scholarly journals Diversity of Molecular Mechanisms Conferring Carbapenem Resistance toPseudomonas aeruginosaIsolates from Saudi Arabia

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Mohamed H. Al-Agamy ◽  
Katy Jeannot ◽  
Taghrid S. El-Mahdy ◽  
Hassan A. Samaha ◽  
Atef M. Shibl ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Molecular Mechanisms ◽  
Efflux Pump ◽  
Carbapenem Resistance ◽  
Tertiary Hospital ◽  
Carbapenem Resistant ◽  
Extended Spectrum ◽  
Resistance Patterns ◽  
O 15 ◽  
O 11

Background.This study described various molecular and epidemiological characters determining antibiotic resistance patterns inPseudomonas aeruginosaisolates.Methods.A total of 34 carbapenem-resistantP. aeruginosaclinical isolates were isolated from samples collected at a tertiary hospital in Riyadh, Saudi Arabia, from January to December 2011. Susceptibility testing, serotyping, molecular characterization of carbapenem resistance, and pulsed-field gel electrophoresis (PFGE) were performed.Results.All isolates were resistant to ceftazidime, and more than half were highly resistant (minimum inhibitory concentration (MIC) > 256 mg/L). Fifteen isolates had MIC values ≥64 mg/L for any of the carbapenems examined. Vietnamese extended-spectrumβ-lactamase (VEB-1) (n=16/34) and oxacillinase (OXA-10) (n=14/34) were the most prevalent extended-spectrumβ-lactamase and penicillinase, respectively. Verona imipenemase (VIM-1, VIM-2, VIM-4, VIM-11, and VIM-28) and imipenemase (IMP-7) variants were found in metallo-β-lactamase producers. A decrease in outer membrane porin gene (oprD) expression was seen in nine isolates, and an increase in efflux pump gene (MexAB) expression was detected in five isolates. Six serotypes (O:1, O:4, O:7, O:10, O:11, and O:15) were found among the 34 isolates. The predominant serotype was O:11 (16 isolates), followed by O:15 (nine isolates). PFGE analysis of the 34 carbapenem-resistantP. aeruginosaisolates revealed 14 different pulsotypes.Conclusions.These results revealed diverse mechanisms conferring carbapenem resistance toP. aeruginosaisolates from Saudi Arabia.

scholarly journals Prevalence and mechanisms of carbapenem resistance  among  Klebsiella aerogenes  in a tertiary hospital in China

2020 ◽  
Author(s):  
Luxiang Liu ◽  
Jingjing Quan ◽  
Dongdong Zhao ◽  
Weichao Liao ◽  
Jiaojian Lv ◽  
...  
Keyword(s):  
Intensive Care ◽  
Efflux Pump ◽  
Carbapenem Resistance ◽  
Clonal Diversity ◽  
Tertiary Hospital ◽  
Molecular Characteristics ◽  
Klebsiella Aerogenes ◽  
Carbapenem Resistant ◽  
Efflux Pump Inhibition ◽  
Clonal Spread

Abstract Background: Klebsiella aerogenes has emerged as one of the most important nosocomial pathogens for patients in intensive care units (ICU) in recent years. This study aims to evaluated the prevalence and molecular characteristics of clinical carbapenem-resistant K. aerogenes (CRKA) isolates in a tertiary hospital in China.Results: Twenty CRKA were identified among all the isolates, with the rate of 5.5% (20/364). Six CRKA isolates produced KPC-2 and 1 CRKA isolate produced NDM-1. PFGE and MLST indicated that the 20 CRKA strains were clonal diversity. All the bla KPC-2 gene and bla NDM-1 gene were located on plasmids and all the plasmids with bla KPC-2 and bla NDM-1 genes could successfully transferred to EC600 or J53. Twelve of 13 CRKA strains without any carbapenemase genes were positive for efflux pump inhibition test.Conclusion: Overall, the prevalence of CRKA in the tertiary hospital in Zhejiang Province of China is 5.5%. Only 35% of CRKA produce carbapenemase and efflux pumps might play an important role in the carbapenem resistance of K. aerogenes. It is necessary to strengthen the surveillance of carbapenem resistance in the hospital to prevent the horizontal and clonal spread of CRKA.

