scholarly journals Prevalence of Aminoglycoside Resistance Genes and Molecular Characterization of a Novel Gene, aac(3)-IIg, among Clinical Isolates of the Enterobacter cloacae Complex from a Chinese Teaching Hospital

2020 ◽  
Vol 64 (9) ◽  
Author(s):  
Xinyi Zhu ◽  
Peizhen Li ◽  
Changrui Qian ◽  
Hongmao Liu ◽  
Hailong Lin ◽  
...  
Keyword(s):  
Teaching Hospital ◽  
Resistance Genes ◽  
High Throughput Sequencing ◽  
Enterobacter Cloacae ◽  
Human Pathogens ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Content Type ◽  
Novel Gene ◽  
Aminoglycoside Resistance Genes

ABSTRACT Members of the Enterobacter cloacae complex are important opportunistic human pathogens capable of causing a wide variety of infections. During recent decades, aminoglycoside-resistant E. cloacae complex isolates have increasingly been reported and have become a major concern. Here, we employed high-throughput sequencing in combination with specific PCR assays to investigate the prevalence of aminoglycoside resistance genes among 170 isolates of the E. cloacae complex collected from a teaching hospital in Wenzhou, China. A total of 12 known genes [aphA-1, strA, strB, aac(6′)-IIc, aadA2, aac(3)-IId, aadB, aadA1, rmtB, armA, aadA5, and aac(6′)-Ie–aph(2′')-Ia] and 1 novel gene [aac(3)-IIg] were identified, with aphA-1 (71.18%), strA (55.29%), and strB (52.35%) being the most prevalent, and aac(3)-IIg was detected with a positive rate of 21.76% (37/170). The aac(3)-IIg gene was 810 bp in length and encoded a protein that shared 72 to 78% identities with previously known AAC(3)-II aminoglycoside 3-N-acetyltransferases. The MICs of gentamicin and tobramycin were 512 μg/ml and 64 μg/ml, respectively, when aac(3)-IIg was cloned into Escherichia coli DH5α. All aac(3)-IIg-positive isolates exerted broad aminoglycoside resistance profiles, mediated by the coexistence of multiple resistance genes. Moreover, aminoglycoside resistance and resistance genes were found to be transferable in most strains (24/37). Nevertheless, pulsed-field gel electrophoresis (PFGE) and dendrogram analysis showed clonal diversity among these isolates. S1 nuclease PFGE, Southern hybridization, and whole-genome sequencing indicated that aac(3)-IIg was located on transferable as well as nontransferable plasmids of various sizes. The analysis of the genetic environment suggested that aac(3)-IIg is embedded within a class 1 integron, with IS26 playing an important role in its mobility.

scholarly journals In99, an In100-related integron, its occurrence and prevalence in clinical Pseudomonas aeruginosa strains from a central region of Portugal

2006 ◽  
Vol 135 (3) ◽  
pp. 502-504 ◽  
Author(s):  
T. CAETANO ◽  
S. FERREIRA ◽  
A. P. MONDEGO ◽  
A. CORREIA ◽  
S. MENDO
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Resistance Genes ◽  
Central Region ◽  
Clinical Isolates ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Class 1 ◽  
Aminoglycoside Resistance Genes

In99, a possible ancestor of In100, is a class 1 integron associated with carbenicillinase (blaPSE) and aminoglycoside resistance genes [aac(6′)-Ib and aadA2]. In99 was present in 8 of 81 clinical isolates of Pseudomonas aeruginosa from unrelated patients collected in different years. The strains fell into two clonal groups and exhibited resistance to β-lactams and aminoglycosides.

scholarly journals New Determinants of Aminoglycoside Resistance and Their Association with the Class 1 Integron Gene Cassettes in Trueperella pyogenes

2020 ◽  
Vol 21 (12) ◽  
pp. 4230
Author(s):  
Ewelina Kwiecień ◽  
Ilona Stefańska ◽  
Dorota Chrobak-Chmiel ◽  
Agnieszka Sałamaszyńska-Guz ◽  
Magdalena Rzewuska
Keyword(s):  
Resistance Genes ◽  
Resistance Mechanisms ◽  
Aminoglycoside Resistance ◽  
Class 1 Integron ◽  
Gene Cassettes ◽  
Genetic Elements ◽  
Trueperella Pyogenes ◽  
Broth Microdilution Method ◽  
Class 1 ◽  
Aminoglycoside Resistance Genes

