scholarly journals Characterization of Carbapenem-Resistant Acinetobacter baumannii Strains Isolated from Hospitalized Patients in Palestine

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Regeen Handal ◽  
Lulu Qunibi ◽  
Ibrahim Sahouri ◽  
Maha Juhari ◽  
Rula Dawodi ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Single Patient ◽  
Carbapenem Resistant ◽  
Control And Prevention ◽  
Sequence Types

The American Centers for Disease Control and Prevention (CDC) recognizes Acinetobacter baumannii as a source of global outbreaks and epidemics especially due to its increasing resistance to commercially available antibiotics. In this study, 69 single patient multidrug resistant isolates collected from all over Palestine, except Gaza, were studied. All the isolates were resistant to all the β–lactam antibiotics including the carbapenems. Of the 69 isolates, 82.6% were positive for blaOXA-23, 14.5% were positive for blaOXA-24, and 3% were positive for blaOXA-58. None were positive for blaOXA-143 and blaOXA-235. In addition, 5.8% and 0% were positive for blaNDM and blaKPC, respectively. Of the 69 isolates, none were positive for the aminoglycoside aphA6 gene while 93% were positive for the aphA1 gene. The acetyltransferases aacC1 and aacA4 genes tested positive in 22% and 13% of the isolates, respectively. The ompA biofilm-producing virulence gene was detected in all isolates. Finally, Multilocus Sequence Typing (MLST) of 13 isolates revealed that more than one strain of A. baumannii was circulating in Palestinian hospitals as results revealed that 7 isolates were of ST208, 2 isolates ST218, 1 isolate ST231, 1 isolate ST348, and 2 new Sequence Types. The detection of these drug resistant pathogens is a reminder of the importance of active surveillance for resistant bacteria in order to prevent their spread in hospital settings.

scholarly journals Antimicrobial activity of a repurposed harmine-derived compound on extensively drug-resistant Acinetobacter baumannii clinical isolates

2021 ◽  
Author(s):  
Anke Breine ◽  
Megane Van Gysel ◽  
Mathias Elsocht ◽  
Clemence Whiteway ◽  
Chantal Philippe ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Reference Strain ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Antibiotic Resistant ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Resistant Strains ◽  
High Degree

Synopsis Objectives: The spread of antibiotic resistant bacteria is an important threat for human healthcare. Acinetobacter baumannii bacteria impose one of the major issues, as multidrug- to pandrug-resistant strains have been found, rendering some infections untreatable. In addition, A. baumannii is a champion in surviving in harsh environments, being capable of resisting to disinfectants and to persist prolonged periods of desiccation. Due to the high degree of variability found in A. baumannii isolates, the search for new antibacterials is challenging. Here, we screened a compound library to identify compounds active against recent isolates of A. baumannii bacteria. Methods: A repurposing drug screen was undertaken to identify A. baumannii growth inhibitors. One hit was further characterized by determining its IC50 and testing its activity on 43 recent clinical A. baumannii isolates, amongst which 40 are extensively drug- and carbapenem-resistant strains. Results: The repurposing screen led to the identification of a harmine-derived compound, called HDC1, which proved to have bactericidal activity on the multidrug-resistant AB5075-VUB reference strain with an IC50 of 48.23 [mu]M. In addition, HDC1 impairs growth of all 43 recent clinical A. baumannii isolates. Conclusions: We identified a compound with inhibitory activity on all tested, extensively drug-resistant clinical A. baumannii isolates.

scholarly journals Treatment of Multi-Drug Resistant Gram-Negative Bacterial Pathogenic Infections

2020 ◽  
Vol 14 (3) ◽  
pp. 1639-1647
Author(s):  
Wardah Mohammad Akram ◽  
Godfred Antony Menezes ◽  
Nida Abbas ◽  
Wasim Ahmad ◽  
Ahmed Mohamed Ahmed
Keyword(s):  
Acinetobacter Baumannii ◽  
Bacterial Infections ◽  
Empirical Therapy ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Gram Negative ◽  
Carbapenem Resistant ◽  
Review Management ◽  
Emergence Of Resistance ◽  
Novel Therapeutic

