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Clinical validation of human papillomavirus (HPV) assays according to international criteria is prerequisite for their implementation in cervical cancer screening. OncoPredict HPV Quantitative Typing (QT) assay (Hiantis Srl, Milan, Italy) is a novel full-genotyping multiplex real-time PCR quantitative assay targeting E6/E7 genes, allowing individual viral load determination of 12 high-risk (HR) HPV types. Quality controls for sample adequacy, efficiency of nucleic acid extraction and PCR inhibition are included in the assay. Clinical performance of OncoPredict HPV QT test was assessed as part of the "Validation of HPV Genotyping Tests" (VALGENT-2) framework, consisting of 1300 cervical liquid-based cytology (LBC) samples of women aged between 20 and 60 years who had originally attended for routine cervical screening in Scotland. The clinical accuracy of the OncoPredict HPV QT (index test) for the detection of CIN2+ was assessed relative to the GP5+/6+ Enzyme ImmunoAssay (GP5+/6+ EIA) (comparator test), using noninferiority criteria. Intra- and interlaboratory reproducibility of the assay was assessed on a subpopulation, comprising 526 samples. The relative sensitivity and specificity for OncoPredict HPV QT vs GP5+/6+-PCR-EIA were 1.01 (95% CI: 0.99-1.03) and 1.03 (95% CI: 1.0-1.06) respectively. The P-values for noninferiority were ≤0.001. The intra- and inter-laboratory reproducibility demonstrated a high concordance (>98.7%) with kappas for individual types ranging from 0.66 to 1.00. OncoPredict HPV QT fulfills the international validation criteria for the use of HPV tests in cervical cancer screening.
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Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Neoplasias do Colo do Útero/diagnóstico , Genótipo , Detecção Precoce de Câncer , Técnicas de Genotipagem , Infecções por Papillomavirus/diagnóstico , Reprodutibilidade dos Testes , Papillomaviridae/genética , Sensibilidade e EspecificidadeRESUMO
HPV testing in cervical cancer screening programs offers the possibility of introducing molecular standardized biomarkers for the triage of HPV-positive women. This study aimed to evaluate the role of HPV genotyping and viral load as possible diagnostic biomarkers of high-grade cervical lesions (CIN2+) by performing a preliminary evaluation of a new HPV test. Cervical specimens were obtained from 200 women referred for a colposcopy. Samples were tested using both Anyplex™ II HR-HPV as well as OncoPredict HPV® Screening (SCR) and quantitative typing (QT). Using a cycle threshold cutoff (Ct) of 36.8 for the SCR assay and 1.27 log10 (viral copies/104 cells) for the QT assay, relative clinical sensitivity for CIN2+ and relative clinical specificity for CIN2- as compared to Anyplex™ II HR-HPV were, respectively, 0.92 and 1.00 for SCR and 1.35 and 1.24 for QT. The distribution of high-risk HPV (HR-HPV) genotypes (p = 0.009) as well as the viral copy numbers (CIN2-: 3.7 log10 (viral copies/104 human cells); CIN2+: 4.3 log10 (viral copies/104 human cells); p = 0.047) were found to differ in women with high- and low-grade cervical lesions, suggesting a possible role of HPV genotyping and normalized viral load as potential biomarkers to identify women at increased risk of cervical lesions.
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Infecções por Papillomavirus , Displasia do Colo do Útero , Neoplasias do Colo do Útero , Feminino , Humanos , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/patologia , Papillomavirus Humano , Genótipo , Carga Viral , Detecção Precoce de Câncer , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/diagnóstico , Papillomaviridae/genética , BiomarcadoresRESUMO
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.
