Showing 14841–14847 of 14,847 results for "Zvolska Kamila"

Journals 2018 EN

Social Networks and Its Impact on Women's Awareness, Interest, and Uptake of HIV Pre-exposure Prophylaxis (PrEP): Implications for Women Experiencing Intimate Partner Violence

Tiara C. Willie · Jamila K. Stockman · Danya E. Keene +3 more

In the United States, women represent less than 5% of all pre-exposure prophylaxis (PrEP) users. Social networks may promote and/or inhibit women's PrEP awareness, which could influence PrEP intentions. Furthermore, women experiencing intimate partner violence (IPV) may have smaller, less supportive networks, which could deter or have no impact on PrEP care engagement. This study examined associations between network characteristics and women's PrEP awareness, interest, uptake, and perceived candidacy and analyzed IPV as an effect modifier.

Lippincott Williams & Wilkins
Journals 2018 EN

In vivo atomic force microscopy–infrared spectroscopy of bacteria

Kamila Kochan · David Pérez-Guaita · Julia Pissang +5 more

A new experimental platform for probing nanoscale molecular changes in living bacteria using atomic force microscopy–infrared (AFM–IR) spectroscopy is demonstrated. This near-field technique is eminently suited to the study of single bacterial cells. Here, we report its application to monitor dynamical changes occurring in the cell wall during cell division inStaphylococcus aureus using AFM to demonstrate the division of the cell and AFM–IR to record spectra showing the thickening of the septum. This work was followed by an investigation into single cells, with particular emphasis on cell-wall signatures, in several bacterial species. Specifically, mainly cell wall components fromS. aureus andEscherichia coli containing complex carbohydrate and phosphodiester groups, including peptidoglycans and teichoic acid, could be identified and mapped at nanometre spatial resolution. Principal component analysis of AFM–IR spectra of six living bacterial species enabled the discrimination of Gram-positive from Gram-negative bacteria based on spectral bands originating mainly from the cell wall components. The ability to monitorin vivo molecular changes during cellular processes in bacteria at the nanoscale opens a new platform to study environmental influences and other factors that affect bacterial chemistry.

Royal Society
Journals 2018 EN

Next-generation sequencing analysis of new genotypes appearing during antiviral treatment of chronic hepatitis C reveals that these are selected from pre-existing minor strains

Iwona BukowskaOśko · Karol Perlejewski · Caraballo Cortés Kamila +8 more

Coinfection with more than one hepatitis C virus (HCV) genotype is common, but its dynamics, particularly during antiviral treatment, remain largely unknown. We employed next-generation sequencing (NGS) to analyse sequential serum and peripheral blood mononuclear cell (PBMC) samples in seven patients with transient presence or permanent genotype change during antiviral treatment with interferon and ribavirin. Specimens were collected right before the therapy initiation and at 2, 4, 6, 8, 12, 20, 24, 36, 44 and 48 weeks during treatment and 6 months after treatment ceased. A mixture of two different genotypes was detected in the pretreatment samples from five patients and the minor genotype constituted 0.02 to 38 %. A transient or permanent change of the predominant genotype was observed in six patients. In three cases genotype 3 was replaced as the predominant genotype by genotype 4, in two cases genotype 3 was replaced by genotype 1, and in one subject genotype 1 was replaced by genotype 4. The PBMC- and serum-derived sequences were frequently discordant with respect to genotype and/or genotype proportions. In conclusion, pre-existing minor HCV genotypes can be selected rapidly during antiviral treatment and become transiently or permanently predominant. In coinfections involving genotype 3, genotype 3 was eliminated first from both the serum and PBMC compartments. The PBMC- and serum-derived HCV sequences were frequently discordant with respect to genotype and/or genotype proportions, suggesting that they constitute separate compartments with their own dynamics.

Microbiology Society
Journals 2018 EN

Insights into the initiation of chromosome II replication of the pressure-loving deep-sea bacterium Photobacterium profundum SS9

Kamila K. Myka · Peter McGlynn · Gail P. Ferguson

How DNA metabolism is adapted to survival of organisms such as the bacterium Photobacterium profundum SS9 at high pressure is unknown. Previously, a high pressure-sensitive P. profundum SS9 transposon mutant (FL31) was identified, with an insertion in a putative rctB gene. The Vibrio cholerae RctB protein is essential for replication initiation at the origin of chromosome II, oriCII. Using a plasmid-based system in E. coli we have identified the replication origin of chromosome II from P. profundum SS9 and have shown that the putative rctB gene, disrupted in FL31, is essential for oriCII function. Moreover, we found that a region corresponding to the V. cholerae oriCII incompatibility region (incII) exerts an inhibitory effect on P. profundum oriCII. The truncated rctB gene in FL31 confers insensitivity to incII inhibition, indicating that the C-terminus of RctB is important for the negative regulation of replication. The RctB proteins of V. cholerae and P. profundum are partially interchangeable, but full functionality is achieved only with the cognate origin. Our findings provide the first characterization of the replication origin of chromosome II in a deep-sea bacterium.

Microbiology Society