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1.
J Hosp Infect ; 145: 77-82, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38145810

RESUMEN

BACKGROUND: Nebulized therapy is the mainstay for treating obstructive airway diseases, but there is heightened concern about the potential risk for SARS-CoV-2 transmission during nebulization in COVID-19 patients. AIM: To investigate the effects of 0.9% saline nebulization on SARS-CoV-2 RNA spreading in 11 COVID-19 patients (five females, mean age 62.45 ± 9.31 years); also to ascertain whether saline nebulization changed the number of exhaled bio-aerosol particles in six out of the 11 patients. METHODS: Air samples were collected using suction pumps equipped with 0.45 µm PTFE filters and positioned around the patient's bed. Exhaled particles were quantified by using an optical particle counter. FINDINGS: At baseline (i.e. before nebulization) SARS-CoV-2 was detected more frequently in the pumps close to the patient than in those far away. After saline nebulization, the detection of SARS-CoV-2 in the pumps close to the patient was comparable to that observed at baseline. In the pumps far from the patient, saline nebulization slightly, but not significantly, increased SARS-CoV-2 RNA detection compared to baseline. Overall, no significant changes in the SARS-CoV-2 RNA detection were observed after saline nebulization. At baseline, exhaled particle emission varied among patients, with two of them showing higher emission of particles than the remaining patients. Saline nebulization induced a marked decrease in exhaled particles in the two patients who displayed high emission at baseline, whereas no changes were observed in the remaining patients. Saline nebulization did not significantly change SARS-CoV-2 RNA spreading. CONCLUSION: Saline nebulization does not significantly increase SARS-CoV-2 spreading.


Asunto(s)
COVID-19 , Femenino , Humanos , Persona de Mediana Edad , Anciano , SARS-CoV-2 , ARN Viral , Aerosoles y Gotitas Respiratorias , Solución Salina
2.
Diagn Microbiol Infect Dis ; 107(2): 116032, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37531698

RESUMEN

Due to the increasing diffusion of MDR/XDR Gram-negatives it is necessary to offer reliable antibiotic susceptibility testing (AST), which also include new drugs. Here we evaluated the performances of the VITEK®2 AST-N376 and the AST-N397 cards. A collection of 180 clinical Gram-negative bacteria, producing relevant resistance mechanisms, were tested using VITEK 2 and MERLIN, in parallel. Discrepancies between the 2 systems were solved by the reference broth microdilution method. The workflow timing of the VITEK®2 system was also assessed. Overall, the VITEK®2 cards proved to be reliable in determining AST for the molecules evaluated, even if compliance with ISO acceptance criteria for accuracy assessment was not reached for some combinations and showed a short hands-on time for panels preparation. In conclusion, VITEK®2 is a valid system that ensures accurate results for AST of the molecules evaluated in this study and speeds up the workflow in the laboratory of diagnostic microbiology.


Asunto(s)
Antibacterianos , Bacterias Gramnegativas , Humanos , Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana
4.
Eur Rev Med Pharmacol Sci ; 27(9): 4316-4325, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-37203858

RESUMEN

Bacterial multidrug resistance has been a serious issue for healthcare systems in recent decades, responsible for many infections and deaths. Due to the increasing incidence of antimicrobial resistance and scarce treatment options, research is focused on finding possible therapeutic adjuvants able to increase the efficacy of antibiotics. The aim of this article is a review of available evidence on the use of N-acetylcysteine (NAC). MEDLINE/PubMed was searched for appropriate keywords. In vitro and in vivo preclinical studies, clinical studies, reviews, and meta-analyses were retrieved and selected based on relevance. A narrative review article was written, reporting published evidence and the expert opinion of the authors. Among possible adjunctive treatments, NAC has attracted the interest of researchers as a candidate for re-purposing. It is a widely used drug with a good tolerability profile, mainly used as a mucolytic agent, with antioxidant, anti-inflammatory properties and antibacterial activity. NAC acts on different mechanisms and stages of infections, resulting in inhibition of biofilm formation, disruption of preformed biofilms, and reduction of bacterial viability. NAC may be administered as an aerosol in many types of infections, including cystic fibrosis, bronchiectasis and infective flare of chronic obstructive pulmonary disease (COPD), and by the intravenous route in severe systemic infections (including septic shock) such as those caused by carbapenemase (KPC)-producing Klebsiella pneumoniae (Kp) and Carbapenem-Resistant Acinetobacter baumannii (CR-Ab). A rationale exists for using NAC as an adjunctive treatment in multidrug-resistant (MDR) infections, based on in vitro, in vivo and clinical evidence, and future research is needed to identify candidate patients and optimal schedules for specific clinical conditions.


