27 research outputs found
PENGETAHUAN PASIEN HIPERTENSI TERHADAP DIET RENDAH GARAM SEBELUM DAN SESUDAH DIBERIKAN KONSULTASI GIZI DI POLI GIZI RUMAH SAKIT RADEN MATTAHER TAHUN 2017
ABSTRAK
Latar Belakang : Tahun 2013 jumlah penduduk di indonesia yang menderita hipertensi sebanyak 65 juta jiwa dari 252 juta penduduk. Dalam penatalaksanaan non-farmakologi hipertensi, diet rendah garam sangat diperlukan dapat menurunkan sebanyak 2 -8 mgHg tekanan darah. Pengetahuan yang baik tentang diet rendah garam dapat mengontrol tekanan darah bagi pasien hipertensi dengan mengkomsumsi garam tidak lebih dari 2,4 g/hari. Pasien hipertensi sebaiknya diberikan konsultasi gizi untuk meningkatkan pengetahuan tentang diet rendah garam. Dari hasil data rekam medik RSUD raden Mattaher pada januari-maret 2016 jumlah kasus baru pasien hipertensi 60 pasien dengan jumlah kunjungan 586 pasien dan tidak semua pasien mendapatkan konsultasi gizi. Tujuan penelitian ini mengetahui perbedaan ni lai pengetahuan pasien hipertensi sebelum dan sesudah diberikan konsultasi gizi.
Metode : Desain penelitian ini adalah Pre- ekperimen dengan one grup pretest posttest design. Teknik pengambilan sampel menggunakan purposive sampling. Sampel adalah 20 pasien hipertensi yang melakukan konsultasi gizi di RSUD Raden Mattaher. Sebelum dan sesudah konsultasi gizi pasien diminta menjawab kuesioner yang terdiri dari 12 pertanyaan. konsultasi diet rendah garam diberikan oleh ahli gizi sesuai dengan materi yang telah ditetapkan. Analisis data menggunakan uji t.
Hasil : Perbedaan rata-rata skor sebelum diberikan konsultasi gizi adalah 67,90 dan rata -rata skor sesudah diberikan konsultasi gizi adalah 87,90 rata -rata skor pengetahuan sebelum dan sesudah diberikan konsultasi gizi adalah 20,00 dengan nilai signifikansi 0,000<0,05.Dari hasil analisis data dengan uji t didapatkan ada perbedaan pengetahuan sesudah diberikan konsultasi gizi
Kesimpulan : Ada peningkatan pengetahuan setelah diberikan konsultasi gizi.
Kata Kunci : Hipertensi, Diet Rendah Garam, Konsultasi Gizi
ABSTRACT
Background: In 2013 total population in Indonesia suffering from hypertension as much as 65 million people from 252 million population. In the non-pharmacological management of hypertension, a low-salt diet can reduce as much as 2-8 mgHg blood pressure. A good knowledge of low-salt diet can control blood pressure for hypertensive patients by consuming no more 2.4 g/ day. Hypertensive patients should be given nutritional assistance to improve knowledge about low-salt diet. From the results of medical record at Regional Public Hospital Raden Mattaher in january to March 2016 the number of new cases of hypertensive patients 60 patients with the number of visits 586 patients but not all patients get nutrition consultation. The purpose of this study was to know the difference in the value of knowledge of hypertensive patients before and after being given nutritional consultation.
Methods: This Pre- experiment study used one group pretest posttest design. Sampling technique using non probability sampling that purposive sampling. With 20 hypertensive patients, who conducted nutritional counseling at Regional public hospital Raden Mattaher. Before and after the nutrition consultation the patient was asked to answer a questionnaire used consist 12 questions. Low-salt diet consultancy is given by nutritionists in accordance with the material that has been set. Data analysis with t test.
Result: The mean difference score before given a nutritional consultation was 67.90 and the mean score after given a nutritional consultation was 87.90. The mean difference between the pre and post nutritional score was 20.00 with a significance value of 0.000 <0.05. From the results of data analysis with t test there is a difference of knowledge after given a nutritional consultation.
Conclusion: There is improvement knowledge after being given a nutrisional consultation.