The multidrug-resistant Gram-negative bacteria (MDR-GNB) infections in severely infected patients present numerous difficulties in terms of treatment failure where antibiotics cannot arrest such drug resistant bacteria. Based on the patient’s medical history and updated microbiological epidemiology data, an effective empirical treatment remains critical for optimal results to safeguard human health. The aim of this manuscript is to review management of MDR-Gram negative pathogenic bacterial infections. Quick diagnosis and narrow antimicrobial spectrum require rapid and timely diagnosis and effective laboratories in accordance with antimicrobial stewardship (AS) principles. Worldwide, there is an increased emergence of Carbapenem-resistant Enterobacteriaceae (CRE), Pseudomonas aeruginosa, and Acinetobacter baumannii. Recently, novel therapeutic options, such as meropenem/vaborbactam, ceftazidime/avibactam, ceftolozane/tazobactam, eravacycline and plazomicin became accessible to effectively counteract severe infections. Optimally using these delays the emergence of resistance to novel therapeutic agents. Further study is required, however, due to uncertainties in pharmacokinetic/pharmacodynamics optimization of dosages and therapeutic duration in severely ill patients. The novel agents should be verified for (i) action on carbapenem resistant Acinetobacter baumannii; (ii) action on CRE of β-lactam/β-lactamase inhibitors dependence on type of carbapenemase; (iii) emergence of resistance to novel antibacterials and dismiss selective pressure promoting development of resistance. Alternative treatments should be approached alike phage therapy or antibacterial peptides. The choice of empirical therapy is complicated by antibiotic resistance and can be combated by accurate antibiotic and their combinations usage, which is critical to patient survival. Noteworthy are local epidemiology, effective teamwork and antibiotic stewardship to guarantee that medications are utilized properly to counter the resistance.

scholarly journals Characterization of Extremely Drug-Resistant and Hypervirulent Acinetobacter baumannii AB030

Antibiotics ◽  
2020 ◽  
Vol 9 (6) ◽  
pp. 328
Author(s):  
Manu Singh ◽  
P. Malaka De Silva ◽  
Yasser Al-Saadi ◽  
Jacek Switala ◽  
Peter C. Loewen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Comparative Genomics ◽  
Acinetobacter Baumannii ◽  
Bacterial Pathogen ◽  
Multidrug Resistant ◽  
Mobile Elements ◽  
Drug Resistant

Acinetobacter baumannii is an important nosocomial bacterial pathogen. Multidrug-resistant isolates of A. baumannii are reported worldwide. Some A. baumannii isolates display resistance to nearly all antibiotics, making treatment of infections very challenging. As the need for new and effective antibiotics against A. baumannii becomes increasingly urgent, there is a need to understand the mechanisms of antibiotic resistance and virulence in this organism. In this work, comparative genomics was used to understand the mechanisms of antibiotic resistance and virulence in AB030, an extremely drug-resistant and hypervirulent strain of A. baumannii that is a representative of a recently emerged lineage of A. baumannii International Clone V. In order to characterize AB030, we carried out a genomic and phenotypic comparison with LAC-4, a previously described hyper-resistant and hypervirulent isolate. AB030 contains a number of antibiotic resistance- and virulence-associated genes that are not present in LAC-4. A number of these genes are present on mobile elements. This work shows the importance of characterizing the members of new lineages of A. baumannii in order to determine the development of antibiotic resistance and virulence in this organism.

scholarly journals Subtypes, resistance and virulence platforms in extended-drug resistant Acinetobacter baumannii Romanian isolates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Irina Gheorghe ◽  
Ilda Czobor Barbu ◽  
Marius Surleac ◽  
Ionela Sârbu ◽  
Laura Ioana Popa ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Control Measures ◽  
Drug Resistant ◽  
Infection Control Measures ◽  
Carbapenem Resistant ◽  
Ambulatory Patients ◽  
Severe Infections ◽  
Healthcare Associated ◽  
Sequence Types

AbstractAcinetobacter baumannii has emerged worldwide as a dominant pathogen in a broad range of severe infections, raising an acute need for efficient antibacterials. This is the first report on the resistome and virulome of 33 extended drug-resistant and carbapenem-resistant A. baumannii (XDR CRAB) strains isolated from hospitalized and ambulatory patients in Bucharest, Romania. A total of 33 isolates were collected and analyzed using phenotypic antibiotic susceptibility and conjugation assays, PCR, whole-genome sequencing (WGS), pulsed-field gel electrophoresis (PFGE) and MultiLocus Sequence Typing (MLST). All isolates were extensively drug-resistant (XDR), being susceptible only to colistin. The carbapenem resistance was attributed by PCR mainly to blaOXA-24 and blaOXA-23 genes. PFGE followed by MLST analysis demonstrated the presence of nine pulsotypes and six sequence types. WGS of seven XDR CRAB isolates from healthcare-associated infections demonstrated the high diversity of resistance genes repertoire, as well as of mobile genetic elements, carrying ARGs for aminoglycosides, sulphonamides and macrolides. Our data will facilitate the understanding of resistance, virulence and transmission features of XDR AB isolates from Romanian patients and might be able to contribute to the implementation of appropriate infection control measures and to develop new molecules with innovative mechanisms of action, able to fight effectively against these bugs, for limiting the spread and decreasing the infection rate and mortality.

