Giovanni Orengo

Colistin and rifampicin in the treatment of multidrug-resistant Acinetobacter baumannii infections

OBJECTIVES The increased incidence of nosocomial infections by multidrug-resistant organisms has motivated the re-introduction of colistin in combination with other antimicrobials in the treatment of infections. We describe the clinical and microbiological outcomes of patients infected with multidrug-resistant Acinetobacter baumannii who were treated with a combination of colistin and rifampicin. PATIENTS AND METHODS Critically ill patients with pneumonia and bacteraemia caused by A. baumannii resistant to all antibiotics except colistin in medical and surgical intensive care units were enrolled. Clinical and microbiological responses and safety were evaluated. RESULTS Twenty-nine patients (47 +/- 14 years and APACHE II score 17.03 +/- 3.68), of whom 19 were cases of nosocomial pneumonia and 10 were cases of bacteraemia, were treated with intravenous colistin sulphomethate sodium (2 million IU three times a day) in addition to intravenous rifampicin (10 mg/kg every 12 h). All A. baumannii isolates were susceptible to colistin. The mean duration of treatment with intravenous colistin and rifampicin was 17.7 (+/-10.4) days (range 7-36). Clinical and microbiological responses were observed in 22 of 29 cases (76%) and the overall infection-related mortality was 21% (6/29). Three of the 29 evaluated patients (10%) developed nephrotoxicity when treated with colistin, all of whom had previous renal failure. No cases of renal failure were observed among patients with normal baseline renal function. No neurotoxicity was noted. CONCLUSIONS Colistin and rifampicin appears to be an effective and safe combination therapy for severe infections due to multidrug-resistant A. baumannii.

Effect of seasonal exposure to pollen on specific bronchial sensitivity in allergic patients

Bronchial provocation tests with aerosol of birch extract were performed before and after pollen season in 11 sensitized subjects. Changes of metacholine bronchial responsiveness and serum-specific IgE level were also assessed. In five patients who did not take steroids to control their symptoms, both early and late asthmatic responses to inhaled allergen were enhanced after season, whereas IgE serum level, but not methacholine sensitivity, was significantly increased. In six patients who needed steroids, neither responses to allergen nor IgE serum level and methacholine sensitivity were significantly changed after season. For the whole group, the increase in immediate bronchial sensitivity to allergen was positively correlated with the increase in specific IgE antibodies. We conclude that seasonal exposure to pollen has, in sensitized patients, a priming effect on bronchial mucosa that may be blunted by steroid treatment. The increased production of specific IgE antibodies appears to be an important mechanism for this priming effect.

Adherence to international and national recommendations for the prevention of surgical site infections in Italy: Results from an observational prospective study in elective surgery

BACKGROUND An observational prospective study of the perioperative procedures for prevention of surgical site infections (SSIs) was carried out in a tertiary referral teaching hospital in Liguria, Italy, to evaluate their adherence to international and national standards. METHODS A 1-month survey was performed in all surgical departments, monitored by turns by trained survey teams. Data regarding presurgical patient preparation and intraoperative infection control practices were collected. RESULTS A total of 717 elective interventions were actively monitored in 703 patients who underwent surgery. Hair-shaving was performed mainly using a razor (92%) by the nurses (72.8%) on the day before the operation (83.5%). All of the patients showered, either with a common detergent (87%) or with an antiseptic solution (13%). Antimicrobial prophylaxis was administered properly in 75.7% of the patients at induction of anaesthesia; however, according to current Italian guidelines, inappropriate prophylaxis was provided in 55.2% patients. Appropriate antisepsis of the incision area was done in 97.4% of the operations, and nearly 90% of the interventions lasted less than the respective 75th percentile. The doors of the operating theatres were mostly open during the duration of the operation in 36.3% of the cases. CONCLUSIONS This review of infection control policies identified significant opportunities for improving the safety and the quality of routine surgical practice.

