[Show abstract][Hide abstract] ABSTRACT: Prevalence of H. pylori infection was determined using cultures of gastric biopsy samples of patients attended at the academic hospital of the Federal University of Paraná, Curitiba, Paraná, Brazil. Molecular methods were used to characterize the cagA and vacA genes from bacterial isolates associated with different diseases presented by patients. Out of a total of 81, forty-two gastric biopsy samples tested were positive for H. pylori, with a prevalence of 51.9%. No significant difference was found with regard to the gender (p=0.793) and age (p=0.183) of the patients. Genotype s1m1 vacA gene was found in 67% of the cases of peptic ulcer investigated (p=1.0), despite the limited number of patients with this disease (n=3). A correlation between the presence of less virulent strains (s2m2) and reflux esophagitis was found in the majority of the cases (45%), but without statistical significance. An association between the prevalence of cagA gene, found in 92% of isolates, and peptic ulcer was not observed (p=1.0), suggesting that this gene cannot be considered a specific marker of severity in our environment. The results reinforce the importance of conducting regional studies and the need to characterize H. pylori virulence genes associated with different diseases.
Full-text · Article · Oct 2011 · Brazilian Journal of Microbiology
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to evaluate the susceptibility to cefepime of a large group of ESBL- producing enterobacteria recently isolated in a Brazilian teaching hospital . The study included 280 strains of ESBL-producing enterobacteria, isolated between 2005 and 2008. The presence of the genes blaCTX-M, blaTEM and blaSHV was determined by PCR and confirmed by nucleotide sequencing. Susceptibility testing for cefepime was performed by disc-diffusion, agar dilution method and E-test®. Among the isolates, 34 (12.1%) presented a cefepime inhibition zone > 21 and MIC < 8 mg/L by agar dilution and E-strip methods. The use of cefepime for the treatment of infections caused by ESBL-producing bacteria has been controversial. Some studies of PD/PK show the probability of achieving the required PD parameters for cefepime, when the MICs were < 8 mg/L, whereas others have reported therapeutic failure with the same MIC. Additional data is essential to come to terms about the report and treatment with cefepime in ESBL-producing organisms especially when these microorganisms are isolated from sterile sites and from critically ill patients.
Preview · Article · Apr 2011 · The Brazilian journal of infectious diseases: an official publication of the Brazilian Society of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: In the last few years, carbapenem-resistant Acinetobacter baumannii isolates (CR-AB) have been identified worldwide. The first description of OXA-23-producing A baumannii in Brazil was from the city of Curitiba in 2003. The aim of the present study was to evaluate the persistence and dissemination of the first OXA-23-producing A baumannii clone isolated from patients in Hospital de Clinicas, Curitiba, Brazil.
An antimicrobial susceptibility profile of the isolates was determined by the standard agar dilution method. Molecular detection of beta-lactamase genes was done by polymerase chain reaction. The clonal relationship of the isolates was analyzed by pulsed-field gel electrophoresis (PFGE). Epidemiologic and clinical features were evaluated as well.
Genotypic analysis of 172 CR-AB isolates by PFGE identified 3 distinct major PFGE clusters (A, B, and C, accounting for 36, 69, and 65 isolates, respectively). All isolates carried the bla(OXA-23)-like gene and were multidrug-resistant, but were susceptible to tigecycline and polymixin B. The mortality rate related to CR-AB infection was 45.4%, and ventilator-associated pneumonia and bloodstream infections were the most frequent clinical manifestations.
The presence of 3 clones among the CR-AB isolates suggests that cross-transmission was the main mechanism responsible for dissemination of OXA-23 producers. PFGE pattern A was genotypically similar to that of the first OXA-23-producing A baumannii clone identified in Curitiba in 1999. This clone persisted in the same hospital until April 2004. The presence of the bla(OXA-)23-like gene was the main mechanism associated with carbapenem resistance among the isolates studied.
Full-text · Article · May 2010 · American journal of infection control
[Show abstract][Hide abstract] ABSTRACT: The antibacterial activity of plant extracts obtained from Bixa orellana L., Chamomilla recutita L., Ilex paraguariensis A. St.-Hil., Malva sylvestris L., Plantago major L. and Rheum rhaponticum L. has been evaluated against two reference strains and eleven clinical isolates of Helicobacter pylori. All the plant species chosen are used in popular Brazilian cuisine and folk medicine in the treatment of gastrointestinal disorders. Initial screening was made by the disk diffusion test and then minimum inhibitory concentration was determined by the agar dilution method. The results presented in this work demonstrated that among the plant preparations analyzed, B. orellana L., C. recutita L., I. paraguariensis A. St.-Hil. and M. sylvestris L. were capable of inhibiting the in vitro growth of H. pylori.
