Vertebral osteomyelitis due to Lactobacillus paracasei in a diabetic patient. A case report and literature review.

Staphylococci are the most frequent cause of vertebral osteomyelitis, but infections due to unusual pathogens are also reported. We describe a rare case of spondylodiscitis due to Lactobacillus paracasei. A 74-year-old diabetic male was evaluated for fever and back pain. Blood cultures and vertebral biopsy were positive for Lactobacillus paracasei. He often took laxatives and probiotics for chronic constipation. After target treatment the patient improved but he died for a heart attack two months after the end of the treatment. Although Lactobacillus paracasei is usually not pathogenic, sepsis is described in immunocompromised patients while vertebral osteomyelitis is rare.

Untargeted Metagenomic Investigation of the Airway Microbiome of Cystic Fibrosis Patients with Moderate-Severe Lung Disease.

Although the cystic fibrosis (CF) lung microbiota has been characterized in several studies, little is still known about the temporal changes occurring at the whole microbiome level using untargeted metagenomic analysis. The aim of this study was to investigate the taxonomic and functional temporal dynamics of the lower airway microbiome in a cohort of CF patients. Multiple sputum samples were collected over 15 months from 22 patients with advanced lung disease regularly attending three Italian CF Centers, given a total of 79 samples. DNA extracted from samples was subjected to shotgun metagenomic sequencing allowing both strain-level taxonomic profiling and assessment of the functional metagenomic repertoire. High inter-patient taxonomic heterogeneity was found with short-term compositional changes across clinical status. Each patient exhibited distinct sputum microbial communities at the taxonomic level, and strain-specific colonization of both traditional and atypical CF pathogens. A large core set of genes, including antibiotic resistance genes, were shared across patients despite observed differences in clinical status, and consistently detected in the lung microbiome of all subjects independently from known antibiotic exposure. In conclusion, an overall stability in the microbiome-associated genes was found despite taxonomic fluctuations of the communities.

A novel colistin adjuvant identified by virtual screening for ArnT inhibitors.

BACKGROUND: Colistin is a last-resort treatment option for many MDR Gram-negative bacteria. The covalent addition of l-aminoarabinose to the lipid A moiety of LPS is the main colistin resistance mechanism in the human pathogen Pseudomonas aeruginosa. OBJECTIVES: Identification (by in silico screening of a chemical library) of potential inhibitors of ArnT, which catalyses the last committed step of lipid A aminoarabinosylation, and their validation in vitro as colistin adjuvants. METHODS: The available ArnT crystal structure was used for a docking-based virtual screening of an in-house library of natural products. The resulting putative ArnT inhibitors were tested in growth inhibition assays using a reference colistin-resistant P. aeruginosa strain. The most promising compound was further characterized for its range of activity, specificity and cytotoxicity. Additionally, the effect of the compound on lipid A aminoarabinosylation was verified by MS analyses of lipid A. RESULTS: A putative ArnT inhibitor (BBN149) was discovered by molecular docking and demonstrated to specifically potentiate colistin activity in colistin-resistant P. aeruginosa isolates, without relevant effect on colistin-susceptible strains. BBN149 also showed adjuvant activity against colistin-resistant Klebsiella pneumoniae and low toxicity to bronchial epithelial cells. Lipid A aminoarabinosylation was reduced in BBN149-treated cells, although only partially. CONCLUSIONS: This study demonstrates that in silico screening targeting ArnT can successfully identify inhibitors of colistin resistance and provides a promising lead compound for the development of colistin adjuvants for the treatment of MDR bacterial infections.

Airway microenvironment alterations and pathogen growth in cystic fibrosis.

Cystic Fibrosis Transmembrane Regulator (CFTR) dysfunction is associated with epithelial cell vulnerability and with dysregulation of the local inflammatory responses resulting in excessive airway neutrophilic inflammation and pathogen growth. In combination with impaired mucociliary clearance, and dysregulation of defense function, bacterial infection follows with eventual airway damage and remodeling. Because of these inherent vulnerabilities, viral infections are also more severe and prolonged and appear to render the airway even more prone to bacterial infection. Airway acidity, deficient nitric oxide production and increased iron concentrations, further enhance the airway milieu's susceptibility to infection. Novel diagnostic techniques of the airway microbiome elucidate the coexistence of an array of non-virulent taxa beyond the recognized virulent organisms, predominantly Pseudomonas aeruginosa. The complex interplay between these two bacterial populations, including upregulation of virulence genes and utilization of mucin as a nutrient source, modulates the action of pathogens, modifies the CF airway milieu and contributes to the processes leading to airway derangement. The review provides an update on recent advances of the complex mechanisms that render the CF airway vulnerable to inflammation, infection and ultimately structural damage, the key pathogenetic elements of CF. The recent contributions on CF pathogenesis will hopefully help in identifying new prophylactic measures and therapeutic targets for this highly destructive disorder.

