RESUMO
Four isolates of a rapidly growing Mycobacterium species had a mycolic acid pattern similar to that of Mycobacterium smegmatis, as determined by HPLC analyses. Three of the isolates were from footbath drains and a sink at a nail salon located in Atlanta, GA, USA; the fourth was obtained from a granulomatous subdermal lesion of a female patient in Venezuela who was undergoing mesotherapy. By random amplified polymorphic DNA electrophoresis and PFGE of large restriction fragments, the three isolates from the nail salon were shown to be the same strain but different from the strain from the patient in Venezuela. Polymorphisms in regions of the rpoB, hsp65 and 16S rRNA genes that were shown to be useful for species identification matched for the two strains but were different from those of other Mycobacterium species. The 16S rRNA gene sequence placed the strains in a taxonomic group along with Mycobacterium frederiksbergense, Mycobacterium hodleri, Mycobacterium diernhoferi and Mycobacterium neoaurum. The strains produced a pale-yellow pigment when grown in the dark at the optimal temperature of 35 degrees C. Biochemical testing showed that the strains were positive for iron uptake, nitrate reduction and utilization of d-mannitol, d-xylose, iso-myo-inositol, l-arabinose, citrate and d-trehalose. The strains were negative for d-sorbitol utilization and production of niacin and 3-day arylsulfatase, although arylsulfatase activity was observed after 14 days. The isolates grew on MacConkey agar without crystal violet but not on media containing 5 % (w/v) NaCl or at 45 degrees C. They were susceptible to ciprofloxacin, amikacin, tobramycin, cefoxitin, clarithromycin, doxycycline, sulfamethoxazole and imipenem. The name Mycobacterium cosmeticum sp. nov. is proposed for this novel species; two strains, LTA-388(T) (=ATCC BAA-878(T)=CIP 108170(T)) (the type strain) and 2003-11-06 (=ATCC BAA-879=CIP 108169) have been designated, respectively, for the strains of the patient in Venezuela and from the nail salon in Atlanta, GA, USA.
Assuntos
Indústria da Beleza , Técnicas Cosméticas , Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Mycobacterium/isolamento & purificação , Unhas , Dermatopatias Bacterianas/microbiologia , Proteínas de Bactérias/genética , Técnicas de Tipagem Bacteriana , Chaperonina 60 , Chaperoninas/genética , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/isolamento & purificação , DNA Ribossômico/química , DNA Ribossômico/isolamento & purificação , RNA Polimerases Dirigidas por DNA/genética , Feminino , Genes de RNAr , Humanos , Injeções Subcutâneas , Microinjeções , Dados de Sequência Molecular , Mycobacterium/química , Mycobacterium/fisiologia , Ácidos Micólicos/análise , Ácidos Micólicos/isolamento & purificação , Hibridização de Ácido Nucleico , Filogenia , Pigmentos Biológicos/biossíntese , Polimorfismo Genético , Polimorfismo de Fragmento de Restrição , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA , Temperatura , Estados Unidos , VenezuelaRESUMO
BACKGROUND: Among members of the family Enterobacteriaceae, the production of plasmid-mediated extended-spectrum beta-lactamases (ESbetaLs) has emerged as an important mechanism of the resistance to beta-lactams. METHODS: The molecular basis of extended-spectrum beta-lactamase in 48 strains of Klebsiella pneumoniae, recovered from neonatal patients with nosocomial septicemia during an outbreak that occurred in November 2000 at a Neonatal Intensive Care Unit of The Andes University Hospital in Venezuela, were investigated. RESULTS: The isolates were resistant to expanded-spectrum cephalosporins, aztreonam, gentamicin, kanamycin, tetracycline, and chloramphenicol, but remained susceptible to cefoxitin, imipenem, amikacin, and tobramycin. Production of ESbetaL activity was confirmed by restoring susceptibility to ceftazidime in the presence of clavulanic acid. All isolates harbored an 87-kilobase plasmid. Analysis of the outer membrane protein patterns did not reveal relevant changes of the porins profile. All resistance markers were transferable to Escherichia coli by conjugation and were lost en bloc after treatment with acridine orange. Isoelectric focusing for beta-lactamases was performed on transconjugants, obtaining 2 bands with isoelectric points of 5.4 and 8.2. Genes encoding both enzymes are located on the single, self-transferable 87-kilobase plasmid pKAM542. Analysis of the plasmid by hybridization revealed the presence of both blaTEM and blaSHV determinants. Cloning and sequencing identified them as blaTEM-1 and blaSHV-5, respectively; the latter was responsible for the ESbetaL activity among nosocomial isolates of K pneumoniae. CONCLUSIONS: Microbiologists, epidemiologists, and clinicians must be aware of potential ESbetaL-encoding organisms to assess proper antimicrobial managements and effective infection controls.