Trueperella pyogenes is an important opportunistic animal pathogen. Different antimicrobials, including aminoglycosides, are used to treat T. pyogenes infections. The aim of the present study was to evaluate aminoglycoside susceptibility and to detect aminoglycoside resistance determinants in 86 T. pyogenes isolates of different origin. Minimum inhibitory concentration of gentamicin, streptomycin, and kanamycin was determined using a standard broth microdilution method. Genetic elements associated with aminoglycoside resistance were investigated by PCR and DNA sequencing. All studied isolates were susceptible to gentamicin, but 32.6% and 11.6% of them were classified as resistant to streptomycin and kanamycin, respectively. A total of 30 (34.9%) isolates contained class 1 integrons. Class 1 integron gene cassettes carrying aminoglycoside resistance genes, aadA11 and aadA9, were found in seven and two isolates, respectively. Additionally, the aadA9 gene found in six isolates was not associated with mobile genetic elements. Moreover, other, not carried by gene cassettes, aminoglycoside resistance genes, strA-strB and aph(3’)-IIIa, were also detected. Most importantly, this is the first description of all reported genes in T. pyogenes. Nevertheless, the relevance of the resistance phenotype to genotype was not perfectly matched in 14 isolates. Therefore, further investigations are needed to fully explain aminoglycoside resistance mechanisms in T. pyogenes.

scholarly journals Molecular Epidemiology of Emerging bla OXA-23-Like - and bla OXA-24-Like -Carrying Acinetobacter baumannii in Taiwan

2018 ◽  
Vol 62 (3) ◽  
Author(s):  
Shu-Chen Kuo ◽  
Wei-Cheng Huang ◽  
Tzu-Wen Huang ◽  
Hui-Ying Wang ◽  
Jui-Fen Lai ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Aminoglycoside Resistance ◽  
S1 Nuclease ◽  
Content Type ◽  
Class A ◽  
Carbapenem Resistant ◽  
Aminoglycoside Resistance Genes ◽  
Resistance Island

ABSTRACT The rate of recovery of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates has increased significantly in recent decades in Taiwan. This study investigated the molecular epidemiology of CRAB with a focus on the mechanisms of resistance and spread in isolates with bla OXA-23-like or bla OXA-24-like . All 555 CRAB isolates in our multicenter collection, which were recovered from 2002 to 2010, were tested for the presence of class A, B, and D carbapenemase genes. All isolates with bla OXA-23-like or bla OXA-24-like were subjected to pulsed-field gel electrophoresis, and 82 isolates (60 isolates with bla OXA-23-like and 22 isolates with bla OXA-24-like ) were selected for multilocus sequence typing to determine the sequence type (ST) and clonal group (CG) and for detection of additional β-lactamase and aminoglycoside resistance genes. The flanking regions of carbapenem and aminoglycoside resistance genes were identified by PCR mapping and sequencing. The localization of bla OXA was determined by S1 nuclease and I-CeuI assays. The numbers of CRAB isolates carrying bla OXA-23-like or bla OXA-24-like , especially those carrying bla OXA-23-like , increased significantly from 2008 onward. The bla OXA-23-like gene was carried by antibiotic resistance genomic island 1 (AbGRI1)-type structures located on plasmids and/or the chromosome in isolates of different STs (CG92 and novel CG786), whereas bla OXA-24-like was carried on plasmids in CRAB isolates of limited STs (CG92). No class A or B carbapenemase genes were identified. Multiple aminoglycoside resistance genes coexisted in CRAB. Tn 6180 -borne armA was found in 74 (90.2%) CRAB isolates, and 58 (70.7%) isolates had Tn 6179 upstream, constituting AbGRI3. bla TEM was present in 38 (46.3%) of the CRAB isolates tested, with 35 (92.1%) isolates containing bla TEM in AbGRI2-type structures, and 61% of ampC genes had IS Aba1 upstream. We conclude that the dissemination and spread of a few dominant lineages of CRAB containing various resistance island structures occurred in Taiwan.

scholarly journals Genomic Insights into Colistin-Resistant Klebsiella pneumoniae from a Tunisian Teaching Hospital

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Nadia Jaidane ◽  
Rémy A. Bonnin ◽  
Wejdene Mansour ◽  
Delphine Girlich ◽  
Elodie Creton ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Teaching Hospital ◽  
Resistance Genes ◽  
Transmembrane Protein ◽  
Health Concern ◽  
Colistin Resistance ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
A Genome

