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J M Scheftel

Publications and source records attributed to J M Scheftel.

At least 19 recordsLinked to original sources
PubMed2006

Recurrent outbreaks of cryptosporidiosis associated with calves among students at an educational farm programme, Minnesota, 2003.

Enteric illness outbreaks among middle-/high-school students in consecutive semesters of an educational farm programme were investigated with retrospective cohort studies. During the first outbreak, 31/92 (34%) interviewed students were ill. Risk factors included participating in animal science class (RR 8.1, 95% CI 1.2-55.2) and contact with calves (RR 4.2, 95% CI 1.1-16.2). Stool samples from seven students and two calves yielded Cryptosporidium parvum. Students cared for animals in street clothes and practised poor hand washing. During the second outbreak, 37/81 (46%) interviewed animal science students were ill. Risk factors included having visible manure on hands, and wearing coveralls and boots. Stool samples from seven students and eight calves yielded C. parvum. Student hand washing was still inadequate. Coveralls/boots were cleaned infrequently and removed after hand washing. These outbreaks of cryptosporidiosis resulted from calf contact and inadequate hygiene practices. The failure to adequately implement recommended interventions contributed to the second outbreak.

Adolescent↗
PubMed2005

External quality assessment for molecular detection of Bordetella pertussis in European laboratories.

Although the PCR for the detection of Bordetella pertussis is routinely performed in diagnostic laboratories, no quality assessment program has so far been described. We report on the results obtained with two external quality assessment proficiency panels sent to European laboratories. The first proficiency panel contained a series of dilutions of three previously characterized B. pertussis clinical isolates and two negative controls. No false-positive results were reported by six laboratories providing seven data sets. The reported limits of detection of the three B. pertussis strains varied between 4 and 4,000, 9 and 9,000, and 3 and 30,000 CFU/ml, respectively. The second proficiency panel, composed of a series of dilutions of reference strains of B. pertussis, B. holmesii, B. hinzii, and B. bronchiseptica, as well as negative controls, was sent to nine laboratories. One laboratory reported a negative result for a sample and reported a B. parapertussis-positive sample to be positive for B. pertussis. By using the B. pertussis-specific target gene pertactin, one laboratory detected B. pertussis with 100% specificity. All other laboratories, which used IS481-based assays, reported positive results for the samples containing B. holmesii and B. bronchiseptica, species that have occasionally been recovered from human respiratory samples. These data show that the choice of the target gene is particularly critical for the species specificity of B. pertussis PCR assays.

Bordetella pertussis↗
PubMed1999

A new gel tube method for the direct detection, identification and susceptibility testing of bacteria in clinical samples.

We recently developed a simple new method which is designed to separate and concentrate bacteria from a sample by centrifugation in a gel system. Bacterial enzyme activity is then detected inside the gel without further manipulation using a colorimetric or fluorogenic substrate. The method provides a rapid, direct means of detecting bacteria in clinical samples, dispensing with the 24-h period normally required to isolate colonies on agar. Various applications of the method are described below, e.g. screening of negative urine samples, identification of Escherichia coli in urine samples, identification of Staphylococcus aureus in blood culture broths and detection of oxacillin-resistant S. aureus in blood culture broths. The advantages of the gel system and other applications are discussed.

Bacteriological Techniques↗
PubMed1999

Predominant Staphylococcus aureus isolated from antibiotic-associated diarrhea is clinically relevant and produces enterotoxin A and the bicomponent toxin LukE-lukD.

Staphylococcus aureus was isolated as the predominant or only isolate from cultures of stools of 60 patients over 2 years in a university hospital, leading to the collection of 114 isolates. Diarrhea was observed in 90% of the patients. Ninety-eight percent of the patients had received antibiotics in the month before the diarrhea. Ninety-two percent of the S. aureus isolates were methicillin resistant. S. aureus was encountered with antibiotic-associated diarrhea among 47 quite elderly patients affected or not affected by a gastrointestinal disease. Among the antimicrobial treatments, cessation of the previous therapy when possible or rapid application of oral vancomycin therapy was the most appropriate. Analysis of total DNA by pulsed-field gel electrophoresis revealed 27 different SmaI pulsotypes distributed in 15 clusters. The pulsotypes never differed for related isolates from a single patient, even if they originated from patients with bacteremia. S. aureus was not isolated as the predominant isolate in cultures of stools of 57 patients who received an antimicrobial treatment for more than 5 days without diarrhea. Occurence of production of both enterotoxin A and the bicomponent leucotoxin LukE-LukD by the S. aureus isolates was significantly different from that by random isolates. The results strongly suggest that when predominant in stool samples, S. aureus should be considered a possible etiologic agent for some cases of antibiotic-associated diarrhea.

