scholarly journals Functional Identification and Evolutionary Analysis of Two Novel Plasmids Mediating Quinolone Resistance in Proteus vulgaris

2020 ◽  
Vol 8 (7) ◽  
pp. 1074 ◽  
Author(s):  
Hongyang Zhang ◽  
Mingding Chang ◽  
Xiaochen Zhang ◽  
Peiyan Cai ◽  
Yixin Dai ◽  
...  

Plasmid-mediated quinolone resistance (PMQR) remains one of the main mechanisms of bacterial quinolone resistance and plays an important role in the transmission of antibiotic resistance genes (ARGs). In this study, two novel plasmids, p3M-2A and p3M-2B, which mediate quinolone resistance in Proteus vulgaris strain 3M (P3M) were identified. Of these, only p3M-2B appeared to be a qnrD-carrying plasmid. Both p3M-2A and p3M-2B could be transferred into Escherichia coli, and the latter caused a twofold change in ciprofloxacin resistance, according to the measured minimum inhibitory concentration (MIC). Plasmid curing/complementation and qRT-PCR results showed that p3M-2A can directly regulate the expression of qnrD in p3M-2B under treatment with ciprofloxacin, in which process, ORF1 was found to play an important role. Sequence alignments and phylogenetic analysis revealed the evolutionary relationships of all reported qnrD-carrying plasmids and showed that ORF1–4 in p3M-2B is the most conserved backbone for the normal function of qnrD-carrying plasmids. The identified direct repeats (DR) suggested that, from an evolutionary perspective, p3M-2B may have originated from the 2683-bp qnrD-carrying plasmid and may increase the possibility of plasmid recombination and then of qnrD transfer. To the best of our knowledge, this is the first identification of a novel qnrD-carrying plasmid isolated from a P. vulgaris strain of shrimp origin and a plasmid that plays a regulatory role in qnrD expression. This study also sheds new light on plasmid evolution and on the mechanism of horizontal transfer of ARGs encoded by plasmids.

2021 ◽  
Author(s):  
Farhan Yusuf ◽  
Kimberley Gilbride

Bacterial isolates found in aquatic ecosystems often carry antibiotic resistance genes (ARGs). These ARGs are often found on plasmids and transposons, which allows them to be proliferate throughout bacterial communities via horizontal gene transfer (HGT) causing dissemination of multidrug resistance. The increase in antibiotic resistance has raised concerns about the ability to continue to use these drugs to fight infectious diseases. Novel synthetic antibiotics like ciprofloxacin that are not naturally found in the environment were developed to prevent resistances. However, ciprofloxacin resistance has occurred through chromosomal gene mutations of type 2 topoisomerases or by the acquisition of plasmid-mediated quinolone resistances (PMQR). A particular PMQR, qnr genes, encoding for pentapeptide repeat proteins that confer low levels of quinolone resistance and protect DNA gyrase and topoisomerase IV from antibacterial activity. These qnr genes have been identified globally in both clinical and environmental isolates. The aim of this study was to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in the Greater Toronto Area and the potential dissemination of ciprofloxacin resistance. With the selective pressure of ciprofloxacin, we hypothesize that ciprofloxacin-resistant bacteria (CipR) in the environment may carry PMQR mechanisms while the sensitive population (CipS) would not carry PMQR genes. Isolates were tested for resistance to an additional 12 different antibiotics and identified using Sanger sequencing PCR products of the 16S rRNA gene. To determine which genes are responsible for ciprofloxacin resistance, multiplex PCR of associated qnr genes, qnrA, qnrB, and qnrS, was carried out on 202 environmental isolates. Our data demonstrate a similar prevalence of qnr genes was found in CipR (19%) and CipS (14%) populations suggesting that the presence of these genes was not necessarily correlated with the phenotypic resistance to the antibiotic. Furthermore, ciprofloxacinresistant bacteria were found in all locations at similar frequencies suggesting that resistance genes are widespread and could possibly arise through HGT events. Overall, determining the underlying cause and prevalence of ciprofloxacin resistance could help re-establish the effectiveness of these antimicrobial compounds.


