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Patients with systemic lupus erythematosus (SLE) produce autoantibodies against a variety of nuclear antigens including Ki antigen. Although anti-Ki autoantibodies were found in a significant number of SLE patients, the nature of Ki antigen is poorly characterized. By using anti-Ki serum as a probe we have cloned a bovine cDNA directing the synthesis in Escherichia coli of a polypeptide immunologically indistinguishable from the authentic Ki antigen. A homologous human cDNA was also cloned and its nucleotide sequence predicted the entire primary structure of a novel nuclear protein with a molecular weight of 29 508 and with highly hydrophilic and weakly acidic character. The gene is highly conserved not only in the coding region but also in the 3'-untranslated region. The bacterially produced Ki antigen would be valuable for diagnosis of SLE.

Forty clinical isolates of multidrug-resistant Pseudomonas aeruginosa were obtained in a medical setting in Hanoi, Vietnam. Whole genomes of all 40 isolates were sequenced by MiSeq (Illumina), and phylogenic trees were constructed from the single nucleotide polymorphism concatemers. Of these 40 isolates, 24 (60.0%) harbored metallo-␤-lactamase-encoding genes, including bla IMP-15 , bla IMP-26 , bla IMP-51 , and/or bla NDM-1 . Of these 24 isolates, 12 harbored bla IMP-26 and belonged to sequence type 235 (ST235). Escherichia coli expressing bla IMP-26 was significantly more resistant to doripenem and meropenem than E. coli expressing bla IMP-1 and bla IMP-15 . IMP-26 showed higher catalytic activity against doripenem and meropenem than IMP-1 and against all carbapenems tested, including doripenem, imipenem, meropenem, and panipenem, than did IMP-15. These data suggest that clinical isolates of multidrug-resistant ST235 P. aeruginosa producing IMP-26 with increased carbapenem-hydrolyzing activities are spreading in medical settings in Vietnam.

Spondylodiscitis caused by Parvimonas micra, a rarely reported infection, might be under-detected using conventional methods. This report of the detection and treatment of two cases of spondylodiscitis due to P. micra and review of the literature indicates that the use of gene sequencing methods might improve the accuracy of diagnosing this infection.

d IMP-type metallo-␤-lactamase enzymes have been reported in different geographical areas and in various Gram-negative bacteria. However, the risk factors and epidemiology pertaining to IMP-type metallo-␤-lactamase-producing Enterobacter cloacae (IMP-producing E. cloacae) have not been systematically evaluated. We conducted a retrospective, matched case-control study of patients from whom IMP-producing E. cloacae isolates were obtained, in addition to performing thorough molecular analyses of the clinically obtained IMP-producing E. cloacae isolates. Unique cases with IMP-producing E. cloacae isolation were included. Patients with IMP-producing E. cloacae were matched to uninfected controls at a ratio of 1 to 3. Fifteen IMP-producing E. cloacae cases were identified, with five of the isolates being obtained from blood, and they were matched to 45 uninfected controls. All (100%) patients from whom IMP-producing E. cloacae isolates were obtained had indwelling devices at the time of isolation, compared with one (2.2%) uninfected control. Independent predictors for isolation of IMP-producing E. cloacae were identified as cephalosporin exposure and invasive procedures within 3 months. Although in-hospital mortality rates were similar between cases and controls (14.3% versus 13.3%), the in-hospital mortality of patients with IMP-producing E. cloacae-caused bacteremia was significantly higher (40%) than the rate in controls. IMP-producing E. cloacae isolates were frequently positive for other resistance determinants. The MICs of meropenem and imipenem were not elevated; 10 (67%) and 12 (80%) of the 15 IMP-producing E. cloacae isolates had a MIC of <1 g/ml. A phylogenetic tree showed a close relationship among the IMP-producing E. cloacae samples. Indwelling devices, exposure to cephalosporin, and a history of invasive procedures were associated with isolation of IMP-producing E. cloacae. Screening for carbapenemase production is important in order to apply appropriate clinical management and infection control measures.

