scholarly journals Phenotypic and genotypic characterization of multidrug-resistant Acinetobacter baumannii isolated in Algerian hospitals

2020 ◽  
Vol 14 (12) ◽  
pp. 1395-1401
Author(s):  
Nabila Benamrouche ◽  
Ourida Lafer ◽  
Lahcen Benmahdi ◽  
Akila Benslimani ◽  
Wahiba Amhis ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Intensive Care ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Phenotypic Characterization ◽  
Resistant Strains ◽  
Almost All ◽  
Encoding Genes ◽  
Phenotypic And Genotypic Characterization

Introduction: The aim of this study was to investigate the drug-resistance and the molecular characterization of carbapenemases, ESBL, and aminoglycoside-modifying enzymes among Acinetobacter baumannii clinical isolates in Algerian hospitals. Methodology: A total of 92 A. baumannii isolates were collected between 2012 and 2016. Antimicrobial susceptibility testings were performed for β-lactams, aminoglycosides, fluoroquinolones, trimethoprim-sulfamethoxazole, rifampicin and colistin. The phenotypic characterization of β-lactamases was investigated. For 30 randomly targeted strains, the carriage of the carbapenemases, ESBL and aminoglycoside-modifying enzymes -encoding genes was determined by PCR. Sequencing was carried out for carbapenemases and ESBL genes. Results: Most of the 92 isolates studied were recovered from hospitalized patients (93.5%) and were mainly from intensive care units (51.1%) and orthopedics (19.6%). The strains were collected primarily from low respiratory tract (33.7%), wounds (23.9%) and urine (16.3%). Multidrug-resistant A. baumannii strains were prevalent (96.7%). High rates of resistance were observed for almost all antibiotics tested (>70%) excluding rifampicin (7.6%) and colistin (5.4%). For the five colistin-resistant strains, MICs ranged between 4 and 128 µg/mL. Positive MBL (83.7%) and ESBL (23.9%) strains were identified. Regarding β-lactams, the blaNDM and both blaSHV and blaCTX-M1 genes were detected in five and two strains respectively. Sequencing of the genes revealed the presence of blaNDM-1, blaCTX-M-15, and blaSHV-33. For aminoglycosides, aac(6’)-Ib, ant(2’’)-I and aph(3’)-VI genes were detected in three, seven and six strains respectively. Conclusions: Here, we report the first co-occurrence of extended-spectrum β-lactamases SHV-33 and CTX-M-15, the carbapenemase NDM-1 and the emergence of colistin-resistant A. baumannii in Algerian hospitals.

scholarly journals Phenotypic Characterization of Extended-Spectrum Beta-Lactamases and Metallo-Beta-Lactamase of Multi Drug Resistant Acinetobacter baumannii Causing Nosocomial Infections in Erbil City

2020 ◽  
Vol 30 (4) ◽  
pp. 51
Author(s):  
Sakar Bakr Smail ◽  
Kamal I. AL-OTRACHI
Keyword(s):  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Phenotypic Characterization ◽  
Multi Drug Resistance ◽  
Beta Lactamase ◽  
Beta Lactamases ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases

Background: Resistance to broad‑spectrum beta‑lactams, mediated by extended‑spectrum beta‑lactamases, and metallo‑beta‑lactamase enzymes, is an increasing problem worldwide. The main aim is to study phenotypic characterization of extended‑spectrum beta‑lactamases and metallo‑beta‑lactamase multidrug resistant Acinetobacter baumannii in Erbil City. Materials and Methods: A total of 112 Acinetobacter baumannii isolations were collected from patients of all age groups from clinical specimens sputum, blood, pus, wound swab, urine and body fluids (Pleural fluid and cerebrospinal fluid) collected from different medical wards and intensive care unit departments of hospitals in Erbil City for a period of one year from march 2018--march 2019. Isolates were tested for the presence of extended‑spectrum beta‑lactamases and metallo‑beta‑lactamase. Detection of extended‑spectrum beta‑lactamases was done by the combined disk diffusion method according to Clinical and Laboratory Standards Institute guidelines, while metallo‑beta‑lactamase was detected by meropenem and imipenem combined with ethylenediaminetetraacetic acid disk method. Results: 25% (28) Acinetobacter baumannii isolates were positive for extended‑spectrum beta‑lactamases, while 100 % (112) were metallo‑beta‑lactamase producers. Conclusion: Acinetobacter baumannii is becoming a global medical challenge due to the emergence of multi-drug resistance. Newer beta lactamase is a matter of concern as they are developing rapidly and lead to treatment failure. Carbapenems are known to be effective therapeutic agents for Acinetobacter baumannii infections and its resistance limits the use to polymyxins and colistin. Several new medicines are still in research and combination of drug therapy is being currently used in the hospitals together with ours to treat multidrug resistant Acinetobacter baumannii infections.

