scholarly journals Four Types of ST11 Novel Mutations From Increasing Carbapenem-Resistant Klebsiella pneumoniae in Guangdong, 2016–2020

2021 ◽  
Vol 12 ◽  
Author(s):  
Yunhu Zhao ◽  
Yalong Liao ◽  
Ni Zhang ◽  
Suling Liu ◽  
Jiao Zhang ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Evolutionary Tree ◽  
Molecular Characteristics ◽  
Potential Threat ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Separate Branch ◽  
First Choice ◽  
Prevalent Strain ◽  
Antibacterial Susceptibility

Objectives: This study aimed to explore changes in carbapenem-resistant Klebsiella pneumoniae (CR-KP) isolates collected in Guangdong over the period of 2016–2020.Methods: Antibacterial susceptibility was quantified through VITEK 2 compact and K-B method. Carbapenemase phenotypes and genotypes were characterized by modified carbapenem inactivation method (mCIM), EDTA-carbapenem inactivation method (eCIM), and polymerase chain reaction (PCR). Molecular characteristics and evolutionary trends were analyzed by multilocus sequence typing and evolutionary tree.Results: Isolates (2,847) of K. pneumoniae were separated in 2016–2020, and the separate rate of CR-KP increased from 5.65 to 9.90% (p = 0.009). The top 3 wards were intensive care unit (ICU) (21.92%), neonatal wards (13.70%), and respiratory wards (12.33%). In 146 CR-KP strains, serine carbapenemase was the main phenotype, and KPC was the main genotype, and 57 contained two resistant genes, and 1 contained three resistant genes. Two polygenic strains were first found: IMP + GES and KPC + NDM + VIM, but all the phenotypes were metalloenzyme, which indicated that metalloenzyme was usually the first choice for CR-KP resistance. In addition, all the ST54 of metalloenzyme type contained IMP, and all the ST45, ST37, and ST76 contained OXA. ST11 was the most prevalent (42.47%); ST11 and its mutants proved the predominant sequence type making up 51.1% of the carbapenemase-producing isolates. A novel type of ST11 mutation, the rpoB was mutated from sequence 1 to sequence 146, was in an independent separate branch on the evolutionary tree and was resistant to all antibacterial agents. The other three mutants, rpoB 1–15, infB 3–148, and infB 3–80, are also resistant to all antibacteria. Of note, all the four mutants produced serine carbapenemase and contained KPC, and indicated that the prevalent strain in China, ST11, has serious consequences and potential outbreaks.Conclusion: The infection rate of CR-KP has increased, and ICU and neonatal wards have become the key infection areas. Producing serine enzyme, the KPC genotype, and ST11 are the predominant CR-KP. Polygenic strains and ST11 mutation made clinical treatment difficult and may become a potential threat.

scholarly journals Carbapenemase Production and Epidemiological Characteristics of Carbapenem-Resistant Klebsiella pneumoniae in Western Chongqing, China

2022 ◽  
Vol 11 ◽  
Author(s):  
Wan Huang ◽  
Jisheng Zhang ◽  
Lingyi Zeng ◽  
Chengru Yang ◽  
Lining Yin ◽  
...  
Keyword(s):  
Polymerase Chain Reaction ◽  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Resistance Rate ◽  
Molecular Characteristics ◽  
Chain Reaction ◽  
Detection Rates ◽  
Carbapenem Resistant ◽  
Polymerase Chain ◽  
Epidemiological Characteristics

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.

scholarly journals 1189. A Comprehensive Characterization of the Emerging Carbapenem-Resistant Klebsiella pneumoniae Clinical Isolates From a Public Hospital in Lima, Peru

2018 ◽  
Vol 5 (suppl_1) ◽  
pp. S359-S360 ◽  
Author(s):  
Fiorella Krapp ◽  
Catherine Amaro ◽  
Karen Ocampo ◽  
Lizeth Astocondor ◽  
Noemi Hinostroza ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Dna Extraction ◽  
Antibiotic Susceptibility ◽  
Tertiary Care ◽  
Clinical Isolates ◽  
Molecular Characteristics ◽  
Care Hospital ◽  
Carbapenem Resistant ◽  
Carbapenemase Gene ◽  
String Test

