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Rubén Monárrez, Yin Wang, Yingmei Fu, Chun-Hsing Liao, Ryo Okumura, Molly R Braun, George A Jacoby, David C Hooper
Expression of the quinolone resistance gene qnrS1 is increased by quinolones, but, unlike induction of some other qnr genes, the bacterial SOS system is not involved and no lexA box is found upstream. Nonetheless, at least 205-bp of upstream sequence is required for induction to take place. An upstream sequence bound to beads trapped potential binding proteins from cell extracts that were identified by mass spectrometry as Dps, Fis, Ihf, Lrp, CysB, and YjhU. To further elucidate their role a reporter plasmid linking the qnrS1 upstream sequence to lacZ was introduced into cells of the Keio collection with single gene deletions and screened for lacZ expression...
June 18, 2018: Antimicrobial Agents and Chemotherapy
José García, Dianny Martínez, Luisa Caña, Diorelis González, Lucy Rodríguez, Hectorina Rodulfo, Marcos De Donato, Militza Guzmán
BACKGROUND: Enterobacteria resistant to quinolones is increasing worldwide, including Venezuela. The mechanism for this resistance could be due to genes included in the chromosome or in transmissible plasmids. AIM: To evaluate the resistance to quinolones, coded by qnr genes present in enterobacteria species, isolated in the University Hospital of Cumana, Venezuela. METHODS: Antimicrobial susceptibility tests to quinolones, beta-lactams and aminoglycosides were carried out to all the isolates...
April 2018: Revista Chilena de Infectología: órgano Oficial de la Sociedad Chilena de Infectología
Danilo Garcia Sanchez, Fernanda Maciel de Melo, Eduardo Angelino Savazzi, Eliana Guedes Stehling
Bacterial resistance occurs by spontaneous mutations or horizontal gene transfer mediated by mobile genetic elements, which represents a great concern. Resistance to β-lactam antibiotics is mainly due to the production of β-lactamases, and an important mechanism of fluoroquinolone resistance is the acquisition plasmid determinants. The aim of this study was to verify the presence of β-lactamase-encoding genes and plasmid-mediated quinolone resistance genes in different water samples obtained from São Paulo state, Brazil...
June 16, 2018: Environmental Monitoring and Assessment
Zhen Zhu, Yuxiang Shi, Xuzheng Zhou, Bing Li, Jiyu Zhang
BACKGROUND: Members of the genus Shigella are intestinal pathogens and a major cause of seasonal outbreaks of bacterial diarrhea worldwide. Although humans are the conventional hosts of Shigella species, expansion of the Shigella host range to certain animals was recently reported. To investigate the prevalence of Shigella sonnei (S. sonnei) in yaks and perform molecular characterization, we analyzed 1132 fresh yak diarrheal stool samples and collected a total of 44 S. sonnei isolates...
June 7, 2018: BMC Veterinary Research
Qada Benameur, Hassiba Tali-Maamar, Farida Assaous, Badia Guettou, Meki Boutaiba Benklaouz, Kheira Rahal, Meriem-Hind Ben-Mahdi
Aim: Multidrug-resistant (MDR) Enterobacteriaceae have frequently been reported, in both human and veterinary medicine, from different parts of the world as a consequence of antibiotic usage. However, there is a lack of published data regarding antimicrobial resistance in non- Escherichia coli ( E. coli ) Enterobacteriaceae from animals in Algeria. This study aimed to evaluate the frequency of resistance to antibiotics with a focus on quinolones and to investigate the presence of qnr genes inEnterobacteriaceaeof poultry origin...
April 2018: Veterinary World
Lamis Galal, Neveen A Abdel Aziz, Walaa M Hassan
Fluoroquinolones and aminoglycosides offer effective therapy for extended-spectrum beta-lactamase (ESBL)-producing enterobacterial infections, but their usefulness is threatened by increasing resistant strains. OBJECTIVE: This study was conducted to demonstrate the phenotypic outcomes of the coexistence of genetic determinants mediating resistance to extended-spectrum cephalosporins and quinolones in enterobacterial isolates collected from patients with health-care-associated infections in Egypt...
May 11, 2018: Advances in Experimental Medicine and Biology
Hadis Abbasi, Reza Ranjbar
Introduction: Escherichia coli (E.coli) as an opportunistic pathogen is a major cause of the hospital infections. The main goal of this research was to determine the frequency of quinolone resistance genes (qnr) among E.coli pathotypes isolated from patients with urinary tract infections (UTIs). Material and methods: Urine samples were obtained from patients with UTIs in three major hospitals of Mofid, Bu Ali, and Vali-Asr during the year of 2015 in Tehran, Iran...
