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Biomedical subjects

C S Boye

Publications and source records attributed to C S Boye.

At least 19 recordsLinked to original sources

Class 2 integron-associated antibiotic resistance in Shigella sonnei isolates in Dakar, Senegal.

Forty-three Shigella sonnei isolates from adult patients with diarrhoea in Dakar were analysed for the presence of integrons. Isolates were resistant to sulphamethoxazole, trimethoprim, tetracycline, streptomycin and spectinomycin. A high prevalence of class 2 integrons (93%) was found. These integrons showed three distinct structures: a class 2 integron, part of the Tn7 family and its derivatives, carrying four cassettes in the order dfrA1-sat-aadA1-orfX; a truncated class 2 integron, without orfX; and a third type ca. 4 kb in size. These class 2 integrons probably play a role in the spread of multiresistance in S. sonnei isolates. To our knowledge, this is the first description of class 2 integrons in S. sonnei isolated in sub-Saharan Africa.

Adult↗

[A new case of rhinoscleroma with skin extension].

Scleroma is a chronic and specific granulomatous disease of bacterial origin. Klebsialla rhinoscleromatis, a gram-negative bacillus. The majority of cases affect the upper airways, particularly the nose, thus justifying the term of rhinoscleroma. Extension to the palate, the upper lip and the skin is possible. A new case of rhinoscleroma with skin extension is reported. To us, this is the second case in Senegal (Casamance). Epidemiological, clinical, bacteriological and histological aspects of the disease are reviewed. Under suitable antibiotic, evolution is currently favorable.

Adult↗

[Gastroduodenal peptic ulcer: descriptive study].

Our goals were to describe the epidemiological, clinical and endoscopic aspects of gastrointestinal ulcer and to determine the frequency of H. pylori, we included 140 gastrointestinal peptic ulcers from January 1999 to June 2000. Diagnosis of ulcerous disease delt with the presence of an ulcer discovered during a high digestive endoscopy. Gastro-duodenal ulcers bleeding or with stenosis have been excluded as well as patients who were under anticoagulant treatment or antibiotics or under pump of protons inhibitors during the previous month. Data were collected from a unique questionnaire specifying the sociodemographic characteristic, the history of the ulcerous disease, the antecedents, the style of life, and the endoscopic findings. Five biopsies were done using sterile grips and a fast urease test and the direct exam of the smear. The prevalence of gastro-duodenal ulcers in our population of survey was 6.2%. One hundred twenty eight duodenal ulcers (91.4%), and 12 gastric ulcers (8.6%) were found. The average of age was of 37.1 years +/- 15.3. The sex ratio was 2.9. The gastro-duodenal disease had begun for more than 5 years at 40.8%. No difference in the characters of the pain and signs has been found between duodenal and gastric localization of the ulcer. Hp was associated in 91.4% (91.4% when duodenal ulcers, 88.9% when gastric ulcers and all gastric and duodenal ulcers). We conclude that gastrointestinal ulcers occupies an important place in our gastroenterological practice and the infection rate with H. pylori infection is so high during gastro-duodenal ulcers in our country that the eradication of Hp could be proposed in any case of gastro-duodenal ulcer diagnosed by endoscopy.

Adult↗

[Acquired bacteraemias at the intensive care unit].

