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1.
Rev Argent Microbiol ; 39(3): 156-60, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17987852

RESUMEN

The aim of this study was to analyze the susceptibility trends to seven antibiotics of Bacteroides fragilis group isolates based on three survey studies performed by the Committee of Anaerobic Bacteria between 1989 and 2002. Fifty three, 82 and 65 B. fragilis group isolates were collected during each period. The antimicrobial agents included were: ampicillin, ampicillin-sulbactam (2:1), cefoxitin, piperacillin, imipenem, clindamycin, and metronidazole. Minimal inhibitory concentrations (MICs) were determined according to the reference agar dilution method described by the Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS). The most active antibiotics for B. fragilis and non-B. fragilis species throughout the three periods were: imipenem with 99.1 and 100% of activity, respectively, and metronidazole with 100% of activity. The susceptibility to ampicillin-sulbactam showed a decrease, from 100% to 90.3% and to 82.4 % in the last period, for both B. fragilis and non-B. fragilis species, respectively. The overall susceptibility rates for cefoxitin, piperacillin, and clindamycin were significantly different between B. fragilis and non-B. fragilis species (84.2% vs. 56.5%; 85.9% vs. 66.7% and 88.8% vs. 64.7%, respectively, p < 0.05). Cefoxitin was the antibiotic that showed more variations as regards periods and species. The susceptibility rates for clindamycin were low, about 60%, for non-B. fragilis species during the last two periods. The variations observed in the susceptibility patterns of the B. fragilis group isolates emphasize the need to continue monitoring the emergence of resistance in order to guide the election of the most appropriate antibiotic therapy scheme for anaerobic infections.


Asunto(s)
Infecciones por Bacteroides/microbiología , Bacteroides fragilis/efectos de los fármacos , Farmacorresistencia Bacteriana Múltiple , Ampicilina/farmacología , Resistencia a la Ampicilina , Argentina/epidemiología , Bacteroides/clasificación , Bacteroides/efectos de los fármacos , Bacteroides/aislamiento & purificación , Infecciones por Bacteroides/epidemiología , Bacteroides fragilis/aislamiento & purificación , Cefoxitina/farmacología , Clindamicina/farmacología , Humanos , Imipenem/farmacología , Metronidazol/farmacología , Pruebas de Sensibilidad Microbiana , Piperacilina/farmacología , Estudios Retrospectivos , Especificidad de la Especie , Sulbactam/farmacología , Población Urbana
2.
Rev Argent Microbiol ; 36(3): 130-5, 2004.
Artículo en Español | MEDLINE | ID: mdl-15559195

RESUMEN

The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroides fragilis group (65), Fusobacterium spp. (26), Prevotella spp. (21), Porphyromonas spp. (10), Clostridium difficile (10), other clostridia (12), and gram-positive cocci (22). The MICs were determined by the agar dilution method according to NCCLS document M11-A5. Metronidazole and piperacillin-tazobactam were the most active antimicrobial agents tested and exhibited MIC90 values of < or = 2 microg/ml and < or = 4 microg/ml against gram-negative organisms, and < or = 2 microg/ml, and < or = 8 microg/ml against gram-positive organisms, respectively. Among beta-lactams the activity against gram-negative rods was in the following order: imipenem > piperacillin > cefoxitin > ceftriaxone > ampicillin. Among the gram-positive bacteria the decreased activity was: piperacillin > imipenem > cefoxitin > ceftriaxone > ampicillin. The majority of the species studied showed different degrees of resistance to clindamycin and azitromycin. Nevertheless, 90% of Fusobacterium nucleatum and Porphyromonas spp. isolates were inhibited by 0.125 mg/ml of clindamycin and azitromycin, respectively.


Asunto(s)
Antibacterianos/farmacología , Bacterias Anaerobias/efectos de los fármacos , Farmacorresistencia Bacteriana , Antibacterianos/administración & dosificación , Antibacterianos/clasificación , Argentina , Bacterias Anaerobias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Infección Hospitalaria/microbiología , Relación Dosis-Respuesta a Droga , Farmacorresistencia Bacteriana Múltiple , Bacterias Anaerobias Gramnegativas/efectos de los fármacos , Bacterias Anaerobias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Humanos , Técnicas In Vitro , Pruebas de Sensibilidad Microbiana , Especificidad de la Especie
3.
Rev. argent. microbiol ; Rev. argent. microbiol;36(3): 130-135, jul.-sep. 2004. tab
Artículo en Español | LILACS | ID: lil-634470

