scholarly journals Molecular typing and profiling of topoisomerase mutations causing resistance to ciprofloxacin and levofloxacin inElizabethkingiaspecies

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5608 ◽  
Author(s):  
Ming-Jr Jian ◽  
Yun-Hsiang Cheng ◽  
Cherng-Lih Perng ◽  
Hung-Sheng Shang
Keyword(s):  
Random Amplified Polymorphic Dna ◽  
Tertiary Care ◽  
Resistance Mechanism ◽  
Gene Mutations ◽  
Resistance Mechanisms ◽  
Rapid Identification ◽  
Fluoroquinolone Resistance ◽  
Dilution Method ◽  
Single Mutation ◽  
Tertiary Care Centers

ObjectivesSeveralElizabethkingiaspecies often exhibit extensive antibiotic resistance, causing infections associated with severe morbidity and high mortality rates worldwide. In this study, we determined fluoroquinolone susceptibility profiles of clinicalElizabethkingiaspp. isolates and investigated the resistance mechanisms.MethodsIn 2017–2018, 131Elizabethkingiaspp. isolates were recovered from specimens collected at tertiary care centers in northern Taiwan. Initial species identification using the Vitek MS system and subsequent verification by 16S rRNA sequencing confirmed the presence ofElizabethkingia anophelis(n= 111),E. miricola(n= 11), andE. meningoseptica(n= 9). Fluoroquinolone susceptibility was determined using the microbroth dilution method, and fluoroquinolone resistance genes were analyzed by sequencing.ResultsAmongElizabethkingiaspp. isolates, 91% and 77% were resistant to ciprofloxacin and levofloxacin, respectively. The most prevalent alterations were two single mutations in GyrA, Ser83Ile, and Ser83Arg, detected in 76% of the isolates exhibiting fluoroquinolone MIC between 8 and 128 μg/ml. Another GyrA single mutation, Asp87Asn, was identified in two quinolone-resistantE. miricolastrains. None of the isolates had alterations in GyrB, ParC, or ParE. We developed a high-resolution melting assay for rapid identification of the prevalentgyrAgene mutations. The genetic relationship between the isolates was evaluated by random amplified polymorphic DNA PCR that yielded diverse pulsotypes, indicating the absence of any temporal or spatial overlap among the patients during hospitalization.ConclusionOur analysis of fluoroquinolone-resistantElizabethkingiaspp. isolates provides information for further research on the variations of the resistance mechanism and potential clinical guidance for infection management.

Sino-European Differences in the Genetic Landscape and Clinical Presentation of Pheochromocytoma and Paraganglioma

2020 ◽  
Vol 105 (10) ◽  
pp. 3295-3307 ◽  
Author(s):  
Jingjing Jiang ◽  
Jing Zhang ◽  
Yingxian Pang ◽  
Nicole Bechmann ◽  
Minghao Li ◽  
...  
Keyword(s):  
Paradigm Shift ◽  
Tertiary Care ◽  
Gene Mutations ◽  
Tumor Location ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
Genetic Landscape ◽  
Tertiary Care Centers ◽  
Almost All ◽  
Generation Sequencing

Abstract Context Pheochromocytomas and paragangliomas (PPGLs) are characterized by distinct genotype-phenotype relationships according to studies largely restricted to Caucasian populations. Objective To assess for possible differences in genetic landscapes and genotype-phenotype relationships of PPGLs in Chinese versus European populations. Design Cross-sectional study. Setting 2 tertiary-care centers in China and 9 in Europe. Participants Patients with pathologically confirmed diagnosis of PPGL, including 719 Chinese and 919 Europeans. Main Outcome Measures Next-generation sequencing performed in tumor specimens with mutations confirmed by Sanger sequencing and tested in peripheral blood if available. Frequencies of mutations were examined according to tumor location and catecholamine biochemical phenotypes. Results Among all patients, higher frequencies of HRAS, FGFR1, and EPAS1 mutations were observed in Chinese than Europeans, whereas the reverse was observed for NF1, VHL, RET, and SDHx. Among patients with apparently sporadic PPGLs, the most frequently mutated genes in Chinese were HRAS (16.5% [13.6-19.3] vs 9.8% [7.6-12.1]) and FGFR1 (9.8% [7.6-12.1] vs 2.2% [1.1-3.3]), whereas among Europeans the most frequently mutated genes were NF1 (15.9% [13.2-18.6] vs 6.6% [4.7-8.5]) and SDHx (10.7% [8.4–13.0] vs 4.2% [2.6–5.7]). Among Europeans, almost all paragangliomas lacked appreciable production of epinephrine and identified gene mutations were largely restricted to those leading to stabilization of hypoxia inducible factors. In contrast, among Chinese there was a larger proportion of epinephrine-producing paragangliomas, mostly due to HRAS and FGFR1 mutations. Conclusions This study establishes Sino-European differences in the genetic landscape and presentation of PPGLs, including ethnic differences in genotype-phenotype relationships indicating a paradigm shift in our understanding of the biology of these tumors.