Acquired bacteraemias in intensive care unit (ICU) have some serious consequences in terms of morbidity, mortality and costs. The emergence of multiresistant germs in ICUs, and the therapeutic difficulties that ensue, participate in the aggravation of the prognosis of these infections. The aim of this work was to study the epidemiological aspects of acquired bacteraemias in ICU and the responsible germs sensitivity, to determine strategies of adequate antimicrobial treatment. During the period of study, 31 positive blood cultures collected from 19 patients were considered to be true bacteraemias, giving an incidence rate of 6.3 for 100 admissions. The mean age of our patients was 27.7 years old. There were 16 men and 3 women. Traumatology was the underlying pathology in 52.63% of cases. The origin of the infection was unknown in 84.2%. Flavobacterium spp was the most frequent germ (42%), followed by Pseudomonas aeruginosa (26.2%), and Staphylococcus negative coagulase (10.6%). Only one anaerobic germ was isolated. Flavobacterium spp and Pseudomonas aeruginosa were in general sensitive to most antibiotics used with the exception of aminosides. Staphylococci negative coagulase were methi - resistant. The sensitivity of the anaerobic germ was not tested. The antimicrobial treatment was adapted in 84.2% of cases; the association ciprofloxacine-cefotaxime could be a good alternative in serious infections to Gram negative bacteria. The global death rate among our patients was 42%. The death was directly related to bactereamia in only 15.3% of cases. The existing committee for nosocomial infections control should be more effective in our hospital. The role of this committee is to carry out microbiological surveillance, to recommand and make sure of the application of preventive measures against nosocomial infections, to promote the accessibility of antibiotics such as imipeneme, aztreonam, ceftazidime, vancomycine...., and to propose an appropriate antimicrobial treatment strategy; these measures could reduce notably the morbidity and mortality related to nosocomial infections in general and bactereamias in particular.

Adolescent↗

[Neonatal bacterial infections at the CUH of Dakar].

OBJECTIVES: It's a retrospective study in order to determine the epidemiology of neonatal bacterial infection and to evaluate the efficiency of the antibiotic protocol in University Teaching Hospital in Dakar. MATERIAL AND METHODES: From January 1st 1997 to December 31st 1998 we have registered 7461 live births, samples of blood are taken from 2312 new-born baby and they received antibiotherapy (beta-lactamine + gentamycin) at the first day based on infections risk evaluated by anamnestic criterias. The treatment is seven to one days long, the antibiotic was adapted according to the antibiogram result. RESULTS: The neonatal infection diagnosis is confirmed in 246 cases, about 33 per 1000 live births or 10.6% of newborn babies having on antibiotherapy. Most current risk factors are premature rupture of membranes (85%) and neonatal suffering (87.8%). Isolated gerras are: Klebsiella pneumoniae (61.5%), Enterobacteria (11.5 Staphylococcus (8.7%), colibacille (6%), Streptococcus (5.5%), Enterococcus (4.1%) and Pseudomonas (2.7%). Most of these germs are resistant to antibiotics currently used in first intention (ampicillin, cefotaxim, gentamycin), in particularly 95% of Klebsiella. Most efficient antibiotics are amikacin, colistin, ceftriaxon and ciprofloxacine. Deaths occurs in 48 cases with 36 in early neonatal period, 79% of mortality rate related to infection by Klebsiella. CONCLUSION: First intention antibiotherapy must be always adapted to the bacterial ecology evolution and must be more selective by using major infections risk factors. We promote early infection diagnosis by using biologic markers which reference is represented by C Reactive Protein.

Anti-Bacterial Agents↗

Two-year surveillance of antibiotic resistance in Streptococcus pneumoniae in four African cities.

Worldwide spread of antibiotic resistance in Streptococcus pneumoniae is a major problem. However, data from West and North African countries are scarce. To study the level of resistance and compare the situations in different cities, a prospective study was conducted in Abidjan (Ivory Coast), Casablanca (Morocco), Dakar (Senegal), and Tunis (Tunisia), from 1996 to 1997. The resistances to eight antibiotics of 375 isolates were studied by E test, and the results were interpreted using the breakpoints recommended by the National Committee for Clinical Laboratory Standards. Overall, 30.4% of the isolates were nonsusceptible to penicillin G (25.6% were intermediate and 4.8% were resistant). Amoxicillin (96.3% were susceptible) and parenteral third-generation cephalosporins (92.7%) were highly active. Resistance to chloramphenicol was detected in 8.6% of the isolates. High levels of resistance were noted for erythromycin (28%), tetracycline (38.3%), and cotrimoxazole (36.4%). Resistance to rifampin was rare (2.1%). There were significant differences in resistance rates between individual countries. Multiple resistance was more frequent in penicillin-nonsusceptible isolates than in penicillin-susceptible isolates. Recommendations for treatment could be generated from these results in each participating country.

