INTRODUCTIONImipenem and meropenem are treatment of choice for extended-spectrum betalactamase (ESBL)-positive gram-negative bacteraemia. They may select for carbapenemresistant Acinetobacter baumannii and Pseudomonas aeruginosa; ertapenem may not do so as it is inactive against these bacteria. Clinical efficacy of ertapenem in ESBL-producing gramnegative bacteraemia is limited.

MATERIALS AND METHODSRetrospective study of patients with ESBL-positive gram-negative bacteraemia treated with ertapenem was undertaken.

RESULTSForty-seven patients with multidrug-resistant gram-negative bacteraemia (79% produced ESBL) were treated with ertapenem for a median duration of 11 days. The median age was 70 years. Septic shock occurred in 19% and mechanical ventilation was needed in 17%. Klebsiella pneumoniae comprised 53% and Escherichia coli 26%. Urinary infection accounted for 61% and hepatobiliary 15%. Favourable clinical response occurred in 96%. Attributable mortality was 4%.

CONCLUSIONErtapenem is promising in culture-guided step-down therapy of ESBL-positive gram-negative bacteraemia.

Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents ; pharmacology ; therapeutic use ; Bacteremia ; drug therapy ; etiology ; Drug Resistance, Multiple, Bacterial ; Escherichia coli ; drug effects ; enzymology ; Escherichia coli Infections ; drug therapy ; microbiology ; Female ; Gram-Negative Bacteria ; drug effects ; enzymology ; Gram-Negative Bacterial Infections ; drug therapy ; microbiology ; Humans ; Klebsiella Infections ; drug therapy ; microbiology ; Klebsiella pneumoniae ; drug effects ; enzymology ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Retrospective Studies ; Urinary Tract Infections ; complications ; drug therapy ; beta-Lactamases ; biosynthesis ; beta-Lactams ; pharmacology ; therapeutic use

Metallo-beta-lactamase (MBL) production usually results in high-level resistance to most beta-lactams, and a rapid spread of MBL producing major gram-negative pathogens is a matter of particular concern worldwide. However, clinical data are scarce and most studies compared MBL producer (MP) with MBL non-producer (MNP) strains which included carbapenem susceptible isolates. Therefore, we collected clinical data of patients in whom imipenem-nonsusceptible Pseudomonas aeruginosa (PA) and Acinetobacter baumannii (AB) were isolated from sputum or urine, and investigated MBL production and the risk factors related with MBL acquisition. The antimicrobial susceptibility patterns were also compared between MPs and imipenem-nonsusceptible MNPs (INMNP). Among the 176 imipenem-nonsusceptible isolates, 12 MPs (6.8%) were identified. There was no identifiable risk factor that contributed to the acquisition of MPs when compared to INMNPs, and case-fatalities were not different between the two groups. The percentage of susceptible isolates was higher among MPs for piperacilin/tazobactam and fluoroquinolones while that of ceftazidime was higher in INMNPs (p < 0.05). As regards to aztreonam, which has been known to be a uniquely stable beta-lactam against MBLs, susceptibility was preserved in only two isolates (16.7%) among MPs, and was not higher than that of INMNPs (23.2%). In conclusion, the contribution of MBLs to imipenem non-susceptibility in PA/ABs isolated from sputum and urine was relatively limited, and there was no significant risk factor associated with acquisition of MPs compared with INMNPs. However, limited susceptibility to aztreonam implies that MPs may hold additional resistance mechanisms, such as extended spectrum beta-lactamases, AmpC beta-lactamases, or other non-enzymatic mechanisms.
Adult ; Aged ; Aged, 80 and over ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Child ; Child, Preschool ; Electrophoresis, Gel, Pulsed-Field ; Female ; Gram-Negative Bacteria/drug effects/*enzymology/isolation & purification ; Gram-Negative Bacterial Infections/drug therapy/enzymology/microbiology ; Humans ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Republic of Korea ; Sputum/*microbiology ; Urine/*microbiology ; beta-Lactam Resistance ; beta-Lactamases/*metabolism

OBJECTIVETo analyze the characteristic of bacterial infections, and the relationship between antibiotics treatment and bacterial infections after liver transplantation, and to prevent antibiotic-resistant bacterial infections.

METHODS86 liver transplant recipients were retrospected. Different indexes including limited daily dose, the frequency of medication, drug use index were used to evaluate the rationality of the use of antibiotics, three-dimensional test was used to explore extended-spectrum beta-lactamase and AmpC enzyme of Gram-negative bacteria.

RESULTSThe major pathogens of infection after liver transplantation were Enterococcus faecalis, Enterobacter cloacae, fungi and E. coli. Pre-operative antibiotic utilization rate was 83.7%, it was mainly a single use of antibiotics; After- operative antibiotic usage was 100.0%, it was mainly joint use of two or three antibiotics; The top 3 antibiotics used were cephalosporins, the combined enzyme inhibitors and penicillin. Antibiotics with drug utilization index (DUI) more than 1.1 included ampicillin and Lalin proxy. 43.3% and 31.8% of Gram -Negative bacteria produced ESBLs and AmpC, respectively, while 21.3% Gram -Negative bacteria produced two enzymes.

CONCLUSIONThere is high incidence of bacterial infections after liver transplantation. The use of antibiotics is high dose, high-frequency and reasonable; High resistance of bacterial infections was prone to develop and the prevention of the high resistance of bacterial infections is very important.

Adolescent ; Adult ; Aged ; Anti-Bacterial Agents ; administration & dosage ; therapeutic use ; Bacterial Infections ; drug therapy ; etiology ; microbiology ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Gram-Negative Bacteria ; drug effects ; enzymology ; isolation & purification ; Gram-Positive Bacteria ; drug effects ; enzymology ; isolation & purification ; Humans ; Infant ; Liver Transplantation ; adverse effects ; methods ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Postoperative Complications ; drug therapy ; epidemiology ; microbiology ; Retrospective Studies ; Young Adult ; beta-Lactamases ; biosynthesis