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Farmacorresistência Bacteriana/genética , Linezolida/farmacologia , RNA Ribossômico 23S/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Antibacterianos/farmacologia , Sequência de Bases , Humanos , MutaçãoRESUMO
Aerial parts of Achillea moschata Wulfen (Asteraceae) growing wild in the Italian Rhaetian Alps were investigated to describe, for the first time, their phenolic content, as well as to characterize the essential oil. Inspection of the metabolic profile combining HPLC-DAD and ESI-MS/MS data showed that the methanol extract contained glycosylated flavonoids with luteolin and apigenin as the main aglycones. Among them, the major compound was 7-O-glucosyl apigenin. Caffeoyl derivates were other phenolics identified. The essential oil obtained by steam distillation and investigated by GC/FID and GC/MS showed camphor, 1,8-cineole, and bornylacetate as the main constituents. The antioxidant capacity of three different extracts with increasing polarity and of the essential oil was evaluated by employing ABTS·+ and DPPH· radical scavenging assays. The methanolic extract was the only significantly effective sample against both synthetic radicals. All samples were also tested against Gram-positive (Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus) and Gram-negative (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa) bacterial species using the disk diffusion assay. The non-polar extracts (dichloromethane and petroleum ether) and the essential oil possessed a broad spectrum of antimicrobial activity expressed according to inhibition zone diameter (8-24 mm).
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Achillea/química , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Bactérias/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Fenóis/química , Fenóis/farmacologia , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Epigenetic biomarkers in cancer have emerged as promising tools for early detection, prognosis, and treatment response prediction. In cervical cells, hypermethylation of the host and viral HPV-genome increases with the severity of lesions, providing a useful biomarker in the triage of hr-HPV-positive women and during treatment. The present study focuses on evaluating the clinical performance of the FAM19A4/miR124-2 methylation test in a population-based cervical screening program. METHODS: Previously collected cervical samples, after bisulfite-converted DNA, were analyzed by PreCursor-M+ kit (distributed by Fujirebio Europe), for DNA methylation. The sensitivity, specificity, and negative/positive predictive values of DNA methylation were compared to histology, colposcopy, the HPV-DNA test, and cytology results. RESULTS: Among the 61-sample set, the specificity of methylation vs. positive histology (≥CIN2) and colposcopy (≥G2) were 87% and 90%, whereas the sensitivity was 50% and 33.3%, respectively. The combination of methylation analysis with standard methods increases diagnostic accuracy. CONCLUSIONS: Overall, we found a good specificity of DNA methylation in comparison to currently used techniques. Further larger studies could support the use of FAM19A4/miR124-2 as reliable biomarkers in the prevention of cervical cancer as triage in the screening protocol.
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The introduction of Human Papillomavirus (HPV) testing in cervical cancer screening enhanced the opportunity to introduce self-collection as an innovative approach to improve coverage rates. Validation and standardization of the pre-analytical and analytical procedures are crucial for the quality assurance of HPV tests on self-collected samples. This study evaluated the analytical performance and the stability of self-collected vaginal samples resuspended in 5 mL of two non-alcohol-based media, eNat® and MSwab® compared to a professionally collected cervical sample, resuspended in 20 mL ThinPrep®, for the detection of high-risk HPV (hrHPV). The impact of the suspension volumes on analytical performance was also evaluated (2 and 5 ml). A good analytical concordance in hrHPV detection in cervical and vaginal self-collected swabs suspended in 5 ml of both non-alcohol-based media was demonstrated (eNat®: 91.2 %, k = 0.821; MSwab®: 91.4 %; k = 0.798). A similar analytical performance was found for samples resuspended in 2 mL (eNat®: 92.9 %, k = 0.811; MSwab®: 92.9 %, k = 0.811) compared to cervical samples. Good nucleic acid stability was demonstrated for vaginal samples stored at 20-25 °C and 37 °C for up to 4 weeks. Results of this preliminary study support the introduction of these media for vaginal self-sampling-based prevention programs. Nevertheless, further research is necessary to evaluate clinical accuracy in larger settings.
