scholarly journals Aeromonas Isolates from Fish and Patients in Tainan City, Taiwan: Genotypic and Phenotypic Characteristics

2019 ◽  
Vol 85 (21) ◽  
Author(s):  
Chi-Jung Wu ◽  
Wen-Chien Ko ◽  
Nan-Yao Lee ◽  
Shu-Li Su ◽  
Chia-Wen Li ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
C2c12 Cell ◽  
Clinical Isolates ◽  
Human Consumption ◽  
Predominant Genotype ◽  
Content Type ◽  
Severe Infections ◽  
Tainan City ◽  
Principal Species

ABSTRACT The present study aimed to isolate Aeromonas from fish sold in the markets as well as in sushi and seafood shops and compare their virulence factors and antimicrobial characteristics with those of clinical isolates. Among the 128 fish isolates and 47 clinical isolates, Aeromonas caviae, A. dhakensis, and A. veronii were the principal species. A. dhakensis isolates carried at least 5 virulence genes, more than other Aeromonas species. The predominant genotype of virulence genes was hlyA lip alt col ela in both A. dhakensis and A. hydrophila isolates, alt col ela in A. caviae isolates, and act in A. veronii isolates. A. dhakensis, A. hydrophila, and A. veronii isolates more often exhibited hemolytic and proteolytic activity and showed greater virulence than A. caviae isolates in Caenorhabditis elegans and the C2C12 cell line. However, the link between the genotypes and phenotypes of the studied virulence genes in Aeromonas species was not evident. Among the four major clinical Aeromonas species, nearly all (99.0%) A. dhakensis, A. hydrophila, and A. veronii isolates harbored blaCphA, which encodes a carbapenemase, but only a minority (6.7%, 7/104) were nonsusceptible to carbapenem. Regarding AmpC β-lactamase genes, blaAQU-1 was exclusively found in A. dhakensis isolates, and blaMOX3 was found only in A. caviae isolates, but only 7.6% (n = 6) of the 79 Aeromonas isolates carrying blaAQU-1 or blaMOX3 exhibited a cefotaxime resistance phenotype. In conclusion, fish Aeromonas isolates carry a variety of combinations of virulence and β-lactamase resistance genes and exhibit virulence phenotypes and antimicrobial resistance profiles similar to those of clinical isolates. IMPORTANCE Aeromonas species can cause severe infections in immunocompromised individuals upon exposure to virulent pathogens in the environment, but the characteristics of environmental Aeromonas species remain unclear. Our study showed that several pathogenic Aeromonas species possessing virulence traits and antimicrobial resistance similar to those of Aeromonas isolates causing clinical diseases were present in fish intended for human consumption in Tainan City, Taiwan.

Antimicrobial resistance and molecular epidemiology of virulence genes among multi-drug resistant clinical isolates in Iran

Gene Reports ◽  
2021 ◽  
pp. 101281
Author(s):  
Mohammadreza Sadr ◽  
Seyed Alireza Fahimzad ◽  
Abdollah Karimi ◽  
Fatemeh Fallah ◽  
Shahnaz Armin ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Molecular Epidemiology ◽  
Virulence Genes ◽  
Clinical Isolates ◽  
Drug Resistant

Emergence of mgrB locus deletion mediating polymyxin resistance in pandemic KPC-producing Klebsiella pneumoniae ST15 lineage

2021 ◽  
Author(s):  
Luís Guilherme de Araújo Longo ◽  
Herrison Fontana ◽  
Viviane Santos de Sousa ◽  
Natalia Chilinque Zambão da Silva ◽  
Ianick Souto Martins ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Type Species ◽  
Virulence Genes ◽  
Health Concern ◽  
Beta Lactamase ◽  
Content Type ◽  
Link Type ◽  
Antimicrobial Resistance Genes ◽  
Encoding Gene

