Evaluation of Membrane Fragments Extracted from Escherichia coli and Pseudomonas aeruginosa on Campylobacter jejuni Growth under Normal Atmosphere

ABSTRACT Study on extraction of membrane fragments from Escherichia coli and Psuedomonas aeruginosa were determined for using to support Campylobacter cultivation under normal atmosphere. Crude membrane fragments were extracted from 45 strains of E. coli and 44 strains of P. aeruginosa. Strains that provided highest efficiency of oxygen reduction were selected to purify membrane fragments by French pressure cell and ultracentrifugation. The purified membrane fragments were characterized and investigated for supporting Campylobacter jejuni growth in Mueller-Hinton broth. The broth supplemented with and without membrane fragments was incubated under normal atmosphere at 37°C or 42°C. Campylobacter growth in the broth containing purified membrane fragments was initially observed within 6 to 12 hours of incubation while the media without supplemented with membrane fragments showed no growth of the bacteria. Therefore, oxygen reducing membrane fragments prepared from the selected strains could support Campylobacter cultivation under normal atmosphere

Allelic loss on chromosome band 18p11.3 occurs early and reveals heterogeneity in breast cancer progression

We examined the stage specificity and heterogeneity of 18p11 alterations in a series of tumors representing 96 microdissected samples. Significant loss of heterozygosity (LOH) (63%) was found, with 56% occurring early in ductal carcinoma in situ. Although most cases indicated LOH was clonally inherited, heterogeneity for 18p LOH occurred in 27% of tumors. When compared with other LOH data, 18p LOH was found in conjunction with allelic deletion on 3p, 9p, 17p and 17q, while 13q, 16q, and 11p were less frequently associated. These analyses suggest chromosome 18p11 alteration is a common and early event in breast disease

Proteome Analyses of Cellular Proteins in Methicillin-Resistant Staphylococcus aureus Treated with Rhodomyrtone, a Novel Antibiotic Candidate

The ethanolic extract from Rhodomyrtus tomentosa leaf exhibited good antibacterial activities against both methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus ATCC 29213. Its minimal inhibitory concentration (MIC) values ranged from 31.25–62.5 µg/ml, and the minimal bactericidal concentration (MBC) was 250 µg/ml. Rhodomyrtone, an acylphloroglucinol derivative, was 62.5–125 times more potent at inhibiting the bacteria than the ethanolic extract, the MIC and MBC values were 0.5 µg/ml and 2 µg/ml, respectively. To provide insights into antibacterial mechanisms involved, the effects of rhodomyrtone on cellular protein expression of MRSA have been investigated using proteomic approaches. Proteome analyses revealed that rhodomyrtone at subinhibitory concentration (0.174 µg/ml) affected the expression of several major functional classes of whole cell proteins in MRSA. The identified proteins involve in cell wall biosynthesis and cell division, protein degradation, stress response and oxidative stress, cell surface antigen and virulence factor, and various metabolic pathways such as amino acid, carbohydrate, energy, lipid, and nucleotide metabolism. Transmission electron micrographs confirmed the effects of rhodomyrtone on morphological and ultrastructural alterations in the treated bacterial cells. Biological processes in cell wall biosynthesis and cell division were interrupted. Prominent changes including alterations in cell wall, abnormal septum formation, cellular disintegration, and cell lysis were observed. Unusual size and shape of staphylococcal cells were obviously noted in the treated MRSA. These pioneer findings on proteomic profiling and phenotypic features of rhodomyrtone-treated MRSA may resolve its antimicrobial mechanisms which could lead to the development of a new effective regimen for the treatment of MRSA infections

แผ่นกรองต้านแบคทีเรียจากผืนเส้นใยนาโนผสมระหว่างพอลิไวนิลลิดีนฟลูออไรด์กับพอลิไวนิลแอลกอฮอล์Antibacterial Membrane from Mixed Poly (vinylidene fluoride) Nanofiber and Poly (vinyl alcohol) Nanofiber