RESUMEN

Se evaluó la actividad de ampicilina, ampicilina-sulbactama, cefoxitina, ceftriaxona, imipenem, piperacilina, piperacilina-tazobactama, clindamicina, metronidazol y azitromicina frente a 166 cepas de bacterias anaerobias aisladas en 8 hospitales de Buenos Aires. Se estudiaron: Bacteroides grupo fragilis (65), Fusobacterium spp. (26), Prevotella spp. (21), Porphyromonas spp. (10), Clostridium difficile (10), otros clostridios (12) y cocos gram-positivos (22). Las CIMs se determinaron usando el método patrón de dilución en agar recomendado por el NCCLS, documento M11-A5. Los antibióticos más activos fueron metronidazol y piperacilina-tazobactama que exhibieron valores de CIM90£ 2 µg/ml y £ 4 µg/ml frente a los microorganismos gram-negativos y £ 2 µg/ml y £ 8 µg/ml frente a los microorganismos gram-positivos, respectivamente. Entre los b-lactámicos el orden de actividad frente a bacilos gram-negativos fue: imipenem > piperacilina > cefoxitina > ceftriaxona > ampicilina. En gram-positivos la actividad decreciente fue: piperacilina> imipenem > cefoxitina > ceftriaxona > ampicilina. La mayoría de las especies estudiadas mostraron distintos niveles de resistencia con clindamicina y azitromicina. Sin embargo, el 90% de las cepas de Fusobacterium nucleatum y Por-phyromonas spp. fue inhibido por una concentración de 0,125 µg/ml de clindamicina y azitromicina, respectivamente.


The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroidesfragilis group (65), Fusobacterium spp. (26), Prevotella spp. (21), Porphyromonas spp. (10), Clostridium difficile (10), other clostridia (12), and gram-positive cocci (22). The MICs were determined by the agar dilution method according to NCCLS document M11-A5. Metronidazole and piperacillin-tazobactam were the most active antimicrobial agents tested and exhibited MIC90values of £ 2 µg/ml and £ 4 µg/ml against gram-negative organisms, and £ 2 µg/ml, and £ 8 µg/ml against gram-positive organisms, respectively. Among b-lactams the activity against gram-negative rods was in the following order: imipenem> piperacillin > cefoxitin > ceftriaxone > ampicillin. Among the gram-positive bacteria the decreased activity was: piperacillin> imipenem> cefoxitin > ceftriaxone > ampicillin. The majority of the species studied showed different degrees of resistance to clindamycin and azitromycin. Nevertheless, 90% of Fusobacterium nucleatum and Porphyromonas spp. isolates were inhibited by 0.125 mg/ml of clindamycin and azitromycin, respectively.


Asunto(s)
Humanos , Antibacterianos/farmacología , Bacterias Anaerobias/efectos de los fármacos , Farmacorresistencia Bacteriana , Técnicas In Vitro , Argentina , Antibacterianos/administración & dosificación , Antibacterianos/clasificación , Bacterias Anaerobias/aislamiento & purificación , Infecciones Bacterianas/microbiología , Infección Hospitalaria/microbiología , Relación Dosis-Respuesta a Droga , Farmacorresistencia Bacteriana Múltiple , Bacterias Anaerobias Gramnegativas/efectos de los fármacos , Bacterias Anaerobias Gramnegativas/aislamiento & purificación , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/aislamiento & purificación , Pruebas de Sensibilidad Microbiana , Especificidad de la Especie
4.
Rev. argent. microbiol ; Rev. argent. microbiol;36(3): 130-5, jul.-sep. 2004.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1171748

RESUMEN

The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroides fragilis group (65), Fusobacterium spp. (26), Prevotella spp. (21), Porphyromonas spp. (10), Clostridium difficile (10), other clostridia (12), and gram-positive cocci (22). The MICs were determined by the agar dilution method according to NCCLS document M11-A5. Metronidazole and piperacillin-tazobactam were the most active antimicrobial agents tested and exhibited MIC90 values of piperacillin > cefoxitin > ceftriaxone > ampicillin. Among the gram-positive bacteria the decreased activity was: piperacillin > imipenem > cefoxitin > ceftriaxone > ampicillin. The majority of the species studied showed different degrees of resistance to clindamycin and azitromycin. Nevertheless, 90


of Fusobacterium nucleatum and Porphyromonas spp. isolates were inhibited by 0.125 mg/ml of clindamycin and azitromycin, respectively.