Adolescent↗
PubMed1999

Analysis with a combination of macrorestriction endonucleases reveals a high degree of polymorphism among Bordetella pertussis isolates in eastern France.

From 1990 to 1996, routine screening for whooping cough identified 399 patients with a calmodulin-dependent adenylate cyclase-positive test result and yielded 69 Bordetella pertussis isolates. None of the patients were fully vaccinated, and most were less than 6 months old. Analysis of total DNA by pulsed-field gel electrophoresis (PFGE) after XbaI, SpeI, or DraI macrorestriction yielded 19, 15, and 5 different patterns, respectively, whereas ribotyping failed to demonstrate any strain polymorphism. Discrimination among the isolates was improved by combining the PFGE profiles. Some patterns were more frequent, but the corresponding patients were not clearly epidemiologically related. The patterns for two strains obtained during a 3-month period from patients who were neighbors differed by the length of a single DNA fragment. These data strongly suggest that one type of isolate is widely spread throughout the world and is carried by individuals other than patients who develop a true illness.

Bacterial Typing Techniques↗
PubMed1999

[Evaluation of Hemofast MRSA for identification of Staphylococcus aureus and detection of methicillin-resistance staphylococci, directly in blood culture broths].

The newly developed Hemofast MRSA system for Staphylococcus aureus identification and methicillin-resistant staphylococci (MRS) detection in blood culture broths was evaluated in 106 Bactec broths containing grapelike clusters of Gram-positive cocci. All 26 S. aureus positive broths were correctly identified by Hemofast MRSA within two hours, and 81% were identified within one hour. Sensitivity and specificity were both 100%. Accuracy of MRS detection was 100%, i.e., no discrepancies versus the agar diffusion method were found. When the 28 broths containing coagulase negative staphylococci (CNS) were tested using an inoculum ten fold larger than for S. aureus testing, a number of discrepancy were recorded. For 49 other broths containing CNS, accuracy was 98.5% when the test was interpreted based on the growth rate of the strain, according to the manufacturer's instructions. One broth containing S. epidermidis strain susceptible yielded a false result with Hemofast MRSA, indicating that it probably contained a contaminant. The other discrepancies occurred with specimens containing mixed populations with CNS or a Micrococcus strain. Most (85%) results were available within 4 hrs 30 min, irrespective of the S. aureus or CNS strains. Avoiding the isolation step on agar, Hemofast MRSA saves 24 to 48 hours, thus allowing earlier antistaphylococcal treatment.

Bacteriological Techniques↗
PubMed1997

[Tricentric study of the sensitivity of Pseudomonas aeruginosa serotyping to beta-lactams and aminoglycosides].

The aim of this study was to evaluate the susceptibility of 300 Pseudomonas aeruginosa strains to 6 beta-lactams and to 2 aminoglycosides and to compare this susceptibility according to the serotype, the sample nature, the unit activity and the geographic situation of the hospital. The susceptibility level was ascertained using the disk method. Serotyping of the strains was also performed. Susceptibility level was 67% for ticarcillin, 82% for piperacillin-tazobactam combination, 85% for ceftazidim, 81% for cefepim, 74% for aztreonam, 83% for imipenem, 73% for tobramycin and 86% for amikacin. Non-serotypable strains represented 20.6%. The most common serotypes were O6 (19%) and O11 (13%). Discrepancies between cefepime and ceftazidime were found in 15 strains after MIC determination, 6 of them were O12 strains. It appears that strain susceptibility was function of the serotype distribution. Cefepime exhibited outstanding activity against P. aeruginosa, similar to ceftazidim activity.

Aminoglycosides↗
PubMed1996

[In vitro antibacterial activity of a new fluoroquinolone, sparfloxacin, against nosocomial bacteria, and concordance curve].

