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Łukasz Mąka, Magdalena Popowska
This review summarizes current data on resistance among Salmonella spp. isolates of food origin from countries in different regions of the world. The mechanisms of resistance to different groups of antimicrobial compounds are also considered. Among strains resistant to quinolones and/or fluoroquinolones the most prevalent mechanism is amino acid substitutions in quinolone resistance-determining region (QRDR) of genes gyrA, parC but mechanism of growing importance is plasmid-mediated quinolone resistance (PMQR) associated with genes qnrA, qnrB, qnrC, qnrD, qnrS but frequency of their detection is different...
2016: Roczniki Państwowego Zakładu Higieny
Haima Mylvaganam, Helge Kolstad, Rebecca Irene Breistein, Grete Lind, Dag Harald Skutlaberg
Routine surveillance of resistance to broad-spectrum cephalosporins in Enterobacteriaceae and phenotypic identification of underlying mechanisms using a simple strategy was commenced in 2006 at our laboratory, serving West Norway. This report focuses on the results until 2013. The classical plasmid-mediated extended spectrum beta-lactamase (ESBLA ) among clinically relevant Escherichia coli isolates showed an increase from 0.6% to 4.3% during the surveillance period, while prevalence for other mechanisms remained stable, below 0...
December 6, 2016: APMIS: Acta Pathologica, Microbiologica, et Immunologica Scandinavica
Maria Del Carmen López-Diaz, Esther Culebras, Iciar Rodríguez-Avial, Esther Rios, José Manuel Viñuela-Prieto, Juan J Picazo, Carmen Rodríguez-Avial
The activity of plazomicin and clinically relevant aminoglycosides were tested against 346 ESBL/AmpC-producer Escherichia coli urinary isolates and the results were correlated with the presence of aminoglycoside-modifying enzymes (AMEs).Data showed that plazomicin was very active against all ESBL/AmpC-producing E. coli urinary isolates. Its activity was not related to the AME genes studied.
December 5, 2016: Antimicrobial Agents and Chemotherapy
Xiaoqiang Liu, Haixia Liu, Yinqian Li, Caiju Hao
Objective: The aim of this study was to investigate the occurrence and molecular characterization of extended-spectrum β-lactamases (ESBL), plasmid-mediated AmpC β-lactamase (pAmpC) and carbapenemases as well as plasmid-mediated quinolone-resistant (PMQR) among extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli from dogs in Shaanxi province in China. Methods: A total of 40 ESC-R Escherichia coli selected from 165 Extraintestinal pathogenic E. coli (ExPEC) isolated from dogs were screened and characterized for the genes encoding for the ESBLs, pAmpC, carbapenemases and PMQR genes by PCR and sequencing...
2016: Frontiers in Microbiology
Jing Zhang, Kai Zhou, Beiwen Zheng, Lina Zhao, Ping Shen, Jinru Ji, Zeqing Wei, Lanjuan Li, Jianying Zhou, Yonghong Xiao
The aim of this work was to investigate the epidemiological and genetic characteristics of ESBL-producing Klebsiella pneumoniae (ESBL-Kp) causing community-onset infections. K. pneumoniae isolates were collected from 31 Chinese secondary hospitals between August 2010 and 2011. Genes encoding ESBL and AmpC beta-lactamases were detected by PCR. The isolates were assigned to sequence types (STs) using multi-locus sequence typing (MLST). Eleven ESBL-Kp strains were selected for whole-genome sequencing (WGS) for investigating the genetic environment and plasmids encoding ESBL genes...
2016: Frontiers in Microbiology
B Yanat, J-M Rodríguez-Martínez, A Touati
Quinolones are a family of synthetic broad-spectrum antimicrobial drugs. These molecules have been widely prescribed to treat various infectious diseases and have been classified into several generations based on their spectrum of activity. Quinolones inhibit bacterial DNA synthesis by interfering with the action of DNA gyrase and topoisomerase IV. Mutations in the genes encoding these targets are the most common mechanisms of high-level fluoroquinolone resistance. Moreover, three mechanisms for plasmid-mediated quinolone resistance (PMQR) have been discovered since 1998 and include Qnr proteins, the aminoglycoside acetyltransferase AAC(6')-Ib-cr, and plasmid-mediated efflux pumps QepA and OqxAB...
November 26, 2016: European Journal of Clinical Microbiology & Infectious Diseases
Inmaculada López-Hernández, Noemí Alonso, Marta Fernández-Martínez, Laura Zamorano, Alba Rivera, Antonio Oliver, M Carmen Conejo, Luis Martínez-Martínez, Ferrán Navarro, Alvaro Pascual
INTRODUCTION: Antimicrobial resistance in Enterobacteriaceae is increasing worldwide and is making treating infections caused by multidrug-resistant Enterobacteriaceae a challenge. The use of β-lactam agents is compromised by microorganisms harboring extended-spectrum β-lactamases (ESBLs) and other mechanisms of resistance. Avibactam is a non β-lactam agent that inhibits clinically relevant β-lactamases, such as ESBL and AmpC. The ceftazidime-avibactam combination (CAZ-AVI) was recently approved for use in certain complicated infections, and may provide a therapeutic alternative for infections caused by these microorganisms...
