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E A Debbia

Publications and source records attributed to E A Debbia.

At least 19 recordsLinked to original sources
PubMed2006

Antifungal resistance in Candida spp. isolated in Italy between 2002 and 2005 from children and adults.

The activity of amphotericin B, fluconazole, flucytosine, itraconazole and voriconazole was tested in vitro against 618 clinical Candida spp. isolates, using the broth microdilution or the disk diffusion method (voriconazole). Amphotericin B and voriconazole were the most potent antifungal agents assayed (100% of susceptible strains). Resistance to fluconazole and itraconazole was detected in three (0.7%) and 11 (2.7%) isolates of Candida albicans and in four (3.7%) isolates of Candida glabrata. Flucytosine intermediate, resistant strains, or both, were observed in C. albicans (0.3% and 0.7%), C. glabrata (2.8% intermediate) and C. tropicalis (15.2% and 15.2%). C. krusei was the least susceptible species to azoles. No statistically significant differences in the rates of resistant isolates depending on site of infection and age of the patient were observed, with the exception of C. albicans and itraconazole (higher percentage of resistance in children). At present, acquired antifungal resistance represents an uncommon finding in most Candida spp. circulating in Northern Italy.

Adult↗
PubMed2006

Antibiotic susceptibility tests directly on urine samples using Uro-Quick, a rapid automated system.

During the period June 2003-March 2004, 12,579 urine samples were examined employing the Uro-Quick system. Positive samples (1,948) were subsequently Gram-stained and processed by standard procedures for microorganism identification and antibiotic susceptibility determination by the disk diffusion method. Results of this latter test were compared with those obtained employing the new rapid Uro-Quick method. Antibiotics were introduced in vials containing 2 ml of Mueller-Hinton broth, then 0.5 ml of urine or a bacterial suspension in broth were added; a vial without drug was used as control. After 3 and 5 hours of incubation (for Gram-negative and Gram-positive strains respectively) the instrument showed the results. No growth and a growth curve like the control indicated susceptible and resistant strains respectively. Overall 1,590 Gram-negative strains were tested against ciprofloxacin, nitrofurantoin, amoxicillin-clavulanate, ceftazidime, fosfomycin, imipenem, amikacin, trimethoprim-sulfamethoxazole, and piperacillin-tazobactam, while 358 Gram-positive bacteria were assessed against ciprofloxacin, nitrofurantoin, amoxicillin-clavulanate, ampicillin, fosfomycin, gentamicin, oxacillin and trimethoprim-sulfamethoxazole. Against the major urinary tract pathogens (Escherichia. coli, enterococci, Klebsiella spp. and Proteus spp.) agreement between the Uro-Quick system and the disk diffusion test generally was >90% for all antibiotics tested. On the basis of these results the system appears useful not only for bacteriuria screening, but also to rapidly test the antibiotic susceptibility of common uropathogens.

Anti-Bacterial Agents↗
PubMed2004

In vitro activity of ertapenem against selected respiratory pathogens.

OBJECTIVES: The in vitro activity of ertapenem was evaluated in comparison to 21 selected agents against a large collection of recently isolated respiratory tract pathogens including: 180 Streptococcus pneumoniae, 100 Streptococcus pyogenes, 70 Haemophilus influenzae, 70 Moraxella catarrhalis, 100 methicillin-susceptible Staphylococcus aureus and 30 Klebsiella pneumoniae. Additional in vitro tests (time-kill curves with ertapenem alone and in combination with four other agents) for S. pneumoniae were carried out. METHODS: MIC determinations and time-kill curves were carried out following the procedures suggested by the NCCLS. RESULTS: According to NCCLS susceptibility breakpoints, ertapenem was comparable to the most potent compounds tested for all pathogens studied. Ertapenem was 100% active against penicillin-susceptible and -intermediate S. pneumoniae and against 60% of penicillin-resistant strains. Time-kill tests at 4x MIC confirmed a pronounced bactericidal potency of ertapenem against these organisms. Interactions of ertapenem with several other agents against pneumococci resulted in clear synergic interactions (98.4%). Indifference was extremely rare and antagonism was not observed. All S. pyogenes strains tested were inhibited by ertapenem, irrespective of their macrolide resistance phenotypes. Ertapenem was also fully active against H. influenzae (100% susceptible) and M. catarrhalis (MIC90 0.015-0.03 mg/L) even when capable of synthesizing beta-lactamases. Methicillin-susceptible S. aureus and K. pneumoniae, including extended-spectrum beta-lactamase-producing strains, were 100% susceptible to ertapenem. CONCLUSIONS: Our results indicate that ertapenem has a suitable spectrum of activity against organisms encountered in community-acquired bacterial respiratory tract infections.

