[Show abstract][Hide abstract]ABSTRACT: To determine the prevalence of class A extended spectrum β-lactamases (ESBL)-producing Escherichia coli and Klebsiella spp., and to investigate clonality among ESBL-producing isolates of nosocomial and community infections.
The study involved 354 nosocomial infections samples and 992 community infections samples, obtained between 2003 and 2006 at Caxias do Sul, RS. The detection of ESBL was performed by the disk-diffusion test. Presence of blaCTX-M, blaSHV and blaTEM β-lactamase genes was evaluated by PCR, and genomic typing was determined by pulsed-field gel electrophoresis analysis.
Higher frequency of ESBL-producing isolates were detected among nosocomial samples of E. coli (6.7%) and Klebsiella (43.7%), than those obtained from community infections (0.4% and 2.6%). blaTEM and blaCTX were the most prevalent ESBL gene families in both E. coli and Klebsiella isolates. Different pulsotypes were obtained among ESBL-producing E. coli and 11 clones for Klebsiella spp., which occurred over the years and in different hospital wards. Among ESBL-producing K. pneumoniae, 74.3% transferred ESBL genes by conjugation and exhibited concomitant decreased aminoglycosides susceptibility.
ESBL-producing E. coli, and especially K. pneumoniae are essentially a nosocomial problem, and their dissemination to the community is relatively limited. The great genetic variability observed among ESBL-producing bacteria indicates polyclonal spread and high transference of ESBL genes between bacteria in the hospital environment. This information is of paramount importance for nosocomial infection control.
Full-text · Article · Apr 2011 · The Brazilian journal of infectious diseases: an official publication of the Brazilian Society of Infectious Diseases
[Show abstract][Hide abstract]ABSTRACT: Aeromonas were isolated from 27 (6.6%) of 408 patients admitted with acute gastroenteritis in two hospitals at Rio Grande do Sul, Brazil. Isolates were classified as A. hydrophila (51.8%), A. caviae (40.8%), and A. veronii biotype sobria (7.4%). The highest prevalence of Aeromonas associated infections occurred in lactants and children. Virulence genes (aerA -aerolysin/hemolysin, ahpA -serine-protease, satA glycerophospholipid-cholesterol acyltransferase, lipA -lipase, and ahyB -elastase) and virulence factors (hemolytic, proteolitic, lipolitic activities, and biofilm formation) were identified in most A. hydrophila and A. veronii biotype sobria isolates, with lower frequencies on A. caviae. All Aeromonas isolates were resistant to ampicillin, ticarcillin/clavulanic acid, cephalotin, and cephazolin, and most of them (> 70%) exhibited resistance to imipenem, carbenicillin, amoxillin/sulbactan, and piperacillin. Multiple-resistance, more than four antibiotics, was evidenced in 29.6% of the isolates. The most efficient antibiotics were the quinolones (ciprofloxacin and norfloxacin), and the aminoglycosides (amikacin and netilmicin).
Full-text · Article · Oct 2007 · Brazilian Journal of Microbiology