scholarly journals Characterization of resistance mechanisms of Enterobacter cloacae Complex co-resistant to carbapenem and colistin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Shixing Liu ◽  
Renchi Fang ◽  
Ying Zhang ◽  
Lijiang Chen ◽  
Na Huang ◽  
...  
Keyword(s):  
Lipid A ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Enterobacter Cloacae ◽  
Resistance Mechanisms ◽  
Colistin Resistance ◽  
Carbapenem Resistant ◽  
Horizontal Spread

Abstract Background The emergence of carbapenem-resistant and colistin-resistant ECC pose a huge challenge to infection control. The purpose of this study was to clarify the mechanism of the carbapenems and colistin co-resistance in Enterobacter cloacae Complex (ECC) strains. Results This study showed that the mechanisms of carbapenem resistance in this study are: 1. Generating carbapenemase (7 of 19); 2. The production of AmpC or ESBLs combined with decreased expression of out membrane protein (12 of 19). hsp60 sequence analysis suggested 10 of 19 the strains belong to colistin hetero-resistant clusters and the mechanism of colistin resistance is increasing expression of acrA in the efflux pump AcrAB-TolC alone (18 of 19) or accompanied by a decrease of affinity between colistin and outer membrane caused by the modification of lipid A (14 of 19). Moreover, an ECC strain co-harboring plasmid-mediated mcr-4.3 and blaNDM-1 has been found. Conclusions This study suggested that there is no overlap between the resistance mechanism of co-resistant ECC strains to carbapenem and colistin. However, the emergence of strain co-harboring plasmid-mediated resistance genes indicated that ECC is a potential carrier for the horizontal spread of carbapenems and colistin resistance.

scholarly journals Molecular characteristics of carbapenem-resistant Acinetobacter spp. from clinical infection samples and fecal survey samples in Southern China

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Si Li ◽  
Xiaonv Duan ◽  
Yuan Peng ◽  
Yongyu Rui
Keyword(s):  
Efflux Pump ◽  
Southern China ◽  
Variable Region ◽  
Carbapenem Resistance ◽  
Resistant Bacteria ◽  
Molecular Characteristics ◽  
Clinical Infection ◽  
High Genetic Diversity ◽  
Carbapenem Resistant ◽  
Opportunistic Bacteria