Asunto(s)
Infecciones por Klebsiella , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Acetilcisteína/farmacología , Acetilcisteína/uso terapéutico , Farmacorresistencia Bacteriana Múltiple , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Expectorantes/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Klebsiella pneumoniae , Pruebas de Sensibilidad Microbiana
5.
J Endocrinol Invest ; 45(5): 973-980, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35075607

RESUMEN

PURPOSE: We performed a survey among European semen banks enquiring safety protocols during the COVID-19 pandemic. We report the experience from a center searching SARS-CoV-2 mRNA in semen of patients undergoing cryopreservation from May 2020 to January 2021. METHODS: A questionnaire was submitted to accredited semen banks of the European Academy of Andrology (EAA) and the Italian Society of Andrology and Sexual Medicine (SIAMS). A total of 22 centers answered to the survey. SARS-CoV-2 mRNA in semen was evaluated by RT-PCR in 111 subjects banking in the Semen Bank of Careggi University Hospital (Florence, Italy). RESULTS: No particularly drastic safety measures were adopted by the majority of the centers to prevent the risk of contamination or transmission of the virus. The most common strategy (77.3%) was the administration of an anamnestic questionnaire. About half of the centers request a negative nasopharyngeal swab (NPS) before cryopreservation. Few centers use a quarantine tank, in case of late response of NPS, and only 4 store in a dedicated tank in case of infection. SARS-CoV-2 mRNA was not found in 111 semen samples cryopreserved in the Florentine bank. CONCLUSIONS: European semen banks use different measures to handle semen samples for cryopreservation during COVID-19 pandemic. The request of NPS is advised to better manage couples undergoing ART and to protect the personnel operating in the bank/ART center. Finally, due to the areas of uncertainties of an almost unknown virus, it is absolutely recommended the use of safe devices for sample handling and storage.


Asunto(s)
COVID-19 , COVID-19/epidemiología , COVID-19/prevención & control , Humanos , Pandemias , ARN Mensajero , SARS-CoV-2 , Semen , Encuestas y Cuestionarios
6.
Hum Reprod ; 36(6): 1520-1529, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-33522572