5.
Rev. argent. microbiol ; Rev. argent. microbiol;36(3): 130-5, 2004 Jul-Sep.
Artículo en Español | BINACIS | ID: bin-38578

RESUMEN

The antimicrobial activity of ampicillin, ampicillin-sulbactam, cefoxitin, ceftriaxone, imipenem, piperacillin, piperacillin-tazobactam, clindamycin, metronidazole, and azitromycin was assesed against 166 strains of anaerobic bacteria recovered from eight hospitals in Buenos Aires. The strains studied were Bacteroides fragilis group (65), Fusobacterium spp. (26), Prevotella spp. (21), Porphyromonas spp. (10), Clostridium difficile (10), other clostridia (12), and gram-positive cocci (22). The MICs were determined by the agar dilution method according to NCCLS document M11-A5. Metronidazole and piperacillin-tazobactam were the most active antimicrobial agents tested and exhibited MIC90 values of < or = 2 microg/ml and < or = 4 microg/ml against gram-negative organisms, and < or = 2 microg/ml, and < or = 8 microg/ml against gram-positive organisms, respectively. Among beta-lactams the activity against gram-negative rods was in the following order: imipenem > piperacillin > cefoxitin > ceftriaxone > ampicillin. Among the gram-positive bacteria the decreased activity was: piperacillin > imipenem > cefoxitin > ceftriaxone > ampicillin. The majority of the species studied showed different degrees of resistance to clindamycin and azitromycin. Nevertheless, 90


of Fusobacterium nucleatum and Porphyromonas spp. isolates were inhibited by 0.125 mg/ml of clindamycin and azitromycin, respectively.

6.
Rev Argent Microbiol ; 33(3): 133-40, 2001.
Artículo en Español | MEDLINE | ID: mdl-11594003

RESUMEN

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65%), Porphyromonas gingivalis (23%), Actinobacillus actinomycetemcomitans (23%), Fusobacterium nucleatum (10%) and Peptostreptococcus sp. (31%). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71% and 78.90%, motile rods 46.12% and 16.70%, total spirochetes 26.48% and 2.80%, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.


Asunto(s)
Periodontitis/microbiología , Infecciones por Actinobacillus/epidemiología , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Adulto , Aggregatibacter actinomycetemcomitans/aislamiento & purificación , Argentina/epidemiología , Infecciones por Bacteroidaceae/epidemiología , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/patología , Placa Dental/microbiología , Infecciones por Fusobacterium/epidemiología , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/patología , Fusobacterium nucleatum/aislamiento & purificación , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Humanos , Persona de Mediana Edad , Peptostreptococcus/aislamiento & purificación , Índice Periodontal , Periodontitis/epidemiología , Periodontitis/patología , Porphyromonas gingivalis/aislamiento & purificación , Prevotella intermedia/aislamiento & purificación , Índice de Severidad de la Enfermedad
7.
Rev. argent. microbiol ; Rev. argent. microbiol;33(3): 133-140, jul.-sept. 2001.
Artículo en Español | LILACS | ID: lil-332489

RESUMEN

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65), Porphyromonas gingivalis (23), Actinobacillus actinomycetemcomitans (23), Fusobacterium nucleatum (10) and Peptostreptococcus sp. (31). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71 and 78.90, motile rods 46.12 and 16.70, total spirochetes 26.48 and 2.80, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.


Asunto(s)
Humanos , Adulto , Persona de Mediana Edad , Periodontitis , Aggregatibacter actinomycetemcomitans , Argentina , Fusobacterium nucleatum , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Infecciones por Actinobacillus/epidemiología , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Infecciones por Bacteroidaceae/epidemiología , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/patología , Infecciones por Fusobacterium/epidemiología , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/patología , Peptostreptococcus , Índice Periodontal , Periodontitis , Placa Dental/microbiología , Porphyromonas gingivalis , Prevotella intermedia , Índice de Severidad de la Enfermedad
8.
Rev. argent. microbiol ; Rev. argent. microbiol;33(3): 133-140, jul.-sept. 2001.
Artículo en Español | BINACIS | ID: bin-6764