Abstract Background In contrast with other countries in Latin America, Peru had been notoriously spared by the global dissemination of carbapenem-resistant Klebsiella pneumoniae (CR-Kp), until recently. Even though, isolated cases of KPC-producing K. pneumoniae had been reported since 2013, it was not until 2016 that the first outbreak of NDM- producing K. pneumoniae was described in Peru. By 2017, rapid emergence of CR-Kp took place in Hospital Cayetano Heredia (HCH), a tertiary care hospital in Lima. Here, we provide a description of clinical, microbiological and molecular characteristics of CR-Kp isolates recovered at HCH. Methods Retrospective review of all CR-Kp clinical isolates recovered at HCH until December 2017. Antibiotic susceptibility data were obtained during routine care (Vitek or disc diffusion) and was assessed using CLSI breakpoints. DNA extraction was performed by heat shock, and PCR was performed to assess carriage of blaNDM gene. String test was performed to detect hypermucoviscosity. Results The first case of CR-Kp in HCH dated from July 2015. Since then, a total of 69 CR-Kp clinical isolates, from 60 patients have been recovered until December 2017. A significant increase in the number of cases was observed during 2017 (Figure 1). The average age of patients was 55. Urinary, and respiratory sources of infection or colonization were the most common ones (35% and 30%, respectively), followed by blood stream (17%) and intraabdominal (10%) infections. Isolate recovery and DNA extraction was achieved in 40 cases. Of these, 15 (38%) had a positive PCR for blaNDM carbapenemase gene (Figure 2). Antibiotic susceptibility testing revealed that amikacin was the most effective antimicrobial with the rest of antimicrobials having extremely high rates of resistance (Figure 3). String test was positive in two of these isolates, suggesting that hypervirulent CR-KP might be emerging in this region. Conclusion An epidemic of CR-Kp has established in our hospital, representing the first one reported in Peru. The different mechanisms of carbapenem resistance found suggest a polyclonal expansion. Amikacin remains the only active antimicrobial within the routinely tested antibiotics, highlighting the need to add other antimicrobials to the routine panel. Disclosures All authors: No reported disclosures.

scholarly journals Molecular Characterization of Carbapenemase-Producing Escherichia coli and Klebsiella pneumoniae in the Countries of the Gulf Cooperation Council: Dominance of OXA-48 and NDM Producers

2014 ◽  
Vol 58 (6) ◽  
pp. 3085-3090 ◽  
Author(s):  
Hosam M. Zowawi ◽  
Anna L. Sartor ◽  
Hanan H. Balkhy ◽  
Timothy R. Walsh ◽  
Sameera M. Al Johani ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
United Arab Emirates ◽  
Gulf Cooperation Council ◽  
Mechanisms Of Resistance ◽  
Antibiotic Resistant ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Gcc Countries

ABSTRACTThe molecular epidemiology and mechanisms of resistance of carbapenem-resistantEnterobacteriaceae(CRE) were determined in hospitals in the countries of the Gulf Cooperation Council (GCC), namely, Saudi Arabia, United Arab Emirates, Oman, Qatar, Bahrain, and Kuwait. Isolates were subjected to PCR-based detection of antibiotic-resistant genes and repetitive sequence-based PCR (rep-PCR) assessments of clonality. Sixty-two isolates which screened positive for potential carbapenemase production were assessed, and 45 were found to produce carbapenemase. The most common carbapenemases were of the OXA-48 (35 isolates) and NDM (16 isolates) types; 6 isolates were found to coproduce the OXA-48 and NDM types. No KPC-type, VIM-type, or IMP-type producers were detected. Multiple clones were detected with seven clusters of clonally relatedKlebsiella pneumoniae. Awareness of CRE in GCC countries has important implications for controlling the spread of CRE in the Middle East and in hospitals accommodating patients transferred from the region.

scholarly journals Comparative analysis of Clinial Carbapenem- Resistant (CR), Hypermucoviscous (HM) and CR-HM Klebsiella pneumoniae isolates in China

2020 ◽  
Author(s):  
Jun-Ying Zhu ◽  
Guang-Yu Wang ◽  
Qing Wei ◽  
Zhen Shen ◽  
Qiong Li ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Carbapenem Resistance ◽  
Resistance Rate ◽  
Molecular Characteristics ◽  
Carbapenem Resistant ◽  
Recent Emergence ◽  
String Test