Klebsiella pneumoniae causes a diversity of infections in both healthcare and community settings. This pathogen is showing an increased ability to accumulate antimicrobial resistance and virulence genes, making it a public health concern. Here we describe the whole-genome sequence characteristics of an ST15 colistin-resistant K. pneumoniae isolate obtained from a blood culture of a 79-year-old female patient admitted to a university hospital in Brazil. Kp14U04 was resistant to most clinically useful antimicrobial agents, remaining susceptible only to aminoglycosides and fosfomycin. The colistin resistance in this isolate was due to a ~1.3 kb deletion containing four genes, namely mgrB, yebO, yobH and the transcriptional regulator kdgR. The study isolate presented a variety of antimicrobial resistance genes, including the carbapenemase-encoding gene bla KPC-2, the extended-spectrum beta-lactamase (ESBL)-encoding gene bla SHV-28 and the beta-lactamase-encoding gene bla OXA-1. Additionally, Kp14U04 harboured a multiple stress resistance protein, efflux systems and regulators, heavy metal resistance and virulence genes, plasmids, prophage-related sequences and genomic islands. These features revealed the high potential of this isolate to resist antimicrobial therapy, survive in adverse environments, cause infections and overcome host defence mechanisms.

scholarly journals In Vitro Activity of Sulbactam-Durlobactam against Acinetobacter baumannii-calcoaceticus Complex Isolates Collected Globally in 2016 and 2017

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Sarah M. McLeod ◽  
Samir H. Moussa ◽  
Meredith A. Hackel ◽  
Alita A. Miller
Keyword(s):  
Acinetobacter Baumannii ◽  
Antibacterial Activities ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Single Amino Acid ◽  
Content Type ◽  
Level Of Activity ◽  
Severe Infections ◽  
Sources Of Infection

ABSTRACT Acinetobacter baumannii-calcoaceticus complex (ABC) organisms cause severe infections that are difficult to treat due to preexisting antibiotic resistance. Sulbactam-durlobactam (formerly sulbactam-ETX2514) (SUL-DUR) is a β-lactam–β-lactamase inhibitor combination antibiotic designed to treat serious infections caused by ABC organisms, including multidrug-resistant (MDR) strains. The in vitro antibacterial activities of SUL-DUR and comparator agents were determined by broth microdilution against 1,722 clinical isolates of ABC organisms collected in 2016 and 2017 from 31 countries across Asia/South Pacific, Europe, Latin America, the Middle East, and North America. Over 50% of these isolates were resistant to carbapenems. Against this collection of global isolates, SUL-DUR had a MIC50/MIC90 of 1/2 μg/ml compared to a MIC50/MIC90 of 8/64 μg/ml for sulbactam alone. This level of activity was found to be consistent across organisms, regions, sources of infection, and subsets of resistance phenotypes, including MDR and extensively drug-resistant isolates. The SUL-DUR activity was superior to those of the tested comparators, with only colistin having similar potency. Whole-genome sequencing of the 39 isolates (2.3%) with a SUL-DUR MIC of >4 μg/ml revealed that these strains encoded either the metallo-β-lactamase NDM-1, which durlobactam does not inhibit, or single amino acid substitutions near the active site of penicillin binding protein 3 (PBP3), the primary target of sulbactam. In summary, SUL-DUR demonstrated potent antibacterial activity against recent, geographically diverse clinical isolates of ABC organisms, including MDR isolates.

scholarly journals Comparison of Genospecies and Antimicrobial Resistance Profiles of Isolates in the Acinetobacter calcoaceticus-Acinetobacter baumannii Complex from Various Clinical Specimens

2012 ◽  
Vol 56 (12) ◽  
pp. 6267-6271 ◽  
Author(s):  
Ni Tien ◽  
Bang-Jau You ◽  
Hui-Lan Chang ◽  
Hsiu-Shen Lin ◽  
Chin-Yi Lee ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Acinetobacter Baumannii ◽  
Restriction Analysis ◽  
Acinetobacter Calcoaceticus ◽  
Its Region ◽  
Clinical Isolates ◽  
23S Rrna ◽  
Rrna Gene ◽  
Genotype 3 ◽  
Content Type

