Fortuitous Detection of cmy-2 and dha-1 from ESBL-producing Escherichia coli in Senegal.

Cephalosporinases, which are naturally present in some enterobacterial species, can be mobilized by transposons, migrate to plasmids, and spread into other species such as Escherichia coli. The aim of this study was to characterize genes responsible for the production of extended-spectrum ß-lactamases (ESBL) in E. coli isolates from urinary origin isolated in two hospitals in Senegal. Thus, a fortuitous discovery of plasmidic cephalosporinase in two isolates was noted. One of the isolates produced dha-1 associated with ESBL CTX-M-14, the other produced cmy-2, ESBL CTXM-15, tem-1 penicillinase, and oxa-1. This confirms the circulation of multidrug-resistant bacteria producing plasmidic cephalosporinase in Senegal. However, a large study is needed to better understand the prevalence and the nature of the genes involved.

Antimicrobial Resistance in Outpatient Escherichia coli Urinary Isolates in Dakar; Senegal

Background: Data regarding the evolution of antimicrobial resistance are needed to suggest appropriate empirical treatment of urinary tract infections (UTI) in developing countries. To assess the antimicrobial susceptibility of Escherichia coli; the predominant pathogen in community-acquired UTI; a prospective multicenter study was carried out in Dakar; Senegal. Methodology: From February 2004 to October 2006; 1010 non-duplicate E. coli strains were collected from four centres. Antimicrobial susceptibility testing was performed using disk diffusion method according to the recommendations of the CA-SFM (2004). Results: Most of the isolates were resistant to amoxicillin (73.1); amoxicillin- clavulanic acid (67.5); cephalothin (55.8); and trimethoprim/sulfamethoxazole (68.1). Extended spectrum beta-lactamase was detected in 38 strains. The overall resistance rates to nalidixic acid; norfloxacin and ciprofloxacin were 23.9; 16.4and 15.5; respectively. Most of the strains were susceptible to gentamicin; nitrofurantoin and fosfomycin (respective susceptibility rates; 93.8; 89.9; and 99.3). During this period; a significant decrease in sensitivity was observed for cephalothin; fluoroquinolones and trimethoprim/sulfamethoxazole (p0.001). Conclusions: These data suggest that trimethoprim/sulfamethoxazole may no longer be used as empirical treatment for community- acquired UTI in Dakar. In order to preserve the activity of fluoroquinolones for future years; alternatives such as fosfomycin or nitrofurantoin should be considered

[Preliminary study of human Herpesvirus type 8 infection in pregnant women in Dakar (Senegal)]. / Etude préliminaire de l'infection à Herpesvirus humain type 8 chez les femmes enceintes à Dakar (Sénégal).

HHV8 was discovered in 1994 and few studies on this virus have been conducted in Africa. The virus is related to Kaposi sarcoma, an opportunistic affection occurring during HIV infection. No studies have been carried out on this subject in Senegal, a country known for its low KS prevalence even among people living with HIV/AIDS. Thus it will be interesting to explore this field. The aim of our study has been first, to demonstrate the presence of HHV8; second, to evaluate sero-prevalence of the infection in Senegal and third, to determine the specificities of HHV8 infection in our country. We performed our study on 407 pregnant women whose average age was 29.24 years, the majority of whom were Senegalese. HIV serology was done by dot blot for the screening and western blot for the confirmation. For the diagnosis of HHV8 infection, we used the indirect immunofluorescence kit of ABI. HIV infection was low among this study population; 0.5% and no HIV1 infection was mentioned. Among the 407 women, 58 or 14.3% were HHV8 positive and there was no HHV8/HIVco-infection. Regarding marital status, no significant difference was found between HHV8 positive and HHV8 negative among unmarried, monogamous or polygamous women. However, women having had 4 to 5 children were more likely to test positive for HHV8. The difference is significant and a relationship has been established with a p value of 0.02. Regarding pregnancy, HHV8 infection is more closely related to abortion: 17.2% of women who had aborted were HHV8 positive versus 4.9% seronegative. The odds ratio calculation shows a strong correlation with a p value of 0.01. No correlation was found between HHV8 infection of the mother and neonate mortality or Apgar score. However, a relationship did show up between HHV8 infection of the mother and low birth weight. 29.2% of seropositive women had had a child with a birth weight under 2600 g whereas only 16.3% of seronegative women had had babies with low birth weight. We determined that HHV8 is indeed present in Senegal. Further studies should focus on transmission routes as well as the molecular epidemiology of this virus and diseases related to HHV8 infection in Senegal.

High levels of tumor necrosis factor-alpha and interleukin-1beta in bacterial vaginosis may increase susceptibility to human immunodeficiency virus.

Bacterial vaginosis (BV) was identified recently as a cofactor that promotes sexual transmission of human immunodeficiency virus (HIV). This study was done to determine if interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha could be measured consistently in cervical secretions and if high levels of these cytokines were associated with BV. Secretions were obtained from 209 study subjects; most samples had detectable levels of TNF-alpha (84.2%) and IL-1beta (79.8%). BV was detected in 53 (27.0%) of 196 women. High cytokine levels were significantly associated with BV (adjusted odds ratio [AOR], 4.17; 95% confidence interval [CI], 1.69-10.30), oral contraceptive use (AOR, 2.78; 95% CI, 1.04-7.48), and high leukocyte counts on vaginal smear (AOR, 1.18; 95% CI, 1.03-1.36). Since these cytokines could up-regulate local HIV replication through activation of the long terminal repeat promoter region, the association of BV with high levels of IL-1beta or TNF-alpha may partly explain the mechanism by which this risk factor enhances HIV transmission.

