Lucien Brasme

Rapid detection of qnr and qepA plasmid-mediated quinolone resistance genes using real-time PCR.

Plasmid-mediated quinolone resistance genes in clinical strains cannot be detected by phenotypic traits but require gene detection. We developed a multiplex real-time polymerase chain reaction (PCR) assay using high-resolution melting master mix with ResoLight dye to detect qnr genes and a simplex real-time PCR assay using SYBR Green I to detect qepA genes. Using qnr-positive and qepA1-positive control strains, the ResoLight method was able to rapidly identify qnrA, qnrB, qnrS, qnrC, and qnrD genes; the SYBR Green I method identified qepA genes. Among 118 extended spectrum beta-lactamase-producing Enterobacteriaceae isolates, the 2 new assays efficiently detected and identified qnr in 9 strains, but no qepA gene. To our knowledge, this is the first study describing the detection of all 5 qnr and qepA genes using real-time PCR. The 2 tests constitute a significant step forward for screening for plasmid quinolone resistance genes in clinical strains.

Leptospira exposure in the human environment in France: A survey in feral rodents and in fresh water.

This paper confirms the important role of rodents to be maintenance hosts of leptospires. Their role is related to renal carriage and shedding of leptospires into urine, thus contaminating fresh water. Serological and carriage of feral rodents trapped in France were determined by MAT and hap1PCR specific for pathogenic leptospires. In same areas, fresh water samples were analyzed by hap1PCR. The overall seroprevalence was 44% in 649 rodents and was similar regardless of the species. Seroprevalence for leptospirosis is about 20-53% according to species. hap1PCR (516 kidneys) showed that renal carriage was higher in brown rats (34.7%) and muskrats (15.8%) than in coypus (3.3%). hap1PCR demonstrates a significative difference (P-value > 10(-12)) for the renal carriage between the different species: muskrats and rats are more efficient maintenance hosts than coypu but all infect water. Moreover 5/38 water samples associated with human cases were hap1PCR positive and 1/113 in controlled waters.

Rapid Detection of aac(6′)-Ib-cr Quinolone Resistance Gene by Pyrosequencing

ABSTRACT Pyrosequencing was used to rapidly detect aac(6′)-Ib and aac(6′)-Ib-cr genes. This plasmid-mediated quinolone resistance determinant is increasing in extended-spectrum beta-lactamase-producing Enterobacteriaceae. This method is faster and more cost-effective than the methods previously described. Sequences obtained with this pyrosequencing method showed 100% concordance with conventional sequencing.

Rapid detection of quinolone resistance gene aac(6')-Ib-cr by pyrosequencing

ABSTRACT Pyrosequencing was used to rapidly detect aac(6′)-Ib and aac(6′)-Ib-cr genes. This plasmid-mediated quinolone resistance determinant is increasing in extended-spectrum beta-lactamase-producing Enterobacteriaceae. This method is faster and more cost-effective than the methods previously described. Sequences obtained with this pyrosequencing method showed 100% concordance with conventional sequencing.

Gastroscopy-associated transmission of extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa

An unusual multi-drug-resistant Pseudomonas aeruginosa (MDR-PA) was isolated in four patients whilst hospitalized in a French teaching hospital between May and August 2011. All four patients had undergone an oesophago-gastro-duodenoscopy with the same gastroscope over a five-month period. This endoscope was associated with a culture positive for the MDR-PA. Observations of endoscope reprocessing identified deviations from the agreed processes: insufficient initial cleaning, shortening of the immersion time and brushing time, insufficient channel flushing, and inadequate drying prior to storage. Since withdrawing the gastroscope and institution of strict adherence to the agreed processes, no other MDR-PA cases have been isolated.

Description of a 2,683-base-pair plasmid containing qnrD in two Providencia rettgeri isolates.

ABSTRACT qnr genes are plasmid-mediated quinolone resistance genes mainly harbored on large conjugative multiresistant plasmids. The qnrD gene was recently observed in Salmonella enterica on a small nonconjugative plasmid (p2007057). We describe two strains of Providencia rettgeri harboring qnrD on nonconjugative plasmids. The plasmids were 99% identical, with 2,683 bp and four open reading frames, including qnrD, but exhibited only 53% identity with the plasmid found in S. enterica.

Characterization of Extended-Spectrum Beta-Lactamase–Producing Salmonella enterica Serotype Brunei and Heidelberg at the Hussein Dey Hospital in Algiers (Algeria)

The purpose of this work was to study the genetic determinants responsible for extended-spectrum cephalosporin (ESC) resistance of Salmonella collected during the period of 1995-2008 at the Hussein Dey hospital in Algiers (Algeria). Fourteen ESC-resistant Salmonella isolates were tested towards 22 antimicrobial agents. Polymerase chain reaction (PCR) and sequencing were used to determine the underlying genetic determinants responsible for the extended-spectrum beta-lactamase (ESBL) phenotypes. Enterobacterial Repetitive Intergenic Consensus PCR was employed to type the isolates. All tested isolates were resistant to ticarcillin, ticarcillin-clavulanate, piperacillin, cefuroxime, aztreonam, ceftazidime, cefotaxime (except two isolates), cefepime, and cefpirome. PCR and DNA sequencing identified these ESBLs as TEM-48 (n=6), TEM-4 (n=3), CTX-M-15 (n=4), and one new TEM, designated TEM-188. Thus, continued surveillance for the presence of ESBL-producing (non-typhoidal) salmonellae in Algeria is essential.

Extended-spectrum β-lactamase characterisation and heavy metal resistance of Enterobacteriaceae strains isolated from hospital environmental surfaces

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Fluoroquinolone Resistance Mechanisms and population structure of Enterobacter cloacae non-susceptible to Ertapenem in North-Eastern France.

Fluoroquinolone (FQ) agents are a potential resort to treat infection due to Enterobacteriaceae producing extended spectrum β-lactamase and susceptible to FQ. In a context of increase of non-susceptibility to carbapenems among Enterobacteriaceae, we characterized FQ resistance mechanisms in 75 Enterobacter cloacae isolates non-susceptible to ertapenem in North-Eastern France in 2012 and describe the population structure by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). Among them, 14.7% (12/75) carried a carbapenemase-encoding gene. Except one isolate producing VIM-1, the carbapenemase-producing isolates carried the well-known IncL/M pOXA48a plasmid. Most of the isolates (59/75) harbored at least a FQ-R determinant. qnr genes were predominant (40%, 30/75). The MLST study revealed that E. cloacae isolates’ clonality was wide [24 different sequence types (STs)]. The more widespread STs were ST74, ST101, ST110, ST114, and ST133. Carbapenem MICs were higher for E. cloacae ST74 than for other E. cloacae isolates. Plasmid-mediated quinolone resistance determinants were more often observed in E. cloacae ST74 isolates. These findings showed that (i) pOXA-48a is spreading in North-Eastern France, (ii) qnr is preponderant in E. cloacae, (iii) E. cloacae comprised a large amount of lineages spreading in North-Eastern France, and (iv) FQ as an alternative to β-lactams to treat ertapenem non-susceptible Enterobacteriaceae are compromised.

Postoperative spondylodiskitis due to Stomatococcus mucilaginosus in an immunocompetent patient.

A case is reported of postoperative spondylodiskitis due to Stomatococcus mucilaginosus in an immunocompetent woman. The route of infection remains unknown. Intravenous treatment with cefotaxime and fosfomycin was given, followed by oral administration of rifampin and pristinamycin until resolution of infection. This report shows that this bacterium can cause severe infections in immunocompetent patients.