Keywords: Hypertension, Low Salt Diet, Nutrition Consultatio
Diagnosis Molekuler Human Papilloma Virus (HPV) Penyebab Kanker Serviks
Cervical cancer is still the one of major public health problem in the world whether an effective screening programs using the Papanicolaou test to detect precancerous lesions has reduced the number of cases of cervical cancer in the developed countries but not in developing countries. The sensitivity and specificity of the Pap smear depends on observer's skills to recognize and classify variations of abnormal cells. Human Papilloma Virus (HPV) caused cervical cancer has been proved, In some study have found HPV DNA in 99.7 % of all cervical carcinomas. HPV has been found to be more than 100 genotypes , which are divided into high-risk HPV and low-risk HPV The development of early diagnosis for the detection of HPV infection still has been a problem, where the cytology and colposcopy to identify lesions at an advanced stage, therefore the molecular engineering approach seems to be more successful in early diagnosing cervical cancer. This technique of molecular HPV DNA sequences are Southern Blot Hybridization, Hybrid Capture II Assay, Polymerase Chain Reaction, and PCR - Reverse Line Blot. The Accuracy of molecular diagnostic techniques is required to provide further information for patient how the management and maintenance of cervical cancer
EFEKTIVITAS MENCUCI TANGAN DENGAN SABUN CUCI TANGAN CAIR BERBAHAN AKTIF TRICLOCARBAN PADA MAHASISWA FAKULTAS KEDOKTERAN UNIVERSITAS JAMBI ANGKATAN 2015
Abstract
Background: Hand hygiene is essential to prevent various infectious diseases caused by bactery of hands which can contaminate hands in a short time during daily activities. Indonesian people who wash their hands with soap only 12%. One of the methods hand washing in removing dirt and germs on the hands is Seven-step hand washing. Many types of soaps are used by people to wash their hands and Triclocarban is one of the active ingredient of hand washing soap. The aim of this study was to determine the effectiveness of seven-step of hand-washing with liquid Triclocarban soap in hand hygiene.Method : This study was an analytic study by using one group pretest-posttest experiment. The study took place in biomedic laboratorium Faculty of Medicine and Health Sciences University Jambi from January to March 2016. The samples were 36 swab cottons stick from sidelines right fingers students before and after handwash then analyzed with statistic.
Result : The average number of bacterial colonies before and after hand wash were 28,41 and 7,12 CFU/Cm2. The study was considered significant because the results of Wilcoxon test show p<0.15 was 0,000. The bactery found mostly was cocci gram-positive and the least was bacilli gram-negative.
Conclusion : Seven-steps hand washing with liquid triclocarban soap is effective in maintaining the cleanliness of hands.
Keywords : Hand wash with soap, Seven steps hand washing, Triclocarban
Abstrak
Latar Belakang : Kebersihan tangan penting untuk mencegah penyakit infeksi karena mikroba mengkontaminasi tangan dalam waktu yang singkat dalam aktivitas sehari-hari. Rata-rata hanya 12% masyarakat Indonesia yang mencuci tangan pakai sabun. Metode cuci tangan tujuh langkah adalah metode cuci tangan paling lengkap dalam menghilangkan kotoran dan kuman yang ada di tangan. Banyak jenis sabun yang digunakan untuk mencuci tangan, salah satunya sabun cuci tangan berbahan aktif Triclocarban. Tujuan penelitian ini adalah untuk mengetahui efektivitas mencuci tangan tujuh langkah dengan sabun cuci tangan cair Triclocarban dalam menjaga kebersihan tangan.
Metode : Jenis penelitian ini adalah penelitian analitik one group pretest-posttest eksperimen. Lokasi di laboratorium Biomedik FKIK Universias Jambi dari Januari sampai Maret 2016. Sampel penelitian ini adalah usapan kuman dengan kapas lidi di sela-sela jari tangan kanan mahasiswa sebelum dan sesudah cuci tangan sebanyak 36 orang yang kemudian dianalisis dengan menggunakan uji wilcoxon.
Hasil : Jumlah koloni bakteri rata-rata sebelum dan sesudah cuci tangan adalah 28.41 dan 7.12 CFU/Cm2. Penelitian ini dianggap bermakna karena pada hasil analisis uji Wilcoxon didapatkan nilai p < 0,15 yakni 0,000. Bakteri yang paling banyak didapatkan adalah kokus gram positif dan paling sedikit batang gram negatif.
