65 research outputs found

    Restaurant outbreak of Legionnaires' disease associated with a decorative fountain: an environmental and case-control study

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    BACKGROUND: From June to November 2005, 18 cases of community-acquired Legionnaires' disease (LD) were reported in Rapid City South Dakota. We conducted epidemiologic and environmental investigations to identify the source of the outbreak. METHODS: We conducted a case-control study that included the first 13 cases and 52 controls randomly selected from emergency department records and matched on underlying illness. We collected information about activities of case-patients and controls during the 14 days before symptom onset. Environmental samples (n = 291) were cultured for Legionella. Clinical and environmental isolates were compared using monoclonal antibody subtyping and sequence based typing (SBT). RESULTS: Case-patients were significantly more likely than controls to have passed through several city areas that contained or were adjacent to areas with cooling towers positive for Legionella. Six of 11 case-patients (matched odds ratio (mOR) 32.7, 95% CI 4.7-infinity) reported eating in Restaurant A versus 0 controls. Legionella pneumophila serogroup 1 was isolated from four clinical specimens: 3 were Benidorm type strains and 1 was a Denver type strain. Legionella were identified from several environmental sites including 24 (56%) of 43 cooling towers tested, but only one site, a small decorative fountain in Restaurant A, contained Benidorm, the outbreak strain. Clinical and environmental Benidorm isolates had identical SBT patterns. CONCLUSION: This is the first time that small fountain without obvious aerosol-generating capability has been implicated as the source of a LD outbreak. Removal of the fountain halted transmission

    Characterization of the first bla CTX-M-14 /ermB-carrying IncI1 plasmid from Latin America

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    Azithromycin represents a valid therapeutic option for gastrointestinal and systemic infections caused by multidrug resistant (MDR) diarrheagenic Escherichia coli, Shigella and Salmonella species. However, acquired macrolide resistance in these species has been increasingly described, mostly related to macrolide modifying enzymes encoded by mph- and erm-type genes. In this study, we characterized the first bla CTX-M-14 /ermB-carrying IncI1 plasmid from Latin America, which was detected in a MDR E. coli clinical isolate from Uruguay. Plasmid pUR-EC07 was a 105,836-bp IncI1 ST80 plasmid harboring bla CTX-M-14, bla TEM-1 and ermB, and characterized by a backbone region of 92,554 bp, and a multi resistance region (MRR) of 13,282 bp, bounded by two directly-oriented IS26 elements, and inserted upstream of ResD. The MRR comprised two nested IS26-composite transposons (Tn6651 and Tn6652). Tn6651 included the ermBL-ermB operon flanked by two IS26 copies in opposite direction. Tn6652 included bla TEM-1 , with an upstream remnant of a Tn3-family transposon, and bla CTX-M-14 , located in a genetic context consisting of ISEcp1 06\u2013IS10\u2013bla CTX-M-14 \u2013IS903D. To the best of our knowledge, pUR-EC07 represents the first IncI1 plasmid harboring ermB and bla CTX-M-14 described in Latin America. Given the wide dissemination of IncI-type plasmids in Salmonella enterica, an important concern is represented by the potential transfer of similar plasmids to strains resistant to ciprofloxacin, which would result in the loss of the three main therapeutic resources

    Description of novel resistance islands harbouring blaCTX-M-2 in IncC type 2 plasmids

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    Objectives: We sequenced two IncA/C plasmids harbouring blaCTX-M-2 in Klebsiella pneumoniae clinical isolates and compared their antibiotic resistance islands. Methods: Transconjugants were obtained from two clinical K. pneumoniae isolates harbouring blaCTX-M-2. Plasmid DNA from transconjugants underwent short-read whole-genome sequencing, reads were assembled, and gaps were closed by PCR and sequencing. Determination of plasmid replicons, antibiotic resistance genes, identification and characterisation of insertion sequence (IS) elements, and comparison with publicly available plasmid sequences were performed. Results: blaCTX-M-2 was located in a complex class 1 integron In35::ISCR1::blaCTX-M-2, inserted in two different transposons designated Tn7057 and Tn7058, that reside in the resistance islands of plasmids pUR-KP0923 and pUR-KP1025, respectively. The general modules of both transposons were In35::ISCR1::blaCTX-M-2\u2013Tn1000-like\u2013Tn2*\u2013ISKpn11-12-13 variable module\u2013\u394Tn21. In Tn7057 there was \u394IS10R\u2013catA2 associated with an additional ISKpn13. Both plasmids belonged to IncC type 2 and ST3. pUR-KP0923 was 167 138 bp in length and had a 37 926-bp resistance island at position 4 (RI-4). Plasmid pUR-KP1025 was 168 128 bp with a RI-4 of 36 222 bp. Conclusion: This report describes the molecular nature of two transposons (Tn7057 and Tn7058) harbouring blaCTX-M-2 that reside in IncC type 2 ST3 plasmids. These transposons mediate resistance to oxyimino-cephalosporins, gentamicin and, in the case of Tn7057, chloramphenicol. CTX-M-2 is an important extended-spectrum \u3b2-lactamase (ESBL) to South American epidemiology. It is remarkable that despite being only two plasmid sequences, the information revealed here could contribute to a better understanding of the resistance islands from IncC type 2 plasmids
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