Bacteria↗
PubMed2004

Evaluation of the Uro-Quick, a new rapid automated system, for the detection of well-characterized antibiotic-resistant bacteria.

The Uro-Quick system has been employed to detect antibiotic resistance in genotypically and/or phenotypically well-characterized bacterial species including those that might not be easily identified by routine procedure. In order to achieve full agreement between the antibiotic susceptibility results obtained by the reference method (NCCLS) and the Uro-Quick system, the optimal experimental conditions (inoculum size, time of incubation and antibiotic concentration) for each strain to be used by the automatic system were determined. The shorter time periods for generation of correct susceptibility results were 180 min for ampicillin- and ciprofloxacin-resistant Escherichia coli and for ESBL- and Inhibitor-resistant TEM (IRT)-producing E. coli; 360 min for penicillin-susceptible Streptococcus pneumoniae, as well as for strains with reduced susceptibility to this antibiotic (both intermediate, and resistant isolates). The same time was required to detect erythromycin-resistant pneumococci irrespective of their mechanism of resistance (ribosomal methylation and efflux-mediated), Streptococcus pyogenes exhibiting the three erythromycin-resistance phenotypes (constitutive, inducible and M-type) and Klebsiella pneumoniae, Enterobacter aerogenes, Enterobacter cloacae, Serratia marcescens, Proteus mirabilis and Moraxella morganii refractory to third-generation cephalosporins, aminoglycosides, ciprofloxacin and other classes of antimicrobial agents; 480 min for penicillin-resistant, constitutive and inducible oxacillin-resistant (OXA-R) Staphylococcus aureus and OXA-R Staphylococcus epidermidis. The same period of time was also necessary to find the great majority of drug-resistance exhibited by Pseudomonas aeruginosa. Teicoplanin-resistant Staphylococcus haemolyticus, vancomycin-resistant (VanA, VanB, VanC) high-level aminoglycoside-resistant (HLAR) Enterococcus spp, and imipenem-resistant P. aeruginosa required longer incubation (24 h) to be detected. The results obtained indicate that Uro-Quick might be a reliable and promising instrument for the correct detection of the above antibiotic resistance markers.

Anti-Bacterial Agents↗
PubMed2004

Enhanced biofilm-production in pathogens isolated from patients with rare metabolic disorders.

Biofilm-producing bacteria were isolated from the urine of 19 patients with very rare metabolic disorders including: hyperlactacidaemia (8 cases), sugar intolerance and gammopathy (1 case), cystinuria (2 cases), Parkinson's disease (1 case), lipidaemia (2 cases), hyperaminoaciduria (1 case) and others (4 cases). A total of 34 strains were collected, Gram-negative and gram-positive microorganisms were equally distributed among the slime-producing bacteria, with a prevalence of Staphylococcus epidermidis (30%) the most frequent microorganism isolated together with Escherichia coli and Proteus mirabilis that accounted for 15% of this group of strains. A quantitative assay of the biofilm production revealed that in Gram-positive pathogens it was three times greater than that observed in bacteria collected from patients not affected by metabolic diseases (p = 0.0001). In Gram-negative strains the biofilm synthesis was 2.2 times higher than those detected in the same bacteria isolated in the absence of metabolic disorders (p = 0.0033). The results observed indicate that biofilm production is enhanced in bacteria isolated from the urine of patients with metabolic disorders. It is suggested that unusual metabolites might facilitate pathogen production of biofilm found in the urine of these patients.

Bacteriuria↗
PubMed2002

In vitro activity of thiamphenicol against multiresistant Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus in Italy.

