scholarly journals Overexpression of blaOXA-58 Gene Driven by ISAba3 is Associated with Imipenem Resistance in a Clinical Acinetobacter baumannii Isolate from Vietnam

2020 ◽  
Author(s):  
Anh T. Nguyen ◽  
Son C. Pham ◽  
Anh K. Ly ◽  
Chau V.V. Nguyen ◽  
Thanh T. Vu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
Mrna Level ◽  
Pcr Amplification ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Imipenem Resistance ◽  
Very High

AbstractThe aim of this study was to investigate genetic structures and expression of blaOXA-58 gene in five Acinetobacter baumannii clinical isolates recovered from two hospitals in southern Vietnam during 2012-2014. A. baumannii isolates were identified by automated microbiology systems and confirmed by PCR. All isolates were characterized as multidrug resistant by antimicrobials testing using the disk diffusion method. Four imipenem susceptible and one non-susceptible isolates (MIC > 32 μg.ml−1) were identified by E-test. PCR amplification of blaOXA-58 gene upstream and downstream sequences revealed the presence of ISAba3 at both locations in one multidrug resistant isolate. Semi quantitation of blaOXA-51 and blaOXA-58 gene expression was performed by the 2−ΔΔCt method. The blaOXA-51 gene expression of five isolates showed little difference but the isolate bearing ISAba3-blaOXA-58-ISAba3 exhibited significant higher blaOXA-58 mRNA level. Higher β-lactamases activity in periplasmic than cytoplasmic fraction was found in most isolates. The isolate overexpressing blaOXA-58 gene possessed very high periplasmic enzyme activity. In conclusion, the A. baumannii isolate bearing ISAba3-blaOXA-58 gene exhibited high resistance to imipenem, corresponding to an overexpression of blaOXA-58 gene and very high periplasmic β-lactamases activity.

scholarly journals Overexpression of blaOXA-58 Gene Driven by ISAba3 Is Associated with Imipenem Resistance in a Clinical Acinetobacter baumannii Isolate from Vietnam

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Anh T. Nguyen ◽  
Son C. Pham ◽  
Anh K. Ly ◽  
Chau V. V. Nguyen ◽  
Thanh T. Vu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Acinetobacter Baumannii ◽  
Mrna Level ◽  
Pcr Amplification ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Imipenem Resistance ◽  
Very High

The aim of this study was to investigate genetic structures and expression of blaOXA-58 gene in five Acinetobacter baumannii clinical isolates recovered from two hospitals in southern Vietnam during 2012-2014. A. baumannii isolates were identified by automated microbiology systems and confirmed by PCR. All isolates were characterized as multidrug resistant by antimicrobial testing using the disk diffusion method. Four imipenem susceptible and one nonsusceptible isolates (MIC>32 μg·ml-1) were identified by E-test. PCR amplification of blaOXA-58 gene upstream and downstream sequences revealed the presence of ISAba3 at both locations in one multidrug-resistant isolate. Semiquantitation of blaOXA-51 and blaOXA-58 gene expression was performed by the 2-ΔΔCt method. The blaOXA-51 gene expression of five isolates showed little difference, but the isolate bearing ISAba3-blaOXA-58-ISAba3 exhibited significantly higher blaOXA-58 mRNA level. Higher β-lactamases activity in periplasmic than cytoplasmic fraction was found in most isolates. The isolate overexpressing blaOXA-58 gene possessed very high periplasmic enzyme activity. In conclusion, the A. baumannii isolate bearing ISAba3-blaOXA-58 gene exhibited high resistance to imipenem, corresponding to an overexpression of blaOXA-58 gene and very high periplasmic β-lactamase activity.

scholarly journals Colistin and Carbapenem-Resistant Acinetobacter baumannii Aci46 in Thailand: Genome Analysis and Antibiotic Resistance Profiling

Antibiotics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1054
Author(s):  
Nalumon Thadtapong ◽  
Soraya Chaturongakul ◽  
Sunhapas Soodvilai ◽  
Padungsri Dubbs
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Antibiotic Resistance Genes ◽  
Carbapenem Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Whole Genome ◽  
Disk Diffusion Method ◽  
Genome Data ◽  
Carbapenem Resistant