ABSTRACTThis study was conducted to compare the prevalences of antimicrobial resistance profiles of clinical isolates in theAcinetobacter calcoaceticus-Acinetobacter baumanniicomplex from sterile and nonsterile sites and to further study the relationship of antimicrobial resistance profiles and genospecies by amplified rRNA gene restriction analysis (ARDRA). A total of 1,381 isolates were tested with 12 different antibiotics to show their antimicrobial susceptibility profiles. A total of 205 clinical isolates were further analyzed by ARDRA of the intergenic spacer (ITS) region of the 16S-23S rRNA gene. It was found that the overall percentage of isolates from nonsterile sites (urine, sputum, pus, or catheter tip) that were resistant to the 12 antibiotics tested was significantly higher than that of isolates from sterile sites (cerebrospinal fluid [CSF], ascites fluid, and bloodstream) (46% versus 22%;P< 0.05). After ARDRA, it was found that 97% of the 62 isolates resistant to all antibiotics tested were theA. baumanniigenospecies, which was identified in only 31% of the isolates susceptible to all antibiotics tested. More genospecies diversity was identified in the isolates susceptible to all antibiotics tested, including genospecies of 13TU (34%), genotype 3 (29%), andA. calcoaceticus(5%). Furthermore, as 91% (10/11) of the isolates from CSF were susceptible to all antibiotics tested, theA. calcoaceticus-A. baumanniicomplex isolates with multidrug resistance could be less invasive than the more susceptible isolates. This study also indicated current emergence of carbapenem-, fluoroquinolone-, aminoglycoside-, and cephalosporin-resistantA. calcoaceticus-A. baumanniicomplex isolates in Taiwan.

scholarly journals Involvement of the AcrAB-TolC Efflux Pump in the Resistance, Fitness, and Virulence of Enterobacter cloacae

2012 ◽  
Vol 56 (4) ◽  
pp. 2084-2090 ◽  
Author(s):  
Astrid Pérez ◽  
Margarita Poza ◽  
Ana Fernández ◽  
Maria del Carmen Fernández ◽  
Susana Mallo ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Pathogenic Bacteria ◽  
Efflux Pump ◽  
Enterobacter Cloacae ◽  
Efflux Pumps ◽  
Clinical Isolates ◽  
Wild Type ◽  
Content Type

ABSTRACTMultidrug efflux pumps have emerged as important mechanisms of antimicrobial resistance in bacterial pathogens. In order to cause infection, pathogenic bacteria require mechanisms to avoid the effects of host-produced compounds, and express efflux pumps may accomplish this task. In this study, we evaluated the effect of the inactivation of AcrAB-TolC on antimicrobial resistance, fitness, and virulence inEnterobacter cloacae, an opportunistic pathogen usually involved in nosocomial infections. Two different clinical isolates ofE. cloacaewere used, EcDC64 (multidrug resistance overexpressing the AcrAB-TolC efflux pump) and Jc194 (basal AcrAB-TolC expression). TheacrAandtolCgenes were deleted in strains EcDC64 and Jc194 to produce, respectively, EcΔacrAand EcΔtolCand JcΔacrAand JcΔtolCknockout (KO) derivatives. Antibiotic susceptibility testing was performed with all isolates, and we discovered that these mechanisms are involved in the resistance ofE. cloacaeto several antibiotics. Competition experiments were also performed with wild-type and isogenic KO strains. The competition index (CI), defined as the mutant/wild-type ratio, revealed that theacrAandtolCgenes both affect the fitness ofE. cloacae, as fitness was clearly reduced in theacrAandtolCKO strains. The median CI values obtainedin vitroandin vivowere, respectively, 0.42 and 0.3 for EcDC64/EcΔacrA, 0.24 and 0.38 for EcDC64/EcΔtolC, 0.15 and 0.11 for Jc194/JcΔacrA, and 0.38 and 0.39 for Jc194/JcΔtolC. Use of an intraperitoneal mouse model of systemic infection revealed reduced virulence in bothE. cloacaeclinical strains when either theacrAortolCgene was inactivated. In conclusion, the structural components of the AcrAB-TolC efflux pump appear to play a role in antibiotic resistance as well as environmental adaptation and host virulence in clinical isolates ofE. cloacae.

