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Helio S Sader

Publications and source records attributed to Helio S Sader.

At least 91 records · Page 5Linked to original sources
PubMed2004

Antimicrobial activity of daptomycin against multidrug-resistant Gram-positive strains collected worldwide.

Daptomycin is a cyclic lipopeptide recently released for clinical use in the treatment of serious Gram-positive infections in hospitalized patients. We evaluated the in vitro activity of daptomycin tested against recently isolated multidrug-resistant Gram-positive clinical strains. A total of 386 isolates were selected from a large collection of strains from more than 70 centers located in Europe, North America, and South America. The strains were tested by reference broth microdilution methods in Mueller-Hinton broth with 50 mg/L Ca++ against daptomycin. Daptomycin was the most potent compound tested against penicillin-resistant Streptococcus pneumoniae with MIC50/90 values at < or =0.12 and 0.25 microg/mL, respectively. Daptomycin was also highly active against vancomycin-resistant enterococci and staphylococcal strains with various resistance patterns. Enterococcus faecium showed higher daptomycin MIC values (MIC90, 4 microg/mL) when compared to E. faecalis (MIC90, 1 microg/mL). In summary, resistance to vancomycin, teicoplanin, quinupristin/dalfopristin, or penicillin among the Gram-positive isolates did not adversely influence daptomycin activity. Daptomycin showed a significant potency and spectrum against Gram-positive species, including multidrug-resistant strains, and may represent a reasonable therapeutic option for infections caused by these important pathogens.

Anti-Bacterial Agents↗
PubMed2004

Results from the Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Programme: report of the 2001 data from 15 United States medical centres.

The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Programme is an international surveillance network of more than 100 medical centres where meropenem is the primary therapeutic carbapenem. Institutions have been monitored since 1997 (1999 in United States (US)) using National Committee for Clinical Laboratory Standards (NCCLS) reference susceptibility methods to monitor in vitro activity of meropenem and selected other broad-spectrum antimicrobial agents. In 2001, a total of 2874 strains were processed from the 15 US medical centres. Molecular methods were associated with MIC methods as needed for defining epidemic spread of resistant strains. The meropenem MIC(90) values were 0.03 mg/l for Citrobacter spp., Escherichia coli and Klebsiella spp.; 0.06 mg/l for Proteus mirabilis and Serratia spp. and 0.12 mg/l for Enterobacter spp. This potency was 8-16-fold greater than that of imipenem and the meropenem spectrum of activity versus the Enterobacteriaceae was the broadest of all tested antimicrobial agents. Only piperacillin/tazobactam (MIC(9), 64 mg/l) and tobramycin (MIC(90), 4 mg/l) were active against more than 90.0% of Pseudomonas aeruginosa at the NCCLS susceptible breakpoint, and the carbapenems were the most active compounds against Acinetobacter spp. However, Acinetobacter spp. isolates were resistant to all of the antimicrobial agents tested and the molecular typing results suggested that they were epidemiologically related. Only ciprofloxacin and ceftazidime had significantly reduced activity against oxacillin-susceptible staphylococci (87.9-92.6% susceptible. These 2001 US MYSTIC Programme results demonstrated no significant decline in carbapenem activity or susceptibility rates compared with the previously monitored years (1999-2000). Most apparent were the decreasing susceptibility rates for ciprofloxacin and ceftazidime against staphylococci. Continued surveillance in these institutions appears warranted as sites of high potential emerging resistance risk.

Academic Medical Centers↗
PubMed2004

Assessment of pathogen occurrences and resistance profiles among infected patients in the intensive care unit: report from the SENTRY Antimicrobial Surveillance Program (North America, 2001).