Increased expression of ATP12A proton pump in cystic fibrosis airways.

Proton secretion mediated by ATP12A protein on the surface of the airway epithelium may contribute to cystic fibrosis (CF) lung disease by favoring bacterial infection and airway obstruction. We studied ATP12A in fresh bronchial samples and in cultured epithelial cells. In vivo, ATP12A expression was found almost exclusively at the apical side of nonciliated cells of airway epithelium and in submucosal glands, with much higher expression in CF samples. This could be due to bacterial infection and inflammation, since treating cultured cells with bacterial supernatants or with IL-4 (a cytokine that induces goblet cell hyperplasia) increased the expression of ATP12A in nonciliated cells. This observation was associated with upregulation and translocation of ATP1B1 protein from the basal to apical epithelial side, where it colocalizes with ATP12A. ATP12A function was evaluated by measuring the pH of the apical fluid in cultured epithelia. Under resting conditions, CF epithelia showed more acidic values. This abnormality was minimized by inhibiting ATP12A with ouabain. Following treatment with IL-4, ATP12A function was markedly increased, as indicated by strong acidification occurring under bicarbonate-free conditions. Our study reveals potentially novel aspects of ATP12A and remarks its importance as a possible therapeutic target in CF and other respiratory diseases.

In vitro activity of ceftaroline and ceftobiprole against methicillin-resistant Staphylococcus aureus with decreased susceptibility to vancomycin isolated in paediatric patients.

Minimal inhibitory concentrations (MIC, mg/l) of ceftaroline and ceftobiprole were evaluated over 70 methicillin-resistant Staphylococcus aureus (MRSA) strains with vancomycin MIC ≥1 isolated in a paediatric hospital. The proportion of non-wild-type strains (MIC > epidemiological cut off) was 18% for ceftobiprole and 64% for ceftaroline. Only 1.4% of strains was resistant to ceftobiprole, and none to ceftaroline. These results are worrisome, since show the presence of non-negligible proportions of MRSA strains with high MIC values for ceftaroline and ceftobiprole in a setting where both drugs were never used.

A Different Microbiome Gene Repertoire in the Airways of Cystic Fibrosis Patients with Severe Lung Disease.

In recent years, next-generation sequencing (NGS) was employed to decipher the structure and composition of the microbiota of the airways in cystic fibrosis (CF) patients. However, little is still known about the overall gene functions harbored by the resident microbial populations and which specific genes are associated with various stages of CF lung disease. In the present study, we aimed to identify the microbial gene repertoire of CF microbiota in twelve patients with severe and normal/mild lung disease by performing sputum shotgun metagenome sequencing. The abundance of metabolic pathways encoded by microbes inhabiting CF airways was reconstructed from the metagenome. We identified a set of metabolic pathways differently distributed in patients with different pulmonary function; namely, pathways related to bacterial chemotaxis and flagellar assembly, as well as genes encoding efflux-mediated antibiotic resistance mechanisms and virulence-related genes. The results indicated that the microbiome of CF patients with low pulmonary function is enriched in virulence-related genes and in genes encoding efflux-mediated antibiotic resistance mechanisms. Overall, the microbiome of severely affected adults with CF seems to encode different mechanisms for the facilitation of microbial colonization and persistence in the lung, consistent with the characteristics of multidrug-resistant microbial communities that are commonly observed in patients with severe lung disease.

TM6SF2 E167K variant predicts severe liver fibrosis for human immunodeficiency/hepatitis C virus co-infected patients, and severe steatosis only for a non-3 hepatitis C virus genotype.

