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: Antibiotic Resistance of Escherichia coli Isolated from Raw Milk in Kebon Pedes, Bogor
Abstrak: Resistansi antibiotik muncul dan menyebar secara global, mengancam kemampuan untuk mengobati penyakit menular dan menjadi ancaman kesehatan global. Penelitian ini bertujuan untuk mengetahui terjadinya resistansi antibiotik pada Escherichia coli (E. coli) yang diisolasi dari susu mentah di Kebon Pedes, Bogor. Resistansi antibiotik E. coli dalam susu dilakukan dengan mengevaluasi 23 sampel susu mentah curah dari peternakan sapi perah di Kebon Pedes, Bogor. Isolasi dan identifikasi E. coli merujuk pada SNI 2897: 2008 tentang Pedoman Analisis Laboratorium pada Pemeriksaan Kontaminasi Mikroba pada Daging, Telur, dan Susu dalam yang dikeluarkan oleh Badan Standardisasi Nasional Indonesia. Resistansi terhadap enam antibiotic, yaitu amoksilin, streptomisin, siprofloksasin, tetrasiklin, kolistin, dan penisilin G, diuji menggunakan metode difusi cakram Kirby-Bauer berdasarkan standar Clinical Laboratory Standards Institute (CLSI) pada tahun 2018. Hasilnya menunjukkan bahwa 62 dari 207 isolat (29.95%) isolat ditemukan positif E. coli. E. coli menunjukkan resistansi terhadap antibiotik, yaitu penisilin G (95.2%), streptomisin (84.3%), kolistin (76.9%), amoksisilin (74.2%), dan tetrasiklin (62.5%). 77.42% isolat E. coli positif resistan terhadap lebih dari tiga kelas antibiotik, yang dikenal sebagai multi-drug resistant (MDR), dengan sebagian besar pola AML-S-TE-CT-P (amoksisilin, streptomisin, tetrasiklin, kolistin, dan penisilin G). Kehadiran E. coli yang resistan terhadap antibiotik dalam susu mentah dapat menyebabkan masalah serius pada kesehatan manusia.
Keyword: Escherichia coli, multi-drug resistant, resistansi antibiotik, susu, Escherichia coli, multi-drug resistant, resistansi antibiotik, susu

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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