scholarly journals Detection of Several Carbapenems Resistant and Virulence Genes in Classical and Hyper-virulent Strains of Klebsiella pneumoniae Isolated from Hospitalized Neonates and Adults in Khartoum

2020 ◽  
Author(s):  
Aalaa Mahgoub Albasha ◽  
Esraa Hassan Osman ◽  
Saga Abd Alhalim ◽  
Elianz Alshaib ◽  
Leena Al-Hassan ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Klebsiella Pneumoniae ◽  
Nosocomial Infections ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Multidrug Resistant ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Extensively Drug Resistant ◽  
Virulent Strains

Abstract Objective Klebsiella pneumoniae (K. pneumoniae) involves both community-acquired and nosocomial infections. It is responsible for a wide variety of infections, including infections of the urinary tract, pneumonia, bacteremia, meningitis, wound infection and purulent abscesses. We constructed this study to detect several carbapenems resistant and virulence genes in classical and hyper-virulent strains of K. pneumoniae isolated from hospitalized neonates and adults in Khartoum state. Results Seventy percent of the isolates were resistant to ceftazidime, 18(30%) to ciprofloxacin, 23(38.3%) to chloramphenicol, 24(40%) to gentamicin and 8% to imipenem, 35% were multidrug-resistant, and 7% extensively drug-resistant, all blood isolates (n=14) were resistant to ceftazidime. entB was the most predominant virulence gene (93.3%), followed by mrkD (78.3%), kfu (60%), K2 (51.7%), magA (18.3%) and rmpA (5%). blaOXA-48 was the most predominant carbapenem-resistant gene (68.3%), followed by blaNDM (10%), blaKPC (8.3%), and blaIMP (3.3%). Eight hyper-virulent strains were positive for blaOXA-48 and two for blaNDM genes.

scholarly journals Distribution and Molecular Characterization of Acinetobacter baumannii International Clone II Lineage in Japan

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Mari Matsui ◽  
Masato Suzuki ◽  
Masahiro Suzuki ◽  
Jun Yatsuyanagi ◽  
Masanori Watahiki ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Content Type ◽  
Low Prevalence ◽  
Prevalent Species ◽  
Sequence Types ◽  
Insight Into

ABSTRACTMultidrug-resistant (MDR)Acinetobacterspp. have been globally disseminated in association with the successful clonal lineageAcinetobacter baumanniiinternational clone II (IC II). Because the prevalence of MDRAcinetobacterspp. in Japan remains very low, we characterized allAcinetobacterspp. (n= 866) from 76 hospitals between October 2012 and March 2013 to describe the entire molecular epidemiology ofAcinetobacterspp. The most prevalent species wasA. baumannii(n= 645; 74.5%), withA. baumanniiIC II (n= 245) accounting for 28.3% of the total. Meropenem-resistant isolates accounted for 2.0% (n= 17) and carried ISAba1-blaOXA-23-like(n= 10),blaIMP(n= 4), or ISAba1-blaOXA-51-like(n= 3). Multilocus sequence typing of 110 representativeA. baumanniiisolates revealed the considerable prevalence of domestic sequence types (STs).A. baumanniiIC II isolates were divided into the domestic sequence type 469 (ST469) (n= 18) and the globally disseminated STs ST208 (n= 14) and ST219 (n= 4). ST469 isolates were susceptible to more antimicrobial agents, while ST208 and ST219 overproduced the intrinsic AmpC β-lactamase.A. baumanniiIC II and someA. baumanniinon-IC II STs (e.g., ST149 and ST246) were associated with fluoroquinolone resistance. This study revealed that carbapenem-susceptibleA. baumanniiIC II was moderately disseminated in Japan. The low prevalence of acquired carbapenemase genes and presence of domestic STs could contribute to the low prevalence of MDRA. baumannii. A similar epidemiology might have appeared before the global dissemination of MDR epidemic lineages. In addition, fluoroquinolone resistance associated withA. baumanniiIC II may provide insight into the significance ofA. baumanniiepidemic clones.

scholarly journals Characterization of CTX-M-15-Klebsiella pneumoniae from inpatients and outpatients of a teaching hospital