Originating from 25 selected intensive care units (ICUs) in North America, a total of 1,321 bacterial strains from blood, respiratory tract, urine and wound sites were processed at a central laboratory as part of the SENTRY Antimicrobial Surveillance Program (2001) to assess their occurrence rates and antimicrobial susceptibility profiles. The rank order of pathogens recovered was Staphylococcus aureus (24.1%), Pseudomonas aeruginosa (12.2%), Escherichia coli (10.1%), Klebsiella spp. (8.9%), Enterococcus spp. (7.2%), coagulase-negative staphylococci (7.0%) and Enterobacter spp. (7.0%). Although oxacillin resistance among S. aureus was 51.4%, no resistance was detected to vancomycin, linezolid and quinupristin/dalfopristin. The most active agents tested against P. aeruginosa were amikacin, cefepime, tobramycin, meropenem and piperacillin/tazobactam (3.1-13.0% resistance). Among agents tested against the Enterobacteriaceae, amikacin, cefepime, imipenem and meropenem showed greatest in vitro activity (0.0-3.4% resistance). Extended-spectrum beta-lactamase-producing phenotype rates were 11.2 and 16.2% in E. coli and Klebsiella spp., respectively. Linezolid was most active against enterococci (1.1% resistance; G2576U ribosomal mutation) whereas 28.4% of isolates were resistant to vancomycin. Cefepime and the carbapenems (imipenem or meropenem) for Gram-negative isolates and linezolid for Gram-positive isolates, provided the broadest spectrum of in vitro activity against contemporary ICU pathogens in North America.

Anti-Bacterial Agents↗
PubMed2004

Genotypic characterization of carbapenem-nonsusceptible Acinetobacter spp. isolated in Latin America.

The principal aim of this study was to evaluate the genomic diversity among the imipenem-nonsusceptible Acinetobacter spp. (INSA) collected from the Latin American medical centers within the SENTRY Antimicrobial Surveillance Program. The INSA isolates were collected from patients with bloodstream infections, who were hospitalized in seven Latin American countries between 1997 and 1999. For epidemiologic comparison, 20 carbapenem-susceptible Acinetobacter spp. (CSA) isolates were collected in the same period of time from the respective medical centers. A total of 23 Acinetobacter spp. isolates exhibiting imipenem MIC values of >/=8 microg/ml were typed by ribotyping, an automated molecular method. The isolates showing an identical ribogroup were also typed by pulsed-field gel electrophoresis (PFGE). The antimicrobial susceptibility to various antimicrobial agents was evaluated using a reference broth microdilution technique. Among the INSA isolates, 13 distinct ribogroups were observed, whereas 16 ribogroups were detected among the CSA. Nearly 57% of the INSA belonged to only four ribogroups. Identical ribogroups and PFGE patterns were observed among INSA and CSA isolates collected from medical centers located in different countries (Brazil and Argentina). Our results showed: (1) a higher genomic variability among the CSA; (2) presence of epidemic clones among INSA isolates encountered in Latin American medical centers; and (3) spread of INSA and CSA epidemic clones between Latin American countries.

Acinetobacter↗
PubMed2004

In vitro activities of the novel cephalosporin LB 11058 against multidrug-resistant Staphylococci and Streptococci.

LB 11058 is a novel parenteral cephalosporin with a C-3 pyrimidinyl-substituted vinyl sulfide group and a C-7 2-amino-5-chloro-1,3-thiazole group. This study evaluated the in vitro activity and spectrum of LB 11058 against 1,245 recent clinical isolates, including a subset of gram-positive strains with specific resistant phenotypes. LB 11058 was very active against Streptococcus pneumoniae. The novel cephalosporin was 8- to 16-fold more potent than ceftriaxone, cefepime, or amoxicillin-clavulanate against both penicillin-intermediate and -resistant S. pneumoniae. LB 11058 was also very active against both beta-hemolytic streptococci (MIC at which 90% of isolates were inhibited [MIC(90)], </=0.008 micro g/ml) and viridans group streptococci (MIC(90), 0.03 to 0.5 micro g/ml), including penicillin-resistant strains. Among oxacillin-susceptible Staphylococcus aureus, LB 11058 MIC results varied from 0.06 to 0.25 micro g/ml (MIC(50), 0.12 micro g/ml), while among oxacillin-resistant strains LB 11058 MICs varied from 0.25 to 1 micro g/ml (MIC(50), 1 micro g/ml). Coagulase-negative staphylococci showed an LB 11058 susceptibility pattern similar to that of S. aureus, with all isolates being inhibited at </=1 micro g/ml. LB 11058 also showed reasonable in vitro activity against Enterococcus faecalis, including vancomycin-resistant strains (MIC(50), 1 micro g/ml), and Bacillus spp. (MIC(50), 0.25 micro g/ml); however, it was less active against Enterococcus faecium (MIC(50), >64 micro g/ml) and Corynebacterium spp. (MIC(50), 32 micro g/ml). Against gram-negative pathogens, LB 11058 showed activity against Haemophilus influenzae (MIC(90), 0.25 to 0.5 micro g/ml) and Moraxella catarrhalis (MIC(90), 0.25 micro g/ml), with MICs not influenced by beta-lactamase production. In conclusion, LB 11058 demonstrated a broad antibacterial spectrum and was highly active against gram-positive bacteria, particularly against multidrug-resistant staphylococci and streptococci.

