New Microbiologica最新文献

Bacteria biofilm consists of microorganisms, accounting for 5-35% of the biofilm volume, and of the extracellular matrix (65-95%), made of water (97%), proteins (2%), polysaccharides (1-2%) and nucleic acids (DNA/RNA, both <1%). The physiology of bacteria in the biofilms entails adaptive changes with expression of genes which are different from those translated in the planktonic state. While most of our applied knowledge on bacterial biology stems from the study in the planktonic state, an increasing interest is currently paid to bacterial behaviour as biofilm generators, as it is estimated that 65% of all bacterial infections are associated with bacterial biofilms. Infections of both upper and lower airways, bacterial endocarditis, chronic otitis media, urinary tract infections, periodontitis, ocular infections and chronic wound infections (including diabetic foot ulcer) are all associated with biofilm formation. The role of biofilm is also relevant in case of infections taking place on abiotic surfaces, as in the case of infections occurring on prostheses and several other medical devices. Here, we review current knowledge on biofilm formation and its impact on human infections, discussing recent means for its inhibition, with particular emphasis on an interesting anti-biofilm activity exerted by exopolysaccharides derived from marine strains of Bacillus licheniformis.

High-resolution CT-scan (HRCT) plays a major role in the diagnosis of Nontuberculous mycobacteria lung disease (NTM-LD), but its role in follow-up is controversial. Our aim was first to conceive a radiological score able to quantify the severity of pulmonary involvement by NTM infection and, second, to check its association with the NTM-LD clinical burden. We also intended, if possible, to verify the potential influence of NTM specific treatment on the radiological score. We retrospectively collected the clinical, microbiological and radiological data of all patients who were admitted to our hospital from 1 January 2012 to 1 January 2020 with a confirmed diagnosis of NTM-LD. A radiological score was applied to evaluate lung involvement on HRCT at diagnosis and at 6-18 months follow-up. Twenty-eight patients with NTM-LD performed follow-up HRCT. No association was found between radiological and clinical score (Spearman R -0.05, 95%CI -0.41 to 0.33). Repeated measures analysis showed a significant increase in radiological score over time (change 1.11, 95%CI 0.10 to 2.11; p-value 0.032), while Mann-Whitney test did not show any difference between treated and untreated patients (p value 0.922). Further studies are needed to assess the usefulness of routine radiological follow-up in patients with NTM-LD.

This study provides an update on hepatitis C virus (HCV) estimates across Italy up to January 2021. A mathematical probabilistic modelling approach, including a Markov chain for liver disease progression, was used to estimate current HCV viraemic burden. Prevalence was defined by geographic area using an estimated annual historical HCV incidence by age, treatment, and migration rate from the Italian National database (ISTAT). Viraemic infection was estimated for the main HCV transmission routes by stages F0-F3 (patients without liver cirrhosis, i.e., potentially asymptomatic liver disease) and F4 (patients with liver cirrhosis, i.e., potentially symptomatic liver disease). By January 2021, we estimated that there were 398,610 individuals in Italy with active HCV infection (prevalence of 0.66%; 95% CI: 0.66-0.67), of which 287,730 (0.48%; 95% CI: 0.46-0.59%) were stage F0-F3. Prevalence values for all individuals with active HCV infection were: North 0.54% (95% CI: 0.53-0.54%), Central 0.88% (95% CI: 0.87-0.89%), South 0.72% (95% CI: 0.71-0.73%), and the Isles 0.67% (95% CI: 0.66-0.68%). The population at risk for previous/current drug injection accounted for 48.6% of all individuals with active HCV infection. A modelling approach such as this to estimate and update the prevalence of active HCV infection could be a useful methodology for the evaluation of healthcare policies related to HCV elimination plans.

Fungemia is a life-threatening condition associated with high mortality; the most frequently isolated genus is Candida. Candida glabrata is of particular concern because of its increasing resistance to azoles. We evaluated common lab tests accessible by almost all healthcare professionals to estimate the post-test probability of recovery of C. glabrata from a blood culture collected by venipuncture, positive for fungi identified by microscopic examination. Patients with blood cultures positive for C. glabrata had significantly higher median values of serum creatinine (P=0.006), and a value of ≥1.45 mg/dL was the best cut-off in discriminating C. glabrata from other Candida spp., with 0.67 [95% Confidence Interval (CI): 0.49-0.85] sensitivity and 0.75 (95% CI: 0.66-0.84) specificity; Youden's J statistic: 0.42. The receiver operator characteristic curve analysis showed an area under the curve of 0.718 (95% CI: 0.603-0.833); P=0.001. Therefore, given a pre-test probability of 24% and applying the Bayes' theorem, the post-test probability of C. glabrata fungemia with creatinine values ≥1.45 mg/dL increased to 45.8%. In conclusion, we showed how the probability of recovery of C. glabrata from blood cultures collected by venipuncture and positive for fungi can be better estimated using concurrent creatinine values.

Genital disorders, such as vulvo-vaginal candidiasis (VVC), bacterial vaginosis (BV), and aerobic vaginitis (AV), are very common among fertile women and negatively impact their reproductive and relational life. Vaginal culture can help in the diagnostic workflow of these conditions. Recently, culture-based techniques have taken advantages of up-front specimen processing units, which also include a digital imaging system to record images of plates at programmable time points. In this proof-of-concept study, we assessed the characteristics of digital plate images of vaginal swabs plated by WASPLab system into different media, in order to detect microbial growth morphotypes specific for each genital disorder. A total of 104 vaginal specimens were included: 62 cases of normal lactobacilli-dominated flora, 12 of BV, 16 of VVC, and 14 of AV were analysed. Vaginal specimens were plated by WASPLab system into different chromogenic media and blood agar plates. Plate images were taken automatically by the digital imager at 38 h post-inoculation. We found that each genital condition was characterized by specific morphotypes in terms of microbial growth and colony colour, thus allowing the potential use of artificial intelligence not only to assess the presence of specific microbial genera/species but also to 'categorize' peculiar clinical conditions.

