Tuesday, May 19, 2009

Antibiotics and probiotics in inflammatory bowel disease: why, when, and how

Antibiotics and probiotics in inflammatory bowel disease: why, when, and how
Curr Opin Gastroenterol. 2009 May 11

Prantera C, Scribano ML.
Azienda Ospedaliera San Camillo-Forlanini, Rome, Italy.

PURPOSE OF REVIEW: To summarize recent evidence on the role of intestinal bacteria in inflammatory bowel diseases, and of antibiotics and probiotics in their treatment. The implications connected with the use of antibiotics are also examined.

RECENT FINDINGS: The hypothesis that Mycobacterium paratuberculosis could be a causative agent of Crohn's disease has not been confirmed by a large trial on symptomatic patients treated by a combination of antibiotics active against this bacterium. An increased number of adherent-invasive Escherichia coli have been found in the intestinal tissue of patients with Crohn's disease, but their role in the pathogenesis of this condition remains to be defined. The combination of metronidazole and azathioprine, associating the effects of a reduced bacterial load with immunosuppression, appears to be a therapeutic option to decrease the recurrence of postoperative Crohn's disease in high-risk patients. However, concerns are raised by the possibility that antibiotics may induce disease relapse due to Clostridium difficile infection.

SUMMARY: Recent literature provides increasing support for the use of antibiotics in Crohn's disease, although the side effects limit their long-term use. The efficacy of antibiotics in ulcerative colitis is not confirmed by the available literature, except in severe colitis. More trials are needed to support the use of probiotics as therapy in inflammatory bowel disease.

PMID: 19444096 [PubMed - as supplied by publisher]

Antibiotic Use in Premature Infants After Discharge From the Neonatal Intensive Care Unit.

Antibiotic Use in Premature Infants After Discharge From the Neonatal Intensive Care Unit.
Clin Pediatr (Phila). 2009 May 15

Lorch SA, Wade KC, Bakewell-Sachs S, Medoff-Cooper B, Silber JH, Escobar GJ.

Using a retrospective cohort of premature infants, we constructed multivariable Poisson models to determine factors associated with the receipt of antibiotics during the first year after discharge, N = 891. Black race (incidence rate ratio 1.80 compared with White infants, P = .008), male gender (incidence rate ratio 1.44; P = .007), bronchopulmonary dysplasia (incidence rate ratio 1.47; P = .04), and each additional child at home (incidence rate ratio 1.21, P = .002) increased the receipt of antibiotics for any reason. Male gender and additional children at home increased the receipt of nonrecommended antibiotics, while Black infants received care at facilities that prescribed more nonrecommended antibiotics. Even in a high-risk population of children, factors other than the medical history and presentation of the child may alter antibiotic prescription patterns and result in variations in care.

PMID: 19448131 [PubMed - as supplied by publiusher]

Antimicrobial and antibiofilm efficacy of triclosan and DispersinB(R) combination

Antimicrobial and antibiofilm efficacy of triclosan and DispersinB(R) combination
Antimicrob Chemother. 2009 May 14

Darouiche RO, Mansouri MD, Gawande PV, Madhyastha S.
Center for Prostheses Infections and Infectious Disease Section, Michael E. Debakey Veterans Affairs Medical Center and Baylor College of Medicine, Houston, TX, USA.

Objectives: The objectives of this study were to examine: (i) synergy of the combination of triclosan and DispersinB((R)) (DspB); (ii) in vitro efficacy and durability of triclosan + DspB-coated vascular catheters; and (iii) in vivo efficacy of triclosan + DspB-coated catheters compared with chlorhexidine-silver sulfadiazine (CH-SS)-coated and uncoated (control) vascular catheters in preventing colonization by Staphylococcus aureus.

Methods: We investigated the potential synergistic antimicrobial and antibiofilm activity of triclosan and DspB by biofilm assays. The in vitro antimicrobial efficacy of triclosan + DspB-coated catheters was determined by microbial colonization assays. Antimicrobial durability of the coated catheters was tested by soaking segments in bovine serum for 7 days and determining antimicrobial activity, and by a serial plate transfer method. The in vivo efficacy of triclosan + DspB-coated catheters compared with CH-SS-coated and uncoated catheters was assessed by subcutaneous implantation of segments in a rabbit model of S. aureus infection.

Results: The combination of triclosan and DspB showed synergistic antimicrobial and antibiofilm activity against S. aureus, Staphylococcus epidermidis and Escherichia coli, significantly reduced bacterial colonization (P less then 0.05) and generally demonstrated a prolonged superior antimicrobial activity against clinical pathogens compared with CH-SS-coated catheters. Triclosan + DspB-coated and CH-SS-coated catheters exhibited equal in vivo efficacy (P less then/= 0.05) in reducing colonization by S. aureus compared with uncoated catheters.

