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Ana C Gales

Publications and source records attributed to Ana C Gales.

At least 19 recordsLinked to original sources
PubMed2007

First report of plasmid-mediated qnrA1 in a ciprofloxacin-resistant Escherichia coli strain in Latin America.

Among 144 ciprofloxacin-resistant Escherichia coli isolated in Brazil, one (0.69%) QnrA1-producing isolate was detected. The qnrA1 gene was associated with ISCR1. The QnrA1 determinant was carried on a 41-kb conjugative plasmid, which also carried a FOX-type cephalosporinase encoding gene and a class 1 integron with the aadB and catB3 cassettes. This is the first report of a qnrA-carrying isolate in a Latin American country.

Anti-Bacterial Agents↗
PubMed2006

Rapid detection and identification of metallo-beta-lactamase-encoding genes by multiplex real-time PCR assay and melt curve analysis.

Metallo-beta-lactamase enzymes (MbetaL) are encoded by transferable genes, which appear to spread rapidly among gram-negative bacteria. The objective of this study was to develop a multiplex real-time PCR assay followed by a melt curve step for rapid detection and identification of genes encoding MbetaL-type enzymes based on the amplicon melting peak. The reference sequences of all genes encoding IMP and VIM types, SPM-1, GIM-1, and SIM-1 were downloaded from GenBank, and primers were designed to obtain amplicons showing different sizes and melting peak temperatures (Tm). The real-time PCR assay was able to detect all MbetaL-harboring clinical isolates, and the Tm-assigned genotypes were 100% coincident with previous sequencing results. This assay could be suitable for identification of MbetaL-producing gram-negative bacteria by molecular diagnostic laboratories.

Bacterial Typing Techniques↗
PubMed2006

Dissemination of IMP-1 metallo- beta -lactamase-producing Acinetobacter species in a Brazilian teaching hospital.

OBJECTIVE: To evaluate the emergence and dissemination of metallo- beta -lactamase (MBL)-producing Acinetobacter species. DESIGN: All carbapenem-resistant Acinetobacter strains (1 strain per patient) collected during the period 1993-2001 were evaluated. SETTING: A Brazilian tertiary care teaching hospital (Hospital Sao Paulo, Sao Paulo). METHODS: Seventy-three strains of carbapenem-resistant Acinetobacter species were recovered from the organism bank of the hospital. All isolates were tested for antimicrobial susceptibility by broth microdilution methods, and the production of MBL was initially assessed by phenotypic tests (MBL Etest strip and a disk approximation test). The MBL enzymes were identified by polymerase chain reaction using primers for bla(IMP), bla(VIM), and bla(SPM), followed by gene sequencing. Genetic similarity among the carbapenem-resistant strains was evaluated by automated ribotyping. RESULTS: Only colistin and ampicillin-sulbactam showed reasonable in vitro activity against carbapenem-resistant isolates (97% and 74% of isolates susceptible, respectively). More than half of the isolates (55%) had a positive MBL phenotypic test result and a positive polymerase chain reaction result for bla(IMP-1). The proportion of IMP-1-producing Acinetobacter isolates among carbapenem-resistant strains increased from 0% in the 1993-1997 period to 29% in 1998 and 100% in the 1999-2001 period. No carbapenem-resistant Acinetobacter isolates that harbored bla(VIM) or bla(SPM) were detected. Molecular typing results revealed 20 ribogroups among carbapenem-resistant isolates. During the study period of 1994-2001, we identified 2 major ribogroups, 52-1 (MBL-negative and MBL-positive strains) and 60-7 (MBL-positive strains), that had a coefficient of similarity of 0.85 or higher. CONCLUSIONS: Our results indicate that IMP-1-producing strains of Acinetobacter emerged in our institution in 1998. Since then, production of this MBL was detected not only in the major ribogroups of carbapenem-resistant Acinetobacter species but also among isolates that belonged to 17 distinct ribogroups, indicating that this important mechanism of antimicrobial resistance was disseminated among distinct clones.

