scholarly journals High Prevalence of 16S rRNA Methyltransferase Genes in Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates Associated with Bloodstream Infections in 11 Chinese Teaching Hospitals

2020 ◽  
Vol Volume 13 ◽  
pp. 2189-2197
Author(s):  
Xiaofei Shen ◽  
Li Liu ◽  
Jingyi Yu ◽  
Wenxiu Ai ◽  
Xingwei Cao ◽  
...  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Qing Zhan ◽  
Yanlei Xu ◽  
Bingjie Wang ◽  
Jingyi Yu ◽  
Xiaofei Shen ◽  
...  

Abstract Background The rate of fluoroquinolone (FQ) resistance among carbapenem-resistant Klebsiella pneumoniae (CRKP) is high. The present study aimed to investigate the distribution of fluoroquinolone resistance determinants in clinical CRKP isolates associated with bloodstream infections (BSIs). Results A total of 149 BSI-associated clinical CRKP isolates collected from 11 Chinese teaching hospitals from 2015 to 2018 were investigated for the prevalence of fluoroquinolone resistance determinants, including plasmid-mediated quinolone resistance (PMQR) genes and spontaneous mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes. Among these 149 clinical CRKP isolates, 117 (78.5%) exhibited resistance to ciprofloxacin. The GyrA substitutions (Ser83 → IIe/Phe) and (Asp87 → Gly/Ala) were found among 112 (75.2%) of 149 isolates, while the substitution (Ser80 → IIe) of ParC was found in 111 (74.5%) of the 149 isolates. In total, 70.5% (105/149) of the CRKP isolates had at least two mutations within gyrA as well as a third mutation in parC. No mutations in the QRDRs were found in 31 ciprofloxacin susceptible CRKP isolates. Eighty-nine (56.9%) of 149 were found to carry PMQR genes including qnrS1 (43.0%), aac(6′)-Ib-cr (16.1%), qnrB4 (6.0%), qnrB2 (2.7%), and qnrB1 (1.3%). Nine isolates contained two or more PMQR genes, with one carrying four [aac(6′)-Ib-cr, qnr-S1, qnrB2, and qnrB4]. The co-existence rate of PMQR determinants and mutations in the QRDRs of gyrA and parC reached 68.5% (61/89). Seventy-four (83.1%, 74/89) PMQR-positive isolates harbored extended-spectrum beta-lactamase (ESBL)-encoding genes. Multilocus sequence typing (MLST) analysis demonstrated that the ST11 was the most prevalent STs in our study. Conclusions Mutations in the QRDRs of gyrA and parC were the key factors leading to the high prevalence of fluoroquinolone resistance among BSI-associated CRKP. The co-existence of PMQR genes and mutations in the QRDRs can increase the resistance level of CRKP to fluoroquinolones in clinical settings. ST11 CRKP isolates with identical QRDR substitution patterns were found throughout hospitals in China.


2019 ◽  
Author(s):  
Wenjian Liao ◽  
Dan Li ◽  
Dan Dan Wei ◽  
Fang-lin Du ◽  
Dan Long ◽  
...  

Abstract Background : the existence of 16S rRNA methylase genes would increase treatment difficulty of patients infected with CR-hvKP strains, this study was aimed to testify the prevalence of the 16S rRNA methylase genes genes in the CR-hvKP strains in China.Methods : Thirty-nine carbapenem-resistant hypervirulent Klebsiella pneumoniae (CR-hvKP) isolates collected from a Chinese hospital during the whole year of 2018 were evaluated to characterize the prevalence of 16S rRNA methylase genes. Results : In tatal 66.7% (26/39) of the CR-hvKP isolates were found to carry 16S rRNA methylase genes, and the most frequently detected gene was armA (11,42.3%), followed by rmtB (8,30.8%),and 7 CR-hvKP strains were found to carry both armA and rmtB (26.9%). All the clinical isolates were found to carry at least one carbapenemase gene,with KPC-2 (79.5%,31/39), NDM-1 (10.3%,4/39), and cocarrying KPC-2 and NDM-1 (10.3%,4/39). A total of 89.7% (35/39) isolates carried ESBL genes, including 61.5% (24/39) blaSHV-1 ,71.8% (28/39) blaTEM-1 and 89.7% (35/39) blaCTX-M-1 4. All except four isolates (89.7%,35/39) harbored PMQR genes,with qnrS (82.1%,32/39), aac(6’)-Ib-cr (79.5%,31/39), qnrB (2.6%,1/39).All the 16S rRNA methylase genes-positive CR-hvKP strains were firstly found to cocarry carbapenemase genes, ESBL genes and PMQR genes simultaneously. The most prevalent virulence genes were rmpA2 and entB (100%, 39/39),followed by silS (97.4%, 38/39), ybtS (94.9%, 37/39), iutA (92.3%, 36/39), kpn (92.3%, 36/39), rmpA (87.2%, 34/39), terW (84.6%, 33/39), aerobactin (23.1%, 9/39), repA (17.9%, 7/39), magA (10.3%, 4/39), kfuB C (10.3%, 4/39), w ca G (10.3%, 4/39), allS (10.3%, 4/39). Multilocus sequence typing (MLST) analysis assigned the 39 CR-hvKP isolates into 4 sequence types (STs), with ST11 encompassing 79.5% of the strains. Pulsed field gel electrophoresis (PFGE) typing showed that strains closely related by MLST clustered in major PFGE clusters, of which cluster A accounts for 31 ST11 isolates.The analysis of the transconjugants showed a high-level aminoglycoside resistance and a popular cotransfer of bla KPC-2 with the 16S rRNA methylase genes.Conclusions : 16S rRNA methylase genes are highly prevalent in CR-hvKP clinical isolates especially for ST11, it is therefore critical to continuously monitor the 16S rRNA methylase-producing CR-hvKP epidemiology and minimize potential risks from aminoglycoside -resistant CR-hvKP.