Abstract Background Carbapenem resistance among Acinetobacter species has become a life-threatening problem. As a last resort in the treatment of gram-negative bacteria infection, resistance to colistin is also a serious problem. The aim of study was to analyze the mechanism of resistance and perform genotyping of carbapenem-resistant Acinetobacter from clinical infection and fecal survey samples in Southern China. Methods One hundred seventy and 74 carbapenem-resistant Acinetobacter were isolated from clinical infection samples and fecal survey samples, respectively. We detected the related genes, including carbapenemase genes (blaKPC, blaIMP, blaSPM, blaVIM, blaNDM, blaOXA-23-like, blaOXA-24/40-like, blaOXA-51-like, and blaOXA-58-like), colistin resistance-related genes (mcr-1, mcr-2, mcr-3, mcr-4, and mcr-5), a porin gene (carO), efflux pump genes (adeA, adeB, adeC, adeI, adeJ, and adeK), mobile genetic element genes (intI1, intI2, intI3, tnpU, tnp513, IS26, ISAba1, and ISAba125), and the integron variable region. Genotyping was analyzed by enterobacterial repetitive intergenic consensus (ERIC)-PCR and dendrogram cluster analysis. Results Among the 244 carbapenem-resistant Acinetobacter, the common carbapenemase-positive genes included the following: blaOXA-51-like, 183 (75.00%); blaOXA-23-like, 174 (71.30%); blaNDM-1, 57 (23.40%); and blaOXA-58-like, 30 (12.30%). The coexistence of mcr-1 and blaNDM-1 in five strains of A. junii was found for the first time. Eleven distinct carO gene variants were detected in 164 (67.20%) strains, and ten novel variants, which shared 92–99% identity with sequences in the Genbank database, were first reported. Efflux system genes were present in approximately 70% of the isolates; adeABC and adeIJK were observed in 76.23 and 72.13%, respectively. Class 1 integrons were detected in 180 (73.80%) strains and revealed that four gene cassette arrays contained 11 distinct genes. The genotyping by ERIC-PCR demonstrated a high genetic diversity of non-baumannii Acinetobacter, and greater than 90% similarity to A. baumannii. Conclusions The blaNDM-1 gene was identified in up to 77% of the carbapenem-resistant Acinetobacter isolated from fecal survey samples, indicating that the gut might be a reservoir of resistant opportunistic bacteria. Intestinal bacteria can be transmitted through the fecal-hand, which is a clinical threat, thus, the monitoring of carbapenem-resistant bacteria from inpatients’ feces should be improved, especially for patients who have been using antibiotics for a long time.

scholarly journals First report of Klebsiella quasipneumoniae harboring blaKPC-2 in Saudi Arabia

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Sharif Hala ◽  
Chakkiath Paul Antony ◽  
Mohammed Alshehri ◽  
Abdulhakeem O. Althaqafi ◽  
Asim Alsaedi ◽  
...  
Keyword(s):  
Public Health ◽  
Saudi Arabia ◽  
Tertiary Hospital ◽  
Whole Genome ◽  
Drug Resistant ◽  
Global Public Health ◽  
Gulf Region ◽  
Carbapenem Resistant ◽  
The Impact ◽  
Klebsiella Spp

Abstract Background Nosocomial infections caused by multi-drug resistant Enterobacteriaceae are a global public health threat that ought to be promptly identified, reported, and addressed accurately. Many carbapenem-resistant Enterobacteriaceae-associated genes have been identified in Saudi Arabia but not the endemic Klebsiella pneumoniae carbapenemases (KPCs), which are encoded by blaKPC-type genes. KPCs are known for their exceptional spreading potential. Methods We collected n = 286 multi-drug resistant (MDR) Klebsiella spp. isolates as part of screening for resistant patterns from a tertiary hospital in Saudi Arabia between 2014 and 2018. Antimicrobial susceptibility testing was carried out using both VITEK II and the broth microdilution of all collected isolates. Detection of resistance-conferring genes was carried out using Illumina whole-genome shotgun sequencing and PacBio SMRT sequencing protocols. Results A Carbapenem-resistant Enterobacteriaceae (CRE) Klebsiella quasipneumoniae subsp. similipneumoniae strain was identified as a novel ST-3510 carrying a blaKPC-2 carbapenemase encoding gene. The isolate, designated as NGKPC-421, was obtained from shotgun Whole Genome Sequencing (WGS) surveillance of 286 MDR Klebsiella spp. clinical isolates. The NGKPC-421 isolate was collected from a septic patient in late 2017 and was initially misidentified as K. pneumoniae. The sequencing and assembly of the NGKPC-421 genome resulted in the identification of a putative ~ 39.4 kb IncX6 plasmid harboring a blaKPC-2 gene, flanked by transposable elements (ISKpn6-blaKPC-2–ISKpn27). Conclusion This is the first identification of a KPC-2-producing CRE in the Gulf region. The impact on this finding is of major concern to the public health in Saudi Arabia, considering that it is the religious epicenter with a continuous mass influx of pilgrims from across the world. Our study strongly highlights the importance of implementing rapid sequencing-based technologies in clinical microbiology for precise taxonomic classification and monitoring of antimicrobial resistance patterns.

