The Staphylococcus aureus Response to Unsaturated Long Chain Free Fatty Acids: Survival Mechanisms and Virulence Implications

Staphylococcus aureus is an important human commensal and opportunistic pathogen responsible for a wide range of infections. Long chain unsaturated free fatty acids represent a barrier to colonisation and infection by S. aureus and act as an antimicrobial component of the innate immune system where they are found on epithelial surfaces and in abscesses. Despite many contradictory reports, the precise anti-staphylococcal mode of action of free fatty acids remains undetermined. In this study, transcriptional (microarrays and qRT-PCR) and translational (proteomics) analyses were applied to ascertain the response of S. aureus to a range of free fatty acids. An increase in expression of the σB and CtsR stress response regulons was observed. This included increased expression of genes associated with staphyloxanthin synthesis, which has been linked to membrane stabilisation. Similarly, up-regulation of genes involved in capsule formation was recorded as were significant changes in the expression of genes associated with peptidoglycan synthesis and regulation. Overall, alterations were recorded predominantly in pathways involved in cellular energetics. In addition, sensitivity to linoleic acid of a range of defined (sigB, arcA, sasF, sarA, agr, crtM) and transposon-derived mutants (vraE, SAR2632) was determined. Taken together, these data indicate a common mode of action for long chain unsaturated fatty acids that involves disruption of the cell membrane, leading to interference with energy production within the bacterial cell. Contrary to data reported for other strains, the clinically important EMRSA-16 strain MRSA252 used in this study showed an increase in expression of the important virulence regulator RNAIII following all of the treatment conditions tested. An adaptive response by S. aureus of reducing cell surface hydrophobicity was also observed. Two fatty acid sensitive mutants created during this study were also shown to diplay altered pathogenesis as assessed by a murine arthritis model. Differences in the prevalence and clinical importance of S. aureus strains might partly be explained by their responses to antimicrobial fatty acids

Candidiasis, Bacterial Vaginosis, Trichomoniasis and Other Vaginal Conditions Affecting the Vulva

info:eu-repo/semantics/publishedVersio

Efficacy and safety of a vaginal medicinal product containing three strains of probiotic bacteria: a multicenter, randomized, double-blind, and placebo-controlled trial

Anna Tomusiak,1 Magdalena Strus,1 Piotr B Heczko,1 Paweł Adamski,2 Grzegorz Stefański,3 Aleksandra Mikołajczyk-Cichońska,3 Magdalena Suda-Szczurek3 1Department of Microbiology, Jagiellonian University Medical College, 2Institute of Nature Conservation, Polish Academy of Sciences, 3IBSS BIOMED SA, Kraków, Poland Objective: The main objective of this study was to evaluate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether Lactobacillus colonization promotes normalization and maintenance of pH and Nugent score. Patients and methods: The study was a multicenter, randomized, double-blind, and placebo-controlled trial. Altogether, 376 women were assessed for eligibility, and signed informed consent. One hundred and sixty eligible women with abnormal, also called intermediate, vaginal microflora, as indicated by a Nugent score of 4–6 and pH >4.5 and zero or low Lactobacillus count, were randomized. Each participant was examined four times during the study. Women were randomly allocated to receive either the probiotic preparation inVag®, or a placebo (one capsule for seven consecutive days vaginally). The product inVag includes the probiotic strains Lactobacillus fermentum 57A, Lactobacillus plantarum 57B, and Lactobacillus gasseri 57C. We took vaginal swabs during visits I, III, and IV to determine the presence and abundance of bacteria from the Lactobacillus genus, measure the pH, and estimate the Nugent score. Drug safety evaluation was based on analysis of the types and occurrence of adverse events. Results: Administration of inVag contributed to a significant decrease (between visits) in both vaginal pH (P<0.05) and Nugent score (P<0.05), and a significant increase in the abundance of Lactobacillus between visit I and visits III and IV (P<0.05). Molecular typing revealed the presence of Lactobacillus strains originating from inVag in 82% of women taking the drug at visit III, and 47.5% at visit IV. There was no serious adverse event related to inVag administration during the study. Conclusion: The probiotic inVag is safe for administration to sustainably restore the healthy vaginal microbiota, as demonstrated by predominance of the Lactobacillus bacteria in vaginal microbiota. Keywords: probiotics, Lactobacillus, bacterial vaginosis, aerobic vaginitis&nbsp