scholarly journals Prevalence of Nontuberculous Mycobacteria among Extrapulmonary Tuberculosis Cases in Tertiary Care Centers in Northern India

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
A. K. Maurya ◽  
V. L. Nag ◽  
S. Kant ◽  
R. A. S. Kushwaha ◽  
M. Kumar ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Nontuberculous Mycobacteria ◽  
Extrapulmonary Tuberculosis ◽  
Tertiary Care ◽  
Rapid Identification ◽  
Northern India ◽  
Tertiary Care Centers ◽  
Tertiary Care Hospitals ◽  
Culture Positive ◽  
Final Confirmation

The reports of nontuberculous mycobacteria (NTM) associated with extrapulmonary diseases are increasing in tertiary care hospitals. Despite a significant increase in knowledge about NTM infections, they still represent a diagnostic and therapeutic challenge. The aim of this study is to know the prevalence of NTN among extrapulmonary tuberculosis cases in tertiary care centers in Northern India. A total of 227 culture positive isolates from 756 cases were tested for niacin production and catalase assay. BIO-LINE SD Ag MPT64 TB test and final identification and differentiation between MTBC and different species of NTM were further confirmed by GenoType Mycobacterium CM/AS assay. 71 cases (9.3%) were positive for AFB by ZN staining and 227 cases (30.1%) were positive for mycobacteria by culture. Niacin production and catalase activity were negative in 62/227 (27.4%) strains and after using a panel of different biochemicals and final confirmation by GenoType Mycobacterium CM assay. Out of 227 cultures tested, 165 (72.6%) strains were confirmed asM. tuberculosiscomplex, and 62 (27.4%) were confirmed as NTM. The most common NTM species identified wereM. fortuitum17 (27.5%) andM. intracellulare13 (20.9%). The rapid identification of NTM species may help in targeted therapy and management of the diseases.

scholarly journals Fluoroquinolone resistance of Staphylococcus epidermidis isolated from healthy conjunctiva and analysis of their mutations in quinolone-resistance determining region

2020 ◽  
Author(s):  
Jung Youb Kang ◽  
Woonhyung Lee ◽  
Bo Hyeon Jeong ◽  
Indal Park ◽  
Sang Joon Lee
Keyword(s):  
Staphylococcus Epidermidis ◽  
Point Mutations ◽  
Gene Mutations ◽  
Resistance Rate ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Dilution Method ◽  
Multiple Point ◽  
Positive Rate ◽  
Resistant Strains

Abstract Background: S. epidermidis is the most common pathogen in postoperative endophthalmitis and causes various infectious eye diseases. However, there is very little information on fluoroquinolone antibiotic resistance to S. epidermidis identified in conjunctival microbe and analysis of related genes. Here, the authors investigated the rate of resistance to fluoroquinolones of Staphylococcus epidermidis isolated from normal conjunctival microbes and mutations in the quinolone-resistance determining region (QRDR).Methods: 377 eye samples from 187 patients who underwent intravitreal injection and cataract surgery were included. Before the procedure, specimens were taken from the bilateral lower conjunctival sacs using a cotton swab and cultured. The cultures were identified and gyrA, gyrB, parC, and parE gene mutations of QRDR were confirmed by DNA extraction from resistant strains of S. epidermidis with a micro-dilution method using ciprofloxacin, levofloxacin, and moxifloxacin.Results: The culture positive rate was 61.8% (231) for 374 eye samples. Of the 303 total strains cultured, S. epidermidis was the most common with 33.7% (102). Ten types of gene mutations were observed in the resistant S. epidermidis of 21 strains. One-point mutation was observed mainly in gyrA and parC, and a small number of mutations were observed in parE in the form of a double point mutations. When there were multiple point mutations in both gyrA and parC, the highest minimum inhibitory concentration (MIC) was observed.Conclusions: The quinolone resistance rate of S. epidermidis increased in comparison with previous studies, and resistant S. epidermidis showed mostly QRDR mutations, which were mainly found in gyrA and parC, and showed strong resistance when mutated in both genes.

