New Delhi metallo-β-lactamase-1 in carbapenem-resistant Salmonella strain, China.

摘要: To the Editor: Carbapenem resistance in Enterobacteriaceae can occur through production of carbapenem-hydrolyzing enzymes such as New Delhi metallo-β-lactamase-1 (NDM-1) (1). In recent years, plasmid-mediated NDM-1 has spread rapidly worldwide and into multiple species, Klebsiella pneumoniae Escherichia coli (2). NDM-1 been reported 2 strains Salmonella spp., which were isolated from feces urine specimens during screening for multidrug-resistant bacteria patients India (3,4). We report isolation 1 community-acquired NDM-1–bearing strain a child with acute diarrhea. The was an 11-month-old girl at Lishui Central Hospital, Zhejiang Province, China, on July 25, 2012. Six days before admission, fever ≤40°C, accompanied by cough, developed patient. Four physical examination showed fine rales both lungs. The leukocyte count 8,900 cells/µL, 80% neutrophils. No obvious abnormalities found chest radiograph. The patient given diagnosis bronchitis, condition treated parenteral cefoxitin 3 piperacillin/tazobactam day, but persisted. Two diarrhea (4–5 times/day loose containing mucus blood) developed. On admission fecal analysis 3–4 leukocytes 1–3 erythrocytes per high-power field. A sp. obtained identified S. enterica subsp. serovar Stanley serotyping local Centers Disease Control Prevention. The then bacterial enteritis received intravenous azithromycin latamoxef. Fever resolved over next days. fifth day hospitalization, culture negative spp. discharged. At follow-up visit months later, or other carbapenem-resistant not samples her grandmother brother, who lived her. The family had traveled to any country year, including countries high prevalence producers. living small rural village southern China did have special diet. She healthy hospitalization fever. born cesarean section contacts hospitalized patients. MICs antimicrobial drugs determined agar dilution interpreted using revised Clinical Laboratory Standards Institute breakpoints (5). resistant all β-lactam tested, cephalosporins carbapenems, susceptible chloramphenicol, ciprofloxacin, tetracycline, fosfomycin, MICs 4 µg/mL (Table). Table Antimicrobial drug susceptibility transconjugants metallo-β-lactamase-1, China A modified Hodge test result weakly positive. Production metallo-β-lactamase detected imipenem-EDTA double-disk synergy test. Carbapenamase-encoding genes, blaKPC-2, blaVIM, blaIMP, blaSPM-1, blaGIM-1, blaSIM-1, PCR described (2). Only blaNDM-1 gene (with primers 5′-GGCGGAATGGCTCATCACGA-3′ 5′-CGCAACACAGCCTGACTTTC-3′). product sequence consistent that (GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"FN396876","term_id":"255031061","term_text":"FN396876"}}FN396876). Conjugation experiments conducted (6). could be transferred E. C600 Rifr K. 13883 frequencies transconjugant ≈1.0 × 104 4.0 107 cells, respectively, after exposure 15 min. Plasmid DNA extracted Plasmid Midi Kit (QIAGEN, Hilden, Germany) according manufacturer’s instructions. Electrophoresis donor same plasmid profile; contained ≈140-kb plasmid. PCR-based method replicon typing (7) indicated belonged incompatibility group IncA/C. Experiments stability transconjugants, Wang et al. Twenty colonies randomly selected every 2–15. lost carbapenem resistance; these collected second ninth passage, respectively. Plasmids blaNDM-1were present colonies. 14 passage. Although shown increased quinolones, carbapenems is rare (3,4,8,9). Because emerging traditionally recommended agents, increasingly used treatment invasive infections children (10). infection cured azithromycin. This indicates ongoing strains. If one considers conjugation frequency IncA/C would conclude it might increase resistance. Prompt recognition initiation appropriate control measures are essential avoid organisms.