Anti-Bacterial Agents↗
PubMed2004

Integron carrying a novel metallo-beta-lactamase gene, blaIMP-16, and a fused form of aminoglycoside-resistant gene aac(6')-30/aac(6')-Ib': report from the SENTRY Antimicrobial Surveillance Program.

Since January 2002 Pseudomonas sp. strains resistant to carbapenems and ceftazidime have been routinely screened as part of the SENTRY Antimicrobial Surveillance Program for metallo-beta-lactamase production, and their resistance determinants have been analyzed. Pseudomonas aeruginosa index strain 101-4704, which harbors a novel bla(IMP) variant, bla(IMP-16), was isolated in April 2002 from a 60-year-old man in Brasilia, Brazil. bla(IMP-16) was found on the chromosome of the P. aeruginosa index strain, and the deduced amino acid sequence (IMP-16) showed the greatest identities to IMP-11 (90.3%) and IMP-8 (89.5%). Sequence analysis revealed that bla(IMP-16) was associated with a class 1 integron, which also encoded aminoglycoside-modifying enzymes. Downstream of bla(IMP-16) resided an open reading frame, which consisted of a new aminoglycoside-modifying gene, namely, aac(6')-30, which was fused with aac(6')-Ib'. The amino acid sequence of the aac(6')-30 putative protein showed the most identity (52.7%) to the sequence of AAC(6')-29b described previously. The fourth gene cassette constituted aadA1. The steady-state kinetics of IMP-16 demonstrated that the enzyme preferred cephalosporins and carbapenems to penicillins. The main functional difference observed among the kinetic values for IMP-16 compared to those for other IMPs was a lack of cefoxitin hydrolysis and a lower kcat/Km value for imipenem (0.36 microM(-1) . s(-1)). This report further emphasizes the spread of metallo-beta-lactamase genes and their close association with various aminoglycoside resistance genes.

Amino Acid Sequence↗
PubMed2004

Omiganan pentahydrochloride (MBI 226), a topical 12-amino-acid cationic peptide: spectrum of antimicrobial activity and measurements of bactericidal activity.

The activity of omiganan pentahydrochloride (formerly MBI 226; a synthetic cationic peptide) was assessed against 1,437 recent clinical bacterial isolates and 214 recent clinical yeast isolates. The omiganan was highly active, and minimal bactericidal concentrations or minimal fungicidal concentrations were either equal to or two- to fourfold higher than MICs. Kill curve experiments showed a clear pattern of bactericidal activity.

Anti-Bacterial Agents↗
PubMed2004

Antimicrobial susceptibility and epidemiology of a worldwide collection of Chryseobacterium spp: report from the SENTRY Antimicrobial Surveillance Program (1997-2001).