2021 ◽  
Author(s):  
Qing Zhan ◽  
Yanlei Xu ◽  
Bingjie Wang ◽  
Jingyi Yu ◽  
Xiaofei Shen ◽  
...  

Abstract Background The rate of fluoroquinolone (FQ) resistance among the carbapenem-resistant Klebsiella pneumoniae (CRKP) is considerably high. The present study aimed to investigate the distribution of fluoroquinolone resistance determinants in CRKP clinical isolates associated with bloodstream infections (BSIs).Result A total of 149 carbapenem-resistant Klebsiella pneumoniae clinical isolates causing bloodstream infections (BSIs) collected from 11 Chinese teaching hospitals from 2015 to 2018 were investigated for the prevalence of fluoroquinolone resistance determinants including plasmid-mediated quinolone resistance (PMQR) genes and spontaneous mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes. Among 149 CRKP clinical isolates, 117 (78.5%) exhibited resistance to ciprofloxacin. The substitutions (Ser83→IIe/phe) and (Asp87→Gly/Ala) of GyrA were found among 112 (75.2%) of 149 isolates. And the substitution (Ser80→IIe) of ParC was found in 111 (74.5%) of 149 isolates. Seventy point five percent (105/149) CRKP isolates had at least two mutations within gyrA as well as a third mutation in parC. No mutation of QRDRs was found in 31 sensitive CRKP isolates. Eighty-nine (56.9%) of 149 were found to carry PMQR genes including qnrS1 (43.0%), aac(6')-Ib-cr (16.1%), qnrB4 (6.0%), qnrB2 (2.7%) and qnrB1 (1.3%). Nine isolates contained two or more PMQR genes, with one carrying four PMQR genes including aac(6')-Ib-cr, qnr-S1, qnrB2 and qnrB4). The co-existence rate of PMQR determinants and mutations of QRDRs in gyrA and parC reached 68.5% (61/89). Seventy-four (83.1%, 74/89) PMQR-positive isolates harbored ESBL genes. Multilocus sequence typing (MLST) analysis found that the ST types of PMQR-negative isolates were more concentrated relative to PMQR-positive isolates.Conclusion Mutations in QRDRs of gyrA and parC were the key factor leading to the high prevalence of fluoroquinolones resistance among CRKP causing BSIs. PMQR genes can promote QRDRs and increase the resistance level of CRKP to fluoroquinolones in clinical settings. ST11 CRKP isolates with the same substitution patterns in QRDRs spread throughout hospitals in China.


2014 ◽  
Vol 143 (2) ◽  
pp. 376-384 ◽  
Author(s):  
Y. LIU ◽  
L.-G. WAN ◽  
Q. DENG ◽  
X.-W. CAO ◽  
Y. YU ◽  
...  

