Human Campylobacter spp. infections in Italy.

PURPOSE: Campylobacter is a frequent cause of enteric infections with common antimicrobial resistance issues. The most recent reports of campylobacteriosis in Italy include data from 2013 to 2016. We aimed to provide national epidemiological and microbiological data on human Campylobacter infections in Italy during the period 2017-2021. METHODS: Data was collected from 19 Hospitals in 13 Italian Regions. Bacterial identification was performed by mass spectrometry. Antibiograms were determined with Etest or Kirby-Bauer (EUCAST criteria). RESULTS: In total, 5419 isolations of Campylobacter spp. were performed. The most common species were C. jejuni (n = 4535, 83.7%), followed by C. coli (n = 732, 13.5%) and C. fetus (n = 34, 0.6%). The mean age of patients was 34.61 years and 57.1% were males. Outpatients accounted for 54% of the cases detected. Campylobacter were isolated from faeces in 97.3% of cases and in 2.7% from blood. C. fetus was mostly isolated from blood (88.2% of cases). We tested for antimicrobial susceptibility 4627 isolates (85.4%). Resistance to ciprofloxacin and tetracyclines was 75.5% and 54.8%, respectively; resistance to erythromycin was 4.8%; clarithromycin 2% and azithromycin 2%. 50% of C. jejuni and C. coli were resistant to ≥ 2 antibiotics. Over the study period, resistance to ciprofloxacin and tetracyclines significantly decreased (p < 0.005), while resistance to macrolides remained stable. CONCLUSION: Campylobacter resistance to fluoroquinolones and tetracyclines in Italy is decreasing but is still high, while macrolides retain good activity.

Trichphyton violaceum and T. soudanese: re-emerging pathogens in Italy, 2005-2013.

Dermatomycoses due to Trichophyton violaceum are described in Mediterranean Countries, North Africa and in the Horn of Africa where T. soudanense is present too, but it was rare until few years ago in Italy. Aim of the present study was to evaluate an Italian multicenter 9 year (2005-2013) experience concerning these re-emerging pathogens. Fifty three fungal strains were sent from clinical laboratories to the Medical Mycology Committee (CoSM)--Italian Association of Clinical Microbiology (AMCLI) for mycological confirmation. Strains were identified as T. violaceum (23) and T. soudanense (30) by phenotypic and genotypic methods. These dermatophytes present epidemiological (high rate of inter-human transmission, high risk among adopted children coming from countries of either the Horn of Africa or Sub-Saharan Africa also in outbreaks of tinea capitis) and clinical peculiarities (reduced alopecia, presence of exudative lesions) confirming the originality of these "imported" dermatophyte infections.

Hepatitis C Virus as a Possible Helper Virus in Human Hepatitis Delta Virus Infection.

Previous studies reported that the hepatitis C virus (HCV) could help disseminate the hepatitis D virus (HDV) in vivo through hepatitis B virus (HBV)-unrelated ways, but with essentially inconclusive results. To try to shed light on this still-debated topic, 146 anti-HCV-positive subjects (of whom 91 HCV/HIV co-infected, and 43 with prior HCV eradication) were screened for anti-HDV antibodies (anti-HD), after careful selection for negativity to any serologic or virologic marker of current or past HBV infection. One single HCV/HIV co-infected patient (0.7%) tested highly positive for anti-HD, but with no positive HDV-RNA. Her husband, in turn, was a HCV/HIV co-infected subject with a previous contact with HBV. While conducting a thorough review of the relevant literature, the authors attempted to exhaustively describe the medical history of both the anti-HD-positive patient and her partner, believing it to be the key to dissecting the possible complex mechanisms of HDV transmission from one subject to another, and speculating that in the present case, it may have been HCV itself that behaved as an HDV helper virus. In conclusion, this preliminary research, while needing further validation in large prospective studies, provided some further evidence of a role of HCV in HDV dissemination in humans.

Microarray technology for yeast identification directly from positive blood cultures. A multicenter Italian experience.

The authors evaluated the performance of the MycArray™ Yeast ID (Myconostica Ltd, UK) assay in the identification of a total of 88 yeast isolates recovered in culture as compared to that obtained through routine methods. The turn-around time for species identification directly from cultures by the MycArray was 6 hours, much quicker than classical methods and all yeasts were correctly identified. In two cases a double identification including Saccharomyces cerevisiae was noted, but it was not confirmed by culture. The results show that MycArray Yeast ID can be a potential tool for rapid detection and identification of Candida species.