RESUMEN

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65), Porphyromonas gingivalis (23), Actinobacillus actinomycetemcomitans (23), Fusobacterium nucleatum (10) and Peptostreptococcus sp. (31). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71 and 78.90, motile rods 46.12 and 16.70, total spirochetes 26.48 and 2.80, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.(AU)


Asunto(s)
Humanos , Adulto , Persona de Mediana Edad , Periodontitis/microbiología , Infecciones por Actinobacillus/epidemiología , Infecciones por Actinobacillus/microbiología , Infecciones por Actinobacillus/patología , Aggregatibacter actinomycetemcomitans/aislamiento & purificación , Argentina/epidemiología , Infecciones por Bacteroidaceae/epidemiología , Infecciones por Bacteroidaceae/microbiología , Infecciones por Bacteroidaceae/patología , Placa Dental/microbiología , Infecciones por Fusobacterium/epidemiología , Infecciones por Fusobacterium/microbiología , Infecciones por Fusobacterium/patología , Fusobacterium nucleatum/aislamiento & purificación , Infecciones por Bacterias Grampositivas/epidemiología , Infecciones por Bacterias Grampositivas/microbiología , Infecciones por Bacterias Grampositivas/patología , Peptostreptococcus/aislamiento & purificación , Índice Periodontal , Periodontitis/epidemiología , Periodontitis/patología , Porphyromonas gingivalis/aislamiento & purificación , Prevotella intermedia/aislamiento & purificación , Índice de Severidad de la Enfermedad
9.
Rev Argent Microbiol ; 33(2): 101-7, 2001.
Artículo en Español | MEDLINE | ID: mdl-11494752

RESUMEN

Clostridium difficile has been recognized as the most important enteric pathogen of nosocomial antibiotic-associated diarrhea (CDAD) in adults from industrialized countries. The importance of C. difficile as a cause of diarrhea in ambulatory patients appears underestimated or under-recognized. Since the 1980's, outbreaks of CDAD have been increasingly reported, but there are few data available in Argentina. We developed a retrospective study to provide some information about CDAD in our country. From July 1998 to November 1999, a total of 245 fecal specimens from hospitalized and some ambulatory patients were tested in order to confirm the diagnosis of CDAD. C. difficile cytotoxin (toxin B) was identified by detecting its cytopathic effect on monolayers of McCoy culture cells. For culture and isolation of C. difficile, stool samples were prepared by ethanol shock prior to plating onto a selective medium which contained blood, cefoxitin and fructose. Of the 245 samples, 14 (5.8%) were identified as positive by the cell cytotoxicity assay. Using the criteria of isolation of cytotoxigenic C. difficile positivity increased to 6.5% (16 samples). Thirteen of the positive results were from hospitalized patients (81.3%) and 3 (18.7%) from outpatients. The mean age of inpatients was 72.9 years (ranging from 47 to 88). All patients had received 2 or more antimicrobial agents (most of them beta-lactams) 2 months before the appearance of diarrhea. There was one patient who had received only chemotherapy. The prevalence of CDAD in this study was less than in others previously reported. This difference may be due to the fact that not all general practitioners include testing for C. difficile when the patient with diarrhea had previously received antibiotics. More educational programs should be directed to all physicians, concerning the role of C. difficile as an important enteric pathogen in patients who have undergone treatment with antimicrobial or chemotherapeutic agents.


Asunto(s)
Proteínas Bacterianas , Clostridioides difficile/aislamiento & purificación , Infección Hospitalaria/epidemiología , Enterocolitis Seudomembranosa/epidemiología , Adulto , Anciano , Anciano de 80 o más Años , Atención Ambulatoria , Antibacterianos/efectos adversos , Argentina/epidemiología , Toxinas Bacterianas/análisis , Técnicas de Tipificación Bacteriana , Preescolar , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/microbiología , Medios de Cultivo , Utilización de Medicamentos , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/microbiología , Heces/microbiología , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Sobreinfección , Población Urbana
10.
Rev. argent. microbiol ; Rev. argent. microbiol;33(2): 101-107, abr.-jun. 2001.
Artículo en Español | LILACS | ID: lil-332494