ABSTRACT The emergence of colistin-resistant Klebsiella pneumoniae (CoRKp) is a public health concern, since this antibiotic has become the last line of treatment for infections caused by multidrug-resistant (MDR) Gram negatives. In this study, we have investigated the molecular basis of colistin resistance in 13 MDR K. pneumoniae strains isolated from 12 patients in a teaching hospital in Sousse, Tunisia. Whole-genome sequencing (WGS) was used to decipher the molecular mechanism of colistin resistance and to identify the resistome of these CoRKp isolates. It revealed a genome of ca. 5.5 Mbp in size with a G+C content of 57%, corresponding to that commonly observed for K. pneumoniae. These isolates belonged to the 5 different sequence types (ST11, ST15, ST101, ST147, and ST392), and their resistome was composed of acquired β-lactamases, including extended-spectrum beta-lactamase and carbapenemase genes (bla CTX-M-15, bla OXA-204, bla OXA-48, and bla NDM-1 genes), aminoglycoside resistance genes [aac(6′)Ib-cr, aph(3″)-Ib, aph(6)-Id, and aac(3)-IIa], and fosfomycin (fosA), fluoroquinolone (qnr-like), chloramphenicol, trimethoprim, and tetracycline resistance genes. All of the isolates were identified as having a mutated mgrB gene. Mapping reads with reference sequences of the most common genes involved in colistin resistance revealed several modifications in mgrB, pmr, and pho operons (deletions, insertions, and substitutions) likely affecting the function of these proteins. It is worth noting that among the 12 patients, 10 were treated with colistin before the isolation of CoRKp. No plasmid encoding mcr-1 to mcr-5 genes was found in these isolates. This study corresponds to the first molecular characterization of a collection of CoRKp strains in Tunisia and highlights that the small-transmembrane protein MgrB is a main mechanism for colistin resistance in K. pneumoniae.

scholarly journals Identification of a Novel Genomic Island Conferring Resistance to Multiple Aminoglycoside Antibiotics in Campylobacter coli

2012 ◽  
Vol 56 (10) ◽  
pp. 5332-5339 ◽  
Author(s):  
Shangshang Qin ◽  
Yang Wang ◽  
Qijing Zhang ◽  
Xia Chen ◽  
Zhangqi Shen ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Broiler Chickens ◽  
Genomic Island ◽  
Aminoglycoside Antibiotics ◽  
Campylobacter Coli ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Pcr Screening ◽  
High Prevalence ◽  
Aminoglycoside Resistance Genes

ABSTRACTHistorically, the incidence of gentamicin resistance inCampylobacterhas been very low, but recent studies reported a high prevalence of gentamicin-resistantCampylobacterisolated from food-producing animals in China. The reason for the high prevalence was unknown and was addressed in this study. PCR screening identified aminoglycoside resistance genesaphA-3andaphA-7and theaadE–sat4–aphA-3cluster among 41Campylobacterisolates from broiler chickens. Importantly, a novel genomic island carrying multiple aminoglycoside resistance genes was identified in 26 aminoglycoside resistantCampylobacter colistrains. Sequence analysis revealed that the genomic island was inserted betweencadFandCOO1582on theC. colichromosome and consists of 14 open reading frames (ORFs), including 6 genes (theaadE–sat4–aphA-3cluster,aacA-aphD,aac, andaadE) encoding aminoglycoside-modifying enzymes. Analysis by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing indicated that theC. coliisolates carrying this unique genomic island were clonal, and the clone of PFGE subtype III and sequence type (ST) 1625 was particularly predominant among theC. coliisolates examined, suggesting that clonal expansion may be involved in dissemination of this resistance island. Additionally, we were able to transfer this genomic island fromC. colito aCampylobacter jejunistrain using natural transformation under laboratory conditions, and the transfer resulted in a drastic increase in aminoglycoside resistance in the recipient strain. These findings identify a previously undescribed genomic island that confers resistance to multiple aminoglycoside antibiotics. Since aminoglycoside antibiotics are used for treating occasional systemic infections caused byCampylobacter, the emergence and spread of this antibiotic resistance genomic island represent a potential concern for public health.

scholarly journals A Novel Gene Cassette,aacA43, in a Plasmid-Borne Class 1 Integron

2011 ◽  
Vol 55 (6) ◽  
pp. 2979-2982 ◽  
Author(s):  
Sally R. Partridge ◽  
Lee C. Thomas ◽  
Andrew N. Ginn ◽  
Agnieszka M. Wiklendt ◽  
Pierre Kyme ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Klebsiella Pneumoniae ◽  
Enterobacter Cloacae ◽  
Gene Cassette ◽  
Class 1 Integron ◽  
Content Type ◽  
Novel Gene ◽  
Class 1

ABSTRACTA novel gene cassette,aacA43, was identified in theaadB-aacA43-oxa10-smr2cassette array in a class 1 integron. Like related aminoglycoside-(6′)-acetyltransferases, AacA43 confers clinically relevant resistance to kanamycin, tobramycin, and some less-used aminoglycosides but not to gentamicin. Although transferable on an IncL/M plasmid,aacA43was identified in only two differentKlebsiella pneumoniaestrains (14 isolates), oneEscherichia colistrain (2 isolates), and oneEnterobacter cloacaestrain in a survey of patients in a Sydney intensive care unit in 2004-2005.