SUMMARYA total of 180 non-duplicate carbapenem-resistant Klebsiella pneumoniae isolates were recovered from patients hospitalized between December 2010 and January 2012 at a Chinese hospital. Eight KPC-2, four NDM-1, one VIM-2, and five KPC-2 plus IMP-4 producers were identified and all were multidrug resistant due to the presence of other resistance determinants, including extended-spectrum β-lactamases (CTX-M-15, SHV-12), 16S rRNA methylases (armA, rmtB) and plasmid-mediated quinolone-resistance determinants (qnrA, B, S, aac(6′)-Ib-cr). Nine K. pneumoniae clones (Kpn-A1/ST395, Kpn-A3/ST11, Kpn-A2/ST134, Kpn-B/ST263, Kpn-C/ST37, Kpn-D/ST39, Kpn-E/ST1151, Kpn-F/ST890, Kpn-G/ST1153) were identified. blaKPC-2 was located on transferable ~65 kb IncL/M (ST395, ST11, ST134, ST39) and ~100 kb IncA/C (ST37, ST1153, ST890) plasmids, respectively. On the other hand, blaNDM-1 was associated with a ~70 kb IncA/C plasmid (ST263). However, non-typable plasmids of ~40 kb containing blaVIM-2 were detected in the ST1151 clone. This work reports the first co-occurrence of four diverse types of carbapenemase of K. pneumoniae clones from a single hospital in China. IncA/C, IncL/M, and other successful plasmids may be important for the dissemination of carbapenemases, producing a complex epidemiological picture.


2021 ◽  
Vol 9 (2) ◽  
pp. 271
Author(s):  
Yuarn-Jang Lee ◽  
Chih-Hung Huang ◽  
Noor Andryan Ilsan ◽  
I-Hui Lee ◽  
Tzu-Wen Huang

Urinary tract infections (UTIs) are common in clinics and hospitals and are associated with a high economic burden. Enterobacterium Klebsiella pneumoniae is a prevalent agent causing UTIs. A high prevalence of carbapenem-resistant K. pneumoniae (CRKP) has emerged recently and is continuing to increase. Seventeen urinary CRKP isolates collected at a teaching hospital in Taiwan from December 2016 to September 2017 were analyzed to elucidate their drug resistance mechanisms. Two-thirds of the isolates were obtained from outpatients. Antimicrobial susceptibility tests demonstrated multidrug resistance in all the isolates. Multilocus sequence typing analysis showed high diversity among the isolates. PCR analysis demonstrated the presence of carbapenemases in three isolates. All isolates carried at least one other extended-spectrum β-lactamase, including TEM, DHA, and CTX-M. Fifteen isolates contained mutations in one of the outer membrane porins that were assessed. The expression levels of the acrB and/or oqxB efflux pump genes, as determined by qRT-PCR, were upregulated in 11 isolates. Six isolates might have utilized other efflux pumps or antimicrobial resistance mechanisms. These analyses demonstrated a highly diverse population and the presence of complex resistance mechanisms in urinary isolates of K. pneumoniae.


2021 ◽  
Author(s):  
Yuzhen Qiu ◽  
Wen Xu ◽  
Yunqi Dai ◽  
Ruoming Tan ◽  
Jialin Liu ◽  
...  

Abstract Background: Carbapenem-resistant Klebsiella pneumoniae bloodstream infections (CRKP-BSIs) are associated with high morbidity and mortality rates, especially in critically ill patients. Comprehensive mortality risk analyses and therapeutic assessment in real-world practice are beneficial to guide individual treatment.Methods: We retrospectively analyzed 87 patients with CRKP-BSIs (between July 2016 and June 2020) to identify the independent risk factors for 28-day all-cause mortality. The therapeutic efficacies of tigecycline-and polymyxin B-based therapies were analyzed.Results: The 28-day all-cause mortality and in-hospital mortality rates were 52.87% and 67.82%, respectively, arising predominantly from intra-abdominal (56.32%) and respiratory tract infections (21.84%). A multivariate analysis showed that 28-day all-cause mortality was independently associated with the patient’s APACHE II score (p = 0.002) and presence of septic shock at BSI onset (p = 0.006). All-cause mortality was not significantly different between patients receiving tigecycline- or polymyxin B-based therapy (55.81% vs. 53.85%, p = 0.873), and between subgroups mortality rates were also similar. Conclusions: Critical illness indicators (APACHE II scores and presence of septic shock at BSI onset) were independent risk factors for 28-day all-cause mortality. There was no significant difference between tigecycline- and polymyxin B-based therapy outcomes. Prompt and appropriate infection control should be implemented to prevent CRKP infections.


2016 ◽  
Vol 06 (09) ◽  
pp. 662-670
Author(s):  
Amina Amal Mahmoud Nour El Din ◽  
Reem Abdel Hameed Harfoush ◽  
Hadir Ahmed Said Okasha ◽  
Dina Aly El Sayed Kholeif

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