Biomedical subjects

Giovanni Bonfiglio

Publications and source records attributed to Giovanni Bonfiglio.

4 recordsLinked to original sources

PubMed2003

Effects on adhesiveness and hydrophobicity of sub-inhibitory concentrations of netilmicin.

The effect of sub-inhibitory concentrations (SICs) of netilmicin on bacterial hydrophobicity and adhesiveness to conjunctival cells was investigated. One strain each of Pseudomonas aeruginosa, Pseudomonas spp., Staphylococcus aureus and S. epidermidis was investigated for its susceptibility to netilmicin, its adherence to conjunctival cells and to the effect of hydrocarbon hexadecane before and after treatment with SIC of netilmicin. All of the bacteria tested were susceptible to netilmicin except for Pseudomonas spp. which showed intermediate resistance. Netilmicin-treated Pseudomonas strains exhibited a lower level of hydrophobicity towards n-hexadecane compared with non-treated strains, while netilmicin-treated S. epidermidis and S. aureus showed a slight increase of hydrophobicity. Adherence of the two Pseudomonas strains to conjunctival cells was significantly reduced after growth in the presence of netilmicin, while the adherence of the two staphylococci was only slightly reduced.

Alkanes↗

PubMed2002

Prevalence of extended spectrum beta-lactamases among Enterobacteriaceae: an Italian survey.

The prevalence of extended-spectrum beta-lactamase (ESBL) production by consecutive non-repeated isolates of Enterobacteriaceae was determined over a 6-month period. A total of 8015 strains were isolated from ten Italian laboratories and 509 (6.3%) of these were designated ESBL producers from the results of a double-disk synergy test. Escherichia coli was the most isolated microrganism, followed by Klebsiella pneumoniae and Proteus mirabilis. Providencia stuartii (28.1%) was the most frequently isolated ESBL producer, followed by K. pneumoniae and Enterobacter aerogenes (20.5%). However, amongst all ESBL producers, K. pneumoniae (38.2%) was the most represented followed by P. mirabilis (25.7%). All the strains positive to DD tests were confirmed for the carriage of TEM and SHV genes using colony-blot hybridisation (CH). A total of 447 strains (88.0%) were CH-positive, of which 42.3% hybridised with the TEM-type probe, 30.1% with the SHV-type probe and 15.6% with both probes. In conclusion, our findings indicate that 6.3% of all Enterobacteriaceae tested produced ESBLs, 42.3% of which were TEM-derived enzymes. More than 20% of P. stuartii, K. pneumoniae and E. aerogenes harbour these enzymes. The double-disk test seems to be a useful test to identify ESBL producing strains.

Anti-Bacterial Agents↗

PubMed2002

Epidemiology of bacterial resistance in gastro-intestinal pathogens in a tropical area.

During 1999-2000 a total of 4131 faecal specimens were collected and analysed at the medical centre St. Camille at Ouagadougou. Eight hundred and twenty-six (8.0%) grew significant bacteria. Escherichia coli (35%), Salmonella spp. (15%) and Shigella spp. (10%) were most frequently isolated. A large number of E. coli strains were resistant to aminopenicillins (>90%) and cotrimoxazole (80%); for Yersinia spp the resistance was 80 and 25%, respectively. Norfloxacin was the most active antibiotic but was rarely used. The study showed that it is necessary to create antibiotic-resistance surveillance centres in developing countries so that therapy may be appropriate and the spread of antibiotic resistance to other developed countries via increased emigration may be reduced.

Anti-Bacterial Agents↗

PubMed2002

Recent developments in carbapenems.

Carbapenems are beta-lactam antibiotics characterised by the presence of a beta-lactam ring with a carbon instead of sulfone in the 4-position of the thyazolidinic moiety. The first carbapenem to be utilised in therapy was imipenem, the N-formimidoyl derivative of thienamycin. Imipenem is coadministered with cilastatin, an inhibitor of human renal dehydropeptidase I, as imipenem is hydrolysed by this enzyme. Meropenem was the first carbapenem with a 1-beta-methyl group and 2-thio pyrrolidinyl moiety, which renders this antibiotic stable to renal dehydropeptidase I. Other carbapenems for parenteral administration later discovered include biapenem, panipenem, ertapenem, lenapenem, E-1010, S-4661 and BMS-181139. Carbapenems which are orally administered include sanfetrinem, DZ-2640, CS-834 and GV-129606. Carbapenems have an ultra-broad spectrum of antibacterial activity and stability to almost all clinically relevant beta-lactamases. This differentiates them from all other currently available classes of beta-lactam antibiotics. However, Class B beta-lactamases, along with some rare Class A and D enzymes, are able to hydrolyse these antibiotics. Although Class B enzymes are generally chromosomally-encoded (isolated from Stenotrophomonas maltophilia, Aeromonas spp., Bacillus cereus, Bacteroides fragilis, Flavobacterium spp. and Legionella gormanii), plasmid-metallo-beta-lactamases now are appearing in B. fragilis, Pseudomonas aeruginosa, Acinetobacter baumannii and members of Enterobacteriaceae such as Serratia marcescens and Klebsiella pneumoniae. The number of these enzymes compared to the number of other beta-lactamase types is still low, however, it is likely that they will spread due to the increased selective pressure of carbapenem use. The very broad spectrum of antimicrobial activity associated with a good clinical efficacy and a favourable safety profile makes the carbapenems valuable as 'first-line' antibiotics in initial empirical therapy for the treatment of severe infections.

Bacterial Infections↗