RESUMEN

STUDY QUESTION: How is the semen quality of sexually active men following recovery from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection? SUMMARY ANSWER: Twenty-five percent of the men with recent SARS-Cov-2 infections and proven healing were oligo-crypto-azoospermic, despite the absence of virus RNA in semen. WHAT IS KNOWN ALREADY: The presence of SARS-CoV-2 in human semen and its role in virus contagion and semen quality after recovery from coronavirus disease 2019 (COVID-19) is still unclear. So far, studies evaluating semen quality and the occurrence of SARS-CoV-2 in semen of infected or proven recovered men are scarce and included a limited number of participants. STUDY DESIGN, SIZE, DURATION: A prospective cross-sectional study on 43 sexually active men who were known to have recovered from SARS-CoV2 was performed. Four biological fluid samples, namely saliva, pre-ejaculation urine, semen, and post-ejaculation urine, were tested for the SARS-CoV-2 genome. Female partners were retested if any specimen was found to be SARS-CoV-2 positive. Routine semen analysis and quantification of semen leukocytes and interleukin-8 (IL-8) levels were performed. PARTICIPANTS/MATERIALS, SETTING, METHODS: Questionnaires including International Index of Erectile Function and Male Sexual Health Questionnaire Short Form were administered to all subjects. The occurrence of virus RNA was evaluated in all the biological fluids collected by RT-PCR. Semen parameters were evaluated according to the World Health Organization manual edition V. Semen IL-8 levels were evaluated by a two-step ELISA method. MAIN RESULTS AND THE ROLE OF CHANCE: After recovery from COVID-19, 25% of the men studied were oligo-crypto-azoospermic. Of the 11 men with semen impairment, 8 were azoospermic and 3 were oligospermic. A total of 33 patients (76.7%) showed pathological levels of IL-8 in semen. Oligo-crypto-azoospermia was significantly related to COVID-19 severity (P < 0.001). Three patients (7%) tested positive for at least one sample (one saliva; one pre-ejaculation urine; one semen and one post-ejaculation urine), so the next day new nasopharyngeal swabs were collected. The results from these three patients and their partners were all negative for SARS-CoV-2. LIMITATIONS, REASONS FOR CAUTION: Although crypto-azoospermia was found in a high percentage of men who had recovered from COVID-19, clearly exceeding the percentage found in the general population, the previous semen quality of these men was unknown nor is it known whether a recovery of testicular function was occurring. The low number of enrolled patients may limit the statistical power of study. WIDER IMPLICATIONS OF THE FINDINGS: SARS-CoV-2 can be detected in saliva, urine, and semen in a small percentage of men who recovered from COVID-19. One-quarter of men who recovered from COVID-19 demonstrated oligo-crypto-azoospermia indicating that an assessment of semen quality should be recommended for men of reproductive age who are affected by COVID-19. STUDY FUNDING/COMPETING INTEREST(S): None. TRIAL REGISTRATION NUMBER: N/A.


Asunto(s)
COVID-19 , SARS-CoV-2 , Estudios Transversales , Femenino , Humanos , Masculino , Estudios Prospectivos , ARN Viral , Semen , Análisis de Semen
8.
Clin Microbiol Infect ; 26(10): 1413.e1-1413.e7, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32006694

RESUMEN

OBJECTIVES: To evaluate the performance of an isothermal microcalorimetry (IMC) method for determining the MICs among extensively drug-resistant Gram-negative bacilli. METHODS: A collection of 320 clinical isolates (n = 80 of each) of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii from Sweden, Spain, Italy and the Netherlands were tested. The MICs were determined using the IMC device calScreener (Symcel, Stockholm, Sweden) and ISO-broth microdilution as the reference method. Essential agreement, categorical agreement, very major errors (VME), major errors (ME) and minor (mE) errors for each antibiotic were determined. RESULTS: Data from 316 isolates were evaluated. Four errors (two ME, one VME, one mE) among 80 K. pneumoniae, six errors (four ME, one VME, one mE) among 79 E. coli, 15 errors (seven VME, three ME, five mE) among 77 P. aeruginosa and 18 errors (12 VME, two ME, four mE) among 80 A. baumannii were observed. Average essential agreement and categorical agreement of the IMC method were 96.6% (95% confidence interval, 94.2-99) and 97.1% (95% confidence interval, 95.4-98.5) respectively when the MICs were determined at the end of 18 hours. Categorical agreement of the IMC method for prediction of MIC by the end of 8 hours for colistin, meropenem, amikacin, ciprofloxacin and piperacillin/tazobactam were 95%, 91.4%, 94%, 95.2% and 93.7% respectively. CONCLUSIONS: The IMC method could accurately determine the MICs among extensively drug-resistant clinical isolates of E. coli, K. pneumoniae, P. aeruginosa and A. baumannii isolates.


Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Calorimetría/métodos , Farmacorresistencia Bacteriana Múltiple/fisiología , Escherichia coli/efectos de los fármacos , Klebsiella pneumoniae/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Acinetobacter baumannii/aislamiento & purificación , Acinetobacter baumannii/metabolismo , Amicacina/farmacología , Antibacterianos/farmacología , Ciprofloxacina/farmacología , Colistina/farmacología , Escherichia coli/aislamiento & purificación , Escherichia coli/metabolismo , Humanos , Italia , Klebsiella pneumoniae/aislamiento & purificación , Klebsiella pneumoniae/metabolismo , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana , Países Bajos , Combinación Piperacilina y Tazobactam/farmacología , Pseudomonas aeruginosa/aislamiento & purificación , Pseudomonas aeruginosa/metabolismo , España , Suecia
9.
Clin Microbiol Infect ; 26(6): 713-722, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31610299

RESUMEN

BACKGROUND: Treating severe infections due to multidrug-resistant Gram-negative bacteria (MDR-GNB) is one of the most important challenges for clinicians worldwide, partly because resistance may remain unrecognized until identification of the causative agent and/or antimicrobial susceptibility testing (AST). Recently, some novel rapid test for identification and/or AST of MDR-GNB from positive blood cultures or the blood of patients with bloodstream infections (BSIs) have become available. OBJECTIVES: The objective of this narrative review is to discuss the advantages and limitations of different rapid tests for identification and/or AST of MDR-GNB from positive blood cultures or the blood of patients with BSI, as well as the available evidence on their possible role to improve therapeutic decisions and antimicrobial stewardship. SOURCES: Inductive PubMed search for publications relevant to the topic. CONTENT: The present review is structured in the following way: (a) rapid tests on positive blood cultures; (b) rapid tests directly on whole blood; (c) therapeutic implications. IMPLICATIONS: Novel molecular and phenotypic rapid tests for identification and AST show the potential for favourably influencing patients' outcomes and results of antimicrobial stewardship interventions by reducing both the time to effective treatment and the misuse of antibiotics, although the interpretation about their impact on actual therapeutic decisions and patients' outcomes is still complex. Factors such as feasibility and personnel availability, as well as the detailed knowledge of the local microbiological epidemiology, need to be considered very carefully when implementing novel rapid tests in laboratory workflows and algorithms. Providing high-level, comparable evidence on the clinical impact of rapid identification and AST is becoming of paramount importance for MDR-GNB infections, since in the near future rapid identification of specific resistance mechanisms could be crucial for guiding rapid, effective, and targeted therapy against specific resistance mechanisms.


Asunto(s)
Bacteriemia/diagnóstico , Farmacorresistencia Bacteriana Múltiple , Infecciones por Bacterias Gramnegativas/diagnóstico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Programas de Optimización del Uso de los Antimicrobianos , Bacteriemia/tratamiento farmacológico , Cultivo de Sangre/métodos , Bacterias Gramnegativas/efectos de los fármacos , Infecciones por Bacterias Gramnegativas/tratamiento farmacológico , Humanos , Pruebas de Sensibilidad Microbiana
10.
Clin Microbiol Infect ; 25(11): 1432.e1-1432.e4, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31425743

RESUMEN

OBJECTIVES: The aim was to evaluate different methods for testing carbapenem susceptibility of Escherichia coli producing KPC-type carbapenemase. METHODS: Susceptibility to imipenem, meropenem and ertapenem was assayed using the reference broth microdilution method and several commercial methods (Vitek2, MicroScan, Etest, MIC Test Strip) starting from the same bacterial suspension. Susceptibility to imipenem and meropenem was also tested by Sensititre and disc diffusion (Bio-Rad). Results were interpreted according to EUCAST clinical breakpoints. Essential agreement (EA), category agreement (CA) and error rates were calculated as described by the International Organization for Standardization (ISO) guidelines and also considering the new EUCAST definitions. Genotypic diversity of isolates was evaluated with a RAPD profiling protocol. RESULTS: Of 54 KPC-positive E. coli isolates, 5.6%, 7.4% and 0% were susceptible standard dosing regimen (S), 55.6%, 72.2% and 0% susceptible increased exposure (I), and 38.9%, 20.4% and 100.0% resistant (R) to imipenem, meropenem and ertapenem, respectively, using the reference broth microdilution method. CA lower than 90% were observed with all systems for imipenem and meropenem using both the ISO and the modified EUCAST criteria. With ertapenem, CA >90% was observed with all methods except Vitek2. RAPD profiling revealed a remarkable genotypic diversity of the isolates, supporting that results were not biased by an oligoclonal nature of the collection. CONCLUSIONS: Commercial methods can be unreliable for testing susceptibility to carbapenems of KPC-producing E. coli. Susceptibility should be confirmed by reference broth microdilution.