ผืนเส้นใยนาโนพอลิไวนิลลิดีนฟลูออไรด์ (PVDF) ผสมสารต้านแบคทีเรีย สามารถนำไปผลิตแผ่นกรองที่มีคุณสมบัติกรองและยับยั้งการเจริญของแบคทีเรียในน้ำได้ แต่ประสิทธิภาพยังไม่เป็นที่น่าพอใจ เนื่องจาก PVDF มีคุณสมบัติดูดซึมน้ำต่ำจึงมีข้อจำกัดให้สารต้านแบคทีเรียแพร่ออกมา ในงานวิจัยนี้จึงเพิ่มคุณสมบัติการเปียกน้ำโดยผลิตแผ่นกรองที่มีการผสมผสานระหว่างเส้นใยนาโน PVDF กับเส้นใยนาโนพอลิไวนิลแอลกอฮอล์ (PVA) ได้แผ่นกรอง FA ซึ่งมุมสัมผัสของน้ำบนแผ่นกรองลดลงจาก 126 องศา (แผ่นกรอง PVDF) เป็น 78 องศา และใช้เวลาในการซึมน้ำเพียง 1 นาที 20 วินาที แผ่นกรองต้านแบคทีเรีย FA-8M มีความหนา 60±3 ไมโครเมตร รูพรุน 0.40 ไมโครเมตร และความพรุน 70±3% เมื่อนำไปกรองเชื้อแบคทีเรียเปรียบเทียบกับแผ่นกรองเชิงพาณิชย์ (Nitrocellulose Membrane) ที่มีรูพรุนขนาด 0.45 ไมโครเมตร และความหนาเท่ากับ 125 ไมโครเมตร พบว่า แผ่นกรองต้านแบคทีเรีย FA-8M มีประสิทธิภาพในการแยกเชื้อแบคทีเรียออกจากน้ำได้เช่นเดียวกัน และยังพบว่าแผ่นกรองต้านแบคทีเรีย FA-8M ยังสามารถยับยั้งการเจริญของเชื้อแบคทีเรียได้ ถึงแม้จะเติมสารต้านแบคทีเรีย AgNO3 และเบนซาลโคเนียมคลอไรด์ (BKC) เพียง 0.1% ของน้ำหนักพอลิเมอร์Antibacterial Poly (vinylidene fluoride) (PVDF) nanofibers can be used to produce filter with the property of liquid filtering and bacteriostatic effect. However, its present efficiency is still dissatisfied due to the low absorption of PVDF causing the limitation of antibacterial substances diffusion. In this study, the researcher introduced hydrophilic membrane by spinning with Poly (vinyl alcohol) nanofiber (PVA) to produce FA filter. The contact angle of FA filter has been reduced from 126 deg to 78 deg with the water absorption duration only of 1 minute and 20 seconds. The FA 8M antibacterial filter has the thickness of 60±3 micrometers, a pore size of 0.40 micrometer, and the porosity of 70±3%. The FA 8M antibacterial filter was compared with the commercial nitrocellulose membrane filter with the thickness of 125 micrometers and a pore size of 0.45 micrometers showing that the FA 8M antibacterial filter can effectively separate the bacteria from the water and still contain bacteriostatic effect though AgNO3 and BKC (Benzalkonium Chloride) added only 0.1% of the polymer weight

Identification of <i>Staphylococcus aureus</i> cellular proteins disappeared after rhodomyrtone treatment.

<p>Identification of <i>Staphylococcus aureus</i> cellular proteins disappeared after rhodomyrtone treatment.</p

Two dimensional electrophoresis of the of cellular methicillin-resistant <i>S. aureus</i> proteomes.

<p>Protein extracts were prepared from rhodomyrtone-treated cells (A) and untreated control cells (B).</p

Time-kill curves of rhodomyrtone against MRSA.

<p>Viability was counted at the indicated time points by serial dilution plating. Each point represented the mean of log₁₀ ± standard deviations of three different experiments performed in duplicate.</p

Identification of <i>Staphylococcus aureus</i> cellular proteins presented after rhodomyrtone treatment.

<p>Identification of <i>Staphylococcus aureus</i> cellular proteins presented after rhodomyrtone treatment.</p

Transmission electron microscopy demonstrating the effects of rhodomyrtone on <i>S. aureus</i> ATCC 29213 morphology and ultrastructure.

<p>The bacteria were incubated in CAMHB for 18 h, media containing 0.174 µg/ml of rhodomyrtone (C, D, E, and F) and untreated control cultures (A and B). Scale bars = 1 µm (A and C) and 0.5 µm (B, D, E, and F), respectively.</p