Antonietta Lambiase

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.

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.

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.

Typing of vancomycin-resistant Enterococcus faecium strains in a cohort of patients in an Italian intensive care Unit.

Background:Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial infections. The increase of vancomycin-resistant Enterococcus faecium (VR-Efm) in an intensive care unit (ICU) of an Italian university hospital from 2003 through 2004, led us to evaluate the phenotypic and genetic features of these strains. The prevalence of different bacterial species in this ICU is described. The antibiotic resistance profiles of VR-Efm strains, their van-genotype and pulsed-field gel electrophoresis (PFGE) profiles were also analyzed.Materials and Methods:From January 2003 to December 2004, VR-Efm strains were collected from several biological samples. Bacteria were identified using standard biochemical reactions and automated systems. Antibiotic susceptibility was evaluated by disk diffusion and microdilution methods. Resistance to glycopeptides was confirmed by the E test. Vancomycin-resistant genotypes (vanA, vanB) were identified by PCR. Strains were typed by PFGE.Results:Fifty E. faecium strains were isolated from a total of 700 patients. Of these, 26 were vancomycin-resistant and were isolated from 26 different patients. We also found one strain with resistance to linezolid. The vanA genotype was identified in 20/26 strains and vanB in the remaining strains. A major pulsed-field cluster (“A”) was identified. In this cluster, 14 strains were identified (A1–A14) and 25 out of 26 VR-Efm belonged to it. Only one strain showed a different pattern (strain type “B”). All isolates with the vanA genotype belonged to cluster “A”, therefore five out of six isolates with the vanB genotype belonged to cluster A. The only strain with type B pattern was the vanB genotype.Conclusions:Isolation of VR-Efm was very frequent (52%) in our cohort of patients and the vanA genotype was the most frequent (77%). We found 25 out of 26 VR-E. faecium strains to be epidemiologically related by PFGE (cluster A). Strains with distinct genotypes shared closely related PFGE profiles. The occurrence of one major cluster among patients of a single unit indicated intra-facility VRE transmission.

Serum In Vivo and In Vitro Activity of Single Dose of Ertapenem in Surgical Obese Patients for Prevention of SSIs

BackgroundDespite progress made in the control of post-operative infections, the incidence of surgical site infections (SSIs) is still high. An improper perioperative antibiotic use can expose patients to the risk of resistant microorganisms, and, in surgical obese patients, the drug dosage and infusion time are critical points. The aim of our study was to evaluate the effectiveness of ertapenem in the prophylaxis of SSIs in obese patients undergoing general or bariatric surgery.MethodsA total of 63 obese patients, candidates for several surgical interventions, were enrolled and divided into two groups. Patients received antibiotic prophylaxis before surgery: the case group received venous infusion of ertapenem; the control group received standard prophylaxis. Serum samples were tested for antimicrobial activity against Gram-positive and Gram-negative bacteria.ResultsAfter single-dose ertapenem in obese patients, we registered in vitro activity of sera against the growth of non-extended beta lactamase (ESBL)-producing Escherichia coli, Proteus mirabilis, Citrobacter freundii, Enterobacter cloacae, and non-ESBL-producing Klebsiella pneumoniae. Moreover, methicillin-sensitive Staphylococcus aureus and Streptococcus viridans were also inhibited. We found in vivo efficacy according to clinical monitoring: at the weekly and monthly follow-ups, one patient in the case group and six patients in the control group presented superficial incisional SSIs.ConclusionsThese preliminary results are suggestive of the efficacy of ertapenem in perioperative prophylaxis of SSIs in obese patients; however, they need to be confirmed by further investigations and more defined trials.

FORMAZIONE DI BIOFILM IN VITRO DA PARTE DI CEPPI DI STAPHYLOCOCCUS AUREUS SENSIBILI E RESISTENTI ALLA METICILLINA ISOLATI DA PAZIENTI CON FIBROSI CISTICA

L’eziologia dell’ infezione polmonare in Fibrosi Cistica (CF) è ascrivibile a diversi patogeni batterici che possono essere abili a formare biofilm in tale sede, abilità conferente vantaggi quali protezione dalla risposta immunitaria ed antibiotico-resistenza. Scopo dello studio è analizzare la capacità di produzione di biofilm da parte di ceppi di Staphylococcus aureus sia sensibili che resistenti alla meticillina (MSSA e MRSA) isolati da campioni respiratori di pazienti CF. A tal fine sono stati utilizzati ceppi di MSSA (n=30) e ceppi di MRSA (n=30) isolati da pazienti in follow-up presso il Centro di Riferimento per la CF Campano, nel periodo 2003-2006. Per valutare l’aderenza batterica, abbiamo utilizzato un metodo spettrofotometrico per cui inoculi batterici cresciuti in TSB sono poi diluiti con TSB fresco e con TSB privo di glucosio. Aliquote di tali inoculi sono poste in micropiastre ed incubate per 18 h a 37°C. Dopo un lavaggio con PBS, i pozzetti sono colorati con cristal violetto e l’aderenza alle superfici è letta allo spettrofotometro (570 nm). Il valore di aderenza risulta calcolato secondo la formula: √(OD in TSB)+(OD in TSB senza glucosio). I cut-off utilizzati sono: OD≤0.120→batteri non aderenti; OD>0.240→batteri fortemente aderenti; OD>0.120-0.240≤→batteri debolmente aderenti (Christensen et al 1985; 22: 996-1006). I risultati indicano che ceppi MRSA sono significativamente più aderenti rispetto a ceppi MSSA se coltivati in TSB privo di glucosio (p=0.01), mentre, se coltivati in mezzo con glucosio, sia i ceppi MRSA che quelli MSSA risultano avere la stessa capacità ad aderire. Le conclusioni di tali dati sembrano correlare la resistenza alla meticillina ed l’abilità ad aderire alle superfici ed evidenziano il ruolo dell’influenza ambientale su tale abilità. Lo studio quantitativo della produzione di biofilm rappresenta uno strumento di conoscenza necessario per caratterizzare ulteriormente i ceppi responsabili di infezioni polmonari in pazienti CF.

IDENTIFICAZIONE DI CEPPI DIVERSI DI PSEUDOMONAS AERUGINOSA IN PAZIENTI AFFETTI DA FIBROSI CISTICA

Microbiologia Medica 198 (25,7%), mentre il QFT in 1 caso (2,8%). In questo gruppo la percentuale di indeterminati è stata del 14,3% circa per entrambe i test commerciali. Conclusioni. Questi dati preliminari suggeriscono che l’utilizzo di un controllo positivo è cruciale nei pazienti gravemente immunodepressi e, nella nostra esperienza, il TSPOT.TB sembra essere più sensibile in questo gruppo rispetto al QFT.