Africa↗

[Feasability of a heart valve bank in Dakar. (Preliminary study of 8 human hearts)].

Authors record a preliminary study led so as to develope techniques of preparation of the cardiac homograft valves. Eight human hearts have been appropriated in the course of medico-legal autopsy. Under sterile hodd, the heart was dissected, aortic and pulmonary valves as well as a mitral valve fragment were collected for a total of 24 valvular levies. After sterlization in an antibiotic solution, valves were preserved at 4 degrees C for the mitral fragment specimen of fresh allograft and to - 196 degrees C in Nitrogen liquidates for the pulmonary and aortic valves. The control of graft quality had consisted in tests of competence during the dissection, to the evaluation of the histological study as well as tests of sterility. Cellular cultures had shown a fibroblast proliferation in 3 cases. It concerned an indeed reliable method but difficult and little sensitivity. Histological tests had shown two types of injurie: the myxoid degeneration (7 times on 8 valves) cryopreserved and a coagulative necrosis whose distribution was identical forthe two modes of conservation. Antibiotic's solution seemed to induce these injuries as do heart ischemia, and the traumatism lihleed to the great cold. The tests of sterility had shown a rate of contamination to 25 % essentially by Pseudomonas. In view of the installation of a behle of allograft bank of quality, we'll need to improve conditions of leavy, to use a freezer adaptation for progressive cryocongelation and the choice of simple method to evaluate valvular viabilty.

Adolescent↗

[Nasal carriage of Staphylococcus aureus at a hemodialysis unit in Dakar].

Infectious diseases are the most common complications of the hemodialysis unit patients. Staphylococcus aureus (SA) is the main cause and is supposed to be lodged in the nostrils. The purpose of this study is to assess the importance of the SA presence in the patients and the medical staff nostrils in a senegaleese hemodialysis unit. In this regard, we performed a six-month prospective study on 12 patients on going hemodialysis (11 males and 1 female) and 7 medical agents (4 nurses, 2 physicians, and 1 nurse assistant). On patients we reported the initial nephropathy, the problems of vascular access, the infectious episodes prior to the study, and the duration of dialysis. Three sample series of nostril swabbing were carried out on patients and medical staff at a rate of one series every other month. Blood culture was systematically carried out on patients, with body temperature higher than 38 degrees C, every two months and. Sensibility to several antibiotics was tested for each stain. We found six cases of clinical nephroangiosclerosis, one Wegener granuloma and five unknown causes. All patients had Brescia Cimino arteriovenous fistula vascular and the mean time underdialysis was 36 months (from 7 to 55). Bacteriologically, 124 nostril specimens were performed, 80 on patients, 44 on medical staff. SA was isolated in 64 specimens (52 %) on patients and 34 specimens (24.4 %) on staff. Strains from forty five patients (70.32 %) were sensitive to methicillin versus 23 stains from staff ( 67.6 %). The difference was not statistically significant. Sensibility profil for other antibiotics was the same for patients and staff. All blood culture were negative. Despite nostril carriage noted on patients and staff, there were no infections during this period. However, the presence of permanent infection sites make it mandatory to be on the alert in order to control some of the behavioral changes of the germs, and to put into place an adequate prevention system.

Adult↗

Rapid susceptibility testing of Mycobacterium tuberculosis by the Mycobacteria Growth Indicator Tube (MGIT AST SIRE).