AIM: To evaluate the impact of the Glu167Lys (E167K) transmembrane 6 superfamily member 2 (TM6SF2) variant on the biochemical and morphologic expression of liver lesions in human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infected patients. METHODS: The study comprised 167 consecutive patients with HIV/HCV coinfection and biopsy-proven chronic hepatitis. A pathologist graded liver fibrosis and necroinflammation using the Ishak scoring system, and steatosis using Kleiner's scoring system. Patients were genotyped for TM6SF2 E167K (rs58542926) by real-time Polymerase chain reaction. The 167 patients, 35 therapy-naive and 132 receiving ART, were prevalently males (73.6%), the median age was 40.7 years and the immunological condition good (median CD4+ cells/mm3 = 505.5). RESULTS: The 17 patients with the TM6SF2 E167K variant, compared with the 150 with TM6SF2-E/E, showed higher AST (P = 0.02) and alanine aminotransferase (P = 0.02) and higher fibrosis score (3.1 ± 2.0 vs 2.3 ± 1.5, P = 0.05). In a multivariate analysis, TM6SF2 E167K was independently associated with severe fibrosis. The same analysis showed that HCV-genotype 3, present in 42.2% of patients was an independent predictor of severe steatosis. The association of TM6SF2 E167K with severe steatosis, absent for the whole group of 167 patients, was re-evaluated separately for HCV-genotype 3 and non-3 patients: No factor was independently associated with severe steatosis in the HCV-genotype-3 subgroup, whereas an independent association was observed between severe steatosis and TM6SF2 E167K in non-3 HCV genotypes. No association between the TM6SF2 E167K variant and severe liver necroinflammation was observed. CONCLUSION: In HIV/HCV coinfection the TM6SF2 E167K variant is an independent predictor of severe fibrosis, but appears to be independently associated with severe steatosis only for patients with a non-3 HCV genotype.

Resistance to linezolid in Staphylococcus spp. clinical isolates associated with ribosomal binding site modifications: novel mutation in domain V of 23S rRNA.

Linezolid is the main representative of the oxazolidinones, introduced in 2000 in clinical practice to treat severe Gram-positive infections. This compound inhibits protein synthesis by binding to the peptidyl transferase centre of the 50S bacterial ribosomal subunit. The aim of this study was to characterize 12 clinical strains of linezolid-resistant Staphylococcus spp. isolated in Northern Italy. All isolates of Staphylococcus spp. studied showed a multi-antibiotic resistance phenotype. In particular, all isolates showed the presence of the mecA gene associated with SSCmec types IVa, V or I. Mutations in domain V of 23S rRNA were shown to be the most prevalent mechanism of linezolid resistance: among these a new C2551T mutation was found in S. aureus, whilst the G2576T mutation was shown to be the most prevalent overall. Moreover, three S. epidermidis isolates were shown to have linezolid resistance associated only with alterations in both L3 and L4 ribosomal proteins. No strain was shown to harbor the previously described cfr gene. These results have shown how the clinical use of linezolid in Northern Italy has resulted in the selection of multiple antibiotic-resistant clinical isolates of Staphylococcus spp., with linezolid resistance in these strains being associated with mutations in 23S rRNA or ribosomal proteins L3 and L4.

Correction: Pyrosequencing Unveils Cystic Fibrosis Lung Microbiome Differences Associated with a Severe Lung Function Decline.

[This corrects the article DOI: 10.1371/journal.pone.0156807.].

Pyrosequencing Unveils Cystic Fibrosis Lung Microbiome Differences Associated with a Severe Lung Function Decline.

Chronic airway infection is a hallmark feature of cystic fibrosis (CF) disease. In the present study, sputum samples from CF patients were collected and characterized by 16S rRNA gene-targeted approach, to assess how lung microbiota composition changes following a severe decline in lung function. In particular, we compared the airway microbiota of two groups of patients with CF, i.e. patients with a substantial decline in their lung function (SD) and patients with a stable lung function (S). The two groups showed a different bacterial composition, with SD patients reporting a more heterogeneous community than the S ones. Pseudomonas was the dominant genus in both S and SD patients followed by Staphylococcus and Prevotella. Other than the classical CF pathogens and the most commonly identified non-classical genera in CF, we found the presence of the unusual anaerobic genus Sneathia. Moreover, the oligotyping analysis revealed the presence of other minor genera described in CF, highlighting the polymicrobial nature of CF infection. Finally, the analysis of correlation and anti-correlation networks showed the presence of antagonism and ecological independence between members of Pseudomonas genus and the rest of CF airways microbiota, with S patients showing a more interconnected community in S patients than in SD ones. This population structure suggests a higher resilience of S microbiota with respect to SD, which in turn may hinder the potential adverse impact of aggressive pathogens (e.g. Pseudomonas). In conclusion, our findings shed a new light on CF airway microbiota ecology, improving current knowledge about its composition and polymicrobial interactions in patients with CF.

