scholarly journals An Outbreak of tet(X6)-Carrying Tigecycline-Resistant Acinetobacter baumannii Isolates with a New Capsular Type at a Hospital in Taiwan

Antibiotics ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1239
Author(s):  
Yu-Chia Hsieh ◽  
Jia-Wen Wu ◽  
Yi-Yin Chen ◽  
Tran Lam Tu Quyen ◽  
Wei-Chao Liao ◽  
...  

Dissemination of multidrug-resistant, particularly tigecycline-resistant, Acinetobacter baumannii is of critical importance, as tigecycline is considered a last-line antibiotic. Acquisition of tet(X), a tigecycline-inactivating enzyme mostly found in strains of animal origin, imparts tigecycline resistance to A. baumannii. Herein, we investigated the presence of tet(X) variants among 228 tigecycline-non-susceptible A. baumannii isolates from patients at a Taiwanese hospital via polymerase chain reaction using a newly designed universal primer pair. Seven strains (3%) carrying tet(X)-like genes were subjected to whole genome sequencing, revealing high DNA identity. Phylogenetic analysis based on the PFGE profile clustered the seven strains in a clade, which were thus considered outbreak strains. These strains, which were found to co-harbor the chromosome-encoded tet(X6) and the plasmid-encoded blaOXA-72 genes, showed a distinct genotype with an uncommon sequence type (Oxford ST793/Pasteur ST723) and a new capsular type (KL129). In conclusion, we identified an outbreak clone co-carrying tet(X6) and blaOXA-72 among a group of clinical A. baumannii isolates in Taiwan. To the best of our knowledge, this is the first description of tet(X6) in humans and the first report of a tet(X)-like gene in Taiwan. These findings identify the risk for the spread of tet(X6)-carrying tigecycline- and carbapenem-resistant A. baumannii in human healthcare settings.

Author(s):  
O. A. Kryzhanovskaya ◽  
A. V. Lazareva ◽  
I. V. Chebotar ◽  
Yu. A. Bocharova ◽  
N. A. Mayansky

Aim. Characterize spectrum of antibiotics resistance of Acinetobacter baumannii strains, isolated from patients of 8 surgical and reanimation departments of 3 medical institution of Moscow, and determine molecular-genetic mechanisms of stability of their carbapenem-resistant forms. Materials and methods. 95 strains of A. baumannii, isolated from patients of reanimation and surgical departments of Moscow in 2012 - 2014, were studied. Sensitivity of strains to antibiotics was tested phenotypically according to recommendations of EUCAST. The presence ofVIM, IMP, OXA-23, OXA-40, OXA-48, OXA-58 and NDM genes in the studied strains was determined by polymerase chain reaction in real time. Results. 86.3% of strains turned out to be non-sensitive to carbapenems, sensitive - 13.7%. 80.0% of strains were non-sensitive to gentamicin, 80.0% of strains - to netilmicin, 94.7% of strains - to ciprofloxacin, 2.1% - to colistin. 91.6% of isolates have shown non-sensitivity to members of 2 and more classes of antibiotics, 78.9% of strains - to members of 3 classes. 2 strains were panresistant, 4.2% (4/95) of the isolates were sensitive to all the classes of antibiotics. Metallo-P-lactamases were not detected. Genes of carbapenemases (OXA-23 and/or OXA-40) were detected in 85.3% (81/95) of strains, characterized phenotypically as non-sensitive to carbapenems. Conclusion. The results obtained shown an increase of resistance to carbapenems and multiple resistance in clinically significant strains of A. baumannii. Resistance to carbapenems is associated with OXA-23 and OXA-40 genes. The conclusions allow to justify perspectives of introduction of technologies of molecular-genetic testing of antibiotics resistance.