Resistance to the last-line antibiotics against invasive Gram-negative bacterial infection is a rising concern in public health. Multidrug resistant (MDR) Acinetobacter baumannii Aci46 can resist colistin and carbapenems with a minimum inhibitory concentration of 512 µg/mL as determined by microdilution method and shows no zone of inhibition by disk diffusion method. These phenotypic characteristics prompted us to further investigate the genotypic characteristics of Aci46. Next generation sequencing was applied in this study to obtain whole genome data. We determined that Aci46 belongs to Pasture ST2 and is phylogenetically clustered with international clone (IC) II as the predominant strain in Thailand. Interestingly, Aci46 is identical to Oxford ST1962 that previously has never been isolated in Thailand. Two plasmids were identified (pAci46a and pAci46b), neither of which harbors any antibiotic resistance genes but pAci46a carries a conjugational system (type 4 secretion system or T4SS). Comparative genomics with other polymyxin and carbapenem-resistant A. baumannii strains (AC30 and R14) identified shared features such as CzcCBA, encoding a cobalt/zinc/cadmium efflux RND transporter, as well as a drug transporter with a possible role in colistin and/or carbapenem resistance in A. baumannii. Single nucleotide polymorphism (SNP) analyses against MDR ACICU strain showed three novel mutations i.e., Glu229Asp, Pro200Leu, and Ala138Thr, in the polymyxin resistance component, PmrB. Overall, this study focused on Aci46 whole genome data analysis, its correlation with antibiotic resistance phenotypes, and the presence of potential virulence associated factors.

Antibiotic Resistance Patterns and Molecular Typing of Acinetobacter Baumannii Strains Isolated from Burn Patients in Iran

2018 ◽  
Author(s):  
Fahimeh Nourbakhsh ◽  
Elaheh Tajbakhsh ◽  
Dana Daneshmand ◽  
Samaneh Borooni ◽  
Vajiheh Nourbakhsh
Keyword(s):  
Antibiotic Resistance ◽  
Acinetobacter Baumannii ◽  
Molecular Typing ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Burn Patients ◽  
Disk Diffusion Method ◽  
Burn Center ◽  
Antibiotic Resistance Pattern

Background and Aims: Acinetobacter baumannii is an important multidrug-resistant opportunistic pathogen frequently causing various nosocomial infections and is a serious threat to burn patients. These infections are usually caused by the outbreak strains. The aim of this study was to show antibiotic resistance pattern and molecular typing of A.baumannii genes isolates collected from burn patients and also distribution of different types of burn patients. Materials and Methods: In this study, 307 different strains were detected. Totally 100 A.baumannii strain was selected in burn center of Isfahan hospital. Antibiotic resistance pattern was determined by disk diffusion method (Kirby Bauer). The presence of genes coding in antibiotic resistance were analyzed by using M-PCR method. The standard strains of Escherichia coli ATCC 25922 and A. baumannii ATCC 19606 were used as negative and positive controls. Results: The antibiotic resistance pattern for A.baumannii showed high resistance for ciprofloxacin, ceftazidime, and tetracycline with frequency of 82.5%, 75.3%, 72%, respectively. Moreover, the most sensitive antibiotics were chloramphenicol, and nitrofurantoin with the resistance frequency of 3.9% and 2.8%. CITM (91.1%) was the highest detected gene. Conclusions: High prevalence of antibiotic resistance pattern among A.baumannii isolated from burn center hospitals indicates the important role of multidrug resistant isolates.

