Carbapenem-resistant Enterobacteriaceae (CRE) nosocomial infections
Carbapenem-resistant Enterobacteriaceae (CRE) are considered the most important antimicrobial resistant bacteria in human medicine, because they often show resistance to not only broad-spectrum beta-lactam antibiotics including carbapenems, but also to fluoroquinolone or aminoglycoside antibiotics. In the present state that developments of new antibiotics have not made much progress, healthcare professionals have been cautious of the presence of antimicrobial resistant bacteria against carbapenems which are the strongest antibiotics. CRE which exhibit multi-drug resistance are increasing worldwide, so their trends attract global attention.
As reported by media, nosocomial infections of CRE were confirmed in a middle-sized hospital in Kitakyushu on Aug. 11. CRE were isolated from four elderly inpatients and three of them died. At a press conference, the director of the hospital explained that the infectious disease control was insufficient. CRE infections were designated a category V infectious disease under the Infectious Diseases Control Law on Sept. 2014; physicians who make the diagnosis of CRE infections must notify all cases. 1,669 cases including 59 cases of death were notified in a year 2015. Thus, it doesn’t seem that CRE are rare bacterial infections in Japan in these days.
The most effective antibiotic for CRE infections is colistin sulfate: not only a historical antibiotic as both a feed additive and a drug in livestock field, but also the so-called last-resort antibiotic. The designation of colistin sulfate as a feed additive will be canceled as a result of the risk evaluation in the Food Safety Commission of Japan on Apr. 2018, however, it is assumed that CRE infectious trends affect the use of colistin sulfate as a veterinary drug. Therefore, it seems that veterinarians and other concerned parties need to be interested in it.
On the other hand, there is no approval of carbapenem antibiotics for animals. However, in fact, some veterinarians are using them off label. In this case, the treatment is performed empirically, because carbapenem antibiotics are not approved drugs; they have no data base concerning the correct dose of drug, and so on. Furthermore, the amount of use or the occurrence of antimicrobial resistant bacteria is not clear owing to the lack of AMR monitoring system for companion animals at present. It is remarkable that recently Acinetobacter radioresistens with IMP-1 type βlactamase, which has carbapenem resistance and is detected frequently in human medicine, was first isolated from both a dog with cystitis and a cat with conjunctivitis. The effect of isolated bacteria on human medicine is unknown, however, we need to use carbapenem antibiotics for companion animals with much care.
Kimura Y, Miyamoto T, Aoki K, Ishi Y, Harada K, Watarai M, Hataya S:
Analysis of IMP-1 type metallo-β-lactamase-producing Acinetobacter
radioresistens isolated from companion animals,
J Infect Chem 23(9):655-657, 2017.