A role of bacteria in inflammatory bowel disease evoked in animal models

Introduction: Inflammatory bowel disease (IBD) encompass ulcerative colitis (UC) and Crohn's disease (CD). Their etiology is attributed to interactions between various genetic, immunologic and environmental factors but the nature of these interactions is not fully understood. Objectives: The elucidate the role of the bacterial flora in the pathogenesis of IBD in immunodeficient mice (Gαi2 and CB-17 SCID models). Material and methods: Immunodeficient mice and their controls, bred in identical conditions, were sacrificed and their G.I. tracts were excised. The intestinal content and the bacteria from the mucosal surface were cultured on appropriate media in aerobic and anaerobic conditions. Strain identification was performed using commercially available biochemical tests. Selected strains were additionally identified using PCR. The presence and the quantity of bacteria in tissue samples was estimated using fluorescent in situ hybridization (FISH). Results: In mice with IBD symptoms we noted an increase in bacteria from Lactobacillus genus as well as an increase of microorganisms from Enterobacteriaceae family. In animals of the control group the bacteria were only present on the surface of the mucus layer, whilst in animals with IBD the bacteria were found attached directly to mucosal cells. Conclusions: In this study we have shown that changes in the composition of the colonic flora may be related to the pathogenesis of IBD. Further investigations are needed in this field in order to be able to modify the course of IBD

Effects of oral probiotic supplementation on gut Lactobacillus and Bifidobacterium populations and the clinical status of low-birth-weight preterm neonates: a multicenter randomized, double-blind, placebo-controlled trial

Magdalena Strus,1 Ewa Helwich,2 Ryszard Lauterbach,3 Beata Rzepecka-Węglarz,4 Katarzyna Nowicka,2 Maria Wilińska,5 Jerzy Szczapa,6 Małgorzata Rudnicka,7 Helena Sławska,8 Marek Szczepański,9 Aneta Waśko,10 Aleksandra Mikołajczyk-Cichońska,10 Anna Tomusiak-Plebanek,1 Piotr B Heczko1 1Department of Microbiology, Jagiellonian University Medical College, Kraków, Poland; 2Department of Neonatology, Institute of Mother and Child, Warszawa, Poland; 3Clinical Department of Neonatology, University Hospital, Kraków, Poland; 4Department of Neonatal Intensive Care, “UJASTEK” Medical Centre, Kraków, Poland; 5Clinical Department of Neonatology, Independent Public Clinical Hospital CMKP, Warszawa, Poland; 6Department of Neonatology, Gynecology and Obstetrics Clinical Hospital, Poznań, Poland; 7Department of Neonatology, Regional Specialist Hospital, Wrocław, Poland; 8Department of Neonatology, Specialist Hospital No. 2, Bytom, Poland; 9Clinic Department of Neonatology and Neonatal Intensive Care, University Clinical Hospital, Białystok, Poland; 10Medical Department, IBSS BIOMED S.A., Kraków, Poland Aim: Probiotic bacteria administered directly after birth to preterm neonates may improve gastrointestinal function and may reduce the incidence of late-onset sepsis, which is a frequent complication in this group. Purpose: The main objective of this study was to evaluate whether a new probiotic bacterial mixture of Lactobacillus rhamnosus KL53A and Bifidobacterium breve PB04 given to preterm, low-birth-weight neonates would influence composition of their gut microbiota and sepsis rates. Patients and methods: This study was a multicenter, randomized, double-blind, placebo-controlled trial conducted in clinical centers of neonatal care in Poland. A probiotic or placebo preparation was given twice daily to 181 preterm low-birth-weight neonates who were eligible for enteral feeding between July 2012 and July 2013. The probiotic was given to 90 neonates, while placebo was given to 91 neonates. The gut microbiota was monitored by microbiological analysis of stool samples. Sepsis episodes were detected on the basis of clinical and laboratory findings and confirmed by blood cultures. Results: Tested probiotic administration resulted in continuous increase of the Lactobacillus and Bifidobacterium counts in the gut microbiota. The applied tested strains successfully colonized the neonates gut since they were present in over 90% of stool samples, which was confirmed by molecular analysis. Regardless of the study group (probiotic or placebo), B. breve ­colonization correlated with lower staphylococcal sepsis incidence, which was irrespective of whether ­probiotics were given. No sepsis case caused by strains included in study probiotic was recorded. Conclusion: Appropriately selected and characterized probiotic bacteria may be safely given to preterm neonates to normalize their distorted gut microbiota and may contribute to lower staphylococcal sepsis rates. Keywords: probiotics, LBW neonates, staphylococcal sepsis, gut microbiota, Lactobacillus, Bifidobacteriu