Abstract Background: Although carbapenem-resistant Klebsiella pneumoniae (CRKP) and hypermucoviscous K. pneumoniae (HMKP) were largely non-overlapping, the recent emergence of CR-HMKP has raised great alarm in the world. We compared the molecular characteristics of CRKP, HMKP and CR-HMKP isolates.Results: 220 cases of K. pneumoniae isolates was collected and identified between Jan 2015 and Dec 2016 from Renji Hospital. Carbapenem resistance test and string test were performed to screen CRKP, HMKP and CR-HMKP isolates. All the CRKP, HMKP and CR-HMKP isolates were investigated for capsular genotyping, virulence genes and resistance genes by PCR and DNA sequencing. Multilocus sequence typing (MLST) was used to characterize isolates sequence types (STs). Serum killing assay and mouse lethality assay were respectively performed to confirm the virulence of the isolates in vitro and in vivo. Of 220 K. pneumoniae，71 HMKP, 84 CRKP and 8 CR-HMKP were identified. Resistance rate to carbapenems was significantly higher in CRKP than HMKP and CR-HMKP. For MLST and serotyping, ST23 (26.8%)，K1 (33.8%) and K2 (23.9%) serotypes were the most common in HMKP isolates while ST11 (84.5%, 100%) and K-nontypable (91.6%, 100%) were the predominant types in CRKP and CR-HMKP isolates. The existence of virulence genes rmpA, magA and iutA was significantly higher in HMKP while the prevalence of resistance gene blaKPC-2 was higher in CRKP and CR-HMKP. Virulence test in vivo and in vitro both showed the lower virulence of CRKP and CR-HMKP compared to HMKP.Conclusions: In spite of low virulence, the emergence of CR-HMKP indicates a confluence of hypermucoviscous phenotype and carbapenem resistance. Furthermore, the similar molecular characteristics between CRKP and CR-HMKP suggested that CR-HMKP might evolve from CRKP.

scholarly journals A Recombinase Aided Amplification Assay for Rapid Detection of the Klebsiella pneumoniae Carbapenemase Gene and Its Characteristics in Klebsiella pneumoniae

2021 ◽  
Vol 11 ◽  
Author(s):  
Weiwei Zhang ◽  
Yanling Feng ◽  
Hanqing Zhao ◽  
Chao Yan ◽  
Junxia Feng ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Rapid Detection ◽  
Detection Method ◽  
Multidrug Resistant ◽  
Molecular Characteristics ◽  
Klebsiella Pneumoniae Carbapenemase ◽  
Carbapenem Resistant ◽  
Fecal Carriage ◽  
Carbapenemase Gene ◽  
Amplification Assay

Klebsiella pneumoniae carbapenemase genes (blaKPC) play an important role in carbapenem-resistant Enterobacteriaceae in China. A rapid detection method for blaKPC genes and investigations into the molecular characteristics of blaKPC positive Klebsiella pneumoniae were necessary. In this study, an easy and rapid recombinase aided amplification assay (RAA) for blaKPC was established. This protocol could be completed at 39°C in 15–20 min. The sensitivity of this assay was determined as 48 copies per reaction, and the specificity was 100%. The blaKPC RAA method could be used for clinical diagnosis and epidemiological investigation. Among 801 fecal samples from inpatients, 34 blaKPC positive isolates were identified from each sample, of which 23 isolates were K. pneumoniae. ST11 with blaKPC-2 was the most prevalent type. All these strains were multidrug resistant and carried various virulence genes. Fecal carriage of blaKPC positive carbapenem-resistant K.pneumoniae poses significant challenges for public health control.

In vitro and in vivo synergistic effects of tigecycline combined with aminoglycosides on carbapenem-resistant Klebsiella pneumoniae

2021 ◽  
Author(s):  
Wentao Ni ◽  
Deqing Yang ◽  
Jie Guan ◽  
Wen Xi ◽  
Dexun Zhou ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Synergistic Effects ◽  
Molecular Characteristics ◽  
Synergistic Activity ◽  
Significant Activity ◽  
Clinical Pharmacokinetics ◽  
Carbapenem Resistant ◽  
Time Kill

