Ertapenem

Some bacteria from the Enterobacteriaceae family are showing a significant capability to disseminate β-lactams resistance mechanisms among them, and these same mechanisms can be carried out from the hospital environment to superficial water. The aim of this study was to evaluate different phenotypic methods for the detection β-lactamases production by enterobacteria isolated from the anthropogenic environment: hospital wastewater and from a stream that cross the city of Porto Alegre. The applied tests were the modified Hodge test (MHT) and phenotypic tests with the following inhibitors: carbapenemase-phenylboronic acid (APB), metallo-β-lactamase-EDTA, AmpC β-lactamase-cloxacillin, and the confirmatory test for extended-spectrum β-lactamase (ESBL)-clavulanic acid. For this evaluation, 131 isolates were initially subjected to antibiogram using the following antimicrobials: cefotaxime (30 µg), cefpodoxime (10 μg), ceftazidime (30 µg), ertapenem (10 μg), meropenem (10 μg), and aztreonam (30 μg).

Outpatient parenteral antimicrobial therapy (OPAT) programs are a current and widely spread trend in clinical practice because of it´s a cost-effective option, it´s associated with a greater comfort for the patient, a lower risk of nosocomial complications and an important cost saving for the health care system. OPAT is used for treating a wide range of infections, including skin and soft tissue infections, osteoarticular infections, bacteraemia, endocarditis and complex intra-abdominal and urinary tract infections, even in presence of multiresistant microorganisms. Correct choice of antimicrobial agent and adequate patient selection are crucial for reaching therapeutic success and avoiding readmissions, treatment prolongation or treatment-related toxicity. The optimal antimicrobial for OPAT must be highly effective, have a long half-life and an adequate spectrum of action. Ceftriaxone and teicoplanin are currently the most prescribed antibiotics for OPAT, though daptomycin and ertapenem are also on the rise, due to their high efficiency, safety and wide spectrum of action.

A rapid, practical, and accurate identification of carbapenemase-producing Enterobacteriaceae isolates is crucial for the implementation of appropriate infection control measures and proper treatment of the infections. For this purpose, a large number of phenotypic test methods have been developed, although none has 100% sensitivity and specificity. Variations in sensitivity and specificity of these tests based on the type of beta-lactamase enzymes carried by that isolates might result in differences between regions and countries. The aim of this study was to compare the performances of widely used modified Hodge test (MHT) and Carbapenemase Nordmann-Poirel (Carba NP) test in the detection of carbapenemases in Enterobacteriaceae family members. A total of 65 Enterobacteriaceae isolates (43 blaOXA-48, 10 blaVIM, 9 blaIMP, 1 blaNDM-1, 1 blaKPC-2 and 1 blaOXA-48+blaVIM carrying strains) that showed decreased sensitivity to at least one carbapenem (ertapenem, imipenem or meropenem), and carriage of carbapenemase gene confirmed by polymerase chain reaction (PCR), were included in the study.

We compared the activity of the carbapenems, ertapenem, meropenem, and imipenem against 180 isolates of rapidly growing mycobacteria (RGM)and 170 isolates ofNocardiausing the Clinical and Laboratory Standards Institute (CLSI) guidelines. A subset of isolates was tested using the E-test. Susceptibility of the ertapenem and meropenem was limited and less than imipenem for the RGM. Analysis of major and minor discrepancies revealed >90% of the isolates ofNocardiahad higher MICs in broth than with E-test in contrast to lower broth MICs seen in >80% of the RGM.Imipenem remains the most active carbapenem against RGM includingM. abscessussubsp.abscessus ForNocardiait was only significantly more active forN. farcinica.Although there may be utility in testingNocardiaagainst the newer carbapenems, they should not be routinely tested against the RGM. Testing by E-test is not recommended by the Clinical Laboratory Standards Institute (CLSI).