Asunto(s)
Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Carbapenémicos/farmacología , Escherichia coli/efectos de los fármacos , Escherichia coli/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/clasificación , Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Errores Diagnósticos , Ertapenem/farmacología , Escherichia coli/clasificación , Escherichia coli/aislamiento & purificación , Infecciones por Escherichia coli/microbiología , Genotipo , Humanos , Imipenem/farmacología , Meropenem/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Tipificación Molecular , Técnica del ADN Polimorfo Amplificado Aleatorio
11.
J Hosp Infect ; 100(1): 29-34, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-29879446

RESUMEN

BACKGROUND: Long-term acute care rehabilitation facilities (LTACRFs) are affected by carbapenem-resistant Enterobacteriaceae (CRE) in endemic areas. However, the contribution of different subpopulations of patients has not been investigated in these settings. AIM: To study the epidemiology of CRE in an LTACRF, and the effect of an infection control intervention. METHODS: A surveillance programme was implemented in a large Italian LTACRF. The intervention included screening for CRE carriage at admission and weekly (for negative patients), and enforcement of contact precautions plus cohorting (in wards and rehabilitation areas) for presumed and confirmed carriers. Prevalence and incidence of CRE colonization and the number of CRE bacteraemias were monitored over one year. FINDINGS: Overall, 1084 patients underwent screening (adherence 89.8%). At admission, 11.6% of patients were colonized, and 9.9% of those negative at admission subsequently became colonized. These percentages were significantly higher among patients with severe brain injuries (SBIs) who were exposed to a higher intensity of care (44.1% vs 8.6% and 63.5% vs 6.8%, respectively). The majority of CRE bacteraemias occurred in the SBI ward. The intervention was associated with a decline in the incidence of CRE colonization in the SBI ward (from 17.7 to 7.2 acquisitions/100 at-risk patient-weeks), but not in other wards. All CRE isolates were Klebsiella pneumoniae carbapenemase-producing K. pneumoniae. CONCLUSIONS: A peculiar CRE epidemiology was observed in a LTACRF from Italy, with very high rates of carriage and cross-transmission in SBI patients. A simplified infection control bundle was effective at reducing the incidence of CRE colonization in the SBI ward.


Asunto(s)
Enterobacteriaceae Resistentes a los Carbapenémicos/aislamiento & purificación , Transmisión de Enfermedad Infecciosa/prevención & control , Control de Infecciones/métodos , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Cuidados a Largo Plazo , Paquetes de Atención al Paciente/métodos , Bacteriemia/epidemiología , Bacteriemia/microbiología , Bacteriemia/prevención & control , Portador Sano/epidemiología , Portador Sano/microbiología , Portador Sano/prevención & control , Monitoreo Epidemiológico , Humanos , Incidencia , Italia/epidemiología , Infecciones por Klebsiella/microbiología , Infecciones por Klebsiella/prevención & control , Prevalencia
12.
Clin Microbiol Infect ; 24(2): 201.e1-201.e3, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28827120