scholarly journals Identification of a Chromosomal Integrated DNA Fragment Containing the rmpA2 and iucABCDiutA Virulence Genes in Klebsiella pneumoniae

mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
pp. e01179-20
Author(s):  
Xuemei Yang ◽  
Lianwei Ye ◽  
Yi Li ◽  
Edward Wai-Chi Chan ◽  
Rong Zhang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Antibiotic Resistance Genes ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Transmission Mechanisms ◽  
Genetic Features ◽  
Severe Infections ◽  
First Time ◽  
Encoding Genes

ABSTRACTKlebsiella pneumoniae is increasingly being regarded as a reservoir of diverse antibiotic resistance genes and a pathogen that causes severe infections in both the hospital and the community. In this study, we performed molecular characterization of a carbapenem-resistant and highly virulent K. pneumoniae strain recovered from a hospital patient. The virulence-encoding genes rmpA2 and iucABCDiutA were found to be located in the chromosome and are flanked by IS26 elements. These chromosomally located virulence genes, if not incurring fitness costs, are expected to be much more stable than plasmid-located genes. Detailed analysis of the fragment in which these virulence genes are located showed that the fragment can readily form a circular intermediate that may promote integration of this virulence-encoding fragment into various plasmid backbones and other chromosomal regions. Findings in this work provide new insights into mechanisms of transmission of virulence-encoding genes in K. pneumoniae.IMPORTANCE This study reported for the first time and characterized in detail the genetic features of a mobile virulence-encoding fragment located in the chromosome of a clinical virulent K. pneumoniae strain and revealed the occurrence of a transposition event mediated by IS26. This genetic structure could mediate the transposition of the virulence-encoding fragment into various plasmid backbones and chromosomes through formation of a circular intermediate. Therefore, findings in this work provide important insights into the transmission mechanisms of mobile virulence profiles in K. pneumoniae strains and lay the foundation for devising effective intervention approaches aimed at preventing the dissemination of these virulence-encoding elements.

scholarly journals Molecular and Epidemiological Characteristics of Carbapenemase-Producing Klebsiella pneumoniae Clinical Isolates in Japan

mSphere ◽  
2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Shinsuke Yonekawa ◽  
Tomoki Mizuno ◽  
Ryuichi Nakano ◽  
Akiyo Nakano ◽  
Yuki Suzuki ◽  
...  
Keyword(s):  
Public Health ◽  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Carbapenem Resistance ◽  
Clinical Isolates ◽  
Molecular Characteristics ◽  
Content Type ◽  
Health Threat ◽  
Public Health Threat ◽  
Epidemiological Characteristics

ABSTRACT Carbapenemase-producing Enterobacteriaceae represent a serious public health threat worldwide. Carbapenemase genes, harbored on a transferable plasmid, have been isolated globally with distinct geographical features. Klebsiella pneumoniae, included in Enterobacteriaceae, also produces carbapenemase and often shows hypervirulence. Overlapping carbapenem resistance and hypervirulence in K. pneumoniae have been reported, but such strains have not yet been found in Japan. Here, we screened 104 carbapenemase-producing K. pneumoniae isolates collected from 37 hospitals and outpatient clinics in Japan between September 2014 and July 2015. PCR and DNA sequencing demonstrated IMP-1 in 21 isolates and IMP-6 in 83 isolates, 77 of which coharbored CTX-M-2. Most of the isolates showed low MICs toward imipenem and meropenem but high MICs toward penicillin and cephalosporins. Conjugation experiments with an Escherichia coli J53 recipient showed that most of the plasmids in IMP-6 producers were transferable, whereas only one-half of the plasmids in IMP-1 producers were transferable. PCR-based replicon typing and multiplex PCR identified five isolates belonging to the CG258 non-tonB79 cluster and no isolate belonging to the CG258-tonB79 cluster or sequence type 307 (ST307). Four K1-ST23 isolates, 10 K2-ST65 isolates, and 7 K2-ST86 isolates were detected that harbored virulence genes. The resistance genes in 85 isolates were transferable, but the virulence genes were not transferred. These results demonstrate the acquisition of IMP-type carbapenemase genes and CTX-M-type genes among hypervirulence isolates in Japan, warranting further attention and countermeasures. In this study, we have determined the molecular characteristics and epidemiology of IMP-6 producers that coharbored various CTX-M genes in Japan. IMPORTANCE Carbapenems serve as a last resort for the clinical treatment of multidrug-resistant infections. Therefore, the rapid spread of carbapenemase-producing strains represents a serious public health threat, further limiting antibiotic choices. The current findings of hypervirulent carbapenemase-producing Klebsiella pneumoniae clinical isolates in Japan demonstrate the potential broad spread and transfer of these genes, necessitating close surveillance.