Overexpression of SmeGH contributes to the acquired MDR of Stenotrophomonas maltophilia

2019 ◽  
Vol 74 (8) ◽  
pp. 2225-2229 ◽  
Author(s):  
Li-Hua Li ◽  
Man-San Zhang ◽  
Chao-Jung Wu ◽  
Yi-Tsung Lin ◽  
Tsuey-Ching Yang
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Treatment Options ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Fluoroquinolone Resistance ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Real Time Quantitative Pcr ◽  
Resistant Mutants ◽  
High Level

Abstract Background Stenotrophomonas maltophilia displays high-level resistance to various antibiotics. Fluoroquinolone is among the few treatment options for S. maltophilia infection. Overexpression of SmeDEF, SmeVWX and SmQnr are the main mechanisms responsible for fluoroquinolone resistance in S. maltophilia. Objectives To reveal the unidentified fluoroquinolone resistance mechanisms in S. maltophilia. Methods Fluoroquinolone-resistant spontaneous mutants were selected by spreading KJΔDEFΔ5, a SmeDEF- and SmeVWX-null double mutant, on ciprofloxacin- or levofloxacin-containing medium. Antibiotic susceptibility was assessed by the agar dilution method. Outer membrane protein profiles of fluoroquinolone-resistant mutants were assayed by SDS-PAGE and significant protein was characterized by LC-MS/MS. The expression of tolCsm, smeH, smeK, smeN, smeP, smeZ and smQnr was investigated by real-time quantitative PCR. The contribution of SmeGH overexpression to antibiotic resistance was verified by ΔsmeH mutant construction and smeGH complementation assay. Results Most fluoroquinolone-resistant mutants displayed MDR. The TolCsm protein and smeH transcript were concomitantly overexpressed in some MDR mutants. smeH deletion increased the susceptibility of the MDR mutants to fluoroquinolone, macrolide, chloramphenicol and tetracycline, and the resistance compromise was partially reversed by complementation with a plasmid containing smeGH. SmeGH overexpression was found in some fluoroquinolone-resistant clinical S. maltophilia isolates whose SmeDEF, SmeVWX and SmQnr proteins were not or were lowly expressed. Conclusions Overexpression of SmeGH contributes to the acquired resistance of S. maltophilia to fluoroquinolone, macrolide, chloramphenicol and tetracycline.

scholarly journals Fluoroquinolone resistance of Staphylococcus epidermidis isolated from healthy conjunctiva and analysis of their mutations in quinolone-resistance determining region

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Jung Youb Kang ◽  
Woonhyoung Lee ◽  
Gwang Myeong Noh ◽  
Bo Hyun Jeong ◽  
Indal Park ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Point Mutations ◽  
Gene Mutations ◽  
Resistance Rate ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Dilution Method ◽  
Multiple Point ◽  
Positive Rate ◽  
Resistant Strains

Abstract Background Staphylococcus epidermidis is the most common pathogen in postoperative endophthalmitis and causes various infectious eye diseases. However, there is very little information on fluoroquinolone antibiotic resistance to S. epidermidis identified in conjunctival microbe and analysis of related genes. Here, the authors investigated the rate of resistance to fluoroquinolones of Staphylococcus epidermidis isolated from normal conjunctival microbes and mutations in the quinolone-resistance determining region (QRDR). Methods 377 eye samples from 187 patients who underwent intravitreal injection and cataract surgery were included. Specimens were taken from the bilateral lower conjunctival sacs using a cotton swab and cultured. The cultures were identified using MALDI-TOP MS and gyrA, gyrB, parC, and parE gene mutations of QRDR were confirmed by DNA extraction from resistant strains of S. epidermidis with a micro-dilution method using ciprofloxacin, levofloxacin, and moxifloxacin. Results The culture positive rate was 61.8% (231) for 374 eye samples. Of the 303 total strains cultured, S. epidermidis was the most common with 33.7% (102). Ten types of gene mutations were observed in the resistant S. epidermidis of 21 strains. One-point mutation was observed mainly in gyrA and parC, and a small number of mutations were observed in parE in the form of a double point mutations. When there were multiple point mutations in both gyrA and parC, the highest minimum inhibitory concentration was observed. Conclusions The quinolone resistance rate of S. epidermidis increased in comparison with previous studies, and resistant S. epidermidis showed mostly QRDR mutations, which were mainly found in gyrA and parC, and showed strong resistance when mutated in both genes.