Evaluation of the peptide nucleic acid fluorescence in situ hybridisation technology for yeast identification directly from positive blood cultures: an Italian experience.

Fungaemia is an increasing nosocomial pathology. The 'gold standard' for detection of fungaemia is blood culture, but it is time-consuming and its sensitivity for early detection is low. On the other hand, yeasts present different antifungal sensitivity patterns to be quickly detected to allow an effective treatment. The aim of this study was to evaluate the diagnostic performances of PNA-FISH to directly identify yeasts from blood cultures and to compare results with those obtained by culture. A total of 176 blood cultures positive for yeasts at direct Gram stain and 24 negative blood cultures as control collected from 15 Italian hospitals, included in a network coordinated by the Medical Mycology Committee, Italian Society of Clinical Microbiology (AMCLI), were examined both by culture and PNA-FISH technology. Sensitivity of the PNA-FISH technique evaluated for five Candida species was 99.3% and specificity, 100%. Distinguishing which yeast is implicated in fungaemia and whether the infection is caused by multiple species are important for the selection of antifungal therapy. The PNA-FISH technique is a very useful approach because the test discriminates between groups of Candida species with different susceptibility pattern, particularly against azoles and echinocandins, with only a 90-minute turn-around time after the Gram-stain reading.

Multicenter Italian Study on "In Vitro Activities" of Isavuconazole, Voriconazole, Amphotericin B, and Caspofungin for Aspergillus Species: Comparison between SensititreTM YeastOneTM and MIC Test Strip.

In this study the activity of Isavuconazole, Voriconazole, Amphotericin B, and Caspofungin against 224 clinical isolates of Aspergillus spp. originating from seven Italian hospitals, was comparatively evaluated with two commercial antifungal susceptibility tests (AST): SensititreTM YeastOneTM (SYO) and MIC Test Strip. More attention was focused on Isavuconazole activity, given the new introduction of the drug in widely distributed antifungal susceptibilities methods in the clinical microbiology lab. The minimum inhibitory concentrations of antifungal drug that can inhibit the growth of pathogen by 90% (MIC90) for Isavuconazole detected by SYO were 0.5, 1, 0.25, and 2 µg/mL for Aspergillus fumigatus, Aspergillus flavus, Aspergillus terreus, and Aspergillus niger, respectively, whilst they were 0.25, 0.25, 0.5, and 0.75 µg/mL by MIC Test Strip. Essential agreement between the two tested methods for Isavuconazole is 70% for all the species tested, 75.7% for A. fumigatus, 45.2% for A. flavus, 90.6% for A. terreus, and 40% for A. niger. Although the tested strains do not express any phenotypic resistance, MIC results were quite different if tested with microdilution broth or gradient agar method. This is the first Italian multicenter report on Isavuconazole MIC obtained employing the widely used SensititreTM Yeast OneTM (SYO) and MIC Test Strip on clinical isolates of Aspergillus.

Antifungal susceptibility of invasive yeast isolates in Italy: the GISIA3 study in critically ill patients.

BACKGROUND: Yeasts are a common cause of invasive fungal infections in critically ill patients. Antifungal susceptibility testing results of clinically significant fungal strains are of interest to physicians, enabling them to adopt appropriate strategies for empiric and prophylactic therapies. We investigated the antifungal susceptibility of yeasts isolated over a 2-year period from hospitalised patients with invasive yeast infections. METHODS: 638 yeasts were isolated from the blood, central venous catheters and sterile fluids of 578 patients on general and surgical intensive care units and surgical wards. Etest strips and Sensititre panels were used to test the susceptibility of the isolates to amphotericin B, anidulafungin, caspofungin, fluconazole, itraconazole, posaconazole and voriconazole in 13 laboratories centres (LC) and two co-ordinating centres (CC). The Clinical and Laboratory Standards Institute (CLSI) reference broth microdilution method was used at the CCs for comparison. RESULTS: Etest and Sensititre (LC/CC) MIC90 values were, respectively: amphotericin B 0.5/0.38, 1/1 mg/L; anidulafungin 2/1.5 and 1/1 mg/L; caspofungin 1/0.75 and 0.5/0.5 mg/L; fluconazole 12/8 and 16/16 mg/L; itraconazole 1/1.5, 0.5/0.5 mg/L; posaconazole 0.5 mg/L and voriconazole 0.25 mg/L for all. The overall MIC90 values were influenced by the reduced susceptibility of Candida parapsilosis isolates to echinocandins and a reduced or lack of susceptibility of Candida glabrata and Candida krusei to azoles, in particular fluconazole and itraconazole. Comparison of the LC and CC results showed good Essential Agreement (90.3% for Etest and 92.9% for Sensititre), and even higher Categorical Agreement (93.9% for Etest and 96% for Sensititre); differences were observed according to the species, method, and antifungal drug. No cross-resistance between echinocandins and triazoles was detected. CONCLUSIONS: Our data confirm the different antifungal susceptibility patterns among species, and highlight the need to perform antifungal susceptibility testing of clinically relevant yeasts. With the exception of a few species (e.g. C. glabrata for azoles and C. parapsilosis for echinocandins), the findings of our study suggest that two of the most widely used commercial methods (Etest and Sensititre) provide valid and reproducible results.