2019 ◽  
Vol 43 (3) ◽  
pp. 173-176
Author(s):  
Chang-Hun Park

Abstract Background Infections caused by carbapenem-resistant Enterobacterales (CREs) are an emerging problem associated with high rates of morbidity and mortality. CREs are divided into two categories (carbapenemase-producing [CP] CRE and non-CP CRE). The most prevalent carbapenemase produced by Enterobacterales is Klebsiella pneumoniae carbapenemase (KPC) in Korea. Rapid identification of CREs is clinically important in infection control precaution. We compared the performance of two chromogenic media (chromID CARBA agar and CHROMagar KPC agar) for non-CP CREs or CP CREs with blaGES-5, blaNDM-1 or blaVIM-2 in a Korean hospital. Methods The study was carried out during a 3-month period from April to June 2017 during the surveillance program for CRE colonization. Antimicrobial susceptibility testing (AST) and polymerase chain reaction (PCR) were performed at the Korean Centers for Disease Control and Prevention. Results A total of 45 rectal swabs from 42 hospitalized patients were examined. Sensitivity of both chromID CARBA and CHROMagar KPC were 100% for CP CREs; and 50% and 100% for non-CP CREs, respectively. Specificity of chromID CARBA and CHROMagar KPC were 89.2% and 70.3% for CP CRE, respectively; and 76.9% and 66.7% for non-CP CRE, respectively. Conclusions The CHROMagar KPC is useful to monitor non-CP and CP CREs. The chromID CARBA is efficient for rapid detection of CP CREs requiring high contact precaution.


2021 ◽  
Vol 15 ◽  
Author(s):  
Sara Galeb ◽  
Maysaa El Sayed Zaki ◽  
Raghdaa Shrief ◽  
Rasha Hassan ◽  
Mohamed Anies

Background: Proper identification of the causative organism in pediatric sepsis is crucial for early diagnosis and prevention of septic shock and organ failure. Objectives: The present study aimed to evaluate the multiplex Polymerase Chain Reaction (PCR) to detect Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures for these pathogens isolated from children, with hospital-acquired sepsis compared to the conventional biochemical reactions for identification of these organisms. Methods: This study was a cross-sectional study performed on 100 isolates from pediatric blood cultures, including Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia. The study also included 100 isolates of Escherichia coli as a negative control. All isolates were identified by API 20NE and the multiplex PCR, with primers specific to the 3 tested bacteria. Results: Multiplex PCR was positive in 96% of isolates, and 4 isolates had negative results. False positive results were reported with three E. coli strains. Multiplex PCR identified all the isolates of Acinetobacter baumannii, 29 isolates of Pseudomonas aeruginosa, and 27 isolates of Stenotrophomonas maltophilia. Compared to the biochemical identification, the diagnostic value of the multiplex PCR revealed 96.04% sensitivity, 96.9% specificity, 97.00%, positive predictive value, 96.00% negative predictive value, and 96.50% accuracy. Conclusion: The present study highlights the diagnostic value of multiplex PCR to identify Acinetobacter baumannii, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia from positive blood cultures. Multiplex PCR was sensitive, specific, and accurate. The accuracy differs according to the organisms, with 100% accuracy for Acinetobacter baumannii.


Author(s):  
Wan Huang ◽  
Jisheng Zhang ◽  
Lingyi Zeng ◽  
Chengru Yang ◽  
Lining Yin ◽  
...  

BackgroundThis study aimed to determine the molecular characteristics of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolates in a hospital in western Chongqing, southwestern China.MethodsA total of 127 unique CRKP isolates were collected from the Yongchuan Hospital of Chongqing Medical University, identified using a VITEK-2 compact system, and subjected to microbroth dilution to determine the minimal inhibitory concentration. Enterobacteriaceae intergenic repeat consensus polymerase chain reaction and multilocus sequence typing were used to analyze the homology among the isolates. Genetic information, including resistance and virulence genes, was assessed using polymerase chain reaction. The genomic features of the CRKP carrying gene blaKPC-2 were detected using whole-genome sequencing.ResultsST11 was the dominant sequence type in the homology comparison. The resistance rate to ceftazidime-avibactam in children was much higher than that in adults as was the detection rate of the resistance gene blaNDM (p < 0.0001). Virulence genes such as mrkD (97.6%), uge (96.9%), kpn (96.9%), and fim-H (84.3%) had high detection rates. IncF (57.5%) was the major replicon plasmid detected, and sequencing showed that the CRKP063 genome contained two plasmids. The plasmid carrying blaKPC-2, which mediates carbapenem resistance, was located on the 359,625 base pair plasmid IncFII, together with virulence factors, plasmid replication protein (rep B), stabilizing protein (par A), and type IV secretion system (T4SS) proteins that mediate plasmid conjugation transfer.ConclusionOur study aids in understanding the prevalence of CRKP in this hospital and the significant differences between children and adults, thus providing new ideas for clinical empirical use of antibiotics.