Upregulation of TMEM16A Protein in Bronchial Epithelial Cells by Bacterial Pyocyanin.

Induction of mucus hypersecretion in the airway epithelium by Th2 cytokines is associated with the expression of TMEM16A, a Ca2+-activated Cl- channel. We asked whether exposure of airway epithelial cells to bacterial components, a condition that mimics the highly infected environment occurring in cystic fibrosis (CF), also results in a similar response. In cultured human bronchial epithelial cells, treatment with pyocyanin or with a P. aeruginosa culture supernatant caused a significant increase in TMEM16A function. The Ca2+-dependent Cl- secretion, triggered by stimulation with UTP, was particularly enhanced by pyocyanin in cells from CF patients. Increased expression of TMEM16A protein and of MUC5AC mucin by bacterial components was demonstrated by immunofluorescence in CF and non-CF cells. We also investigated TMEM16A expression in human bronchi by immunocytochemistry. We found increased TMEM16A staining in the airways of CF patients. The strongest signal was observed in CF submucosal glands. Our results suggest that TMEM16A expression/function is upregulated in CF lung disease, possibly as a response towards the presence of bacteria in the airways.

Characterization of Staphylococcus aureus small colony variant strains isolated from Italian patients attending a regional cystic fibrosis care centre.

Small colony variant (SCV) Staphylococcus aureus are a subpopulation of auxotroph, slow-growing strains causing persisting and relapsing infections in cystic fibrosis (CF) patients. Twenty-eight SCV and 29 normal S. aureus strains were isolated from 42 out of 222 Italian CF patients. The isolates were characterized for: susceptibility to antibiotics, methicillin-resistance (MR), Panton Valentine leukocidin, auxotrophy, hypermutability and biofilm formation. Clonal identity of SCV and normal strains was determined by pulsed-field gel electrophoresis. We found that 27 out of 28 SCVs were thymidine-dependent. Furthermore, in contrast to normal phenotype, SCVs were characterized by antibiotic resistance. We also found that 39.3% SCV vs 20.7% normal strains were strong mutators. Moreover, SCVs showed a higher capability to form biofilm compared to normal strains (100% vs 59%). Importantly, we found evidence of clonal spread of SCV strain among CF patients. Using molecular typing, we found that five patients shared the same type A and five out of seven MR-SCV belonged to the same clone (Clone C). The particular virulence and spreading ability of MR-SCV observed highlights the importance of accurate identification and susceptibility testing of these strains. It is important to adopt the optimal approach to treat patients and to prevent cross-infection in CF centres.

Changes in cystic fibrosis airway microbial community associated with a severe decline in lung function.

Cystic fibrosis (CF) is a genetic disease resulting in chronic polymicrobial infections of the airways and progressive decline in lung function. To gain insight into the underlying causes of severe lung diseases, we aimed at comparing the airway microbiota detected in sputum of CF patients with stable lung function (S) versus those with a substantial decline in lung function (SD). Microbiota composition was investigated by using culture-based and culture-independent methods, and by performing multivariate and statistical analyses. Culture-based methods identified some microbial species associated with a worse lung function, i.e. Pseudomonas aeruginosa, Rothia mucilaginosa, Streptococcus pneumoniae and Candida albicans, but only the presence of S. pneumoniae and R. mucilaginosa was found to be associated with increased severe decline in forced expiratory volume in 1 second (FEV1). Terminal-Restriction Fragment Length Polymorphism (T-RFLP) analysis revealed a higher bacterial diversity than that detected by culture-based methods. Molecular signatures with a statistically significant odds ratio for SD status were detected, and classified as Pseudomonas, Burkholderia and Shewanella, while for other Terminal Restriction Fragments (T-RFs) no species assignation was achieved. The analysis of T-RFLP data using ecological biodiversity indices showed reduced Evenness in SD patients compared to S ones, suggesting an impaired ecology of the bacterial community in SD patients. Statistically significant differences of the ecological biodiversity indices among the three sub-groups of FEV1 (normal/mild vs moderate vs severe) were also found, suggesting that the patients with moderate lung disease experienced changes in the airway assembly of taxa. Overall, changes in CF airway microbial community associated with a severe lung function decline were detected, allowing us to define some discriminatory species as well as some discriminatory T-RFs that represent good candidates for the development of predictive biomarkers of substantial decline in lung function.

First report of chronic pulmonary infection by KPC-3-producing and colistin-resistant Klebsiella pneumoniae sequence type 258 (ST258) in an adult patient with cystic fibrosis.