OBJECTIVE: To evaluate the reliability of the Mycobacteria Growth Indicator Tube (MGIT AST) for susceptibility testing of Mycobacterium tuberculosis. METHODS: Seventy strains of M. tuberculosis were tested for susceptibility to streptomycin, isoniazid, rifampicin and ethambutol by comparing MGIT AST results to those obtained by the method of proportion (MOP) on Lowenstein-Jensen (LJ) and Middlebrook 7H10 media. The 7H10 MOP was considered the method of reference. RESULTS: The turnaround time for MGIT AST was 6.2 days (5-10 days) and for MOP it was 18-21 days. With rifampicin, MGIT AST agreed for all isolates with both MOP. For streptomycin, MGIT AST and 7H10 MOP agreed for 64 isolates (91.4%); 61 were susceptible and three resistant. LJ MOP and 7H10 MOP agreed for 64 isolates (92.2%); 62 were susceptible and three resistant. With isoniazid, both MOP agreed for all isolates, while MGIT AST and 7H10 MOP had two discrepancies. For ethambutol, MGIT AST and 7H10 MOP were concordant for 66 isolates; 65 were susceptible and one resistant. Both MOP were concordant for 67 isolates; 66 were susceptible and one resistant. CONCLUSIONS: Based on these results, MGIT AST is a time-saving method and can be used as an alternative to the BACTEC System. MGIT AST is reliable as far as rifampicin and isoniazid are concerned; however, additional studies are needed for streptomycin and ethambutol.

Drug Resistance, Microbial↗

[Improvement of tuberculosis diagnosis by the Mycobacteria Growth Indicator Tube (MGIT) in a developing country laboratory].

In order to improve tuberculosis diagnosis in a developing country (Senegal), we evaluated a new liquid-based medium and nonradioactive system, Mycobacteria Growth Indicator Tube (MGIT), with individual clinical specimens collected in Dakar. The main purpose was to compare the time to detection and the rate of recovery of Mycobacterium tuberculosis complex and to determine its importance with respect to Lowenstein-Jensen (LJ), a liquid-based-medium for isolation of M. tuberculosis complex. 531 specimens were processed with Mycoprep kit containing NaOH-N-acetyl L-cystein and inoculated on both LJ and MGIT and incubated at 37 degrees C for 60 days. For each medium, the recovery rate and the time to detection were recorded. Among the 531 specimens, of which 121 smears were positive, 32.5% (173/531) grew the M. tuberculosis complex. Of these, 103 were smear positive (S+) and 70 smear negative (S-). LJ recovered 54.9% (95/173) and MGIT recovered 91.9% (159/173). Disagreements were observed with 92 isolates, LJ failed to recover 78 while MGIT failed to recover 14. The overall mean time to detection was 20.1 days for LJ and 10.5 days for MGIT. MGIT has shown a better sensitivity in isolation with significant reduction in reporting culture for M. tuberculosis complex. As a simple and a nonradiometric system, it could be used in conjunction with egg-based media in developing countries laboratories.

Bacteriological Techniques↗

[Micromethod for identification of enterobacteria].

The aim of this study was to set accurate and reliable methods in the identification of Enterobacteriaceae. In Micro CSB Entero each of a strip with 20 cupules containing dehydrated substrates for biochemical identification of bacterial species. Strips were inoculated with 100 microliters per cupule and incubated. After 18 hours, reagents were added. Baye's theorem was used to validate tests. Reactions from Micro CSB were cleared and easily read. 102 strains of Enterobacteriaceae were identified by MicroCSB--89.3% were correctly identified. 0.9% were identified with other tests 9.8% were incorrectly identified MicroCSB gives many advantages: This method save time, space and is less expensive than the other methods and it gives security for identifying species belonging to the different genera.

Bacterial Typing Techniques↗

[Micromethod for the identification of streptococcal, enterococcal and staphylococcal species].