scholarly journals High-Level Aminoglycoside Resistance in Human Clinical Klebsiella pneumoniae Complex Isolates and Characteristics of armA-Carrying IncHI5 Plasmids

2021 ◽  
Vol 12 ◽  
Author(s):  
Xueya Zhang ◽  
Qiaoling Li ◽  
Hailong Lin ◽  
Wangxiao Zhou ◽  
Changrui Qian ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Conjugative Plasmid ◽  
Comparative Genomic ◽  
Aminoglycoside Resistance ◽  
Life Threatening ◽  
Aminoglycoside Resistance Genes ◽  
High Level

Aminoglycosides are important options for treating life-threatening infections. However, high levels of aminoglycoside resistance (HLAR) among Klebsiella pneumoniae isolates have been observed to be increasing frequently. In this study, a total of 292 isolates of the K. pneumoniae complex from a teaching hospital in China were analyzed. Among these isolates, the percentage of HLAR strains was 13.7% (40/292), and 15 aminoglycoside resistance genes were identified among the HLAR strains, with rmtB being the most dominant resistance gene (70%, 28/40). We also described an armA-carrying Klebsiella variicola strain KP2757 that exhibited a high-level resistance to all aminoglycosides tested. Whole-genome sequencing of KP2757 demonstrated that the strain contained one chromosome and three plasmids, with all the aminoglycoside resistance genes (including two copies of armA and six AME genes) being located on a conjugative plasmid, p2757-346, belonging to type IncHI5. Comparative genomic analysis of eight IncHI5 plasmids showed that six of them carried two copies of the intact armA gene in the complete or truncated Tn1548 transposon. To the best of our knowledge, for the first time, we observed that two copies of armA together with six AME genes coexisted on the same plasmid in a strain of K. variicola with HLAR. Comparative genomic analysis of eight armA-carrying IncHI5 plasmids isolated from humans and sediment was performed, suggesting the potential for dissemination of these plasmids among bacteria from different sources. These results demonstrated the necessity of monitoring the prevalence of IncHI5 plasmids to restrict their worldwide dissemination.

scholarly journals Coexistence of aminoglycoside resistance genes in CTX-M-producing isolates of Klebsiella pneumoniae in Bushehr province, Iran

2021 ◽  
Author(s):  
Behrouz Latifi ◽  
Saeed Tajbakhsh ◽  
Leila Ahadi ◽  
Forough Yousefi
Keyword(s):  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Confirmatory Test ◽  
M Gene ◽  
Aminoglycoside Resistance ◽  
Genetic Groups ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Aminoglycoside Resistance Genes ◽  
Antibiotic Resistance Patterns

Background and Objectives: Increasing the rate of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has given rise to a major healthcare issue in clinical settings over the past few years. Treatment of these strains is hardly effective since the plasmid encoding ESBL may also carry other resistance genes including aminoglycosides. The current study aimed to evaluate the prevalence of ESBL-producing K. pneumoniae and investigate the coexistence of Cefoxitamase-Munich (bla ) with aminoglycoside-modifying enzyme (AME) genes, aac(3)IIa as well as aac(6′)Ib, in CTX‑M‑producing K. pneumoniae isolated from patients in Bushehr province, Iran. Materials and Methods: A total of 212 K. pneumoniae isolates were collected and confirmed using polymerase chain re‑ action (PCR) of the malate dehydrogenase gene. Isolates were screened for production of ESBL. Phenotypic confirmatory test was performed using combined disk test. The genes encoding CTX-M groups and AME genes, aac(3)IIa and aac(6′)Ib, were investigated by PCR. Results: The ESBL phenotype was detected in 56 (26.4%) K. pneumoniae isolates. Moreover, 83.9% of ESBL-producing isolates carried the genes for CTX-M type β-lactamases, which were distributed into the two genetic groups of CTX-M-1 (97.8%)- and CTX-M-2 (2.1%)-related enzymes. Notably, among K. pneumoniae isolates containing the blaCTX‑M gene, 68.08% of isolates harbored AME genes. In addition, the coexistence of bla in 46.8% of CTX-M-producing K. pneumoniae isolates. Conclusion: This study provides evidence of a high prevalence of AME genes in CTX-M- producing K. pneumoniae iso‑ lates; therefore, in the initial empirical treatment of infections caused by ESBL-KP in regions with such antibiotic resistance patterns, aminoglycoside combination therapy should be undertaken carefully.

Sign in / Sign up

Export Citation Format

Share Document