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C Betriu

Publications and source records attributed to C Betriu.

18 recordsLinked to original sources
PubMed1999

Incidence of erythromycin resistance in Streptococcus pyogenes: a 10-year study.

We studied the evolution of susceptibility of Streptococcus pyogenes isolated in our hospital from 1987 to 1996. Susceptibility to penicillin, ampicillin, cefotaxime, cefuroxime, imipenem, erythromycin, clindamycin, tetracycline, vancomycin, ciprofloxacin, rifampin, and chloramphenicol was determined by the National Committee for Clinical Laboratory Standards broth microdilution method. Differentiation of phenotypes of erythromycin-resistant strains was performed using the double-disc method. All isolates remained very susceptible in vitro to penicillin and all of the other beta-lactam agents tested. Between 1987 and 1995 the incidence of erythromycin resistant strains remained below 5%; the difference in the resistance rate between 1995 (2.6%) and 1996 (17.1%) was statistically significant. The macrolide resistance M phenotype was the most frequent. The isolation rates of tetracycline-resistant strains increased from 2.2% in 1987 to 11.2% in 1988. The marked increase in the incidence of erythromycin resistance observed in our area warrants periodic surveillance of antibiotic susceptibility of S. pyogenes isolates and emphasizes the need to control outpatient antibiotics. The preponderance of the M phenotype may have implications in the choice of antibiotic.

Anti-Bacterial Agents↗
PubMed1999

In-vitro susceptibilities of species of the Bacteroides fragilis group to newer beta-lactam agents.

The in-vitro activities of imipenem and four beta-lactam-beta-lactamase inhibitor combinations were tested against 816 strains of the Bacteroides fragilis group, and compared with other anti-anaerobic agents. None of the strains was resistant to metronidazole, and only one was resistant to chloramphenicol. Mezlocillin and piperacillin were moderately active, while clindamycin was the least active. Rates of resistance varied between various species. The new beta-lactam agents tested showed excellent activity; piperacillin-tazobactam and imipenem were the most active. The emergence of strains that are resistant to these agents, observed in this study, suggests there is a need to perform periodic antimicrobial susceptibility tests.

Amoxicillin↗
PubMed1999

Activities of new antimicrobial agents (trovafloxacin, moxifloxacin, sanfetrinem, and quinupristin-dalfopristin) against Bacteroides fragilis group: comparison with the activities of 14 other agents.

The antimicrobial activities of trovafloxacin, moxifloxacin, sanfetrinem, quinupristin-dalfopristin, and 14 other antimicrobial agents against 218 Bacteroides fragilis group strains were determined. A group of 10 imipenem-resistant strains were also tested. Imipenem, meropenem, and sanfetrinem had the lowest MICs of all of the beta-lactams. Quinupristin-dalfopristin inhibited all of the strains at 2 microg/ml. Overall, the MICs of trovafloxacin and moxifloxacin for 90% of the strains tested were 1 and 2 microg/ml, respectively.

Anti-Bacterial Agents↗
PubMed1995

[Beta-lactamase producing bacteria in the pharyngeal flora of patients with acute pharyngitis].

BACKGROUND: Production of beta-lactamase by normal pharyngeal flora could account for penicillin treatment failure in patients with acute streptococcal pharyngitis. The aim of the present investigation was to study the beta-lactamase-producing bacteria (BLPB) in 58 patients with acute pharyngitis, and to investigate the impact of two antibiotics, amoxycillin vs amoxycillin/clavulanic acid in the pharyngeal microflora. METHODS: Rapid antigen detection tests for S. pyogenes and standard microbiologic cultures were performed on simultaneously obtained throat swabs from each enrolled patient. Patients with group A streptococcal pharyngitis (GASP) were randomized in two groups: patients treated with 10 days of oral amoxycillin (group I), and patients treated with 10 days of oral amoxicyllin/clavulanic acid (group II). Patients without GASP and without antibiotic treatment were considered as controls (group III). Cultures were repeated 15 days following the first culture. All of them were processed for aerobic and anaerobic organisms. RESULTS: S. pyogenes was recovered in 25 patients (43.1%) and BLPB were isolated in 64% of the treated patients and in 78% of the non-treated control patients. We observed that the number of patients harboring BLPB did not change significantly in the untreated control group. After treatment we detected a similar increase in the number of patients harboring BLPB in groups I and II. In the present study BLPB were found in more than 70% of the patients and the failure rate was less than 10%. CONCLUSIONS: The results of this study indicate that production of beta-lactamase by pharyngeal organisms does not fully explain the failures of penicillin therapy for acute streptococcal pharyngitis.

Acute Disease↗
PubMed1994

Antibiotic resistance and penicillin tolerance in clinical isolates of group B streptococci.

The aim of this study was to determine the susceptibility patterns of 100 group B streptococcal strains isolated in our hospital and to ascertain tolerance to penicillin by determining quantitative killing curves. We found two strains with intermediate susceptibility to penicillin and eight strains to ampicillin. Seventeen isolates were tolerant to penicillin, with bacterial counts decreasing 2 to 3 log during the first 8 h but still above 10(2) CFU/ml after 24 h. The kinetic study shows that penicillin tolerance is not rare among group B streptococci isolated in our hospital.

Ampicillin Resistance↗
PubMed1994

Hemorrhagic gastroesophageal ulceration by pulmonary infection in extrahepatic cholestatic pigs.