2021 ◽  
Author(s):  
Farhan Yusuf ◽  
Kimberley Gilbride

Bacterial isolates found in aquatic ecosystems often carry antibiotic resistance genes (ARGs). These ARGs are often found on plasmids and transposons, which allows them to be proliferate throughout bacterial communities via horizontal gene transfer (HGT) causing dissemination of multidrug resistance. The increase in antibiotic resistance has raised concerns about the ability to continue to use these drugs to fight infectious diseases. Novel synthetic antibiotics like ciprofloxacin that are not naturally found in the environment were developed to prevent resistances. However, ciprofloxacin resistance has occurred through chromosomal gene mutations of type 2 topoisomerases or by the acquisition of plasmid-mediated quinolone resistances (PMQR). A particular PMQR, qnr genes, encoding for pentapeptide repeat proteins that confer low levels of quinolone resistance and protect DNA gyrase and topoisomerase IV from antibacterial activity. These qnr genes have been identified globally in both clinical and environmental isolates. The aim of this study was to determine the prevalence of ciprofloxacin-resistant bacteria in aquatic environments in the Greater Toronto Area and the potential dissemination of ciprofloxacin resistance. With the selective pressure of ciprofloxacin, we hypothesize that ciprofloxacin-resistant bacteria (CipR) in the environment may carry PMQR mechanisms while the sensitive population (CipS) would not carry PMQR genes. Isolates were tested for resistance to an additional 12 different antibiotics and identified using Sanger sequencing PCR products of the 16S rRNA gene. To determine which genes are responsible for ciprofloxacin resistance, multiplex PCR of associated qnr genes, qnrA, qnrB, and qnrS, was carried out on 202 environmental isolates. Our data demonstrate a similar prevalence of qnr genes was found in CipR (19%) and CipS (14%) populations suggesting that the presence of these genes was not necessarily correlated with the phenotypic resistance to the antibiotic. Furthermore, ciprofloxacinresistant bacteria were found in all locations at similar frequencies suggesting that resistance genes are widespread and could possibly arise through HGT events. Overall, determining the underlying cause and prevalence of ciprofloxacin resistance could help re-establish the effectiveness of these antimicrobial compounds.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jieun Kim ◽  
Kye-Yeung Park ◽  
Hoon-Ki Park ◽  
Hwan-Sik Hwang ◽  
Mi-Ran Seo ◽  
...  

AbstractTo characterize the carriage of antibiotic resistance genes (ARGs) in the gut microbiome of healthy individuals. Fecal carriage of ARGs was investigated in 61 healthy individuals aged 30 to 59 years through whole metagenome sequencing of the gut microbiome and a targeted metagenomic approach. The number of ARGs in the gut microbiome was counted and normalized per million predicted genes (GPM). In the Korean population, the resistome ranged from 49.7 to 292.5 GPM (median 89.7). Based on the abundance of ARGs, the subjects were categorised into high (> 120 GPM), middle (60‒120 GPM), and low (< 60 GPM) ARG groups. Individuals in the high ARG group tended to visit hospitals more often (P = 0.065), particularly for upper respiratory tract infections (P = 0.066), and carried more blaCTX-M (P = 0.008). The targeted metagenome approach for bla and plasmid-mediated quinolone resistance (PMQR) genes revealed a high fecal carriage rate; 23% or 13.1% of the subjects carried blaCTX-M or blaCMY-2, respectively. Regarding PMQR genes, 59% of the subjects carried PMQR, and 83% of them harboured 2‒4 PMQR genes (qnrB 44.3%, qnrS 47.5% etc.). The presence of blaCTX-M correlated with ARG abundance in the gut resistome, whereas PMQR genes were irrelevant to other ARGs (P = 0.176). Fecal carriage of blaCTX-M and PMQR genes was broad and multiplexed among healthy individuals.


2021 ◽  
Author(s):  
Jay Wook Joong Kim ◽  
Vincent Blay ◽  
Portia Mira ◽  
Miriam Barlow ◽  
Manel Camps

Fluoroquinolones are one of the most widely used class of antibiotics. They target two type II topoisomerase enzymes: gyrase and topoisomerase IV. Resistance to these drugs, which is largely caused by mutations in their target enzymes, is on the rise and becoming a serious public health risk. In this work, we analyze the sequences of 352 extraintestinal E. coli clinical isolates to gain insights into the selective pressures shaping the type II topoisomerase mutation landscape in E. coli. We identify both Quinolone Resistance-Determining Region (QRDR) and non-QRDR mutations, outline their mutation trajectories, and show that they are likely driven by different selective pressures. We confirm that ciprofloxacin resistance is specifically and strongly associated with QRDR mutations. By contrast, non-QRDR mutations are associated with the presence of the chromosomal version of ccdAB, a toxin-antitoxin operon, where the toxin CcdB is known to target gyrase. We also find that ccdAB and the evolution of QRDR mutation trajectories are partially incompatible. Finally, we identify partial deletions in CcdB and additional mutations that likely facilitate the compatibility between the presence of the ccdAB operon and QRDR mutations. These "permissive" mutations are all found in ParC (a topoisomerase IV subunit). This, and the fact that CcdB-selected mutations frequently map to topoisomerase IV, strongly suggests that this enzyme (in addition to gyrase) is likely a target for the toxin CcdB in E. coli, although an indirect effect on global supercoiling cannot be excluded. This work opens the door for the use of the presence of ccdB and of the proposed permissive mutations in the genome as genetic markers to assess the risk of quinolone resistance evolution and implies that certain strains may be genetically more refractory to evolving quinolone resistance through mutations in target enzymes.


