TY - JOUR
T1 - Antimicrobial susceptibility of Haemophilus influenzae strains isolated from invasive disease in Italy
AU - Cerquetti, Marina
AU - Cardines, Rita
AU - Gufrè, Maria
AU - Mastrantonio, Paola
AU - Ciofi, Marta Luisa
AU - Atti, Degli
AU - Salmaso, Stefania
AU - Carbonari, Patrizia
AU - Nicoletti, Pierluigi
AU - Goglio, Antonio
AU - Moiraghi, Angela Ruggenini
AU - Orecchia, Stefania
AU - Castella, Annalisa
AU - Zotti, Carla
AU - Carraro, Valter
AU - Caola, Iole
AU - Ferro, Antonio
AU - Crovári, Pietro
AU - Giordano, Cristina
AU - Tixi, Pietro
AU - Lemmi, Marina
AU - Bonanni, Paolo
AU - Tomei, Alessia
AU - Pecile, Patrizia
AU - Balocchini, Emanuela
AU - Pecori, Licia
AU - Santonastasi, Francesco
AU - Cafaro, Loredana
AU - Pagano, Vittorio
AU - Barbuti, Salvatore
AU - Chironna, Maria
PY - 2004/12
Y1 - 2004/12
N2 - Objectives: Haemophilus influenzae invasive disease is potentially life threatening and requires prompt antibiotic therapy. The aim of this study was to assess the antimicrobial susceptibility of H. influenzae strains isolated from invasive disease in Italy and to investigate ampicillin-resistant isolates by molecular biology techniques. Materials and methods: One-hundred and seventy-six invasive H. influenzae isolates, collected during 1998-2003, were analysed for susceptibility to ampicillin, azithromycin, chloramphenicol and ciprofloxacin. Ampicillin-resistant isolates were further tested against cefotaxime and imipenem. MICs were determined by Etest and interpreted according to NCCLS criteria. The ampicillin resistance genes, blaTEM and blaROB, were searched for by PCR. Genetic relatedness among ampicillin-resistant isolates was investigated by PFGE. Results: Overall, ampicillin resistance was 10.2% (all β-lactamase producer strains). The prevalence of ampicillin-resistant isolates increased from 6.9% in 1998/1999 to 19% in 2002/2003. Resistance to azithromycin and chloramphenicol was 6.8% and 1.7%, respectively. No strains were resistant to ciprofloxacin. Co-resistance between ampicillin and chloramphenicol and between ampicillin and azithromycin was observed in three and one isolates, respectively. All ampicillin-resistant isolates were susceptible to cefotaxime and imipenem and all harboured the blaTEM gene. PFGE demonstrated that most of the ampicillin-resistant isolates showed little genetic homology. Conclusions: An upward trend in resistance to ampicillin due to β-lactamase production was demonstrated In Italy. According to PFGE results, clonal dissemination of ampicillin-resistant isolates does not occur. Imipenem may represent an appropriate alternative for treatment of H. influenzae invasive disease caused by ampicillin-resistant isolates when third-generation cephalosporins cannot be used.
AB - Objectives: Haemophilus influenzae invasive disease is potentially life threatening and requires prompt antibiotic therapy. The aim of this study was to assess the antimicrobial susceptibility of H. influenzae strains isolated from invasive disease in Italy and to investigate ampicillin-resistant isolates by molecular biology techniques. Materials and methods: One-hundred and seventy-six invasive H. influenzae isolates, collected during 1998-2003, were analysed for susceptibility to ampicillin, azithromycin, chloramphenicol and ciprofloxacin. Ampicillin-resistant isolates were further tested against cefotaxime and imipenem. MICs were determined by Etest and interpreted according to NCCLS criteria. The ampicillin resistance genes, blaTEM and blaROB, were searched for by PCR. Genetic relatedness among ampicillin-resistant isolates was investigated by PFGE. Results: Overall, ampicillin resistance was 10.2% (all β-lactamase producer strains). The prevalence of ampicillin-resistant isolates increased from 6.9% in 1998/1999 to 19% in 2002/2003. Resistance to azithromycin and chloramphenicol was 6.8% and 1.7%, respectively. No strains were resistant to ciprofloxacin. Co-resistance between ampicillin and chloramphenicol and between ampicillin and azithromycin was observed in three and one isolates, respectively. All ampicillin-resistant isolates were susceptible to cefotaxime and imipenem and all harboured the blaTEM gene. PFGE demonstrated that most of the ampicillin-resistant isolates showed little genetic homology. Conclusions: An upward trend in resistance to ampicillin due to β-lactamase production was demonstrated In Italy. According to PFGE results, clonal dissemination of ampicillin-resistant isolates does not occur. Imipenem may represent an appropriate alternative for treatment of H. influenzae invasive disease caused by ampicillin-resistant isolates when third-generation cephalosporins cannot be used.
KW - β-lactamases
KW - Ampicillin resistance
KW - Meningitis
KW - Molecular typing
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U2 - 10.1093/jac/dkh467
DO - 10.1093/jac/dkh467
M3 - Article
C2 - 15486078
AN - SCOPUS:19944432851
VL - 54
SP - 1139
EP - 1143
JO - Journal of Antimicrobial Chemotherapy
JF - Journal of Antimicrobial Chemotherapy
SN - 0305-7453
IS - 6
ER -