RESUMEN

Clostridium difficile has been recognized as the most important enteric pathogen of nosocomial antibiotic-associated diarrhea (CDAD) in adults from industrialized countries. The importance of C. difficile as a cause of diarrhea in ambulatory patients appears underestimated or under-recognized. Since the 1980's, outbreaks of CDAD have been increasingly reported, but there are few data available in Argentina. We developed a retrospective study to provide some information about CDAD in our country. From July 1998 to November 1999, a total of 245 fecal specimens from hospitalized and some ambulatory patients were tested in order to confirm the diagnosis of CDAD. C. difficile cytotoxin (toxin B) was identified by detecting its cytopathic effect on monolayers of McCoy culture cells. For culture and isolation of C. difficile, stool samples were prepared by ethanol shock prior to plating onto a selective medium which contained blood, cefoxitin and fructose. Of the 245 samples, 14 (5.8) were identified as positive by the cell cytotoxicity assay. Using the criteria of isolation of cytotoxigenic C. difficile positivity increased to 6.5 (16 samples). Thirteen of the positive results were from hospitalized patients (81.3) and 3 (18.7) from outpatients. The mean age of inpatients was 72.9 years (ranging from 47 to 88). All patients had received 2 or more antimicrobial agents (most of them beta-lactams) 2 months before the appearance of diarrhea. There was one patient who had received only chemotherapy. The prevalence of CDAD in this study was less than in others previously reported. This difference may be due to the fact that not all general practitioners include testing for C. difficile when the patient with diarrhea had previously received antibiotics. More educational programs should be directed to all physicians, concerning the role of C. difficile as an important enteric pathogen in patients who have undergone treatment with antimicrobial or chemotherapeutic agents.


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Adulto , Persona de Mediana Edad , Clostridioides difficile , Enterocolitis Seudomembranosa , Infección Hospitalaria/epidemiología , Anciano de 80 o más Años , Atención Ambulatoria , Antibacterianos/efectos adversos , Argentina , Toxinas Bacterianas , Técnicas de Tipificación Bacteriana , Medios de Cultivo , Utilización de Medicamentos , Enterocolitis Seudomembranosa , Heces , Hospitalización , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/microbiología , Prevalencia , Estudios Retrospectivos , Sobreinfección , Población Urbana
11.
Rev. argent. microbiol ; Rev. argent. microbiol;33(2): 101-107, abr.-jun. 2001.
Artículo en Español | BINACIS | ID: bin-6759

RESUMEN

Clostridium difficile has been recognized as the most important enteric pathogen of nosocomial antibiotic-associated diarrhea (CDAD) in adults from industrialized countries. The importance of C. difficile as a cause of diarrhea in ambulatory patients appears underestimated or under-recognized. Since the 1980s, outbreaks of CDAD have been increasingly reported, but there are few data available in Argentina. We developed a retrospective study to provide some information about CDAD in our country. From July 1998 to November 1999, a total of 245 fecal specimens from hospitalized and some ambulatory patients were tested in order to confirm the diagnosis of CDAD. C. difficile cytotoxin (toxin B) was identified by detecting its cytopathic effect on monolayers of McCoy culture cells. For culture and isolation of C. difficile, stool samples were prepared by ethanol shock prior to plating onto a selective medium which contained blood, cefoxitin and fructose. Of the 245 samples, 14 (5.8) were identified as positive by the cell cytotoxicity assay. Using the criteria of isolation of cytotoxigenic C. difficile positivity increased to 6.5 (16 samples). Thirteen of the positive results were from hospitalized patients (81.3) and 3 (18.7) from outpatients. The mean age of inpatients was 72.9 years (ranging from 47 to 88). All patients had received 2 or more antimicrobial agents (most of them beta-lactams) 2 months before the appearance of diarrhea. There was one patient who had received only chemotherapy. The prevalence of CDAD in this study was less than in others previously reported. This difference may be due to the fact that not all general practitioners include testing for C. difficile when the patient with diarrhea had previously received antibiotics. More educational programs should be directed to all physicians, concerning the role of C. difficile as an important enteric pathogen in patients who have undergone treatment with antimicrobial or chemotherapeutic agents.(AU)


Asunto(s)
Humanos , Masculino , Femenino , Preescolar , Adulto , Persona de Mediana Edad , Anciano , Clostridioides difficile/aislamiento & purificación , Infección Hospitalaria/epidemiología , Enterocolitis Seudomembranosa/epidemiología , Anciano de 80 o más Años , Atención Ambulatoria , Antibacterianos/efectos adversos , Argentina/epidemiología , Toxinas Bacterianas/análisis , Técnicas de Tipificación Bacteriana , Infección Hospitalaria/diagnóstico , Infección Hospitalaria/microbiología , Medios de Cultivo , Utilización de Medicamentos , Enterocolitis Seudomembranosa/diagnóstico , Enterocolitis Seudomembranosa/microbiología , Heces/microbiología , Hospitalización , Prevalencia , Estudios Retrospectivos , Sobreinfección , Población Urbana
12.
Infect Dis Obstet Gynecol ; 9(1): 17-22, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11368254