ANKEM Dergisi ◽  
2021 ◽  
Author(s):  
Nilüfer Uzunbayır Akel ◽  
Yamaç Tekintaş ◽  
Fethiye Ferda Yılmaz ◽  
İsmail Öztürk ◽  
Mustafa Ökeer ◽  
...  

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Huang ◽  
James O. Ogutu ◽  
Jiarui Gu ◽  
Fengshu Ding ◽  
Yuhong You ◽  
...  

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.


2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Yan Zhao ◽  
Wenkai Niu ◽  
Yanxia Sun ◽  
Huaijie Hao ◽  
Dong Yu ◽  
...  

AnS. maltophiliastrain named WJ66 was isolated from a patient; WJ66 showed resistance to more antibiotics than the otherS. maltophiliastrains. This bacteraemia is resistant to sulphonamides, or fluoroquinolones, while the representative strain ofS. maltophilia, K279a, is sensitive to both. To explore drug resistance determinants of this strain, the draft genome sequence of WJ66 was determined and compared to otherS. maltophiliasequences. Genome sequencing and genome-wide evolutionary analysis revealed that WJ66 was highly homologous with the strain K279a, but strain WJ66 contained additional antibiotic resistance genes. Further analysis confirmed that strain WJ66 contained an amino acid substitution (Q83L) in fluoroquinolone target GyrA and carried a class 1 integron, with anaadA2gene in the resistance gene cassette. Homology analysis from the pathogen-host interaction database showed that strain WJ66 lacks raxST and raxA, which is consistent with K279a. Comparative genomic analyses revealed that subtle nucleotide differences contribute to various significant phenotypes in close genetic relationship strains.


2015 ◽  
Author(s):  
Xiaolong Wang ◽  
Chao Yang

Multiple sequence alignment (MSA) is widely used to reveal structural and functional changes leading to genetic differences among species, and to reconstruct evolutionary histories of related genes, proteins and genomes. Traditionally, proteins and their coding sequences (CDSs) are aligned and analyzed separately, but often drastically different conclusions were drawn on a same set of data. Here we present a new alignment strategy, Codon and Amino Acid Unified Sequence Alignment (CAUSA) 2.0, which aligns proteins and their coding sequences simultaneously. CAUSA 2.0 optimizes the alignment of CDSs at both codon and amino acid level efficiently. Theoretical analysis showed that CAUSA 2.0 enhances the entropy information content of MSA. Empirical data analysis demonstrated that CAUSA 2.0 is more accurate and consistent than nucleotide, protein or codon level alignments. CAUSA 2.0 locates in-frame indels more accurately, makes the alignment of coding sequences biologically more significant, and reveals several novel mutation mechanisms that relate to some genetic diseases. CAUSA 2.0 is available in website www.DNAPlusPro.com .


Pharmacia ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 1-7
Author(s):  
Hawraa Mohammed Al-Rafyai ◽  
Mourouge Saadi Alwash ◽  
Noor Salman Al-Khafaji

Aquatic environment contamination remains a foremost global public health hazards, and symbolizes a significant reservoir of releasing antibiotic resistant bacteria. The survival of Escherichia coli in aquatic environments serves as a potential reservoir of antibiotic resistance, encompassing but not restricted to a plasmid-mediated quinolone resistance (PMQR) mechanism. The current study aimed to detect the presence of the PMQR-qnrA gene in quinolone-resistant E. coli isolates. Sixty-one waterborne E. coli with known phylogroups/subgroups isolated from the Al-Hillah River in Babylon Province, Iraq, were screened for the phenotypic resistance to third-generation quinolones (levofloxacin and ofloxacin) and were further analysed for the presence of the qnrA gene using polymerase chain reaction (PCR). Fifty-seven (93.4%) of 61 E. coli isolates were levofloxacin-resistant, and 55 (90.2%) were ofloxacin-resistant. Among the 57 quinolone-resistant E. coli, 40 (65.57%) isolates were found to carry the PMQR-qnrA gene. Among the 40 qnrA-positive E. coli, 22 (36.1%) isolates were in phylogroup B2, followed by 8 (13.1%) isolates in phylogroup D, 6 (9.8%) isolates in phylogroup B1, and 4 (6.6%) isolates in phylogroup A. The presence of the PMQR-qnrA gene in E. coli belonging to phylogroup B2 and D reflects the need for routine monitoring of antibiotic resistance genes (ARGs) in the Al-Hillah River.


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