scholarly journals Contribution of Different Mechanisms to Ciprofloxacin Resistance in Salmonella spp.

2021 ◽  
Vol 12 ◽  
Author(s):  
Man-Xia Chang ◽  
Jin-Fei Zhang ◽  
Yin-Huan Sun ◽  
Rong-Sheng Li ◽  
Xiao-Ling Lin ◽  
...  
Keyword(s):  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Gene Location ◽  
Fluoroquinolone Resistance ◽  
Salmonella Spp ◽  
Resistance Development ◽  
Bacterial Fitness ◽  
Ciprofloxacin Resistance ◽  
Gyra Mutation ◽  
Chromosomal Mutations

Development of fluoroquinolone resistance can involve several mechanisms that include chromosomal mutations in genes (gyrAB and parCE) encoding the target bacterial topoisomerase enzymes, increased expression of the AcrAB-TolC efflux system, and acquisition of transmissible quinolone-resistance genes. In this study, 176 Salmonella isolates from animals with a broad range of ciprofloxacin MICs were collected to analyze the contribution of these different mechanisms to different phenotypes. All isolates were classified according to their ciprofloxacin susceptibility pattern into five groups as follows: highly resistant (HR), resistant (R), intermediate (I), reduced susceptibility (RS), and susceptible (S). We found that the ParC T57S substitution was common in strains exhibiting lowest MICs of ciprofloxacin while increased MICs depended on the type of GyrA mutation. The ParC T57S substitution appeared to incur little cost to bacterial fitness on its own. The presence of PMQR genes represented an route for resistance development in the absence of target-site mutations. Switching of the plasmid-mediated quinolone resistance (PMQR) gene location from a plasmid to the chromosome was observed and resulted in decreased ciprofloxacin susceptibility; this also correlated with increased fitness and a stable resistance phenotype. The overexpression of AcrAB-TolC played an important role in isolates with small decreases in susceptibility and expression was upregulated by MarA more often than by RamA. This study increases our understanding of the relative importance of several resistance mechanisms in the development of fluoroquinolone resistance in Salmonella from the food chain.

scholarly journals Investigation of Ciprofloxacin Resistance and Its Mechanisms in Clinical Pseudomonas aeruginosa Isolates

ANKEM Dergisi ◽  
2021 ◽  
Author(s):  
Nilüfer Uzunbayır Akel ◽  
Yamaç Tekintaş ◽  
Fethiye Ferda Yılmaz ◽  
İsmail Öztürk ◽  
Mustafa Ökeer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Regulatory Genes ◽  
Quinolone Resistance ◽  
University Hospital ◽  
Clinical Samples ◽  
Genetic Groups ◽  
Ciprofloxacin Resistance ◽  
Polymerase Chain

Pseudomonas aeruginosa is one of the most important causes of hospital infections. Although different antibiotic groups are used for the treatment of P.aeruginosa infections, quinolone groups are distinguished by the advantages of oral administration. However, in recent years, resistance against members of this group has made treatment more difficult. The aim of this study was to investigate the epidemiological relationship and possible mechanisms of resistance in ciprofloxacin resistant P. aeruginosa isolates from Ege University Hospital. The identification of P.aeruginosa bacteria isolated from clinical samples in Ege University Medical Faculty Medical Microbiology Laboratory was determined by VITEK MS automated systems by VITEK compact, antimicrobial susceptibility. The epidemiological relationships of the ciprofloxacin resistant isolates were determined by Enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR). The presence of qnrA, qnrB, qnrS, qepA genes, the quinolone resistance genes and nfxB, mexR, the regulatory genes of the efflux pump, was determined by PCR. The phenylalanine-arginine β-naphthylamide (PAβN) assay was used to determine the activation of the efflux pump. Twenty-two isolates (26.5 %) were found resistant to ciprofloxacin. According to the ERIC-PCR results, 11 unrelated clones were detected. Ciprofloxacin minimum inhibitory concentration (MIC) values were decreased 2-64 times in 10 isolates in the presence of PAIN. No ciprofloxacin MIC change was detected in one isolate. The presence of pump regulatory genes was determined in 10 of the 11 representative isolates, while only qnrB of the genes associated with quinolone resistance was detected in seven representative isolates. qnrA, qnrS, qepA genes were not detected in any isolate. Ciprofloxacin resistant P.aeruginosa isolates are isolated from our hospital. It is noteworthy that the isolates belonging to different genetic groups are in circulation in clinics. Basic resistance mechanisms are thought to be efflux pumps and qnrB genes.