Limited data are available on Chryseobacterium spp. leading to an evaluation of the patient demographics and susceptibility patterns for Chryseobacterium spp. collected in the first 5 years of the SENTRY Antimicrobial Surveillance Program (1997 to 2001). Fifty isolates (24 Chryseobacterium meningosepticum, 20 Chryseobacterium indologenes, two Chryseobacterium gleum, and 4 Chryseobacterium spp. isolates) were collected. The highest Chryseobacterium prevalence was detected among the elderly. The most active antimicrobials were the newer quinolones (garenoxacin, gatifloxacin, and levofloxacin, each with a MIC at which 90 percent of the isolates are inhibited [MIC(90)] of 1 micro g/ml and 98.0% susceptibility) followed by rifampin (MIC(90), 2 microg/ml and 85.7% susceptibility). Trimethoprim-sulfamethoxazole, ciprofloxacin, and piperacillin-tazobactam also showed reasonable activity; vancomycin showed poor potency.

Anti-Infective Agents↗
PubMed2003

Endocarditis due to glycopeptide-intermediate Staphylococcus aureus: case report and strain characterization.

We report a case of infective endocarditis due to vancomycin-intermediate Staphylococcus aureus (VISA) that did not respond to high doses of vancomycin. Initial vancomycin MIC of the last isolate recovered from blood was 8 micro g/mL, but could be induced up to 32 micro g/mL by consecutive growing with vancomycin. Clinical response was only accomplished when linezolid was included in therapy.

Drug Resistance, Multiple, Bacterial↗
PubMed2003

Global patterns of susceptibility for 21 commonly utilized antimicrobial agents tested against 48,440 Enterobacteriaceae in the SENTRY Antimicrobial Surveillance Program (1997-2001).

A total of 48,440 Enterobacteriaceae isolates collected consecutively from patients hospitalized in participant SENTRY Antimicrobial Surveillance Program sites in four international regions (Asia-Pacific, Europe, Latin America, and North America) were tested by reference broth microdilution method against the most commonly used antimicrobial agents. The most active compounds could be divided in 3 groups based on their spectrum of activity. The first group included meropenem and imipenem, with 99.9% susceptibilty (S) rates for the Enterobacteriaceae. The second group includes amikacin (97.3% S) and cefepime (97.2% S); and a third active group had a rank order of susceptibility of: gatifloxacin = levofloxacin (91.7% S) > ceftazidime (91.4% S) > ceftriaxone (91.2% S) > aztreonam (91.1% S) > gentamicin (90.6% S) > piperacillin/tazobactam = ciprofloxacin (90.5% susceptibility). These latter antimicrobial agents presented susceptibility rates of approximately 90% (89.8%-91.7%). Continued resistance surveillance by various programs remain necessary to monitor the in vitro effectiveness of antimicrobial agents currently used in clinical practice.

Anti-Bacterial Agents↗
PubMed2003

Contemporary re-evaluation of the activity and spectrum of grepafloxacin tested against isolates in the United States.

Grepafloxacin potency and spectrum of activity were re-evaluated against contemporary pathogens collected from clinical infections in 2001-2002. A total of 995 isolates were tested for grepafloxacin by the reference agar dilution method and these results were compared to those of 25 other antimicrobial agents. Grepafloxacin activity remained comparable to that of ciprofloxacin, levofloxacin and gatifloxacin against Escherichia coli, Klebsiella pneumoniae and Enterobacter cloacae (MIC(90), 0.03-2 microg/ml; 0.0-7.7% resistance rates). For Pseudomonas aeruginosa, grepafloxacin was active against ciprofloxacin-susceptible (MIC(90), 2 microg/ml), but not against ciprofloxacin-resistant (MIC(90), >8 microg/ml) isolates. Against methicillin-susceptible Staphylococcus aureus, grepafloxacin susceptibility rate was 91.4%, equal to that of levofloxacin. None of the fluoroquinolones showed reasonable activity against methicillin-resistant staphylococci. Gatifloxacin and grepafloxacin had the same MIC(90) against beta-hemolytic streptococci (0.25 microg/ml) and penicillin-susceptible Streptococcus pneumoniae (0.25 microg/ml). Grepafloxacin and other fluoroquinolone activities were not influenced by penicillin resistance in S. pneumoniae. Grepafloxacin was very active against Haemophilus influenzae (MIC(90), 0.03 microg/ml), Moraxella catarrhalis (MIC(90), 0.03 microg/ml) and Legionella spp. (MIC(90), 0.5 microg/ml). These results on recently isolated organisms indicate that grepafloxacin has a sustained potency and spectrum against most clinically important and indicated pathogens.