scholarly journals Fluoroquinolone resistance of Staphylococcus epidermidis isolated from healthy conjunctiva and analysis of their mutations in quinolone-resistance determining region

2020 ◽  
Author(s):  
Jung Youb Kang ◽  
Woonhyoung Lee ◽  
Gwang Myeong Noh ◽  
Bo Hyun Jeong ◽  
Indal Park ◽  
...  
Keyword(s):  
Staphylococcus Epidermidis ◽  
Point Mutations ◽  
Gene Mutations ◽  
Resistance Rate ◽  
Quinolone Resistance ◽  
Fluoroquinolone Resistance ◽  
Dilution Method ◽  
Multiple Point ◽  
Positive Rate ◽  
Resistant Strains

Abstract Background: S. epidermidis is the most common pathogen in postoperative endophthalmitis and causes various infectious eye diseases. However, there is very little information on fluoroquinolone antibiotic resistance to S. epidermidis identified in conjunctival microbe and analysis of related genes. Here, the authors investigated the rate of resistance to fluoroquinolones of Staphylococcus epidermidis isolated from normal conjunctival microbes and mutations in the quinolone-resistance determining region (QRDR).Methods: 377 eye samples from 187 patients who underwent intravitreal injection and cataract surgery were included. Specimens were taken from the bilateral lower conjunctival sacs using a cotton swab and cultured. The cultures were identified using MALDI-TOP MS and gyrA, gyrB, parC, and parE gene mutations of QRDR were confirmed by DNA extraction from resistant strains of S. epidermidis with a micro-dilution method using ciprofloxacin, levofloxacin, and moxifloxacin.Results: The culture positive rate was 61.8% (231) for 374 eye samples. Of the 303 total strains cultured, S. epidermidis was the most common with 33.7% (102). Ten types of gene mutations were observed in the resistant S. epidermidis of 21 strains. One-point mutation was observed mainly in gyrA and parC, and a small number of mutations were observed in parE in the form of a double point mutations. When there were multiple point mutations in both gyrA and parC, the highest minimum inhibitory concentration (MIC) was observed.Conclusions: The quinolone resistance rate of S. epidermidis increased in comparison with previous studies, and resistant S. epidermidis showed mostly QRDR mutations, which were mainly found in gyrA and parC, and showed strong resistance when mutated in both genes.

scholarly journals The Correlation of Cystic Fibrosis Mutations and Dental Caries in A Tertiary Care Center

2021 ◽  
pp. 1-4
Author(s):  
Hanaa Banjar ◽  
Reem Ghomraoui
Keyword(s):  
Cystic Fibrosis ◽  
Dental Caries ◽  
Care Center ◽  
Tertiary Care ◽  
Gene Mutations ◽  
Common Mutation ◽  
Single Mutation ◽  
Tertiary Care Center ◽  
Group 2 ◽  
Group 1

Introduction: Previous data showed that dental caries is common in the Saudi general population as well as in the Cystic fibrosis patients. Objectives: to identify the correlation of dental caries severity with cystic fibrosis (CFTR) gene mutations in a tertiary care center Methodology: Retrospective cohort study through reviewing medical files for cystic fibrosis patients who had dental assessment during the period January 1998 to December 2018. Results: A total of 56 patients in group 1 (less than 12 years of age) and 55 patients for group 2 (more than 12 years of age). The score for dental caries (decay, missing and filled teeth) dmft/DMFT were 4.85 (4.6) for group 1 and 5.94 (4.27) for group 2. There were 3 common mutations in both groups namely in c.3700A>G, c.1418delG and c.1911delG. There is another common mutation in group 1 located in c.579+1G>T. Additionally, group 2 has another 3 common mutations that included c.416A>T, c.3909C>G, and c.1647T>G. Almost 95 % of mutations are in homozygous state in both groups. There was no single mutation that favors deterioration in DFMT score. Almost all mutations have similar scores, but certainly, group 2 has worse DFMT compared to group 1. There was no difference in dmft/DMFT scores between homozygous and heterozygous CFTR in both groups. Conclusion: No identified mutation that correlates with worsening in dental caries scores. There was no difference in dental caries’ scores between homozygous and heterozygous CFTR in both pediatric and adult groups