Thiamphenicol is a derivative of chloramphenicol characterized by a spectrum comparable to that of the parent compound against multiresistant pathogens but showing satisfactory tolerability. The in vitro activity of thiamphenicol and of 11 comparative drugs against 397 recently isolated antibiotic-resistant and/or invasive pneumococci and 52 multiply-resistant MRSA including 2 VISA strains was determined. Bactericidal activity against Haemophilus influenzae and the post-antibiotic effect on Streptococcus pneumoniae, H. influenzae, Staphylococcus aureus and Escherichia coli were also assessed. Against invasive pneumococci, thiamphenicol and chloramphenicol were the most potent non-beta-lactam molecules together with vancomycin and rifampin. Against high-level penicillin-resistant strains phenicol activities were superior to those of cefotaxime, ceftriaxone and imipenem. Against MRSA thiamphenicol and chloramphenicol were second only to the glycopetides and also inhibited the VISA strains. Thiamphenicol showed a significant PAE (0.33 to 2.9h) on all pathogens studied and a powerful bactericidal effect against beta-lactamase-positive and -negative H. influenzae. These results indicate a good in vitro activity of thiamphenicol against difficult-to-treat multiply resistant pathogens.

Anti-Bacterial Agents↗
PubMed2001

Antibiotic persistence: the role of spontaneous DNA repair response.

Persisters are a small proportion of a bacterial population that exists in a physiological state permitting survival despite the lethal activity of antibiotics. To explain this phenomenon, it has been suggested that persisters are bacteria repairing spontaneous errors of DNA synthesis. To verify this assumption, Escherichia coli AB1157 and its lexA3 derivative were exposed to a dose 6x MIC of various antibiotics representative of different molecular mechanisms of action (ampicillin, ceftriaxone, meropenem, amikacin, ciprofloxacin). Bacterial cell counts, after 24 hr of exposure to the antimicrobials, revealed a reduction of about 90% of viable organisms in the lexA3 strains in comparison to the lexA+. In several cases, the number of colony-forming units decreased below the limit of assay. This behavior was noted with all antibiotics used, alone or in combination (amikacin plus ceftriaxone and amikacin plus ciprofloxacin). The same experiments were repeated using E. coli AB1157 cultured in the presence of mitomycin C (0.25x MIC), and the number of survivors exceeded by about 90% the values found in the nonexposed control. In contrast, in the sulA background, mitomycin C reacted synergically with all the antibiotics tested causing a strong reduction of the survivors in comparison with the control. The addition of chloramphenicol (0.125x MIC), on the contrary, caused a reduction of the number of survivors of about 90%. These findings indicate that, when DNA repair is active (a mechanism known to block cell division), the number of survivors is greater than that observed with lexA3. Thus, in addition to other possible explanations, persisters might be a fraction of bacteria that during antibiotic treatment are not growing because they are repairing spontaneous errors of DNA synthesis.

Anti-Bacterial Agents↗
PubMed2001

Epidemiology of major respiratory pathogens.

A vast literature attests to the fact that Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis represent the prevailing bacterial pathogens of community-acquired lower respiratory tract infections. Their specific incidence as causative agents of the more common syndromes is known to vary even profoundly, depending on geographic area, and the same holds true for their rates of resistance to antimicrobial drugs. Europe does not escape the threat posed by the present pandemic spread of penicillin resistance in S. pneumoniae although, as expected, some countries like Spain and France are highly affected and others including Germany, Italy, The Netherlands and the Scandinavian region, are relatively spared. In several sites multiple resistance has been described in S. pneumoniae with the most affected drugs being penicillin, the macrolides, co-trimoxazole and tetracycline. In H. influenzae synthesis of beta-lactamases is the main resistance trait expressed. Lack of susceptibility to beta-lactams dictated by a different mechanism remains extremely rare. Large variations in the incidence of this character are apparent when considering European countries. France and Spain are again widely affected while Germany, The Netherlands and Italy display rates of beta-lactamase-positive H. influenzae of about 16%. M. catarrhalis must be considered generally resistant to non-protected aminopenicillins since over 90% of these organisms produce beta-lactamases.

Anti-Bacterial Agents↗
PubMed2001

Microbial epidemiology patterns of surgical infection pathogens.