MethodsTwenty-seven clinical isolates of carbapenem-resistant Klebsiella pneumoniae with MICs ≥4 mg/L for imipenem or meropenem were obtained from inpatients in a hospital in Vietnam. Antimicrobial susceptibility tests and whole genome sequencing were performed. Multilocus sequence typing and the presence of drug resistant genes were determined and a maximum-likelihood phylogenetic tree was constructed by SNP alignment of whole genome sequencing data.ResultsAll the isolates harbored one of genes encoding carbapenemases, including KPC-2, NDM-1, NDM-4 and OXA-48. Of the isolates, 13 were resistant to arbekacin with MICs ≥256 mg/L and to amikacin with MICs ≥512 mg/L. These isolates harbored a gene encoding a 16S rRNA methylase, either RmtB or RmtC. Eighteen and 4 isolates belonged to international clones, ST15 and ST16, respectively. None of the isolates had colistin-resistant factors.ConclusionCarbapenem-resistant K. pneumoniae isolates belonged to international clones spread in a medical setting in Vietnam, and that these isolates harbored genes encoding various combinations of carbapenemases and 16S rRNA methylases. This is the first report of KPC-2, NDM-4 and OXA-48 producers in a medical setting in Vietnam.

b Forty-nine clinical isolates of multidrug-resistant Acinetobacter baumannii were obtained from 12 hospitals in 7 prefectures throughout Japan. Molecular phylogenetic analysis revealed the clonal spread of A. baumannii sequence type 208 (ST208) and ST455 isolates harboring the armA gene and ST512 harboring the armA and bla OXA-72 genes. These findings show that A. baumannii isolates harboring armA are disseminated throughout Japan, and this is the first report to show that A. baumannii strains harboring bla OXA-72 and armA are emerging in hospitals in Japan. Multidrug-resistant Acinetobacter baumannii has become a threatening nosocomial pathogen worldwide (1). Most strains of this species develop resistance to carbapenems by mechanisms associated with carbapenem-hydrolyzing class D OXA-type ␤-lactamases (CHDLs) (2). The overproduction of intrinsic chromosomal OXA-51-like enzymes and the production of acquired OXA-23-, OXA-24/40-, OXA-58-, OXA-143-, and OXA-235-like enzymes have been associated with carbapenem-resistant A. baumannii isolates (3-5). The gene bla , one of the bla OXA-40-like genes, was first identified in an A. baumannii strain isolated in 2004 in Thailand (GenBank accession no. AY739646). Since then, Acinetobacter spp. harboring bla have been reported in Brazil (6), China (7), Colombia (8), Croatia (9), France (10), Italy (11), Lithuania (12), South Korea (13), Spain (14), Taiwan (15), and the United States (16).The armA gene, encoding a 16S rRNA methylase that confers aminoglycoside resistance, was initially identified in Citrobacter freundii in 2002 in Poland (17), and it was later detected in several including A. baumannii, in Africa, Asia, Europe, and North America (18).From July to December 2012, the BML Biomedical Laboratories R&D Center (Kawagoe, Saitama, Japan) acquired 16,343 isolates of Acinetobacter spp. from 3,015 medical settings located in 47 prefectures throughout Japan. These included 49 isolates of multidrug-resistant A. baumannii obtained from 49 patients in 12 hospitals located in 7 prefectures in Japan (see Fig. S1 in the supplemental material). Of these 49 isolates, 41 were from respiratory tract, 7 from urinary tract, and 1 from blood samples. The multidrug-resistant A. baumannii strains were defined as having MICs of Ն16 g/ml to imipenem/meropenem, Ն32 g/ml to amikacin, and Ն8 g/ml to levofloxacin/gatifloxacin or Ն4 g/ml to ciprofloxacin, according to the criteria of the Japanese Nosocomial Infection Surveillance System (JANIS) of the Japanese Ministry of Health, Labor and Welfare (MHLW). The species were determined by the Vitek system (bioMérieux SA, Marcy l'Etoile, France) and by the sequences of the 16S rRNA, gyrB, and bla OXA-51-like genes.The MICs were determined using the microdilution method, as described in the guidelines of the Clinical and Laboratory Standards Institute (19).Whole genomes of the 49 multidrug-resistant isolates were extracted by DNeasy blood and tissue kits (Qiagen, Tokyo, Japan) and sequenced by MiSeq (Illumina, San Diego, CA).More-than-10-fol...