F1000Research ◽  
2021 ◽  
Vol 10 ◽  
pp. 444
Author(s):  
Muzaheed Muzaheed ◽  
Naveed Sattar Shaikh ◽  
Saeed Sattar Shaikh ◽  
Sadananda Acharya ◽  
Shajiya Sarwar Moosa ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Hospital Setting ◽  
Multidrug Resistant ◽  
Influential Factor ◽  
Detection Methods ◽  
Clinical Samples ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Drug Resistant Bacteria

Background  The presence of Extended-spectrum β-lactamase (ESBL) positive bacteria in hospital setting is an aggravating influential factor for hospitalized patients, and its consequences may be hazardous. Therefore, there is a need for rapid detection methods for newly emerging drug-resistant bacteria. This study was aimed at the molecular characterization of ESBL-positive Klebsiella pneumoniae isolates recovered from clinical samples.   Methods  A total of 513 K. pneumoniae isolates were obtained from various clinical samples during June 2019 to May 2020. The collected isolates were investigated for antimicrobial susceptibility (antibiogram), and PCR and DNA sequencing were performed to analyse the ESBL genes.   Results  Among the 513 isolates, as many as 359 (69.9%) were ESBL producers and 87.5% were multi-drug resistant, while none had resistance to imipenem. PCR scored 3% blaTEM, 3% blaSHV, and 60% blaCTX-M-15 genes for the tested isolates.   Conclusion  The study showed that CTX-M-15 was the major prevalent ESBL type among the isolates. Additionally, all the isolates were susceptible to carbapenems. Screening and detection of ESBL tests are necessary among all isolates from the enterobacteriaceae family in routine microbiology laboratory to prevent associated nosocomial infections. A larger study is essential to understand molecular epidemiology of ESBL producing organisms to minimize morbidities due to these multidrug resistant organisms.

scholarly journals Expression of Efflux Pumps, Porins and Genotypic Insight Into the Carbapenem Resistance in Acinetobacter Baumannii

2021 ◽  
Author(s):  
Alka Hasani ◽  
Abolfazl vahhabi ◽  
Mohammad Ahangarzadeh Rezaee ◽  
Behzad Baradaran ◽  
Akbar Hasani ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Carbapenem Resistance ◽  
Standard Of Care ◽  
Efflux Pumps ◽  
Multidrug Resistant ◽  
Simultaneous Occurrence ◽  
Drug Resistant ◽  
Carbapenem Resistant ◽  
Therapeutic Regime ◽  
Drug Resistant Strains

Abstract Background. The emergence of multidrug and extensive drug resistant strains of Acinetobacter baumannii‎ is a multifactorial consequence. Carbapenems, once considered the traditional standard of care for Acinetobacter infections however, are gradually being curtailed from the therapeutic regime due to the emergence of Carbapenem resistant Acinetobacter baumannii‎ (CRAB). Several carbapenem resistant mechanisms have been postulated for the rise of CRAB. This study investigated clinical A.baumannii isolates for the presence and level of expression of enzymatic and non-enzymatic genes, putatively associated with carbapenem resistance and their association with sequence typing. Methods. Uniplex, and Multiplex PCR were performed to identify the presence of oxacillinase (OXA) and metallo β-lactamase (MBLs) genes respectively. The level of expression of efflux pumps (adeB and adeJ) and porins (carO, omp33-36 and oprD) was investigated by Real-time PCR. Results. Of the 112 isolates obtained during this study, 100% were multidrug-resistant and 48.2% were extensive drug-resistant A.baumannii. All CRAB isolates harbored blaOXA−51−like, while, 82.1% and 63.4% of these isolates carried blaOXA−23−like and blaOXA−24/40−like genes, respectively. In contrast, the frequency of metallo β-lactamase genes was comparatively less than the oxacillinase genes. Over-expression of adeB and adeJ was observed in 66% and 42.8% A.baumannii strains respectively, while, decreased expression of carO, omp33-36 and oprD was observed in 75%, 66% and 72.3% strains respectively. Conclusion. Consistent with that reported by others, our study highlights the significant dissemination of the oxacillinase, blaOXA−23−like in CRAB isolates, particularly the simultaneous occurrence of blaOXA−23−like with blaOXA−40. Interestingly, while changes in the expression of efflux pumps and porins were observed nevertheless, more in depth investigation is required to decipher their contribution to carbapenem resistance in these strains.

scholarly journals Characterization of carbapenem-resistant hypervirulent Acinetobacter baumannii strains isolated from hospitalized patients in the mid-south region of China

