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E Cambau

Publications and source records attributed to E Cambau.

At least 19 recordsLinked to original sources
PubMed2002

[Evolution of susceptibility of aerobic gram-negative aerobic bacilli to quinolones and fluoroquinolones in a university hospital (1992-2000)].

Susceptibility to quinolones of aerobic gram-negative bacilli was assessed in a 2000-bed university hospital from 1992 to 2000. There was a significant downward trend in the rate of susceptibility to nalidixic acid (Nal) for Enterobacteriaceae as a whole from 1992 to 2000 (86% vs 82%), and E. coli (92% vs 84%), and an upward trend for K. pneumoniae (74% vs 82%), the latter being related to the control of the spread of epidemic ESBL producing strains. The overall susceptibility of Enterobacteriaceae to ciprofloxacin (Cip) paralleled the susceptibility to Nal: decreased susceptibility for Enterobacteriaceae as a whole (96% vs 89%) and E. coli (99% vs 91%). A clear decrease in the level of susceptibility to Cip occurred during the study period among the Nal-resistant strains as demonstrated by the decrease in the median zone diameter (D) observed among the Nal-resistant strains of E. coli (26 mm in 1992 vs 19 mm in 1998-2000). The zone diameter distribution pattern changed from an unimodal distribution in 1992 to a trimodal distribution in 2000 secondary to the occurrence of a population of resistant strains (D = 13 mm) and of a highly resistant population (D = 6 mm). Finally, the susceptibility to Cip of P. aeruginosa strains remained stable around 62% throughout the study period.

4-Quinolones↗
PubMed2001

Detection of embB codon 306 mutations in ethambutol resistant Mycobacterium tuberculosis directly from sputum samples: a low-cost, rapid approach.

Substitutions of codon 306 in the gene embB are the most common mutations found in ethambutol resistant Mycobacterium tuberculosis. The characterization of these mutations has been hampered by the need for prior cultivation of the mycobacteria, or the need for DNA sequencing, or both. Here, we describe a simple and culture-independent technique to detect embB codon 306 mutations directly from sputum samples, requiring little more than a PCR machine and a simple agarose minigel. There is no need for labelled probes or DNA sequencing. In a preliminary test of feasibility, interpretable results were obtained from 21 of 24 selected sputum samples, 12 of which were determined to contain ethambutol resistant M. tuberculosis after culture. All of six samples with embB codon 306 mutations were correctly identified. Although an exact validation of this technique is beyond the scope of this technical report, we conclude from well-known embB codon 306 mutation prevalence figures that approximately one half of EMB resistant cases could already be predicted within 2 working days, with little equipment or hands-on time needed, instead of weeks required for conventional resistance testing.

Chemistry, Clinical↗
PubMed2001

Trends in quinolone susceptibility of Enterobacteriaceae among inpatients of a large university hospital: 1992-98.

OBJECTIVES: To assess trends in quinolone susceptibility of Enterobacteriaceae isolated in a large university hospital. METHODS: Between 1992 and 1998, bacterial isolates were collected each year during a 3-month period to evaluate annual changes in susceptibility. In addition, the activities of fluoroquinolones (pefloxacin, norfloxacin, ofloxacin, ciprofloxacin) against nalidixic acid-resistant strains were determined by disk diffusion and MIC methodologies during the first and last year of the study. RESULTS: The susceptibility of Enterobacteriaceae to nalidixic acid was unchanged between 1992 and 1998 (86% versus 85%). However, at the species level, the susceptibility rates to nalidixic acid decreased for Escherichia coli from 92% to 89%, and for Enterobacter cloacae from 87% to 82%. In contrast, there was a 10% increase in the nalidixic acid susceptibility rates for Klebsiella pneumoniae (74% versus 83%), which was thought to be due to the control of the spread of epidemic extended-spectrum beta-lactamase (ESBL)-producing strains. The overall susceptibility of the Enterobacteriaceae to the fluoroquinolones remained high during the study period, greater than 90% in the case of ciprofloxacin. However, nalidixic acid-resistant Escherichia coli showed decreased susceptibility to ciprofloxacin between 1992 and 1998, as reflected by a decrease in median zone diameter (26 mm to 19 mm), an increase in MIC(50) (0.25 mg/L to 1 mg/L) and a shift in MIC distribution (unimodal in 1992 to bimodal in 1998). This has resulted in the reduced susceptibility of Escherichia coli to fluoroquinolones between 1992 and 1998 (pefloxacin, 95-90%; ciprofloxacin, 99-95%). CONCLUSIONS: The susceptibility of Escherichia coli to quinolones has decreased, and the level of susceptibility of the resistant strains has increased over the 7-year study period.