Emergence of carbapenem-resistant Acinetobacter baumannii in hospitals in Pakistan

2014 ◽  
Vol 63 (1) ◽  
pp. 50-55 ◽  
Author(s):  
Badrul Hasan ◽  
Khalida Perveen ◽  
Björn Olsen ◽  
Rabaab Zahra
Keyword(s):  
Drug Resistance ◽  
Acinetobacter Baumannii ◽  
The Other ◽  
New Delhi ◽  
National Surveillance ◽  
Carbapenem Resistant ◽  
Extreme Drug Resistance ◽  
Resistant Strains ◽  
Encoding Genes ◽  
Inhibitor Combination

The emergence of pan-resistance in bacterial pathogens poses a threat to human health. Carbapenem-resistant Acinetobacter baumannii has emerged as a serious challenge, causing nosocomial infection and community-acquired outbreaks in hospitals globally, including in Pakistan. We collected 90 Acinetobacter isolates from patients with secondary or nosocomial infections from different hospitals in Pakistan and screened for carbapenem-resistant strains. Of the 90 isolates, 59 were resistant to carbapenems. Among oxacillinase -encoding genes, bla OXA-51-like was common in all isolates, including in combination with bla OXA-23-like in 14 isolates; however, bla OXA-24-like and bla OXA-58-like were completely absent. Among metallo-β-lactamase-encoding genes, only bla NDM-1 was found in one isolate, while the other three genes, bla IMP, bla VIM and bla SIM, were completely absent. None of the isolates was found to harbour the bla CTX-M gene. The isolates were also tested for susceptibilities to a panel of different antibiotics belonging to several classes. Of all the drugs tested, tigecycline was the most effective with 80 % sensitivity amongst isolates, followed by colistin with 50 % sensitivity. Three categories of resistance were found in these isolates: extreme drug resistance in 26, pan-drug resistance in 19 and multidrug resistance in 87 isolates. The isolates exhibited a high resistance to cephalosporins, trimethoprim–sulfamethoxazole and β-lactam antibiotics, followed by tetracycline and β-lactam/β-lactam inhibitor combination, fluoroquinolone and aminoglycosides. The results show a prominent level of antibiotic-resistance phenotypes in A. baumannii and strongly suggest the need for full-scale national surveillance of carbapenem-resistant A. baumannii with particular emphasis on the newly identified NDM-1 (New Delhi metallo-β-lactamase-1).

scholarly journals Frequency of Adhesive Virulence Factor fimH among the Clinical Isolates of Acinetobacter baumannii in India

2020 ◽  
pp. 12-17
Author(s):  
S. Padmaja ◽  
A. S. Smiline Girija ◽  
J. Vijayashree Priyadharsini
Keyword(s):  
Acinetobacter Baumannii ◽  
Pearson Correlation ◽  
Multidrug Resistant ◽  
New Drugs ◽  
Clinical Isolates ◽  
P Value ◽  
Resistant Strains ◽  
Pearson Correlation Analysis ◽  
Bond Mechanism

The objective of the study was to detect the presence of fimH gene among the drug resistanst strains of Acinetobacter baumannii. fimH gene was found to be associated with a catch bond mechanism which led to better evolution of biofilm formation. Since there are not many studies done with this gene it would be a timely investigation and this study mainly aims in molecular characterization of fimH gene among clinical isolates of A. baumannii. Semi quantitative bio adherent assay was done by the multidrug resistant strains of A. baumannii to find the formation of biofilm. The DNA was extracted with the help of kit and PCR was performed for amplification. Pearson correlation analysis was done to find the existing correlation between the fimH gene and MDR strains of A. baumannii with significant p-value of (<0.05). From the screened 73 genomes of MDR A. baumannii 6.8% showed positive amplicons for the fimH gene which were related to biofilm and porin formation (Fig. 1). Correlation of its existence was high in beta lactamase (100%), cephems (100%), folate (100%) resistant strains, followed by aminoglycosides (80%), carbapenems (60%) and fluoroquinolones (60%) and efflux pumps (20%). In Spite of various measures undertaken to prevent the disease, the prevalence of the pathogen is multiplying. The current study recorded the presence of fimHgene (6.8%) among the clinical isolates of A.baumannii. This gene can be used as a target to develop new drugs and vaccines to combat the menace of A.baumannii infection.

