Bacteriology-Hygiene Unit, Assistance Publique-Hôpitaux de Paris, Bicêtre Hospital, Le Kremlin-Bicêtre, France.
EA7361, Université Paris Sud, Université Paris Saclay, LabEx Lermit, Faculty of Medicine, Le Kremlin-Bicêtre, France.
Antimicrob Agents Chemother. 2017 Aug 24;61(9). doi: 10.1128/AAC.00818-17. Print 2017 Sep.
OXA-244 is a single-point-mutant derivative of OXA-48 displaying reduced carbapenemase activity. Here, we report the microbiological features of seven OXA-244-producing isolates. Only one isolate grew on ChromID Carba Smart medium (bioMérieux), but six of the seven isolates grew on ChromID extended-spectrum-β-lactamase (ESBL) medium (bioMérieux), as they coproduced an ESBL and/or a plasmid-encoded cephalosporinase. The production of a carbapenemase was detected in 57.1%, 71.4%, 71.4%, and 100% of the isolates using the Carba NP test, the Rapidec Carba NP test (bioMérieux), a matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) hydrolysis assay (Bruker), and the OXA-48 K-SeT assay (Coris BioConcept), respectively. Our results indicate that OXA-244-producing isolates are difficult to detect, which may lead to their silent spread.
OXA-244 是 OXA-48 的单点突变衍生株，其碳青霉烯酶活性降低。在此，我们报告了 7 株产 OXA-244 分离株的微生物学特征。只有一株分离株在 ChromID Carba Smart 培养基（生物梅里埃）上生长，但这 7 株分离株中的 6 株在 ChromID 扩展谱β-内酰胺酶（ESBL）培养基（生物梅里埃）上生长，因为它们同时产生 ESBL 和/或质粒编码的头孢菌素酶。使用 Carba NP 试验、Rapidec Carba NP 试验（生物梅里埃）、基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS）水解试验（布鲁克）和 OXA-48 K-SeT 试验（Coris BioConcept），分别在 57.1%、71.4%、71.4%和 100%的分离株中检测到碳青霉烯酶的产生。我们的结果表明，产 OXA-244 的 分离株难以检测，这可能导致其沉默传播。