Anti-Bacterial Agents↗
PubMed2003

Comparative activity and spectrum of broad-spectrum beta-lactams (cefepime, ceftazidime, ceftriaxone, piperacillin/tazobactam) tested against 12,295 staphylococci and streptococci: report from the SENTRY antimicrobial surveillance program (North America: 2001-2002).

A contemporary collection of 12,295 North American isolates (2001-2002) consisting of Staphylococcus aureus (50%), coagulase-negative staphylococci (12%), Streptococcus pneumoniae (24%), beta-hemolytic streptococci (12%), and viridans-group streptococci (2%) were tested against broad-spectrum beta-lactams (cefepime, ceftazidime, ceftriaxone, imipenem, piperacillin/tazobactam) and comparator agents using a reference broth microdilution method to determine their continued effectiveness for empiric antimicrobial therapy. All isolates were very susceptible to vancomycin, linezolid and quinupristin/dalfopristin (>98%). Oxacillin-susceptible staphylococci were also highly susceptible to the tested beta-lactams (>98%) with the exception of ceftazidime (93%). beta-hemolytic streptococci were exquisitely susceptible (>99%) to penicillin and all other agents except for clindamycin (94%) and erythromycin (81%). Viridans group streptococci were routinely less susceptible than were other streptococci. S. pneumoniae remained susceptible to most agents (>91%) with the exceptions of erythromycin (74%) and penicillin (69%). Among beta-lactams tested against S. pneumoniae, ceftriaxone and cefepime continued to be very active against penicillin-susceptible (>99%) and intermediate (>98%) strains, but less active (80% and 82%, respectively) against penicillin-resistant isolates. These findings confirm that the newer cephalosporins (cefepime and ceftriaxone) among broad-spectrum beta-lactam agents have a spectrum of activity that remains comprehensive for the commonly isolated Gram-positive pathogens.

Drug Resistance, Bacterial↗
PubMed2003

Contemporary in vitro synergy rates for aztreonam combined with newer fluoroquinolones and beta-lactams tested against gram-negative bacilli.

Aztreonam has been commonly used in various combinations to enhance antimicrobial spectrum of co-drugs and produce potential synergistic activity. Although well studied in vitro over 10 years ago, aztreonam combination testing has been poorly documented with newer or commonly used agents against contemporary isolates. All MIC tests (alone or in combination) used in this experiment were reference broth microdilution methods in checkerboard tray designs. Aztreonam was combined with ciprofloxacin, gatifloxacin, levofloxacin, cefepime, ceftazidime and imipenem at clinically relevant concentrations. Interaction categories were defined by established criteria. Forty strains each of Pseudomonas aeruginosa and Enterobacteriaceae (12 species; aztreonam MIC, 1-16 microg/ml) were tested for each antimicrobial combination (480 total determinations). No antagonism or indeterminate interactions were identified. The overall rates of synergy or partial synergy for aztreonam with fluoroquinolone combinations was 63.4% versus P. aeruginosa, greatest for aztreonam with gatifloxacin (67.5%). Interaction categories varied greatly among aztreonam with beta-lactam combinations. Aztreonam with ceftazidime or cefepime versus P. aeruginosa had 75.0 - 85.0% partial or complete synergy rates, but aztreonam with imipenem showed dominant indifference (65.0%). In contrast, aztreonam with imipenem was more likely to exhibit synergy (32.5%) when tested against Enterobacteriaceae. Aztreonam, often used as an aminoglycoside substitute in antimicrobial combinations, continues to demonstrate enhanced, but variable drug activity interactions for contemporary antimicrobial combinations when tested against recent (2002) clinical isolates.

