Mariassunta Del Pezzo

Impact of Clostridium difficile Infection on Pediatric Inflammatory Bowel Disease

OBJECTIVES To determine the prevalence of and explore possible differences in the risk for and symptoms of Clostridium difficile infection between patients with and without inflammatory bowel disease (IBD). STUDY DESIGN Stool specimens from subjects with and without IBD were evaluated for the presence of C difficile toxins. Demographic information, diagnosis, anatomic location, disease activity, IBD therapy, hospitalizations, and antibiotic and proton pump inhibitor (PPI) exposures were recorded. RESULTS A total of 193 specimens were collected from 81 patients with IBD and 112 patients without IBD. The prevalence of C difficile infection was significantly greater in the patients with IBD than in those without IBD (P = .004; chi2 = 0.003; odds ratio = 3.3; 95% confidence interval = 1.5 to 7.6). In the patients with IBD, the prevalence of active disease was significantly greater in the C difficile-infected patients than in the uninfected patients (P < .0001). Colonic involvement was found in all patients with IBD. The specific type of IBD, IBD therapy, and antibiotic and PPI exposures that predisposed patients with IBD to C difficile infection were not identified, whereas hospitalization was significantly more frequent in the patients without IBD (P = .025). CONCLUSIONS Our findings indicate that in children, IBD is associated with an increased prevalence of C difficile infection. The specific risk factors reported in adults were not identified in these children, suggesting the possible involvement of other mechanisms for acquiring the pathogen.

Gastroduodenal lesions and Helicobacter pylori infection in dyspeptic patients with and without chronic renal failure

Background.  Patients with chronic renal failure (CRF) often have dyspeptic symptoms and may develop peptic disease or digestive disorders leading to severe gastrointestinal complications. The primary aim of this study was to evaluate the prevalence of peptic lesions and Helicobacter pylori infection, and the severity of dyspeptic symptoms, in dyspeptic patients with and without CRF. Our secondary aim was to investigate whether uremic status may affect the diagnostic efficiency of the [13]C‐urea breath test ([13]C‐UBT).

Rapid identification of Burkholderia cepacia complex species recovered from cystic fibrosis patients using matrix-assisted laser desorption ionization time-of-flight mass spectrometry

The aim of this study was to establish the identification ability of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) for bacteria of Burkholderia cepacia complex (Bcc) and to compare these results with those obtained by a molecular method (PCR-RFLP). A total of 57 isolates was used in the study. Isolates were collected from 31 patients attending the Regional Cystic Fibrosis Unit from January 2001 to December 2005. For phenotypic identification, both automated and manual systems were used. Using mass spectrometry, we identified all 57 isolates, previously identified by molecular method. Of these, 28 isolates were identified as B. cenocepacia, although not differentiated further into lineages. Moreover, other isolates were identified as B. cepacia (12 isolates), B. stabilis (12 isolates), and B. vietnamiensis (5 isolates). Our data indicate a good correlation between the two approaches.

Multicenter Evaluation of the MB-Redox Medium Compared with Radiometric BACTEC System, Mycobacteria Growth Indicator Tube (MGIT), and Lowenstein-Jensen Medium for Detection and Recovery of Acid-Fast Bacilli

MB-Redox is a new manual culture system designed for the recovery of mycobacteria from clinical specimens. It consists of a liquid medium (modified Kirchner medium) containing a redox indicator, a colorless tetrazolium salt, which is reduced to colored formazan by actively growing mycobacteria. Acid fast bacilli (AFB) are easily detected in the medium as pink to purple pinhead-sized particles. We report the results of a multicenter study (involving four Italian microbiology laboratories processing 2370 clinical specimens) aiming to evaluate the recovery rates of AFB and time required for their detection by using the MB-Redox medium. Two different protocols were set up: in Protocol A (1580 specimens) the performance of MB-Redox was compared with those of the radiometric BACTEC 460 TB system (B460) and Löwenstein-Jensen medium (L-J), whereas in Protocol B (790 specimens) it was compared with those of the Mycobacteria Growth Indicator Tube (MGIT) and L-J. A total of 213 mycobacteria were recovered, including 172 Mycobacterium tuberculosis complex (MTB) isolates and 41 nontuberculous mycobacteria (NTM) isolates. In Protocol A, recovery rates were 81% for MB-Redox system, 84% for B460 system, and 77% for L-J. In Protocol B the recovery rates by individual system were 87, 83, and 76% for MB-Redox, MGIT, and L-J, respectively. Differences in both the protocols were not statistically significant. The MB-Redox system plus L-J (Combination 1) recovered 94% of the isolates in Protocol A and 93% in Protocol B, while B460 plus L-J (Combination 2) and MGIT plus L-J (Combination 3) detected 91 and 89% of all mycobacteria isolates respectively. No statistically significant differences were found among the combinations. The mean time to detection of mycobacteria was 16.3 days in Protocol A and 19.1 days in Protocol B with the MB-Redox system, 22.4 and 25.9 days with L-J, 13.2 days with B460, and 18.2 days with MGIT. The contamination rates were 2.1, 2.0, 1.9, and 3.6 for MB-Redox, B460, MGIT, and L-J respectively. The MB-Redox is a reliable, nonradiometric system for growth and detection of mycobacteria. When used in combination with a solid medium it proved to be an effective replacement for B460. The MB Redox system is a labor-intensive method requiring much handling during the visual reading procedures.