Interlaboratory evaluation of VITEK2 system and Sensititre YeastOne® for antifungal susceptibility testing of yeasts isolated from blood cultures against four antifungal agents.

An interlaboratory evaluation (seven centers) of VITEK2 System and Sensititre YeastOne® was conducted to test the antifungal susceptibilities of yeasts. The MICs of amphotericin B, fluconazole, flucytosine, and voriconazole were determined for 70 isolates of Candida spp. Our results demonstrated a higher interlaboratory agreement of VITEK 2 System than Sensititre YeastOne©. A good concordance between the two methods was observed for amphotericin B, fluconazole, voriconazole and 5-fluorocytosine (from 81.4% to 88.6%). The study suggests the potential value of the VITEK2 System as a convenient alternative method for testing the susceptibility of yeasts. It also indicates the need for further optimization of MIC endpoint criteria to improve interlaboratory agreement.

Chest CT accuracy in diagnosing COVID-19 during the peak of the Italian epidemic: A retrospective correlation with RT-PCR testing and analysis of discordant cases.

OBJECTIVES: The goal of this study was to assess chest computed tomography (CT) diagnostic accuracy in clinical practice using RT-PCR as standard of reference. METHODS: From March 4th to April 9th 2020, during the peak of the Italian COVID-19 epidemic, we enrolled a series of 773 patients that performed both non-contrast chest CT and RT-PCR with a time interval no longer than a week due to suspected SARS-CoV-2 infection. The diagnostic performance of CT was evaluated according to sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy, considering RT-PCR as the reference standard. An analysis on the patients with discrepant CT scan and RT-PCR result and on the patient with both negative tests was performed. RESULTS: RT-PCR testing showed an overall positive rate of 59.8 %. CT sensitivity, specificity, PPV, NPV, and accuracy for SARS-CoV-2 infection were 90.7 % [95 % IC, 87.7%-93.2%], 78.8 % [95 % IC, 73.8-83.2%], 86.4 % [95 % IC, 76.1 %-88.9 %], 85.1 % [95 % IC, 81.0 %-88.4] and 85.9 % [95 % IC 83.2-88.3%], respectively. Twenty-five/66 (37.6 %) patients with positive CT and negative RT-PCR results and 12/245 (4.9 %) patients with both negative tests were nevertheless judged as positive cases by the clinicians based on clinical and epidemiological criteria and consequently treated. CONCLUSIONS: In our experience, in a context of high pre-test probability, CT scan shows good sensitivity and a consistently higher specificity for the diagnosis of COVID-19 pneumonia than what reported by previous studies, especially when clinical and epidemiological features are taken into account.

Use of an innovative and non-invasive device for virologic sampling of cough aerosols in patients with community and hospital acquired pneumonia: a pilot study.

BACKGROUND: The aetiology of lower respiratory tract infections is challenging to investigate. Despite the wide array of diagnostic tools, invasive techniques, such as bronchoalveolar lavage (BAL), are often required to obtain adequate specimens. PneumoniaCheckTM is a new device that collects aerosol particles from cough, allowing microbiological analyses. Up to now it has been tested only for bacteria detection, but no study has investigated its usefulness for virus identification. METHODS: In this pilot study we included 12 consecutive patients with pneumonia. After testing cough adequacy via a peak flow meter, a sampling with PneumoniaCheckTM was collected and a BAL was performed in each patient. Microbiological analyses for virus identification were performed on each sample and concordance between the two techniques was tested (sensitivity, specificity and positive/negative predictive values), taking BAL results as reference. RESULTS: BAL was considered adequate in 10 patients. Among them, a viral pathogen was identified by PneumoniaCheckTM 6 times, each on different samples, whereas BAL allowed to detect the presence of a virus on 7 patients (14 positivities). Overall, the specificity for PneumoniaCheckTM to detect a virus was 100%, whereas the sensitivity was 66%. When considering only herpes viruses, PneumoniaCheckTM showed a lower sensitivity, detecting a virus in 1/4 of infected patients (25%). CONCLUSIONS: In this pilot study PneumoniaCheckTM showed a good correlation with BAL for non-herpes virologic identification in pneumonia patients, providing excellent specificity. Further studies on larger population are needed to confirm these results and define its place in the panorama of rapid diagnostic tests for lower respiratory tract infections.