Aztreonam↗
PubMed2003

Contemporary evaluation of the in vitro activity and spectrum of cefdinir compared with other orally administered antimicrobials tested against common respiratory tract pathogens (2000-2002).

Cefdinir is an oral cephalosporin approved by the Food and Drug Administration in 1997 for the treatment of acute exacerbation of chronic bronchitis, pharyngitis-tonsillitis, community-acquired pneumonia, acute maxillary sinusitis, and uncomplicated skin and skin structure infections in adults and adolescents, and acute otitis media, pharyngitis-tonsillitis, and uncomplicated skin and skin structure infections in children. Although cefdinir showed similar activity to other cephalosporins in the early studies, very limited data has been generated over the last decade. In this report, we summarize the contemporary in vitro activity and spectrum of cefdinir in comparison to numerous other orally administrated antimicrobials available for treatment of community-acquired respiratory infections. A total of 8,326 non-duplicate recent clinical isolates, including Haemophilus influenzae (3,438), Moraxella catarrhalis (1,688), and Streptococcus pneumoniae (3,200), were collected from 35 medical centers in North America during 2000 through 2002, and susceptibility tested by reference broth microdilution methods. Pneumococcal susceptibility patterns for beta-lactams and macrolides were also analyzed according to the year of isolation and the age group of the patients. Cefdinir had the greatest activity against H. influenzae among the cephalosporins tested with susceptibility rates of 97.1 to 99.0%. All of the agents tested had complete or near complete activity against M. catarrhalis. Against S. pneumoniae, cefdinir and other cephalosporins showed similar susceptibility patterns, but improved rates were observed in 2002 (78.5-79.4%) when compared to the previous monitored period (71.8-74.5%). This increase in susceptibility was mainly because of a declining the occurrence of high-level penicillin resistance (MIC >/=2 microg/ml) across all age groups. Macrolide resistance also decreased among S. pneumoniae in 2002 when compared to 2000 through 2001; however, resistance to levofloxacin continued to increase from 0.9% in 2000 to 1.4% in 2002. These results indicate a significant change in emerging beta-lactam resistance patterns (including cefdinir) with a decrease possibly influenced by greater pneumococcal vaccine use in children and the elderly. These rates of increased susceptibility could sustain and enhance the clinical activity of orally administered beta-lactams such as cefdinir.

Administration, Oral↗
PubMed2003

Contemporary in vitro spectrum of activity summary for antimicrobial agents tested against 18569 strains non-fermentative Gram-negative bacilli isolated in the SENTRY Antimicrobial Surveillance Program (1997-2001).

The frequency of occurrence and antimicrobial susceptibility patterns of 18569 non-fermentative Gram-negative bacilli consecutively collected as part of the SENTRY Antimicrobial Surveillance Program were summarized. The isolates were tested by the broth microdilution method in three coordinator laboratories using common reagents and reference methodologies. The most frequently isolated pathogen was Pseudomonas aeruginosa (11968 isolates; 64.5%) followed by Acinetobacter spp. (3468 isolates; 18.7%) and Stenotrophomonas maltophilia (1488 isolates; 8.0%). The lowest resistance rates for P. aeruginosa documented were for amikacin (8%), meropenem (10%) and cefepime (10%), and all fluoroquinolones tested showed similar resistance rates (22-24%). The most active compounds against Acinetobacter spp. were the carbapenems, imipenem (11% resistance) and meropenem (12% resistance) followed by cefepime (31% resistance) and gatifloxacin (32% resistance). Very few compounds showed reasonable in vitro activity against S. maltophilia, with the most active antimicrobial agents being trimethoprim/sulphamethoxazole, gatifloxacin and levofloxacin (5-6% resistance). Resistance surveillance among these organisms remains necessary to guide empirical antimicrobial therapy, especially for these less frequently isolated and difficult to test pathogens.

Bacterial Infections↗
PubMed2002

Skin and soft tissue infections in Latin American medical centers: four-year assessment of the pathogen frequency and antimicrobial susceptibility patterns.