Minimal inhibitory concentrations (MICs) of sparfloxacin (SFX) were determined by agar dilution for 3,164 bacterial strains isolated in 10 university hospitals; in addition, antibiograms by agar diffusion were performed with 5 micrograms disks. Activity of SFX against nalidixic acid (NAL) susceptible (S) Enterobacteriaceae was close to that of other fluoroquinolones (FQ) (MIC 50 and 90: 0.06-0.5 microgram/ml); like for other FQ, this activity was reduced against NAL intermediate and resistant (R) Enterobacteriaceae (2-16). MICs of SFX against P. aeruginosa were between 0.12 and 16 (1-32). SFX had also a good activity against NAL-S A. baumannii (CMI < or = 0.25) but this activity is reduced against NAL-R Acinetobacter (16). SFX was highly active against Haemophilus (0.016-0.06) gonococci (0.008), meningococci (0.008) and B. catarrhalis (0.008-0.03). SFX showed activity superior to the currently available FQ against methicillin susceptible staphylococci (0.06); the resistant strains [8] are usually methicillin resistant. SFX is more effective against enterococci (0.5), streptococci (0.25-0.5) and particularly pneumococci (0.25-0.5) including penicillin-resistant strains. The coefficient correlation of the regression curve is 0.876; for MIC breakpoints of 1 and 2 micrograms/ml, zone diameter breakpoints should be 20 and 16 mm.

Anti-Infective Agents↗
PubMed1993

[Mobile species of the genus Aeromonas: difficulties of identification and pathogenicity].

Sixty-two Aeromonas strains (39 of clinical and 23 of environmental origin) were identified. The suicide phenomenon and autoagglutination were studied. Identification is based on esculin hydrolysis; fermentation of arabinose salicin, sucrose and mannitol; gas production from glucose, indole and beta hemolysis; Voges-Proskauer and decarboxylation reactions; and finally resistance to cephalothin (30 micrograms) and colistin (4 micrograms/ml). Thirty-four per cent of A hydrophila, 33% A caviae, 28% A veronii subspecies sobria, 3% A jandaei, 2% A veronii subspecies veronii were accurately identified. Also, several new species were identified such as A trota, A enteropelogenes, A schubertii, A ichthiosmia, according to the more recently proposed taxa. This identification scheme could enhance our knowledge concerning virulence factors, pathogenicity and environmental distribution.

Aeromonas↗
PubMed1990

Gram-negative bacteria sepsis in the rat and tissue lipolytic activity on LCT and MCT/LCT-based commercial parenteral emulsions.

The aim of this study was to evaluate the effect of a gram-negative bacteria sepsis on the activity of the enzymes lipoprotein lipase (LPL) and hepatic lipase (HL), involved in the clearance of circulating triacylglycerol-rich fat particles. Fasting rats were intravenously injected with NaCl9 g.l-1, live or heat-killed Pseudomonas aeruginosa bacteria. After 18 h the animals were killed. When compared to controls, the 2 treated groups showed an increase in body temperature, cholesterolemia, triglyceridemia and a decrease in ketonemia, proteinemia, albuminemia and in the in vitro activity of diaphragm, heart and adipose tissue LPL and of HL. The decrease in the enzyme activities occurred independent of the type of emulsion used as in vitro substrate, whether it was based on long-chain triglycerides or on medium- and long-chain triglycerides, but in any case the activity was lower with the first than with the second type of fat emulsion.

Animals↗
PubMed1989

[Evaluation of a new semi-automatic method of identifying enterobacteriaceae, M.I.S.-Enterobacteriaceae].

M.I.S.-Enterobacteriaceae is a new kit for identifying Enterobacteriaceae using a microplate consisting of 21 biochemical characters with automated reading and interpretation. The validity of this method was studied by the identification of 350 strains of enterobacteria belonging to 44 species and comparison with the classical method of identification in test-tubes. Results showed a diagnosis accuracy of 96 p. cent at the species level and 97.7 p. cent at the genus level. Diagnosis accuracy reached 100 p. cent for those bacterial species isolated routinely: Proteus, Providencia, Morganella, Klebsiella, Enterobacter. Accuracy was 97 p. cent for E. coli, 95 p. cent for Serratia marcescens and 94 p. cent for C. freundii. For several less frequently isolated species such as Salmonella, Hafnia, Shigella and Yersinia, diagnosis accuracy was 100 p. cent. This identification system for enterobacteria can however also be used for identification of Aeromonas genus and for Pseudomonas maltophilia and Acinetobacter baumannii non fermenting Gram-negative bacilli with oxidase negative reaction.