Acinetobacter↗
PubMed2006

Emergence of linezolid-resistant Staphylococcus aureus during treatment of pulmonary infection in a patient with cystic fibrosis.

We report the first linezolid-resistant Staphylococcus aureus strain isolated in Brazil. The strain was isolated from a 10-year-old female patient with cystic fibrosis (CF) who received repeated and prolonged courses of low-dose linezolid. The strain belonged to the Brazilian endemic methicillin-resistant S. aureus clone, and the G2576U mutation was identified in domain V of the 23S rRNA. Detection of this mechanism of resistance in a CF patient is very worrisome, as these patients may become a reservoir for further dissemination of resistant strains. Our findings emphasise the importance of optimal dosage of linezolid to prevent the emergence of resistance.

Acetamides↗
PubMed2006

In vitro activity of tigecycline, a new glycylcycline, tested against 1,326 clinical bacterial strains isolated from Latin America.

UNLABELLED: The in vitro activity of tigecycline (former GAR-936), a new semisynthetic tetracycline, was evaluated in comparison with tetracycline and other antimicrobial agents. MATERIAL AND METHODS: A total of 1,326 contemporary clinical isolates collected from the Latin American region were collected in 2000-2002 period and tested with microdilution broth according to the CLSI guidelines. The bacterial pathogens evaluated included Staphylococcus aureus (505), Streptococcus pneumoniae (269), coagulase-negative staphylococci (CoNS; 227), Haemophilus influenzae (129), Enterococcus spp. (80), Moraxella catarrhalis (54), beta-haemolytic streptococci (28), viridans group streptococci (26), and Neisseria meningitidis (8) RESULTS: Tigecycline demonstrated excellent activity against all Gram-positive cocci, with 90% of penicillin-resistant S. pneumoniae strains being inhibited at 0.12 microg/mL, while the same isolates had an MIC90 of > 16 microg/mL for tetracycline. All Enterococcus spp. were inhibited at 0.25 microg/mL of tigecycline. Tigecycline (MIC50, 0.25 microg/mL) was eight-fold more potent than minocycline (MIC50, 2 microg/mL) against oxacillin-resistant S. aureus (ORSA); all ORSA were inhibited at < 2 microg/mL of tigecycline. Tigecycline demonstrated excellent activity (MIC50, 0.5 microg/mL) against CoNS with reduced susceptibility to teicoplanin (MIC, 16 microg/mL). Tigecycline also showed high potency against respiratory pathogens such as M. catarrhalis (MIC50, 0.12 microg/mL) and H. influenzae (MIC50, 0.5 microg/mL). No tigecycline resistant isolates were detected when the proposed susceptible breakpoints (< 4 microg/mL) was applied. CONCLUSIONS: This results indicate that tigecycline has potent in vitro activity against clinically important pathogenic bacteria, including Gram-positive isolates resistant to both tetracycline and minocycline.

Anti-Bacterial Agents↗
PubMed2006

Changing antimicrobial susceptibility patterns among Streptococcus pneumoniae and Haemophilus influenzae from Brazil: Report from the SENTRY Antimicrobial Surveillance Program (1998-2004).