We report the results of pathogen frequency and antimicrobial susceptibility of isolates collected from skin and soft tissue infections (SSTIs) in Latin American medical centers during the first 4 years (1997-2000) of the SENTRY Antimicrobial Surveillance Program. Ten laboratories participated each year distributed among nine cities in six countries. A total of 1,789 bacterial isolates were susceptibility tested by reference broth microdilution at the coordinating central laboratory. Results from isolates collected during the year 2000 were compared with those from isolates collected during the prior three years. Selected carbapenem-resistant Pseudomonas aeruginosa were genotyped by automated ribotyping to evaluate the occurrence of clonal, epidemic dissemination. The five most frequently isolated species were (n/%): Staphylococcus aureus (584/32.8%), Escherichia coli (233/13.1%), P. aeruginosa (211/11.9%), Enterococcus spp. (137/7.7%), and Klebsiella spp. (127/5.8%). The most problematic antimicrobial resistances were related to the high prevalence of multi-drug resistant (MDR) Gram-negative bacilli. Carbapenem resistance among non-fermentative Gram-negative bacilli was much higher than that reported in other regions evaluated in the SENTRY Program. Only 74.9% of P. aeruginosa and 84.9% of Acinetobacter spp. were considered susceptible to imipenem. The antimicrobial susceptibility rates of P. aeruginosa decreased during the study period for most antimicrobial agents evaluated. More than 40% of K. pneumoniae and nearly 10% of E. coli showed an extended spectrum beta-lactamase phenotype. Only 73.4% of E. coli and 76.0% of Enterobacter spp. were susceptible to ciprofloxacin. The molecular typing of carbapenem-resistant P. aeruginosa demonstrated clonal dissemination in two institutions. These reported results indicate that rates of resistance among isolates causing SSTI continue to raise in Latin America, with specific concerns for the high prevalence of MDR Gram-negative bacilli. National and international surveillance programs as a guide to focusing intervention strategies should assist in the control of escalating antimicrobial resistance in this geographic area.

Anti-Bacterial Agents↗
PubMed2002

Four-year evaluation of frequency of occurrence and antimicrobial susceptibility patterns of bacteria from bloodstream infections in Latin American medical centers.

As part of the Latin American arm of the SENTRY Antimicrobial Surveillance Program, 7,207 bacterial isolates collected consecutively from bloodstream infections (BSI) during the period of January 1997 through December 2000 were analyzed. Ten Latin American laboratories located in six countries participated in the study during each year. Antimicrobial susceptibility testing was performed using the reference NCCLS broth microdilution method. The most frequently isolated species were (n/%): Staphylococcus aureus (1,532/21.3%), Escherichia coli (1,239/17.2%), coagulase-negative Staphylococcus (1,002/13.9%), Klebsiella pneumoniae (664/9.2%), and Pseudomonas aeruginosa (470/6.5%). The prevalence of S. aureus as a cause of BSI increased from 20.5% in 1997 to 23.3% in 2000 (p = 0.011), but oxacillin-resistance rates remained relatively stable during this period (around 30%). Enterococci (216 isolates) showed low rates of resistance to both vancomycin (2.4%) and ampicillin (7.9%) and 72.7% of 289 Streptococcus pneumoniae isolates evaluated were susceptible to penicillin (MIC </=0.06 microg/mL). Resistance rates among Gram-negative bacilli were much higher than those reported in other regions evaluated in the SENTRY Program. The main antimicrobial resistance problems among these pathogens were the high prevalences of ESBL-producing E. coli (6.7%) and K. pneumoniae (47.3%), and carbapenem-resistance among P. aeruginosa (around 12%) and Acinetobacter spp. (around 10%). P. aeruginosa resistance rates to meropenem, piperacillin/tazobactam, amikacin, and ciprofloxacin showed a significant increase during the 4-year period evaluated. Resistance rates varied according to the country for several pathogen-antimicrobial combinations. In summary, resistance to most antimicrobial agents for a number of species implicated in bacteremia, especially among Gram-negative rods, has reached worrisome levels and continues to increase.

Anti-Bacterial Agents↗