scholarly journals Activity of cefepime/zidebactam against MDR Escherichia coli isolates harbouring a novel mechanism of resistance based on four-amino-acid inserts in PBP3

2020 ◽  
Vol 75 (12) ◽  
pp. 3563-3567 ◽  
Author(s):  
Sachin S Bhagwat ◽  
Periasamy Hariharan ◽  
Prashant R Joshi ◽  
Snehal R Palwe ◽  
Rahul Shrivastava ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Tertiary Care ◽  
Resistance Mechanism ◽  
Resistance Mechanisms ◽  
Care Hospital ◽  
E Coli ◽  
Microdilution Method ◽  
Broth Microdilution Method

Abstract Background Recent reports reveal the emergence of Escherichia coli isolates harbouring a novel resistance mechanism based on four-amino-acid inserts in PBP3. These organisms concomitantly expressed ESBLs or/and serine-/metallo-carbapenemases and were phenotypically detected by elevated aztreonam/avibactam MICs. Objectives The in vitro activities of the investigational antibiotic cefepime/zidebactam and approved antibiotics (ceftazidime/avibactam, ceftolozane/tazobactam, imipenem/relebactam and others) were determined against E. coli isolates harbouring four-amino-acid inserts in PBP3. Methods Whole-genome sequenced E. coli isolates (n = 89) collected from a large tertiary care hospital in Southern India (n = 64) and from 12 tertiary care hospitals located across India (n = 25) during 2016–18, showing aztreonam/avibactam MICs ≥1 mg/L (≥4 times the aztreonam epidemiological cut-off) were included in this study. The MICs of antibiotics were determined using the reference broth microdilution method. Results Four-amino-acid inserts [YRIK (n = 30) and YRIN (n = 53)] were found in 83/89 isolates. Among 83 isolates, 65 carried carbapenemase genes [blaNDM (n = 39), blaOXA-48-like (n = 11) and blaNDM + blaOXA-48-like (n = 15)] and 18 isolates produced ESBLs/class C β-lactamases only. At least 16 unique STs were noted. Cefepime/zidebactam demonstrated potent activity, with all isolates inhibited at ≤1 mg/L. Comparator antibiotics including ceftazidime/avibactam and imipenem/relebactam showed limited activities. Conclusions E. coli isolates concurrently harbouring four-amino-acid inserts in PBP3 and NDM are an emerging therapeutic challenge. Assisted by the PBP2-binding action of zidebactam, the cefepime/zidebactam combination overcomes both target modification (PBP3 insert)- and carbapenemase (NDM)-mediated resistance mechanisms in E. coli.

Emerging Antimicrobial Resistance Among Methicillin Resistant Staphylococcus Aureus (MRSA) in a Tertiary Care Centre in North India

JMS SKIMS ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 48-49
Author(s):  
Javaid Ahmad Bhat ◽  
Shariq Rashid Masoodi
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Resistance ◽  
Tertiary Care ◽  
Resistance Mechanisms ◽  
North India ◽  
Global Public Health ◽  
Care Centre ◽  
Tertiary Care Centre ◽  
Effective Prevention ◽  
Mupirocin Resistance

Apropos to the article by Dr Bali, titled “Mupirocin resistance in clinical isolates of methicillin-sensitive and resistant Staphylococcus aureus in a tertiary care centre of North India” (1), the authors have raised important issue of emerging antimicrobial resistance (AMR). Antimicrobial resistance is an increasingly serious threat to global public health that requires action across all government sectors and society. As per WHO, AMR lurks the effective prevention and management of an ever-increasing spectrum of infections caused by bacteria, parasites, fungi and viruses. Novel resistance mechanisms are emerging and spreading globally, threatening the man’s ability to treat common infectious diseases.

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