RESUMEN

OBJECTIVES: To evaluate a novel method, the colistin-MAC test, for phenotypic screening of acquired colistin resistance mediated by transferable mcr-1 resistance determinants, based on colistin MIC reduction in the presence of dipicolinic acid (DPA). METHODS: The colistin-MAC test consists in a broth microdilution method, in which colistin MIC is tested in the absence or presence of DPA (900 µg/mL). Overall, 74 colistin-resistant strains of Enterobacteriaceae (65 Escherichia coli and nine other species), including 61 strains carrying mcr-1-like genes and 13 strains negative for mcr genes, were evaluated with the colistin-MAC test. The presence of mcr-1-like and mcr-2-like genes was assessed by real-time PCR and end-point PCR. For 20 strains, whole-genome sequencing data were also available. RESULTS: A ≥8-fold reduction of colistin MIC in the presence of DPA was observed with 59 mcr-1-positive strains, including 53 E. coli of clinical origin, three E. coli transconjugants carrying MCR-1-encoding plasmids, one Enterobacter cloacae complex and two Citrobacter spp. Colistin MICs were unchanged, increased or at most reduced by twofold with the 13 mcr-negative colistin-resistant strains (nine E. coli and four Klebsiella pneumoniae), but also with two mcr-1-like-positive K. pneumoniae strains. CONCLUSIONS: The colistin-MAC test could be a simple phenotypic test for presumptive identification of mcr-1-positive strains among isolates of colistin-resistant E. coli, based on a ≥8-fold reduction of colistin MIC in the presence of DPA. Evaluation of the test with a larger number of strains, species and mcr-type resistance determinants would be of interest.


Asunto(s)
Antibacterianos/farmacología , Colistina/farmacología , Genes Bacterianos/genética , Pruebas de Sensibilidad Microbiana/métodos , Farmacorresistencia Bacteriana , Escherichia coli/genética , Infecciones por Escherichia coli/tratamiento farmacológico , Infecciones por Escherichia coli/microbiología , Proteínas de Escherichia coli/genética , Humanos , Fenotipo
13.
Clin Microbiol Infect ; 24(2): 133-144, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28893689

RESUMEN

BACKGROUND: Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) has become one of the most important contemporary pathogens, especially in endemic areas. AIMS: To provide practical suggestion for physicians dealing with the management of KPC-KP infections in critically ill patients, based on expert opinions. SOURCES: PubMed search for relevant publications related to the management of KPC-KP infections. CONTENTS: A panel of experts developed a list of 12 questions to be addressed. In view of the current lack of high-level evidence, they were asked to provide answers on the bases of their knowledge and experience in the field. The panel identified several key aspects to be addressed when dealing with KPC-KP in critically ill patients (preventing colonization in the patient, preventing infection in the colonized patient and colonization of his or her contacts, reducing mortality in the infected patient by rapidly diagnosing the causative agent and promptly adopting the best therapeutic strategy) and provided related suggestions that were based on the available observational literature and the experience of panel members. IMPLICATIONS: Diagnostic technologies could speed up the diagnosis of KPC-KP infections. Combination treatment should be preferred to monotherapy in cases of severe infections. For non-critically ill patients without severe infections, results from randomized clinical trials are needed for ultimately weighing benefits and costs of using combinations rather than monotherapy. Multifaceted infection control interventions are needed to decrease the rates of colonization and cross-transmission of KPC-KP.


Asunto(s)
Proteínas Bacterianas/metabolismo , Infecciones por Klebsiella/tratamiento farmacológico , Klebsiella pneumoniae/efectos de los fármacos , beta-Lactamasas/metabolismo , Antibacterianos/uso terapéutico , Humanos , Klebsiella pneumoniae/enzimología , Resistencia betalactámica
15.
Eur J Clin Microbiol Infect Dis ; 36(10): 1739-1748, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28470337

RESUMEN

The spread of multi-drug resistant (MDR) Klebsiella pneumoniae strains producing carbapenemases points to a pressing need for new antibacterial agents. To this end, the in-vitro antibacterial activity of a synthetic N-terminal peptide of human lactoferrin, further referred to as hLF1-11, was evaluated against K. pneumoniae strains harboring different carbapenemase genes (i.e. OXA-48, KPC-2, KPC-3, VIM-1), with different susceptibility to colistin and other antibiotics, alone or in combination with conventional antibiotics (gentamicin, tigecycline, rifampicin, clindamycin, and clarithromycin). An antimicrobial peptide susceptibility assay was used to assess the bactericidal activity of hLF1-11 against the different K. pneumoniae strains tested. The synergistic activity was evaluated by a checkerboard titration method, and the fractional inhibitory concentration (FIC) index was calculated for the various combinations. hLF1-11 was more efficient in killing a K. pneumoniae strain susceptible to most antimicrobials (including colistin) than a colistin-susceptible strain and a colistin-resistant MDR K. pneumoniae strain. In addition, hLF1-11 exhibited a synergistic effect with the tested antibiotics against MDR K. pneumoniae strains. The results of this study indicate that resistance to hLF1-11 and colistin are not strictly associated, and suggest an hLF1-11-induced sensitizing effect of K. pneumoniae to antibiotics, especially to hydrophobic antibiotics, which are normally not effective on Gram-negative bacteria. Altogether, these data indicate that hLF1-11 in combination with antibiotics is a promising candidate to treat infections caused by MDR-K. pneumoniae strains.