scholarly journals Comparative Analysis of Quinolone Resistance in Clinical Isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese Children and Adults

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Huang ◽  
James O. Ogutu ◽  
Jiarui Gu ◽  
Fengshu Ding ◽  
Yuhong You ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Environmental Issues ◽  
Quinolone Resistance ◽  
Clinical Isolates ◽  
Fluoroquinolone Resistance ◽  
Chinese Adults ◽  
Double Mutation ◽  
History Of ◽  
Ciprofloxacin Resistance ◽  
Resistance Rates

The objective of this study was to compare quinolone resistance andgyrAmutations in clinical isolates ofKlebsiella pneumoniaeandEscherichia colifrom Chinese adults who used quinolone in the preceding month and children without any known history of quinolone administration. The antimicrobial susceptibilities of 61 isolates from children and 79 isolates from adults were determined. The mutations in the quinolone resistance-determining regions ingyrAgene were detected by PCR and DNA sequencing. Fluoroquinolone resistance and types ofgyrAmutations in isolates from children and adults were compared and statistically analyzed. No significant differences were detected in the resistance rates of ciprofloxacin and levofloxacin between children and adults among isolates of the two species (allP>0.05). The double mutation Ser83→Leu + Asp87→Asn in the ciprofloxacin-resistant isolates occurred in 73.7% isolates from the children and 67.9% from the adults, respectively (P=0.5444). Children with no known history of quinolone administration were found to carry fluoroquinolone-resistantEnterobacteriaceaeisolates. The occurrence of ciprofloxacin resistance and the major types ofgyrAmutations in the isolates from the children were similar to those from adults. The results indicate that precautions should be taken on environmental issues resulting from widespread transmission of quinolone resistance.

scholarly journals Overexpression of Efflux Pumps, Mutations in the Pumps’ Regulators, Chromosomal Mutations, and AAC(6′)-Ib-cr Are Associated With Fluoroquinolone Resistance in Diverse Sequence Types of Neonatal Septicaemic Acinetobacter baumannii: A 7-Year Single Center Study

2021 ◽  
Vol 12 ◽  
Author(s):  
Subhasree Roy ◽  
Somdatta Chatterjee ◽  
Amrita Bhattacharjee ◽  
Pinaki Chattopadhyay ◽  
Bijan Saha ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Efflux Pump ◽  
Critical Role ◽  
Holistic Approach ◽  
Efflux Pumps ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance ◽  
Active Efflux ◽  
Chromosomal Mutations ◽  
Sequence Types