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In the context of cervical cancer prevention, where human papillomavirus (HPV) infection is pivotal, HPV testing is replacing Pap Smear in primary screening. This transition offers an opportunity for integrating self-sampling to enhance coverage. We evaluated the accuracy of HPV testing using self-collected urine and vaginal samples, comparing them to physician-collected cervical swabs. From a cohort of 245 women with abnormal cytology, we collected self-sampled vaginal, urine, and clinician-administered cervical specimens. Employing Anyplex™II HPV28 assay, outcomes revealed HPV positivity rates of 75.1% (cervical), 78.4% (vaginal), and 77.1% (urine). Significant, hr-HPV detection concordance was observed between self-taken cervical samples and clinical counterparts (k = 0.898 for vaginal; k = 0.715 for urine). This study extends beyond accuracy, highlighting self-collected sample efficacy in detecting high-grade cervical lesions. The insight underscores self-sampling's role in bolstering participation and aligns with WHO's goal to eliminate cervical cancer by 2030.
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Infecções por Papillomavirus , Neoplasias do Colo do Útero , Feminino , Humanos , Gravidez , Colposcopia , Papillomavirus Humano , Neoplasias do Colo do Útero/diagnóstico , Infecções por Papillomavirus/diagnósticoRESUMO
Urinary tract infections (UTIs) are among the most frequent community-acquired infections worldwide. Escherichia coli is the most common UTI pathogen although underlying host factors such as patients' age and gender may influence prevalence of causative agents. In this study, 61 273 consecutive urine samples received over a 22-month period from outpatients clinics of an urban area of north Italy underwent microbiological culture with subsequent bacterial identification and antimicrobial susceptibility testing of positive samples. A total of 13 820 uropathogens were isolated and their prevalence analyzed according to patient's gender and age group. Overall Escherichia coli accounted for 67.6% of all isolates, followed by Klebsiella pneumoniae (8.8%), Enterococcus faecalis (6.3%), Proteus mirabilis (5.2%), and Pseudomonas aeruginosa (2.5%). Data stratification according to both age and gender showed E. coli isolation rates to be lower in both males aged ≥60 years (52.2%), E. faecalis and P. aeruginosa being more prevalent in this group (11.6% and 7.8%, resp.), as well as in those aged ≤14 years (51.3%) in whom P. mirabilis prevalence was found to be as high as 21.2%. Streptococcus agalactiae overall prevalence was found to be 2.3% although it was shown to occur most frequently in women aged between 15 and 59 years (4.1%). Susceptibility of E. coli to oral antimicrobial agents was demonstrated to be as follows: fosfomycin (72.9%), trimethoprim/sulfamethoxazole (72.9%), ciprofloxacin (76.8%), ampicillin (48.0%), and amoxicillin/clavulanate (77.5%). In conclusion, both patients' age and gender are significant factors in determining UTIs etiology; they can increase accuracy in defining the causative uropathogen as well as providing useful guidance to empiric treatment.
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Infecções Bacterianas/epidemiologia , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Urinárias/epidemiologia , Adolescente , Adulto , Distribuição por Idade , Causalidade , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Medição de Risco , Fatores de Risco , Distribuição por Sexo , Adulto JovemRESUMO
The accuracy of available HPV molecular assays on self-samples needs to be evaluated as compared to clinician-collected samples. This pilot study aimed to investigate the BD Onclarity™ HPV assay on vaginal and first-void urine samples. Sixty-four women referred to colposcopy for cervical dysplasia performed a vaginal self-collection and provided a first-void urine sample, after informed consent. A cervical specimen was collected during the clinician examination. All samples were tested using BD Onclarity™ HPV assay on the BD Viper™ LT System. Overall positive agreement (OPA) between cervical and self-sample results was evaluated using Cohen's kappa value (κ). Using a clinical cut-off of 38.3 Ct for HPV 16 and 34.2 Ct for other HR genotypes, compared to cervical sample, the self-collected vaginal sample OPA was 85.9%, and κ = 0.699. Without a clinical cut-off, the OPA was 95.3%, and the κ = 0.890. Data obtained comparing cervical and urine samples showed an OPA of 87.5% with a κ = 0.79 using a clinical cut-off, and an OPA of 90.6% with a κ = 0.776 without a clinical cut-off. Data showed a substantial agreement between both self-collected and clinician-collected samples. A specific clinical cut-off analysis should be considered based on type of sample analysed.