Asunto(s)
Antibacterianos/farmacología , Enterobacteriaceae Resistentes a los Carbapenémicos/efectos de los fármacos , Sinergismo Farmacológico , Klebsiella pneumoniae/efectos de los fármacos , Lactoferrina/farmacología , Péptidos/farmacología , Proteínas Bacterianas/genética , Enterobacteriaceae Resistentes a los Carbapenémicos/enzimología , Enterobacteriaceae Resistentes a los Carbapenémicos/genética , Humanos , Klebsiella pneumoniae/enzimología , Klebsiella pneumoniae/genética , Lactoferrina/genética , Pruebas de Sensibilidad Microbiana , Péptidos/genética , beta-Lactamasas/genética
16.
Epidemiol Infect ; 145(3): 515-522, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27804902

RESUMEN

The diseases caused by non-tuberculous mycobacteria (NTM), in both AIDS and non-AIDS populations, are increasingly recognized worldwide. Although the American Thoracic Society published the guidelines for diagnosis of NTM pulmonary disease (NTM-PD), the diagnosis is still difficult. In the first part of the study, we collected data on NTM isolates in the Mycobacteriology Laboratory of Careggi Hospital (Florence, Italy) and analysed the epidemiological data of NTM isolates. Then, to analyse the risk factors associated to NTM-PD, we studied the presence of ATS/IDSA criteria for NTM-PD in patients who had at least one positive respiratory sample for NTM and were admitted to the Infectious Disease Unit and the Section of Respiratory Medicine. We selected 88 patients with available full clinical data and, according to ATS/IDSA criteria, classified 15 patients (17%) as NTM-PD cases and 73 as colonized patients (83%). When comparing colonized and NTM-PD patients we did not find significant differences of age, gender and comorbidity. We observed that Mycobacterium avium and M. intracellulare were statistically associated with NTM-PD (P = 0·001) whereas M. xenopi was statistically associated with colonization. Although the number of studied patients is limited, our study did not identify risk factors for NTM-PD that could help clinicians to discriminate between colonization and disease. We underline the need of close monitoring of NTM-infected patients until the diagnosis is reasonably excluded. Further larger prospective studies and new biological markers are needed to identify new useful tools for the diagnosis of NTM-PD.


Asunto(s)
Enfermedades Pulmonares/epidemiología , Enfermedades Pulmonares/microbiología , Infecciones por Mycobacterium no Tuberculosas/epidemiología , Infecciones por Mycobacterium no Tuberculosas/microbiología , Micobacterias no Tuberculosas/aislamiento & purificación , Anciano , Anciano de 80 o más Años , Portador Sano/epidemiología , Portador Sano/microbiología , Femenino , Humanos , Italia/epidemiología , Enfermedades Pulmonares/patología , Masculino , Persona de Mediana Edad , Infecciones por Mycobacterium no Tuberculosas/patología , Micobacterias no Tuberculosas/clasificación , Estudios Retrospectivos , Factores de Riesgo
17.
Genome Announc ; 4(5)2016 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-27587821

RESUMEN

Clostridium difficile, belonging to ribotype 018 (RT018), is one of the most prevalent genotypes circulating in hospital settings in Italy. Here, we report the draft genome of C. difficile CD8-15 belonging to RT018, isolated from a patient with fatal C. difficile-associated infection.

