Prevalence and characterization of extended-spectrum ß-lactamase-producing clinical Salmonella enterica isolates in Dakar, Senegal, from 1999 to 2009.

A total of 1623 clinical isolates of Salmonella belonging to 229 serotypes were received by the Senegalese Reference Center for Enterobacteria from January 1999 to December 2009. The most common serotypes were Enteritidis (19% of the isolates), Typhi (8%), Typhimurium (7%) and Kentucky (4%). A significant increase in the prevalence of resistance to amoxicillin (0.9% in 1999 to 11.1% in 2009) and nalidixic acid (0.9% in 1999 to 26.7% in 2009) was observed in non-typhoidal Salmonella serotypes. For critically important antibiotics, notably ciprofloxacin and extended-spectrum cephalosporins (ESCs), the rates of resistance were low: 0.3% and 0.5%, respectively. Seven ESC-resistant Salmonella strains and three additional ESC-resistant strains from Senegal (1990) and Mali (2007) were studied to identify the genetic basis of their antibiotic resistance. All ESC-resistant strains produced an extended-spectrum ß-lactamase (ESBL). These were CTX-M-15 (n = 6; 2000-2008), SHV-12 (n = 3; 2000-2001) and SHV-2 (n = 1; 1990). A large IncHI2 ST1 pK29-like plasmid was found in six strains (three producing SHV-12 and three CTX-M-15), whereas IncN and IncF plasmids were found in three strains and one strain, respectively. The association of plasmid-mediated quinolone resistance (PMQR) genes qnrB1 and aac(6')-Ib-cr was found in four ESBL-producing strains, leading to decreased susceptibility and even full resistance to ciprofloxacin (MIC range 0.75-2 mg/L) despite the absence of mutations in the quinolone resistance-determining region (QRDR) of gyrA, gyrB, parC and parE. This association of ESBL and multiple PMQR mechanisms within the same strains is therefore a serious concern as it hampers the use of both ESCs and fluoroquinolones for severe Salmonella infections.

Salmonella enterica serotype Gambia with CTX-M-3 and armA resistance markers: nosocomial infections with a fatal outcome.

We report two cases of bacteremia caused by the Salmonella enterica serotype Gambia in our children's hospital, with one fatal outcome. The isolates showed indistinguishable genotypes and infrequent resistance markers: CTX-M-3 extended-spectrum ß-lactamase and armA methyltransferase. This is the first report of S. Gambia exhibiting CTX-M-3 and armA markers involved in serious infections.

[Evaluation of the performances of the iQ(®)200 ELITE automated urine microscopy analyser and comparison with manual microscopy method]. / Évaluation des performances de l'automate de cytologie urinaire Iris iQ(®)200 ELITE et comparaison avec la méthode manuelle microscopique.

Microscopy urinalysis is one of the last manual analyses in laboratories and it is difficult to control. The automation of this analysis permits our laboratory to standardise this test. We performed an evaluation of the iQ(®)200 ELITE's performances and compare the data to the manual microscopy method which is considered as "the gold standard". The repeatability achieved at different levels of leukocytes and erythrocytes showed CVs below 10% for pathological values. Inter-run repeatability is 5,57% and carry-over is negligible if we take into consideration the linearity of the formed particles. Compared to the manual method, sensitivity (Se) of the analyser for leukocytes and erythrocytes are respectively 94.85 and 100%, the negative predictive value (NPV) are 92.91 and 100%, respectively. The weaknesses of the specificity (Sp) and positive predictive value (PPV) of erythrocytes (24.22 and 41.92%) are due to the lack of sensibility of the manual method. Also, the weak PPV of yeasts, casts and crystals are due to the better detection of those particles with the iQ(®)200's image recognition system than with manual method. NPV for all the urine formed particles are excellent, they are between 98 and 100%. The iQ(®)200 ELITE permits us to standardise and control this test for a future accreditation of the laboratory. We also significantly increase the turn around time.