Although antimicrobial resistance rates among Streptococcus pneumoniae and Haemophilus influenzae have increased significantly in most countries in the last years, most studies from Brazil report relatively low resistance rates among these pathogens. In this study, we analyzed the susceptibility patterns of S. pneumoniae and H. influenzae from Brazil during a 7-year period. A total of 829 S. pneumoniae and 718 H. influenzae consecutively collected from 1998 to 2004, mainly from respiratory tract and bloodstream infections, were susceptibility tested by broth microdilution methods against >30 drugs and the results were analyzed by year. Overall, 77.8% of S. pneumoniae strains were considered susceptible (MIC, < or =0.06 microg/ml) to penicillin. Resistance to penicillin (MIC, > or =2 microg/ml) and ceftriaxone (MIC, > or =4 microg/ml) were detected in 7.5 and 0.5% of strains, respectively. The fluoroquinolones, levofloxacin (MIC90) 1 microg/ml) and gatifloxacin (MIC90, 0.5 microg/ml), were active against 99.8% of the isolates tested. Among the other non-beta-lactam drugs tested, the rank order of susceptibility rates was chloramphenicol (98.9%) > clindamycin (96.4%) > erythromycin (90.6%) > tetracycline (69.8%) > trimethoprim/sulfamethoxazole (36.7%). Resistance to penicillin has increased markedly among S. pneumoniae isolates over 7 years (from 2.9 to 11.0%). Additionally, resistance rates against erythromycin, clindamycin, and tetracycline decreased among pneumococcal strains during the same period. S. pneumoniae recovered from pediatric patients (< or =5 years) showed increased penicillin and trimethoprim/sulfametroxazole resistance rates compared to older populations. The rate of ampicillin resistance among H. influenzae was 14.0%, which also corresponds with the beta -lactamase production rate. All H. influenzae isolates were susceptible to amoxicillin/clavulanate (MIC90, 1 microg/ml), ceftriaxone (MIC90, < or =0.008 microg/ml), cefepime (MIC90, 0.12 microg/ml), ciprofloxacin (MIC90, < or = 0.12microg/ml), levofloxacin (MIC90, < or =0.5 microg/ml), and gatifloxacin (MIC90, < or =0.03 microg/ml). Resistance to the antimicrobials tested remained very stable among H. influenzae isolates during the 7-year study period. The continued emerging antimicrobial resistances found in these pathogens (mainly S. pneumoniae) highlight the need for alternative agents for the treatment of infections caused by these species.

Anti-Bacterial Agents↗
PubMed2006

Increased resistance to first-line agents among bacterial pathogens isolated from urinary tract infections in Latin America: time for local guidelines?

Emerging resistance phenotypes and antimicrobial resistance rates among pathogens recovered from community-acquired urinary tract infections (CA-UTI) is an increasing problem in specific regions, limiting therapeutic options. As part of the SENTRY Antimicrobial Surveillance Program, a total of 611 isolates were collected in 2003 from patients with CA-UTI presenting at Latin American medical centers. Each strain was tested in a central laboratory using Clinical Laboratory Standard Institute (CLSI) broth microdilution methods with appropriate controls. Escherichia coli was the leading pathogen (66%), followed by Klebsiella spp. (7%), Proteus mirabilis (6.4%), Enterococcus spp. (5.6%), and Pseudomonas aeruginosa (4.6%). Surprisingly high resistance rates were recorded for E. coli against first-line orally administered agents for CA-UTI, such as ampicillin (53.6%), TMP/SMX (40.4%), ciprofloxacin (21.6%), and gatifloxacin (17.1%). Decreased susceptibility rates to TMP/SMX and ciprofloxacin were also documented for Klebsiella spp. (79.1 and 81.4%, respectively), and P. mirabilis (71.8 and 84.6%, respectively). For Enterococcus spp., susceptibility rates to ampicillin, chloramphenicol, ciprofloxacin, and vancomycin were 88.2, 85.3, 55.9, and 97.1%, respectively. High-level resistance to gentamicin was detected in 24% of Enterococcus spp. Bacteria isolated from patients with CA-UTI in Latin America showed limited susceptibility to orally administered antimicrobials, especially for TMP/SMX and fluoroquinolones. Our results highlight the need for developing specific CA-UTI guidelines in geographic regions where elevated resistance to new and old compounds may influence prescribing decisions.

Adult↗
PubMed2005

Antimicrobial susceptibility patterns of unusual nonfermentative gram-negative bacilli isolated from Latin America: report from the SENTRY Antimicrobial Surveillance Program (1997-2002).