RESUMEN

OBJECTIVE: To determine the prevalence of Gardnerella vaginalis, anaerobic bacteria and Mycoplasma hominis in vaginal specimens of women with and without bacterial vaginosis (BV) as well as to determine the sensitivity and specificity of the direct sialidase assay of vaginal fluid as a rapid test for diagnosing this syndrome. METHODS: Vaginal cultures were obtained from 109 nonpregnant women (mean age 33 +/- 7.1 years), 47 of them with clinical signs of BV (BV+) and 62 of them without BV (BV-). In addition, we determined the vaginal sialidase activity in both groups, which may serve as a feature of this syndrome. RESULTS: Anaerobic bacteria were isolated in 91% and 18% of the BV+ and BV- groups, respectively (p < 0.001). Peptostreptococcus spp., Prevotella bivia and Porphyromonas spp. were strongly associated with BV. P. bivia and Prevotella spp. represented 44% of all the anaerobes isolated in the BV+ group. All the isolated P. bivia strains presented sialidase activity. G. vaginalis and M. hominis were isolated in 76% and 42% of the BV+ and 1% and 0% of the BV- women, respectively (p < 0.001). Mobiluncus morphotypes were observed in 34% of the BV+ and 0% of BV- women. Sensitivity, specificity, positive predictive value and negative predictive value of sialidase activity were 81%, 94%, 90% and 86%, respectively. CONCLUSIONS: Our data demonstrate a strong association between G. vaginalis, M. hominis, and P. bivia and BV. Sialidase activity and Gram stain of vaginal fluid represent accurate methods for diagnosing BV.


Asunto(s)
Gardnerella vaginalis/aislamiento & purificación , Infecciones por Mycoplasma/microbiología , Mycoplasma hominis/aislamiento & purificación , Neuraminidasa/metabolismo , Vagina/microbiología , Vaginosis Bacteriana/microbiología , Adulto , Bacterias Anaerobias/enzimología , Bacterias Anaerobias/aislamiento & purificación , Femenino , Gardnerella vaginalis/enzimología , Humanos , Infecciones por Mycoplasma/enzimología , Mycoplasma hominis/enzimología , Vagina/enzimología , Vaginosis Bacteriana/enzimología
13.
Rev. argent. microbiol ; Rev. argent. microbiol;33(2): 101-7, 2001 Apr-Jun.
Artículo en Español | BINACIS | ID: bin-39470

RESUMEN

Clostridium difficile has been recognized as the most important enteric pathogen of nosocomial antibiotic-associated diarrhea (CDAD) in adults from industrialized countries. The importance of C. difficile as a cause of diarrhea in ambulatory patients appears underestimated or under-recognized. Since the 1980s, outbreaks of CDAD have been increasingly reported, but there are few data available in Argentina. We developed a retrospective study to provide some information about CDAD in our country. From July 1998 to November 1999, a total of 245 fecal specimens from hospitalized and some ambulatory patients were tested in order to confirm the diagnosis of CDAD. C. difficile cytotoxin (toxin B) was identified by detecting its cytopathic effect on monolayers of McCoy culture cells. For culture and isolation of C. difficile, stool samples were prepared by ethanol shock prior to plating onto a selective medium which contained blood, cefoxitin and fructose. Of the 245 samples, 14 (5.8


) were identified as positive by the cell cytotoxicity assay. Using the criteria of isolation of cytotoxigenic C. difficile positivity increased to 6.5


(16 samples). Thirteen of the positive results were from hospitalized patients (81.3


) and 3 (18.7


) from outpatients. The mean age of inpatients was 72.9 years (ranging from 47 to 88). All patients had received 2 or more antimicrobial agents (most of them beta-lactams) 2 months before the appearance of diarrhea. There was one patient who had received only chemotherapy. The prevalence of CDAD in this study was less than in others previously reported. This difference may be due to the fact that not all general practitioners include testing for C. difficile when the patient with diarrhea had previously received antibiotics. More educational programs should be directed to all physicians, concerning the role of C. difficile as an important enteric pathogen in patients who have undergone treatment with antimicrobial or chemotherapeutic agents.