scholarly journals Genetic and Phenotypic Characterization of the Novel Metallo-β-Lactamase NDM-29 From Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Ying Zhu ◽  
Xinmiao Jia ◽  
Peiyao Jia ◽  
Xue Li ◽  
Qiwen Yang
Keyword(s):  
Escherichia Coli ◽  
Illumina Sequencing ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Fitness Cost ◽  
Phenotypic Characterization ◽  
Urine Specimen ◽  
The Novel ◽  
Almost All

Objectives: The New Delhi metallo-β-lactamase (NDM) can hydrolyze almost all clinically available β-lactam antibiotics and has widely spread all over the world. NDM-29, a novel carbapenemase, was discovered in an Escherichia coli (19NC225) isolated from a patient with biliary tract infection in 2019 in China.Methods: Conjugation, transformation, cloning test, fitness cost, PacBio Sequel, and Illumina sequencing were performed to analyze the genetic and phenotypic characterization of blaNDM–29.Results: The susceptibility testing results showed 19NC225 was resistant to cephalosporins, carbapenems, combinations of β-lactam and β-lactamase inhibitors, and levofloxacin. Conjugation and transformation were performed to verify the transferability of NDM-29-encoding plasmid, and cloning test was conducted to prove the function of blaNDM–29 to increase carbapenem resistance. Furthermore, fitness cost test confirmed that the presence of NDM-29 exerts no survival pressure on bacteria. PacBio Sequel and Illumina sequencing were performed to analyze the genetic characterization of 19NC225, which contains two plasmids (pNC225-TEM1B and pNC225-NDM-29). pNC225-NDM-29, exhibiting 99.96% identity and 100% coverage with pNDM-BTR (an IncN1 plasmid from an E. coli in urine specimen from Beijing in 2013), showed responsibility for the multidrug-resistant (MDR) phenotype. Compared with blaNDM–1, blaNDM–29, located on pNC225-NDM-29, carries a G388A (D130N) mutation. The region harboring blaNDM–29 is located in an ISKpn19-based transposon, and two Tn6292 remnants are symmetrically located upstream and downstream of the transposon. The sequence results also indicated several important virulence genes.Conclusion: The findings of the novel carbapenemase NDM-29 could pose a threat to the control of antimicrobial resistance and arouse attention about the mutation of bacteria.

scholarly journals Genotypic and Phenotypic Characterization of Novel Sequence Types of Carbapenem-Resistant Acinetobacter baumannii, With Heterogeneous Resistance Determinants and Targeted Variations in Efflux Operons

2021 ◽  
Vol 12 ◽  
Author(s):  
Srinivasan Vijaya Bharathi ◽  
Manjunath Venkataramaiah ◽  
Govindan Rajamohan
Keyword(s):  
Acinetobacter Baumannii ◽  
Health Care Systems ◽  
Multidrug Resistant ◽  
Phenotypic Characterization ◽  
High Morbidity ◽  
Phenotype Microarray ◽  
Human Pathogens ◽  
Carbapenem Resistant ◽  
Care Systems

Acinetobacter baumannii has emerged as one of the dominant nosocomial human pathogens associated with high morbidity and mortality globally. Increased incidences of carbapenem-resistant A. baumannii (CRAB) have resulted in an enormous socioeconomic burden on health-care systems. Here, we report the genotypic and phenotypic characterization of novel ST1816 and ST128 variants in A. baumannii strains belonging to International clone II (GC2) with capsule types KL1:OCL8 and KL3:OCL1d from India. Sequence analysis revealed the presence of diverse virulome and resistome in these clinical strains, in addition to islands, prophages, and resistance genes. The oxacillinase blaOXA–23detected in the genomic island also highlighted the coexistence of blaOXA–66/blaOXA–98, blaADC73/blaADC–3, and blaTEM–1D in their mobile scaffolds, which is alarming. Together with these resistance-determining enzymes, multidrug efflux transporters also harbored substitutions, with increased expression in CRAB strains. The hotspot mutations in colistin resistance-conferring operons, PmrAB, LpxACD, and AdeRS, were additionally confirmed. Phenotype microarray analysis indicated that multidrug-resistant strains A. baumannii DR2 and A. baumannii AB067 preferred a range of antimicrobial compounds as their substrates relative to the other. To our knowledge, this is the first comprehensive report on the characterization of A. baumannii variants ST1816 and ST128, with different genetic makeup and genome organization. The occurrence of CRAB infections worldwide is a severe threat to available limited therapeutic options; hence, continued surveillance to monitor the emergence and dissemination of such novel ST variants in A. baumannii is imperative.

Sign in / Sign up

Export Citation Format

Share Document