Abstract Objectives Carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections represent severe threats to public health worldwide. The aim of this study was to assess potential synergistic interaction between tigecycline and aminoglycosides via in vitro and in vivo studies. Methods Antibiotic resistance profiles and molecular characteristics of 168 CR-KP clinical isolates were investigated by susceptibility testing, PCR and MLST. Chequerboard tests and time–kill assays were performed for 20 CR-KP isolates to evaluate in vitro synergistic effects of tigecycline combined with aminoglycosides. A tissue-cage infection model of rats was established to evaluate in vivo synergistic effects. Different doses of tigecycline and aminoglycosides alone or in combination were administered for 7 days via tail vein injection. Antibiotic efficacy was evaluated in tissue-cage fluid and emergence of resistance was screened. Results The chequerboard tests showed that this combination displayed synergistic or partial synergistic activity against CR-KP. The time–kill assays further demonstrated that strong synergistic effects of such a combination existed against isolates that were susceptible to both drugs but for resistant isolates no synergy was observed if clinical pharmacokinetics were taken into consideration. The in vivo study showed that the therapeutic effectiveness of combination therapies was better than that of monotherapy for susceptible isolates, suggesting in vivo synergistic effects. Furthermore, combinations of tigecycline with an aminoglycoside showed significant activity in reducing the occurrence of tigecycline-resistant mutants. Conclusions Compared with single drugs, tigecycline combined with aminoglycosides could exert synergistic effects and reduce the emergence of tigecycline resistance. Such a combination might be an effective alternative when treating CR-KP infections in clinical practice.

scholarly journals Synergistic activity of fosfomycin–meropenem and fosfomycin–colistin against carbapenem resistant Klebsiella pneumoniae: an in vitro evidence

2020 ◽  
pp. FSO461 ◽  
Author(s):  
Yamuna Devi Bakthavatchalam ◽  
Abirami Shankar ◽  
Dhiviya Prabaa Muthuirulandi Sethuvel ◽  
Kalaiarasi Asokan ◽  
Kalaiarasi Kanthan ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Klebsiella Pneumoniae ◽  
Blood Cultures ◽  
Synergistic Activity ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Time Kill ◽  
Synergistic Antibacterial Activity

Aim: To evaluate the antibacterial activity of fosfomycin–meropenem and fosfomycin–colistin combinations against carbapenem-resistant Klebsiella pneumoniae (CR-Kp). Methods: A total of 50 CR-Kp isolates recovered from blood cultures were included in this study. All the CR-Kp isolates were screened for the presence of carbapenem resistant genes blaIMP. blaVIM. blaNDM. blaOXA-48 like, blaKPC. blaGES.#x00A0;and blaSPM. Combination testing of fosfomycin–meropenem and fosfomycin–colistin were performed using time-kill assay. Results: Fosfomycin–meropenem combination showed synergy in 20% of the tested CR-Kp isolates. While, fosfomycin–colistin exhibited synergy against 16% of the isolates. A total of 68% (n = 34) of CR-Kp isolates were characterised as OXA-48-like producers and 22% (n = 11) as NDM producers. Synergistic activity of these combinations was observed against OXA-48, NDM and NDM + OXA-48 co-producers. Conclusion: Considerable synergistic antibacterial activity of fosfomycin–meropenem and fosfomycin–colistin was not observed against CR-Kp isolates. Therefore, these combinations may not be promising for infections associated with CR-Kp.

scholarly journals Physiological and molecular characteristics of carbapenem resistance in Klebsiella pneumoniae and Enterobacter aerogenes

2016 ◽  
Vol 10 (06) ◽  
pp. 592-599 ◽  
Author(s):  
Rito Santo Pereira ◽  
Vanessa Cordeiro Dias ◽  
Alessandra Barbosa Ferreira-Machado ◽  
Juliana Alves Resende ◽  
André Netto Bastos ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Klebsiella Pneumoniae ◽  
Genetic Markers ◽  
Bacterial Resistance ◽  
Enterobacter Aerogenes ◽  
Carbapenem Resistance ◽  
Tertiary Hospital ◽  
Resistant Bacteria ◽  
Molecular Characteristics ◽  
Carbapenem Resistant

