Performance analysis of two immunochromatographic assays for the diagnosis of rotavirus infection.

Group A rotaviruses (RVAs) are the primary cause of acute gastroenteritis (AGE) in young children worldwide. Several commercial tests including latex agglutination, enzyme-linked assays (ELISA) and immunochromatographic tests (ICT) have been developed for the diagnosis of RVA infection. In the present study, the performance of two commercially available one-step chromatographic immunoassays, CerTest Rotavirus+Adenovirus (Biotec S.L, Zaragoza, Spain) and Vikia Rota-Adeno (bioMerieux SA, Lyon, France) were retrospectively evaluated using Real-time PCR as reference test. Re-testing by Real-time PCR of 2096 stool samples of children hospitalized with AGE previously screened by ICTs (1467 by CerTest and 629 by Vikia) allowed to calculate higher sensitivity for Vikia (94% vs 85% of CerTest) and higher specificity for CerTest (93% vs 89% of Vikia). Accordingly, higher Positive Predictive Values (87% vs 78%) and Positive Likelihood Ratios (12.32 vs 8.8) were found for CerTest and lower Negative Predictive Values (91% vs 97%) and Negative Likelihood Ratios (0.16 vs 0.06) for Vikia. However, both CerTest and Vikia showed a substantial agreement (κ=0.79) with the Real-time PCR. A correlation between false negative results by ICTs and high Cycle Threshold values of Real-time PCR, indicative of low viral load, was observed. False positive results by the two ICT assays were not related to Norovirus, Adenovirus or Astrovirus infections, therefore the risk of cross-reactions was excluded. Both CerTest and VIKIA were able to detect the wide range of RVA genotypes circulating over the study period (including G1P[8], G2P[4], G3, G4, G9 and G12P[8]). The results of the present study showed a satisfactory efficacy of the two diagnostic tests analyzed.

Introduction and prolonged circulation of G12 rotaviruses in Sicily.

Genotype G12 strains are now considered to be the sixth most prevalent human rotaviruses worldwide. In two Sicilian cities, Palermo and Messina, surveillance of rotavirus circulation performed since 1985 and 2009, respectively, did not detect G12 strains until 2012. From 2012 to 2014 rotavirus infection was detected in 29·7% of 1647 stool samples collected from children admitted for acute gastroenteritis to three Sicilian hospitals in Palermo, Messina and Ragusa. In 2012, G12P[8] was first detected in Palermo and then in Messina where it represented the second most frequent genotype (20% prevalence) after G1P[8]. Thereafter, G12 strains continued to circulate in Sicily, showing a marked prevalence in Ragusa (27·8%) in 2013 and in Palermo (21%) and Messina (16·6%) in 2014. All but one of the Sicilian G12 strains carried a P[8] VP4 genotype, whereas the single non-P[8] rotavirus strain was genotyped as G12P[9]. Phylogenetic analysis of the VP7 and VP4 sequences allowed distinction of several genetic lineages and separation of the G12P[8] strains into three cluster combinations. These findings indicate independent introductions of G12 rotavirus strains in Sicily in recent years.

SIMIFF study: Italian fungal registry of mold infections in hematological and non-hematological patients.

PURPOSE: We compared the risk factors, the diagnostic tools and the outcome of filamentous fungal infections (FFIs) in hematological patients (HAEs) and non-hematological patients (non-HAEs). METHODS: Prospective surveillance (2009-2011) of proven and probable FFIs was implemented in 23 Italian hospitals. RESULTS: Out of 232 FFIs, 113 occurred in HAEs and 119 in non-HAEs. The most frequent infection was invasive aspergillosis (76.1 % for HAEs, 56.3 % for non-HAEs), and the localization was principally pulmonary (83.2 % for HAEs, 74.8 % for non-HAEs). Neutropenia was a risk factor for 89.4 % HAEs; the main underlying condition was corticosteroid treatment (52.9 %) for non-HAEs. The distribution of proven and probable FFIs was different in the two groups: proven FFIs occurred more frequently in non-HAEs, whereas probable FFIs were correlated with the HAEs. The sensitivity of the galactomannan assay was higher for HAEs than for non-HAEs (95.3 vs. 48.1 %). The overall mortality rate was 44.2 % among the HAEs and 35.3 % among the non-HAEs. The etiology influenced the patient outcomes: mucormycosis was associated with a high mortality rate (57.1 % for HAEs, 77.8 % for non-HAEs). CONCLUSIONS: The epidemiological and clinical data for FFIs were not identical in the HAEs and non-HAEs. The differences should be considered to improve the management of FFIs according to the patients' setting.

Ongoing spread of colistin-resistant Klebsiella pneumoniae in different wards of an acute general hospital, Italy, June to December 2011.

We describe polyclonal spread of colistin-resistant Klebsiella pneumoniae in an acute general hospital in Italy. Between June and December 2011, 58 colistin-resistant K. pneumoniae isolates were recovered from 28 patients admitted to different wards, but mainly in the intensive care units. All isolates were tested for drug susceptibility and the presence of beta-lactamase (bla) genes. Clonality was investigated by repetitive extragenic palindromic (rep)-PCR and multilocus sequence typing (MLST). Fifty-two isolates had minimum inhibitory concentrations (MICs) for colistin of 6-128 mg/L, carried bla(KPC3) and were attributed to sequence type ST258. The remaining six isolates were susceptible to carbapenems, exhibited MICs for colistin of 3-32 mg/L, and belonged to two different types, ST15 and ST273. Rep-PCR included all isolates in three clusters, one containing all ST258 KPC-3-producing isolates and two containing ST15 and ST273 isolates.Cross-transmission containment measures and intensification of staff and environmental hygiene could not stop the outbreak. Selective pressure and horizontal transmission probably contributed to emergence and spread of three different strains of colistin-resistant K. pneumoniae in the hospital. Strict implementation of the above measures and a wider awareness of the antimicrobial resistance threat are crucial to preserve the last therapeutic options of the multidrug-resistant Gram-negative infections.

Molecular characterisation and clonal analysis of group A streptococci causing pharyngitis among paediatric patients in Palermo, Italy.

Group A streptococci (n = 123), isolated consecutively from paediatric patients with pharyngitis from Palermo, Italy, were analysed. The emm and sof genes were sequenced, the presence of the speA and speC genes was investigated, and the macrolide resistance phenotypes and genotypes were determined. A limited number of emm/sof genotypes was found, and the most prevalent types were different from those found in a previous study from Rome. Macrolide resistance was found in the most prevalent clones, suggesting that the spread of mobile antibiotic resistance genes among the fittest clones in the community was the main mechanism influencing macrolide resistance rates in different emm types.