The aim of this study was to set accurate and reliable methods in the identification of streptococcal, enterococcal and staphylococcal species. Micro CSB Strep and Staph system consists each of a strip with cupules containing dehydrated substrates for biochemical identification of bacterial species. Baye's theorem was used to validate tests. Reactions from micromethods were clear and easily read. Identification of 229 strains of streptococci and enterococci was correct for most species with 98.7% species with 99.3% sensitivity. 41 strains of staphylococci were also correctly identified with 85.2% of specificity and 97.68% of sensitivity.

Bacterial Typing Techniques↗

Phenotypic and genotypic characterization of Vibrio cholerae isolates from a recent cholera outbreak in Senegal: comparison with isolates from Guinea-Bissau.

A total of 127 strains of Vibrio cholerae (117 V. cholerae O1 and 10 nonagglutinating strains) isolated from a recent cholera outbreak in Senegal and four strains isolated in Guinea-Bissau (during the survey of a cholera epidemic that occurred 10 months before the Senegalese one) were analyzed. Strains were characterized by conventional methods (biochemical and serologic identification, susceptibility to antimicrobial agents), polymerase chain reaction for genes encoding cholera toxin (CtxA), zonula occludens toxin (Zot), and accessory cholera enterotoxin (Ace), and by ribotyping. Conventional methods showed that all strains of V. cholerae O1 belonged to serotype Ogawa, biotype El Tor and were resistant to the vibriostatic agent O129 (2,4-diamino 6,7-diisopropylpteridine phosphate), cotrimoxazole, and chloramphenicol; all strains were sensitive to tetracycline, a drug that has been extensively used in cholera therapy. Most of these V. cholerae O1 (112 strains from Senegal and four strains from Guinea-Bissau) had an intact core region (virulence cassette) and amplified a 564-basepair (bp) fragment of ctxA, a 1083-bp fragment of zot, and a 314-bp fragment of ace. Ribotyping of V. cholerae O1 strains after Bgl I restriction of total DNA revealed that ribotype B5a, which is the predominant ribotype of this seventh pandemic of cholera, was not isolated. Instead, a new ribotype was identified and designated B27 in our data bank. Since O1 isolates from Guinea-Bissau and Senegal have the same biotype, serotype, and ribotype and as the Guinea-Bissau outbreak that preceded the one in Senegal, this emerging ribotype probably came from Guinea-Bissau. Nonagglutinating strains exhibited no resistance to the O129 agent and to the tested antibiotics, they were all negative for virulence cassette, except for one strain with the ctxA and zot genes isolated from a patient with diarrhea, and there was a great variability of ribotypes among these strains. There was no difference between environmental O1 strains isolated from water and strains isolated from patients with cholera, suggesting that fecally contaminated water is an important reservoir for infection.

Bacterial Typing Techniques↗

[Well water pollution in the Khombole district: research on the contamination by organochlorine pesticide residues and organic substances (feces)].

The study realized in the district of Khombole (SENEGAL) has permit to estimate the contamination levels of wells waters used by the populations. The research and the dosage of the organichlorine pesticide residues, nitrites and nitrates and microbiologic analysis have been done on 19 wells chosen after a drawning of lots. The organochlorine pesticide residues which have been found prove that the wells are permanently exposed to these chemical substances which don't constitute nevertheless a major risk for the populations health. The results of our research proved also that there is a real risk of intoxication with the nitrogen oxides. In effects more than 50% of the wells have revealed nitrates contents up to the indicative value (25 mg/l). As for the nitrates, with a few exceptions (5/18), the contents are superior to the authorized norm (0.1 mg/l). By another way the bacteriologic analysis has revealed in the one hand a DBT (Total Bacterian Count) up to 10,000 germs/l for all the wells, and in the other hand the presence of Escherichia coli, Enterococcus faecalis that confirm a faecal contamination.

Colony Count, Microbial↗

[Methicillin-resistant Staphylococcus aureus in Dakar].