18.
J Infect ; 73(2): 136-44, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27235364

RESUMEN

OBJECTIVES: To describe a spatio-temporal cluster of invasive meningococcal disease (IMD) due to serogroup C meningococci, occurred in a restricted area of Tuscany between January and October 2015, and the results of whole genome sequencing (WGS). METHODS: Surveillance activities and public health measures were implemented in the Region. Bacterial isolates from IMD cases were characterized by the National Reference Laboratory of the Istituto Superiore di Sanità (ISS), and WGS was performed on available strains. The kSNP software was used to identify core genome SNPs. RESULTS: Overall, 28 IMD cases due to meningococcus C were identified up to 31st October, 2015. Of them, 26 were due to meningococcus C:P1.5-1,10-8: F3-6:ST-11 (cc11) and 2 to C:P1.5-1,10-8: F3-6:ST-2780 (cc11). WGS of 13 meningococci isolated during the outbreak occurred in Tuscany in 2015 showed higher similarity when compared with those of 47 C: P1.5-1,10-8: F3-6:ST-11 (cc11) invasive strains from sporadic cases previously detected in Italy. CONCLUSIONS: A highly aggressive meningococcal C strain was involved in the cluster of severe IMD occurred in Tuscany, a Region with high vaccine coverage among children. Whether this was due to low herd immunity related to the short duration of vaccine protection needs further investigation.


Asunto(s)
Genoma Bacteriano , Infecciones Meningocócicas/epidemiología , Neisseria meningitidis Serogrupo C/genética , Neisseria meningitidis Serogrupo C/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antígenos Bacterianos/inmunología , Niño , Brotes de Enfermedades , Monitoreo Epidemiológico , Femenino , Humanos , Inmunidad Colectiva , Incidencia , Italia/epidemiología , Masculino , Infecciones Meningocócicas/inmunología , Infecciones Meningocócicas/microbiología , Vacunas Meningococicas/inmunología , Persona de Mediana Edad , Neisseria meningitidis Serogrupo C/clasificación , Neisseria meningitidis Serogrupo C/patogenicidad , Análisis de Secuencia de ADN , Serotipificación , Agrupamiento Espacio-Temporal , Adulto Joven
19.
Clin Microbiol Infect ; 21(12): 1106.e1-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26278669

RESUMEN

The increasing prevalence of colistin resistance (ColR) Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (Kp) is a matter of concern because of its unfavourable impact on mortality of KPC-Kp bloodstream infections (BSI) and the shortage of alternative therapeutic options. A matched case-control-control analysis was conducted. The primary study end point was to assess risk factors for ColR KPC-Kp BSI. The secondary end point was to describe mortality and clinical characteristics of these infections. To assess risk factors for ColR, 142 patients with ColR KPC-Kp BSI were compared to two controls groups: 284 controls without infections caused by KPC-Kp (control group A) and 284 controls with colistin-susceptible (ColS) KPC-Kp BSI (control group B). In the first multivariate analysis (cases vs. group A), previous colistin therapy, previous KPC-Kp colonization, ≥3 previous hospitalizations, Charlson score ≥3 and neutropenia were found to be associated with the development of ColR KPC-Kp BSI. In the second multivariate analysis (cases vs. group B), only previous colistin therapy, previous KPC-Kp colonization and Charlson score ≥3 were associated with ColR. Overall, ColR among KPC-Kp blood isolates increased more than threefold during the 4.5-year study period, and 30-day mortality of ColR KPC-Kp BSI was as high as 51%. Strict rules for the use of colistin are mandatory to staunch the dissemination of ColR in KPC-Kp-endemic hospitals.


Asunto(s)
Bacteriemia/epidemiología , Colistina/uso terapéutico , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/clasificación , Anciano , Bacteriemia/microbiología , Bacteriemia/mortalidad , Estudios de Casos y Controles , Farmacorresistencia Bacteriana Múltiple , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Infecciones por Klebsiella/mortalidad , Klebsiella pneumoniae/aislamiento & purificación , Masculino , Persona de Mediana Edad , Factores de Riesgo
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