scholarly journals Pathogenomic Analysis of a Novel Extensively Drug-Resistant Citrobacter freundii Isolate Carrying a blaNDM-1 Carbapenemase in South Africa

Pathogens ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 89 ◽  
Author(s):  
Yogandree Ramsamy ◽  
Koleka P. Mlisana ◽  
Daniel G. Amoako ◽  
Mushal Allam ◽  
Arshad Ismail ◽  
...  
Keyword(s):  
South Africa ◽  
Acquired Resistance ◽  
Carbapenem Resistance ◽  
Illumina Miseq ◽  
Tertiary Hospital ◽  
Phylogenomic Analysis ◽  
Citrobacter Freundii ◽  
Class 1 Integron ◽  
Pathogenic Potential ◽  
Carbapenem Resistant

Pathogenomic analysis was performed on a novel carbapenem-resistant Citrobacter freundii isolate (H2730R) from a rectal swab of an adult male patient admitted to a tertiary hospital, Durban, South Africa. H2730R was identified using selective media and API 20e kit. Confirmatory identification and antibiotic susceptibility testing were performed using the VITEK II. H2730R was whole-genome sequenced on the Illumina MiSeq platform. H2730R was resistant to all tested antibiotics except tigecycline and was defined as ST498 by the C. freundii multilocus sequence typing (MLST) database. The estimated pathogenic potential predicted a higher probability (Pscore ≈ 0.875), supporting H2730R as a human pathogen. H2730R harbored 25 putative acquired resistance genes, 4 plasmid replicons, 4 intact prophages, a class 1 integron (IntI1), 2 predominant insertion sequences (IS3 and IS5), numerous efflux genes, and virulome. BLASTn analysis of the blaNDM-1 encoding contig (00022) and its flanking sequences revealed the blaNDM-1 was located on a plasmid similar to the multireplicon p18-43_01 plasmid reported for the spread of carbapenem resistance in South Africa. Phylogenomic analysis showed clustering of H2730R with CF003/CF004 strains in the same clade, suggesting a possible association between C. freundii strains/clones. Acquiring the p18-43_01 plasmid containing blaNDM-1, the diversity, and complex resistome, virulome, and mobilome of this pathogen makes its incidence very worrying regarding mobilized resistance. This study presents the background genomic information for future surveillance and tracking of the spread of carbapenem-resistant Enterobacteriaceae in South Africa.

scholarly journals Characterization of IncHI1B Plasmids Encoding Efflux Pump TmexCD2-ToprJ2 in Carbapenem-Resistant Klebsiella variicola, Klebsiella quasipneumoniae, and Klebsiella michiganensis Strains

2021 ◽  
Vol 12 ◽  
Author(s):  
Yujiao Wang ◽  
Bo Zhu ◽  
Min Liu ◽  
Xiutao Dong ◽  
Jianping Ma ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Efflux Pump ◽  
Resistance Mechanism ◽  
Carbapenem Resistance ◽  
Health Concern ◽  
Close Monitoring ◽  
Carbapenem Resistant ◽  
Resistance Nodulation Division ◽  
Tertiary Hospitals ◽  
Severe Infections