IgA immune response against the mycobacterial antigen A60 in patients with active pulmonary tuberculosis

Searching for IgG and IgM against the mycobacterial antigen A60 has been recognized as a potential diagnostic tool for pulmonary tuberculosis. The role of detection of anti-A60 IgA in improving diagnostic accuracy of serology is not well known. In this study we measured with ELISA serum levels of both anti-A60 IgG and IgA in 216 subjects. 88 healthy volunteers (44 PPD- and 44 PPD+), 44 patients suffering from nontuberculous lung disease and 15 subjects with healed pulmonary tuberculosis constituted the control population; 69 patients with active pulmonary tuberculosis (35 cavitary forms, 26 productive forms and 8 miliary forms) were examined. The sensitivity of IgG test was 73.9% in pulmonary tuberculosis (77.1% in cavitary forms, 65.4% in productive forms, 87.5% in miliary forms); the specificity of the test was 95.9%. For the IgA test we observed a sensitivity of 72.5% (74.3 in cavitary forms, 69.2% in productive forms, 75.0 in miliary forms) and a specificity of 93.9%. Combination of the two tests increased the sensitivity to 84.0% (+10.1% compared to IgG test, +11.5% compared to IgA test); the specificity decreased to 92.5% (-3.4% vs. IgG test; -1.4 vs. IgA test). In conclusion, the combined use of evaluation of anti-A60 IgG and IgA increases the accuracy of serological diagnosis of pulmonary tuberculosis.

Sphingobacterium respiratory tract infection in patients with cystic fibrosis

BackgroundBacteria that belong to the genus Sphingobacterium are Gram-negative, non-fermentative bacilli, ubiquitous in nature and rarely involved in human infections. The aims of this study were to evaluate the epidemiology of infection by Sphingobacterium in a cohort of patients affected by Cystic Fibrosis (CF), the antibiotic susceptibility and the DNA fingerprinting of the isolated strains and to analyze some clinical outcomes of the infected patients.FindingsBetween January 2006 and June 2008, patients (n = 332) attending the Regional CF Unit in Naples, Italy, were enrolled.Sputum samples were processed for microscopic, cultural, phenotypic identification and antibiotic susceptibility testing. DNA fingerprinting was performed by pulsed-field gel electrophoresis (PFGE). A total of 21 strains of Sphingobacterium were isolated from 7 patients (13 of S. spiritovorum, 8 of S. multivorum). S. multivorum isolates were more resistant than those of S. spiritovorum. PFGE profiles were in general heterogeneous, which suggested independent circulation.ConclusionsThis is the first Italian report about respiratory tract infections by Sphingobacterium in CF patients. In our cohort, these infections were not associated with a deterioration of pulmonary function during the follow-up period. Although the exact role of this microorganism in CF lung disease is unknown and the number of infected patients was small, this study could represent an important starting-point for understanding the epidemiology and the possible pathogenic role of Sphingobacterium in CF patients.

Clostridium difficile and pediatric inflammatory bowel disease: A prospective, comparative, multicenter, ESPGHAN study

Background:Clostridium difficile infection is associated with pediatric inflammatory bowel disease (IBD) in several ways. We sought to investigate C. difficile infection in pediatric patients with IBD in comparison with a group of children with celiac disease and to evaluate IBD disease course of C. difficile infected patients. Methods:In this prospective, comparative, multicenter study, 211 pediatric patients with IBD were enrolled from October 2010 to October 2011 and tested for the presence of C. difficile toxins A and B in their stools at 0, 6, and 12 months. During the same study period, stool specimens for C. difficile toxins analysis were collected from 112 children with celiac disease as controls. Results:Clostridium difficile occurrence was significantly higher in patients with IBD compared with patients with celiac disease (7.5% versus 0.8%; P = 0.008). Clostridium difficile was associated with active disease in 71.4% of patients with IBD (P = 0.01). Colonic involvement was found in 85.7% of patients with C. difficile. Antibiotics, proton pump inhibitors, hospitalization, and IBD therapies were not associated with increased C. difficile detection. At 12 months, a higher number of C. difficile–positive patients at the enrollment started immunosuppressant/biological therapy compared with patients without C. difficile (P = 0.01). At 6 and 12 months, patients with C. difficile were more frequently in active disease than patients without C. difficile (P = 0.04; P = 0.08, respectively). Hospitalizations were higher at 6 months in C. difficile group (P = 0.05). Conclusions:In conclusion, this study demonstrates that pediatric IBD is associated with increased C. difficile detection. Patients with C. difficile tend to have active colonic disease and a more severe disease course.

In vitro resistance to macrolides and clindamycin by Group B Streptococcus isolated from pregnant and nonpregnant women.

Background. Despite the introduction of screening bases intrapartum prophylaxis, Streptococcus agalactiae is still an important etiological agent of perinatal infections. The increasing rate of resistance and the differences in resistance pattern among countries suggest that a program of surveillance at the institutional level is important in determining optimal prophylaxis. In contrast, knowledge on GBS epidemiology in Italy is limited, and no data are available in the Southern region of the country. We sought to determine the occurrence of resistance to macrolides and clindamycin of GBS isolates in pregnant and nonpregnant women. Methods. Between 2005 and 2008, 1346 vaginal and 810 rectovaginal swabs were obtained from pregnant and not-pregnant women. Results. The occurrence of macrolides and clindamycin resistance was 16.5% in 2005 increasing up to 69.9% in 2008. A high percentage of isolates was resistant to tetracycline through all the study period with no statistically significant annual. Conclusions. In our cohort, an increase of in vitro resistance of GBS to macrolides and clindamycin is clearly evident. The discordance with reports from different countries emphasize the crucial role of microbiological methods in setting possible therapeutic strategies.