Author(s):  
Şeyda Şilan Okalin ◽  
Ayşe Nur Sarı Kaygısız ◽  
Mahmut Cem Ergon ◽  
İbrahim Mehmet Ali Öktem

Objective: In recent years, increasing carbapenem resistance of Enterobacterales bacteria limits treatment options, considerably. The main mechanism of this resistance is the production of carbapenemase enzymes. The aim of this study is to determine carbapenemase gene types in Enterobacterales isolates from our hospitalized patients and assess the clonal associations of the isolates with KPC gene. Method: A total of 48 clinical Enterobacterales isolates resistant to at least one carbapeneme and received between January 2019 and March 2019 were included in the study. Sample types were consisted of urine, blood, tracheal aspirate, wound and sputum. Of these isolates, three were Escherichia coli while 45 were Klebsiella pneumoniae. Types of carbapenemases were investigated by polymerase chain reaction, using specific primers for VIM, IMP, NDM, KPC and OXA-48 genes. PFGE was performed to determine the clonal associations between blaKPC positive K. pnemoniae isolates. Results: According to the results, blaOXA-48 (n=2) and blaKPC (n=1) were found to be present among E. coli isolates. Regarding 45 K. pneumoniae isolates; only blaOXA-48 and only blaNDM were present in 30 and two isolates, respectively. Seven K. pneumoniae isolates were found positive for both blaOXA-48 and blaNDM. Remaining K. pneumoniae isolates (n=6) harboured only blaKPC. None of the isolates were positive for blaIMP and blaVIM. PFGE analysis showed four isolates had the same pulsotype (A), while two had different pulsotypes (B-C). Conclusion: To our knowledge, this is the first report of KPC gene isolated in Dokuz Eylul University Hospital.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5353 ◽  
Author(s):  
Shiang Chiet Tan ◽  
Chun Wie Chong ◽  
Cindy Shuan Ju Teh ◽  
Peck Toung Ooi ◽  
Kwai Lin Thong

BackgroundEnterococcus faecalisandEnterococcus faeciumare ubiquitous opportunistic pathogens found in the guts of humans and farmed animals. This study aimed to determine the occurrence, antimicrobial resistance, virulence, biofilm-forming ability and genotypes ofE. faecalisandE. faeciumfrom swine farms. Correlations between the genotypes, virulotypes, antibiotic resistance, and the environmental factors such as locality of farms and farm hygiene practice were explored.MethodsE. faecalisandE. faeciumstrains were isolated from the oral, rectal and fecal samples of 140 pigs; nasal, urine and fecal samples of 34 farmers working in the farms and 42 environmental samples collected from seven swine farms located in Peninsular Malaysia. Antibiotic susceptibility test was performed using the disk diffusion method, and the antibiotic resistance and virulence genes were detected by Polymerase Chain Reaction. Repetitive Extragenic Palindromic-Polymerase Chain Reaction and Pulsed-Field Gel Electrophoresis were performed to determine the clonality of the strains. Crosstab/Chi-square test and DistLM statistical analyses methods were used to determine the correlations between the genotypes, virulence factors, antibiotic resistance, and the environmental factors.ResultsA total of 211E. faecalisand 42E. faeciumwere recovered from 140 pigs, 34 farmers and 42 environmental samples collected from seven swine farms in Peninsular Malaysia. Ninety-eight percent of the strains were multidrug-resistant (resistant to chloramphenicol, tetracycline, ciprofloxacin and erythromycin). Fifty-two percent of the strains formed biofilms. Virulence genesefa, asaI, gelE,esp,cylandacegenes were detected. Virulence genesefaandasaI were most prevalent inE. faecalis(90%) andE. faecium(43%), respectively. Cluster analyses based on REP-PCR and PFGE showed the strains were genetically diverse. Overall, the strains isolated from pigs and farmers were distinct, except for three highly similar strains found in pigs and farmers. The strains were regional- and host-specific.DiscussionThis study revealed alarming high frequencies of multidrug-resistant enterococci in pigs and swine farmers. The presence of resistance and virulence genes and the ability to form biofilm further enhance the persistence and pathogenicity of the strains. Although the overall clonality of the strains were regionals and host-specific, strains with high similarity were found in different hosts. This study reiterates a need of a more stringent regulation to ensure the proper use of antibiotics in swine husbandry to reduce the wide spread of multidrug-resistant strains.


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