The antimicrobial susceptibility of 176 unusual non-fermentative gram-negative bacilli (NF-GNB) collected from Latin America region through the SENTRY Program between 1997 and 2002 was evaluated by broth microdilution according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. Nearly 74% of the NF-BGN belonged to the following genera/species: Burkholderia spp. (83), Achromobacter spp. (25), Ralstonia pickettii (16), Alcaligenes spp. (12), and Cryseobacterium spp. (12). Generally, trimethoprim/sulfamethoxazole (MIC50, < 0.5 microg/ml) was the most potent drug followed by levofloxacin (MIC50, 0.5 microg/ml), and gatifloxacin (MIC50, 1 microg/ml). The highest susceptibility rates were observed for levofloxacin (78.3%), gatifloxacin (75.6%), and meropenem (72.6%). Ceftazidime (MIC50, 4 microg/ml; 83.1% susceptible) was the most active beta-lactam against B. cepacia. Against Achromobacter spp. isolates, meropenem (MIC50, 0.25 microg/ml; 88% susceptible) was more active than imipenem (MIC50, 2 microg/ml). Cefepime (MIC50, 2 microg/ml; 81.3% susceptible), and imipenem (MIC50, 2 microg/ml; 81.3% susceptible) were more active than ceftazidime (MIC50, >16 microg/ml; 18.8% susceptible) and meropenem (MIC50, 8 microg/ml; 50% susceptible) against Ralstonia pickettii. Since selection of the most appropriate antimicrobial agents for testing and reporting has not been established by the NCCLS for many of NF-GNB species, results from large multicenter studies may help to guide the best empiric therapy.

Anti-Bacterial Agents↗
PubMed2005

First isolation of metallo-beta-lactamase-producing multiresistant Klebsiella pneumoniae from a patient in Brazil.

A multiresistant Klebsiella pneumoniae isolate was taken from the blood of a 75-year-old patient with nosocomial pneumonia who developed septic shock and failed therapy with imipenem. The isolate presented an MIC of imipenem of 128 microg/ml, and the production of a metallo-beta-lactamase was confirmed by phenotypic and genotypic techniques. We here report, for the first time, the detection of a metalloenzyme (IMP-1)-producing K. pneumoniae clinical strain in Latin America. The gene responsible for this phenotype was found to be bla(IMP-1), carried in a class 1 integron.

Aged↗
PubMed2004

Carbapenem-resistant Pseudomonas aeruginosa outbreak in an intensive care unit of a teaching hospital.

The genetic similarity of carbapenem-resistant Pseudomonas aeruginosa strains isolated in the Hospital Universitário São Francisco, Bragança Paulista, São Paulo, Brasil, was evaluated by pulsed field gel electrophoresis (PFGE). A unique clone was detected among 5 of 7 isolates, suggesting that cross-contamination might have played a role in the spread of carbapenem-resistant P. aeruginosa strains. Interestingly, a similar PFGE pattern was encountered in a P. aeruginosa strain isolated from Hospital São Paulo that was used as a PFGE control.

Adult↗
PubMed2004

SENTRY antimicrobial surveillance program report: Latin American and Brazilian results for 1997 through 2001.

The alarming emergence and spread of antimicrobial resistance among common bacteria threatens the effectiveness of therapy for many infections. Surveillance of antimicrobial resistance is essential to identify the major problems and guide adequate control measures. Several resistance surveillance programs have been implemented in North America and Europe in the last decade; however, very few programs have assessed antimicrobial resistance in Latin American countries. The SENTRY Antimicrobial Surveillance Program was initiated in 1997 and represents the most comprehensive surveillance program in place at the present time worldwide. The SENTRY Program collects consecutive isolates from clinically documented infections in more than 80 medical centers worldwide (10 in Latin America). The isolates are collected according to the type of infection (objectives) and susceptibility tested in a central microbiology laboratory by reference broth microdilution methods according to NCCLS guidelines. The Program also incorporated molecular typing (ribotyping and PFGE) and resistance mechanism analysis of selected isolates. In this report we present a very broad analysis of the data generated by testing almost 20,000 bacterial isolates against more than 30 antimicrobial agents. The susceptibility results (MIC(50), MIC(90) and % susceptible) are presented in 11 tables according to the organism and site of infection. The data from Brazil, as well as the data from isolates collected in 2001, are analyzed separately. This report allows the evaluation of the activities numerous antimicrobial agents against clinical isolates collected in Latin American countries.