Late asthmatic reaction to perennial and seasonal allergens

Twelve patients with asthma sensitized to Dermatophagoides pteronyssinus and Parietaria judaica were studied. Patients were challenged before (winter), during (summer), and after (autumn) Parietaria-pollen season. Early asthmatic reaction was positive for both allergens, and the provocative dose causing a 15% decrease of FEV1 was similar in all seasons. The provocative dose of methacholine causing a 15% decrease of FEV1 and specific IgEs for both allergens were also not significantly different throughout the time of study. Late asthmatic reaction (LAR) to Dermatophagoides occurred in eight of 12 patients in winter, in six of nine in summer, and in five of six patients in autumn. The severity of LAR, expressed as the maximum fall of FEV1 3 to 8 hours after challenge, was not significantly different between seasons. LAR to Parietaria occurred in only one of 12 patients in winter, in six of 11 in summer, and in one of six patients in autumn. In summer, LAR to Parietaria was significantly more severe than in winter. In both winter and autumn, but not in summer, LAR to Dermatophagoides was significantly more severe than to Parietaria. We conclude that LAR is allergen specific, and natural exposure has a priming effect on LAR.

Identification of a New Delhi metallo-β-lactamase-4 (NDM-4)-producing Escherichia coli in Italy

BackgroundDuring June-July 2012, six imipenem-resistant Escherichia coli isolates were isolated from two patients hospitalized in a ward of one large tertiary-care hospital in Genoa, Italy. Genetic features associated with blaNDM-4 gene were investigated.ResultsThe isolates exhibited the same PFGE profile and a multidrug-resistant (MDR) phenotype to aminoglycosides, fluoroquinolones, and β-lactams. The strains produced the NDM-4 carbapenemase and the blaNDM-4 gene was part of the variable region of a class 1 integron. MLST analysis revealed that all isolates belonged to sequence type 405 (ST405).ConclusionsThis is the first report on the emergence of an MDR strain of E.coli producing the NDM-4 MBL in Italy.

Latent Tuberculosis Infection among a Large Cohort of Medical Students at a Teaching Hospital in Italy

The surveillance of latent tuberculosis infection (LTBI) in both healthcare workers and healthcare students is considered fundamental for tuberculosis (TB) prevention. The aim of the present study was to estimate LTBI prevalence and evaluate potential risk-factors associated with this condition in a large cohort of medical students in Italy. In a cross-sectional study, performed between March and December 2012, 1511 eligible subjects attending the Medical School of the University of Genoa, trained at the IRCCS San Martino-IST Teaching Hospital of Genoa, were actively called to undergo the tuberculin skin test (TST). All the TST positive cases were confirmed with an interferon-gamma release assay (IGRA). A standardized questionnaire was collected for multivariate risk analysis. A total of 1302 (86.2%) students underwent TST testing and completed the questionnaire. Eleven subjects (0.8%) resulted TST positive and LTBI diagnosis was confirmed in 2 (0.1%) cases. Professional exposure to active TB patients (OR 21.7, 95% CI 2.9–160.2; P value 0.003) and previous BCG immunization (OR 28.3, 95% CI 3.0–265.1; P value 0.003) are independently associated with TST positivity. Despite the low prevalence of LTBI among Italian medical students, an occupational risk of TB infection still exists in countries with low circulation of Mycobacterium tuberculosis.

Survey of allergic respiratory symptoms in grain terminal workers in the Port of Genoa

SummaryFifty workers from two grain elevator terminals were examined to evaluate the prevalence of respiratory symptoms and their relationship with grain dust exposure.Fifty per cent of subjects complained of respiratory symptoms (rhinitis, asthma, chronic cough and dyspnea on exertion). In 34% of the workers the ventilatory function revealed some abnormalities (slight or moderate obstruction).Twenty-two (44%) showed a positive cutaneous reaction to one or more of the allergens tested, mostly towardsDermatophagoides and storage mites. The self-measurement of PEF over 14 days in 27 workers, showed significant differences between symptomatic and asymptomatic subjects. In particular, the results obtained from the cutaneous reactions could suggest a bronchial hypereactivity, worsened by the working exposure to dusts. The monitoring of PEF appears to be a simple and useful method for investigating the relationship between respiratory symptoms and the working environment.