Anti-Infective Agents↗
PubMed2000

Impact of highly active antiretroviral therapy on onset of Mycobacterium avium complex infection and cytomegalovirus disease in patients with AIDS.

OBJECTIVES: To assess the impact of highly active antiretroviral therapy (HAART) on the onset of first disseminated Mycobacterium avium complex (MAC) infection and first cytomegalovirus (CMV) disease episode in HIV-infected at-risk patients. METHODS: The incidence of the two infections occurring in at-risk patients was calculated for two periods (January 1995-June 1996 and July 1996-December 1997) using the database of the HIV-infected patients followed in the Infectious Diseases Department at the Pitié-Salpêtrière Hospital in Paris. HAART was progressively introduced in late June 1996 in France. RESULTS: A total of 91 first disseminated MAC infections and 124 first CMV disease episodes were recorded. The incidence of first disseminated MAC infections fell from 13.4 per 100 person-years in the first 18-month period to 2.6 per 100 person-years in the second 18-month period. Similarly, the incidence of first CMV disease episodes fell from 20.9 to 3.5 per 100 person-years. Fourteen patients on HAART developed a first MAC infection, 12 (85.7%) within 2 months of starting HAART. Nineteen patients on HAART had a first CMV disease episode, 10 (52.6%) within 2 months of starting HAART. CONCLUSIONS: HAART led to a five-fold decrease in the incidence of first disseminated MAC infections and a six-fold decrease in first CMV disease episodes, although patients remain vulnerable to both diseases for approximately 2 months after starting HAART.

AIDS-Related Opportunistic Infections↗
PubMed2000

Mycobacterial growth indicator tube versus the proportion method on Löwenstein-Jensen medium for antibiotic susceptibility testing of Mycobacterium tuberculosis.

The Mycobacterial Growth Indicator Tube, a reliable system for detection of mycobacterial growth, was compared with the reference proportion method on Löwenstein-Jensen medium for antibiotic susceptibility testing of Mycobacterium tuberculosis. A total of 62 clinical strains and four reference strains of Mycobacterium tuberculosis were tested for susceptibility to streptomycin, isoniazid, rifampicin and ethambutol. Of these, 36 were susceptible to all four antibiotics and 30 were resistant to at least one of them. Tests were repeated in cases of discrepant results. When each drug/strain combination was considered separately, the overall agreement between the two methods was 96.5% (98.4% for streptomycin, 95.3% for isoniazid, 96.9% for rifampicin and 95.3% for ethambutol) with regard to the initial testing and 98.8% (100, 98.5, 98.5 and 98.4%, respectively) after repeated testing. When the results were considered strain by strain, the agreement was 86% after the initial testing and 95% after repeated testing. The results were obtained after a mean time of 9.5 days. These results suggest that the Mycobacterial Growth Indicator Tube is a reliable method for testing susceptibility of mycobacterial strains to first-line antituberculous drugs.

Antitubercular Agents↗
PubMed2000

Antibiotic susceptibility pattern of Mycobacterium marinum.