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Jun Li ◽  
Ting Yu ◽  
Yi Luo ◽  
Jing-Yi Peng ◽  
Yu-Jia Li ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Acinetobacter Baumannii ◽  
High Mortality ◽  
Galleria Mellonella ◽  
Opportunistic Pathogen ◽  
Infection Model ◽  
Carbapenem Resistant ◽  
Blood Specimens ◽  
Sequence Types

Abstract Background Acinetobacter baumannii has traditionally been considered an opportunistic pathogen with low virulence. In this study, we characterized the carbapenem-resistant hypervirulent A. baumannii (CR-hvAB) stains isolated from our hospital in mid-south region of China. Results Blood samples collected between January 2017 and May 2019 were used for virulence experiments and biofilm assays of individual carbapenem-resistant A. baumannii (CR-AB) strains, performed using a Galleria mellonella infection model and crystal violet staining method, respectively. CR-AB isolates that induced high mortality in the G. mellonella infection model were subjected to genotyping, susceptibility testing, and clinical data analysis, and the genetic characterization of these isolates was performed by whole-genome sequencing (WGS). Among the 109 CR-AB clinical strains, the survival rate of G. mellonella larvae infected with 7 (6.4%) CR-AB isolates (number of strains with mortality of 0, 10 and 20% was 4, 1, and 2, respectively), was significantly lower than that of A. baumannii ATCC 19606 (100.0%) and the remaining CR-AB isolates (> 80.0%). Consistent with these results, patients infected with these seven isolates had an average 7-day mortality rate of 42.9%, suggesting that the isolates were CR-hvAB. These seven isolates belonged to four sequence types (STs): ST457, ST195, ST369, and ST2088 (a new ST), and mainly ST457 (n = 4). The results of the biofilm study showed that eight strains had powerful biofilm ability (strong [n = 1] and moderate [n = 7] biofilm producers) including these seven CR-hvAB isolates. Conclusions CR-hvAB isolates that induced a high mortality rate were cloned in our hospital, most of which belonged to ST457; thus, monitoring of these strains, particularly ST457, should be strengthened in the future. Meanwhile, A. baumannii, which was isolated from blood specimens and found to powerful biofilm-forming ability, is a probable hvAB isolate.

Antibacterial and Antibiofilm Effects of Synbiotics against Multidrug-Resistant bacteria: Acinetobacter baumannii and Enterococcus faecalis

2020 ◽  
Author(s):  
Niki Laal-Kargar ◽  
Samaneh Dolatabadi ◽  
Mahnaz Mohtashami
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Multidrug Resistant ◽  
Inhibitory Effect ◽  
Resistant Bacteria ◽  
Dilution Method ◽  
Antibiofilm Activity ◽  
Drug Resistant ◽  
Study Support ◽  
And Control

Abstract Background: Acinetobacter baumannii and Enterocoocus faecalis increase their resistance against antibiotic by producing biofilm. Antibiotic resistance has become a massive public health threat that require novel effective antibacterial and antibiofilm alternatives. The use of probiotics is interested to prevent and control certain infections. The objective of this study was to investigate the antibacterial and antibiofilm property of probiotics and synbiotics against multidrug-resistant A. baumannii and E. faecalis. Methods: The antimicrobial and the antibiofilm activities of cell- free supernatants of four strains of Lactobacillus against 20 clinical multi-drug resistant (MDR) isolates of Acinetobacter baumannii and Enterocoocus faecalis were determined in the presence of 0.3% of sorbitol, raffinose, citrate, trehalose, inulin, and riboflavin using well diffusion agar and micro-dilution method. Results: The cell- free supernatant of L. rhamnosus with citrate and trehalose showed the best antibacterial activity against MDR A. baumannii (28.8±2.1mm, 1.128 μL/mL), and L. rhamnosus with all of prebiotics against MDR E. faecalis (29.8±0 mm, 1.128 μL/mL) compare to probiotic alone. The prebiotics could improve the inhibitory effect of probiotics against the Gram-negative A. baumannii higher than Gram-positive E. faecalis. Biofilm formation was reduced in both pathogens in presence of synbiotics. L. plantarum with riboflavin and L. rhamnosus with or without inulin potently inhibits E. faecalis (50±0.86%) and A. baumannii (75±6.5%) biofilm formation, respectively. Conclusions: The results of current study support the antibiofilm activity of metabolites produced by synbiotics, and suggest their use as suitable adjuvants as well as biocontrol agents for treatment.

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