Antibiotic Resistance Patterns and a Survey of Metallo-β-Lactamase Genes Including bla-IMP and bla-VIM Types in Acinetobacter baumannii Isolated from Hospital Patients in Tehran

Chemotherapy ◽  
2016 ◽  
Vol 61 (5) ◽  
pp. 275-280 ◽  
Author(s):  
Samira Aghamiri ◽  
Nour Amirmozafari ◽  
Jalil Fallah Mehrabadi ◽  
Babak Fouladtan ◽  
Mojtaba Hanafi Abdar
Keyword(s):  
Acinetobacter Baumannii ◽  
Antibiotic Sensitivity ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Antimicrobial Sensitivity ◽  
Hospital Patients ◽  
Resistance Patterns ◽  
Pcr Assays ◽  
Etiological Agents

Background: Metallo-β-lactamases (MBLs) producing strains of Acinetobacter baumannii are serious etiological agents of hospital infections worldwide. Among the β- lactams, carbapenems are the most effective antibiotics used against A. baumannii. However, resistance to these drugs among clinical strains of A. baumannii has been increasing in recent years. In this study, the antimicrobial sensitivity patterns of A. baumannii strains isolated from eleven different hospitals in Tehran, Iran, and the prevalence of MBL genes (bla-VIM and bla-IMP) were determined. Method: During a period of 5 months, 176 isolates of A. baumannii were collected from different clinical specimens from hospitalized patients in Tehran. All isolates were confirmed by biochemical methods. The isolates were tested for antibiotic sensitivity by the Kirby-Bauer disk diffusion method. Following minimum inhibitory concentration determination, imipenem-resistant isolates were further tested for MBL production by the double disk synergy test (DDST) method. PCR assays were performed for the detection of the MBL genes bla-IMP and bla-VIM. Results: The DDST phenotypic method indicated that among the 169 imipenem-resistant isolates, 165 strains were MBL positive. The PCR assays revealed that 63 of the overall isolates (36%) carried the bla-VIM gene and 70 strains (40%) harbored bla-IMP. Conclusions: It is obvious that nosocomial infections associated with multidrug-resistant Acinetobacter spp. are on the rise. Therefore, the determination of antibiotic sensitivity patterns and screening for MBL production among A. baumannii isolates is important for controlling clinical Acinetobacter infections.

scholarly journals Dissemination of Class 1, 2 and 3 Integrons among Different Multidrug Resistant Isolates of Acinetobacter baumannii in Tehran Hospitals, Iran

2011 ◽  
Vol 60 (2) ◽  
pp. 169-174 ◽  
Author(s):  
MOROVAT TAHERIKALANI ◽  
ABBAS MALEKI ◽  
NOURKHODA SADEGHIFARD ◽  
DELBAR MOHAMMADZADEH ◽  
SETAREH SOROUSH ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Exact Role ◽  
Disk Diffusion Method ◽  
Class 1 Integron ◽  
Class 1 ◽  
Comprehensive Study

A total of 100 non-duplicate Acinetobacter baumannii isolates were collected from different hospitals in Tehran and were confirmed as A. baumannii by conventional biochemical and API testing. Antimicrobial susceptibility of these isolates was checked by a disk diffusion method in accordance with CLSI guidelines. The isolates were then detected as carrying class 1 and 2 integron gene cassettes by PCR evaluation and then genotyped by REP-PCR. More than 50% (n = 50) of the isolates were multidrug resistant. The results showed that more than 80% of all multidrug resistant A. baumannii strains carry a class 1 integron. Distribution of IntI 1 and IntI2 among A. baumannii isolates was 58% and 14%, respectively. Analysis of a conserved segment of class 1 integron showed a range from 100 bp to 2.5 kb. REP-PCR fingerprinting showed more than 20 genotypes among A. baumannii strains. TIhere was no relationship between REP genotypes and the distribution of different classes of integrons. This is a comprehensive study on the distribution of different classes of integrons among A. baumannii in Iran. Considering the exact role of integrons in coding drug resistance in bacteria, the findings of this study could help us find antimicrobial resistant mechanisms among A. baumannii isolates in Iran.

scholarly journals Phenotypic Detection of Metallo-Beta-Lactamases in Carbapenem ResistantAcinetobacter baumanniiIsolated from Pediatric Patients in Pakistan

