standard Institute 2018 metode Kirby-Bauer disk diffusion. Isolat E. coli diperoleh dari 3 sampel swab tangan pemerah (3/21; 14,3%) dan 4 sampel swab permukaan puting sapi (4/48; 8,3%). Isolat E. coli dari tangan pemerah resistan terhadap azitromisin, streptomisin, sefotaksim, sefpodoksim, seftazidim, dan trimetopimsulfametoksasol sebesar 33,3% (1/3). Resistansi E. coli dari swab puting sapi tertinggi terhadap sefotaksim, sefpodoksim, dan seftazidim dengan persentase 75% (3/4), diikuti ampisilin (50%; 2/4), amoksisilin-asam klavulanat dan trimetoprimsulfametoksasol sebesar 25% (1/4). Isolat E. coli dari tangan pemerah dan puting sapi perah sensitif terhadap gentamisin, azitromisin, siprofloksasin, kloramfenikol, doksisiklin, oksitetrasiklin, dan tetrasiklin. Isolat E. coli bersifat multi-drug resistance dengan pola sefotaksim-sefpodoksim-seftazidim., Escherichia coli plays the role in the occurance of mastitis in dairy cows. The antibiotic resistant E. coli causes the global health problem because of the ineffective treatment of infectious diseases. The aim of the study was to identify E. coli on milker hands and teat surfaces and the antibiotic resistance in dairy farms in Pondok Ranggon, East Jakarta. This study used 21 samples of milker hands swabs and 48 samples of teat surface swabs from 12 dairy farms. Identification of E. coli using most probable number (MPN) method based on Bacteriological Analytical Manual concerning Food and Drug Admnistration. E. coli was isolated from 3 samples of milker hands (3/21; 14.3%) and 4 samples of teats (4/48; 8,3%). E. coli isolates from milker hands were resistant to azithromycin, streptomycin, cefotaxime, cefpodoxime, ceftazidime, and trimetroprim-sulfametoxazole with the same percentage (33,3%; 1/3). On the teat surfaces, the highest percentage of antibiotic resistance in cefotaxime, cefpodoxime, ceftazidime (75%: 3/4), and ampicilin (50%; 2/4), and the lowest percentage in amoxicillin-clavulanate and trimetroprim-sulfametoxazole (25%; 1/4). All of isolates still sensitive to gentamycin, azithromycin, ciprofloxacin, chloramphenicol, doxycycline, oxytetracycline, and tetracycline. E. coli isolates have multi-drug resistant with cefotaxime-cefpodoxime-ceftazidime pattern.
Keyword: antibiotic resistance, Escherichia coli, swabs

Judul: Antimicrobial Resistance of Escherichia coli and Staphylococcus aureus in Raw Milk from Peternakan Sapi Perah Pondok Ranggon
Abstrak: Penggunaan antibiotik berlebih dapat menyebabkan resistansi antibiotik pada ternak yang dapat disebarkan ke manusia dan lingkungan. Penelitian ini bertujuan mengisolasi bakteri Escherichia coli dan Staphylococcus aureus dari susu segar dan mengetahui sifat resistansinya terhadap antibiotik. Pengujian diawali dengan isolasi dan identifikasi bakteri berdasarkan SNI 2897:2008 tentang Metode Pengujian Cemaran Mikroba dalam Daging, Telur dan Susu, serta Hasil Olahannya dan dilanjutkan dengan pengujian resistansi antibiotik menggunakan metode Kirby-Baurer. Antibiotik yang digunakan yaitu golongan β-laktam, aminoglikosida, makrolida, fluorokuinolon, antagonis asam folat, kloramfenikol, tetrasiklin dan cephems. Dari 36 sampel susu segar didapatkan 16 sampel (25 isolat) positif tercemar E. coli dan 13 sampel (13 isolat) positif S. aureus. Sebanyak 24/25 isolat E. coli resistan terhadap 15 jenis antibiotik dan 13/13 isolat S. aureus resistan terhadap 14 jenis antibiotik. Sebanyak 20/25 isolat E. coli telah mengalami multidrug resistance antibiotic dengan pola yang paling sering ditemui yakni penisilin-aminoglikosida-tetrasiklin-kloramfenikol. Sebanyak 8/13 isolat S. aureus mengalami multidrug resistance dengan pola yang paling sering ditemui yakni penisilin-aminoglikosida-fluorokuinolon. Bakteri yang telah mengalami resistansi antibiotik dapat menjadi ancaman bagi kesehatan ternak, kesehatan lingkungan, keamanan pangan dan kesehatan masyarakat., Overuse of antibiotics can cause antimicrobial resistance in livestock which can spread to humans and the environment. This study aimed to isolate Escherichia coli and Staphylococcus aureus in raw milk and determined their antibacterial susceptibility. Bacterial isolation and identification based on SNI 2897:2008 about Metode Pengujian Cemaran Mikroba dalam Daging, Telur dan Susu, serta Hasil Olahannya were followed up with an antibacterial susceptibility test using the Kirby-Baurer method. The antibiotics used in this study are β-lactam, aminoglycoside, macrolide, fluoroquinolones, folic acid antagonist, chloramphenicol, tetracycline, and cephems Out of 36 raw milk samples, 16 samples (25 isolates) were contaminated with E. coli and 13 samples (13 isolates) were contaminated with S. aureus. As many as 24/25 of E. coli isolates were resistant to 15 types of antibiotics and 13/13 of S. aureus isolates were resistant to 14 types of antibiotics. As many as 20/25 of E. coli isolates were multidrug-resistant with penicillin-aminoglycoside-tetracycline-chloramphenicol as the most common pattern and 8/13 of S. aureus isolates were multidrug-resistant with penicillin-aminoglycoside-fluoroquinolone as the most common pattern. Antimicrobial resistance can be a threat to animal health, environmental health, food safety, and public health.
Keyword: antimicrobial resistance, Escherichia coli, raw milk, Staphylococcus aureus

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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