In vitro activities of 17 antibiotics against 53 clinical strains of Mycobacterium marinum, an atypical mycobacterium responsible for cutaneous infections, were determined using the reference agar dilution method. Rifampin and rifabutin were the most active drugs (MICs at which 90% of the isolates tested were inhibited [MIC(90)s], 0.5 and 0.6 microgram/ml, respectively). MICs of minocycline (MIC(90), 4 microgram/ml), doxycycline (MIC(90), 16 microgram/ml), clarithromycin (MIC(90), 4 microgram/ml), sparfloxacin (MIC(90), 2 microgram/ml), moxifloxacin (MIC(90), 1 microgram/ml), imipenem (MIC(90), 8 microgram/ml), sulfamethoxazole (MIC(90), 8 microgram/ml) and amikacin (MIC(90), 4 microgram/ml) were close to the susceptibility breakpoints. MICs of isoniazid, ethambutol, trimethoprim, azithromycin, ciprofloxacin, ofloxacin, and levofloxacin were above the concentrations usually obtained in vivo. For each drug, the MIC(50), geometric mean MIC, and modal MIC were very close, showing that all the strains had a similar susceptibility pattern. Percent agreement (within +/-1 log(2) dilution) between MICs yielded by the Etest method and by the agar dilution method used as reference were 83, 59, 43, and 24% for minocycline, rifampin, clarithromycin, and sparfloxacin, respectively. Reproducibility with the Etest was low, in contrast to that with the agar dilution method. In conclusion, M. marinum is a naturally multidrug-resistant species for which the agar dilution method is more accurate than the Etest for antibiotic susceptibility testing.

Anti-Bacterial Agents↗
PubMed2000

Twenty-five years of tuberculosis in a French university hospital: a laboratory perspective.

OBJECTIVE: To determine the impact of recent changes in the epidemiology of tuberculosis in France and other industrialised countries on the primary trends of tuberculosis case rates in a French university hospital. DESIGN: Descriptive study of all 4549 culture-positive tuberculosis cases hospitalised at Pitié-Salpêtrière Hospital between 1972 and 1996. RESULTS: From 1972, there was a decline of 5% per year in the tuberculosis case rate, which levelled off in 1983. The proportion of tuberculosis patients who were human immunodeficiency virus (HIV) positive increased from 2% in 1983 to 28% in 1990, and thereafter remained stable. The proportion of foreign-born tuberculosis patients also increased, from 40% in 1972 to 55% in 1985. These two changes affected drug resistance patterns. Drug resistance was more common among foreign-born than among French-born patients, whether previously treated or not. Resistance to rifampicin and multidrug resistance among previously untreated patients was highly related to HIV co-infection. Extrapulmonary sites of tuberculosis were more often smear-positive in HIV-positive than in non-HIV-positive patients (22.8% vs 12.6%), and bacteraemia was diagnosed almost exclusively in HIV-positive patients. CONCLUSION: The changes in clinical and bacteriological tuberculosis patterns at the hospital level over the last 25 years have paralleled those observed at national and international level in industrialised countries, including a slowing in the decrease in the case rate, due in part to the HIV epidemic, a higher proportion of foreign-born patients and an increase in drug resistance.

AIDS-Related Opportunistic Infections↗
PubMed1999

Culture-independent prediction of isoniazid resistance in Mycobacterium tuberculosis by katG gene analysis directly from sputum samples.

BACKGROUND: The molecular prediction of isoniazid (INH) resistance in Mycobacterium tuberculosis is hampered by the need for specialized equipment, expertise, high costs, a limited range of detectable mutations, or several of these factors. The rationale for the study was to find a practical alternative and to demonstrate generally valid problems. METHODS AND RESULTS: DNA extracted from decontaminated sputum pellets was used to amplify a 0.26 kb target sequence within the katG gene. Mutations of codon 315, frequently found in isoniazid-resistant isolates, could be discriminated in a simple agarose minigel format following an AciI digest of the nested polymerase chain reaction (PCR) product. Within a panel of 22 sputum samples, INH resistance could be predicted in 5 of 10 samples containing isoniazid-resistant M. tuberculosis. The protocol is robust, requires little expertise and no specialized equipment, and provides the test results within 2 days. CONCLUSION: The results show the feasibility to rapidly and easily detect mutations highly predictive of isoniazid resistance. Nevertheless, this, like any other molecular resistance prediction test, is affected by often neglected factors, including mutation prevalences, the phenomenon of heteroresistance, and a possible bias toward one's own method.

Antitubercular Agents↗
PubMed1999

Type II topoisomerase mutations in ciprofloxacin-resistant strains of Pseudomonas aeruginosa.