2018: Central European Journal of Urology
Amir Majlesi, Reza Kamali Kakhki, Amir Sasan Mozaffari Nejad, Rasoul Yousefi Mashouf, Amir Roointan, Malek Abazari, Mohammad Yousef Alikhani
Plasmid mediated quinolone resistance (PMQR) determinants have arisen as a significant concern in recent years. The aim of this study was screening of resistant-clinical isolates to fluoroquinolone antibiotics and detection of qnr and aac(6')-Ib-cr genes. For this purpose we collected 100 fluoroquinolone-resistant Enterobacteriaceae which were from 3 hospitals in Hamadan, west provinces of Iran, between October 2012 and June 2013. The all samples were identified by biochemical tests and confirmed by PCR method...
March 2018: Saudi Journal of Biological Sciences
I M Leon, S D Lawhon, K N Norman, D S Threadgill, N Ohta, J Vinasco, H M Scott
Although Salmonella enterica can produce life-threatening colitis in horses, certain serotypes are more commonly associated with clinical disease. Our aim was to evaluate the proportional morbidity attributed to different serotypes, as well as phenotypic and genotypic antimicrobial resistance (AMR) of Salmonella isolated from patients at an equine referral hospital in the southern United States. Two-hundred-fifty-five Salmonella isolates were obtained from clinical samples of patients admitted to the hospital between 2007 and 2015...
April 20, 2018: Applied and Environmental Microbiology
Babafela Awosile, Gregory German, Juan Carlos Rodriguez-Lecompte, Matthew E Saab, Luke C Heider, J Trenton McClure
The aim of this study was to determine the frequency of fecal carriage of vancomycin-resistant Enterococcus spp. and Escherichia coli with reduced susceptibilities to extended-spectrum cephalosporins (ESCs) and quinolones in humans on Prince Edward Island, Canada. Convenience fecal samples from individuals on Prince Edward Island were screened phenotypically using selective culture and genotypically using multiplex polymerase chain reactions to detect E. coli and Enterococcus spp. resistant to critically important antimicrobials...
April 5, 2018: Canadian Journal of Microbiology
Sergio Carrasco-Anabalón, Alejandra Vera-Leiva, Mario Quezada-Aguiluz, María F Morales-Rivera, Celia A Lima, Jorge Fernández, Soledad Ulloa, Mariana Domínguez, Gerardo González-Rocha, Helia Bello-Toledo
Objective: To elucidate whether the genetic platforms of bla CTX-M contribute to the phenotypes of multi-drug-resistance (MDR) in the first carbapenemase-producing K. pneumoniae strains isolated in Chile. Method: Twenty-two carbapenemase-producing K. pneumoniae strains isolated from different Chilean patients and hospitals were studied. Their genetic relatedness was assessed by PFGE and MLST. The levels of antibiotic resistance were evaluated by determining the minimum inhibitory concentration of various antimicrobials...
2018: Frontiers in Microbiology
Shahla Shahbazi, Mohammad Reza Asadi Karam, Mehri Habibi, Atefeh Talebi, Saeid Bouzari
OBJECTIVES: Antibiotic resistance among the Uropathogenic Escherichia coli (UPEC) is increasing. The aim of this study was to evaluate antimicrobial resistance in the UPEC isolates and their correlations with virulence factors. METHODS: A total of 120 E. coli isolates were collected from the patients with urinary tract infections in Tehran, Iran. Biofilm formation and antimicrobial susceptibilities were determined by phenotypic tests. Combination disk diffusion and modified Hodge tests (MHT) were performed for the phenotypic detection of ESBL and carbapenemase, respectively...
March 23, 2018: Journal of Global Antimicrobial Resistance
Mary K Phillips-Jones, Stephen E Harding
In this review, we discuss mechanisms of resistance identified in bacterial agents Staphylococcus aureus and the enterococci towards two priority classes of antibiotics-the fluoroquinolones and the glycopeptides. Members of both classes interact with a number of components in the cells of these bacteria, so the cellular targets are also considered. Fluoroquinolone resistance mechanisms include efflux pumps (MepA, NorA, NorB, NorC, MdeA, LmrS or SdrM in S. aureus and EfmA or EfrAB in the enterococci) for removal of fluoroquinolone from the intracellular environment of bacterial cells and/or protection of the gyrase and topoisomerase IV target sites in Enterococcus faecalis by Qnr-like proteins...