This study was carried out at the Fann University Hospital Center in Dakar, Senegal between 1994 and 1996. The purpose was to assess the prevalence of methicillin-resistant Staphylococcus aureus and to propose alternative treatments. A total of 149 stains of Staphylococcus aureus were isolated from a variety of clinical specimens. Sensitivity to various antibiotics was tested by the disc diffusion technique (anti-biogram). Resistance to methicillin was evaluated by the oxacillin disc diffusion technique on Mueller-Hinton agar containing 5% NaCl. The prevalence of methicillin resistance was 66.4%. All strains of Staphylococcus aureus were sensitive to vancomycin. Other highly effective antibiotics included fucidic acid (94%), aminoglycosides (91%), cotrimoxazol (89.6%), and norfloxacin (84.5%). Most strains (70.6%) presented a wide profile against macrolides and related groups. The LSa phenotype (resistance to lincosamines and streptogramines) was the predominant resistant phenotype. The results of this study indicate that the prevalence of methicillin-resistant Staphylococcus aureus is increasing in Senegal. Since these strains respond well to chloramphenicol and cotrimoxazole, clinicians are advised to use these drugs as an alternative first-line treatment.

Methicillin Resistance↗

Isolation of a new variant of Vibrio cholerae O1: V. cholerae O1 ribotype B27 toxinogenotype TB31 during the last cholera epidemic in Senegal.

A total of 205 Vibrio cholerae O1 isolates from recent cholera epidemic in Senegal were analyzed by conventional methods, polymerase chain reaction (PCR) for genes encoding cholera toxin (ctx A), zonula occludens toxin (zot) and accessory cholera enterotoxin (ace), ribotyping and toxinogenotyping. Ribotyping after Bg1 I digestion of total DNA revealed that ribotype B5a, the predominant ribotype of the seventh pandemic in Africa and Asia, was not isolated. A new ribotype designated B27 in our database is predominant and was associated with a new toxinogenotype designated TB31.

Cholera↗

[Sensitivity profiles of enterobacteria isolated at th Fann University Hospital Center, Dakar].

This study concerns 180 strains of Enterobacteria isolated at Fann University Teaching Hospital (Dakar, Senegal). The susceptibility to antibiotics was tested by disc diffusion test (antibiogram) and by dilution method determining the minimum inhibitory concentration (MIC). All of the species present more resistant profile to beta-lactams (> 55%); however ceftriaxon and aztreonam present the lower MIC 50 (< 0.06 microgram/ml). Fluoroquinolon inhibits more than 90% of the strains of E. Coli and Proteus. Chloramphenicol is active on Salmonella, but ceftriaxon, aztreonam and the fluoroquinolon present good alternatives. Cotrimoxazole is active only on 54% of Shigella strains.

Anti-Bacterial Agents↗

[Phenotypic differences of nosocomial bacterial strains isolated in the obstetric-gynecology service of the University Hospital Center of Dakar].

A study on nosocomial infections was conducted in the Laboratory of Bacteriology-Virology of Aristide Le Dantec's Hospital, in collaboration with the Gynecology Obstetrics clinic located both in the same Dakar's hospital, during May 1995. The aim of the study was to define the phenotypical characteristics of various bacterial strains isolated from the atmosphere health care staff's hands, medical equipment (material, antiseptics) and patients (hospitalized pregnant and newborns in day Nursery). A total of 133 strains were collected and the most frequent isolates were Staphylococcus aureus (27 strains) and Klebsiella pneumoniae (10 strains) encountered mainly in the atmosphere. Otherwise, Escherichia coli (11 strains) and Enterococcus faecalis (11 strains) were more present in hospitalized patients. Results obtained after antimicrobial agents susceptibility (Antibiotics and Heavy metal salts) by Antibiogramm and Minimal inhibitory concentrations (MIC) and also data from biotyping of Klebsiella strains have allowed us to say there's a probable contamination of hospitalized patients by the bacteria from the atmosphere but manuportage too.

Bacterial Infections↗