scholarly journals Temporal Trends in Antimicrobial Resistance and Virulence-Associated Traits within the Escherichia coli Sequence Type 131 Clonal Group and ItsH30 andH30-Rx Subclones, 1968 to 2012

2014 ◽  
Vol 58 (11) ◽  
pp. 6886-6895 ◽  
Author(s):  
Bente Olesen ◽  
Jakob Frimodt-Møller ◽  
Rikke Fleron Leihof ◽  
Carsten Struve ◽  
Brian Johnston ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Virulence Genes ◽  
Temporal Trends ◽  
Sequence Type ◽  
Esbl Production ◽  
Content Type ◽  
E Coli ◽  
Biofilm Production

ABSTRACTTo identify possible explanations for the recent global emergence ofEscherichia colisequence type (ST) 131 (ST131), we analyzed temporal trends within ST131 O25 for antimicrobial resistance, virulence genes, biofilm formation, and theH30 andH30-Rx subclones. For this, we surveyed the WHOE. coliandKlebsiellaCentre'sE. colicollection (1957 to 2011) for ST131 isolates, characterized them extensively, and assessed them for temporal trends. Overall, antimicrobial resistance increased temporally in prevalence and extent, due mainly to the recent appearance of theH30 (1997) andH30-Rx (2005) ST131 subclones. In contrast, neither the total virulence gene content nor the prevalence of biofilm production increased temporally, although non-H30 isolates increasingly qualified as extraintestinal pathogenicE. coli(ExPEC). Whereas virotype D occurred from 1968 forward, virotypes A and C occurred only after 2000 and 2002, respectively, in association with theH30andH30-Rx subclones, which were characterized by multidrug resistance (including extended-spectrum-beta-lactamase [ESBL] production:H30-Rx) and absence of biofilm production. Capsular antigen K100 occurred exclusively amongH30-Rx isolates (55% prevalence). Pulsotypes corresponded broadly with subclones and virotypes. Thus, ST131 should be regarded not as a unitary entity but as a group of distinctive subclones, with its increasing antimicrobial resistance having a strong clonal basis, i.e., the emergence of theH30 andH30-Rx ST131 subclones, rather than representing acquisition of resistance by diverse ST131 strains. Distinctive characteristics of theH30-Rx subclone—including specific virulence genes (iutA,afaanddra,kpsII), the K100 capsule, multidrug resistance, and ESBL production—possibly contributed to epidemiologic success, and some (e.g., K100) might serve as vaccine targets.

scholarly journals Characterization of VCC-1, a Novel Ambler Class A Carbapenemase from Vibrio cholerae Isolated from Imported Retail Shrimp Sold in Canada

2016 ◽  
Vol 60 (3) ◽  
pp. 1819-1825 ◽  
Author(s):  
Chand S. Mangat ◽  
David Boyd ◽  
Nicol Janecko ◽  
Sarah-Lynn Martz ◽  
Andrea Desruisseau ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Vibrio Cholerae ◽  
Sequence Similarity ◽  
Laboratory Strain ◽  
Bioinformatic Analysis ◽  
Whole Genome Sequence ◽  
Large Chromosome ◽  
Human Consumption ◽  
Content Type ◽  
Class A