Tigecycline serves as one of the last-resort antibiotics to treat severe infections caused by carbapenem-resistant Enterobacterales. Recently, a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster, TmexCD1-ToprJ1, and its variants, TmexCD2-ToprJ2 and TmexCD3-ToprJ3, encoding tetracyclines and tigecycline resistance, were revealed. In this study, we reported three TmexCD2-ToprJ2-harboring Klebsiella species strains, collected from two teaching tertiary hospitals in China, including one K. quasipneumoniae, one K. variicola, and one K. michiganensis. The three strains were characterized by antimicrobial susceptibility testing (AST), conjugation assay, WGS, and bioinformatics analysis. AST showed that K. variicola and K. quasipneumoniae strains were resistant to tigecycline with MIC values of 4μg/ml, whereas the K. michiganensis was susceptible to tigecycline with an MIC value of 1μg/ml. The TmexCD2-ToprJ2 clusters were located on three similar IncHI1B plasmids, of which two co-harbored the metallo-β-lactamase gene blaNDM-1. Conjugation experiments showed that all three plasmids were capable of self-transfer via conjugation. Our results showed, for the first time, that this novel plasmid-mediated tigecycline resistance mechanism TmexCD2-ToprJ2 has spread into different Klebsiella species, and clinical susceptibility testing may fail to detect. The co-occurrence of blaNDM-1 and TmexCD2-ToprJ2 in the same plasmid is of particular public health concern as the convergence of “mosaic” plasmids can confer both tigecycline and carbapenem resistance. Its further spread into other clinical high-risk Klebsiella clones will likely exacerbate the antimicrobial resistance crisis. A close monitoring of the dissemination of TmexCD-ToprJ encoding resistance should be considered.

scholarly journals Predominance of Acinetobacter spp., Harboring the blaIMP Gene, Contaminating the Hospital Environment in a Tertiary Hospital in Mwanza, Tanzania: A Cross-Sectional Laboratory-Based Study

Pathogens ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 63
Author(s):  
Vitus Silago ◽  
Eveline C. Mruma ◽  
Betrand Msemwa ◽  
Conjester I. Mtemisika ◽  
Shukurani Phillip ◽  
...  
Keyword(s):  
Carbapenem Resistance ◽  
Tertiary Hospital ◽  
Hospital Environment ◽  
Pcr Assay ◽  
Cross Sectional ◽  
Middle Income ◽  
Carbapenem Resistant ◽  
Multiplex Pcr Assay ◽  
Genes Encoding ◽  
Acinetobacter Spp

Data on colonization and hospital contamination of carbapenem-resistant Gram-negative bacteria (CR-GNB) are limited in low- and middle-income countries. We designed this study to determine the prevalence and co-existence of carbapenemase genes among CR-GNB isolated from clinical, colonization, and hospital environmental samples at a tertiary hospital in Mwanza, Tanzania. The modified Hodge test (MHT), the combined disk test (CDT), and the double-disk synergy test (DDST) were used for the phenotypic detection of carbapenemases. A multiplex PCR assay was used to detect blaIMP and blaKPC, and a singleplex PCR assay was used to detect blaOXA-48. Data were analyzed by STATA version 13.0. Overall, 68.8% (44/64) of the CR-GNB had at least one phenotype by phenotypic methods, whereby 60.9% (39/64) were both CDT and DDST positive and 31.3% (20/64) were MHT positive. A total of 23/64 (35.9%) had at least one of the genes tested with the predominance of blaIMP (91.3%; 21/23). In addition, 47.7% (21/44) of the CR-GNB phenotypes had at least one gene. Around 47.8% (11/23) of the CR-GNB carried multiple genes encoding for carbapenem resistance, with the maximum co-existence of blaIMP/blaKPC/blaOXA-48 (45.5%; 5/11). The majority of carbapenem-resistant genes were detected in Acinetobacter spp. (82.6%; 19/23) and isolated from bed swabs (69.6%; 16/23). Acinetobacter spp. carrying the blaIMP gene predominantly contaminated the hospital environment. Therefore, we recommend routine decontamination of inanimate hospital surfaces, including patient beds.

scholarly journals Characterizing clinical carbapenem-resistant Klebsiella pneumoniae  phenotypes and genomic information reveals its molecular epidemiology

2019 ◽  
Author(s):  
Xiaoling Yu ◽  
Wen Zhang ◽  
Zhiping Zhao ◽  
Chengsong Ye ◽  
Shuyan Zhou ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Pathogenic Bacteria ◽  
Efflux Pump ◽  
Carbapenem Resistance ◽  
Snp Markers ◽  
Nucleotide Polymorphisms ◽  
Phenotypic Resistance ◽  
Carbapenem Resistant ◽  
Oxford Nanopore ◽  
Long Read