Management of antifungal susceptibility testing in Italy: comparative results of 2 nationwide surveys (1999 and 2004) in 102 Italian hospitals.

The purpose of this study was to verify the standard procedures and minimum level of knowledge of Italian public laboratories involved in the management of antifungal susceptibility testing (AST). Two nationwide surveys were performed in 1999 and 2004. One hundred and two Italian hospitals located in 85 provincial capitals (82.5%) participated to these surveys. In 1999, 28 (27.5%) laboratories versus 16 (15.7%) in 2004 stated that they did not perform any susceptibility testing. Some discrepancies observed in the survey confirm that AST is difficult to be correctly managed, and that it can be performed only in very well-trained centers. The great variability of the results of MIC determination and clinical interpretation underlines the urgent need to improve knowledge about indications, method choice, and interpretative criteria for AST both for clinical microbiologists and clinicians.

From soil to blood: first human case of Sphingobacterium hotanense bacteraemia.

This report describes a case of Sphingobacterium hotanense bacteraemia in a patient scratched by a rooster on the right arm. Diagnostic, clinical and therapeutic features are discussed. To the best of our knowledge, this is the first case of Sphingobacterium hotanense bacteremia reported in the medical literature.

Arthrographis kalrae arthritis: a new case report.

To date, only 11 cases of infection by Arthrographis kalrae have been described. According to the literature, we report a second case of arthritis caused by this mycete after a penetrating wound successfully treated with voriconazole before arthroscopic knee washout for six weeks.

In vitro fluconazole susceptibility of 1565 clinical isolates of Candida species evaluated by the disk diffusion method performed using NCCLS M44-A guidelines.

We determined the in vitro activity of fluconazole against 1565 clinical Candida spp. isolates collected from different specimens of non-AIDS outpatients and inpatients in 3 different regions of Italy. Susceptibility testing was performed by agar disk diffusion using the NCCLS document M44-A guidelines. Candida albicans was the most frequently isolated yeast (68%) followed by C. glabrata (15%), C. tropicalis (5%), C. parapsilosis (5%), and C. krusei (5%). Other yeasts represented 4% of all isolates. Of the 1565 isolates tested, 1449 (92.6%) were susceptible (S) to fluconazole, 43 (2.7%) were susceptible dose-dependent (S-DD) and 73 (4.7%) were resistant (R). Almost all (98.2%) of the C. albicans isolates were classified as S or S-DD. Despite its widespread use, fluconazole displayed good activity against the isolates we tested, and the disk diffusion method was confirmed as a reliable approach to the evaluation of in vitro susceptibility of yeasts to this antimycotic agent.

Antifungal resistance does not necessarily affect Candida glabrata fitness.

Although there has been an overall good coverage of Candida glabrata infections by the echinocandins, emergence of antifungal resistance during therapy has been reported. We investigated, by using an invertebrate host model, the fitness of sequential C. glabrata isolates with different echinocandins susceptibility patterns. The studied strains were isolated from a case of recurrent fungemia with a fatal outcome due to C. glabrata that developed cross-resistance to echinocandins during caspofungin therapy. The sequential strains isolated post-therapy showed a S663P mutation in the Fks2p hot spot 1. In vivo study in the invertebrate host Galleria mellonella did not suggest a fitness cost related to the acquired antifungal resistance, the three isolates displayed a similar rate of killing (P  =  0.54). We observed a clear correlation between emergence of antifungal resistance and persistence of the causal agent, probably aided by the unchanged fitness and unresponsiveness in vivo to the adopted therapy.

Stenotrophomonas maltophilia: an emerging pathogen in dialysis units.

Infection is an important cause of morbidity and mortality among patients with end stage renal disease. Stenotrophomonas maltophilia is an unusual yet emerging pathogen in dialysis units. We performed a systematic PubMed/Medline and Scopus review of peer-reviewed English papers on S. maltophilia infections among patients undergoing chronic dialysis, with regard to vascular accesses, systemic infections and environment contaminations. Moreover, we suggest a treatment algorithm to preserve the patient and the permanent dialysis catheters.