In this study, we tested the performance of the Sysmex UF-5000 system to detect yeast-like cell (YLC) counting to screen for candiduria. Urine samples were screened for leukocyte and yeast amount by flow cytometry and results were compared with fungal culture results. A total of 56,749 urine samples were enrolled in this study. Urine culture and urinalysis of YLC data were used to evaluate the performance of YLC in diagnosing candiduria. Different cut-off values (YLC. 5, 10, 20, 50, 100/μl) were evaluated. Youden index was used to determine the ideal cut-off value, and the highest was 0.95 with 5 YLC/μl. When the cut-off value for YLC is 5 cells/μl, 95.15% of the samples were "negative" with flow cytometry and culture (NPV:100%). In conclusion, detection of YLC by flow cytometer (Sysmex UF-5000) can be a rapid alternative method to exclude candiduria prior to urine culture.

Human bocavirus 1 (HBoV1) is an important pathogen causing lower respiratory tract infection. The VP1 unique region (VP1u), consisting of 129 amino acids at the N-terminus of the HBoV1 structural protein VP1, is an important component of virus infection. Bioinformatics analysis predicted that HBoV1 VP1u exhibits two bipartite nuclear localization signals (NLS) and contains four basic regions (BRs). The two potential bipartite NLSs consist of BR2 and 3 and BR3 and 4, respectively. In this study, we inserted the truncated vp1u sequences into a double EGFP fusion expression vector and confirmed the vimentin (VIM)-HBoV1 VP1u interaction by mass spectrometry and immunoprecipitation. The results of our IFA analysis showed that all four VP1u BRs displayed strong nuclear transport functions. We further demonstrated that VP1u interacted with VIM and that they colocalized in the cytoplasm. VP1u expression in the cells enhanced the VIM expression, and the VP1u expression also increased upon VIM overexpression, although it was not affected by VIM knockdown. Upon VIM overexpression, VP1u nucleation was significantly enhanced, but was inhibited by VIM downregulation. These results indicate that the VP1u-VIM interaction could be involved in the nuclear transport of VP1u. VP1u nucleation might further affect HBoV1 replication and infection. This study could potentially help clarify the function of VP1u by further revealing the HBoV1 nuclear transport mechanism and provide a new approach for elucidating the molecular mechanism of HBoV1 replication.

The aim of this study was to describe the prevalence and epidemiology distribution of K. pneumoniae isolated at University Hospital of Campania "Luigi Vanvitelli," including the susceptibility evolution profile. Data on resistant phenotype strains, such as extended-spectrum-β-lactamase (ESBL) producers and carbapenem-resistant K. pneumoniae (CRE) isolates, were also reported. K. pneumoniae strains were collected at the Complex Operative Unit (UOC) of Virology and Microbiology from different colonization and infection sites from January 2016 to December 2020. The highest rates of isolation were in urinary samples and in respiratory and wound swabs. Antibiotics susceptibility patterns showed more than 50% of the isolates resistant to cephalosporins, fluoroquinolones and penicillin. On the other hand, from 20% to 40% of K. pneumoniae strains were resistant to carbapenems and aminoglycosides. Based on our analysis, fosfomycin, ceftazidime/avibactam and ceftolozane/tazobactam are still therapeutic alternatives. Data analysis on carbapenem class evolution in 2016-2020 showed a significant increase in resistance rates (p<0.05). Increased rates in CRE and ESBL producing K. pneumoniae since 2017 were reported. Providing information on clinical characteristics and epidemiology data on contemporary K. pneumoniae evolution could help mitigate the spread of these isolates in our hospital and avert the endemic levels that have been observed in Southern Italy and in other European countries.

Point-of-care rapid testing is one of the strategies to increase HIV screening. We present data on over 14 years of the "EASY Test Program", an ongoing cross-sectional collaborative project that provides free and anonymous rapid HIV testing in the metropolitan city of Milan, Italy. Overall, 22,186 HIV tests were performed, with a 0.52% prevalence of HIV infection; 100% of those diagnosed with HIV were linked to care. The "EASY Test Program" is an appropriate test-and-treat strategy, allowing a fast HIV assessment (24 hours). Motivated clinicians, in partnership with community associations, can perform an easy HIV screening out of hospitals in alternative settings, among individuals who in the majority of cases had never tested for HIV, ultimately providing an effective linkage to care.

Diagnosis and management of infectious diseases (ID) at the emergency department (ED) are challenging due to the peculiar setting and the available diagnostic tools. The involvement of an ID consultant has been described to improve clinical outcomes and antimicrobial stewardship (AMS) programs. An online survey was sent to 100 Italian Departments of Infectious Diseases affiliated with the Italian Society of Infectious Diseases and Tropical Medicine (SIMIT). The primary objective of our study was to describe the characteristics of ID services in Italian EDs to identify possible challenges and shortcomings and provide tips to improve the management of patients. Secondary objectives included the evaluation of diagnostic capability and the management of patients with suspected or confirmed ID. Seventy-six out of the 100 SIMIT centers, 32 (42.1%) of which were teaching hospitals, answered the survey. In 62 (82.7%) centers, consultations were performed by the IDs specialist on call. In 29 (38.2%) centers, there was a formal AMS program, and 32 (42.7%) had protocols for antibiotic use in the ED. Microbiological tests to be performed before starting antibiotic treatment in the ED were clearly defined in 44 (57.9%) hospitals. This survey highlighted several challenges in the current organization of ID consultations in Italian EDs.