This study investigates susceptibility toward three fluoroquinolones (ciprofloxacin, levofloxacin, moxifloxacin), multiple fluoroquinolone-resistance mechanisms, and epidemiological relationship of neonatal septicaemic Acinetobacter baumannii. Previous studies on fluoroquinolone resistance in A. baumannii focused primarily on ciprofloxacin susceptibility and assessed a particular mechanism of resistance; a more holistic approach was taken here. Epidemiological relationship was evaluated by Multi Locus Sequence Typing. Minimum Inhibitory Concentrations of fluoroquinolones was determined with and without efflux pump inhibitors. Overexpression of efflux pumps, resistance-nodulation-cell-division (RND)-type, and multidrug and toxic compound extrusion (MATE)-type efflux pumps were evaluated by reverse transcriptase-qPCR. Mutations within regulatory proteins (AdeRS, AdeN, and AdeL) of RND-pumps were examined. Chromosomal mutations, presence of qnr and aac(6′)-Ib-cr were investigated. A. baumannii were highly diverse as 24 sequence-types with seven novel STs (ST-1440/ST-1441/ST-1481/ST-1482/ST-1483/ST-1484/ST-1486) were identified among 47 A. baumannii. High resistance to ciprofloxacin (96%), levofloxacin (92%), and particularly moxifloxacin (90%) was observed, with multiple mechanisms being active. Resistance to 4th generation fluoroquinolone (moxifloxacin) in neonatal isolates is worrisome. Mutations within GyrA (S83L) and ParC (S80L) were detected in more than 90% of fluoroquinolone-resistant A. baumannii (FQRAB) spread across 10 different clonal complexes (CC1/CC2/CC10/CC25/CC32/CC126/CC149/CC216/CC218/CC513). Efflux-based FQ resistance was found in 65% of FQRAB with ≥2 different active pumps in 38% of strains. Overexpression of adeB was highest (2.2−34-folds) followed by adeJ, adeG, and abeM. Amino acid changes in the regulators (AdeRS/AdeN/AdeL) either as single or multiple substitutions substantiated the overexpression of the pumps. Diverse mutations within AdeRS were detected among different CCs whereas mutations within AdeN linked to CC10 and CC32. Chromosomal mutations and active efflux pumps were detected simultaneously among 64% of FQRAB. Presence of aac(6′)-Ib-cr was also high (74% of FQRAB) but qnrS were absent. As most FQRABs had chromosomal mutations, this was considered predominant, however, isolates where pumps were also active had higher MIC values, establishing the critical role of the efflux pumps. The high variability of FQ susceptibility among FQRAB, possessing the same set of mutations in gyrA, parC, and efflux pump regulators, was also noted. This reveals the complexity of interpreting the interplay of multiple resistance mechanisms in A. baumannii.

scholarly journals Distribution of ciprofloxacin-resistance genes among ST131 and non-ST131 clones of Escherichia coli isolates with ESBL phenotypes isolated from women with urinary tract infection

2021 ◽  
Author(s):  
Masoumeh Rasoulinasab ◽  
Fereshteh Shahcheraghi ◽  
Mohammad Mehdi Feizabadi ◽  
Bahram Nikmanesh ◽  
Azade Hajihasani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Resistance Rate ◽  
Fluoroquinolone Resistance ◽  
Double Mutation ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Specific Pcr ◽  
Ciprofloxacin Resistance ◽  
Chromosomal Mutations ◽  
Esbl Producers

Background and Objectives: Escherichia coli (E. coli) sequence type 131 (ST131) is associated with extended-spectrum beta-lactamase (ESBL) production and fluoroquinolone resistance. This study aimed to investigate the prevalence of ST131, ESBL, and plasmid-mediated quinolone resistance (PMQR) genes in the ciprofloxacin-resistant (CIPR ) and ESBL producers from women with UTI. Materials and Methods: The CIP-resistant ESBL producing (CIPR /ESBL+ ) E. coli isolates were screened for ST131-by specific PCR of mdh and gyrB. The ESBL and PMQR genes were screened by single PCR. The ST131 and non-ST131 isolates were selected to determine the mutations of gyrA and parC using PCR and sequencing, and also their genetic background by the Pasteur-MLST scheme. Results: Overall, 55% (33/60) CIPR /ESBL+ isolates were identified as ST131 (94% O25b-ST131). Resistance rate to ampicillin-sulbactam (70%), aztreonam (97%) and gentamicin (61%), the prevalence of aac(6′)-Ib-cr (66%), blaCTX-M-15 (82%), the profile of qnrS+aac(6′)-Ib-cr (30%), and the double mutation in the parC was significantly higher in ST131 than nonST131 isolates. The coexistence of PMQR and ESBL genes was found in more than 50% of ST131 and non-ST131 isolates. ST131 isolates differentiated into PST43 and PST506. Conclusion: Management of women with UTI caused by the CIPR /ESBL+ isolates (ST131) co-harbored PMQR, ESBL, and chromosomal mutations, is important for their effective therapy.