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A multicenter, nonrandomized, prospective, controlled study was conducted to evaluate, as perioperative prophylactic treatment, the anti-infective effectiveness of 0.66% povidone-iodine eye drops (IODIM®) against the bacterial flora of the conjunctival surface of patients who undergo cataract surgery. Eye drops containing 0.66% povidone-iodine were applied to the eye undergoing cataract surgery; the untreated contralateral eye was used as control. One hundred and twenty patients set to receive unilateral cataract surgery were enrolled in 5 Italian Ophthalmology Centers and pretreated for three days with 0.66% povidone-iodine eye drops. The contralateral eye, used as control, was left untreated. Conjunctival swabs of both eyes were collected at the baseline visit and after three days of treatment, just before the cataract surgery. A qualitative and quantitative microbiological analysis of bacterial presence was evaluated by means of bacterial culture, followed by identification. Methicillin resistance determination was also performed on staphylococci isolates. Bacterial load before and after treatment of the eye candidate for cataract surgery was evaluated and compared to the untreated eye. A reduction or no regrowth on the culture media of the bacterial load was observed in 100% of the study subjects. A great heterogenicity of bacterial species was found. The 0.66% povidone-iodine eye drops, used for three days prior to cataract surgery, were effective in reducing the conjunctival bacterial load. The 0.66% povidone-iodine eye drops (IODIM®) might represent a valid perioperative prophylactic antiseptic adjuvant treatment to protect the ocular surface from microbial contamination in preparation of the surgical procedure.
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Legionella pneumophila is ubiquitous in aquatic environments and responsible for severe pneumonia in humans through inhalation of aerosol containing Legionella spp. Macrolides and fluoroquinolones are frequently used antimicrobials, but treatment failures are increasingly being reported. As susceptibility testing is not routinely performed, this study aimed to determine the minimum inhibitory concentrations (MICs) on 58 environmental Legionella pneumophila strains (24 of serogroup 1 and 34 of non-serogroup 1) isolated in Northern Italy. MICs of azithromycin, erythromycin, ciprofloxacin, levofloxacin, and rifampicin were determined by the microdilution method using buffered yeast extract broth supplemented with α-ketoglutarate (BYEα). Seventy-five percent of Legionella pneumophila isolates showed MIC values below the tentative highest MICs indicated by the European Committee on Antimicrobial Susceptibility Testing (EUCAST); rifampicin was the most active agent with MIC90 values below 0.008 mg/L. Interestingly, one isolate was tested and found to be PCR-positive for the azithromycin LpeAB active efflux system, further confirmed by the reserpine/resazurin microtiter assay. In conclusion, this study has provided additional susceptibility data for environmental Legionella pneumophila isolates from Northern Italy demonstrating, in general, low MICs values for the tested antimicrobials, although one strain tested was shown to possess the LpeAB resistance determinant, indicating that future surveillance studies are warranted.
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Legionella pneumophila , Legionella , Antibacterianos/farmacologia , Fluoroquinolonas , Humanos , Testes de Sensibilidade MicrobianaRESUMO
PURPOSE: To evaluate the bactericidal activity of a diluted povidone-iodine formulation (0.6%) in comparison with the most used 5% povidone-iodine solution ophthalmic preparation. METHODS: In vitro bactericidal activity comparison between 0.6% povidone-iodine versus 5% povidone-iodine formulations, against these bacteria: Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 43300, Staphylococcus epidermidis ATCC 12228, linezolid-resistant Staphylococcus epidermidis α99 strain, a clinical isolate, Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922. RESULTS: About 0.6% povidone-iodine formulation was demonstrated to be faster than 5% povidone-iodine preparation in killing Gram-positive as well as Gram-negative bacteria. Against a linezolid-resistant methicillin-resistant Staphylococcus epidermidis strain, 0.6% povidone-iodine formulation showed the best antiseptic efficacy requirement of 3-log10 reduction in bacterial load, if compared with the 5% povidone-iodine formulation. CONCLUSION: Our investigation has demonstrated that the more diluted 0.6% preparation was more rapidly bactericidal than the 5% povidone-iodine formulation, most probably due to the fact that dilution from 5% to 0.6% increases the amount of free iodine. While our finding must be confirmed by in vivo clinical studies, this fact constitutes an intriguing news for what concerns the use of povidone-iodine eye drops in the ocular surface treatment before intravitreal injections as well as ophthalmic surgery.