[Improvement of tuberculosis diagnosis by the Mycobacteria Growth Indicator Tube (MGIT) in a developing country laboratory]. / Amélioration du diagnostic de la tuberculose par le Mycobacteria Growth Indicator tube (MGIT) dans un laboratoire de pays en développement.

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.

Identification of all HIV type 1 group M subtypes in Senegal, a country with low and stable seroprevalence.

A total of 343 HIV-1-positive samples obtained between June 1996 and March 1999 was genetically characterized in the envelope region by HMA and/or sequencing. The env subtype distribution was as follows: 290 (84.6%) A, 22 (6.5%) B, 16 (4.7%) C, 8 (2.5%) D, 1 (0.03%) E, 1 (0.03%) F1, 4 (1.2%) G, and 1 (0.03%) H. For 77 samples the p24 region from the gag gene was also sequenced, and for 9 (11.6%) the subtypes between env and gag were different. Phylogenetic tree analysis showed the predominance of AG-IBNG-like viruses among gag and env subtype A sequences. HMA is relatively simple and requires less sophisticated technical facilities compared with sequencing, and in Senegal 323 (94.2%) of the 343 samples could be identified by this technique. However, in the actual configuration of the assay, discrimination between the recombinant AG-IBNG-like recombinant viruses, which are predominant in Senegal, and the nonrecombinant subtype A viruses is not possible.

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.

[Antibiotic sensitivity of Salmonella strains isolated in a pediatric population in Dakar. Research of beta-lactamase and plasmids]. / Sensibilité aux antibiotiques des souches de Salmonella isolées en milieu pédiatrique dakarois. Recherche de bêta-lactamase et de plasmides.

114 strains of Salmonella were isolated from many samples in the Pediatric Hospital (Hôpital d'Enfants Albert Royer) of Dakar between January 1985 and December 1991. The sensibility to antibiotics were tested, and we studied the production of beta-lactamase and the presence of plasmids in the resistant strains. 27 serovars of Salmonella were identified and Salmonella typhi predominates with 45%. Only 28% of the strains were susceptible to all of the antibiotics, and 17% were found multiresistant; 8% of the strains produce beta-lactamase and plasmids were found in 6 multiresistant strains.

[Urinary bacteriology in the elderly in the tropical zone: results of 5 years of activities at the CHU of Fann in Dakar]. / Bactériologie des urines chez le sujet âgé en zone tropicale: bilan de cinq années d'activités au CHU de Fann à Dakar.

The authors report a retrospective account on 5 years (1987-1991) studied on 300 specimen of urine, coming from subjects aged 65 or more and having been submitted to bacteriologic examination in Dakar, Senegal (microscopic examination, counting, isolation, identification of bacteria, antibiotic tests). On the whole, 8150 samples of urine were recorded during the same period in the Laboratory of Bacteriology (CHU de Fann). The results obtained show a particular exposure of the old subjects to urinary tract infection (37%, against 23% in subjects aged less 65 years). The isolation of bacteria was not attached to sex. E. coli and Klebsiella sp. are the most frequently isolated in urine. The most efficacy antibiotics on these agents are the Cepholosporins, the Aminosids, Nitroxolin and Oxolonic Acid.

[Salmonellosis: evaluation of 606 strains isolated in Dakar]. / Salmonelloses: bilan de 606 souches isolées à Dakar.

From 1979 to 1982, 606 strains of Salmonella have been isolated in the Laboratories of the CHU of Dakar, Senegal. The endemics serotypes are S. typhi (73%), S. enteritidis (5% and S. typhimurium (5%). Among the epidemics serotypes of Salmonella, the more commonly isolated is S. ordonnez (10%). These four serotypes represented 93% of the strains of Salmonella. Seventy per cent of the strains had been isolated from patients aged under less than twenty years. The epidemic serotypes provide essentially from infant. Five antibiotics among the eighteen tested, have inhibited 100% of Salmonella. A multiresistance to more than five antibiotics have been observed for sixty four strains (11%). Some strains of S. typhi (4%) are resistant to the chloramphenicol and three of them were multiresistants; this may result from the transfer of plasmidic's resistance of multiresistant epidemics serotypes Salmonella circulating in Dakar. In Sénégal, periodics studies of the epidemiology of Salmonella are justified.

[Neonatal bacterial infections: a retrospective study over 8 years]. / Bactériologie des infections néonatales: une étude rétrospective sur 8 ans.

In a retrospective study, one thousand and ten miscellaneous samples coming from infected newborns and tested at the bacteriology laboratory of A. Royer Children's Hospital from 1983 to 1991 were reviewed. These samples included 471 blood cultures, 114 pus of various origins, 410 cerebrospinal fluids and 15 urines. One bacterium or bacterial soluble antigens was detected in 294 samples (29.2%). Positivity percentage was 29.2% for septicemias, 68% for suppurations, 17.8% for meningitidis and 33.3% for urinary tract infections. There major species were identified: S. aureus (25.8%), Klebsiella spp (19.7%) and E. Coli (14.6%). Altogether, we isolated 156 enterobacteria (53%), 14 Gram negative bacilli (4.7%) and 124 cocci (42.1%) among which 19 streptococci (A, B, C) and 25 pneumococci. The most efficient antibiotics against all strains were AKN, CTX, CRO and GEN.