Anti-Bacterial Agents↗
PubMed2004

Ability of Latin America laboratories to detect antimicrobial resistance patterns: experience of the SENTRY Antimicrobial Surveillance Program (1997-2000).

The accuracy of antimicrobial susceptibility tests is a crucial step for the clinical management of patients with serious infections. They must be reliable and precise because they will guide antimicrobial therapy. Our main objective was to compare the results of susceptibility testing performed by the SENTRY coordinator laboratory with those reported by the participating Latin American medical centers. A total of 10,277 bacterial isolates were tested by the reference broth microdilution method at the coordinator laboratory in the United States. The tests were performed and interpreted following the National Committee for Clinical Laboratory Standards (NCCLS) recommendations. Ten antimicrobial agent-organism combinations were analyzed. The susceptibility methods utilized in each of the medical centers were also evaluated. Total agreement of the results was obtained in nearly 88% of the antimicrobial agent-organism combinations. "Very major" (false-susceptible results) and "major errors" (false-resistant results) were observed in 12% and 6% of the cases, respectively. The highest disagreements were observed for coagulase-negative Staphylococcus_oxacillin (20% - very major error) and Burkholderia cepacia_imipenem (21% - very major error). The susceptibility method with the highest agreement rate was Etest (92%) > PASCO (91%) > agar dilution (91%) > MicroScan (90%) > Vitek (87%). External quality assurance data obtained by surveillance programs such as the SENTRY Antimicrobial Surveillance Program are not only helpful for detecting the emergence of patterns of antimicrobial resistance, but also to monitor the performance of the participating microbiology laboratories.

Anti-Bacterial Agents↗
PubMed2003

Dissemination in distinct Brazilian regions of an epidemic carbapenem-resistant Pseudomonas aeruginosa producing SPM metallo-beta-lactamase.

BACKGROUND: In Brazil, carbapenem use has been limited by high carbapenem-resistance rates among Pseudomonas aeruginosa isolates. OBJECTIVE: The main objective of this study was to evaluate the presence of an epidemic P. aeruginosa strain in unrelated Brazilian hospitals. We also aimed to search for the gene blaSPM, which encodes production of SPM, a novel metallo-beta-lactamase (MBL). METHODS: A reference broth microdilution method was used for antimicrobial susceptibility testing. The isolates were typed by ribotyping and pulsed-field gel electrophoresis (PFGE). A disc-approximation test using MBL inhibitors was employed to screen isolates for MBL production. PCR was used to search for the gene blaSPM. RESULTS: A total of 43 clinical isolates of carbapenem-resistant P. aeruginosa were collected from 12 hospitals. Colistin retained greatest activity in vitro. A single ribogroup included 17 P. aeruginosa isolates (39.5%) collected from seven unrelated hospitals located in five Brazilian states. Sixteen of these isolates showed an identical PFGE pattern, and 15 produced an SPM-1-like MBL. The remaining 26 isolates were grouped into 25 diverse ribogroups; none were MBL producers. CONCLUSIONS: The emergence and dissemination of an epidemic clone has contributed to the high carbapenem resistance rates among P. aeruginosa isolates in Brazil. In addition, the production of SPM MBL has an important role in carbapenem resistance in this region. This is the first report of dissemination of an SPM-1-like-MBL-producing strain of P. aeruginosa among unrelated Brazilian hospitals.

Brazil↗