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Anti-Infecciosos Locais/administração & dosagem , Bactérias/efeitos dos fármacos , Povidona-Iodo/administração & dosagem , Administração Oftálmica , Escherichia coli/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Soluções Oftálmicas , Preparações Farmacêuticas , Pseudomonas aeruginosa/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus epidermidis/efeitos dos fármacosRESUMO
The study purpose was to assess the efficacy of a preservative-free 0.6% povidone iodine eye drops as perioperative prophylactic treatment for reducing conjunctival bacterial load and the rate of needle contamination in patients undergoing intravitreal anti-vascular endothelial growth factor injection. Enrolled patients were randomized to either the study group (0.6% povidone iodine, three day-prophylactic treatment before the injection) or to the control group (placebo, three day-prophylactic treatment). Conjunctival swabs were obtained before and after the prophylactic treatment in both groups. Intravitreal injections were performed in a sterile fashion. The injection needle and a control needle were collected for microbiological culture. Data from 254 and 253 eyes in the study group and control group, respectively, were analyzed. Bacterial growth from conjunctival swab cultures was significantly lower after 0.6% povidone iodine prophylaxis compared to baseline and to placebo prophylaxis (p < 0.001), showing an 82% eradication rate in the study group. No injection needle showed bacterial contamination in the study group, whereas six needles were culture-positive in the control group (p = 0.015). No serious ocular and non-ocular adverse events were recorded. The 0.6% povidone iodine solution proved an effective treatment in reducing conjunctival bacterial load and risk of needle contamination.
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The emergence of multidrug-resistant bacterial strains is particularly important in chronic pathologies such as cystic fibrosis (CF), in which persistent colonization and selection of resistant strains is favored by the frequent and repeated use of antibacterial agents. Staphylococcus aureus is a common pathogen in CF patients that has an associated increased multidrug resistance. In previous studies we demonstrated that the presence of a 4-alkylidene side chain directly linked to a ß-lactam appeared to strengthen the potency against S.â aureus, especially against methicillin-resistant S.â aureus (MRSA) strains. In the present study, 21 new 4-alkylidene-ß-lactams were synthesized and evaluated for antibacterial activity. We designed the new compounds to have aryl, benzyl, or phenethyl-carbamate groups on the C3 hydroxyethyl side chain. We found a correlation between biological activity and the nitrogen substituent of the carbamate group, and two phenethyl-carbamate ß-lactams were shown to be valuable antibacterial agents against selected linezolid-resistant strains, with a minimum inhibitory concentrations of 2-4â mg L-1 .
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Antibacterianos/síntese química , Carbamatos/química , Desenho de Fármacos , beta-Lactamas/química , Antibacterianos/farmacologia , Fibrose Cística/complicações , Fibrose Cística/diagnóstico , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/complicações , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , beta-Lactamas/farmacologiaRESUMO
Circulating HPV DNA has been previously described in women with advanced stages of cervical cancer and has been suggested to be a prognostic marker of disease recurrences and metastases. Only a few studies have reported the presence of HPV DNA in bloodstream of patients with low grade or precancerous cervical lesions. This study aimed to define if HPV DNA could be detected in plasma samples of 120 women referred for a recent history of cervical dysplasia who presented with lesions ranging from High Squamous Intraepithelial Lesion (H-SIL) to regressed normal cytology. HPV DNA detection was carried out in both plasma and cervical samples using type-specific real-time quantitative PCR assays identifying oncogenic HPV 16, 18, 31, 33, 45, 51 and 52. Overall, 34.2% (41/120) of plasma samples were shown to be positive for HPV DNA detection; HPV 45 (46.3%), HPV-51 (29.6%), and HPV 16 (18.5%) were the most frequently identified genotypes. The rate of HPV detection in paired cervical and plasma samples increased with advancing disease stage, ranging from 15.4% in women with regressed lesions to 38.9% in women with HSIL; HPV 16 resulted the most common genotype identified in women found to be HPV DNA positive in both cervical and plasma samples. Moreover, HPV 16 showed the highest median viral load value in both cervical and plasma samples, with 48,313 copies/104 cells and 1,099 copies/ml, respectively. Results obtained in this study confirm that HPV DNA can be detected and quantified in plasma samples of women with asymptomatic cervical infection. Further knowledge on HPV dissemination through the blood stream of women with cervical lesions would be very important in better understanding the natural history of HPV infection as well as its potential role in other distant tumors.