Introduction: Bacterial resistance is a growing concern in the nosocomial environment in which Klebsiella pneumoniae and Enterobacter aerogenes play an important role due to their opportunism and carbapenemase-production. This work aimed to evaluate physiological and molecular characteristics of carbapenem-resistant K. pneumoniae and E. aerogenes isolated in a Brazilian tertiary hospital. Methodology: In total, 42 carbapenem-resistant bacteria isolated from clinical specimens were included (21 K. pneumoniae and 21 E. aerogenes). Drug-sensitive K. pneumoniae (n = 27) were also included. Antimicrobial susceptibility and biocide tolerance patterns, hemolytic activity, tolerance to oxidative stress, and aggregative ability were assessed. Genetic markers related to carbapenem resistance, or ESBL-production were screened by PCR. Results: Compared to drug-sensitive strains, carbapenem-resistant K. pneumoniae were more tolerant to biocides and to oxidative stress, and they displayed an increase in biofilm formation. The genetic markers blaKPC (95.2%) and blaTEM (90.5%) were the most frequent. Among the carbapenem-resistant E. aerogenes strains, blaKPC, and blaTEM were detected in all bacteria. Drug-sensitive E. aerogenes were not isolated in the same period. blaSHV, blaVIM, and blaCTX markers were also observed among carbapenem-resistant bacteria. Conclusions: Results suggest that carbapenemase-producing enterobacteria might show peculiar characteristics regarding their physiology associated with their environmental persistency, virulence, and multidrug resistance. The observed phenomenon may have implications not only for antimicrobial chemotherapy, but also for the prognosis of infectious diseases and infection control.

Detection of NDM-1 and VIM Genes in Carbapenem-Resistant Klebsiella pneumoniae Isolates from a Tertiary Health-Care Center in Kathmandu, Nepal

Chemotherapy ◽  
2021 ◽  
pp. 1-11
Author(s):  
Sabita Thapa ◽  
Nabaraj Adhikari ◽  
Anil Kumar Shah ◽  
Ishworiya Lamichhane ◽  
Binod Dhungel ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Bacterial Infections ◽  
Care Center ◽  
Diffusion Method ◽  
Accurate Identification ◽  
Clinical Specimens ◽  
Health Care Center ◽  
Carbapenem Resistant ◽  
Resistant Genes ◽  
Specificity And Sensitivity

<b><i>Background:</i></b> <i>Klebsiella pneumoniae</i> is one of the leading causes of nosocomial infections. Carbapenems are used as the last resort for the treatment of multidrug resistant Gram-negative bacterial infections. In recent years, resistance to these lifesaving drugs has been increasingly reported due to the production of carbapenemase. The main objective of this study was to detect the carbapenem-resistant genes <i>bla</i><sub>NDM-1</sub> and <i>bla</i><sub>VIM</sub> in <i>K. pneumoniae</i> isolated from different clinical specimens. <b><i>Methods:</i></b> A total of 585 clinical specimens (urine, pus, sputum, blood, catheter tips, and others) from human subjects attended at Annapurna Neurological Institute and Allied Sciences, Kathmandu were obtained in the period between July 2018 and January 2019. The specimens were isolated and identified for <i>K. pneumoniae</i>. All <i>K</i>. <i>pneumoniae</i> isolates were processed for antimicrobial susceptibility testing (AST) using the disk diffusion method. The isolates were further phenotypically confirmed for carbapenemase production by the modified Hodge test (MHT) using imipenem (10 μg) and meropenem (10 μg) discs. Thus, confirmed carbapenemase-producing isolates were further screened for the production of <i>bla</i><sub>NDM-1</sub> and <i>bla</i><sub>VIM</sub> using conventional polymerase chain reaction (PCR). <b><i>Results:</i></b> Among the clinical isolates tested, culture positivity was 38.29% (224/585), and the prevalence of <i>K. pneumoniae</i> was 25.89% (58/224). On AST, <i>K. pneumoniae</i> exhibited resistance toward carbapenems including ertapenem, meropenem, and imipenem, while it showed the highest susceptibility rate against to tigecycline (93.1%; 54/58). Overall, AST detected 60.34% (35/58) carbapenem-resistant isolates, while the MHT phenotypically confirmed 51.72% (30/58) isolates as carbapenemase-producers and 48.28% (28/58) as carbapenemase nonproducers. On subsequent screening for resistant genes among carbapenemase-producers by PCR assay, 80% (24/30) and 3.33% (1/30) isolates were found to be positive for <i>bla</i><sub>NDM-1</sub> and <i>bla</i><sub>VIM</sub>, respectively. In the same assay among 28 carbapenem nonproducing isolates, 9 (32.14%) isolates were positive for <i>bla</i><sub>NDM-1</sub> gene while none of them were tested positive for <i>bla</i><sub>VIM</sub> gene. <b><i>Conclusions:</i></b> Molecular detection of resistant genes provides greater specificity and sensitivity than those with conventional techniques, thus aiding in accurate identification of antimicrobial resistance and clinical management of the disease.

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