Kesimpulan : Mencuci tangan tujuh langkah dengan sabun cuci tangan cair Triclocarban efektif dalam menjaga kebersihan tangan.
Kata Kunci : CTPS, Cuci tangan tujuh langkah, Triclocarba
INFLAMASI BOWEL DISEASE
ABSTRACT
Inflammatory Bowel Disease (IBD) is one of public health problems because it will affect patient education, work ability and related with quality of life. IBD is a chronic recurrent inflammation of the small intestine and colon with unknown etiology, with symptoms mild to severe abdominal pain and diarrhea. IBD is divided into 2 types: one is Crohn's disease (CD) which often occurs in the ileum (can extend to the entire gastrointestinal tract) with symptoms of abdominal pain, diarrhea, vomiting and weight loss, and two is Ulcerative colitis (UC) which is characterized by progressive inflammation. in the gastrointestinal tract and colonic mucosa. The etiology of IBD is suspected result of a complex interaction between genetics, role of the gut microbiota, immune system, and specific environmental factors. The pathogenesis of IBD is not clearly known, there is a thought that IBD is caused by a complex role between the gut microbiota, dysregulation of the immune system, role of genetics and environmental factors. Diagnosis is based on history taking, physical examination, supporting examinations such as blood tests, stool cultures, radiological examinations, endoscopic examinations and histopathology. The principle of IBD therapy is treating active IBD inflammation quickly until remission, prevent recurrent inflammation by maintaining remission as long as possible, and treat/prevent complications. The management includes pharmacotherapy, nutrition, surgery and psychotherapy.
Keyword: Inflammatory Bowel Disease (IBD), Ulcerative colitis (UC)
ABSTRAK
Inflamatory Bowel Disease (IBD) merupakan masalah kesehatan masyarakat yang penting karena akan mempengaruhi pendidikan pasien, kemampuan bekerja dan berhubungan dengan kualitas hidupnya. IBD adalah peradangan kronik berulang pada usus halus dan kolon yang belum diketahui penyebabnya dengan gejala sakit perut yang berat dan diare. IBD terbagi atas 2 jenis, yaitu: Crohn’s disease (CD) yang sering terjadi ileum (dapat meluas ke seluruh dinidng saluran cerna) dengan gejala sakit perut, diare, muntah dan penurunan berat badan, dan Ulcerative colitis (UC) yang ditandai dengan peradangan progresif pada sistem saluran cerna dan mukosa kolon. Etiologi IBD secara pasti belum diketahui, diduga IBD merupakan hasil dari interaksi kompleks antara genetik, peran mikrobiota usus, sistem imunitas, faktor lingkungan yang spesifik. Patogenesis IBD secara jelas belum diketahui, adanya pemikiran bahwa IBD disebabkan oleh peran kompleks antara mikrobiota usus, disregulasi sistem imun, peran genetik dan faktor lingkungan. Penegakkan diagnosis berdasarkan anamnesis, pemeriksaan fisik, pemeriksaan penunjang seperti pemeriksaan darah, kultur tinja, pemeriksaan radiologi, pemeriksaan endoskopi dan histopatologi. Prinsip terapi IBD adalah mengobati peradangan aktif IBD dengan cepat sehingga tercapai remisi, mencegah peradangan berulang dengan mempertahankan remisi selama mungkin, dan mengobati/mencegah komplikasi. Manajemen IBD meliputi farmakoterapi, nutrisi, operasi dan psikoterapi.
Keyword: Inflamatory Bowel Disease (IBD), Ulcerative colitis (UC
PENGARUH PEMBERIAN EKSTRAK ETHANOL BIJI BUAH PINANG (ARECA CATECHU L.) TERHADAP PERTUMBUHAN STAPHYLOCOCUS AUREUS SECARA IN VITRO
ABSTRACT
Background: Infectious disease is known as a global concern because of the irrational, excessive and long term use of antibiotics especially in Staphylococcus aureus infection. The unecessarily use of antibiotics can creat a resistance issue such as MSSA, MRSA, VISA and VRSA. So as a new alternative that is being developed in medicine, herbal plants are used. Areca nut (Areca catechu. L) is a herbal plant that is found in Indonesia, especially in Province of Jambi, betel nut is one of the best in the world. The aim of this study are to investigate phytochemical components and inhibition effect Staphylococcus aureus ATCC 25923 using dry ethanol extract of betel nuts at concentrations 20%, 30%, 40% and 50% in vitro.