We determined the sequences of the quinolone resistance-determining regions of gyrA, gyrB, and parC genes for 30 clinical strains of Pseudomonas aeruginosa resistant to ciprofloxacin that were previously complemented by wild-type gyrA and gyrB plasmid-borne alleles and studied for their coresistance to imipenem (E. Cambau, E. Perani, C. Dib, C. Petinon, J. Trias, and V. Jarlier, Antimicrob. Agents Chemother. 39:2248-2252, 1995). In the present study, we found mutations in type II topoisomerase genes for all strains. Twenty-eight strains had a missense mutation in gyrA (codon 83 or 87). Ten of them had an additional mutation in parC (codon 80 or 84), including a novel mutation of Ser-80 to Trp, but all were fully complemented by a plasmid-borne wild-type gyrA allele. The remaining two strains harbored the first gyrB mutation described in P. aeruginosa, leading to the substitution of phenylalanine for serine 464. The strains which had two mutations in type II topoisomerase genes (i.e., gyrA and parC) were significantly more resistant to fluoroquinolones than those with a single mutation in gyrA or gyrB (geometric mean MICs of ciprofloxacin, 39.4 versus 10.9 microg/ml, P < 0.01; geometric mean MICs of sparfloxacin, 64.0 versus 22.6, P < 0. 01). No mutant with a parC mutation alone was observed, which favors DNA gyrase being the primary target for fluoroquinolones. These results demonstrate that gyrA mutations are the major mechanism of resistance to fluoroquinolones for clinical strains of P. aeruginosa and that additional mutations in parC lead to a higher level of quinolone resistance.

Amino Acid Sequence↗
PubMed1999

Evaluation of the new MB redox system for detection of growth of mycobacteria.

We evaluated a new mycobacterial culture system, MB Redox, for recovery rate and time to detection of mycobacteria from 742 consecutive respiratory specimens and compared the results to those found with Löwenstein-Jensen (LJ) medium. Twenty specimens (2.7%) were positive for M. tuberculosis: 17 on LJ medium and 19 in MB Redox, with 16 specimens positive in both media. In addition, 24 specimens (3.2%) were positive for nontuberculous mycobacteria (NTM), 20 on LJ medium, 18 in MB Redox, and 14 in both media. For M. tuberculosis, the mean times to detection were 28.9 days on LJ medium and 23.6 days in MB Redox, and for NTM, the mean times to detection were 40.6 days on LJ medium and 32.3 days in MB Redox.

Bronchoalveolar Lavage Fluid↗
PubMed1998

Correlation between quinolone susceptibility patterns and sequences in the A and B subunits of DNA gyrase in mycobacteria.

The in vitro activities of seven quinolones and the sequences of the quinolone resistance-determining regions (QRDR) in the A and B subunits of DNA gyrase were determined for 14 mycobacterial species. On the basis of quinolone activity, quinolones were arranged from that with the greatest to that with the least activity as follows: sparfloxacin, levofloxacin, ciprofloxacin, ofloxacin, pefloxacin, flumequine, and nalidixic acid. Based on MICs, the species could be organized into three groups: resistant (Mycobacterium avium, M. intracellulare, M. marinum, M. chelonae, M. abscessus [ofloxacin MICs, >/=8 microg/ml]), moderately susceptible (M. tuberculosis, M. bovis BCG, M. kansasii, M. leprae, M. fortuitum third biovariant, M. smegmatis [ofloxacin MICs, 0.5 to 1 microg/ml]), and susceptible (M. fortuitum, M. peregrinum, M. aurum [ofloxacin MICs, </=0.25 microg/ml]). Peptide sequences of the QRDR of GyrB were identical in all the species, including the amino acids at the three positions known to be involved in acquired resistance to quinolone, i.e., 426 (Asp), 447 (Arg), and 464 (Asn) (numbering system used for Escherichia coli). The last two residues could be involved in the overall low level of susceptibility of mycobacteria to quinolones since they differ from those found in the very susceptible E. coli (Lys-447 and Ser-464) but are identical to those found in the less susceptible Staphylococcus aureus and Streptococcus pneumoniae. Peptide sequences of the QRDR of GyrA were identical in all the species, except for the amino acid at position 83, which was an alanine in the two less susceptible groups and a serine in the most susceptible one, as in E. coli, suggesting that this amino acid is involved in the observed differences of quinolone susceptibility within the Mycobacterium genus.