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Alphapapillomavirus/genética , Colo do Útero/virologia , DNA Viral/metabolismo , Displasia do Colo do Útero/virologia , Adulto , DNA Viral/sangue , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
Susceptibility of 96 Listeria monocytogenes human isolates collected in northern Italy between 2008 and 2010, to 15 antimicrobials, was investigated. Minimum inhibitory concentration (MIC) was evaluated by means of the standardized broth microdilution method, according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) international guidelines. All L. monocytogenes human isolates were susceptible to penicillin G (MIC(90)≤0·06 µg/ml), meropenem (MIC(90)≤0·06 µg/ml), and erythromycin (MIC(90)â=â0·12 µg/ml). Susceptibility to the other tested antimicrobials could not be interpreted due to the lack of breakpoint values although two (2%) isolates were shown to have tetracycline MICs above EUCAST epidemiological cut-off values (ECOFF). Bactericidal activity for amoxicillin, gentamicin, and levofloxacin was generally observed at concentrations 2-4 times higher than MIC values. Though L. monocytogenes human strains, isolated in the north of Italy, appear to be susceptible to most antimicrobial agents used in human therapy, this study provides new data for epidemiological surveillance and clinical breakpoints definition.
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Antibacterianos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Humanos , Itália , Testes de Sensibilidade Microbiana/métodosRESUMO
A retrospective study was conducted to determine the prevalence of plasmid-mediated quinolone resistance (PMQR) determinants in uropathogenic Escherichia coli isolated from inpatients and outpatients in a teaching hospital of northern Italy. The presence of qnrA, qnrB, qnrS, aac(6')-Ib-cr, and qepA was evaluated in 76 and 72 nalidixic acid-resistant E. coli, isolated in 2004 and 2006, respectively. Positivity for the aac(6')-Ib-cr gene was demonstrated in 3 of 76 (3.9%) and 8 of 72 (11%) isolates, respectively; no other PMQR determinant was found. All aac(6')-Ib-cr-positive strains also showed two point mutations in the gyrA and parC genes. Most aac(6')-Ib-cr-positive isolates demonstrated the contemporary presence of bla(CTX-M-15), bla(OXA-1/30), and bla(TEM-1) genes and 4/11 harbored a class 1 integron with a dfrA17-aadA5 gene cassette arrangement. Interestingly, all aac(6')-Ib-cr-positive isolates belonged to B2 phylogenetic group, O25b antigen type, multi locus sequence type 131, and to a cluster of approximately 70% similarity level by pulsed-field gel electrophoresis (PFGE). These findings suggest the circulation of the previously described intercontinentally spreading E. coli O25:H4-ST131 clone in our geographical area since 2004. Hybridization studies of the PFGE profiles showed the aac(6')-Ib-cr gene to be associated with different molecular weight bands (40-350 kb) and interestingly aac(6')-Ib-cr chromosomal integration was demonstrated in one strain by I-Ceu I method. This represents the first report to investigate the presence and diffusion of PMQR determinants in northern Italy and to describe aac(6')-Ib-cr chromosomal integration in E. coli.