Method: Antibacterial sensitivity tests against Staphylococcus aureus ATCC 25923 were performed using dry ethanol extract of betel nuts (Areca catechu. L) with various concentrations on each group. Group I is treated nut with a concentration of 20%, Group II with a concentration of 30%, Group III with a concentration of 40%, Group IV with a concentration of 50%, the group V as a negative control (distilled) and group VI as a positive control that was given amoxicillin clavulanate 30μg. Then the inhibitory effects of these treatments are measeure and classified by the Davis and Stout classification in 1971. The data analysis began with Saphiro Wilk test and then with levent test statistic. Because distributed data is not normal, the analysis continued with Kruskal Wallis test and Post Hoc test.
Results: Results of this study showed that the ethanol extract of betel nuts can inhibit the growth of S. aureus, which is a concentration of 20% with a diameter of 13,63mm, concentration of 30% with a diameter of 15mm, concentration of 40% with a diameter of 15,5mm, concentration of 50% with a diameter of 14,7mm compared to the positive control 30μg amoxicillin clavulanate in inhibiting the growth of S. aureus with a diameter of 34,25mm.
Conclusion: The ethanol extract of betel nuts can inhibit the growth of Staphylococcus aureus in vitro. Areca seed extract with concentration of 40% is the optimum concentration to inhibit the growth of Staphylococcus aureus.
Keywords: Staphylococcus aureus, Areca catechu. L, Sensitivity Test.
ABSTRAK
Latar Belakang : Penyakit infeksi merupakan masalah yang menjadi perhatian global, oleh karena penggunaan antibiotik yang irasional, berlebihan dan dalam jangka waktu yang lama, terurama infeksi yang disebabkan oleh Staphylococcus aureus. Hal ini dapat menimbulkan masalah baru resistensi antibiotik seperti MSSA, MRSA, VISA dan VRSA. Maka sebagai alternatif baru yang sedang dikembangkan dalam pengobatan yaitu dengan menggunakan tanaman herbal. Pinang (Areca catechu. L) merupakan tanaman herbal yang banyak ditemukan di Indonesia terutama Propinsi Jambi, pinang ini merupakan salah satu pinang terbaik di dunia. Tujuan dari penelitian ini adalah untuk mengetahui komponen fitokimia dan daya hambat ekstrak ethanol biji buah pinang terhadap pertumbuhan Staphylococcus aureus ATCC 25923 secara in vitro pada konsentrasi 20%, 30%, 40% dan 50%.
Metode : Ekstrak ethanol biji buah pinang kering (Areca catechu. L) dilakukan uji sensitifitas antibakteri terhadap Staphylococcus aureus ATCC 25923 dengan berbagai konsentrasi pada masing – masing kelompok. Kelompok I yaitu perlakuan pinang dengan konsentrasi 20%, kelompok II dengan konsentrasi 30%, kelompok III dengan konsentrasi 40%, kelompok IV dengan konsentrasi 50%, kelompok V sebagai kontrol negatif (Aquades) dan kelompok VI sebagai kontrol positif dengan diberikan Amoksisilin Klavulanat 30µg. Kemudian diukur efek inhibisi dari perlakuan tersebut dan digolongkan berdasarkan penggolongan Davis and Stout 1971. Analisis data diawali dengan uji Saphiro-Wilk dan dilanjutkan dengan uji Levene, oleh karena data terdistribusi tidak normal maka dilakukan uji Kruskal Wallis dan uji Post Hoc.
Hasil : Hasi penelitian menunjukkan bahwa ekstrak ethanol biji buah pinang dapat menghambat pertumbuhan S. aureus, yaitu konsentrasi 20% dengan diameter 13,63mm, konsentrasi 30% dengan diameter 15mm, konsentrasi 40% dengan diameter 15,5mm, konsentrasi 50% dengan diameter 14,7mm. Terdapat pengaruh Areca catechu. L dalam menghambat pertumbuhan Staphylococcus aureus ATCC 25923.
Kesimpulan : Ekstrak ethanol biji buah pinang dapat menghambat pertumbuhan Staphylococcus aureus secara in vitro. Konsentrasi ekstrak biji buah pinang 40% merupakan konsentrasi optimum dalam menghambat pertumbuhan Staphylococcus aureus.