We developed a biliary and pulmonary microbiologic study in 22 Large-White pigs that underwent bile-duct ligation in order to demonstrate that sepsis has a biliary and pulmonary origin which may be involved in the gatroesophageal pathology. All the pigs died at 18.2 +/- 8.9 days of the post-operative period. The cause of death was hemorrhagic ulceration of the gastroesophageal region in 36.3% (n = 8) of the animals that also presented multiple bilateral miliary lung abscesses. High infestation rates with intestinal germs were found in the bile and lung. In conclusion, the experimental model of extrahepatic cholestasis in the Large-White pig could be useful for the study of etiopathogenic mechanisms by which the pulmonary infection produces a hemorrhagic gastroesophageal ulceration considered as stress ulcer.

Animals↗
PubMed1993

Antibiotic susceptibility of group A streptococci: a 6-year follow-up study.

The susceptibility patterns of group A streptococci over the last 6 years in our hospital were determined. Since our last study, carried out in 1987, all isolates have remained very susceptible in vitro to penicillin and all of the other beta-lactam agents tested. We observed resistance to erythromycin, clindamycin, tetracycline, and ofloxacin. The prevalence of erythromycin-resistant group A streptococci did not change appreciably throughout the study period.

Anti-Bacterial Agents↗
PubMed1992

Changes in the susceptibility of Bacteroides fragilis group organisms to various antimicrobial agents 1979-1989.

The in vitro activity of metronidazole, chloramphenicol, clindamycin and 11 beta-lactam antibiotics against 135 clinical isolates of the Bacteroides fragilis group was compared. In addition, changes in the resistance patterns of members of the Bacteroides fragilis group isolated at the Hospital Universitario San Carlos in Madrid, Spain, between 1979 and 1989 were documented. The most active beta-lactam drugs were imipenem and beta-lactamase inhibitor combinations. In 1989, however, two strains were found to be resistant to imipenem and to all other beta-lactam agents tested. There was no emergence of resistance to metronidazole. Chloramphenicol was very effective: only one resistant strain was detected in 1979 and no chloramphenicol-resistant isolates were found during the rest of the study period. An outbreak of clindamycin resistance was noted in 1982, and the first cefoxitin resistant strains were recovered in 1985. The changing patterns of susceptibility of anaerobic bacteria to antimicrobial agents and the emergence of Bacteroides fragilis strains resistant to new beta-lactam agents suggest that periodic antimicrobial susceptibility tests should be performed in order to guide the selection of antimicrobial agents for therapy.

Anti-Bacterial Agents↗
PubMed1990

Susceptibilities of species of the Bacteroides fragilis group to 10 antimicrobial agents.

A total of 94 clinical isolates of the Bacteroides fragilis group was tested for susceptibility to metronidazole, chloramphenicol, clindamycin, cefoxitin, cefotetan, cefmetazole, moxalactam, mezlocillin, amoxicillin-clavulanic acid, and imipenem. All the strains tested were susceptible to imipenem, metronidazole, amoxicillin-clavulanic acid, and chloramphenicol. The rate of resistance to clindamycin was 21%. The results of this study demonstrate a difference in resistance rates from one species of the B. fragilis group to another.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Bacteremia caused by Bacteroides. An analysis of 50 episodes].

During the 32 months between October 1984 and May 1987 there were 72,800 admissions in our center; 31,523 blood cultures were undertaken and in 3,831 of them (11.5%) at least one significant organism was recovered; 6.7% of blood cultures yielded anaerobic bacteria, and 3.1% Bacteroides spp. In the 1,478 instances of bacteremia recorded during that period, the relative frequencies of bacteremia by anaerobic bacteria and by Bacteroides were 8.6% and 3.9%, respectively. In overall 50 Bacteroides bacteremias (47 due to Bacteroides fragilis and 3 to Bacteroides spp), 32 (64%) were hospital acquired and 14 (28%) postsurgical. Their most common source was the abdominal cavity (25, 50%), followed by the skin and soft tissues (7, 14%), feminine pelvis (4, 8%), miscellaneous (8, 16%), and unknown (7, 14%). Fifteen bacteremias (30%) were polymicrobial, 20 (40%) were associated with septic shock, and 15 (30%) with renal failure. Overall mortality rate was 52%, and that directly attributable to bacteremia was 32%. Poor prognostic predictors included the source from a perforated viscus, septic shock, renal failure or gastrointestinal hemorrhage, and the absence of adequate antimicrobial therapy.

Adolescent↗
PubMedDate not supplied

[Carrier state of groups A, B, C, and D beta-hemolytic streptococci].

BACKGROUND: Streptococci group A is the most frequently isolated pathogen in the cases of acute pharyngotonsilitis in school-aged children. Hemolytic streptococci B, which are not of group A, have recently been described as a cause of pharyngotonsilitis. A study was carried out in school children in primary school with the aim of knowing the frequency of the state of pharyngeal carriers of streptococci in groups A, B, C and G. METHODS: A total of 347 children with ages ranging from 4 to 14 years of age were included in the study in which a pharyngeal exudate was obtained to investigate the presence of hemolytic streptococci B. RESULTS: The prevalence of streptococci group A in all the age groups studied was of 11.52% being significantly greater (40.47%) among children of preschool age (4-6 years). The prevalence of streptococci group C was 2.3% with no carriers of groups B or G being observed. CONCLUSIONS: The results of this study are in agreement with the literature reviewed in which asymptomatic carriers of streptococci group A were found to be principally school aged children who are those who most frequently have acute pharyngotonsilitis. Neither the pathogenicity of hemolytic streptococci B, which are not of group A, nor their epidemiologic implications are totally clear.

Adolescent↗