Resistance, as assessed in vitro, has a number of serious consequences in clinical situations. Treatment failures are common when an inappropriate drug has been prescribed and this, in turn, may lead to hospitalization of patients who normally would have been treated on an outpatient basis, as well as to longer hospital stay for inpatients and to the use of alternative drugs, which may be more expensive and more toxic. These factors all contribute to increased health care costs, morbidity and mortality. Microbiological procedures may identify the causative pathogen and provide the appropriate susceptibility pattern to the physician, thus reducing the chances of therapeutic failures. However, for a number of reasons including cost--even in hospitals--not to mention general practice, infections are seldom diagnosed on an etiological basis. From what has been stated, the knowledge of bacterial epidemiology and resistance represents basic support for correct therapeutic decision-making.

Anti-Bacterial Agents↗
PubMed2000

[Emergence of drug-resistant gram-positive pathogenic bacteria].

Staphylococcus aureus is a common cause of soft tissue infection, e.g. impetigo, cellulitis, or wound infection, and causes osteomyelitis, arthritis, bacteremia with metastatic infection, and scalded skin and toxic shock syndromes. Coagulase-negative staphylococci have become increasingly important causes of nosocomial bacteremia associated with invasive monitoring, intravascular catheters and prosthetic heart valves or joints. Most staphylococci produce blactamase and are resistant to penicillin. An increasing proportion of S. aureus have intrinsic resistance to methicillin (MRSA) and present major problems in hospitals for the control of cross infection. The glycopeptides, teicoplanin and vancomycin, are the antibiotics of first choice for treatment of these infections. After the first report describing a Japanese clinical isolate of vancomycin-resistant S. aureus (VRSA), several papers have documented the emergence of these microorganisms. Since the development and spreading of this phenomenon which is perceived as a fearsome threat to the already difficult therapy of nosocomial infections due to the prevalence of heterogeneous vancomycin resistance, we found the incidence of MRSA exceeds 35% in our hospital. Out of 179 methicillin-resistant S. aureus isolated during 1997-1998, two strains (1.1%) gave subclones with vancomycin MICs of 8 mg/L. PFGE showed identical restriction patterns for both isolates, suggesting transfer of a single clone between two different patients.

Cross Infection↗
PubMed2000

Comparative in vitro potency of gemifloxacin against European respiratory tract pathogens isolated in the Alexander Project.

European isolates collected in 1998 for the Alexander Project were tested for their susceptibility to ciprofloxacin, ofloxacin and a novel fluoroquinolone, gemifloxacin, which has a spectrum of activity including common and atypical respiratory pathogens. MIC90s of gemifloxacin for Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis were 0.03, 0.06 and 0.015 mg/L, respectively. On the basis of MIC90s, gemifloxacin was the most potent antimicrobial tested against S. pneumoniae and M. catarrhalis. Against H. influenzae, gemifloxacin was one tube dilution more potent than ofloxacin and one tube dilution less potent than ciprofloxacin. As resistance to currently available antimicrobial agents increases, gemifloxacin offers potential as a promising new agent for the treatment of respiratory tract infection.

Anti-Infective Agents↗
PubMed2000

The evolving threat of antibiotic resistance in Europe: new data from the Alexander Project.

The Alexander Project was established in 1992 to examine the antimicrobial susceptibility of community-acquired lower respiratory tract bacterial pathogens to a range of compounds. Since then it has expanded both geographically and in the number of antimicrobial agents tested. Within Europe, the most recent data have confirmed that the prevalence of penicillin resistance among isolates of Streptococcus pneumoniae is high in France and Spain, with both intermediate (MIC 0.12-1 mg/L) and resistant (MIC > or = 2 mg/L) phenotypes, and combined resistance rates of >50%. Macrolide resistance is increasing generally both among penicillin-resistant and penicillin-susceptible isolates of S. pneumoniae and its prevalence now exceeds that of penicillin resistance, overall (16.5% and 10.4%, respectively, in 1996; 21.9% and 14.1% in 1997; 16.5% and 11.6% in 1998). Beta-lactamase production was the principal mechanism of resistance observed among isolates of Haemophilus influenzae and Moraxella catarrhalis.