Conclusions: Catheters coated with the triclosan + DspB combination showed synergistic, broad-spectrum and durable antimicrobial activity. Furthermore, the in vivo efficacy of catheters coated with this unique antimicrobial/antibiofilm composition prompts clinical evaluation of such an innovative approach.

PMID: 19447791 [PubMed - as supplied by publisher]

Maintaining a Sterile Urinary Tract: The Role of Antimicrobial Peptides

Maintaining a Sterile Urinary Tract: The Role of Antimicrobial Peptides
Urol. 2009 May 16

Ali AS, Townes CL, Hall J, Pickard RS.
Newcastle University, Newcastle upon Tyne, United Kingdom.

PURPOSE: The normally sterile urinary tract is constantly challenged by microbial invasion leading to a high prevalence of isolated, recurrent and catheter associated urinary tract infection. The continuous emergence of bacterial resistance following overuse of traditional antibiotics requires the urgent development of alternative treatment strategies. The involvement of innate immune mechanisms in host defense is an emerging field of microbiological research with recent work focusing on the urinary tract. We performed a comprehensive literature review to establish the current level of knowledge concerning the role of innate immunity and specifically antimicrobial peptides within the human urinary tract.

MATERIALS AND METHODS: A systematic review of the literature was performed by searching PubMed(R) from January 1988 to September 2008. Electronic searches were limited to the English language using the key words antimicrobial, peptide and urinary. Reference lists from relevant reviews were hand searched and appropriate articles were retrieved. The proceedings of conferences held in the last 2 years by the American Urological Association, European Association of Urology and British Association of Urological Surgeons were also searched.

RESULTS: Several defensive mechanisms have evolved in response to the threat of urinary infection, comprising physical factors and innate immune responses characterized by the expression of antimicrobial peptides. Antimicrobial peptides are small (less than 10 kDa), cationic and amphipathic peptides of variable length, sequence and structure with broad spectrum killing activity against a wide range of microorganisms including gram-positive and gram-negative bacteria. Several antimicrobial peptides have been identified in the urinary tract, and the amount and type of antimicrobial peptides expressed vary according to tissue source and disease state. These differences may reflect altered levels of innate response and, hence, susceptibility to infection. Antimicrobial peptides are already being exploited therapeutically for skin and endovascular catheter infection, and prospects for useful application in the urinary tract are emerging.

CONCLUSIONS: Although investigation of antimicrobial peptide function in the human urinary tract is at an early stage, it is clear that there is considerable potential for the future design of novel therapeutic strategies. More knowledge is needed concerning the pathway of involvement of antimicrobial peptides in the maintenance of urinary tract sterility and the ways in which this is altered during active infection.

PMID: 19447447 [PubMed - as supplied by publisher]

Prospective analysis of central venous catheter colonization and related factors

Prospective analysis of central venous catheter colonization and related factors
Enferm Clin. 2009 May 14

Pérez Castro I, Iborra Obiols MI, Comas Munar MD, Yrurzun Andreu R, Sanz Moncusí M, Lahoz Simón C, Gómez Montoya MI, Comallonga Bartomeu T, Navasa Anadón M.
Institut de Malalties Digestives i Metabóliques, Hospital Clínic de Barcelona, Barcelona, España.

OBJECTIVE: To evaluate the incidence of central venous catheter (CVC) colonization in inpatient units of the Institut de Malalties Digestives i Metabòliques (IMDiM) of Hospital Clinic (Barcelona, Spain) with a view to reducing the risk of infection.

METHOD: A 4-month descriptive, prospective and longitudinal study was performed. A total of 230 patients admitted to the IMDiM with CVC were included during the study period. At catheter removal, the tip was cultured and, if the patient had fever, two blood cultures were also obtained. A database was created. Data were analyzed using SPSS v.11.0. Variables were compared with the Chi-square and Student's t-tests and a multivariate analysis was performed using Cox logistic regression. A value of P 0.05

RESULTS: Catheter tip culture was positive in 45.2%. The rate of catheter-related bloodstream infections was 2.9 per thousand catheter-days, which was clinically significant. The probability of catheter tip contamination 10 days after placement was 25%. Multivariate analysis revealed that the independent variables associated with a higher risk of infection were catheter type, changes of dressing, and infected bacterial stopcocks.

CONCLUSIONS: These results suggest that: 1) the protocol for catheter insertion and care should be reviewed and updated, 2) catheter removal should be considered after the 10th day, 3) the appropriate type of catheter should be selected, the catheter with the lowest number of lumens should be used, and changes of catheter dressing should be reduced.

PMID: 19447058 [PubMed - as supplied by publisher]