Detection of Vt1 and Vt2 Genes in E. Coli O157:H7 Isolated from Soft Cheese in Basrah, Iraq Using Duplex Pcr

During the period extended from November 2010 to March 2011, One hundred fifty soft cheese samples were collected from three different markets in Basrah city.  All samples were cultured in selective media to detect the presence of non-sorbitol fermenting colonies (NSF). 94 (62.66%) isolates were found non-sorbitol fermenting E. coli. Latex agglutination test was used to detect serotype O157:H7 in non- sorbitol fermenting isolates for 15 (33.34%) isolates. Duplex PCR were done to all E. coli O157:H7 isolates and the result showed 5/150 (3.34%) were positive to this test. All the E. coli O157:H7 isolates were positive to vt1 gene which was observed in 100% of isolates but none of the isolates were detected to having a vt2 gene

Detection Of Intracellular Adhesion Gene (Icaa And Icad) And Biofilm Formation Staphylococcus Aureus Isolates From Mastitis Milk Of Cow

In the present study, a total of 75 mastitis milk samples were collected from cow and were analyzed for the presence of S.aureus. The obtained results indicate that this bacterium observed in 26.66%. The study of antibiotic susceptibility test to 9 different antibiotics showed that S. aureus was 100% resistant to penicillin and 100% sensitive to Vancomycin, Gentamycin , Clarithromycin and Chloramphenicol . Whereas for cefoxitin (alternative to methicillin) resistance was 50%.There were a variable resistance percentage for the rest of antibiotics: Tetracycline (30%), Ciprofloxacin and Clindamycin (22%). The biofilm-forming ability of S. aureus was evaluated via microtiter plates and the result revealed that, all the studied isolates were either moderate biofilm producer or weak biofilm producer while the non-biofilm producer and strong biofilm producer were not detected among the tested isolate. PCR analysis was applied to DNA extracted from S.aureus isolates from milk samples .The results of PCR assay revealed that all S.aureus isolates gave positive results for both icaA and icaD genes (100%) with Product size 151 and 211 bp, respectively.Results of this study indicate that biofilm producing S.aureus have a major role player on the occurrence of bovine mastitis in addition, there were high prevalence of MRSA isolates (50%) in mastitis milk at the study area

Detection of Verotoxigenic E. coli O157:H7 in Raw Milk Using Duplex PCR in Basra City- Iraq

One hundred fifty milk samples were collected from three different markets in Basra city during a period extend of from November 2010 to March 2011. All samples were cultured in selective media to detect the presence of non-sorbitol fermenting colonies (NSF) 86 (57.34%) isolates were found non-sorbitol fermenting E. coli. Latex agglutination test was used to detect serotype O157:H7 in non- sorbitol fermenting isolates for 13 (27.08%) isolates. Multiplex PCR were done to all E. coli O157:H7 isolates and the result showed 7/150 (4.67%) from raw milk were positive to this test. All the multiplex PCR positive E. coli O157:H7 isolates were positive to VT1 gene which was observed in 100% except one isolates which was positive to (VT1and VT2) genes at 14.28% from 7 isolates of raw milk samples

Cloning and Expression of Synthetic Plantaricin F Gene

Antimicrobial activity of certain species of Lactobacillus bacteria were known to produce a certain type of bacteriocin called Plantaricin (Pln). In this study, the PlnF (plnF) gene (666 bp) encoding plantaricin was synthetically constructed based on a sequence of predefined and valuable amino acid compositions and subcloned into pET-28 (+) expression vector. Thereafter transformation of recombinant vector into BL21 (DE3) competent E. coli was achieved and to verify the result of cloning, the PCR colony technique was conducted. The expression of the inserted gene was analyzed by the SDS-polyacrylamide gel electrophoresis method, which detected a band of approximately 30 KD molecular weight for interested protein as a natural bioactive bacteriocin

Реалізація протоколів довільного доступу SMA/CA ALOHA для пакетизації безпровідних мереж з модельним проектуванням

Because of the reliability of deployment, cost efficiency, and flexibility of ad-hoc wireless local networks (WLAN). These wireless networks have grown to be the everywhere connection solution in residential and public access networking protocols. It is important to know which strategy performs better with the least amount of delay. The Multiple Access Control protocols (MAC) that are relied on ALOHA, and Carrier Sense Multiple Access with collision avoidance (CSMA/CA) as random access techniques, have substantially aided the rapid growth of such wireless access networks. This work provides a model-based design approach for modeling CSMA/CA and ALOHA random-access protocols for packetizing wireless networks. We analyze the TX and Back-off waveforms of the PHY/MAC transceiver of three radio nodes under CSMA/CA and ALOHA operation modes and compare the obtained results of the PHY/MAC Transceiver for the network nodes according to these modes. Every node is within a range such that the communication between each couple of nodes can be interfered with and received data from the third node. The MAC layer and the logical link control function composed the data link layer. Since the same radio band is used for TX and RX, the MAC function employed here is CSMA/CA and ALOHA, which had also called a random back-off. The MAC layer sends a control signal to the TX block to transmit either a data frame or an acknowledgment frame. The frame contents are loaded in the look-up tables. The contents can be changed in the workspace. The output of this block is a complex baseband IQ signal. The obtained results show the effectiveness of CSMA/CA over ALOHA modes when comparing the corresponding Back-off waveforms and when calculating the throughput values of the three network nodesЧерез надійність розгортання, рентабельності та гнучкості спеціальних бездротових локальних мереж (WLAN). Ці бездротові мережі перетворилися на універсальне рішення для підключення до житлових та загальнодоступних мережевих протоколів. Важливо знати, яка стратегія працює краще із найменшою затримкою. Протоколи управління множинним доступом (MAC), засновані на ALOHA, і множинний доступ з контролем несучої та запобіганням колізій (CSMA/CA) як методи довільного доступу істотно сприяли швидкому зростанню таких мереж бездротового доступу. У цій роботі представлений на моделях підхід до моделювання протоколів довільного доступу CSMA/CA і ALOHA для пакетування бездротових мереж. Ми аналізуємо форми сигналів TX та Back-off приймачів PHY/MAC трьох радіовузлів у режимах роботи CSMA/CA та ALOHA та порівнюємо отримані результати приймачів PHY/MAC для мережевих вузлів відповідно до цих режимів. Кожен вузол знаходиться в межах діапазону, тому зв'язок між кожною парою вузлів може бути порушена і отримані дані від третього вузла. Рівень MAC та функція управління логічним каналом становлять рівень каналу передачі даних. Оскільки для TX і RX використовується той самий діапазон радіочастот, використовується тут функція MAC — це CSMA/CA і ALOHA, які викликали випадкову відстрочку. Рівень MAC відправляє керуючий сигнал блок TX для передачі або кадру даних, або кадру підтвердження. Вміст кадру завантажується у довідкові таблиці. Вміст можна змінити у робочій області. Вихід цього блоку є комплексним сигналом IQ основної смуги частот. Отримані результати показують ефективність CSMA/CA порівняно з режимами ALOHA у порівнянні відповідних сигналів Back-off і розрахунку значень пропускної спроможності трьох вузлів мереж