Kata Kunci : Staphylococcus aureus, Areca catechu. L, Uji Sensitifitas
Faktor-Faktor Risiko Kejadian Tuberkulosis Paru Kambuh Di Puskesmas Kota Jambi Tahun 2020-2022
ABSTRAK
Latar Belakang: Tuberkulosis (TB) paru kambuh merupakan salah satu kendala untuk tercapainya target End TB strategy tahun 2030 sehingga perlu penelitian mengenai ini. Tujuan penelitian ini yaitu untuk mengetahui gambaran faktor risiko terjadinya TB paru kambuh di Puskesmas Kota Jambi tahun 2020-2022
Metode: Penelitian ini menggunakan desain deskriptif retrospektif. Sampel dalam penelitian ini berjumlah 22 orang yang diambil dengan menggunakan teknik total sampling. Analisis data yang digunakan yaitu analisis univariat.
Hasil: Hasil penelitian faktor risiko kejadian tuberkulosis paru kambuh di Puskesmas kota Jambi tahun 2020-2022 didapatkan sebagian besar penderita yaitu laki-laki (81,8%), usia >34 tahun (77,3%), status sosial ekonomi rendah (81,8%), tingkat pendidikan terakhir SMA (59,1%) dan ada riwayat kebiasaan merokok (55,5%), status gizi normal (59,1%), kepadatan hunian kamar memenuhi syarat (86,4%), riwayat berobat teratur (77,3%), tidak ada penyakit penyerta (68,2%), tidak ada riwayat kontak erat (68,2%), pengetahuan baik (59,1%), sikap yang baik (77,3%) dan dukungan keluarga yang baik (68,2%).
Kata Kunci: Faktor risiko, tuberkulosis paru, kambu
Gambaran Obat Tradisional yang Digunakan Penderita Malaria di Wilayah Puskesmas Simpang IV Sipin Kota Jambi 2014
ABSTRACT Background: Traditional medicine is the ingredients derived from plants, animals, minerals or mixtures of these materials. Malaria is an infectious disease caused by Plasmodium parasites that invade erythrocytes and characterized by the discovery of asexual blood forms. At Jambi province, the morbidity due to malaria is still quite high. There are nine districts and two municipalities which is a malaria endemic area. The proportion use of traditional medicine for malaria is still unknown include Jambi province. The number of people and the efficacy of using a traditional medicine remains unknown. This research designed in order to describe the use of traditional medicine in patients with malaria. Methods: The type of this research is descriptive quantitative research. The study was conducted at the Puskesmas Simpang IV Sipin Jambi. The entire study of population malaria patients that visiting Puskesmas Simpang IV Sipin and home visit patients who had suffered from malaria in the month of November 2013-February 2014. The number of samples in this study is 70 respondents. Data were analyzed by univariate analysis. Result: From the results, users of traditional medicine as much as 34.5%, traditional types of drugs most widely used is the use of sambiloto (27.1%), the most reason way the patients take traditional medicine because the side effects are relatively small (35.7%), the most way to mix the ingredients is by blend the ingredients together boiled it whit water, after that patients drunk the potions (80%), the most way to find the ingredients is looking around the house (80%), the most duration of using traditional medicine expressed by respondents is for 3 days (41.4%), and 95.7% expressed the feeling that the traditional treatment is efficacious. Conclusion: The results stated that the description of the use of traditional medicine in Puskesmas Simpang IV Sipin is 34.5%. Â Keywords: Traditional medicine, malari
Dextran Sulfate Sodium Effectiveness As Inflammatory Bowel Disease Inducer In BALB/c Mice
ABSTRACT
Background: Inflamatory Bowel Disease (IBD) in animal model could be induced by chemical agents such as dextran sulfate sodium (DSS), Â trinitrobenzene sulfanic acid and oxazolone. The inflammation induced by DSS gave many clinical symptoms and immnulogic reactions like in human. In the recent study, the disease activity index has been assessed on the BALB/c mice that induced by DSS 2% and 3%, the result was no significant result. Therefore, DAI score was not necessarily describe the intestinal tissue real condition, so the researcher want to continue assessing DSS influence to the microscopic features of BALB/c mice intestine and colon.