Abstract The enhancing incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP)-mediated infections in Mengchao Hepatobiliary Hospital of Fujian Medical University in 2017 promoted this investigation to study gene phenotypes and resistance genes of emergence regarding the CRKP strains. In current study, seven inpatients are enrolled in the hospital with complete treatments. The carbapenem-resistant K. pneumoniae whole genome is sequenced using MiSeq short-read and Oxford Nanopore long-read sequencing technology. Prophages are identified to assess genetic diversity within CRKP genomes. The investigation encompassed eight CRKP strains that collected from the patients enrolled as well as the environment, which illustrate that bla KPC-2 is responsible for phenotypic resistance in six CRKP strains that K . pneumoniae sequence type (ST-11) is inferred. The plasmid with IncR, ColRNAI and pMLST type with IncF[F33:A-:B-] co-exist in all ST-11 with KPC-2-producing CRKP strains. Along with carbapenemases, all K. pneumoniae strains harbor two or three extended spectrum β-lactamase (ESBL)-producing genes. F osA gene is detected amongst all the CRKP strains. The oqxA and oqxB expressions in CRKP strains may lead to carbapenem resistance since antimicrobials are expelled from pathogenic bacteria by efflux pump. The single nucleotide polymorphisms (SNP) markers are indicated and validated among all CRKP strains, providing valuable clues for distinguishing carbapenem-resistant strains from conventional K. pneumoniae .

The Predominance of Strain Replacement Among Enterobacteriaceae Pairs With Emerging Carbapenem Resistance During Hospitalization

2020 ◽  
Vol 221 (Supplement_2) ◽  
pp. S215-S219
Author(s):  
Baixing Ding ◽  
Zhen Shen ◽  
Xiaohua Qin ◽  
Yang Yang ◽  
Xiaogang Xu ◽  
...  
Keyword(s):  
Antimicrobial Therapy ◽  
Gel Electrophoresis ◽  
Carbapenem Resistance ◽  
Tertiary Hospital ◽  
Pulsed Field Gel Electrophoresis ◽  
Pulsed Field ◽  
Carbapenem Resistant ◽  
Sequence Types ◽  
Carbapenem Resistant Enterobacteriaceae

Abstract Isolates of Enterobacteriaceae collected from the same patient can lose carbapenem susceptibility during antimicrobial therapy, but little attention has been given to how this conversion takes place. In the current study, we retrospectively analyzed microbiological and clinical data from patients with enterobacterial infections at a tertiary hospital in Shanghai, China. After screening 4795 patients and 7120 Enterobacteriaceae isolates over the 3-year study period, we found the change from carbapenem susceptible to carbapenem resistant in 41 pairs of isolates, of which 35 pairs (85.4%) were K. pneumoniae and 25 (61.0%) were from the same anatomic sites. Thirty-six isolate pairs showed different pulsed-field gel electrophoresis patterns between the carbapenem-susceptible and the corresponding resistant strain, and 5 pairs displayed identical pulsed-field gel electrophoresis patterns. Thirty-three (91.7%) of the 36 pairs of Enterobacteriaceae isolates were carbapenem-resistant K. pneumoniae with blaKPC-2, and 28 pairs (90.3%) of K. pneumoniae isolates had different sequence types (STs), with ST11 the most common ST found in carbapenem-resistant K. pneumoniae isolates. Forty of the 41 patients had received antimicrobial therapy such as carbapenems, cephalosporins, and fluoroquinolones, before the isolation of carbapenem-resistant Enterobacteriaceae. These results demonstrated that strain replacement is the main cause of emerging carbapenem resistance in Enterobacteriaceae during hospitalization. The loss of carbapenem susceptibility was not mainly due to in vivo development of carbapenem resistance.

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