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Muneeza Anwar ◽  
Hassan Ejaz ◽  
Aizza Zafar ◽  
Hamdan Hamid
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Disk Diffusion Method ◽  
Beta Lactamases ◽  
Kappa Value ◽  
Synergy Test ◽  
Very High ◽  
Disk Test

Multidrug resistantA. baumanniihas emerged as an important and problematic human pathogen as it is the causative agent of several types of infections especially in neonates and immunocompromised patients because they have least capacity to fight against infections. Carbapenems are used as last resort antibiotics for treating these infections but currently resistance against carbapenems due to MBL production is on the rise. The objective of this study was to determine the frequency of antibiotic resistance inA. baumanniiand also to compare the efficacy of combined disk test and double disk synergy test for detection of metallo-beta-lactamases. A total of 112A. baumanniiwere identified from various clinical samples and antibiotic susceptibility profile was determined by Kirby-Bauer Disk Diffusion method. Out of 112, 66 (58.9%) isolates were resistant to both imipenem and meropenem (OXOID). These resistant isolates were tested for carbapenemase production, and 55 (83.3%) were carbapenemase producers by Modified Hodge Test. These isolates were further tested for MBL production by combined disk test and double disk synergy test. Out of 66, 49 isolates were positive by both methods, CDT and DDST, and only one isolate was detected as negative (with kappa value = 0.038). All MBL producing strains showed remarkable resistance to cephalosporins, fluoroquinolones, aminoglycosides, and piperacillin/tazobactam (OXOID). The antibiotic resistance was very high inA. baumanniiwhich were isolated from children in Pakistan specially attending a nephrology unit.

scholarly journals Antibiogram, Prevalence of OXA Carbapenemase Encoding Genes, and RAPD-Genotyping of Multidrug-Resistant Acinetobacter baumannii Incriminated in Hidden Community-Acquired Infections

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 603
Author(s):  
Waleed El-Kazzaz ◽  
Lobna Metwally ◽  
Reham Yahia ◽  
Najwa Al-Harbi ◽  
Ayat El-Taher ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Extensively Drug Resistant ◽  
Rapd Pcr ◽  
High Prevalence ◽  
Acinetobacter Spp ◽  
Encoding Genes

Acinetobacter spp. has gained fame from their ability to resist difficult conditions and their constant development of antimicrobial resistance. This study aimed to investigate the prevalence, susceptibility testing, OXA carbapenemase-encoding genes, and RAPD-genotyping of multidrug resistant Acinetobacter baumannii incriminated in hidden community-acquired infections in Egypt. The antimicrobial susceptibility testing was assessed phenotypically using Kirby–Bauer disk diffusion method. Also, Modified-Hodge test (MHT) was carried out to detect the carbapenemases production. Multiplex-PCR was used to detect the carbapenemase-encoding genes. Furthermore, the genetic relationship among the isolated strains was investigated using RAPD fingerprinting. The bacteriological examination revealed that, out of 200 Gram-negative non-fermentative isolates, 44 (22%) were identified phenotypically and biochemically as Acinetobacter spp. and 23 (11.5%) were molecularly confirmed as A.baumannii. The retrieved A.baumannii strains were isolated from urine (69%), sputum (22%), and cerebrospinal fluid (csf) (9%). The isolated A. baumannii strains exhibited multidrug resistance and the production rates of carbapenemases were 56.5, 60.9, and 78.3% with meropenem, imipenem, and ertapenem disks, respectively. The blaOXA-24-like genes were the most predominant among the tested strains (65.2%), followed by blaOXA-23 (30.4%) and blaOXA-58 (17.4%), in addition, the examined strains are harbored IMP, VIM, and NDM genes with prevalence of 60.9, 43.5, and 13%, respectively, while KPC and GES genes were not detected. RAPD-PCR revealed that the examined strains are clustered into 11 different genotypes at ≥90% similarity. Briefly, to the best of our knowledge, this study is the first report concerning community-associated A. baumannii infections in Egypt. The high prevalence of hidden multidrug-resistant (MDR) and extensively drug-resistant (XDR) A.baumannii strains associated with non-hospitalized patients raises an alarm for healthcare authorities to set strict standards to control the spread of such pathogens with high rates of morbidity and mortality.