Anti-Bacterial Agents↗
PubMed2000

Evolution of antibiotic resistance in gram-positive pathogens.

Staphylococcus aureus is a common cause of soft tissue infection, e.g. impetigo, cellulitis, or wound infection, and causes osteomyelitis, arthritis, bacteremia with metastatic infection, and scalded skin and toxic shock syndromes. Coagulase-negative staphylococci have become increasingly important causes of nosocomial bacteremia associated with invasive monitoring, intravascular catheters and prosthetic heart valves or joints. Most staphylococci produce b-lactamase and are resistant to penicillin. An increasing proportion of S. aureus have intrinsic resistance to methicillin (MRSA) and present major problems in hospitals for the control of cross infection. The glycopeptides, teicoplanin and vancomycin, are the antibiotics of first choice for treatment of these infections. After the first report describing a Japanese clinical isolate of vancomycin-resistant S. aureus (VRSA), several papers have documented the emergence of these microorganisms. Since the development and spreading of this phenomenon which is perceived as a fearsome threat to the already difficult therapy of nosocomial infections due to the prevalence of heterogeneous vancomycin resistance, we found the incidence of MRSA exceeds 35% in our hospital. Out of 179 methicillin-resistant S. aureus isolated during 1997-1998, two strains (1.1%) gave subclones with vancomycin MICs of 8 mg/L. PFGE showed identical restriction patterns for both isolates, suggesting transfer of a single clone between two different patients.

Anti-Bacterial Agents↗
PubMed1999

Epidemiology of resistance to antimicrobial drugs in the major respiratory pathogens circulating in Europe.

There is an overwhelming consensus on the fact that Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis represent the prevailing bacterial pathogens of community-acquired lower respiratory tract infections. Their specific incidence as causative agents of the more common syndromes is known to vary even profoundly depending on geographic location, and the same holds true for the rates of resistance to antimicrobial drugs. Europe does not escape the threat posed by the present pandemic spread of penicillin resistance in S. pneumoniae although, as expected, countries like Spain and France are greatly affected, while others including Germany, Italy, The Netherlands and the Scandinavian region are comparatively spared. In several sites multiple resistance has been described in S. pneumoniae and the most affected drugs include penicillin, the macrolides, co-trimoxazole and tetracycline. In H. influenzae synthesis of beta-lactamases the main trait of resistance is expressed. Lack of susceptibility to beta-lactams dictated by a different mechanism remains extremely rare. Considerable variations in the incidence of this characteristic are apparent when European countries are considered. France and Spain are again widely affected, while Germany, The Netherlands and Italy display rates of beta-lactamase-positive H. influenzae of about 10%. M. catarrhalis must be considered generally resistant to non-protected aminopenicillins since over 90% of these organisms produce beta-lactamases.

Anti-Bacterial Agents↗
PubMed1999

Nationwide survey in Italy of treatment of Streptococcus pyogenes pharyngitis in children: influence of macrolide resistance on clinical and microbiological outcomes. Artemis-Italy Study Group.

Throat swab specimens were obtained from 3,227 children with symptoms of acute pharyngotonsillitis. After 14 to 21 days, a second throat swab specimen was obtained at a follow-up visit. Over 42% of the 934 strains of Streptococcus pyogenes isolated in the primary study were resistant to erythromycin, azithromycin, and clarithromycin. Eradication rates among the 668 patients who entered the follow-up study were as follows: 84.1%, penicillin recipients; 82.7%, cephalosporin recipients; and 71.7%, macrolide recipients. Among patients treated with macrolides, the eradication rate was approximately 80% when the infecting organisms were erythromycin-susceptible and approximately 60% when they were erythromycin-resistant. These results indicate substantial in vitro macrolide resistance among Italian isolates of S. pyogenes. However, at least for a minor self-limiting condition such as acute S. pyogenes pharyngitis, our findings point to a limited overall correlation between in vitro susceptibility (to penicillins, cephalosporins, or macrolides) and eradication in patients treated with these drugs and an even weaker correlation between in vitro resistance (to macrolides) and noneradication in patients receiving macrolide therapy.

Adolescent↗