Prevalence and characterisation of quinolone resistance mechanisms in Salmonella spp.

2014 ◽  
Vol 171 (3-4) ◽  
pp. 307-314 ◽  
Author(s):  
Dariusz Wasyl ◽  
Andrzej Hoszowski ◽  
Magdalena Zając
Keyword(s):  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Salmonella Spp

Molecular Characterization of Fluoroquinolone Resistance Mechanisms of Campylobacter Isolates from Duck Meats

2017 ◽  
Vol 80 (12) ◽  
pp. 2056-2059
Author(s):  
Min Kang ◽  
Bai Wei ◽  
Sung-Woon Choi ◽  
Se-Yeoun Cha ◽  
Hyung-Kwan Jang
Keyword(s):  
Nalidixic Acid ◽  
Efflux Pump ◽  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Gyra Gene ◽  
Meat Samples ◽  
High Level ◽  
Level Resistance

ABSTRACT The purpose of this study was to identify the molecular basis of quinolone resistance of Campylobacter isolates recovered from duck meats. Sixty-one isolates from duck meat samples were studied using sequence analysis of the gyrA gene, and PCR assays were used to identify the presence of the CmeABC efflux pump and its restored sensitivity in the presence of efflux-pump inhibitors. High-level resistance to nalidixic acid and ciprofloxacin was attributed to amino acid substitutions Thr-86-Ile in some isolates. The PCR assay confirmed the presence of the cmeB gene in 29 (47.5%) of the 61 Campylobacter isolates. Phenylalanine arginine β-naphthylamide reduced the MICs of ciprofloxacin and nalidixic acid in 16 (55.2%) and 26 (89.7%) isolates, respectively. The Thr-86-Ile substitution in the gyrA was the primary contributor to the high-level quinolone resistance in Campylobacter isolates from duck meats.

scholarly journals Plasmid-mediated quinolone resistance by genes qnrA1 and qnrB19 in Salmonella strains isolated in Brazil

2011 ◽  
Vol 5 (06) ◽  
pp. 496-498 ◽  
Author(s):  
Rafaela Ferrari ◽  
Antonio Galiana ◽  
Rosa Cremades ◽  
Juan Carlos Rodriguez ◽  
Marciane Magnani ◽  
...  
Keyword(s):  
Resistance Mechanisms ◽  
Quinolone Resistance ◽  
Poultry Production ◽  
Salmonella Spp ◽  
Mutant Selection ◽  
Microbial Resistance ◽  
Resistance Profile ◽  
Resistant Strains ◽  
Near Future ◽  
Selection Of

Considering the importance of the mechanisms involved in quinolone resistance, this study evaluate the presence of PMQR in 126 epidemic and not epidemic strains of Salmonella spp. It was noted that presence of PMQR, by itself, did not generate resistance to ciprofloxacin;  but detection of qnr genes in Salmonella spp. and the identification of the qnrB19 variant in a strain of poultry origin alert for the indiscriminate use of quinolones in poultry production, that can result in a pressure for mutant selection of resistant strains with a clinical limitation use of FQs in the near future. And last but not least, is the need to continued study of resistance mechanisms and to monitor the microbial resistance profile of epidemiological strains.

scholarly journals Molecular Characterization of Increasing Fluoroquinolone Resistance in Streptococcus pneumoniae Isolates in Canada, 1997 to 2005

2006 ◽  
Vol 51 (1) ◽  
pp. 198-207 ◽  
Author(s):  
Heather J. Adam ◽  
Kristen N. Schurek ◽  
Kimberly A. Nichol ◽  
Chris J. Hoban ◽  
Trish J. Baudry ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Early Detection ◽  
Molecular Characterization ◽  
Gel Electrophoresis ◽  
Resistance Mechanisms ◽  
Pulsed Field Gel Electrophoresis ◽  
Fluoroquinolone Resistance ◽  
Pulsed Field ◽  
Ciprofloxacin Resistance