scholarly journals Antibiotic Resistance of Uropathogens Isolated from Patients Hospitalized in District Hospital in Central Poland in 2020

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 447
Author(s):  
Barbara Kot ◽  
Agata Grużewska ◽  
Piotr Szweda ◽  
Jolanta Wicha ◽  
Urszula Parulska
Keyword(s):  
Antibiotic Resistance ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
Beta Lactamases ◽  
E Coli ◽  
Central Poland ◽  
Resistance Patterns ◽  
Extended Spectrum Beta Lactamases ◽  
Tract Infections

The aim of this study was to determine antibiotic resistance patterns and the prevalence of uropathogenes causing urinary tract infections (UTIs) in patients hospitalized in January–June 2020 in central Poland. Antimicrobial susceptibility testing was performed using the disk-diffusion method. Escherichia coli (52.2%), Klebsiella pneumoniae (13.7%), Enterococcus faecalis (9.3%), E. faecium (6.2%), and Proteus mirabilis (4,3%) were most commonly isolated from urine samples. E. coli was significantly more frequent in women (58.6%) (p = 0.0089) and in the age group 0–18, while K. pneumoniae was more frequent in men (24.4%) (p = 0.0119) and in individuals aged 40–60 and >60. Gram-negative species showed resistance to ampicillin. K. pneumoniae were resistant to amoxicillin plus clavulanic acid (75.0%), piperacillin plus tazobactam (76.2%), cefotaxime (76.2%), cefuroxime (81.0%), ciprofloxacin (81.0%), and trimethoprim plus sulphamethoxazole (81.0%). Carbapenems were effective against all E. coli and P. mirabilis. Some K. pneumoniae (13.6%) produced metallo-β-lactamases (MBLs). E. coli (22.6%), K. pneumoniae (81.8%), and all E. faecium were multidrug-resistant (MDR). Some E. coli (26.2%), K. pneumoniae (63.6%), and P. mirabilis (14.3%) isolates produced extended-spectrum beta-lactamases (ESBL). Vancomycin-resistant E. faecium was also found. This study showed that the possibilities of UTIs therapy using available antibiotics become limited due to the increasing number of antibiotic-resistant uropathogens.

scholarly journals The activity of different extracts from Panax quinquefolium L. cultures against pathogenic Staphylococcus aureus with respect to ginsenoside content

2015 ◽  
Vol 67 (4) ◽  
pp. 1277-1284 ◽  
Author(s):  
Monika Sienkiewicz ◽  
Anna Głowacka ◽  
Edward Kowalczyk ◽  
Ewa Kochan
Keyword(s):  
Staphylococcus Aureus ◽  
Hairy Root ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Diffusion Method ◽  
Hairy Root Cultures ◽  
Root Cultures ◽  
Panax Quinquefolium ◽  
Disk Diffusion Method ◽  
Ginsenoside Content

Ginsenosides can be isolated from various cultures of Panax quinquefolium L., American ginseng. The aim of the study was to determine the antibacterial activity of extracts from leaves, stalks, hairy root cultures and field roots of P. quinquefolium L. containing ginsenosides against Staphylococcus aureus isolates obtained from various clinical materials. The agar well diffusion assay was used to evaluate microbial growth inhibition at various concentrations of extracts. The susceptibility of the clinical isolates to recommended antibiotics was determined with the disk-diffusion method. The results showed that the tested extracts inhibited the growth of all S. aureus clinical isolates, including MRSA (methicillin-resistant S. aureus) with MIC values ranging from 0.5 mg/mL to 1.7 mg/mL. The level of antimicrobial activity of extracts depends on the ginsenoside content. Both field roots and hairy root cultures represent excellent sources of these metabolites. Extracts with ginsenosides were found to inhibit multidrug-resistant staphylococci and can be a valuable complement to antistaphylococcal therapy.

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