November 22, 2016: Enfermedades Infecciosas y Microbiología Clínica
I M G A Santman-Berends, M A Gonggrijp, J J Hage, A E Heuvelink, A Velthuis, T J G M Lam, G van Schaik
Extended-spectrum β-lactamase and AmpC-producing Escherichia coli (ESBL/AmpC) are an emerging problem and are hypothesized to be associated with antimicrobial use (AMU), and more specifically with the use of third- and fourth-generation cephalosporins. Whether ESBL/AmpC also occur in organic dairy herds, which have restricted AMU, is not known. Additionally, it is unknown whether, in addition to restricted AMU, other factors in organic herd management are associated with ESBL/AmpC herd status. The aim of this study was to estimate the prevalence of ESBL/AmpC in organic dairy herds in the Netherlands...
November 16, 2016: Journal of Dairy Science
Sana Ferjani, Mabrouka Saidani, Zeineb Hamzaoui, Carla Andrea Alonso, Carmen Torres, Elaa Maamar, Amine Faouzi Slim, Ben Boubaker Ilhem Boutiba
The spread of extended spectrum β-lactamases (ESBL) and plasmid mediated AmpC β-lactamases (pAmpC) was evaluated in Escherichia coli strains collected from the intestinal microbiota of healthy children in Tunisia. The carriage rate of CTX(R)E. coli was 6.6% (7 of 105 samples) and one strain/sample was further characterized (7 isolates). These isolates harbored blaCTX-M-1 (n = 4), blaCTX-M-15 (n = 2), and blaCMY-2 gene (n = 1), which were usually located on FIB replicon type and carried class 1 integrons. The acc(6')-Ib-cr variant was identified in one isolate that harbored blaCTX-M-15...
March 8, 2016: Diagnostic Microbiology and Infectious Disease
Y Y Li, F Cassidy, A Salmon, D Keating, C M Herra, K Schaffer
This study determined the prevalence and distribution of plasmid-mediated AmpC (pAmpC) β-lactamases in Irish Escherichia coli isolates. Clinical E. coli isolates (n=95) that were intermediate or resistant to cefoxitin and/or flagged by VITEK(®) 2 as potential AmpC-producers underwent confirmation using a MASTDISCS™ ESBL and AmpC Detection Kit. Multiplex PCR capable of detecting family-specific plasmid ampC genes was performed to detect the presence of these genes. Five PCR-negative isolates were selected for promoter analysis...
December 2015: Journal of Global Antimicrobial Resistance
Wu-Pu Lin, Jann-Tay Wang, Shan-Chwen Chang, Feng-Yee Chang, Chang-Phone Fung, Yin-Ching Chuang, Yao-Shen Chen, Yih-Ru Shiau, Mei-Chen Tan, Hui-Ying Wang, Jui-Fen Lai, I-Wen Huang, Tsai-Ling Lauderdale
Drug-resistant Klebsiella pneumoniae, especially extended-spectrum β-lactamase (ESBL)- and/or AmpC β-lactamase-producing strains, is an emerging problem worldwide. However, few data focusing on drug susceptibility of K. pneumoniae from community is available. In this study, we analyzed 1016 K. pneumoniae isolates from outpatients or those visiting emergency rooms collected during 2002-2012 from Taiwan Surveillance of Antimicrobial Resistance program. Significantly decreased susceptibilities to 3(rd) generation cephalosporins and ciprofloxacin were found during the study period...
November 8, 2016: Scientific Reports
L P Randall, M P Lodge, N C Elviss, F L Lemma, K L Hopkins, C J Teale, N Woodford
We determined the prevalence and types of extended-spectrum β-lactamase (ESBL)-producing and carbapenem-resistant Escherichia coli in raw retail beef, chicken, pork, fruit and vegetables in five UK regions in 2013-14. Raw meat (n=397), and fruit and vegetable samples (n=400) were purchased from retail stores in London, East Anglia, North West England, Scotland and Wales. Samples were tested for the presence of ESBL-producing E. coli by plating enriched samples on CHROMagar CTX and CHROMagar ESBL, for AmpC-type E...
October 29, 2016: International Journal of Food Microbiology
Lu Huang, Yan-Bin Xu, Jia-Xin Xu, Jia-Yin Ling, Jin-Liang Chen, Jia-Le Zhou, Li Zheng, Qing-Ping Du
Antibiotic resistance genes (ARGs) are emerging micropollutants with environmental persistence. Aquaculture environments are considered as potential reservoirs for ARGs pollution and horizontal gene transfer (HGT). This study analyzed water and sediment from eight culture ponds (integrated culture: duck-fish pond; monoculture: duck pond and fish pond) and a control pond (without any aquaculture activity) in Zhongshan, South China. Seventeen types of ARGs were detected in all ponds, which conferring resistance to four classes of antibiotics including tetracycline (tetA, tetB, tetC, tetE, tetG, tetL, tetA-P, tetM, tetO, tetS, tetW and tetX), AmpC beta-lactamase products (EBC and FOX), sulfonamide (sul1 and sul2) and erythromycin (ermA), with class 1 integron (intI1) as motility gene...