ABSTRACT Molecular characterization of fluoroquinolone-resistant Streptococcus pneumoniae in Canada was conducted from 1997 to 2005. Over the course of the study, 205 ciprofloxacin-resistant isolates were evaluated for ParC and GyrA quinolone resistance-determining region (QRDR) substitutions, substitutions in the full genes of ParC, ParE, and GyrA, reserpine sensitivity, and serotype and by pulsed-field gel electrophoresis. Rates of ciprofloxacin resistance of S. pneumoniae increased significantly, from less than 1% in 1997 to 4.2% in 2005. Ciprofloxacin resistance was greatest in people >64 years of age and least in those <16 years of age. Significant increases were also noted in rates of resistance to gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin, to the current rates of 1.6%, 1.0%, 1.1%, and 1.0%, respectively. The most common genotype observed consisted of QRDR substitutions in GyrA (Ser81Phe) and ParC (Ser79Phe). Substitutions outside the QRDR of GyrA, ParC, and ParE were not associated with fluoroquinolone resistance in this study. Overall, 21% of isolates were reserpine-sensitive and were thus assumed to be efflux positive. The ciprofloxacin-resistant isolates belonged to 35 different serotypes, but 10 (19F, 11A, 23F, 6B, 22F, 12F, 6A, 14, 9V, and 19A) accounted for 72% of all isolates. The majority of the isolates were found to be genetically unrelated by pulsed-field gel electrophoresis. Within the observed clusters, there was considerable genetic heterogeneity with regard to fluoroquinolone resistance mechanisms and serotypes. Continued surveillance and molecular analysis of fluoroquinolone-resistant S. pneumoniae in Canada are essential for appropriate empirical treatment of infections and early detection of novel resistance mechanisms.

scholarly journals Molecular Analysis of Ciprofloxacin Resistance Mechanisms in Malaysian ESBL-ProducingKlebsiella pneumoniaeIsolates and Development of Mismatch Amplification Mutation Assays (MAMA) for Rapid Detection ofgyrAandparCMutations

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Farah Al-Marzooq ◽  
Mohd Yasim Mohd Yusof ◽  
Sun Tee Tay
Keyword(s):  
Klebsiella Pneumoniae ◽  
Infection Control ◽  
Molecular Analysis ◽  
Rapid Detection ◽  
Resistance Mechanisms ◽  
Control Measures ◽  
Quinolone Resistance ◽  
Infection Control Measures ◽  
High Prevalence ◽  
Ciprofloxacin Resistance

Ninety-three Malaysian extended-spectrumβ-lactamase (ESBL)-producingKlebsiella pneumoniaeisolates were investigated for ciprofloxacin resistance. Two mismatch amplification mutation (MAMA) assays were developed and used to facilitate rapid detection ofgyrAandparCmutations. The isolates were also screened for plasmid-mediated quinolone resistance (PMQR) genes includingaac(6′)-Ib-cr, qepA, andqnr. Ciprofloxacin resistance (MICs4–≥32 μg/mL) was noted in 34 (37%) isolates, of which 33 isolates had multiple mutations either ingyrAalone(n=1)or in bothgyrAandparCregions(n=32).aac(6′)-Ib-crwas the most common PMQR gene detected in this study(n=61), followed byqnrBandqnrS(n=55and 1, resp.). Low-level ciprofloxacin resistance (MICs 1-2 μg/mL) was noted in 40 (43%) isolates carryingqnrBaccompanied by eitheraac(6′)-Ib-cr(n=34)or a singlegyrA83 mutation(n=6). Ciprofloxacin resistance was significantly associated with the presence of multiple mutations ingyrAandparCregions. While the isolates harbouringgyrAand/orparCalteration were distributed into 11 PFGE clusters, no specific clusters were associated with isolates carrying PMQR genes. The high prevalence of ciprofloxacin resistance amongst the Malaysian ESBL-producingK. pneumoniaeisolates suggests the need for more effective infection control measures to limit the spread of these resistant organisms in the hospital.

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