Biofilm formation by multidrug resistant Enterobacteriaceae strains isolated from solid organ transplant recipients

Solid organ transplant (SOT) recipients are especially at risk of developing infections by multidrug resistant bacteria (MDR). In this study, the biofilm-forming capability of 209 MDR strains (Escherichia coli n = 106, Klebsiella pneumoniae n = 78, and Enterobacter spp. n = 25) isolated from rectal swabs in the first 48 hours before or after kidney (93 patients), liver (60 patients) or kidney/pancreas transplants (5 patients) were evaluated by using a microplate assay. Thirty-nine strains were isolated before transplant and 170 strains were isolated post-transplant. Overall, 16% of E. coli strains, 73% of K. pneumoniae strains and 4% Enterobacter strains showed moderate or strong biofilm production. Nine strains isolated from infection sites after transplantation were responsible of infections in the first month. Of these, 4 K. pneumoniae, 1 E. coli and 1 Enterobacter spp. strains isolated pre-transplant or post-transplant as colonizers caused infections in the post-transplant period. Our results suggest that in vitro biofilm formation could be an important factor for adhesion to intestine and colonization in MDR K. pneumoniae strains in SOT recipients, but this factor appears to be less important for MDR E. coli and Enterobacter spp.

Selective intestinal decontamination for the prevention of early bacterial infections after liver transplantation

Bacterial infection in the first month after liver transplantation is a frequent complication that poses a serious risk for liver transplant recipients as contributes substantially to increased length of hospitalization and hospital costs being a leading cause of death in this period. Most of these infections are caused by gram-negative bacilli, although gram-positive infections, especially Enterococcus sp. constitute an emerging infectious problem. This high rate of early postoperative infections after liver transplant has generated interest in exploring various prophylactic approaches to surmount this problem. One of these approaches is selective intestinal decontamination (SID). SID is a prophylactic strategy that consists of the administration of antimicrobials with limited anaerobicidal activity in order to reduce the burden of aerobic gram-negative bacteria and/or yeast in the intestinal tract and so prevent infections caused by these organisms. The majority of studies carried out to date have found SID to be effective in the reduction of gram-negative infection, but the effect on overall infection is limited due to a higher number of infection episodes by pathogenic enterococci and coagulase-negative staphylococci. However, difficulties in general extrapolation of the favorable results obtained in specific studies together with the potential risk of selection of multirresistant microorganisms has conditioned controversy about the routinely application of these strategies in liver transplant recipients.

Pandemic H1N1 influenza-associated myocarditis in a patient with Castleman’s disease

We report on a patient with longstanding multicentric Castleman’s disease, hyaline-vascular type, who presented with nearly-fatal myocarditis associated with a 2009 pandemic H1N1 influenza virus infection. This is the first case of such an association described in the literature.

Impact of education program on influenza vaccination rates in Spain

OBJECTIVES

To assess the impact of a simple education program on adherence to influenza vaccination.

STUDY DESIGN

Randomized open controlled study.

METHODS

The education program group (EPG) received an education program via surface mail, consisting of information regarding the effectiveness and safety of the influenza vaccine. The no-program group (NPG) received no intervention. All patients in 13 primary care practices in the city of Castellón, Spain, were included if they were 60 years or older on the first day of the 2009 seasonal influenza vaccination campaign.

RESULTS

There were a total of 2402 participants (mean age 70.4 [± 7.1] years); 1338 (55.7%) were women. In 2009, 950 participants (39.5%) received the vaccine, including 900 of the same participants (37.5%) who had received it in 2008 (P = .14). Of those vaccinated in 2009, 501 (52.7%) belonged to the EPG and 449 (47.3%) to the NPG (P = .01). In a logistic regression analysis we found an association between adherence to vaccination in 2009 and both vaccination in the previous year and receiving the educational intervention. Influenza-related morbidity was similar in both groups during the 7 months after vaccination.

CONCLUSIONS

A mailed reminder program was effective to improve influenza vaccination rate, but only to a limited extent. Vaccination the previous year was the main predictor of adherence to vaccination. More programs are needed to improve vaccination rates in the study community.

Interobserver discrepancy in liver fibrosis using transient elastography

Transient elastography is a useful method to assess liver fibrosis, but uncertainties still exist regarding reliability and reproducibility of the technique. We aimed to improve knowledge on interobserver variability with the procedure and tried to find factors associated with such variability. This was a cross-sectional study to compare the results of transient elastography performed by two different operators, one test made just after the other. We assessed both results with correlation tests and with repeated parametric or nonparametric tests, as needed. We also carried out a multivariate analysis to find factors associated with discrepancy in the results obtained by the two operators. We included a total of 333 pairs of transient elastography tests, belonging to 274 different patients. A total of 325 pairs of tests (97.6%) were valid. Results of the first and the second tests were, respectively, median (and interquartile range) of direct measurement 6.2 (4.6-10.6) and 6.0 (4.4-10.1) kPa (P = 0.012), and mean ± standard deviation of log(10) of direct measurement 0.892 ± 0.316 and 0.871 ± 0.324 (P = 0.001). In 87 pairs of tests (26.7%), a discrepancy of at least 2 kPa between both results was found, and in 15 pairs of tests (4.6%), a discrepancy of at least 10 kPa was found. Discordance of at least one stage between both measurements was noted in 74 pairs of tests (22.8%). An association was found between higher stiffness and discrepancy between both operators (P < 0.001). Although transient elastography is a very convenient test to assess liver fibrosis in clinical practice, interobserver discrepancy in results is common and represents a significant problem with the technique. Discrepant results are more common in patients with higher values of stiffness.

Hepatitis C virus co-infection and sexual risk behaviour are associated with a high homocysteine serum level in HIV-infected patients

BACKGROUND AND AIMS

A better understanding of the relationship of homocysteine with cardiovascular risk factors is needed. The objectives of this study were to assess the serum level of homocysteine in HIV-infected patients and to analyse the possible association of increased levels of the amino acid with cardiovascular risk factors, demographic and clinical characteristics of participants.

METHODS

Cross-sectional study carried out as a supplementary task to the usual controls necessary in HIV-infected patients in the outpatient clinic of the Hospital General of Castellon, Spain. For two consecutive visits the demographic, clinical and HIV-related characteristics and blood analyses results were obtained for each participant. Homocysteine serum level was documented and the possible association of the amino acid with all the other study variables was assessed with a multiple linear regression analysis.

RESULTS

A total of 145 patients were included. The mean homocysteine serum level of all participants was 11.9 ± 5.9 µmol/L. A total of 54 patients (37%) presented homocysteine serum levels higher than the upper limit of normal. An association was found between higher homocysteine serum level and the following variables: family history of early coronary disease (P = 0.027), sexual HIV risk behaviour (P = 0.016), hepatitis C virus co-infection (P = 0.002), higher height (P = 0.002), higher diastolic blood pressure (P = 0.049), lower serum level of folic acid (P <0.001), and lower serum level of vitamin B12 (P = <0.001).

CONCLUSION

In the HIV population, increased homocysteine serum level is associated with sexual risk behaviour and hepatitis C virus coinfection.