November 2, 2016: Chemosphere
Yusaku Kajihara, Tadashi Shimoyama, Ichiro Mizuki
BACKGROUND: Vonoprazan (VPZ)-based triple therapy has been reported to have greater efficacy than a proton pump inhibitor (PPI)-based triple therapy for Helicobacter pylori (H. pylori) eradication. However, because VPZ is more expensive than PPIs such as rabeprazole (RPZ), economic evaluation is essential. METHODS: We performed a retrospective study on 209 patients who underwent first-line eradication of H. pylori infection in Fuyoukai Murakami Hospital from 1 March 2015 to 31 March 2016...
November 3, 2016: Scandinavian Journal of Gastroenterology
Ria van Boxtel, Agnes A Wattel, Jesús Arenas, Wil H F Goessens, Jan Tommassen
Although AmpC β-lactamases can barely or not degrade carbapenems, they can sequester them and prevent them from reaching their targets. Thus, carbapenem resistance in Escherichia coli and other Enterobacteriaceae can result from production of AmpC and simultaneous reduction of antibiotic influx into the periplasm by mutations in the porin genes. Here, we investigated the route and genetic mechanisms of acquiring carbapenem resistance in a clinical E. coli isolate carrying blaCMY-2 on a plasmid by selecting for mutants that are resistant to increasing concentrations of meropenem...
October 31, 2016: Antimicrobial Agents and Chemotherapy
Jeong-Hwan Hwang, Gee-Wook Shin, Joo-Hee Hwang, Chang-Seop Lee
A 57-year-old man presented with a high fever and diarrhea. A blood culture showed the presence of a Group C nontyphoidal Salmonella isolate. On Salmonella serotyping, the isolate was Salmonella enterica serovar Virchow. Its sequence type was determined to be ST16 by sequence analysis of seven different housekeeping genes. The blaCTX-M group 1 and blaTEM genes were amplified by multiplex PCR assays for detecting ESBL genes. Sequences of both amplicons were respectively identical to CTX-M-15- and TEM-1-encoding genes...
October 31, 2016: Japanese Journal of Infectious Diseases
Marcelo Pérez-Gallego, Gabriel Torrens, Jane Castillo-Vera, Bartolomé Moya, Laura Zamorano, Gabriel Cabot, Kjell Hultenby, Sebastián Albertí, Peter Mellroth, Birgitta Henriques-Normark, Staffan Normark, Antonio Oliver, Carlos Juan
: Understanding the interplay between antibiotic resistance and bacterial fitness and virulence is essential to guide individual treatments and improve global antibiotic policies. A paradigmatic example of a resistance mechanism is the intrinsic inducible chromosomal β-lactamase AmpC from multiple Gram-negative bacteria, including Pseudomonas aeruginosa, a major nosocomial pathogen. The regulation of ampC expression is intimately linked to peptidoglycan recycling, and AmpC-mediated β-lactam resistance is frequently mediated by inactivating mutations in ampD, encoding an N-acetyl-anhydromuramyl-l-alanine amidase, affecting the levels of ampC-activating muropeptides...
October 25, 2016: MBio
Michaela Projahn, Katrin Daehre, Uwe Roesler, Anika Friese
: Antimicrobial resistance through extended-spectrum beta-lactamases (ESBLs) and transferable AmpC beta-lactamases represents an increasing problem in human and veterinary medicine. The presence of ESBL-/pAmpC-producing commensal enterobacteria in farm animals such as broiler chicken is considered as one possible source of food contamination and could, therefore, also be relevant for human colonization. Studies on transmission routes along the broiler production chain showed that already one-day old hatchlings are affected...
October 21, 2016: Applied and Environmental Microbiology
G van den Bunt, A Liakopoulos, D J Mevius, Y Geurts, A C Fluit, M J M Bonten, L Mughini-Gras, W van Pelt
OBJECTIVES: ESBL/AmpC-producing Enterobacteriaceae are an emerging public health concern. As households with preschool children may substantially contribute to the community burden of antimicrobial resistance, we determined the prevalence, risk factors and co-carriage of ESBL/AmpC-producing bacteria in preschool children and their parents. METHODS: From April 2013 to January 2015, each month 2000 preschool children were randomly selected from Dutch population registries...
October 26, 2016: Journal of Antimicrobial Chemotherapy
P M K Njage, E M Buys
The contribution of the fresh produce production environment to human exposure with bacteria bearing extended spectrum β-lactamases and AmpC β-lactamases (ESBL/AmpC) has not been reported. High prevalence of ESBLs/AmpC bearing E. coli as well as a high gene transfer efficiency of lettuce and irrigation water E. coli isolates was previously reported. This stochastic modeling was aimed at quantitatively assessing human exposure to ESBL/AmpC bearing E. coli through lettuce attributable to irrigation water and subsequent horizontal gene transfer...
January 2, 2017: International Journal of Food Microbiology
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