14.
Rev. argent. microbiol ; Rev. argent. microbiol;33(3): 133-40, 2001 Jul-Sep.
Artículo en Español | BINACIS | ID: bin-39430

RESUMEN

The aim of this study was to carry out a microbiological evaluation of sites with and without clinical evidence of moderate and severe periodontitis and their correlation with clinical parameters. A total of 52 disease sites and 10 healthy sites were selected according to clinical criteria. The following clinical indexes were measured for all the sites: plaque index, gingival index, blood on probing, depth on probing and insertion level. Samples of subgingival plaque were collected for culture and for differential counts of microbial morphotypes. In disease sites the most frequently isolated were: Prevotella intermedia/nigrescens (65


), Porphyromonas gingivalis (23


), Actinobacillus actinomycetemcomitans (23


), Fusobacterium nucleatum (10


) and Peptostreptococcus sp. (31


). The aerobic gram-positive microflora was predominant in healthy sites. Significant differences were observed in microbial morphotypes between healthy and disease sites: cocci 18.71


and 78.90


, motile rods 46.12


and 16.70


, total spirochetes 26.48


and 2.80


, respectively. The presence of motile rods, spirochetes and P. intermedia/nigrescens were the parameters with most sensitivity to suspect periodontal disease. There were significant differences in the subgingival microflora between healthy and disease sites in patients with moderate and severe periodontitis.

15.
Diagn Microbiol Infect Dis ; 36(2): 91-3, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10705049

RESUMEN

We compared the performance of several phenotypic tests to detect methicillin-resistant Staphylococcus aureus, with special focus on borderline strains. The reliability of the agar screen oxacillin and BBL Crystal tests was asserted for all methicillin-susceptible (n = 25), -resistant (n = 29) and borderline beta-lactamase-hyperproducer (n = 10) strains. Whereas these tests failed to detect 4 of 5 rare borderline strains containing few cells with high-level methicillin resistance (i.e., a frequency of 10(-7)-10(-8)), a "two-temperature" disk diffusion method, performed simultaneously at 35 and 42 degrees C, detected all of such strains.


Asunto(s)
Resistencia a la Meticilina/genética , Staphylococcus aureus/efectos de los fármacos , Ampicilina/farmacología , Recuento de Colonia Microbiana , Humanos , Oxacilina/farmacología , Penicilinas/farmacología , Fenotipo , Reacción en Cadena de la Polimerasa , Sensibilidad y Especificidad , Cloruro de Sodio/farmacología , Staphylococcus aureus/genética
16.
Acta Odontol Latinoam ; 13(2): 73-86, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-15211927

RESUMEN

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.


Asunto(s)
Placa Dental/prevención & control , Bolsa Periodontal/microbiología , Adulto , Aggregatibacter actinomycetemcomitans/aislamiento & purificación , Índice de Placa Dental , Raspado Dental , Femenino , Fusobacterium nucleatum/aislamiento & purificación , Humanos , Masculino , Persona de Mediana Edad , Índice Periodontal , Bolsa Periodontal/terapia , Porphyromonas gingivalis/aislamiento & purificación , Prevotella intermedia/aislamiento & purificación , Spirochaetales/aislamiento & purificación
17.
Acta odontol. latinoam ; Acta odontol. latinoam;13(2): 73-86, 2000.
Artículo en Español | LILACS-Express | LILACS, BINACIS | ID: biblio-1157632

RESUMEN

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.