Amino Acid Sequence↗
PubMed1998

Clinical utility of an amplification test based on ligase chain reaction in pulmonary tuberculosis.

We evaluated the sensitivity and specificity of a new semiautomated direct amplification test (DAT), the LCx-MTB, for the diagnosis of pulmonary tuberculosis (TB) and assessed its positive predictive value by focusing on patients with high clinical and radiologic suspicion of pulmonary TB. Respiratory tract specimens from 32 consecutive patients with high suspicion of active pulmonary TB (case patients) and from 204 control patients were cultured for Mycobacterium tuberculosis and tested by LCx-MTB. Sensitivity and specificity of LCx-MTB when compared with culture was, respectively, 80 and 98%. Pulmonary TB was confirmed in the 32 case patients without knowledge of the LCx results: 18 patients were smear- and culture-positive for M. tuberculosis, and all gave at least one specimen that was LCx-positive. Eight patients were smear-negative culture-positive, and seven gave at least one LCx-positive specimen. LCx-MTB was negative in all the specimens obtained from six patients with smear- and culture-negative TB. A positive LCx-MTB result in a smear negative specimen was 100% predictive that at least one of the case patients' specimens would yield M. tuberculosis. As a consequence, knowledge of the LCx-MTB results at the time of specimen collection could have hastened the start of the antituberculosis therapy in three (21%) smear-negative case patients and could have avoided unnecessary invasive diagnostic procedures in four (29%). We conclude that the sensitivity of LCx-MTB in detecting M. tuberculosis DNA in respiratory tract specimens is similar to other DATs, that LCx-MTB is a reliable test for confirmation of TB in smear-positive patients and that LCx-MTB could be beneficial as a diagnostic step in smear-negative patients with a high suspicion of pulmonary TB.

Antigens, Bacterial↗
PubMed1998

Use of DNA fingerprinting for primary surveillance of nosocomial tuberculosis in a large urban hospital: detection of outbreaks in homeless people and migrant workers.

SETTING: A large urban teaching hospital in the southeast of Paris. OBJECTIVE: Primary surveillance of nosocomial transmission of tuberculosis (TB) by systematic restriction fragment length polymorphism analysis (RFLP) of isolates (n = 161) recovered from smear-positive pulmonary TB patients identified from 1 March 1993 to 28 February 1994, and from all TB patients (with any form of tuberculous infection) identified from 1 March 1994 to 30 April 1995. RESULTS: Systematic RFLP analysis revealed 12 clusters of patients (n = 40) infected by strains of Mycobacterium tuberculosis showing matching RFLP patterns. None of the isolates were multidrug-resistant. Compared with non-clustered patients, clustered patients were more likely to be homeless (55% vs 19%, P < or = 0.001), or Africans living in hostels for migrant workers (20% vs 6%, P = 0.01), and had fewer previous admissions to hospital (12% vs 28%, P = 0.05). Further epidemiological investigations showed that the clustered TB cases actually resulted not from nosocomial transmission, but from transmission in the community, very likely in homeless shelters and hostels for migrant workers. CONCLUSION: No nosocomial transmission of TB was identified among the patients included during the study period. Systematic RFLP analysis using hospital-based sampling can detect the spread of TB in specific environments in the community where transmission is occurring.

Adult↗
PubMed1997

Nonradioactive single-strand conformation polymorphism analysis for detection of fluoroquinolone resistance in mycobacteria.

A simple, rapid, and nonradioactive method for routine detection of fluoroquinolone resistance in mycobacteria is described. A single-strand conformation polymorphism (SSCP) methodology, based on the use of mini-gels and silver staining of DNA, was optimized for the analysis of denatured DNA products obtained by polymerase chain reaction (PCR) from the gyrA gene involved in fluoroquinolone resistance in mycobacteria. The method was successfully applied to fluoroquinolone-susceptible and -resistant laboratory strains of Mycobacterium smegmatis and to clinical strains of Mycobacterium tuberculosis isolated from patients who developed resistance during the course of fluoroquinolone treatment.

Anti-Infective Agents↗