title: [Notice of first NDM-1 expressing isolates in Turkey and the use of modified Hodge test].
abstract: We read the article entitled "Investigation of the presence of New Delhi metallo- beta-lactamase-1 (NDM-1) by PCR in carbapenem-resistant gram-negative isolates" by Yanık et al. [Mikrobiyol Bul 2013; 47(2):382], with a great interest. Today, gram-negative enteric bacteria expressing NDM-1 are spreading rapidly all over the world and this is of great concern when increasing carbapenem resistance is considered. Yanık et al. reported that there were no NDM-1 positive isolates in their study involving a part of Turkey. It is well-known that the most sensitive indicator related to carbapenem resistance is ertapenem resistance [Perçin et al. Mikrobiyol Bul 2012; 46(4):546]. In their study Yanık et al. used imipenem, meropenem or doripenem instead of ertapenem resistance for screening carbapenem resistance. Thus, carbapenem-resistant strains might be unnoticed in their study. They also used Modified Hodge Test (MHT) for the investigation of carbapenem resistance in the second stage of their study. MHT is known to have a low sensitivity as a screening test for NDM-1 positive strains. To increase its sensitivity, ZnSO4 should be added to the culture medium [Girlich et al. J Clin Microbiol 2012; 50(2):477]. However, this issue was not specified in Yanık et al's study. Thus, this may be another possible cause of failure to detect NDM-1 expressing strains. Yanık et al. reported in their study that NDM-1-producing isolates were not detected in Turkey. However, very recently, four NDM-1 isolates which were not associated with importation from abroad, were reported in a study from Turkey [Alp et al. J Hosp Infect 2013; 84(2):178] and this was the first report of domestic NDM-1 secreting strains in Turkey. In conclusion, there is a need in our country to a carbapenem group antibiotic investigate the presence of NDM-1 positive strains. The use of ertapenem for screening carbapenem resistance and also adding ZnSO4 to MHT for the detection of NDM-1 strains are of great importance.
authors: GATA Haydarpasa Training Hospital, Department of Infectious Disease and Clinical Microbiology, Istanbul, Turkey. drtbpmh@gmail.com.
authors: Mustafa
authors: M
authors: Hatipoğlu
authors: Vedat
authors: V
authors: Turhan
mesh_terms: D015780:Carbapenems / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects* / Q000201:enzymology*; D006801:Humans; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D015780:Carbapenems; D001618:beta-Lactamases