One of the core goals of the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) is to monitor major meat commodities for antimicrobial resistance. Targeted studies with methodologies based on core surveillance protocols are used to examine other foods, e.g., seafood, for antimicrobial resistance to detect resistances of concern to public health. Here we report the discovery of a novel Ambler class A carbapenemase that was identified in a nontoxigenic strain ofVibrio cholerae(N14-02106) isolated from shrimp that was sold for human consumption in Canada.V. choleraeN14-02106 was resistant to penicillins, carbapenems, and monobactam antibiotics; however, PCR did not detect common β-lactamases. Bioinformatic analysis of the whole-genome sequence ofV. choleraeN14-02106 revealed on the large chromosome a novel carbapenemase (referred to here as VCC-1, forVibriocholeraecarbapenemase1) with sequence similarity to class A enzymes. Two copies ofblaVCC-1separated and flanked by ISVch9(i.e., 3 copies of ISVch9) were found in an acquired 8.5-kb region inserted into a VrgG family protein gene. ClonedblaVCC-1conferred a β-lactam resistance profile similar to that inV. choleraeN14-02106 when it was transformed into a susceptible laboratory strain ofEscherichia coli. Purified VCC-1 was found to hydrolyze penicillins, 1st-generation cephalosporins, aztreonam, and carbapenems, whereas 2nd- and 3rd-generation cephalosporins were poor substrates. Using nitrocefin as a reporter substrate, VCC-1 was moderately inhibited by clavulanic acid and tazobactam but not EDTA. In this report, we present the discovery of a novel class A carbapenemase from the food supply.

scholarly journals Rapid Nanopore Sequencing of Plasmids and Resistance Gene Detection in Clinical Isolates

2017 ◽  
Vol 55 (12) ◽  
pp. 3530-3543 ◽  
Author(s):  
Jamie K. Lemon ◽  
Pavel P. Khil ◽  
Karen M. Frank ◽  
John P. Dekker
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Gene ◽  
Plasmid Dna ◽  
Clinical Isolates ◽  
Clinical Microbiology Laboratory ◽  
Nanopore Sequencing ◽  
Gene Detection ◽  
Content Type ◽  
Antimicrobial Resistance Genes ◽  
Antimicrobial Resistance Gene

ABSTRACTRecent advances in nanopore sequencing technology have led to a substantial increase in throughput and sequence quality. Together, these improvements may permit real-time benchtop genomic sequencing and antimicrobial resistance gene detection in clinical isolates. In this study, we evaluated workflows and turnaround times for a benchtop long-read sequencing approach in the clinical microbiology laboratory using the Oxford Nanopore Technologies MinION sequencer. We performed genomic and plasmid sequencing of three clinical isolates with both MinION and Illumina MiSeq, using different library preparation methods (2D and rapid 1D) with the goal of antimicrobial resistance gene detection. We specifically evaluated the advantages of using plasmid DNA for sequencing and the value of supplementing MinION sequences with MiSeq reads for increasing assembly accuracy. Resequencing of three plasmids in a referenceKlebsiella pneumoniaeisolate demonstrated ∼99% accuracy of draft MinION-only assembly and >99.9% accuracy of assembly polished with MiSeq reads. Plasmid DNA sequencing of previously uncharacterized clinical extended-spectrum β-lactamase (ESBL)-producingEscherichia coliandK. pneumoniaeisolates using MinION allowed successful identification of antimicrobial resistance genes in the draft assembly corresponding to all classes of observed plasmid-based phenotypic resistance. Importantly, use of plasmid DNA enabled lower depth sequencing, and assemblies sufficient for full antimicrobial resistance gene annotation were obtained with as few as 2,000 to 5,000 reads, which could be acquired in 20 min of sequencing. With a MinION-only workflow that balances accuracy against turnaround time, full annotation of plasmid resistance gene content could be obtained in under 6 h from a subcultured isolate, less time than traditional phenotypic susceptibility testing.

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