Bacteriological Techniques↗
PubMed1988

Effects of chlorpromazine, berberine and verapamil on Escherichia coli heat-labile enterotoxin-induced intestinal hypersecretion in rabbit ileal loops.

The effects of chlorpromazine (CPZ), berberine and verapamil on intestinal hypersecretion in the rabbit ileal loop model by the heat-labile enterotoxin (LT) of Escherichia coli were studied in relation to their ability to inhibit the stimulation of intestinal adenylate cyclase (AC) by LT. CPZ 5 mg by the intraluminal (i.1.) route and 4 mg/kg by the intramuscular (i.m.) route significantly reduced LT-induced intestinal hypersecretion. Berberine (10 mg) exerted an inhibitory effect, but only after i.1. administration, whereas verapamil did not exert any significant inhibitory effect when administered either i.1. (2.5 mg) or i.m. (4 mg/kg). At concentrations of (0.17-1.34) X 10(-3) M CPZ, the anti-secretory effect of CPZ correlated with its inhibitory effect on rabbit LT-stimulated intestinal AC. Inhibition of cAMP synthesis was probably not involved in the mechanism of action of the two other substances. These results indicate that CPZ and phenothiazines in general are efficient drugs for reducing LT-induced intestinal hypersecretion and could represent a model for synthesis of new anti-secretory drugs with no tranquiliser side effects.

Adenylyl Cyclase Inhibitors↗
PubMed1985

[Isolation of Aeromonas hydrophila in diarrhea. Characterization of enterotoxinogenic strains and clinical relations].

Aeromonas hydrophila is isolated from diarrhoea specimens with increasing frequency. The interest in this organism at the present time is related to the fact that it can produce a number of toxins, in particular alpha and beta cytotoxic haemolysins, an enterotoxin and various enzymes. The authors determined the frequency of isolation of this organism and tested the haemolytic, cytotoxic and enterotoxic effects of culture filtrates in all of the stool specimens received in their laboratory over a period of 9 months. At the same time, the clinical context was defined in order to demonstrate a relation between the aptitude of the strains to produce toxins and the presence of diarrhoea. The frequency of isolation of A. hydrophila was 0.88 per cent, which corresponds to 67 strains. 38 strains presented a haemolytic and/or enterotoxic activity, i.e. 57 per cent of the strains isolated. In diarrhoeal stools, 67 per cent of the A. hydrophila isolated produced at least one of the toxins, while in the group of patients without diarrhoea, only 38 per cent of the strains isolated produced toxins. The results obtained reveal a statistically significant correlation between the production of cytotoxic haemolysin and the presence of diarrhoea. In contrast, there was no correlation between the production of enterotoxin and the presence of diarrhoea. Twenty of the 67 strains ware isolated from children under the age of 2 years. In 40 per cent of cases, no other aetiology could be found for the diarrhoea, apart from the isolation of A. hydrophila.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

A new purification procedure for Clostridium difficile enterotoxin.

Clostridium difficile produces two toxins, an enterotoxin and a cytotoxin. The enterotoxin was purified using fast methods (tangential flow filtration, fast protein liquid chromatography). The purified enterotoxin is composed of two subunits (A1 = 41,500, A2 = 16,000) and its pI is 3.5.

Chromatography, Liquid↗
PubMed1979

[Interest of stimultaneous determination of antistreptolysins and antideoxyribonuclease B in streptococcal infections (author's transl)].

The determination of antistreptolysin O (ASLO) and antideoxyribonuclease B (ADNase B) was carried out on a sample of 199 sera from normal subjects and on a sample of 4019 sera from patients admitted to the Strasbourg University Hospital Center. The sera of hospital origin were divided into two groups. The first group (n = 3889) consisted of sera taken at random, the second group (n = 130) corresponded to patients in whom we isolated a streptococcus of group A. The results obtained show that the distribution of ADNase B and ASLO of normal subjects follow a logarithmic distribution. The geometric averages of the titres DNAase B and ASLO of normal sera and of the first group of hospital origin are scarcely different, whereas the geometrical means of the titres of the second group of sera of hospital origin are quite different and two or three dilutions higher. We noted that the titres of DNAase B and ASLO were in agreement in 84% of cases in the whole group of hospital sera. Among the cases of discrepancy, the negative ASLO and the positive DNAase B corresponded mainly to streptococcal infections.

Antistreptolysin↗