Methods: Nine male BALB/c mice 6-8 weeks, weight 25-40 g divided in 3 groups. Group I as control, while group II and III induced by  2 cycles of 2% DSS for 5 days followed by drinking water for 10 days and 3 cycles of 3% DSS for 7 days followed by drinking water for 7 days. Assesment of DSS effectiveness by microscopic examination of intestine and colon to observe inflammatory features.
Results: . The microscopic features of group II and group III mice intestine and colon has no inflammatory features as control group. Oral admission DSS 2% and DSS 3% did not establish microscopic changes in BALB/c mice intestine and colon, so it was not effective as mice IBD inducer.
Uji Kualitas Air Minum Isi Ulang di Kota Jambi
Abstract
Background: Clean water for drinking is rare where the source has been contaminated with various kinds of waste, such as disposal of organic waste, household and toxic waste from the industry, so that ground water is also not safe to become a drinking water because it has been contaminated from the septic tank or surface water. Bottled drinking water is a choice for clean drinking water but the price of bottled drinking water is high enough and makes consumers look for the cheaper and the new alternatives such as refill drinking water. Depo drinking water refills continue to increase in line with the public needs of drinking water quality and safe for consumption, though cheaper, not all depo of drinking water refills are guaranteed product security. This study is to know quality test of the drinking water refill in Jambi City
Method: This descriptive study with experimental research laboratory design was conducted in Jambi city with 62 samples from 11 sub-districts in Jambi city and conducted in Biomedical Laboratory of FKIK UNJA. Water samples were conducted by 3 stages of examination, ie the prediction test, the strengthening test and the complementary test with 5 tubes. This research was conducted in May - October 2016. Data study were shown in tables.
Result: The results showed that the drinking water refill category either amounted to 20 depots (32.26%) and drinking water refill the bad category amounted to 42 depots (67.74%). of 42 samples of refill drinking water with positive probability test results, there were 16 samples (38,10%) containing faecal coliform, and 27 samples (64,29%) containing non-faecal coliform.
Conclusion: Drinking Water Refills in Jambi City are not all free from koliform bacteria.
Keywords: Drinking Water Refill, Bacteriological Test, Most Probable Number
Abstrak
Latar Belakang: Air bersih yang layak minum kian langka untuk dijumpai dimana sungai-sungai yang menjadi sumbernya sudah tercemar berbagai macam limbah, seperti buangan sampah organik, rumah tangga hingga limbah beracun dari industri. Air tanah juga sudah tidak aman dijadikan bahan air minum karena telah terkontaminasi rembesan dari tangki septik maupun air permukaan. Air minum dalam kemasan (AMDK) kini menjadi pilihan pemakaian air bersih namun harga AMDK cukup tinggi dan membuat konsumen mencari alternatif baru yang murah seperti air minum isi ulang. Depo air minum isi ulang terus meningkat sejalan dengan keperluan masyarakat terhadap air minum yang bermutu dan aman untuk dikonsumsi, meski lebih murah, tidak semua depo air minum isi ulang ini terjamin keamanan produknya. Penelitian ini bertujuan untuk mengetahui uji Kualitas bakteriologis Air Minum isi Ulang di Kota Jambi.
Metode: Penelitian deskriptif dengan rancangan penelitian eksperimen laboratorium ini dilakukan pada 62 sampel dari 11 kecamatan kota Jambi. Pengujian bateriologis dilakukan menggunakan Most Probable Number yang terdiri dari 3 tahap (uji penduga, uji penguat dan uji pelengkap) dengan seri 5 tabung pada sampel air minum yang dilaksanakan di Laboratorium Biomedik FKIK UNJA. Penelitian ini dilakukan pada bulan Mei – Oktober 2016. Data disajikan dalam bentuk tabel.
Hasil:. Hasil penelitian memperlihatkan bahwa air minum isi ulang kategori baik berjumlah 20 depot (32,26%) dan air minum isi ulang kategori buruk berjumlah 42 depot (67,74%). Dari 42 sampel air minum isi ulang dengan hasil uji penduga positif, terdapat 16 sampel (38,10%) yang mengandung koliform fekal, dan 27 sampel (64,29%) yang mengandung koliform non-fekal.
Kesimpulan: Air Minum isi Ulang yang ada di Kota Jambi tidak semuanya bebas dari koliform fekal.
Kata Kunci: Air Minum Isi Ulang, Uji Bakteriologis, Most Probable Numbe