Clinical Trial: Qnr Genes in Enterobacteriaceae
Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: Prevalence, Characterization and Risk Factors of Acquiring Qnr Genes in Extended Spectrum Beta-lactamase Producing Enterobacteriaceae Isolated in East Inter-region.
Brief Summary:
Enterobacteriaceae are bacteria of the gastrointestinal tract which are also the most frequently involved in bacterial infections, especially urinary tract infections. Because of their presence in the gut, these bacteria are the most exposed to antibiotic treatment administered to patients.
Therefore, many antibiotic resistance mechanisms are observed in some of them. Quinolone antibiotics are often used because of their distribution in the body, of the great number of bacterial species that are sensitive to these antibiotics and the possibility to give oral treatments.
For a long time no transferable resistance gene to quinolones from one bacterium to another had been observed. This phenomenon has been demonstrated in 1998 in a bacterium of the Klebsiella pneumoniae species carrying a qnrA gene which encodes a protein that protects the target of the antibiotic in the bacteria. Since several genes have been observed. These genes reduce the sensitivity of the bacteria without ever reach detectable resistance levels on the tests commonly used in the laboratory. However, these genes are often found among enterobacteria in combination with other mechanisms of resistance to other classes of antibiotics including beta-lactam antibiotics that are widely used antibiotics.
Moreover, it is considered that quinolone administration to bacteria carrying these qnr genes could promote the emergence of mutants resistant to quinolones to a more high-level. That furthers multiresistance emergence when the bacteria is already resistant to beta-lactam antibiotics.
The aim of this study performed between April 2008 and March 2009 was to collect strains resistant to beta-lactams because of the production of enzymes, called extended-spectrum beta-
Detailed Summary: The multidrug resistance in Enterobacteriaceae is a recurring concern for the treatment of patients. Given their epidemic character, the bacteria that produce extended spectrum beta-lactamase (ESBLs) are subject to extensive and costly preventive measures. Gene location of the first described ESBL were plasmids which could transfer from one species to another often associated with resistance to aminoglycoside. Quinolone resistance was not transferable. In 1998, was discovered a Klebsiella pneumoniae carrying a qnr A plasmid gene encoding a protein protecting girases and topoisomerase IV against quinolones. Yet the levels of ciprofloxacin MIC achieved by strains harboring this gene without any other quinolones resistance mechanism associated, remain low. However, the ciprofloxacin MICs for Escherichia coli lacking any other quinolone resistance mechanism can go from 0.003 mg / L to 0.25 mg / L, depending on the type of qnr. Currently, three types of qnr genes have been described, encoding proteins having several variants (qnrA (n = 6), qnrB (n = 10) and qnrS (n = 2). The qnrA and qnrB genes are carried by plasmids of 54-180 kb. Gene environment on plasmid DNA is that of class 1 integron or Type sul1 called. However the sequenced plasmids carrying qnrS do not have integron-like structures. These genes are more common in the Enterobacteriaceae strains producing ESBL strains than in the others. The low prevalences observed up to date, are increasing in some studies. We have observed qnr in 9 of 138 (6.5%) strains isolated in Champagne-Ardenne in 2004, including 4 of 10 strains of Enterobacter cloacae. Furthermore it has been shown in vitro that the presence of qnrA gene facilitated mutant selection for high-level quinolone resistance. Therefore, given the increasing trend in the prevalence of this gene reported by some authors, it is necessary to establish a monitoring and identify factors favoring the emergence of these strains. The purpose of the study is to observe t
Sponsor: CHU de Reims
Current Primary Outcome: number of ESBL-producing strains [ Time Frame: 22 months ]
Original Primary Outcome: Same as current
Current Secondary Outcome:
Original Secondary Outcome:
Information By: CHU de Reims
Dates:
Date Received: July 13, 2016
Date Started: January 2009
Date Completion:
Last Updated: July 26, 2016
Last Verified: July 2016