The spread of Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae continues to increase, and the possible development of KPC-producing K. pneumoniae infections in cystic fibrosis (CF) patients is a matter of concern. Here, we describe the establishment of a chronic lung infection due to a colistin-resistant KPC-producing K. pneumoniae isolate in an Italian CF patient.

Lifestyle counselling in primary care: long-term effects on cholesterol level.

OBJECTIVE: To evaluate the long-term effectiveness of lifestyle counselling for low-moderate cardiovascular (CV) risk subjects in primary care. DESIGN: Prospective comparison of baseline vs post-intervention, and comparison of enrolled patients vs control subjects extracted from a large primary care database. SETTING: 94 general practices in Italy. PARTICIPANTS: All the 20-70-year-old hypercholesterolaemic subjects who did not qualify for statin treatment according to the guidelines and who were seen on 12 predetermined working days; 713 patients; 94 general practitioners. INTERVENTION: Short (5-10 min) educational intervention (qualitative dietary advice, encouraging walking or other aerobic physical activities); handing out simple dietetic advice at physician discretion. MAIN OUTCOME MEASURES: Total cholesterol level and global CV risk calculated according to the Framingham equation. RESULTS: Total cholesterol and global CV risk (10 years) decreased by 0.31 mmol/l (p < 0.0001, 95% CI 0.23-0.40) and 1.35% (p < 0.01, 95% CI -1.73 to -0.97), respectively, after a 54-month follow-up. Enrolled patients showed a greater total cholesterol decrease than control patients: 2.24% (p < 0.05, 95% CI 0.58-3.91%). CONCLUSIONS: A simple, office-based, long-term, lifestyle counselling programme produces a small, but clinically significant reduction of total cholesterol and of global CV risk. This result should encourage GPs to systematically offer simple, unstructured lifestyle counselling to all their patients.

Management of erectile dysfunction in general practice.

INTRODUCTION: In recent years, the availability of effective oral pharmacological treatment for erectile dysfunction (ED) has revolutionized its management; however, it is still unclear how everyday clinical practice has changed in response to this evolving scenario. AIM: The aim of this study is to describe general practitioners' (GPs) beliefs and attitudes toward the management of ED. METHODS: Each GP was asked to recruit consecutive men aged >or=18 years and sexually active, with already known erectile problems or with newly diagnosed ED. MAIN OUTCOMES MEASURES: A written questionnaire was used to investigate GPs' sociodemographic characteristics and their beliefs toward the management of ED. RESULTS: Overall, 127 GPs (53.4%) returned the questionnaire and 124 enrolled patients for the study. Only 9.5% of the GPs reported routinely inquiring about ED of patients >40 years of age, whereas 45.7% did it only when the patient raised the problem. GPs' gender and age were associated with their beliefs about ED treatment and referral to specialist care. Overall, 932 patients were enrolled, of whom 38% had newly diagnosed ED. The problem came to light for initiative of patient in 80% of cases, and 84.8% of men were prescribed a treatment. Patients who on their own initiative discussed of their condition had an almost 3-fold increased probability to be treated than those whose GP began the discussion about ED (odds ratio [OR] = 2.6, confidence interval [CI] 95% 1.5-4.5). Patients followed by female physicians were significantly more likely to be referred to a specialist than those followed by male physicians (OR = 3.3, CI 95% 1.4-5.0). CONCLUSIONS: The management of ED has become an integral component of clinical practice in primary care. Nevertheless, barriers in addressing sexual issues still persist. Appropriate training is needed for a proactive approach to ED screening and management in men over 40s.

Importance of glycemic control on the course of glomerular filtration rate in type 2 diabetes with hypertension and microalbuminuria under tight blood pressure control.

BACKGROUND AND AIMS: To evaluate the role of glycemic control on the evolution of glomerular filtration rate (GFR) in type 2 diabetes (T2DM) with mild-moderate hypertension under tight blood pressure control, and to address the current controversy whether diabetic nephropathy worsens, independently of blood pressure, proportionally to HbA1c at any physiological level or only when HbA1c is above a 7.5-8% threshold. METHODS AND RESULTS: T2DM (N=127) during early stage diabetic nephropathy characterized by microalbuminuria were followed during a 2 year multicenter study. Individual GFR profiles were accurately obtained by (51)Cr - EDTA bolus injections and analyzed with linear statistical mixed-effects models. GFR at baseline was significantly negatively correlated with age and plasma creatinine concentration (P