[Show abstract][Hide abstract] ABSTRACT: The main objectives of this study are to evaluate the resistance rates of Streptococcus pneumonia to penicillin G, ceftriaxone and vancomycin in patients with meningitis; to analyze possible risk factors to the antimicrobian resistance; to describe the serotypes detected and to suggest an initial empirical treatment for meningitis. The sensitiveness and serotypes of all isolated S. pneumoniae of patients with acute bacterial meningitis received by the Paraná State Central Laboratory from April 2001 to august 2002 have been evaluated. One hundred S. pneumoniae have been isolated, of which 15% were resistant to penicillin, 1% to cephalosporin and 0% to vancomycin. The serotypes most found were 14 (19%), 3 and 23F (10% each). When only the resistant serotypes were analyzed, the most prevalent was the 14 with 44%. The risk factors found in relation to the S. pneumoniae resistance were: age under one year old (p=0.01) and previous use of antibiotic (p=0.046). The resistance rates found, which were moderate to penicillin, low to cephalosporin and neutral to vancomycin, suggest the isolated use of a 3rd generation cephalosporin as an initial empirical therapy for the treatment of acute bacterial meningitis with a communitarian background.
Full-text · Article · Oct 2008 · Arquivos de Neuro-Psiquiatria
[Show abstract][Hide abstract] ABSTRACT: Quinolones (nalidixic acid--NAL, norfloxacin--NOR, ciprofloxacin--CIP and gatifloxacin--GAT) were tested against Escherichia coli isolated from urine (385 patient samples) by disk diffusion (DD) and agar dilution (AD) methods. Fifty-three samples (13.8%) were classified as resistant to at least one of the quinolones tested. CIP and NOR susceptibilities were the same (91.4%) and they were similar to GAT (92.7%). Susceptibility to NAL, detected by the disk diffusion method, was used to predict susceptibility to NOR, CIP and GAT by the agar dilution method. The sensitivity and specificity of NAL were 100% and 95%, respectively. Twelve samples were analyzed for mutations in the quinolone resistance-determining region (QRDR) of the gyrA and parC genes. Sequencing of these genes failed to find any mutations in the quinolone-sensitive isolates. However, three mutations were observed in the isolates resistant to all the quinolones tested--two in gyrA and one in parC. A single mutation in gyrA was found in the strains that were resistant to nalidixic acid but fluoroquinolone-sensitive. These findings support the suggestion that NAL could be used as a marker for susceptibility to fluoroquinolones in routine microbiology laboratories. The overall resistance rate to quinolones in the present study was 13.8%, which is higher than that observed in other studies carried out in developed countries. Our findings serve as a warning that resistance to this group of antimicrobial agents is increasing.
Full-text · Article · Mar 2008 · The Brazilian journal of infectious diseases: an official publication of the Brazilian Society of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Isolation and identification of etiological agents found in body fluids can be of critical importance for the recovery of patients suffering from potentially-severe infections, which are often followed by serious sequels. Eighty-two samples of different body fluids were analyzed using two different methods: (1) the conventional culture method (agar plating) and (2) the enrichment culture technique, using the Bact/Alert blood culture bottle. The number of positive cultures increased on average from 9.7% to 23.1% with the enrichment culture technique. Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the most frequently isolated bacteria. The enrichment method could provide a more accurate means the identifying etiological agents.
Full-text · Article · Jan 2007 · Brazilian Journal of Infectious Diseases
[Show abstract][Hide abstract] ABSTRACT: Production of extended-spectrum beta-lactamases (ESBL) by enterobacteria is an important resistance mechanism against antimicrobial beta-lactamics. We tested 498 bacterial strains isolated from two tertiary-care teaching hospitals for ESBL production, using screening breakpoints for aztreonam and third generation cephalosporins, according to CLSI recommendations. Among these isolates, 155 were positive for the ESBL screening test, and 121 (78%) were confirmed by the clavulanic acid combination disk method. We found a high frequency of ESBL (24%) among Enterobacteriaceae, with a frequency of 57.4% for Klebsiella pneumoniae, 21.4% for Klebsiella oxytoca, and 7.2% for E. coli. In other members of Enterobacteriaceae, non-Klebsiella and non-E. coli, the prevalence was 21.6%. Ceftriaxone and cefotaxime showed a higher sensitivity in the screening test (99.2%) when compared to ceftazidime, aztreonam and cefpodoxime. However, cefotaxime/cefotaxime plus clavulanic acid showed a higher sensitivity in the confirmatory test (96.7%).
Preview · Article · Jan 2007 · Brazilian Journal of Infectious Diseases