18.
Acta odontol. latinoam ; Acta odontol. latinoam;13(2): 73-86, 2000.
Artículo en Inglés | BINACIS | ID: bin-39588

RESUMEN

The aim of this study was to carry out a short term evaluation of the effect of supragingival plaque control on the subgingival microflora and gingivoperiodontal tissues in patients with moderate and severe periodontitis. A total of 92 sites from 23 patients were studied; patients ranged between 35 and 60 years of age (x 46.4 +/- 1.71). Plaque Index (PI), Gingival Index (GI), Bleeding on Probing (BP), Probing Depth (PD), and Attachment Level (AL) were measured. Subgingival microflora of the same sites was studied by dark field microscopy, and cultures in non-selective and selective media for Actinobacillus actinomycetemcomitans (Aa), Prevotella intermedia/nigrescens (Pi/n), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). The patients were included in a supragingival plaque control program which included oral hygiene training and assessment, and professional control of supragingival plaque and calculus. After 28 days, measurement of clinical parameters and the microbiological study were repeated. The sites were divided according to baseline PD values into: Group 1 (5 mm), Group 2 (6 mm) and Group 3 (> or = 7 mm). Results revealed a significant reduction in PI scores, GI scores, PB and PD in groups 2 and 3. No significant difference in AL was observed in any of the three groups. PI scores were found to decrease significantly in group 1, and GI scores, BP and PD tended to decrease. A significant increase in coccoid cells and a significant decrease in motile rods and spirochetes, both small and total, was observed in groups 2 and 3. Group 1 showed a significant decrease in medium and total spirochetes. At the end of the study, a significant decrease in Pi/n was found in all three groups. Significant decreases were found in Pg and Fn in Groups 3 and 2 respectively. Although it holds true that supragingival plaque control reduced a potentially pathogenic subgingival microbiota, this effect was not sufficient to be compatible with healthy gingivoperiodontal tissues.

19.
Prensa méd. argent ; Prensa méd. argent;86(7): 649-52, sept. 1999. tab
Artículo en Español | LILACS | ID: lil-242299

RESUMEN

We conducted a comparative microbiological trial to determine the characteristics of urinary tract infections (UTI) in ddifferente population groups. Infections of the urinary tract are among the most commonly encountered of all bacterial infections: they are experienced by children as well as by adults and in both ambulatory and hospitalized patients. The frequency of urinary infections increases with the age, mainly in females, even with normal urinary tract. the term significant bacteriuria refers to the presene of bacteria more than 10 elevado a la quinta colony-forming units per milliter. Asymptomatic (covert) bacteriuria is the presence of significant bacteeriiuria in the absence of any simpotoms attributable to infection. Most infections are caused by Enterobacteriaceae with higher prevalence of Escherichia coli. Diagnosis of UTI requires culture of urine, but urine microscopy for bacteriiuria may provide important information before culture results are available. About 40 por ciento of nosocomial infections involve the urinary tract, with most associated with indwelling urethral catheters. They are the most common source of gram-negative bacteriuria in hospitalized patients. Major risk groups have been associated with an increased incidence of UTI: female sex, advanced age and severe general debility. We conducted a randomized study of 2,730 episodesof significant bacteriuria to determine the prevalence and antimicrobial susceptibility of the bacteriologic isolations and therapeutic responses to antimicrobial therapy


Asunto(s)
Niño , Adolescente , Adulto , Infecciones Bacterianas/epidemiología , Microbiología/estadística & datos numéricos , Infecciones Urinarias/epidemiología
20.
Prensa méd. argent ; 86(7): 649-52, sept. 1999. tab
Artículo en Español | BINACIS | ID: bin-15064

RESUMEN

We conducted a comparative microbiological trial to determine the characteristics of urinary tract infections (UTI) in ddifferente population groups. Infections of the urinary tract are among the most commonly encountered of all bacterial infections: they are experienced by children as well as by adults and in both ambulatory and hospitalized patients. The frequency of urinary infections increases with the age, mainly in females, even with normal urinary tract. the term significant bacteriuria refers to the presene of bacteria more than 10 elevado a la quinta colony-forming units per milliter. Asymptomatic (covert) bacteriuria is the presence of significant bacteeriiuria in the absence of any simpotoms attributable to infection. Most infections are caused by Enterobacteriaceae with higher prevalence of Escherichia coli. Diagnosis of UTI requires culture of urine, but urine microscopy for bacteriiuria may provide important information before culture results are available. About 40 por ciento of nosocomial infections involve the urinary tract, with most associated with indwelling urethral catheters. They are the most common source of gram-negative bacteriuria in hospitalized patients. Major risk groups have been associated with an increased incidence of UTI: female sex, advanced age and severe general debility. We conducted a randomized study of 2,730 episodesof significant bacteriuria to determine the prevalence and antimicrobial susceptibility of the bacteriologic isolations and therapeutic responses to antimicrobial therapy


Asunto(s)
Estudio Comparativo , Niño , Adolescente , Adulto , Microbiología/estadística & datos numéricos , Infecciones Bacterianas/epidemiología , Infecciones Urinarias/epidemiología
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