April 2018: Biophysical Reviews
Anno de Jong, Anaëlle Muggeo, Farid El Garch, Hilde Moyaert, Christophe de Champs, Thomas Guillard
ComPath is an ongoing European programme dedicated to monitor antibiotic susceptibility of bacterial pathogens from diseased dogs and cats. The objective was to characterize determinants associated with quinolone resistance among 160 enrofloxacin non-wild type strains (100 Escherichia coli, 45 Proteus mirabilis, 14 Klebsiella pneumoniae, 1 Enterobacter cloacae) selected among 843 non-duplicate Enterobacteriaceae isolates collected in 12 European countries (2013-2014). These strains with non-wild type MICs of ≥0...
March 2018: Veterinary Microbiology
Orsolya Szabó, Dániel Gulyás, Nikolett Szabó, Katalin Kristóf, Béla Kocsis, Dóra Szabó
Plasmid-mediated quinolone resistance (PMQR) determinants including, qnrA, qnrB, qnrC, qnrD, qnrS, aac(6')-Ib-cr, oqxAB, and qepA, were investigated in 214 Enterobacteriaceae strains from urine clinical samples. Antimicrobial susceptibility testing for ciprofloxacin, ceftriaxone, and imipenem was performed by broth microdilution method. All strains were screened for PMQR genes by PCR. Virulence determinants, namely afa, pap, pil, sfa/foc, and kpsMT of eight Escherichia coli strains proven positive for at least one qnr gene, were investigated by PCR...
February 23, 2018: Acta Microbiologica et Immunologica Hungarica
Moisés Francisco, Sofia Santos Costa, Adriana Belas, Jorge Ramos, Isabel Couto, Constança Pomba, Miguel Viveiros
OBJECTIVES: Typhoid fever is a common infection in Africa and in spite of scarce surveillance reports, its incidence is commonly considered high by the Angolan Health system. Drug-resistant Salmonella enterica serotype Typhi has emerged, turning antimicrobial susceptibility testing essential to provide clinical guidance. This is the first report analyzing antimicrobial resistance patterns and population structure of the few S. enterica ser. Typhi isolated from patients with Typhoid fever in Luanda, Angola...
February 9, 2018: Journal of Global Antimicrobial Resistance
Joaquim Ruiz
Background: Twenty years ago the first transferable mechanism of quinolone resistance (TMQR), QnrA, was described. Thereafter, innumerable TMQRs, either Qnr related or not, were described. Ten years ago the exponential description of Qnr genes/alleles led to the proposal of a common nomenclature. Objectives: This analysis aims to determine the degree of correctness of the Qnr sequences currently present in GenBank. Methods: The Qnr amino acid type sequence of the first allele (e...
February 3, 2018: Journal of Antimicrobial Chemotherapy
Neha Rajpara, Mrinalini Nair, Goutam Chowdhury, Asish K Mukhopadhyay, Thandavarayan Ramamurthy, Swapan Kumar Niyogi, Ashima Kushwaha Bhardwaj
To understand the genetic basis of high drug resistance in Shigella , 95 clinical isolates of Shigella spp. (2001-2010) were obtained from the Infectious Diseases Hospital, Kolkata, India. Ninety-three isolates were resistant to three or more antibiotics. Resistance to nalidixic acid, trimethoprim, streptomycin, and co-trimoxazole was most common in this population. Dendrogram analysis showed that S. sonnei strains were more clonally related when compared to the other Shigella species. The role of mobile genetic elements and chromosome-borne resistance factors was analyzed in detail...
2018: Infection and Drug Resistance
Laura Vinué, David C Hooper, George A Jacoby
We examined 13 qnr-positive and 14 qnr-negative clinical isolates of Escherichia coli for mutations previously seen in a qnr-containing laboratory strain exposed to supra minimum inhibitory concentrations (MICs) of ciprofloxacin. Among the qnr-positive strains, those with ciprofloxacin MICs of ≥ 2 µg/mL had at least one mutation in gyrA. Mutations in parC were present in strains with a ciprofloxacin MIC of ≥ 128 µg/mL. The 6 most ciprofloxacin-resistant strains contained additional plasmid-mediated quinolone resistance determinants...
March 2018: International Journal of Antimicrobial Agents
Mansour Amin, Solmaz Dibachi, Mojtaba Shahin
Quinolones are frequently used classes of antimicrobials in hospitals, crucial for the treatment of infections caused by Gram-negative bacteria. The inappropriate use of quinolones and other antimicrobial agents for the treatment of bacterial infections leads to a significant increase of resistant isolates. The acquisition of antimicrobial resistance may be related to achievement of resistance determinant genes mediated by plasmids, transposons and gene cassettes in integrons. The objective of this cross-sectional study, conducted from December 2015 to July 2016 at two teaching hospitals in Ahvaz, southern Iran, was to screen for the presence of class 1 integrons and quinolone resistance genes in clinical isolates of Enterobacter spp...
December 1, 2017: Le Infezioni in Medicina
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